The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.
Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.
Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
The transfer of mammalian embryos from an in vivo or in vitro environment to a suitable host to improve pregnancy or gestational outcome in human or animal. In human fertility treatment programs, preimplantation embryos ranging from the 4-cell stage to the blastocyst stage are transferred to the uterine cavity between 3-5 days after FERTILIZATION IN VITRO.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.
An assisted fertilization technique consisting of the microinjection of a single viable sperm into an extracted ovum. It is used principally to overcome low sperm count, low sperm motility, inability of sperm to penetrate the egg, or other conditions related to male infertility (INFERTILITY, MALE).
Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.
The ratio of the number of conceptions (CONCEPTION) including LIVE BIRTH; STILLBIRTH; and fetal losses, to the mean number of females of reproductive age in a population during a set time period.
The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.
The earliest developmental stage of a fertilized ovum (ZYGOTE) during which there are several mitotic divisions within the ZONA PELLUCIDA. Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally covers the period up to 16-cell MORULA.
Changes that occur to liberate the enzymes of the ACROSOME of a sperm (SPERMATOZOA). Acrosome reaction allows the sperm to penetrate the ZONA PELLUCIDA and enter the OVUM during FERTILIZATION.
Substances or mixtures that are added to the soil to supply nutrients or to make available nutrients already present in the soil, in order to increase plant growth and productivity.
The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.
Diminished or absent ability of a female to achieve conception.
Morphological and physiological development of EMBRYOS.
Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.
A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.
Techniques for the artifical induction of ovulation, the rupture of the follicle and release of the ovum.
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.
Proteins which are found in eggs (OVA) from any species.
The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.
Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.
The capacity to conceive or to induce conception. It may refer to either the male or female.
The plasma membrane of the egg.
Morphological and physiological development of EMBRYOS or FETUSES.
A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.
The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.
Results of conception and ensuing pregnancy, including LIVE BIRTH; STILLBIRTH; SPONTANEOUS ABORTION; INDUCED ABORTION. The outcome may follow natural or artificial insemination or any of the various ASSISTED REPRODUCTIVE TECHNIQUES, such as EMBRYO TRANSFER or FERTILIZATION IN VITRO.
The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).
Procedures to obtain viable OOCYTES from the host. Oocytes most often are collected by needle aspiration from OVARIAN FOLLICLES before OVULATION.
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
Artificial introduction of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.
The fluid surrounding the OVUM and GRANULOSA CELLS in the Graafian follicle (OVARIAN FOLLICLE). The follicular fluid contains sex steroids, glycoprotein hormones, plasma proteins, mucopolysaccharides, and enzymes.
Methods pertaining to the generation of new individuals, including techniques used in selective BREEDING, cloning (CLONING, ORGANISM), and assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED).
A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.
Echinoderms having bodies of usually five radially disposed arms coalescing at the center.
The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.
A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.
A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.
The element in plants that contains the female GAMETOPHYTES.
An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.
Extracts of urine from menopausal women that contain high concentrations of pituitary gonadotropins, FOLLICLE STIMULATING HORMONE and LUTEINIZING HORMONE. Menotropins are used to treat infertility. The FSH:LH ratio and degree of purity vary in different preparations.
The discharge of an OVUM from a rupturing follicle in the OVARY.
A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).
The thick, yellowish-white, viscid fluid secretion of male reproductive organs discharged upon ejaculation. In addition to reproductive organ secretions, it contains SPERMATOZOA and their nutrient plasma.
Transfer of preovulatory oocytes from donor to a suitable host. Oocytes are collected, fertilized in vitro, and transferred to a host that can be human or animal.
The granulosa cells of the cumulus oophorus which surround the OVUM in the GRAAFIAN FOLLICLE. At OVULATION they are extruded with OVUM.
A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.
Clinical and laboratory techniques used to enhance fertility in humans and animals.
The technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS.
A count of SPERM in the ejaculum, expressed as number per milliliter.
Passive or active movement of SPERMATOZOA from the testicular SEMINIFEROUS TUBULES through the male reproductive tract as well as within the female reproductive tract.
The deposit of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.
A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)
Occurrence or induction of release of more ova than are normally released at the same time in a given species. The term applies to both animals and humans.
Methods used to induce premature oocytes, that are maintained in tissue culture, to progress through developmental stages including to a stage that is competent to undergo FERTILIZATION.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
The event that a FETUS is born alive with heartbeats or RESPIRATION regardless of GESTATIONAL AGE. Such liveborn is called a newborn infant (INFANT, NEWBORN).
The total process by which organisms produce offspring. (Stedman, 25th ed)
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.
A condition of suboptimal concentration of SPERMATOZOA in the ejaculated SEMEN to ensure successful FERTILIZATION of an OVUM. In humans, oligospermia is defined as a sperm count below 20 million per milliliter semen.
A growth from a pollen grain down into the flower style which allows two sperm to pass, one to the ovum within the ovule, and the other to the central cell of the ovule to produce endosperm of SEEDS.
The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.
The condition of carrying two or more FETUSES simultaneously.
Diseases involving the FALLOPIAN TUBES including neoplasms (FALLOPIAN TUBE NEOPLASMS); SALPINGITIS; tubo-ovarian abscess; and blockage.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.
Contraceptive methods based on immunological processes and techniques, such as the use of CONTRACEPTIVE VACCINES.
A complication of OVULATION INDUCTION in infertility treatment. It is graded by the severity of symptoms which include OVARY enlargement, multiple OVARIAN FOLLICLES; OVARIAN CYSTS; ASCITES; and generalized EDEMA. The full-blown syndrome may lead to RENAL FAILURE, respiratory distress, and even DEATH. Increased capillary permeability is caused by the vasoactive substances, such as VASCULAR ENDOTHELIAL GROWTH FACTORS, secreted by the overly-stimulated OVARIES.
Undifferentiated cells resulting from cleavage of a fertilized egg (ZYGOTE). Inside the intact ZONA PELLUCIDA, each cleavage yields two blastomeres of about half size of the parent cell. Up to the 8-cell stage, all of the blastomeres are totipotent. The 16-cell MORULA contains outer cells and inner cells.
The emission of SEMEN to the exterior, resulting from the contraction of muscles surrounding the male internal urogenital ducts.
The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.
The reproductive cells of plants.
Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.
The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.
Compounds which increase the capacity to conceive in females.
Substances that provide protection against the harmful effects of freezing temperatures.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Proteins found in SEMEN. Major seminal plasma proteins are secretory proteins from the male sex accessory glands, such as the SEMINAL VESICLES and the PROSTATE. They include the seminal vesicle-specific antigen, an ejaculate clotting protein; and the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.
The fertilizing element of plants that contains the male GAMETOPHYTES.
Elements of limited time intervals, contributing to particular results or situations.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
The maturing process of SPERMATOZOA after leaving the testicular SEMINIFEROUS TUBULES. Maturation in SPERM MOTILITY and FERTILITY takes place in the EPIDIDYMIS as the sperm migrate from caput epididymis to cauda epididymis.
A species of the true toads, Bufonidae, found in South America.
The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.
Expulsion of the product of FERTILIZATION before completing the term of GESTATION and without deliberate interference.
The quality of SEMEN, an indicator of male fertility, can be determined by semen volume, pH, sperm concentration (SPERM COUNT), total sperm number, sperm viability, sperm vigor (SPERM MOTILITY), normal sperm morphology, ACROSOME integrity, and the concentration of WHITE BLOOD CELLS.
Women who allow themselves to be impregnated with the understanding that the offspring are to be given over to the parents who have commissioned the surrogate.
An early embryo that is a compact mass of about 16 BLASTOMERES. It resembles a cluster of mulberries with two types of cells, outer cells and inner cells. Morula is the stage before BLASTULA in non-mammalian animals or a BLASTOCYST in mammals.
Hormones that stimulate gonadal functions such as GAMETOGENESIS and sex steroid hormone production in the OVARY and the TESTIS. Major gonadotropins are glycoproteins produced primarily by the adenohypophysis (GONADOTROPINS, PITUITARY) and the placenta (CHORIONIC GONADOTROPIN). In some species, pituitary PROLACTIN and PLACENTAL LACTOGEN exert some luteotropic activities.
Procedures to obtain viable sperm from the male reproductive tract, including the TESTES, the EPIDIDYMIS, or the VAS DEFERENS.
The removal of secretions, gas or fluid from hollow or tubular organs or cavities by means of a tube and a device that acts on negative pressure.
Sexual activities of animals.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
A potent synthetic analog of GONADOTROPIN-RELEASING HORMONE with D-serine substitution at residue 6, glycine10 deletion, and other modifications.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
The potential of the FETUS to survive outside the UTERUS after birth, natural or induced. Fetal viability depends largely on the FETAL ORGAN MATURITY, and environmental conditions.
The transformation of a liquid to a glassy solid i.e., without the formation of crystals during the cooling process.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Chemical agents that increase the permeability of biological or artificial lipid membranes to specific ions. Most ionophores are relatively small organic molecules that act as mobile carriers within membranes or coalesce to form ion permeable channels across membranes. Many are antibiotics, and many act as uncoupling agents by short-circuiting the proton gradient across mitochondrial membranes.
A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.
The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.
A group of simple proteins that yield basic amino acids on hydrolysis and that occur combined with nucleic acid in the sperm of fish. Protamines contain very few kinds of amino acids. Protamine sulfate combines with heparin to form a stable inactive complex; it is used to neutralize the anticoagulant action of heparin in the treatment of heparin overdose. (From Merck Index, 11th ed; Martindale, The Extra Pharmacopoeia, 30th ed, p692)
Ducts that serve exclusively for the passage of eggs from the ovaries to the exterior of the body. In non-mammals, they are termed oviducts. In mammals, they are highly specialized and known as FALLOPIAN TUBES.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.
The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
A technique that came into use in the mid-1980's for assisted conception in infertile women with normal fallopian tubes. The protocol consists of hormonal stimulation of the ovaries, followed by laparoscopic follicular aspiration of oocytes, and then the transfer of sperm and oocytes by catheterization into the fallopian tubes.
A genus of SEA URCHINS in the family Toxopneustidae possessing trigeminate ambulacral plating.
The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).
A potent synthetic agonist of GONADOTROPIN-RELEASING HORMONE with 3-(2-naphthyl)-D-alanine substitution at residue 6. Nafarelin has been used in the treatments of central PRECOCIOUS PUBERTY and ENDOMETRIOSIS.
The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.
An enzyme that catalyzes the random hydrolysis of 1,4-linkages between N-acetyl-beta-D-glucosamine and D-glucuronate residues in hyaluronate. (From Enzyme Nomenclature, 1992) There has been use as ANTINEOPLASTIC AGENTS to limit NEOPLASM METASTASIS.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.
The age of the mother in PREGNANCY.
Determination of the nature of a pathological condition or disease in the OVUM; ZYGOTE; or BLASTOCYST prior to implantation. CYTOGENETIC ANALYSIS is performed to determine the presence or absence of genetic disease.
A phylum of metazoan invertebrates comprising the segmented worms, and including marine annelids (POLYCHAETA), freshwater annelids, earthworms (OLIGOCHAETA), and LEECHES. Only the leeches are of medical interest. (Dorland, 27th ed)
Inbred ICR mice are a strain of albino laboratory mice that have been selectively bred for consistent genetic makeup and high reproductive performance, making them widely used in biomedical research for studies involving reproduction, toxicology, pharmacology, and carcinogenesis.
Gonadotropins secreted by the pituitary or the placenta in horses. This term generally refers to the gonadotropins found in the pregnant mare serum, a rich source of equine CHORIONIC GONADOTROPIN; LUTEINIZING HORMONE; and FOLLICLE STIMULATING HORMONE. Unlike that in humans, the equine LUTEINIZING HORMONE, BETA SUBUNIT is identical to the equine choronic gonadotropin, beta. Equine gonadotropins prepared from pregnant mare serum are used in reproductive studies.
Glycosidic antibiotic from Streptomyces griseus used as a fluorescent stain of DNA and as an antineoplastic agent.
Nutritive tissue of the seeds of flowering plants that surrounds the EMBRYOS. It is produced by a parallel process of fertilization in which a second male gamete from the pollen grain fuses with two female nuclei within the embryo sac. The endosperm varies in ploidy and contains reserves of starch, oils, and proteins, making it an important source of human nutrition.
A division of predominantly marine EUKARYOTA, commonly known as brown algae, having CHROMATOPHORES containing carotenoid PIGMENTS, BIOLOGICAL. ALGINATES and phlorotannins occur widely in all major orders. They are considered the most highly evolved algae because of their well-developed multicellular organization and structural complexity.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
The fundamental dispositions and traits of humans. (Merriam-Webster's Collegiate Dictionary, 10th ed)
The reproductive organs of plants.
A condition of having no sperm present in the ejaculate (SEMEN).
Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.
The point at which religious ensoulment or PERSONHOOD is considered to begin.
A major gonadotropin secreted by the human adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and the LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. The alpha subunit is common in the three human pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
The state that distinguishes organisms from inorganic matter, manifested by growth, metabolism, reproduction, and adaptation. It includes the course of existence, the sum of experiences, the mode of existing, or the fact of being. Over the centuries inquiries into the nature of life have crossed the boundaries from philosophy to biology, forensic medicine, anthropology, etc., in creative as well as scientific literature. (Random House Unabridged Dictionary, 2d ed; Dr. James H. Cassedy, NLM History of Medicine Division)
Two individuals derived from two FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother. Twins are either monozygotic (TWINS, MONOZYGOTIC) or dizygotic (TWINS, DIZYGOTIC).
A technique in assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED) consisting of hormonal stimulation of the ovaries, follicular aspiration of preovulatory oocytes, in-vitro fertilization, and intrafallopian transfer of zygotes at the pronuclear stage (before cleavage).
Methods for controlling genetic SEX of offspring.
The transfer of POLLEN grains (male gametes) to the plant ovule (female gamete).
Glycoproteins found on the membrane or surface of cells.
A potentially life-threatening condition in which EMBRYO IMPLANTATION occurs outside the cavity of the UTERUS. Most ectopic pregnancies (>96%) occur in the FALLOPIAN TUBES, known as TUBAL PREGNANCY. They can be in other locations, such as UTERINE CERVIX; OVARY; and abdominal cavity (PREGNANCY, ABDOMINAL).
A potent synthetic long-acting agonist of GONADOTROPIN-RELEASING HORMONE that regulates the synthesis and release of pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE.
The period of the MENSTRUAL CYCLE representing follicular growth, increase in ovarian estrogen (ESTROGENS) production, and epithelial proliferation of the ENDOMETRIUM. Follicular phase begins with the onset of MENSTRUATION and ends with OVULATION.
Cellular proteins encoded by the c-mos genes (GENES, MOS). They function in the cell cycle to maintain MATURATION PROMOTING FACTOR in the active state and have protein-serine/threonine kinase activity. Oncogenic transformation can take place when c-mos proteins are expressed at the wrong time.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Sexual union of a male and a female in non-human species.
Embryonic and fetal development that takes place in an artificial environment in vitro.
Agglutination of spermatozoa by antibodies or autoantibodies.
Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
Human artificial insemination in which the husband's semen is used.
The number of births in a given population per year or other unit of time.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Minute cells produced during development of an OOCYTE as it undergoes MEIOSIS. A polar body contains one of the nuclei derived from the first or second meiotic CELL DIVISION. Polar bodies have practically no CYTOPLASM. They are eventually discarded by the oocyte. (from King & Stansfield, A Dictionary of Genetics, 4th ed)
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
A class in the phylum MOLLUSCA comprised of SNAILS and slugs. The former have coiled external shells and the latter usually lack shells.
Liquids transforming into solids by the removal of heat.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Inbred CBA mice are a strain of laboratory mice that have been selectively bred to be genetically identical and uniform, which makes them useful for scientific research, particularly in the areas of immunology and cancer.
Human artificial insemination in which the semen used is that of a man other than the woman's husband.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.
Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4,5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1,4,5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell's endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin.
A type C phospholipase with specificity towards PHOSPHATIDYLINOSITOLS that contain INOSITOL 1,4,5-TRISPHOSPHATE. Many of the enzymes listed under this classification are involved in intracellular signaling.
A condition in which functional endometrial tissue is present outside the UTERUS. It is often confined to the PELVIS involving the OVARY, the ligaments, cul-de-sac, and the uterovesical peritoneum.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.
Three individuals derived from three FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother.
Chemical agents that increase the permeability of CELL MEMBRANES to CALCIUM ions.
The period in the MENSTRUAL CYCLE that follows OVULATION, characterized by the development of CORPUS LUTEUM, increase in PROGESTERONE production by the OVARY and secretion by the glandular epithelium of the ENDOMETRIUM. The luteal phase begins with ovulation and ends with the onset of MENSTRUATION.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).
A potent synthetic long-acting agonist of GONADOTROPIN-RELEASING HORMONE with D-tryptophan substitution at residue 6.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
The techniques used to select and/or place only one embryo from FERTILIZATION IN VITRO into the uterine cavity to establish a singleton pregnancy.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.
Experimentation on, or using the organs or tissues from, a human or other mammalian conceptus during the prenatal stage of development that is characterized by rapid morphological changes and the differentiation of basic structures. In humans, this includes the period from the time of fertilization to the end of the eighth week after fertilization.
The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.
A plant genus of the family POACEAE that is used for forage.
A class in the phylum MOLLUSCA comprised of mussels; clams; OYSTERS; COCKLES; and SCALLOPS. They are characterized by a bilaterally symmetrical hinged shell and a muscular foot used for burrowing and anchoring.
An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.
The state or condition of being a human individual accorded moral and/or legal rights. Criteria to be used to determine this status are subject to debate, and range from the requirement of simply being a human organism to such requirements as that the individual be self-aware and capable of rational thought and moral agency.
An ethylmercury-sulfidobenzoate that has been used as a preservative in VACCINES; ANTIVENINS; and OINTMENTS. It was formerly used as a topical antiseptic. It degrades to ethylmercury and thiosalicylate.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
Liquid components of living organisms.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
The hollow thick-walled muscular organ in the female PELVIS. It consists of the fundus (the body) which is the site of EMBRYO IMPLANTATION and FETAL DEVELOPMENT. Beyond the isthmus at the perineal end of fundus, is CERVIX UTERI (the neck) opening into VAGINA. Beyond the isthmi at the upper abdominal end of fundus, are the FALLOPIAN TUBES.

Ontogeny of expression of a receptor for platelet-activating factor in mouse preimplantation embryos and the effects of fertilization and culture in vitro on its expression. (1/4970)

Platelet-activating factor (PAF; 1-o-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a potent ether phospholipid. It is one of the preimplantation embryo's autocrine growth/survival factors. It may act via a G protein-linked receptor on the embryo; however, the evidence for this is conflicting. The recent description of the intracellular form of the PAF:acetlyhydrolase enzyme as having structural homology with G proteins and Ras also suggests this as a potential intracellular receptor/transducer for PAF. This study used reverse transcription-polymerase chain reaction to examine the ontogeny of expression of the genes for these proteins in the oocyte and preimplantation-stage embryo. Transcripts for the G protein-linked PAF receptor were detected in the late 2-cell-stage embryo and in all stages from the 4-cell stage to blastocysts. They were also present in unfertilized oocytes and newly fertilized zygotes but only at relatively low levels. The incidence of expression was generally low and variable in late zygotes and early 2-cell embryos. Expression past the 2-cell stage was alpha-amanitin sensitive. The results indicated that mRNA for this receptor is a maternal transcript that was degraded during the zygote-2-cell stage. New expression of the receptor transcript required activation of the zygotic genome. Fertilization of embryos in vitro caused this transcript not to be expressed in the zygote. Culture of zygotes (irrespective of their method of fertilization) caused expression from the zygotic genome to be retarded by more than 24 h. This retardation did not occur if culture commenced at the 2-cell stage. The transcripts for the subunits of intracellular PAF:acetylhydrolase were not detected in oocytes or at any stage of embryo development examined, despite their being readily detected in control tissue. This study confirms the presence of the G protein-linked PAF receptor in the 2-cell embryo and describes for the first time its normal pattern of expression during early development. The adverse effects of in vitro fertilization (IVF) and embryo culture on the expression of this transcript may be a contributing factor for the poor viability of embryos produced in this manner. The reduced expression of PAF-receptor mRNA following IVF predicts that such embryos may have a deficiency in autocrine stimulation and also suggests that supplementation of growth media with exogenous PAF would be only partially beneficial. The effect of IVF and culture may also explain the conflicting literature.  (+info)

An intact sperm nuclear matrix may be necessary for the mouse paternal genome to participate in embryonic development. (2/4970)

We have been interested in determining the minimally required elements in the sperm head that are necessary in order for the paternal genome to participate in embryogenesis. We used an ionic detergent, mixed alkyltrimethylammonium bromide (ATAB), plus dithiothreitol (DTT) to remove the acrosome and almost all of the perinuclear theca, leaving only the sperm nucleus morphologically intact. We also tested the stability of the sperm nuclear matrix by the ability to form nuclear halos. Sperm nuclei washed in freshly prepared 0.5% ATAB + 2 mM DTT completely decondensed when extracted with salt, but nuclei washed in the same buffer that was 1 wk old, and then extracted with salt, produced nuclear halos, indicating stable nuclear matrices. When we treated sperm heads with freshly prepared ATAB+DTT and injected them into oocytes, none of the oocytes developed into live offspring. In contrast, sperm heads treated in the same way but with 1-wk-old ATAB+DTT solution could support development of about 30% of the oocytes to live offspring. Electron microscopy demonstrated that most of the perinuclear theca had been removed in both cases. These data suggest that at least in the mouse, the only component of the spermatozoa that is crucial for participation in embryologic development is the sperm nucleus with a stable nuclear matrix.  (+info)

Endometrial oestrogen and progesterone receptors and their relationship to sonographic appearance of the endometrium. (3/4970)

The rapid development of ultrasonographic equipment now permits instantaneous assessment of follicles and endometrium. The sonographic appearance of the endometrium has been discussed in relation to in-vitro fertilization (IVF) cycles. However, a generally agreed view of the relationship of the sonographic appearance to fecundity in IVF cycles has not emerged. We have studied the relationship between steroid receptors and the sonographic appearance of the preovulatory endometrium in natural cycles and ovulation induction cycles. Preovulatory endometrial thickness was not found to be indicative of fecundity, although a preovulatory endometrial thickness of <9 mm related to an elevated miscarriage rate. The preovulatory endometrial echo pattern did not predict fecundity. No relationships were found among endometrial appearance, endometrial steroid receptors and steroid hormone concentrations in serum. Oestrogen or progesterone receptor concentrations were not related to endometrial thickness or to concentrations of serum oestradiol, the only significant correlation being found between the endometrial concentrations of oestrogen and progesterone receptors. The ratio of progesterone:oestrogen receptor concentration was somewhat less in echo pattern B (not triple line) endometrium compared with pattern A (triple line) endometrium. Oestrogen and progesterone receptor concentrations appeared stable on gonadotrophin induction, though fewer numbers were found during clomiphene cycles than in natural cycles. With regard to the distribution of receptor concentration between clomiphene and natural cycles, most women using clomiphene had very low oestrogen receptor populations. Pregnancy rates were low, in spite of high ovulatory rates during clomiphene treatment and were mainly related to low oestrogen receptor concentrations in preovulatory endometrium.  (+info)

Expression of CD44 in human cumulus and mural granulosa cells of individual patients in in-vitro fertilization programmes. (4/4970)

CD44 is a polymorphic and polyfunctional transmembrane glycoprotein widely expressed in many types of cells. Here, the expression of this protein on human membrana granulosa was studied by two techniques. Using confocal laser scanning microscopy (CLSM) with the mouse monoclonal antibody to human CD44 (clone G44-26), cells immunoreactive for CD44 were observed in both cumulus and mural granulosa cell masses. On the other hand, using monoclonal antibody to human CD44v9, goat polyclonal antibody to human CD44v3-10 and the clone G44-26, no immunoreactivity for CD44v9 and/or CD44v3-10 was observed in either cell group by flow cytometry. In the flow cytometric analysis of 32 patients, the incidence of CD44 expression in cumulus cells (62.6+/-1.3%) was significantly higher than that in mural granulosa cells (38.5+/-3.2%) (P<0.0001). In the comparison of CD44 expression by flow cytometry according to the maturation of each cumulus-oocyte complex, the incidence of CD44 expression of cumulus cells was significantly higher in the mature group than in the immature group (P<0.05). In a flow cytometric analysis, patients with endometriosis showed a significantly lower incidence of CD44 expression in cumulus cells compared to the infertility of unknown origin group (P<0.05), and compared to both the male infertility group and the unknown origin group in mural granulosa cells (P<0.01). These findings suggest that the standard form of CD44 is expressed in human membrana granulosa with polarity and may play an important role in oocyte maturation.  (+info)

Origin of DNA damage in ejaculated human spermatozoa. (5/4970)

The molecular basis of many forms of male infertility is poorly defined. One area of research that has been studied intensely is the integrity of the DNA in the nucleus of mature ejaculated spermatozoa. It has been shown that, in men with abnormal sperm parameters, the DNA is more likely to possess strand breaks. However, how and why this DNA damage originates in certain males and how it may influence the genetic project of a mature spermatozoon is unknown. Two theories have been proposed to describe the origin of this DNA damage in mature spermatozoa. The first arises from studies performed in animal models and is linked to the unique manner in which mammalian sperm chromatin is packaged, while the second attributes the nuclear DNA damage in mature spermatozoa to apoptosis. One of the factors implicated in sperm apoptosis is the cell surface protein, Fas. In this review, we discuss the possible origins of DNA damage in ejaculated human spermatozoa, how these spermatozoa arrive in the ejaculate of some men, and what consequences they may have if they succeed in their genetic project.  (+info)

In-vitro fertilization and culture of mouse embryos in vitro significantly retards the onset of insulin-like growth factor-II expression from the zygotic genome. (6/4970)

In this study, the effect of in-vitro fertilization (IVF) and culture of mouse embryos in vitro on the normal expression of insulin-like growth factor-II (IFG-II) ligand and receptor was examined. The expression of IGF-II increased in a linear fashion at least up to the 8-cell stage of development. IGF-II expression in embryos collected fresh from the reproductive tract was significantly (P < 0.001) greater than in embryos fertilized in the reproductive tract and cultured in vitro (in-situ fertilized: ISF), and its expression was further reduced (P < 0.001) in IVF embryos at all development stages tested. The expression of IGF-II was significantly (P < 0.001) lower when embryos were cultured individually in 100 microl drops compared with culture in groups of 10 in 10 microl drops of medium. The addition of platelet activating factor to culture medium partially overcame this density-dependent decline of expression. Culture of ISF and IVF zygotes also caused the onset of new IGF-II mRNA transcription from the zygotic genome to be significantly (P < 0.001) retarded, until at least the 8-cell stage of development. This effect was greater (P < 0.05) for IVF than for ISF embryos. Neither IVF nor culture had any obvious effect on IFG-II/mannose-6-phosphate receptor (IGF-IIr) mRNA expression.  (+info)

Detection of benzo[a]pyrene diol epoxide-DNA adducts in embryos from smoking couples: evidence for transmission by spermatozoa. (7/4970)

Tobacco smoking is deleterious to reproduction. Benzo[a]pyrene (B[a]P) is a potent carcinogen in cigarette smoke. Its reactive metabolite induces DNA-adducts, which can cause mutations. We investigated whether B[a]P diol epoxide (BPDE) DNA adducts are detectable in preimplantation embryos in relation to parental smoking. A total of 17 couples were classified by their smoking habits: (i) both partners smoke; (ii) wife non-smoker, husband smokes; and (iii) both partners were non-smokers. Their 27 embryos were exposed to an anti-BPDE monoclonal antibody that recognizes BPDE-DNA adducts. Immunostaining was assessed in each embryo and an intensity score was calculated for embryos in each smoking group. The proportion of blastomeres which stained was higher for embryos of smokers than for non-smokers (0.723 versus 0.310). The mean intensity score was also higher for embryos of smokers (1.40+/-0.28) than for non-smokers (0.38+/-0.14; P = 0.015), but was similar for both types of smoking couples. The mean intensity score was positively correlated with the number of cigarettes smoked by fathers (P = 0.02). Increased mean immunostaining in embryos from smokers, relative to non-smokers, indicates a relationship with parental smoking. The similar levels of immunostaining in embryos from both types of smoking couples suggest that transmission of modified DNA is mainly through spermatozoa. We confirmed paternal transmission of modified DNA by detection of DNA adducts in spermatozoa of a smoker father and his embryo.  (+info)

Fertilization, embryonic development, and offspring from mouse eggs injected with round spermatids combined with Ca2+ oscillation-inducing sperm factor. (8/4970)

Round spermatids, precursor male gametes, are known to possess the potential to achieve fertilization and embryonic development when injected into eggs. However, injection of spermatids alone seldom activates eggs in the mouse, as spermatids by themselves cannot induce an increase in intracellular Ca2+, a prerequisite for egg activation. We injected a mouse round spermatid into an egg simultaneously with partially purified sperm factor from differentiated hamster spermatozoa. The combined injection produced repetitive Ca2+ increases (Ca2+ oscillations) lasting for at least 4 h as observed at fertilization, and induced activation in 92% of eggs. This method provided 75% fertilization success associated with male and female pronucleus formation and development to 2-cell embryos, while only 7% of eggs were fertilized by injection of a spermatid alone. Of the 2-cell embryos, approximately 50% developed to blastocysts during 5 days of culture in vitro, while no blastocysts were obtained following injection of sperm factor alone. Furthermore, the 2-cell embryos, that were created by spermatids and sperm factor and transplanted into foster mothers, developed into normal offspring, although the percentage was only 22%. All infants grew into healthy adults carrying normal chromosomes. The sperm factor served as a complementary factor for successful fertilization by round spermatid injection.  (+info)

Fertilization is the process by which a sperm cell (spermatozoon) penetrates and fuses with an egg cell (ovum), resulting in the formation of a zygote. This fusion of genetic material from both the male and female gametes initiates the development of a new organism. In human biology, fertilization typically occurs in the fallopian tube after sexual intercourse, when a single sperm out of millions is able to reach and penetrate the egg released from the ovary during ovulation. The successful fusion of these two gametes marks the beginning of pregnancy.

Fertilization in vitro, also known as in-vitro fertilization (IVF), is a medical procedure where an egg (oocyte) and sperm are combined in a laboratory dish to facilitate fertilization. The fertilized egg (embryo) is then transferred to a uterus with the hope of establishing a successful pregnancy. This procedure is often used when other assisted reproductive technologies have been unsuccessful or are not applicable, such as in cases of blocked fallopian tubes, severe male factor infertility, and unexplained infertility. The process involves ovarian stimulation, egg retrieval, fertilization, embryo culture, and embryo transfer. In some cases, additional techniques such as intracytoplasmic sperm injection (ICSI) or preimplantation genetic testing (PGT) may be used to increase the chances of success.

Spermatozoa are the male reproductive cells, or gametes, that are produced in the testes. They are microscopic, flagellated (tail-equipped) cells that are highly specialized for fertilization. A spermatozoon consists of a head, neck, and tail. The head contains the genetic material within the nucleus, covered by a cap-like structure called the acrosome which contains enzymes to help the sperm penetrate the female's egg (ovum). The long, thin tail propels the sperm forward through fluid, such as semen, enabling its journey towards the egg for fertilization.

Sperm-ovum interactions, also known as sperm-egg interactions, refer to the specific series of events that occur between a spermatozoon (sperm) and an oocyte (egg or ovum) during fertilization in sexual reproduction.

The process begins with the sperm's attachment to the zona pellucida, a glycoprotein layer surrounding the oocyte. This interaction is mediated by specific proteins on the surface of both the sperm and the zona pellucida. Following attachment, the sperm undergoes the acrosome reaction, during which enzymes are released from the sperm's head to help digest and penetrate the zona pellucida.

Once the sperm has successfully traversed the zona pellucida, it makes contact with the oocyte's plasma membrane, triggering the fusion of the sperm and egg membranes. This results in the release of the sperm's genetic material into the oocyte's cytoplasm and the initiation of a series of intracellular signaling events within the oocyte that ultimately lead to its completion of meiosis II and formation of a zygote, marking the beginning of embryonic development.

Proper sperm-ovum interactions are crucial for successful fertilization and subsequent embryonic development, and any disruptions in these processes can result in infertility or early pregnancy loss.

An ovum is the female reproductive cell, or gamete, produced in the ovaries. It is also known as an egg cell and is released from the ovary during ovulation. When fertilized by a sperm, it becomes a zygote, which can develop into a fetus. The ovum contains half the genetic material necessary to create a new individual.

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

Embryo transfer is a medical procedure that involves the transfer of an embryo, which is typically created through in vitro fertilization (IVF), into the uterus of a woman with the aim of establishing a pregnancy. The embryo may be created using the intended parent's own sperm and eggs or those from donors. After fertilization and early cell division, the resulting embryo is transferred into the uterus of the recipient mother through a thin catheter that is inserted through the cervix. This procedure is typically performed under ultrasound guidance to ensure proper placement of the embryo. Embryo transfer is a key step in assisted reproductive technology (ART) and is often used as a treatment for infertility.

A zygote is the initial cell formed when a sperm fertilizes an egg, also known as an oocyte. This occurs in the process of human reproduction and marks the beginning of a new genetic identity, containing 46 chromosomes - 23 from the sperm and 23 from the egg. The zygote starts the journey of cell division and growth, eventually developing into a blastocyst, then an embryo, and finally a fetus over the course of pregnancy.

Zona pellucida is a term used in the field of reproductive biology and it refers to the glycoprotein membrane that surrounds mammalian oocytes (immature egg cells). This membrane plays a crucial role in the fertilization process. It has receptors for sperm, and upon binding with the sperm, it undergoes changes that prevent other sperm from entering, a process known as the zona reaction. This membrane is also involved in the early development of the embryo.

Intracytoplasmic Sperm Injection (ICSI) is a specialized form of assisted reproductive technology (ART), specifically used in the context of in vitro fertilization (IVF). It involves the direct injection of a single sperm into the cytoplasm of a mature egg (oocyte) to facilitate fertilization. This technique is often used when there are issues with male infertility, such as low sperm count or poor sperm motility, to increase the chances of successful fertilization. The resulting embryos can then be transferred to the uterus in hopes of achieving a pregnancy.

Sperm motility is the ability of sperm to move actively and effectively through the female reproductive tract towards the egg for fertilization. It is typically measured as the percentage of moving sperm in a sample, and their progressiveness or velocity. Normal human sperm motility is generally defined as forward progression of at least 25 micrometers per second, with at least 50% of sperm showing progressive motility. Reduced sperm motility, also known as asthenozoospermia, can negatively impact fertility and reproductive outcomes.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

I'm happy to help! However, it seems there might be a bit of confusion here. "Sea urchins" is a common name that refers to a type of marine invertebrate animal, typically characterized by their round, spiny shells. They belong to the class Echinoidea within the phylum Echinodermata.

Medically speaking, there isn't a specific definition for "sea urchins." However, if you come into contact with sea urchins while swimming or diving and accidentally step on them, their spines can puncture your skin and potentially cause an infection. In this case, medical attention may be necessary to remove the embedded spines and treat any resulting infection.

If you were referring to a specific medical term related to sea urchins, could you please clarify? I'm here to help!

The pregnancy rate is a measure used in reproductive medicine to determine the frequency or efficiency of conception following certain treatments, interventions, or under specific conditions. It is typically defined as the number of pregnancies per 100 women exposed to the condition being studied over a specified period of time. A pregnancy is confirmed when a woman has a positive result on a pregnancy test or through the detection of a gestational sac on an ultrasound exam.

In clinical trials and research, the pregnancy rate helps healthcare professionals evaluate the effectiveness of various fertility treatments such as in vitro fertilization (IVF), intrauterine insemination (IUI), or ovulation induction medications. The pregnancy rate can also be used to assess the impact of lifestyle factors, environmental exposures, or medical conditions on fertility and conception.

It is important to note that pregnancy rates may vary depending on several factors, including age, the cause of infertility, the type and quality of treatment provided, and individual patient characteristics. Therefore, comparing pregnancy rates between different studies should be done cautiously, considering these potential confounding variables.

The acrosome is a specialized structure located on the anterior part of the sperm head in many species of animals, including humans. It contains enzymes that help the sperm penetrate the outer covering of the egg (zona pellucida) during fertilization. The acrosome reaction is the process by which the acrosome releases its enzymes, allowing the sperm to digest a path through the zona pellucida and reach the egg plasma membrane for fusion and fertilization.

The acrosome is formed during spermatogenesis, the process of sperm production in the testis, from the Golgi apparatus, a cellular organelle involved in protein trafficking and modification. The acrosome contains hydrolytic enzymes such as hyaluronidase, acrosin, and proteases that are activated during the acrosome reaction to facilitate sperm-egg fusion.

Abnormalities in acrosome formation or function can lead to infertility in males.

The cleavage stage of an ovum, also known as a fertilized egg, refers to the series of rapid cell divisions that occur after fertilization. During this stage, the single cell (zygote) divides into multiple cells, forming a blastomere. This process occurs in the fallopian tube and continues until the blastocyst reaches the uterus, typically around 5-6 days after fertilization. The cleavage stage is a critical period in early embryonic development, as any abnormalities during this time can lead to implantation failure or developmental defects.

The acrosome reaction is a crucial event in the fertilization process of many species, including humans. It occurs when the sperm makes contact with and binds to the zona pellucida, the glycoprotein-rich extracellular matrix that surrounds the egg. This interaction triggers a series of molecular events leading to the exocytosis of the acrosome, a membrane-bound organelle located at the tip of the sperm head.

The acrosome contains hydrolytic enzymes that help the sperm to penetrate the zona pellucida and reach the egg's plasma membrane. During the acrosome reaction, the outer acrosomal membrane fuses with the sperm plasma membrane, releasing these enzymes and causing the release of the inner acrosomal membrane, which then reorganizes to form a structure called the acrosomal cap.

The acrosome reaction exposes new proteins on the sperm surface that can interact with the egg's plasma membrane, allowing for the fusion of the two membranes and the entry of the sperm into the egg. This event is essential for successful fertilization and subsequent embryonic development.

Fertilizers are substances that are added to soil to provide nutrients necessary for plant growth and development. They typically contain macronutrients such as nitrogen (N), phosphorus (P), and potassium (K) in forms that can be readily taken up by plants. These three nutrients are essential for photosynthesis, energy transfer, and the production of proteins, nucleic acids, and other vital plant compounds.

Fertilizers may also contain secondary nutrients like calcium (Ca), magnesium (Mg), and sulfur (S) as well as micronutrients such as iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), and molybdenum (Mo). These elements play crucial roles in various plant metabolic processes, including enzyme activation, chlorophyll synthesis, and hormone production.

Fertilizers can be organic or synthetic. Organic fertilizers include materials like compost, manure, bone meal, and blood meal, which release nutrients slowly over time as they decompose. Synthetic fertilizers, also known as inorganic or chemical fertilizers, are manufactured chemicals that contain precise amounts of specific nutrients. They can be quickly absorbed by plants but may pose environmental risks if not used properly.

Proper fertilization is essential for optimal plant growth and crop yield. However, overuse or improper application of fertilizers can lead to nutrient runoff, soil degradation, water pollution, and other negative environmental impacts. Therefore, it's crucial to follow recommended fertilizer application rates and practices based on the specific needs of the plants and local regulations.

Sperm capacitation is a complex process that occurs in the female reproductive tract and prepares sperm for fertilization. It involves a series of biochemical modifications to the sperm's membrane and motility, which enable it to undergo the acrosome reaction and penetrate the zona pellucida surrounding the egg.

The capacitation process typically takes several hours and requires the sperm to be exposed to specific factors in the female reproductive tract, including bicarbonate ions, calcium ions, and certain proteins. During capacitation, cholesterol is removed from the sperm's plasma membrane, which leads to an increase in membrane fluidity and the exposure of receptors that are necessary for binding to the egg.

Capacitation is a critical step in the fertilization process, as it ensures that only sperm that have undergone this process can successfully fertilize the egg. Abnormalities in sperm capacitation have been linked to infertility and other reproductive disorders.

Female infertility is a condition characterized by the inability to conceive after 12 months or more of regular, unprotected sexual intercourse or the inability to carry a pregnancy to a live birth. The causes of female infertility can be multifactorial and may include issues with ovulation, damage to the fallopian tubes or uterus, endometriosis, hormonal imbalances, age-related factors, and other medical conditions.

Some common causes of female infertility include:

1. Ovulation disorders: Conditions such as polycystic ovary syndrome (PCOS), thyroid disorders, premature ovarian failure, and hyperprolactinemia can affect ovulation and lead to infertility.
2. Damage to the fallopian tubes: Pelvic inflammatory disease, endometriosis, or previous surgeries can cause scarring and blockages in the fallopian tubes, preventing the egg and sperm from meeting.
3. Uterine abnormalities: Structural issues with the uterus, such as fibroids, polyps, or congenital defects, can interfere with implantation and pregnancy.
4. Age-related factors: As women age, their fertility declines due to a decrease in the number and quality of eggs.
5. Other medical conditions: Certain medical conditions, such as diabetes, celiac disease, and autoimmune disorders, can contribute to infertility.

In some cases, female infertility can be treated with medications, surgery, or assisted reproductive technologies (ART) like in vitro fertilization (IVF). A thorough evaluation by a healthcare professional is necessary to determine the underlying cause and develop an appropriate treatment plan.

Embryonic development is the series of growth and developmental stages that occur during the formation and early growth of the embryo. In humans, this stage begins at fertilization (when the sperm and egg cell combine) and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (now called a zygote) divides and forms a blastocyst, which then implants into the uterus. The cells in the blastocyst begin to differentiate and form the three germ layers: the ectoderm, mesoderm, and endoderm. These germ layers will eventually give rise to all of the different tissues and organs in the body.

Embryonic development is a complex and highly regulated process that involves the coordinated interaction of genetic and environmental factors. It is characterized by rapid cell division, migration, and differentiation, as well as programmed cell death (apoptosis) and tissue remodeling. Abnormalities in embryonic development can lead to birth defects or other developmental disorders.

It's important to note that the term "embryo" is used to describe the developing organism from fertilization until the end of the 8th week of pregnancy in humans, after which it is called a fetus.

Cryopreservation is a medical procedure that involves the preservation of cells, tissues, or organs by cooling them to very low temperatures, typically below -150°C. This is usually achieved using liquid nitrogen. The low temperature slows down or stops biological activity, including chemical reactions and cellular metabolism, which helps to prevent damage and decay.

The cells, tissues, or organs that are being cryopreserved must be treated with a cryoprotectant solution before cooling to prevent the formation of ice crystals, which can cause significant damage. Once cooled, the samples are stored in specialized containers or tanks until they are needed for use.

Cryopreservation is commonly used in assisted reproductive technologies, such as the preservation of sperm, eggs, and embryos for fertility treatments. It is also used in research, including the storage of cell lines and stem cells, and in clinical settings, such as the preservation of skin grafts and corneas for transplantation.

A blastocyst is a stage in the early development of a fertilized egg, or embryo, in mammals. It occurs about 5-6 days after fertilization and consists of an outer layer of cells called trophoblasts, which will eventually form the placenta, and an inner cell mass, which will give rise to the fetus. The blastocyst is characterized by a fluid-filled cavity called the blastocoel. This stage is critical for the implantation of the embryo into the uterine lining.

Ovulation induction is a medical procedure that involves the stimulation of ovulation (the release of an egg from the ovaries) in women who have difficulties conceiving due to ovulatory disorders. This is typically achieved through the use of medications such as clomiphene citrate or gonadotropins, which promote the development and maturation of follicles in the ovaries containing eggs. The process is closely monitored through regular ultrasounds and hormone tests to ensure appropriate response and minimize the risk of complications like multiple pregnancies. Ovulation induction may be used as a standalone treatment or in conjunction with other assisted reproductive technologies (ART), such as intrauterine insemination (IUI) or in vitro fertilization (IVF).

Male infertility is a condition characterized by the inability to cause pregnancy in a fertile female. It is typically defined as the failure to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse.

The causes of male infertility can be varied and include issues with sperm production, such as low sperm count or poor sperm quality, problems with sperm delivery, such as obstructions in the reproductive tract, or hormonal imbalances that affect sperm production. Other factors that may contribute to male infertility include genetic disorders, environmental exposures, lifestyle choices, and certain medical conditions or treatments.

It is important to note that male infertility can often be treated or managed with medical interventions, such as medication, surgery, or assisted reproductive technologies (ART). A healthcare provider can help diagnose the underlying cause of male infertility and recommend appropriate treatment options.

Infertility is a reproductive health disorder defined as the failure to achieve a clinical pregnancy after 12 months or more of regular, unprotected sexual intercourse or due to an impairment of a person's capacity to reproduce either as an individual or with their partner. It can be caused by various factors in both men and women, including hormonal imbalances, structural abnormalities, genetic issues, infections, age, lifestyle factors, and others. Infertility can have significant emotional and psychological impacts on individuals and couples experiencing it, and medical intervention may be necessary to help them conceive.

Egg proteins, also known as egg white proteins or ovalbumin, refer to the proteins found in egg whites. There are several different types of proteins found in egg whites, including:

1. Ovalbumin (54%): This is the major protein found in egg whites and is responsible for their white color. It has various functions such as providing nutrition, maintaining the structural integrity of the egg, and protecting the egg from bacteria.
2. Conalbumin (13%): Also known as ovotransferrin, this protein plays a role in the defense against microorganisms by binding to iron and making it unavailable for bacterial growth.
3. Ovomucoid (11%): This protein is resistant to digestion and helps protect the egg from being broken down by enzymes in the digestive tract of predators.
4. Lysozyme (3.5%): This protein has antibacterial properties and helps protect the egg from bacterial infection.
5. Globulins (4%): These are a group of simple proteins found in egg whites that have various functions such as providing nutrition, maintaining the structural integrity of the egg, and protecting the egg from bacteria.
6. Avidin (0.05%): This protein binds to biotin, a vitamin, making it unavailable for use by the body. However, cooking denatures avidin and makes the biotin available again.

Egg proteins are highly nutritious and contain all nine essential amino acids, making them a complete source of protein. They are also low in fat and cholesterol, making them a popular choice for those following a healthy diet.

Microinjection is a medical technique that involves the use of a fine, precise needle to inject small amounts of liquid or chemicals into microscopic structures, cells, or tissues. This procedure is often used in research settings to introduce specific substances into individual cells for study purposes, such as introducing DNA or RNA into cell nuclei to manipulate gene expression.

In clinical settings, microinjections may be used in various medical and cosmetic procedures, including:

1. Intracytoplasmic Sperm Injection (ICSI): A type of assisted reproductive technology where a single sperm is injected directly into an egg to increase the chances of fertilization during in vitro fertilization (IVF) treatments.
2. Botulinum Toxin Injections: Microinjections of botulinum toxin (Botox, Dysport, or Xeomin) are used for cosmetic purposes to reduce wrinkles and fine lines by temporarily paralyzing the muscles responsible for their formation. They can also be used medically to treat various neuromuscular disorders, such as migraines, muscle spasticity, and excessive sweating (hyperhidrosis).
3. Drug Delivery: Microinjections may be used to deliver drugs directly into specific tissues or organs, bypassing the systemic circulation and potentially reducing side effects. This technique can be particularly useful in treating localized pain, delivering growth factors for tissue regeneration, or administering chemotherapy agents directly into tumors.
4. Gene Therapy: Microinjections of genetic material (DNA or RNA) can be used to introduce therapeutic genes into cells to treat various genetic disorders or diseases, such as cystic fibrosis, hemophilia, or cancer.

Overall, microinjection is a highly specialized and precise technique that allows for the targeted delivery of substances into small structures, cells, or tissues, with potential applications in research, medical diagnostics, and therapeutic interventions.

Embryo implantation is the process by which a fertilized egg, or embryo, becomes attached to the wall of the uterus (endometrium) and begins to receive nutrients from the mother's blood supply. This process typically occurs about 6-10 days after fertilization and is a critical step in the establishment of a successful pregnancy.

During implantation, the embryo secretes enzymes that help it to burrow into the endometrium, while the endometrium responds by producing receptors for the embryo's enzymes and increasing blood flow to the area. The embryo then begins to grow and develop, eventually forming the placenta, which will provide nutrients and oxygen to the developing fetus throughout pregnancy.

Implantation is a complex process that requires precise timing and coordination between the embryo and the mother's body. Factors such as age, hormonal imbalances, and uterine abnormalities can affect implantation and increase the risk of miscarriage or difficulty becoming pregnant.

Fertility is the natural ability to conceive or to cause conception of offspring. In humans, it is the capacity of a woman and a man to reproduce through sexual reproduction. For women, fertility usually takes place during their reproductive years, which is from adolescence until menopause. A woman's fertility depends on various factors including her age, overall health, and the health of her reproductive system.

For men, fertility can be affected by a variety of factors such as age, genetics, general health, sexual function, and environmental factors that may affect sperm production or quality. Factors that can negatively impact male fertility include exposure to certain chemicals, radiation, smoking, alcohol consumption, drug use, and sexually transmitted infections (STIs).

Infertility is a common medical condition affecting about 10-15% of couples trying to conceive. Infertility can be primary or secondary. Primary infertility refers to the inability to conceive after one year of unprotected sexual intercourse, while secondary infertility refers to the inability to conceive following a previous pregnancy.

Infertility can be treated with various medical and surgical interventions depending on the underlying cause. These may include medications to stimulate ovulation, intrauterine insemination (IUI), in vitro fertilization (IVF), or surgery to correct anatomical abnormalities.

The vitelline membrane is a thin, transparent, flexible, and protective membrane that surrounds the yolk in bird, reptile, and some insect eggs. It provides nutrition and physical protection to the developing embryo during incubation. In medical terms, it is not directly relevant as it does not have a counterpart or equivalent structure in mammalian embryology.

Embryonic and fetal development is the process of growth and development that occurs from fertilization of the egg (conception) to birth. The terms "embryo" and "fetus" are used to describe different stages of this development:

* Embryonic development: This stage begins at fertilization and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (zygote) divides and forms a blastocyst, which implants in the uterus and begins to develop into a complex structure called an embryo. The embryo consists of three layers of cells that will eventually form all of the organs and tissues of the body. During this stage, the basic structures of the body, including the nervous system, heart, and gastrointestinal tract, begin to form.
* Fetal development: This stage begins at the end of the 8th week of pregnancy and continues until birth. During this time, the embryo is called a fetus, and it grows and develops rapidly. The organs and tissues that were formed during the embryonic stage continue to mature and become more complex. The fetus also begins to move and kick, and it can hear and respond to sounds from outside the womb.

Overall, embryonic and fetal development is a complex and highly regulated process that involves the coordinated growth and differentiation of cells and tissues. It is a critical period of development that lays the foundation for the health and well-being of the individual throughout their life.

Parthenogenesis is a form of asexual reproduction in which offspring develop from unfertilized eggs or ovums. It occurs naturally in some plant and insect species, as well as a few vertebrates such as reptiles and fish. Parthenogenesis does not involve the fusion of sperm and egg cells; instead, the development of offspring is initiated by some other trigger, such as a chemical or physical stimulus. This type of reproduction results in offspring that are genetically identical to the parent organism. In humans and other mammals, parthenogenesis is not a natural occurrence and would require scientific intervention to induce.

A sperm head is the anterior (front) part of a spermatozoon, which contains the genetic material (DNA). It is covered by a protein layer called the acrosome, which plays a crucial role in fertilization. The sperm head is followed by the midpiece and the tail, which provide mobility to the sperm for its journey towards the egg.

Pregnancy outcome refers to the final result or status of a pregnancy, including both the health of the mother and the newborn baby. It can be categorized into various types such as:

1. Live birth: The delivery of one or more babies who show signs of life after separation from their mother.
2. Stillbirth: The delivery of a baby who has died in the womb after 20 weeks of pregnancy.
3. Miscarriage: The spontaneous loss of a pregnancy before the 20th week.
4. Abortion: The intentional termination of a pregnancy before the fetus can survive outside the uterus.
5. Ectopic pregnancy: A pregnancy that develops outside the uterus, usually in the fallopian tube, which is not viable and requires medical attention.
6. Preterm birth: The delivery of a baby before 37 weeks of gestation, which can lead to various health issues for the newborn.
7. Full-term birth: The delivery of a baby between 37 and 42 weeks of gestation.
8. Post-term pregnancy: The delivery of a baby after 42 weeks of gestation, which may increase the risk of complications for both mother and baby.

The pregnancy outcome is influenced by various factors such as maternal age, health status, lifestyle habits, genetic factors, and access to quality prenatal care.

Semen preservation is the process of collecting, liquefying, testing, and storing semen samples for future use in assisted reproductive technologies (ART) such as artificial insemination (AI), in vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI). The semen sample is usually collected through masturbation, and then it is mixed with a cryoprotectant solution to prevent damage during the freezing and thawing process. After that, the sample is divided into straws or vials and frozen in liquid nitrogen tanks at temperatures below -196°C. Properly preserved semen can be stored for many years without significant loss of quality or fertility potential. Semen preservation is often recommended for men who are about to undergo medical treatments that may affect their sperm production or fertility, such as chemotherapy or radiation therapy, or for those who wish to postpone fatherhood for personal or medical reasons.

Oocyte retrieval is a medical procedure that is performed to obtain mature eggs (oocytes) from the ovaries of a female patient, typically for the purpose of assisted reproductive technologies (ART) such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

During the procedure, which is usually done under sedation or anesthesia, a thin needle is inserted through the vaginal wall and guided into the ovarian follicles using ultrasound imaging. The mature eggs are then gently aspirated from the follicles and collected in a test tube.

Oocyte retrieval is typically performed after several days of hormonal stimulation, which helps to promote the development and maturation of multiple eggs within the ovaries. After the procedure, the eggs are examined for maturity and quality before being fertilized with sperm in the laboratory. The resulting embryos are then transferred to the uterus or frozen for future use.

It's important to note that oocyte retrieval carries some risks, including bleeding, infection, and damage to surrounding organs. However, these complications are generally rare and can be minimized with careful monitoring and skilled medical care.

Oogenesis is the biological process of formation and maturation of female gametes, or ova or egg cells, in the ovary. It begins during fetal development and continues throughout a woman's reproductive years. The process involves the division and differentiation of a germ cell (oogonium) into an immature ovum (oocyte), which then undergoes meiotic division to form a mature ovum capable of being fertilized by sperm.

The main steps in oogenesis include:

1. Multiplication phase: The oogonia divide mitotically to increase their number.
2. Growth phase: One of the oogonia becomes primary oocyte and starts to grow, accumulating nutrients and organelles required for future development.
3. First meiotic division: The primary oocyte undergoes an incomplete first meiotic division, resulting in two haploid cells - a secondary oocyte and a smaller cell called the first polar body. This division is arrested in prophase I until puberty.
4. Second meiotic division: At ovulation or just before fertilization, the secondary oocyte completes the second meiotic division, producing another small cell, the second polar body, and a mature ovum (egg) with 23 chromosomes.
5. Fertilization: The mature ovum can be fertilized by a sperm, restoring the normal diploid number of chromosomes in the resulting zygote.

Oogenesis is a complex and highly regulated process that involves various hormonal signals and cellular interactions to ensure proper development and maturation of female gametes for successful reproduction.

Artificial insemination (AI) is a medical procedure that involves the introduction of sperm into a female's cervix or uterus for the purpose of achieving pregnancy. This procedure can be performed using sperm from a partner or a donor. It is often used when there are issues with male fertility, such as low sperm count or poor sperm motility, or in cases where natural conception is not possible due to various medical reasons.

There are two types of artificial insemination: intracervical insemination (ICI) and intrauterine insemination (IUI). ICI involves placing the sperm directly into the cervix, while IUI involves placing the sperm directly into the uterus using a catheter. The choice of procedure depends on various factors, including the cause of infertility and the preferences of the individuals involved.

Artificial insemination is a relatively simple and low-risk procedure that can be performed in a doctor's office or clinic. It may be combined with fertility drugs to increase the chances of pregnancy. The success rate of artificial insemination varies depending on several factors, including the age and fertility of the individuals involved, the cause of infertility, and the type of procedure used.

Follicular fluid is the fluid that accumulates within the follicle (a small sac or cyst) in the ovary where an egg matures. This fluid contains various chemicals, hormones, and proteins that support the growth and development of the egg cell. It also contains metabolic waste products and other substances from the granulosa cells (the cells that surround the egg cell within the follicle). Follicular fluid is often analyzed in fertility treatments and studies as it can provide valuable information about the health and viability of the egg cell.

Reproductive techniques refer to various methods and procedures used to assist individuals or couples in achieving pregnancy, carrying a pregnancy to term, or preserving fertility. These techniques can be broadly categorized into assisted reproductive technology (ART) and fertility preservation.

Assisted reproductive technology (ART) includes procedures such as:

1. In vitro fertilization (IVF): A process where an egg is fertilized by sperm outside the body in a laboratory dish, and then the resulting embryo is transferred to a woman's uterus.
2. Intracytoplasmic sperm injection (ICSI): A procedure where a single sperm is directly injected into an egg to facilitate fertilization.
3. Embryo culture and cryopreservation: The process of growing embryos in a laboratory for a few days before freezing them for later use.
4. Donor gametes: Using eggs, sperm, or embryos from a known or anonymous donor to achieve pregnancy.
5. Gestational surrogacy: A method where a woman carries and gives birth to a baby for another individual or couple who cannot carry a pregnancy themselves.

Fertility preservation techniques include:

1. Sperm banking: The process of freezing and storing sperm for future use in artificial reproduction.
2. Egg (oocyte) freezing: A procedure where a woman's eggs are extracted, frozen, and stored for later use in fertility treatments.
3. Embryo freezing: The cryopreservation of embryos created through IVF for future use.
4. Ovarian tissue cryopreservation: The freezing and storage of ovarian tissue to restore fertility after cancer treatment or other conditions that may affect fertility.
5. Testicular tissue cryopreservation: The collection and storage of testicular tissue in prepubertal boys undergoing cancer treatment to preserve their future fertility potential.

Urochordata is a phylum in the animal kingdom that includes sessile, marine organisms commonly known as tunicates or sea squirts. The name "Urochordata" means "tail-cord animals," which refers to the notochord, a flexible, rod-like structure found in the tails of these animals during their larval stage.

Tunicates are filter feeders that draw water into their bodies through a siphon and extract plankton and other organic particles for nutrition. They have a simple body plan, consisting of a protective outer covering called a tunic, an inner body mass with a muscular pharynx, and a tail-like structure called the post-anal tail.

Urochordates are of particular interest to biologists because they are considered to be the closest living relatives to vertebrates (animals with backbones), sharing a common ancestor with them around 550 million years ago. Despite their simple appearance, tunicates have complex developmental processes that involve the formation of notochords, dorsal nerve cords, and other structures that are similar to those found in vertebrate embryos.

Overall, Urochordata is a fascinating phylum that provides important insights into the evolutionary history of animals and their diverse body plans.

I believe you may be mistakenly using the term "starfish" to refer to a medical condition. If so, the correct term is likely " asterixis," which is a medical sign characterized by rapid, rhythmic flapping or tremulous movements of the hands when they are extended and the wrist is dorsiflexed (held with the back of the hand facing upwards). This is often seen in people with certain neurological conditions such as liver failure or certain types of poisoning.

However, if you are indeed referring to the marine animal commonly known as a "starfish," there isn't a specific medical definition for it. Starfish, also known as sea stars, are marine animals belonging to the class Asteroidea in the phylum Echinodermata. They have a distinctive shape with five or more arms radiating from a central disc, and they move slowly along the ocean floor using their tube feet. Some species of starfish have the ability to regenerate lost body parts, including entire limbs or even their central disc.

A mammalian embryo is the developing offspring of a mammal, from the time of implantation of the fertilized egg (blastocyst) in the uterus until the end of the eighth week of gestation. During this period, the embryo undergoes rapid cell division and organ differentiation to form a complex structure with all the major organs and systems in place. This stage is followed by fetal development, which continues until birth. The study of mammalian embryos is important for understanding human development, evolution, and reproductive biology.

The Fallopian tubes, also known as uterine tubes or oviducts, are a pair of slender tubular structures in the female reproductive system. They play a crucial role in human reproduction by providing a passageway for the egg (ovum) from the ovary to the uterus (womb).

Each Fallopian tube is typically around 7.6 to 10 centimeters long and consists of four parts: the interstitial part, the isthmus, the ampulla, and the infundibulum. The fimbriated end of the infundibulum, which resembles a fringe or frill, surrounds and captures the released egg from the ovary during ovulation.

Fertilization usually occurs in the ampulla when sperm meets the egg after sexual intercourse. Once fertilized, the zygote (fertilized egg) travels through the Fallopian tube toward the uterus for implantation and further development. The cilia lining the inner surface of the Fallopian tubes help propel the egg and the zygote along their journey.

In some cases, abnormalities or blockages in the Fallopian tubes can lead to infertility or ectopic pregnancies, which are pregnancies that develop outside the uterus, typically within the Fallopian tube itself.

Meiosis is a type of cell division that results in the formation of four daughter cells, each with half the number of chromosomes as the parent cell. It is a key process in sexual reproduction, where it generates gametes or sex cells (sperm and eggs).

The process of meiosis involves one round of DNA replication followed by two successive nuclear divisions, meiosis I and meiosis II. In meiosis I, homologous chromosomes pair, form chiasma and exchange genetic material through crossing over, then separate from each other. In meiosis II, sister chromatids separate, leading to the formation of four haploid cells. This process ensures genetic diversity in offspring by shuffling and recombining genetic information during the formation of gametes.

An ovule is the structure in female plants (including gymnosperms and angiosperms) that contains the female gametophyte and gives rise to the seed after fertilization. It consists of a protective outer layer called the integument, enclosing a small mass of tissue called the nucellus, within which is located the embryo sac or female germ unit.

The embryo sac contains the egg cell (oocyte), two synergids that assist in fertilization, and three antipodal cells at the opposite end. Upon fertilization of the egg cell by a male gamete from pollen, the zygote forms, which develops into an embryo within the ovule. The other male gamete fuses with the central cell (containing two polar nuclei) to form the endosperm, which serves as nutritive tissue for the developing embryo.

Once mature, the ovule transforms into a seed, enclosed by a seed coat formed from the integuments. The seed contains the developed embryo and stored food reserves (endosperm) that support its initial growth after germination.

An ovarian follicle is a fluid-filled sac in the ovary that contains an immature egg or ovum (oocyte). It's a part of the female reproductive system and plays a crucial role in the process of ovulation.

Ovarian follicles start developing in the ovaries during fetal development, but only a small number of them will mature and release an egg during a woman's reproductive years. The maturation process is stimulated by hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

There are different types of ovarian follicles, including primordial, primary, secondary, and tertiary or Graafian follicles. The Graafian follicle is the mature follicle that ruptures during ovulation to release the egg into the fallopian tube, where it may be fertilized by sperm.

It's important to note that abnormal growth or development of ovarian follicles can lead to conditions like polycystic ovary syndrome (PCOS) and ovarian cancer.

Menotropins are a preparation of natural follicle-stimulating hormone (FSH) and luteinizing hormone (LH) derived from the urine of postmenopausal women. They are used in infertility treatment to stimulate the development of multiple follicles in the ovaries, leading to an increased chance of pregnancy through assisted reproductive technologies such as in vitro fertilization (IVF).

Menotropins contain a mixture of FSH and LH in a ratio that is similar to the natural hormone levels found in the human body. The FSH component stimulates the growth and development of follicles in the ovaries, while the LH component triggers ovulation when the follicles have matured.

Menotropins are typically administered by subcutaneous injection and are available under various brand names, such as Menopur and Repronex. The use of menotropins requires careful medical supervision to monitor the response of the ovaries and to minimize the risk of complications such as ovarian hyperstimulation syndrome (OHSS).

Ovulation is the medical term for the release of a mature egg from an ovary during a woman's menstrual cycle. The released egg travels through the fallopian tube where it may be fertilized by sperm if sexual intercourse has occurred recently. If the egg is not fertilized, it will break down and leave the body along with the uterine lining during menstruation. Ovulation typically occurs around day 14 of a 28-day menstrual cycle, but the timing can vary widely from woman to woman and even from cycle to cycle in the same woman.

During ovulation, there are several physical changes that may occur in a woman's body, such as an increase in basal body temperature, changes in cervical mucus, and mild cramping or discomfort on one side of the lower abdomen (known as mittelschmerz). These symptoms can be used to help predict ovulation and improve the chances of conception.

It's worth noting that some medical conditions, such as polycystic ovary syndrome (PCOS) or premature ovarian failure, may affect ovulation and make it difficult for a woman to become pregnant. In these cases, medical intervention may be necessary to help promote ovulation and increase the chances of conception.

Chorionic Gonadotropin (hCG) is a hormone that is produced during pregnancy. It is produced by the placenta after implantation of the fertilized egg in the uterus. The main function of hCG is to prevent the disintegration of the corpus luteum, which is a temporary endocrine structure that forms in the ovary after ovulation and produces progesterone during early pregnancy. Progesterone is essential for maintaining the lining of the uterus and supporting the pregnancy.

hCG can be detected in the blood or urine as early as 10 days after conception, and its levels continue to rise throughout the first trimester of pregnancy. In addition to its role in maintaining pregnancy, hCG is also used as a clinical marker for pregnancy and to monitor certain medical conditions such as gestational trophoblastic diseases.

Semen is a complex, whitish fluid that is released from the male reproductive system during ejaculation. It is produced by several glands, including the seminal vesicles, prostate gland, and bulbourethral glands. Semen contains several components, including sperm (the male reproductive cells), as well as various proteins, enzymes, vitamins, and minerals. Its primary function is to transport sperm through the female reproductive tract during sexual intercourse, providing nutrients and aiding in the protection of the sperm as they travel toward the egg for fertilization.

Oocyte donation is a medical procedure in which mature oocytes (or immature oocytes that are matured in the lab) are donated by one woman to another woman for the purpose of assisted reproduction. The recipient woman typically receives hormonal treatments to prepare her uterus for embryo implantation. The donated oocytes are then fertilized with sperm from the recipient's partner or a sperm donor in a laboratory, and the resulting embryos are transferred into the recipient's uterus.

Oocyte donation is often recommended for women who have poor ovarian function or who have a high risk of passing on genetic disorders to their offspring. It is also used in cases where previous attempts at in vitro fertilization (IVF) using the woman's own eggs have been unsuccessful.

The process of oocyte donation involves rigorous screening and evaluation of both the donor and recipient, including medical, psychological, and genetic evaluations, to ensure the safety and success of the procedure. The donor's ovaries are stimulated with hormonal medications to produce multiple mature oocytes, which are then retrieved through a minor surgical procedure.

Overall, oocyte donation is a complex and emotionally charged process that requires careful consideration and counseling for both the donor and recipient. It offers hope for many women who would otherwise be unable to conceive a biological child.

Cumulus cells are a type of specialized cell that surround and support the egg (oocyte) in the ovary of female mammals, including humans. These cells are located in the cumulus oophorus, which is a cluster of cells that surrounds and protects the mature egg within the follicle.

Cumulus cells play an important role in the process of fertilization by providing nutrients to the developing egg and helping to regulate its growth and development. They also help to facilitate communication between the egg and the surrounding follicular cells, which is necessary for the release of the mature egg from the ovary during ovulation.

In addition to their role in reproduction, cumulus cells have been studied for their potential use in various medical applications, including as a source of stem cells for therapeutic purposes. However, more research is needed to fully understand the properties and potential uses of these cells.

Acrosin is a proteolytic enzyme that is found in the acrosome, which is a cap-like structure located on the anterior part of the sperm head. This enzyme plays an essential role in the fertilization process by helping the sperm to penetrate the zona pellucida, which is the glycoprotein coat surrounding the egg.

Acrosin is released from the acrosome when the sperm encounters the zona pellucida, and it begins to digest the glycoproteins in the zona pellucida, creating a path for the sperm to reach and fuse with the egg's plasma membrane. This enzyme is synthesized and stored in the acrosome during spermatogenesis and is activated during the acrosome reaction, which is a critical event in fertilization.

Defects in acrosin function or regulation have been implicated in male infertility, making it an important area of research in reproductive biology.

Assisted reproductive techniques (ART) are medical procedures that involve the handling of human sperm and ova to establish a pregnancy. These techniques are used when other methods of achieving pregnancy have failed or are not available. Examples of ART include in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), gamete intrafallopian transfer (GIFT), and zygote intrafallopian transfer (ZIFT). These procedures may be used to treat infertility, prevent genetic disorders, or to help same-sex couples or single people have children. It is important to note that the use of ART can involve significant physical, emotional, and financial costs, and it may not always result in a successful pregnancy.

Embryo culture techniques refer to the methods and procedures used to maintain and support the growth and development of an embryo outside of the womb, typically in a laboratory setting. These techniques are often used in the context of assisted reproductive technologies (ART), such as in vitro fertilization (IVF).

The process typically involves fertilizing an egg with sperm in a laboratory dish and then carefully monitoring and maintaining the resulting embryo in a specialized culture medium that provides the necessary nutrients, hormones, and other factors to support its development. The culture medium is usually contained within an incubator that maintains optimal temperature, humidity, and gas concentrations to mimic the environment inside the body.

Embryologists may use various embryo culture techniques depending on the stage of development and the specific needs of the embryo. For example, some techniques involve culturing the embryo in a single layer, while others may use a technique called "co-culture" that involves growing the embryo on a layer of cells to provide additional support and nutrients.

The goal of embryo culture techniques is to promote the healthy growth and development of the embryo, increasing the chances of a successful pregnancy and live birth. However, it's important to note that these techniques are not without risk, and there are potential ethical considerations surrounding the use of ART and embryo culture.

Sperm count, also known as sperm concentration, is the number of sperm present in a given volume of semen. The World Health Organization (WHO) previously defined a normal sperm count as at least 20 million sperm per milliliter of semen. However, more recent studies suggest that fertility may be affected even when sperm counts are slightly lower than this threshold. It's important to note that sperm count is just one factor among many that can influence male fertility. Other factors, such as sperm motility (the ability of sperm to move properly) and morphology (the shape of the sperm), also play crucial roles in successful conception.

Sperm transport refers to the series of events that occur from the production of sperm in the testes to their release into the female reproductive tract during sexual intercourse. This process involves several stages:

1. Spermatogenesis: The production of sperm cells (spermatozoa) takes place in the seminiferous tubules within the testes.
2. Maturation: The newly produced sperm are immature and incapable of fertilization. They undergo a maturation process as they move through the epididymis, where they acquire motility and the ability to fertilize an egg.
3. Ejaculation: During sexual arousal, sperm are mixed with seminal fluid produced by the seminal vesicles, prostate gland, and bulbourethral glands to form semen. This mixture is propelled through the urethra during orgasm (ejaculation) and released from the penis into the female reproductive tract.
4. Transport within the female reproductive tract: Once inside the female reproductive tract, sperm must travel through the cervix, uterus, and fallopian tubes to reach the site of fertilization, the ampullary-isthmic junction of the fallopian tube. This journey can take several hours to a few days.
5. Capacitation: During their transport within the female reproductive tract, sperm undergo further changes called capacitation, which prepares them for fertilization by increasing their motility and making them more responsive to the egg's chemical signals.
6. Acrosome reaction: The final step in sperm transport is the acrosome reaction, where the sperm releases enzymes from the acrosome (a cap-like structure on the head of the sperm) to penetrate and fertilize the egg.

Insemination, in a medical context, refers to the introduction of semen into the reproductive system of a female for the purpose of achieving pregnancy. This can be done through various methods including intracervical insemination (ICI), intrauterine insemination (IUI), and in vitro fertilization (IVF).

Intracervical insemination involves placing the semen at the cervix, the opening to the uterus. Intrauterine insemination involves placing the sperm directly into the uterus using a catheter. In vitro fertilization is a more complex process where the egg and sperm are combined in a laboratory dish and then transferred to the uterus.

Insemination is often used in cases of infertility, either because of male or female factors, or unexplained infertility. It can also be used for those who wish to become pregnant but do not have a partner, such as single women and same-sex female couples.

Echinodermata is a phylum in the animal kingdom that includes various marine organisms such as sea stars, sea urchins, sand dollars, brittle stars, and sea cucumbers. The name Echinodermata comes from the Greek words "echinos," meaning spiny, and "derma," meaning skin, which refers to the characteristic spiny skin of many echinoderms.

Echinoderms are bilaterally symmetrical as larvae but become radially symmetrical as adults, with their bodies organized around a central axis. They have a unique water vascular system that helps them move and respire, and most species have specialized structures called pedicellariae that help them clean and defend themselves.

Echinoderms are also known for their ability to regenerate lost body parts, and some species can even undergo asexual reproduction through fragmentation. They play important ecological roles in marine ecosystems, including grazing on algae and other organisms, breaking down organic matter, and serving as prey for larger animals.

Superovulation, also known as controlled ovarian stimulation (COS), refers to the process of inducing the development and release of multiple mature ova (eggs) from the ovaries during a single reproductive cycle. This is achieved through the administration of exogenous gonadotropins or other fertility medications, which stimulate the ovarian follicles to grow and mature beyond the normal number. Superovulation is commonly used in assisted reproductive technologies (ART) such as in vitro fertilization (IVF) to increase the chances of successful conception by obtaining a larger number of ova for fertilization and embryo transfer.

In vitro oocyte maturation (IVM) techniques refer to the process of stimulating and promoting the development and maturation of immature oocytes (eggs) outside of the human body, in a laboratory setting. This procedure is often used in assisted reproductive technology (ART) for individuals or couples who may have difficulty conceiving due to various reasons such as premature ovarian failure, polycystic ovary syndrome (PCOS), or those undergoing cancer treatment.

The IVM process involves the retrieval of immature oocytes from the ovaries, usually through a minor surgical procedure called transvaginal oocyte retrieval. The immature oocytes are then cultured in a laboratory and exposed to specific hormones and nutrients that stimulate their growth and maturation. Once the oocytes have reached full maturity, they can be fertilized with sperm through intracytoplasmic sperm injection (ICSI) or other methods, and the resulting embryos can be transferred to a woman's uterus in the hope of achieving a successful pregnancy.

IVM techniques offer several advantages over traditional in vitro fertilization (IVF) procedures, including reduced medication doses, shorter treatment durations, and lower costs. Additionally, IVM may help minimize the risk of ovarian hyperstimulation syndrome (OHSS), a potentially serious complication associated with conventional ART treatments. However, IVM is still considered an experimental procedure in many countries and requires further research to establish its safety and efficacy for widespread clinical use.

An ovary is a part of the female reproductive system in which ova or eggs are produced through the process of oogenesis. They are a pair of solid, almond-shaped structures located one on each side of the uterus within the pelvic cavity. Each ovary measures about 3 to 5 centimeters in length and weighs around 14 grams.

The ovaries have two main functions: endocrine (hormonal) function and reproductive function. They produce and release eggs (ovulation) responsible for potential fertilization and development of an embryo/fetus during pregnancy. Additionally, they are essential in the production of female sex hormones, primarily estrogen and progesterone, which regulate menstrual cycles, sexual development, and reproduction.

During each menstrual cycle, a mature egg is released from one of the ovaries into the fallopian tube, where it may be fertilized by sperm. If not fertilized, the egg, along with the uterine lining, will be shed, leading to menstruation.

A live birth is the complete expulsion or extraction from its mother of a product of human conception, irrespective of the duration of the pregnancy, that, after such separation, breathes or shows any other evidence of life - such as beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles - whether or not the umbilical cord has been cut or the placenta is attached.

This definition is used by the World Health Organization (WHO) and most national statistical agencies to distinguish live births from stillbirths. It's important to note that in some medical contexts, a different definition of live birth may be used.

Reproduction, in the context of biology and medicine, refers to the process by which organisms produce offspring. It is a complex process that involves the creation, development, and growth of new individuals from parent organisms. In sexual reproduction, this process typically involves the combination of genetic material from two parents through the fusion of gametes (sex cells) such as sperm and egg cells. This results in the formation of a zygote, which then develops into a new individual with a unique genetic makeup.

In contrast, asexual reproduction does not involve the fusion of gametes and can occur through various mechanisms such as budding, fragmentation, or parthenogenesis. Asexual reproduction results in offspring that are genetically identical to the parent organism.

Reproduction is a fundamental process that ensures the survival and continuation of species over time. It is also an area of active research in fields such as reproductive medicine, where scientists and clinicians work to understand and address issues related to human fertility, contraception, and genetic disorders.

Follicle-Stimulating Hormone (FSH) is a glycoprotein hormone secreted and released by the anterior pituitary gland. In females, it promotes the growth and development of ovarian follicles in the ovary, which ultimately leads to the maturation and release of an egg (ovulation). In males, FSH stimulates the testes to produce sperm. It works in conjunction with luteinizing hormone (LH) to regulate reproductive processes. The secretion of FSH is controlled by the hypothalamic-pituitary-gonadal axis and its release is influenced by the levels of gonadotropin-releasing hormone (GnRH), estrogen, inhibin, and androgens.

The epididymis is a tightly coiled tube located on the upper and posterior portion of the testicle that serves as the site for sperm maturation and storage. It is an essential component of the male reproductive system. The epididymis can be divided into three parts: the head (where newly produced sperm enter from the testicle), the body, and the tail (where mature sperm exit and are stored). Any abnormalities or inflammation in the epididymis may lead to discomfort, pain, or infertility.

Oligospermia is a medical term used to describe a condition in which the semen contains a lower than normal number of sperm. Generally, a sperm count of less than 15 million sperm per milliliter (ml) of semen is considered to be below the normal range.

Oligospermia can make it more difficult for a couple to conceive naturally and may require medical intervention such as intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF). The condition can result from various factors, including hormonal imbalances, genetic abnormalities, varicocele, environmental factors, and certain medications.

It's important to note that oligospermia is not the same as azoospermia, which is a condition where there is no sperm present in the semen at all.

A pollen tube is a slender, tubular structure that grows out from the germinated grain of pollen and transports the male gametes (sperm cells) to the female reproductive organ in seed plants. This process is known as double fertilization, which occurs in angiosperms (flowering plants).

The pollen tube elongates through the stigma and style of the pistil, following a path towards the ovule. Once it reaches the ovule, the generative cell within the pollen tube divides to form two sperm cells. One sperm fertilizes the egg cell, forming a zygote, while the other sperm fuses with the central cell of the embryo sac, leading to the formation of endosperm - a nutritive tissue for the developing embryo.

In summary, a pollen tube is a crucial component in the reproductive process of seed plants, facilitating the transfer of male gametes to female gametes and ultimately resulting in fertilization and seed development.

Micromanipulation is a term used in the field of medicine, specifically in assisted reproductive technologies (ARTs) such as in vitro fertilization (IVF). It refers to a technique that involves the manipulation of oocytes (human eggs), sperm, and/or embryos under a microscope using micromanipulative tools and equipment.

The most common form of micromanipulation is intracytoplasmic sperm injection (ICSI), where a single sperm is selected and injected directly into the cytoplasm of an oocyte to facilitate fertilization. Other forms of micromanipulation include assisted hatching (AH), where a small opening is made in the zona pellucida (the protective layer surrounding the embryo) to help the embryo hatch and implant into the uterus, and embryo biopsy, which involves removing one or more cells from an embryo for genetic testing.

Micromanipulation requires specialized training and equipment and is typically performed in IVF laboratories by experienced embryologists. The goal of micromanipulation is to improve the chances of successful fertilization, implantation, and pregnancy, particularly in cases where conventional methods have been unsuccessful or when there are specific fertility issues, such as male factor infertility or genetic disorders.

Multiple pregnancy is a type of gestation where more than one fetus is carried simultaneously in the uterus. The most common forms of multiple pregnancies are twins (two fetuses), triplets (three fetuses), and quadruplets (four fetuses). Multiple pregnancies can occur when a single fertilized egg splits into two or more embryos (monozygotic) or when more than one egg is released and gets fertilized during ovulation (dizygotic). The risk of multiple pregnancies increases with the use of assisted reproductive technologies, such as in vitro fertilization. Multiple pregnancies are associated with higher risks for both the mother and the fetuses, including preterm labor, low birth weight, and other complications.

Fallopian tube diseases refer to conditions that affect the function or structure of the Fallopian tubes, which are a pair of narrow tubes that transport the egg from the ovaries to the uterus during ovulation and provide a pathway for sperm to reach the egg for fertilization. Some common Fallopian tube diseases include:

1. Salpingitis: This is an inflammation of the Fallopian tubes, usually caused by an infection. The infection can be bacterial, viral, or fungal in origin and can lead to scarring, blockage, or damage to the Fallopian tubes.
2. Hydrosalpinx: This is a condition where one or both of the Fallopian tubes become filled with fluid, leading to swelling and distension of the tube. The cause of hydrosalpinx can be infection, endometriosis, or previous surgery.
3. Endometriosis: This is a condition where the tissue that lines the inside of the uterus grows outside of it, including on the Fallopian tubes. This can lead to scarring, adhesions, and blockage of the tubes.
4. Ectopic pregnancy: This is a pregnancy that develops outside of the uterus, usually in the Fallopian tube. An ectopic pregnancy can cause the Fallopian tube to rupture, leading to severe bleeding and potentially life-threatening complications.
5. Tubal ligation: This is a surgical procedure that involves blocking or cutting the Fallopian tubes to prevent pregnancy. In some cases, tubal ligation can lead to complications such as ectopic pregnancy or tubal sterilization syndrome, which is a condition where the fallopian tubes reconnect and allow for pregnancy to occur.

These conditions can cause infertility, chronic pain, and other health problems, and may require medical or surgical treatment.

A nonmammalian embryo refers to the developing organism in animals other than mammals, from the fertilized egg (zygote) stage until hatching or birth. In nonmammalian species, the developmental stages and terminology differ from those used in mammals. The term "embryo" is generally applied to the developing organism up until a specific stage of development that is characterized by the formation of major organs and structures. After this point, the developing organism is referred to as a "larva," "juvenile," or other species-specific terminology.

The study of nonmammalian embryos has played an important role in our understanding of developmental biology and evolutionary developmental biology (evo-devo). By comparing the developmental processes across different animal groups, researchers can gain insights into the evolutionary origins and diversification of body plans and structures. Additionally, nonmammalian embryos are often used as model systems for studying basic biological processes, such as cell division, gene regulation, and pattern formation.

The "sperm tail" is also known as the flagellum, which is a whip-like structure that enables the sperm to move or swim through fluid. The human sperm tail is made up of nine microtubule doublets and a central pair of microtubules, which are surrounded by a mitochondrial sheath that provides energy for its movement. This complex structure allows the sperm to navigate through the female reproductive tract in order to reach and fertilize an egg.

Immunologic contraception refers to the use of the immune system to prevent pregnancy. This is achieved by stimulating the production of antibodies against specific proteins or hormones that are essential for fertilization and implantation of a fertilized egg in the uterus. The most well-known example of immunologic contraception is the development of a vaccine that would induce an immune response against human chorionic gonadotropin (hCG), a hormone produced during pregnancy. By neutralizing hCG, the immune system could prevent the establishment and maintenance of pregnancy. However, this approach is still in the experimental stage and has not yet been approved for use in humans.

Ovarian Hyperstimulation Syndrome (OHSS) is a medical condition characterized by the enlargement of the ovaries and the accumulation of fluid in the abdominal cavity, which can occur as a complication of fertility treatments that involve the use of medications to stimulate ovulation.

In OHSS, the ovaries become swollen and may contain multiple follicles (small sacs containing eggs) that have developed in response to the hormonal stimulation. This can lead to the release of large amounts of vasoactive substances, such as vascular endothelial growth factor (VEGF), which can cause increased blood flow to the ovaries and fluid leakage from the blood vessels into the abdominal cavity.

Mild cases of OHSS may cause symptoms such as bloating, abdominal pain or discomfort, nausea, and diarrhea. More severe cases can lead to more serious complications, including blood clots, kidney failure, and respiratory distress. In extreme cases, hospitalization may be necessary to manage the symptoms of OHSS and prevent further complications.

OHSS is typically managed by monitoring the patient's symptoms and providing supportive care, such as fluid replacement and pain management. In severe cases, medication or surgery may be necessary to drain excess fluid from the abdominal cavity. Preventive measures, such as adjusting the dosage of fertility medications or canceling treatment cycles, may also be taken to reduce the risk of OHSS in high-risk patients.

Blastomeres are early stage embryonic cells that result from the initial rounds of cell division in a fertilized egg, also known as a zygote. These cells are typically smaller and have a more simple organization compared to more mature cells. They are important for the normal development of the embryo and contribute to the formation of the blastocyst, which is an early stage embryonic structure that will eventually give rise to the fetus. The process of cell division that produces blastomeres is called cleavage.

Ejaculation is the discharge of semen, typically accompanied by orgasm, during sexual activity. It occurs when the male reproductive system releases semen from the penis. This process is usually brought on by sexual arousal and stimulation, which cause the sperm-carrying vas deferens to contract and push the semen into the urethra, from where it is expelled through the tip of the penis.

There are two types of ejaculation:

1. **Reflex ejaculation**: This occurs when there is a high level of sexual excitement or stimulation, leading to an involuntary and automatic response.
2. **Premature ejaculation**: This refers to the condition where ejaculation happens too quickly, often before or shortly after penetration, causing distress and affecting sexual satisfaction for both partners.

It is essential to understand that a healthy male can experience variations in the timing of ejaculation throughout their life, influenced by factors such as age, stress levels, and overall health. If you have concerns about your ejaculation patterns or any related issues, it is recommended to consult a healthcare professional for advice and treatment options.

Metaphase is a phase in the cell division process (mitosis or meiosis) where the chromosomes align in the middle of the cell, also known as the metaphase plate or equatorial plane. During this stage, each chromosome consists of two sister chromatids attached to each other by a protein complex called the centromere. The spindle fibers from opposite poles of the cell attach to the centromeres of each chromosome, and through a process called congression, they align the chromosomes in the middle of the cell. This alignment allows for accurate segregation of genetic material during the subsequent anaphase stage.

I'm sorry for any confusion, but the term "germ cells" is typically used in the context of animals and humans, referring to the reproductive cells (sperm and eggs) that can give rise to new individuals. It is not commonly used to describe plants.

In plants, the terms often used to refer to the reproductive cells are "male gametophyte" and "female gametophyte." The male gametophyte produces sperm cells, while the female gametophyte produces egg cells. These gametophytes are found within the pollen grains (male) and ovules (female) of plants.

Therefore, there isn't a medical definition for "germ cells, plant," as the term is not applicable in this context.

Spermatids are immature sperm cells that are produced during the process of spermatogenesis in the male testes. They are the product of the final stage of meiosis, where a diploid spermatocyte divides into four haploid spermatids. Each spermatid then undergoes a series of changes, including the development of a tail for motility and the condensation of its nucleus to form a head containing the genetic material. Once this process is complete, the spermatids are considered mature spermatozoa and are capable of fertilizing an egg.

The testis, also known as the testicle, is a male reproductive organ that is part of the endocrine system. It is located in the scrotum, outside of the abdominal cavity. The main function of the testis is to produce sperm and testosterone, the primary male sex hormone.

The testis is composed of many tiny tubules called seminiferous tubules, where sperm are produced. These tubules are surrounded by a network of blood vessels, nerves, and supportive tissues. The sperm then travel through a series of ducts to the epididymis, where they mature and become capable of fertilization.

Testosterone is produced in the Leydig cells, which are located in the interstitial tissue between the seminiferous tubules. Testosterone plays a crucial role in the development and maintenance of male secondary sexual characteristics, such as facial hair, deep voice, and muscle mass. It also supports sperm production and sexual function.

Abnormalities in testicular function can lead to infertility, hormonal imbalances, and other health problems. Regular self-examinations and medical check-ups are recommended for early detection and treatment of any potential issues.

Female fertility agents are medications or treatments that are used to enhance or restore female fertility. They can work in various ways such as stimulating ovulation, improving the quality of eggs, facilitating the implantation of a fertilized egg in the uterus, or addressing issues related to the reproductive system.

Some examples of female fertility agents include:

1. Clomiphene citrate (Clomid, Serophene): This medication stimulates ovulation by causing the pituitary gland to release more follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
2. Gonadotropins: These are hormonal medications that contain FSH and LH, which stimulate the ovaries to produce mature eggs. Examples include human menopausal gonadotropin (hMG) and follicle-stimulating hormone (FSH).
3. Letrozole (Femara): This medication is an aromatase inhibitor that can be used off-label to stimulate ovulation in women who do not respond to clomiphene citrate.
4. Metformin (Glucophage): This medication is primarily used to treat type 2 diabetes, but it can also improve fertility in women with polycystic ovary syndrome (PCOS) by regulating insulin levels and promoting ovulation.
5. Bromocriptine (Parlodel): This medication is used to treat infertility caused by hyperprolactinemia, a condition characterized by high levels of prolactin in the blood.
6. Assisted reproductive technologies (ART): These include procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and gamete intrafallopian transfer (GIFT). They involve manipulating eggs and sperm outside the body to facilitate fertilization and implantation.

It is important to consult with a healthcare provider or reproductive endocrinologist to determine the most appropriate fertility agent for individual needs, as these medications can have side effects and potential risks.

Cryoprotective agents are substances that are used to protect biological material from damage during freezing and thawing. These agents work by reducing the amount of ice that forms in the cells, which can help to prevent the formation of damaging ice crystals. Commonly used cryoprotective agents include dimethyl sulfoxide (DMSO), glycerol, and ethylene glycol.

When biological material, such as cells or tissues, is cooled to very low temperatures for storage or transportation, the water in the cells can freeze and form ice crystals. These ice crystals can damage the cell membranes and other structures within the cell, leading to cell death. Cryoprotective agents help to prevent this by lowering the freezing point of the solution that the cells are stored in, which reduces the amount of ice that forms.

Cryoprotective agents are often used in the field of assisted reproductive technology (ART) to protect sperm, eggs, and embryos during freezing and thawing. They are also used in research settings to preserve cells and tissues for later use. It is important to note that while cryoprotective agents can help to reduce the amount of damage that occurs during freezing and thawing, they cannot completely prevent it. Therefore, it is important to carefully control the freezing and thawing process to minimize any potential harm to the biological material.

Cytoplasm is the material within a eukaryotic cell (a cell with a true nucleus) that lies between the nuclear membrane and the cell membrane. It is composed of an aqueous solution called cytosol, in which various organelles such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles are suspended. Cytoplasm also contains a variety of dissolved nutrients, metabolites, ions, and enzymes that are involved in various cellular processes such as metabolism, signaling, and transport. It is where most of the cell's metabolic activities take place, and it plays a crucial role in maintaining the structure and function of the cell.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Seminal plasma proteins are a group of proteins that are present in the seminal fluid, which is the liquid component of semen. These proteins originate primarily from the accessory sex glands, including the prostate, seminal vesicles, and bulbourethral glands, and play various roles in the maintenance of sperm function and fertility.

Some of the key functions of seminal plasma proteins include:

1. Nutrition: Seminal plasma proteins provide energy sources and essential nutrients to support sperm survival and motility during their journey through the female reproductive tract.
2. Protection: These proteins help protect sperm from oxidative stress, immune attack, and other environmental factors that could negatively impact sperm function or viability.
3. Lubrication: Seminal plasma proteins contribute to the formation of a fluid medium that facilitates the ejaculation and transport of sperm through the female reproductive tract.
4. Coagulation and liquefaction: Some seminal plasma proteins are involved in the initial coagulation and subsequent liquefaction of semen, which helps ensure proper sperm release and distribution during ejaculation.
5. Interaction with female reproductive system: Seminal plasma proteins can interact with components of the female reproductive tract to modulate immune responses, promote implantation, and support early embryonic development.

Examples of seminal plasma proteins include prostate-specific antigen (PSA), prostate-specific acid phosphatase (PSAP), and semenogelins. Abnormal levels or dysfunctions in these proteins have been associated with various reproductive disorders, such as infertility, prostatitis, and prostate cancer.

Pollen, in a medical context, refers to the fine powder-like substance produced by the male reproductive organ of seed plants. It contains microscopic grains known as pollen grains, which are transported by various means such as wind, water, or insects to the female reproductive organ of the same or another plant species for fertilization.

Pollen can cause allergic reactions in some individuals, particularly during the spring and summer months when plants release large amounts of pollen into the air. These allergies, also known as hay fever or seasonal allergic rhinitis, can result in symptoms such as sneezing, runny nose, congestion, itchy eyes, and coughing.

It is important to note that while all pollen has the potential to cause allergic reactions, certain types of plants, such as ragweed, grasses, and trees, are more likely to trigger symptoms in sensitive individuals.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Sperm maturation is the process by which spermatids, immature sperm cells produced in meiosis, transform into fully developed spermatozoa capable of fertilization. This complex process occurs in the seminiferous tubules of the testes and includes several stages:

1. **Golfi formation:** The first step involves the spermatids reorganizing their cytoplasm and forming a cap-like structure called the acrosome, which contains enzymes that help the sperm penetrate the egg's outer layers during fertilization.
2. **Flagellum development:** The spermatid also develops a tail (flagellum), enabling it to move independently. This is achieved through the assembly of microtubules and other associated proteins.
3. **Nuclear condensation and elongation:** The sperm's DNA undergoes significant compaction, making the nucleus smaller and more compact. Concurrently, the nucleus elongates and aligns with the flagellum.
4. **Mitochondrial positioning:** Mitochondria, which provide energy for sperm motility, migrate to the midpiece of the sperm, close to the base of the flagellum.
5. **Chromatin packaging:** Histones, proteins that help package DNA in non-sperm cells, are replaced by transition proteins and then protamines, which further compact and protect the sperm's DNA.
6. **Sperm release (spermiation):** The mature sperm is finally released from the supporting Sertoli cells into the lumen of the seminiferous tubule, where it mixes with fluid secreted by the testicular tissue to form seminal plasma.

This entire process takes approximately 64 days in humans.

'Bufo arenarum' is the scientific name for a species of toad that is native to Argentina. This toad, also known as the Argentine Toad or the Sand Toad, produces a toxic secretion from its skin as a defense against predators. The toxicity of this secretion can be harmful or even fatal if ingested or absorbed through the mucous membranes, making handling this toad with care important.

The medical definition of 'Bufo arenarum' would typically refer to the physical characteristics and behaviors of this species, as well as any potential medical implications of its toxic secretions. It is worth noting that some people have used the dried secretion of this toad, known as "toad licks" or "toad venom," as a recreational drug, despite the significant health risks associated with its use. This practice is strongly discouraged due to the potential for serious harm or even death.

In medical terms, "seeds" are often referred to as a small amount of a substance, such as a radioactive material or drug, that is inserted into a tissue or placed inside a capsule for the purpose of treating a medical condition. This can include procedures like brachytherapy, where seeds containing radioactive materials are used in the treatment of cancer to kill cancer cells and shrink tumors. Similarly, in some forms of drug delivery, seeds containing medication can be used to gradually release the drug into the body over an extended period of time.

It's important to note that "seeds" have different meanings and applications depending on the medical context. In other cases, "seeds" may simply refer to small particles or structures found in the body, such as those present in the eye's retina.

Spontaneous abortion, also known as miscarriage, is the unintentional expulsion of a nonviable fetus from the uterus before the 20th week of gestation. It is a common complication of early pregnancy, with most miscarriages occurring during the first trimester. Spontaneous abortion can have various causes, including chromosomal abnormalities, maternal health conditions, infections, hormonal imbalances, and structural issues of the uterus or cervix. In many cases, the exact cause may remain unknown.

The symptoms of spontaneous abortion can vary but often include vaginal bleeding, which may range from light spotting to heavy bleeding; abdominal pain or cramping; and the passing of tissue or clots from the vagina. While some miscarriages occur suddenly and are immediately noticeable, others may progress slowly over several days or even weeks.

In medical practice, healthcare providers often use specific terminology to describe different stages and types of spontaneous abortion. For example:

* Threatened abortion: Vaginal bleeding during early pregnancy, but the cervix remains closed, and there is no evidence of fetal demise or passing of tissue.
* Inevitable abortion: Vaginal bleeding with an open cervix, indicating that a miscarriage is imminent or already in progress.
* Incomplete abortion: The expulsion of some but not all products of conception from the uterus, requiring medical intervention to remove any remaining tissue.
* Complete abortion: The successful passage of all products of conception from the uterus, often confirmed through an ultrasound or pelvic examination.
* Missed abortion: The death of a fetus in the uterus without any expulsion of the products of conception, which may be discovered during routine prenatal care.
* Septic abortion: A rare and life-threatening complication of spontaneous abortion characterized by infection of the products of conception and the surrounding tissues, requiring prompt medical attention and antibiotic treatment.

Healthcare providers typically monitor patients who experience a spontaneous abortion to ensure that all products of conception have been expelled and that there are no complications, such as infection or excessive bleeding. In some cases, medication or surgical intervention may be necessary to remove any remaining tissue or address other issues related to the miscarriage. Counseling and support services are often available for individuals and couples who experience a spontaneous abortion, as they may face emotional challenges and concerns about future pregnancies.

Semen analysis is a laboratory test that evaluates various characteristics of semen, the fluid that is released during ejaculation. These characteristics include:

1. Volume: The amount of semen produced in one ejaculation.
2. Liquefaction time: The time it takes for the semen to change from a gel-like consistency to a liquid state.
3. pH: The acidity or alkalinity of the semen.
4. Sperm concentration: The number of sperm present in each milliliter of semen.
5. Total sperm count: The total number of sperm in the entire ejaculate.
6. Motility: The percentage of sperm that are moving and their forward progression.
7. Morphology: The shape and size of the sperm.
8. Vitality: The percentage of live sperm in the sample.
9. White blood cell count: The presence of white blood cells, which can indicate an infection.

Semen analysis is often used to help diagnose male infertility, as well as to monitor the effectiveness of treatments for infertility. It may also be used to detect abnormalities in the reproductive system or to evaluate the effects of certain medications on sperm production and quality.

A surrogate mother is a woman who carries and gives birth to a child for another person or couple, called the intended parents. This can occur through traditional surrogacy, in which the surrogate mother is artificially inseminated with the intended father's sperm and she is genetically related to the child, or gestational surrogacy, in which the embryo created through in vitro fertilization (IVF) using the eggs and sperm of the intended parents or donors is transferred to the surrogate mother's uterus. Surrogacy arrangements are complex and involve legal, ethical, and emotional considerations. It is important for all parties involved to have a clear understanding of the process and to work with experienced professionals in order to ensure a successful outcome.

A morula is a term used in embryology, which refers to the early stage of development in mammalian embryos. It is formed after fertilization when the zygote (a single cell resulting from the fusion of sperm and egg) undergoes several rounds of mitotic divisions to form a solid mass of 16 or more cells called blastomeres. At this stage, the cells are tightly packed together and have a compact, mulberry-like appearance, hence the name "morula" which is derived from the Latin word for "mulberry."

The morula stage typically occurs about 4-5 days after fertilization in humans and is marked by the beginning of blastulation, where the cells start to differentiate and become organized into an outer layer (trophoblast) and an inner cell mass. The trophoblast will eventually form the placenta, while the inner cell mass will give rise to the embryo proper.

It's important to note that the morula stage is a transient phase in embryonic development, and it represents a critical period of growth and differentiation as the embryo prepares for implantation into the uterine wall.

Gonadotropins are hormones that stimulate the gonads (sex glands) to produce sex steroids and gametes (sex cells). In humans, there are two main types of gonadotropins: follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are produced and released by the anterior pituitary gland.

FSH plays a crucial role in the development and maturation of ovarian follicles in females and sperm production in males. LH triggers ovulation in females, causing the release of a mature egg from the ovary, and stimulates testosterone production in males.

Gonadotropins are often used in medical treatments to stimulate the gonads, such as in infertility therapies where FSH and LH are administered to induce ovulation or increase sperm production.

Sperm retrieval is a medical procedure that involves obtaining sperm from a male patient, usually for the purpose of assisted reproduction. This can be indicated in cases where the man has obstructive or non-obstructive azoospermia (absence of sperm in the semen), ejaculatory dysfunction, or other conditions that prevent the successful collection of sperm through conventional means, such as masturbation.

There are several methods for sperm retrieval, including:

1. Testicular sperm aspiration (TESA): A procedure where a fine needle is inserted into the testicle to aspirate (or draw out) sperm.
2. Percutaneous epididymal sperm aspiration (PESA): Similar to TESA, but the needle is inserted into the epididymis, a small structure that stores and transports sperm from the testicle.
3. Microsurgical epididymal sperm aspiration (MESA): A more invasive procedure where an incision is made in the scrotum to directly visualize the epididymis with a surgical microscope, allowing for the careful removal of sperm.
4. Testicular sperm extraction (TESE): Involves making a small incision in the testicle and removing a piece of tissue containing sperm-producing tubules. The tissue is then processed to extract viable sperm.
5. Microdissection testicular sperm extraction (microTESE): A refined version of TESE, where a surgical microscope is used to identify and isolate individual seminiferous tubules containing sperm in men with non-obstructive azoospermia.

The retrieved sperm can then be used for various assisted reproductive techniques, such as intracytoplasmic sperm injection (ICSI), where a single sperm is injected directly into an egg to facilitate fertilization.

In medical terms, suction refers to the process of creating and maintaining a partial vacuum in order to remove fluids or gases from a body cavity or wound. This is typically accomplished using specialized medical equipment such as a suction machine, which uses a pump to create the vacuum, and a variety of different suction tips or catheters that can be inserted into the area being treated.

Suction is used in a wide range of medical procedures and treatments, including wound care, surgical procedures, respiratory therapy, and diagnostic tests. It can help to remove excess fluids such as blood or pus from a wound, clear secretions from the airways during mechanical ventilation, or provide a means of visualizing internal structures during endoscopic procedures.

It is important to use proper technique when performing suctioning, as excessive or improperly applied suction can cause tissue damage or bleeding. Medical professionals are trained in the safe and effective use of suction equipment and techniques to minimize risks and ensure optimal patient outcomes.

Sexual behavior in animals refers to a variety of behaviors related to reproduction and mating that occur between members of the same species. These behaviors can include courtship displays, mating rituals, and various physical acts. The specific forms of sexual behavior displayed by a given species are influenced by a combination of genetic, hormonal, and environmental factors.

In some animals, sexual behavior is closely tied to reproductive cycles and may only occur during certain times of the year or under specific conditions. In other species, sexual behavior may be more frequent and less closely tied to reproduction, serving instead as a means of social bonding or communication.

It's important to note that while humans are animals, the term "sexual behavior" is often used in a more specific sense to refer to sexual activities between human beings. The study of sexual behavior in animals is an important area of research within the field of animal behavior and can provide insights into the evolutionary origins of human sexual behavior as well as the underlying mechanisms that drive it.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

Spermatogenesis is the process by which sperm cells, or spermatozoa, are produced in male organisms. It occurs in the seminiferous tubules of the testes and involves several stages:

1. Spermatocytogenesis: This is the initial stage where diploid spermatogonial stem cells divide mitotically to produce more spermatogonia, some of which will differentiate into primary spermatocytes.
2. Meiosis: The primary spermatocytes undergo meiotic division to form haploid secondary spermatocytes, which then divide again to form haploid spermatids. This process results in the reduction of chromosome number from 46 (diploid) to 23 (haploid).
3. Spermiogenesis: The spermatids differentiate into spermatozoa, undergoing morphological changes such as the formation of a head and tail. During this stage, most of the cytoplasm is discarded, resulting in highly compacted and streamlined sperm cells.
4. Spermation: The final stage where mature sperm are released from the seminiferous tubules into the epididymis for further maturation and storage.

The entire process takes approximately 72-74 days in humans, with continuous production throughout adulthood.

A zebrafish is a freshwater fish species belonging to the family Cyprinidae and the genus Danio. Its name is derived from its distinctive striped pattern that resembles a zebra's. Zebrafish are often used as model organisms in scientific research, particularly in developmental biology, genetics, and toxicology studies. They have a high fecundity rate, transparent embryos, and a rapid development process, making them an ideal choice for researchers. However, it is important to note that providing a medical definition for zebrafish may not be entirely accurate or relevant since they are primarily used in biological research rather than clinical medicine.

Buserelin is a synthetic analogue of gonadotropin-releasing hormone (GnRH or LHRH), which is a hormonal drug used in the treatment of various conditions such as endometriosis, uterine fibroids, prostate cancer, and central precocious puberty.

By mimicking the action of natural GnRH, buserelin stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland, which in turn regulates the production of sex hormones such as estrogen and testosterone.

However, prolonged use of buserelin leads to downregulation of GnRH receptors and a decrease in FSH and LH secretion, resulting in reduced levels of sex hormones. This property is exploited in the treatment of hormone-dependent cancers such as prostate cancer, where reducing testosterone levels can help slow tumor growth.

Buserelin is available in various forms, including nasal sprays, implants, and injectable solutions, and its use should be under the supervision of a healthcare professional due to potential side effects and the need for careful monitoring of hormone levels during treatment.

Culture media is a substance that is used to support the growth of microorganisms or cells in an artificial environment, such as a petri dish or test tube. It typically contains nutrients and other factors that are necessary for the growth and survival of the organisms being cultured. There are many different types of culture media, each with its own specific formulation and intended use. Some common examples include blood agar, which is used to culture bacteria; Sabouraud dextrose agar, which is used to culture fungi; and Eagle's minimum essential medium, which is used to culture animal cells.

Nitrogen is not typically referred to as a medical term, but it is an element that is crucial to medicine and human life.

In a medical context, nitrogen is often mentioned in relation to gas analysis, respiratory therapy, or medical gases. Nitrogen (N) is a colorless, odorless, and nonreactive gas that makes up about 78% of the Earth's atmosphere. It is an essential element for various biological processes, such as the growth and maintenance of organisms, because it is a key component of amino acids, nucleic acids, and other organic compounds.

In some medical applications, nitrogen is used to displace oxygen in a mixture to create a controlled environment with reduced oxygen levels (hypoxic conditions) for therapeutic purposes, such as in certain types of hyperbaric chambers. Additionally, nitrogen gas is sometimes used in cryotherapy, where extremely low temperatures are applied to tissues to reduce pain, swelling, and inflammation.

However, it's important to note that breathing pure nitrogen can be dangerous, as it can lead to unconsciousness and even death due to lack of oxygen (asphyxiation) within minutes.

Fetal viability is the point in pregnancy at which a fetus is considered capable of surviving outside the uterus, given appropriate medical support. Although there is no precise gestational age that defines fetal viability, it is generally considered to occur between 24 and 28 weeks of gestation. At this stage, the fetus has developed sufficient lung maturity and body weight, and the risk of neonatal mortality and morbidity significantly decreases. However, the exact definition of fetal viability may vary depending on regional standards, medical facilities, and individual clinical assessments.

Vitrification is a process used in cryopreservation, where a liquid or semi-liquid biological material is transformed into a glass-like solid state by cooling it to extremely low temperatures at a rate that suppresses the formation of ice crystals. This technique is often used in assisted reproductive technology (ART) for preserving oocytes (human eggs), embryos, and ovarian or testicular tissues.

During vitrification, the biological material is exposed to high concentrations of cryoprotectants, which help prevent ice crystal formation and minimize cellular damage during cooling. The sample is then rapidly cooled using liquid nitrogen, achieving temperatures below -150°C (-238°F) in a matter of seconds or minutes.

The primary advantage of vitrification over traditional slow-freezing methods is the elimination of ice crystal formation, which can cause significant damage to cellular structures and organelles. Vitrified samples maintain their structural integrity and have higher survival rates upon thawing, making them more suitable for use in ART procedures.

However, it's important to note that vitrification also has potential risks, such as the toxicity of high cryoprotectant concentrations and the possibility of cracking during cooling or warming due to thermal stress. Proper technique and careful handling are crucial to ensure successful vitrification and subsequent use in clinical applications.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

Ionophores are compounds that have the ability to form complexes with ions and facilitate their transportation across biological membranes. They can be either organic or inorganic molecules, and they play important roles in various physiological processes, including ion homeostasis, signal transduction, and antibiotic activity. In medicine and research, ionophores are used as tools to study ion transport, modulate cellular functions, and as therapeutic agents, especially in the treatment of bacterial and fungal infections.

Gonadotropin-Releasing Hormone (GnRH), also known as Luteinizing Hormone-Releasing Hormone (LHRH), is a hormonal peptide consisting of 10 amino acids. It is produced and released by the hypothalamus, an area in the brain that links the nervous system to the endocrine system via the pituitary gland.

GnRH plays a crucial role in regulating reproduction and sexual development through its control of two gonadotropins: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These gonadotropins, in turn, stimulate the gonads (ovaries or testes) to produce sex steroids and eggs or sperm.

GnRH acts on the anterior pituitary gland by binding to its specific receptors, leading to the release of FSH and LH. The hypothalamic-pituitary-gonadal axis is under negative feedback control, meaning that when sex steroid levels are high, they inhibit the release of GnRH, which subsequently decreases FSH and LH secretion.

GnRH agonists and antagonists have clinical applications in various medical conditions, such as infertility treatments, precocious puberty, endometriosis, uterine fibroids, prostate cancer, and hormone-responsive breast cancer.

Estradiol is a type of estrogen, which is a female sex hormone. It is the most potent and dominant form of estrogen in humans. Estradiol plays a crucial role in the development and maintenance of secondary sexual characteristics in women, such as breast development and regulation of the menstrual cycle. It also helps maintain bone density, protect the lining of the uterus, and is involved in cognition and mood regulation.

Estradiol is produced primarily by the ovaries, but it can also be synthesized in smaller amounts by the adrenal glands and fat cells. In men, estradiol is produced from testosterone through a process called aromatization. Abnormal levels of estradiol can contribute to various health issues, such as hormonal imbalances, infertility, osteoporosis, and certain types of cancer.

Protamines are small, arginine-rich proteins that are found in the sperm cells of many organisms. They play a crucial role in the process of sperm maturation, also known as spermiogenesis. During this process, the DNA in the sperm cell is tightly packed and compacted by the protamines, which helps to protect the genetic material during its journey to fertilize an egg.

Protamines are typically composed of around 50-100 amino acids and have a high proportion of positively charged arginine residues, which allow them to interact strongly with the negatively charged DNA molecule. This interaction results in the formation of highly condensed chromatin structures that are resistant to enzymatic digestion and other forms of damage.

In addition to their role in sperm maturation, protamines have also been studied for their potential use in drug delivery and gene therapy applications. Their ability to bind strongly to DNA makes them attractive candidates for delivering drugs or genetic material directly to the nucleus of a cell. However, more research is needed to fully understand the potential benefits and risks associated with these applications.

Oviducts, also known as fallopian tubes in humans, are pair of slender tubular structures that serve as the conduit for the ovum (egg) from the ovaries to the uterus. They are an essential part of the female reproductive system, providing a site for fertilization of the egg by sperm and early embryonic development before the embryo moves into the uterus for further growth.

In medical terminology, the term "oviduct" refers to this functional description rather than a specific anatomical structure in all female organisms. The oviducts vary in length and shape across different species, but their primary role remains consistent: to facilitate the transport of the egg and provide a site for fertilization.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Calcium signaling is the process by which cells regulate various functions through changes in intracellular calcium ion concentrations. Calcium ions (Ca^2+^) are crucial second messengers that play a critical role in many cellular processes, including muscle contraction, neurotransmitter release, gene expression, and programmed cell death (apoptosis).

Intracellular calcium levels are tightly regulated by a complex network of channels, pumps, and exchangers located on the plasma membrane and intracellular organelles such as the endoplasmic reticulum (ER) and mitochondria. These proteins control the influx, efflux, and storage of calcium ions within the cell.

Calcium signaling is initiated when an external signal, such as a hormone or neurotransmitter, binds to a specific receptor on the plasma membrane. This interaction triggers the opening of ion channels, allowing extracellular Ca^2+^ to flow into the cytoplasm. In some cases, this influx of calcium ions is sufficient to activate downstream targets directly. However, in most instances, the increase in intracellular Ca^2+^ serves as a trigger for the release of additional calcium from internal stores, such as the ER.

The release of calcium from the ER is mediated by ryanodine receptors (RyRs) and inositol trisphosphate receptors (IP3Rs), which are activated by specific second messengers generated in response to the initial external signal. The activation of these channels leads to a rapid increase in cytoplasmic Ca^2+^, creating a transient intracellular calcium signal known as a "calcium spark" or "calcium puff."

These localized increases in calcium concentration can then propagate throughout the cell as waves of elevated calcium, allowing for the spatial and temporal coordination of various cellular responses. The duration and amplitude of these calcium signals are finely tuned by the interplay between calcium-binding proteins, pumps, and exchangers, ensuring that appropriate responses are elicited in a controlled manner.

Dysregulation of intracellular calcium signaling has been implicated in numerous pathological conditions, including neurodegenerative diseases, cardiovascular disorders, and cancer. Therefore, understanding the molecular mechanisms governing calcium homeostasis and signaling is crucial for the development of novel therapeutic strategies targeting these diseases.

Progesterone is a steroid hormone that is primarily produced in the ovaries during the menstrual cycle and in pregnancy. It plays an essential role in preparing the uterus for implantation of a fertilized egg and maintaining the early stages of pregnancy. Progesterone works to thicken the lining of the uterus, creating a nurturing environment for the developing embryo.

During the menstrual cycle, progesterone is produced by the corpus luteum, a temporary structure formed in the ovary after an egg has been released from a follicle during ovulation. If pregnancy does not occur, the levels of progesterone will decrease, leading to the shedding of the uterine lining and menstruation.

In addition to its reproductive functions, progesterone also has various other effects on the body, such as helping to regulate the immune system, supporting bone health, and potentially influencing mood and cognition. Progesterone can be administered medically in the form of oral pills, intramuscular injections, or vaginal suppositories for various purposes, including hormone replacement therapy, contraception, and managing certain gynecological conditions.

Developmental gene expression regulation refers to the processes that control the activation or repression of specific genes during embryonic and fetal development. These regulatory mechanisms ensure that genes are expressed at the right time, in the right cells, and at appropriate levels to guide proper growth, differentiation, and morphogenesis of an organism.

Developmental gene expression regulation is a complex and dynamic process involving various molecular players, such as transcription factors, chromatin modifiers, non-coding RNAs, and signaling molecules. These regulators can interact with cis-regulatory elements, like enhancers and promoters, to fine-tune the spatiotemporal patterns of gene expression during development.

Dysregulation of developmental gene expression can lead to various congenital disorders and developmental abnormalities. Therefore, understanding the principles and mechanisms governing developmental gene expression regulation is crucial for uncovering the etiology of developmental diseases and devising potential therapeutic strategies.

Gamete Intrafallopian Transfer (GIFT) is a type of assisted reproductive technology (ART) that involves the transfer of both sperm and eggs directly into a woman's fallopian tubes through a surgical procedure. This process allows for fertilization to occur naturally within the woman's body, increasing the chances of successful implantation and pregnancy.

In GIFT, mature eggs are collected from the woman's ovaries through a minor surgical procedure called follicular aspiration. These eggs are then mixed with prepared sperm from the partner or a donor in the laboratory. The mixture of eggs and sperm is then transferred into the fallopian tubes using a thin catheter, which is inserted through a small incision made in the woman's abdomen.

GIFT is typically recommended for couples who have unexplained infertility or mild to moderate male factor infertility and for whom other fertility treatments, such as intrauterine insemination (IUI), have been unsuccessful. However, due to the invasive nature of the procedure and the need for general anesthesia, GIFT is less commonly used than other ART procedures, such as in vitro fertilization (IVF).

"Lytechinus" is not a medical term. It is the genus name for several species of sea urchins, which are marine animals with a hard, spiny shell and a mouth on the underside. They belong to the family Toxopneustidae and can be found in various parts of the world's oceans.

If you have any questions about marine biology or a different topic, please let me know!

Gametogenesis is the biological process by which haploid gametes, or sex cells (sperm and egg cells), are produced through the meiotic division of diploid germ cells. In females, this process is called oogenesis, where an oogonium (diploid germ cell) undergoes mitosis to form an oocyte (immature egg cell). The oocyte then undergoes meiosis I to form a secondary oocyte and a polar body. After fertilization by a sperm cell, the secondary oocyte completes meiosis II to form a mature ovum or egg cell.

In males, this process is called spermatogenesis, where a spermatogonium (diploid germ cell) undergoes mitosis to form primary spermatocytes. Each primary spermatocyte then undergoes meiosis I to form two secondary spermatocytes, which subsequently undergo meiosis II to form four haploid spermatids. The spermatids then differentiate into spermatozoa or sperm cells through a process called spermiogenesis.

Gametogenesis is essential for sexual reproduction and genetic diversity, as it involves the random segregation of chromosomes during meiosis and the recombination of genetic material between homologous chromosomes.

Nafarelin is a synthetic decapeptide analog of the natural gonadotropin-releasing hormone (GnRH). It is primarily used as a nasal spray for the treatment of central precocious puberty in children and endometriosis in adults.

In medical terms, Nafarelin is defined as:

A synthetic decapeptide analog of gonadotropin-releasing hormone (GnRH) used in the treatment of central precocious puberty and endometriosis. It acts as a potent agonist of GnRH receptors, leading to an initial increase in the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), followed by downregulation of these receptors and a decrease in FSH and LH secretion. This results in decreased gonadal steroid production, including estrogen and testosterone, which helps to control the symptoms of central precocious puberty and endometriosis.

Nafarelin is available under the brand name Synarel and is administered as a nasal spray. It is important to note that Nafarelin can cause side effects such as hot flashes, headaches, and mood changes, and it may also affect bone growth in children with central precocious puberty. Therefore, it should be used under the close supervision of a healthcare provider.

Germ cells are the reproductive cells, also known as sex cells, that combine to form offspring in sexual reproduction. In females, germ cells are called ova or egg cells, and in males, they are called spermatozoa or sperm cells. These cells are unique because they carry half the genetic material necessary for creating new life. They are produced through a process called meiosis, which reduces their chromosome number by half, ensuring that when two germ cells combine during fertilization, the normal diploid number of chromosomes is restored.

I'm sorry for any confusion, but "Hyaluronoglucosaminidase" appears to be a made-up term or a typographical error. The correct term related to hyaluronic acid metabolism is "hyaluronidase," which is an enzyme that degrades hyaluronic acid, a component of the extracellular matrix in various tissues. If you meant to ask about this enzyme or its functions, I'd be happy to provide more information on that. However, if "Hyaluronoglucosaminidase" is intended to represent another medical term, could you please clarify so I can provide an accurate and helpful response?

Inbred strains of mice are defined as lines of mice that have been brother-sister mated for at least 20 consecutive generations. This results in a high degree of homozygosity, where the mice of an inbred strain are genetically identical to one another, with the exception of spontaneous mutations.

Inbred strains of mice are widely used in biomedical research due to their genetic uniformity and stability, which makes them useful for studying the genetic basis of various traits, diseases, and biological processes. They also provide a consistent and reproducible experimental system, as compared to outbred or genetically heterogeneous populations.

Some commonly used inbred strains of mice include C57BL/6J, BALB/cByJ, DBA/2J, and 129SvEv. Each strain has its own unique genetic background and phenotypic characteristics, which can influence the results of experiments. Therefore, it is important to choose the appropriate inbred strain for a given research question.

Maternal age is a term used to describe the age of a woman at the time she becomes pregnant or gives birth. It is often used in medical and epidemiological contexts to discuss the potential risks, complications, and outcomes associated with pregnancy and childbirth at different stages of a woman's reproductive years.

Advanced maternal age typically refers to women who become pregnant or give birth at 35 years of age or older. This group faces an increased risk for certain chromosomal abnormalities, such as Down syndrome, and other pregnancy-related complications, including gestational diabetes, preeclampsia, and cesarean delivery.

On the other end of the spectrum, adolescent pregnancies (those that occur in women under 20 years old) also come with their own set of potential risks and complications, such as preterm birth, low birth weight, and anemia.

It's important to note that while maternal age can influence pregnancy outcomes, many other factors – including genetics, lifestyle choices, and access to quality healthcare – can also play a significant role in determining the health of both mother and baby during pregnancy and childbirth.

Preimplantation Diagnosis (PID) is a genetic testing procedure performed on embryos created through in vitro fertilization (IVF), before they are implanted in the uterus. The purpose of PID is to identify genetic disorders or chromosomal abnormalities in the embryos, allowing only those free of such issues to be transferred to the uterus, thereby reducing the risk of passing on genetic diseases to offspring. It involves biopsying one or more cells from an embryo and analyzing its DNA for specific genetic disorders or chromosomal abnormalities. PID is often recommended for couples with a known history of genetic disorders or those who have experienced multiple miscarriages or failed IVF cycles.

Annelida is a phylum of bilaterally symmetrical, segmented animals that includes earthworms, leeches, and marine polychaetes (bristle worms). The name "Annelida" comes from the Latin word "annellus," meaning "little ring," which refers to the distinct segments found in these animals.

Each segment in annelids contains a pair of bundled nerves called the ventral nerve cord, and many also contain circular and longitudinal muscles that enable the animal to move by contracting and relaxing these muscles in a wave-like motion. Some annelids have specialized segments for functions such as reproduction or respiration.

Annelids are primarily aquatic animals, although some terrestrial species like earthworms have evolved to live on land. They vary in size from tiny marine worms that are only a few millimeters long to large marine polychaetes that can reach over a meter in length.

Annelids are important decomposers and help break down dead organic matter, returning nutrients to the soil or water. Some species of annelids are also parasitic, feeding on the blood or tissues of other animals. Overall, annelids play a crucial role in many aquatic and terrestrial ecosystems.

ICR (Institute of Cancer Research) is a strain of albino Swiss mice that are widely used in scientific research. They are an outbred strain, which means that they have been bred to maintain maximum genetic heterogeneity. However, it is also possible to find inbred strains of ICR mice, which are genetically identical individuals produced by many generations of brother-sister mating.

Inbred ICR mice are a specific type of ICR mouse that has been inbred for at least 20 generations. This means that they have a high degree of genetic uniformity and are essentially genetically identical to one another. Inbred strains of mice are often used in research because their genetic consistency makes them more reliable models for studying biological phenomena and testing new therapies or treatments.

It is important to note that while inbred ICR mice may be useful for certain types of research, they do not necessarily represent the genetic diversity found in human populations. Therefore, it is important to consider the limitations of using any animal model when interpreting research findings and applying them to human health.

Equine Gonadotropins are glycoprotein hormones derived from the pituitary gland of horses. They consist of two subunits: a common alpha subunit and a unique beta subunit that determines the biological activity of each hormone. There are two main types of equine gonadotropins: Equine Follicle Stimulating Hormone (eFSH) and Equine Luteinizing Hormone (eLH).

eFSH plays a crucial role in the growth and development of ovarian follicles in females, while eLH stimulates ovulation and the production of sex steroids in both males and females. These hormones are often used in veterinary medicine to induce ovulation and improve fertility in horses, as well as in research to study the physiology and biochemistry of gonadotropins and reproduction. It's important to note that equine gonadotropins have limited application in human reproductive medicine due to potential immunogenic reactions and other safety concerns.

Chromomycin A3 is an antibiotic and a DNA-binding molecule that is used in research and scientific studies. It is a type of glycosylated anthracycline that can intercalate into DNA and inhibit DNA-dependent RNA synthesis. Chromomycin A3 has been used as a fluorescent stain for microscopy, particularly for the staining of chromosomes during mitosis. It is also used in molecular biology research to study the interactions between drugs and DNA.

It's important to note that Chromomycin A3 is not used as a therapeutic drug in human or veterinary medicine due to its toxicity, it's mainly used for research purposes.

Endosperm is a type of tissue found in the seeds of flowering plants, which provides nutrition to the developing embryo. It is formed from the fusion of one sperm cell with two polar nuclei during double fertilization in angiosperms (flowering plants). The endosperm can be triploid (having three sets of chromosomes) or sometimes diploid (having two sets of chromosomes), depending on the species.

The endosperm can have different forms and functions across various plant species. In some seeds, it serves as a food storage tissue, accumulating starch, proteins, and lipids that are used up by the embryo during germination and early growth. Examples of such seeds include cereal grains like corn, wheat, rice, and barley, where the endosperm makes up a significant portion of the grain.

In other plants, the endosperm may be absorbed by the developing embryo before seed maturation, leaving only a thin layer called the aleurone layer that surrounds the embryo. This aleurone layer is responsible for producing enzymes during germination, which help in breaking down stored nutrients and making them available to the growing embryo.

Overall, endosperm plays a crucial role in the development and survival of angiosperm seeds, acting as a source of nutrition and energy for the embryo.

Phaeophyta is a taxonomic division that refers to a group of complex, multicellular brown algae found in marine environments. These algae are characterized by their pigmentation, which includes fucoxanthin, chlorophyll-a, and chlorophyll-c, giving them a brown color. They have diverse morphology, ranging from simple thread-like forms to large seaweeds.

Phaeophyta species are primarily found in cold, nutrient-rich waters and play an essential role in marine ecosystems as primary producers and habitats for various marine organisms. Some examples of Phaeophyta include kelps, rockweed, and bladderwrack. It's worth noting that the classification and nomenclature of algae are continually evolving, so different sources might use slightly different terminology or categorization.

Confocal microscopy is a powerful imaging technique used in medical and biological research to obtain high-resolution, contrast-rich images of thick samples. This super-resolution technology provides detailed visualization of cellular structures and processes at various depths within a specimen.

In confocal microscopy, a laser beam focused through a pinhole illuminates a small spot within the sample. The emitted fluorescence or reflected light from this spot is then collected by a detector, passing through a second pinhole that ensures only light from the focal plane reaches the detector. This process eliminates out-of-focus light, resulting in sharp images with improved contrast compared to conventional widefield microscopy.

By scanning the laser beam across the sample in a raster pattern and collecting fluorescence at each point, confocal microscopy generates optical sections of the specimen. These sections can be combined to create three-dimensional reconstructions, allowing researchers to study cellular architecture and interactions within complex tissues.

Confocal microscopy has numerous applications in medical research, including studying protein localization, tracking intracellular dynamics, analyzing cell morphology, and investigating disease mechanisms at the cellular level. Additionally, it is widely used in clinical settings for diagnostic purposes, such as analyzing skin lesions or detecting pathogens in patient samples.

I'm sorry for any confusion, but "human characteristics" is not a medical term or concept. It refers to the typical traits, attributes, and features that define humans as a species, both physically and behaviorally. Physical human characteristics include bipedal locomotion, large brains, and fine motor skills, while behavioral characteristics can include complex language use, self-awareness, and sociality.

However, if you have any specific medical or health-related questions, I would be happy to help answer them to the best of my ability!

I'm sorry for any confusion, but "flowers" is not a term that has a medical definition. The term "flowers" is commonly used to refer to the reproductive structures of flowering plants (angiosperms), which are characterized by having both male and female reproductive organs or separate male and female flowers.

If you have any questions related to medical terminology or health conditions, I would be happy to try to help answer those for you!

Azoospermia is a medical condition where there is no measurable level of sperm in the semen. This means that during ejaculation, the seminal fluid does not contain any sperm cells. Azoospermia can be caused by various factors including problems with testicular function, obstruction of the genital tract, or hormonal imbalances. It is an important cause of male infertility and may require further medical evaluation and treatment to determine the underlying cause and explore potential options for fertility.

There are two types of azoospermia: obstructive azoospermia and non-obstructive azoospermia. Obstructive azoospermia is caused by blockages or obstructions in the genital tract that prevent sperm from being released into the semen, while non-obstructive azoospermia is due to problems with sperm production in the testicles.

In some cases, men with azoospermia may still be able to father children through assisted reproductive technologies such as intracytoplasmic sperm injection (ICSI), where a single sperm is injected directly into an egg for fertilization. However, this will depend on the underlying cause of the azoospermia and whether or not there are viable sperm available for extraction.

Culture techniques are methods used in microbiology to grow and multiply microorganisms, such as bacteria, fungi, or viruses, in a controlled laboratory environment. These techniques allow for the isolation, identification, and study of specific microorganisms, which is essential for diagnostic purposes, research, and development of medical treatments.

The most common culture technique involves inoculating a sterile growth medium with a sample suspected to contain microorganisms. The growth medium can be solid or liquid and contains nutrients that support the growth of the microorganisms. Common solid growth media include agar plates, while liquid growth media are used for broth cultures.

Once inoculated, the growth medium is incubated at a temperature that favors the growth of the microorganisms being studied. During incubation, the microorganisms multiply and form visible colonies on the solid growth medium or turbid growth in the liquid growth medium. The size, shape, color, and other characteristics of the colonies can provide important clues about the identity of the microorganism.

Other culture techniques include selective and differential media, which are designed to inhibit the growth of certain types of microorganisms while promoting the growth of others, allowing for the isolation and identification of specific pathogens. Enrichment cultures involve adding specific nutrients or factors to a sample to promote the growth of a particular type of microorganism.

Overall, culture techniques are essential tools in microbiology and play a critical role in medical diagnostics, research, and public health.

The "beginning of human life" is a term that is often used in the context of medical ethics, particularly in discussions about issues such as abortion and stem cell research. However, there is no universally accepted medical definition of this term, as it is also influenced by philosophical, religious, and legal considerations.

From a biological perspective, human life begins at fertilization, when a sperm cell successfully penetrates and fuses with an egg cell to form a zygote. This single cell contains the complete genetic makeup of the future individual and has the potential to develop into a fully formed human being, given the right conditions.

However, some people argue that personhood or moral status does not begin until later stages of development, such as at implantation, when the zygote attaches to the uterine wall and begins to receive nutrients from the mother's body, or at viability, when the fetus can survive outside the womb with medical assistance.

Ultimately, the definition of "beginning of human life" is a complex and controversial issue that depends on one's values and beliefs. It is important to recognize and respect the diversity of opinions on this matter and engage in thoughtful and respectful dialogue about its implications for medical practice and policy.

Follicle-Stimulating Hormone (FSH) is a glycoprotein hormone secreted by the anterior pituitary gland. In humans, FSH plays a crucial role in the reproductive system. Specifically, in females, it stimulates the growth of ovarian follicles in the ovary and the production of estrogen. In males, FSH promotes the formation of sperm within the testes' seminiferous tubules. The human FSH is a heterodimer, consisting of two noncovalently associated subunits: α (alpha) and β (beta). The alpha subunit is common to several pituitary hormones, including thyroid-stimulating hormone (TSH), luteinizing hormone (LH), and human chorionic gonadotropin (hCG). In contrast, the beta subunit is unique to FSH and determines its biological specificity. The regulation of FSH secretion is primarily controlled by the hypothalamic-pituitary axis, involving complex feedback mechanisms with gonadal steroid hormones and inhibins.

Defining "life" is a complex question that has been debated by philosophers, scientists, and theologians for centuries. From a biological or medical perspective, life can be defined as a characteristic that distinguishes physical entities that do have biological processes, such as growth, reproduction, and response to stimuli, from those that do not, either because such functions have ceased (death), or because they never had such functions and are classified as inanimate.

The National Institutes of Health (NIH) defines life as "the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death."

It's important to note that there is no one universally accepted definition of life, and different fields and disciplines may have slightly different definitions or criteria.

In the field of medicine, twins are defined as two offspring produced by the same pregnancy. They can be either monozygotic (identical) or dizygotic (fraternal). Monozygotic twins develop from a single fertilized egg that splits into two separate embryos, resulting in individuals who share identical genetic material. Dizygotic twins, on the other hand, result from the fertilization of two separate eggs by two different sperm cells, leading to siblings who share about 50% of their genetic material, similar to non-twin siblings.

Zygote Intrafallopian Transfer (ZIFT) is a type of assisted reproductive technology (ART) that involves the transfer of a fertilized egg, or zygote, into the fallopian tube. The procedure is typically used to help individuals or couples who have difficulty conceiving naturally.

The ZIFT process begins with the retrieval of eggs from the ovaries through a minor surgical procedure called follicular aspiration. These eggs are then fertilized in a laboratory with sperm from the partner or a donor. The resulting zygotes are allowed to grow for about 24 hours, at which point they have typically divided into two cells.

The next step is to transfer the zygotes into the fallopian tubes using a thin catheter. This procedure is usually performed under sedation or anesthesia and takes only a few minutes. The goal of ZIFT is to place the zygotes in the optimal location for implantation and pregnancy to occur.

ZIFT has a slightly higher success rate than other forms of ART, such as in vitro fertilization (IVF), because it places the embryos closer to the site of implantation. However, ZIFT also carries a higher risk of complications, including ectopic pregnancy and infection.

It's important to note that ZIFT is not a common procedure due to the complexity of the process and the availability of other less invasive options like IVF. The decision to undergo ZIFT should be made in consultation with a fertility specialist and based on individual circumstances and medical history.

"Sex preselection," also known as "gender selection" or "family balancing," is the process of influencing the sex of an offspring before birth. It can be achieved through various methods, including preimplantation genetic diagnosis (PGD) in conjunction with in vitro fertilization (IVF), sperm sorting techniques, and embryo manipulation.

PGD is a technique where one or more cells are taken from an embryo created through IVF and tested for genetic disorders or chromosomal abnormalities. During this process, the sex of the embryo can also be determined. Only embryos of the desired sex are then transferred to the uterus for implantation.

Sperm sorting techniques involve separating X-chromosome-bearing sperm (which produce female offspring) from Y-chromosome-bearing sperm (which produce male offspring). The sorted sperm can then be used for artificial insemination or IVF.

It's important to note that sex preselection is a controversial topic due to ethical considerations and legal restrictions in some countries.

I'm sorry for any confusion, but "pollination" is not a term typically used in medical definitions. Pollination is a process in biology, specifically in botany, that refers to the transfer of pollen from the male reproductive organ (anther) of a flower to the female reproductive organ (stigma) of the same or another flower, leading to fertilization and the production of fruits and seeds.

If you have any medical terms or concepts in mind, please provide them so I can offer an accurate definition or explanation.

Membrane glycoproteins are proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. They are integral components of biological membranes, spanning the lipid bilayer and playing crucial roles in various cellular processes.

The glycosylation of these proteins occurs in the endoplasmic reticulum (ER) and Golgi apparatus during protein folding and trafficking. The attached glycans can vary in structure, length, and composition, which contributes to the diversity of membrane glycoproteins.

Membrane glycoproteins can be classified into two main types based on their orientation within the lipid bilayer:

1. Type I (N-linked): These glycoproteins have a single transmembrane domain and an extracellular N-terminus, where the oligosaccharides are predominantly attached via asparagine residues (Asn-X-Ser/Thr sequon).
2. Type II (C-linked): These glycoproteins possess two transmembrane domains and an intracellular C-terminus, with the oligosaccharides linked to tryptophan residues via a mannose moiety.

Membrane glycoproteins are involved in various cellular functions, such as:

* Cell adhesion and recognition
* Receptor-mediated signal transduction
* Enzymatic catalysis
* Transport of molecules across membranes
* Cell-cell communication
* Immunological responses

Some examples of membrane glycoproteins include cell surface receptors (e.g., growth factor receptors, cytokine receptors), adhesion molecules (e.g., integrins, cadherins), and transporters (e.g., ion channels, ABC transporters).

Ectopic pregnancy is a type of abnormal pregnancy that occurs outside the uterine cavity. The most common site for an ectopic pregnancy is the fallopian tube, accounting for about 95% of cases. This condition is also known as tubal pregnancy. Other less common sites include the ovary, cervix, and abdominal cavity.

In a normal pregnancy, the fertilized egg travels down the fallopian tube and implants itself in the lining of the uterus. However, in an ectopic pregnancy, the fertilized egg implants and starts to develop somewhere other than the uterus. The growing embryo cannot survive outside the uterus, and if left untreated, an ectopic pregnancy can cause life-threatening bleeding due to the rupture of the fallopian tube or other organs.

Symptoms of ectopic pregnancy may include abdominal pain, vaginal bleeding, shoulder pain, lightheadedness, fainting, and in severe cases, shock. Diagnosis is usually made through a combination of medical history, physical examination, ultrasound, and blood tests to measure the levels of human chorionic gonadotropin (hCG), a hormone produced during pregnancy.

Treatment for ectopic pregnancy depends on several factors, including the location, size, and growth rate of the ectopic mass, as well as the patient's overall health and desire for future pregnancies. Treatment options may include medication to stop the growth of the embryo or surgery to remove the ectopic tissue. In some cases, both methods may be used together. Early diagnosis and treatment can help prevent serious complications and improve the chances of preserving fertility in future pregnancies.

Leuprolide is a synthetic hormonal analog of gonadotropin-releasing hormone (GnRH or LHRH). It acts as a potent agonist of GnRH receptors, leading to the suppression of pituitary gland's secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This, in turn, results in decreased levels of sex hormones such as testosterone and estrogen.

Leuprolide is used clinically for the treatment of various conditions related to hormonal imbalances, including:
- Prostate cancer: Leuprolide can help slow down the growth of prostate cancer cells by reducing testosterone levels in the body.
- Endometriosis: By lowering estrogen levels, leuprolide can alleviate symptoms associated with endometriosis such as pelvic pain and menstrual irregularities.
- Central precocious puberty: Leuprolide is used to delay the onset of puberty in children who experience it prematurely by inhibiting the release of gonadotropins.
- Uterine fibroids: Lowering estrogen levels with leuprolide can help shrink uterine fibroids and reduce symptoms like heavy menstrual bleeding and pelvic pain.

Leuprolide is available in various formulations, such as injectable depots or implants, for long-term hormonal suppression. Common side effects include hot flashes, mood changes, and potential loss of bone density due to prolonged hormone suppression.

The follicular phase is a term used in reproductive endocrinology, which refers to the first part of the menstrual cycle. This phase begins on the first day of menstruation and lasts until ovulation. During this phase, several follicles in the ovaries begin to mature under the influence of follicle-stimulating hormone (FSH) released by the pituitary gland.

Typically, one follicle becomes dominant and continues to mature, while the others regress. The dominant follicle produces increasing amounts of estrogen, which causes the lining of the uterus to thicken in preparation for a possible pregnancy. The follicular phase can vary in length, but on average it lasts about 14 days.

It's important to note that the length and characteristics of the follicular phase can provide valuable information in diagnosing various reproductive disorders, such as polycystic ovary syndrome (PCOS) or thyroid dysfunction.

Proto-oncogene proteins c-mos are a type of serine/threonine protein kinase that play crucial roles in cell cycle regulation, particularly during the G2 phase and the transition to mitosis. The c-mos gene is a normal version of an oncogene, which can become cancer-causing when mutated or overexpressed. In its normal form, the c-mos protein is involved in controlling the progression of the cell cycle, meiosis, and also has been implicated in neuronal development and synaptic plasticity. Dysregulation of c-mos proto-oncogene proteins can contribute to tumorigenesis and cancer development.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Copulation is the act of sexual reproduction in animals, achieved through the process of mating and engaging in sexual intercourse. It involves the insertion of the male's reproductive organ (the penis) into the female's reproductive organ (vagina), followed by the ejaculation of semen, which contains sperm. The sperm then travels up through the cervix and into the uterus, where they may fertilize an egg or ovum that has been released from one of the ovaries.

In a broader sense, copulation can also refer to the act of reproduction in other organisms, such as plants, fungi, and protists, which may involve different processes such as pollination, fusion of gametes, or vegetative reproduction.

Ectogenesis is a theoretical concept in medical and reproductive biology that refers to the development of an organism outside of the body, typically referring to the growth and development of a fetus or embryo in an artificial environment, such as an external womb or an artificial uterus. This concept is still largely speculative and not currently possible with existing technology. It raises various ethical, legal, and social questions related to pregnancy, reproduction, and the nature of parenthood.

Sperm agglutination is the clumping or sticking together of sperm cells, which can be caused by the presence of antibodies or other substances in semen. In some cases, sperm agglutination may occur due to an immune response in which the body produces antibodies that attack and bind to sperm cells, leading to their clumping together. This can interfere with the sperm's ability to move and fertilize an egg.

Sperm agglutination can be detected through a semen analysis test, which involves examining a sample of semen under a microscope. If sperm agglutination is present, it may indicate an underlying medical condition or issue that requires further evaluation and treatment. In some cases, sperm agglutination may be treated with medications to reduce the production of antibodies or other substances that are causing the problem.

Exocytosis is the process by which cells release molecules, such as hormones or neurotransmitters, to the extracellular space. This process involves the transport of these molecules inside vesicles (membrane-bound sacs) to the cell membrane, where they fuse and release their contents to the outside of the cell. It is a crucial mechanism for intercellular communication and the regulation of various physiological processes in the body.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

Artificial insemination, homologous is a medical procedure where sperm from a woman's partner (the husband or male partner in a heterosexual relationship) is collected, processed and then inserted into the woman's reproductive tract through various methods to achieve fertilization and pregnancy. This method is often used when the male partner has issues with infertility, such as low sperm count or poor sperm motility, or when there are physical barriers that prevent natural conception from occurring. It is a type of artificial insemination that utilizes sperm from a genetically related source, as opposed to artificial insemination with donor (AID) sperm, which uses sperm from an anonymous or known donor.

The birth rate is the number of live births that occur in a population during a specific period, usually calculated as the number of live births per 1,000 people per year. It is an important demographic indicator used to measure the growth or decline of a population over time. A higher birth rate indicates a younger population and faster population growth, while a lower birth rate suggests an older population and slower growth.

The birth rate can be affected by various factors, including socioeconomic conditions, cultural attitudes towards childbearing, access to healthcare services, and government policies related to family planning and reproductive health. It is also influenced by the age structure of the population, as women in their reproductive years (typically ages 15-49) are more likely to give birth.

It's worth noting that while the birth rate is an important indicator of population growth, it does not provide a complete picture of fertility rates or demographic trends. Other measures, such as the total fertility rate (TFR), which estimates the average number of children a woman would have during her reproductive years, are also used to analyze fertility patterns and population dynamics.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Polar bodies are small, non-functional cells that are produced during the process of female meiosis, which results in the formation of an egg cell. They are formed when cytoplasmic divisions occur without subsequent cytokinesis, resulting in the separation of a small amount of cytoplasm and organelles from the main cell.

In the first meiotic division, a primary oocyte divides into a larger secondary oocyte and a smaller polar body, which contains half the number of chromosomes as the original cell. During the second meiotic division, the secondary oocyte divides into a larger ovum (egg) and another smaller polar body, again with half the number of chromosomes.

Polar bodies are typically extruded from the main cell and eventually disintegrate or are absorbed by surrounding cells. They do not contribute to the genetic makeup of the resulting egg or any offspring that may be produced from it. The formation of polar bodies helps ensure that the egg contains the correct number of chromosomes for normal development.

Species specificity is a term used in the field of biology, including medicine, to refer to the characteristic of a biological entity (such as a virus, bacterium, or other microorganism) that allows it to interact exclusively or preferentially with a particular species. This means that the biological entity has a strong affinity for, or is only able to infect, a specific host species.

For example, HIV is specifically adapted to infect human cells and does not typically infect other animal species. Similarly, some bacterial toxins are species-specific and can only affect certain types of animals or humans. This concept is important in understanding the transmission dynamics and host range of various pathogens, as well as in developing targeted therapies and vaccines.

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as cancer, diabetes, and neurological disorders.

Gastropoda is not a medical term, but a taxonomic category in biology. It refers to a large and diverse class of mollusks, commonly known as snails and slugs. These animals are characterized by a single, spiral-shaped shell that they carry on their backs (in the case of snails) or an internal shell (in the case of some slugs).

While Gastropoda is not a medical term per se, it's worth noting that certain species of gastropods can have medical relevance. For instance, some types of marine snails produce toxins that can be harmful or even fatal to humans if ingested. Additionally, some species of slugs and snails can serve as intermediate hosts for parasites that can infect humans, such as rat lungworms (Angiostrongylus cantonensis), which can cause a form of meningitis known as eosinophilic meningoencephalitis.

"Freezing" is a term used in the medical field to describe a phenomenon that can occur in certain neurological conditions, most notably in Parkinson's disease. It refers to a sudden and temporary inability to move or initiate movement, often triggered by environmental factors such as narrow spaces, turning, or approaching a destination. This can increase the risk of falls and make daily activities challenging for affected individuals.

Freezing is also known as "freezing of gait" (FOG) when it specifically affects a person's ability to walk. During FOG episodes, the person may feel like their feet are glued to the ground, making it difficult to take steps forward. This can be very distressing and debilitating for those affected.

It is important to note that "freezing" has different meanings in different medical contexts, such as in the field of orthopedics, where it may refer to a loss of joint motion due to stiffness or inflammation. Always consult with a healthcare professional for accurate information tailored to your specific situation.

Retrospective studies, also known as retrospective research or looking back studies, are a type of observational study that examines data from the past to draw conclusions about possible causal relationships between risk factors and outcomes. In these studies, researchers analyze existing records, medical charts, or previously collected data to test a hypothesis or answer a specific research question.

Retrospective studies can be useful for generating hypotheses and identifying trends, but they have limitations compared to prospective studies, which follow participants forward in time from exposure to outcome. Retrospective studies are subject to biases such as recall bias, selection bias, and information bias, which can affect the validity of the results. Therefore, retrospective studies should be interpreted with caution and used primarily to generate hypotheses for further testing in prospective studies.

"CBA" is an abbreviation for a specific strain of inbred mice that were developed at the Cancer Research Institute in London. The "Inbred CBA" mice are genetically identical individuals within the same strain, due to many generations of brother-sister matings. This results in a homozygous population, making them valuable tools for research because they reduce variability and increase reproducibility in experimental outcomes.

The CBA strain is known for its susceptibility to certain diseases, such as autoimmune disorders and cancer, which makes it a popular choice for researchers studying those conditions. Additionally, the CBA strain has been widely used in studies related to transplantation immunology, infectious diseases, and genetic research.

It's important to note that while "Inbred CBA" mice are a well-established and useful tool in biomedical research, they represent only one of many inbred strains available for scientific investigation. Each strain has its own unique characteristics and advantages, depending on the specific research question being asked.

Artificial insemination, heterologous (also known as donor insemination) is a medical procedure that involves the introduction of sperm from a donor into a woman's reproductive tract with the aim of achieving pregnancy. The sperm used in this procedure comes from a donor who is not the woman's sexual partner. This method may be used when the male partner has severe fertility problems, such as azoospermia (absence of sperm in the ejaculate), or when the couple has a high risk of passing on genetic disorders to their offspring. The donor sperm can be injected into the woman's uterus through intrauterine insemination (IUI) or placed directly into the cervix through intracervical insemination (ICI).

Mammals are a group of warm-blooded vertebrates constituting the class Mammalia, characterized by the presence of mammary glands (which produce milk to feed their young), hair or fur, three middle ear bones, and a neocortex region in their brain. They are found in a diverse range of habitats and come in various sizes, from tiny shrews to large whales. Examples of mammals include humans, apes, monkeys, dogs, cats, bats, mice, raccoons, seals, dolphins, horses, and elephants.

"Xenopus laevis" is not a medical term itself, but it refers to a specific species of African clawed frog that is often used in scientific research, including biomedical and developmental studies. Therefore, its relevance to medicine comes from its role as a model organism in laboratories.

In a broader sense, Xenopus laevis has contributed significantly to various medical discoveries, such as the understanding of embryonic development, cell cycle regulation, and genetic research. For instance, the Nobel Prize in Physiology or Medicine was awarded in 1963 to John R. B. Gurdon and Sir Michael J. Bishop for their discoveries concerning the genetic mechanisms of organism development using Xenopus laevis as a model system.

"Genetic crosses" refer to the breeding of individuals with different genetic characteristics to produce offspring with specific combinations of traits. This process is commonly used in genetics research to study the inheritance patterns and function of specific genes.

There are several types of genetic crosses, including:

1. Monohybrid cross: A cross between two individuals that differ in the expression of a single gene or trait.
2. Dihybrid cross: A cross between two individuals that differ in the expression of two genes or traits.
3. Backcross: A cross between an individual from a hybrid population and one of its parental lines.
4. Testcross: A cross between an individual with unknown genotype and a homozygous recessive individual.
5. Reciprocal cross: A cross in which the male and female parents are reversed to determine if there is any effect of sex on the expression of the trait.

These genetic crosses help researchers to understand the mode of inheritance, linkage, recombination, and other genetic phenomena.

Nuclear transfer techniques are scientific procedures that involve the transfer of the nucleus of a cell, containing its genetic material, from one cell to another. The most well-known type of nuclear transfer is somatic cell nuclear transfer (SCNT), which is used in therapeutic cloning and reproductive cloning.

In SCNT, the nucleus of a somatic cell (a body cell, not an egg or sperm cell) is transferred into an enucleated egg cell (an egg cell from which the nucleus has been removed). The egg cell with the new nucleus is then stimulated to divide and grow, creating an embryo that is genetically identical to the donor of the somatic cell.

Nuclear transfer techniques have various potential applications in medicine, including the creation of patient-specific stem cells for use in regenerative medicine, drug development and testing, and the study of genetic diseases. However, these procedures are also associated with ethical concerns, particularly in relation to reproductive cloning and the creation of human embryos for research purposes.

Inositol 1,4,5-trisphosphate (IP3) is a intracellular signaling molecule that plays a crucial role in the release of calcium ions from the endoplasmic reticulum into the cytoplasm. It is a second messenger, which means it relays signals received by a cell's surface receptors to various effector proteins within the cell. IP3 is produced through the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) by activated phospholipase C (PLC) enzymes in response to extracellular signals such as hormones and neurotransmitters. The binding of IP3 to its receptor on the endoplasmic reticulum triggers the release of calcium ions, which then activates various cellular processes like gene expression, metabolism, and muscle contraction.

Phosphoinositide Phospholipase C (PI-PLC) is an enzyme that plays a crucial role in intracellular signaling pathways. It catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid component of the cell membrane, into two second messengers: inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG).

IP3 is responsible for triggering the release of calcium ions from intracellular stores, while DAG remains in the membrane and activates certain protein kinase C (PKC) isoforms. These second messengers then go on to modulate various cellular processes such as gene expression, metabolism, secretion, and cell growth or differentiation. PI-PLC exists in multiple isoforms, which are classified based on their structure and activation mechanisms. They can be activated by a variety of extracellular signals, including hormones, neurotransmitters, and growth factors, making them important components in signal transduction cascades.

Endometriosis is a medical condition in which tissue similar to the lining of the uterus (endometrium) grows outside the uterine cavity, most commonly on the ovaries, fallopian tubes, and the pelvic peritoneum. This misplaced endometrial tissue continues to act as it would inside the uterus, thickening, breaking down, and bleeding with each menstrual cycle. However, because it is outside the uterus, this blood and tissue have no way to exit the body and can lead to inflammation, scarring, and the formation of adhesions (tissue bands that bind organs together).

The symptoms of endometriosis may include pelvic pain, heavy menstrual periods, painful intercourse, and infertility. The exact cause of endometriosis is not known, but several theories have been proposed, including retrograde menstruation (the backflow of menstrual blood through the fallopian tubes into the pelvic cavity), genetic factors, and immune system dysfunction.

Endometriosis can be diagnosed through a combination of methods, such as medical history, physical examination, imaging tests like ultrasound or MRI, and laparoscopic surgery with tissue biopsy. Treatment options for endometriosis include pain management, hormonal therapies, and surgical intervention to remove the misplaced endometrial tissue. In severe cases, a hysterectomy (removal of the uterus) may be recommended, but this is typically considered a last resort due to its impact on fertility and quality of life.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Fluorescent dyes are substances that emit light upon excitation by absorbing light of a shorter wavelength. In a medical context, these dyes are often used in various diagnostic tests and procedures to highlight or mark certain structures or substances within the body. For example, fluorescent dyes may be used in imaging techniques such as fluorescence microscopy or fluorescence angiography to help visualize cells, tissues, or blood vessels. These dyes can also be used in flow cytometry to identify and sort specific types of cells. The choice of fluorescent dye depends on the specific application and the desired properties, such as excitation and emission spectra, quantum yield, and photostability.

Luteinizing Hormone (LH) is a glycoprotein hormone, which is primarily produced and released by the anterior pituitary gland. In women, a surge of LH triggers ovulation, the release of an egg from the ovaries during the menstrual cycle. During pregnancy, LH stimulates the corpus luteum to produce progesterone. In men, LH stimulates the testes to produce testosterone. It plays a crucial role in sexual development, reproduction, and maintaining the reproductive system.

In medical terms, triplets are a type of multiple pregnancy, where three offsprings (fetuses) develop simultaneously in the uterus of a single pregnant woman. This occurs when a woman releases more than one egg during ovulation, and all three eggs get fertilized by separate sperm cells. Triplets can also occur through the use of assisted reproductive technologies such as in vitro fertilization (IVF) where multiple embryos are transferred into the uterus.

Triplet pregnancies carry a higher risk of complications for both the mother and the offsprings compared to singleton or twin pregnancies, including preterm labor, low birth weight, and developmental issues. As such, they often require close monitoring and specialized care throughout the pregnancy.

Calcium ionophores are chemical compounds that increase the permeability of cell membranes to calcium ions. They function by forming a complex with calcium and facilitating its transport across the lipid bilayer of the cell membrane, thereby raising the intracellular concentration of calcium ions (Ca²+).

These ionophores are often used in research and medical settings to study calcium signaling pathways and calcium-mediated cellular processes. They have been utilized in various experimental models to investigate cell proliferation, differentiation, secretion, and muscle contraction. In clinical contexts, calcium ionophores like A23187 are sometimes employed in the diagnosis of certain disorders affecting immune cells, such as detecting T-lymphocyte function in patients with suspected immunodeficiency.

However, it is essential to note that calcium ionophores can induce cytotoxicity at higher concentrations and may trigger uncontrolled calcium signaling, which could lead to cell damage or death. Therefore, their usage should be carefully controlled and monitored in both research and clinical applications.

The luteal phase is the second half of the menstrual cycle, starting from ovulation (release of an egg from the ovaries) and lasting until the start of the next menstruation. This phase typically lasts around 12-14 days in a regular 28-day menstrual cycle. During this phase, the remains of the dominant follicle that released the egg transform into the corpus luteum, which produces progesterone and some estrogen to support the implantation of a fertilized egg and maintain the early stages of pregnancy. If pregnancy does not occur, the corpus luteum degenerates, leading to a drop in hormone levels and the start of a new menstrual cycle.

'Arabidopsis' is a genus of small flowering plants that are part of the mustard family (Brassicaceae). The most commonly studied species within this genus is 'Arabidopsis thaliana', which is often used as a model organism in plant biology and genetics research. This plant is native to Eurasia and Africa, and it has a small genome that has been fully sequenced. It is known for its short life cycle, self-fertilization, and ease of growth, making it an ideal subject for studying various aspects of plant biology, including development, metabolism, and response to environmental stresses.

Aneuploidy is a medical term that refers to an abnormal number of chromosomes in a cell. Chromosomes are thread-like structures located inside the nucleus of cells that contain genetic information in the form of genes.

In humans, the normal number of chromosomes in a cell is 46, arranged in 23 pairs. Aneuploidy occurs when there is an extra or missing chromosome in one or more of these pairs. For example, Down syndrome is a condition that results from an extra copy of chromosome 21, also known as trisomy 21.

Aneuploidy can arise during the formation of gametes (sperm or egg cells) due to errors in the process of cell division called meiosis. These errors can result in eggs or sperm with an abnormal number of chromosomes, which can then lead to aneuploidy in the resulting embryo.

Aneuploidy is a significant cause of birth defects and miscarriages. The severity of the condition depends on which chromosomes are affected and the extent of the abnormality. In some cases, aneuploidy may have no noticeable effects, while in others it can lead to serious health problems or developmental delays.

Triptorelin pamoate is a synthetic analogue of the natural hormone gonadotropin-releasing hormone (GnRH). It is used in the treatment of various conditions such as endometriosis, uterine fibroids, precocious puberty, and prostate cancer.

Triptorelin pamoate works by stimulating the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland, which in turn stimulate the production of sex hormones such as estrogen and testosterone. However, with continued use, it causes downregulation of the pituitary gland, leading to a decrease in the production of FSH and LH, and therefore a reduction in the levels of sex hormones.

The pamoate salt is used to slow down the release of triptorelin, allowing for longer-acting formulations that can be administered monthly or quarterly. The medication is usually given as an injection into a muscle (intramuscularly).

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

I'm sorry for any confusion, but "soil" is not a term that has a medical definition. Soil is defined as the top layer of earth in which plants grow, a mixture of organic material, clay, sand, and silt. If you have any questions related to medicine or health, I would be happy to try to help answer them for you.

A larva is a distinct stage in the life cycle of various insects, mites, and other arthropods during which they undergo significant metamorphosis before becoming adults. In a medical context, larvae are known for their role in certain parasitic infections. Specifically, some helminth (parasitic worm) species use larval forms to infect human hosts. These invasions may lead to conditions such as cutaneous larva migrans, visceral larva migrans, or gnathostomiasis, depending on the specific parasite involved and the location of the infection within the body.

The larval stage is characterized by its markedly different morphology and behavior compared to the adult form. Larvae often have a distinct appearance, featuring unsegmented bodies, simple sense organs, and undeveloped digestive systems. They are typically adapted for a specific mode of life, such as free-living or parasitic existence, and rely on external sources of nutrition for their development.

In the context of helminth infections, larvae may be transmitted to humans through various routes, including ingestion of contaminated food or water, direct skin contact with infective stages, or transmission via an intermediate host (such as a vector). Once inside the human body, these parasitic larvae can cause tissue damage and provoke immune responses, leading to the clinical manifestations of disease.

It is essential to distinguish between the medical definition of 'larva' and its broader usage in biology and zoology. In those fields, 'larva' refers to any juvenile form that undergoes metamorphosis before reaching adulthood, regardless of whether it is parasitic or not.

Single embryo transfer (SET) is a medical procedure that involves the transplantation of a single embryo into a woman's uterus during in vitro fertilization (IVF) treatments. The aim of SET is to reduce the risk of multiple pregnancies, which can pose significant health risks to both the mother and the babies.

In IVF, multiple eggs are typically fertilized in the laboratory, resulting in several embryos. Traditionally, multiple embryos have been transferred into the uterus to increase the chances of a successful pregnancy. However, this approach also increases the risk of multiple pregnancies, which can lead to complications such as preterm labor, low birth weight, and gestational diabetes.

With SET, only one embryo is transferred, reducing the risk of multiple pregnancies while still providing a good chance of success in appropriately selected patients. The decision to perform SET is based on several factors, including the age and health of the patient, the quality of the embryos, and previous reproductive history.

Overall, single embryo transfer is a safe and effective way to increase the chances of a healthy singleton pregnancy while minimizing the risks associated with multiple pregnancies.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Povidone, also known as PVP or polyvinylpyrrolidone, is not a medication itself but rather a pharmaceutical ingredient used in various medical and healthcare products. It is a water-soluble synthetic polymer that has the ability to bind to and carry other substances, such as drugs or iodine.

In medical applications, povidone is often used as a binder or coating agent in pharmaceutical tablets and capsules. It can also be found in some topical antiseptic solutions, such as those containing iodine, where it helps to stabilize and control the release of the active ingredient.

It's important to note that while povidone is a widely used pharmaceutical ingredient, it is not typically considered a medication on its own.

Embryo research refers to the scientific study and experimentation that involves human embryos. This research is conducted in order to gain a better understanding of human development during the earliest stages of life, as well as to investigate potential treatments for various diseases and conditions.

Human embryos used in research are typically created through in vitro fertilization (IVF) procedures, in which sperm and eggs are combined in a laboratory dish to form an embryo. These embryos may be donated by individuals or couples who have undergone IVF treatments and have excess embryos that they do not plan to use for reproduction.

Embryo research can involve a variety of techniques, including stem cell research, genetic testing, and cloning. The goal of this research is to advance our knowledge of human development and disease, as well as to develop new treatments and therapies for a wide range of medical conditions. However, embryo research is a controversial topic, and there are ethical concerns surrounding the use of human embryos in scientific research.

Chromatin is the complex of DNA, RNA, and proteins that make up the chromosomes in the nucleus of a cell. It is responsible for packaging the long DNA molecules into a more compact form that fits within the nucleus. Chromatin is made up of repeating units called nucleosomes, which consist of a histone protein octamer wrapped tightly by DNA. The structure of chromatin can be altered through chemical modifications to the histone proteins and DNA, which can influence gene expression and other cellular processes.

"Paspalum" is not a medical term. It is a genus of plants, also known as "darnel grasses," which includes several species of warm-season annual and perennial grasses that are native to tropical and temperate regions around the world. Some Paspalum species are used for turfgrass, forage, or erosion control, while others can be invasive weeds in certain areas. There is no direct medical relevance of "Paspalum" as a genus of plants.

Bivalvia is a class of mollusks, also known as "pelecypods," that have a laterally compressed body and two shells or valves. These valves are hinged together on one side and can be opened and closed to allow the animal to feed or withdraw into its shell for protection.

Bivalves include clams, oysters, mussels, scallops, and numerous other species. They are characterized by their simple body structure, which consists of a muscular foot used for burrowing or anchoring, a soft mantle that secretes the shell, and gills that serve both as respiratory organs and feeding structures.

Bivalves play an important role in aquatic ecosystems as filter feeders, helping to maintain water quality by removing particles and organic matter from the water column. They are also commercially important as a source of food for humans and other animals, and their shells have been used historically for various purposes such as tools, jewelry, and building materials.

Calcimycin is a ionophore compound that is produced by the bacterium Streptomyces chartreusensis. It is also known as Calcineurin A inhibitor because it can bind to and inhibit the activity of calcineurin, a protein phosphatase. In medical research, calcimycin is often used to study calcium signaling in cells.
It has been also used in laboratory studies for its antiproliferative and pro-apoptotic effects on certain types of cancer cells. However, it is not approved for use as a drug in humans.

In medical and legal terms, "personhood" refers to the status of being a person, which is typically associated with certain legal rights, protections, and privileges. The concept of personhood is often discussed in the context of bioethics, particularly in relation to questions about the moral and legal status of entities such as fetuses, embryos, and individuals with severe cognitive impairments or in vegetative states.

The criteria for personhood are a subject of debate and vary depending on cultural, religious, philosophical, and legal perspectives. However, some common factors that are often considered include consciousness, the ability to feel pain, the capacity for self-awareness and self-reflection, the ability to communicate, and the presence of a distinct genetic identity.

In medical contexts, personhood may be relevant to issues such as end-of-life care, organ donation, and reproductive rights. For example, some argue that personhood should be granted to fetuses at the moment of conception, while others believe that personhood is only achieved when a fetus becomes viable outside the womb or when a child is born alive.

Overall, the concept of personhood is complex and multifaceted, and it continues to be debated and refined in various fields and disciplines.

Thimerosal is a mercury-containing organic compound that has been used as a preservative in various pharmaceutical products, including vaccines, to prevent contamination by bacteria. It is metabolized or degraded into ethylmercury and thiosalicylate. Ethylmercury is an organomercurial compound that is less toxic than methylmercury and is excreted from the body more quickly. Thimerosal has been used in vaccines since the 1930s, and its use has been thoroughly studied and reviewed by regulatory agencies and health organizations worldwide. No evidence has been found to link thimerosal-containing vaccines to any harmful effects, except for minor reactions at the injection site. However, due to unfounded concerns about its safety, thimerosal was removed from or reduced in most childhood vaccines in the United States and other countries as a precautionary measure, starting in the late 1990s. Despite the removal of thimerosal from most vaccines, autism rates have not decreased, which supports the conclusion that thimerosal does not cause autism.

'Caenorhabditis elegans' is a species of free-living, transparent nematode (roundworm) that is widely used as a model organism in scientific research, particularly in the fields of biology and genetics. It has a simple anatomy, short lifespan, and fully sequenced genome, making it an ideal subject for studying various biological processes and diseases.

Some notable features of C. elegans include:

* Small size: Adult hermaphrodites are about 1 mm in length.
* Short lifespan: The average lifespan of C. elegans is around 2-3 weeks, although some strains can live up to 4 weeks under laboratory conditions.
* Development: C. elegans has a well-characterized developmental process, with adults developing from eggs in just 3 days at 20°C.
* Transparency: The transparent body of C. elegans allows researchers to observe its internal structures and processes easily.
* Genetics: C. elegans has a fully sequenced genome, which contains approximately 20,000 genes. Many of these genes have human homologs, making it an excellent model for studying human diseases.
* Neurobiology: C. elegans has a simple nervous system, with only 302 neurons in the hermaphrodite and 383 in the male. This simplicity makes it an ideal organism for studying neural development, function, and behavior.

Research using C. elegans has contributed significantly to our understanding of various biological processes, including cell division, apoptosis, aging, learning, and memory. Additionally, studies on C. elegans have led to the discovery of many genes associated with human diseases such as cancer, neurodegenerative disorders, and metabolic conditions.

Body fluids refer to the various liquids that can be found within and circulating throughout the human body. These fluids include, but are not limited to:

1. Blood: A fluid that carries oxygen, nutrients, hormones, and waste products throughout the body via the cardiovascular system. It is composed of red and white blood cells suspended in plasma.
2. Lymph: A clear-to-white fluid that circulates through the lymphatic system, helping to remove waste products, bacteria, and damaged cells from tissues while also playing a crucial role in the immune system.
3. Interstitial fluid: Also known as tissue fluid or extracellular fluid, it is the fluid that surrounds the cells in the body's tissues, allowing for nutrient exchange and waste removal between cells and blood vessels.
4. Cerebrospinal fluid (CSF): A clear, colorless fluid that circulates around the brain and spinal cord, providing protection, cushioning, and nutrients to these delicate structures while also removing waste products.
5. Pleural fluid: A small amount of lubricating fluid found in the pleural space between the lungs and the chest wall, allowing for smooth movement during respiration.
6. Pericardial fluid: A small amount of lubricating fluid found within the pericardial sac surrounding the heart, reducing friction during heart contractions.
7. Synovial fluid: A viscous, lubricating fluid found in joint spaces, allowing for smooth movement and protecting the articular cartilage from wear and tear.
8. Urine: A waste product produced by the kidneys, consisting of water, urea, creatinine, and various ions, which is excreted through the urinary system.
9. Gastrointestinal secretions: Fluids produced by the digestive system, including saliva, gastric juice, bile, pancreatic juice, and intestinal secretions, which aid in digestion, absorption, and elimination of food particles.
10. Reproductive fluids: Secretions from the male (semen) and female (cervical mucus, vaginal lubrication) reproductive systems that facilitate fertilization and reproduction.

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

The uterus, also known as the womb, is a hollow, muscular organ located in the female pelvic cavity, between the bladder and the rectum. It has a thick, middle layer called the myometrium, which is composed of smooth muscle tissue, and an inner lining called the endometrium, which provides a nurturing environment for the fertilized egg to develop into a fetus during pregnancy.

The uterus is where the baby grows and develops until it is ready for birth through the cervix, which is the lower, narrow part of the uterus that opens into the vagina. The uterus plays a critical role in the menstrual cycle as well, by shedding its lining each month if pregnancy does not occur.

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

The endometrium is the innermost layer of the uterus, which lines the uterine cavity and has a critical role in the menstrual cycle and pregnancy. It is composed of glands and blood vessels that undergo cyclic changes under the influence of hormones, primarily estrogen and progesterone. During the menstrual cycle, the endometrium thickens in preparation for a potential pregnancy. If fertilization does not occur, it will break down and be shed, resulting in menstruation. In contrast, if implantation takes place, the endometrium provides essential nutrients to support the developing embryo and placenta throughout pregnancy.

Female genitalia refer to the reproductive and sexual organs located in the female pelvic region. They are primarily involved in reproduction, menstruation, and sexual activity. The external female genitalia, also known as the vulva, include the mons pubis, labia majora, labia minora, clitoris, and the external openings of the urethra and vagina. The internal female genitalia consist of the vagina, cervix, uterus, fallopian tubes, and ovaries. These structures work together to facilitate menstruation, fertilization, pregnancy, and childbirth.

I'm sorry for any confusion, but "antelopes" is a common name that refers to a group of hoofed mammals in the family Bovidae. They are not a medical term or concept. Antelopes are known for their speed and agility, and they are found primarily in Africa, with a few species in Asia.

If you have any questions related to biology, veterinary medicine, or any other scientific field, I would be happy to help answer them to the best of my ability!

Polycyctic Ovary Syndrome (PCOS) is a complex endocrine-metabolic disorder characterized by the presence of hyperandrogenism (excess male hormones), ovulatory dysfunction, and polycystic ovaries. The Rotterdam criteria are commonly used for diagnosis, which require at least two of the following three features:

1. Oligo- or anovulation (irregular menstrual cycles)
2. Clinical and/or biochemical signs of hyperandrogenism (e.g., hirsutism, acne, or high levels of androgens in the blood)
3. Polycystic ovaries on ultrasound examination (presence of 12 or more follicles measuring 2-9 mm in diameter, or increased ovarian volume >10 mL)

The exact cause of PCOS remains unclear, but it is believed to involve a combination of genetic and environmental factors. Insulin resistance and obesity are common findings in women with PCOS, which can contribute to the development of metabolic complications such as type 2 diabetes, dyslipidemia, and cardiovascular disease.

Management of PCOS typically involves a multidisciplinary approach that includes lifestyle modifications (diet, exercise, weight loss), medications to regulate menstrual cycles and reduce hyperandrogenism (e.g., oral contraceptives, metformin, anti-androgens), and fertility treatments if desired. Regular monitoring of metabolic parameters and long-term follow-up are essential for optimal management and prevention of complications.

Arabidopsis proteins refer to the proteins that are encoded by the genes in the Arabidopsis thaliana plant, which is a model organism commonly used in plant biology research. This small flowering plant has a compact genome and a short life cycle, making it an ideal subject for studying various biological processes in plants.

Arabidopsis proteins play crucial roles in many cellular functions, such as metabolism, signaling, regulation of gene expression, response to environmental stresses, and developmental processes. Research on Arabidopsis proteins has contributed significantly to our understanding of plant biology and has provided valuable insights into the molecular mechanisms underlying various agronomic traits.

Some examples of Arabidopsis proteins include transcription factors, kinases, phosphatases, receptors, enzymes, and structural proteins. These proteins can be studied using a variety of techniques, such as biochemical assays, protein-protein interaction studies, and genetic approaches, to understand their functions and regulatory mechanisms in plants.

The Y chromosome is one of the two sex-determining chromosomes in humans and many other animals, along with the X chromosome. The Y chromosome contains the genetic information that helps to determine an individual's sex as male. It is significantly smaller than the X chromosome and contains fewer genes.

The Y chromosome is present in males, who inherit it from their father. Females, on the other hand, have two X chromosomes, one inherited from each parent. The Y chromosome includes a gene called SRY (sex-determining region Y), which initiates the development of male sexual characteristics during embryonic development.

It is worth noting that the Y chromosome has a relatively high rate of genetic mutation and degeneration compared to other chromosomes, leading to concerns about its long-term viability in human evolution. However, current evidence suggests that the Y chromosome has been stable for at least the past 25 million years.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

Ovarian diseases refer to a range of conditions that affect the function and health of the ovaries, which are the female reproductive organs responsible for producing eggs (oocytes) and female hormones estrogen and progesterone. These diseases can be categorized into functional disorders, infectious and inflammatory diseases, neoplastic diseases, and other conditions that impact ovarian function. Here's a brief overview of some common ovarian diseases:

1. Functional Disorders: These are conditions where the ovaries experience hormonal imbalances or abnormal functioning, leading to issues such as:
* Polycystic Ovary Syndrome (PCOS): A condition characterized by hormonal imbalances that can cause irregular periods, cysts in the ovaries, and symptoms like acne, weight gain, and infertility.
* Functional Cysts: Fluid-filled sacs that develop within the ovary, usually as a result of normal ovulation (follicular or corpus luteum cysts). They're typically harmless and resolve on their own within a few weeks or months.
2. Infectious and Inflammatory Diseases: These conditions are caused by infections or inflammation affecting the ovaries, such as:
* Pelvic Inflammatory Disease (PID): An infection that spreads to the reproductive organs, including the ovaries, fallopian tubes, and uterus. It's often caused by sexually transmitted bacteria like Chlamydia trachomatis or Neisseria gonorrhoeae.
* Tuberculosis (TB): A bacterial infection that can spread to the ovaries and cause inflammation, abscesses, or scarring.
3. Neoplastic Diseases: These are conditions where abnormal growths or tumors develop in the ovaries, which can be benign (non-cancerous) or malignant (cancerous). Examples include:
* Ovarian Cysts: While some cysts are functional and harmless, others can be neoplastic. Benign tumors like fibromas, dermoids, or cystadenomas can grow significantly larger and cause symptoms like pain or bloating. Malignant tumors include epithelial ovarian cancer, germ cell tumors, and sex cord-stromal tumors.
4. Other Conditions: Various other conditions can affect the ovaries, such as:
* Polycystic Ovary Syndrome (PCOS): A hormonal disorder that causes enlarged ovaries with small cysts. It's associated with irregular periods, infertility, and increased risk of diabetes, high blood pressure, and heart disease.
* Premature Ovarian Failure (POF): Also known as primary ovarian insufficiency, it occurs when the ovaries stop functioning before age 40, leading to menstrual irregularities, infertility, and early onset of menopause.

It's essential to consult a healthcare professional if you experience any symptoms related to your reproductive system or suspect an issue with your ovaries. Early detection and treatment can significantly improve the prognosis for many conditions affecting the ovaries.

Diploidy is a term used in genetics to describe the state of having two sets of chromosomes in each cell. In diploid organisms, one set of chromosomes is inherited from each parent, resulting in a total of 2 sets of chromosomes.

In humans, for example, most cells are diploid and contain 46 chromosomes arranged in 23 pairs. This includes 22 pairs of autosomal chromosomes and one pair of sex chromosomes (XX in females or XY in males). Diploidy is a characteristic feature of many complex organisms, including animals, plants, and fungi.

Diploid cells can undergo a process called meiosis, which results in the formation of haploid cells that contain only one set of chromosomes. These haploid cells can then combine with other haploid cells during fertilization to form a new diploid organism.

Abnormalities in diploidy can lead to genetic disorders, such as Down syndrome, which occurs when an individual has three copies of chromosome 21 instead of the typical two. This extra copy of the chromosome can result in developmental delays and intellectual disabilities.

... (IVF) is an assisted reproductive technique designed to closely mimic a woman's natural ... Natural Cycle IVF is in vitro fertilisation (IVF) using either of the following procedures: IVF without the use any ovarian ... "Natural cycle in vitro fertilisation (IVF) for subfertile couples" (PDF). The Cochrane Database of Systematic Reviews. 8 (8): ... "ISMAAR » Osamu Kato". Natural cycle IVF Archived 2012-05-12 at the Wayback Machine at the Human Fertilisation and Embryology ...
... (IVF) is a process of fertilisation where an egg is combined with sperm in vitro ("in glass"). The ... outcome of parenthood project during in vitro fertilization and after discontinuation of unsuccessful in vitro fertilization". ... "Is In Vitro Fertilization Being Overused?". CBS News. 12 August 2009. Smajdor A (May 2011). "The ethics of IVF over 40". ... "In vitro fertilization (IVF) - Mayo Clinic". www.mayoclinic.org. Retrieved 29 October 2022. van Loendersloot LL, van Wely M, ...
The history of in vitro fertilisation (IVF) goes back more than half a century. In 1959 the first birth in a nonhuman mammal ... Carl Wood was dubbed "the father of IVF (in vitro fertilisation)" for having pioneered the use of frozen embryos. In the US, ... In 1959, Min Chueh Chang at the Worcester Foundation, proved fertilisation in vitro was capable of proceeding to a birth of a ... The first pregnancy achieved through in vitro human fertilisation of a human oocyte was reported in The Lancet from the Monash ...
Pre-implantation genetic diagnosis (PGD) is used in conjunction with in-vitro fertilization. In-vitro fertilization is the ... In vitro fertilization". The New England Journal of Medicine. 356 (4): 379-86. doi:10.1056/NEJMcp065743. PMID 17251534. Levy B ... process of combining an egg (oocyte) and sperm outside of the body with intent of fertilization. PGD is the testing of ...
ISBN 978-1-4471-2392-7. Elder K, Dale B (2 December 2010). In-Vitro Fertilization. Cambridge University Press. pp. 26-. ISBN ... An in vitro study using porcine skin and several formulations of transdermal progesterone found that only minute quantities of ...
In vitro fertilization is the technique of letting fertilization of the male and female gametes (sperm and egg) occur outside ... In vitro fertilization". N Engl J Med. 356 (4): 379-86. doi:10.1056/NEJMcp065743. PMID 17251534. Kurinczuk JJ, Hansen M, Bower ... Olson CK, Keppler-Noreuil KM, Romitti PA, Budelier WT, Ryan G, Sparks AE, Van Voorhis BJ (2005). "In vitro fertilization is ... PGD is an adjunct to ART procedures, and requires in vitro fertilization to obtain oocytes or embryos for evaluation. Embryos ...
"In Vitro Fertilization". GMA Drama. "GMA Drama: May 12". Facebook. Retrieved May 17, 2023. "Pagnakaw ng Punla". GMA Drama. "GMA ... A husband and wife tackle the challenges of going through the process of an In-vitro fertilization. Lead cast Glaiza de Castro ...
In Vitro Fertilization; Goose Bumps; Hummingbirds (October 30, 1993) Newspaper; Bomb Squad; Echoes; Mosquitoes (November 6, ...
Louise Brown In vitro fertilization Sullivan, Walter (1981-12-29). "'Test-Tube' Baby Born in U.S., Joining Successes Around ... Elizabeth Jordan Carr (born December 28, 1981 at 7:46 am) is the United States' first baby born from the in-vitro fertilization ... Joe Holley (28 March 2005). "Georgeanna Jones Dies at 92; In Vitro Fertilization Pioneer". Washington Post. p. B04. Retrieved ... In vitro fertilisation, Simmons University alumni, Writers from Norfolk, Virginia, Living people, Journalists from Virginia, ...
Medical experts therefore recommend considering in vitro fertilization after one failed COH/IUI cycle for women aged over 40 ... Seattle Sperm Bank Adams, Robert (1988). in vitro fertilization technique. Monterey CA.{{cite book}}: CS1 maint: location ... Timing is critical, as the window and opportunity for fertilization is little more than twelve hours from the release of the ... Using this technique, as with ICI, fertilisation takes place naturally in the external part of the fallopian tubes in the same ...
IVF, or in vitro fertilisation, is when mature eggs are collected from ovaries and fertilized by sperm in a lab and then ... "In vitro fertilization (IVF)". Mayo Clinic. Mayo Clinic. Retrieved May 15, 2020. Griffiths A. "Aneuploidy". An Introduction to ... Preimplantation refers to the state of existing or occurring between the fertilization of an ovum and its implementation in the ...
... an in vitro fertilization program; and special pharmaceutical services. A portion of land on the UMMC campus was once the site ... an in vitro fertilization program; and special pharmaceutical services. In 2007, professional football standout Eli Manning ...
Sequeira PM (2011). "Anesthesia for in vitro fertilization". In Urman RD, Gross WL, Philip BK (eds.). Anesthesia outside of the ... Transvaginal oocyte retrieval (TVOR), also referred to as oocyte retrieval (OCR), is a technique used in in vitro fertilization ... 1997). "Ureteral lesion secondary to vaginal ultrasound follicular puncture for oocyte recovery in in-vitro fertilization". ... "The role of seminal plasma for improved outcomes during in vitro fertilization treatment: review of the literature and meta- ...
First in vitro fertilization baby. In January 1993 Integris opened a free, all volunteer healthcare clinic to provide ...
"In vitro fertilization (IVF) - Mayo Clinic". www.mayoclinic.org. Retrieved 2023-07-26. Kumar P, Sait SF, Sharma A, Kumar M (May ... Today, one of the most effective forms of ART is in vitro fertilization (IVF). While it is very effective in those experiencing ... Regenerative medicine has been used for premature ovarian failure and will continue to be studied for in vitro fertilization ( ... Raff M, DeCherney A (August 2019). "Reproductive surgery and in vitro fertilization: the future reevaluated". Fertility and ...
As of August 2007, she a'nd her team were responsible for the birth of 500 babies through in vitro fertilization. She is ... In In 1998, Gwet-Bell supervised the birth of the first Cameroonian child born through in vitro fertilization. The baby was ... Ernestine Gwet-Bell (born 1953) is a gynaecologist from Cameroon, who supervised the first successful in vitro fertilisation ( ... Kovacs, Gabor; Brinsden, Peter; DeCherney, Alan (2018-06-14). In-Vitro Fertilization: The Pioneers' History. Cambridge ...
... allows oocytes from the ovarian tissue to be used directly for in vitro fertilization, as an alternative to ... doi:10.1016/s0921-4488(99)00097-8. Niwa K (1993). "Effectiveness of in vitro maturation and in vitro fertilization techniques ... they can then be fertilised in vitro, known as in vitro fertilisation (IVF). Techniques such as intracytoplasmic sperm ... "Effect of oocyte harvesting techniques on in vitro maturation and in vitro fertilization in sheep". Small Ruminant Research. 36 ...
Chang, M. C. (1959). "Fertilization of Rabbit Ova in vitro". Nature. 184 (4684): 466-67. Bibcode:1959Natur.184..466C. doi: ... grown from ova having undergone in vitro fertilisation and transferred to a surrogate mother. The term pheromone is coined. ...
"Identical twins and in vitro fertilization". Journal of In Vitro Fertilization and Embryo Transfer. 3 (2): 114-117. doi:10.1007 ... Artificial induction of ovulation and in vitro fertilization-embryo replacement can also give rise to fraternal and identical ... "Outcome in 242 in vitro fertilization-embryo replacement or gamete intrafallopian transfer-induced pregnancies". Fertility and ...
Ovulation Induction and in Vitro Fertilization. Year Book Medical Publishers. p. 113. ISBN 978-0-8151-0871-9. Sweetman, Sean C ...
In vitro fertilization generates multiple embryos. The surplus of embryos is not clinically used or is unsuitable for ... After 4-6 days of this intrauterine culture, the embryos are harvested and grown in in vitro culture until the inner cell mass ... Human embryos reach the blastocyst stage 4-5 days post fertilization, at which time they consist of 50-150 cells. Isolating the ... Studies have shown that cardiomyocytes derived from ESCs are validated in vitro models to test drug responses and predict ...
30-minute documentary on Vitro Fertilization. Interviewees included Patrick Steptoe CBE and Professor Robert Winston. Co- ...
For 30 years, he was editor of the Journal of In Vitro Fertilization and Embryo Transfer, now known as the Journal of Assisted ... In 1982 was appointed as founding editor-in-chief of The Journal of In Vitro Fertilization and Embryo Transfer (JIVF-ET), ... "New form of in vitro fertilization stirs debate". St. Louis Post. Retrieved 2020-04-19. "Why a gentler, less costly approach to ... His department established the first in vitro fertilization (IVF) program in the city of Chicago and the Midwest. Gleicher ...
In vitro fertilization occurs in a laboratory. The process of in vitro fertilization is when mature eggs are removed from the ... "In vitro fertilization (IVF) - Mayo Clinic". www.mayoclinic.org. Retrieved 2022-04-11. Asplund, Kjell (2020). "Use of in vitro ... 14 days after fertilization the primitive streak forms. The formation of the primitive streak has been known to some countries ... There have been a number of attempts to understand the processes of gastrulation using in vitro techniques in parallel and ...
It is also commonly used during in vitro fertilization (IVF). Estrogen helps maintain the endometrial lining of the uterus and ... Clinical Infertility and In Vitro Fertilization. JP Medical Ltd. pp. 11-. ISBN 978-93-5025-095-2. Archived from the original on ... "Role of cytochrome P450 in estradiol metabolism in vitro". Acta Pharmacologica Sinica. 22 (2): 148-154. PMID 11741520. Schubert ...
According to In-Vitro Fertilisation website source, "In 1995, Dmitri Dozortsev and his coworkers A. Rybouchkin, Petra De Sutter ... In particular, he is best known for his studies of in vitro fertilisation and embryo transfer. Dozortsev currently serves as ... "The History of IVF -The Milestones (Year 1995 Milestone - Paragraph 6)". In-Vitro Fertilisation. Dozortsev, Dmitri; Serafim, ... "Fertilization and early embryolgoy: Human oocyte activation following intracytoplasmic injection: the role of the sperm cell". ...
She was conceived via in vitro fertilization. Her middle name, Eilish, was originally meant to be her first name, while Pirate ...
Gardner DK, Simón C (26 June 2017). Handbook of In Vitro Fertilization (Fourth ed.). CRC Press. pp. 131-. ISBN 978-1-4987-2947- ... which is an essential component in in vitro fertilisation (IVF). Typically, after GnRH agonists have induced a state of ... discontinuation of gonadotrophin-releasing hormone agonist administration in short-term protocol for in-vitro fertilization". ...
"Ontario to cover in-vitro fertilization treatments". The Star. Toronto. Retrieved 2017-01-25. "When think tanks produce ... expand the reproductive rights of women and men by compelling the Ontario Health Insurance Plan to fund in vitro fertilization ...
It concerns a wide range of scientific and technological approaches: from in vitro diagnostics to in vitro fertilisation, from ... "New challenges in human in vitro fertilization". Science. 260 (5110): 932-936. Bibcode:1993Sci...260..932W. doi:10.1126/science ... In vitro Diagnostics - EDMA Archived November 11, 2013, at the Wayback Machine Winston, R. M.; Handyside, A. H. (14 May 1993 ... Oxford: Blackwell Publishing (2007). 6. is Health, Center for Devices and Radiological (2019-10-25). "In Vitro Diagnostics". ...
Natural Cycle In Vitro Fertilization (IVF) is an assisted reproductive technique designed to closely mimic a womans natural ... Natural Cycle IVF is in vitro fertilisation (IVF) using either of the following procedures: IVF without the use any ovarian ... "Natural cycle in vitro fertilisation (IVF) for subfertile couples" (PDF). The Cochrane Database of Systematic Reviews. 8 (8): ... "ISMAAR » Osamu Kato". Natural cycle IVF Archived 2012-05-12 at the Wayback Machine at the Human Fertilisation and Embryology ...
In Vitro Fertilization Risks Babies conceived through in vitro fertilization are significantly more likely to suffer ... more twins and triplets are born using in vitro fertilization. But governments are increasingly unwilling to pay for the health ... considering limiting the number of fertilized embryos placed into a womans uterus during the course of in vitro fertilization ... Share In Vitro Fertilization Risks on Twitter (X) Share In Vitro Fertilization Risks on LinkedIn ...
UCSF offers a range of in vitro fertilization (IVF) options - including innovative treatments pioneered here - for couples ... In vitro fertilization (IVF) involves fertilization outside the body in an artificial environment. IVF was first successfully ... Pre-implantation genetic diagnosis (PGD) is a lab procedure used with in vitro fertilization (IVF) to reduce the risk of ... The natural process of embryo development begins with the fertilization of the egg in the outer aspect of the fallopian tube. ...
Shortly after my insights on the clinical problems with in vitro fertilization were published, http://www.all.org/newsroom_ ... As long as in vitro fertilization and its progeny bring in the big money, there wont be a huge outpouring of support from the ... This is because the price of in vitro fertilization treatment can be upwards of $15,000, with no guarantee of success. The ... There may well be additional clinical reports that address the downside of in vitro fertilization as it affects the woman - and ...
Ontario says it will fund one cycle of in-vitro fertilization for eligible women up to the age of 42, a change that women who ... Ontario increasing in-vitro fertilization funding by $50M a year. Ontario says it will fund one cycle of in-vitro fertilization ... Ontario says it will fund one cycle of in-vitro fertilization for eligible women up to the age of 42, a change that women who ... Last April, Ontario announced it would fund in-vitro fertilization for people unable to have children otherwise, and would pay ...
In Vitro Fertilization If other fertility treatments havent worked, you may feel discouraged about the possibility of starting ... In vitro fertilization, or IVF, is a specialized procedure to help you get pregnant when other fertility treatments are ... But in vitro fertilization (IVF), an advanced fertility treatment, has helped many couples get pregnant when other fertility ... Step 4: Egg Fertilization. Retrieved eggs undergo examination by a gamete biologist for maturity and viability. We then place ...
Learn more about in vitro fertilization procedures at NewYork-Presbyterian. ... In vitro fertilization is a procedure to help with fertility by combining an egg with sperm in vitro. ... What is In Vitro Fertilization (IVF)? What is IVF? In vitro fertilization is the process in which an egg is fertilized by a ... In Vitro Fertilization at NewYork-Presbyterian Get Care At NewYork-Presbyterian, a full range of reproductive assistance ...
In Vitro Fertilization /IVF Market, by Key Countries. 4.2. In Vitro Fertilization /IVF Market Opportunity Assessment (US$ Mn). ... Global In Vitro Fertilization /IVF Market Analysis 2015-2021 and Forecast 2022-2032, By End User ... 8. Global In Vitro Fertilization /IVF Market Analysis 2015-2021 and Forecast 2022-2032, By Product ... 9. Global In Vitro Fertilization /IVF Market Analysis 2015-2021 and Forecast 2022-2032, By Cycle ...
Risk for Miscarriage and Failure of In Vitro Fertilization Can Be Predicted. ... causing early miscarriage and in vitro fertilization (IVF) failure.. Recent studies have shown that genes predispose certain ...
Our Orange County fertility specialist explains how in vitro fertilization, or IVF, can make family-building dreams come true. ... In vitro fertilization brings couples one step closer to starting a family. Dont leave such an important decision to chance. ... Basic in vitro fertilization steps. When our Orange County fertility specialists perform IVF, it involves several steps to help ... We are known for our expertise, compassion and ability to provide affordable in vitro fertilization options. We also use ...
In vitro fertilization is a commonly used technique with a variety of model organisms to maintain lab populations and produce ... In Vitro Fertilization Signs Of Successful Fertilization Genetic Constructs Injection Developmental Analysis Normal Working ... Gamete Collection and In Vitro Fertilization of Astyanax mexicanus. Article DOI: 10.3791/59334-v • 10:52 min • May 25th, 2019 ... we demonstrate how to produce viable offspring using in vitro fertilization and discuss signs of successful fertilization. We ...
In vitro fertilization affects the regulatory region of genes essential for placental and embryonic growth, as well as the ... In vitro fertilization affects the regulatory region of genes essential for placental and embryonic growth, as well as the ... It is known that in vitro fertilization, IVF, can affect the size of the newborns. Children derived from fresh embryo transfer ... Novel information about the effects of in vitro fertilization on embryonic growth ...
In vitro fertilization linked to increase risk for birth defects ... In vitro fertilization linked to increase risk for birth ... In vitro fertilization (IVF) may significantly increase the risk of birth defects, particularly those of the eye, heart, ... "For parents considering in vitro fertilization or other forms of assisted reproductive technology, it is important that they ... such as certain types of in vitro fertilization, and an increased risk of birth defects," said study author Lorraine Kelley- ...
... Raoul Orvieto. 1 ... F. Vural, B. Vural, and Y. Çakıroğlu, "The role of overweight and obesity in in vitro fertilization outcomes of poor ovarian ... "The influence of body mass index on in vitro fertilization outcome," International Journal of Gynecology and Obstetrics, vol. ... and showed significantly lower fertilization rate. Moreover, in agreement with Vural et al. [1], obese poor responder patients ...
Books for Scientists on in vitro fertilization, fertility & reproduction. ... 3. In Vitro Fertilisation: 4th Edition 4. New Book - In Vitro Fertilization: A Textbook of Current and Emerging Methods and ... 2. In Vitro Fertilization: A Practical Approach. 3. In Vitro Fertilization - 3rd Edition. 4. Quality and Risk Management in the ... In Vitro Fertilization. In vitro fertilization (IVF) involves combining an egg and sperm within a laboratory setting to create ...
... In vitro fertilization linked with increased ... when women become pregnant via in vitro fertilization (IVF) than through spontaneous conception. The systematic review and meta ... when women become pregnant via in vitro fertilization (IVF) compared with through spontaneous conception. ... In vitro fertilization linked with increased risk of spontaneous preterm birth. http://onlinelibrary.wiley.com/doi/10.1002/uog. ...
B. In vitro fertilization (IVF) and what happens to un-implanted embryos. 1. Video clips, animations, and discussion of the IVF ... Unit 1: Embryonic Stem Cells, Natural and In Vitro Fertilization, Preimplantation Genetic Diagnosis. By Kathy Keeran, Lonnie ... 2. Animation of natural fertilization. 3. Virtual lab - sea urchin fertilization and development. 4. Human embryonic ... A. Natural fertilization and origins of stem cells; development of embryonic stem cell lines. 1. Lecture with PowerPoint - ...
... , California Fertility Partners is a Los Angeles Fertility clinic dedicated to the evaluation and ... In Vitro Fertilization (IVF). In Vitro Fertilization. What is in vitro fertilization (IVF)?. In Vitro Fertilization (IVF) is an ... Our embryologist then mixes the eggs with sperm or assists fertilization by sperm injection (ICSI). The embryos are then ... In Vitro Fertilization (IVF)*In Vitro Fertilization. * Intracytoplasmic Sperm Injection (ICSI). * Preimplantation Genetic ...
Body mass index and its effect on in vitro fertilization pregnancy rates - A womans weight can affect her fertility. We know ...
In vitro fertilisation (IVF). Human Fertilisation and Embyrology Authority. www.hfea.gov.ukOpens a new window [Accessed January ... IVF: what is in vitro fertilisation (IVF) and how does it work? Human Fertilisation and Embyrology Authority. www.hfea.gov.uk ... The impact of in vitro fertilization on health of the children: an update. Eur J Obstet Gynecol Reprod Biol 154(2):125-9 ... Fertilisation takes place in this dish, in vitro, which means in glass.. ...
After six in vitro fertilization attempts, Celine Dion and her husband Rene Angélil gave birth to their son René-Charles in ... conceived through in vitro fertilization. Their daughter, Luna Simone Stephens, was born in April 2016. ... used gestational surrogates after undergoing in-vitro to have their babies. Got baby fever? Check out Rankers list of famous ...
"The Great Recession, Insurance Mandates, and the Use of In Vitro Fertilization Services in the United States." Fertility and ... The Great Recession, Insurance Mandates, and the Use of In Vitro Fertilization Services in the United States. ... and the use of in vitro fertilization (IVF) in the United States.. Design: We examined the correlation between the coincident ...
Scientists have made a step toward bringing the northern white rhino back from near extinction in the wild by producing new embryos in a lab. Since 2019, the BioRescue consortium,.... ...
Should parents undergoing in vitro fertilization have the right to choose which embryos to implant based on genetic criteria, ... Should parents undergoing in vitro fertilization have the right to choose which embryos to implant based on genetic criteria, ... Master Fertilization with a bite sized video explanation from. Jason Amores Sumpter ...
Covid-19: Impact on In Vitro Fertilization Market in Europe to Achieve High Worldwide Growth and Opportunities. February 20th, ... This is due to favorable regulations including Human Fertilization and Embryo authority (HFEA) of the U.K., that offers ...
Hopefully at the end of the in vitro fertilization (IVF) process, you will be pregnant, and an ultrasound will be scheduled 4-5 ... Hopefully at the end of the in vitro fertilization (IVF) process, you will be pregnant, and an ultrasound will be scheduled 4-5 ...
In Vitro Fertilisation (distance learning) PGDip. How to apply for Clinical Embryology & In Vitro Fertilisation (distance ... In Vitro Fertilisation (distance learning) PGDip course. ... In Vitro Fertilisation (distance learning) PGDip. Start date. ...
In vitro fertilization and embryo transfer (IVF-ET) and gamete intrafallopian transfer (GIFT) are used to treat intractable ... a possible alternative to gamete intrafallopian transfer and in vitro fertilization. Dodson, WC., Whitesides, DB., Hughes, C., ... a possible alternative to gamete intrafallopian transfer and in vitro fertilization. Fertility and Sterility, 48(3), 441-445. ... a possible alternative to gamete intrafallopian transfer and in vitro fertilization ...

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