Dwarfism
Pituitary Gland
Pituitary Neoplasms
Pituitary Gland, Anterior
Pituitary Diseases
Achondroplasia
Pituitary Hormones
Pituitary Apoplexy
Growth Hormone
Pituitary Hormones, Anterior
Microcephaly
Pituitary Adenylate Cyclase-Activating Polypeptide
Pituitary Gland, Posterior
Receptor, Fibroblast Growth Factor, Type 3
Prolactin
Bone Diseases, Developmental
Prolactinoma
Gonadotropins, Pituitary
Thanatophoric Dysplasia
Growth Hormone-Secreting Pituitary Adenoma
Dwarfism, Pituitary
Hypopituitarism
Pituitary ACTH Hypersecretion
Adrenocorticotropic Hormone
ACTH-Secreting Pituitary Adenoma
Luteinizing Hormone
Growth Hormone-Releasing Hormone
Thyroid (USP)
Gonadotropin-Releasing Hormone
Bone Development
Thyrotropin-Releasing Hormone
Cyclic GMP-Dependent Protein Kinase Type II
Gigantism
Brassinosteroids
Steroids, Heterocyclic
Pituitary Hormone-Releasing Hormones
Receptors, Pituitary Hormone
Receptors, Somatotropin
Chondrodysplasia Punctata
Follicle Stimulating Hormone
Abnormalities, Multiple
Adenoma, Chromophobe
Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
Pro-Opiomelanocortin
Gonadotrophs
Mutation
Osteopoikilosis
Receptors, LHRH
Sella Turcica
Phenotype
Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
Cholestanols
Pituitary Gland, Intermediate
Thyrotropin
Gibberellins
Limb Deformities, Congenital
Follicle Stimulating Hormone, beta Subunit
Cartilage
Human Growth Hormone
Receptors, Pituitary Hormone-Regulating Hormone
RNA, Messenger
Hypothalamus
Luteinizing Hormone, beta Subunit
Hypophysectomy
Molecular Sequence Data
Metatarsal Bones
Bone and Bones
Glycoprotein Hormones, alpha Subunit
Thymic hormone activity and spontaneous autoimmunity in dwarf mice and their littermates. (1/140)
Serum thymic hormone activity (TA) was determined in hereditary hypopituitary dwarf mice (dw/dw) and their littermates (+/dw or +/+). It was found to be very low in the dwarf animals in comparison to their littermates. At 14 weeks of age, the dwarf littermates exhibited significant glomerular lesions characterized by deposits of IgG, IgG1, IgG2, IgA, IgM and C3, which were augmented by thymectomy of adult females. In contrast, hypopituitary dwarf mice had minimal glomerular deposits of immunoglobulins. Unlike these animals, their littermates showed antinuclear antibodies (ANA) and anti-deoxyribonucleic acid (DNA) antibodies in their serum. The present findings are discussed in relation to recent hypotheses on: (1) the role of the hypophysis in thymus-dependent immunological functions; and (2) the significance of T-cell deficiency in the development of autoimmunity. (+info)Growth hormone resistance: clinical states and animal models. (2/140)
GH exerts pleiotropic effects on growth and metabolism through the GH receptor. A deficiency in the GH receptor gene is thus associated with GH resistance and dwarfism. Complete GH resistance in humans, or Laron syndrome, has been associated with numerous inherited defects in the GH receptor, including point mutations, complete or partial gene deletions, and splice site alterations. Analysis of the GH receptor genes of these patients has provided considerable insight into structure-function relationships of the GH receptor. However, the relative rarity of this disease and the obvious difficulties involved in human research have prompted a search for an animal model of GH resistance. Numerous models have been proposed, including the sex-linked dwarf chicken, the guinea pig, and the Laron mouse. In this review, the characteristics and etiology of Laron syndrome and these animal models will be discussed. The insight provided by these disorders into the roles and mechanism of action of GH will also be reviewed. (+info)Disruption of differentiated functions during viral infection in vivo. V. Mapping of a locus involved in susceptibility of mice to growth hormone deficiency due to persistent lymphocytic choriomeningitis virus infection. (3/140)
Lymphocytic choriomeningitis virus (LCMV) Armstrong strain selectively and persistently infects the majority of growth hormone (GH) producing cells in the anterior lobe of pituitary glands of C3H/St mice but negligibly infects GH producing cells of BALB/WEHI mice (Oldstone et al., Virology 142, 175--182, 1985; Oldstone et al., Science 218, 1125--1127, 1982). Although infected GH cells remain free of structural damage, disrupted initiation of GH transcription (Klavinskis and Oldstone, J. Gen. Virol. 68, 1867--1873, 1989; Valsamakis et al., Virology 156, 214--220, 1987) occurs with a resultant decrease in the synthesis of GH, leading to a failure of growth and development (Oldstone et al., Science 218, 1125--1127, 1982). Microsatellite mapping of DNA obtained from 101 individual C3H/St x BALB/WEHI F1 x F1 mice shows that the growth failure correlates with host genes linked (P value 0.0008) on chromosome 17 just outside of the H-2D MHC site between D17 Mit24 and D17 Mit51, a distance of 2.5 cM. The genetic mapping done here excludes alpha-dystroglycan (alpha-DG), a known receptor for LCMV (Cao et al., Science 282, 2079--2081, 1998) in pathogenesis of GH disease, as alpha-DG is encoded in the mouse by a gene residing on chromosome 9 (Yotsumoto et al., Hum. Mol. Genet. 5, 1259--1267, 1996). (+info)Diagnostic interest of acid-labile subunit measurement in relationship to other components of the IGF system in pediatric patients with growth or eating disorders. (4/140)
OBJECTIVE: To analyze the possible utility of measuring acid-labile subunit (ALS) in some types of pathologies in which the IGF system is altered and to compare it with the clinical implications of measurements of other components of this axis. DESIGN AND METHODS: We studied serum ALS concentrations in 20 children with normal variants of short stature (NVSS) at diagnosis and 24 with growth hormone deficiency (GHD), 18 obese patients and 18 girls with anorexia nervosa at diagnosis and during a follow-up period. RESULTS: In patients with GHD and anorexia nervosa, mean ALS concentrations were significantly reduced, but there was a high percentage of overlap with control values. At diagnosis, ALS concentrations were normal in obese patients and children with NVSS. During follow-up, these values normalized in children with GHD who were treated with GH, tended to normalize in those with anorexia nervosa who showed weight gain, and did not change in obese children upon weight loss. However, ALS measurement was less accurate than that of IGF-I or IGF binding protein (IGFBP)-3 in diagnosis of GHD. The correlations found between ALS and some IGF system components at diagnosis either decreased or were non-significant during follow-up of these clinical conditions. CONCLUSION: ALS adds little information to that obtained with IGF-I and IGFBP-3 determinations. (+info)Deficiency of growth hormone-releasing hormone signaling is associated with sleep alterations in the dwarf rat. (5/140)
The somatotropic axis, and particularly growth hormone-releasing hormone (GHRH), is implicated in the regulation of sleep-wake activity. To evaluate sleep in chronic somatotropic deficiency, sleep-wake activity was studied in dwarf (dw/dw) rats that are known to have a defective GHRH signaling mechanism in the pituitary and in normal Lewis rats, the parental strain of the dw/dw rats. In addition, expression of GHRH receptor (GHRH-R) mRNA in the hypothalamus/preoptic region and in the pituitary was also determined by means of reverse transcription-PCR, and GHRH content of the hypothalamus was measured. Hypothalamic/preoptic and pituitary GHRH-R mRNA levels were decreased in the dw/dw rats, indicating deficits in the central GHRHergic transmission. Hypothalamic GHRH content in dw/dw rats was also less than that found in Lewis rats. The dw/dw rats had less spontaneous nonrapid eye movement sleep (NREMS) (light and dark period) and rapid eye movement sleep (REMS) (light period) than did the control Lewis rats. After 4 hr of sleep deprivation, rebound increases in NREMS and REMS were normal in the dw/dw rat. As determined by fast Fourier analysis of the electroencephalogram (EEG), the sleep deprivation-induced enhancements in EEG slow-wave activity in the dw/dw rats were only one-half of the response in the Lewis rats. The results are compared with sleep findings previously obtained in GHRH-deficient transgenic mice. The alterations in NREMS are attributed to the defect in GHRH signaling, whereas the decreases in REMS might result from the growth hormone deficiency in the dw/dw rat. (+info)Growth hormone deficiency in adults and clinical use of recombinant human growth hormone. (6/140)
OBJECTIVE: To review the modern recognition of growth hormone deficiency (GHD) in adults and the beneficial effects of growth hormone (GH) treatment in such cases. DATA SOURCES AND METHODS: Most published original articles about GH and GHD in recent domestic and world wide related literatures were available. STUDY SELECTION: More than 65 originally identified articles were reviewed and 29 were selected that especially addressed the stated purpose. RESULTS: Treatment of GHD in adult human beings became an option following the development of rhGH and the numerous reports on the effect of rhGH therapy in such patients. The syndrome of GH deficiency in adults principally comprises abnormalities in body composition, cardiovascular risk factor, and psychological well-being. In comparison with normal individuals, these patients have increased total-body fat mass (particularly visceral adiposity), reduced muscle mass, reduced muscle strength exercise performance, and reduced bone mass. The psychological dysfunction comprises self-reported reduction in energy, mood, and sleep, along with objective reductions in marital and socioeconomic performance. CONCLUSION: The evidence that rhGH administration may be beneficial for the prevention, as well as treatment, of various clinical situations. (+info)Collagen markers deoxypyridinoline and hydroxylysine glycosides: pediatric reference data and use for growth prediction in growth hormone-deficient children. (7/140)
BACKGROUND: In children and adolescents, markers of bone and collagen metabolism reflect the dynamics of skeletal growth and development. The aim of this study was to assess the relationship of the urinary collagen markers deoxypyridinoline (DPD) and hydroxylysine (Hyl) and its glycosides [galactosyl-Hyl (Gal-Hyl) and glucosyl-Gal-Hyl] with growth. METHODS: Urine samples from 240 apparently healthy children and adolescents (6-19 years; 124 girls) and from 51 prepubertal children with growth hormone (GH) deficiency (3-14 years; 14 girls) were analyzed. Urinary Hyl and its glycosides were quantified by HPLC, and DPD was assessed by chemiluminescence assay. Urinary concentrations of all markers were related to urinary creatinine. RESULTS: Multiple regression analysis revealed that only age and height velocity were independently associated with these markers in healthy children. In GH-deficient patients, the urinary excretion of both analytes after 4 weeks of GH therapy correlated significantly with the height increase during the first treatment year (r = 0.79 for Gal-Hyl; r = 0.70 for DPD; P <0.001 each). In a multivariate linear regression model using Gal-Hyl concentrations at 4 weeks, baseline concentrations of insulin-like growth factor 1 and height velocity after 3 months accounted for 80% of the variability in height gain during the first treatment year. A model using DPD concentrations at 4 weeks, in place of Gal-Hyl concentrations, as well as baseline concentrations of insulin-like growth factor 1 and height velocity after 3 months accounted for 83% of the variability. CONCLUSIONS: These urinary bone and collagen markers give some early indication of growth response, but the prediction of an individual marker is too imprecise to serve as a basis for clinical decisions. Markers of bone and collagen metabolism might be more useful as components of multivariate growth prediction models. (+info)Measurement of IGF-1, IGFBP-3 and free IGF-1 levels by ELISA in growth hormone (GH) deficient children before and after GH replacement. (8/140)
Serum insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) levels reflect the growth hormone (GH) status. A few percent of IGF-1 circulate in a free form which is believed to represent the IGF biological activity. We retrospectively studied the changes of serum IGF-1, serum IGFBP-3, and plasma free IGF-1 levels in growth hormone deficient (GHD) children before and after treatment with recombinant human growth hormone (rhGH) for a period of 6 months and 1 year. Twenty-one GHD children (16 boys and 5 girls) who had the mean chronological and bone ages of 7.7 +/- 0.7 and 4.8 +/- 0.6 years, respectively, were treated with a mean rhGH dose of 11.66 +/- 0.42 U/m2 body surface area/week. Serum IGF-1 level increased from 162.5 +/- 42.9 ng/ml before treatment to 252.8 +/- 49.5 ng/ml (p = 0.007) and 282.7 +/- 86.9 ng/ml after treatment for 6 months and 1 year, respectively. Plasma free IGF-1 also increased from 0.38 +/- 0.30 ng/ml before treatment to 1.21 +/- 0.30 (p = 0.001) and 1.17 +/- 0.42 ng/ml after 6 months and 1 year of treatment. However, serum IGFBP-3 did not significantly increase after treatment. In addition, the free/total IGF-1 ratio decreased after treatment with rhGH. The height velocities at 6 months and 1 year after treatment were negatively correlated with plasma free IGF-1 before treatment. In conclusion, therefore, plasma free IGF-1 levels could serve as a good predictor of growth hormone responses. Furthermore, their circulating levels would be modified by serum IGF-1 status, and possibly, IGFBP-3 protease activity. (+info)Dwarfism is a medical condition that is characterized by short stature, typically with an adult height of 4 feet 10 inches (147 centimeters) or less. It is caused by a variety of genetic and medical conditions that affect bone growth, including skeletal dysplasias, hormonal deficiencies, and chromosomal abnormalities.
Skeletal dysplasias are the most common cause of dwarfism and are characterized by abnormalities in the development and growth of bones and cartilage. Achondroplasia is the most common form of skeletal dysplasia, accounting for about 70% of all cases of dwarfism. It is caused by a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene and results in short limbs, a large head, and a prominent forehead.
Hormonal deficiencies, such as growth hormone deficiency or hypothyroidism, can also cause dwarfism if they are not diagnosed and treated early. Chromosomal abnormalities, such as Turner syndrome (monosomy X) or Down syndrome (trisomy 21), can also result in short stature and other features of dwarfism.
It is important to note that people with dwarfism are not "dwarves" - the term "dwarf" is a medical and sociological term used to describe individuals with this condition, while "dwarves" is a term often used in fantasy literature and media to refer to mythical beings. The use of the term "dwarf" can be considered disrespectful or offensive to some people with dwarfism, so it is important to use respectful language when referring to individuals with this condition.
The pituitary gland is a small, endocrine gland located at the base of the brain, in the sella turcica of the sphenoid bone. It is often called the "master gland" because it controls other glands and makes the hormones that trigger many body functions. The pituitary gland measures about 0.5 cm in height and 1 cm in width, and it weighs approximately 0.5 grams.
The pituitary gland is divided into two main parts: the anterior lobe (adenohypophysis) and the posterior lobe (neurohypophysis). The anterior lobe is further divided into three zones: the pars distalis, pars intermedia, and pars tuberalis. Each part of the pituitary gland has distinct functions and produces different hormones.
The anterior pituitary gland produces and releases several important hormones, including:
* Growth hormone (GH), which regulates growth and development in children and helps maintain muscle mass and bone strength in adults.
* Thyroid-stimulating hormone (TSH), which controls the production of thyroid hormones by the thyroid gland.
* Adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol and other steroid hormones.
* Follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate reproductive function in both males and females.
* Prolactin, which stimulates milk production in pregnant and lactating women.
The posterior pituitary gland stores and releases two hormones that are produced by the hypothalamus:
* Antidiuretic hormone (ADH), which helps regulate water balance in the body by controlling urine production.
* Oxytocin, which stimulates uterine contractions during childbirth and milk release during breastfeeding.
Overall, the pituitary gland plays a critical role in maintaining homeostasis and regulating various bodily functions, including growth, development, metabolism, and reproductive function.
Pituitary neoplasms refer to abnormal growths or tumors in the pituitary gland, a small endocrine gland located at the base of the brain. These neoplasms can be benign (non-cancerous) or malignant (cancerous), with most being benign. They can vary in size and may cause various symptoms depending on their location, size, and hormonal activity.
Pituitary neoplasms can produce and secrete excess hormones, leading to a variety of endocrine disorders such as Cushing's disease (caused by excessive ACTH production), acromegaly (caused by excessive GH production), or prolactinoma (caused by excessive PRL production). They can also cause local compression symptoms due to their size, leading to headaches, vision problems, and cranial nerve palsies.
The exact causes of pituitary neoplasms are not fully understood, but genetic factors, radiation exposure, and certain inherited conditions may increase the risk of developing these tumors. Treatment options for pituitary neoplasms include surgical removal, radiation therapy, and medical management with drugs that can help control hormonal imbalances.
The anterior pituitary, also known as the adenohypophysis, is the front portion of the pituitary gland. It is responsible for producing and secreting several important hormones that regulate various bodily functions. These hormones include:
* Growth hormone (GH), which stimulates growth and cell reproduction in bones and other tissues.
* Thyroid-stimulating hormone (TSH), which regulates the production of thyroid hormones by the thyroid gland.
* Adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol and other steroid hormones.
* Follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate reproductive function in both males and females by controlling the development and release of eggs or sperm.
* Prolactin, which stimulates milk production in pregnant and nursing women.
* Melanocyte-stimulating hormone (MSH), which regulates skin pigmentation and appetite.
The anterior pituitary gland is controlled by the hypothalamus, a small region of the brain located just above it. The hypothalamus produces releasing and inhibiting hormones that regulate the secretion of hormones from the anterior pituitary. These hormones are released into a network of blood vessels called the portal system, which carries them directly to the anterior pituitary gland.
Damage or disease of the anterior pituitary can lead to hormonal imbalances and various medical conditions, such as growth disorders, thyroid dysfunction, adrenal insufficiency, reproductive problems, and diabetes insipidus.
Pituitary diseases refer to a group of conditions that affect the pituitary gland, a small endocrine gland located at the base of the brain. The pituitary gland is responsible for producing and secreting several important hormones that regulate various bodily functions, including growth and development, metabolism, stress response, and reproduction.
Pituitary diseases can be classified into two main categories:
1. Pituitary tumors: These are abnormal growths in or around the pituitary gland that can affect its function. Pituitary tumors can be benign (non-cancerous) or malignant (cancerous), and they can vary in size. Some pituitary tumors produce excess hormones, leading to a variety of symptoms, while others may not produce any hormones but can still cause problems by compressing nearby structures in the brain.
2. Pituitary gland dysfunction: This refers to conditions that affect the normal function of the pituitary gland without the presence of a tumor. Examples include hypopituitarism, which is a condition characterized by decreased production of one or more pituitary hormones, and Sheehan's syndrome, which occurs when the pituitary gland is damaged due to severe blood loss during childbirth.
Symptoms of pituitary diseases can vary widely depending on the specific condition and the hormones that are affected. Treatment options may include surgery, radiation therapy, medication, or a combination of these approaches.
Achondroplasia is a genetic disorder that affects bone growth, leading to dwarfism. It is the most common form of short-limbed dwarfism and is caused by a mutation in the FGFR3 gene. This mutation results in impaired endochondral ossification, which is the process by which cartilage is converted into bone.
People with achondroplasia have a characteristic appearance, including:
* Short stature (typically less than 4 feet, 4 inches tall)
* Disproportionately short arms and legs
* Large head with a prominent forehead and flat nasal bridge
* Short fingers with a gap between the middle and ring fingers (known as a trident hand)
* Bowing of the lower legs
* A swayed back (lordosis)
Achondroplasia is usually inherited in an autosomal dominant manner, which means that a child has a 50% chance of inheriting the disorder if one parent has it. However, about 80% of cases result from new mutations in the FGFR3 gene and occur in people with no family history of the condition.
While achondroplasia can cause various medical issues, such as breathing difficulties, ear infections, and spinal cord compression, most individuals with this condition have normal intelligence and a typical lifespan. Treatment typically focuses on managing specific symptoms and addressing any related complications.
Pituitary hormones are chemical messengers produced and released by the pituitary gland, a small endocrine gland located at the base of the brain. The pituitary gland is often referred to as the "master gland" because it controls several other endocrine glands and regulates various bodily functions.
There are two main types of pituitary hormones: anterior pituitary hormones and posterior pituitary hormones, which are produced in different parts of the pituitary gland and have distinct functions.
Anterior pituitary hormones include:
1. Growth hormone (GH): regulates growth and metabolism.
2. Thyroid-stimulating hormone (TSH): stimulates the thyroid gland to produce thyroid hormones.
3. Adrenocorticotropic hormone (ACTH): stimulates the adrenal glands to produce cortisol and other steroid hormones.
4. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH): regulate reproductive function in both males and females.
5. Prolactin: stimulates milk production in lactating women.
6. Melanocyte-stimulating hormone (MSH): regulates skin pigmentation and appetite.
Posterior pituitary hormones include:
1. Oxytocin: stimulates uterine contractions during childbirth and milk ejection during lactation.
2. Vasopressin (antidiuretic hormone, ADH): regulates water balance in the body by controlling urine production in the kidneys.
Overall, pituitary hormones play crucial roles in regulating growth, development, metabolism, reproductive function, and various other bodily functions. Abnormalities in pituitary hormone levels can lead to a range of medical conditions, such as dwarfism, acromegaly, Cushing's disease, infertility, and diabetes insipidus.
Pituitary apoplexy is a medical emergency that involves bleeding into the pituitary gland (a small gland at the base of the brain) and/or sudden swelling of the pituitary gland. This can lead to compression of nearby structures, such as the optic nerves and the hypothalamus, causing symptoms like severe headache, visual disturbances, hormonal imbalances, and altered mental status. It is often associated with a pre-existing pituitary tumor (such as a pituitary adenoma), but can also occur in individuals without any known pituitary abnormalities. Immediate medical attention is required to manage this condition, which may include surgical intervention, hormone replacement therapy, and supportive care.
Osteochondrodysplasias are a group of genetic disorders that affect the development of bones and cartilage. These conditions can result in dwarfism or short stature, as well as other skeletal abnormalities. Osteochondrodysplasias can be caused by mutations in genes that regulate bone and cartilage growth, and they are often characterized by abnormalities in the shape, size, and/or structure of the bones and cartilage.
There are many different types of osteochondrodysplasias, each with its own specific symptoms and patterns of inheritance. Some common examples include achondroplasia, thanatophoric dysplasia, and spondyloepiphyseal dysplasia. These conditions can vary in severity, and some may be associated with other health problems, such as respiratory difficulties or neurological issues.
Treatment for osteochondrodysplasias typically focuses on managing the symptoms and addressing any related health concerns. This may involve physical therapy, bracing or surgery to correct skeletal abnormalities, and treatment for any associated medical conditions. In some cases, genetic counseling may also be recommended for individuals with osteochondrodysplasias and their families.
Growth Hormone (GH), also known as somatotropin, is a peptide hormone secreted by the somatotroph cells in the anterior pituitary gland. It plays a crucial role in regulating growth, cell reproduction, and regeneration by stimulating the production of another hormone called insulin-like growth factor 1 (IGF-1) in the liver and other tissues. GH also has important metabolic functions, such as increasing glucose levels, enhancing protein synthesis, and reducing fat storage. Its secretion is regulated by two hypothalamic hormones: growth hormone-releasing hormone (GHRH), which stimulates its release, and somatostatin (SRIF), which inhibits its release. Abnormal levels of GH can lead to various medical conditions, such as dwarfism or gigantism if there are deficiencies or excesses, respectively.
Anterior pituitary hormones are a group of six major hormones that are produced and released by the anterior portion (lobe) of the pituitary gland, a small endocrine gland located at the base of the brain. These hormones play crucial roles in regulating various bodily functions and activities. The six main anterior pituitary hormones are:
1. Growth Hormone (GH): Also known as somatotropin, GH is essential for normal growth and development in children and adolescents. It helps regulate body composition, metabolism, and bone density in adults.
2. Prolactin (PRL): A hormone that stimulates milk production in females after childbirth and is also involved in various reproductive and immune functions in both sexes.
3. Follicle-Stimulating Hormone (FSH): FSH regulates the development, growth, and maturation of follicles in the ovaries (in females) and sperm production in the testes (in males).
4. Luteinizing Hormone (LH): LH plays a key role in triggering ovulation in females and stimulating testosterone production in males.
5. Thyroid-Stimulating Hormone (TSH): TSH regulates the function of the thyroid gland, which is responsible for producing and releasing thyroid hormones that control metabolism and growth.
6. Adrenocorticotropic Hormone (ACTH): ACTH stimulates the adrenal glands to produce cortisol, a steroid hormone involved in stress response, metabolism, and immune function.
These anterior pituitary hormones are regulated by the hypothalamus, which is located above the pituitary gland. The hypothalamus releases releasing and inhibiting factors that control the synthesis and secretion of anterior pituitary hormones, creating a complex feedback system to maintain homeostasis in the body.
Microcephaly is a medical condition where an individual has a smaller than average head size. The circumference of the head is significantly below the normal range for age and sex. This condition is typically caused by abnormal brain development, which can be due to genetic factors or environmental influences such as infections or exposure to harmful substances during pregnancy.
Microcephaly can be present at birth (congenital) or develop in the first few years of life. People with microcephaly often have intellectual disabilities, delayed development, and other neurological problems. However, the severity of these issues can vary widely, ranging from mild to severe. It is important to note that not all individuals with microcephaly will experience significant impairments or challenges.
Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) is a neuropeptide that belongs to the vasoactive intestinal polypeptide (VIP)/secretin/glucagon family. It was first isolated from the ovine hypothalamus and later found in various tissues and organs throughout the body, including the brain, pituitary gland, and peripheral nerves.
PACAP exists in two forms, PACAP-38 and PACAP-27, which differ in their length but share the same amino acid sequence at the N-terminus. PACAP exerts its effects through specific G protein-coupled receptors, including PAC1, VPAC1, and VPAC2 receptors, which are widely distributed throughout the body.
PACAP has a wide range of biological activities, including neurotrophic, neuroprotective, vasodilatory, and immunomodulatory effects. In the pituitary gland, PACAP stimulates adenylate cyclase activity, leading to an increase in intracellular cAMP levels, which in turn regulates the release of various hormones, including growth hormone, prolactin, and thyroid-stimulating hormone.
Overall, PACAP is a crucial neuropeptide involved in various physiological processes, and its dysregulation has been implicated in several pathological conditions, such as neurodegenerative diseases, mood disorders, and cancer.
The posterior pituitary gland, also known as the neurohypophysis, is the posterior portion of the pituitary gland. It is primarily composed of nerve fibers that originate from the hypothalamus, a region of the brain. These nerve fibers release two important hormones: oxytocin and vasopressin (also known as antidiuretic hormone or ADH).
Oxytocin plays a role in social bonding, sexual reproduction, and childbirth. During childbirth, it stimulates uterine contractions to help facilitate delivery, and after birth, it helps to trigger the release of milk from the mother's breasts during breastfeeding.
Vasopressin, on the other hand, helps regulate water balance in the body by controlling the amount of water that is excreted by the kidneys. It does this by increasing the reabsorption of water in the collecting ducts of the kidney, which leads to a more concentrated urine and helps prevent dehydration.
Overall, the posterior pituitary gland plays a critical role in maintaining fluid balance, social bonding, and reproduction.
Fibroblast Growth Factor Receptor 3 (FGFR3) is a type of cell surface receptor that binds to fibroblast growth factors (FGFs), which are signaling proteins involved in various biological processes such as cell division, growth, and wound healing.
FGFR3 is a transmembrane protein with an extracellular domain that contains the binding site for FGFs, a transmembrane domain, and an intracellular tyrosine kinase domain that activates downstream signaling pathways upon FGF binding.
Mutations in the FGFR3 gene have been associated with several human genetic disorders, including thanatophoric dysplasia, achondroplasia, and hypochondroplasia, which are characterized by abnormal bone growth and development. In these conditions, gain-of-function mutations in FGFR3 lead to increased receptor activity and activation of downstream signaling pathways, resulting in impaired endochondral ossification and short-limbed dwarfism.
In addition to its role in bone growth and development, FGFR3 has been implicated in the regulation of cell proliferation, differentiation, and survival in various tissues, including the brain, lung, and kidney. Dysregulation of FGFR3 signaling has also been associated with cancer, including bladder, breast, and cervical cancers.
An adenoma is a benign (noncancerous) tumor that develops from glandular epithelial cells. These types of cells are responsible for producing and releasing fluids, such as hormones or digestive enzymes, into the surrounding tissues. Adenomas can occur in various organs and glands throughout the body, including the thyroid, pituitary, adrenal, and digestive systems.
Depending on their location, adenomas may cause different symptoms or remain asymptomatic. Some common examples of adenomas include:
1. Colorectal adenoma (also known as a polyp): These growths occur in the lining of the colon or rectum and can develop into colorectal cancer if left untreated. Regular screenings, such as colonoscopies, are essential for early detection and removal of these polyps.
2. Thyroid adenoma: This type of adenoma affects the thyroid gland and may result in an overproduction or underproduction of hormones, leading to conditions like hyperthyroidism (overactive thyroid) or hypothyroidism (underactive thyroid).
3. Pituitary adenoma: These growths occur in the pituitary gland, which is located at the base of the brain and controls various hormonal functions. Depending on their size and location, pituitary adenomas can cause vision problems, headaches, or hormonal imbalances that affect growth, reproduction, and metabolism.
4. Liver adenoma: These rare benign tumors develop in the liver and may not cause any symptoms unless they become large enough to press on surrounding organs or structures. In some cases, liver adenomas can rupture and cause internal bleeding.
5. Adrenal adenoma: These growths occur in the adrenal glands, which are located above the kidneys and produce hormones that regulate stress responses, metabolism, and blood pressure. Most adrenal adenomas are nonfunctioning, meaning they do not secrete excess hormones. However, functioning adrenal adenomas can lead to conditions like Cushing's syndrome or Conn's syndrome, depending on the type of hormone being overproduced.
It is essential to monitor and manage benign tumors like adenomas to prevent potential complications, such as rupture, bleeding, or hormonal imbalances. Treatment options may include surveillance with imaging studies, medication to manage hormonal issues, or surgical removal of the tumor in certain cases.
Prolactin is a hormone produced by the pituitary gland, a small gland located at the base of the brain. Its primary function is to stimulate milk production in women after childbirth, a process known as lactation. However, prolactin also plays other roles in the body, including regulating immune responses, metabolism, and behavior. In men, prolactin helps maintain the sexual glands and contributes to paternal behaviors.
Prolactin levels are usually low in both men and non-pregnant women but increase significantly during pregnancy and after childbirth. Various factors can affect prolactin levels, including stress, sleep, exercise, and certain medications. High prolactin levels can lead to medical conditions such as amenorrhea (absence of menstruation), galactorrhea (spontaneous milk production not related to childbirth), infertility, and reduced sexual desire in both men and women.
Developmental bone diseases are a group of medical conditions that affect the growth and development of bones. These diseases are present at birth or develop during childhood and adolescence, when bones are growing rapidly. They can result from genetic mutations, hormonal imbalances, or environmental factors such as poor nutrition.
Some examples of developmental bone diseases include:
1. Osteogenesis imperfecta (OI): Also known as brittle bone disease, OI is a genetic disorder that affects the body's production of collagen, a protein necessary for healthy bones. People with OI have fragile bones that break easily and may also experience other symptoms such as blue sclerae (whites of the eyes), hearing loss, and joint laxity.
2. Achondroplasia: This is the most common form of dwarfism, caused by a genetic mutation that affects bone growth. People with achondroplasia have short limbs and a large head relative to their body size.
3. Rickets: A condition caused by vitamin D deficiency or an inability to absorb or use vitamin D properly. This leads to weak, soft bones that can bow or bend easily, particularly in children.
4. Fibrous dysplasia: A rare bone disorder where normal bone is replaced with fibrous tissue, leading to weakened bones and deformities.
5. Scoliosis: An abnormal curvature of the spine that can develop during childhood or adolescence. While not strictly a developmental bone disease, scoliosis can be caused by various underlying conditions such as cerebral palsy, muscular dystrophy, or spina bifida.
Treatment for developmental bone diseases varies depending on the specific condition and its severity. Treatment may include medication, physical therapy, bracing, or surgery to correct deformities and improve function. Regular follow-up with a healthcare provider is essential to monitor growth, manage symptoms, and prevent complications.
Pituitary function tests are a group of diagnostic exams that evaluate the proper functioning of the pituitary gland, a small endocrine gland located at the base of the brain. The pituitary gland is responsible for producing and releasing several essential hormones that regulate various bodily functions, including growth, metabolism, stress response, reproduction, and lactation.
These tests typically involve measuring the levels of different hormones in the blood, stimulating or suppressing the pituitary gland with specific medications, and assessing the body's response to these challenges. Some common pituitary function tests include:
1. Growth hormone (GH) testing: Measures GH levels in the blood, often after a provocative test using substances like insulin, arginine, clonidine, or glucagon to stimulate GH release.
2. Thyroid-stimulating hormone (TSH) and free thyroxine (FT4) testing: Assesses the function of the thyroid gland by measuring TSH and FT4 levels in response to TRH (thyrotropin-releasing hormone) stimulation.
3. Adrenocorticotropic hormone (ACTH) and cortisol testing: Evaluates the hypothalamic-pituitary-adrenal axis by measuring ACTH and cortisol levels after a CRH (corticotropin-releasing hormone) stimulation test or an insulin tolerance test.
4. Prolactin (PRL) testing: Measures PRL levels in the blood, which can be elevated due to pituitary tumors or other conditions affecting the hypothalamus.
5. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) testing: Assesses reproductive function by measuring FSH and LH levels, often in conjunction with estradiol or testosterone levels.
6. Gonadotropin-releasing hormone (GnRH) stimulation test: Evaluates gonadal function by measuring FSH and LH levels after GnRH administration.
7. Growth hormone (GH) testing: Measures GH levels in response to various stimuli, such as insulin-like growth factor-1 (IGF-1), glucagon, or arginine.
8. Vasopressin (ADH) testing: Assesses the posterior pituitary function by measuring ADH levels and performing a water deprivation test.
These tests can help diagnose various pituitary disorders, such as hypopituitarism, hyperpituitarism, or pituitary tumors, and guide appropriate treatment strategies.
A prolactinoma is a type of pituitary tumor that produces an excess amount of the hormone prolactin, leading to various symptoms. The pituitary gland, located at the base of the brain, is responsible for producing and releasing several hormones that regulate different bodily functions. Prolactin is one such hormone, primarily known for its role in stimulating milk production in women during lactation (breastfeeding).
Prolactinoma tumors can be classified into two types: microprolactinomas and macroprolactinomas. Microprolactinomas are smaller tumors, typically less than 10 millimeters in size, while macroprolactinomas are larger tumors, generally greater than 10 millimeters in size.
The overproduction of prolactin caused by these tumors can lead to several clinical manifestations, including:
1. Galactorrhea: Unusual and often spontaneous milk production or leakage from the nipples, which can occur in both men and women who do not have a recent history of pregnancy or breastfeeding.
2. Menstrual irregularities: In women, high prolactin levels can interfere with the normal functioning of other hormones, leading to menstrual irregularities such as infrequent periods (oligomenorrhea) or absent periods (amenorrhea), and sometimes infertility.
3. Sexual dysfunction: In both men and women, high prolactin levels can cause decreased libido and sexual desire. Men may also experience erectile dysfunction and reduced sperm production.
4. Bone loss: Over time, high prolactin levels can lead to decreased bone density and an increased risk of osteoporosis due to the disruption of other hormones that regulate bone health.
5. Headaches and visual disturbances: As the tumor grows, it may put pressure on surrounding structures in the brain, leading to headaches and potential vision problems such as blurred vision or decreased peripheral vision.
Diagnosis typically involves measuring prolactin levels in the blood and performing imaging tests like an MRI (magnetic resonance imaging) scan to assess the size of the tumor. Treatment usually consists of medication to lower prolactin levels, such as dopamine agonists (e.g., bromocriptine or cabergoline), which can also help shrink the tumor. In some cases, surgery may be necessary if medication is ineffective or if the tumor is large and causing severe symptoms.
Gonadotropins are hormones produced and released by the anterior pituitary gland, a small endocrine gland located at the base of the brain. These hormones play crucial roles in regulating reproduction and sexual development. There are two main types of gonadotropins:
1. Follicle-Stimulating Hormone (FSH): FSH is essential for the growth and development of follicles in the ovaries (in females) or sperm production in the testes (in males). In females, FSH stimulates the maturation of eggs within the follicles.
2. Luteinizing Hormone (LH): LH triggers ovulation in females, causing the release of a mature egg from the dominant follicle. In males, LH stimulates the production and secretion of testosterone in the testes.
Together, FSH and LH work synergistically to regulate various aspects of reproductive function and sexual development. Their secretion is controlled by the hypothalamus, which releases gonadotropin-releasing hormone (GnRH) to stimulate the production and release of FSH and LH from the anterior pituitary gland.
Abnormal levels of gonadotropins can lead to various reproductive disorders, such as infertility or menstrual irregularities in females and issues related to sexual development or function in both sexes. In some cases, synthetic forms of gonadotropins may be used clinically to treat these conditions or for assisted reproductive technologies (ART).
Thnanatophoric Dysplasia is a severe skeletal disorder characterized by extreme short limbs, a narrow chest, and large head. It is one of the most common types of short-limbed dwarfism. The name "thanatophoric" comes from the Greek word thanatos, meaning death, as this condition is often lethal in the newborn period or shortly thereafter due to respiratory distress.
The disorder is caused by mutations in the FGFR3 gene, which provides instructions for making a protein that is part of a group of proteins called fibroblast growth factor receptors. These receptors play critical roles in many important processes during embryonic development, such as controlling bone growth.
There are two major types of thanatophoric dysplasia: type I and type II. Type I is characterized by curved thigh bones (femurs) and a clover-leaf shaped skull. Type II is characterized by straight femurs and an unossified (not fully developed) vertebral column.
The diagnosis of thanatophoric dysplasia can be made prenatally through ultrasound examination or postnatally through physical examination, X-rays, and genetic testing. Unfortunately, due to the severity of the condition, there is no cure for thanatophoric dysplasia and management is supportive in nature, focusing on providing comfort and addressing any complications that may arise.
A Growth Hormone-Secreting Pituitary Adenoma (GH-secreting pituitary adenoma, or GHoma) is a type of benign tumor that develops in the pituitary gland and results in excessive production of growth hormone (GH). This leads to a condition known as acromegaly if it occurs in adults, or gigantism if it occurs in children before the closure of the growth plates.
Symptoms of GH-secreting pituitary adenoma may include:
1. Coarsening of facial features
2. Enlargement of hands and feet
3. Deepened voice due to thickening of vocal cords
4. Increased sweating and body odor
5. Joint pain and stiffness
6. Sleep apnea
7. Fatigue, weakness, or muscle wasting
8. Headaches
9. Vision problems
10. Irregular menstrual periods in women
11. Erectile dysfunction in men
Diagnosis typically involves measuring the levels of GH and insulin-like growth factor 1 (IGF-1) in the blood, along with imaging tests like MRI or CT scans to locate and characterize the tumor. Treatment options include surgical removal of the tumor, radiation therapy, and medication to control GH production. Regular follow-ups are necessary to monitor for potential recurrence.
A growth plate, also known as an epiphyseal plate or physis, is a layer of cartilaginous tissue found near the ends of long bones in children and adolescents. This region is responsible for the longitudinal growth of bones during development. The growth plate contains actively dividing cells that differentiate into chondrocytes, which produce and deposit new matrix, leading to bone elongation. Once growth is complete, usually in late adolescence or early adulthood, the growth plates ossify (harden) and are replaced by solid bone, transforming into the epiphyseal line.
Pituitary dwarfism, also known as growth hormone deficiency dwarfism or hypopituitarism dwarfism, is a type of dwarfism that results from insufficient production of growth hormone by the pituitary gland during childhood. The medical term for this condition is "growth hormone deficiency."
The pituitary gland is a small gland located at the base of the brain that produces several important hormones, including growth hormone. Growth hormone plays a critical role in regulating growth and development during childhood and adolescence. When the pituitary gland fails to produce enough growth hormone, children do not grow and develop normally, resulting in short stature and other symptoms associated with dwarfism.
Pituitary dwarfism can be caused by a variety of factors, including genetic mutations, brain tumors, trauma, or infection. In some cases, the cause may be unknown. Symptoms of pituitary dwarfism include short stature, delayed puberty, and other hormonal imbalances.
Treatment for pituitary dwarfism typically involves replacing the missing growth hormone with injections of synthetic growth hormone. This therapy can help promote normal growth and development, although it may not completely eliminate the short stature associated with the condition. Early diagnosis and treatment are essential to optimize outcomes and improve quality of life for individuals with pituitary dwarfism.
Hypopituitarism is a medical condition characterized by deficient secretion of one or more hormones produced by the pituitary gland, a small endocrine gland located at the base of the brain. The pituitary gland controls several other endocrine glands in the body, including the thyroid, adrenals, and sex glands (ovaries and testes).
Hypopituitarism can result from damage to the pituitary gland due to various causes such as tumors, surgery, radiation therapy, trauma, or inflammation. In some cases, hypopituitarism may also be caused by a dysfunction of the hypothalamus, a region in the brain that regulates the pituitary gland's function.
The symptoms and signs of hypopituitarism depend on which hormones are deficient and can include fatigue, weakness, decreased appetite, weight loss, low blood pressure, decreased sex drive, infertility, irregular menstrual periods, intolerance to cold, constipation, thinning hair, dry skin, and depression.
Treatment of hypopituitarism typically involves hormone replacement therapy to restore the deficient hormones' normal levels. The type and dosage of hormones used will depend on which hormones are deficient and may require regular monitoring and adjustments over time.
Pituitary ACTH hypersecretion, also known as Cushing's disease, is a condition characterized by the excessive production of adrenocorticotropic hormone (ACTH) from the pituitary gland. This results in an overproduction of cortisol, a steroid hormone produced by the adrenal glands, leading to a constellation of symptoms known as Cushing's syndrome.
In Cushing's disease, a benign tumor called an adenoma develops on the pituitary gland, causing it to release excess ACTH. This in turn stimulates the adrenal glands to produce more cortisol than necessary. The resulting high levels of cortisol can cause various symptoms such as weight gain, particularly around the trunk and face (central obesity), thinning of the skin, bruising, weakness, fatigue, mood changes, high blood pressure, and an increased risk of infections.
It is important to distinguish Cushing's disease from other causes of Cushing's syndrome, such as cortisol-producing adrenal tumors or exogenous sources of corticosteroid use, as the treatment approach may differ. Treatment for Cushing's disease typically involves surgical removal of the pituitary tumor, with additional medical management and/or radiation therapy in some cases.
Adrenocorticotropic Hormone (ACTH) is a hormone produced and released by the anterior pituitary gland, a small endocrine gland located at the base of the brain. ACTH plays a crucial role in the regulation of the body's stress response and has significant effects on various physiological processes.
The primary function of ACTH is to stimulate the adrenal glands, which are triangular-shaped glands situated on top of the kidneys. The adrenal glands consist of two parts: the outer cortex and the inner medulla. ACTH specifically targets the adrenal cortex, where it binds to specific receptors and initiates a series of biochemical reactions leading to the production and release of steroid hormones, primarily cortisol (a glucocorticoid) and aldosterone (a mineralocorticoid).
Cortisol is involved in various metabolic processes, such as regulating blood sugar levels, modulating the immune response, and helping the body respond to stress. Aldosterone plays a vital role in maintaining electrolyte and fluid balance by promoting sodium reabsorption and potassium excretion in the kidneys.
ACTH release is controlled by the hypothalamus, another part of the brain, which produces corticotropin-releasing hormone (CRH). CRH stimulates the anterior pituitary gland to secrete ACTH, which in turn triggers cortisol production in the adrenal glands. This complex feedback system helps maintain homeostasis and ensures that appropriate amounts of cortisol are released in response to various physiological and psychological stressors.
Disorders related to ACTH can lead to hormonal imbalances, resulting in conditions such as Cushing's syndrome (excessive cortisol production) or Addison's disease (insufficient cortisol production). Proper diagnosis and management of these disorders typically involve assessing the function of the hypothalamic-pituitary-adrenal axis and addressing any underlying issues affecting ACTH secretion.
An ACTH-secreting pituitary adenoma is a type of tumor that develops in the pituitary gland, a small gland located at the base of the brain. This type of tumor is also known as Cushing's disease.
ACTH stands for adrenocorticotropic hormone, which is a hormone produced and released by the pituitary gland. ACTH stimulates the adrenal glands (small glands located on top of the kidneys) to produce cortisol, a steroid hormone that helps regulate metabolism, helps the body respond to stress, and suppresses inflammation.
In an ACTH-secreting pituitary adenoma, the tumor cells produce and release excessive amounts of ACTH, leading to overproduction of cortisol by the adrenal glands. This can result in a constellation of symptoms known as Cushing's syndrome, which may include weight gain (especially around the trunk), fatigue, muscle weakness, mood changes, thinning of the skin, easy bruising, and increased susceptibility to infections.
Treatment for an ACTH-secreting pituitary adenoma typically involves surgical removal of the tumor, followed by medications to manage cortisol levels if necessary. Radiation therapy may also be used in some cases.
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.
Growth Hormone-Releasing Hormone (GHRH) is a hormone that is produced and released by the hypothalamus, a small gland located in the brain. Its primary function is to stimulate the anterior pituitary gland to release growth hormone (GH) into the bloodstream. GH plays a crucial role in growth and development, particularly during childhood and adolescence, by promoting the growth of bones and muscles.
GHRH is a 44-amino acid peptide that binds to specific receptors on the surface of pituitary cells, triggering a series of intracellular signals that ultimately lead to the release of GH. The production and release of GHRH are regulated by various factors, including sleep, stress, exercise, and nutrition.
Abnormalities in the production or function of GHRH can lead to growth disorders, such as dwarfism or gigantism, as well as other hormonal imbalances. Therefore, understanding the role of GHRH in regulating GH release is essential for diagnosing and treating these conditions.
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.
Micrognathism is a medical term that refers to a condition where the lower jaw (mandible) is abnormally small or underdeveloped. This can result in various dental and skeletal problems, including an improper bite (malocclusion), difficulty speaking, chewing, or swallowing, and sleep apnea. Micrognathism may be congenital or acquired later in life due to trauma, disease, or surgical removal of part of the jaw. Treatment options depend on the severity of the condition and can include orthodontic treatment, surgery, or a combination of both.
Bone development, also known as ossification, is the process by which bone tissue is formed and grows. This complex process involves several different types of cells, including osteoblasts, which produce new bone matrix, and osteoclasts, which break down and resorb existing bone tissue.
There are two main types of bone development: intramembranous and endochondral ossification. Intramembranous ossification occurs when bone tissue forms directly from connective tissue, while endochondral ossification involves the formation of a cartilage model that is later replaced by bone.
During fetal development, most bones develop through endochondral ossification, starting as a cartilage template that is gradually replaced by bone tissue. However, some bones, such as those in the skull and clavicles, develop through intramembranous ossification.
Bone development continues after birth, with new bone tissue being laid down and existing tissue being remodeled throughout life. This ongoing process helps to maintain the strength and integrity of the skeleton, allowing it to adapt to changing mechanical forces and repair any damage that may occur.
Thyrotropin-Releasing Hormone (TRH) is a tripeptide hormone that is produced and released by the hypothalamus in the brain. Its main function is to regulate the release of thyroid-stimulating hormone (TSH) from the anterior pituitary gland. TRH acts on the pituitary gland to stimulate the synthesis and secretion of TSH, which then stimulates the thyroid gland to produce and release thyroid hormones (triiodothyronine (T3) and thyroxine (T4)) into the bloodstream.
TRH is a tripeptide amino acid sequence with the structure of pGlu-His-Pro-NH2, and it is synthesized as a larger precursor molecule called preprothyrotropin-releasing hormone (preproTRH) in the hypothalamus. PreproTRH undergoes post-translational processing to produce TRH, which is then stored in secretory vesicles and released into the hypophyseal portal system, where it travels to the anterior pituitary gland and binds to TRH receptors on thyrotroph cells.
In addition to its role in regulating TSH release, TRH has been shown to have other physiological functions, including modulation of feeding behavior, body temperature, and neurotransmitter release. Dysregulation of the TRH-TSH axis can lead to various thyroid disorders, such as hypothyroidism or hyperthyroidism.
Cyclic guanosine monophosphate (cGMP)-dependent protein kinase type II (PKG II) is a subtype of cGMP-dependent protein kinases, which are enzymes that play a crucial role in the regulation of various cellular functions. PKG II is specifically expressed in certain tissues such as the smooth muscle and the brain.
The activation of PKG II occurs when cGMP binds to the regulatory subunit of the enzyme, leading to the release and activation of the catalytic subunit. Once activated, PKG II phosphorylates specific serine and threonine residues on target proteins, which in turn modulate their activity, localization, or stability.
PKG II has been implicated in several physiological processes, including smooth muscle relaxation, platelet aggregation, neuronal signaling, and cardiovascular function. Dysregulation of PKG II has been associated with various pathological conditions such as hypertension, pulmonary arterial hypertension, heart failure, and neurodegenerative disorders.
Gigantism is a rare medical condition characterized by excessive growth and height significantly above average. This occurs due to an overproduction of growth hormone (GH), also known as somatotropin, during the growth phase in childhood. The pituitary gland, a small gland located at the base of the brain, is responsible for producing this hormone.
In gigantism, the pituitary gland releases too much GH, leading to abnormal bone and tissue growth. This condition is different from acromegaly, which is characterized by excessive GH production in adulthood after the growth phase has ended. In both cases, the excess GH can lead to various health complications, including cardiovascular disease, diabetes, hypertension, and joint problems.
Gigantism is typically caused by a benign tumor called a pituitary adenoma that presses against and stimulates the production of GH from the anterior pituitary gland. Treatment usually involves surgical removal of the tumor or medication to control GH levels, depending on the severity and progression of the condition. Early diagnosis and treatment are crucial for managing the symptoms and preventing long-term health complications associated with gigantism.
Brassinosteroids are a class of steroid hormones found in plants that play crucial roles in various aspects of plant growth and development. They were first discovered in the 1970s and are named after Brassica napus, the rape seed plant from which they were initially isolated. These hormones are involved in regulating processes such as cell division, cell elongation, vascular differentiation, stress tolerance, and photomorphogenesis.
Brassinosteroids function by interacting with specific receptor proteins located on the plasma membrane of plant cells. This interaction triggers a series of intracellular signaling events that ultimately lead to changes in gene expression and various cellular responses. Defects in brassinosteroid biosynthesis or signaling can result in dwarfism, reduced fertility, and other developmental abnormalities in plants.
Some well-known brassinosteroids include brassinolide, castasterone, and typhasterol. These hormones are present in trace amounts in plants but have significant effects on plant growth and development. Brassinosteroids also exhibit various stress tolerance-promoting activities, such as enhancing resistance to drought, salinity, extreme temperatures, and pathogen attacks.
In summary, brassinosteroids are a class of steroid hormones that play essential roles in regulating plant growth, development, and stress responses. They interact with specific receptor proteins on the plasma membrane, triggering intracellular signaling events leading to changes in gene expression and various cellular responses.
Heterocyclic steroids refer to a class of steroidal compounds that contain one or more heteroatoms such as nitrogen, oxygen, or sulfur in their ring structure. These molecules are characterized by having at least one carbon atom in the ring replaced by a heteroatom, which can affect the chemical and physical properties of the compound compared to typical steroids.
Steroids are a type of organic compound that contains a characteristic arrangement of four fused rings, three of them six-membered (cyclohexane) and one five-membered (cyclopentane) ring. The heterocyclic steroids can have various biological activities, including hormonal, anti-inflammatory, and immunomodulatory effects. They are used in the pharmaceutical industry to develop drugs for treating several medical conditions, such as hormone replacement therapy, autoimmune disorders, and cancer.
Examples of heterocyclic steroids include cortisol (a natural glucocorticoid with a heterocyclic side chain), estradiol (a natural estrogen containing a phenolic A-ring), and various synthetic steroids like anabolic-androgenic steroids, which may contain heterocyclic structures to enhance their biological activity or pharmacokinetic properties.
Pituitary hormone-releasing hormones (PRHs), also known as hypothalamic releasing hormones or hypothalamic hormones, are small neuropeptides produced and released by the hypothalamus - a small region of the brain. These hormones play crucial roles in regulating the secretion and release of various pituitary hormones, which in turn control several essential bodily functions, including growth, development, metabolism, stress response, reproduction, and lactation.
There are several PRHs, each with a specific target pituitary hormone:
1. Thyrotropin-releasing hormone (TRH): Stimulates the release of thyroid-stimulating hormone (TSH) from the anterior pituitary gland, which then promotes the production and release of thyroid hormones.
2. Gonadotropin-releasing hormone (GnRH): Regulates the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary gland, which are essential for reproductive functions.
3. Corticotropin-releasing hormone (CRH): Stimulates the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary gland, which then promotes the production and release of cortisol and other glucocorticoids from the adrenal glands.
4. Growth hormone-releasing hormone (GHRH): Stimulates the release of growth hormone (GH) from the anterior pituitary gland, which is essential for growth, development, and metabolism regulation.
5. Somatostatin or growth hormone-inhibiting hormone (GHIH): Inhibits the release of GH from the anterior pituitary gland and also suppresses the secretion of thyroid hormones.
6. Prolactin-releasing hormone (PRH) or prolactin-releasing factor (PRF): Stimulates the release of prolactin from the anterior pituitary gland, which is essential for lactation and reproductive functions.
7. Prolactin-inhibiting hormone (PIH) or dopamine: Inhibits the release of prolactin from the anterior pituitary gland.
These releasing hormones and inhibitory hormones work together to maintain a delicate balance in various physiological processes, including growth, development, metabolism, stress response, and reproductive functions. Dysregulation of these hormonal systems can lead to various endocrine disorders and diseases.
Pituitary hormone receptors are specialized protein molecules found on the surface of target cells in various organs and tissues throughout the body. These receptors selectively bind to specific pituitary hormones, which are released from the pituitary gland, a small endocrine gland located at the base of the brain. The binding of the hormone to its corresponding receptor triggers a series of intracellular signaling events that ultimately lead to physiological responses in the target cells.
There are several types of pituitary hormones, each with its own unique receptors, including:
1. Growth Hormone (GH) Receptors: These receptors are found on many tissues, such as liver, muscle, and bone. The binding of GH to these receptors stimulates the production of insulin-like growth factor 1 (IGF-1), which promotes cell growth and division, as well as other metabolic processes.
2. Adrenocorticotropic Hormone (ACTH) Receptors: These receptors are primarily located on cells in the adrenal gland, particularly in the adrenal cortex. The binding of ACTH to these receptors stimulates the production and release of cortisol, a steroid hormone involved in stress response, metabolism, and immune function.
3. Thyroid-Stimulating Hormone (TSH) Receptors: These receptors are found on the surface of thyroid follicular cells. The binding of TSH to these receptors triggers the production and release of thyroid hormones, triiodothyronine (T3) and thyroxine (T4), which regulate metabolism, growth, and development.
4. Follicle-Stimulating Hormone (FSH) Receptors: These receptors are present in the gonads (ovaries and testes). In females, FSH binds to these receptors to stimulate follicular growth and estrogen production, while in males, it promotes spermatogenesis.
5. Luteinizing Hormone (LH) Receptors: These receptors are also found in the gonads. In females, LH binding triggers ovulation and progesterone production, while in males, it stimulates testosterone production and sperm maturation.
6. Prolactin (PRL) Receptors: These receptors are located in various tissues, including the mammary glands, liver, and brain. The binding of PRL to these receptors promotes lactation, growth, and differentiation of mammary cells, as well as modulating immune function and behavior.
7. Melanocyte-Stimulating Hormone (MSH) Receptors: These receptors are found in the skin and central nervous system. The binding of MSH to these receptors regulates pigmentation, appetite, and energy balance.
8. Growth Hormone-Releasing Hormone (GHRH) Receptors: These receptors are present in the pituitary gland. The binding of GHRH to these receptors stimulates the release of growth hormone, which promotes growth, cell reproduction, and regeneration.
9. Somatostatin Receptors (SST): These receptors are located in various tissues, including the pancreas, brain, and gastrointestinal tract. The binding of somatostatin to these receptors inhibits the release of several hormones, such as growth hormone, insulin, and glucagon.
10. Corticotropin-Releasing Hormone (CRH) Receptors: These receptors are found in the hypothalamus and other brain regions. The binding of CRH to these receptors stimulates the release of adrenocorticotropic hormone (ACTH), which regulates stress response, metabolism, and immune function.
11. Thyrotropin-Releasing Hormone (TRH) Receptors: These receptors are present in the hypothalamus and pituitary gland. The binding of TRH to these receptors stimulates the release of thyroid-stimulating hormone (TSH), which regulates thyroid function and metabolism.
12. Gonadotropin-Releasing Hormone (GnRH) Receptors: These receptors are located in the hypothalamus and pituitary gland. The binding of GnRH to these receptors stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate reproductive function.
13. Prolactin-Releasing Hormone (PRH) Receptors: These receptors are found in the hypothalamus and pituitary gland. The binding of PRH to these receptors stimulates the release of prolactin, which regulates lactation and other physiological processes.
14. Growth Hormone-Releasing Hormone (GHRH) Receptors: These receptors are located in the hypothalamus and pituitary gland. The binding of GHRH to these receptors stimulates the release of growth hormone, which regulates growth, metabolism, and other physiological processes.
15. Melanin-Concentrating Hormone (MCH) Receptors: These receptors are found in various brain regions and peripheral tissues. The binding of MCH to these receptors regulates energy balance, feeding behavior, and sleep-wake cycles.
16. Neuropeptide Y (NPY) Receptors: These receptors are located in various brain regions and peripheral tissues. The binding of NPY to these receptors regulates energy balance, feeding behavior, stress response, and cardiovascular function.
17. Corticotropin-Releasing Hormone (CRH) Receptors: These receptors are found in various brain regions and peripheral tissues. The binding of CRH to these receptors regulates the hypothalamic-pituitary-adrenal axis, stress response, and anxiety.
18. Oxytocin Receptors: These receptors are located in various brain regions and peripheral tissues. The binding of oxytocin to these receptors regulates social behavior, maternal care, and reproductive function.
19. Vasopressin Receptors: These receptors are found in various brain regions and peripheral tissues. The binding of vasopressin to these receptors regulates water balance, blood pressure, and social behavior.
20. Substance P Receptors (Neurokinin 1 Receptors): These receptors are located in various brain regions and peripheral tissues. The binding of substance P to these receptors regulates pain transmission, neuroinflammation, and stress response.
21. Melanocortin Receptors: These receptors are found in various brain regions and peripheral tissues. The binding of melanocortins to these receptors regulates energy balance, feeding behavior, and sexual function.
22. Endorphin Receptors (Mu, Delta, Kappa Opioid Receptors): These receptors are located in various brain regions and peripheral tissues. The binding of endorphins to these receptors modulates pain transmission, reward processing, and stress response.
23. Galanin Receptors: These receptors are found in various brain regions and peripheral tissues. The binding of galanin to these receptors regulates feeding behavior, anxiety, and nociception.
24. Somatostatin Receptors: These receptors are located in various brain regions and peripheral tissues. The binding of somatostatin to these receptors modulates neurotransmitter release, hormone secretion, and cell proliferation.
25. Neuropeptide Y Receptors: These receptors are found in various brain regions and peripheral tissues. The binding of neuropeptide Y to these receptors regulates feeding behavior, anxiety, and cardiovascular function.
26. Corticotropin-Releasing Hormone Receptors: These receptors are located in various brain regions and peripheral tissues. The binding of corticotropin-releasing hormone to these receptors modulates stress response, anxiety, and neuroinflammation.
27. Oxytocin Receptors: These receptors are found in various brain regions and peripheral tissues. The binding of oxytocin to these receptors regulates social behavior, maternal care, and anxiety.
28. Vasopressin Receptors: These receptors are located in various brain regions and peripheral tissues. The binding of vasopressin to these receptors modulates water balance, blood pressure, and social behavior.
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Somatotropin receptors are a type of cell surface receptor that binds to and gets activated by the hormone somatotropin, also known as growth hormone (GH). These receptors are found in many tissues throughout the body, including the liver, muscle, and fat. When somatotropin binds to its receptor, it activates a series of intracellular signaling pathways that regulate various physiological processes such as growth, metabolism, and cell reproduction.
Somatotropin receptors belong to the class I cytokine receptor family and are composed of two subunits, a homodimer of extracellular glycoproteins that bind to the hormone and an intracellular tyrosine kinase domain that activates downstream signaling pathways. Mutations in the somatotropin receptor gene can lead to growth disorders such as dwarfism or gigantism, depending on whether the mutation results in a decrease or increase in receptor activity.
Chondrodysplasia punctata is a group of genetic disorders that affect the development of bones and cartilage. The condition is characterized by stippled calcifications, or spots of calcium deposits, in the cartilage that can be seen on X-rays. These spots are typically found at the ends of long bones, in the sternum, and in the pelvis.
The symptoms of chondrodysplasia punctata can vary widely depending on the specific type of the disorder. Some people with the condition may have short stature, bowed legs, and other skeletal abnormalities, while others may have only mild symptoms or no symptoms at all. The condition can also be associated with developmental delays, intellectual disability, and other health problems.
There are several different types of chondrodysplasia punctata, each caused by a different genetic mutation. Some forms of the disorder are inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene (one from each parent) in order to develop the condition. Other forms of chondrodysplasia punctata are inherited in an X-linked dominant manner, meaning that a single copy of the mutated gene (on the X chromosome) is enough to cause the disorder in females. Males, who have only one X chromosome, will typically be more severely affected by X-linked dominant disorders.
There is no cure for chondrodysplasia punctata, and treatment is focused on managing the symptoms of the condition. This may include physical therapy, bracing or surgery to correct skeletal abnormalities, and medications to manage pain or other health problems.
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.
'Abnormalities, Multiple' is a broad term that refers to the presence of two or more structural or functional anomalies in an individual. These abnormalities can be present at birth (congenital) or can develop later in life (acquired). They can affect various organs and systems of the body and can vary greatly in severity and impact on a person's health and well-being.
Multiple abnormalities can occur due to genetic factors, environmental influences, or a combination of both. Chromosomal abnormalities, gene mutations, exposure to teratogens (substances that cause birth defects), and maternal infections during pregnancy are some of the common causes of multiple congenital abnormalities.
Examples of multiple congenital abnormalities include Down syndrome, Turner syndrome, and VATER/VACTERL association. Acquired multiple abnormalities can result from conditions such as trauma, infection, degenerative diseases, or cancer.
The medical evaluation and management of individuals with multiple abnormalities depend on the specific abnormalities present and their impact on the individual's health and functioning. A multidisciplinary team of healthcare professionals is often involved in the care of these individuals to address their complex needs.
A chromophobe adenoma is a type of benign (non-cancerous) tumor that typically arises in the pituitary gland, which is a small endocrine gland located at the base of the brain. The term "chromophobe" refers to the appearance of the cells under a microscope - they lack pigment and have a characteristic appearance with abundant clear or lightly stained cytoplasm.
Chromophobe adenomas are slow-growing tumors that can vary in size, and they may cause symptoms due to pressure on surrounding structures or by producing excess hormones. The most common hormone produced by chromophobe adenomas is prolactin, leading to symptoms such as menstrual irregularities, milk production (galactorrhea), and decreased sexual function in women, and decreased libido, erectile dysfunction, and infertility in men.
Treatment for chromophobe adenomas typically involves surgical removal of the tumor, often through a transsphenoidal approach (through the nose and sphenoid sinus). In some cases, radiation therapy or medical management with hormone-blocking drugs may also be necessary. Regular follow-up with an endocrinologist is important to monitor for any recurrence or hormonal imbalances.
Pituitary adenylate cyclase-activating polypeptide (PACAP) receptors are a type of G protein-coupled receptor that bind and respond to PACAP, a neuropeptide involved in various physiological functions such as neurotransmission, vasodilation, and hormone release. There are two main types of PACAP receptors: PAC1 and VPAC1/VPAC2. These receptors play important roles in the regulation of various bodily processes, including the stress response, circadian rhythms, and energy metabolism. Upon activation by PACAP, these receptors trigger a signaling cascade that leads to the activation of adenylate cyclase and an increase in intracellular cAMP levels, which in turn regulates various cellular responses.
Pro-opiomelanocortin (POMC) is a precursor protein that gets cleaved into several biologically active peptides in the body. These peptides include adrenocorticotropic hormone (ACTH), beta-lipotropin, and multiple opioid peptides such as beta-endorphin, met-enkephalin, and leu-enkephalin.
ACTH stimulates the release of cortisol from the adrenal gland, while beta-lipotropin has various metabolic functions. The opioid peptides derived from POMC have pain-relieving (analgesic) and rewarding effects in the brain. Dysregulation of the POMC system has been implicated in several medical conditions, including obesity, addiction, and certain types of hormone deficiencies.
Chondrocytes are the specialized cells that produce and maintain the extracellular matrix of cartilage tissue. They are responsible for synthesizing and secreting the collagen fibers, proteoglycans, and other components that give cartilage its unique properties, such as elasticity, resiliency, and resistance to compression. Chondrocytes are located within lacunae, or small cavities, in the cartilage matrix, and they receive nutrients and oxygen through diffusion from the surrounding tissue fluid. They are capable of adapting to changes in mechanical stress by modulating the production and organization of the extracellular matrix, which allows cartilage to withstand various loads and maintain its structural integrity. Chondrocytes play a crucial role in the development, maintenance, and repair of cartilaginous tissues throughout the body, including articular cartilage, costal cartilage, and growth plate cartilage.
Somatotrophs are a type of cell found within the anterior pituitary gland, a small endocrine gland located at the base of the brain. These cells are responsible for producing and secreting the hormone known as somatotropin or growth hormone (GH). This hormone plays a crucial role in regulating growth, cell reproduction, and regeneration. It also helps to regulate the body's metabolism and maintain proper body composition by promoting the breakdown of fats and the synthesis of proteins. Disorders related to somatotrophs can lead to conditions such as gigantism or dwarfism, depending on whether there is an overproduction or underproduction of growth hormone.
Gonadotrophs are a type of hormone-secreting cells located in the anterior pituitary gland, a small endocrine gland at the base of the brain. These cells produce and release two important gonadotropin hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
Follicle-stimulating hormone (FSH) plays a crucial role in the reproductive system by stimulating the growth and development of ovarian follicles in females and sperm production in males. In females, FSH also promotes the production of estrogen during the menstrual cycle.
Luteinizing hormone (LH) is responsible for triggering ovulation in females, releasing a mature egg from the ovary into the fallopian tube. In addition, LH stimulates the production of progesterone by the remaining cells of the ruptured follicle, which forms the corpus luteum. In males, LH helps regulate testosterone production in the testes.
Gonadotrophs are essential for maintaining reproductive function and hormonal balance in both sexes. Their activity is controlled by the hypothalamus, another part of the brain that releases gonadotropin-releasing hormone (GnRH) to regulate FSH and LH secretion.
A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.
Pituitary irradiation is a medical procedure that involves the use of targeted radiation therapy to treat conditions affecting the pituitary gland, a small endocrine gland located at the base of the brain. The pituitary gland controls various hormonal functions in the body, and any abnormalities or tumors in this area can lead to hormonal imbalances and other related health issues.
In pituitary irradiation, a radiation oncologist uses external beam radiation therapy (EBRT) to deliver precise and focused doses of high-energy radiation to the pituitary gland. The goal is to destroy or shrink the tumor while minimizing damage to surrounding healthy tissues. This procedure can be used as a primary treatment option, an adjuvant therapy following surgery, or in cases where surgical intervention is not feasible or has been unsuccessful.
The effects of pituitary irradiation on hormone production may take months or even years to manifest fully. Patients will typically require regular follow-ups with their healthcare team to monitor hormonal levels and manage any potential side effects, which can include fatigue, headaches, vision changes, and cognitive impairment. In some cases, hormone replacement therapy might be necessary to address hormonal deficiencies resulting from the treatment.
Osteopoikilosis is a rare, benign skeletal dysplasia characterized by multiple small, dense spots of sclerotic bone (osteosclerosis) in the spongy part (trabecular) of the bones. These spots are most commonly found in the short tubular bones of the hands and feet, as well as the long bones such as the femur and tibia. The condition is usually asymptomatic and discovered incidentally on X-ray or CT scan. It is typically present at birth or appears in early childhood, and it affects both sexes equally. Osteopoikilosis can be associated with other bone disorders, such as melorheostosis and Buschke-Ollendorff syndrome.
LHRH (Luteinizing Hormone-Releasing Hormone) receptors are a type of G protein-coupled receptor found on the surface of certain cells in the body, most notably in the anterior pituitary gland. These receptors bind to LHRH, a hormone that is produced and released by the hypothalamus in the brain.
When LHRH binds to its receptor, it triggers a series of intracellular signaling events that ultimately lead to the release of two other hormones from the anterior pituitary gland: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones play critical roles in regulating reproductive function, including the development and maturation of sex cells (sperm and eggs), the production of sex steroid hormones (such as testosterone and estrogen), and the regulation of the menstrual cycle in females.
Disorders of the LHRH receptor or its signaling pathway can lead to a variety of reproductive disorders, including precocious puberty, delayed puberty, and infertility.
"Body size" is a general term that refers to the overall physical dimensions and proportions of an individual's body. It can encompass various measurements, including height, weight, waist circumference, hip circumference, blood pressure, and other anthropometric measures.
In medical and public health contexts, body size is often used to assess health status, risk factors for chronic diseases, and overall well-being. For example, a high body mass index (BMI) may indicate excess body fat and increase the risk of conditions such as diabetes, hypertension, and cardiovascular disease. Similarly, a large waist circumference or high blood pressure may also be indicators of increased health risks.
It's important to note that body size is just one aspect of health and should not be used as the sole indicator of an individual's overall well-being. A holistic approach to health that considers multiple factors, including diet, physical activity, mental health, and social determinants of health, is essential for promoting optimal health outcomes.
The Sella Turcica, also known as the Turkish saddle, is a depression or fossa in the sphenoid bone located at the base of the skull. It forms a housing for the pituitary gland, which is a small endocrine gland often referred to as the "master gland" because it controls other glands and makes several essential hormones. The Sella Turcica has a saddle-like shape, with its anterior and posterior clinoids forming the front and back of the saddle, respectively. This region is of significant interest in neuroimaging and clinical settings, as various conditions such as pituitary tumors or other abnormalities may affect the size, shape, and integrity of the Sella Turcica.
A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.
Pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1-R) is a type of G protein-coupled receptor that binds to and is activated by the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP). PAC1-R is widely expressed in various tissues, including the central nervous system, endocrine organs, and the cardiovascular system. Activation of PAC1-R leads to the activation of adenylate cyclase and an increase in intracellular cAMP levels, which in turn activates downstream signaling pathways involved in a variety of physiological processes such as neurotransmission, hormone secretion, and vasodilation. Abnormalities in PAC1-R function have been implicated in several diseases, including migraine, depression, and certain types of cancer.
Cholestanols are a type of sterol that is similar in structure to cholesterol. They are found in small amounts in the body and can also be found in some foods. Cholestanols are formed when cholesterol undergoes a chemical reaction called isomerization, which changes its structure.
Cholestanols are important because they can accumulate in the body and contribute to the development of certain medical conditions. For example, elevated levels of cholestanols in the blood have been associated with an increased risk of cardiovascular disease. Additionally, some genetic disorders can cause an accumulation of cholestanols in various tissues, leading to a range of symptoms such as liver damage, neurological problems, and cataracts.
Medically, cholestanols are often used as markers for the diagnosis and monitoring of certain conditions related to cholesterol metabolism.
The pituitary gland is divided into three lobes: the anterior lobe (adenohypophysis), the posterior lobe (neurohypophysis), and the intermediate lobe (intermedia). The medical definition of 'Pituitary Gland, Intermediate' refers to this small and less defined region located between the anterior and posterior pituitary lobes.
The intermediate lobe is primarily responsible for producing and secreting several important hormones, most notably pro-opiomelanocortin (POMC)-derived peptides such as melanocyte-stimulating hormone (MSH) and endorphins. These hormones play crucial roles in various physiological processes, including skin pigmentation, energy balance, and pain modulation.
However, it is important to note that the intermediate lobe's activity and hormonal secretion are minimal in humans compared to other mammals. In fact, some researchers question whether the human intermediate lobe even functions at all under normal conditions due to its rudimentary nature. Nevertheless, understanding the structure and function of the pituitary gland's intermediate lobe is essential for comparative endocrinology and may provide insights into the evolution of the pituitary gland across different species.
Thyrotropin, also known as thyroid-stimulating hormone (TSH), is a hormone secreted by the anterior pituitary gland. Its primary function is to regulate the production and release of thyroxine (T4) and triiodothyronine (T3) hormones from the thyroid gland. Thyrotropin binds to receptors on the surface of thyroid follicular cells, stimulating the uptake of iodide and the synthesis and release of T4 and T3. The secretion of thyrotropin is controlled by the hypothalamic-pituitary-thyroid axis: thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the release of thyrotropin, while T3 and T4 inhibit its release through a negative feedback mechanism.
Gibberellins (GAs) are a type of plant hormones that regulate various growth and developmental processes, including stem elongation, germination of seeds, leaf expansion, and flowering. They are a large family of diterpenoid compounds that are synthesized from geranylgeranyl pyrophosphate (GGPP) in the plastids and then modified through a series of enzymatic reactions in the endoplasmic reticulum and cytoplasm.
GAs exert their effects by binding to specific receptors, which activate downstream signaling pathways that ultimately lead to changes in gene expression and cellular responses. The biosynthesis and perception of GAs are tightly regulated, and disruptions in these processes can result in various developmental abnormalities and growth disorders in plants.
In addition to their role in plant growth and development, GAs have also been implicated in the regulation of various physiological processes, such as stress tolerance, nutrient uptake, and senescence. They have also attracted interest as potential targets for crop improvement, as modulating GA levels and sensitivity can enhance traits such as yield, disease resistance, and abiotic stress tolerance.
A "mutant strain of mice" in a medical context refers to genetically engineered mice that have specific genetic mutations introduced into their DNA. These mutations can be designed to mimic certain human diseases or conditions, allowing researchers to study the underlying biological mechanisms and test potential therapies in a controlled laboratory setting.
Mutant strains of mice are created through various techniques, including embryonic stem cell manipulation, gene editing technologies such as CRISPR-Cas9, and radiation-induced mutagenesis. These methods allow scientists to introduce specific genetic changes into the mouse genome, resulting in mice that exhibit altered physiological or behavioral traits.
These strains of mice are widely used in biomedical research because their short lifespan, small size, and high reproductive rate make them an ideal model organism for studying human diseases. Additionally, the mouse genome has been well-characterized, and many genetic tools and resources are available to researchers working with these animals.
Examples of mutant strains of mice include those that carry mutations in genes associated with cancer, neurodegenerative disorders, metabolic diseases, and immunological conditions. These mice provide valuable insights into the pathophysiology of human diseases and help advance our understanding of potential therapeutic interventions.
Congenital limb deformities refer to abnormalities in the structure, position, or function of the arms or legs that are present at birth. These deformities can vary greatly in severity and may affect any part of the limb, including the bones, muscles, joints, and nerves.
Congenital limb deformities can be caused by genetic factors, exposure to certain medications or chemicals during pregnancy, or other environmental factors. Some common types of congenital limb deformities include:
1. Clubfoot: A condition in which the foot is twisted out of shape, making it difficult to walk normally.
2. Polydactyly: A condition in which a person is born with extra fingers or toes.
3. Radial clubhand: A rare condition in which the radius bone in the forearm is missing or underdeveloped, causing the hand to turn inward and the wrist to bend.
4. Amniotic band syndrome: A condition in which strands of the amniotic sac wrap around a developing limb, restricting its growth and leading to deformities.
5. Agenesis: A condition in which a limb or part of a limb is missing at birth.
Treatment for congenital limb deformities may include surgery, bracing, physical therapy, or other interventions depending on the severity and nature of the deformity. In some cases, early intervention and treatment can help to improve function and reduce the impact of the deformity on a person's daily life.
Follicle-stimulating hormone (FSH) is a glycoprotein hormone produced and released by the anterior pituitary gland. It plays crucial roles in the reproductive system, primarily by promoting the growth and development of follicles in the ovaries or sperm production in the testes.
The FSH molecule consists of two subunits: α (alpha) and β (beta). The α-subunit is common to several glycoprotein hormones, including thyroid-stimulating hormone (TSH), luteinizing hormone (LH), and human chorionic gonadotropin (hCG). In contrast, the β-subunit is unique to each hormone and determines its specific biological activity.
A medical definition of 'Follicle Stimulating Hormone, beta Subunit' refers to the distinct portion of the FSH molecule that is responsible for its particular functions in the body. The β-subunit of FSH enables the hormone to bind to its specific receptors in the gonads and initiate downstream signaling pathways leading to follicular development and spermatogenesis. Any alterations or mutations in the FSH beta subunit can lead to disruptions in reproductive processes, potentially causing infertility or other related disorders.
Cartilage is a type of connective tissue that is found throughout the body in various forms. It is made up of specialized cells called chondrocytes, which are embedded in a firm, flexible matrix composed of collagen fibers and proteoglycans. This unique structure gives cartilage its characteristic properties of being both strong and flexible.
There are three main types of cartilage in the human body: hyaline cartilage, elastic cartilage, and fibrocartilage.
1. Hyaline cartilage is the most common type and is found in areas such as the articular surfaces of bones (where they meet to form joints), the nose, trachea, and larynx. It has a smooth, glassy appearance and provides a smooth, lubricated surface for joint movement.
2. Elastic cartilage contains more elastin fibers than hyaline cartilage, which gives it greater flexibility and resilience. It is found in structures such as the external ear and parts of the larynx and epiglottis.
3. Fibrocartilage has a higher proportion of collagen fibers and fewer chondrocytes than hyaline or elastic cartilage. It is found in areas that require high tensile strength, such as the intervertebral discs, menisci (found in joints like the knee), and the pubic symphysis.
Cartilage plays a crucial role in supporting and protecting various structures within the body, allowing for smooth movement and providing a cushion between bones to absorb shock and prevent wear and tear. However, cartilage has limited capacity for self-repair and regeneration, making damage or degeneration of cartilage tissue a significant concern in conditions such as osteoarthritis.
Human Growth Hormone (HGH), also known as somatotropin, is a peptide hormone produced in the pituitary gland. It plays a crucial role in human development and growth by stimulating the production of another hormone called insulin-like growth factor 1 (IGF-1). IGF-1 promotes the growth and reproduction of cells throughout the body, particularly in bones and other tissues. HGH also helps regulate body composition, body fluids, muscle and bone growth, sugar and fat metabolism, and possibly heart function. It is essential for human development and continues to have important effects throughout life. The secretion of HGH decreases with age, which is thought to contribute to the aging process.
Pituitary hormone-regulating hormone receptors refer to specific protein structures found on the surface of certain cells in the body. These receptors are responsible for detecting and responding to hormones produced by the hypothalamus, which regulate the function of the pituitary gland.
The pituitary gland is a small gland located at the base of the brain that plays a critical role in regulating various bodily functions, including growth and development, metabolism, reproduction, and stress response. The hypothalamus produces hormones that either stimulate or inhibit the release of pituitary hormones, which then act on target organs throughout the body to regulate their function.
Pituitary hormone-regulating hormone receptors are found on the surface of pituitary cells and are specific to individual hypothalamic hormones. When a hypothalamic hormone binds to its corresponding receptor, it triggers a series of intracellular signals that ultimately result in the release or inhibition of pituitary hormones.
Examples of pituitary hormone-regulating hormone receptors include:
* Thyroid-stimulating hormone (TSH) receptor, which responds to thyrotropin-releasing hormone (TRH) from the hypothalamus.
* Adrenocorticotropic hormone (ACTH) receptor, which responds to corticotropin-releasing hormone (CRH) from the hypothalamus.
* Growth hormone-releasing hormone (GHRH) receptor, which responds to GHRH from the hypothalamus.
* Gonadotropin-releasing hormone (GnRH) receptor, which responds to GnRH from the hypothalamus.
* Prolactin-inhibiting hormone (PIH) receptor, which responds to dopamine from the hypothalamus.
Abnormalities in pituitary hormone-regulating hormone receptors can lead to various endocrine disorders, such as hypothyroidism, Cushing's disease, acromegaly, and infertility.
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.
The hypothalamus is a small, vital region of the brain that lies just below the thalamus and forms part of the limbic system. It plays a crucial role in many important functions including:
1. Regulation of body temperature, hunger, thirst, fatigue, sleep, and circadian rhythms.
2. Production and regulation of hormones through its connection with the pituitary gland (the hypophysis). It controls the release of various hormones by producing releasing and inhibiting factors that regulate the anterior pituitary's function.
3. Emotional responses, behavior, and memory formation through its connections with the limbic system structures like the amygdala and hippocampus.
4. Autonomic nervous system regulation, which controls involuntary physiological functions such as heart rate, blood pressure, and digestion.
5. Regulation of the immune system by interacting with the autonomic nervous system.
Damage to the hypothalamus can lead to various disorders like diabetes insipidus, growth hormone deficiency, altered temperature regulation, sleep disturbances, and emotional or behavioral changes.
Luteinizing Hormone (LH) is a glycoprotein hormone secreted by the anterior pituitary gland. It plays a crucial role in regulating the reproductive system. The beta subunit of LH is one of the two non-identical polypeptide chains that make up the LH molecule (the other being the alpha subunit, which is common to several hormones).
The beta subunit of LH is unique to LH and is often used in assays to measure and determine the concentration of LH in blood or urine. It's responsible for the biological specificity and activity of the LH hormone. Any changes in the structure of this subunit can affect the function of LH, which in turn can have implications for reproductive processes such as ovulation and testosterone production.
Hypophysectomy is a surgical procedure that involves the removal or partial removal of the pituitary gland, also known as the hypophysis. The pituitary gland is a small endocrine gland located at the base of the brain, just above the nasal cavity, and is responsible for producing and secreting several important hormones that regulate various bodily functions.
Hypophysectomy may be performed for therapeutic or diagnostic purposes. In some cases, it may be used to treat pituitary tumors or other conditions that affect the function of the pituitary gland. It may also be performed as a research procedure in animal models to study the effects of pituitary hormone deficiency on various physiological processes.
The surgical approach for hypophysectomy may vary depending on the specific indication and the patient's individual anatomy. In general, however, the procedure involves making an incision in the skull and exposing the pituitary gland through a small opening in the bone. The gland is then carefully dissected and removed or partially removed as necessary.
Potential complications of hypophysectomy include damage to surrounding structures such as the optic nerves, which can lead to vision loss, and cerebrospinal fluid leaks. Additionally, removal of the pituitary gland can result in hormonal imbalances that may require long-term management with hormone replacement therapy.
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.
The metatarsal bones are a group of five long bones in the foot that connect the tarsal bones in the hindfoot to the phalanges in the forefoot. They are located between the tarsal and phalangeal bones and are responsible for forming the arch of the foot and transmitting weight-bearing forces during walking and running. The metatarsal bones are numbered 1 to 5, with the first metatarsal being the shortest and thickest, and the fifth metatarsal being the longest and thinnest. Each metatarsal bone has a base, shaft, and head, and they articulate with each other and with the surrounding bones through joints. Any injury or disorder affecting the metatarsal bones can cause pain and difficulty in walking or standing.
"Bone" is the hard, dense connective tissue that makes up the skeleton of vertebrate animals. It provides support and protection for the body's internal organs, and serves as a attachment site for muscles, tendons, and ligaments. Bone is composed of cells called osteoblasts and osteoclasts, which are responsible for bone formation and resorption, respectively, and an extracellular matrix made up of collagen fibers and mineral crystals.
Bones can be classified into two main types: compact bone and spongy bone. Compact bone is dense and hard, and makes up the outer layer of all bones and the shafts of long bones. Spongy bone is less dense and contains large spaces, and makes up the ends of long bones and the interior of flat and irregular bones.
The human body has 206 bones in total. They can be further classified into five categories based on their shape: long bones, short bones, flat bones, irregular bones, and sesamoid bones.
A syndrome, in medical terms, is a set of symptoms that collectively indicate or characterize a disease, disorder, or underlying pathological process. It's essentially a collection of signs and/or symptoms that frequently occur together and can suggest a particular cause or condition, even though the exact physiological mechanisms might not be fully understood.
For example, Down syndrome is characterized by specific physical features, cognitive delays, and other developmental issues resulting from an extra copy of chromosome 21. Similarly, metabolic syndromes like diabetes mellitus type 2 involve a group of risk factors such as obesity, high blood pressure, high blood sugar, and abnormal cholesterol or triglyceride levels that collectively increase the risk of heart disease, stroke, and diabetes.
It's important to note that a syndrome is not a specific diagnosis; rather, it's a pattern of symptoms that can help guide further diagnostic evaluation and management.
Glycoprotein hormones are a group of hormones that share a similar structure and are made up of four subunits: two identical alpha subunits and two distinct beta subunits. The alpha subunit is common to all glycoprotein hormones, including thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and human chorionic gonadotropin (hCG).
The alpha subunit of glycoprotein hormones is a 92 amino acid polypeptide chain that contains several disulfide bonds, which help to stabilize its structure. It is heavily glycosylated, meaning that it contains many carbohydrate groups attached to the protein backbone. The alpha subunit plays an important role in the biological activity of the hormone by interacting with a specific receptor on the target cell surface.
The alpha subunit contains several regions that are important for its function, including a signal peptide, a variable region, and a conserved region. The signal peptide is a short sequence of amino acids at the N-terminus of the protein that directs it to the endoplasmic reticulum for processing and secretion. The variable region contains several amino acid residues that differ between different glycoprotein hormones, while the conserved region contains amino acids that are identical or very similar in all glycoprotein hormones.
Together with the beta subunit, the alpha subunit forms the functional hormone molecule. The beta subunit determines the specificity of the hormone for its target cells and regulates its biological activity.
Endocrine gland
Dwarfism
Jakob Erdheim
Ben Woolf
Microdontia
Dwarf rabbit
Anterior pituitary
General Tom Thumb
Laron syndrome
Karl Slover
Somatotropic cell
Adam Rainer
Susan Cabot
Lethal dwarfism in rabbits
Cell engineering
Ateliosis
Metandienone
Growth-hormone-releasing hormone receptor
Hypothalamic-pituitary-somatotropic axis
Homo floresiensis
Lavinia Warren
List of MeSH codes (C05)
List of MeSH codes (C19)
Hypotonia
Zvi Laron
Stanozolol
Expression vector
List of diseases (P)
List of diseases (D)
Johanson-Blizzard syndrome
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Gland21
- It is a medical disorder as a result of an insufficient quantity of growth hormone produced from the pituitary gland. (xtra.net)
- However, pituitary dwarfism can result from genetic deficiencies, painful brain injury, being born with no pituitary gland, and in some situations, idiopathy. (xtra.net)
- Thyroid dwarfism can take place by a missing or poorly formed thyroid gland, a genetic deficiency that influences thyroid hormone presentation, low iodine in the diet of the mother, antithyroid medication or radioactive iodine, and the usage of other drugs that disturb thyroid hormone exposition such as lithium and antithyroid medicines. (xtra.net)
- The pituitary gland hangs from the base of the brain by the pituitary stalk, and is enclosed by bone. (wikipedia.org)
- The intermediate lobe of the pituitary gland secretes only one enzyme that is melanocyte stimulating hormone. (wikipedia.org)
- At the base of the human brain there lies a tiny organ called the pituitary gland . (damninteresting.com)
- Certain brain diseases, tumors, and trauma can cause the pituitary gland to reduce its output, which causes a host of ill effects. (damninteresting.com)
- Researchers recently discovered a novel mechanism that works over an extensive genomic distance and controls the expression of human growth hormone (hGH) in the pituitary gland. (sciencedaily.com)
- Researchers at the University of Pennsylvania School of Medicine recently discovered a novel mechanism that works over an extensive genomic distance and controls the expression of human growth hormone (hGH) in the pituitary gland. (sciencedaily.com)
- Synthesized by the pituitary gland, human growth hormone activates growth and cell reproduction. (sciencedaily.com)
- While the CD79b gene normally codes for a protein in blood lymphocytes, researchers discovered that CD79b appears to play a very different role in the pituitary gland. (sciencedaily.com)
- In order to determine whether the CD79b RNA in the pituitary gland served a function, Ho inserted a segment of human DNA that included hGH, the hGH locus control region, and CD79b into a group of mice. (sciencedaily.com)
- It occurs when the pituitary gland fails to produce adequate supply of growth hormone, which is necessary for proper childhood growth. (iloveindia.com)
- Testofuel is a science-based natural anabolic supplement that works by triggering the release of luteinizing hormone from the pituitary gland. (michnews.com)
- It works by triggering luteinizing hormone (LH) release from your pituitary gland, just like steroids. (michnews.com)
- Pituitary is and endocrine gland located within the sella turcica, residing inside the skull. (howmed.net)
- A 191-amino acid polypeptide hormone secreted by the human adenohypophysis (PITUITARY GLAND, ANTERIOR), also known as GH or somatotropin. (umassmed.edu)
- The hypothalamus (part of the brain) controls the pituitary gland, which in turn releases some of the hormones that control growth and sexual development. (kidshealth.org)
- This condition involves the pituitary gland, the small gland at the base of the brain that makes growth hormone along with other hormones. (kidshealth.org)
- If the pituitary gland doesn't make enough hormones, normal growth slows down or stops. (kidshealth.org)
- GH deficiency happens if the pituitary gland or hypothalamus is damaged or doesn't work as it should. (kidshealth.org)
Posterior pituitary5
- It consists of a hormone-producing glandular portion of the anterior pituitary and a neural portion of the posterior pituitary, which is an extension of the hypothalamus. (wikipedia.org)
- The hypothalamus regulates the hormonal output of the anterior pituitary and creates two hormones that it exports to the posterior pituitary for storage and later release. (wikipedia.org)
- Overproduction of ADH from the posterior pituitary is called? (studystack.com)
- Underproduction of ADH from the posterior pituitary is called? (studystack.com)
- Neurohypophysis or posterior pituitary (neural tissue outgrowth from hypothalamus) c. (howmed.net)
Deficiency3
- Hyposomatotropism is a deficiency in the release of pituitary growth hormone (somatotropin), resulting in short stature. (medscape.com)
- Hormone (GH) replacement in women with GH deficiency on the basis of pituitary/hypothalamic region tumors, radiation, or surgery on cardiovascular risk markers and arterial distensibility. (knowcancer.com)
- Synthetic growth hormone, termed somatropin, has replaced the natural form in therapeutic usage such as treatment of dwarfism in children with growth hormone deficiency. (umassmed.edu)
Hormones13
- The significant difference between pituitary and thyroid dwarfism is that pituitary dwarfism is a medical disorder resulting from the depletion of growth hormones. (xtra.net)
- Thyroid dwarfism is a medical disorder taking place as a result of the shortage of thyroid hormones. (xtra.net)
- The triggers of dwarfism may have to do with genetics, growth hormone depletion, depletion in other hormones, and impoverished nutrition. (xtra.net)
- Pituitary dwarfism can be diagnosed using a physical test, medical history, blood examination to know the levels of growth hormones and other hormones found in the body, and imaging examinations that have to do with the MRI and X-ray. (xtra.net)
- Dwarfism can be diagnosed using a physical test, medical history, blood examination for thyroid hormones, including T3 and T4, and genetic examination. (xtra.net)
- Pituitary dwarfism is described as a medical disorder resulting from a shortage of growth hormones. (xtra.net)
- In contrast, thyroid dwarfism is a medical disorder resulting from a weakness of thyroid hormones. (xtra.net)
- Four of the six anterior pituitary hormones are tropic hormones that regulate the function of other endocrine organs. (wikipedia.org)
- Most anterior pituitary hormones exhibit a diurnal rhythm of release, which is subject to modification by stimuli influencing the hypothalamus. (wikipedia.org)
- Overproduction of the growth hormones from the anterior pituitary is called what in adults? (studystack.com)
- Anterior pituitary consists of five different cell types producing six hormones. (howmed.net)
- Anterior pituitary secretions are regulated by the hormones from hypothalamus , acting through the hypothalamic-hypophysial portal system. (howmed.net)
- These diseases usually manifest as hypersecretion or hyposecretion of PITUITARY HORMONES. (edu.au)
Kinds of dwarfism3
- Hence, thyroid and pituitary dwarfism are two different kinds of dwarfism. (xtra.net)
- Read this article to understand different kinds of dwarfism and their symptoms. (iloveindia.com)
- My book (Comprehensive Biology class XI, by J P Sharma ) mentions of two kinds of dwarfism- "Pituitary Dwarfism" and "Thyroid Dwarfism" but does not provide any details about the matter. (stackexchange.com)
Anterior2
- Secretion is stimulated by the thyroid-stimulating hormone, secreted by the anterior pituitary. (wikipedia.org)
- Adenohypophysis or anterior pituitary (develops from Rathke's pouch) b. (howmed.net)
Laron-type dwa1
- What causes laron-type dwarfism (pygmies)? (flashcardmachine.com)
Types of dwarfism4
- There are nearly 200 types of dwarfism since the condition varies too much from person to person. (iloveindia.com)
- SD1 and SD2 are the two most common types of dwarfism in labs, while Chondrodysplasia, chondrodystrophy, and pituitary dwarfism are more common in other breeds. (everythinglabradors.com)
- So, how can you know if a lab has dwarfism, what types of dwarfism are there, and are there any additional health risks that come along with having canine dwarfism? (everythinglabradors.com)
- In many types of dwarfism, the arms and legs are short and look out of proportion to the rest of the body. (kidshealth.org)
Disorders2
- Disorders causing disproportionate dwarfism inhibit the development of bones. (iloveindia.com)
- While this type of dwarfism is incredibly rare in purebreds, lab lines that have been crossed with a breed that has either of these disorders could pass the trait on to their puppies. (everythinglabradors.com)
Stalk1
- It is connected through the pituitary stalk with the hypothalamus. (howmed.net)
Disorder5
- Dwarfism is a medical disorder that triggers short stature. (xtra.net)
- Pituitary dwarfism is typically a congenital disorder. (xtra.net)
- Thyroid dwarfism is described as a medical disorder resulting from a low amount of thyroid hormone found in the human body. (xtra.net)
- Pituitary dwarfism is known as a more typical disorder than thyroid dwarfism, which is a lesser familiar disorder. (xtra.net)
- It is a genetically transmitted endocrine disorder characterized by severe dwarfism. (mhmedical.com)
Gene8
- We tested the hypothesis that a variant of the LIM homeodomain gene LHX4 is responsible for the dwarfism phenotype. (nih.gov)
- It is concluded that the LHX4 gene does not play a primary role in the pituitary dwarfism in the German shepherd dogs. (nih.gov)
- Remarkably this CD79b gene was also copied into RNA in the pituitary. (sciencedaily.com)
- This DNA insertion specifically blocked the copying of the CD79b gene into RNA in the pituitary. (sciencedaily.com)
- Genetic engineering has been used to clone this growth hormone gene, which has enabled the production of growth hormone used in the treatment of pituitary dwarfism. (pearson.com)
- The SD1 gene is recessive, meaning that dogs that don't have any sort of dwarfism can still silently carry and pass on the gene to their puppies. (everythinglabradors.com)
- The most common form of dwarfism in labradors is Skeletal Dysplasia 2, which is a hereditary condition caused by the SD2 gene. (everythinglabradors.com)
- Mutation of the gene encoding the GH receptor (Type I dwarfism) or a defect in the postreceptor signaling mechanism (Type II dwarfism), resulting in complete resistance to the action of GH and failure to generate somatomedin or insulin-like growth factor-1 (IGF-1). (mhmedical.com)
Hyposecretion1
- hyposecretion in children causes pituitary dwarfism. (wikipedia.org)
Achondroplasia1
- In Achondroplasia, which is a type of disproportionate dwarfism which accounts for almost seventy percent of all dwarfism cases, the trunk is of normal size but the limbs are disproportionately short. (iloveindia.com)
Glands1
- The hypothalamus and pituitary glands are neuroendocrine organs. (wikipedia.org)
Type of dwarfism3
- This type of dwarfism is diagnosed when the body size is disproportionate. (iloveindia.com)
- This type of dwarfism results when the body appears normally proportioned, but is abnormally small. (iloveindia.com)
- The symptoms for this type of dwarfism are: height below the third percentile of standard sizes or growth rate slower than expected for age. (iloveindia.com)
Thyroid hormone1
- Also, the treatment choices for thyroid dwarfism have to do with the administration of thyroid hormone. (xtra.net)
Diagnosis1
- If you suspect that your lab has dwarfism, you should take your dog to a vet's office for a proper diagnosis. (everythinglabradors.com)
Overproduction1
- Thus growth hormone is a diabetogenic hormone producing pituitary diabetes (due to overproduction of glucose and decreased utilization). (howmed.net)
Breeds1
- Labradors are some of the friendliest and most well-loved dog breeds out there but if you want to get a new pet lab, how can you know if it has dwarfism? (everythinglabradors.com)
Degenerative1
- A bit un-nerving to know that this dog reproduced both pituitary dwarfism (Nemo von der Schafermeister) AND degenerative myleopathy (Siggo vom Drachenberg), just that I am aware of. (pedigreedatabase.com)
Canine2
- These are all signs of canine dwarfism. (everythinglabradors.com)
- There are multiple different types of canine dwarfism, which affect both pure bread and mixed labradors. (everythinglabradors.com)
Growth5
- Pituitary dwarfism can also be described as growth hormone depletion. (xtra.net)
- Also, the treatment choices for pituitary dwarfism may have to do with the application of synthetic growth hormone under the guidance of a pediatric endocrinologist. (xtra.net)
- However, when this condition occurs in a child, the shortage of growth hormone usually leads to pituitary dwarfism, resulting in an abnormally short stature with normal body proportions. (damninteresting.com)
- It seems that his malfunctioning pituitary had gone from producing too little growth hormone to producing far too much, and over the next eleven years he grew an average of 3.6 inches per year. (damninteresting.com)
- As a result, the transgenic mice expressed high levels of human growth hormone in the pituitary as well as mouse growth hormone. (sciencedaily.com)
Organs1
- Role of Otx1 in corticogenesis, pituitary functions and sense organs development. (cnr.it)
Brain1
- People suffering from disproportionate dwarfism have normal intellectual capacities mostly but in rare cases a secondary factor, such as excess fluid around the brain (hydrocephalus) can hamper these. (iloveindia.com)
Dogs3
- Dwarfism in dogs is associated with many different health problems including IVDD, hip and elbow dysplasia, eye problems, heart disease, and other abnormalities and symptoms. (everythinglabradors.com)
- There are a few different visible signs that dogs with dwarfism display, making it pretty easy for the average dog owner to tell if their lab has dwarfism. (everythinglabradors.com)
- Chondrodysplasia and chondrodystrophy are some of the most common and well-known forms of dwarfism that appear in dogs. (everythinglabradors.com)
Excessive1
- This swelling originates in the pituitary, often producing excessive amounts of one or more of the gland's chemical messengers. (damninteresting.com)
Exhibit1
- There are a few obvious visible signs that a labrador will exhibit if it has dwarfism, including having short legs, bowed or bent knees, turned-out feet, a low-slung back, and a disproportionately large head. (everythinglabradors.com)
Short4
- Kids with pituitary dwarfism are unusually short but possess normal body proportions. (xtra.net)
- Turner syndrome is the most common type of proportionate dwarfism which includes short stature and impaired sexual maturation in females. (iloveindia.com)
- Though, dwarfism can never be treated completely, its symptoms can always be diminished to a short extent by medication. (iloveindia.com)
- Another condition that can lead to significantly short stature is dwarfism . (kidshealth.org)
Children1
- This will certainly stand you in good stead aND MY HUSBAND STARTED INJECTING THESE originally developed in the 1950s to treat dwarfism in children, and the first preparations were extracts of the raw hormone from the pituitary of cadavers. (htdig.org)
Condition1
- Dwarfism is a highly visible condition and often carries negative connotations in society. (iloveindia.com)
Body1
- How will you differentiate dwarfism by body ratio? (medicosnotes.com)