The movement of cells or organisms toward or away from a substance in response to its concentration gradient.
The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.
Chemical substances that attract or repel cells. The concept denotes especially those factors released as a result of tissue injury, microbial invasion, or immunologic activity, that attract LEUKOCYTES; MACROPHAGES; or other cells to the site of infection or insult.
Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.
A genus of protozoa, formerly also considered a fungus. Its natural habitat is decaying forest leaves, where it feeds on bacteria. D. discoideum is the best-known species and is widely used in biomedical research.
A formylated tripeptide originally isolated from bacterial filtrates that is positively chemotactic to polymorphonuclear leucocytes, and causes them to release lysosomal enzymes and become metabolically activated.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A CXC chemokine that is chemotactic for T-LYMPHOCYTES and MONOCYTES. It has specificity for CXCR4 RECEPTORS. Two isoforms of CXCL12 are produced by alternative mRNA splicing.
Proteins found in any species of bacterium.
Group of chemokines with paired cysteines separated by a different amino acid. CXC chemokines are chemoattractants for neutrophils but not monocytes.
A family of G-protein-coupled receptors that was originally identified by its ability to bind N-formyl peptides such as N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE. Since N-formyl peptides are found in MITOCHONDRIA and BACTERIA, this class of receptors is believed to play a role in mediating cellular responses to cellular damage and bacterial invasion. However, non-formylated peptide ligands have also been found for this receptor class.
The minor fragment formed when C5 convertase cleaves C5 into C5a and COMPLEMENT C5B. C5a is a 74-amino-acid glycopeptide with a carboxy-terminal ARGININE that is crucial for its spasmogenic activity. Of all the complement-derived anaphylatoxins, C5a is the most potent in mediating immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE), smooth MUSCLE CONTRACTION; HISTAMINE RELEASE; and migration of LEUKOCYTES to site of INFLAMMATION.
Cell surface glycoproteins that bind to chemokines and thus mediate the migration of pro-inflammatory molecules. The receptors are members of the seven-transmembrane G protein-coupled receptor family. Like the CHEMOKINES themselves, the receptors can be divided into at least three structural branches: CR, CCR, and CXCR, according to variations in a shared cysteine motif.
High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and T-LYMPHOCYTES. These receptors also bind several other CXC CHEMOKINES.
A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
Phenomenon of cell-mediated immunity measured by in vitro inhibition of the migration or phagocytosis of antigen-stimulated LEUKOCYTES or MACROPHAGES. Specific CELL MIGRATION ASSAYS have been developed to estimate levels of migration inhibitory factors, immune reactivity against tumor-associated antigens, and immunosuppressive effects of infectious microorganisms.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and BASOPHILS.
Physiological processes and properties of BACTERIA.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
A member of the CXC chemokine family that plays a role in the regulation of the acute inflammatory response. It is secreted by variety of cell types and induces CHEMOTAXIS of NEUTROPHILS and other inflammatory cells.
CXCR receptors with specificity for CXCL12 CHEMOKINE. The receptors may play a role in HEMATOPOIESIS regulation and can also function as coreceptors for the HUMAN IMMUNODEFICIENCY VIRUS.
Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.
A dynamic actin-rich extension of the surface of an animal cell used for locomotion or prehension of food.
Cell surface proteins that bind amino acids and trigger changes which influence the behavior of cells. Glutamate receptors are the most common receptors for fast excitatory synaptic transmission in the vertebrate central nervous system, and GAMMA-AMINOBUTYRIC ACID and glycine receptors are the most common receptors for fast inhibition.
Group of chemokines with adjacent cysteines that are chemoattractants for lymphocytes, monocytes, eosinophils, basophils but not neutrophils.
The major metabolite in neutrophil polymorphonuclear leukocytes. It stimulates polymorphonuclear cell function (degranulation, formation of oxygen-centered free radicals, arachidonic acid release, and metabolism). (From Dictionary of Prostaglandins and Related Compounds, 1990)
Class of pro-inflammatory cytokines that have the ability to attract and activate leukocytes. They can be divided into at least three structural branches: C; (CHEMOKINES, C); CC; (CHEMOKINES, CC); and CXC; (CHEMOKINES, CXC); according to variations in a shared cysteine motif.
Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.
A chemokine that is a chemoattractant for MONOCYTES and may also cause cellular activation of specific functions related to host defense. It is produced by LEUKOCYTES of both monocyte and lymphocyte lineage and by FIBROBLASTS during tissue injury. It has specificity for CCR2 RECEPTORS.
Adherence of cells to surfaces or to other cells.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)
Effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eucaryotic cells.
CCR receptors with specificity for CHEMOKINE CCL2 and several other CCL2-related chemokines. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; MACROPHAGES; BASOPHILS; and NK CELLS.
A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards T LYMPHOCYTES and B LYMPHOCYTES.
Phosphotransferases that catalyzes the conversion of 1-phosphatidylinositol to 1-phosphatidylinositol 3-phosphate. Many members of this enzyme class are involved in RECEPTOR MEDIATED SIGNAL TRANSDUCTION and regulation of vesicular transport with the cell. Phosphatidylinositol 3-Kinases have been classified both according to their substrate specificity and their mode of action within the cell.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
CCR receptors with specificity for a broad variety of CC CHEMOKINES. They are expressed at high levels in MONOCYTES; tissue MACROPHAGES; NEUTROPHILS; and EOSINOPHILS.
Assays that measure the rate of migration of LEUKOCYTES. They may involve a variety of techniques such as measuring the movement of leukocytes through substrates such as AGAROSE gels or the rate of exit of cells from a glass capillary.
A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.
A CC-type chemokine that is a chemoattractant for EOSINOPHILS; MONOCYTES; and LYMPHOCYTES. It is a potent and selective eosinophil chemotaxin that is stored in and released from PLATELETS and activated T-LYMPHOCYTES. Chemokine CCL5 is specific for CCR1 RECEPTORS; CCR3 RECEPTORS; and CCR5 RECEPTORS. The acronym RANTES refers to Regulated on Activation, Normal T Expressed and Secreted.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
The process in which the neutrophil is stimulated by diverse substances, resulting in degranulation and/or generation of reactive oxygen products, and culminating in the destruction of invading pathogens. The stimulatory substances, including opsonized particles, immune complexes, and chemotactic factors, bind to specific cell-surface receptors on the neutrophil.
C5 plays a central role in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C5 is cleaved by C5 CONVERTASE into COMPLEMENT C5A and COMPLEMENT C5B. The smaller fragment C5a is an ANAPHYLATOXIN and mediator of inflammatory process. The major fragment C5b binds to the membrane initiating the spontaneous assembly of the late complement components, C5-C9, into the MEMBRANE ATTACK COMPLEX.
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.
CXCR receptors that are expressed on the surface of a number of cell types, including T-LYMPHOCYTES; NK CELLS; DENDRITIC CELLS; and a subset of B-LYMPHOCYTES. The receptors are activated by CHEMOKINE CXCL9; CHEMOKINE CXCL10; and CHEMOKINE CXCL11.
Established cell cultures that have the potential to propagate indefinitely.
Cell surface proteins that bind LIPOXINS with high affinity and trigger intracellular changes influencing the behavior of cells.
A promyelocytic cell line derived from a patient with ACUTE PROMYELOCYTIC LEUKEMIA. HL-60 cells lack specific markers for LYMPHOID CELLS but express surface receptors for FC FRAGMENTS and COMPLEMENT SYSTEM PROTEINS. They also exhibit phagocytic activity and responsiveness to chemotactic stimuli. (From Hay et al., American Type Culture Collection, 7th ed, pp127-8)
A monocyte chemoattractant protein that has activity towards a broad variety of immune cell types. Chemokine CCL7 has specificity for CCR1 RECEPTORS; CCR2 RECEPTORS; and CCR5 RECEPTORS.
A species of motile, free-living, gram-negative bacteria that occur in the soil. They are aerobic or microaerophilic and are sometimes capable of nitrogen fixation.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
A genus of flexible, spiral rods found in hydrogen sulfide-containing mud, sewage, and polluted water. None of the species properly referred to in this genus are pathogenic.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
A CC-type chemokine with specificity for CCR7 RECEPTORS. It has activity towards DENDRITIC CELLS and T-LYMPHOCYTES.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Heparin-binding proteins that exhibit a number of inflammatory and immunoregulatory activities. Originally identified as secretory products of MACROPHAGES, these chemokines are produced by a variety of cell types including NEUTROPHILS; FIBROBLASTS; and EPITHELIAL CELLS. They likely play a significant role in respiratory tract defenses.
Zymosan is a polysaccharide derived from the cell walls of Saccharomyces cerevisiae, commonly used in research as an immunostimulant to induce inflammation and study phagocytosis, complement activation, and oxidative burst in neutrophils and macrophages.
One of the virulence factors produced by BORDETELLA PERTUSSIS. It is a multimeric protein composed of five subunits S1 - S5. S1 contains mono ADPribose transferase activity.
A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.
CCR receptors with specificity for CHEMOKINE CCL11 and a variety of other CC CHEMOKINES. They are expressed at high levels in T-LYMPHOCYTES; EOSINOPHILS; BASOPHILS; and MAST CELLS.
CCR receptors with specificity for CHEMOKINE CCL19 and CHEMOKINE CCL21. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS.
Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.
White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).
The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)
Chemokines that are chemoattractants for monocytes. These CC chemokines (cysteines adjacent) number at least three including CHEMOKINE CCL2.
Phosphatidylinositols in which one or more alcohol group of the inositol has been substituted with a phosphate group.
Microscopy in which television cameras are used to brighten magnified images that are otherwise too dark to be seen with the naked eye. It is used frequently in TELEPATHOLOGY.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
Mitogenic peptide growth hormone carried in the alpha-granules of platelets. It is released when platelets adhere to traumatized tissues. Connective tissue cells near the traumatized region respond by initiating the process of replication.
A class of cell surface leukotriene receptors with a preference for leukotriene B4. Leukotriene B4 receptor activation influences chemotaxis, chemokinesis, adherence, enzyme release, oxidative bursts, and degranulation in polymorphonuclear leukocytes. There are at least two subtypes of these receptors. Some actions are mediated through the inositol phosphate and diacylglycerol second messenger systems.
The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.
A CXC chemokine with specificity for CXCR2 RECEPTORS. It has growth factor activities and is implicated as a oncogenic factor in several tumor types.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Proteins obtained from ESCHERICHIA COLI.
A CC chemokine with specificity for CCR5 RECEPTORS. It is a chemoattractant for NK CELLS; MONOCYTES and a variety of other immune cells. This chemokine is encoded by multiple genes.
A G-protein-coupled receptor that signals an increase in intracellular calcium in response to the potent ANAPHYLATOXIN peptide COMPLEMENT C5A.
Proteins prepared by recombinant DNA technology.
A CX3C chemokine that is a transmembrane protein found on the surface of cells. The soluble form of chemokine CX3CL1 can be released from cell surface by proteolysis and act as a chemoattractant that may be involved in the extravasation of leukocytes into inflamed tissues. The membrane form of the protein may also play a role in cell adhesion.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
The study of fluid channels and chambers of tiny dimensions of tens to hundreds of micrometers and volumes of nanoliters or picoliters. This is of interest in biological MICROCIRCULATION and used in MICROCHEMISTRY and INVESTIGATIVE TECHNIQUES.
A phosphatidylinositol 3-kinase subclass that includes enzymes formed through the association of a p110gamma catalytic subunit and one of the three regulatory subunits of 84, 87, and 101 kDa in size. This subclass of enzymes is a downstream target of G PROTEIN-COUPLED RECEPTORS.
The rate dynamics in chemical or physical systems.
Derivatives of PHOSPHATIDIC ACIDS that lack one of its fatty acyl chains due to its hydrolytic removal.
A subclass of enzymes of the transferase class that catalyze the transfer of a methyl group from one compound to another. (Dorland, 28th ed) EC 2.1.1.
A CC-type chemokine that is specific for CCR3 RECEPTORS. It is a potent chemoattractant for EOSINOPHILS.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.

Cell polarization: chemotaxis gets CRACKing. (1/5128)

An early stage in the establishment of cell polarity during chemotaxis of Dictyostelium dicoideum has been identified by a recent study; the new results also show that the development of cell polarity does not rely upon cytoskeletal rearrangement, and may use a spatial sensing mechanism.  (+info)

Tyrosine phosphorylation is required for actin-based motility of vaccinia but not Listeria or Shigella. (2/5128)

Studies of the actin-based motility of pathogens have provided important insights into the events occurring at the leading edge of motile cells [1] [2] [3]. To date, several actin-cytoskeleton-associated proteins have been implicated in the motility of Listeria or Shigella: vasodilator-stimulated phosphoprotein (VASP), vinculin and the actin-related protein complex of Arp2 and Arp3 [4] [5] [6] [7]. To further investigate the underlying mechanism of actin-tail assembly, we examined the localization of components of the actin cytoskeleton including Arp3, VASP, vinculin and zyxin during vaccinia, Listeria and Shigella infections. The most striking difference between the systems was that a phosphotyrosine signal was observed only at the site of vaccinia actin-tail assembly. Micro-injection experiments demonstrated that a phosphotyrosine protein plays an important role in vaccinia actin-tail formation. In addition, we observed a phosphotyrosine signal on clathrin-coated vesicles that have associated actin-tail-like structures and on endogenous vesicles in Xenopus egg extracts which are able to nucleate actin tails [8] [9]. Our observations indicate that a host phosphotyrosine protein is required for the nucleation of actin filaments by vaccinia and suggest that this phosphoprotein might be associated with cellular membranes that can nucleate actin.  (+info)

Role of thrombin receptor in breast cancer invasiveness. (3/5128)

Invasion, the ability of an epithelial cancer cell to detach from and move through a basement membrane, is a central process in tumour metastasis. Two components of invasion are proteolysis of extracellular matrix and cellular movement through it. A potential promoter of these two processes is thrombin, the serine proteinase derived from the ubiquitous plasma protein prothrombin. Thrombin promotes the invasion of MDA-MB231 breast tumour cells (a highly aggressive cell line) in an in vitro assay. Invasion by MDA-MB436 and MCF-7 cells, less aggressive cell lines, is not promoted by thrombin. Thrombin, added to the cells, is a stimulator of cellular movement; fibroblast-conditioned medium is the chemotaxin. Thrombin-promoted invasion is inhibited by hirudin. Stimulation of invasion is a receptor-mediated process that is mimicked by a thrombin receptor-activating peptide. Thrombin has no effect on chemotaxis in vitro. Thrombin receptor is detectable on the surface of MDA-MB231 cells, but not on the other two cell lines. Introduction of oestrogen receptors into MDA-MB231 cells by transfection with pHEO had no effect on thrombin receptor expression, in the presence or absence of oestradiol. This paper demonstrates that thrombin increases invasion by the aggressive breast cancer cell line MDA-MB231 by a thrombin receptor-dependent mechanism.  (+info)

Similarities and differences in RANTES- and (AOP)-RANTES-triggered signals: implications for chemotaxis. (4/5128)

Chemokines are a family of proinflammatory cytokines that attract and activate specific types of leukocytes. Chemokines mediate their effects via interaction with seven transmembrane G protein-coupled receptors (GPCR). Using CCR5-transfected HEK-293 cells, we show that both the CCR5 ligand, RANTES, as well as its derivative, aminooxypentane (AOP)- RANTES, trigger immediate responses such as Ca2+ influx, receptor dimerization, tyrosine phosphorylation, and Galphai as well as JAK/STAT association to the receptor. In contrast to RANTES, (AOP)-RANTES is unable to trigger late responses, as measured by the association of focal adhesion kinase (FAK) to the chemokine receptor complex, impaired cell polarization required for migration, or chemotaxis. The results are discussed in the context of the dissociation of the late signals, provoked by the chemokines required for cell migration, from early signals.  (+info)

Chemotactic responses of Escherichia coli to small jumps of photoreleased L-aspartate. (5/5128)

Computer-assisted motion analysis coupled to flash photolysis of caged chemoeffectors provides a means for time-resolved analysis of bacterial chemotaxis. Escherichia coli taxis toward the amino acid attractant L-aspartate is mediated by the Tar receptor. The physiology of this response, as well as Tar structure and biochemistry, has been studied extensively. The beta-2, 6-dinitrobenzyl ester of L-aspartic acid and the 1-(2-nitrophenyl)ethyl ether of 8-hydroxypyrene-1,3,6-tris-sulfonic acid were synthesized. These compounds liberated L-aspartate and the fluorophore 8-hydroxypyrene 1,3,6-tris-sulfonic acid (pyranine) upon irradiation with near-UV light. Photorelease of the fluorophore was used to define the amplitude and temporal stability of the aspartate jumps employed in chemotaxis experiments. The dependence of chemotactic adaptation times on aspartate concentration, determined in mixing experiments, was best fit by two Tar aspartate-binding sites. Signal processing (excitation) times, amplitudes, and adaptive recovery of responses elicited by aspartate jumps producing less than 20% change in receptor occupancy were characterized in photorelease assays. Aspartate concentration jumps in the nanomolar range elicited measurable responses. The response threshold and sensitivity of swimming bacteria matched those of bacteria tethered to glass by a single flagellum. Stimuli of similar magnitude, delivered either by rapid mixing or photorelease, evoked responses of similar strength, as assessed by recovery time measurements. These times remained proportional to change in receptor occupancy close to threshold, irrespective of prior occupancy. Motor excitation responses decayed exponentially with time. Rates of excitation responses near threshold ranged from 2 to 7 s-1. These values are consistent with control of excitation signaling by decay of phosphorylated pools of the response regulator protein, CheY. Excitation response rates increased slightly with stimulus size up to values limited by the instrumentation; the most rapid was measured to be 16 +/- 3 (SE) s-1. This increase may reflect simultaneous activation of CheY dephosphorylation, together with inhibition of its phosphorylation.  (+info)

Tn5-induced and spontaneous switching of Sinorhizobium meliloti to faster-swarming behavior. (6/5128)

Tn5 mutants of Sinorhizobium meliloti RMB7201 which swarmed 1.5 to 2. 5 times faster than the parental strain in semisolid agar, moist sand, and viscous liquid were identified. These faster-swarming (FS) mutants outgrew the wild type 30- to 40-fold within 2 days in mixed swarm colonies. The FS mutants survived and grew as well as or better than the wild type under all of the circumstances tested, except in a soil matrix subjected to air drying. Exopolysaccharide (EPS) synthesis was reduced in each of the FS mutants when they were grown on defined succinate-nitrate medium, but the extent of reduction was different for each. It appears that FS behavior likely results from a modest, general derepression of motility involving an increased proportion of motile and flagellated cells and an increased average number of flagella per cell and increased average flagellar length. Spontaneous FS variants of RMB7201 were obtained at a frequency of about 1 per 10,000 to 20,000 cells by either enrichment from the periphery of swarm colonies or screening of colonies for reduced EPS synthesis on succinate-nitrate plates. The spontaneous FS variants and Tn5 FS mutants were symbiotically effective and competitive in alfalfa nodulation. Reversion of FS variants to wild-type behavior was sporadic, indicating that reversion is affected by unidentified environmental factors. Based on phenotypic and molecular differences between individual FS variants and mutants, it appears that there may be multiple genetic configurations that result in FS behavior in RMB7201. The facile isolation of spontaneous FS variants of Escherichia coli and Pseudomonas aeruginosa indicates that switching to FS behavior may be fairly common among bacterial species. The substantial growth advantage of FS mutants and variants wherever nutrient gradients exist suggests that switching to FS forms may be an important behavioral adaptation in natural environments.  (+info)

Sperm chemotaxis. (7/5128)

Communication between spermatozoa and egg before contact by chemotaxis appears to be prevalent throughout the animal kingdom. In non-mammalian species, sperm chemotaxis to factors secreted from the egg is well documented. In mammals, sperm chemotaxis to follicular factors in vitro has been established in humans and mice. The attractants of female origin in non-mammalian species are heat-stable peptides or proteins of various sizes, or other small molecules, depending on the species. Species specificity of the attractants in non-mammalian species may vary from high species specificity, through specificity to families with no specificity within a family, to absence of specificity. The mammalian sperm attractants have not been identified but they appear to be heat-stable peptides. The claim that progesterone is the attractant for human spermatozoa has failed to be substantiated, neither have claims for other mammalian sperm attractants been verified. The molecular mechanism of sperm chemotaxis is not known. Models involving modulation of the intracellular Ca2+ concentration have been proposed for both mammalian and non-mammalian sperm chemotaxis. The physiological role of sperm chemotaxis in non-mammalian species appears to differ from that in mammals. In non-mammalian species, sperm chemotaxis strives to bring as many spermatozoa as possible to the egg. However, in mammals, the role appears to be recruitment of a selective population of capacitated ('ripe') spermatozoa to fertilize the egg.  (+info)

Cloning and characterization of chemotaxis genes in Pseudomonas aeruginosa. (8/5128)

Two chemotaxis-defective mutants of Pseudomonas aeruginosa, designated PC3 and PC4, were selected by the swarm plate method after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. These mutants were not complemented by the P. aeruginosa cheY and cheZ genes, which had been previously cloned (Masduki et al., J. Bacteriol., 177, 948-952, 1995). DNA sequences downstream of the cheY and cheZ genes were able to complement PC3 but not PC4. Sequence analysis of a 9.7-kb region directly downstream of the cheZ gene found three chemotaxis genes, cheA, cheB, and cheW, and seven unknown open reading frames (ORFs). The predicted translation products of the cheA, cheB, and cheW genes showed 33, 36, and 31% amino acid identity with Escherichia coli CheA, CheB, and CheW, respectively. Two of the unknown ORFs, ORF1 and ORF2, encoded putative polypeptides that resembled Bacillus subtilis MotA (40% amino acid identity) and MotB (34% amino acid identity) proteins, respectively. Although P. aeruginosa was found to have proteins similar to the enteric chemotaxis proteins CheA, CheB, CheW, CheY, and CheZ, the gene encoding a CheR homologue did not reside in the chemotaxis gene cluster. The P. aeruginosa cheR gene could be cloned by phenotypic complementation of the PC4 mutant. This gene was located at least 1,800 kb away from the chemotaxis gene cluster and encoded a putative polypeptide that had 32% amino acid identity with E. coli CheR.  (+info)

Chemotaxis is a term used in biology and medicine to describe the movement of an organism or cell towards or away from a chemical stimulus. This process plays a crucial role in various biological phenomena, including immune responses, wound healing, and the development and progression of diseases such as cancer.

In chemotaxis, cells can detect and respond to changes in the concentration of specific chemicals, known as chemoattractants or chemorepellents, in their environment. These chemicals bind to receptors on the cell surface, triggering a series of intracellular signaling events that ultimately lead to changes in the cytoskeleton and directed movement of the cell towards or away from the chemical gradient.

For example, during an immune response, white blood cells called neutrophils use chemotaxis to migrate towards sites of infection or inflammation, where they can attack and destroy invading pathogens. Similarly, cancer cells can use chemotaxis to migrate towards blood vessels and metastasize to other parts of the body.

Understanding chemotaxis is important for developing new therapies and treatments for a variety of diseases, including cancer, infectious diseases, and inflammatory disorders.

Chemotaxis, Leukocyte is the movement of leukocytes (white blood cells) towards a higher concentration of a particular chemical substance, known as a chemotactic factor. This process plays a crucial role in the immune system's response to infection and injury.

When there is an infection or tissue damage, certain cells release chemotactic factors, which are small molecules or proteins that can attract leukocytes to the site of inflammation. Leukocytes have receptors on their surface that can detect these chemotactic factors and move towards them through a process called chemotaxis.

Once they reach the site of inflammation, leukocytes can help eliminate pathogens or damaged cells by phagocytosis (engulfing and destroying) or releasing toxic substances that kill the invading microorganisms. Chemotaxis is an essential part of the immune system's defense mechanisms and helps to maintain tissue homeostasis and prevent the spread of infection.

Chemotactic factors are substances that attract or repel cells, particularly immune cells, by stimulating directional movement in response to a chemical gradient. These factors play a crucial role in the body's immune response and inflammation process. They include:

1. Chemokines: A family of small signaling proteins that direct the migration of immune cells to sites of infection or tissue damage.
2. Cytokines: A broad category of signaling molecules that mediate and regulate immunity, inflammation, and hematopoiesis. Some cytokines can also act as chemotactic factors.
3. Complement components: Cleavage products of the complement system can attract immune cells to the site of infection or tissue injury.
4. Growth factors: Certain growth factors, like colony-stimulating factors (CSFs), can stimulate the migration and proliferation of specific cell types.
5. Lipid mediators: Products derived from arachidonic acid metabolism, such as leukotrienes and prostaglandins, can also act as chemotactic factors.
6. Formyl peptides: Bacterial-derived formylated peptides can attract and activate neutrophils during an infection.
7. Extracellular matrix (ECM) components: Fragments of ECM proteins, like collagen and fibronectin, can serve as chemotactic factors for immune cells.

These factors help orchestrate the immune response by guiding the movement of immune cells to specific locations in the body where they are needed.

Neutrophils are a type of white blood cell that are part of the immune system's response to infection. They are produced in the bone marrow and released into the bloodstream where they circulate and are able to move quickly to sites of infection or inflammation in the body. Neutrophils are capable of engulfing and destroying bacteria, viruses, and other foreign substances through a process called phagocytosis. They are also involved in the release of inflammatory mediators, which can contribute to tissue damage in some cases. Neutrophils are characterized by the presence of granules in their cytoplasm, which contain enzymes and other proteins that help them carry out their immune functions.

'Dictyostelium' is a genus of social amoebae that are commonly found in soil and decaying organic matter. These microscopic organisms have a unique life cycle, starting as individual cells that feed on bacteria. When food becomes scarce, the cells undergo a developmental process where they aggregate together to form a multicellular slug-like structure called a pseudoplasmodium or grex. This grex then moves and differentiates into a fruiting body that can release spores for further reproduction.

Dictyostelium discoideum is the most well-studied species in this genus, serving as a valuable model organism for research in various fields such as cell biology, developmental biology, and evolutionary biology. The study of Dictyostelium has contributed significantly to our understanding of fundamental biological processes like chemotaxis, signal transduction, and cell differentiation.

N-Formylmethionine Leucyl-Phenylalanine (fMLP) is not a medical condition, but rather a synthetic peptide that is often used in laboratory settings for research purposes. It is a formylated methionine residue linked to a leucine and phenylalanine tripeptide.

fMLP is a potent chemoattractant for certain types of white blood cells, including neutrophils and monocytes. When these cells encounter fMLP, they are stimulated to migrate towards the source of the peptide and release various inflammatory mediators. As such, fMLP is often used in studies of inflammation, immune cell function, and signal transduction pathways.

It's important to note that while fMLP has important research applications, it is not a substance that would be encountered or used in clinical medicine.

Cell movement, also known as cell motility, refers to the ability of cells to move independently and change their location within tissue or inside the body. This process is essential for various biological functions, including embryonic development, wound healing, immune responses, and cancer metastasis.

There are several types of cell movement, including:

1. **Crawling or mesenchymal migration:** Cells move by extending and retracting protrusions called pseudopodia or filopodia, which contain actin filaments. This type of movement is common in fibroblasts, immune cells, and cancer cells during tissue invasion and metastasis.
2. **Amoeboid migration:** Cells move by changing their shape and squeezing through tight spaces without forming protrusions. This type of movement is often observed in white blood cells (leukocytes) as they migrate through the body to fight infections.
3. **Pseudopodial extension:** Cells extend pseudopodia, which are temporary cytoplasmic projections containing actin filaments. These protrusions help the cell explore its environment and move forward.
4. **Bacterial flagellar motion:** Bacteria use a whip-like structure called a flagellum to propel themselves through their environment. The rotation of the flagellum is driven by a molecular motor in the bacterial cell membrane.
5. **Ciliary and ependymal movement:** Ciliated cells, such as those lining the respiratory tract and fallopian tubes, have hair-like structures called cilia that beat in coordinated waves to move fluids or mucus across the cell surface.

Cell movement is regulated by a complex interplay of signaling pathways, cytoskeletal rearrangements, and adhesion molecules, which enable cells to respond to environmental cues and navigate through tissues.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Chemokine (C-X-C motif) ligand 12 (CXCL12), also known as stromal cell-derived factor 1 (SDF-1), is a small signaling protein belonging to the chemokine family. Chemokines are a group of cytokines, or signaling molecules, that play important roles in immune responses and inflammation by recruiting and activating various immune cells.

CXCL12 is produced by several types of cells, including stromal cells, endothelial cells, and certain immune cells. It exerts its effects by binding to a specific receptor called C-X-C chemokine receptor type 4 (CXCR4), which is found on the surface of various cell types, including immune cells, stem cells, and some cancer cells.

The CXCL12-CXCR4 axis plays crucial roles in various physiological processes, such as embryonic development, tissue homeostasis, hematopoiesis (the formation of blood cells), and neurogenesis (the formation of neurons). Additionally, this signaling pathway has been implicated in several pathological conditions, including cancer metastasis, inflammatory diseases, and HIV infection.

In summary, Chemokine CXCL12 is a small signaling protein that binds to the CXCR4 receptor and plays essential roles in various physiological processes and pathological conditions.

Bacterial proteins are a type of protein that are produced by bacteria as part of their structural or functional components. These proteins can be involved in various cellular processes, such as metabolism, DNA replication, transcription, and translation. They can also play a role in bacterial pathogenesis, helping the bacteria to evade the host's immune system, acquire nutrients, and multiply within the host.

Bacterial proteins can be classified into different categories based on their function, such as:

1. Enzymes: Proteins that catalyze chemical reactions in the bacterial cell.
2. Structural proteins: Proteins that provide structural support and maintain the shape of the bacterial cell.
3. Signaling proteins: Proteins that help bacteria to communicate with each other and coordinate their behavior.
4. Transport proteins: Proteins that facilitate the movement of molecules across the bacterial cell membrane.
5. Toxins: Proteins that are produced by pathogenic bacteria to damage host cells and promote infection.
6. Surface proteins: Proteins that are located on the surface of the bacterial cell and interact with the environment or host cells.

Understanding the structure and function of bacterial proteins is important for developing new antibiotics, vaccines, and other therapeutic strategies to combat bacterial infections.

Chemokines are a family of small signaling proteins that are involved in immune regulation and inflammation. They mediate their effects by interacting with specific cell surface receptors, leading to the activation and migration of various types of immune cells. Chemokines can be divided into four subfamilies based on the arrangement of conserved cysteine residues near the N-terminus: CXC, CC, C, and CX3C.

CXC chemokines are characterized by the presence of a single amino acid (X) between the first two conserved cysteine residues. They play important roles in the recruitment and activation of neutrophils, which are critical effector cells in the early stages of inflammation. CXC chemokines can be further divided into two subgroups based on the presence or absence of a specific amino acid sequence (ELR motif) near the N-terminus: ELR+ and ELR-.

ELR+ CXC chemokines, such as IL-8, are potent chemoattractants for neutrophils and play important roles in the recruitment of these cells to sites of infection or injury. They bind to and activate the CXCR1 and CXCR2 receptors on the surface of neutrophils, leading to their migration towards the source of the chemokine.

ELR- CXC chemokines, such as IP-10 and MIG, are involved in the recruitment of T cells and other immune cells to sites of inflammation. They bind to and activate different receptors, such as CXCR3, on the surface of these cells, leading to their migration towards the source of the chemokine.

Overall, CXC chemokines play important roles in the regulation of immune responses and inflammation, and dysregulation of their expression or activity has been implicated in a variety of diseases, including cancer, autoimmune disorders, and infectious diseases.

Formyl peptide receptors (FPRs) are a type of G protein-coupled receptors that play a crucial role in the innate immune system. They are expressed on various cells including neutrophils, monocytes, and macrophages. FPRs recognize and respond to formylated peptides derived from bacteria, mitochondria, and host proteins during cell damage or stress. Activation of FPRs triggers a variety of cellular responses, such as chemotaxis, phagocytosis, and release of inflammatory mediators, which help to eliminate invading pathogens and promote tissue repair. There are three subtypes of human FPRs (FPR1, FPR2, and FPR3) that have distinct ligand specificities and functions in the immune response.

Complement C5a is a protein fragment that is generated during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by tagging them for destruction and attracting immune cells to the site of infection or injury.

C5a is formed when the fifth component of the complement system (C5) is cleaved into two smaller fragments, C5a and C5b, during the complement activation cascade. C5a is a potent pro-inflammatory mediator that can attract and activate various immune cells, such as neutrophils, monocytes, and eosinophils, to the site of infection or injury. It can also increase vascular permeability, promote the release of histamine, and induce the production of reactive oxygen species, all of which contribute to the inflammatory response.

However, excessive or uncontrolled activation of the complement system and generation of C5a can lead to tissue damage and inflammation, contributing to the pathogenesis of various diseases, such as sepsis, acute respiratory distress syndrome (ARDS), and autoimmune disorders. Therefore, targeting C5a or its receptors has been explored as a potential therapeutic strategy for these conditions.

Chemokine receptors are a type of G protein-coupled receptor (GPCR) that bind to chemokines, which are small signaling proteins involved in immune cell trafficking and inflammation. These receptors play a crucial role in the regulation of immune responses, hematopoiesis, and development. Chemokine receptors are expressed on the surface of various cells, including leukocytes, endothelial cells, and fibroblasts. Upon binding to their respective chemokines, these receptors activate intracellular signaling pathways that lead to cell migration, activation, or proliferation. There are several subfamilies of chemokine receptors, including CXCR, CCR, CX3CR, and XCR, each with distinct specificities for different chemokines. Dysregulation of chemokine receptor signaling has been implicated in various pathological conditions, such as autoimmune diseases, cancer, and viral infections.

Interleukin-8 (IL-8) receptors are a type of G protein-coupled receptor that bind to and are activated by the cytokine IL-8. There are two main types of IL-8 receptors, known as CXCR1 and CXCR2.

IL-8B, also known as CXCR2, is a gene that encodes for the Interleukin-8 receptor B. This receptor is found on the surface of various cells, including neutrophils, monocytes, and endothelial cells. It plays a crucial role in the immune response, particularly in the recruitment and activation of neutrophils to sites of infection or inflammation.

IL-8B has a high affinity for IL-8 and other related chemokines, such as CXCL1, CXCL5, and CXCL7. Upon binding to its ligand, IL-8B activates various signaling pathways that lead to the mobilization and migration of neutrophils towards the site of inflammation. This process is critical for the elimination of invading pathogens and the resolution of inflammation.

However, excessive or prolonged activation of IL-8B has been implicated in various pathological conditions, including chronic inflammation, cancer, and autoimmune diseases. Therefore, targeting IL-8B with therapeutic agents has emerged as a promising strategy for the treatment of these conditions.

Flagella are long, thin, whip-like structures that some types of cells use to move themselves around. They are made up of a protein called tubulin and are surrounded by a membrane. In bacteria, flagella rotate like a propeller to push the cell through its environment. In eukaryotic cells (cells with a true nucleus), such as sperm cells or certain types of algae, flagella move in a wave-like motion to achieve locomotion. The ability to produce flagella is called flagellation.

Cell migration inhibition refers to the process or agents that restrict the movement of cells, particularly in the context of cancer metastasis. Cell migration is a critical biological process involved in various physiological and pathological conditions, including embryonic development, wound healing, and tumor cell dissemination. Inhibiting cell migration can help prevent the spread of cancer to distant organs, thereby improving treatment outcomes and patient survival rates.

Various factors and mechanisms contribute to cell migration inhibition, such as:

1. Modulation of signaling pathways: Cell migration is regulated by complex intracellular signaling networks that control cytoskeletal rearrangements, adhesion molecules, and other components required for cell motility. Inhibiting specific signaling proteins or pathways can suppress cell migration.
2. Extracellular matrix (ECM) modifications: The ECM provides structural support and biochemical cues that guide cell migration. Altering the composition or organization of the ECM can hinder cell movement.
3. Inhibition of adhesion molecules: Cell-cell and cell-matrix interactions are mediated by adhesion molecules, such as integrins and cadherins. Blocking these molecules can prevent cells from attaching to their surroundings and migrating.
4. Targeting cytoskeletal components: The cytoskeleton is responsible for the mechanical forces required for cell migration. Inhibiting cytoskeletal proteins, such as actin or tubulin, can impair cell motility.
5. Use of pharmacological agents: Several drugs and compounds have been identified to inhibit cell migration, either by targeting specific molecules or indirectly affecting the overall cellular environment. These agents include chemotherapeutic drugs, natural compounds, and small molecule inhibitors.

Understanding the mechanisms underlying cell migration inhibition can provide valuable insights into developing novel therapeutic strategies for cancer treatment and other diseases involving aberrant cell migration.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

Interleukin-8 (IL-8) receptors are a type of cell surface receptor that bind to and are activated by the cytokine IL-8. There are two main types of IL-8 receptors, known as CXCR1 and CXCR2. Both of these receptors belong to the G protein-coupled receptor (GPCR) family and play important roles in the immune response, particularly in the recruitment and activation of neutrophils, a type of white blood cell that helps to fight infection.

IL-8A, also known as CXCR1, is a specific subtype of IL-8 receptor. It is a 354-amino acid protein that is expressed on the surface of many different types of cells, including neutrophils, monocytes, and certain tumor cells. When IL-8 binds to CXCR1, it activates a variety of signaling pathways within the cell that lead to changes in gene expression, cell activation, and chemotaxis (directed movement) towards the source of IL-8.

CXCR1 plays an important role in the immune response to bacterial and fungal infections, as well as in the development and progression of certain inflammatory diseases and cancers. It is also a target for drug development, particularly in the areas of cancer therapy and inflammatory disease.

Bacterial physiological phenomena refer to the various functional processes and activities that occur within bacteria, which are necessary for their survival, growth, and reproduction. These phenomena include:

1. Metabolism: This is the process by which bacteria convert nutrients into energy and cellular components. It involves a series of chemical reactions that break down organic compounds such as carbohydrates, lipids, and proteins to produce energy in the form of ATP (adenosine triphosphate).
2. Respiration: This is the process by which bacteria use oxygen to convert organic compounds into carbon dioxide and water, releasing energy in the form of ATP. Some bacteria can also perform anaerobic respiration, using alternative electron acceptors such as nitrate or sulfate instead of oxygen.
3. Fermentation: This is a type of anaerobic metabolism in which bacteria convert organic compounds into simpler molecules, releasing energy in the form of ATP. Unlike respiration, fermentation does not require an external electron acceptor.
4. Motility: Many bacteria are capable of moving independently, using various mechanisms such as flagella or twitching motility. This allows them to move towards favorable environments and away from harmful ones.
5. Chemotaxis: Bacteria can sense and respond to chemical gradients in their environment, allowing them to move towards attractants and away from repellents.
6. Quorum sensing: Bacteria can communicate with each other using signaling molecules called autoinducers. When the concentration of autoinducers reaches a certain threshold, the bacteria can coordinate their behavior, such as initiating biofilm formation or producing virulence factors.
7. Sporulation: Some bacteria can form spores, which are highly resistant to heat, radiation, and chemicals. Spores can remain dormant for long periods of time and germinate when conditions are favorable.
8. Biofilm formation: Bacteria can form complex communities called biofilms, which are composed of cells embedded in a matrix of extracellular polymeric substances (EPS). Biofilms can provide protection from environmental stressors and host immune responses.
9. Cell division: Bacteria reproduce by binary fission, where the cell divides into two identical daughter cells. This process is regulated by various cell cycle checkpoints and can be influenced by environmental factors such as nutrient availability.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

Monocytes are a type of white blood cell that are part of the immune system. They are large cells with a round or oval shape and a nucleus that is typically indented or horseshoe-shaped. Monocytes are produced in the bone marrow and then circulate in the bloodstream, where they can differentiate into other types of immune cells such as macrophages and dendritic cells.

Monocytes play an important role in the body's defense against infection and tissue damage. They are able to engulf and digest foreign particles, microorganisms, and dead or damaged cells, which helps to clear them from the body. Monocytes also produce cytokines, which are signaling molecules that help to coordinate the immune response.

Elevated levels of monocytes in the bloodstream can be a sign of an ongoing infection, inflammation, or other medical conditions such as cancer or autoimmune disorders.

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

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

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

Interleukin-8 (IL-8) is a type of cytokine, which is a small signaling protein involved in immune response and inflammation. IL-8 is also known as neutrophil chemotactic factor or NCF because it attracts neutrophils, a type of white blood cell, to the site of infection or injury.

IL-8 is produced by various cells including macrophages, epithelial cells, and endothelial cells in response to bacterial or inflammatory stimuli. It acts by binding to specific receptors called CXCR1 and CXCR2 on the surface of neutrophils, which triggers a series of intracellular signaling events leading to neutrophil activation, migration, and degranulation.

IL-8 plays an important role in the recruitment of neutrophils to the site of infection or tissue damage, where they can phagocytose and destroy invading microorganisms. However, excessive or prolonged production of IL-8 has been implicated in various inflammatory diseases such as chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, and cancer.

C-X-C chemokine receptor type 4 (CXCR4) is a type of protein found on the surface of some cells, including white blood cells, and is a type of G protein-coupled receptor (GPCR). CXCR4 binds specifically to the chemokine ligand CXCL12 (also known as stromal cell-derived factor 1, or SDF-1), which plays a crucial role in the trafficking and homing of immune cells, particularly hematopoietic stem cells and lymphocytes. The binding of CXCL12 to CXCR4 triggers various intracellular signaling pathways that regulate cell migration, proliferation, survival, and differentiation.

In addition to its role in the immune system, CXCR4 has been implicated in several physiological and pathological processes, such as embryonic development, neurogenesis, angiogenesis, cancer metastasis, and HIV infection. In cancer, the overexpression of CXCR4 or increased levels of its ligand CXCL12 have been associated with poor prognosis, tumor growth, and metastasis in various types of malignancies, including breast, lung, prostate, colon, and ovarian cancers. In HIV infection, the CXCR4 coreceptor, together with CD4, facilitates viral entry into host cells, particularly during the later stages of the disease when the virus shifts its preference from CCR5 to CXCR4 as a coreceptor.

In summary, CXCR4 is a cell-surface receptor that binds specifically to the chemokine ligand CXCL12 and plays essential roles in immune cell trafficking, hematopoiesis, cancer metastasis, and HIV infection.

Chemoreceptor cells are specialized sensory neurons that detect and respond to chemical changes in the internal or external environment. They play a crucial role in maintaining homeostasis within the body by converting chemical signals into electrical impulses, which are then transmitted to the central nervous system for further processing and response.

There are two main types of chemoreceptor cells:

1. Oxygen Chemoreceptors: These cells are located in the carotid bodies near the bifurcation of the common carotid artery and in the aortic bodies close to the aortic arch. They monitor the levels of oxygen, carbon dioxide, and pH in the blood and respond to decreases in oxygen concentration or increases in carbon dioxide and hydrogen ions (indicating acidity) by increasing their firing rate. This signals the brain to increase respiratory rate and depth, thereby restoring normal oxygen levels.

2. Taste Cells: These chemoreceptor cells are found within the taste buds of the tongue and other areas of the oral cavity. They detect specific tastes (salty, sour, sweet, bitter, and umami) by interacting with molecules from food. When a tastant binds to receptors on the surface of a taste cell, it triggers a series of intracellular signaling events that ultimately lead to the generation of an action potential. This information is then relayed to the brain, where it is interpreted as taste sensation.

In summary, chemoreceptor cells are essential for maintaining physiological balance by detecting and responding to chemical stimuli in the body. They play a critical role in regulating vital functions such as respiration and digestion.

Pseudopodia are temporary projections or extensions of the cytoplasm in certain types of cells, such as white blood cells (leukocytes) and some amoebas. They are used for locomotion and engulfing particles or other cells through a process called phagocytosis.

In simpler terms, pseudopodia are like "false feet" that some cells use to move around and interact with their environment. The term comes from the Greek words "pseudes," meaning false, and "podos," meaning foot.

Amino acid receptors are a type of cell surface receptor that bind to specific amino acids or peptides and trigger intracellular signaling pathways. These receptors play important roles in various physiological processes, including neurotransmission, hormone signaling, and regulation of metabolism.

There are several types of amino acid receptors, including:

1. G protein-coupled receptors (GPCRs): These receptors are activated by amino acids such as γ-aminobutyric acid (GABA), glycine, and glutamate, and play important roles in neurotransmission and neuromodulation.
2. Ionotropic receptors: These receptors are ligand-gated ion channels that are activated by amino acids such as glutamate and glycine. They play critical roles in synaptic transmission and neural excitability.
3. Enzyme-linked receptors: These receptors activate intracellular signaling pathways through the activation of enzymes, such as receptor tyrosine kinases (RTKs). Some amino acid receptors, such as the insulin-like growth factor 1 receptor (IGF-1R), are RTKs that play important roles in cell growth, differentiation, and metabolism.
4. Intracellular receptors: These receptors are located within the cell and bind to amino acids or peptides that have been transported into the cell. For example, the peroxisome proliferator-activated receptors (PPARs) are intracellular receptors that bind to fatty acids and play important roles in lipid metabolism and inflammation.

Overall, amino acid receptors are critical components of cell signaling pathways and play important roles in various physiological processes. Dysregulation of these receptors has been implicated in a variety of diseases, including neurological disorders, cancer, and metabolic disorders.

Chemokines are a family of small proteins that are involved in immune responses and inflammation. They mediate the chemotaxis (directed migration) of various cells, including leukocytes (white blood cells). Chemokines are classified into four major subfamilies based on the arrangement of conserved cysteine residues near the amino terminus: CXC, CC, C, and CX3C.

CC chemokines, also known as β-chemokines, are characterized by the presence of two adjacent cysteine residues near their N-terminal end. There are 27 known human CC chemokines, including MCP-1 (monocyte chemoattractant protein-1), RANTES (regulated on activation, normal T cell expressed and secreted), and eotaxin.

CC chemokines play important roles in the recruitment of immune cells to sites of infection or injury, as well as in the development and maintenance of immune responses. They bind to specific G protein-coupled receptors (GPCRs) on the surface of target cells, leading to the activation of intracellular signaling pathways that regulate cell migration, proliferation, and survival.

Dysregulation of CC chemokines and their receptors has been implicated in various inflammatory and autoimmune diseases, as well as in cancer. Therefore, targeting CC chemokine-mediated signaling pathways has emerged as a promising therapeutic strategy for the treatment of these conditions.

Leukotriene B4 (LTB4) is a type of lipid mediator called eicosanoid, which is derived from arachidonic acid through the 5-lipoxygenase pathway. It is primarily produced by neutrophils, eosinophils, monocytes, and macrophages in response to various stimuli such as infection, inflammation, or injury. LTB4 acts as a potent chemoattractant and activator of these immune cells, playing a crucial role in the recruitment and activation of neutrophils during acute inflammatory responses. It also enhances the adhesion of leukocytes to endothelial cells, contributing to the development of tissue damage and edema. Dysregulation of LTB4 production has been implicated in several pathological conditions, including asthma, atherosclerosis, and cancer.

Chemokines are a family of small cytokines, or signaling proteins, that are secreted by cells and play an important role in the immune system. They are chemotactic, meaning they can attract and guide the movement of various immune cells to specific locations within the body. Chemokines do this by binding to G protein-coupled receptors on the surface of target cells, initiating a signaling cascade that leads to cell migration.

There are four main subfamilies of chemokines, classified based on the arrangement of conserved cysteine residues near the amino terminus: CXC, CC, C, and CX3C. Different chemokines have specific roles in inflammation, immune surveillance, hematopoiesis, and development. Dysregulation of chemokine function has been implicated in various diseases, including autoimmune disorders, infections, and cancer.

In summary, Chemokines are a group of signaling proteins that play a crucial role in the immune system by directing the movement of immune cells to specific locations within the body, thus helping to coordinate the immune response.

Actin is a type of protein that forms part of the contractile apparatus in muscle cells, and is also found in various other cell types. It is a globular protein that polymerizes to form long filaments, which are important for many cellular processes such as cell division, cell motility, and the maintenance of cell shape. In muscle cells, actin filaments interact with another type of protein called myosin to enable muscle contraction. Actins can be further divided into different subtypes, including alpha-actin, beta-actin, and gamma-actin, which have distinct functions and expression patterns in the body.

Chemokine (C-C motif) ligand 2, also known as monocyte chemoattractant protein-1 (MCP-1), is a small signaling protein that belongs to the chemokine family. Chemokines are a group of cytokines, or regulatory proteins, that play important roles in immune responses and inflammation by recruiting various immune cells to sites of infection or injury.

CCL2 specifically acts as a chemoattractant for monocytes, memory T cells, and dendritic cells, guiding them to migrate towards the source of infection or tissue damage. It does this by binding to its receptor, CCR2, which is expressed on the surface of these immune cells.

CCL2 has been implicated in several pathological conditions, including atherosclerosis, rheumatoid arthritis, and various cancers, where it contributes to the recruitment of immune cells that can exacerbate tissue damage or promote tumor growth and metastasis. Therefore, targeting CCL2 or its signaling pathways has emerged as a potential therapeutic strategy for these diseases.

Cell adhesion refers to the binding of cells to extracellular matrices or to other cells, a process that is fundamental to the development, function, and maintenance of multicellular organisms. Cell adhesion is mediated by various cell surface receptors, such as integrins, cadherins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs), which interact with specific ligands in the extracellular environment. These interactions lead to the formation of specialized junctions, such as tight junctions, adherens junctions, and desmosomes, that help to maintain tissue architecture and regulate various cellular processes, including proliferation, differentiation, migration, and survival. Disruptions in cell adhesion can contribute to a variety of diseases, including cancer, inflammation, and degenerative disorders.

Cell polarity refers to the asymmetric distribution of membrane components, cytoskeleton, and organelles in a cell. This asymmetry is crucial for various cellular functions such as directed transport, cell division, and signal transduction. The plasma membrane of polarized cells exhibits distinct domains with unique protein and lipid compositions that define apical, basal, and lateral surfaces of the cell.

In epithelial cells, for example, the apical surface faces the lumen or external environment, while the basolateral surface interacts with other cells or the extracellular matrix. The establishment and maintenance of cell polarity are regulated by various factors including protein complexes, lipids, and small GTPases. Loss of cell polarity has been implicated in several diseases, including cancer and neurological disorders.

Methylation, in the context of genetics and epigenetics, refers to the addition of a methyl group (CH3) to a molecule, usually to the nitrogenous base of DNA or to the side chain of amino acids in proteins. In DNA methylation, this process typically occurs at the 5-carbon position of cytosine residues that precede guanine residues (CpG sites) and is catalyzed by enzymes called DNA methyltransferases (DNMTs).

DNA methylation plays a crucial role in regulating gene expression, genomic imprinting, X-chromosome inactivation, and suppression of repetitive elements. Hypermethylation or hypomethylation of specific genes can lead to altered gene expression patterns, which have been associated with various human diseases, including cancer.

In summary, methylation is a fundamental epigenetic modification that influences genomic stability, gene regulation, and cellular function by introducing methyl groups to DNA or proteins.

N-Formylmethionine (fMet) is not a medical term per se, but rather a biochemical term. It is the formylated derivative of methionine, which is one of the twenty standard amino acids, and it plays a crucial role in the initiation of protein synthesis in prokaryotes and organelles of eukaryotic cells, such as mitochondria and chloroplasts.

In the context of medical research or clinical laboratory reports, you might encounter fMet in relation to bacterial infections, proteomics, or mitochondrial function. For example, formylated methionine residues on bacterial peptides can stimulate immune responses and are recognized by specific receptors on human immune cells, which can have implications for understanding infectious diseases and inflammation.

To provide a concise definition:
N-Formylmethionine (fMet) is the formylated derivative of methionine, primarily known for its role as the initiator amino acid in protein synthesis in prokaryotes and certain organelles of eukaryotic cells.

CCR2 (C-C chemokine receptor type 2) is a type of protein found on the surface of certain immune cells, including monocytes and memory T cells. It is a type of G protein-coupled receptor that binds to specific chemokines, which are small signaling proteins that help regulate the movement of immune cells throughout the body.

CCR2 plays an important role in the immune response by mediating the migration of monocytes and other immune cells to sites of inflammation or injury. When a chemokine binds to CCR2, it triggers a series of intracellular signaling events that cause the cell to move towards the source of the chemokine.

In addition to its role in the immune response, CCR2 has been implicated in various disease processes, including atherosclerosis, rheumatoid arthritis, and cancer metastasis. In these contexts, CCR2 antagonists have been explored as potential therapeutic agents to block the recruitment of immune cells and reduce inflammation or tumor growth.

Chemokine (C-C motif) ligand 19 (CCL19), also known as macrophage inflammatory protein-3 beta (MIP-3β) or exodus-3, is a small signaling protein that belongs to the CC chemokine family. Chemokines are a group of cytokines, or cell signaling molecules, that play crucial roles in immunity and inflammation by directing the migration of various immune cells to sites of infection, injury, or inflammation through a process called chemotaxis.

CCL19 is primarily produced by mature dendritic cells, a type of antigen-presenting cell that plays a key role in initiating and regulating adaptive immunity. CCL19 attracts various immune cells expressing its receptor, CCR7, including T cells, B cells, and dendritic cells, to the T cell zones of secondary lymphoid organs such as lymph nodes and spleen. This facilitates the encounter between antigen-presenting cells and T cells, leading to the activation of T cells and the generation of adaptive immune responses.

In addition to its role in immunity and inflammation, CCL19 has been implicated in various physiological and pathological processes, such as lymphoid organ development, angiogenesis, and cancer metastasis. Dysregulation of CCL19 expression or function has been associated with several diseases, including autoimmune disorders, chronic inflammation, and malignancies.

Phosphatidylinositol 3-Kinases (PI3Ks) are a family of enzymes that play a crucial role in intracellular signal transduction. They phosphorylate the 3-hydroxyl group of the inositol ring in phosphatidylinositol and its derivatives, which results in the production of second messengers that regulate various cellular processes such as cell growth, proliferation, differentiation, motility, and survival.

PI3Ks are divided into three classes based on their structure and substrate specificity. Class I PI3Ks are further subdivided into two categories: class IA and class IB. Class IA PI3Ks are heterodimers consisting of a catalytic subunit (p110α, p110β, or p110δ) and a regulatory subunit (p85α, p85β, p55γ, or p50γ). They are primarily activated by receptor tyrosine kinases and G protein-coupled receptors. Class IB PI3Ks consist of a catalytic subunit (p110γ) and a regulatory subunit (p101 or p84/87). They are mainly activated by G protein-coupled receptors.

Dysregulation of PI3K signaling has been implicated in various human diseases, including cancer, diabetes, and autoimmune disorders. Therefore, PI3Ks have emerged as important targets for drug development in these areas.

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.

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

Examples of biological models include:

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

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

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.

CCR1 (C-C chemokine receptor type 1) is a type of protein found on the surface of certain immune cells, including monocytes, neutrophils, and dendritic cells. It belongs to the family of G protein-coupled receptors that play a crucial role in the immune system's response to infection and inflammation.

CCR1 receptors bind to specific chemokines, which are small signaling proteins that help regulate the movement of immune cells throughout the body. When a chemokine binds to the CCR1 receptor, it triggers a series of intracellular signals that ultimately lead to the activation and migration of immune cells to the site of infection or inflammation.

CCR1 has been implicated in various physiological and pathological processes, including the development of atherosclerosis, rheumatoid arthritis, multiple sclerosis, and certain types of cancer. As such, CCR1 has become a target for the development of new therapies aimed at modulating the immune response in these conditions.

Leukocyte cell migration assays are in vitro tests used to measure the movement or migration of leukocytes (white blood cells) through a porous membrane from one chamber to another. These assays are commonly used in immunology and inflammation research to study the mechanisms that regulate leukocyte migration, which is an important process in the immune response.

There are several types of leukocyte cell migration assays, including Boyden chamber assays, Transwell migration assays, and Zigmond chamber assays. These assays typically involve placing leukocytes in the upper chamber of a device separated from the lower chamber by a porous membrane. The lower chamber contains a chemoattractant, such as a chemokine or bacterial product, which stimulates the migration of the leukocytes through the membrane to the lower chamber.

The number of leukocytes that migrate to the lower chamber is then measured and used to calculate the rate of migration. The assay can be modified to study different aspects of leukocyte migration, such as the role of specific receptors or signaling pathways, by adding inhibitors or blocking antibodies to the upper chamber.

Overall, leukocyte cell migration assays are a valuable tool for studying the mechanisms that regulate leukocyte migration and for identifying potential therapeutic targets for inflammatory diseases.

Rac (Ras-related C3 botulinum toxin substrate) GTP-binding proteins are a subfamily of the Rho family of small GTPases, which function as molecular switches that regulate various cellular processes, including actin cytoskeleton organization, cell adhesion, and gene transcription.

Rac GTP-binding proteins cycle between an inactive GDP-bound state and an active GTP-bound state. When Rac is in its active state, it interacts with downstream effectors to regulate various signaling pathways that control cell behavior. Activation of Rac promotes the formation of lamellipodia and membrane ruffles, which are important for cell migration and invasion.

Rac GTP-binding proteins have been implicated in a variety of physiological and pathological processes, including embryonic development, immune function, and cancer. Dysregulation of Rac signaling has been associated with various diseases, such as inflammatory disorders, neurological disorders, and cancer. Therefore, understanding the regulation and function of Rac GTP-binding proteins is crucial for developing therapeutic strategies to target these diseases.

Chemokine (C-C motif) ligand 5, also known as RANTES (Regulated on Activation, Normal T cell Expressed and Secreted), is a chemokine that plays a crucial role in the immune system. It is a small signaling protein that attracts and activates immune cells, such as leukocytes, to the sites of infection or inflammation. Chemokine CCL5 binds to specific receptors on the surface of target cells, including CCR1, CCR3, and CCR5, and triggers a cascade of intracellular signaling events that result in cell migration and activation.

Chemokine CCL5 is involved in various physiological and pathological processes, such as wound healing, immune surveillance, and inflammation. It has been implicated in the pathogenesis of several diseases, including HIV infection, rheumatoid arthritis, multiple sclerosis, and cancer. In HIV infection, Chemokine CCL5 can bind to and inhibit the entry of the virus into CD4+ T cells by blocking the interaction between the viral envelope protein gp120 and the chemokine receptor CCR5. However, in advanced stages of HIV infection, the virus may develop resistance to this inhibitory effect, leading to increased viral replication and disease progression.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

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

Cyclic adenosine monophosphate (cAMP) is a key secondary messenger in many biological processes, including the regulation of metabolism, gene expression, and cellular excitability. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase and is degraded by the enzyme phosphodiesterase.

In the body, cAMP plays a crucial role in mediating the effects of hormones and neurotransmitters on target cells. For example, when a hormone binds to its receptor on the surface of a cell, it can activate a G protein, which in turn activates adenylyl cyclase to produce cAMP. The increased levels of cAMP then activate various effector proteins, such as protein kinases, which go on to regulate various cellular processes.

Overall, the regulation of cAMP levels is critical for maintaining proper cellular function and homeostasis, and abnormalities in cAMP signaling have been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Neutrophil activation refers to the process by which neutrophils, a type of white blood cell, become activated in response to a signal or stimulus, such as an infection or inflammation. This activation triggers a series of responses within the neutrophil that enable it to carry out its immune functions, including:

1. Degranulation: The release of granules containing enzymes and other proteins that can destroy microbes.
2. Phagocytosis: The engulfment and destruction of microbes through the use of reactive oxygen species (ROS) and other toxic substances.
3. Formation of neutrophil extracellular traps (NETs): A process in which neutrophils release DNA and proteins to trap and kill microbes outside the cell.
4. Release of cytokines and chemokines: Signaling molecules that recruit other immune cells to the site of infection or inflammation.

Neutrophil activation is a critical component of the innate immune response, but excessive or uncontrolled activation can contribute to tissue damage and chronic inflammation.

Complement C5 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. The complement system is a complex series of biochemical reactions that help to identify and destroy foreign substances, such as bacteria and viruses.

Complement C5 is one of several proteins in the complement system that are activated in a cascading manner in response to an activating event, such as the binding of an antibody to a pathogen. Once activated, Complement C5 can be cleaved into two smaller proteins, C5a and C5b.

C5a is a powerful anaphylatoxin, which means it can cause the release of histamine from mast cells and basophils, leading to inflammation and increased vascular permeability. It also acts as a chemoattractant, drawing immune cells to the site of infection or injury.

C5b, on the other hand, plays a role in the formation of the membrane attack complex (MAC), which is a protein structure that can punch holes in the membranes of pathogens, leading to their lysis and destruction.

Overall, Complement C5 is an important component of the immune system's response to infection and injury, helping to eliminate pathogens and damaged cells from the body.

Phagocytosis is the process by which certain cells in the body, known as phagocytes, engulf and destroy foreign particles, bacteria, or dead cells. This mechanism plays a crucial role in the immune system's response to infection and inflammation. Phagocytes, such as neutrophils, monocytes, and macrophages, have receptors on their surface that recognize and bind to specific molecules (known as antigens) on the target particles or microorganisms.

Once attached, the phagocyte extends pseudopodia (cell extensions) around the particle, forming a vesicle called a phagosome that completely encloses it. The phagosome then fuses with a lysosome, an intracellular organelle containing digestive enzymes and other chemicals. This fusion results in the formation of a phagolysosome, where the engulfed particle is broken down by the action of these enzymes, neutralizing its harmful effects and allowing for the removal of cellular debris or pathogens.

Phagocytosis not only serves as a crucial defense mechanism against infections but also contributes to tissue homeostasis by removing dead cells and debris.

Eosinophils are a type of white blood cell that play an important role in the body's immune response. They are produced in the bone marrow and released into the bloodstream, where they can travel to different tissues and organs throughout the body. Eosinophils are characterized by their granules, which contain various proteins and enzymes that are toxic to parasites and can contribute to inflammation.

Eosinophils are typically associated with allergic reactions, asthma, and other inflammatory conditions. They can also be involved in the body's response to certain infections, particularly those caused by parasites such as worms. In some cases, elevated levels of eosinophils in the blood or tissues (a condition called eosinophilia) can indicate an underlying medical condition, such as a parasitic infection, autoimmune disorder, or cancer.

Eosinophils are named for their staining properties - they readily take up eosin dye, which is why they appear pink or red under the microscope. They make up only about 1-6% of circulating white blood cells in healthy individuals, but their numbers can increase significantly in response to certain triggers.

CXCR3 is a type of chemokine receptor that is primarily expressed on the surface of certain immune cells, including T lymphocytes (a type of white blood cell involved in immune response). It belongs to the Class A orphan G protein-coupled receptors family.

CXCR3 has three known subtypes, CXCR3-A, CXCR3-B, and CXCR3-C, each with different roles in regulating immune cell functions. These receptors bind to specific chemokines, which are small signaling proteins that help direct the movement of immune cells towards sites of inflammation or infection.

The chemokines that bind to CXCR3 include CXCL9, CXCL10, and CXCL11, which are produced by various cell types in response to inflammation or injury. Once bound to these chemokines, CXCR3 activates intracellular signaling pathways that trigger a range of responses, such as cell migration, activation, and proliferation.

In the context of disease, CXCR3 has been implicated in various pathological conditions, including cancer, autoimmune diseases, and viral infections, due to its role in regulating immune cell trafficking and activation.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Lipoxins are a group of anti-inflammatory mediators that play a role in the resolution of inflammation. They are produced from arachidonic acid, a type of omega-6 fatty acid, through the action of lipoxygenase enzymes. There are several types of lipoxin receptors (ALX/FPR2 and GPR31) that have been identified, which belong to the family of G protein-coupled receptors. These receptors are expressed in various tissues, including the cardiovascular, respiratory, and gastrointestinal systems. Activation of lipoxin receptors leads to a variety of cellular responses, such as inhibition of inflammatory cytokine production, reduction of oxidative stress, and promotion of tissue repair. Dysregulation of the lipoxin signaling pathway has been implicated in several diseases, including asthma, atherosclerosis, and cancer.

HL-60 cells are a type of human promyelocytic leukemia cell line that is commonly used in scientific research. They are named after the hospital where they were first isolated, the Hospital of the University of Pennsylvania (HUP) and the 60th culture attempt to grow these cells.

HL-60 cells have the ability to differentiate into various types of blood cells, such as granulocytes, monocytes, and macrophages, when exposed to certain chemical compounds or under specific culturing conditions. This makes them a valuable tool for studying the mechanisms of cell differentiation, proliferation, and apoptosis (programmed cell death).

HL-60 cells are also often used in toxicity studies, drug discovery and development, and research on cancer, inflammation, and infectious diseases. They can be easily grown in the lab and have a stable genotype, making them ideal for use in standardized experiments and comparisons between different studies.

Chemokine (C-C motif) ligand 7 (CCL7), also known as monocyte chemotactic protein 3 (MCP-3), is a small signaling protein that belongs to the CC-chemokine family. Chemokines are a group of cytokines, or cell signaling molecules, that play crucial roles in immune responses and inflammation by recruiting various immune cells to the sites of infection or injury.

CCL7 is produced by different types of cells, including monocytes, macrophages, fibroblasts, endothelial cells, and certain tumor cells. It exerts its functions by binding to specific chemokine receptors found on the surface of target cells, primarily CCR1, CCR2, and CCR3. The primary role of CCL7 is to attract monocytes, memory T cells, and dendritic cells to the site of inflammation or injury, thereby contributing to the initiation and progression of immune responses.

CCL7 has been implicated in several pathological conditions, such as atherosclerosis, rheumatoid arthritis, cancer, and HIV infection. Its expression is often upregulated during these conditions, leading to excessive recruitment of immune cells, which can result in tissue damage and further exacerbate the disease process. Understanding the role of CCL7 in various diseases may provide insights into developing novel therapeutic strategies for their treatment.

'Azospirillum brasilense' is a species of free-living, nitrogen-fixing bacteria that is commonly found in the soil and in the roots of various plants. It belongs to the genus Azospirillum and is known for its ability to promote plant growth through a process called bacterial colonization. The bacteria colonize the root system of the plant and enhance nutrient uptake, leading to improved growth and yield. Additionally, 'Azospirillum brasilense' can convert atmospheric nitrogen into ammonia, making it available to the plants as a natural fertilizer. It is widely used in agricultural practices as a bioinoculant to improve crop productivity and sustainability.

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

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

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

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

"Spirochaeta" is a genus of spirochete bacteria, characterized by their long, spiral-shaped bodies. These bacteria are gram-negative, meaning they do not retain crystal violet dye in the Gram staining method, and are typically motile, moving by means of endoflagella located within their outer membrane. Members of this genus are found in various environments, including freshwater, marine, and terrestrial habitats. Some species are free-living, while others are parasitic or symbiotic with animals. It is important to note that the medical significance of "Spirochaeta" species is limited compared to other spirochete genera like "Treponema," which includes the bacterium causing syphilis.

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

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

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

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

Chemokine (C-C motif) ligand 21 (CCL21), also known as secondary lymphoid tissue chemokine (SLC) or exodus-2, is a type of chemokine that belongs to the CC subfamily. Chemokines are small signaling proteins that play crucial roles in regulating immune responses and inflammation by recruiting various leukocytes to sites of infection or injury through specific receptor binding.

CCL21 is primarily expressed in high endothelial venules (HEVs) within lymphoid tissues, such as lymph nodes, spleen, and Peyer's patches. It functions as a chemoattractant for immune cells like dendritic cells, T cells, and B cells, guiding them to enter the HEVs and migrate into the lymphoid organs. This process is essential for initiating adaptive immune responses against pathogens or antigens.

CCL21 exerts its effects by binding to chemokine receptors CCR7 and atypical chemokine receptor ACKR3 (also known as CXCR7). The interaction between CCL21 and these receptors triggers intracellular signaling cascades, leading to cell migration and activation. Dysregulation of CCL21 expression or function has been implicated in various pathological conditions, including autoimmune diseases, cancer, and inflammatory disorders.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Macrophage Inflammatory Proteins (MIPs) are a group of chemokines, which are a type of signaling protein involved in immune responses and inflammation. Specifically, MIPs are chemotactic cytokines that attract monocytes, macrophages, and other immune cells to sites of infection or tissue damage. They play a crucial role in the recruitment and activation of these cells during the immune response.

There are several subtypes of MIPs, including MIP-1α, MIP-1β, and MIP-3α (also known as CCL3, CCL4, and CCL20, respectively). These proteins bind to specific G protein-coupled receptors on the surface of target cells, triggering a cascade of intracellular signaling events that lead to cell migration and activation.

MIPs have been implicated in a variety of inflammatory and immune-related conditions, including autoimmune diseases, cancer, and infectious diseases. They are also being studied as potential targets for the development of new therapies aimed at modulating the immune response in these conditions.

Zymosan is a type of substance that is derived from the cell walls of yeast and some types of fungi. It's often used in laboratory research as an agent to stimulate inflammation, because it can activate certain immune cells (such as neutrophils) and cause them to release pro-inflammatory chemicals.

In medical terms, Zymosan is sometimes used as a tool for studying the immune system and inflammation in experimental settings. It's important to note that Zymosan itself is not a medical condition or disease, but rather a research reagent with potential applications in understanding human health and disease.

Pertussis toxin is an exotoxin produced by the bacterium Bordetella pertussis, which is responsible for causing whooping cough in humans. This toxin has several effects on the host organism, including:

1. Adenylyl cyclase activation: Pertussis toxin enters the host cell and modifies a specific G protein (Gαi), leading to the continuous activation of adenylyl cyclase. This results in increased levels of intracellular cAMP, which disrupts various cellular processes.
2. Inhibition of immune response: Pertussis toxin impairs the host's immune response by inhibiting the migration and function of immune cells like neutrophils and macrophages. It also interferes with antigen presentation and T-cell activation, making it difficult for the body to clear the infection.
3. Increased inflammation: The continuous activation of adenylyl cyclase by pertussis toxin leads to increased production of proinflammatory cytokines, contributing to the severe coughing fits and other symptoms associated with whooping cough.

Pertussis toxin is an essential virulence factor for Bordetella pertussis, and its effects contribute significantly to the pathogenesis of whooping cough. Vaccination against pertussis includes inactivated or genetically detoxified forms of pertussis toxin, which provide immunity without causing disease symptoms.

"Salmonella enterica" serovar "Typhimurium" is a subspecies of the bacterial species Salmonella enterica, which is a gram-negative, facultatively anaerobic, rod-shaped bacterium. It is a common cause of foodborne illness in humans and animals worldwide. The bacteria can be found in a variety of sources, including contaminated food and water, raw meat, poultry, eggs, and dairy products.

The infection caused by Salmonella Typhimurium is typically self-limiting and results in gastroenteritis, which is characterized by symptoms such as diarrhea, abdominal cramps, fever, and vomiting. However, in some cases, the infection can spread to other parts of the body and cause more severe illness, particularly in young children, older adults, and people with weakened immune systems.

Salmonella Typhimurium is a major public health concern due to its ability to cause outbreaks of foodborne illness, as well as its potential to develop antibiotic resistance. Proper food handling, preparation, and storage practices can help prevent the spread of Salmonella Typhimurium and other foodborne pathogens.

CCR3 (C-C chemokine receptor type 3) is a type of cell surface receptor that binds to specific chemokines, which are a group of small signaling proteins involved in immune responses and inflammation. CCR3 is primarily expressed on the surface of certain types of immune cells, including eosinophils, basophils, and Th2 lymphocytes.

The binding of chemokines to CCR3 triggers a series of intracellular signaling events that regulate various cellular functions, such as chemotaxis (directed migration), activation, and degranulation. CCR3 plays an important role in the pathophysiology of several diseases, including asthma, allergies, and inflammatory bowel disease, where it contributes to the recruitment and activation of immune cells that mediate tissue damage and inflammation.

Therefore, CCR3 is a potential target for the development of therapies aimed at modulating immune responses and reducing inflammation in these conditions.

CCR7 (C-C chemokine receptor type 7) is a type of protein found on the surface of certain immune cells, including T cells and dendritic cells. It is a type of G protein-coupled receptor that binds to specific chemokines, which are small signaling proteins that help regulate the migration and activation of immune cells during an immune response.

CCR7 recognizes and binds to two main chemokines, CCL19 and CCL21, which are produced by specialized cells in lymphoid organs such as lymph nodes and the spleen. When CCR7 on an immune cell binds to one of these chemokines, it triggers a series of intracellular signaling events that cause the cell to migrate towards the source of the chemokine.

This process is important for the proper functioning of the immune system, as it helps to coordinate the movement of immune cells between different tissues and organs during an immune response. For example, dendritic cells in the peripheral tissues can use CCR7 to migrate to the draining lymph nodes, where they can present antigens to T cells and help stimulate an adaptive immune response. Similarly, activated T cells can use CCR7 to migrate to the site of an infection or inflammation, where they can carry out their effector functions.

Microfluidic analytical techniques refer to the use of microfluidics, which is the manipulation of fluids in channels with dimensions of tens to hundreds of micrometers, for analytical measurements and applications. These techniques involve the integration of various functional components such as pumps, valves, mixers, and detectors onto a single chip or platform to perform chemical, biochemical, or biological analyses.

Microfluidic analytical techniques offer several advantages over traditional analytical methods, including reduced sample and reagent consumption, faster analysis times, increased sensitivity and throughput, and improved automation and portability. Examples of microfluidic analytical techniques include lab-on-a-chip devices, digital microfluidics, bead-based assays, and micro total analysis systems (μTAS). These techniques have found applications in various fields such as diagnostics, drug discovery, environmental monitoring, and food safety.

Leukocytes, also known as white blood cells (WBCs), are a crucial component of the human immune system. They are responsible for protecting the body against infections and foreign substances. Leukocytes are produced in the bone marrow and circulate throughout the body in the bloodstream and lymphatic system.

There are several types of leukocytes, including:

1. Neutrophils - These are the most abundant type of leukocyte and are primarily responsible for fighting bacterial infections. They contain enzymes that can destroy bacteria.
2. Lymphocytes - These are responsible for producing antibodies and destroying virus-infected cells, as well as cancer cells. There are two main types of lymphocytes: B-lymphocytes and T-lymphocytes.
3. Monocytes - These are the largest type of leukocyte and help to break down and remove dead or damaged tissues, as well as microorganisms.
4. Eosinophils - These play a role in fighting parasitic infections and are also involved in allergic reactions and inflammation.
5. Basophils - These release histamine and other chemicals that cause inflammation in response to allergens or irritants.

An abnormal increase or decrease in the number of leukocytes can indicate an underlying medical condition, such as an infection, inflammation, or a blood disorder.

Macrophages are a type of white blood cell that are an essential part of the immune system. They are large, specialized cells that engulf and destroy foreign substances, such as bacteria, viruses, parasites, and fungi, as well as damaged or dead cells. Macrophages are found throughout the body, including in the bloodstream, lymph nodes, spleen, liver, lungs, and connective tissues. They play a critical role in inflammation, immune response, and tissue repair and remodeling.

Macrophages originate from monocytes, which are a type of white blood cell produced in the bone marrow. When monocytes enter the tissues, they differentiate into macrophages, which have a larger size and more specialized functions than monocytes. Macrophages can change their shape and move through tissues to reach sites of infection or injury. They also produce cytokines, chemokines, and other signaling molecules that help coordinate the immune response and recruit other immune cells to the site of infection or injury.

Macrophages have a variety of surface receptors that allow them to recognize and respond to different types of foreign substances and signals from other cells. They can engulf and digest foreign particles, bacteria, and viruses through a process called phagocytosis. Macrophages also play a role in presenting antigens to T cells, which are another type of immune cell that helps coordinate the immune response.

Overall, macrophages are crucial for maintaining tissue homeostasis, defending against infection, and promoting wound healing and tissue repair. Dysregulation of macrophage function has been implicated in a variety of diseases, including cancer, autoimmune disorders, and chronic inflammatory conditions.

Monocyte chemoattractant proteins (MCPs) are a group of chemokines, which are small signaling proteins that attract immune cells to sites of infection or inflammation. Specifically, MCPs are responsible for recruiting monocytes and other immune cells to areas of tissue damage or infection.

There are several subtypes of MCPs, including MCP-1 (CCL2), MCP-2 (CCL8), MCP-3 (CCL7), and MCP-4 (CCL13). These proteins bind to specific receptors on the surface of monocytes and other immune cells, triggering a series of intracellular signaling events that result in cell migration towards the site of injury or infection.

MCPs play an important role in the pathogenesis of various inflammatory diseases, such as atherosclerosis, rheumatoid arthritis, and cancer. For example, elevated levels of MCP-1 have been associated with increased monocyte recruitment to the arterial wall, leading to the formation of plaques that can cause heart attacks and strokes. Similarly, high levels of MCPs have been found in the synovial fluid of patients with rheumatoid arthritis, contributing to joint inflammation and damage.

Overall, Monocyte chemoattractant proteins are crucial components of the immune system's response to injury and infection, but their dysregulation can contribute to the development of various diseases.

Phosphatidylinositol phosphates (PIPs) are a family of lipid molecules that play crucial roles as secondary messengers in intracellular signaling pathways. They are formed by the phosphorylation of the hydroxyl group on the inositol ring of phosphatidylinositol (PI), a fundamental component of cell membranes.

There are seven main types of PIPs, classified based on the number and position of phosphate groups attached to the inositol ring:

1. Phosphatidylinositol 4-monophosphate (PI4P) - one phosphate group at the 4th position
2. Phosphatidylinositol 5-monophosphate (PI5P) - one phosphate group at the 5th position
3. Phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2) - two phosphate groups at the 3rd and 4th positions
4. Phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) - two phosphate groups at the 3rd and 5th positions
5. Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] - two phosphate groups at the 4th and 5th positions
6. Phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] - three phosphate groups at the 3rd, 4th, and 5th positions
7. Phosphatidylinositol 3-phosphate (PI3P) - one phosphate group at the 3rd position

These PIPs are involved in various cellular processes such as membrane trafficking, cytoskeleton organization, cell survival, and metabolism. Dysregulation of PIP metabolism has been implicated in several diseases, including cancer, diabetes, and neurological disorders.

Video microscopy is a medical technique that involves the use of a microscope equipped with a video camera to capture and display real-time images of specimens on a monitor. This allows for the observation and documentation of dynamic processes, such as cell movement or chemical reactions, at a level of detail that would be difficult or impossible to achieve with the naked eye. Video microscopy can also be used in conjunction with image analysis software to measure various parameters, such as size, shape, and motion, of individual cells or structures within the specimen.

There are several types of video microscopy, including brightfield, darkfield, phase contrast, fluorescence, and differential interference contrast (DIC) microscopy. Each type uses different optical techniques to enhance contrast and reveal specific features of the specimen. For example, fluorescence microscopy uses fluorescent dyes or proteins to label specific structures within the specimen, allowing them to be visualized against a dark background.

Video microscopy is used in various fields of medicine, including pathology, microbiology, and neuroscience. It can help researchers and clinicians diagnose diseases, study disease mechanisms, develop new therapies, and understand fundamental biological processes at the cellular and molecular level.

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

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

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

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

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

Platelet-Derived Growth Factor (PDGF) is a dimeric protein with potent mitogenic and chemotactic properties that plays an essential role in wound healing, blood vessel growth, and cellular proliferation and differentiation. It is released from platelets during the process of blood clotting and binds to specific receptors on the surface of target cells, including fibroblasts, smooth muscle cells, and glial cells. PDGF exists in several isoforms, which are generated by alternative splicing of a single gene, and have been implicated in various physiological and pathological processes, such as tissue repair, atherosclerosis, and tumor growth.

Leukotriene B4 (LTB4) receptors are a type of G protein-coupled receptor that bind to and are activated by the lipid mediator Leukotriene B4. There are two main types of LTB4 receptors, named BLT1 and BLT2.

BLT1 is highly expressed in cells of the immune system such as neutrophils, eosinophils, monocytes, and dendritic cells, and it mediates many of the pro-inflammatory effects of LTB4, including chemotaxis, adhesion, and activation of these cells.

BLT2 is more widely expressed in various tissues, including the skin, lung, and intestine, and it has been shown to play a role in a variety of physiological and pathological processes, such as pain sensation, wound healing, and cancer progression.

Overall, LTB4 receptors are important targets for the development of therapies aimed at modulating inflammation and immune responses.

G-protein-coupled receptors (GPCRs) are a family of membrane receptors that play an essential role in cellular signaling and communication. These receptors possess seven transmembrane domains, forming a structure that spans the lipid bilayer of the cell membrane. They are called "G-protein-coupled" because they interact with heterotrimeric G proteins upon activation, which in turn modulate various downstream signaling pathways.

When an extracellular ligand binds to a GPCR, it causes a conformational change in the receptor's structure, leading to the exchange of guanosine diphosphate (GDP) for guanosine triphosphate (GTP) on the associated G protein's α subunit. This exchange triggers the dissociation of the G protein into its α and βγ subunits, which then interact with various effector proteins to elicit cellular responses.

There are four main families of GPCRs, classified based on their sequence similarities and downstream signaling pathways:

1. Gq-coupled receptors: These receptors activate phospholipase C (PLC), which leads to the production of inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 induces calcium release from intracellular stores, while DAG activates protein kinase C (PKC).
2. Gs-coupled receptors: These receptors activate adenylyl cyclase, which increases the production of cyclic adenosine monophosphate (cAMP) and subsequently activates protein kinase A (PKA).
3. Gi/o-coupled receptors: These receptors inhibit adenylyl cyclase, reducing cAMP levels and modulating PKA activity. Additionally, they can activate ion channels or regulate other signaling pathways through the βγ subunits.
4. G12/13-coupled receptors: These receptors primarily activate RhoGEFs, which in turn activate RhoA and modulate cytoskeletal organization and cellular motility.

GPCRs are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and sensory perception. Dysregulation of GPCR function has been implicated in numerous diseases, making them attractive targets for drug development.

Chemokine (C-X-C motif) ligand 1 (CXCL1), also known as growth-regulated oncogene-alpha (GRO-α), is a small signaling protein belonging to the chemokine family. Chemokines are a group of cytokines, or cell signaling molecules, that play important roles in immune responses and inflammation by recruiting immune cells to sites of infection or tissue injury.

CXCL1 specifically binds to and activates the CXCR2 receptor, which is found on various types of immune cells, such as neutrophils, monocytes, and lymphocytes. The activation of the CXCR2 receptor by CXCL1 leads to a series of intracellular signaling events that result in the directed migration of these immune cells towards the site of chemokine production.

CXCL1 is involved in various physiological and pathological processes, including wound healing, angiogenesis, and tumor growth and metastasis. It has been implicated in several inflammatory diseases, such as rheumatoid arthritis, psoriasis, and atherosclerosis, as well as in cancer progression and metastasis.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

'Escherichia coli (E. coli) proteins' refer to the various types of proteins that are produced and expressed by the bacterium Escherichia coli. These proteins play a critical role in the growth, development, and survival of the organism. They are involved in various cellular processes such as metabolism, DNA replication, transcription, translation, repair, and regulation.

E. coli is a gram-negative, facultative anaerobe that is commonly found in the intestines of warm-blooded organisms. It is widely used as a model organism in scientific research due to its well-studied genetics, rapid growth, and ability to be easily manipulated in the laboratory. As a result, many E. coli proteins have been identified, characterized, and studied in great detail.

Some examples of E. coli proteins include enzymes involved in carbohydrate metabolism such as lactase, sucrase, and maltose; proteins involved in DNA replication such as the polymerases, single-stranded binding proteins, and helicases; proteins involved in transcription such as RNA polymerase and sigma factors; proteins involved in translation such as ribosomal proteins, tRNAs, and aminoacyl-tRNA synthetases; and regulatory proteins such as global regulators, two-component systems, and transcription factors.

Understanding the structure, function, and regulation of E. coli proteins is essential for understanding the basic biology of this important organism, as well as for developing new strategies for combating bacterial infections and improving industrial processes involving bacteria.

Chemokine (C-C motif) ligand 4, also known as CCL4 or MIP-1β (Macrophage Inflammatory Protein-1β), is a small signaling protein that belongs to the chemokine family. Chemokines are a group of cytokines, or regulatory proteins, that play crucial roles in immunity and inflammation by directing the migration of various immune cells to sites of infection, injury, or tissue damage.

CCL4 is produced primarily by T cells, monocytes, macrophages, and dendritic cells. It exerts its functions by binding to specific chemokine receptors found on the surface of target cells, particularly CCR5 and CXCR3. The primary role of CCL4 is to recruit immune cells like T cells, eosinophils, and monocytes/macrophages to areas of inflammation or infection, where it contributes to the elimination of pathogens and facilitates tissue repair.

Aberrant regulation of chemokines, including CCL4, has been implicated in various disease conditions such as chronic inflammation, autoimmune disorders, and viral infections like HIV. In HIV infection, CCL4 plays a significant role in the viral replication and pathogenesis by acting as a co-receptor for virus entry into host cells.

The term "Receptor, Anaphylatoxin C5a" refers to a specific type of receptor found on the surface of various cells in the human body, including immune cells and endothelial cells. This receptor binds to a molecule called C5a, which is a cleavage product of the complement component C5 and is one of the most potent anaphylatoxins.

Anaphylatoxins are inflammatory mediators that play a crucial role in the immune response, particularly in the activation of the complement system and the recruitment of immune cells to sites of infection or injury. C5a is generated during the activation of the complement system and has a wide range of biological activities, including chemotaxis (attracting immune cells to the site of inflammation), increased vascular permeability, and the activation of immune cells such as neutrophils, monocytes, and mast cells.

The C5a receptor, also known as CD88, is a G protein-coupled receptor that belongs to the superfamily of seven transmembrane domain receptors. When C5a binds to the receptor, it triggers a series of intracellular signaling events that lead to the activation of various cellular responses, such as the release of inflammatory mediators and the recruitment of immune cells to the site of inflammation.

Abnormal activation of the C5a/C5a receptor pathway has been implicated in a variety of inflammatory diseases, including sepsis, acute respiratory distress syndrome (ARDS), and autoimmune disorders. Therefore, targeting this pathway with therapeutic agents has emerged as a promising strategy for the treatment of these conditions.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

Chemokine (C-X-C motif) ligand 1 (CX3CL1), also known as fractalkine, is a protein that belongs to the chemokine family. Chemokines are a group of small signaling proteins involved in immune responses and inflammation. CX3CL1 is unique among chemokines because it exists both as a soluble protein and as a membrane-bound protein on the surface of certain cells.

As a chemoattractant, CX3CL1 plays a crucial role in recruiting immune cells, particularly T cells and monocytes/macrophages, to sites of infection or injury. The interaction between CX3CL1 and its receptor, CX3CR1, expressed on the surface of these immune cells, mediates their migration and activation.

In addition to its role in immunity and inflammation, CX3CL1 has been implicated in various physiological and pathological processes, such as neuronal development, neuroinflammation, and neurodegenerative disorders like Alzheimer's disease and Parkinson's disease.

The cytoskeleton is a complex network of various protein filaments that provides structural support, shape, and stability to the cell. It plays a crucial role in maintaining cellular integrity, intracellular organization, and enabling cell movement. The cytoskeleton is composed of three major types of protein fibers: microfilaments (actin filaments), intermediate filaments, and microtubules. These filaments work together to provide mechanical support, participate in cell division, intracellular transport, and help maintain the cell's architecture. The dynamic nature of the cytoskeleton allows cells to adapt to changing environmental conditions and respond to various stimuli.

A ligand, in the context of biochemistry and medicine, is a molecule that binds to a specific site on a protein or a larger biomolecule, such as an enzyme or a receptor. This binding interaction can modify the function or activity of the target protein, either activating it or inhibiting it. Ligands can be small molecules, like hormones or neurotransmitters, or larger structures, like antibodies. The study of ligand-protein interactions is crucial for understanding cellular processes and developing drugs, as many therapeutic compounds function by binding to specific targets within the body.

Microfluidics is a multidisciplinary field that involves the study, manipulation, and control of fluids that are geometrically constrained to a small, typically sub-millimeter scale. It combines elements from physics, chemistry, biology, materials science, and engineering to design and fabricate microscale devices that can handle and analyze small volumes of fluids, often in the range of picoliters to microliters.

In medical contexts, microfluidics has numerous applications, including diagnostic testing, drug discovery, and personalized medicine. For example, microfluidic devices can be used to perform rapid and sensitive molecular assays for detecting pathogens or biomarkers in patient samples, as well as to screen drugs and evaluate their efficacy and toxicity in vitro.

Microfluidics also enables the development of organ-on-a-chip platforms that mimic the structure and function of human tissues and organs, allowing researchers to study disease mechanisms and test new therapies in a more physiologically relevant context than traditional cell culture models. Overall, microfluidics offers significant potential for improving healthcare outcomes by enabling faster, more accurate, and more cost-effective diagnostic and therapeutic strategies.

Class Ib Phosphatidylinositol 3-Kinases (PI3Ks) are a subclass of PI3K enzymes that play a crucial role in cellular signaling pathways. These enzymes phosphorylate the 3-hydroxyl group of the inositol ring in phosphatidylinositol, creating phosphatidylinositol 3-phosphate (PIP). This lipid second messenger is involved in various cellular processes such as cell growth, proliferation, differentiation, and survival.

The Class Ib PI3Ks are heterodimers composed of a catalytic subunit (p110γ) and a regulatory subunit (p84 or p101). The p110γ catalytic subunit is activated by G protein-coupled receptors (GPCRs) and Ras family small GTPases. Once activated, the p110γ subunit phosphorylates phosphatidylinositol 4,5-bisphosphate (PIP2) to produce PIP3, which in turn recruits downstream signaling proteins containing pleckstrin homology (PH) domains to the plasma membrane.

Abnormal activation of Class Ib PI3Ks has been implicated in various diseases, including cancer and inflammatory disorders. Therefore, targeting these enzymes has emerged as a potential therapeutic strategy for treating these conditions.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Lysophospholipids are a type of glycerophospholipid, which is a major component of cell membranes. They are characterized by having only one fatty acid chain attached to the glycerol backbone, as opposed to two in regular phospholipids. This results in a more polar and charged molecule, which can play important roles in cell signaling and regulation.

Lysophospholipids can be derived from the breakdown of regular phospholipids through the action of enzymes such as phospholipase A1 or A2. They can also be synthesized de novo in the cell. Some lysophospholipids, such as lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P), have been found to act as signaling molecules that bind to specific G protein-coupled receptors and regulate various cellular processes, including proliferation, survival, and migration.

Abnormal levels of lysophospholipids have been implicated in several diseases, such as cancer, inflammation, and neurological disorders. Therefore, understanding the biology of lysophospholipids has important implications for developing new therapeutic strategies.

Methyltransferases are a class of enzymes that catalyze the transfer of a methyl group (-CH3) from a donor molecule to an acceptor molecule, which is often a protein, DNA, or RNA. This transfer of a methyl group can modify the chemical and physical properties of the acceptor molecule, playing a crucial role in various cellular processes such as gene expression, signal transduction, and DNA repair.

In biochemistry, methyltransferases are classified based on the type of donor molecule they use for the transfer of the methyl group. The most common methyl donor is S-adenosylmethionine (SAM), a universal methyl group donor found in many organisms. Methyltransferases that utilize SAM as a cofactor are called SAM-dependent methyltransferases.

Abnormal regulation or function of methyltransferases has been implicated in several diseases, including cancer and neurological disorders. Therefore, understanding the structure, function, and regulation of these enzymes is essential for developing targeted therapies to treat these conditions.

Chemokine CCL11, also known as eotaxin-1, is a small chemotactic cytokine that belongs to the CC subfamily of chemokines. Chemokines are a group of proteins that play crucial roles in immunity and inflammation by recruiting immune cells to sites of infection or tissue injury.

CCL11 specifically attracts eosinophils, a type of white blood cell that is involved in allergic reactions and the immune response to parasitic worm infections. It does this by binding to its specific receptor, CCR3, which is expressed on the surface of eosinophils and other cells.

CCL11 is produced by a variety of cells, including epithelial cells, endothelial cells, fibroblasts, and immune cells such as macrophages and Th2 lymphocytes. It has been implicated in the pathogenesis of several diseases, including asthma, allergies, and certain neurological disorders.

Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.

For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.

Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.

Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.

... Neutrophil Chemotaxis Cell Migration Gateway Downloadable Matlab chemotaxis simulator Bacterial Chemotaxis ... Chemotaxis (from chemo- + taxis) is the movement of an organism or entity in response to a chemical stimulus. Somatic cells, ... Positive chemotaxis occurs if the movement is toward a higher concentration of the chemical in question; negative chemotaxis if ... "Bacterial Chemotaxis" (PDF). Archived (PDF) from the original on 6 May 2017. Berg HC, Brown DA (October 1972). "Chemotaxis in ...
Eisenbach, M. (2004) Chemotaxis. Imperial College Press, London. Miller, R.L. (1997) Specificity of sperm chemotaxis among ... In some species (for example, herring or the ascidian Ciona) activation of motility precedes chemotaxis. In chemotaxis, cells ... chemotaxis was substantiated as the cause of this accumulation. Sperm chemotaxis was later also demonstrated in mice and ... sperm guidance in the form of sperm chemotaxis has been established in a large variety of species Although sperm chemotaxis is ...
Chemotaxis Cell Migration Gateway Cytometric chemotaxis and cell migration assay Free tool based on ImageJ to analyse ... Zicha D.; Dunn G.A.; Brown A.F. (1991). "A new direct-viewing chemotaxis chamber". J Cell Sci. 99 (4): 769-75. doi:10.1242/jcs. ... Chemotaxis assays are experimental tools for evaluation of chemotactic ability of prokaryotic or eukaryotic cells. A wide ... Seymour J. R.; J. R. Ahmed; Marcos S. R (2008). "A microfluidic chemotaxis assay to study microbial behavior in diffusing ...
These methyl-accepting chemotaxis receptors are one of the first components in the sensory excitation and adaptation responses ... The methyl-accepting chemotaxis proteins (MCP, also aspartate receptor) are a family of transmembrane receptors that mediate ... Wikimedia Commons has media related to Methyl-accepting chemotaxis protein. This article incorporates text from the public ...
Chemotaxis. River Edge, N.J: Imperial College Press. ISBN 1-86094-413-2. Stackebrandt E, Dworkin M, Falkow S, Rosenberg E, ...
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In contrast to the run-and-tumble model of chemotaxis associated with flagellated cells however, movement towards ... Oliveira, Nuno M.; Foster, Kevin R.; Durham, William M. (2016-06-07). "Single-cell twitching chemotaxis in developing biofilms ... Sampedro, Inmaculada; Parales, Rebecca E.; Krell, Tino; Hill, Jane E. (January 2015). "Pseudomonas chemotaxis". FEMS ... "Pseudomonas aeruginosa Twitching Motility-Mediated Chemotaxis towards Phospholipids and Fatty Acids: Specificity and Metabolic ...
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In general terms, chemotaxis is a biological process where living entities, such as cells or organisms, detect, maneuver, and ... Chemotaxis also plays an essential role in serval diseases, such as tumor metastasis, the recruitment of T-lymphocytes during ... By using both chemotaxes to help guide the drug delivery process, researchers aim to reduce toxicity by avoiding healthy ... Chemotaxis Archived 30 July 2014 at the Wayback Machine (CS1 errors: periodical ignored, Use dmy dates from April 2022, ...
Chemotaxis is another scheme that allows an organism to move toward or away from gradients of nutrients or other chemical ... This can result in a chemotaxis, where attractant gradients extend the length of time flagellar motors rotate CCW, resulting in ... Webre, D.J.; Wolanin, P.M; Stock, J.B. (2003). "Bacterial chemotaxis" (PDF). Current Biology. 13 (2): R47-R49. doi:10.1016/ ... Wadhams, George H.; Armitage, Judith P. (2004). "Making sense of it all: bacterial chemotaxis". Nature Reviews Molecular Cell ...
Hillen, T.; Painter, K. J. (Jan 2009). "A user's guide to PDE models for chemotaxis. Journal of Mathematical Biology". J Math ... He is particularly known for his work in the spontaneous appearance of order in convection, slime molds and chemotaxis. Lee ... They also developed a model for chemotaxis. Hillen and Painter say of it: "its success ... a consequence of its intuitive ... Keller, E. F.; Segel, L. A. (1971). "Model for chemotaxis". J Theor Biol. 30 (2): 225-234. Bibcode:1971JThBi..30..225K. doi: ...
By 2005, her research team had identified a novel pathway that turned out to be critical for cell migration and chemotaxis, ... Lokuta, M. A., Nuzzi, P. A., & Huttenlocher, A. (2003). Calpain regulates neutrophil chemotaxis. Proceedings of the National ... Resolution of inflammation by retrograde chemotaxis of neutrophils in transgenic zebrafish. Journal of Leukocyte Biology, 80(6 ... that regulate cell migration and identified basic adhesive mechanisms that regulate cell migration and leukocyte chemotaxis. ...
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During the acute phase of inflammation, neutrophils migrate toward the site of inflammation in a process called chemotaxis, and ... chemokines that promote chemotaxis; and interferons that have anti-viral effects, such as shutting down protein synthesis in ... chemokines that promote chemotaxis; and interferons that have anti-viral effects, such as shutting down protein synthesis in ...
Realizing that chemotaxis is a short-range process, operating over only a few millimetres, Eisenbach looked for a long-range ... Chemotaxis (515 pages) by Eisenbach, M. (2004), published by Imperial College Press, London. Sensing and Response in ... Bacteria are attracted to some chemicals and repelled from others by chemotaxis. They do it by modulating the direction of ... Eisenbach, M. (2004) "Chemotaxis" Imperial College Press, London Eisenbach, M. (2007) "A hitchhiker's guide through advances ...
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Chemotaxis towards an injured cell". Antibiot. Chemother. 19: 369-81. doi:10.1159/000395442. PMID 4463832. Hu CL, Barnes FS ( ... Necrotaxis embodies a special type of chemotaxis when the chemoattractant molecules are released from necrotic or apoptotic ... "A particular form of chemotaxis: necrotaxis. An historical view". Blood Cells. 19 (1): 5-19. PMID 8400312. Ragot R. (1993). " ...
Baker, Melinda D.; Wolanin, Peter M.; Stock, Jeffry B. (2006). "Signal transduction in bacterial chemotaxis". BioEssays. 28 (1 ... Zhuang, Jiang; Park, Byung-Wook; Sitti, Metin (2017). "Propulsion and Chemotaxis in Bacteria-Driven Microswimmers". Advanced ... "Magnetic Field Guided Chemotaxis of i Mushbots for Targeted Anticancer Therapeutics". ACS Biomaterials Science & Engineering. 3 ... "Motility and chemotaxis of bacteria-driven microswimmers fabricated using antigen 43-mediated biotin display". Scientific ...
I. {{cite journal}}: Cite uses generic title (help) Harris H (Jul 1954). "Role of chemotaxis in inflammation". Physiological ... fMLF proved the most potent in stimulating rabbit neutrophil chemotaxis. fMLF and a sampling of other, less potent, N-formyl ... Leukocyte chemotaxis: Methodology, physiology, clinical implications. New York.: Raven Press. O'Flaherty JT, Showell HJ, ... release N-formyl-methionyl containing peptides with chemotactic activities that exactly mimic those of fMLF chemotaxis These ...
Other names in common use include chemotaxis-specific methylesterase, methyl-accepting chemotaxis protein methyl-esterase, CheB ... CheB is involved in chemotaxis. CheB methylesterase is responsible for removing the methyl group from the gamma-glutamyl methyl ... Kehry MR, Doak TG, Dahlquist FW (1984). "Stimulus-induced changes in methylesterase activity during chemotaxis in Escherichia ... This enzyme participates in 3 metabolic pathways: two-component system - general, bacterial chemotaxis - general, and bacterial ...
Self-propelled enzyme motors and synthetic nanomotors also exhibit clustering effects in the form of chemotaxis. Chemotaxis is ... Schnitzer, Mark J. (1 October 1993). "Theory of continuum random walks and application to chemotaxis". Physical Review E. 48 (4 ... Hong, Yiying; Blackman, Nicole M. K.; Kopp, Nathaniel D.; Sen, Ayusman; Velegol, Darrell (26 October 2007). "Chemotaxis of ... as observed experimentally in enzyme diffusion and also synthetic chemotaxis or phototaxis. In addition to irreversible ...
... in a process called chemotaxis. A number of variables are essential for the successful chemotaxis of neutrophils, including the ... It induces chemotaxis in target cells, primarily neutrophils but also other granulocytes, causing them to migrate toward the ... This causes the "rolling" phase of chemotaxis. Once the neutrophil is rolling along the endothelium, it will come into contact ... Köhidai L, Csaba G (1998). "Chemotaxis and chemotactic selection induced with cytokines (IL-8, RANTES and TNF-alpha) in the ...
Lux R, Shi W (July 2004). "Chemotaxis-guided movements in bacteria". Critical Reviews in Oral Biology and Medicine. 15 (4): 207 ... Motile bacteria are attracted or repelled by certain stimuli in behaviours called taxes: these include chemotaxis, phototaxis, ...
H. pylori is able to sense the pH gradient in the mucus and move towards the less acidic region (chemotaxis). This also keeps ... In addition to using chemotaxis to avoid areas of low pH, H. pylori also neutralizes the acid in its environment by producing ... Rust M, Schweinitzer T, Josenhans C (2008). "Helicobacter Flagella, Motility and Chemotaxis". In Yamaoka, Y. (ed.). ...
Chemotaxis Chemoreceptor Mechanism Turrà, David; El Ghalid, Mennat; Rossi, Federico; Di Pietro, Antonio (2015). "Fungal ... Chemotropism is slightly different from Chemotaxis, the major difference being that chemotropism is related to growth, while ... chemotaxis is related to locomotion. A chemotropic process may have an underlying chemotactic component, as is the case with ...
To move towards a target, the cell uses chemotaxis. It senses extracellular signalling molecules, chemoattractants (e.g. cAMP ... Van Haastert PJM & Devreotes PN (2004). "Chemotaxis: signalling the way forward". Nature Reviews Molecular Cell Biology. 5 (8 ...
... a phenomenon defined as chemotaxis. Chemotaxis has been observed in self-propelled Au-Pt nanorods, which diffuse towards the ... which is known as enzyme chemotaxis. One interesting use of enzyme nanomotor chemotaxis is the separation of active and ... In general, chemotaxis of biological and synthesized self-propelled particles provides a way of directing motion at the ... Hong, Y.; Blackmann, NMK; Kopp, ND.; Sen, A.; Velegol, D. (2007). "Chemotaxis of nonbiological colloidal rods". Physical Review ...
Stromal cells release signaling proteins to induce chemotaxis, which leads to organ-specific metastasis. Epidermal growth ... Chemotaxis, a biased migration of cells under a chemical gradient, plays a significant role in diverse biological phenomena ... Chemotaxis Model for Breast Cancer Cells Based on Signal/Noise Ratio Seongjin Lim 1 , Hyeono Nam 1 , Jessie S Jeon 2 ... can promote chemotaxis at an EGF gradient of 0-1 ng/mL as shown by chemotaxis index (0.121 ± 0.037, reduced EGFRs vs. 0.003 ± ...
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Mechanisms of Chemotaxis to EGF and How They Determine Metastatic Potential in Breast Cancer (NIH-Only) ... Mechanisms of Chemotaxis to EGF and How They Determine Metastatic Potential in Breast Cancer (NIH-Only) ...
Everything posted by Chemotaxis. * Episode 219.5 Chemotaxis replied to Cameron H.s topic in How Did This Get Made? ...
Regulation of the chemotaxis histidine kinase CheA: A structural perspective. Muok AR, Briegel A, Crane BR. Muok AR, et al. ... Structure and dynamics of the E. coli chemotaxis core signaling complex by cryo-electron tomography and molecular simulations C ... Using Atomistic Simulations to Explore the Role of Methylation and ATP in Chemotaxis Signal Transduction. Joshi H, Prakash MK. ... Making sense of it all: bacterial chemotaxis. Nat. Rev. Mol. Cell Biol. 2004;5:1024-1037. doi: 10.1038/nrm1524. - DOI - PubMed ...
chemotaxis. Cool Videos: Making Multicolored Waves in Cell Biology Posted on March 16th, 2017. by Dr. Francis Collins ... Tags: art, bacteria, cell biology, cell division, cell migration, cell-free biology, cell-free systems, cells, chemotaxis, E. ...
Chemotaxis is frequently inferred based on how many cells cross a boundary in a chemotaxis assay, for example how many cells ... Chemotaxis of MDA-MB-231 cells, and cells with similar gradient sensitivity, cannot be measured by counting the cells in the ... The number of cells crossing a boundary is a weak indicator of chemotaxis. Thursday, September 17, 2015. - Poster Session III ... Chemotaxis, the motion of cells directed by a gradient of chemoattractant molecules, is difficult to measure. ...
As a theoretician in the lab of Dr. Ralph Nossal (NICHD), I use mathematical modeling to study how cells get to places in the body. Most of my time is focused on completing clearly written goals born from project plans. A system of timers, project plans, and goals keeps me on track to do what I need to do so that I can get back to the fun part of my job that I would happily do for free. ...
Differential regulation of chemotaxis: Role of Gβγ in chemokine receptor-induced cell migration ... ORCID: https://orcid.org/0000-0003-0774-0434 (2013) Differential regulation of chemotaxis: Role of Gβγ in chemokine receptor- ...
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Chemotaxis of Dendritic Cells Movement of DCs is precisely controlled by chemokines milieu and concentration. Expression of ... is a key player in regulating the chemotaxis of DCs in the lungs.[92] Migration of DC via KCa3.1 is modulated at two levels ...
bacterial chemotaxis, core-signaling unit, adaptor protein, histidine kinase, chemoreceptor, SIGNALING PROTEIN ... HAMP domain, poly-HAMP domains, bacterial chemotaxis, Two-component signal transduction, dimeric parallel coiled coil, Coiled ...
Our research strategy to define the signaling network controlling chemotaxis relies on the use of the genetically amendable ... The research in the Chemotaxis Signal Section is focused on understanding the cellular and molecular mechanisms underlying ... is the Chief of the Chemotaxis Signal Section. ... Chemotaxis Signal Section. Tian Jin, Ph.D. Chief, Chemotaxis ... Mechanisms underlying the GPCR-mediated chemotaxis in Dictyostelium discoideum. *Mechanisms involved in chemotaxis of immune ...
Chemotaxis. Chemotaxis. (kee-moh-TAK-sis) The movement of a cell toward or away from a chemical force. ...
On-Chip Open Microfluidic Devices for Chemotaxis Studies - Volume 18 Issue 4 ... Jeon, N.L., Baskaran, H., Dertinger, S.K.W., Whitesides, G.M., Van De Water, L. & Toner, M. (2002). Neutrophil chemotaxis in ... Raja, W.K., Gligorijevic, B., Wyckoff, J., Condeelis, J.S. & Castracane, J. (2010). A new chemotaxis device for cell migration ... Zicha, D., Dunn, G. & Jones, G. (1997). Analyzing chemotaxis using the Dunn direct-viewing chamber. Methods Mol Biol 75, 449- ...
Chemotaxis. Neurobiology. Genre(s):. Archival Materials. Laboratory notes. Abstract:. In these notes, Nirenberg outlines ... Notes on nematodes and chemotaxis. Contributor(s):. Nirenberg, Marshall W.. Publication:. Produced: [10-22 June 1967] Language( ... These notes are focused on the study of nematodes and on the chemotaxis of bacteria. Copyright:. This item may be under ...
Geobacter metallireducens accesses insoluble Fe(III) oxide by chemotaxis.. Title. Geobacter metallireducens accesses insoluble ... Bacterial Proteins, Chemotaxis, Deltaproteobacteria, DNA-Binding Proteins, Ferric Compounds, Ferrous Compounds, Fimbriae ...
ibidi is a leading supplier for functional cell-based assays and advanced products for cellular microscopy. ibidi is located in Gräfelfing, Germany, close to Munich, and the US headquarters, ibidi USA Inc., is located in Fitchburg, Wisconsin ...
Pattern Formation of a Chemotaxis-diffusion-growth model * Tohru Tsujikawa (Miyazaki University) ...
involved_in eosinophil chemotaxis IBA Inferred from Biological aspect of Ancestor. more info ... involved_in lymphocyte chemotaxis IBA Inferred from Biological aspect of Ancestor. more info ... involved_in monocyte chemotaxis IBA Inferred from Biological aspect of Ancestor. more info ... involved_in neutrophil chemotaxis IBA Inferred from Biological aspect of Ancestor. more info ...
Chemotaxis * Gene Expression Regulation, Neoplastic * Gene Regulatory Networks * Genes, Reporter * Genes, myc ...
Chemotaxis assay. * *Transwell cell migration assay was performed using a cell migration assay kit to determine the effect of ... revealing LTB4 as a major mediator of neutrophil chemotaxis from MWCNT-polarized macrophages. Knockdown of Alox5 using specific ...
8 samples for days 0, 12, and 25; for chemotaxis assay: experiments for each genotype).. ... "Rac1 is the small GTPase responsible for regulating the neutrophil chemotaxis compass," Blood, vol. 104, no. 12, pp. 3758-3765 ...
Eosinophil chemotaxis and success within tissues are fundamental components in the. Eosinophil chemotaxis and success within ... Eosinophil chemotaxis and success within tissue are improved through contact with particular cytokines, chemokines, and various ... improving chemotaxis into tissue, and delaying eosinophil apoptosis within tissue.8 Of note, IL-3, IL-5, and GM-CSF are ... 7 Delineation of mechanisms mediating chemotaxis, activation, and survival of eosinophils is thus a stylish objective for ...
Chemotaxis release of chemicals by damaged cells that attract whit blood cells. ...
Microfluidics and nanotechnologies; myeloid cells immune biology; chemotaxis. [email protected] ...
IL-5: IL-5 is key in the maturation, chemotaxis, activation, and survival of eosinophils. IL-5 primes basophils for histamine ... Some of the mediators released by mast cells and basophils cause eosinophil and neutrophil chemotaxis. Attracted eosinophils ... It increases vascular permeability, causes bronchoconstriction, and causes chemotaxis and degranulation of eosinophils and ... increases monocyte chemotaxis; promotes histamine and tryptase secretion from mast cells; upregulation of MHC class II and IL2R ...
  • Results PMN functions were severely impaired shortly after HF (chemotaxis, phagocytosis, superoxide production) but there was a time-related recovery of some PMN functions (chemotaxis, phagocytosis) over time, except in the case of superoxide production. (stir.ac.uk)
  • In this two-part explorative proteomic study, we demonstrate how proteins associated with tissue remodeling, inflammation and chemotaxis such as MMP7, CXCL13 and CCL19 are released in response to aberrant extracellular matrix (ECM) in IPF lung. (lu.se)
  • This review summarizes some immunological factors involved in the development and control of this oral disease, such as: the participation of inflammatory cells in local inflammation, the synthesis of chemotaxis proteins with activation of the complement system and a range of antimicrobial peptides, such as defensins, cathelicidin and saposins. (bvsalud.org)
  • In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis. (wikipedia.org)
  • Anonymous Reviewer ( 2020 ) Peer Review #2 of 'ELMO2 association with Gαi2 regulates pancreatic cancer cell chemotaxis and metastasis (v0.2)' . (peerj.com)
  • The pathogenesis of the disease is unclear, but altered expression of cytokines and cellular adhesion molecules, important for chemotaxis of LC, are thought to be involved in its development. (medscape.com)
  • In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and development (e.g., migration of neurons or lymphocytes) as well as in normal function and health (e.g., migration of leukocytes during injury or infection). (wikipedia.org)
  • 2012). 100 years of sperm chemotaxis. (edu.au)
  • Sperm cells have been found to exhibit chemotaxis, which allows them to sense and move towards the egg. (reproduction-online.org)
  • From enhanced motility and the acrosome reaction to DNA packaging and chemotaxis, sperm cells are finely tuned for their role in reproduction. (reproduction-online.org)
  • Motility and chemotaxis. (lu.se)
  • Spagnuolo, PJ & Ellner, JJ 1977, ' Aspirin (ASA) inhibits in vitro human granulocyte adherence (GA) and chemotaxis (CX) and in vivo granulocyte response to experimental pneumococcal peritonitis ', Clinical Research , vol. 25, no. 4. (johnshopkins.edu)
  • Next, we examined no matter whether oxidized lipids andToxins 2014,LPC induce the in vitro monocyte chemotaxis. (potassiun-channel.com)
  • Numerous isoforms of HODE, and LPC induce the in vitro chemotaxis of human monocytes. (potassiun-channel.com)
  • For example, bacteria commonly show positive chemotaxis, swimming towards regions containing higher concentrations of food substances 66 chiasma interference such as peptone and lactose. (botanydictionary.org)
  • The aberrant chemotaxis of leukocytes and lymphocytes also contribute to inflammatory diseases such as atherosclerosis, asthma, and arthritis. (wikipedia.org)
  • Alternatively, cells recognize toxic stimuli, known as chemorepellents, and exhibit negative chemotaxis by moving away from the concentration gradient [1]. (openwetware.org)
  • Chemotaxis is the attractive movement of an organism in response to a chemical stimulus, usually toward or "up" the chemical concentration gradient. (edu.au)
  • negative chemotaxis if the movement is in the opposite direction. (wikipedia.org)
  • Both positive and negative chemotaxis are important to understanding and engineering cell motion in relation to tissue engineering in human systems. (openwetware.org)
  • Negative chemotaxis may be shown in response to toxic substances. (botanydictionary.org)
  • Chemotaxis (from chemo- + taxis) is the movement of an organism or entity in response to a chemical stimulus. (wikipedia.org)
  • Figure 2 illustrates three events that are affected by chemotaxis within the tumor microenvironment: immune evasion, angiogenesis, and invasion and dissemination. (openwetware.org)
  • Chemokine receptors CXCR2, CXCR3, CXCR4, and CXCR7 induce endothelial cell chemotaxis toward the tumor. (openwetware.org)
  • Chemokine-enhanced chemotaxis of lymphangioleiomyomatosis cells with mutations in the tumor suppressor TSC2 gene. (cdc.gov)
  • Chemotaxis is vital to improving tissue engineered constructs for optimal wound recovery [7]. (openwetware.org)
  • Chemotaxis is the directional migration of cells in response to chemical stimuli or external cues [1]. (openwetware.org)
  • E lipids have been in a position to stimulate chemotaxis in these cells [22]. (potassiun-channel.com)
  • Numerous Isoforms of HODEs and LPC Induce Chemotaxis of Major Human Monocytes To demonstrate that major human monocytes are impacted by the lipids, we initial confirmed that these cells contained about 90 CD14+, much less than five CD3+ T cells and significantly less than 1 CD19+ B cells as determined by flow cytometric analysis (Figure S1). (potassiun-channel.com)
  • LPC Induces the Mobilization of Intracellular Calcium in Major Human Monocytes Next, we examined irrespective of whether the lipids that augment chemotaxis of monocytes may well also induce the mobilization of intracellular Ca2+ in these cells. (potassiun-channel.com)
  • Chemotaxis: Dendritic cells as trendsetters of the immune response. (bvsalud.org)
  • Chemotaxis is the ability of cells to move towards or away from certain chemicals. (reproduction-online.org)
  • These final results indicate that numerous HODEs at the same time as LPC induce the chemotaxis in monocytes though at distinct concentrations, suggesting that the lipids could have distinctive affinities for the receptor, or they might make use of various receptors. (potassiun-channel.com)
  • However, SWCNT suppressed chemotaxis of primary human monocytes in a standard chemotaxis assay. (cdc.gov)
  • In this regard, the external stimuli is known as a chemoattractant and induces positive chemotaxis in which the cell moves from low to high concentration of the chemoattractant. (openwetware.org)
  • The most important aspects in quality control of chemotaxis assays were described by H. Harris in the 1950s. (wikipedia.org)
  • Our outcomes show that 1 and ten ?of 9-S-HODE M induced chemotaxis (p 0.01 and 0.0001, respectively as in comparison to the handle, Figure 1A). (potassiun-channel.com)
  • The significance of chemotaxis in biology and clinical pathology was widely accepted in the 1930s, and the most fundamental definitions underlying the phenomenon were drafted by this time. (wikipedia.org)
  • Additionally, 0.01?0 of 9-R-HODE and 13-R-HODE induced their chemotaxis (Figure 1B,C, respectively). (potassiun-channel.com)
  • Alternatively, only the highest concentration, i.e., ten ?of LPC induced monocyte M chemotaxis (p 0.005, Figure 1D). (potassiun-channel.com)
  • Persistent inflammation and impaired chemotaxis of alveolar macrophages on cessation of dust exposure. (nih.gov)
  • The cell-free media from MWCNT-polarized macrophages induced the migration of neutrophilic cells (differentiated from HL-60), which was blocked by Acebilustat, a specific leukotriene A4 hydrolase inhibitor, or LY239111, an LTB4 receptor antagonist, but not NS-398, a cyclooxygenase 2 inhibitor, revealing LTB4 as a major mediator of neutrophil chemotaxis from MWCNT-polarized macrophages. (cdc.gov)
  • Chemotaxis is frequently inferred based on how many cells cross a boundary in a chemotaxis assay, for example how many cells crawl into the filter in the filter migration assay or how many cells crawl into a defined region in the under agarose assay or agarose spot assay. (nih.gov)
  • moreover, measurement of chemotaxis of these cells using the filter assay requires robust controls. (nih.gov)
  • However, SWCNT suppressed chemotaxis of primary human monocytes in a standard chemotaxis assay. (cdc.gov)
  • Chemotaxis, the motion of cells directed by a gradient of chemoattractant molecules, is difficult to measure. (nih.gov)
  • We have designed "open" chemotaxis devices that produce passive chemoattractant gradients without an external micropipette system. (cambridge.org)
  • No. 571406) (black circles) induces the chemotaxis of mouse Baf3-mCCR2 transfectant chemoattractant cells. (biolegend.com)
  • We also used cover slip microfluidics for chemotaxis assays. (cambridge.org)
  • Passive gradients elicited from these cover slips could be readily adapted for high throughput chemotaxis assays. (cambridge.org)
  • impaired macrophage activity and migration-chemotaxis, among many other devastating effects. (mold-help.org)
  • The research in the Chemotaxis Signal Section is focused on understanding the cellular and molecular mechanisms underlying chemotaxis of eukaryotes. (nih.gov)
  • Our research strategy to define the signaling network controlling chemotaxis relies on the use of the genetically amendable model organism Dictyostelium discoideum . (nih.gov)
  • Thymoquinone effect on the Dictyostelium discoideum model correlates with functional roles for glutathione S-transferases in eukaryotic proliferation, chemotaxis, and development. (bvsalud.org)
  • These notes are focused on the study of nematodes and on the chemotaxis of bacteria. (nih.gov)