Enterotoxigenic Escherichia coli
Strains of ESCHERICHIA COLI that produce or contain at least one member of either heat-labile or heat-stable ENTEROTOXINS. The organisms colonize the mucosal surface of the small intestine and elaborate their enterotoxins causing DIARRHEA. They are mainly associated with tropical and developing countries and affect susceptible travelers to those places.
Enterotoxins
Substances that are toxic to the intestinal tract causing vomiting, diarrhea, etc.; most common enterotoxins are produced by bacteria.
Escherichia coli Proteins
Proteins obtained from ESCHERICHIA COLI.
Escherichia coli Infections
Infections with bacteria of the species ESCHERICHIA COLI.
Fimbriae Proteins
Proteins that are structural components of bacterial fimbriae (FIMBRIAE, BACTERIAL) or sex pili (PILI, SEX).
Escherichia coli
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.
Escherichia coli Vaccines
Vaccines or candidate vaccines used to prevent or treat both enterotoxigenic and enteropathogenic Escherichia coli infections.
Diarrhea
Bacterial Toxins
Toxic substances formed in or elaborated by bacteria; they are usually proteins with high molecular weight and antigenicity; some are used as antibiotics and some to skin test for the presence of or susceptibility to certain diseases.
Fimbriae, Bacterial
Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).
Adhesins, Escherichia coli
Thin, filamentous protein structures, including proteinaceous capsular antigens (fimbrial antigens), that mediate adhesion of E. coli to surfaces and play a role in pathogenesis. They have a high affinity for various epithelial cells.
Bacterial Adhesion
Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.
Swine Diseases
Diseases of domestic swine and of the wild boar of the genus Sus.
Swine
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Feces
Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
Molecular Sequence Data
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.
Plasmids
Hemagglutination
The aggregation of ERYTHROCYTES by AGGLUTININS, including antibodies, lectins, and viral proteins (HEMAGGLUTINATION, VIRAL).
Serotyping
Base Sequence
Amino Acid Sequence
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.
Escherichia coli O157
A verocytotoxin-producing serogroup belonging to the O subfamily of Escherichia coli which has been shown to cause severe food-borne disease. A strain from this serogroup, serotype H7, which produces SHIGA TOXINS, has been linked to human disease outbreaks resulting from contamination of foods by E. coli O157 from bovine origin.
Bacterial Vaccines
Antigens, Surface
Cloning, Molecular
Gene Expression Regulation, Bacterial
Virulence Factors
Those components of an organism that determine its capacity to cause disease but are not required for its viability per se. Two classes have been characterized: TOXINS, BIOLOGICAL and surface adhesion molecules that effect the ability of the microorganism to invade and colonize a host. (From Davis et al., Microbiology, 4th ed. p486)
Travel
Aspects of health and disease related to travel.
Bangladesh
I'm sorry for any confusion, but "Bangladesh" is a country located in South Asia, not a medical term or concept. Therefore, it doesn't have a medical definition. It shares borders with India, Myanmar (Burma), and Bay of Bengal. The population is primarily Bengali, and the official language is Bangla (Bengali). The capital city is Dhaka. If you have any questions related to medicine or health, feel free to ask!
Colostrum
Mutation
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.
Hot Temperature
Presence of warmth or heat or a temperature notably higher than an accustomed norm.
Intestine, Small
The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.
Bacterial Outer Membrane Proteins
Intestinal Mucosa
Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.
Egypt
Cholera Toxin
An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells, and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.
Escherichia coli K12
A species of gram-negative, rod-shaped bacteria belonging to the K serogroup of ESCHERICHIA COLI. It lives as a harmless inhabitant of the human LARGE INTESTINE and is widely used in medical and GENETIC RESEARCH.
Virulence
The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.
Shigella
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that ferments sugar without gas production. Its organisms are intestinal pathogens of man and other primates and cause bacillary dysentery (DYSENTERY, BACILLARY).
Vibrio cholerae
The etiologic agent of CHOLERA.
Intestines
Operon
In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.
Toxoids
Preparations of pathogenic organisms or their derivatives made nontoxic and intended for active immunologic prophylaxis. They include deactivated toxins. Anatoxin toxoids are distinct from anatoxins that are TROPANES found in CYANOBACTERIA.
Nucleic Acid Hybridization
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
Adhesins, Bacterial
Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.
Ileum
Immunoglobulin A
Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.
Enzyme-Linked Immunosorbent Assay
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
Food Microbiology
Polymerase Chain Reaction
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Receptors, Guanylate Cyclase-Coupled
Cattle
Microscopy, Electron
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
Bacterial Shedding
Antitoxins
Antisera from immunized animals that is purified and used as a passive immunizing agent against specific BACTERIAL TOXINS.
Biological Assay
A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.
Animals, Suckling
Culture Media
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Bolivia
I'm sorry for any confusion, but "Bolivia" is not a medical term that has a definition in the field of medicine. It is actually the name of a country, specifically the Plurinational State of Bolivia, located in South America. If you have any questions related to medicine or health, I would be happy to try and help answer those for you!
Conjugation, Genetic
A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.
Electrophoresis, Polyacrylamide Gel
Rabbits
Chimerin Proteins
O Antigens
The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the intact bacterial cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Hemagglutination Tests
Agglutination Tests
Vaccines, Inactivated
Vaccines in which the infectious microbial nucleic acid components have been destroyed by chemical or physical treatment (e.g., formalin, beta-propiolactone, gamma radiation) without affecting the antigenicity or immunogenicity of the viral coat or bacterial outer membrane proteins.
Bromelains
Cholera
An acute diarrheal disease endemic in India and Southeast Asia whose causative agent is VIBRIO CHOLERAE. This condition can lead to severe dehydration in a matter of hours unless quickly treated.
Ships
Restriction Mapping
Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.
Egg Yolk
Water Microbiology
Cattle Diseases
Diseases of domestic cattle of the genus Bos. It includes diseases of cows, yaks, and zebus.
Species Specificity
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Immunodiffusion
Sequence Analysis, DNA
Chromosomes, Bacterial
Caco-2 Cells
Mannose
Binding Sites
RNA, Bacterial
Immunity, Mucosal
Nonsusceptibility to the pathogenic effects of foreign microorganisms or antigenic substances as a result of antibody secretions of the mucous membranes. Mucosal epithelia in the gastrointestinal, respiratory, and reproductive tracts produce a form of IgA (IMMUNOGLOBULIN A, SECRETORY) that serves to protect these ports of entry into the body.
Vaccines, Synthetic
Random Amplified Polymorphic DNA Technique
Technique that utilizes low-stringency polymerase chain reaction (PCR) amplification with single primers of arbitrary sequence to generate strain-specific arrays of anonymous DNA fragments. RAPD technique may be used to determine taxonomic identity, assess kinship relationships, analyze mixed genome samples, and create specific probes.
Disease Outbreaks
Immunization
Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).
Cholera Vaccines
Vaccines or candidate vaccines used to prevent infection with VIBRIO CHOLERAE. The original cholera vaccine consisted of killed bacteria, but other kinds of vaccines now exist.
Enterobacteriaceae
A family of gram-negative, facultatively anaerobic, rod-shaped bacteria that do not form endospores. Its organisms are distributed worldwide with some being saprophytes and others being plant and animal parasites. Many species are of considerable economic importance due to their pathogenic effects on agriculture and livestock.
Dysentery, Bacillary
DYSENTERY caused by gram-negative rod-shaped enteric bacteria (ENTEROBACTERIACEAE), most often by the genus SHIGELLA. Shigella dysentery, Shigellosis, is classified into subgroups according to syndrome severity and the infectious species. Group A: SHIGELLA DYSENTERIAE (severest); Group B: SHIGELLA FLEXNERI; Group C: SHIGELLA BOYDII; and Group D: SHIGELLA SONNEI (mildest).
Immune Sera
Phenotype
Amino Acids
Thailand
Recombinant Fusion Proteins
DNA Probes
Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.
Colony Count, Microbial
Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.
Immunoglobulin G
Immunoglobulin A, Secretory
The principle immunoglobulin in exocrine secretions such as milk, respiratory and intestinal mucin, saliva and tears. The complete molecule (around 400 kD) is composed of two four-chain units of IMMUNOGLOBULIN A, one SECRETORY COMPONENT and one J chain (IMMUNOGLOBULIN J-CHAINS).
Coliphages
Viruses whose host is Escherichia coli.
Weaning
Enteropathogenic Escherichia coli
Strains of ESCHERICHIA COLI characterized by attaching-and-effacing histopathology. These strains of bacteria intimately adhere to the epithelial cell membrane and show effacement of microvilli. In developed countries they are associated with INFANTILE DIARRHEA and infantile GASTROENTERITIS and, in contrast to ETEC strains, do not produce ENDOTOXINS.
Genes
Mexico
I'm sorry for any confusion, but "Mexico" is not a medical term and does not have a medical definition. It is the name of a country located in North America, known officially as the United Mexican States. If you have any questions related to medical topics or terminology, I would be happy to help answer those!
Microbial Sensitivity Tests
Shigella flexneri
A bacterium which is one of the etiologic agents of bacillary dysentery (DYSENTERY, BACILLARY) and sometimes of infantile gastroenteritis.
Bacteroides fragilis
Protein Binding
Sequence Homology, Amino Acid
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Vaccines, Attenuated
Live vaccines prepared from microorganisms which have undergone physical adaptation (e.g., by radiation or temperature conditioning) or serial passage in laboratory animal hosts or infected tissue/cell cultures, in order to produce avirulent mutant strains capable of inducing protective immunity.
Genetic Complementation Test
Sequence Homology, Nucleic Acid
Gastroenteritis
INFLAMMATION of any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM. Causes of gastroenteritis are many including genetic, infection, HYPERSENSITIVITY, drug effects, and CANCER.
Peru
I'm sorry for any confusion, but "Peru" is not a medical term or concept, it is a country located in South America, known officially as the Republic of Peru. If you have any questions about medical topics that I can help clarify, please let me know!
Rotavirus Infections
Temperature
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Immunization, Passive
Drug Resistance, Bacterial
Shiga-Toxigenic Escherichia coli
Strains of ESCHERICHIA COLI with the ability to produce at least one or more of at least two antigenically distinct, usually bacteriophage-mediated cytotoxins: SHIGA TOXIN 1 and SHIGA TOXIN 2. These bacteria can cause severe disease in humans including bloody DIARRHEA and HEMOLYTIC UREMIC SYNDROME.
Protein Subunits
Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.
Rotavirus
A genus of REOVIRIDAE, causing acute gastroenteritis in BIRDS and MAMMALS, including humans. Transmission is horizontal and by environmental contamination. Seven species (Rotaviruses A thru G) are recognized.
Enterohemorrhagic Escherichia coli
Strains of ESCHERICHIA COLI that are a subgroup of SHIGA-TOXIGENIC ESCHERICHIA COLI. They cause non-bloody and bloody DIARRHEA; HEMOLYTIC UREMIC SYNDROME; and hemorrhagic COLITIS. An important member of this subgroup is ESCHERICHIA COLI O157-H7.
Cross Reactions
Genotype
Bacterial Typing Techniques
Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.
Mice, Inbred BALB C
Substrate Specificity
Electrophoresis, Gel, Pulsed-Field
Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.
Alkaline Phosphatase
Drug Resistance, Microbial
Escherichia
Transcription, Genetic
Colicins
Bacteriocins elaborated by strains of Escherichia coli and related species. They are proteins or protein-lipopolysaccharide complexes lethal to other strains of the same species.
Shiga Toxin 1
A toxin produced by certain pathogenic strains of ESCHERICHIA COLI such as ESCHERICHIA COLI O157. It is closely related to SHIGA TOXIN produced by SHIGELLA DYSENTERIAE.
Clostridium perfringens
Uropathogenic Escherichia coli
Strains of Escherichia coli that preferentially grow and persist within the urinary tract. They exhibit certain virulence factors and strategies that cause urinary tract infections.
Glycosphingolipids
Lipids containing at least one monosaccharide residue and either a sphingoid or a ceramide (CERAMIDES). They are subdivided into NEUTRAL GLYCOSPHINGOLIPIDS comprising monoglycosyl- and oligoglycosylsphingoids and monoglycosyl- and oligoglycosylceramides; and ACIDIC GLYCOSPHINGOLIPIDS which comprises sialosylglycosylsphingolipids (GANGLIOSIDES); SULFOGLYCOSPHINGOLIPIDS (formerly known as sulfatides), glycuronoglycosphingolipids, and phospho- and phosphonoglycosphingolipids. (From IUPAC's webpage)
Protein Conformation
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
beta-Galactosidase
A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.
Hydrogen-Ion Concentration
Chromosome Mapping
Any method used for determining the location of and relative distances between genes on a chromosome.
Models, Molecular
Adjuvants, Immunologic
Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.
Immunoelectrophoresis
A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
Immunoblotting
Mutagenesis, Site-Directed
Bacteriophage lambda
Seasons
Chloramphenicol
An antibiotic first isolated from cultures of Streptomyces venequelae in 1947 but now produced synthetically. It has a relatively simple structure and was the first broad-spectrum antibiotic to be discovered. It acts by interfering with bacterial protein synthesis and is mainly bacteriostatic. (From Martindale, The Extra Pharmacopoeia, 29th ed, p106)
DNA Transposable Elements
Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.
Microscopy, Electron, Transmission
Epithelial Cells
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Antibody Specificity
DNA Restriction Enzymes
Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.
DNA-Directed RNA Polymerases
Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).
Carrier Proteins
Antibodies, Neutralizing
Membrane Transport Proteins
Transduction, Genetic
The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a GENE TRANSFER TECHNIQUE.
Epithelium
One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.
Recombination, Genetic
Sequence Alignment
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.