F Factor: A plasmid whose presence in the cell, either extrachromosomal or integrated into the BACTERIAL CHROMOSOME, determines the "sex" of the bacterium, host chromosome mobilization, transfer via conjugation (CONJUGATION, GENETIC) of genetic material, and the formation of SEX PILI.Sex: The totality of characteristics of reproductive structure, functions, PHENOTYPE, and GENOTYPE, differentiating the MALE from the FEMALE organism.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.Extrachromosomal Inheritance: Vertical transmission of hereditary characters by DNA from cytoplasmic organelles such as MITOCHONDRIA; CHLOROPLASTS; and PLASTIDS, or from PLASMIDS or viral episomal DNA.AcridinesEscherichia 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.Genetics, Microbial: A subdiscipline of genetics which deals with the genetic mechanisms and processes of microorganisms.Coliphages: Viruses whose host is Escherichia coli.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Lactose: A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Sex Factors: Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.R Factors: A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.Sex Characteristics: Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Lysogeny: The phenomenon by which a temperate phage incorporates itself into the DNA of a bacterial host, establishing a kind of symbiotic relation between PROPHAGE and bacterium which results in the perpetuation of the prophage in all the descendants of the bacterium. Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium.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.Crosses, Genetic: Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.Lactococcus lactis: A non-pathogenic species of LACTOCOCCUS found in DAIRY PRODUCTS and responsible for the souring of MILK and the production of LACTIC ACID.Drug Resistance, Microbial: The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).DNA, Circular: Any of the covalently closed DNA molecules found in bacteria, many viruses, mitochondria, plastids, and plasmids. Small, polydisperse circular DNA's have also been observed in a number of eukaryotic organisms and are suggested to have homology with chromosomal DNA and the capacity to be inserted into, and excised from, chromosomal DNA. It is a fragment of DNA formed by a process of looping out and deletion, containing a constant region of the mu heavy chain and the 3'-part of the mu switch region. Circular DNA is a normal product of rearrangement among gene segments encoding the variable regions of immunoglobulin light and heavy chains, as well as the T-cell receptor. (Riger et al., Glossary of Genetics, 5th ed & Segen, Dictionary of Modern Medicine, 1992)Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.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.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.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.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.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.Bacterial Proteins: Proteins found in any species of bacterium.Chromosomes: In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Sex Chromosomes: The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Sex Determination Processes: The mechanisms by which the SEX of an individual's GONADS are fixed.Unsafe Sex: Sexual behaviors which are high-risk for contracting SEXUALLY TRANSMITTED DISEASES or for producing PREGNANCY.Genes, Bacterial: The functional hereditary units of BACTERIA.Sex Workers: People who engage in occupational sexual behavior in exchange for economic rewards or other extrinsic considerations.Sex Differentiation: The process in developing sex- or gender-specific tissue, organ, or function after SEX DETERMINATION PROCESSES have set the sex of the GONADS. Major areas of sex differentiation occur in the reproductive tract (GENITALIA) and the brain.Safe Sex: Sexual behavior that prevents or reduces the spread of SEXUALLY TRANSMITTED DISEASES or PREGNANCY.Sex Attractants: Pheromones that elicit sexual attraction or mating behavior usually in members of the opposite sex in the same species.Sex Determination Analysis: Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.Sex Distribution: The number of males and females in a given population. The distribution may refer to how many men or women or what proportion of either in the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.Disorders of Sex Development: In gonochoristic organisms, congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Effects from exposure to abnormal levels of GONADAL HORMONES in the maternal environment, or disruption of the function of those hormones by ENDOCRINE DISRUPTORS are included.Sex Preselection: Methods for controlling genetic SEX of offspring.Sex Hormone-Binding Globulin: A glycoprotein migrating as a beta-globulin. Its molecular weight, 52,000 or 95,000-115,000, indicates that it exists as a dimer. The protein binds testosterone, dihydrotestosterone, and estradiol in the plasma. Sex hormone-binding protein has the same amino acid sequence as ANDROGEN-BINDING PROTEIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.Sex Counseling: Advice and support given to individuals to help them understand and resolve their sexual adjustment problems. It excludes treatment for PSYCHOSEXUAL DISORDERS or PSYCHOSEXUAL DYSFUNCTION.Gonadal Steroid Hormones: Steroid hormones produced by the GONADS. They stimulate reproductive organs, germ cell maturation, and the secondary sex characteristics in the males and the females. The major sex steroid hormones include ESTRADIOL; PROGESTERONE; and TESTOSTERONE.Prostitution: The practice of indulging in sexual relations for money.Homosexuality, Male: Sexual attraction or relationship between males.Sex Education: Education which increases the knowledge of the functional, structural, and behavioral aspects of human reproduction.Sexual Behavior: Sexual activities of humans.
Acridine carboxamide: Acridine carboxamide is an chemotherapy agent that is being studied in the treatment of cancer. It belongs to the family of drugs called topoisomerase inhibitors.List of strains of Escherichia coli: Escherichia coli is a well studied bacterium that was first identified by Theodor Escherich, after whom it was later named.Enterobacteria phage G4: Enterobacteria phage G4 is a bacteriophage capable of infecting susceptible bacterial cells. The phage was originally isolated from samples of raw sewage and infects E.Circular bacterial chromosome: A circular bacterial chromosome is a bacterial chromosome in the form of a molecule of circular DNA. Unlike the linear DNA of most eukaryotes, typical bacterial chromosomes are circular.AllolactoseRecombination (cosmology): In cosmology, recombination refers to the epoch at which charged electrons and protons first became bound to form electrically neutral hydrogen atoms.Note that the term recombination is a misnomer, considering that it represents the first time that electrically neutral hydrogen formed.Lambda phageSilent mutation: Silent mutations are mutations in DNA that do not significantly alter the phenotype of the organism in which they occur. Silent mutations can occur in non-coding regions (outside of genes or within introns), or they may occur within exons.ActoBiotics: ActoBiotics (a registered trademark) consist of food-grade bacteria (Lactococcus lactis), genetically engineered to synthesize and secrete therapeutic proteins and peptides in situ. ActoBiotics are delivered to patients via oral administration instead of injection, and specifically target receptors and cells localized in gastrointestinal (GI) tissues.CccDNA: cccDNA (covalently closed circular DNA) is a special DNA structure that arises during the propagation of some viruses in the cell nucleus and may remain permanently there. It is a double-stranded DNA that originates in a linear form that is ligated by means of DNA ligase to a covalently closed ring.Triparental mating: Triparental mating is a form of Bacterial conjugation where a conjugative plasmid present in one bacterial strain assists the transfer of a mobilizable plasmid present in a second bacterial strain into a third bacterial strain. Plasmids are introduced into bacteria for such purposes as transformation, cloning, or transposon mutagenesis.Eagle's minimal essential medium: Eagle's minimal essential medium (EMEM) is a cell culture medium developed by Harry Eagle that can be used to maintain cells in tissue culture.Chromosome regionsRestriction fragment: A restriction fragment is a DNA fragment resulting from the cutting of a DNA strand by a restriction enzyme (restriction endonucleases), a process called restriction. Each restriction enzyme is highly specific, recognising a particular short DNA sequence, or restriction site, and cutting both DNA strands at specific points within this site.Operon: In genetics, an operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create monocistronic mRNAs that are translated separately, i.Ferric uptake regulator family: In molecular biology, the ferric uptake regulator (FUR) family of proteins includes metal ion uptake regulator proteins. These are responsible for controlling the intracellular concentration of iron in many bacteria.Premature chromosome condensation: Premature chromosome condensation (PCC) occurs in eukaryotic organisms when mitotic cells fuse with interphase cells. Chromatin, a substance that contains genetic material such as DNA, is normally found in a loose bundle inside a cell's nucleus.Suresh Jayakar: Suresh Dinakar Jayakar (21 September 1937, Bombay-21 January 1988) was an Indian biologist who pioneered in the use of quantitative approaches in genetics and biology.List of diseases (M): This is a list of diseases starting with the letter "M".Controlling Vice: Regulating Brothel Prostitution in St. Paul, 1865-1883: Controlling Vice is a book by Minnesotan author Joel Best, published in 1998. It is the story of the strategies that the Minnesota police officers enforced in attempts to regulate prostitution in the late nineteenth century.
(1/28941) Regional survey of femoral neck fractures.
In the South-west Thames Region 2619 patients (2105 women and 514 men) were discharged with a diagnosis of femoral neck fracture in 1974. The equivalent of a 250-bedded hospital was occupied throughout the year. The incidence, average length of stay, and mortality rate rose with increasing age and there were differences in these indices in the five health areas. These results confirm the enormous burden placed on the hospital service by patients with fracture of the femoral neck but suggest that differences in practice in the five areas may contribute to the size of the problem. (+info)
(2/28941) Determination of human body burden baseline date of platinum through autopsy tissue analysis.
Results of analysis for platinum in 97 autopsy sets are presented. Analysis was performed by a specially developed emission spectrochemical method. Almost half of the individuals studied were found to have detectable platinum in one or more tissue samples. Platinum was found to be deposited in 13 of 21 tissue types investigated. Surprisingly high values were observed in subcutaneous fat, previously not considered to be a target site for platinum deposition. These data will serve as a human tissue platinum burden baseline in EPA's Catalyst Research Program. (+info)
(3/28941) A quantitative three-dimensional model of the Drosophila optic lobes.
A big step in the neurobiology of Drosophila would be to establish a standard for brain anatomy to which to relate morphological, developmental and genetic data. We propose that only an average brain and its variance would be a biologically meaningful reference and have developed an averaging procedure. Here, we present a brief outline of this method and apply it to the optic lobes of Drosophila melanogaster wild-type Canton S. Whole adult brains are stained with a fluorescent neuropil marker and scanned with the confocal microscope. The resulting three-dimensional data sets are automatically aligned into a common coordinate system and intensity averages calculated. We use effect-size maps for the fast detection of differences between averages. For morphometric analysis, neuropil structures are labelled and superimposed to give a three-dimensional probabilistic map. In the present study, the method was applied to 66 optic lobes. We found their size, shape and position to be highly conserved between animals. Similarity was even higher between left and right optic lobes of the same animal. Sex differences were more pronounced. Female optic lobes were 6% larger than those of males. This value corresponds well with the higher number of ommatidia in females. As females have their additional ommatidia dorsally and ventrally, the additional neuropil in the medulla, lobula and lobula plate, accordingly, was found preferentially at these locations. For males, additional neuropil was found only at the posterior margin of the lobula. This finding supports the notion of male-specific neural processing in the lobula as described for muscid and calliphorid flies. (+info)
(4/28941) Expression of Bcl-2 protein is decreased in colorectal adenocarcinomas with microsatellite instability.
Bcl-2 is known to inhibit apoptosis and is thought to play a role in colorectal tumour development. Studies of the promoter region of bcl-2 have indicated the presence of a p53 responsive element which downregulates bcl-2 expression. Since p53 is commonly mutated in colorectal cancers, but rarely in those tumours showing microsatellite instability (MSI), the aim of this study was to examine the relationship of bcl-2 protein expression to MSI, as well as to other clinicopathological and molecular variables, in colorectal adenocarcinomas. Expression of bcl-2 was analysed by immunohistochemistry in 71 colorectal cancers which had been previously assigned to three classes depending upon their levels of MSI. MSI-high tumours demonstrated instability in three or more of six microsatellite markers tested, MSI-low tumours in one or two of six, and MSI-null in none of six. Bcl-2 expression in tumours was quantified independently by two pathologists and assigned to one of five categories, with respect to the number of cells which showed positive staining: 0, up to 5%; 1, 6-25%; 2, 26-50%; 3, 51-75%; and 4, > or =76%. Bcl-2 negative tumours were defined as those with a score of 0. Bcl-2 protein expression was tested for association with clinicopathological stage, differentiation level, tumour site, age, sex, survival, evidence of p53 inactivation and MSI level. A significant association was found between bcl-2 expression and patient survival (P = 0.012, Gehan Wilcoxon test). Further, a significant reciprocal relationship was found between bcl-2 expression and the presence of MSI (P = 0.012, Wilcoxon rank sum test). We conclude that bcl-2 expressing colorectal cancers are more likely to be MSI-null, and to be associated with improved patient survival. (+info)
(5/28941) Dietary intake and practices in the Hong Kong Chinese population.
OBJECTIVES: To examine dietary intake and practices of the adult Hong Kong Chinese population to provide a basis for future public health recommendations with regard to prevention of certain chronic diseases such as cardiovascular disease, hypertension, and osteoporosis. PARTICIPANTS: Age and sex stratified random sample of the Hong Kong Chinese population aged 25 to 74 years (500 men, 510 women). METHOD: A food frequency method over a one week period was used for nutrient quantification, and a separate questionnaire was used for assessment of dietary habits. Information was obtained by interview. RESULTS: Men had higher intakes of energy and higher nutrient density of vitamin D, monounsaturated fatty acids and cholesterol, but lower nutrient density of protein, many vitamins, calcium, iron, copper, and polyunsaturated fatty acids. There was an age related decrease in energy intake and other nutrients except for vitamin C, sodium, potassium, and percentage of total calorie from carbohydrate, which all increased with age. Approximately 50% of the population had a cholesterol intake of < or = 300 mg; 60% had a fat intake < or = 30% of total energy; and 85% had a percentage of energy from saturated fats < or = 10%; criteria considered desirable for cardiovascular health. Seventy eight per cent of the population had sodium intake values in the range shown to be associated with the age related rise in blood pressure with age. Mean calcium intake was lower than the FAO/WHO recommendations. The awareness of the value of wholemeal bread and polyunsaturated fat spreads was lower in this population compared with that in Australia. There was a marked difference in types of cooking oil compared with Singaporeans, the latter using more coconut/palm/mixed vegetable oils. CONCLUSION: Although the current intake pattern for cardiovascular health for fat, saturated fatty acid, and cholesterol fall within the recommended range for over 50% of the population, follow up surveys to monitor the pattern would be needed. Decreasing salt consumption, increasing calcium intake, and increasing the awareness of the health value of fibre may all be beneficial in the context of chronic disease prevention. (+info)
(6/28941) The five amino acid-deleted isoform of hepatocyte growth factor promotes carcinogenesis in transgenic mice.
Hepatocyte growth factor (HGF) is a polypeptide with mitogenic, motogenic, and morphogenic effects on different cell types including hepatocytes. HGF is expressed as two biologically active isotypes resulting from alternative RNA splicing. The roles of each HGF isoform in development, liver regeneration and tumorigenesis have not yet been well characterized. We report the generation and analysis of transgenic mice overexpressing the five amino acid-deleted variant of HGF (dHGF) in the liver by virtue of an albumin expression vector. These ALB-dHGF transgenic mice develop normally, have an enhanced rate of liver regeneration after partial hepatectomy, and exhibit a threefold higher incidence of hepatocellular carcinoma (HCC) beyond 17 months of age. Moreover, overexpression of dHGF dramatically accelerates diethyl-nitrosamine induced HCC tumorigenesis. These tumors arise faster, are significantly larger, more numerous and more invasive than those appearing in non-transgenic littermates. Approximately 90% of female dHGF-transgenic mice had multiple macroscopic HCCs 40 weeks after injection of DEN; whereas the non-transgenic counterparts had only microscopic nodules. Liver tumors and cultured tumor cell lines from dHGF transgenics showed high levels of HGF and c-Met mRNA and protein. Together, these results reveal that in vivo dHGF plays an active role in liver regeneration and HCC tumorigenesis. (+info)
(7/28941) Cardiovascular disease in insulin dependent diabetes mellitus: similar rates but different risk factors in the US compared with Europe.
BACKGROUND: Cardiovascular disease (CVD) in insulin dependent diabetes mellitus (IDDM) has been linked to renal disease. However, little is known concerning international variation in the correlations with hyperglycaemia and standard CVD risk factors. METHODS: A cross-sectional comparison was made of prevalence rates and risk factor associations in two large studies of IDDM subjects: the Pittsburgh Epidemiology of Diabetes Complications Study (EDC) and the EURODIAB IDDM Complications Study from 31 centres in Europe. Subgroups of each were chosen to be comparable by age and duration of diabetes. The EDC population comprises 286 men (mean duration 20.1 years) and 281 women (mean duration 19.9 years); EURODIAB 608 men (mean duration 18.1 years) and 607 women (mean duration 18.9 years). The mean age of both populations was 28 years. Cardiovascular disease was defined by a past medical history of myocardial infarction, angina, and/or the Minnesota ECG codes (1.1-1.3, 4.1-4.3, 5.1-5.3, 7.1). RESULTS: Overall prevalence of CVD was similar in the two populations (i.e. men 8.6% versus 8.0%, women 7.4% versus 8.5%, EURODIAB versus EDC respectively), although EDC women had a higher prevalence of angina (3.9% versus 0.5%, P < 0.001). Multivariate modelling suggests that glycaemic control (HbA1c) is not related to CVD in men. Age and high density lipoprotein cholesterol predict CVD in EURODIAB, while triglycerides and hypertension predict CVD in EDC. For women in both populations, age and hypertension (or renal disease) are independent predictors. HbA1c is also an independent predictor-inversely in EURODIAB women (P < 0.008) and positively in EDC women (P = 0.03). Renal disease was more strongly linked to CVD in EDC than in EURODIAB. CONCLUSIONS: Despite a similar prevalence of CVD, risk factor associations appear to differ in the two study populations. Glycaemic control (HbA1c) does not show a consistent or strong relationship to CVD. (+info)
(8/28941) Heart rate and subsequent blood pressure in young adults: the CARDIA study.
The objective of the present study was to examine the hypothesis that baseline heart rate (HR) predicts subsequent blood pressure (BP) independently of baseline BP. In the multicenter longitudinal Coronary Artery Risk Development in Young Adults study of black and white men and women initially aged 18 to 30 years, we studied 4762 participants who were not current users of antihypertensive drugs and had no history of heart problems at the baseline examination (1985-1986). In each race-sex subgroup, we estimated the effect of baseline HR on BP 2, 5, 7, and 10 years later by use of repeated measures regression analysis, adjusting for baseline BP, age, education, body fatness, physical fitness, fasting insulin, parental hypertension, cigarette smoking, alcohol consumption, oral contraceptive use, and change of body mass index from baseline. The association between baseline HR and subsequent systolic BP (SBP) was explained by multivariable adjustment. However, HR was an independent predictor of subsequent diastolic BP (DBP) regardless of initial BP and other confounders in white men, white women, and black men (0.7 mm Hg increase per 10 bpm). We incorporated the part of the association that was already present at baseline by not adjusting for baseline DBP: the mean increase in subsequent DBP was 1.3 mm Hg per 10 bpm in white men, white women, and black men. A high HR may be considered a risk factor for subsequent high DBP in young persons. (+info)
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