Gram stain method shows better sensitivity than clinical criteria for detection of bacterial vaginosis in surveillance of pregnant, low-income women in a clinical setting

OBJECTIVE: The purpose of the study is to determine whether the Gram stain method is superior to the clinical criteria for the diagnosis of bacterial vaginosis in low-income pregnant women seen in a resident clinic setting. The clinical criteria is the current diagnostic method employed to diagnose bacterial vaginosis. STUDY DESIGN: In this study, 51 pregnant women with vaginal discharge were prospectively evaluated. All were screened using the clinical criteria, Gram stain method, and culture of the discharge. The modified scoring system instituted by Nugent et al. (J Clin Microbiol 29:297-301, 1991) was employed in reading the Gram stain smears. The clinical criteria were then compared with the Gram stain method. Isolation of moderate to many Gardnerella vaginalis growth by culture was used as the confirmatory finding. RESULTS: Sensitivity of the Gram stain method (91%) was significantly higher than that of the clinical criteria (46%), (sign test P = 0.0023, < 0.01). The Gram stain method also has both a low false-negative (4%) and high negative predictive value (96%), making it an ideal diagnostic test. CONCLUSION: The Gram stain method is a rapid and cost-effective test that is also highly reproducible and readily available in many laboratories. These features make the Gram stain method a more desirable screening procedure for bacterial vaginosis in a clinic population.     

The application of the 32P-postlabelling assay to aquatic biomonitoring

In present study, lipid peroxidation products (thiobarbituric acid reactive substances (TBARS) and diene conjugates (DC)) and markers of blood antioxidant status (serum antioxidative capacity (AOC) and red blood cells glutathione (RBC-GSH)) were measured to compare the extent of oxidative stress in 12 cardiac surgery and 10 septic general surgery patients. In heart surgery, arterial TBARS were significantly increased 15 min after the start and 15 min after cessation of cardiopulmonary bypass, while AOC at these times was decreased. Eighteen hours after surgery all parameters, except antioxidative capacity, had returned to preoperative levels. In septic patients, the preoperative level of lipid peroxidation was significantly higher and antioxidative capacity lower than in heart surgery patients. Surgery had no influence on oxidative stress markers in this group of patients. Increase in lipid peroxidation and reduction in blood antioxidant capacity, induced either by sepsis or cardiopulmonary bypass, were of comparable extent.     

Calculation method of equilibrium composition in the carbon-hydrogen-oxygen system and its application to environments of a high-temperature gas-cooled reactor

A simple method for calculation of high-temperature equilibrium composition has been developed for the C-H-O system of the species H₂, H₂O, CO, CO₂, CH₄, O₂, and solid C. The calculation process has been simplified by using the most fundamental equilibria for high-temperature reactions of gaseous species. This method is applied for cases of carbon activity equal to or less than 1 using the identical equilibria. We have also applied the method to two kinds of gases for a high-temperature gas-cooled reactor, which are an impure helium gas for the reactor coolant and a reducing gas for the utility system of the reactor. Characteristics of these gases are discussed from the viewpoint of corrosion and hydrogen permeation of the reactor materials. Formerly with Nuclear Materials Division     

Inversion polymorphism in natural populations of Drosophila bipectinata

Inversion polymorphism was studied in seven natural populations of Drosophila bipectinata, five from northern and two from southern India. Chromosomal analysis of these populations revealed the presence of three paracentric inversions which are widespread in populations of D. bipectinata. Quantitative data indicated that the frequency of inversions and the level of inversion heterozygosity were very low in populations of D. bipectinata. There is no evidence for genetic differentiation between populations as a result of inversion polymorphism. These findings provide evidence for rigid chromosomal polymorphism in D. bipectinata. Significant non-random associations between inversions indicated epistatic interaction between inversions in natural populations of D. bipectinata.     

The defensive function of cyanogenesis in natural populations

Detailed ecological studies of some maritime populations of Lotus corniculatus L. have shown that the distribution of the cyanogenic form of this plant is directly related to the distribution and density of molluscs which graze selectively the acyanogenic form. This work, on a genetic polymorphism, is interpreted as giving direct evidence of chemical defence in natural populations.     

Specific lipid protein interactions characterize 3 populations of clathrin coated vesicles involved in the LDL receptor traffic

We have previously isolated 3 different populations of clathrin coated vesicles (CCV) involved in the LDL-receptor traffic in bovine adrenal cortex. We now show that each CCV type contains the transferrin-R and the CI-MPR, therefore, they provide a good model for studying the membrane organization that may govern their targeting in one of the biosynthetic, endocytic and/or recycling pathways. Transferrin--prototype of recylcing ligand--, and alpha adaptin, dynamin and the 110 kDa phosphatidylinositol-3-kinase subunit--of the trafficking machinery--were mainly detected in only 2 of the vesicle populations which could be involved in the endocytic/recycling pathway. The third population which contained larger amounts of gamma adaptin and do not carry transferrin could be involved in the biosynthetic pathway. The vesicle lipid pattern and the saturation of their fatty acyl chains were analyzed and confirmed these results. The nature of the interactions between vesicle components was then determined using several classes of detergents. Only non ionic ones could solubilize the LDL-R in a complex with either alpha or gamma adaptin. In contrast, they dissociated clathrin or beta-beta' adaptins. Taken together these results prompt us to suggest an integrated model for targeting in membrane traffic. Besides specific targeting signals carried by cargo proteins and recognized by proteins from the coat and the cytosolic trafficking machinery, lipids would play a key modulatory role. At each step in the membrane traffic, the proteins which carry multiple targeting signals would interact transiently with a specific set of lipids. This would result in the exposure of the appropriate targeting signals which could now become recognized by the proper targeting machinery.     

Use of differential subtraction method to identify genes that characterize the phenotype of cultured rheumatoid arthritis synoviocytes

OBJECTIVE: To identify the genes that characterize the distinctive phenotype of cultured rheumatoid arthritis (RA) fibroblastoid synoviocytes. METHODS: A representational difference method was used to subtract complementary DNA (cDNA) from cultured RA fibroblastoid synoviocytes with cDNA from noninflammatory osteoarthritis synoviocytes. The genes were identified by DNA sequencing, and their relative expression was determined by Northern blot analysis. RESULTS: Twenty-four genes were identified, including novel genes such as a human homolog of mouse semaphorin E and one homologous to N-acetylglucosamine-6-sulfatase. Eleven of these genes were constitutively overexpressed in the rheumatoid synoviocyte line, including a chemokine, stromal cell-derived factor 1, and several genes capable of mediating synoviocyte-leukocyte interactions, including vascular cell adhesion molecule 1 and Mac-2 binding protein. Three genes (lumican, biglycan, and insulin-like growth factor binding protein 5) encoded extracellular matrix components, suggesting that distinct stromal-synoviocyte interactions may be mediated by this phenotype. Two interferon-inducible genes of unknown function were also found, emphasizing the presence of activation-like features in the phenotype. CONCLUSION: A general method for the identification of differences in patterns of gene expression revealed that cultured RA fibroblastoid synoviocytes overexpress certain proinflammatory genes that are potentially relevant to lymphocyte and monocyte entry and interactions. The features of the genes identified in these mesenchymal cells suggest that they facilitate localization of immune reactions to the joint through leukocyte chemokinesis, cell-cell adhesion, and matrix specialization. The further characterization of these genes should help in resolving whether this phenotype is the consequence of modulation and imprinting by an inflammatory milieu or, more likely, whether it reflects the intrinsic lineage characteristics of intimal lining synoviocytes.     

Genetic diversity in natural populations of New World Leishmania

BACKGROUND: Monoclonal precancerous cells undergo successive biochemical and genetic changes during the multistep process of carcinogenesis in the gastrointestinal tract. Despite a high association with intestinal-type stomach cancer (differentiated adenocarcinoma of the stomach), the role of intestinal metaplasia is unclear in stomach carcinogenesis. AIMS: To study the clonality of intestinal metaplasia. METHODS: The clonality of 86 single intestinal metaplastic glands isolated by EDTA treatment from gastrectomy specimens from patients with cancer were investigated. The methylation sensitive restriction enzyme HpaII and polymerase chain reaction (PCR) were used to detect a polymorphic human androgen receptor gene locus linked to an inactive X chromosome. RESULTS: Forty one (48%) intestinal metaplastic glands were heterotypic (mixed cells of different allelic methylation) and 45 (52%) were homotypic (cell population of the same allelic methylation), while almost all the single pyloric glands were homotypic. Eleven of 13 intestinal metaplastic mucosae that were 6 mm in diameter contained glands that had originated from different cells. There were no strong relationships between clonal type and location or histological type of intestinal metaplasia. CONCLUSION: Intestinal metaplasia in general is not a lesion that arises or proceeds monoclonally.     

Factors affecting levels of genetic diversity in natural populations

Genetic variability is the clay of evolution, providing the base material on which adaptation and speciation depend. It is often assumed that most interspecific differences in variability are due primarily to population size effects, with bottlenecked populations carrying less variability than those of stable size. However, we show that population bottlenecks are unlikely to be the only factor, even in classic case studies such as the northern elephant seal and the cheetah, where genetic polymorphism is virtually absent. Instead, we suggest that the low levels of variability observed in endangered populations are more likely to result from a combination of publication biases, which tend to inflate the level of variability which is considered 'normal', and inbreeding effects, which may hasten loss of variability due to drift. To account for species with large population sizes but low variability we advance three hypotheses. First, it is known that certain metapopulation structures can result in effective population sizes far below the census size. Second, there is increasing evidence that heterozygous sites mutate more frequently than equivalent homozygous sites, plausibly because mismatch repair between homologous chromosomes during meiosis provides extra opportunities to mutate. Such a mechanism would undermine the simple relationship between heterozygosity and effective population size. Third, the fact that related species that differ greatly in variability implies that large amounts of variability can be gained or lost rapidly. We argue that such cases are best explained by rapid loss through a genome-wide selective sweep, and suggest a mechanism by which this could come about, based on forced changes to a control gene inducing coevolution in the genes it controls. Our model, based on meiotic drive in mammals, but easily extended to other systems, would tend to facilitate population isolation by generating molecular incompatabilities. Circumstances can even be envisioned in which the process could provide intrinsic impetus to speciation.     

Isolation of Vibrio cholerae O1 from aquatic environments and foods in Pernambuco State, Brazil

Gastrointestinal symptoms and fecal frequency following ingestion of yogurt containing 15 g of galacto-oligosaccharides (GOS) per d were observed in 12 healthy volunteers. The effect of GOS on intestinal microflora was also studied in six volunteers. Defecation frequency increased during the administration period, but gastrointestinal symptoms, especially flatulence, also increased. The level of fecal bifidobacteria did not increase by the yogurt intake, but a significant increase was observed in the fecal bacteria growing on MRS media. The results indicate that dietary GOS increase gastrointestinal symptoms and fecal frequency in normal adults and have an effect on intestinal microecosystem.     

Variations in activity of the human natural anti-Gal antibody in young and elderly populations

BACKGROUND: Anti-Gal is a natural antibody which constitutes approximately 1% of circulating IgG in humans and which interacts specifically with the mammalian carbohydrate epitope Gal alpha 1-3Gal beta 1-4GlcNAc-R (termed the alpha-galactosyl epitope). The purpose of this study was to determine whether there are age-associated changes in the affinity of anti-Gal in elderly individuals. METHODS: The age-associated variations in affinity of anti-Gal were determined by the extent of this antibody binding to solid-phase alpha-galactosyl epitopes (mouse laminin) in ELISA, performed at various serum dilutions with serum samples from 140 elderly and 127 young individuals. The data were expressed as the mean of optical density (O.D.) values measured at serum dilutions of 1:40, 1:80, and 1:160, and correlated with the affinity of anti-Gal as measured in equilibrium dialysis. RESULTS: The proportion of individuals with low-affinity anti-Gal is sixfold higher in the elderly than in the young population. Whereas low-affinity binding of anti-Gal (mean O.D. value < or = 1.0) was observed in only 6% of the young population, as many as 35% of the elderly population displayed such low-affinity anti-Gal. Anti-Gal affinity in ELISA assay correlated with the affinity of this antibody as measured in equilibrium dialysis. CONCLUSION: The proportion of individuals with low affinity anti-Gal increases in the elderly population in comparison with the young population. The possible molecular mechanisms which may result in the age-associated decrease in the antibody affinity are discussed.     

Anti-pterins as tools to characterize the function of tetrahydrobiopterin in NO synthase

Nitric oxide synthases (NOS) are homodimeric enzymes that NADPH-dependently convert L-arginine to nitric oxide and L-citrulline. Interestingly, all NOS also require (6R)-5,6,7, 8-tetrahydro-L-biopterin (H4Bip) for maximal activity although the mechanism is not fully understood. Basal NOS activity, i.e. that in the absence of exogenous H4Bip, has been attributed to enzyme-associated H4Bip. To elucidate further H4Bip function in purified NOS, we developed two types of pterin-based NOS inhibitors, termed anti-pterins. In contrast to type II anti-pterins, type I anti-pterins specifically displaced enzyme-associated H4Bip and inhibited H4Bip-stimulated NOS activity in a fully competitive manner but, surprisingly, had no effect on basal NOS activity. Moreover, for a number of different NOS preparations basal activity (percent of Vmax) was frequently higher than the percentage of pterin saturation and was not affected by preincubation of enzyme with H4Bip. Thus, basal NOS activity appeared to be independent of enzyme-associated H4Bip. The lack of intrinsic 4a-pterincarbinolamine dehydratase activity argued against classical H4Bip redox cycling in NOS. Rather, H4Bip was required for both maximal activity and stability of NOS by binding to the oxygenase/dimerization domain and preventing monomerization and inactivation during L-arginine turnover. Since anti-pterins were also effective in intact cells, they may become useful in modulating states of pathologically high nitric oxide formation.