Glucosylation of Teichoic Acid: Solubilization and Partial Characterization of the Uridine Diphosphoglucose:Polyglycerolteichoic Acid Glucosyl Transferase from Membranes of Bacillus subtilis

Polyglycerolteichoic acid:glucosyl transferase (TAG transferase), one of the three enzymes involved in the pathway leading to the glucosylation of teichoic acid in Bacillus subtilis 168, was investigated. During the early stages of the growth of B. subtilis, TAG transferase is predominantly a soluble enzyme found in the cytoplasm. As growth proceeds, the amount of soluble enzyme decreases and the proportion of insoluble, membrane-bound TAG transferase increases, reaching a maximal value at the close of the logarithmic phase. Data are presented which suggest that these are two forms of the same enzyme, or have some common component. The effects of chaotropic agents, such as sodium trichloroacetate and sodium perchlorate, on the cytoplasmic membrane were also studied. These data show that such compounds can effectively remove the TAG transferase from the membrane in a water-soluble form. A study of some of the physical properties of this solubilized enzyme suggests that there is little difference between the two forms of the enzyme. Experiments are described which indicate that the glucosyl transfer by both the membrane-bound and soluble enzymes is not mediated by lipids.     

Response of no-till and conventionally planted grain sorghum to weed control method and row spacing

Grain sorghum can substitute for corn as a full season crop and replace soybeans in double cropping systems with wheat in the southeastern United States. Relatively few studies have been conducted to measure the response of grain sorghum to tillage, weed control method, and row spacing. These experiments were designed to determine the effects of weed control method and row spacing on no-till planted grain sorghum (Sorghum bicolor L. Moench G1516-BR) after wheat (Triticum aestivum L. Coker 68–15) and crimson clover (Trifolium incarnatum L. Bigbee) grown for winter forage in comparison to sorghum planted on a conventionally prepared seedbed. The experiment included 45, 60, and 90 cm row spacings and three weed control regimes: none, mechanical, and chemical. Grain sorghum planted no-till in crimson clover or wheat sod yielded considerably more grain than conventionally planted sorghum. Grain sorghum produced significantly higher yields in 45-cm rows than in 60-and 90-cm row spacings with all three planting methods. Effects of chemical weed control on weed population with all tillage methods and on grain yield with conventional tillage were significant. There were no significant differences in grain protein content due to row spacing or weed control method.     

Psychosocial perception of adults with onychomycosis: a blinded,controlled comparison of 1,017 adult Hong Kong residents with or without onychomycosis

Background

A survey was conducted amongst 1,017 Hong Kong residents ages 18 and over to determine their knowledge of fungal nail infections (onychomycosis) and the psychosocial impact of the disease on the relationships, social lives and careers of sufferers.

Methods

The Fungal Nail Perception Survey was conducted by email and online between May 29th and June 10th, 2013. Participants were shown three photographs of people with and without onychomycosis of the toenails. Respondents were asked ten questions (repeated for each picture) to ascertain their perceptions of the people in the pictures. Questions were related to perceptions around the ability of sufferers and non-sufferers to form relationships with others, social activities of sufferers and non-sufferers, perceptions of the effect of the disease on the potential for career success, and awareness of fungal nail disease and health. The sub-population who themselves suffered from onychomycosis were asked about self-perception as well as their perception of others with onychomycosis.

Results

Compared with non-sufferers, survey respondents perceived those with onychomycosis as less likely to be able to form good relationships. They also indicated that they would be more likely to exclude sufferers than non-sufferers from social activities and that they would be more likely to feel uncomfortable when sitting or standing beside an infected person than beside an uninfected person. Respondents perceived people with onychomycosis to be less able to perform well in their chosen career than with someone without onychomycosis. Interestingly, those respondents who themselves were infected felt socially excluded, upset and embarrassed by their infection.

Conclusions

Onychomycosis may lead to stigmatization and social exclusion. Misconceptions of onychomycosis are high and education about the disease needs to be improved. Early recognition and treatment of the disease is essential to avoid complications and improve treatment outcomes, which would lead to reduced psychosocial impact on those with fungal nail infections.

     

Recurrence of Early Stage Colon Cancer Predicted by Expression Pattern of Circulating microRNAs

Systemic treatment of patients with early-stage cancers attempts to eradicate occult metastatic disease to prevent recurrence and increased morbidity. However, prediction of recurrence from an analysis of the primary tumor is limited because disseminated cancer cells only represent a small subset of the primary lesion. Here we analyze the expression of circulating microRNAs (miRs) in serum obtained pre-surgically from patients with early stage colorectal cancers. Groups of five patients with and without disease recurrence were used to identify an informative panel of circulating miRs using quantitative PCR of genome-wide miR expression as well as a set of published candidate miRs. A panel of six informative miRs (miR-15a, mir-103, miR-148a, miR-320a, miR-451, miR-596) was derived from this analysis and evaluated in a separate validation set of thirty patients. Hierarchical clustering of the expression levels of these six circulating miRs and Kaplan-Meier analysis showed that the risk of disease recurrence of early stage colon cancer can be predicted by this panel of miRs that are measurable in the circulation at the time of diagnosis (P = 0.0026; Hazard Ratio 5.4; 95% CI of 1.9 to 15).     

Genome Duplications and Other Features in 12 Mb of DNA Sequence from Human Chromosome 16p and 16q

Several publicly funded large-scale sequencing efforts have been initiated with the goal of completing the first reference human genome sequence by the year 2005. Here we present the results of analysis of 11.8 Mb of genomic sequence from chromosome 16. The apparent gene density varies throughout the region, but the number of genes predicted (84) suggests that this is a gene-poor region. This result may also suggest that the total number of human genes is likely to be at the lower end of published estimates. One of the most interesting aspects of this region of the genome is the presence of highly homologous, recently duplicated tracts of sequence distributed throughout the p-arm. Such duplications have implications for mapping and gene analysis as well as the predisposition to recurrent chromosomal structural rearrangements associated with genetic disease.     

Combined monte carlo and molecular dynamics simulation of fully hydrated dioleyl and palmitoyl-oleyl phosphatidylcholine lipid bilayers

We have applied a new equilibration procedure for the atomic level simulation of a hydrated lipid bilayer to hydrated bilayers of dioleyl-phosphatidylcholine (DOPC) and palmitoyl-oleyl phosphatidylcholine (POPC). The procedure consists of alternating molecular dynamics trajectory calculations in a constant surface tension and temperature ensemble with configurational bias Monte Carlo moves to different regions of the configuration space of the bilayer in a constant volume and temperature ensemble. The procedure is applied to bilayers of 128 molecules of POPC with 4628 water molecules, and 128 molecules of DOPC with 4825 water molecules. Progress toward equilibration is almost three times as fast in central processing unit (CPU) time compared with a purely molecular dynamics (MD) simulation. Equilibration is complete, as judged by the lack of energy drift in 200-ps runs of continuous MD. After the equilibrium state was reached, as determined by agreement between the simulation volume per lipid molecule with experiment, continuous MD was run in an ensemble in which the lateral area was restrained to fluctuate about a mean value and a pressure of 1 atm applied normal to the bilayer surface. Three separate continuous MD runs, 200 ps in duration each, separated by 10,000 CBMC steps, were carried out for each system. Properties of the systems were calculated and averaged over the three separate runs. Results of the simulations are presented and compared with experimental data and with other recent simulations of POPC and DOPC. Analysis of the hydration environment in the headgroups supports a mechanism by which unsaturation contributes to reduced transition temperatures. In this view, the relatively horizontal orientation of the unsaturated bond increases the area per lipid, resulting in increased water penetration between the headgroups. As a result the headgroup-headgroup interactions are attenuated and shielded, and this contributes to the lowered transition temperature.     

17β-Estradiol responsiveness of MCF-7 laboratory strains is dependent on an autocrine signal activating the IGF type I receptor

Background  

Human MCF-7 cells have been studied extensively as a model for breast cancer cell growth. Many reports have established that serum-starved MCF-7 cells can be induced to proliferate upon the sole addition of 17β-estradiol (E2). However, the extent of the mitogenic response to E2 varies in different MCF-7 strains and may even be absent. In this study we compared the E2-sensitivity of three MCF-7 laboratory strains.