9β Polymorphism of the Glucocorticoid Receptor Gene Appears to Have Limited Impact in Patients with Addison’s Disease

Background

Addison’s disease (AD) has been associated with an increased risk of cardiovascular disease. Glucocorticoid receptor polymorphisms that alter glucocorticoid sensitivity may influence metabolic and cardiovascular risk factors in patients with AD. The 9β polymorphism of the glucocorticoid receptor gene is associated with relative glucocorticoid resistance and has been reported to increase the risk of myocardial infarction in the elderly. We explored the impact of this polymorphism in patients with AD.

Materials and Methods

147 patients with AD and 147 age, gender and ethnicity matched healthy controls were recruited. Blood was taken in a non-fasted state for plasma lipid determination, measurement of cardiovascular risk factors and DNA extraction.

Results

Genotype data for the 9β polymorphism was available for 139 patients and 146 controls. AD patients had a more atherogenic lipid profile characterized by an increase in the prevalence of small dense LDL (p = 0.003), increased triglycerides (p = 0.002), reduced HDLC (p<0.001) an elevated highly sensitive C-reactive protein (p = 0.01), compared with controls. The 9β polymorphism (at least one G allele) was found in 28% of patients and controls respectively. After adjusting for age, gender, ethnicity, BMI and hydrocortisone dose per metre square of body surface area in patients, there were no significant metabolic associations with this polymorphism and hydrocortisone doses were not higher in patients with the polymorphism.

Conclusions

This study did not identify any associations between the 9β polymorphism and cardiovascular risk factors or hydrocortisone dose and determination of this polymorphism is therefore unlikely to be of clinical benefit in the management of patients with AD.     

Lactobacillus plantarum 24, Isolated From the Marula Fruit (Sclerocarya birrea), has Probiotic Properties and Harbors Genes Encoding the Production of Three Bacteriocins

Lactobacillus plantarum 24, isolated from marula fruit grows at pH 4.0 and tolerates acid levels and bile concentrations normally present in the human gastro-intestinal tract. Wistar rats that have been administered L. plantarum 24 showed no signs of discomfort or abnormal behavior. Tissue samples from the liver, spleen and intestine appeared normal. Furthermore, strain 24 harbors the genes encoding plantaricins A, F, and NC8α, a gene encoding immunity to plantaricin, and an ABC transporter similar in sequence to that reported for plantaricin G. At least one antimicrobial peptide within the size range of plantaricins A, F, and NC8α has been detected on a tricine-SDS–PAGE gel. Little is known about the microbial population in marula. This is the first report of a L. plantarum strain from marula fruit with bacteriocin genes and probiotic properties.     

Feasible,Efficient and Necessary,without Exception – Working with Sex Workers Interrupts HIV/STI Transmission and Brings Treatment to Many in Need

ConclusionDecades of empirical evidence, extended by analyses in this collection, argue that protecting sex work is, without exception, feasible and necessary for controlling HIV/STI epidemics. In addition, the disproportionate burden of HIV borne by sex workers calls for facilitated access to ART, care and support. The imperative for Africa is rapid scale-up of targeted prevention and treatment, facilitated by policies and action to improve conditions where sex work takes place. The opportunity is a wealth of accumulated experience working with sex workers in diverse settings, which can be tapped to make up for lost time. Elsewhere, even in countries with strong interventions and services for sex workers, an emerging challenge is to find ways to sustain them in the face of declining global resources.     

Seasonal analysis of the tropane alkaloid ecgonine methyl ester and the occurrence of other highly-valued tropanes in the South African <Emphasis Type="Italic">Erythroxylum</Emphasis> trees

The coca family (Erythroxylaceae) consists of trees and shrubs sub-divided into four genera: Aneulophus, Nectaropetalum, Pinacopodium, and Erythroxylum, which include species with highly valuable medicinal compounds. E. delagoense, E. emarginatum, and E. pictum are endemic to southern Africa and have great pharmaceutical potential based on their traditional uses. Previous studies have shown certain inconsistencies in terms of the presence or absence of tropane alkaloids in these species, resulting in a need for further research and clarification. Therefore, the aim of this study was to determine the seasonal variation of the immediate biosynthetic precursor of cocaine, the tropane alkaloid, ecgonine methyl ester in the three South African Erythroxylum species by means of gas chromatography–mass spectrometry, as well as to conduct a phytochemical screening for observing the presence of other potential compounds and tropane alkaloids. We found significant differences in tropane concentrations from the seasonal variation study, explaining the discrepancies in previous reports on its presence/absence in these species. Furthermore, we report for the first time on the occurrence of selected highly valuable tropane alkaloids in E. emarginatum currently used in ‘blockbuster medicine’.     

The presence of <Emphasis Type="Italic">Tetranychus urticae</Emphasis> (Acari: Tetranychidae) and its predators on plants in the ground cover in commercially treated vineyards

The presence of Tetranychus urticae and its predators on plants in the ground cover in commercially treated vineyards in the Hex River Valley, Western Cape Province, South Africa was investigated. Six Barlinka and six Dauphine vineyards were surveyed. Leaf samples from the plants on the vineyard floor were taken at monthly intervals and microscopically examined for spider mites and their predators. The coverage of the plants was determined using a co-ordinate sampling system. A wide variety of plant species was found on the vineyard floor. Most of the spider mites found on these plants were T. urticae. The phytoseiid mites on the plants were Euseius rubicolus, Neoseiulus californicus and an undescribed Typhlodromus species. The presence of these plants made it possible for T. urticae and phytoseiid mites to occur throughout the year, with a similar pattern in their seasonal activity on the vineyard floor and the vine leaves.     

Adhesion of the probiotic strains <Emphasis Type="Italic">Enterococcus mundtii</Emphasis> ST4SA and <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> 423 to Caco-2 cells under conditions simulating the intestinal tract,and in the presence of antibiotics and anti-inflammatory medicaments

Adhesion of Enterococcus mundtii ST4SA and Lactobacillus plantarum 423 to Caco-2 (human carcinoma epithelial) cells was visualized by fluorescent staining. Both strains showed good adhesion compared to L. casei MB1, L. casei Shirota, L. johnsonii La1 and L. rhamnosus GG. No correlation was found between hydrophobicity, aggregation and adhesion to Caco-2 cells. Presence of antibiotics and anti-inflammatory medicaments reduced adhesion of bacterial strains to Caco-2 cells. Proteins sensitive to pepsin, trypsin and pronase are involved in the adhesion of E. mundtii ST4SA and L. plantarum 423 to Caco-2 cells. Adhesion of Listeria monocytogenes ScottA to Caco-2 cells was not prevented by E. mundtii ST4SA and L. plantarum 423. Cell-free culture supernatants of strains ST4SA and 423, containing the antimicrobial peptides plantaricin 423 and peptide ST4SA, prevented the invasion of L. monocytogenes ScottA into Caco-2 cells.     

Factors Associated with Variations in Population HIV Prevalence across West Africa: Findings from an Ecological Analysis

Background

Population HIV prevalence across West Africa varies substantially. We assess the national epidemiological and behavioural factors associated with this.

Methods

National, urban and rural data on HIV prevalence, the percentage of younger (15–24) and older (25–49) women and men reporting multiple (2+) partners in the past year, HIV prevalence among female sex workers (FSWs), men who have bought sex in the past year (clients), and ART coverage, were compiled for 13 countries. An Ecological analysis using linear regression assessed which factors are associated with national variations in population female and male HIV prevalence, and with each other.

Findings

National population HIV prevalence varies between 0 4–2 9% for men and 0 4–5.6% for women. ART coverage ranges from 6–23%. National variations in HIV prevalence are not shown to be associated with variations in HIV prevalence among FSWs or clients. Instead they are associated with variations in the percentage of younger and older males and females reporting multiple partners. HIV prevalence is weakly negatively associated with ART coverage, implying it is not increased survival that is the cause of variations in HIV prevalence. FSWs and younger female HIV prevalence are associated with client population sizes, especially older men. Younger female HIV prevalence is strongly associated with older male and female HIV prevalence.

Interpretation

In West Africa, population HIV prevalence is not significantly higher in countries with high FSW HIV prevalence. Our analysis suggests, higher prevalence occurs where more men buy sex, and where a higher percentage of younger women, and older men and women have multiple partnerships. If a sexual network between clients and young females exists, clients may potentially bridge infection to younger females. HIV prevention should focus both on commercial sex and transmission between clients and younger females with multiple partners.     

Resource availability and disturbance shape maximum tree height across the Amazon

Tall trees are key drivers of ecosystem processes in tropical forest, but the controls on the distribution of the very tallest trees remain poorly understood. The recent discovery of grove of giant trees over 80 meters tall in the Amazon forest requires a reevaluation of current thinking. We used high‐resolution airborne laser surveys to measure canopy height across 282,750 ha of old‐growth and second‐growth forests randomly sampling the entire Brazilian Amazon. We investigated how resources and disturbances shape the maximum height distribution across the Brazilian Amazon through the relations between the occurrence of giant trees and environmental factors. Common drivers of height development are fundamentally different from those influencing the occurrence of giant trees. We found that changes in wind and light availability drive giant tree distribution as much as precipitation and temperature, together shaping the forest structure of the Brazilian Amazon. The location of giant trees should be carefully considered by policymakers when identifying important hot spots for the conservation of biodiversity in the Amazon.