Poly-γ-d-Glutamic Acid Capsule Interferes with Lytic Infection of Bacillus anthracis by B. anthracis-Specific Bacteriophages

The poly-γ-d-glutamic acid capsule of Bacillus anthracis is a barrier to infection by B. anthracis-specific bacteriophages. Capsule expression was found to completely inhibit lytic infection by γ phage, an observation supported by the demonstration that this phage does not elaborate a hydrolase that would facilitate penetration through the protective capsule outer layer.     

No sitting on the fence: protecting wetlands from feral pig damage by exclusion fences requires effective fence maintenance

Feral pigs damage the significant ecological and cultural values of tropical Australian wetlands. Control measures such as culling, baiting, and trapping can reduce overall pig populations, but do not eliminate the substantial physical damage to wetlands that can occur from just a few individuals. Exclusion fences have been adopted as a potential technique to prevent damage to selected wetlands. To test the effectiveness of exclusion fences we measured the physical damage caused by pigs to multiple wetlands in the Archer River catchment of tropical northern Australia. Wetlands were fenced using a typical cattle exclusion fence, a specific pig exclusion fence or had no fence. Initial analyses of these fence treatments showed no significant difference in the intensity of physical pig damage to exposed wetland sediments and fringing vegetation. However, several of the pig exclusion fences were found to have been compromised. Reanalysis indicated wetlands with functioning pig exclusion fences had no physical pig damage and this was significantly less damage than in all other treatments. In contrast, wetlands with compromised pig exclusion fences had damage that was statistically equivalent to sites without fences or with cattle exclusion fences, but in individual cases had the worst damage recorded in any of the treatments. Compromised pig exclusion fencing of wetlands can thus be worse than having no fencing at all. This suggests that the successful prevention of pig damage to wetlands by exclusion fences requires ongoing and effective fence monitoring and maintenance regimes.

     

Most germ-line mutations in the nevoid basal cell carcinoma syndrome lead to a premature termination of the PATCHED protein, and no genotype-phenotype correlations are evident.

The human homologue of the Drosophila segment polarity gene patched is implicated in the development of nevoid basal cell carcinoma syndrome (NBCCS) and in the genesis of sporadic basal cell carcinomas. In order to examine the phenotypic variability in NBCCS and to highlight functionally important domains of the PTCH protein, we have now screened 71 unrelated NBCCS individuals for mutations in the PTCH exons. We identified 28 mutations that are distributed throughout the entire gene, and most (86%) cause protein truncation. As part of this analysis, we demonstrate that failure of one NBCCS family to show clear linkage to chromosome 9q22.3-31 is most likely due to germinal mosaicism. We have identified three families bearing identical mutations with variable phenotypes, suggesting phenotypic variability in NBCCS is a complex genetic event. No phenotype genotype correlation between the position of truncation mutations and major clinical features was evident. Two missense mutations have been identified, and their location within transmembrane domains supports the notion that PTCH may have a transport function. The preponderance of truncation mutants in the germ line of NBCCS patients suggests that the developmental defects associated with the disorder are most likely due to haploinsufficiency.     

Prevention of Postoperative Leg Vein Thrombosis by Electrical Muscle Stimulation. An Evaluation with 125I-Labelled Fibrinogen

In a prospective trial of preventing deep vein thrombosis electrical stimulation of the calf muscles of one leg was used in 110 patients undergoing major surgery. Deep vein thrombosis was detected by means of the ¹²⁵I-fibrinogen uptake test in nine of the stimulated legs and in 23 of the unstimulated legs. It is suggested that this technique, which is both simple and effective, should be used on all patients undergoing major surgery.     

Peripheral QCT sector analysis reveals early exercise-induced increases in tibial bone mineral density

Objectives: The purpose of this controlled trial was to determine whether subtle changes in mineralization and geometry of the tibia were evident following short term exercise interventions. Methods: Fifty-seven female volunteers (age 20.1?1.6) were randomized to one of four, 13-week training groups: sedentary control, resistance training, aerobic training, or combined aerobic-resistance. A pQCT image analysis software was developed and used to analyze images taken at sites 4%, 38% and 66% from the distal tibia at baseline and at completion of training. Parameters of bone mineral density, geometry and strength were determined for the entire scan cross-section and for each of six 60(o) polar sectors. Repeated-measures ANOVA and Fisher's LSD post hoc tests analyzed the effects of training over time. Results: Trabecular density (TrDn) at the 4% site increased from 279.8?37.1 to 283.1?36.0 mg/cm(3) in the aerobic group, and from 285.1?24.6 to 287.5?22.9 mg/cm(3) in the combined group over the study period (P≤0.001). Regional sector analyses revealed that impact exercises resulted in localized changes to the medial aspect of the tibia. Small increases in total bone area were observed in the diaphysis (38% site) (P<0.05). Conclusions: Subtle, regional increases in trabecular density may be an early measurable manifestation of bone quality changes.