Vitamin D and physical performance in elderly subjects: the Pro.V.A study

Background

The role of Vitamin D in musculoskeletal functionality among elderly people is still controversial. We investigated the association between serum 25-hydroxyvitamin D (25OHD) levels and physical performance in older adults.

Methods

2694 community-dwelling elderly women and men from the Progetto Veneto Anziani (Pro.V.A.) were included. Physical performances were assessed by: tandem test, 5 timed chair stands (TCS), gait speed, 6-minute walking (6 mW) distance, handgrip strength, and quadriceps strength. For each test, separate general linear models and loess plots were obtained in both genders, in relation to serum 25OHD concentrations, controlling for several potential confounders.

Results

Linear associations with 25OHD levels were observed for TCS, gait speed, 6 mW test and handgrip strength, but not for tandem test and quadriceps strength. After adjusting for potential confounders, linear associations with 25OHD levels were still evident for the 6 mW distance in both genders (p = .0002 in women; <.0001 in men), for TCS in women (p = .004) and for gait speed (p = .0006) and handgrip strength (p = .03) in men. In loess analyses, performance in TCS in women, in gait speed and handgrip strength in men and in 6 mW in both genders, improved with increasing levels of 25OHD, with most of the improvements occurring for 25OHD levels from 20 to 100 nmol/L.

Conclusion

lower 25OHD levels are associated with a worse coordination and weaker strength (TCS) in women, a slower walking time and a lower upper limb strength in men, and a weaker aerobic capacity (6 mW) in both genders. For optimal physical performances, 25OHD concentrations of 100 nmol/L appear to be more advantageous in elderly men and women, and Vitamin D supplementation should be encouraged to maintain their 25OHD levels as high as this threshold.     

Molecular characterization of atypical Chlamydia and evidence of their dissemination in different European and Asian chicken flocks by specific real-time PCR

Chlamydia psittaci is a zoonotic pathogen associated primarily with avian chlamydiosis. New chlamydial agents with suspected zoonotic potential were recently detected from domestic poultry in Germany and France indicating that the spectrum of Chlamydiaceae encountered in birds is not confined to a single chlamydial species. For further characterization, a specific real-time PCR targeting the conserved 16S rRNA gene was developed and validated for a specific detection of these atypical Chlamydiaceae. In order to address the epidemiological importance of the new chlamydial agents and their distribution, Chlamydiaceae-positive chicken samples collected from flocks from five different countries were examined. The results confirmed that C.psittaci is not the predominant chlamydial species among chickens examined and suggested that the new chlamydial agents could putatively be widespread in poultry flocks (France, Greece, Croatia, Slovenia and China at least) justifying their systematic investigation when poultry samples are submitted to laboratories for avian chlamydiosis diagnosis. Besides, 16S rRNA-based dendrogram, including sequences from both isolates of the new chlamydial agents or positive samples as well as representative sequences from species belonging to the order Chlamydiales, showed the new chlamydial agents to form a distinct line of descent separated from those of other chlamydial species, but clearly grouped within the family Chlamydiaceae. Finally, the phylogenetic tree inferred from the multi-locus sequence typing based on four housekeeping fragments (gatA, gidA, enoA and hflX) and the ompA-based dendrogram showed an almost identical topology of the new chlamydial agents with that recovered by 16S rRNA-based dendrogram. Interestingly, partial ompA gene sequences displayed considerable diversity among isolates.     

DNA complexes with polycations useful for delivery of DNA into cells

Generation and physicochemical properties of complexes formed by high-molecular thymus DNA and plasmid DNA with synthetic polymers of (dimethyl amino)ethyl methacrylate, (diethyl amino)ethyl methacrylate, and poly(vinyl amine) were studied in solutions of different ionic strength using low-gradient viscometry, electrophoresis, circular dichroism, spectrophotometry, and dynamic light scattering. The complexes were tested for toxicity with T98G cell cultures. Condensation of DNA was shown to occur when the ratio of charged groups in the polycations and DNA exceeded unity. This condensation manifested itself as an increase in the optical density of DNA solutions. Condensation-associated changes in the dimensions of DNA molecules were determined, and phase diagrams of DNA-polycation systems were analyzed in the presence of NaCl. MTT analysis revealed no toxicity of these complexes.     

Effect of intestinal microflora on the pathogenesis of cholera intoxication

Germ-free minipigs, previously treated with bacteroids, develop cholinergic reaction after the intragastric administration of Vibrio cholerae exotoxin. The intensity of this reaction, disturbances in homeostasis, and the character of morphological changes depend on the dose of choleragen, the bacteroid strain, and the presence of the concomitant (Escherichia coli) and residual microflora in the intestine.     

The status of the lymphoid system under conditions of lung regeneration stimulation

In experiments on albino rats using cytochemical, autoradiographic, histological and biometrical methods of investigation the authors have shown the participation of the lymphoid system in the development of the compensatory hypertrophic rearrangement in the lung following left-sided pulmonectomy under conditions of regeneration stimulation by exposure to pyrimidine (potassium orotate) and purine (riboxin) derivatives. The dynamics of the regenerative process in the lung, its intensity and stage-by-stage character are clearly reflected in the enzymatic activity of circulating lymphocytes and in synthetic processes in the thymus and spleen.