Clinical Evaluation of Sodium Amylosulfate in Human Blood Cultures

Sodium amylosulfate was shown to be a useful anticoagulant additive for increased isolation of bacteria from clinical blood cultures.     

Characterization of zonal fractions of calf thymus DNA

DNA isolated from calf thymus nuclei is fractionated by zonal centrifugation into 40 sedimentation-rate classes and the reduced viscosity profile determined. This profile is divided into four fractions, I–IV, IV being the fastest sedimenting. The relative concentrations of repetitive DNA sequences in these is determined by hybridization on membrane filters and also hypochromicity by reannealing at 60 °. Repetitive sequences are found in all fractions, although they are slightly more abundant in the order III > II > I. Moreover, fractions I, II, III, act as good competitors in hybridization experiments with each other, implying that a high degree of complementarity exists between repetitive sequences in each of the fractions. Fraction IV had peculiar hydrodynamic properties which have provoked observations on DNA purification.     

Identification of physicochemical selective pressure on protein encoding nucleotide sequences

Background  

Statistical methods for identifying positively selected sites in protein coding regions are one of the most commonly used tools in evolutionary bioinformatics. However, they have been limited by not taking the physiochemical properties of amino acids into account.     

TREATMENT OF HYPERLIPEMIC DIABETIC PATIENTS—Effects of Dextro-Thyroxine Therapy

Serum low-density lipoproteins of 12 hyperlipemic diabetic patients were lowered, in some cases to normal values, by administration of dextro-thyroxine. Accompanying reductions in serum total cholesterol were largely reflected in the low-density lipoprotein fraction. By contrast, high-density lipoprotein cholesterol concentrations remained relatively unchanged. Diabetic control by insulin or oral hypoglycemic agents was not detectably altered by dextro-thyroxine therapy for periods of 8 to 46 weeks. Therefore, use of the drug for treatment of diabetic hyperlipemia would appear to merit further investigation.     

Effects of Long-Term Pioglitazone Treatment on Peripheral and Central Markers of Aging

Background

Thiazolidinediones (TZDs) activate peroxisome proliferator-activated receptor gamma (PPARγ) and are used clinically to help restore peripheral insulin sensitivity in Type 2 diabetes (T2DM). Interestingly, long-term treatment of mouse models of Alzheimer''s disease (AD) with TZDs also has been shown to reduce several well-established brain biomarkers of AD including inflammation, oxidative stress and Aβ accumulation. While TZD''s actions in AD models help to elucidate the mechanisms underlying their potentially beneficial effects in AD patients, little is known about the functional consequences of TZDs in animal models of normal aging. Because aging is a common risk factor for both AD and T2DM, we investigated whether the TZD, pioglitazone could alter brain aging under non-pathological conditions.

Methods and Findings

We used the F344 rat model of aging, and monitored behavioral, electrophysiological, and molecular variables to assess the effects of pioglitazone (PIO-Actos® a TZD) on several peripheral (blood and liver) and central (hippocampal) biomarkers of aging. Starting at 3 months or 17 months of age, male rats were treated for 4–5 months with either a control or a PIO-containing diet (final dose approximately 2.3 mg/kg body weight/day). A significant reduction in the Ca²⁺-dependent afterhyperpolarization was seen in the aged animals, with no significant change in long-term potentiation maintenance or learning and memory performance. Blood insulin levels were unchanged with age, but significantly reduced by PIO. Finally, a combination of microarray analyses on hippocampal tissue and serum-based multiplex cytokine assays revealed that age-dependent inflammatory increases were not reversed by PIO.

Conclusions

While current research efforts continue to identify the underlying processes responsible for the progressive decline in cognitive function seen during normal aging, available medical treatments are still very limited. Because TZDs have been shown to have benefits in age-related conditions such as T2DM and AD, our study was aimed at elucidating PIO''s potentially beneficial actions in normal aging. Using a clinically-relevant dose and delivery method, long-term PIO treatment was able to blunt several indices of aging but apparently affected neither age-related cognitive decline nor peripheral/central age-related increases in inflammatory signaling.     

Brain development, song learning and mate choice in birds: a review and experimental test of the "nutritional stress hypothesis"

The nutritional stress hypothesis explains how learned features of song, such as complexity and local dialect structure, can serve as indicators of male quality of interest to females in mate choice. The link between song and quality comes about because the brain structures underlying song learning largely develop during the first few months post-hatching. During this same period, songbirds are likely to be subject to nutritional and other stresses. Only individuals faring well in the face of stress are able to invest the resources in brain development necessary to optimize song learning. Learned features of song thus become reliable indicators of male quality, with reliability maintained by the developmental costs of song. We review the background and assumptions of the nutritional stress hypothesis, and present new experimental data demonstrating an effect of nestling nutrition on nestling growth, brain development, and song learning, providing support for a key prediction of the hypothesis.