Alfalfa-derived HSP70 administered intranasally improves insulin sensitivity in mice

Heat shock protein (HSP) 70 is an abundant cytosolic chaperone protein that is deficient in insulin-sensitive tissues in diabetes and unhealthy aging, and is considered a longevity target. It is also protective in neurological disease models. Using HSP70 purified from alfalfa and administered as an intranasal solution, we tested in whether the administration of Hsp70 to diet-induced diabetic mice would improve insulin sensitivity. Both the 10 and 40 μg given three times per week for 26 days significantly improved the response to insulin. The HSP70 was found to pass into the olfactory bulbs within 4–6 hours of a single dose. These results suggest that a relatively inexpensive, plentiful source of HSP70 administered in a simple, non-invasive manner, has therapeutic potential in diabetes.     

Molecular evolution of mitochondrial 12S RNA and cytochrome b sequences in the pantherine lineage of Felidae

DNA sequence comparisons of two mitochondrial DNA genes were used to infer phylogenetic relationships among 17 Felidae species, notably 15 in the previously described pantherine lineage. The polymerase chain reaction (PCR) was used to generate sequences of 358 base pairs of the mitochondrial 12S RNA gene and 289 base pairs of the cytochrome b protein coding gene. DNA sequences were compared within and between 17 felid and five nonfelid carnivore species. Evolutionary trees were constructed using phenetic, cladistic, and maximum likelihood algorithms. The combined results suggested several phylogenetic relationships including (1) the recognition of a recently evolved monophyletic genus Panthera consisting of Panthera leo, P. pardus, P. onca, P. uncia, P. tigris, and Neofelis nebulosa; (2) the recent common ancestry of Acinonyx jubatus, the African cheetah, and Puma concolor, the American puma; and (3) two golden cat species, Profelis temmincki and Profelis aurata, are not sister species, and the latter is strongly associated with Caracal caracal. These data add to the growing database of vertebrate mtDNA sequences and, given the relatively recent divergence among the felids represented here (1-10 Myr), allow 12S and cytochrome b sequence evolution to be addressed over a time scale different from those addressed in most work on vertebrate mtDNA.      

Roles of nifF and nifJ gene products in electron transport to nitrogenase in Klebsiella pneumoniae.

Crude extracts of the wild-type Klebsiella pneumoniae reduced C2H2 with either pyruvate or formate as reductant (specific activity, 3 nmol min-1 mg of protein-1), whereas crude extracts of nifF mutant were almost inactive (specific activity, 0.05). However, activity in the latter extracts was stimulated by adding Azotobacter chroococcum flavodoxin (specific activity, 10). Thus, nifF mutants may lack an electron transport factor. Crude extracts of nifJ mutants had about 20% of the wild-type level of active MoFe protein, and thus nifJ has a presumptive role in maintaining active MoFe protein. Studies on pyruvate or formate as reductants for nitrogenase in extracts of the nifJ mutants suggest in addition a role in electron input to nitrogenase for the following reasons. (i) Nitrogenase activity with these reductants was very low (specific activity, 0.06) and was not stimulated by extra MoFe protein or the flavodoxin. (ii) Activity was increased by adding a crude extract of a mutant lacking the structural nif genes (specific activity, 1) or a crude extract of the nifF mutant (specific activity, 4).     

Breeding seasonality among long-tailed macaques,Macaca fascicularis,in Peninsular Malaysia

The females among more than 7000 long-tailed macaques, Macaca fascicularis,that had recently been trapped for biomedical research were examined for pregnancy. The animals were taken from the wild in the north of Peninsular Malaysia during the period 1978 to 1979 and in the south from 1978 to 1982. Both samples showed some pregnancies in all months of the year and a peak during the months of May to July. Additional peaks in other months in some years showed that, while the midyear pregnancy peak was significant, it was not as marked a phenomenon as is the breeding peak in many other species. This might be due to the complexity and unpredictability of both the climate and the macaques’ food supply in Peninsular Malaysia. The additional peaks also illustrated the pitfalls of generalizing about breeding seasonality on the basis of small samples.     

GUS fusions: beta-glucuronidase as a sensitive and versatile gene fusion marker in higher plants.

We have used the Escherichia coli beta-glucuronidase gene (GUS) as a gene fusion marker for analysis of gene expression in transformed plants. Higher plants tested lack intrinsic beta-glucuronidase activity, thus enhancing the sensitivity with which measurements can be made. We have constructed gene fusions using the cauliflower mosaic virus (CaMV) 35S promoter or the promoter from a gene encoding the small subunit of ribulose bisphosphate carboxylase (rbcS) to direct the expression of beta-glucuronidase in transformed plants. Expression of GUS can be measured accurately using fluorometric assays of very small amounts of transformed plant tissue. Plants expressing GUS are normal, healthy and fertile. GUS is very stable, and tissue extracts continue to show high levels of GUS activity after prolonged storage. Histochemical analysis has been used to demonstrate the localization of gene activity in cells and tissues of transformed plants.     

Ventricular arrhythmias.

Sudden cardiac death claims thousands of Canadians annually. Ventricular tachycardia and fibrillation account for up to 85% of these deaths. Identifying the patients at risk remains a major challenge. Those who have recurrent ventricular tachycardia or have been resuscitated from ventricular fibrillation are generally considered to be at highest risk. Although ventricular premature beats in the absence of previous ventricular tachycardia or fibrillation are not helpful in identifying such patients in most cases, they can indicate increased risk for sudden cardiac death in the presence of a structural cardiac abnormality, particularly recent myocardial infarction; however, the need for treatment in such cases is speculative and is being investigated. Treatment is mandatory for survivors of an episode of ventricular fibrillation and those with recurrent sustained ventricular tachycardia or torsade de pointes ventricular tachycardia. The approach to management is either invasive or noninvasive. Selection of an antiarrhythmic agent is facilitated by knowledge of some basic electrophysiologic features of the heart and of the classification of antiarrhythmic drugs. However, drug therapy has to be individualized on the basis of efficacy, left ventricular function and adverse effects or potential adverse effects of the drug. Amiodarone therapy or nonpharmacologic therapy should be considered if a suitable antiarrhythmic agent cannot be found.     

Are indices of free radical damage related to exercise intensity

The possibility that plasma levels of malonaldehyde (MDA) are altered by exercise has been examined. The presence of MDA has been recognized to reflect peroxidation of lipids resulting from reactions with free radicals. Maximal exercise, eliciting 100% of maximal oxygen consumption (VO2max) resulted in a 26% increase in plasma MDA (P less than 0.005). Short periods of intermittent exercise, the intensity of which was varied, indicated a correlation between lactate and MDA (r2 = 0.51) (p less than 0.001). Blood lactate concentrations increased throughout this exercise regimen. A significant decrease (10.3%) in plasma MDA occurred at 40% VO2max. At 70% VO2max plasma MDA was still below resting values, however the trend to an increase in MDA with exercise intensity was evident. At exhaustion, plasma MDA and lactate were significantly greater than at rest. These results suggest, that exhaustive maximal exercise induces free radical generation while short periods of submaximal exercise (i.e. less than 70% VO2max) may inhibit it and lipid peroxidation.     

The scientific impact of the Structural Genomics Consortium: a protein family and ligand-centered approach to medically-relevant human proteins

As many of the structural genomics centers have ended their first phase of operation, it is a good point to evaluate the scientific impact of this endeavour. The Structural Genomics Consortium (SGC), operating from three centers across the Atlantic, investigates human proteins involved in disease processes and proteins from Plasmodium falciparum and related organisms. We present here some of the scientific output of the Oxford node of the SGC, where the target areas include protein kinases, phosphatases, oxidoreductases and other metabolic enzymes, as well as signal transduction proteins. The SGC has aimed to achieve extensive coverage of human gene families with a focus on protein–ligand interactions. The methods employed for effective protein expression, crystallization and structure determination by X-ray crystallography are summarized. In addition to the cumulative impact of accelerated delivery of protein structures, we demonstrate how family coverage, generic screening methodology, and the availability of abundant purified protein samples, allow a level of discovery that is difficult to achieve otherwise. The contribution of NMR to structure determination and protein characterization is discussed. To make this information available to a wide scientific audience, a new tool for disseminating annotated structural information was created that also represents an interactive platform allowing for a continuous update of the annotation by the scientific community.