Changes in the content and structure of the coenzyme A moiety in the liver of diabetic mice (db/db) administered a regimen of nicotinamide

Alterations in the content and structure of CoA moiety typical of hyperlipogenesis (a rise in total and free CoA levels, a drop in short-chained fatty acyl-CoA/CoA and long-chained fatty acyl-CoA/CoA ratios) were found in the liver of obese mice with non-insulin-dependent diabetes (db/db). The treatment of diabetic mice with nicotinamide, an antilipemic drug, was accompanied by a decrease in total and free CoA levels and a rise in short-chained fatty acyl-CoA content and short-chained fatty acyl-CoA/CoA and long-chained fatty acyl-CoA/CoA ratios, probably leading to the inhibition of the enzymes of primary lipogenesis steps. It is suggested that CoA moiety structure is essential as an integral index regulating the rate of fatty acid biosynthesis in diabetes mellitus.     

Sensitive control of heart rate in monkeys using burst stimulation of the vagus nerve

Burst vagus stimulation led to synchronization of the cardiac and vagal rhythms at certain frequency ranges. The increase of the number of impulses in a burst from 1 to 16 extended the range of synchronization and shifted it towards lower frequencies forming a total range of exact regulation of the heart rate within 85--40% of the initial rate. It was suggested that vagal effect consists of tonic and synchronizing components.     

Variability in several ecologic-physiologic traits of different populations of the Asiatic Arctic suslik Citellus parryi]

In several geographic populations of the Arctic ground squirrel C. parryi, studies have been made on changes in oxygen consumption during decrease of the ambient temperature from 25 to 3-4 degrees, thermal preference, hemoglobin content of the blood and composition of the adipose tissue (both brown and white, subcutaneous and visceral). Significant shifts of these indices were found. In animals from various parts of the species area, different sensitivity to cooling was found, as indicated by determinations of oxygen consumption at different temperatures and the prefered temperature: different hemoglobin content of the blood was also found together with differences in the level of two unsaturated fatty acids - the oleic and linoleic ones. Comparison of these data with similar results obtained on various populations of the Siberian ground squirrel C. undulatus revealed obvious differences between these close species with respect to the indices studied.     

An Efficient Method for Quantitative,Single-cell Analysis of Chromatin Modification and Nuclear Architecture in Whole-mount Ovules in Arabidopsis

In flowering plants, the somatic-to-reproductive cell fate transition is marked by the specification of spore mother cells (SMCs) in floral organs of the adult plant. The female SMC (megaspore mother cell, MMC) differentiates in the ovule primordium and undergoes meiosis. The selected haploid megaspore then undergoes mitosis to form the multicellular female gametophyte, which will give rise to the gametes, the egg cell and central cell, together with accessory cells. The limited accessibility of the MMC, meiocyte and female gametophyte inside the ovule is technically challenging for cytological and cytogenetic analyses at single cell level. Particularly, direct or indirect immunodetection of cellular or nuclear epitopes is impaired by poor penetration of the reagents inside the plant cell and single-cell imaging is demised by the lack of optical clarity in whole-mount tissues.Thus, we developed an efficient method to analyze the nuclear organization and chromatin modification at high resolution of single cell in whole-mount embedded Arabidopsis ovules. It is based on dissection and embedding of fixed ovules in a thin layer of acrylamide gel on a microscopic slide. The embedded ovules are subjected to chemical and enzymatic treatments aiming at improving tissue clarity and permeability to the immunostaining reagents. Those treatments preserve cellular and chromatin organization, DNA and protein epitopes. The samples can be used for different downstream cytological analyses, including chromatin immunostaining, fluorescence in situ hybridization (FISH), and DNA staining for heterochromatin analysis. Confocal laser scanning microscopy (CLSM) imaging, with high resolution, followed by 3D reconstruction allows for quantitative measurements at single-cell resolution.     

Controlled atrial fibrillation and a possible mechanism of its genesis

In experiments on cats a single premature beat or vagal stimulation shortened the effective refractory period without any spontaneous heart rate disturbances, while the combined action of these factors always led to paroxysmal tachycardia or atrial fibrillation. It is suggested that contracting myocardium possesses a covert ability for self-excitation revealed only in critical shortening of the action potential. Since the excitation occurring in such conditions is also a premature beat, the fibrillation process becomes self-maintaining.     

Cutaneous and Mucosal Phaeohyphomycosis Caused by Exophiala spinifera in a Pregnant Patient: Case Report and Literature Review

We report a case of mucocutaneous phaeohyphomycosis caused by Exophiala spinifera. Crusty plaques and nodules were major clinical features. Histological examination revealed brown yeast-like cells and hyphae. Mycological and molecular data identified E. spinifera as etiologic agent. Oral itraconazole was effective, which was in accordance with the results of in vitro susceptibility testing. We speculated that her pregnancy may play a role of risk factor in the infection by E. spinifera.