Detection of the measles virus genome in the peripheral blood lymphocytes of patients with chronic and acute glomerulonephritis]

The presence of the measles (rubeola) virus genome was searched for in the lymphocytes from the peripheral blood of patients suffering from the acute (16 persons) or chronic (164 persons) glomerulonephritis. Dot hybridization technique with the plasmid borne probes to the measles viral genes NP, P and H have been used for the search. The measles viral genome has been detected in 58% of lymphocytes from the patients with the chronic glomerulonephritis and in 50% of lymphocytes from the patients suffering from the acute form of the disease. The genome was not found in the material from the control group including donors and traumatology ward patients. 25 samples of lymphocytes from the patients with the chronic glomerulonephritis contained the RNA that was not hybridizable with the viral genes probes by dot hybridization technique, thus containing no genes homologous to parotitis viral genes. The average titer of anti-measles antibodies in the serum from patients with chronic glomerulonephritis the lymphocytes of which contained the measles viral genome was 1:304, while it was 1:154 for patients with the negative probes. The average anti-measles antibodies titers are the same (1:166 and 1:142) for analogical groups of patients with acute form of disease.     

黑线毛足鼠年龄和种群密度与肝毛细线虫感染率的关系

2004—2005年,在内蒙古锡林郭勒盟阿巴嘎旗和东乌珠穆沁旗研究了肝毛细线虫病对黑线毛足鼠种群感染情况,分析肝毛细线虫对黑线毛足鼠的感染率与鼠体年龄以及种群密度的关系。结果表明,黑线毛足鼠达到一定的年龄(或体质量)才可感染肝毛细线虫病,最低感染个体体质量为14.6g。肝毛细线虫对低龄鼠的感染检出率比较低,而对成体鼠感染检出率较高,其感染率和感染度均随着个体年龄的增长而增高(感染率与年龄:r=0.97,P<0.05;感染度与年龄:r=0.93,P<0.05)。此外,黑线毛足鼠体质量与肝毛细线虫感染率和感染度也存在显著的相关关系(感染率与体质量:r=0.99,P<0.05;感染度与体质量:r=0.95,P<0.05),黑线毛足鼠的种群密度则对肝毛细线虫的感染率(r=0.27,P>0.05)和平均感染度(r=0.41,P>0.05)没有明显的影响,其感染率可能与地区不同有关。     

Isolation and physico-chemical properties of homogenous nuclease from Serratia marcescens

A simplified procedure for purification of nuclease from Serratia marcescens, including chromatography on DEAE- and phosphocellulose in a stationary regime has been developed. The method described results in a physically homogenous enzyme, which does not contain phosphatase, phosphodiesterase or proteinase admixtures. The molecular weight of the enzyme as determined by polyacrylamide gel electrophoresis is 33 000 +/- 10%. p-Chloromercurybenzoate (10(-2) M) completely inactivates the enzyme, while beta-mercaptoethanol (0,64 M) in the presence of 2 M urea causes only partial inactivation of the enzyme. Urea (4 or 7 M), when added to the reaction mixture, increases the enzyme activity 2,2-, 1,7- and 1,4-fold as compared to native, denaturated DNA and RNA, respectively.     

Molecular evolution of cytochrome c oxidase: rate variation among subunit VIa isoforms

Cytochrome c oxidase (COX) consists of 13 subunits, 3 encoded in the mitochondrial genome and 10 in the nucleus. Little is known of the role of the nuclear-encoded subunits, some of which exhibit tissue-specific isoforms. Subunit VIa is unique in having tissue-specific isoforms in all mammalian species examined. We examined relative evolutionary rates for the COX6A heart (H) and liver (L) isoform genes along the length of the molecule, specifically in relation to the tissue-specific function(s) of the two isoforms. Nonsynonymous (amino acid replacement) substitutions in the COX6AH gene occurred more frequently than in the ubiquitously expressed COX6AL gene. Maximum-parsimony analysis and sequence divergences from reconstructed ancestral sequences revealed that after the ancestral COX6A gene duplicated to yield the genes for the H and L isoforms, the sequences encoding the mitochondrial matrix region of the COX VIa protein experienced an elevated rate of nonsynonymous substitutions relative to synonymous substitutions. This is expected for relaxed selective constraints after gene duplication followed by purifying selection to preserve the replacements with tissue-specific functions.      

A modular treatment of molecular traffic through the active site of cholinesterase

We present a model for the molecular traffic of ligands, substrates, and products through the active site of cholinesterases (ChEs). First, we describe a common treatment of the diffusion to a buried active site of cationic and neutral species. We then explain the specificity of ChEs for cationic ligands and substrates by introducing two additional components to this common treatment. The first module is a surface trap for cationic species at the entrance to the active-site gorge that operates through local, short-range electrostatic interactions and is independent of ionic strength. The second module is an ionic-strength-dependent steering mechanism generated by long-range electrostatic interactions arising from the overall distribution of charges in ChEs. Our calculations show that diffusion of charged ligands relative to neutral isosteric analogs is enhanced approximately 10-fold by the surface trap, while electrostatic steering contributes only a 1.5- to 2-fold rate enhancement at physiological salt concentration. We model clearance of cationic products from the active-site gorge as analogous to the escape of a particle from a one-dimensional well in the presence of a linear electrostatic potential. We evaluate the potential inside the gorge and provide evidence that while contributing to the steering of cationic species toward the active site, it does not appreciably retard their clearance. This optimal fine-tuning of global and local electrostatic interactions endows ChEs with maximum catalytic efficiency and specificity for a positively charged substrate, while at the same time not hindering clearance of the positively charged products.     

Diet-induced obesity in rats leads to a decrease in sperm motility

Background  

Obesity is rapidly becoming a worldwide epidemic that affects children and adults. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. Thus, the aim of the present study was to investigate the effect of high-fat diet-induced obesity on male reproductive parameters.