Physiological Mechanisms of the Effect of Modulated Kinesotherapy on the Circulatory System

A new method of modulated kinesotherapy (MK) involving foot-paced movement (walking and running) with the pace and heart rate synchronized by means of a specially developed Marafon training device is described. In healthy subjects and patients with coronary disease complicated by functional class I or II (FC I–II) angina, the heart rate (HR) decreased by 20–25% during the MK; after the MK, the period of normalization of the HR decreased by 30%, relative to the control. The double product index, an integral representation of the circulatory efficiency, decreased by 15–20%. Normalization of the systolic component (on the average, 62.4 and 64.2% increase in the stroke volume and the end-diastolic volume, respectively) and diastolic function (40 and 43% increase in the peak left ventricular early filling rate and the ratio of the peak early filling rate to the atrial filling rate, respectively) was observed. The indications for and the contraindications to the MK application are specified.     

The effect of experimental diabetes on the molecular characteristics of soluble rat-tail tendon collagen

Acid soluble rat-tail tendon collagen was prepared from animals rendered diabetic by treatment with either streptozotocin or alloxan and from matched controls. In comparison to the normal, the diabetic collagens consistently demonstrated decreased solubility of reconstituted fibrils, marked increase in intrinsic viscosity and a decreased ratio of alpha to beta components. Electrophoresis in sodium dodecyl sulfate-polyacrylamide gels revealed a marked decrease in migration of alpha1, alpha2, and beta components from both types of diabetic collagen. These data indicate that diabetic collagens are larger than normal and are capable of higher degrees of polymerization due to increased intra- and inter-molecular interactions. These changes could explain, in part, the altered response of diabetic connective tissues to inflammation and trauma.     

Analysis of the Actinobacillus actinomycetemcomitans leukotoxin gene. Delineation of unique features and comparison to homologous toxins

Actinobacillus actinomycetemcomitans leukotoxin has been implicated as a virulence factor in human infections. To initiate delineation of leukotoxin structure/function relationships, molecular cloning of the leukotoxin gene was carried out. When an A. actinomycetemcomitans genomic DNA library in lambda EMBL3 was screened using a 1.3-kilobase pair restriction fragment containing a portion of the leukotoxin gene, 13 positive recombinants were identified. One recombinant, designated lambda OP8, containing a 16-kilobase pair insert was selected for detailed study. Lysates from lambda OP8, but not control lysates, exhibited leukotoxic activity with target cell specificity identical to the native toxin. Western blots identified the recombinant-produced toxin as a 125-kDa protein doublet identical in mobility to the native toxin. Restriction enzyme and extensive DNA analyses demonstrated that the leukotoxin gene showed strong homology to two other toxins produced by Escherichia coli and Pasteurella haemolytica. As in the other two species, the A. actinomycetemcomitans toxin is contained in a cluster of four genes in which the A gene encodes the toxin and the products of the B, C, and D genes are involved in posttranslational modification of the toxin and its membrane insertion and secretion. The target cell specificity of the A. actinomycetemcomitans toxin differs from the other two toxins and is restricted to human and some non-human primate cells of the monomyelocytic lineage. The A. actinomycetemcomitans leukotoxin is not secreted but remains associated with the bacterial membrane, possibly through a hydrophobic domain at the carboxyl terminus which distinguishes it from the E. coli and P. haemolytica toxins.     

Biomarkers of toxicity in Clarias gariepinus exposed to sublethal concentrations of polycyclic aromatic hydrocarbons

Physiological, biochemical and histological indices in Clarias gariepinus broodstock, and teratogenic indices in embryos exposed to sublethal concentrations of naphthalene, phenanthrene and pyrene were investigated in 2014 using a static-renewal bioassay protocol. Phenanthrene (1.41 mg l^?1) was the most toxic, followed by pyrene (1.53 mg l^?1) and naphthalene (7.21 mg l^?1), based on 96 h LC50 values. Hepatosomatic indices were significantly higher in naphthalene- and pyrene-treated males compared with solvent controls, whereas fecundity in females was significantly lower by factors of 2.4 (naphthalene), 2.8 (phenanthrene) and 2.4 (pyrene), compared with controls. Catalase levels were lower in female phenanthrene-treated fish compared with controls. Histological alterations observed in PAH-treated fish include oedema, inflammatory cells, epithelial lifting and hyperplasia in the gills, vacuolation, haemosiderin pigments and sinusoidal congestion in the liver, and degenerated zona radiata in the ovary. Teratogenic effects were not observed, as evidenced by the lack of histological alterations in embryos spawned from pre-exposed broodstock. Sex-specific responses and the utility of biomarkers at cellular and individual levels of organisation are therefore demonstrated for holistic evaluations of polycyclic aromatic hydrocarbons in ecotoxicological studies.     

A novel nucleic acid-binding protein that interacts with human rad51 recombinase.

Using the yeast two-hybrid system, we isolated a cDNA encoding a novel human protein, named Pir51, that strongly interacts with human Rad51 recombinase. Analysis in vitro confirmed the interaction between Rad51 and Pir51. Pir51 mRNA is expressed in a number of human organs, most notably in testis, thymus, colon and small intestine. The Pir51 gene locus was mapped to chromosome 12p13.1-13. 2 by fluorescence in situ hybridization. The Pir51 protein was expressed in Escherichia coli and purified to near homogeneity. Biochemical analysis shows that the Pir51 protein binds both single- and double-stranded DNA, and is capable of aggregating DNA. The protein also binds RNA. The Pir51 protein may represent a new member of the multiprotein complexes postulated to carry out homologous recombination and DNA repair in mammalian cells.