[Ribonucleolytic activity of mycoplasmas].

Mycoplasmas are incapable of de novo synthesis of nucleotides and must therefore secrete nucleases in order to replenish the pool of nucleic acid precursors. The nucleolytic activity of mycoplasmas is an important factor in their pathogenicity. Bacterial ribonucleases (RNases) may produce a broad spectrum of biological effects, including antiviral and antitumor activity.

Morphometric analysis of atherosclerotic plaques in human carotid arteries.

Morphometric analysis of 35 biopsy specimens from patients with stable (n=10) and unstable (n=25) atherosclerotic lesions was carried out. The structure of the plaques and their connective tissue caps was studied by various methods of histological sections staining. A new morphometric approach to quantitative evaluation of atherosclerotic lesions instability is suggested.

Bacteria and archaea involved in anaerobic digestion of distillers grains with solubles.

Cereal distillers grains, a by-product from bioethanol industry, proved to be a suitable feedstock for biogas production in laboratory scale anaerobic digesters. Five continuously stirred tank reactors were run under constant conditions and monitored for biogas production and composition along with other process parameters. Iron additives for sulfide precipitation significantly improved the process stability and efficiency, whereas aerobic pretreatment of the grains had no effect.

Sialidase activity in normal and atherosclerotic human aortic intima.

Sialidase activity has been determined in homogenates of human aortic intima by measuring the amount of GM1 formed during the incubation of ganglioside GD1a with the tissue homogenates. Areas with atherosclerotic lesions as well as adjacent areas without histological evidence of atherosclerosis were taken for comparison. The rate of GM1 formation from GD1a in the presence of homogenates of the atherosclerotic intima was 20 pmol/h per mg protein.

Proliferative activity and expression of cyclin-dependent kinase inhibitor p21WAF1 and p53 protein in endothelial cells of human aorta during replicative aging in vitro.

Experiments with bromodeoxyuridine showed that the count of nonproliferating cells in a monolayer culture of aortic endothelial cells from adult humans rapidly increased during long-term subculturing. Cytochemical assay showed that these cells contain neutral b-galactosidase, the marker of aging cells. Immunocytochemical assay demonstrated that most cells express p53 protein and inhibitor of the cell cycle p21WAF1.