Selective inactivation of MAO-B by benzyl-dimethyl-silyl-methanamines in vitro

The alpha-silyl amines benzyl-dimethyl-silyl-methanamine and the p-fluoro and p-chloro derivatives are potent time-dependent inhibitors of rat brain MAO-B. The inhibition exhibits saturation kinetics, takes place in the enzyme active-site and is irreversible. The most potent inhibitor in the series is 4-fluorobenzyl-dimethyl-silyl-methanamine (KI = 11 microM, tau 1/2 = 2.3 min). Its selectivity for the B-form relative to the A-form of rat brain MAO is higher than 10(4). Benzyl-dimethyl-silyl-methanamines may represent a new family of anti-Parkinsonian agents.     

Analysis of the structure and expression of the c-myc oncogene in cervical tumor and in cervical tumor-derived cell lines

The structure of the c-myc oncogene in 17 cervical tumors and patient-matched nontumor tissues from Chinese patients residing in Taiwan was analysed. In contrast to recent reports on Mexican patients, none of the samples showed rearrangements and sequence amplification in the c-myc gene. The discrepancy may be explained by different carcinogenesis mechanisms being in operation in different geographic regions. Although no structural alterations in the c-myc gene were found in seven cervical carcinoma cell lines analysed, Northern blot analysis indicated different levels of c-myc gene expression which may be related to the presence of human papillomavirus (HPV) sequence in the cell and suggests a possible c-myc-hpv interaction in some stages of the transformation process.     

Mast cell and blood coagulation functions during prolonged noradrenaline administration

During the long term noradrenaline injection (0.56 microgram/kg/min-2 hours during six days) the number of connective tissue mast cells decreases in dogs. Mature cells disappears and the percentage of young forms increases. Marked degranulation develops. 5-10 cell groups and chains are formed. The increase of free heparin level and the activation of anticoagulant unit hemostasis correspond to these changes. It is due to mast cells discharge of biologically active heparin which is an unspecific adaptogen.     

An analysis of a process for culturing Lactobacillus acidophilus using a method of spectroturbidimetry

Changes in the spectrum of the opacity of biodispersions containing L. acidophilus at the stage of growth have been studied. The pronounced positive correlation between the opacity of dispersion and the titer of cells, determined by the method of ultimate dilutions, have been shown.     

Protection of the monoamine oxidase in brain synaptosomes by fat- and water-soluble antioxidants during lipid peroxidation

The protective effects of alpha-tocopherol, carnosine and their mixtures on monoamine oxidase activity, accumulation of lipid peroxidation products, lipid fatty acid composition, hydrophobicity and microviscosity of synaptic membranes during lipid peroxidation were studied. It was shown that the protective efficiency is more higher when the mixture of water and liposoluble antioxidants was used.     

Interaction of T-activin with peritoneal macrophages

The action of T-activin on peritoneal macrophages of CBA mice after its introduction into the animals has been studied. In intact mice the phagocytic activity of macrophages and their resistance to the cytopathogenic action of Salmonella typhimurium live cells remains unchanged. The injection of corpuscular pertussis vaccine into mice leads to a decrease in the resistance of macrophages to the action of salmonellae. The simultaneous injection of T-activin into mice in doses of 0.1 and 1.0 microgram per animal abolishes the damaging action of the vaccine. The analysis of the in vitro action of T-activin on macrophages of intact mice revealed that the preliminary incubation of cells with the preparation sharply increases their resistance to the action of salmonellae, while its introduction simultaneously with bacteria or after them rapidly leads to the death of macrophages. The action of T-activin is supposed to be linked with triggering the biosynthetic processes mediating the resistance of macrophages to the cytopathogenic action of salmonellae.     

A nuclear yeast gene (GCY) encodes a polypeptide with high homology to a vertebrate eye lens protein

We describe here the nuclear gene for a yeast protein showing unexpectedly high homology with mammalian aldo/keto reductases as well as with p-crystallin, one of the prominent proteins of the frog eye lens. Although it could be proven that the gene occurs as a single copy in the haploid yeast genome, replacement of the intact by a disrupted, nonfunctional allele led to no obvious phenotype, indicating that the gene is dispensable. The gene was assigned to chromosome XV. It is transcribed in vivo into an mRNA of about 1300 bases with a coding capacity for a protein of 312 amino acids (estimated Mr 35,000).