Model of a chronic Vibrio cholerae carrier based on gnotobiotic rats

Germ-free monoflora (contaminated with nonpathogenic spore-bearing bacillus) and common albino rats (OFA) were infected with V. cholera El Tor, of Ogava and Inaba serological types (6 milliard microbial cells per 1.5 ml of physiological solution per rat). Approximately one week after the infection the number of vibrios reached hundreds of millions per 1 g of feces and persisted at this level for over 100 days (observation period). Newborn rats were infected by natural way from adult vibrio carriers and also became vibrio-carriers. The number of vibrios excretedby the animals which were germ-free and monoflora before the infection was approximately the same. Cholera vibrios perished completely in the enteric tract and were never revealed in the feces of common (control) rats.     

Electrical response of inner membrane structures of corynebacteria during electrotransformation

The efficiency of the electrotransformation of intact cells of corynebacteria by a solitary impulse with a complex shape amounted to 10(6) transformants/microgram of plasmid pNV1 DNA at an electric field strength of 14.2 kW/cm; the voltage-current curve of the cell samples was nonlinear. Under these conditions, the structure of the electric current impulse passing intact cells or protoplasts included oscillations characterized by increasing amplitude and a duration of 170 microseconds, which were not detected in the structure of the electric current impulses at field strengths insufficient for obtaining transformants. These changes in the impulse shape suggest the involvement of internal closed membrane structures in the electrical response of cells to the exogenous electric impulse. Most probably, under conditions of electrical treatment optimal for transformation, electropores are formed in the intracellular membranes of corynebacteria.     

Cytotoxic properties of the complex of the antineoplastic antibiotic bleomycetin and Bacillus intermedius ribonuclease

It was shown possible to change the cytotoxic properties of the antitumor antibiotic bleomycetin by its binding to Bacillus intermedius RNAse. The complexing lowered the antibiotic effect on DNA in the cells of the human amnion. At the same time the experiments with human red blood cells indicated that RNAse of B. intermedius in complex with bleomycetin-Fe(II) increased the antibiotic capacity for the cell membrane break down.     

Sexual behavior and alpha-2 adrenoreceptors in the neocortex of male rats after castration and testosterone administration

Castration of male rats inhibited their sexual behaviour and increased the density of the alpha-2 adrenergic receptors in the brain cortex. Treatment of castrated or intact males with testosterone activated their sexual behaviour and decreased the receptor density in the brain cortex. The obtained evidence testify to the involvement of the brain alpha-2 adrenergic receptors in the effect of testosterone on male sexual behaviour.     

Vasoactive factors in patients with a severe combined trauma]

An analysis of a 35-years experience with organ-saving surgical treatment of 13,751 patients with diseases of the thyroid gland has been made. The basic principles of prevention of recurrent diseases and specific postoperative complications are formulated. An original technique of operations resulting in less frequent injuries of the recurrent nerves, hypoparathyrosis and postoperative lethality after surgical treatment of patients with benign diseases and carcinoma of the thyroid gland has been developed.     

The diagnosis of occupational myofibrosis]

110 cases of resection of the stomach with transection of the stomach and the duodenum by plasmic scalpel and suturing of curvatura minor of the stump and anastomosis with the use of original one-layer sero-muscular-submucosal suture have been analysed. Changes in gastric wound at the site of plasma transection were evaluated microscopically. It was established that plasma transection of the stomach is aseptic, hemostatic, thermal trauma is minimal and does not exceed the level of 3-4 mm from transection line. Favourable conditions for applications of one-layer suture contribute much to a decrease of the number of stitch puncture, to rejection of catgut, to reduction of tissue mass involved and deformation of intestinal wall. In the early postoperative period wound and anastomoses healing occurred without substantial inflammatory changes. 109 patients were operated by Billroth-1 and 1 patient--by Billroth-II. One patient died (lethality 0.9%). Early postoperative complications occurred in 7.2% of operated patients.     

Features of DNA repair during chronic exposure to mutagenic factors

Long-time in vivo influence of chemical mutagens in low doses can decrease the level of unscheduled DNA synthesis (UDS) induced in human as well as in laboratory mammals. The phenomenon under investigation is not specific neither for chronically acting mutagens nor for challenging agent. A decrease in UV- and gamma-ray-induced UDS was registered after chronic irradiation in plant populations and also in Chernobyl ameliorators and inhabitants of radioactively contaminated regions. The observed effect seems to have general biological character.     

Errors in the photometric determination of the standard deviation of a surface profile

A comparative analysis is presented of the precision parameters of different variants of the photometric method of measuring the standard deviation from surface profiles R _q.A variant by means of which the maximal precision of measuring R _q over a broad range of values is determined.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 37–39, April, 1995.