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Biomedical subjects

V V Shevtsov

Publications and source records attributed to V V Shevtsov.

At least 19 recordsLinked to original sources
PubMed1992

[A system for the clinico-immunological prognosis of infectious-inflammatory complications in planned surgery].

Postoperative infectious complications in planned surgery are a pressing problem. The preoperative condition of the patient and his immune system play an important role in their development. Fifty patients of the "risk" group were selected from the standpoint of classification of the etiological factors of secondary immunodeficiency states. Fifteen patients who had no symptoms classified as SIDS risk factors formed the control group. The immune status was examined before and on the third day after the operation in all patients of the main and control groups. Various infectious complications developed after the operation in 23 patients of the risk group. No such complications occurred in the control group. The preoperative immune status of the risk group patients differed significantly from that of the controls in 13 of 19 parameters. The patients of the main and control groups formed the instructing selection. An expert system of preoperative clinico-immunological prognostication of postoperative infectious-inflammatory complications was created on oasis of the methods of the theory of image recognition and instructing selection. The system was tested in a direct clinical experiment on 66 patients. The prognoses were correct in 89% of cases. It was thus proved that symptoms classified as SIDS risk factors influence the initial immunity status and the course of the postoperative period in planned surgery. An accurate, sensitive, and specific method for prognosticating postoperative infectious complications is suggested.

Algorithms↗
PubMed1976

[Na, K-ATP-ase and acetylcholinesterase activity of the membrane structures of the rat brain and spinal cord during the seizure process].

The activity of ATP-ase and acetylcholinesterase (AChE) in crude mitochondrial fraction (CMF) and microsomal fraction of rat brain cortex and the spinal cord was studied in clonic seizures evoked by electroshock and 5 min after them. Inhibition of the Na, K-ATP-ase activity of the CMF of the brain at the clonic phase of convulsions and an increase in the activity of this enzyme in all the fractions of the tissues under study at the postconvulsive period were revealed. The activity of Ca-ATP-ase in the CMF of the brain increased during the convulsions and decreased at the postconfulsive period. The activity of Mg-ATP-ase remained unchanged. The AChE activity, as a rule increased during the convulsions, and grew even more during the postconvulsive period; the spinal cord tissue displayed a reduction of the activation effect. A possibility of structural reconstructions in the excitable neuron membranes during the convulsive activity is discussed.

Acetylcholinesterase↗
PubMedDate not supplied

[Growth and spore germination factors of various strains of Bacillus sphaericus].

The work was aimed at studying the requirements of sixteen Bacillus sphaericus strains with a different larvicidal activity in amino acids and some other compounds necessary for their growth and spore germination. Most of the strains were found to require arginine, glutamate, methionine, threonine, serine, glycine, alanine and lysine, but they did not assimilate phenylalanine and proline. Arginine, methionine and glutamate were shown to be the most effective inductors of spore germination. Specific differences were detected in the requirements of virulent and avirulent strains. Glucose repressed both spore germination and spore formation.

Amino Acids↗
PubMedDate not supplied

[Chemical mutagenesis and the use of indirect enzymatic criteria for the selection of virulent clones of Bacillus thuringiensis].

The effect of the mutagene nitrosoguanidine (N-methyl-N'-nitro-N-nitrosoguanidine) on the growth of Bacillus thuringiensis subsp. galleriae st. 69/6 was being studied. It depends on the physiological state of the cells, dose of the mutagene, pH of the culture medium and exposition. Nitrosoguanidine was found to have the maximum mutagenic effect on the vegetative cells at pH 6.2 and on the spores at pH 5.6.

Bacillus thuringiensis↗
PubMedDate not supplied

[Effect of mineral salts on exotoxin formation and productivity of a Bacillus thuringiensis culture].

The effect of ten mineral salts on the productivity and toxin synthesis was studied in Bacillus thuringiensis IPM-1140. Exotoxin synthesis was stimulated by Zn2+, Mn2+ and NH4+ ions as well as by potassium phosphates. The direct correlation between the number of viable spores and the exotoxin accumulation was disordered at extreme salt concentrations. Optimal salt concentrations in the yeast-polysaccharide medium were found using the method of a fractional factor experiment, which made it possible to increase the productivity of the culture to 5 X 10(9) spores/ml and the yield of the exotoxin to 730 micrograms/ml. The thermoresistance and the entomopathogenic activity of crystals increased when B. thuringiensis IPM-1140 was grown in this medium.

Bacillus thuringiensis↗
PubMedDate not supplied

[Possible means for increasing exotoxin synthesis by a Bacillus thuringiensis culture--the producer of bitoxibacillin].

Various procedures were studied for obtaining Bacillus thuringiensis strains of serotype I which synthesized exotoxins. Mutant clones with elevated exotoxin synthesis could be selected by treating the cells with N-methyl-N-nitro-N-nitrosoguanidine. The frequency of (+) variant selection was from 17 to 12 X 10(-2). The clones of S and R types differed in the insecticide activity of the exotoxin. Its yield could be increased by optimizing the composition of growth media. The strain specificity of B. thuringiensis producing the exotoxin was assayed in terms of carbon and nitrogen requirements.

Animals↗