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Biomedical subjects

Z Zaprianov

Publications and source records attributed to Z Zaprianov.

27 records · Page 2Linked to original sources
PubMed1988

Histological grading, DNA content, cell proliferation and survival of patients with astroglial tumors.

Light microscopy, image cytometry (ICM), and flow cytometry (FCM) were used to study the degree of differentiation, DNA content, and S-phase of astrocytomas and glioblastoma multiforme in 102 patients. The postoperative real survival time (RST) was also studied. Using ICM, 62 astrocytomas were investigated. Grade I astrocytomas were composed of DNA-diploid cell lines, while grade III and glioblastoma multiforme consisted predominantly of DNA-aneuploid lines. Moderately differentiated astrocytomas were divided as follows: 14 DNA-diploid and 18 DNA-aneuploid. Forty astrocytomas were studied by FCM. Using the DNA index (DI) value, cases with abnormal DNA cell lines were established in all astrocytomas, with their number increasing in grades II and III astrocytomas. FCM indicated the same subdivision of moderately differentiated astrocytomas: 12 with DNA-diploid and 12 with DNA-aneuploid stem lines. Patients with DNA-diploid cell lines in the astrocytomas and low S-fraction survived longer than patients with abnormal DNA cell populations and higher S-fraction. The results from this study indicate that, together with the degree of differentiation of astroglial tumors, the appearance of cell lines with abnormal DNA value and higher S-fractions also have prognostic value.

Adolescent↗
PubMed1988

[The occupational risk in the manufacture of mineral pigments and iron oxide dyes].

The mineral pigments and ferric oxide dyes are used on a large scale in the paint and varnish industry, in building, chemical industry, polygraphy etc. For their production as basic raw materials are used lead, chromium and iron compounds. The concentrations of the toxic and accummulating lead and chromium in the air of the work environment surpass MAC and create most frequently "especially unfavourable" conditions of work. In all industrial processes the leading unfavourable factor is the chemical combined with unfavourable physical factors and overstress on the locomotor system. Changes were established in the organism of examined workers as result from the chronic effect of the factors of the work environment of the peripheral blood, digestive, nervous system and the skin. In view of reducing the risk of exposure to the toxic chemical factor it is imposed to take measures for sanitation of the work environment.

Absenteeism↗
PubMed1982

[Prognosis and determination of the threshold of chronic effect of carbon disulfide and styrene].

Two series of studies were carried out: I--in workers exposed to four different mean annual CS2 concentrations--6 mg/m3; 12 mg/m3; 51 mg/m3 and 247 mg/m3 and II series-in workers exposed to three styrene concentrations--I mg/m3; 40 mg/m3 and 400 mg/m3. The results obtained in series I show the role of the primary toxic effect (inhibition of oxidases with mixed function) and of the adaptation reactions to it with a view to accurate specifying the threshold of chronic CS2 effect. The mathematical expression of the correlation between styrene concentration in air and blood, of phenyl-glyoxylic and mandelic acid in the urine of the exposed subjects enables the prognosis that the threshold of the noxious styrene effect is within the range of 150 mg/m3 to 250 mg/m3. A reduction on CS2 MAC is proposed--from 10 mg/m3 to I mg/m3 and the correction of styrene MAC--from 5 mg/m3 to 30-50 mg/m3.

Adult↗
PubMed1981

Inhibition of monoamine oxidase activity after combined action of chlordimeform with the antidepressant nialamide.

The 40-day oral administration of 5, 10, and 50 mg/kg chlordimeform to male rats moderately decreased monoamine oxidase activity (MAO) in the brain, liver, and serum, determined with the substrates kynuramine, tyramine, tryptamine, serotonin, dopamine, and benzylamine. The enzyme was inhibited predominantly in the liver. The study of MAO inhibition after 10 days application of 2, 6, 10, 15, and 20 mg/kg nialamide revealed that 2 mg/kg had a threshold effect. A dose of 6 mg/kg resulted in a pronounced decrease in the enzyme activity. Experiments with a 30-day application of 5, 10 and 50 mg/kg chlordimeform were made, followed by treatment with 6 mg/kg nialamide in combination for another 10 days. The statistical evaluation by the Student's t-test demonstrated increased MAO inhibitory action. Dose-effect relationship was established with kynuramine in liver, brain, and serum, and with benzylamine in liver.

Amidines↗
PubMed1976

[Lysosomal enzyme activity in the serum of rats with experimental lead poisoning].

Examination of the effect of experimental lead poisoning on permeability of lysosomal membranes in albino rats demonstrated activation of lysosomal enzymes (alpha-manosidase and beta-acetylglucosaminidase) in the blood serum as soon as the third day after daily administration of lead acetate (20 mg/kg). Apparently damage of the lysosomal membrane played an important role in the pathogenesis of lead poisoning.

Acetylglucosaminidase↗
PubMedDate not supplied

[Changes in the quantity of nucleic acids in the liver and kidneys of rats with experimental lead poisoning].

In the liver and kidneys of 125 control and test albino rats poisoned perorally daily with different doses of neutral lead acetate for 1, 3, 5, 10, 20, 30 and 45 days the RNA and DNA contest was measured. A statistically significant increase of nucleic acids was registered in both organs, earlier and stronger pronouced in the liver than in the kidneys. The amount of DNA changed quicker than that of DNA. In all the groups of animals the rise in the content was proportional to the introduced amount of lead (20, 40 and 100 mg/kg body weight). Following poisoning with 20 mg/kg of lead acetate the DNA and RNA accretion (statistically significant) remained after the 10th day roughly the same till the 45th day. The main reason for the DNA increment in the study organs seems to be an intensive synthesis, the rise of RNA is due to an inhibited activity of ribonuclease.

Animals↗