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Biomedical subjects

A T Kravchenko

Publications and source records attributed to A T Kravchenko.

At least 19 recordsLinked to original sources
PubMed1988

[Cytotoxic action of the chemical substances found as admixtures in medical immunobiological preparations].

The cytotoxic action (CTA) of chemical substances contained as admixtures in medical immunobiological preparations on human diploid cells has been studied. Such chemical substances as rivanol and merthiolate in admissible concentrations show the highest degree of CTA. The results obtained in this investigation indicate that different concentrations of chemical substances may produce equal CTA; thus, thiolate in toxic in a dose of 0.8 microgram/ml; the same CTA is produced by aluminium sulfate in a concentration of 500 micrograms/ml. Small doses of chemical substances, producing no explicit manifestations of the cytotoxic effect, may have latent CTA determined by additional methods of investigation. CTA may be manifested as lethal, sublethal and latent cell lesions. In working out regulations on the test for CTA it is expedient to indicate admissible residual amounts of chemical substances contained in finished medical immunobiological preparations, considering that these amounts must be incapable of producing CTA in cell cultures. The conclusion has been made on the expediency of denoting small amounts of chemical substances capable of producing latent CTA as tentatively tolerable doses.

Biological Products↗
PubMed1986

Acquired immunity and allergy of cells cultured in vitro.

It is in the reinoculated cell line FL that the sensitivity of cells under the action of a small dose of diphtheria toxin (DT) changes to the toxin itself as well as to the Coxsackie enterovirus. (B-5). After surviving the infection and getting again "healthy", the cells have acquired simultaneously an elevated sensibility to DT and reduced susceptibility to B-5 transmissible even in long passages. These acquired properties are a transient phenomenon, after a certain number of passages the culture returns to initial stage with all properties inherent in the initial line of cells: with regard to DT in 10 months, to coxsackie virus in 7 months. The stage of elevated sensibility to DT and reduced susceptibility to B-5, however, may be not only renewed but also considerably prolonged and even strengthened by repeated contact of cells with a small dose of DT. The small dose of DT is the first delusion of the toxin not provoking any visible morphological changes in the monolayer. The experimental data obtained render it possible to presume that application of reinoculated cell cultures offers a promising method for studying manifestations of laws governing the third factor of immunity and allergy at the level of cells.

Cells, Cultured↗
PubMed1986

[Use of a diploid cell line for detecting the toxic components in medical immunobiological preparations].

Besides specific antigens medical immunobiological agents (MIBA) contain chemical compounds (formaldehyde, aluminium hydroxide and mercury salt, merthiolate) in permissible concentrations. Therefore, the investigation of MIBA and their components should involve methods studying the effect of chemical compounds on cells and their structural components. For this purpose WHO recommends to use cell cultures. The results obtained show that cell cultures (constant and diploid lines) allow the differentiation in the degree of toxicity of chemical compounds constituting MIBA. Merthiolate had the strongest irreversible lethal effect. The technique can prove useful for more accurate evaluation of toxicity in inactivated bacterial and viral vaccines as well as in serum preparations. Cell culture can be successfully used for the detection of toxic components in vaccines and serum drugs, with the final safety tested by their injection to animals.

Aluminum Hydroxide↗
PubMed1979

[Effect of small doses of diphtheria exotoxin on cell cultures].

High diphtheria exotoxin concentrations induced irreversible injuries to all the cultures under study (L, HeLa, spcv pzM). However, its final titres in the mentioned cells differed. HeLa and pzM cells, being highly sensitive, can be recommended for titration of dipheria exotoxin, instead of the expensive guinea pig tests. Low (subtoxic) doses produced cytoproliferative action and caused changes of the cell properties.

Animals↗
PubMed1978

[Rational method of obtaining sera with a high titre of virus-neutralizing antibodies. Report 2].

In addition to report I (ZHMEI, 1977, No. 1) a study was made of 9 more schemes of rabbit immunization with the poliomyelitis virus, type I, for the purpose of obtaining the neutralizing sera of high titre. Vitamins A and C were used in the experiments in the capacity of the activators of the organism reaction; Freund's adjuvant of different make was tested; different reimmunization periods and different amounts of the adjuvant were administered. Titration of rabbit sera in the process of immunization and reimmunization showed immunization into the lymph nodes with the subsequent single reimmunization in one month to be the most effective and economical method of obtaining high effective sera.

Animals↗
PubMed1978

[1st stage of infectious allergy].

In administration of bacterial exotoxins (diphtheria, botulinic) to guinea pigs in doses of 1/100 Dlm at an interval of one hour there developed a typical sickness with the lethal outcome in the course of 2-3 days from the beginning of the exotoxin administration. Low bacterial exotoxin doses induced allergic reaction of the organism before the cell producing specific antibodies began to act in defence. Lymphatic system cells responded rapidly to the low doses of bacterial exotoxins, but the process of formation of cells producing antibodies failed to reach mature plasmocytes, and no antibodies formed. With increase of the interval between the administration of low bacterial exotoxin doses to 24 hours specific antibodies did form, but these antibodies failed to protect the animals which were in the state of infectious allergy. The first stage of infectious allergy induced by low bacterial doses was nonspecific. Animals which were in the state of infectious allergy to diphtheria exotoxin perished of low botulinic (exotoxin) doses, and vice versa.

Antibodies, Bacterial↗
PubMed1977

[Rational method of producing sera with high titers of virus neutralizing antibodies].

A possibility of obtaining the diagnostic specific sera with a high titre against the poliovirus, type I, was studied experimentally. Five different immunization schemes by the same antigen were tested in parallel experiments. A method of the viral antigen (both of the concentrated and of the unconcentrated) mixed with complete Freund's adjuvant injection into the popliteal lymph nodes with the subsequent single reimmunization proved to be most effective. In this way it was possible to obtain type-specific sera with a high titre (1:20 000--1:40 000) in the course of five weeks.

Animals↗
PubMed1976

[Effectiveness of specific treatment of rabies. II. Analysis of cases of human death from rabies following a complete course of treatment with specific agents].

Of 79318 persons treated of rabies in the Uzbek SSR in 1968--1974 there were recorded 16 cases of death of clinically manifest rabies. The course of treatment included injection of rabies gamma-globulin in a dose of 0.5 ml per 1 kg of body weight and the maximal dose of rabies vaccine. The incubation period lasted from 44 to 833 days (229.6 on the average). The authors considered that irrational use of high doses of rabies preparations was the cause of unsuccessful treatment of rabies.

Adult↗
PubMed1975

[Infectious allergy. XIV. Histochemical changes in redox enzymes in cells of the small intestine smooth muscle during sensitization with diphtheria exotoxin].

Administration to guinea pigs of 1/Dlm of diphtheria exotoxin twice at an interval of 1 and 24 hours, or once in a dose of 25/100 Dlm caused changes in the activity of the redox enzymes. The character of their changes in the animals to which the whole dose of the exotoxin was administered once or repeatedly was directly reverse: in the first case the activity of the enzymes was uniformly increased, and in the second--ununiformly depressed; besides, there was a marked disturbance of coordination between the enzymes. An increased sensitivity of the infectious allergy type following injection of low doses of diphtheria exotoxin was not accompanied by immunity formation. Specific antibodies against diphtheria exotoxin formed only in the organism of animals to which 1/100 Dlm of diphtheria toxin was injected once a day for 15 days, but in this case as well no immunity against diphtheria exotoxin was observed.

Animals↗