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Biomedical subjects

V A Shamardin

Publications and source records attributed to V A Shamardin.

18 recordsLinked to original sources
PubMed1991

[A method of rapid indication of an antigen].

A simple and sensitive method for rapid detection of an antigen is offered. 0.025 ml of antiserum is placed on the slide, 0.025 ml of clarified extract containing the antigen added, and then 0.025 ml of intact 20.10(6) suspension of Kowan 1 Staphylococcus strain is added. When antigen-antibody complex is forming, staphylococcal cell aggregation starts. A staphylococcal reagent, manufactured by the Pasteur Research Institute of Epidemiology and Microbiology in Leningrad, may be employed, this making the method more available. The indication sensitivity is 0.2-1.25 mln cells per ml, this value depending on the bacterial species.

Antigens, Bacterial↗
PubMed1986

[Escherichia-erythrocyte diagnostic agents].

The conditions of a simple and practicable method for the preparation of effective antigenic nonprotein diagnosticums on the basis of water-phenol extracts of 23 Escherichia species have been developed. The method consists in heating the mixture of erythrocytes and the antigen in a boiling water bath for 60 minutes. The diagnosticums thus obtained are 16-30 times more sensitive in the passive hemagglutination test and 4-6 times more sensitive in the passive hemagglutination inhibition test than diagnosticums prepared with the use of tannin, rivanol, as well as by the common method for the preparation of nonprotein antigens. The minimum concentration of Escherichia cells detected in the passive hemagglutination inhibition test is 0.8-1.2 million cells/ml.

Antibodies, Bacterial↗
PubMed1979

[Comparative evaluation of different globulin preparations and of the means for blood sensitization in obtaining antibody erythrocytic diagnostica].

In comparing the hemosensitizing activity of various immunoglobulin preparations with different methods of erythrocyte loading the greatest activity and specificity was revealed in IgG isolated by means of DEAE-Sephadex A-50. The method of erythrocyte sensitization with the use of alizarin blue indicator was more advantageous in respect to sensitivity and specificity of Sh. sonnei and Newcastle indication over Boyden's, Jandl and Simmons', Bing's methods.

Animals↗
PubMed1978

[Nonspecific means of increasing the sensitivity of the passive hemagglutination reaction].

The effect of some methods of preliminary treatment of erythrocytes on the PHAT depended on the sensitin náture and the method of erythrocyte load. In case of erythrocyte load with nonprotein and immunoglobulin sensitins without any conjugating agents the simulating effect of heating and periodate treatment was caused not by increase of stable sensitin binding, but by the reduction of physico-chemical resistance of erythrocytes. This effect of erythrocyte treatment permitted to increase the sensitivity of the antibodies and antigens determination. In loading the erythrocytes with the aid of conjugating agents and in sensitization with protein antigens after Boyden no stimuating effect of the treatment was noted.

Animals↗
PubMed1977

Interaction of erythrocytes with human serum proteins. II. Dependence of the process on the concentration of protein, exposure and temperature of medium.

The effect of concentration of human serum proteins, duration of contact and temperature of the medium on the process of their interaction with formalized, tannin-treated sheep erythrocytes was studied. Dependence of the process of specific haemosensitization on the enumerated factors was established. The character of the process of haemosensitization by serum proteins and its dependence on the concentration of sensitins and the duration of the contact with them can be expressed by Langmuir's equation. On the basis of limited preliminary experiments it is thus possible to define the optimum conditions for the loading of erythrocytes.

Blood Proteins↗
PubMed1977

[Selecting a method of erythrocyte fixation for the passive hemagglutination test according to the nature of the sensitin].

Quantitative methods were applied to the study of the interaction of albumins, fraction I of Plague bacilli, diphtheria toxoid fractions differing by mol wt, flagellin of typhoid bacilli, 19S- and 7S-fractions of normal human, cholera horse, and paratyphoid B donkey sera with erythrocytes, fixed by 10 different methods. Fixation with acetaldehyde proved to be optimal for the binding of all the proteins, including flagellin, but the latter sensitized erythrocytes formalinized after Vainbach better. The significance of the method of erythrocyte fixation and of the nature of sensitin in the process of the erythrocyte loading without any utilization of the conjugating agents was demonstrated.

Adsorption↗
PubMed1976

[Relationship between blocking the erythrocyte surface and the quantity of IgG molecules bound in the process of hemosensitization].

Under different conditions of the IgG-sensitization of the tannin-treated erythrocytes a determination was made of the degree of blocking the cell surface. There was shown a reverse relationship between the amount of the bound IgG molecules and their portions bound by the surface with the maximal cross-section. Fixation of the IgG by means of CH2O at the end of sensitization led to the additional blocking of the erythrocyte surface. The limit of the erythrocyte saturation with the IgG molecules was controlled by the greatest possible density of the globulin molecules localization.

Antigen-Antibody Reactions↗
PubMed1976

Interaction of erythrocytes with human serum proteins. I. Analysis of the effect of pH and ionic strength of the medium.

The effect of ionic parameters of the medium (pH and ionic strength) on the processes of interaction of tannin-treated erythrocytes and the protein fractions of human serum (macroglobulins, microbulins and albumin) was studied in factorial experiments. Complex effect of these parametres on the processes under investigation and optimum conditions of erythrocyte sensitization were established. Subsequent fixation of antibodies by the erythrocyte diagnostic and their agglutinating activity are manifested in different mannera depending on the conditions of preceding sensitization. Important peculairities were discovered in the mechanism of interaction between the erythrocytes and various serum proteins. The obtained results should be taken into account in the production of erythrocyte antigen and antibody diagnosticums.

Blood Proteins↗
PubMed1976

Interaction of erythrocytes with human serum proteins. I. Analysis of the effect of pH and ionic strength of the medium.

The effect of ionic parameters of the medium (pH and ionic strength) on the processes of interaction of tannin-treated erythrocytes and the protein fractions of human serum (macroglobulins, microglobulins and albumin) was studied in factorial experiments. Complex effect of these parametres on the processes under investigation and optimum conditions of erythrocyte sensitization were established. Subsequent fixation of antibodies by the erythrocyte diagnostic and their agglutinating activity are manifested in different mannera depending on the conditions of preceding sensitization. Important peculiarities were discovered in the mechanism of interaction between the erythrocytes and various serum proteins. The obtained results should be taken into account in the production of erythrocyte antigen and antibody diagnosticums.

Animals↗
PubMed1976

[Molecular parameters of the sensitization of tannined erythrocytes with human IgG].

A study was made of the molecular binding parameters during the sensitization of human IgG with tannin-treated sheep erythrocytes, depending on the concentration of the reacting components. The total amount of IgG molecules stably bound by all erythrocytes increased with the elevation of erythrocyte and IgG concentration. About 1.7 million IgG molecules were stably fixed on one erythrocyte under conditions providing the maximum binding. However, the level of hemosensitization approaching the maximum was provided by binding 400,000--600,000 IgG molecules by one erythrocyte. Apparently the level of specific IgG sensitization was determined not only by the amount of protein molecules stably bound by one erythrocyte, but also by the character of space position of the IgG molecules on the erythrocyte surface.

Binding, Competitive↗