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Biomedical subjects

P Atanasiu

Publications and source records attributed to P Atanasiu.

At least 37 records · Page 2Linked to original sources

Rapid immunoenzymatic technique for titration of rabies antibodies IgG and IgM.

This report is concerned with the application of the enzyme immunoassay to measure the antibodies in humans vaccinated against rabies or presenting symptoms of rabies without having been vaccinated. By the same technique we identify the IgG and IgM classes of antibodies. The antigen (5 microgram/ml), purified virus, is readily adsorbed into polystyrene tube by passive adsorption. The use of only one dilution for each serum assay (1/200) is particularly suitable for epidemiological studies. Antibody response of subjects in the course of rabies vaccination was an obvious application. After 5 inoculations of tissue culture vaccine the IgM response was poor and late; it was even negative in two cases. The IgG response appeared early on the 7th day. In the same way we tried to follow antibody response in three cases of rabies in man. Seroneutralisation (SN) antibody were not detected at the beginning of the illness. In case 1 antibodies were found on the 12th day, in case 2 on the 7th day and in case 3 on the 8th day. When we assayed the serum samples for immunoenzymatic test, we found that the sera became positive some days earlier: on the 5th for case 1, already on the 1st day for the two others. In each of these three cases the positivity of the test corresponded to the presence of IgM class globulins since IgG detection remained negative as did the SN test. Our results could have some clinical interest concerning future rabies treatment and early diagnosis.

Antibody Formation↗

Zonal centrifuge purification of human rabies vaccine obtained on bovine fetal kidney cells. Biological results.

An inactivated human rabies vaccine prepared on bovine fetal kidney cells is concentrated and purified by zonal centrifugation. The peak of rabies particles is monitored by hemagglutination. Immunogenicity of the purified particles was evaluated by titration of specific antibodies from vaccinated animals. Protective activity of the vaccine was assayed on guinea pigs challenged with street rabies. Biological results were compared with those obtained with other tissue culture vaccines.

Animals↗

Comparative study on antibody determination by different methods in sera of persons vaccinated with HDCS-vaccine.

The comparative studies undertaken by 7 laboratories in 6 countries show that the calculation I.U.s did not as anticipated minimize but actually enhanced the variability of results of Rabies antibody estaminations in the sera of HDCS vaccines. The high biological variance in the method(s) may not have been considered by individual laboratories and any neglect of fundamental biostatistical laws, unfortunately, diminishes the theoretical advantage of using the "International Standard (I.S.)" as a "tertium comparationis". Perhaps the intrinsic variability of the I.S. should be re-evaluated and it is conceivable that a pure IgG fraction of Rabies antiserum would show less variability. Intralaboratory variation might be reduced by agreeing that only a geometric mean of the I.S., and not a single value obtained in an individual test, should be used for calculation of I.U.s. Application of the principles of biochemical and pharmacological methods, such as test-to-test control of the I.S. and its analytical variances might well enhance the reproducibility of the results. MNT, RFFIT, PRT and CFT were unable to detect antibodies in HDCS vaccinees until 7 days after the first vaccination. The establishment of methods for detecting early antibody requires further investigation.

Antibodies, Viral↗

[Evaluation of cellular immunity after rabies vaccination in man].

The peripheral lymphocytes of vaccinated men were stimulated by homologous antigen or its subunits (nucleocapsid and glycoprotein) or by some parent viruses (Mokola and Lagos). All subjects produced a high level of antibody. A difference was noted between the two types of immunity. A lack of cell-mediated immunity could explain the very few failures in Pasteur antirabies treatment.

Antibodies, Viral↗

[Rabies glycoprotein purification by isoelectric focusing (author's transl)].

A glycoprotein was extracted with Triton X100 from rabies virus grown in primary foetal bovine kidney cells. This glycoprotein was further purified by iso electro focusing and showed a major peak at pH 7,0 and a smaller peak at pH 4,6. Purified fractions were migrated on polyacrylamide gels and assayed for immunogenicity.

Glycoproteins↗

[Comparative study "in vitro" between rabies and rabies related viruses by the sensitized lymphocytes technique].

Rabbit lymphocytes obtained from animals previously exposed to rabies virus undergo a specific lymphoblastic transformation when incubated in vitro in the presence of either the complete virus or a nucleocapsid fraction. This type of in vitro transformation was observed by the Pasteur, Lagos, Mokola, Obodhiang viruses as well as the virus HEP in cells originally exposed only to the virus HEP. In additions to the morphological changes of lymphoblastic transformation, 3H-thymidine incorporation was stimulated about 21 to 67 fold in homologous system and about 6 to 39 in heterologous systems and unrelated with other virus system like influenza. These results suggest an immunological relationship between the classic rabies strains (HEP, Pasteur) and subgroup rhabdovirus (Lagos, Mokola, Obodhiang).

Animals↗