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Biomedical subjects

P Atanasiu

Publications and source records attributed to P Atanasiu.

At least 19 recordsLinked to original sources
PubMed1982

[Role of interferon in rabies immunity].

Cell cultured rabies vaccines, usually induce a good production of interferon. A comparative study shows that vaccines from primary explantation cell cultures are better interferon inducers. Taking into account the importance of this induction in rabies vaccination, a study showing the role of leucocyte interferon (alpha-type) is achieved. Results show that leucocyte interferon (originating from the Red Cross, Osaka, Japan and Institut Pasteur Production, Paris) inhibits the formation of fluorescent inclusions and the production of infectious particles in MRC5 cells inoculated with a fixed rabies strain. On the other hand modification of the thymus weight was studied following injections of interferon inducer vaccines and after challenge with a street rabies virus.

Animals↗
PubMed1982

[Evaluation of an experimental rabies vaccine by the oral and intestinal route with inactivated vaccines, concentrated or non-concentrated].

Application of beta-propiolactone inactivated rabies vaccine prepared in bovine embryo kidney cells, concentrated or non concentrated, by intestinal or oral route resulted in antibody production in rats and cats. 80-100% of vaccinated rats were protected against challenge with street rabies virus. The same vaccines (lyophilized in gelatin capsules) stimulated antibody production in more than 50% (5/8) cats which received the vaccine by the oral route.

Administration, Oral↗
PubMed1982

Cytotoxicity reactions against target cells infected with rabies virus.

Some aspects of the cytotoxicity reactions were studied in the rabies system. The antibody-dependent complement cytotoxicity (ADC), the cellular cytotoxicity (CC), and the antibody-dependent cellular cytotoxicity (ADCC) are shown, being the cytotoxic effect as evidenced by the 51Cr released from the cells infected with the Pasteur strain of rabies virus. Some parameters such as time of cellular infection, the amount of infected cells, the concentration of complement, and the incubation time of the ADC reaction, which help to increase the performance of this reaction, are discussed. The detection and the level of the cellular response against the Pasteur strain of rabies virus in immunized mice is shown. Evidence is presented that in the ADCC test, specific human antibodies and non-immune human lymphoid cells are able to mediate in vitro lysis of cells infected with rabies virus. A comparison of the ADCC test with serum neutralization and immunoenzymatic tests is shown.

Animals↗
PubMed1981

Evaluation and comparative studies of inactivated rabies vaccines obtained in the heterologous diploid and polyploid cells (HAK, BHK and VERO).

This study is concerned with the following characteristics of the vaccines: 1.) protecting power, 2.) rabies antigens and 3.) major polypeptide components. This study was performed on supernatants of tissue cultures and on concentrated and purified vaccines. Moreover, some cellular and serum contaminants, especially the proteins produced by BHK cells, as well as minor rabies proteins, were analysed in the viral solutions. Thus, it appears that all three types of vaccines have a similar protecting power (Number of 50% protective doses/micrograms viral protein).

Animals↗
PubMed1980

[Molecular study in polyacrylamide gel of polypeptides of several strains of rabies virus].

Comparative study of structural polypeptides of five rabies virus strains (serotype 1) and one serotype IV, demonstrates difference in molecular weight of the envelope polypeptides M1 and G of all strains. There is little difference between the structural polypeptides N, M2 and probably L. Some purified strains have been treated by trypsine to localize the position of polypeptides. There was no difference between the four major polypeptides of complete and defective virus. Pasteur strain cultivated on different cells shows very little difference in molecular weight of the four major polypeptides.

Electrophoresis, Polyacrylamide Gel↗
PubMed1980

Use of an enzyme immunoassay with protein A for rabies antigen and antibody determination.

The rabies antigen quantitation reported here is based on the principle of an enzyme immuno micro assay (EIA) using antigen coated polystyrene microtiter plates. In a first step antibodies of known specificity are partially blocked by the antigen to be titrated; in a second step the free remaining antibodies are determined by EIA. Antirabies vaccines, purified virus or rabies glycoprotein were assayed by that micro-method in comparison with the double neutralization test in tissue culture. Moreover, we report results obtained by EIA on the rate of antigen bonding to a solid carrier in order to prepare immunoadsorbents and the usefulness of EIA to monitor specific immunoglobulin elution.

Antibodies, Viral↗
PubMed1980

Concentration and purification of human rabies vaccines : results.

Concentration of two types of rabies tissue culture vaccine has been realized with Amicon hollow fibers. The coefficient of purification obtained on Sepharose 6B chromatography is 2,3 to 4,6 with a recuperation of 25% to 30% of the haemagglutination power for one of the vaccines. The control of glycoprotein contents has been realized by means of classical technics as well as the rapid immunoenzymatic test. (I.E.T.).

Chromatography, Gel↗
PubMed1979

[Glycosylation and isoelectric properties of complete and defective rabies viruses (author's transl)].

From a structural point of view an essential distinction between complete and defective rabies viruses is difference in size. In addition, isoelectric properties differ. The complete virus has an isoelectric point approaching neutrality, whereas the defective virus focuses between pH 3-4.7. The isoelectric points of the glycoprotein from complete and defective viruses differ in a corresponding fashion. The Pasteur virus cultivated on BHK21C13 cells, contains glycoproteins, the glycopeptides of which have a structure containing the following five monosaccharides: sialic acid, D-galactose, (N-acetyl)D-glucosamine, D-mannose and L-fucose. The glycosylation of the glycoproteins is different, at least in so far as the relative sialic acid/glucosamine ratio is concerned.

Acetylglucosamine↗
PubMed1979

IgM and IgG antibody responses in rabies encephalitis.

Immunological survey of 3 patients with proved rabies encephalitis shows three interesting facts. 1) An IgM local synthesis, sometimes proportionally higher than IgG local synthesis, is observed in 8 CSF (among 13 investigated) and detected early, during the first week of the disease for 2 patients. 2) A relative poor IgG response is noted; this response is absent in one and decreasing in the 2 others patients despite their progressive aggravation. 3) A very little elevation of blood nucleic antibodies is detected in 5 CSF only. This very poor synthesis of antinucleic IgG contrast with their common increase in viral encephalitis. Thus, a viral immunosuppression may be discussed in rabies encephalitis, which may contribute to the lethal prognosis.

Encephalitis↗
PubMed1978

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

Techniques usually employed for the detection of rabies' antibodies are costly, time consuming, and sometimes fail to detect early antibodies. The introduction of immunoenzymatic techniques in the serology of viral disease represents a new and important advance. We therefore adapted this technique to the detection of rabies antibodies. We have found that the sera from rabies patients who had not received antirabies treatment do not show seroneutralizing antibodies until several days after the onset of symptoms. However, antibodies can be detected some days earlier by the immunoenzymatic method in the same samples. Furthermore, the immunoenzymatic test was applied to the detection of both the IgM or the IgG class of antirabies antibodies using an antihuman Ig-or antihuman IgG-peroxydase conjugate.

Antibodies, Viral↗
PubMed1978

Inhibition of rabies virus in vitro by the ammonium-5-tungsto-2-antimoniate.

In vitro multiplication of rabies virus was inhibited by a condensed mineral ion, ammonium-5-tungsto-2-antimoniate (HPA 23). The inhibitory effect was evaluated by two different methods, plaque reduction and one step virus growth. Plaquing showed 50% inhibition with 4.5 microgram/ml of HPA 23 and complete inhibition with 12.5 microgram/ml. A reduction of two logs in virus yield was obtained in BHK21C13S cells in suspension treated with 50 microgram/ml of HPA 23. Inhibition also occurred when treatment with HPA 23 was started 18 to 24 h after infection in the plaque assay but no effect was seen when HPA 23 was added 48 h after virus inoculation. All these inhibitory effects of HPA 23 on rabies virus multiplication were observed at non cytotoxic doses. Therefore HPA 23 contrasts with other antiviral drugs which do not inhibit rabies virus multiplication without affecting the viability of cells.

Antimony↗
PubMed1978

Comparison studies on potency tests for rabies vaccines.

Eleven laboratories from eight countries and four continents took part in a collaborative study to evaluate experimental procedures to be used in selecting the new standard reference rabies vaccine prepared in human diploid cell cultures. The following procedures were used : (a) the NIH potency test in mice, (b) the antibody binding technique (by either mouse inoculation or the tissue culture method), (c) virus-neutralizing antibody levels in mice used for the NIH test, and (d) antibody induction in human volunteers treated with vaccine alone and in combination with human rabies gamma globulin. The four methods used for determination of rabies antibodies were mouse inoculation, rapid fluorescent focus inhibition, plaque reduction and complement fixation techniques. All results were expressed in International Units as compared to the standard WHO serum and vaccine preparations. In general, a close correlation was noted in results from different laboratories, and it was recommended that the future rabies standard vaccine should be evaluated by three testing procedures, the NIH test, the antibody-binding technique, and antibody levels in mice used for the NIH test.

Animals↗
PubMed1978

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

The comparative studies undertaken by 7 laboratories in 6 countries show that the calculation of I.U.'s did not, as anticipated, minimize but actually enhanced the variability of results of rabies antibody estimations in the sera of HDCS vaccinees. 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.

Analysis of Variance↗