[Expert research on sera yielding false-positive results for HIV antibodies during screening]. / Ekspertnye issledovaniia syvorotok, daiushchikh lozhnopolozhitel'nye rezul'taty na antitela k VICh pri skrininge.

The significance of different serological methods and assay systems for the verification of false positive cases of HIV infection has been analyzed on the basis of materials obtained in arbitration studies. As demonstrated by this analysis, the use of such highly specific and sensitive systems as Huma-Lab, Enzygnost, Serodia and Erythrorecombinant has made it possible to obtain a reliable result as early as at the first stage of expert diagnosis in the enzyme immunoassay and the agglutination test. The methods of radioimmunoprecipitation and indirect immunofluorescence have permitted a more precise differentiation of doubtful results than that achieved by immune blotting.

[The isolation of HIV from children with the initial signs of an HIV infection and from symptom-free carriers]. / Vydelenie VICh ot detei s nachal'nymi priznakami VICh-infektsii i bessimptomnykh nositelei.

A high rate of HIV carrier state was observed in seropositive children with early symptoms of HIV infection. The virus was also isolated from 2 seropositive adults (mothers) showing no clinical manifestations. The intervals of virus manifestation in culture varied from 6 to 30 days with maximal frequency of detection in the 2nd week. Different modifications of the procedure for HIV isolation were assayed, and it was shown that the efficacy of isolation (shortening of the period of virus detectability and increase in the number of the antigen-containing cells) could be improved by the addition to the culture of the Jurkat-tat III line expressing the product of the tat gene important for virus reproduction.

[3 cases of viral carriage detected during screening for HIV antibodies]. / Tri sluchaia virusonositel'stva, vyiavlennye pri skrininge na antitela k VICh.

The results of screening more than 23,000 serum samples from persons belonging to risk groups, as well as those not belonging to such groups, in Moscow, Vilnius and Klaipeda are presented. Screening was carried out with the use of an assay system manufactured by the Scientific and Industrial Amalgamation "Antigen" (USSR). In this screening 3 HIV carriers were detected; of these, 2 were foreign students from two African countries.

[The development and use of an immunoenzyme test system for detecting and the species identification of the monkey pox virus]. / Razrabotka i primenenie test-sistemy IFA dlia vyiavleniia i vidovoi identifikatsii virusa ospy obez'ian.

An enzyme immunoassay (EIA) system for the species-specific diagnosis of monkeypox, based on the use of monoclonal antibodies (McAb) to monkeypox virus, has been developed. Immunoglobulins, isolated from McAb-containing cultural and immune ascitic fluids, have been conjugated with horse-radish peroxidase and used as detector antibodies. For immunosorption, rabbit polyclonal antibodies to the vaccine virus have been used. The specificity and sensitivity of the EIA system thus obtained have been tested on animals and humans having monkeypox and confirmed by traditional diagnostic methods (the isolation of the virus on chick embryo chorioallantoic membranes and in cell culture).

[Stability of the main components of an EIA test system for the serodiagnosis of HIV infection]. / O stabil'nosti osnovnykh komponentov test-sistemy IFA dlia serodiagnostiki VICh-infektsii.

The stability of two most important components of the EIA test system for diagnosis of HIV infection, an immunosorbent (HIV antigen adsorbed on polystyrene plates) and antispecies peroxidase conjugate, was studied. The possibility to prolong the shelf life of the test system for at least up to 6 months was demonstrated. At the same time, it is proposed to supplement the existing methods of production control with the conjugate thermostability test developed by the authors who believe that this will allow to exclude conjugates with insufficient stability from the test system kit.

Smallpox diagnosed 400 years later: results of skin lesions examination of 16th century Italian mummy.

Results are presented on virological examination conducted on WHO request of a Naples infant mummy with smallpox-like lesions. Electron microscopy of lesions confirmed the findings of Italian researchers: well-preserved virus-like structures, whose size and morphology were identical to those of orthopoxviruses have been revealed. It was shown that the virus in mummy skin had lost its viability. Viral antigenic activity could not be detected in EIA or RPHA, nor was determined its DNA in the test of DNA molecular hybridization.

[Detection and quantitative determination of antigen to the human immunodeficiency virus during development of a test-system for the serodiagnosis of AIDS]. / Vyiavlenie i kolichestvennoe opredelenie antigena virusa immunodefitsita cheloveka v protsesse polucheniia test-sistemy dlia serodiagnostiki SPID.

One of the variants of IFA using a conjugate on the basis of anti-HIV-IgG was used for control of the content of human immunodeficiency virus (HIV) antigen at different stages of production of a test system for serodiagnosis of AIDS. This method permits HIV antigen quantitation in virus lysates, its nonpurified concentrates, and in native culture fluid in titres from 2000 to 60,000 and from less than 27 to greater than 729, respectively. In most cases, high titres of antigen in the liquid fraction of the culture corresponded to high values of the antigen-containing cells on the basis of immunofluorescence data and signs of intensive HIV production in electron microscopic culture control. The authors developed a method allowing to determine the antigen titre in the study material using only one dilution (1:9) of it in IFA technique.

Monkey pox in humans: current results.

The presented studies were performed at the WHO Collaboration Center for Smallpox in Moscow in the framework of the WHO monkey pox project. The authors recommend improved methods for rapid detection of orthopoxvirus antigen, namely passive haemagglutination (PHA) using dried stable red blood cells and ELISA in order to provide more rapid and efficient laboratory diagnosis under field conditions. Independent serologic diagnosis of monkey pox by ELISA-adsorption (ELISA-A) was proved of value for epidemiological studies and for detection of inapparent infections. The application range of the latter technique and its limitations were also determined.

Monoclonal antibodies to monkey pox virus: preparation and application.

Two fusion experiments with NSO myeloma cells yielded 30 hybrid cell lines which continuously and actively secreted monoclonal antibodies (MoAb) to monkey pox virus. Eight lines appeared to produce antibodies to specific antigenic determinants. The isotype and serologic reactivity of MoAb to monkey pox virus was characterized and the karyotype of several hybridomas determined. An enzyme labelled conjugate has been prepared from MoAb selectively reacting with monkey pox virus. This conjugate allowed the identification of monkey pox virus in the materials from patients. It also helped to determine that an orthopoxvirus isolated from wild squirrel in the Republic of Zaire was monkey pox virus.

[Increase in the specificity of immunoenzyme analysis by using a monoclonal antibody-based conjugate]. / Povyshenie spetsifichnosti immunofermentnogo analiza za schet ispol'zovaniia kon"iugata na osnove monoklonal'nykh antitel.

Examinations by EIA of laboratory cultures of various orthopoxviruses and specimens from human-monkey pox cases demonstrated the advantages of a monoclonal preparation over the peroxidase polyclonal conjugate prepared from hyperimmune vaccinia antiserum.

Clustered cases of paravaccinia in milkers.

Clustered cases of a disease in men and cows firstly diagnosed as cowpox has been described. Clinical manifestation, epidemiology and laboratory diagnostics are presented. Virological and serological investigations of the specimens taken from sick persons and animals proved paravaccinia virus (genus Parapoxvirus) to be etiological agent of the illness. Cowpox virus (genus Orthopoxvirus) greatly differs from the latter by phenotypical markers. The disease in humans is called Milkers' modules, in cows--pseudocowpox. The disease is mostly benign and this is a reason why it does not attract sufficient attention of health personnel. Nevertheless this infection can cause a certain economical loss.

New outlook on the biology of cowpox virus.

Analysis of cowpox outbreaks revealed an extremely wide range of virus pathogenicity including 9 orders of mammals. Recent serological and virological data support the hypothesis that wild rodents may be a natural reservoir of cowpox virus. Cowpox infection of humans occurring without any contact with infected cattle (registered in the U. K. and Poland) is especially interesting for medical and veterinary virology. Surveillance seems justified of the possible virus dissemination beyond its natural reservoir resulting in further infection of man and animals.