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Biomedical subjects

R Benda

Publications and source records attributed to R Benda.

At least 19 recordsLinked to original sources
PubMed1989

Some immunological characteristics of subjects suffering from frequent herpes simplex virus recrudescences.

Some parameters of specific and non-specific immunity were tested in a group of 44 subjects suffering from frequent herpes simplex type 1 (HSV-1) or herpes simplex type 2 (HSV-2) recrudescences. The tests performed included determinations of (i) HSV complement-independent and complement-dependent neutralizing antibodies, (ii) antibodies to glycoprotein C of HSV-1 and glycoprotein G of HSV-2, (iii) antibodies to viral capsid and early antigens of Epstein-Barr virus, (iv) antibodies to tetanus toxoid, (v) serum levels of IgM, IgG, IgA, transferrin, prealbumin and C'3 and C'4 components of complement, (vi) active and total T lymphocytes, (vii) phagocyting activity of polymorphonuclear neutrophils, eosinophils and mononuclear cells, (viii) skin reactivity to tuberculin, toxoplasmin, candidin, tetanus and diphtheria toxoids. In the patients the following deviations from the control groups were noted: (i) Antibody levels to homotypic but not to heterotypic HSV were enhanced, (ii) serum IgM levels were elevated, (iii) percentages and numbers of active and total T lymphocytes were decreased, (iv) phagocyting activity of neutrophils was depressed but that of eosinophils was increased.

Adolescent↗
PubMed1989

Monoclonal antibodies against hepatitis B virus surface antigen: preparation and characterization.

Hybridomas secreting HBsAg antibodies were obtained by fusing murine myeloma cell line P3-X63-Ag8 to spleen cells of BALB/c mice sensitized with HBsAg. The surface antigen used for immunization of mice was prepared by purification from pooled human plasma specimens. Resulting monoclonal antibodies were detected by the SPRIA method. Clones producing highest anti-HBs titres were used to prepare mouse ascitic fluids. Monoclonal antibodies in ascitic fluid reached a titre of 10(6) to 10(7) at a protein concentration of 1 mg per ml. Two of the prepared monoclonal antibodies, HBS-01 and HBS-02, both belonging to IgG1 subclass of immunoglobulins, were selected for further study in order to assess their potential useability in the commercial ELISA kit. The pI values for HBS-01 ranged from 6.60 to 6.85, for HBS-02 from 5.6 to 6.1. In solid phase ELISA test the use of HBS-01 antibody improved accuracy of the assay by increasing its detection sensitivity for HBsAg subtypes adw and ayw in the reference serum; this sensitivity was evidently much better than that seen with the commercially available rabbit polyclonal anti-HBsAg antibody. The monoclonal antibody HBS-01 is specific to the determinant "a", which makes it suitable for use in ELISA test aimed at HBsAg detection. The antibody HBS-02 showed a markedly better reaction with HBsAg subtype adw than subtype ayw and can thus be used with advantage for their discrimination.

Animals↗
PubMed1988

Placebo-controlled study with subunit herpes simplex virus vaccine in subjects suffering from frequent herpetic recurrences.

The safety and efficacy of a subunit herpes simplex virus (HSV) type 1 vaccine were tested in a small-scale double-blind trial carried out in a group of 42 volunteers suffering from frequent recurrences of herpetic lesions. The patients were paired according to sex, age, type of virus isolated, previous history of the disease and some non-specific immunological markers. One member of each pair received repeated doses of HSV vaccine, the other a placebo. Clinical reactions were mild. Antibody responses following the vaccination were generally low and were almost entirely limited to subjects suffering from HSV-2 lesions. A majority of the patients exhibited improvement of their condition during the postvaccination period. These improvements were, however, nearly equally distributed between the vaccine and placebo groups.

Adolescent↗
PubMed1988

A technology of preparing hepatitis A virus (HAV) from human stools.

Two-step differential centrifugation through 40% and 20% sucrose of 20% water extracts of HAV-positive stools yielded specific defined antigens for hepatitis A serological diagnosis by 3rd-generation methods. The antigens would be suitable also for other purposes. Products of comparable quality were obtained from HAV-positive stools yielding different amounts of virus. Optimal were incubation-period stools, where the loss in HAV yield was minimal; these preparations displayed the highest antigenic capacity and could be diluted up to 150 fold for serological reactions. Results obtained in extensive preliminary experiments, outlined in the Discussion, corroborated the advantages and efficiency of the proposed technology.

Antigens, Viral↗
PubMed1986

Effect of maternal varicella-zoster virus infection on the outcome of pregnancy and the analysis of transplacental virus transmission.

In result of 20 pregnancies complicated by varicella 11 healthy and 6 defective offspring were born, 2 pregnancies were aborted by the physician and one pregnancy terminated by stillbirth of 3 siblings. Laboratory investigation of 16 pregnancies has shown that transplacental transfer of varicella-zoster (VZ) virus did not occur in 13 cases (81.2%). In 3 cases transplacental transmission of VZ virus was not inconsistent with the laboratory results, clinical course, and epidemiological analysis. Intrauterine VZ virus infection was suggested in one typical case of congenital varicella syndrome and in one healthy newborn according to the presence of high serum antibody levels at the time of maternal antibody decline. In the third case, VZ virus antigen was detected by indirect immunofluorescence in the foetal skin tissue after medical abortion.

Antibodies, Viral↗
PubMed1981

Unusual electron microscopy findings in liver biopsies from patients with viral hepatitis B.

Electron microscopy of 57 needle biopsies from livers of 55 patients with chronic hepatitis, mostly of type B, revealed, in addition to typical hepatitis B virus nucleocapsids in 34 cases, also atypical intranuclear inclusions in 9 biopsies. These inclusions consisted of electron-dense particles similar in size to hepatitis B virus nucleocapsids. The possibility of an involvement of a hepatitis non-A non-B virus is discussed.

Adult↗
PubMed1981

Use of hyperimmune mouse ascitic fluids for arbovirus differentiation by indirect immunofluorescence and conventional serology.

The cross-reactivity of 22 arbovirus species (alphaviruses; tick- and mosquito-borne flaviviruses; and selected bunyaviruses) was tested with monovalent immune mouse ascitic fluids by indirect immunofluorescence (IIF) in comparison with classical serological reactions (virus neutralization -- VN; haemagglutination inhibition -- HI; and complement fixation -- CF -- reactions). Known relationships within the virus groups studied were confirmed. As to the differentiation limits, the VN test was followed by IIF. Evaluation of the ratio of heterologous to homologous antibody activities showed that with the exception of antigenically closely related arboviruses (Western equine encephalomyelitis -- Sindbis; Japanese encephalitis -- Murray Valley encephalitis; dengue viruses; California -- Tahyna), most arboviruses within the antigenic complexes tested could be relatively reliably differentiated by IIF.

Alphavirus↗
PubMed1978

CV-1 monkey kidney cell line -- a highly susceptible substrate for diagnosis and study of arboviruses.

The CV-1 cell line, derived from Cercopithecus aethiops monkey kidneys, acquired in the course of serial passaging an epitheloid morphology and heteroploid karyotype. As compared with Vero and GMK cell lines, the CV-1 line proved to be more susceptible to a broad spectrum of arboviruses belonging to the families Togaviridae and Bunyaviridae. Most of them reached high titres and were markedly cytopathic in CV-1 cells so that all tests based on the cytopathic effect could be carried out. The CV-1 cell line can thus be recommended as an extra-ordinarily suitable substrate for the diagnosis and study of arboviruses.

Animals↗
PubMed1978

Cultivation of Tuleniy virus (strain Murman) in vitro.

In vitro culturability of Murman strain of Tuleniy flavivirus isolated recently in the northern regions of the USSR was studied. Stable PS pig kidney line was found suitable as a primary sensitive cell substrate for the isolation, proliferation and serial propagation of the virus. The pronounced pathogenicity of the virus to PS cells permits the testing of its infective activity comparable with i.c. titrations on mice, VNT in vitro and the plaquing technique. PS line is suitable for the demonstration and identification of the virus antigen and/or for the study of reproduction of the virus on cellular level using the technique of immunofluorescence.

Animals↗