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Biomedical subjects

V Zachar

Publications and source records attributed to V Zachar.

At least 55 records · Page 3Linked to original sources
PubMed1989

Nucleotide sequence of HIV1-NDK: a highly cytopathic strain of the human immunodeficiency virus.

A highly cytopathic strain of HIV1, named HIV1-NDK, has been isolated from a Zaïrian patient affected with AIDS. This isolate is 10(4) times more cytopathic and infectious than the prototype. To correlate the high cytopathic properties of this strain with genetic variations, we have cloned and sequenced the genome of this isolate. The principal feature which could be drawn from the fine analysis of the HIV1-NDK sequence is that the variability is not clustered in one particular region but rather spread out all along the genome. Only minor differences seem to be responsible for the acute biological effect of HIV1-NDK.

Amino Acid Sequence↗
PubMed1989

Increased migration inhibition factor production by leukocytes of patients with herpes zoster given the leukocyte ultrafiltrate.

Using the direct leukocyte migration inhibition assay, the cell-mediated immune response was followed in together 47 patients suffering from herpes zoster. Of these, 19 persons were treated with partially purified and concentrated lysed leukocyte ultrafiltrate. Enhancement and/or earlier production of the leukocyte migration inhibition factor--in the presence of varicella-zoster virus antigen--was observed by leukocytes from patients given the ultrafiltrate on days 2-3 since the onset of the vesicular stage of the disease. Highly significant (alpha = 1%, P less than 0.01) differences in the migration inhibition values were observed between non-treated patients and patients given one dose of the ultrafiltrate during the days 3-12 after appearance of the first herpes zoster vesicles; on days 13-30 these values were not significant.

Adolescent↗
PubMed1988

A biometrical view on normal values of CD4 and CD8 lymphocyte counts in peripheral blood.

Statistical methods have been used to determine an optimal approach to the definition of the reference range for CD4 ("helper") and CD8 ("suppressor/cytotoxic") T cell numbers and the CD4/CD8 ratio in the peripheral blood. A graphical presentation of the absolute values for CD4 and CD8 for 85 healthy blood donors showed that a reference ellipse defined by fitting a gaussian distribution to logarithmically transformed data for absolute counts of CD4 and CD8 cells was superior to the fitting of an ellipse to untransformed data. Further analysis for another 147 subjects showed that the 95% tolerance prediction for the CD4/CD8 ratio in health could be stated with 95% confidence as 0.6 to 5.0. This approach allows clear definition of reference ranges for T cell tests in health and would also be applicable to results for patients with a disease such as HIV 1 infection in which a reference range for "well" patients exists and a change in the T cell ratio is of prognostic significance.

Biometry↗
PubMed1988

Varicella-zoster virus IgG antibodies during primoinfection in competent and transfer factor modulated immunocompromised host: comparison of three indirect assays.

Ten patients with acute leukaemia and next three with Hodgkin's or non-Hodgkin's lymphoma, suffering from varicella-zoster-virus (VZV) primoinfection, were given 1 to 2 doses of ultrafiltrate of the human leukocytes lysate (LLU) containing transfer factor (TF) activity (1 dose being equivalent to the product of 10(8) leukocytes). Only LLU administered to patients with acute lymphocytic leukaemia (ALL) at early phases of the illness (days 1 and 2) displayed a notable benefit on the clinical course of varicella. No influence upon the infection, on the other hand, was observed following LLU administration to subjects with lymphoma. The convalescent levels of IgG antibodies to VZV, as detected by indirect immunoperoxidase assay to membrane antigen (IPAMA), demonstrated no significant difference between infected competent and immunocompromised untreated and LLU treated individuals. The performance characteristics of IPAMA are compared with indirect immunofluorescence method (IFA) and non-competitive enzyme-linked immunosorbent assay (ELISA) on the same panel of specimens.

Antibodies, Viral↗
PubMed1987

Varicella-zoster virus IgM antibody fraction separated by minicolumn gel filtration in serodiagnosis of acute infection.

Gel filtration through Sephadex G-200 or Ultrogel AcA 34 minicolumns was applied to isolate IgM antibodies from sera of patients with varicella and herpes zoster (HZ). Serum samples were stained with Sudan III and Evan's Blue in order to monitor the separation process visually when running several columns at the same time. The presence of specific IgM antibodies was demonstrated by enzyme linked immunosorbent assay (ELISA). Rapid separation of stained sera by diffusion chromatography on minicolumns with successive determination of specific IgM antibodies in ELISA proved suitable for serological diagnosis of varicella, whereas the significance of IgM-specific antibody response in HZ seems uncertain.

Acute Disease↗
PubMed1986

Early intrathecal production of specific IgM and IgG antibodies and alpha-interferon in herpes simplex virus encephalitis.

A complex approach was used in order to establish non-invasively the aetiology in three cases of encephalitis presumptively caused by herpes simplex virus (HSV). As indicative of brain HSV infection was considered the lowered serum to cerebrospinal fluid specific antibody ratio, which also assessed the humoral immune response within the CNS. For this purpose, during ongoing brain tissue infection, the early intrathecal (ITH) production of IgG and IgM antibodies was analysed by a differential enzyme-linked immunosorbent assay (ELISA) along with changing levels of complement-fixing (CF) antibodies in the serum and cerebrospinal fluid (CSF). Antiviral antibody (AA) response was markedly preceded by the appearance of alpha-interferon (IFN) in the serum and CSF. From the CNS biopsy and autopsy specimens one HSV-1 and one HSV-2 strain were recovered.

Adolescent↗
PubMed1986

Focus assay for varicella-zoster virus in human embryo cells stained with immunoperoxidase method.

Rapid titration of varicella-zoster virus (VZV) in human embryonic fibroblasts (HEF) based on staining of virus-infected cells by indirect immunoperoxidase technique (IPA) is described. Cell monolayers were grown in wells of plastic plates (two different diameters). Foci of virus-infected cells as revealed by IPA could be counted either 48 hr post-infection, if cell-associated virus (VZV infected cells) was used as inoculum, or 72 hr p. i. if cell-free virus was used. A linear relationship was observed between virus dilution and number of foci. The first virus was detected 12 hr p. i., the highest titre at 36 hr, when cytopathic effect (CPE) involved about 50% of the monolayer.

Cells, Cultured↗