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Biomedical subjects

D Dworniak

Publications and source records attributed to D Dworniak.

At least 19 recordsLinked to original sources
PubMed2001

[The use of flow cytometry for the determination of the hepatitis B virus pre-S1 envelop protein binding by human peripheral blood lymphocytes in vitro in the course of recovery].

The course of hepatitis B virus (HBV) infection depends on the host immune response to various antigens of the virus, including hepatitis B surface antigen (HbsAg), which is present on the envelope of HBV and which contains Pre-S1, Pre-S2 and S proteins. The peripheral blood lymphocytes (PBL) from patients with chronic hepatitis B infection (CHB) and patients acutely infected with HBV and recovered completely (convalescents) were studied for detecting of Pre-S1 antigen binding. We used a cytometric method for measurement of the binding of fluorescein labeled Pre-S1 antigen (FITC/Pre-S1) to the PBL. The binding of FITC/Pre-S1 was determined on resting lymphocytes and on lymphocytes cultured in vitro for 5 days in the presence of Pre-S1 and phytohaemagglutinin-P (PHA-P). The expression of CD3 and CD19 molecules on the surface of PBLs simultaneously with the expression of FITC/Pre-S1 was also analysed using flow cytometry. We found that the Pre-S1 binding significantly depends on the state of the activation of lymphocytes. Specific stimulation of the convalescent lymphocytes with Pre-S1 resulted in an increase in the percentage of the FITC/Pre-S1 binding cells in relation to the unstimulated cultured and resting cells as well as to the cells from CHB patients. We suggest that flow cytometric measurement of Pre-S1 binding by lymphocytes may be useful indicator of the disease activity.

Convalescence↗
PubMed1999

[Sources of infections and genotypes of hepatitis C virus in children].

The aim of the study was to analyse possible sources of HCV infection as well as to study their relation to specific HCV genotype. The study comprised 60 children with chronic hepatitis C age from 3 to 15 years. In 36.6% of patients, the probable risk factors were surgical interventions or injures; in 60% prior hospitalisation in conservative wards. Surgery was a risk factor in 59% of cases of infection with genotype 1a and in 41%--with genotype 1b. Hospitalisation conservative was the risk factor for the infection in 47% and 50% of cases, respectively.

Adolescent↗
PubMed1996

Oxidative burst response of neutrophils primed with PreS1 antigen of hepatitis B virus in patients with chronic hepatitis B and convalescents.

The pathogenesis of liver damage in the course of hepatitis B virus (HBV) infection depends on the host's specific and non-specific immune response to various viral antigens. The role of polymorphonuclear neutrophils (PMN) in the natural immune reaction and during secondary microbial infections is well documented. Increased free radical production is associated with many pathological conditions such as shock, ischaemia or chronic inflammatory diseases. We studied the oxidative metabolism of neutrophils in patients with chronic HBV and after recovery (convalescents). The effect of the PreS1 fragment of HBV antigen on some neutrophil functions in vitro was also examined. There were significant differences in the values of spontaneous and stimulated oxidative burst of neutrophils, measured using luminol-chemiluminescence, in patients with HBV when compared with the convalescents. PreS1 antigen did not by itself induce the respiratory burst in human neutrophils but it potentiated their response to a second stimulus. Hence we observed a priming of neutrophils, for an enhanced respiratory burst, by PreS1 antigen.

Adult↗
PubMed1995

Effect of pre-S1 antigen on human lymphocyte proliferative responses.

The peripheral blood mononuclear cells (PBMCs) from patients acutely infected with HBV and recovered completely (n = 20), patients with chronic hepatitis B infection (CHB)- (n = 10) and HBsAg-positive carriers (n = 9) and healthy individuals (n = 8) were studied for their in vitro proliferative response to a synthetic pre-S1(20-49)x4 antigen. PBMCs from convalescents showed significant proliferative response in the presence of synthetic pre-S1 antigen. PBMCs from CHB- and HBsAg-positive exhibited reduced proliferative response not only to Pre-S1 antigen but also to nonspecific mitogens. This study suggests that the immune recognition of pre-S1 antigen and response of PBMCs to the pre-S1 antigen may be an important part of the normal human response to HBV infection. Failure to clear the HBV infection with development of the chronic carrier state may be caused by the lack of an efficient pre-S1 antigen-specific response.

Adult↗
PubMed1991

Effect of thymic extract on allogeneic MLR and mitogen-induced responses in patients with chronic active hepatitis B.

Cell-mediated immune reactions are involved in the development of chronic active hepatitis (CAH-B). The present studies confirm that lymphocyte from patients with CAH-B have a decreased allogeneic mixed lymphocyte reaction (allo-MLR) and mitogen-induced responses. These abnormalities probably play a role in the immunological dysfunctions underlying chronic liver diseases. Twenty one patients with biopsy-proven CAH-B and a significantly lowered CD4:CD8 cell number ratio were treated with thymic extract (Thymomodulin-TFX) for 6 months. The results of immunological, serological and biochemical findings indicate that this preparation has an immunoregulatory action and produces beneficial clinical effect in patients with CAH-B.

Adult↗
PubMed1991

The effect of long-term thymosine factor x/TFx/treatment on T lymphocyte subpopulations and peripheral blood mononuclear cell cytotoxicity in chronic active hepatitis B.

Peripheral blood mononuclear cells (PBMC) cytotoxic activity, percentage of natural killer (NK) cells and T lymphocyte subpopulations in PBMC of 24 patients suffering from chronic active hepatitis B (CAH-B) have been studied. In comparison with healthy subjects CAH-B patients had significantly enhanced both lymphocyte T suppressor (Ts) and NK cell number. Thirteen CAH-B patients with higher Ts number and low lymphocyte T helper/T suppressor ratio (Th/Ts) were subjected to immunostimulation by thymosine factor x (TFx) treatment. After 1 year of TFx treatment all the CAH-B patients improved clinically, the Th/Ts ratio was brought back to normal and 80 per cent of HBe Ag carriers seroconverted to anti-HBe. After one year of TFx administration no significant changes were observed in PBMC cytotoxicity and NK cell number. TFx appears to be a very effective therapeutic agent in some forms of CAH-B. The obtained results show that TFx normalises biochemical parameters of liver lesion and Th/Ts ratio without any effect on NK cell activity in CAH-B patients.

Adolescent↗
PubMed1991

Treatment with thymic extract TFX for chronic active hepatitis B.

Eighteen patients with biopsy-proven chronic active hepatitis B (CAHB) and a significantly lowered CD4+/CD8+ cell number ratio were treated with thymic factor X (TFX): group I (n = 12) - for 12 months, group II (n = 6) for 6 months. As early as 14 days after starting the treatment a lowering of CD8+ cell numbers with a rise in CD4+/CD8+ cell number ratio were found. These changes continued to progress during the next months and were accompanied by decreased in NK cell numbers with enhancement of NK cell activity. Normalization of the biochemical and immunological parameters occurred after 5-6 months of the treatment. In both groups of patients seroconversion in the HBe system was observed after 9-12 months of the treatment. After two years complete clinical remission persists with normal biochemical and immunological findings and without reversion in the HBe system. The results seem to indicate that TFX has an immunostimulatory action and exerts beneficial effects on the course of CAHB.

Adolescent↗
PubMed1989

Increase in antipyrine clearance in workers exposed to phenol and toluene in the petrochemical industry.

In 90 workers of the petrochemical industry occupationally exposed to a mixture of petroleum derivatives, including 60 persons exposed mainly to phenol and 30 to toluene, the metabolic activity of the liver was examined using the antipyrine test. In both groups of subjects, an increase of antipyrine clearance in saliva was observed. Occupational exposure to lipophylic derivatives of petroleum seems to induce the function of liver microsomal enzymes.

Adult↗
PubMed1989

T lymphocyte subpopulations in patients with chronic active hepatitis B virus infection characterized by monoclonal antibodies.

Peripheral blood T lymphocytes and T cell subsets were analyzed in 19 patients with chronic active hepatitis B virus infection. The T cell subpopulations were defined by indirect immuno-fluorescence using monoclonal antibodies, and additionally, natural killer cell activity against K 562 human erythroleukemic cell has also been defined. All investigated patients have possessed nearly identical clinical and biochemical signs of disease, but on the basis of T lymphocyte subpopulations they could be divided into two groups: low CD4/CD8 ratio group and normal or high CD4/CD8 ratio group. Mechanism responsible for such differences remains hypothetical but it seems reasonable to propose different protocol for immunomodulatory treatment of patients in both groups.

Adolescent↗
PubMed1988

[Antipyrine test in petrochemical industry workers exposed to benzene].

Forty petrochemical industry workers occupationally exposed to benzene levels within TLVs (30 mg.m-3) had their hepatic microsomal enzyme function quantitatively assessed by the antipyrine test. The clearance (C1AP) and half life (P1/2) of antipyrine in the saliva were determined. The benzene-exposed workers exhibited increased C1AP and decreased P1/2, as compared to 20 control subjects. The occupational exposure to benzene at the concentrations exceeding 30 mg.m-3 seems to induce the microsomal enzyme function of the liver.

Adult↗