Biomedical subjects
Publications and source records attributed to K Zeman.
The effect of epinephrine and propranolol administration in vivo on autologous mixed lymphocyte reaction (AMLR) was investigated. AMLR inhibition by epinephrine and potentiation of AMLR after propranolol injection was found. Presumable mechanisms of these changes in the light of beta-receptor agonist and antagonist are discussed.
The effect of a single intravenous dose of calcium channel blocking agent verapamil (VER) on immune parameters in humans remains uncertain. In this study the effects of VER on lymphocyte subpopulations, interleukin 1 (IL-1) and 2 (IL-2) production in vitro, autologous mixed lymphocyte reaction (AMLR), IL-2 receptor expression (Tac positive cells) and natural killer (NK) cell activity were assessed. The investigations were undertaken on 12 hospitalized men, aged 19-23 years, with small abdominal complaints. None of them had active duodenal ulcer disease, while in the remaining no signs of organic disease were found. VER was given intravenously in a dose of 0.15 mg/kg and examinations were performed on peripheral blood mononuclear cells (PBL) drawn before and 30 and 150 min following VER injection. The single VER dose induced a significant, but transient increase in T, T helper, T suppressor lymphocytes and monocytes, and decrease in IL-1 and IL-2 generation as well as diminished Tac antigen expression. These data provide evidence that calcium channel blockers may transiently disturb immunoregulation.
The aim of this study was to evaluate immunological, hematological and biochemical parameters in subjects chronically exposed to inhaled formaldehyde (F), phenol (Ph) and isomers of organic chlorohydrocarbons (Chc) released from Ksylamit. Twenty-two office workers had been exposed for 6 months to vapors of Ksylamit, used for protection of felt plates inside the office building. The concentration of Ksylamit vapor was measured at the end of the 6-month period and the level of Ph and F in the air inside the building was 1.3 mg/m3 and 0.8 mg/m3, respectively. Most of the workers had ailments due to the irritant effect of inhaled Ksylamit, but no remarkable increase in morbidity was found during the 6 months of exposure and in a 3-year follow-up. Morphological parameters of blood and the number of natural killer (NK) cells in the group of exposed subjects were within the range observed in healthy subjects matched for age and sex. The number of T-lymphocytes and NK cell cytotoxicity were significantly decreased. Phytohemagglutinin (PHA)- and alloantigen-induced lymphocyte proliferation was diminished. Some biochemical parameters suggested liver damage, although these parameters did not correlate with the levels of Ph and methanol excreted in the urine. Eight subjects with the highest levels of Ph in the urine had decreased erythrocyte and T-helper lymphocyte numbers, and increased numbers of eosinophils and monocytes. The results obtained prove that the functions of both the immune and hematopoietic systems could be affected by chronic exposure to these toxic substances.
Granulocyte factor (GF) is a substance secreted selectively from the specific granules of granulocytes in the first minutes of adherence or phagocytosis. GF possesses many immunoregulatory functions. We applied flow cytometric analysis to evaluate the target cells responsible for GF action. Resting lymphocytes did not display binding sites for GF, but 93 +/- 4.6% of the neutrophils isolated from peripheral blood bound GF (mean fluorescence = 122 +/- 11). GF was bound by 26 +/- 7.6% of the lymphocytes from nonstimulated and 42.6 +/- 12% of the lymphocytes from PHA-stimulated cultures, and the mean fluorescence intensity was 14.5 +/- 1 and 54 +/- 10.6, respectively. PHA-stimulated CD8+ cells presented higher expression of binding sites for GF than CD4+ cells. Binding sites for GF were found on 66 +/- 5.1% of activated cells expressing the receptor molecule to IL-2 (CD25) and 50.3 +/- 7.4% of cultured lymphocytes expressing the early activation marker CD69. These values were significantly higher in comparison to the percentage of CD25- and CD69- cells that bound FITC-labeled GF (10.3 +/- 3.3% and 11.3 +/- 3.5%, respectively). The binding was specific, and preincubation of the cells with GF almost completely abolished FITC-labeled GF binding. It has also been shown that GF binds to lymphocytes via molecules other than CD16. High-performance liquid chromatography (HPLC) with fractionated GF showed three separate fractions and two of them had GF-like activity, as demonstrated in the mixed lymphocyte reaction (MLR).
In allergy the immune response is significantly modified by inflammatory processes. Polymorphonuclear leukocytes (PMNLs) are involved in inflammatory processes. Activated PMNLs release many substances, including granulocyte factor (GF), which exerts immunomodulating effects. The present study was performed to determine the effects of allergens and/or GF on the expression of lymphocyte differentiation antigens in short-term cultures and to evaluate the production of migration inhibitory factor (MIF) under the influence of these substances. The studies were carried out on peripheral blood mononuclear cells isolated from patients with type I hypersensitivity, before and after the grass pollen season, and from healthy subjects. GF and allergens were found to increase the CD8 cell number, particularly in 7-day cultures and in patients before exposure to allergens, which correlated with MIF release in these patients under the influence of these factors. The results suggest that the PMNLs may participate in allergic inflammatory reactions.