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Biomedical subjects

S Sipka

Publications and source records attributed to S Sipka.

At least 19 recordsLinked to original sources
PubMed1992

Histamine potentiates human platelet aggregation induced by platelet-activating factor.

Using human platelet-rich plasma (PRP) we found that histamine concentration-dependently potentiated platelet aggregation induced by platelet-activating factor (PAF). When added separately, neither histamine nor chloropyramine, a competitive antagonist of H1 receptors, influenced platelet aggregation, however BN 52021, a specific PAF receptor antagonist, concentration-dependently inhibited the response. Chloropyramine reduced the potentiating effect of histamine on PAF-induced platelet aggregation, and when it was coadministered with BN 52021, inducing 63% inhibition of PAF-induced aggregation, the histamine-potentiated PAF response was completely abolished. This observation draws attention to the importance of cooperation between histamine and PAF in mediation of platelet aggregation in human PRP, and points to the powerful antiaggregatory effect of BN 52021 combined with an antagonist of H1 receptors.

Diterpenes↗
PubMed1991

Effects of suramin on phagocytes in vitro.

In the therapeutically important range (100-200 micrograms/ml), suramin was found to increase the phagocytic activity of human monocytes (measured by the uptake of Saccharomyces cerevisiae and sensitized sheep red blood cells) in vitro. Suramin itself was a chemotactic signal for monocytes and increased the chemiluminescence of neutrophil granulocytes. Suramin seems to act via the ATP-binding P2 receptors of human phagocytes.

Adenosine Triphosphate↗
PubMed1991

Decrease in the carbamylcholine-induced chemotaxis of monocytes in myasthenia gravis.

The carbamylcholine-induced chemotaxis of monocytes was decreased in patients with myasthenia gravis, whereas no change was found in the C5a-induced locomotion of these cells compared with that of the normal controls. The decrease in the chemotaxis induced by carbamylcholine correlated with the severity of clinical symptoms. The beneficial effect of thymectomy was also reflected in the improvement of chemotaxis. The method is simple, not expensive and could be used in the diagnosis of myasthenia gravis.

Carbachol↗
PubMed1991

Phagocytosis of autologous platelets by human neutrophil granulocytes.

The phenomenon that the autologous human platelets can be phagocytosed in vitro by neutrophils and monocytes of healthy human donors (being free of antiplatelet autoantibodies) was demonstrated earlier. In this study we have confirmed electron microscopically the phenomenon of phagocytosis. Besides, using flow cytometric analysis, we have shown that a possible way for the bridge-formation between the washed platelets and neutrophils can be the linkage via IgG + C3b complexes bound to the Fc receptors of platelets. This mechanism supposedly may play a role also in the clearance of platelets by peripheral phagocytes in vivo.

Blood Platelets↗
PubMed1991

Autoantibody against liver cell membrane and killer cell activity in chronic liver diseases.

The aim of our present study was to examine the ADCC reaction against liver cell in various chronic liver diseases on the basis of indirect evidence. Forty-nine liver patients and one hundred and twenty-three healthy controls were examined. Anti-LSP autoantibody was determined on rat liver membrane by using the indirect immunofluorescent method. On the other hand, Killer-cell activity against human erythrocyte target cells was established in the lymphocytes of peripheral blood. Anti-LSP autoantibodies were demonstrated in seven patients and were associated with the high Killer-cell activity in six cases. Specific ADCC reaction to liver cell membrane can be assumed if anti-LSP autoantibody presence is topped with increased Killer-cell activity.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1991

Measurement of complement components and alpha 1-antitrypsin during plasma exchange.

Therapeutical plasma exchange can be carried out by using blood cell separators based upon centrifugation or in equipments with membranes. We investigated whether activation of the complement system took place in polyvinylchloride tubes used in the blood cell separator. We also examined the changes in the classical and alternative complement pathways by an analysis of functional haemolytic titers, as well as the levels of C4, C3D, C4, albumin and alpha 1-antitrypsin. No measurable activation of the complement system was found. The decreased levels of the C3, C3d, C4, albumin and alpha 1-antitrypsin in the sera after PE could be a consequence of the haemodilution.

Blood Group Incompatibility↗
PubMed1991

Leukocytosis induced by plasma exchange.

A significant increase was found in the number of white blood cells, including neutrophils, in the peripheral blood of patients during plasma exchange. However, the spontaneous chemiluminescence of peripheral white blood cells (basically characterized the activated state of neutrophils) was not elevated. This finding suggests a relative deficiency in the metabolism of neutrophils during plasma exchange. This idea is supported by the observation that the levels of malonyldialdehyde in plasmas, after plasma exchange, do not increase, indicating that the activation dependent lipid peroxidation in neutrophils did not take place.

Humans↗
PubMed1989

Simultaneous presence of platelet activating factor, leukotriene B4, prostaglandin F1 alpha and F2 alpha in the supernatant of human neutrophils treated with phospholipase A2 of human monocytes.

The simultaneous presence of platelet-activating factor, leukotriene B4, prostaglandin F1 alpha and F2 alpha are detectable in the supernatant of human neutrophil granulocytes treated with phospholipase A2 of human monocytes. This enzyme is suspected to play an important role in the pathomechanism of inflammation.

Dinoprost↗
PubMed1989

[Whole blood, chemiluminescence in patients with periapical granuloma].

Spontaneous and mannozyme-induced whole blood chemiluminescence was studied in 14 patients with chronic periapical granuloma. Investigations were performed before surgery and 7 days as well as 3 months after apicectomy. Spontaneous chemiluminescence was significantly higher in patients versus normal controls. The elevated spontaneous chemiluminescence decreased significantly after surgery. Results indicate that, in these patients, granulocytes are in a metabolically and functionally activated state in vivo.

Adult↗
PubMed1988

The antigen/receptor specificity of antigranulocyte antibodies in patients with SLE.

The antigen/receptor specificity of antigranulocyte antibodies (AGAs) detected in the sera of patients with systemic lupus erythematosus (SLE) was investigated by inhibitory immunofluorescence test and Western immunoblotting technique. The interactions of AGAs with antigens of intact normal granulocytes were determined by inhibiting the binding of different myeloid monoclonal antibodies (mAbs). Seven of the studied 12 sera revealed binding to CD15 (X hapten) and/or to CD16 (FcR1o). The specificity investigation of AGAs was completed with Western immunoblotting technique. The binding of AGAs to bands with Mr of about 50-60 kDa and at 30 kDa on unstimulated granulocyte plasma membrane preparation could be demonstrated from 4 out of 6 AGA positive SLE sera. The cause of the disappearance of bands on the phorbol-myristate-acetate (PMA) activated membrane except those of the 50-60 kDa bands is still to be discovered.

Adult↗
PubMed1988

Neutral-red uptake and expression of monocytic antigens in amniotic-fluid mononuclear phagocytes: evaluation of a novel approach for prenatal diagnosis of neural-tube defects.

In cases of fetal neural-tube defects macrophages are present in the amniotic fluid. We found that these viable phagocytic cells take up neutral-red and are easily identified as "red cells" by microscopic examination. This method is suitable for the rapid identification and counting of amniotic-fluid macrophages in suspension. We have studied 298 amniotic fluid samples. In the 226 normal cases studied, 0 to 1,200 macrophages per milliliter amniotic fluid have been found. In contrast, we found 1,250 to 99,000 macrophages per milliliter amniotic fluid in our 70 open neural tube defect (ONTD) cases. Statistical evaluation was performed to estimate the normal and pathologic ranges. Specificity and sensitivity of the neutral-red test and predictive value of positive and negative results have been calculated and presented in comparison with alpha-fetoprotein (AFP) determinations and ultrasonic methods. In 5 cases of anencephaly and 7 normal cases amniotic fluid cells were studied by immunocytochemistry: mononuclear cells present in the abnormal cases showed intense immunoreactivity for the Mo1 and Mo2 surface antigens of the phagocytic cell lineage.

Amniotic Fluid↗
PubMed1988

Adenosine induced delay of expression of AIDS virus, HIV, in H9T cells.

Adenosine reduced the expression of CD4 antigen both in HIV infected and uninfected H9 T cells. The continuous presence of adenosine (1 mumol/ml) resulted in a remarkable delay of HIV expression in the infected cells. A relationship is suggested in the effects of HIV and adenosine on the human T cells.

Adenosine↗
PubMed1988

Immunobiological methods in the prenatal diagnosis and evaluation of foetal neural tube defects.

In cases of foetal neural tube defects (NTDs) macrophages are present in the amniotic fluid. These mononuclear cells were analysed with immunobiological methods: functional markers as Fc and C3b receptor-mediated phagocytosis and chemoluminescence have been studied. It was found that most of these pathognomic cells ingest haemolysin sensitized sheep red blood cells (sSRBCs) and zymosan (Mannozym) particles opsonized with fresh human serum. Amniotic fluid cell suspensions from pregnancies with and without foetal NTDs were stimulated by opsonized Mannozym; consistently higher chemoluminescence activities were found when open lesion was present. The evaluation of multiple functional markers is likely to provide a better basis for understanding the characteristics of amniotic fluid macrophages and may contribute to the prenatal diagnosis of NTDs.

Amniocentesis↗
PubMed1987

Immunocytochemical characterization of amniotic fluid macrophages in cases of fetal neural tube defects.

Amniotic fluid cells from 31 pregnancies with fetuses having open neural tube defects (NTDs) and from 43 pregnancies with fetuses free of NTDs were studied with the use of the immunoperoxidase method for alpha-fetoprotein (AFP) and glial fibrillary acidic protein (GFAP). The authors also used cytochemical stains for endogenous peroxidase and nonspecific esterase activity. In cases of NTDs, macrophages were present in the amniotic fluid, and in the authors' system they showed intense immunoreactivity for both AFP and GFAP and showed very strong activity for peroxidase and nonspecific esterase, whereas the epithelial cells and red blood cells showed no activity. In six cases of anencephaly, sections from the margin of the cranial end of defective spinal cords at the aperture of the open lesion were also studied for AFP and GFAP. In these cases, AFP- and GFAP-positive cells were found, indicating the possible neural (glial) origin of a part of amniotic fluid macrophages. Although the determination of AFP levels in maternal blood and amniotic fluid is widely used in the prenatal diagnosis of NTDs, demonstration of AFP in amniotic fluid cells by means of immunocytochemistry has not been described.

Amniotic Fluid↗
PubMed1987

Polymorphonuclear neutrophil function in systemic sclerosis.

In vitro functions of polymorphonuclear (PMN) neutrophils were studied in 20 patients with progressive systemic sclerosis (PSS). An increase in the basal chemiluminescence (CL) activity of peripheral blood PMNs was found, suggesting that these cells had been preactivated in vivo. Patients with more extensive skin disease or signs of disease progression tended to have higher basal CL values. Active oxygen products during the respiratory burst may increase the extent of inflammatory and fibrotic processes and could be involved in the endothelial injury in PSS. The stimulatory capacity of CL response was normal in our study. No alterations were found in the opsonised yeast phagocytic activity of granulocytes when compared with control values. The binding of erythrocyte-antibody particles was found also to be normal. A depressed chemotactic activity of PMN cells against zymosan activated serum was also shown. The cause of the decreased chemotaxis of PMNs remains to be elucidated.

Adult↗
PubMed1987

The effect of thymopoietin 32-34 (TP3) on suramin-induced inhibition on delayed type hypersensitivity in guinea pigs.

Suramin administration inhibits virus replication and produces impaired immunoregulation. Delayed type hypersensitivity (DTH)-reaction was inhibited by Suramin (200 mg/kg, i.p.) injection in guinea-pigs immunized with BCG vaccine. Suramin-inhibited DTH-reaction was restored to normal level after 4 days of treatment with thymopoietin 32-34 (TP 3) and TP5 (1 mg/kg, i.p.), TP3 greater than TP5. TP3 produced the strongest restoration when applied together with Suramin, but a single treatment with TP3 or TP5 oligopeptide inhibited the development of DTH-reaction. TP3 with Suramin treatment might be advantageous to eliminate defective side effects of Suramin on immune system and TP3 with indirect inducing action on IL-2, IFN-gamma production may be useful in therapy of AIDS patients.

Animals↗
PubMed1987

Effects of herpesvirus infections on the chemiluminescence induced by zymosan phagocytosis in mouse peritoneal macrophages.

The chemiluminescence (CL) induced by zymosan phagocytosis was tested in mouse peritoneal macrophages infected with three different types of herpes viruses: herpes simplex type-1 (HSV-1), human cytomegalovirus (HCMV) and murine cytomegalovirus (MCMV). The intensity of CL was tested in various intervals of virus infections. In the first eight hours zymosan induced chemiluminescence decreased in all the three systems. By the 24th hour, the macrophages infected with HCMV had almost completely recovered from the early defect, while in the macrophages infected with both HSV-1 and MCMV, the chemiluminescence induced by zymosan remained impaired.

Animals↗