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Biomedical subjects

M Zembala

Publications and source records attributed to M Zembala.

At least 91 records · Page 5Linked to original sources
PubMed1994

The MHC class-II and CD44 molecules are involved in the induction of tumour necrosis factor (TNF) gene expression by human monocytes stimulated with tumour cells.

Tumour necrosis factor alpha (TNF) mRNA is detected in the macrophage infiltrate surrounding the tumour, but the cellular/molecular interactions leading to TNF gene expression in macrophages are unknown. The in vitro system in which human blood monocytes are stimulated with human cancer cells for TNF release was used to study such interactions. Monoclonal antibodies (MAbs) against various adhesion molecules (LFA-1, LFA-3, ICAM-1, VNR, VLA beta I chain) were unable to block TNF production in co-culture of monocytes with a human pancreatic carcinoma (HPC) cell line. However, anti-CD44 and anti-HLA-DR MAbs effectively blocked TNF release and TNF-mRNA induction in monocytes. Pre-incubation of monocytes with anti-HLA-DR and tumour cells with anti-CD44 MAbs had a similar effect. It was concluded that CD44 molecules are involved in tumour-monocyte interactions and that HLA-DR determinants of monocytes are engaged in signal transduction for TNF gene activation. These findings may suggest that certain surface determinants of tumour cells act as ligands for MHC class-II molecules and induce TNF production in monocytes.

Antibodies, Monoclonal↗
PubMed1994

Human monocytes are stimulated for nitric oxide release in vitro by some tumor cells but not by cytokines and lipopolysaccharide.

Nitric oxide (NO) has been recently identified as a potent mediator of tumoricidal activity of activated macrophages. Macrophages can be activated for tumor cell killing by microbial products, including lipopolysaccharide (LPS) and various cytokines. Here we report that in contrast to mouse macrophages, human peripheral blood monocytes stimulated with cytokines or LPS failed to release NO. Also priming of monocytes with interferon-gamma followed by activation with cytokines or LPS did not cause NO secretion. However, monocytes responded with NO production to stimulation with some human cancer cells but not with untransformed cells. NO production by monocytes was inhibited by NG-monomethyl-L-arginine, specific inhibitor of NO synthase and emetine, an irreversible blocker of protein synthesis. This may imply that human monocytes are unique in their restricted capacity to produce NO following interaction with some tumor cells, but not with other stimulators, and in this respect they may be able to distinguish between malignant and normal cells.

Animals↗
PubMed1994

Modulation of antigen-presenting capacity of human monocytes by HIV-1 GP120 molecule fragments.

The two fragments of HIV-1 gp120 molecule were synthesized to study their interaction with human monocytes. Previous observations indicated that recombinant gp120 fragment (aa residues 410-511) encompassing CD4 binding region (rp120cd) induced tumour necrosis factor alpha (TNF) production in monocytes, while a similar fragment (rp120) not containing the CD4 binding sequence (aa 446-511) was inactive. This paper shows that rp120cd depressed monocyte ability to present antigen (PPD) to autologous T lymphocytes while rp120 was noninhibitory. The rp120cd interacted with monocytes but not T lymphocytes. Anti-TNF receptor type A antibody (utr-1) prevented the depression of antigen presentation caused by rp120cd, which suggested a role for TNF and its receptor. The depression of antigen presentation was seen only when monocytes were treated with rp120cd before, but not after, pulse with antigen. Parallel changes were observed in PPD-induced IL-6 production. Thus, induction of TNF by gp120 may be associated with impairment of antigen-presenting capacity of monocytes seen in AIDS patients.

Antigen Presentation↗
PubMed1994

[Concentration of myoglobin in serum in patients with heart transplantation].

The studies were carried out, the aim of which was the answer to question what are the changes of myoglobin concentration in patients after heart transplantation. For this purpose, 31 healthy persons being the control group (C) and 15 patients after heart transplantation (HTP) were studied. In both groups myoglobin concentration was determined by the RIA method, finding no statistically significant differences in changes of this parameter between the two studied groups. However, the nephrotoxic effect was confirmed of cyclosporin A which was continuously taken by the patients after heart transplantation, expressed as the decrease of creatinine clearance.

Adult↗
PubMed1993

Tumour-cell-induced production of tumour necrosis factor by monocytes of gastric cancer patients receiving BCG immunotherapy.

Human peripheral blood monocytes cocultured with tumour cells were used as an in vitro model of in situ interactions between tumour-infiltrating macrophages and the tumour. Tumour cells stimulated de novo expression of the human tumour necrosis factor alpha (TNF) gene in monocytes and caused the release of TNF into the culture supernatant. A group of 14 patients with stage IVA gastric cancer receiving adjuvant chemotherapy (5-FU, Adriamycin, mitomycin C: FAM) or immunochemotherapy (BCG+FAM) was investigated for the ability of monocytes to produce TNF in vitro upon stimulation with tumour cells or purified protein derivative of tuberculin (PPD). Patients were followed at biweekly intervals, i.e. before each instillation of BCG epicutaneously over a period of 10 weeks. It was found that monocytes of some patients receiving BCG at the end of the observation period had an enhanced ability to produce TNF following stimulation with tumour cells. In contrast, such production was not substantially altered during the study period in patients on chemotherapy. PPD-induced TNF production was much weaker and was not significantly changed during this observation time. We infer that BCG immunotherapy may induce the subtle changes in some cancer patients that lead to an increased interaction between monocytes and tumour cells and result in enhanced production of cytokine(s) with antitumour properties.

BCG Vaccine↗
PubMed1993

Types of interventricular septal branches of the anterior interventricular branch of the left coronary artery in human hearts.

The study aimed at determining types of interventricular septal branches stemming from the anterior interventricular branch of the left coronary artery. The studies were performed on 28 preparations of human heart aging 29 to 88 years. The technique of direct preparation was applied using a dissecting microscope. The conducted observations indicate that septal vessels of the anterior interventricular branch follow one of the three main patterns. Type I involves a dominant septal trunk, exhibiting its own branching and few fine septal branches, type II exhibits a single dominant unbranched ramus and multiple fine branches, while type III includes two dominant, unbranched septal rami of the septum and small number of fine septal branches. In the cases examined by us type III pattern was most frequent. No relationship was detected between the type of coronary vessels of the heart and the type of septal vessels of the anterior interventricular branch.

Adult↗
PubMed1993

[Constrictive pericarditis in a patient following prosthetic aortic valve replacement caused by postpericardiotomy syndrome].

A case of a 53-year old man is presented who developed postpericardiotomy syndrome and subsequently constrictive pericarditis following prosthetic aortic valve replacement due to severe aortic stenosis. The diagnosis was based on clinical picture and confirmed invasively. Nearly total excision of thickened fibrous pericardium resulted in a slow but full disappearance of constriction signs.

Aortic Valve↗
PubMed1992

Augmentation of monocyte-mediated cytocidal activity by a low dose tumour necrosis factor measured by the kinetic colorimetric microplate assay.

This paper describes a simple kinetic colorimetric assay for the quantitation of human peripheral blood monocyte-mediated cytotoxic activity against tumour cells. Isolated effector monocytes were cultured overnight with an increasing number of target cells in 96-well microplates. Cytotoxic activity of monocytes was determined by modified nitroblue tetrazolium (MTT) dye assay using standard ELISA reader offering possible automation. The test was performed with three different effector/target cell ratios using a fixed number of monocytes. This allowed the expression of cytotoxic activity of monocytes in cytotoxic activity units. The assay was found to be a simple method to demonstrate that low doses of TNF (1 U/ml) enhanced monocyte-mediated cytotoxicity.

Colorimetry↗
PubMed1992

[A case of direct right pulmonary artery-left atrium fistula].

An unusual case of cyanotic heart disease in a 20-year-old male has been presented. Cyanosis was due to right to left shunt through direct right pulmonary artery--left atrium fistula. After successful operative ligation of the fistula, the patient got rid of cyanosis and is doing well.

Abnormalities, Multiple↗
PubMed1992

Membrane-bound tumour necrosis factor alpha: immunocytochemical and ultrastructural studies of human monocytes and monocytic cell line and its induction by tumour cells in vitro.

Monoclonal antibody against recombinant human tumour necrosis factor alpha (rTNF) was used for the immunochemical detection of TNF in human blood monocytes and monocytic cell line U 937. Cells stimulated with phorbol myristate acetate (PMA) showed strong surface but not cytoplasmic staining. Unstimulated cells demonstrated weak or no staining. At early time after stimulation (1-2h) a spot reaction was seen in the Golgi area of the cytoplasm of stimulated cells. Coculture of tumour cells with monocytes also resulted in the induction of membrane TNF. Ultrastructural studies confirmed TNF localization within the cell membrane. These results indicate that TNF can be detected within the cells by immunocytochemistry which may make feasible studies on TNF appearance in cellular infiltrates in the tissues.

Antibodies, Monoclonal↗
PubMed1992

Immunolocalization of epidermal growth factor (EGF) in human salivary glands detected with the new monoclonal antibody.

Epidermal growth factor (EGF) is biologically active peptide commonly seen in many human tissues and organs. Its high concentration has been found in the salivary glands. The purpose of the present study was to determine EGF immunolocalization in normal human major salivary glands using a new monoclonal antibody anti-EGF. The results were compared with EGF location determined by using two human antibodies (Oncogene, USA and ICI from dr Gregory, UK). Immunohistochemical studies were performed by the PAP method. All antibodies demonstrated EGF expression in the efferent pathways of the salivary glands, especially in their proximal segments.

Antibodies, Monoclonal↗
PubMed1992

Immunoregulation of lymphoproliferation in vitro by monocytes and their subpopulations. II. Phenotypic changes of T cells in cultures activated with antigen and mitogen.

The aim of this study was to analyze phenotypes of T cells activated by mitogen (PWM) and antigen (PPD) in the presence of FcR+ or FcR- monocytes. It was found that CD4+ and CD8+ lymphocytes are preferentially activated in the presence of different monocyte subpopulations. Expression of HLA-DR and CD25 on CD4+ lymphocytes was greater in cultures activated in the presence of FcR-. CD8+ lymphocytes were more efficiently activated (expression of HLA-DR) when FcR+ monocytes were added to culture. In the presence of FcR+ monocytes an increased expression of CD45RA antigen on CD4+ cells was also observed. These data support our previous functional studies which showed that "suppressor" T cells of CD8+ phenotype are activated in the presence of FcR+ monocytes.

CD4 Antigens↗
PubMed1992

[Anatomical correction of transposition of the great arteries in 7 newborn infants].

In the presented article, the course and results of anatomical correction of transposition of great arteries (TGA) in 7 neonates (2 females and 5 males) with mean body mass of 3250 g and 2 to 5 days old (mean 3 days) are reviewed. Surgery was performed in moderate hypothermia. St. Thomas cold cardioplegia was used. Mean aortic clamping time was 70 min (55-115), and the time of extracorporeal circulation was 165 min (117-210). Low cardiac output in all patients in the postoperative period required prolonged mechanical ventilation and positive inotropic drugs. Out of 7 patients operated, two died (29%). The cause of death in both cases was myocardial ischemia of right ventricle. The other 5 patients were discharged after healing of operational wound. In the control echocardiographic examination performed 3 to 12 months postoperatively, apart from one case of moderate pulmonary artery stenosis, no other haemodynamically significant complications were noted.

Coronary Vessel Anomalies↗
PubMed1992

Epidermal growth factor (EGF) expression in human salivary glands. An immunohistochemical study.

Epidermal growth factor (EGF) is a biologically active peptide involved in differentiation, growth, regeneration and repair of human and animal tissues. Quantitative biochemical studies showed in man the highest concentration of EGF in the parotid gland. The aim of the present study was to define EGF immunolocalization in the individual segments of the human major salivary glands (salivon). The material consisted of sections obtained from the surgically removed salivary glands: parotid, submaxillary and sublingual. Immunohistochemical studies were performed by PAP method using monoclonal antibody against human epidermal growth factor. EGF expression was found almost exclusively in the efferent pathways of the salivary glands, mostly in the intercalated ducts and Pflüger salivary tubules. These segments of the salivon are most developed in the parotid gland in which the staining was stronger than in other salivary glands.

Epidermal Growth Factor↗
PubMed1992

FcR+ and FcR- monocytes differentially secrete monokines during pokeweed mitogen-induced T-cell-monocyte interactions.

Monocyte subpopulations which differ in the expression of Fc receptor for human IgG (FcRI) differentially regulate the T-cell-dependent, pokeweed mitogen (PWM)-induced, polyclonal B-cell response. We, thus, studied the cytokine production in human peripheral blood monocyte and T-lymphocyte cultures activated with this lectin. Monocytes or their FcR+ and FcR- subpopulations stimulated with PWM were cultured with or without T lymphocytes or their CD4+ and CD8+ subsets. Both monocyte subpopulations cultured alone produced similar amounts of tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), but FcR- monocytes showed significantly enhanced ability to secrete interleukin-1 (IL-1). T cells, especially CD4+, added to monocyte cultures enhanced IL-1 production. This enhancement was presumably due to interferon-gamma (IFN-gamma) release by T lymphocytes, since this lymphokine enhanced IL-1 secretion when added to PWM-stimulated cultures of monocytes. Addition of monocytes, in particular the FcR+ subpopulation, greatly enhanced production of IFN-gamma by T lymphocytes. Although both T-cell subsets produced IFN-gamma, the CD4+ cells were more efficient. These results indicate that in PWM-stimulated cultures subpopulations of monocytes differ in secretion of cytokines, which might explain their differential effect on T-cell-dependent immune responses in vitro.

Antigens, Differentiation↗
PubMed1992

Effect of peritoneal macrophages from intermittent peritoneal dialysis patients on lymphocytes in culture.

To investigate the biological activity of peritoneal macrophages, cells isolated from dialysate of 30 patients with end-stage kidney disease treated by intermittent peritoneal dialysis and from ascites of 6 patients with cardiac insufficiency (relative control group) were added to autologous, phytohemagglutinin (PHA)-stimulated lymphocyte cultures. Macrophages of dialyzed patients induced a dose-dependent increase in autologous lymphocyte proliferation, whereas macrophages obtained from control subjects exerted a suppressive effect on those cultures. The enhanced lymphocyte proliferation by macrophages from dialyzed patients was corroborated by the increased metabolic activity of macrophages as evaluated by the increased nitro blue tetrazolium (NBT) reduction test and increased functional expression of Fc receptors (FcR). The subpopulation of macrophages from patients with HLA-DR antigens as determined by HB55 monoclonal antibody, inhibited lymphoproliferation in vitro. We conclude that peritoneal macrophages from dialyzed patients represent a heterogenous population of cells with different phenotypic and functional characteristics.

Adult↗