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Biomedical subjects

J Wybran

Publications and source records attributed to J Wybran.

At least 19 recordsLinked to original sources
PubMed1990

Excessive in vitro bacterial lipopolysaccharide-induced production of monokines in cirrhosis.

The objective of this study was to analyze monokine production by peripheral blood mononuclear cells from patients with alcoholic cirrhosis. The capacity of peripheral blood mononuclear cells and purified monocytes from these patients to produce tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 was investigated. Spontaneous production of tumor necrosis factor alpha, interleukin 6 and interleukin 1 beta was similar in cirrhotic and healthy subjects, but serum levels of interleukin 6 (less than 2 U/ml vs. 9.5 +/- 3 U/ml) and tumor necrosis factor alpha (3.1 +/- 1.2 pg/ml vs. 12.0 +/- 1.2 pg/ml) were significantly higher in cirrhotic patients. However, peripheral blood mononuclear cells or purified monocytes from patients with alcoholic liver cirrhosis, stimulated in vitro with Escherichia coli lipopolysaccharide, displayed a marked increase of tumor necrosis factor alpha, interleukin 1 beta and interleukin 6 secretions compared with healthy controls. A striking feature of this overproduction was its reversibility as assessed by allowing cells to rest in vitro without lipopolysaccharide for 1 to 7 days before stimulation. In such conditions, tumor necrosis factor alpha and interleukin 6 secretions declined to levels present in healthy subjects in whom production remained stable, whereas interleukin 1 beta secretion markedly decreased in both groups to the point where no difference could be seen. This reversible oversecretion of cytokines after lipopolysaccharide stimulation, along with the lack of abnormality of spontaneous cytokine secretion, suggests that monocytes in these patients may have undergone an in vivo activation process analogous to a priming phenomenon. The in vitro activation with lipopolysaccharide may represent the correlate of in vivo endotoxemia observed during acute events such as sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)

Cells, Cultured↗
PubMed1990

Activation of natural killer cells and cytokine production in humans by bacterial extracts (OM-85 BV).

The influence of Broncho-Vaxom (BV) on different immune parameters was investigated in vitro on human peripheral blood mononuclear cells (PBMC). It was found that BV enhances the natural killer (NK) activity of PBMC and increases their spontaneous and phytohemagglutin (PHA)-induced production of tumor-necrosis factor--alpha and interleukin-2 as well as the PHA-stimulated production of interferon-gamma. These immunostimulating actions of BV on NK activity and cytokine production can contribute to the understanding of the enhancement of the body's defense mechanisms against respiratory tract infections.

Humans↗
PubMed1989

Sulfadiazine revisited.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Release of tumor necrosis factor, interleukin-2, and gamma-interferon in serum after injection of OKT3 monoclonal antibody in kidney transplant recipients.

High levels of tumor necrosis factor-alpha, interleukin-2, and gamma-interferon appeared in the circulation of kidney transplant recipients after the first injection of the monoclonal antibody OKT3. This initial injection was systematically followed by fever. The three cytokines were released in all patients (n = 9), with peak serum levels of tumor necrosis factor occurring 1 hr after OKT3 injection and those of interleukin-2 and gamma-interferon after 2 hr. Cytokines were not released after the second and third OKT3 injections, when CD3+ cells had disappeared from blood. These findings suggest that circulating cytokines are released by T cells after activation by OKT3. These cytokines are probably involved in the systematic reactions observed after injection of OKT3.

Antibodies, Monoclonal↗
PubMed1989

Enhancement of cytokine production and natural killer activity by an Escherichia coli extract.

OM-89 is a bacterial extract of E. coli which is clinically used in the treatment of urinary tract infections. Since immunological mechanisms may play a role in its action, its immunological effects were evaluated in vitro on peripheral blood mononuclear cells. The results showed that OM-89 enhances natural killer activity, as well as the spontaneous production of alpha-TNF and IL2. In the presence of various mitogens, it enhanced the production of IL1, gamma-IF, alpha-TNF and IL2. These data indicate that OM-89 acts on cell-mediated mechanisms by a direct and/or an indirect effect on monocytes, T cells and natural killer cells. These data suggest that the clinical activity by OM-89 may be related to its immunological properties.

Adjuvants, Immunologic↗
PubMed1989

Activation of natural killer cells and cytokine production in man by bacterial extracts.

Broncho-Vaxon (OM-85 BV) is a bacterial extract of eight bacterias usually involved in the respiratory tract infections. Since Broncho-Vaxom is clinically active in decreasing the incidence of such infections, its immunological effect was investigated, in vitro, using peripheral blood mononuclear cells (PBMC). The experimental data indicate that Broncho-Vaxom can modulate various immune functions. It was shown, using a radioimmunoassay for these cytokines, that Broncho-Vaxom will spontaneously enhance TNF alpha and IL-2 production whereas it has no action on IF gamma production. However, when the PBMC are stimulated with PHA, an increased production for IF gamma, TNF alpha and IL-2 was observed suggesting that, under appropriate conditions, Broncho-Vaxom enhances the production of these cytokines. In other experiments, Broncho-Vaxom was shown to markedly increase the natural killer activity of PBMC. All these results demonstrate that Broncho-Vaxom is an immunomodulator affecting multiple immunological mechanisms including the activation of natural killer cells, of monocytes and of T cells through direct mechanisms or through the cytokine cascade.

Adjuvants, Immunologic↗
PubMed1989

High interleukin-6 serum levels and increased production by leucocytes in alcoholic liver cirrhosis. Correlation with IgA serum levels and lymphokines production.

Hypergammaglobulinaemia and enhanced serum IgA levels are common in alcoholic liver cirrhosis. Interleukin-6 (IL-6), which is identical to B cell differentiation factor BSF2 and is implicated in various autoimmune diseases, has been studied in patients with alcoholic liver cirrhosis. Increased serum levels and spontaneous or induced production of IL-6 by peripheral blood monoclonal cells have been found. IL-6 production correlates closely with IgA serum levels and negatively with impaired interleukin-2 and interferon gamma production. This abnormality could be related to overproduction of immunoglobulins and immune disturbances observed in this disease.

Female↗
PubMed1989

[Preoperative autotransfusion for elective surgery].

In order to eliminate the risk of transmission of infectious diseases and of alloimmunisation, a pre-deposited autologous blood program for elective surgery has been started at the Erasmus Hospital. In 8 months, 51 patients have given 111 units of packed red cells and 111 units of fresh plasma. Two vasovagal reactions were observed. Four patients were withdrawn from the program in view of a hematocrit decreasing below 34%. Out of these 51 patients, 27 (53%) were transfused with only autologous blood. The autologous blood not distributed to these patients was given to other patients (10% of packed red cells and 24% of plasma). This pre-deposited autologous program has allowed to operate more than 50% of patients, undergoing elective surgery, only with autologous blood and to save homologous blood. The pre-deposited blood appears to be an interesting tool in transfusion safety and in the reduction of blood demand.

Blood Preservation↗
PubMed1988

Immune status in healthy relatives of patients with familial Crohn's disease.

Immune-mediated mechanisms and genetic factors are believed to be involved in the pathogenesis of Crohn's disease. We studied T- and B-cell subpopulation proportions and various functional assays, including proliferative responses to PHA and Con A, Con A-induced suppressive activity, and natural killer cell assay toward the K562 cell line, in the peripheral blood of 22 patients with inactive familial Crohn's disease and their 35 healthy relatives including nine families. HLA-A, -B, and -DR antigens were determined in all the subjects. With the exception of minor abnormalities of suppressor cell activity present in some relatives of two families, neither significant impairments of immunological parameters in patients or their relatives nor concordant segregation of HLA haplotypes and disease were observed. These data indicate that peripheral immune abnormalities previously described in patients with Crohn's disease do not constitute primary factors involved in the disease itself and that familial incidence in Crohn's disease cannot be linked to immunological markers presently studied.

Adolescent↗
PubMed1988

Granulocyte elastase compared to C-reactive protein for early diagnosis of septicemia in critically ill patients.

Plasma levels of granulocyte elastase and C-reactive protein were measured 0, 12, 24 and 48 h after suspicion of septicemia in 64 critically ill patients. Initial elastase levels were higher in 16 bacteremic patients (mean 773 micrograms/l) than in 48 non-bacteremic patients (mean 341 micrograms/l, p less than 0.01), whereas C-reactive protein levels were similar in both groups. At a level of 100% sensitivity for the early detection of septicemia, increased elastase was less than 50% specific, indicating limited diagnostic usefulness in this setting.

C-Reactive Protein↗
PubMed1988

Decreased proliferative activity associated with activation markers in patients with alcoholic liver cirrhosis.

Peripheral blood mononuclear cells from 15 patients with alcoholic cirrhosis (AC) and 15 matched healthy controls were tested for their proliferative response to mitogens such as PHA and con A, tumour promoter PMA and OKT3 monoclonal antibody, for their capacity to produce IL-2 and to respond to recombinant IL-2 (rIL-2). The expression of IL-2 receptor (Tac) together with two other activation markers, the receptor for transferrin (T9) and Ia antigen have also been assessed. A profound decrease of proliferative response was observed after stimulation by lectins and PMA. IL-2 production was significantly decreased (0.39 +/- 0.07 versus 0.82 +/- 0.009 units; P less than 0.001) in alcoholic cirrhosis. Resting PBMC of these patients disclosed spontaneous responsiveness to rIL-2 without requiring prestimulation with PHA as observed in healthy subjects. This abnormal response was associated with significantly increased percentages of Tac (19.4 +/- 3.1 versus 5.1 +/- 1.1%; P less than 0.001), T9 (13.6 +/- 3.3 versus 6.6 +/- 1.1%; P = 0.04) and Ia positive cells (21.4 +/- 5.4 versus 11.5 +/- 1.4; P less than 0.05) in alcoholic cirrhosis. Defective proliferative activity and impaired IL-2 production, combined with an increase of lymphocytes bearing T cell activation markers and of rIL-2 responsiveness could represent in vitro correlates for mechanisms leading to immunoregulatory disturbances in cirrhotic patients.

Adult↗
PubMed1988

Cryptococcal anal ulceration in a patient with AIDS.

We report the case of an African patient with acquired immune deficiency syndrome (AIDS) who had a chronic cryptococcal rectal abscess with anal fistula and a disseminated neurologic and bony fungal disease, associated with pulmonary infiltration due to Pneumocystis carinii. The anal lesion was surgically excised because of failure of the medical treatment. Although clinical intestinal cryptococcal involvement is quite rare, the experience here recorded should draw physicians' attention to the possibility of an insidious disseminated disease in AIDS patients.

Abscess↗
PubMed1987

Internalization of human T lymphocyte receptors.

Monoclonal antibodies specific to human T lymphocyte receptors are currently being used to define the biochemical structure of these proteins as well as of functionally distinct cell subsets. Since one of the antibodies (OKT3) recognizing the T3 (CD3) receptor mimics vital physiological processes involved in the activation of the immune system and has been successfully used as a therapeutical agent, we investigated one of the mechanisms underlying this antibody-receptor interaction. Our results show that after binding of OKT3, the complex (OKT3-T3) disappears rapidly from the cell surface. Using electron microscopy, we found that this down-regulation is due to the internalization of the complex. Parallel experiments performed on the T11 (CD2) and T4 (CD4)/AIDS retrovirus receptor indicate that the same mechanism applies for the down-regulation of those molecules. These data suggest that the T3, T11 and T4 receptors have a behavior comparable to other well characterized, hormonal and viral receptors; they provide information on the metabolization pathway of surface receptors and on the possible intracellular penetration of ligands like the HTLV-III/LAV agent in human T lymphocytes.

Antibodies, Monoclonal↗