Different inhibitory effects of kynurenic acid and a novel kynurenic acid analogue on tumour necrosis factor-α (TNF-α) production by mononuclear cells, HMGB1 production by monocytes and HNP1-3 secretion by neutrophils.

Kynurenic acid (KynA), a broad spectrum antagonist of excitatory amino acid receptors, may serve as a protective agent in neurological disorders. The potential anti-inflammatory effect of KynA in human leukocytes has not been characterized. The aim of this study was to compare the effects of KynA with those of a new analogue, 2-(2-N,N-dimethylaminoethylamine-1-carbonyl)-1H-quinolin-4-one hydrochloride on tumour necrosis factor-α (TNF-α) production and high mobility group box protein 1 (HMGB1) secretion.

Helicobacter pylori induces the release of alpha-defensin by human granulocytes.

Objectives: Little information is available on the potential role of alpha-defensins derived from neutrophils during H. pylori infection, or the effect of H. pylori on the alpha-defensin release.

Investigation of the prognostic value of TNF-alpha gene polymorphism among patients treated with infliximab, and the effects of infliximab therapy on TNF-alpha production and apoptosis.

Objectives: Infliximab, a chimeric anti-tumor necrosis factor (TNF) antibody, is highly effective for the treatment of Crohn's disease (CD) and rheumatoid arthritis (RA). Our experiments focused on RA and CD patients receiving infliximab. Since cytokine production is largely determined by genetic factors, the promoter polymorphisms of TNF-alpha were examined among these patients.

The effects of medium-strength electric impulses on human blood.

Leukocyte subsets, total leukocyte isolates or full blood samples were subjected to medium-strength square-wave electric impulses (100 V/cm field force, 5 ms duration). On the surface of the leukocytes, the expressions of several markers (CD3, CD4, CD8, CD11a, CD11b and ICAM-1) were determined in order to study the influence of pulsed ionic currents on different aspects of the cellular immune response. Large individual differences were observed among randomly chosen healthy donors, both in the initial expression rate and in the response patterns of different antigens.

Relevance of ICAM-1 to alcoholic liver cirrhosis.

An elevated serum concentration of soluble intercellular adhesion molecule-1 (sICAM-1) was observed in patients with alcoholic liver cirrhosis in strong correlation with the current activity of the liver disease and the history of alcohol consumption. Circulating ICAM-1 levels were significantly elevated in the sera of all of 25 patients (1,400 +/- 850 ng/ml) compared with normal healthy subjects. The highest levels of sICAM-1 (2,650 +/- 560 ng/ml) were measured in those patients who suffered from superimposed acute alcoholic hepatitis (SAH).

Reversal of multidrug resistance by amitriptyline in vitro.

Amitriptyline, a tricyclic antidepressant, was able to reverse the multidrug resistance efflux pump of human colon cancer subline SW 620 and multidrug resistant (mdr) mouse lymphoma cells by decreasing rhodamine 123 efflux. The inhibitory effect of amitriptyline on the efflux pump was dose dependent. An investigation was made of the effects of mouse tumour necrosis factor (TNF) alpha and interferon (IFN) gamma on the efflux pump activity of mdr cells together with amitriptyline compared to the par cells (mdr-).

Interleukin-8 induces HLA-DR expression on cultured human keratinocytes via specific receptors.

Recent studies suggest that interleukin (IL)-8 exerts a direct influence on several functions such as the chemotaxis or proliferation of human keratinocytes (HK). Since the effects of IL-8 in skin are mediated through specific receptors, we have studied the characteristics of the keratinocyte IL-8 receptor. We could identify specific binding sites for IL-8 in cultured HKs by flow cytometry.

Inhibition of tumor necrosis factor production and ICAM-1 expression by pentoxifylline: beneficial effects in sepsis syndrome.

Tumor necrosis factor (TNF) has a pivotal role in the pathogenesis of sepsis and septic shock. Suppression of its biosynthesis might therefore be one of the strategies in the treatment of sepsis. When peripheral white blood cells were stimulated with either E.

Effects of pentoxifyllin and PentaglobinO on TNF and IL-6 production in septic patients.

Pentoxifylline inhibited the TNF production of purified human white blood cells and whole blood cultures stimulated either by LPS or by Staphylococcus aureus. PTX did not influence the CD14 expression. The in vitro TNF and IL-6-producing capacities of septic patients were higher than in the control group.

Effects of amino and imino acridines on tumor necrosis factor production by human leukocytes.

Tumor necrosis factor (TNF) is a multifunctional cytokine with diverse effects on different cells and tissues. The biological activity of TNF is described on the basis of its cytotoxic action in vivo and in vitro. Different acridines were systematically synthesized and their effects were tested on endotoxin and Staphylococcus aureus-induced TNF production by human leukocytes.

Effect of phytohaemagglutinin on CD45 in T cells.

In this study the effect of PHA activation on the phosphatase activity of CD45 has been investigated in human leukemic T-cell lines. It has been found that in vivo activation of the cells with PHA resulted in 2-4-fold increase in enzyme activity. Addition of PHA to the postnuclear supernatant of cell lysates also resulted in elevation of phosphatase activity.

Multiple effects of promethazine in Staphylococcus aureus.

The antibiotic resistance of 6 Staphylococcus aureus strains was eliminated with a frequency from 1.2 to 10% in the presence of subinhibitory concentrations of promethazine. The pigment production of the cells was also eliminated by the promethazine to an extent of 0 to 5%.

Expression of human sialophorin (CD43) in a human x mouse somatic cell hybrid.

We have studied the expression of the human sialophorin (CD43) molecule in a human x mouse somatic cell hybrid (H-8). The CD43 molecule was detected on the cell surface by immunofluorescence analysis and the hybrid cell possessed human chromosome 16 which carries the gene for CD43. Biochemical analysis showed that the cell line expressed a low molecular form of CD43, which was due to altered glycosylation.