Helicobacter pylori neutrophil-activating protein stimulates tissue factor and plasminogen activator inhibitor-2 production by human blood mononuclear cells.

Helicobacter pylori neutrophil-activating protein (HP-NAP) is a virulence factor that activates phagocytic NADPH-oxidase. The effect of HP-NAP on the production of tissue factor (TF), plasminogen activator inhibitor-2 (PAI-2), and urokinase-type plasminogen activator (u-PA) by human blood mononuclear cells (MNC) was evaluated by using functional and immunological assays and mRNA analysis. HP-NAP induced time- and dose-dependent increases in TF and PAI-2, with a maximal effect at 300 nmol/L (>15-fold increase in antigens). No changes in u-PA were observed. When whole bacteria were used, an H. pylori mutant lacking HP-NAP was significantly less active than the wild-type strain. MNC from a patient with chronic granulomatous disease behaved as do normal cells, which indicates that HP-NAP effects can occur independently of NADPH-oxidase. HP-NAP, by inducing the coordinate expression of cell procoagulant and antifibrinolytic activities, might favor fibrin deposition and contribute to the inflammatory reaction of gastric mucosa elicited by H. pylori.

Sulfide enhancement of PMN apoptosis.

Hydrogen sulfide is a toxic metabolite released by several bacterial agents under anaerobic conditions. In the present paper, we investigated the effects of sulfide on polymorphonuclear cell (PMN) apoptosis, a mechanism suggested for limiting the toxic potential of neutrophils in inflammatory sites. We showed that 1 mM sulfide (concentration not conditioning PMN viability) is able to enhance the apoptotic fate of human granulocytes by increasing: i) the number of cells containing pyknotic nuclei, ii) the internucleosomal cleavage, and, iii) the intensity of tubulin immunofluorescence staining. The sulfide effect is partially prevented by ionomycin and this finding is consistent with the hypothesis of the inhibiting role played by high levels of cytosolic calcium in PMN apoptosis modulating.

Salivary up-regulation of human polymorphonuclear leucocyte chemotaxis and adhesion-molecule expression.

Chemotaxis and adhesion molecules were investigated in peripheral blood neutrophils incubated with saliva collected from healthy donors. A salivary concentration of 20% increased chemotactic responses and CD11a/CD18 and CD11b/CD18 expression, but had no effect on formyl-methionyl-leucyl-phenylalanine receptors.

Increased production of procoagulant activity (tissue factor) by human peripheral blood monocytes after Intralipid infusion.

Intralipid can produce functional and structural changes in the mononuclear phagocyte system. We have investigated the effect of Intralipid on the capacity of peripheral blood human monocytes to produce procoagulant activity when incubated in short term cultures. Twenty-three patients were studied before and after a single infusion of Intralipid 10%. Procoagulant activity was measured on isolated mononuclear cells after incubation (4 h at 37 degrees C) with and without endotoxin, using a one-stage clotting assay. Mononuclear cells obtained after Intralipid infusion produced significantly increased procoagulant activity as compared to their pre-infusion control samples (p < 0.005). Similar results were obtained when freshly collected whole blood was incubated with and without endotoxin (4 h at 37 degrees C) and procoagulant activity was measured on subsequently isolated mononuclear cells (p < 0.005). In all instances procoagulant activity was identified as tissue factor. Patients in the need of Intralipid are often at increased risk for thromboembolic complications and/or disseminated intravascular coagulation because of malignant disease, surgery or infection and there is evidence that the procoagulant activity of mononuclear phagocytes could play a major role in these processes. Our findings suggest that Intralipid might cause a further accentuation of the thrombotic tendency as a result of increased procoagulant activity.

[Biological effects of laser radiation and methylene blue on a strain of Salmonella typhimurium (TA 100) (II)]. / Effetti biologici della azione radiazione laser e bleu di metilene su un ceppo di Salmonella typhimurium (TA 100)--(NOTA II).

In this second note, the AA. have studied biological effect of laser radiation and methylene blue on Salmonella typhimurium TA 100 strain with greatest susceptibility for mutagenetic agents. Their results show a biological effect of laser radiation, of methylene blue like to those obtained for TA 1538 strain, nevertheless greatest susceptibility of TA 100 strain because carrier of plasmid.

[Biological effects of the combined action of laser radiation and methylene blue on a strain of Salmonella typhimurium (TA 1538) (I)]. / Effetti biologici della azione combinata radiazione laser e bleu di metilene su un ceppo di Salmonella typhimurium (TA 1538)--(NOTA I).

The AA. have studied biological effects of laser radiation and methylene blue (MB) on Salmonella typhimurium TA 1538 strain. Their results show low lethal effect of laser radiation directly proportional to administered dose. This effect is more evident in the only MB treatment. Lethal effect persisted, although non directly proportional with combined treatment laser and MB. Some treatments have not demonstrated mutagenetic effect. A new set of trials they are making on Salmonella typhimurium TA 100 strain with plasmid pK M 101 that give to strain greatest susceptibility for mutagenetic agents.

[Effects of cis-platin on the contractile system of polymorphonuclear leukocytes]. / Effetti del cis-platino sul sistema contrattile di leucociti polimorfonucleati.

The effects of cis-Platinum, a new antitumor drug, on guinea pig polymorphonuclear functions related to subplasmalemmal fibrillar structures, were investigated. The compound markedly decreased chemotaxis. Zymosan particles engulfment and degranulation. The depression of these leucocyte activities adds to the already known drug induced myelotoxicity .

Leukocyte inhibitory factor (LIF) production from lymphocytes stimulated by leucogenenol.

It has been demonstrated that human peripheral lymphocytes incubated in a tissue culture medium containing 0.04, 0.1, or 0.15 microgram/ml of leucogenenol form or release a factor that inhibits the migration of human peripheral PMN leukocyte. The factor is chromatographed of Sephadex G-100 and migrates on electrophoresis as an albumin, thus suggesting that it has the electric charge of an albumin. The factor is stable to neuraminidase and to heating at 56 degrees C for 30 min, but it is inactivated by heating at 80 degrees C for 60 min. Its physical and biological properties suggest that the factor is identical to the LIF reported by Rocklin.

[Activity inhibiting leukocyte migration in human sera of healthy subjects and of subjects with delayed hypersensitivity and findings of possible serum factors with antagonistic activity (author's transl)]. / Attivita'inibente la migrazione leucocitaria nel siero di donatori sani e di soggetti con ipersensibilita' ritardata e riscontro di possibili fattori sierici ad attivita' antagonista

The AA. have tested human sera from subjects with a clinical condition of delayed hypersensitivity (TBC and eczematous contact dermatitis) in order to detect factors affecting leukocyte migration in agarose plates. They found either inhibiting or stimulating factors of cellular migration. According to the most recent data about the same area they emphasyze a sort a regulatory mechanism of LIF or factors with activity LIF-like, due to antagonistic substances present in sera of their patients. Furthermore they suggest a list of factors able to inhibit or to enhance cellular migration.

Leukocyte inhibiting factor (LIF) production from human lymphocytes stimulated by bacterial lipopolysaccharides.

Leukocyte inhibiting factor (LIF) release from lymphocytes cultures stimulated by bacterial lipopolysaccharides (LPS) has been investigated. Human lymphocytes cultured in the presence of E, coli or S. enteritidis LPS were able to release in the supernatants a substance with the following properties: a) same elution pattern of Bovine Serum Albumin (MW 69000) when filtered on Sephadex G-100; b) it migrates on disc electrophoresis a an albumin; c) not dialyzable; d) not cytotoxic; e) inhibition of polymorphonuclear cells migration in agarose plates; f) heat stability at 56 degrees C for 30'. This substance could be likely identified as LIF.

Endotoxemia detected by Limulus assay in severe malnourished children. Plasma effects on leucocyte migration: preliminary investigations.

The Authors have examined 10 cases of severe malnourished children (7 cases of kwashiorkor, 2 cases of marasmus, 1 case of marasmic kwashiorkor). Experiments were carried in order to detect endotoxemia by means of Limulus test, bacteremia with blood cultures and possible effects of plasma on leucocyte migration by Leucocytes Migration Agarose Test (LMAT). The relationship between severe malnutrition, endotoxemia and leucocytes migration has been discussed.