[Effect of lipopolysaccharide and hypoxia on rat neutrophils in vitro].

The main aim of this study was to examine the role of lipopolysaccharide (LPS) and hypoxia on respiratory burst in rat neutrophils in vitro. Hypoxia (2% oxygen tension) inhibited respiratory burst of neutrophils in response to phorbol ester. Neutrophils treatment by LPS and hypoxia resulted in significant augmentation respiratory burst via NADPH oxidase activity in luminol chemiluminescence.

[The functional relevance of Arg16Gly and Gln27Glu-beta2-adrenoreceptor polymorphism in patients with asthma and allergic rhinitis].

The objective of the present study was to investigate the effect of beta2-adrenoreceptor polymorphisms Arg16Gly and Gln27Glu as well as their relationship to the pulmonary function parameters, and the clinical presentation in patients with asthma and allergic rhinitis. Investigated polymorphisms were in linkage disequilibrium, therefore their effects should be evaluated collectively. Although no significant association could be found with the presence of asthma or allergic rhinitis in studied population, polymorphisms of beta2-adrenoreceptor can influence pulmonary function in these patients.

Mechanisms of angiotensin-converting enzyme inhibitor induced thrombolysis in Wistar rats.

Our in vivo assay for thrombolysis consisted of recording the weight of platelet-rich thrombi adhering to a collagen strip that was superfused with arterial blood in extracorporal circulation of anaesthetised Wistar rats. Immediate thrombolysis occurred in response to intravenously administrated angiotensin-converting enzyme inhibitor (ACE-I) at non-hypotensive doses of 3-30 microg kg(-1) (captopril View Article and Find Full Text PDF

Acetate metabolism in brain mechanisms of adaptation to ethanol.

Background: The aim of this study was to estimate the role of acetate-induced metabolic changes in brain mechanisms of resistance to the narcotic effect of ethanol.

Material/methods: Wistar rats were treated daily with ethanol (3.5 g/kg i.

Interleukin 1beta induces functional prostaglandin E synthase in cultured human umbilical vein endothelial cells.

Prostaglandin endoperoxide H2 (PGH2) is generated from arachidonic acid by either constitutive (COX-1) or inducible (COX-2) cyclooxygenases. In arterial wall PGH2 is converted by PGI2 synthase (PGI-S) to prostacyclin (PGI2), and in platelets by thromboxane synthase (TX-S) to thromboxane (TXA2). Other prostanoids as PGD2, PGF2alpha, or PGE2 were believed to arise non-enzymatically from PGH2.

Bradykinin as a major endogenous regulator of endothelial function.

Healthy vascular endothelium is a powerful generator of nitric oxide (NO), prostacyclin (PGI2), prostaglandin E2 (PGE2), and plasminogen activator (t-PA). These endothelial products protect vascular wall against aggression from activated blood platelets and leukocytes. In particular they protect against thrombosis, promote thrombolysis, maintain tissue perfusion, and inhibit remodeling of vascular and cardiac walls.

Comparison of endothelial pleiotropic actions of angiotensin converting enzyme inhibitors and statins.

Two in vitro and one in vivo assay were performed to study the endothelial pleiotropic actions of "tissue type" angiotensin converting enzyme inhibitors (ACE-Is) such as perindopril and quinapril, their active forms, that is, quinaprilat and peridoprilat, or of statins belonging to natural (lovastatin), semisynthetic (simvastatin), and synthetic enantiomeric (atorvastatin, cerivastatin) classes. Cytoplasmic [Ca2+]i levels in cultured bovine aortic endothelial cells and endothelium-dependent nitric oxide-mediated coronary vasodilatation in the Langendorff preparation of guinea pig heart constituted our in vitro assays. The in vivo assay consisted of study of PGI2-mediated thrombolytic response in arterial blood of rats after intravenous administration of drugs.

Significance of endothelial prostacyclin and nitric oxide in peripheral and pulmonary circulation.

Background: Vasoprotective function of endothelial cells is associated, among others, with biosynthesis and release of nitric oxide (NO), prostacyclin (PGI2), prostaglandin E2 (PGE2), carbon monoxide (CO) and plasminogen activator (t-PA). These endothelial mediators calm down activated platelets and leukocytes, prevent the occurrence of parietal thrombotic events, promote thrombolysis, maintain tissue perfusion and protect vascular wall against acute damage and against chronic remodeling. Endothelial dysfunction in patients suffering from atherosclerosis or diabetes type 2 is associated not only with suppression in release of the above mediators but also with deleterious discharge of prostaglandin endoperoxides (PGH2, PGG2), superoxide anion (O2-, peroxynitrite (ONOO-), and plasminogen activator inhibitor (PAI-1).

The protective role of nitric oxide in the brain ischemia.

A role of nitric oxide in ischemia/reperfusion (I/R) injury of brain in normotensive (Sprague-Dowley rats, SD) and stroke-prone spontaneously hypertensive rats (SHR-SP) was studied. Cerebral ischemia was produced in rats by occlusion of the middle cerebral artery (MCA). NO and O2- releases in the brain in response to MCA occlusion followed by reperfusion were simultaneously monitored (2h) using electrochemical microsensors.

Thrombolysis by thienopyridines and their congeners.

We propose that anti-platelet thienopyridines, such as ticlopidine or clopidogrel, are thrombolytic owing to endothelial release of prostacyclin (PGI2) and tissue plasminogen activator (t-PA). In this study we used anaesthetised Wistar rats with extracorporal circulation in which arterial blood superfused thrombi which adhered to a strip of collagen. Weight of thrombi was continuously monitored.

Thienopyridines: effects on cultured endothelial cells.

In cultured endothelial cells harvested from human umbilical vein (HUVEC) or bovine aorta (BAEC) the 30 min incubation with calcium ionophore A 23187 (1 microM) or ticlopidine (100 microM) caused an increase in nitrite generation in HUVEC from basal 227 +/- 37 to 372 +/- 60 or to 325 +/- 33 pmoles per 10(6) cells, respectively, and in BAEC from basal 182 +/- 17 to 378 +/- 18 or to 423 +/- 66 pmoles per 106 cells (n = 6), respectively. Calcium ionophore A 23187 (1 microM) or ticlopidine (100 microM) next to 30 min incubation with BAEC increased release of 6-keto-PGF 1alpha from basal level of 9.4 +/- 1.

Effect of ticlopidine on streptokinase-induced thrombolysis in rats.

Using our original assay system we found that ticlopidine (TP, 30 mg/kg i.v.) had produced a prompt thrombolysis of preformed clots in extracorporeal circulation of anaesthetized rats.

Protective role of pulmonary nitric oxide in the acute phase of endotoxemia in rats.

We present for the first time direct continuous assay of NO concentration (porphyrinic sensor) in the lung parenchyma of Sprague-Dawley rats in vivo during endotoxemia. Intravenous infusion of lipopolysaccharide (LPS, 2 mg x kg(-1) x min(-1) for 10 minutes) stimulated an acute burst of NO from constitutive NO synthase (NOS) that peaked 10 to 15 minutes after the start of LPS infusion, mirroring a coincident peak drop in arterial pressure. NO concentration declined over the next hour to twice above pre-LPS infusion NO levels, where it remained until the rats died, 5 to 6 hours after LPS infusion.

Detection, by in situ hybridization using sulphonated cDNA probe, the specific mRNA for HLA-DR alpha induced in monocyte cell lines by recombinant interferon gamma.

We adopted the nonradioactive method used for blot hybridization for the detection of inducible mRNA for HLA-DR alpha by the in situ hybridization. Unstimulated and interferon gamma stimulated MonoMac6 and U937 human monocytic cell lines were used as target cells. Sulphonation of plasmid pBR322 with HLA-DR alpha cDNA insert (2 x 700 bp, in Pstl restriction site) was performed according to the manufacturer's procedure (SulfoProbe Kit, Sigma).

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.

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).

Functional characteristics of peritoneal macrophages of renal failure patients on peritoneal dialysis.

Functional activity of peritoneal macrophages of 50 patients with end-stage renal failure on intermittent peritoneal dialysis (IPD) and of 30 control subjects with normal renal function was determined. Phagocytosis of latex particles by macrophages of dialyzed patients was significantly lower as compared with the controls. Further depression of the phagocytic activity was observed during bacterial peritonitis.

The T cell receptor in the mouse.

In the eighties the genes of the T lymphocyte antigen receptor (TcR) have been cloned. The search for the elusive and controversial TcR is over. It is clear that genes for TcR are distinct from those of Ig genes although these genes belong to the immunoglobulin supergene family.

Juvenile rheumatoid arthritis. Monocyte dysfunction in selected patients.

The in vitro parameters of cell-mediated immunity were studied in 20 children with an established diagnosis of Juvenile rheumatoid arthritis (JRA) (age range 4-15 years) and 23 age- and sex-matched healthy children. (No attempt was made to correlate the observed changes with clinical course or treatment). We are not certain, at this time, of clinical relevancy or the generalizability of the findings.

Postoperative immunochemotherapy (BCG + 5-FU) in advanced gastric cancer.

Three hundred and twenty-two patients with locally advanced (stages III and IVA) and disseminated (stage IVB) gastric cancer were included in a randomized trial to assess the effect of immunochemotherapy (BCG and 5-fluorouracil,5-FU). The survival of patients receiving chemoimmunotherapy was compared to chemotherapy (5-FU) or no further treatment (control) groups. Patients with stage III underwent radical surgery (subtotal or total resection), stage IVA palliative resection, while explorative laparotomy or bypass was performed in stage IVB.

Immunoregulation of lymphoproliferation in vitro by monocytes and their subpopulations. I. The induction of suppressor T cells in long term cultures and the role of MHC class II determinants and preliminary characteristics.

Peripheral blood monocyte (MO) subpopulations isolated on a basis of functional expression or a lack of Fc receptor (FcR+ and FcR- MO) were used to study the regulation of the antigen (PPD)-driven lymphoproliferation. Long-term cultures of T lymphocytes with FcR+ MO, but not FcR- MO, led to the induction of T suppressor (Ts) cells that inhibited antigen-driven lymphoproliferation in the test cultures. These Ts cells were resistant to mitomycin C, belonged to afferent-acting category of Ts cells, expressed CD8 and HLA-DR determinants, and showed no antigenic specificity nor genetic restriction in action.

Unique Ia epitopes of T cells (Iat) are involved in the recognition of stimulator cells in the allo-MLR.

Anti-Iat monoclonal antibodies (mAbs) were found to block the recognition phase of allogeneic mixed lymphocyte reaction (allo-MLR) by reacting with responder T cells but not stimulators. The inhibitory pattern was dependent on the major histocompatibility complex (MHC) of both the responder and stimulator cells. Certain molecules, including IgVH and I-J of stimulator cells were also important.