Biomedical subjects

J Riese

Publications and source records attributed to J Riese.

22 records · Page 2Linked to original sources

PubMed1994

Transient expression of prostaglandin endoperoxide synthase-2 during mouse macrophage activation.

We investigated regulation of macrophage prostaglandin production during activation by interferon gamma (IFN-gamma) and lipopolysaccharide (LPS). An in vitro model was established using the mouse macrophage-like cell line RAW 264.7. Cells were cultivated in the presence of IFN-gamma and LPS for up to 48 h and changes in the secretion of nitric oxide (NO.) and tumor necrosis factor alpha (TNF-alpha) were observed as activation markers. Under these conditions a prompt and strong increase in PGE2 production was found in the first 8 h followed by nearly constant generation of PGE2 during the next 40 h. In contrast, the activity of prostaglandin endoperoxide synthase (PGHS), measured as PGE2 production of microsomal protein fractions, was also increased, but reached a clear maximum at 24 h. Recently a second form of PGHS was cloned (PGHS-2) and specific antibodies and mRNA probes for both isoforms are available. PGHS-2 enzyme was expressed maximally after 24 h of activation whereas PGHS-1 was not influenced. In the presence of IFN-gamma and LPS, PGHS-2 mRNA expression reached a maximum at 8 h but PGHS-1 mRNA was not induced during the whole time period. These data indicate that changes in PG synthesis following macrophage activation are due to regulation of PGHS-2 expression.

Animals↗

PubMed1994

Impairment of macrophage eicosanoid and nitric oxide production by an alkaloid from Sinomenium acutum.

The effects of sinomenine (7,8-didehydro-4-hydroxy-3,7-dimethoxy-17-methyl- 9 alpha,13 alpha,14 alpha-morphinan-6-one), a pure alkaloid extracted from the Chinese medical plant Sinomenium acutum, on different macrophage capacities were investigated in vitro using resident mouse peritoneal macrophages and the macrophage-like cell line RAW 264.7. Sinomenine markedly decreased prostaglandin E2 and leukotriene C4 synthesis of macrophages stimulated by zymosan or calcium ionophore and also significantly inhibited the nitric oxide production of RAW 264.7 cells activated by interferon-gamma/lipopolysaccharide. It can be considered that these effects are part of the analgesic, anti-inflammatory, and antirheumatic mechanisms of sinomenine.

Alkaloids↗

PubMedDate not supplied

Culture of human peritoneum--a new method to measure the local cytokine response and the effect of immunomodulators.

The production of cytokines and chemokines, which are involved in cell activation and cell migration in native pieces of peritoneum, was measured to investigate immune regulatory reactions in the human peritoneum. The samples were obtained during abdominal surgery and cultured immediately afterwards. In order to test therapeutic options in vitro, the effect of IL-10 and IFN-gamma on the cytokine and chemokine production was also studied. The chemokine monocyte chemotactic protein-1 (MCP-1) was produced and released spontaneously. When lipopolysaccharide (LPS) was added, MCP-1 production increased. In addition, TNF-alpha production was induced by LPS. When IL-10 was added, LPS-stimulated TNF-alpha production was reduced towards baseline levels, LPS-induced MCP-1 production was reduced by 37%. IFN-gamma did not affect LPS-induced TNF-alpha and MCP-1 production, but increased baseline MCP-1 production. It can be concluded that short-time culture of native human peritoneum is a method to investigate peritoneal chemokine and cytokine production in patients undergoing abdominal surgery. Further studies are intended to detect cytokine patterns which identify patients at risk of developing peritonitis. In addition, the effects of medications may be tested in vitro in order to investigate options for preventive modulation of the peritoneal immune response in such patients.

Abdomen↗

PubMedDate not supplied

Depression of tumor necrosis factor-alpha, interleukin-6, and interleukin-10 production: a reaction to the initial systemic hyperactivation in septic shock.

Sepsis remains a major cause of mortality in surgical intensive care units. Patients who survive the initial shock phase but die weeks later from multiple organ dysfunction still are a challenge to basic and clinical research. We addressed whether fulminant sepsis results in rapid changes (24 h) in the cellular capacity to produce cytokines in whole blood of septic patients on further stimulation after the initial systemic inflammatory response. Interleukin (IL)-6 plasma concentrations from 279 pg/mL to 5979 pg/mL confirmed the presence of a systemic inflammatory response. Anti-inflammatory IL-10 concentrations up to 275 pg/mL were detected, but there was no biologically active tumor necrosis factor-alpha (TNFalpha) detectable (by bioassay) at the time of investigation. On stimulation with Escherichia coli ex vivo, pro-inflammatory TNFalpha (130 pg/mL), IL-6 (4061 pg/mL), and anti-inflammatory IL-10 (711 pg/mL) production were markedly depressed in all patients compared with controls (2339 pg/mL, 50,319 pg/mL, and 9654 pg/mL, respectively). Septic shock resulted in early depression of the capacity for pro- and anti-inflammatory cytokine production. Monitoring of this effect, including its relationship to outcome, may offer a target variable for therapeutic efforts to maintain or restore adequate immune reactions to improve survival.

Adult↗