Acquired resistance against a secondary infection with Listeria monocytogenes in mice is not dependent on reactive nitrogen intermediates.

During an infection, inflammatory mediators can induce the production of nitric oxide, a reactive nitrogen intermediate (RNI) which plays a role in antimicrobial activity against a wide variety of pathogens. In vitro experiments have shown that release of RNI by macrophages is mediated by tumor necrosis factor alpha (TNF). Since TNF is essential for acquired resistance during a secondary Listeria monocytogenes infection in mice, the aim of the present study was to determine whether RNI are also involved in the course of such an infection.

Increased production of nitric oxide correlates with viral load and activation of mononuclear phagocytes in HIV-infected patients.

The objective of our study was to determine the production of nitric oxide (NO) in patients infected with human immunodeficiency virus (HIV) and its relation to cellular immunity, activation of mononuclear phagocytes and the amount of circulating virus. Therefore, serum nitrate, the stable metabolite of NO, the number of peripheral CD4+ T-lmphocytes, serum neopterin, plasma HIV-RNA and HIV-DNA in peripheral blood mononuclear cells of afebrile HIV-infected patients were determined. Serum nitrate levels were significantly (p = 0.

Methylene blue increases myocardial function in septic shock.

Objective: To study whether the circulatory changes of human septic shock are mediated in part by nitric oxide.

Design: Open-label, nonrandomized clinical trial on the effects of methylene blue, an inhibitor of nitric oxide action.

Setting: Intensive care unit of a teaching hospital.

High levels of interleukin 10 and tumor necrosis factor alpha in cerebrospinal fluid during the onset of bacterial meningitis.

Since interleukin-10 (IL-10) controls the production of tumor necrosis factor alpha (TNF-alpha) and this latter cytokine has a deleterious effect on neuronal cells, we determined the levels of both cytokines in cerebrospinal fluid (CSF) from children with bacterial meningitis. High levels of IL-10 (1,164 pg/mL) and TNF-alpha (3,158 pg/mL) were detected in CSF from 10 children with meningitis, but these cytokines were not detectable in CSF from 12 controls. In vitro neutralization of IL-10 demonstrated that endogenously formed IL-10 is important for limiting the production of TNF-alpha by leukocytes.

Increased production of nitric oxide in patients infected with the European variant of hantavirus.

Serum nitrate levels, a measure of nitric oxide (NO) production in vivo, were very high (95 +/- 14 microM) in 13 patients infected with Puumala virus, the European variant of Hantavirus (HTV), as compared to those in healthy subjects (33 +/- 3 microM). Serum nitrate levels showed a high and significant correlation with scores on the Acute Physiological And Chronic Health Evaluation (APACHE II) scale and with serum creatinine, and an inverse correlation with platelet counts. Serial serum measurements of nitrate in 2 severe cases showed very high levels at the onset of arterial hypotension and acute renal failure.

How to determine control of growth rate in a chemostat. Using metabolic control analysis to resolve the paradox.

The chemostat makes it possible to study microbial physiology at steady state. However, because growth rate in a chemostat is set by the experimenter, it seems impossible to employ the chemostat to study the control of microbial growth by processes within the microorganism. In this paper we show how, paradoxically, one can determine control of growth rate, of growth yield and of other fluxes in a chemostat.

Transcription regulation of ribosomal protein genes at different growth rates in continuous cultures of Kluyveromyces yeasts.

We have investigated the relationship between the growth rate of two Kluyveromyces strains that differ in their maximum growth rate, namely K. lactis (mumax = 0.5 h-1) and K.

Growth-related expression of ribosomal protein genes in Saccharomyces cerevisiae.

The rate of ribosomal protein gene (rp-gene) transcription in yeast is accurately adjusted to the cellular requirement for ribosomes under various growth conditions. However, the molecular mechanisms underlying this co-ordinated transcriptional control have not yet been elucidated. Transcriptional activation of rp-genes is mediated through two different multifunctional transacting factors, ABF1 and RAP1.

[Generalized mastocytosis; to be considered following resuscitation].

This case report describes a male patient aged 44 with recurrent hypotensive shock and severe pulmonary obstruction. The diagnosis of systemic mastocytosis was suggested by the presence of small pigmented maculae (urticaria pigmentosa) and intolerance to NSAIDs. The diagnosis was confirmed by microscopic investigation of the pigmented maculae and bone.

The effects of bacterial lipopolysaccharide (LPS) on high endothelial venules and interdigitating cells in mouse lymph nodes.

Migration of lymphocytes into lymph nodes is directly controlled by interaction of lymphocytes with the high endothelial venules (HEV), located in T cell-dependent areas of lymph nodes. Little is known about the mechanisms that regulate the activity of the HEV and the specificity of interaction with lymphocytes in various lymphoid organs. It has been suggested that the non-lymphoid interdigitating cells (IDC) play a role in maintaining the integrity of T cell areas.

The role of macrophages in LPS-induced lethality and tissue injury.

In the present study we investigated the role of mononuclear phagocytes in the pathogenesis of lipopolysaccharide (LPS)-induced lethality and tissue injury. Since hepatic and splenic macrophages are the primary sites of localization of i.v.

Transcriptional control of yeast ribosomal protein synthesis during carbon-source upshift.

Shifting a yeast culture from an ethanol-based medium to a glucose-based medium causes a coordinate increase of the cellular levels of ribosomal protein mRNAs by about a factor 4 within 30 min. Making use of hybrid genes encompassing different portions of the 5'-flanking region of the L25-gene, we could show that the increase in mRNAs is a transcriptional event, mediated through DNA sequences upstream of the ribosomal protein (rp) genes. Further analysis revealed that sequence elements are involved that many rp-genes have in common and that previously were identified as transcription activation sites (RPG-boxes or UASrpg).

The differential effects of bacterial lipopolysaccharide (LPS) on splenic non-lymphoid cells demonstrated by monoclonal antibodies.

In the present study, the effect of LPS on different splenic non-lymphoid cells was investigated. Marginal zone (MZ) macrophages, marginal metallophils and interdigitating cells (IDC) were demonstrated using specific monoclonal antibodies in a two-step immunoperoxidase procedure in combination with enzyme histochemistry. The results indicate that the number of marginal zone macrophages decreases markedly after LPS treatment, but is followed by a rapid repopulation as observed by monoclonal antibody staining and selective uptake of FITC-Ficoll.

In vivo effects of toxic and detoxified endotoxin alone or in combination with muramyl dipeptide on lymphoid and non-lymphoid cells in the spleen of Meth A sarcoma-bearing mice.

In this study we confirmed that combinations of toxic or detoxified endotoxin with muramyl dipeptide (MDP) induced much more necrosis of transplanted Meth A sarcoma in mice than toxic endotoxin alone. Detoxified endotoxin and MDP alone had little antitumor effects. We investigated whether these divergent antitumor effects could be related to histopathological changes in the white pulp of the spleen of Meth A sarcoma-bearing mice.

In vivo effects of LPS on B lymphocyte subpopulations. Migration of marginal zone-lymphocytes and IgD-blast formation in the mouse spleen.

The aim of the present study was to analyze the effect of LPS on the localization and differentiation of splenic B lymphocytes. Therefore, we used a double immunoperoxidase technique which enabled us to detect both the IgM+ IgD- marginal zone lymphocytes and the IgM+ IgD+ follicular lymphocytes in the same tissue section. Next to a dramatic disappearance of the predominantly IgM+ IgD- lymphocytes in the marginal zone shortly after an intravenous injection of LPS, an increased number of these cells could be found in the splenic follicles.

The effects of LPS on the cellular composition of the splenic white pulp in responder C3H/He and non-responder C3H/HeJ mice.

The aim of the present study was to compare the effects of LPS on the cellular composition of the splenic white pulp in responder C3H/He and non-responder C3H/HeJ mice. The present results show that an intravenous injection of LPS in C3H/He mice results in a number of prominent changes in the histology of the spleen, but none of these histological changes could be demonstrated in the unresponsive C3H/HeJ mice. However, the present study shows that LPS administration resulted in the disappearance of previously trapped immune complexes from the follicles in both responder C3H/He and non-responder C3H/HeJ mice.

Localization of intravenously injected lipopolysaccharide (LPS) in the spleen of the mouse. An immunoperoxidase and histochemical study.

In earlier studies we investigated the in vivo effects of lipopolysaccharide (LPS) on lymphoid and non-lymphoid cells in the mouse spleen. In order to find out whether LPS localizes in and/or on cells that are affected by this compound, the aim of the present study was to investigate the localization of intravenously injected LPS in the mouse spleen using an immunoperoxidase technique. At different time points after injection, the localization of LPS is demonstrated and LPS-containing cells are characterized.