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Biomedical subjects

M Moser

Publications and source records attributed to M Moser.

At least 253 records · Page 14Linked to original sources
PubMed1991

Hyper IgE in stimulatory graft-versus-host disease: role of interleukin-4.

Intravenous injection of 2 x 10(8) DBA/2 spleen cells into adult intact (C57BL/6 x DBA/2) F1 mice results in a stimulatory graft-versus-host reaction (GVHR) linked to the recognition by donor CD4+ T cells of Ia alloantigens on host B cells. In the experiments presented here, we found that this GVHR is associated with a major increase in IgE serum levels which was already present 7 days after the cell transfer. At 6 weeks, mean IgE levels were more than 200-fold above the control values. Host B cells were responsible for the hypersecretion of IgE in stimulatory GVHR since it was also observed when the DBA/2 donor inoculum was depleted of B cells but not when the F1 recipients were irradiated. The induction of IgE secretion required donor CD4+ T cells as treatment of the donor inoculum with lytic anti-CD4 monoclonal antibody (MoAb) completely prevented the occurrence of the hyper IgE whereas depletion of CD8+ cells had no influence on this parameter. The role played by interleukin-4 (IL-4) in this model was analysed in vivo by the administration of the 11B11 anti-IL-4 rat MoAb (total dose 36 mg) during the first 12 days following induction of stimulatory GVHR by 8 x 10(7) DBA/2 spleen cells. This treatment completely prevented the development of hyper IgE whereas the administration of a control rat MoAb had no significant effect. We conclude that stimulatory GVHR in mice is associated with a major increase in serum IgE which is mediated by IL-4.

Animals↗
PubMed1991

Modulation of murine host-versus-graft disease by anti-CD3 monoclonal antibody.

BALB/c mice made tolerant to A/J alloantigens by neonatal injection of (A/J x BALB/c)F1 spleen cells develop a host-versus-graft (HVG) disease due to the activation of donor B cells by a subset of host alloreactive helper T cells. We have investigated the effects of a single neonatal injection of the 145-2C11 anti-mouse CD3 monoclonal antibody (MoAb) on the establishment of allotolerance and on the development of the immunopathological features of HVG disease. First, this treatment did not modify the specific anti-donor cytotoxic T lymphocyte (CTL) unresponsiveness or the persistence of circulating immunoglobulins bearing donor allotype. Second, the hyper IgE, the hyper IgG1 and the increased expression of Ia antigens on B cells found in untreated HVG mice were not observed after injection of the 145-2C11 MoAb. Likewise, treated mice displayed lower levels of anti-DNA IgG antibodies and less glomerular immune deposits as compared with untreated HVG mice. We conclude that the administration of the anti-CD3 MoAb did not interfere with the induction of allotolerance but exerts a pronounced inhibitory effect on the associated immunopathological syndrome.

Animals↗
PubMed1991

Influence of iodide on cataractogenesis in Emory mice.

Cataract development was studied in two groups of Emory mice by periodical biomicroscopic examinations (beginning at 5 weeks of age) and by a final evaluation of water-soluble SH groups in the lenses. The experimental group was given 256 micrograms iodide/kg body weight with the drinking water throughout the study. The untreated control group received tap water. Iodide treatment induced a delay of cataract formation, resulting in a significant reduction of the time to progress from cataract degree 1 to degree 2 (iodide-treated group 12.8 +/- 1.7 weeks, untreated group 9.9 +/- 1.0 weeks; p less than 0.025). A still significant difference in the degree of cataract was also found between the two groups at week 47 of age. No difference was found in the content of water-soluble SH groups. The results are discussed in relation to the known antioxidant and .OH-scavenging effect of iodide and to the oxidative changes in the lens occurring during progression of cataract development.

Administration, Oral↗
PubMed1991

The effects of periodic eutrophication on parasitism and stock identification of Trematomus bernacchii (Pisces: Nototheniidae) in McMurdo Sound, Antarctica.

McMurdo Sound, Antarctica, is suited for the study of the effects of eutrophication on diet-related parasites of Trematomus bernacchii (Boulenger, 1902) (Pisces). It has been relatively well studied, the environment is predictable, and there are significant differences in primary productivity over small distances. The differences in parasitism for 5 helminth species can be attributed to the enrichment processes in the sound. The prevalences of the acanthocephalan Echinorhynchus sp., the nematode Ascarophis nototheniae, the digenean Dinosoma sp., and the cestode Phyllobothrium sp. are significantly higher on the east side of the sound than on the west. The prevalence of the digenean Lepidepedon garrardi was significantly higher on the west side. We believe that the differences in the prevalences of infection between the east and west sides suggest that at least the benthic, adult fish do not readily move from one side of the sound to the other. We report the following (new host records are marked by asterisks): Echinorhynchus sp., Corynosoma hamanni (Acanthocephala); Phyllobothrium sp., Diphyllobothrium sp., Trypanorhyncha (Cestoidea); Clavellopsis (Copepoda); Dinosoma sp., Lepidepedon garrardi (Digenea); Pseudobenedenoides brachicola, Polyopisthocotylea (Monogenea); Contracaecum sp., Ascarophis nototheniae (Nematoda); Myxoproteus sp., Henneguya sp., Ceratomyxa sp., and Zschokkella sp. (Protozoa).

Animals↗
PubMed1991

The measurement of blood density to investigate protein deposition at the blood/hollow fiber membrane interface during ultrafiltration.

Concentration polarization and secondary membrane formation change the membrane hydraulic permeability of capillary filters during hemofiltration reducing initial value filtration rates up to 50%. This leads to a significant loss of filter efficiency which must be taken into consideration when designing filters for long-term application such as in implantable artificial kidneys. By measuring blood density uninterrupted over a period of time using the mechanical oscillatory technique it is possible to follow the dynamics of protein deposition at the interface between the blood and capillary walls. The resulting picture of the deposition behaviour can lead to a better understanding of time-dependent filtration where flow and pressure conditions change. Protein deposition (Pt) with polysulfone membranes in relation to the effective capillary surface was in the range of 2.2. mg/(h x cm2) according to a logarithmic function (Pt = a + b x log(t)).

Animals↗
PubMed1991

Controversies in hypertension management.

There are numerous questions regarding the benefits of hypertension treatment on coronary heart disease mortality and controversies regarding the most appropriate choice of initial antihypetensive monotherapy. In this article, data are reviewed to clarify some of these controversies and present six conclusions to apply to hypertension therapy.

Antihypertensive Agents↗
PubMed1991

[Influence of an iodine-drinking cure on the antioxidative status of diabetic patients].

The influence of a 4 week course of balneotherapeutic treatment in Bad Hall on different blood parameters and on the activity of the antioxidative enzymes glutathione peroxidase (GSH-Px), catalase and superoxide dismutase (SOD) was examined in diabetics. The patients were divided into 2 groups. One group underwent an iodine-balneotherapeutic programme (therapeutic exercises, baths, packages, inhalations), the other group additionally received an iodine brine drinking cure. At the end of the cure, the cholesterol, triglyceride and glucose levels had fallen to normal values in both groups due to the diabetic diet and, if required, drug therapy. Erythrocyte SOD was also reduced in both groups. Plasma catalase and plasma GSH-Px were significantly raised only in the group drinking iodine brine, while erythrocyte GSH-Px and the amount of the lipid peroxidation product malonyl dialdehyde were unchanged. The observed improvements in the parameters are considered unspecific cure effects, which lead to a desirable normalisation and homogenisation. Only the enhancement of plasma GSH-Px activity can be interpreted as an iodine specific cure effect.

Administration, Oral↗
PubMed1990

[Health hazards associated with flying and diving. ENT aspects].

The popularity of scuba diving among the general public and the great increase in air travel are increasingly associated with health problems. In the ENT sector, such problems mainly take the form of barotrauma that can arise from changes in the volume of gases enclosed within body cavities, due to fluctuations in pressure during diving and air travel. More rarely, decompression illness can occur when the required time for decompression is ignored by a diver coming up to the surface, or when a sudden loss of pressure occurs in the cabin of a plane, leading to the liberation of nitrogen dissolved in body fluids. Pathomechanisms, symptoms and treatment of barotrauma affecting the middle and inner ear and the sinuses, together with the effects of decompression errors on the organs of hearing and balance, are described, and suggestions for their prevention given. Fitness for diving and air travel, together with diseases that render these inadvisable, are discussed.

Aerospace Medicine↗
PubMed1990

Immune surveillance: both CD3+ CD4+ and CD3+ CD8+ T cells control in vivo growth of P815 mastocytoma.

The aim of this study was to examine whether a spontaneous immune response controls neoplastic growth in P815-bearing DBA/2 mice, and to characterize the cells involved in tumor resistance in vivo. Several cell lineages such as T-cell-receptor (TcR)-bearing T cells, NK cells and macrophages mediate some anti-tumor activity in vitro. P815 was chosen as a model because it is weakly immunogenic and is a good target both for tumor-specific, MHC-restricted CTL-mediated lysis and for MHC-unrestricted lysis exerted by long-term cultured lymphocytes or activated macrophages. Since most "NK-like activity" in freshly isolated populations appears to be associated with CD3- cells, whereas antigen-specific, MHC-restricted T cells mostly express CD3 determinants, CD3 was a good marker for evaluating the role of T cells and "NK" cells in tumor resistance in vivo. The survival of anti-CD3-treated animals that were inoculated with tumor cells was strongly reduced (mean survival time: 17 days vs. 40 days for the control group) and was associated with increased tumor growth rate. We followed the same approach to define the T-cell subset(s) that mediate(s) this immune response. Both CD4+ and CD8+ T cells were required for induction of immune control on neoplastic growth. The approach used has revealed the important role of CD4+ T cells in immune responses that control in vivo growth of a class-I-positive, class-II-negative tumor and suggests that these cells may play a central role in tumor resistance. Since CD4+ cells are activated by soluble, exogenous proteins, this finding may have important implications for immunotherapy.

Animals↗
PubMed1990

Anti-CD3 antibodies induce T cells from unprimed animals to secrete IL-4 both in vitro and in vivo.

Recently, functional heterogeneity among Th cells has been recognized. Based on pattern of lymphokine secretion, two mutually exclusive subsets of CD4+ cells have been defined and designated Th1 (secreting IL-2 and IFN-gamma) and Th2 (secreting IL-4 and IL-5). Identification of these subsets was mostly based on the study of long term cultured T cell lines and clones, and little is known about the Th heterogeneity in vivo. In particular, it has been suggested that IL-4 producing cells cannot be detected in vivo or in primary stimulations in vitro unless responder cells had been previously primed. Our data however, indicate that anti-CD3 mediated stimulation can induce T cells isolated from unprimed animals to IL-4 production. An assay system based on the ability of IL-4 to increase Ia expression of B cells present in the environment of activated T cells was found to be more sensitive than detection of secreted IL-4 in the supernatant by conventional bioassays and was used to study IL-4 production by unprimed lymphocytes polyclonally stimulated in vivo and in vitro by anti-CD3 mAb. The results obtained indicate that CD4+ CD8- T cells able to produce IL-4 upon receptor-specific stimulation exist in the preimmune pool of adult animals. Remarkably, these cells can also be stimulated in vivo by treating animals with anti-CD3 mAb, as indicated by the in vivo induction of IL-4 specific mRNA and hyper-Ia expression on B cells. These results indicate that the inability to detect IL-4 in primary cultures is not due to different activation requirements of Th2 cells but may simply result from their lower frequency in unprimed animals.

Animals↗
PubMed1990

Evidence for a role of translational frameshifting in the expression of transposition activity of the bacterial insertion element IS1.

The bacterial insertion element IS1 contains two essential open reading frames, insA and insB, arranged in tandem. We have introduced a number of site-specific mutations into the region including the 3'-terminal region of insA, the region between insA and insB, and the ATG codon at the start of insB. Relative transposition activities of mutant and wild-type elements were determined using a modified in vivo cointegration assay. The results support the hypothesis that a translational (-1) frameshift occurring in the 3'-terminal region of insA and linking insB to insA is responsible for the synthesis of the active IS1 transposition enzyme. Further results with IS1 elements containing internal deletions are in agreement with a role of the normally terminated insA product as an inhibitor of transposition.

Amino Acid Sequence↗
PubMed1990

Hypertension treatment results in minority patients.

The limited data available from the long-term clinical trials on the treatment of hypertension, as well as several short-term studies, indicate that the lowering of blood pressure in minority patients is feasible over the long term with a marked decrease in morbidity and mortality. The presence of left ventricular hypertrophy and diabetes in a higher number of black compared with white patients does not appear to be a major determining factor in the choice of initial monotherapy. Studies have established that the blood pressure-lowering effects of thiazide diuretics and calcium entry blockers or converting enzyme inhibitors. When these latter agents are added to a diuretic, however, a good blood pressure response is achieved. There are few data available on the results of long-term treatment in Asian or Hispanic persons.

Black or African American↗
PubMed1990

[Air pollution and sudden infant death in Graz 1982 to 1987].

We correlated the incidence of the sudden infant death syndrome (SIDS) and the degree of air pollution in each district of Graz over a time period of five years. The degree of air pollution was derived from a mapping of epiphytical lichen vegetation by Grill et al. (1988). We found an increased incidence of SIDS in districts with poor air quality. Although this result is not statistically significant a possible increase in SIDS risk because of air pollution cannot be excluded. Some pathophysiological explanations are discussed.

Air Pollution↗
PubMed1990

Hypothermia and hypoglycemia induced by anti-CD3 monoclonal antibody in mice: role of tumor necrosis factor.

The possible involvement of tumor necrosis factor-alpha (TNF) in the metabolic disturbances induced by anti-CD3 monoclonal antibodies (mAb) was analyzed in DBA/2 mice injected with 50 micrograms of the anti-murine CD3 mAb 145-2C11. First, we found that 145-2C11 induces a profound hypothermia maximal between 3 h and 6 h after the injection (at 3 h: -3.0 +/- 0.1 degrees C) as well as hypoglycemia (blood glucose levels at 6 h and 24 h: 76 +/- 13 mg/100 ml and 92 +/- 22 mg/100 ml, respectively, p less than 0.001 as compared with control values). These metabolic changes are preceded by the release of TNF into the circulation (peak serum TNF levels at 2 h: 50 +/- 23 pg/ml, p less than 0.01 as compared with controls). The release of TNF induced by 145-2C11 depends on the effect of the mAb on T cells as it is not observed in athymic nude mice while lipopolysaccharide-resistant C3H/HeJ mice also display a significant rise in serum TNF (peak levels at 2 h: 59 +/- 44 pg/ml). Pretreatment of DBA/2 mice with 12 mg of rabbit anti-murine TNF antibodies completely prevents the hypothermia while the hypoglycemia is significantly attenuated. Finally, F(ab')2 fragments of 145-2C11 induce only a transient hypoglycemia (blood glucose levels at 6 h: 109 +/- 14, p less than 0.001 as compared with controls) but neither hypothermia nor significant TNF release. We conclude that TNF is a major mediator of the acute metabolic changes induced by the intact form of 145-2C11.

Animals↗
PubMed1990

Do different hemodynamic effects of antihypertensive drugs translate into different safety profiles?

Various antihypertensive drugs reduce blood pressure by different mechanisms. In some instances, adverse reactions occur because of specific hemodynamic effects. Examples include syncope with alpha-blockade or vasodilator therapy; fatigue or exercise intolerance with the reduction in cardiac output following the use of beta-adrenergic inhibitors; edema, headaches, or dizziness with the use of vasodilators such as calcium entry blockers; renal failure in patients with renal artery stenosis or renal insufficiency following the use of ACE inhibitors; and marked hyponatremia with volume depletion following the use of diuretics, especially in elderly patients. In the majority of patients, however, blood pressure lowering can be achieved without significant adverse effects. Combining small doses of different agents with different hemodynamic actions often results in good blood pressure control and minimal reactions. Examples of these include diuretics and beta-adrenergic inhibitors, diuretics and ACE inhibitors, and beta-blockers and vasodilators.

Animals↗