PubMed Health⌕ Search

Biomedical subjects

U Opitz

Publications and source records attributed to U Opitz.

25 records · Page 2Linked to original sources
PubMed1977

Erythroid stem cells in Rauscher virusinfected mice.

Using the technique for erythroid colony formation in vitro, bone marrow and spleen cells from NMRI mice were studied after Rauscher virus (RLV) infection. There was a substantial decrease in CFUE concentrations during the first days after infection, this being more pronounced in the marrow than in the spleen. In the marrow values gradually return to and are maintained at control levels, while in the spleen a 40-50-fold increase is seen between days 8 and 18. In normal and RLV infected animals the same dose dependence of CFUE growth for erythropoietin was seen. For normal and RLV infected cells in the absence of erythropoietin there were only very few background colonies. In exhypoxic plethoric mice the increase in CFUE concentration seen in normal mice in the spleen, is delayed by 2-3 days.

Animals↗
PubMed1977

The role of fetal calf serum in the primary immune response in vitro.

The mode of action of 2-mercaptoethanol (2-ME) on the primary immune response in vitro was investigated. Fetal calf serum (FCS) was preincubated with 2-ME and lyophilized to remove free 2-ME. This 2-ME-treated FCS was able to substitute the function of adherent cells in the primary immune response against sheep red blood cells (SRBC) in vitro; Fractionation of 2-tme-treated FCS on a Sephadex G-100 column showed that 2-ME acted on a high molecular serum component which after activation, could substitute for macrophages. In order to obtain a humoral immune response against SRBC in vitro, spleen cells require selected FCS. These "good" sera could be distinguished from "deficient" sera by their higher content of this 2-ME-activated factor. The height of the in vitro immune response to SRBC was dependent on the amount of activated factor added to the culture medium. FCS normally required in the culture medium could be completely replaced by the factor-containing fraction without deleterious effect on the culture medium. The factor should be added to the spleen cells during the first 24 h of culture and remain there for 72 h in order to obtain an optimal immune response. The factor could be partially absorbed by spleen cells but not by SRBC. The relationship between macrophage, 2-ME, and FCS in eliciting an in vitro primary immune response is discussed.

Antibody Formation↗
PubMed1977

Humoral primary immune response in vitro in a homologous mouse system: replacement of fetal calf serum by a 2-mercaptoethanol or macrophage-activated fraction of mouse serum.

The primary immune response in mouse spleen cell cultures against heterologous red cell antigens is dependent on the medium being supplemented with selected batches of fetal calf serum. Mouse serum itself is not able to support this response. The active immune response-supporting component in fetal calf serum seems to be a distinct factor (s), which has been partially purified by Sephadex G-100 filtration and termed MaSF-2-mercaptoethanol-activated serum factor. In this report it is demonstrated that MaSF is also present in mouse serum. For functional detection, mouse MaSF has to be separated from higher m.w. inhibitors, and has to be activated by 2-ME. After separation and activation mouse MaSF can support the primary immune response in a completely homologous in vitro culture system. Evidence is presented that MaSF can also be activated by macrophages. It is concluded that macrophages and 2-ME have the same mode of action in the primary immune response in vitro, i.e., induction of lymphocyte competence by activation of a serum factor.

Animals↗
PubMed1976

Polyclonal stimulation of lymphocytes by macrophages.

To analyze the interaction between macrophages and splenic lymphocytes with reference to time and concentration, the Mishell-Dutton system was divided into two experimental steps. Step 1 consisted of the cocultivation of spleen cells with various doses of macrophages for different periods of time, while in step 2 macrophages were removed, spleen cells transferred to fresh petri dishes and cultivated until plaque assay. Cocultivation of spleen cells with high doses of macrophages for 4--8 h markedly enhanced the DNA synthesis and plaque-forming cell (PFC) response of sheep red blood cell-stimulated and unstimulated cultures. A cocultivation longer than 24 h resulted in an inhibition of both DNA synthesis and PFC response of spleen cells. These studies suggest a nonspecific function of macrophages on proliferation and differentiation processes in antibody formation.

Animals↗
PubMedDate not supplied

[Coping with illness by young diabetic patients: a comparison from the viewpoint of patients, their parents and personal physicians].

108 adolescents with type 1 diabetes as well as their parents and physicians in charge were studied in a prospective longitudinal design. Most of the juvenile patients were of good metabolic control. The results from different questionnaires of coping are presented. The opinions of the patients, their parents and the physicians in charge differ in some important aspects. Furthermore there are significant differences between the patients of best versus worst metabolic control as far as the extent of self reported psychosocial problems related with the disease is concerned.

Adaptation, Psychological↗