PubMed Health⌕ Search

Biomedical subjects

K Heitmann

Publications and source records attributed to K Heitmann.

22 records · Page 2Linked to original sources

Lymphocyte proliferation in AIDS-related complex/Walter-Reed 5 patients: response to herpes simplex virus and tuberculin antigen and mitogen during intravenous immunoglobulin treatment. The ARC-IVIG Study Group.

In a randomized, controlled double-blind study, 15 patients with AIDS-related complex/Walter-Reed 5 (ARC/WR5) were compared during 6 months intravenous immunoglobulin (IVIG) treatment (0.4 g/kg body weight every 2 weeks) with 15 placebo-treated patients. This study was aimed at the lymphocyte response to T and B cell mitogens and antigens. 3H-thymidine uptake was determined after stimulation with the unspecific mitogens phytohemagglutinin (PHA), pokeweed mitogen (PWM), formalinized Staphylococcus aureus-Cowan I (SAC), and with the antigens tuberculin and herpes simplex virus (HSV) at the onset, on days 85, 183, 267 and 351; IgG and IgM antibodies against HSV were measured by ELISA. In addition, 30 untreated HIV-negative controls were tested. For the T cell mitogen PHA, T-cell-dependent B cell mitogen PWM and B cell mitogen SAC, no differences between the two patient groups were observed before therapy nor in the course of therapy or the 6-month observation period thereafter. The entire patient group showed significantly impaired mitogenic response on day 1 as compared to the controls. There was no significant difference in response to tuberculin between the patients and HIV-negative controls, nor for both patients groups before and in the course of treatment. All patients had IgG antibodies against HSV. Three of them showed blastogenic lymphocyte response to HSV on day 1. Among 19 seropositive controls, 7 individuals showed positive HSV lymphocyte response; but for both patient groups, there was no significant difference before and in the course of the treatment and observation period.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗

Characterization and histochemical localization of the rat intestinal Na(+)-D-glucose cotransporter by monoclonal antibodies.

The localization of the Na(+)-D-glucose cotransporter in rat small intestine was investigated with four monoclonal antibodies which were raised against porcine renal brush-border membrane proteins. The antibodies alter high affinity phlorizin binding or Na+ gradient-dependent D-glucose uptake in kidney and intestine. In both organs, the antibodies react with polypeptides with apparent molecular weights of 75,000 and 47,000. In pig kidney, these polypeptides were identified as components of the Na(+)-D-glucose cotransporter (Koepsell, H., K. Korn, A. Raszeja-Specht, S. Bernotat-Danielowski, D. Ollig, J. Biol. Chem. 263, 18419-18429 (1988)). The electron microscopic localization of antibody binding was investigated by immunogold labeling of ultrathin plastic sections. In villi and crypts of duodenum, jejunum and ileum the antibodies bound specifically to brush-border membranes of enterocytes and did not react with the basolateral membranes. The density of antigenic sites in brush-border membranes was highest in jejunum, intermediate in ileum and lowest in duodenum. On the tip, the middle and the basis of the villi the density of antigenic sites was similar. The data demonstrate homologous Na(+)-D-glucose cotransporters in kidney and intestine. They suggest that during maturation of the enterocytes when the total area of brush-border membrane increases, the concentration of the Na(+)-D-glucose cotransporter in the brush-border membrane remains constant. However, we found that different segments of small intestine not only contain different surface areas of the transporter-containing brush-border membrane per intestinal length but also different densities of the transporter within the brush-border membrane.

Animals↗

Electron-microscopic demonstration of the distribution of calcium deposits in the exocrine pancreas of the rat after application of carbachol, atropine, cholecystokinin, and procaine.

In an attempt to identify a cellular Ca2+-pool, from which calcium is released when secretagogues are applied, tissue fragments of the rat exocrine pancreas were incubated and fixed with glutaraldehyde in the presence of calcium. By means of this procedure electron-dense deposits were found on plasma membranes. X-ray microanalysis showed that these deposits contain calcium. Stimulation of tissue fragments with the use of the secretagogues carbachol or cholecystokinin reduced the number of deposits by about 80%. When the antagonist atropine was applied after carbachol stimulation, deposits reappeared on cell membranes, which then disappeared again after a second stimulation with cholecystokinin. In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes. These results suggest that a calcium pool, from which calcium is released to induce enzyme secretion on stimulation, is located in the cell membrane.

Animals↗