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Biomedical subjects

M L Chapman

Publications and source records attributed to M L Chapman.

31 records · Page 2Linked to original sources
PubMed1977

Acid absorption in the canine duodenum.

Alterations in composition of isosmotic acid solutions were studied in exteriorized segments of the proximal (Brunner's gland area) and distal canine duodenum, mounted in lucite chambers. Varying concentrations of HCl (40, 80, 120, 160 mEq/l) made isotonic by the addition of NaCl were instilled into the chamber, removed in 15 minutes and analyzed for volume, electrolytes, protein content and osmolality. Both proximal and distal duodenal mucosa modified the instilled solution with a loss of H+ and a gain in Na+ and K+, which occurred at similar rates independent of the acid concentration of the instilled solution. The rate of ionic movement was twice that for the antrum, and 30-100 times that of the fundus. Calculated H+ loss across the entire duodenal mucosa at these rates could account for 17.5% of the peak acid output from the canine stomach. The loss of H+ could not be accounted for on the basis of neutralization and probably represented transmucosal insorption. In addition to the neutralization of gastric acid by pancreatic juice and bile, duodenal mucosa thus plays an important role in the maintenance of intraluminal pH. Duodenal mucosal permeability to H+ may be related to the vulnerability of the duodenal mucosa to acid-peptic ulceration.

Animals↗
PubMed1976

Isolation of lymphocyte surface antigens. II. Identification of non-beta 2 -microglobulin-associated human T cell-specific antigen.

Iodinated cell surface components from human thymus lymphocytes labeled by the lactoperoxidase method, were solubilized by papain digestion and then 3 M KCl extraction of the residual cell pellet. Antiserum to human thymus bound three components from this material, mol. wt. approximately equal to 40 000, 20 000 and 12 000 daltons. This antiserum was absorbed with cultured human lymphoblasts (CHL) until it no longer bound CHL antigens or the HLA-beta 2-microglobulin complex. It continued to bind labeled antigens from thymus, peripheral blood lymphocytes and "T" cell-enriched fraction of tonsil lymphocytes. The absorbed antiserum bound a component from papain-solubilized thymus antigens which had an estimated molecular weight of approximately 40 000 daltons and which was not associated with beta 2-microglobulin. This component seemed to be a human T cell-specific antigen.

Antigens↗
PubMed1976

Lymphocyte plasma membranes. VI. Surface antigens of lymphocytes in chronic lymphocytic leukemia.

Surface antigens from lymphocytes of patients with chronic lymphocytic leukemia (CLL) and from normal peripheral blood lymphocytes (PBL) were examined by radioimmunoassay; antisera to lymphocytes (ALS) were used to bind the labeled antigens. Cells from patients with CLL, normal PBL, thymus cells (THY), and cultured human lymphoblasts (CHL) were labeled by lactoperoxidase-catalyzed iodination. ALS (prepared against THY and CHL) were used to bind the labeled antigens solubilized in nonionic detergent. PBL resembled THY, but the CLL resembled CHL. Thus ALS(CHL) had greater potency for CLL antigens than for PBL antigens when compared to ALS(THY). Furthermore, the electrophoretic profiles of the immunoprecipitates from CLL cells revealed a peak of approximately 30,000-35,000 mol wt, which was not found for PBL or THY, but was associated with CHL.

Antigens, Neoplasm↗