PubMed Health⌕ Search

Biomedical subjects

D R Mack

Publications and source records attributed to D R Mack.

40 records · Page 3Linked to original sources

Functional heterogeneity of colonic adenocarcinoma mucins for inhibition of Entamoeba histolytica adherence to target cells.

Mucins secreted from the gastrointestinal epithelium from the basis of the adherent mucus layer which is the host's first line of defense against invasion by Entamoeba histolytica. Galactose and N-acetyl-D-galactosamine residues of mucins specifically inhibit binding of the amebic 170 kDa heavy subunit Gal-lectin to target cells, an absolute prerequisite for pathogenesis. Herein we characterized the secretory mucins isolated from the human colon and from three human colonic adenocarcinoma cell lines: two with goblet cell-like (LS174T and T84) and one with absorptive cell-like morphology (Caco-2). By Northern blot analysis the intestinal mucin genes MUC2 and MUC3 were constitutively expressed by confluent LS174T and Caco-2 cells, whereas T84 cells only transcribed MUC2 and not MUC3 mRNA. 3H-glucosamine and 3H-threonine metabolically labeled proteins separated as high M, mucins in the void (Vo > 10(6) Da) of Sepharose-4B column chromatography and remained in the stacking gel of SDS-PAGE as depicted by fluorography. All mucin preparations contained high amounts of N-acetyl-glucosamine, galactose, N-acetyl-galactosamine, fucose and sialic acid, saccharides typical of the O-linked carbohydrate side chains. Mucin samples from the human colon and from LS174T and Caco-2 cells inhibited E. histolytica adherence to chinese hamster ovary cells, whereas mucins from T84 cells did not. These results suggest that genetic heterogeneity and/or posttranslational modification in glycosylation of colonic mucins can affect specific epithelial barrier function against intestinal pathogens.

Adenocarcinoma, Mucinous↗

An analysis of anterior cruciate ligament reconstruction in middle-aged patients.

The purpose of this study was to evaluate the results and complications of anterior cruciate ligament surgery in middle-aged patients. Forty-five consecutive patients over 40 years old (average age, 44.6 years) who had arthroscopically assisted anterior cruciate ligament reconstructions with midthird patellar tendon autografts were evaluated. The patients returned for interviews, physical examinations, radiographs, Biodex dynamometer strength testing, and KT-1000 arthrometer testing at an average of 37 months after their surgeries (range, 24 to 96 months). The mean Lysholm and Gillquist score was 91, which corresponds to symptoms only with vigorous activity. The overall scores from the International Knee Documentation Committee form were 29 (64%) normal or nearly normal and 2 (4%) severely abnormal. Side-to-side differences as determined by the KT-1000 arthrometer were < or = 3 mm in 31 of 40 patients (78%), between 3 and 5 mm in 4 patients (10%), and > 5 mm in 5 patients at 30 pounds of anterior displacement. Seventy-six percent of the patients (N = 34) returned to their preoperative activity levels. Three patients required repeat arthroscopic surgery for persistent knee pain and two patients had graft ruptures. This study shows that when middle-aged patients undergo surgery, their results can be successful and satisfying to a degree similar to those of younger patients.

Adult↗