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Biomedical subjects

C Gray

Publications and source records attributed to C Gray.

At least 217 records · Page 12Linked to original sources
PubMed1989

Aspiration of high-density barium contrast medium causing acute pulmonary inflammation--report of two fatal cases in elderly women with disordered swallowing.

Two cases are reported in which accidental inhalation of barium contrast medium occurred owing to disordered swallowing in elderly women. In each case there was a pulmonary inflammatory reaction followed within a few hours by death. Experimental and clinical reports of barium inhalation are reviewed and the hazard of aspiration of high density barium preparations in elderly and debilitated patients with dysphagia is emphasised. It is concluded that particular care should be taken in the radiological examination of such patients, and a suggested method for performing a contrast swallow in those who are liable to aspirate is described.

Acute Disease↗
PubMed1989

Proteinase and proteinase inhibitor localization in the human placenta.

Standard immunoperoxidase techniques were used to investigate the distribution of the intracellular proteinase cathepsin D, two serine proteinase inhibitors--alpha 1-antitrypsin (alpha 1-AT) and alpha 1-antichymotrypsin (alpha 1-AChy)--and plasma fibrin stabilizing factor XIII (FXIII) in paraffin-embedded tissues from early and late intrauterine pregnancy and ectopic pregnancy. Localization of cathepsin D, alpha 1-AT, and alpha 1-AChy was identical in ectopic and intrauterine gestation: there was labeling of villous syncytiotrophoblast and a proportion of Hofbauer cells but no labeling of villous cytotrophoblast. The majority of interstitial extravillous trophoblast yielded negative results, but alpha 1-AT and alpha 1-AChy were consistently demonstrated in endovascular trophoblast. FXIII was not found in any trophoblast population but was demonstrated in Hofbauer cells, stromal fibroblasts, and interstitial dendritic cells. Granular, extracellular FXIII reactivity was present among sheets of infiltrating extravillous trophoblast in ectopic pregnancy but only occasionally in early intrauterine pregnancy. The results document further the heterogeneity of trophoblast, with the endovascular trophoblast forming an immunophenotypically distinct population. Furthermore, the pattern of extravillous trophoblastic invasion of maternal tissues in ectopic pregnancy appears to differ from intrauterine pregnancy; the poor decidualization of tubal mucosa in ectopic pregnancy may play a role in this variation.

Antibodies, Monoclonal↗
PubMed1989

Morphometric diagnosis of serous effusions: refinement of differences between benign and malignant cases by use of outlying values and larger sample size.

Fifty cytologically malignant, five suspicious, and 27 cytologically benign serous effusions were assessed morphometrically for differences in mean and outlying nuclear and cytoplasmic variables. Significant differences were found between benign and malignant specimens for all nuclear morphometric variables measured, the most significant being largest nuclear area and diameter. No significant differences were found for cytoplasmic size variables. Although measurement of outlying values in serous effusions enhanced the difference between benign and malignant cell populations, it was of insufficient sensitivity or specificity to be of clinical diagnostic use. Increasing the sample size improved test performance but would be tedious to perform manually.

Ascitic Fluid↗
PubMed1989

pH-dependent effects of the ionophore nigericin on response of mammalian cells to radiation and heat treatment.

The extracellular pH (pHe) in many solid tumors is often lower than the pH of normal tissues. The K+/H+ ionophore nigericin is toxic to CHO cells when pHe is below but not above 6.5, and thus it has potential for selective killing of tumor cells in an acidic environment. This study examines the pH-dependent effects of nigericin on the response of CHO cells to radiation and heat treatment. Cells held for 4 h in Hank's balanced salt solution, after 9 Gy irradiation, exhibit potentially lethal damage recovery (PLDR) which is maximal at pHe 6.7-6.8. Addition of nigericin, postirradiation, not only inhibits PLDR when pHe is below 6.8, but interacts synergistically with radiation to reduce survival below that of cells plated immediately after irradiation when pHe is 6.4 or lower. Nigericin enhances heat killing of CHO cells perferentially under acidic conditions, and where neither heat nor drug treatment alone is significantly toxic. Survival of cells held for 30 min at 42.1 degrees C in the presence of 1.0 microgram/ml nigericin is 0.6, 0.08, 0.003, and 0.00003 at pHe 7.4, 6.8, 6.6, and 6.4, respectively, relative to survival of 1.0 in untreated cultures. The biochemical effects of nigericin at pHe 7.4 vs pHe 6.4 have been investigated. Nigericin inhibits respiration, stimulates glucose consumption, and causes dramatic changes in intracellular concentrations of Na+ and K+ at pHe 7.4 as well as 6.4. The drug reduces intracellular levels of ATP, GTP, and ADP but has more pronounced effects under acidic incubation conditions. Others have shown that nigericin equilibrates pHe and intracellular pH (pHi) only when pHe is 6.5 or lower. Our observations and those of others have led us to conclude that lowering of pHi by nigericin is either the direct or indirect cause of enhancement of radiation and heat killing of cells in an acidic environment.

Animals↗