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H W Boyce

Publications and source records attributed to H W Boyce.

80 records · Page 5Linked to original sources
PubMedDate not supplied

Evaluation of submucosal upper gastrointestinal tract lesions by endoscopic ultrasound.

The proper diagnosis of submucosal upper gastrointestinal tract mass lesions by endoscopy or barium study is difficult. Differentiation between submucosal tumors, vascular structures, and extrinsic organs is often impossible. We performed endoscopic ultrasound examination of 91 patients with upper gastrointestinal submucosal mass lesions. Endoscopic ultrasound was accurate in determining the site of origin in 48 of 50 cases where pathology or angiography comparison was available. Leiomyoma, lipoma, varices, and carcinoma had characteristic ultrasonographic findings. Endoscopic ultrasound is a useful procedure in the evaluation of upper gastrointestinal submucosal mass lesions.

Endoscopy, Gastrointestinal↗
PubMedDate not supplied

Stability of the B vitamins in mixed parenteral nutrition solution.

The effects of various light conditions such as fluorescent light, and indirect and direct sunlight on the stability of the water-soluble B vitamins in parenteral mixtures were studied. The levels of the B vitamins were determined by microbiologic assays and spectrophotometrically. Most of the B vitamins were found to be stable. However, indirect and direct sunlight destroyed 47 and 100%, respectively, of riboflavin-5-phosphate in eight hours. Direct sunlight destroyed 86% of pyridoxine HCl. There was no loss of folic acid in parenteral nutrition mixtures after storage for 7 wk. The microbiologic assays were found to be reliable to measure the levels of the B vitamins in parenteral nutrition solution.

Bacteria↗
PubMedDate not supplied

5-Fluorouracil cytotoxicity in human colon HT-29 cells with moderately increased or decreased cellular glutathione level.

Little is known whether diet or certain components in the diet can modulate the efficacy of 5-fluorouracil (5FU) in patients with colon carcinoma. Glutathione (GSH), an important antioxidant and anticarcinogen, is present in many foods in varying amounts. This study examined whether a moderately increased or decreased cellular GSH level had any effect on the growth of human colon adenocarcinoma cells HT-29 and on the cytotoxic activity of 5FU in these cells. GSH and buthionine sulfoximine were used to enhance or reduce the GSH level respectively in these cells. A 34% increase in cellular GSH level had no effect on the growth of HT-29 cells, nor on the cytotoxic activity of 5FU as determined by the MTT colorimetric assay and cell counts. A 50% reduction in the cellular GSH level was found to enhance 5FU cytotoxicity by 20% to 31% as determined by the MTT colorimetric assay, depending on the 5FU concentration. This study shows that a moderate change in the GSH level in HT-29 cells had little or no effect on the cells' growth, but a decrease in cellular GSH level slightly enhanced the cytotoxic activity of 5FU in these cells.

Adenocarcinoma↗