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Biomedical subjects

F Magallanes

Publications and source records attributed to F Magallanes.

5 recordsLinked to original sources
PubMed1985

The role of luminal pH in production of gastrin cell hyperplasia in the rat.

Truncal vagotomy is associated with diminished gastric acid production, gastrin cell hyperplasia, and elevated serum gastrin levels. To study the role of reduced antral luminal acidity in the production of gastrin cell proliferation, gastrin cell densities were quantitated in preparations involving exposure of the antral mucosa to a non-acid lumen at different levels of the gastrointestinal tract. Female Sprague-Dawley rats were divided into the following experimental groups: intact controls, shams, antral diverticulum on the jejunum, antral diverticulum on the ileum, and antral diverticulum on the colon. At death, 2 weeks, 2 months, and 6 months after operation, luminal pH was at least 5.8 for each group of rats with antral diverticula. No significant changes in gastrin cell numbers were observed in rats with jejunal or ileal diverticula. For those animals with colonic diverticula, gastrin cell counts were increased 55% at 2 weeks (503 +/- 23 cells per cm versus 320 +/- 13 cells per cm for shams). At 2 months gastrin cell numbers had increased further (639 +/- 54 cells per cm) in rats with antral diverticula on the colon. Gastrin cell proliferation was sustained at 6 months in this group. A factor other than reduced luminal acidity induces gastrin cell proliferation in antral mucosa exposed to colonic content. The responsible agent is not present in the small-bowel lumen. A non-acid luminal environment is not, by itself, a sufficient stimulus for gastrin cell hyperplasia.

Animals↗
PubMed1984

The results of aggressive regional operation in the treatment of cancer of the floor of the mouth.

We reviewed the records of 94 patients with cancer of the floor of the mouth who were treated during a 15-year period to assess the results of an aggressive regional surgical approach. The primary tumor was excised with a 2 cm margin of normal tissue. A marginal or segmental mandibulectomy was performed in 84 of 94 patients. An ipsilateral radical neck dissection was performed in 86 of 94 patients. Contralateral suprahyoid dissection was combined with ipsilateral radical neck dissection in 52 patients. Bilateral radical neck dissection was performed in 10 patients. In the 1 to 16-year follow-up period, local/regional control was achieved in 91% of stage I patients, 83% of stage II patients, 68% of stage III patients, and 48% of stage IV patients. Determinant 5-year survival rates were T1--72%, T2--47%, T3--25%, and T4--28%.

Adult↗
PubMed1983

In-continuity gastrointestinal stapling.

Several surgical procedures have been proposed to interrupt continuity of the gut, without transection, by means of a row of staples. Using the dog, we investigated the functional and histologic results of incontinuity stapling of the gastric antrum, the small intestine, and the colon. After creation of an end antrostomy, ileostomy, or colostomy, a staple line was placed proximal to the stoma (TA 55-4.8 mm staples). Decompression of the bowel proximal to the staple line was accomplished by an enteric anastomosis. Separation of the staple closure was detected by intestinal contents exiting from the stoma. Animals were sacrificed at the time of disruption, and specimens were obtained for histologic examination. Three of five antral closures broke down at a mean of 19.6 days after operation. All five small-bowel staple lines opened at a mean of 12.4 days. Five of five colonic staple lines disrupted 13.0 days postoperatively. The staples pulled through the bowel wall without losing their "B" shaped configuration. Microscopic examination showed intact mucosa across the staple line, with no submucosa to submucosa healing. Staple lines in the undivided small bowel or colon disrupt after approximately two weeks, due to lack of fibrotic healing. Staple interruptions of the gastric antrum also disrupt, but with less regularity.

Animals↗