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Biomedical subjects

H W Boyce

Publications and source records attributed to H W Boyce.

At least 37 records · Page 2Linked to original sources

A new objective measurement of esophageal lumen patency.

This study was performed to develop a system to measure dysphagia in an objective fashion, test its correlation with subjective estimates of dysphagia, and encourage the use of a standardized measure of esophageal stenosis. Thirty-five patients with mechanical dysphagia underwent subjective estimates of dysphagia using a dysphagia scale graded from 0 to 5, as well as a diet scale. Lumen diameter was measured endoscopically, using the open or closed biopsy forceps as a measuring guide. Patients were then given barium capsules or tablets of increasing diameter under fluoroscopy, in the upright position. Pills were given sequentially until a pill failed to traverse the esophagus in less than 20 s. The diameter of the pill failing to traverse the esophagus within 20 s correlated strongly with the endoscopically measured diameter by Spearmans rank correlation (Rs = 0.85). The weakest correlation was between endoscopically measured diameter and the dysphagia scale (Rs = 0.48). The diameter of the pill failing to traverse the esophagus within 20 s is an excellent estimate of esophageal lumen diameter. Pill size correlates much better with esophageal lumen diameter than dysphagia or diet scales. This new dysphagia assessment system should simplify standardization of the grading of dysphagia.

Barium Sulfate

Effect of endotoxin on the rat colon glutathione level.

The effect of endotoxin on the colon glutathione level was studied in male rats. Endotoxin (Escherichia coli) from 25 ug to 100 ug/100g body weight was administered intravenously. The Glutathione level was measured 16 hours after endotoxin was given. Results showed that endotoxin significantly enhanced the colon glutathione concentration as measured by 5,5'-dithiobis (2-nitrobenzoic acid). The increase which ranged from 11% to 50% was dose dependent. At an endotoxin dose of 1000 ug/100g body weight, colon glutathione level was found to be enhanced from 2 hours up to 48 hours. In contrast, the duodenum and jejunum glutathione levels were found to be significantly reduced. The increase in the colon glutathione level may have a protective effect against oxidative damage to the colon.

Animals

Treatment of pharyngoesophageal stenosis by polyvinyl prosthesis.

Many authors have objected to the use of esophageal stents in the palliative management of lesions obstructing the cervical esophagus, especially when the prosthesis must lie within 2 cm of the cricopharyngeus muscle (CPM). Ten patients with stenosis of the cervical esophagus by lesions within 2 cm of or involving the CPM were considered for prosthesis placement. The prosthesis was successfully placed in eight patients, five of whom had a tracheoesophageal fistula (TEF). A prosthesis could not be placed in two patients, and two patients complained of a minimal but tolerable foreign body sensation. Six prostheses were custom-made. The necessity to place a prosthesis within 2 cm of or even immediately proximal to the CPM should not be considered an absolute contraindication to esophageal prosthesis placement in selected patients. Foreign body sensation may be absent or minimal, and stent migration is common.

Aged

Comparative evaluation of gastrointestinal intolerance produced by plain and tri-buffered aspirin tablets.

Two multi-investigator, double-blind, randomized, placebo-controlled, crossover trials were conducted to determine whether tri-buffered formulations of both regular strength aspirin and extra strength aspirin would be less likely than plain aspirin to provoke subjective gastrointestinal (GI) intolerance. Each trial was divided into two phases, a qualification phase and a test phase. During the qualification phase, subjects with a history of gastrointestinal intolerance to aspirin were randomized to a double-blind crossover treatment with aspirin and placebo (325 mg aspirin per tablet in study 1 and 500 mg aspirin per tablet in study 2), two tablets four times a day for 3 days or until the occurrence of stomach upset. Subjects who reported gastrointestinal symptoms with aspirin and not with placebo qualified to participate in the test phase of the study. They were rerandomized to participate in a three-way crossover study of plain aspirin, tri-buffered aspirin, and placebo in the test phase. Tri-buffered aspirin was associated with an appreciable reduction in the incidence of gastrointestinal upset relative to plain aspirin, 34 percentage points in study 1 (p less than 0.001) and 33 percentage points in study 2 (p less than 0.001). Similar results were obtained in the evaluation of the reduction of the severity of gastrointestinal symptoms.

Adult

Early diagnosis of columnar-lined esophagus: a new endoscopic diagnostic criterion.

The relationship between the proximal margins of the gastric mucosal folds and the squamocolumnar mucosal junction (SCMJ) in normal subjects and in patients with columnar-lined esophagus (CLE) was studied. Results indicate that in the normal esophagus, the SCMJ is located within 2 cm of the proximal margin of the gastric folds. The proximal margin of the gastric folds in a hiatal hernia pouch provide a fixed, reproducible, anatomic landmark at endoscopy, which designates the junction of the muscular wall of the esophagus and stomach and permits one to predict the expected normal location of the SCMJ. The diagnosis of CLE should be considered at endoscopy when either the SCMJ is located or columnar epithelium is obtained by biopsy at a site greater than 2 cm above the proximal margin of the gastric folds located within a hiatal hernia pouch. This study provides an endoscopic criterion to permit a more accurate diagnosis of CLE in its earliest stages and may permit a better assessment of its prevalence.

Barrett Esophagus

Longitudinal follow-up of chronic hemodialysis patients without vitamin supplementation.

Vitamin supplementation for dialysis patients is still controversial. In our study, we followed longitudinally over a period of a year, 15 patients on chronic hemodialysis who were deprived of vitamin supplementation. Microbiological assays were used to determine the levels of five vitamins of the B group (folate, niacin, B12, B6, and thiamine). Vitamin C was measured chemically. During the observation period when vitamins were not supplemented, a marked drop of many of these vitamins in blood levels were encountered. For vitamins B12 and C, the plasma levels remained within the normal range in all the subjects studied. For the other vitamins, the blood levels were found to be low in a few patients. Our data suggest that vitamin supplementation is probably not needed in most stable hemodialysis patients as it is recommended now, and that perhaps, if supplementation is indicated, less should be given than is presently prescribed. Further research is needed in this area.

Adult

The plasma and red cell vitamin B levels of chronic hemodialysis patients: a longitudinal study.

Plasma B12, folate, B6 and thiamine, and red blood cell folate, thiamine and niacin levels were monitored for a period of 6 months in 15 clinically stable, chronic hemodialysis patients who were not supplemented with the water-soluble vitamins. Microbiological assays were used to determine the blood levels of the water-soluble vitamins. Over the period of 6 months, none of the patients had plasma or red cell vitamin levels below the normal range. No appreciable changes were observed in the plasma and red blood cell vitamin levels before and after dialysis in 5 patients. This study showed that chronic hemodialysis patients are able to maintain normal plasma and red cell levels of some water-soluble vitamins without daily supplementation.

Adult

Medical management of esophageal obstruction and esophageal-pulmonary fistula.

In patients with advanced esophageal stenosis, the quality of life is significantly effected. Nutrition and hydration are impaired, meals cause agony not pleasure, oral secretions cannot be swallowed properly, and pulmonary aspiration is common. Restoration of an adequate lumen will relieve the symptoms of esophageal stenosis. The goal of initial therapy is to establish and maintain a patent esophagus at the lowest risk and cost to the patient. Malignant esophageal stenosis safely may be dilated by the peroral route even in patients undergoing radiotherapy or with esophagopulmonary fistula. In those patients who fail to respond to esophageal dilation, surgery, or irradiation therapy for malignant esophageal stenosis, a peroral esophageal prosthesis may be placed under local anesthesia after proper esophageal dilation. The prosthesis is prepared for each patient based on the length of the esophageal stenosis. The procedure requires less than one minute to perform. The patient has no foreign body sensation and is able to swallow a soft-to-regular diet for the remainder of his life. This method may also be used to occlude esophagopulmonary fistulae caused by malignancy. The quality and duration of life both are significantly improved by use of the peroral prosthesis in patients with malignant esophageal obstruction. Nutrition support by nasoenteric or jejunostomy tube should be used when needed to restore nitrogen balance and immune competence.

Bronchial Fistula