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Biomedical subjects

D M Grace

Publications and source records attributed to D M Grace.

At least 37 records · Page 2Linked to original sources
PubMed1987

Pancreatic endocrine responses to nutrients and bombesin after segmental pancreas autotransplantation in dogs.

The capacity of autotransplanted (ATP) distal pancreas segments with systemic venous and peritoneal exocrine drainage to support physiologic control of plasma glucose levels was tested, and compared with the functions of "simulated autotransplants" (SATP) prepared with similar dissection and peritoneal exocrine drainage, but with hepatic portal venous drainage, in dogs. In ATP in the postabsorptive state, plasma levels of glucose, immunoreactive insulin (IRI) and immunoreactive glucagon (IRG1) were normal. Autotransplants resulted in impaired glucose tolerance after meals with impaired early insulin responses, and the normal brisk rise of IRG1 in the plasma was delayed and reduced through the first 30 min of feeding. In ATP, also, the response to bombesin was abnormal; the normal stimulation of release of both IRI and IRG1 was delayed in both cases. In studies of responses to oral and intravenous glucose in ATP and SATP dogs, similar mild degrees of glucose intolerance were found with both routes of administration; however, whereas in ATP dogs increases of IRI were highly exaggerated with both routes of administration of glucose, in SATP dogs plasma IRI rose from subnormal levels in the postabsorptive state through subnormal increments with both routes of administration. Further studies are necessary to determine the relative importance of denervation and reduction of the mass of the pancreas in these effects, and to assess the significance of the differences in blood insulin levels in the two preparations.

Administration, Oral↗
PubMed1987

Patient selection for obesity surgery.

Patients selected for gastroplasty should be at least 45 kg above ideal weight, between the ages of 18 and 50, and operated on in a center with good results, where team assessment and long-term follow-up is emphasized. Referral by a family doctor who provides local care and support is important. Medical complications need not be present because the idea is to prevent them, but problems such as sleep apnea, adult onset diabetes mellitus, hypertension, osteoarthritis, and infertility, which may be corrected by weight loss, increase the indication for gastroplasty. Patients should have social support and be intelligent enough to understand the postoperative diet and the need for regular follow-up. Those with a history of psychiatric admission require careful preoperative assessment by psychiatrist or psychologist and close follow-up and support. Patients should have made a good supervised attempt at dieting, have had stable weight for 3 to 5 years preoperatively, and have stopped smoking at least 6 weeks prior to operation. Tests to assess personality factors, eating habits, and motivation are developing, but more precise methods of selecting patients for gastroplasty and predicting successful and uncomplicated weight loss are still needed.

Age Factors↗
PubMed1987

Smoking habits of the morbidly obese prior to gastroplasty.

Smokers weigh less on average than nonsmokers, but there is little data on the smoking habits of the severely obese. Cigarette smoking increases the risk of cardiovascular disease and may add to the existing risk among obese individuals. The purpose of this article is to report on smoking habits of a group of morbidly obese individuals being considered for surgery, to compare these smoking levels to those in the general population, and to assess the relationship between smoking and hypertension in this group. In Canada as in other countries, smoking prevalence has decreased in recent years, but it remains a major health problem.

Adolescent↗
PubMed1987

Recognition and management of Marlex erosion after horizontal gastroplasty for morbid obesity.

Between 1979 and 1982, 162 patients underwent horizontal gastroplasty in which polypropylene mesh (Marlex) was used to support the greater curve channel. There were no deaths and early weight loss was good. The operation was stopped because of late weight gain. Marlex erosion was recognized by endoscopy in 10 (6%) patients between 27 and 60 months after operation. Two other patients with Marlex erosion had the gastroplasty performed elsewhere. The patients' symptoms were abdominal pain, vomiting or weight gain. The Marlex was often difficult to resect because the inflammatory mass was adherent to spleen or pancreas. Reconstruction by Roux-en-Y gastric bypass or vertical banded gastroplasty allowed continued weight loss and gastrogastrostomy, although technically easier, resulted in weight gain. The author concludes that long-term follow-up is necessary after any gastroplasty or gastric bypass procedure especially when foreign material is used to support the stoma.

Adult↗
PubMed1987

Psychosocial risk factors in gastric surgery for obesity: identifying guidelines for screening.

This study aimed to isolate psychological predictors of outcome from horizontal reinforced gastric surgery for morbid obesity. Fifty-seven patients were assessed pre-operatively and 1 year after surgery. Prior inpatient psychiatric history (but not outpatient history), MMPI scale elevations, negative life events, and low social support (predictors) related significantly to medical complications and satisfaction with results of surgery, but not weight loss (outcome). Prior inpatient psychiatric history and low social support also predicted psychological complications postoperatively. Demographic factors failed to predict any aspects of outcome. Multiple regression analyses of the four significant predictors explained 43 percent of the variance in medical complications, 42 percent in satisfaction, and 31 percent in psychological complications. Inpatient psychiatric history was the strongest single predictor in all cases.

Adult↗
PubMed1987

Smoking status among a group of morbidly obese men and women referred for gastroplasty.

The smoking habits of all morbidly obese patients referred for possible gastroplasty (between January 1, 1983 and December 31, 1985) were assessed. There were 240 patients, 198 women 83 percent) and 42 men (17 percent). Mean age for women was 38 +/- 9 years and weight 121 +/- 17 kg. Men were 36 +/- 9 years old and weighed 154 +/- 24 kg. Forty percent of each group smoked cigarettes daily and 10 percent of women and 12 percent of men were ex-smokers. Twenty percent of the females and 47 percent of the males were heavy smokers (greater than 25 cigarettes per day). Female ex-smokers were much more apt to be on treatment for hypertension than non-smokers (55 vs 10 percent, P less than 0.001). These morbidly obese patients in Southern Ontario smoked more heavily and in higher proportion than reported for adults in Ontario or Canada. Low socioeconomic status may partially explain these results. Better methods of controlling smoking and eating are needed for the morbidly obese.

Adult↗
PubMed1987

Meralgia paresthetica after gastroplasty for morbid obesity.

In three morbidly obese patients (mean weight 169 kg), severe hip pain developed immediately after gastroplasty. The differential diagnosis included thrombophlebitis, osteoarthritis and lumbar disc protrusion. The pattern of pain and associated numbness was characteristic of compression of the lateral cutaneous nerve of the thigh, a condition known as meralgia paresthetica. The likely cause was compression of the thigh by the metal post of the Gomez retractor. Only the most obese patients suffered this syndrome and all symptoms resolved spontaneously within 3 months.

Adult↗
PubMed1986

The effects of cimetidine and ranitidine with and without metoclopramide on gastric volume and pH in morbidly obese patients.

The efficacy of preanaesthetic intravenous cimetidine versus ranitidine with and without metoclopramide for acid aspiration prophylaxis was assessed in 60 morbidly obese patients in a double-blind manner. Group 1 patients received cimetidine 300 mg + saline. Group 2 patients received cimetidine 300 mg + metoclopramide 10 mg. Group 3 patients received ranitidine 100 mg + saline. Group 4 patients received ranitidine 100 mg + metoclopramide 10 mg. Gastric fluid was aspirated for analysis of volume and pH following induction of anaesthesia. All four premedication regimens were equally effective in reducing the gastric volume and acidity and the inclusion of metoclopramide had no additive effect. Although statistically not significant, two patients in the cimetidine groups remained at risk (volume greater than 25 ml and pH less than 2.5) while no patients in the ranitidine groups remained so.

Adult↗
PubMed1986

Gastric emptying before and after transverse gastroplasty for morbid obesity.

Twenty-three morbidly obese patients underwent gastric emptying studies (Tc-99m egg salad sandwich--a semisolid meal) preoperatively, and at three months and 12 months postoperatively to evaluate the effect of transverse gastroplasty on gastric emptying and to determine the predictive value of this study for weight loss. At three months pouch emptying was variable with nine of 23 patients having prolonged half-times, and 14 shortened half-times compared with preoperative values, despite both groups having identical weight loss. At 12 months pouch half-times returned to baseline. The data suggests that this type of gastroplasty causes weight loss solely by reducing the gastric volume resulting in reduced meal volume. Weight loss is not related to impaired pouch emptying, which might result in a prolonged feeling of fullness. Gastric emptying studies neither preoperatively nor postoperatively have weight loss predictive value for this particular operation.

Adult↗
PubMed1986

Immune response after gastric bypass and weight loss.

The immune response of 22 morbidly obese patients was measured before and 6 months after gastric bypass. In-vivo skin testing was carried out using five recall antigens. In-vitro response assessed the ability of isolated lymphocytes to take up radioactive thymidine after culture with the same antigens. The mean (+/- SD) preoperative weight of the patients of 122 +/- 14 kg declined by 33.5 +/- 8 kg after 6 months. The number of positive skin tests increased from a mean (+/- SEM) of 1.8 +/- 0.17 to 2.1 +/- 0.17 (p = 0.2). Mean (+/- SEM) induration of the skin-test response assessed at 24 hours after antigen injection increased from 4.7 +/- 0.6 mm to 5.5 +/- 0.6 mm (p = 0.35) and at 48 hours from 5.4 +/- 0.7 mm to 6.9 +/- 0.9 mm (p = 0.05). One patient who was anergic before gastroplasty responded normally 6 months later after substantial weight loss. In-vitro response, expressed as a stimulation index (+/- SEM), increased from 4.71 +/- 0.65 to 7.95 +/- 1.56 (p = 0.06) for the average of all antigens and from 12.85 +/- 2.05 to 15.79 +/- 2.84 (p = 0.2) for the largest response. The authors conclude that the response to test antigens in vitro and in vivo is not reduced significantly 6 months after gastric bypass and profound weight loss. Patients with severe vomiting, rapid weight loss or sepsis may respond differently and require individual assessment.

Adult↗
PubMed1985

Postoperative abdominal wall hematomas have a distinctive appearance on ultrasonography.

In six patients a large abdominal wall hematoma developed 1 1/2 to 6 months after operation. In each case differentiation of incisional hernia from hematoma was difficult, but the distinctive appearance on ultrasonography of an ovoid mass with thick straight internal septae, characteristic of hematoma, was noted in all. Ultrasonography also showed the multilocular nature of the lesion which made percutaneous aspiration difficult.

Abdominal Muscles↗
PubMed1984

Intestinal stomal dilatation.

Dilatation of 23 surgically created gastrointestinal tract stomata in 21 patients has been performed using angioplasty techniques. A success rate of 44% was achieved in nine patients with gastric stapling and Marlex mesh wrapping of the greater curve stoma. In 13 patients with gastric stapling, and either sutured gastro-gastrostomy or roux-en-y gastro-jejunal bypass, a success rate of 77% was achieved. In one patient with a jejunostomy, stenosis dilatation was also successful.

Angioplasty, Balloon↗
PubMed1984

The economy of the enterohepatic circulation of bile acids in the baboon. 1. Studies of controlled enterohepatic circulation of bile acids.

A primate model with controlled enterohepatic circulation has been developed which allowed short-term evaluation of bile salt pool size, cycling frequency, and fecal losses. We found that when bile salt secretion into the small bowel was increased above 700 mumol/hr bile acid pool cycling frequency was also increased. The latter allowed short-term regulation of bile salt pool size by affecting increased fecal losses. These compensatory mechanisms were associated with a return of bile acid secretion and cycling frequency to normal usually within 12-24 hours. Conversely, during decreased bile salt secretion, regulation of bile salt pool size was accomplished by decreased pool cycling, which decreased fecal losses. Bile acid secretion into the intestine was therefore a major determinant of bile salt cycling frequency. The latter affected bile salt fecal loss to provide short-term regulation of bile salt pool when feedback regulation of bile salt synthesis was nonoperative.

Animals↗
PubMed1983

Effects of dietary substitution of mixed amino acids for glucose on the splanchnic metabolism of plasma triglycerides, cholesterol, carbohydrates, and amino acids in conscious fed baboons.

Splanchnic metabolism was studied in the fed state during prolonged constant intravenous administration of tracer amounts of [9,10]-3H palmitic acid and the calculated isocaloric intraduodenal administration (13 mg/min X kg body wt0.75) of either (1) glucose, (2) 15% mixed amino acids and 85% glucose or (3) 45% mixed amino acids and 55% glucose to conscious, restrained female baboons that had been maintained on a similar diet (supplemented in essential nutrients) for the previous 9 days. Secretion of plasma triglycerides from the splanchnic region was quantified from splanchnic flow and radiochemical measurements of transsplanchnic gradients of 3H-labeled free fatty acids and triglycerides. Mean splanchnic secretion of plasma triglycerides increased significantly as the proportion of dietary calories derived from amino acids was varied from 0 to 15 to 45% (mean values 1.1 +/- 0.1, 2.6 +/- 0.2 and 4.2 +/- 0.3 mumol/min kg body wt0.75, respectively, p less than 0.05). Increased triglyceride secretion was attributable to both significantly higher rates of esterification of free fatty acids taken up in the splanchnic region to triglycerides released into hepatic venous blood plasma (mean values 10 +/- 1, 16 +/- 2 and 34 +/- 5%, respectively) and to significantly higher rates of secretion of triglycerides derived from precursors other than free fatty acids. Higher intake of amino acids was also associated with both higher plasma concentrations of cholesterol and higher values for hepatic oxidation of cholesterol to bile acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1982

Immune response to transplanted pancreas in pigs.

Segmental allografts of the body and tail of the pancreas have been carried out in pigs using an open duct technique. Diabetes was induced by total pancreatectomy. Control animals on no immunosuppression survived an average of 17 days while animals receiving CyA survived 30 days. In the CyA group those with adequate serum levels of CyA survived 46 days while those with low levels survived 18 days. Once the animal became diabetic rejection was not reversible. In this model complement dependent cytotoxicity was more useful than lymphocyte mediated cytotoxicity in predicting rejection. However the rejected pancreas showed intensive mononuclear infiltration. Malabsorption resulting from total pancreatectomy used to induce diabetes may have contributed to the erratic CyA absorption. Prolonged and relatively normal pancreatic allograft function is possible, but adequate CyA levels must be achieved and maintained. Monitoring of serum levels is essential.

Animals↗