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Biomedical subjects

M C Champion

Publications and source records attributed to M C Champion.

32 records · Page 2Linked to original sources
PubMed1984

Is cimetidine being prescribed indiscriminately? An analytic survey of patients who present with symptoms of peptic ulcer disease.

An analytic survey was done to determine the influence of previously documented peptic ulcer disease (PUD) on the frequency of prescribing cimetidine to patients who present at a family medicine centre with symptoms of PUD. It was found that of 293 patients who presented with such symptoms over 1 year cimetidine was prescribed to 57 (19%). From the 236 patients who did not receive cimetidine 57 patients were selected at random for comparison. Information on these two groups of patients was obtained by chart review. The patients who received cimetidine were found to be significantly more likely (p less than 0.001) to have previously documented PUD than those who did not receive cimetidine. In patients in whom subsequent confirmation of PUD was not obtained, either because the results of investigations were negative or because the investigations were not ordered, cimetidine was prescribed to 63% of those who had previously documented PUD, compared with only 6% of those who did not. Of the patients who were investigated 73% of those with previously documented PUD had positive results, compared with 8% of those without previously documented PUD. The positive results were obtained by endoscopic examination in 88% of the patients with previously documented PUD, whereas upper gastrointestinal tract roentgenography was the definitive test in 73% of the patients without previously documented PUD. These findings suggest that previously documented PUD influences both the frequency of prescribing cimetidine and the investigations that are carried out.

Adult↗
PubMed1984

Cortisol and dexamethasone elimination during treatment with cimetidine.

In a randomised cross-over study of treatment for 7 days with cimetidine 600 mg twice daily and placebo, cimetidine had no effect on the pharmacokinetics of a single intravenous dose of dexamethasone sodium phosphate. Likewise the elimination characteristics of endogenous cortisol in the dexamethasone suppressed state were not affected by cimetidine.

Adult↗
PubMed1982

Comparison of platelet thromboxane synthesis in diabetic patients on conventional insulin therapy and continuous insulin infusions.

Previous work has shown enhanced aggregation and thromboxane synthesis by platelets from diabetic subjects. We have compared thromboxane synthesis by platelets from normal subjects with that of platelets from two groups of insulin-dependent diabetic patients: one group receiving conventional depot insulin therapy and the other continuous subcutaneous insulin infusions. Thromboxane synthesis was significantly higher with platelets from the conventionally-treated diabetic patients than that observed for control subjects. Patients on continuous insulin infusions were similar to control subjects. This group of patients also had better control of glycemia. The effect on thromboxane production might be related to normalization of plasma lipids which occurs with continuous infusion insulin therapy.

Arachidonic Acids↗
PubMed1982

Aortoenteric fistula. Incidence, presentation recognition, and management.

Twenty-two patients developed one or more aortoenteric fistulae following aortic reconstruction with a dacron graft. Endoscopy was performed on 11 of these patients on 17 occasions and a preoperative diagnosis was made in eight patients. Fistulous communication was most common between the aorta and duodenum (60%), and a further 30% penetrated into the jejunum and ileum. The mean period from operation to time of diagnosis was 36 months and the mean length of bleeding was 25 days, allowing ample time for preoperative evaluation. Surgery was performed on 21 of the 22 patients with an overall mortality of 77%. The best surgical results were obtained with graft resection, closure of the aorta, and maintenance of circulation by an axillofemoral graft.

Adult↗
PubMed1982

Replacement treatment with insulin in diabetes mellitus: problems and promise.

The results of epidemiological and clinical studies of diabetes in man and of studies of experimental diabetes in animals provide strong evidence: (1) that insulin-dependent diabetes mellitus is due to absolute or severe deficiency of insulin; (2) that replacement treatment with insulin is potentially capable of normalizing the metabolic abnormalities; and (3) that normalization of the metabolic abnormalities can be expected to prevent or ameliorate the complications of the disease. However, consideration of the problems involved in replacement treatment with insulin raises practical and physiological questions regarding the appropriate patterns and routes of delivery of the hormone. Studies with glucose-controlled automatic infusion systems delivering into systemic or portal vessels point to the question whether the homeostatic mechanism can be viewed as one dominated by the responses of the endocrine pancreas to glucose. Nevertheless, empirical studies with non-glucose-controlled portable programmed infusion systems delivering insulin by intravenous, subcutaneous, or intraperitoneal routes have suggested that these techniques can produce near-normoglycemia under everyday conditions in a high proportion of insulin-dependent diabetic subjects. The blood levels of biologically active insulin resulting from these treatments are not higher, and may be lower, than those with conventional depot injection therapy. It appears also that the results of intensive depot injection therapy making use of 3 or 4 injections day-1 of crystalline and intermediate-acting insulins can approximate the effects of insulin infusion treatment. It is argued that the intensive insulin treatment regimens with continuous or intermittent use of the subcutaneous route of delivery can be viewed as options in the management of insulin-dependent diabetes mellitus when adequate supervision and monitoring is available, and that clinical systems fulfilling these conditions must be provided.

Blood Glucose↗
PubMed1982

The effects of naloxone and morphine on postprandial gastrointestinal hormone secretion.

Postprandial gastrointestinal hormone secretion was not affected by the intravenous administration of naloxone. However, after the administration of morphine, multiple effects were observed. Postprandial pancreatic polypeptide, motilin, and enteroglucagon secretion were abolished and there was a reduction in the secretion of insulin, gastric inhibitory polypeptide, and neurotensin. There was prolonged secretion of gastrin. Levels of vasoactive intestinal polypeptide, somatostatin, and pancreatic glucagon were not affected. Many of these changes can be accounted for by the ability of morphine to delay gastric emptying. The prolonged secretion of gastrin could result from a combination of impaired gastric emptying and reduced postprandial gastric acid secretion. Inhibition of vagal acetylcholine release is the most likely explanation for the abolition of pancreatic polypeptide secretion. With the exception of the effects on motilin, pancreatic polypeptide, and enteroglucagon secretion this study provides no evidence that opiate substances directly affect the secretion of gastrointestinal hormones.

Adult↗
PubMedDate not supplied

National survey of radionuclide gastric emptying studies.

A survey was mailed to all institutions in Canada licensed to use radiopharmaceuticals. Questions addressed meal type; mode of preparation; and means, ranges and SD of emptying times. Seventy-eight per cent of 222 facilities responded, including all 55 teaching centres. Eighty-five per cent of teaching and 56% of nonteaching centres perform solid phase gastric emptying studies (GES). The majority use 99mTc sulphur colloid (Tc-SC) added to eggs before cooking as the standard meal. Twenty-five per cent of teaching and 21% of nonteaching centres perform liquid phase GES. Most use a watery solution of 111Indiethylenetriamine pentaacetic acid. Gastric emptying for solid phase GES, expressed as time for 50% emptying (mean t1/2), varied from 42 to 105 mins for centres using the Tc-SC egg meal. Twenty-eight per cent of teaching centres used +/- 2 SD to define their normal range, 26% used +/- 1 SD, 6% used +/- 1.5 SD, and 40% did not know the number of SD used. Twenty per cent of nonteaching centres used +/- 2 SD, 12% used +/- 1 SD and 68% did not know how many SD were used. For liquid phase GES, mean t1/2 varied from 20 to 60 mins. Eighteen per cent of centres used healthy volunteers to establish or validate normal ranges. There is substantial variability among the normal ranges for radionuclide solid and liquid phase GES in both teaching and nonteaching centres across Canada. A minority of facilities have established or validated their own normal ranges in healthy volunteers. There is a need for a more standardized protocol and range of normal, with internal validation by each institution.

Canada↗