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N T McPhedran

Publications and source records attributed to N T McPhedran.

15 recordsLinked to original sources
PubMed1993

Canadian medical schools before ACMC.

The earliest medical schools were established to supplement apprenticeship, the only route to practice available in colonial Canada. By 1885, eight medical schools were trying to accommodate the volume of new scientific information flowing from Europe. In 1910, when Flexner evaluated the schools against the Johns Hopkins model, some were woefully deficient, but by 1928 all had achieved Class A rating. The 1921 discovery of insulin in Toronto gave impetus to scientific research and, possibly, influenced the formation and funding of the National Research Council in 1934. Clinical specialization expanded, leading in 1929 to the establishment of the Royal College of Physicians and Surgeons of Canada to accredit training and certify graduates. The Association of Canadian Medical Colleges was formed at a meeting of deans to discuss a federal offer of funding and to accelerate the graduation of physicians for the war effort.

Canada↗
PubMed1986

Intermediary metabolism in diabetic dogs treated with pancreatic autotransplants and insulin pumps.

Diurnal metabolite profiles were studied in pancreatectomized dogs who had received grafts of their own pancreas. The results were compared to similarly diabetic animals who received exogenous insulin pumped intravenously either peripherally or portally. All animals were studied at least 52 weeks after pancreatectomy. Nondiabetic animals were similarly studied as normal controls. Interestingly, all of the diabetic animals were in excellent metabolic control but significant differences from normal in one or more of the metabolic variables existed in each group. Thus, none of the methods of insulin replacement entirely restored to normal the metabolic state of the pancreatectomized dogs. For example, in the autotransplanted animals, the profiles of glucose, lactate, pyruvate, and alanine manifested either abnormal levels and/or abnormal postprandial excursions. The grafts delivered insulin into the peripheral rather than portal circulations. In the peripherally infused animals, the profiles of pyruvate, alanine, and free fatty acids were also somewhat abnormal. In the portally infused animals the profiles only of pyruvate and alanine showed minor abnormalities without clear statistical significance in some respects as well. The other differences observed were statistically significant (P less than 0.05-0.01). These results suggest that the portal route of insulin delivery may be the route of choice if intermediary metabolism is to approximate normal most closely whether exogenous intravenous insulin is replaced by implanted pumps or endogenous insulin is replaced by pancreatic transplants and that none of these futuristic methods of insulin replacement entirely restore to normal the metabolic state of pancreatectomized dogs.

3-Hydroxybutyric Acid↗
PubMed1986

Metabolic control in diabetic dogs treated with pancreatic autotransplants and insulin pumps.

Fasting metabolite and hormonal levels were studied prospectively in pancreatectomized dogs who had received grafts of their own pancreas. The results were compared with similarly diabetic animals who received exogenous insulin pumped intravenously either peripherally or portally. All animals were studied for 48-91 wk after pancreatectomy. In the autotransplanted animals, the fasting levels of glucose, lactate, pyruvate, alanine, pancreatic glucagon, insulin, gastric inhibitory peptide, and pancreatic polypeptide were all abnormal. In the peripherally infused animals, the fasting levels of glucose, pyruvate, alanine, free fatty acids, and insulin were also abnormal. In the portally infused animals, pyruvate, alanine, gastric inhibitory peptide, gastrin, and pancreatic polypeptide were abnormal. These results suggest that the portal route of insulin delivery may be necessary if fasting metabolite and hormonal levels are to approximate normal most closely whether exogenous intravenous insulin is replaced by implanted pumps or endogenous insulin is replaced by pancreatic transplants.

Animals↗
PubMed1985

Glycemic control in diabetic dogs treated with pancreatic autotransplants and insulin pumps.

The restoration of metabolic control in diabetes mellitus is predicated upon the uniform achievement of fasting euglycemia. In the absence of fasting normoglycemia, metabolic control is fundamentally compromised. We asked whether the currently experimental methods of treating experimental diabetes are capable of achieving normality in this regard. We therefore examined fasting plasma glycemia prospectively in a group of normal animals. This important index of metabolic homeostasis was remarkably tightly controlled with a mean +/- SD of 94 +/- 5 mg/dl. As a model of diabetes, we pancreatectomized a similar but larger group of animals. Some received grafts of their own pancreas while some received exogenous insulin by continuous intravenous infusion using an external pump. Half of this infused group received the insulin portally while the other half received it peripherally. Although our findings were globally similar to what has been reported previously, we elucidated subtle differences which heretofore have not been considered. Fist of all, the mean +/- SD fasting plasma glucose (FPG) concentration in the group of transplanted animals was 103 +/- 16 mg/dl, significantly higher than normal (p less than 0.001). It was, however, similar to the supra-normal levels we observed in the peripherally infused animals (100 +/- 25 mg/dl). Only the portally infused dogs had FPG levels of 95 +/- 27 mg/dl entirely similar to the normal controls. Most remarkably, all treatment methods resulted in variations in FPG levels which were significantly greater than normal (p less than 0.001), with coefficients of variation 3-5 times normal. Whether in the autotransplanted animals this variability represented the peripheral route of endogenous insulin replacement or the aneural nature of the transplanted gland was not clarified.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Pancreatic autotransplantation.

Segmental pancreatic autotransplantation is successful in our hands if blood flow through the splenic artery is enhanced by either a jump graft or a distal fistula, and if these technical manoeuvres are supplemented by anticoagulation. We found the jump method of arterial anastomosis was the most successful. Perfusion of the isolated graft is not necessary, and may even be harmful. Ischemia up to 3 hours appears to be well tolerated. The intraperitoneal location of the graft does not affect outcome, but preservation of the left gastric artery reduces mortality secondary to stomach and omentum ischaemia. Animals must be supplemented with Viokase 10 tablets daily. If the remaining pancreas has been removed graft function is best assessed by monitoring blood sugars. No animal recovers which becomes diabetic under these conditions. Serum insulin, serum glucagon and glucose tolerance tests (with or without calculation of K values) are no more useful than blood glucose to recognize graft loss.

Animals↗