Effects of diet-induced ketosis in rats with hypoglycaemia due to a serially transplantable insulinoma

In view of the ability of ketones to partially replace glucose as an alternative fuel in the brain, the potential protective effects of diet-induced ketosis were examined in male NEDH rats with hypoglycaemia due to a serially transplantable radiation-induced insulinoma. Ketosis was induced by daily oral administration of medium chain triglycerides to normal rats and to insulinoma-bearing rats 1 day after subcutaneous subscapular implantation of tumours fragments. All rats treated with medium chain triglycerides became ketotic within 72 hours, and plasma 3-hydroxybutyrate concentrations remained 5-10 fold elevated at 24 days. Untreated insulinoma-bearing rats became moderately hyperinsuliaemic and hypoglycaemic by 17 days, with the later manifestation of more marked hyperinsulineamia (21.6 +/- 0.8 ng/ml, mean +/- SEM) severe hypoglycaemia (1.5 +/- 0.1 mmol/l) and death by 24-28 (26 +/- 1) days. Induction and maintenance of hyperketonaemia did not affect the development of hyperinsulineamia, hypoglycaemia or the exaggerated fall of plasma glucose produced by an 8 hour fast in these rats. However by day 21, the severity of hypoglycaemia was greater in insulinoma-bearing rats receiving medium chain triglycerides, culminating in accelerated death by 22-25 (23 +/- 1) days and an accompanying 50% decrease in final tumour weight. These results demonstrate that induction of ketosis in the face of marked hyperinsulinaemia did not afford protection against the profound hypoglycaemia produced by a serially transplantable rat insulinoma.     

Correlations between the functional activity and proliferation of the thyroid parenchyma. The proliferative forms of the parenchyma of the thyroid

Multiple thyroid adenomas formed by straight or coiled epithelial cords developed in experiments on adult male rats as a result of prolonged intermittent 6-MTU administration. Such epithelial cords could be sometimes observed in thyroid parenchyma regeneration after partial thyroidectomy. These cords originated from thyrocytes of the follicle epithelium. In the proliferating thyroid parenchyma DNA replication mainly terminated in endomitoses (previously reported data) which in thyrocytes of prismatic form resulted in their separation from proximal and distal daughter cells. Proximal daughter cells kept contact with the follicle lumen but distal ones lost it, hence their iodine uptake and origination weakened. Therefore, the biosynthesis of thyroglobulin decreased in cytoplasm of distal daughter cells but the formation of thyroalbumin increased. In consequence the distal daughter cells with this shift in protein biosynthesis underwent hypertrophy and further originated the proliferation of extra follicular epithelial cords. The formation of new follicles mainly took place with the differentiation of interfollicular islets separated from proliferating extrafollicular epithelial cords. Thyrotropin, the principal stimulator of hormonopoietic thyrocyte activity, did not necessarily influence the activation of thyroid parenchyma proliferative processes.     

Organ-sparing operations in pyloroduodenal stenosis caused by peptic ulcer

An experience with the treatment of 106 patients with pyloroduodenal stenosis of ulcerous etiology by vagotomy with draining operations has shown high efficiency of these measures resulting in lower rate of postoperative lethality. Selective proximal and stem vagotomy does not aggravate gastric atony in patients with stenosis. Electro-stimulation was found to be an effective method of treatment of this complication in the postoperative period of patients with gastric atony.     

Serum and peritoneal dialysate thyroid hormone levels in patients on continuous ambulatory peritoneal dialysis

Thyroid function tests were performed on 16 clinically euthyroid patients with end-stage renal failure undergoing regular haemodialysis or continuous ambulatory peritoneal dialysis and compared with 8 healthy subjects. The patient groups were carefully matched, especially regarding relative duration of dialysis (mean of 24 months). Total serum thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine and reverse triiodothyronine were significantly lower in both patient groups than control. The thyrothrophin response to the standard thyrotrophin-releasing hormone test was delayed and blunted. Using a novel concentration technique we measured loss of T4 in peritoneal dialysate effluent and found it to be approximately 10% of daily thyroidal T4 release.     

Rapid screening of organosulfur agents for potential chemopreventive activity using the murine NA assay

The chemopreventive efficacy of 11 organosulfur compounds was assessed using the murine nuclear aberration (NA) assay in C57BL/6J mice. The sulfur compounds were introduced by stomach gavage. Benzo[a]pyrene (BP), which is a carcinogen known to a) undergo biotransformation by pathways mediated by P-450 and b) induce NA in the intestine, was used as the challenge. All animals were killed 48 hours after BP injection, and NA per crypt were scored. The results indicated that several agents were active in inhibiting BP nucleotoxicity to the colon, most notably, allyl mercaptan, benzyl mercaptan, and phenylethyl mercaptan. The NA assay was useful in effectively prescreening certain compounds for potential interactions with chemical carcinogens, thus serving as one indicator of chemopreventive activity.