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Biomedical subjects

J C Thompson

Publications and source records attributed to J C Thompson.

At least 415 records · Page 23Linked to original sources
PubMed1980

Radioimmunoassay of plasma cholecystokinin (CCK), duodenal release of CCK, diurnal variation of plasma CCK, and immunoreactive plasma CCK components in man.

A precise and specific radioimmunoassay method for measuring plasma cholecystokinin (CCK) is described. The present assay system using a stable tracer iodinated by means of a modified Chloramine-T method followed by purification on a Sephadex G-15 and a SP Sephadex C-25 column, as well as careful corrections for non-specific plasma effects, allows measurements of fasting plasma CCK in the low pmol/l range; the significant rise in plasma CCK following duodenal infusion of fat; and the significant diurnal variation of plasma CCK. Apparent immunoreactive meal-stimulated plasma CCK was eluted from a Sephadex G-50 superfine column in four fractions. The first and largest peak probably represents plasma CCK bound to plasma proteins and non-specific plasma effects, the second and smaller peak big CCK with molecular weight between some 5,000 and some 30,000, the shoulders following the second peak ordinary CCK33 and CCK39 variant, and the final, and by far the smallest peak, may possibly represent COOH-terminal tetra- (CCK4) or octapeptides (CCK8) of CCK.

Animals↗
PubMed1980

Hormonal (gastrin, secretin, cholecystokinin) and secretory effects of bombesin and duodenal acidification in dogs.

We have studied the influences of duodenal acidification on the effects of bombesin on gastric and pancreatic secretion and on blood levels of gastrin, secretin, and cholecystokinin (CCK) in six conscious dogs with chronic gastric and pancreatic fistulas. Duodenal acidification suppressed bombesin-stimulated gastric acid output (from 20.1 +/- 4.2 to 8.2 +/- 1.9 mEq/120 min) and gastrin release (from an integrated 2-hour output of 16.0 +/- 1.2 to 11.1 +/- 1.1 ng-min/ml). On the other hand, duodenal acidification augmented bombesin-stimulated secretion of pancreatic bicarbonate (from 0.75 +/- 0.12 to 7.81 +/- 2.0 mEq/120 min) and protein (from 0.57 +/- 0.10 to 1.00 +/- 0.18 gm/120 min). Blood levels of CCK (but not of secretin) were increased with bombesin alone, whereas blood levels of secretin (but not CCK) were increased by duodenal acidification alone. Bombesin plus duodenal acidification resulted in increase of both CCK and secretin. This increase of secretin may be responsible, in part, for suppression of both gastric acid output and gastrin release, as well as for increases in pancreatic secretion of bicarbonate and protein.

Animals↗
PubMed1980

Release of pancreatic polypeptide in humans by infusion of cholecystokinin.

Plasma levels of pancreatic polypeptide were measured after a test meal and after infusion of graded doses of 99% pure cholecystokinin in 6 healthy volunteers. Initial attempts at sterilization of 99% pure cholecystokinin resulted in complete inactivation. Successful sterilization was accomplished by filtration by using specially treated silver-coated filters. Biologic activity of sterilized material was confirmed with cholecystokinin bioassay, and plasma levels of sterilized cholecystokinin achieved by exogenous infusions were measured with a specific cholecystokinin radioimmunoassay. Significant increases in plasma levels of pancreatic polypeptide were found with a test meal and with infusions of 0.25 and 0.5 micrograms/kg-hr of 99% pure cholecystokinin. Integrated values of pancreatic polypeptide released by the low-dose and the high-dose infusions of 99% pure cholecystokinin were 59% and 50% of that obtained by food, respectively. Integrated levels of cholecystokinin after 45 min of infusion of 0.25 micrograms/kg-hr were equal to those after a standard meal. Cholecystokinin, therefore, is an effective humoral releaser of pancreatic polypeptide in humans and may play an important role in the intestinal phase of release of pancreatic polypeptide.

Adult↗
PubMed1980

Predicting adaptive functioning of mentally retarded persons in community settings.

The impact of a variety of individual, residential, and community variables on adaptive functioning of retarded persons was examined using a multiple-regression analysis. Individual characteristics (especially IQ) accounted for 21 percent of the variance, while environmental variables, primarily those related to normalization, accounted for 35 percent. The data suggest that environmental normalization may be an effective technology for the promotion of independent functioning of retarded people as well as an ideology.

Adolescent↗
PubMed1979

Separate pancreatic gastrin cell and beta-cell adenomas: report of a patient with multiple endocrine adenomatosis type 1.

A patient initially showed symptoms of peptic ulcer disease in 1953 and was later found to have hypercalcemia and hyperparathyroidism. Peptic ulcer symptoms persisted after parathyroidectomy, and results of studies provided evidence of the Zollinger-Ellison syndrome. Evaluation of the patient's family showed a classic pattern of multiple endocrine adenomatosis type 1. The patient underwent total gastrectomy and excision of a gastrin cell adenoma in 1971 with relief of symptoms, but with persistent hypergastrinemia. He remained in good health until January 1976, when symptoms of hypoglycemia developed. Results of laboratory studies were compatible with the diagnosis of a pancreatic beta-cell adenoma. At the time of operation, an adenoma of the head of the pancreas was found. The tumor was excised; no other metastatic tumors were found. The tumor was compatible with a beta-cell adenoma and was found to contain high concentrations of insulin; there was no important amount of gastrin. Symptoms of hypoglycemia have entirely disappeared.

Adenoma↗
PubMed1979

Effect of parenteral L-amino acids on gastric secretion and serum gastrin in normal dogs and dogs with portacaval transposition.

The effect of intravenous infusion of L-amino acids (FreAmine II) on gastric secretion and on circulating levels of gastrin was studied in five gastric fistula dogs and three dogs with portacaval transposition. Significant increases in gastric acid secretion were found after infusions which delivered 2.0, 4.0, and 8.0 gm/hr of L-amino acids in five gastric fistula dogs. After portacaval transposition, administration of amino acid solutions via the hindleg (through the liver) resulted in a great fall in the acid secretory response. Gastrin levels were significantly elevated after 8.0 gm/hr of amino acids. After 2.0 and 4.0 gm/hr, there was a slight but insignificant increase in serum gastrin levels. Gastrin levels were unchanged after infusion of 8.0 gm/hr of L-amino acids through the liver. We conclude that L-amino acids given intravenously stimulate gastric acid secretion in a dose-dependent manner by a mechanism which does not involve gastrin. At the highest dosage of amino acids, some gastrin was released which might have stimulated acid output further.

Amino Acids↗
PubMed1979

[Effect of hypophysectomy on gastrin release and antral gastrin concentration].

Hypophysectomy resulted in a lower amount of basal serum gastrin. In hypophysectomized rats, there was a release of serum gastrin after food intake; however, the serum gastrin level was lower 30 min postprandially. The most important effect of hypophysectomy is absence of repletion of antral gastrin after an initial postcibarial depletion. We conclude that the immediate synthesis of antral gastrin after food intake is inhibited by hypophysectomy.

Animals↗
PubMed1979

Effect of vagal stimulation on pancreatic secretion and on blood levels of gastrin, cholecystokinin, secretin, vasoactive intestinal peptide, and somatostatin.

We investigated in dogs the effect of graded frequencies of electrical vagal stimulation (1.5, 3, 6, and 12 cps) on pancreatic exocrine secretion and on portal blood levels of gastrin, secretin, cholecystokinin (CCK), vasoactive intestinal peptide (VIP), and somatostatin (STS). Stimuli of all four frequencies, each with a duration of 5 minutes, were applied with a secretin background of 0.25 CU/kg-hr, and one stimulatory period of 12 cps was applied without a secretin background. With secretin, a significant, frequency-dependent increase of volume and of pancreatic protein secretion occurred from 3 to 12 cps. Gastrin values increased significantly at all frequencies. VIP and STS increased significantly with 3, 6, and 12 cps. Maximal responses for gastrin, VIP, and STS were observed with 6 cps. Peak values for gastrin and VIP were found during stimulation, whereas STS peaked after the end of the stimulatory period. The integrated responses of gastrin and STS showed significant correlation (P less than 0.01). The results suggest that vagally induced pancreatic response is only partially mediated by gastrin and perhaps VIP, and that endogenous gastrin may be one of the releasing factors for somatostatin. Plasma levels of CCK and secretin did not change after electrical stimulation, which provides direct evidence that their release is unlikely to be under vagal control, and that CCK does not mediate the protein secretion obtained after electrical stimulation of the vagus.

Animals↗
PubMed1979

Veterinary medicine in New York State: overview of distribution patterns.

An understanding of the distributional patterns of Veterinary practitioners in New York State can assist in optimizing veterinary services and opportunities. Veterinarians have been arrayed by type of practice and location within counties and major land form regions. Relationships between the number of practitioners and human and animal populations have been examined in these areas and show the inadequacy of basing veterinary needs on human population data. In contrast, large animal numbers show a much closer correspondence to veterinary practitioners, with ranges of 3341 to 6561 animals being serviced per veterinarian in the large and mixed service fields (98% of these totals are food animals). Data on age composition and degree institution (in-state versus out-of-state) provide indications of the length of service, turnover rate and retention rate for practitioners trained in New York State. At present 60 percent of New York State practitioners received their education at Cornell and more than three quarters of the active total completed their education since 1950.

Age Factors↗
PubMed1979

An outbreak of suspected solanine poisoning in schoolboys: Examinations of criteria of solanine poisoning.

Seventy eight schoolboys became ill after eating potato at lunch on the second day of the autumn term. Seventeen of the boys required admission to hospital. The gastrointestinal, circulatory, neurological and dermatological findings and the results of laboratory investigations were in keeping with solanine poisoning. The illness affected the junior boys and all the monitors but no other senior boys or staff. This pattern was compatible with the consumption of a relatively small number of toxic potatoes believed to have come from a bag (A) left in the stores since the summer term. The amount of solanine in potato waste recovered after the meal was excessive as assessed by its anticholinesterase activity. The amount of alpha-solanine and alpha-chaconine in the flesh and peel of potatoes from a bag (B) known to have been left from the previous term was high. The anomalously narrow margin between the solanidine alkaloid content reported for normal and toxic potatoes might perhaps result from an excessive synthesis by the latter of additional, related steroids, such as sapogenins and saponins, which, by promoting gastrointestinal absorption or other means, might enhance the toxicity of solanidine alkaloid.

Adolescent↗