Search PubMed⌕ Search

Biomedical subjects

S A Ross

Publications and source records attributed to S A Ross.

At least 127 records · Page 7Linked to original sources
PubMed1981

The importance of triglyceride hydrolysis for the release of gastric inhibitory polypeptide.

Gastric inhibitory polypeptide is released from the small intestine after the ingestion of fat, but it is not known if triglyceride itself or one of its hydrolytic products is the stimulus to gastric inhibitory polypeptide secretion. Children with cystic fibrosis and defective fat lipolysis were studied to help define the exact stimulus to gastric inhibitory polypeptide secretion. Pancreatic enzyme therapy was withheld from the children with cystic fibrosis during these tests. Ten normal children and 10 children with cystic fibrosis each ingested corn oil and serum immunoreactive gastric inhibitory polypeptide measured. The normal children had a 10-fold increase in serum gastric inhibitory polypeptide levels after the triglyceride, but no increase in immunoreactive gastric inhibitory polypeptide occurred in the children with cystic fibrosis. When three of the children with cystic fibrosis received their pancreatic enzymes and then ingested the triglyceride, gastric inhibitory polypeptide values increased 10-fold. To assess the relative importance of the products of triglyceride hydrolysis and the chain length of the component fatty acids, 6 normal adults consumed, on separate days, 40 mmol of corn oil, medium-chain triglycerides, long-chain fatty acids, or glycerol. Long-chain fatty acids caused a fourfold increase and triglyceride a 12-fold increase in gastric inhibitory polypeptide levels. There was no increase after medium-chain triglyceride or glycerol. This indicates that long-chain fatty acids-the end product of triglyceride hydrolysis-are a stimulus to gastric inhibitory polypeptide secretion; that this release is apparently proportional to the quanitity of long-chain fatty acid present; and that hydrolysis of triglyceride is required before gastric inhibitory polypeptide release can normally occur after fat ingestion.

Adolescent↗
PubMed1978

Glucose tolerance during anaesthesia and surgery. Comparison of general and extradural anaesthesia.

The effects of general and extradural anaesthesia on glucose tolerance and plasma cortisol concentration in the surgical patient were assessed. Normal glucose tolerance and insulin release were observed under extradural anaesthesia, whereas general anaesthesia produced decreases in both glucose tolerance and insulin release. The plasma cortisol concentration was increased in both groups. These results indicate possible nutritional advantages in conducting surgery under extradural anaesthesia.

Adult↗
PubMed1978

Effects of ingestion of triglyceride or galactose on secretion of gastric inhibitory polypeptide and on responses to intravenous glucose in normal and diabetic subjects.

Responses of plasma immunoreactive gastric inhibitory polypeptide (IRGIP) to oral triglyceride or galactose were compared in normal and mildly diabetic (non-insulin-dependent) subjects. After triglyceride the responses of IRGIP were similar, but after galactose those of the diabetics were slightly exaggerated. Both stimuli evoked increments of plasma immunoreactive glucagon (IRG) in diabetics but not in normal subjects. Plasma immunoreactive insulin (IRI) did not change. In normal subjects given oral triglyceride or galactose followed by intravenous (I.V.) glucose the early-phase response of plasma IRI was enhanced and glucose tolerance improved. In the diabetics, oral triglyceride did not affect insulin release or glucose tolerance after I.V. glucose; oral galactose elicited a slight increase of insulin release without improving glucose tolerance. In the diabetics the rise of plasma IRG after ingestion of triglyceride or galactose was maintained after I.V. glucose. It is concluded that endogenous GIP is insulinotropic and that there is partial resistance to this action in diabetes. The results were compatible with feedback inhibition of GIP secretion by insulin and with the suggestion that the rise of plasma IRG associated with secretion of GIP in diabetics may be due to the glucagonotropic action of this peptide.

Administration, Oral↗
PubMed1978

Test of the generality of Bobrow and Bower's comprehension hypothesis.

In a test of the generality of the comprehension hypothesis, EMR children were assigned, following pretraining measures, to experimental(n = 24) and control (n = 12) conditions. The experimental group was given intensive training with both self-generated and supplied links, while the control group participated in the same training format but without mediational instruction. Posttraining measures strongly supported the applicability of the comprehension hypothesis to the associative learning of EMR children. Superior associative learning and greater comprehension occurred under generate as compared to supplied conditions.

Association Learning↗
PubMed1978

Facilitative effect of mnemonic strategies on multiple-associate learning in EMR children.

The efficacy of mnemonic strategy training for multiple-associate learning was examined. Following pretraining measures of multiple-associate learning and general memory skills, 33 young EMR children were randomly assigned to one of three conditions: imagery, rote repetition, or control. Each group participated in a story and game program for 5 hours over a 2-week period, which, depending on condition, involved intensive training in the use of either imagery or rote repetition or no direct mnemonic training. Posttraining measures of children who received mnemonic training showed marked improvement, with imagery being superior (p less than .01) to rote repetition.

Association Learning↗
PubMed1978

Cognitive training for EMR children: choosing the best alternative.

Twenty-eight EMR children participated in an 8-week training program on choosing the best alternative. The training was presented within the context of small-group discussions of familiar social problems and participation in table games. A control group (n = 28) engaged in similar activities but without specific cognitive training. The experimental group's posttest scores were far superior (p is less than .001) to those of the control group, an finding that suggests a major experiential component in the deficit in problem-solving skills typical of EMR children and provides strong support for the efficacy of early intensive cognitive training.

Child↗
PubMed1977

Hypersecretion of gastric inhibitory polypeptide following oral glucose in diabetes mellitus.

Gastric inhibitory polypeptide (GIP) is insulinotropic and is released after ingestion of glucose in normal man. Changes in plasma immunoreactive gastric inhibitory polypeptide (IRGIP) were therefore studied during a 50-gm. oral glucose tolerance test in 10 normal subjects and 20 subjects with maturity-onset diabetes mellitus. The diabetics were nonobese and treated by diet alone; they exhibited exaggerated increments of plasma IRGIP in association with delayed and diminished peak increases in plasma immunoreactive insulin, suggesting relative failure of the beta-cell response to GIP. The diabetic subjects also showed a paradoxic rise in mean plasma immunoreactive glucagon, with a peak coinciding with that of plasma IRGIP. It is suggested that the defective beta-cell response may lead to diminished feedback inhibition of GIP secretion by insulin in diabetes mellitus and that the glucagonotropic action of GIP may be expressed under these conditions.

Adolescent↗
PubMed1976

A new technique for long-term recording of eye movements in infants.

A device for recording eye movements from infants over long time periods is described. The device consists of an infrared light-emitting diode and a phototransistor mounted in a small package which covers one eye. The eyepiece is insensitive to EEG, EKG, or EMG potentials, and avoids irritation of the infant's skin from application of electrode paste. Detection of eye movements compares favorably to conventional eye movement electrodes.

Electronics, Medical↗
PubMed1976

Inhibition of actions of glucagon in adipocytes by gastric inhibitory polypeptide.

Possible interactions between gastric inhibitory polypeptide (GIP) and glucagon were investigated in rat adipocytes. GIP was nonlipolytic and inhibited lipolysis stimulated by glucagon but not that stimulated by secretin or vasoactive intestinal polypeptide (VIP). GIP competed with 125I-glucagon for binding to adipocyte receptors, and at physiologic concentrations inhibited the stimulation of AMP produced by glucagon. Thus GIP acts as an inhibitor of actions of glucagon on adipocytes and may be a physiologic modulator of effects of glucagon.

Adipose Tissue↗