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Biomedical subjects

G H Anderson

Publications and source records attributed to G H Anderson.

At least 109 records · Page 6Linked to original sources
PubMed1987

Effect of modifying the rate of digestion of a food on the blood glucose, amino acid, and endocrine responses in patients with cirrhosis.

To see whether foods with slower rates of digestion may benefit the metabolic abnormalities seen in cirrhosis, the same food, processed in two different ways, was fed to seven patients with cirrhosis. The breakfast of lentils processed by prolonged heating, to produce more rapid in vitro digestion, resulted in a significantly higher incremental rise in large neutral amino acid levels at 60 min (p less than 0.02) and a tendency for a more rapid rise in total amino acid concentrations by comparison with conventionally cooked lentils with slower in vitro digestion rates. After more rapidly digested lentils, incremental levels of branched-chain amino acids were also higher at 60 min (67 +/- 9, p less than 0.001) despite a greater overall insulin response. Comparable incremental amino acid areas after both meals suggested that the total amount of amino acids absorbed was not influenced by processing. Greater blood glucose, insulin, and gastric inhibitory polypeptide responses were seen after the more processed meal with no significant differences in pancreatic glucagon, entroglucagon, or neurotensin levels. Processing a food to alter the rate of digestion may therefore be used to manipulate amino acid, glucose, and endocrine responses in cirrhosis.

Aged↗
PubMed1986

Difficulties in the prospective diagnosis of functional adrenal diseases by CT.

The accuracy of prospective diagnosis of functional adrenal disorders by computed tomography (CT) was evaluated in 65 patients strongly suspected of having such disorders. Thirty-seven patients also underwent adrenal venography and selective adrenal venous sampling. Of the 65 patients, 21 had a hyperfunctioning cortical adenoma, 25 had cortical or medullary hyperplasia, and 11 pheochromocytoma, while 10 had no functional adrenal disease. Diagnosis by CT alone was correct in 66%; diagnosis by CT and venous sampling was correct in 89%. Incorrect prospective CT diagnosis resulted most often from a normal appearance of functionally hyperplastic glands (9 cases), nodular hyperplasia simulating a focal adenoma (8 cases), or an incidental nonfunctioning mass (3 cases). This study emphasizes the need to correlate CT findings with biochemical evaluation and the usefulness of venous sampling in selected cases to avoid inappropriate surgery. When CT is interpreted in correlation with complete biochemical analysis, correct diagnosis can usually be made. A small number of cases may still require adrenal venous sampling.

Adenoma↗
PubMed1986

The effects of early dietary experience on subsequent protein selection in the rat.

Two series of experiments were designed to investigate the effects of protein composition of the first solid food consumed by young rat pups on their subsequent protein intake after weaning. In the first series of experiments, pups were allowed access to the maternal diet between 17 and 21 days of age, then weaned to a choice of 10% and 60% casein diets at 21 days. Pups with access to a maternal diet containing 39% casein selected high levels of protein (calculated as % of total calories selected as protein: 50 +/- 1% (access) vs. 29 +/- 3.5% (no access), p less than 0.05), whereas lower levels of protein were selected following access to a maternal diet containing 26% casein (16 +/- 1.1% (access) vs. 23 +/- 1% (no access), p less than 0.05) or 10% casein (27 +/- 3.9% (access) vs. 39 +/- 3.7% (no access), p less than 0.05). In a second series of experiments, the influence of early diet composition on subsequent protein selection was confirmed by prematurely weaning rats at 17 days of age to either 39% or a 10% casein diet. When given a choice of 10% and 60% casein diets at 21 days, pups selected higher levels of protein if weaned to a 39% casein diet as compared to a 10% casein diet (37 +/- 5.0% vs. 19 +/- 3.5% (p less than 0.05) for the first experiment and 43 +/- 3.0% vs. 26 +/- 4.0% (p less than 0.05) in a second experiment). It was concluded that the level of protein selected by young rats is positively correlated with the protein concentration of their first solid food.

Animals↗
PubMed1986

Hypothalamic catecholamine metabolism in diabetic rats: the effect of insulin deficiency and meal ingestion.

The effect of moderate insulin deficiency of 2 weeks in duration on hypothalamic catecholamine metabolism in food-deprived and meal-fed rats was evaluated. Hypothalamic tyrosine content in food-deprived (from 0700 to 1600 h), diabetic rats was normal. Also normal were the rates of 3,4-dihydroxyphenylalanine accumulation following aromatic amino acid decarboxylase inhibition, norepinephrine and 3,4-dihydroxyphenylethylamine (dopamine) clearance after tyrosine hydroxylase inhibition, and intraneuronal amine accumulation following monoamine oxidase inhibition. Differences in hypothalamic amine metabolism were apparent, however, when diabetic and normal rats were fed 2-g meals. The 3-methoxy-4-hydroxyphenylethyleneglycol sulfate accumulation rate was depressed in diabetic rats by the carbohydrate meal but was stimulated by the tyrosine-supplemented protein meal. In contrast, the tyrosine-supplemented diet had no effect on 3,4-dihydroxyphenylacetic acid accumulation in diabetic animals, whereas the production rate in normal rats was increased. We conclude that normal responses occurring in hypothalamic catecholamine metabolism after the consumption of a meal are modified by the presence of diabetes.

Animals↗
PubMed1986

Proteins and amino acids: effects on the sympathetic nervous system and blood pressure regulation.

Many functions of the brain and the sympathetic adrenal system are influenced by those amino acids that exert precursor control over neurotransmitter synthesis. One of the functions affected is regulation of blood pressure. Therefore, the purpose of this review is to describe how food proteins and amino acids affect the synthesis of neurotransmitters and their regulation of blood pressure.

Amino Acids↗
PubMed1986

Effect of sodium balance and calcium channel-blocking drugs on plasma aldosterone responses to infusion of angiotensin II in normal subjects and patients with essential hypertension.

To study the role of calcium movements in mediating the effects of sodium chloride on the response of plasma aldosterone to angiotensin II (AII), we administered calcium channel-blocking drugs (nifedipine and diltiazem) and calcium infusions to normal subjects during high and low sodium intakes before and after AII infusion. AII was also infused in 13 patients with essential hypertension eating a high sodium diet. In preliminary studies, the effects of nifedipine (20 mg, orally) on blood pressure, PRA, plasma aldosterone, and plasma cortisol concentrations were determined. Sensitivity to infused AII was calculated as the slope of the linear regression of the increase in plasma aldosterone as a function of the AII infusion rate (nanograms per dl/ng AII/kg X min). During sodium restriction (10 meq Na/day), both drugs significantly (P at least less than 0.05) reduced AII sensitivity. During the high sodium diet (200 meq Na/day), only diltiazem decreased AII sensitivity, and the reduction was less (P less than 0.05) than that during the low sodium diet. There was a significant (P less than 0.001) inverse correlation between the initial plasma aldosterone sensitivity to AII and the change in sensitivity induced by the calcium channel-blocking drugs in normal subjects (r = -0.89) and hypertensive patients (r = -0.70). Five hypertensive patients had greater than normal aldosterone sensitivity to AII, which was significantly (P less than 0.05) reduced by nifedipine. Calcium infusion increased the aldosterone sensitivity to AII during the low sodium diet, but not during the high sodium diet. The results suggest that in normal subjects, increased plasma aldosterone responses to AII induced by reduction in sodium intake are partially mediated by increased extracellular to intracellular calcium movements, since they are blocked by the structurally different calcium channel-blocking drugs nifedipine and diltiazem. In hypertensive patients eating a high sodium diet, increased aldosterone responses to AII infusion were blocked by nifedipine, indicating that they are at least partly mediated by increased extracellular to intracellular calcium flux.

Adult↗
PubMed1986

Hemoptysis as a presenting symptom of pheochromocytoma.

Hemoptysis as a presenting symptom of pheochromocytoma has not received wide recognition. This report describes a patient with a pheochromocytoma complicated by hemoptysis. The hemoptysis occurred during paroxysms of hypertension and was cured by surgical removal of the tumor. Knowledge of this association could lead to more rapid diagnosis.

Adrenal Gland Neoplasms↗
PubMed1985

Food intake suppression by histidine.

Following injection of histidine (as 1-histidine monohydrochloride, 500 mg/kg, IP) rats showed a suppression of total food intake within the first 2 hours of a 12 hour daily feeding period but not if the rats were adapted to a 4 hour daily feeding period. Furthermore, rats adapted to a nocturnal as compared to a diurnal 12 hour feeding period showed a greater response (50% vs. 20% suppression of feeding) to histidine. Overall, within an experiment, food intake suppression correlated with the histidine dose (0, 125, 250, 375 and 500 mg/kg; for mean response r(3) = 0.90, p less than 0.05) although the lowest dose measured to be effective in a cross-over design experiment was 375 mg/kg. No differential effect upon protein or carbohydrate intake was observed in any of the studies. The effects of injections of 250 and 500 mg/kg histidine on food intake were associated with significant elevations of brain histidine and histamine. We conclude that histidine, possibly by changes in brain histidine, influences total food intake but not macronutrient selection.

Animals↗
PubMed1985

Human milk feeding.

This article examines the factors to be considered in providing optimal nutritional care to the infant fed human milk. These factors include the nutrient and non-nutrient composition of human milk, nutrient requirements of full-term and premature infants, the timing and need for supplementary or complementary foods, and the role of milk-based formulas.

Adult↗
PubMed1985

The effect of insulin deficiency, dietary protein intake, and plasma amino acid concentrations on brain amino acid levels in rats.

The effect of diabetes (streptozotocin, 65 mg/kg ip), dietary protein intake (15-60%), and plasma amino acid concentrations on brain large neutral amino acid levels in rats was examined. After 20 days, the plasma concentrations of methionine and the branched chain amino acids (BCAA), valine, isoleucine, and leucine were increased in diabetic rats. In brain tissue, methionine and valine levels were increased but threonine, tyrosine, and tryptophan concentrations were depressed. Increased protein consumption promoted a diabetic-like plasma amino acid pattern in normal rats while enhancing that of diabetic animals. However, with the exception of threonine, glycine, valine, and tyrosine, there was little effect on brain amino acid levels. A good association was found between the calculated brain influx rate and the actual brain concentration of threonine, methionine, tyrosine, and tryptophan in diabetic animals. There was no correlation, however, between brain influx rate and brain BCAA levels. Thus, the brain amino acid pattern in diabetes represents the combined effects of insulin insufficiency and composition of the diet ingested on plasma amino acid levels as well as metabolic adaptation within the brain itself.

Amino Acids↗
PubMed1985

Left neck mass.

Explore the source record for details and available documents.

Head and Neck Neoplasms↗
PubMed1985

Colposcopic accuracy in the diagnosis of microinvasive and occult invasive carcinoma of the cervix.

One hundred eighty patients with microinvasive and occult invasive squamous cell carcinoma of the cervix who were examined by colposcopy during a ten-year period are reviewed. Forty-two percent of patients with microinvasive carcinoma and 28% of patients with occult invasive carcinoma had an unsatisfactory colposcopic examination. Colposcopy led to the correct management in 90% of patients with occult invasive cancer and in 84% of patients with microinvasive carcinoma. Colposcopy appeared to be less sensitive in detecting microinvasive lesions than in detecting occult carcinoma. Two-thirds of the errors made were colposcopist-related, either failure of interpretation or protocol violation. A small but definite group of patients will have lesions whose colposcopic appearance is not sufficiently distinct or characteristic to permit a diagnosis of early invasion.

Adult↗
PubMed1985

Role of angiotensin in lethal cerebral hypoperfusion during treatment of acute hypertension.

A 23-year-old man developed lethal cerebral hypoperfusion associated with angiographically demonstrable cerebral arterial spasm while being treated for acute angiotensinogenic hypertension due to a traumatic coarctation of the aorta. This complication occurred even though the treatment maintained his blood pressure at normotensive to mildly hypertensive levels, without producing more than rare and fleeting periods of hypotension. To explain this enigmatic development, we propose that the high concentration of angiotensin II in the blood constricted the cerebral arteries and thus prevented adequate cerebral autoregulation when his blood pressure was lowered by drug therapy.

Acute Disease↗