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Biomedical subjects

G H Anderson

Publications and source records attributed to G H Anderson.

At least 91 records · Page 5Linked to original sources
PubMed1988

Organisation and results of the cervical cytology screening programme in British Columbia, 1955-85.

A screening programme to detect preinvasive carcinoma of the cervix was started in British Columbia in 1949. Since 1970 the number of women who have been screened at least once has been maintained at about 85% of the population at risk. More than 500,000 cervical smears are being examined each year in the central laboratory. There has been an appreciable increase in the number of cases and rates of carcinoma in situ seen since 1970, particularly in women between 20 and 30 years of age. Since the programme started over 26,000 cases of squamous carcinoma in situ have been detected and treated. The incidence of clinically invasive squamous carcinoma of the cervix has fallen by 78% during the period under review, and mortality from squamous carcinoma of the cervix has fallen by 72%. A colposcopy programme, introduced throughout British Columbia over the past 12 years, has been important in reducing the problems of managing preinvasive lesions, particularly in younger women. It is concluded that the reduction in morbidity and mortality from invasive squamous cancer of the cervix in British Columbia over the past 30 years is directly attributable to the province wide screening programme and that a large potential increase in invasive cervical cancer rates among younger women is being prevented.

Adolescent↗
PubMed1988

The effect of lowering plasma tryptophan on food selection in normal males.

The effects of a tryptophan deficient amino acid mixture on food selection were studied using a double-blind counterbalanced crossover design in normal male subjects. The subjects ingested tryptophan deficient or nutritionally balanced amino acid mixtures in the morning after an overnight fast. Five hours after the tryptophan deficient amino acid mixture plasma tryptophan was only 19% of the level found five hours after the nutritionally balanced amino acid mixture. After both mixtures subjects were allowed to select lunch from a buffet. The tryptophan-deficient mixture was associated with a modest but significant decline in protein selection with no significant alteration in selection of carbohydrate, fat or total kcal. Our results suggest that 5-hydroxytryptamine is involved in the control of protein selection in humans.

Adult↗
PubMed1988

Prediction of renovascular hypertension. Comparison of clinical diagnostic indices.

One hundred and six patients were determined to have renovascular hypertension (RVH) out of 3520 patients with hypertension referred by their physicians for a 1-day blood pressure study (1-day BP study) to evaluate the presence of secondary forms of hypertension. The clinical indices (including serum potassium and creatinine concentrations) most likely to predict RVH were analyzed. Patients unlikely to have RVH were those with a diastolic blood pressure (DBP) less than or equal to 90 mm Hg (with or without BP medication) with a serum potassium concentration less than 3.4 mEq/L. A two- to threefold increased prevalence of RVH was associated with DBP greater than 110 mm Hg, an age of onset of hypertension of 51-69 years, or age of onset greater than 60 years with a DBP less than or equal to 100 mm Hg. A four- to sixfold increase came with an age of onset greater than 60 years, serum potassium (with or without BP medication) 2.9-3.3 mEq/L, or serum potassium less than 3.4 mEq/L with DBP greater than 90 mm Hg. A seven- to ninefold increase came with age of onset greater than 60 years with DBP greater than 110 mm Hg or serum potassium (with or without BP medication) of 2.3-2.8 mEq/L.

Adult↗
PubMed1988

Effects of thyroid function on blood pressure. Recognition of hypothyroid hypertension.

Hypothyroidism has been known to be associated, at times, with diastolic hypertension. We have found in 40 thyrotoxic patients that the induction of hypothyroidism by radioiodine therapy significantly increased diastolic blood pressure, raising it above 90 mm Hg in 16 (40%) of the patients. Restoration of euthyroidism with thyroxine administration significantly reduced the systolic and diastolic blood pressures in these patients, with a fall in diastolic pressure below 90 mm Hg in nine of 16 patients. The prevalence of hypothyroidism was determined by measurements of serum thyroxine and thyrotropin concentrations in 688 consecutive hypertensive patients, referred for evaluation and therapy of their hypertension. Hypothyroidism was found in 25 (3.6%) of the patients. Restoration of normal serum thyroxine and thyrotropin levels with thyroid hormone replacement therapy lowered diastolic blood pressure to levels below 90 mm Hg in 32% of these patients who could be followed up after withdrawal of all antihypertensive drug therapy when euthyroidism had been restored (i.e., 1.2% of the 688 patients). It is concluded that diastolic hypertension resulting from hypothyroidism is a relatively common disorder, present in 1.2% of our referred hypertensive patients, that should be sought and treated.

Adult↗
PubMed1988

Effects of aspartame and phenylalanine on meal-time food intake of humans.

This article reviews data relevant to the hypothesis that aspartame may have a unique effect on meal-time food intake regulation due to its amino acid composition and in addition to its effects as a high intensity sweetener. It is concluded that future studies involving aspartame should be directed towards developing a fundamental understanding of the effects of high intensity sweeteners on food intake, and not give undue attention to putative actions based on its amino acid constituents.

Amino Acids↗
PubMed1988

Relationship between fasting serum tryptophan/large neutral amino acid ratio and reported hunger in subjects with diabetes.

Food intake regulation is influenced by serum amino acid (AA) ratios. The objectives of this study were to determine whether non-obese subjects with diabetes have normal serum AA ratios, and to see if AA ratios relate to perceived hunger. We therefore measured fasting serum AA in nine normal subjects on two occasions and 19 patients with diabetes on four occasions over a two month period. At the time of the blood samples, the subjects with diabetes were asked to rate how hungry they felt on a scale of -3 (very hungry) to +3 (very full). There were no significant differences between the mean AA ratios of normal and diabetic subjects. There was a positive correlation between reported hunger score and the ratio of serum tryptophan (TRP) to the sum of the concentrations of the other large neutral AA (LNAA) (r = 0.286, n = 78, p less than 0.05). The relationships between hunger and other AA ratios were not significant. Variations of the TRP/LNAA ratio within each subject did not relate to differences in hunger from day-to-day. However, there was a positive correlation between the mean TRP/LNAA ratio and mean hunger score of the different subjects (r = 0.495, n = 19, p less than 0.05). The relationships between TRP/LNAA ratio and body weight or hunger score were not significant. It is concluded that the serum AA ratios are normal in patients with diabetes. The data is consistent with the hypothesis that a low serum TRP/LNAA ratio causes increased feelings of hunger in different individuals.

Adult↗
PubMed1988

Abnormal orthostatic changes in blood pressure and heart rate in subjects with intact sympathetic nervous function: evidence for excessive venous pooling.

The normal ranges of orthostatic changes in blood pressure and heart rate have been defined in 92 individuals aged 18 to 64 years. In 34 individuals whose symptoms (especially orthostatic light-headedness) suggested cerebral ischemia, but in whom none of the known causes of orthostatic hypotension could be identified, we have found one or more of five theoretically possible orthostatic circulatory derangements: systolic hypotension, diastolic hypotension, diastolic hypertension, excessive narrowing of the pulse pressure, and tachycardia after standing for at least 3 minutes. The orthostatic disorders of blood pressure and heart rate identified in the 34 patients were significantly reduced, almost always into the normal range, by external pressure of 45 to 50 mm Hg applied through an inflatable pressure suit. After labeling with sodium pertechnetate Tc 99m and reinjecting the erythrocytes contained in 3 to 6 ml blood, external gamma counting over a fixed site in the calf, both in the recumbent and in the standing posture, showed excessive gravitational pooling of blood in the legs of five patients with orthostatic diastolic hypertension, of four with orthostatic narrowing of the pulse pressure, and of 10 with orthostatic tachycardia alone. Plasma norepinephrine concentrations were usually normal in recumbency and elevated above normal limits during standing for 15 to 30 minutes in the 18 patients so observed. Red cell mass, plasma volume, and circulating blood volume were subnormal in more than half the seven patients in whom these measurements were made. We conclude that most of the patients with idiopathic sympathicotonic abnormalities of orthostatic blood pressure control have a venous pooling syndrome often aggravated by hypovolemia, the cause(s) of which remains to be determined.

Adolescent↗
PubMed1987

Infant feeding practices: 1984-85 versus 1977-78.

In 1979 and 1980 the Canadian Paediatric Society's Nutrition Committee published guidelines for professionals counselling mothers of infants on feeding practices. The practices in 1984-85 of mothers in Toronto were determined for comparison with the practices identified in a similar study conducted in Toronto and Montreal in 1977-78 to ascertain if practices had changed in favour of the recommendations. Between July 1984 and February 1985, 404 metropolitan Toronto mothers of infants were interviewed. Compared with the 1977-78 group of mothers, more of the 1984-85 mothers had chosen to breast-feed and fewer had stopped breast-feeding in the first month. As well, fewer of the 1984-85 infants had been fed unmodified cow's milk in the first 6 months of life and introduced to solid foods before 4 months of age. We conclude that major changes in infant feeding practices had occurred since 1977-78 and that the 1984-85 practices corresponded closely to the infant feeding guidelines.

Animals↗
PubMed1987

The role of an immunoperoxidase technique in the diagnosis of oral herpes simplex virus infection in patients with leukemia.

Laboratory techniques are often used to confirm a clinical diagnosis of oral herpes simplex virus (HSV) infection in patients with leukemia. In the present study, an immunoperoxidase technique (IPT) was used to examine smears taken from the oral mucosa of 44 patients with leukemia at Vancouver General Hospital. It was found that the IPT was as sensitive and specific as viral culture in confirming the presence of HSV. The IPT was found to be more predictive of symptomatic oral HSV disease than viral culture because it did not give positive results if there was only viral shedding in the absence of clinical disease. As the IPT is rapid and inexpensive as well as being specific, sensitive, and predictive, it has a definite role in the laboratory confirmation of oral HSV lesions in leukemics.

Acute Disease↗
PubMed1987

Phenylalanine and aspartame fail to alter feeding behavior, mood and arousal in men.

Two experiments were designed to investigate the neurobehavioral effects of phenylalanine (PHE; 0.84, 2.52, 5.04, and 10.08 g) and aspartame (APM; 5.04 and 10.08 g) on energy and macronutrient selection and on subjective feelings of hunger, mood and arousal in normal weight adult males. Neither phenylalanine nor aspartame altered mean energy intakes or macronutrient selection at a lunch begun 60 to 105 min after the amino acids were consumed. During this time, increased (p less than 0.05) visual analog scale (VAS) scores for emptiness, rumbling, weakness, degree of hunger and urge to eat were found in both experiments, but no treatment effects or interactions were seen for any variable in either experiment. Plasma PHE levels and ratios to other large neutral amino acids (NAA) rose significantly (p less than 0.05) after all treatments except 0.84 g PHE; plasma tyrosine (TYR) levels increased (p less than 0.05) only when greater than or equal to 2.52 g PHE was given. TYR/NAA ratios were higher (p less than 0.05) after 2.52 and 5.04 g PHE, and 10.08 g APM. No relationships were found between food intake and plasma amino acid levels. We conclude that, in normal weight men, PHE and APM, in doses up to 10 g, do not affect short-term energy and macronutrient intakes, or subjective feelings of hunger, mood and arousal.

Adult↗
PubMed1987

Food intake and selection after peripheral tryptophan.

Two studies investigated the effects of peripheral (IP) administration of the dietary indispensible amino acid tryptophan, on food intake and macronutrient selection in rats adapted to a 12 hr nocturnal feeding period and a choice of 10% and 60% casein diets. In a dose-response study (35, 55, 75, 95, 115 mg/kg), the threshold dose of 75 mg/kg produced a significant reduction in total food intake (3.6 to 2.3 g, p less than 0.05) during the first hour of feeding. The reduction in carbohydrate intake (2.1 vs. 1.2 g, p less than 0.05) was greater than that for protein intake (1.6 vs. 1.1 g, p less than 0.05). Twelve hr total food intake was also decreased (20.9 to 19.5 g, p less than 0.05) and this was attributable to decreased carbohydrate intake (13.2 to 11.8 g, p less than 0.05). In a second study designed to determine if tryptophan's effects were mediated by the central nervous system, brain tryptophan uptake was blocked by co-injecting valine with tryptophan. The significant reduction in first hour total food intake by tryptophan was not prevented by co-injection of an equal quantity of valine (3.5 to 1.8 g, p less than 0.05). Again the suppression of carbohydrate intake (2.0 to 0.9 g p less than 0.05) was greater than that for protein intake (1.5 to 0.9 g, p less than 0.05). This dose of valine significantly reduced brain tryptophan uptake by 16% (21.3 to 17.8 micrograms/g, p less than 0.05) and when administered alone did not affect first hour total food intake (3.1 vs 3.2 g).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

The results of cryosurgical treatment of cervical intraepithelial neoplasia at one, five, and ten years.

The results after cryosurgical treatment of cervical intraepithelial neoplasia at 1, 5, and 10 years are reported. Ninety-four percent of the 1675 patients eligible for assessment at 1 year were successfully treated, with only 5.6% lost to follow-up. After 5 years, 14% of patients were lost to follow-up, but the corrected success rate remained essentially unchanged. No major differences in success rates were noted for the various histologic grades of cervical intraepithelial neoplasia treated. A small but definite percentage of patients developed further disease over the ensuing years, indicating the need for long-term, continued surveillance of these patients.

Adult↗
PubMed1987

Prevalence, natural history and surgical treatment of exophthalmos.

The 95% confidence limits of exophthalmometer measurements have been defined by a single observer in 105 individuals who had no known thyroid disease, and found to be 10.5-18.8 mm. Measurements in 308 patients with thyrotoxicosis have shown that exophthalmos (greater than 19 mm) of one or both eyes was present in 21.3% of the patients. Among the 122 thyrotoxic patients whose exophthalmometer measurements could be performed annually for 3-19 years after correction of the thyrotoxicosis (usually with 131I), exophthalmos remained stable in 78.7%, worsened in 15.6% and became less severe in 5.7% of the patients. Transantral decompression of the orbits was performed in 15 patients with rapid subjective improvement in all and reduction in exophthalmometer measurements of 3.6 +/- 0.5 (mean +/- SEM) mm, and no serious side-effects. In view of these findings, transantral decompression should be considered more frequently in the treatment of severe or cosmetically damaging exophthalmos.

Adolescent↗
PubMed1987

Effect of sodium balance and calcium channel blocking drugs on blood pressure responses.

To study the role of calcium movements in mediating the effects of sodium chloride on the response of blood pressure to angiotensin II (ANG II), we infused ANG II before and after giving calcium channel blocking drugs (nifedipine and diltiazem) and calcium infusions to normal subjects during high and low sodium intakes. ANG II was also in nine patients with essential hypertension eating a low sodium diet. In preliminary studies, the effects of nifedipine, 20 mg p.o., on blood pressure and plasma renin activity were determined. Sensitivity to infused ANG II was calculated as the slope of the linear regression of the increase in diastolic blood pressure (DBP) expressed as a function of the ANG II infusion rate (mm Hg/ng ANG II/kg/min). During intake of a high sodium diet (Na, 200 mEq/day) both drugs significantly (p less than 0.05) reduced ANG II sensitivity, while on a low sodium diet (10 mEq Na), neither drug reduced ANG II sensitivity. There was a significant (p less than 0.001) inverse correlation between the initial ANG II-DBP sensitivity and the change in sensitivity induced by the calcium channel blocking drugs in normal subjects (r = -0.78) and in hypertensive patients (r = -0.70). Five hypertensive patients had greater than normal ANG II-DBP sensitivity that was significantly (p less than 0.05) reduced by nifedipine. Calcium infusion did not affect the ANG II-DBP sensitivity on either diet. The results suggest that in normal subjects increased DBP responses to ANG II, induced by an increase 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 on a low sodium diet, increased DBP responses to ANG II infusion were blocked by nifedipine, indicating they are at least partly mediated by increased extracellular to intracellular calcium flux.

Adult↗