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Biomedical subjects

G H Anderson

Publications and source records attributed to G H Anderson.

At least 37 records · Page 2Linked to original sources
PubMed1997

Evidence for histamine involvement in the effect of histidine loads on food and water intake in rats.

We examined the hypothesis that histidine is a regulator of short-term food and water intake in rats and that this control is through histidine's action as a precursor for histamine. The primary objectives were to measure food and water intake after histidine monohydrochloride monohydrate (His-HCl) given by intragastric (IG) and intraperitoneal (IP) routes of administration and to measure feeding and drinking responses to histidine when given after blockade of the histaminergic pathway by chlorpheniramine (CPA) and alpha-fluoromethylhistidine (FMH). Eight experiments were conducted using a back-to-back design. Rats were given treatment by IP or IG administration, and food and water intake was measured during time periods of 0-1, 1-2, 2-3 and 3-14 h. Histidine consistently reduced food intake with the sensitivity to IP much greater than to the IG route. The effect of histidine given by IP or IG on water intake was similar, generally causing an increase at least in the first hour. Histidine's action was not accounted for by its energy, pH or nitrogen content. Because FMH, which blocks the enzyme converting histidine to histamine, partially reversed the effect of histidine on food and water intake, these results support the hypothesis that histidine regulates food and water intake, at least in part, through its precursor control of histamine.

Administration, Oral↗
PubMed1997

Cytological aspects of uterine cervical adenocarcinoma, adenosquamous carcinoma and combined adenocarcinoma-squamous carcinoma: appraisal of diagnostic criteria for in situ versus invasive lesions.

This paper reports the cytological findings based on air-dried smears in a retrospective series of 143 cases of endocervical adenocarcinoma, combined adenocarcinoma-squamous carcinoma and adenosquamous carcinoma drawn from the files of the BC Cancer Registry. Cervical cytology smears were available before biopsy in 131 patients, but in 18 cases the cytology showed no abnormality. Malignant changes or high-grade atypia of glandular and/or squamous cells (defined as moderate or severe dyskaryosis) were detected in 103 cases. In 46 cases, only a high-grade squamous abnormality was detected. Low-grade glandular and/or squamous lesions were detected in nine cases and one showed atypical endometrial-type glands. The cervical smears of 64 cases were reviewed in detail to determine the important cytomorphological criteria of in situ and invasive adenocarcinoma in air-dried smears, the technique used for preparing PAP smears in British Columbia. Endocervical cells were absent in four cases. Numerous (> 10) groups of glandular cells were present in 51 cases. Important clues to the diagnosis of adenocarcinoma included crowding of nuclei, stratification of nuclei, loss of polarity, syncytial balls and papillary groups of glandular cells, nuclear enlargement, nuclear pleomorphism, and the presence of free-lying atypical glandular cells. Nuclear hyperchromatism, chromatin pattern, nuclear borders, nuclear membranes, and numbers and morphology of nucleoli were not helpful criteria in our material. Criteria enabling reliable distinction between in situ and invasive adenocarcinoma and/or mixed adenocarcinoma-squamous carcinoma could not be established.

Adenocarcinoma↗
PubMed1997

Effect of a cholecystokinin-A receptor blocker on protein-induced food intake suppression in rats.

To test the hypothesis that only dietary protein (Pro; chicken egg albumin) and not amino acids (AA), carbohydrates (CHO; cornstarch), or fats (Fat; corn oil) produces a satiating effect via cholecystokinin (CCK) receptors, devazepide was coadministered with each macronutrient. Given alone (in 4 ml ig), Pro (0.75, 1.0, and 1.5 g), AA (1.0 g), CHO (1.4 g), and Fat (2.4 g) suppressed (P < 0.05) food intake in the first hour by 0.5, 0.8, and 1.1 g; 1.9 g; and 1.0 g, respectively, and in the first 2 h of feeding by 0.8, 1.2, and 1.3 g; 1.7 g; 0.7 g; and 1.5 g, respectively. When coadministered with devazepide (0.5 mg/kg body wt ig), the suppression of food intake caused by Pro, AA, CHO, and Fat treatments was modulated in the first hour by 60, 50, and 55%; 16%, 11%; and 10%, respectively, and during 0-2 h by 63, 92, and 54%; 29%; 0%; and -20%, respectively. Devazepide (0.5 mg/kg) given intraperitoneally also modulated Pro intake suppression during the first hour by 33% and during 0-2 h by 79%. Devazepide appears to interact with mechanisms of Pro-induced food intake suppression, but not AA-, Fat-, or CHO-induced food intake suppression. These studies provide evidence that CCK receptors play a role in Pro (albumin)- but not AA-, CHO (corn starch)-, or Fat (corn oil)-induced food intake suppression in rats.

Amino Acids↗
PubMed1996

Efficacy of the National Cholesterol Education Program Step I diet. A randomized trial incorporating quick-service foods.

OBJECTIVE: To determine the effect of incorporating quick-service meals into a Step I diet on the achievement of the National Cholesterol Education Program (NCEP) guidelines and on the blood lipid response of hyperlipidemic subjects (as possibly, the achievement of, and adherence to, dietary goals may be assisted by the inclusion of familiar foods, instead of their exclusion). METHODS: This was a randomized, parallel design study in free-living subjects. Hypercholesterolemic men and women (low-density lipoprotein cholesterol [LDL-C] level, 3.36 to 5.69 mmol/L [130 to 220 mg/dL]) who were consuming a high-fat diet (> 33% of total calories from fat) were randomly assigned to either a traditional NCEP Step I diet (n = 44) or an NCEP Step I diet with the incorporation of frequent quick-service meals (NCEP-QS, n = 45). RESULTS: After 8 weeks of treatment, both groups similarly reduced their reported dietary intakes of energy (approximately 30%), total percent fat (approximately 8%), percent saturated fat (approximately 3%), and cholesterol (approximately 38% to 28%). Both groups also experienced a decrease in the levels of total serum cholesterol (NCEP Step I diet, 8%; NCEP-QS Step I diet, 3%) and LDL-C (NCEP Step I diet, 10%; NCEP-QS Step I diet, 4%). However, compared with the group receiving the NCEP-QS Step I diet, the subjects who were consuming the NCEP Step I diet showed a significantly greater reduction in their total serum cholesterol and LDL-C levels over time (P < .05). Weight loss was significantly correlated (P < .001) with the decrease in the total serum cholesterol and LDL-C levels for all subjects combined. CONCLUSIONS: Hyperlipidemic subjects who were consuming an NCEP Step I diet, with or without the incorporation of quick-service meals, experienced a significant decrease in their total serum cholesterol and LDL-C levels, body weight, and reported fat intake. The beneficial responses in lipid levels were modestly mitigated in the quick-service diet group.

Adult↗
PubMed1996

Stage IA carcinoma of the cervix revisited.

OBJECTIVE: To examine some of the controversy that still exists regarding the definition and management of microinvasive or early invasive cervical carcinoma, in particular, the current concepts regarding the definition of these conditions and their inclusion into the staging system for cervical cancer. DATA SOURCES: A MEDLINE search was used to identify English-language reports of clinical and pathologic information on cervical cancer. Articles published during 1970-1993 were reviewed. METHODS OF STUDY SELECTION: Articles were selected for review if the information published contained data regarding measured depth of invasion, histologic examination of lymph nodes, and lymphatic vascular space status with these tumors. TABULATION, INTEGRATION, AND RESULTS: Results from the studies were pooled to determine the correlation between depth of invasion with the likelihood of nodal disease and recurrence, both with and without lymphatic vascular space involvement. These studies indicated that the likelihood of recurrence and death from cancer, together with the presence of nodal metastasis, appears to be directly related to the depth of tumor invasion. The relative importance of factors such as lymphatic space involvement will likely remain controversial because they may not be independent prognostic factors. CONCLUSION: Review of the literature suggests that although no uniform opinion exists as to how these conditions should be described or managed, the evidence indicates that some modifications to the 1985 staging system for cervical cancer could be made to better categorize patients with these conditions and also, perhaps, provide guidelines for management.

Female↗
PubMed1996

Mechanisms of orthostatic hypotension and tachycardia in patients with pheochromocytoma.

We have explored the pathophysiological mechanisms of orthostatic hypotension and orthostatic tachycardia, found to be present in 83% and 61% respectively of 18 patients with subsequently proven pheochromocytoma. Orthostatic increases in plasma norepinephrine (NE) concentrations were significantly greater in the patients than in normal control subjects. Intravenous infusions of NE at 1, 2, 4, 8, and 16 micrograms/min induced similar increases in plasma NE levels but smaller increments in systolic and diastolic BP in the pheochromocytoma patients than in normal control subjects. This was reflected by a significantly greater increment in plasma NE concentration required to raise systolic BP by 15 mm Hg and diastolic BP by 7 mm Hg in the pheochromocytoma patients than in the normal subjects (P < .05 and P < .01, respectively). Measurements of venous contractile responses to locally infused NE by the dorsal hand vein (LVDT) technique revealed significantly reduced slopes of the regressions of log NE infusion rate on change in venous diameter in the pheochromocytoma patients compared with normal subjects. The results indicate reduced responsiveness of the vasculature to NE in patients with pheochromocytoma, probably due to down-regulation of alpha-adrenergic receptors resulting from persistent elevation of the physiological agonist NE. This was shown by other authors to be present in circulating platelets. The pathophysiological importance of the subnormal venous responses to the orthostatic hypotension and tachycardia in the patients were supported by the finding that the orthostatic changes were corrected by lower body compression to 45 mm Hg with a MAST pressure suit.

Adolescent↗
PubMed1996

Forty years of repeated screening: the significance of carcinoma in situ.

Two cohorts of women born in 1914-18 and 1929-33 who participated in a cervical screening programme have been followed for over 40 years. Age-specific incidence rates of squamous carcinoma of the cervix by rank of smear and length of interval between smears are reported. The younger cohort, who had undergone more frequent screening, had lower rates of invasive disease. From these incidence rates, estimates of false-negative rates and regression rates for carcinoma in situ have been made. The false-negative rate was estimated to be about 15%. Regression seemed more frequent in younger than in older women. For the younger cohort it was estimated to be 72% and in the older 47%. A comparison of the rates of in situ carcinoma with those of invasive disease suggests that the screening of the younger cohort reduced the rate of invasive disease to at least one-half or one-third of what it would have been if screening had commenced later. Rates of disease appear less dependent on age than previously thought and are consistent with causation by an infective agent.

Adult↗
PubMed1996

The potential for serious consequences from misinterpreting normal responses to the rapid adrenocorticotropin test.

Despite unequivocal published evidence that patients with subnormal hypothalamic-pituitary-adrenal (HPA) function may respond normally to ACTH, such normal results are still considered reliable indications of unimpaired HPA function. This view was tested in four patients with clinical features suggesting corticotropin deficiency, in whom cosyntropin (0.25 mg, i.v.) raised serum cortisol above 560 nmol/L (20 micrograms/dL) at 1 h. All four patients had subnormal responses to metyrapone and excellent persistent improvement during subsequent glucocorticoid therapy. Serum cortisol concentrations 1 h after cosyntropin treatment in these patients closely resembled cortisol concentrations 1 h after uncomplicated cholecystectomy in six other patients. However, the rapid ACTH test in the patients with hypopituitarism failed to indicate whether more prolonged stimulation by ACTH or their endogenous stress would stimulate the normal continuing rise in serum cortisol, which reached 1358 +/- 170 nmol/L (+/- SE) 5 h after the incision in the cholecystectomized patients. As the three hypocorticotropic patients who were recognizably stressed had unstressed serum cortisol levels despite persistent adrenocortical reserve (shown by their ACTH responses) and recovered during glucocorticoid therapy, the ACTH test, if interpreted to indicate normal HPA function, would probably have had disastrous consequences. We conclude that a normal response to the rapid ACTH test can be dangerously misleading, particularly in incomplete ACTH deficiency states.

Adrenocorticotropic Hormone↗
PubMed1996

Unipolar or bipolar prosthesis for displaced intracapsular hip fracture in octogenarians: a randomised prospective study.

We performed a randomised prospective trial to compare a cemented unipolar prosthesis (Thompson) with a cemented bipolar prosthesis (Monk) in the treatment of displaced intracapsular fractures of the hip in patients over 80 years of age. Patients with a mental test score of less than 5/13 were excluded but the mortality was still about 30% at one year in both groups. We therefore feel that subjective criteria such as the level of pain and the return to the preinjury state are of paramount importance. Two years after operation there was no statistical difference between the rate of complications in the two groups. After adjusting for confounding factors such as differences in the level of function before injury between the groups, the degree of return to the preinjury state was significantly greater (p = 0.04) when using the unipolar prosthesis, which is one-quarter of the price of the bipolar. We cannot therefore justify the use of an expensive bipolar prosthesis in patients over 80 years of age.

Activities of Daily Living↗
PubMed1995

Microdialysis as a tool to measure dietary and regional effects on the complete profile of extracellular amino acids in the hypothalamus of rats.

Regional and dietary-induced changes in hypothalamic extracellular amino acid concentrations were examined. Microdialysis probes were simultaneously implanted in the hypothalamic paraventricular nucleus (PVN) and the lateral hypothalamus (LH) of anesthetized rats and perfused at a rate of 2 microliters/min. Dialysates were collected every 20 min for 1 h prior to gavage of a balanced amino acid mixture (0.85 g patterned after 1 g of chicken egg albumin) and then every 20 min for 3 h after treatment. Tail vein blood samples were also collected. Marked changes in plasma levels of most amino acids were evident immediately following the amino acid gavage. In the PVN, concentrations of isoleucine, leucine, methionine and valine all increased within 40 min, whereas significant decreases in glutamine, histidine and taurine were observed in the LH. In a separate study, PVN extracellular amino acid concentrations were examined in awake, freely-behaving rats following gavage of equicaloric loads of a balanced amino acid mixture, glucose (0.89 g) or water. Dialysate levels of glutamate, isoleucine, leucine, methionine, threonine, tyrosine and valine showed reliable increases after amino acid treatment, although the overall time course of these effects differed somewhat. The amino acid profile of the PVN was, in general, unaffected by glucose administration. These findings suggest that specific brain regions may respond uniquely to amino acid ingestion and further imply that dietary composition may influence the amino acid profiles of the extracellular fluid in brain.

Amino Acids↗
PubMed1995

Sugars, sweetness, and food intake.

Sugars provide a strong, pleasant, sweet taste and at the same time deliver energy when ingested. Their effects on food intake and selection may therefore be a result of both their hedonic and their physiologic features. The theory that appetite signals arising from sugars are different from those arising from other carbohydrates because of sugars' sweetness has led to the hypothesis that sugars are a cause of excessive energy intake and obesity. However, experimental studies provide evidence that the ingestion of > or = 50 g sugar within 20-60 min of a meal results in reduced mealtime food intake, which suggests that appetite regulatory centers respond to sugar's energy content. Epidemiologic studies provide evidence that sugar consumption, as well as carbohydrate consumption, is associated with leanness, not obesity. Thus there is no evidence to support the hypothesis that sugar is unique among carbohydrates as a dietary component affecting food intake.

Adolescent↗
PubMed1995

A subjective health indicator for follow-up. A randomised trial after treatment of displaced intracapsular hip fractures.

We report a randomised prospective trial of the early results of three types of treatment for displaced intracapsular hip fractures. We used a questionnaire sent to patients at about six months (Nottingham Health Profile, NHP) in addition to clinical assessments. There was a 67.4% usable response to the questionnaire, similar to that in other studies using the NHP. There were more responders from younger patients, those walking independently before injury and those with higher mental test scores on admission. In the younger group (65 to 79 years) we found a trend for better scores in most NHP indices after the use of a bipolar prosthesis rather than a unipolar prosthesis or internal fixation, particularly for social function, pain and physical mobility. Postal assessment using the NHP gave a satisfactory response rate even in the elderly, and can provide an extra assessment to complement or replace hospital follow-up in some circumstances.

Activities of Daily Living↗
PubMed1994

Dietary patterns vs. dietary recommendations: identifying the gaps for complex carbohydrate.

Dietary guidelines of the U.S. and Canada recommend that 55% of dietary calories of individuals should come from carbohydrates, especially complex carbohydrates. However, they generally fail to describe how much should come from complex carbohydrates. Undoubtedly, this is because of confusion about the composition of complex carbohydrate foods and incomplete knowledge of the health benefits of all components of grain products. With the intent of shifting dietary food selection to increase carbohydrate consumption above the current 46% of calories, food guides recommend 5 to 12 servings per day from grain products. Current estimated intake for adults is between four to five servings of grain products, of which less than one is from whole grain, in an average 2000-kcal adult diet. To follow the advice of the U.S. Food Guide Pyramid, which suggests half the bread (grains) group should be whole-grain products, adult Americans should increase their intake of whole-grain products four- to fivefold and double their intake of total grain products.

Canada↗
PubMed1994

The effect of age on prevalence of secondary forms of hypertension in 4429 consecutively referred patients.

OBJECTIVES: To investigate the importance of age and other variables on the prevalence of secondary forms of hypertension in a hypertension referral center. DESIGN: Over the past 18 years 4429 patients have been referred by their physicians for a 1-day blood pressure study to investigate secondary causes of hypertension. METHODS: The 1-day blood pressure study included a history and physical examination by a physician, and measurements of serum sodium, potassium, creatinine, thyroxine, thyroid stimulating hormone, stimulated plasma renin activity, blood pressure response to the angiotensin II analogue saralasin, recumbent and upright plasma catecholamines, and plasma cortisol and aldosterone after infusion of 2 liters 0.9% saline over 3-4 h. RESULTS: The prevalence of secondary forms of hypertension was 10.2%, including renovascular hypertension (3.1%), primary aldosteronism (1.4%), Cushing's syndrome (0.5%), pheochromocytoma (0.3%), primary hypothyroidism (3.0%) and a serum creatinine > 2.0 mg/dl (1.8%). There was a very significantly increased prevalence with age of secondary forms of hypertension associated with renovascular hypertension, primary hypothyroidism and renal insufficiency. The concomitant presence of atherosclerosis significantly increased the prevalence of renovascular hypertension (9.5%) and renal insufficiency (8.0%). CONCLUSIONS: Increasing age and coexisting atherosclerosis have significant effects on the prevalence of secondary forms of hypertension.

Adrenal Gland Neoplasms↗