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Biomedical subjects

P Boyle

Publications and source records attributed to P Boyle.

At least 415 records · Page 23Linked to original sources

Metolazone and bendroflumethiazide in hypertension: physiologic and metabolic observations.

A double-blind crossover comparison was made in 18 nonedematous hypertensive subjects with glomerular filtration rates exceeding 70 ml/min/1.73 m2 of the effects of 5 mg metolazone and 5 mg bendroflumethiazide on blood pressure and metabolic parameters. After a 4-wk run-in placebo period, patients received either metolazone or bendroflumethiazide for 6 wk in a crossover fashion with an intervening washout period of 4 wk. Metolazone induced a more sustained and greater blood pressure response than bendroflumethiazide. Changes in plasma potassium, urate, bicarbonate, renin, and angiotensin II occurred during treatment with both metolazone and bendroflumethiazide; the only significant difference, however, was in changes in plasma bicarbonate. Total body potassium (TBK), measured by whole-body monitor, did not fall outside the normal range with either metolazone or bendroflumethiazide, although metolazone induced a greater reduction in TBK (6.2 gm, 5.5% of TBK) than bendroflumethiazide (1.2 gm, 1.1% of TBK, p < 0.05). Our results suggest that metolazone is a more effective antihypertensive and induces similar but greater metabolic changes than bendroflumethiazide. The results of our comparison suggest that although changes in plasma potassium and TBK are minor, they are greater with metolazone, and potassium supplements may not be necessary in nonedematous hypertensive patients with normal renal function.

Adolescent↗

Intelligence and phenylketonuria: effects of diet termination.

Trends in intellectual functioning before and after diet termination were examined in 30 children with PKU treated before 6 weeks of age and on a liberal diet for a mean of three years since the mean age of 59 months. Comparisons of trends in pre- and posttermination IQ scores with the linear spline technique revealed no significant differences. Comparisons of pretermination IQ scores with posttermination scores and scores from the most recent evaluation also yielded no significant differences. These data fail to support a relationship between termination of diet and impairment of intellectual functioning, at least during this period of observation.

Adolescent↗

The effects of steroids and glucagon on the morphological changes in the duct-ligated pancreas of the rat.

Ligation of the rat pancreatic duct produced degeneration of the exocrine acinar tissue, inflammatory cell infiltration and fibrosis. The injection of methyl prednisolone for 5 days following duct ligation produced a marked reduction in the inflammatory-cell infiltrate whereas the administration of glucagon or a combination of glucagon and methyl prednisolone produced only a mild reduction in acinar degeneration. Administration of the drugs for 5 days after duct ligation and examination of the pancreas after 3 months showed no differences in the degree of cellular infiltration and acinar degeneration between controls and those that had received glucagon or glucagon and methyl prednisolone. However, those rats that had received only methyl prednisolone showed fibrosis, a minimal inflammatory-cell infiltrate and a considerable reduction in exocrine tissue. Mild degranulation of the islets of Langerhans was observed in those rats that received methyl prednisolone, alone or in combination with glucagon, and at 3 months the islets appeared normal. The implications for pancreatic transplantation are discussed.

Animals↗

Perceptual-motor functioning in children with phenylketonuria.

Children with treated phenylketonuria (PKU) have been described as being at high risk for perceptual-motor dysfunction. In this study, the Wechsler Intelligence Scale for Children (WISC) and the Bender Gestalt test were administered to 19 school age children with treated PKU and of average intelligence who have been off diet from five months to six years four months. Perceptual-motor performance was evaluated, and school functioning was rated by classroom teachers. Substantial impairment of perceptual-motor functioning as measured by the Bender Gestalt test and lower WISC performance IQs than verbal IQs were observed in children of average intelligence. Quality of dietary control was found to be associated with performance on the Bender Gestalt test. These findings suggest the possibility of a specific deficit that could seriously interfere with academic progress, but which is not signalled by obvious impairment of overall intellectual functioning.

Achievement↗

The interrelation of personality and postoperative factors.

A composite statistical analysis was made of the results from four trials comprising patients undergoing upper abdominal operations. It revealed a marked correlation between the neuroticism score as measured by a personality inventory before operation and the percentage vital capacity impairment found after operation. Neuroticism correlated also with pain as measured by a visual analogue scale. The vital capacity impairment and subjective pain readings were interrelated and both neuroticism and vital capacity impairment were related to the chest complication rate. Personality assessment before operation can identify one group of patients who will have marked pain and limitation of vital capacity after operation.

Abdomen↗

The Elag-Koln automatic blood pressure recorder. A clinical appraisal.

The performance of an Elag-Koln semiautomatic blood pressure recorder was compared with the London School of Hygiene mercury sphygmomanometer in 24 subjects providing a wide range of blood pressure measurements. Readings with the two instruments correlated highly (for systole, r=0-99; for diastole phase 4, r=0-97; for diastole phase 5,r=0-98), and the slopes of the regressions did not differ significantly from unity. Elag-Koln measurements were higher for systole (mean difference 3-7 mmHg,P less than 0-001) and diastole phase 5 (mean difference 7-4 mmHg,P less than 0-001), but agreed closely with diastole phase 4 readings with the London School of Hygiene instrument. The Elag-Koln recorder tested was compact, easy to use, and had acceptable accuracy. This type of instrument deserves further testing to examine its suitability for general use.

Blood Pressure Determination↗

Factors influencing serum potassium in treated hypertension.

A retrospective survey of serum potassium measurements in a blood pressure clinic provided evidence that potassium supplements averaging 24 mmol daily were effective in elevating serum potassium concentration and reducing the incidence of hypokalaemia in diuretic-treated hypertensives. In patients treated with bendrofluazide the serum potassium concentration was related to the dose of diuretic, but not to age, sex, body weight, supine blood pressure or serum creatinine. There was no evidence that drugs other than diuretics or potassium (including beta-adrenergic blockers) had a clinically significant influence on serum potassium. The major part of the variation in serum potassium between patients could not be explained by the variables examined.

Adult↗

Age, period and cohort models: the use of individual records.

Problems with the interpretation of age-period-cohort models are discussed. If individual records are available for cancer incidence in Scotland, then a solution is obtainable. An example using incidence data for cancers of the lung and larynx in Scotland is presented to illustrate the models.

Age Factors↗

Reported family aggregation of pancreatic cancer within a population-based case-control study in the Francophone community in Montreal, Canada.

As part of the SEARCH Collaborating Study Group of the International Agency for Research on Cancer (IARC), a population-based case-control study of cancer of the pancreas was conducted in Montreal, interviewing 179 patients and 179 controls matched for age, sex, and language (French) and selected by a modified random-digit dialing method. Results showed a positive and strong association between cigaret smoking and pancreatic cancer. Total fat, particularly saturated fat, and cholesterol consumption and excess energy derived from fat were associated with positive risk; dietary fiber intake, retinol equivalent, beta-carotene, vitamin C, and calcium showed inverse association with risk. History of such medical conditions as constipation, gallbladder problems, and diabetes was also found to be associated with risk. More important, 7.8% of the pancreatic cancer patients reported a positive family history of the same disease, as compared with 0.6% among controls, a 13-fold difference between cases and controls. Within the original case-control study a further study of patients with instances of familial pancreatic cancer was conducted, based on 14 cases and 56 matched controls. The results support the finding of the main study, and there were no apparent differences in environmental-risk-factor profile in familial and nonfamilial cases. This unusual aggregation of familial pancreatic cancer among French Canadians cannot be explained by environmental factors alone. Some familial predisposition (hereditary factors) may play an important role in the etiology of this cancer, at least in this study region. The findings suggest the potential importance of conducting genetic studies of pancreatic cancer.

Canada↗

A case-control study of lung cancer among Czech women.

Few data are available to explain the continuing increase in lung cancer mortality among Czech women. The study was designed to examine the role of active smoking and other known or suspected factors. Data collected by personal interviews during the 15 months of a hospital-based case control study are reported. A total of 140 microscopically confirmed cases and 280 frequency-matched controls were analysed using multiple logistic regression. Cigarette smoking was the most important factor associated with excess risk for lung cancer among women. Significantly increased risk was found both among current smokers (OR=11.20, 95% CI 5.9-21.2), and ex-smokers (OR=10.02, 95% CI 5.5-18.4). Positive dose-response gradients (P<0.001) were observed between lung cancer risk and the daily number of cigarettes, duration of smoking, number of pack-years, inhaling, and grade of nicotine dependence assessed by the Fagerström test (Heatherton TF, Kozlowski LT, Frecker RC, Fagerström KO. Br J Addict 1991;86:1119-1470; Pomerleau OF. In: Bolliger CT, Fagerström KO, editors. The Tobacco Epidemic. Basle: Karger, 1997: 122-131). Exposure to environmental smoke was associated with elevated lung cancer risk (OR=3.58, for lifetime non-smokers exposed both in childhood and in adult age). Physical exercise and body mass index were inversely associated with lung cancer risk. For the category of physical exercise of more than 5 h per week, the odds ratio was 0.38, compared to subjects admitting no physical exercise. For body mass index, the odds ratio for the highest (compared to the lowest) quartile was 0.50. Chronic cough and phlegm (at least 3 months per year) were associated with excess risk (OR=6.07) only if their duration was less than 2 years before diagnosis of lung cancer, and, therefore, they were suspected of being more likely early symptoms of preclinical lung cancer rather than its cause. Our results support the statement that cigarette smoking is by far the most important cause of the on-going epidemic of lung cancer among Czech women, and are consistent with the concept of a balance between risk and protective factors whose eventual maintenance or alteration determine the development of disease (as suggested by Rylander R, Axelsson G, Andersson L, Liljequist T, Bergman B. Lung Cancer 1996;14(Suppl 1): S75-S83). Concerted control of smoking appears to be an urgent priority in lung cancer prevention among women, including specific approaches targeted on the female population.

Adult↗

Audiotape slide programmes: comparison of synchronised and manual use.

No difference in teaching effectiveness was found between the use of a series of audiotape slide programmes on clinical physics and measurement with synchronised and manual slide change. Over 93% of the lecture points could be immediately recalled in both instances and significantly different learning abilities among the students were detected. The trial also identified programmes with lower answer scores for possible upgrading. Comparison with a previous trial demonstrated the value of the revision and upgrading of materials. Anaesthetists found the teaching by the tape slide technique, in the format used, helpful and very acceptable. The advantages and disadvantages of the use of audiotape slide programmes with synchronised and manual slide change apparatus have been discussed.

Anesthesiology↗

The relationship between oral contraceptive use, cancer and vascular disease.

An overview of the available epidemiological evidence on the connection between oral contraceptives and cancer or vascular disease is presented, including the observation that epidemiological studies have produced important indications for changing both the composition and prescription patterns of oral contraceptives to avoid a large proportion of vascular side effects. Further, the evidence is remarkably clear and consistent in relation to the elevated risks of cervical neoplasms and, although based on a limited number of small studies, of primary liver cancer; protection against endometrial and ovarian cancers up to middle age; and the absence of association with malignant melanoma. There are still uncertainties regarding breast cancer, mainly related to the role of time factors, and the potential persisting risk related to long term use at younger age: published studies, in fact, show elevated risks for long term use in women below age 35 or perhaps up to age 45, but no evidence of association in middle age. Since breast cancer and ovarian cancer account for most of the mortality burden in women up to age 50 or 55 in developed countries, a clarification of the risk relationship for these 2 neoplasms will determine most of the quantitative evaluation on positive or adverse effects of oral contraceptives. The impact of other neoplasms and of cardiovascular disease, on the basis of current oral contraceptive composition, is comparatively limited, if not negligible.

Contraceptives, Oral↗

Epidemiology of gallbladder cancer.

Gallbladder cancer, although rare in most Caucasian populations, is among the most frequently observed cancers in native populations of North and South America, and in the Maori population of New Zealand. In all populations, there is a strong correlation between gallstones and gallbladder cancer: the risk of gallbladder cancer is approximately 4-5 times higher in patients with gallstones, than in patients without gallstones. In those populations where the onset of gallstone disease occurs in the first few decades, the risk is much higher. Obesity, which is also a risk factor for gallstones, increases the risk of gallbladder cancer, as does the consumption of diets high in fats and calories. Other risk factors, such as increased parity, also increase the frequency of gallbladder cancer, most probably explained by the association between gallstones and parity. Prophylactic cholecystectomy for asymptomatic gallstones cannot be justified for the control of gallbladder cancer, but the increasing frequency of this procedure in many countries, secondary to the widespread use of laparoscopic surgical techniques, will clearly lower the incidence and mortality rates for this lethal disease.

Adult↗