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Biomedical subjects

P Elliott

Publications and source records attributed to P Elliott.

At least 109 records · Page 6Linked to original sources
PubMed1996

Inverse relation of dietary protein markers with blood pressure. Findings for 10,020 men and women in the INTERSALT Study. INTERSALT Cooperative Research Group. INTERnational study of SALT and blood pressure.

BACKGROUND: The purpose of this study was to assess relations to blood pressure (BP) in individuals of markers of dietary protein in their 24-hour urine collections. METHODS AND RESULTS: INTERSALT (INTERnational study of SALT and blood pressure) was a cross-sectional study of 10020 men and women aged 20 to 59 years in 52 population-based samples in 32 countries worldwide, with quality-controlled standardized procedures and assessment of multiple possible confounders. Three measurements of dietary protein in 24-hour urine of each individual participant were studied: total nitrogen and urea as indexes of total protein intake, and sulfate as an index of sulfur-containing dietary amino acids. Repeat examination was performed in a random 8% of participants to assess reliability and to correct for regression-dilution bias. Significant independent inverse relationships were found between BP (systolic and diastolic) and both 24-hour urinary total nitrogen and urea nitrogen, with adjustment for age, sex, alcohol intake, body mass, and 24-hour urinary sodium, potassium, calcium, and magnesium. With adjustment for regression-dilution bias, it was estimated that systolic and diastolic BP were on average 3.0 and 2.5 mm Hg lower, respectively, for persons with dietary total protein intake 30% above the overall mean than for those whose dietary protein intake was 30% below the overall mean (12.94 versus 6.96 g/d urinary total nitrogen, equivalent to 81 versus 44 g/d dietary protein, respectively). For the association of these markers with diastolic BP, results were similar for younger (20- to 39-year-old) and older (40- to 59-year-old) persons and for women and men. For their relation to systolic BP, regression coefficients were larger both for those aged 40 to 59 years than for those aged 20 to 39 years and for women than for men. Nonsignificant inverse relations were recorded for urinary sulfate and BP. CONCLUSIONS: These INTERSALT findings lend support to the hypothesis that higher dietary protein intake has favorable influences on BP.

Adult↗
PubMed1996

Intersalt revisited: further analyses of 24 hour sodium excretion and blood pressure within and across populations. Intersalt Cooperative Research Group.

OBJECTIVES: To assess further the relation in Intersalt of 24 hour urinary sodium to blood pressure of individuals and populations, and the difference in blood pressure from young adulthood into middle age. DESIGN: Standardised cross sectional study within and across populations. SETTING: 52 population samples in 32 countries. SUBJECTS: 10,074 men and women aged 20-59. MAIN OUTCOME MEASURES: Association of sodium and blood pressure from within population and cross population multiple linear regression analyses with multivariate correction for regression dilution bias. Relation of sample median daily urinary sodium excretion to difference in blood pressure with age. RESULTS: In within population analyses (n = 10,074), individual 24 hour urinary sodium excretion higher by 100 mmol (for example, 170 v 70 mmol) was associated with systolic/diastolic blood pressure higher on average by 3/0 to 6/3 mm Hg (with and without body mass in analyses). Associations were larger at ages 40-59. In cross population analyses (n = 52), sample median 24 hour sodium excretion higher by 100 mmol was associated with median systolic/diastolic pressure higher on average by 5-7/2-4 mm Hg, and estimated mean difference in systolic/diastolic pressure at age 55 compared with age 25 greater by 10-11/6 mm Hg. CONCLUSIONS: The strong, positive association of urinary sodium with systolic pressure of individuals concurs with Intersalt cross population findings and results of other studies. Higher urinary sodium is also associated with substantially greater differences in blood pressure in middle age compared with young adulthood. These results support recommendations for reduction of high salt intake in populations for prevention and control of adverse blood pressure levels.

Adult↗
PubMed1996

Dietary calcium and blood pressure: a meta-analysis of randomized clinical trials.

PURPOSE: To assess the effect of dietary calcium supplementation on blood pressure. DATA SOURCES: Published reports of trials studying the effect of dietary calcium supplementation on blood pressure were identified by a search of previous reviews, a MEDLINE search, a manual review of journal articles, and a review of abstracts from scientific meetings. STUDY SELECTION: Randomized clinical trials in which dietary calcium intake varied by intervention group were selected. Multifactorial trials were not included. DATA SYNTHESIS: Data from 28 active treatment arms or strata from 22 randomized clinical trials were pooled using a weighted average method, with weights proportional to the inverse of the variance of the treatment effect. The total sample comprised 1231 persons. Because trials of both normotensive and hypertensive persons were included, subgroup analyses could be done. Pooled estimates of the effect of calcium supplementation on blood pressure were -0.18 mm Hg for diastolic blood pressure (95% CI, -0.75 to 0.40 mm Hg) and -0.89 mm Hg for systolic blood pressure (CI, -1.74 to -0.05 mm Hg). Pooled estimates for systolic blood pressure were -0.53 mm Hg (CI, -1.56 to 0.49 mm Hg) for trials of normotensive persons and -1.68 mm Hg (CI, -3.18 to -0.18 mm Hg) for trials of hypertensive persons. Diastolic blood pressure was not significantly affected in either subgroup. CONCLUSION: The pooled estimate shows a statistically significant decrease of systolic blood pressure with calcium supplementation, both for hypertensive persons and for the overall sample. However, the effect is too small to support the use of calcium supplementation for preventing or treating hypertension.

Adult↗
PubMed1996

Permeability of the blood brain barrier by the bradykinin agonist, RMP-7: evidence for a sensitive, auto-regulated, receptor-mediated system.

The novel bradykinin (BK) analog, RMP-7, was characterized in a series of in vitro tests to establish its selectivity as a B2 agonist. It was then used to study bradykinin's role in permeabilizing the blood brain barrier (BBB) and blood brain-tumor barrier (BTB), using an RG2 rat glioma model. These studies demonstrated that: (1) B2 receptor stimulation permeabilizes both the BBB and BTB in a dose-related fashion with greater effects observed in brain tumor-associated tissue, (2) the increased permeability is sensitive, rapid and transient, and (3) tachyphylaxis occurs with continuous agonist administration, suggesting autoregulation of the system's effects. These data therefore support the existence of a sophisticated, responsive and tightly regulated BK system whose activity modulates the permeability of the BBB.

Animals↗
PubMed1996

Cancer incidence near municipal solid waste incinerators in Great Britain.

By use of the postcoded database held by the Small Area Health Statistic Unit, cancer incidence of over 14 million people living near 72 municipal solid waste incinerators in Great Britain was examined from 1974-86 (England), 1974-84 (Wales) and 1975-87 (Scotland). Numbers of observed cases were compared with expected numbers calculated from national rates (regionally adjusted) after stratification by a deprivation index based on 1981 census small area statistics. Observed-expected ratios were tested for decline in risk with distance up to 7.5 km. The study was conducted in two stages: the first involved a stratified random sample of 20 incinerators; the second the remaining 52 incinerators. Over the two stages of the study was a statistically significant (P<0.05) decline in risk with distance from incinerators for all cancers combined, stomach, colorectal, liver and lung cancer. Among these cancers in the second stage, the excess from 0 to 1 km ranged from 37% for liver cancer (0.95) excess cases 10(-5) per year to 5% for colorectal cancer. There was evidence of residual confounding near the incinerators, which seems to be a likely explanation of the finding for all cancers, stomach and lung, and also to explain at least part of the excess of liver cancer. For this reason and because of a substantial level of misdiagnosis (mainly secondary tumours) found among registrations and death certificates for liver cancer, further investigation, including histological review of the cases, is to be done to help determine whether or not there is an increase in primary liver cancer in the vicinity of incinerators.

Incidence↗
PubMed1996

Dietary salt, nitrate and stomach cancer mortality in 24 countries. European Cancer Prevention (ECP) and the INTERSALT Cooperative Research Group.

BACKGROUND: High salt and nitrate intake are considered as risk factors for stomach cancer, but little is known about possible interactions. This ecological study examines the respective importance of both factors for stomach cancer mortality at the population level using data obtained under standardized conditions and with biochemical analyses performed in the same laboratories. METHODS: Randomly selected 24-hour urine samples from 39 populations, sampled from 24 countries (N = 5756 people for sodium, 3303 for nitrate) were obtained from the INTERSALT study. Median sodium and nitrate levels were age- and sex-standardized between ages 20-49 years and averaged per country. Ecological correlation-regression analyses were done in relation to national stomach cancer mortality rates. RESULTS: The Pearson correlation of stomach cancer mortality with sodium for the 24 countries was: 0.70 in men and 0.74 in women (both P < 0.001) and with nitrate: 0.63 (P = 0.001) in men and (P < 0.005) in women. In multiple regression of stomach cancer mortality, using sodium and nitrate as independent variables the adjusted R2 was 0.61 in men and 0.54 in women (both P < 0.001). Addition of the interaction term (sodium x nitrate) to the previous model increased the adjusted R2 to 0.77 in men, and to 0.63 in women. The analysis of this model showed that the importance of nitrate as risk factor for stomach cancer mortality increased markedly with higher sodium levels. However, the relationship of stomach cancer mortality with sodium was always stronger than with nitrate. CONCLUSIONS: Salt intake, measured as 24-hour urine sodium excretion, is likely the rate-limiting factor of stomach cancer mortality at the population level.

Adult↗
PubMed1996

Twenty-four hour urinary nitrate excretion in 48 populations from 30 countries: an ECP-INTERSALT collaborative study.

BACKGROUND: There is considerable interest in the possible role of nitrate in gastric carcinogenesis, but little information on nitrate intake around the world. This is the first study to give comprehensive standardised data on nitrate excretion as a marker of intake, using 48 worldwide population samples. METHODS: Urinary nitrate excretion has been shown to be a valid measure of nitrate intake in people under 50. This report presents data on 24-hour urinary nitrate excretion from urine collections obtained in the INTERSALT study, based on random samples of men and women aged 20-49 from each of 48 population samples in 30 countries. RESULTS: There was large variation in urinary nitrate excretion both within and between samples; within-sample (individual) distributions tended to be skewed towards higher values. Median values of the samples ranged from 0.42 mmol/day (Labrador, Canada) to 3.52 (Beijing, People's Republic of China) in men and 0.44 mmol/day (Colombia) to 3.44 (Beijing) in women. Overall, median values were higher in men than women by 11% on average (higher in men in 37 of 48 population samples). Comparison by geographical region of median values for men and women combined showed relatively low values in the samples in North America and Northern Europe (range 0.46-0.88 mmol/day), slightly higher values in Western Europe and Africa (0.68-1.11), and intermediate to high values in Southern Europe, Eastern and Central Europe and India (0.86-2.47). The highest median values were found in the Far Eastern samples (up to 3.48). Median values in the Central and South American samples ranged from 0.48 mmol/day (Colombia) to 1.37 (Xingu Indians of Brazil, and Argentina). CONCLUSIONS: For the first time, these data give standardized information on urinary nitrate excretion from different geographical regions of the world, and provide a basis for the further exploration of the role of nitrate in the aetiology of disease in human populations.

Adult↗
PubMed1996

Eosinophil infiltration into human skin is antigen-dependent in the late-phase reaction.

Eosinophils play a critical role in late-phase reaction allergic inflammatory responses, although the factors responsible for selective tissue eosinophilia are currently ill-defined. To determine whether recruitment of eosinophils is allergen-specific, or a feature of inflammation in allergic individuals, we have examined cutaneous cell infiltrates and endothelial cell adhesion molecule expression in atopic subjects 6 h (n = 8) and 24 h (n = 7) following ultraviolet-B (UVB) irradiation, or intradermal injection of late-phase reaction allergens or diluent control, using standard immunohistochemical techniques. The numbers of eosinophils were increased significantly, when compared to controls, at both 6 h (P < 0.01) and 24 h (P < 0.05), following intradermal allergen challenge, whereas no significant increase in eosinophils was observed following UVB irradiation. UVB and allergen both induced significant increases in neutrophils, monocytes and T cells at 24 h compared to control sites. An increased expression of endothelial cell adhesion molecules, E-selectin and intercellular adhesion molecule-1 (ICAM-1), was observed in both models of inflammation. Vascular cell adhesion molecule-1 (VCAM-1) was induced weakly on some biopsies following allergen, and not at all following UVB. These data indicate that eosinophil infiltration in susceptible individuals is a specific property of allergen. Although this study would support the postulated role of VCAM-1 in selective eosinophil recruitment, given its variable and weak expression, additional factors are likely to be involved.

Allergens↗
PubMed1995

Epidemiologic association between dietary calcium intake and blood pressure: a meta-analysis of published data.

The objectives of the study were to assess whether the epidemiologic data support a relation between dietary calcium intake and blood pressure, to obtain a quantitative estimate of the difference in blood pressure for a given difference in dietary calcium intake, and to assess the public health implications. A meta-analysis of published data (January 1983 to November 1993) that investigated the association between dietary calcium intake and blood pressure in different populations around the world was performed. Of 63 population studies identified, 23 were suitable for a quantitative overview (total n = 38,950). Unadjusted regression coefficients (95% confidence intervals) were obtained. Pooled unadjusted regression coefficients (95% confidence intervals) were then computed weighting each individual study by the inverse of its variance. Tests of heterogeneity and sensitivity analysis were carried out, and the possibility of publication bias was assessed. The regression coefficients ranged between -9.40 and 1.63 mmHg/100 mg calcium for systolic blood pressure and between -4.90 and 0.47 for diastolic blood pressure. In men (11 studies, n = 7,271), the pooled regression coefficients were -0.010 and -0.009 mmHg/100 mg calcium for systolic and diastolic pressures, respectively (p < 0.001 and p < 0.05). In women (six studies, n = 8,507), they were -0.15 and -0.057 mmHg/100 mg calcium (p < 0.001 and p < 0.02), and in men and women combined (six studies, n = 23,172 for systolic pressure and four studies, n = 3,215 for diastolic pressure) they were -0.061 and -0.061 mmHg/100 mg calcium (p < 0.001 and p < 0.05). In those studies that used the 24-hour recall method, the pooled regression coefficients were -0.06 and -0.09 mmHg/100 mg calcium (p < 0.005 and p = 0.07), whereas in those that used the food frequency questionnaire, they were -0.15 and -0.05 mmhg/100 mg calcium (p < 0.001 and p < 0.03). These data are consistent with an inverse association between dietary calcium intake and blood pressure. However, the size of the estimate, the observed heterogeneity among studies, and the possibility of confounding and publication bias indicate that an increase in calcium intake above the Recommended Dietary Allowance is not recommended at population level for the prevention and treatment of high blood pressure.

Adult↗
PubMed1995

Lymph node metastases, cell type, age, HPV status and type, neoadjuvant chemotherapy and treatment failures in cervical cancer.

Conflicting evidence on the prognostic influence of some of the clinical and histopathological variables in cervical cancer of the HPV status and type and chemotherapeutic response prompted a number of reviews from nearly 40 years experience in a tertiary referral centre. The collation and analyses of these data with those from recent literature allow some proposals to be made. The disease is more prevalent in the young women in whom, in many centers, the mortality is also higher; the latter may be related to the reported increase in both small cell types and adeno and adenosquamous carcinoma--a finding more marked in the young. Lymph node metastases, related to increasing grade, size, stage and lymph space invasion, are unequivocally associated with a worse prognosis. Resolution of the exact nature of the intimate association of this disease with the human papilloma virus remains to be resolved as does the influence on prognosis of the tumor HPV status and that of the different oncogenic types. Reports on the efficiency of neoadjuvant platinum based combination chemotherapy are generally promising but vary considerably depending on the regimen used. Its value will not be determined without properly conducted large randomized studies.

Age Factors↗
PubMed1995

Different trends in serum cholesterol levels among rural and urban populations aged 40-59 in Japan from 1960 to 1990.

In Japan, coronary heart disease mortality is low and has been declining since 1970, despite recent increases in serum cholesterol levels which have been reported in nationwide surveys. Longitudinal and cross-sectional surveys of serum cholesterol levels in rural and urban populations from 1960 to 1990 were reviewed. In the surveys in the 1960s, serum cholesterol levels in urban populations were higher than those in rural populations. An increase in serum cholesterol levels for men and women was observed in all longitudinal studies among rural populations; mean increases in serum cholesterol levels per year were 0.034 mmol/l (p < 0.001) and 0.033 mmol/l (p < 0.001), respectively. These trends were still observed after combining the data from the longitudinal and cross-sectional studies in both men and women (0.027 and 0.028 mmol/l per year, respectively), while there was no significant increase among urban populations. The results of National Nutrition Surveys are consistent with these findings and show that meat consumption per day per capita increased from 23.9 to 66.2 g in rural populations and 51.2 to 77.6 g in urban populations in the 1966 and 1990 surveys. It is suggested that different trends in coronary heart disease mortality should also be apparent in rural and urban populations over this period.

Adult↗
PubMed1995

Comparison of the haemodynamic effects of mivacurium and atracurium during fentanyl anaesthesia.

We have measured the haemodynamic effects of mivacurium 0.15 and 0.2 mg kg-1, and atracurium 0.5 mg kg-1 administered over 10-15 s in patients undergoing coronary artery bypass surgery under fentanyl anaesthesia. There were no significant haemodynamic changes in the atracurium group, other than a transient decrease in pulmonary arterial wedge pressure. Changes in heart rate were small in all three groups. Mivacurium 0.15 mg kg-1 produced changes of only small magnitude (12% decrease in mean arterial pressure and 16% decrease in systemic vascular resistance index) however, mivacurium 0.2 mg kg-1 produced a 25% reduction in mean arterial pressure, a 14% increase in cardiac index and a 35% decrease in systemic vascular resistance index. Erythema developed in two, three and seven patients after atracurium, mivacurium 0.15 mg kg-1 and mivacurium 0.2 mg kg-1, respectively. One patient exhibited a 54% decrease in mean arterial pressure, generalized erythema and bronchospasm after mivacurium 0.2 mg kg-1. The haemodynamic changes with mivacurium suggested histamine release.

Atracurium↗
PubMed1995

Neoplastic meningitis with normal neurological findings. Magnetic resonance imaging results.

Neoplastic meningitis, an unusual complication of systemic cancer, is becoming more common as cancer patients live longer. Although leptomeningeal metastases from solid tumors are usually associated with multifocal neurological signs, the authors report on 4 patients who presented with normal findings on neurological examination. One man had severe headache and complex partial seizures. Magnetic resonance imaging (MRI) of the brain revealed gadolinium enhancement of multiple cranial nerves. Cerebrospinal fluid (CSF) cytology was positive for melanoma. One woman presented with severe migratory retroorbital headaches. MRIs of the brain with and without gadolinium appeared normal. CSF cytology was positive for pulmonary adenocarcinoma. One man presented with morning headache, and a woman presented with back pain. Both had CSF cytologies positive for lymphoma. Neoplastic meningitis can occur without abnormalities on neurological or MRI examinations. Lumbar punctures should be performed on cancer patients with severe, unusual, or prolonged headaches.

Adenocarcinoma↗
PubMed1995

Disease risk near point sources: statistical issues for analyses using individual or spatially aggregated data.

STUDY OBJECTIVE: To examine the statistical issues involved in the analysis of disease risk near point sources of environmental pollution, where data are held at both the individual and group (areal) level. To explore these issues with reference to possible socioeconomic confounding. DESIGN: Statistical review. SETTING: Point sources of environmental pollution. MAIN RESULTS: Except in very specific circumstances unlikely to hold in practice, aggregation of data to the areal level will lead to bias in the estimation of disease risk. CONCLUSIONS: There is no easy solution to the analysis of spatial data when some covariates (for example, age and sex of cases) are known at individual level, whereas others (for example, populations, age-sex distributions, small area deprivation indices) are known only at the areal (ecological) level. The underlying assumptions inherent in the analysis of these data need to be explicitly recognised in order to understand better the limitations of the available methodology as well as to inform interpretation of results. Ideally, the data should be kept as disaggregated as possible, to maximise the information available and minimise potential for bias.

Bias↗
PubMed1995

Smoking behaviour can be predicted by neighbourhood deprivation measures.

STUDY OBJECTIVE: To assess whether small area measures of socioeconomic deprivation predict variation in individual smoking behaviour. To examine the adequacy of an individual level statistical model for the analysis of data on groups of individuals who live in the same geographical area. DESIGN: Individual level and two level logistic regression analysis of data on individual smoking from a regional health survey, and neighbourhood deprivation scores for 1991 census wards calculated from 1991 census data. SETTING: The North West Thames Regional Health Authority area. PARTICIPANTS: Random sample of 8,251 adults in North West Thames Regions. MAIN RESULTS: There was a highly significant association between being a smoker and the neighbourhood deprivation score of the area of residence. With the two level model, after allowing for age and sex, the estimated odds ratio of being a smoker for an individual in the highest quintile of deprivation compared with someone in the lowest quintile was 1.52 (95% confidence interval 1.33, 1.74). Results obtained using the individual level model were similar. Variation between wards accounted for around 6% of the total variation in smoking behaviour after neighbourhood deprivation of the ward had been taken into account. Deprivation of the area of residence remained a significant predictor of smoking status even after the socioeconomic group of the individual has been taken into account. CONCLUSIONS: Neighbourhood deprivation of the area of residence is a predictor of smoking status of individuals. In this example the two level model was reasonably well approximated by the individual level model.

Adult↗