Biomedical subjects

P Elliott

Publications and source records attributed to P Elliott.

At least 163 records · Page 9Linked to original sources

PubMed1992

Higher blood pressure in adults with less education. Some explanations from INTERSALT.

An inverse association between social class and disease has frequently been reported; education, an indicator of social class, was negatively related to blood pressure in several studies. Reasons are not clear. INTERSALT, an international study on electrolytes and blood pressure, obtained data on years of education for 10,079 adults in 52 centers in 32 countries. Data presented here are for 47 centers, omitting five where the population in the sample had no education or no differences in educational level. Regression coefficients were calculated for the education-blood pressure association in each center. An inverse association was found for men in 28 centers and for women in 38. Center coefficients were combined to give a studywide estimate of that association. When adjusted only for age, systolic pressure in men was 1.3 mm Hg higher for 10 fewer years of education (p less than 0.05) and for women 4.5 mm Hg higher (p less than 0.001). However, when adjusted also for five lifestyle factors (24-hour sodium and potassium excretion, body mass index, alcohol intake, and smoking), these estimates were reduced by about one half, and the inverse association was no longer significant for men. Similar findings were obtained for diastolic pressure. Those with less education had on average higher sodium excretion, lower potassium excretion, greater body mass, and higher alcohol intake, all factors tending to increase blood pressure. Improvement of these factors, which help explain the differences in blood pressure related to years of education, has the potential to reduce the blood pressure disadvantage associated with lower socioeconomic status.

Adult↗

PubMed1992

Bilateral fibroepithelial polypi of labium minus with atypical stromal cells.

A case of fibroepithelial polyp of labium minus with stromal atypia is described. This unusual tumor has only recently been reported occurring in the vulva. The tumor measured 12 cm in maximal diameter and its cut surface was soft and myxoid. After fixation the tumor was considerably smaller in size. The light microscopic findings were of a loose acellular myxoid stroma, traversed by thin walled dilated vascular spaces and covered by stratified squamous epithelium and with sparse fibroblast-like cells dispersed throughout. This case is unusual as fibroepithelial polyps with stromal atypia are an uncommon tumor of the vulva, are rarely bilateral and in this site no lesion previously has exceeded 4.0 cm in diameter.

Adult↗

PubMed1991

Percutaneous urinary diversion in gynecologic oncology.

During the 10-year period after 1979, percutaneous urinary diversion (PCUD) was performed on 35 patients whose mean age was 53.5 years (30-80 years). Twenty-one patients (60%) had Stage IIB-IV cervical cancer, 11 (31%) Stage IB-IIA cervical cancer, 2 (6%) Stage IB-II endometrial cancer, and 1 (3%) Stage IB vaginal cancer. All had radiological evidence of ureteric obstruction and 8 patients also had urinary tract fistulae. Serum creatinine levels were elevated in 24. Following diversion there was a significant fall in mean pretreatment creatinine levels from 482 mumol/liter (range, 70-1703 mumol/liter) to 131 mumol/liter (range, 60-290 mumol/liter; P less than 0.0001); those patients with normal creatinine levels prior to diversion also had a reduction in their levels. A significant fall in mean serum urea levels from 22.0 mmol/liter pre- to 11.9 mmol/liter post-PCUD (P less than 0.001) was also noted. Minor complications occurred and included hemorrhage, replacement/reinsertion, infection, and blockage. Median survival of the 35 patients after PCUD was 6 months (mean, 16.5 months). For the 11 with normal pretreatment renal function median survival was 16 months (mean, 41 months) compared to 2.5 months (mean, 5.1 months) for those with elevated pretreatment serum creatinine levels. Median survival with untreated malignancy was 7 months (mean, 19.6 months) and 6 months (mean, 12.3 months) in patients with previously treated cancer. PCUD is indicated in previously untreated patients with gynecologic cancer so that primary therapy can be instituted. The role of urinary diversion in patients with previously treated cancer must be individualized. Palliative diversion is appropriate in selected patients where additional therapy is expected to prolong life, where symptom control is needed, or to allow the patient to return home for a significant proportion of the remainder of life.

Adult↗

PubMed1991

Effect of H2-receptor antagonist pretreatment on vecuronium- and atracurium-induced neuromuscular block.

Seventy-two patients were studied in a double-blind randomized controlled design to assess the effects of oral administration of cimetidine 400 mg, ranitidine 150 mg or placebo 90 min before anaesthesia on the neuromuscular blocking effects of atracurium 0.45 mg kg-1 or vecuronium 0.08 mg kg-1. The times to reappearance of T1 (first response in the train-of-four stimulation) and its recovery to 25% of control were 22.5 (SD) 5.2 and 30 (7.1) min, 30 (10) and 43 (15.4) min, and 25.8 (4.1) and 34 (6.2) min, respectively in the vecuronium groups pretreated with placebo, cimetidine and ranitidine, the times following cimetidine pretreatment being prolonged significantly (P less than 0.05). The respective recovery indices (times for 25-75% recovery of T1) in these three groups were 11.0 (3.5), 17.4 (6.8) and 13.0 (3.9) min. There were no significant differences in any of the variables following ranitidine pretreatment and either neuromuscular blocker or following cimetidine pretreatment and atracurium.

Administration, Oral↗

PubMed1991

Trend of caesarean section in Italy: an examination of national data 1980-1985.

An Italian nationwide presentation of data concerning the proportion of births by caesarean section (CS) for the period 1980-1985 is presented here. A constant increase in CS was noted, from 11.2% in 1980 to 15.8% in 1985. The increase was observed in all regions while higher rates were noted in northern and central Italy. CS rates are higher in older age groups, in pregnancies from 29th to 35th week of gestation for high and low birthweights and malpresentations. Ecological associations revealed that CS is positively related to economic development and negatively to perinatal and stillbirth rates.

Adult↗

PubMed1991

A comparison of different pre-oxygenation techniques in the elderly.

The efficacy of five different techniques of pre-oxygenation before a modified rapid intubation sequence was assessed, using oxygen saturation measurement, in patients aged over 65 years. Twenty patients in each group were pre-oxygenated using four deep breaths or normal tidal breathing for 1, 2, 3, or 4 minutes. The acceptable period of apnoea was defined as the time taken to desaturate to 93%. The mean times (SD) taken to reach this end-point were 3.7 (1.6), 4.1 (1.2), 5.4 (1.7), 5.4 (1.4) and 5.2 (1.7) minutes respectively. The apnoea times with 2, 3 and 4 minutes pre-oxygenation were not significantly different from each other but were significantly longer than after four deep breaths and 1 minute. It is concluded that a pre-oxygenation period of at least 2 minutes should be employed in the elderly before a rapid sequence induction.

Aged↗

PubMed1991

Comparison of the haemodynamic effects of pipecuronium and pancuronium during fentanyl anaesthesia.

Haemodynamic variables were measured following administration of pipecuronium 70 micrograms.kg-1 and pancuronium 90 micrograms.kg-1 (approximately equivalent to 1.5 x ED95) in patients anaesthetised with fentanyl 50 micrograms.kg-1 and scheduled to undergo coronary artery bypass grafting. There were significant increases in heart rate (22%), mean arterial pressure (10%), cardiac index (16%), and the rate pressure product (35%) following administration of pancuronium. The absolute values of these parameters were, however, within acceptable clinical limits. Administration of pipecuronium produced minimal and insignificant changes in these parameters. Other measured or derived indices showed only small changes with both agents and these were generally insignificant. There were no incidences of significant bradycardia following pipecuronium administration. The results from the present study suggest that pipecuronium would have advantages for use in patients with significant cardiovascular disease.

Androstane-3,17-diol↗

PubMed1991

An overview of randomized trials of sodium reduction and blood pressure.

To test for effects on systolic and diastolic blood pressure and to provide precise estimates of their magnitude, we conducted an overview of randomized clinical trials that aimed to reduce the intake of sodium in human subjects. We excluded from pooled analyses trials with confounded designs, those that compared intake levels beyond the usual range in the population, and those without published reports. Two reviewers abstracted information in duplicate and differences were reconciled. Twenty-three trials with outcome data from an aggregate of 1,536 subjects were included. Data were pooled both separately for hypertensive and normotensive subjects and for all trials combined. With the use of sample size weighting, blood pressure reductions (net of controls) were 4.9 +/- 1.3/2.6 +/- 0.8 mm Hg (systolic and diastolic, respectively, with 95% confidence limits) in hypertensive subjects and 1.7 +/- 1.0/1.0 +/- 0.7 mm Hg in normotensive subjects. The combined blood pressure reductions were 2.9 +/- 0.8/1.6 +/- 0.5 mm Hg. These changes were associated with mean reduction of urinary sodium excretion ranging from 16 to 171 mmol/24 hr for individual trials. A dose-response relation across trials was found, both in normotensive and in hypertensive subjects. These results indicate that sodium reduction lowers mean blood pressure in both hypertensive and normotensive individuals for periods of at least several months. The findings are highly consistent with results of observational epidemiological studies and have implications for preventive strategies of blood pressure control.

Blood Pressure↗

PubMed1991

Observational studies of salt and blood pressure.

The observational data relating salt and blood pressure (excluding INTERSALT) are reviewed. Important methodological difficulties and biases are inherent to both across- and within-population studies and confuse their interpretation. Across-population studies are positive but rely on data drawn from the international literature based on a variety of unstandardized field methods; they are prone to unmeasured (ecological) confounding. Within-population studies generally lack statistical power and are subject to major regression-dilution bias (because of considerable day-to-day variation in sodium intake), which could conceal true correlations between sodium and blood pressure. Nevertheless, an overview of reported studies that used 24-hour urine excretion to quantify intake shows positive and highly significant correlations between sodium and blood pressure for both men and women and for systolic and diastolic blood pressures. These results are consistent with the INTERSALT findings and those from trials of sodium restriction.

Blood Pressure↗

PubMed1991

Findings of the International Cooperative INTERSALT Study.

INTERSALT, an international cooperative study on electrolytes and other factors related to blood pressure, found, in within-population analyses involving 10,079 persons, a significant positive association between 24-hour urinary sodium excretion and systolic blood pressure and between the sodium/potassium ratio and systolic blood pressure. These significant findings were derived from analyses for individuals from all 52 centers and from the 48 centers remaining when persons from four low sodium centers were excluded. Potassium excretion of individuals was significantly and independently related inversely to their systolic blood pressure. For men and women, both separate and combined, the relation between sodium and systolic blood pressure was stronger for older than younger adults, perhaps reflecting the result of longer exposure with age or diminished capacity to handle a sodium load. Relations between electrolyte excretion and diastolic blood pressure in individuals were weaker than for systolic blood pressure. Body mass index and heavy alcohol consumption of individuals were strongly and independently related to blood pressure. In cross-population analyses with n = 52 or n = 48, sample median sodium excretion was significantly and independently related to the slope of systolic blood pressure and diastolic blood pressure with age. Other ecological analyses yielded inconsistent results. Four isolated populations showed low sodium excretion, low sodium/potassium excretion, low body mass index, and low alcohol consumption; sample median blood pressures were low, there was little or no upward slope of blood pressure with age, and high blood pressure was rare or nonexistent.

Adult↗

PubMed1991

Sodium and blood pressure: a review of the evidence from controlled trials of sodium reduction and epidemiological studies.

Evidence from controlled trials of sodium reduction and epidemiological studies are consistent in showing that lower urinary sodium excretion is associated with lower blood pressures (BPs) and quantitatively they give similar estimates of effect. An overview of randomised controlled trials gave the estimate that a reduction in sodium excretion averaging 70 to 75 mmol per day lowered BP in hypertensives by 4.9 mmHg systolic and 2.6 mmHg diastolic (p less than .001), and by 1.7 mmHg (p less than .001) and 1.0 mmHg (p less than .01) respectively in normotensives. An overview of within-population epidemiological studies, after correction for intra-individual variability in sodium excretion, gave a pooled (simple) regression estimate that 100 mmol lower sodium was associated with BP lower by 3.7 mmHg systolic and 2.0 mmHg diastolic (p less than .001); and the corrected pooled within-centre regression estimate from INTERSALT, with adjustment for age and sex, was that 100 mmol lower sodium was associated with BP lower by 3.5 mmHg systolic and 1.5 mmHg diastolic (p less than .001), reducing to 2.2 mmHg (p less than .001) and 0.1 mmHg respectively after adjustment for other confounders. Across the centres in INTERSALT, average sodium excretion was positively and significantly related to slope of BP with age, such that 100 mmol lower sodium was associated with a 9 mmHg lower rise in systolic BP from age 25 to age 55 (p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Action of antiepileptic and anaesthetic drugs on Na- and Ca-spikes in mammalian non-myelinated axons.

The actions of the antiepileptic drugs phenytoin, carbamazepine and phenobarbitone, and the local anaesthetic drugs lignocaine and procaine on sodium-dependent and calcium-dependent compound action potentials (Na- and Ca-spikes) have been compared in rat preganglionic cervical sympathetic nerves, using extracellular recording techniques. There was no discernible difference in the frequency dependence of Na-spike block over the frequency range 0.2-20 Hz between these two groups of drugs. However the antiepileptic drugs were more potent blockers of the Ca-spike, whereas the local anaesthetics were more potent on the Na-spike. It is proposed that a dual action of antiepileptics, a frequency-dependent block of sodium currents combined with a block of calcium currents, may explain their efficacy in the treatment of seizures.

Action Potentials↗

PubMed1990

Analysis of the actions of 5-hydroxytryptamine on the rabbit isolated vagus nerve.

Depolarization and reduction in the C fibre compound action potential (C spike) in response to 5-HT were recorded simultaneously from rabbit isolated vagus nerve. 5-HT (0.1-100 mumol/l) was applied either as single concentrations or cumulatively and EC50 and IC50 values measured from individual concentration-response curves. The EC50 values for depolarization (cumulative curves: 2.33, 1.64-3.33 mumol/l, geometric means and 95% confidence limits, n = 31; non-cumulative curves: 3.99, 2.89-5.52 mumol/l, n = 9) were significantly higher than IC50 values for C spike reduction (cumulative curves: 1.25, 0.91-1.74 mumol/l, n = 30; non-cumulative curves: 1.41, 0.72-2.76 mumol/l, n = 8). Complex effects on the C spike were observed, suggesting a susceptible group of C fibres and a 5-HT-resistant component to the C fibre action potential. The motor nerve C fibres in the vagus nerve appear insensitive to 5-HT, whereas the sensory C fibres were sensitive to 5-HT. Phenylbiguanide had a similar selective effect on the C spike, while the depolarizing agents, 1,1-dimethyl-4-phenylpiperazinium (DMPP) and gamma-aminobutyric acid (GABA) did not. Cumulative concentration-response curves for depolarization and C spike reduction could be repeated reproducibly if an interval of 90 min was left between determinations. Up to 6 curves could be generated from one preparation. The 5-HT uptake inhibitor, citalopram (0.1 and 1 mumol/l), had no effect on cumulative concentration-response curves.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

PubMed1990

Antagonism of the effects of 5-hydroxytryptamine on the rabbit isolated vagus nerve by BRL 43694 and metoclopramide.

Depolarization and reduction in the C fibre compound action potential (C spike) in response to 5-HT were recorded simultaneously from rabbit isolated vagus nerve. 5-HT (0.1-100 mumol/l) was applied cumulatively and EC50 and IC50 values measured from individual concentration-response curves. Blockade of 5-HT responses by the 3-indazole carboxamide, BRL 43694, was investigated and compared with the blocking action of metoclopramide. BRL 43694 was a selective antagonist of 5-HT responses. A concentration of 10 nmol/l BRL 43694, which nearly abolished the depolarization and reduction of the C spike evoked by 5-HT (100 mumol/l), had no effect on similar responses evoked by DMPP (100 mumol/l) or GABA (100 mumol/l). Blockade of 5-HT responses by BRL 43694 (0.3 nmol/l) was slow in onset, a plateau blockade occurring after equilibrium of tissue with antagonist for 2 to 3 h. Metoclopramide induced a blockade of rapid onset. The maximal blockade was apparent within 30 min of application. Full recovery in the responsiveness of the tissue to 5-HT was observed within 30 min of washing out metoclopramide. BRL 43694 at concentrations of 0.3, 1, 3 and 10 nmol/l caused a progressive rightward shift of the concentration-response curves to 5-HT. At the highest concentration of antagonist, there was some depression of the maximal 5-HT response. The apparent pA2 estimated from the Schild equation was 10.03 +/- 0.09 (mean +/- SEM, n = 20) against 5-HT depolarization and 10.31 +/- 0.1 against C spike reduction. Schild plots had slopes not significantly different from 1.0.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

PubMed1990

Body mass index versus height and weight in relation to blood pressure. Findings for the 10,079 persons in the INTERSALT Study.

In INTERSALT, an international study of electrolytes and blood pressure, body mass index (kg/m2) was found to relate independently to blood pressure. These relations were assessed in 10,079 men and women aged 20-59 years from 52 centers around the world, based on a standardized protocol, central training of observers, a central laboratory, and extensive quality control. The purpose of the present analyses was to determine whether weight, directly adjusted for height, related to blood pressure as strongly as did body mass index. For all men and women combined, with adjustment for age, sex, alcohol intake, smoking, and sodium and potassium excretion in addition to height, the partial correlations of blood pressure with weight were 0.221 for systolic blood pressure and 0.238 for diastolic blood pressure. These values were slightly larger than the partial correlations for body mass index with blood pressure, which were 0.215 and 0.229, respectively. Although the regression coefficients for body mass index with systolic pressure had been larger in men than in women, suggesting a stronger association of systolic pressure with weight in men, the models with weight directly adjusted for height indicated that the difference in systolic pressure associated with a 10-kg difference in weight was 3.0 mmHg in both men and women. The corresponding weight-associated diastolic pressure differences ranged from 2.00 mmHg in women aged 40-59 years to 2.7 mmHg in men aged 20-39. In addition, with control for weight, height had a significant inverse association with blood pressure. The results of these analyses support the use of weight, with direct adjustment for height, as a useful and practical substitute for body mass index in analyses of the association of adiposity with blood pressure.

Adult↗

PubMed1990

Composite mucinous and granulosa-cell tumor of ovary: case report of a unique neoplasm.

A 63-year-old woman presented with signs and symptoms of an estrogen-producing ovarian tumor. At laparotomy, this tumor proved to be a multilocular right ovarian mass 20 cm in greatest diameter. The cystic spaces were lined by typical benign mucinous epithelium of the endocervical type, while the greatly thickened cyst walls contained a diffuse proliferation of granulosa cells. These two disparate components were intimately mixed at a variably complex interface to form a composite tumor. While composite tumors showing sex cord-stromal and epithelial elements are well documented, they have all, to date, been of moderately to poorly differentiated androblastomatous or Sertoli-Leydig cell type, associated with heterologous mucinous elements of intestinal differentiation. The combination of granulosa-cell tumor with mucinous elements of endocervical or müllerian type has not hitherto been reported and is of uncertain histogenesis.

Adenocarcinoma, Mucinous↗

PubMed1990

Propofol sedation after open heart surgery. A clinical and pharmacokinetic study.

One hundred adult patients who required mechanical ventilation after open heart surgery for coronary revascularisation were studied. All received a standard premedication and a high dose opioid anaesthetic. On arrival in the intensive care unit they were allocated randomly to receive either propofol or midazolam to maintain sedation within a predetermined range. Patients who received propofol underwent extubation of the trachea, using standard criteria, after a mean time (log-transformed) of 7.6 minutes after sedation for approximately 17 hours. The corresponding time was 125 minutes in those given midazolam. There were significantly higher morphine requirements during sedation, and higher arterial carbon dioxide tensions 30 minutes after extubation of the trachea, in patients who received midazolam. Pharmacokinetic analysis in 20 patients showed that the elimination half-life of propofol was prolonged (470 minutes) and clearance was reduced (1.14 litres/minute) compared with subjects who had not undergone cardiopulmonary bypass. The rapid clinical recovery was reflected in a rapid redistribution half-life (13.4 minutes), but this was also longer than the redistribution time of 2-4 minutes in other patients.

Blood Pressure↗

PubMed1990

Comparison of the effects of isoflurane and halothane on intraocular pressure.

Intraocular pressure (IOP) was measured in four groups of patients receiving isoflurane or halothane in consecutively increasing or decreasing concentrations (1.0, 2.0 and 3.0 MAC in 70% nitrous oxide). IOP decreased significantly in all groups irrespective of whether the higher or the lower concentration of the volatile agent was used first. There were no further significant changes in IOP whether the concentrations were increased or decreased, suggesting no dose-relation. Maximum reductions in IOP were slightly greater in those receiving the higher concentrations of the volatile agents first (64 and 66% with isoflurane and halothane, respectively) in comparison to those receiving the lower concentrations first (54 and 46%, respectively).

Adult↗