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Biomedical subjects

D Evans

Publications and source records attributed to D Evans.

At least 235 records · Page 13Linked to original sources
PubMed1992

The validity of estimating heart disease reduction from a Framingham logistic equation.

We compared two ways in which a logistic equation could be used to estimate the number of heart disease events prevented after lowering blood cholesterol levels. Men were selected from an Australian population survey who met the entry criteria of the Lipid Research Clinics Coronary Primary Prevention Trial (LRC-CPPT). The numbers of heart disease events expected over 7.4 years were calculated from the logistic equation after reducing the men's blood cholesterol by the amounts achieved in the LRC-CPPT placebo and treatment groups (our simulated placebo and treatment groups). The number of events prevented was calculated as the absolute difference between the simulated groups (9.48 per 1000 men per 7.4 years) and the percentage difference of the simulated groups multiplied by the observed incidence rate in the LRC-CPPT placebo group (13.66 per 1000 men per 7.4 years). The second estimate was closer to that observed in the LRC-CPPT (17.10 per 1000 men per 7.4 years), and we recommend this approach in cost-effectiveness studies.

Australia↗
PubMed1992

Instrumental comparison for the determination of cadmium and lead in calcium supplements and other calcium-rich matrices.

Three brands of Ca supplement, a laboratory-reagent grade CaCO3 and a certified reference material (International Atomic Energy Agency H-5 Animal Bone) wee analysed for Cd and Pb by four different analytical techniques, viz., anodic stripping voltammetry inductively coupled plasma mass spectrometry, flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry. The Pb levels measured by the four techniques in the bone powder were within the certified Pb level in this certified reference material. Similarly, no significant differences [p less than 0.05; analysis of variance (ANOVA)] were observed in samples with Pb concentrations greater than 1 microgram g-1. However, the Pb levels in the laboratory-reagent grade CaCO3 obtained by flame atomic absorption spectrometry (0.79 micrograms g-1) averaged about three times higher than those measured by the other three techniques (i.e., 0.25 micrograms g-1). Although no significant differences (p less than 0.05; ANOVA) in Cd levels were observed within any of the samples (intra-sample variability), the Cd concentration measured in the different Ca supplements (inter-sample variability) varied by three orders of magnitude (ranging from 0.07 to 3.59 micrograms g-1).

Analysis of Variance↗
PubMed1992

Expression of elongation factor-1 gamma-related sequence in human pancreatic cancer.

A cDNA clone designated pPDC-1 was isolated from a cDNA library prepared against poly(A+)RNA isolated from the human pancreatic adenocarcinoma cell line, Capan-2. The cDNA corresponds to a 1.7-kilobase mRNA that is expressed at higher levels in seven of nine pancreatic tumors than in their corresponding normal tissues. It is also expressed in normal human kidney, intestine, pancreas, stomach, placenta, lung, brain, spleen, and liver. A computer search of the Intelligenetics System of all available nucleotide sequences revealed a 60% homology between the nucleotide sequence of the pPDC-1 cDNA and that of elongation factor-1 gamma from Artemia. The deduced amino acid sequence shared 53% identity with the amino acid sequence for the Artemia elongation factor-1 gamma.

Aged↗
PubMed1992

The cost and availability of devices for preventing childhood injuries.

Accidental injury is the major cause of death among Australian children. Many childhood injuries are preventable through the use of safety devices such as those recommended by the Child Accident Prevention Foundation of Australia (CAPFA). It has been suggested that poor availability and the high cost of obtaining and installing safety devices may contribute to their low rates of use among families with young children. This paper assesses the availability and cost of recommended safety devices in a medium sized city in Australia. Of the 17 devices recommended by the CAPFA only 10 were readily available in Newcastle. The cost of purchasing and installing all the devices recommended by CAPFA amounted to $1516, or 21.4% of the annual disposable income, after the purchase of necessities, of families with children and 75.5% of the annual disposable income, after purchase of necessities, of single parents. It is argued that the cost of safety devices may be prohibitively expensive, particularly for those most at risk of suffering from injury.

Accident Prevention↗
PubMed1992

Leishmaniasis diagnosed from bronchoalveolar lavage.

A 51-year-old renal transplant patient, whose spleen had been removed 11 years ago, was admitted to hospital for elective surgery, which was cancelled as she developed spiking fever and nonproductive cough and her general condition deteriorated. After 2 weeks, leishmaniasis was unexpectedly diagnosed from a bronchoalveolar lavage specimen, which had been subjected to parasitological examination under the suspicion of pneumocystosis. Isoenzyme typing identified the parasite as Leishmania infantum. The patient had visited Malaga, Spain, twice a year, the last trip taking place 1 month before admission. Specific treatment was followed by rapid recovery without relapse during 1.5 years. Splenectomy and immunosuppressive medication obscured the clinical suspicion of leishmaniasis. The case is a reminder of the interstitial pneumonitis in leishmaniasis and emphasizes the value of broad-spectrum methods detecting a variety of parasites.

Animals↗
PubMed1992

para-amino benzoic acid in the assessment of completeness of 24-hour urine collections from hospital outpatients and the effect of impaired renal function.

Eighteen (29%) of 24-h urine collections made by 63 hospital outpatients attending a gastroenterology clinic were incomplete, as judged by 24 h urine recovery of an oral marker, para-amino benzoic acid (PABA), despite more than the usual efforts to obtain complete collections. Incomplete collections contained significantly less sodium, urea and total nitrogen than full collections. Average outputs were 134 mmol and 103 mmol per day for sodium (P less than 0.02); 301 mmol and 223 mmol for urea (P less than 0.001); and 10.1 g and 8.3 g nitrogen (P less than 0.01) in the complete and incomplete collections respectively. In renal outpatients with a plasma creatinine in excess of 125 mumol per litre, urine recoveries of PABA were reduced, but within the expected range in renal patients whose plasma creatinine was normal.

4-Aminobenzoic Acid↗
PubMed1991

Smoking and mortality among older men and women in three communities.

BACKGROUND: Although cigarette smoking is the leading avoidable cause of premature death in middle age, some have claimed that no association is present among older persons. METHODS: We prospectively examined the relation of cigarette-smoking habits with mortality from all causes, cardiovascular causes, and cancer among 7178 persons 65 years of age or older without a history of myocardial infarction, stroke, or cancer who lived in one of three communities: East Boston, Massachusetts; Iowa and Washington counties, Iowa; and New Haven, Connecticut. At the time of the initial interview, prevalence rates of smoking in the three communities ranged from 5.2 to 17.8 percent among women and from 14.2 to 25.8 percent among men. During five years of follow-up there were 1442 deaths, 729 due to cardiovascular disease and 316 due to cancer. RESULTS: In both sexes, rates of total mortality among current smokers were twice what they were among participants who had never smoked. Relative risks, as adjusted for age and community, were 2.1 among the men (95 percent confidence interval, 1.7 to 2.7) and 1.8 among the women (95 percent confidence interval, 1.4 to 2.4). Current smokers had higher rates of cardiovascular mortality than those who had never smoked (as adjusted for age and community, the relative risk was 2.0 [95 percent confidence interval, 1.4 to 2.9] among the men and 1.6 [95 percent confidence interval, 1.1 to 2.3] among the women), as well as increased rates of cancer mortality (relative risk, 2.4 [95 percent confidence interval, 1.4 to 4.1] among the men and 2.4 [95 percent confidence interval, 1.4 to 3.9] among the women). In both sexes, former smokers had rates of cardiovascular mortality similar to those of the participants who had never smoked, regardless of age at cessation, whereas the rates for all cancers, as well as smoking-related cancers, remained elevated among men who had once smoked. CONCLUSIONS: Our prospective findings indicate that the mortality hazards of smoking extend well into later life, and suggest that cessation will continue to improve life expectancy in older people.

Age Factors↗
PubMed1991

Review of research instruments and techniques used to detect delirium.

Over the past several decades, numerous investigators have studied the syndrome of delirium. Researchers have relied on a number of different case finding methods to detect the syndrome. This paper provides an overview of instruments used in studies of delirium. We assess the validity and reliability of these instruments and compare the advantages and disadvantages of the different methods. We then present the rationale for the development of the Delirium Symptom Interview, an instrument constructed for use in the Commonwealth-Harvard Study of delirium in elderly hospitalized patients.

Aged↗
PubMed1991

Voltammetric behaviour of salicylic acid at a glassy carbon electrode and its determination in serum using liquid chromatography with amperometric detection.

Cyclic voltammetry was used to investigate the oxidation of salicylic acid at a planar glassy carbon electrode. The electrode reaction was found to be dependent on the pH and ionic strength of the acetate buffer, which contained 35% methanol. Under these conditions the maximum electrochemical signal was obtained with a supporting electrolyte of 0.06 mol dm-3 acetate buffer in 35% methanol (pH 5.0). The peak current value (ip) increased by approximately 10% when the methanol concentration was decreased to 8%. The substance was found to undergo an irreversible reaction involving one electron and possibly two protons in the initial oxidation step with at least one possible quasi-reversible follow-up reaction. The optimum mobile phase for the liquid chromatography, with amperometric detection, of the serum extracts was found to be 0.06 mol dm-3 acetate buffer in 8% methanol (pH 5.0); the acidified serum was extracted with a mixture of chloroform and acetonitrile (60 + 40), prior to injection onto a reversed-phase column. The peak current was measured at +1.35 V and the calibration graph was found to be linear in the range 4-200 ng of sample injected. The average recovery from serum was found to be 60% with a relative standard deviation of 5.8%. A pharmacokinetic study was carried out and the results obtained were comparable to those found in the literature. It was concluded that the method developed had possible application for the measurement of trace levels of salicylic acid in clinical studies.

Chromatography, High Pressure Liquid↗
PubMed1991

Recognition of poliovirus/HIV chimaeras by antisera from individuals with HIV infection.

The neutralization of five poliovirus/HIV chimaeras by serum from HIV-infected individuals was examined to evaluate the presentation of HIV envelope sequences, to assess the immune response of individuals to specific epitopes, and to relate it to the stage of disease. The sera were unable to differentiate between four of the chimaeras and the Sabin vaccine strain. With a fifth construct containing an immunodominant gp41 sequence, significant differential recognition was observed in approximately 67% of individuals with asymptomatic HIV infection [groups II and III of the Centers for Disease Control (CDC) classification of HIV infection] and 37% of patients with symptomatic disease (CDC group IV). Furthermore, among patients with CDC stage IV disease antibody levels against this construct and the titre achieved decreased with progression to further disease from approximately 40% in AIDS-related complex (ARC) patients (CDC group IVA and IVC-2 to 14% in those with AIDS (other group IV diseases). Loss of antibody to this construct did not result from a reduction in the anti-polio or anti-envelope response, but from a decline in antibody levels to the HIV sequence inserted in antigenic site 1.

Amino Acid Sequence↗
PubMed1991

Reversal by omeprazole of the depression of gastrin cell function by fasting in the rat.

1. Gastrin (G)-cell function is controlled by gastric acid, which has inhibitory effects, and food in the gastric lumen, which has stimulatory effects. We have examined the role of acid in mediating the depression of G-cell function that occurs in fasting in the rat. 2. Rats were fasted for 48 h, and received either the H(+)-K(+)-ATPase inhibitor omeprazole, to reduce acid secretion, or vehicle. Basal acid secretion was not significantly different after fasting for 24 or 48 h. Fasted rats which received omeprazole were achlorhydric. 3. In rats treated with vehicle and fasted for 48 h, plasma and tissue gastrin concentrations were significantly depressed. The fall in both parameters suggests an inhibition of gastrin synthesis and consistent with this a decrease was observed in tissue gastrin mRNA abundance and in phosphorylation of progastrin-derived peptides. 4. In fasted rats treated with omeprazole, tissue gastrin concentrations were not significantly different from those of rats fed ad libitum, but plasma gastrin concentrations were significantly higher than in rats fed ad libitum. Gastrin mRNA abundance and the phosphorylation of progastrin-derived peptides in omeprazole-treated rats was not significantly different from rats fed ad libitum. 5. The data suggest that the depression of G-cell function which occurs in fasted rats can be attributed to the inhibitory action of intraluminal acid on the G-cell. Gastric acid appears to regulate several different aspects of G-cell function, including gastrin synthesis, post-translational processing and secretion.

Animals↗