PubMed Health⌕ Search

Biomedical subjects

W D Evans

Publications and source records attributed to W D Evans.

At least 55 records · Page 3Linked to original sources
PubMed1991

Gastric emptying and small bowel transit in male volunteers after i.m. ketorolac and morphine.

Ten male volunteers were studied in a randomized, double-blind crossover trial. Each received ketorolac tromethamine 30 mg and morphine sulphate 10 mg i.m. at an interval of 2 weeks. After a standard radiolabelled meal, gastric emptying half-time (GE) and small intestinal transit time (SIT) were measured using a gamma camera. Small intestinal transit time was measured also from end-tidal breath hydrogen (ETH), and overall gastrointestinal motility by time to first flatus (TFF). Mean GE, SIT and TFF were significantly prolonged by morphine compared with ketorolac (P less than 0.03); ETH was prolonged also, but the difference was not significant. There were no significant correlations between SIT, ETH and TFF. Most subjects reported adverse effects after morphine, but only one after ketorolac.

Adult↗
PubMed1990

The relationship between spinal trabecular bone mineral content and iliac crest trabecular bone volume.

The relationship between spinal trabecular bone mineral density and iliac crest trabecular bone volume has been studied in 84 patients, 23 with primary osteoporosis, 19 with osteoporosis secondary to inflammatory bowel disease, and 42 with nonsteroid-treated rheumatoid arthritis. Spinal trabecular bone mineral density was measured in the first three lumbar vertebrae by quantitative computed tomography, and iliac crest trabecular bone volume was assessed histomorphometrically in sections from trans-iliac biopsies using computerized techniques. In all 84 patients, there was a significant positive correlation between the two measurements (r = 0.60, P less than 0.001). However, when the three patient groups were analyzed separately, a significant correlation was found in the group with secondary osteoporosis (r = 0.65, P less than 0.01) but not in the patients with primary osteoporosis (r = 0.07) or rheumatoid arthritis (r = 0.19). These results indicate that the relationship between spinal trabecular bone mineral density and iliac crest trabecular bone volume differs according to the underlying disease process, these differences possibly reflecting variations in skeletal patterns of bone loss in different types of osteoporosis.

Adolescent↗
PubMed1990

OC125 immunoscintigraphy in ovarian carcinoma: a comparison with alternative methods of assessment.

The membrane bound, tumour associated antigen CA125 is recognized by the monoclonal antibody OC125 and may be detected in tumour tissue and serum in over 80% of patients with epithelial ovarian carcinomas. A total of 13 immunoscintigrams using 111 MBq 131I-OC125 have been performed in 11 patients. The results have been compared with clinical examination, CT and ultrasound scans, surgical findings and serum CA125 concentrations. Macroscopic disease was present at the time of scanning in 11 patients (less than 2 cm, eight patients, greater than 2 cm, three patients). Clinical examination and ultrasound were positive in three, CT scanning in four, immunoscintography in seven and serum CA125 in eight patients. This pilot study suggest that serum CA125 estimation is the most sensitive indicator of disease activity. However, immunoscintigraphy using this agent may localize residual disease when clinical examination and other radiological investigations fail.

Antibodies, Monoclonal↗
PubMed1990

Temporal instabilities associated with a planar high purity germanium detector.

Experiments have been performed which show that a grooved planar high purity germanium semiconductor detector may give rise to time variant counting rates in energy regions below prominent spectral peaks. It is postulated that this effect is due to prolonged or incomplete charge collection in the vicinity of the bottom of the groove, and is caused by distortions in the applied electric field in this region. Such effects may lead to changes in the minimum detectable count rate in x-ray fluorescence measurements; these can be reduced by collimating incident photons on the central region of the detector but the resulting reduction in efficiency lowers the overall sensitivity.

Radiometry↗
PubMed1988

A theoretical analysis of the accuracy of single-energy CT bone-mineral measurements.

A relationship has been derived between the in vivo concentration of calcium hydroxyapatite and the in vitro concentration of K2HPO4 solution in a single-energy quantitative computed tomography (QCT) bone-mineral determination. Under certain simplifying assumptions this relationship is linear. The gradient term has been calculated as a function of scanner effective energy using the measured variation of solvent water density with K2HPO4 concentration; it ranges from 1.17 at 60 keV to 1.21 at 80 keV. The intercept term has been calculated as a function of effective energy, patient age and trabecular bone volume (TBV) by modelling the constituents of whole trabecular bone and using published normal composition data. It varies from about 15 to 25 mg cm-3 at an effective energy of 70 keV and within a TBV range of 5 to 20%. This intercept term may be used as an additive correction which improves the accuracy of single-energy QCT results without significant loss of precision. However, the method is limited by the uncertainties of tissue composition in an individual patient.

Bone and Bones↗
PubMed1988

Bone mineral content in normal UK subjects.

Bone mineral content in the lumbar vertebrae and in the shaft of the left radius has been measured in 129 normal British subjects using quantitative computed tomography and single-photon absorptiometry. Significant negative correlations between bone mineral content and age were found at both sites in males and females (p less than 0.001 in all cases). When expressed in g/cm the bone mineral content in the radial shaft showed significant positive correlations with body height and weight in both sexes, but after correction for bone size only a weak correlation with body height in males was found. Spinal trabecular bone mineral content showed no significant correlations with body height or weight in either sex. Comparison of the values obtained with normal data from centres in the USA revealed lower mean values for both radial and spinal bone mineral content in the British subjects. These differences emphasize the importance of using locally derived normal data for comparison with values obtained from patients.

Adolescent↗
PubMed1987

Osteoporosis in patients with inflammatory bowel disease.

Bone mineral content in spinal trabecular and peripheral cortical bone was measured in 75 unselected patients with small and/or large intestinal inflammatory bowel disease. Osteoporosis, defined as a bone mineral content greater than 2 SD below the age and sex matched normal mean value was present in 23 patients (30.6%). Three amenorrhoeic females aged 34, 38, and 42 years had severe clinical osteoporosis and a further three patients had one or more vertebral crush fractures. Eighteen of the 23 patients with osteoporosis had small intestinal disease with one or more resections and the mean lifetime steroid dose in those with osteoporosis was significantly higher than in those with normal bone mineral content. Bone mineral content in spinal trabecular bone showed significant negative correlations with lifetime steroid dose and serum alkaline phosphatase and a significant positive correlation with serum albumin. Peripheral cortical bone mineral content was positively correlated with body weight, height and body mass index. We conclude that the prevalence of osteoporosis is increased in patients with inflammatory bowel disease, severe clinical osteoporosis developing in some relatively young patients. The pathogenesis of this bone loss is probably multifactorial; steroid therapy is likely to be an important contributory factor.

Adult↗
PubMed1978

Portal hypertension in vinyl chloride monomer workers. A hemodynamic study.

Hemodynamic studies were performed in 5 vinyl chloride monomer workers in whom splenomegaly or thrombocytopenia was detected during a screening program at major chemical plant. Three patients had portal hypertension and collateral venous circulations, with intrasplenic pressures between 20 and 29 mm Hg and normal wedged hepatic venous pressures, but the gradient between the wedged and free hepatic vein pressures was also increased. Splenic blood flows were increased in both hypertensive and normotensive patients. There was no correlation between the splenic blood flow and the portal pressure or the presence of portal fibrosis. The portal hypertension associated with vinyl chloride exposure is mainly presinusoidal in type, and may be attributed to an abnormality of the portal vein radicles, or hepatic sinusoids.

Adult↗
PubMed1977

Preliminary results from Solrad 11 gamma-burst detectors.

We present here temporal and 0.2-2 MeV spectral data from two gamma bursts observed on 12 June and 16 August 1976, by detectors on the Solrad 11A and 11B satellites. The 12 June burst showed evidence for structure on time scales down to approximately 10 ms throughout its lifetime, whereas the 16 August burst varied only with characteristic times longer than a few tenths of a second. A search for both slow and fast spectral variability gave negative results. Accurate absolute burst times are, however, not yet available, but since both bursts were also observed by at least one Vela satellite, positions are calculable and will be reported.

Journal Article↗
PubMed1969

Food buying.

Explore the source record for details and available documents.

Food↗
PubMedDate not supplied

Somatic characteristics and cardiovascular risk factors in growth hormone deficiency: a randomized, double-blind, placebo-controlled study of the effect of treatment with recombinant human growth hormone.

The purpose of the present study was to identify the effect of treatment with recombinant human growth hormone (rhGH) on seven somatic characteristics and eight clinical cardiovascular risk factors. Twenty-seven male and 24 female patients between the ages of 21 and 60 years were examined. The investigation was a double-blind, placebo-controlled study of 12 months duration. Patients were assigned randomly to treatment (T) and placebo (P) groups. In the first 6 months group T received rhGH and group P placebo. In the second 6 months both groups received rhGH. Complete data were available for 23 males and 20 females. Increments were calculated between 6 months -BL (increment 1) and 12-6 months (increment 2) in both T and P groups. Apart from the somatotype, data were analysed with a 2 x 2 mixed analysis of variance (ANOVA) using treatment (rhGH and placebo) and time (increments 1 and 2). Somatotype data were analysed using a 2 x 3 multivariate ANOVA. Three significant interactions were identified in males: waist circumference (P = 0.006), trunk fat (P = 0.0001), and conicity index (P = 0.001). The only significant interaction in females was trunk fat (P = 0.006). In general, treatment and placebo groups responded differently by time and treatment. Responses were similar in males and females. In the first 6 months when group P was on placebo, waist circumference, trunk fat, and conicity index increased slightly; with group T on rhGH somatic variables declined markedly. In the second 6 months when both groups received rhGH there was a marked decline in group P and a continued decline (but less steeply) in group T. In males there were significant decreases in endomorphy in group T and increases in mesomorphy in group P. In females the somatotype remained stable. There were no significant interactions in clinical cardiovascular risk factors in either males or females. Favourable responses occurred in male and female lipid profiles, although these were not significant. It was concluded that in males waist circumference, trunk fat, conicity index, and somatotype responded significantly to treatment with rhGH; in females the only significant response was trunk fat.

Adult↗
PubMedDate not supplied

Factors affecting the in vivo precision of bioelectrical impedance analysis.

The influence of factors which affect the in vivo precision of bioelectrical impedance measurements was investigated in two young female volunteers. Measured impedance increased consistently with time with the subject lying supine, although the effect could be eliminated by rising between measurements. Electrode placement had a relatively large effect, while moving the electrodes such that the volume of conducting tissue was reduced caused the impedance to decrease. Cleaning the skin with alcohol, moving the arm away from the body, and eating a large meal caused impedance to increase systematically. However, drinking a litre of water and varying the depth of respiration had no observable effect.

Adult↗