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Biomedical subjects

R D Ellis

Publications and source records attributed to R D Ellis.

At least 19 recordsLinked to original sources
PubMed1999

Site selection by intestinal helminths of the Virginia opossum (Didelphis virginiana).

Digestive tract helminths of the Virginia opossum (Didelphis virginiana) were examined for site specificity and interspecific interactions. Thirty opossums were live-trapped at 2 localities in Georgia, killed, and their digestive tracts removed and divided into the following sections; esophagus, stomach, small intestine (20 equal sections), cecum, and large intestine (5 equal sections). Helminths present in each section were identified and counted. Three trematode, 1 cestode, 2 acanthocephala, and 6 nematode species were found. Two parasites (the acanthocephalan Centrorhynchus spinosus and the nematode Viannaia hamata) are new state records for Georgia and this is the first report of C. spinosus from an opossum. There was considerable overlap between the spatial distributions of many of the helminth species found in the small intestine though most species had different modal locations. Helminth species locations were unaffected by host sex or trapping locality. There was no evidence that the presence, absence, or intensity of any helminth species affected the location or intensity of other helminth species in the digestive tract.

Animals↗
PubMed1998

Activation of nuclear factor kappa B in Crohn's disease.

OBJECTIVES AND DESIGN: The location and degree of activation of nuclear factor kappa (NFkappaB), a primary transcription factor that plays a regulating role in immune and inflammatory responses, was determined in Crohn's disease using full thickness specimens of bowel collected at surgery. MATERIALS AND METHODS: Resected specimens of inflamed and non-inflamed bowel were collected from thirteen patients with Crohn's disease and non-inflamed bowel from eleven control subjects. Prepared frozen sections were immunostained using a monoclonal antibody to the activated form of the p65 subunit of NFkappaB and the number of positive staining cells counted using a Lennox graticule. RESULTS: The number of cells positive for activated NFkappaB was significantly increased (p = 0.001 ) in all layers of inflamed Crohn's disease bowel, compared to non-inflamed bowel from controls. There was also a significant increase ( p = 0.009) in the number of positive cells, when compared to non-inflamed bowel from control subjects, in the submucosa of non-inflamed areas of Crohn's disease bowel. Cells positive for activated NFkappaB were provisionally identified by morphological criteria as mostly macrophages with some lymphocytes. There was no activation in endothelia. CONCLUSION: NFkappaB is activated within large mononuclear cells in all layers of inflamed areas of the bowel in Crohn's disease and may represent key events in the inflammatory process. Increased activation in the submucosa of non-inflamed Crohn's disease bowel provides further evidence of early immunological activation in macroscopically and microscopically uninvolved areas and an underlying abnormal immune system in Crohn's disease.

Adolescent↗
PubMed1998

Ferric trimaltol corrects iron deficiency anaemia in patients intolerant of iron.

BACKGROUND: Oral iron supplements, which are usually in the form of ferrous (Fe2+) salts, are toxic to the gastrointestinal mucosa, and so intolerance is common, resulting in poor compliance and failure of treatment. The sugar derivative maltol strongly chelates iron, rendering it available for absorption and stabilized in the less toxic ferric (Fe3+) form. AIM: To test whether ferric trimaltol could correct iron deficiency anaemia in patients intolerant of ferrous sulphate. METHODS: Twenty-three patients were recruited from gastroenterology clinics, of whom 1 5 had inflammatory bowel disease, a group often difficult to treat with oral iron. Patients with iron deficiency anaemia and documented intolerance to ferrous sulphate were given 3 months of treatment with ferric trimaltol. RESULTS: Nineteen of 23 patients completed the treatment and anaemia was fully corrected in 14 of these, mean haemoglobin increased from 106 +/- 15 to 126 +/- 16 g/L, and there was a particularly low incidence of side-effects. Of 11 patients with inflammatory bowel disease who completed the study, nine fully corrected their anaemia. CONCLUSION: The results demonstrate that in patients intolerant of ferrous compounds, ferric trimaltol corrects iron deficiency and has a low incidence of side-effects.

Anemia, Iron-Deficiency↗
PubMed1998

Participatory design of an Internet-based information system for aging services professionals.

The Michigan Aging Services System, a World Wide Web-based information system, was developed for practicing gerontologists in the state of Michigan. A participatory design framework adapted from the software development literature guided the development process. Users from Michigan's aging network participated in the development process. Design data were collected using multiple techniques. The system's content was developed with extensive input from actual users. The content emerged into four main categories: News and Current Events, General Information, Policy and Program Information, and Population Information. The system content is briefly compared to that of World Wide Web sites published by other state units on aging.

Aging↗
PubMed1996

Predicting age-related differences in visual information processing using a two-stage queuing model.

Recent work on age-related differences in some types of visual information processing has qualitatively stated that younger adults are able to develop parallel processing capability, while older adults remain serial processors. A mathematical model based on queuing theory was used to quantitatively predict and parameterize age-related differences in the perceptual encoding and central decision-making aspects of a multiple-frame search task. Statistical results indicated main effects for frame duration, display load, age group, and session of practice. Comparison of the full model and a restricted model indicated an efficient contribution of the encoding speed parameter. The best-fitting parameter set indicated that (1) younger participants processed task information with a two-channel parallel system, while older participants were serial processors; and (2) perceptual encoding had a large impact on age-related differences in task performance. Results are discussed with implications for human factors design principles.

Adult↗
PubMed1996

Gero-informatics and the Internet: locating gerontology information on the World Wide Web (WWW).

The Internet, and in particular the World Wide Web (WWW), are growing at a tremendous rate. Information useful to researchers and practitioners in gerontology is scattered and hard to locate, even for experts in the use of the WWW. In order to locate and organize access to this material, a WWW server was developed for gerontologists, using state-of-the-art Internet search techniques. This report provides background on the WWW, reasons for its growth, its potential usefulness to gerontologists, and the results of an exhaustive search of over 300 potential sites. Relevant information was discovered in 5 general categories of gerontology-related information: academic institutions, government agencies, biomedical and health research institutions, general interest sites and data archives.

Aged↗
PubMed1996

Mesenteric vasculitis associated with Sézary syndrome.

A 71 year old lady with Sézary syndrome presented with chronic diarrhoea and cramping abdominal pains. A small bowel meal x ray examination showed two mid-ileal strictures. At laparotomy the small intestine was found to be sub-acutely obstructed and resection of a 15 cm ileal stricture and stricturoplasty of a second, 10 cm stricture were performed. Histological examination of the stricture revealed a mesenteric vasculitis with secondary ischaemic changes in the small bowel wall. Mesenteric vasculitis causing small bowel stricture may be associated with Sézary syndrome.

Aged↗
PubMed1993

False aneurysm complicating closed femoral fracture in a child.

False aneurysms are a recognized but rare complication of closed fractures. The authors report the case of a false aneurysm of the superficial femoral artery complicating a closed transverse fracture of the femoral shaft in a child treated with skeletal traction. The literature of this entity is reviewed.

Aneurysm, False↗
PubMed1991

Exaggerated and prolonged thyrotrophin releasing hormone (TRH) test responses in tertiary hypothyroidism.

A 60 year old man with panhypopituitarism due to a large meningioma and prolonged and exaggerated thyroid stimulating hormone (TSH) responses is described. Initial investigations showed a subnormal urinary free cortisol concentration, a low serum cortisol taken at 0900 hours, and a low free T4 concentration. The TSH was towards the upper end of the normal range. Subsequently pituitary function tests showed subnormal production of luteinising hormone in response to luteinising hormone releasing hormone (LHRH) and a short synacthen test with a low 30 minute cortisol value. Long synacthen testing showed a normal response at four days, confirming that the abnormalities were due to a pituitary or hypothalamic cause. A computed tomogram showed a large meningioma compressing the hypothalamus, pituitary, and temporal lobe. TRH testing showed a prolonged and exaggerated response, consistent with tertiary hypothyroidism.

Humans↗
PubMed1990

Monitoring ovarian cancer using urine cyclic GMP. A two-centre study.

The usefulness of urine cyclic guanosine 3'-5'monophosphate (GMP (cGMP) as a cancer marker in ovarian cancer has been studied in two independent centres using specimens from 81 women. Serial specimens from 60 patients were monitored up to 2 years after the start of chemotherapy. Urine cGMP levels were significantly higher in those patients with poorly differentiated tumours. Levels were not associated with the tumour stage, histological type or residual tumour remaining after surgery. Pretreatment levels were of no value for predicting response to therapy or patient survival. During therapy, however, levels did confirm clinical observations and if a level was elevated then there was a 80-90% chance that the patient was not responding to therapy. Using serial measurements, it was possible to predict the recurrence of tumour in 16/25 patients prior to any other clinical signs.

Biomarkers, Tumor↗
PubMed1989

Effects of BRL 35135, a beta-adrenoceptor agonist with novel selectivity, on glucose tolerance and insulin sensitivity in obese subjects.

BRL 35135 is a novel oral agent which, when dosed chronically to obese rodents with abnormal glucose tolerance, improves both insulin sensitivity and glucose tolerance. To study its effect in man, 10 obese patients on a weight-maintaining diet received BRL 35135 2 mg four times per day for 5 days and then 6 mg four times per day for 5 days. Oral 100 g glucose tolerance tests were performed 1 day prior to and 12 h after the 10-day treatment with BRL 35135. Simultaneously, energy expenditure, glucose oxidation and glucose storage were measured by open-circuit indirect calorimetry. No significant changes in body weight occurred during the 10-day treatment with BRL 35135. Areas under the curves for glucose and insulin were reduced following treatment with BRL 35135 (1518 +/- 152 to 1277 +/- 132 mmol/1/3 h, P less than 0.001 and 13.8 +/- 1.7 to 9.5 +/- 1.3 U/l/3 h, P less than 0.01) (mean +/- s.e.m.). In addition, plasma glucose concentrations, 2h post-oral glucose, were reduced significantly (8.7 +/- 1.0 mmol/l to 6.7 +/- 0.78, P less than 0.01). There was no effect of the treatment on glucose-induced thermogenesis and glucose oxidation did not change but glucose storage increased significantly. The results suggest that BRL 35135 improves glucose tolerance by an increase in insulin sensitivity that is independent of body weight. Glucose storage accounted for the increased glucose disposal.

Adult↗
PubMed1986

Differences between the effects of noradrenaline and the beta-adrenoceptor agonist BRL 28410 in brown adipose tissue and hind limb of the anaesthetized rat.

In mature (450-600 g) 21 degrees C-acclimated male rats, anaesthetized with urethane, blood flow (measured by the radioactive microsphere technique) to brown adipose tissue (BAT) was determined during the infusion of the beta-adrenoceptor agonist BRL 28410 or noradrenaline bitartrate at doses chosen to give similar increases in whole body oxygen uptake. Blood flow to BAT during BRL 28410 infusion was only about one third of that found during noradrenaline infusion although increases in whole body thermogenesis were similar (55 and 77% for BRL 28410 and noradrenaline, respectively). This suggests that BAT may be less involved in the thermogenic response to BRL 28410 than to noradrenaline. In a separate experiment using slightly smaller rats (350-500 g) hind limb oxygen uptake was measured in situ using a venous bypass preparation. BRL 28410, at a dose having a maximum effect on whole body thermogenesis (53% increase), had no effect on oxygen delivery to the hind limb but significantly increased oxygen extraction by 33% (p less than 0.001). In contrast, noradrenaline, also at a dose that maximally increased whole body thermogenesis, led to a 35% decrease in oxygen delivery to the hind limb and no change in oxygen extraction. For the thermogenic beta-agonist BRL 28410 the hind limb, and presumably muscular tissue in general, may be contributing to thermogenesis.

Adipose Tissue, Brown↗