Search PubMed⌕ Search

Biomedical subjects

G Young

Publications and source records attributed to G Young.

At least 109 records · Page 6Linked to original sources
PubMed1997

Clinical comparison of Omafilcon A with four control materials.

PURPOSE: The purpose of this study was to assess the clinical performance of hydrogel contact lenses manufactured from a novel, biomimetic, 59% water content, hydrogel material (Omafilcon A) as compared with a representative range of control materials (Polymacon, Etafilcon A, Atlafilcon A, and Welcon CE). METHOD: Thirty subjects were enrolled in a 2-month, double-masked, randomized, comparative, daily wear study. Subjects wore two sets of lenses; each pair was worn for 1 month. In each part of the study, subjects wore a Proclear (Biocompatibles Ltd.) test lens (Omafilcon A) in one eye and a control lens in the other eye. In vivo lens dehydration was measured after 1 week of lens wear. Lenses were collected at the end of the study and subjected to in vitro spectrofluorimetric analysis to measure protein and lipid deposits. RESULTS: Omafilcon A showed significantly less lipid spoilation than all the controls and significantly less protein than the Etafilcon A and Atlafilcon A lenses. High levels of protein were found on the Group 4 lenses (Etafilcon A) and high levels of lipid were found on the Group 2 lenses (Weicon CE). The Omafilcon A lenses exhibited significantly less on-eye dehydration than the Etafilcon A lenses (P < 0.0001) and the Weicon CE lenses (P < 0.005). The majority of subjects expressed a preference for the Proclear lens, generally for reasons of comfort. Some minor differences in aspects of lens fit were noted between the test and control lenses, however, none of these were felt to be great enough to affect comfort. CONCLUSIONS: We hypothesize that the reduced spoliation seen with the Omafilcon A lens relates to the biomimetic nature of the material which incorporates phosphorylcholine.

Adsorption↗
PubMed1996

Prospective regional study of planned home births. Home Birth Study Steering Group.

OBJECTIVE: To collect data from a cohort of women requesting a home birth and examine the experience and outcome of pregnancy, the indications for hospital transfer, and the attitudes of mothers, midwives, and general practitioners. DESIGN: Follow up study with anonymised postal questionnaires. SETTING: Northern Regional Health Authority area. SUBJECTS: The 256 women resident in the Northern region who expected to deliver in 1993 and whose request for a home birth became known to one of the local supervisors of midwives. Limited cross validating information was also collected retrospectively on all other women delivering a baby outside hospital in 1993. MAIN OUTCOME MEASURES: Rate of and reason for transferred care; maternal, midwifery, and general practitioner views; perinatal outcome. RESULTS: Five women miscarried, leaving 251 in the study. Of these, 142 (57%) delivered at home. There were 17 (7%) caesarean sections but no perinatal deaths. General practitioners had reservations about half of the booking requests. Two thirds of the women thought they had not been offered any option about place of birth, 74 (29%) were referred to hospital for delivery before the onset of labour, and 35 (14%) were referred to hospital during labour. Intrapartum transfers were uneventful, and half the mothers commented spontaneously that they valued having spent even part of their labour at home. CONCLUSIONS: Home birth is valued for its family setting. General practitioners' support is sought and influential but uncommon, possibly because of a lack of understanding of the responsibilities of the midwife and general practitioner.

Attitude of Health Personnel↗
PubMed1996

11-Ketotestosterone suppresses interrenal activity in rainbow trout (Oncorhynchus mykiss).

Interrenal activity in relation to sexual maturity in male rainbow trout, and the effects of in vivo treatment with 11-ketotestosterone (11-KT) were investigated. Silastic pellets containing either 11-KT or no steroid were implanted in maturing male and immature male and female rainbow trout for a total of 11 weeks. Two weeks before termination of the experiment, animals were subjected to crowding, and blood samples were taken 15-90 min after initial disturbance. At the termination of the experiment, head kidneys containing interrenal cells were removed and incubated in vitro with either human adrenocorticotropin 1-24 (ACTH) or with pregnenolone. 11-KT reduced the elevation of cortisol in response to confinement stress. Head kidney tissue of control and 11-KT-treated maturing males was significantly less responsive to ACTH and pregnenolone than tissue from immature males. Treatment of immature females with 11-KT similarly led to reductions in interrenal responsiveness. No difference in response was seen between tissue from control immature males and females. These data suggest that the attenuated stress response in maturing males is due, in part, to elevated 11-KT levels acting at one or more levels of the hypothalamus-pituitary-interrenal axis.

Adrenocorticotropic Hormone↗
PubMed1996

"My most meaningful patient". Reflective learning on a general medicine service.

OBJECTIVE: To determine the usefulness of critical-incident reports in facilitating reflective learning and the types of experiences that learners found meaningful on a general medicine service. DESIGN: Team members wrote about their most meaningful patient of the month and what was learned from the patient. They shared their narratives during teaching rounds at the end of each month. The written reports were collected and subjected to qualitative thematic analysis. SETTING: General medicine teaching service of an academic medical center. PATIENTS/PARTICIPANTS: Medical students, residents, and attending physicians. MEASUREMENTS AND MAIN RESULTS: Ninety-eight reports were collected over 10 months and subjected to thematic analysis. Reports were coded for six major themes, with a mean of 2.09 themes per narrative. The number of reports containing each theme was 47 for biomedical, 46 for communication with patients and families, 38 for psychosocial, 32 for the physician's role, 30 for personal feelings, and 14 for ethics. Communication issues constituted the theme most frequently reported by third-year students; biomedical and psychosocial themes by interns; biomedical by supervising residents; and the physician's role by attending physicians. Reports from men and women contained a similar mean number (men 2.101; women 2.128) and distribution of themes. CONCLUSIONS: The critical-incident technique promoted reflection on the meaning of clinical experiences. Qualitative thematic analysis revealed the diversity of meaningful experiences on a general medicine service and the high frequency of nonbiomedical themes. This study suggests that reflective exercises can provide a window into the experience of students and residents.

Clinical Medicine↗
PubMed1996

Altered bowel function and duodenal bacterial overgrowth in patients treated with omeprazole.

BACKGROUND: The dramatic inhibitory effect of proton pump inhibitors on acid secretion has raised concern about possible side-effects, such as small bowel bacterial overgrowth, which may result in further gut dysfunction. The aim of this study was to assess the effect of proton pump inhibitors on duodenal bacteriology, carbohydrate absorption and bowel habit. METHODS: Small bowel bacterial overgrowth and xylose absorption were measured by culture of aspirated duodenal fluid and a combined 1 g 14C-D-xylose absorption-metabolism test in 20 patients with peptic ulcer disease. Tests were repeated after 4 weeks of treatment with omeprazole 20 mg daily. Intestinal transit was assessed by recording interdefecatory intervals and stool form. RESULTS: All patients showed an increase in duodenal bacterial counts following treatment, geometric mean counts increasing from 330 to 95000 CFU/mL. The geometric mean of the difference was 290 CFU/mL (95% CI, 110-720 CFU/mL; P < 0.0001). No changes were noted in the xylose absorption or metabolism tests. Mean interdefecatory intervals decreased by 32% from 31.7 to 21.6 h, the mean difference being 10.1 h (95% CI, 1.6-18.5 h: P = 0.01). The mean stool form index increased from 2.95 to 4.70, mean difference 1.75 (95% CI, 1.10-2.40: P < 0.0001), with four patients reporting diarrhoea. CONCLUSION: The results indicate that conventional treatment for duodenal ulcers with a proton pump inhibitor significantly increases bacterial colonization of the duodenum and the speed of intestinal transit.

Adult↗
PubMed1996

General practitioners' views about the need for a stress support service.

OBJECTIVES: We wished to determine general practitioners' (GPs') views regarding the need for a stress support service. METHOD: A postal questionnaire survey of GPs' views (n = 274) about the need for a stress support service, and what form such a service might take, was undertaken on Tyneside. RESULTS: A response rate of 79.5% was achieved with one reminder. A majority (78.8%) were in favour of a stress support service for GPs, the most popular options for the service being independently accessed counsellors and stress management groups. Over 90% of respondents thought that support should be available to any doctor, and 65% that is should be available to all primary health care team members. The five most commonly mentioned causes of stress were: time and workload problems; on call; expectations and demands of patients; administration and paperwork; and complaints and fear of litigation. CONCLUSIONS: The survey demonstrated widespread concern amongst GPs on Tyneside about stress levels and considerable interest in the idea of stress support. However, a variety of approaches would be required to meet the range of perceived needs, and any such services should be made accessible to all practitioners regardless of whether they are actually suffering from stress, as well as to other members of the primary health care team.

Adult↗
PubMed1996

Evaluation of soft contact lens fitting characteristics.

The assessment of soft contact lens fit by observation of the lens behavior on the eye is one of the most common procedures undertaken in contact lens practice. Nevertheless, the guidelines for doing so have been derived empirically with little or no research into the usefulness of these observations. Over 2000 evaluations of soft contact lens fit were analyzed to determine the predictive value of various indicators of contact lens fit, namely: subjective comfort, lens centration, postblink movement (PBM), version and upgaze lag, and tightness assessed by the push-up test. The receiver-operator characteristic (ROC) curves were prepared for each variable by plotting sensitivity values against false positive rates (FPRs) for various cut-off points. Sensitivity was defined as the proportion of "bad" fits correctly identified by a given variable; FPR was defined as the proportion of "good" fits incorrectly identified as bad fits. With each fitting variable, the optimum cut-off point and its corresponding sensitivity and FPR were determined from the ROC curves. Subjective comfort was found to be of little value in identifying tight fitting lenses but was of some limited value in identifying loose fitting lenses, particularly high water content (HWC) lenses. The push-up test was the most accurate single test of lens fit acceptability having a high sensitivity for both tight (92%) and loose (80%) lens fits. Assessment of PBM was a sensitive indicator of tight fitting lenses (95%), but was a poor indicator of loose fitting lenses, having a low sensitivity (51%). Assessment of version lag showed better sensitivity than upgaze lag in assessing loose fits, whereas upgaze lag showed better sensitivity for tight lens fits. Lens centration was of no predictive value in identifying tight fitting lenses but, as expected, was of some value in identifying loose fitting lenses. The results of this study enable a critical reassessment of the procedures that practitioners follow when fitting soft contact lenses.

Contact Lenses, Hydrophilic↗
PubMed1996

Cost-effectiveness analysis of screening by faecal occult blood testing for colorectal cancer in Australia.

The incremental costs and effects of annual faecal occult blood test screening in Australia were modelled for a hypothetical cohort of 1000 persons offered screening or not offered screening. Incremental costs and effects were estimated as the differences in direct health care costs (Australian costs) and years of life remaining between the annual-screen group and the control (no screen) group, based on the published results of the Minnesota randomised controlled trial. The cost per life year saved was $24,660. The greatest source of variability in the cost-effectiveness ratio is the effectiveness of screening. The 95 percent confidence interval for cumulative mortality in the annual-screen group is 3.86 to 7.9 per 1000, assuming the control rate is fixed at 8.83 per 1000. With this confidence interval, the cost per life year saved ranges from $12,695 to $67,848. The cost-effectiveness ratio increases to $48,000 if no mortality benefit is assumed beyond the end of the trial follow-up period, 13 years. The results are sensitive to the cost of colonoscopy (at $400 per colonoscopy, the cost per life year saved is $12,319) and the false-positive rate. The cost-effectiveness of colorectal cancer screening is comparable with that of other screening programs but further evidence is needed on the efficacy of screening. Whether the benefits of colorectal cancer screening outweigh the harm and costs needs to be more certain before more resources are committed to mass screening. Health policy planners should initiate planning for Australian pilot projects in the event that the efficacy of screening is confirmed by two current studies.

Australia↗
PubMed1996

Molecular cloning of the cDNAs encoding pituitary glycoprotein hormone alpha- and gonadotropin II beta-subunits of the Japanese eel, Anguilla japonica, and increase in their mRNAs during ovarian development induced by injection of chum salmon pituitary homogenate.

cDNAs encoding the glycoprotein hormone alpha- and gonadotropin (GTH) II beta-subunits of Japanese eel (Anguilla japonica) pituitary were cloned using the polymerase chain reaction. The nucleotide sequence of the glycoprotein hormone alpha-subunit cDNA was 364 base pairs (bp) long, encoding 117 amino acids, and that of the GTH II beta-subunit cDNA was 433 bp long, encoding 140 amino acids. The deduced amino acid sequence of each mature subunit showed high homology with those of other teleosts, indicating that the structure of GTH subunits has been conserved during the evolution of teleosts. Changes in the expression of these subunit genes during ovarian development induced artificially by the injection of chum salmon pituitary homogenate were examined using Northern blot analysis. Glycoprotein hormone alpha-subunit mRNA increased almost linearly during ovarian development, whereas GTH II beta-subunit mRNA was detected only at the late vitellogenic and migratory nucleus stages. These data indicate that eel GTH II is synthesized mainly at the late vitellogenic and migratory nucleus stages, and suggest that GTH II plays an important role in final oocyte maturation of Japanese eel. Changes in the expression of glycoprotein hormone alpha- and GTH II beta-subunits mRNA correlate with the serum estradiol-17 beta (E(2)) and testosterone profile during ovarian development. The increase in mRNA of both subunits is probably due to positive feedback of E(2) and testosterone produced by ovarian follicles in response to the GTH contained in chum salmon pituitary homogenate.

Amino Acid Sequence↗
PubMed1996

The chief scientist reports.... Prevalence of psychiatric disorder, cognitive impairment and functional disability among homeless people resident in hostels.

This cross-sectional survey was performed to estimate the prevalence of psychiatric disorder among homeless residents of hostels in Edinburgh and to relate it to functional impairment. Full diagnostic assessments were completed on 136/198 (69%) of the subjects. Thirty-one per cent of subjects (95% CI 25, 42) had significant functional impairment and this was most strongly associated with the presence of functional psychosis and cognitive impairment. Few of the cognitively impaired subjects were in contact with health or social services.

Adult↗