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Biomedical subjects

W Rogers

Publications and source records attributed to W Rogers.

At least 19 recordsLinked to original sources
PubMed2006

The maturation of balance in children.

BACKGROUND: Balance function is known to change with age during infancy and childhood. However, the relative contributions of the three primary inputs to position sense are not fully understood. METHODS: In this paper we report the computerised dynamic posturography findings in a group of 60 healthy children from the age of five to 17. RESULTS: The results confirm that there is a progressive improvement in balance function with age. The EquiTest system that was used gave indications of the relative contributions of the three principal contributors to overall balance function and showed that somatosensory function was intact throughout the age range tested and that there are significant increases in vestibular function with age and visual contribution with height. The technique used was found to be reliable and repeatable in this paediatric sample. CONCLUSIONS: It is hoped that a better understanding of the normal age related development of balance will be helpful in dealing with children presenting with disequilibrium and vertigo.

Adolescent↗
PubMed2006

Conflicts of interest in divisions of general practice.

Community-based healthcare organisations manage competing, and often conflicting, priorities. These conflicts can arise from the multiple roles these organisations take up, and from the diverse range of stakeholders to whom they must be responsive. Often such conflicts may be titled conflicts of interest; however, what precisely constitutes such conflicts and what should be done about them is not always clear. Clarity about the duties owed by organisations and the roles they assume can help identify and manage some of these conflicts. Taking divisions of general practice in Australia as an example, this paper sets out to distinguish two main types of conflicts of interest, so that they may be more clearly identified and more effectively managed.

Australia↗
PubMed2005

Comparison of bacteria populations in clean and recycled sand used for bedding in dairy facilities.

Bedding samples were collected twice from commercial dairy free-stall facilities that used recycled sand and clean sand in both the summer and winter. Collection began on the day sand was taken from the pile (d 0) and placed in the free stalls, and continued for 5 to 7 additional days. The number of colonies per gram of bedding of gram-negative bacteria, coliforms, Streptococcus spp., and Klebsiella spp. were estimated for each sand sample as well as amounts of dry and organic matter. Clean sand (CS) and recycled sand (RS) had the same bacterial counts when compared at any sampling time. The mean counts of bacterial populations did vary over the course of the study in both CS and RS. There was a significant increase in bacterial counts from d 0 to d 1 for gram-negative bacteria, coliforms, and Streptococcus spp. in both winter and summer. Counts of gram-negative bacteria, coliforms, Klebsiella spp., and Streptococcus spp. did not differ from d 1 to 7 in the winter. Total counts of gram-negative bacteria did not differ from d 1 to 7 in the summer. On d 1 in the summer, coliform counts were lower than at d 5 to 7, and Klebsiella spp. counts were lower than on d 3 to 7. Streptococcus spp. counts were high on d 1 and were constant through d 7 in both winter and summer trials. The number of coliform and Klebsiella spp. in both CS and RS was below the threshold thought to cause mastitis during the sampling times. The number of Streptococcus spp. was high in both CS and RS during the sampling periods. Other management factors need to be identified to decrease the number of Streptococcus spp. in bedding. Recycled sand had a higher organic matter and lower dry matter compared with CS in winter and summer. The results for this study were obtained from multiple herd comparisons, and herd was a significant effect suggesting that different management systems influence the number and types of bacteria in both CS and RS.

Animals↗
PubMed2001

Relative contribution of mental health and exercise-related pain increment to treadmill test intolerance in patients with chronic low back pain.

STUDY DESIGN: A cross-sectional study. OBJECTIVES: To determine the relative contribution of pain increase and mental health to testing performance during a single bout of exercise in patients with chronic low back pain. BACKGROUND: Controversy exists as to which factors principally limit physical performance in patients with chronic low back pain. Some believe psychological factors limit physical performance, whereas others believe activity-related increases in pain intensity limit performance. METHODS: Seventy-five patients with chronic low back pain reported pain intensity before and after undergoing a maximal, symptom-limited modified treadmill test. Walking time (in minutes) and aerobic fitness were measured. The Short Form 36 Health Survey was administered to all patients. RESULTS: Fifty-four percent of the sample stopped testing because of a significant increase in pain intensity (P = 0.0001). Treadmill performance was lower in patients who stopped because of pain than in those who stopped because of fatigue (P = 0.02). The patients who stopped because of pain were also more likely to have low mental health as assessed by the Short Form 36 Health Survey. Low mental health, however, did not have a statistically significant influence on treadmill performance. CONCLUSION: The data indicate that impairment of physical performance during treadmill testing in patients with chronic low back pain is attributable to testing-induced increase in pain intensity rather than to individual low mental health scores.

Adult↗
PubMed2001

Physical and radiation hybrid mapping of canine chromosome 12, in a region corresponding to human chromosome 6p12-q12.

The positional cloning of the hypocretin receptor 2, the gene for autosomal recessive canine narcolepsy, has led to the development of a physical map spanning a large portion of canine chromosome 12 (CFA12), in a region corresponding to human chromosome 6p12-q13. More than 40 expressed sequence tags (ESTs) were used in homology search experiments, together with chromosome walking, to build both physical and radiation hybrid maps of the CFA12 13-21 region. The resulting map of bacterial artificial chromosome ends, ESTs, and microsatellite markers represents the longest continuous high-density map of the dog genome reported to date. These data further establish the dog as a system for studying disease genes of interest to human populations and highlight feasible approaches for positional cloning of disease genes in organisms where genomic resources are limited.

Animals↗
PubMed2001

Complex HLA-DR and -DQ interactions confer risk of narcolepsy-cataplexy in three ethnic groups.

Human narcolepsy-cataplexy, a sleep disorder associated with a centrally mediated hypocretin (orexin) deficiency, is tightly associated with HLA-DQB1*0602. Few studies have investigated the influence that additional HLA class II alleles have on susceptibility to this disease. In this work, 1,087 control subjects and 420 narcoleptic subjects with cataplexy, from three ethnic groups, were HLA typed, and the effects of HLA-DRB1, -DQA1, and -DQB1 were analyzed. As reported elsewhere, almost all narcoleptic subjects were positive for both HLA-DQA1*0102 and -DQB1*0602. A strong predisposing effect was observed in DQB1*0602 homozygotes, across all ethnic groups. Relative risks for narcolepsy were next calculated for heterozygous DQB1*0602/other HLA class II allelic combinations. Nine HLA class II alleles carried in trans with DQB1*0602 were found to influence disease predisposition. Significantly higher relative risks were observed for heterozygote combinations including DQB1*0301, DQA1*06, DRB1*04, DRB1*08, DRB1*11, and DRB1*12. Three alleles-DQB1*0601, DQB1*0501, and DQA1*01 (non-DQA1*0102)-were found to be protective. The genetic contribution of HLA-DQ to narcolepsy susceptibility was also estimated by use of lambda statistics. Results indicate that complex HLA-DR and -DQ interactions contribute to the genetic predisposition to human narcolepsy but that additional susceptibility loci are also most likely involved. Together with the recent hypocretin discoveries, these findings are consistent with an immunologically mediated destruction of hypocretin-containing cells in human narcolepsy-cataplexy.

Black or African American↗
PubMed2001

Low cerebrospinal fluid hypocretin (Orexin) and altered energy homeostasis in human narcolepsy.

Hypocretins (orexins) are hypothalamic neuropeptides involved in sleep and energy homeostasis. Hypocretin mutations produce narcolepsy in animal models. In humans, narcolepsy is rarely due to hypocretin mutations, but this system is deficient in the cerebrospinal fluid (CSF) and brain of a small number of patients. A recent study also indicates increased body mass index (BMI) in narcolepsy. The sensitivity of low CSF hypocretin was examined in 38 successive narcolepsy-cataplexy cases [36 human leukocyte antigen (HLA)-DQB1*0602-positive] and 34 matched controls (15 controls and 19 neurological patients). BMI and CSF leptin levels were also measured. Hypocretin-1 was measurable (169 to 376 pg/ml) in all controls. Levels were unaffected by freezing/thawing or prolonged storage and did not display any concentration gradient. Hypocretin-1 was dramatically decreased (<100 pg/ml) in 32 of 38 patients (all HLA-positive). Four patients had normal levels (2 HLA-negative). Two HLA-positive patients had high levels (609 and 637 pg/ml). CSF leptin and adjusted BMI were significantly higher in patients versus controls. We conclude that the hypocretin ligand is deficient in most cases of human narcolepsy, providing possible diagnostic applications. Increased BMI and leptin indicate altered energy homeostasis. Sleep and energy metabolism are likely to be functionally connected through the hypocretin system.

Adolescent↗
PubMed2001

Health status assessments using the Veterans SF-12 and SF-36: methods for evaluating otucomes in the Veterans Health Administration.

This article describes a study in which the administration of two health surveys, the Veterans SF-36 and SF-12, by telephone and mail-out was used to assess the differences in the health surveys' costs and scores by mode of administration and determine which mode was cost-efficient. The study employed a crossover design: after 12 unsuccessful attempts to contact patients by telephone, the patients were administered the survey by mail, and after 2 unsuccessful mail-outs, up to three attempts were made to interview the patients by telephone. The analysis of the data showed that mail administration, with or without crossover to telephone, was more cost-efficient than telephone administration, having both lower average total and variable costs per completed questionnaire. Overall, telephone administration was about 30% more expensive that mail administration, primarily due to the cost of labor. The marginal cost of an additional completed Veterans SF-12 or Veterans SF-36 was also substantially lower for mail administration. Mail administration without crossover to telephone administration was the most cost-efficient strategy for administering both the Veterans SF-12 and SF-36. The results of this study strongly suggest the need to consider the mode of administration if questionnaires like the Veterans SF-12 or SF-36 are to be used to assess health outcomes within and across large health care systems.

Costs and Cost Analysis↗
PubMed2001

Advancing health promotion in Australian general practice.

Health promotion activities, while having the potential to prevent disease and decrease the burden of ill health, often play a minor role in the health care offered by general practitioners. There are several identified barriers to the involvement of Australian general practitioners in health promotion. These include structural barriers and barriers within the practice setting, individual practitioner and patient factors, and difficulties in evaluating the outcomes of health promotion activities. This article explores the barriers to the engagement of Australian general practice with health promotion and reviews several recent initiatives that have the potential to increase the health promotion activities of general practitioners. These initiatives act at the level of the individual practitioner, the practice, and in the community. Despite the lack of a coordinated national approach, these strategies form an important development in general practice.

Accreditation↗
PubMed2001

Application of the privacy principles to general practice.

BACKGROUND: There are escalating requirements for general practitioners to comply with recognised privacy principles. With amendments to the Commonwealth Privacy Act (1988) imminent, there is an urgent need to formulate methods for applying these principles to general practice. OBJECTIVE: The article provides an explanation of the origins of the privacy principles and a simple self audit which general practitioners can use to assess the extent to which their usual practices conform with them. DISCUSSION: A careful review of the principles indicates that new measures will be needed before most general practices will be able to approach required standards of conduct. Practical strategies for achieving best practice are discussed and challenges confronting general practices in applying the principles are canvassed. Ethics committees should be used more often to provide independent review of practice policies and proposals to use patient information in new ways. General practitioners can expect increasing scrutiny and debate concerning confidentiality. In order to maintain patient trust in GPs as responsible data custodians, the privacy principles can be seen as a quality improvement tool.

Australia↗
PubMed2001

A guide to undertaking a literature review.

BACKGROUND: The National Information Service of the General Practice Evaluation Program (GPEP) produced publications relating to research undertaken under the auspices of the program with the view to adding value to such research. Two anthologies of literature reviews from GPEP research have been produced, one in 1998 and the other in 2000. A thorough guide to undertaking and writing a literature review was part of the second anthology. This paper is a shortened version of that guide. OBJECTIVE: This paper is designed as an overview for general practitioners who wish to undertake a research project. In this overview the authors describe the reasons researchers undertake a literature review and the steps involved in conducting and writing up a review, including the development of search strategies. DISCUSSION: The literature review described in this paper is a narrative review. This type of review involves performing thorough literature searches, describing how these were done, grouping findings according to themes, critically discussing findings and placing the proposed research in context.

Humans↗
PubMed2000

Deconditioning in patients with chronic low back pain: fact or fiction?

STUDY DESIGN: Prospective case series with historical controls (normative data). OBJECTIVES: To compare aerobic fitness levels in patients with chronic low back pain with those published on a sample of 295 healthy subjects. SUMMARY OF BACKGROUND DATA: Clinical belief holds that patients with chronic low back pain have low fitness levels as a result of inactivity because of pain. Because few studies have investigated the level of aerobic fitness in these patients, however, it remains unclear how fitness levels in patients with chronic low back pain patients compare with those published a sample of the normative population. METHODS: A sample of 50 patients with chronic low back pain with a mean pain duration of 40 months referred to an outpatient pain clinic performed a symptom-limited modified treadmill test. Aerobic fitness levels were determined by indirect calorimetry to measure oxygen consumption (VO2). Predicted maximum oxygen consumption (VO2max) levels were calculated for all subjects. Multiple regression analysis with adjustment for age and sex yielded prediction equations for men and women separately. Ninety-five percent confidence intervals were calculated for predicted mean oxygen consumption (VO2) and the slope of the equations. These were compared to established prediction equations on healthy subjects. RESULTS: Prediction equations for estimated maximum oxygen consumption (VO2max) in patients with chronic low back pain equal those in healthy sedentary men and active women. CONCLUSIONS: Levels of aerobic fitness in patients with chronic low back pain are comparable with those in healthy subjects.

Adult↗
PubMed2000

Aerobic fitness testing in patients with chronic low back pain: which test is best?

STUDY DESIGN: This is a randomized comparison of three exercise tests in a sample of 30 patients with chronic low back pain. OBJECTIVES: To determine, by comparing three exercise tests, which test yields the highest peak and predicted oxygen consumption in a sample of patients with chronic low back pain. SUMMARY OF BACKGROUND DATA: Little is known about the level of aerobic fitness in patients with chronic low back pain, although many rehabilitation programs emphasize aerobic exercise as an important part of their therapy. Measurement of aerobic fitness levels in these patients remains a problem. In healthy individuals, the highest oxygen consumption values come from exercise tests that use the largest muscle groups. For a number of reasons, this may not be true in patients with chronic low back pain. METHODS: In this study, 30 participants with chronic low back pain performed three symptom-limited maximal exercise tests: a treadmill, an upper extremity ergometer, and a bicycle ergometer. The tests were administered in randomized order. Heart rate was continuously monitored and oxygen consumption in terms of mL/kg/minute was measured by indirect calorimetry each 30 seconds. RESULTS: The statistical difference among the tests was highly significant (P < 0.0001). The treadmill test yielded the highest peak and predicted oxygen consumption followed by the bicycle and the upper extremity ergometer test, respectively. CONCLUSIONS: The treadmill test is the best test for measuring aerobic fitness levels in patients with chronic low back pain. It yielded the highest peak oxygen consumption compared with the other tests, coming closest to measuring maximal oxygen consumption.

Adolescent↗
PubMed2000

Depression and health-related quality of life in ethnic minorities seeking care in general medical settings.

BACKGROUND: To examine ethnic groups differences in (a) prevalence of depressive disorders and (b) health related quality of life in fee-for-service and managed care patients (n=21504) seeking care in general medical settings. METHODS: Data are from the Medical Outcomes Study, a multi-site observational study of outpatient practices. The study screened patients of clinicians (family practice, internal medicine, cardiology, diabetology and endocrinology) for four chronic medical conditions; depression, coronary heart disease, hypertension and diabetes. A brief eight-item depression screener followed by the Diagnostic Interview Schedule-Depression Section (DIS) for screener positives identified depressed patients (n=2195). The Short Form Health Survey (SF-36) assessed health-related quality of life. Patient self-report determined ethnicity. RESULTS: Before adjusting for demographic factors, African-Americans and Hispanics had highest rates of depressive symptoms. Asian-Americans had the lowest. After adjusting for demographics (particularly gender and income), we found few statistically significant differences in prevalence or severity of depression. However, among the depressed, Whites were the most, and African-Americans the least likely to report suicidal ideation (p<0. 01), and Hispanics and Whites were more likely to have melancholia (p<0.01). African-Americans reported the poorest quality of life. LIMITATIONS: DSM III criteria (though few changes in DSM IV), and relatively small sample size of Asian-Americans compared to other groups. CONCLUSIONS: Gender and socioeconomic status are more significant factors than ethnicity in determining risk for depressive disorder. However, ethnic differences in symptom presentation, and health-related quality of life could have clinical and social consequences, and merit further study.

Adult↗
PubMed2000

A mutation in a case of early onset narcolepsy and a generalized absence of hypocretin peptides in human narcoleptic brains.

We explored the role of hypocretins in human narcolepsy through histopathology of six narcolepsy brains and mutation screening of Hcrt, Hcrtr1 and Hcrtr2 in 74 patients of various human leukocyte antigen and family history status. One Hcrt mutation, impairing peptide trafficking and processing, was found in a single case with early onset narcolepsy. In situ hybridization of the perifornical area and peptide radioimmunoassays indicated global loss of hypocretins, without gliosis or signs of inflammation in all human cases examined. Although hypocretin loci do not contribute significantly to genetic predisposition, most cases of human narcolepsy are associated with a deficient hypocretin system.

Adult↗
PubMed2000

Handling information. Some ethical issues.

BACKGROUND: General practitioners are increasingly involved in a range of activities which require the use of data from patients' case notes. These activities include audit, evaluation and research. Any use of patient data has the potential to breach patient confidentiality and privacy. However, at present the requirements in terms of obtaining informed consent vary. Research is usually acknowledged as requiring consent, but this is not always the case for audit and evaluation activities. OBJECTIVES: The aim of this paper is to define audit, evaluation and research activities in general practice and to clarify the ethical issues involved in using patient data for these purposes. We argue that the ethical issues raised by accessing patient case notes are similar for all of these activities. DISCUSSION: The ethical obligation to obtain patient consent prior to accessing or using patient information is the same for many general practice audit, evaluation and research activities. However, the avenues for obtaining ethical clearance may be hard to access for GPs. In addition, the special relationship between patients and their GP and the requirements specified by health research ethics committees such as de-identification of case notes create problems for these activities in general practice.

Australia↗
PubMed2000

Handling information ethically. Some strategies for discussion.

BACKGROUND: A lack of consensus currently exists about which uses of patient data require informed consent or review by a human research ethics committee. However, any use of patient data other than for clinical care, requires the consent of the patient. OBJECTIVE: The aim of this paper is to discuss strategies for strengthening current practices regarding the use of patient information in general practice research, evaluation and audit. DISCUSSION: Increasing community discussion and debate with respect to the use of patient data for research and evaluation is a pressing issue. Divisions of general practice are well placed to lead in this debate given the extent of community representation in many divisions' activities. Development of guidelines for use by those undertaking research and evaluation activities in general practice, based upon the Privacy Principles, will ensure a high standard of protection for patients. Community based Human Research Ethics Committees may be an appropriate way of providing education and training as well as a review of general practice research and related activities.

Australia↗