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Biomedical subjects

D Clarke

Publications and source records attributed to D Clarke.

At least 73 records · Page 4Linked to original sources
PubMed2000

What factors contribute to senior psychiatry residents' interest in geriatric psychiatry? a Delphi study.

OBJECTIVE: To generate hypotheses regarding factors that influence senior psychiatric residents, to consider treating geriatric patients in their future practices. METHOD: Using the Delphi technique, designed to generate ideas and consensus, we asked psychiatry residents at the University of Toronto who had completed, or were completing, their geriatric rotation about the factors they thought might influence residents in devoting some of their practice to geriatric patients. Residents then rated the degree of influence of these factors which had been synthesized into a questionnaire. RESULTS: Twenty-six items were rated according to their degree of influence. The most influential item was positive clinical experiences with seniors. This was followed closely by supervisor characteristics such as enthusiasm, role modeling, competence, and mentoring. Interest in and comfort with the medical psychiatric and neuropsychiatric nature of the field were also felt to be influential. CONCLUSIONS: The factors that influence senior psychiatry resident interest in the practice of geriatric psychiatry are primarily educational and result from exposure to the field under optimal educational circumstances (positive clinical experiences and excellent supervisors). The medical and neuropsychiatric nature of the field also likely exerts a unique influence and should be considered in stimulating interest in this population.

Adult↗
PubMed2000

The role of depression severity in the cognitive functioning of elderly subjects with central nervous system disease.

OBJECTIVE: To examine the hypothesis that there is a causal relation between depression and cognitive dysfunction in patients with central nervous system (CNS) disease. DESIGN: Retrospective analysis of a clinical database. SETTING: Tertiary geriatric day hospital. PATIENTS: Sixty-five patients with depression and CNS disease, and 201 patients with depression but without CNS disease. OUTCOME MEASURES: Scores on the Hamilton Depression Rating Scale (Ham-D) and the Mattis Dementia Rating Scale (MDRS). RESULTS: A logistic regression analysis using MDRS status as the dependent variable, and a number of clinical variables as the predictor variables, showed that, in patients with CNS disease, only the Ham-D score predicted MDRS status (R = -0.19, p = 0.02). Ham-D score even more strongly predicted scores on a frontal system subtest of the MDRS (R = -0.262, p = 0.005). Ham-D score did not predict MDRS status in patients without CNS disease. Mean Mini Mental State Examination scores for the group with CNS disease were 25.1 at admission and 26.1 at discharge (p < 0.001). CONCLUSIONS: These findings suggest that depression contributes to frontal cognitive dysfunction in patients with CNS disease.

Aged↗
PubMed2000

Effects of hyperbaric oxygen on ventricular performance, pulmonary blood volume, and systemic and pulmonary vascular resistance.

The cardiovascular effects of hyperbaric (3 atm abs) air, 100% oxygen, and hyperbaric oxygen (HBO2) at 3 atm abs were investigated in 13 pentobarbital-anesthetized dogs. We measured heart rate, arterial pressure, pulmonary artery pressure, right atrial pressure, left and right ventricular pressure, and cardiac output. From these we determined end diastolic pressure, +/-maximal dp/dt, maximal (dp/p), end systolic elastance, cardiac work, and systemic (SVR) and pulmonary vascular resistance (PVR). Pulmonary blood volume was obtained from the mean transit time of ascorbic acid. The significant results with HBO2 were a decrease in heart rate, cardiac output, and cardiac work. All left ventricular performance indices decreased, without a change in preload or afterload. In contrast, only right ventricular -dp/dt decreased. SVR increased but PVR did not change; 100% O2 produced similar but less pronounced responses. Hyperbaric air had only mild effects. Pulmonary blood volume and lung wet/dry ratio did not change. Our data suggest that HBO2 may act by a differential effect on the autonomic innervation of the right and left ventricles. The resultant ventricular imbalance may be of clinical importance in the mechanism of pulmonary edema in patients in congestive heart failure undergoing hyperbaric therapy.

Animals↗
PubMed2000

Maintenance as a corporate strategy.

As we move towards the 21st century, those Manufacturing Industries that survive, will have changed their "efficiency" focus away from the conventional wisdom of "efficient individual tasks", to focus on the "effectiveness of a total manufacturing process". This seemingly insignificant change of emphasis, (from task to process) must include "the integration of process plant maintenance into the production process". Manufacturing companies, which do not include an effective plant maintenance strategy into their business strategy, will not survive the business environment of the 21st Century.

Australia↗
PubMed2000

Maintenance as a corporate strategy.

As we move towards the 21st century, those Manufacturing Industries that survive, will have changed their "efficiency" focus away from the conventional wisdom of "efficient individual tasks", to focus on the "effectiveness of a total manufacturing process". This seemingly insignificant change of emphasis, (from task to process) must include "the integration of process plant maintenance into the production process". Manufacturing companies, which do not include an effective plant maintenance strategy into their business strategy, will not survive the business environment of the 21st Century.

Australia↗
PubMed1999

Evidence for triacylglycerol synthesis in the lumen of microsomes via a lipolysis-esterification pathway involving carnitine acyltransferases.

In this study a pathway for the synthesis of triacylglycerol (TAG) within the lumen of the endoplasmic reticulum has been identified, using microsomes that had been preconditioned by depleting their endogenous substrates and then fusing them with biotinylated phosphatidylserine liposomes containing CoASH and Mg(2+). Incubating these fused microsomes with tri[(3)H] oleoylglycerol and [(14)C]oleoyl-CoA yielded microsome-associated triacylglycerol, which resisted extensive washing and had a [(3)H]:[(14)C] ratio close to 2:1. The data suggest that the precursor tri[(3)H]oleoylglycerol was hydrolyzed by microsomal lipase to membrane-bound di[(3)H]oleoylglycerol and subsequently re-esterified with luminal [(14)C]oleoyl-CoA. The accumulation of TAG within the microsomes, even when overt diacylglycerol acyltransferase (DGAT I) was inactive, is consistent with the existence of a latent diacylglycerol acyltransferase (DGAT II) within the microsomal lumen. Moreover, because luminal synthesis of TAG was carnitine-dependent and markedly reduced by glybenclamide, a potent carnitine acyltransferase inhibitor, microsomal carnitine acyltransferase appears to be essential for trafficking the [(14)C]oleoyl-CoA into the microsomal lumen for subsequent incorporation into newly synthesized TAG. This study thus provides the first direct demonstration of an enzymatic process leading to the synthesis of luminal triacylglycerol, which is a major component of very low density lipoproteins.

Acyl Coenzyme A↗
PubMed1999

How well do we monitor patient satisfaction? Problems with the nation-wide patient survey.

AIM: To outline and assess the accuracy and usefulness of the quarterly nation-wide patient survey of all New Zealand hospitals. METHOD: Data generated by an improved patient survey at South Auckland Health (SAH) was used to examine some of the problems and issues pertaining to this survey: i.e. the format of the questionnaire; unintended consequences of the specific methodology employed and the usefulness of the obtained information. RESULTS: Evidence is provided to show that the inpatient sample is not representative of the SAH patient population and that patients across different socio-demographic groups have different satisfaction rates. Additional research projects undertaken by the authors at SAH suggest that different methods of completing the questionnaire can significantly influence the results. CONCLUSION: The nation-wide patient survey is in need of revision, if it is to be used as an effective management tool within hospitals and for the sector as a whole.

Adolescent↗
PubMed1999

System memory in violent incidents: evidence from patterns of reoccurrence.

For 20% of a sample of 1,078 violent incidents reported in British bars and pubs, another incident was reported at the same premises within 6 months. Log-survival analysis revealed nonrandom sequences that demonstrate a system memory effect separate from any biases involving particular venues. The rate of reoccurrence was not constant during the 6 months following incidents but was significantly higher for Weeks 1-4, approximated to the mean value for Weeks 5-12, and declined for Weeks 13-26. Reoccurrence was particularly likely in the first 3-4 days after an incident. Risk of reoccurrence was further increased for incidents that involved either threats or the exit and return of the assailants within that original incident. Results support the view that "violence breeds violence" and demonstrate the need for increased staff vigilance for up to 12 weeks following a violent incident, and particularly during the first few days and weeks.

Alcoholic Intoxication↗
PubMed1999

Stent implantation reduces restenosis in patients with suboptimal results following coronary angioplasty.

BACKGROUND: Primary intracoronary stenting reduces the rate of restenosis when compared with balloon angioplasty (PTCA) in selected patients. The strategy of PTCA followed by provisional stent placement for suboptimal PTCA results may be preferable to universal stenting but has not yet been tested in a randomized trial. METHODS: An attempt was made to obtain an optimal result with PTCA alone in 143 patients. Stenting was required in 50 patients (35%) for significant coronary dissection or PTCA failure. In the remaining 93 patients, the angiographic result was assessed immediately using on-line quantitative coronary angiography and classified as either optimal (<15% residual stenosis) or suboptimal (>/=15% residual stenosis). Sixteen patients (11%) had an optimal result from PTCA. The remaining 77 (54%) patients had a suboptimal result and were immediately randomized either to no further treatment or to the placement of a stent. The primary end-point was the rate of restenosis (>50% stenosis), assessed by quantitative coronary angiography, at 6 months. RESULTS: Angiographic follow-up was completed in 132 patients. Restenosis occurred in 53 (36,69)% of patients with a suboptimal result randomized to PTCA alone compared with 24 (12,41)% of patients randomized to stent (P=0.023). There was no significant difference in minimal luminal diameter at follow-up between the randomized groups. The rate of restenosis was 14 (2,43)% in patients with an optimal PTCA result and 14 (5,28)% in those that required stenting. CONCLUSIONS: Optimal angiographic results following conventional PTCA are rare and the restenosis rate following suboptimal results is high. The strategy of stenting suboptimal results is associated with a significant reduction in the rate of stenosis.

Angioplasty, Balloon, Coronary↗
PubMed1999

The management of epilepsy in a hospital for people with a learning disability.

The study examined changes in the use of antiepileptic drugs (AEDs) in a large hospital for people with a learning disability over a 2 year period, the use of investigations, and the presence of medication side-effects. The surveys were carried out in 1993 and 1995/6. In 1993, 27% of patients were being treated for epilepsy and in 1995/6, 30.1%. Ninety percent and 82.4% of patients, respectively, were receiving one or two AEDs. In the second survey there were fewer prescriptions for phenobarbitone (5.8% vs. 12.5%) and an increase in the use of lamotrigine (21.6% vs. 5%), gabapentin (5.8% vs. 0) and vigabatrin (3.9% vs. 2.5% in 1993). Side-effects were recorded in 6 (11.8%) patients. Seven (21.2%) patients receiving carbamazepine were found to have hyponatraemia. Of the 54 electroencephalograms (EEGs) requested, 41 (76%) were reported as abnormal. Six CT brain scans had been conducted, of which five were abnormal. People receiving antipsychotic drugs had fewer seizures than average.

Acetates↗
PubMed1999

Lessons from the other side: what can we learn from the private sector?

Business has reacted in an impressive manner to increasing globalisation, short-term stock market pressure for performance, emerging industries and new technologies. While the private sector has become increasingly competitive, the public sector has not adopted this commercial rigour. Funding pressures on health services will continue, as will increasing consumer and staff demands and the blurring of public and private health care provision. As a result, there are lessons and techniques the public and private health sectors should learn from each other. I have drawn the issues that follow from my experience in the steel and food industries.

Delivery of Health Care↗
PubMed1999

Reading numbers aloud: a measure of the limiting effect of breathlessness in patients with cancer.

BACKGROUND: Progress in the treatment of breathlessness at rest or on minimum exertion in patients with cancer requires a practical and valid method of measuring symptoms. A study was undertaken to explore the practicality, repeatability, and sensitivity of reading numbers as a form of exercise test in this group of patients. METHODS: Thirty patients with cancer and 30 age matched healthy subjects read numbers aloud as quickly and clearly as they could for 60 seconds. After five readings the maximum number of numbers read and the number read per breath was noted. This procedure was carried out twice in one day and one week later to assess within and between day repeatability. The sensitivity of the test was assessed by making measurements in 13 patients with cancer before and after drainage of their pleural effusion. RESULTS: The concept was easily understood by all subjects. Twelve patients were unable to complete five readings in all tests due to tiredness. Compared with control subjects patients read fewer numbers in the three tests (87-89% of control) and fewer numbers per breath (59-60% of control). Repeatability was good both within and between days. After drainage of their effusion all patients were less breathless and there was an increase in both the maximum number of numbers read (23%) and the number read per breath (60%). CONCLUSIONS: The number of numbers read and the number read per breath over 60 seconds was practical, easy to carry out, showed good repeatability within and between days and was sensitive to the improvement seen following drainage of a pleural effusion. It may be a useful measure of the limiting effect of breathlessness in this group of patients.

Aged↗
PubMed1999

Late-life depression as a possible predictor of dementia: cross-sectional and short-term follow-up results.

The authors explored cognitive functioning of a group of elderly subjects with depression. The group as a whole, and, in particular, the late-onset group (LOD), demonstrated cognitive impairment on the Mattis Dementia Rating Scale (MDRS). Subgroup differences were significant at P=0.004. This between-group difference was not seen when age and level of education were controlled. In the LOD group, 47.5% (vs. 31.5% of the early-onset group [P=0.025]), scored below the cutoff for dementia. Age-at-onset status in a logistic regression model predicted MDRS category, and treatment of the depression had little effect on cognition. Results support the hypothesis that late-life depression, particularly LOD, is associated with cognitive impairment that may represent early AD.

Age Factors↗
PubMed1999

Appendix: education and information resources in hyperbaric medicine.

A comprehensive listing of hyperbaric medicine resources is provided. These resources serve the educational and information needs of those who wish to enter this medical specialty, as well as those who practice it. A selected hyperbaric specific bibliography is included, as is the methodology to stay current with the scientific and technological advances of this field.

Humans↗
PubMed1999

The specialist registrar puzzle: do all the pieces fit?

The review of medical training by the Working Party headed by Sir Kenneth Calman culminated in the introduction of the specialist registrar (SpR) training grade. Surgery and Radiology were the vanguard specialties, with the SpR post being introduced in December 1995.

Consumer Behavior↗
PubMed1999

The SynerGraft valve: a new acellular (nonglutaraldehyde-fixed) tissue heart valve for autologous recellularization first experimental studies before clinical implantation.

The durability of current bioprosthetic heart valves is diminished by glutaraldehyde-associated leaflet calcification or by the associated absence of a cellular component capable of repair of wear-related damage. As a novel tissue engineering approach to improving replacement heart valve durability, we have developed a decellularization process to replace the use of cross-linking to limit xenograft antigenicity. The effectiveness of this process was assessed in a weanling sheep right ventricular outflow tract reconstruction model where valve function, calcification, and recellularization were examined. Porcine aortic valves were decellularized by a process designed to remove all histologically demonstrable leaflet cells. Stentless, bioprosthetic valves were fabricated from acellular tissues, cryopreserved, sterilized, and then implanted as pulmonary valve replacements in 4- to 6-month old female Suffolk sheep. Sheep aortic valves were implanted as allograft control subjects. After 150 days, the grafts were explanted and assessed histologically and by atomic absorption spectrophotometry for calcium content. All valves were hemodynamically functional at explant. Histological examination showed intact leaflets with in-growth of host fibroblastoid cells in all explanted porcine valves and no evidence of calcification. Porcine leaflet calcium content was unchanged over the duration of the implant (1.0+/-1.2 vs 1.5+/-1.8 mg/g dry weight, P = ns). Decellularization can stabilize xenogenic heart valves. Lack of calcification of acellular aortic leaflets suggests that prolonged durability of such valves is attainable without the use of cross-linking agents. The repopulation of the leaflet matrix offers additional promise of durability based on revitalization of the graft in vivo.

Animals↗