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Biomedical subjects

D Spence

Publications and source records attributed to D Spence.

At least 19 recordsLinked to original sources

Application of business case analysis in planning a province-wide telehealth network in Alberta.

A strategy for implementing telemedicine throughout Alberta was developed. The model was based on a comprehensive evaluation of the four clinical specialties chosen as representative telemedicine services--radiology, psychiatry, emergency services and continuing education. The goals of the telemedicine network were to improve access to health services, provide support for rural health-care providers and increase the efficiency of specialized services. The findings showed that the success factors in a national telemedicine programme depend on a clear organizational structure, with appropriate technical standards and support.

Alberta↗

Lifestyle modifications to prevent and control hypertension. 1. Methods and an overview of the Canadian recommendations. Canadian Hypertension Society, Canadian Coalition for High Blood Pressure Prevention and Control, Laboratory Centre for Disease Control at Health Canada, Heart and Stroke Foundation of Canada.

OBJECTIVE: To provide updated, evidence-based recommendations for health care professionals on lifestyle changes to prevent and control hypertension in otherwise healthy adults (except pregnant women). OPTIONS: For people at risk for hypertension, there are a number of lifestyle options that may avert the condition--maintaining a healthy body weight, moderating consumption of alcohol, exercising, reducing sodium intake, altering intake of calcium, magnesium and potassium, and reducing stress. Following these options will maintain or reduce the risk of hypertension. For people who already have hypertension, the options for controlling the condition are lifestyle modification, antihypertensive medications or a combination of these options; with no treatment, these people remain at risk for the complications of hypertension. OUTCOMES: The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered. EVIDENCE: A MEDLINE search was conducted for the period January 1996 to September 1996 for each of the interventions studied. Reference lists were scanned, experts were polled, and the personal files of the authors were used to identify other studies. All relevant articles were reviewed, classified according to study design and graded according to level of evidence. VALUES: A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension. BENEFITS, HARMS AND COSTS: Lifestyle modification by means of weight loss (or maintenance of healthy body weight), regular exercise and low alcohol consumption will reduce the blood pressure of appropriately selected normotensive and hypertensive people. Sodium restriction and stress management will reduce the blood pressure of appropriately selected hypertensive patients. The side effects of these therapies are few, and the indirect benefits are well known. There are certainly costs associated with lifestyle modification, but they were not measured in the studies reviewed. Supplementing the diet with potassium, calcium and magnesium has not been associated with a clinically important reduction in blood pressure in people consuming a healthy diet. RECOMMENDATIONS: (1) It is recommended that health care professionals determine the body mass index (weight in kilograms/[height in metres]2) and alcohol consumption of all adult patients and assess sodium consumption and stress levels in all hypertensive patients. (2) To reduce blood pressure in the population at large, it is recommended that Canadians attain and maintain a healthy body mass index. For those who choose to drink alcohol intake should be limited to 2 or fewer standard drinks per day (maximum of 14/week for men and 9/week for women). Adults should exercise regularly. (3) To reduce blood pressure in hypertensive patients, individualized therapy is recommended. This therapy should emphasize weight loss for overweight patients, abstinence from or moderation in alcohol intake, regular exercise, restriction of sodium intake and, in appropriate circumstances, individualized cognitive behaviour modification to reduce the negative effects of stress. VALIDATION: The recommendations were reviewed by all of the sponsoring organizations and by participants in a satellite symposium of the fourth international Conference on Preventive Cardiology. They are similar to those of the World Hypertension League and the Joint National committee, with the exception of the recommendations on stress management, which are based on new information. They have not been clinically tested. SPONSORS: The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at health Canada, and the Heart and Stroke Foundation of Canada.

Adult↗

Serum metabolism of bradykinin and des-Arg9-bradykinin in patients with angiotensin-converting enzyme inhibitor-associated angioedema.

Angioedema (AE) associated with angiotensin-converting enzyme inhibitors (ACEi) is a rare, but potentially life-threatening adverse reaction. Several studies have suggested that bradykinin (BK) is responsible for ACEi-induced AE, but the mechanism remains unclear. We investigated the metabolism of BK and des-Arg9-BK in the serum of 20 patients with a history of ACEi-associated AE and 21 control (C) subjects. Synthetic BK was incubated with the sera for various periods of time and residual BK and generated des-Arg9-BK were quantified by specific and sensitive enzyme immunoassays. No significant difference of half-life (t1/2) of both BK and des-Arg9-BK could be measured between C subjects and patients with AE (AE) in absence of ACEi. However, an analysis according to the prolonged (+) or not (-) t1/2 of des-Arg9-BK allowed a new stratification of C subjects and AE patients in four subgroups. The preincubation of sera with enalaprilat at a concentration inhibiting ACE significantly prevented the rapid degradation of BK and des-Arg9-BK in these four subgroups. In presence of ACEi, a subgroup (50%) of AE patients (AE + ) had a particularly significant rise of the t1/2 of des-Arg9-BK. Once ACE was inhibited, the concentration or the nature of the ACEi had no significant effect on the t1/2 of des-Arg9-BK. However, a test dilution of AE + sera with a control (C) serum showed that an enzyme defect rather than a circulating inhibitor could be responsible for the abnormal metabolism of des-Arg9-BK when ACE is inhibited. In conclusion, half of the patients with ACEi-associated AE present in serum had an enzyme defect involved in the des-Arg9-BK metabolism leading to its accumulation. The B1 agonist could be responsible, at least in part, for the local inflammatory reaction associated with the AE.

Adult↗

Candidemia in cancer patients: a prospective, multicenter surveillance study by the Invasive Fungal Infection Group (IFIG) of the European Organization for Research and Treatment of Cancer (EORTC).

In a surveillance study of candidemia in cancer patients that was conducted by the European Organization for Research and Treatment of Cancer, 249 episodes were noted; Candida albicans was isolated in 70% (63) of the 90 cases involving patients with solid tumors (tumor patients) and in 36% (58) of the 159 involving those with hematologic disease (hematology patients). Neutropenia in tumor patients and acute leukemia and antifungal prophylaxis in hematology patients were significantly associated with non-albicans candidemia in a multivariate analysis. Overall 30-day mortality was 39% (97 of 249). In a univariate analysis, Candida glabrata was associated with the highest mortality rate (odds ratio, 2.66). Two multivariate analyses showed that mortality was associated with older age and severity of the underlying disease. Among hematology patients, additional factors associated with mortality were allogeneic bone marrow transplantation, septic shock, and lack of antifungal prophylaxis.

Adult↗

Production and evaluation of guidelines for the management of inflammatory bowel disease: the Leicester experience.

Consensus guidelines for the management of patients with inflammatory bowel disease were produced by gastroenterologists, gastrointestinal surgeons and a cross-section of general practitioners (GPs) from Leicestershire in order to develop a seamless pattern of care with a common approach to diagnosis and treatment. It was hoped that the guidelines would encourage a movement towards care in the community for many patients with stable disease and so speed up new consultation rates. The study then assessed the impact of these guidelines on the referral letters of GPs to hospital consultants, the prediction of disease and adherence to them on re-referring patients after discharge. The guidelines were distributed to all 487 GPs in the Leicester Health Authority area and the gastroenterology teams within the hospitals. The value of the guidelines was assessed by an audit of referral letters, the length of time from referral letter to out-patient appointment, both before and after the launch of the guidelines, adherence to the guidelines on re-referral, and monitoring the outcome of the discharged patients. Whilst the guidelines may have helped GPs to manage stable patients in the community, the content of referral letters and the diagnostic abilities of GPs were not seen to improve since the launch of the guidelines. However, only 5% of stable patients who were discharged from one clinic were re-referred for inflammatory bowel disease.

Attitude↗

The international database of self-recorded blood pressures in normotensive and untreated hypertensive subjects.

OBJECTIVES: To pool data from individual subjects in an attempt to determine an operational threshold for making clinical decisions based on the self-recorded blood pressure (SRBP) and to examine how many hypertensive subjects, diagnosed by conventional blood pressure (CBP) measurement, would have a self-recorded blood pressure within the normotensive range if the proposed thresholds were applied. DATA SOURCES: Thirteen research groups studied 4668 untreated subjects. RESULTS: In total 2401 subjects were normotensive, 494 were borderline hypertensive and 1773 were definitely hypertensive. Hypertension had been diagnosed from the mean of 1-6 (median 3) CBP measurements obtained during 1-3 (median 1) visits. The reference values for SRBP measurements determined from the 95th percentiles of the distributions for normotensive subjects were 137 mmHg systolic and 85 mmHg diastolic. Of the subjects with systolic hypertension, 16% had systolic SRBP </= 137 mmHg. Similarly, 25% of those with diastolic hypertension had diastolic SRBP </= 85 mmHg. The probability that hypertensive subjects had SRBP below these thresholds was 34% (diastolic) to 62% (systolic) greater for women than it was for men, was 2-3 times greater if fewer than three CBP measurements had been averaged for establishing the diagnosis of hypertension, and increased by 50% (diastolic) to 126% (systolic) when SRBP had been measured on more than 3 days. In contrast, for each 10 mmHg increment in systolic CBP, this probability decreased by 35% for systolic SRBP and by 11% for diastolic SRBP; for each 5 mmHg increment in diastolic CBP it decreased by 36% for diastolic SRBP. In addition, for systolic blood pressure, the probability decreased by 31% for each 10-year increment in age. CONCLUSIONS: Until the relationship between SRBP and the incidence of cardiovascular morbidity and mortality has been clarified further by prospective studies, a mean self-recorded blood pressure above 137 mmHg systolic or 85 mmHg diastolic may be considered hypertensive. Among the hypertensive patients 16-31% had SRBP below these thresholds, but this proportion decreased if the hypertensive subjects had higher CBP.

Adolescent↗

Improving the outcome of bone marrow transplantation by using CD52 monoclonal antibodies to prevent graft-versus-host disease and graft rejection.

Graft-versus-host disease (GVHD) is a major cause of mortality and morbidity after allogeneic bone marrow transplantation, but can be avoided by removing T lymphocytes from the donor bone marrow. However, T-cell depletion increases the risk of graft rejection. This study examined the use of CD52 monoclonal antibodies to eliminate T cells from both donor marrow and recipient to prevent both GVHD and rejection. Seventy patients receiving HLA-identical sibling transplants for acute myelogenous leukemia (AML) in first remission were studied. An IgM (CAMPATH-1M) was used for in vitro depletion of the graft and an IgG (CAMPATH-1G) for in vivo depletion of the recipient before graft infusion. No posttransplant immunosuppression was given. Results were compared with two control groups: (1) 50 patients who received bone marrow depleted with CAMPATH-1M, but no CAMPATH-1G in vivo; and (2) 459 patients reported to the International Bone Marrow Transplant Registry (IBMTR) who received nondepleted grafts and conventional GVHD prophylaxis with cyclosporin A (CyA) and methotrexate (MTX). The incidence of acute GVHD was 4% in the treatment group compared with 35% in the CyA/MTX group (P <.001). Chronic GVHD was also exceptionally low in the treatment group (3% v 36%; P <.001). The problem of graft rejection, which had been frequent in the historic CAMPATH-1M group (31%), was largely overcome in the treatment group (6%). Thus, transplant-related mortality of the treatment group (15% at 5 years) was lower than for the CyA/MTX group (26%; P =.04). There was little difference in the risk of leukemia relapse between the treatment group (30% at 5 years) and the CyA/MTX group (29%). Survival of the treatment group at 6 months was better than the CyA/MTX group (92% v 78%), although at 5 years the difference was not significant (62% v 58%) and neither was the difference in leukemia-free survival (60% v 52%). We conclude that T-cell depletion is a useful strategy to prevent GVHD, provided that measures are taken to ensure engraftment. Using CAMPATH-1G to deplete residual host lymphocytes is a simple and practical method to do this. At least in AML, the beneficial reduction in GVHD can be achieved without an increased risk of relapse.

Alemtuzumab↗

An EORTC multicentre prospective survey of invasive aspergillosis in haematological patients: diagnosis and therapeutic outcome. EORTC Invasive Fungal Infections Cooperative Group.

OBJECTIVES: The EORTC Invasive Fungal Infections Cooperative Group (IFICG) conducted a prospective survey by questionnaire of all cases of invasive aspergillosis (IA) in cancer patients to ascertain current diagnostic and therapeutic approaches. METHODS: All members of the IFICG were asked prospectively to complete a detailed questionnaire for each IA case identified in their institution over a 12-month period. RESULTS: One hundred and thirty questionnaires were returned. All cases were independently evaluated (DWD & JC) and 123 were eligible. Cases came from 20 hospitals in eight countries and the number of cases per institution varied from 1-21. Acute myeloid leukaemia (AML) (60, 49%), acute lymphoblastic leukaemia (ALL) (21, 17%) and lymphoma (11, 9%) were the most frequent underlying diseases, and 16 (12%) patients had received an allogeneic bone marrow transplant. Pulmonary involvement was present in 87%, infection of sinuses/nose in 16% and brain in 8%. The chest radiograph was initially normal in 9% of those with primary pulmonary disease. The diagnosis was confirmed in 50%, probable in 31% and possible in 19%. The evidence for IA was on the basis of clinical and radiological features alone in 28%, with culture or histology in another 31% and 9%, respectively, and with both culture and histology in 29%. In three (2%) patients with diagnosis was based on culture or histology alone. Treatment was given to 120 patients (98%)-amphotericin B 75%, lipid-associated amphotericin B 36%, itraconazole 40%, flucytosine 12%, growth factors 33%, lobectomy 5%. At 3 months after diagnosis or first suspicion of IA, 44 (36%) patients were alive and 79 (64%) dead. Outcome was best in those with AML (30% death and 46% with a complete antifungal response or cure). Growth factors (mostly granulocyte colony stimulating factor) appeared not to influence outcome (P = 0.99). CONCLUSION: IA remains a considerable diagnostic and therapeutic challenge. No single diagnostic procedure was universally successful and a multifaceted approach including surgery is necessary. There was no discernable difference in outcome between initial therapy with amphotericin B, itraconazole or lipid-associated amphotericin B, although numbers are limited and the study was retrospective.

Adolescent↗

An EORTC international multicenter randomized trial (EORTC number 19923) comparing two dosages of liposomal amphotericin B for treatment of invasive aspergillosis.

This is the first completed prospective randomized clinical efficacy trial of antifungals in the treatment of invasive aspergillosis (IA) and the first to compare the clinical efficacy of two dosages of liposomal amphotericin B (L-AmB) for IA in neutropenic patients with cancer or those undergoing bone marrow transplantation. Eighty-seven of 120 patients were eligible and evaluable. Clinical responses were documented for 26 (64%) of 41 patients receiving 1 mg/(kg.d) (L-AmB-1) and 22 (48%) of 46 receiving 4 mg/(kg.d) (L-AmB-4). Radiologic response rates were similar: 24 (58%) of the L-AmB-1 recipients and 24(52%) of the L-AmB-4 recipients. The six-month survival rates were 43% (L-AmB-1) and 37% (L-AmB-4). These differences were not significant. The numbers of deaths directly due to IA at 6 months were similar: 9 (22%) of 41 L-AmB-1 recipients and 9 (20%) of 46 L-AmB-4 recipients. No other variable independently influenced survival, apart from central nervous system IA. L-AmB is effective in treating approximately 50%-60% of patients who have IA. A 1-mg/(kg.d) dosage is as effective as a 4-mg/(kg.d) dosage, and no advantages to use of the higher, more expensive, dosage has been observed.

Adult↗

Pharmacokinetics of oral fluconazole when used for prophylaxis in bone marrow transplant recipients.

The pharmacokinetics of fluconazole was investigated in 20 bone marrow transplant patients following oral administration of 200 mg of this drug. Blood samples were collected from each patient at different time intervals within 48 h after the first dose, and fluconazole was measured in plasma by high-performance liquid chromatography with UV detection. Urine was collected from 14 of these patients and analyzed similarly. The plasma concentration-time data exhibited the characteristics of the one-compartment model with first-order absorption quite well. The means +/- standard deviations of half-lives for absorption and elimination, peak concentration, time to peak, mean residence time, apparent volumes of distribution, area under the curve, and apparent oral clearance observed in these patients were 2.84 +/- 1.34 h, 19.94 +/- 18.7 h, 4.45 +/- 1.86 microg/ml, 8.34 +/- 5.97 h, 39.57 +/- 20.5 h, 0.874 +/- 0.48 liter/kg, 156.0 +/- 60.6 microg x h/ml, and 0.0256 +/- 0.0138 liter/h x kg, respectively. The amount of fluconazole excreted in urine in 24 h was 67.1 +/- 83 mg, which represents 33.55% +/- 41.6% of the dose administered. Patients who developed hemorrhagic cystitis excreted significantly (P < or = 0.0094) more fluconazole in 24 h than did those who did not.

Administration, Oral↗

Surface integrity of composite inlays following ultrasonic vibration.

PURPOSE: To assess the effect of ultrasonic vibration on the surface integrity of a resin composite inlay. MATERIALS AND METHODS: Ultrasonic vibration in the form of a scaling tip oriented either parallel or perpendicular to the surface was applied to 2 mm thick, 10 mm wide composite discs and the experiment was repeated with the probe oriented perpendicular using composite or rubber shields. The indentations produced were measured using a form Talysurf profilometer. The surfaces of the discs were also observed using scanning electron microscopy. Five discs were used for each experiment. RESULTS: Both parallel and perpendicular orientations produced an indentation with a scattering of composite debris. A significant increase in the depth of indentation occurred if the vibrations of the ultrasonic scaler were oriented parallel to the composite surface (Two sample t- test, P < 0.01). The presence of a composite shield significantly reduced (Mann-Whitney, P < 0.05) the depth of indentation but produced roughening of the surface with impaction of material from the shield onto the surface. The rubber shield, however, polished the surface significantly smoother than the control specimens (Mann-Whitney, P < 0.05). Microscope slide separation was used to measure the thickness of composite luting agent following vibration with an ultrasonic scaling tip with and without a protective sleeve. There was a significantly thinner film of luting agent when an unsleeved scaler was used (ANOVA, P < 0.001). Although an unguarded tip oriented perpendicular to the surface appears to result in the best energy transfer for a thin layer of composite luting agent, it does, however, create minimal surface damage.

Analysis of Variance↗

Non-invasive ventilation.

Nasal intermittent positive pressure ventilation is an effective treatment for nocturnal hypoventilation secondary to chest wall deformity or respiratory muscle weakness. Physicians should be aware that, in these groups of patients, disabling breathlessness can be alleviated and established cor pulmonale reversed by the technique.

Humans↗

A multicenter randomized double-blind placebo-controlled trial of adjunctive corticosteroids in the treatment of Pneumocystis carinii pneumonia complicating the acquired immune deficiency syndrome.

A multicenter placebo-controlled trial of early short-term high-dose methylprednisolone enrolled 78 patients with moderate to severe Pneumocystis carinii pneumonia (PCP) complicating HIV infection. The mean pressure of oxygen (PO2) at study entry was 55 mm Hg for the 71 patients who had blood gases monitored while breathing room air. Patients were randomized to receive methylprednisolone (40 mg) or placebo parenterally twice daily for 10 days, and the first dose of study medication was given within 24 h of the first dose of antimicrobial therapy for PCP. The primary end point included death, need for mechanical ventilation for > 6 days, or a partial PO2 < 70 mm Hg while breathing room air 10 days after initiation of treatment. There was no statistically significant difference in the primary end point between patients randomized to corticosteroid (CS) or placebo (PL) (p = 0.522; 95% CI = -0.30, 0.16). The incidence of superinfections during therapy or of other HIV-associated infections or malignancies in the 6 months following treatment for PCP was not significantly different between the two groups. More patients randomized to placebo had to discontinue treatment with trimethoprim-sulfamethoxazole because of hypersensitivity than those randomized to corticosteroids (p = 0.039). We conclude that addition of corticosteroids does not significantly affect the outcome of PCP in patients with HIV and a PO2 < 70 mm Hg on room air at presentation but lowers the incidence of hypersensitivity reactions to trimethoprim-sulfamethoxazole.

AIDS-Related Opportunistic Infections↗

Systemic amphotericin B versus fluconazole in the management of antibiotic resistant neutropenic fever--preliminary observations from a pilot, exploratory study.

A pilot exploratory study was undertaken to collect preliminary information relating to safety and overall outcome in using intravenous fluconazole (FLUC) for managing antibiotic resistant neutropenic fever (ARNF), with the objective of assessing feasibility of performing a larger prospective controlled study. Patients who were neutropenic from treatment for leukaemia or bone marrow transplantation, received either fluconazole (FLUC) or amphotericin B (AB). Eight of 16 patients (50%) on FLUC and 21 of 25 patients (84%) on AB defervesced; the mean time to defervescence was 11.0 +/- 10.0 days for FLUC compared to 7.7 +/- 6.3 days for AB, and a similar proportion in each treatment group defervesced within 5 days (50% vs. 52%), respectively. Six of 16 patients (37.5%) on FLUC and three of 25 patients (12%) on AB developed overt invasive fungal disease, including pulmonary aspergillosis (FLUC 4 cases, AB 2 cases) and invasive candidiasis (FLUC 2 cases, AB 0 cases). The mean time to these events was 19.5 +/- 13.4 (FLUC) and 9.0 +/- 3.6 (AB) days. The fungal related mortality rates were higher in the FLUC group: five of 16 patients (31%) vs. two of 25 patients (18%) died respectively; the time to fungal death was 43.2 +/- 18.2 (FLUC) and 25.0 +/- 18.4 (AB) days. This tendency towards a more favourable outcome in patients on AB may have been due to absence of prior fluconazole prophylaxis in patients subsequently receiving IV FLUC. Analysis of a small subgroup of patients who had all received prior prophylaxis with clotrimazole only, indicated that a greater number of patients subsequently receiving IV FLUC died from fungal disease (5/16 vs.0/6, P = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗