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D Spence

Publications and source records attributed to D Spence.

At least 19 recordsLinked to original sources
PubMed2003

A randomized trial investigating an iron-rich natural mineral water as a prophylaxis against iron deficiency in pregnancy.

Spatone Iron-Plus is a naturally occurring mineral water from Trefriw Wells Spa in Conwy County, North Wales, UK. It contains approximately 0.20 mg of iron per millilitre as ferrous sulphate and has been shown to provide iron in a highly bio-available form. A 24 ml sachet contains approximately 5 mg of iron. Iron deficiency is common in the obstetric population. However, compliance with traditional iron supplements is poor because of gastrointestinal side-effects. We designed a randomized, double-blind, placebo-controlled trial. A total of 102 low-risk antenatal patients, who were noncompliant with routinely prescribed ferrous sulphate tablets, were randomized to receive 48 ml of Spatone water or placebo. The study was conducted between 22 and 28 weeks gestation. Primary outcome measures were compliance, gastrointestinal side-effects and changes in ferritin levels during the trial period. Compliance in the intervention group was 57% compared with 67% in the control group, P = 0.22. Dyspepsia scores, as determined by a recognized and well-validated questionnaire, did not differ between the two groups. During the trial period, mean ferritin levels fell by 24% in the Spatone Iron-Plus group compared with a mean fall of 51% in ferritin levels among the control group, P = 0.016.

Adult↗
PubMed2001

Effect of therapeutic ionizing radiation on the human brain.

We test a hypothesis that fractionated radiation therapy within a therapeutic dose range is associated with a dose-related change in normal brain, detectable by quantitative magnetic resonance imaging. A total of 33 patients were examined by quantitative magnetic resonance imaging to measure brain tissue spin-lattice relaxation time (T1) before treatment, and at various times during and after radiation therapy. A T1 map was generated at each time point, and radiation therapy isodose contours were superimposed on the corresponding segmented T1 map. Changes in white matter and gray matter T1 were analyzed as a function of radiation therapy dose and time since treatment, controlling for patient age and tumor site. In white matter, a dose level of more than 20 Gy was associated with a dose-dependent decrease in T1 over time, which became significant 6 months after treatment. There was no significant change in T1 of gray matter over time, at radiation therapy doses of less than 60 Gy. However, GM in close proximity to the tumor had a lower T1 before therapy. Our results represent the first radiation dose-response data derived from pediatric brain in vivo. These findings confirm that white matter is more vulnerable to radiation-induced change than is gray matter, and suggest that T1 mapping is sensitive to radiation-related changes over a broad dose range (20 to 60 Gy). Human white matter T1 is not sensitive to radiation therapy of less than 20 Gy, and gray matter T1 is unchanged over the dose range used to treat human brain tumor. The reduction of gray matter T1 near the tumor could result from compression of cortical parenchyma near the growing tumor mass, or from tumor cell invasion directly into the parenchyma. If brain T1 is a surrogate for radiation effect, reducing the volume of normal white matter receiving more than 20 Gy could be an important treatment planning goal.

Adolescent↗
PubMed2001

Chemiluminescence detection of ATP release from red blood cells upon passage through microbore tubing.

A novel approach for the determination of adenosine triphosphate (ATP) released from red blood cells (RBCs) after passage through microbore capillaries is described. ATP is often released from RBCs in vessels and has been linked to the production of nitric oxide, a known vasodilator. The system described here uses a syringe pump to deliver microliter flow rates (5-15 microl min(-1)) of reagent and sample through fused silica capillary tubing of varying dimensions (25-75 microm) to a photomultiplier tube. The released ATP is characterized by the detection of chemiluminescent emission from the luciferin-luciferase reaction. The amount of ATP released is directly proportional to the number of RBCs injected into the system. Results also suggest that the amount of released ATP decreases from 6.9 microM to 1.4 microM as the tubing diameter is increased from 25 microm to 75 microm. An investigation of capillary lengths ranging from 15 to 35 cm resulted in ATP concentrations of 1.5 microM to 2.4 microM being released. Results also indicate that increases in flow rate also induce increased amounts of ATP release. These results are consistent with those of previous systems attempting to model the physiological release of ATP from red blood cells.

Adenosine Triphosphate↗
PubMed2001

An in-use evaluation of an alcohol-based pre-surgical hand disinfectant.

OBJECTIVE: To determine whether alcohol hand disinfection is an effective alternative to traditional agents for the pre-surgical scrub. DESIGN: A prospective clinical trial of a 70% isopropanol pre-surgical hand disinfectant. SETTING: The operating room suites at two hospital sites in British Columbia. METHODS: Cases were selected to evaluate both short and longer procedures. The hand disinfectant was compared to agents in current use as surgical scrubs (4% chlorhexidine and 7.5% povidone-iodine). Surgical technique and glove use were not modified. Pre- and postoperative fingertip impression and "glove-juice" cultures were used to determine microbial burden, and hands were evaluated for skin integrity. RESULTS: There was no statistical difference between the microbial hand counts following use of the alcohol-based product or the current agents, for cases less than 2 hours' duration. Comparison of longer surgical cases revealed significantly better pre- and postoperative culture results with the alcohol hand rinse, but analysis of matched pairs showed no significant difference in microbial counts. The alcohol hand rinse was equivalent to the operative scrub in terms of skin integrity and user acceptability. CONCLUSION: An alcohol hand rinse was equivalently effective in reducing microbial hand counts as the traditional pre-surgical scrub, both immediately after hand disinfection and at the end of the surgical procedure.

2-Propanol↗
PubMed2000

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗