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Biomedical subjects

J Cooper

Publications and source records attributed to J Cooper.

At least 37 records · Page 2Linked to original sources
PubMed2004

A combination of two common thrombomodulin gene variants (-1208-1209TTdelTT and A455V) influence risk of coronary heart disease: a prospective study in men.

In a previous case control study of myocardial infarction (MI), we identified risk associated with the combination of two variants in the thrombomodulin (TM) gene (-1208-1209TTdelTT and A455V) and an interaction with increased body mass index (BMI). The rare alleles at these two common variant sites in the TM gene occur in most individuals on the same allele (V/delTT) and are in strong linkage disequilibrium (Delta=0.67, P <0.0005). We have extended these findings in a prospective study of 2700 UK middle age men; the second Northwick Park Heart Study (NPHSII), in which 227 coronary heart disease (CHD) events have been reported to date. Risk was analysed by tertile of BMI, systolic blood pressure (SBP) and triglyceride. The strongest risk for the V/delTT haplotype was in the mid- and top-tertile of triglyceride; RR 1.95 (CI 1.12-3.40) and 1.77 (CI 1.02-3.09), respectively, compared to non-carriers in the lowest tertile (after adjusting for age, practice, smoking, SBP, BMI; interaction P=0.016). No significant risk was identified for increased triglyceride levels in those with the common TM haplotype. There was a suggestion for greater inflammatory response (C-reactive protein levels, CRP) in those with V/delTT compared to those with the common allele, as triglyceride levels increased. Overall, these findings may suggest that the common TM allele confers protection against the adverse CHD effect of either plasma triglyceride-containing lipoproteins, or the underlying atherosclerotic mechanism of the metabolic syndrome, and that this process is defective in carriers of V/delTT.

Coronary Disease↗
PubMed2004

The Midlands Trial of Empirical Amiodarone versus Electrophysiology-guided Interventions and Implantable Cardioverter-defibrillators (MAVERIC): a multi-centre prospective randomised clinical trial on the secondary prevention of sudden cardiac death.

AIMS: MAVERIC was a randomised clinical trial designed to test the possibility of prospectively identifying patients who would benefit most from the implantable cardioverter-defibrillator (ICD) by electrophysiology (EP) study in the context of secondary prevention of sudden cardiac death (SCD) through comparing EP-guided interventions (anti-arrhythmic drugs, coronary revascularization, and ICD) against empirical amiodarone therapy. METHODS: Two hundred and fourteen survivors of sustained ventricular tachycardia (VT), ventricular fibrillation (VF) or SCD were randomized to either treatment strategy, pre-stratified for haemodynamic status at index event, and followed up for a median of 5 years. RESULTS: Of the 106 amiodarone arm patients, 89 (84%) received the drug and 5 (5%) received an ICD after crossing over. Of the 108 EP arm patients, 31 (29%) received an ICD, 46 (43%) received anti-arrhythmic drugs only (mainly amiodarone or sotalol) and 18 (17%) received coronary revascularization but no ICD. No significant differences in survival or arrhythmia recurrence existed between the two treatment arms after 6 years. However, ICD recipients had a lower mortality than non-ICD recipients, regardless of allocated treatment (hazard ratio=0.54, p=0.0391). CONCLUSIONS: Prospective selection of patients to receive the ICD by EP study did not improve survival compared with empirical amiodarone therapy among survivors of VT, VF or SCD, whereas ICD implantation improved survival regardless of allocated treatment. On this basis, routine EP study has no role in the management of such patients, who should be offered empirical ICD therapy according to the results of other secondary prevention ICD trials.

Amiodarone↗
PubMed2004

Sciatic nerve blockade improves early postoperative analgesia after open repair of calcaneus fractures.

OBJECTIVE: To determine the effectiveness of analgesia, with or without sciatic nerve blockade, after open repair of calcaneus fracture. DESIGN: Randomized, prospective trial involving 30 patients divided into 3 groups of 10, all having open repair of calcaneus fractures. Group 1 used morphine patient-controlled analgesia alone. Groups 2 and 3 had morphine patient-controlled analgesia and a "one-shot" bupivacaine sciatic nerve blockade, either presurgically (group 2) or postsurgically (group 3). SETTING: Harborview Medical Center operating rooms and orthopedic floors. OUTCOME MEASURES: Morphine use over 24 hours, visual analogue scale pain scores, and sciatic nerve blockade duration. RESULTS: In the absence of sciatic nerve blockade, initial postoperative pain was marked, even with a mean recovery room dose of intravenous morphine more than 30 mg. Sciatic nerve blockade with bupivacaine had a mean duration of 14 hours and substantially reduced pain for the first 24 postoperative hours. Presurgical blockade confers no advantage over postsurgical blockade. CONCLUSION: Sciatic nerve blockade confers significant benefit over morphine alone for analgesia after open repair of calcaneus fractures. Postsurgical sciatic nerve blockade provides the longest possible postoperative block duration.

Adult↗
PubMed2004

The effect of diabetes on heart rate and other determinants of myocardial oxygen demand in acute coronary syndromes.

AIMS: To compare major determinants of myocardial oxygen demand (heart rate, blood pressure and rate pressure product) in patients with and without diabetes admitted with acute coronary syndromes. METHODS: A cross-sectional study of the relation between diabetes and haemodynamic indices of myocardial oxygen demand in 2542 patients with acute coronary syndromes, of whom 1041 (41.0%) had acute myocardial infarction and 1501 (59.0%) unstable angina. RESULTS: Of the 2542 patients, 701 (27.6%) had diabetes. Major haemodynamic determinants of myocardial oxygen demand were higher in patients with than without diabetes: heart rate 80.0 +/- 20.4 vs. 75.2 +/- 19.2 beats/minute (P < 0.0001); systolic blood pressure 147.3 +/- 30.3 vs. 143.2 +/- 28.5 mmHg (P = 0.002); rate-pressure product 11533 +/- 4198 vs. 10541 +/- 3689 beats/minute x mmHg (P < 0.0001). Multiple regression analysis confirmed diabetes as a significant determinant of presenting heart rate [multiplicative coefficient (MC) 1.05; 95% confidence interval (CI) 1.03-1.07; P < 0.0001], rate pressure product (MC 1.09; CI 1.05-1.12; P < 0.0001) and systolic blood pressure, which was estimated to be 3.9 mmHg higher than in patients without diabetes (P=0.003). These effects of diabetes were independent of a range of baseline variables including acute left ventricular failure and mode of presentation (unstable angina or myocardial infarction). CONCLUSIONS: In acute coronary syndromes, heart rate and other determinants of myocardial oxygen demand are higher in patients with than without diabetes, providing a potential contributory mechanism of exaggerated regional ischaemia in this high-risk group.

Acute Disease↗
PubMed2004

Effect of body size on gastric emptying using the 13C-octanoic acid breath test.

The 13C-octanoic acid breath test (OABT) may be a useful non-invasive method for assessing the rate of gastric emptying in dogs. The aim of this study was to determine whether an association exists between body size and rate of gastric emptying in dogs. Fifty-five dogs ranging from 6 to 39 kg were recruited and rate of gastric emptying was assessed using the OABT. The time to peak 13CO2 excretion (tmax) and half-dose recovery time (t1/2) were calculated. The OABT was simple to perform and well tolerated by the dogs. Mean (sd) tmax was 2.67 hours (0.6) and mean t1/2 was 3.38 hours (0.79). Inter-individual variation in the rate of gastric emptying was 23.3 per cent for t1/2 and 22.5 per cent for tmax. No association was detected between the rate of gastric emptying and body surface area, mass, age, sex or test operator. The OABT may be a useful non-invasive and non-radioactive test for assessment of the rate of gastric emptying in dogs in clinical practice.

Animals↗
PubMed2004

Troponin testing: beware pulmonary embolus.

Serum troponin estimation is widely used in the diagnosis and management of coronary syndromes, but it is possible to be misled by a positive result unless it is put carefully into clinical context. The serum troponin can be positive in pulmonary embolus and carries prognostic significance. A case report is presented and a review of the relevant literature.

Aged↗
PubMed2004

Community based physiotherapy services in the Kivalliq Region of Nunavut, Canada.

OBJECTIVES: Community based physiotherapy services are an integral component of the recent implementation of a medical rehabilitation program in the Kivalliq Region of Nunavut. Since the year 2000, the Inuit people of Canada's central Arctic have had direct access to physiotherapy in their home communities. STUDY DESIGN: A quantitative review of physiotherapy services from January 1, 2001 to December 31, 2002. METHODS: Workload measurement data gathered by the physiotherapists in the field will be utilized to present information on referral sources, location of services provided, client diagnoses and average duration of treatment provided. Administrative data will provide information on staffing complements and challenges to date. The need for physiotherapy referrals out of the Kivalliq Region will be reviewed. RESULTS: Referral sources to physiotherapy services are varied, the majority of diagnoses are musculoskeletal in nature, followed by neurological and cardiovascular. Recruitment of the physiotherapy positions has been successful to date. Referrals out of the region for physiotherapy services have been rare since community based services have begun. CONCLUSIONS: Access to physiotherapy services by the residents of the Kivalliq Region has been significantly enhanced since the implementation of the medical rehabilitation program.

Community Health Centers↗
PubMed2004

Development of a community-based medical rehabilitation programme in the Kivalliq Region of Nunavut, Canada.

OBJECTIVE: In 2000, the University of Manitoba and the Department of Health and Social Services of Nunavut, Canada, jointly embarked upon the development of a community-based medical rehabilitation programme in the Kivalliq Region of Canada's central Arctic. Two main objectives were identified in moving forward with the implementation of a rehabilitation programme. Firstly, to conduct a region wide community needs assessment for rehabilitation services for all age groups of all residents of the Kivalliq Region of Nunavut. Secondly, to provide information from which a community-based rehabilitation therapy programme could be developed. METHODS: A community needs assessment of the Kivalliq Region was carried out to guide the implementation of physiotherapy, occupational therapy and speech language pathology services. RESULTS: There are now two physiotherapists, one occupational therapist, and one speech language pathologist providing rehabilitation services to the residents of the Kivalliq Region of Nunavut. The results of this needs assessment, the challenges and successes of this medical rehabilitation programme are discussed. CONCLUSION: The total population of the service area is approximately 8,000 people, the significant majority of whom self-report as Inuit, and are widely dispersed over eight communities. Despite the challenges in terms of culture, geography and recruitment of introducing a rehabilitation program in Canada's north, the residents of the Kivalliq Region now have a viable model of receiving rehabilitative intervention in their home communities.

Community Health Services↗
PubMed2004

Speech language pathology services in Kivalliq Region of Nunavut, Canada.

OBJECTIVES: To provide a review of Speech Language Pathology services in the Kivalliq Region of Nunavut, Canada, since its inception. Referral sources, reasons for referral and discharge will also be shown for seven of the communities in the Kivalliq Region. STUDY DESIGN: A quantitative and qualitative survey of the services received for the 26-month time period from January 2001 to February 28th, 2003. METHODS: A record review of Speech Language Pathology services was conducted. Referral sources in each community, the rate of referrals, reasons for discharge and changes in abilities of three clients were examined. RESULTS: The rate of referrals increased as the service became more familiar. Small increases in client abilities were noted over the specified time period. CONCLUSION: Speech Language Pathology services are being utilized more effectively as the referral sources become more familiar with the program.

Humans↗
PubMed2003

Measurement of the dissociation constant of Fluo-3 for Ca2+ in isolated rabbit cardiomyocytes using Ca2+ wave characteristics.

The Ca(2+) dissociation constant (K(d)) of Fluo-3 was determined using confocal fluorescence microscopy in two different situations: (i) within the cytosol of a permeabilised cardiomyocyte; and (ii) in an intact cardiomyocyte after incubation with the acetoxymethyl ester form of Fluo-3 (AM). Measurements were made on isolated rabbit ventricular cardiomyocytes after permeabilisation by a brief treatment with beta-escin (0.1mg/ml) and equilibration with 10 microM Fluo-3. The K(d) of Fluo-3 within the cytosol was not significantly different from that in free solution (558 +/- 15 nM, n=6). Over a range of cytoplasmic [Ca(2+)], the minimum [Ca(2+)] values between Ca(2+) waves was relatively constant despite changes in wave frequency. After loading intact cardiomyocytes with Fluo-3 by incubation with the -AM, spontaneous Ca(2+) waves were produced by incubation with strophanthidin (10 microM). By assuming a common minimum [Ca(2+)] in permeabilised and intact cells, the intracellular K(d) of Fluo-3 in intact myocytes was estimated to be 898 +/-64 nM (n=6). Application of this K(d) to fluorescence records shows that Ca(2+) waves in intact cells have similar amplitudes to those in permeabilised cells. Stimulation of cardiac myocytes at 0.5 Hz in the absence of strophanthidin (room temperature) resulted in a Ca(2+) transient with a maximum and minimum [Ca(2+)] of 1190 +/- 200 and 158 +/- 30 nM (n=11), respectively.

Aniline Compounds↗
PubMed2003

Cumulative risk assessment in unstable angina: clinical, electrocardiographic, autonomic, and biochemical markers.

OBJECTIVES: To determine the incremental value of clinical data, troponin T, ST segment monitoring, and heart rate variability for predicting outcome in patients with non-ST elevation acute coronary syndromes. METHODS: Prospective cohort study of 304 consecutive patients. Baseline clinical and electrocardiographic data were recorded, serial blood samples were obtained for troponin T assay, and 48 hour Holter monitoring was performed for ST segment and heart rate variability analysis. End points were cardiac death and non-fatal myocardial infarction during 12 months' follow up. RESULTS: After 12 months, 7 patients had died and 21 had had non-fatal myocardial infarction. The risk of an event was increased by troponin T > 0.1 microg/l, T wave inversion on the presenting ECG, Holter ST shift, and a decrease in the standard deviation of 5 minute mean RR intervals. Positive predictive values of individual multivariate risk were low; however, analysis of all multivariate risk markers permitted calculation of a cumulative risk score, which increased the positive predictive value to 46.9% while retaining a negative predictive value of 96.9%. CONCLUSION: A cumulative approach to risk stratification in non-ST elevation coronary syndromes successfully identifies a group in whom the risk of cardiac death or non-fatal myocardial infarction approaches 50%.

Angina, Unstable↗
PubMed2003

A single serum glucose measurement predicts adverse outcomes across the whole range of acute coronary syndromes.

OBJECTIVES: To analyse the relation between serum glucose concentration and hospital outcome across the whole spectrum of acute coronary syndromes. METHODS: This was a prospective cohort study of 2127 patients presenting with acute coronary syndromes. The patients were stratified into quartile groups (Q1 to Q4) defined by serum glucose concentrations of 5.8, 7.2, and 10.0 mmol/l. The relation between quartile group and major in-hospital complications was analysed. RESULTS: The proportion of patients with acute myocardial infarction increased incrementally across the quartile groups, from 21.4% in Q1 to 47.9% in Q4 (p < 0.0001). The trend for frequency of in-hospital major complications was similar, particularly left ventricular failure (LVF) (Q1 6.4%, Q4 25.2%, p < 0.0001) and cardiac death (Q1 0.7%, Q4 6.1%, p < 0.0001). The relations were linear, each glucose quartile increment being associated with an odds ratio of 1.46 (95% confidence interval (CI) 1.27 to 1.70) for LVF and 1.52 (95% CI 1.17 to 1.97) for cardiac death. Although complication rates were higher for a discharge diagnosis of acute myocardial infarction than for unstable angina, there was no evidence that the effects of serum glucose concentration were different for the two groups, there being no significant interaction with discharge diagnosis in the associations between glucose quartile and LVF (p = 0.69) or cardiac death (p = 0.17). Similarly there was no significant interaction with diabetic status in the associations between glucose quartile and LVF (p = 0.08) or cardiac death (p = 0.09). CONCLUSION: Admission glycaemia stratified patients with acute coronary syndromes according to their risk of in-hospital LVF and cardiac mortality. There was no detectable glycaemic threshold for these adverse effects. The prognostic correlates of admission glycaemia were unaffected by diabetic status and did not differ significantly between patients with acute myocardial infarction and those with unstable angina.

Analysis of Variance↗
PubMed2003

Temperature changes in chicken embryos exposed to a continuous-wave 1.25 GHz radiofrequency electromagnetic field.

A total of 550 fertile chicken eggs (White Leghorn) were exposed to a radiofrequency (RF) electromagnetic field of 1.25 GHz (continuous wave) at six different power flux densities in the range of 9.0-0.75 mW/cm(2). The eggs were exposed either continuously throughout the whole 21 days of incubation (long-term exposure) or in a short-term exposure (1-2 h/day). The temperatures of the embryonic tissue and the amniotic fluid, respectively, were measured with inserted temperature probes. This study was designed to investigate the relationship between exposure and temperature changes in exposed tissues, without considering biological and medical effects. This knowledge is of general interest for studies of nonthermic teratological or embryo-lethal effects of exposure to electromagnetic fields (EMFs). Throughout the entire 21 days of embryonic development, the mean temperature increases in the eggs during the exposure were found to be up to 0.25 degrees C for a power flux density of 1.25 mW/cm(2) and increased to 2.3 degrees C for 9.0 mW/cm(2). The corresponding maximum whole-body SARs for the embryos over the 21 days of embryonic development were 1.45 and 10.44 W/kg, respectively. At 0.75 mW/cm(2) (0.87 W/kg) the extent of the RF-field induced hyperthermia was within the measurement accuracy (+/-0.1 degrees C) of the temperature probes used in the tests. The field-induced temperature increase was greatest in the first week of incubation and was less pronounced in the last (third) week before hatching. In both the short- and the long-term exposures, the temperature of the exposed tissue and the amniotic fluid, respectively, reached its maximum (asymptotic) approximately 40-50 min after the RF field was switched on. After the field was switched off, the temperature inside the exposed eggs returned to its initial value within 40-50 min.

Animals↗
PubMed2002

Life events preceding suicide by young people.

BACKGROUND: Life events are often reported to precede suicide. This paper aims to determine the frequency, timing and type of life events preceding suicide by young people and those with and without a mental illness. METHOD: Informants, usually family members, were interviewed for a sample of young (less than 35 years) suicides. Information was recorded on events occurring in the 6 months before death. Equivalent information was obtained for living controls who had been matched for age and gender and obtained through the general practices of the suicides. RESULTS: Suicide was associated with life events in the previous 3 months, and particularly in the previous week. Specifically, interpersonal and forensic (being arrested, charged or sentenced) events distinguished suicides and controls. The number of life events in the different time periods under study did not distinguish suicides with and without severe mental illness, although more suicides without a severe mental illness had a reported life event in the week before their death. CONCLUSIONS: Adverse life events frequently precede suicide in young people with and without severe mental illness. However, recent life events may have a lesser causal role in those with severe mental illness. Clinical and health promotion measures to improve the way that young people cope with interpersonal problems and other crises may be an important part of any suicide prevention strategy.

Adolescent↗
PubMed2002

Co-adaptation between cassava mosaic geminiviruses and their local vector populations.

Four cassava mosaic geminivirus (CMG) isolates; African cassava mosaic virus from Namulonge, Uganda (ACMV-[Nam]), East African cassava mosaic virus from Mtwara, Tanzania (EACMV-[Mtw]), EACMV-Uganda from Namulonge (EACMV-UG[Nam]) and Indian cassava mosaic virus from Trivandrum, India (ICMV-[Tri]) were compared for their ability to be transmitted by four colonies of cassava whitefly, Bemisia tabaci (Gennadius), collected from Namulonge (NAM), Mtwara (MTW), Kumasi (KUM) and Trivandrum (TRI). With 20 adult whiteflies per test plant, the CMGs from Africa were transmitted by all three of the African B. tabaci populations to 60-79% of the target plants. Indian cassava B. tabaci transmitted ICMV-[Tri] to 89% of the target plants. In contrast, Indian cassava B. tabaci transmitted EACMV-[Mtw] and Tanzanian cassava B. tabaci transmitted ICMV-[Tri] less than a tenth as often, even when using 50 adults per plant and with increased acquisition and inoculation access periods. The complete coat protein genes of the CMGs had sequences typical of their source viruses, the major differences occurring between those originating from India and Africa. Symptom severity of the CMGs was quantified precisely by both visual assessment and image analysis techniques. EACMV-[Mtw] and ACMV-[Nam] were the most and least damaging isolates with 15.4 and 10.0% of the leaf area diseased, respectively. In these tests the transmission frequency was not linked to symptom severity in the source plants. These data support the hypothesis that virus-vector co-adaptation exists in the cassava mosaic disease (CMD) pathosystem and the results are discussed in relation to CMD epidemiology.

Adaptation, Biological↗