Biomedical subjects
Publications and source records attributed to C Thompson.
Mechanical valve thrombosis is a life-threatening event, and prevention with meticulous anticoagulation is crucial. Pregnancy is associated with a hypercoagulable state that further emphasizes the importance of adequate anticoagulation. A case of mechanical mitral valve thrombosis in a pregnant woman due to suboptimal anticoagulation is presented. Methods of anticoagulation, as well as thrombolytic and surgical therapies, are discussed.
The DiSC Project aims to assess the feasibility, effectiveness and costs of diabetes shared care in Ireland. Baseline results provide a profile of diabetes care in Ireland. Thirty general practices are participating in this randomised controlled trial. Outcomes include biophysical and psychosocial measures. The majority of patients agreed to participate in diabetes shared care. Data was collected from 183 patients with type 2 diabetes. The mean age of the patients is 65 years, 56% are male and 63% are GMS eligible. The mean HBA1c was 6.8% though 21% of patients had a HBA1c>8%. The majority of patients had a blood pressure, total cholesterol and body mass index above recommended guidelines. Only half the patients are attending a dietician or a chiropodist. The majority of patients have good glycaemic control but poor blood pressure and cholesterol control. The full trial results will determine if a shared care approach can improve clinical and psychosocial outcomes for patients.
Records of patients included in a trial of educating practice teams about the management of depression were examined to determine changes in the process of care. There were no significant differences in the proportions recognised or treated for depression. Only 15% of those with possible, and 26% of those with probable, major depressive disorder were prescribed recommended doses and duration of antidepressants. The education apparently delayed a switch away from tricyclics while achieving a similar outcome. However health service costs were mainly non-psychiatric, and there were no significant savings as a result.
The daily light-dark (LD) cycle exerts a powerful influence on the temporal organization of behavior and physiology. Much of this influence is preserved in behaviorally blind retinally degenerate mice; the photoreceptors underlying this nonvisual phototransduction are unknown. The mammalian eye contains at least two classes of photoactive pigments, the vitamin A-based opsins and the vitamin B(2)-based cryptochromes. To genetically define the roles of these pigments in light modulation of behavior, we generated rd/rd;mCry1(-)/mCry1(-);mCry2(-)/mCry2(-) mutant mice lacking rods and most cones as well as both cryptochrome proteins. The response of the mutant mouse to photic input was analyzed at both behavioral and molecular levels. Behaviorally, mice lacking either classical photoreceptors or cryptochromes exhibited strongly rhythmic locomotor responses to 10 and 100 lux daily LD 12 h/12-h cycles; however, triple mutant mice carrying both cryptochrome and retinal degenerate mutations were nearly arrhythmic under both LD cycles and in constant darkness. At the molecular level, the light induction of c-fos transcription in the suprachiasmatic nucleus was markedly reduced in the triple mutant mouse compared with either rd/rd or cryptochrome mutant mice. These data indicate that classical opsins and cryptochromes serve functionally redundant roles in the transduction of light information to behavioral modulation and suggest a pleomorphic role for cryptochromes in both photoreception and central clock mechanism.
In the human inflammatory myopathies (polymyositis and dermatomyositis), the early, widespread appearance of MHC class I on the surface of muscle cells and the occurrence of certain myositis-specific autoantibodies are striking features. We have used a controllable muscle-specific promoter system to up-regulate MHC class I in the skeletal muscles of young mice. These mice develop clinical, biochemical, histological, and immunological features very similar to human myositis. The disease is inflammatory, limited to skeletal muscles, self-sustaining, more severe in females, and often accompanied by autoantibodies, including, in some mice, autoantibodies to histidyl-tRNA synthetase, the most common specificity found in the spontaneous human disease, anti-Jo-1. This model suggests that an autoimmune disease may unfold in a highly specific pattern as the consequence of an apparently nonspecific event-the sustained up-regulation of MHC class I in a tissue-and that the specificity of the autoantibodies derives not from the specificity of the stimulus, but from the context, location, and probably the duration of the stimulus. This model further suggests that the presumed order of events as an autoimmune disease develops needs to be reconsidered.
Explore the source record for details and available documents.
BACKGROUND: Sympathetic activation may limit exercise performance by restraining muscle blood flow or by negatively affecting skeletal muscle metabolic behavior. To test this hypothesis, we studied the effect of thoracoscopic sympathetic trunkotomy (TST) on forearm exercise duration, blood flow, and muscle bioenergetics in 13 patients with idiopathic palmar hyperhidrosis. METHODS AND RESULTS: Heart rate and beat-by-beat mean arterial pressure were recorded at rest and during right and left rhythmic handgrip before and 4 to 7 weeks after right TST. Forearm blood flow was measured bilaterally at rest and on the right during exercise. Right forearm muscle phosphocreatine content and intracellular pH were assessed by (31)phosphorus magnetic resonance spectroscopy. After right TST, exercise duration increased from 8.9+/-1.4 to 13.4+/-1.8 minutes (P<0.0001) with the right forearm and from 5.7+/-0.4 to 7.6+/-0.9 minutes (P<0.05) with the left (P<0.05 for the interaction between treatment and side). Right forearm blood flow at rest was 66% higher (P<0.01) after right TST, but this difference decreased as the exercise progressed. After right TST, a significant reduction occurred in muscle acidification and phosphocreatine depletion during ipsilateral forearm exercise. This was associated with a significantly reduced mean arterial pressure response to right handgrip, whereas the pressor response to left handgrip did not change. CONCLUSIONS: Sympathetic denervation of the upper limb significantly improves forearm skeletal muscle bioenergetics and exercise performance in patients with idiopathic palmar hyperhidrosis.
We have phase-connected a sequence of Rossi X-Ray Timing Explorer Proportional Counter Array observations of SGR 1806-20 covering 178 days. We find that a simple secular spin-down model does not adequately fit the data. The period derivative varies gradually during the observations between 8.1x10-11 and 11.7x10-11 s s(-1) (at its highest, approximately 40% larger than the long-term trend), while the average burst rate as seen with the Burst and Transient Source Experiment drops throughout the time interval. The phase residuals give no compelling evidence for periodicity, but more closely resemble timing noise as seen in radio pulsars. The magnitude of the timing noise, however, is large relative to the noise level typically found in radio pulsars (Delta8=4.8; frequency derivative average power approximately 7x10-20 cycles(2) s(-3)). Combining these results with the noise levels measured for some anomalous X-ray pulsars, we find that all magnetar candidates have Delta(8) values larger than those expected from a simple extrapolation of the correlation found in radio pulsars. We find that the timing noise in SGR 1806-20 is greater than or equal to the levels found in some accreting systems (e.g., Vela X-1, 4U 1538-52, and 4U 1626-67), but the spin-down of SGR 1806-20 has thus far maintained coherence over 6 yr. Alternatively, an orbital model with a period Porb=733 days provides a statistically acceptable fit to the data. If the phase residuals are created by Doppler shifts from a gravitationally bound companion, then the allowed parameter space for the mass function (small) and orbital separation (large) rule out the possibility of accretion from the companion sufficient to power the persistent emission from the SGR.
The mechanism of injury and death of muscle cells in the inflammatory myopathies (dermatomyositis, polymyositis, and inclusion body myositis) remains obscure. We and others have not detected apoptosis in the muscle biopsies from patients with myositis despite clear evidence of cell damage and loss. We provide evidence in this study that Fas ligand (FasL) as well as Fas is present on muscle cells and inflammatory cells in myositis biopsies: Fas is present on most muscle cells and lymphocytes, and FasL is present on degenerating muscle cells and many infiltrating mononuclear cells. The expression of both Fas and FasL in the inflamed tissue makes the absence of apoptosis more striking. To address the mechanisms of this resistance to classical apoptosis in muscle cells, we have investigated the expression of the antiapoptotic molecule FLICE (Fas-associated death domain-like IL-1-converting enzyme)-inhibitory protein (FLIP) in muscle biopsies of myositis patients and in cultured human skeletal muscle cells. Using laser capture microscopy, we have shown that FLIP is expressed in the muscle fibers and on infiltrating lymphocytes of myositis biopsies. Furthermore, we have shown that FLIP, but not Bcl-2, is expressed in cultured human skeletal muscle cells stimulated with proinflammatory cytokines, and inhibition of FLIP with antisense oligonucleotides promotes significant cleavage of poly(ADP-ribose) polymerase autoantigen, a sensitive indicator of apoptosis. These studies strongly suggest that the resistance of muscle to Fas-mediated apoptosis is due to the expression of FLIP in muscle cells in the inflammatory environment in myositis.
AIM: To determine the glycaemic index values to a range of foods that are unique to New Zealand, and those that are grown and/or manufactured locally. METHODS: We determined the glycaemic index of 28 carbohydrate foods in both healthy subjects and those with type 2 diabetes. Venous blood samples were collected over two to three hours, and the incremental area under the blood glucose curve was used to calculate glycaemic index values. RESULTS AND CONCLUSIONS: This study has identified the glycaemic index values for a range of New Zealand foods which will be clinically useful in the nutritional management of individuals with diabetes mellitus. People with diabetes are recommended to choose foods with a low glycaemic index which is associated with optimal blood glucose control and lipid levels.
We present statistics of SGR 1806-20 bursts, combining 290 events detected with the Rossi X-Ray Timing Explorer/Proportional Counter Array, 111 events detected with the Burst and Transient Source Experiment, and 134 events detected with the International Cometary Explorer. We find that the fluence distribution of bursts observed with each instrument are well described by power laws with indices 1.43, 1.76, and 1.67, respectively. The distribution of time intervals between successive bursts from SGR 1806-20 is described by a lognormal function with a peak at 103 s. There is no correlation between the burst intensity and either the waiting times until the next burst or the time elapsed since the previous burst. In all these statistical properties, SGR 1806-20 bursts resemble a self-organized critical system, similar to earthquakes and solar flares. Our results thus support the hypothesis that the energy source for soft gamma repeater bursts is crustquakes due to the evolving, strong magnetic field of the neutron star, rather than any accretion or nuclear power.
BACKGROUND: Depression is a major individual and public-health burden throughout the world and is managed mainly in primary care. The most effective strategy to reduce this burden has been believed to be education of primary-care practitioners. We tested this assumption by assessing the effectiveness of an educational programme based on a clinical-practice guideline in improving the recognition and outcome of primary-care depression. METHODS: We carried out a randomised controlled trial in a representative sample of 60 primary-care practices (26% of the total) in an English health district. Education was delivered to practice teams and quality tested by feedback from participants and expert raters. The primary endpoints were recognition of depression, defined by the hospital anxiety and depression (HAD) scale, and clinical improvement. Analysis was by intention to treat. FINDINGS: The education was well received by participants, 80% of whom thought it would change their management of patients with depression. 21409 patients were screened, of whom 4192 were classified as depressed by the HAD scale. The sensitivity of physicians to depressive symptoms was 39% in the intervention group and 36% in the control group after education (odds ratio 1.2 [95% CI 0.88-1.61]). The outcome of depressed patients as a whole at 6 weeks or 6 months after the assessment did not significantly improve. INTERPRETATION: Although well received, this in-practice programme, which was designed to convey the current consensus on best practice for the care of depression, did not deliver improvements in recognition of or recovery from depression.
BACKGROUND: Research has highlighted the problems for carers of people with dementia. These include the effective loss of companionship and support of a life partner, social isolation and complex financial, legal and social decision making. The burden of caring is financially, emotionally and physically significant. Studies of the effects of ways of supporting carers and reducing the burden of caring often examine a range of outcomes. Probably because of these characteristics, no formal overview of this area of service provision has been undertaken. Moreover, the term 'intervention' in relation to caregivers of people with Alzheimer's disease is open to wide variations in interpretation at the level of service provision. Interventions range from the application of 'hi-tech' computer technology for socialy isolated carers, to the formation of specialist support groups and respite services. OBJECTIVES: The objective of this review is to provide an assessment of the effectiveness of health and/or social interventions designed to help support the carers of people with Alzheimer's-type dementias. SEARCH STRATEGY: The Cochrane Controlled Trials Register was searched using the terms 'carer*' and 'caregiv*'. See the Cochrane Dementia & Cognitive Impairment group's details for the full search strategy. SELECTION CRITERIA: All randomised trials in which primary carers of people with Alzheimer's disease are allocated to either intervention or non-intervention/control groups and where the intervention was provided by healthcare and/or social services. DATA COLLECTION AND ANALYSIS: Data was extracted by both reviewers and was found to be unsuitable for quantitative synthesis. A qualitative overview is presented and structured according to the comparisons used in the review. Weighted Mean Differences (weighted by sample size) for each outcome and its subcategories are also presented. MAIN RESULTS: The results of the review are inconclusive. No evidence was found for the following comparison interventions: 1) individualised service assessment and planning versus conventional support 2) technology-based carer networking (via computers or telephones) versus conventional support 3) carer-education/training versus conventional support 4) multi-faceted/dimensional strategies (such as specialised carer assessment and training) versus conventional support Whilst the overview suggests little or no evidence that interventions to support caregivers of people with Alzheimer's disease are of quantifiable benefit, the poor quality and small sample sizes of the studies, as well as the diversity of interventions examined and outcomes reported, mean that this conclusion cannot be put forward without the need for caution, particularly as some of the studies put forward qualitative evidence which contradicts this conclusion. REVIEWER'S CONCLUSIONS: With the limited nature of the research evidence in mind, it is not possible to recommend either wholesale investment in caregiver support programmes or withdrawal of the same. With the addition of further studies in future updates of this review, expected in early 1999, this presently inconclusive picture may become clearer. A number of conclusions relating to future areas of research can be put forward with more conviction. Specifically, 1) Future trials need to examine interventions included in the existing knowledge base on Alzheimer's carer-supportive interventions. 2) Outcome measures used should mirror those in similar studies. 3) Outcome measures need to be clinically and 'lay' relevant. 4) Trials need to be of longer duration given the 7-10 years median life expectancy of people with Alzheimer's Disease. 5) Sample sizes need to be increased and calculated properly given the likelihood of a moderate intervention effect (if any). 7) Blinding at the outcome assessment stage needs to be a part of future basic trial designs if bias is to be avoided. 8) If reviews are to have their power increased then quality o
The aim of this work is to discuss the ethical issues regarding the use of electroconvulsive therapy (ECT) in adolescents. Ethical implications of ECT in adolescents are analyzed in the light of general medical ethics, which include five prominent principles with respect to autonomy, nonmaleficence, beneficence, justice, and cautiousness. As adults, adolescents with acute psychotic impairment raise an inherent conflict between the respect for the patient's autonomy, on the one side, and the principle of beneficence on the other. However, this age group presents particular dilemmas: (i) As any adolescent suffering from a psychiatric illness is a highly vulnerable subject, society asks for particular attention. The consequence of potential overprotection is that the adolescent may remain untreated because of unrealistic fears regarding ECT. (ii) Some of these fears are linked to the cognitive secondary effects of ECT. Although preliminary data are reassuring, more empirical research on this population should be encouraged. (iii) Cautiousness recommends the use of ECT in limited indications catatonia, mood disorders, and intractable acute psychotic disorders. We conclude that there is no ethical reason to ban the use of ECT in adolescents. Ethical options in clinical practice must be evaluated empirically with respect to the consequences for the patient. Dogmatic views should be set aside.
OBJECTIVES: To assess the association between dietary fat and various urinary risk factors of calcium stone disease in a group of calcium stoneformers attending an outpatient stone clinic. METHODS: Mean daily fat intake from self-recorded 4-day dietary food records and mean 24-hour urinary risk factors from two separate collections were evaluated in 476 patients selected randomly from an adult population attending an outpatient stone clinic for the first time. RESULTS: Mean daily total fat intake for men and women was significantly different at 105.6 and 78.1 g, respectively. Examination of the relationship between total fat intake and 24-hour urinary volume, pH, and excretions of magnesium, citrate, oxalate, calcium, and uric acid revealed no significant regressions in men and only a weak association between fat intake and urinary uric acid in women. CONCLUSIONS: Dietary fat does not have a significant effect on the urinary risk factors of calcium stone disease.
This study examines the presence of hepatitis B as a possible precursor marker for HIV/AIDS in 10 districts of Zagreb, Croatia. There were a total of 931 cases of hepatitis B in Zagreb in the period 1979-1995, the annual rate ranging from 3.1 to 15.4 per 10,000. The highest relative risk for hepatitis B for the 1979-1995 period was in the Pescenica district (Relative risk (RR): 1.4). There were 108 cases of HIV/AIDS diagnosed in Croatia in the period 1986-1996, with 34% from Zagreb. The highest relative risk for HIV/AIDS was within the Pescenica district (RR: 2.3). Pescenica had also a significantly higher incidence of hepatitis B when compared to other districts (p = 0.005). The cumulative incidence of hepatitis B in Zagreb was directly related to levels of neighborhood discomfort as determined by an index including unemployment, inflation and housing conditions (p = 0.005). This research demonstrates that the poor areas of the city with higher incidence of hepatitis B hold the greatest threat for the spread of HIV/AIDS.
Explore the source record for details and available documents.
AIMS: To assess the advantages and disadvantages of four methods for studying compliance with antidepressants: self-report scores, tablet counts, a microprocessor (MEMS) container system and the assay of nordothiepin and dothiepin concentrations in plasma. METHODS: The techniques were used in 88 patients commencing tricyclic antidepressants in the setting of UK general practice. RESULTS: The MEMS system proved to be the most informative technique allowing identification of the precise time of container opening, the demonstration of 'drug holidays' and early cessation of therapy. Self-report scores (Morisky) proved a useful screening technique with a sensitivity of 72.2% and specificity of 74.1% for > or = 80% compliance. Although tablet counts were possible in 84 patients (95. 5%) they were unreliable in 19 (21.6%). Blood concentration assays proved the least acceptable method to patients and were possible in only 53 (60.2%). A ratio of nordothiepin:dothiepin > or = 1.1 claimed, by others, to identify noncompliance was only reliable when concentrations were low. CONCLUSIONS: Both the MEMS system and self-report scores proved useful methods for identifying noncompliant patients in the setting of UK general practice. Although compliance was higher than reported in previous studies with 70 patients (79.5%) completing 6 weeks treatment, general practitioners tended to prescribe subtherapeutic doses.