Biomedical subjects
C Thompson
Publications and source records attributed to C Thompson.
Critical appraisal. 8. Appraising qualitative research.
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Differential regulation of mammalian period genes and circadian rhythmicity by cryptochromes 1 and 2.
Cryptochromes regulate the circadian clock in animals and plants. Humans and mice have two cryptochrome (Cry) genes. A previous study showed that mice lacking the Cry2 gene had reduced sensitivity to acute light induction of the circadian gene mPer1 in the suprachiasmatic nucleus (SCN) and had an intrinsic period 1 hr longer than normal. In this study, Cry1(-/-) and Cry1(-/-)Cry2(-/-) mice were generated and their circadian clocks were analyzed at behavioral and molecular levels. Behaviorally, the Cry1(-/-) mice had a circadian period 1 hr shorter than wild type and the Cry1(-/-)Cry2(-/-) mice were arrhythmic in constant darkness (DD). Biochemically, acute light induction of mPer1 mRNA in the SCN was blunted in Cry1(-/-) and abolished in Cry1(-/-)Cry2(-/-) mice. In contrast, the acute light induction of mPer2 in the SCN was intact in Cry1(-/-) and Cry1(-/-)Cry2(-/-) animals. Importantly, in double mutants, mPer1 expression was constitutively elevated and no rhythmicity was detected in either 12-hr light/12-hr dark or DD, whereas mPer2 expression appeared rhythmic in 12-hr light/12-hr dark, but nonrhythmic in DD with intermediate levels. These results demonstrate that Cry1 and Cry2 are required for the normal expression of circadian behavioral rhythms, as well as circadian rhythms of mPer1 and mPer2 in the SCN. The differential regulation of mPer1 and mPer2 by light in Cry double mutants reveals a surprising complexity in the role of cryptochromes in mammals.
Effect of antidepressant drug counselling and information leaflets on adherence to drug treatment in primary care: randomised controlled trial.
OBJECTIVES: To evaluate two different methods of improving adherence to antidepressant drugs. DESIGN: Factorial randomised controlled single blind trial of treatment leaflet, drug counselling, both, or treatment as usual. SETTING: Primary care in Wessex PARTICIPANTS: 250 patients starting treatment with tricyclic antidepressants. MAIN OUTCOME MEASURES: Adherence to drug treatment (by confidential self report and electronic monitor); depressive symptoms and health status. RESULTS: 66 (63%) patients continued with drugs to 12 weeks in the counselled group compared with 42 (39%) of those who did not receiving counselling (odds ratio 2.7, 95% confidence interval 1.6 to 4.8; number needed to treat=4). Treatment leaflets had no significant effect on adherence. No differences in depressive symptoms were found between treatment groups overall, although a significant improvement was found in patients with major depressive disorder receiving drug doses of at least 75 mg (depression score 4 (SD 3.7) counselling v 5.9 (SD 5.0) no counselling, P=0.038). CONCLUSIONS: Counselling about drug treatment significantly improved adherence, but clinical benefit was seen only in patients with major depressive disorder receiving doses >/=75 mg. Further research is required to evaluate the effect of this approach in combination with appropriate targeting of treatment and advice about dosage.
Critical appraisal. 4. Questioning evidence: its validity and importance.
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Critical appraisal. 3. Searching for the evidence.
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Vancomycin derivatives that inhibit peptidoglycan biosynthesis without binding D-Ala-D-Ala.
Vancomycin is an important drug for the treatment of Gram-positive bacterial infections. Resistance to vancomycin has begun to appear, posing a serious public health threat. Vancomycin analogs containing modified carbohydrates are very active against resistant microorganisms. Results presented here show that these carbohydrate derivatives operate by a different mechanism than vancomycin; moreover, peptide binding is not required for activity. It is proposed that carbohydrate-modified vancomycin compounds are effective against resistant bacteria because they interact directly with bacterial proteins involved in the transglycosylation step of cell wall biosynthesis. These results suggest new strategies for designing glycopeptide antibiotics that overcome bacterial resistance.
Examining evidence: an overview.
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Glyceryl trinitrate and ritodrine in tocolysis: an international multicenter randomized study. GTN Preterm Labour Investigation Group.
OBJECTIVE: To compare the efficacy of transdermal glyceryl trinitrate and intravenous (IV) ritodrine as tocolytics. METHODS: Two hundred forty-five women with preterm labor and intact membranes between 24 and 36 weeks' gestation were randomized to transdermal glyceryl trinitrate or intravenous ritodrine. Treatment was continued until contractions stopped or a maximum of 7 days. Glyceryl trinitrate was administered as a 10- or 20-mg transdermal patch. Intravenous ritodrine was administered according to nationally available guidelines. The primary outcome was prolongation of gestation expressed as a percentage of the time from entry to 37 weeks. Secondary outcomes were proportion of women who delivered the same day, next day, or within 7 and 14 days of entry, and by 32, 34, and 37 weeks. Analysis was by intention to treat. RESULTS: Twelve women (5%) were lost to follow-up. Glyceryl trinitrate and ritodrine prolonged gestation by 74% of time to 37 weeks (difference glyceryl trinitrate-ritodrine 0%; 95% confidence interval (CI) -10%, +10%). There was no significant difference in the proportion of women receiving glyceryl trinitrate or ritodrine who delivered within the specified days from study entry or weeks of gestation; however, 42 women who received glyceryl trinitrate and 58 women who received ritodrine delivered by 37 weeks (difference -11%; 95% CI -24%, +2%). No serious maternal side effects were reported for ritodrine or glyceryl trinitrate. CONCLUSION: We found no overall difference between glyceryl trinitrate and ritodrine in the acute tocolysis of preterm labor but a suggested advantage of glyceryl trinitrate over ritodrine in reducing preterm delivery rate. The maternal side effect profile and treatment discontinuation rates were fewer for glyceryl trinitrate, suggesting it was a safer alternative to ritodrine.
Maternal and fetal cardiovascular effects of transdermal glyceryl trinitrate and intravenous ritodrine.
OBJECTIVE: To determine the maternal and fetal cardiovascular effects of transdermal glyceryl trinitrate compared with ritodrine for acute tocolysis. METHODS: Sixty women in preterm labor were enrolled in this study that was part of a multicenter study of glyceryl trinitrate. Once randomized, the women received transdermal glyceryl trinitrate or intravenous ritodrine for acute tocolysis. Measurements of maternal pulse, blood pressure (BP), and fetal heart rate (FHR) were recorded for up to 24 hours and compared over the treatment course. RESULTS: Changes from baseline in mean maternal heart rate, FHR, and maternal BP (mean arterial pressure [MAP]) were compared between the glyceryl trinitrate and ritodrine groups over the entire treatment course. The mean change from baseline in maternal heart rate was 21.1 beats per minute less (95% confidence interval [CI] 15.7, 26.5, P < .001), and the mean maternal heart rate was 21.8 beats per minute lower (95% CI 16.9, 26.7, P < .001) in the glyceryl trinitrate group. The mean change in FHR was 9.2 beats per minute less (95% CI 3.8, 14.6, P = .001) and the mean FHR significantly lower (6.9 beats per minute, 95% CI 1.9, 11.9, P = .008) during glyceryl trinitrate treatment. Ritodrine had a significantly hypotensive effect on MAP (95% CI -4.3, 0.0, P = .03). Mean arterial pressure was not significantly different over the treatment course. CONCLUSION: At doses required for acute tocolysis, transdermal glyceryl trinitrate had minimal effects on maternal pulse, BP, and FHR, and significantly fewer adverse cardiovascular effects than intravenous ritodrine. Thus, transdermal glyceryl trinitrate might be a safer treatment for women in preterm labor.
The unhealthy lifestyle of people with schizophrenia.
BACKGROUND: Schizophrenia has a high natural mortality of a largely environmental aetiology. There is, however, little research about possible risk factors. This study measured the diet, cigarette and alcohol use, exercise and obesity of a cohort of people with schizophrenia and compared results to general population rates. METHODS: Semi-structured interview using validated research instruments on 102 middle-aged subjects with a diagnosis of schizophrenia, living in the community. Results were compared to general population norms using standard statistical tests. RESULTS: The subjects ate a diet higher in fat and lower in fibre than the general population. They look little exercise but were not significantly more obese. They smoked heavily but drank less alcohol. Most differences remained significant after controlling for social class. CONCLUSIONS: People with schizophrenia have an unhealthy lifestyle, which probably contributes to the excess mortality of the disease. They are therefore an appropriate target group for health promotion interventions.
A dog microsatellite at the VIAS-D21 locus with demonstrated linkage to the marker CXX20.
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A conceptual treadmill: the need for 'middle ground' in clinical decision making theory in nursing.
This paper explores the two predominant theoretical approaches to the process of nurse decision making prevalent within the nursing research literature: systematic-positivistic approaches as exemplified by information processing theory, and the intuitive-humanistic approach of Patricia Benner. The two approaches' strengths and weaknesses are explored and as a result a third theoretical stance is proffered: the idea of a cognitive continuum. According to this approach the systematic and intuitive theoretical camps occupy polar positions at either end of a continuum as opposed to separate theoretical planes. The methodological and professional benefits of adopting such a stance are also briefly outlined.
Factors associated with failure of medical therapy in patients with unstable angina and non-Q wave myocardial infarction. A TIMI-IIIB database study.
CONTEXT: Current management of patients with unstable angina and non-Q wave myocardial infarction generally consists of intensive medical therapy, with angiography and revascularization sometimes limited to those who fail such therapy. AIM: To determine if certain baseline characteristics are predictive of patients who fail medical therapy, since such patients could then be expeditiously directed to a more invasive strategy in a cost-effective manner. METHODS: The study cohort consisted of the 733 patients in the Thrombolysis in Myocardial Ischemia (TIMI) IIIB study who were randomized to conservative strategy. Patients were to be treated with bedrest, anti-ischaemic medications, aspirin, and heparin, and were to undergo risk-stratifying tests, consisting of an exercise test with ECG and thallium scintigraphy, scheduled to be performed within 3 days prior to, or 5 days after, hospital discharge and 24 h Holter monitoring scheduled to begin 2-5 days after randomization. Baseline clinical and ECG characteristics were compared between patients who 'failed' medical therapy and those who did not 'fail'. Failure was defined using clinical end-points (death, myocardial infarction, or spontaneous ischaemia by 6 weeks after randomization) or a strongly positive risk-stratifying test. For each test an ordered failure profile of results was calculated and consisted of death, myocardial infarction, or rest ischaemia occurring prior to performance of the test, a markedly abnormal test result, and no abnormality. RESULTS: Clinical end-points occurred in 241 (33%) patients and were more likely to occur in patients who at presentation were older, had ST-segment depression on the qualifying ECG, or were being treated with heparin or aspirin. Characteristics independently predictive of developing a clinical event or an abnormal exercise treadmill test included: ST-segment depression on the qualifying ECG, history of prior angina, family history of premature coronary disease (i.e. onset <55 years of age), prior use of heparin or aspirin, and increasing age. By combining these baseline risk characteristics for each outcome the incidence of developing a clinical event ranged from 8% if none was present to 63% if all six were present, and of developing a markedly abnormal risk stratifying test from 8-21% if none were present to approximately 90% if all six were present. CONCLUSIONS: Baseline characteristics associated with developing a clinical event or a markedly abnormal risk stratifying test were similar: rest anginal episode accompanied by ST-segment depression and occurring despite treatment with aspirin and heparin, a history of angina, older age, and family history of coronary disease. Patients with these characteristics are appropriate candidates for expeditious cardiac catheterization and consideration for revascularization, while patients without them may be suitable for medical management alone.
Occupational exposure and voluntary human immunodeficiency virus testing: a survey of Maryland hospitals.
A survey was conducted to estimate how often healthcare providers were exposed to patients' blood and the percentage of incidents in which patients agreed to human immunodeficiency virus (HIV) testing. Data from 38 hospitals with 53,508 employees revealed 2,244 exposures. Of 1,732 requests for information regarding the HIV status of the source patient, only 77 (6%) resulted in the patient's refusal to consent to an HIV test.
Simultaneous vitamin A administration at routine immunization contact enhances antibody response to diphtheria vaccine in infants younger than six months.
A randomized, double-blind, placebo-controlled trial was conducted to evaluate the effect of simultaneous vitamin A supplementation and diphtheria, pertussis and tetanus (DPT) vaccination on the antibody levels. Infants aged 6-17 wk (n = 56) were randomly given 15 mg oral vitamin A or placebo at the time of their DPT immunization. Three such doses were given at monthly intervals. Immunoglobulin (Ig) G antibodies to diphtheria, pertussis and tetanus were assayed on enrollment and 1 mo after the third dose. Baseline antibody concentrations to diphtheria, pertussis and tetanus did not differ between the vitamin A-supplemented and placebo-treated groups. The postdose antibody to diphtheria level was significantly greater in the vitamin A than in the placebo-treated group. The geometric mean +/- SEM antibody levels (mg/L) were 22.9 +/- 1.2 and 11.0 +/- 1.3 in the vitamin A and placebo groups, respectively (P = 0.029). The postsupplementation concentrations of antibodies to pertussis and tetanus did not differ between the two groups. These results suggest that antibody response to diphtheria vaccination was potentiated by simultaneous vitamin A administration and DPT immunization.
Qualitative research into nurse decision making: factors for consideration in theoretical sampling.
This article details some of the theoretical sampling choices available to researchers considering qualitative approaches to research into nurse decision making and the information that informs it. It draws on the theoretical and empirical literature on decision theory and, in so doing, provides a rationale for the theoretical sampling choices proposed. The final sampling frame is designed to be applied to decision research in nursing but could offer starting points for research into the decisions of other professional clinical groups.
The confidential inquiry comes of age.
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