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Biomedical subjects

H C Bucher

Publications and source records attributed to H C Bucher.

51 records · Page 3Linked to original sources

DOTATOC: a powerful new tool for receptor-mediated radionuclide therapy.

This study presents the first successful use of a peptidic vector, DOTATOC, labelled with the beta-emitting radioisotope yttrium-90, for the treatment of a patient with somatostatin receptor-positive abdominal metastases of a neuroendocrine carcinoma of unknown localization. Tumour response and symptomatic relief were achieved. In addition, the new substance DOTATOC was labelled with the diagnostic chemical analogue indium-111 and studied in three patients with histopathologically verified neuroendocrine abdominal tumours for its diagnostic sensitivity and compared with the commercially available OctreoScan. In all patients the kidney-to-tumour uptake ratio (in counts per pixel) was on average 1. 9-fold lower with 111In-DOTATOC than with OctreoScan. DOTATOC could be a potential new diagnostic and therapeutic agent in the management of neuroendocrine tumours.

Abdominal Neoplasms↗

[HIV prevention in Turkish immigrants in a general internal medicine outpatient service].

This study investigates the level of knowledge about mechanisms of HIV transmission and risk behaviour for HIV infection in Turkish immigrants in Basel, Switzerland. In addition, the effectiveness of physician based HIV counseling in a general internal medicine outpatient clinic was evaluated. Two consecutive samples of 150 and 98 Turkish patients with a first clinic contact, were recruited 6 months apart. The first group was exposed to an interpreter assisted counseling on HIV prevention (intervention group), the control group received no systematic counseling. Knowledge about mechanisms of HIV transmission and risk behaviour for HIV infection was assessed by a 29 item questionnaire at baseline and by interview at follow-up. One year follow-up was possible in 49% of the patients. At baseline, Turkish patients had statistically significant lower global scores on knowledge about HIV than a second control group of 148 Swiss patients. Mean percentage scores of correct answers in the whole Turkish study population improved from 49.3% to 60.0% (p < 0.0001). However, the difference of gained knowledge between intervention and control groups was only of borderline significance (p = 0.059). Study design and low follow-up limit conclusions from this study. From 1992 to 1994 knowledge about HIV infection had improved in Turkish patients, but was still inferior to the knowledge of Swiss patients.

Adult↗

The results of direct and indirect treatment comparisons in meta-analysis of randomized controlled trials.

When little or no data directly comparing two treatments are available, investigators often rely on indirect comparisons from studies testing the treatments against a control or placebo. One approach to indirect comparison is to pool findings from the active treatment arms of the original controlled trials. This approach offers no advantage over a comparison of observational study data and is prone to bias. We present an alternative model that evaluates the differences between treatment and placebo in two sets of clinical trials, and preserves the randomization of the originally assigned patient groups. We apply the method to data on sulphamethoxazole-trimethoprim or dapsone/pyrimethamine as prophylaxis against Pneumocystis carinii in HIV infected patients. The indirect comparison showed substantial increased benefit from the former (odds ratio 0.37, 95% CI 0.21 to 0.65), while direct comparisons from randomized trials suggests a much smaller difference (risk ratio 0.64, 95% CI 0.45 to 0.90; p-value for difference of effect = 0.11). Direct comparisons of treatments should be sought. When direct comparisons are unavailable, indirect comparison meta-analysis should evaluate the magnitude of treatment effects across studies, recognizing the limited strength of inference.

AIDS-Related Opportunistic Infections↗

The Delta trial.

Explore the source record for details and available documents.

Antiviral Agents↗

Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials.

OBJECTIVE: To review the effect of calcium supplementation during pregnancy on blood pressure, preeclampsia, and adverse outcomes of pregnancy. DATA SOURCE: We searched MEDLINE and EMBASE for 1966 to May 1994. We contacted authors of eligible trials to ensure accuracy and completeness of data and to identify unpublished trials. STUDY SELECTION: Fourteen randomized trials involving 2459 women were eligible. DATA EXTRACTION: Reviewers working independently in pairs abstracted data and assessed validity according to six quality criteria. DATA SYNTHESIS: Each trial yielded differences in blood pressure change between calcium supplementation and control groups that we weighted by the inverse of the variance. The pooled analysis showed a reduction in systolic blood pressure of -5.40 mm Hg (95% confidence interval [CI], -7.81 to -3.00 mm Hg; P<.001) and in diastolic blood pressure of -3.44 mm Hg (95% CI, -5.20 to -1.68 mm Hg; P<.001). The odds ratio for preeclampsia in women with calcium supplementation compared with placebo was 0.38 (95% CI, 0.22 to 0.65). CONCLUSIONS: Calcium supplementation during pregnancy leads to an important reduction in systolic and diastolic blood pressure and preeclampsia. While pregnant women at risk of preeclampsia should consider taking calcium, many more patient events are needed to confirm calcium's impact on maternal and fetal morbidity.

Blood Pressure↗

Effects of dietary calcium supplementation on blood pressure. A meta-analysis of randomized controlled trials.

OBJECTIVE: To review the effect of supplemental calcium on blood pressure. DATA SOURCE: We searched MEDLINE and EMBASE for 1996 to May 1994. We contacted authors of eligible trials to ensure accuracy and completeness of data and to identify unpublished trials. STUDY SELECTION: We included any study in which investigators randomized people to calcium supplementation or placebo and measured blood pressure for at least 2 weeks. Fifty-six articles met the inclusion criteria, and 33 were eligible for analysis, involving a total of 2412 patients. DATA EXTRACTION: Two pairs of independent reviewers abstracted data and assessed validity according to six quality criteria. DATA SYNTHESIS: We calculated the differences in blood pressure change between the calcium supplementation group and the control group and pooled the estimates, with each trial weighted with the inverse of the variance using a random-effects model. Predictors of blood pressure reduction that we examined included method of supplementation, baseline blood pressure, and the methodological quality of the studies. The pooled analysis showed a reduction in systolic blood pressure of -1.27 mm Hg (95% confidence interval [CI], -2.25 to -0.29 mm Hg; P=.01) and in diastolic blood pressure of -0.24 mm Hg (95% CI, -0.92 to 0.44 mm Hg; P=.49). None of the possible mediators of blood pressure reduction explained differences in treatment effects. CONCLUSIONS: Calcium supplementation may lead to a small reduction in systolic but not diastolic blood pressure. The results do not exclude a larger, important effect of calcium on blood pressure in subpopulations. In particular, further studies should address the hypothesis that inadequate calcium intake is associated with increased blood pressure that can be corrected with calcium supplementation.

Blood Pressure↗

Socioeconomic indicators and mortality from coronary heart disease and cancer: a 22-year follow-up of middle-aged men.

OBJECTIVES: Data from the Western Collaborative Group Study were used to determine the extent to which the inverse association between socioeconomic status (SES) and mortality can be explained by risk factors for major causes of mortality. METHODS: The relation of education and income to subsequent mortality was studied in 3154 employed, middle-aged men over 22 years of follow-up. RESULTS: Over the follow-up period, 584 (18.5%) men died, 214 (6.8%) from coronary heart disease and 70 (2.2%) from lung cancer. A significant inverse association with systolic blood pressure, serum cholesterol, and smoking was found only for education. For education, adjustment for risk factors reduced the relative risk for coronary heart disease mortality from 1.80 (95% confidence interval = 1.33, 2.44) to 1.54 (1.13, 2.09), for lung cancer mortality from 1.60 (0.95, 2.70) to 1.38 (0.81, 2.34), and for all-cause mortality from 1.49 (1.09, 1.13) to 1.33 (1.12, 1.60). For income, adjustment for risk factors did not change relative risk for mortality from coronary heart disease (1.27 [0.97, 1.66]) and all causes (1.21 [1.03, 1.43]), but it did increase the relative risk for lung cancer mortality from 1.68 (1.05, 2.68) to 1.83 (1.13, 2.96). CONCLUSIONS: In middle-aged, employed men, the association between SES and mortality is partially but not completely accounted for by major risk factors for mortality.

Adult↗

HIV-enteropathy and bile acid malabsorption: response to cholestyramine.

Chronic diarrhea and weight loss are common in patients with AIDS. We report on an AIDS patient with chronic diarrhea, steatorrhea, and marked weight loss. A 75SeHCAT test demonstrated that the diarrhea was mainly due to bile acid malabsorption. Therapy with cholestyramine dramatically reduced bowel movements and led to significant reversal of weight loss.

AIDS-Related Opportunistic Infections↗

Influence of method of reporting study results on decision of physicians to prescribe drugs to lower cholesterol concentration.

OBJECTIVE: To determine whether the reporting of study results by using reductions in relative or absolute risk and the number needed to treat affects the views of physicians about the effectiveness of drugs to lower lipid concentrations and decisions about treatment. DESIGN: Random allocation of two questionnaires presenting the results of three end points of the Helsinki heart study as results from separate trials by using reduction in either relative or absolute risk. In both questionnaires one end point was also presented by showing person years of treatment needed to prevent one myocardial infarction. The effectiveness of lipid lowering drugs was assessed for all end points on an 11 point scale. For each study result the likelihood to treat hypercholesterolaemia of 7.5 mmol/l in a healthy man had to be indicated on a seven point scale. SUBJECTS: Random sample of 802 internists and general practitioners representative of providers of primary care in Switzerland. RESULTS: The response rate was 69.6% (558). For the prevention of fatal and non-fatal myocardial infarction the mean ratings of effectiveness of lipid lowering drugs were 0.45 (95% confidence interval 0.21 to 0.69) and 1.39 (1.09 to 1.68) scale points lower when the reduction of absolute risk or number needed to treat were reported instead of the relative risk reduction (both P < 0.001). Physicians receiving trial results for identical end points in form of absolute reduction of risk or number needed to treat were less inclined to treat hypercholesterolaemia (both P < 0.001). CONCLUSIONS: Physicians' views of the effectiveness of lipid lowering drugs and the decision to prescribe such drugs is affected by the predominant use of reduction of relative risk in trial reports and advertisements.

Adult↗

Does routine ultrasound scanning improve outcome in pregnancy? Meta-analysis of various outcome measures.

OBJECTIVE: To evaluate the effectiveness of routine ultrasound scanning in pregnancy by a meta-analysis of various outcome measures. DESIGN: Meta-analysis of randomised controlled trials evaluating the effect of routine ultrasound scanning on perinatal mortality and morbidity. Live birth rate (that is, live births per pregnancy) is included as a measure of pregnancy outcome in addition to the conventional perinatal mortality. SUBJECTS: 15,935 pregnancies (7992 in which routine ultrasound scanning was used and 7943 controls with selective scanning) from four randomised controlled trials. MAIN OUTCOME MEASURES: Perinatal mortality, live birth rate, rate of miscarriage, Apgar score < 7 at 1 minute, and number of induced labours. RESULTS: The live birth rate was identical in both screening and control groups (odds ratio = 0.99; 95% confidence interval 0.88 to 1.12) although the perinatal mortality was significantly lower in the group who had routine ultrasonography (0.64, 0.43 to 0.97). Differences in perinatal morbidity between the two groups as measured by the proportion of newborn babies with Apgar score < 7 at 1 minute were not significant (1.05; 0.93 to 1.19). CONCLUSION: Routine ultrasound scanning does not improve the outcome of pregnancy in terms of an increased number of live births or of reduced perinatal morbidity. Routine ultrasound scanning may be effective and useful as a screening for malformation. Its use for this purpose, however, should be made explicit and take into account the risk of false positive diagnosis in addition to ethical issues.

Abortion, Spontaneous↗