Hemodynamic and cardiac correlates of different hemodialysis regimes: the National Cooperative Dialysis Study.
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This report describes the organization and results of the European Cooperative Study Group trial of intravenous recombinant tissue-type plasminogen activator (rt-PA) plus conservative therapy versus intravenous rt-PA plus immediate intervention (coronary angiography with a view to angioplasty) in patients with acute myocardial infarction. One hundred eighty-four patients were allocated to noninvasive treatment and 183 to an invasive/intervention policy. Immediate angioplasty was attempted in 168 patients (92%) of the latter group. The trial was terminated after a data review by the ethical monitoring committee showed no benefit in the "invasive" group in terms of enzymatic infarct size or left ventricular function, and a trend (although not statistically significant) toward increased mortality in the intervention group. Analysis of coronary patency and residual stenosis at the time of discharge showed no difference in patency rate, but less residual stenosis in the intervention group. The study differed from the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) and the Thrombolysis in Myocardial Infarction Phase-IIB (TIMI-IIB) trials in that the philosophy of intervention to produce the earliest and most complete reperfusion resulted in a high incidence of angioplasty procedures in vessels not yet reperfused. The reasons for the failure of this philosophy to show benefit are uncertain, but may include an increased risk of reocclusion after angioplasty or reperfusion damage, or both.
The aim of this study was to compare the renal effects of angiotensin converting enzyme (ACE) inhibition with calcium channel blockade in a model combining genetic hypertension with diabetes. Streptozotocin diabetes was induced in spontaneously hypertensive rats (SHR). The animals were then randomized to receive no treatment, the ACE inhibitor, perindopril, or the dihydropyridine calcium antagonist lacidipine. Body weight, systolic blood pressure, glycemic control, renal function, and albumin excretion rate (AER) were assessed serially over the 32-week study period. At week 32 the animals were killed and glomerular volume was measured. Both antihypertensive regimens significantly reduced systolic blood pressure in diabetic SHR. There was no significant difference in glycemic control, serum creatinine, or glomerular filtration rate among the three groups at week 32. The ACE inhibitor perindopril significantly reduced AER and glomerular hypertrophy over the 32 weeks, whereas the calcium antagonist lacidipine failed to reduce AER or glomerular hypertrophy. Thus, in contrast to the effects of ACE inhibition, calcium channel blockade with lacidipine, despite significantly reducing blood pressure, failed to reduce renal injury in this model. These results support the hypothesis that antihypertensive regimens may differ in their capacity to protect the diabetic kidney, despite similar effects on systemic blood pressure.
We treated 99 female patients suffering from recurrent urinary infections with either 1 gm. methenamine hippurate every 12 hours or 50 mg. nitrofurantoin every 12 hours for intervals of up to 1 year. Monthly microbiological and clinical surveillance was done. Both treatments were effective in reducing the incidence of symptomatic attacks, with nitrofurantoin being more effective. The protective effect of prophylaxis continued after treatment had stopped, suggesting that a permanent beneficial action had been produced. Especially during the first month of treatment methenamine hippurate was tolerated better than nitrofurantoin: 28 per cent discontinued therapy with the latter owing to nausea.
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The nonsteroidal antiinflammatory drug (NSAID) indomethacin has been shown to increase blood pressure in normotensive individuals. The effect of other NSAID on blood pressure has not been as well studied. We evaluated the effects of ibuprofen, an NSAID currently available without a prescription, on 24-hour ambulatory blood pressure in ten young, healthy, normotensive women. Using a randomized, crossover, double-blind design, subjects received ibuprofen 800 mg and a placebo identical in appearance to ibuprofen three times a day for eight days with a washout period between regimens. Subjects were instructed to follow a no-added salt diet during the study. Twenty-four-hour blood pressure monitoring and 24-hour urine collection for prostaglandin E2, creatinine, and sodium were performed on days 1 and 8 of each study week. Tablet counts and a 40 percent reduction in urinary prostaglandin E2 documented compliance with ibuprofen. Ibuprofen had no significant effect on systolic or diastolic blood pressure at any hour during the 24-hour period. Mean blood pressure for the 24-hour period was 112/73 and 111/73 mm Hg on day 1 and 111/73 and 112/73 mm Hg on day 8 for placebo and ibuprofen, respectively. We conclude that ibuprofen at doses as high as 2400 mg/d for up to seven days has no effect on blood pressure in normotensive women. Further studies are needed in hypertensive subjects.
Growth and protein status were examined in Thoroughbred foals and yearlings offered pasture supplements with different crude protein contents and amino acid compositions. Both supplements contained 3.0 Mcal/kg DM, 10% corn oil, 1.4% calcium, and three sources of fiber. The control supplement contained 14% CP and 22% soybean meal, whereas the experimental supplement contained 9% CP and 3% soybean meal and was fortified with 0.6% lysine and 0.4% threonine. Mares and foals were fed twice daily (0700 and 1400) and kept on 12.14-hectare pastures (mixed grass and ladino clover) until weaning (6 mo). Weanlings continued on specified supplements and pastures for seven additional months. Physical measurements and blood samples were taken monthly for a period of 14 mo. Measurements included BW, ADG, body condition (BC), wither height, hip height, body length, girth, forearm length, front and hind cannon length, and carpus and fetlock circumference. Blood plasma analysis included total protein, albumin, creatinine, and urea nitrogen. Effect of diet and time were evaluated by analysis of variance with repeated measures. No differences (P > 0.05) were found in physical measurements between the control and Lys/Thr groups (ADG 0.7 +/- 0.02 kg/d, BC 4.9 +/- 0.05) for the observational period. Blood data also showed no difference (P > or = 0.05) for the period (albumin 2.9 +/- 0.03 g/dL, total protein 5.7 +/- 0.10 g/dL, creatinine 1.1 +/- 0.02 mg/dL). Differences in ADG between the control and experimental groups were observed in November (0.73 +/- 0.06 vs 0.91 +/- 0.04 kg/d, P = 0.01) and December (0.56 +/- 0.04 vs 0.67 +/- 0.06 kg/d, P = 0.07) and again in April (0.65 +/- 0.12 vs 0.86 +/- 0.06 kg/d, P = 0.06). These results suggest that the foals offered the Lys/Thr grew at the same or greater rates than foals on the control supplement. When a low-protein diet was fortified with the first two limiting amino acids, the protein was utilized more efficiently for growth and development. This study gives further insight into the role of protein quality during a foal's 1st yr of growth.
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Seventy-one heavy smokers who had failed in previous attempts to stop smoking participated in a randomized clinical trial to test the efficacy of clonidine as an aid in smoking cessation. The success rate in clonidine-treated subjects (verified by serum cotinine concentration) was more than twice that in the placebo-treated subjects. When the data were stratified by gender, a strong effect present in women was not apparent in men. After six months, cessation rates remained significantly higher among smokers treated with clonidine than those receiving placebo. The data also revealed an unexpectedly high prevalence (61%) of a history of major depression in this sample and a significant negative effect of such a history on cessation regardless of treatment. These findings, highly suggestive of an important role of clonidine in smoking cessation, warrant further studies to establish the long-term (greater than or equal to 12 months) efficacy of this drug and to replicate the association between nicotine dependence and depression.
BACKGROUND: An important issue in clinical practice is how to treat patients whose blood pressure does not respond to the first antihypertensive drug selected. OBJECTIVE: To analyze the antihypertensive response of patients who had failed to achieve their diastolic blood pressure goal (< 90 mm Hg at the end of 8 to 12 weeks of titration) with one of six randomly allocated drugs or placebo to the random allocation of an alternate drug. METHODS: We initially randomized 1292 men with diastolic blood pressure of 95 to 109 mm Hg to treatment with hydrochlorothiazide, atenolol, captopril, clonidine hydrochloride, diltiazem hydrochloride (sustained release), prazosin hydrochloride, or placebo. Of 410 men in whom initial treatment failed, 352 qualified for randomization to the alternate drug. RESULTS: Of the 352 patients, 173 (49.1%) achieved their goal diastolic blood pressure, in 133 (37.8%) the alternate drug failed, and 46 (13.1%) left the study for various reasons. Overall response rates were as follows: diltiazem, 63%; clonidine, 59%; prazosin, 47%; hydrochlorothiazide, 46%; atenolol, 41%; and captopril, 37%. The best response rate for patients in whom hydrochlorothiazide failed was achieved with diltiazem (70%); after atenolol failure, clonidine (86%); after captopril failure, prazosin (54%); after clonidine failure, diltiazem (100%); after diltiazem failure, captopril (67%); and after prazosin failure, clonidine (53%). The combined response rate for patients initially randomized to an active treatment was 76.0%, which is similar to that achieved by the combination of two drugs in previous studies. CONCLUSIONS: We conclude that sequential single-drug therapy is a rational approach for treatment of hypertension in patients in whom initial drug therapy has failed.
BACKGROUND: Randomised controlled trials (RCTs) are the most important method of evaluating new treatments and treatment policies. Despite this, there are relatively few large pragmatic RCTs in psychiatry. AIMS: To explore the main advantages of large pragmatic RCTs and the obstacles to performing them in psychiatry. METHOD: A narrative review of literature on pragmatic RCTs with examples drawn from psychiatry and other medical specialities. RESULTS: Obstacles to performing pragmatic RCTs in psychiatry include the complexity of psychiatric interventions, the complexity of outcomes used in psychiatry and the difficulties of blinding subjects and investigators to some psychiatric interventions. CONCLUSIONS: Researchers need to frame questions in a form that is relevant to clinicians and to convince clinicians to cooperate in simple large pragmatic trials.
The policy implications of a 1996 national nursing survey on the allocation of publication credit form of this paper. An earlier article (Butler & Ginn, 1997) describes and analyzes the outcome of the survey; the purpose here is to draw on that analysis, and on the relevant literature, to propose a starting place for discussion within the specialty of oncology and the nursing profession regarding assignment of credit for various contributions to collaborative scholarly work. After identifying the growing need for such a discussion and briefly highlighting the findings of the survey, the paper goes on to examine unacceptable practices in scholarly work and identify issues which should be resolved before collaborative work is undertaken. The final portion of the paper makes tentative suggestions as to principles and guidelines which might be applied to avoid disputes about the value of different contributions to a collaborative project. It is emphasized that the intention is not to advocate acceptance of the guidelines suggested here, but to create sufficient interest so that an approach to allocation of publication credit may be developed which will be consistent and relevant to the needs of the nursing profession.
In several test model systems using spontaneous metastasizing experimental tumours, convincing data indicate the importance of the tumour burden left after surgery for the efficacy of the combination of surgery and chemotherapy. Early removal of the primary tumour by radical surgery for cure seems to improve the conditions for chemotherapy. Since 1979, in nine different departments of thoracic surgery, patients with small-cell carcinoma of the lung (SCCL) have been randomized after surgery for cure to receive a new sequential intermittent polychemotherapy (sq.CT) of 3 different alternating drug combinations given intermittently over 1 year, or one 4-drug combination chemotherapy (CT) given intermittently over 3 years. The calculation of their life table curves at 1 August 1984 indicated an improvement in the 4-year survival rate of 23 patients receiving sq.CT to about 50%, compared with a survival rate of about 30% for 29 patients receiving CT. The number of patients is still too small for firm conclusions to be drawn, but it is concluded that surgery for SCCL seems to be an advisable measure for the efficacy of aggressive intermittent long-term polychemotherapy. However, this can only be proved in large cooperative studies.
Therapeutic trials aim at comparing the effectiveness of two therapeutic attitudes. The problems involved are considered: comparability requirements of the groups, assured by randomization, which raises ethical questions. The need of a "sufficient" number of subjects, often imposing cooperative trials, is then discussed. Finally, it is necessary to define the disease and patients, the therapeutic possibilities, and judgement criteria.