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Biomedical subjects

C Chastang

Publications and source records attributed to C Chastang.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Therapeutic benefit of a low dose of indapamide: results of a double-blind against placebo European controlled study].

Indapamide is a diuretic prescribed in the treatment of hypertension at the dosage of 2.5 mg per day. In accordance with international recommendations concerning the need to use low doses of antihypertensives, a new lower-dose form of indapamide has been developed to achieve the best safety/efficacy ratio by decreasing the incidence of hypokalemia. A new pharmaceutical sustained-release (SR) form was developed to give a smooth pharmacokinetic profile in comparison with the indapamide instant release (IR) form. The aim of this study was to determine the lowest new dosage of the SR form producing similar hypertensive efficacy as the LR form, and decreasing the percentage of patients with a serum potassium concentration below 3.4 mmol/l. This multicenter study was designed as a single-blind, run-in, placebo period of 1 month, followed by a double-blind, active treatment period of 2 months, using parallel groups: 285 patients with essential uncomplicated mild-to-moderate hypertension (95 mmHg < or = supine diastolic blood pressure (sDBP) < or = 114 mmHg) were included and randomly treated by either IR indapamide (2.5 mg) or SR indapamide (1.5, 2.0, 2.5 mg). After 2 months of active treatment, the one-way analysis of variance on the principal criterion (difference in sDBP between M2 and M0) revealed a significant treatment effect (p = 0.016). The mean drop in sDBP (+/- standard deviation) was 5.8 mmHg (+/- 8.6) after 2 months of placebo; 10.1 mmHg (+/- 7.0) after indapamide IR 2.5 mg; and 11.0 mmHg (+/- 9.4), 8.9 mmHg (+/- 9.4), and 10.5 mmHg (+/- 8.5) after indapamide SR 1.5 mg, 2 mg, and 2.5 mg, respectively. The difference between the placebo and indapamide treatment was significant (p < or = 0.05). No significant difference was detected between the various indapamide treatments, i.e., no difference between the IR and SR formulations, no difference between the various dosages of the SR form, and therefore no dose/effect relationship in the dose interval tested (SR 1.5, 2, and 2.5 mg). The incidence of patients with a serum potassium concentration less than 3.4 mmol/l was lower with indapamide SR 1.5 mg (11%) than with indapamide 2.5 mg, SR 2 mg, and SR 2.5 mg, respectively: 29%, 18% and 14%. These results show the interest of a low dose of indapamide in improving the safety while producing the same antihypertensive efficacy.

Adolescent↗
PubMed1995

An equivalence study of the safety and efficacy of a fixed-dose combination of perindopril with indapamide versus fixed-dose combinations of captopril with hydrochlorothiazide and enalapril with hydrochlorothiazide in the treatment of hypertension.

OBJECTIVE: The aim of this multicenter, randomly allocated, double-blind, parallel-group study was to evaluate the equivalence of three fixed-dose combination drugs in mild to moderate hypertension: perindopril + indapamide (4 + 1.25 mg), captopril + hydrochlorothiazide (50 + 25 mg) and enalapril + hydrochlorothiazide (20 + 12.5 mg). PATIENTS AND METHODS: After a single-blind, 4-week, placebo run-in phase, 527 patients (mean +/- SD age 54.5 +/- 1.2 years) with a supine diastolic blood pressure of 101.2-101.7 mmHg were randomly assigned to one of the three treatments for 8 weeks. The main evaluation criteria were diastolic blood pressure and serum potassium concentration. Equivalence was assessed on an intention-to-treat basis, using Schuirmann's method, which involves performing two one-tailed statistical tests on the data. Thirty-five patients were withdrawn from the study but there were no differences between groups in the reasons for withdrawal. RESULTS: Diastolic blood pressure decreased by between 13.1 and 14.2 mmHg in the three groups. The 90% confidence intervals for the differences between perindopril + indapamide and the other treatments were -1.1, +1.7 mmHg for captopril + hydrochlorothiazide and -0.4, +2.6 mmHg for enalapril + hydrochlorothiazide. Schuirmann's test was highly statistically significant (P<0.001 for perindopril + indapamide versus captopril + hydrochlorothiazide; P<0.002 for perindopril + indapamide versus enalapril + hydrochlorothiazide), so that the two one-sided hypotheses that the treatments were not equivalent were rejected at the nominal level of alpha = 0.05. Similarly, the safety of the treatments was equivalent in terms of serum potassium. The 90% confidence intervals of the differences between perindopril + indapamide and the other treatments were -8.7, -1.6% for captopril + hydrochlorothiazide (P = 0.004) and -1.5, +2.7% for enalapril + hydrochlorothiazide (P<0.001). CONCLUSIONS: We conclude that the safety and efficacy of perindopril + indapamide, captopril + hydrochlorothiazide and enalapril + hydrochlorothiazide were equivalent after 8 weeks of treatment in patients with mild to moderate hypertension.

Adolescent↗
PubMed1994

Subcutaneous heparin treatment increases survival in small cell lung cancer. "Petites Cellules" Group.

BACKGROUND: A positive influence of anticoagulant treatment in small cell lung cancer (SCLC) has been suggested by experimental and clinical data. METHODS: In a multicenter clinical trial, 277 patients with SCLC were randomized either to receive or not to receive subcutaneous heparin injections for 5 weeks at effective doses, which were monitored by blood coagulation tests. All patients received one of the two chemotherapy regimens studied in this trial, for eight courses in the case of patients with complete or partial response, and subsequently were randomized to receive delayed thoracic radiotherapy after these eight courses. RESULTS: In comparison to the 139 patients who did not receive heparin, the 138 patients who received anticoagulant treatment obtained better complete response rates (37% vs. 23%, P = 0.004), better median survival (317 days vs. 261 days, P = 0.01), and better survival rates at 1, 2, and 3 years (40% vs. 30%, 11% vs. 9% and 9% vs. 6%, respectively). At subgroups analysis, the results on survival were obtained for limited forms (P = 0.03) but not for extensive diseases (P = 0.31). No important bleeding or thrombocytopenia was related to heparin treatment. CONCLUSIONS: These results confirm the value of anticoagulant treatment in SCLC, already suspected for warfarin and now proven for heparin, but the modes of administration and the biologic explanations for this activity still warrant further investigation.

Aged↗
PubMed1994

Randomised trial of preventive nasal ventilation in Duchenne muscular dystrophy. French Multicentre Cooperative Group on Home Mechanical Ventilation Assistance in Duchenne de Boulogne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy in children. Paralysis of respiratory muscles causes a decrease in forced vital capacity (FVC) from age 12 years, and death occurs between 20 and 25 years old and is usually related to respiratory insufficiency. Uncontrolled studies suggest that early home use of nasal intermittent positive-pressure ventilation (NIPPV) in DMD patients free of respiratory failure could limit progression of the restrictive syndrome and therefore improve survival because efficacy of preventive NIPPV has not been demonstrated in a controlled trial, we undertook a randomised multicentre study in which 70 patients with DMD were included. Patients were free of daytime respiratory failure and FVC was between 20 and 50% of predicted values. At least 6 h of nocturnal NIPPV (n = 35) was compared with conventional treatment (n = 35). During a mean follow-up of 52 months, 10 patients died, 8 in the NIPPV group and 2 in the control group (p = 0.05, log-rank test). No differences were observed between the two groups for occurrence of hypercapnia, decrease of FVC below 20% of initial values, or use of necessary mechanical ventilation. Preventive NIPPV did not improve respiratory handicap and reduced survival of DMD patients. Use of NIPPV for preventive purposes should be avoided in patients with FVC between 20 and 50% of predicted values.

Adolescent↗
PubMed1994

A microcomputer program for the design and analysis of phase II cancer clinical trials with two group sequential methods, the sequential probability ratio test, and the triangular test.

We developed an interactive and menu-driven computer program to help investigators design and analyze phase II cancer clinical trials with a group sequential method, namely the sequential probability ratio test or the triangular test. Based on the values selected for the parameters of the trial, the "Design" option allows one to obtain, using simulations, the statistical properties (type I and II error rates and the probability that the test accepts the hypothesis of inefficacy under 21 different assumptions) and the average sample size (under the same assumptions) of the selected test. The "Analysis" option (i) computes, at each analysis, the two statistics V and Z on which the sequential method is based and plots the sample path from the number of successes observed, and (ii), using asymptotic properties, gives the significance level of the test and a point estimate (with its 95% confidence interval) of the parameter of interest at the last analysis.

Algorithms↗
PubMed1994

A comparison of methods for phase II cancer clinical trials: advantages of the triangular test, a group sequential method.

In cancer, the purpose of Phase II studies is to determine whether the response rate p to a new treatment is greater than a prespecified value p0, defined as the largest response rate for which Phase III studies are not worthwhile. It concerns, for example, determining whether the response rate to a new drug is greater than 20%. The main problem is of a decision making nature, and amounts to the comparison of an observed percentage with a theoretical percentage. One way of resolving it is to perform a single statistical analysis after the inclusion of a predetermined number of patients N, but it is not always possible because of high values of N. Furthermore, this approach presents ethical problems when elements in favor of inefficacy or efficacy are available early in the trial. For these reasons, several authors have developed methods which allow to perform repeated analyses and possibly to reach an early conclusion of the study: two-stage, multistage, sequential and group sequential methods. This article considers the main decision making methods proposed in the literature for Phase II studies in oncology. The bibliographic study, which highlights the interest of using group sequential methods, and especially the Triangular Test, is confirmed by a comparative study of the statistical properties of the different methods.

Clinical Trials, Phase II as Topic↗
PubMed1994

Vinorelbine versus vinorelbine plus cisplatin in advanced non-small cell lung cancer: a randomized trial.

PURPOSE: The purpose of the study was to assess the possible benefit of the combination vinorelbine (NVB)-cisplatin (DDP) in comparison with NVB alone in advanced non-small cell lung cancer (NSCLC), not treated previously. It also involved confirmation of the efficacy of vinorelbine as monotherapy. PATIENTS AND METHODS: In this phase III trial, 231 eligible patients were stratified by centre and randomized to receive either NVB alone, 30 mg/m2/week or the combination of NVB 30 mg/m2/week and DDP 80 mg/m2/3 weeks. Patients were to be treated for a minimum of 6 weeks, with the first response assessment performed 9 weeks after the beginning of treatment. RESULTS: The two groups differed in terms of objective response rates (16% and 43%, respectively, p = 0.0001) and median time to progression (10 weeks and 20 weeks, p = 0.0001). However, the difference was not significant for median survival time (32 weeks, 33 weeks, p = 0.48). The addition of DDP resulted in an increase in toxicity, in particular renal, hematologic, neurologic and emetic. This toxicity led to treatment discontinuation in 8% and 21% of patients, respectively. Respectively 3% and 13% of patients stopped treatment early during objective response (toxicity or refusal). CONCLUSIONS: The NVB-DDP combination increased objective response rates and time to progression in comparison with NVB alone, but did not influence the survival of patients. The activity of NVB in the treatment of advanced NSCLC was confirmed.

Antineoplastic Agents↗
PubMed1994

Salmeterol compared with slow-release terbutaline in nocturnal asthma. A multicenter, randomized, double-blind, double-dummy, sequential clinical trial. French Multicenter Study Group.

The aim of the multicenter, randomized, double-blind, double-dummy, parallel-group clinical trial with a 2-week treatment period was to compare the efficacy and safety of salmeterol (50 micrograms twice daily) with slow-release (SR) terbutaline (5 mg orally, twice daily) in nocturnal asthma. A total of 159 asthmatic adults (FEV, 50-90% of predicted value; sex ratio: 0.87) with at least two nocturnal awakenings during a 7-d run-in period was included in the study. Patients were centrally randomized with a national computer network (Minitel). The main variable (number of awakening-free nights during the last week of treatment) was analyzed according to a sequential method with the one-sided triangular test. The number of awakening-free nights (+/- SD) was significantly higher in the salmeterol group: 5.3 +/- 2.4 vs 4.6 +/- 2.3 (P = 0.006). Salmeterol was significantly more effective than SR-terbutaline in the following factors: number of patients without any awakening during the last week of treatment (50% vs 27%, P = 0.003), mean morning PEF (351 +/- 109 l/min-1 vs 332 +/- 105 l/min-1, P = 0.04), PEF diurnal variation 6 +/- 10% vs 11 +/- 12%, P = 0.01), overall assessment of efficacy by the patient and the investigator (P = 0.001 and 0.005, respectively), and daily rescue salbutamol intakes (P = 0.004). In the salmeterol group, significantly fewer patients reported adverse events (16% vs 29%, P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Chronic diffuse infiltrative lung disease: determination of the diagnostic value of clinical data, chest radiography, and CT and Bayesian analysis.

PURPOSE: To assess the value of clinical, chest radiographic, and computed tomographic (CT) findings in classifying chronic diffuse infiltrative lung disease (CDILD) MATERIALS AND METHODS: Two samples from the same population were consecutively studied: the training set (group A, n = 208) for the development of the decision aid and the test set (group B, n = 100) for validation. Computer-aided diagnoses were made with a Bayesian model that assigned to each patient diagnostic probabilities based on clinical, radiographic, or CT variables. RESULTS: In group A, a correct diagnosis based on clinical data was obtained in 29% of cases; radiography, 9%; and CT, 36%. This increased to 54% when clinical and radiographic variables were combined (P < .0001) and to 80% when data from all three were analyzed together (P < .0001). With prior and conditional probabilities determined from group A, the frequency of correct diagnosis in group B was 27% with clinical data, which increased to 53% (P < .0001) with radiographic findings and 61% after including CT data (P = .07). CONCLUSION: CT can help determine the specific diagnosis in patients with CDILD.

Bayes Theorem↗
PubMed1994

Severe community-acquired pneumonia. Etiology, epidemiology, and prognosis factors. French Study Group for Community-Acquired Pneumonia in the Intensive Care Unit.

A prospective study of 132 patients with severe community-acquired pneumonia (CAP) treated in the ICU was carried out to determine the causative agents, the value of the clinical, biological, and radiologic features in predicting the etiology, and to define prognostic factors. The study group included 98 men and 34 women (mean age: 58 +/- 18 years). The most frequent underlying condition was COPD (51 patients, 39 percent). On admission, 35 patients were in shock, 71 were mentally confused, and 81 (61 percent) required mechanical ventilation during their hospitalization. The clinical, laboratory, and radiologic parameters were of little value for predicting the etiology in patients with severe CAP. An etiologic diagnosis was made in 95 (72 percent) patients. The most frequent pathogens were Streptococcus pneumoniae (43 cases [45 percent]), Gram-negative bacilli (14 cases [15 percent]), and Haemophilus influenzae (14 cases [15 percent]) Mortality was 24 percent. It was significantly associated with a age more than 60 years, septic shock, impairment of alertness, mechanical ventilation requirement, bacteremic pneumonia, and S pneumoniae or Enterobacteriaceae as the causes of the pneumonia. Recommendations for antibiotic chemotherapy in patients with severe CAP admitted to the ICU are included.

Community-Acquired Infections↗
PubMed1994

Treatment of newly diagnosed acute promyelocytic leukemia (APL) by a combination of all-trans retinoic acid (ATRA) and chemotherapy. French APL Group.

All-trans retinoic acid (ATRA) is very effective in newly diagnosed acute promyelocytic leukemia (APL), yielding remission (CR) rates of 80 to 90%. However, it is associated with a rapid rise in WBC in some patients, with potentially fatal ATRA syndrome. Furthermore, most patients relapse with maintenance therapy using ATRA alone or low-dose chemotherapy. The French APL group thus designed a treatment approach with ATRA followed by intensive chemotherapy. The latter was administered after CR achievement with ATRA, or was rapidly added to ATRA in the case of rapid rise in leukocyte counts. This combined approach, in a pilot study and in a randomized trial, proved superior to intensive chemotherapy alone, by slightly increasing the CR rate but more importantly by reducing the relapse rate. The French group (and other European groups) are now testing in a new randomized trial the better timing of ATRA and chemotherapy administration (ATRA followed by chemotherapy or ATRA plus chemotherapy), and the role (after an intensive consolidation) of maintenance treatment with intermittent ATRA, continuous low-dose chemotherapy, or both.

Aged↗
PubMed1994

[Estimation by the Hui and Walter method of the sensitivity and specificity of a diagnostic test in the absence of a reference test: results of a simulation study].

Hui and Walter proposed an approach to directly estimate the parameters of diagnostic tests (sensitivity and specificity for dichotomous tests) and the prevalence of the disease in the absence of a reference error-free test, and without imposing any constraint. We performed a simulation study to investigate the finite-sample properties of the proposed estimators for the situation of three tests. We obtained the following results: i) in screening situations (prevalence < or = 0.10), severe bias and poor precision in the parameter estimates occur and this approach should not be used except for studies with a very large sample size (n > or = 2500); ii) in diagnostic situations (prevalence > or = 0.30), the approach is much more reliable and very little or no bias occurs even for small sample sizes (n = 50, 100), except when both the prevalence is very high (p > or = 0.90) and the performances of the tests mediocre (sensitivity and specificity lower than 0.80).

Algorithms↗
PubMed1994

Prognostic value of early computed tomographic scans in severe acute pancreatitis. French Association for Surgical Research.

BACKGROUND: The prognostic value of computed tomographic (CT) scans in differentiating mild from severe forms of acute pancreatitis is well established. Nonetheless, in patients with a severe form of the disease, some will have a relatively uneventful course while others will have severe complications. This prospective, multicenter study was done to evaluate the prognostic value of early CT scan in a homogenous group of patients with a first attack of severe acute pancreatitis. STUDY DESIGN: Dynamic CT scans were performed within 48 hours after admission. A standardized form was completed for each CT scan, recording the following data: abnormal enhancement of the pancreas itself, characteristics of extrapancreatic collections, and visualization of the portal and splenic veins. Statistical analysis was based on the log rank test and Cox's model and used death and abscess occurrence as the two end points. RESULTS: Two hundred twenty-eight patients from 46 centers were included in the study. The median Ranson and Imrie scores were 3 and 4, respectively. Forty-seven patients died and 72 had an abscess. The CT scan findings indicating an increase in mortality rate were nonenhancement of the neck of the pancreas (p = 0.04) and extrapancreatic collections within the left (p = 0.001) and right (p = 0.02) pararenal posterior spaces. The risk of abscess increased when there was nonvisualization of the splenic vein (p = 0.0001), in the presence of extrapancreatic collections in the right pararenal posterior space (p = 0.03) and when the extrapancreatic collections were heterogenous (p = 0.003). CONCLUSIONS: This study demonstrated that the location of extrapancreatic collections and nonvisualization of the splenic and portal veins on CT scans were not previously recognized prognostic factors of complicated outcome in patients with severe acute pancreatitis.

Abdominal Abscess↗
PubMed1994

An ongoing randomized study of neoadjuvant chemotherapy in resectable non-small cell lung cancer.

The purpose of this trial is to assess the possible benefit of neoadjuvant chemotherapy before surgery in patients with operable non-small cell lung cancer. Patients with operable stages I (except T 1N0), II, or IIIA disease are eligible for this ongoing trial. Patients are randomized into two arms. Surgery is performed first in group I; patients found to have T3 tumors or N2 lymph nodes are given postoperative radiotherapy. Group 2 patients start with two cycles of chemotherapy; following surgery, two more cycles are administered in responder patients and, as in group I, patients with T3 tumors or N2 lymph nodes are given radiotherapy. Chemotherapy is the MIP protocol: mitomycin 6 mg/m2 day I, ifosfamide 1.5 g/m2 days 1 to 3, cisplatin 30 mg/m2 days I to 3, and mesna 1,200 mg/m2 days 1 to 3. One hundred fifty patients were enrolled between June 1991 and September 1993. By the time this report was prepared, 117 patients had completed all assigned treatment, 63 in group I and 54 in group 2. There were two ineligible patients, one in each group. Forty-nine patients underwent thoracotomy in the chemotherapy-surgery group and 62 in the surgery-only group. There was only one progression after two cycles of chemotherapy. Rates of exploratory and incomplete surgery were 17% in group I and 12% in group 2. The trial is ongoing.

Adult↗
PubMed1993

No effect of an antiaggregant treatment with aspirin in small cell lung cancer treated with CCAVP16 chemotherapy. Results from a randomized clinical trial of 303 patients. The "Petites Cellules" Group.

BACKGROUND: Experimental, and more recently, clinical data have suggested the influence of hemostasis in the spread of malignant disease. METHODS: To complete research in this type of coagulation and cancer, a multicentric randomized clinical trial was performed, including 303 patients with small cell lung cancer (SCLC), treated by the addition of aspirin at 1 g/day (a dosage at which aspirin is considered to be a platelet aggregation inhibitor) to combined chemotherapy. RESULTS: Survival was not increased in the aspirin-treated group (P = 0.90). The analysis according to the extent of disease (limited or extensive disease) did not modify that conclusion. CONCLUSIONS: This result does not confirm the hypothesis that, in SCLC, aspirin (a platelet aggregation inhibitor) reduces metastasis formation and local tumor thrombogenesis.

Adult↗
PubMed1993

Superior vena cava syndrome in small-cell lung cancer.

BACKGROUND: The aim of this study was to analyze the features of the superior vena cava syndrome (SVCS) as initial characteristics in small-cell lung cancer: incidence, dissemination of disease, diagnostic procedures, efficacy and toxic effects of chemotherapy, and median survival in patients with SVCS. METHODS: In a prospective series of 724 patients with biopsy-proved small-cell lung cancer seen during a 6-year period, we reviewed data from patients who also had SVCS. RESULTS: The incidence of SVCS was 87 of 724 at the time of diagnosis. Initial emergency radiation therapy was not used in these patients. Diagnostic procedures in these patients were not associated with mortality. Rapid initiation of intensive chemotherapy, often with heparin therapy, resulted in complete or partial responses in 81% and no response in 12%; data were not evaluable in 7%. Two of these 87 patients died of aplasia within 4 weeks of chemotherapy. Median survival was not significantly different in the patients with SVCS (median, 42 weeks) and without SVCS (median, 40 weeks). A significant increase in initial brain metastases at the time of diagnosis was observed in patients with SVCS (22% vs 11%). CONCLUSIONS: Intensive chemotherapy is the first line of therapy in small-cell lung cancer. Histologic diagnostic procedures must be performed in patients with SVCS to adapt the treatment to the underlying cause. Initial emergency radiotherapy, before diagnosis or chemotherapy, does not seem to be useful in these patients. Computed tomography of the brain should be performed routinely in patients with SVCS, and prophylactic brain irradiation could be helpful in such patients. Apparently SVCS is not a poor prognostic factor in treated small-cell lung cancer.

Adult↗