PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “multicenter study”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1991

Quality control in antimicrobial disk susceptibility testing: a Belgian multicenter study.

A Belgian multicenter trial was conducted to evaluate problems encountered with quality control results of antimicrobial disk susceptibility testing and to compare the performance of BBL disks and Rosco tablets. Over a period of four weeks 18 laboratories daily tested three reference strains against eight antibiotics. A standardised method was used by all participants. For all results together 10.4% and 7.3% of the measurements with BBL disks and Rosco tablets, respectively, were outside the recommended range. Major problems were observed for some specific strain-antibiotic combinations. Standard deviations were similar for both systems; their precision was comparable. The results suggest that cooperation between manufacturers and some reference laboratories could be improved in order to establish optimal quality control limits.

Anti-Bacterial Agents↗
PubMed1985

Conference on insulin pump therapy in diabetes. Multicenter study of effect on microvascular disease. The Central Biochemistry Laboratory in the Multicenter Kroc Study. Problems and proposals.

The advantages of a multicenter trial can easily be lost if results from individual centers cannot be safely combined for statistical analysis. One objective of the Kroc Study was to develop methods that would allow valid amalgamation of results from laboratories at the six clinical centers and a central biochemical laboratory at the University of Newcastle upon Tyne. Responsibilities of the local laboratories, in addition to measurement of plasma glucose, creatinine, and glycosylated hemoglobin, were to obtain and prepare samples for measurement of plasma glucose, glycosylated hemoglobin, and serum lipids at the central laboratory, of C-peptide at the University of Chicago, and to collect and prepare samples for measurement of urinary albumin excretion at Guy's Hospital. The central laboratory was additionally to provide a system to ensure the comparability of plasma glucose determinations between and within centers, and to advise on common procedures for sample handling. Major problems were encountered with sample labeling, dispatch, and transport to the central laboratory. Although central determinations of plasma glucose and serum lipids were still possible in transported specimens, central assay of glycosylated hemoglobin proved inaccurate and useless. Compliance with the plasma glucose quality control program was variable among centers. Although the difference between the centers recording the highest and lowest values was 24.6% of the mean estimate of plasma glucose level, correlation between local and central plasma glucose determinations was good (r = 0.99, see pages 22-26).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMedDate not supplied

[The recurrence of duodenal ulcer in patients undergoing treatment with ranitidine and placebo. A multicenter study].

This randomised, double-blind multicenter study was conducted in order to evaluate the long-term effect (one year) of 150 mg ranitidine vs placebo in 51 patients with healed duodenal ulcer. Seventeen patients had ulcer recurrence at the end of follow-up, one among the 24 patients that received ranitidine and 16 among the 27 patients that received placebo (p = 0.00009). No side effects was detected. Our results support the usefulness of a one-year maintenance therapy with 150 mg ranitidine.

Adult↗
PubMed1992

Endoscopic release of the carpal tunnel: a randomized prospective multicenter study.

A 10-center randomized prospective multicenter study of endoscopic release of the carpal tunnel was carried out. Surgery was performed with a new device for transecting the transverse carpal ligament while control hands were treated with conventional open surgery. There were 122 patients in the study; 25 had carpal tunnel surgery on both hands and 97 had surgery on one hand. Of the surgical procedures, 65 were in the control group and 82 were in the device group. The endoscopic device was coupled to a fiberoptic light and a video camera. A trigger-activated blade was used to incise the transverse carpal ligament. After surgery, the best predictors of return to work and to activities of daily living were strength and tenderness variables. For patients in the device group with one affected hand, the median time for return to work was 21 1/2 days less than that for the control group. Two patients treated with the endoscopic device required reoperation by open surgical decompression; only one of these had incomplete release with the device. Two patients in the device group experienced transient ulnar neurapraxia.

Activities of Daily Living↗
PubMed1992

[Clinical and prognostic significance of echocardiographic parameters in dilated cardiomyopathy: a prospective study on 225 patients. The Italian Multicenter Study of Cardiomyopathies Group].

To assess the prognostic role of echocardiographic indexes and their relation to clinical conditions, 225 patients with dilated cardiomyopathy were studied prospectively. All cases had a normal coronary angiogram and non specific endomyocardial biopsy findings. 163 men (72.4%) and 62 women (27.6%), mean age 41.5 +/- 12.3 (range 8-61), were studied. Clinical, electrocardiographic and echocardiographic parameters, normalized for body surface area, were tested according to NYHA class and presence of segmental or diffuse wall motion abnormalities. One hundred-four patients were in NYHA class I-IIa, 94 were in class IIb-III and 27 were in class IV. Left ventricular end systolic diameter index, right ventricular end diastolic diameter index, left atrial diameter index, left ventricular fractional shortening and ejection fraction, and radius to wall thickness ratio were significantly more impaired in patients with more severe symptoms. Twenty-eight patients (13%) showed segmental wall motion abnormalities and had smaller left ventricular end systolic and left atrial diameter index and higher left ventricular fractional shortening and ejection fraction. During a mean follow up of 23 +/- 15 months (range 1-67 months), 25 patients (11.1%) died from cardiac causes and 16 (7.1%) underwent heart transplant because of refractory heart failure. Prognostic evaluation was performed separately for cardiovascular mortality alone and for cardiac events (cardiovascular mortality and heart transplantation). At Cox multivariate analysis only right ventricular end diastolic diameter index (p < 0.005) predicted cardiovascular mortality, while left atrial diameter index (p < 0.001), right ventricular end diastolic diameter index (p < 0.01) and left ventricular ejection fraction (p < 0.05) were significant independent predictors of cardiac events.

Adolescent↗
PubMed1995

The efficacy of cyclosporine A in adult nephrotic syndrome with minimal change disease and focal-segmental glomerulosclerosis: a multicenter study in Korea.

A multicenter prospective study conducted in four university hospitals in Korea investigated the efficacy and tolerance of cyclosporine A (CyA, Sandimmun) in 30 patients with adult nephrotic syndrome [25 patients with minimal change disease (MCD) and 5 with focal-segmental glomerulosclerosis (FSGS)]. After a 6-week washout period, CyA 5 mg/kg/day and prednisolone 10 mg/day were administered for up to 8 months, depending on responses to CyA. The rate of relapse after withdrawal of CyA was assessed up to 10 months. Of the 30 patients enrolled, 3 withdrew prematurely due to adverse events. Of the 27 patients who completed the study, 22 had MCD and 5 had FSGS. The prior steroid responses of these patients were 19 steroid-dependent (SD), 4 frequent-relapser (FR) and 4 steroid-resistant (SR) type. High rates of complete remission were obtained after CyA treatment in both MCD and FSGS patients, 86.4% (19/22) and 80% (4/5) respectively. Previous steroid responses did not affect the response to CyA; complete remission was obtained in 84.2% (16/19) of SD patients and in 75% (3/4) of SR patients. The mean (+/- SEM) duration of CyA treatment to attain complete remission in SD and SR patients was 3.8 (+/- 0.6) weeks and 10.7 (+/- 2.7) weeks, respectively (not significantly different). Tapering or withdrawal of CyA was followed by release of nephrotic syndrome in many patients, and the cumulative relapse rates at month 10 were 68.4% (13/19) in MCD patients and 50% (2/4) in FSGS patients. When considered according to prior steroid responses, the relapse rate was 73.3% (11/15) in SD patients and 50% (2/4) in SR patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Do steroid-eluting electrodes really have better performance than other state-of-the-art designs? The Italian Multicenter Study Group on Low Output Stimulation.

A multicenter study evaluated the performance of atrial and ventricular unipolar leads with porous steroid-eluting and platinized grooved electrodes. A total of 563 leads were implanted in 451 patients. These included 311 ventricular and 97 atrial steroid-eluting electrodes; and 112 ventricular and 43 atrial leads with platinized electrodes. Mean follow-up was > or = 1 year. At implant there were no significant differences in threshold parameters in either chamber. Chronically, however, the steroid-eluting lead consistently had significantly lower pacing thresholds in both chambers. For example, after 360 days implant, steroid-eluting electrodes had 0.23 +/- 0.10 msec ventricular thresholds at 0.8 V compared to 0.45 +/- 0.3 msec in the platinized group (P < 0.0001). In the atrium, the steroid-eluting lead's 6-month thresholds at 0.8 V were 0.15 +/- 0.06 msec compared to 0.9 +/- 0.8 msec for the platinized electrode (P < 0.01). The chronic ventricular QRS amplitudes were significantly greater for the steroid-eluting electrode (P < 0.0005). There were no significant differences in atrial sensing and no incidence of atrial undersensing in the study. The low and consistent thresholds of the steroid-eluting electrodes would have permitted pacing in the ventricle at < or = 2.5 V without compromising safety factor in 99.4% of the patients. The other 0.6% required 5 V temporarily. In the atrium, 100% of the patients could have been paced safely at reduced output. In spite of this, 63% of the implanters lacked the confidence to use reduced outputs.

Dexamethasone↗
PubMed1990

Comparison of different schedules of cytostatic intravesical instillations in patients with superficial bladder carcinoma: final evaluation of a prospective multicenter study with 419 patients.

In a prospective multicenter study we compared the value of various protocols of mitomycin C and doxorubicin instillation for the prevention of recurrent tumors in patients whose superficial bladder tumors (stages TA and T1) had been removed by transurethral resection. The 3-year and short-term instillation protocols were compared to each other and to a combination of 2 protocols. Evaluation after a mean followup of 28 months confirmed the value of cytostatic bladder instillation in preventing recurrence and progression of tumor in patients with superficial bladder carcinoma. There was no significant difference between the results of long-term and short-term prophylaxis; their combination achieved the best results. Doxorubicin and mitomycin yielded similar results; mitomycin was better tolerated.

Administration, Intravesical↗
PubMed1989

Arthroscopic drainage in septic arthritides of the knee: a multicenter study.

The results are presented of a multicenter study, conducted by questionnaire, of 46 cases of septic arthritis of the knee treated by arthroscopic drainage. This series consisted of 28 male and 16 female patients. Two patients had bilateral arthritides. The average follow-up period was 7.1 months. There were 11 cases of hematogenous arthritides, 15 arthritides secondary to puncture and infiltration, and 20 postoperative arthritides. There were 29 positive cultures (63%). After thorough articular lavage (average, 7 L) and prolonged antibiotic therapy (average 2 months) there were 36 bacteriological cures (78.3%), five failures (10.9%) due to persistent articular sepsis, and five recurrences of the infection (10.9%) after an initial remission. Five infectious flare-ups recovered secondarily, four recovered after repeated arthroscopy and one recovered after synovial centesis. The rate of cure after this second therapeutic attempt was 89.2%. Different parameters were used in evaluating the quality of the results: the etiology of the arthritis, the causal germ, and the delay prior to arthroscopy. Arthroscopic drainage is a method that has proved effective, with minimal morbidity, in attempts to cure septic arthritis of the knee, particularly in cases of hematogenous arthritis. This method could also be effective in total arthroplasties of septic knees.

Adolescent↗
PubMed1991

Treatment of angina pectoris with isosorbide-5-mononitrate. A multicenter study in general practice.

In this multicenter study 191 practitioners treated 532 patients with coronary artery disease and chronic stable angina pectoris by isosorbide-5-mononitrate (IS-5-MN), 20 mg 2-3 times daily. At the end of this period the frequency of anginal attacks was reduced by 83% and nitroglycerin consumption by 85.7% (p less than 0.0001). 40.1% of the patients categorized this treatment as very good, 28.6% as excellent and 23% as good. Serious adverse effects were observed in 2% of the patients and 6.4% of the patients discontinued treatment during the study because of inefficacy, infarction, death, or adverse effects. At the end of the study 90.2% of the patients were still on IS-5-MN. In conclusion, IS-5-MN is an effective treatment for patients with chronic stable angina pectoris. It is well tolerated, with minimal side effects.

Aged↗
PubMed1990

[Results of the West German multicenter study "Urological traumatology"].

The West German Multicenter Study on Urological Traumatology ran from April 1984 to December 1986. During this time, 19 departments of urology evenly scattered over the Federal Republic of Germany including Berlin (West) recorded and evaluated the data pertaining to a total of 385 patients (83% male, 17% female) with urogenital trauma. The distribution of the different mechanisms of injury demonstrates that 41% were due to traffic accidents; 13% each to accidents during sports and work; 8% to sexual activities; and 6% to violence. The trauma was slight in 40% of the cases, moderate in 21%, and severe in 39%. Of a total of 427 urogenital injuries, 27% were combined with intra-abdominal and 24% with pelvic injuries. Renal injuries were recorded in 51%, ruptures accounting for 49% of these and contusions for 48%. Hilar lesions were observed in 7%, with complete destruction of the organ occurred in 6% of these cases. In all, 76% of these traumas were treated conservatively, while 8% each required surgical reconstruction and nephrectomy. Traumatic lesions of the urinary bladder, urethra, penis, and scrotum including the testes and accessory organs were recorded in about 10% each. Macrohematuria was seen with 73% of renal, 83% of urinary bladder, and 73% or urethral injuries. Microhematuria occurred with 24%, 9%, and 13% of all cases, while no hematuria was ascertained in 3%, 5%, and 13% of renal, bladder and urethral traumas, respectively. The injury-related sensitivity of the different imaging methods was calculated at 95% for cystograms, 91% for retrograde urethrograms, and 83% for angiograms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Evaluating magnetic resonance tomography studies of the extremities--results of a multicenter study for evaluating nuclear magnetic resonance tomography].

MR examinations of the extremities occupy the first place in whole body examinations via MR. Highest accuracy quotas in this area with an average of 93.8% were obtained for tumours, trauma and necroses of the bones. These high accuracy quotas, however, were achieved only if sufficient preliminary information was available. Other statistically significant factors were found to be the field strength, the combined use of spin echo and fast imaging sequences and the use of the multislice technique.

Bone Neoplasms↗
PubMed1992

[Phase 2 clinical study of 99mTc-ECD--a multicenter study].

A phase 2 clinical study of a newly developed brain perfusion agent, 99mTc-ECD, was performed in 166 cases of cerebrovascular diseases and impairment of brain function to evaluate effectiveness, usefulness, optimum dose and optimum timing of imaging as a multi-center study involving 10 institutions in Japan. All cases were judged as no problems on safety and any side effects due to the administration of the compound were not observed. Out of 163 cases evaluated for the clinical usefulness, valuable information for clinical diagnosis was obtained in 160 cases (98.3%), and 154 cases (94.5%) were judged as "extremely useful" or "useful". Although SPECT imaging was possible from 5 min after injection, images obtained between 60 and 90 min after injection showed relatively better image quality in many cases. Regarding standard administration dose, 400 to 800 MBq were considered to be appropriate. 99mTc-ECD is considered to be a promising radiopharmaceutical as a brain perfusion agent.

Adolescent↗
PubMed1980

Safety and efficacy of a new synthetic burn dressing: a multicenter study.

A three-tiered, multicenter study evaluated the safety and efficacy of a new synthetic dressing for burn injuries. The first tier compared use of the test dressing with use of a conventional topical chemotherapeutic agent; the test dressing afforded greater patient comfort, equivalent control of bacterial growth, less frequent dressing change, and possibly faster reepithelialization. Drawbacks included difficulty of application, poor adherence during the first 24 hours after injury, frequent necessity to repair cracks and fissures, and inability to easily monitor burn wounds for bacterial growth. Subsequent tiers were noncomparative but included patients with more severe injuries. The test dressing may be useful in treating superficial and moderate second-degree burns of less than 20% of the total body surface area and possibly in treating iatrogenic "burn" wounds such as donor sites. Its use on third-degree burns is not recommended.

Acrylates↗
PubMed1987

[Induction of fetal lung maturation using ambroxol and betamethasone. Results of an open multicenter study].

In a randomized open multicenter study the results of antenatal prophylaxis against neonatal RDS by administration of betamethasone were compared with those obtained with the bromhexine VIII metabolite Ambroxol. Ambroxol was administered for a maximum of 5 days - 1000 mg in an infusion solution; betamethasone was injected intramuscularly in 2 daily doses of 8 mg. One of these two substances was given to 123 pregnant women for pulmonary maturation in the fetus, in accordance with a randomization plan. The patients were either being treated for premature labor or pregnancy was terminated on the basis of indication between the 28th and 36th week. Therapy had to be discontinued in 4 cases in each group, because of continued labor and birth, and in one case because of an amniotic infection syndrome. A full analysis of the treatment records of 57 pregnancies in the Ambroxol group was carried out; the corresponding figure for the betamethasone group was 58. In 39 patients the duration of pregnancy was 37 weeks or more, so that no assessment on the basis of neonatal pulmonary maturity was possible. In the remaining pregnancies, RDS morbidity was estimated on the basis of clinical and radiological findings and blood gas analysis. Related to a maximum duration of pregnancy of 34 weeks, RDS morbidity after Ambroxol therapy was 18.2% (2 out of 11), as opposed to 35.7% (5 out of 14) after betamethasone treatment. The results confirm that antenatal administration of Ambroxol can bring about a reduction in neonatal RDS corresponding to that achieved with betamethasone therapy. However, with Ambroxol the occurrence of side-effects is potentially lower; it therefore has advantages over betamethasone while being equally efficacious.

Ambroxol↗
PubMed1988

Ten highly sensitive thyrotropin assays compared by receiver-operating characteristic curves analysis: results of a prospective multicenter study.

We report a prospective multicenter study, undertaken to compare the efficacy of 10 highly sensitive thyrotropin assay kits for the diagnosis of hyperthyroidism. Performances of the kits were compared with a reference diagnosis based on clinical examination, pertinent biological tests, and determination by an independent laboratory of the concentrations in serum of free triiodothyronine and free thyroxin. No thyrotropin determination was used in establishing this reference diagnosis. Receiver-operating characteristic curves were obtained for results from 600 patients (217 hyperthyroid and 383 euthyroid) by each kit. Even though analyses were performed out of the working range of most kits, the clinical correlation was nevertheless excellent. The best results corresponded to a sensitivity of 97.5% associated with a specificity of 96.1% and were significantly better than those obtained with all other kits. Results of this comparison depended greatly on the heterogeneity of the "normal"/"abnormal" categories. When only diffuse hyperthyroidism was considered, sensitivity and specificity were improved for all kits, and there was no significant difference among the five best kits.

Humans↗
PubMed1983

[In vitro activity of cefatiolene (RP 42,980) against hospital bacteria. Comparison with cefotaxime and lamoxactam. Results of a multicenter study].

This work reports a multicenter study of antibacterial activity of cefatiolene (RP 42 980), a new third generation cephalosporin, in comparison with cefotaxime and lamoxactam. On the basis of MIC, activity of the three products is similar or Gram negative rods, but cefotaxime is a little more active on Enterobacteriaceae. The activity against Staphylococci requires further studies, indeed the determination of IC 50 of some strains showed a better activity of cefatiolene, but this was not observed by determination of MIC. As cefotaxime and contrary to lamoxactam, cefatiolene is active at low concentrations on other Streptococci than Enterococci, but a little on Bacteroides.

Bacteria↗