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PubMedDate not supplied

Simultaneous pancreas-kidney transplantation in a large multicenter study: surgical complications.

UNLABELLED: Simultaneous pancreas-kidney (SPK) transplantation has evolved as an effective treatment modality for patients with end-stage nephropathy owing to type 1 diabetes mellitus. This kidney-pancreas transplant procedure includes a number of risks, one of them being surgical complications, which were analyzed in this large prospective multicenter study. PATIENTS AND METHODS: The analysis included 205 patients randomly assigned to tacrolimus (n = 103) or cyclosporine ME (n = 102) in the Euro-SPK001 study. Surgical complications were defined as any intervention in the postoperative course related to the transplant procedure. RESULTS: The number of patients undergoing relaparotomy was significantly lower among the tacrolimus group (26.2%) as compared to the cyclosporine ME group (43.1%, P = .0109). Relaparotomy was performed earlier in the cyclosporine ME group (day 14 +/- 17) compared to patients in the tacrolimus group (day 26 +/- 26, P = .0506). Graft vessel thrombosis, intra-abdominal hemorrhage, and enteric or ureteral leakage within the first 3 months occurred significantly more frequently in cyclosporine ME-treated patients. Donor age above 45 years showed a negative impact on surgical complications. Relaparotomy had no impact on patient survival but significantly affected pancreas and kidney graft survival in both groups. CONCLUSION: This prospective, randomized, multicenter trial in patients undergoing primary SPK demonstrated a benefit of tacrolimus over cyclosporine ME with regard to the incidence of surgical complications and, consecutively, to kidney and pancreas graft survival.

Diabetes Mellitus, Type 1↗
PubMed2004

Long-term pooled analysis of multicenter studies of cooled thermotherapy for benign prostatic hyperplasia results at three months through four years.

OBJECTIVES: To determine the long-term efficacy of cooled thermotherapy in the treatment of lower urinary tract symptoms of clinical benign prostatic hyperplasia. METHODS: A total of 541 men underwent cooled thermotherapy treatment in six multicenter studies in the United States, England, and Canada. Both fixed and random effects models were used to pool the data across the six studies. The treatment response was measured as the difference between the urinary tract symptoms at baseline versus those at 3, 12, 24, 36, and 48 months after therapy. The treatment response included changes in the American Urological Association Symptom Score (AUA symptom score), peak urinary flow rate in milliliters per second (Qmax), and quality of life (QOL). RESULTS: The baseline measures were comparable across the studies. At 3 months, the AUA symptom score had improved by a mean of 11.6 (55%), Qmax by a mean of 4.0 (51%), and QOL by a mean of 2.3 (53%). These changes persisted with only slight attenuation through 48 months (corresponding mean changes of 43%, 35%, and 50%). These changes were highly statistically significant (P <0.0001 to 0.01). An improvement of at least 25% was achieved for the AUA symptom score and QOL by more than 85% of men and by more than 65% of men for Qmax. CONCLUSIONS: This pooled analysis of six multicenter studies of cooled thermotherapy, involving 541 men, found highly significant improvements in AUA symptom score, Qmax, and QOL. The results were highly consistent across the studies. The improvements reflected changes from baseline values of 45% to 50% for AUA symptom score and QOL and 35% to 40% for Qmax at a follow-up duration up to 48 months after therapy. The level of improvement for all three measures remained high at 48 months, indicating that the response is durable.

Aged↗
PubMed1998

Diet design for a multicenter controlled feeding trial: the DELTA program. Delta Research Group.

OBJECTIVE: To describe the process and results of diet standardization, diet validation, and monitoring of diet composition, which were key components of protocol 1 of Dietary Effects on Lipoproteins and Thrombogenic Activity (DELTA-1), the initial protocol in a program of multicenter human feeding studies designed to evaluate the effects of amount and type of fat on lipoproteins and hemostasis parameters in various demographic groups. DESIGN: DELTA-1 was based on a randomized, blinded, crossover experimental design. Three diets were fed for 8 weeks to 103 healthy men and women aged 22 to 67 years at 4 field centers. Diet A, an average American diet, was designed to provide 37% of energy from fat, 16% of energy from saturated fatty acids (SFAs); diet B (step 1 diet) was designed to provide 30% of energy from fat, 9% of energy from SFA; and diet C (low SFA diet) was designed to provide 26% of energy from fat, 5% of energy from SFA. Key features of diet standardization included central procurement of fat-containing foods, inclusion of standard ingredients, precision weighing of foods--especially sources of fat and cholesterol--and use of standardized written procedures. SETTING: For menu validation, a set of 12 menus for each diet was prepared in duplicate and chemically assayed. For monitoring of diet composition during the study, an 8-day diet cycle (6 weekday and 2 weekend menus) was sampled by every field center twice during each of 3 feeding periods. STATISTICAL ANALYSES: Means (+/- standard error) were calculated and compared with target nutrient specifications. RESULTS: DELTA-1 was able to provide a standardized diet that met nutrient specifications across 4 field centers over 24 weeks of participant feeding spanning a total of 8 months. APPLICATIONS: Prestudy chemical validation of menus and continuous sampling and assay of diets throughout the study are essential to standardize experimental diets and to ensure that nutrient target goals are met and maintained throughout a controlled multicenter feeding study.

Adult↗
PubMed1999

Long-term nitrate use may be deleterious in ischemic heart disease: A study using the databases from two large-scale postinfarction studies. Multicenter Myocardial Ischemia Research Group.

BACKGROUND: Secondary coronary prevention studies have generally focused on specific medications, often to the exclusion of commonly used therapies. To date, long-term nitrate use has not been investigated in large-scale clinical trials. METHODS AND RESULTS: We examined the relation between long-acting nitrates given during the chronic phase of the disease and the outcome. We analyzed data prospectively acquired in a large, observational study involving 1042 patients enrolled for the Multicenter Study of Myocardial Ischemia (MSMI) in North America, Israel, and Japan as well as 1779 patients enrolled for the Multicenter Diltiazem Post Infarction Trial (MDPIT). The Cox analyses with all the variables retained revealed that nitrates were associated with a significantly increased mortality risk (MSMI: hazard ratio 3.78, P =.011; MDPIT: hazard ratio 1.61, P =.019) in patients who had recovered from an acute coronary event. The analyses with the propensity score method on the MSMI and the MSMI databases also showed that the risk for cardiac death with use of nitrates was increased in most of the 5 subclasses according to the score. CONCLUSION: These analyses raise concern about the potential adverse effects of long-acting nitrate therapy in chronic coronary disease.

Databases, Factual↗
PubMed2001

Multicenter experience with the remote access perfusion (RAP) catheter.

BACKGROUND: Cardiac operation has rapidly evolved toward less invasive procedures. Total body perfusion from femoral or iliac vessels combined with endovascular aortic clamping can be achieved using the remote access perfusion (RAP) catheter without opening the sternum. The results of all reported RAP procedures were reviewed. METHODS: A US Food and Drug Administration/CE (Communaté Europeene) multicenter and postmark surveillance information survey from January 1999 to June 2000 evaluated 63 patients undergoing RAP procedures. The series includes coronary artery bypass grafting (46%), mitral valve operation (34%), and combined (3%) and miscellaneous procedures (17%). RESULTS: Since optimization of the catheter shape, easy placement was obtained during most procedures (74%). Only one procedure had to be converted to a standard approach. However, no dissection or perforation was reported. Perfusion yielded excellent flow characteristics of the RAP catheter predicted by in vitro studies. Continuous transesophageal echocardiography confirmed the stability of the endovascular balloon clamp (93%), most likely related to the near cylindrical balloon shape. In four cases an additional external cross-clamp was applied. The one reported hospital death (1.5%) was non-procedural related. No strokes were recorded. Peripheral vascular morbidity (8%) was higher during the early period but nearly disappeared after adaptation of the catheter shape. CONCLUSIONS: This multicenter study demonstrated the safety of the RAP technique. Excellent flow characteristics and balloon stability were obtained by improved technology. Indications will be extended in the future because of the device's enhanced safety and feasibility.

Aorta↗
PubMed2001

Initial prospective multicenter clinical trial of robotically-assisted coronary artery bypass grafting.

BACKGROUND: This multicenter prospective trial was designed to assess the safety and efficacy of using a robotically-assisted microsurgical system to create endoscopic coronary anastomoses. METHODS: . Thirty-two patients scheduled for elective primary coronary surgery underwent endoscopic anastomosis of the left internal thoracic artery (LITA) to the left anterior descending (LAD) artery. Three thoracic ports (two for instruments and one for a camera) were placed, and a robotic system was used to perform the LITA-LAD graft. Conventional techniques were used to perform the other grafts. Thirty-one patients underwent median sternotomy and 1 patient underwent a limited anterior thoracotomy. RESULTS: . Graft flow was measured in the operating room and averaged 37 +/- 19 mL/min. Mean anastomosis time was 24 +/- 9 minutes. There were three intraoperative revisions (9%). Two were for inadequate flow and one for an inadvertent injury. Each of these grafts was successfully revised by hand. There were no technical failures of the robotic system. Average postoperative length of stay was 5.5 +/- 2.7 days. There were three reoperations for bleeding, but none of these were related to the LAD anastomosis. Two months following the operation, selective angiography revealed a graft patency of 93%. The patients have been followed for 16 +/- 4 months. CONCLUSIONS: This initial prospective multicenter trial documents the feasibility of robotically-assisted coronary bypass grafting. Further trials are warranted to establish the safety and efficacy of this new technology.

Aged↗
PubMed2004

Off-pump versus on-pump myocardial revascularization in low-risk patients with one or two vessel disease: perioperative results in a multicenter randomized controlled trial.

BACKGROUND: To evaluate hospital mortality and morbidity after myocardial revascularization in a prospective and multicenter study, comparing on-pump versus off-pump in a special subset of patients with lesions in the left descending artery, alone or associated with the right coronary artery. METHODS: A multicenter prospective randomized study was performed. One hundred and sixty selected low-risk patients were enrolled; 80 patients were operated on-pump (coronary artery bypass grafting [CABG], group I) and 80 patients were operated off-pump (off-pump coronary artery bypass [OPCAB], group II). One hundred and five were male and ages ranged from 39 to 70 years old; mean 58.81 +/- 9.31 and median 59. Preoperative clinical characteristics were similar in both groups; only previous myocardial infarction was higher in the OPCAB group. Patients with severe left ventricular dysfunction (FE </= 35%), renal failure and lesions of the circumflex artery and its branches were excluded, as well as patients with significant comorbidities that were inappropriate for randomization because we selected them for OPCAB procedures. RESULTS: Hospital mortality was 2.5%, three patients (3.7%) in group I (on-pump) and one patient (1.2%) in group II (off-pump) (ns). The number of grafts per patients in group I was 1.81 +/- 0.6, and 1.77 +/- 0.68 in group II (p = 0.833). There was no difference in the total operation time 205.10 +/- 54.30 minutes in group I and 189.50 +/- 55.44 in group II (ns). Six patients (7.5%) had myocardial infarction in group I and three (3.7%) in group II (ns). Bleeding in the postoperative period was 680.50 +/- 434.1 mL in the on-pump group and 678.6 +/- 357.0 mL in the off-pump group (ns). Three patients (3.7%) presented transient neurologic dysfunction in group I and six patients (7.5%) in group II (ns). Intensive care stay was 2.4 +/- 1.0 days in the CABG and 2.3 +/- 0.98 days in the OPCAB group (ns). CONCLUSIONS: We did not find any statistical difference in hospital mortality and morbidity using on-pump or off-pump techniques for low-risk patients.

Adult↗
PubMed2003

The relationship between therapy intensity and rehabilitative outcomes after traumatic brain injury: a multicenter analysis.

OBJECTIVES: To identify factors relating to the intensity of rehabilitation services received and to ascertain the relation between injury outcomes, demographics, types of therapy, and the intensity of rehabilitation services provided. DESIGN: A multicenter, prospective, nonrandomized study with inpatient rehabilitation data collected between 1989 and 1996. SETTING: Three medical centers in the federally sponsored Traumatic Brain Injury Model Systems. In each setting, the continuum of care includes emergency medical services, intensive and acute medical care, and inpatient rehabilitation. PARTICIPANTS: A total of 491 consecutively enrolled patients with a mean age +/- standard deviation of 34.3+/-15.88 years recruited from 3 medical centers. To be included in the study, patients must have been at least 16 years of age, have presented to the emergency department within 24 hours of injury, and have received acute care and inpatient rehabilitation. INTERVENTIONS: Patients received comprehensive medical care along with a combination of rehabilitative therapies, including physical, occupational, psychologic, and speech therapy. MAIN OUTCOME MEASURES: Therapy intensity; levels of functional independence, cognitive function, functional gain, and treatment efficiency, as indicated by the FIM instrument; rehabilitation length of stay (LOS); and charges. RESULTS: Age predicted the intensity of both psychologic (P<.001) and total therapy (P<.01) services. Acute care LOS was also a significant predictor of psychologic services (P<.01). Only admission motor FIM was relevant in predicting speech services intensity (P<.01). Therapy intensity was predictive of motor functioning at discharge (P<.001). However, therapy intensity did not predict cognitive gain (P<.05). CONCLUSIONS: This study is among the first multicenter efforts to examine the potential benefits of individual therapy services. Findings support assertions that increased therapy intensity, particularly physical and psychologic therapies, enhances functional outcomes.

Adult↗
PubMed1997

Use of the 25 mm flanged esophageal Z stent for malignant dysphagia: a prospective multicenter trial.

BACKGROUND: An initial multicenter study using a 21 mm flanged esophageal Z stent demonstrated excellent palliation but an 11% immediate complication rate at placement and a 27% migration rate at 1 month. This North American multicenter trial prospectively studied a 25 mm flanged Z stent to define its palliative ability and whether the increased diameter affected placement or migration problems. METHODS: Fifty patients who had esophageal Z stents at seven university or regional referral hospitals were prospectively studied. Indications for prosthesis placement, previous therapy, patient demographics, incidence of concomitant tracheoesophageal fistula, and degree of dysphagia were defined, as were procedural and subsequent stent-related problems, survival times, the ability to occlude a tracheoesophageal fistula, and subsequent degree of dysphagia. RESULTS: Twenty-four patients had infiltrating malignancy (16 exophytic and 10 extrinsic), 9 of whom had concomitant tracheoesophageal fistulas. Ten patients (20%) had misplaced stents requiring retrieval and replacement, 12 patients (24%) had subsequent stent-related problems including exsanguination (2), aspiration (3), tumor overgrowth (3), and postplacement migration (4) (8%). There was statistically significant improvement in prestent versus poststent dysphagia and two thirds of patients had complete occlusion of their tracheoesophageal fistula. CONCLUSIONS: Redesign of the esophageal Z stent has decreased the migration rate without increasing placement or subsequent erosion problems. Its efficacy appears comparable to the currently marketed Z stent for the palliation of malignant dysphagia and occlusion of tracheoesophageal fistula.

Aged↗
PubMed1997

Oscillometric twenty-four-hour ambulatory blood pressure values in healthy children and adolescents: a multicenter trial including 1141 subjects.

Ambulatory blood pressure (ABP) monitoring is increasingly used to evaluate the blood pressure of children and adolescents. The upper normal ABP values in the pediatric age group are still unknown, because reference values based on a sufficiently high number of healthy children have not yet been published. In this multicenter trial, we pooled ABP records of 1141 healthy children and adolescents with a body height between 115 and 185 cm. The study was carried out by seven centers according to a common protocol. The 50th percentile for 24-hour systolic ABP increased moderately with height, from 103 to 113 mm Hg in girls and from 105 to 120 mm Hg in boys. The 50th percentile for diastolic 24-hour means was 66 +/- 1 mm Hg, irrespective of height or gender. Diastolic daytime means were 73 +/- 1 mm Hg, which is remarkably high compared with reference values for casual blood pressure. The mean nocturnal systolic and diastolic ABP (midnight to 6 AM) was 13% +/- 6% and 23% +/- 9% lower compared with the daytime means (8 AM to 8 PM), respectively. This multicenter study provides well-based limits of normal ABP in mid-European children.

Adolescent↗
PubMed2006

Single-blind, multicenter, placebo controlled, parallel study to assess the safety and efficacy of intralesional interferon alpha-2B for minimally invasive treatment for Peyronie's disease.

PURPOSE: We investigated the efficacy and safety of intralesional interferon alpha-2b for the treatment of Peyronie's disease. MATERIALS AND METHODS: A total of 117 consecutive patients with a mean age of 55.1 years who had Peyronie's disease were enrolled in a single-blind, multicenter, placebo controlled, parallel study to determine the efficacy and safety of intralesional interferon alpha-2b therapy (Schering, Kenilworth, New Jersey), including 62 who received placebo and 55 who received interferon alpha-2b. Saline (10 ml) in controls and interferon alpha-2b (5 x 10(6) U) were administered biweekly for 12 weeks. Each patient was evaluated for penile curvature, plaque size and density, penile pain, erectile function and penile hemodynamics before and after study completion. Improvement in these parameters was statistically compared between the groups. RESULTS: A total of 53 patients in the control arm and 50 in the interferon alpha-2b arm completed the study. Improvement in penile curvature, plaque size and density, and pain resolution was significantly greater in patients treated with interferon alpha-2b vs placebo. The increase in mean International Index of Erectile Function scores was not significantly different between the groups. Penile blood flow improvement was observed in interferon alpha-2b treated patients but not in those who received placebo. The decrease in the number of penile vascular pathologies was significantly higher in interferon alpha-2b cases. Side effects, mostly flu-like symptoms, which were frequently noted in patients on interferon alpha-2b, were mild to moderate in degree and of short duration. CONCLUSIONS: This single-blind, multicenter, placebo controlled, parallel study demonstrates that intralesional interferon alpha-2b at a dose of 5 x 10(6) units biweekly for 12 weeks is effective and safe as minimally invasive therapy for Peyronie's disease.

Adult↗
PubMed2000

Use of the World Wide Web in research: randomization in a multicenter clinical trial of treatment for twin-twin transfusion syndrome.

OBJECTIVE: To describe the process involved in using the World Wide Web to coordinate a randomized, multicenter international trial of treatment for twin-twin transfusion syndrome. METHOD: A Web site was designed by members of the research team, a Web consultant, and a senior computer programmer. The original intent was to provide patient randomization only, but the Web site later was designed so that centers could download a data collection form. Data could be entered directly into the Web site and subsequently imported into a database at the coordinating center. EXPERIENCE: The Web site has been active for 3 years, with 13 participating centers and 31 patients enrolled. COMMENT: Use of the World Wide Web to coordinate an international, multicenter trial is an efficient method. Although there are many benefits, the most obvious is the capability to initiate and conduct a large international trial at minimal cost.

Communication↗
PubMed2001

Variability in the assessment of adverse events in a multicenter clinical trial.

BACKGROUND: Consistent documentation, characterization, and evaluation of adverse events (AEs) are needed during multicenter clinical trials to ensure accuracy of data reported to the US Food and Drug Administration and in the medical literature. OBJECTIVE: The purpose of this study was to identify and characterize variations in the assessment of AEs by clinical trial personnel. METHODS: During the annual meeting of personnel from a multicenter, controlled clinical trial of an investigational new drug treatment for opioid dependence, an oral presentation of procedures for AE data collection was given to 25 principal investigators and ancillary study personnel who assessed AEs for the study. A post-test using 3 hypothetical AE cases in which AEs were categorized by type of reaction, relatedness to study drug, severity, action taken, and outcome was completed by study participants. Cases and expected responses were reviewed for content and validity by clinical research pharmacists who were not involved with the study. The level of agreement with expected responses was assessed using McNemar symmetry chi-square tests. RESULTS: Assessments of type of AE, relatedness to study drug, and severity were less frequently aligned with expected responses than were action taken and outcome (P < 0.013). Less consistency with expected responses was found in I case than in the other 2, suggesting that certain types of AEs may be more difficult to assess. CONCLUSIONS: There was considerable variability in categorization of AEs in an exercise following training for AE data collection. Type of report, relatedness, and severity were found to have more variability in reporting than did action taken or outcome. The results suggest that unless data are gathered to verify reliability of reporting, subcategorization of AE data should be undertaken cautiously. Further research is needed regarding methods for improving consistency in reporting of AEs.

Clinical Trials as Topic↗
PubMed2003

Migraine treatment patterns and patient satisfaction with prior therapy: a substudy of a multicenter trial of rizatriptan effectiveness.

BACKGROUND: Migraine is a common, chronic, often disabling neurologic condition that is underdiagnosed and undertreated. OBJECTIVE: We undertook this questionnaire-based study as a substudy of a multicenter trial of rizatriptan effectiveness. Our goal was to assess the history of acute migraine medication use and the relationship between different migraine medication regimens and patient satisfaction with prior therapy. METHODS: This study was conducted at 85 neurology clinics throughout Spain from March Lo December 2001. It was planned prospectively as part of the screening visit for a multicenter trial of the effectiveness of rizatriptan therapy for migraine. Male and female patients >/=18 years of age were eligible for the primary trial, and hence for this study, if they had a history of migraine attacks and did not have a contraindication for triptan use. At the screening visit for the primary trial, a questionnaire was used by clinicians to record past and current use, and duration and order of use, of analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), ergot derivatives, and triptans; satisfaction with treatment was scored on a 5-point scale ranging from "very dissatisfied" to "very satisfied." RESULTS: Of 712 patients completing the questionnaire (mean [SD] age, 34 [10] years; range, 18-69 years), 75% were women and 94% experienced moderate or severe functional disability during migraine attacks. Analgesics were used by the majority of patients (81%) and for the longest mean [SD] duration (8.8 [7.6] years) but were associated with the least satisfaction (10% of patients "very satisfied" or "somewhat satisfied"). Triptans were used by the fewest patients (32%) and for the shortest mean duration (18 [1.6] years) but were associated with the highest rate of satisfaction (66%) compared with NSAIDs (27%) and ergot derivatives (31%). Regardless of duration or order of drug use, or sex or age of the patient, the likelihood of satisfaction with triptans was significantly greater (P < 0.001) than with nontriptan regimens, with an adjusted odds ratio (95% CI) of 16.8 (11.4-24.9) versus analgesics, 5.1 (3.6-7.1) versus NSAIDs, and 4.1 (2.8-6.0) versus ergot derivatives. CONCLUSIONS: Our results showed that analgesics, NSAIDs, and ergot derivatives were used for long durations but provided low satisfaction among patients. Triptans were rarely used as a first treatment choice; however, patients reported the highest treatment satisfaction scores after triptan therapy compared with ergot derivatives, NSAIDs, or analgesics.

Adolescent↗
PubMed1997

The management of giant retinal tears using perfluoroperhydrophenanthrene. A multicenter case series. Vitreon Collaborative Study Group.

OBJECTIVE: The purpose of the study was to determine the predictors of success and evaluate the use of perfluoroperhydrophenanthrene as an intraoperative and postoperative tool in the management of giant retinal tears in a multicentered collaborative study. DESIGN: Multicentered prospective case series. PARTICIPANTS: Twenty-three centers consecutively enrolled 162 eyes of 161 patients with retinal tears 90 degrees or greater in circumferential extent. INTERVENTION: Perfluoroperhydrophenanthrene was used as an intraoperative surgical adjunct in all cases and left after surgery in 16 eyes (9.9%). MAIN OUTCOME MEASURES: Retinal reattachment and visual acuity. RESULTS: Intraoperative reattachment was achieved in 158 eyes (97.5%); 147 eyes (90.7%) remained attached at their most recent follow-up. Seventy-nine eyes (48.8%) experienced an improvement in their visual acuity, 26 eyes (16.0%) remained unchanged, and 57 (35.2%) worsened. Recurrent retinal detachment occurred in 80 patients (49.4%). Other significant postoperative complications included cataract formation in 20 (39.2%) of 51 eyes, macular pucker in 12 (7.4%), corneal decompensation in 10 (6.2%), and hypotony (intraocular pressure equal to or less than 5 mmHg) in 9 (5.6%). A chi-square analysis of preoperative characteristics showed that hypotony (P = 0.007), macular detachment (P = 0.020), a history of cataract extraction (P = 0.003), poor visual acuity (P = 0.000), giant tear extent greater than 180 degrees (P = 0.004), and higher grade proliferative vitreoretinopathy (P = 0.000) all predicted a poor visual outcome. Vitreon (Vitrophage, Inc., Lyons, IL) was left in 16 eyes (9.9%) for an extended postoperative retinal tamponade for between 3 and 1034 days (mean, 87.2 days). The Vitreon was well tolerated, and these eyes experienced a similar outcome and rate of retinal reattachment to the rest of the group. CONCLUSIONS: Vitreon is a safe and useful adjunct to pars plana vitrectomy in the management of giant retinal tears and may, additionally, be the perfluorocarbon liquid that can be used most safely as a temporary postoperative tool for extended retinal tamponade, reinforcing its role as a useful adjunct in the management of these complex retinal detachments.

Adolescent↗
PubMed1996

Genomic fingerprinting of 80 strains from the WHO multicenter international typing study of listeria monocytogenes via pulsed-field gel electrophoresis (PFGE).

An international multicenter typing study of Listeria monocytogenes was initiated by the World Health Organization (Food Safety Unit, Geneva) in order to evaluate the usefulness of various phenotypic and genotypic typing methods for L. monocytogenes, to select and standardize the most appropriate methods to define common nomenclature of varieties and to select specific reference strains. Pulsed-field gel electrophoresis was used in four laboratories for molecular characterization of a set of 80 'coded' strains distributed to all participating laboratories. The endonucleases ApaI and SmaI, used in all four laboratories, yielded between 21 and 28 restriction endonuclease digestion profiles (REDP). AscI was used, in addition, in laboratory A and displayed 21 REDP. The combination of ApaI, SmaI or AscI REDP established 25 to 33 genomic groups. depending on the laboratory and the number of viable strains. Agreement of typing data among the four laboratories ranged from 79 to 90%. Forty-nine (69%) of the 71 strains viable in all four laboratories were placed into exactly the same genomic groups in all four laboratories. The epidemiological relevance of the strains became known after decoding and it was shown that most of the epidemiologically related strains were correctly identified by the four groups of investigators. i.e., most related strains were placed into the same genomic groups by all four laboratories. Similar results were obtained when 11 duplicate cultures were analyzed-on average 84% of the duplicates were identified. Comparison of REDP obtained by laboratory A with REDP from previously analyzed set of 176 L. monocytogenes strains allowed the prediction of the serovar-groups of the 80 strains. These predictions of serovar-groups were later confirmed by serotyping results obtained by laboratories involved in the WHO multicenter typing study of L. monocytogenes. In general this study reconfirmed that PFGE is a very accurate and reproducible method for fine structure comparison and molecular typing of L. monocytogenes.

Bacterial Typing Techniques↗
PubMed1997

Clinical efficacy and safety comparison of adapalene gel and tretinoin gel in the treatment of acne vulgaris: Europe and U.S. multicenter trials.

BACKGROUND: Adapalene is a new chemical entity that exhibits tretinoin-like activities in the terminal differentiation process. OBJECTIVE: We evaluated a dose range effect of two concentrations of adapalene gel as acne treatment and compared adapalene 0.1% gel with tretinoin 0.025% gel in the treatment of acne patients in two large multicenter studies. METHODS: Multicenter, investigator-masked, parallel group studies including 89 acne patients in the dose range study and 591 patients in the concurrent controlled studies were conducted. RESULTS: Adapalene gel 0.1% was significantly more effective in treating acne lesions than 0.03% adapalene gel. Adapalene gel 0.1% was significantly more effective than 0.025% or tretinoin gel in one study and of the same effectiveness in the other study. Adapalene gel was always better tolerated than tretinoin gel. CONCLUSION: Adapalene 0.1% gel is a safe and effective treatment of acne vulgaris.

Adapalene↗
PubMed1999

Modifiable factors associated with improved cardiac arrest survival in a multicenter basic life support/defibrillation system: OPALS Study Phase I results. Ontario Prehospital Advanced Life Support.

STUDY OBJECTIVES: This study was conducted to identify modifiable factors associated with survival for prehospital cardiac arrest in a large, multicenter EMS system with basic life support/defibrillation (BLS-D) level of care. METHODS: This observational cohort study constitutes Phase I of the 3-phase Ontario Prehospital Advanced Life Support (OPALS) Study. Included were all adults who had cardiac arrest before EMS arrival in 21 urban/suburban communities that operate under the jurisdiction of 1 ambulance services branch, have 911 telephone service, and provide ambulance defibrillation but no prehospital advanced life support (ALS). Central dispatch and ambulance records were reviewed according to the Utstein guidelines. Associations between multiple patient and EMS factors and survival to discharge were assessed by univariate then stepwise logistic regression analyses. RESULTS: From January 1, 1991, to January 31, 1995, 5,335 eligible patients were treated. Of these, 46.8% of cardiac arrests were witnessed by citizens, 14.5% received bystander CPR, 25.6% received CPR by fire or police, and 38.2% had an initial rhythm of ventricular fibrillation/ventricular tachycardia (VF/VT). The mean interval from call received to vehicle stopped was 6.7 minutes. Survival was 3.5% overall and 8.8% for VF/VT. Multivariate analysis found the following factors to be independently associated with survival (odds ratio with 95% confidence intervals): age.81 (. 73,.89), bystander-witnessed arrest 4.05 (2.78, 5.90), bystander CPR 2.98 (2.07, 4.29), CPR by fire or police 2.20 (1.46, 3.31), and response interval call received to vehicle stopped.76 (.71,.82). CONCLUSION: This represents the largest multicenter BLS-D study of prehospital cardiac arrest yet conducted and clearly indicates that patient survival may be improved by optimization of EMS response intervals, bystander CPR, as well as first-responder CPR by fire or police.

Adolescent↗