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Tertiary Centers (tertiary + center)
Selected AbstractsThe Impact of Surgery in the Management of the Head and Neck Carcinoma Involving the Carotid Artery,THE LARYNGOSCOPE, Issue 10 2008Enver Ozer MD Abstract Objectives/Hypothesis: To demonstrate the feasibility of the carotid artery dissection and/or resection and reanastomosis, and to show its positive impact on survival and disease control rates for the head and neck carcinomas involving the carotid artery. Study Design: Tertiary center (Comprehensive Cancer Center). Case series review. Methods: The data of 90 patients with head and neck malignancies involving the carotid artery were operated for the carotid artery dissection and/or resection, and reanastomosis in the last 10 years were retrospectively reviewed and analyzed. Results: Eighty (89%) of the 90 patients' head and neck malignancies were squamous cell carcinoma. Fifty-two (65%) and 28 (35%) of 80 patients were recurrent and stage IV disease, respectively. There was no stage I to III disease. Carotid artery was dissected and preserved in 64 (71.1%) of the 90 patients. Eighteen (20%) of 90 patients needed carotid artery dissection with resection and reanastomosis. Eight (8.9%) patients were unresectable. Sixty (75%) of 80 patients needed reconstruction with regional or free flaps and grafts. Overall 2- and 5-year estimated survivals were 32.4% and 27.8% for all; 14.3% and 10.7% for recurrent; 64.3% and 57.8% for stage IV previously untreated; and 22.0% and 22.0% for carotid artery resected-reanastomosed patients, respectively. Conclusions: The carotid artery dissection without resection is an achievable goal in majority of patients with the advanced stage head and neck carcinoma involving the carotid artery. Resection and reanastomosis of carotid artery, especially in the previously untreated carotid involved patients, is a feasible surgery and achieves better survival and disease control rates when compared with the unresected or recurrent disease patients. [source] Small and Medium-Sized Congenital Nevi in Children: A Comparison of the Costs of Excision and Long-Term Follow-UpDERMATOLOGIC SURGERY, Issue 12 2009FERNANDO ALFAGEME ROLDÁN MD BACKGROUND Clinical decisions on whether to follow up or remove small and medium congenital melanocytic nevi (SMCMN) in children have cost implications that have not been studied. OBJECTIVES To compare the costs of excision of SMCMN in children with lifelong follow-up in a tertiary center. METHODS AND MATERIALS We elaborated models for the evaluation of the costs of excision and long-term follow-up. We retrospectively collected data on 113 consecutive excised SMCMN (105 single-step interventions and 8 multiple-step interventions) from the medical records of our pediatric dermatology unit from 2001 to 2007 and calculated and compared the costs (direct and indirect) of surgery and follow-up. RESULTS The mean ± standard deviation and total cohort costs for single-step interventions were ,1,504.73 ± 198.33 and 157,996.20, respectively. Median and cohort lifelong follow-up costs were similar if performed every 4 years (1,482.66 ± 34.98 and 156,679.63). For multiple-step interventions (3 or 4 steps), surgery costs were similar to those of annual lifelong follow-up. In the case of two-step surgery, costs were similar to lifelong follow-up every 2 years. CONCLUSIONS An analysis of the costs of surgery and long-term follow-up in children with SMCMN is possible. Although the clinical judgment of the dermatologist and parental opinion are the main determinants in the management of SMCMN, costs should also be taken into account. [source] Cervical biopsy-based comparison of a new liquid-based thin-layer preparation with conventional Pap smearsDIAGNOSTIC CYTOPATHOLOGY, Issue 4 2004Maria da Gloria Mattosinho de Castro Ferraz M.D. Abstract The objective of this study is to compare the diagnostic efficacy of universal collection medium (UCM) liquid-based cytology (LBC) (Digene Corp., MD) and the conventional Pap smear in a comparative study, using histologic results as the gold standard. This was a cross-sectional study. Conventional Pap smears and UCM LBC specimens, obtained from women in a low socioeconomic outpatient population referred to a tertiary center for gynecologic care, were compared. For the purpose of this study, when cervical specimens were collected for cytology, all women underwent colposcopy and biopsy was done if a cervical abnormality was observed. Cytologic evaluation of UCM LBC and conventional Pap smears were carried out separately, masked to the results of the other method. Agreement beyond chance between the two cytologic methods was ascertained by means of the unweighted , statistic. Sensitivity, specificity, and predictive values with 95% confidence intervals were calculated for both methods. McNemar's test was used to determine the level of association between the two cytology procedures. A total of 800 women were evaluated. Assessment of the overall agreement between the two cytologic methods yielded a , of 0.777 (P < 0.0001). After adjustment for histologic diagnosis, the computed , in each stratum was as follows: normal = 0.733; CIN 1 = 0.631; CIN 2/3 = 0.735; cancer = 0.652. The sensitivity and specificity of UCM LBC for detection of cervical intraepithelial lesions and cancer were 75.3% and 86.4%, respectively, not statistically different from the 81.8% and 85.2% seen with the conventional method. This study demonstrates that the UCM LBC method is as accurate as the conventional Pap smear cytology in detecting cervical intraepithelial lesions and cancer even so the UCM samples were systematically prepared from a second sampling of the cervix. Diagn. Cytopathol. 2004;30:220,226. © 2004 Wiley-Liss, Inc. [source] The Impact of Diabetes Mellitus on Two-Year Mortality Following Contemporary Percutaneous Coronary Intervention: Implications for Revascularization PracticeJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 5 2009M. ANDRON M.D., M.R.C.P. Objective:To assess the impact of diabetes on 2-year mortality in current PCI practice. Background:In patients with coronary artery disease undergoing revascularization, diabetes mellitus is associated with higher mortality. Methods:A retrospective analysis was done of all patients undergoing PCI at our tertiary center between January 2000 and December 2004. There were 6,160 PCI procedures performed in 5,759 patients who received at least one stent. Of these patients, 801 (13.9%) were diabetic and 4,958 (86.1%) were nondiabetic. The primary outcome measure of the study was all-cause mortality. All patients were followed up for a period of 2 years. Multivariate logistic regression analysis was used to test for a potential independent association between diabetic status and follow-up mortality. Results:Before adjustment, a trend toward higher mortality was observed in diabetic patients compared to non-diabetics at 1 year (3.2% vs 2.4%) and 2 years (5.1% vs 3.8%), P = 0.12. Independent predictors for mortality were increasing age, renal dysfunction, peripheral vascular disease, NYHA class >2, urgent PCI, treating left main stem lesions, vessel diameter , 2.5 mm, and 3-vessel disease. The use of drug-eluting stent was associated with a reduction in mortality. Diabetes was found to have no independent impact on mortality following PCI (odds ratio = 1.08; 95% confidence intervals = 0.73,1.60; P = 0.71). Conclusion:The presence of diabetes was not an independent predictor of mortality following PCI. A diabetic patient that does not require insulin treatment and has no evidence of macro- or microvascular diabetic disease could enjoy a PCI outcome similar to nondiabetic subjects. [source] Role of metastasectomy in the management of thyroid carcinoma: The NIH experienceJOURNAL OF SURGICAL ONCOLOGY, Issue 1 2003Ho Pak MD Abstract Background and Objectives We studied the impact of metatasectomy on disease outcome in 29 advanced nonmedullary thyroid carcinoma (ThyrCa) patients who were operated on between 1969 and 2001 at NIH to further define its role in the management of this malignancy. Methods Data were extracted by retrospective chart review. A Kaplan-Meyer survival curve was constructed, and comparative stratification for various parameters was performed. Results During 47 surgeries, the following lesions were resected from mid-mediastinum/hila, 17; lung parenchyma, 12; skeleton, 14; kidneys, 2; and brain, 2. All patients received multiple radioiodine (RAI) treatments. External-beam radiotherapy, chemotherapy and other palliative measures were used in selected patients. Six patients (21%) died within 74.7,±,54.7 months after the first distant metastasectomy. The outcome of the remaining patients was as follows: complete remission, 3; partial remission, 10; and 10: progressive disease, 10, with a follow-up of 175 patient-years. Metastasectomy led to a decrease of 38% in thyroglobulin levels in 23 patients. Cumulative survival rates were 78.5,±,8.4% at 5 years and 50.2,±,12.5% at 10 years (mean ±SEM) after initial distant metastasectomy. Conclusions Our data show that extensive targeted metastasectomy in the setting of a tertiary center can be beneficial to patients with disseminated ThyrCa with persistent or recurrent distant disease, when used in conjunction with nonsurgical treatment modalities. J. Surg. Oncol. 2003;82:10,18. © 2002 Wiley-Liss, Inc. [source] Pediatric venous thromboembolic disease in one single center: congenital prothrombotic disorders and the clinical outcomeJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 12 2003C. H. Van Ommen Summary., To learn more about the frequencies of congenital prothrombotic disorders in pediatric venous thromboembolism (VTE) and the outcome of this disease, we evaluated consecutive patients from 0 to 18 years with objectively diagnosed VTE at a single tertiary center over a 12-year period. We included 100 patients, with a median age at diagnosis of 1.0 year (range 2 days to 17 years). At least one underlying clinical condition was present in 96% of the patients. Factor (F)V G1691A mutation was present in 13%, FII G20210A mutation in 3%, antithrombin deficiency in 1%, protein C deficiency in 1% and protein S deficiency in 1% of the tested patients. Combined defects were present in 2.6% of the 77 patients with a complete work-up. Positive family history appeared to be the only predictor for positive testing for congenital disorders (OR 14.9, 95% CI 1.9,113). The overall mortality rate was 20%. The cumulative recurrence-free survival was 92% after 1 year of follow-up, and 82% after 7 years. The incidence and severity of the post-thrombotic syndrome was analyzed in a subgroup of 33 patients with VTE of the lower extremities. Twenty-three (70%) patients developed PTS: moderate in three and mild in 20 patients. In conclusion, congenital prothrombotic disorders seem to play a role in the development of pediatric VTE, and the risk of complications of this disease is high. [source] Cerebral mycosis: 7-year retrospective series in a tertiary centerNEUROPATHOLOGY, Issue 3 2010Kirtee Raparia This study focuses on the epidemiology, clinical manifestations, risk factors, diagnosis and outcome of all cases of central nervous system (CNS) fungal infections in a tertiary center. Medical records of 18 patients of culture-proven CNS fungal infections were retrospectively reviewed from 2000 to 2007, including 12 isolated from the cerebrospinal fluid (CSF) and seven from tissue biopsy. Patient demographic data included 10 males and eight females. The mean age was 55 years (range: 24,89 years). All but one patient were immunocompromised. Fungal organisms isolated from CSF included: Cryptococcous neoformans (8 patients), Coccidioides immitis (3 patients), and Aspergillus versicolor (1 patient). Histopathology of seven biopsy cases revealed groups of pigmented golden-brown fungal forms in three cases; three cases showed septate fungi, two of which had melanin in their walls; and one case showed multiple round spherules. These cases on microbiological cultures grew Coccidioides immitis (1 patient), Aspergillus fumigatus (1 patient), Cladophialophora bantiana (2 patients), Fonsecaea monophora (1 patient) and Scedosporium apiospermum (2 patients). Five of the seven fungal organisms isolated from tissue biopsies were dematiaceous fungi. Twelve patients died after a period of a few weeks to months, two were lost to follow-up, and four are alive with severe neurological sequelae. CNS fungal infections in our cohort were more common in patients post-transplant and with hematologic malignancies. In our series, rare dematiaceous fungi are emerging agents for cerebral mycosis. The outcome of CNS fungal infections is poor despite vigorous antifungal therapy. [source] A Clinical Risk Score to Predict the Time to First Appropriate Device Therapy in Recipients of Implantable Cardioverter DefibrillatorsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2007HAITHAM HREYBE M.D. Background:To develop a risk score to predict the occurrence of appropriate defibrillator [implantable cardioverter-defibrillator (ICD)] therapies. A simple clinical score predicting the risk of appropriate ICD therapy is lacking. Methods:A Cox regression model was developed from a database of ICD patients at a single tertiary center to predict the time to appropriate ICD therapy defined as shock or antitachycardia pacing. A risk score was derived from this model using half of the database and was validated using the other half. Results:A total of 399 patients were entered into the database between July 2001 and February 2004. There were no statistically significant differences between the derivation (n = 200) and validation (n = 199) groups in any of the demographic or clinical variables recorded. The risk score included three independent variables: indication for ICD implantation (P = 0.03), serum creatinine level (P = 0.015), and QRS width (P = 0.028). The observed risk scores were highly predictive of time to ICD therapy in the validation group (P = 0.02). Conclusion:We describe a new clinical risk score that predicts the time to appropriate device therapy in ICD recipients of a single tertiary center hospital. The performance of this risk score needs to be investigated prospectively in a larger patient population. [source] Racing against the clock: Recognizing, differentiating, diagnosing, and referring the amyotrophic lateral sclerosis patient,ANNALS OF NEUROLOGY, Issue S1 2009Steven J. Shook MD Recognition of the early symptoms and signs in amyotrophic lateral sclerosis, exclusion of alternative diagnoses, and referral to a tertiary center can have a significant positive impact on the lives of patients and their caregivers. This article provides the most current amyotrophic lateral sclerosis criteria, as well as helpful clinical clues to the diagnosis. An approach to laboratory testing, electrodiagnostic testing, and imaging to exclude diseases that mimic ALS also are discussed, as are atypical presentations that can confound timely diagnosis. Ann Neurol 2009;65 (suppl):S10,S16 [source] Clinical Implications of QRS Duration and QT Peak Prolongation in Patients with Suspected Coronary Disease Referred for Elective Cardiac CatheterizationANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2008M. Nadeem Attar M.D., M.R.C.P. Background: The electrocardiogram (ECG) remains a simple, universally available, and prognostically powerful investigation in heart failure, and acute coronary syndromes. We sought to assess the prognostic utility of clinical, angiographic, and simple ECG parameters in a large cohort of patients undergoing elective cardiac catheterization (CC) for known or suspected coronary artery disease. Methods: Consecutive consenting patients undergoing CC for coronary disease were enrolled at a single tertiary center. Patient data, drug therapy, catheter reports, and ECG recordings were prospectively recorded in a validated electronic archive. The primary outcome measure was death or nonfatal myocardial infarction (MI) over 1 year or until percutaneous or cardiac surgical intervention. Independent prognostic markers were identified using the Cox proportional hazard model. Results: A total of 682 individuals were recruited of whom 17(2.5%) died or suffered a nonfatal MI in 1 year. In multivariate analysis QRS duration (ms) (HR 1.03 95% CI 1.01,1.05, P = 0.003), extent of coronary disease (HR 2.01 95% CI 1.24,3.58, P = 0.006), and prolonged corrected QT peak interval in lead I (HR 1.02 95% CI 1.00,1.03, P = 0.044) were independently associated with death or nonfatal MI. Receiver-operator characteristic (ROC) analysis for the multivariate model against the primary end point yielded an area under the curve of 0.759 (95% CI 0.660,0.858), P < 0.001. Conclusions: QRS duration and QT peak are independently associated with increased risk of death or nonfatal MI in stable patients attending for coronary angiography. [source] Base of skull recurrences after treatment of salivary gland cancer with perineural invasion reduced by postoperative radiotherapyCLINICAL OTOLARYNGOLOGY, Issue 6 2009A.M. Chen Objectives:, To determine the effect of postoperative radiation therapy for salivary gland carcinomas in the presence of microscopic perineural invasion. Design and setting:, Retrospective review at an academic tertiary center. Participants:, One hundred and forty patients with pathological evidence of perineural invasion at the time of initial surgery for salivary gland carcinomas were analysed. Sixteen patients (11%) had major (named) nerve involvement. Ninety-four patients (67%) received postoperative radiation therapy to the primary site, and the portal films of 65 of these patients were available for review. Main outcome measures:, The incidence of skull base recurrences among patients treated by surgery with or without postoperative radiation therapy. Results:, Ten patients experienced skull base recurrences. T4 disease and the omission of postoperative radiation therapy were identified as significant predictors of skull base recurrence. Postoperative radiation therapy reduced the actuarial probability of skull base recurrence from 15% to 5% (P = 0.03). The crude rates of skull base recurrence were 6% (2/35) and 10% (3/30), respectively, for patients whose skull base were and were not confirmed to be encompassed in the irradiation field. The 5-year overall survival for patients who experienced a skull base recurrence was 19% compared to 91% for those who did not (P < 0.001). Conclusion:, The use of postoperative radiation therapy significantly reduced the incidence of skull base recurrence among salivary gland carcinoma patients with perineural invasion. Clin. Otolaryngol. 2009, 34, 539,545. [source] Prevalence and Characteristics of Left Ventricular Noncompaction in a Community Hospital Cohort of Patients with Systolic DysfunctionECHOCARDIOGRAPHY, Issue 1 2008Roopinder Sandhu M.D. Background: Left ventricular noncompaction (LVNC) is felt to be a rare form of cardiomyopathy, although its prevalence in a nonreferred population is unknown. We examined the prevalence and clinical characteristics of LVNC in a community hospital cohort of adult patients with echocardiographic evidence of left ventricular (LV) systolic dysfunction. Methods: All adult echocardiograms with global LV dysfunction and an LVEF , 45% over a 1-year period were reviewed for signs of LV noncompaction. Its presence was confirmed by the consensus of at least 2/3 readers specifically searching for this using standard criteria for noncompaction. Results: A 3.7% prevalence of definite or probable LVNC was found in those with LVEF, 45% and a 0.26% prevalence for all patients referred for echocardiography during this period. This is appreciably higher than prior reports from tertiary centers. Conclusion: Noncompaction may not be a rare phenomenon and is comparable to other more widely recognized but less common causes of heart failure such as peripartum myopathy, connective tissue diseases, chronic substance abuse and HIV disease. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Cover Picture: (Adv. Synth.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2009Catal. The cover picture, provided by Maurice S. Brookhart, shows an example of a cationic palladium diimine complex which catalyzes polymerization of ethylene to high molecular weight, highly branched polyethylene. The catalyst resting states are the alkyl ethylene complexes as modeled by the ethyl ethylene complex shown. Migratory insertion of these alkyl ethylene species leads to ,-agostic complexes in which palladium can rapidly migrate along the chain ("chain-walking") through ,-elimination/readdition reactions. Trapping of branched alkyl complexes followed by insertion leads to formation of branches in the polymer chain. Polyethylenes formed exhibit branches-on-branches since chain-walking through tertiary centers is facile. [source] Uveitis caused by fastidious bacteriaACTA OPHTHALMOLOGICA, Issue 2009B BODAGHI Purpose The etiologic evaluation of uveitis is frequently unsuccessful if only noninvasive methods are used. We conducted a prospective study to evaluate systematic screening for pathogens of uveitis. Methods All patients with uveitis referred to the participating tertiary ophthalmology departments from January 2001 to September 2007 underwent intraocular and serum specimen collection. The standardized protocol for laboratory investigations included universal polymerase chain reaction (PCR)-based detection of any bacteria and mycoses, specific PCR-based detection of fastidious (difficult-to-grow) bacteria and herpes viruses, and culture of vitreous fluid. Sera were tested for fastidious bacteria. Results Among the 1321 included patients, infection was diagnosed in 147 (11.1%) patients: 78 (53%) were caused by fastidious bacteria that included spirochetes, Bartonella species, intracellular bacteria (Chlamydia species, Rickettsia species, Coxiella burnetii), and Tropheryma whipplei; 18 by herpes viruses; and 9 by fungi. Bartonella quintana, Coxiella burnetii, Paracoccus yeei, Aspergillus oryzae, and Cryptococcus albidus were found to be associated with uveitis for the first time, to our knowledge. Conclusion We recommend applying a 1-step diagnostic procedure that incorporates intraocular, specific microbial PCR with serum analyses in tertiary centers to determine the etiology of uveitis. [source] | |||||||||||||||||||||||||