Risiko-Chancen-Analyse mit Value at Risk bei Investitionsentscheidungen

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Lineare Programmierung mit What's Best

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MR-plastination-arthrography: A new technique used to study the distal tibiofibular syndesmosis

Purpose: The purpose of this study was to describe a new technique called MR plastination arthrography to study both intra- and extra-articular anatomy. Materials and methods: In six human cadaveric lower legs MR arthrography was performed in either a one-step or two-step procedure. In the former a mixture of diluted Gadolinium and dyed polymer was injected. In the latter the dyed polymer was injected after arthrography wih diluted Gadolinium. Three-millimeter slices of these legs, obtained in a plane identical to that of the MR images, were plastinated according to the E12 technique of von Hagens. The plastination slices were subsequently compared with the MR images. Results: The one-step procedure resulted in an inhomogeneous arthrogram. The two-step procedure resulted in a good correlation between the high-resolution MR images and plastination slices, as expressed by a good comparison of anatomic detail of the small syndesmotic recess. Conclusions: Images of the distal tibiofibular syndesmosis obtained with plastination arthrography correlated well with images acquired by MR arthrography when performed in a two-step procedure

Radial distribution function of semiflexible polymers

We calculate the distribution function of the end--to--end distance of a semiflexible polymer with large bending rigidity. This quantity is directly observable in experiments on single semiflexible polymers (e.g., DNA, actin) and relevant to their interpretation. It is also an important starting point for analyzing the behavior of more complex systems such as networks and solutions of semiflexible polymers. To estimate the validity of the obtained analytical expressions, we also determine the distribution function numerically using Monte Carlo simulation and find good quantitative agreement.Comment: RevTeX, 4 pages, 1 figure. Also available at http://www.cip.physik.tu-muenchen.de/tumphy/d/T34/Mitarbeiter/frey.htm

Molecular and Serological Intraocular Fluid Analysis of Coxiella burnetii-seropositive Patients with Concurrent Idiopathic Uveitis

Purpose: Previous studies have suggested a link between Q fever and uveitis. We determined whether Coxiella burnetii causes intraocular infection in C. burnetii-seropositive patients with idiopathic uveitis. Methods: From a retrospective observational case series, paired aqueous humor and serum samples from 10 C. burnetii-seropositive patients with idiopathic uveitis were examined for intraocular antibody production by using the Goldmann-Witmer coefficient and by polymerase chain reaction (PCR). Results: Although intraocular IgG against C. burnetii was detected, no intraocular antibody production was observed (low Goldmann Wittmer coefficients). All PCR results were negative. Conclusions: Uveitis due to an intraocular infection with C. burnetii is unlikely

Large cell neuroendocrine carcinoma with a solitary brain metastasis and low Ki-67:a unique subtype

INTRODUCTION: Stage IV large cell neuroendocrine carcinoma (LCNEC) of the lung generally presents as disseminated and aggressive disease with a Ki-67 proliferation index (PI) 40-80%. LCNEC can be subdivided in two main subtypes: the first harboring TP53/RB1 mutations (small cell lung carcinoma (SCLC)-like), the second with mutations in TP53 and STK11/KEAP1 (non-small cell lung carcinoma (NSCLC)-like). Here we evaluated 11 LCNEC patients with only a solitary brain metastasis and evaluate phenotype, genotype and follow-up. METHODS: Eleven LCNEC patients with solitary brain metastases were analyzed. Clinical characteristics and survival data were retrieved from medical records. Pathological analysis included histomorphological analysis, immunohistochemistry (pRB and Ki-67 PI) and next generation sequencing (TP53, RB1, STK11, KEAP1 and MEN1). RESULTS: All patients had N0 or N1 disease. Median overall survival (OS) was 12 months (95% confidence interval (CI) 5.5-18.5 months). Mean Ki-67 PI was 59% (range 15-100%). In 6/11 LCNEC Ki-67 PI was ≤40%. OS was longer for Ki-67 ≤40% compared to >40% (17 months (95% CI 11-23 months) vs. 5 months (95% CI 0.7-9 months), p=0.007). Two patients were still alive at follow-up after 86 and 103 months, both had Ki-67 ≤40%. 8/11 patients could be subclassified and both SCLC-like (n=6) and NSCLC-like (n=2) subtype were present. No MEN1 mutation was found. CONCLUSION: Stage IV LCNEC with a solitary brain metastasis and N0/N1 disease show in the majority of cases Ki-67 PI ≤40% and prolonged survival, distinguishing them from general LCNEC. This unique subgroup can be both of the SCLC-like and NSCLC-like subtype

The effect of functional roles on perceived group efficiency during computer-supported collaborative learning

In this article, the effect of functional roles on group performance and collaboration during computer-supported collaborative learning (CSCL) is investigated. Especially the need for triangulating multiple methods is emphasised: Likert-scale evaluation questions, quantitative content analysis of e-mail communication and qualitative analysis of open-ended questions were used. A comparison of fourty-one questionnaire observations, distributed over thirteen groups in two research conditions – groups with prescribed functional roles (n = 7, N = 18) and nonrole groups (n = 6, N = 23) – revealed no main effect for performance (grade). Principal axis factoring of the Likert-scales revealed a latent variable that was interpreted as perceived group efficiency (PGE). Multilevel modelling (MLM) yielded a positive marginal effect of PGE. Most groups in the role condition report a higher degree of PGE than nonrole groups. Content analysis of e-mail communication of all groups in both conditions (role n = 7, N = 25; nonrole n = 6, N = 26) revealed that students in role groups contribute more ‘coordination’ focussed statements. Finally, results from cross case matrices of student responses to open-ended questions support the observed marginal effect that most role groups report a higher degree of perceived group efficiency than nonrole groups

Incidence, prevalence, and trajectories of repetitive conduction patterns in human atrial fibrillation

AIMS: Repetitive conduction patterns in atrial fibrillation (AF) may reflect anatomical structures harbouring preferential conduction paths and indicate the presence of stationary sources for AF. Recently, we demonstrated a novel technique to detect repetitive patterns in high-density contact mapping of AF. As a first step towards repetitive pattern mapping to guide AF ablation, we determined the incidence, prevalence, and trajectories of repetitive conduction patterns in epicardial contact mapping of paroxysmal and persistent AF patients. METHODS AND RESULTS: A 256-channel mapping array was used to record epicardial left and right AF electrograms in persistent AF (persAF, n = 9) and paroxysmal AF (pAF, n = 11) patients. Intervals containing repetitive conduction patterns were detected using recurrence plots. Activation movies, preferential conduction direction, and average activation sequence were used to characterize and classify conduction patterns. Repetitive patterns were identified in 33/40 recordings. Repetitive patterns were more prevalent in pAF compared with persAF [pAF: median 59%, inter-quartile range (41-72) vs. persAF: 39% (0-51), P < 0.01], larger [pAF: = 1.54 (1.15-1.96) vs. persAF: 1.16 (0.74-1.56) cm2, P < 0.001), and more stable [normalized preferentiality (0-1) pAF: 0.38 (0.25-0.50) vs. persAF: 0.23 (0-0.33), P < 0.01]. Most repetitive patterns were peripheral waves (87%), often with conduction block (69%), while breakthroughs (9%) and re-entries (2%) occurred less frequently. CONCLUSION: High-density epicardial contact mapping in AF patients reveals frequent repetitive conduction patterns. In persistent AF patients, repetitive patterns were less frequent, smaller, and more variable than in paroxysmal AF patients. Future research should elucidate whether these patterns can help in finding AF ablation targets

Association between High Levels of Blood Macrophage Migration Inhibitory Factor, Inappropriate Adrenal Response, and Early Death in Patients with Severe Sepsis

Background.Identification of new therapeutic targets remains an imperative goal to improve the morbidity and mortality associated with severe sepsis and septic shock. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and counterregulator of glucocorticoids, has recently emerged as a critical mediator of innate immunity and experimental sepsis, and it is an attractive new target for the treatment of sepsis. Methods.Circulating concentrations of MIF were measured in 2 clinical trial cohorts of 145 pediatric and adult patients who had severe sepsis or septic shock caused predominantly by infection with Neisseria meningitidis or other gram-negative bacteria, to study the kinetics of MIF during sepsis, to analyze the interplay between MIF and other mediators of sepsis or stress hormones (adrenocorticotropic hormone and cortisol), and to determine whether MIF is associated with patient outcome. Results.Circulating concentrations of MIF were markedly elevated in 96% of children and adults who had severe sepsis or septic shock, and they remained elevated for several days. MIF levels were correlated with sepsis severity scores, presence of shock, disseminated intravascular coagulation, urine output, blood pH, and lactate and cytokine levels. High levels of MIF were associated with a rapidly fatal outcome. Moreover, in meningococcal sepsis, concentrations of MIF were positively correlated with adrenocorticotropic hormone levels and negatively correlated with cortisol levels and the cortisol : adrenocorticotropic hormone ratio, suggesting an inappropriate adrenal response to sepsis. Conclusions.MIF is markedly and persistently up-regulated in children and adults with gram-negative sepsis and is associated with parameters of disease severity, with dysregulated pituitary-adrenal function in meningococcal sepsis, and with early deat

Luminal narrowing after percutaneous transluminal coronary angioplasty. A study of clinical, procedural, and lesional factors related to longterm angiographic outcome

Background. The renarrowing process after successful percutaneous transluminal coronary angioplasty (PTCA) is now believed to be caused by a response-to-injury vessel wall reaction. The magnitude of this process can be assessed by the change in minimal lumen diameter (MLD) at follow-up angiography. The aim of the present study was to find independent patient-related, lesion-related, and procedure-related risk factors for this luminal narrowing process. A model that accurately predicts the amount of luminal narrowing could be an aid in patient or lesion selection for the procedure, and it could improve assessment of medium-term (6 months) prognosis. Modification or control of the identified risk factors could reduce overall restenosis rates, and it could assist in the selection of patients at risk for a large loss in lumen diameter. This population could then constitute the target population for pharmacological intervention studies. Methods and Results. Quantitative angiography was performed on 666 successfully dilated lesions at angioplasty and at 6-month follow-up. Multivaria