871 resultados para cumulative abnormal returns
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A case is presented of extensive alveolar bone grafting in a patient with bilateral cleft lip and palate and polyostotic fibrous dysplasia. The patient previously underwent bisphosphonate therapy. Because of an abnormal and often decreased bone turnover caused by the fibrous dysplasia and the bisphosphonate therapy, bone grafting in such a patient poses several potential difficulties. In addition, the histomorphometric analysis of the bone grafts showed markedly decreased bone turnover. However, alveolar bone grafting using the iliac crest was performed successfully. Sufficient occlusion was achieved by postoperative low-loading orthodontic treatment.
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Catheter ablation of ventricular tachycardia (VT) is effective and particularly useful in patients with frequent defibrillator interventions. Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT. Noninducibility is the most frequently used end point but is associated with significant limitations, so the optimal end point remains unclear. We hypothesized that elimination of local abnormal ventricular activities (LAVAs) during sinus rhythm or ventricular pacing would be a useful and effective end point for substrate-based VT ablation. As an adjunct to this strategy, we used a new high-density mapping catheter and frequently used epicardial mapping.
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We show the impact of migration type on real wages over time. We create a migration and earnings history from the National Longitudinal Survey of Youth over the period 1979-2002. We estimate the effects of primary, onward, and two types of return migration on real wages using a panel data model with individual, location, and time fixed effects. Panel data are well suited for the study of the returns to U.S. internal migration because the influence of migration on wages has been found to occur years after the event. We differentiate return migration into two types: return to a location with ties that form a geographical anchor (home) and return to a prior place of work. We find that real wage growth varies by migration type. Education attainment is a significant factor in real wage growth. Our results show that onward migration is an important channel by which the monetary rewards to a college education are manifested.
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Effectively assessing subtle hepatic metabolic functions by novel non-invasive tests might be of clinical utility in scoring NAFLD (non-alcoholic fatty liver disease) and in identifying altered metabolic pathways. The present study was conducted on 39 (20 lean and 19 obese) hypertransaminasemic patients with histologically proven NAFLD {ranging from simple steatosis to severe steatohepatitis [NASH (non-alcoholic steatohepatitis)] and fibrosis} and 28 (20 lean and eight overweight) healthy controls, who underwent stable isotope breath testing ([(13)C]methacetin and [(13)C]ketoisocaproate) for microsomal and mitochondrial liver function in relation to histology, serum hyaluronate, as a marker of liver fibrosis, and body size. Compared with healthy subjects and patients with simple steatosis, NASH patients had enhanced methacetin demethylation (P=0.001), but decreased (P=0.001) and delayed (P=0.006) ketoisocaproate decarboxylation, which was inversely related (P=0.001) to the degree of histological fibrosis (r=-0.701), serum hyaluronate (r=-0.644) and body size (r=-0.485). Ketoisocaproate decarboxylation was impaired further in obese patients with NASH, but not in patients with simple steatosis and in overweight controls. NASH and insulin resistance were independently associated with an abnormal ketoisocaproate breath test (P=0.001). The cut-off value of 9.6% cumulative expired (13)CO(2) for ketoisocaproate at 60 min was associated with the highest prediction (positive predictive value, 0.90; negative predictive value, 0.73) for NASH, yielding an overall sensitivity of 68% and specificity of 94%. In conclusion, both microsomal and mitochondrial functions are disturbed in NASH. Therefore stable isotope breath tests may usefully contribute to a better and non-invasive characterization of patients with NAFLD.
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It is of interest in some applications to determine whether there is a relationship between a hazard rate function (or a cumulative incidence function) and a mark variable which is only observed at uncensored failure times. We develop nonparametric tests for this problem when the mark variable is continuous. Tests are developed for the null hypothesis that the mark-specific hazard rate is independent of the mark versus ordered and two-sided alternatives expressed in terms of mark-specific hazard functions and mark-specific cumulative incidence functions. The test statistics are based on functionals of a bivariate test process equal to a weighted average of differences between a Nelson--Aalen-type estimator of the mark-specific cumulative hazard function and a nonparametric estimator of this function under the null hypothesis. The weight function in the test process can be chosen so that the test statistics are asymptotically distribution-free.Asymptotically correct critical values are obtained through a simple simulation procedure. The testing procedures are shown to perform well in numerical studies, and are illustrated with an AIDS clinical trial example. Specifically, the tests are used to assess if the instantaneous or absolute risk of treatment failure depends on the amount of accumulation of drug resistance mutations in a subject's HIV virus. This assessment helps guide development of anti-HIV therapies that surmount the problem of drug resistance.
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Angiopoietin-2 (Ang2) is among the relevant growth factors induced by hypoxia and plays an important role in the initiation of retinal neovascularizations. Ang2 is also involved in incipient diabetic retinopathy, as it may cause pericyte loss. To investigate the impact of Ang2 on developmental and hypoxia-induced angiogenesis, we used a transgenic mouse line overexpressing human Ang2 in the mouse retina. Transgenic mice displayed a reduced coverage of capillaries with pericytes (-14%; p < 0.01) and a 46% increase of vascular density of the capillary network at postnatal day 10 compared to wild type mice. In the model of oxygen-induced retinopathy (OIR), Ang2 overexpression resulted in enhanced preretinal (+103%) and intraretinal neovascularization (+29%). Newly formed intraretinal vessels in OIR were also pericyte-deficient (-26%; p < 0.01). The total expression of Ang2 in transgenic mice was seven-fold, compared with wild type controls. Ang2 modulated expression of genes encoding VEGF (+65%) and Ang1 (+79%) in transgenic animals. These data suggest that Ang2 is involved in pericyte recruitment, and modulates intraretinal, and preretinal vessel formation in the eye under physiological and pathological conditions.
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Scrapie is a transmissible spongiform encephalopathy (TSE) in sheep and goats. In recent years, atypical scrapie cases were identified that differed from classical scrapie in the molecular characteristics of the disease-associated pathological prion protein (PrP(sc)). In this study, we analyze the molecular and neuropathological phenotype of nine Swiss TSE cases in sheep and goats. One sheep was identified as classical scrapie, whereas six sheep, as well as two goats, were classified as atypical scrapie. The latter revealed a uniform electrophoretic mobility pattern of the proteinase K-resistant core fragment of PrP(sc) distinct from classical scrapie regardless of the genotype, the species, and the neuroanatomical structure. Remarkably different types of neuroanatomical PrP(sc) distribution were observed in atypical scrapie cases by both western immunoblotting and immunohistochemistry. Our findings indicate that the biodiversity in atypical scrapie is larger than expected and thus impacts on current sampling and testing strategies in small ruminant TSE surveillance.
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Matrilins are oligomeric extracellular matrix adaptor proteins mediating interactions between collagen fibrils and other matrix constituents. All four matrilins are expressed in cartilage and mutations in the human gene encoding matrilin-3 (MATN3) are associated with different forms of chondrodysplasia. Surprisingly, however, Matn3-null as well as Matn1- and Matn2-null mice do not show an overt skeletal phenotype, suggesting a dominant negative pathomechanism for the human disorders and redundancy/compensation among the family members in the knock-out situation. Here, we show that mice lacking both matrilin-1 and matrilin-3 develop an apparently normal skeleton, but exhibit biochemical and ultrastructural abnormalities of the knee joint cartilage. At the protein level, an altered SDS-PAGE band pattern and a clear up-regulation of the homotrimeric form of matrilin-4 were evident in newborn Matn1/Matn3 and Matn1 knock-out mice, but not in Matn3-null mice. The ultrastructure of the cartilage matrix after conventional chemical fixation was grossly normal; however, electron microscopy of high pressure frozen and freeze-substituted samples, revealed two consistent observations: 1) moderately increased collagen fibril diameters throughout the epiphysis and the growth plate in both single and double mutants; and 2) increased collagen volume density in Matn1(-/-)/Matn3(-/-) and Matn3(-/-) mice. Taken together, our results demonstrate that matrilin-1 and matrilin-3 modulate collagen fibrillogenesis in cartilage and provide evidence that biochemical compensation might exist between matrilins.
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Type 1 diabetes is an immuno-inflammatory condition which increases the risk of cardiovascular disease, particularly in young adults. This study investigated whether vascular function is altered in mice prone to autoimmune diabetes and whether the nitric oxide (NO)-cyclic GMP axis is involved. Aortic rings suspended in organ chambers and precontracted with phenylephrine were exposed to cumulative concentrations of acetylcholine. To investigate the role of NO, some experiments were performed in the presence of either 1400W (N-(3-aminomethyl)benzyl-acetamidine hydrochloride), a selective inhibitor of the iNOS-isoform, L-NAME (N(G)-nitro-L-arginine methyl ester hydrochloride), an inhibitor of all three NOS-isoforms, or ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one), a selective inhibitor of guanylate cyclase. Moreover, contractility to phenylephrine, big endothelin-1, and endothelin-1 was assessed and histological analysis and iNOS immunohistochemistry were performed. Endothelium-dependent relaxation was reduced in prediabetic NOD mice (78+/-4 vs. 88+/-2%, respectively, P<0.05 vs. control) despite normal plasma glucose levels (n.s. vs. control). Preincubation with 1400W further attenuated responses in prediabetic (P<0.05 vs. untreated) but not in diabetic or in control mice. In contrast, basal NO bioactivity remained unaffected until the onset of diabetes in NOD mice. Contractile responses to big endothelin-1 and endothelin-1 were reduced in prediabetic animals (P<0.05 vs. control), whereas in diabetic mice only responses to big endothelin-1 were decreased (P<0.05 vs. control). These data demonstrate that endothelium-dependent and -independent vascular function in NOD mice is abnormal already in prediabetes in the absence of structural injury. Early proinflammatory activation due to iNOS in diabetes-prone NOD mice appears to be one of the mechanisms contributing to impaired vasoreactivity.
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OBJECTIVE: The objective of this study was to analyze the autonomic functions of patients with erythrophobia. METHODS: Forty patients with a diagnosis of erythrophobia (female/male ratio 18/22) without any other organic lesions and 20 healthy volunteers (female/male ratio 10/10) were assessed. Clinical evaluation was performed using a modified version of semistructured interviews. Autonomic testing was performed by means of spectral analysis of heart rate and continuous blood pressure by sparse discrete Fourier transformation at rest and under mental stress. RESULTS: There were no significant difference between the two samples in age, sex distribution, BMI, resting systolic, or diastolic blood pressure, nor was there a difference in autonomic baseline functioning between the 40 patients with erythrophobia and the control subjects. On the other hand, patients with erythrophobia consistently showed higher pulse rates (88 +/- 20 vs. 78 +/- 9 bpm, p <.05), higher total heart rate power values (8.40 +/- 0.63 vs. 8.07 +/- 1.02 p <.05), higher midfrequency spectral values (7.38 +/- 0.66 vs. 7.02 +/- 1.18, p <.01), higher high-frequency spectral values (6.89 +/- 0.86 vs. 6.48 +/- 1.44, p <.05), and lower baroreceptor sensitivity (8.62 +/- 8.16 vs. 11.65 +/- 4.42, p <.005) than the healthy subjects. ANOVA showed a significant group interaction (p <.0001) between the samples. CONCLUSIONS: This study provides evidence for abnormal autonomic functioning in patients with erythrophobia when under mental stress.
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BACKGROUND: Empirical antibiotic therapy is based on patients' characteristics and antimicrobial susceptibility data. Hospital-wide cumulative antibiograms may not sufficiently support informed decision-making for optimal treatment of hospitalized patients. METHODS: We studied different approaches to analysing antimicrobial susceptibility rates (SRs) of all diagnostic bacterial isolates collected from patients hospitalized between July 2005 and June 2007 at the University Hospital in Zurich, Switzerland. We compared stratification for unit-specific, specimen type-specific (blood, urinary, respiratory versus all specimens) and isolate sequence-specific (first, follow-up versus all isolates) data with hospital-wide cumulative antibiograms, and studied changes of mean SR during the course of hospitalization. RESULTS: A total of 16 281 isolates (7965 first, 1201 follow-up and 7115 repeat isolates) were tested. We found relevant differences in SRs across different hospital departments. Mean SRs of Escherichia coli to ciprofloxacin ranged between 64.5% and 95.1% in various departments, and mean SRs of Pseudomonas aeruginosa to imipenem and meropenem ranged from 54.2% to 100% and 80.4% to 100%, respectively. Compared with hospital cumulative antibiograms, lower SRs were observed in intensive care unit specimens, follow-up isolates and isolates causing nosocomial infections (except for Staphylococcus aureus). Decreasing SRs were observed in first isolates of coagulase-negative staphylococci with increasing interval between hospital admission and specimen collection. Isolates from different anatomical sites showed variations in SRs. CONCLUSIONS: We recommend the reporting of unit-specific rather than hospital-wide cumulative antibiograms. Decreasing antimicrobial susceptibility during hospitalization and variations in SRs in isolates from different anatomical sites should be taken into account when selecting empirical antibiotic treatment.
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BACKGROUND: Childhood acute lymphoblastic leukemia (ALL) with current cure rates reaching 80% emphasizes the necessity to determine treatment related long-term effects. The present study examines the prevalence of and the risk factors for overweight and obesity in a cohort of ALL survivors treated and living in the French speaking part of Switzerland. METHODS: In this retrospective two-center study, height and weight of 54 patients diagnosed with ALL in first complete remission and treated with chemotherapy only were recorded at specified time points during treatment and off-therapy. Body mass index (BMI) and its age- and gender-adjusted standard deviation score (BMI-SDS) were calculated for the patients and their parents separately. Overweight and obesity were defined by a threshold of BMI-SDS >1.645 and BMI-SDS >1.96, respectively. RESULTS: At last follow-up, 16 (30%) of the 54 survivors were overweight and 10 (18%) were obese. The off-treatment period was most at risk with 11 of the 16 becoming overweight and 9 of the 10 becoming obese during that period. Overweight/obesity at diagnosis and abnormal maternal BMI were significantly associated with abnormal weight at follow-up, while age at diagnosis, gender, cumulative dose of steroids and paternal BMI showed no association. CONCLUSIONS: Consistent with published evidence from other regions of the developed and developing world, there is a significant prevalence of obesity in young ALL survivors in the French speaking part of Switzerland. Factors significantly associated with this late effect were mostly related to the familial background rather than to the treatment components.