Showing papers by "University of Duisburg-Essen published in 2001"
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TL;DR: The use of transesophageal echocardiography to guide the management of atrial fibrillation may be considered a clinically effective alternative strategy to conventional therapy for patients in whom elective cardioversion is planned.
Abstract: Background The conventional treatment strategy for patients with atrial fibrillation who are to undergo electrical cardioversion is to prescribe warfarin for anticoagulation for three weeks before cardioversion. It has been proposed that if transesophageal echocardiography reveals no atrial thrombus, cardioversion may be performed safely after only a short period of anticoagulant therapy. Methods In a multicenter, randomized, prospective clinical trial, we enrolled 1222 patients with atrial fibrillation of more than two days' duration and assigned them to either treatment guided by the findings on transesophageal echocardiography or conventional treatment. The composite primary end point was cerebrovascular accident, transient ischemic attack, and peripheral embolism within eight weeks. Secondary end points were functional status, successful restoration and maintenance of sinus rhythm, hemorrhage, and death. Results There was no significant difference between the two treatment groups in the rate of emboli...
827 citations
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Commonwealth Scientific and Industrial Research Organisation1, National Yang-Ming University2, University of California, Berkeley3, Vrije Universiteit Brussel4, National Institutes of Health5, Radiation Effects Research Foundation6, University of Pisa7, University of Turin8, Third Military Medical University9, University of Auckland10, University of Zagreb11, University of Bologna12, Bhabha Atomic Research Centre13, East Carolina University14, National Academy of Sciences of Belarus15, Sofia Medical University16, Tuscia University17, University of Duisburg-Essen18, National Research Council19, Ghent University20, Istituto Superiore di Sanità21
TL;DR: The best model, which included exposure to genotoxic factors, host factors, methods, and scoring criteria, explained 75% of the total variance, with the largest contribution attributable to laboratory methods.
Abstract: Micronucleus (MN) expression in peripheral blood lymphocytes is well established as a standard method for monitoring chromosome damage in human populations. The first results of an analysis of pooled data from laboratories using the cytokinesis-block micronucleus (CBMN) assay and participating in the HUMN (HUman MicroNucleus project) international collaborative study are presented. The effects of laboratory protocol, scoring criteria, and host factors on baseline micronucleated binucleate cell (MNC) frequency are evaluated, and a reference range of "normal" values against which future studies may be compared is provided. Primary data from historical records were submitted by 25 laboratories distributed in 16 countries. This resulted in a database of nearly 7000 subjects. Potentially significant differences were present in the methods used by participating laboratories, such as in the type of culture medium, the concentration of cytochalasin-B, the percentage of fetal calf serum, and in the culture method. Differences in criteria for scoring micronuclei were also evident. The overall median MNC frequency in nonexposed (i.e., normal) subjects was 6.5 per thousand and the interquartile range was between 3 and 12 per thousand. An increase in MNC frequency with age was evident in all but two laboratories. The effect of gender, although not so evident in all databases, was also present, with females having a 19% higher level of MNC frequency (95% confidence interval: 14-24%). Statistical analyses were performed using random-effects models for correlated data. Our best model, which included exposure to genotoxic factors, host factors, methods, and scoring criteria, explained 75% of the total variance, with the largest contribution attributable to laboratory methods.
409 citations
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TL;DR: In this article, an extensive study of the magnetic reversal mechanism of Fe and Ni nanowires with diameters down to 6 nm is presented, i.e. smaller than the domain wall width, and the activation energy associated with the reversal process is proportional to the cross-section of the wires and nearly independent of the wire length.
253 citations
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TL;DR: Intravascular ultrasound assessment of plaque distribution and vascular remodeling may help to classify plaques with the highest probability of spontaneous rupture.
246 citations
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University of Duisburg-Essen1, Universitaire Ziekenhuizen Leuven2, Praxis3, Aarhus University4, Newcastle University5, University of Würzburg6, University of Amsterdam7, Dresden University of Technology8, University of Greifswald9, Istanbul University10, University of Düsseldorf11, Alberta Children's Hospital12, Medical University of Białystok13, Dokkyo University14, Nagasaki University15, Hochschule Hannover16, Yamaguchi University17, University of Münster18, University of Mainz19
TL;DR: The data indicate that TRPS III is at the severe end of theTRPS spectrum and that it is most often caused by a specific class of mutations in the TRPS1 gene.
Abstract: Tricho-rhino-phalangeal syndrome (TRPS) is characterized by craniofacial and skeletal abnormalities. Three subtypes have been described: TRPS I, caused by mutations in the TRPS1 gene on chromosome 8; TRPS II, a microdeletion syndrome affecting the TRPS1 and EXT1 genes; and TRPS III, a form with severe brachydactyly, due to short metacarpals, and severe short stature, but without exostoses. To investigate whether TRPS III is caused by TRPS1 mutations and to establish a genotype-phenotype correlation in TRPS, we performed extensive mutation analysis and evaluated the height and degree of brachydactyly in patients with TRPS I or TRPS III. We found 35 different mutations in 44 of 51 unrelated patients. The detection rate (86%) indicates that TRPS1 is the major locus for TRPS I and TRPS III. We did not find any mutation in the parents of sporadic patients or in apparently healthy relatives of familial patients, indicating complete penetrance of TRPS1 mutations. Evaluation of skeletal abnormalities of patients with TRPS1 mutations revealed a wide clinical spectrum. The phenotype was variable in unrelated, age- and sex-matched patients with identical mutations, as well as in families. Four of the five missense mutations alter the GATA DNA-binding zinc finger, and six of the seven unrelated patients with these mutations may be classified as having TRPS III. Our data indicate that TRPS III is at the severe end of the TRPS spectrum and that it is most often caused by a specific class of mutations in the TRPS1 gene.
208 citations
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TL;DR: It is demonstrated that a positive AV antibody test in the donor is an important risk factor for AV infection after allogeneic SCT, in addition to well-known risk factors for viral infection after SCT.
Abstract: The incidence of adenovirus (AV) infections following SCT was determined in a prospective multicenter trial. Over 1 year, 130 consecutive patients undergoing allogeneic SCT at Essen University Hospital were included and followed for 6 months. Source of stem cells was blood in 68 cases. Fifty-eight patients had HLA-identical sibling donors. Throat swabs, urine and stool samples were screened weekly for AV antigen and DNA by ELISA and nested PCR, respectively. In 35 cases adenovirus infection was detected. There was no seasonal variation. Throat swabs were positive in 24, urine in 12, and stool in 11 cases, resulting in a cumulative risk of infection of 29%. The incidences of AV infection of the respiratory, gastrointestinal and urinary tract were 19%, 10%, and 9%, respectively, and infections were diagnosed after a median (range) interval of 44 (-2-179), 37 (-2-168), and 53 (17-153) days after transplantation. On multivariate analysis, presence of AV antibody in the donor and acute graft-versus-host disease grade IV were found to be independent risk factors for AV infection. Eleven patients had AV isolated from more than one site and five patients had probable AV disease. We were not able to identify patients in whom AV infection was the leading cause of death. The majority of patients infected with AV suffered from severe acute graft-versus-host disease often accompanied by other opportunistic infections, such as aspergillosis or CMV reactivation. Nineteen out of 36 patients who died during the observation period had AV infection. In summary, AV infection after allogeneic SCT was observed in a substantial number of patients. In addition to well-known risk factors for viral infection after SCT we were able to demonstrate that a positive AV antibody test in the donor is an important risk factor for AV infection. Further studies are needed, however, before final conclusions on the clinical sequelae of AV infection can be made and the role of preventive and therapeutic strategies toward AV infection after allogeneic SCT can be defined.
184 citations
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TL;DR: The prevalence of mutations in the zinc finger transcription factor gene, ZIC2, in a group of 509 unrelated individuals with isolated holoprosencephaly (HPE) and normal chromosomes supports the idea that Z IC2 haploinsufficiency can result in HPE.
Abstract: We report on the prevalence of mutations in the zinc finger transcription factor gene, ZIC2, in a group of 509 unrelated individuals with isolated holoprosencephaly (HPE) and normal chromosomes Overall, we encountered 16 HPE patients (from 15 unrelated families) with ZIC2 mutations Thus, ZIC2 mutation was the apparent cause of HPE in 3-4% of cases Seven mutations were frameshifts that were predicted to result in loss of function, further supporting the idea that ZIC2 haploinsufficiency can result in HPE One mutation, an alanine tract expansion which is caused by the expansion of an imperfect trinucleotide repeat, occurred in seven patients from six different families In three of those families, the father was found to be apparently mosaic for the mutation We hypothesize that this mutation can arise through errors in somatic recombination, an extremely unusual mutation mechanism In addition, one mutation resulted in a single amino acid change and one mutation was an in-frame deletion of 12 amino acids The central nervous system malformations seen in patients with ZIC2 mutations ranged from alobar HPE (most common) to middle interhemispheric fusion defect (one case) Although severe facial anomalies are common in HPE, all of the patients with ZIC2 mutations had relatively normal faces, suggesting that ZIC2 mutations represent a large proportion of HPE cases without facial malformation
176 citations
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TL;DR: The results allow the classification of MEB and WWS as distinct disorders on both clinical and genetic grounds and provide a basis for the mapping of the WWS gene(s).
Abstract: Background: Three rare autosomal recessive disorders share the combination of congenital muscular dystrophy and brain malformations including a neuronal migration defect: muscle–eye-brain disease (MEB), Walker–Warburg syndrome (WWS), and Fukuyama congenital muscular dystrophy (FCMD). In addition, ocular abnormalities are a constant feature in MEB and WWS. Lack of consistent ocular abnormalities in FCMD has allowed a clear clinical demarcation of this syndrome, whereas the phenotypic distinction between MEB and WWS has remained controversial. The MEB gene is located on chromosome 1p32-p34. Objectives: To establish distinguishing diagnostic criteria for MEB and WWS and to determine whether MEB and WWS are allelic disorders. Methods: The authors undertook clinical characterization followed by linkage analysis in 19 MEB/WWS families with 29 affected individuals. With use of clinical diagnostic criteria based on Finnish patients with MEB, each patient was categorized as having either MEB or WWS. A linkage and haplotype analysis using 10 markers spanning the MEB locus was performed on the entire family resource. Results: Patients in 11 families were classified as having MEB and in 8 families as WWS. Strong evidence in favor of genetic heterogeneity was obtained in the 19 families. There was evidence for linkage to 1p32-p34 in all but 1 of the 11 pedigrees segregating the MEB phenotype. In contrast, linkage to the MEB locus was excluded in seven of eight of the WWS families. Conclusion: These results allow the classification of MEB and WWS as distinct disorders on both clinical and genetic grounds and provide a basis for the mapping of the WWS gene(s).
161 citations
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TL;DR: In five patients, all hepatic and pulmonary lesions with a diameter exceeding 8 mm were detected by using thoracic and abdominal helical computed tomography as the reference method.
Abstract: A technique for whole-body magnetic resonance (MR) imaging in only 30 seconds was developed on the basis of a rolling table platform with integrated surface coils and real-time true fast imaging with steady-state precession. In five patients, all hepatic and pulmonary lesions with a diameter exceeding 8 mm were detected by using thoracic and abdominal helical computed tomography as the reference method. Whole-body MR imaging with real-time true fast imaging with steady-state precession is feasible and may be suitable for tumor screening and staging.
151 citations
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TL;DR: Basiximab in combination with cyclosporine, steroids, and azathioprine triple therapy was highly effective in reducing the incidence of acute renal allograft rejection without increasing the incidenceof infections and other side effects.
Abstract: Background A double-blind, placebo-controlled, randomized study was performed to assess whether immunoprophylaxis with basiliximab (Simulect) could reduce the incidence of acute rejection in kidney transplant recipients treated with cyclosporine (Neoral), steroids, and azathioprine. Methods Three hundred forty patients received either placebo or basiliximab at a dose of 20 mg, given intravenously on days 0 and 4. All patients received cyclosporine, steroids, and azathioprine. The primary endpoint was the incidence of acute rejection at 6 months. Secondary endpoints included the safety and tolerability of basiliximab and placebo, 1-year patient and graft survival, and significant medical events up to 12 months. Results During the first 6 months posttransplantation, acute rejection occurred in 20.8% of patients given basiliximab versus 34.9% of patients administered placebo (P=0.005). Similarly, there was a reduction in biopsy-proven acute rejection at 6 months in the patients receiving basiliximab (P=0.023). One-year patient survival was 97.6% with basiliximab and 97.1% with placebo, graft survival was 91.5% versus 88.4%, respectively (NS). The adverse-events profile of patients treated with basiliximab was indistinguishable from that of patients treated with placebo. The number of patients with infections was similar (65.5% for basiliximab vs. 65.7% for placebo), including cytomegalovirus infections (17.3% vs. 14.5%, P=0.245). Nine neoplasms (three in the basiliximab group, six in the placebo arm) were recorded up to 1 year from transplantation. Conclusions Basiliximab in combination with cyclosporine, steroids, and azathioprine triple therapy was highly effective in reducing the incidence of acute renal allograft rejection without increasing the incidence of infections and other side effects.
130 citations
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TL;DR: Cardiac marker elevation can frequently be found after coronary procedures that are associated with a persistent reduction of rCVR, indicating procedural embolization of atherothrombotic debris with microvascular impairment and myocardial injury as a potential underlying mechanism.
Abstract: Background—Residual reduction of relative coronary flow velocity reserve (rCVR) after successful coronary intervention has been related to microvascular impairment. However, the incidence of cardiac enzyme elevation as a surrogate marker of an underlying embolic myocardial injury in these cases has not been studied. Methods and Results—A series of 55 consecutive patients with successful coronary stenting, periprocedural intracoronary Doppler analysis, and determination of creatine kinase (CK; upper limit of normal [ULN] for women 70 IU/L, for men 80 IU/L) and cardiac troponin T (cTnT; bedside test, threshold 0.1 ng/mL) before and 6, 12, and 24 hours after intervention were studied. Postprocedural rCVR was the only intracoronary Doppler parameter that independently correlated with cTnT (r=−0.498, P<0.001) and CK outcome (r=−0.406, P=0.002). Receiver operating characteristic analysis identified a postprocedural rCVR of 0.78 as the best discriminating value, with a sensitivity of 83.3% and 69.2% and a specif...
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TL;DR: Posterior retroperitoneoscopic adrenalectomy is a safe method that has become a standard procedure in endocrine surgery and depends on tumor type, tumor size, gender, and extent of resection.
Abstract: Posterior retroperitoneoscopic adrenalectomy is one of the new endoscopic methods in endocrine surgery In a prospective clinical study 142 posterior retroperitoneoscopic adrenalectomies (72 right, 70 left) were performed in 130 patients (52 males, 78 females, age 491 ± 149 years) Indications were primary adrenal tumors (unilateral, n= 118; bilateral, n= 2), adrenal metastases (n= 2), and bilateral ACTH-dependent hyperplasias (n= 10) Tumor size ranged from 05 to 70 cm (mean 27 ± 14 cm) Partial adrenalectomies were performed in 39 patients Conversion to open posterior adrenalectomy was necessary in five patients and seven procedures (5%) Intraoperative and postoperative complications were minor and occurred in 5% and 13%, respectively Mortality was zero Operating time was 101 ± 39 minutes (range 35–285 minutes) and depended on tumor type (pheochromocytoma versus others; p < 001), tumor size (< 3 vs ≥ 3 cm; p < 005), gender (p < 005), and extent of resection (partial versus complete, p < 005 Twenty-three adrenalectomies (17%) were performed within 1 hour or less Blood loss was 54 ± 72 ml Consumption of analgesics was low (mean 6 mg piritramide postoperatively) Median duration of hospitalization was 3 days Posterior retroperitoneoscopic adrenalectomy is a safe method that has become a standard procedure in endocrine surgery
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TL;DR: As revealed by phylogenetic analyses, orthologs of the T. tenax and P. furiosus enzyme appear to be present in almost all sequenced archaeal genomes, as well as in some bacterial genomes, strongly suggesting that this new enzymeFamily shows no significant sequence similarity to classical Class I and II enzymes.
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TL;DR: A novel effective, acyclic hydrogen-bonding receptor possessing naphthyridine-amide moieties as heterocyclic recognition units has been developed.
Abstract: The synthesis and binding properties for carbohydrates of several artificial, acyclic receptors containing two or three heterocyclic recognition units covalently attached to a phenyl spacer is described. These host molecules having uncharged hydrogen-bonding sites were used in a systematic study towards the evaluation of recognition motifs for carbohydrates. A novel effective, acyclic hydrogen-bonding receptor possessing naphthyridine–amide moieties as heterocyclic recognition units has been developed.
Es werden die Synthesen von kunstlichen, acyclischen Rezeptoren 4–8 und ihre Bindungseigenschaften gegenuber Kohlenhydraten beschrieben. Diese Rezeptorverbindungen enthalten zwei oder drei heterocyclische Erkennungseinheiten, die kovalent uber einen Phenyl-Spacer verbunden sind. Diese Wirtmolekule, die nicht ionische Wasserstoffbruckenbindungs-Gruppen besitzen, wurden fur systematische Studien zur Bestimmung von Erkennungsmotiven fur Kohlenhydrate verwendet. Der neue, effektive, uber Wasserstoffbrucken bindende Rezeptor 4, der Naphthyridin-Amid-Einheiten als heterocyclische Erkennungsstrukturen enthalt, wurde entwickelt.
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TL;DR: A negligible antiaromatic destabilization is found in planar D4h 1,3,5,7-cyclooctatetraene with alternating bond lengths and the delocalized D8h structure, which has a stabilization energy of only 3-4 kcal mol-1.
Abstract: A negligible antiaromatic destabilization is found in planar D4h 1,3,5,7-cyclooctatetraene with alternating bond lengths. The same is also true for the delocalized D8h structure, which has a stabilization energy of only 3-4 kcal mol-1 . According to quantum-chemical calculations, the ground state of 1 is expected to be the planar C2v -symmetric (1,1) singlet diradical 1'.
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TL;DR: It is demonstrated that RA and SLE patients differ in their immune response to stress from healthy controls, and changes in cytokine patterns might be responsible for stress-induced exacerbation of disease activity in RA and Rheumatoid arthritis patients.
Abstract: Objective. To study whether patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) differ from healthy individuals in their immune responses to acute psychological stress. Methods. The phenotype and function of peripheral blood lymphocytes were analysed before and after stress exposure in patients and healthy subjects. Results. Natural killer (NK) cell numbers increased transiently in all groups under stress. NK activity, however, increased in healthy controls only. We observed a stress-induced increase in interleukin (IL)-4-producing (IL-4 + ) cells in SLE patients only, whereas interferon (IFN) c + cell numbers increased due to stress in all three groups. An analysis of supernatants from phytohaemagglutinin (PHA) cultures revealed increased IFNc and IL-10 levels in healthy subjects but not in SLE or RA patients after stress exposure. Conclusions. These data demonstrate that RA and SLE patients differ in their immune response to stress from healthy controls. Changes in cytokine patterns might be responsible for stress-induced exacerbation of disease activity in RA and SLE patients. The pathogenesis of chronic inflammatory autoimmune diseases such as rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) is still unknown. Both inflammatory diseases are characterized by the presence of autoantibodies which play a major role in these entities. In healthy individuals, antibody production is regulated by a well-controlled network of immunocompetent cells predominantly co-ordinated by cytokines. Therefore, several studies have investigated the cytokine profile of SLE and RA patients in vivo and in vitro. Despite the inconsistent findings of either increased or decreased levels of interleukin (IL)-2, IL-4, IL-6, IL-10 or interferon (IFN) c in RA and SLE patients in comparison with healthy controls, these studies confirm that SLE and RA patients display an altered cytokine profile w1‐5x.
01 Jan 2001
TL;DR: Broad access to graphics memory and parallel processing of image operands thus turns the graphics card into an ultrafast vector coprocessor and opens up a wide area of numerical applications for hardware acceleration.
Abstract: Graphics cards exercise increasingly more computing power and are highly optimized for high data transfer volumes. In contrast typical workstations perform badly when data exceeds their processor caches. Performance of scientific computations very often is wrecked by this deficiency. Here we present a novel approach by shifting the computational load from the CPU to the graphics card. We represent data in images and operations on vectors in graphics operations on images. Broad access to graphics memory and parallel processing of image operands thus turns the graphics card into an ultrafast vector coprocessor. The presented strategy opens up a wide area of numerical applications for hardware acceleration. The implementations of Finite Element solvers for the linear heat equation and the anisotropic diffusion method in image processing underline its practicability. We explain the vector processor usage of graphics cards in detail. An extensive correspondence of vector and graphics operations is given and the decomposition of complex operations into hardware supported is explicated. We also sketch the realization of arbitrary number formats in graphics hardware and the consequences of the restricted precision. Finally, we propose slight modifications and extensions which would further improve computational benefits and extend the range of applicability of the proposed approach. Computing in image processing at ms for an Jacobi iteration on images is exemplarily depicted as an ideal field, where Finite Element methods can be greatly accelerated and ultimate number precision is not required.
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TL;DR: In this article, the extinction spectra of the colloidal assemblies generated from clusters exhibited two absorption peaks, caused by excitation of the plasmon resonance along the long and short axes of the wire-like arranged particles.
Abstract: Nanopores in alumina membranes can serve as reaction vessels for the generation of nanosized gold particles. In addition, they enable a quasi one-dimensional arrangement of nanoparticles, the optical properties of which can easily be investigated due to their transparency in the visible and near ultraviolet (UV) regions. Gold colloids inside the pores were produced either by thermal decomposition of [Au55(PPh3)12Cl6] clusters or by loading the pores with preformed colloids. The clusters as well as the colloids were transferred into the pores by simple immersion, and if necessary supported by applying a vacuum. The [Au55(PPh3)12Cl6] clusters were decomposed over the temperature range of 100 to 800 °C, using pores of different diameters. Transmission electron microscopy (TEM) was used to investigate the resulting nanoparticles. At decomposition temperatures up to ca. 500 °C, no specific influence of pore size or temperature was observed: 4–5 nm colloids were formed. However, temperatures > 500 °C resulted in colloids of up to 10–11 nm being formed. The optical properties of these and of preformed gold colloids in the membranes were studied. The extinction spectra of the colloidal assemblies generated from clusters exhibited two absorption peaks, caused by excitation of the plasmon resonance along the long and the short axes of the wire-like arranged particles. The optical extinctions were measured with unpolarized and polarized light (0 and 90°). Depending on the angle of polarization, the polarized light caused either a blue- or a red-shift in the absorption maximum. Theoretical calculations, using the so-called generalized Mie theory and Maxwell Garnet theory, confirmed the experimentally observed behavior of these gold/alumina nanocomposites.
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TL;DR: It is suggested that multiple mutational steps are involved in exostosis development and that EXT genes play a role in cell signaling related to chondrocyte cytoskeleton regulation.
Abstract: The EXT family of putative tumor suppressor genes affect endochondral bone growth, and mutations in EXT1 and EXT2 genes cause the autosomal dominant disorder Hereditary Multiple Exostoses (HME). Loss of heterozygosity (LOH) of these genes plays a role in the development of exostoses and chondrosarcomas. In this study, we characterized EXT genes in 11 exostosis chondrocyte strains using LOH and mutational analyses. We also determined subcellular localization and quantitation of EXT1 and EXT2 proteins by immunocytochemistry using antibodies raised against unique peptide epitopes. In an isolated non-HME exostosis, we detected three genetic hits: deletion of one EXT1 gene, a net 21-bp deletion within the other EXT1 gene and a deletion in intron 1 causing loss of gene product. Diminished levels of EXT1 and EXT2 protein were found in 9 (82%) and 5 (45%) exostosis chondrocyte strains, respectively, and 4 (36%) were deficient in levels of both proteins. Although we found mutations in exostosis chondrocytes, mutational analysis alone did not predict all the observed decreases in EXT gene products in exostosis chondrocytes, suggesting additional genetic mutations. Moreover, exostosis chondrocytes exhibit an unusual cellular phenotype characterized by abnormal actin bundles in the cytoplasm. These results suggest that multiple mutational steps are involved in exostosis development and that EXT genes play a role in cell signaling related to chondrocyte cytoskeleton regulation. Cell Motil. Cytoskeleton 48:149–162, 2001. © 2001 Wiley-Liss, Inc.
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07 May 2001TL;DR: An image and video indexing approach that combines face detection and face recognition methods that is able to discriminate between three different newscasters and an interviewed person is presented.
Abstract: This paper presents an image and video indexing approach that combines face detection and face recognition methods. Images of a database or frames of a video sequence are scanned for faces by a neural network-based face detector. The extracted faces are then grouped into clusters by a combination of a face recognition method using pseudo two-dimensional hidden Markov models and a k-means clustering algorithm. Each resulting main cluster consists of the face images of one person. In a subsequent step, the detected faces are labeled as one of the different people in the video sequence or the image database and the occurrence of the people can be evaluated. The results of the proposed approach on a TV broadcast news sequence are presented. It is demonstrated that the system is able to discriminate between three different newscasters and an interviewed person.
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TL;DR: This study suggests that Glut1DS patients may have a reduced safety margin for methylxanthines, and indicates that caffeine and phenobarbital have similar GlUT1 inhibitory properties in these two subjects.
Abstract: Methylxanthines such as caffeine and theophylline are known to inhibit glucose transport. We have studied such inhibition in the glucose transporter type 1 deficiency syndrome (Glut1DS) by erythrocyte glucose transport assays. Data from four patients with individual mutations in the GLUT1 gene are discussed: patient 1 (hemizygosity), 3 (S66F), 15 (368Ins23), and 17 (R333W). Zero-trans influx of (14)C-labeled 3-O-methyl glucose (3-OMG) into erythrocytes of patients is reduced (patient 1, 51%; 3, 45%; 15, 31%; 17, 52%) compared with maternal controls. Inhibition studies on patients 1, 3, 17, and maternal controls show an IC(50) for caffeine of approximately 1.5 mM both in controls (n = 3) and patients (n = 3) at 5 mM 3-OMG concentration. In the same two groups, kinetic studies show that 3 mM caffeine significantly decreases V(max) (p < 0.005), whereas the decrease in K(m) is significant (p < 0.01) only in the three controls and one patient (patient 3). Kinetic data from individual patients permit us to speculate that the interactions between caffeine and Glut1 are influenced by the mutation. Three mM caffeine also inhibits the transport of dehydroascorbic acid (DHA), another substrate for Glut1. The combined effects of caffeine (3 mM) and phenobarbital (10 mM) on glucose transport, as determined in patient 15 and the maternal control, show no additive or synergistic inhibition. These data indicate that caffeine and phenobarbital have similar Glut1 inhibitory properties in these two subjects. Our study suggests that Glut1DS patients may have a reduced safety margin for methylxanthines. Consumption of methylxanthine-containing products may aggravate the neurologic symptoms associated with the Glut1DS.
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TL;DR: In this paper, the crystal structures of the low-melting 1,2-and 1,3-dichlorobenzene isomers in monoclinic space group P21/n (P21/c), resp., were detd. by x-ray anal.
Abstract: The crystal structures of the low-melting 1,2- and 1,3-dichlorobenzene isomers in monoclinic space group P21/n and monoclinic space group P21/c, resp., were detd. by x-ray anal. and in situ crystn. techniques. Attempts to predict these structures in advance by force-field calcns. were not successful, although the known crystal structures of two of the three polymorphs of the 1,4-isomer were successfully a posteriori predicted. Calcd. lattice energies were supplemented with estd. lattice-vibrational entropies obtained in the rigid-body approxn. Energy calcns. for actual and virtual crystal structures indicate that the higher m.p. of the 1,4-isomer can be largely attributed to more efficient crystal packing.
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01 Jan 2001TL;DR: The automatic analysis of user actions in shared workspaces (action-based collaboration analysis) is regarded as a promising new direction that takes into account the operational grounding of group interactions in the context of collaboratively constructed problem representations.
Abstract: In computer-supported collaborative learning, technology is used for enabling constructive approaches to learning as well as group interaction, particularly in distant and asynchronous situations. Recently, shared workspace systems have been developed that allow for jointly constructing conceptual problem representations by means of graphical structures and direct manipulation as well as the incorporation of existing material and the persistent storage of results. Though these systems feature free and open-ended collaboration, they lack any kind of awareness of relevant group interaction aspects. However, an explicit description of collaboration processes is necessary for monitoring and visualizing group interaction, enabling didactic interventions and intelligent support, empirically investigating human collaboration, and evaluating system design. The automatic analysis of user actions in shared workspaces (action-based collaboration analysis) is regarded as a promising new direction. In contrast to discourse-oriented approaches, it especially takes into account the operational grounding of group interactions in the context of collaboratively constructed problem representations. Based on software engineering considerations, a generic plug-in agent architecture has been developed to generally provide operational semantics and intelligent support for di erent types of user interfaces, particularly shared workspaces. The user interfaces and intelligent components communicate by broadcasting messages that represent the creation, deletion, and modi cation of objects. Realized as an intelligent component, activity recognition automatically and incrementally infers abstract notions of group activity and interpretations of problem-related con icts and coordinations from a stream of action messages. The approach, which is related to plan recognition in the situation calculus, has been formalized based on concepts of basic actions and complex, higher-level activities, situations that reconstruct relevant aspects of the user environment, operators that specify a hierarchy of activities, and pending actions that represent potential subsequent action sequences. Activity recognition does not rely on domain and task knowledge, though it can use possibly available information to improve its results. The results of the interaction analysis are visualized in di erent forms including direct feedback to the shared workspaces. The feasibility of the approach has been veri ed with a number of test subjects in realistic face-to-face sessions, with activity recognition being used for an analysis-based indexing of video recordings.
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TL;DR: Oral riz atriptan 10 mg was more effective than oral sumatriptan, naratripta, and zolmitriptan on stringent outcome measures of pain-free response at 2 hours, symptom-free responded at 2hours, and 24-hour sustained pain- free response.
Abstract: Objective: To compare the efficacy of oral rizatriptan 10 mg with oral doses of sumatriptan, naratriptan, and zolmitriptan on stringent outcome measures. Methods: Retrospective analysis of data from five randomized, placebo-controlled, double-masked clinical trials in which oral rizatriptan was directly compared with oral sumatriptan 100 mg (n = 772), 50 mg (n = 1116), 25 mg (n = 1183), naratriptan 2.5 mg (n = 413), and zolmitriptan 2.5 mg (n = 580) for the acute treatment of a moderate or severe migraine attack. Outcome measures: Percentage of patients pain-free at 2 hours, symptom-free at 2 hours (no pain, nausea, photophobia, phonophobia, vomiting, or functional disability), 24-hour sustained pain-free (no headache at 2 hours, no recurrence, and no additional antimigraine medications for 24 hours). Results: More patients taking rizatriptan 10 mg were pain-free at 2 hours than were patients taking sumatriptan 100 mg (40% vs 33%, p = 0.019), sumatriptan 50 mg (40% vs 35%, p = 0.009), sumatriptan 25 mg (38% vs 27%, p p p = 0.041). More patients taking rizatriptan 10 mg were symptom-free at 2 hours than were patients taking sumatriptan 100 mg (31% vs 22%, p = 0.002), sumatriptan 50 mg (33% vs 28%, p = 0.003), sumatriptan 25 mg (33% vs 24%, p p p = 0.042). More patients taking rizatriptan 10 mg had a 24-hour sustained pain-free response than did patients taking sumatriptan 100 mg (27% vs 23%, p = 0.112), sumatriptan 50 mg (30% vs 26%, p = 0.015), sumatriptan 25 mg (27% vs 20%, p = 0.005), naratriptan 2.5 mg (29% vs 17%, p = 0.004), and zolmitriptan 2.5 mg (32% vs 24%, p = 0.013). Conclusion: Oral rizatriptan 10 mg was more effective than oral sumatriptan, naratriptan, and zolmitriptan on stringent outcome measures of pain-free response at 2 hours, symptom-free response at 2 hours, and 24-hour sustained pain-free response.
01 Jan 2001
TL;DR: This paper proposes some rules of thumb, which allow to modify aspects incrementally and reuse aspect-specific code in AspectJ, and shows how the cooperation of inheritance and aspectual modification is achieved.
Abstract: One of the major benefits of Object-Oriented Programming (OOP) is, that it supports inheritance as a mechanism for code reuse and incremental modification. Wellestablished object-oriented technologies like white-box frameworks make exhaustively use of and intensively rely on inheritance. Aspect-Oriented Programming (AOP) is a new technology, which supports another extension mechanism whose intension is to enable a better separation of concerns. General-purpose aspect languages (GPAL) like AspectJ are build upon object-oriented programming languages, and in that way it is possible to combine both extension mechanisms. This paper shows that both mechanisms are in contradiction to each other. The result is, that the advantages of inheritance are no longer available. Furthermore, incremental modifications and code reuse are not directly supported for the new language features of AspectJ. So, the application of techniques like redefining aspect-specific behavior is not possible. This paper proposes some rules of thumb, which allow to modify aspects incrementally and reuse aspect-specific code in AspectJ. Moreover, this paper shows how in that way the cooperation of inheritance and aspectual modification is achieved.
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TL;DR: A modification of SCTP is proposed and evaluated which significantly enhances the performance in long delay environments and highlights some advantages over TCP.
Abstract: Summary IP-based networks grow rapidly and coexist with other universal basic telecommunication infrastructures, namely with the ISDN, mobile networks and ATM networks. Since all infrastructures are capable of carrying all applications and services, there is a growing need for interworking. To be able to transfer signaling traffic originating in the other networks via IP networks, a family of protocols is being defined based on SCTP, a new end-to-end transport protocol. This paper describes some features of SCTP in detail and highlights some advantages over TCP. In addition, a modification of SCTP is proposed and evaluated which significantly enhances the performance in long delay environments.
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TL;DR: Non-destructive analysis of natural substances in plants as well as of old dyed textiles by Raman spectroscopy has not been possible using conventional techniques, but it is possible to distinguish the main dye component non-destructively by using Raman bands.
Abstract: Non-destructive analysis of natural substances in plants as well as of old dyed textiles by Raman spectroscopy has not been possible using conventional techniques. Exciting lines from the visible part of the spectrum produced photochemical and thermal decomposition of the objects as well as strong fluorescence. Using Nd:YAG laser excitation at 1064 nm together with a special sample arrangement and interferometric recording, various polyacetylenes in Aethusa cynapium and in chamomile (Chamomilla recutita) and the main valuable substances in gentian species (Gentiana lutea and G. punctata), curcuma roots (Curcuma longa), cinnamon (Cinnamomum zeylanicum), fennel (Foeniculum vulgare), clove (Caryophyllus aromaticus), and ginger (Zingiber officinale) were analyzed non-destructively and discussed in comparison with the corresponding pure standard compounds. We further analyzed non-destructively the FT Raman spectra of collections of historical textiles and lakes used for dyeing. It is possible to distinguish the main dye component non-destructively by using Raman bands.
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TL;DR: The authors analyzes whether differences in institutional structures on capital markets contribute to explaining why some OECD-countries, in particular the Anglo-Saxon countries, have been much more successful over the last two decades in producing employment growth and in reducing unemployment than most continental-European OECDcountries.
Abstract: This paper analyzes whether differences in institutional structures on capital markets contribute to explaining why some OECD-countries, in particular the Anglo-Saxon countries, have been much more successful over the last two decades in producing employment growth and in reducing unemployment than most continental-European OECD-countries. It is argued that the often-blamed labor market rigidities alone, while important, do not provide a satisfactory explanation for these differences across countries and over time. Financial constraints are potentially important obstacles against creating new firms and jobs and thus against coping well with structural change and against moving successfully toward the "new economy". Highly developed venture capital markets should help to alleviate such financial constraints. This view that labor-market institutions should be supplemented by capital market imperfections for explaining differences in employment performances is supported by our panel data analysis, in which venture capital turns out to be a significant institutional variable.
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TL;DR: The results of transplantation with mismatched family donors were comparable to those obtained with unrelated donor transplantation, and suggests that nonidentical family donors may be considered if a fully matched unrelated donor is not available.
Abstract: Transplantation with histocompatible identical siblings is a curative treatment for patients with myelodysplastic syndromes (MDS). Alternative treatments, such as transplantation with other family donors, are an option for patients without HLA-identical siblings. This study evaluated transplantation with genotypically nonidentical family donors and compared the results to those obtained with unrelated donors and autologous stem cell transplantation. Overall 3-year survival was 35% for the 79 patients transplanted using genotypically nonidentical donors, DFS was 31%, relapse risk 16%, and the treatment-related mortality (TRM) 62%. Patients transplanted using phenotypically identical family donors had a significantly superior survival and a lower TRM than patients transplanted with mismatched family donors. Age had no influence on the outcome of transplantation. The DFS of patients transplanted in early stage of the disease was 42% compared to 28% in patients transplanted with more advanced disease (P = 0.03). The results of transplantation with mismatched family donors were comparable to those obtained with unrelated donor transplantation. This suggests that nonidentical family donors may be considered if a fully matched unrelated donor is not available. The TRM of patients transplanted with nonidentical family donors is significantly higher than the TRM of patients transplanted with autologous stem cells. The disease-free survival of ASCT is not inferior to allogeneic transplantation using nonidentical family donors, and the intensity of the treatment is much lower. The choice of ASCT or alternative donor transplantation must be influenced by the age of the patient and the risk of relapse. For patients under the age of 20 years the treatment of choice may indeed be an alternative donor transplantation.
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TL;DR: The structures of all new unusual hydrocarbons were proven by X-ray crystal structure analyses, and the most interesting structural and crystal packing features are presented.
Abstract: The prepn., crystal structures, phys. properties, and reactions of spirocyclopropanated bicyclopropylidenes such as I were studied. I was prepd. in three steps and 24% yield from 7-cyclopropylidenedispiro[2.0.2.1]heptane, or, more efficiently, in one step by a dehalogenative coupling of 7,7-dibromo[3]triangulane II (82%). Reductive dimerization was also used successfully in the prepn. of (E)- and (Z)-bis(spiropentylidene) and even of the \"third-generation\" spirocyclopropanated bicyclopropylidene III (17% yield over three steps from II). Whereas the parent bicyclopropylidene dimerized at 180 DegC to yield [4]rotane, dimerization of I at 130 DegC under 10 kbar pressure occurred only with opening of one three-membered ring to yield the polyspirocyclopropanated (cyclopropylidene)cyclopentane deriv. IV in 34% yield; at elevated temp., the polyspirocyclopropanated 2-cyclopropylidene[3.2.2]propellane deriv. V was isolated in 25% yield. I and III underwent addn. of bromine, hydrogen bromide, and various dihalocarbenes to the central double bond without rearrangement. A branched [7]triangulane and a branched dichloro-C2v-[15]triangulane were used to prep. perspirocyclopropanated [3]rotane (D3h-[10]triangulane) VI (in six steps and in 1.4% overall yield from I) and the C2v-[15]triangulane VII (in two steps and in 41% overall yield from III). Catalytic hydrogenation of I yielded 7,7'-bis(dispiro[2.0.2.1]-heptyl) and, under more forcing conditions, 1,1'-bis(2,2,3,3-tetramethylcyclopropyl). The bromofluorocarbene adduct of III reacted with butyllithium to give an unexpected polyspirocyclopropanated cyclopropylidenebicyclohexane deriv. as the main product along with the expected \"third-generation\" perspirocyclopropanated dicyclopropylidenemethane. Mechanistic aspects of the prepn. and reactions of spirocyclopropanated bicyclopropylidenes are discussed. The structures were characterized by X-ray crystal structure anal.; structural and crystal packing features are presented.