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21.
Poly(9,10-dihydroanthrylenetrimethylene) ( 2 ) comprises a novel chain-type structure in which 9,10-dihydroanthracene units are linked by flexible spacer groups. Upon dehydrogenation with sulfur at elevated temperature, polymer 2 is converted into the corresponding polyanthrylene system 3 . NMR- and UV-spectroscopic data provide firm evidence for the dehydrogenation process. The polymer 3 was subjected to reduction with active lithium, and the resulting polyanions were characterized by NMR spectroscopy and by quenching experiments. It appears that each anthracene unit of the chain can be charged with two electrons.  相似文献   
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We describe a case of a 76-year-old patient with advanced block in the His-Purkjnie system, who underwent implantation of a cardioverter-defibrillator with cardiac resynchronisation therapy. Complete heart block occurred during the insertion of the coronary sinus cathether. The implantation of the left ventricular (LV) lead was impossible due to difficult anatomy of the coronary venous system. The right ventricular pacing caused the further prolongation of the QRS duration and exacerbation of heart failure symptoms. Thus, the LV lead was successfully implanted during the second procedure after the balloon venoplasty of the lateral cardiac vein. The biventricular pacing was successful during 4 months follow-up.  相似文献   
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We carried out transcatheter procedures to close postinfarction ventricular septal defects (PIVSDs) in 19 patients: two had recanalization after surgical closure, and 17 had a primary PIVSD. In three of the latter patients, who had acute PIVSDs, the procedure was carried out in the first 3 weeks after infarction; in the 13 patients with subacute PIVSD, it was carried out 3.5-12 weeks after infarction. There was another procedure in one patient with chronic PIVSD. In total, 22 procedures were completed: 17 using an Amplatzer atrial septal occluder, two using an Amplatzer postinfarction ventricular septal defect occluder, and two using an Amplatzer muscular ventricular septal defect occluder. The procedure was successful in 14 patients: in 11 with subacute PIVSD, one with chronic PIVSD, and two with postsurgical PIVSD. Transcatheter closure of PIVSDs using an Amplatzer atrial septal occluder is probably the treatment of choice in patients undergoing surgery more than 3.5 weeks after myocardial infarction and in those with recanalization after previous surgical closure.  相似文献   
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The t(11;14)(p13;q11) is presumed to arise from an erroneous T-cell receptor delta TCRD V(D)J recombination and to result in LMO2 activation. However, the mechanisms underlying this translocation and the resulting LMO2 activation are poorly defined. We performed combined in vivo, ex vivo, and in silico analyses on 9 new t(11;14)(p13;q11)-positive T-cell acute lymphoblastic leukemia (T-ALL) as well as normal thymocytes. Our data support the involvement of 2 distinct t(11;14)(p13;q11) V(D)J-related translocation mechanisms. We provide compelling evidence that removal of a negative regulatory element from the LMO2 locus, rather than juxtaposition to the TCRD enhancer, is the main determinant for LMO2 activation in the majority of t(11;14)(p13;q11) translocations. Furthermore, the position of the LMO2 breakpoints in T-ALL in the light of the occurrence of TCRD-LMO2 translocations in normal thymocytes points to a critical role for the exact breakpoint location in determining LMO2 activation levels and the consequent pressure for T-ALL development.  相似文献   
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The aim of this study was to assess the effects of early thymoglobulin administration on cardiocyte nuclear status in orthotopic heart transplant (OHT) recipients. MATERIAL AND METHODS: We investigated endomyocardial biopsies (EMBs) from 31 OHT recipients and 10 control cases. OHT patients were divided into the standard group who were treated without thymoglobuline; an ATG group who received thymoglobulin electively, and a standard+ATG group who were administered thymoglobulin upon a drop in renal function. We evaluated only EMBs obtained at 1 and 4 weeks after OHT showing no significant rejection (ISHLT grades 0 to 1B). The morphometric studies were performed using a computerized, automated Quantimet image analysis system. Overall, 1750 cardiocyte nuclei were quantitated for area, length, breadth, perimeter, chromatin median grey level, and fullness factor. Statistical analysis was performed using the Mann- Whitney U test, the Wilcoxon test, and discriminant analysis. RESULTS: All OHT groups showed significantly higher values (indicating nucleus enlargement) than the control group. All factors suggesting myocardial hypertrophy were significantly higher in the standard group; however, they decreased significantly with time. In contrast, the nuclear geometric parameters were significantly lower and stable throughout the study in the ATG group. The results of the standard+ATG group were intermediate, and their normalization as incomplete at the week 4 examination. Discriminant analysis revealed the closest Mahalanobis distance between control and ATG groups both at and weeks 1 and 4 after OHT. CONCLUSION: Thymoglobulin administered early after surgery protected cardiocyte hypertrophy in heart transplant recipients, mitigating graft ischemic damage.  相似文献   
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Cardiocyte nucleus shape as an indicator of heart graft aging   总被引:1,自引:1,他引:0  
Morphometric publications based on the measurement of cardiocyte nuclei indicated their progressive hypertrophy ignoring, however, their shape, which is a deciding factor for the microscopic-based diagnosis of hypertrophy. We sought was to demonstrate how the shapes of cardiocyte nuclei change over time and correlate them with the thickness of the interventricular septum, (IVS) the biopsy site. MATERIAL: We evaluated myocardial biopsies taken in the first week, first month, and then annually until posttransplant year 10. Only biopsies with no rejection were considered: grade "0" ISHLT (122 biopsies). The control group encompassed fragments from seven donor hearts. METHODS: Cardiomyocyte nuclei were evaluated morphometrically. We calculated the length, breadth, perimeter, roundness, elongation, and fullness factors for correlation with the IVS thickness, and selected indices. The relationships between karyometry and IVS thickness (measured by ultrasound) as well as time were calculated by Spearman's correlation test. RESULTS: Among the examined indices, only nuclear length did not correlate significantly with follow-up time. Among the remaining indices, the strongest correlations with time were observed with regard to breadth (r = 0.214), perimeter (r = 0.150), roundness (r = -0.06) and fullness (r = 0.06), and finally elongation (r = 0.02). The decreasing thickness of the interventricular septum (r = -0.31) showed a weak correlation only with the cardiocyte nuclear length (r = -0.05). CONCLUSION: Graft aging imitates hypertrophy inasmuch as cardiocyte nuclei become wider despite the decreased thickness of the interventricular septum. Therefore, karyometric measurements do not reflect myocardial morphology.  相似文献   
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