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Kang EM Zickler PP Burns S Langemeijer SM Brenner S Phang OA Patterson N Harlan D Tisdale JF 《Experimental hematology》2005,33(6):699-705
The treatment of type I diabetes by islet cell transplantation, while promising, remains restricted due to the incomplete efficacy and toxicity associated with current immunosuppression, and by limited organ availability. Given reports suggesting bone marrow derived stem cell plasticity, we sought to determine whether such cells could give rise to pancreatic islet cells in vivo. In the context of autoimmune diabetes, we transplanted unfractionated bone marrow from beta-gal trangenic donor mice into NOD mice prior to, at, and two weeks beyond the onset of disease. Successful bone marrow engraftment before diabetes onset prevented disease in all mice and for 1 year after transplant. However, despite obtaining full hematopoietic engraftment in over 50 transplanted mice, only one mouse became insulin independent, and no beta-Gal positive islets were detected in any of the mice. To test whether tolerance to islets was achieved, we injected islets obtained from the same allogeneic donor strain as the hematopoietic cells into 4 transplant recipients, and 2 had a reversion of their diabetes. Thus allogeneic bone marrow transplantation prevents autoimmune diabetes and tolerizes the recipient to donor islet grants, even in diabetic animals, yet the capacity of bone marrow derived cells to differentiate into functional islet cells, at least without additional manipulation, is limited in our model. 相似文献
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Hisao Matsuda Abdul Shokor Parwani Philipp Attanasio Martin Huemer Alexander Wutzler Florian Blaschke Wilhelm Haverkamp Leif-Hendrik Boldt 《Heart and vessels》2016,31(9):1544-1552
Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since CF varies in the beating heart, atrial rhythm during RFCA may influence CF. A high-density map and RFCA points were obtained in 25 patients undergoing RFCA of AF using a CF-sensing catheter (Tacticath, St. Jude Medical). The operators were blinded to the CF information. Contact type was classified into three categories: constant, variable, and intermittent contact. Average CF and contact type were analyzed according to atrial rhythm (SR vs. AF) and anatomical location. A total of 1364 points (891 points during SR and 473 points during AF) were analyzed. Average CFs showed no significant difference between SR (17.2 ± 11.3 g) and AF (17.2 ± 13.3 g; p = 0.99). The distribution of points with an average CF of ≥20 and <10 g also showed no significant difference. However, the distribution of excessive CF (CF ≥40 g) was significantly higher during AF (7.4 %) in comparison with SR (4.2 %; p < 0.05). At the anterior area of the right inferior pulmonary vein (RIPV), the average CF during AF was significantly higher than during SR (p < 0.05). Constant contact was significantly higher during AF (32.2 %) when compared to SR (9.9 %; p < 0.01). Although the average CF was not different between atrial rhythms, constant contact was more often achievable during AF than it was during SR. However, excessive CF also seems to occur more frequently during AF especially at the anterior part of RIPV. 相似文献
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Programmed cell death, also known as apoptosis, is frequently initiated when cells are deprived of specific trophic factors. To investigate if accelerated apoptosis contributes to the pathogenesis of Diamond- Blackfan anemia (DBA), a rare pure red blood cell aplasia of childhood, we studied the effect of erythropoietin (epo) deprivation on erythroid progenitors and precursors from the bone marrow of DBA patients as compared with hematologically normal controls. Apoptosis in response to epo deprivation was evaluated by enumeration of colony-forming unit- erythroid (CFU-E)- and burst-forming unit-erythroid (BFU-E)-derived colonies in plasma clot semisolid culture and by the identification of typical DNA oligosomes by gel electrophoresis from marrow mononuclear cells in liquid culture. In all DBA patients there was a marked decrease in CFU-E- and BFU-E-derived colony formation compared with normal controls at comparable time points of epo deprivation, with a complete loss of CFU-E-derived colonies in semisolid culture by 9 hours of epo deprivation versus 48 hours in controls. The BFU-E-derived colony response to epo deprivation displayed a similar pattern of decrement. Apoptotic changes assessed by the presence of characteristic DNA fragmentation began in the absence of epo deprivation and were readily detected within 3 hours of epo deprivation in DBA cultures versus 9 hours in controls. We conclude that DBA is characterized by accelerated apoptosis as measured by the loss of erythroid progenitor clonogenicity and increased progenitor and precursor DNA fragmentation leading to the formation of characteristic oligosomes, consistent with an intrinsic erythroid-progenitor defect in which increased sensitivity to epo deprivation results in erythroid failure. 相似文献
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Prior JO Allenbach G Valenta I Kosinski M Burger C Verdun FR Bischof Delaloye A Kaufmann PA 《European journal of nuclear medicine and molecular imaging》2012,39(6):1037-1047