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Approaches to investigate adult oligodendrocyte progenitor cells (OPCs) by targeted cell ablation in the rodent central nervous system have been limited by methodological challenges resulting in only partial and transient OPC depletion. We have developed a novel pharmacogenetic model of conditional OPC ablation, eliminating 98.6% of all OPCs throughout the brain. By combining recombinase-based transgenic and viral strategies for targeting OPCs and ventricular-subventricular zone (V-SVZ)-derived neural precursor cells (NPCs), we found new PDGFRA-expressing cells born in the V-SVZ repopulated the OPC-deficient brain starting 12 days after OPC ablation. Our data reveal that OPC depletion induces V-SVZ-derived NPCs to generate vast numbers of PDGFRA+NG2+cells with the capacity to migrate and proliferate extensively throughout the dorsal anterior forebrain. Further application of this novel approach to ablate OPCs will advance knowledge of the function of both OPCs and oligodendrogenic NPCs in health and disease.

Introduction: Our aim was to compare transureteral lithotripsy (TUL) and extracorporeal shock wave lithotripsy (SWL) in the management of upper ureteral calculi larger than 5 mm in diameter. Materials and Methods: Patients who had upper ureteral calculi greater than 5 mm in diameter were enrolled in this clinical trial. The calculi had not responded to conservative or symptomatic therapy. Semirigid ureteroscopy and pneumatic lithotripsy were used for TUL in 52 patients and SWL was performed in 48. Analysis of the calculi compositions was done and the patients were followed up by plain abdominal radiography and ultrasonography 3 month postoperatively. Results: The stone-free rates were 76.9% in the patients of the TUL group and 68.8% in the patients of the SWL group. These rates in the patients with mild or no hydronephrosis were 85.7% and 59.1% for the SWL and TUL groups, respectively. In the TUL group, half of the patients with no hydronephrosis developed upward calculus migration. The stone-free rates were 75.0% and 89.3% for the patients with moderate hydronephrosis and 70.0% and 100.0% for those with severe hydronephrosis in the SWL and TUL groups, respectively. All of the failed cases were treated by double-J stenting and TUL or SWL successfully. There were no serious complications. Upward calculus migration after TUL was more frequent in cases with no hydronephrosis or mild hydronephrosis (41.0%). Conclusion: Upper ureteral calculi smaller than 1 cm can be safely and effectively managed using semirigid ureteroscopy and pneumatic lithotripsy. However, the SWL approach has still its role if an experienced endourologist is not available.