Development of Bioactivity and Pull-out Torque Control Technology on Ti Implant Surface and its Application for Cold Thread Rolled Bone Screw

AbstractThe influence of cold thread rolling conditions and a production method of titania (TiO2) films on surface bioactivity and pull-out torque of a titanium bone screw was investigated. The bone screw with micro surface roughness distribution was formed by cold thread rolling with a pair of parallel dies. The die shape and surface roughness distribution were changed to the 3 grades. The TiO2 films were coated on the surface of the bone screw using anodizing in aqueous solutions (hydro-coating). We introduced the rolled bone screws into tibia of rats for two weeks and examined the effects of the combinations of the surface morphology and the TiO2 film on osteoconductivity in an in-vivo experiment. As the results, it is found that we could control the bioactivity and pull-out torque by controlling the surface roughness at the bottom of the screw root

TDP-43 stabilises the processing intermediates of mitochondrial transcripts

The 43-kDa trans-activating response region DNA-binding protein 43 (TDP-43) is a product of a causative gene for amyotrophic lateral sclerosis (ALS). Despite of accumulating evidence that mitochondrial dysfunction underlies the pathogenesis of TDP-43–related ALS, the roles of wild-type TDP-43 in mitochondria are unknown. Here, we show that the small TDP-43 population present in mitochondria binds directly to a subset of mitochondrial tRNAs and precursor RNA encoded in L-strand mtDNA. Upregulated expression of TDP-43 stabilised the processing intermediates of mitochondrial polycistronic transcripts and their products including the components of electron transport and 16S mt-rRNA, similar to the phenotype observed in cells deficient for mitochondrial RNase P. Conversely, TDP-43 deficiency reduced the population of processing intermediates and impaired mitochondrial function. We propose that TDP-43 has a novel role in maintaining mitochondrial homeostasis by regulating the processing of mitochondrial transcripts

The Role of Radiotherapy for Thymic Carcinoma

Objective: The aim of this study is to evaluate retrospectively the role of radiotherapy for thymic carcinoma. Methods: Between 1973 and 1998, 14 patients with thymic carcinoma were treated at Gunma Prefectural Cancer Center. Two patients who had hematogenous metastasis were excluded from this study, therefore 12 patients were analyzed. The Masaoka staging system was used; four patients were diagnosed with stage III disease and eight patients with stage IV disease. The pathological subtype according to the World Health Organization histological criteria for thymic tumors was squamous cell carcinoma (low-grade histology) in six cases and undifferentiated carcinoma (high-grade histology) in six. Ten patients underwent thoracotomy, and two patients underwent excisional biopsy without thoracotomy. Ten patients (83%) received radiotherapy as a curative intent, and the median dose was 60 Gy. Systemic chemotherapy was administered to four patients (33%), and the majority (75%) of the regimens contained cisplatin. Results: The 3-year overall survival rate was 25%. Histological subtype (low-grade versus highgrade), surgical resection (complete versus incomplete), radiotherapy and chemotherapy were evaluated as prognostic factors in a univariate analysis. Low-grade histology and complete resection were good prognostic factors, although these were not statistically significant. Patients who received radiotherapy had a better outcome than those who did not. The major sites of recurrence were the pleura and pericardium. Recurrence within the radiation field was observed in one of seven patients in whom failure patterns could be evaluated. Conclusion: Complete resection is mandatory if possible. Radiotherapy plays an important role in treating thymic carcinoma in terms of reducing local recurrence and prolonging survival time. Establishment of an innovative treatment protocol that includes chemotherapy is necessary to control intrathoracic relapse and distant metastasis