An Alternative Approach for Radiofrequency Catheter Ablation for Intra-atrial Reentrant Tachycardia Associated with Open-Heart Surgery

We present case reports of 2 patients with scar-related intra-atrial reentrant tachycardia (IART) associated with previous open-heart surgeries, in which standard ablation strategies failed to eliminate atrial tachycardia (AT). The strategies targeted a narrow conducting channel between the right atrial scars or between the scar and inferior vena cava. In these patients, an alternative approach to transect another narrow conducting pathway between the scar and crista terminalis (CT), which was revealed by a noncontact mapping system, successfully terminated and eliminated the IART. Both the cases were free of recurrent AT at the 24-and 25-month follow up visits, respectively. Transection of the corridor between the CT and the incision scar appears to be an effective technique for eliminating scar-related IART and can be considered as a second-line procedure for radiofrequency catheter ablation to eliminate IART

Coenzyme Q10 suppresses apoptosis of mouse pancreatic beta-cell line MIN6

Background: In mitochondrial diabetes, apoptosis of β-cells caused by mitochondrial stress plays an important role in impaired insulin secretion. Several studies have reported that coenzyme Q10 (CoQ10) has therapeutic effects on mitochondrial diabetes, but no reports have examined the fundamental effectiveness or mechanism of CoQ10 in mitochondrial diabetes. We previously reported in a Japanese article that CoQ10 has protective effects on pancreatic β-cells against mitochondrial stress using mouse pancreatic β-cell line MIN6 and staurosporine (STS). Here, we report that CoQ10 protects MIN6 cells against apoptosis caused by STS and describe the more detailed apoptotic cascade. Methods: Apoptosis of MIN6 cells was induced by 0.5 μM STS treatment for specific periods with or without 30 μM CoQ10. The apoptosis cascade in MIN6 cells was then investigated using WST-8 assays, annexin-V staining, western blotting, and DNA degradation analysis. Results: Sixteen hours of 0.5 μM STS treatment led to 47% cell viability, but pretreatment with 30 μM CoQ10 resulted in significantly higher viability of 76% (P < 0.01). CoQ10 also prevented translocation of phosphatidylserine from the inner leaflet to the outer leaflet of the cell membrane. CoQ10 prevented cytochrome c release from mitochondria and activation of caspase-3. Conclusion: We concluded that CoQ10 protects pancreatic β-cells through anti-apoptotic effects against STS treatment

Soft x-ray irradiation induced metallization of layered TiNCl

We have performed soft x-ray spectroscopy in order to study the photoirradiation time dependence of the valence band structure and chemical states of layered transition metal nitride chloride TiNCl. Under the soft x-ray irradiation, the intensities of the states near the Fermi level (EF) and the Ti3+ component increased, while the Cl 2p intensity decreased. Ti 2p–3d resonance photoemission spectroscopy confirmed a distinctive Fermi edge with Ti 3d character. These results indicate the photo-induced metallization originates from deintercalation due to Cl desorption, and thus provide a new carrier doping method that controls the conducting properties of TiNCl