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Here we investigated the pathogenesis of deletion mutant mitochondrial (mt)DNA by generating mice with mutant mtDNA carrying a 4696-basepair deletion ([DELTA]mtDNA4696), and by using cytochrome c oxidase (COX) electron micrographs to identify COX activity at the individual mitochondrial level. All mitochondria in tissues with [DELTA]mtDNA4696 showed normal COX activity until [DELTA]mtDNA4696 accumulated predominantly; this prevented mice from expressing disease phenotypes. Moreover, we did not observe coexistence of COX-positive and -negative mitochondria within single cells. These results indicate the occurrence of inter-mitochondrial complementation through exchange of genetic contents between exogenously introduced mitochondria with [DELTA]mtDNA4696 and host mitochondria with normal mtDNA. This complementation shows a mitochondria-specific mechanism for avoiding expression of deletion-mutant mtDNA, and opens the possibility of a gene therapy in which mitochondria possessing full-length DNA are introduced., Author(s): Kazuto Nakada [1, 2, 3, 6]; Kimiko Inoue [1, 5, 6]; Tomoko Ono [1]; Kotoyo Isobe [1]; Atsuo Ogura [5]; Yu-Ichi Goto [4]; Ikuya Nonaka [3]; Jun-Ichi Hayashi (corresponding [...]

Background: This in vitro study aimed to clarify the combined effect of electric toothbrushing and dentifrice on the removal of artificial stain., Material and Methods: Twenty-five bovine incisors were cut at the cervix and the crown was embedded in auto-cured acrylic resin. Specimens were abraded using #240 SiC paper to obtain a flat enamel surface, and 20 specimens were treated with 10% citric acid / 3% ferric chloride solution followed by 1% tannic acid solution to produce surface staining. They were divided into four groups: 1) brushing with an electric toothbrush and whitening dentifrice (group S+B); 2) brushing with an electric toothbrush and fluoride dentifrice (group S+C); 3) brushing with an electric toothbrush and no dentifrice (group S); and 4) no brushing (control group). The remaining five specimens were used as a baseline. Color values ( L* , a* , and b* were measured before brushing (0 min), and at 1 min, 5 min, 10 min, and 20 min using a microscopic area spectrophotometer. The color change ( ΔE ) was calculated by subtracting the baseline values from the final color values obtained at each time point. The data were statistically analyzed using two-way repeated-measures analysis of variance and Tukey's honest significant difference test as a post hoc test ( p <0.05)., Results: The L* values of groups S+B and S+C increased over time ( p <0.05), but no significant differences were observed in group S and the control group at any of the time points ( p >0.05). Groups S+B and S+C demonstrated greater ΔE values than group S., Conclusions: The combination of electric toothbrushing and dentifrice removed the artificial stain more effectively than brushing without dentifrice. However, the stain removal was limited. The two dentifrices evaluated in this study exhibited similar stain removal effects. Key words: Color change, stain removal, dentifrice, electric toothbrush, whitening effect., Competing Interests: Conflict of interest statement: The authors have no financial relationship with any of the companies whose products are included in this article.

Aim: To evaluate the effects of choice of insertion route and ultrathin endoscope types., Methods: This prospective study (January-June 2012) included 882 consecutive patients who underwent annual health checkups. Transnasal esophagogastroduodenoscopy (EGD) was performed in 503 patients and transoral EGD in 235 patients using six types of ultrathin endoscopes. Patients were given a choice of insertion route, either transoral or transnasal, prior to EGD examination. For transoral insertion, the endoscope was equipped with a thin-type mouthpiece and tongue depressor. Conscious sedation was not used for any patient. EGD-associated discomfort was assessed using a visual analog scale (VAS; no discomfort 0- maximum discomfort 10)., Results: Rates of preference for transnasal insertion were significantly higher in male (male/female 299/204 vs 118/117) and younger patients (56.8 ± 11.2 years vs 61.3 ± 13.0 years), although no significant difference was found in VAS scores between transoral and transnasal insertion (3.9 ± 2.3 vs 4.1 ± 2.5). Multivariate analysis revealed that gender, age, operator, and endoscope were independent significant predictors of VAS for transnasal insertion, although gender, age, and endoscope were those for transoral insertion. Further analysis revealed only the endoscopic flexibility index (EFI) as an independent significant predictor of VAS for transnasal insertion. Both EFI and tip diameter were independent significant predictors of VAS for transoral insertion., Conclusion: Flexibility of ultrathin endoscopes can be a predictor of EGD-associated discomfort, especially in transnasal insertion.