Light-dependent induction of Edn2 expression and attenuation of retinal pathology by endothelin receptor antagonists in Prominin-1- deficient mice

Retinitis pigmentosa (RP) and macular dystrophy (MD) are prevalent retinal degenerative diseases associated with gradual photoreceptor death. These diseases are often caused by genetic mutations that result in degeneration of the retina postnatally after it has fully developed. The Prominin-1 gene (Prom1) is a causative gene for RP and MD, and Prom1- knockout (KO) mice recapitulate key features of these diseases including light-dependent retinal degeneration and stenosis of retinal blood vessels. The mechanisms underlying progression of such degeneration have remained unknown, however. We here analysed early events associated with retinal degeneration in Prom1-KO mice. We found that photoreceptor cell death and glial cell activation occur between 2 and 3 weeks after birth. High-throughput analysis revealed that expression of the endothelin-2 gene (Edn2) was markedly up-regulated in the Prom1-deficient retina during this period. Expression of Edn2 was also induced by light stimulation in Prom1-KO mice that had been reared in the dark. Finally, treatment with endothelin receptor antagonists attenuated photoreceptor cell death, gliosis, and retinal vessel stenosis in Prom1-KO mice. Our findings suggest that inhibitors of endothelin signalling may delay the progression of RP and MD and therefore warrant further study as potential therapeutic agents for these diseases

Comparison of Conventional and New-generation Nickel-Titanium Files in Regard to Their Physical Properties

Introduction This study investigated the surface, fractured structure, and physicochemical properties related to cyclic fatigue in various nickel-titanium (NiTi) files.Methods Among a total of 10 groups of NiTi files, conventional NiTi files (ProFile [Dentsply Maillefer, Ballaigues, Switzerland] and K3 [SybronEndo, Orange, CA]) and new-generation NiTi files (ProFile Vortex [PV; Tulsa Dental Specialties, Tulsa, OK], Vortex Blue [VB; Tulsa Dental Specialties], and K3 XF [XF; SybronEndo, Orange, CA]) with the same tip diameter (ISO size 25) and 2 types of taper (0.04 and 0.06) were used in this study. Scanning electron microscopy of the file surface structure, differential scanning calorimetry, and cyclic fatigue resistance tests were conducted.Results Many mechanical grooves were recognized on the file surface. The surface in the ProFile group was extremely smooth compared with that observed for the other files. Many shallow hollows besides mechanical grooves were noted on the surface in the XF group. A smooth curve was observed in the ProFile, K3, and PV groups. Defined peaks in differential scanning calorimetry were observed in the VB and XF groups. The 0.04 taper files exhibited a statistically higher number of cycles to fracture than the 0.06 taper files in all groups (P <.05). Cracks along the mechanical grooves were observed in the NiTi files, with the exception of the XF group. The start of cracking was detected at U-shape sites in the ProFile group, the cutting edge in the PV and VB groups, and radial islands in the K3 and XF groups.Conclusions The present findings suggest that new-generation NiTi files are not necessarily improved compared with conventional files

Enhanced Auditory Brainstem Response and Parental Bonding Style in Children with Gastrointestinal Symptoms

The electrophysiological properties of the brain and influence of parental bonding in childhood irritable bowel syndrome (IBS) are unclear. We hypothesized that children with chronic gastrointestinal (GI) symptoms like IBS may show exaggerated brainstem auditory evoked potential (BAEP) responses and receive more inadequate parental bonding. = 0.024). Multiple regression analysis in females also supported these findings.It is suggested that children with chronic GI symptoms have exaggerated brainstem responses to environmental stimuli and inadequate parental behaviors aggravate these symptoms

人総研シンポジウム抄録 : 福島原発事故12年の経験から学ぶ -当時小学生だった若者達との対話から(第2回)-

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