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

Dengue virus type 2 unresponsive to the current PCR primer; : construction of a new PCR primer to detect all strains of Dengue virus type 2.

We found that one strain of dengue virus (Trinidad 1751; TR) did not respond to the PCR primer for Jamaica/83. We investigated such property with other 10 strains of dengue virus type 2 and found 2 more unresponsive strains. All 3 strains were isolated from the central America. To detect the envelope gene of those 3 strains by PCR, we synthesized primers based on TR strain as the reference sequence. Using these primers, we could detect the 3 strains by PCR at the usual annealing temperature. We recommed the new primer for diagnosis of DEN 2

DNA methylation status of REIC/Dkk-3 gene in human malignancies

The REIC (reduced expression in immortalized cells)/Dkk-3 is down-regulated in various cancers and considered to be a tumor suppressor gene. REIC/Dkk-3 mRNA has two isoforms (type-a,b). REIC type-a mRNA has shown to be a major transcript in various cancer cells, and its promoter activity was much stronger than that of type-b. In this study, we examined the methylation status of REIC/Dkk-3 type-a in a broad range of human malignancies. We examined REIC/Dkk-3 type-a methylation in breast cancers, non-small-cell lung cancers, gastric cancers, colorectal cancers, and malignant pleural mesotheliomas using a quantitative combined bisulfite restriction analysis assay and bisulfate sequencing. REIC/Dkk-3 type-a and type-b expression was examined using reverse transcriptional PCR. The relationships between the methylation and clinicopathological factors were analyzed. The rate of REIC/Dkk-3 type-a methylation ranged from 26.2 to 50.0% in the various primary tumors that were examined. REIC/Dkk-3 type-a methylation in breast cancer cells was significantly heavier than that in the other cell lines that we tested. REIC/Dkk-3 type-a methylation was inversely correlated with REIC/Dkk-3 type-a expression. There was a correlation between REIC/Dkk-3 type-a and type-b mRNA expression. REIC/Dkk-3 type-a expression was restored in MDA-MB-231 cells using 5-aza-2'-deoxycytidine treatment. We found that estrogen receptor-positive breast cancers were significantly more common among the methylated group than among the non-methylated group. REIC/Dkk-3 type-a methylation was frequently detected in a broad range of cancers and appeared to play a key role in silencing REIC/Dkk-3 type-a expression in these malignancies

Elimination of Systematic Error in Diffusion Measurement Using In-situ X-ray Fluorescence Analysis for Liquid Alloys

The objective of the present study is to quantify and eliminate the error factors in the measurement of diffusion coefficients in liquid alloys by using in-situ X-ray fluorescence analysis (in-situ XRF). Averaging effect, initial mass transport, and matrix effect were investigated. The impurity diffusion coefficient of Bi in liquid Sn was measured at 573 K using a combination of the long capillary technique and in-situ XRF. The apparent diffusion coefficient was obtained as the time-series data by fitting an analytical solution of Fick’s second law to the temporal variation in Bi concentration in the capillary. In the present measurement, matrix effect did not induce a significant error in the measured diffusion coefficient. Averaging effect can be eliminated by convoluting the analytical solution with the distribution of the X-ray fluorescence intensity scanned from the rod sample. Furthermore, the initial mass transport can be eliminated by shifting the point of time origin to the latter time in the temporal variation in the measured concentration by fitting the analytical solution. By performing the above corrections, the systematic error in the measured diffusion coefficient can be reduced