No abstract available.

The vectorial transepithelial transport of water and electrolytes in the renal epithelium is achieved by the polarized distribution of various transport proteins in the apical and basolateral membrane. The short-term regulation of transepithelial transport has been traditionally thought to be mediated by kinetic alterations of transporter without changing the number of transporters. However, a growing body of recent evidence supports the possibility that the stimulus-dependent recycling of transporter-carrying vesicles can alter the abundance of transporters in the plasma membrane in parallel changes in transepithelial transport functions. The abundance of transporters in the plasma membrane is determined by net balance between stimulus-dependent exocytic insertion of transporters into and endocytic retrieval of them from the plasma membrane. The vesicular recycling occurs along the tracts of the actin microfilaments and microtubules with associated motors. This review is to highlight the importance of vesicular transport in the short-term regulatory process of transepithelial transport in the renal epithelium. In the short-term regulation of many other renal transporters, vesicular transport is likely to be also involved. Thus, vesicular transport is now emerged as a wide-spread general regulatory mechanism involved in short-term regulation of renal functions.
Animal ; Biological Transport/physiology ; Endocytosis/physiology* ; Epithelial Cells/enzymology* ; Epithelial Cells/cytology* ; Exocytosis/physiol(HCMV)* ; H(+)-Transporting ATP Synthase/metabolism* ; Human ; Sodium Channels/metabolism

PURPOSE: The loss of p16 protein has been frequently detected in breast carcinoma, but genetic alterations are infrequent. CpG islands of methylation within the p16 promotor have been identified as a mechanism that inactivates the p16 expression. The object of this study is to investigate the relationship between the loss of p16 protein and methylation as a molecular mechanism of the p16 gene inactivation in mammary tumorigenesis. METHODS : We performed an immunohistochemical assay of p16 protein in 70 cases of mammary carcinomas, and we tested for DNA methylation of p16 using methylation-specific PCR, and we then analyzed its correlation with the histopathologic variables. RESULTS : Among the 70 cases, the p16 expression was lost in 32 cases (45.7%), which was not significantly correlated with the pathologic variables. Twenty-three cases with and 27 cases without loss of p16 expression were tested for DNA methylation of p16. Twenty-one of the 23 interpretable cases with loss of p16 expression (91%) showed hypermethylation on p16, but there was no hypermethylation in any of the cases that were without the loss of the p16 expression. CONCLUSION: These findings suggest that the loss of the p16 expression is one of the common abnormalities observed in breast carcinoma and that methylation on the 5'CpG island of the p16 promoter is a major process for p16 ink4 inactivation in breast carcinoma.
Breast Neoplasms* ; Breast* ; Carcinogenesis ; CpG Islands ; DNA Methylation ; Genes, p16 ; Methylation ; Polymerase Chain Reaction

BACKGROUND: The 14-3-3 sigma (sigma) protein has a negative regulatory role in the cell cycle progression of the. Down-regulation or overexpression of the 14-3-3 sigma protein has been reported in various human cancers. METHODS: Immunohistochemistry for the 14-3-3 sigma protein was performed in non-neoplastic bile duct cells, intraductal papillary neoplasms of the liver (IPNL), mass-forming intrahepatic cholangiocarcinomas (ICC) and non-papillary extrahepatic cholangiocarcinomas (ECC). We investigated the methylation status of the 14-3-3 sigma gene in 45 cases of these 3 tumor groups. RESULTS: The non-neoplastic bile duct cells demonstrated negative or weakly positive cytoplasmic immunoreactivity for the 14-3-3 sigma protein and no methylation of the 14-3-3 sigma gene. Overexpression as well as negative immunoreactivity associated with hypermethylation of the 14-3-3 sigma protein was observed in 16 (69.6%) of 23 cases of IPNL, in 21 (63.6%) of 33 cases of mass-forming ICC and in 27 (71.1%) of 38 cases of non-papillary ECC. Negative immunoreactivity was increased in the invasive IPNL (4/6, 66.7%), as well as in the poorly differentiated cases of mass-forming ICC (8/12, 66.7%) and the non-papillary ECC (5/8, 62.5%). CONCLUSIONS: The similar rates for the abnormal expression of the 14-3-3 sigma protein among the three groups of biliary neoplasms indicate its general association with biliary carcinogenesis. Furthermore, the loss of the 14-3-3 sigma protein may be involved in the tumor progression and differentiation in the biliary carcinogenesis.
14-3-3 Proteins ; Bile Ducts ; Biliary Tract Neoplasms ; Carcinogenesis ; Cell Cycle ; Cholangiocarcinoma ; Cytoplasm ; Down-Regulation ; Humans ; Immunohistochemistry ; Liver ; Methylation*

This study was performed to produce transgenic Korean native goat (Capra hircus) by laparoscopic embryo transfer (ET) to overcome the limitations of ET performed by laparotomy. Transgenic embryos were produced by DNA pronuclear microinjection of in vivo zygotes. The recipient goats were synchronized for estrus by using an introvaginal progesterone devices as a controlled internal drugreleasing insert (CIDR) for 13 days and injection of 400 IU PMSG 48 h before removal of the insert. Embryos were transferred on day 3 and 4 after removal of the insert. Recipient goats were deprived of feed for 48 h, then suspended in a laparotomy cradle at an angle of 45degrees. After obtaining a sufficient pneumoperitoneum, the laparoscope and forceps were inserted abdominally through 5 mm trocar sleeves. Examination of the ovaries and uterus was performed and then 213 embryos were transferred into the oviducts via the infundibula of 76 recipient goats. To compare pregnancy rates, ET was also performed by laparotomy in 82 recipient goats. The pregnancies in the recipient goats were diagnosed by ultrasound on day 30 after embryo transfer. The pregnancy rate with laparoscopic ET was significantly higher than with ET performed by laparotomy (46.1% vs. 28.6%, p < 0.05). In addition, the pregnancy rates were compared between ovulated and non-ovulated ovaries of the recipient goats in the laparoscopic ET group. No significant difference was observed between the pregnancy rates of ovulated and non-ovulated ovaries (41.3% vs. 33.3%, p < 0.05) suggesting that ET may also be possible in non-ovulated recipients through artificial rupture of Graafian follicles. These results suggest that laparoscopic ET is a highly efficient method for the transfer of goat embryos.
Animals ; Animals, Genetically Modified/*embryology ; Embryo Transfer/methods/*veterinary ; Female ; Goats/*genetics/physiology ; Laparoscopy/*veterinary ; Laparotomy/*veterinary ; Microinjections/veterinary ; Oocytes