Developmental expression of renal organic anion transporters in rat kidney and its effect on renal secretion of phenolsulfonphthalein.

Organic anion transporters (OAT1 and OAT3) and multidrug resistance-associated proteins (MRP2 and MRP4) play important roles in anionic drug secretion in renal proximal tubules. Changes in the expression of such transporters are considered to affect the tubular secretion of anionic drugs. The purpose of this study was to elucidate the developmental changes in the expression of OAT1, OAT3, MRP2, and MRP4 and their effects on the tubular secretion of drugs. The mRNA level of each transporter was measured by real-time PCR, and the protein expression was evaluated by Western blotting and immunohistochemical analysis. In addition, the tubular secretion of phenolsulfonphthalein (PSP) in infant (postnatal day 14) and adult rats was estimated based on in vivo clearance study. The protein expression of organic anion transporters were very low at postnatal day 0 and gradually increased with age. In postnatal day 14 rats, the expression of OAT1 and OAT3 seemed to be at almost mature levels, while MRP2 and MRP4 seemed to be at immature levels. Immunohistochemical analysis in the kidney of postnatal day 0 rats revealed OATs on the basolateral membrane and MRPs on the brush-border membrane. At postnatal day 0, the distribution of these transporters was restricted to the inner cortical region, while after postnatal day 14, it was identical to that in adult kidney. An in vivo clearance study revealed that the tubular secretion of PSP was significantly lower in postnatal day 14 rats than adult rats. These results indicate that age-dependent changes in organic anion transporter expression affect the tubular secretion of anionic drugs in pediatric patients.

Aspirin-induced peptic ulcer and genetic polymorphisms.

There are a few studies of the association between genetic polymorphisms and the risks of acetylsalicylic acid (aspirin)-induced ulcer or its complications. Two single nucleotide polymorphisms (SNP) of cyclooxygenase-1 (COX-1), A-842G and C50T, exhibited increased sensitivity to aspirin and had lower prostaglandin synthesis capacity, lacking statistical significance in the association with bleeding peptic ulcer. A recent Japanese study indicated that the number of COX-1-1676T alleles was a significant risk factor for peptic ulcer in users of non-steroidal anti-inflammatory drugs (NSAIDs). There are some genetic polymorphisms for aspirin resistance, such as platelet membrane glycoproteins, thromboxane A2 (TXA2) receptor, platelet activating factor acetylhydrolase and coagulation factor XIII; however, data on the frequency of gastrointestinal (GI) events in these variants are lacking. Carrying the CYP2C9 variants is reported a significantly increased risk of non-aspirin NSAID-related GI bleeding. The polymorphisms of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) have been associated with development of peptic ulcer or gastric cancer. In a recent investigation, carriage of the IL-1beta-511 T allele was significantly associated with peptic ulcer among low-dose aspirin users. Hypoacidity in corpus gastritis related to polymorphisms of pro-inflammatory cytokines seems to reduce NSAIDs or aspirin-related injury. Data on which polymorphisms are significant risk factors for GI events in aspirin users are still lacking and further large-scale clinical studies are required.

Evaluation of response time delay of a pen-tablet system in thin-client computing environments: implications for usability.

Changeover from the traditional paper-based patient records to the computerized patient records has been spreading rapidly in medical facilities. Since ordinary input devices such as a keyboard and mouse are often thought insufficient for the needs of medical workers using electronic patient records (EPR) compared with traditional pens and paper-based patient records, a pen-tablet system (PTS) as a digital pen interface tends to be used instead. On the other hand, with the growing adoption of thin-client computing (TCC) in medical facilities, the usability of PTS with TCC has come to be a concern because of possible reduction of the usability due to delays of response time occurring in TCC environments. To analyze the factors that influence the usability of PTS with TCC, the authors focused on the relationship between length and its scattering of the response time delay. The results indicated that the delay scattering could be a more influencing factor than the delay length itself and that values of the scattering should be within approximately 35 milliseconds for the best usability. This study would provide useful indicators for evaluating the usability of PTS in incorporating it into the EPR system with TCC environments.

Damage to and recovery of coastlines polluted with C-heavy oil spilled from the Nakhodka.

The damage to and recovery of the Japanese coastline from Suzu, Ishikawa Prefecture to Mikuni, Fukui Prefecture was investigated visually over three years after a C-heavy oil spill from the Russian tanker "Nakhodka" in the Japan Sea on January 2, 1997. The beached C-heavy oil tended to remain for a long time on coasts of bedrock and boulder/cobble/pebble but it was removed rapidly from coasts of gravel/sand and man-made structures such as concrete tetrapods. On the coasts of the latter type, wave energy appeared to be the main force removing the oil. One year after the spill, C-heavy oil tended to remain strongly on the sheltered coasts of bedrock and boulder/cobble/pebble. Even on coasts of this type, the contamination was remarkably absent by 2 years after the spill. The concentration levels of polycyclic aromatic hydrocarbons (PAHs) in oil lumps, sand and seawater were monitored during 3 years following the spill. The concentrations of PAHs having 2 or 3 rings decreased more quickly than did those of PAHs having 4 or more rings, suggesting that volatilization was the main cause of the decrease. On the other hand, the concentrations of PAHs having 4 to 6 rings did not start to decrease until 7 months after the spill. The main cause of the decrease seemed to be photolysis. The concentration of BaP in seawater off the polluted coasts was high 1 month after the spill and then decreased. Three years after the spill, the level fell to the sub ng/L level, which was as low as the level in seawater along unpolluted clean coasts in Japan. The concentration of BaP in greenling was higher than the normal level only during the first two months after the spill. These results suggest that the coastlines in Ishikawa and Fukui Prefectures that were polluted with C-heavy oil recovered in 3 years.

Enhancement of Cytotoxicity of Three Apoptosis-inducing Agents Against Human Oral Squamous Cell Carcinoma Cell Line by Benzoxazinotropone.

Tumor-specificity (TS) and anti-inflammatory activity of benzo[b]cyclohept[e][1,4]oxazin-6(11H)-one, generally known as benzoxazinotropone (BOT), have been reported. In order to find a new biological activity, the combination effect of BOT and three apoptosis-inducing agents was investigated. Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and five human oral normal cells (gingival fibroblasts, periodontal ligament fibroblasts, pulp cells, oral keratinocytes and primary gingival epithelial cells) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. TS was evaluated by the ratio of the mean 50% cytotoxic concentration (CC50) against normal oral cells to the one against OSCC cell lines. Synergy was evaluated by CompuSyn software program. Expression of cleaved forms of poly ADP-ribose polymerase and caspsase-3 was evaluated by western blot analysis. BOT induced activation of caspase 3, suggesting the apoptosis induction in HSC-2 OSCC cells. BOT enhanced the cytotoxicity of doxorubicin (DXR) additively and that of curcumin and resveratrol synergistically. On the other hand, BOT did not enhance, but rather inhibit the cytotoxicity of DXR against normal keratinocytes. The present study suggests that BOT may enhance the anti-tumor activity of apoptosis-inducing agents, while reducing its cytotoxicity against normal cells.

Self-Nonself Recognition Activity Extracted from Self-Sterile Eggs of the Ascidian, Ciona intestinalis: (ascidian/fertilization/allo-recognition/acid extract/HPLC).

Eggs of the hermaphrodite, self-sterile ascidian, Ciona intestinalis, were washed with acid seawater (pH 3.2), and the washing solution was then adjusted to pH 8.2. This solution was found to inhibit only the binding of non-autologous sperm to the vitelline coat (VC) of eggs, indicating that it contained self-nonself recognition activity. This activity was heat-stable and insensitive to trypsin, but was destroyed by V-8 protease and α-glucosidase. Both the hydrophobic and hydrophilic components of a lyophilized powder of the extract showed allo-recognizing activity. On TLC, the hydrophobic components gave a major spot of glucose (Glc) and a peptide spot(s) containing mainly glutamic acid and/or glutamine (Glx). The glucosyl conjugate was purified by HPLC and shown to block sperm-egg binding to various extents. Individual peptide subfractions had no inhibitory activity, but in combination they showed inhibitory activity. These findings suggest that the acid extract of Ciona eggs contains a Glc-enriched nonspecific inhibitor of sperm-egg binding, which could be the primary effector of self-incompatibility, and Glx-enriched modulators, which serve as acceptors of allo-sperm. The cooperative interactions of these components may be responsible for the diversity of allo-recognition in Ciona gametes.