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Tetsuya Kato

Publications and source records attributed to Tetsuya Kato.

9 recordsLinked to original sources
PubMed2006

Design, synthesis, and biological evaluation of indole derivatives as novel nociceptin/orphanin FQ (N/OFQ) receptor antagonists.

A novel series of 2-(1,2,4-oxadiazol-5-yl)-1H-indole derivatives as nociceptin/orphanin FQ (N/OFQ) receptor antagonists was discovered. Systematic modification of our original lead by changing the pendant functional groups, linker, heterocyclic core, and basic side chain revealed the structure-activity requirements for this novel template and resulted in the identification of more potent analog with improved potency as compared to the parent compound.

Animals↗
PubMed2004

Statin blocks Rho/Rho-kinase signalling and disrupts the actin cytoskeleton: relationship to enhancement of LPS-mediated nitric oxide synthesis in vascular smooth muscle cells.

We previously demonstrated statins to enhance cytokine-mediated nitric oxide (NO) synthesis in vascular smooth muscle cells (VSMC). To clarify the mechanism by which this occurs, we evaluated the effects of fluvastatin in lipopolysaccharide (LPS)-stimulated VSMC. NO production induced by LPS was dose-dependently enhanced by fluvastatin, as were iNOS mRNA levels and iNOS protein expression. Exogenous mevalonate and geranylgeranylpyrophosphate (GGPP) dampened the stimulatory effect of fluvastatin. A pull-down assay demonstrated fluvastatin to decrease levels of GTP-bound Rho A. Moreover, a Rho-kinase inhibitor, Y-27632, was observed to enhance LPS-induced NO production. We recently demonstrated that disrupting F-actin formation dramatically potentiates the ability of LPS to induce iNOS mRNA and protein expression. In the present study, staining of F-actin with nitrobenzoxadiazole (NBD)-phallacidin demonstrated that fluvastatin significantly impairs F-actin stress fiber formation. In light of these results, the ability of statins to increase NO production is due, at least in part, to their ability to block the biosynthesis of mevalonate, thereby preventing isoprenoid biosynthesis. This inhibits Rho/Rho-kinase signalling and, in turn, disrupts the actin cytoskeleton. Further analysis of the signalling pathway by which the actin cytoskeleton affects iNOS expression might yield new insight into mechanisms of regulation of NO production.

Actins↗
PubMed2004

Risk factors for vitamin D deficiency in patients with Crohn's disease.

BACKGROUND: Although the pathogenesis of osteopenia in Crohn's disease is not established, vitamin D deficiency is thought to be an important risk factor. However, little is known about the prevalence of vitamin D deficiency in patients with Crohn's disease in Japan. This study aimed to clarify the prevalence of vitamin D deficiency in patients with Crohn's disease in Japan and to examine the possible causes of the deficiency. METHODS: We investigated serum 25-hydroxyvitamin D (25-OHD) levels, various laboratory parameters, and patient histories in 33 outpatients (25 men, 8 women; median age, 37 years; range, 26-57 years) and 15 age- and sex-matched healthy controls (8 men, 7 women; median age, 37 years; range, 24-57 years) and assessed risk factors for vitamin D deficiency. RESULTS: Although patients with Crohn's disease did not have significantly lower serum concentrations of 25-OHD than controls, 9 of 33 patients (27.3%) were considered vitamin D deficient (serum 25-OHD level </=10 ng/ml) compared with only 1 of 15 (6.7%) controls. Serum 25-OHD levels were significantly related to disease duration ( r = 0.46, P = 0.003), Crohn's Disease Activity Index (CDAI) score ( r = 0.44, P = 0.005), International Organization for the Study of Inflammatory Bowel Disease score ( r = 0.30, P < 0.05), and serum values of ferritin ( r = 0.34, P = 0.03), C-reactive protein ( r = 0.34, P = 0.03), total cholesterol ( r = 0.31, P = 0.04), and intact parathyroid hormone ( r = 0.23, P < 0.05). A logistic regression analysis was performed to investigate the ability of variables to predict low or normal 25-OHD values. Results showed that disease duration ( P = 0.03) and CDAI score ( P = 0.04) could predict the occurrence of vitamin D deficiency ( r(2) = 0.472, P = 0.0004). CONCLUSIONS: Vitamin D deficiency exists in patients with Crohn's disease in Japan. 25-OHD levels should be assessed in patients who have had Crohn's disease for a long time (>15 years) and who have been in the active stage of the disease for long periods.

Adult↗
PubMed2004

Sabellaria tottoriensis n. sp. (Annelida: Polychaeta: Sabellariidae) from shallow water off Tottori, the Sea of Japan.

A new species of the genus Sabellaria Lamarck, 1812 (Annelida: Polychaeta: Sabellariidae), is described from shallow water off Tottori, the Sea of Japan. Sabellaria tottoriensis n. sp., is gregarious with tubes constructed of sand and shell debris. The new species is distinguished by the character combination of 1 or 2 pairs of nuchal spines, two forms (long and short) of opercular paleae in the middle row, with the slender blades of long ones recurved outward. Detailed morphological features of the species are described and compared with other Japanese and worldwide congeners.

Animals↗
PubMed2003

Endoscopic diagnosis and staging of mucinous cystic neoplasms and intraductal papillary-mucinous tumors.

BACKGROUND/PURPOSE: The number of patients with cystic neoplasms of the pancreas as detected using various types of imaging techniques has been steadily increasing. Among the cystic neoplasms, mucinous cystic neoplasms (MCNs) and intraductal papillary-mucinous tumors (IPMTs) were comparatively more frequently encountered. We used imaging techniques to focus on the differential diagnosis of MCNs and IPMTs, and tumor staging. METHODS: Fifteen patients with MCNs with ovarian-like stroma and 109 patients with IPMTs were experienced. We examined the image findings for the differential diagnosis and stage diagnosis of these two types of cystic neoplasms. RESULTS: Endoscopic ultrasonography could reveal detailed images of internal structure and was effective for the diagnosis of MCNs. Other endoscopic imaging modalities could not give specific findings for MCNs. Endoscopic retrograde cholangiopancreatography (ERCP; including duodenoscopic findings and pancreatogram) and pancreatoscopy showed the characteristic and specific findings of IPMTs. Also, endoscopic ultrasonography and intraductal ultrasonography were found to have high sensitivity and diagnostic accuracy for their differential diagnosis of neoplastic/nonneoplastic and invasive/noninvasive lesions in IPMTs. CONCLUSIONS: Endoscopic imaging techniques are capable of revealing the detailed structure of pancreatic cystic lesions. They are effective for differential diagnosis, for assessing the degree of malignancy, and for deciding upon an appropriate treatment in patients with IPMTs.

Adult↗
PubMed2003

A two-step method for marking polypectomy sites in the colon and rectum.

BACKGROUND: Intraoperative localization of polypectomy sites is critical for laparoscopic and open surgery, but conventional methods of marking the colorectum are sometimes unreliable. A new two-step method for marking polypectomy sites for identification during laparoscopic and open operations is described. METHODS: Eighteen patients with postpolypectomy lesions necessitating preoperative marking were enrolled in this study. A physiologic saline solution was endoscopically injected into the submucosa to produce an artificial submucosal elevation (pseudopolyp). A small volume of India ink was then injected into the submucosal elevation (pseudopolyp) with a separate needle. RESULTS: The two-step method was easily applied for all lesions without complication. At surgery, all lesions were immediately visualized. CONCLUSION: The two-step tattooing method proved to be easy, safe, and accurate for marking polypectomy sites.

Aged↗
PubMed2003

[Effect of angiotensin II type 1 receptor antagonist on oxidative stress markers in type 2 diabetic patients with hypertension].

Oxidative stress may play a critical role in the pathogenesis of endothelial dysfunction in patients with diabetes or hypertension. An angiotensin II type 1 receptor(AT1) antagonist candesartan is now a widely used antihypertesive drug, and AT1 activation is a predominant source of oxidative stress. We studied the effect of a 12-week treatment of candesartan(4-12 mg-day) on oxidative stress markers [lipid peroxidation(LPO), malondialdehyde-modified LDL(MDA-LDL), 8-epi-PGF2 alpha, and the generation of superoxide anion by monocytes(CLA-DCL)] in 30 type 2 diabetic patients with hypertension (> 140/85 mmHg). Both MDA-LDL and CLA-DCL were significantly decreased, although the others were not changed. These data suggest that candesartan clinically improves oxidant stress, probably lowering the generation of superoxide anion from blood monocytes.

Angiotensin Receptor Antagonists↗