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M Kudo

Publications and source records attributed to M Kudo.

At least 37 records · Page 2Linked to original sources
PubMed2001

Renal tubule-specific transcription and chromosomal localization of rat thiazide-sensitive Na-Cl cotransporter gene.

The molecular mechanism underlying the renal expression localization of the thiazide-sensitive Na-Cl cotransporter (TSC) gene was studied. The TSC gene was localized to chromosome 19p12-14. In cultured cells, tissue-specific transcription activity of the 5'-flanking region of the rat rTSC gene (5'FL/rTSC) was demonstrated, and the major promoter region was located between position -580 and -141. To further examine the tissue-specific transcription, transgenic rats harboring the 5'FL/rTSC fused upstream of the LacZ gene were generated. Immunohistochemical analysis clearly showed that LacZ gene expression was co-localized to distal convoluted tubules (DCT) with TSC, indicating that the 5'FL/rTSC regulates the renal tubule-specific TSC expression. Because a transcription factor, HFH-3 (hepatocyte nuclear factor-3/folk head homologue-3), had also been localized to DCT, a possible role of the putative cis-acting element (HFH-3/rTSC, -400/-387 position) for HFH-3 binding in the tissue-specific transcription was examined. Deletion and mutation analyses suggested that transcription of the HFH-3/rTSC was actually responsive to HFH-3, and electrophoretic mobility shift assay showed a direct binding of in vitro synthesized HFH-3 to the HFH-3/rTSC. In conclusion, the rTSC gene is localized to rat chromosome 19p12--24. The transcription regulatory region of the TSC gene confers DCT-specific gene expression. DCT-specific transcription factor HFH-3 may be involved in the renal tubule-specific transcription of TSC gene.

Animals↗
PubMed2001

Mutations in the follicle-stimulating hormone receptor and familial dizygotic twinning.

Concentrations of follicle-stimulating hormone (FSH) have an important role in multiple ovulation. An association has been reported between mutations in the FSH receptor (FSHR) in a family with increased twinning frequency. We sequenced the transmembrane region of FSHR (located on chromosome 2) in 21 unrelated mothers of dizygotic twins and found no differences to the published sequence. A linkage study of 183 sister pairs and trios, in which all sisters had given birth to spontaneous dizygotic twins, excluded linkage to this region of chromosome 2. We conclude that mutations in FSHR are not a common cause of familial dizygotic twinning.

Chromosomes, Human, Pair 2↗
PubMed2001

Sonographic diagnosis of pancreatic islet cell tumor: value of intermittent harmonic imaging.

We describe a case of nonfunctioning islet cell tumor of the pancreas diagnosed preoperatively by intermittent harmonic power Doppler imaging and digital subtraction gray-scale harmonic imaging and the use of the contrast agent SH U 508A (Levovist). Hypervascularity and tumor perfusion were clearly demonstrated with both harmonic imaging techniques in the early arterial phase. Sonographic findings were confirmed by other modalities and by histopathologic examination.

Adenoma, Islet Cell↗
PubMed2001

Mitochondrial K(ATP) channel as an end effector of cardioprotection during late preconditioning: triggering role of nitric oxide.

Nitric oxide (NO) has been implicated in the "second-window" of ischemic preconditioning (PC). However, the identity of the end effector after initiation of preconditioning by NO is not known. It is likely that NO is involved in opening of mitochondrial ATP-sensitive potassium (mitoK(ATP)) channels. We hypothesized that NO is an important trigger for the opening of mitoK(ATP) channels in the late phase of preconditioning and inducible nitric oxide synthase (iNOS) up-regulation via NF kappa B plays a critical role in diazoxide-induced cardioprotection. To examine this, diazoxide (7 mg/kg) was administered to wild-type (WT) mice and mice lacking the gene 24 hours before 40 minutes of global ischemia. Hearts were perfused in a Langendorff mode and effects of activation of mitoK(ATP) channel and other interventions on functional, biochemical and pathological changes in ischemic hearts were assessed. In hearts from WT mice treated diazoxide, left-ventricular-developed pressure, end-diastolic pressure and coronary flow were significantly improved after ischemia/reperfusion (I/R); lactate dehydrogenase (LDH) release was also significantly decreased, while ATP contents were significantly higher. Administration of 5-HD, a specific blocker of mitoK(ATP) channel or l -NAME, an inhibitor of iNOS before I/R, during diazoxide-pretreatment completely blocked the late cardioprotection against ischemia. Late cardioprotection was also blocked by inhibition of either PKC- delta by rottlerin or NF kappa B by DDTC before diazoxide pretreatment. Diazoxide pretreatment significantly increased nuclear translocation of p65 which was blocked by protein kinase C (PKC) or nitric oxide synthase (NOS) inhibition. Diazoxide was totally inefffective in iNOS knockout mice. These results suggest that diazoxide activates NF kappa B via PKC signaling pathway and that leads to iNOS up-regulation after 24 hours. NO which is generated upon ischemic stress triggers the opening of mitoK(ATP)channel as an end effector of cardioprotection during late PC.

Acetophenones↗
PubMed2001

Anti-angiogenic therapy and radioimmunotherapy in colon cancer xenografts.

Angiogenesis is critical to the growth and metastatic process of malignant tumors. An endogenous estrogen metabolite, 2-methoxyestradiol (2-ME), displays anti-angiogenic and anti-tumorigenic effects. The purpose of this investigation was to determine whether exogenously administered 2-ME would enhance the efficacy of radioimmunotherapy (RIT). Experimental RIT with 4.63 MBq of 131I-A7, an IgG1 anti-colorectal monoclonal antibody, was conducted in mice xenografted with LS 180 human colon cancer cells. 2-ME suspended in 0.5% carboxymethylcellulose was administered daily at a dose of 75 mg/kg per day. 2-ME administration suppressed tumor growth and improved the efficacy of RIT in comparison to RIT alone. Tumor volumes on day 13, expressed as a ratio relative to the initial volume, were 12.7 +/- 2.95 in the nontreated control, 4.73 +/- 0.89 with 2-ME, 3.05 +/- 0.37 with RIT and 0.97 +/- 0.20 with RIT+2-ME. Immunohistochemistry of tumor sections stained with an antibody against factor VIII demonstrated a decrease in microvessel number within tumors treated with 2-ME (7.9 +/- 0.8/200x field) as compared with that in control tumors (29.9 +/- 2.5). Cell proliferation assay at increasing concentrations of 2-ME showed direct cytotoxicity of 2-ME in vitro at 5 microM and greater. In conclusion, 2-ME enhanced the efficacy of RIT with 131I-A7 via inhibition of angiogenesis within the xenografts. The direct cytotoxicity of 2-ME appears to have contributed to this improvement. Anti-angiogenic therapy may prolong the dormancy of microscopic metastases while RIT may exterminate this population of cells. Therefore, the combined treatment may improve the therapeutic outcome of patients with disseminated cancer.

2-Methoxyestradiol↗
PubMed2001

A case of disseminated extrahepatic hepatocellular carcinoma after US-guided biopsy and percutaneous ethanol injection therapy.

A case of disseminated extrahepatic hepatocellular carcinoma (HCC) occurring after ultrasound (US)-guided biopsy and percutaneous ethanol injection therapy is presented. A 72-year-old man with hepatitis-C-virus-related cirrhosis underwent percutanous ethanol injection therapy (PEIT) two times with complete remission: the first for moderately-differentiated HCC in segment six (S6), and the second for well-differentiated HCC in another part of S6. Imaging studies including carbon dioxide (CO(2))-US angiography, incremental computed tomography, and dynamic magnet resonance imaging showed that both HCCs were hypovascular. Twenty-one months after the first PEIT and 7 months after the second, a 5.5x4.5 cm extrahepatic mass interfaced with S6 of the liver was detected by imaging studies. The patient underwent surgery for extrahepatic HCC. Grossly, the main tumor was 5.5x4.5 cm with capsule and septum; the disseminated tumors were detected on the surface of the liver, including the right diaphragm and the falx ligamentosa. Histologically, it was moderately- to poorly-differentiated HCC, which, although not attributed to direct track seeding, was suspected of being induced by the percutaneous US-guided biopsy procedure or by PEIT, irrespective of a hypovascular tumor. Further studies may provide insight into the risk factor engendered by these procedures.

Journal Article↗
PubMed2001

A case of localized primary sclerosing cholangitis mimicking intrahepatic bile duct cancer.

A 75-year-old woman with chronic hepatitis was regularly followed-up in our hospital. A computed tomography (CT) scan revealed an obviously enlarged intrahepatic bile duct in the posterior branch of the left lateral segment. Percutaneous cholangiography revealed an enlarged posterior branch of the left lateral segment and a narrow stenotic region at the root of this branch. We diagnosed her as having intrahepatic bile duct cancer, and a left lateral segmentectomy of the liver was performed. However, microscopic examination of the resected specimens revealed peribiliary fibrosis in the stenotic bile duct and other areas of the intrahepatic bile duct with no malignant cells. Thus, the final diagnosis was made to be primary sclerosing cholangitis. We must consider primary sclerosing cholangitis in the differential diagnosis of localized stenosis of the intrahepatic bile duct.

Journal Article↗
PubMed2001

Orexin A and B evoke noradrenaline release from rat cerebrocortical slices.

1. Orexin A and B, recently identified in the rat hypothalamus are endogenous neuropeptide agonists for the G-protein coupled orexin-1 (OX1) and orexin-2 (OX2) receptors. 2. In the present study, we have examined the effects of orexin A, B and raised extracellular K(+) on noradrenaline release from the rat cerebrocortical slice. We have compared this with other sleep-wake-related (excitatory) neurotransmitters; dopamine, glutamate, serotonin and histamine. 3. Neurotransmitter release studies were performed in rat cerebrocortical slices incubated in modified Krebs buffer (with and without Ca(2+)+EGTA 1 mM) with various concentrations of orexin A, B and K(+) for various times. 4. Orexin A and B-evoked (10(-7) M) noradrenaline release was time-dependent reaching a maximum some 10 min after stimulation. K(+) (40 mM) evoked release was also time dependent but reached a maximum after 6 min. Orexin A, B and K(+) stimulation of release was concentration dependent with pEC(50) and E(max) (% of basal) values of 8.74+/-0.32 (1.8 nM) and 263+/-14% and 8.61+/-0.38 (2.4 nM) and 173+/-7% and 1.43+/-0.02 (37 mM) and 1430+/-70%, respectively. Orexin-evoked release was partially extracellular Ca(2+) dependent. 5. Of the other transmitters studied there was a weak orexin A and B stimulation of glutamate release. In contrast K(+) evoked dopamine, glutamate, histamine and serotonin release with pEC(50) and E(max) (% of basal) values of 1.47+/-0.05 (34 mM) and 3430+/-410%, 1.38+/-0.04 (42 mM) and 1240+/-50%, 1.47+/-0.02 (34 mM) and 480+/-10% and 1.40+/-0.05 (40 mM) and 560+/-60% respectively. 6. We conclude that the neuropeptides orexin A and B evoke noradrenaline release from rat cerebrocortical slices.

Animals↗
PubMed2001

Efficacy of triple therapy with rabeprazole for Helicobacter pylori infection and CYP2C19 genetic polymorphism.

BACKGROUND: Rabeprazole is a new, potent, proton pump inhibitor. The metabolism of rabeprazole is less dependent on CYP2C19 genetic polymorphism. METHODS: A total of 102 Helicobacter pylori-positive patients with gastric ulcer were randomly allocated to three groups: rabeprazole 10 mg (RAC10), rabeprazole 20 mg (RAC20) or rabeprazole 40 mg (RAC40) plus amoxicillin 750 mg and clarithromycin 200 mg twice daily for 7 days. CYP2C19 genotype was determined by the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: All-patients-treated-based eradication rates in patients treated with RAC10, RAC20 and RAC40 were 83%, 77% and 90%, respectively, and per protocol-based eradication rates were 83%, 80% and 90%, respectively. The eradication rates in the three groups were not significantly different. There was also no significant difference between the all-patients-treated-based eradication rate in CYP2C19 extensive metabolizers and that in poor metabolizers (86% vs. 77%). Adverse events were 12% in extensive metabolizers and 23% in poor metabolizers, and the difference in these incidence rates was also not statistically significant. CONCLUSIONS: Triple therapy with 10 mg of rabeprazole combined with amoxicillin/clarithromycin is effective for Japanese patients with H. pylori infection, and the H. pylori eradication rate is not affected by CYP2C19 genetic polymorphism.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Vascularity of advanced gastric carcinoma: evaluation by using power Doppler imaging.

BACKGROUND: We investigated the vascularity of advanced gastric adenocarcinomas by using percutaneous power Doppler imaging. METHODS: Seventeen patients with gastric cancer and 10 without a gastric tumor, but with a slightly thick gastric wall in the B-mode ultrasound, were investigated with the use of power Doppler imaging. The color signals of the gastric lesion were graded as follows: 1, no color signals or the same as the surroundings; 2, color signals were slightly increasing; and 3, color signals were obviously increasing. RESULTS: The color signals of three patients were graded 1, those of eight patients were graded 2 and those of six patients were graded 3 in the gastric cancer group. The color signals of all 10 patients without a gastric tumor were grade 1. This difference was statistically significant (P = 0.0002). CONCLUSIONS: Power Doppler imaging showed vascularity of gastric cancer increasing in the majority of patients (14 of 17: 82%). Thus, power Doppler imaging might be a good screening examination method for gastric cancer.

Adenocarcinoma↗
PubMed2001

Multicenter prospective analysis of newly diagnosed hepatocellular carcinoma with respect to the percentage of Lens culinaris agglutinin-reactive alpha-fetoprotein.

BACKGROUND AND AIM: The Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) has been reported to be a highly useful marker for hepatocellular carcinoma (HCC) compared with a conventional serum AFP concentration, which allows earlier detection of HCC compared with using other imaging modalities and predicting prognosis after therapy. A collaborative prospective study involving nine Japanese hospitals was conducted to analyze the relationships between the tumor characteristics of a HCC patient and the percentage of AFP-L3/AFP total at the initial detection. METHODS: Between 1 October 1996 and 30 September 1997, a total of 388 patients with newly diagnosed HCC were registered. RESULTS: The cut-off level of the percentage of AFP-L3 was altered from 15 to 10%. The AFP-L3-positive HCC patients demonstrated the characteristics of having an advanced tumor, such as the number of tumors, maximum diameter, tumor spread, portal vein invasion, tumor stage, and tumor classification. With the conventional cut-off level of 15% of the percentage of AFP-L3, the malignant characteristics were more definite than that of 10%. However, no significant differences of serum AFP concentration were observed for malignant characteristics such as maximum diameter and histopathological grading. CONCLUSION: Serum AFP concentration does not reveal a malignancy of HCC, however, the AFP-L3-positive HCC has biologically malignant characteristics, especially portal vein invasion and lower tumor classification, and is an advanced tumor regardless of small tumor size and lower serum AFP concentration. As AFP-L3 shows the tumor characteristics, its presence should be an important factor in the determination of therapy and prognosis of patients.

Aged↗
PubMed2001

Classic type of Kaposi's sarcoma and human herpesvirus 8 infection in Xinjiang, China.

We report 17 cases of the classic type of Kaposi's sarcoma in Xinjiang, which is located in the north-western area of China surrounded by Mongolia in the east, Russia in the north and Kazakhstan in the west. Fifteen of the patients were of the Uygur people. All patients were male and did not have acquired immunodeficiency syndrome. Most of the lesions were found in the lower and/or upper extremities, with 16 patients showing multiple lesions. Immunohistochemical examination of the lesions revealed that human herpesvirus 8 (HHV-8)-encoded latency-associated nuclear antigen was expressed in the nuclei of spindle-shaped tumor cells. HHV-8 DNA was detected by polymerase chain reaction in all seven cases examined. Phylogenetic tree analysis revealed that DNA sequences of the HHV-8-encoded K1 gene in the seven Kaposi's sarcoma cases were classified as subtype C that was common in the Mediterranean, the Middle East and East Asian countries. In addition, using immunofluorescence we investigated the seroprevalence of HHV-8 in 73 Uygur patients with diseases other than Kaposi's sarcoma. Surprisingly, the serological study revealed that 34 of the patients (46.6%) were positive for antibodies against HHV-8, suggesting that HHV-8 infection is widespread in Xinjiang area. The occurrence of the classic type of Kaposi's sarcoma with a high seropositivity rate implies that Xinjiang is the most endemic area for HHV-8 infection in the world known to date. Considering that Xinjiang is located at the middle point of the Silk Road that used to extend from Rome to China, these data imply that the virus may have been in circulation in this area due to the migration of the people via the Silk Road.

Adolescent↗