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Seikan Hai

Publications and source records attributed to Seikan Hai.

At least 19 recordsLinked to original sources
PubMed2007

Nicorandil elevates tissue cGMP levels in a nitric-oxide-independent manner.

The K(+) channel opener nicorandil is a hybrid compound that contains nitrate in its structure. It has been reported that nicorandil can relax vascular tissue in vitro via a mechanism that involves activation of K(ATP) channels and stimulation of soluble guanylyl cyclase. However, it is not known whether the increase of cGMP levels occurs through an elevation of nitric oxide (NO). The aim of the present study was to determine whether NO release was a direct effect of nicorandil. We reported here that nicorandil did not generate NO using ozone chemiluminescence detection methods in human or rat liver microsomes (P450-rich fractions) with addition of NADPH. However, nicorandil elevated cGMP levels in rat liver, aorta, and human coronary smooth muscle cells in vitro. The elevation was not inhibited by the NO trapping agent carboxy-2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (carboxy-PTIO). These results suggest that nicorandil elevates cGMP without NO generation.

Animals↗
PubMed2006

Clinicopathologic characteristics of hepatitis C virus-associated intrahepatic cholangiocarcinoma.

BACKGROUND: Although hepatitis C virus (HCV) infection is a possible pathogenetic factor for intrahepatic cholangiocarcinoma (ICC), clinicopathologic features of ICC patients with HCV infection remain unclear. PATIENTS AND METHODS: Of 50 patients with ICC treated, 19 were infected with HCV (HCV-positive group) and 38 underwent surgical treatment. Clinicopathologic features and postoperative outcome were compared between patients with and without HCV infection. RESULTS: In 15 patients in the HCV-positive group, ICC was detected during follow-up for chronic hepatitis C. The proportion of patients who underwent curative resection was significantly higher in the HCV-positive than in the HCV-negative group, and tumors were significantly smaller in the HCV-positive than in the HCV-negative group. In the HCV-positive group, tumors were significantly smaller in patients who were followed up for chronic hepatitis C than in patients who were not followed up. Although cumulative survival rates did not differ significantly between groups, prognoses of patients with small ICC were significantly better than those with large ICC. CONCLUSION: Follow-up for patients with chronic hepatitis C by imaging series at regular intervals is important and provides the possibility to detect a small ICC as well as a hepatocellular carcinoma. Resection should be guided by liver function and the tumor stage in patients with HCV-associated ICC.

Adult↗
PubMed2006

Clinical significance of serum cytokeratin-19 fragment (CYFRA 21-1) in hepatocellular carcinoma.

BACKGROUND/PURPOSE: CYFRA 21-1, a soluble fragment of cytokeratin 19, is increased in serum in some patients with hepatocellular carcinoma, but the clinical significance of this increase is still unknown. METHODS: Serum concentrations of CYFRA 21-1 were measured in 240 patients with hepatocellular carcinoma prior to hepatic resection. The relationships between serum CYFRA 21-1 concentrations and clinicopathologic features were analyzed. RESULTS: The sensitivity of CYFRA 21-1 as a test for hepatocellular carcinoma was 18.8%. Serum CYFRA 21-1 was significantly higher in patients with portal vein tumor thrombus, and serum CYFRA 21-1 increased with the progression of portal vein tumor thrombus. Tumor size was related to serum CYFRA 21-1, but there were no significant correlations between serum CYFRA 21-1 concentrations and tumor differentiation or number of tumors. Although patients with stage IV tumor had significantly higher CYFRA 21-1 concentrations than those with stages I, II, and III, CYFRA 21-1 was not associated with postoperative prognosis. CONCLUSIONS: Although high concentrations of CYFRA 21-1 were often detected in patients with a tumor diameter greater than 5 cm or tumor thrombus in the major portal vein, CYFRA 21-1 is not a useful diagnostic tool for hepatocellular carcinoma because of its low sensitivity.

Adult↗
PubMed2006

Immunohistochemical demonstration of c-Kit protooncogene product in gallbladder cancer.

BACKGROUND/PURPOSE: Although some gallbladder carcinomas are immunoreactive for c-Kit, the reasons for the c-Kit expression and its clinicopathologic implications are unknown. METHODS: We investigated the prevalence of c-Kit immunoreactivity, its clinicopathologic correlates (including microvessel density and postoperative outcome), and the possible mechanisms of c-Kit expression. We reviewed retrospectively, the clinicopathologic records of 47 patients who had undergone macroscopically complete gallbladder carcinoma resection. The numbers of patients at pathologic stages I to IV, according to current TNM-based staging, were 10, 5, 18, and 14, respectively. For immunohistochemical examination, we used monoclonal antibodies against c-Kit and CD 34 (progenitor cell markers), cytokeratin 7 and cytokeratin 19 (cholangiocyte markers), and OCH1E5 (a hepatocyte marker). Control tissue samples were from five gallbladder specimens each with chronic cholecystitis, polyp, and adenoma. RESULTS: Cytoplasmic immunostaining for c-Kit was detected in 21 of the 47 gallbladder carcinomas (45%), and in 1 of the 15 control specimens (diagnosis, chronic cholecystitis). Young age was significantly associated with c-Kit positivity; however, there were no significant differences in the incidence of c-Kit positivity among other variables, including tumor stage and outcome. However, microvessel density was significantly higher in c-Kit-positive gallbladder carcinoma compared with c-Kit-negative gallbladder carcinoma. None of the 47 cancer specimens or the 15 control specimens were stained for CD34 and OCH1E5, but all 47 cancer specimens were stained for cytokeratins 7 and 19. CONCLUSIONS: Gallbladder carcinomas positive for c-Kit are unlikely to arise from immature cells, but may be associated with neovascularization. Angiogenesis inhibitors, such as tyrosine kinase inhibitors, therefore, may suppress the growth of some gallbladder cancers.

Adult↗
PubMed2006

Hepatocellular carcinoma arising from nonalcoholic steatohepatitis: report of two cases.

Sporadic cases of hepatocellular carcinoma (HCC) originating from nonalcoholic steatohepatitis (NASH) have recently been reported. Thus, we investigated the prevalence of NASH in patients with HCC. A review of the clinical records of 481 patients who underwent liver resection for HCC in our department between January 1991 and December 2003 revealed only two (0.4%) patients with HCC associated with NASH. Both of these patients had noninsulin-dependent diabetes mellitus, and neither had a history of alcohol consumption or blood transfusion. All serologic markers for hepatitis B and C viruses were negative. Histological examination of the noncancerous hepatic tissue revealed NASH with moderate hepatic fibrosis in one patient and cirrhosis in the other. Thus, clinical follow-up and screening for HCC should be done for patients with hepatic fibrosis caused by NASH, even though this form of hepatitis is an uncommon cause of HCC.

Aged↗
PubMed2005

Immunohistologic attempt to find carcinogenesis from hepatic progenitor cell in hepatocellular carcinoma.

AIM: To clarify whether hepatocellular carcinoma (HCC) originates from hepatic progenitor cells and whether there is any correlation with the clinicopathologic factors of HCC, we reviewed 217 resected HCC specimens. METHODS: Immunohistochemical examination of cytokeratin (CK) 7, CK19, CD34, and CD117 (c-KIT) was performed. Overexpression of CK7 and CK19 indicates differentiation from cholangiocellular and hepatic progenitor cells, while overexpression of CD34 and CD117 indicates hepatic stem cells. Fresh specimens were obtained from 20 HCC patients for mutation of the c-KIT gene. RESULTS: CK7, CK19, and CD117 were positive in 41, 9.7, and 0.9% of the HCC specimens, respectively, and CD34 was never positive. None of the fresh HCC specimens demonstrated a c-KIT mutation. CK19 positivity was significantly correlated with a positive hepatitis B core antibody, and with poor survival outcome, and tended to correlate with poor histologic differentiation. CONCLUSION: These results suggest that: (i) about 10% of HCCs with typical histologic features originate from an intermediate hepatic progenitor cell, such as the canal of Hering and oval cells in the rat, or acquire the characteristics of cholangiocellular epithelium by metaplasia; (ii) HCC with typical histologic features rarely originates from hepatic stem cells, and (iii) patients with CK19-positive HCC have a poor prognosis.

Analysis of Variance↗
PubMed2005

Vitamin E deficiency accelerates nitrate tolerance via a decrease in cardiac P450 expression and increased oxidative stress.

Organic nitrates, such as nitroglycerin (NTG), have been used to relieve the symptoms of angina pectoris. However, their biochemical mechanisms of action, particularly in relation to the development of tolerance, are incompletely defined. It has been reported that supplemental antioxidants such as vitamin E attenuate the development of nitrate tolerance. Therefore, we examined the role of vitamin E in the regulation of nitrate tolerance. Continuous NTG infusion induced nitrate tolerance in rats after 48 h, and vitamin E concentrations decreased in a time-dependent manner in tissues and plasma. Vitamin E supplementation (0.5 g/kg diet) maintained higher concentrations of vitamin E during NTG infusion. The onset and extent of the tolerance, estimated by the decrease in blood pressure following NTG bolus injection during the infusion of NTG, were accentuated in the vitamin E-deficient group. Vitamin E supplementation inhibited nitrate tolerance 48 h after NTG infusion. Cardiac P450 expression (CYP1A2) assessed by immunoblotting, markedly decreased 48 h after NTG administration in control rats. The supplementation of vitamin E significantly attenuated the decrease in P450. Treatment of NTG enhanced vascular superoxide production (L-012 chemiluminescence, DHE fluorescence). The peak of lipid peroxidation and free radical generation in the heart was reached before tolerance developed. In contrast, vitamin E-deficient hearts had lower P450 expression and higher free radical generation than control hearts. To evaluate other vitamin E-inhibitable mechanisms of nitrate tolerance, we studied the NO-cGMP pathway. NTG markedly reduced the vasodilator-stimulated phosphoprotein (VASP) serine 239 phosphorylation (specific substrate of cGMP-activated protein kinase I; cGK-I) in tolerant hearts. Vitamin E inhibited the depletion of pVASP. In conclusion, because continuous NTG infusion causes vitamin E depletion as well as nitrate tolerance, vitamin E deficiency may further accelerate nitrate tolerance via an increase in oxidative stress, the reduced bioconversion because of decreased P450 expression, and impairment of the NO/cGMP pathway in tolerant heart tissues.

Animals↗
PubMed2005

Minoxidil, a K(ATP) channel opener, accelerates DNA synthesis following partial hepatectomy in rats.

A large number of studies have reported the action of K(ATP) channel openers in accelerating the proliferation of hepatocytes and many other cell types in vitro. Few studies, however, have examined the proliferative effect of K(ATP) channel openers in vivo. The aim of this study was to determine whether the K(ATP) channel opener minoxidil accelerates liver regeneration after partial hepatectomy (PH) in vivo. Male Wistar rats underwent a 70% partial hepatectomy (PH) after receiving a subcutaneous injection of minoxidil (0.01 mg/kg or 0.03 mg/kg). Some of the rats were intravenously treated with 5-hydroxydecanoic acid (5-HD, 10 mg/kg) just before the minoxidil injection. Seventy-two hours after PH, DNA synthesis was immunohistochemically assessed by bromodeoxyuridine (BrdU) incorporation into the nuclei. Minoxidil induced significant and dose-dependent increase in the BrdU labeling index after PH, and 5-HD reversed this minoxidil-induced change. Minoxidil did not significantly affect the changes in liver weight and liver function after PH. The hepatic levels of prealbumin decreased by about 60% after PH and minoxidil inhibited the decrease. In conclusion, the K(ATP) channel opener minoxidil enhanced DNA synthesis after PH without affecting the liver function.

Alanine Transaminase↗
PubMed2005

Serosal invasion in TNM staging of mass-forming intrahepatic cholangiocarcinoma.

BACKGROUND/PURPOSE: The Liver Cancer Study Group of Japan established a tumor-nodule-metastasis (TNM) staging system for mass-forming intrahepatic cholangiocarcinoma, with T determined by tumor number and size and vascular or serosal invasion. Serosal invasion is not considered in the designation established by the International Union Against Cancer. METHODS: Sixty-three patients who underwent hepatic resection for mass-forming intrahepatic cholangiocarcinoma were investigated retrospectively, with the investigation including univariate and multivariate analyses of potential prognostic factors. RESULTS: By log-rank test, tumor size more than 3.0 cm, vascular invasion, lymph node metastasis, intrahepatic metastasis, and involved resection margin, but not serosal invasion, were associated significantly with poor prognosis. Even in patients with serosal invasion, the postoperative outcome was much better in those without than in those with vascular invasion. Multivariate analysis identified vascular invasion, lymph node metastasis, and an involved resection margin as independent prognostic factors. When serosal invasion was excluded from tumor staging, the 5-year survival rates became more clearly stratified: 100% in those with stage I disease, 62% in those with stage II, 25% in those with stage III, and 7% for patients with stage IV. CONCLUSIONS: Serosal invasion showed no survival impact after hepatic resection for mass-forming intrahepatic cholangiocarcinoma. When serosal invasion was omitted from the TNM staging proposed by the Liver Cancer Study Group of Japan, stratification of postoperative survival between stages was more effective.

Adult↗
PubMed2005

Prognostic effects of causative virus in hepatocellular carcinoma according to the Japan integrated staging (JIS) score.

BACKGROUND: The Japan integrated staging (JIS) score is recognized to be useful in managing hepatocellular carcinoma (HCC). We evaluated the effects of the causative virus in patients stratified by this system. METHODS: We compared clinicopathologic features, cumulative and tumor-free survival rates, and causes of death between 301 hepatitis C virus-positive patients (HCV group) and 60 hepatitis B virus-positive patients (HBV group). RESULTS: Among patients with low JIS scores (0 or 1), the proportions of patients with high aspartate and alanine aminotranferase activities, moderate-to-severe active hepatitis, and with cirrhosis were significantly higher in the HCV than in the HBV group. Among patients with high JIS scores (2 to 4), the proportion with moderate-to-severe active hepatitis was also significantly higher in the HCV group. In patients with low JIS scores, those in the HCV group had significantly lower tumor-free and cumulative survival rates than those in the HBV group. Although no patient in the HBV group died of causes other than liver disease (HCC or hepatic failure), some patients in the HCV group died of causes other than liver disease. The proportion of patients who died because of HCC recurrence tended to be higher among patients with high JIS scores than among patients with a low JIS score. CONCLUSIONS: The effects of viral status on survival outcomes are greatest in patients with JIS scores of 0 or 1.

Carcinoma, Hepatocellular↗
PubMed2005

Potentiality of combined hepatocellular and intrahepatic cholangiocellular carcinoma originating from a hepatic precursor cell: Immunohistochemical evidence.

Hypothesizing that combined hepatocellular and intrahepatic cholangiocellular carcinoma originates from hepatic stem cells, we conducted a series of immunohistochemical studies using hepatic stem cell markers to better understand the origin of the tumor. Specially, we investigated 15 combined tumors confirmed to be immunoreactive to anti-hepatocyte paraffin 1, and anti-cytokeratin 7 and 19 antibodies. Macroscopic investigation revealed cancer cells morphologically intermediate between neoplastic hepatocytes and cholangiocytes (combined tumor with intermediate morphology) in 11 of 15 tumors. The remaining four tumors lacking these cells were considered ordinary combined tumors. We used 20 hepatocellular carcinomas and 10 cholangiocarcinomas as controls. Immunohistochemical analysis was performed using stem cell markers (c-kit and CD34). Of the 15 combined tumors, 8 stained for c-kit (2 of the 4 ordinary tumors and 6 of the 11 intermediate morphologic tumors). Both of the tumor cell types in both of the ordinary combined tumors stained for c-kit. The c-kit staining was present in cells of all three morphologic types, including the intermediate cells, in all six of the intermediate combined tumors. None of the cells in the combined tumors showed immunoreactivity for CD34. None of the 30 control tumors expressed CD 34 or c-kit. The present study suggests that combined hepatocellular and intrahepatic cholangiocellular carcinomas originate not from a hepatic stem cell, but from a hepatic precursor cell, such as the canal of Hering cell. Alternatively, these tumors might show up-regulation of c-kit in relation to angiogenesis.

Journal Article↗
PubMed2004

Clinicopathologic characteristics of small intrahepatic cholangiocarcinomas of mass-forming type.

We investigated the clinicopathologic characteristics of and outcome after treatment for small intrahepatic cholangiocarcinomas of mass-forming type (3cm or smaller) in nine patients to study appropriate treatment. In seven of the nine patients, the cancer was detected during follow-up for hepatitis C virus-related disease. One patient was seropositive for anti-hepatitis B core antibody alone. One patient had alcoholic cirrhosis. Three patients also had hepatocellular carcinoma. Seven patients underwent liver resection and two other patients underwent microwave coagulation therapy. In the resection specimens, no vascular or lymphatic invasion, or invasion of perineural spaces, was evident pathologically. No patient had intrahepatic metastasis or lymph node metastasis; all had hepatic fibrosis. Lung metastases developed after surgery in one patient whose surgical margin was positive for cancer. In one patient with both type of carcinoma, the hepatocellular carcinoma recurred. Screening for not only hepatocellular carcinoma but also intrahepatic cholangiocarcinoma is necessary in patients with hepatic fibrosis, especially those infected with hepatitis C virus. For small intrahepatic cholangiocarcinomas of mass-forming type located peripherally in the liver, partial resection or ablation therapy with care to obtain a negative surgical margin may be appropriate.

Journal Article↗
PubMed2004

Surgical strategy for hepatocellular carcinoma originating in the caudate lobe.

BACKGROUND: The prognosis of hepatocellular carcinoma originating in or mainly involving the caudate lobe (caudate HCC) is generally poor. We reviewed the clinicopathologic findings of patients who underwent liver resection of caudate HCC and correlated the outcome with the surgical strategy. METHODS: Records of 402 patients who underwent liver resection for HCC were reviewed. The patients were divided into 2 groups. One group consisted of 15 patients who underwent liver resection for caudate HCC. The other group included 387 patients with HCC in a site other than the caudate lobe. RESULTS: Anatomic resection of Couinaud segment I or IX (a partial caudate lobectomy), conforming to portal anatomy, was performed in 13 patients with caudate HCC, and segmentectomies of segments I and IX (a total caudate lobectomy) were performed in 2 patients with caudate HCC. The incidence of postoperative complications was similar in the caudate HCC group and HCC in other sites group, with no operative deaths in the caudate HCC group. Tumor-free survival and cumulative survival were similar in the 2 groups. However, among patients with caudate HCC, tumor-free and cumulative survival were lower in patients with than without microscopic portal venous involvement (P<.01). CONCLUSIONS: Partial caudate lobectomy (anatomic resection of segment I or IX) along the portal system is an appropriate procedure for caudate HCC, especially in patients with impaired liver function or a small HCC. Patients with caudate HCC who have microscopic portal venous involvement may require adjuvant therapy as early recurrence is likely.

Adult↗
PubMed2004

Hepatitis C virus infection as a likely etiology of intrahepatic cholangiocarcinoma.

Although hepatitis C virus (HCV)-related cirrhosis has been suggested as a risk factor for intrahepatic cholangiocarcinoma (ICC), few sizeable studies have tested this hypothesis. We investigated ICC risk factors, with special reference to HCV infection. We conducted a hospital-based case-control study including 50 ICC patients and 205 other surgical patients without primary liver cancer. HCV seropositivity was detected in 36% of ICC patients and 3% of controls. By univariate analysis, the odds ratio (OR) for association of anti-HCV antibodies with development was 16.87 (95% confidence interval (CI), 5.69 to 50.00). History of blood transfusion or diabetes mellitus, elevated serum total bilirubin, elevated aspartate aminotransferase and alanine aminotransferase, decreased serum albumin and decreased platelet count were identified as other possible ICC risk factors. By multivariate analysis, anti-HCV antibodies (adjusted OR, 6.02; 95% CI, 1.51 to 24.1), elevated alanine aminotransferase, decreased serum albumin, and decreased platelet count were found to be independent risk factors for ICC development. As liver status worsened, the adjusted OR for ICC tended to increase. HCV infection is a likely etiology of ICC in Japan.

Aged↗
PubMed2004

Continuous treatment with organic nitrate affects hepatic cytochrome P450.

We previously reported that cytochrome P450 (P450) is a key enzyme of organic nitrate biotransformation and that P450 levels of the heart and its vessels markedly decreased at the development of nitrate tolerance. Escape from tolerance of organic nitrate by induction of cytochrome P450. Most organic nitrates, including nitroglycerin (NTG), are metabolized in the liver, where nitric oxide (NO) is concomitantly produced from the organic nitrates. Therefore, organic nitrate administration may also affect hepatic P450 levels, since the liver is the major organ of P450-related metabolism. Male Wistar rats were intravenously administrated NTG or isosorbide dinitrate (ISDN) for 24-96 h. Hepatic P450 was drastically decreased after 48 h or 72 h of continuous NTG or ISDN infusion, when nitrate tolerance was observed, but it recovered 48 h after cessation of the drug administration. hemeoxygenase-1 (HO-1) was induced within 24 h of continuous NTG infusion, but it returned to normal levels 48 h after cessation of the NTG. The administration of sodium nitroprusside, an agent to which the animals showed no tolerance, did not induce HO-1 or P450 depletion as judged by SDS-PAGE in combination with Western-blotting. These results suggest that P450-dependent drug metabolism may be drastically affected after continuous organic nitrate administration.

Animals↗
PubMed2003

Continuous administration of organic nitrate decreases hepatic cytochrome P450.

We previously reported that cytochrome P450 (P450) is a key enzyme of organic nitrate biotransformation and that P450 levels of the heart and its vessels markedly decreased at the development of nitrate tolerance. Although our attention was mainly focused on the circulatory organs, most organic nitrates, including nitroglycerin (NTG), are metabolized in the liver, where nitric oxide (NO) is concomitantly produced from the organic nitrates. NO reacts with various molecules such as superoxide, heme, thiols, and oxygen. This paper examined whether hepatic P450 levels are also affected after organic nitrate administration, since the liver is the major organ of P450 related metabolism. Male Wistar rats were intravenously administrated NTG or isosorbide dinitrate (ISDN) for 24-96 h. We observed the level of hemeoxygenase-1 (HO-1) as the functional marker of hepatic P450, since one of the acute phase target proteins of NO induction is an inducible type of HO-1. Hepatic P450 was drastically decreased after 48 or 72 h of continuous NTG or ISDN infusion, when nitrate tolerance was observed, but it recovered 48 h after cessation of the NTG administration. HO-1 was induced within 24 h of continuous NTG infusion, but it returned to normal levels 48 h after cessation of NTG. The administration of sodium nitroprusside, an agent to which the animals showed no tolerance, did not induce HO-1 or P450 depletion. Chronic administration of organic nitrates significantly decreased hepatic P450. These results suggest that P450-dependent drug metabolism may be drastically affected after continuous organic nitrate administration.

Animals↗
PubMed2003

Surgical management of cystic hepatic neoplasms.

BACKGROUND: The clinicopathologic features of cystic neoplasms of the liver, such as cystadenoma and cystadenocarcinoma, are poorly defined because these lesions are extremely rare. METHODS: Clinicopathologic findings in six patients who underwent surgery for a cystic hepatic neoplasm were reviewed retrospectively to determine the best surgical strategy to treat this condition. RESULTS: Five patients had a multilocular cyst or elevated lesions detected on preoperative imaging studies. The remaining patient had elevated serum concentrations of carcinoembryonic antigen and carbohydrate antigen 19-9, even though preoperative imaging studies of the hepatic cystic lesion revealed no imaging features of cystadenocarcinoma. Cytology failed to detect malignant cells in the cyst contents of any patient. One patient underwent palliative resection because pleural dissemination was present, and five patients underwent curative resection. Three patients had cystadenoma diagnosed in the surgical specimen. One patient with cystadenocarcinoma has survived for more than 8 years after a curative resection that was limited to the cyst wall, and another patient died of recurrence 13 months after surgery. CONCLUSIONS: When a cystic neoplasm is suspected of being cystadenocarcinoma, hepatic resection should be considered, because reliable criteria for distinguishing cystadenoma from cystadenocarcinoma clinically do not exist.

Adult↗