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M Sakon

Publications and source records attributed to M Sakon.

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

Pancreatic mass due to chronic pancreatitis: correlation of CT and MR imaging features with pathologic findings.

OBJECTIVE: The purpose of this study was to identify helical CT and MR imaging features of pancreatic masses (focal enlargement) due to chronic pancreatitis and their correlation with pathologic findings. CONCLUSION: When histologic fibrosis is uniformly present through the pancreas in patients with chronic pancreatitis, there is no demarcation of masses due to chronic pancreatitis. When there is a greater degree of histologic fibrosis in the masslike part of the pancreas, the mass is often demarcated from the remaining pancreas, and the enhancement pattern on two-phase helical CT and dynamic gadolinium-enhanced MR imaging mimics that of pancreatic adenocarcinoma.

Adenocarcinoma↗
PubMed2001

Expression of p73 and p63 proteins in pancreatic adenocarcinoma: p73 overexpression is inversely correlated with biological aggressiveness.

The significance of p53, a prominent tumor suppressor gene, and its product in various neoplasms including pancreatic adenocarcinoma has been established. We investigated the expression of two types of homologue of p53, p73 and p63, in pancreatic adenocarcinoma by means of immunohistochemistry. Overexpression of p73 was observed in 45.6% of the cases and this phenomenon was more frequently seen in cystic adenocarcinomas than in ductal carcinomas. Furthermore, p73 overexpression was inversely linked to lymph node metastasis, tumor size, and Ki-67 labeling index. On the other hand, p63 overexpression was observed in 68.2% of the cases, but was not related to any clinicopathological features. No correlation was established between the expression of these proteins and aberrant p53 expression. These results suggest that decreased expression of p73 protein and over-expression of p63 protein may play a role in the development of pancreatic adenocarcinoma.

Adenocarcinoma↗
PubMed2001

Clinical application of quantitative analysis for detection of hematogenous spread of hepatocellular carcinoma by real-time PCR.

In order to detect a hematogenous spread of tumor cells in patients with hepatocellular carcinoma, reverse transcription-polymerase chain reaction assay has been used. In this study, we quantified alpha-fetoprotein (AFP) messenger RNA by real-time PCR approach using LightCyclertrade mark technique. AFP messenger RNA in the blood from 23 hepatocellular carcinoma patients undergoing hepatic resection, 31 healthy volunteers, 10 patients with liver cirrhosis and 5 patients underwent hepatectomy except for hepatocellular carcinoma was quantitated. In the real-time PCR, fluorescence was undetectable in any of the controls. On the contrary, fluorescent signals were detected in 10 out of 39 blood specimens collected from 23 HCC patients. AFP-positive status was significantly associated with the existence of multiple intrahepatic nodules. Out of 8 cases with AFP-positive status, intra- and/or extra-hepatic recurrence has been observed in 3 cases. The quantities of AFP messenger RNA in these 3 cases were relatively high among 8 cases with AFP-positive status. AFP messenger RNA was detectable by newly developed real-time PCR approach with LightCycler and it is suggested that this approach could be applicable in detection of small amounts of tumor cells in the blood of HCC patients.

Biomarkers, Tumor↗
PubMed2001

Human stomach-specific gene, CA11, is down-regulated in gastric cancer.

To reveal the implication in gastric cancer pathogenesis of the novel human gene referred to as CA11, which was recently isolated by a differential display technique using normal gastric mucosa and gastric cancer tissue, we examined CA11 expression in 50 primary gastric cancers and also introduced the CA11 gene into gastric cancer cells. RNA dot blot analysis against various human organs and developmental stages demonstrated that CA11 was intensively expressed especially in normal stomach tissue. Northern blot analysis showed that expression of the CA11 gene in cancer tissue was down-regulated compared with normal tissue. Semi-quantitative RT-PCR also demonstrated that CA11 gene expression was decreased in 41 out of 50 (82%) of the gastric cancer tissues, when compared with normal stomach tissues, while no relationship was found between CA11 expression and various clinicopathological characteristics including histological type, depth of invasion, lymph node metastasis, and clinical stage. Immunohistochemical analysis with anti CA11 antibody showed that CA11-positive staining was observed in the surface regions of normal gastric epithelium, but was found faintly or not at all in cancer tissues. CA11 transfected MKN28 cells also displayed a marked decrease in the number of colony formations when compared to double normal controls. These findings suggest that the loss of CA11 expression in gastric tissues may play an important role in gastric carcinogenesis.

Adenocarcinoma↗
PubMed2001

Localized activation of m-calpain in migrating human umbilical vein endothelial cells stimulated by shear stress.

Using a parallel-plate flow-chamber and confocal laser scanning microscopy (CLSM), we studied the mode of cytoskeletal reorganization in migrating HUVECs stimulated by shear stress. Activation of m-calpain associated with a change in the spatial distribution of cytoplasmic ionized Ca2+ concentration ([Ca2+](i)) was studied. Shear stress (10 dyne/cm(2)) caused migration and decrease in the F-actin content of HUVECs. Migrating individual HUVECs showed the lamellipodium formed in the direction of cell migration, in which [Ca2+](i) elevated to 148 +/- 12 nM in a localized fashion. We found the appearance of activated m-calpain in the local area of the migrating HUVECs, which was associated with a decrease in the amounts of pp125FAK and ezrin. The localized rise in [Ca2+](i) might be closely related to morphological change to regulate the direction of cell migration induced by shear stress through localized activation of m-calpain.

Aniline Compounds↗
PubMed2001

[Significance of liver resection for multiple hepatic metastases from colorectal cancer].

In colorectal cancer, liver metastasis is the most common and most important prognostic factor. To elucidate the significance of liver resection, we examined 72 cases (H2: 29 cases, H3: 43 cases). The 3-year survival rate for H2 and H3 patients was 71.5% and 4.5%, respectively. The liver resection rate in H2 and H3 patients was 58.6% (17/29) and 16.3% (7/43), respectively. In H2 patients the 3-year survival rate of those with liver resection and non-resection was 71.3% and 9.2%, respectively (p < 0.001). However, in H3 patients the 3-year survival rate in liver resection and non-resection patients was 80.0% and 43.9%, respectively (not significant). Many therapies, such as liver resection, hepatic arterial infusion, and systemic chemotherapy, were attempted for patients with hepatic metastases. Our data show that liver resection can prolong the survival of H2 patients only. On the other hand, hepatic arterial infusion therapy prolongs the survival of H3 patients only. Systemic chemotherapy does not prolong the survival of either H2 or H3 patients.

Adult↗
PubMed2001

[A case of postoperative multiple hepatic metastasis from esophageal cancer successfully treated by surgical resection and hepatic arterial infusion chemotherapy].

A 66-year-old male who underwent radical resection for esophageal cancer (stage IV) was diagnosed with multiple hepatic metastasis 1 year and 3 months after the surgery. He underwent hepatic resection and received systemic chemotherapy (FAP: 5-FU, ADR, CDDP), as the post-operative adjuvant therapy. One year and 3 months later, there was a huge recurrence in the residual liver and hepatic arterial infusion chemotherapy (FAP) was performed. The recurrent lesion disappeared completely after 3 sessions of arterial infusion chemotherapy. The arterial infusion chemotherapy was continued in the outpatient clinic and the recurrent lesion is well controlled. At present, this patient has returned to social life, 2 years and 3 months after the hepatic resection. The utility of hepatic arterial infusion chemotherapy and hepatectomy for postoperative multiple hepatic metastasis from esophageal cancer was shown in the present case.

Aged↗
PubMed2001

[A patient with hepatocellular carcinoma and portal vein thrombosis in 1st branch who was treated by transcatheter arterial embolization].

We report a patient with hepatocellular carcinoma (HCC) with portal vein thrombosis in the 1st branch who was treated by transcatheter arterial embolization (TAE) and survived more than 3 years. A 58-year old male was diagnosed as having unresectable massive type HCC in the area of S8 with portal vein thrombosis from the P8 branch to the right portal branch. He was treated by TAE via the anterior branch of right hepatic artery. One week later, localized hepatic infarction in the anterior segment was recognized. Five months later, the portal vein thrombosis had disappeared and become necrotic. After 3 years and 4 months, he died of a relapse of a gastric varix, but with no portal thrombosis and a well controlled intra-hepatic recurrence that was treated by repeated TAE. This case suggests that TAE might be effective for cases of HCC with portal vein thrombosis in the 1st branch, if the liver function and portal flow are suitable.

Carcinoma, Hepatocellular↗
PubMed2000

The inhibitory effect of prostaglandin E1 on oxidative stress-induced hepatocyte injury evaluated by calpain-mu activation.

BACKGROUND: Prostaglandin E1 (PGE1) is known to inhibit ischemia-reperfusion injury of the liver. The calcium-dependent neutral proteinase, calpain-mu, is involved in oxidative stress-induced hepatocyte injury. We investigated the mechanisms of cytoprotection by PGE1, focusing on the elevation of intracellular calcium ([Ca2+]i), activation of calpain-mu, and calpain-mu-mediated activation of protein kinase C-alpha (PKC-alpha). METHODS: Cultured hepatocytes were treated with various amounts of PGE1 (0, 0.1, 1.0, 10, and 100 ng/ml) for 30 min and subsequently with 0.5 mM tert-butyl hydroperoxide (TBHP). Cell injury was evaluated by the release of lactate dehydrogenase. Plasma membrane bleb formation was examined by phase contrast microscopy. Activation of calpain-mu and limited degradation of PKC-alpha was evaluated by Western blotting using antibodies that specifically recognize the amino-terminal regions of calpain-mu and PKC-alpha. [Ca2+]i was measured by confocal microscopy using Fluo-3AM. RESULTS: LDH release from cells treated with 10 ng/ml PGE1 was significantly lower than from untreated cells (135 +/- 12 vs. 258 +/- 18 IU/L, respectively; P < 0.05). Morphologically, many blebs were observed in untreated cells, but very few were seen in those treated with 10 ng/ml PGE1. Western blotting revealed that the amount of activated calpain-mu and [Ca2+]i increased up to 1,300 nM at 35 min after the addition of TBHP (0.5 mmol/L) in control experiments (without PGE1). PGE1 (10 ng/ml) delayed the rise in [Ca2+]i for about 30 min, but did not suppress it completely. PKC-alpha decreased in experiments using PGE1 (10 ng/ml). CONCLUSION: PGE1 exerts its cytoprotective effect in TBHP-induced hepatocyte injury partly by inhibiting Ca2+-calpain-mu-mediated mechanisms.

Alprostadil↗
PubMed2000

Human umbilical vein endothelial cells (HUVECs) show Ca(2+) mobilization as well as Ca(2+) influx upon hypoxia.

Bleb formation is an early event of cellular damage observed in a variety of cell types upon hypoxia. Although we previously found that the [Ca(2+)](i) rise before bleb formation only at the same loci of HUVECs upon hypoxia (localized [Ca(2+)](i) rise), the mode of the [Ca(2+)](i) rise remains ill-defined. In order to clarify the mechanisms causing the localized [Ca(2+)](i) rise in hypoxia challenged HUVECs, we studied the effects of several Ca(2+) channel blockers or a Ca(2+) chelator, EGTA, which reduces extracellular Ca(2+) concentration on the hypoxia-induced localized [Ca(2+)](i) rise and bleb formation by employing a confocal laser scanning microscopy (CLSM). After the initiation of hypoxia, [Ca(2+)](i) rose gradually in a localized fashion up to 15 min, which was associated with bleb formation at the same loci. The maximal [Ca(2+)](i) rise was 435 +/- 84 nM at the loci of bleb formation. Ca(2+) channel blockers including Ni(2+) (non-specific, 1 mM), nifedipine (L type, 10 microM), nicardipine (L + T type, 10 microM), and cilnidipine (L + N type, 10 microM) did not inhibit either the localized [Ca(2+)](i) rise or bleb formation. Although both the localized [Ca(2+)](i) rise and bleb formation were inhibited by lowering extracellular Ca(2+) concentration below 100 nM, a diffuse [Ca(2+)](i) rise through the cytoplasm remained without bleb formation, which was inhibited by a phospholipase C (PLC) inhibitor, U73122. In conclusion, hypoxia causes both the Ca(2+) mobilization and the Ca(2+) influx in HUVECs and the Ca(2+) influx through unknown Ca(2+) channels is responsible for the localized [Ca(2+)](i) rise integral to bleb formation.

Calcium↗
PubMed2000

Induction of unresponsiveness to islet xenograft by MMC treatment of graft and blockage of LFA-1/ICAM-1 pathway.

BACKGROUND: Induction of unresponsiveness to graft is one of major interest in xenotransplantation. Two different modalities [direct graft treatment by mitomycin C (MMC) and blockage of the lymphocyte function-associated antigen-1/intracellular adhesion molecule-1 (LFA-1/ICAM-1) pathway in recipients by species-specific mAbs] were tested for their ability to produce unresponsiveness to secondary islet xenografts. METHODS: Collagenase-digested WS (RT1k) rat islets, purified by Ficoll density gradient, were incubated for 30 min with MMC 10 microg/ml, cultured for 20 hr, and transplanted into the renal subcapsular space of streptozotocin-induced diabetic C57BL/6 (H-2b) mice. Recipient mice were divided into experimental groups according to anti-rat ICAM-1 and/or anti-mouse LFA-1 mAb treatment and transplantation of MMC-treated or nontreated islets. RESULTS: MMC pretreatment alone prolonged graft survival, with a mean survival time (MST) of 23.0+/-7.4 days, compared with that of cultured islets (12.4+/-2.7 days; P<0.01). MMC treatment of islets significantly augmented graft survival, compared with that of crude islet grafts under treatment with anti-donor ICAM-1 mAb (MST: >41.3+/-30 vs. 16.6+/-5.4 days, P<0.01), anti-recipient LFA-mAb (MST: >70.3+/-28.9 vs. 30.4+/-10.4 days, P<0.001), or both mAbs (MST: >88.1+/-24.1 vs. 23+/-7.4 days, P<0.0001). One of six, four of nine, and six of eight animals accepted MMC-treated islet xenografts over 100 days after treatment with anti-rat ICAM-1, anti-mouse LFA-1, or both mAbs treatments, respectively, whereas none of the animals accepted nontreated islets under the same treatment. When the mice bearing long-term functioning xenografts were challenged with the secondary graft from the original donor strain, the animals previously treated with anti-recipient LFA-1 and anti-donor ICAM-1 mAbs were more prone to accept it than animals given anti-recipient LFA-1 mAb alone (MST: 55.8+/-25.7 vs. 15+/-2.4 respectively; P<0.001), although they rejected the third-party xenograft and allograft acutely. CONCLUSIONS: In the xenogeneic islet transplantation model, MMC graft pretreatment and blockage of the ICAM-1/LFA-1 pathway constitute a potent protocol for inducing unresponsiveness to islet xenografts.

Animals↗
PubMed2000

Mammaglobin B gene as a novel marker for lymph node micrometastasis in patients with abdominal cancers.

Mammaglobin B is a recently-isolated gene speculated to belong to the uteroglobin gene family and is overexpressed in primary breast cancers. We investigated mammaglobin B mRNA expression in various cancers of the digestive system. Given the absence of mammaglobin B expression in normal lymph nodes, we also assessed the usefulness of mammaglobin B as a marker for lymph node micrometastases in cancer patients. Mammaglobin B gene transcripts were frequently detected by reverse transcriptase-polymerase chain reaction (RT-PCR) assay in primary tumors of the esophagus (2/3), stomach (7/7), colon (15/15), pancreas (4/6), common bile duct (6/6), cholangioma (2/2) and gall bladder (1/1). Mammaglobin B overexpression was observed in three of 15 cases (20%) of colon cancer, suggesting its possible contribution to colon carcinogenesis. Down-regulated mammaglobin B expression was observed in hepatoma cells in comparison with corresponding non-cancerous livers (3/3). RT-PCR assay of mammaglobin B detected 14 of 15 histologically positive lymph nodes from patients with gastric cancer, colon cancer and cholangioma. Seven of 32 (22%), three of nine (33%), and three of seven (43%) histologically negative nodes from patients with gastric, colon and cholangiocellular carcinoma, respectively, were found to express mammaglobin B mRNA. Our results showed that expression of mammaglobin B was frequently detected in cancers originating in digestive organs, especially adenocarcinomas, and that mammaglobin B gene detected by RT-PCR may be a potentially useful molecular marker for lymph node micrometastases of various digestive organ cancers.

Abdominal Neoplasms↗
PubMed2000

Clinical significance of hepatic resection in hepatocellular carcinoma: analysis by disease-free survival curves.

HYPOTHESIS: The clinical significance of hepatectomy for hepatocellular carcinoma (HCC) is still controversial because of frequent intrahepatic recurrence, which results from either recurrence due to residual intrahepatic metastasis (Rim) or recurrence due to metachronous, multicentric liver carcinogenesis (Rmc). DESIGN: Retrospective review. Disease-free survival curves were obtained by the Kaplan-Meier method and the rates of Rim and Rmc were analyzed using 2 regression lines, based on the evidence that Rmc occurs at a constant rate throughout follow-up, whereas Rim occurs only in the early postoperative period. SETTING: University hospital. PATIENTS: From 1980 to 1996, 241 patients with HCC who underwent curative hepatic resection. MAIN OUTCOME MEASURE: Intrahepatic recurrence. RESULTS: Disease-free survival curves for all patients in the early (within 2 years) and late (4 years after surgery) follow-up were approximated by 2 regression lines, which represent both Rim and Rmc (Y(1) = -3.4X + 48) and only Rmc (Y(2) = -23.1X + 98). Using this approximation, the annual incidence of Rim within 2 years (a(1)-a(2)) was calculated as 19.7% and that of Rmc (a(2)) was 3.4%. The ratio of Rim in tumor recurrence (b(1)-b(2)) was 50%, and that of Rmc (b(1)) was 48%. The ratios of Rmc in patients with stages I and II HCC were 60% and 64%, respectively. In contrast, the values could not be calculated in patients with stages III and IVA because all but 2 patients showed recurrence within 4 years after surgery. CONCLUSION: Tumor recurrence is estimated to result from metachronous liver carcinogenesis in 48% of hepatectomized patients with HCC.

Carcinoma, Hepatocellular↗
PubMed2000

Development of a multiple-marker RT-PCR assay for detection of micrometastases of hepatocellular carcinoma.

We investigated the expression of several candidate gene markers: MAGE-1, MAGE-3, cytokeratin-20 (CK-20), and alpha-fetoprotein (AFP) in tumor tissue and blood specimens from patients with hepatocellular carcinoma to develop a multiple marker reverse transcriptase-polymerase chain reaction (RT-PCR) assay for detection of micrometastasis in circulation. In 24 tumor specimens, the positivity for MAGE-1, MAGE-3, AFP, and CK-20 genes was 71, 67, 88, and 79% respectively, and all specimens expressed at least one marker. Although AFP and CK-20 transcripts were also detected in corresponding noncancerous liver specimens, none of the 22 corresponding normal specimens or seven normal livers were positive for MAGE-1 or MAGE-3 transcripts. In addition, MAGE-1 and MAGE-3 gene transcripts were not detected in any peripheral blood specimens from 31 normal healthy volunteers. MAGE-1, MAGE-3, and AFP transcripts were detected in 9 (12.7%), 3 (4.8%), and 10 (15.9%) of 71 blood specimens from 11 hepatocellular carcinoma patients, respectively, while 19 specimens (26.8%) were positive for at least one marker. Our results indicate that a multimarker RT-PCR assay with cancer-specific markers such as MAGE-1 and MAGE-3 in combination with a liver-specific AFP marker may be a promising diagnostic tool for monitoring hepatocellular carcinoma patients with better sensitivity and specificity.

Blood Physiological Phenomena↗
PubMed2000

Presence of active hepatitis associated with liver cirrhosis is a risk factor for mortality caused by posthepatectomy liver failure.

The histologic activity of associated hepatitis was examined in 285 patients who underwent hepatectomy for hepatocellular carcinoma (HCC), to determine if the histologic activity is an independent risk factor for postoperative mortality due to liver failure. The proportion of patients with liver cirrhosis who died due to liver failure (6/180, 3.3%) was not different from that of patients with chronic hepatitis (2/68, 2.9%). However, mortality was higher in patients with liver cirrhosis and active hepatitis (4/46, 8.7%) than in those with cirrhosis and inactive hepatitis (2/134, 1.5%, P < 0.05). Such difference was not observed in the chronic hepatitis group. Multivariate analysis showed that clearance of indocyanine green at 15 min (ICGR15) and activity of hepatitis were two independent risk factors for postoperative mortality due to liver failure. In conclusion, histologic activity of associated hepatitis should be taken into account in hepatic resection of HCC in cirrhotic liver, in addition to the functional reserve of the liver.

Adult↗