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Dive into the research topics where Motohiro Mihara is active.

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Featured researches published by Motohiro Mihara.


Journal of The American College of Surgeons | 2000

Survival and recurrence after hepatic resection of 386 consecutive patients with hepatocellular carcinoma.

Kazuhiro Hanazaki; Shoji Kajikawa; Nobuhiko Shimozawa; Motohiro Mihara; Ko Shimada; Manabu Hiraguri; Naohiko Koide; Wataru Adachi; Jun Amano

BACKGROUND Although hepatic resection is one of the most effective treatments for hepatocellular carcinoma (HCC), the longterm results of hepatic resection of this malignancy are far from satisfactory. The potential benefits of hepatectomy for patients with HCC have not been fully delineated. This study aimed to identify surgical outcomes of 386 consecutive patients with HCC undergoing hepatic resection. STUDY DESIGN The retrospective study looked at records of 293 men and 93 women. The mean age was 63.2 years. Preoperative transarterial chemoembolizaton and portal vein embolization were performed in 138 patients (35.8%) and 8 patients (2.1%), respectively. Sixty-two patients (16.1 %) had major hepatectomy and the other 324 (83.9%) had minor hepatectomy. Thirty-seven of 386 patients (9.6%) had a noncurative operation. RESULTS The 30-day (operative) mortality rate was 4.1%, and there were 11 additional late deaths (2.9%). Two hundred fourteen of 327 patients (65.4%) had recurrence after curative resection. Unfavorable factors for survival and recurrence were resection between 1983 and 1990, Child class B or C, cirrhosis, a high value of indocyanine green retention-15, a large amount of intraoperative blood loss, stage IV disease, positive surgical margin, vascular invasion, and postoperative complications. Preoperative transarterial chemoembolization increased the recurrence rate and showed no contribution to prognosis. Currently, 106 patients (27.5%) are alive: 7 (1.8%) after more than 10 years and 43 (11.1%) after more than 5 years. Mean and median overall survivals after operation were 38 months and 29 months, respectively. The 5-year and 10-year overall or disease-free survival rates after hepatic resection were 34.4% and 10.5% or 23.3% and 7.8%, respectively. CONCLUSIONS The longterm survival rate after operation remains unsatisfactory mainly because of the high recurrence rate. Preoperative transarterial chemoembolization should be avoided because of a high risk of postoperative recurrence. Treatment strategies for recurrent HCC may play an important role in achieving better prognosis after operation, especially in patients with more than Child class B, cirrhosis, high values of indocyanine green retention-15, massive intraoperative blood loss, stage IV disease, positive surgical margin, vascular invasion, and postoperative complications.


Journal of Gastroenterology | 2006

Predictive factors for intrahepatic cholangiocarcinoma recurrence in the liver following surgery

Shiro Miwa; Shinichi Miyagawa; Akira Kobayashi; Yasuhiko Akahane; Takenari Nakata; Motohiro Mihara; Kei Kusama; Junpei Soeda; Shinichiro Ogawa

BackgroundWe performed hepatectomy without lymph node (LN) dissection for intrahepatic cholangiocarcinoma (ICC) limited to the peripheral region of the liver, and hepatectomy with extrahepatic bile duct resection and regional LN dissection for any types of ICC extending to the hepatic hilum. Surgical outcomes were evaluated to elucidate the prognostic factors that influence patient survival with respect to intrahepatic recurrence.MethodsForty-one patients underwent resection of ICC with no macroscopic evidence of residual cancer.ResultsSignificant risk factors for poorer survival included preoperative jaundice (P = 0.0115), serum CA19-9 levels >37 U/ml (P = 0.0089), tumor diameter >4.5 cm (P = 0.017), ICC extending to the hepatic hilum (P = 0.0065), mass-forming with periductal-infiltrating type (P = 0.003), poorly differentiated adenocarcinoma, portal vein involvement (P = 0.0785), LN metastasis at initial hepatectomy (P < 0.0001), and positive surgical margin (P = 0.023). Intrahepatic recurrence, which was the predominant manner of recurrence, was detected in 20 patients (74.1%). Patients with intrahepatic recurrence had a significantly high incidence of high serum CA19-9 levels (>37 U/ml; P = 0.0006), preoperative jaundice (P = 0.0262), ICC extended to the hepatic hilum (P = 0.0349), large tumors (>4.5 cm; P = 0.0351), portal vein involvement (P = 0.0423), and LN metastasis at initial hepatectomy (P = 0.009) compared with disease-free patients. The multiple logistic regression analysis revealed that preoperative CA19-9 elevation and obstructive jaundice influenced intrahepatic recurrence of ICC.ConclusionsAlthough LN metastasis is a significant prognostic factor, the most obvious recurrence pattern after surgery was intrahepatic recurrence, which could be predicted preoperatively by a combination of elevated serum CA19-9 levels and manifestation of obstructive jaundice.


International Journal of Cancer | 1998

p73, a geme related to p53, is not mutated in esophageal carcinomas

Yoshinori Nimura; Motohiro Mihara; Shingo Ichimiya; Shigeru Sakiyama; Naohiko Seki; Miki Ohira; Nobuo Nomura; Minoru Fujimori; Wataru Adachi; Jun Amano; Ming He; Yu-Min Ping; Akira Nakagawara

A novel gene, termed p73, encodes a protein with a significant homology to p53 and has been mapped at chromosome 1p36.3, which is a locus of multiple suppressor genes for tumors including neuroblastoma and other cancers. Since the 1p36 locus is reported to be deleted and p53 is frequently mutated in esophageal carcinomas, we examined loss of heterozygosity (LOH) and mutation of the p73 gene in 48 untreated esophageal tumors, as well as mRNA expression in 8 tumors. We screened the P1 genomic library to obtain a P1 clone containing the p73 gene and found a polymorphic short tandem CT repeat site at intron 9. Intragenic sequences for 14 PCR primer sets and a primer pair flanking the repeat were also determined for the analysis of PCR single‐strand conformation polymorphism (SSCP) and LOH studies, respectively. Expression of p73 mRNA was detectable but at low levels in all 8 tumor tissues by reverse transcriptase PCR. We did not find any type of mutation other than polymorphisms in the 48 esophageal carcinomas, though aberration of the p53 gene on the PCR‐SSCP gels was observed in 15 of 38 (39%) tumors of the same set. In addition, LOH for p73 was found in only 2 of 25 (8%) tumors. These results suggest that, at least in esophageal carcinomas, allelic loss or mutation of p73 may not be a main genetic event for the tumorigenesis as it is with p53. Int. J. Cancer 78:437–440, 1998.


Oncogene | 2000

Identification and characterization of a 500-kb homozygously deleted region at 1p36.2-p36.3 in a neuroblastoma cell line

Miki Ohira; Hajime Kageyama; Motohiro Mihara; Shigeyuki Furuta; Taiichi Machida; Tomotane Shishikura; Hajime Takayasu; Ashraful Islam; Yohko Nakamura; Masato Takahashi; Nobumoto Tomioka; Shigeru Sakiyama; Yasuhiko Kaneko; Atsushi Toyoda; Masahira Hattori; Yoshiyuki Sakaki; Misao Ohki; Akira Horii; Eiichi Soeda; Johji Inazawa; Naohiko Seki; Hidekazu Kuma; Iwao Nozawa; Akira Nakagawara

Loss of heterozygosity of the distal region of chromosome 1p where tumor suppressor gene(s) might harbor is frequently observed in many human cancers including neuroblastoma (NBL) with MYCN amplification and poor prognosis. We have identified for the first time a homozygously deleted region at the marker D1S244 within the smallest region of overlap at 1p36.2-p36.3 in two NBL cell lines, NB-1 and NB-C201 (MASS-NB-SCH1), although our genotyping has suggested the possibility that both lines are derived from the same origin. The 800-kb PAC contig covering the entire region of homozygous deletion was made and partially sequenced (about 60%). The estimated length of the deleted region was 500 kb. We have, thus far, identified six genes within the region which include three known genes (DFF45, PGD, and CORT) as well as three other genes which have been reported during processing our present project for the last 3½ years (HDNB1/UFD2, KIAA0591F/KIF1B-β, and PEX14). They include the genes related to apoptosis, glucose metabolism, ubiquitin-proteasome pathway, a neuronal microtubule-associated motor molecule and biogenesis of peroxisome. At least three genes (HDNB1/UFD2, KIAA0591F/KIF1B-β, and PEX14) were differentially expressed at high levels in favorable and at low levels in unfavorable subsets of primary neuroblastoma. Since the 1p distal region is reported to be imprinted, those differentially expressed genes could be the new members of the candidate NBL suppressor, although RT-PCR-SSCP analysis has demonstrated infrequent mutation of the genes so far identified. Full-sequencing and gene prediction for the region of homozygous deletion would elucidate more detailed structure of this region and might lead to discovery of additional candidate genes.


Carcinogenesis | 2008

Bone marrow-derived cells fuse with hepatic oval cells but are not involved in hepatic tumorigenesis in the choline-deficient ethionine-supplemented diet rat model

Koji Kubota; Junpei Soeda; Ryousuke Misawa; Motohiro Mihara; Shiro Miwa; Hirohiko Ise; Masafumi Takahashi; Shinichi Miyagawa

Bone marrow cells (BMCs) have been reported to behave as tissue-specific stem cells in some organs and to participate in tumorigenesis. However, the roles of BMCs in hepatic regeneration and carcinogenesis are still unknown. A choline-deficient, ethionine-supplemented (CDE) diet leads to the appearance of oval cells, a type of hepatic progenitor cell, and activates their replication. Furthermore, this type of diet induces preneoplastic nodules and hepatocellular carcinomas (HCCs) derived from oval cell progenitors. The aims of this study were to determine whether oval cells are derived from BMCs and whether preneoplastic nodules or HCCs originate from BMCs in the CDE diet rat model. To clarify the origin of constituent cells in the liver, we transplanted BMCs from green fluorescent protein (GFP) transgenic female rats into male Lewis rats, which were then exposed to a CDE diet to induce hepatocarcinogenesis. Some oval cells showed both donor-derived GFP expression and the recipient-specific Y chromosome, indicating that donor BMCs fused with recipient oval cells. Several preneoplastic nodules (precancerous lesions) identified by their glutathione S-transferase placental (GSTp) positivity were induced by CDE treatment. However, these preneoplastic GSTp-positive nodules were not GFP positive. In conclusion, this study has produced two major findings. First, BMCs fuse with some oval cells. Second, BMC-fused oval cells and BMCs might not have malignant potential in the CDE-treated rat model.


Japanese Journal of Cancer Research | 2000

Allelic loss of the region of chromosome 1p35-pter is associated with progression of human gastric carcinoma.

Jun Igarashi; Yoshinori Nimura; Minoru Fujimori; Motohiro Mihara; Wataru Adachi; Hajime Kageyama; Akira Nakagawara

In order to identify the region on distal chromosome 1p that is thought to include one or more tumor suppressor genes for gastric carcinoma, 39 gastric carcinomas were examined for allelic loss using 11 polymorphic microsatellite markers and 1 marker of single strand conformation polymorphism. Loss of heterozygosity (LOH) was found in 18 (46%) of 39 informative patients. The regions with high frequency of loss of heterozygosity were the loci at D1S548 (6/17; 35.3%) and D1S2843 (7/20; 35%), and we found three commonly deleted regions on chromosome 1p35‐pter. The frequency of allelic loss in the region of chromosome 1p35‐pter was significantly associated with advanced‐stage gastric carcinoma, but not with early‐stage tumor or with the histology. These results suggest that allelic loss at chromosome 1p35‐pter may play a role in the progression of gastric carcinoma.


Transplantation | 2004

Domino Liver Transplantation In Living Donors

Yasuhiko Hashikura; Toshihiko Ikegami; Y. Nakazawa; Koichi Urata; Motohiro Mihara; Atsuyoshi Mita; Shinichi Miyagawa

Domino liver transplantation (DLT) has been developed as a method to expand the donor pool. In living donors DLT, the prime concern is to avoid any disadvantage to the donor and the first recipient. Seven DLTs were performed among 211 patients who underwent living donor liver transplantation. The domino recipients included six with hepatocellular carcinoma and one with citrullinemia. The domino grafts were obtained from patients with familial amyloid polyneuropathy (FAP) including the left liver in three cases and the right liver in four. Among the seven domino recipients, a 64-year-old woman with advanced hepatocellular carcinoma died of lung metastasis. The other six domino recipients are alive without FAP symptoms. In living donor liver transplantation, because the vessels of the graft from the first donor are not long enough for anastomosis, the hepatic vessels must be left as long as possible when removing the liver from the FAP patients in order to ensure sufficient safety for vascular reconstruction. With careful decision making during the procedure, such as where to divide the vessels in the FAP patients, DLT may help address the shortage of liver grafts.


Medical and Pediatric Oncology | 2000

Identification of the homozygously deleted region at chromosome 1p36.2 in human neuroblastoma

Akira Nakagawara; Miki Ohira; Hajime Kageyama; Motohiro Mihara; Shigeyuki Furuta; Taiichi Machida; Hajime Takayasu; Ashraful Islam; Yohko Nakamura; Masato Takahashi; Tomotane Shishikura; Yasuhiko Kaneko; Atsushi Toyoda; Masahira Hattori; Yoshiyuki Sakaki; Misao Ohki; Akira Horii; Eiichi Soeda; Johji Inazawa; Naohiko Seki; Hidekazu Kuma; Iwao Nozawa; Shigeru Sakiyama

BACKGROUND We have identified for the first time a homozygously deleted region within the smallest region of overlap at 1p36.2-3 in two neuroblastoma cell lines. PROCEDURE The 800-kb PAC contig covering the entire homozygously deleted region was made and sequenced. To date, approximately 70% of sequencing has been accomplished, and the estimated length of the deleted region was 500 kb. RESULTS Currently, we have found six genes within the region, which include three known genes as well as three other genes that have been reported during processing of our present project for the last 3(1/2) years. We report here the results of expression and mutation analyses of those genes. CONCLUSIONS Full sequencing for the region of homozygous deletion as well as further analyses of the genes mapped within the region may reveal whether or not there is a neuroblastoma suppressor gene as proposed by the Knudsons two-hit hypothesis.


American Journal of Surgery | 2002

A 15-year retrospective study of hepatic resection for stage IV-A hepatocellular carcinoma shows value in hepatitis B negative patients

Kazuhiro Hanazaki; Shoji Kajikawa; Nobuhiko Shimozawa; Motohiro Mihara; Ko Shimada; Manabu Hiraguri; Naohiko Koide; Wataru Adachi; Jun Amano

BACKGROUND The aim of this study is to identify the risk factors of survival and recurrence after curative hepatic resection for stage IV-A hepatocellular carcinoma (HCC). METHODS Sixty-five patients with stage IV-A HCC who underwent curative hepatic resection and discharged from hospital were enrolled in this retrospective study. Prognostic factors were evaluated by univariate and multivariate analysis. Clinicopathologic features and survival with stage IV-A HCC were compared with those of 290 patients with stage I to III HCC who underwent curative hepatic resection during the same period. RESULTS Disease-free and overall survival for patients with stage IV-A HCC was significantly lower than for those with stage I to III HCC. Positive hepatitis B virus (HBV) surface antigen was an independent prognostic factor of poor disease-free and overall survivals in patients with stage IV-A HCC. There were no significant differences in the disease-free and overall survivals between non-HBV-related stage IV-A HCC and stage I to III HCC. CONCLUSIONS Even for patients with highly advanced HCC, curative hepatic resection may be a feasible therapeutic option for those with non-HBV-related HCC.


International Journal of Surgery Case Reports | 2017

A left thoracic approach in a prone position for thoracoscopic thoracic duct ligation in a patient with post-esophagectomy chylothorax: A case report

Kiyotomi Maruyama; Kou Shimada; Toshikazu Hamanaka; Shinsuke Sugenoya; Kuniyuki Gomi; Motohiro Mihara; Shoji Kajikawa; Yusuke Sato

Highlights • Early surgical treatment is recommended for chylothorax after esophagectomy.• We performed thoracic duct ligation in the left thorax in a prone position.• Fine and sharp clips crashed the thoracic duct.• In a prone position, surgeons can easily convert from a left to a right approach.• In a prone position, manual compression of lung is not necessary.• In a prone position, the leakage point is easily found as the fluid trickling.

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