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Dive into the research topics where Masaru Inagaki is active.

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Featured researches published by Masaru Inagaki.


Surgery | 1995

Hepatectomy under extracorporeal circulation

Keisuke Hamazaki; Takahito Yagi; Masaru Inagaki; Noriaki Tanaka; Hisashi Mimura; Kunzo Orita; Nicolas J. Lygidakis

BACKGROUND Resection of hepatic tumors located near the confluence of the hepatic vein or invading the inferior vena cava has become technically feasible and relatively safe by using venovenous bypass. However, some technical problems remain to be solved. METHODS We performed three cases of hepatic resection under extracorporeal circulation combined with hypothermic perfusion. RESULTS An unexpected hemorrhage was observed in all three cases for different causes. The patient of case 2 died of liver failure developed from fatty liver. Bile duct stenosis was observed in cases 1 and 3. CONCLUSIONS Although hepatectomy under total vascular exclusion by use of Biopump is now considered a safe procedure, attention should be paid when this procedure is performed because some technical problems still remain.


European Journal of Gastroenterology & Hepatology | 2002

High-flow-rate haemodiafiltration as a brain-support therapy proceeding to liver transplantation for hyperacute fulminant hepatic failure

Hiroshi Sadamori; Takahito Yagi; Masaru Inagaki; Yasuo Shima; Hiroaki Matsuda; Noriaki Tanaka; Kohsaku Sakaguchi; Takao Tsuji; Masaki Matsumi; Hiroshi Katayama; Norihisa Hirakawa

In fulminant hepatic failure (FHF), rapidly progressive cerebral oedema remains the main fatal complication and an obstacle in liver transplantation. A 29-year-old Japanese woman presented with sudden-onset hepatic encephalopathy and jaundice. Hepatic encephalopathy deteriorated within 2 days of the onset of jaundice. She manifested extensory sustained clonus and was responsive only to pain. Diffuse cerebral oedema was noted on brain computerized tomography (CT) scan. Urgent living-donor liver transplantation (LDLT) at the time of admission was abandoned because of deterioration of neurological status and radiologically evident diffuse cerebral oedema. Instead, a high-flow-rate (7.2-9.0 l/h) haemodiafiltration with a high-performance membrane was commenced, combined with plasma exchange. This treatment regimen resulted in a gradual improvement of hepatic encephalopathy and complete disappearance of cerebral oedema within 7 days. Liver regeneration did not occur during this period, as evident by CT scan volumetry and serological tests. LDLT was subsequently performed using the right liver lobe of the patients brother. Our case suggests that high-flow-rate haemodiafiltration with a high-performance membrane, combined with plasma exchange, could potentially be brain-support therapy for patients with FHF, and may contribute, when combined with liver transplantation, to the improvement of prognosis in hyperacute FHF.


Surgery Today | 2005

Intraductal Oncocytic Papillary Neoplasm of the Pancreas with Celiac Artery Compression Syndrome and a Jejunal Artery Aneurysm: Report of a Case

Yasuo Shima; Takahito Yagi; Masaru Inagaki; Hiroshi Sadamori; Noriaki Tanaka; Tadashi Horimi; Shuji Hamazaki

A 79-year-old woman presented with epigastralgia, and computed tomography showed a 3-cm multiloculated mass with a mural nodule in the head of the pancreas. Arteriography showed stenosis of the celiac artery and a saccular aneurysm, arising from the first jejunal artery. We made a preoperative diagnosis of intraductal papillary adenocarcinoma of the pancreatic head and performed a laparotomy. Transection of the median arcuate ligament failed to restore adequate hepatic blood flow, necessitating construction of celiac vascularization, achieved by a gastroduodenal to jejunal artery anastomosis. After ligation of the jejunal artery aneurysm, we performed a pylorus-preserving pancreaticoduodenectomy. Microscopically, the tumor had papillary intracystic growth, and was lined by plump cells with abundant eosinophilic cytoplasm, consistent with a diagnosis of intraductal oncocytic papillary neoplasm. We discuss this recently recognized entity of papillary neoplasm of the pancreas, and the importance of managing hepatic blood flow during pancreaticoduodenectomy in celiac artery compression syndrome.


European Journal of Gastroenterology & Hepatology | 2001

Successfully resected hepatoblastoma in a young adult with chronic hepatitis B : report of a case

Masaru Inagaki; Takahito Yagi; Naoto Urushihara; Yasuo Shima; Hiroshi Sadamori; Norihisa Takakura; Noriaki Tanaka; Megumi Oda

Hepatoblastoma usually occurs in children, but a few cases have also been reported in adults. We report the unusual case of hepatoblastoma in an 18-year-old adult with chronic hepatitis B. He visited a local hospital with right upper abdominal pain. Abdominal ultrasound showed a large mass in the right lobe of his liver. He was referred to our hospital and admitted for further examination. At admission, liver function tests gave slightly elevated results (aspartate aminotransferase (AST) 103 IU/l, alanine aminotransferase (ALT) 63 IU/l). A test for hepatitis virus revealed that he was a hepatitis B surface antigen (HBsAg) carrier and had experienced seroconversion. His alpha-fetoprotein (AFP) was elevated to 1 548 000 IU/ml. Abdominal ultrasound showed a 109 x 96 x 80-mm mass with mosaic pattern in the right lobe of the liver and right portal vein thrombus. Abdominal computed tomography (CT) demonstrated a large low-density mass occupying the right lobe, with some high-density parts that showed calcification. From these results, we diagnosed hepatoblastoma in a young adult. A right lobectomy was performed. Pathological examination showed a highly differentiated hepatoblastoma. Adjuvant chemotherapy was performed with cisplatin and pirarubicin. The patient has been well and free of recurrence for 12 months, and his AFP level remains almost normal.


Transplantation | 1989

Induction of antiidiotypic antibodies by donor-specific blood transfusions. Establishment of a human-mouse hybridoma secreting the MLR-inhibiting factor

Takenori Kawamura; Kenichi Sakagami; Minoru Haisa; Futoshi Morisaki; Shinji Takasu; Masaru Inagaki; Toshihiko Oiwa; Kunzo Orita

We describe a patient transfused with 200 ml of donor fresh whole blood three times at 2-week intervals. Three weeks after the last transfusion, transplantation and splenectomy were done at the same time. Splenic cells from this DST pretreated patient were fused with murine myeloma cells (X63-Ag8, 653). With DST pretreatment, various clones were developed in vivo, and finally 69 human immunoglobulin-secreting clones were obtained. Modulation of the alloantigen-specific MLR by supernatants from 69 clones showed various degrees of suppression or augmentation. The hybridoma clone 7 and clone 2, which had been secreting IgG antibody for more than 6 months, showed some degree of suppression in the alloantigen-specific MLR (mean suppression = 63%, 46% respectively). According to the result of MLR, clone 7 antibody was directed against recipient lymphocytes and clone 2 antibody was against donor lymphocytes. Immunoprecipitation was carried out by clone 7-IgG and clone 2-IgG. Clone 7-IgG specifically precipitated 1 molecule from the recipient lymphocyte with a molecular weight of 120 KD, similar to the molecular weight range reported for T cell receptors. Clone 2-IgG precipitated a 20 KD molecule from the donor lymphocyte. The data suggest that DST induces antibodies directed against the blood donor alloantigen-specific receptors on the recipients T lymphocytes--and, at the same time, induces antibodies against donor lymphocyte antigens. These antibodies may be essential to prolongation of kidney allograft survival following DST.


Journal of Surgical Research | 1991

Immunosuppressive mechanism of 15-deoxyspergualin on sinusoidal lining cells in swine liver transplantation: Suppression of MHC class II antigens and interleukin-1 production

Shinji Takasu; Kenichi Sakagami; Futoshi Morisaki; Takenori Kawamura; Minoru Haisa; Toshihiko Oiwa; Masaru Inagaki; Hideaki Hasuoka; Kurozumi Y; Kunzo Orita

To elucidate the precise mechanism of action of 15-deoxyspergualin (DSG) in swine liver transplantation, the expression of MHC class II antigens (Ia) on hepatic sinusoidal lining cells (SLC) and their production of interleukin-1 (IL-1) were examined. In our previous study, we isolated sinusoidal endothelial cells (SEC) and Kupffer cells (KC) by enzymatic digestion and centrifugal elutriation, and demonstrated that both SEC and KC present alloantigens effectively and generated IL-1 in response to allogenic or lipopolysaccharide stimulation. Animals were divided into three groups: group 1, nontransplanted normal controls (n = 3); group 2, no immunosuppressive treatment following liver transplantation (n = 5); group 3, DSG (0.8 mg/kg/day) intravenously for 7 days following liver transplantation (n = 5). At 1 week after transplantation, the three liver grafts in groups 2 and 3 were processed for the study of Ia expression and IL-1 production on SEC and KC. The expression of Ia was detected in 21.5 +/- 4.7% of SEC and 24.3 +/- 11.1% of KC in group 1. In group 3, Ia expression was suppressed compared with group 2, being 3.6 +/- 2.8% versus 22.0 +/- 2.8% for SEC (P less than 0.02) and 15.5 +/- 11.3% versus 24.3 +/- 7.1% for KC. IL-1 production by SEC and KC was respectively 11,483 +/- 3311 cpm and 9077 +/- 2161 cpm in group 1. In group 3, IL-1 production was inhibited compared with that in group 2, being 7190 +/- 883 cpm versus 19,297 +/- 5182 cpm for SEC (P less than 0.05) and 16,130 +/- 3769 cpm versus 25,857 +/- 3963 cpm for KC.(ABSTRACT TRUNCATED AT 250 WORDS)


Journal of International Medical Research | 2002

Analysis of host response to hepatectomy by simultaneous measurement of cytokines in the portal vein, caval vein and radial artery.

Yoshihide Kanaoka; Takahito Yagi; Hiroshi Sadamori; Hiroyoshi Matsukawa; Hiroaki Matsuda; Masaru Inagaki; Takashi Ishikawa; Shinya Saito; Hiromi Iwagaki; Noriaki Tanaka

We analysed the host response to hepatectomy by simultaneous measurement of various cytokines and their antagonists in the portal vein, caval vein and radial artery in 10 patients with hepatocellular carcinoma. Concentrations of tumour necrosis factor-α (TNF), interleukin (IL) 1β, IL-2, IL-6, IL-10, soluble TNF receptor type I (sTNF-R), soluble IL-2 receptor (sIL-2R), IL-1 receptor antagonist (IL-1ra), soluble CD14 (sCD14) and endotoxin were determined just before and 1 h after hepatectomy. The values of IL-6, sTNF-R and IL-1ra were significantly increased after hepatectomy at each sampling site. In contrast, the levels of sIL-2R and sCD14 after hepatectomy were significantly decreased, and the levels of IL-1β, IL-2 and IL-10 were below the detection limits. Differences in cytokine concentrations between sampling sites revealed that the surgical stress of hepatectomy induced significant IL-1ra production in the liver and sTNF-R and IL-6 production in the lungs. These results suggest that hepatic resection is followed by the production of cytokine antagonists, such as IL-1ra, sTNF-R and IL-6, which could represent an important regulatory mechanism against surgical stress.


Journal of International Medical Research | 2002

Increased heme oxygenase-1 gene expression in the livers of patients with portal hypertension due to severe hepatic cirrhosis

Masaki Matsumi; Takatoru Takahashi; Hiromi Fujii; I Ohashi; Ryuji Kaku; Hideki Nakatsuka; Hiroko Shimizu; Kiyoshi Morita; Masahisa Hirakawa; Masaru Inagaki; Hiroshi Sadamori; Takahito Yagi; Noriaki Tanaka; Reiko Akagi

Surgical bleeding associated with splanchnic hyperaemia due to portal hypertension complicates the anaesthetic management of hepatic transplantation. Although the mechanism(s) of portal hypertension are not fully understood, carbon monoxide, a product of the heme oxygenase (HO) reaction, is thought to be one of the endogenous vasodilators in the liver. In this study, the expression of mRNA encoding inducible HO isozyme (HO-1) in the livers of patients with portal hypertension undergoing hepatic transplantation was determined in comparison with those without portal hypertension. HO-1 mRNA levels were significantly greater in the portal hypertension group than in the group without portal hypertension. In contrast with HO-1, the gene expression of non-specific δ-aminolevulinate synthase (ALAS-N), which is down-regulated by heme in the liver, was the same in both groups. These results suggest that HO-1 is up-regulated through heme-independent stimuli according to the development of portal hypertension, and that induced HO-1 plays a pathophysiological role in portal hypertension through carbon monoxide production.


Journal of International Medical Research | 2001

Donor Dendritic Cells and Recipient Kupffer Cells in the Induction of Donor-Specific Immune Hyporesponsiveness

K Nakagawa; Tsuyoshi Matsuno; Hiromi Iwagaki; Yoshinori Morimoto; Toshiyoshi Fujiwara; Hiroshi Sadamori; Masaru Inagaki; Naoto Urushihara; Takahito Yagi; Noriaki Tanaka

The aim of this study was to investigate the ability of portovenously administered donor antigens to induce immune hyporesponsiveness. Lewis (LEW, RT-1l) rats received Brown Norway (BN, RT-1n) rat donor splenocytes, via either the portal vein (PV group) or the peripheral vein (IV group). The immune responses of LEW rats, treated with either donor BN or third party Wistar King A (WKA, RT-1k) splenocytes were established by the persistence of donor dendritic cells (DCs) in the host liver measured using fluorescence microscopy and flow cytometry and by the mixed lymphocyte reaction (MLR). The effect of intravenous gadolinium chloride (GDCl3) on the blockade of Kupffer cell function prior to portovenous administration of splenocytes was also assessed. The MLR response was strongly inhibited in a BN-restricted manner after portovenous administration of donor BN splenocytes, but not by venous nor by portovenous administration of WKA splenocytes. Immunosuppression was blocked by pretreatment with GDCl3. The percentage of donor DCs in hepatic non-parenchymal cells (NPCs) was significantly higher in the PV group compared with the IV group. Treatment with GDCl3 decreased the percentage of donor DCs. In addition, cytotoxic T lymphocyte antigen 4 (CTLA4/CD152), which may function as an immune attenuator, was strongly stained, and B7 was weakly stained in recipient liver in the PV group compared with the IV group. These results suggest that both donor DCs and recipient Kupffer cells (self DCs) are involved in the induction of immune hyporesponsiveness by donor cells. This occurs via portovenous administration, in which a signal of the CTLA4–B7 pathway played an important part in inhibiting the interaction of CD28 and its B7 ligands.


Surgical Endoscopy and Other Interventional Techniques | 2003

The analysis of the usefulness of laparoscopic microwave coagulation therapy for hepatocellular carcinoma in patients with poor hepatic reserve by serial measurements of IL-6, cytokine antagonists, and C-reactive protein

Hiroshi Sadamori; Takahito Yagi; Yoshihide Kanaoka; Yoshinori Morimoto; Masaru Inagaki; Takashi Ishikawa; Hiroyoshi Matsukawa; Hiroaki Matsuda; Hiromi Iwagaki; Noriaki Tanaka

Background: Little is known about the effectiveness of laparoscopic microwave coagulation therapy (L-MCT) for hepatocellular carcinoma (HCC) in patients with liver cirrhosis and poor hepatic reserve. Here, we analyzed the usefulness of laparoscopic MCT by comparing the serum levels of IL-6, cytokine antagonists, and C-reactive protein (CRP) following L-MCT with those following MCT with the open method (O-MCT). Methods: Sixteen patients with hepatocellular carcinoma (HCC) were separated into L-MCT and O-MCT groups according to ICGR15 (ICGR15 30%<:L-MCT, 30%> :O-MCT). Nine patients with poorer hepatic reserve received L-MCT, while seven patients with relatively good hepatic reserve received O-MCT. Serum levels of cytokine antagonists (interleukin-6, IL-6; interleukin-1 receptor antagonist, IL-1ra; soluble tumor necrosis factor receptor type I, sTNF-R55) and C-reactive protein (CRP) were simultaneously measured on serial postoperative days (POD) by immunoassay. Results: Postoperative serum levels of IL-6, IL-1ra, and CRP were significantly elevated on POD-1 and returned to the preoperative levels on POD-7 in both L-MCT and O-MCT groups. In contrast, no significant elevation of sTNF-R55 was found during the period in both groups. In addition, no statistical differences were found in the levels of IL-6, IL-1ra, sTNF-R, and CRP between the groups, except that the level of IL-6 on POD-1 in L-MCT group was significantly lower than that in the O-MCT group. Conclusion: These results suggested that the surgical stress by L-MCT in patients with poorer hepatic reserve were almost equal to that by O-MCT in patients with relatively good hepatic reserve, indicating the usefulness of L-MCT for HCC patients with poorer hepatic reserve. We recommend the laparoscopic approach for future patients with the criterion that ICGR15 is over 30%.

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