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Dive into the research topics where Hirotaka Kato is active.

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Featured researches published by Hirotaka Kato.


Transplantation | 1999

Elimination of Kupffer cells and nafamostat mesilate rinse prevent reperfusion injury in liver grafts from agonal non-heart-beating donors.

Shigeki Tsukamoto; Nobuhiro Ohkohchi; Tatsuya Fukumori; Takashi Orii; T Asakura; J Takayama; Hiroshi Shibuya; Hirotaka Kato; Susumu Satomi

BACKGROUND We hypothesized that microcirculatory disturbance was an obstacle to liver transplantation (LTx) from non-heart-beating donors (NHBDs) and that it was attributed mainly to a deterioration of sinusoidal endothelial cells (SECs) and sinusoidal narrowing. This study was designed to examine porcine orthotopic LTx using livers obtained from pretreated agonal NHBDs, and to determine whether the maintenance of the liver microcirculation would result in successful LTx from agonal NHBDs. METHODS Pigs were allocated to five groups: (i) control group; (ii) NM group, in which grafts were rinsed with nafamostat mesilate (NM) rinse; (iii) LD group, in which Kupffer cells in grafts were eliminated by liposome-encapsulated dichloromethylene diphosphonate (L-DMDP); (iv) LDNM group, in which grafts pretreated with L-DMDP were rinsed with NM rinse; (v) heart-beating donor (HBD) group. In all groups, but the HBD group, the livers were pretreated with FK506 and prostaglandin I2 analogue, and were preserved in University of Wisconsin solution after cardiac arrest. Thereafter orthotopic LTx was performed. RESULTS After reperfusion, it was histologically demonstrated that elimination of Kupffer cells prevented SECs deterioration and NM rinse prevented sinusoidal narrowing. The hepatic energy charge recovered in all groups except the control group. In the LDNM group, three of four recipients survived more than 7 days. CONCLUSIONS For a successful LTx from agonal NHBDs, it is important to prevent microcirculatory disturbance caused by SEC deterioration and sinusoidal narrowing after reperfusion. Combination therapy consisting in the elimination of Kupffer cells and NM rinse prevented primary graft non-function in liver grafts from agonal NHBDs.


Journal of Pediatric Surgery | 1997

Liver transplantation for severe hypoxemia caused by patent ductus venosus

Takashi Orii; N Ohkohchi; Hirotaka Kato; Hideyuki Doi; Takuji Hirano; S. Sekiguchi; Yorihiro Akamatsu; Susumu Satomi

The authors describe the case of a 9-year-old girl who underwent liver transplantation because she suffered from severe hypoxemia caused by patent ductus venosus (PDV). Generally, severe hypoxemia (PaO2 < 50 mm Hg in room air or < 300 mm Hg in pure oxygen) is not an indication for liver transplantation because the hypoxemia may not be improved, and may lead to a fatal outcome. PDV, which is associated with mild liver dysfunction, is not an indication for liver transplantation by itself. But in our patient, most of the mesenteric venous flow directly entered the systemic circulation through the PDV just like the portosystemic shunt, and this caused the pulmonary arteriovenous shunt and hypoxemia. Thus, the authors operated on the patient in an attempt to restore her pulmonary function. Nitric oxide (10 to 20 ppm) was added to the inhaled gas to dilate the functional pulmonary capillaries and to deliver sufficient oxygen after the transplantation. Although the patient suffered various complications after the operation, the final results were excellent.


Journal of Pediatric Surgery | 1990

Immunocytochemical characterization of supporting cells in the enteric nervous system in Hirschsprung's disease

Hirotaka Kato; Teiji Yamamoto; Hirotaka Yamamoto; Ryoji Ohi; Naobumi So; Yuzo Iwasaki

The enteric nervous system (ENS) is composed of two distinct neural components, extrinsic and intrinsic, and its supporting cells uniquely possess some characteristics of both central nervous system (CNS) astrocytes and peripheral nervous system (PNS) Schwann cells. To provide further insight into the neural defects in Hirschsprungs disease, the supporting cells in biopsied normal gut, ganglionic, and aganglionic segments from six cases of Hirschsprungs disease were investigated immunocytochemically for localization of three neuroglial markers, glial fibrillary acidic protein (GFAP), S-100 protein, and glutamine synthetase (GS), by the avidin-biotin-horseradish peroxidase complex method applied to free-floating thick cryostat sections. In normal control gut and ganglionic segments of Hirschsprungs colon, all of the GFAP, S-100, and GS were expressed strongly by the supporting cells of the myenteric and submucosal plexuses, interconnecting nerve fiber bundles of the plexuses, and fine nerve strands in the muscular layer. The nerve bundles of the subserosa merging into the muscular layer were also immunoreactive for GFAP and S-100, but negative or only faintly positive for GS. On the other hand, aberrantly proliferated nerve bundles in the aganglionic segment of the Hirschsprungs colon were accompanied by supporting cells strongly positive for GFAP and S-100, but negative or faintly positive for GS. These results indicate that the supporting cells of the enteric neurons proper, enteric glia, express GFAP, S-100, and GS, whereas the supporting cells of the extrinsic components, which accompany PNS axons, are negative or very weakly positive for GS. Thus, GS immunocytochemistry may delineate intrinsic and extrinsic neural components in the ENS, and may provide an important clue for differential diagnosis of Hirschsprungs disease.


Hepatology Research | 2012

Combined hepatocellular carcinoma and neuroendocrine carcinoma with sarcomatous change of the liver after transarterial chemoembolization.

Chikashi Nakanishi; Koichiro Sato; Yasushi Ito; Takayuki Abe; Tetsuya Akada; Ryo Muto; Keita Sakashita; Takuro Konno; Hirotaka Kato; Susumu Satomi

Primary hepatic neuroendocrine carcinoma is rare and its origin is not clearly understood. An admixture of hepatocellular carcinoma (HCC) and neuroendocrine carcinoma is particularly rare. Here, we report a patient with an extremely rare combination of HCC and neuroendocrine carcinoma of the liver. To our knowledge, this is the first reported case in which the carcinoma showed sarcomatous change. The patient was a 76‐year‐old man who had received outpatient treatment for chronic hepatitis C. On abdominal computed tomography (CT), the hepatic tumor was enhanced in the arterial phase but its density was lower than that of normal liver in the portal phases. His serum α‐fetoprotein (AFP) level was very high. Therefore, transarterial chemoembolization (TACE) was performed based on the diagnosis of HCC. Ten months after TACE, his serum AFP level had increased to the level measured before TACE. Partial hepatectomy was performed because CT revealed poor enhancement of the recurrent tumor. Histopathologically, the tumor consisted of two distinct components: moderately differentiated HCC was intermingled with a neuroendocrine carcinoma, which was accompanied by sarcomatous changes. Immunohistochemically, the neuroendocrine carcinoma cells were positive for CD56, chromogranin A and neuron‐specific enolase, and negative for AFP. The sarcomatous area was positive for AE1/3 and CD56, consistent with sarcomatous change of neuroendocrine carcinoma. The neuroendocrine carcinoma and/or sarcomatous change may have been due to phenotypic changes and/or dedifferentiation of HCC induced by TACE. Six months after surgery, the patient was diagnosed with metastasis of the neuroendocrine carcinoma to sacral bone. He died 7 months after surgery.


Transplantation Proceedings | 1997

Elimination of kupffer cells and administration of protease inhibitor improve graft viability and prevent reperfusion injury In NHBD

Shigeki Tsukamoto; N Ohkohchi; Takashi Orii; Tatsuya Fukumori; T Asakura; J Takayama; Hirotaka Kato; Susumu Satomi

T HE SHORTAGE of donors has become a serious problem in liver transplantation (LTX). IF the liver graft from a non-heartbeating donor (NHBD) was available for LTX, the supply could be improved. But a liver graft from NHBD has not been suitable for LTX because the graft viability is deteriorated by warm ischemic injury and severe reperfusion injury. Over the past few years a considerable number of studies has been done on the mechanisms of warm ischemic injury and reperfusion injury. Many agents effective for these injuries, have also been reported. The aim of this study is to determine whether liver grafts from NHBD are suitable for clinical LTX.


International Journal of Surgery Case Reports | 2018

A gastrointestinal stromal tumor of the jejunum presenting with an intratumoral abscess: A case report and a literature review

Soichi Ito; Yuma Tsuchitani; Yuro Kim; Souhei Hashimoto; Yuichi Miura; Takuji Uemura; Kazunori Katsura; Takayuki Abe; Koichiro Sato; Hirotaka Kato

Highlights • An abscess with a thick and vascularized wall suggests an intratumoral abscess.• GISTs developing into intratumoral abscesses are extremely rare.• These GISTs often accompany tumor perforation and peritonitis.• Careful handling is eligible in surgery for these GISTs.• Administration of Imatinib mesylate should be considered for these GISTs.


International Journal of Surgery Case Reports | 2017

Antegrade jejunogastric intussusception and common bile duct stones at 14 months after gastrectomy and cholecystectomy: A case report

Yuichi Miura; Takuji Uemura; Koichiro Sato; Takayuki Abe; Tetsuya Akada; Soichi Ito; Hiroki Yamana; Hirotaka Kato

Highlights • Jejunogastric intussusception occurred after distal gastrectomy followed by Roux-en Y reconstruction.• Common bile duct stone occurred after prophylactic cholecystectomy and distal gastrectomy.• Intussusception and common bile duct stone both could occur simultaneously after gastrectomy.


Transplantation Proceedings | 1998

Graft weight/recipient body weight ratio (G/R ratio) in living-related liver transplantation for pediatric patients : Abdominal wall closure in cases with a large G/R ratio

K Oikawa; N Ohkohchi; Hirotaka Kato; Takashi Orii; Satoru Shimaoka; Naoki Kawagishi; T Asakura; J Takayama; Susumu Satomi


Transplantation Proceedings | 1997

Long-term fasting of donors deteriorates mitochondrial adenosine triphosphate synthesis in liver grafts during cold preservation

Tatsuya Fukumori; N Ohkohchi; Shigeki Tsukamoto; T Asakura; Kosei Oikawa; J Takayama; Takashi Orii; Hirotaka Kato; Susumu Satomi


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2017

A Case of Portal Annular Pancreas Discovered during Pancreaticoduodenectomy

Soichi Ito; Yuichi Miura; Takuji Uemura; Takayuki Abe; Koichiro Sato; Hirotaka Kato

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