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Dive into the research topics where Masayuki Obatake is active.

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Featured researches published by Masayuki Obatake.


Pediatric Surgery International | 2006

Congenital intrathoracic kidney with right Bochdalek defect

Masayuki Obatake; Tetsuo Nakata; Masahito Nomura; Atsushi Nanashima; Yukio Inamura; Kenji Tanaka; Takeshi Nagayasu

Intrathoracic kidney is a rare congenital anomaly. Since most reported cases are asymptomatic, it is extremely rare for this ectopia to be diagnosed in the neonatal period. We report a male infant with right intrathoracic kidney associated with Bochdalek defect. Chest X-ray demonstrated a right posterior mediastinal mass and intestinal gas in the right lung field. Contrast-enhanced CT and intravenous urography led to a diagnosis of intrathoracic kidney. Due to the presence of Bochdalek defect, the intrathoracic kidney was reduced into the abdominal cavity at the time of diaphragmatic repair. The intrathoracic kidney with attached adrenal gland was located at the level of the carina and was covered with protruded retroperitoneum. The kidney was thought to have been pushed this high by the small intestine and left lobe of the liver, which had also herniated through the defect. Postoperative hemodynamics and renal function were normal.


Annals of Transplantation | 2012

The usefulness of a high-speed 3D-image analysis system in pediatric living donor liver transplantation

Kyoko Mochizuki; Mitsuhisa Takatsuki; Akihiko Soyama; Masaaki Hidaka; Masayuki Obatake; Susumu Eguchi

BACKGROUND Since March 2010, we have used a high-speed 3D-image analysis system (SYNAPSE VINCENT) to calculate the graft volume in living donor liver transplantation (LDLT) to replace CT volumetry. The SYNAPSE VINCENT is capable of extracting each vessel territory in the liver and displaying 3D images simply, quickly, and accurately. Therefore, we report here the usefulness of the SYNAPSE VINCENT in pediatric LDLTs in overcoming issues with perfusion area of hepatic venous tributaries in monosegmental grafts. MATERIAL/METHODS The SYNAPSE VINCENT was used in three pediatric patients. In two of these cases, the possibility of monosegmental grafts was assessed when calculating graft volumetry of segment III. RESULTS The graft recipient weight ratio (GRWR) with graft volumetry measurements of the left lateral segment were 1.8-5.6%. GRWR of segment III were 2.3 and 2.0%. Since donor V2, venous branch to segment II and V3, venous branch to segment III were independently branching in one case, the monosegmental graft could be evaluated preoperatively according to the venous perfusion. CONCLUSIONS Graft volumetry using the SYNAPSE VINCENT was useful for planning the LDLT operative procedures, especially in infants possibly in need of monosegmental graft.


Hpb | 2006

Postoperative changes in protein-induced vitamin K absence or antagonist II levels after hepatectomy in patients with hepatocellular carcinoma: relationship to prognosis

Atsushi Nanashima; Yorihisa Sumida; Syuuichi Tobinaga; Kenichirou Shibata; Hisakazu Shindo; Masayuki Obatake; Shinichi Shibasaki; Noboru Ide; Takeshi Nagayasu

BACKGROUND alpha-Fetoprotein (AFP) has been used as a marker for hepatocellular carcinoma (HCC). However, AFP levels are often high in patients with chronic hepatitis or cirrhosis. Protein-induced vitamin K absence or antagonist II (PIVKA-II) is more sensitive for the diagnosis of HCC and prediction of patient survival. Changes in these markers after treatment may reflect treatment curability and patient outcome. METHODS We conducted a retrospective analysis of prognosis of 63 HCC patients with high preoperative levels of AFP and PIVKA-II who underwent hepatectomy and examined the relationship between postoperative changes in both markers at 1 month and patient survival. Subjects were divided into three groups according to changes in these tumour markers after hepatectomy: normalization (N) group, decreased but still above the normal level (D) group and unchanged (U) group. RESULTS There were no significant differences in the numbers of patients who developed tumour recurrence between changes in AFP and PIVKA-II. Survival analysis showed no significant differences in tumour-free and overall survivals between groups with respect to AFP level. The PIVKA-II-N group showed significantly better tumour-free and overall survival compared with the D and U groups (p<0.01). Multivariate analysis that included other prognostic factors identified changes in PIVKA-II level as a significant and independent prognostic factor associated with overall survival. DISCUSSION Although changes in AFP did not correlate with patient prognosis, normalization of PIVKA-II was significantly associated with good patient survival after hepatectomy. Normalization of PIVKA-II after hepatectomy reflected the efficacy of treatment and is a suitable predictor of prognosis in HCC patients.


Pediatrics International | 2011

Urinary sulfated bile acid analysis for the early detection of biliary atresia in infants

Mitsuyoshi Suzuki; Toshihiro Muraji; Masayuki Obatake; Masaki Nio; Kiichi Ito; Ken Suzuki; Kunitaka Ota; Shunichi Maisawa; Yuichiro Yamashiro; Toshiaki Shimizu

Background:  Measurement of urinary sulfated bile acid (USBA) is a non‐invasive method to detect bile congestion. Our aim was to evaluate the feasibility of USBA analysis for the early detection of biliary atresia (BA).


Pediatric Surgery International | 2012

Partial internal biliary diversion for patients with progressive familial intrahepatic cholestasis type 1

Kyoko Mochizuki; Masayuki Obatake; Mitsuhisa Takatsuki; Akiko Nakatomi; Tomayoshi Hayashi; Sadayuki Okudaira; Susumu Eguchi

We herein report a case of progressive familial intrahepatic cholestasis with partial internal biliary diversion (PIBD). Although by using PIBD an external stoma can be avoided, exposure of the ileocecal junction to bile reflux as well as the effects of the direct bile flow on the colonic mucosa require further investigation.


Pediatric Surgery International | 2012

A modified Foker’s technique for long gap esophageal atresia

Kyoko Mochizuki; Masayuki Obatake; Yasuaki Taura; Yukio Inamura; Ayaka Kinoshita; Akiko Fukuda; Taiichiro Kosaka; Mitsuhisa Takatsuki; Takeshi Nagayasu; Susumu Eguchi

External traction using the Foker’s technique enables elongation in the esophageal segments within days, and allows the primary repair of the long gap. This article presents our modified Foker’s technique which was easily applicable for long-gap esophageal atresia.


Pediatric Surgery International | 2012

Yolk sac tumor of the vulva: a case report with recurrence after long-term follow-up

Kyoko Mochizuki; Masayuki Obatake; Yasuaki Taura; Yukio Inamura; Mitsuhisa Takatsuki; Takeshi Nagayasu; Susumu Eguchi

A yolk sac tumor (YST) of the vulva is extremely rare and highly malignant with recurrence frequently occurring within a year. This report presents the 13th known case of vulvar YST, with recurrence occurring after the longest known follow-up period so far reported in the literature.


American Journal of Medical Genetics Part A | 2005

Klippel-Feil anomaly in a boy and Dubowitz syndrome with vertebral fusion in his brother: A new variant of Dubowitz syndrome?

Shoko Takahira; Tatsuro Kondoh; Muneichiro Sumi; Masato Tagawa; Masayuki Obatake; Eiichi Kinoshita; Osamu Shimokawa; Naoki Harada; Noriko Miyake; Naomichi Matsumoto; Hiroyuki Moriuchi

Shoko Takahira, Tatsuro Kondoh,* Muneichiro Sumi, Masato Tagawa, Masayuki Obatake, Eiichi Kinoshita, Osamu Shimokawa, Naoki Harada, Noriko Miyake, Naomichi Matsumoto, and Hiroyuki Moriuchi Department of Pediatrics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan Department of Pediatric Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan Kyushu Medical Science Nagasaki Laboratory, Nagasaki, Japan Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan


Case Reports in Medicine | 2011

Prophylactic Ligation of the Innominate Artery and Creation of Tracheostomy in a Neurologically Impaired Girl: A Case Report

Masayuki Obatake; Takayuki Tokunaga; Koji Hashizume; Kyoko Mochizuki; Takeshi Nagayasu

Tracheoinnominate artery fistula is known as a potentially fatal complication for patients who depend on tracheostomy or tracheoesophageal diversion. Since the bleeding from a TIF is often difficult to control, preventative procedures are recommended to avoid this complication. An 11-year-old girl with hypoxic-ischemic encephalopathy and scoliosis developed tracheal stenosis caused by compression from the innominate artery. Respiratory control with intubation through the tracheal stenosis was needed, and the patient was at high risk for developing a TIF. She underwent ligation of the innominate artery at tracheostomy. Subsequent tracheostomy revealed a widened tracheal lumen and no further complications. Prophylactic ligation of the innominate artery and creation of tracheostomy might be considered as a valid option for patients at high risk of developing TIF.


Acta Histochemica Et Cytochemica | 2013

Intratracheal Administration of Recombinant Human Keratinocyte Growth Factor Promotes Alveolar Epithelial Cell Proliferation during Compensatory Lung Growth in Rat

Katsuro Furukawa; Keitaro Matsumoto; Takeshi Nagayasu; Tomomi Yamamoto-Fukuda; Shuichi Tobinaga; Takafumi Abo; Naoya Yamasaki; Tomoshi Tsuchiya; Takuro Miyazaki; Ryotaro Kamohara; Atsushi Nanashima; Masayuki Obatake; Takehiko Koji

Keratinocyte growth factor (KGF) is considered to be one of the most important mitogens for lung epithelial cells. The objectives of this study were to confirm the effectiveness of intratracheal injection of recombinant human KGF (rhKGF) during compensatory lung growth and to optimize the instillation protocol. Here, trilobectomy in adult rat was performed, followed by intratracheal rhKGF instillation with low (0.4 mg/kg) and high (4 mg/kg) doses at various time-points. The proliferation of alveolar cells was assessed by the immunostaining for proliferating cell nuclear antigen (PCNA) in the residual lung. We also investigated other immunohistochemical parameters such as KGF, KGF receptor and surfactant protein A as well as terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Consequently, intratracheal single injection of rhKGF in high dose group significantly increased PCNA labeling index (LI) of alveolar cells in the remaining lung. Surprisingly, there was no difference in PCNA LI between low and high doses of rhKGF with daily injection, and PCNA LI reached a plateau level with 2 days-consecutive administration (about 60%). Our results indicate that even at low dose, daily intratracheal injection is effective to maintain high proliferative states during the early phase of compensatory lung growth.

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