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Dive into the research topics where Masanori Uchiyama is active.

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Featured researches published by Masanori Uchiyama.


Journal of Surgical Oncology | 2000

Treatment of childhood renal cell carcinoma with lymph node metastasis: two cases and a review of literature.

Masanori Uchiyama; Makoto Iwafuchi; Minoru Yagi; Yasushi Iinuma; Masahiro Ohtaki; Yoshihiko Tomita; Masayuki Hirota; Satoshi Kataoka; Keiko Asami

Standard treatment for renal cell carcinoma (RCC) is radical nephrectomy with lymph node dissection. Stages I and II have encouraging prognoses, but Stage III with regional lymph node metastasis can be unfavorable. Adjuvant therapy for pediatric patients with advanced RCC with lymph node involvement or metastatic lesion has not been defined. Advanced pediatric RCC is reported in two patients (boys, aged 6 and 9 years: Stage IIIs, Robson; Stage III and IV, pTNM classification) treated by nephrectomy and lymph node dissection followed by postoperative interferon‐α (IFN), that can be used as an adjuvant therapy with side effects such as fever, bone marrow suppression, or decreased liver function. One is doing well for 7 years, another is suffered from lung metastases at 3 years after surgery. Although immunotherapy is expected to improve survival in pediatric patients with advanced RCC, surgical resection of renal and metastatic tumors remains the standard treatment. J. Surg. Oncol. 2000;75:266–269.


Pediatric Surgery International | 2000

A case of Currarino triad with familial sacral bony deformities.

Yashushi Iinuma; Makoto Iwafuchi; Masanori Uchiyama; Minoru Yagi; Kimio Kondoh; Satoshi Ohtani; Satoshi Kanada; Takeshi Mishina; Hiroshi Saitoh

Abstract We describe a male patient presenting with Currarino triad: a recto-urethral fistula, sacral bony deformity, and a presacral teratoma. Clinical screening of his family revealed three additional cases with incomplete forms of this association. Cytogenetic findings in the patient and his mother were normal. This case suggests that the occurrence of an anorectal malformation together with a sacral bony deformity should raise a physicians index of suspicion for associated presacral tumors, and that screening of the patients family members with sacral radiographs is necessary.


Journal of Pediatric Surgery | 1991

Flow cytometric DNA analysis of neuroblastoma: Prognostic significance of DNA ploidy in unfavorable group

Masafumi Naito; Makoto Iwafuchi; Yoshihiro Ohsawa; Masanori Uchiyama; Masayuki Hirota; Yukio Matsuda; Yasushi Iinuma

Flow cytometric DNA content analyses were performed on samples of 54 patients with neuroblastoma. DNA aneuploidy was detected in 55.6% of the 54 patients. A high incidence of DNA aneuploidy was observed in patients with prognostically favorable variables such as age (less than 1 year), clinical stage (I, II, or IVs), and primary site (extraadrenal sites). DNA aneuploidy was predominant in surviving patients, even in those with unfavorable variables. In patients 1 year old or more, the survival rate among those with DNA aneuploidy was 58.8% compared with 28.6% in patients with diploidy. Likewise, in patients with advanced stage (III or IV) neuroblastoma, the survival rate among those with DNA aneuploidy was 63.2% compared with 30.4% in patients with DNA diploidy. It is concluded that DNA content analysis is of value in predicting the prognosis of patients with neuroblastoma.


Pediatric Surgery International | 1997

Electrogastrography after operative repair of esophageal atresia

Minoru Yagi; Shinji Homma; Makoto Iwafuchi; Masanori Uchiyama; Yukio Matsuda; T. Maruta

Esophageal atresia (EA) is a life-threatening disorder associated with operative complications. Post-operative gastric electrical control activity detected by a non-invasive electrogastrography (EGG) technique was investigated in 13 children aged 1–17 years to clarify whether gastric motility disorders were present. EGG abnormalities were present in 5 patients; persistent dysrhythmias were found in 3. Roentgenographic examinations showed mild gastroesophageal reflux in 3 (60%) of the dysrhythmic patients; 2 others had postprandial dysrhythmias. The mean spectral frequency (MSF) of EA cases with dysrhythmia was significantly higher than that of patients without dysrhythmia in both fasting and postprandial states (P < 0.05). The variability of the peak spectral frequencies (PSFV) in patients with dysrhythmia was significantly higher than in those without dysrhythmia in both fasting and postprandial states (P < 0.05). There were no significant differences in MSF and PSFV between EA patients without dysrhythmia and controls. These results suggest that gastric motor activity may be disordered in patients following operative repair of EA, although they remain asymptomatic. EGG may be a useful screening examination for postoperative gastric functional disorders.


Journal of Pediatric Surgery | 1994

Long-Term Results After Nonshunt Operations for Esophageal Varices in Children

Masanori Uchiyama; Makoto Iwafuchi; Yoshihiro Ohsawa; Shinichi Naito; Masafumi Naito; Minoru Yagi; Kazuhiro Tsukada

The clinical results of nonshunt operations for esophageal varices in 15 children were evaluated. The varices were caused by congenital extrahepatic portal obstruction (EHPO) in 10, liver cirrhosis or fibrosis (C/F) in 3, and idiopathic portal hypertension (IPH) in 2. The operative procedures were transthoracic esophageal transection with paraesophageal devascularization (TR) for 2 EHPO patients under 5 years of age, TR combined with splenectomy and paragastric devascularization (Sugiura procedure) for 11 (8 EHPO, 3 C/F), and splenectomy with devascularization (SP) or splenectomy for the 2 IPH patients. In the EHPO patient under 5 years of age, TR is associated with a likelihood of gastric or esophageal hemorrhage resulting from hypersplenism, gastric congestion, or persistent distal esophageal varices, which can be treated with partial splenic arterial embolization (PSE), endosclerotherapy, or an additional abdominal procedure. The Sugiura procedure has provided satisfactory long-term results, without rebleeding from esophageal varices, in patients with EHPO and C/F for 1 to 20 years. But EHPO patients who undergo the Sugiura procedure before age 6 can have gastric hemorrhage, because of mucosal congestion, for more than 10 years after the procedure, and selective gastric arterial embolization (GAE) might be necessary. In some EHPO patients, especially young ones who have variceal bleeding, a significant increase in hepatopetal portal flow may not develop, but hepatofugal natural shunts may progress. Therefore we recommend direct operative procedures, ie, TR for patients < or = 6 years of age and a one- or two-stage Sugiura procedure for those over 7 years old.(ABSTRACT TRUNCATED AT 250 WORDS)


Journal of Pediatric Gastroenterology and Nutrition | 1996

Intestinal motility after massive small bowel resection in conscious canines : Comparison of acute and chronic phases

Masanori Uchiyama; Makoto Iwafuchi; Yukio Matsuda; Masafumi Naitoh; Minoru Yagi; Satoshi Ohtani

To evaluate intestinal function after 80% massive distal small bowel resection (MSBR), we continuously monitored interdigestive and postprandial bowel motility using bipolar electrodes and/or contractile strain gauge force transducers in conscious beagle dogs before and at 2-4 weeks (acute postoperative phase; acute phase) and 8-13 months (chronic postoperative phase; chronic phase) after the surgery. Fasting duodenal migrating myoelectric (or motor) complexes (MMC) occurred at longer intervals in the acute phase after 80% MSBR than in control beagles. Intervals between duodenal MMC in the chronic phase were similar to those found in control beagles. MMC arising from the duodenum were often interrupted before the jejunum above the anastomosis in the acute phase, and a slight recovery of propagation frequency to the jejunum above the anastomosis was observed in the chronic phase. However, duodenal MMC did not migrate smoothly to the terminal ileum in both groups. In the acute phase, the velocity of duodenal MMC propagation was slowed in every intestinal segment, including the duodenum and the jejunum above the anastomosis, and had not recovered even long after the operation. The duration of the postprandial period without duodenal MMC was prolonged significantly in the acute phase postoperatively. Although it shortened in the chronic phase, it still remained significantly longer than in controls. These findings suggest that changes in gut motility after MSBR tend to compensate for the shorter intestine and maintain small bowel absorption early postoperatively. However, these compensatory changes decrease over the long term, and their adaptive contributions to increased intestinal absorption may decrease as well.


Journal of Pediatric Surgery | 1992

Intestinal myoelectric activity and contractile motility in dogs with a reversed jejunal segment after extensive small bowel resection

Masanori Uchiyama; Makoto Iwafuchi; Yoshihiro Ohsawa; Minoru Yagi; Yasushi linuma; Satoshi Ohtani

To evaluate the functioning and effectiveness of a reversed jejunal segment after extensive small bowel resection, we continuously measured the postoperative bowel motility (using bipolar electrodes and/or contractile strain gage force transducers) in interdigestive and postprandial conscious dogs at 2 to 5 weeks after surgery. The fasting duodenal migrating myoelectric (or motor) complex (MMC) occurred at markedly longer intervals in dogs with a 20-cm reversed jejunal segment created after 75% to 80% extensive small bowel resection (group 3) than in dogs that received extensive resection alone (group 2) or dogs that underwent construction of a reversed jejunal segment without bowel resection (group 1). The MMC arising from the duodenum was often interrupted at the jejunum above the proximal anastomosis and did not migrate smoothly to the reversed segment or terminal ileum in group 3. In addition, brief small discordant contractions were frequent in the reversed segment and the jejunum above the proximal anastomosis in group 3. The duration of the postprandial period without duodenal MMC activity was significantly prolonged in groups 2 and 3. These results suggest that the transit time and passage of intestinal contents were delayed and that the periodical MMC was disturbed in group 3. The delay of transit time was due to prolongation of the interval between duodenal MMCs, the interruption of MMC propagation at the jejunum above the proximal anastomosis, the dominance of MMCs that followed the inherent anatomical continuity of the bowel, and discordant movements across the proximal anastomosis. Functional obstruction could be a potential problem in a 20-cm reversed jejunal segment inserted after extensive small bowel resection.


Pediatrics International | 2001

Fiberoptic colonoscopic polypectomy in childhood: Report and review of cases

Masanori Uchiyama; Makoto Iwafuchi; Minoru Yagi; Yasushi Iinuma; Satoshi Kanada; Masahiro Ohtaki; Haruhiko Okamoto; Katsuyoshi Hatakeyama

Abstract 
 Background : Fiberoptic colonoscopy has been a routine therapeutic modality for colorectal polyps in pediatric patients. Methods of bowel preparation, anesthesia, area of investigation and treatment depending on histopathology are still controversial. In order to clarify the rationale of pediatric colonoscopy the present study was performed.


Journal of Pediatric Surgery | 1987

A case of congenital colonic atresia associated with atresia ani

Kohju Nitta; Makoto Iwafuchi; Yoshihiro Ohsawa; Masanori Uchiyama; Iwao Yamagiwa; Masayuki Hirota; Masafumi Naito; Keiko Hirokawa

The association of atresia ani with congenital colonic atresia is extremely rare, with only one such case having been reported up to date. We have recently treated a female infant with atresia ani (covered anus complete) accompanied by atresia of the sigmoid colon, who was managed by three stage surgery.


Medical & Biological Engineering & Computing | 2000

Isopower mapping of electrogastrograms in short-bowel syndrome.

Shinji Homma; Minoru Yagi; Masanori Uchiyama; Makoto Iwafuchi

Methods for making topographic or isopower electrogastrographic (EGG) maps and for obtaining maximum power foci (MPFs) by means of 27-channel EGG recordings are briefly described. The methods are applied to short-bowel syndrome (SBS). The gastro-intestinal tract is traced by videofluorograms after X-ray-opaque barium has been ingested. The MPFs are generally located on the trace of the gastrointestinal tract. The gastric area is occupied by 3 cycles min−1 (up to 28% of total MPFs) and 6 cycles min−1 MPFs (26%). The trace of the small intestine is occupied mainly by 8 cycles min−1 (39%) and 10 cycles min−1 (43%) MPFs. The trace of the colon is occupied almost evenly by all five spectral frequency groups, that is, by 1 (58%), 3 (53%), 6 (48%), 8 (57%) and 10 cycles min−1 (42%). Most interestingly, the numbers of 8–10 cycles min−1 power foci found on EGG maps (including MPFs and relatively higher power foci) are proportional to the remaining length at operation and to the length of the remaining small intestine in the long-term, over 6 years post-operatively. It is therefore possible to follow approximately the trace of the gasterointestinal tract.

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