Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Naohito Uchida is active.

Publication


Featured researches published by Naohito Uchida.


Digestive Diseases and Sciences | 1995

Papillary dilation vs sphincterotomy in endoscopic removal of bile duct stones. A randomized trial with manometric function.

Atsushi Minami; Toshiaki Nakatsu; Naohito Uchida; Shuko Hirabayashi; Hiroki Fukuma; Syed Ahmed Morshed; Mikio Nishioka

To circumvent the long-term effects of papillary ablation for extracting common bile duct stones (<12 mm in diameter) in endoscopic sphincterotomy (EST), endoscopic papillary dilation (EPD) was attempted in 20 patients. To evaluate papillary function before and after the procedures, manometry of the sphincter of Oddi was carried out in 13 with EPD and 10 of 20 patients with EST. Extraction of all stones was successful (100%) in both groups at an equal rate. Repeated numbers of procedures were common in both groups. However, the mean duration of the procedure was high in EPD compared to EST (63 min vs 42 min,P<NS). Adjunctive therapies like mechanical lithotripsy (ML), nasobiliary drainage, and choledochoscopy were included in EPD, while EST required a basket catheter and ML. There was no significant difference on manometry before and after the procedures (P=NS), although papillary function was found to have decreased after the EPD. In contrast, all patients in the EST group lost papillary function after the procedure. Thirty-day morbidity and mortality rate were absent in both groups. Immediate and 2.5-year follow up complications were uncommon in both groups. As a simple method, EPD may be an effective and safe alternative to EST in the management of patients with bile duct stones who require maintenance of papillary function.


European Journal of Cancer | 2003

pp60c-src activation in lung adenocarcinoma

Tsutomu Masaki; Kouichi Igarashi; M. Tokuda; S. Yukimasa; F. Han; Y.J. Jin; Jia-Qing Li; Hirohito Yoneyama; Naohito Uchida; Jiro Fujita; Hitoshi Yoshiji; Seishiro Watanabe; Kazutaka Kurokohchi; Shigeki Kuriyama

Nine src family members are known including c-Src, c-Yes, c-Lck, c-Fyn, c-Hck, c-Lyn, c-Blk, c-Fgr and c-Yrk. They encode proteins with molecular weights of 55-62 kilodaltons (kDa), which are either cytoplasmic or membrane-associated protein tyrosine kinases. A close correlation exists between an elevated pp60c-src tyrosine kinase activity and cell transformation. However, the level of activation of pp60c-src in non-small cell lung cancers (NSCLC) remains obscure. The aim of this study was to examine the level of activity of pp60c-src in NSCLC. pp60c-src expression and in vitro protein tyrosine kinase activity in lung cancer tissue samples were measured by western blotting and in vitro kinase assays and compared with those in the surrounding non-tumour lung tissue from the same patient. pp60c-src phosphorylation was assessed by two-dimensional tryptic phosphopeptide mapping. The kinase activity of pp60c-src was significantly activated in NSCLC, especially in adenocarcinomas. In addition, the pp60c-src kinase activity increased with the size of the adenocarcinoma. Two-dimensional tryptic phosphopeptide mapping showed dephosphorylation of pp60c-src at Tyr 530 in adenocarcinomas. The proto-oncogene product, pp60c-src, was activated in NSCLC, especially in adenocarcinomas, in part through the dephosphorylation of Tyr 530. Our results suggest that activation of pp60c-src might play an important role in the progression of lung adenocarcinomas.


Journal of Gastroenterology | 2007

Utility of pancreatic duct brushing for diagnosis of pancreatic carcinoma

Naohito Uchida; Hideki Kamada; Kunihiko Tsutsui; Masahiro Ono; Yuichi Aritomo; Tsutomu Masaki; Yoshio Kushida; Reiji Haba; Toshiaki Nakatsu; Shigeki Kuriyama

BackgroundThe aim of this study was to evaluate the usefulness of pancreatic duct brushing for diagnosis of pancreatic carcinoma.MethodsBrush cytology was attempted in 58 patients suspected of having pancreatic malignancy because of stricture of the main pancreatic duct, confirmed by endoscopic retrograde cholangiopancreatography. Thirty-eight patients were finally diagnosed by an operation or the clinical course as having pancreatic carcinoma, and the remaining 20 patients as having chronic pancreatitis. The usefulness of brush cytology for diagnosis of pancreatic carcinoma was estimated. We interpreted failures of pancreatic duct brushing to be false negatives when the lesion was malignant.ResultsIn 48 of 58 patients (82.8%), brushing was successfully performed and satisfactory specimens were obtained. Brush cytology was positive in 25 of 38 patients with pancreatic carcinoma (sensitivity 65.8%) and negative in all patients without malignancy (specificity 100%). Overall accuracy was 76.4%. During 2001–2005, the number of back-and-forth motions of the brush was increased to more than 30 times. The sensitivity significantly improved from 43.8% in 1997–2000 to 81.8% in 2001–2005 (P < 0.05). The increased success rate of brushing by improvement of skill in manipulating the guidewire and increased number of cells smeared on glass slides by increased back-and-forth motion of the brush may account for this improvement over time. Moreover, the sensitivity in 2001–2005 was 85.7% if failures of brushing with pancreatic carcinoma are excluded. No major complications occurred, except for two patients with a moderate grade of acute pancreatitis.ConclusionsAlthough further studies with a large number of patients are needed, our results suggest that with recent improvements of the brushing technique, pancreatic duct brushing is a useful and safe method for the differential diagnosis of malignancy from benign diseases of the pancreas.


Hepatology | 2004

Reduced expression of cell cycle regulator p18INK4C in human hepatocellular carcinoma

Asahiro Morishita; Tsutomu Masaki; Hitoshi Yoshiji; Seiji Nakai; Tomohiro Ogi; Yoshiaki Miyauchi; Shuhei Yoshida; Toshiharu Funaki; Naohito Uchida; Yuko Kita; Fumi Funakoshi; Hisashi Usuki; Setsuo Okada; Kunihiko Izuishi; Seishiro Watanabe; Kazutaka Kurokohchi; Shigeki Kuriyama

Cyclins, cyclin‐dependent kinases (Cdks), and Cdk inhibitors (CdkIs) are frequently altered in human cancer. p18INK4C, a member of the INK4 family of CdkIs, is a potential tumor‐suppressor gene product. However, the expression of p18INK4C in hepatocellular carcinoma (HCC) remains unknown. The aim of this study was to examine the expression of p18INK4C in various liver diseases including HCC and to assess its clinical significance in HCC. To that end, we examined the expression of p18INK4C by immunohistochemistry in various liver diseases, including 51 HCCs, and also studied the relationship between p18INK4C expression, the phosphorylation of retinoblastoma protein (pRb), and the activity level of Cdk4 and Cdk6. Immunohistochemical analysis revealed the frequent loss of p18INK4C expression in HCC, especially in poorly differentiated HCC. The loss of p18INK4C expression was shown to be associated with a poor prognosis compared with that associated with p18INK4C‐ positivity. Further, the kinase activity of Cdk4 was found to be higher in p18INK4C‐negative HCCs than in p18INK4C‐ positive HCCs. However, the level of Cdk6 activity was similar in the 2 groups of HCCs. In p18INK4C‐ positive HCCs, p18INK4C dominantly interacted with Cdk4 rather than with Cdk6. pRb phosphorylated at serine(Ser) 780 was detected more frequently in p18INK4C ‐ negative than in p18INK4C ‐ positive HCCs. In conclusion, the loss of p18INK4C expression may play a role in the differentiation and development of HCC through the up‐regulation of Cdk4 activity. (HEPATOLOGY 2004;40:677–686.)


Journal of Gastroenterology | 2005

Adenocarcinoma arising from aberrant pancreas in the stomach.

Michiko Matsuki; Yoshinori Gouda; Takashi Ando; Hiroshi Matsuoka; Tsubasa Morita; Naohito Uchida; Shigeki Kuriyama

We report herein a rare case of malignant transformation of aberrant pancreas in the stomach, associated with gastric outlet obstruction. A 58-year-old woman was admitted to our hospital, complaining of vomiting. Although barium meal examination and gastric endoscopy showed marked pyloric stenosis, the biopsy specimen obtained from the stenotic site revealed regenerative mucosa without malignancy. Abdominal computed tomography and endoscopic ultrasono-graphy (EUS) also could not detect the cause of the obstruction. Histopathological examination of the surgically resected specimen showed the malignant transformation of aberrant pancreas in the stomach. It should be noted that one of the causes of gastric outlet obstruction may be aberrant pancreas or its malignant transformation.


Journal of Gastroenterology | 2007

Usefulness of single and repetitive percutaneous transhepatic gallbladder aspiration for the treatment of acute cholecystitis

Kunihiko Tsutsui; Naohito Uchida; Shuko Hirabayashi; Hideki Kamada; Masahiro Ono; Mutsumi Ogawa; Toru Ezaki; Hiroki Fukuma; Hideki Kobara; Yuichi Aritomo; Tsutomu Masaki; Toshiaki Nakatsu; Shigeki Kuriyama

BackgroundThe aim of this study was to evaluate the safety and usefulness of single and repetitive percutaneous transhepatic gallbladder aspiration (PTGBA) for the treatment of acute cholecystitis.MethodsPTGBA was performed in patients with acute cholecystitis who showed no improvement after treatment with broad-spectrum antibiotics. PTGBA was carried out at bedside. When the bile was too thick to be aspirated through a 21-gauge needle, an 18-gauge needle was used. Aspiration of the gallbladder contents and injection of antibiotics into the gallbladder were performed without the placement of a drainage catheter. When improvement was not observed after the first attempt, PTGBA was repeated.ResultsSingle PTGBA achieved improvement in 32 of 45 patients. In 11 of the remaining 13 patients, the second PTGBA was effective. In the remaining two patients, repetitive PTGBA was not carried out because of advanced cancer. In two of 45 patients, 18-gauge needles were necessary for PTGBA because of the high viscosity of the bile. PTGBA was carried out in three patients with blockage of the cystic duct by a stent, and it was effective in all three. Two patients whose conditions improved with a single PTGBA experienced a recurrence at 4 and 31 months, respectively, after PTGBA. No other severe complications related to PTGBA were observed in any patients.ConclusionsFor the treatment of acute cholecystitis that does not react to conservative therapies, PTGBA is a safe, simple, and effective treatment modality that can be performed at bedside without any severe complications.


Journal of Gastroenterology | 2005

Estimation of the stent placement above the intact sphincter of Oddi against malignant bile duct obstruction

Naohito Uchida; Kunihiko Tsutsui; Toru Ezaki; Hiroki Fukuma; Hideki Kamata; Hideki Kobara; Hiroshi Matsuoka; Fumihiko Kinekawa; Yuichi Aritomo; Fumi Yokoyama; Yuko Kita; Tsutomu Masaki; Mutsumi Ogawa; Toshiaki Nakatsu; Seishiro Watanabe; Shigeki Kuriyama

BackgroundIn endoscopic biliary stenting against malignant biliary obstruction, stent blockage remains as an important problem. Stent blockage occurs as a result of bacterial adherence to the inner wall of the stent. We evaluated the stent placement above the intact sphincter of Oddi to retain the function of the sphincter of Oddi as a bacteriological barrier.MethodsSixteen patients with malignant biliary obstruction were assessed as the patients with the stent above the intact sphincter of Oddi. Sixteen patients with malignant biliary obstruction were assessed as the patients with the conventional stent placement across the sphincter of Oddi. Tannenbaum 10-Fr. stents were used in both the groups.ResultsThe median patency periods of the stent were 255 days (25th to 75th percentiles, 212–454 days; range, 39–454 days) for the group of the stents placed above the sphincter of Oddi and 82 days (25th to 75th percentiles, 48–131 days; range, 22–196 days) for the group of the stents placed across the sphincter of Oddi, respectively, with significant difference (P = 0.0001). The occlusion rates of stents placed above and across the sphincter of Oddi were 37.5% and 93.8%, respectively, with significant difference (P = 0.0008). The dislocation rates of the stent were 0% and 6.3%, respectively (not significant).ConclusionsPlacement of the stent above the intact sphincter of Oddi was associated with longer stent patency and lower occlusion rate.


Journal of Hepato-biliary-pancreatic Surgery | 1997

Endoscopic transpapillary gallbladder drainage (ETGBD) for the treatment of acute cholecystitis

Toshiaki Nakatsu; Hiroshi Okada; Kunio Saito; Naohito Uchida; Atsushi Minami; Toru Ezaki; Syed Ahmed Morshed; Mikio Nishioka

We performed endoscopic transpapillary gallbladder drainage (ETGBD) in 21 patients with acute cholecystitis, utilizing a guidewire coated with a hydrophilic polymer. Endoscopic sphincterotomy was not performed. The clinical efficacy of ETGBD was evaluated in terms of reduction of white blood cell count (WBC) and C-reactive protein (CRP) level. ETGBD was successful in 17 (81%) of the 21 patients, in terms of early disappearance of clinical symptoms, and significant decrease of both WBC and CRP after ETGBD (P< 0.001). In patients with the Mirizzi syndrome (n=2), accurate diagnosis was made by endoscopic retrograde cholangiography (ERC), facilitating proper drainage (ETGBD) immediately afterward. With ETGBD, emergency operation was avoided even in critically ill patients complicated with disseminated intravascular coagulopathy (n=2). There were no significant complications. ETGBD may be an effective and safe alternative to percutaneous transhepatic gallbladder drainage in the management of acute cholecystitis, and may be more suitable for patients with a strong bleeding tendency.


Journal of Gastroenterology | 2003

Concomitant colitis associated with primary sclerosing cholangitis.

Naohito Uchida; Toru Ezaki; Hiroki Fukuma; Kunihiko Tsutsui; Hideki Kobara; Miho Matsuoka; Tsutomu Masaki; Seishiro Watanabe; Mitsuo Yoshida; Tsuyoshi Maeta; Fumikazu Koi; Toshiaki Nakatsu; Shigeki Kuriyama

Between 1985 and 2001, seven Japanese patients (four males and three females) were diagnosed as having primary sclerosing cholangitis (PSC) in our hospital. All seven patients received total colonoscopy with distal ileoscopy. All four male patients were diagnosed as having colitis by colonoscopy, while none of the three female patients had colitis. The four patients with colitis did not have any symptoms attributable to colitis, such as diarrhea or hematochezia. In three of the four patients, unclassified colitis was the most suitable diagnosis, because there were no typical findings of ulcerative colitis or Crohns disease. The remaining patient was diagnosed as having eosinophilic colitis. By colonoscopic visualization, the right-sided colon, including the terminal ileum, was mainly involved, but the lesions were not severe. The main findings were redness, erosion, stenosis, and insufficiency of haustral formation. Histologically, these lesions were nonspecific inflammatory changes in the three patients with unclassified colitis. In the patient with eosinophilic colitis, remarkable infiltration of eosinophils was observed. Thus, unclassified colitis appeared to be the main complication in these patients with PSC. Males predominated in regard to concomitant colitis, and they had no symptoms of the colitis. Colonoscopic examination revealed that the lesions were not severe. The main lesions were found in the right-sided colon, with nonspecific inflammatory changes. These results suggest that colonoscopic surveillance of patients with PSC should be performed even if they do not have any colitis symptoms.


Journal of Gastroenterology and Hepatology | 2008

How many cytological examinations should be performed for the diagnosis of malignant biliary stricture via an endoscopic nasobiliary drainage tube

Naohito Uchida; Hideki Kamada; Masahiro Ono; Yuichi Aritomo; Tsutomu Masaki; Toshiaki Nakatsu; Shigeki Kuriyama

Background and Aim:  The sensitivity of bile cytology is recognized as being low. Repeating cytological sampling is likely to improve the sensitivity. The aim of this study is to determine the optimal number of repeated cytological sampling of bile obtained via an endoscopic nasobiliary drainage (ENBD) tube for the diagnosis of malignant biliary stricture.

Collaboration


Dive into the Naohito Uchida's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge