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Biomedical subjects

Ryo Nakata

Publications and source records attributed to Ryo Nakata.

6 recordsLinked to original sources
PubMed2005

Delayed development of hepatocellular carcinoma during long-term follow-up after eradication of hepatitis C virus by interferon therapy.

A 42-year-old Japanese man with liver cirrhosis by hepatitis C virus (HCV) had successful interferon therapy in May 1991. Since then, serum HCV-RNA and liver function tests had been negative. He had continued to drink more than 100 g/d of alcohol as before. In June 2003, a 5-cm tumor was found in the posterior segment of the liver. The tumor was curatively resected and the surgical specimen showed a well-differentiated hepatocellular carcinoma (HCC). Non-cancerous lesions of the liver revealed fibrosis at stage F3 with minimal to mild inflammation of grade A1. Heavy drinking may retard the dissolution of fibrosis and accelerate HCC development in patients with sustained virological response.

Adult↗
PubMed2005

Antiviral therapy for cirrhotic hepatitis C: association with reduced hepatocellular carcinoma development and improved survival.

BACKGROUND: Although cirrhosis is a major risk factor for development of hepatocellular carcinoma, no definitive prospective analyses have assessed the long-term efficacy of antiviral therapy in cirrhotic patients. OBJECTIVE: To elucidate the role of antiviral therapy in the suppression of liver tumors and survival over a long-term follow-up period. DESIGN: Prospective cohort study. SETTING: 25 clinical centers. PATIENTS: 345 patients with chronic hepatitis C and cirrhosis enrolled in previous trials. INTERVENTION: 271 patients received 6 to 9 million U of interferon 3 times weekly for 26 to 88 weeks; 74 received no treatment. MEASUREMENTS: Blood tests and abdominal ultrasonography were done regularly to detect hepatocellular carcinoma. RESULTS: Hepatocellular carcinoma was detected in 119 patients during a 6.8-year follow-up: 84 (31%) in the interferon-treated group and 35 (47%) in the untreated group. Cumulative incidence of hepatocellular carcinoma among interferon-treated patients was significantly lower than in untreated patients (Cox model: age-adjusted hazard ratio, 0.65 [95% CI, 0.43 to 0.97]; P = 0.03), especially sustained virologic responders. A total of 69 patients died during follow-up: 45 (17%) in the treated group and 24 (32%) in the untreated group. Interferon-treated patients had a better chance of survival than the untreated group (Cox model: age-adjusted hazard ratio, 0.54 [CI, 0.33 to 0.89]; P = 0.02). This was especially evident in sustained virologic responders. LIMITATION: This was not a randomized, controlled study. Patients enrolled in the control group had declined to receive interferon treatment even though they were eligible for treatment. CONCLUSION: Interferon therapy for cirrhotic patients with chronic hepatitis C, especially those in whom the infection had been cured, inhibited the development of hepatocellular carcinoma and improved survival.

Antiviral Agents↗
PubMed2005

Risk factors for pancreatitis in patients with common bile duct stones managed by endoscopic papillary balloon dilation.

OBJECTIVES: Endoscopic papillary balloon dilation has been accepted as a possible alternative to endoscopic sphincterotomy, especially in patients with impaired hemostasis. However, pancreatitis associated with endoscopic papillary balloon dilation has remained a controversial, serious issue. The aim of the study was to investigate the risk factors for postendoscopic papillary balloon dilation pancreatitis in a single-center study. METHODS: A total of 304 patients who underwent endoscopic papillary balloon dilation for the management of common bile duct stones were enrolled. The risk of postendoscopic papillary balloon dilation pancreatitis was evaluated and the risk factors were analyzed by univariate and multivariate analysis. Definition and grade of the severity of postendoscopic papillary balloon dilation pancreatitis were based on the 1991 consensus guidelines. RESULTS: Common bile duct was cleared in 292 of 304 patients (96%). Procedure-related pancreatitis occurred in 15 patients (5.0%). The grade was mild in 8 and moderate in 7. Two risk factors, stone diameter and contrast medium injection to the pancreas, were identified by univariate analysis. Finally, only the contrast medium injection to the pancreas was statistically significant by multivariate analysis. Prior history of pancreatitis was identified as a risk factor for postendoscopic papillary balloon dilation pancreatitis in previous studies, but this factor was not identified as a risk factor in our series. CONCLUSIONS: Although the pathogenesis of pancreatitis after endoscopic papillary balloon dilation remains unresolved, the unnecessary injection of contrast medium to the pancreas can certainly be considered to be associated with the increased risk of pancreatitis.

Aged↗
PubMed2003

Involvement of the biliary system in autoimmune pancreatitis: a follow-up study.

BACKGROUND & AIMS: The aim of this study was to define the bile duct changes associated with autoimmune pancreatitis. METHODS: Eight patients with autoimmune pancreatitis were followed for a mean of 4 years. The clinical features of these patients, including extrapancreatic bile duct changes, were examined by using biochemical parameters and several imaging modalities. Pathologic features of the pancreas and liver were examined by using the biopsy specimens of 7 patients. RESULTS: Diffuse or focal narrowing of the main pancreatic duct was observed in all patients. Histologic examination of the pancreas showed lymphoplasmacyte infiltration with severe fibrosis and acinar cell depletion. In 6 patients extrapancreatic bile duct changes such as stricture of the bile duct at hilus or intrahepatic area were observed. In 2 patients abnormalities in the bile duct and pancreas were detected simultaneously at diagnosis, and changes in the bile duct were observed later in 4 patients. Lymphoplasmacyte infiltration and fibrosis were observed in the portal area of all 7 liver biopsy samples. Five of the patients with bile duct changes received steroid therapy, and the pathological changes improved. CONCLUSIONS: Extrapancreatic bile duct changes are frequently associated with autoimmune pancreatitis. Similar pathogenic mechanism might produce the biliary tract and pancreatic abnormalities in autoimmune pancreatitis resulting in a similar histopathology in the liver and pancreas and response to steroid therapy.

Aged↗