Histopathology of type C liver disease for determining hepatocellular carcinoma risk factors

AIM:To evaluate the histopathological findings of type C liver disease to determine risk factors for development of hepatocellular carcinoma(HCC).METHODS:We studied 232 patients,who underwent liver biopsy for type C chronic liver disease between 1992 and 2009,with sustained virological response(SVR)after interferon therapy.The patients were divided into two groups according to the F stage 0+1+2 group(n = 182)and F3+4 group(n = 50).We prospectively observed and compared the incidence of HCC of the patients with SVR in the F0+1+2 and F3+4 groups.Then,the background factors and liver histopathological findings,including the degree of fibrosis,F stage,inflammation,necrosis,bile duct obstruction,fat deposition,and degree of irregular regeneration(IR)of hepatocytes,were correlated with the risk of developing HCC.RESULTS:HCC developed in three of 182(1.6%)patients in the F0+1+2 group,and four of 50(8.0%)in the F3+4 group.The cumulative incidence of HCC in the former group was found to be significantly lower than in the F3+4 group(log rank test P = 0.0224).The presence of atypical hepatocytes among IR of hepatocytes in the F3+4 group resulted in a higher cumulative incidence of HCC,and was significantly correlated with risk of HCC development(RR = 20.748,95%CI:1.335-322.5,P = 0.0303).CONCLUSION:Atypical hepatocytes among the histopathological findings of type C liver disease may be an important risk factor for HCC development along with progression of liver fibrosis.

In-situ evaluation for activated concrete in accelerator facility with scintillation-type gamma-ray spectrometer

The assessment of activated concrete is particularly difficult during the decommissioning of an accelerator facility.Destructive analysis by core boring is the only method of investigating the activity of concrete material.To address this problem,an in-situ and nondestructive analysis method was developed to determineγ-ray-emitting nuclides and their specific activities in the concrete walls and floor by using a portable germanium semiconductor detector.In this work,we examined a substitute for Ge detector to establish a simpler and more convenient method.As candidates,we focused on some scintillation type spectrometers,and the possibility of a substitute for a Ge detector was examined by both simulation and experiment.The detection limits were roughly estimated through Monte Carlo simulation for various scintillation crystals,and it was found that 1.5-inch LaBr3,CeBr3,and SrI2 could distinguish the clearance level.It was confirmed that the 1.5-inch LaBr3 could reproduce the calibration curve of the Ge detector in the experiment.The required thickness and length of the radiation shield for suppressing the background radiation during the measurement was also determined for the convenience of an actual decommissioning work.

Nondestructive high-sensitivity measurement method for activation estimation in accelerator room concrete

This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an accelerator.We propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation zoning.In this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron flux.The obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated concrete.This method is a powerful long-term prediction tool for concrete activation.