Application of a wet oxidation method for the quantification of ³H and ¹4C in low-level radwastes.

Wet oxidation methods are utilized to separate and quantify (3)H and (14)C radionuclides in inorganic and organic radwastes generated at nuclear facilities. Because (3)H and (14)C are pure beta emitters with half-lives of 12.3 and 5,730 years, respectively, these radionuclides should be chemically separated from other radionuclides present in radwastes for accurate quantification. In particular, a collection technique for (14)C radionuclide in radwastes is needed because it is converted into (14)CO2 gas by an oxidation reaction. To confirm the recoveries of (3)H and (14)C, various standard radioactive sources were used to verify the proposed method. Because the majority of (3)H radionuclides are distributed in tritiated water (HTO), only tritiated water was used as a standard for (3)H radionuclides. Additionally, (14)C-labeled methanol ((14)CH3OH), lauric acid ((14)CH3(CH2)10COOH), sodium bicarbonate (NaH(14)CO3), and toluene (C6H5(14)CH3) were used as (14)C standards. The compounds were oxidized with chemical oxidants and then separated. The individual species were mixed with a scintillation cocktail and counted using a liquid scintillation counter. The recoveries of (14)C and (3)H were 82-97% and 98%, respectively. The wet oxidation method will be applied to RI wastes for clearance.

Durability of HBeAg seroconversion following antiviral therapy for chronic hepatitis B: relation to type of therapy and pretreatment serum hepatitis B virus DNA and alanine aminotransferase.

BACKGROUND AND AIMS: Interferon (IFN) induced hepatitis B e antigen (HBeAg) seroconversion is durable in 80-90% of chronic hepatitis B patients. Preliminary reports on the durability of HBeAg seroconversion following lamivudine are contradictory. We investigated the durability of response following IFN, lamivudine, or IFN-lamivudine combination therapy in a meta-analysis of individual patient data. PATIENTS AND METHODS: Twenty four centres included 130 patients in total with an HBeAg seroconversion (HBeAg negative, antibodies to hepatitis B e antigen positive) at the end of antiviral therapy: 59 with lamivudine, 49 with interferon, and 22 with combination therapy. Relapse was defined as confirmed reappearance of HBeAg. RESULTS: The three year cumulative HBeAg relapse rate by the Kaplan-Meier method was 54% for lamivudine, 32% for IFN, and 23% for combination therapy (p=0.01). Cox regression analysis identified pretreatment hepatitis B virus (HBV) DNA, alanine aminotransferase (ALT), sex, and therapy as independent predictive factors of post-treatment relapse; Asian race, previous therapy, centre, and type of study were not predictive of relapse. The relative HBeAg relapse risk of lamivudine compared with IFN therapy was 4.6 and that of combination therapy to IFN therapy 0.7 (p(overall)=0.01). CONCLUSIONS: The durability of HBeAg seroconversion following lamivudine treatment was significantly lower than that following IFN or IFN-lamivudine combination therapy. The risk of relapse after HBeAg seroconversion was also related to pretreatment levels of serum ALT and HBV DNA, but independent of Asian race.

Close correlation of p53 mutation to microvascular invasion in hepatocellular carcinoma.

Mutation of p53 is a poor prognostic indicator of hepatocellular carcinoma (HCC). Although poor histologic differentiation of HCC has been associated with p53 mutations, the exact reasons for unfavorable clinical outcomes in patients with HCC remain to be clarified. In this study, we evaluate the association between p53 mutation and histopathologic features of HCCs, as well as tumor recurrences and survival. We examined 20 HCCs and surrounding liver tissues from patients who underwent surgical resection, and we performed direct sequencing of p53 gene. p53 mutations were found in 9 of 20 HCCs; none were found in the surrounding liver tissue. p53 mutations were frequent in large, multinodular, and poorly differentiated HCCs. Five of 9 with p53 mutation (in contrast, none of 11 with wild-type mutation) showed microvascular invasions. Hepatocellular carcinoma recurred in 6 of 9 with p53 mutation, in contrast to only 2 of 11 with wild-type mutation. The 1-year survival rate with p53 mutation was significantly lower than that with wild-type. In conclusion, it is suggested that p53 mutations tend to be commonly associated with microvascular invasions, which may result in micrometastasis, followed by frequent recurrences.

Plasma isocitrate dehydrogenase as a marker of centrilobular hepatic necrosis in patients with hyperthyroidism.

Isocitrate dehydrogenase (ICDH) may be useful for differentiating centrilobular from periportal necrosis in rats with liver injury. In this study, we assessed the usefulness of ICDH as a marker of centrilobular necrosis in patients with hyperthyroidism. Isocitrate dehydrogenase and alanine aminotransferase (ALT) activities were measured in the plasma of 56 patients with hyperthyroidism, 16 patients with chronic viral hepatitis (CVH), and 17 controls. Isocitrate dehydrogenase levels were higher in patients with hyperthyroidism than in those with CVH or in the controls (p < 0.01 and p < 0.001, respectively), even though ALT levels were higher in patients with CVH than in patients with hyperthyroidism (p < 0.01). Isocitrate dehydrogenase/ALT ratios were also higher in patients with hyperthyroidism than in those with CVH (p < 0.0001). Isocitrate dehydrogenase correlated to ALT levels in patients with hyperthyroidism or CVH (p < 0.05). In a patient with hyperthyroidism, ICDH levels decreased progressively to normal, and the ALT level and thyroid function were normalized. Thus, the plasma ICDH or ICDH/ALT ratio might be useful for differentiating centrilobular from periportal necrosis and for monitoring the degree of hepatic necrosis in patients with hyperthyroidism.

Association between insulin-like growth factor-2 and metastases after transcatheter arterial chemoembolization in patients with hepatocellular carcinoma: a prospective study.

BACKGROUND: Hypoxia up-regulates insulin-like growth factor-2 (IGF-2) and thus stimulates the growth of hepatocellular carcinoma (HCC) cells. In the current study, the authors prospectively evaluated changes in plasma IGF-2 levels in HCC patients after transcatheter arterial chemoembolization (TACE), which usually results in hypoxic insult to liver tissue. The authors also examined the association between changes in plasma IGF-2 levels after TACE and HCC progression, especially in relation to metastasis. METHODS: Plasma IGF-2 levels were measured before and 4 weeks after TACE in 46 patients with HCC. Three months after TACE, the patients were evaluated for the occurrence of metastatic HCC. RESULTS: In 13 of the 46 patients, post-TACE plasma IGF-2 levels decreased by > 20% (Group 1) compared with their basal levels; in 18 patients, the IGF-2 levels changed within 20% (Group 2) and in 15 patients the IGF-2 levels increased by > 20% (Group 3). Plasma IGF-2 levels had a tendency to increase in patients with large-sized tumors, high serum alpha-fetoprotein (AFP) levels, and the heterogeneous uptake of iodized oil. Metastatic foci were found in 9 patients in Group 3 (60%), in contrast to only 3 patients in Group 2 (17%) and in none of the patients in Group 1 (P = 0.001). On multivariate analysis, higher Child-Pugh scores and increased plasma IGF-2 levels (Group 3) were found to be independent risk factors for metastasis. CONCLUSIONS: Increased plasma IGF-2 levels after TACE, which are common in patients with large-sized tumors and high serum AFP levels, appear to be associated with the occurrence of metastatic HCC after TACE.

Isocitrate dehydrogenase as a marker of centrilobular hepatic necrosis in the experimental model of rats.

BACKGROUND AND AIMS: Serum alanine aminotransferase (ALT) and aspartate aminotransferase may not detect centrilobular hepatic necrosis (CLN) of a mild degree because these enzymes are known to be located predominantly in the periportal area. The aim of this study was to evaluate the usefulness of plasma isocitrate dehydrogenase (ICDH), which is located predominantly in the centrilobular zone, as a marker of CLN. METHODS: In 56 adult male rats, centrilobular (n = 21) and periportal hepatic necrosis (PPN; n = 21) were induced experimentally by the intraperitoneal injection of bromobenzene and allylalcohol, respectively. Seven rats were used as solvent controls in both groups. Isocitrate dehydrogenase and ALT activities were measured in the plasma of rats with mild to moderate hepatic necrosis (17 CLN and 19 PPN). Isocitrate dehydrogenase and ALT were compared according to the sampling time (12, 24 and 48 h) and the location of hepatic necrosis. Ratios of ICDH/ALT were also calculated and compared between CLN and PPN groups at any time points. RESULTS: Plasma ICDH activities were higher in rats with CLN than in those with PPN. In contrast, plasma ALT levels were higher in rats with PPN than in those with CLN at 12 h and were similar in both groups after 12 h. The ICDH/ALT ratios were much higher in rats with CLN compared to those with PPN (P< 0.001). The ratios were above 1.0 in 13 of 17 rats (77%) with CLN in contrast to none of the 19 rats with PPN. CONCLUSIONS: Our data suggested that the plasma ICDH/ALT ratio might be useful to differentiate between mild to moderate degrees of CLN from PPN, at least in the experimental model of rats.

Ischemic bile duct injury as a serious complication after transarterial chemoembolization in patients with hepatocellular carcinoma.

BACKGROUND: Bile duct injuries after transarterial chemoembolization (TACE) have been reported; however, the exact pathogenic mechanisms and clinical implications of the injuries remain to be clarified. STUDY: A total of 950 consecutive patients with hepatocellular carcinoma (HCC) were studied. Among them, 807 were treated with TACE and the remaining 143 were treated with transarterial chemoinfusion (TACI) of cisplatin. RESULTS: None of 143 patients with HCC treated with TACI were found to have any radiographic evidence of biliary injury. In contrast, of the 807 patients treated with TACE, 17 (2%) developed biliary complications. Of all complications, 12 (71%) were subcapsular bilomas; 3 (17%), focal strictures of the common hepatic duct or common bile duct; and 2 (12%), diffuse mild dilatation of the intrahepatic bile ducts. Interestingly, 2 of the 12 bilomas were found in the lobe that was not embolized with gelatin sponge particles. The median numbers of TACE tended to be greater in the patients with focal stricture than in those with bilomas (6.0 vs. 2.5; p = 0.08). All 3 patients with focal strictures and 4 of the 12 patients with bilomas had associated serious bacterial infections at presentation. CONCLUSIONS: Bilomas seem to be caused by iodized oil rather than gelatin sponge particles; focal strictures of large bile ducts seem to be caused by gelatin sponge particles. We suggest that adjustments in the amounts of iodized oil or gelatin sponge particles and in the sites of embolization may reduce ischemic biliary injuries after TACE.

Methimazole interferes with the progression of experimental autoimmune myocarditis in rats.

In order to ascertain whether methimazole, a drug commonly used for the treatment of hyperthyroidism, interferes with the progression of autoimmune-mediated myocardial injury, we investigated the effect of methimazole on experimental autoimmune myocarditis (EAM) in rats. EAM was induced by immunization with porcine cardiac myosin. Methimazole administration markedly slowed the body weight growth in both normal and EAM rats, but did not induce morphologic change of cardiac tissue in normal rats. In EAM rats, macroscopic examination revealed discoloration of the cardiac surface, and histopathological examination by light microscopy showed extensive myocardial necrosis, infiltration by inflammatory cells and myocardial fibrosis. In the EAM rats treated with methimazole, the discolored areas on the cardiac surface were markedly diminished in size, and the myocardial necrosis, cellular infiltration and fibrosis were significantly less severe. To identify the mechanism responsible of this effect, we investigated the change of regulatory lymphocyte subsets in peripheral blood using an immunofluorescence technique with a flow cytometer. A decrease in the helper/suppressor T cell ratio as a result of the increased proportion of suppressor T cells and a decrease in the proportion of B cells were observed in normal rats after methimazole administration, and similar findings were made in the EAM rats treated with methimazole. These results indicate that methimazole interferes with the progression of EAM, and immunosuppression may, at least in part, be involved in the inhibitory effect of methimazole on EAM in rats.

Hepatitis B e antigen seroconversion after lamivudine therapy is not durable in patients with chronic hepatitis B in Korea.

It has been suggested that hepatitis B e antigen (HBeAg) seroconversion after lamivudine therapy is durable in Caucasians with chronic hepatitis B (CHB). However, little is known whether it is also durable in endemic areas of hepatitis B virus (HBV) infection. We evaluated the posttreatment durability of lamivudine-induced HBeAg seroconversion and the predictive factors for relapse in Korean patients with CHB. We retrospectively analyzed 98 HBeAg-positive patients with CHB who were treated with lamivudine between August 1996 and December 1997. Lamivudine was given at a dose of 150 mg per day. After HBeAg seroconversion, lamivudine was continued for an additional 2 to 4 months, and posttreatment monitoring continued for up to 24 months. HBeAg seroconversion was achieved in 34 of the 98 patients (34.7%). The mean duration of treatment in these seroconverters was 9.3 +/- 3.0 months. During the follow-up period, the cumulative relapse rates at 1 year and 2 years posttreatment were 37.5% and 49.2%, respectively. Most relapses were accompanied by elevation of serum alanine transaminase (94%) and reappearance of HBeAg (81%). Pretreatment serum HBV DNA levels and the duration of additional lamivudine therapy after HBeAg seroconversion were 2 independent predictive factors for posttreatment relapse. In conclusion, lamivudine-induced HBeAg seroconversion was not durable in this endemic area. And the duration of additional lamivudine therapy after HBeAg seroconversion significantly affected the posttreatment relapse. Further studies are needed to determine the duration of lamivudine and to elucidate the cause of high relapse after HBeAg seroconversion in endemic areas of HBV.

Expression of transforming growth factor-alpha mRNA in livers of patients with chronic viral hepatitis and hepatocellular carcinoma.

BACKGROUND: Transforming growth factor-alpha (TGFalpha) is an important autocrine growth factor of hepatocytes. The authors evaluated the roles of TGFalpha in chronic viral hepatitis (CVH) and hepatocellular carcinoma (HCC). METHODS: The authors measured the amounts of TGFalpha mRNA in liver tissues from 18 patients with HCC, 31 patients with CVH, and 7 normal controls. " Hot-start" reverse transcription-polymerase chain reaction (RT-PCR) using oligo-dT and specific primers detected TGFalpha mRNA in total cellular RNA extracted from liver tissues. The levels of TGFalpha mRNA were determined by the end point titers of serial, two-fold dilutions of cDNA. The amounts of hepatitis B virus RNA (HBV-RNA) in livers of patients with chronic hepatitis B also were measured by Northern blot hybridization. RESULTS: TGFalpha mRNA levels were extremely higher in patients with HCC compared with patients with CVH and normal controls, and the levels in patients with CVH also were elevated compared with normal controls. The levels of TGFalpha mRNA were overexpressed in the underlying livers of patients with HCC compared with patients with CVH, although they were lower than those found in HCC tissues. The levels of TGFalpha mRNA were higher in samples from patients with chronic hepatitis B than in samples from patients with chronic hepatitis C. The levels of TGFalpha mRNA were not correlated with serum alanine aminotransferase or HBV-RNA levels in liver tissues in patients with chronic hepatitis B. However, the expression of TGFalpha mRNA tended to be higher in the livers of patients with raised serum alpha-fetoprotein levels. CONCLUSIONS: The overexpression of TGFalpha mRNA in the liver seems to be associated with the regeneration of hepatocytes rather than hepatic necrosis or viral replication. Also, it may be related closely to the development or progression of HCC, especially in the livers of patients with chronic hepatitis B.

Combined therapy consisting of intraarterial cisplatin infusion and systemic interferon-alpha for hepatocellular carcinoma patients with major portal vein thrombosis or distant metastasis.

BACKGROUND: Hepatocellular carcinoma (HCC) patients with major vascular involvement or extrahepatic metastasis are not good candidates for surgery or transarterial chemoembolization (TACE). In this study, the authors evaluated the efficacy of combined therapy with intraarterial cisplatin infusion and systemic administration of interferon-alpha (IFN-alpha) as a palliative treatment for these patients. METHODS: Sixty-eight HCC patients with major portal vein thrombosis (n = 47) or distant metastasis (n = 27) were randomly allocated to 1 of 3 groups. Group I (n = 19) received combined therapy consisting of intraarterial cisplatin infusion and systemic IFN-alpha, Group II (n = 23) received intraarterial cisplatin infusion, and Group III (n = 26) was managed with only supportive care. Cisplatin 2 mg/kg was infused through the proper hepatic artery every 8 weeks, and IFN-alpha 3 million IU/m2 was administered subcutaneously 3 times a week. RESULTS: The partial response (defined as a 50% or greater reduction in the product of the 2 longest perpendicular tumor measurements) rate of Group I was significantly higher than that of Group II (33% vs. 14%; P < 0.05). Also, the 1-year survival rate of Group I (27%) was higher than that of Group II (9%) or Group III (0%) (P < 0.05 and P < 0.01, respectively). The median survival period of Group I was 19 weeks, which was significantly longer than that of Group II (11 weeks) or Group III (5 weeks) (P < 0.05 and P < 0.01, respectively). CONCLUSIONS: These results suggest that combined therapy consisting of intraarterial cisplatin infusion and systemic IFN-alpha may be useful as a palliative treatment for HCC patients with major vascular involvement or extrahepatic metastasis.

Expression of transforming growth factor beta-1 in chronic hepatitis and hepatocellular carcinoma associated with hepatitis C virus infection.

BACKGROUND: Transforming growth factor beta-1 (TGF beta 1) has been suggested to play a role in the development, growth or progression of hepatocellular carcinoma (HCC). Genotype and serum titer of HCV also affect the occurrence of HCC in chronic hepatitis C. In this study, we were to evaluate the effects of genotype or serum titer of HCV on the expression of TGF beta 1. We also intended to examine the correlation between the up-regulation of TGF beta 1 and the association with HCC in patients with chronic hepatitis C. METHODS: We studied 19 patients with chronic hepatitis C and 18 with HCC associated with HCV infection. HCV genotype was determined by line probe reverse hybridization assay and the amount of HCV-RNA was quantitated by branched DNA signal amplification assay. Serum TGF beta 1 level was measured by enzyme linked immunosorbent assay. RESULTS: HCV genotypes of patients with HCC were similar to those without it. Serum HCV-RNA titer was higher in genotype 1b than in non-1b (p < 0.05). Serum TGF beta 1 levels were higher in HCC than in chronic hepatitis (p < 0.05). However, there was no significant difference in the serum TGF beta 1 level between genotype 1b and non-1b. Also, it was not correlated with the serum HCV-RNA titer or alanine aminotransferase levels. CONCLUSION: TGF beta 1 seems to be overexpressed in HCC compared to that of chronic hepatitis C: it was not affected by serum ALT levels, genotype or serum HCV titer. It is suggested that TGF beta 1 may be associated with the malignant transformation of hepatocyte or the progression of HCV-associated HCC.