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放射線防護人材の不足が国内の政府機関でも議論されるようになって久しい。2018 年に行われた放射線防護に関連する学会の合同調査では、10 － 20 年前に比べ、放射線防護の専門家数は2 割減となっており、現リーダーと次世代リーダーの層が薄くなっていることが明らかとなった。 そこで、日本放射線安全管理学会、日本放射線影響学会、日本放射線事故・災害医学会、日本保健物理学会では、放射線防護関連人材の効果的な確保方策を検討するため、2019 年9 月1 日から10 月31 日の間、会員の専門分野や業務内容、バックグラウンドや就職の経緯等に関するWeb アンケートを合同で実施した。複数の学会に所属する会員は1 回限りの回答とし、371 名の回答が得られた。 調査の結果、放射線生物学（実験系）、放射線防護学・放射線安全管理学、放射線計測・線量評価を専門とする会員が多かった。原子力・放射線災害医療を専門とする会員は15％程度で、医師の比率が高い傾向が見られた。彼らの5 割は放射線研究歴がなく、典型的なキャリアとしては比較的多数の職場を経験した後、学生時代の研究とはほとんど関係のない教育や診療を主業務としていることが明らかになった。放射線防護や線量評価の専門家は多いものの、原子力・放射線災害医療も専門と回答した割合は1 割程度にとどまった。 調査の回答率から換算すると、緊急被ばく医療を専門とする医師および診療放射線技師有資格者は、放射線防護関連の学会内にそれぞれ60-70 名および20-30 名程度存在すると推定された。40 歳未満の会員の3 割が診療放射線技師有資格者であったことから、今後、災害時の放射線防護や線量評価を担う診療放射線技師が増えることが期待される。一方、緊急被ばく医療を専門とする医師の確保は、放射線防護関連の学術コミュニティ内だけでは難しく、放射線科や救急・災害医療関連の診療科からの参入が必要と思われる。

Serum autoantibodies respond not only to tumor-associated antigens of hepatocellular carcinoma (HCC) but also to those of liver cirrhosis (LC) and chronic hepatitis (CH). The present prospective multi-institutional study evaluated the diagnostic properties of six autoantibodies in distinguishing HCC from LC and CH. A total of 416 participants were enrolled: 149 With HCC, 76 with LC, 103 with CH and 88 healthy controls. Titers of serum autoantibodies to Sui1, RalA, p62, p53, c-myc and NY-ESO-1 were determined using enzyme-linked immunosorbent assays. All six antibodies were positive for HCC: s-Sui1-Abs (44%), s-RalA-Abs (23%), s-p62-Abs (21%), s-p53-Abs (13%), s-c-myc-Abs (11%) and s-NY-ESO-1-Abs (6%). The positivity rates of all six antibodies combined were 5% for healthy controls, 52% for CH, 58% for LC and 66% for HCC. The positivity rates of s-Sui1-Abs, s-RalA-Abs and s-p53-Abs were higher for HCC compared with those of LC and CH. However, the positivity rates of s-p62-Abs, s-c-myc-Abs and s-NY-ESO-1-Abs for HCC were not higher compared with those for LC and CH. Overall, autoantibodies were useful in differentiating patients with HCC from healthy individuals. However, they were not specific to HCC and were also present in the sera of individuals with CH and LC. These autoantibodies may be induced during the development of HCC. Clinical trial registration number: UMIN000014530 (date of registration 2011/07/11).

Background Conversion from sorafenib to regorafenib is primarily an evidence-based treatment strategy in patients with advanced hepatocellular carcinoma (HCC). This study aimed to assess the safety and efficacy of sequential therapy with sorafenib and regorafenib in patients with advanced HCC by analysis of outcomes in clinical practice with the aim to complement phase III findings. Methods The medical records of patients with advanced HCC receiving regorafenib were retrieved to collect data on sorafenib administration at seven Japanese institutions. Radiological responses and adverse events were evaluated using the Response Evaluation Criteria in Solid Tumors version 1.1 and the Common Terminology Criteria for Adverse Events version 4.0, respectively. Results Before March 2018, 44 patients were administered regorafenib for advanced HCC. The median sorafenib treatment duration was 8.4 months. The most common adverse events were similar to those reported by the RESORCE trial. The median overall survival (OS) was 17.3 months (95% confidence interval [CI] 11.4–22.9), and 17 of 37 patients (45.9%) discontinued regorafenib and received sequential systemic therapy after regorafenib. These patients had significantly longer OS than those who were treated by the best supportive care or sub-optimal therapy (not reached versus 8.7 months [95% CI 5.8–11.7]; P

Background: There is no standard posttreatment for patients with advanced hepatocellular carcinoma (HCC) in whom lenvatinib therapy has failed. This study aimed to investigate rates of migration to posttreatment after lenvatinib and to explore candidates for second-line agents in the patients with failed lenvatinib therapy. Methods: We retrospectively collected data on patients with advanced HCC who received lenvatinib as the first-line agent in 7 institutions. Results: Overall survival and progression-free survival (PFS) of 178 patients who received lenvatinib as the first-line agent were 13.3 months (95% confidence interval [CI], 11.5–15.2) and 6.7 months (95% CI, 5.6–7.8), respectively. Sixty-nine of 151 patients (45.7%) who discontinued lenvatinib moved on to posttreatment. The migration rates from lenvatinib to the second-line agent and from the second-line agent to the third-line agent were 41.7 and 44.4%, respectively. Based on multivariate analysis, response to lenvatinib (complete or partial response according to modified RECIST) and discontinuation of lenvatinib due to radiological progression, as well as male were associated with a significantly higher probability of migration to posttreatment after lenvatinib. On the other hand, alpha-fetoprotein levels of 400 ng/mL or higher was correlated with a significantly lower probability of migration to posttreatment after lenvatinib. Of 63 patients who received second-line systemic therapy, 53 (84.2%) were administered sorafenib. PFS, objective response rate (ORR), and disease control rate (DCR) for sorafenib treatment were 1.8 months (95% CI, 0.6–3.0), 1.8%, and 20.8%, respectively. According to the Cox regression hazard model, Child-Pugh class B significantly contributed to shorter PFS. PFS, ORR, and DCR of 22 patients who received regorafenib after lenvatinib in any lines were 3.2 months (range, 1.5–4.9 months), 13.6%, and 36.3%, respectively. Similarly, PFS, ORR, and DCR of 17 patients who received regorafenib after lenvatinib in the third-line (after sorafenib) were 3.8 months (range, 1.1–6.5 months), 17.6%, and 41.2%, respectively. Conclusion: Sorafenib may not be a candidate for use as a posttreatment agent after lenvatinib, according to the results of the present study. Regorafenib has the potential to become an appropriate posttreatment agent after lenvatinib.

Background: The present study aimed to assess the efficacy and safety of lenvatinib and verify the possibility of lenvatinib for the expanded indication from the REFLECT trial in patients with advanced hepatocellular carcinoma (HCC) in real-world practice, primarily focusing on the population that was excluded in the REFLECT trial. Methods: We retrospectively collected data on patients with advanced HCC who were administered lenvatinib in 7 institutions in Japan. Results: Of 152 advanced HCC patients, 95 and 57 patients received lenvatinib in first-line and second- or later-line systemic therapies, respectively. The median progression-free survival in Child-Pugh class A patients was nearly equal between first- and second- or later-line therapies (5.2 months; 95% CI 3.7–6.9 for first line, 4.8 months; 95% CI 3.8–5.9 for second or later line, p = 0.933). According to the modified Response Evaluation Criteria in Solid Tumors, the objective response rate of 27 patients (18%) who showed a high burden of intrahepatic lesions (i.e., main portal vein and/or bile duct invasion or 50% or higher liver occupation) at baseline radiological assessment was 41% and similar with that of other population. The present study included 20 patients (13%) with Child-Pugh class B. These patients observed high frequency rates of liver function-related adverse events due to lenvatinib. The 8-week dose intensity of lenvatinib had a strong correlation with liver function according to both the Child-Pugh and albumin – bilirubin scores. Conclusion: Lenvatinib had potential benefits for patients with advanced HCC with second- or later-line therapies and a high burden of intrahepatic lesions. Dose modification should be paid increased attention among patients with poor liver function, such as Child-Pugh class B patients.

Background Conversion from sorafenib to regorafenib is primarily an evidence-based treatment strategy in patients with advanced hepatocellular carcinoma (HCC). This study aimed to assess the safety and efficacy of sequential therapy with sorafenib and regorafenib in patients with advanced HCC by analysis of outcomes in clinical practice with the aim to complement phase III findings. Methods The medical records of patients with advanced HCC receiving regorafenib were retrieved to collect data on sorafenib administration at seven Japanese institutions. Radiological responses and adverse events were evaluated using the Response Evaluation Criteria in Solid Tumors version 1.1 and the Common Terminology Criteria for Adverse Events version 4.0, respectively. Results Before March 2018, 44 patients were administered regorafenib for advanced HCC. The median sorafenib treatment duration was 8.4 months. The most common adverse events were similar to those reported by the RESORCE trial. The median overall survival (OS) was 17.3 months (95% confidence interval [CI] 11.4-22.9), and 17 of 37 patients (45.9%) discontinued regorafenib and received sequential systemic therapy after regorafenib. These patients had significantly longer OS than those who were treated by the best supportive care or sub-optimal therapy (not reached versus 8.7 months [95% CI 5.8-11.7]; P 0.001). Conclusion The results based on Japanese clinical practices verified the tolerability of regorafenib in advanced HCC. Major regorafenib-associated adverse events were similar to those related to sorafenib. OS was significantly longer than expected, which might be associated with the sequential systemic therapies after regorafenib, mainly lenvatinib.

Background and aims Some follow-up studies of large regenerative nodules (LRNs) and dysplastic nodules (DNs) were reported previously. However, the pre-malignant potentiality of LRNs has remained controversial up to now. No LRNs showed malignant transformation in our previous study. We aimed to evaluate the pre-malignant potentiality of LRNs and DNs with a greater number of cases and longer follow-up periods. Methods From 1982 to 2005, 1,500 consecutive nodular lesions up to 2 cm in diameter were subjected to US guided thin-needle biopsy in cirrhotic patients at Chiba University Hospital. Of these lesions, 68 LRNs in 60 cases and 20 DNs in 22 cases were followed up for more than 6 months without any anti-cancer therapy. The last US examination was in 2010. The total study period was 28 years. We analyzed the histological findings and the clinical data of all cases retrospectively. The outcome of the lesions was examined. Results The mean follow-up period was 38.9 (16–119) months in LRNs and 31.9 (6–101 months) in DNs. Rate of nodule enlargement was higher in DNs (8/24 nodules, 33 %) than LRNs (11/68 nodules, 16 %), (p = 0.0743, not significant). Rate of malignant transformation was also higher in DNs (10/24 nodules, 42 %) than LRNs (9/68 nodules, 13 %), (p = 0.0040, significant). The rate of disappearance in images was similar between LRNs and DNs. Conclusions We should recognize LRN as low risk pre-malignant lesions whereas DNs as high risk lesions.

The radiation environment inside residential houses was measured at MinamiSoma-shi and Iitate-mura in Fukushima Prefecture. The average measured reduction coefficients, which are the ratios of the indoor and outdoor ambient-dose-equivalent rates were 0.35 and 0.45 at the centers of the first and second floors, respectively. The indoor dose rates on the second floors were larger than those on the first floors. The indoor dose rates increased with measurement height. The indoor and outdoor photon energy spectra were measured, revealing that the indoor scattered photon component is larger than the outdoor one.

Hepatitis A virus (HAV) is a causative agent of acute viral hepatitis for which an effective vaccine has been developed. Here we describe ultra-deep pyrosequences (UDPSs) of HAV 5'-untranslated region (5'UTR) among cases of the same outbreak, which arose from a single source, associated with a revolving sushi bar. We determined the reference sequence from HAV-derived clone from an attendant by the Sanger method. Sixteen UDPSs from this outbreak and one from another sporadic case were compared with this reference. Nucleotide errors yielded a UDPS error rate of < 1%. This study confirmed that nucleotide substitutions of this region are transition mutations in outbreak cases, that insertion was observed only in non-severe cases, and that these nucleotide substitutions were different from those of the sporadic case. Analysis of UDPSs detected low-prevalence HAV variations in 5'UTR, but no specific mutations associated with severity in these outbreak cases. To our surprise, HAV strains in this outbreak conserved HAV IRES sequence even if we performed analysis of UDPSs. UDPS analysis of HAV 5'UTR gave us no association between the disease severity of hepatitis A and HAV 5'UTR substitutions. It might be more interesting to perform ultra-deep sequencing of full length HAV genome in order to reveal possible unknown genomic determinants associated with disease severity. Further studies will be needed.

The biological dose of nuclear workers engaged in emergency response tasks at Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Station was estimated in the present study. As the national core center for radiation emergency medical preparedness in Japan, the National Institute of Radiological Sciences (NIRS) received all individuals who were suspected of being overexposed to acute radiation. In the course of health examinations at NIRS, biological dosimetry was performed by the dicentric chromosome assay (DCA). Twelve individuals were examined from 21 March-1 July 2011. The results indicated that the estimated exposure doses for all individuals were lower than 300 mGy, with the mean value of about 101 mGy. These results by DCA were in accordance with those obtained by physical dosimetry based on personal dosimeter recording assessment. The results corroborate the fact that no acute radiation syndrome was observed among the workers examined.

Aim: The number of hepatitis A cases in Japan as well as in other developed countries has been progressively decreasing during the last several years. There is no universal hepatitis A vaccination program in Japan, and a hepatitis A virus (HAV) epidemic in Japan is not unlikely. In 2011, a hepatitis A outbreak associated with a revolving sushi bar occurred in Chiba, Japan. We aimed to analyze this outbreak. Methods: Twenty-seven patients associated with this outbreak were admitted to the National Hospital Organization Chiba Medical Center. Molecular epidemiologic investigations were conducted. Results: Twenty-six of the 27 patients had gone to the same revolving sushi bar, and then clinical symptoms appeared. HAV RNA was detected by reverse transcription polymerase chain reaction in 23 of the 27 (85.1%) patients whose sera had tested positive for anti-HAV immunoglobulin M. All isolates from this outbreak were clustered within subgenotype IA, displaying 100% sequence homology with each other in 232 bp from all 23 patients. All isolates belong to the IA-1 sublineage, which is endemic to Japan. Conclusion: A revolving sushi bar was associated with a hepatitis A outbreak, and molecular epidemiological investigations proved useful.

Purpose The International Commission on Radiological Protection recommends removing the prostate before cremation if death occurs within 12 months after 125 I brachytherapy. However, the incidence of death within this time frame has not been robustly investigated in any country. The purpose this study was to investigate the incidence and cause of death and actions taken when death has occurred within 12 months after 125 I brachytherapy for prostate cancer in Japan. Methods and Materials Data were extracted from the Japan Radioisotope Association database to investigate the total number of implantation cases, number of early deaths after implantation, cause of death, and postmortem actions between September 2003 and the end of June 2010 in Japan. Early death was defined as occurring within 12 months after 125 I brachytherapy for prostate cancer. Results During the study period, 15,427 patients underwent 125 I brachytherapy and 43 (0.28%) died within 12 months after implantation. For 37 of the 43 patients (86%), the brachytherapy source was retrieved together with the prostate gland at autopsy; however, autopsy could not be performed in six (14%) of the deceased patients. The largest proportion of early deaths was because of cerebrovascular or cardiovascular disease (17/43, 40%), followed by malignant tumor (15/43, 35%), and respiratory disease or infection (7/43, 16%). Conclusions The incidence of early deaths within 12 months after 125 I brachytherapy in Japan was 0.28%. In almost all cases, the brachytherapy sources were removed in the intact prostate before the body was cremated and stored appropriately.

Among radiation-induced chromosome aberrations, multicentric chromosomes, as represented by dicentric chromosomes (dicentrics), are regarded as sensitive and specific biomarkers for assessing radiation dose in the 0 to 5 Gy range. The objective of this study was to characterize chromosome aberrations induced in vitro by a higher dose of radiation. Peripheral blood lymphocytes were exposed to 15 Gy gamma rays at a dose rate of 0.5 Gy/min and harvested at 48, 50, 52, 54, 56 and 72 h. The first mitotic peak appeared at 52-54 h, showing about a 6 h mitotic delay as compared with nonirradiated control cultures. Cell-cycle analysis of parallel and simultaneous cultures by sister-chromatid differentiation staining suggests that metaphase cells examined in 48-56 h cultures were in the first mitosis after culture initiation. The mean dicentric equivalent counts ranged from 9.0 to 9.3 in consecutively harvested cultures with no significant differences among them. At 72 h, about 20 % of dividing cells were tetraploid, persisting with faithfully replicated unstable chromosome aberrations. The nonrandom distribution of replicated chromosome pairs, deduced from multicolor fluorescence in situ hybridization analysis, led us to surmise that the predominant mechanism underlying the induction of tetraploid cells is endoreduplication. These findings suggest that a high-dose in vitro irradiation applied to peripheral blood lymphocytes may affect on the replication process, in addition to structural chromosome damage.

Cone-like acryl converters have been used for transforming the energy-distribution information of incident fast neutrons into the spatial-distribution information of recoil protons. The characteristics of neutron–proton conversion have been studied up to around 10 MeV by using an imaging plate (IP). A notable and interesting signal enhancement due to recoil protons generated in an acryl converter was observed on IP images for irradiation with a 252Cf source. Similar experiments were also performed in the radiation field of a research nuclear reactor and an accelerator-based neutron generator. A Monte Carlo calculation was carried out in order to understand the spatial distributions of the signal enhancement by recoil protons; these distributions promisingly involve the energy information of incident neutrons in principle. Consequently, it has been revealed that the neutron energy evaluation is surely possible by analyzing the spatial distributions of signal enhancement that is caused by recoil protons.

Atomic Energy Research Institute of Kinki University has devoted in the education of nuclear engineering using UTR-KINKI since its establishment in 1961. After the adoption of “Nuclear Energy Human Resources Development Program” by METI in 2007, the activities were facilitated fruitfully to the experience-based practices for the 9 universities. This paper introduces these activities firstly. We are mainly suffering from keeping enough machine time for the reactor practices. Even if they felt the interests in the practices, it is impossible to keep in touch with each student′s learning for their comprehensive curriculum after their participations of the practice. This paper describes a proposed systematic education, which is a combination of reactor practice and distance learning using Internet communication tools.

The scanning method with GM survey meter is useful for detection of surface radiological density. The detection ability is varied with several parameters; those are the distance between the sample and the window of GM tube, the scanning speed and the background dose rates. We made an experimental system. In that system, a radiation source can be moved at any constant velocity with a linear scanning device. The obtained data shows that the change of count rate has some patterns due to each scanning velocity. The count rate increased with the source coming closer, and decreased with the source moving away. The maximum count rate under the scanning condition, those are 5 mm distance and 50 mm/s scanning velocity, point source on a stainless steel plate was 23% of the count rate on the fixed source. The detection ability in various scanning conditions was evaluated from the measured data. As a result, it was confirmed to be able surely to detect the lower level of the surface radiological density limit by means of the scanning condition applied to the routine work, 5 mm distance and 50 mm/s scanning velocity.

核燃料物質に関連する国際的な管理の体制，特に，保障措置に絡む国内外の状況と対応についての歴史的経緯及び現状を整理した。また，天然/劣化ウラン300g，トリウム900g以下の，いわゆる少量の核燃料物質に焦点をあて，それらを使用する際の法的要件と手続きにおける留意事項をまとめ，そのような物質を使用する事業所がとるべき適切な対応について，東京大学の例を挙げつつ，教育プログラムの策定と実施に着目し，考察をした。

胆道出血は, 経皮経肝的穿刺手技において注意すべき合併症の一つで, 仮性動脈瘤の関与が指摘されている. 我々は, 自然消退への経過を示した経皮的肝生検後の胆道出血例を経験した. 本例の臨床経過において, カラードプラを用い, 仮性動脈瘤に対応すると考えられたカラーモザイク所見の推移を観察したので報告する. 症例は63歳, 女性, 自己免疫性肝硬変. 経皮的肝生検後に, 腹痛, 肝胆道系酵素の上昇と貧血の進行を認めた. カラードプラ法では, 肝右前区域にモザイク信号を呈する小瘤状部を認め, FFT波形解析にて高度の乱流所見を示していた (カラーモザイク). 肝生検施行部との対応から, 穿刺手技後の肝仮性動脈瘤と, それに伴った胆道出血が強く疑われた. 緊急入院後, 内視鏡的逆行性胆道造影検査にて胆道出血が確認されたため, 経鼻的胆道ドレナージを留置した. 経動脈的塞栓術の適応を考慮しつつ保存的に経過を見ていたが, その後は胆道出血を認めなかった. 肝生検2週後の超音波では, カラーモザイクは微弱化し, 乱流所見は軽減していた. さらに, 9日後の超音波では同所見は消失し, その後, 再発を見ていない. カラードプラ法におけるカラーモザイク所見は, 本症の診断, 経過観察に有用と考えられた.

To evaluate the therapeutic efficacy of percutaneous ethanol injection (PEI) for patients withor = 3 lesions of small (or = 3 cm diameter) hepatocellular carcinoma (HCC).PEI was applied to 270 patients with small HCC as the first-line treatment option during a 20-year period.(1) There was no treatment-related deaths, and only 2.2% of severe complications; (2) PEI induced a complete response of all HCCs according to CT evaluation performed within one month after the procedure, and the local recurrence rate at 3 years was 10%; (3) the overall 3- and 5-year survival rates after treatment were 81.6 and 60.3%, respectively, but the rates were higher, 87.3 and 78.3%, in Child A patients with a solitary tumoror = 2 cm in diameter; (4) factors significantly influencing survival were liver function (P = 0.0033) and serum alpha-fetoprotein level (P = 0.0014), and (5) the recurrence rate at remote sites in the liver was lower in patients with HCCor = 2 cm (P = 0.0395) and in those with a solitary HCC (P0.0001) according to Cox's proportional hazard model. (6) Radiofrequency ablation would not have been performed in approximately 25% of these patients.PEI is considered a reliable treatment for small HCC in terms of safety and efficacy.

Some of technologically enhanced naturally occurring radioactive material (TENORM), such as radon and monazite sand, gradually became a target for radiological protection. In order to regulate TENORM safely and economically, it is essential to consider the characteristics of TENORM such as ubiquity, huge volume, and very low activity levels. In this paper, radiation protection principles and standards for NORM/TENORM are summarized based on the reports published by the international organizations (e. g. ICRP and IAEA) to assist the development of national regulatory framework. The survey results on the present Japanese situations on industries related to NORM/TENORM are provided, and the categorization for NORM/TENORM, which is established by the Radiation Council of Japan, is explained how to control NORM/TENORM based on their exposure doses instead of their activity levels. Finally, basic processes to solve the problems related to NORM/TENORM are discussed.

We administered trientine hydrochloride, a drug used in the treatment of Wilson's disease, to patients with hepatocellular carcinoma after radical treatment with percutaneous ethanol injection or radiofrequency ablation, and examined its effect on the reduction of liver-tissue copper content. We enrolled 24 patients with 3 or fewer primary lesions of Child class A or B hepatocellular carcinoma with diameters of 3 cm or less who had undergone radical treatment with percutaneous ethanol injection or radiofrequency ablation. Trientine hydrochloride was orally administered in a single daily dose of 250 mg to 12 patients before a meal (at fasting, group 1) or at a total daily dosage of 750 mg, divided into 3 doses, to 12 patients (group 2). This study was a randomized between-groups comparative study of 12 weeks' duration. We used the particle-induced x-ray-emission method to determine liver-tissue mineral content. Urine copper and serum mineral levels were also measured, and transaminase levels were examined. Liver-tissue copper content decreased significantly, to 160.1 microg/g dry weight, after treatment, compared with the pretreatment level of 306.8 microg/g dry weight (P

Aim: To study whether cancer cell differentiation in small hepatocellular carcinoma (HCC) can be assessed by computed tomography (CT) and magnetic resonance (MR) imaging. Methods: We retrospectively evaluated the relationship between cancer cell differentiation in 127 HCC 3 cm or less in diameter (113 patients) and CT and MR images. Images were reviewed in a consensus conference by three authors (SA, TY, and ME). Histopathological diagnosis of HCC was made from liver specimens obtained by sonographically guided biopsy. Results: The degree of histological differentiation of cancer cells was significantly different between HCC that were isodense with liver parenchyma in both artery-dominant and equilibrium phases in contrast-enhanced CT and tumors that were hyperdense in the artery-dominant phase and iso- or hypodense in the equilibrium phase (P = 0.0054), as well as tumors that were iso- or hypodense artery-dominant and hypodense equilibrium (P = 0.0002). Histological differentiation of lesions that were hyperintense in T1-weighted images and hypointense in T2-weighted images differed significantly from those with the opposite MR characteristics (P = 0.0122). In T1-weighted fat-suppression images and T2-weighted images, respectively, the degree of histological differentiation was significant between the hypointense/hyperintense and the hyperintense/hypointense patterns (P

Background/Aims: The aim of this study was to investigate the relationship between trace metals and the prevalence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or hepatic cirrhosis caused by hepatitis C virus (HCV). Methods: We measured the contents of copper, iron, and zinc in HCC tissue (n = 112), dysplastic nodules (n = 7), and liver parenchyma in patients with (n = 112) and without (n = 12; 7 with grade F3 fibrosis, 5 with grade F4 fibrosis) HCC. Metals were quantified in thin-needle biopsy specimens using the particle-induced X-ray emission method (PIXE). Results: Copper level in liver parenchyma was higher in patients with HCC than in those without HCC (p < 0.01), while there was no such difference in hepatic iron. In patients with grade F4 fibrosis, copper content in the liver parenchyma was higher in the presence of HCC than in its absence (p < 0.05). Multiple regression analysis showed that the only factor significantly associated with the coexistence of HCC in HCV-positive patients with chronic liver disease was the copper level in the liver parenchyma. Conclusions: Hepatic copper overload may contribute to the development of HCC in HCV-positive patients with chronic hepatitis or cirrhosis.

The aim of this study was to determine the metabolizing activities in the liver of patients with hepatocellular carcinoma (HCC). Thin-layer chromatography autoradioluminography was used to measure metabolizing activities. Succinate-producing activity (SPA) was used as an indicator of metabolizing activity of the tricarboxylic acid (TCA) cycle in mitochondria, and diazepam-N-demethylating activity (DZ-DA), diazepam-3-hydroxylating activity (DZ-HA) and tolbutamide-methyl-hydroxylating activity (TB-HA) as indicators of drug metabolizing activities by P-450. SPA and drug-metabolizing activity of HepG2 cells were examined to compare with those of human liver specimens. Liver biopsy specimens of 30 patients and surgical specimens of eight patients with HCC were studied. SPA of HepG2 cells was as high as that of human tumor tissue, and DZ-DA, DZ-HA and TB-HA were undetectable in HepG2 cells. SPA and DZ-HA of non-tumor tissue in biopsy samples were significantly higher than those in resected liver specimens (P < 0.05). In biopsy specimens, SPA was significantly higher in tumor tissue than in non-tumor tissue (P < 0.05), and DZ-DA, DZ-HA and TB-HA were significantly lower in tumor tissue (P < 0.01). SPA was significantly higher in large tumors (≥30 mm) than in small tumors

Workers decommissioning the Fukushima-Daiichi nuclear power plant damaged from the Great East Japan Earthquake and resulting tsunami are at risk of injury with possible contamination from radioactive heavy atoms including actinides, such as plutonium. We propose a new methodology for on-site and rapid evaluation of heavy-atom contamination in wounds using a portable X-ray fluorescence (XRF) device. In the present study, stable lead was used as the model contaminant substitute for radioactive heavy atoms. First, the wound model was developed by placing a liquid blood phantom on an epoxy resin wound phantom contaminated with lead. Next, the correlation between the concentration of contaminant and the XRF peak intensity was formulated considering the thickness of blood exiting the wound. Methods to determine the minimum detection limit (MDL) of contaminants at any maximal equivalent dose to the wound by XRF measurement were also established. For example, in this system, at a maximal equivalent dose of 16.5 mSv to the wound and blood thickness of 0.5 mm, the MDL value for lead was 1.2 ppm (3.1 nmol). The radioactivity of 239Pu corresponding to 3.1 nmol is 1.7 kBq, which is lower than the radioactivity of 239Pu contaminating puncture wounds in previous severe accidents. In conclusion, the established methodology could be beneficial for future development of a method to evaluate plutonium contamination in wounds. Highlights: Methodology for evaluation of heavy-atom contamination in a wound was established. A portable X-ray fluorescence device enables on-site, rapid and direct evaluation. This method is expected to be used for evaluation of plutonium contamination in wounds.

The concentrations of 222Rn (radon) and its progeny with surrounding environmental gamma-dose rates were measured simultaneously inside and outside of buildings at 10 locations around Taipei and Hualien in Taiwan. For summer radon in Taiwan, indoor concentrations were estimated to be about 20 Bq m−3 with about 90 nSv h−1 of environmental gamma, and outdoors, about 10 Bq m−3 with about 70 nSv h−1. The equilibrium factors were calculated to be 0.2–0.3 indoors and 0.3–0.4 outdoors. Indoor radon concentration had a weak positive correlation with gamma-dose rate. Since there is a possibility that high radon concentrations exist indoors during the cool season in Taiwan because of extremely low ventilation rates in the dwellings, a winter survey in January through February will be needed for future estimation of the annual effective dose.

Background: Extracorporeal shock-wave lithotripsy (ESWL) is a treatment that preserves the gallbladder. Problems after ESWL treatment include stone recurrence and the development of biliary symptoms. Methods: Two hundred and sixty-two patients with cholesterol-type gallstones, the best indication for ESWL treatment, and 42 control patients with cholesterol-type gallstones who received no treatment entered this study. We evaluated the factors associated with recurrence of gallstones after stone clearance and the development of biliary symptoms after ESWL treatment. Results: The 3-, 5- and 7-year cumulative probabilities of gallstone recurrence were 20.6, 27.1 and 33.1%, respectively, with the recurrence probability significantly lower in patients with good gallbladder contractility. In patients with recurrence, ursodeoxycholic acid (UDCA) treatment was effective. In 69 patients with residual gallstones, the 3-, 5- and 7-year cumulative risks of biliary symptoms were 17.3, 24.9 and 30.5%, respectively. With residual gallstones, the risk of biliary symptoms developing was significantly lower in patients with a ≤ 3 mm fragment size at the end of ESWL treatment and in those treated consistently with UDCA for 6 months or more after treatment with ESWL. The risk of biliary symptoms was significantly lower in ESWL-treated patients with residual stones who had a ≤ 3 mm fragment size after treatment compared to those of control patients. Conclusions: Ursodeoxycholic acid was effective in clearing stones in patients with gallstone recurrence. In patients with residual stones, the fragmentation of stones to ≤ 3 mm and UDCA administration effectively reduced the risk of subsequent biliary symptoms.

Aims: This study evaluated the connection between the progression of hepatic fibrosis and trace metals, the distribution profiles of copper(Cu) and Zinc (Zn) and the generation of hydroxyl radicals from Cu- metallothionein (MT) purified from human hepatocellular carcinoma (HCC). Methods: We measured the metal contents in HCC tissue and liver parenchyma in patients with HCC. The content of metals in the liver was measured by particle induced X-ray emission (PIXE). Distribution profiles of Cu and Zn in human liver was evaluated by high-performance liquid chromatography (HPLC). The generation of hydroxyl radicals was measured by electron spin resonance (ESR) spin-trapping technique. Results: Hepatic copper content increased with the progression of hepatic fibrosis. Copper level in liver parenchyma was higher in patients with HCC than in those without HCC (p < 0.01). MT was mainly present as Zn-MT in normal liver, Cu,Zn-MT in surrounding liver parenchyma and Cu-MT in HCC (p < 0.01). The signal intensity of the ESR spectrum in HCC was stronger than those in normal liver and surrounding liver parenchyma. Conclusions: Copper accumulation in the liver parenchyma seems to relate to hepatocarcinogenesis.

In order to expand the available energy range of neutron dosimetry by the paired ionization chambers, an alternative method has been newly proposed. The method employs another TE–TE chamber with a gamma-ray attenuator instead of conventional C–CO2 chamber. A rough comparison of uncertainty estimates between conventional method and newly proposed one is carried out. The result indicates that the accuracy of the present method is far less-sensitive to the change of neutron energy and is evidently superior to that of the conventional method.

Background and Aims: Relationships between chronic liver disease and trace metals have not been clearly understood. To examine connections between severity of hepatic fibrosis in chronic hepatitis C and copper, iron and zinc we measured the contents of these metals in liver tissue and serum in the patients. Methods: Forty-one patients (26–62 years), 13 with fibrosis representing grade F1, 16 with F2, seven with F3, and five with F4, entered this study. Metals were quantified in needle liver-biopsy specimens by particle-induced X-ray emission. In serum, metals were measured by flameless atomic absorption spectrometry. Results: Hepatic copper content increased with progression of hepatic fibrosis (P < 0.05). The copper content correlated positively with bilirubin (r = 0.466, P = 0.0023), and with type IV collagen (r = 0.402, P = 0.0086) and correlated negatively with albumin (r = – 0.404, P = 0.080). However, hepatic iron and zinc contents did not show a significant differences between grades of fibrosis. Conclusions: Copper accumulation in fibrotic livers caused by chronic hepatitis C may contribute to hepatic injury. The real mechanism is not known at present, but excess copper may damage the liver by oxidative stress.

A measurement of neutron dose rate on iron-polyethylene shielding structure was carried out by 252Cf source. Simulated geometry was slit-like opening of polyethylene in iron slab and polyethylene slab shielding.These experiment was done at research facility of Hazama Co,. Iron slab and polyethylene slab thickness were 10 cm each. A gap of the polyethylene was simulated. Neutron REM-counter, polyethylene covered BF3 counter (STUDSVIK 2202-D), was used for measurement of streaming neutron dose equivalent. The solid state track detector (SSTD), allyl-diglycol-carbonate, were used for measurement of fast neutron dose equivalent in the range of 170Kev to 15Mev.The experimental data was obtained against gap width, source location and detector location.Obtained data shows strong correlation between dose rate and above parameters.These data was investigated in the view of to make use of actual facility design and compared with calculation such as MCNP4B.From the result of gap streaming experiment and calculation,...