A study on the scattering exposure dose in radiotherapy.

現代の医療のなかで癌治療において不可欠な存在となった放射線治療｡一方,放射線被曝はたとえわずかであってもリスクが伴い,厳しく規制されている｡ただし医療被曝はこの限りになく,過去においては癌患者に放射線治療をおこなう際の患部以外の被曝についてはあまり問題視されなかった｡これには癌の治療という前提に加え,長期生存の可能性が低く,存命中に晩発障害が発生することが低いと考えられていたからである｡しかし,集学的治療が確立した今後の放射線治療においては完治する放射線治療患者が多くなり,治癒後の余命が長くなることが予測される｡放射線被曝による確率的影響は閾値がなく,影響は当然現れるであろう｡そこで,放射線治療をおこなう際の患者の散乱線被曝線量,治療室内散乱線量,さらに高エネルギー放射線発生装置を取り扱うときに問題となっている中性子を測定した｡その結果,測定線量は治療患部外被曝,室内散乱線量ともに無視できない量であることがわかった｡中性子については,人体に影響がある線量は検出されなかったが,中性子の存在は室内物品の放射化の可能性を示唆するもので定期的な測定管理が必要である｡また,Ⅹ線撮影室用の防護衣による散乱線被曝の低減効果は放射線治療室では無意味であった｡In modern medicine, radiotherapy has proved indispensable in the treatment of cancer. However. radiation exposure is a health hazard. and is thus strictly regulated. In the past, incidental exposure was not considered to pose a considerable risk, and because radiotherapy was an effective treatment for cancer and because the possibility of the long-term survival was generally poor, the prevalence of radiation injury was thought to be low. In recent years, however, more patients are making complete recoveries, and it is believed that long-term survival is possible with future radiotherapy techniques. There is no threshold for the stochastic effects of radiation exposure, and thus such effects may be detected even at low levels. In the present study, we measured the radiation exposure due to scattered rays from the patient, incidental radiation levels in the radiotherapy room, and levels of neutron radiation. which is a problem when high-energy X-ray radiotherapy systems are used. The results showed that exposure due to scattered rays and incidental levels in the radiotherapy room cannot be dismissed. and that further investigation is warranted. As for neutron radiation, dosages were below those that are known to influence the human body, but regular measurement is necessary because it may induce radioactivity in otherwise benign equipment. In addition, a protective apron had no effect on the exposure due to scattered rays in the radiotherapy room

Analysis of Tempormandibular Joint by Image Processing -Discrimination of Condylar Position-

Tomography is clinically useful in the diagnosis of the temporomandibular joint (TMJ) syndrome. The TMJ is formed by the condyle and the glenoid fossa, and there exists TMJ space between them. Image processing was employed in the present study, and the reference points of the condyle and the glenoid fossa were determined from the tomogram. Subsequently, the TMJ space was measured automatically in the image analysis. The TMJs of 98 patients were examined practically and the characteristics of each result were studied. There is a possibility of discriminating an abnormal condylar position from a normal one by making use of the TMJ space and the distance between two reference points

A multi-ethnic meta-analysis identifies novel genes, including ACSL5, associated with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating progressive motor neuron disease that affects people of all ethnicities. Approximately 90% of ALS cases are sporadic and thought to have multifactorial pathogenesis. To understand the genetics of sporadic ALS, we conducted a genome-wide association study using 1,173 sporadic ALS cases and 8,925 controls in a Japanese population. A combined meta-analysis of our Japanese cohort with individuals of European ancestry revealed a significant association at the ACSL5 locus (top SNP p = 2.97 × 10−8). We validated the association with ACSL5 in a replication study with a Chinese population and an independent Japanese population (1941 ALS cases, 3821 controls; top SNP p = 1.82 × 10−4). In the combined meta-analysis, the intronic ACSL5 SNP rs3736947 showed the strongest association (p = 7.81 × 10−11). Using a gene-based analysis of the full multi-ethnic dataset, we uncovered additional genes significantly associated with ALS: ERGIC1, RAPGEF5, FNBP1, and ATXN3. These results advance our understanding of the genetic basis of sporadic ALS

Association of mast cell-derived VEGF and proteases in dengue shock syndrome

Background: Recent in-vitro studies have suggested that mast cells are involved in Dengue virus infection. To clarify the role of mast cells in the development of clinical Dengue fever, we compared the plasma levels of several mast cell-derived mediators (vascular endothelial cell growth factor [VEGF], soluble VEGF receptors [sVEGFRs], tryptase, and chymase) and -related cytokines (IL-4, -9, and -17) between patients with differing severity of Dengue fever and healthy controls. Methodology/Principal Findings: The study was performed at Children\u27s Hospital No. 2, Ho Chi Minh City, and Vinh Long Province Hospital, Vietnam from 2002 to 2005. Study patients included 103 with Dengue fever (DF), Dengue hemorrhagic fever (DHF), and Dengue shock syndrome (DSS), as diagnosed by the World Health Organization criteria. There were 189 healthy subjects, and 19 febrile illness patients of the same Kinh ethnicity. The levels of mast cell-derived mediators and -related cytokines in plasma were measured by ELISA. VEGF and sVEGFR-1 levels were significantly increased in DHF and DSS compared with those of DF and controls, whereas sVEGFR-2 levels were significantly decreased in DHF and DSS. Significant increases in tryptase and chymase levels, which were accompanied by high IL-9 and -17 concentrations, were detected in DHF and DSS patients. By day 4 of admission, VEGF, sVEGFRs, and proteases levels had returned to similar levels as DF and controls. In-vitro VEGF production by mast cells was examined in KU812 and HMC-1 cells, and was found to be highest when the cells were inoculated with Dengue virus and human Dengue virus-immune serum in the presence of IL-9. Conclusions: As mast cells are an important source of VEGF, tryptase, and chymase, our findings suggest that mast cell activation and mast cell-derived mediators participate in the development of DHF. The two proteases, particularly chymase, might serve as good predictive markers of Dengue disease severity

NON-INVASIVE METHOD FOR PREDICTING HEPATOCELLULAR CARCINOMA IN PATIENTS WITH CHRONIC HEPATIC DISEASE BY MEASURING THE SHEAR WAVE VELOCITY

Aim : To evaluate the usefulness of acoustic radiation force impulse (ARFI) in predicting hepatocellularcarcinoma (HCC) in patients with chronic hepatic disease (CHD).Methods : A total of 230 patients participated in this study. They were subsequently classifiedinto the “HCC group” and the “non-HCC group”. We measured their liver stiffness and calculatedthe mean shear wave velocity (SWV) using ARFI.Results : The mean SWV was significantly higher in the HCC group than in the non-HCCgroup. The cut-off value for the mean SWV with the best discrimination between the two groupswas 1.36 (m/s). The area under the receiver operating characteristic curve (AUROC) was0.807. The AUROCs of the aspartate-aminotransferase-to-platelet ratio and Fibrosis 4 scorewere 0.780, 0.728, respectively. The independent risk factors of HCC included the mean SWVand age. A further analysis, based on the individual causes of CHD, found that among the HCVand non-HBV and non-HCV (nBnC) cases, the mean SWV was significantly higher in the HCCgroup than in the non-HCC group.Conclusion : Measuring the SWV using ARFI was a reliable method for predicting HCC in CHDpatients, especially in HCV and nBnC patients

ACOUSTIC RADIATION FORCE IMPULSE ELASTOGRAPHY FOR THE DIFFERENTIAL DIAGNOSIS OF LIVER TUMORS IN PATIENTS WITH LIVER DYSFUNCTION

Objective : Acoustic radiation force impulse (ARFI) technology can measure the elasticity of tissueand tumor. The aim of this study was to evaluate whether the ARFI technology can differentiatecavernous hemangioma, hepatocellular carcinoma (HCC) and metastatic liver tumors inpatients with liver dysfunction.Materials and Methods : Forty patients with liver dysfunction and liver tumors were enrolledin the study. The shear wave velocities (SWVs) in the tumors and background liver were examinedby ARFI elastography under ultrasonography (US).Results : The SWVs in livers bearing HCCs were significantly higher than those of livers bearingcavernous hemangiomas. The SWVs in HCCs and metastatic liver tumors were significantlyhigher than those in cavernous hemangiomas. The SWVs in metastatic liver tumors were significantlyhigher than those in HCCs. The SWV ratio of metastatic liver tumor/parenchyma wassignificantly higher than that of cavernous hemangioma/parenchyma and HCC/parenchyma.There was a significant correlation between the tumor sizes and the SWVs in metastaticliver tumors.Conclusions : We herein demonstrated that ARFI elastography could noninvasively provide helpfulinformation, without the need for biopsy, that could be used for the differential diagnosis amongcavernous hemangiomas, HCCs and metastatic liver tumors in patients with liver dysfunction