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This paper does not necessarily reflect the views of the International Commission on Radiological Protection. What is at stake? It was one of the most frequently asked questions in a series of fora with concerned parties on the rehabilitation of living conditions in the aftermath of the accident at Fukushima Daiichi nuclear power plant. It was obvious that radioactive contamination was the source of the problem, and people were at a loss over how to cope with the situation. Various measures were taken under such circumstances, including detailed radiation monitoring, a decontamination programme to reduce the level of radiation in the living environment, and activities related to communication about radiation risk. Nevertheless, this question was asked repeatedly. Measures against radiation exposure were certainly necessary, but it is a reality that they were not enough to solve the difficulties experienced by people in the affected areas. This article presents the author's personal view of the underlying reasons for this, and discusses the way to facilitate recovery after a nuclear accident.

In 2007, a nationwide survey was conducted to determine the frequency of CT procedures in Japan in order to compare the current use of CT among developed countries. The frequency of adult and pediatric CT scans was estimated using a model based on the results of the survey. Survey questionnaires were sent to 2,266 CT facilities: 1,068 government hospitals and 1,198 other hospitals and non-hospital medical centers. The questionnaire requested information including the number of beds, outpatients per day, type of CT scanner, various body regions scanned, and the number of scans performed. The results of the study indicate that the number of CT procedures was closely correlated with the number of hospital beds. The authors estimate that approximately 20.5 million procedures were performed in 2005 and 21.2 million in 2006. The number of pediatric CT procedures was calculated by multiplying the total number of CT procedures by the estimated fraction of pediatric (0-15 y) CT procedures. Annual pediatric CT procedures were estimated to have been approximately 580,000 in 2005 and 600,000 in 2006. The present study indicates that the number of procedures per thousand of population, 166 for total CT and 32-34 for pediatric CT, is lower in Japan than in the U.S.

Multidrug resistance (MDR) seriously limits the efficacy of chemotherapy in patients with cancer and leukemia. Active transport across membranes is essential for such cellular drug resistance, largely provided by ATP-binding cassette (ABC) transport proteins. Intracellular drug sequestration contributes to MDR; however, a genuine intracellular ABC transport protein with MDR function has not yet been identified. Analyzing the intrinsic drug efflux capacity of leukemic stem cells, we found the ABC transporter A3 (ABCA3) to be expressed consistently in acute myeloid leukemia (AML) samples. Greater expression of ABCA3 is associated with unfavorable treatment outcome, and in vitro, elevated expression induces resistance toward a broad spectrum of cytostatic agents. ABCA3 remains localized within the limiting membranes of lysosomes and multivesicular bodies, in which cytostatics are efficiently sequestered. In addition to AML, we also detected ABCA3 in a panel of lymphohematopoietic tissues and transformed cell lines. In conclusion, we identified subcellular drug sequestration mediated by the genuinely intracellular ABCA3 as being a clinically relevant mechanism of intrinsic MDR.

Glimepiride, a third generation sulfonylurea (SU), is known to have extrapancreatic effects, but its vascular effect is unclear. We investigated the efficacy of glimepiride in improving arterial stiffness assessed by cardio-ankle vascular index (CAVI) in type 2 diabetic patients, compared with glibenclamide, a conventional SU.Forty type 2 diabetic patients were randomly assigned to two groups. One group was administered glimepiride 1.5 mg/day, and the other group was administered glibenclamide 1.25 mg/day for 6 months.No significant difference in hypoglycaemic effect was observed between two groups. CAVI significantly decreased only in glimepiride group (9.4 ± 1.4→8.9 ± 0.8, p0.05). Decrease in CAVI was greater in glimepiride group than in glibenclamide group (-0.50 ± 0.98 vs. -0.04 ± 0.57, p = 0.048). Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) decreased in glimepiride group and increased in glibenclamide group, and the changes were significantly different between groups (-1.5 ± 3.5 vs. + 1.8 ± 3.6, p = 0.009); whereas serum lipoprotein lipase mass increased in glibenclamide group and decreased in glibenclamide group, and the changes tended to be different between groups (+ 2.1 ± 19.1 vs. -7.4 ± 19.2, p = 0.096). Change in urinary 8-OHdG was a significant independent predictor for change in CAVI in all subjects.These results suggest that glimepiride improves CAVI compared with glibenclamide. Reduced oxidative stress and improved insulin resistance may contribute to the improvement of CAVI by glimerpiride.

Ovarian shielding allows ovarian recovery and normal birth in female hematopoietic SCT recipients undergoing TBI

The purpose of this study was to evaluate the possibility of preserving ovarian function by ovarian shielding to reduce the irradiation dose in total body irradiation (TBI). The subjects in the study were females aged less than 40 years, who were undergoing allogeneic hematopoietic stem cell transplantation using a TBI-based regimen and who desired to have children after transplantation. For ovarian shielding, abdominal computed tomography (CT) and skin marking were performed in both the supine and prone positions, prior to the TBI. A pair of columnar blocks was placed just above the patient's body. Thus far three patients have been treated. The serum estradiol level decreased to an undetectable level (

The ABCA3 gene, of the ABCA subclass of ATP-binding cassette (ABC) transporters, is expressed exclusively in lung. We report here the cloning, molecular characterization, and distribution of human ABCA3 in the lung. Immunoblot analysis using the specific antibody reveals a 150-kDa protein in the crude membrane fraction of human lung. Immunohistochemical analyses of alveoli show that ABCA3 is expressed only in the type II cells expressing surfactant protein A. At the ultrastructural level, ABCA3 immunoreactivity was detected mostly at the limiting membrane of the lamellar bodies. Since members of the ABCA transporter family are known to be involved in transmembrane transport of endogenous lipids, our findings suggest that ABCA3 plays an important role in the formation of pulmonary surfactant in type II cells.

To investigate how primary care physicians select appropriate diagnostic tests in their clinical practice, we analyzed the physician's decision making processes by means of written case simulations. We allocated the physicians who participated in this study to three groups; nine residents and ten attending physicians from the Department of Primary Care Medicine, and nine specialists from the Department of Medicine in our hospital. After they read a history and findings in each presented case, the physicians were requested (1) to make diagnostic hypotheses and predict probability of each hypothesis, (2) to select diagnostic tests and their purpose, and (3) to estimate contribution of the tests to the diagnosis. The results revealed that the attending physicians tended to order the diagnostic tests more strictly based on their hypotheses than the residents and specialists did. The attending physicians selected diagnostic tests from specific varieties rather than from "Essential Laboratory Tests" when they were confident in their hypotheses. On the other hand, they selected the tests mainly from "Essential laboratory Tests" when they were uncertain of diagnosis or needed to exclude serious diseases. They regarded the contribution of tests to the diagnosis as high when specific diagnostic tests were available for the presumptive diagnosis, or severe conditions were expected. These findings suggest that, in the setting of primary care practice, the application of laboratory tests depends on the severity of presenting conditions and pre-test certainty of the diagnostic hypothesis. Therefore, it may not be always appropriate to apply "Essential Laboratory Tests" uniformly to every patient irrespective of his/her condition.

Portopulmonary venous anastomosis is a potential channel for systemic arterial embolization during embolization procedures for bleeding esophageal varices. To document the presence of such anastomoses, 15 patients with esophageal varices were studied by real-time contrast echocardiography combined with transhepatic cineportography. Cinefluorographic technique, which was applied for this purpose, occasionally failed to demonstrate the dynamic events in the left atrium because of rapid dilution of contrast medium. Echocardiography after the injection of dextrose solution into the gastric coronary vein allowed two-dimensional real-time images of contrast echoes in the left cardiac chambers. By combining these two methods, more reliable diagnostic information was obtained in five of the 15 patients studied.

We used magnetic resonance imaging (MRI) at 0.2 T and angiography to evaluate hepatocellular carcinoma (HCC) in 43 patients who had not received therapy. Tumor detection rate by MRI was 84%, T2-weighted spin echo imaging being the best detection method, though one case could only be detected by T1-weighted imaging (Inversion Recovery method). The signal intensity of the tumor relative to the surrounding liver parenchyma was studied using MRI, and tumor staining using angiography. Where there was a high signal intensity in the T2-weighted spin echo images there was a corresponding tendency for tumor staining to be marked. MRI demonstrated the inner structure--which resembles random high-intensity threads on a lower-intensity background--of hypervascular tumors. Tumors with capsules appeared with the capsule clearly delineated irrespective of the signal intensity of the tumor itself.

The magnetic resonance imaging of gallstones was studied in 34 patients. Diagnosis of the gallstones using magnetic resonance imaging was possible in 29 patients (85%). The gallstones showed as no-signal areas in all cases, with relatively strong signals being detected from the center of the stones in six cases. Postoperative studies showed the stones with the central signals to be of the so-called mixed stone type, in which the central area consists of cholesterol with a radiating structure. The central signal was thought to originate in water that accumulates in the central cavity of the stone, the cavity not being isolated from the exterior of the stone and there being a passage of fluids. The central signal is a characteristic indication of the stone's structure.

A case of liver cirrhosis with large portacaval shunt from the superior mesenteric vein is reported. The portal blood flow was diagnosed as reversed on admission, but normalized with treatment. Blood flow was measured noninvasively and repeatedly using an ultrasonic Doppler duplex system. The reversed portal flow led to the superior mesenteric vein, right (and some left) internal inguinal vein, and inferior vena cava. This rare collateral pathway was clearly demonstrated by percutaneous transhepatic portalgraphy. A link between shunt and an appendectomy carried out 22 yr ago is considered, and the possibility of the temporarily reversed portal blood flow on admission being due to deteriorated hepatic hemodynamic conditions is discussed.

In order to clarify the natural transmission route of human T-cell leukemia virus type I (HTLV-I) from mother to child, we have followed two groups of children with ages of 1 to 3 years who were nourished either with HTLV-I-infected breast milk, or with non-infected milk from sero-positive, HTLV-I carrier mothers. Tests for the presence of antibody against HTLV-I revealed that 4 of 6 children in the former group developed HTLV-I infection, while only 1 of 14 children in the latter group became infected. The difference in HTLV-I infection rate for the children in the two groups was statistically significant (P less than 0.01 by chi-square). Furthermore, 2 of 4 elder siblings in the former group developed HTLV-I infection, whereas only one of 8 elder siblings in the latter group became infected. The overall rate of HTLV-I infection of breast-fed children born to HTLV-I-carrier mothers was 25% (8/32) by 3 years of age. Five of 6 mothers with HTLV-I-infected cells in the milk also possessed infected cells in their peripheral blood. Conversely 5 of 6 mothers without infected cells in the peripheral blood possessed no infected cells in their breast milk, suggesting that HTLV-I-infected cells in the peripheral blood can enter the breast milk. None of the 8 breast-fed children born to carrier mothers whose peripheral blood and breast milk-borne cells were negative, developed HTLV-I infection, suggesting that HTLV-I transmission from mother to child is dependent upon the number of HTLV-I-infected cells in carrier mothers.

Blood flow directions of the portal trunk, splenic vein, and superior mesenteric vein were studied using an ultrasonic Doppler duplex system in 146 healthy adults, 132 patients with liver cirrhosis, 76 with hepatocellular carcinoma, 32 with idiopathic portal hypertension, 134 with chronic hepatitis, 18 with acute hepatitis, and 142 with other diseases. Spontaneous hepatofugal flow in one or more of the three vessels examined was detected in 14 patients. Spontaneous hepatofugal flow in the portal trunk was detected in three patients with liver cirrhosis. In two of these three patients, the hepatofugal flow in the portal trunk disappeared after medication. This is interesting, since hepatofugal flow may, in fact, be more common than we suspected in patients who, because of the severity of their disease, are not able to undergo invasive examination. Postoperative hepatofugal flow in the portal system was detected in 20 of 71 cases: 15/17 patients after interposition mesocaval shunting, 2/17 after distal splenorenal shunting, 2/31 after splenectomy, and 1/6 after splenic artery occlusion with steel coils. In more than half the cases of interposition mesocaval shunting (9/17 patients), blood flow in the portal trunk was hepatofugal. However, hepatopetal blood flow in the portal trunk was maintained in most cases of distal splenorenal shunting (13/17), showing the merits of this technique as a selective portosystemic shunt operation.

Using an ultrasonic Doppler duplex system, we investigated the portal hemodynamics of two patients with portal thrombosis after splenectomy and esophageal transection for portal hypertension accompanied by liver cirrhosis. In both cases, the preoperative blood flow volumes of the splenic and portal veins were especially high, but were markedly lower--even than normal--after the operation. However, the results of pre- and postoperative peripheral platelet counts and coagulation function tests did not differ remarkably. The dramatic change in portal hemodynamics caused by the splenectomy was thought to be the main factor in the formation of the portal thrombi.