Determining a methodology of dosimetric quality assurance for commercially available accelerator-based boron neutron capture therapy system

The irradiation field of boron neutron capture therapy (BNCT) consists of multiple dose components including thermal, epithermal and fast neutron, and gamma. The objective of this work was to establish a methodology of dosimetric quality assurance (QA), using the most standard and reliable measurement methods, and to determine tolerance level for each QA measurement for a commercially available accelerator-based BNCT system. In order to establish a system of dosimetric QA suitable for BNCT, the following steps were taken. First, standard measurement points based on tissue-administered doses in BNCT for brain tumors were defined, and clinical tolerances of dosimetric QA measurements were derived from the contribution to total tissue relative biological effectiveness factor-weighted dose for each dose component. Next, a QA program was proposed based on TG-142 and TG-198, and confirmed that it could be assessed whether constancy of each dose component was assured within the limits of tolerances or not by measurements of the proposed QA program. Finally, the validity of the BNCT QA program as an evaluation system was confirmed in a demonstration experiment for long-term measurement over 1 year. These results offer an easy, reliable QA method that is clinically applicable with dosimetric validity for the mixed irradiation field of accelerator-based BNCT.     

A 13-week subchronic toxicity study of dietary administered saponin-rich and isoflavones-containing soybean extract in F344 rats

A subchronic toxicity study of soybean extract was performed in F344 rats with dietary administration at concentrations of 0%, 1.25%, 2.5% and 5% for 13 weeks. No mortality or abnormal clinical signs in any group were observed. Body weight gains were decreased with a tendency for reduction of feed intake in the 1.25% and above female and 5% male groups. In males, absolute and relative liver weights were increased in the 1.25% and above groups. In females relative kidney weights were increased in the 1.25% and above groups. Other significant changes such as decreased RBC and hematocrit and increased urea nitrogen were detected in the 2.5% and/or 5% groups. On histopathological observation, atrophy of the ventral prostate was observed in all animals in the 5% male group. Mucification and atrophy of the vaginal epithelium and increased atretic follicles in ovaries were noted in 2.5% and 5% female rats. Based on the above findings the lowest-observed-adverse-effect level for male and female rats was estimated to be 1.25% (707.2 and 751.8 mg/kg b.w./day, respectively).     

Alteration of Leukocyte–Endothelial Cell Interaction During Aging in Retinal Microcirculation of Hypertensive Rats

Purpose Hypertension, one of the more common chronic diseases affecting the elderly, has been reported to influence leukocyte–endothelial cell interaction. The leukocyte-mediated inflammatory process contributes to age-related changes in vessels. This study was designed to evaluate age-related changes in leukocyte–endothelial cell interaction in the hypertensive rat retina. Methods Male spontaneous hypertensive rats (SHR; 1.5, 3, 6, 12, and 20 months of age) and age-matched Wistar-Kyoto rats (WKY) were used. The number of accumulated leukocytes was counted in sections of flat-mounted retinal tissue. The expression of intercellular adhesion molecule-1 (ICAM-1) and CD18 (the common β-chain of ICAM-1 ligands) was evaluated. Retinal thickness was evaluated histologically. Results The number of accumulated leukocytes and the expression of ICAM-1 and CD18 increased in the aged retina. The number of leukocytes that accumulated and the expression of CD 18 were significantly higher in the SHR group than in the WKY group (P < 0.01). In addition, retinal thickness decreased with age. Conclusion Leukocyte–endothelial cell interaction increased in the aged retina and these changes were more severe in SHR retina than in WKY retina. This increased interaction was first observed at 3 months, a relatively young age.     

Acute promyelocytic leukemia: an unusual cause showing prolonged disseminated intravascular coagulation after placental abruption

Background Disseminated intravascular coagulation (DIC) caused by placental abruption usually improves rapidly after prompt delivery and adequate anti-DIC treatment. Case A 30-year-old nulliparous woman suffered from placental abruption at the 25th week of pregnancy, and emergent cesarean section was done immediately. She exhibited DIC, which continued even after termination of the pregnancy and anti-DIC treatment. She also showed neutropenia. We closely observed her, and at the 58th day postpartum, blast cells appeared in the peripheral blood and she was diagnosed with acute promyelocytic leukemia (APL). Induction chemotherapy was done successfully. The close observation after delivery enabled us to make the prompt diagnosis/treatment, leading to the complete remission. Conclusion APL should be added to the list of differential diagnosis when DIC persists even after prompt delivery and appropriate anti-DIC treatment after placental abruption.     

Prevention of surgical adhesions with gelatine sealing sheet in a canine adhesion model

Open in a separate window OBJECTIVESAlthough reoperation has been increasingly performed in cardiovascular surgery in recent years, preventing surgical adhesions remains an unsolved complication. Therefore, this study aimed to investigate whether gelatine sealing sheets are more effective than fibrin sealing sheets in preventing surgical adhesions.METHODSBilateral femoral arteries of 20 beagle dogs under general anaesthesia were pricked with syringe needles, and gelatine and fibrin sealing sheets were applied on the bleeding points to make canine adhesion models. The femoral artery was harvested after 4 and 12 weeks to evaluate adhesion formations. The adhesive grade was quantified by scoring the area and strength of adhesion tissues. Histological staining was performed to examine the structural features of surgical adhesions.RESULTSSignificantly fewer macroscopic adhesions were observed with gelatine sealing sheets than those with fibrin sealing sheets at 4 and 12 weeks postoperatively. Microscopically, CD3+ T lymphocytes at 4 and 12 weeks postoperatively in gelatine sealing sheets were significantly lower than those in fibrin sealing sheets. Microvessel density determined by CD34 at 4 and 12 weeks postoperatively in gelatine sealing sheets was also significantly lower than those in fibrin sealing sheets.CONCLUSIONSThe gelatine sealing sheets are more effective than the fibrin sealing sheets in preventing surgical adhesions. These findings suggest that the gelatine sealing sheet may help prevent adhesions and thus be a therapeutically effective biomaterial in vascular surgery.     

Influence of Altered Knee Angle on Electromyographic Activity of Hamstring Muscles Between Nordic Hamstring Exercise and Nordic Hamstring Exercise with Incline Slope Lower Leg Board

BackgroundPrevious studies have shown that performing the Nordic hamstring exercise (NHE) with different board slope angles can affect hamstring activation. However, changes in muscle length with different board slopes can alter joint angles leading to the moment arm (MA) at the knee changing during the NHE.PurposeThis study aimed to investigate the influence of changing muscle length on hamstring electromyographic activity during an isometric NHE, while maintaining an equal moment arm.Study DesignA crossover study designMethodsSixteen male volunteers performed two types of conventional NHE, one with knees on the floor (NHE) and one with the legs placed upon an incline slope of a lower leg board (NHEB). To compare between the conventional and inclined NHE, the moment arm at the knee was calculated to be equal by an examiner holding the lower legs at points marked at 77% and 94% of the length of the lower leg. The four sub-groups comprised of: 1) NHE-77%, 2) NHE-94%, 3) NHEB-77%, and 4) NHEB-94%. The hamstring EMG activity was measured at the biceps femoris long head (BFlh) and at the semitendinosus (ST) and related compensatory muscles. The RMS data were normalized as a percentage of the maximum isometric values (normalized EMG [nEMG]). Significant main effects findings were followed up with Tukey’s post-hoc test using SPSS software and statistical significance was set at the p < 0.05 level.ResultsThe BFlh EMG activity values for NHE-77% were significantly higher than those for NHE-94% (p= 0.036) and NHEB-77% (p < 0.001), respectively, while ST during NHE-77% was significantly higher only in NHEB-77% (p < 0.001). In addition, NHEB-94% was significantly greater than NHEB-77% for both BFlh (p < 0.001) and ST (p < 0.001).ConclusionThese results indicate that hamstring electromyographic activity is decreased when the hamstring muscle is lengthened during the Nordic hamstring exercise.Level of Evidence3     

New therapeutic approach for impaired arteriogenesis in diabetic mouse hindlimb ischemia.

BACKGROUND: The combined treatment of sustained-release basic fibroblast growth factor (Sr-bFGF) and a 5-hydroxytryptamine(2A) blocker, sarpogrelate, was evaluated to see whether it reversed the impaired collateral circulation in diabetic (DM) mouse hindlimb ischemia. METHOD AND RESULTS: Diabetic and normal mice with ischemic hindlimb were randomly assigned to 1 of 5 experimental groups (no treatment, sarpogrelate 50 mg . kg(-1) . day(-1), 20 microg or 50 microg Sr-bFGF and a combined treatment of 20 microg Sr-bFGF and sarpogrelate), and treated for 4 weeks. Tissue blood perfusion (TBP), vascular density (angiogenesis) and the number of mature vessels (arteriogenesis) were checked by the use of standard methods. Although angiogenesis was comparable (161+/-14 vs 154+/-12 vessels/mm(2)), the laser Doppler perfusion image index (LDPII) (0.43+/-0.11 (SD) vs 0.63+/-0.08, p<0.05) and arteriogenesis (8+/-3 vs 12+/-4 vessels/mm(2), p<0.05) were significantly lower in DM mice than those in normal mice. The dose of Sr-bFGF for the sufficient number of mature vessels (>or=45 vessels/mm(2)) and LDPII (>or=0.9) was 20 microg for the normal mice, and 50 microg for the DM mice, which was reduced with the aid of sarpogrelate. Conclusions A combined therapy of Sr-bFGF and sarpogrelate is effective for neovascularization to reverse the impaired arteriogenesis and TBP in DM mice.