Accurate gamma-ray dose measurement up to 10 MeV by glass dosimeter with a sensitivity control filter for BNCT.

Glass dosimeters are very useful and convenient detection elements in radiation dosimetry. In this study, this glass dosimeter was applied to a BNCT treatment field. Boron Neutron Capture Therapy (BNCT) is a next-generation radiation therapy that can selectively kill only cancer cells. In the BNCT treatment field, both neutrons and secondary gamma-rays are generated. In other words, it is a mixed radiation field of neutrons and gamma-rays. We thus proposed a novel method to measure only gamma-ray dose in the mixed field using two RPLGD (Radiophoto-luminescence Glass Dosimeter) and two sensitivity control filters in order to control the dose response of the filtered RPLGD to be proportional to the air kerma coefficients, even if the gamma-ray energy spectrum is unknown. As the filter material iron was selected, and it was finally confirmed that reproduction of the air kerma coefficients was excellent within an error of 5.3% in the entire energy range up to 10 MeV. In order to validate this method, irradiation experiments were carried out using standard gamma-ray sources. As the result, the measured doses were in acceptably good agreement with the theoretical calculation results by PHITS. In the irradiation experiment with a volume source in a nuclear fuel storage room, the measured dose rates showed larger compared with survey meter values. In conclusion, the results of the standard sources showed the feasibility of this method, however for the volume source the dependence of the gamma-ray incident angle on the dosimeter was found to be not neglected. In the next step, it will be necessary to design a thinner filter in order to suppress the effect of the incident angle.

Experimental study on Compton camera for boron neutron capture therapy applications.

Boron neutron capture therapy (BNCT) is a high-dose-intensive radiation therapy that has gained popularity due to advancements in accelerator neutron sources. To determine the dose for BNCT, it is necessary to know the difficult-to-determine boron concentration and neutron fluence. To estimate this dose, we propose a method of measuring the prompt γ-rays (PGs) from the boron neutron capture reaction (BNCR) using a Compton camera. We performed a fundamental experiment to verify basic imaging performance and the ability to discern the PGs from 511 keV annihilation γ-rays. A Si/CdTe Compton camera was used to image the BNCR and showed an energy peak of 478 keV PGs, separate from the annihilation γ-ray peak. The Compton camera could visualize the boron target with low neutron intensity and high boron concentration. This study experimentally confirms the ability of Si/CdTe Compton cameras to image BNCRs.

Response control of RPLGD for gamma-ray dose measurement using lead filters for BNCT.

Boron Neutron Capture Therapy (BNCT) is a cell-selective radiotherapy using a neutron capture reaction of 10B. In recent years, Accelerator Based Neutron Sources (ABNS) are under development instead of nuclear reactors for the next-generation neutron irradiation system for BNCT. However, ABNS as well as nuclear reactor usually generates unavoidable secondary gamma-rays by neutron-nuclear reactions such as capture reaction. In this research, we aimed to develop a separate measurement method of only gamma-rays in a mixed field of neutrons and gamma-rays using a fluorescent glass dosimeter (RPLGD), because most dosimeters have sensitivity to both radiation types. For this purpose, we proposed a lead filter method using two RPLGDs and lead filters. However, this method has a problem that the sensitivity to low energy gamma-rays (∼100 keV) is very small. In order to improve the sensitivity to low energy gamma-rays, we devised a method using a specially shaped lead filter. From theoretical calculations, we have shown that it was possible to estimate the air dose rate of the field where the gamma-ray energy spectrum shape was known for energies up to 10 MeV. In addition, we produced the specially shaped lead filter and experimentally confirmed the validity of the lead filter method using several gamma-ray standard sources and by measurements in a nuclear fuel storage room.

Assessment of facial symmetry by three-dimensional stereophotogrammetry after mandibular reconstruction: A comparison with subjective assessment.

INTRODUCTION: The assessment of facial symmetry, after mandibular reconstruction, currently relies on subjective esthetic assessment by an evaluator. The present study aimed to compare conventional subjective assessment with quantitative evaluation by three-dimensional (3D) stereophotogrammetry of facial cosmetic symmetry. METHODS: This retrospective study enrolled 20 patients who underwent mandibular reconstruction with free fibula flap after segmental resection between 2014 and 2018. Subjective assessments were performed by seven clinicians at 6-12 months after surgery. Simultaneously, lower face symmetry was measured by 3D stereophotogrammetry with the VECTRA H1 system and recorded as the root mean square deviation (RMSD). Data from the subjective and quantitative evaluations were compared using Spearman's rank correlation coefficient. RESULTS: The results showed that subjective assessments were strongly and negatively correlated with RMSD (P=0.00000128). This confirmed that RMSD, obtained by 3D stereophotogrammetry, reflected the subjective assessment of symmetry in our cohort. CONCLUSIONS: Three-dimensional stereophotogrammetry of facial cosmetic symmetry will be an available quantitative method for patients with head and neck cancer after mandibular reconstruction.

Mock-up experiment at Birmingham University for BNCT project of Osaka University--Neutron flux measurement with gold foil.

Mock-up experiment for development of accelerator based neutron source for Osaka University BNCT project was carried out at Birmingham University, UK. In this paper, spatial distribution of neutron flux intensity was evaluated by foil activation method. Validity of the design code system was confirmed by comparing measured gold foil activities with calculations. As a result, it was found that the epi-thermal neutron beam was well collimated by our neutron moderator assembly. Also, the design accuracy was evaluated to have less than 20% error.

A feasibility design study on a neutron spectrometer for BNCT with liquid moderator.

Neutrons generated by accelerators have various energy spectra. However, only limited methods are available to measure the whole neutron energy spectrum, especially when including the epithermal region that is normally used in BNCT. In the present study, we carried out the design study on a new neutron spectrometer that can measure such a neutron spectrum more accurately, precisely and with higher energy resolution, using an unfolding technique and a liquid moderator.

Prognostic factors influencing clinical outcome of allogeneic hematopoietic stem cell transplantation following imatinib-based therapy in BCR-ABL-positive ALL.

We investigated prognostic factors for the clinical outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) following imatinib-based therapy. Among 100 adult patients who were prospectively enrolled in the JALSG Ph+ALL202 study, 97 patients obtained complete remission (CR) by imatinib-combined chemotherapy, among whom 60 underwent allo-HSCT in their first CR. The probabilities of overall survival (OS) and disease-free survival (DFS) at 3 years after HSCT were 64% (95% CI, 49-76) and 58% (95% CI, 43-70), respectively. Prognostic factor analysis revealed that the major BCR-ABL transcript was the only unfavorable predictor for OS and DFS after HSCT by both univariate (HR, 3.67 (95% CI 1.49-9.08); P=0.005 and HR, 6.25 (95% CI, 1.88-20.8); P=0.003, respectively) and multivariate analyses (HR, 3.20 (95% CI, 1.21-8.50); P=0.019 and HR, 6.92 (95% CI, 2.09-22.9); P=0.002, respectively). Minimal residual disease status at the time of HSCT had a significant influence on relapse rate (P=0.015). Further study of the BCR-ABL subtype for the clinical impact on outcome of allo-HSCT in Ph+ALL is warranted.

[Surgical treatment for aortic root dilatation and aortic regurgitation after arterial switch operation].

Aortic regurgitation (AR) and, aortic root dilatation are serious problems occurring after arterial switch operation (ASO). We have experienced a case of 12-year-old boy with aortic root dilatation and AR after ASO. Consistent progression of AR and aortic root dilatation were observed during the follow-up period. The latest Z-score of Valsalva sinus was about 9. We performed the Bentall procedure instead of aortic valve-sparing operation because of the degenerative aortic valve and the excessive aortic root dilatation. The postoperative course was uneventful. Histopathological findings of the aortic wall showed degeneration of elastic fibers on both sides of the anastmosis.

[Emergency off-pump coronary artery bypass grafting for a nonagenarian with acute myocardial infarction; report of a case].

A 92-year-old man was presented with chest pain in home clinic. And he was transferred to our hospital for emergent operation of the acute myocardial infarction. Emergent coronary angiography (CAG) revealed the occlusion of left main trunk (LMT) and 2 vessels disorder. The patent was indicated of an emergency off-pump cardiac artery bypass graft (OPCAB). Our patient had a favorable post-operative course without severe complications, and discharged on post-operative day 23. It is difficult to standarlize the cardiac operation technique and indication of advanced elderly patients. In spite of lower safety margin of nonagenarians, we have to reevaluate the indication considering with physical defect, post-operative quality of life (QOL), the will of patients and their families themselves.

Increased serum levels and expression of S100A8/A9 complex in infiltrated neutrophils in atherosclerotic plaque of unstable angina.

BACKGROUND: The S100A8/A9 complex is expressed in a subset of activated neutrophils and macrophages in acute inflammatory lesions associated with various diseases. OBJECTIVE: To investigate (a) whether serum S100A8/A9 levels are increased in patients with unstable angina (UA); and (b) whether S100A8/A9 expression is upregulated in coronary atherosclerotic plaques of patients with UA. DESIGN: Serum S100A8/A9 levels in 39 patients with stable angina (SA) and 53 patients with UA were measured. In addition, the presence of the S100A8/A9 complex in directional coronary atherectomy specimens was studied immunohistochemically. Cell types which stain positive for S100A8/A9 were identified by immunodouble staining with neutrophils and macrophages. RESULTS: Mean (SD) serum S100A8/A9 levels were significantly higher in patients with UA than in those with SA (3.25 (3.08) microg/ml vs 0.77 (0.31) microg/ml, p<0.05). In patients with UA, immunodouble staining clearly showed that the S100A8/A9 complex was expressed in infiltrated neutrophils and occasional macrophages. The S100A8/A9-positive area was significantly higher in UA than in SA (mean (SD) 18.3 (14.2)% vs 1.3 (2.4)%, respectively, p<0.001). CONCLUSIONS: The S100A8/A9 complex may be involved in the inflammatory process of coronary atherosclerotic plaques in patients with UA.

Egg yolk protein and egg yolk phosvitin inhibit calcium, magnesium, and iron absorptions in rats.

Egg yolk decreases the absorption of iron. The effects of egg yolk protein and egg yolk phosvitin on the absorption of calcium, magnesium, and iron were investigated by in vivo studies. Male Wistar rats were fed purified diets containing casein, soy protein, or egg yolk protein for 14 d. The apparent absorptions of calcium, magnesium, and iron in the rats fed the yolk protein-based diet were lower than those in rats fed the casein- and soy protein-based diets. The apparent phosphorus absorption and the apparent protein digestibility in the yolk protein group were lower than those in the casein and soy protein groups. In the feces of the yolk protein group, serine comprised more than 30% of the amino acids. The addition of egg yolk phosvitin to the casein diets at levels of 1% and 2% (w/w) produced effects on calcium and magnesium absorptions similar to those produced by the diet containing yolk protein. The tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) pattern suggested that phosphopeptide fragments having molecular masses of 28, 22, and 15 kDa were evident in the contents of the small intestine of the rats fed phosvitin diets. These results indicate that yolk protein, when compared with casein and soy protein, decreases calcium and magnesium absorption via the resistance of phosvitin to proteolytic action.

Acute interstitial pneumonitis during chemotherapy for haematological malignancy.

Fourteen adult patients with haematological malignancies (eight non-Hodgkin's lymphoma, one multiple myeloma, one chronic lymphocytic leukaemia, two acute lymphoblastic leukaemia and two acute myeloid leukaemia) developed acute interstitial pneumonitis (IP) during the course of chemotherapy. All patients manifested high fever over 38 degrees C, bilateral diffuse pulmonary interstitial infiltrates in the chest radiograph and severe hypoxia without hypercapnia in the arterial blood gas analysis. Pathogenic microorganisms were not detected in repeated examinations in any patient. Chemotherapy given included various anti-neoplastic drugs. Five patients had received granulocyte colony-stimulating factor (G-CSF) for chemotherapy-induced leucopenia. The onset was associated with an increase of leucocytes in 10 patients. All patients were treated with high dose steroid hormone and broad spectrum antibiotics with or without anti-fungal agents, and three required mechanical ventilation. Eleven patients quickly recovered from these situations, whereas three died. Autopsies were done in two patients and disclosed pneumocystis carinii (PC) pneumonitis in one and non-specific pulmonary congestive oedema and fibrosis in the other. In conclusion, IP of unknown cause could develop in patients with various haematological malignancies especially at the recovery phase of chemotherapy-induced leucopenia irrespective of the previous G-CSF administration. High dose steroid hormone should be used as therapy for such patients as soon as possible after exclusion of an infective aetiology.

[Chronic traumatic aneurysm of the thoracic aorta; report of a case].

We report a rare case of chronic traumatic aneurysm of the thoracic aorta. A 23-year-old man flew down from the fifth floor of his apartment for an attempted suicide. He suffered right subdural hematoma, bilateral hemothorax, lung contusions, and many other traumas. He was paralyzed by the fracture and dislocation of the first lumbar vertebra. Posterior fixation of lumbar vertebra and the segmental resection of the jejum were performed on the first and third day, respectively. He recovered well; however, he complained his nocturnal dyspnea on the forty-fifth day. Detailed examinations showed that bilateral bronchi were compressed by the aneurysm of thoracic aorta. Elective operation was performed on the sixty third day. Psudoaneurysm, 5 cm in diameter, was disclosed in the aortic isthmus. Graft replacement was undergone with the cardiopulmonary bypass. His postoperative course was uneventful, and he was transferred for the rehabilitation of his paralysis on the eigty-eighth day.

A theory of electrical conductivity of molten salt. II.

In molten equivalent salts, a unified relation that the ratio of partial dc conductivities is always equal to the inverse mass ratio, viz. sigma(+)/sigma(-)=m(-)/m(+), has been confirmed in view of microscopic point starting from the generalized Langevin equation. It has been newly proved that the memory functions assumed to be an exponentially decaying form in the Langevin equation for cation and anion are equal to each other. Furthermore, the short time behaviors of moving ions are analyzed in terms of their velocity correlation functions, according to the combination of generalized Langevin equation and damped Einstein oscillator equation. A minor correction for the expression of common friction constant derived before has been given. Estimated results for conductivities are close to those obtained by computer simulation and also comparable to experimental values.

A single administration of interleukin-4 antagonistic mutant DNA inhibits allergic airway inflammation in a mouse model of asthma.

Interleukin 4 (IL-4) is essential for the switching of B cells to IgE antibody production and for the maturation of T helper (Th) cells toward the Th2 phenotype. These mechanisms are thought to play a crucial role in the pathogenesis of the allergic airway inflammation observed in asthma. In the present study, we examined the anti-inflammatory effects of DNA administration of murine IL-4 mutant Q116D/Y119D (IL-4 double mutant, IL-4DM), which binds to the IL-4 receptor alpha and is an antagonist for IL-4. Immunization of BALB/c mice with alum-adsorbed ovalbumin (OVA) followed by aspiration with aerosolized OVA resulted in the development of allergic airway inflammation. A single administration of IL-4DM DNA before the aerosolized OVA challenge protected the mice from the subsequent induction of allergic airway inflammation. Serum IgE level and extent of eosinophil infiltration in bronchoalveolar lavage (BAL) from IL-4DM DNA-administered mice were significantly lower than those in BAL from control plasmid-immunized mice. In our study, IL-4 or IL-4 mutants were not detected in sera from mice that had received a single administration of IL-4DM DNA. The results of this study provide evidence for the potential utility of IL-4 mutant antagonist DNA inoculation as an approach to gene therapy for asthma.

Superior survival of blood and marrow stem cell recipients given maternal grafts over recipients given paternal grafts.

During the reproductive period, mothers and offspring exchange hematopoietic cells and develop a form of immunological tolerance bidirectionally. To examine whether previous experience of such communication has any remote effect when maternal hematopoietic cells are later transplanted to the children, we retrospectively compared the outcomes of blood and marrow stem cell transplantation from maternal donors (n = 46) to those from paternal donors (n = 50) by using the database of the Japanese nationwide surveys for adult hematopoietic cell transplants between 1990 and 1998. At 5 years, recipients of maternal hematopoietic cells had a significantly higher overall survival than patients receiving paternal grafts (60% vs 32%, P = 0.006). Although no significant difference was observed in the occurrence of severe acute GVHD (grade > or =III) and the relapse of malignant diseases between two groups, the probability of non-relapse treatment-related mortality was significantly lower after maternal donor transplants. Furthermore, multivariate analysis revealed that parental donor type was the only factor significantly associated with overall survival. In conclusion, our analysis indicates superior survival of maternally donated recipients in hematopoietic stem-cell transplantations from biological parents. This finding has important implications in the selection of alternative familial donors, and warrants further prospective analysis of parental donor transplantations.

Right atrial myxoma associated with atrial septal defect: a case report and review of the literature.

We describe a case of right atrial myxoma with mild cyanosis due to a right-to-left shunt at the atrial level. The patient was a 31-year-old woman with a 10-month history of easy fatigability and shortness of breath. Echocardiography showed a right atrial tumor producing a partial dynamic tricuspid obstruction. Digital subtraction angiography via the superior vena cava disclosed a mass lesion which occupied the right atrium with early visualization of the ascending aorta. Successful excision of the tumor and repair of the atrial septal defect totally relieved her presenting symptoms. In a rare association of a right atrial myxoma with atrial septal defect, preoperative evaluation and operative management are discussed.