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81.
82.
In three-dimensional irradiation with pencil beam scanning, an extra dose is inevitably delivered to the irradiated site due to the finite reaction times of the beam delivery system, and it causes a severe distortion of the dose distribution in the target region. Since the amount of the extra dose is proportional to the beam intensity, the dose uniformity deteriorates as the beam intensity is increased in order to shorten the treatment time. In order to overcome this problem and shorten the treatment time, we have developed an optimization method in which the extra dose is integrated into the optimization process of the best weighting matrix. The effectiveness and applicability of the optimization method for spot and raster scanning irradiation were confirmed with computer simulations and also confirmed using irradiation experiments for spot scanning irradiation. The treatment time could be shortened to about one sixth of the time needed without taking the extra dose into account while obtaining the same degree of dose homogeneity in the target volume. A typical treatment time with the proposed method is about 15 s for the irradiation of a spherical target with an 80 mm diameter at 3 GyE. 相似文献
83.
Inaniwa T Kohno T Yamagata F Tomitani T Sato S Kanazawa M Kanai T Urakabe E 《Medical physics》2007,34(5):1684-1692
In proton therapy, it is important to evaluate the field irradiated with protons and the deposited dose distribution in a patient's body. Positron emitters generated through fragmentation reactions of target nuclei can be used for this purpose. By detecting the annihilation gamma rays from the positron emitters, the annihilation gamma ray distribution can be obtained which has information about the quantities essential to proton therapy. In this study, we performed irradiation experiments with mono-energetic proton beams of 160 MeV and the spread-out Bragg peak beams to three kinds of targets. The annihilation events were detected with a positron camera for 500 s after the irradiation and the annihilation gamma ray distributions were obtained. In order to evaluate the range and the position of distal and proximal edges of the SOBP, the maximum likelihood estimation (MLE) method was applied to the detected distributions. The evaluated values with the MLE method were compared with those estimated from the measured dose distributions. As a result, the ranges were determined with the difference between the MLE range and the experimental range less than 1.0 mm for all targets. For the SOBP beams, the positions of distal edges were determined with the difference less than 1.0 mm. On the other hand, the difference amounted to 7.9 mm for proximal edges. 相似文献
84.
OBJECTIVES: To elucidate variations of latent membrane protein 1 (LMP1) in Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) and explore the LMP1 variations of neighboring countries, China and Japan. METHODS: In 12 and 8 EBVaGCs from eastern China and Japan, respectively, the C-termini of LMP1 were analyzed using PCR and sequencing. The sequences were compared with previously published strains and were characterized on a phylogenetic tree. The difference between Chinese and Japanese isolates was characterized. RESULTS: Ten of 12 Chinese GC isolates (83.3%) and all of the 8 (100%) Japanese GC isolates belonged to the China 1 strain. Also, B95-8 type isolates were found in 2 of 12 Chinese GC. In the 18 China 1 type isolates, additional mutations outside the signature sequence changes were found. All Japanese isolates (100%) had two or more additional mutations, whereas only 5 of 10 (50%) Chinese isolates had two or more additional mutations. The difference was statistically significant (p = 0.0359). CONCLUSIONS: China 1 is the dominant strain in GC from eastern China and Japan. The similarity to that of nasopharyngeal carcinoma (NPC) from China supports the view that China 1 strain represents a geographic-associated polymorphism rather than an NPC-associated polymorphism. Japanese isolates show more mutations than Chinese isolates, suggesting a geographic difference between Chinese and Japanese isolates in GC. 相似文献
85.
Keita Itatsu Gen Sugawara Yuji Kaneoka Takehito Kato Eiji Takeuchi Michio Kanai Hiroshi Hasegawa Toshiyuki Arai Yukihiro Yokoyama Masato Nagino 《Surgery today》2014,44(7):1242-1252
Purpose
An incisional surgical site infection (I-SSI) is a frequently observed complication following colorectal surgery. Intraoperative wound management is one of the most important factors that determine the incidence of postoperative I-SSI. The purpose of this study was to assess the impact of the methods used for intraoperative wound management on the incidence of I-SSI following elective surgery for colorectal cancer.Methods
Between November 2009 and February 2011, the data of 1,980 consecutive patients who underwent elective colorectal resection for colorectal cancer were prospectively collected from 19 affiliated hospitals. The incidence of and risk factors for I-SSI were investigated.Results
Overall, 233 I-SSIs were identified (11.7 %). Forty-two possible risk factors were analyzed. Using a multivariate analysis, the independent risk factors for I-SSI were identified to be a high body mass index, previous laparotomy, chronic liver disease, wound length, contaminated wound class, creation or closure of an ostomy, right hemicolectomy procedure, the suture material used for fascial closure and the incidence of organ/space SSI.Conclusion
To prevent I-SSI following elective colorectal surgery, it is crucial to avoid making large incisions and reduce fecal contamination whenever possible. A high quality randomized control trial is necessary to confirm the definitive intraoperative procedure(s) that can minimize the incidence of I-SSI. 相似文献86.
87.
Yasuhiro Hamatani Moritake Iguchi Michikazu Nakamura Ryo Ohtani Yugo Yamashita Daisuke Takagi Takashi Unoki Mitsuru Ishii Nobutoyo Masunaga Hisashi Ogawa Mio Hamatani Mitsuru Abe Masaharu Akao 《Heart and vessels》2016,31(7):1154-1161
Heart failure (HF) increases the risk of ischemic stroke. Data regarding the incidence and predictors of ischemic stroke during hospitalization for HF are limited. The study population of this retrospective cohort study consisted of patients with congestive HF, consecutively admitted to our center from October 2010 to April 2014. We excluded patients complicated with acute myocardial infarction, infective endocarditis, and takotsubo cardiomyopathy. We also excluded those with dialysis or mechanical circulatory support. We investigated the incidence of ischemic stroke during hospitalization for HF. Thereafter, we divided the patients without oral anticoagulants at admission into two groups: patients with ischemic stroke and those without it, and explored the predictors of ischemic stroke. A total of 558 patients (287 without atrial fibrillation (AF), 271 with AF) were enrolled. The mean age was 76.8 ± 12.3 years, and 244 patients (44 %) were female. The mean left-ventricular ejection fraction was 47.4 %. Oral anticoagulants were prescribed in 147 patients (8 without AF, 139 with AF). During hospitalization (median length 18 days), symptomatic ischemic stroke (excluding catheter-related) occurred in 15 patients (2.7 % of the total, 8 without AF, 7 with AF). Predictors significantly associated with increased risk of ischemic stroke in patients without oral anticoagulants were as follows; short-term increases in blood urea nitrogen after admission (at day 3; odds ratio (per 1 md/dl): 1.06, 95 % confidence interval (CI) 1.01–1.11, p = 0.02, and at day 7; odds ratio: 1.03, 95 % CI 1.00–1.07, p = 0.03, respectively), and previous stroke (odds ratio; 3.33, 95 % CI 1.01–11.00, p = 0.04). The incidence of ischemic stroke during hospitalization for HF was high, even in patients without AF. Previous stroke and short-term increases in blood urea nitrogen was significantly associated with the incidence of ischemic stroke. 相似文献
88.
Immunological evidence for the in vivo occurrence of a crosslinked complex of poly(ADP-ribosylated) histone H1. 下载免费PDF全文
M Wong Y Kanai M Miwa M Bustin M Smulson 《Proceedings of the National Academy of Sciences of the United States of America》1983,80(1):205-209
The poly(ADP-ribosylation) of histones, which occurs within a limited and functionally specific domain of chromatin, is a novel post-translational modification. However, in the past it has been difficult to study this process in living cells because the substrate of the reaction (NAD) does not permeate the plasma membrane. In the current study, antibodies specific for histone H1 and poly(ADP-ribose) were used to study the occurrence of poly(ADP-ribose)+ species of H1 in vivo. Perchloric acid-extracted proteins from synchronously growing HeLa cells were fractionated by electrophoresis and transferred to nitrocellulose, and the transferred moieties were allowed to react with the specific antibodies and then with 125I-labeled protein A. The results conclusively demonstrate the natural occurrence of poly(ADP-ribose)-crosslinked complexes of histone H1 (i.e., H1 dimer), at the S/G2 phase transition of the cell cycle. 相似文献
89.
Takahisa Koyama Shin Kariya Yasuharu Sato Yuka Gion Takaya Higaki Takenori Haruna Tazuko Fujiwara Akira Minoura Soshi Takao Yorihisa Orita Kengo Kanai Masami Taniguchi Kazunori Nishizaki Mitsuhiro Okano 《Allergology international》2019,68(2):216-224
Background
IgG4 production is regulated by type 2 (IL-4 and IL-13) and regulatory (IL-10) cytokines involved in the pathophysiology of chronic rhinosinusitis (CRS). We sought to determine the pathophysiological characteristics of IgG4-positive cells in sinonasal tissues in CRS, especially eosinophilic CRS (ECRS).Methods
IgG4-positive cells in uncinate tissues (UT) and nasal polyps (NP) were examined by immunohistochemistry. Associations between the number of IgG4-positive cells and clinicopathological factors were analyzed. Receiver operating characteristics (ROC) analysis was performed to determine the cut-off value of IgG4-positive cells in tissue that can predict the post-operative course.Results
IgG4 was mainly expressed in infiltrating plasma and plasmacytoid cells, and the number of IgG4-positive cells was significantly higher in NP, especially those from severe ECRS patients, than in UT. In CRS patients, the number of IgG4-positive cells significantly and positively correlated with blood and tissue eosinophilia, radiological severity, and serum level of total IgE. The number of infiltrating IgG4-positive cells was significantly higher in patients with a poor post-operative course (sustained sinus shadow 6 months after surgery) than in those with a good one. The number of IgG4-positive cells in NP could discriminate patients with a good or a poor post-operative course (area under the curve: 0.769). Also, 73.3% sensitivity and 82.5% specificity were achieved when the cut-off value was set at 17 cells/high-power field.Conclusions
Our results suggest that the local expression of IgG4 on cells may be used as a biomarker that reflects the pathophysiology of CRS, including the post-operative course. 相似文献90.
Takenori Haruna Shin Kariya Tazuko Fujiwara Takaya Higaki Seiichiro Makihara Kengo Kanai Rumi Fujiwara Satoshi Iwasaki Yoshihiro Noguchi Kazunori Nishizaki Mitsuhiro Okano 《Allergology international》2018,67(3):392-398