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排序方式: 共有485条查询结果,搜索用时 15 毫秒
1.
Dr. Yoshihiko Hayakawa Ph.D. Allan G. Farman B.D.S Ph.D. D.Sc. William C. Scarfe B.D.S M.S. Kinya Kuroyanagi D.D.S Ph.D. 《Oral Radiology》1996,12(1):11-18
The RVG-4 permits automatic exposure compensation (AEC). The purpose of this investigation was to determine the effects of
AEC on image contrast. Images were made either with or without a dental QA jaw phantom using a fixed image projection geometry.
Exposures were 6.3 through 27.3 μC/kg using an X-ray generator operated at 70 kVp. Region of interest pixel value distributions
were measured at tissue thicknesses in this phantom, and the average pixel values and signal-to-noise ratios (SNR) were calculated.
The use of AEC without an object in place resulted in a disproportionate relationship between pixel value and exposure with
a marked reduction in SNR. The use of AEC on under- and over-exposed images of the phantom simultaneously enhanced image contrast
and reduced SNR. Thus, AEC provides a convenient and quick method for achieving high-contrast images with sub-optimal exposures,
however, this could lead to inappropriate patient dosages if the function is used for over-exposed images. AEC reduces the
SNR and produces disproportionate pixel values relative to exposure. 相似文献
2.
Obuse C Yang H Nozaki N Goto S Okazaki T Yoda K 《Genes to cells : devoted to molecular & cellular mechanisms》2004,9(2):105-120
CENP-A, a centromere-specific histone H3, is conserved throughout eukaryotes, and formation of CENP-A chromatin defines the active centromere region. Here, we report the isolation of CENP-A chromatin from HeLa interphase nuclei by chromatin immunoprecipitation using anti-CENP-A monoclonal antibody, and systematic identification of its components by mass spectrometric analyses. The isolated chromatin contained CENP-B, CENP-C, CENP-H, CENP-I/hMis 6 and hMis 12 as well as CENP-A, suggesting that the isolated chromatin may represent the centromere complex (CEN-complex). Mass spectrometric analyses of the CEN-complex identified approximately 40 proteins, including the previously reported centromere proteins and the proteins of unknown function. In addition, we unexpectedly identified a series of proteins previously reported to be related to functions other than chromosome segregation, such as uvDDB-1, XAP8, hSNF2H, FACTp180, FACTp80/SSRP1, polycomb group proteins (BMI-1, RING1, RNF2, HPC3 and PHP2), KNL5 and racGAP. We found that uvDDB-1 was actually localized to the centromeric region throughout cell cycle, while BMI-1 was transiently co-localized with the centromeres in interphase. These results give us new insights into the architecture, dynamics and function of centromeric chromatin in interphase nuclei, which might reflect regulation of cell proliferation and differentiation. 相似文献
3.
Nobushige Yamashita Shiro Hoshida Kinya Otsu Naoyuki Taniguchi Tsunehiko Kuzuya Masatsugu Hori 《British journal of pharmacology》1999,128(2):412-418
1 We utilized a rat model of myocardial infarction to investigate whether cardioprotection by monophosphoryl lipid A (MLA) is provided in the early and late phases, as well as to determine whether this cardioprotection may be related to the activation of manganese superoxide dismutase (Mn-SOD), an intrinsic radical scavenger. 2 Pretreatment with MLA (0.5 or 1.0 mg kg-1, i.v.) 24 h prior to 20-min left coronary artery (LCA) occlusion and 48-h reperfusion significantly decreased the incidence of ventricular fibrillation (VF) during ischaemia, as well as infarct size. Pretreatment with lower concentrations of MLA, however, was ineffective. 3 When we examined the time course of MLA (0.5 mg kg-1)-induced cardioprotection, both infarct size and the incidence of VF were significantly reduced in rats pretreated with MLA 0.5 h and 24 h before occlusion. We observed no differences, however, 2 and 72 h after MLA treatment. 4 The activity of Mn-SOD paralleled the cardioprotective effects of MLA. Mn-SOD activity in the myocardium was significantly enhanced in rats pretreated with MLA (0.5 mg kg-1) 0.5 and 24 h before. Mn-SOD activity was not altered, however, in rats pretreated 2 or 72 h before. Lower MLA concentrations were not effective even 24 h after the treatment. 5 We conclude that MLA treatment induced a biphasic pattern of cardioprotection. The pattern of Mn-SOD activity suggests that this enzyme may play a major role in the acquisition of cardioprotection against ischaemia-reperfusion injury. 相似文献
4.
Akira Hoshio Kinya Shirota Norihito Sasaki Tetsuya Doi Yoshihiro Sawada Masaharu Fukuki Hiroyuki Miyakoda Hiroshi Kotake Hiroto Mashiba 《Clinical cardiology》1995,18(11):641-646
To investigate the relationship between plasma levels and coronary vasodilation after administration of isosorbide dinitrate (ISDN), the plasma concentration and diarneters of six segments of the left coronary artery were measured before and after sublingual (SL) ISDN (5 mg) and left intracoronary (IC) administration of ISDN (3 mg) in 12 patients. After SL-ISDN, the systolic aortic pressure decreased with no significant concomitant changes in heart rate or diastolic aortic pressure. After IC-ISDN, all hemodynamic parameters showed significant changes, and these were greater after IC-ISDN than those after SL-ISDN. The individual mean vasodilation of six segments induced by SL- and IC-ISDN, were 23± 9 and 35± 11% (p<0.01), respectively. Before SL-ISDN, ISDN was not detected in plasma. After SL- and IC-ISDN, however, the plasma values of the ISDN were 36.1± 53.3 and 101.5± 90.0 ng/ml (p<0.01), respectively. Thus, both coronary vasodilative responses and plasma ISDN levels after IC-ISDN were significantly greater than those after SL-ISDN. However, neither the individual mean coronary vasodilation nor the hemodynamic changes correlated significantly with plasma ISDN levels. Consequently, with administration of the same dose, the coronary vasodilative response to ISDN did not correlate with plasma levels. Furthermore, IC-ISDN dilates coronary arteries more effectively than SL-ISDN. 相似文献
5.
Hiroyuki Koga Kenji Suzuki Kinya Nishimura Manabu Okawada Takashi Doi Geoffrey J. Lane Eiichi Inada Tadaharu Okazaki Atsuyuki Yamataka 《Pediatric surgery international》2014,30(9):937-940
Accurate division and sealing of lung parenchyma particularly in cases of total or near total incomplete fissure are crucial for preventing air leakage following thoracoscopic pulmonary lobectomy (TPL). However, conventional endoscopic stapling devices cannot be used during TPL in small children because of limited space. Consequently, Ligasure (LS) and Enseal (ES) devices are being used instead. We are the first to compare LS and ES for efficacy and efficiency during TPL. Of 26 TPL (6 upper, 3 middle, and 17 lower) performed for congenital adenomatoid malformation (n = 16) and sequestration (n = 10), incomplete fissure was found in 14. TPL (LS = 11; ES = 15) was performed conventionally in the lateral decubitus position with single lung ventilation using four 5 mm trocars. All cases had a chest tube inserted intraoperatively that was left in situ. Patient demographics, location of pathology, incidence of incomplete fissure, mean age/weight at TPL, mean blood loss, and mean operative time were all similar. However, duration of chest tube insertion was significantly shorter in ES because there was less postoperative air leakage (1.3 vs. 3.9 days; p < 0.05). ES would appear to seal lung parenchyma more effectively during TPL based on the shorter duration of chest tube insertion. 相似文献
6.
Akira Igarashi Yasuhiro Ebihara Tomoaki Kumagai Hiroyuki Hirai Kinya Nagata Kohichiro Tsuji 《Allergology international》2018,67(2):234-242
Background
Several methods have been developed to detect allergen-specific IgE in sera. The passive IgE sensitization assay using human IgE receptor-expressing rat cell line RBL-2H3 is a powerful tool to detect biologically active allergen-specific IgE in serum samples. However, one disadvantage is that RBL-2H3 cells are vulnerable to high concentrations of human sera. Only a few human cultured cell lines are easily applicable to the passive IgE sensitization assay. However, the use of human induced pluripotent stem cells (iPSCs) to generate human mast cells (MCs) has not yet been reported.Methods
The nuclear factor-kappa B (NF-κB)-responsive luciferase reporter gene was stably introduced into a human iPSC line 201B7, and the transfectants were induced to differentiate into MCs (iPSC-MCs). The iPSC-MCs were sensitized overnight with sera from subjects who were allergic to cedar pollen, ragweed pollen, mites, or house dust, and then stimulated with an extract of corresponding allergens. Activation of iPSC-MCs was evaluated by β-hexosaminidase release, histamine release, or luciferase intensity.Results
iPSCs-MCs stably expressed high-affinity IgE receptor and functionally responded to various allergens when sensitized with human sera from relevant allergic subjects. This passive IgE sensitization system, which we termed the induced mast cell activation test (iMAT), worked well even with undiluted human sera.Conclusions
iMAT may serve as a novel determining system for IgE/allergens in the clinical and research settings. 相似文献7.
Sakae Nagaoka Takafumi Yoshida Junji Akiyoshi Jun Akiba Takuji Torimura Hisashi Adachi Junichi Kurogi Nobuyoshi Tajiri Kinya Inoue Takashi Niizeki Hironori Koga Tsutomu Imaizumi Masamichi Kojiro Michio Sata 《Liver international》2007,27(8):1091-1097
BACKGROUND/AIMS: C-reactive protein (CRP) was recently identified as a prognostic factor for patients with hepatocellular carcinoma (HCC) after surgical resection. We investigated the relationship between the serum levels of high sensitivity CRP (H-CRP) and the prognosis of HCC patients. METHOD: We conducted a cohort study of 90 HCC patients enrolled from 1997 to 1998. All patients were treated and followed for a mean period of 3.2 years. Clinical variables were compared between patients positive for H-CRP (serum H-CRP levels >/=3.0 mg/L, n=47) and those negative for H-CRP (serum H-CRP levels <3.0 mg/L, n=43). We also determined the relationship between serum H-CRP and prognosis in HCC patients. RESULTS: The survival rate of patients of the H-CRP-positive group was lower than that of H-CRP-negative patients. Tumour stage (stages 3 or 4), total bilirubin >/=1.2 mg/dL, albumin (Alb) <3.5 g/dL, des-gamma-carboxy prothrombin >/=40 mAU/mL, positive H-CRP and initial treatment (transcatheter arterial chemoembolization, hepatic arterial infusion chemotherapy or best supportive care) were identified as significant poor prognostic factors by univariate analysis, while positive H-CRP [hazard ratio (HR), 1.58; P=0.048], Alb<3.5 g/dL (HR, 2.10; P=0.004), tumour stage (stages 3 or 4; HR, 3.05; P=0.001) and initial treatment (HR, 1.88; P=0.029) were considered to be significant determinants of poor prognosis by multivariate Cox proportional hazards analysis. CONCLUSIONS: The prognosis of H-CRP-positive patients was poorer compared with H-CRP-negative patients. This study confirmed that H-CRP, like CRP, is a marker of poor prognosis in HCC patients. 相似文献
8.
Kentaro Nakamura Keisuke Hagihara Naoko Nagai Ryuichiro Egashira Mariko Takeuchi Mai Nakano Hitomi Saito Misaki Moriguchi Satoko Tonari Satoshi Watanabe Akimitsu Miyake Kinya Ashida 《Nutrients》2022,14(6)
Ketogenic diets, which are carbohydrate-restricted high-fat diets, may have therapeutic effects on various diseases, including cancer. However, ketogenic diets are often not standardized and, therefore, results are difficult to interpret. We previously investigated the usefulness of ketogenic diets in cancer therapy, where ketogenic formulas (KF) were used as supplements to enhance blood ketone bodies; however, the amount of KF was determined empirically with reference to blood ketone bodies levels. Here, to determine a standardized optimal amount of KF, we investigated temporal changes in blood ketone bodies (acetoacetic acid (AcAc), β-hydroxybutyrate (BHB)) and safety in 20 healthy individuals when KF was taken repeatedly under the conditions of a ketogenic diet (UMIN000034216). The diurnal variation in total ketone bodies, and AcAc and BHB levels significantly increased after lunch and after dinner, on the 4th day of KF administration. There were no significant safety issues related to KF in the context of anthropometric, metabolic, nutritional, urological and gastrointestinal parameters. In addition, ketogenic diets lead to changes in gut microbiota. KF showed a decrease in phylum Firmicutes. Our study provides baseline data of the usefulness of KF in a ketogenic diet. 相似文献
9.
The chromosome 16q22.1‐linked autosomal‐dominant cerebellar ataxia (16q‐ADCA) is a form of spinocerebellar ataxia (SCA) common in Japan. It is clinically characterized by late‐onset purely cerebellar ataxia. The neuropathologic hallmark of 16q‐ADCA is degeneration of Purkinje cells accompanied by an eosinophilic structure which we named “halo‐like amorphous materials”. By immunohistochemistry and electron microscopy, the structure has been so far found to contain two components: the somatic sprouts from the Purkinje cells and presynaptic terminals of unknown origin. As far as we are aware, this peculiar morphological change of Purkinje cells has not been previously described. Further investigations may disclose unique pathological processes in SCA. 相似文献
10.
Terada K Tamiya T Daido S Kambara H Tanaka H Ono Y Matsumoto K Ito S Ouchida M Ohmoto T Shimizu K 《Journal of neuro-oncology》2002,58(2):107-114
We thoroughly examined loss of heterozygosity (LOH) around three candidate tumor suppressor genes on chromosome 10q to determine whether LOH of each tumor suppressor gene is associated with the previously defined clinical prognostic indices. We also examined whether LOH can help predict prognostic variables in astrocytomas.We selected samples from 40 astrocytomas (grades 2–4), performed Ki-67 immunostaining, and counted positive cells. Using DNA from aliquots of tumor blocks and leukocytes, we investigated LOH around the PTEN, NEURL, and DMBT1 genes (10q23.3–26.1) with the silver staining procedure. We then statistically evaluated the relationship among histological features, regional LOH on chromosome 10q, and survival. The mean survival period for patients with LOH around PTEN was 7.2 months after surgery, while that for patients without LOH around PTEN was 21.4 months. Thus, LOH around PTEN was closely associated with a reduced overall survival (p = 0.0020) but LOH at NEURL or DMBT1 was not (p > 0.05).The combined features of an increase in histological grading and Ki-67-positive cells and the presence of LOH around PTEN significantly correlated with poor prognosis. These factors may be useful predictors of survival, and LOH analysis of tumor suppressor genes on chromosome 10q can contribute greatly to the treatment of patients with astrocytoma. 相似文献