Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 298
Filter
1.
Rev Sci Instrum ; 95(7)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-39016700

ABSTRACT

A real-time processing system for the two-color CO2 laser interferometer on the JT-60SA has been developed for density feedback control. The system has a novel feature that can detect fringe jumps due to off-normal events, such as loss detection due to displacement of the beam axis and changes in the laser wavelengths. Because a phase change due to the JT-60SA plasma is smaller than π/2, corresponding to the line-integral electron density NL of ∼6×1019 m-2 in a short interval of 500 ns, the threshold of the fringe jump detection is decided to be π/2. Hence, off-normal events can be detected from a fringe jump, leading to the abort of the real-time feedback control. In the density feedback control of the JT-60SA plasma, the system is employed as a density monitor, with NL being successfully controlled at 16.8% ± 6.6% lower than the reference.

2.
Rev Sci Instrum ; 87(11): 11D424, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27910550

ABSTRACT

In the divertor simulation experiments in the GAMMA 10/PDX tandem mirror, pressure of the neutral gas was investigated by using a fast ionization gauge. The gauge was absolutely calibrated for hydrogen gas by using a capacitance manometer. Change of the gauge sensitivity due to the magnetic field of GAMMA 10/PDX was also evaluated. The typical gas pressure measured in detached plasma experiments was 0.1-10 Pa. The degree of plasma detachment determined from the reduction of heat flux was enhanced as the gas pressure increases. Rapid increase of the gas pressure under the plasma flow was also observed.

3.
J Biol Regul Homeost Agents ; 29(3): 589-600, 2015.
Article in English | MEDLINE | ID: mdl-26403397

ABSTRACT

This study aimed to determine the seasonality of reproduction throughout the year in Japanese wood mice (Apodemus speciosus). The effect of seasonal changes on testicular morphology and the periodic expression of circadian clock genes in the hypothalamus and testes of male individuals was evaluated. We also examined the morphology of the testes and caudae epididymides of male mice. In addition, RT-PCR analysis was carried out with mRNA extracted from the hypothalamus and testes to evaluate the expression of the circadian clock genes Clock, Bmal1, Per1, and Cry1. The complete induction of testicular activity was detected from February to April and from August to October, with testes weight increasing with the completion of spermatogenesis (reproductive season). From May to early June and from November to early January, testicular weight declined, the seminiferous tubules reduced in size, spermatogenesis was arrested, and sperm were not produced (non-reproductive season). From mid- June to July and mid-January, the re-induction of testicular activity for spermatogenesis was observed in the seminiferous tubules (transitional season). Out of the four examined genes, Cry1 had the highest expression level in both the hypothalamus and testes throughout the year, followed by Bmal1, Per1, and Clock. The expression of Bmal1 was significantly lower in the hypothalamus and testes during the transitional season compared to the reproductive and non-reproductive seasons. Cry1 transcript levels were also significantly lower in the hypothalamus and testes during the transitional season compared to the reproductive season. In conclusion, the results indicating changes in testicular morphology revealed annual reproductive, non-reproductive, and transmission periods in Japanese wood mice. When an increase in testicular activity was observed indicating the onset of the reproductive season, the mean day length was approximately 11–13 h. The expression of the circadian clock genes Bmal1 and Cry1 in the hypothalamus and testes during the reproductive season was significantly higher than that of the same genes during the transitional season. Consequently, completion of spermatogenesis occurred in the seminiferous tubules of Japanese wood mice testes during the reproductive period.


Subject(s)
Circadian Rhythm/physiology , Gene Expression Regulation/physiology , Seasons , Testis/metabolism , Animals , Hypothalamus/metabolism , Male , Mice
4.
J Dent Res ; 94(3 Suppl): 28S-36S, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25294364

ABSTRACT

Poor oral health and hygiene are increasingly recognized as major risk factors for pneumonia among the elderly. To identify modifiable oral health-related risk factors, we prospectively investigated associations between a constellation of oral health behaviors and incident pneumonia in the community-living very elderly (i.e., 85 years of age or older). At baseline, 524 randomly selected seniors (228 men and 296 women; mean age, 87.8 years) were examined for oral health status and oral hygiene behaviors as well as medical assessment, including blood chemistry analysis, and followed up annually until first hospitalization for or death from pneumonia. During a 3-year follow-up period, 48 events associated with pneumonia (20 deaths and 28 acute hospitalizations) were identified. Among 453 denture wearers, 186 (40.8%) who wore their dentures during sleep were at higher risk for pneumonia than those who removed their dentures at night (log rank P = 0.021). In a multivariate Cox model, both perceived swallowing difficulties and overnight denture wearing were independently associated with an approximately 2.3-fold higher risk of the incidence of pneumonia (for perceived swallowing difficulties, hazard ratio [HR], 2.31; and 95% confidence interval [CI], 1.11-4.82; and for denture wearing during sleep, HR, 2.38; and 95% CI, 1.25-4.56), which was comparable with the HR attributable to cognitive impairment (HR, 2.15; 95% CI, 1.06-4.34), history of stroke (HR, 2.46; 95% CI, 1.13-5.35), and respiratory disease (HR, 2.25; 95% CI, 1.20-4.23). In addition, those who wore dentures during sleep were more likely to have tongue and denture plaque, gum inflammation, positive culture for Candida albicans, and higher levels of circulating interleukin-6 as compared with their counterparts. This study provided empirical evidence that denture wearing during sleep is associated not only with oral inflammatory and microbial burden but also with incident pneumonia, suggesting potential implications of oral hygiene programs for pneumonia prevention in the community.


Subject(s)
Dentures , Health Behavior , Pneumonia/etiology , Sleep , Aged, 80 and over , Candida albicans/isolation & purification , Cause of Death , Cognition Disorders/complications , Cohort Studies , Deglutition Disorders/complications , Dental Plaque/etiology , Dentures/adverse effects , Dentures/microbiology , Female , Follow-Up Studies , Gingivitis/etiology , Health Status , Hospitalization , Humans , Independent Living , Interleukin-6/blood , Male , Oral Health , Oral Hygiene , Prospective Studies , Respiratory Tract Diseases/complications , Risk Factors , Stroke/complications , Tongue/pathology
5.
Methods Inf Med ; 51(5): 383-94, 2012.
Article in English | MEDLINE | ID: mdl-22614791

ABSTRACT

BACKGROUND: Over 100 limited sampling strategies (LSSs) have been proposed to reduce the number of blood samples necessary to estimate the area under the concentration-time curve (AUC). The conditions under which these strategies succeed or fail remain to be clarified. OBJECTIVES: We investigated the accuracy of existing LSSs both theoretically and numerically by Monte Carlo simulation. We also proposed two new methods for more accurate AUC estimations. METHODS: We evaluated the following existing methods theoretically: i) nonlinear curve fitting algorithm (NLF), ii) the trapezium rule with exponential curve approximation (TZE), and iii) multiple linear regression (MLR). Taking busulfan (BU) as a test drug, we generated a set of theoretical concentration-time curves based on the identified distribution of pharmacokinetic parameters of BU and re-evaluated the existing LSSs using these virtual validation profiles. Based on the evaluation results, we improved the TZE so that unrealistic parameter values were not used. We also proposed a new estimation method in which the most likely curve was selected from a set of pre-generated theoretical concentration-time curves. RESULTS: Our evaluation, based on clinical profiles and a virtual validation set, revealed: i) NLF sometimes overestimated the absorption rate constant Ka, ii) TZE overestimated AUC over 280% when Ka is small, and iii) MLR underestimated AUC over 30% when the elimination rate constant Ke is small. These results were consistent with our mathematical evaluations for these methods. In contrast, our two new methods had little bias and good precision. CONCLUSIONS: Our investigation revealed that existing LSSs induce different but specific biases in the estimation of AUC. Our two new LSSs, a modified TZE and one using model concentration-time curves, provided accurate and precise estimations of AUC.


Subject(s)
Area Under Curve , Models, Statistical , Selection Bias , Antineoplastic Agents, Alkylating/pharmacokinetics , Busulfan/pharmacokinetics , Monte Carlo Method
6.
Oncogenesis ; 1: e12, 2012 Jun 04.
Article in English | MEDLINE | ID: mdl-23552696

ABSTRACT

Radioresistance, which is a major cause of failure of radiotherapy (RT), is proposed as one of the intrinsic characteristics of cancer stem cells (CSCs) whose unique DNA damage response (DDR), efficient DNA repair and resistance to apoptosis are thought to confer the phenotype. We have isolated surviving CSCs by exposure to long-term fractionated radiation for 82 days from HepG2 and A172 cells (82FR-31NR cells). 82FR-31NR cells exhibited CSC properties, such as high expression of CSC marker CD133 and the ABC transporters (MDR1 and BCRP1), and high tumorigenic potential after transplantation into nude mice. The advantage of our isolated CSCs is that they can proliferate in as the same growth medium as that of parental cells without loss of CSC properties. Therefore, we can analyze DDR of non-stem cells and CSCs without any influences caused by different culture conditions. 82FR-31NR cells showed efficient DNA repair of radiation-induced DNA damage and radioresistance with activation of the AKT/cyclin D1 survival signaling pathway. In contrast, DNA damage persisted for a long time after irradiation in parental cells compared with isolated CSCs. Persisted DNA damage induced apoptosis in parental cells without activation of the AKT/cyclin D1 pathway. Therefore, inhibition of the AKT/cyclin D1 pathway by an AKT inhibitor, API-2, or cyclin D1 siRNA resulted in a loss of efficient DNA repair and radiosensitization of 82FR-31NR cells. Furthermore, knockdown of Cdk4 by its siRNA or a Cdk4 inhibitor was sufficient to suppress radioresistance of CSCs. In this study, we present a newly discovered DDR regarding the AKT/cyclin D1/Cdk4 pathway in response to radiation in CSCs. Combination of fractionated RT and reagents targeting the AKT/cyclin D1/Cdk4 pathway to eradicate CSCs would be effective therapeutic modality.

7.
Cell Death Dis ; 2: e177, 2011 Jun 30.
Article in English | MEDLINE | ID: mdl-21716292

ABSTRACT

Radiotherapy is a well-established treatment for cancer. However, the existence of radioresistant cells is one of the major obstacles in radiotherapy. In order to understand the mechanism of cellular radioresistance and develop more effective radiotherapy, we have established clinically relevant radioresistant (CRR) cell lines, which continue to proliferate under daily exposure to 2 Gray (Gy) of X-rays for >30 days. X-ray irradiation significantly induced autophagic cells in parental cells, which was exiguous in CRR cells, suggesting that autophagic cell death is involved in cellular radiosensitivity. An autophagy inducer, rapamycin sensitized CRR cells to the level of parental cells and suppressed cell growth. An autophagy inhibitor, 3-methyladenine induced radioresistance of parental cells. Furthermore, inhibition of autophagy by knockdown of Beclin-1 made parental cells radioresistant to acute radiation. These suggest that the suppression of autophagic cell death but not apoptosis is mainly involved in cellular radioresistance. Therefore, the enhancement of autophagy may have a considerable impact on the treatment of radioresistant tumor.


Subject(s)
Autophagy/drug effects , Neoplasms/drug therapy , Neoplasms/radiotherapy , Radiation Tolerance/drug effects , Adenine/analogs & derivatives , Adenine/pharmacology , Adenine/therapeutic use , Cell Death/drug effects , Cell Survival/drug effects , Humans , Neoplasms/pathology , Tumor Cells, Cultured , X-Rays
9.
Oncogene ; 29(34): 4826-37, 2010 Aug 26.
Article in English | MEDLINE | ID: mdl-20562919

ABSTRACT

Recurrence is frequently associated with the acquisition of radioresistance by tumors and resulting failures in radiotherapy. We report, in this study, that long-term fractionated radiation (FR) exposures conferred radioresistance to the human tumor cells, HepG2 and HeLa with cyclin D1 overexpression. A positive feedback loop was responsible for the cyclin D1 overexpression in which constitutively active AKT was involved. AKT is known to inactivate glycogen synthase kinase-3beta (GSK3beta), which is essential for the proteasomal degradation of cyclin D1. The resulting cyclin D1 overexpression led to the forced progression of S-phase with the induction of DNA double strand breaks. Cyclin D1-dependent DNA damage activated DNA-dependent protein kinase (DNA-PK), which in turn activated AKT and inactivated GSK3beta, thus completing a positive feedback loop of cyclin D1 overproduction. Cyclin D1 overexpression led to the activation of DNA damage response (DDR) consisted of ataxia telangiectasia mutated (ATM)- and Chk1-dependent DNA damage checkpoint and homologous recombination repair (HRR). Long-term FR cells repaired radiation-induced DNA damage faster than non-FR cells. Thus, acquired radioresistance of long-term FR cells was the result of alterations in DDR mediated by cyclin D1 overexpression. Inhibition of the AKT/GSK3beta/cyclin D1/Cdk4 pathway by the AKT inhibitor, Cdk4 inhibitor or cyclin D1 targeting small interfering RNA (siRNA) suppressed the radioresistance. Present observations give a mechanistic insight for acquired radioresistance of tumor cells by cyclin D1 overexpression, and provide novel therapeutic targets for recurrent radioresistant tumors.


Subject(s)
Cyclin D1/biosynthesis , DNA-Activated Protein Kinase/metabolism , Glycogen Synthase Kinase 3/metabolism , Neoplasms/radiotherapy , Oncogene Protein v-akt/metabolism , Cyclin D1/genetics , Cyclin D1/metabolism , Cyclin-Dependent Kinase 4/metabolism , DNA Damage , DNA Repair , Down-Regulation , G1 Phase/physiology , Glycogen Synthase Kinase 3 beta , HeLa Cells , Hep G2 Cells , Humans , Neoplasms/genetics , Neoplasms/metabolism , Neoplasms/pathology , Radiation Tolerance , S Phase/physiology , Signal Transduction
10.
J Dent Res ; 88(11): 1008-13, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19828888

ABSTRACT

A non-viral gene delivery approach with nano/microbubbles and ultrasound offers opportunities for targeting soft tissues for gene therapy. The periodontium is a complex structure comprised of hard (cementum, alveolar bone) and soft tissues (periodontal ligament, gingivae). We hypothesized that our established gene delivery method would allow the periodontal tissue to be targeted for transfection for gene therapy. Expression kinetics and sites of transfection sites with this approach were investigated in rat periodontal tissue. Bioluminescence imaging revealed that transient gene expression was induced at day 1 posttransfection, while confocal microscopy showed that gene expression was localized in the muscle cells of gingival tissues. These findings indicate that regular transfection with this approach results in high gene expression, facilitating gene therapy for periodontal disease involving alveolar bone resorption.


Subject(s)
Gene Transfer Techniques , Microbubbles , Nanostructures , Periodontium/metabolism , Ultrasonics , Animals , Fluorescent Dyes , Gene Expression Regulation , Gene Transfer Techniques/instrumentation , Genes, Reporter , Genetic Therapy , Genetic Vectors , Gingiva/metabolism , Green Fluorescent Proteins , Luciferases, Firefly , Luminescence , Luminescent Agents , Male , Microscopy, Confocal , Muscle Cells/metabolism , Periodontal Diseases/therapy , Rats , Rats, Wistar , Simian virus 40/genetics , Time Factors , Transfection
11.
Eur J Gynaecol Oncol ; 30(1): 16-9, 2009.
Article in English | MEDLINE | ID: mdl-19317250

ABSTRACT

Ovarian tumors of low malignant potential (LMP) appear to be intermediate between adenomas and ovarian carcinomas. Such tumors are often associated with a significantly better prognosis than for ovarian carcinomas. However, a subset of LMPs can progress and become lethal even in patients with early-stage disease. In order to seek sensitive diagnostic tools to monitor patients after surgical therapy, we performed a genome-wide scan for LOH in 37 early-stage mucinous LMPs using 91 polymorphic microsatellite markers at an average interval of 50 cM across all of the human chromosomes and 25 LOH markers reported to be associated with ovarian carcinoma. Fractional allelic loss (FAL) values were calculated as (loci scored with LOH)/(total informative loci) for each sample. With respect to tumor recurrence, high FAL values were more frequent in recurrent tumors than in non-recurrent tumors. Using the screening markers, FAL values for recurrent tumors were significantly higher than for non-recurrent tumors (19.8% vs 6.3%, respectively, p < 0.0001). Similar results were obtained using the hotspot markers (22.2% vs 7.1%, respectively, p < 0.0001). A significant correlation between FAL values obtained using screening markers and those based on hotspot markers was observed (R = 0.460, p = 0.003). Our findings suggest that a specific type of genetic instability (i.e., chromosomal instability, CIN) may exist in mucinous LMPs, and that this instability may indicate tumors with an aggressive biological nature. Therefore, FAL values may represent a new biomarker for risk prediction in early-stage mucinous LMP tumors.


Subject(s)
Adenocarcinoma, Mucinous/genetics , Loss of Heterozygosity , Microsatellite Repeats , Neoplasm Recurrence, Local/genetics , Ovarian Neoplasms/genetics , Adenocarcinoma, Mucinous/pathology , Cohort Studies , Disease Progression , Female , Humans , Ovarian Neoplasms/pathology , Survival Analysis
12.
Br J Cancer ; 99(12): 2020-8, 2008 Dec 16.
Article in English | MEDLINE | ID: mdl-19018267

ABSTRACT

This study examined the status of KRAS and BRAF mutations, in relation to extracellular signal-regulated protein kinase (ERK) activation in 58 ovarian carcinomas to clarify the clinicopathological and prognostic significance of KRAS/BRAF mutations. Somatic mutations of either KRAS or BRAF were identified in 12 (20.6%) out of 58 ovarian carcinomas. The frequency of KRAS/BRAF mutations in conventional serous high-grade carcinomas (4.0% : 1/25) was significantly lower than that in the other histological type (32.3% : 10/31). Phosphorylated ERK1/2 (p-ERK1/2) expression was identified in 18 (38.2%) out of 45 ovarian carcinomas. KRAS/BRAF mutation was significantly correlated with International Federation of Gynecology and Obstetrics (FIGO) stage I, II (P<0.001), and p-ERK1/2 (P<0.001). No significant correlations between KRAS/BRAF mutations or p-ERK1/2 expression and overall survival were found in patients with ovarian carcinoma treated with platinum and taxane chemotherapy (P=0.2460, P=0.9339, respectively). Next, to clarify the roles of ERK1/2 activation in ovarian cancers harbouring KRAS or BRAF mutations, we inactivated ERK1/2 in ovarian cancer cells using CI-1040. Cl-1040 is a compound that selectively inhibits MAP kinase kinase (MEK), an upstream regulator of ERK1/2, and thus prevents ERK1/2 activation. Profound growth inhibition and apoptosis were observed in CI-1040-treated cancer cells with mutations in either KRAS or BRAF in comparison with the ovarian cancer cells containing wild-type sequences. This was evident in both in vitro and in vivo studies. The findings in this study indicate that an activated ERK1/2 pathway is critical to tumour growth and survival of ovarian cancers with KRAS or BRAF mutations. Furthermore, they suggest that the CI-1040-induced phenotypes depend on the mutational status of KRAS and BRAF in ovarian cancers. Therefore, ovarian cancer patients with KRAS or BRAF mutations may benefit from CI-1040 treatment.


Subject(s)
Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors , Ovarian Neoplasms/enzymology , Ovarian Neoplasms/genetics , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins/genetics , ras Proteins/genetics , Animals , Base Sequence , Cell Line, Tumor , Cell Proliferation , Enzyme Activation , Female , Humans , Mice , Mice, Nude , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3/metabolism , Mitogen-Activated Protein Kinase Kinases/metabolism , Mutation/genetics , Ovarian Neoplasms/pathology , Phosphorylation , Prognosis , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins p21(ras) , Substrate Specificity , Survival Rate , Xenograft Model Antitumor Assays , ras Proteins/metabolism
13.
Oncogene ; 26(26): 3835-45, 2007 May 31.
Article in English | MEDLINE | ID: mdl-17160015

ABSTRACT

Tumor suppressor p53 is essential for checkpoint control in response to a variety of genotoxic stresses. DNA damage leads to phosphorylation on the Ser/Thr-Pro motifs of p53, which facilitates interaction with Pin1, a pSer/pThr-Pro-specific peptidyl prolyl isomerase. Pin1 is required for the timely activation of p53, resulting in apoptosis or cell cycle arrest. To investigate the physiological relationship between Pin1 and p53, we created Pin1-/-p53-/- mice. These p53-deficient mice spontaneously developed lymphomas, mainly of thymic origin, as well as generalized lymphoma infiltration into other organs, including the liver, kidneys and lungs. Ablation of Pin1, in addition to p53, accelerated the thymic hyperplasia, but the thymocytes in these Pin1-/-p53-/- mice did not infiltrate other organs. The thymocytes in 12-week-old Pin1-/-p53-/- mice were CD4(-)CD8(-) (double negative) and had significantly higher levels of the intracellular form of Notch1 (NIC) than the thymocytes of p53-/- or wild-type mice. Presenilin-1, a cleavage enzyme for NIC generation from full-length Notch1 was increased in the thymocytes of Pin1-/-p53-/- mice. Pin1 depletion also inhibited the degradation of NIC by proteasomes. These results suggest that both Pin1 and p53 control the normal proliferation and differentiation of thymocytes by regulating the NIC level.


Subject(s)
Peptidylprolyl Isomerase/deficiency , Receptor, Notch1/metabolism , T-Lymphocytes/metabolism , Thymus Hyperplasia/metabolism , Tumor Suppressor Protein p53/deficiency , Animals , Blotting, Western , Female , Flow Cytometry , Intracellular Fluid/chemistry , Male , Mice , Mice, Knockout , NIMA-Interacting Peptidylprolyl Isomerase , Presenilin-1/metabolism , T-Lymphocytes/immunology , Thymus Hyperplasia/genetics , Thymus Hyperplasia/pathology , Tumor Suppressor Protein p53/genetics
14.
Diabetes Obes Metab ; 7(4): 390-6, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15955125

ABSTRACT

AIM: Although microalbuminuria has been suggested as an independent risk factor for ischemic heart disease, the relationship between diabetic nephropathy and macroangiopathy remains unclear. Previously, we reported that coronary artery calcification detected by electron beam computed tomography (EBCT) could indicate the degree of coronary atherosclerosis in type 2 diabetic patients. In this study, we examine the association between coronary arterial calcification and microalbuminuria and aortic calcification and microalbuminuria. METHODS: Two hundred and fifty-six patients, including 177 type 2 diabetic patients (106 patients with normoalbuminuria, 71 with microalbuminuria) and 79 non-diabetic patients were evaluated by assessing the urinary albumin excretion rate and using EBCT to determine a coronary calcification score (CCS) and an aortic calcification score (ACS). RESULTS: No differences were observed regarding age, smoking index or BMI. Diabetic patients exhibited a greater CCS than non-diabetic subjects (non-diabetes 33 +/- 75 vs. diabetes 203 +/- 467, p < 0.05). Diabetic patients with microalbuminuria exhibited the most advanced CCS (253 +/- 491, p < 0.05). In contrast, no difference was observed in ACS among three groups. Multiple regression analysis showed that CCS is significantly associated with urinary albumin excretion rate as well as age, duration of diabetes and serum creatinine (R(2) = 0.31), while ACS is strongly associated with age, smoking, serum creatinine, systolic blood pressure and low-density lipoprotein cholesterol level (R(2) = 0.29). CONCLUSION: Increased urinary albumin excretion is associated with coronary arterial calcification in diabetic patients.


Subject(s)
Albuminuria/complications , Calcinosis/complications , Coronary Artery Disease/complications , Diabetes Mellitus, Type 2/complications , Age Factors , Aortic Diseases/complications , Blood Pressure/physiology , Body Mass Index , Cholesterol, LDL/blood , Creatinine/blood , Diabetic Nephropathies/complications , Female , Humans , Male , Middle Aged , Risk Factors , Smoking , Time Factors , Tomography, X-Ray Computed/methods
15.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 5812-5, 2005.
Article in English | MEDLINE | ID: mdl-17281580

ABSTRACT

EMG-based VAD is proposed. It is generally known that EMG signals are not affected by acoustic noise and preceding voice. Robust but preceding detection of speech can be expected by using these features. The proposed method extracts one VAD parameter to judge speech or silence from among n EMG signal channels. Experiments are performed to confirm the effectiveness of the proposed method. The results show that some EMG signals reliably precede voice by 30ms or more. Compared with conventional audio VAD, the proposed method seldom drops the speech head and the method's performance is relatively insensitive to background noise.

16.
Appl Radiat Isot ; 62(2): 231-6, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15607454

ABSTRACT

Microcline feldspar crystal has been analyzed in order to determine the centers suitable for use in ESR and luminescence dating. ESR measurements at RT showed the Fe3+ line, and at 77K the Si-O(-) ..X signal with g=2.0052, 2.0098 and 2.0128. TL glow peak at 157 and 300 degrees C in UV interval were observed and in the VIS range we noted peaks at 150, 280 and 340 degrees C. TL growth curve of the 340 degrees C peak could be fitted by a saturating exponential equation and can be used in TL dating. Emission curves showed band widths 1.95+/-0.09, 2.73+/-0.08 and 4.94+/-0.50 eV. Transitions from 4T1-->6A1)of Fe3+ can be associated with the 1.95 eV band and the transition from 4A1 4E(G)-->6A1(S) with 2.73 eV band.

17.
Br J Cancer ; 90(6): 1204-10, 2004 Mar 22.
Article in English | MEDLINE | ID: mdl-15026802

ABSTRACT

Ovarian tumours of low malignant potential (LMP) are intermediate between adenomas and ovarian carcinomas. These tumours are often associated with a significantly better prognosis than ovarian carcinomas. However, a subset of these tumours can progress and become lethal. In order to seek sensitive diagnostic tools for monitoring patients after surgical operation, we performed a genome-wide scan for loss of heterozygosity (LOH) in 41 mucinous LMPs using 91 polymorphic microsatellite markers at an average interval of 50 cM across all of the human chromosomes and 25 LOH markers reportedly associated with ovarian carcinoma. In addition, we assessed whether clinicopathological parameters, microvessel density, Ki-67 labeling index, apoptotic index or p53 overexpression would be useful for predicting the postoperative outcome of LMP patients. Of the 116 markers examined, 19q12 and Xq11-12 showed significant correlation between postoperative progression-free survival time and LOH status (P<0.05). Patients with a high Ki-67 labeling index had a significantly poorer progression-free survival time than those with lower levels (P=0.042). Other clinicopathological factors and immunohistochemical analysis had no correlation with progression-free survival time in this series of patients. When the combination of LOH at 19q12 and/or Xq11-12 was assessed using Cox's regression analysis, patients with tumours that showed LOH at these positions were at greatest risk of progression (P=0.0073). These findings suggest that the identification of LOH at 19q12 and/or Xq11-12 in former mucinous LMP sites should alert the clinician to the presence of a potentially aggressive lesion in the coelomic epithelium, even if a distinction between second primary tumours or recurrence could not be determined.


Subject(s)
Adenocarcinoma, Mucinous/genetics , Adenocarcinoma, Mucinous/pathology , Chromosomes, Human, Pair 19 , Chromosomes, Human, X , Genetic Markers , Loss of Heterozygosity , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Adult , Disease-Free Survival , Female , Humans , Microsatellite Repeats , Middle Aged , Prognosis , Regression Analysis , Retrospective Studies , Risk Factors
18.
Int J Oral Maxillofac Surg ; 31(4): 451-4, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12361085

ABSTRACT

Nerve sheath myxoma (NSM) is a benign peripheral nervous system tumour that rarely occurs in the oral cavity. Among 17 cases of oral NSM described in the literature (average patient age 33 years), only two, including the present case, have been reported in children. The present case occurring in an 8-year-old boy was therefore extremely rare. Histopathologically, the tumour was found as multinodules under the mucosal epithelium, and was composed of spindle- or stellate-shaped cells with a myxoid background that stained with alcian blue and toluidine blue. Immunohistochemically, the tumour cells were strongly positive for S-100 beta protein and neuron-specific enolase. These results suggested that the tumour originated from Schwann cells.


Subject(s)
Neurothekeoma/pathology , Tongue Neoplasms/pathology , Child , Humans , Male
19.
Neuroradiology ; 44(4): 286-93, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11914802

ABSTRACT

We investigated whether dynamic computed tomography (CT) in patients with acute cerebral infarction could identify patients likely to respond to anti-platelet therapy. Seventy patients underwent semiquantitative dynamic CT within 6 h as well as cerebral angiography. All then received anti-platelet therapy with a thromboxane A2 synthetase inhibitor. Peak value (pv) and time-to-peak (tp) (time-density curves) for the Sylvian fissure were extracted from dynamic CT data and standardizing interpatient data, two indices, PV/TP index and TP index, were prepared following a standard semiquantitative manner. Both PV/TP index and TP index were effective in discriminating between 48 responders (modified Rankin scale (mRS): 0 to 2) and 22 non-responders (mRS: 3 to 5, or death: 6; both P<0.0001). High PV/TP index (>or=0.8) was a strong indicator of favorable response. Most of these patients maintained regional cerebral blood flow (rCBF) via anterograde flow or collaterals, with a TP index 1.1) and non-compensated rCBF. Intermediate PV/TP values could not predict outcome. Dynamic CT prior to therapy can identify patients with acute cerebral infarction who are treatable with anti-platelet therapy alone.


Subject(s)
Enzyme Inhibitors/therapeutic use , Infarction, Middle Cerebral Artery/diagnostic imaging , Methacrylates/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Thromboxane-A Synthase/antagonists & inhibitors , Tomography, X-Ray Computed , Acute Disease , Aged , Brain/diagnostic imaging , Cerebral Angiography , Female , Humans , Infarction, Middle Cerebral Artery/drug therapy , Male , Predictive Value of Tests , Prognosis , Treatment Outcome
20.
Int J Cancer ; 94(4): 605-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11745452

ABSTRACT

Ovarian tumors of low malignant potential (LMP) are intermediate between adenomas and ovarian carcinomas (OC); however, the relevance of LMP to ovarian carcinogenesis is not clear. We performed a comparative analysis of allelotypes in 50 cases of LMP (42 mucinous and 8 serous) and 23 cases of OC (15 mucinous and 8 serous) to investigate any differences in genetic changes. Analysis of loss of heterozygosity (LOH) using 25 microsatellite markers reportedly associated with OC revealed that the total LOH frequency at each marker was significantly lower in LMP than in OC (p < 0.01). However, 9 (36%) loci showed higher LOH frequency in mucinous LMP than in mucinous OC. A genome-wide scan for LOH using 91 microsatellite markers and fine mapping revealed that LOH at D7S1805 (7q35) is characteristic of mucinous LMP (19.4% in mucinous LMP, 8.3% in mucinous OC). We further studied LOH in 3 cases of mucinous OC that were accompanied by mucinous LMP lesions. In 2 cases, LOH frequency was higher in the carcinoma portion than in the morphologically LMP portion. The other case showed microsatellite instability in the morphologically LMP portion and LOH in the carcinoma portion. Our results suggest the presence of an LMP-to-OC developmental sequence and the existence of a subset of LMP that does not develop into OC in the mucinous subtype of ovarian tumors.


Subject(s)
Genetic Predisposition to Disease , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Adenoma/pathology , Alleles , Carcinoma/pathology , Chromosome Mapping , Female , Gene Deletion , Genome , Humans , Loss of Heterozygosity , Microsatellite Repeats , Neoplasm Metastasis , Ovarian Neoplasms/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...