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Biomedical subjects

K Hata

Publications and source records attributed to K Hata.

478 records · Page 27Linked to original sources
PubMedDate not supplied

Screening of chemiluminescence constituents of cereals and DPPH radical scavenging activity of gamma-oryzanol.

The chemiluminescence (CL) constituents of cereals were detected by CL using the H(2)O(2)-acetaldehyde system. The cereals tested, such as rice, millet and sorghum, exhibited various levels of CL activity. The gamma-oryzanol fraction was extracted from brown rice and separated into four constituents by HPLC. The four constituents were identified as cycloartenyl ferulate, 24-methylenecycroartanyl ferulate, campesteryl ferulate and beta-sitosteryl ferulate. Free radical scavenging activities with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and CL intensities of four constituents (gamma-oryzanol components) were measured and compared with that of gallic acid, which is a typical free radical scavenger. Four constituents scavenged DPPH radicals and scavenging activities were proportional to CL intensities. Concentrations of four CL constituents required to quench 50% (IC(50)) of the free radicals ranged from 0.9 to 1.1 mmol/L. We demonstrated that measurement of CL intensities was a rapid and convenient method for screening DPPH radical scavenging activities of rice.

Bepridil↗
PubMedDate not supplied

Augmentation of the radiation-induced antiproliferative effect in combined use of a derivative of nitrosourea, ACNU, with recombinant human tumor necrosis factor.

The effect of combined use of a derivative of nitrosourea, ACNU, with recombinant human tumor necrosis factor (rhTNF) on the radiation-induced antiproliferative effect was examined using Meth A tumor cells. The radiation-induced antiproliferative effect was slightly augmented by the simultaneous addition of ACNU at 10 micrograms/ml in 5 Gy and 15 Gy irradiated groups. The antiproliferative effect was augmented in parallel with the radiation dose by the addition of rhTNF. Further augmentation of the proliferation inhibition was observed when both of ACNU (10 micrograms/ml) and 10 U/ml of rhTNF were added in combination with irradiation. Similar augmentation was observed when the target cells were treated with ACNU prior to irradiation and the addition of rhTNF.

Animals↗
PubMedDate not supplied

Perception of dry mouth in a sample of community-dwelling older adults in Japan.

The purpose of this study was to examine the prevalence of perceived dry mouth among a group of independently-living elderly persons in Japan, and to determine its association with general disease, medication, and dental status, as well as its effect on oral function. The study population consisted of participants of the Senior Citizens' College. The subjective sensations of oral dryness on waking and while eating a meal were measured by a questionnaire. The number of usable questionnaires was 1003 or 77.9%. The mean age of the subjects was 66.3 +/- 4.2 years, and 53.0% were male. More than one-third (37.8%) of the subjects reported oral dryness on waking. Only 9.1% of them noticed a subjective feeling of dry mouth during eating. Persons who had at least one of these symptoms made up 41.0%. A multiple stepwise logistic regression analysis indicated the following results: Perception of dry mouth on waking was more frequent among males (p < 0.001), persons who had a low BMI (p < 0.05), and those taking two or more prescribed drugs (p < 0.01). Sensation of dry mouth when eating was more frequent among subjects with a low BMI (p < 0.001) and those who wore a denture in the maxillary arch (p < 0.05). Perception of dry mouth when eating was associated with self-assessed chewing ability (p < 0.01) and dissatisfaction with speaking clearly (p < 0.05), as well as dental status. However, dissatisfaction with tasting a meal had a significant relationship with the reports of mouth dryness on waking (p < 0.01). Our findings suggest that a substantially higher percentage of persons have the perception of dry mouth on waking than when eating, which was associated with medications, being male, and having a low BMI. This perception may influence oral function, especially the reported dissatisfaction with tasting foods.

Aged↗
PubMedDate not supplied

Fundamental frequency as an acoustic cue to accent perception.

It is generally recognized that the most significant cue to accent location is fundamental frequency (F0) in both Japanese and English. Furthermore, it is widely believed that a syllable is perceived as accented if the syllable contains an F0 peak. However, Sugito (1972) found that, in Japanese, if an F0 peak is followed by a steep F0 fall, the syllable preceding the F0 peak may be perceived as accented. In this article we present two experiments which investigate the relationship between F0 peak and F0 fall rate in accent perception for Japanese and English. The first experiment confirms that, for Japanese, both F0 peak location and F0 fall rate affect listeners' judgements of accent location. Specifically, the later the F0 peak occurs in a given syllable, relative to the syllable boundary, the greater the F0 fall rate necessary for listeners to perceive the preceding syllable as accented. The second experiment shows that this phenomenon is not unique to Japanese: Perception of accent location in English is also influenced by both F0 peak location and post-peak F0 fall rate.

Female↗
PubMedDate not supplied

Whole brain irradiation for metastases from lung carcinoma. A clinical investigation.

Sixty-nine consecutive patients with brain metastases from lung carcinoma were randomly allocated to one of two radiation therapy schedules: 30 Gy/10 fractions/2 weeks or 50 Gy/20 fractions/4 weeks. The improvement rate for neurologic function was similar in the two groups. The median survival times for patients receiving the short course and the long course were 4 months and 3 months, respectively. The half-year survival rate was 42 per cent after the short course and 14 per cent after the long course (p less than 0.05). Performance status and lactate dehydrogenase were other factors which significantly influenced the half-year survival rate.

Adenocarcinoma↗
PubMedDate not supplied

Expression of thymidine phosphorylase in human cervical cancer.

OBJECTIVE: Our aim was to evaluate whether the expression of thymidine phosphorylase (TP) by cervical cancer cells is correlated with the density of microvessels within the tumor, histopathologic features, and prognosis. METHODS: Sections of 55 cervical cancers (30 of stage IB, 5 stage IIA, and 20 stage IIB) were analyzed for the cellular expression of TP and the intratumoral density of microvessels by immunohistochemistry using monoclonal antibodies to TP and Factor VIII related antigen, respectively. The main outcome measures were the histopathologic features (histologic type, the maximum longitudinal diameter of the tumor, depth and degree of cervical stromal invasion, lymph-vascular space invasion, parametrial invasion, corpus invasion, vaginal invasion, and pelvic lymph node metastasis), whether or not the tumor cells were TP positive or TP negative, the microvessel count, and disease-free survival. RESULTS: Twenty-nine tumors (52.7%) were classified as TP-positive. The microvessel count (mean +/- SD, 45.6 +/- 12.8) in TP-positive tumors was significantly higher than that (mean +/- SD, 24.3 +/- 9.6) TP-negative tumors (P < 0.0001, Mann-Whitney U test). The disease-free survival of the patients with TP-positive tumors was significantly less than those with TP-negative tumors (P = 0.044, log-rank test). Multivariate analysis revealed that pelvic lymph node metastasis was to be the only independent prognostic factor for disease-free survival (P = 0.041). Moreover, disease-free survival in patients with TP-negative was longer than that in those with TP-positive in pelvic lymph node-negative subgroup, but this did not reach significance (P = 0.247, log-rank test). CONCLUSIONS: Although the expression of TP is not an independent prognostic factor in cervical cancer, it indicates a significantly decreased disease-free survival in patients with TP-positive tumors. These findings provide a potential for new therapeutic intervention mediated by nature that TP inherits in cervical cancer.

Adenocarcinoma↗
PubMedDate not supplied

Vascular endothelial growth factor expression in progression of cervical cancer: correlation with thymidine phosphorylase expression, angiogenesis, tumor cell proliferation, and apoptosis.

BACKGROUND: Vascular endothelial growth factor (VEGF) has been linked not only to angiogenic activity but also to thymidine phosphorylase (TP), rapid tumor growth, and inhibition of apoptotic cell death. Our purpose was to examine how VEGF expression affect these factors in cervical cancer at varying stages of progression. METHODS: VEGF expression, TP expression, the microvessel count (reflected by factor VIII-related antigen), and proliferating cell nuclear antigen (PCNA) were assessed immunohistochemically in 19 specimens of normal cervical epithelium, 35 of carcinoma in situ (CIS), 34 of microinvasive carcinoma (MIC), and 34 of invasive cervical squamous cell carcinoma (SCC). Apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. RESULTS: VEGF expression progressively increased along a continuum from normal epithelium to invasive SCC (P < 0.0001). VEGF expression significantly correlated with TP expression and PCNA index (P < 0.01 and P < 0.0001, respectively). In analyses within histological stages, VEGF expression significantly correlated with the PCNA index in CIS and MIC (P < 0.01 and P < 0.05, respectively), but not in invasive SCC. The PCNA index for combined analysis of VEGF and TP expression was similar to that for VEGF expression alone. VEGF expression tended to correlate with microvessel count, however, the difference was not significant (P = 0.09). No significant correlation was observed between VEGF expression and the apoptotic index. CONCLUSIONS: VEGF expression may stimulate tumor cell proliferation in the early stages of cervical cancer, and may be responsible for cervical tumorigenesis.

Apoptosis↗
PubMedDate not supplied

Expression of thymidine phosphorylase and vascular endothelial growth factor in epithelial ovarian cancer: correlation with angiogenesis and progression of the tumor.

OBJECTIVE: The aim was first, to determine whether the expression of thymidine phosphorylase (TP) and vascular endothelial growth factor (VEGF) by epithelial ovarian cancer cells is correlated with the density of microvessels within the tumor and with ultrasonographic findings (B-mode classification and pulsed Doppler blood flow) and second, to speculate how these two angiogenesis factors participate in the tumorigenesis and tumor progression of epithelial ovarian cancer. METHODS: B-mode ultrasonography and color Doppler imaging and pulsed Doppler spectral analysis were used to scan patients with an overt ovarian mass immediately before laparotomy. Sections of malignant tumors were analyzed for the cellular expression of TP and VEGF and the intratumoral density of microvessels by immunohistochemistry using antibodies to TP, VEGF and Factor VIII related antigen, respectively. The main outcome measures were the histological classification of the tumor, the stage of the disease, whether or not the tumor cells were TP and VEGF positive or negative, the microvessel count and B-mode classification and the peak systolic velocity (PSV). RESULTS: Forty-four epithelial ovarian cancers were studied (6 of low malignant potential, 15 serous cystadenocarcinoma, 9 mucinous cystadenocarcinoma, 8 endometrioid adenocarcinoma, 4 clear cell carcinoma and 2 malignant Brenner tumor); 19 were Stage I, 6 Stage II, 15 Stage III and 4 Stage IV. Fourteen tumors (32%) were classified as TP positive and 21 (48%) as VEGF positive. The proportion of Stage I tumors that were TP positive (16%) was significantly lower (p = 0.022) than the corresponding value for Stages II-IV (44%), but the proportion with VEGF positive, the values for microvessel count and PSV were similar. Microvessel count did not significantly related to TP nor VEGF expression. The PSV was significantly higher in TP-positive tumors (p = 0.02) and VEGF-positive tumors (p = 0.006), respectively. There was a significant correlation between the microvessel count and the PSV (r = 0.34, p = 0.024). Moreover, specific B-mode classification significantly associated with disease stage and with TP expression, but not with VEGF expression. CONCLUSIONS: Angiogenesis is an early, critical step in the tumorigenesis of epithelial ovarian cancer, however, it does not provide significant information about tumor aggressiveness. When TP expression is superimposed upon the VEGF expression, the tumor might acquire the aggressive tumor phenotype.

Adenocarcinoma, Clear Cell↗
PubMedDate not supplied

Evaluation of intraoperative radiotherapy for carcinoma of the pancreas: prognostic factors and survival analyses.

Among 145 patients with carcinoma of the pancreas who had been admitted to three institutions between 1976 and 1985, 117 were entered into a prognostic factor analysis system according to Cox's proportional hazards model. The treatment was classified into four modalities: bypass surgery, single-dose intraoperative radiotherapy (IOR), IOR combined with external irradiation, and resection with or without various radiations. The most important prognostic factors for treatment were identified as location of tumor, TNM stage, and relief of back pain. Adjusting the imbalances among the treatment groups using Cox's model, the superiority of IOR with external irradiation was confirmed for both bypass and single-dose IOR. With this adjustment, the survival rates proved to be more meaningful than the simple Kaplan-Meier estimates.

Adenocarcinoma↗