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Biomedical subjects

K Hata

Publications and source records attributed to K Hata.

At least 91 records · Page 5Linked to original sources
PubMed1999

Thymidine phosphorylase expression in progression of cervical cancer: correlation with microvessel count, proliferating cell nuclear antigen, and apoptosis.

AIMS: To determine how epithelial and stromal thymidine phosphorylase expression affects angiogenesis, rapid tumour growth, and decreased apoptotic activity in cervical cancer at varying stages of progression. METHODS: Epithelial and stromal thymidine phosphorylase expression, the microvessel count (reflected by factor VIII related antigen), and proliferating cell nuclear antigen (PCNA) were assessed immunohistochemically in 25 specimens of normal cervical epithelium, 35 of carcinoma in situ (CIS), 34 of microinvasive carcinoma, and 34 of invasive cervical squamous cell carcinoma. Apoptosis was evaluated by the terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labelling (TUNEL) method. The relation of epithelial and stromal thymidine phosphorylase expression to microvessel count, PCNA index, and apoptotic index was examined. RESULTS: Epithelial and stromal thymidine phosphorylase expression progressively increased along a continuum from normal epithelium to invasive squamous cell carcinoma. Epithelial and stromal thymidine phosphorylase expression showed a significant positive correlation with microvessel counts. Within each histological stage, CIS cases with high stromal thymidine phosphorylase expression, invasive squamous cell carcinoma cases with high epithelial thymidine phosphorylase expression, and microinvasive carcinoma cases with high thymidine phosphorylase expression in both epithelium and stroma had a significantly higher microvessel count. High epithelial thymidine phosphorylase expression was associated with a significantly higher PCNA index in CIS and microinvasive carcinoma, but not in invasive squamous cell carcinoma. No significant correlation was seen between apoptotic index and either epithelial or stromal thymidine phosphorylase expression or microvessel count. CONCLUSIONS: Epithelial and stromal thymidine phosphorylase expression may combine to promote angiogenesis during progression of cervical cancer, and epithelial thymidine phosphorylase expression may stimulate tumour cell proliferation in the early stages.

Apoptosis↗
PubMed1999

Prognosis of patients with stage IIIb-IVa squamous cell carcinoma of the cervix following intra-arterial neoadjuvant chemotherapy.

Our purpose was to determine the long-term prognosis in patients with stage IIIb-IVa squamous cell carcinoma of the cervix who were treated with intra-arterial neoadjuvant chemotherapy (NAC), and to analyze factors related to prognostic value. We assessed the disease-free survival of 21 patients with FIGO stage IIIb-IVa squamous cell carcinoma of the cervix treated with intra-arterial NAC (cisplatin 70 mg/m2 and peplomycin sulfate 30 mg/m2) followed by irradiation therapy. Before chemotherapy, five factors (age, clinical stage, histologic type, parametrial involvement and serum level of SCC) were evaluated for their correlation with disease-free survival. The absolute 5-year disease-free survival rate for the entire group was 52%, with a median follow-up time in disease-free survivors of 87 months. Among the prognostic factors, age was the only one to be significantly correlated with disease-free survival; older (> 60 years) patients showed a significantly better disease-free survival rate than did younger (< 60 years) patients (p < 0.05, log-rank test). The absolute 5-year disease-free survival rate was 69% for older patients and 25% for younger patients. Univariate Cox's proportional hazard model also demonstrated that age was a significant prognostic factor as a continuous variable (p < 0.01). Intra-arterial NAC thus appeared to be effective in treating older patients with stage IIIb-IVa squamous cell carcinoma of the cervix.

Adult↗
PubMed1999

Co-expression of vascular endothelial growth factor and thymidine phosphorylase in endometrial cancer.

OBJECTIVE: To examine expression of vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP) together with microvessel count in endometrial cancer, and to investigate the relationship with clinicopathological and biological factors. METHODS: VEGF expression, TP expression, the microvessel count (factor VIII-related antigen positive cells), bcl-2 expression, proliferating cell nuclear antigen (PCNA) index, and p53 expression were determined in 50 resected endometrial cancer specimens, using immunohistochemistry. The relationship between VEGF and TP expression and correlation between expression and microvessel count were also given attention. These 3 factors were analyzed with regard to clinicopathological factors, bcl-2 expression, PCNA index, and p53 expression. RESULTS: Staining status of VEGF and TP was identical in 37 (74%) of 50 tumors, the correlation being statistically significant (p < 0.01). Combined analysis of VEGF and TP status showed that tumors which were VEGF-positive and/or TP-positive had a significantly higher microvessel count than did tumors which were both VEGF-negative and TP-negative (p < 0.001 and p < 0.05, respectively). TP expression correlated with bcl-2 expression, and VEGF expression inversely correlated with the PCNA index. Although clinical stage (p < 0.01), PCNA index (p < 0.01), and p53 expression (p < 0.01) significantly correlated with disease-free survival, neither VEGF/TP expression nor microvessel count contributed to prognostic estimates. CONCLUSIONS: VEGF and TP may cooperatively promote angiogenesis in endometrial cancer, but these expressions may have limited additional prognostic value.

Adult↗
PubMed1999

Combination of automatic HPLC-RIA method for determination of estrone and estradiol in serum.

We developed a highly sensitive assay for estrone and 17 beta-estradiol in serum. Estrone and 17 beta-estradiol, obtained by solid-phase extraction using a Sep pak tC18 cartridge, were purified by high-performance liquid chromatography (HPLC). Quantitation of estrone and 17 beta-estradiol were carried out by radioimmunoassay. Not insignificantly, this automatic system of extraction and HPLC succeeded in analyzing 80 samples a week. Intra-assay coefficients of variation (CV) for estrone and 17 beta-estradiol ranged from 19.5 to 28.7%, and from 8.5 to 13.7%, respectively. The minimum detectable dose for estrone and 17 beta-estradiol were 1.04 pg/ml and 0.64 pg/ml, respectively. The serum levels of 17 beta-estradiol using our method strongly correlated with those by Gas chromatography mass spectrometry (GC-MS). The serum levels of estrone and 17 beta-estradiol in 154 peri- and postmenopausal women were estimated to be between 15 and 27 pg/ml and between 3.5 and 24.0 pg/ml, respectively, while the serum level of 17 beta-estradiol in postmenopausal women, in particular, was estimated to be from 3.5 to 6.3 pg/ml. For postmenopausal women who suffered from vasomotor symptoms, the mean levels of estrone and 17 beta-estradiol at 12 to 18 hours after treatment with daily 0.625 mg conjugated equine estrogen (CEE) and 2.5 mg medroxyprogesterone acetate (MPA) were 135.0 and 21.3 pg/ml at 12 months, respectively. On the other hand, levels of estrone and 17 beta-estradiol at 12 to 18 hours after treatment with CEE and MPA every other day, were 73.4 and 15.3 pg/ml, respectively. These highly sensitive assays for estrone and 17 beta-estradiol are useful in measuring low levels of estrogen in postmenopausal women, and monitoring estrogen levels in women receiving CEE as hormone replacement therapy.

Adult↗
PubMed1998

A negative vitamin D response DNA element in the human parathyroid hormone-related peptide gene binds to vitamin D receptor along with Ku antigen to mediate negative gene regulation by vitamin D.

We found that the human parathyroid hormone-related peptide (hPTHrP) gene contained a DNA element (nVDREhPTHrP) homologous to a negative vitamin D response element in the human parathyroid hormone gene. It bound to vitamin D receptor (VDR) but not retinoic acid Xalpha receptor (RXRalpha) in the human T cell line MT2 cells. VDR binding to this element was confirmed by the Southwestern assay combined with immunodepletion using anti-VDR monoclonal antibody, and this binding activity was repressed by 1,25-dihydroxyvitamin D3. Such a repression was reversed by acid phosphatase treatment, suggesting that 1,25-dihydroxyvitamin D3 phosphorylates VDR to weaken its binding activity to nVDREhPTHrP. In electrophoretic mobility shift assay, we found anti-Ku antigen antibody specifically supershifted the MT2 nuclear proteinnVDREhPTHrP complex. The nVDREhPTHrP-bearing reporter plasmid produced vitamin D-dependent inhibition of the reporter activity in MT2 cells, which was markedly masked by the introduction of the Ku antigen expression vector in the antisense orientation. On the other hand, such a procedure did not perturb the vitamin D response element-mediated gene stimulation by vitamin D. These results indicate that nVDREhPTHrP interacts with Ku antigen in addition to VDR to mediate gene suppression by vitamin D.

Antigens, Nuclear↗
PubMed1998

Urinary excretion of aquaporin-2 in term and preterm infants.

Aquaporin-2 (AQP-2) is a vasopressin-regulated water channel of the renal collecting duct and is excreted in human urine. We measured the urinary excretion of AQP-2 by radioimmunoassay in 14 term and 12 preterm infants aged 1 month. Excretion of AQP-2 was low compared with adults, and correlated significantly with urine osmolality in preterm infants. Our results demonstrate that AQP-2 water channels are expressed in the renal collecting duct of both term and preterm infants.

Aquaporin 2↗
PubMed1998

Brief antecedent ischemia attenuates platelet-mediated thrombosis in damaged and stenotic canine coronary arteries: role of adenosine.

BACKGROUND: Recent studies suggest that patients with angina before myocardial infarction exhibit improved recovery of coronary perfusion after thrombolysis by an as-yet-unknown mechanism. We therefore proposed that brief antecedent ischemia/reperfusion may, via release of adenosine, improve vessel patency in damaged and stenotic coronary arteries. METHODS AND RESULTS: Anesthetized dogs underwent coronary injury + stenosis, resulting in repeated cyclic variations in coronary blood flow (CFVs) caused by the formation/dislodgment of platelet-rich thrombi. Vessel patency was assessed for 3 hours after stenosis by quantification of the nadir of the CFVs, duration of total thrombotic occlusion (flow=0), and area of the flow-time profile (expressed as percent of baseline flow x 180 minutes). In protocol 1, dogs received 10 minutes of coronary occlusion + 10 minutes of reflow or a comparable 20-minute control period before injury + stenosis. The median nadir of the CFVs was higher (4.0 versus 0.3 mL/min), median zero flow duration per 30-minute time interval was shorter (0.4 versus 15.1 minutes), and mean percent flow-time area was greater (54+/-8% versus 28+/-9%) in dogs that received antecedent ischemia versus controls (P<.05). These benefits of antecedent ischemia/reperfusion were largely mimicked by a 10-minute intracoronary adenosine infusion (400 microg/min) in lieu of brief ischemia (protocol 2) and were abolished by administration of the adenosine A1/A2 receptor antagonist PD 115,199 (3 mg/kg i.v.) before brief antecedent coronary occlusion (protocol 3). CONCLUSIONS: Brief antecedent ischemia attenuates subsequent platelet-mediated thrombosis in damaged and stenotic canine coronary arteries, due, in large part, to an adenosine-mediated mechanism.

Adenosine↗
PubMed1998

Anionic amphiphile-independent activation of the phagocyte NADPH oxidase in a cell-free system by p47phox and p67phox, both in C terminally truncated forms. Implication for regulatory Src homology 3 domain-mediated interactions.

Anionic amphiphiles, such as arachidonate, activate the superoxide-producing phagocyte NADPH oxidase in a cell-free system with human neutrophil membrane, which contains cytochrome b558 comprising gp91(phox) and p22(phox), and three cytosolic proteins: p47(phox) and p67(phox), each harboring two SH3 domains, and the small GTPase Rac. Here we show that, even without the amphiphiles, the oxidase is activated in vitro by a C terminally truncated p47(phox), retaining the N-terminal and the two SH3 domains, and the N terminus of p67(phox). When either truncated p47(phox) or p67(phox) is replaced by the respective full-length one, the activation absolutely requires the amphiphiles. The results indicate that both p47(phox) and p67(phox) are the primary targets of the amphiphiles, and that their C-terminal regions play negative regulatory roles. We also find that the truncated p47(phox), but not the full-length one, can bind to p22(phox), a binding required for the oxidase activation. The N-terminal SH3 domain of p47(phox) is responsible for the binding not only to p22(phox), but also to the p47(phox) C terminus. Thus the SH3 domain is accessible in the active p47(phox), but is normally masked in the full-length one probably via intramolecularly interacting with the C terminus. The present findings support our previous proposal of regulatory SH3 domain-mediated interactions.

Cell Membrane↗
PubMed1998

Functional modules and expression of mouse p40(phox) and p67(phox), SH3-domain-containing proteins involved in the phagocyte NADPH oxidase complex.

The phagocyte NADPH oxidase is activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants. The formation of the active oxidase complex at the membrane requires translocation of the Rac GTPase and two specialized cytosolic proteins that harbor SH3 domains, p67phox and p47phox. Another SH3-domain-containing protein p40phox, which is constitutively associated with p67phox in phagocytes, also enters the complex upon cell stimulation. Here we describe how we cloned mouse cDNAs encoding p40phox and its partner in phagocytes, p67phox. Both p40phox and p67phox comprise several protein-binding modules that are structurally and functionally well conserved between mouse and human, indicating their nature as adaptor proteins. We have also systematically investigated expression of the gene for p40phox in comparison with those for p67phox and p47phox. Distributions of the mRNAs for the three proteins among tissues are similar, with the most abundant expression in the spleen. The messages are abundant not only in phagocytic cells, but also in B cell lineage. The p40phox gene, but not the other two, is expressed in some types of cells such as plasma cells and T lymphocytes. Furthermore, in situ hybridization analysis shows that the p40phox mRNA is distributed in neuronal cells of mouse brain, providing evidence that one of the genes for the specialized oxidase factors is expressed in neurons. These observations raise the possibility that the adaptor protein p40phox plays a heretofore unsuspected role via interacting with other proteins in the cells that do not express p67phox or p47phox.

Amino Acid Sequence↗
PubMed1998

The PC motif: a novel and evolutionarily conserved sequence involved in interaction between p40phox and p67phox, SH3 domain-containing cytosolic factors of the phagocyte NADPH oxidase.

The superoxide-generating NADPH oxidase, dormant in resting phagocytes, is activated during phagocytosis following assembly of the membrane-integrated protein cytochrome b558 and cytosolic factors. Among the latter are the three proteins containing Src homology 3 (SH3) domains, p67phox, p47phox and p40phox. While the first two factors are indispensable for the activity, p40phox is tightly associated with p67phox in resting cells and is suggested to have some modulatory role. Here we describe a systematic analysis of the interaction between p40phox and p67phox using the yeast two-hybrid system and in vitro binding assays with recombinant proteins. Both methods unequivocally showed that the minimum requirements for stable interaction are the C-terminal region of p40phox and the region between the two SH3 domains of p67phox. This interaction is maintained even in the presence of anionic amphiphiles used for the activation of the NADPH oxidase, raising a possibility that it mediates constitutive association of the two factors in both resting and activated cells. The C-terminal region of p40phox responsible for the interaction contains a characteristic stretch of amino acids designated as the PC motif, that also exists in other signal-transducing proteins from yeast to human. Intensive site-directed mutagenesis to the motif in p40phox revealed that it plays a critical role in the binding to p67phox. Thus the PC motif appears to represent a novel module for protein-protein interaction used in a variety of signaling pathways.

Amino Acid Sequence↗
PubMed1998

Immunohistochemical expression of thymidine phosphorylase in human endometrial cancer.

OBJECTIVE: To investigate correlations between the expression of thymidine phosphorylase (TP) by endometrial cancer cells and the density of microvessels within the tumor, the clinicopathologic features, and the prognosis. METHODS: We examined tumor specimens obtained from 46 patients with endometrial cancer (9 FIGO stage IA, 16 stage IB, 8 stage IC, 1 stage IIA, 6 stage IIB, and 6 stage IIIC). The cellular expression of TP and the intratumoral density of microvessels were determined by immunohistochemistry using monoclonal antibodies to TP and factor VIII-related antigen, respectively. We investigated the relationship between the cellular expression of TP and the following factors: clinicopathologic features (menopausal status, histologic type, tumor size, histologic grade, myometrial invasion, cervical invasion, and metastasis), the microvessel count, and the disease-free survival period. RESULTS: Of the 46 tumors, 19 (41%) were TP-positive. The microvessel count was significantly higher in TP-positive tumors than in TP-negative tumors (P = 0.01, Mann-Whitney U test). There was no significant correlation between TP expression and clinicopathologic features, and there was no significant difference in the disease-free survival period between patients with TP-positive tumors and patients with TP-negative tumors. CONCLUSION: TP expression was not correlated with clinicopathologic features or prognosis, but was associated with an increased density of microvessels in endometrial cancer. These findings suggest that TP may play an important role in angiogenesis and may be involved in the tumorigenesis of endometrial cancer.

Adult↗
PubMed1998

A multivariate logistic regression analysis in predicting malignancy for patients with ovarian tumors.

OBJECTIVE: Our objective was to improve the preoperative diagnosis of ovarian malignancy using a multivariate logistic regression analysis on the basis of demographic, serologic, gray-scale morphological, and Doppler variables. METHODS: One hundred seventy-one patients with ovarian tumors (120 benign, 51 malignant including 9 tumors of low malignant potential) were studied with transvaginal B-mode, color, and pulsed Doppler ultrasonography before surgery. Based on the gray-scale ultrasound imaging, each tumor was classified as a unilocular cyst, multilocular cyst, unilocular cyst with solid parts, multilocular cyst with solid parts, or solid tumor. Intratumoral blood flow velocity waveforms were recorded on all tumors except unilocular cyst and were evaluated for resistance index (RI) and peak systolic velocity (PSV). Serum CA 125 levels were also measured. RESULTS: Twenty tumors were unilocular cysts and were all benign. Seventy tumors including all unilocular cysts which showed no flows were all benign. The remaining 101 tumors (50 benign, 51 malignant including 9 tumors of low malignant potential) presented intratumoral blood flows. Univariate and multivariate logistic regression analyses were conducted to identify variables predictive of ovarian malignancy in these 101 tumors. The variables included age, menstrual state, serum CA 125 levels, B-mode classification, RI, and PSV. In univariate analysis, menopause, the positivity of CA 125 (> or = 35 U/ml), and PSV larger than or equal to 10.4 cm/s were found to be significantly associated with malignant tumors. The PSV value of 10.4 cm/s was the median in benign tumors. Multivariate analysis showed that serum CA 125 levels (> or = 35 U/ml) (P = 0.002) and PSV (> or = 10.4 cm/s) (P < 0.001) were to be independent predictors of malignancy. CONCLUSION: These results suggest that intratumoral PSV is the strongest means of differentiating benign from malignant ovarian tumors with suspicious gray-scale ultrasonographic findings.

Adolescent↗
PubMed1998

Bovine lactoferrin and Lactoferricin inhibit tumor metastasis in mice.

The effect of a bovine milk protein, lactoferrin (bLf), and a pepsin-generated peptide of bLf, lactoferricin (Lfcin-B), on inhibition of tumor metastasis produced by highly metastatic murine tumor cells, B16-BL6 melanoma and L5178Y-ML25 lymphoma cells, was examined in experimental and spontaneous metastasis models using syngeneic mice. The subcutaneous (s.c.) administration of bovine apo-lactoferrin (apo-bLf) and Lfcin-B 1 day after tumor inoculation significantly inhibited liver and spleen metastasis of L5178Y-ML25 cells and lung metastasis of B16-BL6 cells, whereas human apo-lactoferrin (apo-hLf) and bovine holo-lactoferrin (holo-Lf) at the dose of 1 mg/mouse did not. Furthermore, both apo-bLf and Lfcin-B, but not apo-hLf and holo-bLf, inhibited the number of tumor-induced blood vessels and suppressed tumor growth on day 8 after tumor inoculations in an in vivo model. However, in a long-term analysis of tumor growth for up to 21 days after tumor inoculation, single administration of apo-bLf significantly suppressed the growth of B16-BL6 cells throughout the examination period, but Lfcin-B showed inhibitory activity only during the early period (8 days). In spontaneous metastasis model, multiple administration of both apo-bLf and Lfcin-B significantly inhibited lung metastasis of B16-BL6 cells, however it was only apo-bLf that exhibited the inhibitory effect of tumor growth at the time of primary tumor amputation (on day 21) after tumor inoculation. The results suggest that apo-bLf and Lfcin-B inhibit tumor metastasis through different mechanisms, and that the inhibitory activity of bLf on tumor metastasis may be related to the property of iron (Fe3+)-saturation.

Animals↗
PubMed1998

Laminin, a major basement membrane component of the blood vessel, as a negative regulator of osteoclastogenesis.

Laminin, the major basement membrane glycoprotein of the blood vessel, inducing many cellular responses, inhibited the differentiation of osteoclasts in a rat bone marrow culture system when immobilized on the surface of the culture wells, showing that laminin acts as a negative regulator of osteoclast differentiation in a nonsolubilized form. Laminin inhibited the process of preosteoclast formation from early progenitor cells in bone marrow. This laminin-mediated inhibition of osteoclastogenesis was blocked by the addition of laminin fragment YIGSR, indicating that the inhibitory effect of laminin was mediated via laminin receptors. This finding suggests a significant role of basement membrane laminin of the blood vessels as a negative regulator of osteoclastogenesis.

Acid Phosphatase↗
PubMed1998

Contribution of the T cell receptor BJ gene to recognition of the P91A tumor antigen in DBA/2 mice.

To understand specific immune responses against a tumor, it is important to characterize T cells that recognize the tumor antigen. The mouse P91A antigen is one of the well-defined tumor antigens that is expressed on the P911 cell line, and T cells responding to the antigen in DBA/2 mice were reported to be restricted to BV8S2/S3 families in their T cell receptor (TCR) BV gene usage. We have further characterized the P91A-responding T cells in DBA/2 mice, focusing on TCR BJ gene usage and using the polymerase chain reaction/enzyme-linked immunosorbent assay and DNA sequencing studies of their third complementarity-determining (CDR3) regions. As a result, T cells with cytotoxic activity to the P91A antigen, induced from murine spleen cells both in vivo and in vitro, showed predominant use of the BJ2S1 gene segment in both BV8S2 and BV8S3 T cells compared to unmanipulated murine spleen cells. Sequencing studies of the CDR3 regions in the BV8S3 T cells revealed clonal expansion of T cells with the BV8S3-BJ2S1 combination in two of three DBA/2 mice tested. In the remaining mouse, clonal expansion was not detected despite predominant use of the BJ2S1 segment by these T cells. These data suggest that P91A-recognizing T cells would predominantly use the BV8S2/S3-BJ2S1 combination. Analysis of T cells with these TCR BV-BJ gene combinations may contribute to the evaluation, monitoring and development of a T-cell-mediated immunotherapeutic strategy.

Animals↗
PubMed1998

Spontaneous perforation of the rectum with possible stercoral etiology: report of a case and review of the literature.

Stercoral perforation of the colon or rectum is a rare cause of acute abdomen, with fewer than 70 cases documented in the literature. We report herein the case of a 60-year-old man who presented with anuria and epigastric pain with physical signs of peritonitis. An abdominal X-ray showed bilateral subphrenic free air accumulation, and an emergency laparotomy subsequently revealed perforation of the rectum, suggestive of a stercoral cause, which was treated by simple closure after debridement. Following an uneventful postoperative course, he was discharged from the hospital 3 weeks after his operation and is now doing well without having suffered any further gastrointestinal problems. The clinical features, diagnosis, and treatment of the disease are reviewed following the presentation of this case. Surgeons should be aware of the possibility of this fatal disease, despite its rare incidence. Furthermore, it is important to recognize the condition at an early stage because it has a significantly high mortality if not treated early. Conversely, the surgical outcome is satisfactory provided surgery is performed in due time.

Debridement↗