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Hideki Kawai

Publications and source records attributed to Hideki Kawai.

17 recordsLinked to original sources
PubMed2026

Impact of estimated total blood volume on NT-proBNP response to angiotensin receptor-neprilysin inhibition in acute heart failure: Insights from the PREMIER study.

BACKGROUND: Sacubitril/valsartan (Sac/Val) reduces N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in acute heart failure (AHF), particularly in patients with reduced ejection fraction. However, whether estimated total blood volume (TBV), calculated using anthropometric equations, is associated with heterogeneity in biomarker response remains uncertain. METHODS: This post hoc exploratory sub-analysis of the PREMIER randomized trial evaluated whether baseline estimated TBV was associated with heterogeneity in NT-proBNP reduction after Sac/Val compared with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) therapy. Estimated TBV was calculated using validated anthropometric equations and dichotomized at the median (4.05 L). Patients were further stratified by left ventricular ejection fraction (LVEF <40% vs &#x2265;40%). The primary endpoint was the proportional change in NT-proBNP from baseline to Week 8. RESULTS: Among 376 patients, 372 with baseline estimated TBV data were analyzed. In the high TBV group, Sac/Val was associated with greater NT-proBNP reduction than ACEI/ARB (-56% vs -32%; ratio of change, 0.67; 95% confidence interval, 0.53-0.84; P = .001), whereas no significant difference was observed in the low TBV group (P for heterogeneity = 0.063). In patients with LVEF <40%, Sac/Val was associated with greater NT-proBNP reduction in both TBV groups. In patients with LVEF &#x2265;40%, Sac/Val was associated with greater NT-proBNP reduction in the high TBV group, whereas the point estimate in the low TBV group numerically favored ACEI/ARB. CONCLUSIONS: In this exploratory post hoc analysis, higher estimated TBV was associated with greater NT-proBNP reduction after Sac/Val, particularly among patients with LVEF &#x2265;40%. These findings are hypothesis-generating and require external validation. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05164653; Japan Registry of Clinical Trials, jRCTs021210046.

Humans↗
PubMed2006

Chain length dependence of the interactions of bisquaternary ligands with the Torpedo nicotinic acetylcholine receptor.

The interactions of a series of bisholine esters [(CH3)3N+CH(2)CH2OCO-(CH2)n-COOCH2CH2N+(CH3)3] with the Torpedo nicotinic acetylcholine receptor have been investigated. In equilibrium binding studies, [3H]-suberyldicholine (n=6) binds to an equivalent number of sites as [3H]-acetylcholine and with similar affinity (KD approximately 15 nM). In competition studies, all bischoline esters examined displaced both radioligands in an apparently simple competitive manner. Estimated dissociation constants (KI) showed clear chain length dependence. Short chain molecules (n 6) had high affinity similar to suberyldicholine. Functional responses were measured by either rapid flux techniques using Torpedo membrane vesicles or voltage-clamp analyses of recombinant receptors expressed in Xenopus oocytes. Both approaches revealed that suberyldicholine (EC50 approximately 3.4 microM) is 14-25-fold more potent than acetylcholine. However, suberyldicholine elicited only about 45% of the maximum response of the natural ligand, i.e., it is a partial agonist. The potency of this bischoline series increased with chain length. Whereas the shorter ligands (n or=4) had similar (or higher) potency to suberyldicholine. Ligand efficacy had an approximately bell-shaped dependence on chain length and compounds where n or=8 were very poor partial agonists. Based on estimates of interonium distances, we suggest that bisquaternary ligands can interact with multiple binding sites on the nAChR and, depending on the conformational state of the receptor, these sites are 15-20A apart.

Acetylcholine↗
PubMed2006

Tumor-derived TGFbeta-1 induces dendritic cell apoptosis in the sentinel lymph node.

Lymphatic flux from a primary tumor initially flows into a tumor-draining lymph node (LN), the so-called sentinel LN (SLN). Carried by the lymph fluid are a variety of mediators produced by the tumor that can influence immune responses within the SLN, making it a good model with which to investigate tumor-related immunology. For instance, dendritic cell (DC) numbers are reduced in SLNs from melanoma and breast cancer patients. In the present study, we investigated the mechanism by which DC numbers were reduced within SLNs from patients with non-small cell lung cancer. We found that the incidence of apoptosis among DCs was higher in SLNs than in non-SLNs, as were levels of TGFbeta-1. In contrast, levels of TGFbeta-1 mRNA did not differ between SLNs and non-SLNs, but were 30 times higher in tumors than in either LN type. In vitro, incubation for 2 days with TGFbeta-1 induced apoptosis among both cultured DCs and DCs acutely isolated from normal thoracic LNs, effects that were blocked by the TGFbeta-1 inhibitor DAN/Fc chimera. Taken together, these results suggest that tumor-derived TGFbeta-1 induces immunosuppression within SLNs before the movement of tumor cells into the SLNs, thereby facilitating metastasis within those nodes.

Apoptosis↗
PubMed2006

Giant cell tumor of the sternum.

A primary giant cell tumor (GCT) originating from the sternum is extremely rare. We report a case of a GCT originating from the sternum in a 45-year-old man who was referred to us for a mass in the anterior chest wall that had been growing slowly. Computed tomography revealed a soft tissue mass involving a large osteolytic and destructive lesion of the sternum body. Subtotal sternectomy and reconstruction with methylmethacrylate were performed. The tumor was 8.5 x 4.5 x 2.5cm, and the histopathological examination confirmed GCT. Radical wide resection of primary sternum tumors and reconstruction with an appropriately rigid prosthetic material are necessary to minimize local recurrence.

Bone Neoplasms↗
PubMed2005

Estrogen receptor alpha and beta are prognostic factors in non-small cell lung cancer.

PURPOSE: Estrogen receptor-alpha (ER-alpha) and -beta (ER-beta) play important roles in the carcinogenesis of breast tumors. Similarly, there have been several reports of ER expression in lung cancers, but the results have not been consistent, and the receptors' prognostic value remains unclear. Our goal was to investigate ER expression in non-small cell lung cancer (NSCLC) and to assess whether their expression correlates with prognosis. EXPERIMENTAL DESIGN: ER expression was examined using immunohistochemical methods with sections from 132 resected NSCLC specimens. Kaplan-Meier survival curves were analyzed to determine the significance of ER expression in the prognosis of NSCLC patients. RESULTS: ER-alpha was detected in the cytoplasm of 73% of the specimens analyzed, whereas ER-beta was detected in the nucleus of 51%. ER-alpha expression correlated with poorer overall survival (P < 0.001), as did the absence of ER-beta expression (P = 0.048). Likewise, at histopathologic stage I, ER-alpha expression (P = 0.028) or the absence of ER-beta (P = 0.037) correlated with a poorer prognosis, and ER-alpha(+)ER-beta(-) patients had a significantly worse prognosis than ER-alpha(-)ER-beta(+) patients (P = 0.00007). Multivariate Cox regression analysis revealed the absence of ER-beta to be an independent factor predictive of poor disease outcome (hazard ratio, 1.9; 95% confidence interval, 1.1-3.4; P = 0.0264). CONCLUSIONS: ER-alpha expression and the absence of ER-beta expression are associated with a poorer prognosis among NSCLC patients. In particular, the absence of ER-beta could serve as a marker identifying patients at high risk even at an early clinical stage.

Adult↗
PubMed2005

Nocturnal hypoxemia after lobectomy for lung cancer.

BACKGROUND: Although nocturnal episodic hypoxemia after major abdominal surgery has been reported, the condition of nocturnal oxygen saturation after lung surgery is largely unknown. We evaluated nocturnal oxygen saturation during the perioperative period after lobectomy for lung cancer. This study also compared the postoperative course of nocturnal oxygen saturation after standard lobectomy with posterolateral thoracotomy and lobectomy with video-assisted thoracic surgery. METHODS: Twenty-one consecutive patients who had undergone lobectomy for lung cancer by either the posterolateral thoracotomy approach (n = 11) or the video-assisted thoracic surgery approach (n = 10) were studied. Fifteen consecutive patients who had undergone gastrectomy for gastric cancer were also studied. Overnight oxygen saturation was measured on the third and 14th postoperative days. RESULTS: The frequency of hypoxemia in the lobectomy group was higher than that in the gastrectomy group (p = 0.043). The frequency of hypoxemia on the 14th postoperative day (p = 0.009) and the severity of hypoxemia on the third and 14th postoperative days (p = 0.041, 0.046) for the video-assisted thoracic surgery approach were lower than those for the posterolateral thoracotomy approach. In terms of mean arterial oxygen saturation, heart rate, forced vital capacity, and forced expiratory volume in 1 second, there were no statistically significant differences between the video-assisted thoracic surgery group and the posterolateral thoracotomy group. CONCLUSIONS: Video-assisted thoracic surgery lobectomy was superior in terms of early postoperative nocturnal oxygen saturation. We conclude that the video-assisted thoracic surgery approach is more beneficial than the posterolateral thoracotomy approach for high-risk patients.

Aged↗
PubMed2005

Spectral integration in auditory cortex: mechanisms and modulation.

Auditory cortex contributes to the processing and perception of spectrotemporally complex stimuli. However, the mechanisms by which this is accomplished are not well understood. In this review, we examine evidence that single cortical neurons receive input covering much of the audible spectrum. We then propose an anatomical framework by which spectral information converges on single neurons in primary auditory cortex, via a combination of thalamocortical and intracortical "horizontal" pathways. By its nature, the framework confers sensitivity to specific, spectrotemporally complex stimuli. Finally, to address how spectral integration can be regulated, we show how one neuromodulator, acetylcholine, could act within the hypothesized framework to alter integration in single neurons. The results of these studies promote a cellular understanding of information processing in auditory cortex.

Acetylcholine↗
PubMed2005

Intraoperative detection of lymph node micrometastasis with flow cytometry in non-small cell lung cancer.

OBJECTIVE: We sought to determine whether cytokeratin-positive cells can be detected as markers of lymph node metastasis by using flow cytometry within a time frame suitable for intraoperative decision making in non-small cell lung cancer. METHODS: Five lymph nodes from each of 20 patients with non-small cell lung cancer were randomly selected for study. Each node was divided longitudinally into 3 pieces: one piece for flow cytometry, one for immunohistochemical staining, and the last for conventional hematoxylin and eosin staining. In both flow cytometry and immunohistochemistry, cytokeratin-positive cells were detected with the fluorescein isothiocyanate-conjugated anti-cytokeratin antibody AE1/AE3. RESULTS: Cytokeratin-positive nodes were detected by means of flow cytometry within 40 minutes. Eight (8%) of the 100 lymph nodes from 4 (20%) of the 20 patients were deemed positive for metastasis on the basis of conventional histologic examination. By contrast, 33 (33%) lymph nodes from 13 (65%) patients were deemed positive on the basis of immunohistochemical cytokeratin staining, and 38 (38%) lymph nodes from 14 (70%) patients were deemed positive on the basis of flow cytometric cytokeratin-positive cell detection. All nodes deemed positive for metastasis on the basis of conventional and immunohistochemical methods were also positive on flow cytometry. CONCLUSIONS: Flow cytometry enables rapid intraoperative diagnosis of nodal metastasis in patients with non-small cell lung cancer. Flow cytometric detection of cytokeratin-positive cells within lymph nodes correlates with their immunohistochemical detection, and its level of sensitivity is greater than that of conventional histologic staining and about equal to that of immunohistochemical staining.

Biomarkers, Tumor↗
PubMed2004

Visual experience regulates transient expression and dendritic localization of fragile X mental retardation protein.

Fragile X syndrome is the most common form of inherited mental retardation and is caused by the loss of function of the Fragile X mental retardation protein (FMRP). FMRP is an RNA binding protein thought to play a key role in protein synthesis-dependent synaptic plasticity. The regulation of FMRP expression itself is also likely to be an important control point in this process. Here we used dark-reared/light-exposed rats to determine the role of experience in regulating FMRP levels in the visual cortex. We find that FMRP levels increase in the cell bodies and dendrites of visual cortical neurons after as little as 15 min of light exposure. Remarkably, FMRP expression in these neurons returns to baseline levels by 30 min of light exposure. These changes were post-transcriptional because the FMR1 mRNA levels remained constant over this time period. A transient increase in FMRP levels was also observed in synaptic fractions prepared from visual cortices of light-exposed animals. In contrast, alpha-calcium/calmodulin-dependent kinase II expression showed a sustained upregulation under these conditions. Finally, the increase in FMRP expression was inhibited by blockade of NMDA receptors. This tight temporal-spatial regulation suggests that FMRP plays a dynamic role in a distinct epoch of experience-dependent synaptic plasticity.

Animals↗
PubMed2003

Overexpression of histone deacetylase HDAC1 modulates breast cancer progression by negative regulation of estrogen receptor alpha.

The interaction between 17beta-estradiol and estrogen receptor alpha (ER-alpha) plays an important role in breast carcinogenesis and breast cancer treatment. ER-alpha is a critical growth regulatory gene in breast cancer and its expression level is tightly linked to the prognosis and treatment outcomes of breast cancer patients. Loss of ER-alpha expression in breast epithelial cells is critical for breast cancer progression. The underlying molecular mechanisms for this loss, however, are poorly defined. Histone deacetylases (HDACs) are implicated in the alteration of chromatin assembly and tumorigenesis. We show that histone deacetylase 1 (HDAC1) interacts with ER-alpha in vitro and in vivo and suppresses ER-alpha transcription activity. The interaction of HDAC1 with ER-alpha was mediated by the AF-2 and DBD domains of ER-alpha. We observed an endogenous interaction of HDAC1 with ER-alpha in breast cancer cells, which was decreased in the presence of estrogen. Interestingly, overexpression of HDAC1 in stable transfected MCF-7 clones induced loss of ER-alpha and significantly increased cell proliferation and colony formation, as compared to the control MCF-7 cells, whereas treatment of stable MCF-7 clones with the HDAC specific inhibitor trichostatin A (TSA) induced re-expression of ER-alpha mRNA and protein. Our findings strongly suggest that HDAC1 affects breast cancer progression by promoting cellular proliferation in association with a reduction in both ER-alpha protein expression and transcriptional activity. Thus, HDAC1 may be a potential target for therapeutic intervention in the treatment of a subset of ER-negative breast cancers.

Breast Neoplasms↗
PubMed2003

Large-scale production of genetically engineered CYP3A4 in E. coli: application of a jarfermenter.

To produce a large amount of CYP3A4, we applied a jarfermenter (ABLE, BMJ-PI or BMS-PI) to culture the genetically engineered E. coli cells harboring CYP3A4 along with NADPH-cytochrome P450 reductase (OR). The jarfermenter is a stirred bacterial culture vessel in which the pH, the dissolved oxygen (DO) and the temperature of a culture medium can be controlled. The expression of CYP3A4 in E. coli cells in the 500 mL of culture medium contained in the BMJ-PI (1 L vessel) (JFM-1) was examined by altering the parameters mentioned above. The highest expression of CYP3A4 in E. coli cells was attained when cultured at pH 6.0, at 30 degrees C under the DO of 0.1 ppm. The incubation was performed 18 hr after the addition of 1.5 mM isopropyl beta-D(-)-thiogalactopyranoside. The expression levels of CYP3A4 and the OR in the membrane fraction of E. coli cells were 267 nmol/L culture and 552 units/L culture, respectively. The CYP3A4 level was about three times higher than that obtained by incubation in a 500 mL flask (100 mL of medium) (84 nmol/L culture). The testosterone 6beta-hydroxylase activity of CYP3A4 expressed in the membrane fraction of E. coli obtained with the JFM-1 was examined. The apparent K(m) and V(max) values were 66.4 microM and 57.8 nmol/min/nmol CYP, respectively. Expecting the mass production of the CYP3A4 by a culture of E. coli, the possibility of a scale up of the culture with the BMS-PI (10 L vessel) (JFM-10) was examined. The optimal culture condition to achieve the highest expression of CYP3A4 with JFM-1 was employed. The expression levels of CYP3A4 and the OR obtained with JFM-1 and JFM-10 were almost equal. The total level of CYP3A4 obtained by using JFM-10 (5 L of medium) was calculated to be about 1.4 mumol. Based on these results, we confirm that the jarfermenter is a useful tool to produce large amounts of CYP3A4.

Journal Article↗
PubMed2002

Direct interaction between BRCA1 and the estrogen receptor regulates vascular endothelial growth factor (VEGF) transcription and secretion in breast cancer cells.

Mutational inactivation of BRCA1 confers increased risk for breast cancer. However, the underlying basis for the breast tissue-restricted, tumor-suppressive properties of BRCA1 remains poorly defined. Here, we show that BRCA1 and the estrogen receptor alpha (ER-alpha) modulated vascular endothelial growth factor (VEGF) gene transcription and secretion in breast cancer cells. ER-alpha interacted in vitro and in vivo with BRCA1, and this interaction was mediated by the AF-2 domain of ER-alpha and two domains of BRCA1, the amino-acid residues 1-306 and 428-683. Endogenous interaction of ER-alpha with BRCA1 was observed in normal MCF-10A breast epithelial cells and in breast cancer cells (MCF-7 and T47D), and this interaction was significantly reduced in the presence of estrogen. Furthermore, ER-alpha induced activation of VEGF gene transcription, using human VEGF promoter-luciferase reporter constructs. The AF-2 domain of ER-alpha was also shown to induce VEGF gene transcription activation similar to that obtained with the full-length ER-alpha. However, in the presence of BRCA1, VEGF gene transcription activation and VEGF protein secretion were significantly inhibited in a dose-dependent manner. The BRCA1 domain of 1-683 amino acid residues was required for this inhibition of VEGF gene transcription activation. Three mutated forms of BRCA1 (A1708E, M1775R and Y1853X), that have been identified in familial breast cancers, failed to associate with ER-alpha and to suppress VEGF promoter activity and VEGF protein secretion. Overexpression of wild-type BRCA1 in HCC-1937 breast cancer cells that lack endogenous functional BRCA1 significantly reduced VEGF secretion in these cells. These results demonstrate a novel pathogenic mechanism whereby mutations in BRCA1, via their interaction with ER-alpha, could promote tumorigenesis through the hormonal regulation of mammary epithelial cell proliferation and impaired VEGF function, which may lead to cancer growth and angiogenesis.

BRCA1 Protein↗
PubMed2002

Nicotinic alpha 7 receptor clusters on hippocampal GABAergic neurons: regulation by synaptic activity and neurotrophins.

Nicotinic acetylcholine receptors containing the alpha7 gene product are expressed at substantial levels in the hippocampus. Because of their specific locations and their high relative calcium permeability, the receptors not only mediate cholinergic transmission in the hippocampus but also influence signaling at noncholinergic synapses. We have used fluorescently labeled alpha-bungarotoxin to image alpha7-containing receptors on hippocampal neurons and to examine their regulation in culture. The highest levels of staining for such receptors were most commonly found on GABAergic interneurons identified immunohistochemically. The receptors were distributed in clusters on the soma and dendrites and were localized in part at GABAergic synapses. A 3 d blockade of electrical activity with tetrodotoxin or NMDA receptors with APV dramatically reduced the proportion of GABAergic neurons expressing high levels of receptor staining and reduced the mean number of distinguishable receptor clusters on individual neurons. Blockade of either GABA(A) receptors with bicuculline or nicotinic receptors with d-tubocurarine had no effect, although exposure to nicotine could increase the level of receptor staining. Anti-BDNF and anti-NGF antibodies produced decrements equivalent to those of tetrodotoxin and APV, whereas addition of BDNF and NGF each increased staining levels and increased the number of distinguishable receptor clusters on GABAergic neurons. The exogenous neurotrophins could not, however, overcome the effects of either tetrodotoxin or APV. The results indicate that both NMDA receptor activation and the neurotrophins BDNF and NGF are necessary to sustain the distribution patterns of alpha7-containing nicotinic receptors on GABAergic hippocampal neurons.

Animals↗
PubMedDate not supplied

Alpha-fetoprotein-producing esophageal carcinoma: a case report.

We report herein a rare case of esophageal carcinoma producing alpha-fetoprotein (AFP). A 69-year-old man presenting elevated AFP was admitted in order to investigate its origin, which several liver examinations done before admission had not revealed. At admission, his serum AFP was 76.9 ng/ml whereas other tumor markers were within normal range. As the patient complained of mild swallowing disturbance, gastrointestinal examinations were performed, and an esophageal carcinoma was found at the esophagogastric junction. The patient underwent subtotal esophagectomy and the esophagus was reconstructed by gastric tube. The postoperative course was uneventful and the serum AFP level normalized immediately after the operation. Histopathological examination demonstrated the tumor to be poorly-differentiated adenosquamous carcinoma, which contained scattered adenocarcinoma composed of clear cells positive to AFP by an immunohistochemical stain. The patient has been well for six months after the surgery without any sign of recurrence.

Aged↗
PubMedDate not supplied

Bronchoscopic treatment with argon plasma coagulation for recurrent typical carcinoids: report of a case.

Carcinoid tumors are recognized as a low-grade malignancy. Recurrence of bronchopulmonary typical carcinoids is extremely rare. We herein report a case of recurrent multiple intraluminal bronchial typical carcinoids that were successfully removed using argon plasma coagulation by bronchoscopic approach. A 48-year-old man, who had undergone resection of a pulmonary typical carcinoid 8 years previously, suffered from a productive cough and hemosputum for a month. Bronchoscopic examination revealed multiple intraluminal bronchial polypoid tumors. Based on histopathological findings, we diagnosed recurrence of typical carcinoids. The patient underwent argon plasma coagulation (APC) treatment by bronchoscopic approach several times. APC treatment is considered to be a safer method than conventional bronchoscopic treatment with neodymium-yttrium aluminum garnet (Nd-YAG) laser or electrocautery. After a series of treatments, his symptoms completely improved and no recurrence was found during 10 months of follow-up.

Argon↗
PubMedDate not supplied

Combined overexpression of EGFR and estrogen receptor alpha correlates with a poor outcome in lung cancer.

BACKGROUND: The aim of the present study was to determine the prognostic significance of the combined overexpression of epidermal growth factor receptor (EGFR) and estrogen receptor a (ER-alpha) in non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: An immunohistochemical assessment of EGFR and ER-alpha expression was carried out in tumor specimens from 122 consecutive NSCLC patients after surgery. RESULTS: Of the 122 tumors examined, 57 (46.7%) overexpressed EGFR, 63 (51.6%) overexpressed ER-alpha, while 33 (27%) overexpressed both EGFR and ER-alpha. Univariate analyses showed that the overexpression of EGFR or ER-alpha correlated with the histological grade (p = 0.01 and p = 0.03, respectively) and a poorer prognosis (p = 0.007), while overexpression of ER-alpha also correlated with smoking (p = 0.02). Multivariate analysis showed the combined overexpression of EGFR and ER-alpha to be an independent indicator of poorer prognosis (p = 0.0006). CONCLUSION: The combined overexpression of EGFR and ER-alpha in NCLSC patients is predictive of poor outcome and, thus, represents a valuable prognostic factor.

Adult↗