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E Sato

Publications and source records attributed to E Sato.

At least 91 records · Page 5Linked to original sources
PubMed2000

Molecular cloning and sequencing of the cDNA encoding the feline FcgammaRIIIA (CD16) homologue.

We amplified the cDNA encoding the feline FcgammaRIIIA (CD16) homologue from peripheral blood mononuclear cells by polymerase chain reaction and cloned two forms of FCGR3A cDNA. Sequencing analysis revealed that the open reading frame of feline FCGR3A cDNA consists of 750 or 747 base pairs encoding 250 or 249 amino acid residues, respectively. Comparison of the predicted amino acid sequence of feline FCGR3A cDNA with those of other mammalians' homologues revealed that the extracellular domain has a relatively low homology. However, the cytoplasmic domain contained an 8-amino acid motif, Leu-Phe-Val-Val-Asp-Thr-Gly-Leu, which was considered to interact with an accessory molecule such as the gamma chain of Fc receptors for IgE to form heterodimeric complexes.

Amino Acid Sequence↗
PubMed2000

Expression of thrombomodulin in squamous cell carcinoma of the lung: its relationship to lymph node metastasis and prognosis of the patients.

Thrombomodulin (TM) is a type of thrombin receptor that was identified originally on the endothelium and acts as a natural anticoagulant through converting thrombin from a procoagulant protease to an anticoagulant. We reported previously that TM was also expressed in the squamous epithelium mainly at the intercellular bridges. In this study, we examined TM expression in the primary lesions of 81 patients with squamous cell carcinomas (SCCs) of the lung and in the lymph node metastatic lesions of 39 patients using immunohistochemical methods. The carcinoma tissues expressed TM mainly at the cell-cell boundaries and also in the cytoplasm. When TM expression was compared between the primary and metastatic lesions in the 39 patients who had lymph node metastasis, 26 (67%) showed decreased TM expression, 13 (33%) showed no change, and none (0%) showed an increase in the metastatic lesions. Wilcoxon's signed-rank test indicated that tumor cells that were positive for TM expression were significantly rarer in the metastatic lesions than in the primary tumors (P < 0.0001). The present study also showed that the patients with TM-negative expression in the primary tumors showed significantly poorer survival than those with TM-positive expression, mainly due to distant metastases of poorly-differentiated SCCs with negative TM expression in the primary tumors. These results indicate that the reduction of TM expression seems to play an important role in the metastatic process of lung SCCs.

Adult↗
PubMed2000

Scanning laser ophthalmoscope correlations with biomicroscopic findings and foveal function after macular hole closure.

OBJECTIVE: To investigate the relation between foveal findings and visual function in eyes with a resolved idiopathic macular hole after vitreous surgery. METHODS: We divided 28 eyes with postoperative idiopathic macular hole resolution into 3 groups based on postoperative biomicroscopic foveal findings of complete closure, partial closure, or atrophic closure. To evaluate foveal retinal function, scanning laser ophthalmoscope (SLO) microperimetry was performed preoperatively and 6 months postoperatively. RESULTS: Postoperatively in 18 eyes (64%), the foveal images became normal or almost normal and were classified as having complete closure, 6 eyes (21%) were classified as having partial closure, and 4 eyes (14%) as having atrophic closure. The corresponding visual acuity levels 6 months postoperatively were, respectively, 0.10, 0.35, and 0.64 (P<.01) based on LogMAR analysis. Preoperative SLO microperimetry detected an absolute scotoma at the bottom of all macular holes; postoperatively, the absolute scotoma disappeared in the 18 eyes with complete hole closure, but a relative scotoma was detected in 6 eyes. Of 6 eyes with partial closure, 1 had an absolute scotoma and 5 had a relative scotoma. An absolute scotoma was detected in 4 eyes with atrophic closure. CONCLUSIONS: After macular hole closure, SLO findings correlate both with biomicroscopic findings and foveal function. Better anatomical foveal recovery in eyes after macular hole closure results in better improvement of vision than in eyes in which the foveal anatomical findings are not as good.

Aged↗
PubMed2000

A novel mutation that leads to a congenital factor XI deficiency in a Japanese family.

We have identified a novel mutation leading to a congenital deficiency of the coagulation factor XI (FXI) in a Japanese family. A propositus was a 42-year-old female patient without bleeding tendency. Coagulant activity and the antigen level of FXI in her plasma were below the detectable range. The nucleotide sequences of the FXI gene of this patient were determined by a direct sequence method established in this study. A novel nonsense mutation (CAA; Gly263 --> TAA; stop) was identified in exon 8 of the FXI gene. Her parents are first cousins, and a polymerase chain reaction-restriction-fragment length polymorphism analysis revealed that her parents were heterozygous at this nucleotide position. This patient inherited mutant alleles from her parents and is homozygous at this nucleotide position. The nonsense mutation in the FXI gene is responsible for her deficiency of FXI.

Adult↗
PubMed2000

In situ expression of fibrogenic growth factors and their receptors in biliary atresia: comparison between early and late stages.

Progressive fibrosis, despite successful surgical treatment, is one of the serious complications of biliary atresia. To understand the mechanism of this fibrosis, the in situ expression of fibrogenic growth factors (TGF-beta and PDGF) and their corresponding receptors was studied by immunohistochemistry using frozen sections. The results were compared between the early (n=12) and late (n=6) stages. The early stage was characterized by abundant expression of all ligands and receptors, together with type I procollagen (PC-I). The major cellular sources were activated fibroblasts/myofibroblasts distributed mostly in the portal tracts. Macrophages also expressed all the ligands and the receptors, but to a lesser degree. Bile duct cells strongly expressed TGF-beta RI and RII and PDGF AA and BB, but focally expressed TGF-beta. All of these decreased in the late stage of biliary atresia. These results suggest that TGF-beta and PDGF play important roles in the fibrogenesis of biliary atresia, especially in its early stage, acting either by autocrine or paracrine mechanisms involving activated fibroblasts/myofibroblasts, bile duct cells, and macrophages.

Adult↗
PubMed2000

Analysis of the role of egg integrins in sperm-egg binding and fusion.

Sperm-egg fusion is believed to be mediated via specific molecular interactions. Integrin alpha6beta1 is a strong candidate for a sperm receptor on the egg plasma membrane. However, the ability of the egg integrin alpha6beta1 to interact with molecules on intact sperm has not yet been proven. In this report, possible involvement of integrin alpha6beta1 in sperm-egg interactions was examined by biochemical and immunocytochemical analyses. To identify egg molecules that specifically interact with sperm, we first incubated sperm with biotin-labeled egg surface proteins. Under this condition, solubilized proteins from eggs inhibited sperm-egg fusion. Western blot analysis under reducing conditions indicated that a major-labeled band of 135 kDa bound to sperm. An immunodepletion experiment using the anti-integrin alpha6 antibody GoH3 indicated that the 135 kDa egg surface molecule that bound to sperm was the integrin alpha6 subunit. To investigate the potential involvement of integrin alpha6beta1 in sperm-egg fusion, we next examined the localization of integrin alpha6 and beta1 subunits before and after fertilization by confocal laser microscopy. At an early stage of sperm-egg fusion, the integrin alpha6 and beta1 subunits were accumulated at the sperm binding site. The frequency of cluster formation was closely related to that of sperm-egg fusion, indicating that integrin receptors are accumulated by sperm destined for fusion. Taken together, these results strongly suggest that the integrin alpha6beta1 is involved in sperm-egg binding leading to fusion via direct association of the integrin alpha6 with sperm.

Animals↗
PubMed2000

Elevation of nitrotyrosine and nitrate concentrations in cystic fibrosis sputum.

Nitric oxide (NO) is increased in the exhaled air of some patients with inflammatory lung disorders, but not in others. NO may combine with superoxide to form peroxynitrite, which lowers NO gas concentrations, increases formation of nitrate, and increases nitration of tyrosine residues on proteins. We hypothesized that superoxide released from neutrophils in the lower respiratory tract of cystic fibrosis (CF) results in increased nitrate and nitrotyrosine levels in sputum. In order to test this hypothesis, exhaled NO was collected from 5 stable adult CF subjects and from 5 nonsmoking normal controls. Consistent with previous reports, exhaled NO concentrations were not increased in CF exhaled air (22.6 +/- 1.5 ppb vs. 28.6 +/- 1.5 ppb in normals, P > 0.05). Sputum was collected from 9 adult CF subjects and the same 5 normal controls and evaluated for nitrite, nitrate, and nitrotyrosine. Nitrate and nitrotyrosine levels, but not nitrite, were significantly elevated in CF. Recently, myeloperoxidase has also been implicated as a mechanism of nitrotyrosine formation. Therefore, myeloperoxidase was measured and found to be elevated in the CF sputum (64.2 +/- 35.9 vs. 0.73 +/- 0.16 U/mL, P < 0.001), and was found to correlate with concentrations of nitrotyrosine (r = 0.87, P < 0.05). However, in vitro studies with myeloperoxidase and murine lung epithelial cells did not demonstrate a reduction of NO gas with nitrotyrosine or an increase in nitrate formation. These data demonstrate that nitrate and nitrotyrosine are elevated in the sputa of CF subjects and suggest increased production of NO in the lower respiratory tract of CF patients, despite the relatively low exhaled NO levels. Pediatr Pulmonol. 2000; 30:79-85. Published 2000 Wiley-Liss, Inc.

Adolescent↗
PubMed2000

Molecular and immunological approaches to mammalian fertilization.

By means of hybridoma technology, we obtained six hydriboma cell lines producing monoclonal antibody (mAb) to porcine zona pellucid (ZP), two of which recognizes the steric structure of common antigens between porcine ZP and humans. Furthermore, we have analyzed all or partial structures of N- and O-linked sugar chains of ZP glycprotein from porcine or murine oocytes. Then, we have clarified that beta-galactose and Le(X) residues on ZP played the binding roles to sperm cells in porcine and murine fertilization. We have also succeeded Sp38 cDNA cloning from cDNA library of porcine testis. We found that Sp38 protein bind to porcine ZP2 and expressed in murine and human sperm cells. Corresponding to the presence of major histocompatibility complex (MHC) class II on murine sperm, CD4 on the murine egg plasma membrane was clearly shown by indirect IIF and immunoprecipitation test. Furthermore, the transcriptional expression of CD4/p56(lck) in eggs was confirmed by RT-PCR method. In addition, the p56(lck) associated with CD4 underneath the plasma membrane of eggs was autophosphorylated after cross-linking of CD4 with anti CD4 mAb. The binding between eggs or Sf9-CD4 cells labeled with anti-CD4 mAb and sperm cells labeled with anti-monomorphic region of class II mAb was completely blocked. Considering these findings together with the fact that an interspecies' heterogeneity is present in CD4 amino acid sequence at the interactive site with class II, we elucidated that one of species' specific intercellular adhesions between two gametes at the fusion step in fertilization is definitely mediated by class II located on the posterior region of sperm head and CD4/p56(lck) complex on the plasma membrane of egg.

Amino Acid Sequence↗
PubMed2000

Efficient expression of the envelope protein of feline immunodeficiency virus in a recombinant feline herpesvirus type 1 (FHV-1) using the gC promoter of FHV-1.

We constructed two recombinant feline herpesvirus type 1 (FHV-1) expressing the envelope (Env) protein of feline immunodeficiency virus (FIV). One recombinant, designated dlTK-env, has the whole FIV env gene inserted at a thymidine kinase (TK) deletion site. The second recombinant, designated dlTK(gCp)-env, has a cassette containing a partial FIV env gene fused with the signal sequence of the gC protein of FHV-1 (under the control of the gC promoter) inserted at the same site. Growth kinetics of both the recombinants in Crandell feline kidney (CRFK) cells were similar to that of the parent strain of FHV-1. By indirect immunofluorescence assays and immunoblot analyses, we confirmed the expression of the FIV Env protein in CRFK cells infected with both recombinants. Enzyme-linked immunosorbent assays showed that the maximum Env expression level achieved by dlTK(gCp)-env was more than four times higher than that observed for dlTK-env. Flow cytometric analyses revealed that the Env protein produced by both recombinants was efficiently expressed on the cell surface. The dlTK(gCp)-env reported here may thus be a promising candidate for a live recombinant vaccine to protect against FIV infection.

Animals↗
PubMed2000

Antihyperalgesic effects of intrathecally administered magnesium sulfate in rats.

Intrathecal administration of MgSO(4) is reported to cause paralysis. However, the characteristic sensory disturbances have not been thoroughly investigated. We examined the effect of intrathecally administered MgSO(4) on the nociceptive threshold, using three different nociceptive measures, formalin test, hot plate test and paw pressure test in rats. The dose of MgSO(4) was 30, 100 or 300 microg. In acute nociceptive tests, intrathecal MgSO(4) did not cause any significant changes in the pain threshold. However, phase 2 of the formalin test was suppressed dose-dependently. It is known that spinal NMDA receptors are involved in the changes seen during the second (tonic) phase of the formalin test and in vitro studies showed that Mg(2+) can cause voltage-dependent blockade of NMDA receptor channel in the neurons of spinal dorsal horn. Thus, the suppressive effect of intrathecally administered MgSO(4) on the tonic inflammation-evoked behavior is mediated by the spinal NMDA receptors. Our results suggest that intrathecal administration of MgSO(4) may be therapeutically beneficial for patients with tonic pain involving the spinal NMDA receptors.

Animals↗
PubMed2000

The effect of interstimulus intervals and between-block rests on the auditory evoked potential and magnetic field: is the auditory P50 in humans an overlapping potential?

OBJECTIVE: The human auditory P50 may consist of overlapping potentials. To test this hypothesis, we manipulated interstimulus intervals (ISIs) and between-block rests, and recorded the P50, P50m, N100 and the N100m simultaneously. METHODS: Subjects were 12 right-handed healthy adults. Four conditions included: (1) 1.5 s/rest, (2) 1.5 s/successive, (3) 0.5 s/rest, and (4) 0.5 s/successive. Auditory stimuli were presented a total of 880 times for each condition. Auditory evoked potentials and magnetic fields were recorded. We examined the P50, N100, P50m, N100m and dipoles of the P50m and the N100m. RESULTS: There was no significant effect of the ISI on the P50 amplitudes, but the P50m amplitudes in the 0.5 s ISI conditions were significantly smaller than those in the 1.5 s ISI conditions. The N100 and the N100m amplitudes in the 0.5 s ISI conditions were significantly smaller than those in the 1.5 s ISI conditions. The N100 and the N100m amplitudes in the resting conditions were significantly larger than those in the successive conditions. The P50m dipoles were slightly deeper and more anterior than those of the N100m in primary auditory cortex. CONCLUSIONS: Central structures other than supratemporal cortex contribute to the P50 and that the P50 in humans represents overlapping potentials.

Acoustic Stimulation↗
PubMed2000

Pulmonary tuberculosis and serum IgE.

Several recent studies indicate that mycobacterium or viral infection may reduce IgE levels or suppress atopy or both. The present study was undertaken to investigate whether Mycobacterium tuberculosis infection and its successful treatment down-regulate serum total IgE levels, a marker of a Th2 response, due to enhancement of a Th1 response in adult patients with tuberculosis (TB). We prospectively studied the changes in serum total IgE and DTH response to tuberculin, a marker of a Th1 response in 10 healthy controls, 20 patients with pulmonary TB, and 19 asthma patients without TB. Measurement of serum total IgE and tuberculin skin tests were performed before initiation of treatment and after successful completion of 6 months treatment in TB patients, and at the corresponding intervals in controls and asthmatics. The initial serum total IgE concentrations were significantly higher in TB patients than in healthy controls (282 +/- 26 U/ml (mean +/- s.e.m.) in TB patients versus 126 +/- 56 U/ml in controls; P = 0.03). However, serum total IgE concentrations significantly decreased (282 +/- 26 U/ml before versus 151 +/- 12 U/ml after treatment; P = 0.03) and tuberculin indurations significantly increased (23.6 +/- 1.8 mm before versus 29.6 +/- 2.1 mm after treatment; P = 0.04) in TB patients. In contrast, initial serum IgE concentrations and tuberculin indurations did not differ significantly from post-observation data in both healthy controls and asthmatics (P>0.30). The present study confirmed that immune responses to M. tuberculosis down-regulate a Th2 immune response, and might contribute to the decreased prevalence of allergic disorders.

Asthma↗
PubMed2000

Auditory P50 obtained with a repetitive stimulus paradigm shows suppression to high-intensity tones.

We manipulated stimulus intensity and number of frequency bands in auditory stimuli in order to investigate the nature of P50 in human auditory evoked potentials. Pure-tone and mixed-tone conditions were examined. For each condition, four stimulus intensities were used: 55, 70, 85 and 100 dB sound pressure level (SPL). The P50s were obtained at Cz using a repetitive stimulus paradigm. P50 amplitudes increased as stimulus intensities increased up to 85 dB; with 100 dB stimulation amplitudes decreased. The number of frequency bands in the stimulus did not affect P50 amplitude. Considered in terms of P50 suppression under a conditioning/testing paradigm, the results suggest that the P50 wave reflects activity of the sensory gating mechanism in humans.

Adult↗
PubMed2000

Galectin-3 expression in various thyroid neoplasms and its possible role in metastasis formation.

Galectin-3 is a member of the beta-galactoside-binding protein family that plays an important role in cell-cell adhesion and in cell-matrix interaction. We have examined the expression of galectin-3 in normal, adenomatous, and malignant thyroid tissues and also in metastatic lesions. Galectin-3 was rarely expressed in normal thyroid tissue but was abundant in the cytoplasm of the neoplastic lesions. Among neoplastic lesions, galectin-3 was expressed to a greater extent in follicular carcinomas than in follicular adenomas and was present in greater amounts in papillary carcinomas than in follicular adenomas or carcinomas. Primary lesions of papillary carcinoma with metastasis contained significantly higher concentrations of galectin-3 than tumors of this type without metastases. However, the expression of galectin-3 was significantly decreased in metastatic lesions in the lymph nodes compared with their primary lesions. From these results, we assumed that galectin-3 works in different ways at different stages of thyroid neoplasm proliferation. Among primary tumors, galectin-3 expression is significantly different in 3 histological types. However, the continuity of progression among these tumors is not yet proven. In later stages, decreased expression of galectin-3 may aid the release of cancer cells from the primary lesions for invasion and metastasis.

Adenocarcinoma, Follicular↗
PubMed2000

Bradykinin stimulates eotaxin production by a human lung fibroblast cell line.

BACKGROUND: Bradykinin, a potent inflammatory peptide, is increased in the airways of allergic patients. Accompanying the elevated bradykinin levels are increases in both eosinophils and fibroblasts. Eotaxin, a potent eosinophil-specific chemotactic factor, is released by fibroblasts and increased in the lower respiratory tract of allergic patients. OBJECTIVE: We sought to test the hypothesis that lung fibro-blasts release eotaxin in response to bradykinin. METHODS: The potential of bradykinin to induce the release of eotaxin from the human lung fibroblast cell line HFL-1 was tested by cell culture and evaluation of the culture supernatant fluids and RNA for immunoreactive eotaxin and eotaxin messenger RNA. RESULTS: HFL-1 cells released eotaxin constitutively without stimulation, but bradykinin stimulated eotaxin release in a dose- and time-dependent manner and resulted in augmented expression of eotaxin messenger RNA. The release of eotaxin was sensitive to the action of glucocorticoids. Eosinophil chemotactic activity by HFL-1 supernatant fluids was inhibited by anti-human eotaxin-neutralizing antibody. Consistent with these results, inhibitors of bradykinin B2 receptors, but not bradykinin B1 receptors, inhibited bradykinin-induced eotaxin release. CONCLUSION: These data demonstrate that bradykinin may stimulate lung fibroblasts to release eotaxin and suggest the potential for this mechanism to be important in modulation of lung inflammation.

Bradykinin↗
PubMed2000

Inhibition of MIP-1alpha-induced human neutrophil and monocyte chemotactic activity by reactive oxygen and nitrogen metabolites.

Peroxynitrite, formed by the reaction between nitric oxide (NO) and superoxide, has been implicated in the pathogenesis of numerous disease processes. Several studies have shown that peroxynitrite-induced protein nitration may compromise enzyme and protein function. We hypothesized that peroxynitrite may regulate cytokine function during inflammation. To test this hypothesis, the neutrophil and monocyte chemotactic responses of macrophage inflammatory protein-1alpha (MIP-1alpha) incubated with and without peroxynitrite were evaluated. Peroxynitrite attenuated neutrophil chemotactic activity (NCA) and monocyte chemotactic activity (MCA) by MIP-1alpha in a dose-dependent manner (P < .05). The inhibitory effects were not significant on NCA and MCA induced by leukotriene B4 or complement-activated serum incubated with peroxynitrite. The reducing agents deferoxamine, dithiothreitol, and exogenous L-tyrosine abrogated the NCA and MCA inhibition by peroxynitrite. Papa-NONOate, an NO donor, or a combination of xanthine and xanthine oxidase to generate superoxide, did not show an inhibitory effect on NCA and MCA induced by MIP-1alpha. In contrast, 3-morpholinosydnonimine (SIN-1), a peroxynitrite generator, elicited a concentration-dependent reduction in NCA and MCA induced by MIP-1alpha. Consistent with its capacity to reduce NCA and MCA, peroxynitrite treatment reduced MIP-1alpha binding to neutrophils and monocytes. Nitrotyrosine was detected in the MIP-1alpha incubated with peroxynitrite. These findings are consistent with nitration of tyrosine by peroxynitrite with subsequent inhibition of MIP-1alpha binding to neutrophils and monocytes and a reduction in NCA and MCA. These data demonstrate that peroxynitrite modulates the inflammatory cell migration by MIP-1alpha, and they suggest that oxidants may play an important role in the regulation of MIP-1alpha-induced inflammatory cell chemotaxis.

Chemokine CCL3↗
PubMed2000

Improvement in development of porcine embryos reconstituted with cells from blastocyst-derived cell lines and enucleated oocytes by optimization of reconstruction methods.

The present study was conducted to establish the most suitable system for producing porcine reconstructed embryos by transferring cells from blastocyst-derived cell lines into enucleated oocytes. When the cells were fused to preactivated metaphase II oocytes, or the cells and arrested metaphase II oocytes were fused in medium without CaCl(2) and MgSO(4), the percentages (43-53%) of fused embryos were significantly lower than those (72-79%) produced by fusing the cells to arrested metaphase II oocytes in medium containing CaCl(2) and MgSO(4). High productive efficiency (7%) of blastocysts was obtained when reconstituted embryos produced by the last method were activated again at 3 hours after fusion (F/A --> Activation). Pronuclear formation was observed in 80-91% of the reconstructed embryos produced by F/A --> Activation, with no significant differences between different culture periods in the medium containing cytochalasin B. When cultured in the medium containing cytochalasin B for 0-1 h, almost all (83-85%) the embryos had one pronucleus and one polar body. However, the number of embryos with two pronuclei and no polar bodies was increased significantly by culturing in the medium containing cytochalasin B for 2-4 h. The cleavage rate (34-48%) of reconstructed embryos was not affected by the presence of cytochalasin B for 2 h after activation. However, the percentage of embryos that developed to the blastocyst stage was significantly higher in the presence (23%) than absence (5%) of cytochalasin B. The results indicate that F/A --> Activation and cytochalasin B treatment are effective for the production of porcine embryos reconstituted with cells from blastocyst-derived cell lines and enucleated oocytes.

Animals↗