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H Ueno

Publications and source records attributed to H Ueno.

At least 235 records · Page 13Linked to original sources
PubMed1997

Local expression of C-type natriuretic peptide markedly suppresses neointimal formation in rat injured arteries through an autocrine/paracrine loop.

BACKGROUND: In vivo gene transfer into injured arteries may provide a new means to facilitate molecular understanding of and to treat the intractable fibroproliferative arterial diseases. Selection of an optimal molecule to be transferred will be a key to successful gene therapy in the future. We tested the hypothesis that a secreted multifactorial molecule should act more efficiently through an autocrine/paracrine loop to suppress neointimal formation elicited in injured arteries than a simple growth-inhibiting molecule that might be expressed inside cells. METHODS AND RESULTS: We constructed an adenoviral vector (AdCACNP) expressing C-type natriuretic peptide (CNP), a secreted stimulator of membrane-bound guanyl cyclase. AdCACNP directs cells to secrete large quantities of biologically active CNP. Serum-stimulated DNA synthesis and cell proliferation were only moderately suppressed in arterial smooth muscle cells infected with AdCACNP in vitro. However, when AdCACNP was applied to balloon-injured rat carotid arteries in vivo, neointimal formation was markedly reduced (90% reduction) in an infection-site-specific manner without an increase in plasma CNP level. CONCLUSIONS: Our results showed that CNP, a secreted multifactorial molecule, was indeed effective in suppressing fibroproliferative response in injured arteries and suggest that the potent antiproliferation effect may not be the most critical factor for the effective suppression of neointimal formation. An adenovirus-mediated expression of CNP could be an effective and site-specific form of molecular intervention in proliferative arterial diseases.

Adenoviridae↗
PubMed1997

The phosphatidylinositol 3' kinase pathway is required for the survival signal of leukocyte tyrosine kinase.

Leukocyte tyrosine kinase (LTK) is a receptor tyrosine kinase which belongs to the insulin receptor superfamily and is mainly expressed in pre-B lymphocytes and neuronal tissues. Recently, we demonstrated that LTK utilizes Shc and IRS-1 as two major substrates and while both equally activate the Ras pathway, only IRS-1 suppresses apoptosis of hematopoietic cells, suggesting the existence of another unidentified signaling pathway downstream of IRS-1, which is relevant to the anti-apoptotic activity. In the present study, we found that wortmannin, a specific inhibitor of phosphatidylinositol 3' (PI3)-kinase, abolished the survival effects of LTK. Although c-Cbl is found to be phosphorylated by LTK and therefore is a second candidate linking LTK with the PI3-kinase pathway along with IRS-1, we found that the p85 subunit of PI3 kinase directly binds to tyrosine 753 of LTK, which is located within a YXXM motif, a consensus binding amino acid sequence for the SH2 domain of p85, but fails to bind to IRS-1 or c-Cbl. Ba/F3 cells which stably express the EGF receptor-LTK chimeric receptor carrying a mutation at tyrosine 753 fell into apoptotic death even in the presence of EGF, indicating that the PI3 kinase pathway is required for the survival effects of LTK.

Androstadienes↗
PubMed1997

Angiotensin II stimulates mitogen-activated protein kinases and protein synthesis by a Ras-independent pathway in vascular smooth muscle cells.

Angiotensin II (ANG II), a potent hypertrophic factor of vascular smooth muscle cells (VSMC), induces activation of the ras protooncogene product (Ras) and mitogen-activated protein (MAP) kinases and subsequent stimulation of protein synthesis in VSMC. In the present study, we examined whether Ras activation is required for ANG II-induced MAP kinase activation and stimulation of protein synthesis in cultured rat VSMC. Pretreatment with tyrosine kinase inhibitors, genistein and herbimycin A, or a putative phosphatidylinositol 3-kinase inhibitor, wortmannin, completely blocked ANG II-induced Ras activation, whereas neither of them had an effect on ANG II-induced MAP kinase activation. Adenovirus-mediated expression of a dominant negative mutant of Ha-Ras completely inhibited ANG II-induced Ras activation but failed to inhibit MAP kinase activation and stimulation of protein synthesis by this vasoconstrictor. These results indicate that ANG II stimulates MAP kinases and protein synthesis by a Ras-independent pathway in VSMC.

Androstadienes↗
PubMed1997

Expression and tissue localization of membrane-types 1, 2, and 3 matrix metalloproteinases in human invasive breast carcinomas.

Activation of the zymogen of matrix metalloproteinase 2 (proMMP-2, progelatinase A) possibly is one of the key steps in invasion and metastasis of various human carcinomas. Three different membrane-type MMPs (MT-MMPs), MT1-, MT2-, and MT3-MMPs are thought to be activators of proMMP-2 in the tissues. MT4-MMP is structurally different from the other three enzymes, and its function as proMMP-2 activator is uncertain. In the present study of human invasive breast carcinomas, we examined a correlation between the expression of MT1-, MT2-, and MT3-MMPs, immunolocalization of MT1- and MT2-MMPs, and proMMP-2 activation. Northern blot analysis demonstrated the predominant expression of MT1-MMP mRNA in carcinoma tissues (20 of 20 cases), whereas MT2-MMP was detected in only 25% of the cases (5 of 20 cases), and no detectable expression of MT3-MMP was observed. The expression levels of MT1-MMP but not MT2-MMP correlated well with the presence of lymph node and distant metastases, clinical stages, and size of tumors. Immunohistochemically, MT1-MMP was localized predominantly in the carcinoma cells in all of the samples (32 of 32 cases). Immunostaining of MT2-MMP in the carcinoma cells was observed in only 38% of the cases (12 of 32 cases). Immunoblot analysis of tumor homogenates confirmed the presence of these MT-MMPs. Activation of proMMP-2 was significantly higher in the carcinoma samples with lymph node or distant metastasis compared to carcinoma without metastasis, normal control, or fibrocystic disease (P < 0.05). An increase in the activation ratio of proMMP-2 correlated directly with the expression of MT1-MMP but not MT2-MMP, as measured by either Northern blot analysis or immunostaining. These results suggest that MT1-MMP may play a key role in human breast carcinoma invasion and metastasis by being predominantly responsible for activation of proMMP-2.

Adult↗
PubMed1997

Purification and molecular cloning of SH2- and SH3-containing inositol polyphosphate-5-phosphatase, which is involved in the signaling pathway of granulocyte-macrophage colony-stimulating factor, erythropoietin, and Bcr-Abl.

Grb2/Ash and Shc are the adapter proteins that link tyrosine-kinase receptors to Ras and make tyrosine-kinase functionally associated with receptors and Ras in fibroblasts and hematopoietic cells. Grb2/Ash and Shc have the SH3, SH2, or phosphotyrosine binding domains. These domains bind to proteins containing proline-rich regions or tyrosine-phosphorylated proteins and contribute to the association of Grb2/Ash and Shc with other signaling molecules. However, there could remain unidentified signaling molecules that physically and functionally interact with these adapter proteins and have biologically important roles in the signaling pathways. By using the GST fusion protein including the full length of Grb2/Ash, we have found that c-Cbl and an unidentified 135-kD protein (pp135) are associated with Grb2/Ash. We have also found that they become tyrosine-phosphorylated by treatment of a human leukemia cell line, UT-7, with granulocyte-macrophage colony-stimulating factor (GM-CSF). We have purified the pp135 by using GST-Grb2/Ash affinity column and have isolated the full-length complementary DNA (cDNA) encoding the pp135 using a cDNA probe, which was obtained by the degenerate polymerase chain reaction based on a peptide sequence of the purified pp135. The cloned cDNA has 3,958 nucleotides that contain a single long open reading frame of 3,567 nucleotides, encoding a 1,189 amino acid protein with a predicted molecular weight of approximately 133 kD. The deduced amino acid sequence reveals that pp135 is a protein that has one SH2, one SH3, and one proline-rich domain. The pp135, which contains two motifs conserved among the inositol polyphosphate-5-phosphatase proteins, was shown to have the inositol polyphosphate-5-phosphatase activity. The pp135 was revealed to associate constitutively with Grb2/Ash and inducibly with Shc using UT-7 cells stimulated with GM-CSF. In the cell lines derived from human chronic myelogenous leukemia, pp135 was constitutively tyrosine-phosphorylated and associated with Shc and Bcr-Abl. These facts suggest that pp135 is a signaling molecule that has a unique enzymatic activity and should play an important role in the signaling pathway triggered by GM-CSF and in the transformation of hematopoietic cells caused by Bcr-Abl.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Antisense repression of proto-oncogene c-Cbl enhances activation of the JAK-STAT pathway but not the ras pathway in epidermal growth factor receptor signaling.

Many growth factors including epidermal growth factor (EGF) induce tyrosine phosphorylation of the c-Cbl proto-oncogene product, whose function, however, remains unclear. Recently, Sli-1, a Caenorhabditis elegans homologue of c-Cbl, was found to be a negative regulator of let-23-mediated vulval induction pathway, suggesting that c-Cbl may negatively regulate EGF receptor (EGFR)-mediated signaling. In this study, by an antisense RNA approach, we examined the effects of expression level of c-Cbl on EGFR signaling and showed that overexpression of c-Cbl reduces and antisense repression of c-Cbl enhances autophosphorylation of EGF receptors and activation of the JAK-STAT pathway. However, in contrast to the Sli-1 protein, the expressed amount of c-Cbl does not affect activation of the Ras pathway, suggesting that the EGFR-mediated signaling pathways are differently regulated by c-Cbl among nematodes and mammals.

3T3 Cells↗
PubMed1997

Interaction of Nck-associated protein 1 with activated GTP-binding protein Rac.

Bacterially expressed glutathione S-transferase fusion proteins containing Rac1 were used to identify binding proteins of this Rho family GTPase present in a bovine brain extract. Five proteins of 85, 110, 125, 140 and 170 kDa were detected, all of which were associated exclusively with guanosine 5'-[gamma-thio]triphosphate-bound Rac1, not with GDP-bound Rac1. The 85 and 110 kDa proteins were identified as the regulatory and catalytic subunits respectively of phosphatidylinositol 3-kinase. Several lines of evidence suggested that the 125 kDa protein is identical with Nck-associated protein 1 (Nap1). The mobilities of the 125 kDa protein and Nap1 on SDS/PAGE were indistinguishable, and the 125 kDa protein was depleted from brain extract by preincubation with the Src homology 3 domain of Nck to which Nap1 binds. Furthermore, antibodies to Nap1 reacted with the 125 kDa protein. Nap1 was co-immunoprecipitated with a constitutively active form of Rac expressed in Chinese hamster ovary cells. The observation that complex formation between activated Rac and PAK, but not that between Rac and Nap1, could be reproduced in vitro with recombinant proteins indicates that the interaction of Nap1 with Rac is indirect. The 140 kDa Rac-binding protein is a potential candidate for a link that connects Nap1 to Rac. The multimolecular complex comprising Rac, Nap1 and probably the 140 kDa protein might mediate some of the biological effects transmitted by the multipotent GTPase.

Animals↗
PubMed1997

Highly sensitive high-performance liquid chromatographic determination method for a new erythromycin derivative, EM523, and its major metabolites in human plasma and urine using post-column tris(2,2'-bipyridine) ruthenium(III) chemiluminescence detection.

A method for the simultaneous determination of de(N-methyl)-N-ethyl-8,9 -anhydroerythromycin A 6,9-hemiacetal (EM523, I) and its three metabolites in human plasma and urine has been developed using high-performance liquid chromatography (HPLC) with chemiluminescence (CL) detection. Plasma and urine samples spiked with erythromycin as an internal standard were extracted with a mixture of dichloromethane and diethyl ether under alkaline conditions. The organic layer was evaporated under a stream of nitrogen gas. The reconstituted sample was injected into an HPLC apparatus and separated on an ODS column using a gradient elution method. The eluate was reacted on-line with a mixture of tris(2,2'-bipyridine) ruthenium(II) and peroxodisulfate, and the generated CL intensity was detected. Optimization of the CL reaction conditions resulted in a sensitive and stable CL intensity for the determination of I and its metabolites. The recovery of each compound from human plasma and urine, and the sensitivity, linearity, accuracy and precision of the method were satisfactory. The lower limits of quantitation for each compound using 0.2 ml of plasma and 0.1 ml of urine were 1 and 10 ng/ml, respectively. This method has been used for the determination of 1 in samples from clinical trials.

2,2'-Dipyridyl↗
PubMed1997

The role of cellular immunity both in the induction and effector phases of experimental allergic blepharoconjunctivitis (EAC) in rats.

In allergic conjunctivitis, the early phase reaction has been studied extensively both in humans and animals. Although cellular infiltration is the main feature of the late phase reaction, the role of cellular immunity remains unclear. The purpose of this study was to elucidate the role of cellular immunity both in the induction and effector phases of experimental allergic blepharoconjunctivitis (EAC). To analyse the involvement of cellular immunity in the induction phase, 6-8-week-old male Lewis rats were immunized with ovalbumin (OVA) emulsified with complete Freund's adjuvant (CFA), incomplete Freund's adjuvant (IFA), TiterMaxR (TM), aluminum hydroxide [Al(OH)3], or without any adjuvant. Three weeks after immunization, the rats were challenged with OVA by eye drops, and 24 hr later they were euthanized and their eyes, including the lids, blood, and lymph nodes were harvested for analysis of disease and immune responses. The results indicated that adjuvants were necessary to induce disease as well as both cellular and humoral immunity. Al(OH)3, CFA and TM induced stronger disease and cellular immunity than IFA. The intensity of disease correlated with that of cellular immunity. To further investigate the involvement of cellular immunity in EAC, lymph node cells collected from immunized rats were adoptively transferred into naive syngeneic recipients that were challenged 4 days later with OVA. EAC developed in the recipients of lymph node cells that were also stimulated in culture with OVA. These recipient rats developed cellular infiltration in the lid and conjunctiva, in a dose-dependent manner. These results suggest that cellular immunity played a major role in the development of EAC, both in the induction and effector phases.

Adjuvants, Immunologic↗
PubMed1997

Blood volume and flow velocity through parenchymal microvessels in ischemic brain edema of rats.

Focal cerebral ischemia was produced in rats with left middle cerebral artery occlusion for 24 hours. Regional CBF was measured by the 14C-iodoantipyrine technique. The distribution of red blood cells (RBC) and plasma in cerebral microvessels was determined by radioluminography using 51Cr-RBC and 125I-bovine serum albumin, respectively. The mean transit times of RBC and plasma, blood volume, and hematocrit were calculated. The water content was measured by specific gravity. The blood flow was reduced to 2% of the control value in the central core, where the brain edema was the most severe. The blood volume decreased to 25% and the mean transit times of RBC and plasma increased about tenfold. In the outer periphery, where CBF was reduced to 39% but brain edema was not induced, the blood volume was decreased to 76% while the mean transit time of RBC was increased 2.1-fold, being greater than the increase in the plasma transit time. These findings indicate that focal ischemia has variable effects on the blood volume and flow velocities of RBC and plasma in the parenchymal microvessels depending on the depth of blood flow and edema. A decrease in blood flow is probably related to a reduction in the flow velocities of RBC and plasma in the surrounding ischemic tissue rather than to decreased number of perfused capillaries in the ischemic core.

Animals↗
PubMed1997

Clinical significance of extrabowel skipped cancer infiltration in rectal cancer.

During a pathologic examination, cancer nodules, and not lymph node metastases, are often seen in the fatty tissue outside the rectum. The significance of this type of cancer spread, which is called extrabowel skipped cancer infiltration (ex), was investigated. A total of 369 patients who underwent resection of rectal adenocarcinoma between 1980 and 1992 were reviewed. All surgical specimens were examined microscopically to determine if ex existed in the fatty tissue outside the rectum or in the detached fatty tissue around the dissected lymph nodes. The ex was divided into four patterns: scattering (sct), vessel invasion (ves), neural invasion (ni), and nodular (nd). Ex was found in 130 patients (35.2%). Of these, 19 were sct, 58 ves, 21 ni, and 111 nd. The overall recurrence rates after curative resection were 52.8% in the ex(+) group and 24.0% in the ex(-) group (P < 0.001). The local recurrence rates were 35.8% and 14.9%, respectively (P < 0.01). The ex(+) group exhibited a significantly worse survival than the ex(-) group (P < 0.001). The presence of ex indicates the aggressive biologic activity of rectal cancer. Ex may be a significant prognostic predictor in these patients. Therefore, such treatments as extended dissection, postoperative adjuvant therapy, and a meticulous follow-up are all considered to be necessary for patients with ex.

Adenocarcinoma↗
PubMed1997

Ameloblastoma of the mandible metastasizing to the orbit with malignant transformation. A histopathological and immunohistochemical study.

We report here a case of ameloblastoma of the mandible with multiple local recurrences and metastasis to the orbit. The patient was a 63-year-old Japanese woman with visual disturbance of her right eye. Diagnostic imaging revealed a mass occupying the right orbital apex with partial intracranial involvement. She had been surgically treated for mandibular ameloblastoma 27 years previously, and the tumour had recurred three times in the past 5 years. The orbital tumour and recurrent ameloblastomas were investigated histopathologically and immunohistochemically. The tumour changed in morphology as it recurred, from follicular ameloblastoma without atypia to apparent malignant tumours disclosing undifferentiated or squamoid features. On immunohistochemical analysis, staining for cytokeratin was positive in the squamoid cells but not in the undifferentiated cells. Both histopathologically and immunohistochemically, the orbital tumour was almost identical to the undifferentiated recurrent tumour. The orbital tumour was distinct from the primary site or sites of recurrence of ameloblastoma, and we concluded that the mandibular ameloblastoma underwent malignant transformation with multiple recurrences and finally metastasized to the orbit.

Ameloblastoma↗
PubMed1997

A technique of minilaparotomy-assisted vaginal hysterectomy.

In minilaparotomy-assisted vaginal hysterectomy, the operation begins vaginally by opening the peritoneal folds and ligating the uterine vessels and uterosacral ligaments. Minilaparotomy is then performed for myomectomy, cutting the fallopian tubes and the utero-ovarian ligaments and detaching any adhesions on the anterior peritoneal angle. In 26 women who underwent this procedure, the feasibility rate was 100% and no intraoperative complications or postoperative morbidity was observed (except in one case of ovarian bleeding), indicating that vaginal hysterectomy assisted by minilaparotomy is a feasible approach for hysterectomy in the setting of large myomas, myomas with adhesions caused by endometriosis or previous pelvic surgery, and adenomyosis.

Adult↗
PubMed1997

Reversibility of monocytic differentiation of HL-60 cells by 1alpha,25 dihydroxyvitamin D3.

Although 1alpha,25(OH)2D3 induces HL-60 cells to differentiate into monocytes, whether or not these monocytes revert to native promyelocytes is not clear. To investigate this question, HL-60 cells were treated with 1alpha,25(OH)2D3, and divided into CD14-positive and -negative cells with a cell sorter. These two populations were cultured with or without 1alpha,25(OH)2D3. Sorted CD14-positive HL-60 cells, treated with 1alpha,25(OH)2D3 for 7 days, reverted to CD14-negative cells and promyelocyte-like cells if 1alpha,25(OH)2D3 was removed from the medium. We conclude that the 1alpha,25(OH)2D3-induced differentiation of HL-60 cells into monocytes is reversible, and continuous administration of 1alpha,25(OH)2D3 is required for the differentiation of HL-60 cells.

Calcitriol↗
PubMed1997

IL-7 induces proliferation, variable cytokine-producing ability and IL-2 responsiveness in naive CD4+ T-cells from human cord blood.

We investigated the effects of IL-7 on the proliferation and acquisition of cytokine-producing ability of naive CD4+ T-cells from human cord blood. Naive CD4+CD45RA+ T-cells from human cord blood expressed CDw127 (IL-7R) at higher levels than adult CD4+ CD45RA+ T-cells and produced IL-2 and a small amount of IFN-gamma upon stimulation with PMA and ionomycin. IL-7 induced IL-2-independent proliferation and both Th1- and Th2-type cytokine-producing abilities in cord blood CD4+CD45RA+ T-cells without stimulation via TCR. These results suggest that this IL-7-induced antigen-independent activation mechanism could contribute to maintaining the clonal size of naive T-cells with the potential to differentiate into either Th1 or Th2 cells at the sites of IL-7-expression.

Adult↗
PubMed1997

An HTLV-I carrier with Graves' disease followed by uveitis: isolation of HTLV-I from thyroid tissue.

We report a long-term (14-year) follow-up of a human T-lymphotropic virus type I (HTLV-I)-infected male who was successively afflicted with Graves' disease followed by uveitis. HTLV-I proviral DNA was detected by polymerase chain reaction in the thyroid tissue and HTLV-I was isolated from thyroid tissue by coculture with peripheral blood lymphocytes from an HTLV-I-uninfected healthy female. This case study supports a close relationship between Graves' disease and uveitis in an HTLV-I carrier.

Adult↗