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Biomedical subjects

H Ueno

Publications and source records attributed to H Ueno.

At least 19 recordsLinked to original sources
PubMed1995

TPO/c-mpl ligand induces tyrosine phosphorylation of multiple cellular proteins including proto-oncogene products, Vav and c-Cbl, and Ras signaling molecules.

Thrombopoietin (TPO)/c-mpl ligand is a hematopoietic growth factor that stimulates proliferation and maturation of megakaryocytes. To analyze the signaling pathway downstream of the c-mpl product, we used a human megakaryoblastic cell line, Mo7e, that has been proved to be responsive to TPO in terms of DNA synthesis. In this study, we found that TPO treatment resulted in tyrosine phosphorylation of Jak-2 kinase. Moreover, it was revealed that several functional molecules involved in the Ras signaling pathway, Shc and Sos, were phosphorylated by treatment with TPO. Finally, tyrosine phosphorylation of the proto-oncogene products, Vav and c-Cbl, has been proved to be induced by TPO. These results suggest that TPO could activate several signaling pathways including the Jak/Stat pathway, the Ras pathway and possibly another pathway involving the c-Cbl proto-oncogene product.

Cell Cycle Proteins↗
PubMed1995

Properties of the voltage-gated calcium channels mediating dopamine and acetylcholine release from the isolated rat retina.

We examined the properties of voltage-gated calcium channels mediating endogenous dopamine (DA) and acetylcholine (ACh) release in the isolated rat retina. Application of 30 mM KCl elicited the release of DA and ACh, and these releases were abolished in Ca(2+)-free medium. The high K(+)-evoked DA release was largely blocked by both of omega-agatoxin IVA and omega-conotoxin MVIIC, P- and Q-type calcium channel antagonists, and partly blocked by isradipine, and L-type calcium channel antagonist, and omega-conotoxin GVIA, an N-type calcium channel antagonist. omega-Agatoxin IVA at a small dose, sufficient to block P-type channels alone, was however without effect. On the other hand, the high K(+)-evoked ACh release was partly blocked by omega-agatoxin IVA and omega-conotoxin MVIIC, but was resistant to isradipine and omega-conotoxin GVIA. Flunarizine, a non-selective T-type calcium channel antagonist, did not inhibit the release of DA and ACh. Cd2+ markedly blocked the release of both DA and ACh, Co2+ and Ni2+ slightly blocked the release of DA, and the release of ACh was not blocked by these two divalent cations. These results suggest that the high K(+)-evoked release of retinal DA is largely mediated by omega-agatoxin IVA and omega-conotoxin MVIIC sensitive calcium channels (probably Q-type channels), while the release of retinal ACh is largely mediated by as yet uncharacterized Cd2+ sensitive calcium channels. The properties of voltage-gated calcium channels involved in the release of ACh in the rat retina differ from those of DA.

Acetylcholine↗
PubMed1995

The relationship between HTLV-I-infected cell lines and uveitis.

BACKGROUND: Recently it has been revealed that human T-lymphotropic virus type I (HTLV-I) infection causes uveitis in human. We previously reported HTLV-I uveitis in a rabbit. To investigate the relationship between HTLV-I infection and uveitis, we established an HTLV-I-infected T-cell clone from the cells infiltrated in the anterior chamber of this rabbit and compared the viral production with that in other HTLV-I-infected cell lines. METHODS: The clonality was determined by Southern blot hybridization with various restriction enzymes. Flow-cytometric analysis was used for investigating the expression of cell surface antigens. To compare viral production, we performed reverse transcriptase assay of the culture media and inhibition enzyme-linked immunosorbent assay to determine the quantity of intracellular HTLV-I antigens. RESULTS: The established clone was Ia (MHC class II) positive T cell. This T-cell clone was able to produce about three times more HTLV-I antigens than other HTLV-I-infected cell lines tested. CONCLUSION: A T-cell clone established from anterior aqueous of an HTLV-I uveitis rabbit can produce more HTLV-1 antigen than other HTLV-I-infected cell lines tested and it can be recognized easily by the immune system. Therefore, this high virus production may have a causal relation to uveitis.

Animals↗
PubMed1995

Hypoxia-induced expression of vascular endothelial growth factor by retinal glial cells promotes in vitro angiogenesis.

To determine whether retinal glial cells (RGCs) participate in the paracrine regulation of retinal neovascularization, we investigated whether cultured RGCs synthesize and release vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) under normoxic or hypoxic conditions. Northern blot analysis demonstrated that cultured RGCs transcribed both VEGF mRNA with two molecular bands approximately 3.9 and 4.3 kilobases (kb), and bFGF mRNA with approximately 3.7 and 6.0 kb. The expression of VEGF mRNA was greatly enhanced by hypoxic cultivation (2% oxygen) when compared with normoxic cultivation (20% oxygen), while the expression of bFGF mRNA by RGCs was not significantly affected by hypoxia. The effects of RGCs-conditioned media (CM) on tritiated-thymidine incorporation and in vitro angiogenesis by retinal capillary endothelial cells (RECs) in producing the formation of capillary-like tubes in type I collagen gels, were evident in the observation that RGCs-CM harvested after hypoxic cultivation significantly enhanced tritiated-thymidine incorporation (1.9 times, P < 0.01) and in vitro angiogenesis (2.4 times, P < 0.01) compared with the normoxic RGCs-CM. These enhancing effects of RGCs-CM at hypoxia were suppressed by anti-VEGF neutralizing antibody. Furthermore, RECs were shown to express mRNA encoding the VEGF receptor flt-1 by northern blot analysis. These results suggest that VEGF expressed by RGCs under hypoxic conditions plays an integral role in the initiation and progression of retinal neovascularization in a paracrine manner.

Animals↗
PubMed1995

Further studies of the binding specificity of the leukocyte adhesion molecule, L-selectin, towards sulphated oligosaccharides--suggestion of a link between the selectin- and the integrin-mediated lymphocyte adhesion systems.

This communication is concerned with the binding specificity of the leukocyte-adhesion molecule L-selectin (leukocyte homing receptor) towards structurally defined sulphated oligosaccharides of the blood group Le(a) and Le(x) series, and of the glycosaminoglycan series heparin, chondroitin sulphate and keratan sulphate. The recombinant soluble form of the rat L-selectin (L-selectin-IgG Fc chimera) investigated here was shown previously to bind to lipid-linked oligosaccharides 3-O, 4-O and 6-O sulphated at galactose, such as sulphatides and a mixture of 3-sulphated Le(a)/Le(x) type tetrasaccharides isolated from ovarian cystadenoma, as well as to the HNK-1 glycolipid with 3-O sulphated glucuronic acid. In the present study, the L-selectin investigated in both chromatogram binding and plastic microwell binding experiments using neoglycolipids was found to bind to the individual 3-sulphated Le(a) and Le(x) sequences (penta-, tetra- and trisaccharides), and with somewhat lower intensities to their non-fucosylated analogues. Glycosaminoglycan disaccharides of keratan sulphate, heparin and chondroitin sulphate types were also bound by L-selectin in one or both assay systems, leading to the conclusion that clustered glycosaminoglycan oligosaccharides with 6-O sulphation of N-acetylgalactosamine, N-acetylglucosamine or glucosamine, 4-O sulphation of N-acetylgalactosamine, 2-O sulphation of uronic acid, N-sulphation of glucosamine and, to a lesser extent, the non-sulphated uronic acid-containing disaccharides, can support L-selectin adhesion. As inflammatory chemokines (short-range stimulators of lymphocyte migration which trigger integrin activation) are known to bind to endothelial glycosaminoglycans, we propose that the binding of the lymphocyte membrane L-selectin to endothelial glycosaminoglycans may provide a link between the selectin-mediated and integrin-mediated adhesion systems in leukocyte extravasation cascades. The possibility is also raised that lymphocyte L-selectin interactions with glycosaminoglycans may contribute to pathologies of glycosaminoglycan-rich tissues, e.g. cartilage loss in rheumatoid arthritis and inflammatory lesions of the cornea.

Animals↗
PubMed1995

Seroepidemiological survey of Bartonella (Rochalimaea) henselae in domestic cats in Japan.

A total of 199 domestic cat serum samples from 3 geographical areas (northeastern, central and southwestern) of Japan collected between 1992 and 1994 were examined for serum antibody against Bartonella henselae using an immunofluorescent assay. The antibody prevalence was 15.1% (30/199). A significant difference in the prevalence of B. henselae antibody was observed between the northeastern area (6.3%:3/48) and the central area (22.0:13/59) in Japan. There was no significant difference between the average age of seropositive cats (4.39 +/- 3.26 years) and that of seronegative cats (4.03 +/- 3.84 years), and also between the frequency of seropositive male cats (16.5%:15/91) and that of seropositive female cats (11.8:9/76). This is the first report of B. henselae antibodies in cats in Japan

Age Factors↗
PubMed1995

Quantitative analysis of repeat adenovirus-mediated gene transfer into injured canine femoral arteries.

We quantitatively evaluated the effectiveness of a repeat administration of a recombinant adenoviral vector expressing bacterial Escherichia coli lacZ into the same arterial site of a relatively large animal, the dog. The replication-defective adenoviral vector was introduced percutaneously into balloon-injured femoral arteries through a double-balloon catheter. After a single dose of adenoviral vector, up to 90% of surface (73 +/- 16%, n = 7) and smooth muscle cells in multiple layers of the media showed transgene expression as evaluated by 5-bromo-4-chloro-3-indoyl beta-D-galactopyranoside histostaining without extralocal expression, as assessed by polymerase chain reaction. High-level expression (measured as beta-galactosidase activity) peaked 7 days after transfer and was transient, although it was retained for a month. Second does of the same adenovirus to the same arterial site were given 1, 2, 5, or 8 weeks after the first administration. At 1 week the second dose significantly enhanced lacZ expression. At 2, 5, or 8 weeks the second dose reinduced lacZ expression at 25% to 30% of the full expression. lacZ expression was also detected in preimmuned dogs, although the expression levels correlated inversely to the titer of neutralizing antibodies in their serum. These results demonstrate that arterial gene expression can be enhanced by a second administration of the same adenovirus after a short interval and that a repeat dose after a long interval partially but significantly reinduces gene expression despite the presence of an immune response. These data may provide an additional scientific foundation for the use of adenovirus-mediated arterial gene transfer in future clinical practice.

Adenoviridae↗
PubMed1995

Arteriovenous malformation associated with a large cyst--case report.

A 37-year-old male presented with an arteriovenous malformation in the left temporal lobe associated with a large cyst. The cyst was drained and the nidus completely excised. The histological findings suggest that repeated subclinical hemorrhages from neovascular channels of the cyst membrane was responsible for the growth of the cyst.

Adult↗
PubMed1995

[Pulmonary endometriosis with recurrent catamenial hemoptysis].

A 32-year-old woman with a history of dilation and curettage for missed abortion at 31 years old had sudden hemoptysis during menstruation on May 25, 1993. She had catamenial hemoptysis again, and was admitted to our hospital on July 21, 1993. After admission, catamenial hemoptysis occurred, and a nodular shadow was noted in the right S4 area on chest roentgenogram and computed tomogram. A few days after menstruation, hemoptysis and the abnormal shadow on chest roentgenogram disappeared. Pulmonary endometriosis was diagnosed by clinical course, past history, and chest roentgenographic findings. During the next menstruation, hemoptysis and a nodular shadow in the right S4 area on chest roentgenogram recurred, so transbronchial lung biopsy and laparoscopy were done. TBLB specimens revealed macrophages with phagocytosed hemosiderin, and laparoscopy revealed pelvic endometriosis. She was treated with buserelin acetate. Catamenial hemoptysis and the nodular shadow on the chest roentgenogram disappeared after treatment.

Adult↗
PubMed1995

Percutaneous transluminal gene transfer into canine myocardium in vivo by replication-defective adenovirus.

OBJECTIVE: The aim was to examine the feasibility, efficiency and safety of adenovirus-mediated in vivo gene transfer into the canine myocardium by a percutaneous transluminal method using a needle-catheter. METHODS: Either a replication-defective adenovirus (Adex1SRLacZL) or a plasmid (pSRLacZ), both expressing E. coli lacZ coding beta-galactosidase (beta-gal), was directly injected into the left ventricle of dogs through a needle-catheter inserted via a femoral artery. Expression of lacZ was examined by histochemical staining and quantified by measuring beta-gal activity. RESULTS: Injections with Adex1SRLacZL induced lacZ expression as a result of 40 out of 41 injections; the expression level was 10 times higher than that obtained with pSRLacZ. Induced beta-gal activity was detected within 24 h, peaked at 7 days and retained for 2 weeks after gene transfer. A repetitive administration of the same adenovirus at 14 days after the first injection also evoked a reduced but significant level of expression despite neutralizing antibodies to adenovirus in serum. Although injection induced an inflammatory response that peaked at 3 days after injection and gradually subsided without a second peak, the temporal change and the extent of inflammation induced by adenovirus injection was not significantly different from those induced by injection with either saline or plasmid. Neither leakage of enzymes such as CPK or LDH nor alteration in the ECG was detected in the 30 days following gene transfer. CONCLUSIONS: Our findings demonstrate that a catheter-mediated direct injection with an adenovirus can induce gene expression in the ventricle more efficiently without additional myocardial damage and inflammation compared with injection with a plasmid. A repeat dose of the same adenovirus elicited gene expression at an attenuated but significant level. This method may potentially have clinical applications: in modifying myocardial phenotype and/or improving general circulation under certain circumstances.

Adenoviridae↗
PubMed1994

Derivation and application of monoclonal antibodies recognizing several epitopes on bovine serum albumin.

Three (AB-3, AB-4 and AB-6) monoclonal antibodies (mAb) to bovine serum albumin (BSA) were derived and characterized for their physicochemical and immunological properties. AB-3 recognized an epitope distinct from epitopes recognized by AB-4 and AB-6 as determined by binding inhibition assay. AB-4 and AB-6 mAbs recognized similar but not identical epitopes on BSA. Based on the antigenic specificity, we applied these mAbs to quantitative analysis of BSA in medium and to depletion of BSA from culture medium containing fetal calf serum (FCS). For quantitative analysis, we employed a sandwich enzyme-linked immunosorbent assay (ELISA) using biotinylated AB-3, solid-phase of AB-6 and an avidin-biotin-peroxidase complex system. This assay was highly sensitive and quantitative in the range of BSA concentration at 10 to 1,500 ng/ml. To deplete BSA from medium, we prepared affinity-gel coupled to AB-6. Repeated treatment of FCS-containing medium with the affinity-gel efficiently depleted BSA from the medium. The depletion capacity was 0.74 to 1.0 moles of BSA/mole of coupled mAb.

Animals↗
PubMed1994

"Undifferentiated" cerebral primitive neuroectodermal tumor in a young adult--case report.

A 21-year-old female presented with a cerebral primitive neuroectodermal tumor (PNET) without either glial or neuronal differentiation, who has survived for 27 months without neurological deficit following total removal of the tumor, radiotherapy, and intensive chemotherapy. Both immunohistochemical and ultrastructural studies are important for the diagnosis of PNET. "Undifferentiated" PNET may be a distinct entity from common PNET which shows either glial or neuronal differentiation or both.

Adult↗
PubMed1994

[HTLV-I and retinal antigen recognized by T cells].

MT-2 immune but not naive murine (B10.BR) spleen cells responded not only to HTLV-I-infected cell lines but also to retinal antigens of various species by antigen-induced cell proliferation. The phenotype of the responding cells against HTLV-I-infected cell lines as well as retinal antigens was Thy-1.2+, CD4+ and CD8-. The antigen-induced cell proliferation against both HTLV-I-infected cell lines and retinal antigens was clearly inhibited by monoclonal antibodies to CD3, CD4, and MHC class II (I-AK). These data indicate that an epitope of HTLV-I-infected cell lines recognized by the CD4+ T cell is crossreactive to that of retinal antigens.

Animals↗
PubMed1992

The fms-like tyrosine kinase, a receptor for vascular endothelial growth factor.

The fms-like tyrosine kinase (Flt) is a transmembrane receptor in the tyrosine kinase family. Expression of flt complementary DNA in COS cells conferred specific, high-affinity binding of vascular endothelial growth factor, also known as vascular permeability factor (VEGF-VPF), a factor that induces vascular permeability when injected in the guinea pig skin and stimulates endothelial cell proliferation. Expression of Flt in Xenopus laevis oocytes caused the oocytes to release calcium in response to VEGF-VPF. These findings show that flt encodes a receptor for VEGF-VPF.

Animals↗