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Biomedical subjects

H Ueda

Publications and source records attributed to H Ueda.

At least 181 records · Page 10Linked to original sources
PubMed2000

Dystrobrevin localization in photoreceptor axon terminals and at blood-ocular barrier sites.

PURPOSE: Dystrobrevin is a newly discovered dystrophin-associated protein with multiple sites for phosphorylation on tyrosine residues. In the present study, the cellular distribution and subcellular localization of dystrobrevin were examined in the adult rat retina, cornea, lens, iris, ciliary body, and cultured Müller cells. METHODS: Immunoblot analysis, confocal laser scanning microscopy, and immunoelectron microscopy were used to examine dystrobrevin expression. RESULTS: Immunoblot analysis showed that an approximately 87-kDa band was expressed predominantly in the lens, retina, iris and ciliary body, whereas an approximately 60-kDa band was expressed in cultured Müller cells, cornea, retina, iris, and ciliary body. Confocal microscopy demonstrated dystrobrevin in the inner limiting membrane, outer plexiform layer, and retinal pigment epithelium and around blood vessels in the retina. At the ultrastructural level, dystrobrevin was localized under cell membranes of rod spherules and cone pedicles of photoreceptor cell terminals but often was found in the cytoplasm of endothelial cells and Müller cells. Furthermore, dystrobrevin was colocalized with beta-dystroglycan in corneal endothelium; lens, iris, and ciliary epithelia; and cultured Müller cells. CONCLUSIONS: The present study demonstrates that dystrobrevin is expressed in neurons, glia, and endothelial cells in the rat retina. In addition, dystrobrevin is localized at the blood-ocular barrier sites in extraocular tissue. These data suggest that dystrobrevin plays an important role in visual function.

Animals↗
PubMed2000

Artificial trachea and long term follow-up in carinal reconstruction in dogs.

We have already reported successful carinal reconstruction of the trachea with an observation period of 1 - 2 years. In this study, we evaluate the long-term safety and efficacy of the reconstruction after 5-years of follow-up. The Y-shaped Marlex mesh tube was reinforced with a polypropylene spiral and coated with atelocollagen made from porcine skin. The prosthesis was 60 mm long with an outer diameter of 18 mm. Replacement of the tracheobronchial bifurcation was preformed through a right thoracotomy in a beagle dog. Bronchoscopical examination and sampling of the tracheal epithelium was performed periodically to check the function of cilia. The implanted prothesis was promptly infiltrated by the surrounding connective tissue and completely incorporated by the host trachea and bronchus. Bronchoscopically, sufficient epithelization was confirmed from the upper to the lower site of anastomosis. After 5 years neither stenosis nor dehiscence was observed. In spite of there being mesh-exposure at the luminal surface, the dog had no clinical symptoms until sacrifice for pathological examination. The bent frequency of the cilia was maintained within the normal range, indicating functional recovery of the regenerating airway. Our tracheal prosthesis is promising for clinical repair of the tracheobronchial bifurcation.

Animals↗
PubMed2000

[A case study of BRON (cough suppressant) tablet dependence--its social psychiatric and biological aspects].

A case of BRON tablet dependence is demonstrated. BRON is an over-the-counter (OTC) cough suppressant, which contains methylephedrine, dihydrocodeine, chlorpheniramine and caffeine. He took BRON tablet for the first time at the age of 16. In progress, he developed psychomotor excitement twice and finally manifested amotivational syndrome 3 years later from his first use. Longitudinal 123I-IMP SPECT (autoradiography method) findings demonstrated diffuse cerebral blood flow (CBF) decrease and relative hyperactivity in the lower frontal lobe. Diffuse decreased regional CBF, which was unchanged through its course for about 4 months, may show irreversible brain damage due to chronic BRON abuse. The findings of relative hyperactivity in the lower frontal lobe (orbitofrontal lobe) may reflect "craving for BRON" based on abnormal dopaminergic neural system activity. Based on the evidence that orbitofrontal hyperactivity is also seen in cases of cocaine abuse, methylephedrine, which is a cocaine-like central nervous system stimulant, may play the main role in BRON dependence formation. In Japan, BRON syrup abuse and dependence were in fashion for youth in 1980s. After the legal regulation of the market in 1988, it has gone out of fashion. While it is still easy to acquire OTC cough suppressant, reports of BRON tablet abuse and dependence are quite rare through 1980s and 1990s. This case suggests that BRON tablet abuse also could lead to dependence and come into new vogue for youth in the future. We should pay attention to the trend of OTC cough suppressant abuse and may need to regulate the market by law more severely.

Adolescent↗
PubMed2000

Regeneration of the junctional epithelium and connective tissue after transplantation of detergent-processed allo-teeth.

The authors have developed a new artificial dental implant and evaluated it in a dog model in terms of its potential to produce: I) regeneration of junctional epithelium; II) regeneration and attachment of connective tissue. The implants were constructed from allo-teeth. We removed the cell components from the periodontal ligaments of these teeth with a detergent (1% TritonX-100); the remaining acellular periodontal ligament acted as an extracellular matrix upon which regeneration and attachment could proceed. We placed 10 of these implants in the just-extracted sites of three beagle dogs. We observed regeneration of both junctional epithelium and connective tissue at all implant sites after 3 months. The connective tissue was attached in all cases. Use of the acellular periodontal ligament as an extracellular matrix may facilitate regeneration of host periodontal ligament tissue, thus contributing to recovery of host immunological defense and long-term oral function.

Animals↗
PubMed1999

Large vestibular aqueduct syndrome treated by hyperbaric oxygen.

We report the case of a 14-year-old girl with a large vestibular aqueduct (LVA) in whom hyperbaric oxygen (HBO) therapy was effective for the treatment of sensorineural hearing loss. The patient was referred to Nagoya University Hospital for the treatment of hearing loss on 14 September, 1998, because her right hearing level had declined abruptly on 22 August, 1998, and had not changed for 3 weeks since then in spite of steroid and prostaglandin therapy. Her audiogram revealed bilateral profound deafness of more than 110 dB. She had had profound hearing loss on the left side since she was 9 years old. HBO therapy was performed on 22 occasions from 17 September until 19 October, 1998. During the HBO therapy, her right hearing ability returned almost to the level determined prior to the abrupt loss, 60 dB. We therefore recommend HBO therapy for the treatment of sensorineural hearing loss associated with large vestibular aqueduct syndrome if the hearing ability does not recover following conventional treatment.

Adolescent↗
PubMed1999

Rat optic nerve oligodendrocytes develop in the absence of viable retinal ganglion cell axons.

Retinal ganglion cell axons and axonal electrical activity have been considered essential for migration, proliferation, and survival of oligodendrocyte lineage cells in the optic nerve. To define axonal requirements during oligodendrogenesis, the developmental appearance of oligodendrocyte progenitors and oligodendrocytes were compared between normal and transected optic nerves. In the absence of viable axons, oligodendrocyte precursors migrated along the length of the nerve and subsequently multiplied and differentiated into myelin basic protein-positive oligodendrocytes at similar densities and with similar temporal and spatial patterns as in control nerves. Since transected optic nerves failed to grow radially, the number of oligodendrocyte lineage cells was reduced compared with control nerves. However, the mitotic indices of progenitors and the percentage of oligodendrocytes undergoing programmed cell death were similar in control and transected optic nerves. Oligodendrocytes lacked their normal longitudinal orientation, developed fewer, shorter processes, and failed to form myelin in the transected nerves. These data indicate that normal densities of oligodendrocytes can develop in the absence of viable retinal ganglion axons, and support the possibility that axons assure their own myelination by regulating the number of myelin internodes formed by individual oligodendrocytes.

Animals↗
PubMed1999

A synthetic peptide derived from human immunodeficiency virus type 1 gp120 downregulates the expression and function of chemokine receptors CCR5 and CXCR4 in monocytes by activating the 7-transmembrane G-protein-coupled receptor FPRL1/LXA4R.

Because envelope gp120 of various strains of human immunodeficiency virus type 1 (HIV-1) downregulates the expression and function of a variety of chemoattractant receptors through a process of heterologous desensitization, we investigated whether epitopes derived from gp120 could mimic the effect. A synthetic peptide domain, designated F peptide, corresponding to amino acid residues 414-434 in the V4-C4 region of gp120 of the HIV-1 Bru strain, potently reduced monocyte binding and chemotaxis response to macrophage inflammatory protein 1beta (MIP-1beta) and stromal cell-derived factor 1alpha (SDF-1alpha), chemokines that use the receptors CCR5 and CXCR4, respectively. Further study showed that F peptide by itself is an inducer of chemotaxis and calcium mobilization in human monocytes and neutrophils. In cross-desensitization experiments, among the numerous chemoattractants tested, only the bacterial chemotactic peptide fMLF, when used at high concentrations, partially attenuated calcium mobilization induced by F peptide in phagocytes, suggesting that this peptide domain might share a 7-transmembrane, G-protein-coupled receptor with fMLF. By using cells transfected with cDNAs encoding receptors that interact with fMLF, we found that F peptide uses an fMLF receptor variant, FPRL1, as a functional receptor. The activation of monocytes by F peptide resulted in downregulation of the cell surface expression of CCR5 and CXCR4 in a protein kinase C-dependent manner. These results demonstrate that activation of FPRL1 on human moncytes by a peptide domain derived from HIV-1 gp120 could lead to desensitization of cell response to other chemoattractants. This may explain, at least in part, the initial activation of innate immune responses in HIV-1-infected patients followed by immune suppression.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Lysophosphatidic acid-induced, pertussis toxin-sensitive nociception through a substance P release from peripheral nerve endings in mice.

The intraplantar injection of lysophosphatidic acid (LPA) at doses of 0.1-100 pmol into the hind limb of mice showed dose-dependent nociceptive flexor responses. Repeated challenges of LPA at 100 pmol every 5 min showed constant responses at least for 30 min. The prior application of pertussis toxin (PTX) at a dose of 10 ng markedly reduced the following LPA (100 pmol) actions. In addition, the intraplantar application of CP-99994 (1 pmol), a substance P (NK1) receptor antagonist, but not CP-100263 (1 pmol), an inactive derivative, also markedly reduced the LPA responses. These findings suggest that LPA has a nociception-producing activity on sensory neurons through G(i/o) activation and substance P release from nociceptor endings.

Animals↗
PubMed1999

Selective association of G protein beta(4) with gamma(5) and gamma(12) subunits in bovine tissues.

The beta and gamma subunits of G proteins are tightly bound under physiological conditions, and so far, seven beta and 11 gamma subunit isoforms have been found. The relative abilities of the beta and gamma subunits to associate with each other have been studied using transfected cell assays, in vitro translation and the yeast two-hybrid system, but have not been fully characterized in various tissues. In the present study, we demonstrated the selectivity of association of the beta with gamma isoforms in bovine tissues. Immunoprecipitation of betagamma complexes from tissue extracts with antibodies against various gamma subunits and subsequent analyses revealed that beta(4) associated with the gamma subunits with the following rank order of selectivity: gamma(5) > gamma(12) > gamma(2) > gamma(3), while beta(2) bound to gamma(2), gamma(3), and gamma(12) more selectively than to gamma(5). By contrast, beta(1) associated with all gamma subunits without significant selectivity. Analyses of purified betagamma complexes containing various gamma isoforms revealed beta subunit compositions similar to those found in the immunoprecipitates. Particular combinations of beta and gamma subunit isoforms may contribute to maintaining efficient and specific signal transduction mediated by G proteins.

Amino Acid Sequence↗
PubMed1999

Selective coupling of mouse brain metabotropic sigma receptor with recombinant Gi1.

Various sigma (sigma) ligands including (+)-pentazocine stimulated [35S]GTPgammaS binding in synaptic membranes from the mouse cerebellum. The (+)-pentazocine-stimulated [35S]GTPgammaS binding was blocked by the treatment of membranes with pertussis toxin (PTX), but completely recovered by the reconstitution of PTX-treated membranes with recombinant Gi1, but not with GoA. These findings suggest that metabotropic sigma receptors are selectively coupled to Gi1 protein.

Animals↗
PubMed1999

Low dose of kyotorphin (tyrosine-arginine) induces nociceptive responses through a substance P release from nociceptor endings.

The intraplantar injection of kyotorphin (Kyo) elicited nociceptive flexor responses in mice in a dose-dependent manner between 0.1 and 100 fmol. These actions were completely blocked by substance P (NK1) receptor antagonists, such as CP-96345 and CP-99994, but not by their inactive derivatives, CP-96344 or CP-100263, nor by MEN-10376, an NK2 antagonist. Kyo-responses were also abolished by the local pretreatment with capsaicin to deplete substance P from nociceptor endings, and in tachykinin 1 gene K/O mice. These findings suggest that Kyo indirectly stimulates nociceptor endings through a local substance P release.

Animals↗
PubMed1999

Activation of Gi1 by lysophosphatidic acid receptor without ligand in the baculovirus expression system.

Lysophosphatidic acid (LPA) receptor has been attracting many neuroscientists' concerns, since it was reported to have a potential role in the neurogenesis, which occurs in the ventricular zone of the developing and adult brain. In the present experiments using baculovirus expression system, the LPA receptor encoded by ventricular zone gene 1 (Edg-2/Vzg-1) was found to be functionally coupled to Gi1, Goa, and G11, but not to GS. The coexpression of LPA receptor markedly decreased the expression of G protein alphai1 or alphaoa subunit, while the basal [35S]GTPgammaS binding significantly increased in the Gi1-preparation. The Scatchard Plot analysis indicates that the expression of LPA-receptor (Edg-2/Vzg-1) showed stimulation of Gi1 without agonist. These results suggest the Edg-2/Vzg-1 has an intrinsic acctivity on Gi1.

Animals↗
PubMed1999

Differential involvement of mu-opioid receptor subtypes in endomorphin-1- and -2-induced antinociception.

We investigated the role of mu-opioid receptor subtypes in both endomorphin-1 and endomorphin-2 induced antinociception in mice using supraspinally mediated behavior. With tail pressure as a mechanical noxious stimulus, both intracerebroventricularly (i.c.v.) and intrathecally (i.t.) injected-endomorphins produced potent and significant antinociceptive activity. Antinociception induced by i.t. and i.c.v. injection of endomorphin-1 was not reversed by pretreatment with a selective mu1-opioid receptor antagonist, naloxonazine (35 mg/kg, s.c.). By contrast, antinociception induced by i.t. and i.c.v. endomorphin-2 was significantly decreased by mu1-opioid receptor antagonist. Antinociception of both i.t. and i.c.v. endomorphin-1 and -2 was completely reversed by pretreatment with beta-funaltrexamine (40 mg/kg, s.c.). The results indicate that endomorphins may produce antinociception through the distinct mu1 and mu2 subtypes of mu-opioid receptor.

Analgesics, Opioid↗
PubMed1999

Peripheral morphine analgesia resistant to tolerance in chronic morphine-treated mice.

Intraplantarly (i.pl.)-injected morphine showed a peripheral analgesia in experiments to assess the blockade of bradykinin (i.pl.)-induced nociceptive flexor response in mice. The peripheral morphine analgesia in mice which developed central analgesic tolerance to chronic morphine (10 mg/kg s.c., 5 days), was equivalent to that in vehicle-treated mice in any doses between 0.1 and 1 nmol (i.pl.). These findings suggest that morphine tolerance in the central analgesia may use unique mechanisms deficient in the peripheral nervous system.

Analgesics, Opioid↗
PubMed1999

Phosphorylation of F-actin-associating G protein gamma12 subunit enhances fibroblast motility.

Eleven isoforms of G protein gamma subunit have been found thus far, but the precise roles of individual gamma subunits are not known. The gamma12 subunit has two unique properties: phosphorylation by protein kinase C and association with F-actin. To elucidate the role of gamma12, we overexpressed gamma12 and other gamma subunits in NIH 3T3 cells together with the beta1 subunit. The overexpressed gamma12 as well as endogenous gamma12, but not gamma2, gamma5, and gamma7 subunits, associated with cytoskeletal components. Expression of gamma12 induced remarkable changes including cell rounding, disruption of stress fibers, and enhancement of cell migration, but expression of other gamma subunits did not induce significant changes. Deletion of the N-terminal region of gamma12 decreased the abilities of gamma12 to associate with cytoskeletal fractions, to induce cell rounding, and to increase cell motility. Replacement by alanine of Ser2 of gamma12 (Ser1 of a mature gamma12 protein), a phosphorylation site for protein kinase C, eliminated these effects of gamma12, whereas a mutant in which Ser2 was replaced with glutamic acid showed effects equivalent to wild-type gamma12. These results indicate that phosphorylation of gamma12 at Ser2 enhances the motility of cells.

3T3 Cells↗
PubMed1999

Open sandwich ELISA with V(H)-/V(L)-alkaline phosphatase fusion proteins.

The Sandwich ELISA is a widely used technique to measure antigen concentration. Recently, a novel ELISA based on the interchain interaction of separated V(H) and V(L) chains from a single antibody variable region (Fv) was proposed (Open Sandwich ELISA). Since it employs a single antibody recognizing one epitope, the assay requires, in essence, only one cycle of incubation and washing steps. To demonstrate this directly, we have constructed a recombinant gene fusion encoding the V(H) chain of an anti-hen egg lysozyme (HEL) antibody HyHEL-10 and Escherichia coli alkaline phosphatase (V(H)-PhoA). The same type of gene fusion using V(L) chain instead of V(H) chain (V(L)-PhoA) was also constructed and the proteins were obtained with an E. coli expression/secretion system. Open Sandwich ELISAs were performed using microtiter plates with immobilized V(L) or V(H) fragment, and V(H)-PhoA or V(L)-PhoA, respectively, as the detection reagent which was simultaneously added to each well with samples. As a result, HEL concentrations in the samples were determined after one round of incubation and washing steps, with a signal generated in a direct relationship to the concentration of HEL added to the reaction mixture. The minimum detectable HEL concentration was approximately 10 ng/ml, which was almost equal to the value previously obtained with plate-immobilized V(L) and V(H) fragment displayed on M13 phage. When the active-site mutant V(H)-PhoA(D101S) was employed instead of V(H)-PhoA and reacted at an optimum pH of 10, a significant enhancement in signal was attained.

Alkaline Phosphatase↗
PubMed1999

Interaction of a lectin from Psathyrella velutina mushroom with N-acetylneuraminic acid.

A lectin from the fruiting body of Psathyrella velutina has been used as a specific probe for non-reducing terminal N-acetylglucosamine residues. We reveal in this report that P. velutina lectin recognizes a non-reducing terminal N-acetylneuraminic acid residue in glycoproteins and oligosaccharides. Binding of biotinyl P. velutina lectin to N-acetylneuraminic acid residues was prevented by desialylation of glycoconjugates and was distinguished from the binding to N-acetylglucosamine. Sialooligosaccharides were retarded or bound and eluted with N-acetylglucosamine on a P. velutina lectin column, being differentiated from each other and also from the oligosaccharides with non-reducing terminal N-acetylglucosamine which bound more strongly to the column.

Basidiomycota↗