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Biomedical subjects

Y Sano

Publications and source records attributed to Y Sano.

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

Conjunctival inflammation induces Langerhans cell migration into the cornea.

PURPOSE: The virtual absence of Langerhans cells (LC) in donor or recipient corneal epithelium is known to be an important factor in the acceptance of orthotopic corneal allografts. Though it is well known that various types of stimulation to the cornea induce LC migration into the corneal epithelium, resulting in poor graft survival, the influence of conjunctival inflammation on LC migration into the cornea has not been elucidated. Therefore we examined whether LCs migrate into the cornea in the presence of conjunctival inflammation. METHODS: Sixteen BALB/c mice were divided into four groups. Group A: 4 mice with corneal inflammation induced by two 9-0 silk interrupted sutures in the central cornea (positive control); Group B: 4 mice with conjunctival inflammation induced by two 9-0 silk interrupted sutures in the temporal and nasal bulbar conjunctiva 1 mm from the limbus; Group C: 4 mice with conjunctival inflammation by two 10-0 nylon interrupted sutures in the temporal and nasal bulbar conjunctiva 1 mm from the limbus; and Group N: 4 mice with no inflammation (untreated, naive control). Fourteen days after suturing, the mice were sacrificed and LCs migrated into the corneal epithelium were counted by immunofluorescence assay using anti-Ia antibody. RESULTS: In Group A, Ia(+) cells in the cornea totaled 29.4 +/- 3.8 cells/mm(2); in Group B, 7.9 +/- 1.2 cells/mm(2); in Group C, 7.8 +/- 0.7 cells/mm(2); and in Group N, 1. 6 +/- 0.5 cells/mm(2). Significantly greater numbers of Ia(+) cells were detected in Groups A, B and C than in Group N (p < 0.005). CONCLUSIONS: Conjunctival inflammation caused by sutures in the bulbar conjunctiva induced LC migration into the cornea. These results indicate that conjunctival inflammation influences the corneal immunological environment, and may affect the fate of orthotopic corneal allografts.

Animals↗
PubMed1999

Quantitative determination of a potent lipopolysaccharide antagonist, E5564, in rat and dog plasma by high-performance liquid chromatography with fluorescence detection.

The assay method was established for the quantification of a potent lipopolysaccharide (LPS) antagonist, E5564, in rat and dog plasma using HPLC. E5564 and the I.S. (an analogue of E5564) were extracted and derivatized with 9-Anthryldiazomethane (ADAM reagent) to be given fluorescence. LC-MS analysis indicated that single molecule of E5564 was coupled with two molecules of ADAM reagent at one on each of the phosphorus groups. After solid-phase extraction, ADAM derivatives of E5564 and the I.S. were separated on an ODS column using methanol/ethanol containing sodium acetate as a mobile phase at 1.2 ml/min (gradient elution), and detected by a fluorescence detector (excitation: 254 nm, emission: 415 nm). The intra-day and inter-day precision were less than 14.4%, and accuracy were within +/-13.0% in the concentration range of 30 to 20,000 ng/ml plasma in both species. E5564 was stable for at least 13 days in rat and dog plasma at -20 degrees C, and the processed sample was stable for up to 14 days at 4 degrees C. This validated method was successfully applied to the evaluation of the pharmacokinetics of E5564 in rats and dogs after single bolus intravenous doses.

Animals↗
PubMed1999

Nuclear vitamin K2 binding protein in human osteoblasts: homologue to glyceraldehyde-3-phosphate dehydrogenase.

The importance of vitamin K in bone metabolism has been suggested previously. The binding protein of vitamin K2 (menatetrenone, 2-methyl-3-all-trans-tetraphenyl-1,4-naphthoquinone, menaquinone-4), found in nuclear extract of human osteoblasts, binds to vitamin K1 and K2, but not K3. Since the binding protein does not bind to other steroids or vitamins, such as hydrocortisone, vitamin A, 1,25(OH)2vitamin D3, trolox (a derivative of vitamin E), and warfarin, a specific binding protein to vitamin K1 and vitamin K2 in osteoblasts was suggested. The size of the specific binding protein was revealed to be 6S by sucrose density gradient and about 40,000 daltons by SDS-PAGE. Twenty amino acid residues from the N-terminal were the same as human glyceraldehyde-3-phosphate dehydrogenase (GAPDH), but the 21st residue, alanine, was replaced with serine. The binding protein was precipitated with anti-human GAPDH antibody, and authentic human GAPDH could bind vitamin K2. We propose that the nuclear binding protein for vitamin K2 exists in nuclei similarly to other vitamin receptors and that the molecular structure is very close to human GAPDH.

Amino Acid Sequence↗
PubMed1999

Detection of minor alloantigen-specific cytotoxic T cells after rejection of murine orthotopic corneal allografts: evidence that graft antigens are recognized exclusively via the "indirect pathway".

BACKGROUND: The immune mechanisms by which corneal allografts are rejected in normal ocular graft beds have not been identified. Both acceptors and rejectors of these types of grafts display donor-specific delayed hypersensitivity and in vitro proliferating primed T cells, yet neither develop conventional, donor-specific cytotoxic T cells. We wished to determine whether unconventional donor-specific cytotoxic T cells are generated in rejector mice that recognize donor minor alloantigens presented by recipient major histocompatibility complex (MHC) molecules. METHODS: BALB/c mice received orthotopic corneal allografts from C57BL/10 donors in normal eyes. At 4 weeks (when 50% of grafts can be designated as rejected), primed cytotoxic T lymphocyte (CTL) activity in draining lymph nodes and spleen was assayed on targets selected to present donor-type minor H antigens on recipient MHC molecules. Control mice received heterotopic corneal allografts and were similarly examined. RESULTS: Lymphoid organs of recipients that rejected orthotopic or heterotopic corneal allografts contained CTL that lysed targets expressing donor-type minor H antigens presented by recipient MHC molecules. By contrast, no CTL activity was detected from lymphoid cells of recipients that accepted orthotopic corneal allografts. Rejection of orthotopic corneal allografts placed into normal mouse eyes correlates directly with the generation of donor-specific CTL that recognize minor H antigens in the context of recipients MHC molecules. CONCLUSIONS: These results indicate the indirect pathway of alloantigen presentation is the only pathway operative in the process by which orthotopic corneal allografts are rejected. The roles of emigrant Langerhans cells and corneal lymphatics in the indirect pathway are discussed.

Animals↗
PubMed1999

Singlet oxygen ((1)Delta(g)O(2)) as the principal oxidant in myeloperoxidase-mediated bacterial killing in neutrophil phagosome.

Intraphagosomal viability of wild type E. coli and lycopene (a powerful (1)O(2) quencher)-producing transformant E. coli was investigated using human polymorphonuclear leukocytes as the cells for phagocytosis of opsonized viable bacteria. While the viability of both wild type and the transformant E. coli decreased very rapidly in the phagosome, but the viability of the lycopene-transformant in phagosomes was about 1.7 times higher than that of wild type E. coli after 5 min of incubation. The results were very similar to the results obtained when E. coli strains were exposed to (1)O(2) generated in myeloperoxidase-H(2)O(2)-Br(-) system (a pure (1)O(2) generating system) at pH 4.5. The reason for HOCl, which may be generated in the myeloperoxidase-H(2)O(2)-Cl(-) system under physiological conditions but does not become involved in bactericidal action, could be explained by the near neutral pH in phagosomes at which bacterial killing by chlorination is extensively attenuated. This is the first report which proved (1)O(2)-mediated bacterial killing in neutrophil-bacterial phagosomal system.

Carotenoids↗
PubMed1999

Structural Change in Dextran: Mechanism of Insolubilization by Adsorption on the Air-Liquid Interface.

To clarify the insolubilization mechanism of water-soluble dextran, the association of dextran in water was studied by dynamic light scattering measurements and a surface chemical approach. Dynamic light scattering measurements indicated that insolubilization of dextran is accompanied by a structural change in dextran. Surface tension data for dextran molecules revealed a structural change in dextran molecules at the air-liquid interface. These results suggest that insolubilization of dextran molecules occurred through an adsorption process at the air-liquid interface. Insolubilization of dextran molecules can be reduced by inhibition of this structural change in dextran molecules. The presence of boron as an impurity was found to trigger precipitation based on inductively coupled plasma mass spectrometry measurements and precipitation tests. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

ATF-2 is a common nuclear target of Smad and TAK1 pathways in transforming growth factor-beta signaling.

Upon transforming growth factor-beta (TGF-beta) binding to its cognate receptor, Smad3 and Smad4 form heterodimers and transduce the TGF-beta signal to the nucleus. In addition to the Smad pathway, another pathway involving a member of the mitogen-activated protein kinase kinase kinase family of kinases, TGF-beta-activated kinase-1 (TAK1), is required for TGF-beta signaling. However, it is unknown how these pathways function together to synergistically amplify TGF-beta signaling. Here we report that the transcription factor ATF-2 (also called CRE-BP1) is bound by a hetero-oligomer of Smad3 and Smad4 upon TGF-beta stimulation. ATF-2 is one member of the ATF/CREB family that binds to the cAMP response element, and its activity is enhanced after phosphorylation by stress-activated protein kinases such as c-Jun N-terminal kinase and p38. The binding between ATF-2 and Smad3/4 is mediated via the MH1 region of the Smad proteins and the basic leucine zipper region of ATF-2. TGF-beta signaling also induces the phosphorylation of ATF-2 via TAK1 and p38. Both of these actions are shown to be responsible for the synergistic stimulation of ATF-2 trans-activating capacity. These results indicate that ATF-2 plays a central role in TGF-beta signaling by acting as a common nuclear target of both Smad and TAK1 pathways.

Activating Transcription Factor 2↗
PubMed1999

Quantitative determination of E5880 in rat plasma by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.

A simple and sensitive method is described for the determination of E5880 in rat plasma. The method is based on high-performance liquid chromatography/electrospray ionization mass spectrometry, using deuterated E5880 as an internal standard. Selected reaction monitoring is employed for selectivity and sensitivity, this in turn enables quantification in a short period of time (within 7 minutes) over the extended range of 0.1-1000 ng/ml with acceptable precision and accuracy. The method demonstrated to be suitable for the quantitative analysis of E5880 in rat plasma. The pharmacokinetic profile of E5880 after a single intravenous administration of E5880 was elucidated.

Animals↗
PubMed1999

The wear of a polyethylene socket articulating with a zirconia ceramic femoral head in canine total hip arthroplasty.

Wear of yttria-zirconia (zirconia) in the femoral head was investigated in mature mongrel dogs weighing 10 to 13 kg. Two dogs, which were used as a control group, were sacrificed 18 months after implantation of the uncemented modular hip system with an alumina ceramic (alumina) femoral head. A zirconia femoral head was implanted in five dogs: one was sacrificed 12 months after implantation, two at 18 months, and two at 24 months. In each femoral head and polyethylene (PE) socket, the surface was observed by means of scanning electron microscopy (SEM); the mean articulation surface roughness on the femoral head and PE socket and the thickness of the PE socket were measured. Wear was not seen on the surface of either the zirconia or the alumina heads. In both groups, minute white spots on the smooth surface of the PE socket were visible by SEM. In the alumina and zirconia groups the mean roughness was 0.1 microm. The mean thickness of the PE socket was reduced by 0.2 mm in the alumina group. In the zirconia group it was reduced by 0.2 to 0.3 mm. However, the mechanical strength of zirconia is known to be greater than that of alumina and it may be possible to reduce the diameter of the femoral head. The smaller zirconia head may contribute to the reduction of the wear of the PE socket in an uncemented modular total hip system.

Animals↗
PubMed1999

Novel polymorphism of the 5-lipoxygenase activating protein (FLAP) promoter gene associated with asthma.

The human 5-lipoxygenase activating protein (FLAP) gene is one of the key genes involved in the production of the cysteinyl-leukotrienes. We studied novel polymorphism of the FLAP promoter gene and attempted to clarify the relationship between this polymorphism and asthma. We sequenced the FLAP promoter region, containing the -170 to +46-bp sequence from the translational start codon, and found two homozygotes of novel alleles in the polyadenyl region which showed 21 A repeats and 18 A repeats, respectively. The frequency of the 21 A repeats was 52/71 (73.2%) in asthmatics and 39/71 (54.9%) in control subjects. The difference between these frequencies was statistically significant (P = 0.035). This is the first report of FLAP promoter gene polymorphism associated with asthma. Our data suggest that FLAP promoter gene polymorphism might play a crucial role in the pathogenesis of asthma.

5-Lipoxygenase-Activating Proteins↗
PubMed1999

Differences of reconstitution process between tobacco mosaic virus and cucumber green mottle mosaic virus by synchrotron small angle X-ray scattering using low-temperature quenching.

The differences of the reconstitution process of tobacco mosaic virus (TMV) and its mutant, cucumber green mottle mosaic virus (CGMMV) were investigated by the solution X-ray scattering measurements with the synchrotron radiation source using low-temperature quenching. The reconstitution in an aqueous solution is completely stopped below 5 degrees C. The TMV and CGMMV assembly was traced by the small-angle X-ray scattering (SAXS) measurements at 5 degrees C on a series of solutions prepared by low-temperature quenching after incubation at 20 degrees C for an appropriate interval between 0 and 60 min. The SAXS results were analyzed by the Guinier plot, the Kratky plot and the distance distribution function. The incubation of RNA and protein of CGMMV did not reconstitute at the initial reaction stages below 5 min and then began to reconstitute gradually. After 60 min, the radius of gyration for CGMMV reconstitution process reached almost the value for the initial stage of TMV reconstitution process. This is due to the fact the formation of double-layered disk in CGMMV protein is much slower than in TMV protein.

Cold Temperature↗
PubMed1999

Peripheral lamellar keratoplasty for corneoscleral cyst: three case reports.

PURPOSE: To examine whether peripheral lamellar keratoplasty (LKP) using preserved cornea was effective for the treatment of corneoscleral cysts. METHODS: Three patients with corneoscleral cysts underwent peripheral lamellar keratoplasty. Two patients had no history of trauma or ocular surgery and were considered to have congenital cysts. The other patient had a history of strabismus surgery that had been performed 7 years previously. The anterior wall of the cysts was removed by trephination, and the epithelial membrane lining the posterior wall was peeled off. Lamellar corneal buttons obtained from preserved corneas then were put in place and secured with 8-10 interrupted sutures. In one case, because the cyst was large and extended to the pupillary axis, peripheral LKP was performed for removal of the scleral and peripheral corneal cyst, and the inner wall of the central corneal cyst was removed with vigorous irrigation and a spatula. RESULTS: Histologic examination showed that all of the cysts were lined with nonkeratinizing epithelial cells. In all three cases, cysts have not reformed after a 1-5-year follow-up. CONCLUSIONS: The cysts were lined in epithelial cells, and removal of these epithelial cells was considered to be important for the prevention of recurrence. Peripheral LKP is effective for the treatment of corneoscleral cysts, since this procedure removes displaced epithelial cells and reconstructs the thin part of the cornea and sclera.

Adolescent↗
PubMed1999

The Progression of Cavitation in Earlywood Vessels of Fraxinus mandshurica var japonica during Freezing and Thawing.

For an examination of the progression of cavitation in large-diameter earlywood vessels of a deciduous ring-porous tree, potted saplings of Fraxinus mandshurica var japonica Maxim. were frozen and then thawed. The changes in the amount and distribution of water in the lumina of the current year's earlywood vessels during the course of the freezing and thawing were visualized by cryo-scanning electron microscopy. When samples were frozen, most of the current year's earlywood vessels were filled with water. After the subsequent thawing, the percentage of cavitated current-year earlywood vessels gradually increased with time. All of the current year's earlywood vessels were cavitated within 24 h, and only limited amounts of water remained in the lumina of earlywood vessels. Similar cavitation of earlywood vessels was observed after thawing of frozen, excised stem pieces. In contrast, many vessels of the current year's latewood retained water in the lumina during freezing and thawing. These observations indicate that the cavitation of the current year's earlywood vessels is not produced during freezing but progresses during rewarming after freezing in F. mandshurica var japonica.

Journal Article↗
PubMed1999

[Evaluation of a multi-hospital cooperative study on the efficacy and safety of panipenem/betamipron (PAPM/BP) on elderly patients of respiratory infections].

The efficacy and safety of Panipenem/Betamipron (PAPM/BP) on elderly patients of respiratory infections was examined at 17 hospitals in a cooperative study. Among the 95 case, we examined the efficacy of the medication in 86 cases, and the safety in all 95 cases. Efficacy was confirmed in 81.3% of pneumonia patients, 57.7% of secondary-infection patients of chronic respiratory diseases, and 74.4% of the total. No significant difference was observed among each group according to age, comparing patients > or = 65 years old grouped by 5 years, or when broadly comparing groups < 75 years and > or = 75 years of age. The microbiological efficacy was 100% for Streptococcus pneumoniae, 80% for Staphylococcus aureus, 80% in Klebsiella pneumoniae; therefore, a very good disappearance rate of symptoms could be obtained in all major respiratory etiologic agents except Pseudomonas aeruginosa. In this study, we also examined other factors considered to affect the course of treatment for elderly patients of infectious diseases, namely the presence of absence of underlying diseases, the distinctness of infectious symptoms, the patient's condition before the appearance of infectious symptoms, and previous history of treatment with antimicrobial agents. For safety, the incidence rate of side effects was 14.7%, which was similar to the 16.9% in the developmental study. These two findings were also similar in content. No significant difference was observed among each age group, comparing patients > or = 65 years old grouped by 5 years, or comparing groups < 75 years and > or = 75 years of age. From the above evaluation, we consider PAPM/BP to be an effective drug for normal adult patients as well as elderly patients of respiratory infections.

Aged↗
PubMed1999

p38 mitogen-activated protein kinase can be involved in transforming growth factor beta superfamily signal transduction in Drosophila wing morphogenesis.

p38 mitogen-activated protein kinase (p38) has been extensively studied as a stress-responsive kinase, but its role in development remains unknown. The fruit fly, Drosophila melanogaster, has two p38 genes, D-p38a and D-p38b. To elucidate the developmental function of the Drosophila p38's, we used various genetic and pharmacological manipulations to interfere with their functions: expression of a dominant-negative form of D-p38b, expression of antisense D-p38b RNA, reduction of the D-p38 gene dosage, and treatment with the p38 inhibitor SB203580. Expression of a dominant-negative D-p38b in the wing imaginal disc caused a decapentaplegic (dpp)-like phenotype and enhanced the phenotype of a dpp mutant. Dpp is a secretory ligand belonging to the transforming growth factor beta superfamily which triggers various morphogenetic processes through interaction with the receptor Thick veins (Tkv). Inhibition of D-p38b function also caused the suppression of the wing phenotype induced by constitutively active Tkv (TkvCA). Mosaic analysis revealed that D-p38b regulates the Tkv-dependent transcription of the optomotor-blind (omb) gene in non-Dpp-producing cells, indicating that the site of D-p38b action is downstream of Tkv. Furthermore, forced expression of TkvCA induced an increase in the phosphorylated active form(s) of D-p38(s). These results demonstrate that p38, in addition to its role as a transducer of emergency stress signaling, may function to modulate Dpp signaling.

Animals↗
PubMed1999

Genomic organization of the 260 kb surrounding the waxy locus in a Japonica rice

The present study was carried out to characterize the molecular organization in the vicinity of the waxy locus in rice. To determine the structural organization of the region surrounding waxy, contiguous clones covering a total of 260 kb were constructed using a bacterial artificial chromosome (BAC) library from the Shimokita variety of Japonica rice. This map also contains 200 overlapping subclones, which allowed construction of a fine physical map with a total of 64 HindIII sites. During the course of constructing the map, we noticed the presence of some repeated regions which might be related to transposable elements. We divided the 260-kb region into 60 segments (average size of 5.7 kb) to use as probes to determine their genomic organization. Hybridization patterns obtained by probing with these segments were classified into four types: class 1, a single or a few bands without a smeared background; class 2, a single or a few bands with a smeared background; class 3, multiple discrete bands without a smeared background; and class 4, only a smeared background. These classes constituted 6.5%, 20.9%, 3.7%, and 68.9% of the 260-kb region, respectively. The distribution of each class revealed that repetitive sequences are a major component in this region, as expected, and that unique sequence regions were mostly no longer than 6 kb due to interruption by repetitive sequences. We discuss how the map constructed here might be a powerful tool for characterization and comparison of the genome structures and the genes around the waxy locus in the Oryza species.

Journal Article↗
PubMed1999

Control of the dispersing process and pharmacokinetics in rats for lipid A analogue, E5531.

E5531 is a synthetic disaccharide analogue of lipid A which has a low toxicity but retains the ability to reduce production of tumour necrosis factor. This analogue has potential for use in the treatment of septic shock. An injectable formulation of E5531 would be useful, but dispersion in aqueous solution is a problem. In the present study the dispersing process for E5531 was evaluated using the pH-jump method (pH 11.0-->7.3). The size of the aggregates was decreased (reaching 20 nm) with increasing dispersing time in 0.003 M NaOH (pH 11.0). The membrane fluidity of the aggregates increased with increasing dispersing time. When prepared by the normal dilution method (pH 7.3-->7.3), the size of the aggregates remained constant at 140 nm and the membrane fluidity was smaller than that of samples prepared by the pH-jump method. This indicates that during dispersing at basic pH, the hydration proceeded in a normal manner, but then stopped, just after adjustment of the pH to 7.3. This suggests that the degree of hydration of the membrane is dependent on the dispersing time at pH 11.0. Using samples with different degrees of hydration and different membrane fluidity prepared by the pH-jump method, the pharmacokinetics and stability of the aggregates were evaluated after intravenous injection into rats. The data thus obtained confirmed that the membrane fluidity was correlated with the pharmacokinetics and stability in rat plasma. It was concluded that the pharmacokinetics of E5531 in rats can be controlled by changing the degree of hydration and membrane fluidity by means of using different dispersing times in alkaline solution (pH 11.0).

Animals↗