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Biomedical subjects

Y Taniguchi

Publications and source records attributed to Y Taniguchi.

At least 73 records · Page 4Linked to original sources
PubMed2001

The anatomy of the lacrimal portion of the orbicularis oculi muscle (tensor tarsi or Horner's muscle).

Horner's muscle (the palpebral part of the orbicularis oculi muscle) has a fan-shaped origin in the lacrimal bone. Its muscle fibers are oriented from 160 to 210 degrees relative to the ear-eye plane and converge towards the medial palpebral commissure. Then the muscle divides into superior and inferior bundles of fibers. Some of the lower fibers participate in the formation of the superior bundle and some of the higher fibers participate in the formation of the inferior bundle and, thus, some of Horner's muscle is twisted. Each bundle courses laterally to the lateral palpebral commissure and has three insertions. The first insertion is located at the medial margin of the tarsi. The second insertion is into the subcutaneous tissue along the palpebral margins. Minute fascicles of Horner's muscle are fastened to the palpebral margins. The third insertions are into the lateral palpebral ligament and subcutaneous connective tissue of the lateral commissure. Serial histological sections of a fetus at 14 to 16 weeks gestation revealed that the extent of the envelope formed by Horner's muscle around the lacrimal canaliculus decreases gradually from the lacrimal papilla to the lacrimal sac. The various observations suggest the following roles for Horner's muscle: (1) it closes the medial canthus of the eye and closes the lacrimal punctum; (2) it pulls the tarsus medially; (3) it tautens the palpebral margins and presses against the eyeball; and (4) it squeezes the lacrimal canaliculus with a decreasing gradient of pressure from the lacrimal papilla to the lacrimal sac. These actions are likely to be important for the flow of lacrimal fluid in the lateral to medial direction on the eyeball, for maintenance of the thickness of tear film over the cornea, for opening and closing of the lacrimal punctum, and for passage of the lacrimal fluid from the canaliculus to the sac. Horner's muscle appears, thus, to be a muscle of prime importance in all phases of the flow of lacrimal fluid.

Aged↗
PubMed2001

Ultrasonic pleural debridement of empyema.

Thoracic decortication is a common procedure for empyema. However, effective dissection without injuring the lung parenchyma is sometimes difficult. We introduce a new technique using an ultrasonic surgical unit (USUTM) to search the dissection plane and simultaneously perform pleural debridement and irrigation with minimal injury of the lung parenchyma. USUTM was used on 5 patients with acute empyema with fibrino-purulent phase and good clinical course was achieved. This procedure facilitates effective pleural debridement under either thoracoscopy or conventional thoracotomy.

Adolescent↗
PubMed2001

Aortic valve repair of congenital bicuspid aortic valve associated with aneurysm of the ascending aorta.

Two unusual cases of congenital bicuspid aortic valve associated with aneurysm of the ascending aorta are reported. One patient with a 7-cm ascending aortic dilatation and aortic regurgitation (AR) (II/IV), and another with a 6-cm ascending aorta and AR (III/IV), presented for treatment. Replacement of the ascending aorta and aortic valve repair were performed in both cases. Aortic valve repair included resection of the raphe, leaflet plication and subcommissural annuloplasty. Both patients had satisfactory results in the early postoperative period. Despite the promising outcomes after surgery in these patients, long-term changes in valve function and durability remain unknown. Additional close observation and monitoring are required before the procedure can be recommended as the standard of care.

Aged↗
PubMed2000

Antigen-presenting capability of glial cells under glioma-harboring conditions and the effect of glioma-derived factors on antigen presentation.

The antigen-presenting capability of syngeneic rat glial cells was investigated under glioma-harboring conditions. Microglia induced a significant proliferation of glioma-primed splenocytes, but astrocytes did not. Furthermore, astrocytes suppressed the accessory cell function of microglia. The presence of both indomethacin and anti-interleukin (IL)-10 neutralizing antibody during priming of microglia enhanced splenocyte proliferation. The glioma culture supernatants down-regulated the interferon-gamma-induced expression of major histocompatibility complex class II molecules on microglia. The down-regulation was blocked by indomethacin and anti-IL-10 antibody. The results suggest that microglia but not astrocytes may function as antigen-presenting cells in glioma, and that glioma may suppress the antigen-presenting abilities of microglia.

Animals↗
PubMed2000

Characterization of S818L mutation in HERG C-terminus in LQT2. Modification of activation-deactivation gating properties.

We examined the mechanism(s) for HERG channel dysfunction in an S818L mutation in the HERG C-terminus using the heterologous expression system in Xenopus oocytes. Injection of S818L cRNA alone did not produce expressed currents. Coinjection of an equal amount of S818L cRNA with wild-type (WT) cRNA into oocytes did not exhibit apparent dominant-negative suppression. However, coinjection of excess amounts of S818L cRNAs with WT cRNA into oocytes decreased HERG current amplitudes and shifted the voltage dependence of activation to negative potentials, accelerated its activation and deactivation. The data suggest that S818L alone cannot form functional channels, whereas S818L subunits can, at least in part, coassemble with WT subunits to form heterotetrameric functional channels, and imply that the HERG C-terminus may contain a domain involving the activation-deactivation process of the channel. These findings may provide new insights into the structure-function relationships of the HERG C-terminus.

Amino Acid Substitution↗
PubMed2000

Human monoclonal antibody 98-6 reacts with the fusogenic form of gp41.

A mixture of two peptides from gp41 (N36 and C34) forms an alpha-helical structure that is thought to represent the fusogenic form of gp41. A human anti-gp41 monoclonal antibody (mAb 98-6), generated from the cells of an infected individual, reacted poorly with C34, but binding was strongly enhanced when N36 was added, indicating that the mAb reacts with a conformational epitope present in the fusogenic structure formed by the interaction of peptides N36 and C34. The epitope recognized by mAb 98-6 was found in lysates of virions on oligomeric forms of gp41 (dimers, trimers, and tetramers). On infected cells, the epitope was present as oligomers of gp41, as monomers of gp41, and as part of the envelope polyprotein gp160, obtained after biotinylation of intact cells, which were then lysed and immunoprecipitated with various mAbs. In lysates of infected cells, the epitope was present as part of both monomeric gp41 and gp160. These studies demonstrate that infected humans can respond to the fusogenic form of gp41 and that the anti-gp41 mAb studied here recognizes a conformational epitope formed by the interaction of two regions of gp41, which forms an alpha-helical bundle. This epitope is found on several forms of gp41 as it occurs in virions, on the surface of infected cells, and in infected cells.

Antibodies, Monoclonal↗
PubMed2000

Identification and characterization of TMEFF2, a novel survival factor for hippocampal and mesencephalic neurons.

We have identified a novel mammalian gene, TMEFF2, that encodes a putative transmembrane protein containing two follistatin-like domains and one epidermal growth factor (EGF)-like domain. The TMEFF2 gene is predominantly expressed in the brain. In situ hybridization analysis revealed that TMEFF2 is widely expressed in the brain, including hippocampal cornu ammonis, dentate gyrus, and substantia nigra pars compacta. We evaluated the survival effect of TMEFF2 using primary cultured neurons from several regions of fetal rat brain following treatment with a recombinant TMEFF2 protein fragment consisting of the putative extracellular domain. TMEFF2 increased survival of neurons from the hippocampus and midbrain, but not from the cerebral cortex, indicating that the survival effects of TMEFF2 are specific to certain cell types. Recombinant TMEFF2 also promoted survival of mesencephalic dopaminergic neurons. Together, these findings suggest that TMEFF2 may be a novel survival factor for hippocampal and mesencephalic, but not for cortical, neurons.

Amino Acid Sequence↗
PubMed2000

IgE-reactivity to major Japanese cedar (Cryptomeria japonica) pollen allergens (Cry j 1 and Cry j 2) by ELISA in dogs with atopic dermatitis.

The present study investigated IgE-reactivity to two major Japanese cedar (Cryptomeria japonica, C. japonica) pollen allergens (Cry j 1 and Cry j 2) in dogs with atopic dermatitis by use of a fluorometric ELISA. The serum samples from 27 dogs that showed IgE-sensitivity to crude C. japonica pollen allergen by ELISA were tested for specific IgE to the two major allergens. All 27 dogs had anti-Cry j 1 IgE, and 10 (37%) had anti-Cry j 2 IgE. Inhibition of binding of dog specific IgE to crude C. japonica pollen allergen was carried out by addition of Cry j 1. When serum samples containing anti-Cry j 1 IgE but no anti-Cry j 2 IgE were incubated with Cry j 1, specific IgE binding to crude C. japonica pollen allergen was almost abolished. These findings suggest that Cry j 1 is a major allergen in dogs.

Animals↗
PubMed2000

Grain Survival in Supernova Remnants and Herbig-Haro Objects.

By using the [Fe ii] lambda8617/[O i] lambda6300 flux ratio, we demonstrate that most of the interstellar dust grains survive in shocks associated with supernova remnants and Herbig-Haro objects. The [Fe ii]/[O i] flux ratio is sensitive to the gas-phase Fe/O abundance ratio but is insensitive to the ionization state, temperature, and density of the gas. We calculate the [Fe ii]/[O i] flux ratio in shocks and compare the results with the observational data. When only 20% of iron is in the gas phase, the models reproduce the observations most successfully. This finding is in conflict with the current consensus that shocks destroy almost all the grains and that approximately 100% of metals are in the gas phase. We comment on previous works on grain destruction and discuss why grains are not destroyed in shocks.

Journal Article↗
PubMed2000

Genetic subtypes of HIV type 1 in Republic of Congo.

To assess the molecular epidemiology of HIV-1 in Republic of Congo (Congo), we investigated 29 HIV-1s obtained from 82 Congolese AIDS and ARC patients in 1996 and 1997. Part of the env region including the V3 loop was phylogenetically analyzed. The genotypes observed were varied: of 29 specimens, 12 (41 %) were subtype A, 1 (3%) was subtype D, 6 (21%) were subtype G, 6 (21%) were subtype H, 2 (7%) were subtype J, and 2 (7%) could not be classified as any known subtypes (U, unclassified). The heterogeneous profile of HIV-1 infection was different from the profiles of neighboring Central African countries. These data show that subtypes G and H as well as subtype A were circulating with high prevalence. The fact that new genetic subtypes (J and U) are circulating indicates a need for a greater surveillance for these subtypes both in Congo as well as in other parts of the world.

AIDS-Related Complex↗
PubMed2000

Superwind Model of Extended Lyalpha Emitters at High Redshift.

We propose a new model for the extended Lyalpha blobs found recently at high redshift (z approximately 3). The observational properties of these blobs are as follows: (1) the observed Lyalpha luminosities are approximately 1043 h-2 ergs s-1, (2) they appear elongated morphologically, (3) their sizes amount to approximately 100 kpc, (4) the observed line widths amount to approximately 1000 km s-1, and (5) they are not associated with strong radio continuum sources. All these observational properties seem to be explained in terms of galactic winds driven by successive supernova explosions shortly after the initial burst of massive star formation in the galactic centers. The observed number density of Lyalpha blobs ( approximately 3.4x10-5 h3 Mpc-3) may be explained if their present-day counterparts are elliptical galaxies with a luminosity above approximately 1L*.

Journal Article↗
PubMed2000

Three-component coupling of acylphosphonates and two carbonyl compounds promoted by low-valent samariums: one-Pot synthesis of beta-hydroxyphosphonates

Three-component coupling of acylphosphonates and two carbonyl compounds leading to beta-hydroxyphosphonates has been achieved with low-valent samariums. Thus, acylphosphonates reacted with aldehydes in the presence of semicatalytic amounts of samarium metal or SmI(2) to give acyloxyphosphonates in good yields. The second coupling reaction of the acyloxyphosphonates with aldehydes or ketones promoted by SmI(2) afforded beta-hydroxyphosphonates instead of olefins. Moreover, these two reactions could be carried out in one pot.

Journal Article↗
PubMed2000

Proliferation and differentiation of pituitary corticotrophs during the fetal and postnatal period: a quantitative immunocytochemical study.

To study the proliferation and differentiation of pituitary corticotrophs, we administered bromodeoxyuridine (BrdU) to pregnant rats at 15.5-21.5 days of gestation and to rat pups at 3, 7, and 28 days after birth. The pituitary sections of fetuses and pups were consecutively immunostained with anti-BrdU and anti-adrenocorticotropic hormone (ACTH) to detect proliferating cells and corticotrophs, respectively. The number of cells labeled with BrdU, ACTH, or both were counted. The diameters of their nuclei and the volume of the pituitary were measured. The BrdU-positive cells were around 76,000-96,000/mm3 during the period studied. The corticotrophs were first detected in the fetus at 15.5 days and they increased during the fetal and postnatal periods. The double-labeled cells were first detected in the 17.5-day fetus. They increased markedly at 19.5 days and comprised about one-quarter of the corticotrophs that increased in 24 h at this stage. These results indicate that: (1) at 15.5-18.5 days the corticotrophs were derived almost exclusively from undifferentiated cells; (2) during the later fetal and early postnatal periods, the proliferation of existing corticotrophs contributed, at least in part, to their increase; (3) about 1/20 of proliferating cells differentiated to corticotrophs when their increase was required.

Adrenocorticotropic Hormone↗
PubMed2000

Prognostic impact of cathepsin B and matrix metalloproteinase-9 in pulmonary adenocarcinomas by immunohistochemical study.

The expression of Cathepsin B (CB) and matrix metalloproteinase-9 (MMP-9) in extirpated tissues of adenocarcinomas in non-small cell lung cancer from 90 cases was investigated immunohistologically, and the correlations between the extent of the expression and the clinicopathological features were assessed for investigating the process of tumor metastasis. It is important to reveal the mechanisms of destruction of the basal membrane and infiltration of tumor cells at the primary lesion. Sections were obtained from 10%-formalin-fixed and paraffin-embedded tissues. They were reacted with an anti-human CB polyclonal antibody or an anti-human MMP-9 polyclonal antibody. Of 90 patients, 58 (64.4%) and 39 (48.3) cases were found to be positive for CB and MMP-9 expression, respectively. A significantly higher extent of the CB expression was observed in the tissues of patients who showed postoperative recurrence of the tumor (P = 0.013). Especially, a similar observation was obtained among early cases of T1N0 (P = 0.023). In contrast, no such tendency was demonstrated in the expression profile of MMP-9. Furthermore, the enzyme expressions were compared among different types of metastases. Patients with higher extents of CB expression tended to show significantly higher rates of hematogenous and intrapulmonary metastases (P = 0.023 and P = 0.010, respectively). However, there was no significant correlation between MMP-9 expression and the prognostic factor of the patients. Therefore, we suggested that evaluation of CB expression in the tumor tissue might be useful as a postoperative prognostic factor of pulmonary adenocarcinoma. Especially, early cancer of T1N0 cases showing higher expression of CB may need postoperative adjuvant chemotherapy.

Adenocarcinoma↗
PubMed2000

Raman study on conformational equilibria of fluoroacetone in aqueous solutions.

The effects of water and heavy water on conformational equilibria of fluoroacetone have been investigated via Raman spectroscopy. Additional Raman bands have been observed in the C-F stretching and the C-C-C symmetric stretching regions for the aqueous solutions. Based on enthalpy and volume differences between the conformers, these bands are assigned to the syn conformer which has hydrogen bonds between the fluorine atom and water molecules (syn' conformer). The number of H2O molecules binding to the syn' conformer is estimated to be 2.4 from the concentration dependence of the spectrum. The enthalpy and the volume differences between the cis and syn conformers in the aqueous solutions show anomalous values in comparison with those in organic solvents. We discuss these thermodynamic behaviors from the viewpoint of the hydration structures of fluoroacetone.

Acetone↗
PubMed2000

Characterisation of gene expression in bovine adipose tissue before and after fattening.

It has been reported that fattening causes bovine adipose tissue development associated with an enlargement in adipocyte cell size. As a first study to elucidate mechanisms of bovine adipose tissue development during fattening, our experiment was designed to characterise gene expression in bovine adipose tissue before and after fattening. We randomly isolated a large number of cDNA clones derived from bovine adipose tissue before and after fattening. Sequence analysis of the isolated clones showed that 3 and 10 clones from before and after fattening, respectively, correspond to genes related to adipocyte development and/or function in the adipose tissue. In addition, we isolated cDNA clones that possess negative signal by hybridising the cDNA population from the adipose tissue after fattening with that before fattening as a probe. As a result, we identified five types of transcripts observed in the adipose tissue after fattening but not before fattening. Two of the five are likely to encode bovine orthologs of phospholipase A2 and RNA helicase p68, while the other three represent unknown genes. Further functional investigation of the identified genes might lead to elucidation of mechanisms of bovine adipose tissue development during fattening.

Adipocytes↗
PubMed2000

Identification and characterization of a group 2 conifer pollen allergen from Chamaecyparis obtusa, a homologue of Cry j 2 from Cryptomeria japonica.

BACKGROUND: Not only Cryptomeria japonica (Japanese cedar) pollen but also that of Chamaecyparis obtusa (Japanese cypress) induces the allergic symptoms of Japanese cedar pollinosis. However, allergens from C. obtusa pollen have not been as well characterized as those from C. japonica pollen. OBJECTIVE: We sought to identify and characterize a homologue of the second major allergen of C. japonica pollen, Cry j 2, from the pollen of C. obtusa. METHODS: An allergen homologous to Cry j 2 was identified in C. obtusa pollen extract by immunoblot analysis, probed with anti-Cry j 2 monoclonal antibodies and purified by a series of column chromatographic steps. RESULTS: The allergen isolated from the extract showed a slightly diffuse band of 45 kDa and closely spaced double-bands of 42 and 45 kDa on SDS-PAGE, under reducing and non-reducing conditions, respectively; the bands were approximately 5-7 kDa larger than those of Cry j 2. In 24 of 30 residues, the N-terminal amino acid sequence of the allergen was identical with corresponding sequence in Cry j 2. Most patients with pollinosis who were IgE antibody-positive to Cry j 2 were shown to be IgE antibody-positive to this allergen, and the IgE antibody levels to both allergens were highly correlated. CONCLUSION: The results indicate that the allergen isolated from C. obtusa pollen in this study is a homologue of Cry j 2. The allergen was designated as Cha o 2 according to the WHO/IUIS Allergen Nomenclature Subcommittee recommendation.

Allergens↗