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Biomedical subjects

M Ishihara

Publications and source records attributed to M Ishihara.

At least 199 records · Page 11Linked to original sources
PubMed1994

[Analysis of susceptibility genes in sarcoidosis].

In order to investigate immunogenetic mechanisms in the pathogenesis of sarcoidosis, sixty-three patients with sarcoidosis, who were diagnosed histologically, were tested for HLA antigens. Controls consisted of 120 healthy subjects. A lymphocyte cytotoxicity test was used for typing HLA-A, -B, -C, -DQ and -DR antigens. HLA-DP genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The frequencies of HLA-DR52 and its associated antigens (HLA-DR5, -DR6 and -DR8) were significantly increased in the patients as compared to the control subjects. On the contrary, the frequencies of HLA-DR53, -DR1, and -DR4 were significantly decreased in the patients. The frequency of HLA-DPB1*0402 was significantly lower in the patients. No significant differences were observed in HLA-DQ antigens. These results suggest that HLA-DR52 associated antigens contribute to the susceptibility to sarcoidosis in Japanese.

Adolescent↗
PubMed1994

Stereotactic PET atlas of the human brain: aid for visual interpretation of functional brain images.

UNLABELLED: In the routine analysis of functional brain images obtained by PET, subjective visual interpretation is often used for anatomic localization. To enhance the accuracy and consistency of the anatomic interpretation, a PET stereotactic atlas and localization approach was designed for functional brain images. METHODS: The PET atlas was constructed from a high-resolution [18F]fluorodeoxyglucose (FDG) image set of a normal volunteer (a 41-yr-old woman). The image set was reoriented stereotactically, according to the intercommissural (anterior and posterior commissures) line and transformed to the standard stereotactic atlas coordinates. Cerebral structures were annotated on the transaxial planes by using a proportional grid system and surface-rendered images. The stereotactic localization technique was applied to image sets from patients with Alzheimer's disease, and areas of functional alteration were localized visually by referring to the PET atlas. RESULTS: Major brain structures were identified on both transaxial planes and surface-rendered images. In the stereotactic system, anatomic correspondence between the PET atlas and stereotactically reoriented individual image sets of patients with Alzheimer's disease facilitated both indirect and direct localization of the cerebral structures. CONCLUSION: Because rapid stereotactic alignment methods for PET images are now available for routine use, the PET atlas will serve as an aid for visual interpretation of functional brain images in the stereotactic system. Widespread application of stereotactic localization may be used in functional brain images, not only in the research setting, but also in routine clinical situations.

Adult↗
PubMed1993

Regulation of biosynthesis of the basic fibroblast growth factor binding domains of heparan sulfate by heparan sulfate-N-deacetylase/N-sulfotransferase expression.

Heparan sulfate-N-deacetylase/N-sulfotransferase catalyzes both the N-deacetylation and N-sulfation reactions that initiate the modification of the oligosaccharide backbone of heparan sulfate (HS). The glycosaminoglycan polymer appears to modulate the activity of growth factors by mediating their initial binding. To understand how the biosynthesis of these binding sites is regulated, a rat liver-derived cDNA encoding the above activities was overexpressed in a COS cell mutant (CM-15) that has reduced levels of the enzyme and binds poorly to immobilized basic fibroblast growth factor (bFGF). This resulted in increased synthesis of sulfated blocks of decasaccharide size or longer. These blocks exhibited high affinity binding to bFGF and contained a high content of 2-O-sulfated iduronate and at least five consecutive N-sulfated disaccharides. An increase in the synthesis of these high affinity blocks was not seen in transfected wild-type COS cells even though they showed a 4-fold increase of both enzyme activities, suggesting that once sufficient levels of highly sulfated blocks of saccharides with high affinity for bFGF are attained, no further synthesis of these domains occurs.

Amidohydrolases↗
PubMed1993

A single protein catalyzes both N-deacetylation and N-sulfation during the biosynthesis of heparan sulfate.

Heparan sulfate is a highly sulfated carbohydrate polymer that binds to and modulates the activities of numerous proteins. The formation of these protein-binding domains in heparan sulfate is dependent on a series of biosynthetic reactions that modify the polysaccharide backbone; the initiating and rate-limiting steps of this process are the N-deacetylation and N-sulfation of N-acetylglucosamine residues in the polymer. We now report that in the rat liver, biosynthesis of heparan sulfate utilizes a single protein that possesses both N-deacetylase and N-sulfotransferase activities. This was accomplished by demonstrating that both activities resided in a purified soluble fusion protein containing the Golgi-lumenal portion of the enzyme. We propose that this protein be renamed the rat liver Golgi heparan sulfate N-deacetylase/N-sulfotransferase.

Acetylglucosamine↗
PubMed1993

Preparation of affinity-fractionated, heparin-derived oligosaccharides and their effects on selected biological activities mediated by basic fibroblast growth factor.

Homogeneously sized, heparin-derived oligosaccharides were prepared from heparin following partial depolymerization with nitrous acid, reduction with sodium borohydride, and fractionation by gel permeation chromatography. The resulting pools of di-, tetra-, hexa-, octa-, and decasaccharides were sequentially applied to an affinity column of human recombinant basic fibroblast growth factor (bFGF) covalently attached to Sepharose 4B and further fractionated into subpools based on their elution from this column in response to gradients of sodium chloride. In general, pools of smaller heparin-derived oligosaccharides required relatively lower salt concentration for complete elution, and pools of larger oligosaccharides required higher salt concentration. The homogeneously sized pools and affinity-fractionated subpools of heparin-derived oligosaccharides were quantitatively assessed as inhibitors or enhancers of specific bFGF-mediated biological activities in five separate assay systems as follows: assay 1, to compete with human lymphoblastoid cells expressing syndecan (RO-12 UC cells) for binding to bFGF-coated wells (Ishihara, M., Tyrrell, D.J., Kiefer, M.C., Barr, P.J., and Swiedler, S.J. (1992) Anal. Biochem. 202, 310-315); assay 2, to inhibit 125I-bFGF binding to "low affinity sites" of adrenocortical endothelial (ACE) cells; assay 3, to inhibit bFGF-induced proliferation of ACE cells; assay 4, to support mitogenic activity of bFGF in a growth stimulation assay of chlorate-treated ACE cells; and assay 5, to enhance the in vitro interaction between 125I-bFGF and the recombinant extra-cellular domain of FGF high affinity receptor. The data derived from the five assay systems demonstrated that heparin-derived hexa- and octasaccharides inhibited the interaction between cell surface heparan sulfate proteoglycan and bFGF (assays 1 and 2) and bFGF-induced proliferation of ACE cells (assay 3) but were unable to enhance the binding of bFGF to its high affinity receptor in vitro (assay 5) or to support bFGF-induced mitogenesis in ACE cells (assay 4). These two activities required at least a decasaccharide with high affinity for bFGF.

Animals↗
PubMed1993

Structure and biological activities of a heparin-derived hexasaccharide with high affinity for basic fibroblast growth factor.

We demonstrated previously that heparin-derived hexasaccharides are the smallest fragments of the polysaccharide with comparable basic fibroblast growth factor (bFGF)-modulating activity in vitro (Ishihara, M., Tyrrell, D.J., Stauber, G.B., Brown, S., Cousens, L., and Stack, R.J. (1993) J. Biol. Chem. 268, 4675-4683. In this report, a specific hexasaccharide having high affinity for recombinant human bFGF was isolated and its structure deduced by analysis of its reduced disaccharide products after treatment with nitrous acid at pH 1.5, and by 1H NMR spectroscopy. The hexasaccharide has the structure [IdoA(2-OSO3)alpha 1-4GlcNSO3(6-OSO3)alpha 1-4]2IdoA(2-OSO3)alpha 1-4 AManR(6-OSO3). The hexasaccharide effectively inhibits the binding of syndecan-transfected RO-12 UC cells to bFGF-coated wells (Ishihara, M., Tyrrell, D.J., Kiefer, M.C., Barr, P.J., and Swiedler, S.J. (1992) Anal. Biochem. 202, 310-315), prevents the binding of 125I-bFGF to confluent monolayers of adrenocortical endothelial (ACE) cells, and inhibits the bFGF-dependent proliferation of ACE cells. Unlike the heparin from which it was derived, however, the hexasaccharide cannot promote the binding of 125I-bFGF to a recombinant high affinity bFGF receptor (flg) or restore the bFGF-dependent proliferative response to ACE cells grown in the presence of 5 mM sodium chlorate. Collectively, these data indicate that a hexasaccharide can be as effective as heparin as an antagonist of bFGF-mediated cell mitogenesis.

Animals↗
PubMed1993

Anti-oncogenic and oncogenic potentials of interferon regulatory factors-1 and -2.

Interferon regulatory factor-1 (IRF-1), a transcriptional activator, and IRF-2, its antagonistic repressor, have been identified as regulators of type I interferon and interferon-inducible genes. The IRF-1 gene is itself interferon-inducible and hence may be one of the target genes critical for interferon action. When the IRF-2 gene was overexpressed in NIH 3T3 cells, the cells became transformed and displayed enhanced tumorigenicity in nude mice. This transformed phenotype was reversed by concomitant overexpression of the IRF-1 gene. Thus, restrained cell growth depends on a balance between these two mutually antagonistic transcription factors.

3T3 Cells↗
PubMed1993

Pulsed-field gel electrophoretic analysis of Campylobacter jejuni DNA for use in epidemiological studies.

The cleavage patterns of the genomic DNA of 42 clinical isolates of Campylobacter jejuni determined by pulsed-field gel electrophoresis (PFGE) were compared with their Lior and TCK serotypes. The fragment patterns of DNA obtained with SalI and SmaI restriction enzymes did not always accord with the corresponding serotypes but strains of the same serotype could be further divided into subtypes by their cleavage patterns. This PFGE method may prove useful for subclassifying C. jejuni.

Campylobacter jejuni↗
PubMed1993

The distribution of eosinophil cationic protein positive eosinophils in the nasal mucosa of the nasal allergy patients.

The relationship between the distribution of eosinophils and epithelial damage of the nasal mucosa in nasal allergy was investigated by means of hematoxylin and eosin staining and a technique of immunohistochemistry using the anti-human EG2 mouse monoclonal antibody that reacts with the secreted form of eosinophil cationic protein (ECP). Nasal mucosa tissue of 26 adult nasal allergy patients and of 24 adult non-allergic rhinitis patients was removed surgically. Eosinophilia in the nasal mucosa of the allergy group was greater than that in the non-allergy group. A great number of ECP positive eosinophils accumulating in the nasal mucosa of the allergy group were mostly degranulated at the superficial layer of the lamina propria. Desquamation of the epithelium was observed mainly in the area of eosinophilia with degranulation of the secreted form of ECP in the nasal allergy group.

Adult↗
PubMed1993

Seasonal variations of nasal resistance in allergic rhinitis and environmental pollen counts.

We made measurements of nasal airway resistance in a patient with Japanese cedar pollinosis and also measured the environmental pollen counts under different exposure conditions. In the season of high Japanese cedar pollen counts in Japan values of mean nasal airway resistance were significantly increased, remained elevated for 2 months after the season, and eventually decreased. In the season of low pollen counts, the mean values of nasal airway resistance measurements were increased during the season but decreased more rapidly after the season. In a year with no exposure to the environmental allergen because the subject lived out of Japan, the mean nasal airway resistances were relatively increased closely in phase with the Japanese cedar pollen season.

Adult↗
PubMed1993

Seasonal variations of nasal resistance in allergic rhinitis and environmental pollen counts. II: Efficacy of preseasonal therapy.

We gave Mao-bushi-saishin-to, a Chinese blended medicine, and azelastine to an adult patient with hay fever due to Japanese cedar pollen and measured nasal resistance and ambient floating pollen counts throughout the time of Japanese cedar pollination in separated years. In the patient Mao-bushi-saishin-to was effective against preseasonal increases in nasal airway resistance but could not control severe episodes of allergic rhinitis caused by high dose exposure to Japanese cedar pollen and also perhaps caused by a priming effect. Azelastine inhibited both pre- and post-seasonal increases in nasal airway resistance but not only on high pollen counts days.

Adult↗
PubMed1993

Selective impairment of the synthesis of basic fibroblast growth factor binding domains of heparan sulphate in a COS cell mutant defective in N-sulphotransferase.

N-Sulphation is a key step in the overall sulphation of heparan sulphate. We have isolated a COS cell-derived mutant, CM-15, that is impaired in its ability to bind to basic fibroblast growth factor (bFGF) and has a 2- to 3-fold reduction in N-sulphotransferase activity [Ishihara et al., (1992a) Anal. Biochem., 206, 400-407]. We now provide structural evidence that CM-15 is selectively impaired in the synthesis of highly sulphated regions or 'blocks' that display high-affinity binding to bFGF; these are completely N-sulphated blocks of decasaccharide or greater length that are enriched in O-sulphate groups. The synthesis of sulphated blocks that did not show high affinity to the growth factor was relatively unimpaired in the mutant cells; this included fully N-sulphated octamer (or smaller) blocks and, unexpectedly, decasaccharide or larger blocks that were poorly O-sulphated. In the latter fraction, the failure to form high-affinity binding regions was the result of a failure to stimulate O-sulphation rather than N-sulphation in CM-15 cells. In agreement with other studies, disaccharide analysis of the wild-type-derived sulphated blocks suggested that 2-O-sulphation of iduronate residues in the polymer was a necessary element to produce a high-affinity binding sequence once N-sulphation was completed in the decasaccharide or larger fraction. These results suggest that a selective reduction in both N- and O-sulphation in the larger blocks produced by CM-15 cells is a consequence of the reduction of N-sulphotransferase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding Sites↗
PubMed1993

33-kDa peptides prepared from chicken gizzard smooth muscle bundle both actin and desmin filaments in vitro.

A group of 33-kDa peptides was prepared from chicken gizzard. Gizzard smooth muscle was extracted with Hasselbach-Schneider's high ionic strength solution. The extract was fractionated by ammonium sulfate precipitation. The soluble fraction obtained at 60% ammonium sulfate saturation was dialyzed against 0.1 M KCl. The precipitate formed during the dialysis mainly contained 33-kDa peptides. On SDS-PAGE, two major bands and one minor band were stained reddish purple by Coomassie Brilliant Blue R-250. These peptides, which were insoluble in physiological salt solutions, bundled not only actin filaments but also desmin filaments. Actin was markedly coprecipitated with the 33-kDa peptides on the usual centrifugation at 22,000 x g.

Actins↗