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Biomedical subjects

Y Yanagihara

Publications and source records attributed to Y Yanagihara.

At least 181 records · Page 10Linked to original sources

Automatic detection method of stenotic lesions in coronary cineangiograms.

A new image processing procedure enabling the automatic detection of coronary artery stenoses by cineangiography was developed. Detection of stenoses was performed using computer image processing by the following procedure. The path of the arteries was extracted by a subtraction method. The thresholding image was obtained from the subtraction image, and converted to a 'thinning' image, which represented the center line of the artery. For measurement of the arterial diameter, the vessel edges were determined by unilateral Gaussian fit to profile curves in sections perpendicular to the center line. Stenoses could then be detected on the basis of the normal diameter of artery estimated by Hough transformation. This method facilitates the detection of stenotic lesions from coronary cineangiograms.

Cineangiography↗

Immunopharmacological actions of an extract isolated from inflamed skin of rabbits inoculated with Vaccinia virus (Neurotropin)--II. Restorative effect on immune responses through the recovery of IL-2 production in aging mice.

To examine the immunopharmacological actions of an extract isolated from inflamed skin of rabbits inoculated with Vaccinia virus (Neurotropin), its effect on the immune responses in aging BALB/c mice was examined. Neurotropin clearly restored the decreasing T-cell-dependent immune responses such as delayed-type hypersensitivity (DTH) response and plaque-forming cells (PFC) response to sheep red blood cells (SRBC) when administered i.p. from 13 months old (mo) to 16 mo. However, Neurotropin administration from 2 to 5 mo had no effect on the immune responses of young animals. Neurotropin administration from 13 to 16 mo restored not only the T-cell proliferation of spleen cells induced by concanavalin A (Con A) and phytohemagglutinin (PHA), but also the interleukin-2 (IL-2) production by spleen cells activated with Con A. However, Neurotropin did not affect the responsiveness of Con A-activated spleen cells to exogenous recombinant IL-2. An absence of suppressor cells capable of inhibiting the IL-2 production in the spleens was confirmed in the 16 mo mice. Neurotropin administration also restored IL-1 production by peritoneal macrophages stimulated with lipopolysaccharide (LPS). These results suggest that long-term administration of Neurotropin restores the decreasing T-cell-dependent immune responses through the recovery of IL-2 and in part IL-1 production, but not the responsiveness to IL-2 in aging BALB/c mice.

Adjuvants, Immunologic↗

Effects of leptospiral lipopolysaccharide on rabbit platelets.

Leptospiral lipopolysaccharides (LPSs) extracted from Leptospira interrogans serovar copenhageni virulent strain Shibaura, serovar canicola virulent strain Moulton, and serovar hebdomadis strain Hebdomadis, were tested for their ability to induce platelet aggregation and/or lysis in rabbit platelet-rich plasma (PRP). All showed positive reactions with a release of adenosine triphosphate (ATP) and serotonin. The values, however, were different from each other. The ability of leptospiral LPS extracted from serovar copenhageni virulent strain Shibaura (I-LPS) to induce platelet aggregation was the highest of all. After treatment of I-LPS, the platelets developed a ruffled surface with appearance of pseudopodia as observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). I-LPS also showed cytotoxicity for the platelets. Degenerative or lytic changes were recognized in 44.5% of the platelets which were observed 60 min after I-LPS treatment.

Adenosine Triphosphate↗

Measurement of distensibility of blood vessels using cineangiograms.

We developed a new, cineangiographic method to accurately measure the dynamic changes in the internal diameter of human arteries in vivo. Cine films were digitized at a spatial resolution of 4 microns/pixel, using a line image sensor. The vessel edges, with a Gaussian fit to a unilateral profile curve of the vessel, were determined with the aid of a computer program. We measured contrast-filled cylinder vessel models (2 to 7 mm in diameter) and evaluated precision, accuracy and linearity of the diameter measurement. A pulsatile vessel model of about 3.9 mm in internal diameter was used to examine the reliability of our method for detecting arterial wall motion. If the coefficient of variation of the vessel diameter determined cineangiographically was less than 2.2% we considered the cineangiograms sufficiently accurate to determine the internal vessel diameter and evaluate arterial distensibility.

Adult↗

Immunological characteristics of the glycolipid antigen of Leptospira interrogans serovar lai.

The protective antigen (PAg), a glycolipid substance, was extracted from Leptospira interrogans serovar lai strain 017 with a chloroform-methanol-water (1:2:0.8 [vol/vol/vol]) solution and partially purified by silica gel column chromatography. The PAg was not detected by Coomassie brilliant blue staining in sodium dodecyl sulfate-polyacrylamide gel electrophoresis but was observed as a smearlike band, which corresponded to a 24- to 30-kilodalton standard protein, by silver staining. The outer envelope (OE) fraction showed the same band, suggesting that the PAg was one of the chemical components of the OE. The immunogenicity and protective activity of the PAg were compared with those of the OE. The PAg as well as the OE and whole cells was able to induce agglutinating antibody against L. interrogans. Furthermore, the immune sera exhibited opsonic activity against L. interrogans, as observed by measurement of chemical luminescence derived from reactive oxygen. The PAg exhibited protective activity in hamsters challenged with lethal doses of L. interrogans. Therefore, the antigen may be useful as a component vaccine against leptospiral infection.

Agglutination Tests↗

Fc-epsilon-receptor-bearing lymphocytes in patients with clonorchiasis.

Expression of Fc-epsilon-receptors (Fc epsilon R) on peripheral blood lymphocytes was examined in patients with clonorchiasis. Mean serum IgE levels in these patients was 2,518 IU/ml. Fc epsilon R was detected by flow cytometry analysis with monoclonal antibody. The frequency of Fc epsilon R+ lymphocytes and the density of Fc epsilon R on the cells in the patients were similar to those in normal subjects. Most of the Fc epsilon R+ lymphocytes were B cells. The number of Fc epsilon R+ cells decreased after incubation in serum-free medium at 37 degrees C for 3 h. The amount of regulatory molecules of IgE production, IgE binding factor, was not significantly different between the patients and normal subjects. The number of Fc gamma R bearing T or B cells in the patients was also similar to that of normal subjects. These results indicate that the mechanisms of elevated serum IgE in patients with clonorchiasis might be different from other diseases with hyperglobulinemia E.

Adolescent↗

Detection and characterization of IgE-producing cells in patients with clonorchiasis.

The ability of peripheral B cells of patients with Clonorchis sinensis infections to secrete IgE spontaneously was investigated in vitro. The de novo synthesis of IgE was observed in unstimulated B-cell cultures of patients. There was a significant relationship between the serum IgE level and the amount of IgE spontaneously secreted by B cells. Pretreatment of patients' B cells with 10 micrograms/ml of rabbit anti-human IgE resulted in the clear suppression of spontaneous IgE synthesis without affecting the IgG synthesis. Their B cells capable of spontaneously secreting IgE were partially sensitive to irradiation with 1,000 rad. The results obtained suggest that such IgE-forming cells may be responsible for at least part of the persistent IgE formation in patients with helminthic infections as well as in those with atopic disease.

Animals↗

Photodynamic activities of food additive dyes on the yeast Saccharomyces cerevisiae.

Photodynamic cell-inactivating activities of food additive dyes on the yeast Saccharomyces cerevisiae were investigated. Activities of dyes not permitted as food additives were also examined. Red No. 105 (rose bengal), Red No. 3 (erythrosine) and Red No. 104 (phloxine), which are permitted as food additives, markedly inactivated yeast cells by photodynamic action. Eosine, matius yellow and guinia green B, which are not permitted, also exhibited moderate cell-inactivating activity by photodynamic action. None of the dyes used in this experiment exhibited petite induction by photodynamic action.

Food Coloring Agents↗

Biological activities of chemically synthesized derivatives of lipid A: tetraacetyl-monosaccharides linked to 2,3-acyloxyacylglucosamine-4-phosphate.

The mitogenicity and lethal toxicity of chemically synthesized lipid A analogs, in which 2,3-acyloxyacylglucosamine-4-phosphate (acyl-GlcN-4P) is linked to a tetraacetyl (Ac4)-monosaccharide, i.e., Ac4-glucose (A-211), Ac4-mannose (A-212), Ac4-galactose (A-213) or Ac4-glucosamine (A-214), were compared with those of tetraacetyl-3-deoxy-D-manno-2-octulosonic acid (Ac4-KDO) linked to acyl-GlcN-4P (A-203). All the compounds were capable of increasing incorporation of 3H-thymidine into splenocytes of C57BL/6 mice at doses of 50 and 100 micrograms/ml, but the mitogenic activity of A-203 at these doses seems to be stronger than those of the analogs. Intravenous injection of A-203, A-211, and A-213 did not exhibit lethal toxicity even at a high dose (50 micrograms/mouse) in C57BL/6 mice loaded with D-galactosamine hydrochloride. However, A-212 and A-214 showed lethality at the doses of 10 and 50 micrograms/mouse, respectively. The findings indicate that the biological activity of these compounds is affected by the kind of monosaccharide linked to acyl-GlcN-4P.

Animals↗

Mutagenicity tests with a permeable mutant of yeast on carcinogens showing false-negative in Salmonella assay.

The mutagenicity (Trp+ reversion) of procarcinogens such as N-nitrosodimethylamine, 3,4-benzpyrene and 2-acetylaminofluorene has been detected with the permeable mutant of yeast, Saccharomyces cerevisiae C658-K42. The original strain C658, however, showed a positive response only to N-nitrosodimethylamine with S9 mix. The permeable mutant C658-K42 was employed for mutagenicity tests on 12 carcinogens which had been reported to be non-mutagenic in Salmonella/microsome tests. It was found that phenobarbital, thiourea, 1,2-dimethylhydrazine and 4-aminoantipyrine were mutagenic in the presence of S9 mix. Benzene, o-toluidine and thioacetamide were weakly mutagenic. Negative results were obtained for diethylstilbestrol, safrole, acetamide, urethane and ethionine at the concentrations used. Caprolactam did not show any mutagenic effect on C658-K42 at concentrations up to 20 mg/ml. Sodium azide, which is unlikely to be carcinogenic but is strongly mutagenic in the Ames test, showed a very weak mutagenic effect on C658-K42.

Animals↗

Monoclonal antibody against Leptospira interrogans serovar canicola.

Nine cell lines producing monoclonal antibodies (MAbs) against Leptospira interrogans serovar canicola strain Moulton were established by the cell fusion technique. The immunological reactivity of these MAbs with various kinds of serogroups, serovars and strains were examined by microscopic agglutination test (MAT) and enzyme-linked immunosorbent assay (ELISA). MAbs W1-W3 derived from mice, which were immunized with whole cells of the strain Moulton, reacted with the serogroups Canicola, Icterohaemorrhagiae and Pyrogenes. On the other hand, MAbs A1-A6 derived from mice immunized with the outer envelope (OE) fraction, which showed a potent protective activity and was extracted with ammonium hydroxide from the strain Moulton, reacted specifically with the serogroup Canicola alone in MAT. A difference in antigenic structure between subserogroup A (canicola subgroup) and subserogroups B (schüeffneri subgroup) of the serogroup Canicola was demonstrated by MAT using the MAbs. All the MAbs clearly agglutinated serovars of subserogroup A except for serovars kamituga, jonsis and bindjei, but did not react with any serovars of subserogroup B. These findings suggest that MAb highly specific to each serovar is readily available by OE immunization and is useful for the classification of Leptospira.

Animals↗

Immunopharmacological studies on TBX, a new antiallergic drug (3). Inhibitory effects on histamine release from lung fragments and bronchoconstriction in guinea pigs.

The effects of 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one potassium salt (TBX), a new antiallergic drug, on histamine release from lung fragments, experimental asthma and isolated tracheal muscle were investigated in guinea pigs. TBX (10(-7) to 10(-4) g/ml) dose-dependently inhibited antigen-induced histamine release from lung fragments of guinea pigs passively sensitized with homologous IgE serum. Antigen inhalation-induced experimental asthma in passively sensitized animals was inhibited in a dose-dependent fashion by i.v. (1 to 5 mg/kg) and p.o. (10 to 100 mg/kg) administrations of TBX. In vivo bronchoconstriction by platelet-activating factor (PAF, i.v.) was also inhibited by TBX (0.3 to 10 mg/kg, i.v.). However, high concentrations of TBX (more than 3 x 10(-4) g/ml) were needed to inhibit PAF-induced platelet aggregation in vitro. With regard to the effect on isolated tracheal muscle, TBX itself at concentrations higher than 10(-5) g/ml induced dose-dependent reduction in the resting tonus, which was not affected by pretreatment with propranolol. Neither the leukotriene D4-induced contraction nor the prostaglandin F2 alpha-induced one was specifically antagonized by TBX. The results obtained indicate that TBX is an antiasthmatic agent effective in inhibiting both IgE- and PAF-induced bronchoconstriction, possibly by interfering with mediator release.

Animals↗

Immunopharmacological studies on TBX, a new antiallergic drug (4). Effects on type II to IV allergic reactions and immunological functions in animal models.

The effects of 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one potassium salt (TBX) on type II to IV allergic reactions and immunological functions were investigated in animal models. Types II to IV allergic reactions in rodents were unaffected in vivo by TBX, even at higher doses than those capable of completely inhibiting the type I allergic reaction. However, both complement-mediated hemolysis via the classical pathway and hypotonic shock-induced hemolysis were slightly inhibited in vitro only by a high concentration of the drug (10(-4) g/ml). In the mouse system, TBX had no ability to suppress anti-hapten IgE antibody formation as well as hemagglutinin formation and to inhibit the proliferation of spleen cells induced by non-specific T and B cell mitogens. The results obtained indicate that TBX is an antiallergic drug essentially devoid of inhibitory actions on types II to IV allergic reactions and immunological functions, thus indicating that it is a specific inhibitor of type I allergic reactions.

Animals↗

Separation of peptides by multimode chromatography on a column packed with vinyl alcohol copolymer gel.

Several mechanisms of peptide separation in high-performance liquid chromatography were observed to occur on the Asahipak GS-320 packed with vinyl alcohol copolymer. Neutral rather than acidic mobile phases were employed as they were found to result in higher retention of many peptides on the GS-320. For neutral peptides, the retention volume corresponded to the Rekker's hydrophobic fragmental constant, with a correlation coefficient of 0.71. Peptides with acidic residues eluted early, as an effect of ionic exclusion; those with basic residues were retained longer, owing to an ion-exchange effect. The ionic interactions were shown to involve the carboxylic group present on the gel polymer. The net result was found to be excellent separation of hydrophilic as well as hydrophobic peptides, related to differences in their isoelectric points. The combination of these complex mechanisms, together with the size-exclusion effect of the GS-320 gel for separation of proteins and other large molecules and for analysis with a mobile phase high in acetonitrile content, makes possible high-resolution isocratic analysis of peptides, which cannot be achieved on octadecylsilica or ion-exchange columns.

Amino Acid Sequence↗

Determination of salsolinol by ion-exchange chromatography with glycylglycine as the post-derivatizing agent.

The determination of salsolinol in human urine was carried out by ion-exchange chromatography on two coupled columns of a weakly acidic ion exchanger with a hydrophilic matrix (Asahipak ES-502C). Salsolinol was first isolated from urine by adsorption on Amberlite CG-50. It was eluted together with catecholamines by 2/3 M boric acid solution. The amines were then separated by isocratic elution from the first column of Asahipak with 0.05 M sodium succinate buffer (pH 5.5) containing 0.015 M borate and 0.5 mM ethylenediaminetetraacetate. Epinephrine, norepinephrine, dopamine and salsolinol were eluted in that order. The salsolinol-containing fraction was then transferred, by column switching, to a second Asahipak column and eluted with the same mobile phase. Salsolinol was determined fluorimetrically by reaction with glycylglycine in the presence of hexacyanoferrate(III) at pH 7.5-8 and 65 degrees C. Samples could be analysed every 47 min. The detection limit for salsolinol was 2 pmol/ml.

Chromatography, Ion Exchange↗

Biological activities of chemically synthesized N-acetylneuraminic acid-(alpha 2----6)-monosaccharide analogs of lipid A.

The mitogenicity and lethal toxicity of chemically synthesized lipid A analogs, in which 2,3-acyloxyacylglucosamine-4-phosphate linked to tetraacetyl-N-acetylneuraminic acid (compound A-207) or to N-acetylneuraminic acid (compound A-307), were examined. Although the mitogenic activity of the synthetic compounds was weaker than that of bacterial LPS, doses of 10-50 micrograms/ml of A-207 and 5-10 micrograms/ml of A-307 were capable of increasing incorporation of [3H]thymidine into cultured spleen cells of C57BL/6 mice. Lethal toxicity of A-207 was observed at 10 micrograms/mouse in C57BL/6 mice sensitized with D-galactosamine hydrochloride. However, the attachment of tetraacetyl-N-acetylneuraminic acid or N-acetylneuraminic acid does not appear to enhance the biological activity of acyloxyacylglucosamine-4-phosphate.

Animals↗

Classification of Leptospira interrogans serovar lai strain 017 by using monoclonal antibodies.

Leptospira interrogans serovar lai was identified in China in 1966 as a new serovar of the icterohaemorrhagiae serogroup by cross-absorption tests. In this study, we established three hybridoma cell lines producing monoclonal antibodies (MAbs) of the immunoglobulin G3 subclass (LW1, LW2, and LW3) and of the immunoglobulin M class (LW4a) against serovar lai strain 017 by the cell fusion technique. Immunological reactivities of the MAbs were determined by the microscopic agglutination test, enzyme-linked immunosorbent assay (ELISA), and indirect immunofluorescence assay. MAbs LW1 and LW3 agglutinated cells of serovars lai, birkini, and gem of serogroup icterohaemorrhagiae. LW2 agglutinated various serovars of serogroup icterohaemorrhagiae, except for serovar tonkini. LW4a reacted positively with various Leptospira species, including a new species, Leptospira parva, in the ELISA and indirect immunofluorescence assay. However, LW4a did not react with Leptonema illini 3055. The results of an inhibition ELISA with heated outer envelope (OE) or periodate-oxidized OE suggested that these MAbs recognize a carbohydrate moiety of the OE as the antigenic determinant.

Antibodies, Monoclonal↗