Biomedical subjects

Y Mimura

Publications and source records attributed to Y Mimura.

At least 127 records · Page 7Linked to original sources

PubMed1994

[Localization of bovine corneal protein 54K (BCP 54) in the prenatal mouse eye].

Localization of bovine corneal protein 54K (BCP54) in the prenatal mouse eye was examined by immunohistochemical methods using rat anti-BCP54 polyclonal antibody. BCP54 was found from an early prenatal stage in corneal epithelium, keratocytes, corneal endothelium, conjunctival epithelium, and surface ectoderm which would differentiate in other organs except the eye. In other reports, it has been ascertained that BCP54 has an aldehyde dehydrogenase activity. To take its enzyme activity into consideration, we suggest that BCP54 is involved in maintaining transparency and oxidation-reduction balance of the cornea.

Aldehyde Dehydrogenase↗

PubMed1994

[Reducing cross-talk in electrooculograms made with several electrodes].

In order to discuss how to handle the contralateral effect (cross-talk) when taking an electrooculogram (EOG) with two or more electrodes, a forced duction test was used to detect cross-talk potentials. The cross-talk potentials originating from the left eye were measured at the right eye for 5 subjects when the left eye was adducted and abducted alternately with a suction contact lens while the right eye was kept fixed. The cross-talk potentials detected at the right eye did not depend on the electrode position, but the contralateral EOG potentials depended on the electrode position around the left eye. The cross-talk value is calculated as the gain, 20.log [(cross-talk potential)/(contralateral EOG potential)]. The denominator of this expression considerably affects the gain since the contralateral potential depends on the position of the electrode. We propose that the effect of the cross-talk on the potential between a pair of electrodes can be cancelled with the gain value (-15.0dB: the mean value for the 5 subjects) when the contralateral electrode is set 20 mm from the outer canthus.

Electrodes↗

PubMed1993

Decreased messenger RNA of arachidonate 12-lipoxygenase in platelets of patients with myeloproliferative disorders.

On the basis of the previous work by Okuma and Uchino [Blood 54, 1258-1271, 1979], three patients with myeloproliferative disorders were investigated with a special reference to arachidonate 12-lipoxygenase in their platelets. The cytosol of the patients' platelets showed a markedly reduced activity of arachidonic acid oxygenation to 12-hydroperoxy acid. A peroxidase-linked immunoassay for the 12-lipoxygenase demonstrated only 7-12% of the normal level of the enzyme protein in the cytosol fraction of platelets. Furthermore, 12-lipoxygenase mRNA level was determined quantitatively by a reverse transcriptase-polymerase chain reaction with an internal standard cRNA which was synthesized by in vitro transcription of human platelet 12-lipoxygenase cDNA with a 105-bp deletion. The 12-lipoxygenase mRNA content was 4.7 +/- 2.0 (mean +/- S.D.) ng/10(11) platelets in 13 normal subjects. In contrast, the mRNA content was as low as 0.15, 0.11 and 0.10 ng/10(11) platelets in the three patients. Taken together, the 12-lipoxygenase deficiency in these patients was attributable to the decreased 12-lipoxygenase mRNA level and thus the impaired synthesis of the enzyme protein in their platelets.

Antibodies, Monoclonal↗

PubMed1993

Degradation of fibrinogen and fibrin by plasmin and nonplasmin proteases in the chronic subdural hematoma: evaluation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot.

To characterize local hyperfibrinolysis in the pathogenesis of chronic subdural hematoma (CSDH), fibrin degradation products (FDPs) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to identify each FDP fragment (fragments HMW, YY, DY and DD) by immunoblotting. The electrophoretic patterns of FDP in 40 hematomas from 33 patients could be categorized into 3 patterns; (i) type 1, the sharp DY and DD bands; (ii) type 2, the broad DY and DD bands; and (iii) type 3, the sharp DY and DD with two bands with higher molecular weights than fragment DY and DD. The broadening of DY and DD bands was reproduced by incubating the sample containing sharp DD and DY bands with the hemolyzed peripheral blood cells. These results indicated that the hyperfibrinolysis in CSDH could be characterized by the constant and incomplete proteolysis of fibrinogen and fibrin by plasmin and further degradation of FDPs by non-plasmin proteases released from hemolyzed blood cells.

Electrophoresis, Polyacrylamide Gel↗

PubMed1993

Affinity maturation of anti-hapten antibodies in a single mouse analyzed by two-dimensional affinity electrophoresis.

Affinity maturation of anti-hapten antibodies in an inbred mouse (BALB/c) was analyzed by two-dimensional affinity electrophoresis (2D-AEP) in which the antibodies specific to a hapten of dinitrophenyl (DNP) group were separated into a large number of IgG families according to the differences in their isoelectric points (pI) and in their affinities for the ligand of DNP immobilized in the gel matrices. Each of the IgG families consisted of several spots showing an identical affinity for the ligand but different pI, and the spots were specifically stained by immunostaining with an anti-murine IgG subclass antibody. These results lead us to the conclusion that each of the IgG families is derived from a single clone of antibody-producing cells specific to DNP. The mass and affinity of the IgG families varied in the course of immunization with DNP-conjugated chicken serum albumin (DNP-CSA). The first injection of DNP-CSA induced a small amount of IgG families showing a wide variety in their affinity for DNP. The second injection induced a large amount of IgG families, especially of families having a medium affinity for DNP. Additional injections, however, did not change the mass or affinity of the IgG families significantly. This suggests that an antigen-induced somatic mutation of the immunoglobulin gene does not occur frequently to mature the affinity of antibodies by the additional injections after the second injection. 2D-AEP enables us to analyze the affinity maturation of antibodies in vivo in a single mouse and to document the subclass switch of the antibody in the course of immunization.

Animals↗

PubMed1993

Treatment of cerebrotendinous xanthomatosis with low-density lipoprotein (LDL)-apheresis.

We studied the effects of LDL-apheresis on the biochemical and clinical abnormalities of 5 patients with cerebrotendinous xanthomatosis (CTX). Levels of both cholestanol and cholesterol decreased to approximately 60% of those of pretreatment after one perfusion and gradually returned to their initial levels within 2 weeks. Improvement of clinical manifestations and regression of Achilles tendon xanthomas were detected after several perfusions, though dramatic changes could not be recognized. EEG abnormalities were improved immediately after LDL-apheresis in one patient. We conclude that LDL-apheresis may affect the serum cholestanol level and clinical manifestations in patients with CTX.

Achilles Tendon↗

PubMed1993

Chemical structure-activity of cnidium rhizome-derived phthalides for the competence inhibition of proliferation in primary cultures of mouse aorta smooth muscle cells.

Inhibitory effects of cnidium rhizome-derived phthalides on competence and progression phases of fetal bovine serum (10%)-induced proliferation were compared in primary cultures of mouse aorta smooth muscle cells (SMC). Their potencies for the competence inhibition were in the order of senkyunolide L ((Z)-6-hydroxy-7-chloro-6,7-dihydroligustilide) > senkyunolide H ((Z)-6,7-dihydroxy-6,7-dihydroligustilide) > senkyunolide J ((3S)-(E)-6,7-dihydroxy-3,6,7,8-tetrahydroligustilide) > senkyunolide I ((E)-6,7-dihydroxy-6,7-dihydroligustilide) > ligustilide = senkyunolide A ((3S)-3,8-dihydroligustilide) > butylidenephthalide. The order of their potencies for the progression inhibition was parallel with that for the competence inhibition. Senkyunolide L is considered to have been formed during the extraction of cnidium. These results demonstrate that the (Z)-6,7-dihydroxy isomer of the dihydroligustilide derivatives is essential for the anti-competent effect on proliferation of the SMC in primary culture. Senkyunolide H in cnidium rhizome may be a prototype for a new anti-atherosclerotic drug.

4-Butyrolactone↗

PubMed1993

AB5046A and B, novel chlorosis-inducing substances from Nodulisporium sp.

Novel chlorosis-inducing substances, AB5046A and B, were isolated from the culture broth of a fungal strain. The producing organism, designated AB5046, was identified as a member of Nodulisporium. AB5046A and B were purified by extraction with EtOAc and silica gel chromatography. The structure of AB5046A and B were determined to be 2-butyryl-3,5-dihydroxy-cyclohex-2-ene-1-one and 2-acetyl-3,5-dihydroxy-cyclohex-2-ene-1-one, respectively, by spectroscopic analyses. AB5046A and B induced chlorosis against Japanese barnyard millet in vitro. The chlorosis activity of these compounds was stronger against monocotyledons than dicotyledons.

Animals↗

PubMed1993

Erythropoietin production in hepatocellular carcinoma cells associated with polycythemia: immunohistochemical evidence.

Patients with hepatocellular carcinoma sometimes have erythrocytosis and high plasma erythropoietin levels. However, previous studies have not revealed direct evidence that the carcinoma cells produce the erythropoietin. To address this question, we carried out light and electron microscopic immunohistochemical studies, using a human erythropoietin antibody to the liver in three male patients with hepatocellular carcinoma and erythrocytosis. alpha-Feto-protein localization was also examined in serial liver sections by light microscopic immunohistochemistry with an antibody to alpha-fetoprotein. All three patients demonstrated high hemoglobin levels (16.7, 17.6 and 18.1 gm/dl) and high plasma erythropoietin levels (227, 266 and 280 mU/ml). In one patient the plasma erythropoietin level in the hepatic vein was significantly higher than that in the hepatic artery. The levels of plasma erythropoietin, as well as such tumor markers for hepatocellular carcinoma as serum alpha-fetoprotein and plasma des-gamma-carboxyprothrombin, were significantly reduced after treatment with an anticancer drug, cisplatin. Light microscopic immunohistochemistry showed that erythropoietin was definitely present in the cytoplasm of the hepatocellular carcinoma cells, but not in normal hepatocytes around the carcinoma lesion or in other nonparenchymal cells such as vascular endothelial cells and Kupffer cells. In electron microscopic immunohistochemistry, reaction products for erythropoietin were revealed in the cisternae of the endoplasmic reticulum in the carcinoma cells, suggesting the production of erythropoietin by these cells. Light microscopic immunohistochemistry showed that alpha-fetoprotein was localized in the hepatocellular carcinoma cells that were erythropoietin positive in the serial sections. These findings indicated that hepatocellular carcinoma cells produced erythropoietin as well as alpha-fetoprotein in these cases, leading to the complication of erythrocytosis.

Aged↗

PubMed1992

Analysis of the interaction between an alpha (1----6)dextran-specific mouse hybridoma antibody and dextran B512 by affinity electrophoresis.

Carbohydrates are common environmental antigens. As dextran B512 is composed of a repeating structure of simple antigenic determinants, it is widely used to study the immunochemical properties of immunoglobulins. Two-dimensional affinity electrophoresis patterns of a mouse monoclonal antidextran antibody (35.8.2H; IgG1, BALB/c) were produced to obtain insights into the microheterogeneity of the monoclonal antibody. The monoclonal antibody was separated into about six spots which had an identical affinity to dextran B512, but differed in their isoelectric points (pI). In addition, the pH dependence of the binding affinity of this antidextran to dextran B512 was examined. By comparing affinities obtained by affinity electrophoresis between weakly basic (pH 9.5) and weakly acidic (pH 3.8) discontinuous buffer systems, the latter showed an affinity about 500 times lower than the former. The change in the affinity was investigated with a continuous pH gradient by an affinity titration curve and was seen to change markedly at about pH 6. This suggests that the histidine at residue 34 in the light-chain CDR1 is largely responsible for the dextran binding.

Amino Acid Sequence↗

PubMed1992

Kinetic properties of the bovine corneal aldehyde dehydrogenase (BCP 54).

The major soluble protein of bovine cornea (BCP 54: bovine corneal protein 54 kDa) was isolated successively by gel filtration, anion-exchange chromatography and chromatofocusing. The amino acid sequence of a fragment of the purified BCP 54 obtained by lysyl-endopeptidase digestion showed marked homology with tumor-associated and 2,3,7,8-tetrachloro-dibenzo-p-dioxin-inducible aldehyde dehydrogenase (AIDH). From the high similarity of BCP 54 with tumor-associated AIDH in structural form, it is suggested that BCP 54 has AIDH activity. We confirmed a high AIDH activity of BCP 54 by immunoprecipitation using a mouse anti-BCP 54 monoclonal antibody followed by a spectrophotometric assay for AIDH activity. Next we demonstrated the unique properties of the purified BCP 54 as AIDH. The major isoelectric point is 6.41. BCP 54 preferentially oxidizes aromatic aldehyde such as benzaldehyde with NAD as coenzyme, but cannot oxidize phenylacetaldehyde. After heat treatment the AIDH activity is more stable with propionaldehyde-NAD than with benzaldehyde-NADP. With propionaldehyde-NAD the pH profile shows a broad plateau from pH 6-9 followed by a sharp rise up to pH 10. In contrast, with benzaldehyde-NADP there is a sharp optimum at pH 9.0. The activity with only benzaldehyde-NADP is inhibited by p-hydroxymercuribenzoate, but is not affected by disulfiram and diethylstilbestrol. So we suggested that BCP 54 is an AIDH with kinetic properties different from the rat tumor-associated AIDH.

Aldehyde Dehydrogenase↗

PubMed1992

N.m.r. study of interaction between sugar and peptide moieties in mucin-type model glycopeptides.

In order to investigate the structural properties of the sugar and peptide linkage region in glycoprotein, some glycopeptides were synthesized as a model for AFGP (antifreeze glycoprotein), which is one of the mucin-type glycoproteins. The results from n.m.r. measurements in DMSO and aqueous conditions revealed that the glycopeptides form an intramolecular hydrogen bond between the amide proton of N-acetylgalactosamine (GalNAc) and the carbonyl oxygen of threonine (Thr) to which the GalNAc is covalently linked. This intramolecular hydrogen bond may play an important role in determining the orientation of the sugar moiety relative to the protein backbone. The roles for the activity of the proline (Pro) residue in AFGP were also discussed.

Amino Acid Sequence↗

PubMed1992

Antiproliferative effects of the traditional Chinese medicine shimotsu-to, its component cnidium rhizome and derived compounds on primary cultures of mouse aorta smooth muscle cells.

Antiproliferative effects of the Japanese-Sino medicine Shimotsu-to (a combined prescription of cnidium rhizome, angelica root, peony root and rehmannia root) were investigated in the primary culture of smooth muscle cells (SMC) of mouse aorta. Fetal bovine serum (10%)-induced proliferation of primary cultured SMC was inhibited by Shimotsu-to at 4, 20, 100 or 500 micrograms/ml. The inhibitory effect was selective on SMC and due to cnidium rhizome or angelica root. The IC50 values of senkyunolide H, senkyunolide A, ligustilide and butylidenephthalide derived from cnidium were below 0.1, 1.52, 1.68 and 3.25 micrograms/ml, respectively. These results indicate that the antiproliferative effect of Shimotsu-to may depend on these cnidium-derived phthalides.

Animals↗

PubMed1992

AB3217-A, a novel anti-mite substance produced by a strain of Streptomyces platensis.

AB3217-A, a novel anti-mite substance, was isolated from the fermentation broth of a streptomycete strain. The strain was isolated from a soil collected at Kita-azumi, Nagano Prefecture, Japan, and identified as Streptomyces platensis AB3217. AB3217-A was purified by Amberlite IR120B, Diaion HP-20 and CM-Sephadex C-25 column chromatographies. The molecular formula was determined as C17H23NO7 by elemental analysis, MS and 13C NMR spectroscopy. The structure of AB3217-A was determined to be (1R,3S,4S,7R,8R,11R,12S,13R)-4,12,13-trihydroxy-8-(4-methoxy phenyl)-6-aza-2,9,14-trioxatricyclo-[9.2.1.0(3,7)]tetradecane by spectroscopic analysis and X-ray crystallographic analysis. The molecule of AB3217-A has unique structure that deacetylanisomycin and beta-D-xylofuranose linked through glycosidic bond and ether bond resulting in the formation of nine-membered ring. AB3217-A showed marked activity against the two spotted spider mite, Tetranychus urticae.

Animals↗

PubMed1992

[Adult-onset neuronal ceroid lipofuscinosis--a case report with biological study].

A 32-year-old male was admitted to our hospital complaining of dementia, gait disturbance and blindness. These symptoms developed at the early two decade and were progressive. On admission, his clinical features included dementia (IQ = 69), spasticity, accentuated deep tendon reflexes, ataxia and hypesthesias in his distal limbs. Brain CT scans showed diffuse cerebral atrophy. On light microscopy, many abnormal lipopigments resembling ceroid and lipofuscin were found in Schwann cells of sural nerve and histiocytes of colon. Ultrastructurally, these materials showed lamellar structure like Zebra bodies. Nine lysosomal enzymes, serum very long-chain fatty acids, serum amino acids and urinary oligosaccharides were all normal. Neuronal ceroid lipofuscinosis (NCL) of adult type was diagnosed on the basis of clinical features, radiological and pathological findings, and biochemical studies. Many previous studies suggested that NCL was a disorder with lysosomal dysfunction. We examined lysosomal protein degradation, using 125I-low density lipoprotein (LDL) in cultured fibroblasts from this patient. The degradation of LDL was normal, compared to control subjects. The activities of cathepsin and lysosomal glycosidases, were also normal. The amount of urinary dolichol has been reported to be elevated in the patients with infantile and late infantile types of NCL. However, no elevation was found in the urine of our patient.

Adult↗

PubMed1992

Endotoxin-induced uveitis in mice. 1. Induction of uveitis and role of T lymphocytes.

Endotoxin-induced uveitis (EIU) with a high frequency of posterior iris synechiae was induced by the systemic injection of 200 micrograms of endotoxin into C3H/HeN mice, an endotoxin-responsive strain. The cell number and the protein concentration within the aqueous humor began to increase 6 hours after the injection, achieving a peak at 24 hours, and decreased gradually thereafter. Inflammatory cells were observed in the anterior chamber, the vitreous body and near the iris-ciliary body histologically. Most of the inflammatory cells were polymorphonuclear cells. On the other hand, C3H/HeJ mice, an endotoxin-unresponsive strain, showed no increase in either cell number or protein concentration in the aqueous humor after endotoxin administration. Pretreatment of C3H/HeN mice with anti-Thy-1.2 antibody significantly decreased both the cell number and the protein concentration in the aqueous humor and the incidence of the posterior synechiae, as compared with the control group. Anti-CD4 antibody also significantly reduced the severity of EIU, while anti-CD8 antibody had no influence on the disease. Anti-IFN-gamma antibody increased the cell number in the aqueous humor. These observations indicate that T lymphocytes, especially CD4+ T lymphocytes, have an extremely important role in the development of EIU in mice.

Animals↗

PubMed1992

[Diagnosis and management of benign biliary strictures with percutaneous transhepatic cholangioscopy (PTCS)].

From January 1981 through March 1991, we encountered twenty four cases of benign biliary strictures. In 10 cases of anastomotic stricture, percutaneous dilatation was carried out in 1 patient under fluoroscopy and in 3 patients under PTCS without recurrence. Endoprosthesis with silicone or polyurethane catheters was carried out under PTCS in 5 patients. One of them died of hepatic failure due to clogging of the catheter, and in other four patients the endoprosthetic catheter was dislodged spontaneously or removed by PTCS because of dislodgement or obstruction of the catheter, and PTCS revealed that the anastomotic stricture had improved. Reoperation of cholangiojejunostomy was carried out in 1 patient, who died of hepatic failure 5 years later due to recurrent of stricture. In 8 cases of the iatrogenic and 1 case of traumatic stricture, percutaneous dilatation was carried out (1 under fluoroscopy and 4 under PTCS) without recurrence. Cholangiojejunostomy was carried out in 3 cases without anastomotic stricture. PTCS was performed for 5 cases of the inflammatory stricture of the hepatic hilus due to cholecystitis to confirm the histological findings by cholangioscopic biopsy. And all cases could be managed by cholecystectomy. Authors recommend that PTCS should be used for the diagnosis and treatment of benign biliary stricture.

Aged↗

PubMed1992

Characterization of T-cell subsets, soluble interleukin-2 receptors and interleukin-6 in Vogt-Koyanagi-Harada disease.

The lymphocyte subunits and subsets of 12 patients with Vogt-Koyanagi-Harada disease (VKH disease) were characterized using two-color flow cytometry techniques, both in cerebrospinal fluid (CSF) and in peripheral blood (PB). Soluble interleukin-2 receptor (sIL-2R) levels and interleukin-6 (IL-6) levels were also measured. The percentage of T cells was significantly higher in CSF than in PB (P less than 0.01), but the percentage of B cells was decreased in CSF (P less than 0.05). As for T-cell subsets, the percentage of helper T cells was especially high in CSF (P less than 0.01). Also, the ratio of helper T cells/suppressor T cells was significantly larger in CSF than in PB. These data suggest that helper T cells play an important role in the early stages of VKH disease. sIL-2R and IL-6 levels were not elevated in CSF of patients with VKH disease. The level of sIL-2R in serum also was not elevated.

Adult↗