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Biomedical subjects

T Kuramoto

Publications and source records attributed to T Kuramoto.

At least 55 records · Page 3Linked to original sources
PubMed1997

Bile acid profiles in a peroxisomal D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein deficiency.

Bile acid profiles in serum, urine and bile from an infant with a peroxisomal D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (D-bifunctional protein) deficiency were analyzed by means of gas-liquid chromatography, gas-liquid chromatography-mass spectrometry, and high-performance liquid chromatography. As in such several peroxisomal disorders as Zellweger syndrome, neonatal adrenoleukodystrophy, and infantile Refsum disease, the accumulation of C27-bile acid intermediates was also demonstrated in the infant with D-bifunctional protein deficiency, accounting for 74% of the total bile acids in serum, 59% in urine, and 35% in bile. In addition, the major constituents of the C27-bile acids were (24R,25R)- and (24R,25S)-3alpha,7alpha,12alpha,24-tetrahydroxy-5be ta-cholestanoic acids along with small amounts of their 24S counterparts. Since immunoreactive acyl-CoA oxidase, L-bifunctional protein, and thiolase were all present in the liver, the impairment of the oxidative side-chain cleavage in bile acid biosynthesis is considered to be due to the defect of D-bifunctional protein.

17-Hydroxysteroid Dehydrogenases↗
PubMed1997

Detection of MAGE-1 tumor antigen in brain tumor.

The expression of MAGE tumor rejection antigens in brain tumors is unclear. We investigated the expression of MAGE-1 and -4 proteins in brain tumors with antibodies to recombinant MAGE-1 and -4 proteins. MAGE-1 or -4 protein was detected in a majority (12 of 14) or some (5 of 14) of gliomas, respectively, by the immunoblot analysis. In contrast, MAGE-1 or -4 protein was rarely detected in the non-glioma tumors (3 of 14 or 1 of 14, respectively). Cellular MAGE-1 protein was detected in the cytoplasma of the glioblastoma cells with immunohistochemical staining. The expression of the MAGE-4 protein was confirmed by enzyme-linked immunosorbent assay. The results suggest that the MAGE-1 protein is an appropriate target molecule for specific immunotherapy of glioma.

Antigens, Neoplasm↗
PubMed1997

Significance of urinary type IV collagen in patients with diabetic nephropathy using a highly sensitive one-step sandwich enzyme immunoassay.

Urinary concentrations of type IV collagen in patients with diabetic nephropathy were measured by a highly sensitive, one-step sandwich enzyme immunoassay. Samples from 298 patients with noninsulin-dependent diabetes mellitus (NIDDM) and 80 healthy controls were examined. In diabetic patients with macroalbuminuria or renal insufficiency, the concentrations of urinary type IV collagen were significantly higher than those of diabetic patients with normoalbuminuria or healthy controls (P < 0.001). Urinary type IV collagen concentration in diabetic patients with microalbuminuria was significantly higher than that in diabetic patients with normoalbuminuria or that in healthy controls (P < 0.001). In contrast, there were no significant changes in the concentration of serum type IV collagen between microalbuminuric patients and normoalbuminuric patients. The area under the receiver operating characteristic (ROC) curve for the urinary type IV collagen concentration was equivalent to that of urinary albumin. It was concluded that urinary type IV collagen concentration determined using this method might be a useful marker for the early detection of diabetic nephropathy.

Adult↗
PubMed1996

A rat genetic map constructed by representational difference analysis markers with suitability for large-scale typing.

Representational difference analysis (RDA) was applied to isolate chromosomal markers in the rat. Four series of RDA [restriction enzymes, BamHI and HindIII; subtraction of ACI/N (ACI) amplicon from BUF/Nac (BUF) amplicon and vice versa] yielded 131 polymorphic markers; 125 of these markers were mapped to all chromosomes except for chromosome X. This was done by using a mapping panel of 105 ACI x BUF F2 rats. To complement the relative paucity of chromosomal markers in the rat, genetically directed RDA, which allows isolation of polymorphic markers in the specific chromosomal region, was performed. By changing the F2 driver-DNA allele frequency around the region, four markers were isolated from the D1Ncc1 locus. Twenty-five of 27 RDA markers were informative regarding the dot blot analysis of amplicons, hybridizing only with tester amplicons. Dot blot analysis at a high density per unit of area made it possible to process a large number of samples. Quantitative trait loci can now be mapped in the rat genome by processing a large number of samples with RDA markers and then by isolating markers close to the loci of interest by genetically directed RDA.

Alleles↗
PubMed1996

Measurement of soluble thrombomodulin in sera from various clinical stages of diabetic nephropathy.

The levels of soluble thrombomodulin (TM) in serum samples were measured by one-step sandwich enzyme immunoassay. The aim of the present study was to determine if levels of soluble TM in sera might correlate with disease activity in patients with diabetic nephropathy. Three hundred and twenty patients with diabetic nephropathy were examined. Patients with diabetic retinopathy were excluded from the present study. This study showed an increase of soluble TM levels in sera from patients with diabetic nephropathy. The levels of soluble TM in sera from the macroalbuminuric stage with renal dysfunction were significantly increased compared with those from the normo-, micro-, or macroalbuminuric stage of diabetic nephropathy without renal dysfunction. The increase of soluble TM in sera paralleled levels of urinary albumin, blood urea nitrogen (BUN), s-creatinine (Cr), and duration of noninsulin-dependent diabetes mellitus (NIDDM). Furthermore, a decrease of TM staining in the glomerular capillary walls was observed in both microalbuminuric and macroalbuminuric stages by immunofluorescence. It appears that the measurement of soluble TM in sera is useful in evaluating the degree of glomerular endothelial injuries in patients with diabetic nephropathy.

Blood Urea Nitrogen↗
PubMed1996

A rat mutation producing demyelination (dmy) maps to chromosome 17.

A recessive mutation exhibiting severe myelin breakdown, mainly at the level of the lumbar segments of the spinal cord and without any associated inflammation, was discovered in a partially inbred rat colony. Analysis of the segregation patterns of a set of polymorphic microsatellite markers in two inter-strain crosses allowed the mapping of this autosomal recessive mutation to rat Chromosome (Chr) 17, very close to the prolactin (Prl) locus, in a region homologous to human Chr 6p21.2-22.3 and mouse Chr 13. The pathology of the demyelination process and the chromosomal localization indicate that this mutation has no known equivalent in either mouse or human.

Animals↗
PubMed1996

Comparison of side chain oxidation of potential C27-bile acid intermediates between mitochondria and peroxisomes of the rat liver: presence of beta-oxidation activity for bile acid biosynthesis in mitochondria.

The oxidation of the side chains of two potential bile acid intermediates, 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) and 3 alpha,7 alpha-dihydroxy-5 beta-cholestanoic acid (DHCA), were investigated in rat liver mitochondria and peroxisomes. Both THCA and DHCA were efficiently oxidized to yield cholic acid and chenodeoxycholic acid, along with 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-24-enoic acid and 3 alpha,7 alpha-dihydroxy-5 beta-cholest-24-enoic acid, respectively, in both the mitochondria and peroxisomes. However, the spectrum of the metabolites in the mitochondria differed greatly from those in the peroxisomes. The major products from THCA and DHCA in the mitochondria were 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-chol-22-enoic acid and 3 alpha,7 alpha-trihydroxy-5 beta-chol-22-enoic acid, respectively, which were tentatively identified from the mass spectral data. However, the formation of these C24-unsaturated bile acids was not observed in the peroxisomes. These results strongly suggest that the cleavage of the side chain of the C27-intermediates for bile acid biosynthesis also occurs independently in the mitochondria, not due to the contamination of peroxisomes.

Animals↗
PubMed1995

Establishment of an enzyme-linked immunosorbent assay (ELISA) for measuring cellular MAGE-4 protein on human cancers.

The MAGE genes encoding tumor-rejection antigens are expressed on various human cancers. An enzyme-linked immunosorbent assay (ELISA) was established for measuring cellular MAGE-4 protein (MAGE-4a and/or -4b) expressed on human tumor cells using a monoclonal antibody (mAb) and polyclonal Ab to recombinant MAGE-4b protein. Both the R5 mAb (IgG1) and the polyclonal Ab recognized a 45 kDa protein in extracts of MAGE-4 mRNA positive cancers, and showed no apparent cross-reactivity to the other MAGE gene products (MAGE-1, -2, -3, -6, and -12) by the immunoblot analyses. The R5 mAb and the polyclonal Ab primarily recognized one (the position 119-133) and two oligopeptides (the positions 119-133 and 259-273), respectively, among a series of 31 different MAGE-4b oligopeptides. The amino acid sequences of these two peptides were identical to those of MAGE-4a and -4b, but differed from those of all the other MAGE proteins (MAGE-1, -2, -3, -6, and -12). Substitution of glycine for amino acid in position 123 (arginine, R), 124 (lysine, K), 126 (R) or 128 (K) in a MAGE-4b oligopeptide of the position 119-132 severely decreased the reactivity of the R5 mAb to the oligopeptide. This ELISA also showed no apparent cross-reactivity with the other MAGE gene products (MAGE-1, -2, -3, -6, and -12). The minimum detectable level of MAGE-4 protein was determined to be 10 pg/well (100 pg/ml). The results suggest that this ELISA is a reliable and quantitative method to measure cellular MAGE-4 protein that is a potential target molecule for specific immunotherapy of human cancers.

Amino Acid Sequence↗
PubMed1995

Detection of MAGE-4 protein in lung cancers.

Expression of genes of the MAGE family, which encode tumor-rejection antigens recognized on HLA-AI and -Cw1601 by cytotoxic T lymphocytes (CTL), was investigated in lung cancers at the mRNA [MAGE-1, -2, -3/-6, and -4 (4a and/or 4b)] and protein (MAGE-4) levels. MAGE-1, -2, -3/-6 and -4 genes were expressed, respectively, at the mRNA level in 6, 7, 20 and 7 of 53 lung cancers (50 non-small-cell lung cancers and 3 small-cell lung cancers) by the reverse transcription-polymerase chain reaction (RT-PCR) method. Polyclonal antibody (Ab) and monoclonal antibody (MAb) against recombinant MAGE-4b protein were developed to detect MAGE-4 protein. Both the polyclonal Ab and the R5 MAb recognized a 45-kDa protein in extracts of MAGE-4 mRNA-positive lung cancers, and showed no apparent cross-reactivity with the other MAGE gene products except with MAGE-4a by immunoblot analyses and transfection experiments. MAGE-4 protein was detected on 13 of 44 (30%) lung cancers (18 to 55,989 pg/mg) by ELISA with the polyclonal Ab and R5 MAb. These 13 lung cancers consisted of 6 of 6 MAGE-4 mRNA-detectable and 7 of 38 MAGE-4 mRNA-undetectable lung cancers. Histologically, these comprised 7 of 10 squamous-cell carcinomas, 4 of 30 adenocarcinomas and 2 of 3 small-cell lung cancers. The proportions of MAGE gene-positive samples, at both the mRNA and protein levels, correlated with the size of the primary tumors and with regional node involvement. These results should provide important information on specific immunotherapy of lung cancers using MAGE gene products.

Animals↗
PubMed1995

Effects of antiplatelet drug dilazep dihydrochloride on anionic sites and extracellular matrix (ECM) components in glomerular basement membrane of STZ-induced diabetic rats.

A study of anionic sites in the glomerular basement membrane (GBM) of streptozotocin (STZ)-induced diabetic rats with or without treatment by an antiplatelet drug, dilazep dihydrochloride, is described. Expression of glomerular extracellular matrix (ECM) components was examined by immunofluorescence. Renal specimens were immersed in polyethyleneimine (PEI) as a cationic probe and then examined by electron microscopy. Renal specimens were also incubated with rabbit antirat type IV collagen, laminin, and fibronectin antisera and then stained with fluorescein isothiocyanate (FITC)-labeled goat antirabbit IgG antiserum. Mean values of proteinuria in the dilazep-treated diabetic rats were significantly decreased compared with those in nontreated diabetic rats. There was no significant correlation between the levels of proteinuria and those of creatinine clearance (CCr). Number of anionic sites on the GBM in the dilazep-treated diabetic rats were greater than those in diabetic rats. There was no significant difference in the staining of such ECM components between both rat groups. The authors concluded that the dilazep dihydrochloride might prevent anionic charges on the GBM and decrease the urinary excretion of proteins in STZ-induced diabetic rats.

Animals↗
PubMed1995

Determination of the glucurono-conjugated position in bile alcohol glucuronides present in a patient with cerebrotendinous xanthomatosis.

The determination of the glucurono-conjugated position in three bile alcohol glucuronides secreted in bile of a patient with cerebrotendinous xanthomatosis was carried out by a nuclear magnetic resonance study. The bile sample was extracted with ethanol and chromatographed on an ion-exchange column, a reverse-phase partition column and a silica gel column to isolate glucurono-conjugates of 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 25-tetrol, 5 beta-cholestane-3 alpha, 7 alpha 12 alpha, 23-tetrol, and 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 23, 25-pentol. Proton and 13C nuclear magnetic resonance spectra of the two biliary bile alcohol glucuronides, 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 25-tetrol glucuronide and 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 23, 25-pentol glucuronide were identical with those of the synthetic glucuronide 7 alpha, 12 alpha, 25-trihydroxy-5 beta-cholestane-3 alpha-O beta-D-glucopyranosyluronic acid and the isolated glucuronide 3 alpha, 7 alpha, 12 alpha, 25-tetrahydroxy-5 beta-cholestane-23-O-beta-D-glucopyranosyluronic acid from urine of a patient with cerebrotendinous xanthomatosis, respectively. Hence, the glucurono-conjugated positions of the biliary 25-tetrol glucuronide and the biliary 23,25-pentol glucuronide were C-3 and C-23, respectively. By comparison of the 13C chemical shift data with that of the unconjugated bile alcohol, 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 23-tetrol, the glucurono-conjugated position of the natural 23-tetrol glucuronide was determined to be C-23. Thus, the natural 23-tetrol glucuronide can be formulated as 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestane-23-O-beta-D-glucopyranosyluronic acid.

Bile↗
PubMed1995

Fourteen anonymous DNA markers of laboratory rats identified with arbitrarily primed polymerase chain reaction (AP-PCR).

In order to develop genetic markers in rats, arbitrarily primed polymerase chain reaction (AP-PCR) was performed with single primers originally designed for microsatellite loci, instead of primers with short-sized and arbitrary nucleotide sequences. Each primer generated reliable and reproducible segments under optimal conditions. The fourteen amplification products have been successfully mapped to rat chromosomes by either linkage analysis using backcross progeny or chromosomal assignment with somatic cell hybrids. All of the loci were located on different chromosomes from those of the microsatellite loci, suggesting that sequence-specifically designed single primers can produce anonymous segments of genomic DNA showing polymorphisms. These markers should contribute to finding linkages for traits of interest in rats.

Animals↗
PubMed1994

The gene responsible for LEC hepatitis, located on rat chromosome 16, is the homolog to the human Wilson disease gene.

We identified the rat homolog to the human Wilson disease (WD) gene as the gene responsible for hepatitis (hts) in the Long Evans Cinnamon (LEC) rat. A genetic study using fifty-three backcross progenies showed that the rat WD gene detected by Southern blotting using the human WD gene as a probe was tightly linked to the hts phenotype of the LEC rat with no recombination. LEC is a transcriptionally deficient mutant because no transcript of the rat WD gene could be found in the LEC rat by Northern blotting. This rat WD gene was mapped to 16q12.23-12.3 by fluorescence in situ hybridization and mouse x rat somatic cell hybrid analysis.

Animals↗
PubMed1994

Tremor and zitter, causative mutant genes for epilepsy with spongiform encephalopathy in spontaneously epileptic rat (SER), are tightly linked to synaptobrevin-2 and prion protein genes, respectively.

Spontaneously epileptic rat (SER) is a homozygote for both tremor (tm) and zitter (zi) genes and exhibits epilepsy-like seizures and spongiform encephalopathy. Genetic linkage analyses revealed that the tm and zi loci were tightly linked to the synaptobrevin-2 (Syb2) on chromosome 10 and the prion protein (Prnp) on chromosome 3, respectively. The genomic DNA sequences of Syb2 of the tm/tm (TRM) rats and exon 2 of the Prnp of the zi/zi (ZI) rats were identical to those of a control rat strain WTC. In addition, no difference was detected for expression of the Syb2 and Prnp on the Northern blot analyses of TRM, ZI and WTC brain, suggesting that the Syb2 and Prnp genes are not the tm and zi, respectively. The assignments of tm and zi to rat chromosome 10q24 and 3q35, however, will be the first step towards the positional cloning of the genes.

Animals↗