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Biomedical subjects

T Orii

Publications and source records attributed to T Orii.

At least 217 records · Page 12Linked to original sources
PubMed1993

A nonsense mutation (TGG [Trp116]-->TAG [Stop]) in CYP11B1 causes steroid 11 beta-hydroxylase deficiency.

Steroid 11 beta-hydroxylase deficiency (11 beta OHD), an autosomal recessive hereditary disease, accounts for 5-8% of cases of congenital adrenal hyperplasia. In this study, we carried out a molecular genetic analysis of CYP11B1 encoding steroid 11 beta-hydroxylase (P450c11) from a Japanese patient affected with this disease. Nucleotide sequence analysis of polymerase chain reaction-amplified products of the patient's genome revealed the occurrence of a stop codon in exon 2 due to a point mutation, TGG-->TAG (Trp116-->Stop). To further analyze the role of CYP11B2 encoding steroid 18-hydroxylase (P450c18) in the 11 beta OHD patient, CYP11B2 of the patient was also amplified and sequenced. In contrast to CYP11B1, there was no mutation in CYP11B2. Restriction fragment length polymorphism analysis indicated that the 11 beta OHD patient is homozygous and his unaffected parents are heterozygous for the mutation. When a cDNA corresponding to CYP11B1 of the 11 beta OHD patient was transfected into COS-7 cells, steroid 11 beta-hydroxylase activity was not detectable in mitochondria of the cells. These results demonstrate that intact P450c11 was not produced at all due to the nonsense mutation in CYP11B1 of the patient without any mutation in CYP11B2.

Adrenal Hyperplasia, Congenital↗
PubMed1993

Comparison of the MAST chemiluminescent assay system with RAST and skin tests in allergic children.

The MAST chemiluminescent assay (CLA) system uses enzyme-linked antihuman IgE and a chemiluminogenic substance to determine specific IgE antibodies. The MAST CLA system therefore not only makes unnecessary the precautions required for handling isotopic materials but has the advantage of long-term reagent stability. The MAST CLA system assay protocol consists of three steps: overnight incubation of serum, a 4-hour incubation with enzyme-labeled antibody, and a 30-minute chemiluminescent reaction, which produces a visible image (immunograph) on high-speed instant Polaroid film. We evaluated this MAST CLA system in 47 allergic children and compared the results with those for RAST and skin tests. Good correlations were found between MAST and RAST for house dust, Dermatophagoides farinae, cat, Japanese cedar pollen, egg white, and soybeans, the correlation coefficients being greater than 0.60. When the diagnostic results for MAST and RAST were compared with those of skin test reactions for house dust, Dermatophagoides farinae, cat, Japanese cedar pollen, egg white, and soybeans, MAST had a sensitivity of 85% and a specificity of 82% as compared with 88% and 83% for RAST. Further, an average of 2.1 different allergens were detected in one serum sample. These results suggest that the MAST CLA system can be used to detect specific IgE antibodies and that it provides accurate results for allergic children.

Adolescent↗
PubMed1993

[Clinical and molecular aspects of peroxisome-deficient disorders].

Peroxisome-deficient disorders including Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD) are characterized by the absence of peroxisomes associated with secondary multiple enzyme deficiencies and by a defect in the neuronal migration. Collaborative complementation studies revealed the presence of at least 9 genetic groups among these disorders. Clinical phenotypes did not correlate with the genetic grouping. Responsible gene for one of these groups (group F) was determined as peroxisome assembly factor-1 (PAF-1) by the functional cloning using peroxisome-deficient CHO cell mutant. A patient of group F was a homozygote with C to T transitions in PAF-1 gene which resulted in a nonsense mutation. These results will pave the way for the elucidation of mechanisms of peroxisome biogenesis and the pathophysiology of neuronal migration.

Adrenoleukodystrophy↗
PubMed1993

mu-Chain gene expression in common variable immunodeficiency.

Three patients with common variable immunodeficiency (CVID) were analyzed for translation from mu mRNA by the cell-free translation method and for expression of mu mRNA by northern blotting. In cases 1 and 2, the mu chain was not detected in the products by cell-free translation nor was mu mRNA detected by northern blotting. In case 3, mu mRNA was detected at a low level. This suggests that the disorders occur between rearrangement of the Ig genes and transcription of the C mu gene in cases 1 and 2, and that the functions of rearrangement and transcription are qualitatively preserved to a certain degree in case 3. Thus, the pathogeneses of CVID are variable and more research on regulatory mechanisms of B cell development is necessary to understand each case of CVID.

B-Lymphocytes↗
PubMed1993

Defective calcium-dependent signal transduction in B lymphocytes of a certain common variable immunodeficiency.

Two different common variable immunodeficiency patients were studied. Patient 1 showed hypogammaglobulinemia in all major classes of gammaglobulins and slightly reduced percentages of circulating CD19+ cells, CD20+ cells and surface IgG-or IgA-bearing cells with a normal percentage of surface IgM-bearing cells. Patient 2 showed normal levels in IgM with IgG and IgA deficiencies and almost normal percentages of circulating CD19+ cells, CD20+ cells and surface IgM-, IgG- or IgA-bearing cells. The proliferative responses of peripheral blood mononuclear cells to B cell mitogen, Staphylococcus aureus Cowan I, were reduced in patient 1 but not in patient 2. The intracellular calcium concentrations in lymphoblastoid cell lines (LCLs) transformed by Epstein-Barr virus from patient 2 were increased after anti-mu stimulation. The concentrations were scarcely increased in LCLs from patient 1. These results suggest that B cells of patient 1 have a defective Ca(2+)-dependent signal transduction pathway, resulting in a failure of cell activation and cell proliferation. The defect in B cells of patient 2 may exist on immunoglobulin gene switching or expression rather than the Ca(2+)-dependent signal transduction pathway.

Agammaglobulinemia↗
PubMed1993

[Mucopolysaccharidosis type VII: characterization of exonic point mutations and molecular heterogeneity].

We identified two different exonic point mutations causing beta-glucuronidase (beta G1) deficiency in three Japanese patients with mucopolysaccharidosis type VII. The beta G1-specific mRNA levels were normal. Sequence analysis of the full-length mutated cDNAs showed C-->T transitions, which resulted in a single Ala619-->Val change (case 1, a 8-year old female and case 2, a 24-year old male) and a Arg382-->Cys change (case 3, a 7-year-old female). Each of these two amino acid changes reduced the beta G1 activity of the corresponding mutant beta G1 expressed following transfection of COS cells with expression vectors harboring the mutated cDNAs.

Adult↗
PubMed1992

Molecular basis of 3-ketothiolase deficiency: identification of an AG to AC substitution at the splice acceptor site of intron 10 causing exon 11 skipping.

3-Ketothiolase deficiency (3KTD) is the result of a deficiency in mitochondrial acetoacetyl-CoA thiolase (T2). The molecular basis of 3KTD was analyzed in a patient (GK10) and his family at the protein, cDNA and gene levels. Protein analyses showed that GK10's T2 protein was undetectable in fibroblasts even with the pulse-protein labeling method and that his parents were carriers of 3KTD. Complementary DNA analyses with PCR showed that T2 cDNA in the patient lacked the normal exon 11 sequence and that his parents were obligatory carriers of the DNA sequence which canceled exon 11. When the PCR-amplified genomic fragments around exon 11 were sequenced, an AG to AC mutation at the 3' splice site of intron 10 was detected. This mutation is presumed to be responsible for exon 11 skipping.

Acetyl-CoA C-Acyltransferase↗
PubMed1992

Intermediate form of mucopolysaccharidosis type II (Hunter disease): a C1327 to T substitution in the iduronate sulfatase gene.

Hunter disease, an X-linked recessive lysosomal storage disorder, is caused by a deficiency in iduronate sulfatase activity. Sequence analysis of mRNA of fibroblasts of an intermediate phenotype patient showed a single C1327 to T nucleotide transition. This mutation resulted in a substitution of termination codon for normal arginine at position 443 of the peptide sequence. Expression studies with this abnormal cDNA in fibroblasts from the patient revealed a loss of enzymatic activity and instability of the mutated protein. We posturate that this mutation is probably the cause of the intermediate form of Hunter disease.

Base Sequence↗
PubMed1992

A human gene responsible for Zellweger syndrome that affects peroxisome assembly.

The primary defect arising from Zellweger syndrome appears to be linked to impaired assembly of peroxisomes. A human complementary DNA has been cloned that complements the disease's symptoms (including defective peroxisome assembly) in fibroblasts from a patient with Zellweger syndrome. The cause of the syndrome in this patient was a point mutation that resulted in the premature termination of peroxisome assembly factor-1. The homozygous patient apparently inherited the mutation from her parents, each of whom was heterozygous for that mutation.

Amino Acid Sequence↗
PubMed1992

Congenitally defective aldosterone biosynthesis in humans: the involvement of point mutations of the P-450C18 gene (CYP11B2) in CMO II deficient patients.

The gene for steroid 18-hydroxylase (P-450C18) has been recently assigned to encode corticosterone methyl oxidases Type I and Type II which were previously postulated to catalyze the final two steps in the biosynthesis of aldosterone in humans. Molecular genetic analysis of the P-450C18 gene is three patients from three different families affected with CMO II deficiency has indicated that a point mutation of CGG----TGG (181Arg----Trp) in exon 3 and one of GTG----GCG (386Val----Ala) in exon 7 occur exclusively in the gene of the patients. Analysis of PCR products by restriction enzymes (HapII and HphI) has indicated that the patients are homozygous and the unaffected parent is heterozygous for both mutations, in accordance with the established concept that CMO II deficiency is inherited in an autosomal recessive manner. These data clearly provide the molecular genetic basis for the characteristic biochemical phenotype of CMO II clinical variants.

Aldosterone↗
PubMed1992

Novel fatty acid beta-oxidation enzymes in rat liver mitochondria. I. Purification and properties of very-long-chain acyl-coenzyme A dehydrogenase.

Freeze-thawed rat liver mitochondria were extensively washed with potassium phosphate, pH 7.5, and the residue was extracted with 10 mM potassium phosphate, pH 7.5, 1% (w/v) sodium cholate, 0.5 M KCl. The four beta-oxidation enzyme activities of the washes and the last extract were assayed with substrates of various carbon chain lengths. Our data suggest that the last extract contains a novel acyl-CoA dehydrogenase and long-chain 3-hydroxyacyl-CoA dehydrogenase. A novel acyl-CoA dehydrogenase was purified. The molecular masses of the native enzyme and the subunit were estimated to be 150 and 71 kDa, respectively. One mole of enzyme contained 2 mole of FAD. These properties and immunochemical properties of the enzyme differed from those of three other acyl-CoA dehydrogenases: short-, medium-, and long-chain acyl-CoA dehydrogenases. Carbon chain length specificity of the enzyme differed from that of other acyl-CoA dehydrogenases. The enzyme was active toward CoA esters of long- and very-long-chain fatty acids, but not toward those of medium- and short-chain fatty acids. The specific enzyme activity was greater than 10 times that of long-chain acyl-CoA dehydrogenase when palmitoyl-CoA was used as substrate. We propose the name "very-long-chain acyl-CoA dehydrogenase" for this enzyme.

Acyl-CoA Dehydrogenase, Long-Chain↗
PubMed1992

Novel fatty acid beta-oxidation enzymes in rat liver mitochondria. II. Purification and properties of enoyl-coenzyme A (CoA) hydratase/3-hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase trifunctional protein.

Long-chain 3-hydroxyacyl-CoA dehydrogenase was extracted from the washed membrane fraction of frozen rat liver mitochondria with buffer containing detergent and then was purified. This enzyme is an oligomer with a molecular mass of 460 kDa and consisted of 4 mol of large polypeptide (79 kDa) and 4 mol of small polypeptides (51 and 49 kDa). The purified enzyme preparation was concluded to be free from the following enzymes based on marked differences in behavior of the enzyme during purification, molecular masses of the native enzyme and subunits, and immunochemical properties: enoyl-CoA hydratase, short-chain 3-hydroxyacyl-CoA dehydrogenase, peroxisomal enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase bifunctional protein, and mitochondrial and peroxisomal 3-ketoacyl-CoA thiolases. The purified enzyme exhibited activities toward enoyl-CoA hydratase and 3-ketoacyl-CoA thiolase together with the long-chain 3-hydroxyacyl-CoA dehydrogenase activity. The carbon chain length specificities of these three activities of this enzyme differed from those of the other enzymes. Therefore, it is concluded that this enzyme is not long-chain 3-hydroxyacyl-CoA dehydrogenase; rather, it is enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase trifunctional protein.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1992

Complementation study of peroxisome-deficient disorders by immunofluorescence staining and characterization of fused cells.

Genetic heterogeneity in peroxisome-deficient disorders, including Zellweger's cerebrohepatorenal syndrome, neonatal adrenoleukodystrophy and infantile Refsum disease, was investigated. Fibroblasts from 17 patients were fused using polyethylene glycol, cultivated on cover slips, and the formation of peroxisomes in the fused cells was visualized by immunofluorescence staining, using anti-human catalase IgG. Two distinct staining patterns were observed: (1) peroxisomes appeared in the majority of multinucleated cells, and (2) practically no peroxisomes were identified. Single step 12-(1'-pyrene) dodecanoic acid/ultraviolet (P12/UV)-selection confirmed that the former groups were resistant to this selection, most of the surviving cells contained abundant peroxisomes, and the latter cells died. In the complementary matching, [1-14C]lignoceric acid oxidation and the biosynthesis of peroxisomal proteins were also normalized. Five complementation groups were identified. Group A: Zellweger syndrome and infantile Refsum disease; Groups B, C and D: Zellweger syndrome; Group E: Zellweger syndrome, neonatal adrenoleukodystrophy and infantile Refsum disease. We compared these groupings with those of Roscher and identified eight complementation groups. There was no obvious relation between complementation groups and clinical phenotypes. These results indicate that the transport, intracellular processing and function of peroxisomal proteins were normalized in the complementary matching and that at least eight different genes are involved in the formation of normal peroxisomes and in the transport of peroxisomal enzymes.

Adrenoleukodystrophy↗
PubMed1992

Identification of TaqI polymorphism in the mitochondrial acetoacetyl-CoA thiolase gene and familial analysis of 3-ketothiolase deficiency.

We analyzed the mitochondrial acetoacetyl-CoA thiolase gene (T2) by Southern blotting. Fifteen unrelated healthy individuals and members of five families with 3-ketothiolase deficiency (3KTD) were analyzed. We found a TaqI polymorphism, the heterozygosity of which was calculated to be 0.5 among healthy Japanese individuals. This restriction fragment length polymorphism (RFLP) proved to be useful for detecting 3KTD patients and its obligatory carriers, at the DNA level and in two out of five 3KTD families. This polymorphism was found to be generated by the presence/absence of a TaqI site in intron 9 of the T2 gene. With in vitro amplification of the genomic region around the TaqI site, this RFLP can be detected within 2 days.

Acetyl-CoA C-Acetyltransferase↗