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Biomedical subjects

T Orii

Publications and source records attributed to T Orii.

At least 181 records · Page 10Linked to original sources

A wild-type mu s C-terminal gene is expressed in Bloom's syndrome cells.

Selective IgM deficiency is found commonly in patients with Bloom's syndrome (BS). Serum IgM concentrations were low though serum IgG and IgA concentrations were normal in both patients with BS included in the study. In a previous study the authors showed that selective IgM deficiency in BS is due to an abnormality in the maturation of surface IgM-bearing cells into IgM-secreting cells and a failure of secreted mu (mu s) mRNA synthesis. The membrane-bound mu (mu m) and mu s mRNA are produced from transcripts of a single immunoglobulin mu gene by alternative RNA processing pathways. The control of mu s mRNA synthesis depends on the addition of poly(A) to mu s C-terminal segment. The study described here demonstrated that there was no mutation or deletion in the sequence including mu s C-terminal coding sequence, the RNA splice site (GG/TAAAC) at the 5' end of mu s C-terminal segment, and the AATAAA poly(A) signal sequence, and second GT-rich element immediately down-stream of the cleavage site in both patients.

Adult↗

Suppression of proliferative responses of lymphocytes to food antigens by an anti-allergic drug, ketotifen fumarate, in patients with food-sensitive atopic dermatitis.

Experimental studies have shown that ketotifen fumarate inhibits reaginic antibody-mediated hypersensitivity reactions. In this study, the proliferative responses of peripheral blood mononuclear cells (PBMCs) to ovalbumin (OA) in children with atopic dermatitis (AD), who are sensitive to hen's egg, were significantly higher than those of healthy children. The proliferative responses of PBMCs to OA were dose-dependently inhibited by ketotifen in patients with hen's egg-sensitive AD. Moreover, the inhibition resulted from the effects of ketotifen on T cells. In contrast, the proliferative responses of PBMCs to phytohemagglutinin and tetanus toxoid were not inhibited by ketotifen. These results suggest that ketotifen inhibits food antigen-specific proliferative responses of PBMCs in patients with food-sensitive AD.

Child, Preschool↗

Timing of onset of allergic symptoms as a response to a double-blind, placebo-controlled food challenge in patients with food allergy combined with a radioallergosorbent test and the evaluation of proliferative lymphocyte responses.

The timing of onset of allergic symptoms in a double-blind, placebo-controlled food challenge (DBPCFC) was combined with a radioallergosorbent test (RAST) and evaluation of proliferative responses of peripheral blood mononuclear cells (PBMCs) in 27 atopic dermatitis patients with hen's egg allergy. Of the 27 patients, 11 showed reactions within 2 h (immediate group), and 16 showed reactions after more than 2 h (nonimmediate group) after ingestion of hen's egg. The RAST scores for hen's egg in the immediate group were significantly (p < 0.01) higher than those in the nonimmediate group, while the proliferative responses of PBMCs to ovalbumin in the nonimmediate group were significantly (p < 0.01) higher than those in the immediate group. These results suggest that the RAST values are related to immediate allergic symptoms in DBPCFC and the proliferative responses of PBMCs are related to nonimmediate allergic symptoms in DBPCFC. The timing of onset of allergic symptoms in DBPCFC will render DBPCFC more useful in the diagnosis of food allergy, including the late-onset reactions to foods.

Adolescent↗

Identification of a novel exonic mutation at -13 from 5' splice site causing exon skipping in a girl with mitochondrial acetoacetyl-coenzyme A thiolase deficiency.

We identified a novel exonic mutation which causes exon skipping in the mitochondrial acetoacetyl-CoA thiolase (T2) gene from a girl with T2 deficiency (GK07). GK07 is a compound heterozygote; the maternal allele has a novel G to T transversion at position 1136 causing Gly379 to Val substitution (G379V) of the T2 precursor. In case of in vivo expression analysis, cells transfected with this mutant cDNA showed no evidence of restored T2 activity. The paternal allele was associated with exon 8 skipping at the cDNA level. At the gene level, a C to T transition causing Gln272 to termination codon (Q272STOP) was identified within exon 8, 13 bp from the 5' splice site of intron 8 in the paternal allele. The mRNA with Q272STOP could not be detected in GK07 fibroblasts, presumably because pre-mRNA with Q272STOP was unstable because of the premature termination. In vivo splicing experiments revealed that the exonic mutation caused partial skipping of exon 8. This substitution was thought to alter the secondary structure of T2 pre-mRNA around exon 8 and thus impede normal splicing. The role of exon sequences in the splicing mechanism is indicated by the exon skipping which occurred with an exonic mutation.

Acetyl-CoA C-Acetyltransferase↗

The importance of prevention of sinusoidal endothelial cell injury during cold preservation of liver graft.

We investigated adenosine triphosphate (ATP) synthesis, lipid peroxidation, and activities of radical scavenging enzymes in mitochondria, as well as the ultrastructural morphological changes during cold preservation of swine liver grafts (n = 6) with either Euro Collins (EC) or University of Wisconsin (UW) solutions. The liver, harvested by a standard procedure, was preserved in one of the solutions at 4 degrees C. The values of the total adenine nucleotide and mitochondrial respiratory control ratio (RCR), an index of ATP synthesis, decreased gradually for up to 24 hr during preservation with either of the two solutions and there was no statistical difference between them. Chemiluminescence of mitochondria, an index of lipid peroxidation, in the graft preserved with EC solution or UW solution decreased, and after 24 hr there was no significant difference between the two solutions. Activities of radical scavenging enzymes were well maintained in any of the two solutions. Transmission electron microscopy (TEM) findings showed that the sinusoidal endothelial cells were preserved much better with UW solution than with EC solution even after 12 hr preservation. We concluded that UW solution, more effective for the protection against injuries of the sinusoidal endothelial cells during cold preservation, leads to better results in clinical transplantation, but this solution has no protective effects on energy production, nor radical scavenging enzyme activities of mitochondria. In the maintenance of liver graft viability, protection of the sinusoidal microcirculatory disturbance is more important than that of the mitochondrial function.

Adenosine↗

Characterization of infiltrating CD4+ cells in atopic dermatitis using CD45R and CD29 monoclonal antibodies.

Tissue sections from the skin of patients with atopic dermatitis were investigated by means of hematoxylin-eosin staining, the avidin-biotin-peroxidase complex method, and double-labeling immunofluorescence using monoclonal antibodies to cell-surface antigens, including CD45R and CD29. In skin lesions of patients with atopic dermatitis, the epidermis was spongiotic and hyperplastic with little cellular infiltrate. Perivascular dermal infiltrate was significant and consisted primarily of mononuclear cells. The majority of the infiltrating mononuclear cells in the skin of patients with atopic dermatitis were CD4+ cells. Langerhans' cells were also increased in number. Furthermore, we investigated the subsets in the infiltrating CD4+ cells by double-labeling immunofluorescence using CD45R and CD29 monoclonal antibodies. Among the infiltrating CD4+ cells, CD4+CD29+ cells were dominant and CD4+CD45R+ cells were also present.

Adolescent↗

Sensitization to sugar cane pollen in Okinawan allergic children.

Specific IgE antibodies to sugar cane pollen were investigated in seventy-four Okinawan children who suffered from allergic disorders. Only two (2.7%) with asthma of the 74 patients had specific IgE antibodies to sugar cane pollen as well as house dust and Dermatophagoides farinae. However, they have no histories of their symptoms being aggravated when sugar cane flowers bloom. From these results, the sensitization to sugar cane pollen exists in a small number of Okinawan allergic children, however, the low incidence of positivity could reflect lack of exposure to sensitizing doses of sugar cane pollen in these children.

Adolescent↗

IgG subclass levels and southern analysis of DNA in primary immunodeficiency diseases including IgG subclass deficiency.

Serum IgG subclass levels are reported for twenty patients with primary immunodeficiency diseases, including four patients with IgG subclass deficiency, using an enzyme-linked immunosorbent assay with monoclonal antibodies. The disorder of each patient with IgG subclass deficiency seemed to be heterogeneous immunologically and clinically. One had complete IgG2-IgG4 deficiency, another had IgG2-IgG4-IgA deficiency and the other two had IgG2-IgA deficiencies. We did not find any structural-gene deletions in the constant region of the human immunoglobulin heavy-chain locus. Although the possibility of defects in genes controlling immunoglobulin expression, or small mutations, remains, these results suggest that IgG subclass deficiency is not always linked to particular structural-gene deletions.

Adolescent↗

The design of oral sustained-release theophylline dosing after conversion from intravenous to oral therapy.

We studied the design of oral sustained-release theophylline dosing after conversion from constant aminophylline infusion. Twelve children with bronchial asthma (9 boys and 3 girls) were evaluated in this study. Each patient received a constant intravenous administration of aminophylline for 4-10 days. Three hours after conversion from constant aminophylline infusion, they received oral sustained-release theophylline twice daily at 12-hour intervals. Blood samples were obtained at least once during the aminophylline infusion, just before conversion from the aminophylline infusion, and 0, 3 and 6 hours, and 4-5 days after administering oral theophylline. Pharmacokinetic parameters were estimated using the serum theophylline concentrations that were obtained during constant aminophylline infusion. These estimates of pharmacokinetic parameters were used to predict the serum theophylline concentrations during oral theophylline therapy. Predicted serum theophylline concentrations using individual pharmacokinetic parameters were fitted with actual measured values in this study. When switching a patient from intravenous aminophylline to sustained-release oral theophylline, the use of Bayesian analysis of serum theophylline concentration values obtained during intravenous therapy works well in predicting serum theophylline concentrations and in determining oral dosages that maximize the drug's effectiveness.

Administration, Oral↗

Prediction of steady-state serum theophylline concentration in children by first-order and zero-order absorption models.

We estimated the pharmacokinetic characteristics of theophylline in children with bronchial asthma after multiple oral dosing of Theo-Dur, in order to determine whether the absorption of the drug is best described by a zero-order absorption kinetic model (0-order model) or a first-order absorption kinetic model (1-order model). Thirteen children with bronchial asthma were evaluated in this study. Each patient received Theo-Dur twice daily at 12-hour intervals. Blood samples were taken at 0, 3, 6, 9 and 12 hours after the administration; plasma theophylline concentration was determined by the fluorescence polarization immuno assay method. Pharmacokinetic parameters for each patient were estimated by a one-compartment open model with 0-order or 1-order absorption and 1-order elimination rate constants. The regression curve predicted using the 0-order model fitted well to the observed value. In contrast, the use of the 1-order model was overestimated considerably in the absorption phase the precision of the prediction using the 0-order model was better than the use of the 1-order model. This study suggests that the 0-order model gave better estimated pharmacokinetic parameters when applied to Theo-Dur than did the 1-order model in children.

Adolescent↗

Expression of VpreB gene in common variable immunodeficiency.

We analyzed the expression of the VpreB gene in 5 common variable immunodeficiency (CVI) patients. There was no deletion or large mutation as compared with control DNA by Southern blotting. In the peripheral blood mononuclear cells of CVI patients, expression of the VpreB gene was not detected by polymerase chain reaction. These results suggest that there were no immature B cells such as pro- or pre-B stages in the peripheral blood mononuclear cells of these CVI patients. In B lymphoblastoid cell line (LCL) cells, expression of VpreB gene was observed in patients and Manca cells. The results suggest that the stages of these LCL cells may be a traditional stage between pre-B and mature B cell. As for the Manca cell, our result is in accordance with a recent report that surface immunoglobulin-positive cell lines also express the pre-B-related genes.

B-Lymphocyte Subsets↗

Cloning of a human gene, PIG-F, a component of glycosylphosphatidylinositol anchor biosynthesis, by a novel expression cloning strategy.

The glycosylphosphatidylinositol (GPI)-anchored proteins are widely distributed in eukaryotic cells, from yeasts to mammals. A number of proteins, such as glycosyltransferases, are necessary for GPI anchor biosynthesis. Cloning of genes encoding these proteins is required for analyses of their nature and the biosynthetic pathway. Here we report a new method of expression cloning that is applicable to many mutant rodent and human cells, and its application for cloning a human cDNA termed PIG-F (for Phosphatidyl-Inositol-Glycan class F) using a Thy-1-negative mutant murine thymoma cell line of complementation class F. PIG-F takes a part in the step of transfer of ethanolamine phosphate to the GPI intermediate containing three residues of mannose. This expression cloning strategy is applicable to the identification of not only other genes involved in GPI anchor biosynthesis but also human disease-associated genes using mutant mammalian cell lines.

Amino Acid Sequence↗

Congenitally defective aldosterone biosynthesis in humans: inactivation of the P-450C18 gene (CYP11B2) due to nucleotide deletion in CMO I deficient patients.

CYP11B2, the gene coding for steroid 18-hydroxylase (P-450C18), has been recently shown to be the same gene as that for corticosterone methyl oxidase type I and type II (CMO I & II) which were previously postulated to catalyze the final two steps in the biosynthesis of aldosterone in humans. Molecular genetic analysis of CYP11B2 of three patients affected with CMO I deficiency has revealed that deletion of 5 nucleotides occurs exclusively in exon 1, resulting in a frameshift to form a stop codon in the same exon. Thus, P-450C18 is not produced at all due to the mutation, causing a complete lack of aldosterone biosynthesis in the patients. Restriction fragment length polymorphism analysis has demonstrated that the patients are homozygous and the unaffected parent is heterozygous as for the mutation, indicating that CMO I deficiency is inherited in an autosomal recessive manner. These results provide the molecular genetic basis for the characteristic biochemical phenotype of CMO I deficient patients.

Aldosterone↗

Balanced complex rearrangement involving chromosomes 8, 9, and 12 in a normal mother, derivative chromosome 9 with recombinant chromosome 12 in her daughter with minor anomalies.

We report on a 19-month-old girl with a derivative chromosome 9 and a recombinant chromosome 12 resulting from a maternal balanced complex rearrangement involving chromosomes 8, 9, and 12. The karyotype of the phenotypically normal mother was 46,XX,t(8;12) (9;12) (8qter-->8p23::12q12-->12q 15::9q32-->9qter;9pter-->9q32::12q15--> 12qter; 12pter-->12q12::8p23-->8pter). The child's karyotype was 46,XX,-9,-12, +der(9) (9pter-->9q32::12q15-->12qter), +rec(12) (12pter-->12q15::9q32-->9qter) mat. The child had severe growth retardation, minor anomalies including trigonocephaly, hypertelorism, broad nasal root, apparently low-set and posteriorly angulated ears, triangular face, pectus carinatum, clinodactyly of fifth fingers, and almost normal psychomotor development. To the best of our knowledge, there have been only 3 previous reports of recombination derived from parental complex chromosome rearrangements. In the recombination products, the chromosomes were apparently balanced and the offspring had no clinical abnormalities. The present case exhibited abnormalities and may have a submicroscopic aberration of 12q arising from crossing over during maternal meiotic pairing, although her chromosomes appeared to be balanced.

Abnormalities, Multiple↗

Molecular studies of mitochondrial acetoacetyl-coenzyme A thiolase deficiency in the two original families.

We describe mutations identified in stored skin fibroblast cell lines from two original probands (JB and JM), first reported with 2-methylacetoacetic aciduria, and shown later to have a deficiency of the K(+)-activated enzyme, mitochondrial acetoacetyl-coenzyme A thiolase (T2). JB is homozygous for a 4-base insertion (GCAG) which is derived mutation. The primary mutation is an AG/gt to AG/gc transition at the 5'-splice-junction site in intron 11. An alternative splice site 4 bp downstream (Ggcag/gt) is used which causes a frame shift and replaces 39 C-terminal residues by 70 nonfunctional residues. JM is homozygous for a mutation in the translation-initiation codon (ATG to AAG). By expression analyses the JB mutation (IVS11nt2) causes an unstable T2 polypeptide and the JM mutation (M1K) severely impairs T2 mRNA translation. The JB allele associates with Dutch ancestry (no consanguinity) and the JM allele with Chilean ancestry (distant consanguinity).

Acetyl-CoA C-Acetyltransferase↗