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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 343 records · Page 19Linked to original sources
PubMed1995

Dacron coronary graft obstruction after composite graft replacement of aortic root.

Obstruction of the left coronary ostial anastomosis is a rare late complication after composite graft replacement of the ascending aorta and the aortic valve with separate Dacron coronary grafts. Intimal proliferation caused by the turbulent blood flow at this site may be the cause of the obstruction, which is considered a possible cause of late cardiac events such as sudden death and global myocardial infarction. We describe a case of tight stenosis at the left coronary ostial anastomosis in a 38-year-old woman with Marfan's syndrome who had undergone a composite graft replacement that employed separate Dacron coronary grafts.

Adult↗
PubMed1995

A mirror image of the first and second branchial arch syndrome associated with cleft lip and palate in monozygotic twins.

A rare case of monozygotic twins revealing a mirror image of the first and second branchial arch syndrome with accessory ear and hemifacial microsomia, associated with unilateral cleft lip and palate, is presented. Although the concordance and/or discordance rate of monozygotic or dizygotic twins with cleft lip and palate is well reported, that of twinning of the first and second branchial arch syndrome has been very rarely described. First and second branchial arch syndrome occurs sporadically but cleft lip and palate are strongly related to the influence of environmental factors with a considerable hereditary tendency. The study of twinning of congenital anomalies is important in the investigation of the pathogenesis of genetic and environmental effects. The twins were diagnosed as monozygotic with almost complete certainty by ABO blood typing, HLA typing, finger prints, and DNA typing. Concordance was noticed, which suggests a hereditary tendency. Since concordance in these monozygotic twins was exhibited by a precise mirror image of first and second branchial arch syndrome, spinal scoliosis and cleft lip and palate, it is possible that an environmental factor induced these complex anomalies.

Abnormalities, Multiple↗
PubMed1995

Efficacy of flashlamp-pumped pulsed dye laser therapy for port wine stains: clinical assessment and histopathological characteristics.

Clinicopathological evaluation of flashlamp-pumped dye laser therapy for port wine stains was conducted on 474 subjects (135 male and 339 female) ranging in age from less than a year to 85 years (median = 17; lower quartile = 7 and upper quartile = 28). There was a significant variation in the rate of favourable response among lesion sites but the variation in relation to sex, age and radiation dose was not significant. Histological investigations of skin biopsy specimens from 23 subjects indicated that the mean depth of vessels is the main prognostic factor. The critical value (standard error) of the mean depth for a favourable response was estimated as 930(50) microns. Applications of this estimate to clinical prognosis are discussed.

Adolescent↗
PubMed1995

The novel variants of mb-1 and B29 transcripts generated by alternative mRNA splicing.

The Ig-alpha/Ig-beta heterodimers encoded by mb-1 and B29 genes, respectively, are crucial for the constitution of the B-cell receptor (BCR). We report here novel variants of mb-1 and B29 transcripts produced by alternative mRNA splicing. The proteins encoded by these variants are predicted to conserve transmembrane and cytoplasmic portions of Ig-alpha and Ig-beta but lack a part of the extracellular portions containing cysteine residues which are required for intramolecular and intermolecular S-S bonds. Transfection studies revealed that the variant mb-1 and B29 did not contribute to the BCR expression on cell surfaces. Although peripheral B cells contain small amounts of the variant mb-1 and B29 transcripts, treatment with an anti-IgM antibody, LPS or IL-4 induces a significant increase in amounts of the variant transcripts. These observations suggest that B-cell activation induces alternative splicing of mb-1 and B29 transcripts which encode proteins unable to constitute the BCR.

Alternative Splicing↗
PubMed1995

HLA and anti-GQ1b IgG antibody in Miller Fisher syndrome and Guillain-Barré syndrome.

We investigated serological human leukocyte antigen (HLA) types in patients with histories of Miller Fisher syndrome (MFS) and Guillain-Barré syndrome (GBS) with ophthalmoplegia, in whom serum anti-GQ1b IgG antibody was present during the acute phase. We examined class I antigens (A, B and C) in 32 patients and class II antigens (DR and DQ) in 30, but found no association. We conclude that particular serologically defined HLA types are not preferred for the immunoresponse of anti-GQ1b IgG antibody in MFS and GBS.

Autoantibodies↗
PubMed1995

A new B18 sequence (B*1802) from Asian individuals.

A new HLA-B18 allele (B*1802) derived from a Thai individual was sequenced. Comparison of this B18 nucleotide sequence with the published B*1801 sequence indicated that this Asian B18 allele has a nucleotide sequence different from that of B*1801. Three nucleotide changes were observed in exon 3, in which two substitutions at codon 97, AGG in B*1801 to AAT in the B*1802, result in an amino acid change from arginine to asparagine. The residue 97Asn has also been described in some B27 subtypes. A silent mutation was also observed at codon 99, TAC in B*1801 to TAT in the B*1802. This sequence has been reported in many class I alleles published so far. Moreover, 18 HLA-B18-positive samples were examined by the PCR-SSO method using specific probes for B*1801 and B*1802. The results demonstrated that three Asian samples possess B*1802 and share HLA-Cw7, DR12, and DQ7.

Alleles↗
PubMed1995

The determinant of severe cerebral dysfunction in patients undergoing emergency extracorporeal life support following cardiopulmonary resuscitation.

We investigated the factors associated with cerebral dysfunction in patients undergoing extracorporeal life support (ECLS) following conventional advanced cardiac life support (ACLS). The subjects were 9 patients in whom ECLS was started following ACLS because of intractable cardiac arrest. We investigated whether the irreversibility of cerebral dysfunction during ECLS was related to the cardiopulmonary resuscitation (CPR) time, arterial pH and blood gases, hemoglobin concentration (Hb), peak arterial pressure (PAP) before the start of ECLS and total doses of epinephrine and sodium bicarbonate administered during CPR. Two of the 3 patients who recovered consciousness were weaned from ECLS and survived, while all 6 patients who did not recover from coma were not weaned and died. There was no difference in the CPR time, Hb and PAP before the start of ECLS along with total doses of epinephrine and sodium bicarbonate administered during CPR between the patients who recovered consciousness and those who did not. In addition, there was no difference in arterial pH and blood gases except the arterial oxygen tension (PaO2) between the groups. The PaO2 values before the start of ECLS in the patients who remained in coma ranged from 34 to 58 mmHg, whereas those in the patients who recovered consciousness ranged from 132 to 442 mmHg. The PaO2 values before the start of ECLS in the patients who remained in coma were less than 60 mmHg, whereas those in the patients who recovered consciousness were over 60 mmHg. The present study suggests that hypoxemia during CPR may play a major role in severe cerebral dysfunction in patients undergoing ECLS and PaO2 during CPR.

Adult↗
PubMed1995

Lack of primary association between transporter associated with antigen processing genes and atopic dermatitis.

We examined polymorphisms of transporter associated with antigen processing (TAP) genes in 37 Japanese patients with atopic dermatitis and 52 control subjects. We have evaluated, again, the specificity polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method since our previous report and have also developed a mismatch PCR-RFLP method for discriminating two dimorphic sites of TAP1 gene and four dimorphic sites of TAP2 gene. Amplified products from genomic DNA were digested with restriction endonucleases: Sau3A1 for TAP1 codon 333 (Ile-Val), AccI for TAP1 codon 637 (Asp-Gly), and BfaI for TAP2 codon 687 (Stop-Gln). The other sites of TAP2 gene were analyzed by mismatch PCR-RFLP: AccII for TAP2 codon 379 (Val-Ile), RsaI for codon 565 (Ala-Thr), and MspI for codon 665 (Thr-Ala). We observed three TAP1 alleles and six TAP2 alleles. Infrequent allele TAP1 C was observed in one patient and one control subject. We did not identify any differences in TAP allele frequencies between those patients with atopic dermatitis and Japanese control subjects. Analysis of TAP gene polymorphisms will provide better understanding of susceptibility loci in HLA class II-associated disease because TAP genes are located between HLA-DQB1 and HLA-DPB1 loci.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Analysis of disease-associated amino acid epitopes on HLA class II molecules in atopic dermatitis.

We investigated the association between HLA class II alleles and severe atopic dermatitis with high serum IgE levels (greater than 8000 U/ml). The frequencies of HLA-DRB1*1302 and DQB1*0604 were increased, whereas the frequency of HLA-DQB1*0302 was decreased. A strong haplotype, HLA-DRB1*1302-DQB1*0604, has been reported in the Japanese population, and this haplotype is conserved in patients with AD. Further analysis of the amino acid epitopes on the HLA-DR beta 1 and DQ beta 1 domains revealed that DR beta 1 71Glu (RR = 5.71, p < 0.05) and DQ beta 1 30His (RR = 3.25 p < 0.01), and 57Val (RR = 3.13, p < 0.05) were increased in frequency. DR beta 1 71Glu was exclusively unique to DRB1*1302. DQ beta 1 30His was shared by the following alleles: DQ beta 1*0501, *0502, *0503, and *0604, which were all increased in patients with AD. DQ beta 1 57Val was shared by DQB1*0501 and *0604. A well-known haplotype, HLA-DRB1*1302-DQB1*0604, contains DR beta 1 71Glu and DQ beta 1 30His and 57Val. Therefore HLA-DR beta 1 71Glu and/or DQ beta 1 30His/57Val are considered to play the most important role in the development of atopic dermatitis.

Adolescent↗
PubMed1995

Childhood thyroid diseases around Chernobyl evaluated by ultrasound examination and fine needle aspiration cytology.

Screening by ultrasound examination and fine-needle aspiration cytological biopsy (FNA) was conducted in five regions in Belarus, Ukraine, and Russia to investigate the prevalence of childhood thyroid diseases around Chernobyl. Gomel, Zhitomir, Kiev, and the western area of Bryansk are the administrative regions where severe radioactive contamination occurred. The subjects from Mogilev, where contamination was relatively low, served as controls. Among 55,054 subjects (26,406 boys and 28,648 girls), the prevalence of ultrasonographic thyroid abnormalities such as nodule, cyst, and abnormal echogenity was significantly higher in the regions with severe contamination than in Mogilev. Of the 1,396 children showing echographic thyroid abnormalities 197 were selected for FNA, and a sample was successfully obtained for diagnosis from 171 (51 boys and 120 girls) of the 197 subjects. The aspirate was insufficient for diagnosis in the remaining 26 subjects. Thyroid cancer was encountered in four children (2.3%) from the contaminated regions, two children being from Gomel. The other thyroid diseases were follicular neoplasm, 6.4%; adenomatous goiter, 18.7%; chronic thyroiditis, 31.0%; and cyst, 24.0%, suggesting that a major cause of thyroid nodularity is nonneoplastic changes, mainly chronic thyroiditis and cysts. These results will serve as an important data base for further analyses and suggest that childhood thyroid diseases, including both neoplasms and immunological disorders, are consequences of radioactive fallout.

Adenocarcinoma, Follicular↗
PubMed1995

Optimal case-control matching in practice.

We illustrate modern matching techniques and discuss practical issues in defining the closeness of matching for retrospective case-control designs (in which the pool of subjects already exists when the study commences). We empirically compare matching on a balancing score, analogous to the propensity score for treated/control matching, with matching on a weighted distance measure. Although both methods in principle produce balance between cases and controls in the marginal distributions of the matching covariates, the weighted distance measure provides better balance in practice because the balancing score can be poorly estimated. We emphasize the use of optimal matching based on efficient network algorithms. An illustration is based on the design of a case-control study of hepatitis B virus infection as a possible confounder and/or effect modifier of radiation-related primary liver cancer in atomic bomb survivors.

Adult↗
PubMed1995

Antithrombotic effect of ticlopidine on occlusive thrombi of small coronary arteries in (NZWxBXSB)F1 male mice with myocardial infarction and systemic lupus erythematosus.

We examined the antithrombotic effect of ticlopidine on occlusive thrombi of small coronary arteries in (NZWxBXSB)F1 [(WxB)F1] male mice with myocardial infarction (MI) and systemic lupus erythematosus (SLE). Ticlopidine (3 and 10 mg/kg) was given to the mice as an additive to a standard laboratory diet from the time the mice were aged 16-24 weeks. The higher dose of ticlopidine significantly increased survival rate of the mice. In mice that received 10 mg/kg ticlopidine, the incidence of MI, the percentage of MI area (%MI), and the incidence and number of small coronary arteries with significant stenosis were significantly lower than in controls. The stenosed lesions were divided into occlusive thrombi related to acute MI and intimal thickening related to old MI. No mice had evidence of significant stenosis or thrombosis in the extramyocardial coronary arteries. Glomerulonephritis, blood urea nitrogen (BUN), and circulating immune complexes were not significantly different among the three groups. A high dose of ticlopidine prevented small coronary artery disease and MI and increased the survival of (WxB)F1 male mice, suggesting that this agent has an antithrombotic effect on occlusive thrombi of the small coronary arteries in such mice.

Analysis of Variance↗
PubMed1995

A murC gene in Porphyromonas gingivalis 381.

The gene encoding a 51 kDa polypeptide of Porphyromonas gingivalis 381 was isolated by immunoblotting using an antiserum raised against P. gingivalis alkaline phosphatase. DNA sequence analysis of a 2.5 kb DNA fragment containing a gene encoding the 51 kDa protein revealed one complete and two incomplete ORFs. Database searches using the FASTA program revealed significant homology between the P. gingivalis 51 kDa protein and the MurC protein of Escherichia coli, which functions in peptidoglycan synthesis. The cloned 51 kDa protein encoded a functional product that complemented an E. coli murC mutant. Moreover, the ORF just upstream of murC coded for a protein that was 31% homologous with the E. coli MurG protein. The ORF just downstream of murC coded for a protein that was 17% homologous with the Streptococcus pneumoniae penicillin-binding protein 2B (PBP2B), which functions in peptidoglycan synthesis and is responsible for antibiotic resistance. These results suggest that P. gingivalis contains a homologue of the E. coli peptidoglycan synthesis gene murC and indicate the possibility of a cluster of genes responsible for cell division and cell growth, as in the E. coli mra region.

Alkaline Phosphatase↗
PubMed1995

Neonatal alloimmune thrombocytopenia in Taiwan due to an antibody against a labile component of HPA-3a (Baka).

We report on two siblings who developed severe neonatal alloimmune thrombocytopenia (NAIT) due to an alloantibody against a labile component or components of the HPA-3a (Baka) antigen. The antibody reacted only with fresh, unfixed platelets by the solid-phase red cell adherence test, immunofluorescence test and mixed passive haemagglutination test. In the latter method, weakly fixed platelets also gave a weak positive reaction. Monoclonal-antibody-specific immobilization of platelet antigens and immunoblotting tests gave negative results. Our findings may possibly help to explain why in some cases of NAIT no platelet-specific antibody is demonstrable in tests with fixed or solubilized platelets.

Antibodies, Monoclonal↗
PubMed1995

DNA-based typing of human platelet antigen systems by polymerase chain reaction-single-strand conformation polymorphism method.

Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method has been established to discriminate genotypes for the human platelet antigen (HPA) systems HPA-1, HPA-2, HPA-3, HPA-4, and HPA-5. Gene fragments which contain polymorphic sequences corresponding to the HPA-1, HPA-2, HPA-3, HPA-4, and HPA-5 systems were PCR-amplified with specific primers. The amplified DNA was denatured and subjected to non-denaturing polyacrylamide gel electrophoresis followed by silver staining. The results obtained by the PCR-SSCP method were in good agreement with those of the allotypes determined by serological typing. Furthermore, the results agreed with those obtained by other DNA-based typing methods such as PCR-allele-specific restriction enzyme analysis and PCR-sequence-specific primer. These results indicate that PCR-SSCP is a simple and sensitive method for determining HPA genotypes and identifying unknown polymorphisms.

Antigens, Human Platelet↗