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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 397 records · Page 22Linked to original sources

Polymorphisms of transporter associated with antigen processing genes in atopic dermatitis.

We investigated polymorphisms of transporter associated with antigen process (TAP) genes in atopic dermatitis. We developed a polymerase chain reaction-restriction fragment length polymorphism method for discriminating TAP alleles. Genomic DNA was obtained from 29 Japanese patients with atopic dermatitis and 35 control subjects. Dimorphic regions of TAP1 and TAP2 genes were amplified by polymerase chain reaction. Amplified products were digested with restriction endonucleases to determine TAP alleles: Sau3A1 for TAP1 codon 333 (Ile-Val), AccI for TAP1 codon 637 (Asp-Gly), and EcoRII for TAP2 codon 687 (Gln-Stop). We observed four alleles for TAP1 and dimorphism for TAP2 codon 687. Six of 35 controls had the TAP1 D allele, which has been reported to be a rare allele in Caucasian populations. Gene frequency of TAP1 637Asp exhibited a tendency to increase in the patients with atopic dermatitis. TAP1 637Asp and TAP1 A alleles were estimated to constitute a haplotype with DRB1* 1302-DQB1*0604 and DRB1*0803-DQB1*0601 in the Japanese population. Because TAP1 and TAP2 genes are located between HLA-DQB1 and -DPB1 loci, analysis of TAP gene polymorphisms will be useful for a better understanding of susceptibility loci in HLA class II-associated disease.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

HLA and atopic dermatitis with high serum IgE levels.

Patients with atopic dermatitis usually exhibit allergen-specific IgE antibodies against several environmental antigens. HLA restriction is presumed to be involved in the recognition of such antigens, but several previous reports have so far failed to find a significant association between atopic dermatitis and HLA antigens. In this study we examined 38 unrelated Japanese patients with severe atopic dermatitis and high serum IgE levels (greater than 800 U/ml). We investigated the serological HLA types and HLA class II alleles in this group of patients with atopic dermatitis. Frequencies of HLA-A24, A33, Cwblank, B44, DR13 and HLA-DRB1*1302, DQB1*0604, DPB1*0301 alleles were increased in the patients. In contrast, frequencies of HLA-Cw1, Bw6, DR4, DR53, and HLA-DQB1*0302 allele were decreased. However, none of these remained significant after p values were corrected. Further study on HLA association with atopic dermatitis through characterization of specific antigens or antigen epitopes is needed.

Adolescent↗

Effect of anti-inflammatory agent etodolac on antigen-induced contractions of the trachea and lung parenchyma of guinea pigs.

Etodolac, which inhibits the activity of cyclooxygenase, did not affect antigen-induced contractions of the trachea and lung parenchyma of guinea pigs. Indomethacin tended to enhance antigen-induced contractions of the trachea and significantly enhanced contractions of the lung parenchyma. The inhibitory activity of AA-861, a 5-lipoxygenase inhibitor, in antigen-induced contractions of the trachea and lung parenchyma was more potent than that of ozagrel, a thromboxane A2 (TXA2) inhibitor. Thus, lipoxygenase products played a more important role than TXA2 in antigen-induced contractions of the trachea and lung parenchyma. These results suggest that the enhancement of antigen-induced contractions by indomethacin might be due to an increase in anaphylactic release of lipoxygenase products through the inhibition of cyclooxygenase. Since etodolac did not enhance antigen-induced contractions, we attempted to determine whether or not etodolac inhibits 5-lipoxygenase. Etodolac was found to have no effect on 5-lipoxygenase activity. Therefore, the low adverse effect of etodolac on antigen-induced contractions of the airway may be due to its weak inhibition of cyclooxygenase in the airway. These results suggest that etodolac would have only a very slight, if any, adverse effect on the airway in patients with asthma.

Animals↗

Effects of midazolam and flumazenil on carotid sinus baroreflex control of circulation in rabbits.

We have studied the effects of midazolam and flumazenil on the carotid sinus baroreflex, by examining mean arterial pressure (MAP) and heart rate (HR) responses to partial or complete bilateral carotid occlusion (BCO) in 12 conscious rabbits after aortic denervation. In eight rabbits, the responses to complete BCO were evaluated before and after cumulative doses of midazolam 0.5 and 1.0 mg kg-1, and after flumazenil 0.3 mg kg-1 following administration of midazolam. Midazolam and flumazenil had no effect on MAP or HR before complete BCO and neither affected the MAP response to complete BCO. Midazolam 0.5 and 1.0 mg kg-1 decreased the HR response to 60% and 58% of control, respectively. Flumazenil restored the midazolam-induced depression of the HR response to the control level. In the other four rabbits, we examined the MAP and HR responses to partial BCO (carotid artery pressure reduced by 5, 10 and 20 mm Hg) before and after midazolam 0.5 mg kg-1 and after flumazenil 0.3 mg kg-1 following administration of midazolam. The response to partial occlusion showed the same tendency as the response to complete BCO. These results indicate that midazolam attenuated the HR response of the carotid sinus baroreflex, flumazenil restored this midazolam-induced depression and neither drug affected the MAP response.

Animals↗

Postantibiotic effects and postantibiotic sub-MIC effects of benzylpenicillin on viridans streptococci isolated from patients with infective endocarditis.

We investigated the postantibiotic effects (PAEs) and the postantibiotic sub-MIC effects of benzylpenicillin on three strains of viridans streptococci isolated from infective endocarditis patients. The PAEs of benzylpenicillin on penicillin tolerant Streptococcus sanguis TW-70 (0.4-3.9 h), penicillin tolerant S. sanguis TW-80 (0.3-6.3 h) and nontolerant Streptococcus oralis TW-186 (0.5-3.1 h) were dependent on exposure time. The PAEs were not concentration dependent for S. sanguis TW-70 and S. sanguis TW-80 above the MIC, and for S. oralis TW-186 above 16 x MIC. The antimicrobial effects of benzylpenicillin at sub-MIC concentrations were examined in bacteria pretreated with benzylpenicillin (8 x MIC) for 2 h and compared with untreated bacteria. At the sub-MICs tested, the regrowth of pretreated S. oralis TW-186 cells was more prolonged than that of untreated cells and bactericidal action was seen only in pretreated cells. These effects (so-called 'postantibiotic' sub-MIC effects') were not observed in penicillin tolerant S. sanguis TW-70. The presence of the postantibiotic sub-MIC effect may be an important factor in determining the dosing regimen for infective endocarditis.

Endocarditis, Bacterial↗

Fallout radioactivity in soil and food samples in the Ukraine: measurements of iodine, plutonium, cesium, and strontium isotopes.

To estimate the level and distribution of fallout attributable to the 26 April 1986 Chernobyl nuclear power station accident in the Ukraine, we sampled several kinds of substances at Korosten, Zhitomir and at Katyuzhanka, Vishgorod, Kiev in the Ukraine, and measured the radioactivity of 137Cs, 134Cs, 90Sr, 129I, 238Pu, 239,240Pu, and the density of 127I (stable). The substances investigated were soil, dry milk, wheat, rye, drinking water, and mushrooms. Except for the mushrooms collected, which were sampled at Katyuzhanka, Vishgorod, and at Kiev, all substances were at Korosten, Zhitomir. The activity of 137Cs, 134Cs, 90Sr, 238Pu, and 239,240Pu were all higher in soil and mushrooms than in the other four substances. The activity of 137Cs was 960 and 1,210 Bq kg-1 in the two soil samples and 6,110 Bq kg-1 in the mushrooms. The activity of 134Cs was approximately 15% of 137Cs in the two soil samples while < 3% of 137Cs in the mushrooms. The activity concentration level of 90Sr as compared to 137Cs concentration was 15-31% in food samples other than mushrooms but only 1.9% in mushrooms and 1.4 and 1.2% in the two soil samples. The radioactivity ratios, 238Pu: 239,240Pu and 239,240Pu: 137Cs, suggested that the proportion of cesium radioisotopes and 239,240Pu in the soil attributable to the Chernobyl accident was approximately 100% and 10-20%, respectively, while approximately 100% of 239,240Pu in the mushrooms was attributable to the accident. The activity of 129I was small but the ratio of 129I: 127I in the two soil samples was 4.3 x 10(-8) and 1.0 x 10(-7), which is approximately 10 times larger than that in the global fallout. These results suggest that the areas where the soil was sampled are iodine-deficient and were contaminated slightly by the Chernobyl accident.

Accidents↗

137Cs concentration among children in areas contaminated with radioactive fallout from the Chernobyl accident: Mogilev and Gomel oblasts, Belarus.

The level of radiation exposure in children in Belarus caused by the Chernobyl accident was investigated on the basis of whole body 137Cs count. The subjects were 10,062 children (4,762 boys and 5,300 girls) in Mogilev and Gomel, Belarus, who received Chernobyl Sasakawa Health and Medical Cooperation Project health examinations from May 1991 to December 1992 and who were 5-16 y old at the time of examination. The median whole body 137Cs count per body weight varied from 21-48 Bq kg-1 and from 28-126 Bq kg-1 in Mogilev oblast and Gomel oblast, respectively. (The "oblast" is the largest administrative district constituting the country. Belarus consists of 6 oblasts). Corresponding annual effective dose equivalents were all less than the public dose limit of 1 mSv y-1, but the observed levels in the children were considerably higher than the average level of 2.3 Bq kg-1 reported in the past for the former Soviet Union.

Accidents↗

Relationship between dental caries experience of a group of Japanese kindergarten children and the results of two caries activity tests conducted on their saliva and dental plaque.

To establish a dental caries preventive programme in 4- and 5-year-old children, caries activity tests were used to assess salivary levels of mutans streptococci (using the Mucount test, Showa Yakuhin, Japan) and the acidogenic ability of dental plaque bacteria (using the Cariostat test, Sankin, Japan) in 260 kindergarten children. The relationships between the results of these two tests and the dental caries experience (dfs) of the children was evaluated. There was a significant positive correlation between the results of the Mucount and Cariostat tests in the total group of subjects. However, 91 subjects (35%) gave conflicting results with the two tests. These subjects were divided into two groups: one group (group B) included Mucount-negative and Cariostat-positive subjects, and the other group (group C) included Mucount-positive and Cariostat-negative subjects. Group B had a significantly higher mean dfs score than a group that was negative on both tests (group A). On the other hand, no significant difference in mean dfs score was observed between group C and group A. These findings suggested that mutans streptococci levels alone are an insufficient indicator for assessing dental caries activity of children at these ages and that the role of lactobacilli and other aciduric bacteria should be considered. It was concluded that assessment of caries activity using both Mucount and Cariostat tests is useful for a dental caries preventive programme for children of these ages.

Child, Preschool↗

Sequence analysis of serological HLA-A11 split antigens, A11.1 and A11.2.

HLA-A11 has two serologically-defined splits, A11.1 and A11.2, and two alleles coding for HLA-A11, A*1101 and A*1102, have been published so far. In order to understand the relationship between the serological subtypes and the amino acid sequences, we have sequenced the alleles coding for A11.1 and A11.2. The results demonstrated that A11.1 split antigen is encoded by A*1101 and A11.2 split antigen is encoded by A*1102. Moreover, we obtained the sequences of exons 1, 5, 6, 7, and 8 of A*1102, which were not reported previously. In addition, we could distinguish A*1101 from A*1102 using a PCR-SSCP method, confirming that A11.1 carried by different HLA haplotypes has the same sequence.

Amino Acid Sequence↗

Effective method for discriminating between oral bacterial and human alkaline phosphatase activity.

Alkaline phosphatase (ALPase) activity was quantitatively compared in various kinds of oral bacteria. High ALPase activity was detected in 3 species of periodontal bacteria, Porphyromonas gingivalis, Prevotella intermedia and Capnocytophaga sputigena. The ALPase activity detected in these bacteria was almost completely inhibited in the presence of 1% sodium dodecyl sulfate (SDS). By contrast, the activity of mammalian ALPase isoenzymes was not inhibited at all even in the presence of 1% SDS. These results indicate that the ALPase assay in combination with 1% SDS can identify the origin of ALPase detected in gingival crevicular fluid as being from bacteria or from a host response. Clinical examination with adult periodontitis revealed that ALPase activity in gingival crevicular fluid from the patients consisted of a combination of SDS-sensitive and SDS-resistant activities. These findings indicate that ALPase activity detected in gingival crevicular fluid originates not only from bacteria but also from a host response.

Adult↗

Neurotrophin-3 gene polymorphism associated with schizophrenia.

The recent possible neurodevelopmental etiology of schizophrenia makes the neurotrophin-3 (NT-3) gene an interesting candidate locus. We studied the allelic distributions of dinucleotide repeat polymorphism at the NT-3 gene locus in 70 patients with schizophrenia and in 70 controls. A highly significant difference between the two groups was observed at the allele A3. Even Bonferroni's correction was used, the difference was still significant. Individuals with homozygous or heterozygous for the allele A3 had a 2.4-fold increased risk of schizophrenia. Determination of NT-3 genotype may help to identify those at greater risk of schizophrenia. Furthermore, this finding supports evidence implicating neurodevelopmental deficit in the pathogenesis of this disorder.

Adult↗

[Microbiological and clinical studies of infective endocarditis due to nutritionally variant streptococci].

We report four cases of infective endocarditis due to nutritionally variant streptococci (NVS) that occurred between 1981 and 1991. Three female and one male patients had underlying heart diseases. Causative organisms showed satellitism to staphylococci. Two strains were identified as S. adjacens and the other two were identified as S. defectivus by DNA-DNA hybridization. All strains had tolerance and one strain had resistance to benzylpenicillin (MIC 4 micrograms/ml). This penicillin-resistant strain also had tolerance to gentamicin. There was no synergism of benzylpenicillin and gentamicin against this strain by a killing curve in vitro. A 11-year-old female patient with infective endocarditis due to this strain, who had a transposition of great arteries, had large vegetations in external conduits by the Rastelli's operation. Some intensive antimicrobial chemotherapies were unsuccessful and a surgical replacement of the conduits must be done in this case. Since infective endocarditis due to NVS is not rare in Japan, NVS should be considered for the causative organisms in culture negative endocarditis.

Adult↗

Purification and characterization of periplasmic alpha-amylase from Xanthomonas campestris K-11151.

Xanthomonas campestris K-11151, isolated from soil, produced a periplasmic alpha-amylase of a new type. The enzyme was purified to homogeneity, as shown by several criteria. The purified enzyme showed almost the same activities on alpha-, beta-, and gamma-cyclodextrins, soluble starch, and amylose. Moreover, it was active on branched cyclodextrins, pullulan, and maltose but not on glycogen. Kinetic analysis showed that alpha-cyclodextrin was the best substrate among the cyclodextrins. The substrate specificity suggested that this enzyme had the combined activities of alpha-amylase, cyclodextrinase, and neopullulanase.

Amylopectin↗

A case of posttherapeutic sclerotic change of bone metastasis from renal cell carcinoma which proved histopathologically to be complete response.

A 60-year-old man with renal cell carcinoma and metastases to the right 7th rib and L2 vertebra (T2N0M1, OSS) was treated with interferon-alpha and the uracil and tegafur combination following nephrectomy. One and a half years later on bone scintigraphy, the abnormal accumulation had disappeared at the L2 vertebra and weakened in its intensity at the right 7th rib. Plain X-ray revealed that the metastatic lesion at the right 7th rib had decreased in size and had been replaced by calcification. The right 7th rib was removed surgically and step-sectioned pathological specimens revealed necrosis with no viable cancer cells.

Antineoplastic Combined Chemotherapy Protocols↗