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Biomedical subjects

H Miyazawa

Publications and source records attributed to H Miyazawa.

At least 37 records · Page 2Linked to original sources
PubMed2000

Continuous infusion of prostaglandin E1 via the superior mesenteric artery can prevent hepatic injury in hepatic artery interruption through passive portal oxygenation.

AIMS/BACKGROUND: Hepatic artery interruption (HAI) causes severe ischemic liver damage, especially following hepatopancreatobiliary surgery. In order to inhibit a decrease in oxygen delivery after HAI, continuous infusion of PGE1 via the superior mesenteric artery (SMA) was administered in pigs and changes in hepatic blood flow and oxygen delivery were investigated. Furthermore, its effectiveness in the prevention of liver injury was evaluated by histology and serum enzyme levels. METHODS: Animals were subjected to HAI without PGE1 infusion (control group n=6) and to continuous infusion of PGE1 (0.02 microg/kg/min) into the SMA (PGE1 group n=6). RESULTS AND CONCLUSION: PGE1 infusion via the SMA not only increased the portal blood flow but also elevated the oxygen content of the portal blood. The reduction in oxygen delivery to the liver was 50% in the control group, and only 13% in the PGE1 group. Serum aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels 24 h after HAI in the control group were 3415+/-1283 IU/L and 9839+/-2959 respectively while in the PGE1 group they were 939+/-426 IU/L and 5510+/-1545 IU/L respectively. Histological examination showed massive necrosis in the control group at 72 h but only focal liver cell necrosis in the PGE1 group. Based on this finding and the fact that this treatment can be performed easily and safely, continuous infusion of PGE1 via the SMA may be a useful intervention to prevent severe liver damage after hepatic artery interruption.

Alprostadil↗
PubMed2000

IgE antibody to fish gelatin (type I collagen) in patients with fish allergy.

BACKGROUND: Most children with anaphylaxis to measles, mumps, and rubella vaccines had shown sensitivity to bovine gelatin that was included in the vaccines. Recently, it was found that bovine type I collagen, which is the main content in the gelatin, is a major allergen in bovine gelatin allergy. Fish meat and skin also contain type I collagen. OBJECTIVE: The present study was designed to investigate IgE antibody to fish gelatin in children with fish allergy. METHODS: Serum samples were taken from patients in 3 groups: (1) 10 patients with fish allergy and specific IgE to fish meat; (2) two patients with allergies to both fish meat and bovine gelatin and specific IgE to fish meat and bovine gelatin; and (3) 15 patients with atopic dermatitis and specific IgE to fish meat. Various fish gelatins (type I collagen) were prepared from fish skin. IgE antibody to fish gelatin was analyzed by using ELISA and immunoblotting. RESULTS: Of 10 patients with fish allergy, 3 had specific IgE to fish gelatin. Of two patients with fish allergy and bovine gelatin allergy, all had specific IgE to fish gelatin. Of 15 patients with atopic dermatitis and specific IgE to fish meat, 5 had specific IgE to fish gelatin. Furthermore, IgE from pooled serum of the patients reacted with both the alpha1 and alpha2 chains of fish type I collagen in immunoblots. There is cross-reactivity among gelatins from various fishes, but there is little cross-reactivity between fish and bovine gelatins. CONCLUSION: Some fish-sensitive patients possessed IgE antibody to fish gelatin. Fish gelatin (type I collagen) might be an allergen in subjects with fish allergy.

Adolescent↗
PubMed2000

Cancer regression induced by modified CTL therapy is regulated by HLA class II and class I antigens in Japanese patients with advanced cancer.

Autologous cancer-specific bulk CTLs are unlikely to be induced by in vitro CTL generation (ivtCTLG) using peripheral blood mononuclear cells (PBMCs) of cancer patients when autologous cancer cells are used as in vitro stimulators. However, autologous cancer-specific bulk CTLs are frequently activated when allogeneic cancer cells are used as in vitro stimulators, regardless of the type of cancer cell. We have developed a cancer-specific immunotherapy called modified CTL therapy, which involves adoptive immunotherapy of autologous cancer-specific bulk CTLs after active immunization of autologous or allogeneic cancer cells screened as in vitro stimulators according to their ability to induce autologous cancer-specific CTLs (ACS. CTLs). Cancer did not regress in patients in whom ACS.CTLs were not induced by ivtCTLG using the patients' PBMCs in therapy. Cancer regression, albeit temporary, occurred solely in patients under the immunological condition that ACS.CTLs were induced by ivtCTLG using PBMCs through the therapy. The induction of ACS.CTLs by ivtCTLG using patient PBMCs in therapy was related to patients' HLA class II antigens. HLA DR8 was seen more frequently in ACS.CTL-inducible patients than in ACS.CTL-uninducible patients (P=0.051). On the contrary, HLA DQ3 was seen more frequently in ACS.CTL-uninducible patients (P=0.055). On the other hand, the success in therapy, albeit temporary, was related mainly to patients' HLA class I antigens. HLA B61 was seen more frequently in patients whose therapy proved effective than in patients whose therapy proved ineffective (P=0.018). HLA Cw7 was seen more frequently in therapy-ineffective patients (P=0.040).

Adult↗
PubMed1999

Specific IgG to gelatin in children with systemic immediate- and nonimmediate-type reactions to measles, mumps and rubella vaccines.

We examined anti-gelatin IgG in sera of children who suffered from systemic adverse reactions upon immunization with gelatin-containing live virus vaccines. In the group of 30 children who had immediate-type reactions and anti-gelatin IgE, 30 (100%) had anti-gelatin IgG and 29 (96%) had anti-gelatin IgG4. In another group of 75 children who had nonimmediate-type reactions and no anti-gelatin IgE, 22 (29%) had anti-gelatin IgG and six (8%) had IgG4. The IgG positivity well correlated with the lymphocyte proliferation assay positivity. In contrast, as a negative control, all 24 children who had no allergic reaction to live virus vaccines had no anti-gelatin IgG and IgG4. The results suggest that immune-response to gelatin may play a role in the pathogenesis of systemic nonimmediate-type reactions to the live virus vaccines.

Animals↗
PubMed1999

Structure and promoter region of the surface membrane protein HS9 gene expressed on the thymic epithelial cells.

The HS9 gene encoding a surface membrane protein is expressed in thymic epithelial cells. We have isolated the mouse HS9 gene and determined the sequence of all exons. The mouse HS9 gene is composed of 14 exons spanning approx. 31 kb. Primer extension analysis identified two transcription initiation sites 33 bp and 179 bp upstream from the ATG start codon. DNA sequence analysis of the 5'-flanking region of the first exon revealed a number of consensus binding sites for known transcription factors such as GC box, Sp1, NFkappaB, gamma-IRE. Neither typical TATA nor CCAAT boxes were found in this region. These results and the analysis of the luciferase activity showed that transcription of the HS9 gene is regulated at a TATA-less promoter.

Animals↗
PubMed1999

IgE reactivity to alpha1 and alpha2 chains of bovine type 1 collagen in children with bovine gelatin allergy.

BACKGROUND: Anaphylactic reactions to measles, mumps, and rubella vaccines, including gelatin as a stabilizer, have been reported. It had been found that most of these reactions to live vaccines are caused by the bovine gelatin included in these vaccines. Gelatin mainly includes denatured type I collagen, which consists of alpha1 and alpha2 chains. OBJECTIVE: The current study was designed to investigate the IgE reactivity to alpha1 and alpha2 chains of bovine type I collagen in gelatin-sensitive children. METHODS: Serum samples were taken from 10 children who had anaphylaxis to the vaccines and high levels of specific IgE to bovine gelatin. Bovine type I collagen was isolated from bovine skin and then separated to alpha1 and alpha2 chains by column chromatography. IgE reactivity to denatured type I collagen and its alpha1 and alpha2 chains was analyzed by immunoblotting, ELISA, and histamine release from the mast cells passive sensitized with IgE antibodies in pooled serum of the children. RESULTS: All children had specific IgE to bovine type I collagen. Furthermore, IgE antibodies in their sera reacted with the alpha;2 chain but not with the alpha1 chain. Similarly, the mast cells sensitized with pooled sera in the children showed alpha2 chain-specific histamine release but not alpha1 chain-specific histamine release. CONCLUSION: In gelatin allergy denatured bovine type I collagen is a major allergen and IgE-binding sites exist in the alpha2 chain of type I collagen.

Anaphylaxis↗
PubMed1999

A reverse-sandwich enzyme-linked immunosorbent assay for verocytotoxin 1 and 2 antibodies in human and bovine sera.

A reverse-sandwich enzyme-linked immunosorbent assay (ELISA), in which an antibody is sandwiched by antigens, was established for the titration of antibodies to verocytotoxins (VT) in human and animal sera. This assay has two advantages over a conventional indirect ELISA: (i) higher specificity and sensitivity and (ii) the ability to comparably titrate antibodies from different species. The VT1 (Shiga-like toxin 1) antibody-positive rates were 5% in 202 normal adult humans and 99% in 93 normal cattle at a dairy farm. This ELISA is most suitable for seroepidemiologic studies of infections with VT-producing Escherichia coli in humans and various animal species.

Adolescent↗
PubMed1999

Molecular architecture of the mouse DNA polymerase alpha-primase complex.

The DNA polymerase alpha-primase complex is the only enzyme that provides RNA-DNA primers for chromosomal DNA replication in eukaryotes. Mouse DNA polymerase alpha has been shown to consist of four subunits, p180, p68, p54, and p46. To characterize the domain structures and subunit requirements for the assembly of the complex, we constructed eukaryotic polycistronic cDNA expression plasmids expressing pairwise the four subunits of DNA polymerase alpha. In addition, the constructs contained an internal ribosome entry site derived from poliovirus. The constructs were transfected in different combinations with vectors expressing single subunits to allow the simultaneous expression of three or four of the subunits in cultured mammalian cells. We demonstrate that the carboxyl-terminal region of p180 (residues 1235 to 1465) is essential for its interaction with both p68 and p54-p46 by immunohistochemical analysis and coprecipitation studies with antibodies. Mutations in the putative zinc fingers present in the carboxyl terminus of p180 abolished the interaction with p68 completely, although the mutants were still capable of interacting with p54-p46. Furthermore, the amino-terminal region (residues 1 to 329) and the carboxyl-terminal region (residues 1280 to 1465) were revealed to be dispensable for DNA polymerase activity. Thus, we can divide the p180 subunit into three domains. The first is the amino-terminal domain (residues 1 to 329), which is dispensable for both polymerase activity and subunit assembly. The second is the minimal core domain (residues 330 to 1279), required for polymerase activity. The third is the carboxyl-terminal domain (residues 1280 to 1465), which is dispensable for polymerase activity but required for the interaction with the other three subunits. Taken together, these results allow us to propose the first structural model for the DNA polymerase alpha-primase complex in terms of subunit assembly, domain structure, and stepwise formation at the cellular level.

Animals↗
PubMed1998

Cerebral blood flow correlated with carotid blood flow in neurologically normal elderly with severe white matter lesions.

Previous studies of white matter signal hyperintensity (WMSH) on T2-weighted MRI (magnetic resonance imaging) have shown it to be related to decreased cerebral blood flow (CBF). However, there have been few studies on the relationship of WMSH and the internal carotid blood flow (CaBF). Doppler ultrasound sonography is widely used for evaluation of CaBF. We analyzed the relationship between CBF, CaBF, and WMSH. The subjects had not suffered cerebral ischemic episodes although they had some risk factors for stroke. They received MRI and were classified into three groups, i.e. mild, moderate, and severe WMSH. The % stenosis of the internal carotid artery (ICA) was measured with angiography. Doppler sonography was used to measure the mean bilateral CaBF. The oxygen-15 steady-state technique and PET (positron emission tomography) were used to measure CBF. There were significant correlations between the % stenosis of ICA and the ipsilateral CaBF and between the % stenosis of ICA and hemispheric CBF. There was a significant relationship between CBF and CaBF in the severe WMSH group, remaining significant after partialling out of the effects of the % stenosis. This indicated that an atherosclerotic change of the cerebral artery occurred in a way that carotid vascular resistence and cerebrovascular resistence were 'proportional'. Copyright Rapid Science Ltd

Journal Article↗
PubMed1998

The second-largest subunit of the mouse DNA polymerase alpha-primase complex facilitates both production and nuclear translocation of the catalytic subunit of DNA polymerase alpha.

DNA polymerase alpha-primase is a replication enzyme necessary for DNA replication in all eukaryotes examined so far. Mouse DNA polymerase alpha is made up of four subunits, the largest of which is the catalytic subunit with a molecular mass of 180 kDa (p180). This subunit exists as a tight complex with the second-largest subunit (p68), whose physiological role has remained unclear up until now. We set out to characterize these subunits individually or in combination by using a cDNA expression system in cultured mammalian cells. Coexpression of p68 markedly increased the protein level of p180, with the result that ectopically generated DNA polymerase activity was dramatically increased. Immunofluorescence analysis showed that while either singly expressed p180 or p68 was localized in the cytoplasm, cotransfection of both subunits resulted in colocalization in the nucleus. We identified a putative nuclear localization signal for p180 (residues 1419 to 1437) and found that interaction with p68 is essential for p180 to translocate into the nucleus. These results indicate that association of p180 with p68 is important for both protein synthesis of p180 and translocation into the nucleus, implying that p68 plays a pivotal role in the newly synthesized DNA polymerase alpha complex.

3T3 Cells↗
PubMed1998

[A case of mediastinal teratoma discovered availing of pneumonia].

A 42-year-old woman was admitted to our hospital with hemosputum and an abnormal shadow on chest X-ray. Although her hemosputum disappeared after the treatment of pneumonia, the abnormal shadow was not improved. Chest CT showed a mediastinal mass. She underwent thoracotomy and the tumor, measuring 6 x 5 x 5 cm in size, was resected. Pathological diagnosis was a mature type teratoma with direct invasion to the lung. We have to take mediastinal teratoma into consideration as one of the causes of pneumonia.

Adult↗
PubMed1997

Transgenic expression of a novel thymic epithelial cell antigen stimulates abberant development of thymocytes.

We previously reported a novel thymic stromal cell Ag, HS9, as a potent molecule participating in intrathymic T cell development. HS9 Ag is expressed on thymic stromal cells especially in the cortex but not on thymocytes. In the present study, we isolated and characterized a novel cDNA, N14, encoding HS9 Ag. Sequencing analysis of N14 cDNA has revealed it to be a novel one without any significant homology to previously reported functional molecules. COS7 cells transfected with expression vectors harboring N14 cDNA became reactive with HS9-specific mAb. Northern blot analysis and in situ hybridization revealed that several tissues that are positive for HS9 mAb expressed N14 mRNA. To examine the role of this molecule in T cell development, transgenic mice were generated. In situ hybridization and immunohistochemical study showed that the transgene was significantly overexpressed on both cortical and medullar thymic stromal cells but not on thymocytes. Flow cytometric analyses showed that the percentages of mature CD4- CD8+ or CD4+ CD8- thymocytes in transgenic mice were approximately twice and triple, respectively, those in control littermates. Moreover, substantial CD4+ CD8+ thymocytes appeared to have high levels of TCR compared with peripheral T cells. Histologic examination revealed that transgenic mice had thin cortex and relatively developed medulla. These data indicate the critical role of the N14 gene in T cell development.

Amino Acid Sequence↗
PubMed1997

Molecular cloning of the cDNA for the catalytic subunit of plant DNA polymerase alpha and its cell-cycle dependent expression.

BACKGROUND: DNA polymerase alpha has been studied in considerable detail in yeast and animals. Genetic and biochemical analyses reveal that this enzyme is composed of a heterotetramer and is necessary for replicon initiation and primer synthesis in lagging strand synthesis. In spite of the fact that modes of DNA replication in plants seem to be similar to those in other eukaryotes, very little is known about the biochemical components that participate in DNA replication of plants, including DNA polymerases. RESULTS: Using a 561-base pair DNA fragment, obtained by polymerase chain reaction amplification from a rice cDNA library as a probe, we isolated and sequenced a cDNA homologous to the cDNA for the catalytic subunit of rice DNA polymerase alpha. The encoded polypeptide has extensive homology with the catalytic subunit of DNA polymerase alpha from several species. Furthermore, when the cDNA was expressed in eukaryotic transcription/translation systems, the protein products showed DNA polymerase activity which was inhibited by a monoclonal antibody specific for DNA polymerase alpha. Using RNA gel blot analysis, we found that the levels of mRNA of the catalytic subunit of this enzyme is regulated during the cell-cycle in plant cells. CONCLUSION: This is the first report which describes the cDNA cloning of plant DNA polymerase. We conclude that the principal features of the DNA polymerase alpha catalytic subunit are conserved in plants.

Amino Acid Sequence↗
PubMed1997

[A case of anastomotic aneurysm-enteric fistula].

We successfully performed circulation reconstructive surgery and repair of a small intestine resection, primarily at an anatomical position, for perforation of a pseudoaneurysm in the small intestine, which occurred in an anastomosis site of the right leg of a Y graft of an artificial blood vessel and internal iliac artery graft on a patient, at the remote time of 18 years after she had received a Y-type artificial blood vessel. The patient's life was saved. The results suggest that it is important to make a definitive diagnosis quickly after the occurrence of symptoms and to select an appropriate surgical technique according to the findings of infection adjacent to the perforation site.

Aged↗