74 research outputs found

    Critical Point Mutations for Hepatitis C Virus NS3 Proteinase

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    AbstractThe hepatitis C virus NS3 proteinase plays an essential role in processing of HCV nonstructural precursor polyprotein. To detect its processing activity, we developed a simpletrans-cleavage assay. Two recombinant plasmids expressing the NS3 proteinase region and a chimeric substrate polyprotein containing the NS5A/5B cleavage site between maltose binding protein and protein A were co-introduced intoEscherichia colicells. The proteinase processed the substrate at the single site during their polyprotein expression. Deletion analysis indicated that the functionally minimal domain of the NS3 proteinase was composed of 146 amino acids, 1059 to 1204. We isolated several cDNA clones encoding the functional domain of the NS3 proteinase from the sera of patients chronically infected with HCV and determined their proteinase activity by thistrans-cleavage assay. Both active and inactive clones existed in the same patients. Comparative sequence analyses of these clones suggested that certain point mutations seemed to be related to the loss of proteolytic activity. This was confirmed by back mutation experiments. Among the critical mutations, Pro-1168 to Thr and Arg-1135 to Gly were intriguing. These amino acids, which are situated near the oxyanion hole, seem to be essential for maintaining the conformation of the active center of the NS3 proteinase

    ω-Carboxyl variants of 7-ketocholesteryl esters are ligands for β2-glycoprotein I and mediate antibody-dependent uptake of oxidized LDL by macrophages

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    beta(2)-Glycoprotein I (beta(2)-GPI) is a major antigen for anticardiolipin antibodies (aCL, Abs) present in patients with antiphospholipid syndrome. We recently reported that beta(2)-GPI specifically binds to oxidized LDL (oxLDL) and that the beta(2)-GPI's major ligand, oxLig-1 is 7-ketocholesteryl-9-carboxynonanoate (Kobayashi, K, E. Matsuura, Q. P. Liu, J. Furukawa, K. Kaihara, J. Inagaki, T. Atsumi, N. Sakairi, T. Yasuda, D. R. Welker, and T. Koike. 2001. A specific ligand for beta(2)-glycoprotein I mediates autoantibody-dependent uptake of oxidized low density lipoprotein by macrophages. J Lipid Res. 42: 697-709). In the present study, we demonstrate that omega-carboxylated 7-ketocholesteryl esters are critical for beta(2)-GPI binding. A positive ion mass spectrum of a novel ligand, designated oxLig-2, showed fragmented ions at m/z 383 and 441 in the presence of acetone, which share features of oxLig-1 and 7-ketocholesterol. In the negative ion mode, ions at m/z 627, 625, and 243 were observed. oxLig-2 was most likely 7-ketocholesteryl-12-carboxy (keto) dodecanoate. These ligands were recognized by beta(2)-GPI. Liposome binding to macrophages was significantly increased depending on the ligand's concentration, in the presence of beta(2)-GPI and an anti-beta(2)-GPI Ab. Synthesized variant, 7-ketocholesteryl-13-carboxytxidecanoate (13-COOH-7KC), also showed a significant interaction with beta(2)-GPI and a similar binding profile with macrophages. Methylation of the carboxyl function diminished all of the specific ligand interactions with beta(2)-GPI. Thus, omega-carboxyl variants of 7-ketocholesteryl esters can mediate anti-beta(2)-GPI Ab-dependent uptake of oxLDL by macrophages, and autoimmune atherogenesis linked to beta(2)-GPI interaction with oxLDL

    Characterization of a Murine Anti-laminin-1 Monoclonal Antibody (AK8) Produced by Immunization with Mouse-derived Laminin-1

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    Laminin-1 is a structural glycoprotein that forms an integral part of the scaffolding of basement membranes, and plays an important role during embryonic development. We have recently demonstrated a significant association between anti-laminin-1 antibodies (Abs) and reproductive failure, such as recurrent spontaneous abortions and infertility-associated endometriosis in both human and mouse studies. In the present study, we established an IgM (μ,κ) monoclonal anti-laminin-1 Ab (AK8) by immunizing mice with mouse Engelbreth-Holm-Swarm sarcoma (EHS)-derived laminin-α1. The AK8 monoclonal antibody (mAb) reacted with particular peptide sequences from the globular G domain of mouse laminin-α1 chain of using ELISA and Western blot techniques. The peptide tertiary structure of the epitope recognized by AK8 mAb was predicted using eight synthesized domain peptide sequences and three consensus sequences obtained by phage displayed random peptide library. Basement membranes of endometrium of pregnant mice and humans were immunostained with AK8 mAb. Thus, AK8 mAb recognized a common structure present in the G domain of the laminin-1 chain in both mice and humans. The passive immunization of mice with AK8 mAb may represent a suitable animal model for anti-laminin-1 Ab-mediated reproductive failure

    Novel ELN mutation in a Japanese family with a severe form of supravalvular aortic stenosis

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    BackgroundSupravalvular aortic stenosis (SVAS) is one of the congenital cardiovascular diseases characterized by stenosis of the aorta. The stenotic lesions occur anywhere above the aortic valve in the aortic tree as well as pulmonary arteries and eventually leads to circulatory failure. The disease gene has been identified on the elastin gene (ELN) and two types of SVAS have been categorized; a familial type and an isolated type with the de novo mutation.MethodsFluorescent In situ hybridization (FISH) analysis and gene sequencing were performed in a two‐generation family in which severe form of SVAS was diagnosed.ResultsNone of the patients tested showed microdeletion of ELN, LIMK1, and D7S613. A novel nonsense mutation of ELN (c.160G>T (p.(Gly54*)), RNA not analyzed) was found in exon 3 in three members; two of them died suddenly due to rapid progression of SVAS with possible arrhythmia in early infancy. A point mutation in the 5’ untranslated region, which was previously suggested to be associated with SVAS, did not co‐segregate with the SVAS phenotype and found to be SNPs.ConclusionOur report shows a broad spectrum of clinical features in family members sharing the identical mutations, suggesting a potential contribution of modifier gene(s) or interactions with environmental factors

    Oyygen uptake of adriamycin resistant cells of Ehrlich ascites tumor

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    エールリッヒ腹水癌細胞を用いアドリアマイシンに対する耐性細胞(ADR耐性細胞)を樹立した。電子顕微鏡を用い撮影写真から細胞質当たりのミトコンドリア(MT)の割合を面積比で求めた。親株に比較して1μg/ml ADR耐性細胞では1.32倍、10μg/ml ADR耐性細胞では1.47倍であった。これらの細胞の呼吸を測定した。耐性細胞の内発呼吸は親株に比較して増加していた。1μg/ml ADR耐性細胞では1.45倍、10μg/ml ADR耐性細胞では1.49倍であり、MTの増加量とほぼ同じ割合であった。これらのことから、細胞が耐性になるとエネルギー消費が高まるために細胞内MTが増加し、その結果呼吸(酸素消費)が増加することが推察された。Adriamycin-resistant cells of Ehrlich ascites tumor cells were established in our laboratory. Using electron microscope, the area of mitochondria (MT) per cytoplasm of ADR-resistant cells were measured with planimeter. The values of wild-type cells, 1μg/ml ADR-resistant cells and 10μg/ml ADR-resistant cells were 39.3, 51.8 and 57.7 μ(2) per 1,000 μ(2) of cytoplasm, respectively. Oxygen consumption of 1 μg/ml ADR-resistant cells and 10 μg/ml ADR-resistant cells were 1.45-fold and 1.49-fold compared to that of wild-type cells, respectively. These results indicate that ADR-resistant cells require more energy to work efflux pump than wild-type cells

    Reliability and Validity of the Nursing Student Competency Assessment Instrument and Related Factors

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    The purpose of this study was to confirm the reliability and validity of the competency assessment index of nursing students and to identify the factors associated with competency. An anonymous self-administered questionnaire survey was conducted on nursing students enrolled from April 2021 to March 2022. Principal component analysis and Cronbach’s alpha coefficient were used to examine the reliability and validity of the competency factor structure. Multiple regression analysis was used to analyze related factors. As a result, the reliability and validity of the factor structure of competency were statistically clarified. As related factors of competency, “grade level” and “thinking that learning in university education gives students confidence” and “cognitive regulation strategies” were identified. In the analysis by competency sub-factors, other than grade level,[ relationship building] was affected by “being immersed in university education,” [ethical care] and [cooperation and collaboration] by “thinking that learning in university education gives students confidence”, and[ health problem-solving] and[ professional development] by “cognitive regulation strategies”. The importance of recommending experiential education in clinical practice, strengthening self-regulated learning strategies, and education to increase students’ self-confidence were suggested. The results of this study contribute to the reconstruction of education in which competencies are shared with students

    The association of C-reactive protein with an oxidative metabolite of LDL and its implication in atherosclerosis

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    C-reactive protein (CRP) is one of the strongest independent predictors of cardiovascular disease. We have previously reported that oxidized LDL (oxLDL) interacts with beta 2-glycoprotein I (beta 2GPI), implicating oxLDL/P2GPI complexes as putative autoantigens in autoimmune-mediated atherosclerotic vascular disease. In this study, we investigated the interaction of CRP with oxLDL/beta 2GPI complexes and its association with atherosclerosis in patients with diabetes mellitus (DM). CRP/oxLDL/R2GPI complexes were predominantly found in sera of DM patients with atherosclerosis. In contrast, noncomplexed CRP isoforms were present in sera of patients with acute/chronic inflammation, i.e., various pyrogenic diseases, rheumatoid arthritis (RA), and DM. Immunohistochemistry staining colocalized CRP and beta 2GPI together with oxLDL in carotid artery plaques but not in synovial tissue from RA patients, strongly suggesting that complex formation occurs during the development of adierosclerosis. Serum levels of CRP correlated with soluble forms of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, and oxLDL/beta 2GPI complexes correlated with total cholesterol and hemoglobin Al c. Thus, the generation of CRP/oxLDL/beta 2GPI complexes seems to be associated with arterial inflammation, hyperglycemia, and hypercholesterolemia. CRP/oxLDL/R2GPI complexes can be distinguished from pyrogenic noncomplexed CRP isoforms and may represent a more specific and predictive marker for atherosclerosis

    Current status of pan-Arctic terrestrial ecosystem and its possible changes

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    第6回極域科学シンポジウム特別セッション:[S] 北極温暖化とその影響 ―GRENE 北極気候変動プロジェクトと新しい方向性―11月18日(水) 国立極地研究所 2階 大会議

    シロリムス ヨウシュツ ステント リュウチ 7ネンゴ ニ ハジメテ ゾウエイザイ ステント シュウイ シミダシゾウ オ ミトメタ イチレイ

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    A 74-year-old man who had a history of percutaneous coronary intervention [left anterior descending coronary artery #6‐7, sirolimus eluting stent (SES) (Cypher stent,3.0×18mm), left circumflex coronary artery #13, SES (Cypher stent, 2.5×23mm)] for angina pectoris experienced chest pain on effort after seven years from the coronary intervention. He was introduced to our hospital and coronary angiography revealed late acquired peri-stent contrast staining (PSS), which is defined as an angiographical finding of contrast medium stain outside the stent being >20% of the stent diameter, in the SES of the left anterior descending artery. Drug-eluting stent (DES) significantly inhibits neointimal proliferation, thereby significantly reducing in-stent restenosis. However, the risk of very late stent thrombosis has become a major problem after the DES implantation against the bare-metal stent implantation. PSS has been reported that PSS after SES implantation could predict late stent thrombosis and incomplete stent apposition of the lesion with PSS. In this case, PSS was pointed out for the first time in seven years after SES implantation nevertheless it did not be pointed out in three years. The mechanism and prognosis of PSS is unclear. But, we found the increase in local coagulation at the coronary artery in this case and the degree of prothrombin fragment F1+2, one of the coagulation marker, was greater in seven years after SES implantation than in three years. We thought these findings might reflect that PSS after SES implantation was associated with very late stent thrombosis. So we started the dual antiplatelet therapy for the prevention of stent thrombosis. Careful long-term observation might be recommended in patients with late acquired PSS and elevated local coagulation response following SES implantation
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