On-site analysis for nitrogen oxides using a newly developed portable flow injection analyzer

A new portable flow injection system was developed for on-site chemical analysis, which allows the rapid analysis of aqueous samples at sampling sites. The system comprises a newly designed double-plunger micro pump, a six-way sample injector, a reaction coil in a thermostated compartment and a detector. All of these units are connected with 0.5 mmi.d. PTFE tubing. A visible detector is assembled using a maximum wavelength of 525 nm of a light-emitting diode (LED) and 540 nm of an interference filter. The system is of the one-box type, whose dimensions are 160(W) x 160(H) x 320(D) mm, and is easy to carry to the analysis site; the weight is 8 kg. A thermostated compartment is incorporated into the proposed system in order to be used outdoors, where temperatures are changeable. The system can workwith DC 12Vas well as AC 100V; therefore, a car battery or a portable battery can be used as the power source. The analytical data can be memorized in IC cards or a note-book personal computer connected with a RS232C cable. Furthermore, software on the market can be easily used. By using the proposed system, the on-site determination of nitrogen oxides, such as nitrate and nitrite, could be carried out. Calibration graphs for nitrate and nitrite ions were linear over ranges of 0 to 1.0ppm and 0 to 100ppb ofN-NOs and N-NO2 with good precision; the sampling rate was 40~50 samples per hour. The detection limit for N-NO3 and N-NO2 was 0.5 ppb. By using the proposed system, the on-site determination of nitrate and nitrite in river water samples was carried out. The relative standard deviations of ten injections were 0.65% for nitrate and 0.15% for nitrite. Furthermore, nitrate and nitrite in biological samples as a metabolic products of nitric oxide, which have attracted a lot of attension as a messenger of diverse physiological processes, were also determined on-site with high sensitivity. By using a car battery as a power source, the proposed system worked continuously. In addition, it worked for about 5 hours continuously with a portable battery.試料採取現場での迅速な分析，すなわちオンサイト分析のための新しいポータブルフローインジェクション分析計の開発を行った・このFIA装置では，160×160誉320（mm）の箱の中にダブルプランジ ャーマイクロポンプ，試料注入語検出器及び反応恒温槽を組み入れ，重量8kgと小型・軽量化を達成し，持ち運び容易な分析計とした．特に，525nmの発光ダイオード（LED）を光源とする新規検出 器を開発することにより，小型，省電力化が可能となった．温度変化の大きな屋外での測定に耐えられるように，反応恒温槽も装備した．本FIA装置は交流100Vでのほか，直流12Vでも稼働し，カーバ ッテリーや市販のポータブルバッテリーを電源とするオンサイト分析に対応できるよう設計した．カーバッテリーを電源とした場合は長時間の連続運転が可能である．測定データはメモリーカードや RS232Cによりノート型パーソナルコンピュータへの通信も可能で，更に市販の表計算ソフトを利用してデータ処理が可能である．本装置を窒素酸化物のオンサイト分析に応用した．硝酸，亜硝酸イオン標準液による検量線は，0～1・Oppm，0～100ppbの範囲で直線性，再現性共に良好で，1時間当たり40～50試料の分析が可能であった・検出限界（5／Ⅳ＝3）は硝酸，亜硝酸態窒素として0．5ppbと通常のFIAシステムを用いる場合と全く変わらない優れた性能を有することが分かった．河川水中の硝酸，亜硝酸イオンのオンサイト分析では10回の繰り返し測定における相対標準偏差は0．65％及び0．15％と良好な結果が得られた．また，血清中の一酸化窒素（NO）の酸化代謝物としての硝酸，亜硝酸イオン濃度のオンサイト分析を行い，良好な結果を得た．本研究で検討したポータブルバッテリーでは1回の充電で5時間の連続運転が可能であった

Up-regulation of hepatitis C virus replication by human T cell leukemia virus type I-encoded Tax protein

AbstractCo-infection of hepatitis C virus (HCV) with other blood-borne pathogens such as human T cell leukemia virus (HTLV) is common in highly endemic areas. Clinical evidence showing a correlation between HTLV-I co-infection and rapid progression of HCV-associated liver disease promoted us to investigate the effect of HTLV-I-encoded Tax protein on HCV replication. Reporter assay showed that HCV replicon-encoded luciferase expression was significantly augmented by co-transfection of the Tax-expressing plasmid. Further, HCV RNA replication in replicon cells was increased either by co-culture with cells stably expressing Tax protein (Huhtax) or by culture in the presence of Huhtax-conditioned medium, indicating that Tax could also modulate HCV replication of adjacent cells in a paracrine manner. Additionally, HCV replication in Huhtax exhibited a reduced responsiveness to interferon-α-induced antiviral activity. This study demonstrates the facilitation of HCV replication by Tax protein, which may partially account for severer clinical consequences of HCV-related disease in HCV/HTLV co-infected individuals

Urinary ACE2 in pediatric IgA nephropathy

Background : Our previous studies demonstrated that the intrarenal renin-angiotensin system (RAS) status was activated in pediatric patients with chronic glomerulonephritis. In the present study, we tested the hypothesis that angiotensin-converting enzyme 2 (ACE2) expression in the kidney is associated with the development of pediatric IgA nephropathy. Methods : We analyzed urinary ACE2 levels and ACE2 expression in the kidney tissues of pediatric patients with IgA nephropathy treated with RAS blockade. Paired tests were used to analyze changes from the first to the second biopsy. Results : Urinary ACE2 levels were significantly decreased after RAS blockade treatment, accompanied by decreased ACE2 expression levels in kidney tissues, urinary protein levels and mesangial hypercellularity scores. Urinary ACE2 levels at the first biopsy were positively correlated with the ACE2 expression levels. Conclusions : These data suggest that urinary ACE2 is associated with ACE2 expression in the diseased kidney, which correlates with the pathogenesis of IgA nephropathy in pediatric patients

Potential role of vacuolar H+–adenosine triphosphatase in neointimal formation in cultured human saphenous vein

AbstractObjective: Vacuolar H+–adenosine triphosphatase plays a pivotal role in pH regulation and molecular transport across the vacuolar membranes and is involved in cell proliferation and transformation. In the present study, possible involvement of vacuolar H+–adenosine triphosphatase in neointimal formation was investigated in an organ culture model of human saphenous vein. Methods and results: Cultured saphenous vein segments developed neointimal formation and marked thickening of the media within 14 days. Neointimal formation and medial thickening were completely inhibited by 10 nmol/L bafilomycin A1, a selective inhibitor of vacuolar H+-adenosine triphosphatase, although structurally related macrolide antibiotics FK-506 and erythromycin were without an effect. The neointimal cells were positive for α-smooth muscle actin and vimentin but negative for desmin, indicative of myofibroblasts. The emergence of myofibroblasts was inhibited, and endothelial cells were preserved in the saphenous vein segments treated with bafilomycin A1. Uptake of bromodeoxyuridine, a proliferation marker, by myofibroblasts was abrogated in the saphenous vein segments treated with 10 nmol/L bafilomycin A1. Detection of apoptotic cells by terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling concomitant with identification of desmin-expressing smooth muscle cells demonstrated that neointimal myofibroblasts, but not medial smooth muscle cells, that expressed desmin underwent apoptosis by treatment with bafilomycin A1. Conclusions: These results suggest that vacuolar H+–adenosine triphosphatase may be involved in myofibroblast growth that contributes to neointimal formation and medial thickening in cultured human saphenous vein. Increased sensitivity of myofibroblasts, but not endothelial cells, and differentiated smooth muscle cells to bafilomycin A1 may have potential therapeutic implications in the treatment for vein graft disease. (J Thorac Cardiovasc Surg 2000;119:998-1007

A Phthalimide Derivative That Inhibits Centrosomal Clustering Is Effective on Multiple Myeloma

Despite the introduction of newly developed drugs such as lenalidomide and bortezomib, patients with multiple myeloma are still difficult to treat and have a poor prognosis. In order to find novel drugs that are effective for multiple myeloma, we tested the antitumor activity of 29 phthalimide derivatives against several multiple myeloma cell lines. Among these derivatives, 2-(2,6-diisopropylphenyl)-5-amino-1H-isoindole-1,3- dione (TC11) was found to be a potent inhibitor of tumor cell proliferation and an inducer of apoptosis via activation of caspase-3, 8 and 9. This compound also showed in vivo activity against multiple myeloma cell line KMS34 tumor xenografts in ICR/SCID mice. By means of mRNA display selection on a microfluidic chip, the target protein of TC11 was identified as nucleophosmin 1 (NPM). Binding of TC11 and NPM monomer was confirmed by surface plasmon resonance. Immunofluorescence and NPM knockdown studies in HeLa cells suggested that TC11 inhibits centrosomal clustering by inhibiting the centrosomal-regulatory function of NPM, thereby inducing multipolar mitotic cells, which undergo apoptosis. NPM may become a novel target for development of antitumor drugs active against multiple myeloma