130 research outputs found

    Potential Use of Folate-polyethylene glycol (PEG)-Appended Dendrimer (G3) Conjugate with alpha-Cyclodextrin as DNA Carriers to Tumor Cells

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    We previously reported that polyamidoamine STARBURST dendrimer (generation 3, G3) (dendrimer) conjugate with alpha-cyclodextrin (alpha-CyD) having an average degree of substitution of 2.4 of alpha-CyD (alpha-CDE) provided remarkable aspects as novel carriers for DNA and siRNA. To develop novel alpha-CDE derivatives with tumor cell specificity, we prepared folate-appended alpha-CDEs (Fol-alpha-CDEs) and folate-polyethylene glycol (PEG)-appended alpha-CDEs (Fol-PalphaCs) with the various degrees of substitution of folate (DSF), and evaluated in vitro and in vivo gene transfer activity, cytotoxicity, cellular association and physicochemical properties. In vitro gene transfer activity of Fol-alpha-CDEs (G3, DSF 2, 5 or 7) was lower than that of α-CDE (G3) in KB cells, folate receptor (FR)-overexpressing cancer cells. Of the three Fol-PalphaCs (G3, DSF 2, 5 or 7), Fol-PalphaC (G3, DSF 5) had the highest gene transfer activity in KB cells. The activity of Fol-PalphaC (G3, DSF 5) was significantly higher than that of alpha-CDE (G3) in KB cells, but not in A549 cells, FR-negative cells. Negligible cytotoxicity of the pDNA complex with Fol-PalphaC (G3, DSF 5) was observed in KB cells or A549 cells up to a charge ratio of 100/1 (carrier/pDNA). The cellular association of the pDNA complex with Fol-PalphaC (G3, DSF 5) could be mediated by FR on KB cells, resulting in its efficient cellular uptake. Fol-PalphaC (G3, DSF 5) had higher binding affinity with folate binding protein (FBP) than alpha-CDE (G3), although the physicochemical properties of pDNA complex with Fol-PalphaC (G3, DSF 5) were almost comparable to that with alpha-CDE (G3), although the onset charge ratio and the compaction ability of Fol-PalphaC (G3, DSF 5) were slightly different. Fol-PalphaC (G3, DSF 5) tended to show higher gene transfer activity than alpha-CDE (G3) 12 h after intratumoral administration in mice. These results suggest that Fol-PalphaC (G3, DSF 5), not Fol-alpha-CDEs, could be potentially used as a FR-overexpressing cancer cell-selective DNA carrier

    FEDSM2003-45101 STUDY ON PERFORMANCE AND INTERNAL FLOW OF CROSS FLOW WIND TURBINE

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    ABSTRACT The wind turbine has become more popular in recent years, but on the other hand, the developments of small wind-turbine have been legging behind. Because, the energy density of wind is small, since the efficiency of the main part of a wind turbine is very low. The construction costs become comparatively highpriced. Then, the main part of this subject is to show that, by collecting and sucking out more winds, a wind turbine is made to pass many winds and the new cross-flow wind turbine that increases an output coefficient is proposed. The cross-flow wind turbine has high torque and low speed characteristics and the structure are very simple. So, it can be used in a large wind velocity region. However, even if the power coefficient is high, it is about 10%. The purpose of this paper is to show how we can improve the power coefficient by applying a casing, which has a nozzle and a diffuser. This research was made to clear up fundamental characteristics of the interaction between outer flow and inner flow. Three kinds of cross-flow wind turbines were designed. The nozzle and diffuser have been designed suitable for the performance of wind turbine. The flow simulations by CFD have been carried out for various types of casings at 20 m/s with Fluent Ver5.0. All Wind tunnel experiments were performed at 20m/s. The case of casing 2, which have plate arranged near the separation point of cylinder, also experimented. The rotor that is settled in the casing 1 shows a larger power coefficient than the case without a casing. The casing of the cross-flow turbine makes a pressure difference between inflow and outflow. The pressure difference increases the mass flow rate. Therefore much more wind passes through into the cross-flow turbine. In this experiment, the power coefficient increased 1.5 times in the case with casing. A still higher output coefficient could be obtained in the case where it is shown by the casing 2

    Cultivable Anaerobic Microbiota of Infected Root Canals

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    Objective. Periapical periodontitis is an infectious and inflammatory disease of the periapical tissues caused by oral bacteria invading the root canal. In the present study, profiling of the microbiota in infected root canals was performed using anaerobic culture and molecular biological techniques for bacterial identification. Methods. Informed consent was obtained from all subjects (age ranges, 34–71 years). Nine infected root canals with periapical lesions from 7 subjects were included. Samples from infected root canals were collected, followed by anaerobic culture on CDC blood agar plates. After 7 days, colony forming units (CFU) were counted and isolated bacteria were identified by 16S rRNA gene sequencing. Results. The mean bacterial count (CFU) in root canals was (0.5 ± 1.1) × 106 (range 8.0 × 101–3.1 × 106), and anaerobic bacteria were predominant (89.8%). The predominant isolates were Olsenella (25.4%), Mogibacterium (17.7%), Pseudoramibacter (17.7%), Propionibacterium (11.9%) and Parvimonas (5.9%). Conclusion. The combination of anaerobic culture and molecular biological techniques makes it possible to analyze rapidly the microbiota in infected root canals. The overwhelming majority of the isolates from infected root canals were found to be anaerobic bacteria, suggesting that the environment in root canals is anaerobic and therefore support the growth of anaerobes

    Rapid Quantification of Bacteria in Infected Root Canals Using Fluorescence Reagents and a Membrane Filter: A Pilot Study on Its Clinical Application to the Evaluation of the Outcomes of Endodontic Treatment

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    Objective. The bacterial examination has been performed during the course of the root canal treatment. In the present pilot study, the new developed method, using fluorescence reagents and a membrane filter, was applied to the detection and quantification of bacteria in infected root canals, in order to evaluate the outcomes of the treatment. Methods. Six infected root canals with periapical lesions from 5 subjects were included. Informed consent was obtained from all subjects (age ranges, 23–79 years). Samples from infected root canals were collected at the beginning of the treatment (termed #25 First), the end of the first day of treatment (termed #55 First), and the next appointment day (termed #55 Second). Then, the bacterial count (CFU) was measured using fluorescence reagents (4′,6′-diamidino-2-phenylindole and propidium iodide) and the polycarbonate membrane filter by Bioplorer. Results. The mean ± SD of CFU in the sample of “#25 First” was (1.0 ± 1.4) × 105. As the root canal treatment progressed, the CFU decreased as 7.9 × 103 (#55 First) and 4.3 × 102 (#55 Second). Conclusion. In the present pilot study, rapid detection and quantification of bacteria in infected root canals were found to be successfully performed using fluorescence reagents and a membrane filter (Bioplorer analysis)

    Antagonist of sphingosine 1-phosphate receptor 3 reduces cold injury of rat donor hearts for transplantation

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    Cold storage is widely used to preserve an organ for transplantation; however, a long duration of cold storage negatively impacts graft function. Unfortunately, the mechanisms underlying cold exposure remain unclear. Based on the sphingosine-1-phosphate (S1P) signal involved in cold tolerance in hibernating mammals, we hypothesized that S1P signal blockage reduces damage from cold storage. We used an in vitro cold storage and rewarming model to evaluate cold injury and investigated the relationship between cold injury and S1P signal. Compounds affecting S1P receptors (S1PR) were screened for their protective effect in this model and its inhibitory effect on S1PRs was measured using the NanoLuc Binary Technology (NanoBiT)-β-arrestin recruitment assays. The effects of a potent antagonist were examined via heterotopic abdominal rat heart transplantation. The heart grafts were transplanted after 24-hour preservation and evaluated on day 7 after transplantation. Cold injury increased depending on the cold storage time and was induced by S1P. The most potent antagonist strongly suppressed cold injury consistent with the effect of S1P deprivation in vitro. In vivo, this antagonist enabled 24-hour preservation, and drastically improved the beating score, cardiac size, and serological markers. Pathological analysis revealed that it suppressed the interstitial edema, inflammatory cell infiltration, myocyte lesion, TUNEL-positive cell death, and fibrosis. In conclusion, S1PR3 antagonist reduced cold injury, extended the cold preservation time, and improved graft viability. Cold preservation strategies via S1P signaling may have clinical applications in organ preservation for transplantation and contribute to an increase in the donor pool

    Analysis of the Change in Dominant Phytoplankton Species in Unstratified Lake Oshima-Ohnuma Estimated by a Bottle Incubation Experiment

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    1996年5?7月に、渡島大沼において、優占植物プランクトンの細胞密度を測定し、さらにボトル培養実験によりそれらの成長速度を見積り、春から夏への植物プランクトン優占種変化に関わる要因を明らかにすることを試みた。4、5月にAsterionella gracillimaが優占種となったが、その成長速度は5月には比較的低く、その後、細胞密度が低下し、この主な原因は栄養塩の不足であることが示唆された。6月後半からMelosira gramulataの成長速度が増加し、優占種となった。M.gramulataは水深6mでも成長速度が高いことから、深層で生存できることと、湖が成層を形成しないことで再懸濁により有光層に存在できる状況が同種の成長に適していることが考えられた

    松前公園(北海道) のシロバナタンポポの核型

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    摘要 北海道松前町の松前公園・龍雲院にはシロバナタンポポが生育している。シロバナタンポポは本州(関東・北陸以西),四国,九州に自生し,東北以北では松前公園だけに存在することから移入されたと考えられている。シロバナタンポポには,四倍体 (2n=32)と五倍体(2n=40)があり,五倍体には核型の異なる2型 (Type I, TypeⅡ)が存在することが知られていることから,松前公園のシロバナタンポポがどのタイプかを明らかにするために,種子から育てた2個体について染色体観察を行った。その結果,松前公園のシロバナタンポポは五倍体(2n=40)であり,核型はSato et al. (2011)で報告した五倍体の2つの型の内のType Iであることが判った
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