Acanthamoeba containing endosymbiotic chlamydia isolated from hospital environments and its potential role in inflammatory exacerbation

Background: Environmental chlamydiae belonging to the Parachlamydiaceae are obligate intracellular bacteria that infect Acanthamoeba, a free-living amoeba, and are a risk for hospital-acquired pneumonia. However, whether amoebae harboring environmental chlamydiae actually survive in hospital environments is unknown. We therefore isolated living amoebae with symbiotic chlamydiae from hospital environments. Results: One hundred smear samples were collected from Hokkaido University Hospital, Sapporo, Japan; 50 in winter (February to March, 2012) and 50 in summer (August, 2012), and used for the study. Acanthamoebae were isolated from the smear samples, and endosymbiotic chlamydial traits were assessed by infectivity, cytokine induction, and draft genomic analysis. From these, 23 amoebae were enriched on agar plates spread with heatkilled Escherichia coli. Amoeba prevalence was greater in the summer-collected samples (15/30, 50%) than those of the winter season (8/30, 26.7%), possibly indicating a seasonal variation (p = 0.096). Morphological assessment of cysts revealed 21 amoebae (21/23, 91%) to be Acanthamoeba, and cultures in PYG medium were established for 11 of these amoebae. Three amoebae contained environmental chlamydiae; however, only one amoeba (Acanthamoeba T4) with an environmental chlamydia (Protochlamydia W-9) was shown the infectious ability to Acanthamoeba C3 (reference amoebae). While Protochlamydia W-9 could infect C3 amoeba, it failed to replicate in immortal human epithelial, although exposure of HEp-2 cells to living bacteria induced the proinflammatory cytokine, IL-8. Comparative genome analysis with KEGG revealed similar genomic features compared with other Protochlamydia genomes (UWE25 and R18), except for a lack of genes encoding the type IV secretion system. Interestingly, resistance genes associated with several antibiotics and toxic compounds were dentified. Conclusion: These findings are the first demonstration of the distribution in a hospital of a living Acanthamoeba carrying an endosymbiotic chlamydial pathogen

Detection of significant antiviral drug effects on COVID-19 with reasonable sample sizes in randomized controlled trials : a modeling study

Background Development of an effective antiviral drug for Coronavirus Disease 2019 (COVID-19) is a global health priority. Although several candidate drugs have been identified through in vitro and in vivo models, consistent and compelling evidence from clinical studies is limited. The lack of evidence from clinical trials may stem in part from the imperfect design of the trials. We investigated how clinical trials for antivirals need to be designed, especially focusing on the sample size in randomized controlled trials. Methods and findings A modeling study was conducted to help understand the reasons behind inconsistent clinical trial findings and to design better clinical trials. We first analyzed longitudinal viral load data for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) without antiviral treatment by use of a within-host virus dynamics model. The fitted viral load was categorized into 3 different groups by a clustering approach. Comparison of the estimated parameters showed that the 3 distinct groups were characterized by different virus decay rates (p-value < 0.001). The mean decay rates were 1.17 d−1 (95% CI: 1.06 to 1.27 d−1), 0.777 d−1 (0.716 to 0.838 d−1), and 0.450 d−1 (0.378 to 0.522 d−1) for the 3 groups, respectively. Such heterogeneity in virus dynamics could be a confounding variable if it is associated with treatment allocation in compassionate use programs (i.e., observational studies). Subsequently, we mimicked randomized controlled trials of antivirals by simulation. An antiviral effect causing a 95% to 99% reduction in viral replication was added to the model. To be realistic, we assumed that randomization and treatment are initiated with some time lag after symptom onset. Using the duration of virus shedding as an outcome, the sample size to detect a statistically significant mean difference between the treatment and placebo groups (1:1 allocation) was 13,603 and 11,670 (when the antiviral effect was 95% and 99%, respectively) per group if all patients are enrolled regardless of timing of randomization. The sample size was reduced to 584 and 458 (when the antiviral effect was 95% and 99%, respectively) if only patients who are treated within 1 day of symptom onset are enrolled. We confirmed the sample size was similarly reduced when using cumulative viral load in log scale as an outcome. We used a conventional virus dynamics model, which may not fully reflect the detailed mechanisms of viral dynamics of SARS-CoV-2. The model needs to be calibrated in terms of both parameter settings and model structure, which would yield more reliable sample size calculation. Conclusions In this study, we found that estimated association in observational studies can be biased due to large heterogeneity in viral dynamics among infected individuals, and statistically significant effect in randomized controlled trials may be difficult to be detected due to small sample size. The sample size can be dramatically reduced by recruiting patients immediately after developing symptoms. We believe this is the first study investigated the study design of clinical trials for antiviral treatment using the viral dynamics model

Lattice Design Of Jhf Synchrotrons

Several kinds of lattice structures have been designed and examined for the JHF synchrotorons. The high(or imaginary) fl t lattice has been used as the 50 GeV main ring to avoid beam loss at the transition crossing. We have studied the feasibility to apply this scheme to the 3 GeV booster as a flexible momentum compaction lattice. These rings have wide tunablilities and flexibilities of the linear optics. The possibility of increasing the extraction energy of the booster to 6 GeV has been investigated. 1 INTRODUCTION The Japan Hadron Facility(JHF) consists of the 50 GeV main ring, the 3 GeV booster and the 200 MeV linac. Because the beam intensity of the main ring is extremely high (2\Theta10 14 ppp), a low beam loss is required. In order to avoid beam loss at the transition crossing, we have employed the imaginary fl t lattice which does not have a transition energy. The 3 GeV booster is a rapid cycle synchrotron of which repetition rate is 25 Hz. It will be constructed in the ex..

NUMERICAL AND EXPERIMENTAL STUDY OF COOLING-STACKING INJECTION IN HIMAC SYNCHROTRON

The cooling-stacking injection at the HIMAC synchrotron was used to increase the intensity of Ar18+ ion beam. The beam stacking was realized in a horizontal freephase-space, which was created by the HIMAC electron cooler. The stack intensity of (1.5-2.5) / 109 ppp was accumulated at an injection intensity of (0.3-1.0)/109.The lifetime of stack ions is determined by vacuum pressure. The new injected ions were slowly lost at multiple scattering on residual gas atoms at diffusion heating in the vertical direction caused by the acceptance of 30 pi mmmrad and a reduction of cooling force at large betatron amplitudes. The results of numerical simulations and experimental study of cooling-stacking injection on the HIMAC synchrotron are presented

A mathematical model for dynamics of soluble form of DNAM-1 as a biomarker for graft-versus-host disease.

DNAM-1 (CD226) is an activating immunoreceptor expressed on T cells and NK cells and involved in the pathogenesis of acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We previously reported that a soluble form of DNAM-1 (sDNAM-1) is generated by shedding from activated T cells. Moreover, higher serum levels of sDNAM-1 in patients before allo-HSCT is a predictive biomarker for the development of aGVHD based on the retrospective univariate and multivariate analyses in allo-HSCT patients. However, it remains unclear how the serum levels of sDNAM-1 are regulated after allo-HSCT and whether they are associated with the development of aGVHD. Here, we constructed a mathematical model to assess the dynamics of sDNAM-1 after allo-HSCT by assuming that there are three types of sDNAM-1 (the first and the second were from alloreactive and non-alloreactive donor lymphocytes, respectively, and the third from recipient lymphocytes). Our mathematical model fitted well to the data set of sDNAM-1 in patients (n = 67) who had undergone allo-HSCT and suggest that the high proportion of the first type of sDNAM-1 to the total of the first and second types is associated with high risk of the development of severe aGVHD. Thus, sDNAM-1 after allo-HSCT can be a biomarker for the development of aGVHD

超低速重イオン用分割同軸型ＲＦＱの研究

　近年不安定原子核のビームを使った研究が急速に発展しつつある｡不安定原子核のビームは､中性子過剰核､超重核など極限領域の核物理や､宇宙に於ける元素合成過程の研究など､他の手段では実現できない核物理､天体核物理を開拓できる他､物性物理､放射化学､原子物理など様々な分野でも新しい研究領域を広げることが出来る｡これに伴い､これらの短寿命核を加速するための加速器への関心が急速に高まってきた｡しかし高エネルギー粒子による核破砕反応で生成され､イオン化された短寿命核は､多くの場合荷電数対質量数比εが数十分の一であり､中には1/100以下という非常に小さいものもある｡このような場合イオン源から得られるビームエネルギーは核子当り1keV程度となり､この時の速度は光速の0.1%程度という非常に低い値となる｡このような超低速重イオンを加速する場合には加速器の初段に特別の前段加速器が必要になる｡高周波四重極電場を用いてビームの加速と集束を同時に行えるRFQ線形加速器(以下RFQと略す)は､このような目的に最適であると考えられている｡　わが国においては大型ハドロン計画において不安定核ビームファシリティの建設が構想されており､これに伴い入射エネルギーが1keV/u､εが1/60以上の超低速重イオンを加速できるRFQの開発研究が筆者らによって行われている｡筆者の研究目的は超低速重イオンの加速を行えるRFQの実用化を図ることである｡　筆者らはε=1/30の超低速重イオンを実際に加速できる実機モデルの研究開発を行っている｡この実機モデルは内直径90cm､長さ70cmのモジュール空胴を三台つなぎ合わせた全長2.1mのマルチモジュール型共振空胴であり､運転周波数は25.5MHz､εが1/30以上のィオンを1keV/uから45.4keV/uまで加速出来るものである｡　本研究の成果は､高周波テスト及び加速テストの結果から大幅な設計の変更をせずにこのSCRFQの実用化が可能であるという結論を得た事である｡以下に本研究の成果について述べる｡　　1.分割同軸型構造を採用することにより､共振周波数のわりに空胴径を　　　小さくする事が出来た｡　　2.四電極にはヴェインを採用している｡ヴェインとは軸方向に周期的に　　　波形をつけた板状電極であり､これを用いるとビームアパーチャー内　　　の電場分布をKapchinskij-Teplyakovの電位関数の低次の項だけで正　　　確に表すことが出来る｡SCRFQにヴェインを採用するのは筆者らが　　　初めてである｡　　3.この加速器は実機の実用化を実現するために作られたモデルである　　　ので､電極及び加速空胴の設計手法､加速器の高周波試験及び加速試　　　験の結果から実機の評価が行えるように設計製作を行なった｡また､　　　ステムフランジを考案することによって､内導体と外導体で独立に加　　　工組立が行え､かつ精度よい電極の組み込みが行える構造(マルチモ　　　ジュール構造)の開発に成功した｡この構造の採用により内導体の設　　　定精度を大幅に向上させることが出来た｡　　4.対向電極には結合リングが取り付けてある｡結合リングの役割は対向　　　電極を等電位に保ち電場の二重極成分の混入を防ぐと共に､ヴェイン　　　の位置精度を上げる事である｡　　　結合リングを取り付けて､空胴への入力電力と共振周波数の変化量　　　との関係を調べたところ､入力電力85kW(デューティー10%)で共　　　振周波数の上昇は130kHzであった｡一方､結合リングを分割して同　　　様の測定を行ったところ､入力電力80kW(デューティー20%)で周波　　　数の上昇は53kHzであった｡更に､結合リングの有無による加速性　　　能の変化を出射エミッタンスと透過効率の測定結果から調べたが､両　　　者の間に変化は見られなかった｡このことからSCRFQでは結合リン　　　グは必要ない事が分かった｡　　5.冷却系の設計は+一本の冷却管を用いて行なった｡管の半径や流量は　　　電極の熱による歪みで電場分布が1%以上ずれない事を条件として決　　　定した｡高周波結合器はループカップラーを用いる｡高電力に対応す　　　るため､ループは銅パイプで作られており､水冷却を行う｡　　　結合リングが取り付けてある状態での冷却水の温度上昇は､入力電　　　力85kW(デューティー10%)で平均0.5゜Cであった｡一方､結合リ　　　ングを分割して同様の測定を行ったところ､入力電力80kW(デュー　　　ティー20%)で平均0.9゜Cであった｡このことから結合リングを外せ　　　ば､デューティー20%位までであれば空胴をフルパワーで運転しても､　　　現在の冷却系でも空胴の冷却能力は十分であることが分かった｡　　6.共振周波数の調整はステムとフランジによって囲まれた空間(窓)に生　　　じるインダクタンス(ステムインダクタンス)を調整する事によって　　　行う｡空胴の周波数が25.45MHzとなる様にインダクタンス(窓の面　　　積)を調整し､最終的にブロックチューナーで周波数を25.5MHzに　　　合わせた｡この時の無負荷のQ値は計算値の約80%であった｡　　7.ヴェイン間及びビーム軸近傍の電場分布の測定は誘電体を用いた摂　　　動法によって行なわれた｡測定の結果､ヴェイン間の電場の四回対称　　　性からのずれは目標値である±1%より良く､ヴェイン全域にわたって　　　±0.67%以内であった｡またビーム軸近傍でのビーム軸に沿った電場　　　強度分布はKapchinskii-Teplyakovの電位関数に､設計時のセルパラ　　　メータを代入した計算によって定性的に説明できた｡　　8.高電力試験ではまずモニターループの較正を行い､共振抵抗の測定､　　　Q値の測定を行いこれらの数値を使って求めたヴェイン間電圧と入力　　　電力の関係がほぼ一致していることを確認した｡また､高電力運転時　　　のエージング時間と放電の頻度の関係について調べた｡　　9.ビーム輸送系を入射側と出射側についてそれぞれ設計した｡またビー　　　ムの輸送に必要な入射側のアインツェルレンズ､イオンセパレータ､　　　静電ステアラー､出射側のQダブレットの設計製作をした｡またビー　　　ムの性質及び加速性能を評価するためのビームモニターとしてファラ　　　デーカップ､エミッタンスモニター､ビームスリットの設計製作をした｡　　10.εが1/28のN+ 2を1keV/uから設計値(45.4keV/u)まで加速する事に　　　成功した｡1keV/u以下の超低速重イオンの加速に成功した例は､世　　　界的に見てもほとんどない｡　　11.加速テストでは入射及び出射エミッタンス､ビームの透過効率､エネ　　　ルギースペクトルの測定をN+ 2(ε=1/28)､N+(ε=1/14)､Ne+(ε=1/20)　　　についてそれぞれ行なった｡　　12.ヴェインの加工を二次元で行った｡二次元加工したヴェインの影響は　　　透過効率に顕著に現れ､80%以上の透過効率を得るにはヴェイン間電　　　圧を設計値より30%上げなければならなかった｡二次元加工したヴェ　　　インの影響を考慮した計算コード(Modified PARMTEQ)で行った透　　　過効率の計算値は計算コードPARMTEQによる計算値よりも測定値　　　に近い事が分かった｡二次元で加工されたヴェインを使った加速器の　　　加速性能を実験的に評価したのは筆者らが初めてである