One-Step Detection of the 2009 Pandemic Influenza A(H1N1) Virus by the RT-SmartAmp Assay and Its Clinical Validation

<div><h3>Background</h3><p>In 2009, a pandemic (pdm) influenza A(H1N1) virus infection quickly circulated globally resulting in about 18,000 deaths around the world. In Japan, infected patients accounted for 16% of the total population. The possibility of human-to-human transmission of highly pathogenic novel influenza viruses is becoming a fear for human health and society.</p> <h3>Methodology</h3><p>To address the clinical need for rapid diagnosis, we have developed a new method, the “RT-SmartAmp assay”, to rapidly detect the 2009 pandemic influenza A(H1N1) virus from patient swab samples. The RT-SmartAmp assay comprises both reverse transcriptase (RT) and isothermal DNA amplification reactions in one step, where RNA extraction and PCR reaction are not required. We used an exciton-controlled hybridization-sensitive fluorescent primer to specifically detect the HA segment of the 2009 pdm influenza A(H1N1) virus within 40 minutes without cross-reacting with the seasonal A(H1N1), A(H3N2), or B-type (Victoria) viruses.</p> <h3>Results and Conclusions</h3><p>We evaluated the RT-SmartAmp method in clinical research carried out in Japan during a pandemic period of October 2009 to January 2010. A total of 255 swab samples were collected from outpatients with influenza-like illness at three hospitals and eleven clinics located in the Tokyo and Chiba areas in Japan. The 2009 pdm influenza A(H1N1) virus was detected by the RT-SmartAmp assay, and the detection results were subsequently compared with data of current influenza diagnostic tests (lateral flow immuno-chromatographic tests) and viral genome sequence analysis. In conclusion, by the RT-SmartAmp assay we could detect the 2009 pdm influenza A(H1N1) virus in patients' swab samples even in early stages after the initial onset of influenza symptoms. Thus, the RT-SmartAmp assay is considered to provide a simple and practical tool to rapidly detect the 2009 pdm influenza A(H1N1) virus.</p> </div

前立腺癌診断におけるPSA-ACTおよびPSA-ACT volume indexの有用性についての検討

対象は1999年7月から28ヵ月間に超音波ガイド下経直腸的前立腺生検を施行したPSA2.0～10.0ng/mlの151例で, PSA, PSA-ACT, PSAD, PSATZD, PSA-ACTD, PSA-ACTTZDを測定し, ROC解析を用いてこれらのパラメーターを検討した.系統的6ヶ所生検にて151例中36例から前立腺癌が検出された.ROC解析ではPSA-ACTTZDのAUCが最大となり, PSA-ACTTZDは有意差をもってPSA単独より有用な指標と考えられた.PSA-ACTTZDのカットオフ値を0.20ng/ml2を設定することにより, 感度90%, 特異度55%で不必要な生検を回避できる可能性が示唆されたWe examined the usefulness of prostate specific antigen alph-1-antichymotrypsin complex (PSA-ACT) and its indices for the detection of prostate cancer in patients with a prostate specific antigen (PSA) level between 2.1 and 10.0 ng/ml. Between July 1999 and October 2001, 151 patients with a PSA level between 2.1 and 10.0 ng/ml underwent a systematic biopsy under transrectal ultrasound (TRUS) guidance. The clinical values of total PSA, PSA-ACT, PSA density (PSAD), PSA-ACT density (PSA-ACTD), PSA transition zone density (PSATZD) and PSA-ACT transition zone density (PSA-ACTTZD) for the detection of prostate cancer were compared by using receiver operating characteristic (ROC) curve analysis. Of the 151 patients, 36 (23.8%) were histologically confirmed as having prostate cancer. The differences between patients with prostate cancer and benign prostatic disease were significant with respect to the PSA and PSA-ACT related parameters examined in this study. According to ROC curve analysis, the area under the curve (AUC) of PSA-ACTTZD was the greatest of all the parameters. The differences was significant between the AUC of PSA-ACTTZD and total PSA (p < 0.05). The cutoff value of PSA-ACTTZD with 0.20 ng/ml2 showed the highest sum of sensivitity (90%) and specificity (55%). Also, in 86 patients with a PSA level between 2.1 and 6.0 ng/ml, the AUC of PSA-ACTTZD was the greatest of all the parameters. Measuring the level of PSA-ACT and its indices may provide a better differentiation of prostate cancer and benign prostatic disease than total PSA alone in patients with intermediate PSA levels. PSA-ACTTZD is the most useful indicator among PSA-ACT and its volume indices