The diagnostic accuracy of high b-value diffusion- and T2-weighted imaging for the detection of prostate cancer: a meta-analysis

Purpose: This study aims to investigate the role of diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) in combination for the detection of prostate cancer, specifically assessing the role of high b-values (> 1000 s/mm2), with a systematic review and meta-analysis of the existing published data.  Methods: The electronic databases MEDLINE, EMBASE, and OpenSIGLE were searched between inception and September 1, 2017. Eligible studies were those that reported the sensitivity and specificity of DWI and T2WI for the diagnosis of prostate cancer by visual assessment using a histopathologic reference standard. The QUADAS-2 critical appraisal tool was used to assess the quality of included studies. A meta-analysis with pooling of sensitivity, specificity, likelihood, and diagnostic odds ratios was undertaken, and a summary receiver-operating characteristics (sROC) curve was constructed. Predetermined subgroup analysis was also performed.  Results: Thirty-three studies were included in the final analysis, evaluating 2949 patients. The pooled sensitivity and specificity were 0.69 (95% CI 0.68–0.69) and 0.84 (95% CI 0.83–0.85), respectively, and the sROC AUC was 0.84 (95% CI 0.81–0.87). Subgroup analysis showed significantly better sensitivity with high b-values (> 1000 s/mm2). There was high statistical heterogeneity between studies.  Conclusion: The diagnostic accuracy of combined DWI and T2WI is good with high b-values (> 1000 s/mm2) seeming to improve overall sensitivity while maintaining specificity. However, further large-scale studies specifically looking at b-value choice are required before a categorical recommendation can be made

Study of the torque of the bacterial flagellar motor using a rotating electric field.

Bacterial flagella are driven by a rotary motor that is energized by an electrochemical ion gradient across the cell membrane. In this study the torque generated by the flagellar motor was measured in tethered cells of a smooth-swimming Escherichia coli strain by using rotating electric fields to determine the relationship between the torque and speed over a wide range. By measuring the electric current applied to the sample cell and combining the data obtained at different viscosities, the torque of the flagellar motor was estimated up to 55 Hz, and also at negative rotation rates. By this method we have found that the torque of the flagellar motor linearly decreases with rotation rate from negative through positive rate of rotation. In addition, the dependence of torque upon temperature was also investigated. We showed that torque at the high speeds encountered in swimming cells had a much steeper dependence on temperature that at the low speeds encountered in tethered cells. From these results, the activation energy of the proton transfer reaction in the torque-generating unit was calculated to be about 7.0 x 10(-20) J

Local tumor progression following lipiodol-based targeted chemoembolization of hepatocellular carcinoma: a retrospective comparison of miriplatin and epirubicin

Jin Iwazawa1, Shoichi Ohue2, Naoko Hashimoto1, Takashi Mitani11Department of Radiology, Nissay Hospital, Nishiku, Osaka, 2Department of Radiology, Komatsu Hospital, Neyagawa, JapanPurpose: We aimed to compare the local control rates between miriplatin and epirubicin in lipiodol-based transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).Patients and methods: Patients who underwent targeted TACE using miriplatin (47 patients, 66 lesions) or epirubicin (64 patients, 79 lesions) as the sole therapy were enrolled. The local control rates were compared using the Kaplan–Meier estimator with the log-rank test. The patient and tumor parameters were subjected to univariate and multivariate analyses using the Cox proportional hazards model.Results: The overall local recurrence rates were 39.3% and 31.6% for the miriplatin and epirubicin groups, respectively. The local control rate was significantly higher in the epirubicin group than in the miriplatin group (P < 0.001). The local control rates at 6 months and 1 year were 70.7% and 44.8% for the miriplatin group and 83.4% and 69.2% for the epirubicin group, respectively. Multivariate analysis showed that the serum a-fetoprotein level ≥20 ng/mL (hazard ratio 2.96; P < 0.001), miriplatin usage (hazard ratio 2.53; P = 0.002), and Child-Pugh class B (hazard ratio 1.89; P = 0.042) affected local progression.Conclusion: Lipiodol-based targeted TACE using miriplatin had inferior local control rates as compared to epirubicin in patients with HCC.Keywords: chemoembolization, miriplatin, epirubicin, liver, neoplasm