NEMA NU 2-2018标准在PET/CT系统性能测试中的作用评价

目的 评价美国国家电器制造协会(National Electrical Manufactures Association, NEMA)最新标准(NU 2-2018)在正电子发射型计算机断层显像/电子计算机断层显像(positron emission tomography/computed tomography, PET/CT)设备性能检测中的作用。 方法 依据最新的NEMA NU 2-2018标准,检测西门子Biograph Vision PET/CT的空间分辨率、灵敏度、散射分数、计数丢失、随机符合、飞行时间分辨率、计数丢失率和随机符合校正精度、图像质量、衰减和散射校正精度及PET与CT配准精度指标。 结果 距视野中心1 cm处横向和轴向空间分辨率分别为3.75 mm和3.76 mm;在视野中心和轴向10 cm处的灵敏度分别为16.83 kcps/MBq和16.67 kcps/MBq;放射性浓度为27.37 kBq/mL时,最大等效噪声计数率为258.26 kcps,散射分数为38.58%;系统时间分辨率为209.82 ps;图像质量模型的对比度恢复系数范围为88.9%~96.2%,背景变异系数范围为2.05%~6.80%,平均肺插件残余误差为2.43%;计数丢失和随机符合校正最大误差为3.9%;距离床板末端 5 cm 和 100 cm处,在距视野中心Y轴1 cm处,PET和CT的配准精度分别为0.46 mm和1.07 mm,在距视野中心X轴20 cm处,PET和CT的配准精度分别为1.06 mm和1.45 mm,在距视野中心Y轴20 cm处PET和CT的配准精度分别为0.85 mm和1.15 mm。 结论 NEMA NU 2-2018标准检测条件更加接近临床,能更好地反映PET/CT设备的系统性能。     

大黄附子汤对重症急性胰腺炎小鼠肠道微皱褶细胞变化的影响

目的研究大黄附子汤对重症急性胰腺炎(SAP)小鼠肠道微皱褶细胞(M细胞)变化的影响，为大黄附子汤临床防治SAP提供理论基础。 方法选取40只健康SPF级C57BL/6J雄性小鼠，随机分为4组(每组10只)：空白对照组、大黄附子汤对照组、SAP组、大黄附子汤治疗组，其中SAP组和大黄附子汤治疗组分别以3.5 g/kg剂量腹腔注射20% L-精氨酸，空白对照组和大黄附子汤对照组注射等剂量的等渗盐水；于造模后12、24、36 h，空白对照组和SAP组给予等渗盐水0.2 mL，大黄附子汤对照组和治疗组给予大黄附子汤0.2 mL灌肠，均于造模完成48 h后处死取材，使用ELISA检测血清淀粉酶、内毒素、IL-1β及TNF-α含量，取回肠及胰腺组织行HE染色、评分，免疫组化染色检测M细胞特异性蛋白GP2并评分。 结果(1)一般情况：对照组腹腔注射后小鼠一般情况好，精神状态良好，能正常进水，四肢活动自如，行动未受影响；SAP组小鼠腹腔注射后一般情况差，精神萎靡，反应迟钝，行动迟缓，呼吸急促，拱背收腹，饮水减少。(2)SAP组淀粉酶、内毒素、IL-1β及TNF-α水平较对照组明显升高(P<0.05)；与SAP组进行对比，大黄附子汤治疗组血清淀粉酶、内毒素、IL-1β及TNF-α水平出现显著下降(P<0.05)。(3)HE染色：SAP组胰腺及回肠组织坏死严重，可见大量白细胞浸润。大黄附子汤治疗组胰腺及回肠组织轻度坏死，可见少量中性粒细胞等白细胞浸润。(4)免疫组化染色：SAP组与对照组相比GP2表达降低(P<0.05)；相较于SAP组，大黄附子汤治疗组GP2的表达水平升高(P<0.05)。 结论大黄附子汤治疗可改善作为肠道免疫应答起始的M细胞数量与功能，增强肠道免疫应答，减轻肠免疫屏障损伤，减少内毒素入血，改善SAP症状。     

Hepatotoxicity of cantharidin is associated with the altered bile acid metabolism

Cantharidin (CTD) is an effective antitumor agent. However, it exhibits significant hepatotoxicity, the mechanism of which remains unclear. In this study, biochemical and histopathological analyses complemented with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS)-based targeted metabolomic analysis of bile acids (BAs) were employed to investigate CTD-induced hepatotoxicity in rats. Sixteen male and female Sprague–Dawley rats were randomly divided into two groups: control and CTD (1.0 mg/kg) groups. Serum and liver samples were collected after 28 days of intervention. Biochemical, histopathological, and BA metabolomic analyses were performed for all samples. Further, the key biomarkers of CTD-induced hepatotoxicity were identified via multivariate and metabolic pathway analyses. In addition, metabolite–gene–enzyme network and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used to identify the signaling pathways related to CTD-induced hepatotoxicity. The results revealed significantly increased levels of biochemical indices (alanine aminotransferase, aspartate aminotransferase, and total bile acid). Histopathological analysis revealed that the hepatocytes were damaged. Further, 20 endogenous BAs were quantitated via UHPLC-MS/MS, and multivariate and metabolic pathway analyses of BAs revealed that hyocholic acid, cholic acid, and chenodeoxycholic acid were the key biomarkers of CTD-induced hepatotoxicity. Meanwhile, primary and secondary BA biosynthesis and taurine and hypotaurine metabolism were found to be associated with the mechanism by which CTD induced hepatotoxicity in rats. This study provides useful insights for research on the mechanism of CTD-induced hepatotoxicity.     

Comparison of visual outcomes after two types of mix-and-match implanted trifocal extended-depth-of-focus and trifocal intraocular lenses

Graefe's Archive for Clinical and Experimental Ophthalmology - To compare visual outcomes between two types of mix-and-match implanted trifocal extended-depth-of-focus (EDoF) and trifocal...