Semi-perfusion cultures of suspension MDCK cells enable high cell concentrations and efficient influenza A virus production

Control and prevention of rapid influenza spread among humans depend on the availability of efficient and safe seasonal and pandemic vaccines, made primarily from inactivated influenza virus particles. Current influenza virus production processes rely heavily on embryonated chicken eggs or on cell culture as substrate for virus propagation. Today’s efforts towards process intensification in animal cell culture could innovate viral vaccine manufacturing using high-yield suspension cells in high cell density perfusion processes. In this work, we present a MDCK cell line adapted to grow as single cell suspension with a doubling time of less than 20 h, achieving cell concentrations over 1 × 10⁷ cells/mL in batch mode. Influenza A virus titer obtained in batch infections were 3.6 log₁₀(HAU/100 µL) for total- and 10⁹ virions/mL for infectious virus particles (TCID₅₀), respectively. In semi-perfusion mode concentrations up to 6 × 10⁷ cells/mL, accumulated virus titer of 4.5 log₁₀(HAU/100 µL) and infectious titer of almost 10¹⁰ virions/mL (TCID₅₀) were possible. This exceeds results reported previously for cell culture-based influenza virus propagation by far and suggests perfusion cultures as the preferred method in viral vaccine manufacturing.     

Dorsal suspension for Morton’s neuroma: A comparison with neurectomy

BackgroundThe purpose of this study was to investigate and compare the clinical outcomes of dorsal suspension with those of neurectomy for the treatment of Morton’s neuroma.MethodsWe conducted a retrospective study of dorsal suspension and neurectomy group. The dorsal suspension was performed by dorsal transposition of neuroma over the dorsal transverse ligament after neurolysis. The visual analog scale (VAS), the Foot and Ankle Ability Measure (FAAM), postoperative satisfaction, and complications were evaluated.ResultsBoth groups reported significant pain relief, and there were no significant differences between the groups with respect to postoperative pain. The postoperative FAAM outcomes showed no significant between-group differences. Satisfaction analysis showed ‘excellent’ and ‘good’ results in the dorsal suspension and neurectomy groups (95% and 77.7%, respectively). Complications of numbness and paresthesia reported in the dorsal suspension group (5% and 5%, respectively) were significantly fewer than those of neurectomy group (61.1% and 33.3%, respectively) (both, p < .05).ConclusionsWith its favorable results, dorsal suspension can be another operative option for the treatment of Morton’s neuroma.Level of Evidence: Level III, retrospective comparative case series.     

LC-HR-MS/MS法鉴定头孢丙烯干混悬剂中的未知杂质

目的:检测头孢丙烯干混悬剂中的未知杂质,并对其进行结构鉴定。方法:采用高效液相色谱-串联高分辨质谱法检测并鉴定头孢丙烯干混悬剂中的未知杂质。色谱柱为Thermo HyPURITYTMC18,流动相为乙腈-0.013%甲酸水溶液(梯度洗脱),检测波长为230 nm,流速为1.0 m L/min,柱温为40℃,进样量为20μL;以电喷雾离子源行正离子全扫描,扫描范围为质荷比(m/z)100~1500,喷雾电压为3.8 kV,金属毛细管温度为320℃,鞘气压力为60 Arb,辅助气压力为10 Arb,喷雾温度为280℃。结果:在该色谱条件下,杂质K的检测限为0.202μg/mL,精密度、重复性试验的RSD均小于4%。杂质K附近发现3个未知杂质,且互为异构体,离子保留时间为17.83~19.31 min,二级母离子均为m/z 436.1500[M+H]+,可能为头孢丙烯开环、脱水后的产物。结论:本方法检测出头孢丙烯干混悬剂中杂质K附近的3个未知杂质。     

尿阿尔茨海默病相关神经丝蛋白联合血浆同型半胱氨酸测定在阿尔茨海默病诊断中的研究

目的 探讨尿阿尔茨海默病（AD）相关神经丝蛋白（AD7c-NTP）含量测定联合血浆同型半胱氨酸（Hcy）在AD诊断中的价值。方法 纳入轻度阿尔茨海默病（CDR=1分）及中重度阿尔茨海默病患（CDR ≥ 2分）者各40例，并选择健康体检志愿者40例为对照组，采用酶联免疫吸附测定法（ELISA）检测尿液中AD7c-NTP含量，采用循环酶法测定血浆Hcy的含量，通过绘制ROC曲线，分析二者联合检测对AD的诊断准确性。结果 3组受试者尿AD7c-NTP含量比较，差异有统计学意义（P<0.05）；组间比较差异均有统计学意义（P<0.05）。根据ROC曲线，当尿AD7c-NTP为1.745 ng/mL时，对应的灵敏度和特异度之和最大。3组受试者血浆Hcy的含量比较，差异有统计学意义（P<0.05）；组间比较差异均有统计学意义（P<0.01）。根据ROC曲线，当血浆HCY为15.05 μmol/L时，对应的灵敏度和特异度之和最大。当二者进行联合检测时，ROC曲线下面积为0.891，大于各项单独检测。结论 AD患者尿AD7c-NTP含量及血浆HCY含量均增高；尿液AD7c-NTP含量及血浆HCY含量可作为辅助AD诊断的生物标记物；二者联合检测可提高AD诊断的准确性。     

Novel fabrication of fluorescent silk utilized in biotechnological and medical applications

Silk fibroin (SF) is a natural polymer widely used and studied for diverse applications in the biomedical field. Recently, genetically modified silks, particularly fluorescent SF fibers, were reported to have been produced from transgenic silkworms. However, they are currently limited to textile manufacturing. To expand the use of transgenic silkworms for biomedical applications, a solution form of fluorescent SF needed to be developed. Here, we describe a novel method of preparing a fluorescent SF solution and demonstrate long-term fluorescent function up to one year after subcutaneous insertion. We also show that fluorescent SF labeled p53 antibodies clearly identify HeLa cells, indicating the applicability of fluorescent SF to cancer detection and bio-imaging. Furthermore, we demonstrate the intraoperative use of fluorescent SF in an animal model to detect a small esophageal perforation (0.5 mm). This study suggests how fluorescent SF biomaterials can be applied in biotechnology and clinical medicine.     

多索茶碱联合布地奈德混悬液雾化吸入对哮喘患者炎性因子及肺功能的影响

目的探讨多索茶碱联合布地奈德混悬液雾化吸入治疗哮喘的临床效果。方法选择我院2018年5月至2019年4月收治的哮喘患者114例,随机分为两组各57例。对照组采用布地奈德混悬液雾化吸入治疗,观察组在此基础上采用多索茶碱治疗。观察两组的临床疗效、炎性因子指标(IL-4、 IFN-γ)、肺功能指标(FVC、 FEV1)及不良反应情况。结果观察组的治疗总有效率为92.98%,高于对照组的78.95%(P <0.05)。治疗后,观察组的IL-4水平低于对照组,IFN-γ、 FEV1、 FVC水平均高于对照组,差异有统计学意义(P <0.05)。两组的不良反应发生率比较,差异无统计学意义(P>0.05)。结论多索茶碱联合布地奈德混悬液雾化吸入治疗哮喘可有效改善患者的肺功能和临床症状,调节炎性因子水平,且药物副作用少。     

Thin silk fibroin films as a dried format for temperature stabilization of inactivated polio vaccine

Current inactivated polio vaccine (IPV) products are sensitive to both freezing and elevated temperatures and therefore must be shipped and stored between 2 °C and 8 °C, a requirement that imposes financial and logistical challenges for global distribution. As such, there is a critical need for a robust, thermally stable IPV to support global polio eradication and post-eradication immunization needs. Here, we present the development of air-dried thin films for temperature stabilization of IPV using the biomaterial silk fibroin. Thin-film product compositions were optimized for physical properties as well as poliovirus D-antigen recovery and were tested under accelerated and real-time stability storage conditions. Silk fibroin IPV films maintained 70% D-antigen potency after storage for nearly three years at room temperature, and greater than 50% potency for IPV-2 and IPV-3 serotypes at 45 °C for one year. The immunogenicity of silk fibroin IPV films after 2-week storage at 45 °C was assessed in Wistar rats and the stressed films generated equivalent neutralizing antibody responses to commercial vaccine for IPV-1 and IPV-2. However, the absence of IPV-3 responses warrants further investigation into the specificity of ELISA for intact IPV-3 D-antigen. By demonstrating immunogenicity post-storage, we offer the air-dried silk film format as a means to increase IPV vaccine access through innovative delivery systems such as microneedles.