Optimization of rs-fMRI parameters in the Seed Correlation Analysis (SCA) in DPARSF toolbox: A preliminary study

There are a number of various methods of resting-state functional magnetic resonance imaging (rs-fMRI) analysis such as independent component analysis, multivariate autoregressive models, or seed correlation analysis however their results depend on arbitrary choice of parameters. Therefore, the aim of this work was to optimize the parameters in the seed correlation analysis using the Data Processing Assistant for Resting-State fMRI (DPARSF) toolbox for rs-fMRI data received from a Siemens Magnetom Skyra 3-Tesla scanner using a whole-brain, gradient-echo echo planar sequence with a 32-channel head coil. Different ranges of the following parameters: amplitude of low-frequency fluctuation (ALFF), Gaussian kernel at FWHM and radius of spherical ROI for 109 regions were tested for 20 healthy volunteers. The highest values of functional connectivity (FC) correlations were found for ALFF 0.01–0.08, spherical ROIs with the 8-mm radius and Gaussian kernel 8 mm at FWHM in all the studied areas that is, Auditory, Sensimotor, Visual, and Default Mode Network. The dominating influence of ALFF and smoothing on values of FC correlations was noted.     

Flow cytometry evaluation of in vitro cellular necrosis and apoptosis induced by silver nanoparticles

Particles possess unique properties in the nanoscale, e.g., enhanced catalytic activity, high surface area, and light emission/absorption properties, that might result in interference with colorimetric in vitro cytotoxicity assays such as MTT, XTT or MTS. Alternatively, assays that do not use spectrophotometric detection, such as trypan blue exclusion or flow cytometry (FC) based assays, are less likely to be influenced by nanoparticle interference. The aim of this study was to evaluate FC assays to assess the cytotoxicity of three different sizes (10, 100, or 200 nm) of silver nanoparticles (AgNPs) at different mass concentrations (1, 25, or 50 ug/ml) in L-929 fibroblast cells. After 4 h and 24 h exposure, cell necrosis and apoptosis were assessed using 7-AAD and Annexin V dyes, respectively, with FC. The data indicate that cell necrosis and apoptosis in AgNP-exposed fibroblasts depends on dose, exposure time, and AgNP size. The data indicate that AgNPs produced a dose- and time-dependent decrease in cell viability; however, 10 nm AgNPs were significantly more toxic than larger-sized particles. Thus, standard FC assays can be utilized to assess apoptosis and necrosis in response to nanomaterial exposure.     

Extracellular vesicle characteristics in stored red blood cell concentrates are influenced by the method of detection

Extracellular vesicles (EVs), including microvesicles and exosomes, are small phospholipid vesicles (≤1 μm in diameter) that are present in blood products, accumulate during storage, and have a potential transfusion-related immunomodulatory role. Knowledge of EVs in stored blood products is limited due to the challenges and difficulties in detecting these heterogeneous submicron-sized vesicles. The aim of this study was to assess the impact of different approaches to characterize EVs in stored RBC products. Quantification and size-profiling of EVs in leukoreduced red cell concentrates (RCCs) were examined on day 3, 7, 21, and 42 of storage using tunable resistive plus sensing (TRPS), flow cytometer (FC), and dynamic light scatting (DLS) methods. Using the TRPS method, the concentration of EVs < 200 nm significantly increased throughout storage (p < 0.05). This change in exosome concentration was not detectable with FC or DLS due to limitations in their ability to resolve particles <200 nm and/or accurately determine EV concentration. Both the TRPS and FC demonstrate that the concentration of EVs ≥ 200 nm significantly increases in RCCs by day 42/43 compared to EVs present on day 3 (p < 0.001). As the DLS measures the average size of particles in suspension, only an increase in the zeta-average size was observed during storage. EV size and concentration in RBC products is significantly influenced by the length of storage. Overall, this study shows that combining technologies may be important to improve the characterization and study of EVs in stored RCCs.     

Poor kidney allograft survival associated with positive B cell – Only flow cytometry cross matches: A ten year single center study

The presence of donor specific antibody (DSA) to class 1 or class 2 HLA as detected respectively in T cell or B cell – only flow cytometry cross matches (FCXMs) are risk factors for renal allograft survival, though the comparative risk of these XMs has not been definitively established. Allograft survival and FCXM data in 624 microcytotoxicity (CDC) XM negative kidney transplants were evaluated. Short and long term allograft survival was significantly less in recipients with T⁻ B⁺ FCXMs (1 year, 74%, 10 year, 58%) compared to T⁺ B⁺ FCXMs (1 year, 84%, 10 year, 68%) and to T⁻ B⁻ FCXM (1 year, 90%, 10 year, 85%). Risk factors were positive FCXM, deceased donor (DD) transplantation and donor age, but not race, gender, recipient age or previous transplant. Recipients with T⁻ B⁺ and T⁺ B⁺ FCXMs were at 4.5 and 2.5 fold greater risk, respectively, of DD allograft failure compared to patients with T⁻ B⁻ FCXMs. The quantitative value of FCXM did not correlate with the duration of graft survival. We conclude that patients with DSA to class 2 HLA have a greater risk of early and late allograft failure compared to patients with DSA to class 1 HLA.     

枯草杆菌二联活菌肠溶胶囊联合莫沙必利对长航人员功能性便秘疗效观察

目的探讨长航人员功能性便秘（functional constipation，FC）的患病情况及枯草杆菌二联活菌肠溶胶囊联合莫沙必利干预性治疗的效果观察。方法采用整群分层抽样方法分别于长航前后对1 298名任务官兵进行问卷调查，调查问卷采用罗马Ⅲ标准流行病学调查问卷，有180例诊断为FC，随机分为联合治疗组（枯草杆菌二联活菌肠溶胶囊联合莫沙必利治疗，83例）和对照组（单纯用莫沙必利治疗，97例）。结果任务官兵FC患病率高达13.87%，经过药物治疗后2组便秘症状均有明显改善；同组比较观察指标较治疗前均明显改善，差异有统计学意义（P＜0.001）。组间比较，联合治疗组较对照组改善更为明显，差异有统计学意义（P＜0.001）。联合治疗组总有效率为91.57%，对照组总有效率为62.89%，2组比较差异有统计学意义（P＜0.001）。结论枯草杆菌二联活菌肠溶胶囊联合莫沙必利对长航官兵FC治疗疗效显著，值得临床推广。