The Effect of Ambient Illumination on Handheld Display Image Quality

Handheld devices such as smartphones and tablets are becoming useful in the medical field, as they allow physicians, radiologists, and researchers to analyze images with the benefit of mobile accessibility. However, for handheld devices to be effective, the display must be able to perform well in a wide range of ambient illumination conditions. We conducted visual experiments to quantify user performance for testing the image quality of two current-generation devices in different ambient illumination conditions while measuring ambient light levels with a real-time illuminance meter. We found and quantified that due to the high reflectivity of handheld devices, performance deteriorates as the user moves from dark areas into environments of greater ambient illumination. The quantitative analysis suggests that differences in display reflection coefficients do not affect the low illumination performance of the device but rather the performance at higher levels of illumination.     

Potential lack of “standardized” processing techniques for production of allogeneic and xenogeneic bone blocks for application in humans

In the present study, the structure of two allogeneic and three xenogeneic bone blocks, which are used in dental and orthopedic surgery, were histologically analyzed. The ultimate goal was to assess whether the components postulated by the manufacturer can be identified after applying conventional histological and histochemical staining techniques. Three samples of each material, i.e. allogeneic material-1 and -2 as well as xenogeneic material-1, -2 and -3, were obtained commercially. After decalcification and standardized embedding processes, conventional histological staining was performed in order to detect inorganic matrix, cellular or organic matrix components. Allogeneic material-1 showed trabecular bone-like structures, which were free of cellular components as well as of organic matrix. The allogeneic material-2 showed trabecular bone structures, in which connective tissue and cellular remnants were embedded. Additionally, some connective tissue, which resembled fat-like tissue, was found within this material. The xenogeneic material-1 showed trabecular bone-like structures and contained organic components comparable to that demonstrated for the allogeneic material-2. The xenogeneic material-2 showed trabecular bone structures with single cells located in lacunae. The xenogeneic material-3 also showed trabecular structures. Neither cellular nor organic matrix components were found within this material. According to the data of the present study, the allogeneic material-1 and the xenogeneic material-3 were the only investigated materials for which the obtained histological data were in accordance with the manufactureŕs advertised information. The remaining three materials showed discrepancies—although the manufacturers of all five bone substitute materials stated that their blocks were free of organic/cellular remnants. These data are of great clinical and material science interest. It seems that even patented processing techniques are not always able to deliver reproducible materials. Although the manufacturers of all five bone blocks stated that their blocks were free of organic/cellular remnants, our histological analysis revealed that three out of five bone blocks did contain such remnants. Such specimens might be able to induce an immune response within the recipient.     

Salivary Epithelial Cells as Model to Study Immune Response Against Cutaneous Pathogens

The human skin not only provides passive protection as a physical barrier against external injury, but also mediates active surveillance via epidermal cell surface receptors that recognize and respond to potential invaders. Primary keratinocytes and immortalized cell lines, the commonly used sources to investigate immune responses of cutaneous epithelium are often difficult to obtain and/or potentially exhibit changes in cellular genetic make‐up. Here we investigated the possibility of using salivary epithelial cells (SEC) to evaluate the host response to cutaneous microbes. Elevated secretion of IFN‐γ and IL‐12 was observed in the SEC stimulated with Staphylococcus aureus, a transient pathogen of the skin, as mono species biofilm as compared to SEC stimulated with a commensal microbe, the Staphylococcus epidermidis. Co‐culture of the SEC with both microbes as dual species biofilm elicited maximum cytokine response. Stimulation with S. aureus alone but not with S. epidermidis alone induced maximum toll‐like receptor‐2 (TLR‐2) expression in the SEC. Exposure to dual species biofilm induced a sustained upregulation of TLR‐2 in the SEC for up to an hour. The data support novel application of the SEC as efficient biospecimen that may be used to investigate personalized response to cutaneous microflora.     

Cellular Pharmacokinetic Model-Based Analysis of Genistein,Glyceollin, and MK-571 Effects on 5 (and 6)-Carboxy-2′,7′-Dichloroflourescein Disposition in Caco-2 Cells

Pharmacokinetic modeling was used to describe 5 (and 6)-carboxy-2′,7′-dichloroflourescein (CDF) disposition in Caco-2 cells following CDF or CDFDA (CDF diacetate) dosing. CDF transcellular flux was modeled by simple passive diffusion. CDFDA dosing models were based on simultaneous fitting of CDF levels in apical, basolateral, and intracellular compartments. Predicted CDF efflux was 50% higher across the apical versus the basolateral membrane. This difference was similar following apical and basolateral CDFDA dosing, despite intracellular levels being 3-fold higher following basolateral dosing, thus supporting nonsaturable CDF efflux kinetics. A 3-compartment catenary model with intracellular CDFDA hydrolysis described CDF disposition. This model predicted that apical CDF efflux was not altered in the presence of MK-571, and that basolateral membrane clearance was enhanced to account for reduced intracellular CDF in the presence of this multidrug resistance-associated protein (MRP) inhibitor. Similar effects were predicted for glyceollin, while genistein exposure had no predicted effects on CDF efflux. These modulator effects are discussed in the context of model predicted intracellular CDF concentrations relative to reports of CDF affinity (measured by K_m) for MRP2 and MRP3. This model-based analysis confirms the complexity of efflux kinetics and suggests that other transporters may have contributed to CDF efflux.     

The Influence of In Vivo Metabolic Modifications on ADMET Properties of Green Tea Catechins–In Silico Analysis

The health effects of green tea are associated with catechins: (?)-epigallocatechin-3-O-gallate (EGCG), (?)-epigallocatechin, (?)-epicatechin-3-O-gallate, and (?)-epicatechin. An understanding of compound absorption, distribution, metabolism, excretion, and toxicity characteristics is essential for explaining its biological activities. Herein, absorption, distribution, metabolism, excretion, and toxicity properties of in vivo detected metabolites of green tea catechins (GTCs) have been analyzed in silico. The influence of metabolic transformations on absorption, distribution, metabolism, and excretion profiles of GTCs corresponds to the effects of size, charge, and lipophilicity, as already observed for other small molecules. Mutagenic, carcinogenic, or liver toxic effects were predicted only for a few metabolites. Similar to galloylated GTCs EGCG and (--)-epicatechin-3-O-gallate, the sulfo-conjugates were predicted to bind at the warfarin binding site. The low free plasma concentration of these derivatives may be consequential to their serum albumin binding. The activity cliff detected for methylated conjugates of EGCG indicates that GTCs' pro-oxidative activity in bound state comes primarily from free hydroxyl groups of the pyrogallol ring B.     

携带小鼠 KLF4 基因重组慢病毒的构建及对 RAW264.7 细胞增殖的影响

目的 构建小鼠 Krüppel 样因子 4（KLF4）慢病毒表达载体,并建立 KLF4 过表达小鼠腹腔巨噬细胞 RAW264.7 细胞株。方法 采用聚合酶链式反应（PCR）技术扩增目的基因 KLF4 后,构建重组质粒 pLVX-KLF4,并 通过 PCR、双酶切和测序方法对其进行鉴定。重组质粒与 pSPAX2、pMD2.G 辅助质粒通过 Lipofectamine® 3000 共转 染 293T 细胞,包装病毒并测定病毒滴度。将获得的慢病毒感染 RAW264.7 细胞,实时定量 PCR 法检测 KLF4 mRNA 的表达。分选流式细胞仪分选 GFP 阳性 RAW264.7 细胞。流式细胞术检测 KLF4 对 RAW264.7 细胞周期的影响。 EdU 法检测 KLF4 对 RAW264.7 细胞增殖的影响。结果 经 PCR、双酶切鉴定和测序证实,成功构建了包含小鼠 KLF4 基因的慢病毒穿梭质粒,RT-PCR 证实 Lenti-KLF4 感染的 RAW264.7 细胞中 KLF4 mRNA 表达高于未感染的 对照组 RAW264.7 细胞（P＜0.05）。初次浓缩后测定小鼠 KLF4 基因重组慢病毒的滴度为 2.05×108 TU/mL。分选出 KLF4 过表达的 RAW264.7 细胞。KLF4 过表达的 RAW264.7 细胞周期变化显示为 S 期延长,G0/G1 期缩短。EdU 检 测显示 KLF4 过表达的 RAW264.7 细胞增殖活性增高。结论 成功构建了 KLF4 的慢病毒表达载体,并建立 KLF4 过表达的 RAW264.7 细胞株,KLF4 过表达促进了 RAW264.7 细胞的增殖。     

Notch信号通路调控Treg/Th17细胞机制的研究进展

摘要： Notch家族是多细胞生物发育过程中一类高度保守的、 十分重要的跨膜信号蛋白, 通过与相邻细胞之间的相互作用, 在细胞增殖、 分化、 凋亡中发挥着关键作用。调节性T细胞 （Treg） 及辅助性T细胞17 （Th17） 是目前发现的一类新型CD4+ T细胞亚群, 在生理状态下, 两者可通过分泌多种细胞因子来调节机体免疫的平衡。近年来, 越来越多的研究发现Notch信号通路通过调控Treg、 Th17细胞参与机体多种疾病的发生。本文就Notch信号通路在血液系统疾病、 自身免疫系统疾病等疾病中对Treg/Th17细胞调控机制的研究进展作一简要综述。     

中性粒细胞缺乏血液病患者并发嗜麦芽窄食单胞菌败血症的临床特征和预后分析

目的 探讨中性粒细胞缺乏血液病患者发生嗜麦芽窄食单胞菌败血症的临床特征和预后因素。方法 回顾性分析我科2006年1月—2016年12月收治的32例发生嗜麦芽窄食单胞菌败血症合并中性粒细胞缺乏患者的临床资料。结果 32例患者中急性白血病20例, 重型再生障碍性贫血 （SAA） 7例, 非霍奇金淋巴瘤5例。所有患者长时间应用广谱抗生素, 中心静脉置管 （21例） 或者外周静脉置管 （11例）。25例化疗后出现中性粒细胞缺乏, 7例SAA 为本病导致中性粒细胞缺乏。死亡17例, 好转15例。药敏试验显示多药耐药, 替加环素、 甲氧苄啶-磺胺甲噁唑、 左氧氟沙星、 头孢哌酮/舒巴坦、 头孢他啶、 哌拉西林/他唑巴坦部分敏感, 其余均耐药。重度中性粒细胞缺乏、 重度血小板减少、 粒细胞减少持续时间过长和复合感染等是预后不良因素。结论 中性粒细胞缺乏血液病患者并发嗜麦芽窄食单胞菌败血症死亡率高, 及时诊断和治疗对预后至关重要。