A candidate multi-epitope vaccine against porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae induces robust humoral and cellular response in mice

Porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae (M. hyopneumoniae, Mhp) are two of the most common pathogens involved in the porcine respiratory disease complex (PRDC) resulting in significant economic losses worldwide. Vaccination is the most effective approach to disease prevention. Since PRRSV and Mhp co-infections are very common, an efficient dual vaccine against these pathogens is required for the global swine industry. Compared with traditional vaccines, multi-epitope vaccines have several advantages, they are comparatively easy to produce and construct, are chemically stable, and do not have an infectious potential. In this study, to develop a safe and effective vaccine, B cell and T cell epitopes of PRRSV-GP5, PRRSV-M, Mhp-P46, and Mhp-P65 protein had been screened to construct a recombinant epitope protein rEP-PM that has good hydrophilicity, strong antigenicity, and high surface accessibility, and each epitope is independent and complete. After immunization in mice, rEP-PM could induce the production of high levels of antibodies, and it had good immunoreactivity with anti-rEP-PM, anti-PRRSV, and anti-Mhp antibodies. The anti-rEP-PM antibody specifically recognizes proteins from PRRSV and Mhp. Moreover, rEP-PM induced a Th1-dominant cellular immune response in mice. Our results showed that the rEP-PM protein could be a potential candidate for the development of a safe and effective multi-epitope peptide combined vaccine to control PRRSV and Mhp infections.     

Microstructural properties of the mid-facial bones in relation to the distribution of occlusal loading

Although the concept of the occlusal load transfer through the facial skeleton along the buttresses has been extensively studied, there has been no study to link microarchitecture of the mid-facial bones to the occlusal load distribution. The aim of this study was to analyze micro-structural properties of the mid-facial bones in relation to occlusal stress. The study was performed by combining the three-dimensional finite element analysis (3D FEA) and micro-computed tomography analysis (micro-CT). Clenching was simulated on the computer model of the adult male human skull which was also used as a source of bone specimens. After the FEA was run, stress was measured at the specific sites in cortical shell and trabecular bone of the model along and between the buttresses. From the corresponding sites on the skull, twenty-five cortical and thirteen cancellous bone specimens were harvested. The specimens were classified into high stress or low stress group based on the stress levels measured via the FEA. Micro-architecture of each specimen was assessed by micro-CT. In the high stress group, cortical bone showed a tendency toward greater thickness and density, lower porosity, and greater pore separation. Stress-related differences in microstructure between the groups were more pronounced in trabecular bone, which showed significantly greater bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) in the high stress group. Our results suggest that the mid-facial bones in the adult dentate male skull exhibit regional variations in cortical and trabecular bone micro-architecture that could be a consequence of different occlusal stress.     

Whole genome alignment based one-step real-time RT-PCR for universal detection of avian orthoreoviruses of chicken,pheasant and turkey origins

Newly emerging avian orthoreovirus (ARV) variants have been continuously detected in Pennsylvania poultry since 2011. In this paper, we report our recent diagnostic assay development of one-step real-time RT-PCR (rRT-PCR) for the rapid and universal detection of all ARVs or reference strains of chicken, pheasant and turkey origins and six σC genotypes of the newly emerging field ARV variants in Pennsylvania (PA) poultry. Primers and probes for the rRT-PCR were designed from the conserved region of the M1 genome segment 5′ end based on the whole-genome alignment of various ARV strains, including six field variants or novel strains obtained in PA poultry. The detection limit of the newly developed rRT-PCR for ARV was as low as 10 copies/reaction of viral RNA, and 10^0.50–10^0.88 tissue culture infectious dose (TCID₅₀)/100 μL of viruses. This new rRT-PCR detected all six σC genotypes from the 66 ARV field variant strains and reference strains tested in this study. There were no cross-reactions with other avian viruses. Reproducibility of the assay was confirmed by intra- and inter-assay tests with variability from 0.12% to 2.19%. Sensitivity and specificity of this new rRT-PCR for ARV were achieved at 100% and 88%, respectively, in comparison with virus isolation as the “gold standard” in testing poultry tissue specimen.     

N- 甲基-D- 天冬氨酸受体在记忆网络中的作用

N- 甲基-D- 天冬氨酸（N-methyl-D-aspartate，NMDA）受体属于谷氨酸离子型受体，其与突触的可塑性和学习记忆密切相关。中枢神经系统中与学习记忆相关的，如以胆碱受体、腺苷A1 受体等为代表的诸多受体及递质，以谷氨酸（glutamate，Glu）为代表的氨基酸能神经通路，以长时程增强（long-term potentiation，LTP）等为代表的脑内神经电活动，以脑源性神经营养因子（brain-derived neurotrophic factor，BDNF）等为代表的基因蛋白遗传信息改变，甚至许多神经退行性疾病中Glu 的神经毒性等，都与NMDA 受体相关，通过NMDA 受体功能的改变调控学习记忆功能，进而对整个中枢神经系统产生影响。换句话说，如果把学习记忆的信息传递系统看做一个庞大的信息网络，那么NMDA 受体就是学习记忆相关神经网络中一个相对中心的关键位点。因此，以探讨NMDA 受体在学习记忆错综复杂网络中的关联为切入点，以微观深入研究为基础、以宏观视野分析为引领，全方位评价NMDA 受体在学习记忆网络中的作用，或许可以引领未来脑功能及相关疾病系统的研究。     

Heat shock protein is a key therapeutic target for nerve repair in autoimmune peripheral neuropathy and severe peripheral nerve injury

Guillain-Barré syndrome (GBS) is an autoimmune peripheral neuropathy and a common cause of neuromuscular paralysis. Preceding infection induces the production of anti-ganglioside (GD) antibodies attacking its own peripheral nerves. In severe proximal peripheral nerve injuries that require long-distance axon regeneration, motor functional recovery is virtually nonexistent. Damaged axons fail to regrow and reinnervate target muscles. In mice, regenerating axons must reach the target muscle within 35 days (critical period) to reform functional neuromuscular junctions and regain motor function. Successful functional recovery depends on the rate of axon regeneration and debris removal (Wallerian degeneration) after nerve injury. The innate-immune response of the peripheral nervous system to nerve injury such as timing and magnitude of cytokine production is crucial for Wallerian degeneration. In the current study, forced expression of human heat shock protein (hHsp) 27 completely reversed anti-GD-induced inhibitory effects on nerve repair assessed by animal behavioral assays, electrophysiology and histology studies, and the beneficial effect was validated in a second mouse line of hHsp27. The protective effect of hHsp27 on prolonged muscle denervation was examined by performing repeated sciatic nerve crushes to delay regenerating axons from reaching distal muscle from 37 days up to 55 days. Strikingly, hHsp27 was able to extend the critical period of motor functional recovery for up to 55 days and preserve the integrity of axons and mitochondria in distal nerves. Cytokine array analysis demonstrated that a number of key cytokines which are heavily involved in the early phase of innate-immune response of Wallerian degeneration, were found to be upregulated in the sciatic nerve lysates of hHsp27 Tg mice at 1 day postinjury. However, persistent hyperinflammatory mediator changes were found after chronic denervation in sciatic nerves of littermate mice, but remained unchanged in hHsp27 Tg mice. Taken together, the current study provides insight into the development of therapeutic strategies to enhance muscle receptiveness (reinnervation) by accelerating axon regeneration and Wallerian degeneration.     

脐血中胰岛素、胰岛素样生长因子-I及胰岛素样生长因子结合蛋白-2与胎儿生长受限的关系

目的探讨脐血中胰岛素、胰岛素样生长因子-I及胰岛素样生长因子结合蛋白-2的水平与胎儿生长受限的关系及意义。方法收集2011年7月～2013年5月在本院分娩的单胎足月正常妊娠（无产科并发症）孕妇及其新生儿各120例,根据出生体重将新生儿分为小于胎龄儿（SGA）组、适于胎龄儿（AGA）2组。胎儿娩出后即抽脐静脉血5ml,标本收集后用高效液相色谱法测定脐血中胰岛素、胰岛素样生长因子-I及胰岛素样生长因子结合蛋白-2的水平。结果SGA组脐带血清胰岛素、胰岛素样生长因子-I水平明显低于AGA组,差异均有统计学意义（P〈0.01）;SGA组脐血胰岛素样生长因子结合蛋白-2水平明显高于AGA、组,差异有统计学意义（P〈0.01）;脐血中胰岛素样生长因子-I与胰岛素水平呈正相关关系,而与胰岛素样生长因子结合蛋白-2呈负相关关系;脐血胰岛素、胰岛素样生长因子-I水平与新生儿出生体重呈正相关关系,而胰岛素样生长因子结合蛋白2与之呈负相关关系。结论脐血胰岛素、胰岛素样生长因子-I、胰岛素样生长因子结合蛋白2与胎儿生长受限的发生密切相关。     

从2019-nCoV和SARS-CoV的侵袭靶点血管紧张素转化酶2寻找新型冠状病毒肺炎的救治策略

自2019年12月以来,新型冠状病毒（2019-nCoV）感染在中国武汉引发了新型冠状病毒肺炎的爆发,并引起了公众的极大关注。2019-nCoV与SARS-CoV均属于冠状病毒科,均通过血管紧张素转化酶2（ACE2）侵入靶细胞。深入了解ACE2及病毒侵入人体后以其为中心引起的一系列病生理变化机制,可能有助于发现并解释相应的临床现象,进而及时予以处理;另外ACE2是潜在的治疗靶点,可以此寻找相应的救治策略。本文阐述了ACE2在2019-nCoV及SARS-CoV所致多脏器损伤中的作用、针对ACE2的靶向阻断药物以及抑制炎性反应的药物,旨在为后续相关研究及诊治、药物研发提供依据。     

马勃的化学成分及其药理作用的研究进展

马勃（Lasiosphaera seu Calvatia）是大型食药用真菌,为灰包科真菌脱皮马勃、大马勃或紫色马勃的干燥子实体,其营养成分十分丰富,在2015 年《中国药典》中记载功能与主治清肺利咽,止血,用于风热郁肺咽痛,音哑,咳嗽,外治鼻衄,创伤出血。该文通过对马勃的种类、化学成分及其药用的功效进行综述,为此类真菌研究开发做进一步参考。     

Efficient production of high-molecular-weight hyaluronic acid with a two-stage fermentation

In this paper, the production pattern of hyaluronic acid (HA) was revealed: the chain growth of HA mainly occurred in the first half of fermentation while the product accumulated throughout the fermentation period. Attempts were made to develop a two-stage fermentation process which provided high-level synthesis in both product titer and molecular weight. The pH was kept at 8.0 with a temperature of 31 °C in the first fermentation stage (0–10 h) to promote the growth of weight-average molecular weight (M_w), and the pH and temperature were maintained at 7.0 and 37 °C, respectively, in the following fermentation stage to facilitate HA accumulation. In addition, constant rates of aeration (1 vvm) and agitation (600 rpm) were adopted. The two-stage fermentation provided a balanced result in which a product titer of 4.75 g L⁻¹ and a M_w of 2.36 × 10⁶ Da were achieved under optimized conditions. The process introduces an effective way to produce HA considering the effect of segmented control strategy.

A two-stage fermentation process with a segmented control strategy provides high-level synthesis in both HA titer and molecular weight.     

新型冠状病毒肺炎CT征象再讨论

目的寻找新型冠状病毒肺炎（NCP）的特征性CT征象,并从影像病理学角度探讨其临床意义。方法收集整理2020年1月26日至2月12日河北省确诊为NCP的40例病人的CT图像,对其72侧肺部,234个肺段,共459个病灶进行分析;同时与随机抽取的20例本院诊治的其他性质肺炎（非NCP）病人的28侧肺部,79个肺段,共258个病灶的CT图像进行比较研究。结果NCP组病灶多位于两肺下叶（分别为30个,23.44%）,多累及双侧（32例,80.00%）,且累及5个肺叶的比例较大,其在左、右侧肺分布上差异不大,伴有胸腔积液的仅为1例（2.50%）。NCP组与非NCP组在病灶累及肺叶数量、扇形分布、肺血增多或肺水肿、伴有血管增粗和支气管壁增厚上差异有统计学意义。18例有复查资料的患者中有进展的为13例（占72.22%）,其中8例有肺血增多或肺水肿（占62%）,11例累及双侧（约占85%）。结论NCP的CT表现有其特征性,而且其可能更容易侵犯血管引起血管炎,进而会导致肺水肿和心肺循环紊乱的发生,这对于预测患者病情发展可能具有提示作用。