高温大曲中地衣芽胞杆菌(Bacillus licheniformis CGMCC 3963)的耐高温特征

【目的】高温大曲的使用是中国酱香型白酒酿造的特征之一,耐高温的细菌是高温大曲中重要的优势功能菌,它们对酱香型白酒的酿造具有重要的价值。研究高温大曲中细菌的耐高温特征对于认识酱香型白酒的酿造特征具有一定的作用。【方法】本文以中国白酒高温大曲中筛选获得的一株具有自主知识产权的耐高温功能细菌地衣芽胞杆菌(Bacillus licheniformis)CGMCC 3963为对象,测定其耐高温特征,并首次通过细胞形态学的分析,以及转录组学等技术的应用系统研究了B.licheniformis CGMCC 3963的耐高温机制。【结果】地衣芽胞杆菌B.licheniformis CGMCC 3963能够耐受55℃高温生长。在高温条件下,该菌仍具有较旺盛的代谢生长能力,且产生大量荚膜,同时大量I类热休克蛋白基因以及聚谷氨酸合成基因的表达水平均得到明显提高。【结论】B.licheniformis CGMCC 3963在高温下,I类热休克蛋白以及以聚谷氨酸为主要成分的荚膜大量产生,对功能细菌耐高温具有重要的作用。该结果首次从分子水平认识了中国白酒酿造微生物的耐高温特征,丰富了白酒酿造微生物学的科学理论。     

Role of the Protective Antigen Octamer in the Molecular Mechanism of Anthrax Lethal Toxin Stabilization in Plasma

Anthrax is caused by strains of Bacillus anthracis that produce two key virulence factors, anthrax toxin (Atx) and a poly-γ-D-glutamic acid capsule. Atx is comprised of three proteins: protective antigen (PA) and two enzymes, lethal factor (LF) and edema factor (EF). To disrupt cell function, these components must assemble into holotoxin complexes, which contain either a ring-shaped homooctameric or homoheptameric PA oligomer bound to multiple copies of LF and/or EF, producing lethal toxin (LT), edema toxin, or mixtures thereof. Once a host cell endocytoses these complexes, PA converts into a membrane-inserted channel that translocates LF and EF into the cytosol. LT can assemble on host cell surfaces or extracellularly in plasma. We show that, under physiological conditions in bovine plasma, LT complexes containing heptameric PA aggregate and inactivate more readily than LT complexes containing octameric PA. LT complexes containing octameric PA possess enhanced stability, channel-forming activity, and macrophage cytotoxicity relative to those containing heptameric PA. Under physiological conditions, multiple biophysical probes reveal that heptameric PA can prematurely adopt the channel conformation, but octameric PA complexes remain in their soluble prechannel configuration, which allows them to resist aggregation and inactivation. We conclude that PA may form an octameric oligomeric state as a means to produce a more stable and active LT complex that could circulate freely in the blood.     

参乌胶囊及其有效成分二苯乙烯苷对老年大鼠脊髓腰节段细胞凋亡调节因子及p-CREB的影响

目的观察中药新复方参乌胶囊及其有效成分何首乌二苯乙烯苷对老年大鼠脊髓腰节段细胞凋亡及信号转导通路的影响。方法雄性SD大鼠,分为青年组（6月龄）、老年组（24月龄）、老年＋参乌胶囊小剂量（0.8 g/kg）、参乌胶囊大剂量（1.6 g/kg）、二苯乙烯苷小剂量（0.03 g/kg）、二苯乙烯苷大剂量（0.06 g/kg）组。应用Western blot方法检测大鼠脊髓腰节段Bax、Bcl-2及磷酸化cAMP反应元件结合蛋白（p-CREB）的变化及药物的干预作用。结果与6月龄青年大鼠相比,24月龄老年大鼠脊髓腰节段凋亡促进因子Bax的表达增加,凋亡抑制因子Bcl-2的表达减少,神经元存活信号转导通路中p-CREB的表达降低。参乌胶囊和二苯乙烯苷分别灌胃给药3个月能够抑制老年大鼠脊髓腰节段内BAX的表达,增强Bcl-2表达。参乌胶囊还能够上调p-CREB表达。结论乌胶囊及二苯乙烯苷能够改善老年大鼠脊髓腰节段Bax、Bcl-2和p-CREB的变化,提示该药可能具有延缓脊髓衰老的作用。     

Changes to the mechanical properties of the glenohumeral capsule during anterior dislocation

The glenohumeral joint is the most frequently dislocated major joint in the body, and instability due to permanent deformation of the glenohumeral capsule is a common pathology. The corresponding change in mechanical properties may have implications for the ideal location and extent of plication, which is a common clinical procedure used to repair the capsule. Therefore, the objective of this study was to quantify the mechanical properties of four regions of the glenohumeral capsule after anterior dislocation and compare the properties to the normal glenohumeral capsule. Six fresh-frozen cadaveric shoulders were dislocated in the anterior direction with the joint in the apprehension position using a robotic testing system. After dislocation, mechanical testing was performed on the injured glenohumeral capsule by loading the tissue samples in tension and shear. An inverse finite element optimization routine was used to simulate the experiments and obtain material coefficients for each tissue sample. Cauchy stress–stretch curves were then generated to represent the mechanical response of each tissue sample to theoretical loading conditions. Based on several comparisons (average of the material coefficients, average stress–stretch curve for each region, and coefficients representing the average curves) between the normal and injured tissue samples, the mechanical properties of the injured tissue samples from multiple regions were found to be lower than those of the normal tissue in tension but not in shear. This finding indicates that anterior dislocation primarily affects the tensile behavior of the glenohumeral capsule rather than the shear behavior, and this phenomenon could be caused by plastic deformation of the matrix, permanent collagen fiber rotation, and/or collagen fiber failure. These results suggest that plication and suturing may not be sufficient to return stability to the shoulder after dislocation in all individuals. Thus, surgeons may need to perform a procedure that reinforces or stiffens the tissue itself, such as reconstruction or augmentation, to improve repair procedures.     

Carbonaceous Resin Capsule for Vapor-phase Monitoring of Volatile Monoaromatic Hydrocarbons in Soil

Soil and groundwater contamination by organic substances is a major environmental and health concern, but methods of direct, in situ evaluation of quantities and forms of these contaminants are generally highly limited. The resin capsule system (RCS) has been developed for use in the laboratory or in the field for inorganic chemicals, and its application has been extended to include organic chemicals by incorporation of carbonaceous, hydrophobic adsorbers in the capsules. The objective of this study was to determine the efficacy of carbonaceous resin capsules for detecting benzene, toluene, ethylbenzene, and xylene (BTEX) vapors diffusing through a soil column, and to investigate sensitivity to environmental factors that influence vapor phase diffusion. Results show that the RCS can serve as a trap for organic vapors, and that quantities of BTEX accumulated are influenced by soil texture and water content during extended adsorption times. The nature of these effects, as measured by the RCS, was similar to expectations, based on previously reported results from studies involving direct measurements. These results provide evidence that the RCS could be developed to serve as a simple, inexpensive, direct, in situ methodology for monitoring volatile organic chemicals in soils.     

通痹胶囊治疗类风湿关节炎的疗效及对微循环和血清MMP-1、MMP-3的影响

目的:探讨通痹胶囊治疗类风湿关节炎(RA)的疗效及对微循环指标和基质金属蛋白酶-1(MMP-1)、血清基质金属蛋白酶-3(MMP-3)的影响。方法:选取2016年1月～2018年9月期间我院收治的90例RA患者,按照随机数字表法分为研究组(n=45)、对照组(n=45)。对照组患者给予来氟米特、甲氨蝶呤常规治疗,研究组在对照组基础上联合通痹胶囊治疗,比较两组患者疗效、治疗前后的微循环指标[血管阻力指数(RI)、舒张期峰值速度(EDV)以及收缩期峰值速度(PSV)]、MMP-1、MMP-3、类风湿因子滴度(RF)、C反应蛋白(CRP)、红细胞沉降率(ESR)、抗链球菌溶血素"O"(ASO),记录两组治疗期间不良反应发生情况。结果:研究组治疗4个月后的临床总有效率高于对照组(P0.05)。两组患者治疗4个月后RI、MMP-1、MMP-3、CRP、RF、ESR、ASO下降,且研究组低于对照组(P0.05);EDV、PSV升高,且研究组高于对照组(P0.05)。两组患者不良反应发生率比较无差异(P0.05)。结论:在常规治疗的基础上联合通痹胶囊可有效缓解RA病情,改善机体微循环,降低血清MMP-3、MMP-1水平,且用药安全性较好。     

Seed weight and seed number affect subsequent fitness in outcrossing and selfing Primula species

Using the outcrossing Primula farinosa and its autogamous selfing relatives P. scotica , P. scandinavica and P. stricta , we compared the fitness of light and heavy seeds. Heavy seeds germinated in greater numbers and more quickly. In competition with seedlings grown from lighter seeds, heavy seeds produced larger rosettes. In P. farinosa such seedlings went on to produce more seeds, and in two populations heavier seeds, than plants from lighter seeds. After transplantation to natural populations, seedlings of P. farinosa derived from heavy seeds produced larger rosettes, more flowers and seeds than those from lighter seeds in certain populations so that seedlings born of heavy seeds were much fitter than seedlings from lighter seeds. Average seed weight varied in inverse proportion to seed number per capsule. The autogamous species produced on average about twice as many seeds per capsule as P. farinosa . In P. scotica and P. stricta this difference appears to be due in part to assured fertilization, but this high fecundity did not cause disadvantageously light seeds. As these species produced fewer capsules per scape, their overall seed production was on average no greater than for P. farinosa . P. farinosa traded-off fitness between capsules with large seed numbers, which donated more offspring to the next generation, and those with small seed numbers, whose heavy seeds would be more likely to reproduce themselves in the next generation. We conclude that low fecundity in outcrossing species might at times be advantageous.     

移植物宿主反应的评价方法探讨

目的：研究移植物入机体后产生宿主反应的评价方法。方法：通过测量移植物植入机体后不同时期出现的结缔组织包囊的厚度变化，并进行统计学分析，从而探讨移植物的宿主反应特性的方法。结果：通过实验综合分析得出经表面处理的移植物的宿主反应特性较原为移植物有明显好转。结论：移植物植入机体后出现的结缔组织包囊的厚度变化，经统计学分析，可充分反应该移植物的宿主反应特性。通过本实验可较有效地、正确地评价该移植物的生物学特性。