药（毒）物对尸食性蝇类生长发育影响的研究进展

药（毒）物对尸食性蝇类生长发育影响是法医昆虫毒理学领域里一个十分重要的研究方向,其研究结果可对与药（毒）物相关死亡案件的死亡时间作出修正。随着近年来全球毒品及药物滥用情况的日趋严重,其所导致的死亡案件也越来越多。这类案件常常需要应用尸食性蝇类生长发育历期来推算死后经历时间（postmortem interval, PMI）。为了阐明该领域的研究进展以及未来研究的焦点和难点,本文在阐述法医昆虫毒理学概念和特点的基础上,按照不同的药（毒）物分类,对近年来药（毒）物对尸食性蝇类生长发育影响在国内外的研究进展进行了综述。研究表明,某些药（毒）物对尸食性蝇类生长发育具有一定的影响,且这种影响存在种属差异。目前,该领域的研究尚限于宏观现象观察阶段,其研究范围在不断拓宽,既有的研究也在进一步深化,但还有许多问题有待进一步探讨。     

相思子属三种药材中的氨基酸分析比较

利用全自动氨基酸分析仪和高效液相色谱仪分析比较相思子属三种药材中氨基酸成分及含量。结果9个样品都检测出17种氨基酸和2种色氨酸衍生物。结论:不同样品中的氨基酸含量有所差异,但其中门冬氨酸、谷氨酸、亮氨酸和赖氨酸的含量相对较高。     

Sperm binding, in vitro fertilization, and in vitro embryonic development of bovine oocytes fertilized with spermatozoa incubated with norepinephrine

The final stages of sperm maturation, fertilization, and early embryonic development occur within the oviduct and are essential for successful reproduction in mammals. Norepinephrine was previously identified in native bovine oviductal fluid and its in vitro effects on bull sperm capacitation and the acrosome reaction have been determined. It was unknown how physiological concentrations of norepinephrine influence sperm binding, fertilization, and embryo development. Therefore, the objective of this study was to determine if pre-incubating bovine spermatozoa with physiological concentrations of norepinephrine prior to insemination of bovine oocytes would improve sperm-oocyte binding, fertilization, and embryonic development in vitro. Norepinephrine, in concentrations representing those measured in bovine oviductal fluid, was used to treat bovine spermatozoa prior to insemination. Spermatozoa incubated in norepinephrine were used to inseminate bovine oocytes matured in vitro, and oocytes were evaluated for sperm binding and fertilization. Additional experiments were conducted to evaluate how early in the co-incubation period oocytes were fertilized by spermatozoa pre-incubated with norepinephrine, and to test the developmental competence of those oocytes fertilized with norepinephrine-treated sperm. Sperm binding to the zona pellucida was reduced by pre-incubation with norepinephrine. Rates of fertilization and embryo development did not increase as a result of pre-incubating spermatozoa with norepinephrine, but as early as 4h after insemination, spermatozoa treated with 20 ng/ml norepinephrine fertilized more oocytes than spermatozoa incubated in medium alone. Interestingly, this concentration of norepinephrine was found to capacitate spermatozoa in previous studies. These data suggest that oocytes fertilized by spermatozoa incubated in 20 ng/ml norepinephrine fertilize earlier in vitro than sperm pre-incubated in medium alone, and provide additional support for the role of norepinephrine in sperm capacitation and the acrosome reaction.     

Imaging macrophage chemotaxis in vivo: studies of microtubule function in zebrafish wound inflammation

The inflammatory response is one of the most dramatic examples of directed cell movement in nature. Inflammation is triggered at the site of injury and results in the migration of immune cells to the site to protect the host from infection. We have devised an in vivo inflammation assay using translucent zebrafish embryos, which allow live imaging and pharmacological manipulation of macrophage chemotaxis to wounds inflicted with a laser. Using this assay, we test the role of the microtubule cytoskeleton in macrophage chemotaxis in vivo using nocodazole to disrupt microtubule polymerization. We find that de-stabilisation of microtubules with nocodazole impairs macrophage recruitment to wounds, but that addition of the Rho kinase inhibitor Y-27632 suppresses these effects and restores the recruitment of macrophages to wounds. Taken together, these results suggest that destabilizing microtubules activates Rho kinase and that this increase in Rho kinase activity interferes with leukocyte recruitment in vivo.     

Marker assisted breeding for transformability in maize

Corn lines with improved culturability and transformability were produced using Marker Assisted Breeding (MAB) to introgress specific regions from the highly transformable hybrid, Hi-II, into the elite line, FBLL that responds very poorly in culture. FBLL is a female inbred parental stiff-stalk line that has been used to produce a series of some of DEKALB’s historically best selling hybrids. Five unlinked regions important for culturability and transformability were identified by segregation distortion analysis and introgressed into FBLL to produce the highly transformable FBLL-MAB lines. Agrobacterium mediated transformation was used to screen the FBLL-MAB lines and select the most efficient lines for transformation using immature embryo explants. Two highly efficient transformation systems were developed using kanamycin and glyphosate as selective agents. To evaluate agronomics, two testcross hybrids were produced for each of the three lead FBLL-MAB lines. A 25-location, 3-replication yield trial was used to evaluate grain yield, yield stability, and agronomic characteristics of the hybrids. Yields were found to be 2–5% lower and more stable (across a diverse set of environments) among hybrids produced with the FBLL-MAB lines as compared to the same hybrids produced with FBLL.     

African swine fever virus induces filopodia-like projections at the plasma membrane

When exiting the cell vaccinia virus induces actin polymerization and formation of a characteristic actin tail on the cytosolic face of the plasma membrane, directly beneath the extracellular particle. The actin tail acts to propel the virus away from the cell surface to enhance its cell-to-cell spread. We now demonstrate that African swine fever virus (ASFV), a member of the Asfarviridae family, also stimulates the polymerization of actin at the cell surface. Intracellular ASFV particles project out at the tip of long filopodia-like protrusions, at an average rate of 1.8 microm min(-1). Actin was arranged in long unbranched parallel arrays inside these virus-tipped projections. In contrast to vaccinia, this outward movement did not involve recruitment of Grb2, Nck1 or N-WASP. Actin polymerization was not nucleated by virus particles in transit to the cell periphery, and projections were not produced when the secretory pathway was disrupted by brefeldin A treatment. Our results show that when ASFV particles reach the plasma membrane they induce a localized nucleation of actin, and that this process requires interaction with virus-encoded and/or host proteins at the plasma membrane. We suggest that ASFV represents a valuable new model for studying pathways that regulate the formation of filopodia.     

Rerouting carbon flux to enhance photosynthetic productivity

The bioindustrial production of fuels, chemicals, and therapeutics typically relies upon carbohydrate inputs derived from agricultural plants, resulting in the entanglement of food and chemical commodity markets. We demonstrate the efficient production of sucrose from a cyanobacterial species, Synechococcus elongatus, heterologously expressing a symporter of protons and sucrose (cscB). cscB-expressing cyanobacteria export sucrose irreversibly to concentrations of >10 mM without culture toxicity. Moreover, sucrose-exporting cyanobacteria exhibit increased biomass production rates relative to wild-type strains, accompanied by enhanced photosystem II activity, carbon fixation, and chlorophyll content. The genetic modification of sucrose biosynthesis pathways to minimize competing glucose- or sucrose-consuming reactions can further improve sucrose production, allowing the export of sucrose at rates of up to 36.1 mg liter(-1) h illumination(-1). This rate of production exceeds that of previous reports of targeted, photobiological production from microbes. Engineered S. elongatus produces sucrose in sufficient quantities (up to ～80% of total biomass) such that it may be a viable alternative to sugar synthesis from terrestrial plants, including sugarcane.     

The role of circulating serotonin in the development of chronic obstructive pulmonary disease

Background

Cigarette smoking is a major risk factor in the development of age-related chronic obstructive pulmonary disease (COPD). The serotonin transporter (SERT) gene polymorphism has been reported to be associated with COPD, and the degree of cigarette smoking has been shown to be a significant mediator in this relationship. The interrelation between circulating serotonin (5-hydroxytyptamine, 5-HT), cigarette smoking and COPD is however largely unknown. The current study aimed at investigating the mediation effects of plasma 5-HT on cigarette smoking-induced COPD and the relation between plasma 5-HT levels and age.

Methods

The association between plasma 5-HT, age and COPD was analyzed in a total of 62 COPD patients (ever-smokers) and 117 control subjects (healthy non-smokers and ever-smokers). Plasma 5-HT levels were measured by enzyme-linked immuno assay (EIA).

Results

The elevated plasma 5-HT levels were significantly associated with increased odds for COPD (OR = 1.221, 95% CI = 1.123 to 1.319, p<0.0001). The effect remained significant after being adjusted for age and pack-years smoked (OR = 1.271, 95% CI = 1.134 to 1.408, p = 0.0003). Furthermore, plasma 5-HT was found to mediate the relation between pack-years smoked and COPD. A positive correlation (r = 0.303, p = 0.017) was found between plasma 5-HT levels and age in COPD, but not in the control subjects (r = −0.149, p = 0.108).

Conclusion

Our results suggest that cigarette smoke-induced COPD is partially mediated by the plasma levels of 5-HT, and that these become elevated with increased age in COPD. The elevated plasma 5-HT levels in COPD might contribute to the pathogenesis of this disease.     

氮气气腹制作腹内高压对肝脏功能的影响

目的研究腹内压升高及持续时间对肝脏功能的影响。方法选择SD大鼠45只,随机分为正常对照组,10mmHg腹内压(IAP)模型组,20mmHg腹内压(IAP)模型组,每组15只。各IAP组大鼠以头皮针于腹腔穿刺,通过三通管连接压力计及氮气袋,运用氮气气腹法制作SD大鼠腹内高压动物模型,对照组不充气。各组动物按腹内压持续时间分别于1、2、4h处死,使用全自动生化分析仪检测每个动物的天门冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)。结果 10mmHg和20mmHg IAP持续4h组的血清AST、ALT含量均明显高于持续1h和2h组(P<0.01,P<0.05);20mmHg IAP 2h组血清AST、ALT含量亦明显高于1h组(P<0.05);但10mmHg IAP持续2h组血清AST、ALT含量与1h相比,差异无统计学意义(P>0.05)。IAP维持1h的3组(10mmHg组,20mmHg组,对照组)大鼠的血清AST、ALT含量差异无统计学意义(P>0.05);IAP持续2h,20mmHg IAP组的AST、ALT含量明显高于10mmHg IAP组和对照组;IAP维持4h,20mmHg IAP组血清AST、ALT含量均显著高于对照组(P<0.01),较10mmHg IAP组血清AST含量增高(P<0.05),而ALT间比较无统计学意义(P>0.05);10mmHg IAP组持续4h组血清AST、ALT含量高于对照组4h组(P<0.01,P<0.05)。结论腹内高压可致肝损伤,并与腹腔压力和时间密切相关。SD大鼠腹内高压动物模型的制作简易、稳定可靠,且可重复。     

细胞粘附分子群相互作用网络模型研究

通过相互作用网络可视化软件Cytoscape对整联蛋白粘合体156种成份及相互间的690个反应实现网络可视化,并通过网络分析软件network analyser得到该网络节点间的平均连接并不复杂是一个不可分割的整体网络,网络较稳定,信息传递很快等。直接可视化的网络通过节点的形状改变视图有助于我们在原始数据的基础上更好的认识这一复杂的作用网络的相关信息。