人参皂苷Rd-羟丙基-β-环糊精包合物的制备和表征

对人参皂苷Rd-羟丙基-β-环糊精包合物的制备和表征进行研究。采用溶剂-搅拌法制备包合物,然后用差示扫描量热法、红外光谱法以及显微镜法对得到的产物进行表征,3种表征方法均表明包合物已经形成。用高效液相色谱法测定包合物中人参皂苷Rd的含量为7.53%,包合物在25℃下的溶解度比人参皂苷Rd增大了24.3倍,在37℃下的溶解度增大了219倍。包合物水溶性良好,说明羟丙基-β-环糊精作为药物载体可以提高药物溶解度。     

人参皂苷Rd的理化性质及降解研究

采用RP-HPLC法和摇瓶法测定了人参皂苷Rd在水和不同pH介质中的平衡溶解度及其在正辛醇-水及各pH介质组成的体系中的表观油水分配系数(P_(app)),并考察了人参皂苷Rd在4个强降解条件下的降解情况。结果表明:在25℃时,人参皂苷Rd在水(pH 7.0)和不同pH(1.0,2.0,4.0,5.8,6.8,7.4)介质中的平衡溶解度依次为0.224,0.015,0.050,0.116,0.136,0.439,0.201 g/L;人参皂苷Rd在水中的Papp=32.45(lg Papp=1.51),在不同pH介质中的油水分配系数均接近或大于1;人参皂苷Rd在0.1 mol/L Na OH、0.1 mol/L HCl、70℃、0.3%H2O24个强降解条件下,放置7 d后的降解率分别为20.02%、88.53%、28.15%、69.81%。上述研究结果表明:人参皂苷Rd极微溶于水,脂溶性好,且不同的pH对其溶解度和Papp均具有较大影响,在碱和高温条件下较稳定,在酸和氧化条件下降解较快。     

Evaluating Domestic Sheep Survival with Different Breeds of Livestock Guardian Dogs

Livestock guard dogs (LGDs; Canis familiaris) have been widely adopted by domestic sheep (Ovis aries) producers because they reduce predation by wild carnivores. LGDs were originally used in the United States to reduce coyote (Canis latrans) depredations, but their efficacy against a suite of large carnivores, including wolves (Canis lupus), brown bears (Ursus arctos), black bears (Ursus americanus), and cougars (Puma concolor), and whether specific breeds perform better than others remains unclear. To assess breed-specific effectiveness at reducing depredations from a suite of livestock predators, we compared survival rates of sheep protected by different breeds of LGDs, including three breeds from Europe (Turkish kangal, Bulgarian karakachan, and Portuguese cão de gado transmontano) and mixed-breed LGDs, “whitedog,” common in the United States. With the help of participating sheep producers, we collected cause-specific mortality data from domestic sheep in Idaho, Montana, Oregon, and Wyoming between 2013 and 2016. All three of the novel breeds of LGD tested were associated with overall reductions in sheep depredation relative to whitedogs, ranging from 61% to 95% (P < 0.05). In terms of predator-specific effectiveness, the Turkish kangal was associated with decreases in depredation from cougars (e^β = 0.31, 95% CI = 0.10–0.94, P = 0.04), black bears (e^β = 0.33, 95% CI = 0.28–0.37, P < 0.01), and coyotes (e^β = 0.56, 95% CI = 0.35–0.90, P = 0.02). The Bulgarian karakachan was associated with a decrease in coyote depredations (e^β = 0.07, 95% CI = 0.01–0.49, P < 0.01). The Portuguese transmontano was not associated with significant reductions in depredation hazard for any specific predator. Although variations in breed-specific effectiveness were subtle and nuanced, these findings will help livestock producers and wildlife managers make tailored decisions about how best to incorporate different breeds of LGD into sheep grazing regimes.     

Microbacteriu estmeraromaticum GS514菌株中一种人参皂苷β-葡萄糖苷酶的分离及其性质研究

人参土壤微生物Microbacterium esteraromaticum GS514显示出良好的人参皂苷转化能力.采用DEAE-cellulose DE-52阴离子交换树脂,从人参土壤微生物Microbacterium esteraromaticum GS514中分离一种使人参皂苷Rb1水解为人参皂苷Rd的β-葡萄糖苷酶,并进行酶性质研究.结果表明,该酶分子量约为58.7kDa,在pH值6.5和40℃时显示出最强酶活性.     

心悦滴丸的质量标准研究

目的建立心悦滴丸的质量标准。方法采用TLC对心悦滴丸中西洋参茎叶总皂苷进行定性鉴别;采用HPLC测定人参皂苷Rb2、Rb3、Rd的含量,色谱条件为Agilent ODS C18色谱柱(4.6mm×250mm,5 m),乙腈-0.05%磷酸水溶液为流动相梯度洗脱,流速1.0m L/min,检测波长203nm,柱温40℃。结果心悦滴丸中西洋参茎叶总皂苷的薄层色谱斑点清晰。人参皂苷Rb2在0.748~4.704μg范围内呈良好线性关系(r=0.9999),平均回收率为96.2%(RSD1.9%);人参皂苷Rb3在1.632~9.792μg范围内呈良好线性关系(r=0.9999),平均回率为97.5%(RSD1.7%);人参皂苷Rd在0.96~5.76μg范围内呈良好线性关系(r=0.9999),平均回收率为96.6%(RSD2.1%)。结论建立的方法操作简便、专属性强、灵敏度高、重复性好,可作为心悦滴丸的质量控制标准。     

利用农杆菌介导法获得转codA基因麻竹再生植株的研究

温度是影响植物生存和生长发育的基本环境因子之一。大多数植物对低温等都是高度敏感的,低温伤害现象尤为突出,几乎涉及所有的经济植物。因此,改善植物的抗低温冻害的胁迫能力,可以显著提高植物的生长范围、增加产量。codA基因可以增加植物对低温胁迫的耐受能力,而Rd29A是一种胁迫诱导特异表达启动子,胁迫条件可以快速诱导基因表达,也可以减少由于转基因过量表达带来的不利影响。研究以麻竹花药离体培养的愈伤组织为材料,采用农杆菌介导法,探讨了影响麻竹愈伤组织遗传转化效率的主要因子。结果表明,潮霉素的最佳筛选浓度是25 mg.L-1,预培养时间为3 d,侵染时间为20 min,共培养时间为3 d,乙酰丁香酮的浓度控制在100 mg.L-1时可以有效的提高遗传转化效率。在此基础上对获得的转基因植株进行分子检测,初步表明外源基因codA已经整合到麻竹基因组中。     

一种快速检测启动子调控基因表达活性方法的探讨

启动子活性检测是基因工程实验的重要组成部分,利用绿色荧光蛋白(GFP)基因作为报告基因,对rd29A启动子在受体细胞中调控基因表达的活性进行检测,采用基因枪法进行对洋葱表皮细胞的遗传转化,培养24h后在荧光显微镜下观察GFP基因的表达情况,并通过软件测定不同培养条件下GFP基因表达后的荧光强度,能较为准确的鉴定该启动子的活性大小,并达到量化目的。方法简单、省时、可靠,可以作为一种有效的检测启动子活性的方法。     

Severe Leukemoid Response Associated With Mycobacterium genavense Infection in a Pet Budgerigar (Melopsittacus undulatus)

A 2-year-old pet budgerigar was presented after a period of general malaise that was unresponsive to supportive therapy. Radiographic images revealed a marked hepatomegaly. Hematology results indicated the bird had a severe leukocytosis with marked discrepancy between the hemocytometer white blood cell (WBC) count and WBC estimated from the smear. The leukocytosis was characterized by an extreme heterophilia with marked left shift, including the presence of metamyelocytes and promyelocytes with marked toxic changes, and a marked monocytosis, consistent with a leukemoid response. The bird died despite supportive treatment. Hepatosplenomegaly was present at necropsy. Histopathology of multiple tissues demonstrated acid-fast organisms on Ziehl-Neelsen staining, subsequently identified as Mycobacterium genavese by polymerase chain reaction analysis. Mycobacteriosis should be considered as a differential diagnosis in the presence of a severe leukemoid response with multiple heterophilic precursors in avian species.