2001～2010年广州市鼠疫宿主动物及其媒介种类的监测及评价

目的分析广州市鼠疫宿主动物及其媒介的种群构成及数量分布情况,为制定鼠疫防控策略提供依据。方法采用夜笼法。在广州市12区、县级市设置监测点,对捕获鼠类及捡获蚤类进行鉴定,计算鼠密度;计算鼠带(染)蚤率和蚤指数;用鼠疫IHA法检测鼠疫F1抗体。结果 10年间共捕获鼠形动物8 891只,分属2目2科4属9种。其中啮齿目动物8 285只,食虫目动物606只,总鼠密度(捕获率)为11.25%;在1 185只鼠形动物中发现染蚤鼠243只,捡获蚤811只。发现蚤类4种,主要蚤种为印鼠客蚤;平均鼠染蚤率为20.51%,总蚤指数为0.68;未查出鼠疫F1抗体。结论未发现鼠间鼠疫流行迹象。褐家鼠仍是广州市主要鼠种。主要蚤种是印鼠客蚤。     

典型发达国家实验动物人道终点的选择

实验动物作为生命科学研究的重要实验材料,在达到科学目标和目的后必然涉及人道终点的选择,典型发达国家实验动物的法律法规相对完善,人道终点的选择也有具体的章法,研究典型发达国家实验动物法律法规中人道终点的选择和做法,对我国实验动物福利立法有启示作用.     

肾虚肝郁证迟发性性腺功能减退症大鼠模型的建立与评价

目的 建立“肾虚肝郁证”迟发性性腺功能减退症(Late onset hypogonadism,LOH)动物模型,并对其进行评价.方法 以中医理论“房劳过度伤肾”、“郁久伤肝”为指导,采用“退役种鼠(40周龄)+复合情志刺激+孤养”方法,建立“肾虚肝郁证”LOH动物模型,与正常组(8周龄)比较,以血清总睾酮、悬尾实验、睾丸间质细胞超微结构、睾酮合成相关酶以及Caspase-3 mRNA和蛋白表达为指标.结果 模型组大鼠出现一系列典型的LOH精神、心理、体能改变,与正常组比较,模型组大鼠血清总睾酮水平明显降低,悬尾不动时间显著延长,睾丸组织Caspase-3 mRNA和蛋白表达增强,睾酮合成相关酶类固醇激素合成急性调节蛋白(Steroidogenic Acute Regulatory Protein,StAR)[13]、细胞色素胆固醇侧链裂解酶(Cytochrome P450side-chain cleavage,P450scc)[14]、3β-羟甾脱氢酶(3beta-hydroxysteroid dehydrogenase,3β-HSD) mRNA和蛋白表达下降,差异均有统计学意义(P＜0.01);模型组睾丸间质变少,睾丸间质细胞线粒体数量减少,出现水肿,线粒体嵴消失.结论 “退役种鼠+复合情志刺激+孤养”方法复制“肾虚肝郁证”LOH模型切实可行,有较高的实用价值.     

The prevalence of colistin resistance in Escherichia coli and Klebsiella pneumoniae isolated from food animals in China: coexistence of mcr-1 and blaNDM with low fitness cost

Increasing colistin resistance is a global concern because colistin is used as a last resort for the treatment of carbapenem-resistant Enterobacteriaceae infections. The plasmid-mediated colistin resistance gene, mcr-1 was found in distinct bacterial species isolated from humans, animals, and the environment. In this study, farms in four different agricultural provinces in China were investigated to determine the occurrence of the antimicrobial resistance and related genes. A total of 373 Escherichia coli and 54 Klebsiella pneumoniae were isolated from 510 non-duplicated samples. Of the E. coli and K. pneumoniae isolates, 72.7% and 66.7%, respectively, were susceptible to colistin. Isolates resistant to colistin comprised 46.6% of the samples isolated from Shandong, and 17.8% and 16.4% of the samples from Jilin and Henan, respectively. Twenty-six carbapenem-resistant E. coli isolates were resistant to colistin, in which both mcr-1 and bla_NDM were present. Specifically, the co-existence was found in isolates from animals and sewage. Most of the resistance genes were located on plasmids and were 40–244 kilobases. Growth curves of transconjugants carrying mcr-1, bla_NDM-1, bla_NDM-4, bla_NDM-5, and bla_NDM-9 showed a low fitness cost compared with the recipient. In conclusion, mcr-1 was widespread in E. coli and K. pneumoniae isolated from farms in China. Co-existence of mcr-1 and bla_NDM-9 was identified in different sequence types of E. coli with low fitness cost from various origins, indicating an urgent need to take measures for decreasing dissemination.     

脊神经刺激诱导2型糖尿病大鼠模型的建立

目的探讨一种建立2型糖尿病大鼠模型的方法。方法选择雄性大鼠46只,随机分为2组。模型组23只大鼠在左侧T6～11椎间关节处,手术置入特制的硅胶片,制作胰腺自主神经刺激大鼠模型;对照组23只大鼠仅行左侧T6～11椎间关节处切开手术。普通饲养28～45 d,期间分别测定血糖和胰岛素浓度,实验结束腹腔麻醉取大鼠胰腺作β细胞内颗粒病理检查。结果模型组大鼠体质量增长变慢,血糖浓度显著高于对照组,胰岛素水平显著低于对照组（t=4.69～16.66,P〈0.05）。模型组大鼠胰腺β细胞内颗粒减少。结论脊神经刺激可诱导建立2型糖尿病大鼠模型,为中医推拿整脊治疗糖尿病提供了科学实验模型。     

长期应激对大鼠学习与记忆及纹状体边缘区c-Fos、c-Jun表达的影响

目的：探讨长期应激对大鼠学习、记忆及及纹状体边缘区即刻早期基因表达的影响.方法：将40只成年雄性SD大鼠分为两组：每组20只.应激组和对照组, 应激组大鼠持续暴露于应激原环境中达3周,用Morris水迷宫和Y 迷宫作业测试其空间学习与记忆成绩, 再应用免疫细胞化学方法检测c-Fos、c-Jun蛋白在纹状体边缘区内的表达.结果：（1）Morris水迷宫测试：应激组大鼠应激后寻找平台的潜伏期较对照组明显延长（P＜0.05）,Y迷宫测试：应激组大鼠寻找安全区的正确率明显低于对照组（P＜0.01）;（2）应激组纹状体边缘区c-Fos、c-Jun蛋白表达水平较对照组明显下调（P＜0.05）.结论：长期应激可减弱学习与记忆能力, 纹状体边缘区即刻早期基因表达变化可能是应激影响学习与记忆的机制之一.     

Safety,efficacy and toxicological evaluation of a novel,patented anti-diabetic extract of Trigonella Foenum-Graecum seed extract (Fenfuro)

Safety and anti-diabetic efficacy of a novel, proprietary Trigonella foenum-graecum seed extract [novel fenugreek extract (FE), Fenfuro?, CR0010810) enriched in furostanolic saponins (>60% w/w, HPLC) were assessed. Concerning safety, we undertook studies dealing with acute oral toxicity, 28-d sub-chronic toxicity and Ames’ bacterial reverse mutation assay that revealed no toxicity. Concerning efficacy, we examined beneficial effects of the extract on rats with type 2 diabetes (T2D). Male Sprague–Dawley rats received a high-fat diet for 2 weeks followed by streptozotocin (STZ, 35?mg/kg i.p.) to produce T2D. Seven days post-STZ, rats showing ≥300?mg/dl fasting plasma glucose level (PGL) were included in the study. FE (150- or 450- mg/kg p.o.) and glipizide (5?mg/kg p.o.) were administered once daily for 20?d and then twice daily for another 10?d (total 30?d). Blood samples were collected at 0, 10, 20 and 30?d of treatment and estimated for fasting plasma triglyceride (PTG), total cholesterol and insulin levels. After 30?d, FE and glipizide-treated diabetic animals were treated in combination with or without metformin (100?mg/kg) twice daily for another 10?d. FE did not influence body weight, feed and water intake. FE (150?mg/kg p.o.) reduced PTG levels in T2D rats by 22%, 24.6% and 29% at 10, 20 and 30?d of treatment, respectively, while glipizide (5?mg/kg p.o.) reduced the PTG levels by 57.4%, 46.2% and 39.4% at these time points. FE (450?mg/kg) treatment in STZ-induced diabetic rats produced significant hypoglycemic activity (approximately 31.5%) as compared to insulin (48.2% with 1 U/kg i.p.). FE (150?mg/kg p.o.) and metformin (100?mg/kg p.o.) combined produced significant reduction (20.7%) of PGL in T2D rats. No adverse effects were observed. We conclude after extensive in vitro and in vivo safety and efficacy studies that FE is safe and effective in treating T2D.     

The Impact of Nandrolone Decanoate in the Osseointegration of Dental Implants in a Rabbit Model: Histological and Micro-Radiographic Results

Despite high rates of osseointegration in healthy patients, complex cases present an increased risk of osseointegration failure when treated with dental implants. Furthermore, if immediate loading of the implants is used, maximizing the response of the host organism would be desirable. Anabolic steroids, such as Nandrolone Decanoate (ND), are reported to have beneficial clinical effects on various bone issues such as osteoporosis and bone fractures. However, their beneficial effects in promoting osseointegration in dental implant placement have not been documented. The study aimed to examine histological changes induced by ND in experimental dental implants in rabbit models. Two dental implants were placed in the tibias of 24 adult rabbits. Rabbits were allocated to one of two groups: control group or test group. Rabbits in the latter group were given nandrolone decanoate (15 mg/kg, immediately after implant placement and after 1 week). Micro-radiographic and histological analyses were assessed to characterize the morphological changes promoted by the nandrolone decanoate use. Total bone volume and fluorescence were significantly higher in the control group after 2 weeks. Such a difference between the two groups might indicate that, initially, nandrolone lengthens the non-specific healing period characteristic of all bone surgeries. However, after the beginning of the reparative processes, the quantity of newly formed bone appears to be significantly higher, indicating a positive stimulation of the androgen molecule on bone metabolism. Based on micro-radiology and fluorescence microscopy, nandrolone decanoate influenced bone regeneration in the implant site. The anabolic steroid nandrolone decanoate affects the healing processes of the peri-implant bone and therefore has the potential to improve the outcomes of implant treatment in medically complex patients.     

Here,There, and Everywhere: The Wide Host Range and Geographic Distribution of Zoonotic Orthopoxviruses

The global emergence of zoonotic viruses, including poxviruses, poses one of the greatest threats to human and animal health. Forty years after the eradication of smallpox, emerging zoonotic orthopoxviruses, such as monkeypox, cowpox, and vaccinia viruses continue to infect humans as well as wild and domestic animals. Currently, the geographical distribution of poxviruses in a broad range of hosts worldwide raises concerns regarding the possibility of outbreaks or viral dissemination to new geographical regions. Here, we review the global host ranges and current epidemiological understanding of zoonotic orthopoxviruses while focusing on orthopoxviruses with epidemic potential, including monkeypox, cowpox, and vaccinia viruses.