Effects of 2,5-hexanedione on angiogenesis and vasculogenesis in chick embryos

n-Hexane is widely used in industry and its metabolite, 2,5-hexanedione (2,5-HD), has been implicated as a neural toxin in the developing fetus. Using the chick embryo model, we have previously revealed the neurotoxicity of 2,5-HD during development and established that high dose of 2,5-HD was embryo lethal. In view of the close linkage in biology for neurogenesis and angiogenesis, we speculated that it was most likely caused by cardiovascular dysplasia, therefore in this study, we investigated the effects of 2,5-HD on the development of the vasculature, which involves vasculogenesis and angiogenesis. Using gastrulating chick embryos as a model, we demonstrated that the hemangioblasts (precursor of hematopoietic and endothelial cells) migrated to the area opaca where they form the blood islands. However, this process was impaired when the embryos were treated with 2,5-HD, suggesting that 2,5-HD is capable of impairing vasculogenesis. To study the effect of 2,5-HD exposure on angiogenesis, we used the chick yolk-sac membrane (YSM) and chorioallantoic membrane (CAM) models. We found that, at low (0.02 M) concentration, 2,5-HD stimulated angiogenesis while at higher concentrations (>0.1 M) it inhibited this process. This biphasic response of angiogenesis to 2,5-HD exposure was found to be associated with altered expression of the VEGF-R, FGF-2 and angiogenin. Moreover, we also determined that 2,5-HD exposure increased the reactive oxygen species (ROS) production. In conclusion, 2,5-HD could induce dysplasia in the developing vasculature, which in turn could cause extravascular hemolysis and the embryos to die.     

Where and what is the paralaminar nucleus? A review on a unique and frequently overlooked area of the primate amygdala

The primate amygdala is composed of multiple subnuclei that play distinct roles in amygdala function. While some nuclei have been areas of focused investigation, others remain virtually unknown. One of the more obscure regions of the amygdala is the paralaminar nucleus (PL). The PL in humans and non-human primates is relatively expanded compared to lower species. Long considered to be part of the basal nucleus, the PL has several interesting features that make it unique. These features include a dense concentration of small cells, high concentrations of receptors for corticotropin releasing hormone and benzodiazepines, and dense innervation of serotonergic fibers. More recently, high concentrations of immature-appearing cells have been noted in the primate PL, suggesting special mechanisms of neural plasticity. Following a brief overview of amygdala structure and function, this review will provide an introduction to the history, embryology, anatomical connectivity, immunohistochemical and cytoarchitectural properties of the PL. Our conclusion is that the PL is a unique subregion of the amygdala that may yield important clues about the normal growth and function of the amygdala, particularly in higher species.     

大型医院船岛礁巡诊中护理工作的组织管理

医院船是军队海上一线医院,战时执行以外科为主的救治任务,平时可用于突发事件、灾害医学救援及为海上卫勤训练或为教学提供平台。现将岛礁巡诊中护理工作组织实施体会报告如下。     

西沙群岛恙螨所携恙虫病东方体的序列分析

目的　用分子生物学技术鉴定西沙群岛恙虫病东方体的基因序列 ,探讨南海岛屿恙虫病疫源地的形成。方法　以巢式聚合酶链反应 (NPCR)检测西沙群岛恙螨所携恙虫病东方体的 5 6kDa蛋白基因片段 ,继而将NPCR产物克隆进pGEM-T载体并且测序 ,测序结果在国际互联网作多序列比较和进化树分析。结果　从西沙群岛收集的恙螨扩增出 5 0 7bp目的片段 ,序列分析证实与Karp株同源性 85 % ,与Gilliam株同源性 6 8% ,与Yonchon株同源性 6 7% ,与Kato株同源性 6 5 %。结论　西沙群岛的恙螨携带恙虫病东方体以Karp型为主。     

An inconsistent relationship between insulin and blood pressure in three Pacific Island populations

The evidence linking insulin to blood pressure is controversial, and results for groups similarly categorized by body mass, ;glucose tolerance and hypertensive status are often contradictory. We have investigated the relationship in three. population-based samples of Micronesian (Nauru), Polynesian (Western Samoa) and Melanesian (New Caledonia) Pacific islanders, who are known to be susceptible to obesity, non-insulin-dependent diabetes mellitus (NIDDM), hyperinsulinaemia and hypertension. After controlling for age and body mass index (BMI); mean fasting and 2-hr (post 75 g glucose) insulin levels were not significantly different between hypertensive and non-hypertensive subjects, in any population or glucose tolerance sub-group, excepting 2-hr insulin in New Caledonians with normal glucose, tolerance. Similarly, there were no strong trends for a higher prevalence of hypertension amongst those with insulin levels in the upper quartile of the distribution for each population, although it was apparent in some BMI/glucose tolerance sub-groups of two populations. Multiple linear regression analyses also showed an inconsistent and where: present, weak, independent association between insulin and blood pressure in models predicting, both systolic and diastolic blood pressures. We therefore conclude that the hypothesis implicating insulin as a major determinant of blood pressure and as the pathophysiological link between obesity, NIDDM and hypertension is not strongly supported either by the literature or the present data.     

改良的新生猪胰岛细胞体外培养

介绍一种通过细胞分离及体外培养获得大量新生猪胰岛细胞团的方法。新生猪胰腺经 0 .5～ 1mg .ml- 1的V型胶原酶消化 8～ 1 2min ,再经体外培养 7d ,可获大量纯化的胰岛细胞团。同时 ,新生猪胰岛内的B细胞不仅胰岛素分泌功能良好 ,而且其超微结构正常。提示新生猪胰岛细胞可作为异种移植治疗 1型糖尿病重要的供体来源。     

人肝癌细胞系Slit/Robo启动子甲基化状态及基因表达的研究

目的 研究Slit/Robo信号通路相关基因Slit1、Slit2、Slit3和Robo1、Robo3在多种人肝癌细胞系中的表达及甲基化状态,探讨与肝癌发生和发展的关系. 方法提取9种人肝细胞癌细胞株(Hep3B、HepG2、PLC/PRF/5/PRF/5、SMMC-7721、BEL-7402、MHCC97-H,MHCC97-L、LM3、LM6)及对照细胞株L02的基因组DNA和总RNA,采用半定量逆转录聚合酶链反应技术和甲基化特异性聚合酶链反应技术检测Slit1、Slit2,Slit3和Robo1,Robo3基因的基因表达水平与启动子甲基化状态.实验数据应用Paired t检验. 结果 Slit1、Slit2、Slit3基因除个别细胞株外,在不同转移潜能细胞株中均发生了DNA甲基化,同时Slit1和Slit3在mRNA水平几乎均不表达,Slit2基因表达程度在不同转移潜能的细胞株之间存在差异,随着转移潜能的增加表达大致呈下降趋势.作为Slit2受体的Robo1基因在10株肝癌细胞株中均发生甲基化修饰,但除在SMMC-7721、BEL-7402、L02不表达外,其余7种细胞株均有表达.Robo3基因相关CpG岛在9种肝癌细胞株中均未发生甲基化,同时其在mRNA水平均无表达. 结论 Slit/Robo可能在肝癌发生和发展中发挥作用.而Robo3则在肝癌中不发生表达而且其表达沉默可能不受甲基化方式调控.