High reinforcing efficacy of nicotine in non-human primates

Although tobacco appears highly addictive in humans, there has been persistent controversy about the ability of its psychoactive ingredient nicotine to induce self-administration behavior in laboratory animals, bringing into question nicotine's role in reinforcing tobacco smoking. Because of ethical difficulties in inducing nicotine dependence in na?ve human subjects, we explored reinforcing effects of nicotine in experimentally-naive non-human primates given access to nicotine for periods of time up to two years. Five squirrel monkeys with no experimental history were allowed to intravenously self-administer nicotine by pressing one of two levers. The number of presses on the active lever needed to obtain each injection was fixed (fixed-ratio schedule) or increased progressively with successive injections during the session (progressive-ratio schedule), allowing evaluation of both reinforcing and motivational effects of nicotine under conditions of increasing response cost. Over time, a progressive shift toward high rates of responding on the active lever, but not the inactive lever, developed. The monkeys' behavior was clearly directed toward nicotine self-administration, rather than presentation of environmental stimuli associated with nicotine injection. Both schedules of reinforcement revealed a high motivation to self-administer nicotine, with monkeys continuing to press the lever when up to 600 lever-presses were needed for each injection of nicotine. Thus, nicotine, by itself, in the absence of behavioral or drug-exposure history, is a robust and highly effective reinforcer of drug-taking behavior in a non-human primate model predictive of human behavior. This supports the use of nicotinic ligands for the treatment of smokers, and this novel preclinical model offers opportunities to test future medications for the treatment of nicotine dependence.     

Expression,purification and characterization of anti-BAFF antibody secreted from the yeast <Emphasis Type="Italic">Pichia pastoris</Emphasis>

B-Cell activating factor (BAFF) is critical for B cell survival and maturation; excessive expression of it corrupts B-cell tolerance and may lead to autoimmunity. The gene, scFv-Fc, coding for the antibody of BAFF was inserted into the eukaryotic expression vector, pPICZαA, and transformed into Pichia pastoris. A high-level expression strain was obtained using a ‘yeastern blotting’ method. The scFv-Fc antibody was purified and 56 mg was obtained from 1 l of culture supernatant. It retained high binding activity to both soluble BAFF and membrane-bound BAFF.     

Development and function of CD94-deficient natural killer cells

The CD94 transmembrane-anchored glycoprotein forms disulfide-bonded heterodimers with the NKG2A subunit to form an inhibitory receptor or with the NKG2C or NKG2E subunits to assemble a receptor complex with activating DAP12 signaling proteins. CD94 receptors expressed on human and mouse NK cells and T cells have been proposed to be important in NK cell tolerance to self, play an important role in NK cell development, and contribute to NK cell-mediated immunity to certain infections including human cytomegalovirus. We generated a gene-targeted CD94-deficient mouse to understand the role of CD94 receptors in NK cell biology. CD94-deficient NK cells develop normally and efficiently kill NK cell-susceptible targets. Lack of these CD94 receptors does not alter control of mouse cytomegalovirus, lymphocytic choriomeningitis virus, vaccinia virus, or Listeria monocytogenes. Thus, the expression of CD94 and its associated NKG2A, NKG2C, and NKG2E subunits is dispensable for NK cell development, education, and many NK cell functions.     

The Chemokine CXCL13 Is a Prognostic Marker in Clinically Isolated Syndrome (CIS)

Background

There is increasing recognition of the importance of B lymphocytes in the immunopathogenesis of multiple sclerosis (MS), encouraging the evaluation of B cell-associated biomarkers in the cerebrospinal fluid (CSF). We aimed to evaluate the relevance of the B cell chemoattractant CXCL13 as a prognostic marker in patients with clinically isolated syndrome (CIS) regarding conversion to MS, and to compare it to Barkhof criteria in magnetic resonance imaging (MRI), oligoclonal bands (OCB) and the polyspecific intrathecal B cell response against measles, rubella and varicella zoster virus (MRZR).

Methodology/Principal Findings

CXCL13 was determined in a prospective study over 2 years including 46 patients that remained CIS over follow-up (CIS-CIS), 45 patients that developed MS (CIS-RRMS), and 30 controls using ELISA. CSF CXCL13 was significantly elevated in CIS-RRMS as compared to CIS-CIS and controls (p<0.001). It was significantly elevated in CIS with OCB (p<0.001), positive MRZR (p = 0.04), and gadolinium enhancement in MRI (p = 0.02) and showed a significant correlation with CSF leukocyte count (p<0.001) and QIgG (p<0.001). CXCL13 showed the best positive predictive value (PPV) of all parameters investigated (70%, 95%-CI: 53–84%), which could be further increased by combination with Barkhof criteria in MRI (80%).

Conclusions/Significance

Our data indicate the relevance of CXCL13 in CIS to predict conversion to MS. It furthermore shows CXCL13 to be an important mediator in the inflammatory cascade associated with the polyspecific intrathecal B cell response that manifests itself in OCB and MRZR.     

黑木耳多糖对急性脑缺血/再灌注损伤影响的研究

目的:观察黑木耳多糖(APP)对急性脑缺血大鼠的保护作用并探讨其相关机制。方法:成年雄性SD大鼠给予不同浓度的AAP灌胃20d,每天1次,腹腔注射银杏叶提取物(ginkgo biloba extract,EGb671)作为阳性对照,20d后实施右侧大脑中动脉栓塞(MCAO)建立局灶性脑缺血模型。MCAO60min后复灌,复灌24h后进行Longa神经功能损伤评分,并用2,3,5-氯化三苯基四氮唑(TTC)染色法测定脑梗死面积。复灌48h后用TUNEL免疫组化检测神经元凋亡,测定脑组织线粒体内活性氧簇(ROS)的生成量判断氧化应激水平。结果:黑木耳多糖能降低神经功能损伤评分,减小脑梗死面积,减少神经元凋亡,并且能够使缺血复灌脑组织线粒体ROS生成显著减少。高剂量AAP组的凋亡神经元数量、ROS生成量和阳性对照组相比有显著性差异。结论:黑木耳多糖能够对抗大鼠的局灶性脑缺血损伤,其保护作用和减轻氧化应激水平有关,并优于银杏叶提取物。     

Cytotoxic T lymphocyte epitopes from human heparanase can elicit a potent anti-tumor immune response in mice

Heparanase is expressed in almost all advanced tumors, and therefore it may serve as a potential target for tumor therapy. Our previous study has shown that heparanase can serve as a potential universal tumor-associated antigen (TAA) for the immunotherapy of advanced tumors. Further study demonstrated that the HLA-A*0201-restricted Cytotoxic T lymphocytes (CTL) epitopes Hpa525 (PAFSYSFFV), Hpa277 (KMLKSFLKA) and Hpa405 (WLSLLFKKL) from human heparanase could induce a potent anti-tumor immune response in vitro. The present study was designed to investigate whether the above peptides could induce immune responses in mice. Our results demonstrated that the effectors from heparanase peptide-immunized mice could effectively lyse various tumor cells that were heparanase positive and HLA-A*0201 matched. We also found that these peptide-specific CTLs did not lyse autologous lymphocytes that had low heparanase activity. Further study revealed that Hpa525, Hpa277, and Hpa405 peptides increased the frequency of IFN-γ-producing T cells as compared to a negative peptide. These results suggest that Hpa525, Hpa277, and Hpa405 peptides are novel HLA-A*0201-restricted CTL epitopes capable of inducing heparanase-specific CTLs in mice. Because heparanase is expressed in most advanced malignant tumors, Hpa525, Hpa277, and Hpa405 peptide-based vaccines may be useful for the immunotherapy of patients with advanced tumors.     

具钩竖毛螯石蛾(毛翅目,螯石蛾科)幼虫的线粒体DNA鉴定和记述

测定和分析了具钩竖毛螯石蛾成虫和幼虫及黄氏竖毛螯石蛾成虫的mtDNA-COⅠ、Ⅱ及tRNA-Leu基因序列,发现具钩竖毛螯石蛾成虫与幼虫的序列歧异度为1%,而具钩竖毛螯石蛾的成、幼虫与黄氏竖毛螯石蛾成虫的序列歧异度为14%和13%.对我国特有种具钩竖毛螯石蛾幼虫的形态特征进行了描述.     

编码流感病毒血凝素基因和CD40L的核酸疫苗抗小鼠流感研究

为了检测表达CD40L的质粒能台作为核酸疫苗佐剂提高A／PR8／34流感病毒血凝素(HA)DNA疫苗的免疫应答,构建了表达鼠CD40L的质粒,行将它与A型流感病毒的HADNA疫苗用电击的方法共同免疫BALB／C小鼠(各30μg),免疫两次,间隔三周,第二次免疫后1周,用致死量流感病毒A／PR8／34攻击。发现与单独免疫30μgHA相比,血清中抗HA的IgG抗体节明显提高,且以IgG2a抗体提高为主,小鼠体重减轻非常少且体重恢复加快。实验结果显示,CD40L能作为流感病毒核酸疫苗佐剂,提高小鼠抗流感病毒攻击的能力。