In vivo kinetics and displacement study of a carbon-11-labeled hallucinogen,N,N-[11C]dimethyltryptamine

The endogenous hallucinogen, N,N-dimethyltryptamine (DMT), was labeled with carbon-11 and its regional distribution in rat brain studied. [¹¹C]DMT showed higher accumulation in the cerebral cortex, caudate putamen, and amygdaloid nuclei. Studies of the subcellular distribution of [¹¹C]DMT revealed the specific localization in the fractions enriched with serotonin receptors only when a very low dose was injected into rats. The proportions of the radioactivity in receptor-rich fractions were greatly enhanced by pretreatment with the monoamine oxidase inhibitor, pargyline. Specific binding of [¹¹C]DMT to serotonin receptors in dog brain was demonstrated by a positron emission tomographic study in which 5-methoxy-N,N-dimethyltryptamine caused approximately 20% displacement of the radioligand from the receptors.     

Bacterial ghosts (BGs)—Advanced antigen and drug delivery system

Bacterial ghosts (BGs) are empty bacterial envelopes of Gram-negative bacteria produced by controlled expression of cloned gene E, forming a lysis tunnel structure within the envelope of the living bacteria. BGs are devoid of cytoplasmic content and possess all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat. BGs are ideally suited as an advanced drug delivery system (ADDS) for toxic substances in tumor therapy. The inner space of BGs can be loaded with either single components or combinations of peptides, drugs or DNA which provides an opportunity to design new types of (polyvalent) drug delivery vehicles. Uptake of BGs loaded with Doxorubicin (Dox) by CaCo2 cells led to effective Dox release from endo-lysosomal compartments and accumulation in the nucleus. Viability and proliferative capacity of the cells were significantly decreased (2–3 orders of magnitude) after internalization of Dox loaded BGs as compared to cells incubated with free Dox. The same effect was observed with leukemia cells. Melanoma cells also revealed a high capability to internalize BGs. These results indicate that BGs are able to target a range of types of cancer. BGs have also been investigated as DNA delivery vectors. Studies show DNA loaded BGs are efficiently phagocytosed and internalized by both professional APCs and tumor cells with up to 82% of cells expressing the plasmid-encoded reporter gene. Our studies with BGs as an ADDS system contribute (i) to optimize drug delivery for the treatment of cancer; (ii) define specific conditions for selection and preparation of BG formulations; (iii) and provide a background for the clinical application of BGs in cancer therapy.     

Beyond C4d: Other Complement-Related Diagnostic Approaches to Antibody-Mediated Rejection

Complement is a multifunctional system of receptors and regulators as well as effector molecules. Both the pathogenic and diagnostic power of complement is based on the capacity of the complement system to amplify innate and adaptive immunity. This amplification is accomplished through two strategies: (1) enzymatic reactions in the complement cascade, and (2) stimulation of leukocytes, platelets and parenchymal cells through specific receptors or receptor-independent pore formation. The mechanisms by which complement mediates and modifies nonspecific inflammation, antibody-mediated injury and T-cell responses are of particular significance to the pathogenesis of transplant rejection. Understanding the mechanisms by which complement integrates the interactions of leukocytes, platelets and parenchymal cells offers opportunities to further refine the diagnosis of rejection.     

小干扰RNA干扰大鼠神经元Nogo受体mRNA表达的实验研究

目的观察大鼠Nogo受体(NgR)特异性小干扰RNA(small interfering RNA,siRNA)在原代神经元干扰其mRNA表达的效果。方法体外培养大鼠原代皮层和海马细胞,应用阳离子脂质体转染试剂转染4对化学合成的大鼠NgR特异性siRNA,72h后提取细胞总RNA,实时荧光定量RT-PCR检测NgR mRNA表达情况。结果4对siRNA均能够下调靶基因NgR的mRNA表达水平,siNgR199、siNgR562、siNgR772和siNgR964等干扰后,NgR mRNA的表达分别为对照siRNA干扰组的6.5%、62.4%、15.2%和6.86%,与对照siRNA干扰组比较有统计学意义(P<0.05)。结论化学合成的NgR特异性siRNA能够有效的干扰大鼠原代皮层和海马细胞内NgR基因mRNA的表达水平。     

湖北人群Toll样受体4基因多态性研究

目的 研究湖北人群Toll样受体4(TLR4)Asp299Gly和Thr399Ile基因多态性分布特征。方法 采用等位基因特异性聚合酶链反应(ASPCR)-限制酶片断长度多态性(RFLP)检测TLR4 Asp299Gly和Thr399 Ile基因多态性。结果 在所有的253例中国湖北人群样本中，没有检测到TLR4 Asp299Gly和Thr399Ile基因多态性存在。结论 TLR4基因多态性在不同地区和人群发生的频率是不同的，与白种人相比，中国湖北人群的TLR4Asp299G1y和Thr399Ile的基因多态性非常罕见。     

雌激素及其受体与胆囊癌关系的研究现状及进展

目的:探讨并讨论雌激素及其抗体与胆囊癌的关系.方法:阅读关于雌激素和胆囊癌方面的文献并进行总结.结果:雌激素在胆囊癌转变过程中起极为重要的作用.结论:研究胆囊癌患者血清中的雌激素水平对胆囊癌的发生、发展、预后及指导相应临床内分泌治疗具有重要的理论意义.     

Cerebral type 2 astroglia are heterogeneous with respect to their ability to respond to neuroligands linked to calcium mobilization.

Very little information is available concerning the pharmacology of type 2 astroglia. During the past decade it has become apparent that two distinct lineages of astroglial cells can be defined in vitro. These two lineages are commonly referred to as type 1 and type 2 and are distinguished from each other on the basis of their morphological features and antigenic phenotypes. In contrast to type 1 astroglia, very little is known about the pharmacology of type 2 astroglia. The lack of information concerning the responsiveness of these cells stems primarily from difficulties encountered in isolating large numbers of type 2 astroglia free of other cell types. In the present study video- and photometer-based imaging systems were used to monitor the influence of a series of neuroligands on the intracellular calcium levels of individual cerebral type 2 astroglia in order to assess their expression of calcium-mobilizing receptors. The responses of 85 immunocytochemically identified cerebral type 2 astroglia to bradykinin (BK), norepinephrine (NE), histamine (HIST), carbachol (CARB), 2-methyl-thio ATP (2MT-ATP), glutamate (GLUT), and serotonin (5-HT) were analyzed. Approximately 50% of cerebral type 2 astroglia responded to BK, NE, HIST, CARB, and 2MT-ATP whereas only 16% and 9% of the cells responded to GLUT and 5-HT, respectively. The number of neuroligands that increased calcium in individual cells ranged from 0 to 6. These responses are quite similar to those previously demonstrated in cultured cerebral type 1 astroglia. No pattern of receptor co-expression was observed for the different neuroligands tests.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantification of the expression level of integrin receptor alpha(v)beta3 in cell lines and MR imaging with antibody-coated iron oxide particles.

Targeted imaging requires site-specific accumulation of a contrast agent (CA), and the properties of that agent must be selected according to the abundance of the target to obtain a signal above the detection limit of the instrument. However, numerical estimates of receptors per cell are rarely found in the literature. Integrin receptors would be particularly promising targets because of their accessibility from the blood stream and expression on activated neovascular endothelial cells. We systematically estimated the number of integrin receptors of cell lines and primary cells by flow cytometry analysis. Since integrin receptors are heterodimeric molecules, and alpha(v) forms complexes with various beta subunits, the numbers of alpha(v) and beta(3) subunits are therefore dissimilar. The observed values are 3 . 10(3)-1.4 . 10(4)/cell for alpha(v), and 5.3 . 10(2)-1.1 . 10(4)/cell for beta(3). Despite the low number of exposed receptors, we show that up to single-cell MR visualization can be achieved with the use of iron oxide beads complexed with antibodies as CAs.     

性别差异对脓毒症大鼠肝脏Toll样受体4和髓样分化蛋白-2基因表达的影响

目的探讨性别差异对脓毒症大鼠肝脏组织Toll样受体4(TLR4)和髓样分化蛋白- 2(MD-2)基因表达的影响。方法以脂多糖(LPS)按5 mg/kg体重由大鼠腹腔注射制作脓毒症动物模型,注射后2 h留取肝脏组织检测TLR4、MD-2和肿瘤坏死因子-α(TNF-α)基因表达,同时测定各组大鼠血浆中丙氨酸氨基转移酶(ALT)及雌二醇含量。结果正常雌雄性大鼠肝脏组织均可表达少量TLR4、MD-2、TNF-α基因,其中雌性组分别为0．175±0．034、0．211±0．044、0．201±0．068; 雄性组分别为0．205±0．061、0．243±0．049、0．243±0．063,两组数据差异无统计学意义(P> 0．05),但LPS刺激后雌性大鼠肝脏组织上述指标分别为0．615±0．089、0．708±0．181、0．730± 0．118,血浆中ALT含量为(81．07±10．72)U／L;雄性组分别为0．723±0．091、1．123±0．272、 0．881±0．156,ALT含量为(106．39±14．21)U／L,雌性组各项指标均明显低于雄性大鼠(P< 0．05)。相关分析表明雌性及雄性脓毒症大鼠肝脏组织TLR4及TNF-α基因表达与相应性别大鼠血浆中雌二醇含量呈显著负相关(P<0．05)。结论 LPS刺激后大鼠肝脏组织TLR4、MD-2及 TNF-α基因表达存在性别差异,内源性雌激素的作用可能导致雌性脓毒症大鼠肝脏组织损伤较雄性轻。     

蛋白酶激活受体1介导人肺上皮细胞分泌白细胞介素-8

目的探讨蛋白酶激活受体1（PAR1）激动肽和凝血酶对人肺上皮细胞白细胞介索-8（IL-8）分泌的影响。方法人肺上皮细胞系A549细胞分别接种于12孔培养板各孔内，并分别用不同浓度的PAR1激动肽SFLLR和反PAR1激动肽RLLFS以及不同浓度的凝血酶和／或凝血酶抑制剂水蛭索进行刺激，刺激时间为2和16h。用ELISA方法检测上清液中的IL-8水平。结果经过16h的培养，SFLLR可引起浓度相关性IL-8的释放增加，增加到300μmol/L时诱导IL-8的释放量比基础分泌量增加了近16倍，RLLFS不能引起IL-8的释放增加。凝血酶也可引起浓度相关性IL-8释放．凝血酶在浓度1kU／L时就可引起IL-8释放量增加，10kU/L时诱导IL-8释放量达高峰，为基础分泌量的7．5倍。水蛭索可以抑制凝血酶对IL-8的释放作用。时间相关曲线表明，PAR1介导的IL-8释放从2h起即可引起增加，16h达高峰。结论PAR1激动肽和凝血酶可促进人肺上皮细胞分泌IL-8，PAR1拮抗剂和凝血酶抑制剂可能具有抗炎作用。