大肠杆菌细胞的软X射线显微成像研究

软X射线显微术是研究含水甚至活性生物样品的有力工具。相对于光学显微镜 ,它具有更高的成象分辨率 ;相对于电子显微镜 ,它的样品制备简单—无须对样品进行脱水、染色和超薄切片等。报道的是利用合肥同步辐射X射线源和接触显微成象技术 ,对自然状态下含水的完整XL1 blueMRF′细菌细胞进行显微成象研究。从获得的显微图象中可以看出一些新的现象。含有DNA、蛋白质的拟核以及中体对波长 2 .4nmX射线具有较弱的吸收能力 ;不少细菌细胞的两端对 2 .4nm波长的X射线的吸收也具有很大的差异。这些有趣现象产生的根本原因和生物学意义有待进一步研究。     

辽宁地区普通级和SPF级Wistar大鼠血液生化指标检测

目的建立本省、本地区实验动物生理指标数据背景资料,为科学研究和新药安全性评价提供准确、可靠、科学的参考依据。方法普通级、SPF级Wistar大白鼠（6～8周龄）各60只,雌雄各半,腹主动脉采血,用全自动生化分析仪及配套试剂盒检测血液生化指标。结果普通级Wistar大白鼠的ALT、ALP、CHO、CK、CRE雌雄之间差异显著（P〈0．05或P〈0．01）;SPF级Wistar大白鼠的ALB、ALT、ALP、CHO、BUN、CK、AST、GLU、TBIL雌雄之间差异显著（P〈0．05或P〈0．01）;普通级与SPF级Wistar大白鼠的ALT、ALP、TP、BUN、TBIL、CRE、CHO、CK、AST、ALB、GLU差异显著（P〈0．01）。结论本研究的结果证明普通级与SPF级Wistar大白鼠的血液生化指标差异显著,多数生化指标雌雄之间存在显著差异,为应用提供了有价值的参数。     

Hypoderma actaeon: an emerging myiasis in roe deer (Capreolus capreolus)

Subcutaneous larvae of Hypoderma spp. (Diptera: Oestridae) were detected in the dorsal region in 10 roe deer, Capreolus capreolus (Artiodactyla: Cervidae), hunted in central Spain between January and March 2016. All larvae were found in the inner side of the hide during the skinning of the animals. The study of the morphological features of eight larvae of different stages collected from two animals allowed the identification of Hypoderma actaeon Brauer. The small size (4–5 mm) of some of the first instars suggests that the internal lifecycle of H. actaeon may be exclusively subcutaneous. This is the first confirmation of H. actaeon in roe deer; however, further studies to assess the spread of the parasite and to follow the evolution of this myiasis in roe deer are needed.     

冬葵果多糖的抗氧化作用研究

研究冬葵果多糖(Fructus Malvae polysaccharides,FMP)对氧自由基的清除作用及对脂质过氧化的抑制作用。采用分光光度法测定FMP清除Fenton体系产生的羟自由基(.OH)、邻苯三酚自氧化体系产生的超氧阴离子自由基(O2-.)的能力及评价对Fe(Ⅱ)-H2O2体系(.OH)诱导的脂质过氧化终产物丙二醛(MDA)的抑制作用。结果显示,在化学模拟体系中,冬葵果多糖对.OH具有很强的清除作用,与VC比较达到显著水平(P<0.01),对O2-.的清除能力与VC相当。在体外,多糖浓度达到1.72 mg/mL可明显降低MDA的含量,与空白液比较达到显著水平(P<0.01)。以上结果表明,FMP具有明显的抗氧化活性。     

北京市不同植物群落的降温增湿效应研究

在北京市植物园选取14个不同结构特征的植物群落作为研究对象,利用温湿度记录仪对其温湿度进行测定,分别研究郁闭度、平均冠幅、叶面积指数与降温增湿效应之间的相关性。结果表明,不同群落的降温增湿效果存在较大差异:碧桃(Prunus persica Batsch.var.duplex)、洋白蜡(Fraxinus pennsylvanica)、杂种鹅掌楸(Liriodendron chinense×tulipifera)、杜仲(Eucommia ulmoides)群落的降温增湿效果较好,而绦柳(Salix matsudana f.pendula)、楸树(Catalpa bungei)、毛泡桐(Paulownia tomentosa)群落的降温增湿效果相对较弱。对实验数据进行统计分析可知,郁闭度与群落降温效应呈极显著正相关,与增湿效应呈正相关但不显著;平均冠幅与群落的降温效应呈显著正相关,但与增湿效应的正相关并不显著;叶面积指数对群落的降温效应起到一定促进作用,但对增湿效应影响不大。除此之外,其他影响植物群落降温增湿效应的结构特征有待进一步探讨。     

Prostaglandin E2 inhibits eosinophil trafficking through E-prostanoid 2 receptors

The accumulation of eosinophils in lung tissue is a hallmark of asthma, and it is believed that eosinophils play a crucial pathogenic role in allergic inflammation. Prostaglandin (PG) E(2) exerts anti-inflammatory and bronchoprotective mechanisms in asthma, but the underlying mechanisms have remained unclear. In this study we show that PGE(2) potently inhibits the chemotaxis of purified human eosinophils toward eotaxin, PGD(2), and C5a. Activated monocytes similarly attenuated eosinophil migration, and this was reversed after pretreatment of the monocytes with a cyclooxygenase inhibitor. The selective E-prostanoid (EP) 2 receptor agonist butaprost mimicked the inhibitory effect of PGE(2) on eosinophil migration, whereas an EP2 antagonist completely prevented this effect. Butaprost, and also PGE(2), inhibited the C5a-induced degranulation of eosinophils. Moreover, selective kinase inhibitors revealed that the inhibitory effect of PGE(2) on eosinophil migration depended upon activation of PI3K and protein kinase C, but not cAMP. In animal models, the EP2 agonist butaprost inhibited the rapid mobilization of eosinophils from bone marrow of the in situ perfused guinea pig hind limb and prevented the allergen-induced bronchial accumulation of eosinophils in OVA-sensitized mice. Immunostaining showed that human eosinophils express EP2 receptors and that EP2 receptor expression in the murine lungs is prominent in airway epithelium and, after allergen challenge, in peribronchial infiltrating leukocytes. In summary, these data show that EP2 receptor agonists potently inhibit eosinophil trafficking and activation and might hence be a useful therapeutic option in eosinophilic diseases.     

三种杜拉属（Drawida）蚯蚓的酯酶同工酶的初步研究

应用聚丙烯酰胺凝胶电泳的方法，对寡毛纲杜拉属三种蚯蚓进行酯酶同工酶酶谱分析。其结果表明，同属蚯蚓具有几条相似的酶谱区带，而不同种蚯蚓又具有各自独特的酶谱带，种间酶谱区带数目、泳动率及染色强度都有明显区别。雅和杜拉蚓酶谱图和天锡杜拉蚓相似，而与管状杜拉蚓相差较远，表明同属蚯蚓在进化水平上的亲缘关系。     

Formation of cysteinyl-containing leukotrienes by human arterial tissues

Human arterial rings incubated in modified Tyrode solution released small amounts of leukotriene (LT) C4-like material spontaneously and larger amounts upon stimulation with the ionophore A23187 as determined by radioimmunoassay. By reversed phase high pressure liquid chromatography (HPLC) LTC4-like material was found to comigrate with authentic LTC4, LTD4 and LTE4. Nordihydroguaiaretic acid (NDGA) significantly inhibited the ionophore A23187-induced release of LTC4-like material, while indomethacin was without effect. Simultaneously the arterial rings released much larger amounts of 6-keto-prostaglandin (PG) F1 alpha, which were significantly decreased by indomethacin. The results demonstrate that human arterial tissue has the capacity to synthesize cysteinyl-containing LT from endogenous arachidonic acid.     

Laropiprant Attenuates EP3 and TP Prostanoid Receptor-Mediated Thrombus Formation

The use of the lipid lowering agent niacin is hampered by a frequent flush response which is largely mediated by prostaglandin (PG) D(2). Therefore, concomitant administration of the D-type prostanoid (DP) receptor antagonist laropiprant has been proposed to be a useful approach in preventing niacin-induced flush. However, antagonizing PGD(2), which is a potent inhibitor of platelet aggregation, might pose the risk of atherothrombotic events in cardiovascular disease. In fact, we found that in vitro treatment of platelets with laropiprant prevented the inhibitory effects of PGD(2) on platelet function, i.e. platelet aggregation, Ca(2+) flux, P-selectin expression, activation of glycoprotein IIb/IIIa and thrombus formation. In contrast, laropiprant did not prevent the inhibitory effects of acetylsalicylic acid or niacin on thrombus formation. At higher concentrations, laropiprant by itself attenuated platelet activation induced by thromboxane (TP) and E-type prostanoid (EP)-3 receptor stimulation, as demonstrated in assays of platelet aggregation, Ca(2+) flux, P-selectin expression, and activation of glycoprotein IIb/IIIa. Inhibition of platelet function exerted by EP4 or I-type prostanoid (IP) receptors was not affected by laropiprant. These in vitro data suggest that niacin/laropiprant for the treatment of dyslipidemias might have a beneficial profile with respect to platelet function and thrombotic events in vascular disease.     

Monoclonal antibodies against E- and F-type prostaglandins. High specificity and sensitivity in conventional radioimmunoassays

Polyclonal antisera against prostaglandins (PGs) are widely used for the assessment of the biological role of these mediators, but even the most specific contain antibodies against the major metabolites and degradation products of the haptens employed. To overcome this inherent problem we produced monoclonal antibodies (mAs) against PGE2, PGF2 alpha and 6-keto-PGF1 alpha using the somatic cell hybridization technique. The mAs against 6-keto-PGF1 alpha and PGF2 alpha proved to be highly specific, but allowed only for moderate detection limits (1-2 ng) in conventional fluid phase radioimmunoassays (RIAs). One of the mAs against PGE2 permitted a 100-fold improvement in the detection limit while being almost devoid of cross-reactivity with metabolites and other structurally related PGs. These results show that highly specific mAs against PGs can be produced to improve the available RIA technique for PG quantification.