Amplified Fragment Length Polymorphism Analysis of Campylobacter jejuni Strains Isolated from Chickens and from Patients with Gastroenteritis or Guillain-Barré or Miller Fisher Syndrome

The high-resolution genotyping method of amplified fragment length polymorphism (AFLP) analysis was used to study the genetic relationships between Campylobacter jejuni strains infecting chickens (n = 54) and those causing gastroenteritis in humans (n = 53). In addition, C. jejuni strains associated with the development of Guillain-Barré syndrome (GBS) (n = 14) and Miller Fisher syndrome (MFS) (n = 4), two related acute paralytic syndromes in human, were included. Strains were isolated between 1989 and 1998 in The Netherlands. The AFLP banding patterns were analyzed with correlation-based and band-based similarity coefficients and UPGMA (unweighted pair group method using average linkages) cluster analysis. All C. jejuni strains showed highly heterogeneous fingerprints, and no fingerprints exclusive for chicken strains or for human strains were obtained. All strains were separated in two distinct genetic groups. In group A the percentage of human strains was significantly higher and may be an indication that genotypes of this group are more frequently associated with human diseases. We conclude that C. jejuni from chickens cannot be distinguished from human strains and that GBS or MFS related strains do not belong to a distinct genetic group.     

安徽东至华龙洞古人类遗址哺乳动物化石的初步研究

华龙洞遗址发现于2004年,先后于2006和2014～2017年进行了5次发掘,期间发现了若干古人类化石和大量哺乳动物化石;本文是对2014～2016年出土哺乳动物化石的初步研究成果。目前已鉴定出8目24科43种(含未定种)哺乳动物,其中以偶蹄类化石最丰富。化石保存状况较差,以碎骨为主,牙齿较少,完整骨骼更少;但骨骼上鲜见啮齿类啮咬痕迹。华龙洞动物群与南京汤山猿人遗址、和县猿人遗址及重庆盐井沟等动物群较为相似,尤其是与和县猿人遗址及南京猿人遗址动物群最为接近,主要表现在如下方面:1)都含古人类化石;2)都不含第三纪动物群的孑遗分子;3)都含有大熊猫-剑齿象动物群的主要成员(大熊猫、剑齿象、巨貘及猪獾等),同时也都含一定量的北方属种,但华龙洞含北方成分相对较少,只发现翁氏麝鼩、麝鼹、变异仓鼠、布氏毛足田鼠、棕熊、李氏野猪、葛氏斑鹿及大角鹿等,华龙洞的大角鹿是该属分布最靠南的地点;4)都含有剑齿象而不含晚更新世常见的亚洲象;5)都含有大量头后骨骼,与以含单个牙齿为主的其它南方洞穴迥然有别。从化石保存状况及属种组成判断,华龙洞堆积时代与和县猿人遗址最为接近,也是中更新世。由于遗址尚未完全暴露,其堆积性质尚不清楚;但从蝙蝠类化石判断,很可能与洞穴堆积有关。     

FGF-21抑制HSC-T6细胞活化的抗肝纤维化作用及其机制的研究

目的:探索成纤维细胞生长因子21(FGF-21)对肝星形细胞T6(HSC-T6)活化的作用及其作用机制。方法:1640+10%胎牛血清的培养基培养HSC-T6细胞,实验分为5组:正常对照组(Control)、模型组(Model 20 m M乙醇处理细胞12 h)、低剂量FGF-21组(LFGF-21,0.5μmol/L)、中剂量FGF-21组(MFGF-21,1.0μmol/L)和高剂量FGF-21组(HFGF-21,2.0μmol/L)。Real-time PCR检测α-平滑肌肌动蛋白(α-SMA)、胶原蛋白Ⅰ(CollagenⅠ)、基质金属蛋白酶-2(MMP2)、基质金属蛋白酶-9(MMP9)和Notch2的m RNA水平,Western blot检测CollagenⅠ、α-SMA、MMP2、MMP9和Notch2的蛋白水平,ELISA检测IL-1β、TNF-α的蛋白水平。结果:模型组α-SMA、CollagenⅠ、MMP2、MMP9、IL-1β、TNF-α、Notch2的水平高于对照组(P0.05),HFGF-21组α-SMA、CollagenⅠ、MMP2、MMP9、IL-1β、TNF-α、Notch2的水平均低于模型组(P0.05)。结论:FGF-21可抑制Notch2的表达,抑制炎症反应,从而抑制HSC的活化,发挥抗肝纤维化作用。     

热带滨海植物红厚壳的抗逆生物学特性

为了解红厚壳(Calophyllum inophyllum)的抗逆特性,对西沙群岛自然生长的红厚壳叶片的形态解剖、生理生态、以及叶片和适生土壤的元素含量进行了研究。结果表明,红厚壳是阳生性植物,其上表皮厚,海绵组织发达且栅栏组织排列紧密,气孔排列松散且密度小(24.40 mm~(-2)),有利于叶片保水抵御干旱。叶片的叶绿素a、b含量低(分别为0.87和0.43 mg g~(-1)),表明红厚壳具适应强光环境的能力。叶片的MDA含量低(13.46 nmol g~(-1)),PRO含量高(127.89μg g~(-1)),SOD活性高(149.42 U g~(-1)),总抗氧化能力高(388.60 U g~(-1)),显示红厚壳能通过提高自身的抗氧化能力抵御膜脂过氧化伤害。红厚壳自然生长的珊瑚岛土壤较为贫瘠、营养元素含量低,但红厚壳植株体内具有较高的营养元素含量,表明红厚壳营养元素利用率高,对于贫瘠土壤具有很好的适应能力。因此,红厚壳具有较高的抗氧化胁迫能力和耐受干旱的能力,适宜生长在热带珊瑚岛等土壤贫瘠的生境,可以作为热带珊瑚岛防风固沙和植被恢复的工具种。     

P—选择素凝集素—EGF功能域的克隆、表达及其单克隆抗体制备

制备特异性抗人P 选择素的凝集素 表皮生长因子 (L EGF)功能域的单克隆抗体。利用特异引物 ,通过RT PCR从外周血血小板中扩增出人P 选择素的L EGF功能域基因 ,将其克隆至pET42b( )载体中 ,测序验证后转染大肠杆菌BL2 1,经诱导表达了C端融合 6×His的蛋白质。融合蛋白质经分离纯化后 ,免疫Balb/c小鼠 ,应用杂交瘤技术 ,通过间接ELISA筛选阳性克隆。获得 3株可稳定分泌抗L EGF功能域单抗的杂交瘤细胞株 (B10、F3和H5 )。其亚型分别为IgG2 、IgG1和IgG3;轻链均为κ型。所获的单抗对LPS刺激活化的人脐静脉内皮细胞均有特异性结合反应 ,并可在体外阻断经凝血酶激活的血小板与中性粒细胞间的粘附。表明所获的单抗可特异性识别结合天然P 选择素 ,具有体外抗活化血小板与中性粒细胞粘附的功能 ,为进一步应用此单抗进行P 选择素结构和功能及抗粘附治疗研究提供了实验基础。     

A review of Cyclidiinae from China (Lepidoptera,Drepanidae)

The subfamily Cyclidiinae from China is reviewed: two genera and seven species are reported from China. One new subspecies, Cyclidiafractifasciataindistinctasubsp. n., is described. Two new synonyms are established: Cyclidiasubstigmaria (Hübner, 1831) (= Cyclidiasubstigmariabrunna Chu & Wang, 1987, syn. n. = Cyclidiatetraspota Chu & Wang, 1987, syn. n.). One misidentification in Chu & Wang (1987) is corrected. Identification keys and diagnoses for all discussed Chinese species are provided. External features and genitalia are depicted. In addition, results of DNA barcoding for five taxa of Cyclidia are briefly discussed.     

北京市两栖爬行动物空间分布格局及影响因素

基于遥感和野外调查数据,研究北京市两栖爬行动物空间分布格局及其影响因素。结果显示,北京记录两栖爬行动物2纲3目10科17属22种,其中,保护物种15种,占物种总数的68.19%。物种分布整体呈现由西北向东南递减的空间特征,西北部山区丰富度和相对多度较大,门头沟和延庆物种丰富度最大(14种),占调查物种总数的66.67%,优势种为中国林蛙、黑斑侧褶蛙、中华蟾蜍和山地麻蜥;门头沟、怀柔、房山分布了全市71.54%的种群数量;200-500 m海拔段物种丰富度最高(18种),主要生境为森林灌丛;物种数在6种以上的网格有11个,包括大滩、怀九河、百花山、拒马河、密云水库等。总体来看,物种种类和数量相较之前呈现减少趋势,而土地用途转换具有重要影响。1980-2018年,建设用地表现出以东西城为核心向外围扩张的趋势,侵占的农田占生态系统总转换面积的42.85%;城六区和平原区的主要物种为黑斑侧褶蛙和中华蟾蜍,少有中国林蛙分布。进一步分析两栖动物1500 m的迁徙距离内,森林灌丛和农田为主要的生境类型,城市扩张侵占了部分农田;同时,污染物的排放引起水体水质下降,特别是北运河水系,造成两栖动物的繁殖率降低和栖息地破坏。目前,北京市各类保护地虽覆盖两栖爬行动物种类的90.91%和数量的60.45%,但在怀柔宝山镇白河上段、密云水库来水的潮河上段辛庄桥、平谷洳河大兴庄镇-峪口镇等地,仍然存在较大的保护空缺。对此,建议开展长期定位观测,构建生物多样性观测网络,并探索建立高强度土地利用下的生物多样性保护机制,从而实现生物资源可持续利用。     

Permutation Testing for Treatment–Covariate Interactions and Subgroup Identification

We consider the problem of using permutation-based methods to test for treatment–covariate interactions from randomized clinical trial data. Testing for interactions is common in the field of personalized medicine, as subgroups with enhanced treatment effects arise when treatment-by-covariate interactions exist. Asymptotic tests can often be performed for simple models, but in many cases, more complex methods are used to identify subgroups, and non-standard test statistics proposed, and asymptotic results may be difficult to obtain. In such cases, it is natural to consider permutation-based tests, which shuffle selected parts of the data in order to remove one or more associations of interest; however, in the case of interactions, it is generally not possible to remove only the associations of interest by simple permutations of the data. We propose a number of alternative permutation-based methods, designed to remove only the associations of interest, but preserving other associations. These methods estimate the interaction term in a model, then create data that “looks like” the original data except that the interaction term has been permuted. The proposed methods are shown to outperform traditional permutation methods in a simulation study. In addition, the proposed methods are illustrated using data from a randomized clinical trial of patients with hypertension.     

双重荧光染色监测听毛细胞游离钙

豚鼠耳蜗分离外毛细胞经fluo-3和fura-red染色后,用激光扫描共聚焦显微镜监测其胞内游离钙的空间分布和动态变化,以fluo-3/fura-red荧光比值大小指示游离钙浓度的高低。外毛细胞胞内游离钙呈不均匀分布,荧光比值分别为细胞质1.71±0.85,质膜1.61±0.75,表皮板1.47±0.65及胞核1.39±0.66,显示细胞质游离钙浓度最高而胞核游离钙浓度最低。静息状态下连续扫描时荧光比值变化小于0.1,而在受到机械刺激后荧光比值增加幅度达0.3—1.2。实验结果表明,fluo-3和fura-red双发射比例法能更准确反映听毛细胞胞内钙的空间分布和动态变化,第二信使钙可能参与了听毛细胞的机械-电换能过程,研究了换能过程中听毛细胞钙信号的时空模式。