分离自蔬菜地的腐霉一新种及其rDNAITS序列分析(英文)

从广西南宁收集的蔬菜地土壤样本中,分离得到一个新的腐霉种,命名为广西腐霉Pythium guangxiense。不同于其近似种,广西腐霉的孢子囊球形或亚球形;藏卵器球形、亚球形、椭圆形或囊形;雄器同丝生或异丝生,柄常分枝且缠绕藏卵器。对构成广西腐霉rDNAITS区段的772个碱基进行扩增和测序。在根据ITS序列建立的分子系统发育树中,广西腐霉与禾生腐霉Pythium graminicola、周雄腐霉P.periilum和肿囊腐霉P.inflatum等产生瓣状孢子囊的腐霉种关系密切。对广西腐霉进行了分类描述和其与近似种的比较。     

动力髁螺钉与微创内固定系统治疗股骨远端骨折疗效的比较

目的:比较动力髁螺钉(DCS)与微创内固定系统(LISS)治疗股骨远端骨折的疗效.方法:对DCS组(38例)和LISS组(23例)患者临床资料和影像结果进行回顾性对比分析.结果:两组患者术后无感染,切口均一期愈合.本资料总的骨折愈合率为93.4%(57/61),DCS组与LISS组愈合率分别为94.7%(36/38)和91.3%(21/23)(p=0.643),平均愈合时间分别为20.3周(16-29)和19.5周(16-26)(p=0.856).膝关节功能按Merchant评分标准,DCS组与LISS组优良率分别为94.7%(36/38)和95.7%(22/23)(p=0.772).早期螺钉松动(术后12周内)只发生在DCS组(7.9%,p=0.236,OR=1.753[95%CI:1.302-2.415]).结论:DCS和LISS治疗股骨远端骨折均取得良好的疗效,LISS装置早期松动的风险似乎低于DCS.     

食管癌合并Ⅱ型糖尿病的围手术期处理

目的:探讨食管癌合并糖尿病的围手术期处理方法和外科治疗效果,为该病的临床治疗提供指导.方法:对49例食管癌合并糖尿病患者,采用控制血糖结合手术切除肿瘤治疗;选取49例同期非糖尿病食管癌患者做参比.手术前后采取个性化心理护理,分析比较两组的治疗效果.结果:所有患者手术切除率为100%,无围手术期死亡.食管癌合并糖尿病组术后并发症7例,包括吻合口瘘2例,肺部感染2例,单纯脓胸1例,切口感染2例,均经治疗后痊愈;同期非糖尿病食管癌组手术并发症2例:肺部感染1例,切口感染1例.采用个性化心理护理前后,两组患者的消极、焦虑、恐惧等不良心理得到明显的缓解,对手术效果及围手术期处理效果总满意度达95%.结论:糖尿病引起代谢紊乱易发生愈合不良及各种感染,使术后并发症发生率显著高于同期非糖尿病患者.因此在合并糖尿病的食管癌外科治疗中,围手术期处理至关重要.     

靶向Smad4基因shRNA质粒表达载体的构建及筛选

目的:构建编码Smad4mRNA的shRNA真核表达载体,并筛选出基因沉默效果最明显的shRNA质粒表达载体.方法:根据GenBank提供的人Smad4基因的mRNA序列构建2个shRNA质粒表达栽体和1个阴性对照质粒表达载体,并通过基因测序进行鉴定.经鉴定后转染体外培养人成纤维细胞,western-blot检测Smad4蛋白水平抑制表达效果.结果:构建质粒表达载体测序结果显示,插入片段测序结果与合成的shRNA序列一致;靶向Smad4基因shRNA质粒表达栽体对所转染的人成纤维细胞中Smad4蛋白水平表达均有抑制作用,其中shRNA1最为明显.结论:成功构建了靶向Smad4基因shRNA质粒表达栽体,其中抑制Smad4基因表达效果最为明显的是shRNA1,为进一步研究Srnad4基因的RNA干扰奠定了基础.     

Molecular Basis of Neurovirulence of Flury Rabies Virus Vaccine Strains: Importance of the Polymerase and the Glycoprotein R333Q Mutation

The molecular mechanisms associated with rabies virus (RV) virulence are not fully understood. In this study, the RV Flury low-egg-passage (LEP) and high-egg-passage (HEP) strains were used as models to explore the attenuation mechanism of RV. The results of our studies confirmed that the R333Q mutation in the glycoprotein (G_R333Q) is crucial for the attenuation of Flury RV in mice. The R333Q mutation is stably maintained in the HEP genome background but not in the LEP genome background during replication in mouse brain tissue or cell culture. Further investigation using chimeric viruses revealed that the polymerase L gene determines the genetic stability of the G_R333Q mutation during replication. Moreover, a recombinant RV containing the LEP G protein with the R333Q mutation and the HEP L gene showed significant attenuation, genetic stability, enhancement of apoptosis, and immunogenicity. These results indicate that attenuation of the RV Flury strain results from the coevolution of G and L elements and provide important information for the generation of safer and more effective modified live rabies vaccine.Rabies virus (RV) belongs to the genus Lyssavirus of the family Rhabdoviridae and causes a fatal neurological disease in humans and animals (6). The RV genome is a nonsegmented negative-strand (NNS) RNA encoding five structural proteins: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G), and large polymerase (L). Among these, the G protein is a major contributor to RV pathogenicity (7, 31, 33). The G protein facilitates fast virus entry and transsynaptic spread and regulates the rate of virus replication, together with other viral elements (8, 30, 39). The G protein of nonpathogenic RV strains can trigger apoptosis, while the RV G of pathogenic strains induces less or no apoptosis (35, 59). The amino acid residue at position 333 of the G protein (G333) of some fixed strains has been shown to be an important determinant of virulence in adult mice (5). Strains that have arginine or lysine at position G333 kill adult mice, whereas mutants with other amino acids at this site cause a nonlethal infection (1, 5, 25, 36, 49, 53). However, the pathogenicity of RV strains is not solely determined by substitutions at the G333 position. Other substitutions in the G protein, such as N194K, have also been shown to affect viral pathogenicity in mice (10, 21, 50). In addition, other viral elements, such as the N, P, M, and L genes, the trailer sequence in the noncoding region, and the pseudogene, were also reported to modulate RV pathogenicity (12, 46, 57, 58). How these viral elements regulate the pathogenicity of RV remains to be fully explored, and further investigation is needed to understand the molecular basis of RV pathogenicity.Attenuated Flury RV low-egg-passage (LEP) and high-egg-passage (HEP) strains were established through serial passage in chicken brain, chicken embryos, and culture cells using a Flury RV isolated from a girl who died of rabies (23, 24). LEP has Arg at position G333 and kills adult mice after intracerebral (i.c.) inoculation, while HEP has Gln at G333 and causes only mild signs in adult mice. It has been demonstrated that HEP could regain lethality in adult mice by a single amino acid change at G333 from Gln to Arg (49), which indicated that Arg at position G333 is a key determinant of pathogenicity of Flury RV in adult mice. However, whether the Arg at G333 is indispensable for the lethal phenotype of LEP has not been demonstrated.In the current study, LEP and HEP Flury RV strains were used as models to investigate the mechanism of attenuation. We found that both G and L contribute to the attenuation of Flury RV. Substitution of Arg with Gln at G333 (G_R333Q) eliminated LEP neuroinvasiveness but not the virus'' lethal phenotype in adult mice after i.c. inoculation. The G_R333Q mutation could be kept stable only in the genome background of HEP but not in that of LEP during replication. The L gene contributes to the attenuation and enhanced immunogenicity of Flury RV by promoting the stabilization of the G_R333Q mutation during virus replication in brain tissues or cells.     

SARS冠状病毒的起源研究进展

SARS冠状病毒（SARS-CoV）是一种新现病毒,可感染多种动物,果子狸是人类sARs-CoV重要的动物宿主之一,是已知较理想的实验动物模型。遗传因素在SARS-CoV的出现过程中起重要作用,它很可能是哺乳动物和鸟类冠状病毒之间重组产生的新物种,但发生基因重组不是SARS在人群中暴发的原因。     

漆酶在磁性壳聚糖微球上的固定及其酶学性质研究

以磁性壳聚糖微球为载体,戊二醛为交联剂,共价结合制备固定化漆酶。探讨了漆酶固定化的影响因素,并对固定化漆酶的性质进行了研究。确定漆酶固定化适宜条件为：50 mg磁性壳聚糖微球,加入10mL 0.8mg/mL 漆酶磷酸盐缓冲液（0.1mol/L,pH 7.0）,在4℃固定2h。固定化酶最适pH为3.0, 最适温度分别为10℃和55℃,均比游离酶降低5℃。在pH 3.0,温度37℃时,固定化酶对ABTS的表观米氏常数为171.1μmol/L。与游离酶相比,该固定化漆酶热稳定性明显提高,并具有良好的操作和存储稳定性。     

Jurkat细胞凋亡的实时电旋转芯片检测

细胞凋亡是当今生物学中最受关注的领域之一。当前细胞凋亡的检测方法一般都需要对细胞进行化学处理,不能实现对凋亡的实时监测。为了研究细胞凋亡过程中细胞膜电容的变化规律,采用电旋转芯片测量凋亡细胞的电旋转频谱,进而推算出细胞的膜电容。结果显示,随着时间的增加,凋亡细胞的膜电容逐渐减小。在此基础上提出一种用电旋转芯片测定细胞膜电容的方法来检测细胞凋亡。该方法无需对细胞进行化学处理,可以实现对细胞凋亡的实时监测,为研究细胞凋亡提供了一种新的工具。     

拉祜族食疗花卉的研究

对拉祜族的食疗花卉进行了探讨.结果表明,拉祜族有着丰富的食疗花卉知识,其形成有着特殊的医药和文化背景以及朴素的早期传统民族医药特征;拉祜族民间普遍存在的花卉食疗现象,是对其生存空间内现有食物的自然选择结果,是传统知识的积累使然,是在与各民族相互学习交流中得到启迪而加以利用的结果,具有原住民文化特征,是民族文化多样性的重要组成部分.拉祜族食疗花卉约有53种,分别隶属于28个科,较有特色的花卉包括杜鹃花(Rhododendron spp.)、姜花(Alpinia spp.、 Amomum spp.、 Zingiber spp.)、山茶花(Camellia spp.)、蜜蒙花(Buddleja officinalis Maxim.)等.此外还探讨了拉祜族传统文化与当地自然资源及其生物多样性的关系,认为今天拉祜族聚居地还保留有丰富的森林植被和物种,与他们对自然资源的管理与合理使用有着密切的关系.     

Supplemental Cytogeographical Studies on the Scilla sinensis （Louriro） Merrill Complex in China

Seven hundred and fourteen individuals of the Scilla sinensis (Louriro) Merrill complex were sampled from 21 populations at 19 localities in 10 provinces and two cities of China and investigated cytologically in order to test its cytotype composition and cytogeographical variation still further. Five cytotypes were found (i.e. AA (2n = 16), BB (2n = 18), AABB (2n = 34), AAA (2n = 24), and AABB 9 (2n =43)). Until now, nine of the 12 cytotypes have been identified on the continent, which indicates that it is an important place for the cytotypic differentiation of the complex. The cytotype AABB 9 is a new record on the continent. AAA was recorded for the second time in this complex. The majority of populations are composed of only one cytotype (AA, BB, or AABB), whereas another four populations consist of more than two cytotypes involving AA, BB, AAA, AABB, and AABB 9. The distribution of BB covers the entire region south to Huai River, whereas AA populations are distributed in Taiwan, Fujian, Hong Kong, and Guangdong and are isolated from its major distribution. The appearance of AABB 9 is possibly evidence for the degeneration of the subglobular bulb type of AABB and the fact that AAA and AAAA exist in the interior border regions of the range of this complex probably suggests that drought is a major factor promoting plant polyploidization. In addition, the mean numbers of B chromosomes per individual, the percentage of individuals with the B chromosome in each population, and the correlation coefficients between the latter and their latitude/longitude were calculated. Generally speaking, the B chromosome number is higher in BB populations compared with AA populations and there is a prominent tendency that the B chromosome content in either AA or BB populations correlates with the latitude and longitude of the populations.