邻苯二甲醛衍生化高效液相色谱法分析脑氨基酸

本实验用邻苯二甲醛-β-巯基乙醇衍生化、反相梯度洗脱、荧光检测分析法测定豚鼠脑的氨基酸。60min内可测20种氨基酸。脑组织样本的预处理简单,平均回收率达95％。氨基酸保留时间的变异系数平均为1.1±0.3％(均值±标准差);峰面积的变异系数平均为2.9+0.8％;在10pmol—2nmol范围内,线性关系的相关系数平均为0.987±0.009。本文并对实验所用的色谱条件作了讨论。     

同时测定羟脯氨酸、脯氨酸的氨基酸分析仪短程序

本文制定了单独测定样品中羟脯氨酸和脯氨酸的短程序,用本程序测定羟脯氨酸和脯氨酸的峰保留时间的变异系数分别为０．１６％和０．１９％,峰面积的变异系数分别为１．１３％和１．５３％,比标准程序时间减少５０％,节约茚三酮试剂７０％。     

利用SEC-HPLC法测定重组人透明质酸酶的纯度

目的:建立检测重组人透明质酸酶(rHuPH20)纯度的高效分子排阻色谱法(SEC-HPLC)。方法:利用SEC-HPLC法建立检测rHuPH20纯度的方法,并对方法的专属性、线性、精密度(重复性和中间精密度)、检测限、定量限和耐用性等指标进行评估。结果:空白溶剂在设定的积分范围内无特异峰出现;样品浓度为30~480μg/m L时,数据呈线性关系,决定系数r~2=0.9994;重复性实验峰面积相对标准偏差(RSD)为1.9%;中间精密度实验峰面积RSD为1.1%;检测限为样品浓度10μg/m L时进样体积20μL,即进样量0.2μg;定量限为样品浓度30μg/m L时进样体积20μL,即进样量0.6μg;耐用性实验中,峰保留时间RSD为0.4%,峰面积RSD为1.0%。结论:建立的SEC-HPLC法各项指标符合要求,可用于rHuPH20的纯度检测。     

凝胶柱层析分离虎杖中白藜芦醇的研究

本论文初步探讨了虎杖中白藜芦醇分离纯化的工艺条件,比较了不同溶剂、不同浓度、不同流速洗脱条件下白藜芦醇样品在LH-20凝胶层析柱上的分离效果,以及虎杖的乙醇提取液通过氯仿、乙酸乙酯萃取,凝胶柱层析分离后的成分变化,实验表明,当以甲醇为洗脱液,浓度为60%,流速为0.5 mL/min时,白藜芦醇样品的分离效果最好.采用中压液相色谱检测收集到的白藜芦醇纯度(以白藜芦醇峰面积占总峰面积计算)可达80.34%,回收率达86.16%.     

快速高效液相色谱(FPLC)对猪脾干扰素的分离

本文以猪脾细胞干扰素为材料,应用FPLC结合中性盐沉淀及离子交换层析分离纯化,抗病毒活性回收率达87.8％、FPLC分离的峰一和峰二具有抗病毒活性,用分析型层析柱对二个峰与标准人α、γ干扰素进行洗脱时间比较,前者为α,分子量20,000,后者为γ、分子量为43,000道尔顿。     

应用CE-SDS测定抗CD52人源化单克隆抗体参比品单体纯度及非糖化重链比例

目的:测定抗CD52人源单克隆抗体参比品单体纯度及非糖基化重链比例。方法:采用PA800 plus毛细管电泳系统,非还原十二烷基苯硫酸钠-毛细管电泳(CE-SDS)测定抗CD52人源单克隆抗体单体纯度,以及用还原CE-SDS电泳测定非糖化重链比例。结果:非还原CE-SDS三次测定单体纯度平均值为93.57%,主峰的迁移时间及修正峰面积百分比RSD分别为0.16%和0.19%;还原CE-SDS电泳重链修正峰面积百分比平均值为66.89%,修正峰面积百分比及迁移时间RSD分别为0.09%和0%;轻链修正峰面积百分比平均值为32.30%;轻链修正峰面积及迁移时间RSD分别为0%和0%;非糖基化重链修正峰面积百分比平均值为0.87%,修正峰面积百分比及迁移时间RSD分别为6.66%和0.27%。结论:CE-SDS测定抗CD52人源单抗单体纯度及非糖化重链比例实验结果偏差较小,表明结果准确可靠。     

乙型肝炎病毒感染血清流行病学规律的研究

1984～1987年,在湖南、河南、河北、黑龙江4个试点区,整群抽样采血10 484人,采血率达80％以上。HBsAg、抗-HBs和抗-HBc均用RIA法检测。结果4个点乙型肝炎病毒(HBV)标化感染率为58.2％。HBV感染率随年龄增长而升高,7岁时为51.6％,25岁时达63.7％,接近高峰值。HBsAg标化阳性率为10.1％。HBsAg阳性率显示两个高峰,一个在2～8岁时,即儿童峰。从零岁的3.8％至2周岁时的12.5％,已达高峰。湖南的儿童峰值较其它3个试点区高。故HBsAg阳性率南高北低的现象仍然存在(P<0.01)。另一个峰在20～45岁,即成人峰。 抗-HBs标化阳性率为32.2％。HBsAg:抗-HBs之比值,5岁以内为1:1,10岁以后上升为l:3.3～5.9。抗-HBc标化阳性率为45.5％。此结果表明,调查地区均为HBV高感染区,感染主要发生在儿童期。故新生儿是预防乙型肝炎的重点人群。     

发酵法生产猪苓菌丝体及猪苓多糖的研究

采用经选育的猪苓PU－99菌作为生产菌株,研究了其培养基组成,优化了深层发酵条件。在1吨罐中生产猪苓菌丝体：发酵36h,其菌丝体干重达2．3％,粗多糖含量在31．0％。对得到的猪苓菌丝体进行了有效成分的提取,并测定了猪苓多糖的分子量,分子量为29054,峰面积72．02％。     

分子排阻高效液相色谱法检测促胰岛素分泌肽融合蛋白纯度

目的建立检测促胰岛素分泌肽融合蛋白(Exendin-4-Fc fusion protein,简称E4F4)纯度的分子排阻高效液相色谱法(size exclusion high performance liquid chromatography, SEC-HPLC),并对该方法进行验证。方法使用Waters 515系列高效液相色谱仪,利用TSK G2000SW_(XL)色谱柱检测E4F4的纯度,并从系统适应性、专属性、重复性和中间精密度进行验证,同时使用20、50、100 mmol/L磷酸盐缓冲液的流动相对样品进行了6次纯度检测。结果空白溶剂在目标峰积分范围内无干扰峰;专属性验证表明样品与阴性对照分离度良好;6次重复进样目标峰面积相对标准偏差(relative standard deviation,RSD)为0.49%,保留时间RSD为0.11%;中间精密度分析目标峰面积RSD为0.47%,保留时间RSD为0.48%;使用不同盐浓度(20～100 mmol/L PBS, pH 6.8)的流动相对样品进行6次纯度检测后,各样品纯度均大于99.0%,目标峰面积RSD为0.53%,保留时间RSD为0.76%。结论经验证,建立的SEC-HPLC法各项指标均符合要求,可用于E4F4的纯度检测。     

反相高效液相色谱法测定发酵液中L-精氨酸含量

建立了一种用反相高效液相色谱测定发酵液中精氨酸含量的方法。以丙氨酸为内标物,2,4-二硝基氟苯为柱前衍生剂,用C18色谱柱在柱温30℃下,于362nm波长处检测,精氨酸质量浓度在0．Sg／L～1g／L时,其峰面积与内标物峰面积的比值和精氨酸的质量浓度的线形相关系数大于0．9998,加标回收率在104％左右。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.