黄河三角洲土曲霉Aspergillus terreus OUCMDZ-1925中具抗菌活性的聚酮类天然产物

作者利用化学与生物活性相集成的筛选方法,从采自黄河三角洲地区——东营黄河口的梭鱼Chelon haematocheilus的内脏中分离鉴定了1株耐盐真菌土曲霉Aspergillus terreus OUCMDZ-1925,其发酵产物具有抗枯草芽孢杆菌活性。进一步采用色谱分离、波谱鉴定,从其固体发酵(大米培养基)中分离鉴定了5个化合物,即右旋丁内酯I(1)、丁内酯IV(2)、丁内酯II(3)、丁内酯III(4)和3,5,6-三甲基-2,4-二羟基苯甲酸甲酯(5)。并发现化合物1–3和5对金黄色葡萄球菌(ATCC51650)有强的抑菌活性(最小抑菌浓度均为0.31μg/mL,阳性对照环丙沙星的最小抑菌浓度为0.16μg/mL),化合物1和2对产气杆菌(ATCC13408)以及化合物1和3对枯草芽孢杆菌(ATCC93151)有中等的抑菌活性(最小抑菌浓度分别为6.25μg/mL和12.50μg/mL,阳性对照环丙沙星的最小抑菌浓度分别为1.25μg/mL和5.0μg/mL),化合物1–5对大肠杆菌(ATCC25922)以及化合物4对金黄色葡萄球菌(ATCC51650)有弱的抑制活性,且化合物1的产量高,达2.5g/kg,为其后续研究提供了新的药源。     

10种中药单体对球形孢子丝菌的体外抗真菌作用研究

目的观察10种中药单体对球形孢子丝菌体外抑菌效果。方法参照CLSI的制M38-A2(3rd),采用微量液基稀释法,检测10种中药单体对20株球形孢子丝菌的作用。结果 10种中药单体最小抑菌浓度(MIC)的几何均数范围为53.82μg/mL～1024μg/mL,大蒜素、小檗碱、苦参碱、蛇床子素和丹皮酚的抑菌活性最佳,几何均数分别依次为53.82μg/mL、84.45μg/mL、103.97μg/mL、137.19μg/mL和284.05μg/mL,大蒜素的抗菌作用最强,MIC的范围为16～128μg/mL。最小杀菌浓度(MFC)的范围为64μg/mL～1024μg/mL。大蒜素的MFC值最低,几何均数为415.87μg/mL。结论大蒜素、小檗碱、苦参碱、蛇床子素和丹皮酚对球形孢子丝菌具有一定的抑菌活性,不同中药单体抑菌活性存在差异。     

肽类化合物对H_(37)Ra抑制的优化筛选

通过抑菌试验,确定不同培养基条件下多肽化合物的抑菌效果,并测定其最小抑菌浓度(Minimum inhibitory concentration,MIC)。加入Vc,比较抑菌效果,进一步优化筛选H37Ra抑制剂。先根据ELISA试验结果进行噬菌体肽库筛选,然后利用分子对接软件模拟多肽与ICL蛋白晶体(1F8I)的分子对接,将成功对接的多肽采用Fmoc固相合成法合成,并对其生物活性进行检测。用制备型反相高效液相色谱仪对合成的多肽进行纯化并进行质谱检测。共筛选得到4条多肽且均有抑菌效果,并与剂量相关。结果显示,浓度为800-1 500μg/mL时,各组多肽均抑菌。浓度为500μg/mL时,正常培养基中只有一种肽有抑菌作用,而限制碳源培养基中均不能抑菌。2号肽抑菌效果最好,正常培养基中MIC为200μg/mL,限制碳源中为500μg/mL。阳性对照组,两种培养基抑菌效果一致,利福平MIC为0.8μg/mL,异烟肼MIC为0.5μg/mL。根据MIC结果,在正常培养基中加入Vc,检测到多肽、利福平和异烟肼的抑菌效果呈剂量依赖性升高。     

蛇伤药酒体外抗5种蛇毒的实验研究

目的探讨蛇伤药酒抗五步蛇、竹叶青蛇、眼镜蛇、蝰蛇、蝮蛇蛇毒的效果。方法采用鲎试剂试管凝集反应法。结果蛇伤药酒浓度为1.0 ml/ml时,对5种蛇毒均有破坏产生凝胶反应的作用;浓度为0.5ml/ml时,对五步蛇、竹叶青蛇、眼镜蛇蛇毒有破坏产生凝胶反应的作用;浓度为0.3 ml/ml时,仅对五步蛇毒有破坏产生凝胶反应的作用;浓度降至0.1 ml/ml时,对5种蛇毒均无破坏产生凝胶反应的作用。结论蛇伤药酒有较好的抗蛇毒作用,且对五步蛇毒作用最强。     

聚六亚甲基双胍体外抗真菌作用研究

目的探讨聚六亚甲基双胍(PHMB)对浅部真菌病常见致病菌的杀灭作用。方法参照标准的微量液基稀释法和琼脂稀释法检测PHMB粉剂和溶液对红色毛癣菌、须癣毛癣菌、犬小孢子菌及白念珠菌临床分离株的体外最低抑菌浓度(MIC)和最低杀菌浓度(MFC)。结果 PHMB对红色毛癣菌、须癣毛癣菌、犬小孢子菌和白念珠菌临床分离株的MIC范围分别为1.0～4.0μg/mL、2.0～4.0μg/mL、2.0～4.0μg/mL和0.3～5.0μg/mL;MFC范围分别为2.0～8.0μg/mL、 4.0μg/mL、2.0～4.0μg/mL和5.0～10.0μg/mL。琼脂稀释法结果表明PHMB溶液浓度为1.25%时,红色毛癣菌、犬小孢子菌和须癣毛癣菌无菌落生长;PHMB溶液浓度为0.32%时,白念珠菌无菌落生长。加入透皮剂氮酮后,杀菌效果并无改变。结论 PHMB对浅部真菌病常见的致病真菌皮肤癣菌及白念珠菌具有较好的抑制和杀灭作用。     

波叶大黄多糖对胰腺五种酶的抑制作用

 本文报道波叶大黄多糖(Rheum hotaoense polysaccharide,RHP)对胰腺五种酶的抑制作用。结果表明。(1)RHP对胰蛋白酶、胰脂肪酶、胰淀粉酶、胰弹性蛋白酶和胰激肽释放酶均有很明显的抑制作用。IC_(50)分别为250μg/mL、21μg/mL、18μg/mL,189μg/mL和300μg/mL。(2)动力学研究表明,RHP对胰蛋白酶和胰脂肪酶的抑制均是非竞争性的,Km值分别为1.2×10~(-4)μmol/mL和1.2mg/mL,Ki值分别为355.0μg/mL和63.85μg/mL。(3)牛血清白蛋白(BSA)对RHP抑制胰蛋白晦和胰脂肪酶具有拮抗作用。当BSA浓度达72.0mg/mL时,对胰蛋白酶活性的恢复率为71.54％。当BSA浓度达20.0mg/mL时,对胰脂肪酶活性的恢复率为63.64％。上述结果表明,RHP对胰腺五种酶的抑制作用,可能是大黄治疗急性胰腺炎作用的生化机制之一,预示RHP在临床上将有重要应用前景。     

鸡凝集素的分离纯化与性质研究

鸡菌丝体浸取液依次经硫酸铵分级沉淀,DEAE-Sepharose CL-6B离子交换层析和Sephadex G-100分子筛层析3个主要步骤纯化得到一种凝集素(Termitomyces albu-minosus lectin,简称TAL)。纯化的TAL在聚丙烯酰胺凝胶电泳上显示一条蛋白质着色带。TAL的分子量为89.4kD,亚基分子量为38kD和51kD,提示TAL分子由两个不同亚基组成。TAL具有供血动物种属专一性,使Wistar大鼠红细胞凝集所需TAL最低的浓度为0.49μg/ml。糖抑制试验表明,鸡卵粘蛋白明显抑制TAL的凝血活性。TAL对热不稳定,60℃保温15min活力完全丧失。钙、镁或锰离子对TAL无激活作用。TAL不含不性糖,Glu和Asp含量较高,His和Met含量较低。     

浙江产蝮蛇蛇毒对血小板聚集的影响

浙江产蝮蛇蛇毒的分离参照涂光俦(1979)的方法。浙江产蝮蛇蛇毒经DEAE-Sephadex A-50柱层析分离后得到14个蛋白峰,各峰的蛋白含量见表1。将收集的各峰经适当稀释后取0.2ml进行酶活力测定,除磷脂A酶活力按吴新陆、陈远聪(1981)方法测定外,其他酶活力测定如前文(云南省动物研究所,1976),然后做各峰对血小板聚集功能的影响,参照阮长耿等(1983)的方法,所用诱导剂的浓度为ADP(2μM),AA(100μg/ml)以及PAF(3×10~(-7)M),用这三种诱导剂诱导键康人对血小板产生不可逆性聚集,聚集强度分别为75％,75％和70％。粗毒在最终浓度为250μg/ml时能完全抑制上述三种诱导剂所致的血小板聚集。     

β-防御素130在大肠杆菌中的串联表达、纯化及生物活性分析

为了研究抗菌肽β-防御素130的生物学活性和实现大规模制备,通过改良其分子结构,构建表达载体pET28a-3×β-defensin130,利用大肠杆菌BL21 (DE3)作为宿主细胞诱导表达后为水溶性蛋白。对纯化后抗菌肽进行抑菌实验、稳定性实验、MTT实验和溶血性实验确定其生物活性。最终成功制备出25 kDa的重组蛋白,对金黄色葡萄球菌(ATCC25923)(45μg/mL)和单增李斯特菌(ATCC221633)(80μg/mL)等革兰氏阴性和阳性菌都表现出极强的抗菌活性,且其抗菌活性不受温度、pH值和蛋白酶消化等影响,MTT细胞毒性实验显示其对HEK293细胞无毒性且对兔源红细胞具有极低的溶血性。这将为新型抗菌肽的开发提供理论基础并推动抗生素替代产业快速发展。     

黑皮蛇、山白菜抗五种蛇毒的实验研究

目的研究黑皮蛇、山白菜抗五种蛇毒的药理作用。方法采用鲎试剂凝胶法对黑皮蛇、山白菜抗五种蛇毒的作用进行实验研究。结果黑皮蛇药液浓度在0.4g/ml以上、山白菜药液浓度在0.2g/ml以上,均能抗五种蛇毒与鲎试剂的凝集反应。结论黑皮蛇、山白菜有较强的抗眼镜蛇毒、竹叶青蛇毒、蝰蛇毒、蝮蛇毒和五步蛇毒作用。     

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.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.