沙门菌CWDMs乳酸脱氢酶同功酶的观察

采用聚丙烯酰胺凝胶电泳法检测伤寒杆菌和甲型副伤寒杆菌的ＣＷＤＭｓ及其宁代细菌型和伤寒杆菌粗糙型的乳酸脱氢酶（ＬＤＨ）同功酶,以了解沙门菌ＣＷＤＭｓ生物氧化的特点和机制,探讨ＣＷＤＭｓ变异的性质。结果表明,伤寒杆菌和甲型副伤寒杆菌的细菌型及伤寒杆粗糙型在聚丙烯酰胺凝胶电泳后显示出相同的４种具有不同泳动速率的ＬＤＨ同功酶,但ＣＷＤＭｓ仅显示２种ＬＤＨ。ＣＷＤＭｓ的２种ＬＤＨ同功酶与其亲代细菌型及伤寒杆     

伤寒杆菌稳定L型粗糙型返祖菌的蛋白图谱和抗原研究

甲型副伤寒杆菌温和噬菌体转导伤寒杆菌稳定Ｌ型返祖形成的两株粗糙型伤寒杆菌,在ＳＤＳ－ＰＡＧＥ电泳中缺失多条高分子量蛋白带。抗原分析表明,两株粗糙型返祖菌具有同其亲代伤寒杆菌一致的Ｈ抗原,但缺乏Ｏ抗原以及伤寒杆茵和甲型副伤寒杆茵共同的某些表面抗原。     

金樱子茎提取物体外抑菌活性研究

采用纸片扩散法和试管稀释法,研究金樱子茎不同溶剂粗提取物对临床常见病原细菌的抑菌活性。结果表明,金樱子茎水提取物对绿脓杆菌、痢疾杆菌、大肠杆菌、变形杆菌无抑菌活性;对伤寒杆菌的最低抑菌浓度（MIC）为20 mg（生药）/mL;对金黄色葡萄球菌的MIC为10 mg（生药）/mL。金樱子茎75%乙醇提取物对绿脓杆菌、伤寒杆菌、痢疾杆菌、大肠杆菌、变形杆菌无抑菌活性;对金黄色葡萄球菌MIC为10 mg（生药）/mL。金樱子茎乙酸乙酯、氯仿、石油醚提取物对绿脓杆菌、伤寒杆菌、痢疾杆菌、大肠杆菌、金黄色葡萄球菌、变形杆菌无抑菌活性。     

L型细菌普通细菌对热抵抗力的比较

目前,热力常用于消毒与灭菌,其对普通细菌具有明显的致死作用,早已是众所周知,但其对Ｌ型细菌的杀灭作用,国内外研究较少。我们以金黄色葡萄球菌、大肠杆菌、伤寒杆菌、绿脓杆菌、宋内氏痢疾杆菌、枯草杆菌、表皮葡萄球菌等及其Ｌ型菌在实验室内进行了初步观察,现将...     

细菌L型的厌氧诱导和培养

厌氧条件下以羧卡青霉素诱导金黄色葡萄球菌、大肠杆菌和蜡样芽胞杆菌形成Ｌ型,观察细菌Ｌ型在厌氧条件下的形成、形态、生长及时渗透压的敏感性等特性。结果表明：蜡样芽胞杆菌在厌氧条件下不能形成Ｌ型或其Ｌ型在厌氧条件下亦不能返祖。金黄色葡萄球菌和大肠杆菌在厌氧条件下虽能诱生Ｌ型,但形成丝状体的构成Ｌ型菌落难以传代培养,厌氧培养未见Ｌ型圆球体和典型Ｌ型油煎蛋样菌落。金黄色葡萄球菌Ｌ型在含１％～１０％ＮａＣｌ的Ｌ型培养基上可生长形成Ｌ型菌落或非菌落形式存在的Ｌ型巨形体;大肠杆菌和蜡样芽胞杆菌的Ｌ型在含２％～６％ＮａＣｌ的Ｌ型培养基上可生长形成Ｌ型菌落或非菌落形式存在的Ｌ型巨形体。涂片染色或返祖试验证实细菌Ｌ型在含０．５％ＮａＣｌ的Ｌ型培养基或常规细菌学培养基上亦可生存。非菌落性Ｌ型巨形体和丝形体是细菌Ｌ型在琼脂培养基上广泛的存在形式。     

沙门菌CWDMs苹果酸脱氢酶的检测

目的：了解沙门菌细菌壁缺陷突变株（CWDMs）的生物氧化及遗传特点和探讨细菌壁缺陷变异的性质与机制。方法：采用PAGE电泳法和分光光度法检测伤寒沙门菌和甲型副伤寒沙门菌及其CWDMs和伤寒沙门菌粗糙型和苹果酸脱氢酶（MDH）同工酶的活性与类型。结果：伤寒沙门菌和甲型副伤寒沙门菌的细菌型和伤寒沙门菌粗糙型经PAGE电泳可见一条MDH同工酶带,CWDMs电泳后可见两条MDH同Ⅰ酶带,在CWDMs的MDH中有一条泳动速率与细菌型及粗糙型的相同,另一条则较快。分光光度法检测证实。细菌型与粗糙型的MDH活性相似,CWDMs的MDH活性则明显较低。结论：CWDMs保留了与亲代细菌型一致的MDH和形成了一种新的MDH,并且其MDH的活性已显著降低,此特性可能与CWDMs生物氧化特性的改变有关。     

三种SPF小鼠喉气管粘膜细菌丛初步分析

目的：了解ＳＰＦ级免疫功能正常小鼠及免疫功能缺陷小鼠喉气管粘膜细菌分布情况,探讨菌丛分布与免疫功能的关系。方法：按占群体１５％的比例随机抽取小鼠,无菌手段采集样品作需氧和厌氧培养分离单纯菌落,作出鉴定。结果：免疫功能正常的小鼠有１种：ＢＡＬＢ／ｃ小鼠,检出细菌有赛氏葡萄球菌、模仿葡萄球菌、大肠杆菌;免疫功能缺陷的小鼠有ＢＡＬＢ／ｃ裸小鼠和Ｓｃｉｄ小鼠,检出细菌有：变形杆菌、表皮葡萄球菌、腐生葡萄球菌、赛氏葡萄球菌、大肠杆菌、胶团拟杆菌、口颊拟杆菌、衣氏放线菌、绿脓杆菌、大消化链球菌和有待进一步鉴定的革兰氏阳性杆菌。结论：提示免疫功能正常与缺陷的ＳＰＦ小鼠上呼吸道存在的菌丛可以与小鼠共生,并无引起明显病理改变     

细菌在不同渗透压培养基上的青霉素敏感性

在含ＮａＣｌ０％～１０％的Ｌ型培养基上观察金黄色葡萄球菌、蜡样芽胞杆菌及大肠杆菌对青霉素Ｇ的敏感性和金黄色葡萄球菌Ｌ型对糖的发酵作用和卵磷脂酶活性。结果表明金黄色葡萄球菌、蜡样芽胞杆菌和大肠杆菌在低于、等于或高于细菌细胞内渗透压的培养基上对青霉素的敏感性相似。少数存活的细菌Ｌ型不发酵糖和丧失卵磷脂酶活性,但返祖菌可恢复糖发酵和卵磷脂酶活性。提示细菌细胞内、外渗透压差不是唯一的导致细胞壁缺陷细菌死亡的原因。而胞质周围间隙的破坏,导致其内含酶类的丧失,可能是细胞壁缺陷细菌死亡的重要机制。     

L型细菌、普通细菌对紫外线照射的实验比较

目前,紫外线消毒已得到广泛应用,其对细菌的杀灭作用早已是众所周知,但对Ｌ型细菌杀灭作用的报导甚少。我们以金黄色葡萄球菌、大肠杆菌、伤寒杆菌、绿脓杆菌、宋内氏痢疾杆菌、枯草杆菌、表皮葡萄球菌等,在实验室内进行了初步观察,现将结果报告如下：１材料与方法１...     

细菌L型对化学因素敏感性研究

本文研究了伤寒沙门氏菌、葡萄球菌及白喉棒状杆菌L型对化学消毒剂、细菌生长抑制剂、酸和碱的敏感性,并与其亲代细菌型作了比较。结果表明:细菌L型对表面活性剂、酚剂、重金属盐、脱水剂、卤素及氧化剂的敏感性明显(P<0.05)或不明显(P>0.05)增加,伤寒沙门氏菌L型对龙胆紫、玫瑰色酸、胆盐及酸的敏感性增高,葡萄球菌及白喉棒状杆菌L型对龙胆紫、玫瑰色酸、胆盐及酸的敏感性降低,伤寒沙门氏菌及白喉棒状杆菌L型对碱敏感性降低。     

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.