流行我国云南的猪人住肉孢子虫(Sarcocystis suihominis)的人——猪间循环感染研究

本文对流行于我国云南的猪人住肉孢子虫(Sarcoystis suihominis)作了人——猪间的循环感染研究。表明它与流行于欧洲的猪人住肉孢子虫在寄主特异性、排卵囊前期、缓殖子大小、包囊在中间寄主体内的分布和包囊壁的超徽结构等方面有一定差异。究竟两者是否同属一个种,有待进一步研究。     

水牛和黄牛肉孢子虫包囊超微结构研究

左仰贤(1988)曾报道一种寄生于水牛的肉孢子虫未定种(Sarcocystis sp.)包囊,其光学形态和梭形肉孢子虫(S.fusiformis)、莱氏肉孢子虫(S.levinei)、枯氏肉孢子虫(S.cruzi)、毛肉孢子虫(S.hirsuta)的包囊均不同。本文用扫描和透射电镜对这五种肉孢子虫包囊的超微结构进行观察。 材料和方法 将包囊分别用0.85％生理盐水清洗,然后用2.5％戊二醛固定,(1)经脱水、干燥、喷金,用 Jsm 3.5 型扫描电镜观察;(2)用 0.1mol/L、pH7.2 磷酸盐缓冲液洗两次,1％ 锇酸固定,经脱     

黄牛肉孢子虫对犬和猫的感染试验

将感染肉孢子虫的牛肉喂给4条犬和4只猫,分别于9—11天和8—9天从粪中检出孢子囊,其感染分别持续28—37天和28—34天。对照犬猫粪中一直未查出孢子囊。感染犬猫粪中的孢子囊均为椭圆形,无色,内有4个子孢子和不规则颗粒性残体,其大小分别为15.44×10.09μm和12.12×7.68μm。用感染犬粪中的新鲜孢子囊接种另2条健犬,粪检未见孢子囊。对感染清除后的2条犬再次接种包囊,发生了与初次接种类似的感染过程。结果表明,感染东北黄牛的肉孢子虫至少2种,牛犬肉孢子虫(Sarcocystis bovicanis)和牛猫肉孢子虫(Sarcocystis bovifelis)。     

试验感染水牛体内枯氏住肉孢子虫内生发育的超微结构

通过人工感染试验在电镜下对一种住肉孢子虫在水牛体内的发育进行了研究。结果揭示在血管内皮细胞中的裂殖生殖和在肌细胞内的包囊发育过程与枯氏住肉孢子虫的一致,裂殖体、裂殖子、包囊壁和囊内母细胞、缓殖子的超微结构亦与枯氏住肉孢子虫的相同。首次通过试验感染的发育史研究证明,流行于我国湖南水牛的一种小包囊属于枯氏住肉孢子虫,水牛是黄牛枯氏住肉孢子虫的新宿主。     

丛枝菌根真菌的两个中国新记录种

疣壁球囊霉图1-3 Glomus verruculosum J. Blaszkowski ＆ M. Tadych, Mycologia, 89: 809, 1997. Fig. 1-3 孢子果不详.孢子单生于土壤中,黄色至橙色.球形至近球形,大小为(150-)189(-265)μm, 有时呈卵圆形,大小为145-170×170-220 μm.孢子壁一组两层,外壁层(outer wall, OW)为透明壁,厚(0.8-)1.3(-1.7)μm.内壁层(inner wall, IW)为层状壁,黄色至橙色,厚(5.1-)9.8(-12.5)μm,饰有均匀分布的疣突,疣突高为0.8-1.7 μm.连孢菌丝单根,直形或弯曲,管状至近圆柱形,连点处宽(15-)21.3(27.5)μm.连丝壁与孢壁内壁层同色,黄色至橙色,连丝基部壁厚(4.8-)5.6(-6.9)μm,孢子内壁层与之延续,外壁层可沿连丝下延长达至25 μm.在Melzer's试剂中,孢子及连孢菌丝的各壁层颜色反应均不明显.连点由内壁层部分层状壁阻塞,偶尔发现也有不封闭的情况.     

鹿内阿米巴新种的研究

在一只毛冠鹿(Elaphoduscephalophus)粪便内,检获一种小型单核包囊型阿米巴。经铁苏木素染色,显微测微观察,其滋养体大小为6.00—11.00μm,平均为8.20±1.48μm;包囊大小为5.50—8.00μm,平均为6.95±0.06μm;属内阿米巴科Endamoebidae内阿米巴属Entamoeba的一新种,命名为鹿内阿米巴(Entamoebacervumsp.nov.)。     

羚牛住肉孢子虫在中国首次发现

以羚牛(Budorcas taxicolor)作为住肉孢子虫Sarcocystis的中间宿主,至今国内外尚无报道。1989年4月,在成都市动物园自然死亡的一头羚牛的食道和舌肌上发现有大量形似纺锤形肉孢子虫Sarcocystis fusiformis(同种异名有S.blanchardi,S.siamensis,S.bubali,Balbiania fusiformis)寄生。现将其外观形态和组织切片(H.E染色)的显微观察记述如下:寄生于羚牛的住肉孢子虫(包囊)位于肌原纤维间,其长轴方向与肌纤维方向一致。外观为乳白色的纺锤形或长椭圆形,大小为4.7×2.25(3.0—6.5×1.5—3.0)mm。囊壁由两层构成,外壁厚呈海绵样,H·E染色为粉…     

湖北恒河猴体内恰氏内阿米巴的形态学观察

调查武汉动物园的恒河猴,发现自然感染恰氏内阿米巴(EntamoebachattoniSwellen-grebel,1914),采用生理盐水直接涂片法、卢戈氏碘液染色及铁苏木素染色封片,对滋养体和胞囊进行观察,并对滋养体、体核、包囊、囊核作了显微测量。恰氏内阿米巴滋养体大小为11—17μm,平均13.70±0.37μm(X±Sx),核为2.89±0.02μm,包囊为10.30±0.09μm和囊核2.83±0.03μm。双核型包囊少于1%,含有包涵体的包囊占50%,恒河猴自然感染恰氏内阿米巴为国内首次发现。     

中国丛枝菌根真菌一新记录种

疣壁盾巨孢囊霉图1-5 Scutellospora verrucosa (Koske & Walker) Walker & Sanders, Mycologia, 77(5): 702, 1985. Fig.1-5 孢子单生于土壤中,球形至近球形,桔黄至桔棕色,212-325×212-325μm.孢子壁三层(W1-W3).W1易碎,透明至桔黄色,0.7-1.8μm厚,饰有密集、矮小的圆形疣突,疣突基部0.5-1.0×0.5-1.0μm,高0.5-1.2μm.W2紧贴W1,层状壁,桔黄至桔棕色,半透明,6.2-7.5μm厚,在Melzer's试剂中呈红棕色反应.W3为萌发壁(gerninal walls,GW),包括两层透明薄壁(L1和L2),L1厚度不超过0.5μm,L2 0.6-1.2μm厚,两层壁常紧贴在一起,均无Melzer's试剂反应.在成熟孢子中,由W3折叠形成一个卵圆形、结构复杂的发芽盾室(germination shield),80-90×130-150μm,芽管由发芽盾室上萌发.球茎状细胞(suspensor-like cell)黄棕色,比孢子颜色稍深,40-60×35-60μm,壁厚2-3μm,近孢子处加厚至7μm左右.连孢菌丝壁薄,有隔,直径3-4μm.土生辅助细胞(auxiliary cell)未见.     

枯氏住肉孢子虫在黄牛与水牛之间的交叉感染研究

试验选用7日龄黑白花奶牛4头和4—5月龄水牛4头。用从犬获得的水牛源孢子囊人工感染2头奶牛和2头水牛,用黄牛源孢子囊人工感染1头水牛,2头奶牛和1头水牛不感染留作对照。在试验期间,1头感染奶牛和1头对照奶牛因急性肠炎死亡,2头感染水牛因急性住肉孢子虫病死亡,从感染奶牛和感染水牛的内脏器官查出裂殖体。1头感染奶牛、1头感染水牛和2头对照牛在第98—115天剖检,从感染水牛源孢子囊的1头奶牛和感染黄牛源孢子囊的1头水牛肌肉查出大量包囊,1头对照奶牛和1头对照水牛均未查出任何虫体。对奶牛和水牛肌肉包囊超薄切片的电镜观察显示,所有包囊的超微结构均与文献对枯氏住肉孢子虫的报道一致。这一试验性研究证明:水牛与黄牛同是枯氏住肉孢于虫的中间宿主。     

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.