方形黄鼠蚤松江亚种幼虫形态及与同属蚤幼虫的比较

蚤类的幼虫形态,我国迄今已报告15种,其中蚤科Pulicidae 3种,多毛蚤科Hystrichopsyliidae 4种,细蚤科Leptopsyllidae 2种,蝠蚤科Ischnopsyllidae 1种,角叶蚤科Oeratophyllidae 5种。而角叶蚤科的黄鼠蚤属Citellophilus目前已报告2种,即方形黄鼠蚤指名亚种C.t.tesquorum(1961)和三鬃黄鼠蚤巴湖亚种C.trispinus balkhaschensis(叶瑞玉等,1982)。我们在探索方形黄鼠蚤松江亚种C.tesquorum sungaris的生物学特征中,对它的幼虫形态进行了研究,并与同属2个亚种的幼虫形态相比较。     

阿拉善黄鼠三种寄生蚤幼虫形态

我国蚤类幼虫形态的描述至1982年先后已发表15种,包括5个科,7个亚科的12个属。本文再报道来自青海地区阿拉善黄鼠(Citellus alaschanicus B?chner)巢内的方形黄鼠蚤蒙古亚种(Citellophilus tesquorum mongolicus Jordan&Rothschild,1911),似升额蚤长指亚种(Frontopsylla elatoides longa Mikulin,1958)和阿巴盖新蚤(Neopsylla abagaitui Ioff,1946)等三种寄生蚤幼虫的形态。     

二齿新蚤和方形黄鼠蚤松江亚种侵袭与离开宿主习性的实验研究

本文对二齿新蚤和方形黄鼠蚤松江亚种侵袭与离开宿主的习性进行了实验研究,结果：(1)蚤攻击宿主距离平均在2cm以内,最大攻击距离不超过10cm。在有效侵袭范围内,蚤与宿主距离近时较距离远时吸血蚤数增多。(2)蚤对宿主的侵袭程度雌蚤大于雄蚤,繁殖蚤大于新羽化蚤,二齿新蚤大于方形黄鼠蚤松江亚种,对小白鼠大于对达乌尔黄鼠。(3)宿主死后一定时间内,仍有部份蚤侵袭其尸体。 死亡时间越长侵袭蚤数越少,呈logY=a-blogX型曲线。(4)蚤离开宿主时间呈偏态分布,温度越高偏态分布越明显。蚤离开死鼠和离开活鼠所需时间很接近。 二齿新蚤和方形黄鼠蚤松江亚种离开宿主时间几乎相同。二种蚤离开宿主平均时间与环境温度呈负相关,且呈曲线关系。     

似升额蚤一新亚种(蚤目:细蚤科)

据文献记载,似升额蚤Frontopsylla(Frontopsylla)elatoides有两亚种,即似升额蚤指名亚种Frontopsylla(Frontopsylla)elatoides elatoides Wagner,1929和似升额蚤长指亚种F.(F.)elatoides longa Mikulin,1958。前者分布在苏联,蒙古及新疆、内蒙古,主要宿主为长尾黄鼠Citellus undulatus;后者仅分布于苏联的哈萨克,主要宿主为平颅高山(鼠平)Alticola strelzovi,赤颊黄鼠Citellus erythrogenys和灰仓鼠Cricetullus migratjorius。青海和甘肃两省的似升额蚤标本与上述两亚种均有区别。鉴于本新亚种的形态特征介于已知的两亚种之间,故命名为:     

二齿新蚤和方形黄鼠蚤松江亚种活动习性

1991～1992年在实验室内观察了二齿新蚤和方形黄鼠蚤松江亚种在无宿主条件下的活动习性。二种蚤在黑暗处纸片下的蚤数多于纸片上;在光亮处纸片上下蚤数变化无常。二齿新蚤在20和30±1℃下,黑半面蚤数均多于白半面。方形黄鼠蚤松江亚种在20±1℃下,多数组黑半面蚤数多于白半面;在30±1℃下,多数组白半面蚤数多于黑半面。蚤在直立纸片上。绝大多数向上爬。培养基质凹坑内蚤数多于凹坑外。     

达乌尔黄鼠洞内蚤的空间分布

黄鼠洞内共发现9种及亚种蚤,其中以黄鼠蚤松江和二齿新蚤数量最多,其余各种蚤均为散见。前两种蚤在洞内各区段染蚤指数不等,但基本都有分布,巢内数量占据首位。松江黄鼠蚤的消长曲线呈双峰型,二齿新蚤的曲线比较平稳。两种蚤的空间分布特点是巢内多于洞干,洞干多于洞口。根据巢蚤数量二齿新蚤归属“巢型蚤”是无疑的,但松江黄鼠蚤是否隶属“皮型蚤”应进一步研究和讨论。在数量预测中采用O-MXC的公式较为适宜。根据蚤的空间分布图式,消灭跳蚤时应密切注意巢内的跳蚤。可采用滴滴涕或其他灭蚤有效的有机磷、氨基甲酸酯等粉剂,亦可采用缓释杀虫剂等进行毒杀。     

脂肪酸气相色谱图鉴别方形黄鼠蚤各亚种的初步研究

方形黄鼠蚤４个亚种在脂肪酸组分和百分含量上具有明显不同,其中雌虫在１８个组分上有区别雄虫在１４个组分上有区别。此外,雌虫在Ｃ１６：１和Ｃ２０：０的含量上,雄虫在Ｃ１６：１的含量上,４个亚种之间均具有显著性差异。在Ｃ１２－Ｃ２２区间内有９个含量较高的主要组分,是４个亚种所共有的。方形黄鼠蚤在我国境内分布有４个亚种即松江亚种、蒙古     

两种未吸血幼蚤的耐饥力

1990年在实验室内观察了二齿新蚤和方形黄鼠蚤松江亚种末吸血幼蚤的耐饥力。证明新羽化蚤在不供给血液条件下也能存活很长或较长时间。共存活时间的长短,与环境温度、湿度有明显关系,而雌雄却无明显差别。     

草原黄鼠寄生蚤的季节变化

内蒙西部地区啮齿动物种类较多,分布亦广,如草原黄鼠(Citellus dauricus)即为北方常见鼠类,过去是鼠间鼠疫发生率较高者。其寄生蚤类作为鼠疫媒介已有记载,为了进一步了解蚤类的季节变化及黄鼠的出现季节作为灭鼠及控制或消灭媒介蚤种提供依据。我们在某牧区选点,每旬放鼠夹收回后登记鼠只,固定蚤类标本。按月记录采集的黄鼠只数及其寄生蚤的数目,视其季节变化,为蚤类传播鼠疫及其他动物源疾病的传播提供分类与生态的根据。     

我国新蚤属斯氏组(stevensi group of Neopsylla)的分类研究及新种新亚种记述(Siphonaptera:Hystrichopsyllidae)

我国的新蚤属已知有18个种和亚种,其中有12种和亚种属于多毛组,6种属于斯氏组。著者等今整理了从云南、贵州、福建和陕西四省所得到的斯氏组新蚤,除尊新蚤和异种新蚤未获得以外共记述了10种和亚种。其中无规新蚤和福建新蚤为已知种,不同新蚤为我国新记录,均作了补充记述。另外还发现了斯氏新蚤的雌性。本种系Rothschild 氏于1915年根据采自尼泊尔-锡金边境的一只雄蚤而记述。至1932年Jordan氏根据从四川得到的标本记述了雌性形态。本文根据从云南获得的雌雄性标本,重新记述了雌性形态,并由于早先文献中证据的不足和结论的可疑提出Jordan氏1932年记述的雌蚤并非本种,可能是其他种新蚤的雌性。 本文记述了两个斯氏组的新种:1)相关新蚤新种,采自云南中甸 Apodemus agrarius;2)二毫新蚤新种,采自云南中甸 A.agrarius(?E.proditor)。另外,对特新蚤进行了种下分类,提出特新蚤乃一多型物种,根据其种群特征将所得标本分别订为三个地理亚种:(1)云南大理的为特特新蚤;贵阳的为贵阳特新蚤;福建的为闽北特新蚤。 最后编制了我国斯氏组新蚤12个种和亚种的分类检索表。     

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.