高原型藏羊和小尾寒羊睾丸小叶及附睾微动脉的解剖学特征

分别从青海和甘肃采集高原型藏羊(Ovis aries)和小尾寒羊睾丸各20枚,用血管铸型技术和扫描电镜方法,研究两品种绵羊睾丸小叶及附睾微动脉的超微形态特征。结果显示,两品种绵羊的睾丸小叶及附睾微动脉走形呈一定程度的弯曲,其中睾丸小叶内离心动脉、离心小动脉及向心小动脉均呈"树枝"状分布。研究发现,与低海拔地区的小尾寒羊相比,高原型藏羊睾丸的绳结状动脉具有更密集的螺旋状排布,小动脉分支也较多,并且向心动脉、绳结状动脉、离心动脉、附睾头微动脉的管径也较粗。此外,高原型藏羊睾丸小叶和附睾头微动脉表面的"梭形"压痕较浅,而小尾寒羊的则较深;高原型藏羊睾丸小叶毛细血管前微动脉的表面缢痕较多且密集,而小尾寒羊的则相对少而稀疏。研究认为,高原型藏羊睾丸小叶及附睾微动脉的超微形态特征,有利于血管的收缩、睾丸供血及高原环境下精子的成熟,是睾丸对高原环境的适应性特征。     

成年牦牛心室壁微血管的形态特征

用ABS血管铸型、扫描电镜观察法和血管炭素墨水灌注、组织切片法研究了成年牦牛心脏微血管的构筑特征,首次对各级微血管的管径和毛细血管的密度进行了测量,并对成年牦牛心室壁的微血管进行了分类.结果显示:成年牦牛心脏微动脉、毛细血管前微动脉和毛细血管的管径平均值分别为为 78.50±10.23 μm ,16.24±2.27 μm ,6.57±2.28 μm.其管径范围分别为12.5～100 μm,12.50～19.99 μm,6.25～12.50 μm.成年牦牛心脏微动脉一般经3-4级分支才发出毛细血管,其第一、第二、第三和第四级分支的管径平均值分别为87.64±4.87 μm, 69.46±6.67 μm, 48.52±5.77 μm,30.45±5.44 μm.其范围分别为79.55～95 μm, 59.31～79.55 μm,37.50～59.31 μm,19.99～37.50 μm.成年牦牛心肌层毛细血管的密度为2 528±263根/mm2,靠近心外膜处毛细血管的密度为1 864±179根/mm2,心内膜毛细血管的密度为1 636±235根/ mm2.成年牦牛心脏微动脉铸型表面呈典型的"树皮样"结构,偶尔可见卵圆形的内皮细胞核压痕.成年牦牛心脏毛细血管前微动脉铸型形态呈锥状,铸型表面有环行缩窄.成年牦牛心脏的毛细血管铸型表面光滑,有环形缩窄,无内皮细胞核压痕.成年牦牛心肌层中毛细血管与心肌纤维平行,并形成"H"形或"Y"形的广泛吻合,而在靠近心内膜处毛细血管形态较为扭曲,毛细血管多形成平面或立体的吻合.成年牦牛心脏微静脉管径多在300 μm以下,管腔扁且不规则,微静脉铸型呈"树根"样结构.     

榆林沙蜥肺微血管铸型的扫描电镜观察

用扫描电镜观察ＡＢＳ丁酮溶液灌注的榆林沙蜥肺微血管构筑情况。榆林沙蜥肺壁内面有许多网状隔膜及肺泡隔将其分隔成许多肺泡囊及肺泡,在网状隔膜、肺泡隔及肺泡壁上均有丰富的毛细血管。且相互吻合成单层密集网,多为圆形、椭圆形及不规则形,网眼多由５－６支毛细血管围成。微动脉及毛细血管铸型表面光滑,可显示有内皮细胞核的压迹。     

成年与幼年高原型藏绵羊性腺动脉血管构筑比较

本实验旨在制作成年和幼年高原型藏绵羊(Ovis aries)的性腺动脉构筑标本,并比较其解剖学特征。分别从10只成年羊(雌雄各半)及10只3月龄幼年羊(雌雄各半)采集睾丸及卵巢样本,用8%~10%ABS铸型剂通过睾丸动脉或卵巢动脉灌注,再用浓盐酸腐蚀,获得动脉血管立体构筑标本,通过标本观察、图片采集、数据测定后进行分析。结果显示,绵羊精索内睾丸螺旋动脉呈椎体分布,直段动脉从睾丸中部分支,迂曲动脉构筑呈网兜状;卵巢动脉的卵巢支呈紧密螺旋状线圈分布,卵巢门动脉亦呈高度盘曲折叠状,其末端形成卵泡和黄体微动脉。研究发现,成年高原型藏绵羊睾丸和卵巢动脉血管的基本分布与普通牛(Bos taurus)的类似,成年羊与3月龄幼年羊的睾丸和卵巢动脉在管径大小、盘曲程度、微动脉多寡等方面存在显著差异,特别是成年羊的睾丸向心小动脉、卵巢门螺旋动脉更发达。     

大鼠脑血管颈内动脉系肾上腺素能神经起源的观察

应用免疫组织化学技术,观察了30只Wistar大鼠脑血管颈内动脉系肾上腺素能神经的起始核团。正常组脑血管颈内动脉系均可见棕褐色的免疫反应阳性纤维。手术1组作一侧颈上神经节切除术,同侧大脑前动脉、大脑中动脉和大脑后动脉的阳性纤维较正常组减少约2／3,对侧同部位动脉的阳性纤维约减少1／3;手术Ⅱ组作双侧颈上神经节切除术,双侧大脑前动脉、大脑中动脉和大脑后动脉的阳性纤维基本消失。结果提示：脑血管一侧颈内动脉系的肾上腺素能神经纤维起源于双侧颈上神经节。讨论了交感神经对脑血管可能的作用。     

Xia虎鱼寄生车轮虫两新种的记述

记述了寄生在魎虎鱼体表、鳃和口腔的两种新车轮虫一种为东湖车轮虫,新种(Trichodinadonghuensissp.nov.),虫体直径49.2-60μm,附着盘直径44.0(37.2-51.5)μm,齿环直径22.1(19.2-26.4)μm,齿体数目22-28个,以23-24个居多,辐线8根,口带绕体围410°,大核马蹄形,其外径20.4μm,核臂宽4.8-5.4μm,小核短杆状,长2.4μm,宽1.4μm.另一种为车轮虫,新种(Trichodinactenogobiisp.nov.),虫体直径62.4-81.8μm,附着盘直径63.9(56.4-72.0)μm,齿环直径33.3(31.8-38.4)μm,齿体数目23-27个,辐线数10-14根,以11根者居多,口带绕体围400°.大核马蹄形,核臂粗细不一,大核外径42.0μm.小核卵圆形,位于大核左臂前方.     

18β-甘草次酸对Wistar大鼠脑微动脉平滑肌细胞间缝隙连接的影响

目的：探讨18β-甘草次酸对Wistar大鼠脑微动脉平滑肌细胞间缝隙连接的影响,为寻求强效和可逆的缝隙连接阻断剂提供实验依据。方法：去除脑微动脉段外层结缔组织后,应用全细胞膜片钳技术,观察不同种类的缝隙连接阻断剂对Wistar大鼠脑微动脉段上平滑肌细胞膜电容（Cinput）、膜电导（Ginput）和膜电阻（Rinput）的影响。结果：（1）Wistar大鼠脑微动脉段上平滑肌细胞Cinput高于消化分离的单个平滑肌细胞。（2）18β-甘草次酸（18pGA）能浓度依赖性的抑制Wistar大鼠脑动脉平滑肌细胞间的缝隙连接,IC50分别为2．0μM。当18βGA100μM时,Wistar大鼠脑微动脉段上平滑肌细胞的Cinput、Ginput或Rinput与单个平滑肌细胞十分接近。结论：1813GA可以浓度依赖性的抑制Wistar大鼠脑微动脉平滑肌细胞间缝隙连接。     

正常成人脑主要供血动脉的MSCT血管成像研究

目的:观测正常脑动脉多层螺旋CT血管成像(multi-slice spiral CT angiography,MSCTA)主要动脉的起始部内径、走行、形态及其分支的显示情况,为脑血管疾病的诊断提供参考资料.方法:选择40例健康体检者行全脑血管64层MSCTA检查,采用ADW4.2工作站测量各主要动脉起始部内径,观测其走行、形态和变异,并统计各级分支的显示率.结果:正常成人脑动脉常见的变异发生在组成脑底动脉环的大脑前动脉A1段、前后交通动脉及大脑后动脉起始段,以后交通动脉变异最大.颈内动脉末段、大脑前动脉A1段、大脑中动脉、大脑后动脉、眼动脉、前交通动脉、后交通动脉及脉络膜前动脉在MSCTA上的显示率分别为100%、95%、100%、100%、100%、92.5%、58.8%和72.5%.主要脑动脉起始部内径分别是:颈内动脉末段4.013±0.770 mm、大脑前动脉A1段2.709±0.877 mm、大脑中动脉3.498±0.640 mm、大脑后动脉2.025±0.608 mm、眼动脉1.640±0.334 mm、后交通动脉1.491±0.697mm及脉络膜前动脉1.460±0.483mm.结论:正常成人脑血管变异主要发生于脑底动脉环,脑血管直径与其供血范围及分布区血流动力学因素相关.     

豚鼠不同部位微动脉平滑肌细胞电生理学特性的比较

本研究应用电生理技术在豚鼠离体小脑前下动脉(anterior inferior cerebellar artery,AICA)、肠系膜动脉(mesenteric artery,MA)和耳蜗螺旋动脉(spiral modiolar artery,SMA)分支(直径小于100μm)上比较微动脉平滑肌细胞电生理学特性的异同。结果显示:(1)应用细胞内微电极记录技术测得AICA、MA和SMA细胞静息膜电位分别为(-68±1.8)(n=65)、(-71±2.4)(n=80)和(-66±2.9)mV(n=58),各微动脉间无统计学差异。(2)一段血管微动脉标本全细胞膜片钳记录的平滑肌细胞膜电容和膜电导都远大于单个细胞标本,且微动脉间存在统计学差异,大小顺序为MAAICASMA。应用缝隙连接阻断剂2-APB(100μmol/L)后记录一段微动脉平滑肌细胞膜电容和膜电导与单个细胞十分接近。(3)AICA、MA和SMA单个平滑肌细胞膜电流I/V关系呈明显的外向整流特性,都对1mmol/L4-AP和10mmol/LTEA敏感。当指令电压为+40mV时,AICA、MA和SMA血管平滑肌细胞电流密度分别为(26±2.0)、(24±1.7)和(18±1.3)pA/pF,SMA和AICA、MA间存在统计学差异。上述结果提示,豚鼠不同部位微动脉平滑肌细胞在缝隙连接耦联力和电流密度等电生理特性存在差异。     

花背蟾蜍脉络膜毛细血管铸型的扫描电镜观察

用扫描电观察了ＡＢＳ丁酮溶液灌注的花背蟾蜍脉络膜毛细血管构筑情况。结果显示花背蟾蜍脉络膜毛细血管排民层并相互吻合成密集网,毛细知管管径８－２４μｍ。脉络膜前部毛细血管网较疏松,网眼孔径为７－３０μｍ,后部毛细血管网较密集,网眼孔径为６－１５μｍ,脉络膜后部细血和突然终止于视神经周围。不参与视神经乳头血液供应,毛细血管铸型表面光滑,显示有内皮细胞核压迹。     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor