冷冻或冷藏东亚飞蝗的循环系统解剖与观察

在动物学实验中使用冷冻或冷藏处理的东亚飞蝗进行解剖,可以展示饱满的心脏、大血管、翼状肌、背膈及中胸和后胸血液循环辅搏器等结构。通过中、后胸部血液循环辅搏器可以确定大血管的位置。该方法在教学上取得了良好的效果。     

昆虫心肌电位的细胞内记录

<正> 昆虫有一条从头部到腹部末端,沿背壁中线纵向延伸的背血管,背血管借心翼肌附着在背壁上,可以分为背动脉和心脏。背动脉位于头胸部,无收缩搏动功能。心脏位于腹部,按体节膨胀成心室,每心室的两侧各有心门一个。心脏可以收缩搏动。昆虫的循环系统是开放式的。血淋巴由背动脉流出,从头部向后在体腔内的各组织和器官间流动。血淋巴不象高等动物的血液那样,具有输送氧和二氧化碳的功能。因     

甜菜夜蛾胚胎发育的研究(Ⅱ)--体腔、体壁、循环系统和部分器官的发育

详细研究了甜菜夜蛾Spodoptera exigua(Hubner)在胚胎发育中体腔、肌肉、体壁、循环系统、丝腺、脂肪体和绛色细胞的发育过程,并总结了25℃下甜菜夜蛾胚胎发育的时间进度.体腔囊出现后,中胚层分为腹壁中胚层和背壁中胚层,前者将来形成体壁肌、脂肪体等,后者主要形成消化道外的肌肉层;腹壁中胚层与背壁中胚层交界处的细胞发育成成心细胞,随着背合的完成形成心脏,并与头部伸出的大动脉相接,形成背血管;胚胎发育到50h左右,体壁真皮细胞开始分泌含几丁质的表皮,幼虫孵化前,其体表布满脊突和刚毛;绛色细胞由胚体1～8腹节的外胚层部分细胞发育而成.     

鼠兔子宫血管铸型的光镜和扫描电镜观察

用光镜和扫描电镜观察了ＡＢＳ丁酮溶液灌注的达乌尔鼠兔子宫血管与微血管构筑情况。子宫大部分血液来自子宫动脉,小部分来自生殖动脉。各弓状动脉进入宫壁后,即在宫壁内分支形成３个血管层：浆膜层、大血管层和粘肌层。研究发现鼠兔子宫内膜血管呈树杆状或有轻度弯曲向腔面垂直穿行,直至浅层分支形成毛细血管网和较大的窦状毛细血管;其内膜血管形态与有月经的人子宫内膜螺旋动脉明显差异。文中还对子宫微血管构筑与月经产生机制     

原矛头蝮蛇毒对小鼠器官形态的影响

目的:观察原矛头蝮(P.mucrosquamatus)蛇毒对小鼠脏器形态结构的影响,从组织学角度探讨该蛇毒的致病机理。方法:用原矛头蝮攻击小鼠,待小鼠死亡后,立即进行解剖,观察心脏和大血管内部血栓形成情况。取心脏、血管、周围神经、肾脏、肝脏、脾脏和肺,观察外形,并进行石蜡切片,H.E染色观察。用健康小鼠相同器官为对照,比较二者的差异。结果:被原矛头蝮攻击致死小鼠的心脏、肝脏和肺发生了显著收缩;心腔和血管腔被血栓堵塞;在心脏、肝脏和肾脏组织血管中观察到了血栓;脾脏中白细胞显著增多;肺泡收缩,细支气管严重收缩致管腔堵塞;股动脉血管内膜发生了脱落;在股神经中发生了脱髓鞘现象。结论:急性凝血和窒息是导致小鼠死亡的重要原因;原矛头蝮蛇毒兼具血循毒和神经毒的特征;原矛头蝮蛇毒可导致多种脏器内部结构发生改变。     

华美游仆虫细胞微管胞器的直接荧光和免疫荧光标记

应用直接荧光和免疫荧光标记显示,腹毛目纤毛虫华美游仆虫(Euplotes elegans)细胞微管胞器由口围带、波动膜、额腹横棘毛、缘棘毛、尾棘毛、背触毛等纤毛器微管以及纤毛器基部附属微管和非纤毛区皮层微管骨架组成.其中,口围带基部含有小膜托架、小膜附属微管,波动膜基部含有波动膜托架,额腹横棘毛基部含有前纵微管束、后纵微管束、横微管束或放射微管柬,左缘棘毛和尾棘毛基部微管束分化不明显,背纤毛基部含有攻瑰花状的基体周围骨架,这些微管结构与细胞背腹面皮层纵微管与横微管网一起组织成该类纤毛虫的主要皮层细胞骨架.结果表明,游仆虫皮层细胞骨架是以微管为主要成分构建而成的,并且其棘毛基部微管的组成具有与其他类纤毛虫不同的特征;游仆虫间期细胞及形态发生时期纤毛基体或纤毛原基中存在中心蛋白,其可能与纤毛基体结构的维持及基体发生过程中微管的组装有关.     

新型金属蛋白酶ADAMTS-7促进体内和体外血管平滑肌细胞增殖

血管平滑肌细胞增殖和迁移对动脉粥样硬化和血管成型术后再狭窄的发生具有重要作用.本课题组之前的研究发现,含Ⅰ型血小板结合蛋白基序的解聚蛋白样金属蛋白酶ADAMTS-7能够通过调节血管平滑肌细胞迁移直接促进新生内膜的形成.然而ADAMTS-7是否影响血管平滑肌细胞增殖尚不清楚.本研究发现,腔内给予腺病毒造成在体ADAMTS-7过表达能够明显促进大鼠血管损伤7天后新生内膜的形成.PCNA阳性细胞比例在过表达ADAMTS-7的血管内膜和中膜中明显增多.此外,利用血管外膜涂抹小干扰RNA的技术沉默ADAMTS-7体内表达.结果表明,与对照组相比,敲低ADAMTS-7能够明显抑制内膜增厚和内膜平滑肌细胞增殖,但是并不影响中膜细胞.3H掺入实验结果表明,过表达ADAMTS-7能够明显促进体外培养的原代血管平滑肌细胞增殖,基因沉默则抑制其增殖.综上所述,新型金属蛋白酶ADAMTS-7能够在体内和体外促进血管平滑肌细胞增殖.本研究结果提示,ADAMTS-7可能成为防治动脉粥样硬化和血管成型术后的再狭窄的新作用靶点.     

64层螺旋CT增强扫描在急诊胸部创伤中的初步应用

目的：探讨64层螺旋CT增强扫描在急诊胸部创伤中的诊断价值及临床意义。方法：18例急诊胸部创伤患者均行胸部64层螺旋CT平扫及增强扫描。采用最大密度投影（MIP）、曲面重建（CPR）和容积再现技术（VR）对胸部大血管进行重建、分析。将CT诊断结果与手术、随访复查结果进行比较。结果：18例中,CT平扫显示胸部主要损伤有：肺挫伤10例（55.56%）,血胸及肋骨骨折各9例（50%）,气胸8例（44.44%）,锁骨骨折6例（33.33%）。CT增强扫描诊断心脏大血管损伤7例,其中锁骨下动脉假性动脉瘤3例,胸主动脉假性动脉瘤2例,胸主动脉夹层和心包破裂各1例。CT增强扫描结果与手术、临床随访结果相吻合。结论：64层螺旋CT增强扫描是全面而准确地诊断急诊胸部创伤的重要影像技术,可以对CT平扫不能确定的心脏、大血管的损伤情况作出明确判断,对临床救治方案的早期确定具有重要的指导意义。     

无恒拟小胸虫的形态及形态发生

拟小胸虫属(Pseudomicrothorax)是一类稀见的淡水纤毛虫,至今只发现了两个种。1958年以前这个属归全毛类(Holotricha)毛口亚目(Trichostomata)(Kahl 1931;Kudo,1954)。Thompson及Corliss(1958)用银浸法研究了无恒拟小胸虫(P.dubius)的形态及形态发生,发现其口胞器的结构与原属的毛口亚目无任何共同之点,而与膜口目(Hymenostomatida),特别是四膜亚目(Tetrahymena)相似。因此他们将其归属于膜口目。早     

草丛土毛虫皮层纤毛器的微管胞器研究

本文应用FLUTAX直接荧光标记和抗α-微管蛋白抗体免疫荧光标记．显示了土壤纤毛虫草丛土毛虫（Territricha stramenticola）的皮层纤毛器微管胞器．其中纤毛器基部微管按口围带、波动膜、额腹横棘毛、左右缘棘毛、背触毛等纤毛器图式分布和定位,口围带和波动膜基部含小膜微管托架、小膜附属微管和波动膜微管骨架网;额腹横棘毛基部含前纵微管束、后纵微管束和横微管束：左、右缘棘毛基部含前纵微管束、后纵微管束、横微管束及后微管芽;背触毛基部含前纵微管束、后纵微管柬。横棘毛基部含有较发达的横微管束,缘棘毛基部含后微管芽及其横微管束的定位可能具有本种纤毛虫细胞的特异性。纤毛器微管胞器在细胞表膜下分化形成的基部微管及其微管层使细胞的运动纤毛器与强固的微管骨架结构网相联系．其微管胞器的建构可能是细胞对土壤生存环境的一种适应．是细胞运动胞器的功能活动与环境相互作用的结果。形态发生中,老口围带微管是逐步进行更新的：老棘毛微管胞器对新结构的发生和形成具有定位和物质贡献的作用．并且老结构在新结构分化和成熟期间也经历了行使相应的生理功能及逐渐退化和失去功能的过程．     

Functional morphology of the heart and of a new cephalic pulsatile organ in the blowfly Calliphora vicina (Diptera: Calliphoridae) and their roles in hemolymph transport and tracheal ventilation

In the blowfly Calliphora vicina (Diptera: Calliphoridae), the morphology of the dorsal vessel and of a new cephalic accessory pulsatile organ (CPO) were analysed with light-microscopic, SEM and TEM techniques. The CPO and neck aorta are reconstructed 3-dimensionally by computer-aided design. The pulse activity of the CPO and of the heart was measured in intact flies over periods of several hours or days using contact-thermography with laser beam heat-marking. The intratracheal pressure was simultaneously measured at the anterior thoracic spiracle. The dorsal vessel is constructed of pairs of left–right alternating cells. Its enlarged chamber in the anterior abdomen contains two pairs of incurrent ostia, its posterior narrower heart tube possesses three pairs of incurrent ostia and paired caudal excurrent openings. The aorta opens with a funnel-like opening in the neck. Proportions, arrangement and ultrastructure of the aorta, heart cells and pericardial muscles are described. Cushionlike sarcoplasmic protrusions of heart cells (pair no. 17) probably function as internal valves. The neck aorta is constructed of a cuticular ‘roof’ deviating from the dorsal neck membrane and a ventral longitudinal muscle ‘floor’. The aorta is not kept open because of missing muscle or connective tissue strands. The underside of the CPO is fused with air sacs that function as antagonists to the muscles. The heart reverses its beat periodically in resting and active flies. During the longer forward-pulse periods, mean frequency is lower (about 3.0 Hz at Ta 20°C), during the shorter backward periods mean frequency is higher (4.6 Hz). The CPO beats only during forward-pulse periods of the heart with an independent and slower pulse rate (1.8 Hz). The CPO-pulses produce positive pressure pulses at the anterior thoracic spiracle. During backward-pulse periods of the heart and pulse pause of the CPO, a continuous negative pressure arises at the thoracic spiracle instead of pressure pulses. The intimate connection of an accessory pulsatile organ with tracheal air sacs makes it work as a bifunctional pump for hemolymph distribution and tracheal ventilation. Neurosecretory and synapsing innervation of the CPO in connection with aorta, heart and pericardial septum muscle innervation suggest that both organs are regulated and that the duration of their periods is neuronally coordinated.     

Homeotic selector genes control the patterning of seven-up expressing cells in the Drosophila dorsal vessel

The linear cardiac tube of Drosophila, the dorsal vessel, is an important model organ for the study of cardiac specification and patterning in vertebrates. In Drosophila, the Hox segmentation gene abdominal-A (abd-A) is required for the specification of a functionally distinct heart region at the posterior of the dorsal vessel, from which blood is pumped anteriorly through a tube termed the aorta. Since we have previously shown that the posterior part of the aorta is specified during embryogenesis to form the adult heart during metamorphosis, we determined if the embryonic aorta is also patterned by the function of Hox segmentation genes. Using gain- and loss-of-function experiments, we demonstrate that the three Hox genes expressed in the posterior aorta and heart are sufficient to confer heart or posterior aorta fate throughout the dorsal vessel. Additionally, we demonstrate that Ultrabithorax and abd-A, but not Antennapedia, function to control cell number in the dorsal vessel. These studies add robustness to the model that homeotic selector genes pattern the Drosophila dorsal vessel, and further extend our understanding of how the cardiac tube is patterned in animal models.     

The Hox gene abdominal-A specifies heart cell fate in the Drosophila dorsal vessel

The Drosophila melanogaster dorsal vessel is a linear organ that pumps blood through the body. Blood enters the dorsal vessel in a posterior chamber termed the heart, and is pumped in an anterior direction through a region of the dorsal vessel termed the aorta. Although the genes that specify dorsal vessel cell fate are well understood, there is still much to be learned concerning how cell fate in this linear tube is determined in an anteroposterior manner, either in Drosophila or in any other animal. We demonstrate that the formation of a morphologically and molecularly distinct heart depends crucially upon the homeotic segmentation gene abdominal-A (abd-A). abd-A expression in the dorsal vessel was detected only in the heart, and overexpression of abd-A induced heart fate in the aorta in a cell-autonomous manner. Mutation of abd-A resulted in a loss of heart-specific markers. We also demonstrate that abd-A and sevenup co-expression in cardial cells defined the location of ostia, or inflow tracts. Other genes of the Bithorax Complex do not appear to participate in heart specification, although high level expression of Ultrabithorax is capable of inducing a partial heart fate in the aorta. These findings for the first time demonstrate a specific involvement for Hox genes in patterning the muscular circulatory system, and suggest a mechanism of broad relevance for animal heart patterning.     

Scanning electron microscopy of the dorsal vessel of Panstrongylus megistus (Burmeister, 1835) (Hemiptera: Reduviidae).

In this study we analyzed the microanatomy of the dorsal vessel of the triatomine Panstrongylus megistus. The organ is a tubule anatomically divided into an anterior aorta and a posterior heart, connected to the body wall through 8 pairs of alary muscles. The heart is divided in 3 chambers by means of 2 pairs of cardiac valves. A pair of ostia can be observed in the lateral wall of each chamber. A bundle of nerve fibers was found outside the organ, running dorsally along its major axis. A group of longitudinal muscular fibers was found in the ventral portion of the vessel. The vessel was found to be lined both internally and externally by pericardial cells covered by a thin laminar membrane. Inside the vessel the pericardial cells were disposed in layers and on the outside they formed clusters or rows.     

Gill microcirculation of the air-breathing climbing perch, Anabas testudineus (Bloch):relationships with the accessory respiratory organs and systemic circulation

The general macrocirculation and branchial microcirculation of the air-breathing climbing perch, Anabas testudineus, was examined by light and scanning electron microscopy of vascular corrosion replicas. The ventral aorta arises from the heart as a short vessel that immediately bifurcates into a dorsal and a ventral branch. The ventral branch distributes blood to gill arches 1 and 2, the dorsal branch to arches 3 and 4. The vascular organization of arches 1 and 2 is similar to that described for aquatic breathing teleosts. The respiratory lamellae are well developed but lack a continuous inner marginal channel. The filaments contain an extensive nutritive and interlamellar network; the latter traverses the filament between, but in register with, the inner lamellar margins. Numerous small, tortuous vessels arise from the efferent filamental and branchial arteries and anastomose with each other to form the nutrient supply for the filament, adductor muscles, and arch supportive tissues. The efferent branchial arteries of arches 1 and 2 supply the accessory air-breathing organs. Arches 3 and 4 are modified to serve primarily as large-bore shunts between the dorsal branch of the ventral aorta and the dorsal aorta. In many filaments from arches 3 and 4, the respiratory lamellae are condensed and have only 1-3 large channels. In some instances in arch 4, shunt vessels arise from the afferent branchial artery and connect directly with the efferent filamental artery. The filamental nutrient and interlamellar systems are poorly developed or absent. The respiratory and systemic pathways in Anabas are arranged in parallel. Blood flows from the ventral branch of the ventral aorta, through gill arches 1 and 2, into the accessory respiratory organs, and then returns to the heart. Blood, after entering the dorsal branch of the ventral aorta, passes through gill arches 3 and 4 and proceeds to the systemic circulation. This arrangement optimizes oxygen delivery to the tissues and minimizes intravascular pressure in the branchial and air-breathing organs. The efficiency of this system is limited by the mixing of respiratory and systemic venous blood at the heart.     

ELECTRON MICROSCOPIC AND HISTOCHEMICAL COMPARISON OF THE TWO TYPES OF ELECTROPLAQUES OF NARCINE BRASILIENSIS

The torpedine electric fish Narcine brasiliensis has two morphologically distinct electric organs (main and accessory) which also differ with respect to a number of electrophysiological properties. The fine structure of the electroplaques of these organs has been examined by electron microscopy and by a histochemical method for localizing esterase activity with a high degree of resolution. In both kinds of electroplaques the innervated surface (ventral in those of the main organ, dorsal in those of the accessory) is the only site of esterase activity. The latter is further confined to the regions of synaptic contact between vesicle-containing axon terminals and the electroplaque membrane. The synaptic apparatus is similar to, but less elaborate than, that of neuromuscular junctions. The axon terminals and electroplaque membranes are free of connective tissue envelopments. The membrane of the uninnervated surfaces forms a continuum with a dense canalicular network which penetrates deeply into the 7 µ thick electroplaques of the main organ. The canalicular network has about the same thickness in the 20 µ electroplaques of the accessory organ. Except for this difference, the two kinds of cells appear to have the same fine structure. This finding is discussed in relation to the electrophysiological data on functional differences.     

Homeotic genes autonomously specify the anteroposterior subdivision of the Drosophila dorsal vessel into aorta and heart

The embryonic dorsal vessel in Drosophila possesses anteroposterior polarity and is subdivided into two chamber-like portions, the aorta in the anterior and the heart in the posterior. The heart portion features a wider bore as compared with the aorta and develops inflow valves (ostia) that allow the pumping of hemolymph from posterior toward the anterior. Here, we demonstrate that homeotic selector genes provide positional information that determines the anteroposterior subdivision of the dorsal vessel. Antennapedia (Antp), Ultrabithorax (Ubx), abdominal-A (abd-A), and Abdominal-B (Abd-B) are expressed in distinct domains along the anteroposterior axis within the dorsal vessel, and, in particular, the domain of abd-A expression in cardioblasts and pericardial cells coincides with the heart portion. We provide evidence that loss of abd-A function causes a transformation of the heart into aorta, whereas ectopic expression of abd-A in more anterior cardioblasts causes the aorta to assume heart-like features. These observations suggest that the spatially restricted expression and activity of abd-A determine heart identities in cells of the posterior portion of the dorsal vessel. We also show that Abd-B, which at earlier stages is expressed posteriorly to the cardiogenic mesoderm, represses cardiogenesis. In light of the developmental and morphological similarities between the Drosophila dorsal vessel and the primitive heart tube in early vertebrate embryos, these data suggest that Hox genes may also provide important anteroposterior cues during chamber specification in the developing vertebrate heart.     

The insect abdomen--a heartbeat manager in insects?

Different possibilities of coordination between circulation, respiration and abdominal movements were found in pupae of Pieris brassicae, Tenebrio molitor, Galleria mellonella and Leptinotarsa decemlineata. Coordination principles depend on metabolic rate: the need to support circulation with abdominal movements appears only at higher metabolic rates. Integration between different abdominal movements and circulation depends on species, on physiological state and, supposedly, on internal morphology. At low metabolic rates, there is no need for a very intensive hemolymph flow, and the dorsal vessel is capable of initiating and/or maintaining necessary hemolymph flow. Starting from a certain metabolic level, it is possible that the abdomen is used to accelerate hemolymph flow in the case of a large amount of hemolymph. When the necessary flow speed has been reached, relatively weak pulsation of the dorsal vessel with accessory pulsatile organs and diaphragms can easily maintain the necessary flow intensity. Heart activity may sometimes be initiated by abdominal movements via cardiac reflex or mechanical excitation. Sometimes, when heart function is weakened by histolysis, the abdomen may temporarily take over the main circulatory function or occasionally contribute to acceleration of low-speed hemolymph flow. In this case the functions are simultaneous and may be triggered by some mediator(s). In active adult insects the whole body is moving, and hence hemolymph circulates and the tracheal system is effectively ventilated by a whole body ensemble consisting of the dorsal vessel, moving organs, body appendages and accessory pulsatile organs. The mechanism of autocirculation (analogous to autoventilation in gas exchange) is a probable mechanism in circulation in adult insects.     

Heart development in Drosophila

The Drosophila heart, also called the dorsal vessel, is an organ for hemolymph circulation that resembles the vertebrate heart at its transient linear tube stage. Dorsal vessel morphogenesis shares several similarities with early events of vertebrate heart development and has proven to be an insightful system for the study of cardiogenesis due to its relatively simple structure and the productive use of Drosophila genetic approaches. In this review, we summarize published findings on Drosophila heart development in terms of the regulators and genetic pathways required for cardiac cell specification and differentiation, and organ formation and function. Emerging genome-based strategies should further facilitate the use of Drosophila as an advantageous system in which to identify previously unknown genes and regulatory networks essential for normal cardiac development and function.     

The Electrophysiology of Electric Organs of Marine Electric Fishes : II. The electroplaques of main and acccessory organs of Narcine brasiliensis

Studies on the electric organs of Narcine brasiliensis and particularly of the responses of the electroplaques of the accessory organ confirm and amplify data obtained on the electroplaques of Torpedo nobiliana. Only the innervated surface is electrogenically reactive and the uninnervated surface has a low resistance, as in Torpedo electroplaques. However, in the accessory organ of Narcine the innervated surface is the dorsal, rather than the ventral, and it has a different pattern of innervation. The responses of single cells of the accessory organ exhibit marked facilitation on repetitive stimulation. The facilitated responses, like the individual responses of Torpedo and of the main organ of Narcine, are electrochemically graded on changing the membrane potential with applied currents, and are inverted in sign when outward currents through the innervated face are very strong.