NaOH消蚀法制备人松果体脑砂的扫描电镜观察和化学元素分析

目的　为了探讨人松果体脑砂的结构特征和化学成分。方法　对经 Na OH消蚀处理的人松果体内脑砂 ,进行了扫描电镜观察和化学元素分析。结果　松果体组织块经用 Na OH消蚀处理后 ,其内部的脑砂能被清晰的暴露 ,并可制得单纯的脑砂样品。松果体脑砂大小不等 ,常呈桑椹状球形小体 ;既可存在于松果体的中央区 ,也可位于松果体的周边部。构成脑砂的化学元素 ,主要为钙 (5 4.82 % )和磷 (2 5 .83% ) ,还有少量银(16 .0 1% )和铁 (3.34% )等 ;钙 /磷比值约为 2 .12 / 1。结论　扫描电镜观察和化学元素分析的结果提示 ,脑砂似为矿物质在松果体内的逐渐沉积 ,更象是一种复杂的时间 -数量性矿化 ,而非简单的年轮样钙化。     

人松果体结缔组织纤维的构筑——消蚀法扫描电镜观察

为证明人松果体结缔组织纤维的排列，用消蚀扫描电镜法对该器官做了观察。松果体囊由胶原纤维束构成，囊表而可观察到大量由胶原纤维编织成的孔隙。起自囊的胶原纤维构成小叶间隔，分隔松果体实质为直径２００－４００μｍｊ的小叶。囊和隔由疏松排列的胶原细纤维构成。     

人松果体组织结构的退行性变化及其意义

目的:观察人松果体的细微和超微结构,探讨松果体内脑砂的形态特点、大小、多少及分布规律.方法:取人尸体的松果体,光镜、扫描和透射电镜观察其结构特征.结果:松果体主要由实质和间质两种成分构成;松果体实质由松果体细胞和神经胶质细胞组成,间质为结缔组织和穿行其中的神经和血管.脑砂多分布于松果体的中央部,常聚集形成较大的斑块.脑砂的大小、多少个体差异较大.变化趋势为随着年龄的增加,松果体内脑砂增多、增大,并伴有间质成分的结缔组织增生;然而,松果体实质成分减少;而且,在大量的松果体细胞内,可观察到颗粒空泡样变性.结论:松果体组织结构出现的退行性变化,可造成松果体神经内分泌功能的进行性减退.     

松果体分泌物释放入脑脊液主要通路的常规及消蚀法扫描和透射电镜研究

哺乳动物的松果体,为脑内一重要的神经内分泌器官。已发现脑脊液中存在松果体分泌物(如褪黑素Melatonin)。为探讨松果体分泌物直接释放入脑脊液通路的超微结构形态学证据。采用常规及NaOH消蚀法生物电镜样品制备技术,对成年日本猴松果体及其被囊进行了扫描和透射电镜研究。松果体囊由一层扁平上皮细胞和上皮下结缔组织构成。在面对蛛网膜下隙的囊上皮细胞和细胞间可见许多上皮孔(2～5μm);上皮下结缔组织内含成纤维细胞、胶原纤维、血管、松果体细胞突起(内含膜包密芯分泌颗粒)、有髓和无髓神经纤维等;它伸入松果体实质形成小叶间隔,分隔…     

大鼠实验性甲状旁腺功能减退的研究——Ⅰ.脑钙代谢变化

用电烫法去除大鼠双侧甲状旁腺(PTX),造成实验性甲状旁腺功能减退症(甲旁减)动物模型,经2个月低钙饲料喂养后,血清总钙和可扩散钙明显减少(各比对照组减少41％和48％),血清磷明显升高(增加84％)。PTX鼠脑的钙、磷含量亦随血清浓度有所改变,无显著差异,而脑的钙/磷比值明显降低。PTX鼠肾脏皮质cAMP和钙调素(CaM)含量明显减少,大脑皮层和纹状体CaM也明显降低,而脑突触体~(45)Ca摄取量显著增高。本文对上述结果与临床甲旁减所见脑钙化之间的关系进行了分析     

摘除松果体对大鼠学习记忆及基底前脑胆碱能系统的影响

目的　探讨松果体功能减退对大鼠学习记忆及基底前脑胆碱能系统的影响。方法　选用 3月龄SD大鼠 2 4只 ,随机分为对照组、去松果体组和褪黑素 (MT)组。手术摘除松果体。饲养 1个月后用Morris水迷宫测试学习记忆功能 ,同时用组织化学和免疫组化方法测定海马、前额叶皮质AchE纤维和内侧隔核、斜角带核的ChAT神经元的数量。结果　与对照组比较 ,去松果体组逃避潜伏期明显增加 ,海马、前额叶皮质AchE纤维数量明显减少 ,但内侧隔核、斜角带核的ChAT神经元数量变化不明显。结论　大鼠去松果体可引起大鼠学习记忆能力减弱 ,这可能与基底前脑胆碱能神经元的功能下降有关     

缰核

<正> 缰核(Habenular nucleus、Hb)是脑中古老的结构之一、位于松果体柄前部的两侧,曾被称为“松果体脚(Pineal peduncle)”、也被叫做“缰神经节(Habenular ganglion)”。有关Hb的发生、纤维联系、组织结构、递质和受体的资料很多、下面分别加以叙述。一、Hb的发生和比较解剖在中枢神经系统的种系发生中,脑一出现,就有了Hb,因此Hb堪称为脑的古老结构。最低等的脊椎动物一圆口动物已有Hb,这种动物具有发达的嗅功能,Hb非常显著,所以人们一直认为Hb多与嗅觉有关。圆口动物Hb的特点是,左右不对称,右侧大于左侧,一般认为这是由于很发达的松果体的纤维投射到右侧Hb,而较小的旁松果体的纤维投射到左侧Hb,     

猴松果体分泌物释放入脑脊液主要途径的结构基础电镜研究

目的 探讨松果体分泌物直接释放入脑脊液途径的开矿学依据,方法 采用常规及ＮaＯＨ 消蚀法电镜样品制备技术,对成年日本猴松果体及其补囊进行了扫描和航向电镜观察。结果松果体囊同一层扁平上皮细胞和上皮下结缔组织构成。在面对蛛网膜下隙的囊上皮细胞和细胞间存在许多上皮孔;上上结缔组织什入要体形成小叶间隔,浆松果体分隔为许多实质小叶。松果体结缔组织的主要成分为胶原纤维;实质小叶由大量松果体细胞和少数胶质细胞组成     

大鼠松果体内含5-羟色胺,血管活性肠多肽及P物质纤维的免疫组化观察

用免疫组化ABC法,研究了正常和摘除双侧颈上神经节后的大鼠松果体浅部内含5-羟色胺、血管活性肠多肽及P物质纤维.结果显示:(1)对照组松果体浅部内含5-羟色胺纤维非常丰富.且松果体细胞也呈阳性反应.实验组含5-羟色胺纤维显著减少,细胞的免疫反应强度也降低,与对照组相比,差异有显著性(P<0.01 ).(2)含血管活性肠多肽纤维主要分布在血管周围间隙,数量较少.实验组和对照组间纤维数量无明显差异.(3)含P物质纤维数量很少,呈典型的串珠状,主要分布在腺细胞之间.摘除双侧颈上神经节后对P物质纤维数量没有影响.     

具石棉样胶原纤维的脑膜瘤

目的 探讨脑膜瘤石棉样纤维的本质及其形成机制。方法 应用HE染色、组织化学、免疫组织化学染色及电镜观察l例具石棉样纤维的脑膜瘤的特点。结果 光镜下石棉样纤维为粗细均一的、呈放射状整齐排列的嗜酸性细丝构成的小体。ABPAS和网染小体周围带呈强阳性，中央中间带呈阴性。FN免疫组化染色小体边缘带阳性，中央中间带阴性。电镜下石棉样纤维由平行排列的胶原原纤维组成，与周围肿瘤组织内的胶原纤维有近似的周期和宽度，但原纤维平行排列呈放射状或栅状。结论 本例脑膜瘤，石棉样纤维是一种呈放射状排列的粗大胶原纤维，纤维沉积在球形或半球形的空隙内，小体周围瘤细胞与间质通过小体表面对小体具有均等的吸附力，使其呈放射状排列。     

Aging changes in the human aortic valve in relation to dystrophic calcification.

To elucidate the pathogenesis of aging changes and their relation to age associated calcification, a morphological study of 27 human aortic valves was carried out. Nine valves were obtained from immediate autopsies and 18 valves from routine autopsies done within four hours after death. Calcium deposition was present deep in the zona fibrosa along a zone of lipid accumulation. Fibrocytes in the zona fibrosa showed predominant age associated changes, i.e., a massive accumulation of residual bodies in the cytoplasm probably derived from autophagic vacuoles. Light microscopic lipid accumulation corresponded with both intracellular accumulation of electron dense spherules and membranous vesicles derived from degenerate fibrocytes. Calcium deposition in various stages, including needle shaped hydroxyapatite crystals, was seen in close association with these cellular degradation products rather than collagen or elastic fibers. Dystrophic calcification in the aortic valve appears to result from cellular aging and death followed by petrification of cellular degradation products, which may progress to calcific aortic stenosis.     

The nerve distribution in the testis of the cat

The autonomous innervation of the feline testis was investigated by immunohistochemistry and a modified acetylcholinesterase technique. The nerves reach the testis mainly by two routes: (1) with testicular artery and pampiniform plexus to the cranial extremity (funicular contribution), (2) from the epididymal tail to the caudal extremity (caudal contribution). Within the tunica albuginea the funicular contribution supplies the cranial two thirds, whereas the caudal third of the tunica receives its nerves via the ligamentous connection between testis and epididymal tail. The nerve bundles accompanying the testicular artery give branches to the arterial wall and the pampiniform plexus. When reaching the cranial testicular pole the bundles separate; the majority of them pass into the centrally located mediastinum testis, another large portion enters the tunica albuginea, particularly on its epididymal side. The septula testis are innervated from both sides, that is from the mediastinum and from the tunica albuginea. In the cat, contrary to other mammals, all septula are innervated. Furthermore, nerve fibers occur regularly within the testicular lobules. Generally, the testicular nerves of the cat are unmyelinated and mainly vascular nerves, but fibers are also found within the connective tissue compartments of the testis. The vast majority of all autonomous testicular nerves are postjunctional sympathetic fibers. Terminal ramifications of cholinergic fibers are exclusively observed in the wall of medium-sized arterioles within mediastinum, septula and lobuli testis. Neuropeptide Y is the most frequent peptidergic transmitter in feline testicular vascular plexuses. The amount of calcitonin gene-related peptide-positive fibers is also remarkably high in the testis, but prefers a location within the stroma of the tunica albuginea, mediastinum and septula. In the cat, Leydig cells occur not only in intertubular locations, but also as intratunical and mediastinal Leydig cells. In all three localizations solitary nerve fibers are observed between Leydig cell groups. These fibers are generally dopamin-beta-hydroxylase- and tyrosine hydroxylase-positive, some contain calcitonin gene-related peptide and, very few, substance P.     

Ultrastructure of the pineal body of the common vampire bat,Desmodus rotundus

The type AB pineal body of the common vampire bat, Desmodus rotundus was recessed and lobulated, was extensively vascularized and intimately related to great veins, and was unassociated with the epithalamic region. The habenular and the posterior commmissures coursed anteriorly and were unassociated with the pineal. The saccular suprapineal recess of the third ventricle extended dorsally juxtaposed to the pineal body. These anatomical features are likely to make pinealectomies in the vampire more difficult to manage. The pineal parenchyma consisted of light pinealocytes surrounded by canaliculi of various sizes, often transmitting unmyelinated nerve fibers and glial processes. Desmosomes were common. The pinealocyte nuclei were large and highly infolded; characteristic cytoplasmic constituents included abundant dilated Golgi complexes associated with clear vesicles, numerous polyribosomes, few single cisternae of ribosome-studded rough endoplasmic reticulum, mitochondria, and occasional multivesicular bodies and lysosomes. Almost all pinealocytes exhibited centrioles and some, in addition, displayed basal bodies but rarely ciliary shafts. A conspicuous feature of the pinealocyte cytoplasm was the presence of branched bundles of intermediate filaments, especially in the perinuclear zone. Siderotic macrophages, lipofuscin-pigment-containing phagocytic cells, mast cells, myelin bodies, and both fenestrated and continuous capillaries were present. The perivascular compartment was densely packed with unmyelinated nerve bundles containing small to large fibers exhibiting axoaxonic densities. Other constituents of the perivascular compartment were club-shaped pinealocyte processes filled with clear vesicles, microtubules, an occasional mitochondrion, glial processes, and collagen fibers. “Synapselike” contacts were observed between the axons and pinealocyte processes. Abundant pinocytotic vesicles in the capillary endothelium indicated active pinocytosis. Myelinated nerve fibers were lacking. The pineal ultrastructure of Desmodus is in part unlike that reported for other mammals, including bats.     

Peripheral autonomic nerves of human pineal organ terminate on vessels, their supposed role in the periodic secretion of pineal melatonin

Nonvisual pineal and retinal photoreceptors are synchronizing circadian and circannual periodicity to the environmental light periods in the function of various organs. Melatonin of the pineal organ is secreted at night and represents an important factor of this periodic regulation. Night illumination suppressing melatonin secretion may result in pathological events like breast and colorectal cancer. Experimental works demonstrated the role of autonomic nerves in the pineal melatonin secretion. It was supposed that mammalian pineals have lost their photoreceptor capacity that is present in submammalians, and sympathetic fibers would mediate light information from the retina to regulate melatonin secretion. Retinal afferentation may reach the organ by central nerve fibers via the pineal habenulae as well. In our earlier works we have found that the pineal organ developing from lobular evaginations of the epithalamus differs from peripheral endocrine glands and is composed of a retina-like central nervous tissue that is comprised of cone-like pinealocytes, secondary pineal neurons and glial cells. Their autonomic nerves in submammalians as well as in mammalian animals do not terminate on pineal cells, rather, they run in the meningeal septa among pineal lobules and form vasomotor nerve endings. Concerning the adult human pineal there are no detailed fine structural data about the termination of autonomic fibers, therefore, in the present work we investigated the ultrastructure of the human pineal peripheral autonomic nerve fibers. It was found, that similarly to other parts of the brain, autonomic nerves do not enter the human pineal nervous tissue itself but separated by glial limiting membranes take their course in the meningeal septa of the organ and terminate on vessels by vasomotor endings. We suppose that these autonomic vasomotor nerves serve the regulation of the pineal blood supply according to the circadian and circannual changes of the metabolic activity of the organ and support by this effect the secretion of pineal neurohormones including melatonin.     

Expression of type VII collagen,the major anchoring fibril component,in normal and neoplastic human nervous system

The distribution of type VII collagen was examined in the normal human nervous system, in brain tumour biopsies and in glioma cell lines by immunohistochemistry and western blotting. In normal tissue, positivity was observed beneath choroid plexus epithelial cells and around pineal gland and pituitary gland cell nests, while other brain regions and peripheral nerves were negative. Expression was preserved in most related tumours (choroid plexus papilloma, pineoblastoma, pituitary adenoma). Scattered abnormal vessels showed neoexpression of type VII collagen in about half of the astrocytic and ependymal tumours. Glioma cells in situ were consistently negative for type VII collagen, where-as the glioblastoma cell lines were positive. Our results suggest that anchoring fibrils or at least epitopes of their major structural component are present in normal and pathological cerebral structures, indicating a unique distribution of type VII collagen in the nervous system.     

Scanning electron microscopy study of the palatine salivary glands of rabbits

The structure of the palatine salivary glands of rabbits was studied employing scanning electron microscopic methods. The fractured surface of the palatine salivary glands revealed that they were formed of small lobuli separated by interlobular spaces containing numerous bundles of collagen fibers. The NaOH treated specimens showed the organization of the collagen fibrils in their original location. In the interstitial stroma compartment, the collagen fibrils revealed a complex three-dimensional arrangement forming channel-like structures for supporting nerve fibers, small vessels and capillaries. Single groups of acinar cells were clearly demonstrated, and each acinus was enveloped by a characteristic basal lamina showing a sponge-like structure made up of several interconnected meshes of collagen fibrils. Furthermore, taking advantage of the ODO method and field emission scanning electron microscopy, within the cytoplasm of secretory acinar cells numerous organelles were clearly observed in a three-dimensional way such as Golgi complex lamellae, rough endoplasmic reticulum, mitochondria and secretory granules. All these cytoplasmic components revealed their real and microtopographical arrangement in some areas of the acinar cytoplasm clearly suggesting their direct involvement in energetic as well as secretory activities.     

A Scanning Transmission Microscopy and Energy-Dispersive X-ray Microanalysis of Idiopathic Ocular Calcification and Oxalosis in AIDS Patients

In a series of 98 consecutive eyeballs enucleated at postmortem from 86 patients dying with AIDS, the incidence of calcium deposits was 14 and 18.6%, respectively, for oxalates and calcium hydroxyapatite. The calcific eyes were examined by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray microanalysis to confirm the elemental nature of the precipitates. Transmission electron microscopy was used in 2 of the cases with oxalosis. Oxalates with a free end exhibited a plate-like shape at SEM and appeared acicular at TEM, due to the reduced thickness of ultrathin sections. Crystals that were embedded in tissues such as the sclera or degenerate detached retinal tissue formed either spherules or plates at SEM. No clear relationship with intracellular structures could be found at TEM, possibly due to postmortem autolysis phenomena. Calcium hydroxyapatite deposits appeared at SEM as fine granules distributed over the collagen fibers of the corneal and conjunctival stroma and the scleral lamellae, but were also present intracellularly, both in the nucleus and cytoplasm of epithelial cells.     

A scanning transmission microscopy and energy-dispersive X-ray microanalysis of idiopathic ocular calcification and oxalosis in AIDS patients.

In a series of 98 consecutive eyeballs enucleated at postmortem from 86 patients dying with AIDS, the incidence of calcium deposits was 14 and 18.6%, respectively, for oxalates and calcium hydroxyapatite. The calcific eyes were examined by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray microanalysis to confirm the elemental nature of the precipitates. Transmission electron microscopy was used in 2 of the cases with oxalosis. Oxalates with a free end exhibited a plate-like shape at SEM and appeared acicular at TEM, due to the reduced thickness of ultrathin sections. Crystals that were embedded in tissues such as the sclera or degenerate detached retinal tissue formed either spherules or plates at SEM. No clear relationship with intracellular structures could be found at TEM, possibly due to postmortem autolysis phenomena. Calcium hydroxyapatite deposits appeared at SEM as fine granules distributed over the collagen fibers of the corneal and conjunctival stroma and the scleral lamellae, but were also present intracellularly, both in the nucleus and cytoplasm of epithelial cells.