扬子鳄胚胎舌表面的扫描电镜观察

在扫描电镜下观察了孵化第３６ｄ至第６２ｄ孵出的扬子鳄（Ａｌｌｉｇａｔｏｒｓｉｎｅｎｓｉｓ）胚胎舌表面的形态变化过程。舌表面于孵化第３８ｄ形成少数大的隆起与凹陷，第４刚开始出现舌乳头。舌上皮细胞的表面在第３６～４２ｄ为圆形，表面光滑，中央凹陷，以后逐渐变成扁平细胞，第５２ｄ细胞呈规则的多边形，表面微绒毛清晰，细胞中央有一向外隆起的圆形或卵圆形核区，第５６ｄ后老化的舌上皮出现脱落现象。孵化第４２ｄ舌后部及中部的上皮内陷形成较大的舌腺腺孔。第４８～５６ｄ中，较小的舌腺孔显著增多，而大舌腺孔数目无明显增加。第６２ｄ多数大舌腺孔内可见有粘液样分泌物。舌表面味蕾的形成很迟，第５６ｄ才出现Ⅰ、Ⅱ、Ⅲ型发育中的味蕾，第６２ｄ形成部分成熟的味蕾。本文对扬子鳄舌腺及味蕾的形态发生特点作了讨论。     

扬子鳄眼球的胚胎发生

在２４例扬子鳄胚胎中，观察了眼球的发生及其组织分化过程。孵化后第２ｄ，视泡已从前脑突出形成，第６ｄ形成双层视杯和晶状体泡。晶状体纤维先由晶状体泡后壁上皮生成，然后由赤道部的泡壁上皮生成。虹膜、角膜内皮和基质均由视杯周围的间充质迁入形成。视网膜的色素上皮层最先分化。神经上皮在第１６ｄ出现节细胞的内迁。第１８ｄ可辨认节细胞层和神经纤维层。第２４ｄ可辨认内网层。第３０ｄ开始出现外核层与内核层的分化。第３     

人胚胎食管上皮的扫描电镜观察

了解人胚胎食管上皮的组织发生。方法电镜和光镜观察。结果７周的食管上皮为复层柱状,有２－３层细胞。表层柱状细胞有稀疏的微绒毛,少数具有纤毛１２－１７周时由３－６层细胞组成,表面多为柱状毛细胞,柱状的无纤毛细胞开始变矮。     

人胎副睾与输精管的组织学观察

取16－28周24例布依族人胎副睾及输精管，HE，PAS染色，示16周副睾上皮呈假复层柱状，胞质含较多粗大PAS阳性颗粒，游离面有纤毛，上皮基膜呈PAS阳性反应，随着胎龄增加，管腔增大，上皮变高，28周副睾管腔平整，上皮外有环行平滑肌，睾丸输出管呈明显不规则形，16周时输精管上皮呈单层柱状，肌层不明显，19周上皮已呈假复层柱状，未见纤毛，随着胎龄增加纤毛出现，环行肌层次增加后纵行肌出现，上皮基膜，纤毛呈PAS阳性反应，为研究人胎生长发育，提供形态学基础。     

慢性支气管炎病人支气管粘膜的分泌型IgA

分泌型IgA(SIgA)具有明显的抗病毒、抗菌和抗毒素活性,阻止细菌向粘膜表面粘着,使侵犯粘膜的毒素失去毒力,是局部免疫的第一道防线。慢性支气管炎长期迁延,支气管粘膜的假复层柱状上皮改造为复层扁平上皮,丧失合成SIgA 的能力。作者研究慢性支气管炎时支气管粘膜SIgA 的变化,检查30例病人,年龄20～60岁,从右肺中叶支气管取活检材料,制半薄切片,用直接和间接免疫组织化学反应检查SIgA 定位。慢性炎症时支气管上皮发生改造,起初为过度分泌期,杯状细胞增多。随着炎症加     

气管内注入脂多糖法建立大鼠慢性支气管炎模型

摸索建立大鼠慢性支气管炎（慢支）模型的新方法。用气管内注入脂多糖（ＬＰＳ）法建立大鼠慢支模型,观察光镜及电镜下电气管、支气管及肺组织病理学改变。气管及支气管上皮脱落,杯状细胞增生,粘液腺增生肥大,气管支气管壁见慢性炎细胞浸润,管壁增厚,管腔充满粘液及大量以中性粒细胞为主的炎细胞,支气管平滑肌增生肥厚,肺气肿形成,电镜下气管支气管纤柱状上皮细胞变性数量减少、复合纤毛形成;ＢＡＬＦ白细胞总数及中性粒细     

人胚胎气管壁组织发生的研究

目的：了解气管壁的组织发生及探讨婴幼儿呼吸道疾病的相关因素。方法：应用ＨＥ及ＰＡＳ反应,光镜观察。结果：８周的胚胎,气管壁由２－３层复层柱状上皮细胞及外周的间充质构成,上皮细胞的ＰＡＳ反应为阳性。     

人胚胎海马发育的形态学研究 Ⅴ.室管膜的发生

运用HE和Nissl染色、免疫组织化学法、透射电镜及扫描电镜，对60例6周至足月的人胚胎海马室管膜上皮变化进行了观察。发现胚胎发育过程中室管膜发生了剧烈变化。最早室管层神经上皮细胞为假复层柱状，随着未分化细胞向外迁徙，海马室管膜层神经上皮细胞迅速增殖，形成复层上皮。当室管膜层细胞停止迁徙时，室管膜开始向假复层柱状及单层柱状上皮转变。电镜观察，胚胎早期神经上皮细胞由未分化细胞构成；其特点是，细胞质内各种特化细胞器匮乏，但糖原丰富。15周左右未分化细胞开始向长突细胞及室管膜细胞分化。长突细胞电子密度高，底部有细长突起，表面有微绒毛，胞质内微丝丰富；而室管膜细胞电子密度低，底部无突起，但表面有丰富的纤毛。对长突细胞及免疫组化染色的GFAP阳性细胞进行形态和发育特征的比较，提示两者属同一类细胞。扫描电镜下，15周前室管膜表面微绒毛较多，以后纤毛逐步发育，大量密集纤毛布满于室管膜表面。此外，还能见到一类接触脑脊液神经元，这类神经元可为多极或双极，并有突起伸入室管膜上皮内。     

不同时期胎儿食管上皮的观察

<正> 本文用18例2—10个月胎儿食管分为6段,对食管上皮作光镜及透射电镜观察,并对复层上皮表层的柱状纤毛细胞的纤毛用凝集素标记进行观察。结果:1.胚胎时期食管上皮发育过程中有三度改变,初期为单层柱状上皮,10至12周左右开始分化成2至3层细胞的复层上皮,以后随月令增长复     

硅橡胶管对犬气管创面愈合的影响

本实验剥离并切去了12只犬气管一小块粘膜,其中8只犬术后在气管内放置了硅橡胶管为实验组,4只犬未放作为对照组。通过普通光镜和扫描电镜,观察了该管对气管创面及对正常粘膜的影响。发现:1.放管后,创面愈合过程正常,唯速度明显减慢;取管后,创面上完全恢复了正常的气管上皮。2.20×5mm之创面放管42天,鳞状上皮完全覆盖了创面,取管后28天,该上皮转变为纤毛柱状上皮。3.放管后,正常的气管上皮仍为假复层柱状细胞,但其表面之纤毛全部消失,取管后,纤毛可完全恢复。4.硅橡胶是比较理想的支撑喉气管的材料。     

离体金黄地鼠气管器官培养的实验形态学研究

本文报告正常状态下金黄地鼠的体外器官培养变化。应用旋转培养方法,培养液用RPMI 1640及Eagle MEM,不论是否加小牛血清,培养的气管组织均可存活到8周。组织学及超微结构观察表明,培养1～4周内的气管上皮,保持着复层或单层柱状上皮结构,表面尚见纤毛,上皮细胞还没有明显的胞浆变性。细胞器如粗面内质网及线粒体等,还未见破坏。表层上皮细胞间的连接,也是常态的紧密连接。培养5周时,上皮表面大部分纤毛脱落,表层上皮细胞核变扁平、横位。7周以后,细胞结构出现退行性变化。放射自显影观察表明,上皮细胞核内仍有明显的~3HTdR掺入。本文认为,在一般条件下培养4周以内,气管上皮的超微结构较为完整,此时附加实验因素,开展实验病理研究是比较合适的。基础培养液Eagle MEM具有与RPMI 1640培养液相同的培养效果,无论从防止细胞增生引起培养组织的消耗,还是从经济观点考虑,在器官培养中使用基础培养液是值得推荐的。     

The postnatal development of the respiratory system of the opossum. I. Light and scanning electron microscopy

The postnatal development of the respiratory system in the opossum has been traced, using 102 specimens divided into 11 groups according to snout-rump length. At birth, the lung is markedly underdeveloped and is represented by a pumitive system of branching airways that end in a number of terminal chambers or sacs. The airways, constituting the conducting portion of the lung, are lined by columnar epithelium that is devoid of cilia and goblet cells. The terminal air chambers contain an extensive capillary bed and are surfaced by squamous epithelium interspersed with scattered cuboidal cells. By the 3 cm stage, bands of smooth muscle have differentiated in relation to the bronchial epithelium and scattered cilia are present in the epithelium of the trachea and bronchi. Air chambers immediately adjecent to established bronchi differentiate further and become incorporated into the bronchial tree and new air chambers develop at the most distal extent of the bronchial system up to the 15.5 cm stage. Numerous spaces lined by squamous epithelium, which represent the first appearance of the arbor alveolaris, appear within the cellular stroma of the lung of the 7 cm opossum. By the 20 cm (juvenile) stage, mature alveoli, containing many vacuolated cells, are present and a thick collagenous lamina has developed between the pleura and the lung parenchyma.     

Histopathology of the airway epithelium in an experimental dual-phase model of bronchial asthma

BACKGROUND: Lesions of trachea cuticles are a pathological histological characteristic of bronchial asthma. Furthermore, collected tracheal cuticles desquamated from the respiratory tract are found in patients' sputum when asthma attacks occur or after the induction of allergen inhalation. From these facts, it is assumed that desquamation of trachea cuticle cells is a pathological symptom of bronchial asthma. However, there has not been any chronological report of desquamation of trachea cuticles through the process of bronchial asthma attacks. OBJECTIVE: For this report, we made an experimental bronchial asthma model using guinea pigs, and conducted chronological examinations of trachea cuticle lesions related to pathological symptoms of bronchial asthma using a transmission electron microscope and a scanning electron microscope. METHODS: The experimental asthma models were made by injection of ovalbumin into the abdominal cavity of guinea pigs. Then the airway responses to inhaled aerosolized ovalbumin were induced. The trachea were enucleated and examined under an optical microscope, a transmission electron microscope (hereafter abbreviated as TEM), and a scanning electron microscope (hereafter abbreviated as SEM) after 1, 2, 4, 8, 12, 24 h and 7 days after the immediate airway responses. RESULTS: Intercellular oedema of ciliated epithelium was observed in the sensitization groups immediately after the immediate airway response. SEM observation revealed increased mucus secretion and shortening of cilium. A slight case of desquamation or deciduation of ciliated epithelium was also beginning to appear. TEM observation revealed a dilation of ciliated epithelium intervals. Infiltration of eosinophilic leucocytes was already detectable beneath the ciliated epithelium. The degree of ciliated epithelium desquamation and infiltration of eosinophilic leucocytes progressed with time. When the late airway response occurred 4 hours later, eosinophilic leucocytes had increased drastically, and ciliate epithelium had desquamated to the extent that basal cells were exposed. Seven days after the immediate airway response, epithelium intercellular oedema had improved, and cilium had been reproduced. CONCLUSION: These results suggest that desquamation of epithelium caused by trachea cuticle lesions appears at an early stage of an asthma attack, owing to the contraction of the trachea, and that the damage is intensified by the infiltration of eosinophilic leucocytes.     

Development of hamster tracheal epithelium: I. A quantitative morphologic study in the fetus

The development of the tracheal epithelium was studied in hamsters, beginning on fetal day 10 and ending on fetal day 16, shortly after birth. The epithelial morphology was characterized and as soon as the cells could be recognized by type (day 14) their proportions were quantified along dorsal and ventral surfaces from larynx to carina. At all times, columnar cells of the dorsal surface were taller than those of the ventral surface. On days 10 and 11 the simple epithelium was composed of poorly differentiated columnar cells, but on day 12 organoid clusters, consistent with the morphology of neuroepithelial bodies, were observed; four clusters were seen along the dorsal epithelium in one section. The epithelium was pseudostratified on day 13, composed of short and columnar cells. Most columnar cells were poorly differentiated but a few preciliated and ciliated cells were recognizable dorsally, especially at the tracheal poles. Hemidesmosomes were seen at the base of some short cells on day 14, and rough endoplasmic reticulum was moderately developed in some columnar cells, suggesting that these cells were prebasal and presecretory cells, respectively. Preciliated and ciliated cells, which were most prevalent caudally, accounted for about 14% of all dorsal epithelial cells on day 14, but they were rare in the ventral surface, about 0.1%. The epithelial cells were sufficiently specialized by days 15 and 16 to allow quantification by type. Proportions of basal, presecretory, and preciliated-ciliated cells were similar on both days but the cellular makeup of dorsal and ventral surfaces was significantly different. There were more basal cells ventrally (36-40%) than dorsally (22-23%), and more preciliated-ciliated cells dorsally (18-21%) than ventrally (about 1%). On days 15 and 16 differences also existed along both surfaces between cranial and caudal parts of the trachea. Basal cells were more prevalent cranially and preciliated-ciliated cells were more prevalent caudally.     

Development of hamster tracheal epithelium: II. Cell proliferation in the fetus

Proliferation of epithelial cells in the fetal trachea was studied in hamsters, beginning on the 10th gestational day and ending on the 16th day, shortly after birth. The mean mitotic index (MI) was highest on day 10, with no statistical confirmation of a change between days 10 and 11. The MI fell to about 2% on days 12 and 13, and declined thereafter to about 0.3% on day 16. The MIs for dorsal and ventral surfaces were compared and values were similar except on day 10, when ventral exceeded dorsal, and on day 12, when dorsal exceeded ventral, 2.56% and 1.3%, respectively. On days 10, 11, and 12 the epithelium was simple, composed of poorly differentiated columnar cells that proliferated. On day 13 the epithelium was pseudostratified owing to the presence of a few short cells that did not reach to the lumen. Throughout the fetal period, proliferation of columnar cells predominated but division of short (basal) cells increased from 8% to 40% of the total mitotic activity between day 13 and day 15. Proliferation of basal cells then declined, so that on day 16, 84% of all cells in mitosis were columnar. If basal cells divide to make more of themselves they must proliferate rapidly between day 13 and day 15, because they were virtually absent on day 12 but accounted for about 36% of the ventral and 23% of the dorsal epithelial cells on day 16. Based on the results, a hypothetical model is proposed for the formation of pseudostratified mucociliary epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microanatomy of the major airway mucosa of the bowhead whale, Balaena mysticetus

In the bowhead whale, Balaena mysticetus, the mucosa of the major airways from the blowholes through the rostral portion of the larynx is lined with parakeratotic, pigmented, stratified squamous epithelium. Scattered enlarged connective tissue papillae of the lamina propria of the nasal vestibules and the palatopharyngeal sphincter contain encapsulated nerve endings. Abundant papillae in the mucosa covering the epiglottic and arytenoid cartilages contain similar nerve endings. The remainder of the laryngeal cavity and laryngeal sac is lined by a variably pigmented, stratified squamous epithelium, which is not keratinized. At the laryngotracheal junction the lining changes to ciliated pseudostratified columnar epithelium which continues through the trachea and principal bronchi. Scanning electron microscopy (SEM) indicates that this epithelium is typically mammalian, with approximately half of the surface cells bearing cilia and slender microvilli. The remaining cells are mucus producing and have thicker microvilli. The valvular mass regulating the external nares consists of irregular, dense white fibrous connective tissue with numerous adipose cells and is penetrated by skeletal muscle cords ranging from 2-4 mm in diameter. The septal mass between the blowholes is composed of irregular, dense white fibrous connective tissue containing large tendinous bundles, clusters of adipose cells, and several large arteries and thick-walled veins. The lamina propria of the nasal vestibules is irregular, dense white fibrous connective tissue. That of the larynx is not as dense and contains proportionately more elastic fibers. The laryngeal sac does not contain elastic laminae, but does have a tunica muscularis of skeletal muscle bundles. Within the trachea and principal bronchi, the lamina propria possesses laminae of longitudinally oriented elastic fibers and simple, branched tubuloalveolar mucous glands. The nasal, laryngeal, tracheal, and bronchial cartilages are hyaline with vascular channels.     

Differential distribution of brush cells in the rat lung

The distribution of brush cells in the rat lung was studied using electron microscopic morphometry. Samples were taken from six distinctive anatomical regions. Tissue from the trachea, lobar bronchi, terminal bronchioles, first alveolar duct bifurcations, proximal alveolar regions, and the distal alveolar region were isolated and embedded in Epox 812. Aside from the trachea and the lobar bronchi, the other four regions were isolated from embedded tissue using microdissection techniques. Electron micrographs taken from thin sections of these samples were analyzed. It was found that brush cells made up 10% of the volume of epithelium covering the first alveolar duct bifurcation. Approximately 2% of the proximal alveolar epithelium, 1.4% of the terminal bronchiolar epithelium, and 3% of the tracheal epithelium were made up of brush cells. No brush-bordered epithelium was found in the lobar bronchi or in the distal alveolar walls. We conclude that brush cells have a distinct spatial location in the lung, being in high concentration in the trachea and in areas where first generation alveolar ducts bifurcate. The highest density was on the bifurcation of the first alveolar ducts, and their density decreased radially from this region.     

Basal cells in human bronchial epithelium

The morphology and distribution of basal cells were investigated in adult human bronchial epithelium. In both smokers and non-smokers typical basal cells were more numerous than atypical basal cells, which were distinguished by their spindle-shaped nucleus, polar cytoplasm, and processes that extended along the basal lamina. The nucleus of the atypical basal cell was consistently closer to the muco-ciliary surface than was the nucleus of the typical basal cell. In cross-sections of bronchi the numbers of typical basal cells/mm epithelium were greatest in large airways; in smaller bronchi (i.e., generations 7–16) the frequency declined. The numbers of atypical basal cells/mm epithelium were similar throughout the bronchial tree. Throughout the bronchial tree both types of basal cells contributed to the maintenance of epithelial cohesion by providing desmosomal attachment for columnar cells. The importance of typical basal cells in this role was indicated by their greater numbers, which collectively presented a large surface for epithelial cell attachment by desmosomes. The surface presented by the cell body and processes of each atypical basal cell for attachment of columnar cells by desmosomes was extensive. If the basal cell is the most important progenitor of bronchial epithelium and the cell at risk in the development of lung cancer, the presence of more basal cells in upper airways, where many lung cancers originate, may be significant. The basal cell populations in larger bronchi are perhaps the greatest concentration of cells with proliferative capability and potential for neoplastic transformation in the human bronchial tree. © 1994 Wiley-Liss, Inc.