江豚皮肤的超微结构及其与其它豚类的比较

江豚皮肤的超微结构与海洋豚类相同,但在各层表皮细胞中存在大量的膜被颗粒,这很可能与江豚适应从海水进入淡水的生活方式有关。大量成束的张力原纤维的存在,有利于江豚在水中深潜和快速游泳,可适应来自各方面的压力,加强细胞之间的联接。在上下颌皮肤的乳头层基部大量被囊神经末梢和有鞘神经纤维束的分布、与江豚水底觅食方式有关。白鱀豚和条纹原海豚皮肤的超微结构与江豚大致相同,但亦有其各自的特点。     

一种新的抗人角蛋白单克隆抗体

本文报道了一种新的抗人角蛋白单克隆抗体。用于免疫的抗原来自人足胼胝,传统的观念认为,此部位的角蛋白属于“软”角蛋白。然而我们在免疫荧光定位时发现,此单抗不能与一般上皮、表皮和培养表皮细胞的“软”角蛋白相反应,却能与哺乳动物的多种组织的“硬”角蛋白相反应。     

大鼠小肠5-HT免疫活性内分泌细胞的角蛋白免疫细胞化学定位

本文作者用免疫组化双色反应,对大鼠小肠5-HT免疫活性内分泌细胞进行表皮角蛋白免疫细胞化学定位。结果表明,5-HT免疫活性内分泌细胞含有表皮角蛋白阳性颗粒,提示胃肠的正常内分泌细胞和其它粘膜上皮细胞一样含有角蛋白中间丝,它们可能也和其它粘膜上皮细胸一样共同起源于内胚层。     

角蛋白酵解工艺研究进展

角蛋白是构成人和动物生皮表皮、毛皮毛囊的主要蛋白质,是结缔组织重要的结构蛋白。以畜禽副产物作为角蛋白开发的原材料,比较传统物理和化学方法与微生物发酵的优缺点,综述了微生物发酵角蛋白的优势菌株及现今的运用价值,旨在为今后研究角蛋白提取工艺和对其进行高附加值利用提供参考。     

恒河猴皮肤干细胞的体外培养纯化与鉴定

探索恒河猴皮肤干细胞的体外培养及纯化条件,为进一步的研究奠定基础. 通过组织块培养法和消化培养法 在体外培养恒河猴表皮细胞,然后用Ⅳ型胶原吸附法吸附20 min,获得快吸附细胞. 对快吸附细胞进行克隆培养,并进行免疫细胞化学双标染色、RT PCR鉴定 β1 整合素和角蛋白15的表达,用流式细胞仪鉴定纯化前后的细胞中 β1 整合素和角蛋白15的阳性细胞比例,并通过透射电镜观察细胞的超微结构. 组织块培养法和消化培养法均可获得表皮细胞,Ⅳ型胶原纯化后的细胞胞体较小,饱满,核/浆比例大,细胞镶嵌状排列. 细胞克隆分析显示,细胞全克隆生长率高. 细胞免疫荧光显示,分选后的细胞显示 β1 整合素和角蛋白15阳性. RT PCR检查呈现 β1 整合素和角蛋白15的特异性片段. 流式细胞仪检查显示,纯化前的细胞中角蛋白15阳性细胞占总细胞中的比例为8％, β1 整合素阳性细胞的比例为10.7％;纯化后,角蛋白15阳性细胞的比例为89.4％, β1 整合素阳性细胞的比例为88.5％. 通过组织块培养法和消化培养法均可培养获得活性良好的表皮细胞,Ⅳ型胶原吸附法是一种简便、有效的皮肤干细胞分离方法,可以为进一步的眼表上皮替代重建眼表提供足量的高纯度的干细胞建立可靠的物质基础.     

中等纤维在几种人体上皮细胞有丝分裂过程中的行为

本文用间接免疫荧光法和电镜术观察了分别来自人表皮(PcaSE-1)、复层上皮(CNE)和单层上皮(SPC-A-1)的3个上皮细胞系的细胞在有丝分裂过程中中等纤维的行为。结果表明,CNE细胞和SPC-A-1细胞表达两种不同类型的中等纤维系统:角蛋白纤维和波形纤维,而PcaSE-1细胞仅表达角蛋白纤维。当细胞进入有丝分裂时,PcaSE-1细胞的角蛋白纤维维持完整的形态且将有丝分裂纺锤体围绕在细胞中央。相反,在CNE细胞和SPC-A-1细胞中,在细胞有丝分裂时,角蛋白纤维解聚成无定形的胞质小体,然而它们的波形纤维始终保持完整的形态。我们认为(1)在分裂上皮细胞中,角蛋白纤维的解聚与细胞的恶性程度有关,而与间期上皮细胞中是否含有丰富的角蛋白纤维无明显关系。(2)在上皮细胞有丝分裂时,中等纤维可能参于纺锤体的定位和趋中。(3)在分裂CNE细胞中,波形纤维的可能功能是染色体的定位和定向。     

江豚和白鱀豚视网膜神经节细胞的研究

江豚和白暨豚视网膜神经节细胞根据其形态结构可分为1、2两型。其密度分布在大多数江豚和1头白(既鱼)豚呈两个高密度区。第一高密度区位于视网膜鼻侧偏腹方,第二高密度区位于颞侧偏背方。第一和第二高密度区的细胞的最高密度在江豚大多数分别为每平方毫米250和210左右,在一例白暨豚约180和140以上。其组成、密度分布及细胞总数在采自长江和黄海沿岸的江豚之间差异不显著。在白(既鱼)豚由于大神经节细胞相对增多,细胞平均直径比江豚的大;细胞数在40微米左右处形成特有的第二个峰;2型的细胞极少,且没有发现典型的星形神经节细胞。 几种豚类的视网膜神经节细胞的比较表明,在适应弱光环境的过程中,视网膜神经节细胞的组成发生了一些改变:2型的神经节细胞逐渐减少甚至消失;大神经节细胞相对增多;神经节细胞密度减小。视觉敏度提高,锐度下降。     

长江江豚基因组大小测定

本研究采用流式细胞术,以公鸡(Gallusdomesticus)红血细胞DNA含量为标准,测定了23头长江江豚(Neophocaenaphocaenoidesasiaeorientali)的基因组大小(或称C值)。实验过程中采用了保存在3中不同条件下的长江江豚的全血样品,用3种不同的方法提取白细胞。为了获得本实验所用的公鸡红血细胞DNA含量的准确值,首先以人(Homosapiens)的C值为标准,对其进行了校正。然后其C值(2C=2.35pg)用于长江江豚的基因组大小测定。结果发现:长江江豚的单倍体DNA含量为3.27pg/C,由此得出其基因组大小为3.17×109bp;雌性和雄性的C值分别为3.25pg和3.29pg,野外长江江豚和豢养长江江豚的C值分别为3.30pg和3.05pg。对雌雄个体之间以及不同生长条件下长江江豚的C值应用独立样本t检验分析,发现:1)不同性别的长江江豚基因组大小之间没有明显的差异;2)豢养条件下的长江江豚和野生长江江豚之间的基因组大小有明显差异,豢养条件下的长江江豚的基因组明显小于野生条件下的长江江豚。据此推测必要环境因子的变化可能会对长江江豚的基因组DNA含量造成影响。     

长江江豚细菌性疾病的诊治

人工饲养或易地保护长江江豚(Neophocaena asiaeorientalis asiaeorientalis), 其水体中常含有病原菌且易引起江豚发病, 探讨长江江豚的细菌性疾病诊疗方法十分必要。文章利用细菌的分离培养与鉴定, 结合血液检测结果, 对安庆西江围网内一头患病江豚进行了病原确诊, 结果发现患病江豚的致病原为金黄色葡萄球菌(Staphylococcus aureus)和魔氏摩根菌(Morganella morganii)。依据致病菌的药敏试验结果, 综合患病江豚的整体状况制定了治疗方案并对其进行系统治疗, 结果预后良好。研究的成功开展为江豚、海豚等鲸类动物细菌性疾病的诊断与防治提供了良好借鉴。     

江豚视网膜结构、神经节细胞计数及其分布特征

江豚(Neophocaena aslaecrientalis)是水生哺乳动物,其最大的特点是具有出色的回声定位能力,因此,对江豚的研究多集中于听觉方面。其视觉所起的作用不大被研究者注意,尤其对视觉系统的解剖学和组织学方面的研究尚未见过报导。本实验对江豚视网膜的神经节细胞进行了某些定量研究,同时还观察了其视网膜的一般组织结构,以分析其视网膜的发达程度。为了探索各种动物的视网膜在视觉信息加工中的作用,一些研究者如马图瑞那(Maturana),雅各布森(Jacobson),卡利尼那(Kalinina),范布伦(Van Buren),斯通(Stone)对青     

Lectins as Markers of Human Epidermal Cell Differentiation

The expression of sugar residues on human epidermal cells was investigated by means of lectin binding, as a way of determining membrane structural changes occurring during the differentiation of the epidermis. Fourteen lectins of different sugar specificity were conjugated with fluorescein isothiocyanate (FITC-lectins) and tested in fluorescence microscopy on frozen sections of normal human epidermis. In parallel, FITC-lectins were tested on psoriatic-involved epidermis to visualize differences in the expression of sugar residues that might occur during abnormal epidermal differentiation. No labelling could be obtained with lectins from Bandeira simplicifolia I, Dolichos biflorus, Limulus polyhemus, Tetragonolobus purpureas, Ulex europeus I , and Triticum vulgaris (group 1 lectins). A "pemphigus-like" intercellular labelling of the whole epidermis, except the stratum corneum, was obtained with lectins from Canavalia ensiformis, Maclura pomifera, Phaseolus vulgaris , and Ricinus communis I (group 2 lectins). A selective intercellular labelling of the stratum spinosum and the stratum granulosum was seen in normal epidermis with lectins from Arachis hypogaea, Glycine max, Helix pomatia , and Sophora japonica (group 3 lectins). In psoriatic epidermis, not only the basal cell layer, but also cells from the adjacent lower stratum spinosum were found to be negative, using FITC-lectins of group 3. These data indicate that the expression of lectin binding sites in normal epidermis differs according to the maturation of the cell from the basal cell to the more mature keratinocyte in the stratum granulosum. They suggest that lectins may be used as markers of epidermal cells in various stages of normal and abnormal differentiation.     

Gap junctions in the epidermis of fetal rats studied by transmission electron microscopy

In the ventral epidermis of fetal rats the size and distribution of intercellular gap junctions changed during differentiation. In the young fetus, between 13 and 17 days, large gap junctions sometimes exceeding 3 micron in profile length were found predominantly in basal cells. As the epidermis increased in thickness the mean profile length diminished until only small gap junctions were present mainly in more superficial layers even persisting into the stratum corneum. Endocytosis of the intercellular gap junctions gave rise to intracytoplasmic annular gap junctions (AGJs) which occurred after 17 days predominantly in the superficial three layers of the epidermis. The AGJs diminished in mean diameter with the age of the fetuses possibly as a consequence of the decreasing size of the intercellular gap junctions from which they had formed. Rarely sequestration of AGJs by cytoplasmic membranes occurred but many recognizable AGJs persisted into the stratum corneum. As in other developing systems, the function of gap junctions in epidermis is unknown but the extensive junctions of younger epidermis might be related to the maintenance of a greater level of uniformity both of mitotic activity and of differentiation.     

CELL JUNCTIONS IN AMPHIBIAN SKIN

Cell junctions have been investigated in the amphibian epidermis, a stratified squamous epithelium, and compared to those described previously in simple columnar epithelia of mammalian cavitary organs. In adult frogs and toads, and in larvae approaching metamorphosis, belts of membrane fusion or zonulae occludentes of considerable depth are regularly found between adjoining cells of the outermost layer of the stratum corneum, binding the cells together into a continuous, uninterrupted sheet. Another set of occluding zonules appears in the second cornified layer (when such a layer is present), and a third set usually occurs in the outermost layer of the stratum granulosum. Specialized elements described as "modified" and "composite" desmosomes are encountered along the lateral and basal aspects, respectively, of the cornified cells; ordinary desmosomes and maculae occludentes (i.e., spots of membrane fusion) are found in all other strata. The usual 200 A intercellular gap is generally maintained between the cells of the stratum germinativum at the basal ends of the intercellular spaces. Hence, the intercellular spaces of the epidermis form a largely continuous network, closed to the external medium and open to the dermal interstitia. The situation is comparable to that found in columnar epithelia, except that the intercellular spaces are much more extensive, and an extracellular subcompartment (or two) apparently exists in the stratum corneum and between the latter and the stratum granulosum. The last subcompartment is usually filled with a dense substance, probably derived from discharged secretory granules. The tripartite junctional complex characteristic of lumen-lining epithelia (i.e., a zonula occludens followed by a zonula adhaerens, and desmosome) is seen only in early larvae; in adults and in larvae approaching metamorphosis, the occluding zonule is followed directly by a series of modified desmosomes. Interpreted in the light of current physiological data, these findings suggest that the diffusion of water, ions, and small, water-soluble molecules is impeded along the intercellular spaces of the epidermis by zonulae occludentes while it is facilitated from cell to cell within the epidermis by zonulae and maculae occludentes.     

Avian epidermal differentiation: role of lipids in permeability barrier formation

Though avian skin is known to possess a highly lipogenic epidermis, little is known about its permeability barrier function. We correlated epidermal barrier function, fine structure and lipid biochemistry in the pigeon, Columbia livia, and compared these features with terrestrial mammalian systems. Whereas barrier function, as assessed by transepidermal water loss was not as efficient as in mammals, both groups shared certain morphological features including substantial compartmentalization of lipids in stratum corneum intercellular domains. Avian intercellular lipids derive from extrusion of intracellular non-membrane-bound droplets from lowermost corneocytes, rather than by secretion of lamellar discs from multigranular bodies, as previously reported in some avians, and in mammals. Instead, both the internal lamellae and the limiting membranes of multigranular bodies appear to degenerate, leading to the formation of non-membrane-bound droplets. The lipid content of avian epidermis and stratum corneum demonstrates important similarities to terrestrial mammals, i.e. abundant sphingolipids, a paucity of phospholipids, and abundant neutral lipids, but also certain striking differences, i.e. persistence of glycosphingolipids and triglycerides into the stratum corneum. Thus, avian stratum corneum forms a two-compartment system of lipid-depleted cells embedded in non-polar-lipid enriched intercellular domains, analogous to mammals. But, in contrast to mammals, the highly attenuated corneocytes of avians, which results from a paucity of keratin filaments, produce a 'straws-and-mortar' tissue, rather than the 'bricks-and-mortar' tissue of mammals.     

Fine structure of the epidermis of the mudskipper,Periophthalmus modestus (Gobiidae)

The ultra-structure of the epidermis of the mudskipper,Periophthalmus modestus, was examined by both light and transmission electron microscopies. The epidermis is exceptionally not well endowed with mucous or granular cells. Filament-containing cells occur in three distinct layers of the surface, middle and basal epidermis. The surface layer is further subdivided into two layers, an outermost and less superficial one. Two different cell types were identified in the epidermis. Type I cells are fiat cells in a single stratum. Type II cells are enormous cells, characterized by having a large vacuole in the cytoplasm. The outermost layer is composed of a free surface of Type I cells and numerous microridges covered with a fuzzy, fibrillar substance. The “fuzz” forms a cuticule-like structure, but keratinization as found in terrestrial animals does not occur. The superficial layer contains Type I cells and intraepithelial blood capillaries. When Type I cells become senescent, numerous intercellular spaces are formed in the plasma membranes of adjacent cells, with the senescent cells finally falling off. Just beneath these cells, however, young cells of Type I are always found. The blood capillaries are usually reinforced with young Type I cells. A large volume of oxygen may be absorbed through the skin using the blood capillary network. The middle layer contains several strata of Type II cells. The special corky structure of these cells seems to play an important role in thermal insulation and protection against ultraviolet light in relation to life out of water. However, by comparison with terrestrial animals, the histological design of the epidermis of this goby appears incomplete, so as to reduce desiccation on land, owing to the epidermis lacking a keratinized stratum. The differentiation of the epidermis seems to be an adaptation for a terrestrial habit in this species.     

Avian permeability barrier function reflects mode of sequestration and organization of stratum corneum lipids: reevaluation utilizing ruthenium tetroxide staining and lipase cytochemistry.

The epidermis of avians and terrestrial mammals has evolved distinct, but related mechanisms to survive in a terrestrial environment. In both phyla, stratum corneum lipids form the basis of the cutaneous permeability barrier, but barrier function is less efficient in avians. Whereas in mammals the epidermal lamellar body (LB) secretes its contents into the intercellular spaces, in the feathered epidermis of avians, its distinctive secretory organelle, the multigranular body (MGB), does not secrete its contents into the stratum corneum intercellular spaces. Yet, neutral lipid-enriched droplets, derived from the cytosolic breakdown of MGB, ultimately are squeezed through membrane pores into the stratum corneum interstices. In this study we determined: a) using ruthenium tetroxide (RuO4) fixation, whether these droplets form membrane structures after deposition in the stratum corneum interstices; and b) the similarities and differences between avian MGB and mammalian LB, using enzyme cytochemistry as a marker for secretion, and optical diffraction computer-aided image analysis and reconstruction to compare the internal structure of MGB vs. LB. MGB were shown to possess a similar lamellar substructure to LB in RuO4-fixed specimens, exhibiting comparable dimensions on optical diffraction and computer transform analysis. Moreover, the intercellular lipids of avian stratum corneum lacked membrane-substructure, as was present in parallel samples of mammalian stratum corneum. Thus, both the absence of MGB secretion, and the failure of intercellular lipids to form membrane bilayers may explain the inherent differences in barrier function in these two taxa.     

The permeability barrier in mammalian epidermis

The structural basis of the permeability barrier in mammalian epidermis was examined by tracer and freeze-fracture techniques. Water-soluble tracers (horesradish peroxidase, lanthanum, ferritin) were injected into neonatal mice or into isolated upper epidermal sheets obtained with staphylococcal exfoliatin. Tracers percolated through the intercellular spaces to the upper stratum granulosum, where further egress was impeded by extruded contents of lamellar bodies. The lamellar contents initially remain segregated in pockets, then fuse to form broad sheets which fill intercellular regions of the stratum corneum, obscuring the outer leaflet of the plasma membrane. These striated intercellular regions are interrupted by periodic bulbous dilatations. When adequately preserved, the interstices of the stratum corneum are wider, by a factor of 5-10 times that previously appreciated. Freeze-fracture replicas of granular cell membranes revealed desmosomes, sparse plasma membrane particles, and accumulating intercellular lamellae, but no tight junctions. Fractured stratum corneum displayed large, smooth, multilaminated fracture faces. By freeze-substitution, proof was obtained that the fracture plane had diverted from the usual intramembranous route in the stratum granulosum to the intercellular space in the stratum corneum. We conclude that: (a) the primary barrier to water loss is formed in the stratum granulosum and is subserved by intercellular deposition of lamellar bodies, rather than occluding zonules; (b) a novel, intercellular freeze-fracture plane occurs within the stratum corneum; (c) intercellular regions of the stratum corneum comprise an expanded, structurally complex, presumably lipid-rich region which may play an important role in percutaneous transport.     

The permeability barrier in the epidermis of the grass snake during the resting stage of the sloughing cycle

Summary Tracer and freeze-fracture replication techniques show that there are two morphologically and topographically distinct permeability barriers in the epidermis of the grass snake. Tight junctions interconnect the apico-lateral plasma membranes of the uppermost living cells, establishing an ionic or osmotic gradient between the stratum germinativum and alpha layer. The second barrier is formed by intercellular lipid sheets in the overlying mesos layer, which are very similar to the barrier found in the stratum corneum of mammals.     

The effect of the conditions for connective tissue formation during posttraumatic skin regeneration in rats on the adhesive properties of the epidermal cells]

A cicatrix formed in the process of posttraumatic skin regeneration is characterized by a higher cell adhesion power in the upper, and, especially, in the middle epidermis stratum. The cell adhesion power indices in these strata, and cell mitotic activity of basal epidermis stratum near the cicatrix depend on conditions of connective tissue formation in the wound defect. The effect of physiological solution and trypsin on the wound process results in a moderate rising of intercellular contact strength and in decreasing in the number of dividing basal stratum cells, while addition of ronidase solution results in a sharp rising of the corneous scale adhesion strength, and in establishing the straight correlation between this index and the speed of epidermocyte production.     

Effect of a sake concentrate on the epidermis of aged mice and confirmation of ethyl alpha-D-glucoside as its active component

Generations of Japanese have appreciated the positive effects that sake can have on skin conditions, and studies have shown that concentrated sake suppressed the epidermal barrier disruption caused by ultraviolet B (UVB) irradiation. We investigated the effect of a topical application of a sake concentrate on the murine epidermis and found that the intercellular lipid content in an aged epidermis was significantly increased. Furthermore, the topical application of ethyl alpha-D-glucoside (alpha-EG), a component of sake, brought about a similar improvement in the levels of intercellular lipids. Following on from this, we confirmed that alpha-EG also significantly increased the content of loricrin protein, an indicator of successful corneocyte differentiation, while reducing the number of corneocyte layers in the aged stratum corneum. These results confirmed alpha-EG as the primary active component of the sake concentrate that had a positive effect on the epidermis. alpha-EG increased the intercellular lipid content, accelerated the differentiation of corneocytes, and reduced the thickness, thus improving the functions of the stratum corneum.