SD大鼠皮肤组织病理学观察

目的观察不同日龄SD大鼠皮肤组织学结构。方法10％甲醛固定,行石蜡切片,HE染色。结果新生大鼠皮肤较薄,透明层缺乏,皮脂腺发育良好。6月龄时表皮、真皮和皮下组织明显增厚,毛囊增粗,生长旺盛,毛囊深入皮下脂肪层。24月龄时,大鼠皮脂腺及汗腺萎缩,表皮变薄,真皮成纤维细胞、血管数量减少,弹力纤维变细。结论不同日龄SD大鼠皮肤组织学结构有差异。     

金佛拟小鲵幼体皮肤的显微结构观察

采用光镜和扫描电镜对金佛拟小鲵(Pseudohynobius jinfo)幼体皮肤进行组织学和形态学观察。金佛拟小鲵幼体皮肤由表皮和真皮构成。不同部位皮肤厚度不同,头部背侧皮肤最薄,其厚度为(45.99±12.77)μm,尾部腹侧的皮肤最厚,其厚度为(95.21±42.72)μm。表皮角质层仅躯干背部和尾部明显,由仍具有一定生理活性的复层扁平上皮细胞构成。皮肤腺体包括黏液腺和颗粒腺。黏液腺广泛分布于身体各个部位的皮肤,颗粒腺呈区域性分布,仅见躯干部和尾部皮肤,其体积大于黏液腺。毛细血管多分布于真皮疏松层腺体周围,与表皮层紧密接触并凸向表皮。色素细胞主要分布于表皮和疏松层的交界处,呈多细胞聚集的状态,形成厚度不一的色素层。     

角蛋白15在大鼠皮肤发育中表达的研究

目的研究角蛋白15(K15)在大鼠皮肤发育中的表达状况,定位表皮干细胞.方法以不同年龄大鼠背部皮肤为标本,用组织学方法,观察出生后大鼠皮肤的形态发育变化;以K15单克隆抗体为一抗,进行免疫组织化学染色,观察K15在大鼠皮肤中的表达状况.结果(1)组织学方法显示,随着年龄的增长,大鼠背部表皮细胞层数逐渐变少;在毛囊的生长周期中,以隆突区为界,毛囊上段为恒定区,下段呈周期性变化(2)免疫组化染色显示,毛囊隆突区细胞胞浆表达K15,随年龄的增长,K15阳性细胞出现在毛母质细胞区、毛囊外根鞘和表皮基底层.结论表皮干细胞位于毛囊隆突区,与表皮的更新和毛囊的周期性变化有关.     

龟足白垩腺的组织学和超微结构

应用光学显微镜和透射电子显微镜对龟足(Capitulum mitella)白垩腺的组织学和超微结构进行观察。龟足的白垩腺由腺细胞和管道系统组成,外周覆有一层结缔组织膜。腺细胞为单细胞,其发育与个体发育不同步。年幼腺细胞较小,形态为圆形或椭圆形,细胞核也为圆形或椭圆形。随着腺细胞的发育,细胞及细胞核逐渐变大,形状不规则具多态性。成熟腺细胞的细胞质电子密度高,充满大量粗面内质网和游离核糖体;线粒体很丰富,但未见高尔基体。细胞质中含有丰富的颗粒状物质以及大小不一的囊泡,小囊泡的聚集和融合形成了大囊泡即胞内管。管道系统根据位置和功能分为4个层次:胞内管、收集管、次级管和初级管。收集管、次级管和初级管的管壁均由单层上皮细胞组成,初级管较收集管和次级管大且内腔衬有几丁质层。收集管的管壁上皮细胞与腺细胞之间形成隔状连接,各级管壁上皮细胞之间也形成隔状连接,这种结构保证了管道的紧密性。总之,龟足白垩腺的形态结构类似于茗荷(Lepas anatifera)和Dosima fascicularis。     

松江鲈鱼皮肤的显微和亚显微结构

采用光学显微镜、扫描电镜和透射电镜,对松江鲈鱼(Trachidermus fasciatus)成体皮肤的显微和亚显微结构进行了观察。结果表明,松江鲈鱼体表不同部位皮肤的厚薄不一,但基本结构相似。皮肤由表皮和真皮层构成。松江鲈鱼的皮肤裸露无鳞,表皮层较薄,由约4～8层细胞构成,主要由复层上皮细胞和黏液细胞及基底细胞组成。表层细胞呈扁平、多边形,细胞之间主要靠桥粒紧密连接,连接处形成增厚的边缘嵴状突起。表皮细胞游离面向内凹陷,表面形成指纹状微嵴。黏液细胞呈圆形或卵圆形,散布在上皮细胞之间。黏液细胞内的黏原颗粒具有椭圆颗粒状、均匀致密的块状和疏松丝状3种不同形态。真皮通过基膜与表皮相连,由稀疏层和致密层构成。真皮结缔组织在腹部较厚而在其他部位较薄。表皮与真皮连接处有色素层,头部、背部、尾柄和体侧皮肤色素细胞分布多,色素层明显,而腹部和颏部皮肤缺少色素。松江鲈鱼黄河群体真皮层中有角质棘状突起,而滦河群体则无。头部、体侧和尾柄处皮肤上还分布有侧线孔和表面神经丘等感觉器官。     

松江鲈鱼皮肤的显微和亚显微结构观察

采用光学显微镜、扫描电镜和透射电镜,对松江鲈鱼（Trachidermus fasciatus）成体皮肤的显微结构和亚显微结构进行了观察。结果表明,松江鲈鱼体表不同部位皮肤的厚薄不一,但基本结构相似。皮肤由表皮和真皮层构成。松江鲈鱼的皮肤裸露无鳞,表皮层较薄,由约4～8层细胞构成,主要由复层上皮细胞和黏液细胞及基底细胞组成。表层细胞呈扁平、多边形, 细胞之间主要靠桥粒紧密连接,连接处形成增厚的边缘嵴状突起。表皮细胞游离面向内凹陷,表面形成指纹状微嵴。黏液细胞呈圆形或卵圆形,散布在上皮细胞之间。黏液细胞内的黏原颗粒具有椭圆颗粒状、均匀致密的块状和疏松丝状3种不同形态。真皮通过基膜与表皮相连,由稀疏层和致密层构成。真皮结缔组织在腹部较厚而在其他部位较薄。表皮与真皮连接处有色素层,头部、背部、尾柄和体侧皮肤色素细胞分布多,色素层明显,而腹部和颏部皮肤缺少色素。松江鲈鱼黄河群体真皮层中有角质棘状突起,而滦河群体则无。头部、体侧和尾柄处皮肤上还分布有侧线孔和表面神经丘等感觉器官。     

略谈触觉

略谈触觉陈英水（福建省松溪一中，３５３５００）有人把轻压称触，重触称压，认为两者性质一样，统称触觉。多数学者认为，触觉和压觉的感受器是不同的。触觉感受器是触觉小体（分布于真皮浅部的乳头层）和皮肤部围绕毛囊的神经末梢。压觉感受器是环层小体（分布于真皮深...     

大鼠眼球和泪腺中睫状神经营养因子及其受体的组织定位

目的观察睫状神经营养因子(CNTF)及其受体CNTFRα在大鼠眼球、泪腺上的分布情况.方法取雄性SD大鼠两侧眼球和泪腺,作石蜡切片,用免疫组织化学ABC法染色检测眼球、泪腺中CNTF和CNTFRα的免疫阳性反应.结果 CNTF和CNTFRα的免疫阳性反应产物在眼球和泪腺的组织定位基本相同,包括角膜上皮细胞、固有层神经纤维、角膜细胞、内皮细胞,虹膜上皮细胞,睫状体上皮细胞,晶状体上皮,视网膜色素上皮细胞、苗勒细胞、节细胞层细胞,球结膜上皮细胞,泪腺腺细胞及导管上皮.结论 CNTF及其受体选择性地分布于眼球和泪腺的一些细胞中,且多数细胞与房水和泪液的产生和接触有关.     

版纳鱼螈幼体和成体皮肤的结构

采用光镜和扫描电镜,对我国特有的珍稀濒危两栖动物版纳鱼螈Ichthyophis bannanicus幼体和成体的皮肤进行形态学和组织学观察.版纳鱼螈幼体和成体的皮肤均可分为表皮、真皮疏松层和真皮致密层;皮肤中含有粘液腺和颗粒腺;在不同发育阶段或同一个体的不同部位,其皮肤的各种组成成分在结构和厚度上存在着差异:成体和幼体都是头部的表皮最厚,尾部的最薄;幼体表皮各层细胞分化不明显,几无角化现象,成体表皮的各层细胞分化明显,表层细胞明显角化;成体躯干部皮肤最厚,头部最薄,幼体则是头部皮肤最厚,尾部最薄;幼体和成体的头部皮肤都分布有大量的粘液腺,颗粒腺分布较少;幼体的躯干部皮肤则主要分布着大量颗粒腺,尾部只有颗粒腺,未见粘液腺;成体躯干部和尾部皮肤均分布有大量的颗粒腺和粘液腺.     

豫医无毛小鼠皮肤透射电镜观察

采用透射电镜技术对12～28日龄豫医无毛小鼠(YYHL)背部皮肤超微结构进行了观察.结果 发现:12日龄时,无毛小鼠皮肤毛囊上皮细胞簇集成团,占据毛球的位置;14日龄时,毛囊上皮细胞出现不同程度的凋亡形态学改变,核染色质凝聚呈"新月形"或形成圆形或椭圆形的凋亡小体;18日龄时,毛囊上皮细胞胞核部分区域退变形成大小不一的类似脂滴的空泡;21日龄时,毛囊上皮细胞退变消失,角化成纤维样的物质;到28日龄时,毛囊上皮细胞完全退变成空洞样结构.由此推断,无毛基因的突变诱发了豫医无毛小鼠皮肤毛囊上皮细胞的凋亡,从而引起小鼠的脱发.     

Localization of sex steroid receptors in human skin

Sex steroid hormones are involved in regulation of skin development and functions as well as in some skin pathological events. To determine the sites of action of estrogens, androgens and progestins, studies have been performed during the recent years to accurately localize receptors for each steroid hormone in human skin. Androgen receptors (AR) have been localized in most keratinocytes in epidermis. In the dermis, AR was detected in about 10% of fibroblasts. In sebaceous glands, AR was observed in both basal cells and sebocytes. In hair follicles, AR expression was restricted to dermal papillar cells. In eccrine sweat glands, only few secretory cells were observed to express AR. Estrogen receptor (ER) alpha was poorly expressing, being restricted to sebocytes. In contrast, ERbeta was found to be highly expressed in the epidermis, sebaceous glands (basal cells and sebocytes) and eccrine sweat glands. In the hair follicle, ERbeta is widely expressed with strong nuclear staining in dermal papilla cells, inner sheath cells, matrix cells and outer sheath cells including the buldge region. Progesterone receptors (PR) staining was found in nuclei of some keratinocytes and in nuclei of basal cells and sebocytes in sebaceous glands. PR nuclear staining was also observed in dermal papilla cells of hair follicles and in eccrine sweat glands. This information on the differential localization of sex steroid receptors in human skin should be of great help for future investigation on the specific role of each steroid on skin and its appendages.     

beta-Catenin has sequential roles in the survival and specification of ventral dermis

The dermis promotes the development and maintains the functional components of skin, such as hair follicles, sweat glands, nerves and blood vessels. The dermis is also crucial for wound healing and homeostasis of the skin. The dermis originates from the somites, the lateral plate mesoderm and the cranial neural crest. Despite the importance of the dermis in the structural and functional integrity of the skin, genetic analysis of dermal development in different parts of the embryo is incomplete. The signaling requirements for ventral dermal cell development have not been established in either the chick or the mammalian embryo. We have shown previously that Wnt signaling specifies the dorsal dermis from the somites. In this study, we demonstrate that Wnt/beta-catenin signaling is necessary for the survival of early ventral dermal progenitors. In addition, we show that, at later stages, Wnt/beta-catenin signaling is sufficient for ventral dermal cell specification. Consistent with the different origins of dorsal and ventral dermal cells, our results demonstrate both conserved and divergent roles of beta-catenin/Wnt signaling in dermal development.     

Innervation and cholinesterase activity in the skin of albino and desert rats

The distribution of nerves and cholinesterase activity in the skin of the desert and albino rats has been studied using both histological and histochemical techniques. In the desert rat, the skin was richly innervated. Specific cholinesterase was concentrated in the nervous network of the dermis and around the hair follicles, in the nerve bundles of the dermis, in perivascular nerves, in fine intra-epithelial nerves and in sensory end organs in the junctional area between the dermis and epidermis. In the albino rat, specific cholinesterase was concentrated in the sebaceous glands. The positive cholinesterase activity that was seen in the desert rat in intra-epithelial nerves, and in dermal and hair follicle networks could not be demonstrated.     

Protein gene product 9.5-immunoreactive nerve fibres and cells in human skin

Summary Sections of human skin were processed according to the indirect immunofluorescence technique with a rabbit antiserum against human protein gene product 9.5 (PGP 9.5). Immunoreactivity was detected in intraepidermal and dermal nerve fibres and cells. The intraepidermal nerves were varicose or smooth with different diameters, running as single processes or branched, straight or bent, projecting in various directions and terminating in the stratum basale, spinosum or granulosum. The density of the intraepidermal nerves varied between the different skin areas investigated. PGP 9.5-containing axons of the lower dermis were found in large bundles. They separated into smaller axon bundles within the upper dermis, entering this portion of the skin perpendicular to the surface. Then they branched into fibres mainly arranged parallel to the epidermal-dermal junctional zone. However, the fibres en route to the epidermis traversed the upper dermis more or less perpendicularly. Furthermore, immunoreactive dermal nerve fibres were found in the Meissner corpuscles, the arrector pili muscles, hair follicles, around the eccrine and apocrine sweat glands and around certain blood vessels. Such fibres were also observed around most subcutaneous blood vessels, sometimes heavily innervating these structures. Numerous weakly-to-strongly PGP 9.5-immunoreactive cells were found both in the epidermis and in the dermis.     

Embryonic dermal condensation and adult dermal papilla induce hair follicles in adult glabrous epidermis through different mechanisms

Hair induction in the adult glabrous epidermis by the embryonic dermis was compared with that by the adult dermis. Recombinant skin, composed of the adult sole epidermis and the embryonic dermis containing dermal condensations (DC), was transplanted onto the back of nude mice. The epidermis of transplants formed hairs. Histology on the induction process demonstrated the formation of placode-like tissues, indicating that the transplant produces hair follicles through a mechanism similar to that underlying hair follicle development in the embryonic skin. An isolated adult rat sole skin piece, inserted with either an aggregate of cultured dermal papilla (DP) cells or an intact DP between its epidermis and dermis, was similarly transplanted. The transplant produced hair follicles. Histology showed that the epidermis in both cases surrounded the aggregates of DP cells. The epidermis never formed placode-like tissues. Thus, it was concluded that the adult epidermal cells recapitulate the embryonic process of hair follicle development when exposed to DC, whereas they get directly into the anagen of the hair cycle when exposed to DP. The expression pattern of Edar and Shh genes, and P-cadherin protein during the hair follicle development in the two types of transplants supported the above conclusion.     

Vitiligo-related neuropeptides in nerve fibers of the skin

Skin distribution of substance P (SP)-, somatostatin (SOM)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity (LI) in vitiligo patients was studied by an indirect immunofluorescence technique. Immunocytochemical characteristics of the epidermis, dermal-epidermal junction, papillary and reticular dermis and skin appendages were analyzed in lesional and marginal vitiligo areas, as well as in healthy skin. In healthy pigmented skin, SP-, SOM-, CGRP-, and NPY-LI nerve fibers were observed with specific distributional patterns. In uninvolved vitiligo skin, thin SP-containing fibers were evident in dermal papillae, extending into the epidermis, and SP-LI fibers were seen around blood vessels and sweat glands. SOM-LI varicose nerve fibers were associated with Meissner corpuscles in the dermal papillae, while CGRP-LI was demonstrated in the free subepidermal nerve terminals and in sensory nerve fibers around blood vessels, hair follicles and sweat glands. Autonomic NPY-nerve fibers innervated the eccrine sweat glands and blood vessels. The distribution of these neuropeptides in both marginal and lesional areas of vitiliginous skin was the same as in the skin of healthy control subjects, except for an increased immunoreactivity against NPY and, to a lesser extent, against CGRP in the skin depigmentation lesions. The elevated NPY levels in skin affected by vitiligo suggest that this peptide may serve as a neurochemical marker in the pathogenesis of the disease, thus supporting the neuronal theory of vitiligo.     

Histology of the sternal and suprapubic skin areas in lion tamarins (Leontopithecus sp. Callitrichidae-primates)

Though knowledge regarding the biology and morphology of lion tamarins is scarce in the literature, it is very important for their conservation. This paper focuses on the anatomical and histological aspects of the glands involved in the scent-marking behavior of lion tamarins. It examines the histological aspects of sternal and suprapubic skin sections of specimens that were preserved in formaldehyde and were the property of the Rio de Janeiro Primatology Center Museum. Eighteen specimens from three lion tamarin (Leontopithecus sp.) species (L. rosalia, L. chrysomelas, and L. chrysopygus) were analyzed. Both sexes were represented, and macroscopic hypertrophy was quantified by direct observation of the tegument on the sternal area and classified as discrete, moderate, or accentuated for each specimen. The skin of both sexes had a high degree of histological resemblance to that of other primates, including humans. The epidermis presented stratified squamous keratinous epithelia, with a few cellular layers and dermis with cutaneous appendages (i.e., hair follicles and both sebaceous and sweat glands). The dermal papillae were short, and the sebaceous and apocrine sweat glands resembled those of humans. These glands were present in the dermis of the analyzed skin fragments of both sternal and suprapubic regions in great numbers. Furthermore, we were able to establish a relationship between the macroscopic appearance of the sternal tegument and the degree of microscopic gland hyperplasia.     

Histology and cytochemistry of human skin. XI. The distribution of beta-glucuronidase

1. Various amounts of beta-glucuronidase activity may be found in all of the cutaneous appendages. 2. In the epidermis, the basal layer and the Malpighian layer contain a moderate amount of it, but a band of cells, including the stratum granulosum and the cells immediately above it, is rich in beta-glucuronidase. 3. The cells of the duct of eccrine sweat glands have moderately strong enzyme activity, but those in the secretory coil are strongly reactive; small and large reactive granules are crowded in the reactive cytoplasm. 4. The cells of the secretory coil of the apocrine glands contain more beta-glucuronidase than any other cutaneous appendage. 5. In the sebaceous glands, a very strong concentration of enzyme activity is found in the undifferentiated peripheral cells, a smaller amount of it is found in the differentiating cells. 6. In active hair follicles, the largest amount of beta-glucuronidase is found in the outer root sheath and in the bulb. In the outer sheath, the strongest concentration is found around the level of the keratogenous zone of the cortex. The dermal papilla is strongly reactive. In quiescent hair follicles, the outer root sheath has a moderate amount of enzyme concentration, but the dermal papilla is unreactive. 7. In the dermis, the fibroblasts in the papillary layer, the smooth muscle cells of the arrectores pilorum and the tunica media of arteries, and the fat cells all exhibit enzyme activity. Mast cells show a great concentration of beta-glucuronidase.     

Expression and localization of insulin-like growth factor-1 in normal and post-burn hypertrophic scar tissue in human

The migration of epithelial cells from dermal appendages toward the wound surface is essential for re-epithelialization of partial thickness burn injuries. This study provides evidence that these cells in vivo synthesize a mitogenic and fibrogenic factor, insulin-like growth factor-1 (IGF-1), which may promote the development of the post-burn fibroproliferative disorder, hypertrophic scarring (HSc). An evaluation of 7 post-burn hypertrophic scars, 7 normal skin samples obtained from the same patients and 4 mature scars revealed that IGF-1 expressing cells from the disrupted sweat glands tend to reform small sweat glands of 4-10 cells/gland in post-burn HSc. The number of these cells increases with time and the glands become larger in mature scar. Other epithelial cells such as those found in sebaceous glands and basal and suprabasal keratinocytes, also express IGF-1 protein and mRNA as detected by Northern and RT-PCR analysis of RNA obtained from whole skin and separated epidermis and dermis. However, cultured keratinocytes did not express mRNA for IGF-1. Histological comparisons between normal and HSc sections show no mature sebaceous glands in dermal fibrotic tissues but the number of IGF-1 producing cells including infiltrated immune cells was markedly higher in the dermis of hypertrophic scar tissues relative to that of the normal control. In these tissues, but not in normal dermis, IGF-1 protein was found associated with the extracellular matrix. By in situ hybridization, IGF-1 mRNA was localized to both epithelial and infiltrated immune cells. Collectively, these findings suggest that in normal skin, fibroblasts have little or no access to diffusible IGF-1 expressed by epithelial cells of the epidermis, sweat and sebaceous glands; while following dermal injury when these structures are disrupted, IGF-1 may contribute to the development of fibrosis through its fibrogenic and mitogenic functions. Reformation of sweat glands during the later stages of healing may, therefore, limit this accessibility, and lead to scar maturation.