The structure of the skin, types and distribution of mucous cell of yangtze sturgeon ( Acipenser dabryanus ) / La estructura de la piel, los tipos y distribución de las células mucosas del esturión yangtze ( Acipenser dabryanus )

The structural characteristics of the skin, types and distribution of mucous cells of Yangtze sturgeon (Acipenser dabryanus) were studied at the light microscope level, stained with Haematoxylin-eosin (HE) and Alcian blue-periodie acid Schiff (ABPAS). The skin of both was composed of epidermis and dermis. The dermis was divided into stratum spongiosum and stratum compactum. The stained color of stratum compactum was stained more deeply than that of stratum spongiosum. The skin thickness displayed differences in the fish at different body positions. The thickest of epidermis layer was on the dorsal region for Yangtze sturgeon, reversely, the thinnest was the mandibular region; Stratum spongiosum on the mandibular region was the thickest, the stratum spongiosum of the maxillary region was not obvious. In summary, keratinized spines, a kind of keratin derivative, are widely distributed in the mandibular, ventral, dorsal, and caudal peduncle skin surface for Yangtze sturgeon, and some pit organs mainly present in the skin surface of the maxillary and ventral regions. In short, the small amount of mucous cells in the skin of Yangtze sturgeon and the type of mucous cell were main Type IV, nevertheless there was a distribution of a few Type III.

Se estudiaron las características estructurales de la piel, los tipos y la distribución de las células mucosas del esturión Yangtze (Acipenser dabryanus) con microscopio de luz, teñidas con hematoxilina-eosina (HE) y azul alcián-ácido de Schiff (AB-PAS). La piel estaba compuesta por epidermis y dermis. La dermis se dividía en estrato esponjoso y estrato compacto. El grosor de la piel mostró diferencias en los peces en diferentes posiciones del cuerpo. La capa más gruesa de la epidermis se observó en la región dorsal del esturión Yangtze; a la inversa, la más delgada en la región mandibular. El estrato esponjoso en la región mandibular era el más grueso, el estrato esponjoso de la región maxilar no era visualizado. En resumen, las espinas queratinizadas, un tipo derivado de la queratina, estaban ampliamente distribuidas en la superficie de la piel del pedúnculo mandibular, ventral, dorsal y caudal en el esturión Yangtze, y algunos órganos en fosas, presentes principalmente en la superficie de la piel de las regiones mandibular y ventral. En resumen, la pequeña cantidad de células mucosas en la piel del esturión Yangtze y el tipo de célula mucosa eran células principales tipo IV, sin embargo, se observaron algunas células tipo III.

Histological description of the skin glands of Phyllobates bicolor (Anura: Dendrobatidae) using three staining techniques / Descripción histológica de las glándulas cutáneas de Phyllobates bicolor (Anura: Dendrobatidae) usando tres técnicas de tinción

The mechanisms to obtain and store skin toxins in frogs in of the family Dendrobatidae are not completely understood. In order to contribute to understand how toxins are stored, we provide a histological description of the cutaneous glands of the species Phyllobates bicolor. The skin of two adult frogs was examined through three histological staining techniques (hematoxilin-eosin, PAS and Masson Trichrome) using conventional optic microscopy. The skin of Phyllobates bicolor contains two types of exocrine glands: mucous and serous, which empty their products to the epidermal surface through an intra-epithelial duct that leads to a stoma. The mucous and serous glands and the intercalated ducts are surrounded by a discontinuous sheath of myoepithelial cells, which colapse the lumen of the acinus and the lumen of ducts and facilitate the secretion and release of their content. The serous glands have a polarized syncytium of tall cuboidal or columnar epithelial cells. Both glands have a mixed secretion, thus, the contents of mucous glands tend to be neutral and basophilic, while the contents of the serous glands are basophilic and acidophilic.

A la fecha no existe mayor información con respecto a los mecanismos para obtener y almacenar las toxinas cutáneas de ranas de la familia Dendrobatidae. Con el fin de contribuir y entender cómo son almacenadas estas toxinas, realizamos una descripción histológica de las glándulas cutáneas de la especie Phyllobates bicolor. La piel de dos ranas adultas se examinó mediante tres técnicas de tinción histológica (hematoxilina-eosina, PAS y tricrómico de Masson) mediante microscopía óptica convencional. La piel de P. bicolor contiene dos tipos de glándulas exocrinas: mucosas y serosas, que vierten sus productos a la superficie epidérmica a través de un conducto intra-epitelial que conduce a un estoma. Las glándulas mucosas, serosas y los conductos intercalados están rodeados por una funda discontinua de células mioepiteliales, las que colapsan el lumen de los acinos y conductos, facilitando la secreción y liberación de su contenido. Las glándulas serosas tienen un sincitio polarizado de células epiteliales columnares cúbicas. Ambas glándulas tienen una secreción mixta, por lo tanto, los contenidos de las glándulas mucosas tienden a ser neutral y basófilas, mientras que los contenidos de las glándulas serosas son basófilas y acidófilas.

Histological study on the effect of gasoline on guinea pig epidermis: can flavonoid extract reverse this effect?

Car fuel, containing gasoline, is reported to have an irritative effect on mammalian skin. This study aimed to detect the cellular changes in the epidermis of male guinea pig back skin evoked by repeated exposure to gasoline and to evaluate the role of flavonoid extract in reversing these changes. Thirty-five guinea pigs, divided into a control [n=5] group I and an experimental [n=30] group II were used. The latter was divided into two subgroups; the guinea pigs in the first subgroup [group IIa] were painted with gasoline twice daily for 21 days and those in the second [group IIb] were treated with flavonoid extract after previous gasoline dermal application. Animal skin was dissected and processed for light and electron microscopic examination; further, statistical analysis was performed to compare the epidermal thickness in different groups. Naked eye examination of skin of guinea pigs in group IIa showed erythema and ulceration. In addition, a significant increase in epidermal thickness was observed by light microscopy. Ultrastructural changes include an ill-defined dermo-epidermal junction and basal layer cells showing an electron-dense cytoplasm, increased lysosomal dense bodies, and swollen mitochondria. Their nuclei showed an irregular nuclear envelope and peripheral chromatin condensation. The prickle layer cells showed dissolution of desmosomal junctions and cytoplasmic vacuolation. Granular cell layers showed a marked decrease in fibrillar contents and the horny layer showed separation of individual layers by flocculent-filled spaces. The flavonoid-treated group showed a significant decrease in epidermal thickness [compared with the gasoline-painted group] and most of the epidermal cells appeared normal with intact nuclei. Safety measures, as well as orientation programs, are recommended for car fuel-filling workers exposed to continuous contact with gasoline, to avoid its drastic effect on skin. Application of flavonoid orange extracts is recommended as they ameliorate this effect

Histological study of the dynamics in epidermis regeneration of the carp tail fin (Cyprinus carpio, Linnaeus, 1758) / Estudo histológico da dinâmica da regeneração da epiderme da nadadeira caudal da carpa (Cyprinus carpio Linnaeus, 1758)

Teleostean fins when partially amputated suffer a regenerative process called epimorphic regeneration, characterized by the following stages: healing, based on the formation of a multistratified epidermal layer, the formation of a mass of pluripotent cells known as blastema, the differentiation of these cells, the synthesis and disposition of the extracellular matrix, morphological growth and restoration. The epidermis has a fundamental role in the regenerative process of fish fins, as the healing time of this structure leads it to a faster regenerative process and it also works as a defense against the external environment. In this sense, due to the fast regeneration shown by the epidermis, the aim of this paper is to study the histology of the regenerative dynamics of the carp fin tail (Cyprinus carpio), under the light and transmission electron microscope. Epidermic regeneration begins right in the first hours after the fin amputation and it continues throughout the regenerative process. After 24 hours, an apical epidermal cap is established. Cytoplasmatic prolongations and intercellular junctions are observed and the cells of the basal layer of the epidermis change from the cubic form to the cylindrical, due to the development of the cytoplasmatic organelles responsible for the synthesis of the basal membrane, lost after amputation. These results show the importance of histological studies in regenerative processes. We believe that the association of molecular biology with histological studies can throw further light onto these regenerative dynamics.

As nadadeiras dos teleósteos, quando parcialmente amputadas, sofrem um processo de regeneração chamado de regeneração epimórfica, caracterizado pelas seguintes fases: cicatrização, a partir da formação de uma capa epidermal multiestratificada, formação de uma massa de células mesenquimais multipotentes chamada blastema, diferenciação dessas células, síntese e deposição de matriz extracelular, crescimento e restauração morfológica. A epiderme tem papel fundamental no processo regenerativo das nadadeiras dos peixes, uma vez que a velocidade de cicatrização dessa estrutura leva a um processo regenerativo mais rápido e, também, age como uma defesa contra o ambiente externo. Assim, devido à rápida regeneração que a epiderme apresenta, tivemos como objetivo, neste trabalho, estudar a histologia da dinâmica regenerativa da epiderme das nadadeiras caudais da carpa (Cyprinus carpio) ao microscópio de luz e eletrônico de transmissão. A regeneração da epiderme tem início já nas primeiras horas após a amputação das nadadeiras e continua durante todo o processo regenerativo. Após 24 horas, uma capa epidermal apical é estabelecida. Prolongamentos citoplasmáticos e junções intercelulares são observados e as células da camada basal da epiderme passam da forma cúbica para a cilíndrica, devido ao desenvolvimento das organelas citoplasmáticas responsáveis pela síntese da membrana basal perdida após a amputação da nadadeira. Estes resultados mostram a importância de estudos histológicos em processos regenerativos. Acreditamos que a associação da biologia molecular a estes estudos histológicos poderá elucidar ainda melhor esta dinâmica regenerativa.

Analysis of the microstructure of Xenodontinae snake scales associated with different habitat occupation strategies / Análise da microestrutura de escamas de serpentes Xenodontinae em associação à ocupação de diferentes microhabitats

The morphology of many organisms seems to be related to the environment they live in. Nonetheless, many snakes are so similar in their morphological patterns that it becomes quite difficult to distinguish any adaptive divergence that may exist. Many authors suggest that the microornamentations on the scales of reptiles have important functional value. Here, we examined variations on the micromorphology of the exposed oberhautchen surface of dorsal, lateral, and ventral scales from the mid-body region of Xenodontinae snakes: Sibynomorphus mikani (terricolous), Imantodes cenchoa (arboreal), Helicops modestus (aquatic) and Atractus pantostictus (fossorial). They were metallized and analyzed through scanning electron microscopy. All species displayed similar microstructures, such as small pits and spinules, which are often directed to the scale caudal region. On the other hand, there were some singular differences in scale shape and in the microstructural pattern of each species. S. mikani and I. cenchoa have larger spinules arranged in a row which overlap the following layers on the scale surface. Species with large serrate borders are expected to have more frictional resistance from the caudal-cranial direction. This can favor life in environments which require more friction, facilitating locomotion. In H. modestus, the spinules are smaller and farther away from the posterior rows, which should help reduce water resistance during swimming. The shallower small pits found in this species can retain impermeable substances, as in aquatic Colubridae snakes. The spinules adhering to the caudal scales of A. pantostictus seem to form a more regular surface, which probably aid their fossorial locomotion, reducing scale-ground friction. Our data appear to support the importance of functional microstructure, contributing to the idea of snake species adaptation to their preferential microhabitats.

A morfologia de muitos organismos parece estar relacionada ao ambiente em que eles vivem. No entanto, muitas serpentes são tão similares nos seus padrões morfológicos que se torna difícil distinguir qualquer divergência adaptativa existente. Muitos autores sugerem que as micro-ornamentações nas escamas de répteis possuem importante valor funcional. Neste trabalho, examinamos variações na micromorfologia da superfície oberhautchen exposta das escamas ventrais, laterais e dorsais da região medial de serpentes Xenodontinae: Sibynomorphus mikani (terrestre), Imantodes cenchoa (arbórea), Helicops modestus (aquática) e Atractus pantostictus (fossorial). Estas foram metalizadas e analisadas por microscopia eletrônica de varredura. Todas as espécies apresentaram microestruturas similares, tais como microcovas e espículas, que estão normalmente orientadas para a região caudal da escama. Por outro lado, houve algumas diferenças singulares em relação ao formato da escama e padrão microestrutural de cada espécie. S. mikani e I. cenchoa possuem espículas grandes arrumadas em linhas que sobrepõem as camadas seguintes da superfície da escama. Em espécies que possuem longas denticulações sobrepostas sobre as bordas posteriores das células, é esperado que haja uma maior resistência friccional da direção posterior para anterior das escamas. Isso pode favorecer a vida em ambientes que precisam de maior atrito, facilitando a locomoção. Em H. modestus, as espículas são menores e mais afastadas das linhas posteriores, o que pode reduzir o atrito com a água durante a natação. As microcovas mais rasas encontradas nesta espécie podem reter substâncias impermeáveis, como nas serpentes Colubridae aquáticas. As espículas que aderem às escamas caudais de A. pantostictus parecem formar uma superfície mais regular, o que provavelmente auxilia na locomoção fossorial, reduzindo o atrito com o solo. Nossos dados parecem corroborar a importância da microestrutura funcional, ...

Transmission electron microscopy of the preclinical phase of experimental phytophotodermatitis

OBJECTIVE: To examine the epidermis in induced phytophotodermatitis using transmission electron microscopy in order to detect histologic changes even before lesions are visible by light microscopy. INTRODUCTION: In the first six hours after the experimental induction of phytophotodermatitis, no changes are detectable by light microscopy. Only after 24 hours can keratinocyte necrosis and epidermal vacuolization be detected histologically, and blisters form by 48 hours. METHODS: The dorsum of four adult rats (Rattus norvegicus) was manually epilated. After painting the right half of the rat with the peel juice of Tahiti lemon, they were exposed to sunlight for eight minutes under general anesthesia. The left side was used as the control and exposed to sunlight only. Biopsies were performed immediately after photoinduction and one and two hours later, and the tissue was analyzed by transmission electron microscopy. RESULTS: No histological changes were seen on the control side. Immediately after induction, vacuolization in keratinocytes was observed. After one hour, desmosomal changes were also observed in addition to vacuolization. Keratin filaments were not attached to the desmosomal plaque. Free desmosomes and membrane ruptures were also seen. At two hours after induction, similar changes were found, and granular degeneration of keratin was also observed. DISCUSSION: The interaction of sunlight and psoralens generates a photoproduct that damages keratinocyte proteins, leading to keratinocyte necrosis and blister formation. CONCLUSIONS: Transmission electron microscopy can detect vacuolization, lesions of the membrane, and desmosomes in the first two hours after experimental induction of phytophotodermatitis.

Estudio inmunohistoquímico del colágeno tipo I y tipo III en piel de pacientes con hernia inguinal primaria / Immunohistochemical measurement of type I and III collagen content of the skin of patients with primary inguinal hernia

La etiopatogenia de la hernia inguinal es completa y multifactorial. Hay factores biomecánicos, metabólicos y genéticos asociados al desarrollo de hernias inguinales pero el sustrato estructural íntimo que determina la aparición de la hernia no se conoce con exactitud. En la piel y fascia transversalis hay una composición de colágeno tipo I y tipo III similar que es cuantificable por distintas técnicas, que se mantiene constante en individuos normales y se altera en individuos con hernia. El objetivo de ésta investigación es efectuar un estudio morfológico con inmunohistoquímica, en piel de pacientes portadores de hernia inguinal primara, operados en el Servicio de Cirugía del Hospital Regional de Temuco entre abril y diciembre de 2002 y compararlos con un grupo de sujetos sin hernia. El diseño propuesto es un estudio de casos y controles con tamaño de muestra estimado en 9 casos y 9 controles. El protocolo fue aprobado por el Comité de Ética de la Facultad de Medicina de la Universidad de La Frontera. Cada sujeto en estudio firmó un consentimiento informado autorizando la toma de muestra e inclusión en el protocolo. La distribución de las fibras de colágeno tipo I no mostró diferencias significativas. En los pacientes con hernia inguinal encontramos una mayor concentración de fibras de colágeno tipo III en los sectores más superficiales de la dermis (dermis papilar) y alrededor de los anexos de la piel, a diferencia de lo que sucede en los pacientes sin hernia. Al cuantificar la proporción de colágeno I/III por inmunohistoquímica obtuvimos un valor de 1,28 en sujetos sin hernia y 0,79 en pacientes con hernia inguinal primaria, siendo esta diferencia estadísticamente significativa. Como conclusión se puede establecer que hay una alteración de la calidad y cantidad de las fibras colágenas y de la proporción de colágeno I/III en piel de pacientes portadores de hernia inguinal primaria al compararlos con sujetos sin hernia inguinal.

Padronização normal das fibras nervosas intraepidérmicas em 30 voluntários saudáveis com PGP 9, 5 / Normal pattern of intraepidermal nerve fibers in 30 healthy volunteers with PGP 9.5

O recente método de avaliação das fibras nervosas intraepidérmicas com o PGP 9,5 vem se mostrando de grande utilidade no diagnóstico das neuropatias sensitivas de fibras finas, autonômicas e neuropatias periféricas subclínicas. Devido à variação da técnica relatada na literatura é de fundamental importância uma padronização normal. Estudamos 15 homens e 15 mulheres com média de idade de 34,5 anos. Em todos os voluntários foi realizada biopsia de pele na porção distal da perna. A média da densidade linear das fibras nervosas intraepidérmicas foi 5,3/mm com mediana de 6,0 e desvio padrão de 1,94. Essa técnica possui um grande número de vantagens em relação à biopsia de nervo convencional, é simples, pouco invasiva, reproduzível e pode ser repetida no mesmo paciente para avaliar progressão da neuropatia e possíveis respostas terapêuticas.

Union dermoepidermica: una barrera selectiva, compleja y vital / Dermoepidermic junction: a selective, complex and vital barrier

La Unión Dermoepidérmica, (UDE) es una región altamente compleja, la cual contiene una gran variedad de elementos celulares, los cuales a pesar de tener un origen embriológico distinto, interaccionan entre sí, generando diferentes sustancias, las cuales mantienen la funcionalidad y homeostasis del órgano más extenso del organismo. La UDE es considerada una lámina basal, altamente especializada, la actual actúa como una ruta altamente selectiva para la migración celular y macromolecular, induciendo la diferenciación celular y actuando sobre el metabolismo del microambiente. En la UDE se distinguen tres zonas, tomando como punto de referencia a la membrana basal 1- la zona más cercana a epidermis, la cual contiene tonofilamentos y hemidesmosomas, los cuales mantienen ancladas las células basales. Esta región se prolonga hasta la lámina densa, 2-la zona intermedia abarca sólo la lámina densa, 3- esta zona se prolonga desde la lámina densa hasta las porciones superiores de la dermis y matriz extracelular. A pesar de que aún existen muchos enigmas moleculares de la UDE, el conocimiento de cada molécula y la función de los distintos compartimentos que la integran, permitirá ampliar los conocimientos fisiopatogénicos de diversas entidades dermatológicas frecuentes en la práctica clínica diaria.

Microscopic analysis of epidermal melanocytes in human abdominal skin

Microscopic analysis of epidermal melanocytes in human abdominal skin with respect to age and sex. Design: Cross sectional study. Place and Duration of Study: Department of Anatomy. BMSI, JPMC, Karachi. About one year in 1998. Subjects and Demonstration of epidermal melanocytes in 5mm thick vertical paraffin embedded sections of thirty-eight skin samples from different age and sex groups, using dihydroxyphenyl alanine [Dopa] reagent. The melanocytes count per unit area of skin was significantly higher in the younger than older age groups. No significant difference was noticed between males and females epidermal melanocytes counts. Distribution of epidermal melanocytes was inversely proportional to the advancing age. However, there was no significant gender differences in the distribution of epidermal melanocytes

Hiperqueratose epidermolítica: relato de caso e revisäo da classificaçäo / Epidermolytic hyperkeratosis: a case report and classification review

A hiperqueratose epidermolítica é doença rara de herança autossômica dominante. Caracteriza-se inicialmente pela presença de eritema generalizado, descamaçäo e bolhas, e posteriormente com a evoluçäo, hiperqueratose. A histologia é característica, apresentando hiperqueratose associada à epidermólise no nível da camada granulosa e espinhosa, e à ultra-estrutura observa-se agrupamento de tonofilamentos densos. Os autores relatam um caso de hiperqueratose epidermolítica, com aspectos histológicos e ultra-estrutura típicos. De acordo com a revisäo da literatura, algumas características em relaçäo à classificaçäo, manifestaçäo clínica e ao diagnóstico diferencial säo abordados

Effect of long-term exposure to su-light on the ultrastructure of epidermal melanin unit of the human skin

The aim of the present work was to study the ultrastructural features of the melanocytes and related keratinocytes in chronically sun- exposed skin. 10 fair-skinned adult males, whose occupation required long exposure to sun light were chosen for this study. Chronic exposure to sun light enhanced the proliferative activity of the epidermal melanocytes accompanied by increased melanin content, variable dendritic morphology and appearance of numerous pinocytotic vesicles and vacuoles. Moreover, migration of melanocytes were demonstrated in the sun-exposed skin into suprabasal and subbasal [dermal] positions. Groups of melanocytes were demonstrated in the superficial part of the dermis denoting nest formation. In addition, chronic exposure to sun light induced marked proliferation of the epidermal keratinocytes leading to increased epidermal thickness. Also, their pigment content was increased due to enhanced melanin transfer from the nearby melanocytes. Moreover, there was concentric condensation of the excess melanin pigments and cytoplasmic tonofilaments around their nuclei forming a shield to protect the nuclear DNA against the harmful effect of solar ultraviolet rays

Xerosis. Pérdida de la función de la piel como barrera / Xerosis. Loss of the barrier function of the skin

La piel no es una envoltura inerte. Con una extensión promedio de 1.82 m², es un órgano anatómico y funcionalmente complejo, el cual es un marcador importante de salud. De las múltiples funciones de la piel, la de ser barrera es una de las más destacables. Gracias a estos se evitan diversas alteraciones. La función de barrera puede ser modificada por factores individuales (sexo, edad), internos (sustancias hidroscópicas, proteínas fibrosas, pérdida transepidérmica de agua) y externos (humedad relativa, temperatura ambiental). Uno de los signos más importantes cuando hay alteraciones en esta función de barrera es la xerosis o "piel seca". Se revisan algunos aspectos de la unidad proliferativa epidérmica que condicionan el desarrollo de xerosis

ultrastructural study of epidermal-melanin unit in vitiligo

The use of electron microscopy to define the cellular changes in vitiligo might prove to be a useful investigative procedure to clarify the pathogenic mechanism of this disease. Examination of vitiligenous skin taken from the margin and center of the depigmented lesions revealed ultrastructural changes in the form of cytoplasmic vacuoles in basal and suprabasal keratinocytes and deposits of extra-cellular granular material in between the keratinocytes in lower epidermis. Melanocytes and melanosomes were completely absent, while Langerhans' cells showed highly vacuolated cytoplasm. There was marked increased in degenerated Langerhans' cells in the center of the vitiligenous lesions. It seems logical to propose that degenerative changes in vitiligo do not only involve the melanocytes, but also keratinocytes and Langerhans' cells i.e. the whole epidermal- melanin unit

effect of exposure to cold on epidermal permeability barrier in albino rat [light and electron microscope study]

This study was carried out on 15 adult albino rats to determine the effect of cold exposure on epidermal permeability barrier. Rats were divided into two groups [a control group and an experimental group] and their soles were treated with topical acetone to disrupt epidermal barrier. The experimental group was subdivided into two subgroups [animals left in empty cages and animals subjected to a steady contact with ice]. The examination of both semithin and ultrathin sections showed that epidermis of soles of the control animals consisted of thick stratum corneum formed of very flat, heavily keratinized cells. After four hours, the acetone treated soles showed relatively paler stratum corneum in semithin sections and empty spaces between the horny cells in the ultrastructure examination. The animals whose soles were treated with acetone and left for four hours in contact with ice showed broken down stratum corneum in large areas in the semithin sections. Electron microscopy revealed abnormally empty or early empty vacuoles [disorganized lamellar bodies] in both stratum granulosum and stratum spinosum

Ausência de melanócitos na epiderme do gambá (Didelphis azarae) adulto / Absence of melanocytes in the epidermis of the adult opossum (Didelphis azarae)

Estudou-se a presença de melanina na epiderme do gambá (Didelphis azarae). Este pigmento näo foi observado histoquimicamente e o estudo ultra-estrutural confirmou a ausência de melanócitos típicos, com ou sem grânulos de melanina