Diseño y fabricación de modelos impresos en 3D como complemento para las clases prácticas de histología médica / Design and manufacturing of 3D printed models as a complement for medical histology practical classes

RESUMEN: Tradicionalmente, la Histología se ha apoyado del análisis de preparaciones histológicas a través del microscopio para su enseñanza. En este sentido, uno de los principales obstáculos que enfrentan los estudiantes al analizar los tejidos, es extrapolar una imagen bidimensional a una estructura tridimensional (3D). La impresión 3D permite subsanar esta limitación, haciendo posible fabricar material docente, con las características requeridas con un alto grado de detalle y bajo costo. El objetivo de este trabajo fue diseñar y fabricar modelos impresos en 3D como complemento para las clases prácticas de Histología Médica. Se fabricaron modelos impresos en 3D de la ultraestructura de la barrera de filtración glomerular (BFG) en su estado normal y síndrome nefrótico. Además, se fabricó un modelo de la capa muscular del esófago humano dando énfasis a la disposición helicoidal de sus fibras musculares. Los modelos de epidermis permitieron identificar sus distintos estratos: estrato córneo, estrato granuloso, estrato espinoso, y estrato basal. Dentro los beneficios derivados de la impresión de modelos en 3D podemos destacar el bajo costo económico de su fabricación, alta reproducibilidad, bioseguridad, y potencial para favorecer el aprendizaje y la enseñanza de la Histología. No obstante, es necesario analizar la percepción y beneficio sobre el aprendizaje de los estudiantes derivados de la aplicación de los modelos mediante técnicas de evaluación cuantitativas y cualitativas.

SUMMARY: Traditionally, Histology has relied on the analysis of histological slides through the microscope for its teaching. In this sense, one of the main obstacles faced by students when analyzing tissues is to extrapolate a two-dimensional image to a three-dimensional (3D) structure. 3D printing makes it possible to overcome this limitation, making it possible to manufacture teaching material with the required characteristics with a high degree of detail and low cost. The objective of this work was to design and manufacture 3D printed models as a complement for the practical classes of Medical Histology. 3D printed models of the ultrastructure of the glomerular filtration barrier (GFB) in its normal state and nephrotic syndrome were fabricated. In addition, a model of the muscular layer of the human esophagus was fabricated emphasizing the helical arrangement of its muscle fibers. The epidermis models allowed the identification of its different layers: stratum corneum, stratum granulosum, stratum spinosum, and stratum basale. Among the benefits derived from 3D printing of models, we can highlight the low economic cost of manufacturing, biosafety and potential to favor the learning and teaching of Histology. However, it is necessary to analyze the perception and benefit on student learning derived from the application of the models by means of quantitative and qualitative evaluation techniques.

Pagetoid dyskeratosis in dermatopathology

Abstract Currently, pagetoid dyskeratosis is believed to involve an accelerated keratinization process, possibly induced by mechanical trauma. It represents, in almost its totality, incidental histological findings of specific cells, except when it occurs in the hands, where it usually occurs simultaneously with skin lesions and local dyschromia. These are large, rounded keratinocytes, with pale cytoplasm and a pyknotic nucleus surrounded by a clear halo, which can be easily mistaken by other skin diseases. Its etiology is not completely elucidated, and the correct identification of this entity can be of great importance in the differential diagnosis of skin disorders and the understanding of the keratinization process of the epidermis.

Impact of constant light exposure during pregnancy on skin of neonatal New Zealand rabbits: structural and ultrastructural study

Continuous industrial productivity and modern societies have resulted in excess artificial light. The altered circadian rhythm causes many diseases. During intrauterine life, the mother's maternal melatonin rhythm has a major role in influencing organ development. The aim of this study was to investigate the effect of maternal exposure to constant light on the structure and ultrastructure of neonatal skin. Twenty pregnant New Zealand rabbits were divided into two groups (n=10 each): control group (12-h light/dark) and constant light group (24-h light). Plasma maternal melatonin and corticosterone during pregnancy were determined. At the end of the experiment, the dorsal skin of the neonates of both groups was collected and prepared for histological, morphometric, and transmission electron microscopic study. Histological and morphometric results of skin of neonates from the constant light group revealed statistically significantly reduced epidermal thickness, decreased number of hair follicle, increased surface area of collagen, and decreased proliferating cell nuclear antigen (PCNA) positive cells. Ultrastructural examination showed wide intercellular spaces and disrupted desmosomal junctions in the epidermis. Earlier stages of hair follicles were also observed with indented shrunken nuclei, vacuolization, and swollen mitochondria. Dermal fibroblasts with dilated cisternae of rough endoplasmic reticulum containing electron-dense material were detected. Maternal melatonin was significantly reduced in the constant light group while maternal corticosterone showed no significant difference between groups. Therefore, normal maternal circadian rhythm is a key factor for the integrity of neonatal skin structure.

Necrólisis epidérmica tóxica, a propósito de un caso / Toxic epidermal necrolysis, a case report

Introducción: La necrólisis epidérmica toxica (NET) son reacciones cutáneas más severas que ocurren en los niños. Los medicamentos son los principales inductores del problema. Se ha empleado inmunoglobulina humana intravenosa (IGIV) en problemas autoinmunes de la piel, incluyendo reacciones cutáneas severas por medicamentos. Informe del caso: Paciente de seis años de edad con antecedentes de a haber recibido 3 semanas previas cefalosporina de tercera generación, es internada por cuadro clínico de tres días con alzas térmicas, rinorrea, estornudos, náuseas, odinofagia, disfagia, hiporexia, hiperemia conjuntival, tos, episodios de desaturación y erupción cutánea que se inició en la cara y se extendió al tronco y extremidades. Examen físico. Paciente decaída, febril, en mal estado general, aparición de lesiones cutáneas eritematosas maculopapulares con rápida evolución a formación de flictenas con desprendimiento de la epidermis (Nikolski positivo), con afectación mayor al 30% de superficie corporal. Se observó conjuntivitis no purulenta; eritema y hemorragia de encías y labios, informe de anatomía patológica de lesiones cutáneas concluyó en NET. Se le administró IGIV a 1 g/kg/dosis/día. Al segundo día y segunda dosis, las lesiones cutáneas mejoraron. Discusión. La IGIV se ha utilizado en niños con reacciones cutáneas severas inducidas por drogas, con respuesta favorable, a partir de la 2 dosis de su administración.

Introduction: Toxic epidermal necrolysis (NET) are more severe skin reactions that occur in children. Medications are the main inducers of the problem. Human intravenous immunoglobulin (IGIV) has been used in autoimmune skin problems, including severe skin reactions from medications. Case report: Six-year-old patient with a history of having received third generation cephalosporin 3 weeks previously, hospitalized for a clinical picture of three days with thermal rises, rhinorrhea, sneezing, nausea, odynophagia, dysphagia, hyporexia, conjunctival hyperemia, cough, episodes of desaturation and skin rash that started on the face and spread to the trunk and extremities. Physical exam. Decayed, feverish patient, in poor general condition, appearance of maculopapular erythematous skin lesions with rapid evolution to formation of blisters with detachment of the epidermis (Nikolski positive), with involvement greater than 30% of body surface. Non-purulent conjunctivitis was observed, erythema and bleeding gums and lips, report of pathological anatomy of cutaneous lesions concluded in NET. IGIV was administered at 1 g/kg/dose/day. On the second day and second dose, the skin lesions improved. Discussion. IVIG has been used in children with severe drug-induced skin reactions, with a favorable response, from the 2nd dose of administration.

Caracterización de la población con obstrucción de poros faciales a quienes se les aplico laserterapia en la Unidad de Dermatología UNIMEL / Characterization of the population with facial pore obstruction to whom laser therapy was applied at the UNIMEL Dermatology Unit / Caracterização da população com obstrução dos poros faciais a quem foi aplicada terapia a laser no Serviço de Dermatologia da UNIMEL

INTRODUCCIÓN: el poro es un orificio de excreción que se encuentra en la epidermis de la piel, en donde pueden producirse problemas de eliminación deficiente del sebo en personas que presentan exceso de grasas. OBJETIVO: analizar las características y tratamiento laser aplicado a la población con obstrucción de poros faciales que acuden a la consulta de la Unidad de Dermatología UNIMEL. MATERIALES Y MÉTODOS: estudio descriptivo, de campo, prospectivo y transversal, la población fue de 653 pacientes de ambos sexos que acudieron a la consulta de dermatología y recibieron laserterapia por presentar obstrucción de poros faciales. Se aplicó estadística descriptiva para la representación de datos. El instrumento utilizado fue una lista de registro. RESULTADOS: los pacientes presentaron una edad promedio de 37 años, se aplicaron diferentes tratamientos según los criterios diagnósticos, se les realizó el procedimiento de fotona Black peel en un 0,15%, Vela de Nova en un 5,05% y Qs Quimioespectra a un 94,79% que representan un total de 619 personas. CONCLUSIÓN: el mayor grupo de pacientes que asistió a tratamiento se ubicó entre los 31 a 40 años de edad, un alto porcentaje mujeres afectadas por secuelas de daño facial producido por obstrucción de los poros y acumulación de sebo, un grupo importante 48,8% presenta acné posterior a los 18 años de edad.

INTRODUCTION: the pore is an excretion hole found in the epidermis of the skin, where problems of poor sebum removal can occur in people with excess fat; irregular synthesis occurs in the production of sebum increases its production with occlusion of the pores by dead cells. OBJECTIVE: to analyze the characteristics and laser treatment applied to the population with facial pore obstruction that come to the UNIMEL Dermatology Unit consultation. METHODS: a descriptive, field, prospective and cross-sectional study, the study population was 653 patients of both sexes who attended the dermatology consultation and received laser therapy for presenting facial pore obstruction. Descriptive statistics were applied for data representation. The instrument used was a registration list. RESULTS: the patients had an average age of 37 years, different treatments were applied according to the diagnostic criteria, and the photone Black peel procedure was performed in 0.15%, Nova candle in 5.05% and Qs Chemospectra at 94.79% representing a total of 619 people. CONCLUSION: the largest group of patients who attended treatment was between 31 to 40 years of age, a high percentage of women affected by sequelae of facial damage caused by pore obstruction and sebum accumulation, an important group 48.8% you have acne after 18 years of age.

INTRODUÇÃO: o poro é um orifício de excreção que se encontra na epiderme da pele, onde podem ocorrer problemas com a má remoção de sebo em pessoas com excesso de gordura. OBJETIVO: analisar as características e o tratamento a laser aplicado à população com obstrução de poro facial que frequenta a consulta do Serviço de Dermatologia da UNIMEL MATERIAIS E MÉTODOS: estudo descritivo, de campo, prospectivo e transversal, a população foi de 653 pacientes de ambos os sexos que compareceu à consulta de dermatologia e recebeu terapia a laser devido à obstrução dos poros faciais. Estatísticas descritivas foram aplicadas para representar os dados. O instrumento utilizado foi uma lista de registro. RESULTADOS: os pacientes tinham idade média de 37 anos, diferentes tratamentos foram aplicados de acordo com os critérios diagnósticos, o procedimento de fotone Black peel foi realizado em 0,15%, Vela de Nova em 5,05% e Qs Chemospectra em 94,79% representando um total de 619 pessoas. CONCLUSÃO: o maior grupo de pacientes que frequentou o tratamento teve entre 31 e 40 anos de idade, elevado percentual de mulheres acometidas por sequelas de lesões faciais causadas por obstrução de poros e acúmulo de sebo, importante grupo 48,8% tem acne após 18 anos de idade.

Immunohistochemical analysis of S100-positive epidermal Langerhans cells in dermatofibrom

Abstract Dermatofibroma is a dermal fibrohistiocytic neoplasm. The Langerhans cells are the immunocompetent cells of the epidermis, and they represent the first defense barrier of the immune system towards the environment. The objective was to immunohistologically compare the densities of S100-positive Langerhans cells in the healthy peritumoral epidermis against those in the epidermis overlying dermatofibroma (20 cases), using antibodies against the S100 molecule (the immunophenotypic hallmark of Langerhans cells). The control group (normal, healthy skin) included ten healthy age and sex-matched individuals who underwent skin biopsies for benign skin lesions. A significantly high density of Langerhans cells was observed both in the epidermis of the healthy skin (6.00 ± 0.29) and the peritumoral epidermis (6.44 ± 0.41) vs. those in the epidermis overlying the tumor (1.44 ± 0.33, p < 0.05). The quantitative deficit of Langerhans cells in the epidermis overlying dermatofibroma may be a possible factor in its development.

A randomized half-body, double blind, controlled trial on the effects of a pH-modified moisturizer vs. standard moisturizer in mild to moderate atopic dermatitis,

Abstract Background: Higher skin pH in atopic dermatitis contributes to impaired epidermal barrier. A moisturizer compatible with physiological pH could improve atopic dermatitis. Objective: To determine the effect of a physiologically compatible pH moisturizer in atopic dermatitis. Methods: A randomized half body, double blind, controlled trial involving patients with stable atopic dermatitis was performed. pH-modified moisturizer and standard moisturizer were applied to half body for 6 weeks. Results: A total of 6 (16.7%) males and 30 (83.3%) females participated. Skin pH reductions from week 0, week 2 and 6 were significant at the forearms (5.315 [0.98] to 4.85 [0.54] to 5.04 [0.78], p = 0.02) and abdomen (5.25 [1.01], 4.82 [0.64], 5.01 [0.59], p = 0.00) but not at the shins (5.01 [0.80], 4.76 [0.49], 4.85 [0.79], p = 0.09) with pH-modified moisturizer. Transepidermal water loss (TEWL) at the forearms decreased (4.60 [2.55] to 3.70 [3.10] to 3.00 [3.55], p = 0.00), abdomen (3.90 [2.90] to 2.40 [3.45] to 2.70 [2.25], p = 0.046). SCORAD improved from 14.1 ± 12.75 to 10.5 ± 13.25 to 7 ± 12.25, p = 0.00. In standard moisturizer group, pH reductions were significant at the forearms (5.29 [0.94] to 4.84 [0.55] to 5.02 [0.70], p = 0.00) and abdomen (5.25 [1.09], 4.91 [0.63], 5.12 [0.66], p = 0.00). TEWL at the forearm were (4.80 [2.95], 4.10 [2.15], 4.60 [3.40], p = 0.67), shins (3.80 [1.40], 3.50 [2.35], 4.00 [2.50], p = 0.91) and abdomen (3.70 [2.45], 4.10 [3.60], 3.40 [2.95], p = 0.80). SCORAD improved from 14.2 ± 9.1 to 10.9 ± 10.65 to 10.5 ± 11, p = 0.00. Reduction in pH was observed with both moisturizers while TEWL significantly improved with pH-modified moisturizer. pH-modified moisturizer resulted in greater pH, TEWL and SCORAD improvements however the differences were not significant from standard moisturizer. Study limitation: Skin hydration was not evaluated. Conclusion: Moisturization is beneficial for atopic dermatitis; use of physiologically compatible pH moisturizer is promising.

Histopathological changes in epithelium of hair follicles and acrosyringium caused by measles in child

Abstract Some epidermal alterations in measles has been described, such as keratinocytes apoptotic, parakeratosis, giant-cell formation, intranuclear and cytoplasmic inclusions, dyskeratosis, spongiosis, and intracellular edema. The authors report for the first time in human a case of measles with the presence of multinucleated giant cells in the hair follicle and dyskeratosis in acrosyringium.

In vivo and ex vivo dermoscopy of lesions from implantation of human papillomavirus in tattoos: report of two cases

Abstract The number of individuals with tattoos has been increasing worldwide, alongside with reports of complications varying from reactions to the injected pigments to infections caused by agents inoculated in the pigmentation process. The diagnosis of such unwanted events can be obtained through complementary non-invasive methods, preserving the maximum of the tattoo design. The authors present two cases of patients with warts on tattooing, and correlate their clinical aspects to in vivo and ex vivo dermoscopy, and to the findings in the histopathological examination, aiming to determine patterns that aid the diagnosis of these lesions without performing biopsy.

Dermatoscopy of the Borst-Jadassohn phenomenon in hidroacanthoma simplex

Abstract The Borst-Jadassohn phenomenon is a morphological finding that consists of the presence of well-defined nests of cells located in the spiny stratum of an acanthotic epidermis. One of the neoplasms where this phenomenon is found is hidroacanthoma simplex. This neoplasm is considered the intraepidermal form of the eccrine poroma. Despite its benign nature, malignant transformations are reported. The present article reports a case of hidroacanthoma simplex and discusses the dermoscopy of this phenomenon.

AQP5 regulates the proliferation and differentiation of epidermal stem cells in skin aging

The epidermis, the outermost layer of the skin, is the first barrier that comes into contact with the external environment. It plays an important role in resisting the invasion of harmful substances and microbial infections. The skin changes with age and external environmental factors. This study aimed to investigate epidermal stem cells during the process of aging. This study enrolled 9 volunteers with benign pigmented nevus for clinical dermatologic surgery. The phenotypes associated with skin aging changes such as skin wrinkles and elasticity of the unexposed/healthy parts near benign pigmented skin were measured, and epidermal stem cells from this region were isolated for transcriptome sequencing. The results showed that epidermal stem cells could be obtained by magnetic activated cell sorting (MACS) with high purity. Results of the transcriptome sequencing revealed that aquaporin (AQP)5 significantly decreased in the epidermal stem cells with age, and further functional experiments revealed that AQP5 could promote the proliferation and dedifferentiation of HaCaT, but did not influence cell apoptosis. In summary, AQP5 regulated the proliferation and differentiation of epidermal stem cells in skin aging, and it may play an important role in the balance of proliferation and differentiation. However, further studies are needed to determine the mechanism by which AQP5 regulates the proliferation and differentiation of epidermal skin cells in aging.

Exploratory Study of Epidermis, Basement Membrane Zone, Upper Dermis Alterations and Wnt Pathway Activation in Melasma Compared to Adjacent and Retroauricular Skin

BACKGROUND: Melasma is a chronic acquired focal hypermelanosis which pathogenesis has not been fully elucidated. Classical pathophysiologic studies have analysed the affected and perilesional areas, but little is known about the status of sun-protected skin, which is subjected to the same endogenous and genetic factors.OBJECTIVE: To assess the histological characteristics of melasma compared to adjacent and retroauricular skin.METHODS: Skin samples were collected from 10 female from: melasma, perilesional area and retroauricular. The samples were stained (haematoxylin-eosin, periodic acid-Schiff, Fontana-Masson, picrosirius red, toluidine blue and Verhoeff), immunolabelled for CD34 and Wnt1. The data from the skin sites were analysed simultaneously by a multivariate model.RESULTS: Melasma skin exhibited noteworthy stratum corneum compaction, greater collagen heterogeneity, solar elastosis, higher number of mast cells, basement membrane zone (BMZ) damage, Wnt1 expression, pendulum melanocytes, higher cellularity and vascular proliferation at the superficial dermis. Stratum corneum compaction, collagen heterogeneity and BMZ abnormalities were variables associated to melasma that not follow a continuum through retroauricular to adjacent skin. Mast cell count was the variable that disclosed correlation with the most other abnormalities as well as had the greater contribution in the multivariate model.CONCLUSION: In addition to melanocyte hyperactivity, melasma skin exhibits alterations in the epidermal barrier, upper dermis and BMZ, which differ from the adjacent sun-exposed skin and retroauricular skin, indicating a distinct phenotype, rather than a mere extension of photoageing or intrinsic ageing. Mast cells appear to play a central role in the physiopathology of melasma.

Epigenetic Regulation of Filaggrin Gene Expression in Human Epidermal Keratinocytes

BACKGROUND: Loss-of-function mutations in the filaggrin gene (FLG), which encodes an epidermal protein crucial for the formation of a functional skin barrier, have been identified as a major predisposing factor in the etiopathogenesis of atopic dermatitis (AD). Recent reports of relatively low frequencies of FLG-null mutations among specific ethnic groups with AD necessitated analysis of the epigenetic regulation which may control FLG expression without altering its DNA sequence.OBJECTIVE: The study aimed to identify DNA methylation-dependent regulation of FLG expression.METHODS: Quantitative polymerase chain reaction was performed to determine the restoration of FLG mRNA expression in normal human epidermal keratinocyte (NHEK) cells after treatment with epigenetic modulating agents. Bisulfite genomic sequencing and pyrosequencing analyses of the FLG promoter region were conducted to identify the citical CpG sites relevant to FLG expression. We performed small-scale pilot study for epidermal tissues obtained from Korean patients with severe AD.RESULTS: We here show that DNA methylation in the FLG with non-CpG island promoter is responsible for the transcriptional regulation of FLG in undifferentiated NHEK cells. The methylation frequencies in a single CpG site of the FLG promoter were significantly higher in lesional epidermis than those in matched nonlesional epidermis of subjects with severe AD.CONCLUSION: Our in vitro and clinical studies point to this unique CpG site as a potential DNA methylation marker of FLG, which can be a promising therapeutic target in the complications of filaggrin-related skin barrier dysfunction as well as in AD.

Eccrine Syringofibroadenoma Associated with Bowen's Disease: A Case Report and Review of the Literature

Diagnostic approach of eosinophilic spongiosis

Abstract Eosinophilic spongiosis is a histological feature shared by some distinct inflammatory disorders, and is characterized by the presence of intraepidermal eosinophils associated with spongiosis. Most often, isolated eosinophilic spongiosis indicates the early stages of a subjacent autoimmune bullous dermatosis, such as the pemphigus group and bullous pemphigoid. Herein, the main causes of eosinophilic spongiosis are discussed, as well as the supplementary investigation needed to elucidate its etiology.

Desenvolvimento de formulações cosméticas para animais de estimação: desafios e perspectivas / Cosmetic formulations development for pets: challenges and perspectives

O objetivo deste estudo foi uma breve revisão das características morfológicas e estruturais da pele e dos pelos de animais de estimação. Também foram abordadas regulamentações e conceitos fundamentais para elaboração de formulações cosméticas para o mercado pet. Para isso foram utilizadas base de dados Web of Science, Willey e Scielo, sendo consultados diversos periódicos e também livros de veterinária e dermatologia. Também foram consultados diversos jornais, revistas e associações relacionadas aos aspectos mercadológicos. Por fim, orgão regulamentadores brasileiros também foram consultados. São muitos os desafios na obtenção de produtos cosméticos seguros e eficazes para o mercados pet. As formulações cosméticas devem ser desenvolvidas especialmente para os animais considerandose as características da pele e seus anexos, bem como as formas cosméticas que proporcionem maior praticidade, eficácia e segurança. Não se pode deixar de considerar também a legislação que ainda incipiente permite a comercialização de produtos que podem até mesmo causar danos aos animais e aos seus donos e cuidadores. As perspectivas para o setor pet e para os cosméticos para animais são de franco crescimento com boas oportunidades de negócios. Desse modo, este artigo vem contribuir com este importante setor da economia pois pode auxiliar no desenvolvimento de produtos cosméticos de maior qualidade, segurança e valor agregado.

The aim of this study was a brief review of the morphological and structural characteristics of the skin and the fur of pets. In addition, fundamental regulations and concepts for elaborating cosmetic formulations for the pet market were discussed. Scientific databases, Web of Science, Wiley and Scielo were used for this purpose. It was consulted several periodic and also veterinary and dermatology books. Several newspapers, magazines and institutions related to the market aspects were also consulted. Finally, Brazilian regulatory agencies were also consulted. There are many challenges in obtaining safe and effective cosmetic products for the pet market. Cosmetic formulations should be developed especially for animals taking into account the characteristics of the skin and its appendages, as well as the cosmetic forms that provide greater practicality, effectiveness and safety. It is also important to consider the legislation that is still in the early stages of commercialization of products which may even cause harm to animals and their owners and caregivers. The perspectives for the pet and animal cosmetics industry are booming with good business opportunities. Thus, this article contributes to this important sector of the economy because it can help in the development of cosmetic products of higher quality, safety and greater value

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.