Gonadal differentiation during embryonic and fetal development of male New Zealand rabbits (Oryctolagus cuniculus) / Diferenciación gonadal durante el desarrollo embrionario y fetal de conejos machos neozelandeses (Oryctolagus cuniculus)

SUMMARY: The rabbit is considered an ideal animal model for studies that describe abnormalities in the testicles due to the similar morphogenetic mechanisms of sexual development and diseases commonly found in humans. The aim of this study was to determine the male sexual differentiation of the New Zealand rabbit (Oryctolagus cuniculus) through development. The gestational age was estimated and classified as 9, 12, 14, 16, 18, 20, 23 and 28 gestational days. The morphological and sexual determination were performed by histological analysis of the reproductive tract in the embryos and fetuses (9-28 days) as well as by immunohistochemistry- Desert hedgehog-Dhh- (testis-specific protein on Y chromosome- 16, 20, 23 days and adult rabbits). Gonads were observed from the 14th day in an undifferentiated stage and with homogeneous aspect. Sexual differentiation was observed from the 16th day with presence of cells forming gonadal cords and Dhh+ cells in the gonadal parenchyma. From the 18th gestational day testicular cords were observed, which evolved into organized seminiferous tubules. The formation of the efferent ducts and ductus deferens and epididymis was observed on the 20th and 23rd days, respectively. The differentiation of the external genitalia occurred from the 23rd days from the anogenital distance and was identified to identify the penile structures. In summary, the features of the sexual differentiation were determined by observation of the Dhh+ protein in embryos from the 16th day to adulthood, and the morphological particularities observed from the 18th gestational day, determined by differentiation of the external genitalia from the 23rd day.

RESUMEN: El conejo se considera un modelo animal ideal para estudios que describen anomalías a nivel testícular debido a que presenta mecanismos morfogenéticos similares al desa- rrollo sexual y enfermedades que se encuentran comúnmente en los seres humanos. El objetivo de este estudio fue determinar la diferenciación sexual masculina del conejo de Nueva Zelanda (Oryctolagus cuniculus) a través del desarrollo. La edad gestacional se estimó y clasificó en 9, 12, 14, 16, 18, 20, 23 y 28 días gestacionales. La determinación morfológica y sexual se realizó mediante análisis histológico del tracto reproductivo en los embriones y fetos (9 - 28 días) así como mediante inmunohistoquímica -Desert hedgehog-Dhh- (proteína testicular específica en el cromosoma Y- 16, 20, 23 días y conejos adultos). Las gónadas se observaron a partir del día 14 en un estadio indiferenciado y con aspecto homogéneo. Se observó diferenciación sexual a partir del día 16 con presencia de células formadoras de cordones gonadales y células Dhh+ en el parénquima gonadal. A partir del día 18 de gestación se observaron cordones testiculares, que evolucionaron a túbulos seminíferos organizados. La formación de los conductos eferentes, deferentes y del epidídimo se observó a los 20 y 23 días, respectivamente. La diferenciación de los genitales externos ocurrió a partir del día 23 desde la distancia anogenital y se utilizó para identificar las estructuras del pene. En conclusión, las características de la diferenciación sexual se determinaron mediante la observación de la proteína Dhh en embriones desde el día 16 hasta la edad adulta, y las particularidades morfológicas observadas a partir del día 18 de gestación, determinadas por diferenciación de los genitales externos a partir del día 23.

Decellularization of Extracellular Matrix from Equine Skeletal Muscle.

Equine represents an attractive animal model for musculoskeletal tissue diseases, exhibiting much similarity to the injuries that occur in humans. Cell therapy and tissue bioengineering have been widely used as a therapeutic alternative by regenerative medicine in musculoskeletal diseases. Thus, the aim of this study was to produce an acellular biomaterial of equine skeletal muscle and to evaluate its effectiveness in supporting the in vitro culture of equine induced pluripotency stem cells (iPSCs). Biceps femoris samples were frozen at -20°C for 4 days and incubated in 1% sodium dodecyl sulfate (SDS), 5 mM EDTA + 50 mM Tris and 1% Triton X-100; the effectiveness of the decellularization was evaluated by the absence of remnant nuclei (histological and 4',6-diamidino-2-phenylindole [DAPI] analysis), preservation of extracellular matrix (ECM) proteins (immunofluorescence and immunohistochemistry) and organization of ECM ultrastructure (scanning electron microscopy). Decellularized samples were recellularized with iPSCs at the concentration of 50,000 cells/cm2 and cultured in vitro for 9 days, and the presence of the cells in the biomaterial was evaluated by histological analysis and presence of nuclei. Decellularized biomaterial showed absence of remnant nuclei and muscle fibers, as well as the preservation of ECM architecture, vascular network and proteins, laminin, fibronectin, elastin, collagen III and IV. After cellularization, iPSC nuclei were present at 9 days after incubation, indicating the decellularized biomaterial-supported iPSC survival. It is concluded that the ECM biomaterial produced from the decellularized equine skeletal muscle has potential for iPSC adhesion, representing a promising biomaterial for regenerative medicine in the therapy of musculoskeletal diseases.

The sphenoidal emissary foramen and the emissary vein: Anatomy and clinical relevance.

Although the sphenoidal emissary foramen (SEF) and its content are anatomically and clinically relevant, accurate description of them in the modern literature is lacking. This study aimed to examine and describe the SEF and its content (the sphenoidal emissary vein [SEV]). We analyzed 1,000 computed tomography (CT) images, 170 dry skulls, 50 formalin-fixed specimens, and three specimens (heads) following guidelines proposed by Dr. Albert L. Rhoton Jr. MD for latex injection. SEV morphology was determined by histological staining and electron microscopy. The SEF was observed in 46.8% of the CTs studied (25.4% bilateral and 21.4% unilateral), and 45.2% of the dry skulls (18.8% bilateral and 26.4% unilateral). In 9.5% of CTs and 21.1% of dry skulls there was a blind channel in the external surface of the cranial base; since there was no communication with the cranial cavity, it was not considered as the SEF. During the dissections, the SEF was found in seven individuals. In three of them, the SEV was an alternative route for venous drainage of the venous plexus of the foramen ovale. Its walls were composed of collagen fibers and its endothelium contained rhomboid cells resembling those commonly found in the superior sagittal sinus. The presence of the SEF and SEV can anatomically explain the spread of certain cranial base pathologies from or toward Meckel's cave or the cavernous sinus, and should be taken into account during procedures in the middle cranial fossa, percutaneous approaches, odontological procedures, and treatment of dural arteriovenous fistulas. Clin. Anat., 33:767-781, 2020. © 2019 Wiley Periodicals, Inc.

Topographic and microscopic anatomical description of the emissary sinus of foramen ovale in adult humans.

OBJECTIVE: Although the Emissary Sinus of Foramen Ovale (ESFO) was first described by Trolard in 1868, its definition remains confused and neglected in the medical literature. This structure represents a vein, two veins, a venous plexus, or a dural sinus? Does it really exist? To understand this topic, this work aimed to describe the anatomy, topography, and microscopic features of the ESFO, precisely characterizing its structure, routes and anatomical correlations. PATIENTS AND METHODS: ESFO from the skull's base of adults were dissected into fifty anatomical blocks and evaluated using Hematoxylin and Eosin, Picro-sirius red and Weigert staining, and by Scanning Electron Microscopy (SEM). RESULTS: ESFO was always present between cavernous sinus and pterygoid plexus on both antimeres, its inferior route passing through the foramen ovale and/or sphenoidal emissary foramen (foramen of Vesalius), anterior to the mandibular branch of trigeminal nerve. Its microscopic arrangement resembled what was found on transverse sinus, that is composed by layers of collagen fibers oriented on transversal and longitudinal planes. It wasn't possible to identify the media and adventitial tunica, features seen in veins, and the elastic layer was very thin near its lumen. SEM analysis showed that, like the transverse sinus, the ESFO was composed by parallel cells that presented a rhombus shape containing central rounded nuclei. CONCLUSION: In summary, the venous channel passing through the foramen ovale and/or sphenoidal emissary foramen (foramen of Vesalius) is a dural venous sinus constituted by dura mater layers and should be considered during surgical approaches near the foramen ovale in the middle cranial fossa.

Estudo descritivo comparativo da anatomia do músculo tensor da fáscia lata em macaco prego (Sapajus apella) e canídeos neotropicais / Comparative anatomy of the fascia lata tensor muscle in capuchin monkeys (Sapajus apella) and neotropical canides

A Anatomia comparativa vem se destacando nos tempos, como recurso que permite a avaliação da evolução de determinadas espécies, evidenciando suas adaptações ao meio em que vive. Com a intervenção humana, no bioma do cerrado diversas espécies entraram ou se encontram em vias de entrarem em risco de extinção sem nem ao menos terem a sua biologia estudada. Este trabalho visa descrever e comparar a anatomia do músculo tensor da fáscia lata de macaco-prego e canídeos neotropicais. Para tanto, foram utilizados dois espécimes de cada grupo taxonômico: macacoprego; raposa-do-campo; cachorro-do-mato e lobo-guará, comparando os resultados encontrados entre si, com a literatura humana e veterinária já bem estabelecidas. Os animais foram fixados em solução aquosa de formol a 10%, e dissecados sob técnicas usuais de dissecação utilizadas em Anatomia macroscópica, seguido de foto documentação. O músculo tensor da fáscia lata não apresenta divergências entre as espécies estudadas, possuindo formato aproximadamente triangular e localização na parte proximal da face lateral da coxa, constituído por uma parte cranial e outra caudal. As principais diferenças estão relacionadas, com o porte físico-postural de cada grupo, certamente atrelado ao modo de vida.

The comparative anatomy has been assuming an important role during the last decades as a tool that allows evaluatingthe evolution of certain species, showing their adaptations to the environment they live in. Due to human intervention in the cerrado biome, several species have been or are about to be endangered without even having their biology studied. This study aimed to describe and compare the anatomy of the Fascia Lata Tensor muscle in capuchin monkeys and neotropical canides. For such purpose, two specimens of each taxonomic group (capuchin monkey, field fox; forest dog and maned wolf) were used. The obtained results were compared among the studied species and discussed with the human and veterinary literature data, which are already well established. As the focus of this study was on the descriptive anatomy rather than on the statistical data, the dissection of a larger number of animals was not required. The pieces were fixed in 10% formalin aqueous solution, using dissection routine techniques in macroscopic anatomy. Next, the pieces were analyzed, described and photographed. Regarding the shape and location the fasciae latae tensor muscle presented no major differences, having an approximately triangular shape, locating in the proximal part of the thigh lateral side and comprising a cranial portion and another caudal one, both fleshy. The main differences were related to the postural-physical size of each group, certainly linked to the lifestyle.

Grupo operativo como estratégia para acompanhamento do Projeto Pedagógico de Curso em Enfermagem / Operating group as a follow-up strategy of a Nursing Course’s Pedagogical Project

O objetivo do estudo foi acompanhar e descrever o processo de implantação do Projeto Pedagógico do Curso de Graduação em Enfermagem do Campus Catalão da Universidade Federal de Goiás, sob a ótica de docentes e discentes. Tratou-se de estudo qualitativo e descritivo, realizado com treze participantes entre docentes e discentes, de abril de 2010 a junho de 2011, em Catalão, GO, Brasil. Utilizou-se o grupo operativo como tecnologia para acompanhamento e coleta de dados. Ao final de cada reunião foi constituída uma crônica, submetida à análise de conteúdo temática, de onde emergiram duas categorias, que revelaram como potencialidade do processo ensino-aprendizagem a interdisciplinaridade da matriz curricular, e como limitadores a imaturidade dos estudantes e a relação interpessoal conflituosa entre acadêmicos e docentes. O trabalho em pequenos grupos demonstrou-se importante ferramenta pedagógica; o grupo operativo mostrou-se assertivo na gestão do ensino e na condução da pesquisa.