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In this study, we aimed to evaluate the efficacy of cryopreserving canine ovarian tissue using vitrification and slow freezing methods while investigating potential differences in cryotolerance based on follicular type and cryopreservation technique. Twenty-eight ovaries were collected from 14 anoestrus bitches of various breeds, aged between 2 and 5 years, and undergoing elective ovariohysterectomy. The ovaries were sectioned into small fragments and randomly assigned to three groups: vitrification, slow freezing, and a control group (fresh tissue). Vitrification was performed using cryotubes containing DAP 213 solution (2M DMSO, 1M acetamide, 3M propylene glycol) in two stages, while slow freezing involved cryotubes with 1.5M DMSO solution inserted into a programmable machine. The effects of cryopreservation were evaluated by histology and immunohistochemistry (cleaved caspase-3), to determine the percentage of cells undergoing apoptosis. Histological examination revealed that the slow freezing group exhibited a significantly higher percentage of intact follicles (45.75 %) compared to those subjected to vitrification (38.17 %; P = 0.01). Immunohistochemical evaluation further indicated that 84.21 % of the follicles in the slow freezing group did not express caspase-3, suggesting the absence of apoptosis. Conversely, vitrified samples exhibited significantly more apoptotic cells compared to other groups (P < 0.001). Furthermore, early antral follicles displayed a higher susceptibility to degeneration regardless of the cryopreservation method employed. Nevertheless, when comparing the cryopreserved groups, early antral follicles showed greater degeneration in slow freezing group, while preantral follicles were the most affected in the vitrification group. In conclusion, slow freezing demonstrated superior preservation of viable follicles compared to vitrification and emerged as the preferred technique for cryopreserving canine ovarian tissue. These findings contribute valuable insights into optimizing cryopreservation methods for canine ovarian tissue, potentially benefiting reproductive technologies and fertility preservation in canines.

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Um repositório de amostras biológicas, ou biobanco, pode ser definido como uma coleção-base de amostras orgânicas de origem humana, animal, vegetal ou microbiana, destinados para a conservação da ampla variabilidade dos recursos genéticos, apresentando-se como uma alternativa para a manutenção da biodiversidade. Esses repositórios são instrumentos indispensáveis no proposito de salvaguardar e coordenar um conjunto de informações da fauna silvestre, dando origem a uma rede de dados para o desenvolvimento de estratégias para a conservação de espécimes com genótipos raros ou ameaçados. Portanto, esta revisão tem como objetivo ressaltar a importância e aplicabilidade dos biobancos para a conservação da vida silvestre, destacando o estado da arte, e enfatizando os aspectos técnicos, procedimentos necessários para sua implementação e quais os principais desafios e pespectivas para o aprimoramento e utilização desse recurso na biotecnologia reprodutiva.(AU)

A repository of biological samples or biobanks can be defined as a base collection of organic samples of human, animal, plant or microbial origin, intended for the conservation of the wide variability of genetic resources, presenting itself as an alternative for the maintenance of the biodiversity. These repositories are indispensable instruments for the purpose of safeguarding and coordinating a set of information on wildlife, giving rise to a data network for the development of strategies for the conservation of specimens with rare or endangered genotypes. Therefore, this review aims to highlight the importance and applicability of biobanks for the conservation of wildlife, highlighting the state of the art, and emphasizing the technical aspects, as well as the necessary procedures for its implementation and what are the main challenges and perspectives for the improvement and use of this resource in reproductive biotechnology.(AU)

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A reprodução assistida se faz necessária em programas de conservação de espécies ameaçadas de extinção, sendo um facilitador de transporte e troca de material genético. Neste contexto, o acesso ao material de animais de vida livre é essencial para incrementar o banco genético da espécie em questão, no entanto adaptar os métodos possíveis à realidade do campo torna essa área de pesquisa desafiadora. Ainda hoje os espermatozoides são os gametas mais acessados em animais de vida livre, porém com pouco uso efetivo para criopreservação e produção de filhotes. É pungente a necessidade de mais pesquisas nesta área, uma vez que há centenas de espécies brasileiras ameaçadas, com especificidades fisiológicas e que habitam habitats variados, o que demanda adaptações espécie-específicas e hábitat específicas.

Assisted reproduction is necessary for conservation programs for endangered species, facilitating transport and exchange of genetic material. In this context, access to material from free-living animals is essential to increase the genetic bank of the species in question. However, adapting the possible methods to the reality of the fieldwork makes this area of research a challenge. Even today, sperm are the most accessed gametes in free-living animals, but with little effective use for cryopreservation and production of offspring. The need for more research in this area is acute, as there are hundreds of Brazilian species under threat, with physiological specificities, and that inhabit varied habitats, which demand species-specific adaptations and specific habitats.

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RESUMEN Los tumores de células germinales no son tan frecuentes, dentro de ellos se encuentra el teratoma como el más usual en ubicación mediastinal, es más habitual en hombres jóvenes cuando es maligno (teratocarcinoma), con una relación por género de 13,5:1, y una edad promedio de 26 años. Se describe la evolución de un hombre de 19 años de edad con un tumor mediastinal, con metástasis pulmonares e infiltración intracardíaca, resecado satisfactoriamente, cuyos síntomas más frecuentes fueron: disnea, dolor retroesternal, fiebre, tos, pérdida de peso y síndrome de vena cava superior. El diagnóstico se realizó por radiografía de tórax y tomografía axial computarizada. Se logró realizar la excéresis total del tumor y las metástasis, así como la tumoración intracardíaca, con reparación de la válvula tricúspide. El paciente ha tenido una evolución satisfactoria durante el primer año de seguimiento.

ABSTRACT Germ cell tumors are not so frequent; among them, teratomas are most common in the mediastinal location. Teratomas in young men are usually malignant (teratocarcinoma), with a gender ratio of 13.5:1, and an average age of 26 years. We describe the evolution of a 19-year-old man with a mediastinal tumor, with pulmonary metastases and intracardiac infiltration, successfully removed; whose most frequent symptoms were: dyspnea, retrosternal pain, fever, cough, weight loss and superior vena cava syndrome. The diagnosis was made by chest x-ray and computed tomography. Total removal of the tumor and metastases was achieved, as well as the intracardiac tumor, with tricuspid valve repair. The patient had a satisfactory outcome during the first follow-up year.

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This study records the occurrence of a hermaphrodite individual of the apapá Pellona flavipinnis captured in a floodplain area of the Amazon River. Histology of the left gonad revealed the presence of testicular germ cells (spermatocytes and spermatozoa) in the cranial portion and mature ovarian cells (primary and vitellogenic oocytes) in the caudal portion, separated by connective tissue. This is the first record of a hermaphrodite fish of the family Pristigasteridae, order Clupeiformes.

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