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The egg is one of the fundamental parts of the life cycle of Neoechinorhynchus buttnerae, and this stage involves the acanthor larva. It is also the infection phase for the intermediate host. Under normal conditions, the larva inside the egg can survive for months in the environment; however, information regarding this phase of life of the parasite is scarce. In addition, there is no quantitative information about the structural composition of the parasite's body from a histological point of view. Such information is essential in order to support decisions aimed at controlling infestations by these parasites in fish farming. This study aimed to present a detailed description of the stages of embryonic development of N. buttnerae eggs, as well as a stereological evaluation of the body of adult females of the parasite. Three phases of development characterized the eggs: cell division (with four stages), formation of the internal nuclear mass (with four stages) and formation of the acanthor larva (with five stages). The ovary comprised 26.61% of the volume of the animal and most of it contained eggs (21.28%), ovarian balls (3.88%) and empty spaces (1.45%). These results are of great importance and will support future studies that seek to interrupt the life cycle of this parasite.

The egg is one of the fundamental parts of the life cycle of Neoechinorhynchus buttnerae, and this stage involves the acanthor larva. It is also the infection phase for the intermediate host. Under normal conditions, the larva inside the egg can survive for months in the environment; however, information regarding this phase of life of the parasite is scarce. In addition, there is no quantitative information about the structural composition of the parasite's body from a histological point of view. Such information is essential in order to support decisions aimed at controlling infestations by these parasites in fish farming. This study aimed to present a detailed description of the stages of embryonic development of N. buttnerae eggs, as well as a stereological evaluation of the body of adult females of the parasite. Three phases of development characterized the eggs: cell division (with four stages), formation of the internal nuclear mass (with four stages) and formation of the acanthor larva (with five stages). The ovary comprised 26.61% of the volume of the animal and most of it contained eggs (21.28%), ovarian balls (3.88%) and empty spaces (1.45%). These results are of great importance and will support future studies that seek to interrupt the life cycle of this parasite.

Sex steroid hormones are critical in gonadal differentiation in turtles. The gonads are not the only organs responsible for producing these hormones during this phase. Mesonephros play an important role in steroidogenesis. The present study aimed to investigate the presence of steroidogenic cells in mesonephros of

INTRODUCTION: Electron microscopy (EM) is a rapid and effective tool that can be used to create images of a whole spectrum of virus-host interactions and, as such, has long been used in the discovery and description of viral mechanisms. METHODS: Electron microscopy was used to evaluate the pulmonary pathologies of postmortem lung sections from three patients who died from infection with SARS-associated coronavirus 2 (SARS-CoV-2), a new member of the Coronaviridae family. RESULTS: Diffuse alveolar damage (DAD) was predominant in all three patients. The early exudative stage was characterized principally by edema and extravasation of red blood cells into the alveolar space with injury to the alveolar epithelial cells; this was followed by detachment, apoptosis, and necrosis of type I and II pneumocytes. The capillaries exhibited congestion, exposure of the basement membrane from denuded endothelial cells, platelet adhesion, fibrin thrombi, and rupture of the capillary walls. The proliferative stage was characterized by pronounced proliferation of type II alveolar pneumocytes and multinucleated giant cells. The cytopathic effect of SARS-CoV-2 was observed both in degenerated type II pneumocytes and freely circulating in the alveoli, with components from virions, macrophages, lymphocytes, and cellular debris. CONCLUSIONS: Viral particles consistent with the characteristics of SARS-CoV-2 were observed mainly in degenerated pneumocytes, in the endothelium, or freely circulating in the alveoli. In the final stage of illness, the alveolar spaces were replaced by fibrosis.

Made available in DSpace on 2016-09-23T15:19:52Z (GMT). No. of bitstreams: 1 RELATORIO_FINAL_-_PIBIC_-_0046.pdf: 713278 bytes, checksum: adc75015e92a31ffbf805b7db0ae8f73 (MD5) Previous issue date: 2012-07-31 FAPEAM Durante o cultivo intensivo de peixes, desequilíbrios nos processos de transformação da amônia podem acarretar elevados níveis de nitrito (NO2-) no meio aquático, o nitrito logo é absorvido através das brânquias que em poucas horas acumula-se no sangue e tecidos dos animais, e a concentração chega a ser muito superior da encontrada no ambiente. Das consequências devido a intoxicação pelo nitrito, pode se ressaltar duas: a primeira se da à direta ação do NO2- sobre a molécula da hemoglobina (Hb) transformando-a em metahemoglobina (MetHB) onde a mesma torna-se incapaz de de ligar e liberar oxigênio O2 aos tecidos. A partir disso alguns órgãos vitais para a homeostase enfrentam períodos de severa hipóxia devido a exposição ao nitrito. Dentre esses órgãos destaca-se o fígado, mas embora a espécie do tambaqui ser amplamente utilizada em meios de aquacultura, não se tem informações a respeito dos efeitos tóxicos do nitrito sobre a organização hepática do tambaqui. O presente projeto tem a finalidade de fazer uma análise morfométrica do fígado de tambaqui submetidos à exposição por nitrito, para se poder ter mais informações sobre a histologia quantitativa desta espécie.