RESUMO: Os anéis de ossículos esclerais têm sua função relacionada à proteção mecânica, fixação muscular, suporte para o formato do bulbo ocular e acomodação visual, contudo existem poucos relatos morfobiométricos sobre esses anéis em diferentes espécies de Testudines. Desta forma, foi realizada a avaliação morfobiométrica, por ultrassom (US) e tomografia computadorizada (TC), dos anéis de ossículos esclerais em uma tartaruga verde (Chelonia mydas), um tigre-d’água (Trachemys dorbigni) e um jabuti-piranga (Chelonoidis carbonarius). Foram realizadas US e TC dos anéis esclerais dos três animais para identificação anatômica, espessura, densidade, largura e diâmetros. A US e a TC dos três animais mostraram estruturas circulares únicas e contínuas, localizadas no polo anterior. Estas estruturas foram facilmente observadas na C. mydas, cujos anéis eram os maiores, mais espessos e mais largos. A TC da T. dorbigni apresentou dimensões reduzidas e os ossículos foram dificilmente identificados. A densidade óssea na região superior foi maior comparativamente a parte inferior de cada anel, em todos os animais. Exames de imagem não invasivos mostraram-se bons instrumentos para estudo do esqueleto escleral. Os anéis de ossículos esclerais dos três espécimes apresentaram semelhanças morfológicas gerais e a TC permitiu visualizar um maior número de detalhes da morfologia óssea do anel.

ABSTRACT: The scleral ossicle rings function has been related to mechanical protection, muscle fixation, support for eyeball shape and visual accommodation. There are few morphobiometric reports on these rings in different Testudines species, and we performed ultrasound (US) and computed tomography (CT) of the scleral ossicle rings in one green turtle (Chelonia mydas), one black-bellied slider (Trachemys dorbigni) and one red-footed tortoise (Chelonoidis carbonarius). The US and CT of the ossicle rings were performed for anatomical identification. The thickness, density, width, and diameters of each ring were measured. The US and CT of the scleral ossicle rings of three animals showed single and continuous circular structures, located in the anterior pole. These structures were easily observed in C. mydas, whose rings were the biggest, thickest and widest. The T. dorbigni CT presented decreased dimensions and the ossicles were the most difficult to identify. Bone density in the superior region was greater than in the inferior of each ring in all animals. Non-invasive imaging exams are good tools to study the anatomy of the ocular skeleton. The scleral ossicle rings of the three specimens presented general morphological similarities and CT enabled visualizing a greater number of details of the ring bone morphology.

Rats and mice are among the most susceptible hosts for the helminth Capillaria hepatica. More information on the similarities and differences between the hepatic pathology presented by these two parasite hosts are needed, since they may represent good models for the study of hepatic fibrosis. Early changes are similar for both hosts and are represented by necro-inflammatory lesions around dead parasites and their eggs and diffuse and intense reactive hepatitis. Although worms remain alive longer in mice than in rats, hepatic changes are more rapidly and deeply modulated in the former, even leading to almost complete disappearance of fibrosis. As for the rats, the modulation of the focal lesions is followed by the formation of septal fibrosis, a process where fine and long fibrous septa appear connecting portal spaces and central veins in such a way as to form a final morphologic picture of cirrhosis. Hepatic functional changes usually present good correlations with the morphologic findings at the different phases of the infection evolution. Therefore C. hepatica infection in rats and mice represent two different models of hepatic fibrosis and these differences, if properly known and understood, can be explored to answer different questions regarding several aspects of hepatic fibrosis