Morfologia do estômago e do duodeno da paca (Cuniculus paca Linnaeus, 1766) / Morphology of the stomach and duodenum of paca (Cuniculus paca Linnaeus, 1766)

Considerando a importância da paca (Cuniculus paca, Linnaeus, 1766), tanto como fonte proteica alternativa para a população quanto pela possibilidade de vir a se tornar um animal de experimentação e pela falta de informações sobre a sua anatomia, objetivou-se descrever a morfologia macroscópica e histológica do estômago e do duodeno desse roedor, reconhecendo as relações, forma e posição que esses órgãos estabelecem entre si e com outros órgãos. O estômago da paca é unicavitário, está no plano médio mais voltado para o antímero esquerdo, transversalmente, na região hipocôndrica em posição ventrocaudal, interposto entre o esôfago e o duodeno. O duodeno da paca se inicia em sequência ao estômago, segue caudalmente até o nível da quinta ou sexta vértebra lombar, na altura das quais se curva e toma direção cranial, dirigindo-se até o nível da transição entre a última vértebra torácica e a primeira vértebra lombar, onde se continua como jejuno. Histologicamente, o estômago e o duodeno da paca possuem o padrão característico da arquitetura dos órgãos ocos, apresentando as seguintes túnicas: mucosa, submucosa, muscular e serosa. Da forma que se conduziu este estudo, conclui-se que o estômago e duodeno da paca, de forma geral, possuem características morfológicas macroscópicas e histológicas semelhantes às dos animais domésticos e de outros roedores selvagens.

Considering the importance of paca (Cuniculus paca, Linnaeus, 1766) as an alternative protein source for the population as well as the possibility to become an experimental model and the lack of information regarding to the anatomy of this species, the present study aims to describe the gross anatomy and the histology of the stomach and duodenum of this rodent, recognizing the relations, shape and position that these organs establish between themselves and among other organs. The paca stomach is monocavitary; it is located at the median plane, more toward the left antimere, transversally, at the hypochondriac region in a ventrocaudal position, interposed between the esophagus and duodenum. The duodenum of paca begins in sequence of the stomach, following caudally until the fifth or sixth lumbar vertebra, at this level it curves and takes the cranial direction, going until the transition level between the last thoracic vertebra and the first lumbar vertebra where it continues as jejune. Histologically, the stomach and duodenum of paca have the characteristic pattern of the hollow organs architecture, presenting the following layers: mucosa, submucosa, muscular and serous. As this study was conducted, it is possible to conclude that the stomach and duodenum of paca, in general, present gross anatomical and histological characteristics similar to the domestic animals and to the other wild rodents.

Characterization of novel akermanite:poly-ϵ-caprolactone scaffolds for human adipose-derived stem cells bone tissue engineering.

In this study, three different akermanite:poly-ϵ-caprolactone (PCL) composite scaffolds (wt%: 75:25, 50:50, 25:75) were characterized in terms of structure, compression strength, degradation rate and in vitro biocompatibility to human adipose-derived stem cells (hASC). Pure ceramic scaffolds [CellCeram™, custom-made, 40:60 wt%; ß-tricalcium phosphate (ß-TCP):hydroxyapatite (HA); and akermanite] and PCL scaffolds served as experimental controls. Compared to ceramic scaffolds, the authors hypothesized that optimal akermanite:PCL composites would have improved compression strength and comparable biocompatibility to hASC. Electron microscopy analysis revealed that PCL-containing scaffolds had the highest porosity but CellCeram™ had the greatest pore size. In general, compression strength in PCL-containing scaffolds was greater than in ceramic scaffolds. PCL-containing scaffolds were also more stable in culture than ceramic scaffolds. Nonetheless, mass losses after 21 days were observed in all scaffold types. Reduced hASC metabolic activity and increased cell detachment were observed after acute exposure to akermanite:PCL extracts (wt%: 75:25, 50:50). Among the PCL-containing scaffolds, hASC cultured for 21 days on akermanite:PCL (wt%: 75:25) discs displayed the highest viability, increased expression of osteogenic markers (alkaline phosphatase and osteocalcin) and lowest IL-6 expression. Together, the results indicate that akermanite:PCL composites may have appropriate mechanical and biocompatibility properties for use as bone tissue scaffolds.