Morphology and computed tomography of the larynx in the white-eared opossum (Didelphis albiventris).

The white-eared opossum (Didelphis albiventris) is a Neotropical marsupial that occurs in the Brazilian territory. The larynx is an important organ of vocalization in mammals, although, other laryngeal functions are more fundamental for survival of mammals than phonation. The anatomical knowledge of respiratory structures is pivotal for a better understanding of the species. Thus, this study aimed to examine the larynx of the white-eared opossum by gross anatomy, computed tomography and histological description. For this, 10 adult (six females and four males) white-eared opossums (D. albiventris) were used. The white-eared opossum larynx was formed by epiglottis, thyroid, cricoids and arytenoid cartilages and a corniculate process. There is a similarity between the larynx of this marsupial and those reported in other wild mammals, regarding the number of cartilages and their location. Histologically, the epiglottis consisted of elastic cartilage and thyroid, cricoid and arytenoid cartilages were composed of hyaline cartilage. The epiglottis protruded rostrally into the nasal part of the pharynx, above the soft palate, and this is probably a marsupial characteristic as the fact that the thyroid and cricoid cartilages were ventrally fused. The hyoid apparatus was similar to that of other animals, with the same bony constitution, but with a greatly reduced stylohyoid bone. Histologically, the larynx was similar to those of other species such as koala, armadillo, crab-eating foxes and giant anteaters. The knowledge of the larynx morphology is important for the anatomical features of the species and clinical and surgical procedures, such as endotracheal intubation.

Effect of low-level laser therapy on the membrane induced by the Masquelet technique at an orthotopic site in rabbits.

PURPOSE: To evaluate the low-level laser therapy (LLLT) on the membrane induced by the Masquelet technique in rabbits. METHODS: Twelve Norfolk rabbits at approximately 3 months of age were used. A 1-cm segmental defect was induced in both radii, which were filled with polymethylmethacrylate cylinder. LLLT was used postoperatively in the bone defect of one of the forelimbs every 48 hours for 15 days. Six rabbits were euthanatized on third and sixth postoperative weeks. RESULTS: In both forelimbs, radiographs showed new bone growth from radius cut ends on the third postoperative week and more advanced stage on the sixth postoperative week. Ultrasound showed induced membrane one week after the surgery. Histologically, there were no significant differences in the semi-quantitative score of inflammation intensity, total number of blood vessels, bone metaplasia, and collagen. The average thicknesses were 2,050.17 and 1,451.96 µm for control membranes and 2,724.26 and 2,081.03 µm for irradiated membranes, respectively, on third and sixth postoperative weeks. Vascular endothelial growth factor A (VEGF-A) and platelet derived growth factor (PDGF) expression were present in the induced membranes of control and irradiated forelimbs, but there was no significant difference. CONCLUSIONS: Based on assessment methods, it was not possible to demonstrate the effect of LLLT on the induced membrane.

Osteology and radiology of the vertebral column in the white-eared opossum (Didelphis albiventris).

The white-eared opossum present a higher roadkill number in Brazil, and the vertebral column is often affected when some type of trauma occurs. Thus, this study describes the osteology and radiology of the vertebral column in white-eared opossum to serve as a basis for support in the veterinary clinical care, since the casuistry of care of this marsupial has increased every year. Radiographs of the cervical (C), thoracic (T), lumbar (L), sacral (S) and caudal (Cd) segments of the vertebral column were taken in thirty-five white-eared opossums (Didelphis albiventris). Furthermore, ten opossums without evident vertebral acquired or congenital abnormalities at the radiographic study were selected for anatomical study. Osteology was correlated with the radiographic images. The use of radiographs allowed the identification of congenital and acquired vertebral changes, as well as the identification of anatomical structures, their distribution and morphology and the number of vertebrae. The vertebral formula varied in the white-eared opossum. In 27 of 35 white-eared opossums (77.2%) with normal vertebral morphology, three vertebral formulas were observed: C7/T13/L6/S2 (62.9%), C7/T13/L5/S2 (5.7%) and C7/T13/L7/S2 (8.6%). Most of the specimens presented 27 caudal vertebrae. The anticlinal vertebra was identified as T10 in 77.2% and T11 in 22.8% of opossums. Cervical block vertebra was observed in two animals and sacrocaudal block vertebra in one animal. The haemal arches could be seen from Cd3-Cd4 in 80% and Cd2-Cd3 in 20% of opossums. The white-eared opossum showed a slender vertebral column with a relatively short thoracic region, a relatively long lumbar region and a highly flexible lumbosacral transition, suggesting that this animal is a fast-running and agile opossum. Therefore, these findings may serve as a basis for further research and support the veterinary clinical care, since the casuistry of care for this marsupial has increased every year.

Effect of low-level laser therapy on the membrane induced by the Masquelet technique at an orthotopic site in rabbits

ABSTRACT Purpose: To evaluate the low-level laser therapy (LLLT) on the membrane induced by the Masquelet technique in rabbits. Methods: Twelve Norfolk rabbits at approximately 3 months of age were used. A 1-cm segmental defect was induced in both radii, which were filled with polymethylmethacrylate cylinder. LLLT was used postoperatively in the bone defect of one of the forelimbs every 48 hours for 15 days. Six rabbits were euthanatized on third and sixth postoperative weeks. Results: In both forelimbs, radiographs showed new bone growth from radius cut ends on the third postoperative week and more advanced stage on the sixth postoperative week. Ultrasound showed induced membrane one week after the surgery. Histologically, there were no significant differences in the semi-quantitative score of inflammation intensity, total number of blood vessels, bone metaplasia, and collagen. The average thicknesses were 2,050.17 and 1,451.96 μm for control membranes and 2,724.26 and 2,081.03 μm for irradiated membranes, respectively, on third and sixth postoperative weeks. Vascular endothelial growth factor A (VEGF-A) and platelet derived growth factor (PDGF) expression were present in the induced membranes of control and irradiated forelimbs, but there was no significant difference. Conclusions: Based on assessment methods, it was not possible to demonstrate the effect of LLLT on the induced membrane.

Anatomy of the skull in the capybara (Hydrochoerus hydrochaeris) using radiography and 3D computed tomography.

The capybaras (Hydrochoerus hydrochaeris) are the largest rodent found throughout South America and are present in almost all the Brazilian territory, however, still lack basic descriptions about the species, such as about their cranial anatomy. This study was carried out to investigate the anatomical features in the capybara skull. Eight skulls and two heads, without sexual distinction, were used for the osteological, radiographic and tomographic identification of their structures. The skull of the capybara could be divided into a neurocranium and a viscerocranium. The capybara had a more robust and rectangular skull, elongated face caudally, thinned in the nasal region and slightly convex in the parietal region. The zygomatic arch was expanded and wide, the orbit had a circular shape, the infraorbital foramen was well developed, external acoustic meatus and tympanic bulla were relatively small, and the paracondylar process was large. These anatomical characteristics are compatible with the eating habit and semi-aquatic life of capybaras, which can be compared with characteristics reported for animals of similar habits. The radiographic image allowed to identify structures such as the frontal sinus, whereas 3D tomographic reconstruction was essential to have a spatial view of the skull of the capybara.