Comparative macroanatomical and scanning electron microscopy study of the eyeball in brachycephalic and mesocephalic dog breeds.

The anatomical structures forming the eyeball differ among dog breeds, both morphologically and morphometrically. This study was aimed at determining the morphometric values of the eyeball layers of different dog breeds and the morphological structures of these layers using scanning electron microscopy. Thirty-two eyeballs of 17 dogs belonging to 9 different breeds that died from traffic accidents, falling from a height, and naturally were used. These dog breeds were grouped according to their brachycephalic and mesocephalic skull structures, and morphometric measurements of the eyeballs of each group were obtained. Scanning electron microscopy was used to examine the morphological structure of the eyeball layers. The studied dogs' eyeballs comprised three layers: outer, middle, and inner. Thickness measurements obtained from three different regions of the eyeball indicated that the equatorial region was the thinnest among all dog breeds. Moreover, the cornea, which is covered by the sclera along its edges, was thicker at the corneal limbus than at the corneal vertex. A positive correlation was observed between lens thickness and the number of ciliary processes, which varied according to the dogs' head structures. Notably, depression was observed in the posterior surface of the lens in brachycephalic dogs. The morphometric values of the eyeball layers in the brachycephalic and mesocephalic dog breeds were also determined. These values will help researchers study this subject, and the determined morphometric and morphological values will contribute to the anatomy literature. RESEARCH HIGHLIGHTS: This comprehensive study investigates the morphometric and morphological variations in the eyeball layers of different dog breeds, utilizing scanning electron microscopy to analyze eyeballs. It reveals significant breed-specific differences, particularly between brachycephalic and mesocephalic dogs, regarding eyeball layer thickness, corneal structure, lens thickness, and the number of ciliary processes.

A morphological investigation of the tongue of roe deer (Capreolus capreolus Linnaeus, 1758).

The morphological structure of the tongue and papillae that occur on it vary according to an animal's lifestyle, nutrition, and adaptation to various environmental conditions. This study aimed to reveal in detail the morphological, histological, and electron microscopic structure of the tongue of roe deer (Capreolus capreolus Linnaeus, 1758). In this study, nine roe tongues were used. The tongue consists of three parts: the apex, body, and root. When the dorsal surface of the tongue was examined in detail, five different papillae were observed: filiform, lenticular, conical, fungiform, and vallate. Filiform papillae differed in having secondary papillae according to their localization. The opening holes of taste buds were observed on the surface of the round and flat fungiform papillae. The free ends of the filiform papillae were more pointed and thinner than those of the other papillae, while the width of the lenticular papillae was thicker, the surface was flat, and the free ends were blunt. Triangular-shaped conical papillae were observed differently regarding the presence or absence of secondary papillae. The vallate papillae were caudolateral to the lingual torus. On the surface of the vallate papillae, circumferenced by a deep groove, were the opening holes of the taste buds and microridges. From this analysis, it appears to be characteristic of roe deer that mechanical function, filiform, and conical papillae contain secondary papillae; lenticular papillae, absent in many deer species, are found; and a prominent papillary groove surrounds all mechanical and gustatory papillae. RESEARCH HIGHLIGHTS: The lingual papillae of roe deer (Capreolus capreolus Linnaeus, 1758) were examined with this study in detail for the first time. Similarities and differences with ruminant species were determined.

Morphology of the tongue dorsal surface of turbot (Scophthalmus maximus).

This study aimed to analyze the morphology of the tongue, which varies among fish species and has not been studied in turbot (Scophthalmus maximus), using macro-anatomical, light and scanning electron microscopy (SEM). As research materials, the tongues of eight adult turbot, which were used for consumption, were examined. The roughly triangular-shaped tongue of the turbot consisted of three parts: apex, body, and root. The thickness of the tongue continued to increase from the apex to the root. Although papillae were not observed in the macroscopic examination of the tongue, microscopic examination revealed the presence of cone-like shaped papillae on the submucosa. The tongue was composed of mucosa, submucosa, and hyaline cartilage. By SEM the presence of the taste buds (Types I and III), taste pores and papillae on the dorsal surface were demonstrated. Taste buds are the first descriptions in S. maximus. Therefore our results could add new data to the fish tongue anatomy. HIGHLIGHTS: Morphological and morphometric data of the turbot (Scophthalmus maximus) tongue were obtained in this study and compared with other species. In addition, the dorsal surface of the turbot tongue was described for the first time using SEM.

Comparison of sheep scapula models created with polylactic acid and thermoplastic polyurethane filaments by three-dimensional modelling.

Three-dimensional (3D) printing technology is a rapid prototyping method that has recently been increasingly used in anatomy education. Magnetic resonance imaging, computed tomography, and 3D scanners are generally used to create 3D models. The aim of this study, which was performed without using the aforementioned devices, is to design sheep scapula models in a computer environment and compare bone models created with different filaments printed by a 3D printer with real bone. Photographs of sheep scapula were taken for modelling, and measurements were made from certain points. After the photographs were transferred to a computer environment, they were transformed into 3D using the Cinema 4D software, a computer-aided design program. Models were created using a 3D printer employing polylactic acid (PLA) and thermoplastic polyurethane (TPU) filaments. By comparing the models created with PLA and TPU filaments to the real bone, it was found that they have a similar anatomical structure, with dimensional-morphometric differences found at some points. It was also observed that the scapula model created with PLA filaments was more resistant to impacts than the real bone and that the model created with TPU filaments was more flexible, with very low fragility as compared to PLA and real bone. Therefore, this method allows obtaining a large number of durable models as an alternative to the real bone without the need for much manpower or equipment and without the need for a 3D reconstruction device.

Telocytes in the hearts of Saanen goats.

Telocytes, new interstitial cells that have received significant attention in recent years, have been detected in many organs, including the heart. The distinction between telocytes and other interstitial cells can only be made based on their ultrastructural characterization and immunophenotypic features. In this study, we examined the interstitial cells in the healthy heart tissues of Saanen goats to determine whether they are telocytes or not, by using a scanning electron microscope (SEM) and immunohistochemical and immunofluorescence staining methods. The SEM revealed oval and round telocytes with two to four telopodes. Some telopodes also had podoms. The staining for immunohistochemical and immunofluorescence methods used for CD34, c-kit (CD117), and vimentin antibodies. Positive cells were detected in the heart muscle and heart valves by immunohistochemical staining. As these antigens can also be expressed by other non-telocyte cells, we used double immunofluorescence staining with CD34/c-kit and CD34/vimentin antibodies to identify true telocytes. Telocytes were determined in the right atrium and aortic valve. While telocytes were CD34+/c-kit+ and CD34+/vimentin+, fibroblasts were CD34-/vimentin+. These results confirm the presence of telocytes in the hearts of Saanen goats.