Meniscal femoral and tibial surfaces characterization in the swine model.

Menisci are wedge-like structures interposed, in the knee joint, between the femoral and the tibial articular heads (Kohn et al. 1995; Greis et al. 2002). Improving the articular surface, the cellular nutrition and the articular lubrication, they are essential structures for the prevention of gonarthrosis (Proctor et al.1989; Makris et al. 2011). This study is focused upon the relationship between the contact forces at the femoral and tibial surfaces and the corresponding structure of these meniscal surfaces. For this purpose, 20 adult (~9 months old) female pigs (Landrace x Large white, average weight 75–90 kg; n=80 meniscal samples) were obtained from a local slaughterhouse and dissected to isolate the menisci. Swine meniscal samples were evaluated from morphological (Safranin-O, Sirius Red and collagen type I and II) (Di Giancamillo et al. 2014), biochemical (DNA and glycosaminoglycans, or GAGs, contents) and biomechanical (compression and traction tests) points of view at the level of femoral and tibial meniscal surfaces. Results revealed a characterization of the meniscus which is biomechanical-dependent.  The femoral surface, morphologically characterized by the interposition of radial and oblique fibers and biomechanically by the femoral condyles compression, sliding and rolling forces, shows a higher compressive modulus (p<0.05) and a greater amount of cells and GAGs deposition (p<0.01 for each analysis). On the other hand, results from traction test revealed a higher tensile modulus (p<0.05) in the tibial surface, characterized by a circumferential arrangement of the fibers and a poorer GAGs deposition and cellular distribution (p<0.01). Results (summarized in the figure 1) from this work suggest that a biphasic “femoral-to-tibial” scaffold that mimic the different behavior and composition of the two meniscal surfaces could be useful in the light of meniscal replacement.

Stifle anatomic, tomographic and biomechanical features of growing dogs affected by quadriceps contracture.

Quadriceps contracture is a debilitating and uncommon condition, mostly affecting young dogs. Itcan be congenital or acquired ) and is reported to induce muscular hypotrophy/fibrosis, progressive degenerative joint disease, bone hypoplasia and limb hyperextension. The aim of this study was to elucidate anatomic, tomographic and biomechanical features of stifles affected by quadriceps contracture.Seven 2-month-old dead Dobermann Pinschers with unilateral quadriceps contracture were included. Before gross anatomic evaluation, all stifles underwent Computed Tomography before and after intra-articular administration of iodinated contrast medium. Images were acquired in double positioning (stifle extension and flexion) to identify articular cartilage, Ossification Centres’ (OCs) and menisci abnormalities, which were compared between affected and unaffected limbs. In all affected limbs the stifle was back-turned, the distal femur was extra-rotated and the patella was luxated proximo-medially. Severe lack of physiological stifle movements (rolling, gliding, spinning) was observed, so that affected joints could not be flexed. The articular cartilage of the femur was flattened and irregular in thickness, the femoral trochlea was hypoplasic and sloping, the menisci were misshaped. The OC of the distal femur and proximal tibia were misshaped; the tibial plateau was oriented caudodorsally-cranioventrally and significantly smaller (P<0,05). Quadriceps contracture influenced stifle development. The action of quadriceps insertion on the tibia prevented normal development of the plateau, causing wedging and abnormal orientation. Constant compression also induced external rotation of the distal femur (unable to develop distally) and patellar luxation, ending up in genu recurvatum. Static compression was likely responsible for femoral trochlea hypoplasia, articular cartilage and meniscal deformation, due to the lack of physiological stifle movements.Quadriceps contracture induces severe alterations of stifle development in affected puppies. Histology, histochemistry and immunohistochemistry may better define the nature of such bone, cartilage and meniscal alterations

Swine cortical and cancellous bone: histomorphometric and densitometric characterisation

Introduction: Swine bone morphology, composition and remodelling are similar to humans’, therefore they are considered good models in bone-related research. They have been used for several studies involving bone growth, bone and cartilage fractures and femoral head osteonecrosis. Nevertheless, the literature about pig normal bone features is incomplete. This work aims to fill the literature gaps on the microarchitecture and Bone Mineral Density (BMD) of swine femoral diaphysis and distal epiphysis and tibial plateau and diaphysis.Materials and methods: Five hind limbs were collected from slaughtered 80-100 kg pigs. Microscopic analysis of cortical and cancellous bone from middle/distal femur and proximal/middle tibia was performed to determine basic histomorphometric parameters at different sites. Dual-energy X-Rays Absorptiometry was also employed to evaluate BMD. ANOVA and correlation between BMD, bone area (BA) and cortical thickness were performed.Results and discussion: Diaphyseal cortical bone was mostly plexiform both in the tibia and the femur; primary/secondary osteons without clear organization were also found. Mean values for bone area, bone perimeter, trabecular width, number and separation and BMD at different anatomical sites were defined. No significant difference was found for these values at different anatomical sites. BMD proved to be positively correlated with cortical thickness (r=0,80; p<0,01). Despite the small sample size, these results seem homogeneous. They could therefore represent reference values for normal bone parameters in pigs. Applied anatomy and regenerative medicine, in fact, demand very precise information about bone micromorphology, composition and density to provide reliable indication in bone substitutes building. Moreover, since the interpretation of bone abnormalities is based on mastering normal bone characteristics, the definition of reference parameters is mandatory to avoid misinterpretation and allow comparative evaluation.Conclusion: The results of this study, although preliminary, may be considered a dependable starting point for the definition of normal bone features in pigs

Oxidative stress and lateral muscle development in Siberian Sturgeon (Acipenser baeri): preliminary observations.

Embryonic development in bony fish is strongly influenced by environmental factors, mainly by temperature and dissolved oxygen, but little is known about their influence on Sturgeons. Since 1998 the international trade of Sturgeons has been regulated under CITES due to depletion of wild stocks. Sturgeon aquaculture as well as larvae production is, therefore, important because it may contribute to the repopulation of the wild stocks (Bronzi et al., 2011; Di Giancamillo et al., 2012).The aim of this study is to monitor oxidative stress status and muscle development during embryonic and precocious larval phases in Siberian Sturgeon (Acipenser baeri), when subjected to different incubating temperatures (13°, 16° and 19°C).Siberian sturgeon eggs were subjected to different incubation temperatures. Data regarding water quality parameters were recorded, as well as mortalities, embryonic period length, and precocious larvae behavior. Sampling was performed in the same developmental stage for each temperature, at five time points: 48 hours post-fertilization, embryo movements, hatching, schooling and yolk-sac full absorption. The observed hatching rates were between 85.5% and 98.8% with significant differences concerning the different experimental temperatures (T19 vs T13 and T19 vs T16, p<0,05). Histological, histochemical and immunohistochemical analyses will be performed to assess ontogeny of the lateral muscle and stress biomarkers (Lushchak, 2011), and gene expression will be analyzed for muscle development (Johnston, 2006). The obtained results will be compared with those concerning teleosts and will possibly contribute to better rearing conditions of sturgeons.This study has been approved by the ethic committee of the Università degli Studi di Milano, with the following authorisation code: OPBA_20_2016.

Effect of different stocking densities on growth, muscle development and fatty acid profile of Acipenser baerii larvae

Sturgeons, as well as paddlefishes, belong to the Acipenseriformes group, which is one of the most primordial 57 orders of the Osteichthyes that comprehends 25 species spread throughout Europe, Asia and North America. The present study aims at investigating muscle growth and development as well as fatty acid profile in Siberian sturgeon free-embryos when subjected to three different rearing densities. Fatty acids, in particular polyunsaturated fatty acids of n-3 series, are generally known as key nutrients in fish larvae.This study was approved by the Ethic Committee of the University of Milan (OPBA_22_2017). Siberian sturgeon larvae were reared at 18°C, at three stocking densities until complete yolk-sac absorption: low (LD, 30 larvae/l), mid (MD, 80 larvae/l) and high (HD, 150 larvae/l). Sampling timepoints were: hatching, schooling and complete yolk-sac absorption stage (YSA). Sacrificed larvae were weighed and histological analyses were performed in order to assess muscle development as described elsewhere ; fatty acid profile was determined by GC-FID analysis as described by Vasconi et al. (2015). Statistical analysis was performed with SAS software (v. 9.3, Cary Inc., NC).At the end of the experiment, LD larvae presented a higher weight than larvae reared at the other two densities (P<0.05). Within the schooling stage (Figure 1), Total Muscle Area was lower for HD larvae (P<0.05); red and white muscle areas in schooling and YSA were higher than at hatching (P<0.05), regardless the density. Concerning fatty acids, no statistical differences were recorded between different rearing densities, while during the development regardless the rearing density, there was a common pattern: linoleic and alfa linolenic acids, significantly decreased their relative content, while others, as arachidonic acid and DHA, significantly increased. Siberian sturgeon larvae reared at LD or MD reveal an anatomically normal muscle development, while in the HD it is possible to observe a slowdown.What the aquaculture industry requires is a set of guidelines that allows the development of a sustainable industry, so that we tried to develop guidelines for stocking density in the very early stage of farming. As a conclusion, it would seem that mid density could be more suitable for this species in this stage of development

Meniscus Matrix Remodeling in Response to Compressive Forces in Dogs

Joint motion and postnatal stress of weight bearing are the principal factors that determine the phenotypical and architectural changes that characterize the maturation process of the meniscus. In this study, the effect of compressive forces on the meniscus will be evaluated in a litter of 12 Dobermann Pinschers, of approximately 2 months of age, euthanized as affected by the quadriceps contracture muscle syndrome of a single limb focusing on extracellular matrix remodeling and cell-extracellular matrix interaction (i.e., meniscal cells maturation, collagen fibers typology and arrangement). The affected limbs were considered as models of continuous compression while the physiologic loaded limbs were considered as controls. The results of this study suggest that a compressive continuous force, applied to the native meniscal cells, triggers an early maturation of the cellular phenotype, at the expense of the proper organization of collagen fibers. Nevertheless, an application of a compressive force could be useful in the engineering process of meniscal tissue in order to induce a faster achievement of the mature cellular phenotype and, consequently, the earlier production of the fundamental extracellular matrix (ECM), in order to improve cellular viability and adhesion of the cells within a hypothetical synthetic scaffold

Nutritional Regulation of Gut Barrier Integrity in Weaning Piglets

Simple Summary Weaning is a very stressful period in the piglet's life in intensive farming: it is a sudden process occurring between three to four weeks of age, when the gastrointestinal tract (GIT) is still immature. The GIT is formed by the epithelial, immune and enteric nervous system which controls epithelial barrier integrity as well as gut functions including the transport of luminal nutrients, water and electrolytes. Early weaning is characterized by a breakdown of these gut functions, an increase in intestinal permeability and the appearance of gastrointestinal functional disorders, which can have long-lasting consequences in the pig's life. Weaning, therefore, requires the correct level of nutrients, high quality ingredients, and management, which are directed primarily at encouraging rapid feed intake whilst reducing mortality and morbidity. This review describes the organization of the GIT and highlights the interactions between feed components and the morphology and physiology of the epithelial barrier. Novel dietary strategies focused on improving gut health are also discussed, considering the impacts of selected feed ingredients or additives on the GIT such as functional amino acids, phytochemicals and organic acids. Abstract Weaning is very stressful for piglets and leads to alterations in the intestinal barrier, a reduction in nutrient absorption and a higher susceptibility to intestinal diseases with heavy economic losses. This review describes the structures involved in the intestinal barrier: the epithelial barrier, immune barrier and the enteric nervous system. Here, new insights into the interactions between feed components and the physiology and morphology of the epithelial barrier are highlighted. Dietary strategies focused on improving gut health are also described including amino acids, phytochemicals and organic acids

Imaging techniques in Veterinary Medicine. Part I: Radiography and Ultrasonography

In Veterinary Medicine all the Imaging techniques are used and described but, due to organizational, managerial and, mostly, economical reasons, Radiography and Ultrasonography are the most used. Veterinary Radiology teaching has a relatively small number of educational credits in the degree courses but, nowday, educational opportunities are remarkably increased thanks to a number of post-degree courses and masters, organized both by the universities and private veterinary associations. The relevance of Diagnostic Imaging is particularly true in Veterinary Medicine, in which Radiology could be considered “indispensable” for diagnosis, prognosis and follow up. Furthermore, it should not be forgotten that the diagnostic image represents a “document” and, has a relevant role in legal medical debats. In this first part, Radiography and Ultrasonography are described

Seaweeds in pig nutrition

Seaweeds are macroalgae, with different sizes, colors and composition. They consist of brown algae, red algae and green algae, which all have a different chemical composition and bioactive molecule content. The polysaccharides, laminarin and fucoidan are commonly present in brown seaweeds, ulvans are found in green seaweeds and, red algae contain a large amount of carrageenans. These bioactive compounds may have several positive effects on health in livestock. In order to reduce the antimicrobials used in livestock, research has recently focused on finding natural and sustainable molecules that boost animal performance and health. The present study thus summarizes research on the dietary integration of seaweeds in swine. In particular the influence on growth performance, nutrients digestibility, prebiotic, antioxidant, anti-inflammatory, and immunomodulatory activities were considered. The review highlights that brown seaweeds seem to be a promising dietary intervention in pigs in order to boost the immune system, antioxidant status and gut health. Data on the use of green seaweeds as a dietary supplementation seems to be lacking at present and merit further investigation

Cartilage canals in newborn dogs : histochemical and immunohistochemical findings

Cartilage canals (CCs) are microscopic structures involved in secondary ossification centers (SOCs) development. The features of CCs were investigated in the humeral and femoral proximal epiphyses of small-sized newborn dogs (from premature to 28 days after birth) with histochemical and immunohistochemical approaches. Masson's Trichrome revealed a ring-shaped area around CCs, which changes in colour from green (immature collagen) to red (mature collagen) as ossification progresses; perichondrium staining always matched the ring colour. Safranin-O was always negative. Immunohistochemical analysis revealed immunopositivity for both collagen type I and V around the CCs; collagen type II was negative. CCs count showed a tendency to be higher in the humerus than in the femur. This work enlightened for the first time changes in composition of CCs surrounding matrix during SOCs development in dogs, paving the way to further investigations