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

Biliary cystic disease and neoplasia: surgical management

Background Congenital cystic dilatation of the extra- and intrahepatic bile ducts is a rare condition with several potential complications, especially a high risk of malignant degeneration, which may develop from an anomalous arrangement of the pancreatico-biliary ductal junction. Patients Twenty-two patients with cystic dilatation of the biliary tree, subdivided according to the Todani classification, were observed and treated during a 17-year period. The intrahepatic ducts were involved in 15 patients. Results Surgical treatment involved either total excision of extrahepatic cysts, hepatic resection in cases of segmental intrahepatic disease or, in the presence of diffuse intrahepatic disease, a wide biliary-digestive anastomosis performed onto the biliary confluence, with the intent of reducing the risk of neoplastic degeneration. One patient with extensive and symptomatic liver involvement complicated by biliary cirrhosis has already undergone liver transplantation, and another two patients who are currently asymptomatic may require this procedure in future. Neoplastic degeneration was found in three patients (one each of Todani type I, type IVa and type V), or 14% of the series. The postoperative course was complicated by cholangitis in only two patients, who were treated successfully with antibiotics. Except for one patient with a type I cyst complicated by carcinoma, who died 14 months post-operatively, all patients are alive and well at a mean follow-up of eight years (range 8 months to 17 years). Discussion The ideal surgical procedures to cure the disease and prevent malignant degeneration are: (a) complete excision of the extrahepatic biliary cysts; (b) hepatic resection in cases of segmental intrahepatic involvement; (c) wide bilio-digestive anastomosis in cases of multiple intrahepatic involvement, or liver transplantation when this is complicated by secondary biliary cirrhosis

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

Novel contributions in canine craniometry : anatomic and radiographic measurements in newborn puppies

The largest differences in intraspecific head shape among the Carnivora order are to be found in dogs. Based on their skull morphotypes, dog breeds are currently classified as dolichocephalic, mesaticephalic and brachycephalic. Due to the fact that some breeds have not been yet defined, this classification is incomplete; moreover, multi-breed studies on the skull morphology of puppies have never been performed. The aim of this work was to verify (i) whether differences in the skull conformation of purebred puppies are already present within the first week of age; (ii) whether radiographic and anatomic measures could be considered interchangeable, and (iii) to possibly classify puppies from non-categorized breeds thanks to their radiographic cranial measurements using neural nets. One hundred and thirty-seven dead puppies aged 0-7 days were examined considering their anatomic and radiographic measures. All linear measures and anatomic indices significantly differed among brachycephalic and non-brachycephalic puppies. Radiographic indices, with the exception of CI, identified the three skull morphotypes (p<0.05, for all comparisons). Radiographic and anatomic measures proved to be non-interchangeable in newborn puppies. Finally, nineteen puppies belonging to 5 non-categorized breeds could be classified thanks to neural nets in the three skull morphotypes with different probability (P between 0,66 and 0,95)

Association of objectively measured physical activity with body components in European adolescents

Background: Physical activity (PA) is suggested to contribute to fat loss not only through increasing energy expenditure “per se” but also increasing muscle mass; therefore, it would be interesting to better understand the specific associations of PA with the different body’s components such as fat mass and muscle mass. The aim of the present study was to examine the association between objectively measured PA and indices of fat mass and muscle components independently of each other giving, at the same time, gender-specific information in a wide cohort of European adolescents. Methods: A cross-sectional study in a school setting was conducted in 2200 (1016 males) adolescents (14.7 ±1.2 years). Weight, height, skinfold thickness, bioimpedance and PA (accelerometry) were measured. Indices of fat mass (body mass index, % fat mass, sum of skinfolds) and muscular component (assessed as fat-free mass) were calculated. Multiple regression analyses were performed adjusting for several confounders including fat-free mass and fat mass when possible. Results: Vigorous PA was positively associated with height (p?<?0.05) in males, whilst, vigorous PA, moderate-vigorous PA and average PA were negatively associated with all the indices of fat mass (all p?<?0.01) in both genders, except for average PA in relation with body mass index in females. Regarding muscular components, vigorous PA showed positive associations with fat-free mass and muscle mass (all p?<?0.05) in both genders. Average PA was positively associated with fat-free mass (both p?<?0.05) in males and females. Conclusion: The present study suggests that PA, especially vigorous PA, is negatively associated with indices of fat mass and positively associated with markers of muscle mass, after adjusting for several confounders (including indices of fat mass and muscle mass when possible). Future studies should focus not only on the classical relationship between PA and fat mass, but also on PA and muscular components, analyzing the independent role of both with the different PA intensities

Hypoxia as a stimulus upon neonatal swinemeniscus cells: highway to phenotypic maturation of meniscal fibro-chondrocytes?

Menisci are essential structures in the knee joint where they cover fundamental biomechanical and protective roles (1-3). Menisci are characterized by a peculiar structure that, on one hand, allow them to perform their particular role in the stifle joint, but simultaneously make them a very challenging structure to deal with (2). Immature menisci are featured by numerously elongated cells (fibrocytes-like) in a disorganized matrix composed almost completely of collagen type I and few glycosaminoglycans (GAGs) and have a rich vascularization, on the other hand, mature and functional menisci are characterized by few round-shaped cells,a matrix rich of well ordinated collagen fibres (above all collagen type II) and GAGs, and preserve vascularization only in the outer zone (aka red zone) (1). Great interest, in both human and veterinary medicines, is reserved to the treatment of the injuries of the inner and avascular zone (aka white zone) of the meniscus: until now, there are no perfect solutions for the regeneration or the replacement of this tissue once injured (3). This work is focused on the utilization of an environmental factor like hypoxia in meniscal tissue culture, in order to evaluate if it could be utilized to improve meniscal culture with a view to tissue engineering. Ninety menisci from neonatal pigs (day 0) were harvested and cultured under two different atmospheric conditions (hypoxia with 1% O2 and normoxia) until 14 days. Samples were analysed at 0, 7 and 14 days through histochemical (Safranin-O staining), immunofluorescence and RT-PCR (Sox-9, Hif-1a, Hif-2, Collagen I and II, both methods) and biochemical (DNA, GAGs, DNA/GAGs ratio) techniques to record any possible differences in maturation of meniscal cells. Safranin-O staining allowed to show an increment in matrix deposition and round-shape \u201cfibro-chondrocytic\u201d cells quantity of hypoxia-cultured menisci respect to controls under normal atmospheric conditions. The same maturation shifting was observed by means of immunofluorescence and RT-PCR analysis, characterized by an increment of Sox-9 and collagen II, moving from day zero to 14-days under hypoxic environment, and by biochemical analysis,with an increment of DNA/GAGs ratio typical of mature meniscal tissue (characterized by few cells and much GAGs). This study shows that hypoxia can be considered as a booster to achieve meniscal cells maturation and opens considerably opportunities in the field of meniscus tissue engineering. References 1. Dai Z, et al. J Orthop Res 2013 ;31:1514-9, 2. Fox AJS, et al. Clin Anat 2015 ;28:269-87 3. Sosio C, et al. Tissue Eng Part A 2015 ;21:3-4

Meniscus maturation in the swine model: role of endostatin in cellular differentiation

The development of an engineered meniscus derives from the need to regenerate a tissue which is largely unable to self-repair with consequent loss of functionality. Hence a deeper knowledge of the native meniscus morphology and biomechanics in its different regions, including molecules involved in regulation of the maturation process, is essential. The meniscus is a complex tissue, displaying great regional variation in extracellular matrix components and in vascularization, as a result of several biomechanical stimuli. Its biochemical composition is modulated to adapt the tissue to the different functions that are required throughout growth, until a \u201cmature\u201d phase is reached in adulthood. The aim of this work is to evaluate the biological role of Endostatin in the regulation of angiogenesis as in the fibro-chondrogenic differentiation of neonatal meniscal cells in the pig. The swine is an attractive model for meniscal repair studies, as its knee joint is closely comparable to the human one in terms of anatomical structure, vascularization, and healing potential. Our preliminary data show that Endostatin contributes to the acquisition of chondrocyte phenotype in an undifferentiated but committed cellular population. Thus, a better understanding of the role of Endostatin in cell metabolism might lead to a deeper knowledge of the events regulating meniscus maturation. These findings may be crucial for the development of an engineered scaffold able to induce meniscal cell differentiation by releasing Endostatin-rich microspheres

Swine cortical and cancellous bone: histomorphometric and densitometric characterisation

Introduction: Swine bone morphology, composition and remodelling are similar to humans\u2019, 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

Ultrastructural and matrix evaluation of morpho-functional age-related changes in dog meniscus

Menisci are essential structures for the knee joint. Different attempts were made trying to replace or regenerate the meniscus after its tear, but the perfect solution is still far away. A better knowledge of the physiologic development of this structure through time could be useful to understand its behavior in the light of the tissue bio-engineering. In this study, the changes in canine meniscal morphology were evaluated to assess how it varies among diverse age stages. The fibers arrangement and matrix deposition in canine menisci from neonatal (died at birth), 10-days, 30-days and adult dogs, dead for causes not related to the present study, were evaluated by means of histochemistry (safranin-O and Sirius red staining), polarized light microscopy, immunofluorescence (collagen I and II) and Scanning Electron Microscopy (SEM). Moreover, quantitative measurements of glycosaminoglycans (GAGs), DNA and GAGs/DNA ratio were performed. The \u201cknotty\u201d structure of neonatal meniscus is probably due to balls of collagen fibres that are not completely stretched until the 30-days stage (Fig 1). The stretching of the fibres starts from the inner portion that is probably the first and the most compressed zone. Safranin-O staining shows how matrix composition vary during growth. Neonatal meniscus is characterized by a huge number of elongated cells (fibroblast-like) and GAGs, features that characterized a still afunctional tissue. With growth, more and more cells assumed a rounded shape. The end-point of the maturation process is represented by the adult meniscus: it is characterized by almost only rounded cells (fibro-chondrocyte-like), in small number, and surrounded by matrix (Fig 1). Nevertheless, 10-30 days interval could be considered the starting point of the meniscus specialization and maturation. Fibres arrangement starts like balls of collagen fibres that follow a disorganized pattern in the neonatal meniscus (Fig 1). In 10-days meniscus, these balls of fibres tend to disappear starting from the meniscus\u2019 inner portion, in association with an initial organization of the fibres according to the longitudinal and radial axes of the meniscus. The organization of fibres network is almost complete at 30-days of life, when all the fibres follow the two main axes of the meniscus and show a well-organized disposition, as seen in adult meniscus. Through the double immunofluorescence it is possible to recognized different aspect of maturation (Fig 3). Neonatal meniscus shows almost only collagen type I fibres. Collagen type I and II co-expression starts at 10 days (yellow) and become more evident in 30-days meniscus in which even a differentiation of the inner and the outer zone starts. The same differentiation persist in adult meniscus that is characterized by a frankly fibro-chondrocitic-like cellular phenotype. Biochemical analysis confirmed that cellularity decrease over the time starting from neonatal to adult (Fig 3). The same decreasing trend is observed in GAGs deposition. Even if 30-days meniscus present a lot of common characteristics with the adult one, the GAGs/DNA ratios show how the latter is the only that present a maturely functional tissue in which a small number of cells is able to produce a matrix rich of GAGs. Meniscal structure changes during growth. The starting point is represented by the neonatal tissue, rich of immature cells and with poor expression of matrix components. The end-point is the adult tissue, characterized by phenotypically mature cells, which assure a functional matrix deposition. Ten-thirty days interval seems to be the turning point of this developmental process. This work highlights how dog meniscal structure changes its morphology among different age stages; this fact may suggest a role of the biomechanical forces, physiologically acting on meniscus, in the development of its ultimate shape and functions. The knowledge of the developmental process of a structure has a capital importance to comprehend its physiologic anatomy and function

Recent advances on smart glycoconjugate vaccines in infections and cancer

Vaccination is one of the greatest achievements in biomedical research preventing death and morbidity in many infectious diseases through the induction of pathogen-specific humoral and cellular immune responses. Currently, no effective vaccines are available for pathogens with a highly variable antigenic load, such as the human immunodeficiency virus or to induce cellular T-cell immunity in the fight against cancer. The recent SARS-CoV-2 outbreak has reinforced the relevance of designing smart therapeutic vaccine modalities to ensure public health. Indeed, academic and private companies have ongoing joint efforts to develop novel vaccine prototypes for this virus. Many pathogens are covered by a dense glycan-coat, which form an attractive target for vaccine development. Moreover, many tumor types are characterized by altered glycosylation profiles that are known as “tumor-associated carbohydrate antigens”. Unfortunately, glycans do not provoke a vigorous immune response and generally serve as T-cell-independent antigens, not eliciting protective immunoglobulin G responses nor inducing immunological memory. A close and continuous crosstalk between glycochemists and glycoimmunologists is essential for the successful development of efficient immune modulators. It is clear that this is a key point for the discovery of novel approaches, which could significantly improve our understanding of the immune system. In this review, we discuss the latest advancements in development of vaccines against glycan epitopes to gain selective immune responses and to provide an overview on the role of different immunogenic constructs in improving glycovaccine efficacy