284 research outputs found
Autologous bone marrow mononuclear cells (Bmmcs) for the treatment of uncomplicated grade 2 ununited anconeal process (uap) in six dogs: Preliminary results
The aim of this study was to report the results of autologous bone marrow mononuclear cell (BMMC) transplantation as a minimally invasive treatment for grade 2 UAP in dogs. This was an observational case series on six German shepherd dogs affected by grade 2 UAP as defined according to their clinical condition as well as radiographic and CT findings. Bone marrow was collected from the iliac crest and the mononuclear fraction was separated with density gradient centrifugation. Cells were suspended in fibrin glue before BMMC administration and implanted via transcutaneous injection under IB or CT guidance, using a spinal needle directly inserted into the ossification centre between the anconeal process and the olecranon. Clinical and radiographic follow-up was performed for up to 6 months. Microradiographic assessment was performed on one dog that died of other causes. A progressive reduction of pain within 3 weeks after BMMC administration was observed in all dogs, with gradually increased weight bearing on the affected limb. Radiographic and CT follow-up revealed the progressive fusion of the ossification centre at 90 days without any signs of secondary OA. The examination of microradiographs showed newly formed bone tissue in which a residue of calcified cartilage was present at the site of BMMC implantation. On the basis of these results, BMMC therapy for grade 2 UAP may be considered to be an effective and minimally invasive treatment option for dogs
Comparison of laparoscopic steerable instruments performed by expert surgeons and novices
As an alternative to the surgical robot, some medical companies have engineered new steerable devices that mimic the robot's capacities. This study aimed to assess how steerable instruments ameliorate the efficacy of suturing in comparison with the traditional instrument, and a combination instruments, performed by experienced and novice surgeons. The study was performed by three experienced surgeons and three novice surgeons. The instruments employed were divided into three surgical sets: two steerable dissectors; one steerable dissector and one straight needle ; two straight needle holders. The study supervisor recorded the total time for the procedure, the number of bites completed, the time for each bite, and the quality of the procedure. In our study, we found consistent data demonstrating that experienced laparoscopists completed the prescribed suture pattern with more bites in less time than novices. The use of two steerable instruments was more time consuming than standard straight instruments, but a combination of instruments was significantly less time consuming, as was the use of two straight needle holders. This result was even observed in novice surgeons. Combining a steerable instrument with a traditional straight needle holder provided more advantages in this study
Ultrastructural study of cultured ovine bone marrow-derived mesenchymal stromal cells.
Ovine bone marrow-derived mesenchymal stromal cells (oBM-MSCs) represent a good animal model
for cell-based therapy and tissue engineering. Despite their use as a new therapeutic tool for several
clinical applications, the morphological features of oBM-MSCs are yet unknown. Therefore, in this study
the ultrastructural phenotype of these cells was analysed by transmission electron microscopy (TEM).
The oBM-MSCs were isolated from the iliac crest and cultured until they reached near-confluence. After
trypsinization, they were processed to investigate their ultrastructural features as well as specific surface
marker proteins by flow cytometry and immunogold electron microscopy. Flow cytometry displayed
that all oBM-MSCs lacked expression of CD31, CD34, CD45, HLA-DR whereas they expressed CD44, CD58,
HLAI and a minor subset of the cell population (12%) exhibited CD90. TEM revealed the presence of two
morphologically distinct cell types: cuboidal electron-lucent cells and spindle-shaped electron-dense
cells, both expressing the CD90 antigen. Most of the electron-lucent cells showed glycogen aggregates,
dilated cisternae of RER, moderately developed Golgi complex, and secretory activity. The electron-dense
cell type was constituted by two different cell-populations: type A cells with numerous endosomes,
dense bodies, rod-shaped mitochondria and filopodia; type B cells with elongated mitochondria, thin
pseudopodia and cytoplasmic connectivity with electron-lucent cells. These morphological findings could
provide a useful support to identify “in situ” the cellular components involved in the cell-therapy when
cultured oBM-MSCs are injected
Intraoperative assessment of fluid responsiveness in normotensive dogs under isoflurane anaesthesia
The aim of this study was to evaluate the incidence of fluid responsiveness (FR) to a fluid challenge (FC) in normotensive dogs under anaesthesia. The accuracy of pulse pressure variation (PPV), systolic pressure variation (SPV), stroke volume variation (SVV), and plethysmographic variability index (PVI) for predicting FR was also evaluated. Dogs were anaesthetised with methadone, propofol, and inhaled isoflurane in oxygen, under volume-controlled mechanical ventilation. FC was performed by the administration of 5 mL/kg of Ringer’s lactate within 5 min. Cardiac index (CI; L/min/m2), PPV, (%), SVV (%), SPV (%), and PVI (%) were registered before and after FC. Data were analysed with ANOVA and ROC tests (p < 0.05). Fluid responsiveness was defined as 15% increase in CI. Eighty dogs completed the study. Fifty (62.5%) were responders and 30 (37.5%) were nonresponders. The PPV, PVI, SPV, and SVV cut-off values (AUC, p) for discriminating responders from nonresponders were PPV >13.8% (0.979, <0.001), PVI >14% (0.956, <0.001), SPV >4.1% (0.793, <0.001), and SVV >14.7% (0.729, <0.001), respectively. Up to 62.5% of normotensive dogs under inhalant anaesthesia may be fluid responders. PPV and PVI have better diagnostic accuracy to predict FR, compared to SPV and SVV
Evaluation of in vivo response of three biphasic scaffolds for osteochondral tissue regeneration in a sheep model
Osteochondral defects are a common problem in both human medicine and veterinary practice although with important limits concerning the cartilaginous tissue regeneration. Interest in the subchondral bone has grown, as it is now considered a key element in the osteochondral defect healing. The aim of this work was to generate and to evaluate the architecture of three cell-free scaffolds made of collagen, magnesium/hydroxyapatite and collagen hydroxyapatite/wollastonite to be implanted in a sheep animal model. Scaffolds were designed in a bilayer configuration and a novel "Honey" configuration, where columns of hydroxyapatite were inserted within the collagen matrix. The use of different types of scaffolds allowed us to identify the best scaffold in terms of integration and tissue regeneration. The animals included were divided into four groups: three were treated using different types of scaffold while one was left untreated and represented the control group. Evaluations were made at 3 months through CT analysis. The novel "Honey" configuration of the scaffold with hydroxyapatite seems to allow for a better reparative process, although we are still far from obtaining a complete restoration of the defect at this time point of follow-up
Endothelial dysfunction and renal fibrosis in endotoxemia-induced oliguric kidney injury: possible role of LPS binding protein
The pathophysiology of endotoxemia-induced acute kidney injury (AKI) is characterized by an intense activation of the host immune system and renal resident cells by lipopolysaccharide (LPS) and derived proinflammatory products. However, the occurrence of renal fibrosis in this setting has been poorly investigated. The aim of the present study was to investigate the possible association between endothelial dysfunction and acute development of tissue fibrosis in a swine model of LPS-induced AKI. Moreover, we studied the possible effects of coupled plasma filtration adsorption (CPFA) in this setting
Comprehensive in vitro and in vivo studies of novel melt-derived Nb-substituted 45S5 bioglass reveal its enhanced bioactive properties for bone healing
The present work presents and discusses the results of a comprehensive study on the bioactive properties of Nb-substituted silicate glass derived from 45S5 bioglass. In vitro and in vivo experiments were performed. We undertook three different types of in vitro analyses: (i) investigation of the kinetics of chemical reactivity and the bioactivity of Nb-substituted glass in simulated body fluid (SBF) by 31P MASNMR spectroscopy, (ii) determination of ionic leaching profiles in buffered solution by inductively coupled plasma optical emission spectrometry (ICP-OES), and (iii) assessment of the compatibility and osteogenic differentiation of human embryonic stem cells (hESCs) treated with dissolution products of different compositions of Nb-substituted glass. The results revealed that Nb-substituted glass is not toxic to hESCs. Moreover, adding up to 1.3 mol% of Nb2O5 to 45S5 bioglass significantly enhanced its osteogenic capacity. For the in vivo experiments, trial glass rods were implanted into circular defects in rat tibia in order to evaluate their biocompatibility and bioactivity. Results showed all Nb-containing glass was biocompatible and that the addition of 1.3 mol% of Nb2O5, replacing phosphorous, increases the osteostimulation of bioglass. Therefore, these results support the assertion that Nb-substituted glass is suitable for biomedical applications
Pentraxin-3-mediated complement activation in a swine model of renal ischemia/reperfusion injury
Pentraxins are a family of evolutionarily conserved pattern recognition molecules with pivotal roles in innate immunity and inflammation, such as opsonization of pathogens during bacterial and viral infections. In particular, the long Pentraxin 3 (PTX3) has been shown to regulate several aspects of vascular and tissue inflammation during solid organ transplantation.Our study investigated the role of PTX3 as possible modulator of Complement activation in a swine model of renal ischemia/reperfusion (I/R) injury.We demonstrated that I/R injury induced early PTX3 deposits at peritubular and glomerular capillary levels. Confocal laser scanning microscopy revealed PTX3 deposits co-localizing with CD31+ endothelial cells. In addition, PTX3 was associated with infiltrating macrophages (CD163), dendritic cells (SWC3a) and myofibroblasts (FSP1). In particular, we demonstrated a significant PTX3-mediated activation of classical (C1qmediated) and lectin (MBL-mediated) pathways of Complement. Interestingly, PTX3 deposits co-localized with activation of the terminal Complement complex (C5b-9) on endothelial cells, indicating that PTX3-mediated Complement activation occurred mainly at the renal vascular level. In conclusion, these data indicate that PTX3 might be a potential therapeutic target to prevent Complement-induced I/R injury.Nephrolog
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