Autologous Mesenchymal Stromal Cells Immobilized in Plasma-Based Hydrogel for the Repair of Articular Cartilage Defects in a Large Animal Model.

The treatment of cartilage defects in trauma injuries and degenerative diseases represents a challenge for orthopedists. Advanced mesenchymal stromal cell (MSC)-based therapies are currently of interest for the repair of damaged cartilage. However, an approved system for MSC delivery and maintenance in the defect is still missing. This study aimed to evaluate the effect of autologous porcine bone marrow MSCs anchored in a commercially available polyglycolic acid-hyaluronan scaffold (Chondrotissue®) using autologous blood plasma-based hydrogel in the repair of osteochondral defects in a large animal model. The osteochondral defects were induced in twenty-four minipigs with terminated skeletal growth. Eight animals were left untreated, eight were treated with Chondrotissue® and eight received Chondrotissue® loaded with MSCs. The animals were terminated 90 days after surgery. Macroscopically, the untreated defects were filled with newly formed tissue to a greater extent than in the other groups. The histological evaluations showed that the defects treated with Chondrotissue® and Chondrotissue® loaded with pBMSCs contained a higher amount of hyaline cartilage and a lower amount of connective tissue, while untreated defects contained a higher amount of connective tissue and a lower amount of hyaline cartilage. In addition, undifferentiated connective tissue was observed at the edges of defects receiving Chondrotissue® loaded with MSCs, which may indicate the extracellular matrix production by transplanted MSCs. The immunological analysis of the blood samples revealed no immune response activation by MSCs application. This study demonstrated the successful and safe immobilization of MSCs in commercially available scaffolds and defect sites for cartilage defect repair.

Bony canal and grooves of the middle meningeal artery: mythic structures in anatomy and neurosurgery?

BACKGROUND: It has been previously published that the frontal branch of the middle meningeal artery (MMA) is usually embedded in a bony canal (BC). Although the incidence of the BC was over 70%, this structure is currently omitted both in anatomical nomenclature and in most of the literature. We found the same gap pertaining to the grooves for the MMA on the skull base. The aims of our study were to assess the incidence and morphometry of the MMA BC and grooves on the skull base. MATERIALS AND METHODS: Computed tomography (CT) scans of 378 patients, 172 skull bases as well as 120 sphenoidal bones and 168 temporal bones, and 12 histological specimens from 3 men and 3 women and 3 different regions of the MMA course were assessed. RESULTS: Based on CT scans, the incidence of the BC was 85.44% and was significantly higher in females than in males. Most of the canals and grooves were bilateral. The mean canal length was 17.67 mm, the mean transverse diameter 1.33 mm, and the mean distance from the superior orbital fissure (dFOS) was 26.7 mm. In the skull bases, the BC incidence was 70.07%, the mean canal length 10.74 mm, and the mean dFOS was 19.16 mm. The groove for the MMA on the temporal and sphenoidal bones was present in 99.42% and 95.35%, respectively. Histological specimens confirmed the presence of the MMA and accompanying vein/s. CONCLUSIONS: Based on our results, we suggest the addition of the BC and grooves for the middle meningeal vessels to the upcoming version of the Terminologia Anatomica.

Animal models of liver diseases and their application in experimental surgery.

Both acute and chronic liver diseases are frequent and potentially lethal conditions. Development of new therapeutic strategies and drugs depends on understanding of liver injury pathogenesis and progression, which can be studied on suitable animal models. Due to the complexity of liver injury, the understanding of underlying mechanisms of liver diseases and their treatment has been limited by the lack of satisfactory animal models. SO far, a wide variety of animals has been used to mimic human liver disease, however, none of the models include all its clinical aspects seen in humans. Rodents, namely rats and mice, represent the largest group of liver disease models despite their limited resemblance to human. On the other hand, large animal models like pigs, previously used mostly in acute liver failure modeling, are now playing an important role in studying various acute and chronic liver diseases. Although significant progress has been made, the research in hepatology should continue to establish animal models anatomically and physiologically as close to human as possible to allow for translation of the experimental results to human medicine. This review presents various approaches to the study of acute and chronic liver diseases in animal models, with special emphasis on large animal models and their role in experimental surgery.

Distribution of Connective Tissue in the Male and Female Porcine Liver: Histological Mapping and Recommendations for Sampling.

The pig is a large animal model that is often used in experimental medicine. The aim of this study was to assess, in normal pig livers, sexual dimorphism in the normal fraction of hepatic interlobular and intralobular connective tissue (CT) in six hepatic lobes and in three macroscopical regions of interest (ROIs) with different positions relative to the liver vasculature. Using stereological point grids, the fractions of CT were quantified in histological sections stained with aniline blue and nuclear fast red. Samples (415 tissue blocks) were collected from healthy piglets, representing paracaval, paraportal and peripheral ROIs. There was considerable variability in the CT fraction at all sampling levels. In males the mean fraction of interlobular CT was 4.7 ± 2.4% (mean ± SD) and ranged from 0% to 11.4%. In females the mean fraction of the interlobular CT was 3.6 ± 2.2% and ranged from 0% to 12.3%. The mean fraction of intralobular (perisinusoidal summed with pericentral) CT was <0.2% in both sexes. The interlobular CT represented >99.8% of the total hepatic CT and the fractions were highly correlated (Spearman r = 0.998, P <0.05). The smallest CT fraction was observed in the left medial lobe and in the paracaval ROI and the largest CT fraction was detected in the quadrate lobe and in the peripheral ROI. For planning experiments involving the histological quantification of liver fibrosis and requiring comparison between the liver lobes, these data facilitate the power analysis for sample size needed to detect the expected relative increase or decrease in the fraction of CT.