541 research outputs found

    Mitochondrial DNA lineages of Italian Giara and Sarcidano horses

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    Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed

    Platelet lysate maintains chondrogenic potential and promotes cartilage regeneration

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    cartilage. We report the biological effect of the platelet lysate (PL), a PRP derivative, on primary human articular chondrocytes (HAC) cultured under both physiological and inflammatory condition. Added to the culture medium, PL induced a strong mitogenic response in the chondrocytes. The in vitro expanded cell population maintained a chondrogenic re-­‐differentiation potential as revealed by micromass culture in vitro as well as in vivo as demonstrated by ectopic cartilage formation in nude mice. Furthermore, in chondrocytes cultured in the presence of the pro-­‐inflammatory cytokine IL-­‐1α, the PL induced a drastic enhancement of the synthesis of the cytokines IL-­‐6 and IL-­‐8 and of NGAL, a lipocalin expressed in cells of the chondrogenic lineage. These events were controlled by the p38 MAP kinase and NF-­‐κΒ pathways. The pro-­‐inflammatory effect of the PL was a transient phenomenon. In fact, after an initial up regulation, we observed a significant reduction of the NF-­‐κΒ activity together with the repression of the inflammatory enzyme ciclooxygenase-­‐2 (COX-­‐2). Moreover, the medium of chondrocytes cultured in the contemporary presence of PL and IL-­‐1α, showed a significant enhancement of the chemoattractant activity versus untreated chondrocytes. On the whole, our findings support the concept that the platelet products have a direct beneficial effect on articular chondrocytes and at the same time could drive in sequence a trans

    Encapsulation of human articular chondrocytes into 3D hydrogel : phenotype and genotype characterization

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    This chapter is intended to provide a summary of the current materials used in cell encapsulation technology as well as methods for evaluating the performance of cells encapsulated in a polymeric matrix. In particular, it describes the experimental procedure to prepare a hydrogel matrix based on natural polymers for encapsulating and culturing human articular chondrocytes with the interest in cartilage regeneration. Protocols to evaluate the viability, proliferation, differentiation, and matrix production of embedded cells are also described and include standard protocols such as the MTT and [3H] Thymidine assays, reverse transcription polymerase chain reaction (RT-PCR) technique, histology, and immunohistochemistry analysis. The assessment of cell distribution within the 3D hydrogel construct is also described using APoTome analysis.(undefined

    Novel injectable gel (system) as a vehicle for human articular chondrocytes in cartilage tissue regeneration

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    We developed a novel injectable carrageenan/fibrin/hyaluronic acid-based hydrogel with in situ gelling properties to be seeded with chondrogenic cells and used for cartilage tissue engineering applications. We first analysed the distribution within the hydrogel construct and the phenotype of human articular chondrocytes (HACs) cultured for 3 weeks in vitro. We observed a statistically significant increase in the cell number during the first 2 weeks and maintenance of cell viability throughout the cell culture, together with the deposition/formation of a cartilage-specific extracellular matrix (ECM). Taking advantage of a new in vivo model that allows the integration between newly formed and preexisting cartilage in immunodeficient mice to be investigated, we showed that injectable hydrogel seeded with human articular chondrocytes was able to regenerate and repair an experimentally made lesion in bovine articular cartilage, thus demonstrating the potential of this novel cell delivery system for cartilage tissue engineering.The authors are grateful to Recco orthopaedic staff members for the collaboration and patients for bioptic material donation as well as to Mrs Daniela Marubbi for histological assistance. This work was supported by funds from the Italian MUR (FIRB-Tissuenet project), the European Union-funded STREP project, HIPPOCRATES (Grant No. NMP3-CT-2003-505758) and the European NoE EXPERTISSUES project (Grant No. NMP3-CT-2004-500283)

    A cartilage tissue engineering approach combining starch-polycaprolactone fibre mesh scaffolds with bovine articular chondrocytes

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    In the present work we originally tested the suitability of corn starch-polycaprolactone (SPCL) scaffolds for pursuing a cartilage tissue engineering approach. Bovine articular chondrocytes were seeded on SPCL scaffolds under dynamic conditions using spinner flasks (total of 4 scaffolds per spinner flask using cell suspensions of 0.5×106 cells/ml) and cultured under orbital agitation for a total of 6 weeks. Poly(glycolic acid) (PGA) non-woven scaffolds and bovine native articular cartilage were used as standard controls for the conducted experiments. PGA is a kind of standard in tissue engineering approaches and it was used as a control in that sense. The tissue engineered constructs were characterized at different time periods by scanning electron microscopy (SEM), hematoxylin-eosin (H&E) and toluidine blue stainings, immunolocalisation of collagen types I and II, and dimethylmethylene blue (DMB) assay for glycosaminoglycans (GAG) quantification assay. SEM results for SPCL constructs showed that the chondrocytes presented normal morphological features, with extensive cells presence at the surface of the support structures, and penetrating the scaffolds pores. These observations were further corroborated by H&E staining. Toluidine blue and immunohistochemistry exhibited extracellular matrix deposition throughout the 3D structure. Glycosaminoglycans, and collagen types I and II were detected. However, stronger staining for collagen type II was observed when compared to collagen type I. The PGA constructs presented similar features toSPCLat the end of the 6 weeks. PGA constructs exhibited higher amounts of matrix glycosaminoglycans when compared to the SPCL scaffolds. However, we also observed a lack of tissue in the central area of the PGA scaffolds. Reasons for these occurrences may include inefficient cells penetration, necrosis due to high cell densities, or necrosis related with acidic by-products degradation. Such situation was not detected in the SPCL scaffolds, indicating the much better biocompatibility of the starch based scaffolds

    The anti-bacterial iron-restriction defence mechanisms of egg white; the potential role of three lipocalin-like proteins in resistance against Salmonella

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    Salmonella enterica serovar Enteritidis (SE) is the most frequently-detected Salmonella in foodborne outbreaks in the European Union. Among such outbreaks, egg and egg products were identified as the most common vehicles of infection. Possibly, the major antibacterial property of egg white is iron restriction, which results from the presence of the iron-binding protein, ovotransferrin. To circumvent iron restriction, SE synthesise catecholate siderophores (i.e. enterobactin and salmochelin) that can chelate iron from host iron-binding proteins. Here, we highlight the role of lipocalin-like proteins found in egg white that could enhance egg-white iron restriction through sequestration of certain siderophores, including enterobactin. Indeed, it is now apparent that the egg-white lipocalin, Ex-FABP, can inhibit bacterial growth via its siderophore-binding capacity in vitro. However, it remains unclear whether ex-FABP performs such a function in egg white or during bird infection. Regarding the two other lipocalins of egg white (Cal-γ and α-1-glycoprotein), there is currently no evidence to indicate that they sequester siderophores

    Concordance of c-kit mutational status in matched primary and metastatic cutaneous canine mast cell tumors at baseline

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    BackgroundMutation analysis of proto-oncogene c-kit (c-kit) is advisable before starting treatment with tyrosine kinase inhibitors in dogs with mast cell tumor (MCT), including those with metastatic disease. Testing is usually performed on primary tumors, assuming that c-kit mutation status does not change in metastasis.Hypothesis/ObjectivesTo give an insight into the mutational processes and to make a recommendation on the use of c-kit mutational analysis in the clinical setting.AnimalsTwenty-one client-owned dogs with metastatic MCT.MethodsDogs undergoing resection or biopsy for both primary and matched metastatic MCT were prospectively enrolled. Total RNA or DNA was extracted from primary MCT and corresponding metastases. Exons 8, 9, and 11 were amplified by PCR and sequenced. Genetic features between primary MCT and metastases were compared. Their correlation with clinicopathologic features was investigated.ResultsConcordance (mutated or wild-type) of mutational status, evaluable in 21 primary and matched metastatic (20 nodal and 1 splenic) MCTs, was 100%. Three new c-kit mutations were identified. No significant correlation was detected between c-kit mutation and clinicopathologic features.Conclusions and Clinical ImportanceProto-oncogene c-kit mutational status is conserved between any primary and its matched secondary tumor, suggesting that both can be used for c-kit mutational testing. Targeted therapies might be also used to treat metastatic disease

    Novel injectable gel encapsulating human articular chondrocytes for cartilage tissue repair and regeneration

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    [Excerpt] Cartilage tissue loss, as a result of trauma, congenital disorders and diseases of joints, involving structural damage of articular cartilage surface, is a substantial clinical problem representing a major challenge for cartilage tissue engineering. The aim of our study was to evaluate the in vitro and in vivo behavior of human articular chondrocytes encapsulated within a novel carrageenan in situ injectable hydrogel for cartilage tissue engineering and regeneration. Human articular chondrocytes (Hac) were expanded using a well defined serum free medium able to support cell proliferation and differentiation with high cell chondrogenicity. [...]info:eu-repo/semantics/publishedVersio

    The employment of migrant nannies in the UK: negotiating social class in an open market for commoditised in-home care

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    Migrant women are important sources of labour in the commoditised in-home childcare sector in many regions of the UK. Jobs in this sector, which include nannies as well as au pairs, babysitters, housekeepers and mothers' helps, are often low paid and low status with pay and conditions being determined by employers' circumstances and whims. This article draws on primary data and secondary sources to illustrate the ways in which employers compare migrant nannies with British nannies and other childcare workers in terms of the social class and formal education levels of different groups, with the aim of explaining why migrants are perceived as high-quality candidates for what are often low-paid, low-status jobs. I argue that employers negotiate inter-class relations in this gendered form of employment by understanding their relationship with the migrant nannies they have employed in the context of broader global inequalities—these inequalities are then reproduced and reaffirmed in private homes and across UK culture and society
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