Presently, PRP use in tendon and ligament injuries has several potential advantages, including faster recovery and, possibly, a reduction in recurrence, with no adverse reactions described. However, only 3 randomized clinical trials have been conducted.
Currently, there is a paucity of data supporting the use of PRP for the management of focal traumatic osteochondral defects. There is limited evidence suggesting short-term clinical benefits with the use of PRP for symptomatic osteoarthritis of the knee, but the studies published to date are of poor quality and at high risk for bias. Further high-quality comparative studies with longer follow-up are needed to ascertain whether PRP is beneficial, either alone or as an adjunct to surgical procedures, in the management of articular cartilage pathology.
We describe a novel culture method that allows for increase in the number of chondrocytes and promotes hyaline-like cartilage tissue formation in part by insulin-mediated Sox9-Col2a1 binding. The suitability of the tissue generated via this approach for use in joint repair needs to be examined in vivo.
Identifying a source of sufficient numbers of chondrocytes for cartilage tissue engineering is a major factor limiting its use clinically. Previously we demonstrated that combined coculture of passaged dedifferentiated articular chondrocytes with primary bovine chondrocytes will induce their redifferentiation. In this study we determine whether these two cell types have to be in contact, whether human chondrocytes respond similarly, and whether the ability of primary cells to influence passaged cells depends on the age of the donor. Coculture of primary and passaged bovine chondrocytes grown on filter inserts placed in the same culture well but not in direct contact resulted in the passaged cells accumulating matrix rich in proteoglycans and type II collagen. There was upregulation of type II collagen and Sox9 and decrease in type I collagen gene expression in the passaged cells, to levels not significantly different from those of primary chondrocytes. Passaged chondrocytes obtained from older animals responded similarly to cells from younger animals. Further, passaged human chondrocytes were also induced to form cartilage tissue when placed in side-by-side culture with bovine chondrocytes; these data suggest that a soluble factor(s) may be responsible for redifferentiation of passaged chondrocytes and that it is not species specific. The responsiveness of human chondrocytes to this factor(s) suggests that this approach may be suitable to overcome the problem of limited chondrocyte numbers for cartilage tissue engineering.
A source of sufficient number of cells is a major limiting factor for cartilage tissue engineering. To circumvent this problem, we developed a co-culture method to induce redifferentiation in bovine articular chondrocytes, which had undergone dedifferentiation following serial passage in monolayer culture. In this study we determine whether human osteoarthritic (OA) and non-diseased passaged dedifferentiated chondrocytes will respond similarly. Human passaged chondrocytes were co-cultured for 4 weeks with primary bovine chondrocytes and their redifferentiation status was determined. Afterwards the cells were cultured either independently or in co-culture with cryopreserved passaged cells for functional analysis. The co-culture of passaged cells with primary chondrocytes resulted in reversion of their phenotype towards articular chondrocytes, as shown by increased gene expression of type II collagen and COMP, decreased type I collagen expression and extracellular matrix formation in vitro. Furthermore, this redifferentiation was stable, as those cells not only formed hyaline-like cartilage tissue when grown on their own but also they could induce redifferentiation of passaged chondrocytes in co-culture. These data suggest that it may be possible to use autologous chondrocytes obtained from osteoarthritic cartilage to form tissue suitable to use for cartilage repair.
Research addressing the organ shortage in the USA has examined multiple factors influencing one's decision to become an organ donor. One of these research lines addresses media coverage of organ donation. The present investigation seeks to advance this research line by examining the association between organ donation media coverage and organ transplantation rates. A content analysis spanning January 1990 to December 2005 of three television networks reveals an overall positive association between coverage and transplantation rates. The implications of our findings are discussed along with recommendations for practitioners and advocates alike.
Current approaches to cartilage tissue engineering require a large number of chondrocytes. Although chondrocyte numbers can be expanded in monolayer culture, the cells dedifferentiate and unless they can be redifferentiated are not optimal to use for cartilage repair. We took advantage of the differential effect of culture conditions on the ability of passaged and primary chondrocytes to form cartilage tissue to dissect out the extracellular matrix (ECM) molecules produced and accumulated in the early stages of passaged cell cartilage tissue formation as we hypothesized that passaged bovine cells that form cartilage accumulate a pericellular matrix that differs from cells that do not form cartilage. Twice passaged bovine chondrocytes (P2) (cartilage forming), or as a control primary chondrocytes (P0) (which do not generate cartilage), were cultured on three-dimensional membrane inserts in serum-free media. P2 redifferentiation was occurring during the first 8 days as indicated by increased expression of the chondrogenic genes Sox9, collagen type II, aggrecan, and COMP, suggesting that this is an appropriate time period to examine the ECM. Mass spectrometry showed that the P2 secretome (molecules released into the media) at 1 week had higher levels of collagen types I, III, and XII, and versican while type II collagen and COMP were found at higher levels in the P0 secretome. There was increased collagen synthesis and retention by P2 cells compared to P0 cells as early as 3 days of culture. Confocal microscopy showed that types XII, III, and II collagen, aggrecan, versican, and decorin were present in the ECM of P2 cells. In contrast, collagen types I, II, and III, aggrecan, and decorin were present in the ECM of P0 cells. As primary chondrocytes grown in serum-containing media, a condition that allows for the generation of cartilage tissue in vitro, also accumulate versican and collagen XII, this study suggests that these molecules may be necessary to provide a microenvironment that supports hyaline cartilage formation. Further study is required to determine if these molecules are also accumulated by passaged human chondrocytes and their role in promoting hyaline cartilage formation.
Patients with Down's syndrome (DS) have an increased incidence of coxarthrosis which may become symptomatic with prolonged life expectancy. We present seven consecutive patients (nine hips) with DS who had primary total hip arthroplasty (THA). Average clinical and radiological follow-up was 9.9±6.4 years (range 2-22.25). Harris hip scores (HHS) improved significantly (p<0.01) from 41.1 (range 18.5-65) to 80.2 (range 67.5-91) at latest follow-up. Two patients required revision arthroplasty for stem loosening at 16 (osteolysis) and six years (trauma) following THA, respectively. Six of the THAs required a constrained liner. No dislocations or deep infections were encountered. We contend that THA is a reliable surgical intervention in patients with DS and may be performed in symptomatic patients.
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