MOLD-SHAPED, NANOFIBER SCAFFOLD-BASED CARTILAGE ENGINEERING USING HUMAN MESENCHYMAL STEM CELLS AND BIOREACTOR

Background Mesenchymal stem cell (MSC)-based tissue engineering is a promising future alternative to autologous cartilage grafting. This study evaluates the potential of using MSCs, seeded into electrospun, biodegradable polymeric nanofibrous scaffolds, to engineer cartilage with defined dimensions and shape, similar to grafts used for subcutaneous implantation in plastic and reconstructive surgery. Materials and methods Human bone marrow derived MSCs seeded onto nanofibrous scaffolds and placed in custom-designed molds were cultured for up to 42 days in bioreactors. Chondrogenesis was induced with either transforming growth factor-β1 (TGF-β1) alone or in combination with insulin-like growth factor-I (IGF-I). Results Constructs exhibited hyaline cartilage histology with desired thickness and shape as well as favorable tissue integrity and shape retention, suggesting the presence of elastic tissue. Time-dependent increase in cartilage matrix gene expression was seen in both types of culture; at Day 42, TGF-β1/IGF-I treated cultures showed higher collagen type II and aggrecan expression. Both culture conditions showed significant time-dependent increase in sulfated glycosaminoglycan and hydroxyproline contents. TGF-β1/IGF-I treated samples were significantly stiffer; with equilibrium compressive Young’s modulus values reaching 17 kPa by Day 42. Conclusions The successful ex vivo development of geometrically defined cartilaginous construct using customized molding suggests the potential of cell-based cartilage tissue for reconstructive surgery

Ampelographic characterisation of grapevine accessions denominated 'Refošk', 'Refosco', 'Teran' and 'Terrano' (Vitis vinifera L.) from Slovenia, Croatia and Italy

Grapevines denominated 'Refošk', 'Refosco', 'Teran' and 'Terrano have been cultivated in the area of western Slovenia, north-western Croatia and north-eastern Italy for centuries. Despite historical documents reporting the longstanding tradition of grapevine cultivation and winemaking, the denomination and origin of these varieties is still questionable. The aims of this work were to study the genetic identity and relationship of the grapevine accessions denominated 'Refošk', 'Refosco', 'Teran' and 'Teranno' that have been traditionally cultivated in Slovenia, Croatia and Italy. For this purpose, 9 SSR loci were analysed to fingerprint 53 accessions with denominations or similar true-to-type morphologies of 'Refošk' and 'Teran'. The grapevine variety 'Refošk' cultivated in Slovenia and most accessions denominated 'Teran' in Croatia showed identical genotypes in all analysed SSR markers, and can therefore be used as synonyms. Five accessions showed identical genotypes to 'Refosco dal peduncolo rosso' variety, however five other genotyped accessions suggested individual profiles, and can be characterized as clonal mutants of true-to-type 'Refošk'/'Teran'. Accessions 'Sladki Teran' and 'Ref5/31' shared 56 % and 61 % of the alleles with true-to-type profiles of 'Refošk'/'Teran' and their parentage analysis strongly suggested a full-siblings relationship. Obtained results contribute to the understanding of the genetic diversity of grapevine varieties cultivated in this part of Europe

Activin A expression regulates multipotency of mesenchymal progenitor cells

INTRODUCTION. Bone marrow (BM) stroma currently represents the most common and investigated source of mesenchymal progenitor cells (MPCs); however, comparable adult progenitor or stem cells have also been isolated from a wide variety of tissues. This study aims to assess the functional similarities of MPCs from different tissues and to identify specific factor(s) related to their multipotency. METHODS. For this purpose, we directly compared MPCs isolated from different adult tissues, including bone marrow, tonsil, muscle, and dental pulp. We first examined and compared proliferation rates, immunomodulatory properties, and multidifferentiation potential of these MPCs in vitro. Next, we specifically evaluated activin A expression profile and activin A:follistatin ratio in MPCs from the four sources. RESULTS. The multidifferentiation potential of the MPCs is correlated with activin A level and/or the activin A:follistatin ratio. Interestingly, by siRNA-mediated activin A knockdown, activin A was shown to be required for the chondrogenic and osteogenic differentiation of MPCs. These findings strongly suggest that activin A has a pivotal differentiation-related role in the early stages of chondrogenesis and osteogenesis while inhibiting adipogenesis of MPCs. CONCLUSIONS. This comparative analysis of MPCs from different tissue sources also identifies bone marrow-derived MPCs as the most potent MPCs in terms of multilineage differentiation and immunosuppression, two key requirements in cell-based regenerative medicine. In addition, this study implicates the significance of activin A as a functional marker of MPC identity.National Institute of Arthritis, and Musculoskeletal and Skin Diseases; National Institutes of Health (ZO1 AR 41131, 01 DE019156-01

ІМІТАЦІЙНА МОДЕЛЬ РУХУ ПОЇЗДА В КРИВИХ МАЛОГО РАДІУСА

on the curved sections of track movement of trains as defined in the transverse vibrations of the system "train - path." The simulation model of the system is made in MATLAB language. In tight curves when driving at maximum permitted speed system works under extreme conditions, causing high stress in a carriage and in the train path. Moreover, the system operates with the limit from the viewpoint of safety. The need to quantify the wear of the railway track and trains, assess safety and comfort is particularly relevant at the present time in connection with the commissioning of tilting train, for which the transverse vibrations of the train is very significant. The simulation model also includes the ability to prepare for the measurements and experimental studies, because it allows you to get accurate results, which are expected during sea trials in normal and extreme conditions, leading to time and cost savings.Движение поездов по криволинейным участкам пути определено в виде поперечных колебаний системы «поезд – путь». Имитационная модель системы составлена на языке MATLAB. В кривых малого радиуса при движении с максимально разрешенными скоростями система работает в экстремальных условиях, вызывающих высокие напряжения как в экипаже, так и в железнодорожном пути. Кроме того, система при этом работает на пределе с точки зрения безопасности движения. Необходимость количественного определения износов железнодорожного пути и поездов, оценки безопасности движения и комфортабельности особенно актуальна в настоящее время в связи с введением в эксплуатацию поездов с наклоняемым кузовом, для которых поперечные колебания поезда весьма значительны. Имитационная модель также включает в себя возможность подготовки к измерениям и экспериментальным исследованиям, поскольку позволяет получить достаточно точные результаты, появления которых можно ожидать при проведении ходовых испытаний в нормальных или экстремальных условиях, что приводит к экономии времени и затрат.Рух поїздів по криволінійних ділянках шляху визначено у вигляді поперечних коливань системи «поїзд - шлях». Імітаційна модель системи складена на мові MATLAB. У кривих малого радіусу при русі з максимально дозволеними швидкостями система працює в екстремальних умовах, що викликають високі напруги як в екіпажі, так і в залізничній колії. Крім того, система при цьому працює на межі з точки зору безпеки руху. Необхідність кількісного визначення зносів залізничної колії і поїздів, оцінки безпеки руху і комфортабельності особливо актуальна в даний час у зв'язку з введенням в експлуатацію поїздів з нахиляються кузовом, для яких поперечні коливання поїзда досить значні. Імітаційна модель також включає в себе можливість підготовки до вимірювань і експериментальним дослідженням, оскільки дозволяє отримати досить точні результати, появи яких можна очікувати при проведенні ходових випробувань в нормальних або екстремальних умовах, що призводить до економії часу і витрат

Primary nasopharyngeal tuberculosis mimicking exacerbation of chronic rhinosinusitis

AbstractObjective:Nasopharyngeal tuberculosis is a rare condition, even in endemic tuberculosis areas. We report a case of primary nasopharyngeal tuberculosis from a non-endemic area, which presented with symptoms resembling exacerbation of previously diagnosed chronic rhinosinusitis.Case report:A 48-year-old man presented with extreme postnasal drip and an unpleasant nasal odour. Endoscopic examination revealed irregular thickening of the left lateral and posterior wall of the nasopharynx, partially covered with crusts and necrotic tissue. Histopathological study showed typical giant cell epithelioid granulomas with caseous necrosis. Direct examination after Ziehl–Neelsen staining was positive for tuberculosis. After six months of antituberculous triple therapy, endoscopic examination revealed a completely normal nasopharynx.Conclusion:To our best knowledge, this is the first published report of primary nasopharyngeal tuberculosis in a patient previously diagnosed with chronic rhinosinusitis. The difficulties in obtaining a proper diagnosis in such a case are discussed.</jats:sec

Volumetric facelift: Evaluation of rhytidectomy with alloplastic augmentation

Objectives: Facial aging occurs as a result of soft tissue atrophy and resorption of the bony skeleton, which results in a loss of soft tissue volume and laxity of the overlying skin. Volumetric augmentation is a key component of facial rejuvenation surgery, and should be considered of equal importance to soft tissue lifting. Augmentation can be accomplished with synthetic fillers, autologous grafts, soft tissue repositioning techniques, and/or alloplastic implants. Only alloplastic implants, however, provide truly long-term volumetric correction. To date, there have been no large series dealing with the complications and results of implantation performed concurrently with rhytidectomy, which we have termed volumetric rhytidectomy. We present our experience with 100 patients treated with a combination of malar and chin implants and rhytidectomy, compared to 200 patients who underwent rhytidectomy alone. Methods: The authors performed a retrospective review of patients treated with a combination of silicone malar and chin augmentation with rhytidectomy versus patients treated with rhytidectomy alone. Both groups of patients underwent close postoperative evaluation at 3 days, 1 week, 2 weeks, and 1 month. All patients were surveyed at 6 months to assess aesthetic satisfaction. Complication rates were noted and tabulated. Statistical analysis was performed to evaluate for any differences in the two groups. Results: Between 2002 and 2006, 100 patients underwent malar and chin implantation along with rhytidectomy; 200 patients underwent rhytidectomy alone. In the first group, there were a total of 6 cases in which implant removal was necessary, and 2 cases in which revision was required. There were no statistically significant differences (p \u3c 0.05) observed between the two groups with respect to major or minor hematoma, seroma, infection, sensory nerve injury, facial nerve injury, hypertrophic scarring, dehiscence, skin sloughing, or revision. Conclusions: Volumetric rhytidectomy reliably augments the malar and mental areas, allows for subtle skeletal contouring, and results in successful rejuvenation. Rhytidectomy is relatively safe to perform concurrently with silicone augmentation, and does not result in an increased complication rate as compared to rhytidectomy alone. © 2010 Annals Publishing Company. All rights reserved

Functional cartilage repair capacity of de-differentiated, chondrocyte- and mesenchymal stem cell-laden hydrogels in vitro

SummaryObjectiveThe long-term performance of cell-seeded matrix-based cartilage constructs depends on (1) the development of sufficient biomechanical properties, and (2) lateral integration with host tissues, both of which require cartilage-specific matrix deposition within the scaffold. In this study, we have examined the potential of tissue-engineered cartilage analogs developed using different cell types, i.e., mesenchymal stem cells (MSCs) vs chondrocytes and de-differentiated chondrocytes, in an established “construct in cartilage ring” model.DesignCell-laden constructs of differentiated chondrocytes, de-differentiated chondrocytes after two, five or eight population doublings, and MSCs were either implanted into a native cartilage ring immediately after fabrication (immature group) or pre-treated for 21 days in a transforming growth factor-β3 (TGF-β3) containing medium prior to implantation. After additional culture for 28 days in a serum-free, chemically defined medium, the extent of lateral integration, and biochemical and biomechanical characteristics of the implants as hybrid constructs were assessed.ResultsThe quality of integration, the amount of accumulated cartilage-specific matrix components and associated biomechanical properties were found to be highest when using differentiated chondrocytes. De-differentiation of chondrocytes negatively impacted the properties of the implants, as even two population doublings of the chondrocytes in culture significantly lowered cartilage repair capacity. In contrast, MSCs showed chondrogenic differentiation with TGF-β3 pre-treatment and superior integrational behavior.ConclusionsChondrocyte expansion and de-differentiation impaired the cell response, resulting in inferior cartilage repair in vitro. With TGF-β3 pre-treatment, MSCs were able to undergo sustained chondrogenic differentiation and exhibited superior matrix deposition and integration compared to de-differentiated chondrocytes