Delayed wound healing in aged skin rat models after thermal injury is associated with an increased MMP-9, K6 and CD44 expression

Age-related differences in wound healing have been documented but little is known about the wound healing mechanism after burns. Our aim was to compare histological features and immunohistochemical expression of matrix metalloproteinase-9 (MMP-9), collagen IV, K6 and CD44 in the burn wound healing process in aged and young rats.     

Nitric oxide production during the osteogenic differentiation of human periodontal ligament mesenchymal stem cells

The critical tissues that require regeneration in the periodontium are of mesenchymal origin; therefore, the ability to identify, characterize and manipulate mesenchymal stem cells within the periodontium is of considerable clinical significance. In particular, recent findings suggest that periodontal ligament cells may possess many osteoblast-like properties. In the present study, periodontal ligament mesenchymal stem cells obtained from healthy volunteers were maintained in culture until confluence and then induced to osteogenic differentiation. Intracellular calcium ([Ca²⁺]_i) concentration and nitric oxide, important signalling molecules in the bone, were measured along with cell differentiation. Alkaline phosphatase activity was assayed and bone nodule-like structures were evaluated by means of morphological and histochemical analysis. Our results showed that the periodontal ligament mesenchymal stem cells underwent an in vitro osteogenic differentiation, resulting in the appearance of active osteoblast-like cells together with the formation of calcified deposits. Differentiating cells were also characterized by an increase of [Ca²⁺]_i and nitric oxide production. In conclusion, our data show a link between nitric oxide and the osteogenic differentiation of human periodontal ligament mesenchymal stem cells, thus suggesting that local reimplantation of expanded cells in conjugation with a nitric oxide donor could represent a promising method for treatment of periodontal defects.     

MR and CT arthrography of the knee

MR and CT arthrography are important imaging modalities for the assessment of the knee in certain situations. Indications for MR arthrography of the knee include assessment of the postoperative meniscus, the presence of chondral and osteochondral lesions, and the presence of intra-articular bodies. The major indication for CT arthrography is evaluating suspected internal derangement in patients who are unable to undergo MRI. In addition to reviewing the established clinical indications for MR and CT arthrography of the knee, the commonly used techniques, normal variants that can simulate disease, and the most commonly found pathologies that can be diagnosed with these modalities are discussed. Potential indications that are not currently well established in the literature including the evaluation of anterior cruciate ligament injury and autologous chondrocyte implants are examined. Where appropriate, the literature on controversial topics or diagnoses is reviewed. The use of conventional imaging versus CT and MR arthrography is also compared.     

Carbon fiber composite biomaterials in the substitution of the inferior vena cava

A new type of vascular prosthesis made of pyrolytic carbon fibres, was tested on growing pigs. Fourteen graft (8 x 30 mm) were implanted as inferior vena cava (IVC) substitutes. The blood conduits were removed 15 s, 60 min and 7, 15, 30, 60 and 120 days after implantation. Specimens were examined by light and scanning electron microscopy. Ten similar pigs underwent excision and re-implantation of 30 mm segment of IVC, and where used as controls. Carbon fibres grafts removed within 7 days after implantation were patent: at the subsequent observation times, the prosthetic segments appeared completely or partially thrombosed. Four of the 10 venous autografts failed. Shortly after implantation, a thick neointimal layer covered the inner surface of carbon grafts. This phenomenon delayed organization and neo-endothelialization of the neointima, exposing carbon segments to blood deposits.     

Longitudinal study of clinical, neurophysiological and immunological parameters in multiple sclerosis. Preliminary investigation

Thirty subjects affected with multiple sclerosis, of which 22 were female and eight male, with an average of 30 +/- 7, years were studied, for a period of 10-15 months,. clinically using Kurtzkes' report form, neurophysiologically (responses tested: VEP, BAEP, SEP, ESG) and immunologically (Rosette Et, Ea, EAC). Of the 30 cases, 19 showed poussées in the last three years and 11 were in the stabilization phase. The Kurtzke reports and the neurophysiological tests permitted an accurate assessment of lesion levels and their rate of evolution. The immunological tests showed a notable ability to differentiate between subjects with recent poussées and those in the stabilization phase presenting overall values significantly below the norm. In the follow-up, after treatments with methisoprinol, the immunological tests also revealed modifications of notable interest.