Chondrocytes, Mesenchymal Stem Cells, and Their Combination in Articular Cartilage Regenerative Medicine.

Articular cartilage (AC) is a highly organized connective tissue lining, covering the ends of bones within articulating joints. Its highly ordered structure is essential for stable motion and provides a frictionless surface easing load transfer. AC is vulnerable to lesions and, because it is aneural and avascular, it has limited self-repair potential which often leads to osteoarthritis. To date, no fully successful treatment for osteoarthritis has been reported. Thus, the development of innovative therapeutic approaches is desperately needed. Autologous chondrocyte implantation, the only cell-based surgical intervention approved in the United States for treating cartilage defects, has limitations because of de-differentiation of articular chondrocytes (AChs) upon in vitro expansion. De-differentiation can be abated if initial populations of AChs are co-cultured with mesenchymal stem cells (MSCs), which not only undergo chondrogenesis themselves but also support chondrocyte vitality. In this review we summarize studies utilizing AChs, non-AChs, and MSCs and compare associated outcomes. Moreover, a comprehensive set of recent human studies using chondrocytes to direct MSC differentiation, MSCs to support chondrocyte re-differentiation and proliferation in co-culture environments, and exploratory animal intra- and inter-species studies are systematically reviewed and discussed in an innovative manner allowing side-by-side comparisons of protocols and outcomes. Finally, a comprehensive set of recommendations are made for future studies.

Effectiveness Evaluation of Skin Covers against Intravascular Brachytherapy Sources Using VARSKIN3 Code.

BACKGROUND AND OBJECTIVE: The most common intravascular brachytherapy sources include (32)P, (188)Re, (106)Rh and (90)Sr/(90)Y. In this research, skin absorbed dose for different covering materials in dealing with these sources were evaluated and the best covering material for skin protection and reduction of absorbed dose by radiation staff was recognized and recommended. METHOD: Four materials including polyethylene, cotton and two different kinds of plastic were proposed as skin covers and skin absorbed dose at different depths for each kind of the materials was calculated separately using the VARSKIN3 code. RESULTS: The results suggested that for all sources, skin absorbed dose was minimized when using polyethylene. Considering this material as skin cover, maximum and minimum doses at skin surface were related to (90)Sr/(90)Y and (106)Rh, respectively. CONCLUSION: polyethylene was found the most effective cover in reducing skin dose and protecting the skin. Furthermore, proper agreement between the results of VARSKIN3 and other experimental measurements indicated that VRASKIN3 is a powerful tool for skin dose calculations when working with beta emitter sources. Therefore, it can be utilized in dealing with the issue of radiation protection.

Treatment of progressive cerebral sinuses thrombosis with local thrombolysis.

Cerebral venous thrombosis (CVT) is a potentially serious disease, with nonspecific clinical symptoms and an unpredictable outcome. Despite adequate anticoagulation, a patient's clinical condition can rapidly deteriorate. The aim of this study was to evaluate the efficacy of local thrombolysis in these patients. Consecutive patients with progressive cerebral venous thrombosis between October 2008 and January 2011 were enrolled prospectively. Progressive CVT was defined as the persistence of neurologic findings (headache, blurred vision, and visual field defects) despite at least four days (or 48 hours in patients with involvement of more than one sinus) on full anticoagulation therapy with heparin and development of focal neurologic deficits or cortical hemorrhage. We excluded patients with large hematomas and predisposing malignancies like leukemia. All patients underwent local thrombolysis with 30 mg recombinant tissue plasminogen activator (rtPA). Overall, 26 patients were enrolled with a mean age of 35.5 years (range 18 to 56 years). Six patients (23%) were male and twenty patients (77%) were female. The most common presenting feature was headache and the most common neurologic finding was papilledema, which was present in all patients. Eighty-five percent of women had a history of oral contraceptive pill consumption. Successful recanalization was achieved in all patients except one (96.2%). Neurological examinations and follow-up assessments were based on a modified Rankin scale (mRS). Favorable outcome and recovery was defined as a mRS score of 0-1. Follow-up assessments at the third week showed that 25 out of 26 recovered, with 18 having a mRS score of 0 and 7 with a mRS score of 1. There were no procedure-related neurological complications. Our results show that local thrombolysis is a safe and effective treatment modality for patients suffering from progressive CVT.