These results are consistent with the idea that GAG-cytokine interactions constitute valid therapeutic targets and suggest the potential applicability of such an approach in the prevention of graft rejection.
Conditioning of the host WF rats with 950 cGy of irradiation (sublethal, myeloablative) led to high levels of MAC without GVHD. The mature T-cell content of nonirradiated donor (ACI) limbs was sufficient to induce lethal GVHD in 100% of tolerant mixed chimeric [ACI-->WF] hosts. Irradiation of donor limbs before transplantation resulted in long-term donor-specific tolerance and prevented GVHD. These data demonstrate that (1) established chimeras could be susceptible to GVHD caused by immunocompetent donor cells transferred with the hind limb, and (2) inactivating these cells with irradiation prevents GVHD and destabilization of chimerism, and permits rejection-free graft acceptance.
Aim of this study is to introduce, evaluate, and propose a basic arthroscopy training course with interactive methods as using bovine knees, joint models but mainly focusing on practices with motor skill-learning devices. This study presents the results of a skill training program which is based on "motor skill training" theory and using "bovine knees" to simulate a specific task as arthroscopy both in education and evaluation. The participants gave feedback regarding their expectations, fulfillment, and self-evaluation on the degree of their improvement levels, after which their skills were evaluated by an expert while they performed the arthroscopic procedure. During this evaluation of the task, a four-dimensional checklist which was prepared previously by the consensus of three experts was used, and a global grading of each rater was added at the end of the checklist. In this 2-day course, small group teaching sessions are integrated with active and experiential learning methods consisting of short presentations by the educators, demonstrations using joint models and audio-visual teaching material, and significant continuous feedback by the teachers during the proceedings. Participants' expectations and post-course feedback results were obtained using a brief questionnaire which involved mostly open-ended questions. The self-rating of "own basic diagnostic arthroscopy skill" on a scale of 0-10 was completed by the participants both previous to and following the course to establish a student-centered learning environment. Overall rating of the course was asked on a 1-5 (poor-excellent) Likert scale. The questioning of the participants who took part in the course during the last five terms involved a 100% feedback. The overall rating of the course was 4.36 ± 0.47 on the 1-5 scale. The majority of the participants (90%) mentioned that the course met their expectations. The most beneficial activities were accepted to be the arthroscopic procedure applications on bovine knee, repetition of the manipulations under the supervision of the trainers, continuous feedback by experienced staff, and chance for immediate correction during the procedures (35/64). Pre- and post-course self-ratings of the participants inquiring about their ability to perform an arthroscopy alone showed significant improvement (4.2 vs. 7.7 P = 0.000, paired samples t test). All participants were found to be competent in the evaluation of their diagnostic arthroscopy skills on bovine knees. To design a skill teaching course based on the needs of the trainees, focusing on basic motor skill training exercises, and using bovine knee as a simulator is a safe, inexpensive, humanistic, and replicable method that proves a foundation for basic arthroscopic skills learning prior to patient encounter.
Biomechanical, histological, and radiological properties of three different techniques of tendon lengthening - Z-plasty, modified Vulpius, and modified Baker - were investigated and compared. Sixty white female Angora rabbits (mean weight 4.1 kg, range 3.9 kg- 4.2 kg) were randomly divided into three groups: Z-plasty, V-Y plasty (modified Vulpius technique), and U-T plasty (modified Baker technique). Histopathological, radiological, and biomechanical properties were evaluated at the third and sixth postoperative week. Qualitative analysis of ultrasound examination showed that Z-plasty had the most irregular echo pattern at the third postoperative week, and had less echogenic areas at the sixth postoperative week. Histological evaluation showed that Z-plasty had significantly more formation of fibrosis and adhesion and less parallel homogeneous collagen fibres at the sixth postoperative week (p<0.05). U-T plasty had a significantly higher mean (SD) failure load (15.35 (1.89) N) than the other two methods during the third postoperative week (p<0.05). There was no significant difference in failure load between the groups at the sixth postoperative week. U-T plasty is a good alternative to Z-plasty technique for lengthening tendons, and it may be the first choice in those who need moderate lengthening of tendons and early rehabilitation because it is easy to do, heals better, and has good biomechanical properties.
Although vascularized bone and joint allotransplantation is a promising new treatment option for reconstructing large bone defects, the need for immunosuppressive agents to prevent rejection in these procedures poses a major problem. This problem stems from the fact that several of these agents can cause harmful side effects, such as alterations in bone quality and healing. Therefore, the purpose of this study was to determine what effect the commonly used immunosuppressant regimen cyclosporine A-based combination therapy has on bone quality and healing. In 10 pigs, vascularized bone allografts with skin and muscle components (osteomyocutaneous free flaps) were transplanted from size-matched donor animals. Recipient animals received oral cyclosporine A/mycophenolate mofetil/prednisone therapy for 90 days. Bone quality was studied before and after transplantation by measuring the bone's acoustic velocity and density and calculating the bone's elastic coefficient. Bone healing was assessed using radiographic analysis. Four animals were lost as a result of graft rejection or immunosuppression-related complications before the 90-day endpoint of the study. Although bone specimens taken from the six animals that completed the 90-day protocol had histological signs of rejection, they all seemed to have normal bone healing. Posttransplant bone density values were significantly decreased (p < 0.05) (1544.7 +/- 47.5 kg/m3) as compared with pretransplant values (1722.7 +/- 44.1 kg/m3). Results of the acoustic velocity and elastic coefficients measurements showed a significant decrease (p < 0.05) in posttransplant values (from 3503.0 +/- 165.1 meters/sec to 2963.0 +/- 54.6 meters/sec and from 21.6 +/- 2.2 GPa to 13.6 +/- 0.5 GPa, respectively), indicating diminished bone quality. The findings indicate that cyclosporine A/mycophenolate mofetil/prednisone combination therapy is ineffective in preventing bone rejection, that it decreases bone quality, and that it is associated with systemic toxicity, suggesting that this immunosuppressive regimen at the doses used in this study is not ideal for vascularized bone allotransplantation procedures.
Reduction of pediatric displaced supracondylar humerus fractures may be achieved easily by the posterior approach, after cutting the triceps muscle in a reverse V-shape, and fixation with two cross-pinned K-wires provides adequate stability. This procedure does not result in weakness of the triceps muscle.
A high rate of complications is associated with open reduction and internal fixation of Sanders type 4 fractures of the calcaneum. We assessed the long-term outcome of 83 Sanders type 4 comminuted intra-articular fractures of the calcaneum in 64 patients who underwent non-operative treatment between 1999 and 2005. Each fracture was treated by closed reduction and immobilisation in a long leg cast. Patients were reviewed every three months in the first year, and every six months thereafter. At each visit, the involved ankles were assessed by the American Orthopaedic Foot and Ankle Society (AOFAS) criteria. The degree of fracture healing and the presence of osteoarthritis were assessed. At a mean follow-up of 51 months (24 to 70) the mean AOFAS score was 72 (52 to 92). Osteoarthritis was scored radiologically using Graves' classification and was evident in the subtalar joints of 75 ankles (90%) on x-ray and in all ankles on CT scans, of which 20 were grade 0 or 1, 39 grade 2, and 24 grade 3. A non-operative approach to treating these fractures may be simpler, less expensive, easier to administer with fewer complications, and may be better tolerated than surgery, by many patients.
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