Experimental studies prove that these different pathological conditions use common enzymatic pathways leading muscle atrophy. In every catabolic conditions where there is proteolyses’s increase, this one happens in association with up-regulation of two specific genes of skeletal muscle atrophy. These genes, MuRf1 (muscle ring finger-1) and MAFbx (muscle atrophy F-box), encode ubiquitin ligases. These ligases bind and mediate ubiquitination of myofibrillar proteins for subsequent degradation during muscle atrophy. The aim of our study is to obtain a better understanding of human muscle physiopathology in atrophy by use of histochemistry and immunolocalisation of MuRF-1 and MAFbx.
The demonstration that the muscle-specific proteins MAFbx and MuRF1 are upregulated in multiple pathological conditions of skeletal muscle atrophy it is critical to continue studying the cellular pathways to discover promising targets for the development of effective new treatments for skeletal muscle disease.
Forty patients with subcutaneous rupture of the Achilles tendon were enrolled in a prospective study and randomised to two groups: group A treated with open surgery with Kessler-type suture, and group B treated by percutaneous tenorraphy (Tenolig®) under ultrasound control. The follow-up included an objective and a subjective (SF-12) clinical evaluation at 4, 12 and 24 months, ultrasonography at the same time points, and isokinetic muscle performance tests at 12 months. There were no significant differences between the two groups at clinical and ultrasound evaluation except for a greater ankle circumference in group B (p<
0.01) at 12 months; peak torque and total work isokinetic tests did not differ significantly in the two groups nor between involved and uninvolved side. At 24 months data show similar clinical and ultrasonographic results with both techniques, leading us to prefer percutaneus tenorraphy under ultrasound control owing to the attendant advantages of local anaesthesia in day surgery, decreased risk of skin complications, reduced surgical time, faster functional recovery, and greater patient compliance.
Four cases are described of solitary spinal neurofibroma, a rare tumour of the spinal cord or nerve roots. Computerised tomography provided an accurate topographical definition of the tumour. Magnetic resonance imaging showed an increased T2-weighted signal and multiple areas of decreased T1- and T2-weighted signals centrally. The MR signals matched the histological examination which showed hyperplastic interfascicular connective tissue, pleomorphic cells, and tightly packed nerve fibres compressed by the surrounding loose connective tissue. Electron microscopy showed three types of cell: Schwann cells, fibroblast-like cells, and mast cells. The histological findings suggests that solitary spinal neurofibroma is a distinct pathological entity which could be diagnosed preoperatively from the MR images.
We obtained specimens of growth-plate cartilage from four patients with osteogenesis imperfecta. Light microscopy showed structural changes in the tissue and morphological changes in chondrocytes and matrix, particularly in the hypertrophic zone. There were changes in the process of calcification in the primary mineralisation zone of the cartilage. We also found histochemical changes in the matrix glycosaminoglycans (GAGs) in the zones where physiological mineralisation was disturbed and where the trabeculae were interrupted and poorly mineralised. In addition to the known molecular defects in collagen, changes in GAGs and non-collagenous proteins are important factors in the pathogenesis of the disease.
