Calpain: a new matrix proteinase?

Calpain, originally considered to be an intracellular proteinase, was demonstrated to be present extracellularly in growth cartilage of Wistar rat and also in synovial fluids of osteoarthritic patients. Proteoglycan-degrading proteolytic activities of calpain were demonstrated in vitro and in osteoarthritic synovial fluid. These data plus some recent reports of other investigators suggest that calpain-calpastatin system may have an important role in the metabolism of the extracellular matrix, although the pathways of externalization of these intracellular proteinases remain unclarified.Biomedical Reviews 1992; 1: 69-72

Evolution of Supernova Remnants Expanding out of the Dense Circumstellar Matter into the Rarefied Interstellar Medium

We carry out 3D-hydrodynamical calculations for the interaction of expanding supernova ejecta with the dense circumstellar matter (CSM) and the rarefied interstellar medium (ISM) outside. The CSM is composed of the stellar wind matter from the progenitor in its pre-supernova phase, and assumed to be axially symmetric: more matter around the equator than in the polar direction driven by rotation of the progenitor. Because of high density of the CSM, the ionization state of the shock-heated ejecta quickly becomes equilibrium with the electron temperature. When the blast wave breaks out of the CSM into the rarefied ISM, the shocked ejecta cools rapidly due to adiabatic expansion, and hence an over-ionized/recombining plasma would be left. The ejecta is reheated by the second reverse shock due to the interaction with the ISM. We calculate the emission measure of the supernova remnant (SNR) along the line of sight, and find that the over-ionized plasma appears to be bar-like with wings in the edge-on (equatorial view), while shell-like in the face-on (polar view) geometry with respect to the rotation axis. The hot gas heated by the blast wave exists in the outermost region of the SNR with a nearly complete shell, but the X-rays therefrom are too faint to be observable. Thus, depending on the viewing angle, the SNR of the over-ionized plasma would exhibit center-filled morphology in X-rays, like W49B, a mixed-morphology SNR. The bar-like structure is swept out by the second reverse shock and disappears eventually, and then the SNR becomes shell-like in both the equatorial and polar views in the later phase of the evolution.Comment: 8 pages, 9 figures, accepted for publication in PAS

Posterior cruciate ligament mediated avulsion fracture of the lateral tibial condyle: a case report

Avulsion fractures of the posterior cruciate ligament (PCL) are uncommon. On the basis of the site of damage of the PCL, hyperflexion, pretibial trauma, and hyperextension are proposed as mechanisms of PCL injuries. On the other hand, avulsion fractures of the tibial condyle are also rare. We report a PCL-mediated avulsion fracture of the lateral tibial condyle along with the tibial insertion of the PCL by extension-distraction force on the knee that has not been previously described in any study. This rare case may imply that application of an extension-distraction force to the PCL cause the avulsion fracture

Chemotherapy-Induced Oesophageal Stricture in a Child with Osteosarcoma: A Case Report

Treatment with a combination of chemotherapy and radiotherapy is known to be associated with oesophageal stricture in both children and adults with malignancies. However, oesophageal stricture resulting from chemotherapy alone is a rare complication, with few reports on it. We experienced a rare paediatric case of oesophageal stricture caused by chemotherapy for osteosarcoma of the left distal femur. After completion of the chemotherapy course, the patient showed dysphagia caused by the oesophageal stricture and underwent balloon dilatation for the oesophageal stricture. After balloon dilatation, he was able to ingest solid foods, and the oesophagus was normal without any strictures at the last follow-up (20 months after ballooning). Therefore, oesophageal stricture should be considered as a complication of treatment with chemotherapy alone in children with malignancies

Functional bracing for delayed union of a femur fracture associated with Paget's disease of the bone in an Asian patient: a case report

Paget's disease of the bone is a common metabolic bone disease in most European countries, Australia, New Zealand, and North America. Conversely, this disease is rare in Scandinavia, Asia, and Africa. In Japan, it is extremely rare, with a prevalence of 0.15/100000. Paget's disease is a localized disorder of bone remodeling. Excessive bone resorption and abnormal bone formation result in biomechanically weakened bone and predispose patients to fracture. Delayed union and non-union of fractures have been reported in patients with Paget's disease. Therefore, open reduction and internal fixation of fractures has been recommended to prevent such complications. Here we report an unusual case of a 63-year-old Asian woman with delayed union of a femur fracture secondary to Paget's disease, which was treated successfully by functional bracing

Extraskeletal Osteosarcoma of the Thigh: An Autopsy Case Report

We report a case of extraskeletal osteosarcoma (ESOS) and autopsy findings. A 35-year-old man presented with an ossified tumor in the right thigh and lung metastasis. The lung tumors continued to develop despite multiagent chemotherapy and caused death within 8 months. Autopsy revealed many secondary lesions in the lungs, especially in the left lung. Histopathologically, the primary tumor and one of the secondary tumors showed proliferation of spindle-shaped tumor cells focally forming lace-like osteoid material. Therefore, we made a definite diagnosis of ESOS