RESUMEN
A 65-year-old woman presented with right elbow pain after a fall. Imaging showed an avulsion fracture of the olecranon. The patient subsequently underwent surgery using the suture bridge technique with anchors. However, loosening was observed intraoperatively. Therefore, a McLaughlin cerclage with an artificial ligament was added, resulting in a rigid fixation. Bone union was achieved at 4 months postoperatively. At 18 months postoperatively, no limitation was observed in the range of motion of the elbow joint; the disabilities of the arm, shoulder and hand score was 0. McLaughlin cerclage with an artificial ligament provided additional fixation, demonstrating greater strength compared with suture anchors and minimizing the risk of cut-through in the osteoporotic bone. This approach offers a promising alternative for such cases by combining firm fixation with a reduced risk of complications, particularly in older patients with osteoporosis.
RESUMEN
Catalase plays a key role in protecting cells against toxic reactive oxygen species. Here we report on the cloning, purification and characterization of a catalase (KatA, DR1998) from the extremely radioresistant bacterium Deinococcus radiodurans. The size of purified D. radiodurans KatA monomer was 65 kDa while gel filtration revealed that the size of the enzyme was 240 kDa, suggesting that KatA formed a homotetramer in solution. Purified KatA displayed a final specific activity of 68,800 U/mg of protein. The catalase activity of KatA was inhibited by sodium azide, sodium cyanide and 3-amino-1,2,4-triazole. The absorption spectrum of KatA exhibited a Soret band at 408 nm. The position of the spectral peak remained unchanged following reduction of KatA with dithionite. No peroxidase activity was found for KatA. These results demonstrate that D. radiodurans KatA is a typical monofunctional heme-containing catalase. The stability of KatA with respect to H2O2 stress was superior to that of commercially available Aspergillus niger and bovine liver catalases. The relative abundance of KatA in cells in addition to the H2O2 resistance property may play a role in the survival strategy of D. radiodurans against oxidative damage.