Outcomes after arthroscopic revision surgery for anterior cruciate ligament injuries.

Background and purpose - The frequency of primary anterior cruciate ligament (ACL) reconstruction is increasing resulting in more ACL revision surgeries. Therefore, we assessed survival rates of 2 different grafts for ACL revision surgery at 1- and 5-year follow-ups, as well as physical activity levels of patients after revision surgery.Patients and methods - This is a retrospective cohort study involving 218 patients (176 males) who had revision surgery for anterior cruciate ligament injuries between 2008 and 2017 at the Clinic of Traumatology, Orthopedics and Joint Pathology Clinic (I.M. Sechenov First Moscow State Medical University). A comparison group involved 189 patients with only primary surgery. Surgical interventions were performed according to the standard procedure using bone-patellar tendon-bone (BTB) and semitendinosus/gracilis (ST/G) autografts. The results of revision surgery were assessed at 1- and 5-year follow-ups by using the Lysholm and International Knee Documentation Committee scores.Results - Malpositioned bone tunnels were found in 87/218 patients (40%). At 1 and 5 years postoperatively, the revision BTB group had significantly better results in terms of IKDC and Lysholm scores than the revision ST/G group (p = 0.03, Mann-Whitney U-test), and these results were comparable to those in the comparison group. Graft survival after revision was lower than after the primary operation. However, the survival rate of 80% is quite high and is consistent with previous findings. There were no statistically reliable differences in survival between ST/G and BTB autografts.Interpretation - The graft choice for revision ACL surgery should be decided upon before surgery based on, among other things, the state of bone tunnels, in particular their position and degree of bone resorption. Tunnel widening that exceeds 14 mm (osteolysis) would require 2-stage surgery using a BTB autograft with bone plugs because it is larger than the ST/G autograft.

Anti-biofilm and wound-healing activity of chitosan-immobilized Ficin.

Biofouling is among the key factors slowing down healing of acute and chronic wounds. Here we report both anti-biofilm and wound-healing properties of the chitosan-immobilized Ficin. The proposed chitosan-adsorption approach allowed preserving ~90% of the initial total activity of the enzyme (when using azocasein as a substrate) with stabilization factor of 4.9, and ~70% of its specific enzymatic activity. In vitro, the chitosan-immobilized Ficin degraded staphylococcal biofilms, this way increasing the efficacy of antimicrobials against biofilm-embedded bacteria. In vivo, in the presence of Ficin (either soluble or immobilized), the S.aureus-infected skin wound areas in rats reduced twofold after 4 instead of 6 days treatment. Moreover, topical application of the immobilized enzyme resulted in a 3-log reduction of S. aureus cell count on the wound surfaces in 6 days, compared to more than 10 days required to achieve the same effect in control. Additional advantages include smoother reepithelisation, and new tissue formation exhibiting collagen structure characteristics closely reminiscent of those observed in the native tissue. Taken together, our data suggest that both soluble and immobilized Ficin appear beneficial for the treatment of biofilm-associated infections, as well as speeding up wound healing and microbial decontamination.

Spatial patterns and cell surface clusters in perineuronal nets.

Perineuronal nets (PNN) ensheath GABAergic and glutamatergic synapses on neuronal cell surface in the central nervous system (CNS), have neuroprotective effect in animal models of Alzheimer disease and regulate synaptic plasticity during development and regeneration. Crucial insights were obtained recently concerning molecular composition and physiological importance of PNN but the microstructure of the network remains largely unstudied. Here we used histochemistry, fluorescent microscopy and quantitative image analysis to study the PNN structure in adult mouse and rat neurons from layers IV and VI of the somatosensory cortex. Vast majority of meshes have quadrangle, pentagon or hexagon shape with mean mesh area of 1.29µm(2) in mouse and 1.44µm(2) in rat neurons. We demonstrate two distinct patterns of chondroitin sulfate distribution within a single mesh - with uniform (nonpolar) and node-enriched (polar) distribution of the Wisteria floribunda agglutinin-positive signal. Vertices of the node-enriched pattern match better with local maxima of chondroitin sulfate density as compared to the uniform pattern. PNN is organized into clusters of meshes with distinct morphologies on the neuronal cell surface. Our findings suggest the role for the PNN microstructure in the synaptic transduction and plasticity.