Functional State of the Motor Centers of the Lumbar Spine after Contusion (Th8-Th9) with Application of Methylprednisolone-Copolymer at the Site of Injury.

Spinal cord injuries must be treated as soon as possible. Studies of NASCIS protocols have questioned the use of methylprednisolone therapy. This study aimed to evaluate the effect of local delivery of methylprednisolone succinate in combination with a tri-block copolymer in rats with spinal cord injury. The experiments were conducted in accordance with the bioethical guidelines. We evaluated the state of the motor centers below the level of injury by assessing the amplitude of evoked motor responses in the hind limb muscles of rats during epidural stimulation. Kinematic analysis was performed to examine the stepping cycle in each rat. Trajectories of foot movements were plotted to determine the range of limb motion, maximum foot lift height, and lateral deviation of the foot in rats on the 21st day after spinal cord injury. We have shown that the local application of methylprednisolone succinate in combination with block copolymer leads to recovery of center excitability by 21 days after injury. In rats, they recovered weight-supported locomotion, directional control of walking, and balance. The proposed assessment method provides valuable information on gait disturbances following injury and can be utilized to evaluate the quality of therapeutic interventions.

Time-Dependent Effect of Sciatic Nerve Injury on Rat Plasma Lipidome.

Neuropathic pain is a condition affecting the quality of life of a substantial part of the population, but biomarkers and treatment options are still limited. While this type of pain is caused by nerve damage, in which lipids play key roles, lipidome alterations related to nerve injury remain poorly studied. Here, we assessed blood lipidome alterations in a common animal model, the rat sciatic nerve crush injury. We analyzed alterations in blood lipid abundances between seven rats with nerve injury (NI) and eight control (CL) rats in a time-course experiment. For these rats, abundances of 377 blood lipid species were assessed at three distinct time points: immediately after, two weeks, and five weeks post injury. Although we did not detect significant differences between NI and CL at the first two time points, 106 lipids were significantly altered in NI five weeks post injury. At this time point, we found increased levels of triglycerides (TGs) and lipids containing esterified palmitic acid (16:0) in the blood plasma of NI animals. Lipids containing arachidonic acid (20:4), by contrast, were significantly decreased after injury, aligning with the crucial role of arachidonic acid reported for NI. Taken together, these results indicate delayed systematic alterations in fatty acid metabolism after nerve injury, potentially reflecting nerve tissue restoration dynamics.

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.

Design and Optimization Lattice Endoprosthesis for Long Bones: Manufacturing and Clinical Experiment.

The article is devoted to the construction of lattice endoprosthesis for a long bone. Clinically, the main idea is to design a construction with the ability to improve bone growth. The article presents the algorithm for such a design. The construction should be produced by additive manufacturing. Such an approach allows using not only metallic materials but also ceramics and polymers. The algorithm is based on the influence function as a method to describe the elementary cell geometry. The elementary cell can be described by a number of parameters. The influence function maps the parameters to local stress in construction. Changing the parameters influences the stress distribution in the endoprosthesis. In the paper, a bipyramid was used as an elementary cell. Numerical studies were performed using the finite element method. As a result, manufacturing construction is described. Some problems for different orientations of growth are given. The clinical test was done and histological results were presented.

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.