Role of Imbalance of Lipid Peroxidation and Articular Cartilage Remodeling in the Pathogenesis of Early Primary and Post-Traumatic Gonarthrosis in Rats.

We studied serum indicators of LPO and antioxidant system mechanisms in nonlinear male white rats at the early stages of simulated primary knee osteoarthrosis (n=60) and posttraumatic knee osteoarthrosis (n=60) as well as in intact animals (n=20). An imbalance in the peroxidation-antioxidant system with accumulation of lipoperoxides and malondialdehyde along with a decrease in catalase and superoxide dismutase activities was revealed. Early stages of osteoarthrosis were characterized by increased production of primary and intermediate LPO products and exhaustion of the antioxidant system enzymes.

Morphological Changes in Articular Cartilage and Free-Radical Lipid Peroxidation in Rats with Posttraumatic Osteoarthrosis.

Using the rat model of posttraumatic osteoarthrosis of the knee joint induced by surgical transection of their anterior cruciate ligaments, we showed that irreversible loss of hyaluronan by the extracellular matrix of the joint cartilage tissue against the background of oxidative stress accompanied by accumulation of intermediate LPO products in blood serum and formation of thiol system incompetence was one of the key patterns of dystrophic degeneration of the cartilage tissue. Considerable metabolic shifts were associated with structural modification of the articular hyaline cartilage: its thinning and a decrease of chondrocyte density and their abnormal spatial distribution in the matrix with predominance of solitary isolated cells with signs of karyopyknosis and karyolysis.

Resistance to Antibiotics in Plankton and Biofilm Cultures of Pseudomonas aeruginosa Clinical Strains.

Biofilms formed by Pseudomonas aeruginosa strains isolated from biomaterial of patients with implant-associated infection are characterized by much higher resistance to antibiotics of various classes than plankton cultures of these strains. The concentrations of antibiotics causing the death of 90% of P. aeruginosa biofilm (MIC90) was 2-6 µg/ml for fluoroquinolones, 267-356 µg/ml for cephalosporins, and 92-215 µg/ml for amikacin, which significantly (p<0.05) differed from MIC90 for plankton cultures that did not exceed 0.8 µg/ml for fluoroquinolones, 19 µg/ml for cephalosporins, and 3 µg/ml for amikacin. The degree of the microbial biofilm maturity also affected antibiotic resistance.

[Significance of laser confocal tomography in diagnosis and monitoring of keratoconjunctivitis sicca].

UNLABELLED: Laser confocal tomography of the cornea enables studying ultrathin sections of corneal layers, which provides additional reliable information on tissue changes in keratoconjunctivitis sicca (KCS). AIM: To assess the significance of laser confocal tomography of the cornea in the diagnosis and monitoring of KCS. MATERIAL AND METHODS: We investigated 38 eyes of 30 patients with severe KCS. The patients were divided into two groups. Group 1 (15 patients, 19 eyes) was prescribed cyclosporine А 0.05% instillations 2 times daily, artificial tears, and soft contact lenses. Group 2 (15 patients, 19 eyes) received only instillations of cyclosporine А 0.05% 2 times daily and artificial tears. Besides standard ophthalmic examination, additional tests were performed, namely Schirmer's test, tear break-up time test, fluorescein eye stain test, tear osmolarity test (TearLab System, USA), and Heidelberg retinal tomography of the cornea (HRT, Heidelberg Engineering GmbH, Germany). RESULTS: HRT findings revealed a 3 times shorter epithelization period and faster recovery of corneal transparency in group 1 as compared to group 2 (1.5 and 4.5 months, respectively). There was also an evident reduction in the number of immune cells in the cornea, most pronounced in group 1 at 3 months, which is indicative of inflammation termination. CONCLUSION: The use of HRT of the cornea in KCS patients allows real-time cellular level observation of corneal changes, which together with clinical findings and diagnostic tests not only confirms the diagnosis but also determines treatment effectiveness. It has been also found that soft contact lenses accelerate epithelization of the cornea and relieve inflammation of the ocular surface in KCS patients under cyclosporine A 0.05% instillation therapy. Transparency of financial activity: the authors have no financial interest in the submitted materials and methods.