[Pavel I. Emdin: Biography without blank spots]. / Pavel Iosifovich Emdin Biografiya neirokhirurga bez belykh pyaten.

The authors present the career of Professor Pavel I. Emdin as one of the pioneers of Russian neurosurgery. Archive documents, biography and scientific articles are analyzed. The merit of Pavel I. Emdin as an organizer of national health care is «armament¼ of neuropathologists with surgical methods of treatment. He created the first in Russia Department of Nervous Diseases with clinics of neurology and neurosurgery at the Don University in Rostov-on-Don. He created the Rostov school of neurosurgeons, whose representatives continued the work of their teacher in various regions of the Soviet Union. Professor Pavel I. Emdin is a bright figure in the galaxy of Russian and Soviet neuropathologists and neurosurgeons with outstanding organizational and professional qualities regarding development of neurosurgery in our country.

Kinetics of the Growth of Enterococcus spp. Biofilm Formed by Strains Isolated from Patients with Infectious Complications after Large joint Replacements.

We studied the kinetics of growth of biofilms and plankton forms of Enterococcus spp. strains isolated in implant-associated infection of large joints. The capacity for biofilm formation by enterococci was demonstrated. The following stages of biofilm formation were revealed: biofilm formation and maturation, its degradation, and secondary dissemination. These findings extend our understanding of the wound process caused by enterococci.

Combined Effect of Ceftriaxon and Low-Frequency Ultrasound on the Viability of Staphylococcus epidermidis Cells in a Preformed Biofilm.

We studied the effect of low-frequency ultrasound on the antibacterial effect of ceftriaxone for Staphylococcus epidermidis strains isolated from biomaterial of patients with paraimplant inflammation after total replacement of large joints in the plankton and preformed biofilm forms. Low-frequency ultrasound had no antibacterial effect on the plankton S. epidermidis culture or bacterial cells in the biofilm, and combined exposure of the plankton culture to ultrasound and ceftriaxone did not modulate the antibacterial activity of ceftriaxone. The exposure of the biofilm formed by S. epidermidis strains to low-frequency ultrasound increased the sensitivity of bacterial cells to ceftriaxone in a concentration range of 5-200 µg/ml.

Features of osseous regeneration and informative value of subchondral remodeling markers in early signs of primary gonarthrosis.

Subchondral remodeling is an important pathogenic mechanism in primary gonarthrosis progress. The role of altered metabolism of osseous tissue in early signs of articular pathology remains vague, and the informative value of biochemical markers is discussible. Our research involved 103 patients (64 women and 39 men) with 0-I gonarthrosis stages and 103 healthy individuals (72 women and 28 men) of 36 to 50 years old. We measured osteocalcin, pyridinoline, type I collagen telopeptides, vitamin B metabolites, cartilage oligomeric matrix protein concentrations, determined the activity of bone alkaline phosphatase, and diagnostic significance of the markers with the ROC curve. We found the increase (p<0.0001) in bone alkaline phosphatase, type I collagen telopeptides, cartilage oligomeric matrix protein concentrations as well as osteocalcin (p<0.0002) in 0-I gonarthrosis stages as compared to the controls. The ROC curve featured 98.1 and 79.6 percent sensitivity and specificity of type I collagen telopeptides; 80.6 and 52.4 percent of osteocalcin; 99.0 and 78.6 percent of pyridinoline, respectively. These findings suggest the significant role of subchondral remodeling in the pathogenesis of early gonarthrosis stages. Pyridinoline and type I collagen telopeptides are the most informative osseous markers detectable in the serum of patients with early gonarthrosis.

Assessment of the systemic immune response in patients with inflammatory complications of large joint implants.

One of the most common reasons for the progressing of aseptic instability of implanted structures in patients with end-stage osteoarthrosis is a disorder of immunogenulatory processes of bone tissue remodeling along with chronic inflammatory response influenced by endoprosthesis wear components. This research features the specifics of systemic immune response in patients with inflammatory complications in late postoperative period after total replacements of large joints. The factor analysis enabled determining the most significant immunological mechanisms associated with the progressing of implant aseptic instability. Pathogenetically significant components involved in the formation of cellular and humoral immune responses in patients with signs of inflammatory activity in late postoperative period have been identified. Our findings can be used in designing diagnostic and prognostic criteria for systemic inflammatory response severity in preoperative monitoring of the condition of patients in need of large joint arthroplasties, and also in detecting the progress of implant aseptic instability.

Metabolism of Subchondral Bone Tissue in Posttraumatic Osteoarthrosis in Rats.

In rats with modeled posttraumatic knee osteoarthrosis, negative changes in subchondral bone metabolism were revealed: a tendency to an increase in osteocalcin concentration, a decrease in sclerostin and osteoprotegerin levels, and a significant increase in FGF-23 concentration accompanied by a slight elevation of inorganic phosphorous and significant increase in total calcium levels in comparison with the corresponding parameters in intact controls. These findings demonstrate crucial importance of structural integrity of the subchondral bone, because its protection improves the results of reconstructive therapy for local cartilage defects.

Bone Tissue Metabolism in Dynamics of Experimental Knee Osteoarthrosis Induced by Dexamethasone and Talcum.

We studied remodeling of the bone tissue in the dynamics of experimental dexamethasoneand talcum-induced knee osteoarthrosis. Disturbed osteoclastogenesis accompanied by a decrease in the production of fibroblast growth factor-23 and elevation of serum osteoprotegerin and osteocalcin were observed at the early stages of the disease. During progression of degenerative and dystrophic processes in the joint tissues, an increase in sclerostin concentrations, a decrease in osteocalcin content, and changes in the force and direction of correlations between osteoblast processes and osteoclastogenesis as well as hierarchic distribution of the dominating mechanism of subchondral remodeling were revealed.

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.

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.

Antibiotic Susceptibility of Staphylococcus aureus Plankton and Biofilm Forms Isolated in Implant-Associated Infection.

Comparison of activity of antibiotics against Staphylococcus aureus strains in their plankton form and in biofilms of varying maturity showed that the concentrations of antibiotics causing death of 90% S. aureus strains (MIC90) in their plankton form was 0.07-2.80 µg/ml and significantly (p<0.05) differed from MIC90 concentrations (3-245 µg/ml) for the strains in 24 and 48 h biofilms. MIC90 value was affected by the degree of biofilm maturity: microbial resistance in 48-h biofilms for all analyzed antibiotics was significantly (p<0.05) higher than in 24-h biofilms.

Cell Immunity in Implant-Associated Infections Caused by Biofilm-Forming Microorganisms.

High biofilm-forming capacity of Staphylococcus spp. strains isolated from biomaterial of patients with infectious complications after primary knee replacement developed within 6-12 months after surgery was experimentally demonstrated. Differential leukocyte counts and some indicators of cell immunity in these patients were compared with those in patients without purulent complications and healthy volunteers. In patients with implant-associated infection, the relative numbers of T cells (both T-helpers and T-suppressors) B cells were significantly (p<0.05) reduced, while the number of NK cells was significantly increased in comparison with the corresponding parameters in other groups. The revealed changes attest to cell immunity failure in biofilm infection.

[Professor Veniamin M. Ugriumov (To the 110th anniversary of birth)]. / Professor Veniamin Mikhailovich Ugryumov. K 110-letiyu so dnya rozhdeniya.

The authors claim four milestones of V.M. Ugriumov's career - time spent twice in Moscow, Saratov, and Leningrad. In Moscow, V.M. Ugriumov evolved as an N.N. Burdenko disciple and later as deputy director of Burdenko Neurosurgical Institute. Ugriumov's life and career in Saratov was the least studied part of his biography, and the authors used archive documents of various origins to investigate and describe them. As a result, the new scope of text and photo files was introduced into the scholarly discourse. It was in Saratov where V.M. Ugriumov designed his original neurosurgery studies, laid the groundwork for the development of Saratov neurosurgery school, and brought his management and teaching talents to light. Later, in Leningrad, Professor V.M. Ugriumov proved to be a remarkable neurosurgeon, physiologist, science, and healthcare manager.

The Effect of Azithromycin on Biofilms Formation by Pathogens of Implant-Associated Infection in Large Joints.

We studied the effect of subbacteriostatic azithromycin concentrations on the formation of microbial biofilms by Pseudomonas aeruginosa strains that caused implant-associated infection of large joints. Azithromycin in subinhibitory for planktonic cells concentrations 0.01-0.02 µg/ml stimulated biofilm formation by both clinical and reference P. aeruginosa strains, while in concentrations of 1 µg/ml and higher completely inhibited the growth of both reference and clinical plankton P. aeruginosa strains, but stimulated biofilm formation. Increasing azithromycin concentration to 10 µg/ml led to inhibition of P. aeruginosa biofilm growth.

Biofilm Formation by Gram-Negative Bacteria during Implant-Associated Infection.

Nonfermenting gram-negative bacteria and enterobacteria isolated from various biomaterials of patients of the orthopedic trauma hospital with implant-associated infection demonstrated significantly (p<0.05) higher biofilm formation capacity than the reference strains. The differences in biofilm formation kinetics were revealed: biofilm maturation and the beginning of its dispersion after 48-h incubation in enterobacteria and longer biofilm maturation phase in nonfermenting gram-negative bacteria. It was found that the strains isolated from sonication fluid have reliably (p<0.05) higher propensity to biofilm formation than bacteria isolated from aspirate and wound exudate.

Local Treatment of Local Staphylococcal Infection with Complex Preparations Based on Metal Nanoparticles in the Experiment.

Antibacterial activity of powdered preparations based on copper and silver nanoparticles was compared with activity of the reference preparation Baneocin on the model of local staphylococcal infection in white rats. The developed preparations exhibited pronounced antibacterial activity against methicillin-resistant S. epidermidis strains in vivo significantly (p<0.001) exceeding that of Baneocin, reduced microbial contamination of the wound on day 5 of study by 2 lg and more in comparison with bacterial load before treatment, and provided effective decontamination of the wound within 7-10 days.

Particularities of Bone Regeneration in Rats after Implantation of Polycaprolactone Scaffold Mineralized with Vaterite with Adsorbed Tannic Acid.

We studied the particularities of osteo- and angiogenesis in albino rats after implantation of polycaprolactone scaffolds mineralized with vaterite with adsorbed tannic acid in the femoral bone defect. It was found that the processes of angio- and osteogenesis in the bone tissue after scaffolds implantation depend on their biocompatibility. Implantation of non-biocompatible scaffolds was followed by activation of angio- and osteogenesis aimed at separation of these scaffold from surrounding tissues. Implantation of polycaprolactone/vaterite scaffolds containing tannic acid stimulated angio- and osteogenesis leading to vascularization and bone tissue formation in the matrix. This demonstrate prospects of clinical approbation of these scaffolds for stimulation of bone regeneration in traumatological and orthopedic patients.