Dual-Functional Implant Based on Gellan-Xanthan Hydrogel with Diopside, BMP-2 and Lysostaphin for Bone Defect Repair and Control of Staphylococcal Infection.

A new dual-functional implant based on gellan-xanthan hydrogel with calcium-magnesium silicate ceramic diopside and recombinant lysostaphin and bone morphogenetic protein 2 (BMP-2)-ray is developed. In this composite, BMP-2 is immobilized on microparticles of diopside while lysostaphin is mixed directly into the hydrogel, providing sustained release of BMP-2 to allow gradual bone formation and rapid release of lysostaphin to eliminate infection immediately after implantation. Introduction of diopside of up to 3% (w/v) has a negligible effect on the mechanical properties of the hydrogel but provides a high sorption capacity for BMP-2. The hydrogels show good biocompatibility and antibacterial activity. Lysostaphin released from the implants over a 3 h period efficiently kills planktonic cells and completely destroys 24 h pre-formed biofilms of Staphylococcus aureus. Furthermore, in vivo experiments in a mouse model of critically-sized cranial defects infected with S. aureus show a complete lack of osteogenesis when implants contain only BMP-2, whereas, in the presence of lysostaphin, complete closure of the defect with newly formed mineralized bone tissue is observed. Thus, the new implantable gellan-xanthan hydrogel with diopside and recombinant lysostaphin and BMP-2 shows both osteogenic and antibacterial properties and represents a promising material for the treatment and/or prevention of osteomyelitis after bone trauma.

Fecal Microbiota and Diet Composition of Buryatian Horses Grazing Warm- and Cold-Season Grass Pastures.

The Buryatian horse is an ancient breed and, as an indigenous breed, they have unique adaptive abilities to use scarce pastures, graze in winter, and survive in harsh conditions with minimal human care. In this study, fecal microbiota of Buryatian horses grazing in the warm and cold seasons were investigated using NGS technology on the Illumina MiSeq platform. We hypothesized that the composition of microbial communities in the feces of horses maintained on pasture would change in the different seasons, depending on the grass availability and different plant diets. We conducted microhistological fecal studies of horse diet composition on steppe pasture. The alpha diversity analysis showed horses had a more abundant and diverse gut microbiota in summer. There were significant effects on the beta diversity of microbial families, which were clustered by the warm and cold season in a principal coordinate analysis (PCoA), with 45% of the variation explained by two principal coordinates. This clustering by season was further confirmed by the significant differences observed in the relative abundances of microbial families and genera. The obtained results can serve as an experimental substantiation for further study of the impact of pasture grasses, which have a pharmacological effect, on the diversity of the gut microbiome and horse health.

Dataset of the complete genome of Streptomyces cavourensis strain 2BA6PGT isolated from sediment from the bottom of the salt lake Verkhnee Beloe (Buryatia, Russia).

The Streptomyces cavourensis strain 2BA6PGT was isolated from sediment from the bottom of the salt lake Verkhnee Beloe (Buryatia, Russia). This strain's 7,651,223 bp complete genome has a high G + C content of 72.1% and consists of 7,069 coding sequences and 315 subsystems. The 16S ribosomal RNA of isolate 2BA6PGT was most closely related to Streptomyces cavourensis strain NBRC 13026T (98.91% identity), followed by Streptomyces bacillaris strain ATCC 15855T (95.36%), Streptomyces rhizosphaericola strain 1AS2cT (94.68%), and Streptomyces pluricolorescens strain JCM 4602T (86.75%). These comparisons were supported by pairwise comparisons using average nucleotide identity (ANI) and DNA-DNA hybridization analysis. This is the first complete genome reported on Streptomyces cavourensis isolated from sediment from the bottom of the salt lake Verkhnee Beloe. The complete genome sequence has been deposited at the NCBI GenBank with an accession number CP101140.

Microbial Community in the Permafrost Thaw Gradient in the South of the Vitim Plateau (Buryatia, Russia).

Soil microbial communities play key roles in biogeochemical cycles and greenhouse gas formation during the decomposition of the released organic matter in the thawing permafrost. The aim of our research was to assess the taxonomic prokaryotic diversity in soil-ecological niches of the Darkhituy-Khaimisan transect during the initial period of soil thawing. We investigated changes in the microbial communities present in the active layer of four sites representing distinct habitats (larch forest, birch forest, meadow steppe and thermokarst lake). We explore the relationship between the biogeochemical differences among habitats and the active layer microbial community via a spatial (across habitats, and with depth through the active layer) community survey using high-throughput Illumina sequencing. Microbial communities showed significant differences between active and frozen layers and across ecosystem types, including a high relative abundance of Alphaproteobacteria, Firmicutes, Crenarchaeota, Bacteroidota and Gemmatimonadota in the active layer and a high relative abundance of Actinobacteriota and Desulfobacterota in the frozen layer. Soil pH, temperature and moisture were the most significant parameters underlying the variations in the microbial community composition. CCA suggested that the differing environmental conditions between the four soil habitats had strong influences on microbial distribution and diversity and further explained the variability of soil microbial community structures.

Atypical Film-Forming Behavior of Soluble Tetra-3-Nitro-Substituted Copper Phthalocyanine.

Thin films of metal phthalocyanines (MPc) are known to exhibit excellent physical properties but poorly controlled morphologies. Therefore, the present work seeks to understand the film growth mechanism of a model compound for potentially usable MPc, specifically, copper tetra(3-nitro-5-tert-butyl)phthalocyanine (CuPc*). The Langmuir-Schaefer (LS) technique was applied to prepare a series of CuPc* films under different processing conditions. The film growth was examined by Brewster angle microscopy (BAM) on the water surface and small-angle X-ray scattering (SAXS) from the solid films. Neutron reflectometry (NR) measurements of the water uptake into the films and computer simulation of hydrated CuPc* were performed to substantiate an idea of colloidal MPc-water aggregates as nanoscale precursors of smooth solid films. This idea appears fruitful in terms of materials chemistry.

Efficacy and safety of quercetin and polyvinylpyrrolidone in treatment of patients with newly diagnosed destructive pulmonary tuberculosis in comparison with standard antimycobacterial therapy.

OBJECTIVE/BACKGROUND: The objective/background of this work was to study the efficacy and safety of quercetin and polyvinylpyrrolidone (QP) in the treatment of patients with newly diagnosed destructive pulmonary tuberculosis in comparison with standard antimycobacterial therapy. MATERIALS AND METHODS: The study involved 124 patients aged between 20years and 70years with newly diagnosed destructive pulmonary tuberculosis. Patients were allocated to two groups. The first (control) group of patients received standard antimycobacterial and pathogenetic therapy and included 31 (25.00±3.89%) patients. The second (main) group of patients received QP therapy in addition to chemotherapy and included 93 (75.00±3.89%) patients. RESULTS: Intoxication symptoms in the second group were reduced following 1.33±0.15months, whereas in the first group intoxication symptoms were reduced following 2.64±0.20months, p<.001. CONCLUSION: Administration of QP combined with chemotherapy in patients with newly diagnosed destructive pulmonary tuberculosis resulted in a comparatively quick reduction of disease manifestation.

Morphological changes in experimental tuberculosis resulting from treatment with quercetin and polyvinylpyrrolidone.

OBJECTIVE/BACKGROUND: Morphological study of a mice of tissue necrosis stages in experimental organ-preserving tuberculosis (TB) pharmacotherapy using quercetin and polyvinylpyrrolidone (QP). METHODS: A total of 32 laboratory mice of C57BL/6JLacSto strain were used in the experiment. The animals were divided into five groups (Group 1-5), with six to seven mice in each group: Group 1, Mycobacterium tuberculosis (MBT)-uninfected mice; Group 2, MBT-infected mice; Group 3, MBT infected and treated with anti-TB preparation (ATP); Group 4, MBT infected and QP treated; and Group 5, MBT infected and treated with ATP and QP. The mice were infected through caudal vein injection with the MTB H37Rv strain. The QP preparation, which belongs to the capillary-stabilizing-remedy group, was used for the research. The ATP included isoniazid and streptomycin. Thus, the drug doses for the mice contained the following drugs: isoniazid (10%, 5mL), 45mg/kg; streptomycin (1g), 90mg/kg; and QP (0.5g), 45mg/kg of the body weight of a mouse. The medicines used in the experimental studies on the mice were applied as follows: isoniazid and streptomycin, administered intramuscularly once a day; and QP, administered intraperitoneally according to a schedule (on the 5th day after the introduction of the infection every 2h, and then every 12h; on the 6th day and 7th day two times a day every 12h). RESULTS: QP produced a strict delineation of caseous necrosis from the unaffected parts of the connective tissue with fibrosis in the center and a large number of Langerhans cells, which was not observed in the control groups without QP. The combination of QP and ATP had more pronounced effects. In MBT-infected mice, where QP was not used, unlike the group where QP was used, adipose dystrophy of hepatocytes was observed. Thus, the hepatoprotective effect of QP against TB can be suggested. CONCLUSION: Under the influence of QP, the separation of caseous necrosis of granulomas from unaffected areas begins through connective tissue with fibrotization in the central part and a large number of Langerhans cells and lymphocytes that are not observed in the control groups. The interaction of QP with anti-TB drugs shows more obvious effects: fast tendency of epithelioid cellular tubercles to fibrotization and separation of TB granulomas through connective tissue. In addition, in the control groups of animals infected with TB, in contrast to the experimental groups, fatty degeneration of hepatocytes is observed. Thus, we have shown the hepatoprotective function of QP against TB.

Efficacy and safety of quercetin and polyvinylpyrrolidone in treatment of patients with newly diagnosed destructive pulmonary tuberculosis in comparison with standard antimycobacterial therapy.

OBJECTIVE/BACKGROUND: The aim of this work was to study the efficacy and safety of quercetin and polyvinylpyrrolidone (QP) in the treatment of patients with newly diagnosed destructive pulmonary tuberculosis (TB) in comparison with standard antimycobacterial therapy. MATERIALS AND METHODS: The study involved 124 patients aged between 20years and 70years with newly diagnosed destructive pulmonary TB. Patients were allocated to two groups. The first (control) group received standard antimycobacterial and pathogenetic therapy and included 31 (25.0±3.89%) patients. The second (main) group of patients received QP therapy in addition to chemotherapy and included 93 (75.0±3.89%) patients. All patients received standard chemotherapy, consisting of oral isoniazid (0.3g), rifampicin (0.6g), pyrazinamide (2g), ethambutol (1.2g), and/or an intramuscular injection of streptomycin (1g) with a dose reduction after the intensive phase of therapy. The anti-TB drugs were procured through the centralized national supply system in Ukraine. QP was used at a dose of 0.5g in 100mL 0.9% sodium chloride solution intravenously once per day for 10days, starting on admission to hospital. RESULTS: Intoxication symptoms in the second group were reduced after 1.33±0.15months, whereas in the first group, intoxication symptoms were reduced following 2.64±0.20months (p<0.001). Moreover, respiratory symptom regression in the second group was observed after 1.43±0.30months, whereas in the first group, it was after 2.33±0.30months (p<0.05). Bacillary excretion period evaluated within 3months was reduced, as it was shown by 97.67±1.63% in the main group compared to 72.41±8.45% (p<0.05) in the control group. In addition, the period of cavity healing was reduced to 2.86±0.15months in the main group compared to 3.43±0.20months (p<0.05) in the control group. Residual radiological lung damage findings (mild or slight or even no signs) were observed in 84 (90.32±3.07%) patients in the main group versus 22 (70.97±8.15%) patients in the control group. Significant residual radiological lung damage findings were observed in nine (9.68±3.07%) patients in the main group and in nine (29.03±8.15%) patients in the control group (p<0.05). In addition, QP increased anti-TB drug tolerance by 20.42% and had an immunomodulatory effect. CONCLUSION: Administration of QP combined with chemotherapy in patients with newly diagnosed destructive pulmonary TB resulted in a rapid reduction in disease manifestation.

Morphological changes in experimental tuberculosis resulting from treatment with quercetin and polyvinylpyrrolidone.

RESEARCH OBJECTIVE: Morphological study of tissue necrosis stages in experimental organ-preserving tuberculosis pharmacotherapy using Quercetin and Polyvinylpyrrolidone (QP). BACKGROUND AND METHODS: 32 laboratory mice of C57BL/6JLacSto strain were used in the experiment. The animals were divided into five groups, six to seven mice in each: group 1- Mycobacterium tuberculosis (MBT) uninfected mice; group 2- MBT infected mice; group 3- MBT infected and treated with antituberculosis preparation (ATP); group 4- MBT infected and QP treated; group 5- MBT infected and treated with ATP and QP. The mice were infected through caudal vein injection with MTB H37Rv strain. The preparation QP, which belongs to the capillary-stabilizing-remedy group, was used for the research. The ATP were izoniazid and streptomycin. RESULTS: QP produced a strict delineation of caseous necrosis from the unaffected parts of the connective tissue with fibrosis in the center and a large number of Langerhans cells, which was not observed in the control groups without QP. The combination of QP and ATP had more pronounced effects. In MBT-infected mice, where QP was not used, unlike the group where QP was used, adipose dystrophy of hepatocytes was observed. Thus, the hepatoprotective effect of QP against TB can be suggested. CONCLUSION: QP produces a clear delineation of caseous necrosis from an uninfected tissue by connective-tissue formation, and by forming fibrotic tissue in the center of epithelioid cells that prevents further TB dissemination by enhancing TB pharmacotherapy.