Veronica austriaca L. Extract and Arbutin Expand Mature Double TNF-α/IFN-γ Neutrophils in Murine Bone Marrow Pool

Plants from the Veronica genus are used across the world as traditional remedies. In the present study, extracts from the aerial part of the scarcely investigated Veronica austriaca L., collected from two habitats in Bulgaria—the Balkan Mountains (Vau-1) and the Rhodopi Mountains (Vau-2), were analyzed by nuclear magnetic resonance (NMR) spectroscopy. The secondary metabolite, arbutin, was identified as a major constituent in both extracts, and further quantified by high-performance liquid chromatography (HPLC), while catalpol, aucubin and verbascoside were detected at lower amounts. The effect of the extracts and of pure arbutin on the survival of neutrophils isolated from murine bone marrow (BM) were determined by colorimetric assay. The production of cytokines—tumor necrosis factor (TNF)-α and interferon (IFN)-γ was evaluated by flowcytometry. While Vau-1 inhibited neutrophil vitality in a dose-dependent manner, arbutin stimulated the survival of neutrophils at lower concentrations, and inhibited cell density at higher concentrations. The Vau-1 increased the level of intracellular TNF-α, while Vau-2 and arbutin failed to do so, and expanded the frequency of mature double TNF-α⁺/IFN-γ^hi neutrophils within the BM pool.

Erase-Maintain-Establish: Natural Reprogramming of the Mammalian Epigenome

The genetic information is largely identical across most cell types in a given organism but the epigenome, which controls expression of the genome, is cell type- and context-dependent. Although most mature mammalian cells appear to have a stable, heritable epigenome, a dynamic intricate process reshapes it as these cells transition from soma to germline and back again. During normal embryogenesis, primordial germ cells, of somatic origin, are set aside to become gametes. In doing so their genome is reprogrammed-that is, the epigenome of specific regions is replaced in a sex-specific fashion as they terminally differentiate into oocytes or spermatocytes in the gonads. Upon union of these gametes, reprogramming of the new organism's epigenome is initiated, which eventually leads, through pluripotent cells, to the cell lineages required for proper embryonic development to a sexually mature adult. This never-ending cycle of birth and rebirth is accomplished through methylation and demethylation of specific genomic sites within the gametes and pluripotent cells of an organism. This enigmatic process of natural epigenomic reprogramming is now being dissected in vivo, focusing on specific genomic regions-that is, imprinted genes and retrotransposons, where TRIM28 molecular complexes appear to guide the transition from gamete to embryo.

Making the hospital a safer place by sonochemical coating of all its textiles with antibacterial nanoparticles

The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparticles is demonstrated in the current paper. A roll-to-roll pilot installation to coat textiles was built taking into consideration the requirements of the sonochemical process. A long-run experiment was conducted in which 2500 m of fabric were coated with antibacterial ZnO nanoparticles (NPs). The metal oxide NPs were deposited from an ethanol:water solution. In this continuous process a uniform concentration of coated NPs over the length/width of the fabric was achieved. The antibacterial efficiency of the sonochemically-coated textiles was validated in a hospital environment by a reduction in the occurrence of nosocomial infections. NP-coated bed sheets, patient gowns, pillow cover, and bed covers were used by 21 patients. For comparison 16 patients used regular textiles. The clinical data indicated the reduced occurrence of hospital-acquired infections when using the metal oxide NP-coated textiles. In order to reduce the cost of the coating process and considering safety issues during manufacturing, the solvent (ethanol:water) (9:1 v:v) used for the long-run experiment, was replaced by water. Although lesser amounts of ZnO NPs were deposited on the fabric in the water-based process the antibacterial activity of the textiles was preserved due to the smaller size of the particles.

E2f6-mediated repression of the meiotic Stag3 and Smc1β genes during early embryonic development requires Ezh2 and not the de novo methyltransferase Dnmt3b

The E2f6 transcriptional repressor is an E2F-family member essential for the silencing of a group of meiosis-specific genes in somatic tissues. Although E2f6 has been shown to associate with both polycomb repressive complexes (PRC) and the methyltransferase Dnmt3b, the cross-talk between these repressive machineries during E2f6-mediated gene silencing has not been clearly demonstrated yet. In particular, it remains largely undetermined when and how E2f6 establishes repression of meiotic genes during embryonic development. We demonstrate here that the inactivation of a group of E2f6 targeted genes, including Stag3 and Smc1β, first occurs at the transition from mouse embryonic stem cells (ESCs) to epiblast stem cells (EpiSCs), which represent pre- and post-implantation stages, respectively. This process was accompanied by de novo methylation of their promoters. Of interest, despite a clear difference in DNA methylation status, E2f6 was similarly bound to the proximal promoter regions both in ESCs and EpiSCs. Neither E2f6 nor Dnmt3b overexpression in ESCs decreased meiotic gene expression or increased DNA methylation, indicating that additional factors are required for E2f6-mediated repression during the transition. When the SET domain of Ezh2, a core subunit of the PRC2 complex, was deleted, however, repression of Stag3 and Smc1β during embryoid body differentiation was largely impaired, indicating that the event required the enzymatic activity of Ezh2. In addition, repression of Stag3 and Smc1β occurred in the absence of Dnmt3b. The data presented here suggest a primary role of PRC2 in E2f6-mediated gene silencing of the meiotic genes.

Nosocomial infections in burn patients: etiology, antimicrobial resistance, means to control

The aim of our study was to determine the etiology of nosocomial infections, their changes over a period of five years (2007-2011), and the measures for control of infections and antimicrobial resistance in the Burns Clinic of the N.I. Pirogov University Multi-Profile Hospital for Active Treatment and Emergency Medicine, Sofia, Bulgaria. The medical records for all the patients and the database of the "Clinical Microbiology and Surveillance of Infections" National Information System were reviewed and analyzed to identify the microbial pathogens isolated in our burns Clinic. The three most frequent nosocomial pathogens were S. aureus, A. baumannii and P. aeruginosa. In order to control effectively nosocomial infections, a system of anti-infective and anti- microbial resistance measures has been developed and routinely implemented in our Clinic since 2008. Since 2009, thanks to this system, there has been a significant decrease in the rates of multi-resistant Staphylococcus aureus strains. Although at present the incidence of the nosocomial infections in our burns clinic is lower than in neighboring countries, several important infection control issues still need to be solved. We mainly rely on updating and strengthening the existing anti-infective system in order to control the spread of multi-drug resistant organisms, such as A. baumannii, extended spectrum beta-lactamase-producing Enterobacteriaceae, and carbapenem-resistant P. aeruginosa.

[The role of urinary tract infections in burn patients]

Patients with burns are predisposed to a variety of infectious complications, urinary tract infections inclusive. It is the aim of the study to assay the incidence rate, etiology and antibacterial sensitivity of the leading pathogens causing bacteriuria in burnt patients, and compare them with the respective characteristics of the pathogens causing wound infection in the same contingent of patients, and urinary tract infection in uro-nephrological patients. Over a five-year period, a total of 2452 urines and 4236 wound exudates from 963 patients with burns, and 8800 urines from 2908 uro-nephrological patients are studied. In 35.4 per cent of patients positivation of 29.2 per cent of the urines being examined is noted. The major causing agents producing bacteriuria in burns--E. coli (19.2%) and Proteus mirabilis (13.9%)--are similar to the ones found in uro-nephrological patients, and differ from the causing agents of wound infection (the isolates concur in 16.7 per cent of the cases only). The inference is reached that strict monitoring of burnt patients is absolutely necessary because they run a high risk of urinary infection development, most frequently caused by multiresistant hospital strains, worsening the prognosis of either of the conditions. Monotherapy prescription with broad-spectrum antibacterial agents, based on the sensitivity of isolates in vitro, is strongly recommended.