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Piotr Orlowski,1 Magdalena Zmigrodzka,2 Emilia Tomaszewska,3 Katarzyna Ranoszek-Soliwoda,3 Monika Czupryn,1 Malgorzata Antos-Bielska,1 Janusz Szemraj,4 Grzegorz Celichowski,3 Jaroslaw Grobelny,3 Malgorzata Krzyzowska1 1Military Institute of Hygiene and Epidemiology, Warsaw, Poland; 2Department of Pathology and Veterinary Diagnostics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences (WULS-SGGW), Warsaw, Poland; 3Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, Lodz, Poland; 4Bionanopark, Lodz, Poland Introduction: Silver nanoparticles (AgNPs) have been shown to promote wound healing and to exhibit antimicrobial properties against a broad range of bacteria. In our previous study, we prepared tannic acid (TA)-modified AgNPs showing a good toxicological profile and immunomodulatory properties useful for potential dermal applications.Methods: In this study, in vitro scratch assay, antimicrobial tests, modified lymph node assay as well as a mouse splint wound model were used to access the wound healing potential of TA-modified and unmodified AgNPs.Results: TA-modified but not unmodified AgNPs exhibited effective antibacterial activity against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli and stimulated migration of keratinocytes in vitro. The tests using the mouse splint wound model showed that TA-modified 33 and 46 nm AgNPs promoted better wound closure, epithelialization, angiogenesis and formation of the granulation tissue. Additionally, AgNPs elicited expression of VEGF-α, PDGF-β and TGF-β1 cytokines involved in wound healing more efficiently in comparison to control and TA-treated wounds. However, both the lymph node assay and the wound model showed that TA-modified AgNPs sized 13 nm can elicit strong inflammatory response not only during wound healing but also when applied to the damaged skin.Conclusion: TA-modified AgNPs sized >26 nm promote wound healing better than TA-modified or unmodified AgNPs. These findings suggest that TA-modified AgNPs sized >26 nm may have a promising application in wound management. Keywords: hydrolyzable tannin, split wound, silver, antimicrobials, inflammation, fibroblasts, monocytes

The purification and characterization of a zinc endonuclease from the Euglena gracilis nucleus were described. It binds to DNA, is nucleolytic and enhances the transcriptional rate of zinc RNA polymerase. The protein can also be isolated from zinc-deficient organisms, but it contains copper and not zinc. The copper-protein does not bind to or cleave DNA nor does it enhance transcription. Thus, copper replacement of zinc alters the function of the zincenzyme.

Background: BRAF/MEK inhibitor therapy improves outcomes in BRAF V600E- and V600K-mutated unresectable or metastatic melanoma. However, these regimens are associated with adverse events (AEs) that may lead to unnecessary drug modifications and discontinuations or potentially serious sequelae. In addition, drug-drug interactions (DDIs) may result in AEs or altered therapeutic efficacy.
., Objectives: This article presents consensus statements to guide nurses in the prevention, recognition, and management of AEs and potential DDIs associated with BRAF/MEK inhibitor therapy. 
., Methods: Members of the Melanoma Nurse Initiative reviewed the current literature and clinical experience related to AEs and DDIs associated with BRAF/MEK inhibitor therapy. 
., Findings: The care step pathways provided for select AEs represent a proactive, comprehensive nursing care plan to support optimal patient outcomes. Recommendations are also offered for preventing and managing DDIs.

We have identified functionally important regions of human interleukin-11 (hIL-11) by means of alanine-scanning mutagenesis. A total of 61 mutated forms of hIL-11 were produced in E. coli as thioredoxin fusion proteins and tested in a murine T10 plasmacytoma proliferation assay. Mutations made at several positions proximal to the hIL-11 C-terminus caused substantial reduction in biological activity. In addition a number of other mutations in this region affected either protein folding or stability. Both effects displayed a characteristic periodicity with respect to the primary sequence which suggested that residues close to the C-terminus of hIL-11 adopt a helical conformation. Mutations made proximal to the N-terminus of hIL-11 also exhibited reduced bioactivity, although no effects on protein folding or stability were observed. The N-terminal mutations with reduced activity also mapped with a periodicity suggestive of a helical conformation. We previously have proposed a four-helix bundle topology for the hIL-11 structure based on physical studies, selective chemical modifications, positions of intron/exon boundaries, limit proteolysis experiments and site-directed mutagenesis. The alanine-scanning mutagenesis data we report here provide additional support for this model.

Transcriptionally active and inactive chromatin fractions were isolated from Physarum polycephalum after depolymerization of chromatin with DNAase II or micrococcal nuclease, followed by fractionation in 5 mM-MgCl2. The active fraction of chromatin comprised up to 21% of nuclear DNA and was enriched 22-fold in the labelled nascent RNA. Both chromatin fractions were shown to have the nucleosomal structure. DNA of the active fraction of chromatin was degraded much faster with DNAase I and micrococcal nuclease than the DNA of the inactive fraction.

In a simple eukaryote Physarum polycephalum about 13% of the genome is transcribed into abundant cytoplasmic RNA as shown by S1 nuclease digestion of DNA-RNA hybrids. Mild digestion of isolated Physarum nuclei with DNase I liberates a fraction of chromatin 3.5-fold enriched in sequences hybridizing by Physarum poly(A)+ RNA. This fraction is similarly enriched in histone H4 and actin genes known to be actively transcribed in Physarum. High content (about 45%) of actively transcribed sequences in DNase-I-released fraction of Physarum chromatin makes it particularly well suited for studying the structural basis of transcriptional activation in eukaryotes.

Light treatment of nuclei of Physarum polycephalum microplasmodia with DNase I, at low MgCl2 concentration (less than or equal to 3% DNA acid solubility, 0.1 mM MgCl2) selectively solubilizes a defined fraction of chromatin, in the form of a macromolecular complex. This fraction (up to 15% of the total chromatin) contains a full complement of the core histones and a reduced amount of histone H1, and is enriched in the high-mobility-group type of proteins. It is preferentially associated with nascent RNA and RNA polymerase B actively engaged in transcription. Digestion of DNAase-I-solubilized chromatin by micrococcal nuclease releases a size-heterogeneous population of cleavage products, indicative of lack of a typical nucleosomal packaging. It is concluded that the procedure used allows the isolation of structurally and functionally distinct regions of Physarum chromatin.