Optimized Electrophoretic Deposition of Chitosan/Mesoporous Glass Nanoparticles with Gentamicin on Titanium Implants: Enhancing Hemocompatibility and Antibacterial Activity.

Titanium-based implants have long been studied and used for applications in bone tissue engineering, thanks to their outstanding mechanical properties and appropriate biocompatibility. However, many implants struggle with osseointegration and attachment and can be vulnerable to the development of infections. In this work, we have developed a composite coating via electrophoretic deposition, which is both bioactive and antibacterial. Mesoporous bioactive glass particles with gentamicin were electrophoretically deposited onto a titanium substrate. In order to validate the hypothesis that the quantity of particles in the coatings is sufficiently high and uniform in each deposition process, an easy-to-use image processing algorithm was designed to minimize human dependence and ensure reproducible results. The addition of loaded mesoporous particles did not affect the good adhesion of the coating to the substrate although roughness was clearly enhanced. After 7 days of immersion, the composite coatings were almost dissolved and released, but phosphate-related compounds started to nucleate at the surface. With a simple and low-cost technique like electrophoretic deposition, and optimized stir and suspension times, we were able to synthesize a hemocompatible coating that significantly improves the antibacterial activity when compared to the bare substrate for both Gram-positive and Gram-negative bacteria.

Controlling Hypertension through Education and Coaching in Kidney Disease (CHECK-D): protocol of a cluster randomised controlled trial.

INTRODUCTION: Chronic kidney disease (CKD) affects 30 million Americans. Early management focused on blood pressure (BP) control decreases cardiovascular morbidity and mortality. Less than 40% of patients with CKD achieve recommended BP targets due to many barriers. These barriers include a lack of understanding of the implications of their diagnosis and how to optimise their health.This cluster randomised control trial hypothesises that the combination of early primary care CKD education, and motivational interviewing (MI)-based health coach support, will improve patient behaviours aligned with BP control by increasing patient knowledge, self-efficacy and motivation. The results will aid in sustainable interventions for future patient-centric education and coaching support to improve quality and outcomes in patients with CKD stages 3-5. Outcomes in patients with CKD stages 3-5 receiving the intervention will be compared with similar patients within a control group. Continuous quality improvement (CQI) and systems methodologies will be used to optimise resource neutrality and leverage existing technology to support implementation and future dissemination. The innovative approach of this research focuses on the importance of a multidisciplinary team, including off-site patient coaching, that can intervene early in the CKD care continuum by supporting patients with education and coaching. METHODS AND ANALYSIS: We will test impact of BP control when clinician-delivered education is followed by 12 months of MI-based health coaching. We will compare outcomes in 350 patients with CKD stages 3-5 between intervention and control groups in primary care. CQI and systems methodologies will optimise education and coaching for future implementation and dissemination. ETHICS AND DISSEMINATION: This study was approved by the University of Michigan Institutional Review Boards (IRBMED) HUM00136011, HUM00150672 and SITE00000092 and the results of the study will be published on ClinicalTrials.gov, in peer-reviewed journals, as well as conference abstracts, posters and presentations. TRIAL REGISTRATION NUMBER: NCT04087798.

Correction to: Identification of two different chemosensory pathways in representatives of the genus Halomonas.

Following the publication of this article [1], the authors noticed that Fig. 3 was missing. In that figure, one of the numbers corresponding to the Halomonas chemoreceptors was missing: namely, chemoreceptor 07070. The correct version of Fig. 3 has been included in this Correction.

Identification of two different chemosensory pathways in representatives of the genus Halomonas.

BACKGROUND: Species of the genus Halomonas are salt-tolerant organisms that have a versatile metabolism and can degrade a variety of xenobiotic compounds, utilizing them as their sole carbon source. In this study, we examined the genome of a Halomonas isolate from a hydrocarbon-contaminated site to search for chemosensory genes that might be responsible for the observed chemotactic behavior of this organism as well as for other responses to environmental cues. RESULTS: Using genome-wide comparative tools, our isolate was identified as a strain of Halomonas titanicae (strain KHS3), together with two other Halomonas strains with available genomes that had not been previously identified at a species level. The search for the main components of chemosensory pathways resulted in the identification of two clusters of chemosensory genes and a total of twenty-five chemoreceptor genes. One of the gene clusters is very similar to the che cluster from Escherichia coli and, presumably, it is responsible for the chemotactic behavior towards a variety of compounds. This gene cluster is present in 47 out of 56 analyzed Halomonas strains with available genomes. A second che-like cluster includes a gene coding for a diguanylate cyclase with a phosphotransfer and two receiver domains, as well as a gene coding for a chemoreceptor with a longer cytoplasmic domain than the other twenty-four. This seemingly independent pathway resembles the wsp pathway from Pseudomonas aeruginosa although it also presents several differences in gene order and domain composition. This second chemosensory gene cluster is only present in a sub-group within the genus Halomonas. Moreover, remarkably similar gene clusters are also found in some orders of Proteobacteria phylogenetically more distant from the Oceanospirillales, suggesting the occurrence of lateral transfer events. CONCLUSIONS: Chemosensory pathways were investigated within the genus Halomonas. A canonical chemotaxis pathway, controlled by a variable number of chemoreceptors, is widespread among Halomonas species. A second chemosensory pathway of unique organization that involves some type of c-di-GMP signaling was found to be present only in one branch of the genus, as well as in other proteobacterial lineages.

Mutational Replacements at the "Glycine Hinge" of the Escherichia coli Chemoreceptor Tsr Support a Signaling Role for the C-Helix Residue.

Bacterial chemoreceptors are dimeric membrane proteins that transmit signals from a periplasmic ligand-binding domain to the interior of the cells. The highly conserved cytoplasmic domain consists of a long hairpin that in the dimer forms a four-helix coiled-coil bundle. The central region of the bundle couples changes in helix packing that occur in the membrane proximal region to the signaling tip, controlling the activity of an associated histidine kinase. This subdomain contains certain glycine residues that are postulated to form a hinge in chemoreceptors from enteric bacteria and have been largely postulated to play a role in the coupling mechanism, and/or in the formation of higher-order chemoreceptor assemblies. In this work, we directly assessed the importance of the "glycine hinge" by obtaining nonfunctional replacements at each of its positions in the Escherichia coli serine receptor Tsr and characterizing them. Our results indicate that, rather than being essential for proper receptor-receptor interaction, the "glycine hinge" residues are involved in the ability of the receptor to switch between different signaling states. Mainly, the C-helix residue G439 has a key role in shifting the equilibrium toward a kinase-activating conformation. However, we found second-site mutations that restore the chemotactic proficiency of some of the "glycine hinge" mutants, suggesting that a complete hinge is not strictly essential. Rather, glycine residues seem to favor the coupling activity that relies on some other structural features of the central subdomain.

Draft Genome Sequence of Halomonas sp. KHS3, a Polyaromatic Hydrocarbon-Chemotactic Strain.

The draft genome sequence of Halomonas sp. KHS3, isolated from seawater from Mar del Plata harbor, is reported. This strain is able to grow using aromatic compounds as a carbon source and shows strong chemotactic response toward these substrates. Genes involved in motility, chemotaxis, and degradation of aromatic hydrocarbons were identified.

Variabilidad en la determinación del estado de HER2 por inmunohistoquímica en Chile / The Chilean experience of variability in the assessment of HER2 status using immunohistochemistry

Introducción: La determinación del estado del gen HER2 en el cáncer de mama es un marcador pronóstico, predictivo y de decisión terapéutica que requiere ser realizado con una técnica exacta. Objetivo: Evaluar la variabilidad de la determinación del estado del HER2 por técnica inmunohistoquímica (IHQ) en laboratorios chilenos. Pacientes y métodos: Se analizaron 221 biopsias con cáncer de mama invasivo provenientes de 41 laboratorios nacionales para determinar el estado del HER2 por hibridación in situ fluorescente (FISH). Un total de 201 biopsias permitieron análisis. El estado del HER2 se determinó por IHQ y FISH en forma estandarizada de acuerdo con las recomendaciones de la American Society of Clinical Oncology y el College of American Pathologists. Estos resultados fueron comparados con los informes de IHQ provenientes de los diferentes laboratorios. Resultados: La variabilidad de la evaluación del estado de HER2 en laboratorios nacionales es similar a lo descrito en la literatura internacional: llega al 19,7% cuando se compara con una técnica IHQ estandarizada y alcanza el 26,9% cuando se compara con FISH. La tasa de falsos positivos en IHQ es del 15,7 y del 25,6% comparados con FISH. Conclusiones: Este estudio confirma la necesidad de que los laboratorios chilenos que realicen la determinación del estado del HER2 cuenten con una técnica IHQ validada con estrictos controles de calidad interno y externo, y que empleen procedimientos técnicos y de interpretación estandarizados según recomendaciones internacionales para una correcta decisión terapéutica(AU)

Background: HER2 gene status in breast cancer is an important prognostic marker and therefore must be assessed using an accurate technique. Objective: To assess the variability in the evaluation of HER2 status using immunohistochemistry (IHC) in Chilean laboratories. Patients and methods: We analyzed 221 biopsies of invasive breast cancer from 41 laboratories nationwide, assessing HER2 status by Fluorescent In Situ Hybridization (FISH). Analysis was possible in 201of the biopsies. The HER2 status was determined by IHC and FISH in a standardized way in accordance with the recommendations of the American Society of Clinical Oncology and the College of American Pathologists (ASCO/CAP). The results were compared with IHC reports from different laboratories. Results: The variability of the assessment of HER2 status in the 41 laboratories is similar to that reported in the literature. In comparison with standardized IHC technique, variability was 19.7% but reached 25.9% when compared to FISH. The rate of false positives in IHC is 15.7% and 25.6% when compared to FISH. Conclusions: This study confirms that, in order to make the correct therapeutic decision, the IHC technique used in the assessment of HER2 status should undergo stringent internal and external quality controls. Technical and interpretative procedures should be standardized according to international recommendations(AU)

Haloarchaeal proteases and proteolytic systems.

Proteases play key roles in many biological processes and have numerous applications in biotechnology and industry. Recent advances in the genetics, genomics and biochemistry of the halophilic Archaea provide a tremendous opportunity for understanding proteases and their function in the context of an archaeal cell. This review summarizes our current knowledge of haloarchaeal proteases and provides a reference for future research.