Microbiome dynamics of human epidermis following skin barrier disruption

Background

Recent advances in sequencing technologies have enabled metagenomic analyses of many human body sites. Several studies have catalogued the composition of bacterial communities of the surface of human skin, mostly under static conditions in healthy volunteers. Skin injury will disturb the cutaneous homeostasis of the host tissue and its commensal microbiota, but the dynamics of this process have not been studied before. Here we analyzed the microbiota of the surface layer and the deeper layers of the stratum corneum of normal skin, and we investigated the dynamics of recolonization of skin microbiota following skin barrier disruption by tape stripping as a model of superficial injury.

Results

We observed gender differences in microbiota composition and showed that bacteria are not uniformly distributed in the stratum corneum. Phylogenetic distance analysis was employed to follow microbiota development during recolonization of injured skin. Surprisingly, the developing neo-microbiome at day 14 was more similar to that of the deeper stratum corneum layers than to the initial surface microbiome. In addition, we also observed variation in the host response towards superficial injury as assessed by the induction of antimicrobial protein expression in epidermal keratinocytes.

Conclusions

We suggest that the microbiome of the deeper layers, rather than that of the superficial skin layer, may be regarded as the host indigenous microbiome. Characterization of the skin microbiome under dynamic conditions, and the ensuing response of the microbial community and host tissue, will shed further light on the complex interaction between resident bacteria and epidermis.     

Synthesis and characterization of core-shell Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>-gold-chitosan nanostructure

Background  

Fe₃O₄-gold-chitosan core-shell nanostructure can be used in biotechnological and biomedical applications such as magnetic bioseparation, water and wastewater treatment, biodetection and bioimaging, drug delivery, and cancer treatment.     

A<Subscript>2A</Subscript> and A<Subscript>3</Subscript> adenosine receptor expression in rheumatoid arthritis: upregulation,inverse correlation with disease activity score and suppression of inflammatory cytokine and metalloproteinase release

Introduction  

The reduction of the inflammatory status represents one of the most important targets in rheumatoid arthritis (RA). A central role of A_2A and A₃ adenosine receptors (ARs) in mechanisms of inflammation has been reported in different pathologies. The primary aim of this study was to investigate the A_2A and A₃ARs and their involvement in RA progression measured by Disease Activity Score in 28 or 44 joints (DAS28 or DAS).     

Evolution of the Kdo<Subscript>2</Subscript>-lipid A biosynthesis in bacteria

Background  

Lipid A is the highly immunoreactive endotoxic center of lipopolysaccharide (LPS). It anchors the LPS into the outer membrane of most Gram-negative bacteria. Lipid A can be recognized by animal cells, triggers defense-related responses, and causes Gram-negative sepsis. The biosynthesis of Kdo₂-lipid A, the LPS substructure, involves with nine enzymatic steps.     

Reactive oxygen species are involved in regulating α<Subscript>1</Subscript>-adrenoceptor-activated vascular smooth muscle contraction

Background  

Reactive oxygen species (ROS) were shown to mediate aberrant contractility in hypertension, yet the physiological roles of ROS in vascular smooth muscle contraction have remained elusive. This study aimed to examine whether ROS regulate α₁-adrenoceptor-activated contraction by altering myosin phosphatase activities.     

Factors driving refinery CO<Subscript>2</Subscript> intensity,with allocation into products

Background and scope  

Attempts to develop adequate allocation methods for CO₂ emissions from petroleum products have been reported in the literature. The common features in those studies are the use of energy, mass, and/or market prices as parameters to allocate the emissions to individual products. The crude barrel is changing, as are refinery complexities and the severity of conversion to gasoline or diesel leading to changes in the emissions intensity of refining. This paper estimates the consequences for CO₂ emissions at refineries of allowing these parameters to vary.     

A novel approach to modelling water transport and drug diffusion through the <Emphasis Type="Italic">stratum corneum</Emphasis>

Background  

The potential of using skin as an alternative path for systemically administering active drugs has attracted considerable interest, since the creation of novel drugs capable of diffusing through the skin would provide a great step towards easily applicable -and more humane- therapeutic solutions. However, for drugs to be able to diffuse, they necessarily have to cross a permeability barrier: the stratum corneum (SC), the uppermost set of skin layers. The precise mechanism by which drugs penetrate the skin is generally thought to be diffusion of molecules through this set of layers following a "tortuous pathway" around corneocytes, i.e. impermeable dead cells.     

An effective approach for generating a three-Cys<Subscript>2</Subscript>His<Subscript>2</Subscript> zinc-finger-DNA complex model by docking

Background  

Determination of protein-DNA complex structures with both NMR and X-ray crystallography remains challenging in many cases. High Ambiguity-Driven DOCKing (HADDOCK) is an information-driven docking program that has been used to successfully model many protein-DNA complexes. However, a protein-DNA complex model whereby the protein wraps around DNA has not been reported. Defining the ambiguous interaction restraints for the classical three-Cys₂His₂ zinc-finger proteins that wrap around DNA is critical because of the complicated binding geometry. In this study, we generated a Zif268-DNA complex model using three different sets of ambiguous interaction restraints (AIRs) to study the effect of the geometric distribution on the docking and used this approach to generate a newly reported Sp1-DNA complex model.     

Inventing an arsenal: adaptive evolution and neofunctionalization of snake venom phospholipase A<Subscript>2</Subscript> genes

Background  

Gene duplication followed by functional divergence has long been hypothesized to be the main source of molecular novelty. Convincing examples of neofunctionalization, however, remain rare. Snake venom phospholipase A₂ genes are members of large multigene families with many diverse functions, thus they are excellent models to study the emergence of novel functions after gene duplications.     

Synthesis of potentially bioactive PABA-related <Emphasis Type="Italic">N</Emphasis>-(aminoalkyl)lactamic amino acids and esters via selective S<Subscript>N</Subscript>Ar reactions

Abstract  

Potentially bioactive N-(aminoalkyl)lactamic amino acids and esters were synthesized in satisfactory to good yields by S_NAr reactions of aromatic acids with N-(3-aminopropyl)lactams followed by esterification with tertiary amino alcohols. The addition–elimination S_NAr mechanism was confirmed by NMR and MS measurements.     

L<Subscript>2</Subscript>-norm multiple kernel learning and its application to biomedical data fusion

Background  

This paper introduces the notion of optimizing different norms in the dual problem of support vector machines with multiple kernels. The selection of norms yields different extensions of multiple kernel learning (MKL) such as L _∞, L ₁, and L ₂ MKL. In particular, L ₂ MKL is a novel method that leads to non-sparse optimal kernel coefficients, which is different from the sparse kernel coefficients optimized by the existing L _∞ MKL method. In real biomedical applications, L ₂ MKL may have more advantages over sparse integration method for thoroughly combining complementary information in heterogeneous data sources.     

Prospective CO<Subscript>2</Subscript> emissions from energy supplying systems: photovoltaic systems and conventional grid within Spanish frame conditions

Background, aim, and scope  

In order to assess the environmental sustainability of a novel wastewater treatment process based on power an electrochemical reactor by photovoltaic solar modules (photovoltaic solar electrochemical oxidation), a life cycle approach was considered to quantify the CO₂ equivalent (CO₂-eq.) emissions coming from the two supplying power systems to the electrochemical process: conventional grid power or photovoltaic solar power under Spain frame conditions.     

Endophytic infection modifies organic acid and mineral element accumulation by rice under Na<Subscript>2</Subscript>CO<Subscript>3</Subscript> stress

Background and aims

Saline and alkali soils severely impact plant growth. Endophyte and plant associations are known to significantly modify plant metabolism. This study reports the effects of a type of endophyte on organic acid (OA) accumulation and ionic balance in rice under Na₂CO₃ stress.

Methods

Rice seedlings with (E+) and without (E-) endophytic infection were subjected to different levels of Na₂CO₃ stress (0, 5, 10, 15, and 20 mM) for two weeks. Organic acids and mineral elements in the leaves and roots were determined.

Results

Seedlings with endophytic infection accumulated mainly citrate and fumarate, with some malate and succinate in the leaves. In the roots, accumulation of malate and fumarate was enhanced significantly by endophytic infection, while less citrate and succinate was accumulated under Na₂CO₃ stress, which suggested that leaves and roots use different mechanisms to control OA metabolism. Endophytes reduced the total Na and Na:K ratios, but increased ST values, the percent changes of other measured nutrients, Chl content, and dry weight per plant under Na₂CO₃ stress.

Conclusions

Endophytic infection plays a key role in maintaining plant growth by improving nutrient uptake and adjusting OA accumulation under Na₂CO₃ stress. The application of endophytes can enhance the resistance of rice to salinity.

     

Gum arabic modified Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles cross linked with collagen for isolation of bacteria

Background  

Multifunctional magnetic nanoparticles are important class of materials in the field of nanobiotechnology, as it is an emerging area of research for material science and molecular biology researchers. One of the various methods to obtain multifunctional nanomaterials, molecular functionalization by attaching organic functional groups to nanomagnetic materials is an important technique. Recently, functionalized magnetic nanoparticles have been demonstrated to be useful in isolation/detection of dangerous pathogens (bacteria/viruses) for human life. Iron (Fe) based material especially FePt is used in the isolation of ultralow concentrations (< 10² cfu/ml) of bacteria in less time and it has been demonstrated that van-FePt may be used as an alternative fast detection technique with respect to conventional polymerase chain reaction (PCR) method. However, still further improved demonstrations are necessary with interest to biocompatibility and green chemistry. Herein, we report the synthesis of Fe₃O₄ nanoparticles by template medication and its application for the detection/isolation of S. aureus bacteria.     

Texture analysis of cartilage T<Subscript>2</Subscript> maps: individuals with risk factors for OA have higher and more heterogeneous knee cartilage MR T<Subscript>2</Subscript> compared to normal controls - data from the osteoarthritis initiative

Introduction  

The goals of this study were (i) to compare the prevalence of focal knee abnormalities, the mean cartilage T₂ relaxation time, and the spatial distribution of cartilage magnetic resonance (MR) T₂ relaxation times between subjects with and without risk factors for Osteoarthritis (OA), (ii) to determine the relationship between MR cartilage T₂ parameters, age and cartilage morphology as determined with whole-organ magnetic resonance imaging scores (WORMS) and (iii) to assess the reproducibility of WORMS scoring and T₂ relaxation time measurements including the mean and grey level co-occurrence matrix (GLCM) texture parameters.     

[HCO<Subscript>3</Subscript><Superscript>-</Superscript>]-regulated expression and activity of soluble adenylyl cyclase in corneal endothelial and Calu-3 cells

Background  

Bicarbonate activated Soluble Adenylyl Cyclase (sAC) is a unique cytoplasmic and nuclear signaling mechanism for the generation of cAMP. HCO₃ ^- activates sAC in bovine corneal endothelial cells (BCECs), increasing [cAMP] and stimulating PKA, leading to phosphorylation of the cystic fibrosis transmembrane-conductance regulator (CFTR) and increased apical Cl^- permeability. Here, we examined whether HCO₃ ^- may also regulate the expression of sAC and thereby affect the production of cAMP upon activation by HCO₃ ^- and the stimulation of CFTR in BCECs.     

Evolution of the C<Subscript>4</Subscript> phosphoenolpyruvate carboxylase promoter of the C<Subscript>4</Subscript> species <Emphasis Type="Italic">Flaveria trinervia</Emphasis>: the role of the proximal promoter region

Background  

The key enzymes of photosynthetic carbon assimilation in C₄ plants have evolved independently several times from C₃ isoforms that were present in the C₃ ancestral species. The C₄ isoform of phosphoenolpyruvate carboxylase (PEPC), the primary CO₂-fixing enzyme of the C₄ cycle, is specifically expressed at high levels in mesophyll cells of the leaves of C₄ species. We are interested in understanding the molecular changes that are responsible for the evolution of this C₄-characteristic PEPC expression pattern, and we are using the genus Flaveria (Asteraceae) as a model system. It is known that cis-regulatory sequences for mesophyll-specific expression of the ppcA1 gene of F. trinervia (C₄) are located within a distal promoter region (DR).     

Endothelial [Ca<Superscript>2+</Superscript>]<Subscript>i</Subscript> is an integrating signal for the vascular tone in rat aortae

Background  

Although various endothelium-dependent relaxing factors (endothelial autacoids) are released upon the elevation of endothelial cytosolic free Ca²⁺ concentration (EC [Ca²⁺]_i), the quantitative relationship between EC [Ca²⁺]_i and vascular tone remains to be established. Moreover, whether the basal release of endothelial autacoids is modulated by basal EC [Ca²⁺]_i is still unclear. We assessed these issues by using a novel method that allows simultaneous recording of EC [Ca²⁺]_i and vascular displacement in dissected rat aortic segments.