The low-affinity phosphate transporter PitA is dispensable for in vitro growth of Mycobacterium smegmatis

Background  

Mycobacteria have been shown to contain an apparent redundancy of high-affinity phosphate uptake systems, with two to four copies of such systems encoded in all mycobacterial genomes sequenced to date. In addition, all mycobacteria also contain at least one gene encoding the low-affinity phosphate transporter, Pit. No information is available on a Pit system from a Gram-positive microorganism, and the importance of this system in a background of multiple other phosphate transporters is unclear.     

Genomic island excisions in Bordetella petrii

Background  

Among the members of the genus Bordetella B. petrii is unique, since it is the only species isolated from the environment, while the pathogenic Bordetellae are obligately associated with host organisms. Another feature distinguishing B. petrii from the other sequenced Bordetellae is the presence of a large number of mobile genetic elements including several large genomic regions with typical characteristics of genomic islands collectively known as integrative and conjugative elements (ICEs). These elements mainly encode accessory metabolic factors enabling this bacterium to grow on a large repertoire of aromatic compounds.     

Effect of a glucose impulse on the CcpA regulon in Staphylococcus aureus

Background

A low genetic diversity in Francisella tularensis has been documented. Current DNA based genotyping methods for typing F. tularensis offer a limited and varying degree of subspecies, clade and strain level discrimination power. Whole genome sequencing is the most accurate and reliable method to identify, type and determine phylogenetic relationships among strains of a species. However, lower cost typing schemes are necessary in order to enable typing of hundreds or even thousands of isolates.

Results

We have generated a high-resolution phylogenetic tree from 40 Francisella isolates, including 13 F. tularensis subspecies holarctica (type B) strains, 26 F. tularensis subsp. tularensis (type A) strains and a single F. novicida strain. The tree was generated from global multi-strain single nucleotide polymorphism (SNP) data collected using a set of six Affymetrix GeneChip^® resequencing arrays with the non-repetitive portion of LVS (type B) as the reference sequence complemented with unique sequences of SCHU S4 (type A). Global SNP based phylogenetic clustering was able to resolve all non-related strains. The phylogenetic tree was used to guide the selection of informative SNPs specific to major nodes in the tree for development of a genotyping assay for identification of F. tularensis subspecies and clades. We designed and validated an assay that uses these SNPs to accurately genotype 39 additional F. tularensis strains as type A (A1, A2, A1a or A1b) or type B (B1 or B2).

Conclusion

Whole-genome SNP based clustering was shown to accurately identify SNPs for differentiation of F. tularensis subspecies and clades, emphasizing the potential power and utility of this methodology for selecting SNPs for typing of F. tularensis to the strain level. Additionally, whole genome sequence based SNP information gained from a representative population of strains may be used to perform evolutionary or phylogenetic comparisons of strains, or selection of unique strains for whole-genome sequencing projects.     

Regulation of callose synthase activity in situ in alamethicin-permeabilized Arabidopsis and tobacco suspension cells

Background  

The cell wall component callose is mainly synthesized at certain developmental stages and after wounding or pathogen attack. Callose synthases are membrane-bound enzymes that have been relatively well characterized in vitro using isolated membrane fractions or purified enzyme. However, little is known about their functional properties in situ, under conditions when the cell wall is intact. To allow in situ investigations of the regulation of callose synthesis, cell suspensions of Arabidopsis thaliana (Col-0), and tobacco (BY-2), were permeabilized with the channel-forming peptide alamethicin.     

Predictors of the first cardiovascular event in patients with systemic lupus erythematosus - a prospective cohort study

Introduction

Cardiovascular disease (CVD) is a major cause of premature mortality among Systemic lupus erythematosus (SLE) patients. Many studies have measured and evaluated risk factors for premature subclinical atherosclerosis, but few studies are prospective and few have evaluated risk factors for hard endpoints, i.e. clinically important cardiovascular events (CVE). We investigated the impact of traditional and lupus associated risk factors for the first ever CVE in a longitudinal cohort of SLE patients.

Methods

A total of 182 SLE patients (mean age 43.9 years) selected to be free of CVE were included. Cardiovascular and autoimmune biomarkers were measured on samples collected after overnight fasting at baseline. Clinical information was collected at baseline and at follow up. End point was the first ever CVE (ischemic heart, cerebrovascular or peripheral vascular disease or death due to CVD). Impact of baseline characteristics/biomarkers on the risk of having a first CVE was evaluated with Cox regression.

Results

Follow up was 99.5% after a mean time of 8.3 years. Twenty-four patients (13%) had a first CVE. In age-adjusted Cox regression, any positive antiphospholipid antibody (aPL), elevated markers of endothelial activation (von Willebrand factor (vWf), soluble vascular cellular adhesion molecule-1 (sVCAM-1)) and fibrinogen predicted CVEs. Of SLE manifestations, arthritis, pleuritis and previous venous occlusion were positively associated with future CVEs while thrombocytopenia was negatively associated. Among traditional risk factors only age and smoking were significant predictors. In a multivariable Cox regression model age, any positive aPL, vWf and absence of thrombocytopenia were all predictors of the first CVE.

Conclusions

In addition to age, positive aPL, biomarkers indicating increased endothelial cell activity/damage, and absence of thrombocytopenia were independent predictors of CVEs in this prospective study. Our results indicate that activation of the endothelium and the coagulation system are important features in SLE related CVD. Furthermore, we observed that the risk of CVEs seems to differ between subgroups of SLE patients.     

Detection of malingered attention deficit hyperactivity disorder

The aim of the present study was to determine whether malingering of adult attention deficit hyperactivity disorder (ADHD) can be detected using a self-report rating scale. A sample of 78 university students was allocated to three different conditions. The conditions were (a) a control group, (b) a na?ve simulation group and (c) a coached simulation group. Furthermore, 12 adult students with a diagnosed ADHD participated in the present study. Participants were administered the Brown Attention Deficit Disorder Scale for Adults. While the control group and the patient group were asked to complete the scale with accuracy, the simulation groups were requested to feign an ADHD. Statistical analysis revealed that both simulation groups were able to successfully feign an ADHD. The results indicate that self-report rating measures are not sensitive enough to allow the detection of feigned ADHD.     

Wnt5a Exhibits Layer-Specific Expression in Adult Skin,Is Upregulated in Psoriasis,and Synergizes with Type 1 Interferon

Background

Wnt5a is a member of the wingless-type patterning regulators important in pre-natal development. The expression and distribution of Wnt5a and its receptors frizzled (fzd) 3 and fzd 5 in adult human skin have not been comprehensively studied to date.

Methodology/Principal Findings

We here show that Wnt5a, fzd3, fzd5, as well as fzd6 are restricted to specific layers in normal epidermis, analogous to their zonal distribution in hair follicles, suggesting a role in adult skin differentiation. In line, Wnt5a and fzd5 are both overexpressed and re-distributed in the epidermis of psoriasis which involves disturbed keratinocyte differentiation. Functionally, Wnt5a lowers the concentration of IFN required to induce target genes, and increases the magnitude of IFN target gene induction, suggesting a molecular mechanism underlying IFN hypersensitivity in psoriasis. Finally, we identify nedd8 and the amyloid precursor APP, previously shown to be upregulated in psoriasis, as targets of synergistic IFNα/Wnt5a induction.

Conclusions/Significance

The present data (i) suggest that Wnt5a regulates epidermal differentiation even in adult skin and (ii) identify synergistic induction of type 1 IFN target genes as a novel mode of Wnt5a action. Targeting Wnt5a in the skin may reduce IFN hypersensitivity and be of therapeutical value.     

Influence of Visceral Obesity and Liver Fat on Vascular Structure and Function in Obese Subjects

Endothelial dysfunction and increased intima–media thickness (IMT) have been found in obese patients. Both regional fat distribution and liver steatosis may influence these markers of subclinical atherosclerosis. We sought to determine the interrelationships of endothelial function, carotid IMT, visceral and subcutaneous adipose tissue accumulation, and liver steatosis in severely obese subjects. In 64 severely obese patients (BMI 42.3 ± 4.3 kg/m²), we determined (i) endothelial function as flow‐mediated dilation (FMD) of the brachial artery, (ii) carotid IMT, (iii) visceral fat diameter, and (iv) degree of liver steatosis using ultrasound. FMD was associated inversely with visceral fat diameter and degree of steatosis (r = ?0.577, P < 0.0001 and r = ?0.523, P < 0.0001, respectively). Carotid IMT correlated with visceral fat mass (r = 0.343, P = 0.007) but not with liver steatosis. After adjustment for conventional cardiovascular risk factors, FMD was predicted independently by the visceral fat diameter, age, and sex (r² = 0.48, P < 0.0001), but not by the degree of liver steatosis or plasma adiponectin levels. In contrast, age and sex were the only predictors of IMT (r² = 0.33, P < 0.001). In obese patients, visceral fat diameter is a major determinant of endothelial dysfunction, independent of traditional risk factors or the degree of liver steatosis and plasma adiponectin. Measurement of visceral fat diameter by ultrasound is a novel and simple method to identify subjects with an increased risk for atherosclerosis within an obese population.