Growth characteristics of Bacillus anthracis compared to other Bacillus spp. on the selective nutrient media Anthrax Blood Agar and Cereus Ident Agar

Anthrax Blood Agar (ABA) and Cereus Ident Agar (CEI) were evaluated as selective growth media for the isolation of Bacillus anthracis using 92 B. anthracis and 132 other Bacillus strains from 30 species. The positive predictive values for the identification of B. anthracis on ABA, CEI, and the combination of both were 72%, 71%, and 90%, respectively. Thus, less than 10% of all species were misidentified using both nutrient media. Species which might be misidentified as B. anthracis were B. cereus, B. mycoides, and B. thuringiensis. Particularly, 30% of B. weihenstephanensis strains were misidentified as B. anthracis.     

Myeloperoxidase, xanthine oxidase and superoxide dismutase in the gastric mucosa of helicobacter pylori positive and negative pediatric patients

The aim of this study was determination and comparison of the levels of myeloperoxidase (MPO), xanthine oxidase (XO), and superoxide dismutase (SOD) in gastric mucosa of children who were infected and noninfected with Helicobacter pylori (HP). The MPO, and XO enzyme activities were detected via kinetic measurement, and the MPO, XO and SOD enzyme protein levels were detected via Western blot, in antral mucosa specimens of 43 patients who underwent upper gastrointestinal endoscopy with various indications. The diagnosis of HP infection was made with a positive rapid urease test and histopathologic detection. MPO activity and enzyme protein levels were measured in 14 [8 HP (+) and 6 HP (−)], and in 9 [5 HP (+) and 4 HP (−)] while XO activity and enzyme protein levels were measured in 16 [10 HP (+) and 6 HP (−)] and in 9 [5 HP (+) and 4 HP (−)] patients, respectively. SOD protein level was detected in 13 [7 HP (+) and 6 HP (−)] patients. Of 43 patients 25 were HP (+) and 18 were HP (−). MPO activities were 75.6 ± 40.5 and 98.8 ± 44.1 U/g. protein (p = 0.302) while XO activities were 0.5 ± 0.3 and 0.4 ± 0.2 U/g. protein in HP (+) and HP (−) patients, respectively (p = 0.625). Measured enzyme protein levels of MPO, XO and SOD were found statistically indifferent in HP (+) and HP (−) patients (p = 0.327, p = 0.086, and p = 0.775, respectively). The results of this study revealed that, MPO, XO and SOD conditions in gastric mucosa alone were not affected from HP presence. That's why MPO, XO, and SOD may not have important roles in the pathogenesis of HP related gastric disease in children.     

Protein biomarker discovery and validation: the long and uncertain path to clinical utility

Better biomarkers are urgently needed to improve diagnosis, guide molecularly targeted therapy and monitor activity and therapeutic response across a wide spectrum of disease. Proteomics methods based on mass spectrometry hold special promise for the discovery of novel biomarkers that might form the foundation for new clinical blood tests, but to date their contribution to the diagnostic armamentarium has been disappointing. This is due in part to the lack of a coherent pipeline connecting marker discovery with well-established methods for validation. Advances in methods and technology now enable construction of a comprehensive biomarker pipeline from six essential process components: candidate discovery, qualification, verification, research assay optimization, biomarker validation and commercialization. Better understanding of the overall process of biomarker discovery and validation and of the challenges and strategies inherent in each phase should improve experimental study design, in turn increasing the efficiency of biomarker development and facilitating the delivery and deployment of novel clinical tests.     

Synthesis and monoamine transporter affinity of 2beta-carbomethoxy-3beta-(4'-p-substituted phenyl)-piperidine analogs of cocaine

A series of novel piperidine based analogs of cocaine was synthesized and evaluated in vitro against the three monoamine transporters to develop new potential selective SERT radiotracers. Modification of the phenyl substitution with five-membered heterocyclic groups resulted in a wide affinity and selectivity scale. Radiolabeling and mouse in vivo study was performed on the piperidine analog of ZIENT, which crossed the blood-brain barrier but failed to selectively accumulate in the regions of the brain rich in SERT.     

Single argonaute protein from Toxoplasma gondii is involved in the double-stranded RNA induced gene silencing

Here, we report the characterization of the argonaute protein from Toxoplasma gondii. This is the first report on the function of an argonaute protein with structural features overlapping between argonaute proteins of archaeal bacteria and eukaryotes. The full-length cDNA clone has an open reading frame of 1575 bp, which encodes a 524 amino acid protein with a calculated molecular weight of 58.5 kDa and an estimated isoelectric point of 9.4. This argonaute protein, called TgAgo, exhibits unique features: (i) TgAgo is smaller than reported argonaute proteins derived from higher eukaryotic organisms (i.e. Arabidopsis, human and nematodes) but has a similar size to those from archaeal bacteria (i.e. Pyrococcus furiosus and Archaeoglobus fulgidus); (ii) TgAgo contains a conserved PIWI domain and non-conserved PAZ domain; (iii) TgAgo is mainly localized in the cytoplasm; and (iv) despite its small size, TgAgo participates in the double-stranded RNA induced gene silencing. Using a transgenic parasite line, in which TgAgo expression is lowered, we showed that the expression of TgAgo is required for the double-stranded RNA induced gene silencing, RNA interference mechanism.     

Autotoxicity Against Germination and Seedling Emergence in Cistus ladanifer L

Autotoxic species are those which adversely affect their own seeds’ germination and/or seedling development. Cistus ladanifer L (labdanum or jara) has been shown to have a pattern of allelopathic behaviour against the herbs that share its habitat. The present work studied whether an autotoxic effect also exists. The aqueous solution obtained from washing jara leaves was found by itself to inhibit germination and cotyledon emergence of the species’ seeds. When these same trials were carried out in soils, autotoxicity was observed only from leaves and soils collected in winter. This was so both in soils collected away from the influence of the jaral to which was added the greatest concentration of aqueous extract prepared from the leaves, and in soils collected within the jaral, except that in the latter group of soils germination was inhibited with or without the addition of C. ladanifer extracts. This autotoxic behaviour could be involved in the species’ own population control, and would explain the scant self-regeneration within established C. ladanifer stands.     

Proteomic analysis of Brucella suis under oxygen deficiency reveals flexibility in adaptive expression of various pathways

Low oxygen tension was proposed to be one of the environmental parameters characteristic of the patho‐physiological conditions of natural infections by Brucella suis. We previously showed that various respiratory pathways may be used by B. suis in response to microaerobiosis and anaerobiosis. Here, we compare the whole proteome of B. suis exposed to such low‐oxygenated conditions to that obtained from bacteria grown under ambient air using 2‐D DIGE. Data showed that the reduction of basal metabolism was in line with low or absence of growth of B. suis. Under both microaerobiosis and anaerobiosis, glycolysis and denitrification were favored. In addition, fatty acid oxidation and possibly citrate fermentation could also contribute to energy production sufficient for survival under anaerobiosis. When oxygen availability changed and became limiting, basic metabolic processes were still functional and variability of respiratory pathways was observed to a degree unexpected for a strictly aerobic microorganism. This highly flexible respiration probably constitutes an advantage for the survival of Brucella under the restricted oxygenation conditions encountered within host tissue.     

Tarsal morphology and attachment ability of the codling moth Cydia pomonella L. (Lepidoptera, Tortricidae) to smooth surfaces

Despite several studies on the attachment ability of different insect taxa, little is known about this phenomenon in adult Lepidoptera. In this study we combined morphological and experimental analyses of tarsal adhesive devices and the attachment ability of the codling moth Cydia pomonella (L.) (Lepidoptera, Tortricidae) to smooth surfaces. Pretarsi of C. pomonella attach to smooth substrates by means of their smooth, flexible and well developed arolia. Using the centrifugal force measurement technique, friction forces of males and females were assessed on hydrophobic and hydrophilic glass surfaces. Adults of both sexes generated similar forces in spite of the noticeable difference in their body masses. That is why males showed significantly higher safety factors (attachment force divided by body weight) compared to those of females. Hydrophobicity of the substrate had no considerable effect on friction forces. For females, friction forces (sliding parallel to the substrate plane) were compared with adhesive forces (pulling off perpendicularly from the substrate plane) measured on Plexiglas surfaces. It can be concluded that the attachment system of C. pomonella is rather robust against physico-chemical properties of the substrate and is able to achieve a very good attachment on vertical and horizontal substrata.     

A machine learning approach for the identification of protein secondary structure elements from electron cryo-microscopy density maps

The accuracy of the secondary structure element (SSE) identification from volumetric protein density maps is critical for de-novo backbone structure derivation in electron cryo-microscopy (cryoEM). It is still challenging to detect the SSE automatically and accurately from the density maps at medium resolutions (～5-10 ?). We present a machine learning approach, SSELearner, to automatically identify helices and β-sheets by using the knowledge from existing volumetric maps in the Electron Microscopy Data Bank. We tested our approach using 10 simulated density maps. The averaged specificity and sensitivity for the helix detection are 94.9% and 95.8%, respectively, and those for the β-sheet detection are 86.7% and 96.4%, respectively. We have developed a secondary structure annotator, SSID, to predict the helices and β-strands from the backbone Cα trace. With the help of SSID, we tested our SSELearner using 13 experimentally derived cryo-EM density maps. The machine learning approach shows the specificity and sensitivity of 91.8% and 74.5%, respectively, for the helix detection and 85.2% and 86.5% respectively for the β-sheet detection in cryoEM maps of Electron Microscopy Data Bank. The reduced detection accuracy reveals the challenges in SSE detection when the cryoEM maps are used instead of the simulated maps. Our results suggest that it is effective to use one cryoEM map for learning to detect the SSE in another cryoEM map of similar quality.     

Lack of nitric oxide synthases increases lipoprotein immune complex deposition in the aorta and elevates plasma sphingolipid levels in lupus

Systemic lupus erythematosus (SLE) patients display impaired endothelial nitric oxide synthase (eNOS) function required for normal vasodilatation. SLE patients express increased compensatory activity of inducible nitric oxide synthase (iNOS) generating excess nitric oxide that may result in inflammation. We examined the effects of genetic deletion of NOS2 and NOS3, encoding iNOS and eNOS respectively, on accelerated vascular disease in MRL/lpr lupus mouse model. NOS2 and NOS3 knockout (KO) MRL/lpr mice had higher plasma levels of triglycerides (23% and 35%, respectively), ceramide (45% and 21%, respectively), and sphingosine 1-phosphate (S1P) (21%) compared to counterpart MRL/lpr controls. Plasma levels of the anti-inflammatory cytokine interleukin 10 (IL-10) in NOS2 and NOS3 KO MRL/lpr mice were lower (53% and 80%, respectively) than counterpart controls. Nodule-like lesions in the adventitia were detected in aortas from both NOS2 and NOS3 KO MRL/lpr mice. Immunohistochemical evaluation of the lesions revealed activated endothelial cells and lipid-laden macrophages (foam cells), elevated sphingosine kinase 1 expression, and oxidized low-density lipoprotein immune complexes (oxLDL-IC). The findings suggest that advanced vascular disease in NOS2 and NOS3 KO MRL/lpr mice maybe mediated by increased plasma triglycerides, ceramide and S1P; decreased plasma IL-10; and accumulation of oxLDL-IC in the vessel wall. The results expose possible new targets to mitigate lupus-associated complications.