Solid-Phase Synthesis and In-Silico Analysis of Iron-Binding Catecholato Chelators

Siderophores are iron-complexing compounds synthesized by bacteria and fungi. They are low molecular weight compounds (500-1500 Daltons) possessing high affinity for iron(III). Since 1970 a large number of siderophores have been characterized, the majority using hydroxamate or catecholate as functional groups. The biosynthesis of siderophores is typically regulated by the iron levels of the environment where the organism is located. Because of their exclusive affinity and specificity for iron(III), natural siderophores and their synthetic derivatives have been exploited in the treatment of human iron-overload diseases, as both diagnostic and therapeutic agents. Here, solid-phase approach for the preparation of hexadentate, peptide-based tricatecholato containing peptides is described. The versatility of the synthetic method allows for the design of a common scaffolding structure whereby diverse ligands can be conjugated. With so many possibilities, a computational approach has been developed which will facilitate the identification of those peptides which are capable of providing a high affinity iron(III) binding site. This study reports an integrated computational/synthetic approach towards a rational development of peptide-based siderophores

Genome sequence of Streptomyces caatingaensis CMAA 1322, a new abiotic stress-tolerant actinomycete isolated from dried lake bed sediment in the Brazilian Caatinga Biome.

The genome sequence of the first Streptomyces species isolated from the Brazilian Caatinga is reported here. Genes related to environmental stress tolerance were prevalent and included many secondary metabolic gene clusters

Sistemática molecular de los géneros Laurencia, Osmundea y Palisada (Rhodophyta) de las Islas Canarias, basadas en la secuencia espaciadora del RUBISCO y del rDNA

The molecular systematics of Laurencia, Osmundea and Palisada (Rhodomelaceae, Ceramiales) species from the Canary Islands has been determined by analysis sequences of the ribulose,1-5, bisphosphate carboxylase (RUBISCO) spacer from the plastid genome and the internal transcribed spacers (ITS1 and ITS2) and the rDNA 5.8S coding region from the nuclear genome. Comparison of sequence data showed an identity of 72-83 % between the species. Three taxonomic group were identified that correspond to established phylogenetic taxons. Phylogenetic trees using both parsimony and maximum-likelihood methods were derived from the sequence data; the trees indicate that O. pinnatifida appears to be the most distantly related species from the Laurencia and Palisada species. The exact phylogenetic position of Laurencia sp. A (“amarilla”) need additional studies.Se aportan datos filogenéticos de algunas especies de Laurencia, Osmundea y Palisada (Rhodomelaceae, Ceramiales) de las Islas Canarias mediante el análisis de secuencias de la región espaciadora de ribulose,1-5, bisfosfato carboxilasa (RUBISCO) del genoma plastídico y las regiones espaciadoras internas (ITS1, ITS2) y de la región codificadora del rDNA en el genoma nuclear. Los tres géneros analizados, Laurencia, Osmundea y Palisada muestran las correspondientes identidades moleculares con una identidad del 72-83% entre ellas. Empleando métodos de parsimonia y máxima similitud, los correspondientes árboles filogenéticos ponen de manifiesto que O. pinnatifida es el taxon más distante entre las especies de Laurencia y Palisada analizadas. La posición exacta del taxon mencionado como Laurencia sp. A “amarilla”) precisa de estudio adicional

The Distribution of Quasars and Galaxies in Radio Color-Color and Morphology Diagrams

We positionally match the 6 cm GB6, 20 cm FIRST and NVSS, and 92 cm WENSS radio catalogs and find 16,500 matches in ~3,000 deg2 of sky. Using this unified radio database, we construct radio "color-magnitude-morphology" diagrams and find that they display a clear structure, rather than a random scatter. We propose a simple, yet powerful, method for morphological classification of radio sources based on FIRST and NVSS measurements. For a subset of matched sources, we find optical identifications using the SDSS Data Release 1 catalogs, and separate them into quasars and galaxies. Compact radio sources with flat radio spectra are dominated by quasars, while compact sources with steep spectra, and resolved radio sources, contain substantial numbers of both quasars and galaxies.Comment: 4 pages, 2 figures, to be published in the Proceedings of "Multiwavelength AGN Surveys", Cozumel, Dec 8 - 12, 200

Non-thermal escape of molecular hydrogen from Mars

We present a detailed theoretical analysis of a non-thermal escape of molecular hydrogen from Mars induced by collisions with hot atomic oxygen from martian corona. To accurately describe the energy transfer in O + H$_2(v,j)$ collisions, we performed extensive quantum-mechanical calculations of state-to-state elastic, inelastic, and reactive cross sections. The escape flux of H$_2$ molecules was evaluated using a simplified 1D column model of the martian atmosphere with realistic densities of atmospheric gases and hot oxygen production rates for the low solar activity conditions. An average density of the non-thermal escape flux of H$_2$ of $1.9\times10^5$ cm$^{-2}$s$^{-1}$ was obtained considering energetic O atoms produced in dissociative recombinations of O$_{2}^{+}$ ions. Predicted rovibrational distribution of the escaping H$_2$ was found to contain a significant fraction of higher rotational states. While the non-thermal escape rate was found to be lower than Jeans flux for H$_2$ molecules, the non-thermal escape rates of HD and D$_2$ are significantly higher than their respective Jeans rates. The accurate values of non-thermal escape fluxes of different molecular isotopes of H$_2$ may be important in analyses of evolution of the martian atmosphere. The described molecular ejection mechanism is general and expected to contribute to atmospheric escape of H$_2$ and other light molecules from planets, satellites, and exoplanetary bodies.Comment: submitted to Geophys. Res. Let

Methylated free-circulating HPP1 DNA is an early response marker in patients with metastatic colorectal cancer

Detection of methylated free-circulating DNA (mfcDNA) for hyperplastic polyposis 1 (HPP1) in blood is correlated with a poor prognosis for patients with metastatic colorectal cancers (mCRC). Here, we analyzed the plasma levels of HPP1 mfcDNA in mCRC patients treated with a combination therapy containing a fluoropyrimidine, oxaliplatin and bevacizumab to test whether HPP1 mfcDNA is a suitable prognostic and response biomarker. From 467 patients of the prospective clinical study AIO-KRK-0207, mfcDNA was isolated from plasma samples at different time points and bisulfite-treated mfcDNA was quantified using methylation specific PCR. About 337 of 467 patients had detectable levels for HPP1 mfcDNA before start of treatment. The detection was significantly correlated with poorer overall survival (OS) (HR = 1.86; 95%CI 1.37-2.53). About 2-3 weeks after the first administration of combination chemotherapy, HPP1 mfcDNA was reduced to non-detectable levels in 167 of 337 patients. These patients showed a better OS compared with patients with continued detection of HPP1 mfcDNA (HR HPP1(sample 1: pos/ sample 2: neg) vs. HPP1(neg/neg) = 1.41; 95%CI 1.00-2.01, HPP1(neg,pos/pos) vs. HPP1(neg/neg) = 2.60; 95%CI 1.86-3.64). Receiver operating characteristic analysis demonstrated that HPP1 mfcDNA discriminates well between patients who do (not) respond to therapy according to the radiological staging after 12 or 24 weeks (AUC = 0.77 or 0.71, respectively). Detection of HPP1 mfcDNA can be used as a prognostic marker and an early marker for response (as early as 3-4 weeks after start of treatment compared with radiological staging after 12 or 24 weeks) to identify patients who will likely benefit from a combination chemotherapy with bevacizumab.info:eu-repo/semantics/publishedVersio

Gut microbial co-abundance networks show specificity in inflammatory bowel disease and obesity

The gut microbiome is an ecosystem that involves complex interactions. Currently, our knowledge about the role of the gut microbiome in health and disease relies mainly on differential microbial abundance, and little is known about the role of microbial interactions in the context of human disease. Here, we construct and compare microbial co-abundance networks using 2,379 metagenomes from four human cohorts: an inflammatory bowel disease (IBD) cohort, an obese cohort and two population-based cohorts. We find that the strengths of 38.6% of species co-abundances and 64.3% of pathway co-abundances vary significantly between cohorts, with 113 species and 1,050 pathway co-abundances showing IBD-specific effects and 281 pathway co-abundances showing obesity-specific effects. We can also replicate these IBD microbial co-abundances in longitudinal data from the IBD cohort of the integrative human microbiome (iHMP-IBD) project. Our study identifies several key species and pathways in IBD and obesity and provides evidence that altered microbial abundances in disease can influence their co-abundance relationship, which expands our current knowledge regarding microbial dysbiosis in disease

Comparison of diet consumption, body composition and lipoprotein lipid values of Kuwaiti fencing players with international norms

<p>Abstract</p> <p>Background</p> <p>No published data is currently available that describes the dietary patterns or physiological profiles of athletes participating on the Kuwaiti national fencing team and its potential impact on health and physical performance. The purpose of this investigation was to: 1) collect baseline data on nutrient intake 2) collect, analyze and report baseline for body composition, plasma lipid and lipoprotein concentrations during the competitive season, 3) compare the results with the international norms, 4) and provide necessary health and nutritional information in order to enhance the athletes' performance and skills.</p> <p>Methods</p> <p>Fifteen national-class fencers 21.5 ± 2.6 years of age participated in this study. Food intake was measured using a 3-day food record. Body composition was estimated using both the BOD POD and Body Mass Index (BMI). Total blood lipid profiles and maximum oxygen consumption was measured for each of the subjects during the competitive season.</p> <p>Results</p> <p>The results of the present study showed significant differences in dietary consumption in comparison with the recommended dietary allowances (RDA). The blood lipids profile and body composition (BMI and % body fat) were in normal range in comparison with international norms However, the average VO_{2 max}value was less than the value of the other fencers.</p> <p>Conclusion</p> <p>Due to the results of the research study, a dietary regimen can be designed that would better enhance athletic performance and minimize any health risks associated with nutrition. Percent body fat and BMI will also be categorized for all players. In addition, the plasma blood tests will help to determine if any of the players have an excessive level of lipids or any blood abnormalities. The outcomes of present study will have a direct impact on the players health and therefore their skills and athletic performance.</p