2-(1H-Pyrazol-4-yl)acetic acids as CRTh2 antagonists

High throughput screening identified the pyrazole-4-acetic acid substructure as CRTh2 receptor antagonists. Optimisation of the compounds uncovered a tight SAR but also identified some low nanomolar inhibitors.     

Isolation of Candida in the blood cultures of patients admitted to the Emergency Room in a tertiary care hospital

BackgroundIn Spain, data of candidemia are limited to surveys conducted in specific areas or tertiary care centers. Also, in recent years, attention has shifted toward episodes of candidemia in non-ICU wards.AimsWe reviewed the cases of Candida isolates recovered from the blood of patients admitted to the Emergency Room (ER) in our tertiary care hospital.MethodsThe patients selected for this study had an isolation of Candida in the blood culture. All data were collected retrospectively from the clinical records of a 11-year period.ResultsCandida albicans and other species of the genus were present in 10 and 18 patients, respectively. The patients did not present different clinical features in comparison with other reports of hospitalized patients. All patients had several risk factors for candidemia. Only two patients had received previous antifungal therapy before admission. All the isolates of C. albicans, Candida glabrata and the only isolate of Candida tropicalis were susceptible to all the antifungal agents tested. Only one isolate of Candida parapsilosis was susceptible dose-dependent to fluconazole, and the only isolate of Candida metapsilosis was resistant to fluconazole.ConclusionsIt is essential to evaluate the risk factors, underlying conditions and clinical features in non-hospitalized patients in order to determine whether an empirical treatment for candidemia is appropriate.     

Kinetics of the Anti-oxidant Response to Salinity in the Halophyte Cakile maritima

The effects of NaCl stress on the activity of anti-oxidant enzymes （superoxide dismutase, catalase （CAT）, peroxidase （POD）, ascorbate peroxidase （APX）, monodehydroascorbate reductase, dehydroascorbate reductase （DHAR）, and glutathione reductase （GR））, anti-oxidant molecules （ascorbate and glutathione）, and parameters of oxidative stress （malondialdehyde （MDA）, electrolyte leakage, and H2O2 concentrations） were investigated in Cakile maritima, a halophyte frequent along the Tunisian seashore. Seedlings were grown in the presence of salt （100, 200, and 400 mmol/L NaCl）. Plants were harvested periodically over 20 days. Growth was maximal in the presence of 0-100 mmol/L NaCl. At 400 mmol/L NaCl, growth decreased significantly. The salt tolerance of C. maritima, at moderate salinities, was associated with the lowest values of the parameters indicative of oxidative stress, namely the highest activities of POD, CAT, APX, DHAR, and GR and high tissue content of ascorbate and glutathione. However, prolonged exposure to high salinity resulted in a decrease in anti-oxidant activities and high MDA content, electrolyte leakage, and H2O2 concentrations. These results suggest that anti-oxidant systems participate in the tolerance of C. maritima to moderate salinities.     

Molecular analysis of the interaction of LCMV with its cellular receptor [alpha]-dystroglycan

alpha-Dystroglycan (DG) has been identified as the cellular receptor for lymphocytic choriomeningitis virus (LCMV) and Lassa fever virus (LFV). This subunit of DG is a highly versatile cell surface molecule that provides a molecular link between the extracellular matrix (ECM) and a beta-DG transmembrane component, which interacts with the actin-based cytoskeleton. In addition, DG exhibits a complex pattern of interaction with a wide variety of ECM and cellular proteins. In the present study, we characterized the binding of LCMV to alpha-DG and addressed the role of alpha-DG-associated host-derived proteins in virus infection. We found that the COOH-terminal region of alpha-DG's first globular domain and the NH2-terminal region of the mucin-related structures of alpha-DG together form the binding site for LCMV. The virus-alpha-DG binding unlike ECM alpha-DG interactions was not dependent on divalent cations. Despite such differences in binding, LCMV and laminin-1 use, in part, an overlapping binding site on alpha-DG, and the ability of an LCMV isolate to compete with laminin-1 for receptor binding is determined by its binding affinity to alpha-DG. This competition of the virus with ECM molecules for receptor binding likely explains the recently found correlation between the affinity of LCMV binding to alpha-DG, tissue tropism, and pathological potential. LCMV strains and variants with high binding affinity to alpha-DG but not low affinity binders are able to infect CD11c+ dendritic cells, which express alpha-DG at their surface. Infection followed by dysfunction of these antigen-presenting cells contributes to immunosuppression and persistent viral infection in vivo.     

Differences in the Candida albicans antigenic expression after heat shock and infection

Heat-shock and infection induce changes in protein expression in C. albicans. To investigate if these alterations induce changes in antigenicity, we have compared the reactivity mediated by IgA antibodies of protein extracts from a strain of C. albicans and the same strain recovered from an infected animal, both at 24 degrees C and 37 degrees C. The antigenic variability was detected mainly in antigens recognized by salivary IgA. Antigens of 223, 205, 180 and 140 kDa were over-expressed in both strains at 37 degrees C, indicating that variations due to heat shock were present before and after infection. The antigens were characterized as mannoproteins located at the outer side of the cell wall. An antigen of 61 kDa was also detected in which the expression decreased significantly after infection This was independent of heat shock.     

GARBAN: genomic analysis and rapid biological annotation of cDNA microarray and proteomic data

SUMMARY: Genomic Analysis and Rapid Biological ANnotation (GARBAN) is a new tool that provides an integrated framework to analyze simultaneously and compare multiple data sets derived from microarray or proteomic experiments. It carries out automated classifications of genes or proteins according to the criteria of the Gene Ontology Consortium at a level of depth defined by the user. Additionally, it performs clustering analysis of all sets based on functional categories or on differential expression levels. GARBAN also provides graphical representations of the biological pathways in which all the genes/proteins participate. AVAILABILITY: http://garban.tecnun.es.     

Electron and hole transfer from DNA base radicals to oxidized products of guanine in DNA

An investigation of electron and hole transfer to oxidized guanine bases in DNA is reported. Guanine in DNA was preferentially oxidized by Br(2)(*-) at 298 K to 8-oxo-7,8-dihydro-guanine (8-oxo-G) and higher oxidation products. HPLC-EC analysis of irradiated DNA shows that the formation of 8-oxo-G could not be increased above the ratio of one 8-oxo-G to 127 +/- 6 bp regardless of dose. 8-oxo-G can be produced only at low levels because it is further oxidized to other species. These oxidation products of guanine have been extensively investigated and identified by others. Our electron spin resonance studies suggest that at 77 K 8-oxo-G is a trap for radiation-produced holes, but certain further oxidation products of 8-oxo-G (G(ox)) are found to be efficient electron traps. Gamma irradiation of oxidized DNA samples in frozen (D(2)O) aqueous ices and glassy 7 M LiBr solutions resulted in radicals formed by electron attachment to the G(ox) sites that were monitored by electron spin resonance spectroscopy (ESR) at 77 K. These ESR spectra suggest that those oxidation products of 8-oxo-G containing alpha-diketo groups account for the electron traps (G(ox)) in oxidized DNA with oxaluric acid a likely major trap. Electron transfer from DNA anion radicals to G(ox) was followed by monitoring of their ESR signals with time at 77 K. Using typical values for the tunneling constant beta estimates of the relative amount of G(ox) to base pairs were obtained. Radicals formed by UV photolysis of oxidized DNA in 8 M NaClO(4) glassy aqueous solutions were also investigated. The 8-oxo-G cation accounts for less than 10% of all the radicals observed after either gamma irradiation of oxidized DNA in frozen (D(2)O) aqueous solution or UV photolysis of oxidized DNA in 8 M NaClO(4) glassy aqueous solutions. We estimate hole transfer distances of about 7 +/- 1 bp at 1 min from G(*+) to 8-oxo-G.     

Electron spin resonance study of DNA irradiated with an argon-ion beam: evidence for formation of sugar phosphate backbone radicals

In this study, the effects of high-LET radiation on DNA were investigated and compared with the effects of gamma radiation. Hydrated DNA samples at 77 K were irradiated with argon-ion beams ((36)Ar or (40)Ar beam at energies between 60 and 100 MeV/nucleon). The individual free radicals formed were identified and their yields were investigated by electron spin resonance spectroscopy. Argon-ion irradiation resulted in lower yields of base ion radicals and higher yields of neutral radicals than gamma irradiation. A hitherto unknown species was assigned to the radical formed by C-O bond rupture at the deoxyribose C3', resulting in a sugar carbon-centered radical. A previously characterized phosphorus-centered radical was also found. The formation of each of these species was accompanied by an immediate strand break. G values, k values, and analyses for the individual yields of neutral radicals and ion radical composition for argon-ion-irradiated hydrated DNA are reported and compared to those found previously for gamma-irradiated DNA. The lower G values and k values for ion radicals and the higher fraction of neutral radicals found for argon-ion-irradiated DNA are attributed to differences in track structure inherent in the two radiations.     

Marine hydrocarbonoclastic bacteria as whole‐cell biosensors for n‐alkanes

Whole‐cell biosensors offer potentially useful, cost‐effective systems for the in‐situ monitoring of seawater for hydrocarbons derived from accidental spills. The present work compares the performance of a biosensor system for the detection of alkanes in seawater, hosted in either Escherichia coli (commonly employed in whole‐cell biosensors but not optimized for alkane assimilation) or different marine bacteria specialized in assimilating alkanes. The sensor system was based on the Pseudomonas putida AlkS regulatory protein and the PalkB promoter fused to a gene encoding the green fluorescent protein. While the E. coli sensor provided the fastest response to pure alkanes (25‐fold induction after 2 h under the conditions used), a sensor based on Alcanivorax borkumensis was slower, requiring 3–4 h to reach similar induction values. However, the A. borkumensis sensor showed a fourfold lower detection threshold for octane (0.5 μM), and was also better at sensing the alkanes present in petrol. At petrol concentrations of 0.0125%, the A. borkumensis sensor rendered a sevenfold induction, while E. coli sensor showed no response. We discuss possible explanations to this behaviour in terms of the cellular adaptations to alkane uptake and the basal fluorescence produced by each bacterial strain, which was lowest for A. borkumensis.