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Find video protocols related to scientific articles indexed in Pubmed.
Electrochemical quantification of the antioxidant capacity of medicinal plants using biosensors.
Sensors (Basel)
PUBLISHED: 08-08-2014
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The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr) using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA), cross-linking using glutaraldehyde (GA), and cross-linking using GA and human serum albumin (HSA); the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric evaluations, the apparent Michaelis-Menten constant, Km', of each biosensor was evaluated while the respective charge transfer resistance, Rct, was assessed from impedance measurements. It was found that the SPE/Tyr/GA had the smallest Km' (57 ± 7) µM and Rct values. This electrode also displayed both the lowest detection and quantification limits for catechol quantification. Using the SPE/Tyr/GA, the Trolox Equivalent Antioxidant Capacity (TEAC) was determined from infusions prepared with "mirto" (Salvia microphylla), "hHierba dulce" (Lippia dulcis) and "salve real" (Lippia alba), medicinal plants commonly used in Mexico.
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Ascaris lumbricoides infection and parasite load are associated with asthma in children.
J Infect Dev Ctries
PUBLISHED: 07-16-2014
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Association between Ascaris lumbricoides infection and asthma is a controversial subject that has been studied by several authors based on the hygiene theory. This work contributes to better understanding this issue.
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Aromatic aldehydes at the active site of aldehyde oxidoreductase from Desulfovibrio gigas: reactivity and molecular details of the enzyme-substrate and enzyme-product interaction.
J. Biol. Inorg. Chem.
PUBLISHED: 07-08-2014
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Desulfovibrio gigas aldehyde oxidoreductase (DgAOR) is a mononuclear molybdenum-containing enzyme from the xanthine oxidase (XO) family, a group of enzymes capable of catalyzing the oxidative hydroxylation of aldehydes and heterocyclic compounds. The kinetic studies reported in this work showed that DgAOR catalyzes the oxidative hydroxylation of aromatic aldehydes, but not heterocyclic compounds. NMR spectroscopy studies using (13)C-labeled benzaldehyde confirmed that DgAOR catalyzes the conversion of aldehydes to the respective carboxylic acids. Steady-state kinetics in solution showed that high concentrations of the aromatic aldehydes produce substrate inhibition and in the case of 3-phenyl propionaldehyde a suicide substrate behavior. Hydroxyl-substituted aromatic aldehydes present none of these behaviors but the kinetic parameters are largely affected by the position of the OH group. High-resolution crystallographic structures obtained from single crystals of active-DgAOR soaked with benzaldehyde showed that the side chains of Phe425 and Tyr535 are important for the stabilization of the substrate in the active site. On the other hand, the X-ray data of DgAOR soaked with trans-cinnamaldehyde showed a cinnamic acid molecule in the substrate channel. The X-ray data of DgAOR soaked with 3-phenyl propionaldehyde showed clearly how high substrate concentrations inactivate the enzyme by binding covalently at the surface of the enzyme and blocking the substrate channel. The different reactivity of DgAOR versus aldehyde oxidase and XO towards aromatic aldehydes and N-heterocyclic compounds is explained on the basis of the present kinetic and structural data.
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Guest-host complex formed between ascorbic acid and ?-cyclodextrin immobilized on the surface of an electrode.
Molecules
PUBLISHED: 04-28-2014
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This work deals with the formation of supramolecular complexes between ascorbic acid (AA), the guest, and ?-cyclodextrin (?-CD), the host, that was first potentiodynamically immobilized on the surface of a carbon paste electrode (CPE) throughout the formation of a ?-CD-based conducting polymer (poly-?-CD). With the bare CPE and the ?-CD-modified CPE, an electrochemical study was performed to understand the effect of such surface modification on the electrochemical response of the AA. From this study it was shown that on the modified-CPE, the AA was surface-immobilized through formation of an inclusion complex with ?-CD, which provoked the adsorption of AA in such a way that this stage became the limiting step for the electrochemical oxidation of AA. Moreover, from the analysis of the experimental voltammetric plots recorded during AA oxidation on the CPE/poly-?-CD electrode surfaces, the Gibbs' standard free energy of the inclusion complex formed by the oxidation product of AA and ?-CD has been determined for the first time, ?G0inclus = -36.4 kJ/mol.
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TupA: a tungstate binding protein in the periplasm of Desulfovibrio alaskensis G20.
Int J Mol Sci
PUBLISHED: 03-31-2014
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The TupABC system is involved in the cellular uptake of tungsten and belongs to the ABC (ATP binding cassette)-type transporter systems. The TupA component is a periplasmic protein that binds tungstate anions, which are then transported through the membrane by the TupB component using ATP hydrolysis as the energy source (the reaction catalyzed by the ModC component). We report the heterologous expression, purification, determination of affinity binding constants and crystallization of the Desulfovibrio alaskensis G20 TupA. The tupA gene (locus tag Dde_0234) was cloned in the pET46 Enterokinase/Ligation-Independent Cloning (LIC) expression vector, and the construct was used to transform BL21 (DE3) cells. TupA expression and purification were optimized to a final yield of 10 mg of soluble pure protein per liter of culture medium. Native polyacrylamide gel electrophoresis was carried out showing that TupA binds both tungstate and molybdate ions and has no significant interaction with sulfate, phosphate or perchlorate. Quantitative analysis of metal binding by isothermal titration calorimetry was in agreement with these results, but in addition, shows that TupA has higher affinity to tungstate than molybdate. The protein crystallizes in the presence of 30% (w/v) polyethylene glycol 3350 using the hanging-drop vapor diffusion method. The crystals diffract X-rays beyond 1.4 Å resolution and belong to the P21 space group, with cell parameters a = 52.25 Å, b = 42.50 Å, c = 54.71 Å, ? = 95.43°. A molecular replacement solution was found, and the structure is currently under refinement.
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Prevalence of Entamoeba histolytica/Entamoeba dispar in the city of Campina Grande, in northeastern Brazil.
Rev. Inst. Med. Trop. Sao Paulo
PUBLISHED: 03-19-2014
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There is a clear need to perform epidemiological studies to find the true prevalence of Entamoeba histolytica around the world. The evaluation of this prevalence has been hindered by the existence of two different species which are morphologically identical, but genetically different, namely E. histolytica, which causes amebiasis, and E. dispar, which is non-pathogenic. In Brazil, the E. dispar has been detected in communities in the Southeastern (SE) and Northeastern (NE) regions with poor sanitation. However, individuals infected with E. histolytica have been identified in other regions. There is an absence of reports on the prevalence of these parasites in the state of Paraíba, which also has areas with poor sanitary conditions where a high prevalence of the E. histolytica/E. dispar complex has been detected in children from urban slums. The present study evaluated the prevalence of E. histolytica and E. dispar in 1,195 asymptomatic children between two and 10 years of age, living in a sprawling urban slum in Campina Grande, in the state of Paraíba, in Northeastern Brazil. These children were examined and their feces samples were analyzed microscopically. A total of 553 children tested positive for the E. histolytica/E. dispar complex, and 456 of the positive samples were tested with the E. histolytica II® ELISA kit. All 456 samples were negative for the presence of the adhesin E. histolytica specific antigen. The evidence suggests that in this community E. histolytica is absent and E. dispar is the dominant species.
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Epstein-Barr virus infection and clinical outcome in breast cancer patients correlate with immune cell TNF-?/IFN-? response.
BMC Cancer
PUBLISHED: 03-13-2014
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For nearly two decades now, various studies have reported detecting the Epstein-Barr virus (EBV) in breast cancer (BC) cases. Yet the results are unconvincing, and their interpretation has remained a matter of debate. We have now presented prospective data on the effect of EBV infection combined with survival in patients enrolled in a prospective study.
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Genetic identification of endangered North African ungulates using noninvasive sampling.
Mol Ecol Resour
PUBLISHED: 03-08-2014
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North African ungulates include several threatened and emblematic species, yet are poorly studied mainly due to their remoteness and elusiveness. Noninvasive sampling provides a useful approach to obtain ecological and genetic information essential to guide conservation actions. The very first and most important step in conservation planning is to accurately identify species, and molecular genetics has been proved to be a useful tool. Several molecular genetics protocols are available for species identification, even for samples with poor quality DNA, such as faeces, hairs or bones. Most of these protocols use mitochondrial DNA for barcoding despite this marker being especially prone to problems, including mtDNA introgression, nuclear insert copies, high intraspecific diversity or heteroplasmy. In this work, we developed a molecular method based on polymorphisms in small fragments of the mitochondrial cytochrome b (cytb, mtDNA) and the nuclear kappa casein genes (KCAS, nDNA) for identifying endangered North African ungulates. These fragments revealed polymorphisms, including species-specific variation, which allowed species identification of nine ungulate species that co-occur in North Africa. The method was validated across more than 400 samples, including different types of noninvasive samples collected in the field. The simplicity, high reliability and relative low cost of the described method make it a promising tool to improve ecological studies of the North African ungulates and consequently, the implementation of more efficient management and conservation plans for these endangered ungulates.
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Selecting low-cost carbon sources for carotenoid and lipid production by the pink yeast Rhodosporidium toruloides NCYC 921 using flow cytometry.
Bioresour. Technol.
PUBLISHED: 02-17-2014
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The present work studied low-cost carbon sources for carotenoid and lipid production using the yeast Rhodosporidum toruloides NCYC 921. Carob pulp syrup and sugarcane molasses at different concentrations were used as low-cost carbon sources in R. toruloides batch cultivations. Carob pulp syrup containing a total sugar concentration of 75 g L(-1) induced the highest total fatty acid productivity (1.90 g L(-1)h(-1)) and the highest carotenoid productivity (9.79 ?g L(-1)h(-1)). Flow cytometric analysis revealed that most of the yeast cells (>60%) grown on carob pulp syrup displayed intact polarised membranes, conversely to the cells grown on sugarcane molasses, wherein a large proportion (>45%) displayed permeabilised cytoplasmic membranes.
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Influence of the carbon source on Gordonia alkanivorans strain 1B resistance to 2-hydroxybiphenyl toxicity.
Appl. Biochem. Biotechnol.
PUBLISHED: 01-23-2014
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The viability of bacteria plays a critical role in the enhancement of fossil fuels biodesulfurization efficiency since cells are exposed to toxic compounds such as 2-hydroxybiphenyl (2-HBP), the end product of dibenzothiophene (DBT) biodesulfurization. The goal of this work was to study the influence of the carbon source on the resistance of Gordonia alkanivorans strain 1B to 2-HBP. The physiological response of this bacterium, pre-grown in glucose or fructose, to 2-HBP was evaluated using two approaches: a growth inhibition toxicity test and flow cytometry. The results obtained from the growth inhibition bioassays showed that the carbon source has an influence on the sensitivity of strain 1B growing cells to 2-HBP. The highest IC50 value was obtained for the assay using fructose as carbon source in both inoculum growth and test medium (IC50-48 h?=?0.464 mM). Relatively to the evaluation of 2-HBP effect on the physiological state of resting cells by flow cytometry, the results showed that concentrations of 2-HBP >1 mM generated significant loss of cell viability. The higher the 2-HBP concentration, the higher the toxicity effect on cells and the faster the loss of cell viability. In overall, the flow cytometry results highlighted that strain 1B resting cells grown in glucose-SO4 or glucose-DBT are physiologically less resistant to 2-HBP than resting cells grown in fructose-SO4 or fructose-DBT, respectively.
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Structural data on the periplasmic aldehyde oxidoreductase PaoABC from Escherichia coli: SAXS and preliminary X-ray crystallography analysis.
Int J Mol Sci
PUBLISHED: 01-21-2014
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The periplasmic aldehyde oxidoreductase PaoABC from Escherichia coli is a molybdenum enzyme involved in detoxification of aldehydes in the cell. It is an example of an ??? heterotrimeric enzyme of the xanthine oxidase family of enzymes which does not dimerize via its molybdenum cofactor binding domain. In order to structurally characterize PaoABC, X-ray crystallography and small angle X-ray scattering (SAXS) have been carried out. The protein crystallizes in the presence of 20% (w/v) polyethylene glycol 3350 using the hanging-drop vapour diffusion method. Although crystals were initially twinned, several experiments were done to overcome twinning and lowering the crystallization temperature (293 K to 277 K) was the solution to the problem. The non-twinned crystals used to solve the structure diffract X-rays to beyond 1.80 Å and belong to the C2 space group, with cell parameters a = 109.42 Å, b = 78.08 Å, c = 151.77 Å, ? = 99.77°, and one molecule in the asymmetric unit. A molecular replacement solution was found for each subunit separately, using several proteins as search models. SAXS data of PaoABC were also collected showing that, in solution, the protein is also an ??? heterotrimer.
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Long-term ventilation in children: Ten years later.
Rev Port Pneumol
PUBLISHED: 01-16-2014
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Home mechanical ventilation (HMV) represents a treatment option for patients with chronic respiratory failure and has changed prognosis and survival of many disorders in children. The aim of this study was to characterize a group of children on long-term mechanical ventilation (LTMV) for a period longer than 10 years.
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Acute effects of whole-body vibration on the motor function of patients with stroke: a randomized clinical trial.
Am J Phys Med Rehabil
PUBLISHED: 01-09-2014
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The aim of this study was to investigate the acute effects of whole-body vibration on the motor function of patients with stroke.
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Do newborn vocalizations affect the behavioral and hormonal responses of nonreproductive male common marmosets (Callithrix jacchus)?
Primates
PUBLISHED: 01-07-2014
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Parental care in mammals is influenced by sensory stimuli from infants, such as sight and sound, and by changes in the hormone levels of caretakers. To determine the responsiveness of common marmoset (Callithrix jacchus) adult males with and without previous experience in caretaking to newborn sensory cues, we exposed twelve males to infant vocalization recordings and assessed their hormonal and behavioral responses. Males were placed in the testing cage for 10 min under two conditions: (a) control condition (exposure to adult conspecific vocalization recordings), and (b) experimental condition (exposure to infant vocalization recordings). We recorded the frequency of approach towards the sound source, the time spent near it and locomotion frequency of males in the cage under both conditions. Blood samples were collected after each test for cortisol, measured by the enzyme immunoassay method. Infant vocalization affects the behavioral and hormonal responses of non-reproductive male common marmosets. All males approached and spent more time near the sound source and showed an increase in locomotion during infant vocalization exposure compared to the control condition. Successive exposure to infant vocalization increased the responsiveness in inexperienced males. Cortisol levels were significantly higher following infant vocalization exposure compared to the control condition. These findings support the assumption that sound stimuli from the newborn are critical in initiating and maintaining caretaker responsiveness and that cortisol seems to be important for alertness to sensory stimuli, modulating their motivation to interact with infants.
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Splitting or lumping? A conservation dilemma exemplified by the critically endangered dama gazelle (Nanger dama).
PLoS ONE
PUBLISHED: 01-01-2014
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Managers of threatened species often face the dilemma of whether to keep populations separate to conserve local adaptations and minimize the risk of outbreeding, or whether to manage populations jointly to reduce loss of genetic diversity and minimise inbreeding. In this study we examine genetic relatedness and diversity in three of the five last remaining wild populations of dama gazelle and a number of captive populations, using mtDNA control region and cytochrome b data. Despite the sampled populations belonging to the three putative subspecies, which are delineated according to phenotypes and geographical location, we find limited evidence for phylogeographical structure within the data and no genetic support for the putative subspecies. In the light of these data we discuss the relevance of inbreeding depression, outbreeding depression, adaptive variation, genetic drift, and phenotypic variation to the conservation of the dama gazelle and make some recommendations for its future conservation management. The genetic data suggest that the best conservation approach is to view the dama gazelle as a single species without subspecific divisions.
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Biochemical, stabilization and crystallization studies on a molecular chaperone (PaoD) involved in the maturation of molybdoenzymes.
PLoS ONE
PUBLISHED: 01-01-2014
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Molybdenum and tungsten enzymes require specific chaperones for folding and cofactor insertion. PaoD is the chaperone of the periplasmic aldehyde oxidoreductase PaoABC. It is the last gene in the paoABCD operon in Escherichia coli and its presence is crucial for obtaining mature enzyme. PaoD is an unstable, 35 kDa, protein. Our biochemical studies showed that it is a dimer in solution with a tendency to form large aggregates, especially after freezing/thawing cycles. In order to improve stability, PaoD was thawed in the presence of two ionic liquids [C4mim]Cl and [C2OHmim]PF6 and no protein precipitation was observed. This allowed protein concentration and crystallization using polyethylene glycol or ammonium sulfate as precipitating agents. Saturation transfer difference - nuclear magnetic resonance (STD-NMR) experiments have also been performed in order to investigate the effect of the ionic liquids in the stabilization process, showing a clear interaction between the acidic ring protons of the cation and, most likely, negatively charged residues at the protein surface. DLS assays also show a reduction of the overall size of the protein aggregates in presence of ionic liquids. Furthermore, cofactor binding studies on PaoD showed that the protein is able to discriminate between molybdenum and tungsten bound to the molybdenum cofactor, since only a Mo-MPT form of the cofactor remained bound to PaoD.
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Heart failure: expressions of personal knowledge about the disease.
Rev Esc Enferm USP
PUBLISHED: 12-07-2013
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This qualitative study characterized individuals with heart failure (HF) according to their sociodemographic, health, and treatment profiles and analyzed their knowledge on the disease and its treatment. A total of 42 volunteers with HF were interviewed at a cardiology hospital in São Paulo using a semi-structured questionnaire; the data were subjected to content analysis. The sample comprised mostly males and individuals older than 45 years old; the sample was classified as functional class II with associated comorbidities and was subjected to pharmacological treatment. The type of knowledge exhibited by the sample was illustrative, diagnostic, and explanatory, and many different meanings were attributed to the disease. Most volunteers did not know the names, doses, or frequencies of use of their medications. Non-pharmacological treatment was identified as related to the information provided by the healthcare professionals about nutrition and salt and water intake. The results pave the road for systematic educational interventions that can improve the coping with and management of this disease.
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Characterization of a versatile organometallic pro-drug (CORM) for experimental CO based therapeutics.
Dalton Trans
PUBLISHED: 10-23-2013
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The complex fac-[Mo(CO)(3)(histidinate)]Na has been reported to be an effective CO-Releasing Molecule in vivo, eliciting therapeutic effects in several animal models of disease. The CO releasing profile of this complex in different settings both in vitro and in vivo reveals that the compound can readily liberate all of its three CO equivalents under biological conditions. The compound has low toxicity and cytotoxicity and is not hemolytic. CO release is accompanied by a decrease in arterial blood pressure following administration in vivo. We studied its behavior in solution and upon the interaction with proteins. Reactive oxygen species (ROS) generation upon exposure to air and polyoxomolybdate formation in soaks with lysozyme crystals were observed as processes ensuing from the decomposition of the complex and the release of CO.
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Deprotonation mechanism and acidity constants in aqueous solution of flavonols: a combined experimental and theoretical study.
J Phys Chem B
PUBLISHED: 10-07-2013
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Four flavonols, namely quercetin, morin, kaempferol, and myricetin, were studied using spectrophotometry (UV-vis) in aqueous solution. The study was performed varying the pH to analyze the stability of these compounds, and to estimate their acidity constants. In addition, the deprotonation mechanisms were studied using computational chemistry within the density functional theory framework. The calculations were performed in aqueous solution using the SMD continuum model, and the results are reported as deprotonation energies. Our results show that both quercetin and myricetin are highly unstable at basic pH. Kaempferol, on the other hand, is much more stable, and morin is the only one among the studied compounds that was not affected by pH. In spite of this inconvenience, their acidity constants were estimated through analysis of their decomposition kinetics, correcting the spectra accordingly, and obtaining a correlation of values between the experimentally observed pKa and the calculated ?G of successive deprotonations.
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A collection of popcorn as a reservoir of genes for the generation of lineages.
Mol. Biotechnol.
PUBLISHED: 09-13-2013
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In the present study, we analyze the genetic structure and diversity among accessions of popcorn obtained from the CIMMYT International Maize and Wheat Improvement Center that represent the diversity available for current use by breeding programs. The main objectives were to identify SSR loci that were the best indicators of genetic diversity, to measure the genetic diversity within popcorn genotypes, and to analyze the genetic structure of the promising populations destined for use in breeding programs. The mean gene diversity of all SSR loci was 0.6352. An extremely high population differentiation level was detected (F(st) = 0.3152) with F(st) for each locus ranging from 0.1125 (Umc1229) to 0.4870 (Umc1755). Analyzing the genetic structure of eight popcorn accessions was especially important for identifying both SSR loci with high levels of heterozygosity and genotypes showing high heterozygosity (BOYA462 and ARZM13 050). This analysis should be the medium and long-term selection goal for the generation of inbred lines and the future production of new cultivars. Plant accessions ARZM05 083, ARZM13 050, and URUG298 may also be useful varieties that exhibit important agronomic characteristics that can be used through crosses to broaden the genetic basis of popcorn.
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Heterogeneity Within Multiple Perpetrator Rapes: A National Comparison of Lone, Duo, and 3+ Perpetrator Rapes.
Sex Abuse
PUBLISHED: 09-03-2013
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The effect of number of perpetrators involved in multiple perpetrator rapes on offense characteristics is underresearched despite beliefs that duos/dyads differ in their interactions and dynamics to groups of 3+ members. We analyzed a national sample of 336 allegations of completed and attempted rape of female victims from the United Kingdom. Rapes committed by multiple (duos and groups of 3+ perpetrators) and lone offenders were compared on offense characteristics (incorporating the approach, maintenance, and closure phases of each rape) and victim and offender sociodemographic characteristics. Significant differences between rapes committed by lone, duo, and 3+ group offenders were found for the age and ethnicity of the offenders; the type of approach used; the locations of the initial contact, assault, and release of the victims; the use of a vehicle; the precautions utilized; the verbal themes present; and the sex acts performed. These results have implications for educational prevention programs and interventions with offenders.
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Cardiac dysfunction in mitochondrial disease. Clinical and molecular features.
Circ. J.
PUBLISHED: 08-20-2013
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Mitochondrial disorders (MD) are multisystem diseases that arise as a result of dysfunction of the oxidative phosphorylation system. The predominance of neuromuscular manifestations in MD could mask the presence of other clinical phenotypes such as cardiac dysfunction. Reported here is a retrospective study, the main objective of which was to characterize the clinical and molecular features of a cohort of patients with cardiomyopathy and MD.
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Integrated microbial processes for biofuels and high value-added products: the way to improve the cost effectiveness of biofuel production.
Appl. Microbiol. Biotechnol.
PUBLISHED: 08-02-2013
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The production of microbial biofuels is currently under investigation, as they are alternative sources to fossil fuels, which are diminishing and their use has a negative impact on the environment. However, so far, biofuels derived from microbes are not economically competitive. One way to overcome this bottleneck is the use of microorganisms to transform substrates into biofuels and high value-added products, and simultaneously taking advantage of the various microbial biomass components to produce other products of interest, as an integrated process. In this way, it is possible to maximize the economic value of the whole process, with the desired reduction of the waste streams produced. It is expected that this integrated system makes the biofuel production economically sustainable and competitive in the near future. This review describes the investigation on integrated microbial processes (based on bacteria, yeast, and microalgal cultivations) that have been experimentally developed, highlighting the importance of this approach as a way to optimize microbial biofuel production process.
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Unravelling biodiversity, evolution and threats to conservation in the Sahara-Sahel.
Biol Rev Camb Philos Soc
PUBLISHED: 05-28-2013
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Deserts and arid regions are generally perceived as bare and rather homogeneous areas of low diversity. The Sahara is the largest warm desert in the world and together with the arid Sahel displays high topographical and climatic heterogeneity, and has experienced recent and strong climatic oscillations that have greatly shifted biodiversity distribution and community composition. The large size, remoteness and long-term political instability of the Sahara-Sahel, have limited knowledge on its biodiversity. However, over the last decade, there have been an increasing number of published scientific studies based on modern geomatic and molecular tools, and broad sampling of taxa of these regions. This review tracks trends in knowledge about biodiversity patterns, processes and threats across the Sahara-Sahel, and anticipates needs for biodiversity research and conservation. Recent studies are changing completely the perception of regional biodiversity patterns. Instead of relatively low species diversity with distribution covering most of the region, studies now suggest a high rate of endemism and larger number of species, with much narrower and fragmented ranges, frequently limited to micro-hotspots of biodiversity. Molecular-based studies are also unravelling cryptic diversity associated with mountains, which together with recent distribution atlases, allows identifying integrative biogeographic patterns in biodiversity distribution. Mapping of multivariate environmental variation (at 1?km?×?1?km resolution) of the region illustrates main biogeographical features of the Sahara-Sahel and supports recently hypothesised dispersal corridors and refugia. Micro-scale water-features present mostly in mountains have been associated with local biodiversity hotspots. However, the distribution of available data on vertebrates highlights current knowledge gaps that still apply to a large proportion of the Sahara-Sahel. Current research is providing insights into key evolutionary and ecological processes, including causes and timing of radiation and divergence for multiple taxa, and associating the onset of the Sahara with diversification processes for low-mobility vertebrates. Examples of phylogeographic patterns are showing the importance of allopatric speciation in the Sahara-Sahel, and this review presents a synthetic overview of the most commonly hypothesised diversification mechanisms. Studies are also stressing that biodiversity is threatened by increasing human activities in the region, including overhunting and natural resources prospection, and in the future by predicted global warming. A representation of areas of conflict, landmines, and natural resources extraction illustrates how human activities and regional insecurity are hampering biodiversity research and conservation. Although there are still numerous knowledge gaps for the optimised conservation of biodiversity in the region, a set of research priorities is provided to identify the framework data needed to support regional conservation planning.
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The influence of age, smoking, antiretroviral therapy, and esophagitis on the local immunity of the esophagus in patients with AIDS.
J Int Assoc Provid AIDS Care
PUBLISHED: 05-15-2013
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Studies have shown immunological and morphological alterations in the esophagus during the course of AIDS. Esophageal postmortem samples of 22 men with AIDS autopsied in a teaching hospital between 1982 and 2009 were collected. We carried out revision of the autopsy reports and medical records, morphometric analysis (Image J and KS-300 Kontron-Zeiss), and immunohistochemical (anti-S100, anti-IgA, anti-IgG, and anti-IgM) analysis of the esophagus. In accordance with most of the parameters evaluated, age and the smoking habit harmed the esophageal local immunity, whereas the use of antiretroviral therapy improved the immune characteristics of this organ. Patients with esophagitis also presented immunological fragility of the esophagus. This leads to the conclusion that alterations in the esophageal epithelium of patients with AIDS are not only caused by direct action of HIV but also the clinical and behavioral characteristics of the patient.
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Selenium compounds induced ROS-dependent apoptosis in myelodysplasia cells.
Biol Trace Elem Res
PUBLISHED: 05-14-2013
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Several authors have demonstrated the chemoprotective and anti-carcinogenic role of selenium. However, the therapeutic potential of selenium in myelodysplastic syndrome (MDS) as single agent and as co-adjuvant of the current therapies has not been previously studied. Sodium selenite and selenomethionine, alone and in combination with cytarabine, induce a decrease in cell viability in a time-, dose- and administration-dependent manner inducing cell death by apoptosis in F36P cells (MDS cell line). These compounds increased superoxide production and induced mitochondrial membrane depolarization. The increase in BAX/BCL-2 ratio and in the activated caspase 3 expression levels, the decrease in mitochondria membrane potential, as well as the increase in superoxide production, supports the mitochondria contribution on selenium-induced apoptosis. These findings suggest that selenium may offer a new therapeutic approach in myelodysplastic syndrome in monotherapy and/or as co-adjuvant therapy to conventional anti-carcinogenic.
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A new mutation in the gene encoding mitochondrial seryl-tRNA synthetase as a cause of HUPRA syndrome.
BMC Nephrol
PUBLISHED: 05-07-2013
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HUPRA syndrome is a rare mitochondrial disease characterized by hyperuricemia, pulmonary hypertension, renal failure in infancy and alkalosis. This syndrome was previously described in three patients with a homozygous mutation c.1169A > G (p.D390G) in SARS2, encoding the mitochondrial seryl-tRNA synthetase.
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Exome sequencing identifies a new mutation in SERAC1 in a patient with 3-methylglutaconic aciduria.
Mol. Genet. Metab.
PUBLISHED: 04-29-2013
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3-Methylglutaconic aciduria (3-MGA-uria) is a heterogeneous group of syndromes characterized by an increased excretion of 3-methylglutaconic and 3-methylglutaric acids. Five types of 3-MGA-uria (I to V) with different clinical presentations have been described. Causative mutations in TAZ, OPA3, DNAJC19, ATP12, ATP5E, and TMEM70 have been identified. After excluding the known genetic causes of 3-MGA-uria we used exome sequencing to investigate a patient with Leigh syndrome and 3-MGA-uria. We identified a homozygous variant in SERAC1 (c.202C>T; p.Arg68*), that generates a premature stop codon at position 68 of SERAC1 protein. Western blot analysis in patients fibroblasts showed a complete absence of SERAC1 that was consistent with the prediction of a truncated protein and supports the pathogenic role of the mutation. During the course of this project a parallel study identified mutations in SERAC1 as the genetic cause of the disease in 15 patients with MEGDEL syndrome, which was compatible with the clinical and biochemical phenotypes of the patient described here. In addition, our patient developed microcephaly and optic atrophy, two features not previously reported in MEGDEL syndrome. We highlight the usefulness of exome sequencing to reveal the genetic bases of human rare diseases even if only one affected individual is available.
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Assessment of ?-carotene content, cell physiology and morphology of the yellow yeast Rhodotorula glutinis mutant 400A15 using flow cytometry.
J. Ind. Microbiol. Biotechnol.
PUBLISHED: 04-21-2013
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Flow cytometry was used to assess ?-carotene content, cell membrane permeability, cell size and granularity in Rhodotorula glutinis mutant 400A15 grown under different oxygen transfer coefficients (k L a) and carbon to nitrogen ratios (C/N). A Doehlert distribution was used in order to select the best conditions that induced the highest carotenoids production. The highest ?-carotene content (0.79 mg g(-1) DCW) at the lowest k L a and C/N (5 × 10(-3) s(-1) and 11.3 respectively). Under these conditions, the biomass concentration attained 18.60 g L(-1). The highest ratio of cells with permeabilised membranes (2.6 %), and the highest cell size and granularity were also obtained under these conditions. It was observed that C/N showed a stronger influence than the k L a on the measured cell parameters.
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Whole-exome sequencing identifies a variant of the mitochondrial MT-ND1 gene associated with epileptic encephalopathy: west syndrome evolving to Lennox-Gastaut syndrome.
Hum. Mutat.
PUBLISHED: 03-21-2013
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We describe a West syndrome (WS) patient with unidentified etiology that evolved to Lennox-Gastaut syndrome. The mitochondrial respiratory chain of the patient showed a simple complex I deficiency in fibroblasts. Whole-exome sequencing (WES) uncovered two heterozygous mutations in NDUFV2 gene that were reassigned to a pseudogene. With the WES data, it was possible to obtain whole mitochondrial DNA sequencing and to identify a heteroplasmic variant in the MT-ND1 (MTND1) gene (m.3946G>A, p.E214K). The expression of the gene in patient fibroblasts was not affected but the protein level was significantly reduced, suggesting that protein stability was affected by this mutation. The lower protein level also affected assembly of complex I and supercomplexes (I/III2 /IV and I/III2 ), leading to complex I deficiency. While ATP levels at steady state under stress conditions were not affected, the amount of ROS produced by complex I was significantly increased.
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Oxidative stress mediates apoptotic effects of ascorbate and dehydroascorbate in human Myelodysplasia cells in vitro.
Toxicol In Vitro
PUBLISHED: 03-16-2013
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The Myelodysplastic Syndromes are stem cell heterogeneous disorders characterized by peripheral cytopenias and hypercellular bone marrow, which can evolute to acute leukaemia. Vitamin C can act as an antioxidant, ascorbic acid (AA) donates two electrons and becomes oxidized to dehydroascorbic acid (DHA). Under physiological conditions, vitamin C predominantly exists in its reduced (AA) form but also exists in trace quantities in the oxidized form (DHA). This study evaluates the therapeutic potential of vitamin C in Myelodysplastic Syndromes (MDSs). F36P cells (MDS cell line) were treated with ascorbate and dehydroascorbate alone and in combination with cytarabine. Cell proliferation and viability were assessed by trypan blue assay and cell death was evaluated by optical microscopy and flow cytometry. The role of reactive oxygen species, mitochondrial membrane potential, BAX, BCL-2 and cytochrome C were also assessed. Vitamin C decreases cell proliferation and viability in a concentration, time and administration dependent-manner inducing cell death by apoptosis, which was shown to be associated to an increased in superoxide production, mitochondrial membrane depolarization. These compounds modulate BCL-2, BAX and cytochrome C release. These results suggest that vitamin C induces cell death trough apoptosis in F36P cells and may be a new therapeutic approach in Myelodysplasia.
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A new walking aid with axillary support for children with cerebral palsy: electromyographic evaluation.
Disabil Rehabil Assist Technol
PUBLISHED: 03-12-2013
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To present a new walking aid with axillary support (WAAS) for children with cerebral palsy (CP) and to investigate its impact on the lower limb muscles activation in the gait of children with CP.
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Phylogeography of the neotropical Anopheles triannulatus complex (Diptera: Culicidae) supports deep structure and complex patterns.
Parasit Vectors
PUBLISHED: 02-13-2013
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The molecular phylogenetic relationships and population structure of the species of the Anopheles triannulatus complex: Anopheles triannulatus s.s., Anopheles halophylus and the putative species Anopheles triannulatus C were investigated.
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Self-Reported Physical and Emotional Abuse Among Youth Offenders and Their Association With Internalizing and Externalizing Psychopathology: A Preliminary Study.
Int J Offender Ther Comp Criminol
PUBLISHED: 01-31-2013
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The aim of this exploratory study was twofold. First, the severity of physical and emotional abuse perpetrated by parents and its association with internalizing and externalizing problems were explored in a sample of 104 male and female youth offenders. Second, we tested the moderate effect of callous-unemotional traits on the relation between physical and emotional victimization and internalizing and externalizing problems in boys. The analyses revealed that a high percentage of youth offenders reported having been physically abused. More severe physical abuse was not related to higher levels of internalizing or externalizing problems. Young offenders emotional abuse levels were low; however, this type of abuse was positively associated with externalizing problems among boys, regardless of the level of callous-unemotional traits. Thus, we suggest that youth offenders must be assessed using measures of physical and emotional abuse, and their case management should integrate specific programs to focus on the family environment to which the adolescents will most likely return after their sentence.
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Use of multi-parameter flow cytometry as tool to monitor the impact of formic acid on Saccharomyces carlsbergensis batch ethanol fermentations.
Appl. Biochem. Biotechnol.
PUBLISHED: 01-29-2013
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The use of lignocellulosic materials as substrate for bioethanol production is considered a cost-effective approach to make the biofuel production process economically sustainable. However, lignocellulosic hydrolysis releases toxic compounds such as weak acids which inhibit microorganism growth and ethanol production. In order to understand the physiological response of Saccharomyces carlsbergensis when fermenting glucose in the presence of formic acid (HF), the yeast growth was monitored by multi-parameter flow cytometry. Cytoplasmic membrane potential decreased as the HF concentration increased and as the yeast culture reached the stationary phase. However, the proportion of cells with permeabilized membrane did not increase with the HF concentration increase. The accumulation of reactive oxygen species was also monitored. Control and fermentations at low HF concentrations (<1 g/L) resulted in a high proportion of highly oxidized cells at the stationary phase. The multi-parameter flow cytometry approach proved to be a useful tool to monitor the physiological stress response of S. carlsbergensis growth and ethanol production in the presence of HF, an inhibitor present in lignocellulosic hydrolysates. The information here obtained at near real time can be used to enhance second-generation bioethanol production process efficiency.
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Interaction of vanadium(IV) with human serum apo-transferrin.
J. Inorg. Biochem.
PUBLISHED: 01-17-2013
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The interaction of V(IV)O-salts as well as of a few V(IV)O(carrier)n complexes with human serum transferrin (hTF) is studied focusing on the determination of the nature and stoichiometry of the binding of V(IV)O(2+) to hTF, as well as whether the conformation of hTF upon binding to V(IV)O(2+) or to its complexes is changed. Circular dichroism (CD) spectra measured for solutions containing V(IV)O(2+) and apo-hTF, and V(IV)O-maltol and apo-hTF, clearly indicate that hTF-V(IV)O-maltol ternary species form with a V(IV)O:maltol stoichiometry of 1:1. For V(IV)O salts and several V(IV)O(carrier)n complexes (carrier ligand=maltolato, dhp, picolinato and dipicolinato) (Hdhp=1,2-dimethyl-3-hydroxy-4-pyridinone) the maximum number of V(IV)O(2+) bound per mole of hTF is determined to be ~2 or lower in all cases. The binding of V(IV)O to apo-hTF most certainly involves several amino acid residues of the Fe-binding site, and as concluded by urea gel electrophoresis experiments, the formation of (V(IV)O)2hTF species may occur with the closing of the hTF conformation as is the case in (Fe(III))2hTF, which is an essential feature for the transferrin receptor recognition.
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Specific detection of Pneumocystis jirovecii in clinical samples by flow cytometry.
Methods Mol. Biol.
PUBLISHED: 01-09-2013
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Pneumocystis jirovecii is an opportunistic pathogen responsible for severe pneumonia in immunocompromised patients. Flow cytometry (FC) is a method widely used in different areas of clinical diagnosis like hematology and immunology. Recently it has started to be used in microbiology with a great potential for diagnosis of emergent microorganisms in clinical samples, especially when present in low numbers. The detection of Pneumocystis jirovecii in respiratory samples can be performed by FC, using specific monoclonal antibodies. Considering clinical diagnosis as a reference method, we previously showed FC to be 100% sensitive and specific when compared to immunofluorescence. Being an automated method, it is faster and less subject to human error than microscopic evaluation.
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Almitrine Fails to Improve Oxygenation During One-Lung Ventilation with Sevoflurane Anesthesia.
J. Cardiothorac. Vasc. Anesth.
PUBLISHED: 01-07-2013
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Almitrine enhances hypoxic pulmonary vasoconstriction (HPV) and can improve hypoxemia related to one-lung ventilation (OLV). Studies using almitrine have been conducted without inhaled anesthetics because they could inhibit HPV, counteracting the effect of almitrine. This hypothesis, however, has not been confirmed. This studys aim was to evaluate whether almitrine could improve oxygenation when administered during OLV with sevoflurane anesthesia.
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Microbial spoilage of portuguese chouriço along shelf life period.
Braz. J. Microbiol.
PUBLISHED: 01-01-2013
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Microbial flora of portuguese chouriço (Alentejano (A) and Ribatejano (R)) with abnormal sensorial characteristics along shelf life was studied. Mesophilic anaerobic bacteria, enterococci, mesophilic sporeformers, coliforms, coagulase-positive staphylococci, sulphite reducing clostridia, Clostridium perfringens, moulds and yeasts were the most representative in both types of chouriço.
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A quantitative study of the cell-type specific modulation of c-Rel by hydrogen peroxide and TNF-?.
Redox Biol
PUBLISHED: 01-01-2013
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Hydrogen peroxide (H2O2) at moderate steady-state concentrations synergizes with TNF-?, leading to increased nuclear levels of NF-?B p65 subunit and to a cell-type specific up-regulation of a limited number of NF-?B-dependent genes. Here, we address how H2O2 achieves this molecular specificity. HeLa and MCF-7 cells were exposed to steady-state H2O2 and/or TNF-? and levels of c-Rel, p65, I?B-?, I?B-? and I?B-? were determined. For an extracellular concentration of 25 µM H2O2, the intracellular H2O2 concentration is 3.7 µM and 12.5 µM for respectively HeLa and MCF-7 cells. The higher cytosolic H2O2 concentration present in MCF-7 cells may be a contributing factor for the higher activation of NF-?B caused by H2O2 in this cell line, when compared to HeLa cells. In both cells lines, H2O2 precludes the recovery of TNF-?-dependent I?B-? degradation, which may explain the observed synergism between H2O2 and TNF-? concerning p65 nuclear translocation. In MCF-7 cells, H2O2, in the presence of TNF-?, tripled the induction of c-Rel triggered either by TNF-? or H2O2. Conversely, in HeLa cells, H2O2 had a small antagonistic effect on TNF-?-induced c-Rel nuclear levels, concomitantly with a 50 % induction of I?B-?, the preferential inhibitor protein of c-Rel dimers. The 6-fold higher c-Rel/I?B-? ratio found in MCF-7 cells when compared with HeLa cells, may be a contributing factor for the cell-type dependent modulation of c-Rel by H2O2. Our results suggest that H2O2 might have an important cell-type specific role in the regulation of c-Rel-dependent processes, e.g. cancer or wound healing.
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Leadership in multiple perpetrator stranger rape.
J Interpers Violence
PUBLISHED: 12-26-2011
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Sexual offences by multiple perpetrators are more violent and involve more severe forms of sexual violation than those perpetrated by a lone offender. Often a clear leader exists within these groups. Questions have been raised as to the relative risk of reoffending and the potentially differing criminogenic needs of leaders and followers. However, a recent study comparing leaders and followers in juvenile multiple perpetrator rapes (tHart-Kerkhoffs et al., 2011) failed to find some of the expected differences. It was proposed that this might be due, in part, to the way leaders and followers were classified in the study. Before work can progress in this area, it is important to devise reliable and valid means of identifying leaders and followers in multiple perpetrator rape. This article reports on a study which investigated the utility of two different methods of identifying leadership. The Scale of Influence (Porter & Alison, 2001) was applied to a sample of 256 offenders responsible for 95 multiple perpetrator rapes from the United Kingdom. Following this, the relative number of directives uttered by offenders was used to designate leadership. In 66% of the offences sampled, a leader was designated using the number of directives uttered compared with 80% when using the Scale of Influence. When combining both measures to form a composite measure of leadership, this percentage increased to 89%. Classifications of offenders as leaders, followers, and neither, according to the Scale of Influence, the count of directives, and the composite measure, were compared with classifications made by a practitioner to assess their concordance. The composite measure showed the greatest agreement with practitioner opinion. These findings suggest that the Scale of Influence could be developed to take account of other ways that leadership is displayed during multiple perpetrator rapes.
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Acute striatal necrosis in hemiplegic migraine with de novo CACNA1A mutation.
Headache
PUBLISHED: 11-16-2011
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We report the case of a 9-year-old girl with early-onset developmental delay, chronic ataxia and prolonged hemiplegic migraine episodes bringing about progressive deterioration. Two days into one episode, diffusion-weighted magnetic resonance imaging disclosed unilateral striatal abnormal signal consistent with cytotoxic edema, which evolved into atrophy on follow-up scans. Mutational screen of CACNA1A gene identified a de novo p.Tyr1387Cys mutation.
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[Clinical outcomes of 2 pediatric patients with Gauchers disease in enzyme replacement therapy for 9 years].
Med Clin (Barc)
PUBLISHED: 10-10-2011
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We report two cases of type 1 Gauchers disease in childhood and their outcomes after 9 years of enzyme replacement therapy. The first case concerns a 6-year-old boy who was diagnosed with Gauchers disease after developing petechial exanthema, thrombocytopenia, anemia and hepatosplenomegaly, coinciding with chickenpox. The second case involves a 9-year-old girl who was referred to our unit. She had hepatosplenomegaly since 4-month-old and subsequently developed thrombocytopenia. Both patients have the N370S/L444P mutation. Enzyme replacement therapy was started with 60 U/kg imiglucerase every 2 weeks at the age of 6 and 9 years, respectively. In both patients, the therapeutic goals were achieved and maintained throughout treatment with a dose of 30 U/kg.
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Human cutaneous leishmaniasis: interferon-dependent expression of double-stranded RNA-dependent protein kinase (PKR) via TLR2.
FASEB J.
PUBLISHED: 08-16-2011
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We investigated the type I interferon (IFN-1)/PKR axis in the outcome of the Leishmania (Leishmania) amazonensis infection, along with the underlying mechanisms that trigger and sustain this signaling pathway. Reporter assays of cell extracts from RAW-264.7 macrophages infected with L. (L.) amazonensis or HEK-293T cells cotransfected with TLR2 and PKR promoter constructions were employed. Primary macrophages of TLR2-knockout (KO) or IFNR-KO mice were infected, and the levels of PKR, IFN-1, and superoxide dismutase 1 (SOD1) transcript levels were investigated and compared. Immunohistochemical analysis of human biopsy lesions was evaluated for IFN-1 and PKR-positive cells. Leishmania infection increased the expression of PKR and IFN-? on induction of PKR-promoter activity. The observed effects required the engagement of TLR2. TLR2-KO macrophages expressed low IFN-? and PKR levels postinfection with a reduced parasite load. We also revealed the requirement of PKR signaling for Leishmania-induced IFN-1 expression, responsible for sustaining PKR expression and enhancing infection. Moreover, during infection, SOD1 transcripts increased and were also enhanced when IFN-1 was added to the cultures. Remarkably, SOD1 expression was abrogated in infected, dominant-negative PKR-expressing cells. Finally, lesions of patients with anergic diffuse cutaneous leishmaniasis exhibited higher levels of PKR/IFN-1-expressing cells compared to those with single cutaneous leishmaniasis. In summary, we demonstrated the mechanisms and relevance of the IFN-1/PKR axis in the Leishmania infection.
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Monitoring Rhodosporidium toruloides NCYC 921 batch fermentations growing under carbon and nitrogen limitation by flow cytometry.
World J. Microbiol. Biotechnol.
PUBLISHED: 06-20-2011
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The yeast Rhodosporidium toruloides NCYC 921 was grown on carbon or nitrogen limited batch cultures. The fermentations were monitored using traditional techniques and multi-parameter flow cytometry. The lipid content was assessed by flow cytometry in association with the fluorocrome Nile Red which emits yellow gold fluorescence when dissolved in neutral lipids and red fluorescence when dissolved in polar lipids. In this way, it was possible to at-line monitor the yeast lipid composition in terms of polarity classes throughout the batch growths. It was found that the neutral lipids decreased during the carbon-limited stationary phase, and increased during the nitrogen-limited batch growth. The maximum lipid content was obtained for the nitrogen-limited yeast culture (24% w/w lipids). The yeast cells with permeabilised membranes profile remained almost unchanged during the time course of both fermentations. The scatter light measurements (forward and side scatter signals) provided information on the yeast growth phase. The multi-parameter flow cytometric approach here reported represents a better control system based on measurements made at the single cell level for optimization of the yeast lipid production bioprocess performance.
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Knocking out of CD38 accelerates development of a lupus-like disease in lpr mice.
Rheumatology (Oxford)
PUBLISHED: 05-17-2011
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CD38 participates in lymphocyte ontogeny and function and may be involved in autoimmunity. Absence of CD38 accelerates development of non-obese diabetic (NOD) mice diabetes and anti-CD38 antibodies are good markers of human disease. Little is known regarding systemic autoimmunity. Active SLE patients have higher numbers of CD38(+) T and B cells. CD38 is a candidate gene for the murine Lmb2 lupus locus. We aimed to investigate whether CD38 was involved in lupus development.
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Molecular divergence in the timeless and cpr genes among three sympatric cryptic species of the Anopheles triannulatus complex.
Mem. Inst. Oswaldo Cruz
PUBLISHED: 04-29-2011
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Anopheles triannulatus s.l. is a malaria vector with a wide geographic distribution, ranging from Argentina-Nicaragua and Trinidad. Here we analysed sequences of two genes, timeless and cpr, to assess the genetic variability and divergence among three sympatric cryptic species of this complex from Salobra, central-western Brazil. The timeless gene sequences did not conclusively differentiate Anopheles halophylus and An. triannulatus species "C". However, a partial separation has been observed between these species and An. triannulatus s.s. Importantly, the analysis of the cpr gene sequences revealed fixed differences, no shared polymorphisms and considerable genetic differentiation among the three species of the An. triannulatus complex. The results confirm that An. triannulatus s.s., An. halophylus and An. triannulatus species C are distinct taxa, with the latter two likely representing a more recent speciation event.
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Clinical and cellular consequences of the mutation m.12300G>A in the mitochondrial tRNA(Leu(CUN)) gene.
Mitochondrion
PUBLISHED: 04-13-2011
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We report, for the first time, a patient with an overlap MERRF-NARP syndrome who carries the mutation m.12300G>A in the mitochondrial tRNA(Leu(CUN)) gene. The mutation was heteroplamic and more abundant in her muscle and fibroblast than in blood from her oligosymptomatic mother. Single muscle fiber analysis revealed that the proportion of mutant mtDNA in ragged red fibers was higher than that in normal fibers. Combined defects of mitochondrial respiratory chain complexes were detected in muscle, fibroblasts and transmitochondrial hybrid cells. Significant reduction of total ATP and mitochondrial membrane potential and an increased production of reactive oxygen species were observed.
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The positive environmental contribution of jarosite by retaining lead in acid mine drainage areas.
Int J Environ Res Public Health
PUBLISHED: 04-09-2011
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Jarosite, KFe(3)(SO(4))(2)(OH)(6), is a secondary iron sulphate often found in acid mine drainage (AMD) environments, particularly in mining wastes from polymetallic sulphide ore deposits. Despite the negative environmental connotation usually ascribed to secondary sulphate minerals due to the release of hazardous elements to aquifers and soils, jarosite acts as an efficient remover and immobilizer of such metals, particularly lead. The mineral chemistry of jarosite is reviewed and the results of a Fe K-edge XANES (X-Ray Absorption Near-Edge Structure) study of K-, Na- and Pb-jarosite are described and discussed within the context of the abandoned old mines of São Domingos and Aljustrel located in southern Portugal, in the Iberian Pyrite Belt (IPB).
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Mitochondrial tRNA valine as a recurrent target for mutations involved in mitochondrial cardiomyopathies.
Mitochondrion
PUBLISHED: 03-28-2011
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The aim of this study was to identify the genetic defect in two patients having cardiac dysfunction accompanied by neurological symptoms, and in one case MRI evidence of cortical and cerebellar atrophy with hyperintensities in the basal ganglia. Muscle biopsies from each patient revealed single and combined mitochondrial respiratory chain deficiency. The complete mtDNA sequencing of both patients revealed two transitions in the mitochondrial tRNA(Val) gene (MT-TV) (m.1628C>T in Patient 1, and m.1644G>A in Patient 2). The functional and molecular analyses reported here suggest that the MT-TV gene should be routinely considered in the diagnosis of mitochondrial cardiomyopathies.
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Kinetics and mechanism of the electrochemical formation of iron oxidation products on steel immersed in sour acid media.
J Phys Chem B
PUBLISHED: 02-08-2011
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From electrochemical techniques (cyclic voltammetry, potential steps, and EIS), XRD, and SEM-EDX, the kinetics and mechanism of anodic film formation applying anodic potential steps on steel immersed in sour acid media was determined. It was found, from a thermodynamic analysis, based on equilibrium phase diagrams of the system considered in this work, that iron oxidation may produce different new solid phases, depending on the applied potential, the first being the iron oxidation associated with formation of FeS((c)) species, which in turn can be reoxidized to FeS(2(c)) or even to Fe(2)O(3(c)) at higher potential values. From analysis of the corresponding experimental potentiostatic current density transients, it was concluded that the electrochemical anodic film formation involves an E(1)CE(2) mechanism, whereby the first of the two simultaneous processes were the Fe electrochemical oxidation (E(1)) followed by FeS precipitation (C) that occurs by 3D nucleation and growth limited by mass transfer reaction and FeS oxidation (E(2)) forming a mix of different stoichiometry iron sulphides and oxides. From EIS measurements, it was revealed that the anodic films charge transfer resistance diminishes as the potential applied for its formation becomes more anodic, thus behaving poorly against corrosion.
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Genetic and phenotypic variation of the malaria vector Anopheles atroparvus in southern Europe.
Malar. J.
PUBLISHED: 01-11-2011
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There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, Anopheles atroparvus. Levels of population differentiation of An. atroparvus from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission.
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CORM-3 reactivity toward proteins: the crystal structure of a Ru(II) dicarbonyl-lysozyme complex.
J. Am. Chem. Soc.
PUBLISHED: 01-04-2011
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CORM-3, [fac-Ru(CO)(3)Cl(?(2)-H(2)NCH(2)CO(2))], is a well-known carbon monoxide releasing molecule (CORM) capable of delivering CO in vivo. Herein we show for the first time that the interactions of CORM-3 with proteins result in the loss of a chloride ion, glycinate, and one CO ligand. The rapid formation of stable adducts between the protein and the remaining cis-Ru(II)(CO)(2) fragments was confirmed by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Liquid-Chromatography Mass Spectrometry (LC-MS), Infrared Spectroscopy (IR), and X-ray crystallography. Three Ru coordination sites are observed in the structure of hen egg white lysozyme crystals soaked with CORM-3. The site with highest Ru occupancy (80%) shows a fac-[(His15)Ru(CO)(2)(H(2)O)(3)] structure.
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The influence of gender and of AIDS on the immunity of autopsied patients esophagus.
AIDS Res. Hum. Retroviruses
PUBLISHED: 11-23-2010
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Previous studies have shown that males who have AIDS are more frequently affected by infectious diseases than females. The esophagus is the organ in the digestive tube that is more commonly affected by opportunistic infections during the syndrome. The aim of this study was to assess the influence of AIDS and of gender on local immunity of the esophageal epithelium. Fragments of the esophagus from 29 autopsied women and 37 autopsied men were collected at a university hospital from 1980 to 2009 and were divided in groups with and without AIDS. The IgA-, IgG-, and IgM-positive cells and Langerhans cells (LCs) were immunostained, respectively, with anti-IgA, anti-IgG, anti-IgM, and anti-S100. The software Image J was used to measure the esophageal epithelium and to count the epithelium cellular layers. Patients with AIDS, apart from gender, showed an increase in IgA-, IgG-, and IgM-positive cells and a reduction of Langerhans cells, in thickness and in number of cellular layers in the esophageal epithelium. However, among individuals with AIDS, men presented lower secretory expression of IgA-, IgG-, and IgM-positive cells than women and more intense reduction of LCs. Women have naturally presented better local esophageal immunity than men. Although AIDS possibly causes immunological and morphological alterations in the esophageal epithelium in both genders, women have better esophageal immunity, which may explain a greater frequency of hospital admissions due to infection of men with AIDS when compared with women.
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Structural studies of biologically active glycosylated polyamidoamine (PAMAM) dendrimers.
J Mol Model
PUBLISHED: 09-15-2010
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The partial modification of carboxylic acid terminated polyamidoamine (PAMAM) dendrimers with glucosamine has been reported to give dendrimer glucosamine conjugates novel immuno-modulatory and anti-angiogenic properties. Experimental analysis of these glycosylated dendrimers showed that, on average, eight glucosamine molecules were covalently bound to each dendrimer. In order to better understand the surface loading and distribution of these glucosamine molecules, molecular reactivity was determined by evaluation of electronic properties using frontier molecular orbital theory (FMOT) and molecular dynamics simulations. It was shown that the surface loading and distribution of zero length amide bond-conjugated glucosamine molecules was determined by both electronic effects and by the different dynamic conformations adopted by the modified dendrimer during the incremental addition of glucosamine. Importantly, the structural features and the dynamic behavior of the partially glycosylated generation 3.5 PAMAM dendrimer showed that its flexibility and polarity changed with the incremental addition of glucosamine. These peripheral glucosamine molecules remained available on the dendrimers surface for interaction with the biological target.
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Monitoring Rhodotorula glutinis CCMI 145 physiological response and oil production growing on xylose and glucose using multi-parameter flow cytometry.
Bioresour. Technol.
PUBLISHED: 06-19-2010
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Flow cytometry was used to monitor the lipid content, viability and intrinsic light scatter properties of Rhodotorula glutinis CCMI 145 cells growing on batch cultures using xylose and glucose as carbon sources. The highest lipid content was observed for cells grown on glucose, at the end of the exponential phase (17.8% w/w). The proportion of cells stained with PI attaining 77% at the end of the glucose growth. Cells growing on xylose produced a maximum lipid content of 10.6% (w/w), at the stationary phase. An increase in the proportion of cells stained with PI was observed, reaching 29% at the end of xylose growth. Changes in the side and forward light scatter detected during the yeast batch cultures supported that R. glutinis cells grown on glucose experienced harsher conditions, resulting in a high level of cytoplasmic membrane damage, which did not occur when R. glutinis cells grew on xylose.
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VEGF blockade inhibits lymphocyte recruitment and ameliorates immune-mediated vascular remodeling.
Circ. Res.
PUBLISHED: 06-10-2010
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There are conflicting data on the effects of vascular endothelial growth factor (VEGF) in vascular remodeling. Furthermore, there are species-specific differences in leukocyte and vascular cell biology and little is known about the role of VEGF in remodeling of human arteries.
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Donor age and gestational age influence on growth factor levels in human amniotic membrane.
Acta Ophthalmol
PUBLISHED: 06-10-2010
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Amniotic membrane (AM) is used as a biomaterial for reconstruction in ocular surface surgery. This study investigated the influence of interdonor variations and processing and preservation procedures applied to the AM on growth factors and protein levels.
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Using multi-parameter flow cytometry to monitor the yeast Rhodotorula glutinis CCMI 145 batch growth and oil production towards biodiesel.
Appl. Biochem. Biotechnol.
PUBLISHED: 05-11-2010
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Multi-parameter flow cytometry was used to monitor cell intrinsic light scatter, viability, and lipid content of Rhodotorula glutinis CCMI 145 cells grown in shake flasks. Changes in the side light scatter and forward light scatter were detected during the yeast batch growth, which were attributed to the different yeast growth phases. A progressive increase in the proportion of cells stained with PI (cells with permeabilized cytoplasmic membrane) was observed during the yeast growth, attaining 79% at the end of the fermentation. A high correlation between the Nile Red fluorescence intensity measured by flow cytometry and total lipid content assayed by the traditional gravimetric lipid analysis was found for this yeast, making this method a suitable and quick technique for the screening of yeast strains for lipid production and optimization of biofuel production bioprocesses. Medium growth optimization for enhancement of the yeast oil production is now in progress.
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T cells, adhesion molecules and modulation of apoptosis in visceral leishmaniasis glomerulonephritis.
BMC Infect. Dis.
PUBLISHED: 05-11-2010
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Immune complex deposition is the accepted mechanism of pathogenesis of VL glomerulopathy however other immune elements may participate. Further in the present study, no difference was seen between immunoglobulin and C3b deposit intensity in glomeruli between infected and non-infected dogs thus T cells, adhesion molecules and parameters of proliferation and apoptosis were analysed in dogs with naturally acquired VL from an endemic area. The dog is the most important domestic reservoir of the protozoa Leishmania (L.) chagasi that causes visceral leishmaniasis (VL). The similarity of VL manifestation in humans and dogs renders the study of canine VL nephropathy of interest with regard to human pathology.
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Family 42 carbohydrate-binding modules display multiple arabinoxylan-binding interfaces presenting different ligand affinities.
Biochim. Biophys. Acta
PUBLISHED: 03-29-2010
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Enzymes that degrade plant cell wall polysaccharides display a modular architecture comprising a catalytic domain bound to one or more non-catalytic carbohydrate-binding modules (CBMs). CBMs display considerable variation in primary structure and are grouped into 59 sequence-based families organized in the Carbohydrate-Active enZYme (CAZy) database. Here we report the crystal structure of CtCBM42A together with the biochemical characterization of two other members of family 42 CBMs from Clostridium thermocellum. CtCBM42A, CtCBM42B and CtCBM42C bind specifically to the arabinose side-chains of arabinoxylans and arabinan, suggesting that various cellulosomal components are targeted to these regions of the plant cell wall. The structure of CtCBM42A displays a beta-trefoil fold, which comprises 3 sub-domains designated as alpha, beta and gamma. Each one of the three sub-domains presents a putative carbohydrate-binding pocket where an aspartate residue located in a central position dominates ligand recognition. Intriguingly, the gamma sub-domain of CtCBM42A is pivotal for arabinoxylan binding, while the concerted action of beta and gamma sub-domains of CtCBM42B and CtCBM42C is apparently required for ligand sequestration. Thus, this work reveals that the binding mechanism of CBM42 members is in contrast with that of homologous CBM13s where recognition of complex polysaccharides results from the cooperative action of three protein sub-domains presenting similar affinities.
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Functional splicing assay supporting that c.70 + 5G > A mutation in the MPV17 gene is disease causing.
J. Inherit. Metab. Dis.
PUBLISHED: 03-05-2010
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Mitochondrial DNA depletion syndrome (MDS) is a group of disorders characterized by a quantitative reduction of the mitochondrial DNA copy number and inherited as autosomal recessive traits. Patients affected by this group of diseases present with a wide variety of symptoms depending on the altered gene. MPV17 is one of the genes causing combined encephalopathy and liver failure and at present there is no treatment for this devastating disease. The gene codes for an inner mitochondrial membrane protein, but its function is still unknown, and therefore, the only way to offer prenatal diagnosis relies on DNA studies. Consequently, mutations have to be well characterized. We previously described a patient homozygous for a novel intronic mutation in the MPV17 gene (c.70 + 5G > A). Here we report the use of a functional splicing assay based on the use of minigenes to support that c.70 + 5G > A mutation is disease causing. We carried out three prenatal diagnoses on three consecutive pregnancies of the previously described family. After two affected fetuses, a healthy baby was born homozygous for the wild-type allele.
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Kearns-Sayre syndrome: cerebral folate deficiency, MRI findings and new cerebrospinal fluid biochemical features.
Mitochondrion
PUBLISHED: 03-05-2010
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We evaluated cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5-MTHF), biogenic amines, and white matter status in six Kearns-Sayre syndrome (KSS) patients. They presented severe 5-MTHF deficiency. A significant negative correlation was observed between CSF 5-MTHF and protein concentration. CSF homovanillic acid was clearly high. Regarding neuroimaging, the main feature was hyperintensity in the basal ganglia, brainstem, and cerebral/cerebellar white matter. The severity of hemispheric white matter disturbances appeared to be qualitatively associated with 5-MTHF values. The negative correlation between 5-MTHF and proteins supports the hypothesis of impaired choroid plexus function. Interestingly, despite very low 5-MTHF, clearly high neurotransmitter metabolites were found.
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Amperometric biosensor based on a high resolution photopolymer deposited onto a screen-printed electrode for phenolic compounds monitoring in tea infusions.
Talanta
PUBLISHED: 03-04-2010
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An amperometric biosensor based on laccase, from Trametes versicolor (LTV), was developed and optimized for monitoring the phenolic compounds content in tea infusions. The fungal enzyme was immobilized by entrapment within polyvinyl alcohol photopolymer PVA-AWP (azide-unit pendant water-soluble photopolymer) onto disposable graphite screen-printed electrodes (SPE). Sensitivity optimization in terms of pH, temperature and applied potential was carried out. The linear range, detection limit, operational and storage stabilities were also determined. The laccase biosensor (LTV-SPE) was calibrated for o-, m- and p-diphenol as well as caffeic acid. The highest response was found at 0.1M acetate buffer pH 4.7, though it must be added the good reproducibility and operational stability were also obtained. The useful lifetime of the biosensor is estimated to be greater than 6 months. LTV-SPE was used for the determination of the equivalent phenol content (EPC) in tea infusions by the direct addition into the electrochemical cell: the results were compared with those from the Folin-Ciocalteu spectrophotometric method. The amperometric detection exhibits some interesting advantages such as high simplicity, minimal sample preparation and shorter response time. A stable and sensitive amperometric response was obtained toward standard diphenolic compounds and herbal infusions. These biosensors are useful for easy and fast monitoring of EPC that can be related to the antioxidant capacity of natural extracts.
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[Open access to academic scholarship as a public policy resource: a study of the Capes database on Brazilian theses and dissertations.]
Hist Cienc Saude Manguinhos
PUBLISHED: 03-01-2010
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Access to scientific knowledge is a valuable resource than can inform and validate positions taken in formulating public policy. But access to this knowledge can be challenging, given the diversity and breadth of available scholarship. Communication between the fields of science and of politics requires the dissemination of scholarship and access to it. We conducted a study using an open-access search tool in order to map existent knowledge on a specific topic: agricultural contributions to the preservation of biodiversity. The present article offers a critical view of access to the information available through the Capes database on Brazilian theses and dissertations.
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Atopic dermatitis and ascariasis in children aged 2 to 10 years.
J Pediatr (Rio J)
PUBLISHED: 02-13-2010
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To assess the association between atopic dermatitis (AD) and ascariasis in 2 to 10-aged children from the neighborhood Pedregal, in the city of Campina Grande, Brazil, an area of low socioeconomic index.
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Serous borderline tumor of the fallopian tube presented as an adnexal mass.
Arch. Gynecol. Obstet.
PUBLISHED: 02-12-2010
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Serous tumors of low malignant potential (STLMP) of the fallopian tube are uncommon and their clinical behavior is poorly understood.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.