Non-heme Iron as Ferrous Sulfate Does Not Interact with Heme Iron Absorption in Humans

The absorption of heme iron has been described as distinctly different from that of non-heme iron. Moreover, whether heme and non-heme iron compete for absorption has not been well established. Our objective was to investigate the potential competition between heme and non-heme iron as ferrous sulfate for absorption, when both iron forms are ingested on an empty stomach. Twenty-six healthy nonpregnant women were selected to participate in two iron absorption studies using iron radioactive tracers. We obtained the dose?Cresponse curve for absorption of 0.5, 10, 20, and 50?mg heme iron doses, as concentrated red blood cells. Then, we evaluated the absorption of the same doses, but additionally we added non-heme iron, as ferrous sulfate, at constant heme/non-heme iron molar ratio (1:1). Finally, we compare the two curves by a two-way ANOVA. Iron sources were administered on an empty stomach. One factor analysis showed that heme iron absorption was diminished just by increasing total heme iron (P?<?0.0001). The addition of non-heme iron as ferrous sulfate did not have any effect on heme iron absorption (P?=?NS). We reported evidence that heme and non-heme iron as ferrous sulfate does not compete for absorption. The mechanism behind the absorption of these iron sources is not clear.     

Antimicrobial efficacy of alcohol-based hand gels with a 30-s application

Aims: The objective of this study was to assess the antimicrobial efficacy of alcohol‐based hand gels according to European Norm 1500 (EN 1500). Methods and Results: We assessed the antimicrobial efficacy of 12 alcohol‐based hand gels produced in Brazil, containing 70% w/w or v/v ethyl alcohol as the active ingredient, according to EN 1500, with a 30‐s application. In addition, 70% w/w ethyl alcohol and three alcohol‐based hand rubs commonly used in Europe and effective according to EN 1500 were also tested. Eight of 12 (67%) alcohol‐based hand gels produced in Brazil failed by EN 1500. In contrast, 70% w/w ethyl alcohol and European alcohol‐based hand rubs were approved by EN 1500. Conclusions: In this study, the majority of Brazilian alcohol‐based hand gels showed limited efficacy on hand hygiene within 30 s. Significance and Impact of the Study: The findings of this study may be used as an important argument to motivate Brazilian manufacturers to improve the antimicrobial efficacy of alcohol‐based hand gels, because it is prudent to suppose that alcohol‐based hand gels can be recommended for use in healthcare settings only if they show antimicrobial activity at least similar to that of alcohol‐based liquid preparations, including the traditional 70% w/w ethyl alcohol.     

Effects of compounds from Passiflora edulis Sims f. flavicarpa juice on blood coagulation and on proteolytic enzymes

Passion fruit (Passiflora edulis Sims f. flavicarpa) is popularly known for its sedative and calming properties and is consumed as a fresh fruit or as a juice. The clinical observation of blood incoagulability associated with excessive consumption of passion fruit juice, in a patient treated with warfarin, prompted the current study to investigate in vitro the presence of blood clotting inhibitors in Passiflora edulis Sims f. flavicarpa extract. After purification process, two compounds of distinct molecular weight and inhibitory action were better characterized. One is a trypsin inhibitor similar to inhibitors from Bowman-Birk family, named PeTI-I12, and other is a compound active in coagulation that prolongs aPTT and PT, but does not change TT. The aim of this study is to provide evidence that passion fruit extract's components play a role on hemostasis and therefore may be relevant in the handling of patients treated with anticoagulants or suffering hemorrhagic diseases.     

Central pharmacological activity of a new piperazine derivative: 4-(1-phenyl-1h-pyrazol-4-ylmethyl)-piperazine-1-carboxylic acid ethyl ester

AimsOur study focuses on the design and synthesis of a new piperazinic derivate, 4-(1-phenyl-1h-Pyrazol-4-Ylmethyl)-Piperazine-1-Carboxylic Acid Ethyl ester (LQFM008), and evaluation of its anxiolytic-like profile in Swiss mice.Main methodsLQFM008 was evaluated in a screening test of the central nervous system including the rota-rod, sodium pentobarbital-induced sleep, open field, elevated plus maze and light–dark box tests.Key findingsLQFM008 induced convulsions at the dose of 1.1 mmol/kg (i.p., s.c. or p.o.). LQFM008 up to 400 μmol/kg had no effect in the rota rod test. In the open field test, LQFM008 increased the number of crossings and the time spent at the central area as well as the sleeping time in sodium pentobarbital-induced sleep. In the elevated plus maze and light–dark box tests, this compound showed an anxiolytic-like activity. This anxiolytic-like activity was antagonized by NAN-190 (5-HT_1A antagonist) but not by flumazenil (benzodiazepine antagonist).SignificanceThe compound LQFM008 showed anxiolytic-like activity which may involve serotonergic pathway.     

Postglacial colonization of Europe by the barbastelle bat: agreement between molecular data and past predictive modelling

The barbastelle (Barbastella barbastellus) is a rare forest bat with a wide distribution in Europe. Here, we combine results from the analysis of two mtDNA fragments with species distribution modelling to determine glacial refugia and postglacial colonization routes. We also investigated whether niche conservatism occurs in this species. Glacial refugia were identified in the three southern European peninsulas: Iberia, Italy and the Balkans. These latter two refugia played a major role in the postglacial colonization process, with their populations expanding to England and central Europe, respectively. Palaeo‐distribution models predicted that suitable climatic conditions existed in the inferred refugia during the last glacial maximum (LGM). Nevertheless, the overlap between the current and the LGM distributions was almost inexistent in Italy and in the Balkans, meaning that B. barbastellus populations were forced to shift range between glacial and interglacial periods, a process that probably caused some local extinctions. In contrast, Iberian populations showed a ‘refugia within refugium’ pattern, with two unconnected areas containing stable populations (populations that subsisted during both glacial and interglacial phases). Moreover, the match between LGM models and the refugial areas determined by molecular analysis supported the hypothesis of niche conservatism in B. barbastellus. We argue that geographic patterns of genetic structuring, altogether with the modelling results, indicate the existence of four management units for conservation: Morocco, Iberia, Italy and UK, and Balkans and central Europe. In addition, all countries sampled possessed unique gene pools, thus stressing the need for the conservation of local populations.     

Effects of nutrient additions on plant biomass and diversity of the herbaceous-subshrub layer of a Brazilian savanna (Cerrado)

The Brazilian Cerrado is a diversity hotspot due to its high level of endemism and rapid loss of habitats. It is estimated that the number of herbaceous species is four times higher than that of woody species. Increasing levels of nitrogen additions to natural ecosystems have been indicated as a determinant of biodiversity loss. We investigated the effects of nutrient additions on the productivity (aboveground and belowground) and on diversity of the herbaceous-subshrub layer of a Brazilian savanna (cerrado stricto sensu). The experiment was carried out in the IBGE Ecological Reserve, near Brasília, Brazil. Between 1998 and 2006, N, P, N plus P, or Ca were applied to sixteen 225 m² plots, arranged in a completely randomized design. Aboveground biomass was compared 1 year after the first fertilization and 10 years later. Floristic diversity was significantly different (P < 0.01) between the treatments. The highest and lowest species richness were presented in control and NP, respectively. The addition of P alone or in combination with N induced invasion by Melinis minutiflora (exotic C₄ grass). The aboveground biomass of this species was higher in NP and P plots. In the N treatment, Echinolaena inflexa (native C₃ grass) presented elevated cover and biomass but M. minutiflora was absent. The invasion by alien species resulted in negative impacts on native grass species. Besides changes in aboveground biomass, addition of N and P also led, although to a lesser extent, to changes in the root morphology and biomass, but these responses were modulated by seasonal variation in soil moisture. The results suggest that environmental changes in nutrient availability can lead to important consequences for diversity and functioning of this savanna where the numerous rare species have more chance to persist under dystrophic conditions as some species that tend to be dominant would be less competitive.     

Technical evaluation of nested PCR for the diagnosis of experimental sporotrichosis

BackgroundSporotrichosis caused by the dimorphic fungus Sporothrix schenckii can presents in a variety of clinical forms. Routine diagnosis is made by mycology and serology studies. Few investigations have been focused on the evaluation of the molecular diagnosis.AimTo determine the value of the nested PCR technique for the diagnosis of experimental sporotrichosis in organs of mice, and to compare the results with the established laboratory diagnostic procedures.MethodsBALB/c mice were inoculated with growing concentrations of the 2 morphological phases of the fungus. The infected animals were sacrificed one month later and specimens from liver, spleen, lung and testicle were obtained to perform wet mount, culture and molecular diagnosis by the nested PCR technique. Blood samples were obtained for determination of specific antibodies against S. schenckii by the double immunodiffusion procedure.ResultsThe pathogenicity observed with the different concentrations of the fungus inoculated and its isolation by culture, showed scarce differences in the study of specimens from organs infected with the 2 morphological phases of S. schenckii. Specimens from organs of mice inoculated with the mycelial phase when studied by wet mount and culture, showed a higher positivity (100 and 37.5%) than those from mice inoculated with the yeast phase (73 and 2%). However, diagnosis by the nested PCR molecular technique applied to the latter specimens showed a higher percentage of positivity (75%) and 43% of positive results coming from animals infected with the mycelial phase. Specific antibody detection was positive in 100% all groups of infected mice.ConclusionsIn the study of experimental sporotrichosis in mice, the culture, as well as the antibody detection, was an effective diagnostic procedure, while the nested PCR and microscopic studies had a lower diagnostic value.     

High-throughput comparison of gene fitness among related bacteria

ABSTRACT: BACKGROUND: The contribution of a gene to the fitness of a bacterium can be assayed by whether and to what degree the bacterium tolerates transposon insertions in that gene. We use this fact to compare the fitness of syntenic homologous genes among related Salmonella strains to reveal differences not apparent at the gene sequence level. RESULTS: A transposon Tn5 derivative was used to construct mutants in Salmonella Typhimurium ATCC14028 (STM1) and Salmonella Typhi Ty2 (STY1), which were then grown in rich media. The locations of 234,152 and 53,556 integration sites, respectively, were mapped by sequencing. These data were compared to similar data available for a different Ty2 strain (STY2) and essential genes identified in E. coli K-12 (ECO). Of 277 genes considered essential in ECO, all had syntenic homologs in STM1, STY1, and STY2, and all but nine genes were either devoid of Tn insertions or had very few. For three of these nine genes, part of the annotated gene lacked Tn integrations (yejM, ftsN and murB). At least one of the other six genes, trpS, had a potentially functionally redundant gene encoded elsewhere in Salmonella but not in ECO. An additional 165 genes were almost entirely devoid of transposon integrations in all three Salmonella strains examined, including many genes associated with protein and DNA synthesis. Four of these genes (STM14_1498.L, STM14_2872, STM14_3360.RJ, and STM14_5442) are not found in E. coli. Notable differences in the extent of gene selection were also observed among the three different Salmonella isolates. Mutations in hns, for example, were selected against in STM1 but not in the two STY strains, which have a defect in rpoS rendering hns nonessential. CONCLUSIONS: Comparisons among transposon integration profiles from different members of a species and among related species, all grown in similar conditions, identify differences in gene fitness among syntenic homologous genes. Further differences in fitness profiles among shared genes can be expected in other selective environments, with potential relevance for comparative systems biology.     

Bayesian inference to study genetic control of resistance to gray leaf spot in maize

Gray leaf spot (GLS) is a major maize disease in Brazil that significantly affects grain production. We used Bayesian inference to investigate the nature and magnitude of gene effects related to GLS resistance by evaluation of contrasting lines and segregating populations. The experiment was arranged in a randomized block design with three replications and the mean values were analyzed using a Bayesian shrinkage approach. Additive-dominant and epistatic effects and their variances were adjusted in an over-parametrized model. Bayesian shrinkage analysis showed to be an excellent approach to handle complex models in the study of genetic control in GLS, since this approach allows to handle overparametrized models (main and epistatic effects) without using model-selection methods. Genetic control of GLS resistance was predominantly additive, with insignificant influence of dominance and epistasis effects.