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281.
Worm infection is one of the main factors responsible for economic losses in sheep breeding in Brazil. Random regression analysis was used to estimate genetic parameters for the factors faecal egg-count (FEC), packed-cell volume (PCV) and body weight (BW) in Santa Inês lambs. Data from 119 female, offspring of nine rams, were collected between December, 2005 and December, 2006, from the experimental flock of Embrapa Tabuleiros Costeiros, the Brazilian Agricultural Research Corporation located in Frei Paulo, SE, Brazil. After weaning, females were drenched until the faecal egg count had dropped to zero. Two natural challenges were undertaken. FEC heritability was extremely variable, this increasing from 0.04 to 0.27 in the first challenge and from 0.01 to 0.52 during the second. PCV heritability peaks were 0.31 and 0.12 in the first and second challenges, respectively. In the second challenge, BW heritability was close to 0.90. The genetic correlations among these traits did not differ from zero. There is the possibility of increasing parasite resistance in Santa Inês by selecting those animals with lower FEC. Selection to increase resistance will not adversely affect lamb-growth, although lambs with a slow growth-rate may be more susceptible to infection.  相似文献   
282.
Magnetic effects induced in ethanolic fermentation by Saccharomyces cerevisiae strain DAUFPE-1012 were studied during a 24 h exposure to 220 mT steady magnetic fields (SMF) at 23 +/- 1 degrees C, produced by NdFeB rod magnets. The magnets were attached diametrically opposed (N to S) to a cylindrical tube reactor. The biomass growth in the reactor culture media (yeast extract + glucose 2%) during 24 h was monitored by measurements of optical density, which was correlated to cell dry weight. Ethanol concentration and glucose level were measured every 2 h. The pH of the culture media was maintained between 4 and 5. As a result, biomass (g/L) increased 2.5-fold and ethanol concentration 3.4-fold in magnetized cultures (n = 8) as compared with SMF nonexposed cultures (n = 8). Glucose consumption was higher in magnetized cultures, which correlated to the ethanol yield.  相似文献   
283.

Background

Multiple micronutrients in powder (MNP) are recommended by WHO to prevent anemia in young children. However, evidences for its effectiveness in different populations and improvements in other outcomes (e.g. linear growth and vitamin A deficiency) are scarce.

Methods

A multicentre pragmatic controlled trial was carried out in primary health centres. At study baseline, a control group (CG) of children aged 10- to 14 months (n = 521) was recruited in the routine healthcare for assessing anemia, anthropometric and micronutrient status. At the same time, an intervention group (IG) of infants aged 6- to 8 months (n = 462) was recruited to receive MNP daily in complementary feeding over a period of 60 days. Both study groups were compared when the IG infants reached the age of the CG children at enrolment.

Results

In CG, the prevalence of anemia [hemoglobin (Hb) < 110 g/L], iron deficiency (ID, plasma ferritin < 12 μg/L or TfR > 8.3 mg/L), and vitamin A deficiency (VAD, serum retinol < 0.70μmol/L) were 23.1%, 37.4%, and 17.4%, respectively. Four to six months after enrolment, when the IG participants had the same age of the controls at the time of testing, the prevalence of anemia, ID and VAD in IG were 14.3%, 30.1% and 7.9%, respectively. Adjusting for city, health centre, maternal education, and age, IG children had a lower likelihood of anemia and VAD [Prevalence Ratio (95% CI) = 0.63 (0.45, 0.88) and 0.45 (0.29, 0.69), respectively] when compared with CG children. The adjusted mean distributions of Hb and length-for-age Z-scores improved by 2 SE in the IG compared to CG children.

Conclusions

MNP effectively reduced anemia and improved growth and micronutrient status among young Brazilian children.

Trial Registration

Registro Brasileiro de Ensaios Clinicos RBR-5ktv6b  相似文献   
284.
ABSTRACT

Recent findings of atomic-scale modelling studies are reviewed on graphene derivatives and metamaterials fabricated through chemical functionalization and/or defect engineering of graphene sheets. Results of molecular-statics and molecular-dynamics simulations according to a reliable bond-order potential, as well as first-principles density functional theory calculations are reviewed that have established useful structure-properties relations in two-dimensional materials, such as graphene nanomeshes (GNMs), electron-irradiated graphene, and interlayer-bonded twisted bilayer graphene. Quantitative relationships are established for the elastic moduli, mechanical properties, and thermal conductivity of GNMs as a function of the nanomesh porosity and the mechanical response of GNMs to uniaxial tensile straining is explored over the range of nanomesh porosities. The dependence of structural, mechanical, and thermal transport properties of electron-irradiated graphene sheets on the density of irradiation-induced defects is reviewed, highlighting an amorphization transition accompanied by a brittle-to-ductile transition and a transition in thermal transport mechanism beyond a critical defect concentration. The tunability of the electronic band structure, mechanical properties, and structural response to mechanical loading of graphene-diamond nanocomposite superstructures consisting of nanodiamond superlattices in interlayer-bonded twisted bilayer graphene also is demonstrated by precise control of the density and distribution of covalent interlayer C–C bonds.  相似文献   
285.
Identifying new target molecules through which eosinophils secrete their stored proteins may reveal new therapeutic approaches for the control of eosinophilic disorders such as host immune responses to parasites. We have recently reported the expression of the purinergic P2Y12 receptor (P2Y12R) in human eosinophils; however, its functional role in this cell type and its involvement in eosinophilic inflammation remain unknown. Here, we investigated functional roles of P2Y12R in isolated human eosinophils and in a murine model of eosinophilic inflammation induced by Schistosoma mansoni (S. mansoni) infection. We found that adenosine 5’-diphosphate (ADP) induced human eosinophils to secrete eosinophil peroxidase (EPO) in a P2Y12R dependent manner. However, ADP did not interfere with human eosinophil apoptosis or chemotaxis in vitro. In vivo, C57Bl/6 mice were infected with cercariae of the Belo Horizonte strain of S. mansoni. Analyses performed 55 days post infection revealed that P2Y12R blockade reduced the granulomatous hepatic area and the eosinophilic infiltrate, collagen deposition and IL-13/IL-4 production in the liver without affecting the parasite oviposition. As found for humans, murine eosinophils also express the P2Y12R. P2Y12R inhibition increased blood eosinophilia, whereas it decreased the bone marrow eosinophil count. Our results suggest that P2Y12R has an important role in eosinophil EPO secretion and in establishing the inflammatory response in the course of a S. mansoni infection.  相似文献   
286.
Chemokines are an important group of soluble molecules with specialized functions in inflammation. The roles of many specialized chemokines and their receptors remain poorly understood in the human intervertebral disc. We investigated CXCL16 and its receptor, CXCR6, to determine their immunolocalization in disc tissue and their presence following exposure of cultured human annulus fibrosus cells to proinflammatory cytokines. CXCL16 is a marker for inflammation; it also can induce hypoxia-inducible factor 1α (HIF-1α), which is a phenotypic marker of heathy nucleus pulposus tissue. We found CXCL16 and CXCR6 immunostaining in many cells of the annulus portion of the disc. Molecular studies showed that annulus fibrosus cells exposed to IL-1ß, but not TNF-α, exhibited significant up-regulation of CXCL16 expression vs. control cells. There was no significant difference in the percentage of annulus cells that exhibited immunolocalization of CXCL16 in grade I/II, grade III or grade IV/V specimens. The presence of CXCL16 and its receptor, CXCR6, in the annulus in vivo suggests the need for future research concerning the role of this chemokine in proinflammatory functions, HIF-1α expression and disc vascularization.  相似文献   
287.
Monomeric IgA has been proposed as an alternative antibody format for cancer therapy. Here, we present our studies on the production, purification and functional evaluation of anti-HER2 IgA antibodies as anti-cancer agents in comparison to the anti-HER2 IgG1 trastuzumab. MALDI-TOF MS analysis showed profound differences in glycosylation traits across the IgA isotypes and cell lines used for production, including sialylation and linkage thereof, fucosylation (both core and antennary) and the abundance of high-mannose type species. Increases in sialylation proved to positively correlate with in vivo plasma half-lives. The polymerization propensity of anti-HER2 IgA2m2 could be suppressed by an 18-aa deletion of the heavy chain tailpiece - coinciding with the loss of high-mannose type N-glycan species - as well as by 2 cysteine to serine mutations at positions 320 and 480. The HER2 F(ab')2-mediated anti-proliferative effect of the IgA2m1 and IgA2m2 subtypes was similar to IgG1, whereas the IgA1 isotype displayed considerably lower potency and efficacy. The Fc-mediated induction of antibody-dependent cell-mediated cytotoxicity (ADCC) using human whole blood ADCC assays did not demonstrate such clear differences between the IgA isotypes. However, the potency of the anti-HER2 IgA antibodies in these ADCC assays was found to be significantly lower than that of trastuzumab. In vivo anti-tumor activity of the anti-HER2 IgA antibodies was compared to that of trastuzumab in a BT-474 breast cancer xenograft model. Multiple dosing and sialylation of the IgA antibodies compensated for the short in vivo half-life of native IgA antibodies in mice compared to a single dose of IgG1. In the case of the IgA2m2 antibody, the resulting high plasma exposure levels were sufficient to cause clear tumor stasis comparable to that observed for trastuzumab at much lower plasma exposure levels.  相似文献   
288.
This paper analyzes the spatial and temporal effects of a freshwater discharge (Andreoni Canal) on polychaete assemblages and the corresponding habitat in a sandy beach of Uruguay. Bimonthly, we examined 17 environmental variables plus polychaete abundance, richness, and diversity of three sites: ‘Andreoni’ (highly disturbed) at the canal mouth, ‘Coronilla’ (moderately disturbed), 1 km far away, and ‘Barra del Chuy’ (less disturbed), 13 km north from Andreoni Canal. The highly disturbed site showed significantly lower values of salinity, beach width, swash width, slope, chlorophyll a, and significantly higher values of sediment organic matter. Polychaete abundance and diversity significantly decreased towards the canal and were positively correlated with spatial variations in salinity, which was the most important factor structuring polychaete assemblages. The results highlighted the negative effects of this artificial freshwater discharge on the sandy beach environment and stress the usefulness of polychaetes as effective and reliable ecological indicators for these ecosystems.  相似文献   
289.
Histoplasma capsulatum is very prevalent in the environment and is one of the most common causes of mycoses in humans and diverse animals in Brazil. Multiple typing methods have been developed to study H. capsulatum epidemiology; however, there is limited information concerning comparisons of results obtained with different methods using the same set of isolates. To explore the diversity of H. capsulatum in Brazil and to determine correlations between the results of three different molecular typing techniques, we examined 51 environmental, animal, and human isolates by M13 PCR fingerprinting, PCR-restriction fragment length polymorphism (RFLP) analysis of the internal transcribed region 1 (ITS1)-5.8S-ITS2 region of the rDNA locus, and DNA sequencing and phylogenetic analysis of parts of four protein-encoding genes, the Arf (ADP ribosylation factor), H-anti (H antigen precursor), Ole (delta-9 fatty acid desaturase), and Tub1 (alpha-tubulin) genes. Each method identified three major genetic clusters, and there was a high level of concordance between the results of the typing techniques. The M13 PCR fingerprinting and PCR-RFLP analyses produced very similar results and separated the H. capsulatum isolates included in this study into three major groups. An additional approach used was comparison of our Brazilian ITS1-5.8S-ITS2 sequences with the sequences deposited previously in NCBI data banks. Our analyses suggest that H. capsulatum can be divided into different molecular types that are dispersed around the world. Our results indicate that the three methods used in this study are reliable and reproducible and that they have similar sensitivities. However, M13 PCR fingerprinting has some advantages over the other two methods as it is faster, cheaper, and more user friendly, which especially increases its utility for molecular typing of Histoplasma in situations where laboratory facilities are relatively limited.Histoplasmosis is a serious community-acquired infection in the United States (28) and in certain countries of Latin America, where it is an especially significant problem in patients with AIDS (14). This disease is one of the most common systemic mycoses in Brazil, where epidemiological surveys carried out using the histoplasmin skin test have indicated that it is endemic in all areas surveyed (15). Data suggest that the numbers of cases of histoplasmosis in Brazil may be underestimated and that the areas where it is endemic are more widespread than previously thought.Histoplasma capsulatum is a dimorphic fungus that grows as a mold and produces aerial hyphae at 25 to 30°C, but it undergoes morphogenesis to a yeast phase at 37°C. The filamentous phase of this organism is usually found in soil enriched with several compounds, such as nitrogen and phosphate compounds. When conidial or hyphal fragments are inhaled by humans or animals, H. capsulatum changes to the yeast form and continues to replicate as a yeast. Although H. capsulatum has been recognized as an important fungal pathogen in immunocompromised hosts, particularly AIDS patients (27), there are significant gaps in our knowledge of this species'' epidemiology and pathogenesis. For instance, systemic histoplasmosis has been found in patients with AIDS who do not reside in regions where it is endemic (29), leading to the suggestion that the disease can result from reactivation of a previously acquired H. capsulatum infection. The clinical manifestations of histoplasmosis range from asymptomatic infections, mild flu-like symptoms, or pneumonia to a systemic disease involving the skin, brain, intestine, adrenal glands, and/or bone marrow (6). Importantly, diverse strains of H. capsulatum have been identified worldwide, and the strains vary in virulence. In addition to classical biochemical assays, distinctions between strains may be based on colony morphology or polymorphism of the genome (19).Multiple typing methods have been developed to study the epidemiology of H. capsulatum. These methods are based on phenotypic characteristics, such as antigenic profiles (13) and multilocus enzyme electrophoresis results (2), or on DNA-based analysis. Most recently, typing has been accomplished by analysis of fatty acid profiles of H. capsulatum (34). Molecular typing methods are generally considered to have advantages over phenotypic methods in terms of the stability of genomic markers and greater levels of typeability. Several genotype-based methods, such as hybridization of target genes (probes), chromosomal DNA typing, restriction fragment length polymorphism (RFLP) analysis, random amplified polymorphic DNA (RAPD) analysis, and sequencing, have been described for H. capsulatum (4, 5, 7, 8, 11, 17, 19). Despite the abundance of previously developed molecular techniques, there is limited information concerning comparisons of the results obtained with different methods using the same set of isolates. In H. capsulatum, no single approach based on DNA assays has been the dominant method.The current study was done to explore the diversity of H. capsulatum in Brazil and to determine the correlation between the results of three different molecular typing techniques. For this analysis, we used M13 PCR fingerprinting, PCR-RFLP analysis of the internal transcribed spacer 1 (ITS1)-5.8S-ITS2 region of the rDNA gene, and analysis of the nucleotide sequence polymorphism of four partial genes. M13 PCR fingerprinting (25) is based on generation of multiple PCR products with different electrophoretic mobilities. PCR fingerprinting primers are typically designed using repetitive DNA sequences (31), and the products facilitate detection of two types of genetic variations: (i) differences in the length of DNA and (ii) alterations in the sequence of the priming regions. PCR-RFLP analysis of the ITS1-5.8S-ITS2 region of the rDNA gene (9) involves use of a gene-specific PCR in combination with restriction digestion in order to generate highly stable and reproducible markers. Analysis of the nucleotide sequence polymorphism is based on the sequences of four partial protein-encoding genes (Arf, the H-anti gene, Ole, Tub1) (4). Additionally, to assess the utility of an assay to study the global epidemiology of the fungus, we performed a DNA sequencing analysis of the ITS1-5.8S-ITS2 region to compare the Brazilian H. capsulatum ITS1-5.8S-ITS2 sequences with sequences obtained for H. capsulatum strains isolated in other countries.  相似文献   
290.
Seventeen polymorphic microsatellite loci were identified for white-faced capuchin monkeys from an enriched genomic library in addition to one locus found through cross-species comparisons. In a sample of 187 wild individuals, these loci exhibited an average of five alleles and an observed heterozygosity of 0.62. The combined probability of exclusion of a random individual from parentage was 0.99. These loci were screened in 23 other New World monkeys and an average of seven loci was variable per species, suggesting that these loci could be of use in studies of other Neotropical primates.  相似文献   
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