979 resultados para Lice -- Genetic aspects


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Turmeric (Curcuma longa) is a triploid, vegetatively propagated crop introduced early during the colonization of Brazil. Turmeric rhizomes are ground into a powder used as a natural dye in the food industry, although recent research suggests a greater potential for the development of drugs and cosmetics. In Brazil, little is known about the genetic variability available for crop improvement. We examined the genetic diversity among turmeric accessions from a Brazilian germplasm collection comprising 39 accessions collected from the States of Goias, Mato Grosso do Sul, Minas Gerais, Sao Paulo, and Para. For comparison, 18 additional genotypes were analyzed, including samples from India and Puerto Rico. Total DNA was extracted from lyophilized leaf tissue and genetic analysis was performed using 17 microsatellite markers (single-sequence repeats). Shannon-Weiner indexes ranged from 0.017 (Minas Gerais) to 0.316 (Sao Paulo). Analyses of molecular variance (AMOVA) demonstrated major differences between countries (63.4%) and that most of the genetic diversity in Brazil is found within states (75.3%). Genotypes from Sao Paulo State were the most divergent and potentially useful for crop improvement. Structure analysis indicated two main groups of accessions. These results can help target future collecting efforts for introduction of new materials needed to develop more productive and better adapted cultivars.

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We evaluated the genetic and physiological variability of Moniliophthora perniciosa obtained from healthy and diseased branches of cacao (Theobroma cacao) plants. The diversity of the isolates was evaluated by RAPD technique and by studies of virulence and exoenzyme production. The genetic variability of endophytic and pathogenic M. perniciosa was evaluated in association with pathogenicity assays. RAPD analysis showed eight genetic groups, which were not related to plant disease status (healthy versus diseased branches). Isolates from cacao were included in three groups, excluding isolates from other host plants. Pathogenicity and enzyme analysis showed that the virulence of the isolates is not related to exoenzyme production. This is the first evidence that M. perniciosa colonizes healthy parenchymatic tissues, showing that endophytic behavior may occur in this species.

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The present research was conducted to estimate the genetic trends for meat quality traits in a male broiler line. The traits analyzed were initial pH, pH at 6 h after slaughter, final pH, initial range of falling pH, final range of falling pH, lightness, redness, yellowness, weep loss, drip loss, shrink loss, and shear force. The number of observations varied between 618 and 2125 for each trait. Genetic values were obtained by restricted maximum likelihood, and the numerator relationship matrix had 107,154 animals. The genetic trends were estimated by regression of the broiler average genetic values with respect to unit of time (generations), and the average genetic trend was estimated by regression coefficients. Generally, for the traits analyzed, small genetic trends were obtained, except for drip loss and shear force, which were higher. The small magnitude of the trends found could be a consequence of the absence of selection for meat quality traits in the line analyzed. The estimates of genetic trends obtained were an indication of an improvement in the meat quality traits in the line analyzed, except for drip loss.

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The aim of the present study was to evaluate the heterosis effects on weaning weight at 205 days (WW, N = 146,464), yearling weight at 390 days (YW, N = 69,315) and weight gain from weaning to yearling (WG, N = 59,307) in composite beef cattle. The fixed models were: RM, which included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and additive direct and maternal ( AM) breed effects; R, RM model, minus AM breed effects, and H, RM model, minus additive breed effects. The estimates for W205 were in general positive (P < 0.01). The R and H models resulted in similar estimates, but they were very different from the ones estimated by the RM model. For W390, the R and H models resulted in general positive estimates (P < 0.05). For WG, the RM model resulted in general significant heterosis effects (P < 0.05). It can be concluded that the RM model seems to supply estimates of better quality (P < 0.01).

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Through direct transmetalation reaction of Z-vinylic tellurides with nBuLi was observed the unexpected isomerization of double bonds leading to potassium E-vinyltrifluoroborates salts in low to moderate yields. Using EPR spin trapping experiments the radical species that promoted the stereoinversion of Z-vinylic organometallic species during the preparation of potassium vinyltrifluoroborate salts was identified. The experiments support the proposed mechanism, which is based on the homolytic cleavage of the TenBu bond.

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This study investigated the reproductive biology of the meloid beetle Meloetyphlus fuscatus Waterhouse, a cleptoparasite of Eulaema nigrita nests. New E. nigrita nests had rates of cell parasitism by meloids ranging from 3.7% to 15.8%, while in re-used nests the rate of cell parasitism ranged from 1.4% to 18.7%. The adult parasites were never observed trying to leave the host nests. Both sexes mated more than once. Females had a high fecundity (more than 8,000 eggs), and in most cases, deposited their eggs into the empty, old cells of the host. The triungulins (the first larval instars) hatched from eggs 18-20 days after oviposition and dispersed from the host nest by attaching themselves to males as they emerged. The triungulins most likely transfer to female bees during mating and are transported to the nests of their hosts. Within an attacked cell, the triungulin consumes the bee egg and completes its development by consuming the larval food stored in the cell.

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The freshwater prawn Macrobrachium amazonicum is widely distributed in South America, and occupies habitats with a wide range of salinities. Several investigations have revealed the existence of wide intraspecific variability among different populations, although the understanding of this variability is still fragmentary and incomplete. We compared and characterized inland and coastal populations of M. amazonicum from Brazil, using molecular data (16S and COI mtDNA) to describe the degree of variability, structure, and relationships among them. Genetic divergence rates among populations showed variability at the intraspecific level. All the analyses evidenced significant genetic divergence among populations, structuring them in three groups: I-inland waters of the Amazonian Hydrographic Region (HR); II-Parana/Paraguay HR; and III-coastal systems of northern and northeastern Brazil. Phylogenetic reconstructions revealed that the populations form a single monophyletic clade, which supports their characterization as a single species. Clade I was a sister clade of that formed by clades II and III, which were themselves sister clades. Populations from Sertaozinho/Miguelopolis and Avare, introduced into the state of Sao Paulo, may have originated from natural populations in the states of Mato Grosso do Sul and Para, respectively. Geographical isolation probably contributed to the observed variation, and if this isolation continues. M. amazonicum may undergo speciation within its broad geographical distribution. The sequences obtained here can be used as name-tags for population identification, and the DNA barcodes are useful to identify the origin of specimens used in different freshwater-prawn cultures or introduced populations of unknown origin.

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This paper emphasizes the important changes in Brazilian foreign policy after Luiz Inacio Lula da Silva took tip the power in 2002. The paper defends the idea that it is not possible to argue that there were deep changes in comparison to Cardoso's administration. However, evidence shows that new things are happening as regards the design of a more active and clear foreign action line which led to institutional changes and to more incisive multilateral paths. This results both from the political profile of the direct operators of foreign policy and the aims of lite presidential diplomacy, The hypothesis dealt with on this paper consists on the fact that Lula's administration has not fully broken with the old administration practices, however the aims of global and regional integration are being plotted more clearly and with a higher degree of activism. This becomes clear in three aspects of the Brazilian foreign policy: the institutional framework, the practice of multilateralism and the foreign policy towards the South, the three topics analyzed in this paper.

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Purpose: The aim is to evaluate the level of inclination of the surgeon's spinal column (ISSC) while performing laparoscopic radical prostatectomy (LRP) when using one trocar on each side of the patient abdomen (""torero"" position) in two scenarios: With and without a thin head supporter adapted to the table. Materials and Methods: Based on trigonometric principles, we elaborated a formula to calculate the ISSC for a determined surgeon and surgical table while performing LRP in the torero position. The parameters considered were the width of the surgical table (m), the distance between the surgeon's anterior superior iliac spines (q), and the distance from the central point between the surgeon's anterior superior iliac spines to the surgeon's head (h). We used the formula alpha = 90 degree-cos(-1)(b/h) (where b = q/2 + m/2) in an Excel sheet to calculate the angle of inclination of the surgeon's spinal column. We applied the measures of 12 surgeons with different biotypes of our staff to calculate the ISSC with and without the thin head supporter. Results: The use of a thin head supporter reduced the mean ISCC in the torero position from 36.1 +/- 3.73 degrees (range 31.3 to 49.8 degrees) to 22.1 +/- 4.9 degrees (range 18.7 to 32.9 degrees), which corresponds to a reduction of 38.8% in the mean angle of inclination. This difference was statistically significant (P < 0.001). Conclusion: The use of a thin head supporter adapted to the surgical table objectively reduces lateral inclination of the surgeon's spinal column in the torero position, making LRP a more comfortable procedure.

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Objective: To determine whether information from genetic risk variants for diabetes is associated with cardiovascular events incidence. Methods: From the about 30 known genes associated with diabetes, we genotyped single-nucleotide polymorphisms at the 10 loci most associated with type-2 diabetes in 425 subjects from the MASS-II Study, a randomized study in patients with multi-vessel coronary artery disease. The combined genetic information was evaluated by number of risk alleles for diabetes. Performance of genetic models relative to major cardiovascular events incidence was analyzed through Kaplan-Meier curve comparison and Cox Hazard Models and the discriminatory ability of models was assessed for cardiovascular events by calculating the area under the ROC curve. Results: Genetic information was able to predict 5-year incidence of major cardiovascular events and overall-mortality in non-diabetic individuals, even after adjustment for potential confounders including fasting glycemia. Non-diabetic individuals with high genetic risk had a similar incidence of events then diabetic individuals (cumulative hazard of 33.0 versus 35.1% of diabetic subjects). The addition of combined genetic information to clinical predictors significantly improved the AUC for cardiovascular events incidence (AUC = 0.641 versus 0.610). Conclusions: Combined information of genetic variants for diabetes risk is associated to major cardiovascular events incidence, including overall mortality, in non-diabetic individuals with coronary artery disease.

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The presence of mutations associated with integrase inhibitor (INI) resistance among INI-naive patients may play an important clinical role in the use of those drugs Samples from 76 HIV-1-infected subjects naive to INIs were submitted to direct sequencing. No differences were found between naive (25%) subjects and subjects on HAART (75%). No primary mutation associated with raltegravir or elvitegravir resistance was found. However, 78% of sequences showed at least one accessory mutation associated with resistance. The analysis of the 76 IN sequences showed a high polymorphic level on this region among Brazilian HIV-1-infected subjects, including a high prevalence of aa substitutions related to INI resistance. The impact of these findings remains unclear and further studies are necessary to address these questions.

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Background: The rapid progress currently being made in genomic science has created interest in potential clinical applications; however, formal translational research has been limited thus far. Studies of population genetics have demonstrated substantial variation in allele frequencies and haplotype structure at loci of medical relevance and the genetic background of patient cohorts may often be complex. Methods and Findings: To describe the heterogeneity in an unselected clinical sample we used the Affymetrix 6.0 gene array chip to genotype self-identified European Americans (N = 326), African Americans (N = 324) and Hispanics (N = 327) from the medical practice of Mount Sinai Medical Center in Manhattan, NY. Additional data from US minority groups and Brazil were used for external comparison. Substantial variation in ancestral origin was observed for both African Americans and Hispanics; data from the latter group overlapped with both Mexican Americans and Brazilians in the external data sets. A pooled analysis of the African Americans and Hispanics from NY demonstrated a broad continuum of ancestral origin making classification by race/ethnicity uninformative. Selected loci harboring variants associated with medical traits and drug response confirmed substantial within-and between-group heterogeneity. Conclusion: As a consequence of these complementary levels of heterogeneity group labels offered no guidance at the individual level. These findings demonstrate the complexity involved in clinical translation of the results from genome-wide association studies and suggest that in the genomic era conventional racial/ethnic labels are of little value.

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Background Tuberculosis clusters in families may be due to increased household exposure, shared genetic factors, or both. Household contact studies are useful to control exposure because socioeconomic and environmental conditions are similar to all subjects, allowing the evaluation of the contribution of relatedness to disease development. Methods In this study, the familial aggregation of tuberculosis using relatedness and a specific inherited marker (HLA-DRB1) was evaluated. Fifty families, which had at least two cases of tuberculosis diagnosed within the past 5 years, were selected from a cohort of tuberculosis carried out in Recife, Brazil. The first case diagnosed was considered to be a primary case. The secondary attack rate of tuberculosis in household contacts was estimated according to the degree of relatedness. The relative risk of having tuberculosis based on the degree of relatedness household and the population attributable fraction to relatedness were also estimated. HLA-DRB1 typing and attributable etiologic/preventive fractions were calculated among sick and healthy household contacts. Results Compared to unrelated contacts, the relative risk for tuberculosis adjusted for age was 1.38 (95% CI 0.86 to 2.21). Relatedness contributed 23% to the development of tuberculosis at the population levels. The HLA-DRB1*04 allele group (OR = 2.44; p =0.0324; etiologic fraction =0.15) was overrepresented and the DRB1*15 allele group (OR=0.48; p=0.0488; protective fraction=0.19) was underrepresented among household contacts exhibiting tuberculosis. The presence of DRB1 shared alleles between primary cases and their contacts was a risk factor for tuberculosis (p=0.0281). Conclusion This household contact model together with the utilisation of two genetic variables permitted the evaluation of genetic factors contributing towards tuberculosis development.

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Interethnic differences exist in disease prevalence, especially with regard to cancer and cardiovascular diseases, which involve altered expression or activity of matrix metalloproteinases (MMPs). The hypothesis being tested in this study is that interethnic differences exist between blacks and whites with regard to the distribution of genetic variants of MMP polymorphisms and haplotypes. We examined the distribution of polymorphisms of MMP-2 and MMP-9 genes in 177 black and 140 white subjects. We studied the following polymorphisms: the C(-1306)T in the promoter of the MMP-2 gene, the C(-1562)T and a microsatellite -90(CA)(14-24) in the promoter, and the Q279R in exon 6 of the MMP-9 gene. We have also compared our results with those from Hapmap or Seattle SNPs Projects and estimated the haplotype frequency in these two ethnic groups. The ""C'' allele for the C(-1306)T polymorphism was more common in blacks (91.5%) than in whites (80.4%; p<0.0001). The ""T'' allele for the C(-1562)T polymorphism was more common in blacks (15.0%) than in whites (8.9%; p=0.0279), as well as the alleles with >21 repeats for the -90(CA)(14-24) were more common in blacks than in whites (61.9% in blacks and 49.3% in whites; p=0.0017). We found no interethnic differences for the Q279R polymorphism. Moreover, two haplotypes that combine ""detrimental'' alleles were found at higher frequencies in blacks than in whites (31% vs. 16.4%, respectively; p<0.05). The interethnic differences being reported here replicate those previously found with smaller number of subjects in the Hapmap or Seattle SNPs data and may help explain the higher prevalence of cancer and cardiovascular diseases in blacks compared with whites. Our findings suggest a proportional significance of these polymorphisms in each ethnic group.