Diallel analysis and inbreeding depression of commercial maize hybrids aiming the formation of base populations

The development of base populations derived from high yield commercial hybrids is considered one of the main strategies to initiate a maize breeding program, mainly because these hybrids have already been tested in many environments, and so, associating high yield and a large proportion of favorable loci fixed. Therefore, the objective of the present study is to estimate the combining abilities and inbreeding depression of commercial maize hybrids for agronomic traits. Eighteen commercial hybrids divided in two groups accordingly to their respective companies, seventy-two F combinations from a partial diallel scheme, eighteen S populations and one check were evaluated in a randomized complete block design in two experiments, both in Sementes Balu Experimental Unit, Sabáudia (PR), Brazil, for growing seasons from 2011/2012 and 2012/2013. The Griffing method (1956), adapted to a partial diallel by Geraldi and Miranda Filho (1988) was applied for the evaluation of the general com- bining ability (GCA) and specific combining ability (SCA). The hybrids P1630, P4285, 30B39Y and DKB370 showed increased yield, and hybrids P1630, 32R22H, and DKB615 showed reduced plant and ear height. These hybrids can be recommended for the extraction of inbred lines and formation of composites followed by intrapopulation selection. The combinations P1630 x DKB330, P4285 x DKB245, 30F53 x DKB370, and 32R22H x DKB370 showed desirable SCA effects for grain yield and are recommended for use in interpopulation breeding programs. Among the hybrids with desirable GCA effects, 30B39Y showed the lowest inbreeding depression effect for the analyzed traits

HPV type infection in different anogenital sites among HIV-positive Brazilian women

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Factors Associated with Colposcopy-Histopathology Confirmed Cervical Intraepithelial Neoplasia among HIV-Infected Women from Rio De Janeiro, Brazil

Introduction: Despite the availability of preventive strategies (screening tests and vaccines), cervical cancer continues to impose a significant health burden in low- and medium-resourced countries. HIV-infected women are at increased risk for infection with human papillomavirus (HPV) and thus development of cervical squamous intraepithelial neoplasia (CIN). Methods:Study participants included HIV-infected women enrolling the prospective open cohort of Evandro Chagas Clinical Research Institute, Oswaldo Cruz Foundation (IPEC/FIOCRUZ). At cohort entry, women were subjected to conventional Papanicolaou test, HPV-DNA test and colposcopy; lesions suspicious for CIN were biopsied. Histopathology report was based on directed biopsy or on specimens obtained by excision of the transformation zone or cervical conization. Poisson regression modeling was used to assess factors associated with CIN2+diagnosis. Results:The median age of the 366 HIV-infected women included in the study was 34 years (interquartile range: 28–41 years). The prevalence of CIN1, CIN2 and CIN3 were 20.0%, 3.5%, and 2.2%, respectively. One woman was found to have cervical cancer. The prevalence of CIN2+was 6.0%. Factors associated with CIN2+diagnosis in the multivariate model were age,years compared to$35 years (aPR = 3.22 95CD4 T-cell count,350 cells/mm3 when compared to$350 cells/mm3 (aPR = 6.03 95%CI 1.50–24.3) and concomitant diagnosis of vulvar and/or vaginal intraepithelial lesion (aPR = 2.68 95%CI 0.99–7.24). Discussion:Increased survival through wide-spread use of highly active antiretroviral therapy might allow for the development of cervical cancer. In Brazil, limited cytology screening and gynecological care adds further complexity to the HIV-HPV co-infection problem. Integrated HIV care and cervical cancer prevention programs are needed for the prevention of cervical cancer mortality in this group of wome

Development and validation of a simple questionnaire for the identification of hereditary breast cancer in primary care

<p>Abstract</p> <p>Background</p> <p>Breast cancer is a significant public health problem worldwide and the development of tools to identify individuals at-risk for hereditary breast cancer syndromes, where specific interventions can be proposed to reduce risk, has become increasingly relevant. A previous study in Southern Brazil has shown that a family history suggestive of these syndromes may be prevalent at the primary care level. Development of a simple and sensitive instrument, easily applicable in primary care units, would be particularly helpful in underserved communities in which identification and referral of high-risk individuals is difficult.</p> <p>Methods</p> <p>A simple 7-question instrument about family history of breast, ovarian and colorectal cancer, FHS-7, was developed to screen for individuals with an increased risk for hereditary breast cancer syndromes. FHS-7 was applied to 9218 women during routine visits to primary care units in Southern Brazil. Two consecutive samples of 885 women and 910 women who answered positively to at least one question and negatively to all questions were included, respectively. The sensitivity, specificity and positive and negative predictive values were determined.</p> <p>Results</p> <p>Of the 885 women reporting a positive family history, 211 (23.8%; CI95%: 21.5–26.2) had a pedigree suggestive of a hereditary breast and/or breast and colorectal cancer syndrome. Using as cut point one positive answer, the sensitivity and specificity of the instrument were 87.6% and 56.4%, respectively. Concordance between answers in two different applications was given by a intra-class correlation (ICC) of 0.84 for at least one positive answer. Temporal stability of the instrument was adequate (ICC = 0.65).</p> <p>Conclusion</p> <p>A simple instrument for the identification of the most common hereditary breast cancer syndrome phenotypes, showing good specificity and temporal stability was developed and could be used as a screening tool in primary care to refer at-risk individuals for genetic evaluations.</p

Evidence for Divergent Evolution of Growth Temperature Preference in Sympatric Saccharomyces Species

The genus Saccharomyces currently includes eight species in addition to the model yeast Saccharomyces cerevisiae, most of which can be consistently isolated from tree bark and soil. We recently found sympatric pairs of Saccharomyces species, composed of one cryotolerant and one thermotolerant species in oak bark samples of various geographic origins. In order to contribute to explain the occurrence in sympatry of Saccharomyces species, we screened Saccharomyces genomic data for protein divergence that might be correlated to distinct growth temperature preferences of the species, using the dN/dS ratio as a measure of protein evolution rates and pair-wise species comparisons. In addition to proteins previously implicated in growth at suboptimal temperatures, we found that glycolytic enzymes were among the proteins exhibiting higher than expected divergence when one cryotolerant and one thermotolerant species are compared. By measuring glycolytic fluxes and glycolytic enzymatic activities in different species and at different temperatures, we subsequently show that the unusual divergence of glycolytic genes may be related to divergent evolution of the glycolytic pathway aligning its performance to the growth temperature profiles of the different species. In general, our results support the view that growth temperature preference is a trait that may have undergone divergent selection in the course of ecological speciation in Saccharomyces