High-Performance Liquid Chromatography Under Partially Denaturing Conditions (dHPLC) is a Fast and Cost-Effective Method for Screening Molecular Defects: Four Novel Mutations Found in X-Linked Chronic Granulomatous Disease

Implementing precise techniques in routine diagnosis of chronic granulomatous disease (CGD), which expedite the screening of molecular defects, may be critical for a quick assumption of patient prognosis. This study compared the efficacy of single-strand conformation polymorphism analysis (SSCP) and high-performance liquid chromatography under partially denaturing conditions (dHPLC) for screening mutations in CGD patients. We selected 10 male CGD patients with a clinical history of severe recurrent infections and abnormal respiratory burst function. gDNA, mRNA and cDNA samples were prepared by standard methods. CYBB exons were amplified by PCR and screened by SSCP or dHPLC. Abnormal DNA fragments were sequenced to reveal the nature of the mutations. The SSCP and dHPLC methods showed DNA abnormalities, respectively, in 55% and 100% of the cases. Sequencing of the abnormal DNA samples confirmed mutations in all cases. Four novel mutations in CYBB were identified which were picked up only by the dHPLC screening (c.904 insC, c.141+5 g>t, c.553 T>C, and c.665 A>T). This work highlights the relevance of dHPLC, a sensitive, fast, reliable and cost-effective method for screening mutations in CGD, which in combination with functional assays assessing the phagocyte respiratory burst will contribute to expedite the definitive diagnosis of X-linked CGD, direct treatment, genetic counselling and to have a clear assumption of the prognosis. This strategy is especially suitable for developing countries.

Brazilian exchange rate complexity: Financial crisis effects

With the financial market globalization, foreign investments became vital for the economies, mainly in emerging countries. In the last decades, Brazilian exchange rates appeared as a good indicator to measure either investors' confidence or risk aversion. Here, some events of global or national financial crisis are analyzed, trying to understand how they influenced the "dollar-real" rate evolution. The theoretical tool to be used is the Lopez-Mancini-Calbet (LMC) complexity measure that, applied to real exchange rate data, has shown good fitness between critical events and measured patterns. (C) 2011 Elsevier B.V. All rights reserved.

Morphology and Involution of the Yolk Sac during Early Gestation Bovine (Bos indicus)

Background: The bovine yolk sac derives from visceral endoderm and its development occurs between days 18-23 of gestation. The study of this membrane is important for comparative data and has already been performed in rodents, sheep and in cattle, especially Bos taunts. In species Bos indicus the yolk sac has not quite been studied and is believed that there are morphological differences between these species. The yolk sac undergoes a process of involution and degeneration during embryonic development and none vestige of it is found in late gestation. The period in which occurs the involution of the yolk sac coincides with the period of increased pregnancy loss in cattle, and changes in the morphology of this membrane may indicate the reasons for such high loss rates. Thus, considering that the yolk sac is important for embryonic circulation and metabolic transmission, besides participating actively in the process of cattle placentation, this study aimed characterize morphologically the involution of the bovine yolk sac. Materials, Methods & Results: The early gestational period was determined between days 20 and 70 post-insemination (p.i), according to the exterior characteristics of embryo/fetus. For macroscopic analyzes the uterus was dissected to expose the fetal membranes and subsequently the embryo/fetus was photographed. The samples were fixed for light microscopy and transmission electron microscopy. The yolk sac that emerges from the ventral part of the embryo was prominent and composed by a central part with two thin peripheral projections of different lengths. The bovine yolk sac with about 9 cm on day 25 p. i. of pregnancy permanently decreased its total length during this study. Histologically, the yolk sac is composed of three cell layers: the mesothelium, the mesenchyme and the endoderm. In mesenchyme are found blood islets. In the endoderm are formed cells invaginations toward the mesenchyme originating small canaliculi. The ultrastructure of yolk cells presented many mitochondria, rough endoplasmic reticulum, vesicles, euchromatin and the presence of two nucleoli, Discussion: The real first blood circulation in the bovine is attached with the development of yolk sac, differently from other membranes, such as the corium, that does not present evidence of vascularization by the age of 20-30 days. The erythroblasts found in the yolk sac are related to vasculogenesis and the process of differentiation of blood cells during the erythropoiesis. It could be observed on the histology of the yolk sac, in embryos of 30-50 days old, the presence of canaliculi and small folds of the epithelium. The canaliculi collapse is associated with the degeneration of the endoderm wall of the yolk sac. The organelles present in the endoderm cells of the yolk sac are associated with the function of protein metabolism and in the exchange of substances between the mesenchyme and the mesothelium, For these findings, could be observed that the yolk sac epithelium is found active until the 50th day of gestation, and thereafter regresses. However, remnants of this membrane may be present until the 70th day, These features may represent a presence of an active chorionvitelline placenta in this period responsible for the maintenance of pregnancy whereas the chorioallantoic placenta is not definitively established.

The impact of the Bolsa Escola/Familia conditional cash transfer program on enrollment, dropout rates and grade promotion in Brazil

We examine the impact of Brazil's Bolsa Escola/Familia program on Brazilian children's education outcomes. Bolsa provides cash payments to poor households if their children (ages 6 to 15) are enrolled in school. Using school census data to compare changes in enrollment, dropping out and grade promotion across schools that adopted Bolsa at different times, we estimate that the program has: increased enrollment by about 5.5% (6.5%) in grades 1-4 (grades 5-8); lowered dropout rates by 0.5 (0.4) percentage points in grades 1-4 (grades 5-8); and raised grade promotion rates by 0.9 (0.3) percentage points in grades 1-4 (grades 5-8). About one third of Brazil's children participate in Bolsa, so assuming no spillover effects onto non-participants implies that Bolsa's impacts are three times higher than these estimates. However, simple calculations using enrollment impacts suggest that Bolsa's benefits in terms of increased wages may not exceed its costs. (C) 2011 Elsevier B.V. All rights reserved.

Rates of Change in the Visual Field and Optic Disc in Patients with Distinct Patterns of Glaucomatous Optic Disc Damage

Purpose: To investigate the rate of visual field and optic disc change in patients with distinct patterns of glaucomatous optic disc damage. Design: Prospective longitudinal study. Participants: A total of 131 patients with open-angle glaucoma with focal (n = 45), diffuse (n = 42), and sclerotic (n = 44) optic disc damage. Methods: Patients were examined every 4 months with standard automated perimetry (SAP, SITA Standard, 24-2 test, Humphrey Field Analyzer, Carl Zeiss Meditec, Dublin, CA) and confocal scanning laser tomography (CSLT, Heidelberg Retina Tomograph, Heidelberg Engineering GmbH, Heidelberg, Germany) for a period of 4 years. During this time, patients were treated according to a predefined protocol to achieve a target intraocular pressure (IOP). Rates of change were estimated by robust linear regression of visual field mean deviation (MD) and global optic disc neuroretinal rim area with follow-up time. Main Outcome Measures: Rates of change in MD and rim area. Results: Rates of visual field change in patients with focal optic disc damage (mean -0.34, standard deviation [SD] 0.69 dB/year) were faster than in patients with sclerotic (mean - 0.14, SD 0.77 dB/year) and diffuse (mean + 0.01, SD 0.37 dB/year) optic disc damage (P = 0.003, Kruskal-Wallis). Rates of optic disc change in patients with focal optic disc damage (mean - 11.70, SD 25.5 x 10(-3) mm(2)/year) were faster than in patients with diffuse (mean -9.16, SD 14.9 x 10(-3) mm(2)/year) and sclerotic (mean -0.45, SD 20.6 x 10(-3) mm(2)/year) optic disc damage, although the differences were not statistically significant (P = 0.11). Absolute IOP reduction from untreated levels was similar among the groups (P = 0.59). Conclusions: Patients with focal optic disc damage had faster rates of visual field change and a tendency toward faster rates of optic disc deterioration when compared with patients with diffuse and sclerotic optic disc damage, despite similar IOP reductions during follow-up. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. Ophthalmology 2012; 119: 294-303 (C) 2012 by the American Academy of Ophthalmology.

A note on the use of the generalized odds ratio in meta-analysis of association studies involving bi- and tri-allelic polymorphisms

Abstract Background The generalized odds ratio (GOR) was recently suggested as a genetic model-free measure for association studies. However, its properties were not extensively investigated. We used Monte Carlo simulations to investigate type-I error rates, power and bias in both effect size and between-study variance estimates of meta-analyses using the GOR as a summary effect, and compared these results to those obtained by usual approaches of model specification. We further applied the GOR in a real meta-analysis of three genome-wide association studies in Alzheimer's disease. Findings For bi-allelic polymorphisms, the GOR performs virtually identical to a standard multiplicative model of analysis (e.g. per-allele odds ratio) for variants acting multiplicatively, but augments slightly the power to detect variants with a dominant mode of action, while reducing the probability to detect recessive variants. Although there were differences among the GOR and usual approaches in terms of bias and type-I error rates, both simulation- and real data-based results provided little indication that these differences will be substantial in practice for meta-analyses involving bi-allelic polymorphisms. However, the use of the GOR may be slightly more powerful for the synthesis of data from tri-allelic variants, particularly when susceptibility alleles are less common in the populations (≤10%). This gain in power may depend on knowledge of the direction of the effects. Conclusions For the synthesis of data from bi-allelic variants, the GOR may be regarded as a multiplicative-like model of analysis. The use of the GOR may be slightly more powerful in the tri-allelic case, particularly when susceptibility alleles are less common in the populations.