10 research outputs found
Comparative analyses of the complete genome sequences of Pierce's disease and citrus variegated chlorosis strains of Xylella fastidiosa
Xylella fastidiosa is a xylem-dwelling, insect-transmitted, gamma-proteobacterium that causes diseases in many plants, including grapevine, citrus, periwinkle, almond, oleander, and coffee. X. fastidiosa has an unusually broad host range, has an extensive geographical distribution throughout the American continent, and induces diverse disease phenotypes. Previous molecular analyses indicated three distinct groups of X.fastidiosa isolates that were expected to be genetically divergent. Here we report the genome sequence of X. fastidiosa (Temecula strain), isolated from a naturally infected grapevine with Pierce's disease (PD) in a wine-grape-growing region of California. Comparative analyses with a previously sequenced X.fastidiosa strain responsible for citrus variegated chlorosis (CVC) revealed that 98% of the PD X.fastidiosa Temecula genes are shared with the CVC X. fastidiosa strain 9a5c genes. Furthermore, the average amino acid identity of the open reading frames in the strains is 95.7%. Genomic differences are limited to phage-associated chromosomal rearrangements and deletions that also account for the strain-specific genes present in each genome. Genomic islands, one in each genome, were identified, and their presence in other X.fastidiosa strains was analyzed. We conclude that these two organisms have identical metabolic functions and are likely to use a common set of genes in plant colonization and pathogenesis, permitting convergence of functional genomic strategies.18531018102
Do transport costs have a differential effect on trade at the sectoral level?
This article aims to analyse the determinants of transport costs and to investigate their influence in international trade with a sample of disaggregate trade data. First, we estimate a transport-cost function using cross-section data on maritime and overland transport for four sectors: agro-industry, ceramic tiles, motor vehicle parts and accessories, and electrical and mechanical household appliances, obtained from interviews held with Spanish exporters and logistics operators in 2001. Second, we study the relationship between transport costs and trade and estimate the elasticity of trade with respect to transport costs for each sector. Important differences for high value- and low value-added sectors are observed. The trade-equation estimation shows that higher transport costs significantly deter trade, especially in high value-added sectors.
Diagnosis of, surgical technique for and treatment results from medullary lipomas associated with spinal dysraphism: experience with 38 patients
OBJECTIVE: To observe whether microsurgical removal of medullary lipomas and untethering of the medulla is a safe and efficient procedure. METHOD: A retrospective study was carried out on 38 patients with medullary lipomas associated with spinal dysraphism who underwent operations between January 1986 and January 2008, at the Neurosurgery Department of the Federal Hospital for State Public Servants, in Rio de Janeiro. RESULTS: No deaths occurred in this series, and there was no worsening of motor or bladder function among the patients. Seven individuals presented improvements in their motor deficit. Nine patients presented improvements in bladder function. Three individuals with trophic lesions achieved wound healing. CONCLUSION: Microsurgical removal of medullary lipomas associated with spinal dysraphism proved to be a safe procedure without deaths and with a low morbidity rate, and several patients achieved improvements in their neurological symptoms
Massively parallel sequencing for early molecular diagnosis in Leber congenital amaurosis
Purpose: Leber congenital amaurosis (LCA) is a rare congenital retinal dystrophy associated with 16 genes. Recent breakthroughs in LCA gene therapy offer the first prospect of treating inherited blindness, which requires an unequivocal and early molecular diagnosis. While present genetic tests do not address this due to a tremendous genetic heterogeneity, massively parallel sequencing (MPS) strategies might bring a solution. Here, we developed a comprehensive molecular test for LCA based on targeted MPS of all exons of 16 known LCA genes.
Methods: We designed a unique and flexible workflow for targeted resequencing of all 236 exons from 16 LCA genes based on quantitative PCR (qPCR) amplicon ligation, shearing, and parallel sequencing of multiple patients on a single lane of a short-read sequencer. Twenty-two prescreened LCA patients were included, five of whom had a known molecular cause.
Results: Validation of 107 variations was performed as proof of concept. In addition, the causal genetic defect and a single heterozygous mutation were identified in 3 and 5, respectively, of 17 patients without previously identified mutations.
Conclusion: We propose a novel targeted MPS-based approach that is suitable for accurate, fast, and cost-effective early molecular testing in LCA, and easily applicable in other genetic disorders
Massively parallel sequencing for early molecular diagnosis in Leber congenital amaurosis
Acute effects of 17β-estradiol and genistein on insulin sensitivity and spatial memory in aged ovariectomized female rats
Aging is characterized by decline in metabolic function and insulin resistance, and both seem to be in the basis of neurodegenerative diseases and cognitive dysfunction. Estrogens prevent age-related changes, and phytoestrogens influence learning and memory. Our hypothesis was that estradiol and genistein, using rapid-action mechanisms, are able to modify insulin sensitivity, process of learning, and spatial memory. Young and aged ovariectomized rats received acute treatment with estradiol or genistein. Aged animals were more insulin-resistant than young. In each age, estradiol and genistein-treated animals were less insulin-resistant than the others, except in the case of young animals treated with high doses of genistein. In aged rats, no differences between groups were found in spatial memory test, showing a poor performance in the water maze task. However, young females treated with estradiol or high doses of genistein performed well in spatial memory task like the control group. Only rats treated with high doses of genistein showed an optimal spatial memory similar to the control group. Conversely, acute treatment with high doses of phytoestrogens improved spatial memory consolidation only in young rats, supporting the critical period hypothesis for the beneficial effects of estrogens on memory. Therefore, genistein treatment seems to be suitable treatment in aged rats in order to prevent insulin resistance but not memory decline associated with aging. Acute genistein treatment is not effective to restore insulin resistance associated to the early loss of ovarian function, although it can be useful to improve memory deficits in this condition