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Mafra V.,Instituto Agronomico Of Campinas | Mafra V.,University of Campinas | Martins P.K.,Instituto Agronomico Of Campinas | Francisco C.S.,Instituto Agronomico Of Campinas | And 3 more authors.
BMC Genomics | Year: 2013

Background: Citrus huanglongbing (HLB) disease is caused by endogenous, phloem-restricted, Gram negative, uncultured bacteria named Candidatus Liberibacter africanus (CaLaf), Ca. L. asiaticus (CaLas), and Ca. L. americanus (CaLam), depending on the continent where the bacteria were first detected. The Asian citrus psyllid vector, Diaphorina citri, transmits CaLas and CaLam and both Liberibacter species are present in Brazil. Several studies of the transcriptional response of citrus plants manifesting HLB symptoms have been reported, but only for CaLas infection. This study evaluated the transcriptional reprogramming of a susceptible genotype of sweet orange challenged with CaLam, using a customized 385K microarray containing approximately 32,000 unigene transcripts. We analyzed global changes in gene expression of CaLam-infected leaves of sweet orange during the symptomatic stage of infection and compared the results with previously published microarray studies that used CaLas-infected plants. Twenty candidate genes were selected to validate the expression profiles in symptomatic and asymptomatic PCR-positive leaves infected with CaLas or CaLam.Results: The microarray analysis identified 633 differentially expressed genes during the symptomatic stage of CaLam infection. Among them, 418 (66%) were upregulated and 215 (34%) were down regulated. Five hundred and fourteen genes (81%) were orthologs of genes from Arabidopsis thaliana. Gene set enrichment analysis (GSEA) revealed that several of the transcripts encoded transporters associated with the endomembrane system, especially zinc transport. Among the most biologically relevant gene transcripts in GSEA were those related to signaling, metabolism and/or stimulus to hormones, genes responding to stress and pathogenesis, biosynthesis of secondary metabolites, oxidative stress and transcription factors belonging to different families. Real time PCR of 20 candidate genes validated the expression pattern of some genes in symptomatic and asymptomatic leaves infected with CaLam or CaLas.Conclusions: Many gene transcripts and biological processes are significantly altered upon CaLam infection. Some of them had been identified in response to CaLas infection, while others had not been previously reported. These data will be useful for selecting target genes for genetic engineering to control HLB. © 2013 Mafra et al.; licensee BioMed Central Ltd. Source


Liu A.,Bridge HIV | Liu A.,University of California at San Francisco | Glidden D.V.,University of California at San Francisco | Anderson P.L.,Aurora Pharmaceutical | And 17 more authors.
Journal of Acquired Immune Deficiency Syndromes | Year: 2014

Background: Adherence to pre-exposure prophylaxis (PrEP) is critical for efficacy. Antiretroviral concentrations are an objective measure of PrEP use and correlate with efficacy. Understanding patterns and correlates of drug detection can identify populations at risk for non-adherence and inform design of PrEP adherence interventions. Methods: Blood antiretroviral concentrations were assessed among active arm participants in iPrEx, a randomized placebo-controlled trial of emtricitabine/tenofovir in men who have sex with men and transgender women in 6 countries. We evaluated rates and correlates of drug detection among a random sample of 470 participants at week 8 and a longitudinal cohort of 303 participants through 72 weeks of follow-up. Results: Overall, 55% of participants (95% confidence interval: 49 to 60) tested at week 8 had drug detected. Drug detection was associated with older age and varied by study site. In longitudinal analysis, 31% never had drug detected, 30% always had drug detected, and 39% had an inconsistent pattern. Overall detection rates declined over time. Drug detection at some or all visits was associated with older age, indices of sexual risk, including condomless receptive anal sex, and responding "don't know" to a question about belief of PrEP efficacy (0-10 scale). Conclusions: Distinct patterns of study product use were identified, with a significant proportion demonstrating no drug detection at any visit. Research literacy may explain greater drug detection among populations having greater research experience, such as older men who have sex with men in the United States. Greater drug detection among those reporting highest risk sexual practices is expected to increase the impact and cost-effectiveness of PrEP. Copyright © 2014 by Lippincott Williams & Wilkins. Source


Xavier-Carvalho C.,Instituto Oswaldo Cruz | Gibson G.,Escola Nacional de Saude Publica ENSP | Brasil P.,Institute Pesquisa Clinica Evandro Chagas IPEC FIOCRUZ | Ferreira R.X.,Hospital Universitario Antonio Pedro | And 8 more authors.
Infection, Genetics and Evolution | Year: 2013

Dengue is an arthropod-borne emerging viral disease with high morbidity and mortality risk in tropical countries like Brazil. Clinical manifestations are vast, ranging from asymptomatic to most severe forms of dengue such as shock. Previous data have shown that host genetics play a role in disease susceptibility and severity. Herein, we have tested the association of single nucleotide polymorphisms (SNPs) at TNF, IL10, MIF, DCSIGN, CLEC5A, NOD2, CCR5 and MRC1 as candidate genes using a matched case-control study design including 88 severe children cases of dengue patients and 335 healthy unrelated subjects that was also separated in IgG+ and IgG- controls. We demonstrated that the TT genotype of CLEC5A SNP (rs1285933 C>T) is associated with dengue severity (OR=2.25; p=0.03) and that GG genotype of -336G>A DCSIGN (CD209) SNP is associated with protection to severe dengue (OR=0.12; p=0.04). Both comparisons were borderline significant when cases were compared with IgG+ controls subgroup. Nevertheless, genotype-phenotype correlation was also assessed using serum levels of TNF from infected patients at the onset of dengue fever, and CT/TT carriers in CLEC5A secreted higher levels of TNF than CC individuals in 5-7days of infection. No significant difference was observed in TNF levels between genotypes GG versus AG/AA at DCSIGN promoter. Next, we performed a meta-analysis retrieving results from the literature for -336G>A DCSIGN and -308G>A TNF SNPs demonstrating that the consensus estimates of these SNPs indicated no association with dengue severity (when compared to Dengue fever) in the overall analysis. But, a subgroup analysis in the -336G>A DCSIGN, the G allele was associated with severe dengue susceptibility in Asians (ORallele=2.77; p=0.0001; ORcarriers=2.99; p=0.0001) and protection in Brazilians (ORallele=0.66; p=0.013). In summary, our results suggest that genetic variations at CLEC5A increase the risk and regulate TNF secretion in dengue severity among Brazilians. Also, combined data of the literature suggest population-specific effect of the -336 DCSIGN SNP more prominent in Asians and in a different direction than Brazilians. © 2013 Elsevier B.V. Source


Heringer G.C.,Federal University of Minas Gerais | Oueghlani E.,Moorfields Eye Hospital | Dell'Omo R.,Moorfields Eye Hospital | Curi A.L.L.,Institute Pesquisa Clinica Evandro Chagas IPEC FIOCRUZ | And 2 more authors.
British Journal of Ophthalmology | Year: 2014

Background/aims: Toxoplasmic retinochoroiditis is the commonest known cause of posterior uveitis worldwide and reactivation is unpredictable. Based on results from one study, the authors proposed that antitoxoplasmic therapy should be initiated as prophylaxis for intraocular surgery in patients with toxoplasmic scars. The aim of this study is to analyse the risk of toxoplasmic retinochoroiditis reactivation following intraocular procedures. Methods: Retrospective analysis of the medical records of a total of 69 patients who underwent intraocular surgery and presented with toxoplasmic retinochoroiditis scars. Results: No patient received prophylactic antitoxoplasmic therapy. Reactivation following the surgical procedure occurred in four cases, with one at 3 months and the others respectively at 13, 14 and 17 months. Conclusions: Our study shows that intraocular surgery did not result in a significant reactivation rate of toxoplasmic retinochoroiditis in the absence of preoperative prophylactic antitoxoplasmic therapy. Source


Torres D.C.,Colecao Of Leishmania Do Instituto Oswaldo Cruz Ioc Fiocruz | Torres D.C.,Instituto Oswaldo Cruz IOC Fiocruz | Ribeiro-Alves M.,Institute Pesquisa Clinica Evandro Chagas IPEC FIOCRUZ | Romero G.A.S.,University of Brasilia | And 2 more authors.
Acta Tropica | Year: 2013

The great public health problem posed by leishmaniasis has substantially worsened in recent years by the emergence of clinical failure. In Brazil, the poor prognosis observed for patients infected by Leishmania braziliensis (Lb) or L. guyanensis (Lg) may be related to parasite drug resistance. In the present study, 19 Lb and 29 Lg isolates were obtained from infected patients with different treatment outcomes. Translated amino acid sequence polymorphisms from four described antimony resistance related genes (AQP1, hsp70, MRPA and TRYR) were tested as candidate markers for antimonial treatment failure prediction. Possibly due to the low intraspecific variability observed in Lg samples, none of the prediction models had good prognosis values. Most strikingly, one mutation (T579A) found in hsp70 of Lb samples could predict 75% of the antimonial treatment failure clinical cases. Moreover, a multiple logistic regression model showed that the change from adenine to guanine at position 1735 of the hsp70 gene, which is responsible for the T579A mutation, significantly increased the chance of Lb clinical isolates to be associated with treatment failure (OR = 7.29; CI 95% = [1.17, 45.25]; p=0.0331). The use of molecular markers to predict treatment outcome presents practical and economic advantages as it allows the development of rapid assays to monitor the emergence of drug resistant parasites that can be clinically applied to aid the prognosis of cutaneous leishmaniasis in Brazil. © 2013 Elsevier B.V. Source

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