A putative role for homocysteine in the pathophysiology of acute bacterial meningitis in children

Submitted by Nuzia Santos ([email protected]) on 2015-04-30T16:43:26Z No. of bitstreams: 1 2014_198.pdf: 159307 bytes, checksum: fd184d5598daf80e1d8ade4e11ecd865 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-04-30T16:51:38Z (GMT) No. of bitstreams: 1 2014_198.pdf: 159307 bytes, checksum: fd184d5598daf80e1d8ade4e11ecd865 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-04-30T16:55:38Z (GMT) No. of bitstreams: 1 2014_198.pdf: 159307 bytes, checksum: fd184d5598daf80e1d8ade4e11ecd865 (MD5)Made available in DSpace on 2015-04-30T16:55:38Z (GMT). No. of bitstreams: 1 2014_198.pdf: 159307 bytes, checksum: fd184d5598daf80e1d8ade4e11ecd865 (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Belo Horizonte, MG, Brazil.Universidade Federal de São Paulo. Departamento de Fisiobiologia. São Paulo, SP, Brazil.Fundação Hospitalar de Minas Gerais. Hospital Infantil João Paulo II. Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo. Departamento de Fisiobiologia. São Paulo, SP, Brazil.Background: Acute bacterial meningitis frequently causes cortical and hippocampal neuron loss leading to permanent neurological sequelae. Neuron death in acute bacterial meningitis involves the excessive activation of NMDA receptors and p53-mediated apoptosis, and the latter is triggered by the depletion of NAD + and ATP cellular stores by the DNA repair enzyme poly(ADP-ribose) polymerase. This enzyme is activated during acute bacterial meningitis in response to DNA damage induced, on its turn, by reactive oxygen and nitrogen species. An excess of homocysteine can also induce this cascade of events in hippocampal neurons. The present work aimed at investigating the possible involvement of homocysteine in the pathophysiology of meningitis by comparing its concentrations in cerebrospinal fluid (CSF) samples from children with viral or acute bacterial meningitis, and control individuals. Methods: Homocysteine and cysteine concentrations were assessed by high-performance liquid chromatography in CSF samples from nine patients with acute bacterial meningitis, 13 patients with viral meningitis and 18 controls (median age: 4 years-old; range: <1 to 13) collected by lumbar puncture at admission at the Children's Hospital Joao Paulo II - FHEMIG, from January 2010 to November 2011. Results: We found that homocysteine accumulates up to neurotoxic levels within the central nervous system of patients with acute bacterial meningitis, but not in those with viral meningitis or control individuals. No correlation was found between homocysteine and cysteine concentrations and the cerebrospinal fluid standard cytochemical parameters. Conclusions: Our results suggest that HCY is produced intrathecally in response to acute bacterial meningitis and accumulates within the central nervous system reaching potentially neurotoxic levels. This is the first work to propose a role for HCY in the pathophysiology of brain damage associated with acute bacterial meningitis

Assessing the efficiency of multiple sequence alignment programs.

Submitted by Nuzia Santos ([email protected]) on 2015-02-04T12:24:24Z No. of bitstreams: 1 2014_035.pdf: 516742 bytes, checksum: 2fa775121df1fd4b23c2255d7c7684fc (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-02-04T12:24:34Z (GMT) No. of bitstreams: 1 2014_035.pdf: 516742 bytes, checksum: 2fa775121df1fd4b23c2255d7c7684fc (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-02-04T12:30:02Z (GMT) No. of bitstreams: 1 2014_035.pdf: 516742 bytes, checksum: 2fa775121df1fd4b23c2255d7c7684fc (MD5)Made available in DSpace on 2015-02-04T12:30:02Z (GMT). No. of bitstreams: 1 2014_035.pdf: 516742 bytes, checksum: 2fa775121df1fd4b23c2255d7c7684fc (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Centro de Excelência em Bioinformática. Belo Horizonte, MG, Brazil/Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou Grupo de Genômica Biologia Computacional. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Centro de Excelência em Bioinformática. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Centro de Excelência em Bioinformática. Belo Horizonte, MG, Brazil/Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou Grupo de Genômica Biologia Computacional. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Centro de Excelência em Bioinformática. Belo Horizonte, MG, Brazil/Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou Grupo de Genômica Biologia Computacional. Belo Horizonte, MG, BrazilBACKGROUND: Multiple sequence alignment (MSA) is an extremely useful tool for molecular and evolutionary biology and there are several programs and algorithms available for this purpose. Although previous studies have compared the alignment accuracy of different MSA programs, their computational time and memory usage have not been systematically evaluated. Given the unprecedented amount of data produced by next generation deep sequencing platforms, and increasing demand for large-scale data analysis, it is imperative to optimize the application of software. Therefore, a balance between alignment accuracy and computational cost has become a critical indicator of the most suitable MSA program. We compared both accuracy and cost of nine popular MSA programs, namely CLUSTALW, CLUSTAL OMEGA, DIALIGN-TX, MAFFT, MUSCLE, POA, Probalign, Probcons and T-Coffee, against the benchmark alignment dataset BAliBASE and discuss the relevance of some implementations embedded in each program's algorithm. Accuracy of alignment was calculated with the two standard scoring functions provided by BAliBASE, the sum-of-pairs and total-column scores, and computational costs were determined by collecting peak memory usage and time of execution. RESULTS: Our results indicate that mostly the consistency-based programs Probcons, T-Coffee, Probalign and MAFFT outperformed the other programs in accuracy. Whenever sequences with large N/C terminal extensions were present in the BAliBASE suite, Probalign, MAFFT and also CLUSTAL OMEGA outperformed Probcons and T-Coffee. The drawback of these programs is that they are more memory-greedy and slower than POA, CLUSTALW, DIALIGN-TX, and MUSCLE. CLUSTALW and MUSCLE were the fastest programs, being CLUSTALW the least RAM memory demanding program. CONCLUSIONS: Based on the results presented herein, all four programs Probcons, T-Coffee, Probalign and MAFFT are well recommended for better accuracy of multiple sequence alignments. T-Coffee and recent versions of MAFFT can deliver faster and reliable alignments, which are specially suited for larger datasets than those encountered in the BAliBASE suite, if multi-core computers are available. In fact, parallelization of alignme

Comparative proteomics of cerebrospinal fluid reveals a predictive model for differential diagnosis of pneumococcal, meningococcal, and enteroviral meningitis, and novel putative therapeutic targets

Submitted by sandra infurna ([email protected]) on 2016-03-10T14:47:14Z No. of bitstreams: 1 alex_chapeaurouge_etal_IOC_2015.pdf: 343462 bytes, checksum: deaf5a5bf883dc052b8cdda7882ad5b1 (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-03-10T15:07:20Z (GMT) No. of bitstreams: 1 alex_chapeaurouge_etal_IOC_2015.pdf: 343462 bytes, checksum: deaf5a5bf883dc052b8cdda7882ad5b1 (MD5)Made available in DSpace on 2016-03-10T15:07:20Z (GMT). No. of bitstreams: 1 alex_chapeaurouge_etal_IOC_2015.pdf: 343462 bytes, checksum: deaf5a5bf883dc052b8cdda7882ad5b1 (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou (CPqRR). Grupo de Pesquisa em Genômica e Biologia Computacional. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou (CPqRR). Grupo de Pesquisa em Genômica e Biologia Computacional. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Toxinologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou (CPqRR). Grupo de Pesquisa em Genômica e Biologia Computacional. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Toxinologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou (CPqRR). Grupo de Pesquisa em Genômica e Biologia Computacional. Belo Horizonte, MG, Brasil.FHEMIG. Hospital de Crianças João Paulo II. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou (CPqRR). Grupo de Pesquisa Informática de Biosistemas. Belo Horizonte, MG, Brasil.Background: Meningitis is the inflammation of the meninges in response to infection or chemical agents. While aseptic meningitis, most frequently caused by enteroviruses, is usually benign with a self-limiting course, bacterial meningitis remains associated with high morbidity and mortality rates, despite advances in antimicrobial therapy and intensive care. Fast and accurate differential diagnosis is crucial for assertive choice of the appropriate therapeutic approach for each form of meningitis. Methods: We used 2D-PAGE and mass spectrometry to identify the cerebrospinal fluid proteome specifically related to the host response to pneumococcal, meningococcal, and enteroviral meningitis. The disease-specific proteome signatures were inspected by pathway analysis. Results: Unique cerebrospinal fluid proteome signatures were found to the three aetiological forms of meningitis investigated, and a qualitative predictive model with four protein markers was developed for the differential diagnosis of these diseases. Nevertheless, pathway analysis of the disease-specific proteomes unveiled that Kallikrein-kinin system may play a crucial role in the pathophysiological mechanisms leading to brain damage in bacterial meningitis. Proteins taking part in this cellular process are proposed as putative targets to novel adjunctive therapies. Conclusions: Comparative proteomics of cerebrospinal fluid disclosed candidate biomarkers, which were combined in a qualitative and sequential predictive model with potential to improve the differential diagnosis of pneumococcal, meningococcal and enteroviral meningitis. Moreover, we present the first evidence of the possible implication of Kallikrein-kinin system in the pathophysiology of bacterial meningitis

Revisitingmolecular serotyping of Streptococcus pneumonia

Submitted by Nuzia Santos ([email protected]) on 2016-07-06T11:40:35Z No. of bitstreams: 1 ve_Dhian_Camargo_ Revisitingmolecular_CPqRR_2015.pdf: 1647355 bytes, checksum: d446af4ae8ae1cdd1b0e0853582ff5ec (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-07-06T11:43:26Z (GMT) No. of bitstreams: 1 ve_Dhian_Camargo_ Revisitingmolecular_CPqRR_2015.pdf: 1647355 bytes, checksum: d446af4ae8ae1cdd1b0e0853582ff5ec (MD5)Made available in DSpace on 2016-07-06T11:43:26Z (GMT). No. of bitstreams: 1 ve_Dhian_Camargo_ Revisitingmolecular_CPqRR_2015.pdf: 1647355 bytes, checksum: d446af4ae8ae1cdd1b0e0853582ff5ec (MD5) Previous issue date: 2015Made available in DSpace on 2016-07-14T19:10:31Z (GMT). No. of bitstreams: 3 ve_Dhian_Camargo_ Revisitingmolecular_CPqRR_2015.pdf.txt: 41150 bytes, checksum: 677ee69411513ac8a87f484354a4dac8 (MD5) ve_Dhian_Camargo_ Revisitingmolecular_CPqRR_2015.pdf: 1647355 bytes, checksum: d446af4ae8ae1cdd1b0e0853582ff5ec (MD5) license.txt: 2991 bytes, checksum: 5a560609d32a3863062d77ff32785d58 (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Belo Horizonte, MG, Brasil / Fundação Ezequiel Dias. Serviço de Bactérias e Doenças de Fungos. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Grupo de Biologia e Genômica Computacional. Belo Horizonte, MG, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Centro de Excelência em Bioinformática. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Grupo de Biologia e Genômica Computacional. Belo Horizonte, MG, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Centro de Excelência em Bioinformática. Belo Horizonte, MG, Brasil.Fundação Ezequiel Dias. Serviço de Bactérias e Doenças de Fungos. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Belo Horizonte, MG, Brasil.Background: Ninety-two Streptococcus pneumoniae serotypes have been described so far, but the pneumococcal conjugate vaccine introduced in the Brazilian basic vaccination schedule in 2010 covers only the ten most prevalent in the country. Pneumococcal serotype-shifting after massive immunization is a major concern and monitoring this phenomenon requires efficient and accessible serotyping methods. Pneumococcal serotyping based on antisera produced in animals is laborious and restricted to a few reference laboratories. Alternatively, molecular serotyping methods assess polymorphisms in the cps gene cluster, which encodes key enzymes for capsular polysaccharides synthesis in pneumococci. In one such approach, cps-RFLP, the PCR amplified cps loci are digested with an endonuclease, generating serotype-specific fingerprints on agarose gel electrophoresis. Methods: In this work, in silico and in vitro approaches were combined to demonstrate that XhoII is the most discriminating endonuclease for cps-RFLP, and to build a database of serotype-specific fingerprints that accommodates the genetic diversity within the cps locus of 92 known pneumococci serotypes. Results: The expected specificity of cps-RFLP using XhoII was 76% for serotyping and 100% for serogrouping. The database of cps-RFLP fingerprints was integrated to Molecular Serotyping Tool (MST), a previously published web-based software for molecular serotyping. In addition, 43 isolates representing 29 serotypes prevalent in the state of Minas Gerais, Brazil, from 2007 to 2013, were examined in vitro; 11 serotypes (nine serogroups) matched the respective in silico patterns calculated for reference strains. The remaining experimental patterns, despite their resemblance to their expected in silico patterns, did not reach the threshold of similarity score to be considered a match and were then added to the database. Conclusion: The cps-RFLP method with XhoII outperformed the antisera-based and other molecular serotyping methods in regard of the expected specificity. In order to accommodate the genetic variability of the pneumococci cps loci, the database of cps-RFLP patterns will be progressively expanded to include new variant in vitro patterns. The cps-RFLP method with endonuclease XhoII coupled with MST for computer-assisted interpretation of results may represent a relevant contribution to the real time detection of changes in regional pneumococci population diversity in response to mass immunization programs

Resveratrol acts anti-inflammatory and neuroprotective in an infant rat model of pneumococcal meningitis by modulating the hippocampal miRNome.

Resveratrol (RSV) is anti-inflammatory and neuroprotective, cross the blood?brain barrier (BBB) and has a safe profile. Besides, RSV modulates the expression of some miRNAs related to neurological disorders. Thus, we hypothesized that RSV can be neuroprotective in pneumococcal meningitis by modulating the global microRNA expression profile (miRNome). Eleven-day old rats were intracysternally infected with S. pneumoniae (~?2???106 c.f.u.) and were orally administered with RSV (50 mg/kg) or vehicle in pre-treatment (before infection) or post-treatment schedules (3 and 18 h p.i.). At 24 h p.i., animals were euthanized and apoptotic cells were counted in the hippocampal dentate gyrus of the right brain hemispheres. The hippocampi from left hemispheres were used for cytokines and chemokines multiplex assay and miRNome profiling with TaqMan OpenArray Rodent MicroRNA. Infected rats treated with RSV had lower apoptotic scores and IL-1?, CCL2, and CCL3 levels when compared to the infected group receiving placebo. Seven miRNAs were down regulated, and 18 were up regulated by pneumococcal acute meningitis. Thirty-seven miRNAs were down regulated, and three were up regulated (hsa-miR-15b-5p, hsa-miR-25-3p, hsa-miR-125b-5p) by the interaction between meningitis and RSV. Pathway enriched analysis revealed that meningitis and RSV modulate the expression of miRNAs targeting critical pathways related to the pathophysiology of bacterial meningitis. Nevertheless, hsa-miR-25-3p and hsa-miR-125b-5p target the transcription factor TEF-1, for which there are binding sites in Il-1?, Ccl2, and Ccl3 genes. RSV is anti-inflammatory and neuroprotective in an infant rat model of pneumococcal meningitis and these positive effects involve the modulation of the hippocampal miRNome

Meningitis Associated with Simultaneous Infection by Multiple Dengue Virus Serotypes in Children, Brazil

To determine the causes of viral meningitis, we analyzed 22 cerebrospinal fluid samples collected during the 2014–2015 dengue epidemics in Brazil. We identified 3 serotypes of dengue virus (DENV-1, -2, and -3), as well as co-infection with 2 or 3 serotypes. We also detected the Asian II genotype of DENV-2

Green extraction by aqueous two-phase systems of porcine pancreatic and snake venom phospholipase A 2

Phospholipases comprise a group of enzymes with applications in the thermal stability and emulsifying capacity of food formulations. In this work aqueous two-phase systems (ATPS) were used to extract phospholipase A2 (PLA2) from raw porcine pancreas and snake venom at 25 °C. PLA2 was partitioned into ATPS composed of inorganic salts, water and polyethylene glycol. We determined the partition coefficient, recovery factor, purification factor, enzyme activity and emulsifying activity for the enzyme extracted with the different ATPS tested. The highest partition coefficient (Kp = 81.7) and the highest theoretical recovery percentage of PLA2 in the top and bottom phases of the systems were obtained from the pancreas extract. The highest recovery percentage in the top phase was obtained in a system with PEG1500/Na2SO4/H2O. Pearson correlation analysis between the ATPS descriptor parameters and the recovery and partitioning parameters of PLA2 showed significant, albeit small, correlation between molar mass and PEG phase volume. Furthermore, Principal Component Analysis showed that the best system for PLA2 purification was with ATPS PEG1500/Na2SO4/H2O. In addition to preserving enzyme activity, the ATPS provided a high partition coefficient of PLA2 (81.67%) and can be considered a viable technique for pre-purification of PLA2

Molecular mechanism driving retroperitoneal adipocyte hypertrophy and hyperplasia in response to a high-sugar diet.

Scope: We have previously shown an increase in adipocyte size and lipid content in retroperitoneal white adipose tissue (rWAT) induced by an 8-week high-sugar diet (HSD). In this study, we assessed the effect of a HSD on the transcriptional activity of adipogenic genes in a timecourse study to provide insight regarding the genetic networks involved in the rWAT response to dietary sugar. Methods and results: Weaned male Wistar rats were fed a standard chow diet or HSD (68% carbohydrates) for 4, 8 or 12 weeks, and rWAT was removed for histopathology and PCR array (adipogenesis) analyses. The HSD induced adipocyte hypertrophy and hyperplasia in rWAT after 12 weeks of ingestion. Additionally, the HSD altered serum VLDL-cholesterol, triacylglycerol and glucometabolic parameters. Hierarchical clustering revealed HSD-induced changes in the expression patterns of the tested gene set. Pathway analysis, which used the enrichment analysis algorithm of the Thompson Reuters MetaCore platform, associated a cluster of differentially expressed genes with canonical pathways related to regulating adipocyte differentiation and proliferation (p-value < 10?7). Conclusion: HSD feeding post-weaning increased both the adipocyte size and number by simultaneously up-regulating pro-adipogenic signals (the PPAR pathway) and down-regulating anti-adipogenic signals (Wnt pathway) in young adults

Intestinal microbiota regulates tryptophan metabolism following oral infection with Toxoplasma gondii

The intestinal microbiota plays an important role in modulating host immune responses. Oral Toxop/asma gondii infection can promote intestinal inflam­mation in certain mice strains. The 1DO-AhR axis may control tryptophan (Trp) me­tabolism constituting an important immune regulatory mechanism in inflammatory settings. Aims: In the present study, we investigated the role of the intestinal microbiota on Trp metabolism during oral infection with T gondii. Methods and results: Mice were treated with antibiotics for four weeks and then infected with T gondii by gavage. Histopathology and immune responses were eval­uated 8 days after infection. We found that depletion of intestinal microbiota by antibiotics contributed to resistance against T gondii infection and led to reduced expression of AhR on dendritic and Treg cells. Mice depleted of Gram-negative bac­teria presented higher levels of systemic Trp, downregulation of AhR expression and increased resistance to infection whereas depletion of Gram-positive bacteria did not affect susceptibility or expression of AhR on immune cells. Conclusion: Our findings indicate that the intestinal microbiota can control Trp avail­ability and provide a link between the AhR pathway and host-microbiota interaction in acute infection with T gondii.Fil: Santos, Liliane M.. Universidade Federal de Minas Gerais; BrasilFil: Commodaro, Alessandra G.. Universidade de Sao Paulo; BrasilFil: Vasquez, Alicia R. R.. Universidade Federal de Minas Gerais; BrasilFil: Kohlhoff, Markus. Instituto Federal de Educacao Ciencia E Tecnologia Do Sul de Minas.; BrasilFil: de Paula Guerra, Daniel A.. Universidade Federal de Minas Gerais; BrasilFil: Coimbra, Roney S.. Universidade Federal de Minas Gerais; BrasilFil: Martins Filho, Olindo A.. Universidade Federal de Minas Gerais; BrasilFil: Teixeira Carvalho, Andrea. Universidade Federal de Minas Gerais; BrasilFil: Rizzo, Luiz V.. Instituto Israelita de Pesquisa E Ensino, São Paulo; BrasilFil: Vieira, Leda Q.. Universidade Federal de Minas Gerais; BrasilFil: Serra, Horacio Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentin