70 research outputs found

    The relBE2Spn Toxin-Antitoxin System of Streptococcus pneumoniae: Role in Antibiotic Tolerance and Functional Conservation in Clinical Isolates

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    Type II (proteic) chromosomal toxin-antitoxin systems (TAS) are widespread in Bacteria and Archaea but their precise function is known only for a limited number of them. Out of the many TAS described, the relBE family is one of the most abundant, being present in the three first sequenced strains of Streptococcus pneumoniae (D39, TIGR4 and R6). To address the function of the pneumococcal relBE2Spn TAS in the bacterial physiology, we have compared the response of the R6-relBE2Spn wild type strain with that of an isogenic derivative, ΔrelB2Spn under different stress conditions such as carbon and amino acid starvation and antibiotic exposure. Differences on viability between the wild type and mutant strains were found only when treatment directly impaired protein synthesis. As a criterion for the permanence of this locus in a variety of clinical strains, we checked whether the relBE2Spn locus was conserved in around 100 pneumococcal strains, including clinical isolates and strains with known genomes. All strains, although having various types of polymorphisms at the vicinity of the TA region, contained a functional relBE2Spn locus and the type of its structure correlated with the multilocus sequence type. Functionality of this TAS was maintained even in cases where severe rearrangements around the relBE2Spn region were found. We conclude that even though the relBE2Spn TAS is not essential for pneumococcus, it may provide additional advantages to the bacteria for colonization and/or infection

    Suppression and Regression of Choroidal Neovascularization in Mice by a Novel CCR2 Antagonist, INCB3344

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    PURPOSE: To investigate the effect of an intravitreally administered CCR2 antagonist, INCB3344, on a mouse model of choroidal neovascularization (CNV). METHODS: CNV was induced by laser photocoagulation on Day 0 in wild type mice. INCB3344 or vehicle was administered intravitreally immediately after laser application. On Day 14, CNV areas were measured on retinal pigment epithelium (RPE)-choroid flat mounts and histopathologic examination was performed on 7 µm-thick sections. Macrophage infiltration was evaluated by immunohistochemistry on RPE-choroid flat mounts and quantified by flow cytometry on Day 3. Expression of vascular endothelial growth factor (VEGF) protein in RPE-choroid tissue was examined by immunohistochemistry and ELISA, VEGF mRNA in sorted macrophages in RPE-choroid tissue was examine by real-time PCR and expression of phosphorylated extracellular signal-regulated kinase (p-ERK 1/2) in RPE-choroid tissue was measured by Western blot analysis on Day 3. We also evaluated the efficacy of intravitreal INCB3344 to spontaneous CNV detected in Cu, Zn-superoxide dismutase (SOD1) deficient mice. Changes in CNV size were assessed between pre- and 1week post-INCB3344 or vehicle administration in fundus photography and fluorescence angiography (FA). RESULTS: The mean CNV area in INCB3344-treated mice decreased by 42.4% compared with the vehicle-treated control mice (p<0.001). INCB3344 treatment significantly inhibited macrophage infiltration into the laser-irradiated area (p<0.001), and suppressed the expression of VEGF protein (p = 0.012), VEGF mRNA in infiltrating macrophages (p<0.001) and the phosphorylation of ERK1/2 (p<0.001). The area of spontaneous CNV in Sod1⁻/⁻ mice regressed by 70.35% in INCB3344-treated animals while no change was detected in vehicle-treated control mice (p<0.001). CONCLUSIONS: INCB3344 both inhibits newly forming CNV and regresses established CNV. Controlling inflammation by suppressing macrophage infiltration and angiogenic ability via the CCR-2/MCP-1 signal may be a useful therapeutic strategy for treating CNV associated with age-related macular degeneration

    Polymorphisms in regulatory regions of Cyclooxygenase-2 gene and breast cancer risk in Brazilians: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>Cyclooxygenase-2 (COX-2) is up-regulated in several types of cancer, and it is hypothesized that COX-2 expression may be genetically influenced. Here, we evaluate the association between single-nucleotide polymorphisms (SNPs) in the COX-2 gene (<it>PTGS2</it>) and the occurrence of breast cancer among Brazilian women.</p> <p>Methods</p> <p>The study was conducted prospectively in two steps: First, we screened the promoter region and three fragments of the 3'-untranslated region of <it>PTGS2 </it>from 67 healthy Brazilians to identify SNPs and to select those with a minor allele frequency (MAF) of at least 0.10. The MAF of these selected SNPs was further characterized in 402 healthy volunteers to evaluate potential differences related to heterogeneous racial admixture and to estimate the existence of linkage disequilibrium among the SNPs. The second step was a case-control study with 318 patients and 273 controls designed to evaluate <it>PTGS2 </it>genotype- or haplotype-associated risk of breast cancer.</p> <p>Results</p> <p>The screening analysis indicated nine SNPs with the following MAFs: rs689465 (0.22), rs689466 (0.15), rs20415 (0.007), rs20417 (0.32), rs20419 (0.015), rs5270 (0.02), rs20424 (0.007), rs5275 (0.22) and rs4648298 (0.01). The SNPs rs689465, rs689466, rs20417 and rs5275 were further studied: Their genotypic distributions followed Hardy-Weinberg equilibrium and the MAFs were not affected by gender or skin color. Strong linkage disequilibrium was detected for rs689465, rs20417 and rs5275 in the three possible pairwise combinations. In the case-control study, there was a significant increase of rs5275TC heterozygotes in cases compared to controls (OR = 1.44, 95% CI = 1.01-2.06; P = 0.043), and the haplotype formed by rs689465G, rs689466A, rs20417G and rs5275C was only detected in cases. The apparent association with breast cancer was not confirmed for rs5275CC homozygotes or for the most frequent rs5275C-containing haplotypes.</p> <p>Conclusions</p> <p>Our results indicate no strong association between the four most frequent <it>PTGS2 </it>SNPs and the risk of breast cancer.</p

    Markers of neurodevelopmental impairments in&nbsp;early-onset psychosis

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    Maria Giuseppina Petruzzelli,1 Lucia Margari,1 Francesco Craig,1 Maria Gloria Campa,1 Domenico Martinelli,2 Adriana Pastore,3 Marta Simone,1 Francesco Margari3 1Child and Adolescence Neuropsychiatry Unit, Department of&nbsp;Basic Medical Sciences, Neuroscience and Sense Organs, University &ldquo;Aldo Moro&rdquo; of Bari, 2Department of Medical and Surgical Sciences; University of Foggia, Foggia, 3Psychiatry Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organ, University &ldquo;Aldo Moro&rdquo; of&nbsp;Bari, Bari, Italy Background: The aim of this study was to assess the association between the clinical and neurobiological markers of neurodevelopmental impairments and early-onset schizophrenia spectrum psychosis. Methods: A sample of 36 patients with early-onset schizophrenia spectrum psychosis was compared to a control sample of 36 patients with migraine. We assessed early childhood neurodevelopmental milestones using a modified version of the General Developmental Scale, general intellectual ability using the Wechsler Intelligence Scale for Children&ndash;Revised or Leiter International Performance Scale&ndash;Revised for patients with speech and language abnormalities, and neurological soft signs with specific regard to subtle motor impairment. Results: Subjects with early-onset psychosis had a higher rate of impaired social development (P=0.001), learning difficulties (P=0.04), enuresis (P=0.0008), a lower intelligence quotient (P&lt;0.001), and subtle motor impairments (P=0.005) than control subjects. Conclusion: We suggest that neurodevelopment in early-onset psychosis is characterized by a global impairment of functional and adaptive skills that manifests from early childhood, rather than a delay or limitation in language and motor development. The current evidence is based on a small sample and should be investigated in larger samples in future research. Keywords: early-onset psychosis, early-onset schizophrenia, neurodevelopment, social cognition, intellectual disabilitie

    Cerebral venous thrombosis after lumbar puncture and intravenous high dose corticosteroids: A case report of a childhood multiple sclerosis.

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    The association between cerebral venous thrombosis (CVT) and multiple sclerosis (MS) has already been reported in several adult patients with clinically definite MS, in a suspected relation to i.v. corticosteroids or previously performed lumbar puncture (LP). We are reporting a case, which is, to our knowledge, the first one concerning a child patient with a MS, who developed multiple CVT after LP and during high-dose i.v. corticosteroid. Our conclusions are that the sequence LP followed by high dose corticosteroids may be a contributory factor for the development of CVT when associated with other risk factors

    A common mutation in the insulin receptor substrate-1 gene is a genetic marker for the insulin resistance syndrome in patients with coronary artery disease

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    Insulin resistance is associated with increased risk of atherosclerosis. insulin receptor substrate-1 (IRS-I) plays a key role in tissue insulin sensitivity. A common mutation (G972R) of the IRS-1 gene has been shown to impair IRS-1 function, and it has been associated with reduced insulin sensitivity and lipid abnormalities. This led us to investigate the role of the G972R mutation in predisposing individuals to coronary artery disease (CAD). The DNA of 318 subjects with angiographically documented coronary atherosclerosis (>50% stenosis) and 208 population control subjects was analyzed for the presence of the G972R mutation. This mutation was detected by nested polymerase chain reaction and BstNI restriction enzyme digestion. The frequency of the G972R mutation was significantly higher among patients with CAD than controls (18.9% versus 6.8%, respectively; P<0.001). After controlling for other coronary risk factors, the relative risk of CAD associated with the G972R mutation was 2.93 (95% CI 1.30 to 6.60; P<0.02) in the entire cohort. This risk was found to be even higher in the subgroups of obese subjects (odds ratio [OR] 6.97, 95% CI 2.24 to 21.4; P<0.001) and subjects with clinical features of insulin resistance syndrome (OR 27.3, 95% CI 7.19 to 104.0; P<0.001). The IRS-1 gene variant was associated with a higher frequency of diabetes mellitus (14.9% among, carriers versus 6.5% among noncarriers; P<0.01) and with a 60% increase of plasma total triglycerides (P<0.001), Also, plasma concentrations of total cholesterol and the ratio of total cholesterol to HDL cholesterol were significantly (P<0.001) higher among carriers than noncarriers, although to lesser a extent, These effects were independent of CAD status. The G972R mutation in the IRS-1 gene was found to be a significant independent predictor of CAD. Moreover, this mutation greatly increased the risk of CAD in obese subjects and in patients with the cluster of abnormalities of insulin resistance syndrome. Besides the increased frequency of diabetes, carriers showed a more atherogenic lipid profile, suggesting a potential role of the IRS-1 gene in the pathogenesis of lipid abnormalities associated with CAD
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