425 research outputs found

    The Effects of Dasatinib in Experimental Acute Respiratory Distress Syndrome Depend on Dose and Etiology

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    Background/Aims: Evidence suggests that tyrosine-kinase inhibitors may attenuate lung inflammation and fibrosis in experimental acute respiratory distress syndrome (ARDS). We hypothesized that dasatinib, a tyrosine-kinase inhibitor, might act differently depending on the ARDS etiology and the dose. Methods: C57/BL6 mice were divided to be pre-treated with dasatinib (1mg/kg or 10mg/kg) or vehicle (1% dimethyl-sulfoxide) by oral gavage. Thirty-minutes after pre-treatment, mice were subdivided into control (C) or ARDS groups. ARDS animals received Escherichia coli lipopolysaccharide intratracheally (ARDSp) or intraperitoneally (ARDSexp). A new dose of dasatinib or vehicle was administered at 6 and 24h. Results: Forty-eight hours after ARDS induction, dasatinib 1mg/kg yielded: improved lung morphofunction and reduced cells expressing toll-like receptor (TLR)-4 in lung, independent of ARDS etiology; reduced neutrophil and levels of interleukin (IL)-6, IL-10 and transforming growth factor (TGF)-β in ARDSp. The higher dose of dasatinib caused no changes in lung mechanics, diffuse alveolar damage, neutrophil, or cells expressing TLR4, but increased IL-6, vascular endothelial growth factor (VEGF), and cells expressing Fas receptor in lung in ARDSp. In ARDSexp, it improved lung morphofunction, increased VEGF, and reduced cells expressing TLR4. Conclusion: Dasatinib may have therapeutic potential in ARDS independent of etiology, but careful dose monitoring is required. © 2015 S. Karger AG, Basel

    Benznidazole biotransformation and multiple targets in <i>Trypanosoma</i> cruzi revealed by metabolomics

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    &lt;b&gt;Background&lt;/b&gt;&lt;p&gt;&lt;/p&gt; The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn). Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methodology/Principal findings&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, γ-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions/significance&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi

    INTEnsive care bundle with blood pressure reduction in acute cerebral hemorrhage trial (INTERACT3): study protocol for a pragmatic stepped-wedge cluster-randomized controlled trial

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    Background: Early intensive blood pressure (BP) lowering remains the most promising treatment for acute intracerebral hemorrhage (ICH), despite discordant results between clinical trials and potential variation in the treatment effects by approach to control BP. As the third in a series of clinical trials on this topic, the INTEnsive care bundle with blood pressure Reduction in Acute Cerebral hemorrhage Trial (INTERACT3) aims to determine the effectiveness of a goal-directed care bundle protocol of early physiological control (intensive BP lowering, glycemic control, and pyrexia treatment) and reversal of anticoagulation, in acute ICH. Methods: INTERACT3 is a pragmatic, international, multicenter, stepped-wedge (4 phases/3 steps), cluster-randomized controlled trial to determine the effectiveness of a multifaceted care package in adult (age ≥ 18 years) patients (target 8360) with acute ICH (< 6 h of onset) recruited from 110 hospitals (average of 19 consecutive patients per phase) in low- and middle-income countries. After a control phase, each hospital implements the intervention (intensive BP lowering, target systolic < 140 mmHg; glucose control, target 6.1–7.8 mmol/L and 7.8–10.0 mmol/L in those without and with diabetes mellitus, respectively; anti-pyrexia treatment to target body temperature ≤ 37.5 °C; and reversal of anticoagulation, target international normalized ratio < 1.5 within 1 h). Information will be obtained on demographic and baseline clinical characteristics, in-hospital management, and 7-day outcomes. Central trained blinded assessors will conduct telephone interviews to assess physical function and health-related quality of life at 6 months. The primary outcome is the modified Rankin scale (mRS) at 6 months analyzed using ordinal logistic regression. The sample size of 8360 subjects provides 90% power (α = 0.05) to detect a 5.6% absolute improvement (shift) in the primary outcome of the intervention versus control standard care, with various assumptions. Discussion: As the largest clinical trial in acute ICH, INTERACT3 is on schedule to provide an assessment of the effectiveness of a widely applicable goal-directed care bundle for a serious condition in which a clearly proven treatment has yet to be established. Trial registration: ClinicalTrials.gov NCT03209258. Registered on 1 July 2017. Chinese Trial Registry ChiCTR-IOC-17011787. Registered on 28 June 201

    Fauna used in popular medicine in Northeast Brazil

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    <p>Abstract</p> <p>Background</p> <p>Animal-based remedies constitute an integral part of Brazilian Traditional Medicine. Due to its long history, zootherapy has in fact become an integral part of folk medicine both in rural and urban areas of the country. In this paper we summarize current knowledge on zootherapeutic practices in Northeast of Brazil, based on information compiled from ethnobiological scientific literature.</p> <p>Methods</p> <p>In order to examine the diversity of animals used in traditional medicine in Northeast of Brazil, all available references or reports of folk remedies based on animals sources were examined. 34 sources were analyzed. Only taxa that could be identified to species level were included in assessment of medicinal animal species. Scientific names provided in publications were updated.</p> <p>Results</p> <p>The review revealed that at least 250 animal species (178 vertebrates and 72 invertebrates) are used for medicinal purposes in Northeast of Brazil. The inventoried species comprise 10 taxonomic categories and belong to 141 Families. The groups with the greatest number of species were fishes (n = 58), mammals (n = 47) and reptiles (n = 37). The zootherapeutical products are used for the treatment of different illnesses. The most widely treated condition were asthma, rheumatism and sore throat, conditions, which had a wide variety of animals to treat them with. Many animals were used for the treatment of multiple ailments. Beyond the use for treating human diseases, zootherapeutical resources are also used in ethnoveterinary medicine</p> <p>Conclusion</p> <p>The number of medicinal species catalogued was quite expressive and demonstrate the importance of zootherapy as alternative therapeutic in Northeast of Brazil. Although widely diffused throughout Brazil, zootherapeutic practices remain virtually unstudied. There is an urgent need to examine the ecological, cultural, social, and public health implications associated with fauna usage, including a full inventory of the animal species used for medicinal purposes and the socio-cultural context associated with their consumption.</p

    T-Cell Memory Responses Elicited by Yellow Fever Vaccine are Targeted to Overlapping Epitopes Containing Multiple HLA-I and -II Binding Motifs

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    The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4+ and CD8+ T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines. © 2013 de Melo et al

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
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