172 research outputs found

    Indole modifies the central carbon flux in the anaerobic metabolism of Escherichia coli: application to the production of hydrogen and other metabolites.

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    Indole is a bicyclic signaling molecule with effects on both eukaryotic and prokaryotic cells. The majority of studies of indole action have been performed with bacteria cultured under aerobic conditions and little information is available about its effects under anaerobic conditions. Here the effect of the indole on anaerobic metabolism of Escherichia coli WDHL was studied. Indole in the range 0.5-8mM was added to the culture medium and cell growth, hydrogen and metabolite production were compared to cultures lacking indole. Results showed that while 8mM indole abolished growth completely, 4mM indole had a partial bacteriostatic effect and the maximum optical density of the culture decreased by 44% compared to the control cultures. In addition, 4mM indole had an important effect on anaerobic metabolism. Hydrogen production increased from 650±115 to 1137±343mL H2/L, and hydrogen yield increased from 0.45±0.1 to 0.94±0.34mol H2/mol glucose, compared to the control culture. Carbon flux was also affected and the composition of the final by-products changed. Lactate (41mM) was the main metabolite in the control cultures, whereas ethanol (56.2mM) and acetate (41.2mM) were the main metabolites in the cultures with 2mM indole. We conclude that the supplementation of E. coli cultures with exogenous indole is a simple and novel strategy to improve the production of hydrogen as well as other metabolites such as ethanol used as biofuels.Partial financial support from CONACyT Grant Pro Nal 247498, SENER-Cemie Bio249564, and CONACyT sabbatical fellowship 259644.This is the author accepted manuscript. The final version is available from Elsevier via https://doi.org/10.1016/j.nbt.2016.09.00

    Diseño de un dispositivo robótico bio-inspirado en una araña para la evaluación del dióxido de carbono indexado en el aire

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    Las arañas, en comparación con la mayoría de otros animales, tiene la habilidad para acceder a diferentes tipos de medio ambiente donde otros animales o incluso los humanos no pueden acceder. Estos atributos de las arañas se toman en este proyecto para el diseño y desarrollo de un robot araña cuadrúpedo en condiciones de poder moverse en todo tipo de direcciones y realizar el movimiento de ascender o descender. Este artículo presenta el modelo dinámico y cinemático con el propósito de entender como matemáticamente un animal cuadrúpedo y una araña caminan. En este caso nosotros estudiamos el movimiento de una araña real para así poder definir un modelo biomimético adecuado para nuestro robot. Igualmente, la simulación del movimiento fue implementada y los resultados son mostrados

    First visual occurrence data for deep-sea cnidarians in the South-western Colombian Caribbean

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    Attention to the deep-sea environment has increased dramatically in the last decade due to the rising interest in natural resource exploitation. Although Colombia holds a large submerged territory, knowledge of the seabed and its biodiversity beyond 1,000 m depth is very limited. During 2015–2017, Anadarko Colombia Company (ACC) carried out hydrocarbon exploratory activities in the South-western Colombian Caribbean, at depths between 375 m and 2,565 m. Capitalising on available data resources from these activities, several cnidarian species were observed in ROV and towed camera surveys. We analysed over nine hours of video and 5,066 still images from these surveys, identifying organisms to the lowest possible taxonomic level. The images and associated data presented here correspond to 108 observations of deep-sea cnidarians, including seven new records for the Colombian Caribbean. Given the paucity of research and funding to explore the deep-sea in Colombia, the present dataset comprises the largest deep-sea Cnidaria imagery inventory to date for the Colombian Caribbean

    Vomocytosis: Too Much Booze, Base, or Calcium?

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    Macrophages are well known for their phagocytic activity and their role in innate immune responses. Macrophages eat non-self particles, via a variety of mechanisms, and typically break down internalized cargo into small macromolecules. However, some pathogenic agents have the ability to evade this endosomal degradation through a nonlytic exocytosis process termed vomocytosis. This phenomenon has been most often studied for Cryptococcus neoformans, a yeast that causes roughly 180,000 deaths per year, primarily in immunocompromised (e.g., human immunodeficiency virus [HIV]) patients. Existing dogma purports that vomocytosis involves distinctive cellular pathways and intracellular physicochemical cues in the host cell during phagosomal maturation. Moreover, it has been observed that the immunological state of the individual and macrophage phenotype affect vomocytosis outcomes. Here we compile the current knowledge on the factors (with respect to the phagocytic cell) that promote vomocytosis of C. neoformans from macrophages

    Platelet Count in First Trimester of Pregnancy as a Predictor of Perinatal Outcome

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    AIM: To rule out maternal and pregnancy factors that may contribute to platelet count (PLT) changes in the first trimester of gestation and examine if there is any association between its levels and adverse perinatal outcome.METHODS: The study population included all patients from the first-trimester visit between 2013-2015 with pregnancy results. Linear multiple regression was constructed to rule out variables that may have a significant contribution to PLT. For each adverse outcome at birth, multiple logistic regression analysis was implemented to estimate the PLT effect.RESULTS: PLT was measured in 6092 patients. There was the significant contribution on PLT in the first trimester from maternal weight, the presence of rheumatologic disease, BHCG levels and MPV. There was a significant association between PLT and abnormal cardiotocography at delivery (OR 1.004; IC95% 1.001 to 1.007) and C-Section due to abnormal CTG (OR 1.005; IC95% 1.002 to 1.008). When adjusted for factors that interact with PLT there was also a significant association with pH at birth < 7.10 and gestational diabetes.CONCLUSIONS: Maternal and pregnancy factors can poorly predict relevant changes in PLT at the first trimester of gestation. PLT at first trimester of pregnancy might predict adverse perinatal outcome in combination with other markers

    Matrix metalloproteinase-9, -10, and tissue inhibitor of matrix metalloproteinases-1 blood levels as biomarkers of severity and mortality in sepsis

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    INTRODUCTION: Matrix metalloproteinases (MMPs) play a role in infectious diseases through extracellular matrix (ECM) degradation, which favors the migration of immune cells from the bloodstream to sites of inflammation. Although higher levels of MMP-9 and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) have been found in small series of patients with sepsis, MMP-10 levels have not been studied in this setting. The objective of this study was to determine the predictive value of MMP-9, MMP-10, and TIMP-1 on clinical severity and mortality in a large series of patients with severe sepsis. METHODS: This was a multicenter, observational, and prospective study carried out in six Spanish Intensive Care Units. We included 192 (125 surviving and 67 nonsurviving) patients with severe sepsis and 50 age- and sex-matched healthy controls in the study. Serum levels of MMP-9, MMP-10, TIMP-1, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-10 were measured in patients with severe sepsis at the time of diagnosis and in healthy controls. RESULTS: Sepsis patients had higher levels of MMP-10 and TIMP-1, higher MMP-10/TIMP-1 ratios, and lower MMP-9/TIMP-1 ratios than did healthy controls (P < 0.001). An association was found between MMP-9, MMP-10, TIMP-1, and MMP-9/TIMP-1 ratios and parameters of sepsis severity, assessed by the SOFA score, the APACHE-II score, lactic acid, platelet count, and markers of coagulopathy. Nonsurviving sepsis patients had lower levels of MMP-9 (P = 0.037), higher levels of TIMP-1 (P < 0.001), lower MMP-9/TIMP-1 ratio (P = 0.003), higher levels of IL-10 (P < 0.001), and lower TNF-alpha/IL-10 ratio than did surviving patients. An association was found between MMP-9, MMP-10, and TIMP-1 levels, and TNF-alpha and IL-10 levels. The risk of death in sepsis patients with TIMP-1 values greater than 531 ng/ml was 80% higher than that in patients with lower values (RR = 1.80; 95% CI = 1.13 to 2.87;P = 0.01; sensitivity = 0.73; specificity = 0.45). CONCLUSIONS: The novel findings of our study on patients with severe sepsis (to our knowledge, the largest series reporting data about MMP levels in sepsis) are that reduced MMP-9/TIMP-1 ratios and increased MMP-10 levels may be of great pathophysiologic significance in terms of severity and mortality, and that TIMP-1 levels may represent a biomarker to predict the clinical outcome of patients with sepsis

    Regional mitochondrial DNA and cell-type changes in post-mortem brains of non-diabetic Alzheimer’s disease are not present in diabetic Alzheimer’s disease

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    Background: Mitochondrial dysfunction is implicated in both diabetes and Alzheimer’s disease (AD), and diabetes also increases the risk of AD, however the combined impact of AD and diabetes on brain mitochondria is unknown. The purpose of this study was to test the hypothesis that the combination of both diabetes and AD exacerbates mitochondrial dysfunction. Methods: Post-mortem human brains (n=74), were used to determine mitochondrial DNA (mtDNA) content of cerebellum, frontal cortex and parietal cortex by quantifying absolute mtDNA copy number/cell using real time qPCR. mtDNA content was compared between diabetic and non-diabetic cases representing non-cognitively impaired controls (NCI), mildly cognitively impaired (MCI) and AD. A subset of parietal cortex samples was used to quantify mRNAs corresponding to cell types and mitochondrial function. Immune-staining of parietal cortex sections followed by semi-automated stereological assessment was performed to assess cell types. Results. Using mtDNA as an indicator of mitochondrial content, we observed significant regional variation, being highest in the parietal cortex, and lowest in the cerebellum. In the absence of diabetes, AD cases had decreased parietal cortex mtDNA, reduced MAP2 (neuronal) mRNA and increased GFAP (astrocyte) mRNA, relative to NCI. However, in the presence of both diabetes and AD, we did not observe these changes in the parietal cortex. Irrespective of cognitive status, all 3 brain regions in diabetic cases had significantly higher mtDNA than the non-diabetic cases. Conclusion. Our data show that the parietal cortex has the highest mitochondrial content but is also the most vulnerable to changes in AD, as shown by reduced mtDNA and neurones in this region. In contrast, when patients have both diabetes and AD, the AD associated parietal cortex changes are no longer seen, suggesting that the pathology observed in diabetic AD may be different to that seen in non-diabetic AD. The lack of clear functional changes in mitochondrial parameters in diabetic AD suggest that there may be different mechanisms contributing to cognitive impairment in diabetes and their impact on the respective disease neuro-pathologies remain to be fully understood

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Association between serum tissue inhibitor of matrix metalloproteinase-1 levels and mortality in patients with severe brain trauma injury

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    OBJECTIVE: Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play a role in neuroinflammation after brain trauma injury (TBI). Previous studies with small sample size have reported higher circulating MMP-2 and MMP-9 levels in patients with TBI, but no association between those levels and mortality. Thus, the aim of this study was to determine whether serum TIMP-1 and MMP-9 levels are associated with mortality in patients with severe TBI. METHODS: This was a multicenter, observational and prospective study carried out in six Spanish Intensive Care Units. Patients with severe TBI defined as Glasgow Coma Scale (GCS) lower than 9 were included, while those with Injury Severity Score (ISS) in non-cranial aspects higher than 9 were excluded. Serum levels of TIMP-1, MMP-9 and tumor necrosis factor (TNF)-alpha, and plasma levels of tissue factor (TF) and plasminogen activator inhibitor (PAI)-1 plasma were measured in 100 patients with severe TBI at admission. Endpoint was 30-day mortality. RESULTS: Non-surviving TBI patients (n = 27) showed higher serum TIMP-1 levels than survivor ones (n = 73). We did not find differences in MMP-9 serum levels. Logistic regression analysis showed that serum TIMP-1 levels were associated 30-day mortality (OR = 1.01; 95% CI = 1.001-1.013; P = 0.03). Survival analysis showed that patients with serum TIMP-1 higher than 220 ng/mL presented increased 30-day mortality than patients with lower levels (Chi-square = 5.50; P = 0.02). The area under the curve (AUC) for TIMP-1 as predictor of 30-day mortality was 0.73 (95% CI = 0.624-0.844; P<0.001). An association between TIMP-1 levels and APACHE-II score, TNF- alpha and TF was found. CONCLUSIONS: The most relevant and new findings of our study, the largest series reporting data on TIMP-1 and MMP-9 levels in patients with severe TBI, were that serum TIMP-1 levels were associated with TBI mortality and could be used as a prognostic biomarker of mortality in TBI patients
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