115 research outputs found

    Endoplasmic Reticulum Calcium Regulates the Retrotranslocation of Trypanosoma Cruzi Calreticulin to the Cytosol

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    For most secretory pathway proteins, crossing the endoplasmic reticulum (ER) membrane is an irreversible process. However, in some cases this flow can be reversed. For instance, misfolded proteins retained in the ER are retrotranslocated to the cytosol to be degraded by the proteasome. This mechanism, known as ER associated degradation (ERAD), is exploited by several bacterial toxins to gain access to the cytosol. Interestingly, some ER resident proteins can also be detected in the cytosol or nucleus, calreticulin (CRT) being the most studied. Here we show that in Trypanosoma cruzi a minor fraction of CRT localized to the cytosol. ER calcium depletion, but not increasing cytosolic calcium, triggered the retrotranslocation of CRT in a relatively short period of time. Cytosolic CRT was subsequently degraded by the proteasome. Interestingly, the single disulfide bridge of CRT is reduced when the protein is located in the cytosol. The effect exerted by ER calcium was strictly dependent on the C-terminal domain (CRT-C), since a CRT lacking it was totally retained in the ER, whereas the localization of an unrelated protein fused to CRT-C mirrored that of endogenous CRT. This finding expands the regulatory mechanisms of protein sorting and may represent a new crossroad between diverse physiological processes

    Jocs motors Una alternativa per enfortir els músculs de l’abdomen

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    L’objectiu de l’estudi va ser comparar l’amplitud de l’electromiografia (EMG) i la forma en què van ser coactivats els músculs abdominals durant l’execució de l’exercici d’encorbament del tronc i dos jocs motors tradicionals: el carretó i l’hula-hop. Per fer-ho, es va enregistrar l’EMG dels músculs recte, oblic extern i oblic intern de l’abdomen, durant l’execució de cada una de les tasques. A l’estudi hi van participar nou voluntaris sans, sense antecedents de cirurgia abdominal, lesions raquídies o síndrome de dolor lumbar. L’amplitud de l’EMG va ser amitjanada i normalitzada respecte a la contracció voluntària màxima. Es va realitzar un ANOVA de dos factors (múscul/tasca) i un post hoc Tukey per examinar les diferències en l’activitat elèctrica de cada múscul entre les tasques i en cada tasca entre els músculs. Els jocs analitzats van produir nivells d’activitat elèctrica superiors als generats per l’encorbament del tronc, i en conseqüència, han de ser considerats com un complement o una alternativa als exercicis d’enfortiment abdominal. El carretó va generar un important nivell de coactivació abdominal, encara que va activar principalment l’oblic extern de l’abdomen. A l’hula-hop, les diferències entre els músculs no van ser estadísticament significatives

    Asociación de obesidad con la Enfermedad Renal Crónica de pacientes atendidos en la Clínica de la Costa. 2005-2014

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    Introduction: Obesity is a risk factor for the development and the progression of the Chronic Kidney Disease (CKD). In Latin America there are few studies where the stages of CKD and the degrees of obesity are related.Objective:The objective of the study is to evaluate the association of obesity with the chronic renal disease in patients seen in the extern consult of the department of Nephrology at the Clinic of the Coast in Barran-quilla, Colombia.Materials and Methods: A descriptive case series study was conducted. The sample consisted of 300 pa-tients collected in NefroRed©. Measurements of central tendency Y and X2were conducted to establish the association between degrees of obesity with CKD stages. Statistical analyseswere performed in R-CRAN. When the test was realized an association between degrees of obesity and the different stages of CKD was found [x2: 48.62; p-value <0.01].Conclusion: No statistical evidence of association was found between waist circumference and the stages of CKD [x2: 8.82; p-value ? 0.05]. There is an association between levels of obesity and the different stages of CKD. No relationship between waist circumference and the stages of CKD was found.Introducción: La obesidad es un factor de riesgo de desarrollo y progresión de enfermedad renal crónica (ERC). En Latinoamérica existen pocos estudios donde se relacionen los estadios de ERC y grados de obesidad.Objetivo: El objetivo de estudio es evaluar la asociación de obesidad con la enfermedad renal crónica de pacientes atendidos en la consulta externa del departamento de Nefrología en la Clínica de la Costa en Barranquilla, Colombia.Materiales y métodos: Se realizó un estudio observacional descriptivo tipo serie de casos. La muestra estuvo compuesta por 300 pacientes acopiados en NefroRed©. Se realizaron medidas de tendencia central y un ?² para establecer la asociación entre los grados de obesidad con los estadios de la ERC. Los análisis estadísticos se realizaron en R-CRAN. Al realizar la prueba, se encontró una asociación entre los grados de obesidad y los diferentes estadios de la ERC [?²: 48,62; p-valor < 0,01].Conclusión: No se encontró evidencia estadística de asociación entre el Perímetro Abdominal y los estadios de ERC [?²: 8,82; p-valor ? 0,05]. Existe asociación entre los grados de obesidad y los diferentes estadios de la ERC. No se encontró la relación entre perímetro abdominal y los estadios de ERC

    Biochemical parameters of silver catfish (Rhamdia quelen) after transport with eugenol or essential oil of Lippia alba added to the water

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    The transport of live fish is a routine practice in aquaculture and constitutes a considerable source of stress to the animals. The addition of anesthetic to the water used for fish transport can prevent or mitigate the deleterious effects of transport stress. This study investigated the effects of the addition of eugenol (EUG) (1.5 or 3.0 mu L L-1) and essential oil of Lippia alba (EOL) (10 or 20 mu L L-1) on metabolic parameters (glycogen, lactate and total protein levels) in liver and muscle, acetylcholinesterase activity (AChE) in muscle and brain, and the levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and nonprotein thiol groups (NPSH) and activity of glutathione-S-transferase in the liver of silver catfish (Rhamdia quelen; Quoy and Gaimard, 1824) transported for four hours in plastic bags (loading density of 169.2 g L-1). The addition of various concentrations of EUG (1.5 or 3.0 mu L L-1) and EOL (10 or 20 mu L L-1) to the transport water is advisable for the transportation of silver catfish, since both concentrations of these substances increased the levels of NPSH antioxidant and decreased the TBARS levels in the liver. In addition, the lower liver levels of glycogen and lactate in these groups and lower AChE activity in the brain (EOL 10 or 20 mu L L-1) compared to the control group indicate that the energetic metabolism and neurotransmission were lower after administration of anesthetics, contributing to the maintenance of homeostasis and sedation status.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Pesquisa e Desenvolvimento Cientifico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); CNPqinfo:eu-repo/semantics/publishedVersio

    Crosstalk between HIV and hepatitis C virus during co-infection

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    An estimated one-third of individuals positive for HIV are also infected with hepatitis C virus (HCV). Chronic infection with HCV can lead to serious liver disease including cirrhosis and hepatocellular carcinoma. Liver-related disease is among the leading causes of death in patients with HIV, and individuals with HIV and HCV co-infection are found to progress more rapidly to serious liver disease than mono-infected individuals. The mechanism by which HIV affects HCV infection in the absence of immunosuppression by HIV is currently unknown. In a recent article published in BMC Immunology, Qu et al. demonstrated that HIV tat is capable of inducing IP-10 expression. Further, they were able to show that HIV tat, when added to cells, was able to enhance the replication of HCV. Importantly, the increase in HCV replication by tat was found to be dependent on IP-10. This work has important implications for understanding the effect HIV has on the outcome of HCV infection in co-infected individuals. The findings of Qu et al. may inform the design of intervention and treatment strategies for co-infected individuals

    Study of Leading Hadrons in Gluon and Quark Fragmentation

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    The study of quark jets in e+e- reactions at LEP has demonstrated that the hadronisation process is reproduced well by the Lund string model. However, our understanding of gluon fragmentation is less complete. In this study enriched quark and gluon jet samples of different purities are selected in three-jet events from hadronic decays of the Z collected by the DELPHI experiment in the LEP runs during 1994 and 1995. The leading systems of the two kinds of jets are defined by requiring a rapidity gap and their sum of charges is studied. An excess of leading systems with total charge zero is found for gluon jets in all cases, when compared to Monte Carlo Simulations with JETSET (with and without Bose-Einstein correlations included) and ARIADNE. The corresponding leading systems of quark jets do not exhibit such an excess. The influence of the gap size and of the gluon purity on the effect is studied and a concentration of the excess of neutral leading systems at low invariant masses (<~ 2 GeV/c^2) is observed, indicating that gluon jets might have an additional hitherto undetected fragmentation mode via a two-gluon system. This could be an indication of a possible production of gluonic states as predicted by QCD.Comment: 19 pages, 6 figures, Accepted by Phys. Lett.

    Lung cancer mortality in towns near paper, pulp and board industries in Spain: a point source pollution study

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    <p>Abstract</p> <p>Background</p> <p>This study sought to ascertain whether there might be excess lung cancer mortality among the population residing in the vicinity of Spanish paper and board industries which report their emissions to the European Pollutant Emission Register (EPER).</p> <p>Methods</p> <p>This was an ecological study that modelled the Standardised Mortality Ratio (SMR) for lung cancer in 8073 Spanish towns over the period 1994–2003. Population exposure to industrial pollution was estimated on the basis of distance from town of residence to pollution source. An exploratory, near-versus-far analysis was conducted, using mixed Poisson regression models and an analysis of the effect of municipal proximity within a 50-kilometre radius of each of the 18 installations.</p> <p>Results</p> <p>Results varied for the different facilities. In two instances there was an increasing mortality gradient with proximity to the installation, though this was exclusively observed among men.</p> <p>Conclusion</p> <p>The study of cancer mortality in areas surrounding pollutant foci is a useful tool for environmental surveillance, and serves to highlight areas of interest susceptible to being investigated by ad hoc studies. Despite present limitations, recognition is therefore due to the advance represented by publication of the EPER and the study of pollutant foci.</p

    Measurement of inclusive π0\pi^{0} production in hadronic Z0Z^{0} decays

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    An analysis is presented of inclusive \pi^0 production in Z^0 decays measured with the DELPHI detector. At low energies, \pi^0 decays are reconstructed by \linebreak using pairs of converted photons and combinations of converted photons and photons reconstructed in the barrel electromagnetic calorimeter (HPC). At high energies (up to x_p = 2 \cdot p_{\pi}/\sqrt{s} = 0.75) the excellent granularity of the HPC is exploited to search for two-photon substructures in single showers. The inclusive differential cross section is measured as a function of energy for {q\overline q} and {b \bar b} events. The number of \pi^0's per hadronic Z^0 event is N(\pi^0)/ Z_{had}^0 = 9.2 \pm 0.2 \mbox{(stat)} \pm 1.0 \mbox{(syst)} and for {b \bar b}~events the number of \pi^0's is {\mathrm N(\pi^0)/ b \overline b} = 10.1 \pm 0.4 \mbox{(stat)} \pm 1.1 \mbox{(syst)} . The ratio of the number of \pi^0's in b \overline b events to hadronic Z^0 events is less affected by the systematic errors and is found to be 1.09 \pm 0.05 \pm 0.01. The measured \pi^0 cross sections are compared with the predictions of different parton shower models. For hadronic events, the peak position in the \mathrm \xi_p = \ln(1/x_p) distribution is \xi_p^{\star} = 3.90^{+0.24}_{-0.14}. The average number of \pi^0's from the decay of primary \mathrm B hadrons is found to be {\mathrm N} (B \rightarrow \pi^0 \, X)/\mbox{B hadron} = 2.78 \pm 0.15 \mbox{(stat)} \pm 0.60 \mbox{(syst)}

    b-tagging in DELPHI at LEP

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