2,362 research outputs found

    Pesticide Exposure Alters Follicle-Stimulating Hormone Levels in Mexican Agricultural Workers

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    Organophosphorous pesticides (OPs) are suspected of altering reproductive function by reducing brain acetylcholinesterase activity and monoamine levels, thus impairing hypothalamic and/or pituitary endocrine functions and gonadal processes. Our objective was to evaluate in a longitudinal study the association between OP exposure and serum levels of pituitary and sex hormones. Urinary OP metabolite levels were measured by gas–liquid chromatography, and serum pituitary and sex hormone levels by enzymatic immunoassay and radioimmunoassay in 64 men. A total of 147 urine and blood samples were analyzed for each parameter. More than 80% of the participants had at least one OP metabolite in their urine samples. The most frequent metabolite found was diethylthiophosphate (DETP; 55%), followed by diethylphosphate (DEP; 46%), dimethylthiophosphate (DMTP; 32%), and dimethyldithiophosphate (DMDTP; 31%). However, the metabolites detected at higher concentrations were DMTP, DEP, DMDTP, and dimethylphosphate. There was a high proportion of individuals with follicle-stimulating hormone (FSH) concentrations outside the range of normality (48%). The average FSH serum levels were higher during the heavy pesticide spraying season. However, a multivariate analysis of data collected in all periods showed that serum FSH levels were negatively associated with urinary concentrations of both DMTP and DMDTP, whereas luteinizing hormone (LH) was negatively associated with DMTP. We observed no significant associations between estradiol or testosterone serum levels with OP metabolites. The hormonal disruption in agricultural workers presented here, together with results from experimental animal studies, suggests that OP exposure disrupts the hypothalamic–pituitary endocrine function and also indicates that FSH and LH are the hormones most affected

    Fasting enhances pyroglutamyl peptidase II activity in tanycytes of the mediobasal hypothalamus of male adult rats

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    Fasting down-regulates the hypothalamus-pituitary-thyroid (HPT) axis activity through a reduction of TRH synthesis in neurons of the parvocellular paraventricular nucleus of the hypothalamus (PVN). These TRH neurons project to the median eminence (ME), where TRH terminals are close to the cytoplasmic extensions of β2 tanycytes. Tanycytes express pyroglutamyl peptidase II (PPII), the TRH-degrading ectoenzyme that controls the amount of TRH that reaches the anterior pituitary. We tested the hypothesis that regulation of ME PPII activity is another mechanism by which fasting affects the activity of the HPT axis. Semiquantitative in situ hybridization histochemistry data indicated that PPII and deiodinase 2 mRNA levels increased in tanycytes after 48 hours of fasting. This increase was transitory, followed by an increase of PPII activity in the ME, and a partial reversion of the reduction in PVN pro-TRH mRNA levels and the number of TRH neurons detected by immunohistochemistry. In fed animals, adrenalectomy and corticosterone treatment did not change ME PPII activity 72 hours later. Methimazole-induced hypothyroidism produced a profound drop in tanycytes PPII mRNA levels, which was reverted by 3 days of treatment with T4. The activity of thyroliberinase, the serum isoform of PPII, was increased at most fasting time points studied. We conclude that delayed increases in both the ME PPII as well as the thyroliberinase activities in fasted male rats may facilitate the maintenance of the deep down-regulation of the HPT axis function, despite a partial reactivation of TRH expression in the PVN

    Comunidades mexicanas en EU e inversión en México. Un estudio exploratorio

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    El presente trabajo analiza las actitudes generales de inversión en México de la población mexicana en eu, buscando precisar la intención de inversión en México por parte de aquellos individuos de origen mexicano con mayores niveles de ingreso. Los resultados muestran un interés aparente por realizar inversiones en México aun cuando estas inversiones impliquen rendimientos menores a los de mercado. Se plantea que las comunidades mexicanas en eu pueden efectivamente convertirse en poblaciones objeto de políticas de atracción de inversión extranjera directa (ied) a México. Asimismo, no se aprecia que exista una percepción de ventajas étnicas para la inversión en México por parte de los entrevistados. Los resultados muestran que cualquier política de atracción de inversiones dirigidas a las comunidades mexicanas en eu implica necesariamente una mejora en los niveles de inseguridad y corrupción existentes en el paí

    Criterios e indicadores para la evaluación de la calidad en las instituciones de educación superior (IES)

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    La variedad de elementos utilizados en los procesos de evaluación, acreditación y certificación, demuestran la heterogeneidad de criterios y factores incluidos en trabajos, muchas veces sin un sustente metodológico, que indique a las instituciones de educación superior (IES), la manera de asumir el liderazgo para fomentar la cultura de calidad y contribuir a la evolución del sistema de educación superior. Los criterios e indicadores utilizados para evaluar la calidad en las ies y su desempeño en México se estudian tomando como base las sugerencias que hicieron la Unesco, el Banco Mundial (BM), el Banco Interamericano de Desarrollo (BID), y la Organización para la cooperación y el Desarrollo Económico (OCDE) en asuntos relacionados con la educación superior en los países en vías de desarrollo; y analizando los estudios acerca de este tema en las universidades de algunos países como Francia, México, Países Bajos, Australia y Finlandia acerca de la evaluación de la calidad en la educación superior. Finalmente, se presenta una propuesta para implementar criterios e indicadores orientados a la evaluación de la calidad en las IES

    Factores clínicos e inmunológicos asociados a la nefritis lúpica en pacientes del noroeste de Colombia.

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    Este estudio transversal y multicéntrico investigó las características clínicas e inmunológicas asociadas con la nefritis lúpica en pacientes colombianos de Medellín. Se incluyeron treinta y nueve pacientes con nefritis lúpica y se compararon sus características con las de 100 pacientes con lupus eritematoso sistémico (LES) sin compromiso renal. Se realizó un análisis multivariado para evaluar los factores asociados con la nefritis lúpica. Los pacientes que desarrollaron nefritis presentaron, al inicio, más úlceras orales (41% vs. 21%, OR=3,1, IC95%: 1,3-7,5, p=0,01)y eritema malar (77% vs. 45%, OR=4,4, IC95%: 1,8-10,8, p=0,001) que aquellos pacientes sin nefropatía. La nefritis lúpica se observó en 77% de los casos durante el primer año de evolución del LES. La frecuencia de anticuerpos anti-ADN fue mayor en los pacientes con nefritis; sine mbargo, las diferencias no fueron significativas (83% vs. 64%, OR=2,57, IC95%:1,03-6,41,p=0,06). La presencia de otros anticuerpos (anti-Ro, anti-La, anti-RNP, anti-Sm y anticardiolipina)en el momento del diagnóstico fue similar en ambos grupos. El perfil de los autoanticuerpos permaneció sin modificación significativa durante el curso del LES. Los pacientes con nefritis lúpica presentaron una mayor prevalencia de hipertensión arterial (60% vs 10%, OR=13,7,IC95%: 5-37, p=0,00001) y dislipidemia (30% vs 7%, OR=8,1, IC95%: 2,5-27, p=0,0006) al inicio de la enfermedad que aquellos pacientes sin nefropatía. Los pacientes con nefritis lúpica requirieron más hospitalizaciones (>1) durante el curso de la enfermedad (89% vs 60%, OR=7,8,IC95%: 2,1-29, p=0,002). En conclusión, la nefritis lúpica se presenta tempranamente en el LES. El eritema malar, las úlceras orales, la hipertensión arterial y la dislipidemia son factores asociados. A su vez, la nefritis lúpica es un factor de riesgo de hospitalizaciones repetidas. Este estudio puede ser útil en la toma de decisiones de políticas de salud para beneficio de los pacientes y reducción de costos.A cross-sectional and multicenter study was undertaken to analyze the clinical andimmunological characteristics at diagnosis associated with nephritis in northwesternColombian patients with systemic lupus erythematosus (SLE). Thirty nine patients with lupusnephritis were included and were compared to 100 SLE patients without nephritis. A multivariateanalysis was performed. The patients who developed nephritis had a higher frequency of oralulcers (41% vs. 21%, OR=3.1, 95%CI: 1.3-7.5 p= 0.01) and malar erythema (77% vs. 45%,OR=4.4, 95%CI: 1.8-10.8 p=0.001). Lupus nephritis was observed in 77% of cases during thefirst year of the disease. The frequency of anti-DNA antibodies was higher in patients withnephritis, however, differences were not statistically significant (83% vs 64%, OR=2.6, 95%CI:1.03-6.41, p=0.06). The presence of other autoantibodies (anti-Ro, anti-La, anti-RNP, anti-Smand anticardiolipin) at diagnosis was similar in both groups. This autoantibody profile remainedunchanged throughout the evolution of the disease. Patients with lupus nephritis had a higherprevalence of arterial hypertension (60% vs 10%, OR=13.7, 95%IC: 5-37, p=0.00001) andhyperlipidemia (30% vs 7%, OR=8.1, 95%IC: 2.5-27, p=0.0006) at onset. Finally, patients withlupus nephritis required more hospitalizations (>1) over the course of disease (89% vs 60%,OR=7.8, 95%CI: 2.1–29, p=0.002). In conclusion, lupus nephritis appears early during thecourse of SLE. Malar erythema, oral ulcers, hypertension and hyperlipidemia at onset of diseaseare associated factors. Lupus nephritis is a major risk factor leading to repeatedhospitalizations. This study may help to assist in public health policies in our population inorder to improve patient outcomes while simultaneously reducing disease costs

    Nonconventional Wastewater Treatment for the Degradation of Fuel Oxygenated (MTBE, ETBE, and TAME)

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    Catalytic wet air oxidation (CWAO) is a nonconventional wastewater treatment, consisting of oxygen pressure releasing inside a reactor in order to degrade organic compounds dissolved in water, using a solid catalyst in the presence of an activated O2 species, usually at temperatures ranges of 125–250°C and pressures of 10–50 bar. CWAO can reduce operating costs of conventional treatment due to the use of ideal catalyst that is able to improve reaction conditions at temperatures and pressures as mild as possible, simultaneously setting high catalytic activity and long-term stability of heterogeneous catalysts. Oxygenated fuels are gasoline additives in reformulated gasoline and oxyfuels. In the beginning, they provided an alternative solution of environmental problems, such as greenhouse gas emissions and octane enhancement, caused by fossil fuel use. The oxygenated fuels frequently used are methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). However, there is environmental impact from oxygenated fuel hydrocarbons related to widespread contamination of groundwater and other natural waters. Our research group developed a wide study in order to evaluate several catalysts (Ru, Au, Cu, and Ag supported on Al2O3, Al2O3-CeO2, and TiO2-CeO2) and to obtain the best for the efficiency of the oxidation process

    Impaired Mitophagy and Protein Acetylation Levels in Fibroblasts from Parkinson's Disease Patients

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    Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder. While most PD cases are idiopathic, the known genetic causes of PD are useful to understand common disease mechanisms. Recent data suggests that autophagy is regulated by protein acetylation mediated by histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities. The changes in histone acetylation reported to be involved in PD pathogenesis have prompted this investigation of protein acetylation and HAT and HDAC activities in both idiopathic PD and G2019S leucine-rich repeat kinase 2 (LRRK2) cell cultures. Fibroblasts from PD patients (with or without the G2019S LRRK2 mutation) and control subjects were used to assess the different phenotypes between idiopathic and genetic PD. G2019S LRRK2 mutation displays increased mitophagy due to the activation of class III HDACs whereas idiopathic PD exhibits downregulation of clearance of defective mitochondria. This reduction of mitophagy is accompanied by more reactive oxygen species (ROS). In parallel, the acetylation protein levels of idiopathic and genetic individuals are different due to an upregulation in class I and II HDACs. Despite this upregulation, the total HDAC activity is decreased in idiopathic PD and the total HAT activity does not significantly vary. Mitophagy upregulation is beneficial for reducing the ROS-induced harm in genetic PD. The defective mitophagy in idiopathic PD is inherent to the decrease in class III HDACs. Thus, there is an imbalance between total HATs and HDACs activities in idiopathic PD, which increases cell death. The inhibition of HATs in idiopathic PD cells displays a cytoprotective effect

    European Sea Bass (Dicentrarchus labrax) immune status and disease resistance are impaired by arginine dietary supplementation

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    Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the immune response. Aiming at finding out how arginine affects the innate immune status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A third diet meeting arginine requirement level for seabass served as control diet. Following 15 or 29 days of feeding, fish were sampled for blood, spleen and gut to assess cell-mediated immune parameters and immune-related gene expression. At the same time, fish from each dietary group were challenged against Vibrio anguillarum and survival was monitored. Cell-mediated immune parameters such as the extracellular superoxide and nitric oxide decreased in fish fed arginine-supplemented diets. Interleukins and immune-cell marker transcripts were down-regulated by the highest supplementation level. Disease resistance data were in accordance with a generally depressed immune status, with increased susceptibility to vibriosis in fish fed arginine supplemented diets. Altogether, these results suggest a general inhibitory effect of arginine on the immune defences and disease resistance of European seabass. Still, further research will certainly clarify arginine immunomodulation pathways thereby allowing the validation of its potential as a prophylactic strategy.European Union's Seventh Framework Programme AQUAEXCEL (Aquaculture Infrastructures for Excellence in European Fish Research) [262336]; AQUAIMPROV [NORTE-07-0124-FEDER-000038]; North Portugal Regional Operational Programme (ON. 2 - O Novo Norte) , under the National Strategic Reference Framework, through the European Regional Development Fund; North Portugal Regional Operational Programme (ON. 2 - O Novo Norte), under the National Strategic Reference Framework through the COMPETE - Operational Competitiveness Programme; Fundacao para a Ciencia e Tecnologia; Fundacao para a Ciencia e Tecnologia [SFRH/BD/89457/2012, SFRH/BPD/77210/2011]; Generalitat Valenciana through the project REVIDPAQUA [ISIC/2012/003]; [PEst-C/MAR/LA0015/2013]; [UID/Multi/04423/2013]info:eu-repo/semantics/publishedVersio

    A High Statistics Measurement of the Lambdac+ Lifetime

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    A high statistics measurement of the Lambdac+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis technique with particular attention to the determination of the systematic uncertainty. The measured value of 204.6 +/- 3.4 (stat.) +/- 2.5 (syst.) fs from 8034 +/- 122 Lambdac -> pKpi decays represents a significant improvement over the present world average.Comment: Submitted to Physical Review Letter
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