424 research outputs found

    Tau oligomers impair memory and induce synaptic and mitochondrial dysfunction in wild-type mice

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    <p>Abstract</p> <p>Background</p> <p>The correlation between neurofibrillary tangles of tau and disease progression in the brains of Alzheimer's disease (AD) patients remains an area of contention. Innovative data are emerging from biochemical, cell-based and transgenic mouse studies that suggest that tau oligomers, a pre-filament form of tau, may be the most toxic and pathologically significant tau aggregate.</p> <p>Results</p> <p>Here we report that oligomers of recombinant full-length human tau protein are neurotoxic in vivo after subcortical stereotaxic injection into mice. Tau oligomers impaired memory consolidation, whereas tau fibrils and monomers did not. Additionally, tau oligomers induced synaptic dysfunction by reducing the levels of synaptic vesicle-associated proteins synaptophysin and septin-11. Tau oligomers produced mitochondrial dysfunction by decreasing the levels of NADH-ubiquinone oxidoreductase (electron transport chain complex I), and activated caspase-9, which is related to the apoptotic mitochondrial pathway.</p> <p>Conclusions</p> <p>This study identifies tau oligomers as an acutely toxic tau species in vivo, and suggests that tau oligomers induce neurodegeneration by affecting mitochondrial and synaptic function, both of which are early hallmarks in AD and other tauopathies. These results open new avenues for neuroprotective intervention strategies of tauopathies by targeting tau oligomers.</p

    The Entomopathogenic Fungal Endophytes Purpureocillium lilacinum (Formerly Paecilomyces lilacinus) and Beauveria bassiana Negatively Affect Cotton Aphid Reproduction under Both Greenhouse and Field Conditions

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    The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these endophytes for the biological control of aphids and other herbivores under greenhouse and field conditions

    The Disease Burden of Suicide in Ecuador, A 15 years' Geodemographic Cross-Sectional Study (2001-2015)

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    Objective: To describe the epidemiology, demographic characteristics, trends and burden of suicide in Ecuador from 2001 to 2015. Methods: A country-wide comparison was performed using the Ministry of Public Health's national databases of overall mortality, Hospital Discharges Database, and the Population Census of the National Institute of Census and Statistics (INEC). The study variables analyzed were age, geographical distribution to provincial level, sex, means of suicide, educational attainment, marital status and mortality. Linear Regression and relative Risk analysis were used to predict outcome and the likelihood that suicide occur among study variables Results: In the last 15 years, 13,024 suicides were officially reported. Men were 3 times more likely than women to die by suicide. The overall age-adjusted suicide ratio in Ecuador corresponds to 7.1 per 100,000 per year. The sex-specific rates were 5.3 in women and 13.2 in men. The primary mean of suicide was hanging X70 (51.1%), followed by self-poisoning X68-X69 (35.2%) and firearms X72-X74 (7.6%). Provinces located at higher altitude reported higher rates than those located at sea level (9 per 100,000 vs 4.5 per 100.000). The total economic loss due to suicide was estimated to be $852.6 million during the 15 years' analysis. Conclusions: This is the first geodemographic study exploring the complete burden of suicide in Ecuador and one of the very few in Latin-America. In the last 15 years of available data, Ecuador ranks above the regional average with an adjusted suicide rate of 7.1 per 100,000 inhabitants. An important finding is that Suicide affects rather younger populations, adding more than 10,000 years of premature years of life lost (YYL) between 2001 and 2015, becoming the first and fourth leading cause of death among adolescent women and men respectively. Suicide affects people from different backgrounds, socioeconomic status and educational attainment. The mean of suicide changed over time showing that gun and pesticides related deaths decreased significantly since 2001, while hanging and suffocation increased in more than 50%

    Protocolo para detectar la variabilidad genética de Spodoptera frugiperda smith (Lepidoptera: Noctuidae) en algodonero, arroz y maíz en Colombia

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    En Colombia la producción de maíz,arroz y algodonero se ve limitada por S.frugiperda (gusano cogollero).Actualmente, existen referencias de dos biotipos:(1) maíz–algodón y (2) arroz. Morfológicamente indistinguibles, pero que exhiben respuesta diferencial a insecticidas y Bt. El propósito de esta investigación,es documentar la composición genética de S.frugiperda en Colombia

    COVID Obesity: A One-Year Narrative Review

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    On 11 March 2020, coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization (WHO). This study focuses on a narrative review about the illness during the first year of the pandemic in relation to obesity. Databases were used to search studies published up to 8 December 2020. In total, 4430 articles and other scientific literature were found, and 24 articles were included in this one-year narrative review. The mean BMI value of severe COVID-19 patients ranged from 24.5 to 33.4 kg/m2, versus <18.5 to 24.3 kg/m2 for non-severe patients. Articles using the terms obesity or overweight without indicating the BMI value in these patients were common, but this is not useful, as the anthropometric parameters, when not defined by this index, are confusing due to the classification being different in the West compared to among Asian and Korean criteria-based adults. We proposed a new term, called COVID obesity, to define the importance of this anthropometric parameter, among others, in relation with this pandemic

    Transient cardiac dysfunction but elevated cardiac and kidney biomarkers 24 h following an ultra-distance running event in Mexican Tarahumara.

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    BACKGROUND: The Mexican Tarahumara are accustomed to running ultra-distance races. No data exist on the acute physiological changes following ultra-distance running and physiological-biomarker associations in this population. Thus, we aimed to investigate the acute impact (≤ 24 h) on functional and biochemical changes of the cardiac muscle and biochemical changes associated with kidney function following a 63-km ultra-distance race with an altitude difference of 1800 m in Mexican Tarahumara athletes. METHODS: Ten Tarahumara male athletes (mean ± SD age = 29.9 ± 6.6 years) volunteered to participate in the study. VO2max was assessed by a sub-maximal step test individually calibrated combining heart rate and accelerometry. Standard transthoracic echocardiography methodology and venipuncture blood tests were carried out at four time points: pre-race, immediately post-race, 6 h, and 24 h post-race. RESULTS: Estimated mean VO2max was 54.5 (± 8.8) mL O2 min-1 kg-1 and average physiological activity intensity was 746 (± 143) J min-1 kg -1 (~ 11.5 METs). When compared to pre-race values, significant changes in left ventricular ejection fraction (LVEF) and LV end-diastolic volume (- 15%, p < 0.001 for both parameters), cardiac output (39%, p < 0.001), and maximal longitudinal velocity (- 13%, p < 0.009) were seen post-race with LVEF also being decreased at < 6 h post-race (- 8%, p < 0.014). Plasma biomarkers mid-regional pro-atrial natriuretic peptide, copeptin-ultra sensitive, and high-sensitivity cardiac troponin T remained significantly elevated at 24 h post-race, and the two latter were inversely associated with LVEF (p < 0.04). Kidney dysfunction was indicated by increased post-race copeptin-ultra sensitive. CONCLUSIONS: The athletes participating in this study had acute transient cardiac dysfunction as assessed by echocardiography but elevated cardiac and kidney biomarkers at 24 h following a 63-km race with extreme altitude variation

    Prospective space model for San Francisco de Sales by 2036

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    13 páginas : mapasAnte la constante influencia espacial que ejerce la ciudad de Bogotá, capital de Colombia, en los municipios periféricos dentro del departamento de Cundinamarca, se evidencia, principalmente, por factores como su proximidad espacial a la capital y sus condiciones climáticas atractivas a los residentes citadinos para culminar su vejez, que las dinámicas del sistema urbano-rural tradicional están cambiando en el municipio de San Francisco de Sales. Por su localización estratégica provincial y al ser territorio de potencialidades sobre todo a nivel ambiental y para la despensa de alimentos, en este estudio se plantea un modelo prospectivo de ordenamiento territorial al año 2036 con el fin de contrarrestar los efectos perjudiciales del fenómeno desde la perspectiva de la nueva ruralidad.Given the constant spatial influence exerted by the city of Bogotá, capital of Colombia, in the peripheral municipalities within the department of Cundinamarca, it is evidenced, mainly, by factors such as its spatial proximity to the capital and its attractive climatic conditions for city residents to culminate its old age, that the dynamics of the traditional urban-rural system are changing in the municipality of San Francisco de Sales. Due to its provincial strategic location and being a territory of potentialities, especially at the environmental level and for the food pantry, this study proposes a prospective model of territorial planning to the year 2036 in order to counteract the harmful effects of the phenomenon from the perspective of the new rurality
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