2,317 research outputs found

    Functional Anatomy: Dynamic States in Basal Ganglia Circuits

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    The most appealing models of how the basal ganglia function propose distributed patterns of cortical activity selectively interacting with striatal networks to yield the execution of context-dependent movements. If movement is encoded by patterns of activity then these may be disrupted by influences at once more subtle and more devastating than the increase or decrease of neuronal firing that dominate the usual models of the circuit. In the absence of dopamine the compositional capabilities of cell assemblies in the network could be disrupted by the generation of dominant synchronous activity that engages most of the system. Experimental evidence about Parkinson's disease suggests that dopamine loss produces abnormal patterns of activity in different nuclei. For example, increased oscillatory activity arises in the GPe, GPi, and STN and is reflected as increased cortical beta frequency coherence disrupting the ability to produce motor sequences. When the idea of deep brain stimulation was proposed – it was supported by the information that lesions of the subthalamus reversed the effects of damage to the dopamine input to the system. However, it seems increasingly unlikely that the stimulation acts by silencing the nucleus as was at first proposed. Perhaps the increased cortical beta activity caused by the lack of dopamine could have disabled the patterning of network activity. Stimulation of the subthalamic nucleus disrupts the on-going cortical rhythms. Subsequently asynchronous firing is reinstated and striatal cell assemblies and the whole basal ganglia circuit engage in a more normal pattern of activity. We will review the different variables involved in the generation of sequential activity patterns, integrate our data on deep brain stimulation and network population dynamics, and thus provide a novel interpretation of functional aspects of basal ganglia circuitry

    The role of diet and other environmental factors in the causation of gastric cancer in Iran—A population based study

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    Despite a declining trend in the incidence of gastric cancer (GC), it is still a major global public health concern of the 21st century. The rates of GC reported from Ardabil Province, Iran, are among the highest in the world. To investigate risk factors for GC in Ardabil, we undertook a population-based case-control study. The study aimed to recruit all Ardabil residents newly diagnosed with GC in the time period of 2004–2005, and 2 controls per case. Participants were interviewed using a structured questionnaire. Ten milliliters of blood was collected for blood grouping and investigating the presence of IgG antibodies against Helicobacter pylori. During the study period, 217 people with GC and 394 controls were recruited. In multivariate analysis, diet and Helicobacter pylori infection (OR 5 2.41; 95% CI: 1.35–4.32) were found to be the factors that were most strongly related to GC. High intake of Allium vegetables (OR 5 0.35) and fruit, especially citrus fruit (OR 5 0.31) and consumption of fresh fish (OR 5 0.37) were significantly protective. On the other hand, consumption of red meat (OR 5 3.40) and dairy products (OR 5 2.28) were positively associated with the risk of GC. People who had a preference for higher salt intake (OR 5 3.10) and drinking strong and hot tea (OR 5 2.64 and 2.85, respectively) were at higher risk. In conclusion, Helicobacter pylori infection as measured by serum IgG as well as the consumption of red meat and dairy products increases the risk of GC in Ardabil, while the intake of fresh fruit and fresh fish decrease the risk

    Synchronized activation of striatal direct and indirect pathways underlies the behavior in unilateral dopamine‐depleted mice

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    For more than three decades it has been known, that striatal neurons become hyperactive after the loss of dopamine input, but the involvement of dopamine (DA) D1‐ or D2‐receptor‐expressing neurons has only been demonstrated indirectly. By recording neuronal activity using fluorescent calcium indicators in D1 or D2 eGFP‐expressing mice, we showed that following dopamine depletion, both types of striatal output neurons are involved in the large increase in neuronal activity generating a characteristic cell assembly of particular neurons that dominate the pattern. When we expressed channelrhodopsin in all the output neurons, light activation in freely moving animals, caused turning like that following dopamine loss. However, if the light stimulation was patterned in pulses the animals circled in the other direction. To explore the neuronal participation during this stimulation we infected normal mice with channelrhodopsin and calcium indicator in striatal output neurons. In slices made from these animals, continuous light stimulation for 15 s induced many cells to be active together and a particular dominant group of neurons, whereas light in patterned pulses activated fewer cells in more variable groups. These results suggest that the simultaneous activity of a large dominant group of striatal output neurons is intimately associated with parkinsonian symptoms

    Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

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    OBJECTIVE: It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage. METHODS: We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student's t-test. RESULTS: The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group. CONCLUSION: For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion

    Repression of ergosterol biosynthesis is essential for stress resistance and is mediated by the Hog1 MAP kinase and the Mot3 and Rox1 transcription factors

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    [EN] Hyperosmotic stress triggers a complex adaptive response that is dominantly regulated by the Hog1 MAP kinase in yeast. Here we characterize a novel physiological determinant of osmostress tolerance, which involves the Hog1-dependent transcriptional downregulation of ergosterol biosynthesis genes (ERG). Yeast cells considerably lower their sterol content in response to high osmolarity. The transcriptional repressors Mot3 and Rox1 are essential for this response. Both factors together with Hog1 are required to rapidly and transiently shut down transcription of ERG2 and ERG11 upon osmoshock. Mot3 abundance and its binding to the ERG2 promoter is stimulated by osmostress in a Hog1-dependent manner. As an additional layer of control, the expression of the main transcriptional activator of ERG gene expression, Ecm22, is negatively regulated by Hog1 and Mot3/Rox1 upon salt shock. Oxidative stress also triggers repression of ERG2, 11 transcription and a profound decrease in total sterol levels. However, this response was only partially dependent on Mot3/Rox1 and Hog1. Finally, we show that the upc2-1 mutation confers stress insensitive hyperaccumulation of ergosterol, overexpression of ERG2, 11 and severe sensitivity to salt and oxidative stress. Our results indicate that transcriptional control of ergosterol biosynthesis is an important physiological target of stress signalling.We thank J.M. Mulet for his help with the quantification of intracellular ion concentrations, W.A. Prinz (NIH, Bethesda, MD) and A.K. Menon (Weill Cornell Medical College, New York) for the kind gift of the upc2-1 strain, F. Winston (Harvard Medical School, Boston) for the kind gift of the MOT3-18myc strain, and Avelino Corma (Instituto de Tecnologia Quimica, Valencia, Spain) for making available an ICP optical emission spectrometer for ion content determination. This work was supported by grants from Ministerio de Educacion y Ciencia (BFU2005-01714), from Ministerio de Ciencia e Innovacion (BFU2008-00271) and from Consejo Superior de Investigaciones Cientificas (200820I019). F.M. is recipient of an FPI predoctoral fellowship from Ministerio de Educacion y Ciencia.Martínez Montañés, FV.; Pascual-Ahuir Giner, MD.; Proft ., MH. (2010). Repression of ergosterol biosynthesis is essential for stress resistance and is mediated by the Hog1 MAP kinase and the Mot3 and Rox1 transcription factors. Molecular Microbiology. 79(4):1008-1023. https://doi.org/10.1111/j.1365-2958.2010.07502.xS1008102379

    Muscle molecular adaptations to endurance exercise training are conditioned by glycogen availability: a proteomics-based analysis in the McArdle mouse model

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    KEY POINTS: Although they are unable to utilize muscle glycogen, McArdle mice adapt favourably to an individualized moderate-intensity endurance exercise training regime. Yet, they fail to reach the performance capacity of healthy mice with normal glycogen availability. There is a remarkable difference in the protein networks involved in muscle tissue adaptations to endurance exercise training in mice with and without glycogen availability. Indeed, endurance exercise training promoted the expression of only three proteins common to both McArdle and wild-type mice: LIMCH1, PARP1 and TIGD4. In turn, trained McArdle mice presented strong expression of mitogen-activated protein kinase 12 (MAPK12). ABSTRACT: McArdle's disease is an inborn disorder of skeletal muscle glycogen metabolism that results in blockade of glycogen breakdown due to mutations in the myophosphorylase gene. We recently developed a mouse model carrying the homozygous p.R50X common human mutation (McArdle mouse), facilitating the study of how glycogen availability affects muscle molecular adaptations to endurance exercise training. Using quantitative differential analysis by liquid chromatography with tandem mass spectrometry, we analysed the quadriceps muscle proteome of 16-week-old McArdle (n = 5) and wild-type (WT) (n = 4) mice previously subjected to 8 weeks' moderate-intensity treadmill training or to an equivalent control (no training) period. Protein networks enriched within the differentially expressed proteins with training in WT and McArdle mice were assessed by hypergeometric enrichment analysis. Whereas endurance exercise training improved the estimated maximal aerobic capacity of both WT and McArdle mice as compared with controls, it was ∼50% lower than normal in McArdle mice before and after training. We found a remarkable difference in the protein networks involved in muscle tissue adaptations induced by endurance exercise training with and without glycogen availability, and training induced the expression of only three proteins common to McArdle and WT mice: LIM and calponin homology domains-containing protein 1 (LIMCH1), poly (ADP-ribose) polymerase 1 (PARP1 - although the training effect was more marked in McArdle mice), and tigger transposable element derived 4 (TIGD4). Trained McArdle mice presented strong expression of mitogen-activated protein kinase 12 (MAPK12). Through an in-depth proteomic analysis, we provide mechanistic insight into how glycogen availability affects muscle protein signalling adaptations to endurance exercise training.The CNIC is supported by the Ministry of Economy, Industry and Competitiveness (MEIC) and the Pro CNIC Foundation, and is a Severo Ochoa Centre of Excellence (SEV-2015-0505). This study was funded by grants from Fondo de Investigaciones Sanitarias (PI15/01756, PI15/00558, PI12/00914, and PI14/00903), cofinanced by FEDER. G.N.G. is supported by a Miguel Servet research contract (ISCIII CD14/00032 and FEDER) and C.F.L. by a Sara Borrell post doc contract (CD14/00005). Miguel A. Mart´ın is supported by Fondo de Investigaciones Sanitarias (FIS 15/00432). Tomˆas Pin ´os is supported by Fondo de Investigaciones Sanitarias (FIS PI16/01492).S

    Efficacy and safety of sensor-augmented pump therapy (SAPT) with predictive low-glucose management in patients diagnosed with type 1 diabetes mellitus previously treated with SAPT and low glucose suspend

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    Introducción La terapia con bomba de insulina integrada a sistema de monitoreo continuo con suspensión en hipoglucemia (SAPT-LGS) es una alternativa efectiva y segura para el tratamiento en pacientes con diabetes tipo 1 (DM1). La función de suspensión antes del límite bajo (PLGM) reduce la gravedad y la duración de los eventos hipoglucémicos. Sin embargo, la evidencia del beneficio en pacientes tratados previamente con SAPT-LGS es limitada. Métodos Se realizó un estudio longitudinal antes y después con pacientes DM1 tratados con SAPT-LGS que se cambiaron al sistema Minimed® 640G con SmartGuard®, con el fin de evaluar el impacto en los niveles de A1c, hipoglucemia severa (HS), hipoglucemia asintomática (HA) y área bajo la curva (AUC) <70mg/dl después de tres meses de seguimiento. Resultados Se incluyeron 55 pacientes con DM1, de 37.9 (IQR 6, 79) años, A1c basal de 7.52±1.11%. A los 3 meses bajo PLGM, la A1c se redujo significativamente a 7.18%±0.91% (p=0.004). La tasa de HS se redujo de 2.47 (CI 0.44,4.90) a 0.87 (CI 0.22,1.52) eventos/año del paciente (índice de incidencia 0.353 IC 95%, 0.178, 0.637), el AUC <70mg/dl se redujo de 0,59±0,76 a 0,35±0,65mg/dl x minuto (p = 0,030). HA determinado por el cuestionario Clarke resolvió en 23 de 30 pacientes (p=0,002) Conclusiones Este estudio sugiere que PLGM reduce la frecuencia de HS, HA, la exposición a niveles de glucosa por debajo de 70mg/dl y A1c. Con base a estos resultados, esta terapia debería considerarse en pacientes con DM1 tratados previamente con SAPT-LGS que persisten con HS e HA. Se requieren ensayos clínicos adicionales que comparen la eficacia y la seguridad de estas características.Q4Q3Artículo original451-457Background Sensor-augmented insulin pump therapy (SAPT) with low-glucose suspend (LGS) is an effective and safe alternative for treating patients with type 1 diabetes mellitus (T1DM). New predictive low-glucose management (PLGM) systems decrease the severity and duration of hypoglycemic events. However, evidence of benefits in patients previously treated with SAPT-LGS is limited. Methods A prospective before-after study was conducted in patients with T1DM treated with SAPT-LGS, who were switched to the Minimed® 640G system with SmartGuard® to assess the impact on A1c levels, severe hypoglycemia (SH), hypoglycemia unawareness (HU), and area under the curve (AUC) <70mg/dL after three months of follow-up. Results Fifty-five patients with T1DM with a mean age of 37.9 (IQR 6, 79) years and a mean baseline A1c level of 7.52±1.11% were enrolled. After three months under PLGM, A1c levels significantly decreased to 7.18±0.91% (p=0.004). SH rate decreased from 2.47 (CI 0.44, 4.90) to 0.87 (CI 0.22, 1.52) events/patient-year (Incidence rate ratio 0.353, 95% CI 0.178, 0.637), AUC <70mg/dL decreased from 0.59±0.76 to 0.35±0.65mg/dL x minute (p=0.030). HU determined by Clarke questionnaire resolved in 23 out of 30 patients (p=0.002). Conclusions This study suggests that SAPT with PLGM decreases the frequency of SH, HU, exposure to glucose levels below 70mg/dL, and A1c levels. Based on these results, this therapy should be considered in T1DM patients previously treated with SAPT-LGS with persistent SH and HU. Further clinical trials comparing the efficacy and safety of these features are required

    Turismo y Género. Una mirada desde Iberoamérica

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    En las últimas cuatro décadas ha crecido el interés de la academia, gobiernos y organizaciones internacionales por estudiar cómo ha sido, en qué circunstancias y qué efectos ha traído la incorporación de las mujeres al turismo. De esta forma se inicia un debate internacional en el que se cuestionan, por un lado, los efectos negativos de esta actividad en la vida de las mujeres y, por el otro, se realzan beneficios económicos que mejoran su calidad de vida y la de sus familias. A pesar del interés y la importante participación de mujeres en el sector turístico, aún son insuficientes los estudios enfocados en explicar y evidenciar su situación laboral. En este contexto, surge la idea de publicar un libro que compilara trabajos recientes en torno a las condiciones de las trabajadoras en el sector turístico de Iberoamérica.Esta obra se compone de tres secciones, Aproximaciones teórico metodológicas, Mujer y turismo en zonas rurales y La mujer en empresas turísticas, cuyas investigaciones abordan distintos temas para evidenciar los problemas enfrentados por las mujeres, proponer diversas soluciones y comprender su escenario laboral. En la primera sección, hay dos capítulos que proponen marcos teóricos para analizar el empoderamiento de las mujeres en el turismo rural. Los resultados de investigaciones de la segunda sección visibilizan las desigualdades, reflexionan y proponen acciones para mejorar las condiciones de las trabajadoras turísticas. En la última, en los tres capítulos, concentrados en las actividades empresariales, se estudian las desventajas y obstáculos de la empleada en alguna compañía turística.Universidad Autónoma del Estado de México
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