The international journal of biochemistry & cell biology, Dec 31, 2016
Sepsis-induced myocardial dysfunction is associated with increased oxidative stress and mitochond... more Sepsis-induced myocardial dysfunction is associated with increased oxidative stress and mitochondrial dysfunction. Current evidence suggests a protective role of thioredoxin-1 (Trx1) in the pathogenesis of cardiovascular diseases. However, it is unknown yet a putative role of Trx1 in sepsis-induced myocardial dysfunction, in which oxidative stress is an underlying cause. Transgenic male mice with Trx1 cardiac-specific overexpression (Trx1-Tg) and its wild-type control (wt) were subjected to cecal ligation and puncture or sham surgery. After 6, 18, and 24h, cardiac contractility, antioxidant enzymes, protein oxidation, and mitochondrial function were evaluated. Trx1 overexpression improved the average life expectancy (Trx1-Tg: 36, wt: 28h; p=0.0204). Sepsis induced a decrease in left ventricular developed pressure in both groups, while the contractile reserve, estimated as the response to β-adrenergic stimulus, was higher in Trx1-Tg in relation to wt, after 6h of the procedure. Trx1 ...
El procesamiento de una muestra en el laboratorio implica su paso a través de tres etapas: la pre... more El procesamiento de una muestra en el laboratorio implica su paso a través de tres etapas: la preanalítica, la analítica y la postanalítica. En el presente trabajo se propuso analizar la etapa preanalítica para la determinación del estado ácido-base (EAB) a través de la comparación de muestras extraídas en diferentes tipos de jeringas y del efecto del tiempo de almacenamiento, estudiar el desempeño analítico y la concordancia entre dos analizadores gemelos y evaluar si los resultados permiten trabajar bajo las especificaciones de calidad requeridas. Para ello se utilizaron 2 microprocesadores automáticos de gases en sangre en los cuales se midieron pH, pCO2 y pO2, y se fijaron las especificaciones de calidad derivadas de CLIA (Clinical Laboratory Improvement Amendments) como requerimento a cumplir. La imprecisión intraensayo (CVi) y entreensayos (CVe) fue determinada con material de control comercial. Sobre un total de 239 muestras de pacientes, 20 se utilizaron para realizar la comparación entre muestras extraídas en jeringas con heparina sódica en solución y con heparina de litio liofilizada; 110 muestras se procesaron para evaluar el efecto del tiempo de almacenamiento y 109 para la comparación entre ambos instrumentos. Los CVi y CVe fueron aceptables para los 3 parámetros. Las diferencias halladas entre las muestras obtenidas con las diferentes jeringas no superaron los límites permitidos. No se observaron diferencias significativas en los resultados hasta los 120 minutos de procesamiento. Los coeficientes de correlación de las muestras procesadas en ambos instrumentos fueron 0,931 para pH, 0,985 para pCO2 y 0,950 para pO2. El sesgo fue aceptable así como también el porcentaje de equivalencia clínica para los tres parámetros. Se concluye que la evaluación de los resultados de instrumentos gemelos y la implementación de programas sistemáticos de conmutabilidad son fundamentales para conseguir la disminución progresiva del error y para poder utilizarlos indistintamente.
Background & AimsHepatocyte apoptosis, the hallmark of non‐alcoholic steatohepatitis (NASH) contr... more Background & AimsHepatocyte apoptosis, the hallmark of non‐alcoholic steatohepatitis (NASH) contributes to liver injury and fibrosis. Although, both the intrinsic and extrinsic apoptotic pathways are involved in the pathogenesis of NASH, the final common step of apoptosis is executed by a family of cysteine‐proteases termed caspases. Thus, our aim was to ascertain if administration of Emricasan, a pan‐caspase inhibitor, ameliorates liver injury and fibrosis in a murine model of NASH.MethodsC57/BL6J‐mice were fed regular chow or high fat diet (HFD) for 20 weeks. All mice were treated with vehicle or Emricasan.ResultsMice fed a HFD diet demonstrate a five‐fold increase in hepatocyte apoptosis by the TUNEL assay and a 1.5‐fold and 1.3‐fold increase in caspase‐3 and‐8 activities respectively; this increase in apoptosis was substantially attenuated in mice fed a HFD treated with Emricasan (HFD‐Em). Likewise, liver injury and inflammation were reduced in mice fed HFD‐Em as compare to HFD ...
Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive... more Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive increase of reactive oxygen and nitrogen species (ROS/RNS) and mitochondrial dysfunction. Despite intensive research, determining events in the progression or reversal of the disease are incompletely understood. Herein, we studied two prototype sepsis models: endotoxemia and cecal ligation and puncture (CLP)-which showed very different lethality rates (2.5% and 67%, respectively)-, evaluated iNOS, ROS and respiratory chain activity, and investigated mitochondrial biogenesis and dynamics, as possible processes involved in sepsis outcome. Endotoxemia and CLP showed different iNOS, ROS/RNS, and complex activities time-courses. Moreover, these alterations reverted after 24-h endotoxemia but not after CLP. Mitochondrial biogenesis was not elicited during the first 24 h in either model but instead, 50% mtDNA depletion was observed. Mitochondrial fusion and fission were evaluated using real-time PCR of mitofusin-2 (Mfn2), dynamin-related protein-1 (Drp1), and using electron microscopy. During endotoxemia, we observed a decrease of Mfn2-mRNA levels at 4-6 h, and an increase of mitochondrial fragmentation at 6 h. These parameters reverted at 24 h. In contrast, CLP showed not only decreased Mfn2-mRNA levels at 12-18 h but also increased Drp1-mRNA levels at 4 h, and enhanced and sustained mitochondrial fragmentation. The in vivo pretreatment with mdivi-1 (Drp1 inhibitor) significantly attenuated mitochondrial dysfunction and apoptosis in CLP. Therefore, abnormal fusion-to-fission balance, probably evoked by ROS/RNS secondary to iNOS induction, contributes to the progression of sepsis. Pharmacological targeting of Drp1 may be a potential novel therapeutic tool for sepsis.
Mitochondria are specialized organelles that control energy metabolism and also activate a multip... more Mitochondria are specialized organelles that control energy metabolism and also activate a multiplicity of pathways that modulate cell proliferation and mitochondrial biogenesis or, conversely, promote cell arrest and programmed cell death by a limited number of oxidative or nitrative reactions. Nitric oxide (NO) regulates oxygen uptake by reversible inhibition of cytochrome oxidase and the production of superoxide anion from the mitochondrial electron transfer chain. In this sense, NO produced by mtNOS will set the oxygen uptake level and contribute to oxidation-reduction reaction (redox)–dependent cell signaling. Modulation of translocation and activation of neuronal nitric oxide synthase (mtNOS activity) under different physiologic or pathologic conditions represents an adaptive response properly modulated to adjust mitochondria to different cell challenges.
A 1-year prospective study about the prevalence of intestinal parasitism from January 2001 to Feb... more A 1-year prospective study about the prevalence of intestinal parasitism from January 2001 to February 2002, is presented. We have studied a population (n = 692), who arrived at the laboratory to be submitted to parasitologic test. The concentration technique and the Graham test were employed. Fifteen known pathogens were isolated among 45% of the patients. Protozoa were more prevalent than helmints. Among adults the most frequent enteropathogen was Blastocystis hominis (28.07% IC 95% 23.37-33.15) and among children Enterobius vermicularis (26.86% IC 95% 22.28-31.82) and B. hominis (24.86% IC 95% 20.42-29.73) were the more common. We didn't find statistically significant difference between the number of B. hominis in fecal samples and symptoms (p = 0.2780). As we expected, the people who always use not drinking water showed more percent of parasitism, but there wasn't statistical significant difference in the comparative study with the people who drink good water (p = 0.68)....
Resumen es: El procesamiento de una muestra en el laboratorio implica su paso a traves de tres et... more Resumen es: El procesamiento de una muestra en el laboratorio implica su paso a traves de tres etapas: la preanalitica, la analitica y la postanalitica. En el presen...
Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive... more Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive increase of reactive oxygen and nitrogen species (ROS/RNS) and mitochondrial dysfunction. Despite intensive research, determining events in the progression or reversal of the disease are incompletely understood. Herein, we studied two prototype sepsis models: endotoxemia and cecal ligation and puncture (CLP)-which showed very different lethality rates (2.5% and 67%, respectively)-, evaluated iNOS, ROS and respiratory chain activity, and investigated mitochondrial biogenesis and dynamics, as possible processes involved in sepsis outcome. Endotoxemia and CLP showed different iNOS, ROS/RNS, and complex activities time-courses. Moreover, these alterations reverted after 24-h endotoxemia but not after CLP. Mitochondrial biogenesis was not elicited during the first 24 h in either model but instead, 50% mtDNA depletion was observed. Mitochondrial fusion and fission were evaluated using real-time PCR of mitofusin-2 (Mfn2), dynamin-related protein-1 (Drp1), and using electron microscopy. During endotoxemia, we observed a decrease of Mfn2-mRNA levels at 4-6 h, and an increase of mitochondrial fragmentation at 6 h. These parameters reverted at 24 h. In contrast, CLP showed not only decreased Mfn2-mRNA levels at 12-18 h but also increased Drp1-mRNA levels at 4 h, and enhanced and sustained mitochondrial fragmentation. The in vivo pretreatment with mdivi-1 (Drp1 inhibitor) significantly attenuated mitochondrial dysfunction and apoptosis in CLP. Therefore, abnormal fusion-to-fission balance, probably evoked by ROS/RNS secondary to iNOS induction, contributes to the progression of sepsis. Pharmacological targeting of Drp1 may be a potential novel therapeutic tool for sepsis.
The international journal of biochemistry & cell biology, Dec 31, 2016
Sepsis-induced myocardial dysfunction is associated with increased oxidative stress and mitochond... more Sepsis-induced myocardial dysfunction is associated with increased oxidative stress and mitochondrial dysfunction. Current evidence suggests a protective role of thioredoxin-1 (Trx1) in the pathogenesis of cardiovascular diseases. However, it is unknown yet a putative role of Trx1 in sepsis-induced myocardial dysfunction, in which oxidative stress is an underlying cause. Transgenic male mice with Trx1 cardiac-specific overexpression (Trx1-Tg) and its wild-type control (wt) were subjected to cecal ligation and puncture or sham surgery. After 6, 18, and 24h, cardiac contractility, antioxidant enzymes, protein oxidation, and mitochondrial function were evaluated. Trx1 overexpression improved the average life expectancy (Trx1-Tg: 36, wt: 28h; p=0.0204). Sepsis induced a decrease in left ventricular developed pressure in both groups, while the contractile reserve, estimated as the response to β-adrenergic stimulus, was higher in Trx1-Tg in relation to wt, after 6h of the procedure. Trx1 ...
El procesamiento de una muestra en el laboratorio implica su paso a través de tres etapas: la pre... more El procesamiento de una muestra en el laboratorio implica su paso a través de tres etapas: la preanalítica, la analítica y la postanalítica. En el presente trabajo se propuso analizar la etapa preanalítica para la determinación del estado ácido-base (EAB) a través de la comparación de muestras extraídas en diferentes tipos de jeringas y del efecto del tiempo de almacenamiento, estudiar el desempeño analítico y la concordancia entre dos analizadores gemelos y evaluar si los resultados permiten trabajar bajo las especificaciones de calidad requeridas. Para ello se utilizaron 2 microprocesadores automáticos de gases en sangre en los cuales se midieron pH, pCO2 y pO2, y se fijaron las especificaciones de calidad derivadas de CLIA (Clinical Laboratory Improvement Amendments) como requerimento a cumplir. La imprecisión intraensayo (CVi) y entreensayos (CVe) fue determinada con material de control comercial. Sobre un total de 239 muestras de pacientes, 20 se utilizaron para realizar la comparación entre muestras extraídas en jeringas con heparina sódica en solución y con heparina de litio liofilizada; 110 muestras se procesaron para evaluar el efecto del tiempo de almacenamiento y 109 para la comparación entre ambos instrumentos. Los CVi y CVe fueron aceptables para los 3 parámetros. Las diferencias halladas entre las muestras obtenidas con las diferentes jeringas no superaron los límites permitidos. No se observaron diferencias significativas en los resultados hasta los 120 minutos de procesamiento. Los coeficientes de correlación de las muestras procesadas en ambos instrumentos fueron 0,931 para pH, 0,985 para pCO2 y 0,950 para pO2. El sesgo fue aceptable así como también el porcentaje de equivalencia clínica para los tres parámetros. Se concluye que la evaluación de los resultados de instrumentos gemelos y la implementación de programas sistemáticos de conmutabilidad son fundamentales para conseguir la disminución progresiva del error y para poder utilizarlos indistintamente.
Background & AimsHepatocyte apoptosis, the hallmark of non‐alcoholic steatohepatitis (NASH) contr... more Background & AimsHepatocyte apoptosis, the hallmark of non‐alcoholic steatohepatitis (NASH) contributes to liver injury and fibrosis. Although, both the intrinsic and extrinsic apoptotic pathways are involved in the pathogenesis of NASH, the final common step of apoptosis is executed by a family of cysteine‐proteases termed caspases. Thus, our aim was to ascertain if administration of Emricasan, a pan‐caspase inhibitor, ameliorates liver injury and fibrosis in a murine model of NASH.MethodsC57/BL6J‐mice were fed regular chow or high fat diet (HFD) for 20 weeks. All mice were treated with vehicle or Emricasan.ResultsMice fed a HFD diet demonstrate a five‐fold increase in hepatocyte apoptosis by the TUNEL assay and a 1.5‐fold and 1.3‐fold increase in caspase‐3 and‐8 activities respectively; this increase in apoptosis was substantially attenuated in mice fed a HFD treated with Emricasan (HFD‐Em). Likewise, liver injury and inflammation were reduced in mice fed HFD‐Em as compare to HFD ...
Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive... more Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive increase of reactive oxygen and nitrogen species (ROS/RNS) and mitochondrial dysfunction. Despite intensive research, determining events in the progression or reversal of the disease are incompletely understood. Herein, we studied two prototype sepsis models: endotoxemia and cecal ligation and puncture (CLP)-which showed very different lethality rates (2.5% and 67%, respectively)-, evaluated iNOS, ROS and respiratory chain activity, and investigated mitochondrial biogenesis and dynamics, as possible processes involved in sepsis outcome. Endotoxemia and CLP showed different iNOS, ROS/RNS, and complex activities time-courses. Moreover, these alterations reverted after 24-h endotoxemia but not after CLP. Mitochondrial biogenesis was not elicited during the first 24 h in either model but instead, 50% mtDNA depletion was observed. Mitochondrial fusion and fission were evaluated using real-time PCR of mitofusin-2 (Mfn2), dynamin-related protein-1 (Drp1), and using electron microscopy. During endotoxemia, we observed a decrease of Mfn2-mRNA levels at 4-6 h, and an increase of mitochondrial fragmentation at 6 h. These parameters reverted at 24 h. In contrast, CLP showed not only decreased Mfn2-mRNA levels at 12-18 h but also increased Drp1-mRNA levels at 4 h, and enhanced and sustained mitochondrial fragmentation. The in vivo pretreatment with mdivi-1 (Drp1 inhibitor) significantly attenuated mitochondrial dysfunction and apoptosis in CLP. Therefore, abnormal fusion-to-fission balance, probably evoked by ROS/RNS secondary to iNOS induction, contributes to the progression of sepsis. Pharmacological targeting of Drp1 may be a potential novel therapeutic tool for sepsis.
Mitochondria are specialized organelles that control energy metabolism and also activate a multip... more Mitochondria are specialized organelles that control energy metabolism and also activate a multiplicity of pathways that modulate cell proliferation and mitochondrial biogenesis or, conversely, promote cell arrest and programmed cell death by a limited number of oxidative or nitrative reactions. Nitric oxide (NO) regulates oxygen uptake by reversible inhibition of cytochrome oxidase and the production of superoxide anion from the mitochondrial electron transfer chain. In this sense, NO produced by mtNOS will set the oxygen uptake level and contribute to oxidation-reduction reaction (redox)–dependent cell signaling. Modulation of translocation and activation of neuronal nitric oxide synthase (mtNOS activity) under different physiologic or pathologic conditions represents an adaptive response properly modulated to adjust mitochondria to different cell challenges.
A 1-year prospective study about the prevalence of intestinal parasitism from January 2001 to Feb... more A 1-year prospective study about the prevalence of intestinal parasitism from January 2001 to February 2002, is presented. We have studied a population (n = 692), who arrived at the laboratory to be submitted to parasitologic test. The concentration technique and the Graham test were employed. Fifteen known pathogens were isolated among 45% of the patients. Protozoa were more prevalent than helmints. Among adults the most frequent enteropathogen was Blastocystis hominis (28.07% IC 95% 23.37-33.15) and among children Enterobius vermicularis (26.86% IC 95% 22.28-31.82) and B. hominis (24.86% IC 95% 20.42-29.73) were the more common. We didn't find statistically significant difference between the number of B. hominis in fecal samples and symptoms (p = 0.2780). As we expected, the people who always use not drinking water showed more percent of parasitism, but there wasn't statistical significant difference in the comparative study with the people who drink good water (p = 0.68)....
Resumen es: El procesamiento de una muestra en el laboratorio implica su paso a traves de tres et... more Resumen es: El procesamiento de una muestra en el laboratorio implica su paso a traves de tres etapas: la preanalitica, la analitica y la postanalitica. En el presen...
Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive... more Sepsis-associated multiple organ failure is a major cause of mortality characterized by a massive increase of reactive oxygen and nitrogen species (ROS/RNS) and mitochondrial dysfunction. Despite intensive research, determining events in the progression or reversal of the disease are incompletely understood. Herein, we studied two prototype sepsis models: endotoxemia and cecal ligation and puncture (CLP)-which showed very different lethality rates (2.5% and 67%, respectively)-, evaluated iNOS, ROS and respiratory chain activity, and investigated mitochondrial biogenesis and dynamics, as possible processes involved in sepsis outcome. Endotoxemia and CLP showed different iNOS, ROS/RNS, and complex activities time-courses. Moreover, these alterations reverted after 24-h endotoxemia but not after CLP. Mitochondrial biogenesis was not elicited during the first 24 h in either model but instead, 50% mtDNA depletion was observed. Mitochondrial fusion and fission were evaluated using real-time PCR of mitofusin-2 (Mfn2), dynamin-related protein-1 (Drp1), and using electron microscopy. During endotoxemia, we observed a decrease of Mfn2-mRNA levels at 4-6 h, and an increase of mitochondrial fragmentation at 6 h. These parameters reverted at 24 h. In contrast, CLP showed not only decreased Mfn2-mRNA levels at 12-18 h but also increased Drp1-mRNA levels at 4 h, and enhanced and sustained mitochondrial fragmentation. The in vivo pretreatment with mdivi-1 (Drp1 inhibitor) significantly attenuated mitochondrial dysfunction and apoptosis in CLP. Therefore, abnormal fusion-to-fission balance, probably evoked by ROS/RNS secondary to iNOS induction, contributes to the progression of sepsis. Pharmacological targeting of Drp1 may be a potential novel therapeutic tool for sepsis.
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Papers by Silvia Holod