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RESUMEN Introducción: La cardiopatía isquémica es la principal causa de muerte en la República Argentina. La forma de presentación que prevalece es el infarto de miocardio (IM), caracterizado por insuficiente perfusión sanguínea, muerte celular y pérdida de masa contráctil. La evolución del remodelado ventricular provoca dilatación ventricular, deterioro hemodinámico, insuficiencia cardíaca y disminución de la sobrevida. Durante este proceso existe un estrés oxidativo miocárdico que podría ser atenuado mediante la administración de N-acetil cisteína (NAC), a través de un aumento de los niveles de glutatión. Objetivos: Evaluar el efecto de la NAC sobre el remodelado post IM. Material y métodos: Se estudiaron durante 28 días conejos neozelandeses en tres grupos experimentales: Control, IM e IM+NAC. Bajo anestesia general se realizó una toracotomía izquierda y, en los grupos con IM, ligadura de una rama de la coronaria izquierda. Al finalizar el período de seguimiento posterior al infarto, se realizaron estudios ecocardiográficos, hemodinámicos y morfológicos del ventrículo izquierdo (VI). Resultados: En los grupos IM e IM+NAC los infartos estaban ubicados en la pared libre del VI y tuvieron tamaños similares. La administración de NAC evitó el adelgazamiento de la zona no infartada y disminuyó la dilatación provocada por el infarto. También pudo observarse que preservó las funciones sistólica y diastólica del VI, con atenuación del deterioro que las mismas sufrieron como consecuencia del infarto. Conclusión: Estos resultados sugieren que la administración de NAC es una terapéutica promisoria para mitigar los efectos desfavorables del remodelado post IM.

ABSTRACT Background: Ischemic heart disease is the main cause of death in Argentina. The prevailing form of presentation is myocardial infarction (MI), characterized by insufficient blood perfusion, cell death and loss of contractile mass. The evolution of ventricular remodeling causes ventricular dilation, hemodynamic impairment, heart failure, and decreased survival. The oxidative stress occurring during this process could be attenuated by the administration of N-acetyl cysteine (NAC) through increased glutathione levels. Objectives: The aim of this study was to evaluate the effect of NAC administration on post-MI remodeling. Methods: New Zealand rabbits were divided into three experimental groups: Control, MI and MI+NAC. A left thoracotomy was performed under general anesthesia, and in the MI groups a branch of the left coronary artery was ligated. Echocardiographic, hemodynamic and morphological studies of the left ventricle were performed at the end of the 28-day post infarction follow-up period. Results: In the MI and MI+NAC groups, the infarcts were located in the left ventricular free wall and had similar sizes. The administration of NAC prevented non-infarcted area thinning and decreased the dilation caused by the infarction. It also preserved left ventricular systolic and diastolic functions, attenuating the impairment that they suffered as a consequence of the infarction. Conclusion: These results suggest that NAC administration is a promising therapy to mitigate the unfavorable effects of post-MI remodeling.

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La talidomida fue desarrollada e introducida al mercado por los laboratorios Grünenthal en 1953, siendo usada principalmente como sedante y también para el tratamiento de las náuseas durante el embarazo. Los informes dan cuenta de aproximadamente 10.000 niños que nacieron con focomelia, dando lugar a la denominada "tragedia de la talidomida", que obligó a su retiro del mercado en 1962. Luego de casi 60 años, es nuevamente utilizada en otros campos de la medicina, entre ellos, para el tratamiento de la lepra y del mieloma múltiple, debido a sus propiedades antinflamatorias, inmunomoduladoras y antiangiogénicas, con expresas advertencias sobre su utilización durante el embarazo; no obstante, con su nuevo uso han sido reportados múltiples efectos adversos, entre los que se encuentra la hepatitis aguda o crónica inducida por este fármaco. Se presenta el caso de una paciente de 34 años con lepra, que estaba en tratamiento con talidomida desde hacía 4 años para combatir las lesiones de piel asociadas a esta enfermedad. Presentó malestar general, vómito, pérdida de peso, artralgias, ictericia, edemas de miembros inferiores, ascitis, coluria y acolia. Se sospechó toxicidad por talidomida, por lo que se suspendió su uso, y se trató con ácido ursodesoxicólico y N-acetilcisteína con mejoría sintomática y de laboratorio, desde la primera semana hasta los 41 días de seguimiento. Las entidades clínicas para las cuales se aprobó talidomida en 1998, pueden traer nuevos problemas y desafíos clínicos. Este caso muestra hepatotoxicidad crónica por talidomida, situación que hasta el momento no se había reportado en la literatura.

Thalidomide was developed and introduced to the market by Grünenthal laboratories in 1953, being used mainly as a sedative and also for the treatment of nausea during pregnancy. Reports give account of approximately 10,000 children who were born with phocomelia, giving rise to the so-called "thalidomide tragedy", which forced its withdrawal from the market in 1962. After almost 60 years, it is usedagain in other fields of medicine, including the treatment of leprosy and multiple myeloma, due to its anti-inflammatory, immunomodulatory and anti-angiogenic properties, with clear warnings about its use during pregnancy; however, multiple adverse effects have been reported in patients with leprosy and multiple myeloma, including acute or chronic hepatitis. We present the case of a 34-year-old patient with leprosy, who had been on thalidomide therapy for 4 years to treat skin lesions associated with this disease. She presented general malaise, vomiting, weight loss, arthralgia, jaundice, lower limb edema, ascites, choluria and acholia. Thalidomide toxicity was suspected, so its use was suspended, and treatment with ursodeoxycholic acid and N-acetylcysteine was initiated, with symptomatic and laboratory improvement from the first week up until 41 days of follow-up. The new range of medical conditions for which thalidomide was approved for in 1998 may bring clinical challenges. This case shows chronic hepatotoxicity due to thalidomide, a situation that had not been reported previously in the literature.

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Resumen Introducción: La ototoxicidad por cisplatino es un evento muy frecuente y sus consecuencias producen mucho deterioro en los pacientes. El diagnóstico precoz es esencial, pues permitiría implementar apropiadamente estrategias para aminorar su efecto. Entre estas tenemos la N-acetilcisteína, un agente antioxidante que ha demostrado efecto otoprotector. Objetivo: Evaluar el rol otoprotector de N-acetilcisteína comparado con placebo, en pacientes con cáncer de cabeza y cuello tratados con cisplatino. Material y Método: Ensayo clínico aleatorizado, paralelo y controlado con placebo. Se incluyen pacientes con cáncer de cabeza y cuello que requieren tratamiento con cisplatino, dos ramas: un grupo control que recibe placebo y otro que recibe el fármaco. Se realizan audiometrías de altas frecuencias (6-16 kHz) antes, durante y una vez finalizado el tratamiento. Resultados: Se aleatorizaron 45 pacientes, 23 al grupo intervencional y 22 al grupo control. Se encontró una incidencia general de la ototoxicidad del 73%, un empeoramiento en relación con tiempo de medición, una detención y estabilización del efecto ototóxico en el grupo que recibió N-acetilcisteína, todas estas diferencias fueron significativas. Conclusión: La N-acetilcisteína no previene la ototoxicidad inducida por cisplatino, pero modifica su curso de instalación y progresión. No se registraron efectos adversos al uso del fármaco. El monitoreo audiológico precoz es esencial para identificar la ototoxicidad y ejercer acciones para modificar su curso y mejorar la calidad de vida.

Abstract Introduction: Cisplatin-induced ototoxicity is a very frequent event and its consequences can cause a lot of deterioration in patients. There are some strategies to reduce its effect, among these, N-acetylcysteine, an antioxidant agent, has shown otoprotective effect. Aim: To evaluate the effect of N-acetylcysteine on ototoxicity by chemotherapy-radiotherapy in patients with head and neck cancer, compared with placebo. Material and Method: Randomized, parallel design and placebo controlled clinical trial. Patients with head and neck cancer who require treatment with cisplatin were enrolled: a control group that receives a placebo and experimental group that receives the drug. High-frequency audiometries were performed before, during and after the treatment finalization. Results: Forty-five patients were randomized, 23 for the experimental group and 22 for control group. The investigators found an incidence of ototoxicity of 73%, a worsening in relation to the time of measurement and a stopping and stabilization of the ototoxic effect in the group that received N-acetylcysteine, all these differences were statistically significant. Conclusion: N-acetylcysteine does not prevent cisplatin-induced ototoxicity, but does modify its course of installation and progression. No adverse effects were registered in this trial. Early audiological monitoring is essential to identify ototoxicity and eventually modify its course and improve the quality of life.

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Introdução: Diversos alvos farmacológicos têm sido estudados com o objetivo de minimizar as consequências da infecção causada pelo vírus da COVID-19. A hiperinflamação pulmonar foi associada ao estresse oxidativo embasando a administração de antioxidantes, especialmente N-acetilcisteína, que vem sendo proposta como terapia de suporte e investigada em estudos clínicos. Objetivo: Realizar uma análise crítica do uso da N-acetilcísteina em pacientes com COVID-19 com base em suas propriedades fármaco-toxicológicas. Material e métodos: Análise crítica a partir de revisão bibliográfica de artigos originais e de revisão de dados epidemiológico, clínicos e estudos de caso. Os dados farmacológicose toxicológicos foram comparados para avaliar potenciais riscos e benefícios da adoção desta terapia. Resultado: A fisiopatologia da COVID-19 está associada à hiperinflamação causada pela liberação de citocinas e quimiocinas, denominada tempestade de citocinas que agrava a infecção respiratória, podendo levar ao quadro de Síndrome de Angústia Respiratória Aguda (SARA). Esse conjunto de fatores pode ser responsável pelo aumento do estresse oxidativo que está relacionado com a gravidade da infecção. A N-acetilcisteína parece atenuar o quadro inflamatório pela atividade antioxidante e anti-inflamatória e apresenta baixa toxicidade, sendo bem tolerada em doses de até 500 mg/kg. Conclusão: A N-acetilcisteína possui potencial no tratamento de pacientes com COVID-19 em estágios iniciais da doença para diminuir o estresse oxidativo.

Introduction: Focusing the efforts to minimizing the injury caused by COVID-19 virus, many pharmacological targets have been studied. The lung hyper inflammation was referred as a consequence of the oxidative stress and supports the antioxidant therapy, especially the N-acetylcysteine administration that has been proposed in some clinical studies. Aims: In order to make a critical analysis of COVID-19 clinical management with N-acetylcysteine, the physiopathology of the infection was compared with the pharmacological and toxicological properties of the N-acetylcsteine. Methodology: A literature review was made and the peer-reviewed articles, epidemiologic data, clinical studies and case reports were consulted. The pharmacological and toxicological data were compared to evaluate the potential risks and benefits of the N-acetylcysteine therapy. Results: The COVID-19 physiopathology is based on the hyper inflammation that is a consequence of the cytokines storm (release of a large amount of pro-inflammatory cytokines and chemokines). The hyper inflammation can result in the Severe Acute Respiratory Syndrome (SARS). The cytokines storm was associated with the oxidative stress and the severity of the infection. N-acetylcysteine seems to improve the inflammation by its antioxidant and anti inflammatory properties. Furthermore, N-acetylcysteine shows high tolerability hate in doses until 500 mg/kg. Conclusion: N-acetylcysteine shows high therapeutic potential to decrease the oxidative stress in early stages of the infection in COVID-19 patients.

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Resumen Los parámetros de calidad para endoscopia digestiva alta han introducido indicadores intraprocedimiento, dentro de los cuales la adecuada visibilidad de la mucosa, libre de saliva, moco o burbujas, puede aumentar la posibilidad de detección de lesiones en fase temprana. Sin embargo, el uso de mucolíticos y antiburbujas ha mostrado gran variabilidad de eficiencia según las soluciones, concentraciones, tiempos de exposición y escala de visibilidad aplicados. Objetivos: determinar la efectividad de diferentes soluciones de premedicación para la limpieza de la mucosa digestiva; validar, mediante una prueba de concordancia interobservador, una nueva escala de adecuada visualización de la mucosa (TVMS) para el esófago, estómago y duodeno; y reportar eventos adversos o complicaciones relacionadas con las soluciones utilizadas y los procedimientos realizados. Material y métodos: estudio de cohortes prospectivas comparativas. Se incluyeron 412 pacientes adultos, ASA I y ASA II, para endoscopia diagnóstica bajo sedación consciente, distribuidos en 6 cohortes similares, divididas en dos grupos: no premedicación, 2 cohortes C1 (ayuno de 6 a 8 horas)y C2 (agua 100 mL); premedicación, 4 cohortes C3 a C6 (C3: agua 100 m L + simeticona 1000 mg; C4: agua 100 mL + simeticona 200 mg + N-acetilcisteína 600 mg; C5: agua 100 mL + simeticona 200 mg + N-acetilcisteína 1000 mg; C6: agua 100 mL + simeticona 200 mg + Hedera helix 70 mg). Se ingirió la solución 15 a 30 minutos antes del paso por cricofaríngeo. Se realizó la prueba de Kappa para medir la concordancia interobservador de la escala TVMS. Resultados: De 412 pacientes, 58% fueron de sexo femenino; 23% (136) fue de cohortes C1 y C2 y 67% (276) fue de cohortes C3 a C6. El tiempo medio de exposición a cada solución fue de 24,4 minutos. El volumen de lavado para lograr una adecuada visualización fue significativamente diferente entre ambos grupos: en los pacientes con premedicación se utilizaron 75,6 mL, mientras que en los pacientes sin premedicación se utilizaron 124 mL (p = 0,000), con una calidad de TVMS excelente de 88,7% frente al 41,4%, respectivamente. La cohorte C4 (agua 100 mL + simeticona 200 mg + N-acetilcisteína 600 mg) mostró ser la más efectiva con una diferencia significativa (p = 0,001) frente a C1 (ayuno) y C2 (placebo con agua 100 mL), y también tuvo una eficiencia superior frente a C3, C5 y C6 en su orden. No se presentaron eventos adversos o complicaciones en relación con la endoscopia, la sedación y los productos usados en la premedicación. Conclusiones: la solución más efectiva como premedicación para lograr una excelente visibilidad de la mucosa digestiva correspondió a la cohorte C4 (SIM 200 + NAC 600 + H2O 100 mL). La escala TVMS propuesta es una herramienta muy completa y fácil de aplicar por más de un observador. La premedicación ingerida, con antiburbuja, mucolítico y agua hasta 100 mL, entre 15 y 30 minutos previos a endoscopia, es segura en las condiciones descritas en este estudio.

Abstract Quality parameters for upper gastrointestinal endoscopy have introduced intraprocedural indicators, including adequate mucosal visualization free of saliva, mucus, or bubbles, which may increase the possibility of early-stage injury detection. The use of mucolytics and anti-foaming agents has shown great efficiency variability depending on the type of solution, concentrations, exposure times and visibility scale applied. Objectives: To determine the effectiveness of different premedication solutions for cleaning the digestive mucosa; to validate, by means of an interobserver concordance test, a new scale for the adequate visualization of the mucosa (TVMS) for the esophagus, stomach, and duodenum; and to report adverse events or complications associated with the solutions used and the procedures performed. Material and methods: Prospective, comparative cohort study. 412 adult patients, ASA I and ASA II, were included for diagnostic endoscopy under conscious sedation. They were distributed in 6 similar cohorts and divided into two groups: non-premedication, 2 in C1 (fasting 6 to 8 hours) and C2 (water 100 mL) cohorts; premedication, 4 C3 to C6 cohorts (C3: water 100 mL + simethicone 1000 mg; C4: water 100 ml + simethicone 200 mg + N-acetylcysteine 600 mg; C5: water 100 ml + simethicone 200 mg + N-acetylcysteine 1000 mg; C6: water 100 ml + simethicone 200 mg + Hedera helix 70 mg). The solution was swallowed 15 to 30 minutes passing through the cricopharyngeus muscle. The Kappa test was performed to measure interobserver concordance of the TVMS scale. Results: Of 412 patients, 58% were female; 23% (136) were included in the C1 and C2 cohorts; and 67% (276) were in the C3 to C6 cohorts. The average exposure time to each solution was 24.4 minutes. The wash volume for proper visualization was significantly different between the two groups. In premedicated patients, 75.6 mL of solution were used, while in patients without premedication, 124 mL were used (p = 0.000), with an excellent quality of TVMS of 88.7% versus 41.4%, respectively. The C4 cohort (water 100 mL + simethicone 200 mg + N-acetylcysteine 600 mg) was the most effective with a significant difference (p= 0.001) compared with the C1 (fasting) and C2 (placebo with water 100 mL) cohorts. It also had better efficiency compared to the C3, C5 and C6 cohorts in that order. There were no adverse events or complications associated with endoscopy, sedation, or premedication products. Conclusions: The most effective solution as a premedication to achieve excellent visibility of the digestive mucosa was that used in the C4 cohort (SIM 200 + NAC 600 + H2OR 100 mL). The proposed TVMS scale is a very complete and easy tool to apply by more than one observer. Premedication ingested, with anti-foam, mucolytic and water up to 100 mL, between 15 and 30 minutes before endoscopy, is safe under the conditions described in this study.

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RESUMEN La N-acetilcisteína es conocida en varias especialidades médicas. Su empleo en cardiología se ha incrementado desde hace décadas, por su potencial para disminuir el impacto del daño por reperfusión en el infarto miocárdico agudo. Pero el espectro de sus efectos es aún mayor, tiene acciones sobre los radicales de oxígeno, con un papel protector, por la vía de los grupos sulfhidrilos de regiones importantes de la membrana celular, los cuales interfieren y tienen efecto en la función endotelial y en los procesos complejos de adhesión como efectos secundarios; así como otros fenómenos del compartimento extravascular. Estos procesos están estrechamente relacionados con el aparato cardiovascular.

ABSTRACT N-acetylcysteine is known in a number of medical specialties and its ability to decrease the impact of reperfusion injury in acute myocardial infarction has boosted its use in cardiology over the past decades. N-acetylcysteine has a far-reaching range of effects since it functions as a protective agent against oxygen radicals through sulfhydryl groups in important regions of the cell membrane that interfere and affect endothelial functioning and complex adhesion processes as side effects; as well as other phenomena of the extravascular compartment. These processes are closely related to the cardiovascular system.

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El Paraquat (PQ) es un herbicida de contacto bipiridilico ampliamente utilizado en agricultura. La intoxicación en humanos por este agente ocasiona fibrosis pulmonar. Evaluamos los cambios histológicos pulmonares de ratas intoxicadas con PQ y tratadas con N-aceticisteina (NAC) administrada vía inhalatoria. Realizamos un estudio experimental descriptivo con 25 ratas adultas, machos cepa Wistar, divididas en cinco grupos. Al grupo I no se les administro ni PQ ni NAC. Grupo II, recibió NAC inhalada a 15mg/kg diaria c/12 horas. Grupo III, PQ vía oral (VO) 15mg/kg. Grupo IV, PQ a 15mg/kg, por VO y a la hora NAC 150mg/kg. Grupo V, PQ a 15mg/kg, por VO y a las seis horas NAC dosis de 150mg/kg. Los pulmones fueron extraídos y se evaluaron mediante cortes histológicos. Resultados: Los grupos I y II (supervivencia del 100%, n=10) no desarrollaron sintomatología de intoxicación. Grupos III, IV y V predominaron síntomas respiratorios, diversos grados de edema pulmonar, enfisema, congestión vascular y hemorragia intra-alveolar focal. La eficacia de la NAC sobre la intoxicación por PQ en términos de sobrevivencia al primer día, fue del 100% y al segundo día, fue del 80% (p= 0,005; prueba Chi-cuadrado). El PQ indujo un proceso inflamatorio (agudo-crónico) por infiltrado de segmentados neutrófilos y linfocitos, lo cual fue revertido parcialmente por la administración inhalada de NAC. Conclusión: Los cambios histopatológicos observados a nivel pulmonar fueron aminorados por el tratamiento con NAC, lo que sugiere un posible efecto protector de este fármaco sobre el daño oxidativo inducido por el herbicida

Paraquat (PQ) is a bipyridyl contact herbicide widely used in agriculture. Intoxication in humans by this agent causes pulmonary fibrosis. We evaluated pulmonary histological changes of rats intoxicated with PQ and treated with N-acetycysteine (NAC) administered via inhalation. We conducted a descriptive experimental study with 25 adult rats, male Wistar strain, divided into five groups. Group I was not administered PQ or NAC. Group II, received NAC inhaled at 15mg/kg daily c/12 hours. Group III, PQ orally (VO) 15mg/ kg. Group IV, PQ at 15mg/kg, by VO and at hour NAC 150mg/ kg. Group V, PQ at 15mg/kg, by VO and at six hours NAC dose of 150mg/kg. The lungs were extracted and evaluated by histological sections. Results: Groups I and II (100% survival, n=10) did not develop intoxication symptoms. Groups III, IV and V predominantly respiratory symptoms, various degrees of pulmonary edema, emphysema, vascular congestion and focal intra-alveolar hemorrhage. The efficacy of NAC on PQ poisoning in terms of survival on the first day was 100% and on the second day it was 80% (p = 0.005, Chi-square test). The PQ induced an inflammatory process (acute-chronic) by infiltration of segmented neutrophils and lymphocytes, which was partially reversed by the inhaled administration of NAC. Conclusion: The histopathological changes observed at the pulmonary level were reduced by the treatment with NAC, which suggests a possible protective effect of this drug on the oxidative damage induced by the herbicide.

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Resumen La intoxicación por acetaminofén es una intoxicación frecuente en Colombia y en su tratamiento es fundamental la administración de un antídoto. El manejo convencional con N acetil cisteína presenta potenciales eventos adversos. El objetivo de este reporte de caso es evidenciar la utilidad de un nuevo esquema de tratamiento en un paciente masculino de 19 años quien ingirió 16,5 gramos de acetaminofén y luego de seis horas inició con dolor abdominal y episodios de emésis, para lo cual se inició manejo con N acetil cisteína en la forma tradicionalmente recomendada con la cual desarrolló reacción de hipersensibilidad. Ante la necesidad de continuar con este medicamente se inició un esquema diferente del antídoto con un resultado exitoso y sin nuevas reacciones de hipersensibilidad.

Abstract Toxicity due to Acetaminophen is a very common type of intoxication in Colombia, and in its treatment is essential the administration of an antidote. Conventional management with N acetyl cysteine presents potential adverse events. The objective of this case report is to demonstrate the usefulness of a new treatment scheme in a 19-year-old male patient who ingested 16.5 grams of acetaminophen and after six hours started with abdominal pain and episodes of emesis, for which management was started with N acetyl cysteine in the recommended form and then developed a hypersensitivity reaction. Given the need to continue with this medication, a different antidote scheme was started with a successful result and without new hypersensitivity reactions.

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O objetivo deste estudo foi avaliar in vitro o comportamento biológico celular da N-Acetilcisteína (NAC), diante da estimulação ou não pelo LPS bacteriano. Foram utilizados fibroblastos do ligamento periodontal, que ficaram em contato por 48 horas com as substâncias testadas: NAC, Hidróxido de cálcio p.a. (HC), Lipopolissacarídeo de Escheria Coli (LPS), NAC + LPS e HC + LPS. Para os grupos NAC + LPS, HC + LPS e LPS, as células foram estimuladas com 2µg/mL de LPS por 24 horas, previamente aos tratamentos descritos. Foram realizados os testes biológicos de viabilidade celular (XTT), Espécies Reativas de Oxigênio (ROS), Elisa (para as citocinas IL-6, IL-8, IL-10, IL-1ß e TNF-α) e Micronúcleo (MNT). Os dados foram analisados estatisticamente pela análise descritiva e pelos testes ANOVA e Kruskall Wallis, seguido do teste Dunn (p˂0.05) para os testes de XTT, ROS e MNT, e para o teste Elisa foi realizado cálculo das médias e desvio padrão. Os resultados obtidos mostraram que NAC teve um bom comportamento, frente à agressão provocada pelo LPS, quanto à produção de ROS. HC apresentou maior viabilidade celular que NAC, embora NAC não tenha apresentado citotoxicidade. Em relação à expressão das citocinas, NAC foi capaz de reduzir o potencial inflamatório do LPS quando da análise do TNF- α e IL-1ß. NAC foi capaz de reduzir a genotoxicidade do LPS, como mostrado pelo teste MNT. Concluiu-se que NAC apresentou um comportamento biológico satisfatório, pela viabilidade celular dos fibroblastos, pela redução da geração de ROS e do potencial inflamatório provocado pelo LPS, e por reduzir a sua genotoxicidade (AU)

The purpose of this study was to evaluate in vitro the action of N-Acetylcysteine (NAC) and calcium hydroxide (CH) on biological activity, either without or with LPS stimulation in periodontal ligament fibroblasts (PDLF) cells. PDLF were placed in contact with NAC, CH, NAC + LPS, LPS and CH + LPS for 48 hours. PDLF were stimulated by bacterial LPS for 24 hours in NAC + LPS, LPS and CH + LPS groups, before the substances described above are applied. The LPS and NAC effect on cell viability was measured using a XTT test. Reactive oxygen species (ROS) production was evaluated using ROS/superoxide detection kit. Inflammatory cytokines (IL-6, IL-8, IL-10, IL-1ß and TNF-α) were evaluated by enzyme-linked immunosorbent (ELISA) assay. Genotoxicity was measured using micronucleus test (MNT). The means and standard deviation for all tests were calculated. Data were analyzed statistically by descriptive analysis, ANOVA and Kruskall Wallis tests, followed by Dunn test (p˂.05). CH was superior to NAC on cellular viability, although NAC was not cytotoxic. The results showed that NAC was able to reduce ROS production of LPS. NAC was able to reduce the inflammatory potential of LPS by decreasing the TNF-α and IL-1ß release. NAC was able to reduce the genotoxicity of LPS. It was concluded that NAC showed a satisfactory biological activity, presenting a minimal effect on cell viability of PDLF cells and reducing ROS production and inflammatory potential provoked by LPS, and to decrease its genotoxicity(AU)

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Resumen En Chile, el consumo de pasta base de cocaína (PBC), una sustancia altamente tóxica y adictiva, se ha convertido en un serio problema médico y social en las áreas más pobres del país. Esta sustancia se fuma y provoca rápidamente en el usuario el deseo compulsivo de seguir usándola, así como una gran dificultad para detener su consumo, principalmente debido a los síntomas de abstinencia que genera en el usuario. Hasta la fecha no existen medicamentos con eficacia demostrada para tratar la adicción a la PBC o la adicción a la cocaína, en cualquiera de sus formas. La N-acetilcisteína (NAC), un fármaco utilizado en nuestro país y en todo el mundo, desde hace varios años, para otros fines terapéuticos, ha demostrado beneficios en la reducción de los antojos del consumo de cocaína y la prolongación del tiempo de abstinencia de esta y otras sustancias psicoactivas. Este artículo revisa los aspectos más relevantes de investigaciones recientes sobre la efectividad de NAC para el tratamiento de pacientes con adicción a la cocaína, planteando y justificando la necesidad de evaluar la posible utilidad de este medicamento en el tratamiento de la adicción a PBC, una entidad diferente de la adicción a otras formas de cocaína.

In Chile, the consumption of Cocaine Base Paste (CBP), a highly toxic and addictive substance, has become a serious medical and social problem in the poorest areas of the country. This substance is smoked and quickly provokes in the user the compulsive desire to continue using it, as well as a great difficulty in stopping consumption, mainlydue to the withdrawal symptoms that it generates in the user. To date there are no drugs with proven efficacy to treat CBP addiction or cocaine addiction, in any of its forms. N-acetylcysteine (NAC), a drug used in our country and around the world, from several years, for other therapeutic purposes, has shown benefits in reducing cravings for cocaine use and prolonging the time of abstinence of this and other psychoactive substances. This article reviews the most relevant aspects of recent research about the effectiveness of NAC for the treatment of patients with cocaine addiction, raising and justifying the need to evaluate the possible utility of this medication in the management of CBP addiction, a different entity from the addiction to other forms ofcocaine.

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Resumen Introducción: la visibilidad de la mucosa gástrica puede verse limitada por el moco adherente y la formación de burbujas durante la endoscopia de vías digestivas altas. Objetivos: conocer los puntajes de visualización de la mucosa gástrica y el número de lavados para aclarar la superficie gástrica de burbujas y espumas, aplicando la escala de Kuo modificada por Chang en pacientes premedicados antes de la esofagogastroduodenoscopia. Materiales y métodos: estudio descriptivo, prospectivo, se incluyeron 120 pacientes entre octubre y diciembre de 2016 a los que se les premedicó con N-acetilcisteína (NAC) al 4%, 400 mg (10 cc) más simeticona (SIM) (dimetilpolisiloxano) 133,3 mg (2 cc) y agua tibia 100 cc, 20 minutos antes del procedimiento; los datos se tabularon en Excel y, ulteriormente, sus frecuencias y porcentajes se analizaron con el paquete estadístico Epi Info CDC (versión 7,2 para Windows, Estados Unidos); se consideró significancia estadística una p <0,05. Resultados: la puntuación total de visibilidad de la mucosa gástrica considerada como óptima con un puntaje de 4 fue 57 (47,50%), con 5 puntos fueron 36 (30%), con 6 y 7 puntos 10 (8,33%), con 8 puntos 6 (5%) y, por último, con 9 puntos 1 (0,83%); no hubo casos en las puntuaciones de 10 a 16. 100 (83,3%) pacientes no necesitaron lavados adicionales con agua para visualizar la mucosa gástrica, contra 13 (10,83%) que requirieron menos de 50 cc y 7 (5,83%) que necesitaron más de 50 cc (p = 0,00). Limitaciones: un solo observador realizó el estudio, lo que pudo generar sesgos de detección; además, la muestra es pequeña. Conclusiones: con la administración de una solución de NAC más SIM diluidas en 100 cc de agua tibia previa a la endoscopia de vías digestivas altas se obtuvo una visualización óptima de la mucosa gástrica en la mayoría de los casos y se observó la necesidad de un menor volumen de agua para aclarar la cavidad gástrica de moco y espuma.

Abstract Introduction: During upper digestive tract endoscopy, visibility of the gastric mucosa can be limited by adherent mucus and bubbles. Objectives: This is a study of visualization of the gastric mucosa and the number of washes needed to clear bubbles and foam from the gastric surface. The modified Kuo scale by Chang was used with patients medicated prior to esophagogastroduodenoscopy. Materials and methods: This is a descriptive and prospective study of 120 patients who were medicated with 400 mg (10cc) of 4% N-acetylcysteine plus 133.3 mg (2cc) of simethicone (Dimethylpolysiloxane) and 100 cc of warm water 20 minutes prior to esophagogastroduodenoscopy from October to December 2016. Data were tabulated in Excel and frequencies and percentages were analyzed using the Epi Info statistical package from the Centers for Disease Control version 7.2 for Windows. Statistical significance was considered to be p <0.05. Results: The optimal score for total visibility of four was achieved 57 patients (47.50%). Thirty-six patients (30%) had scores of five points, ten patients (8.33%) had scores of six or seven points, six patients had scores of eight points (5%), and one patient (0.83%) had a score of nine points. There were no scores from 10 to 16. Hundred patients (83,3%) did not need additional washes with water to visualize the gastric mucosa, thirteen patients (10,83%) required less than 50 cc, and seven (5,83%) required more than 50 cc (p = 0.00). Limitations: This study was done by a single observer which could result in detection biases. Also, the sample is small. Conclusions: Administration of a solution of N-acetylcysteine ​​plus Simethicone diluted in 100 cc of warm water prior to upper digestive tract endoscopy provides for optimal visualization of the gastric mucosa in most cases. A smaller volume of water was needed to clear the gastric cavity of mucus and foam.

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O objetivo deste estudo foi avaliar, in vitro, a capacidade antimicrobiana da N-Acetilcisteína (NAC) e da terapia fotodinâmica (PDT) utilizando LASER diodo (LD) de baixa intensidade, sobre o Enterococcus faecalis, comparados ao uso do hidróxido de cálcio [Ca(OH)2] como medicação intracanal. Oitenta dentes humanos extraídos tiveram o diâmetro dos canais radiculares padronizados por meio do preparo com lima K#30. As raízes foram contaminadas com E. faecalis por 21 dias e divididas em cinco grupos de acordo com a medicação intracanal e/ou tratamento antimicrobiano a ser utilizada: 1) PDT+NAC; 2) NAC; 3) PDT; 4) Ca(OH)2 e 5) Solução salina. Sendo que 50 dentes foram avaliados por cultura microbiológica (UFC/mL), 10 por microscopia eletrônica de varredura (MEV) e 20 por microscopia confocal de varredura a LASER (CLSM). Para UFC/mL foram feitas 3 coletas do conteúdo o canal radicular: a) após 21 dias de contaminação (coleta de confirmação - Sc); b) após PBM (S1); c) após 14 dias com as medicações intracanais (S2). UFC/mL não mostrou diferença estatística entre os grupos de PDT+NAC, NAC e Ca(OH)2, porém foram significantemente diferentes dos grupos da PDT, e solução salina. A análise ilustrativa por MEV mostrou resultados semelhantes à análise microbiológica (UFC/mL). No CLSM, todos os grupos avaliados foram efetivos contra E. faecalis, com a diferençando significantemente do grupo controle. Concluímos que NAC pode eliminar E. faecalis com ou sem PDT, sendo considerado como medicação complementar para aplicação clínica(AU)

The objective of this study was to evaluate in vitro the antimicrobial capacity of N-Acetylcysteine (NAC) e PDT photodynamic therapy using low intensity LASER diode (LD) on Enterococcus faecalis, compared to the use of calcium hydroxide Ca(OH)2, as intracanal medication. Eighty extracted human teeth had their root canal diameters steardized by preparation with K 30 file. The roots were contaminated with E. faecalis for 21 days and divided into five groups according to the intracanal medication and/or antimicrobial treatment to be used. 1) PDT + NAC; 2) NAC; 3) PDT; 4) Ca(OH)2; 5) Saline solution. Fifty teeth were evaluated by microbiological culture (CFU/mL), 10 by scanning electron microscopy (SEM), and 20 by confocal LASER scanning microscopy (CLSM). The root canal was collected 3 times a) after 21 days of contamination (confirmation collection) (Sc); b) after biomechanical preparation S1; c) after 14 days with intracanal medications. CFU/mL showed no statistical difference between the PDT+NAC, NAC e Ca(OH)2 groups, but were significantly different from the PDT groups, and saline. The illustrative SEM analysis showed similar results to the analysis (CFU / mL). In CLSM, all evaluated groups were effective against E. faecalis, with a significant difference with the control group. We conclude that NAC can eliminate E. faecalis with or without PDT, being considered as a complementary medication in clinical practice(AU)

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Introduction: Portal hypertension (PH) is characterized by vasodilatation in the portal system and the bowel is one of the severely affected organs. N-acetylcysteine (NAC) is a molecule with important properties and widely used in clinical practice. Objective: To evaluate NAC action in the bowel of animals submitted to the animal model of partial portal vein ligation (PPVL). Methods: 18 male Wistar rats were divided into three experimental groups (n = 6): sham-operated (SO), PPVL, and PPVL + NAC. On the 8th day after surgery, N-acetylcysteine (10 mg/kg, ip) was administered daily for 7 days. On the 15th day the animals' bowel was collected for oxidative stress analysis, immunohistochemistry and Western blot. We evaluated the expression of NF-KB and TNF-α by immunohistochemistry and of iNOS by Western blot. Lipid peroxidation was assessed by TBARS technique, and the activities of antioxidant enzymes superoxide dismutase (SOD) and glutation peroxidase (GPx) were checked. Results: We observed an increased expression of NF-KB and TNF-α in PPVL group, and an increased iNOS expression assessed by Western blot. NAC reduced the expression of all proteins evaluated. We also observed an increase in oxidative stress in the bowel of mice PPVL group compared to controls (SO), and NAC was effective in reducing these values in PPVL + NAC group. Also, a reduction in the activity of SOD and GPx enzymes was observed in the diseased group, and NAC was able to restore the activity of the enzymes assessed. Conclusion: We suggest the anti-inflammatory and antioxidant action of NAC in the bowel of animals submitted to PPVL model.

Introdução: A Hipertensão Portal (HP) é caracterizada por uma vasodilatação no sistema portal, e o intestino é um dos órgãos gravemente acometidos. A N-acetilcisteína (NAC) é uma molécula com importantes propriedades, amplamente utilizada na clínica. Objetivo: Avaliar a ação da NAC no intestino de animais submetidos ao modelo animal de ligadura parcial da veia porta (LPVP). Métodos: Foram utilizados 18 ratos machos Wistar divididos em três grupos experimentais (n = 6): Sham-operated (SO), LPVP, LPVP + NAC. No 8° dia após a cirurgia, a N-acetilcisteína (10 mg/kg,ip) foi administrada diariamente durante 7 dias. No 15° dia foi coletado o intestino dos animais para análises de estresse oxidativo, imunohistoquímica e Western blot. Nós avaliamos a expressão do NF-kb e TNF-α; por imunohistoquímica e da iNOS por Western blot. A lipoperoxidação foi avaliada pela técnica de TBARS, e as atividades das enzimas antioxidantes Superóxido Dismutase (SOD) e GlutationaPeroxidase (GPx) foram verificadas. Resultados: Observamos um aumento da expressão do NF-kb e TNF-α;; no grupo LPVP, e aumento na expressão da iNOS avaliada por Western blot. A NAC reduziu a expressão de todas as proteínas avaliadas. Observamos um aumento do estresse oxidativo no intestino dos ratos do grupo LPVP com relação aos controles (SO), sendo a NAC eficaz na redução desses valores no grupo LPVP + NAC. Ainda, uma redução na atividade das enzimas SOD e GPx no grupo doente, sendo a NAC capaz de restaurar a atividade das enzimas avaliadas. Conclusão: Sugerimos a ação anti-inflamatória e antioxidante da NAC no intestino de animais submetidos ao modelo LPVP.

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El acetaminofén se ha convertido en el analgésico más ampliamente disponible alrededor del mundo. Aunque se considera muy seguro a dosis terapéuticas, la sobredosis puede conducir a necrosis hepática y es una de las causas principales de insuficiencia hepática aguda. La hepatitis inducida por acetaminofén es de inicio agudo, rápidamente progresiva y se caracteriza por una marcada elevación de las transaminasas. Las manifestaciones iniciales pueden ser leves e inespecíficas, por lo tanto, la medición de la concentración sérica del fármaco es crítica cuando existe sospecha de sobredosis. El nivel debe ser evaluado de acuerdo según el nomogramamodificado de Rumack-Matthew para determinar el uso de la N-acetilcisteína (NAC), un antídoto eficaz si se utiliza con prontitud.Este artículo proporciona una visión general de la fisiopatología, la presentación, el diagnóstico y presenta las opciones terapéuticas actuales disponibles para tratar esta condición.

Acetaminophen has become the most widely available analgesic around the world. Although it's considered remarkably safe at therapeutic doses, its overdose can lead to hepatic necrosis and its one of the principal causes of acute liver failure. Acetaminophen-induced hepatitis is acute in onset, progresses rapidly and is characterized by a marked elevation in aminotransferases. Initial manifestations may be mild and nonspecific, thus, measurement of serum acetaminophen concentration is critical when an overdose is suspected. The level should be evaluated according to the modified Rumack-Matthew nomogram to determine the use of N-acetylcystein (NAC), an effective antidote if used promptly.This article provides an overview of the pathophysiology, presentation, diagnosis of acetaminophen poisoning and presents the actual therapeutic options available to treat this condition.

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OBJECTIVE: To evaluate the safety and efficacy of N-acetylcysteine (NAC) orally on digital microcirculation blood flow in patients with Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc). METHODS: This was a randomized, double-blind, placebo-controlled trial in which 42 patients with SSc received oral NAC at a dose of 600mg tid (21 patients, mean age 45.6±9.5 years) or placebo (21 patients, mean age 45.0±12.7 years) for four weeks. The primary endpoint was the change in cutaneous microcirculation blood flow before and after cold stimulation measured by laser Doppler imaging (LDI) at weeks 0 and 4. The frequency and severity of RP and the number of digital ulcers were also measured at weeks 0 and 4. The adverse events were recorded in the fourth week. RESULTS: There was no significant change in digital blood flow assessed by LDI before or after cold stimulus after four weeks of NAC or placebo. Both groups showed significant improvement in the frequency and severity of RP attacks, with no difference between the two groups. At the end of the study, the placebo group had three digital ulcers, while the NAC group showed no ulcers. NAC was well tolerated and no patient discontinued the treatment. CONCLUSIONS: NAC orally at a dose of 1800mg/day showed no vasodilator effect on hands' microcirculation after four weeks of treatment in patients with RP secondary to SSc.

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Objetivo Avaliar a segurança e a eficácia da N-acetilcisteína (NAC) por via oral sobre o fluxo sanguíneo da microcirculação digital em pacientes com fenômeno de Raynaud (FRy) secundário à esclerose sistêmica (ES). Métodos Este foi um estudo randomizado, duplo-cego e placebo-controlado, no qual 42 pacientes com ES receberam NAC oral na dose de 600 mg, três vezes ao dia (21 pacientes, idade média 45,6±9,5 anos) ou placebo (21 pacientes, idade média 45,0±12,7 anos) durante quatro semanas. O desfecho primário do estudo foi: melhora no fluxo sanguíneo da microcirculação cutânea antes e após estímulo frio avaliado pelo laser Doppler imaging (LDI) nas semanas 0 e 4. A frequência e a gravidade do FRy e o número de úlceras digitais também foram avaliados nas semanas 0 e 4. Os efeitos adversos foram registrados na quarta semana. Resultados Não houve mudança significativa no fluxo sanguíneo digital avaliado pelo LDI antes ou depois do estímulo frio após quatro semanas de NAC ou placebo. Ambos os grupos apresentaram melhora significativa na frequência e gravidade dos ataques de FRy, sem diferença entre os dois. O grupo placebo apresentou três úlceras digitais enquanto o grupo NAC não apresentou úlceras ao final do estudo. NAC foi bem tolerada e nenhum paciente descontinuou o tratamento. Conclusões NAC por via oral na dose de 1.800mg/dia não demonstrou efeito vasodilatador sobre a microcirculação das mãos após quatro semanas de tratamento em pacientes com FRy secundário à ES. .

Objective To evaluate the safety and efficacy of oral N-acetylcysteine (NAC) on digital microcirculation blood flow in patients with Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc). Methods This was a randomized, double-blind, placebo-controlled trial in which 42 patients with SSc received oral NAC at a dose of 600mg tid (21 patients, mean age 45.6±9.5 years) or placebo (21 patients, mean age 45.0±12.7 years) for four weeks. The primary endpoint was the change in cutaneous microcirculation blood flow before and after cold stimulation measured by laser Doppler imaging (LDI) at weeks 0 and 4. The frequency and severity of RP and the number of digital ulcers were also measured at weeks 0 and 4. The adverse events were recorded in the fourth week. Results There was no significant change in digital blood flow assessed by LDI before or after cold stimulus after four weeks of NAC or placebo. Both groups showed significant improvement in the frequency and severity of RP attacks, with no difference between the two groups. At the end of the study, the placebo group had three digital ulcers, while the NAC group showed no ulcers. NAC was well tolerated and no patient discontinued the treatment. Conclusions NAC orally at a dose of 1800mg/day showed no vasodilator effect on hands’ microcirculation after four weeks of treatment in patients with RP secondary to SSc. .

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Se fabricaron nanopartículas de copolímero de ácido láctico y glicólico (PLGA) de tamaños inferiores a 200 nm que atraparan y transportaran N acetilcisteína (NAC) en futuras aplicaciones como sistema de liberación de fármacos. Para esto se eligió el método de emulsión sencilla con evaporación, empleándose acetato de etilo como solvente, Pluronic F127® como tensoactivo, ultrasonido como medio para generar la emulsión y agua. Se estudió el efecto de parámetros entre la fase orgánica y acuosa, amplitud y tiempo de sonicación. Se encontraron nanopartículas de 114 nm, estables coloidalmente y que atraparon un 15% de NAC. Las condiciones encontradas fueron: relación de fase orgánica a acuosa de 1 a 5, amplitud del 60% y 60 s como tiempo de ultrasonido.

Lactic and glycolic acid (PLGA) copolymer nanoparticles of less than 200 nm were produced to trap and transport N acetylcysteine (NAC) to be used in future applications, in the field of drug delivery systems. To do this, we selected the simple emulsion and evaporation method, using ethyl acetate as a solvent, Pluronic F127® as a surfactant, water and used ultrasound to generate the emulsion. The effect of the parameters during the organic to the aqueous phase was assessed as well as the amplitude and sonication. We found nanoparticles of 114 nm that trapped colloidally stable 15% NAC; the ratio of organic to the aqueous phase was 1 to 5, the amplitude 60% and the ultrasound period was 60 s.

Fabricaram-se nanopartículas e copolímero de ácido láctico e glicólico (PLGA) de tamanhos inferiores a 200 nm que capturaram e transportaram N acetilcisteína (NAC) em futuras aplicações como sistema de libertação de fármacos. Para isto se selecionou o método de emulsão simples com evaporação, empregando-se acetato de etilo como solvente, Pluronic F127® como tensioativos, ultrasons como meio para produzir a emulsão de água. Estudou-se o efeito de parâmetros entre a fase orgânica e aquosa, amplitude e tempo de sonicação. Encontraram-se nanoparticulas de 114nm, estáveis coloidamente e que capturaram cerca de 15% de NAC. As condições encontradas foram: relação da fase orgânica a aquosa de 1 a 5, amplitude de 60% e 60s como tempo de ultrasons.

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Objective: Severe hepatotoxicity caused by paracetamol is rare in neonates. We report a case of paracetamol-induced acute liver failure in a term neonate. Case description: A 26-day-old boy was admitted with intestinal bleeding, shock signs, slight liver enlargement, coagulopathy, metabolic acidosis (pH=7.21; bicarbonate: 7.1mEq/L), hypoglycemia (18mg/dL), increased serum aminotransferase activity (AST=4,039IU/L; ALT=1,087IU/L) and hyperbilirubinemia (total: 9.57mg/dL; direct: 6.18mg/dL) after receiving oral paracetamol (10mg/kg/dose every 4 hours) for three consecutive days (total dose around 180mg/kg; serum concentration 36-48 hours after the last dose of 77µg/ mL). Apart from supportive measures, the patient was successfully treated with intravenous N-acetylcysteine infusion during 11 consecutive days, and was discharged on day 34. The follow-up revealed full recovery of clinical and of laboratory findings of hepatic function. Comments: The paracetamol pharmacokinetics and pharmacodynamics in neonates and infants differ substantially from those in older children and adults. Despite the reduced rates of metabolism by the P-450 CYP2E1 enzyme system and the increased ability to synthesize glutathione - which provides greater resistance after overdoses -, it is possible to produce hepatotoxic metabolites (N-acetyl-p-benzoquinone) that cause hepatocellular damage, if glutathione sources are depleted. Paracetamol clearance is reduced and the half-life of elimination is prolonged. Therefore, a particular dosing regimen should be followed due to the toxicity risk of cumulative doses. This report highlights the risk for severe hepatotoxicity in neonates after paracetamol multiple doses for more than two to three days. .

Objetivo: La hepatotoxicidad grave inducida por el paracetamol es muy rara en neonatos. Se relata el caso de un neonato a término que desarrolló falencia hepática aguda después del uso de paracetamol. Descripción del caso: Niño, 26 días, admitido con sangrado intestinal, señales de choque, discreta hepatomegalia, coagulopatía, acidosis metabólica (pH=7,21; bicarbonato: 7,1mEq/L), hipoglucemia (18mg/dL), aumento de las aminotransferasas séricas (AST=4.039UI/L; ALT=1.087UI/L) e hiperbilirrubinemia (total: 9,75mg/dL; directa: 6,18mg/dL), después del uso de paracetamol por vía oral (10mg/kg/dosis a cada cuatro horas) durante tres días consecutivos (dosis alrededor de 180mg/kg; nivel sérico de 36-48 horas después de la última dosis de 77µg/mL). Además de las medidas de soporte, el paciente fue tratado con N-acetilcisteína (infusión intravenosa continua por 11 días consecutivos), recibiendo alta después de 34 días de internación. El seguimiento mostró recuperación clínica y de los parámetros laboratoriales de la función hepática. Comentarios : La farmacocinética y la farmacodinámica del paracetamol en neonatos y lactantes jóvenes (menores de un año) difieren substancialmente de niños más grandes y adultos. A pesar de que las tasas de metabolismo del sistema enzimático P-450 CYP2E1 están reducidas y la capacidad de generar glutatión, aumentada - confiriendo más protección después de superdosis -, existe la posibilidad de producción de metabólitos hepatotóxicos (N-acetil-pbenzoquinoneimina) que determinan lisis celular, caso se agoten las reservas de glutatión. La depuración es reducida y la media vida de la eliminación, alargada, recomendándose posología distinta por el riesgo de toxicidad ...

Objetivo: A hepatoxicidade grave induzida pelo paracetamol é muito rara em neonatos. Relata-se o caso de um neonato de termo que desenvolveu falência hepática aguda após o uso de paracetamol. Descrição do caso: Menino, 26 dias, admitido com sangramento intestinal, sinais de choque, discreta hepatomegalia, coagulopatia, acidose metabólica (pH=7,21; bicarbonato: 7,1mEq/L), hipoglicemia (18mg/dL), aumento das aminotransferases séricas (AST=4.039UI/L; ALT=1.087UI/L) e hiperbilirrubinemia (total: 9,57mg/dL; direta: 6,18mg/dL), após uso de paracetamol via oral (10mg/kg/dose a cada quatro horas) por três dias consecutivos (dose total ao redor de 180mg/kg; nível sérico de 36-48 horas após a última dose de 77µg/mL). Além das medidas de suporte, o paciente foi tratado com N-acetilcisteína (infusão intravenosa contínua por 11 dias consecutivos), recebendo alta após 34 dias de internação. O seguimento mostrou recuperação clínica e dos parâmetros laboratoriais da função hepática. Comentários: A farmacocinética e a farmacodinâmica do paracetamol em neonatos e lactentes jovens (menores de um ano) diferem substancialmente de crianças maiores e adultos. Apesar de as taxas de metabolismo do sistema enzimático P-450 CYP2E1 estarem diminuídas e a capacidade de gerar glutationa, aumentadas - conferindo maior proteção após superdosagens -, existe a possibilidade de produção de metabólitos hepatotóxicos (N-acetil-p-benzoquinoneimina) que determinam lise celular, caso se esgotem as reservas de glutationa. A depuração é diminuída e a meia-vida de eliminação é prolongada, recomendando-se posologia distinta pelo risco de toxicidade de doses cumulativas. O presente relato destaca o risco de hepatotoxicidade grave ...

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JUSTIFICATIVA E OBJETIVOS: Mecanismos patogênicos desencadeados pelo Plasmodium berghei sugerem que suplementação prévia com antioxidantes possa exercer papel preventivo ao estabelecimento da malária. O objetivo deste estudo foi estudar os efeitos de suplementos antioxidantes sobre o estresse oxidativo cerebral e pulmonar e sobre a sobrevida de camundongos infectados. MÉTODOS: Estudo experimental que utilizou camundongos divididos em 3 grupos de 10 animais cada. O grupo I correspondeu ao grupo controle positivo, o grupo II foi formado por animais tratados com N-acetilcisteína e o grupo III com Agaricus sylvaticus.Observou-se a sobrevida e coletaram-se amostras de tecido pulmonar e cerebral no dia de óbito de cada animal. Avaliou-se a parasitemia,os níveis de malondialdeído e a capacidade antioxidante equivalente ao trolox. RESULTADOS: Não se encontrou relação significativa entre a administração prévia de Agaricus sylvaticus e N-acetilcisteína e o tempo de sobrevida ou sobre a parasitemia dos animais infectados. Entretanto, níveis de malondialdeído no cérebro dos animais do grupo controle foram significantemente maiores (p<0,0001) que do N-acetilcisteína e Agaricus sylvaticus, sendo os valores do N-acetilcisteína menores que do Agaricus sylvaticus.Para capacidade antioxidante equivalente ao trolox cerebral, o grupo N-acetilcisteína apresentou valores significantemente maiores (p<0,05) que o Agaricus sylvaticus. Encontrou-se moderada correlação negativa (r=-0,73; p=0,02) entre malondialdeído cerebral e sobrevida. CONCLUSÃO: Estes dados sugerem que, apesar do nível de estresse oxidativo apresentar correlação negativa com a sobrevida dos animais, o uso de suplementos antioxidantes não promoveu aumento na expectativa de vida dos animais suplementados. Isto pode ter decorrido das doses utilizadas de antioxidantes ou das substâncias empregadas.

BACKGROUND AND OBJECTIVES: Pathogenic mechanisms triggered by Plasmodium berghei suggest that prior supplementation with antioxidants may have a preventive role in the onset of malaria. The objective of this study was to study the effects of antioxidant supplements on brain and pulmonary oxidative stress and on the survival of infected mice. METHODS: An experimental study using mice, which were divided into 3 groups of 10 animals each. Group I corresponded to the positive control group, group II was formed by animals treated with N-acetylcysteine and group III with Agaricus sylvaticus. Survival was observed and samples of lung and brain tissues were collected on the day of death of each animal. Parasitemia, the levels of malondialdehyde, and antioxidant capacity equivalent to trolox were evaluated. RESULTS: There was no significant relationship between prior administration of Agaricus sylvaticus or N-acetylcysteine and the survival or parasitemia of infected animals. However, levels of malondialdehyde in the brain of animals from control group were significantly higher (p <0.0001) than those of N-acetylcysteine and Agaricus sylvaticus, and values from of N-acetylcysteine were lower than of Agaricus sylvaticus. For brain antioxidant capacity equivalent to trolox, N-acetylcysteine group showed significantly higher values (p < 0.05) than Agaricus sylvaticus. A mild negative correlation (p = 0.02 and R = -0.73) between brain malondialdehyde and survival was found. CONCLUSION: These data suggest that, although the levels of oxidative stress presented negative correlation with animals survival, the use of antioxidant supplements did not provide an increase in life expectancy of supplemented animals. This may have occurred due to the doses of antioxidants or of substances used.

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INTRODUCTION: Staphylococcus epidermidis is an organism commonly associated with infections caused by biofilms. Biofilms are less sensible to antibiotics and therefore are more difficult to eradicate. Linezolid and N-acetylcysteine (NAC), have demonstrated to be active against gram-positive microorganisms. Therefore and since linezolid and NAC have different modes of action, the main objective of this work was to investigate the single and synergistic effect of linezolid and NAC against S. epidermidis biofilms. METHODS: This work reports the in vitro effect of linezolid and NAC against S. epidermidis biofilms, treated with MIC (4mgml(-1)) and 10×MIC of NAC, and MIC (1µgml(-1)) and peak serum concentration (PS=18µgml(-1)) of linezolid alone and in combination. After exposure of S. epidermidis biofilms to linezolid and/or NAC for 24h, several biofilm parameters were evaluated, namely the number of cultivable cells [colony forming unit (CFU) enumeration], total biofilm biomass and cellular activity. RESULTS: When tested alone, NAC at 10×MIC was the most effective agent against S. epidermidis biofilms. However, the combination linezolid (MIC)+NAC (10×MIC) showed a synergistic effect and was the most biocidal treatment tested, promoting a 5log reduction in the number of biofilm viable cells. CONCLUSION: This combination seems to be a potential candidate to combat infections caused by S. epidermidis biofilms, namely as a catheter lock solution therapy.

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