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Article in Chinese | WPRIM | ID: wpr-936351


OBJECTIVE@#To explore the effect of inhibiting polyribonucleotide nucleotidyl-transferase 1 (PNPT1) on oxygen-glucose deprivation (OGD)-induced apoptosis of mouse atrial myocytes.@*METHODS@#Cultured mouse atrial myocytes (HL-1 cells) with or without OGD were transfected with PNPT1-siRNA or a negative control siRNA (NC-siRNA group), and the cell survival rate was detected using CCK-8 assay. The expression levels of ACTB and TUBA mRNA were detected with qPCR, and the protein expression of PNPT1 was detected with Western blotting. The apoptosis rate of the treated cells was determined with flow cytometry, the mitochondrial membrane potential was detected using JC-1 kit, and the mitochondrial morphology was observed using transmission electron microscope.@*RESULTS@#With the extension of OGD time, the protein expression levels of PNPT1 increased progressively in the cytoplasm of HL-1 cells (P < 0.05). Transfection with PNPT1-siRNA significantly reduced PNPT1 expression in HL-1 cells (P < 0.05). Exposure to OGD significantly enhanced degradation of ACTB and TUBA mRNA (P < 0.05) and markedly increased the apoptosis rate of HL-1 cells (P < 0.05), and these changes were significantly inhibited by transfection with PNPT1-siRNA (P < 0.05), which obviously increased mitochondrial membrane potential and improved mitochondrial morphology of HL-1 cells exposed to OGD.@*CONCLUSION@#Inhibition of PNPT1 improves mitochondrial damage and reduces degradation of apoptotic-associated mRNAs to alleviate OGD-induced apoptosis of mouse atrial myocyte.

Animals , Mice , Apoptosis , Cell Survival , Glucose/pharmacology , Myocytes, Cardiac , Oxygen/metabolism , RNA, Messenger/metabolism , RNA, Small Interfering/metabolism
Electron. j. biotechnol ; 52: 35-44, July. 2021. tab, ilus
Article in English | LILACS | ID: biblio-1283494


BACKGROUND: Alginates are polysaccharides used in a wide range of industrial applications, with their functional properties depending on their molecular weight. In this study, alginate production and the expression of genes involved in polymerization and depolymerization in batch cultures of Azotobacter vinelandii were evaluated under controlled and noncontrolled oxygen transfer rate (OTR) conditions. RESULTS: Using an oxygen transfer rate (OTR) control system, a constant OTR (20.3 ± 1.3 mmol L 1 h 1 ) was maintained during cell growth and stationary phases. In cultures subjected to a controlled OTR, alginate concentrations were higher (5.5 ± 0.2 g L 1 ) than in cultures under noncontrolled OTR. The molecular weight of alginate decreased from 475 to 325 kDa at the beginning of the growth phase and remained constant until the end of the cultivation period. The expression level of alyA1, which encodes an alginate lyase, was more affected by OTR control than those of other genes involved in alginate biosynthesis. The decrease in alginate molecular weight can be explained by a higher relative expression level of alyA1 under the controlled OTR condition. CONCLUSIONS: This report describes the first time that alginate production and alginate lyase (alyA1) expression levels have been evaluated in A. vinelandii cultures subjected to a controlled OTR. The results show that automatic control of OTR may be a suitable strategy for improving alginate production while maintaining a constant molecular weight.

Polysaccharide-Lyases/metabolism , Oxygen Transfer , Azotobacter vinelandii/metabolism , Oxygen/metabolism , Gene Expression , Polymerase Chain Reaction , Azotobacter vinelandii/genetics , Alginates/metabolism , Fermentation , Molecular Weight
Article in English | WPRIM | ID: wpr-879951


:To investigate the effect of transient receptor potential melastatin 2 (TRPM2) inhibitor A10 on oxygen glucose deprivation/reperfusion (OGD/R) injury in SH-SY5Y cells.:Human neuroblastoma SH-SY5Y cells were subject to OGD/R injury,and then were divided into blank control group,model control group and A10 group randomly. The cell survival rate was detected by cell counting kit 8 (CCK-8); the level of cellular reactive oxygen species (ROS) was detected by reactive oxygen detection kit; the mitochondrial membrane potential was detected by tetramethylrhodamine (TMRM) method; the number of apoptotic cells was detected by TUNEL apoptosis assay kit; the protein expression level of cleaved caspase 3 was detected by Western blot.:Compared with 3,20,30,50, has lower cytotoxicity and better inhibition effect on channel activity. Compared with the model control group,ROS level was reduced,the mitochondrial membrane potential was improved,the number of apoptosis cells was reduced ,and the expression of cleaved caspase 3 was significantly reduced in the A10 group(all <0.05). : A10 can alleviate cell damage after OGD/R by inhibiting TRPM2 channel function,reducing extracellular calcium influx,reducing cell ROS levels,stabilizing mitochondrial membrane potential levels,and reducing apoptosis.

Humans , Apoptosis , Benzeneacetamides , Cell Survival , Glucose , Oxygen/metabolism , Piperidones , Reactive Oxygen Species/metabolism , Reperfusion , TRPM Cation Channels
Rev. bras. ter. intensiva ; 32(1): 115-122, jan.-mar. 2020. graf
Article in English, Portuguese | LILACS | ID: biblio-1138462


RESUMO A proporção entre pressão venosa central menos arterial de dióxido de carbono e conteúdo de oxigênio arterial menos venoso central (Pcv-aCO2/Ca-cvO2) foi proposta como marcador substituto para quociente respiratório e indicador de oxigenação tissular. Alguns pequenos estudos observacionais identificaram que Pcv-aCO2/Ca-cvO2 acima de 1,4 se associa com hiperlactatemia, dependência de suprimento de oxigênio e maior mortalidade. Mais ainda, a Pcv-aCO2/Ca-cvO2 foi incorporada a algoritmos para avaliação da oxigenação tissular e ressuscitação. Contudo, a evidência para estas recomendações é bastante limitada e de baixa qualidade. O objetivo desta revisão narrativa foi analisar as bases metodológicas, os fundamentos fisiopatológicos e a evidência experimental e clínica para dar suporte à utilização da Pcv-aCO2/Ca-cvO2 como marcador substituto para quociente respiratório. De um ponto de vista fisiopatológico, o aumento do quociente respiratório secundariamente a reduções críticas no transporte de oxigênio é um evento dramático e com risco à vida. Entretanto, este evento é facilmente observável e provavelmente não demandaria maiores monitoramentos. Visto que o início do metabolismo anaeróbico é indicado pelo aumento súbito do quociente respiratório e que a faixa normal do quociente respiratório é ampla, o uso do ponto de corte definido como 1,4 para Pcv-aCO2/Ca-cvO2 não faz sentido. Estudos experimentais demonstraram que a Pcv-aCO2/Ca-cvO2 é mais dependente de fatores que modificam a dissociação do dióxido de carbono da hemoglobina do que do quociente respiratório, e o quociente respiratório e Pcv-aCO2/Ca-cvO2 podem ter comportamentos distintos. Estudos conduzidos em pacientes críticos demonstraram resultados controvertidos com relação à capacidade da Pcv-aCO2/Ca-cvO2 para predizer o desfecho, hiperlactatemia, anomalias microvasculares e dependência de suprimento de oxigênio. Um estudo randomizado controlado também demonstrou que a Pcv-aCO2/Ca-cvO2 é inútil como alvo para ressuscitação. A Pcv-aCO2/Ca-cvO2 deve ser interpretada com cautela em pacientes críticos.

ABSTRACT The central venous minus arterial carbon dioxide pressure to arterial minus central venous oxygen content ratio (Pcv-aCO2/Ca-cvO2) has been proposed as a surrogate for respiratory quotient and an indicator of tissue oxygenation. Some small observational studies have found that a Pcv-aCO2/Ca-cvO2 > 1.4 was associated with hyperlactatemia, oxygen supply dependency, and increased mortality. Moreover, Pcv-aCO2/Ca-cvO2 has been incorporated into algorithms for tissue oxygenation evaluation and resuscitation. However, the evidence for these recommendations is quite limited and of low quality. The goal of this narrative review was to analyze the methodological bases, the pathophysiologic foundations, and the experimental and clinical evidence supporting the use of Pcv-aCO2/Ca-cvO2 as a surrogate for respiratory quotient. Physiologically, the increase in respiratory quotient secondary to critical reductions in oxygen transport is a life-threatening and dramatic event. Nevertheless, this event is easily noticeable and probably does not require further monitoring. Since the beginning of anaerobic metabolism is indicated by the sudden increase in respiratory quotient and the normal range of respiratory quotient is wide, the use of a defined cutoff of 1.4 for Pcv-aCO2/Ca-cvO2 is meaningless. Experimental studies have shown that Pcv-aCO2/Ca-cvO2 is more dependent on factors that modify the dissociation of carbon dioxide from hemoglobin than on respiratory quotient and that respiratory quotient and Pcv-aCO2/Ca-cvO2 may have distinct behaviors. Studies performed in critically ill patients have shown controversial results regarding the ability of Pcv-aCO2/Ca-cvO2 to predict outcome, hyperlactatemia, microvascular abnormalities, and oxygen supply dependency. A randomized controlled trial also showed that Pcv-aCO2/Ca-cvO2 is useless as a goal of resuscitation. Pcv-aCO2/Ca-cvO2 should be carefully interpreted in critically ill patients.

Humans , Oxygen/metabolism , Arteries , Veins , Carbon Dioxide/blood , Pressure , Blood Gas Analysis
Arq. bras. cardiol ; 114(2): 209-218, Feb. 2020. tab, graf
Article in English | LILACS | ID: biblio-1088870


Abstract Background: Atrial fibrillation (AF) is associated with increased mortality in heart failure (HF) patients. Objective: To evaluate whether the risk of AF patients can be precisely stratified by relation with cardiopulmonary exercise test (CPET) cut-offs for heart transplantation (HT) selection. Methods: Prospective evaluation of 274 consecutive HF patients with left ventricular ejection fraction ≤ 40%. The primary endpoint was a composite of cardiac death or urgent HT in 1-year follow-up. The primary endpoint was analysed by several CPET parameters for the highest area under the curve and for positive (PPV) and negative predictive value (NPV) in AF and sinus rhythm (SR) patients to detect if the current cut-offs for HT selection can precisely stratify the AF group. Statistical differences with a p-value <0.05 were considered significant. Results: There were 51 patients in the AF group and 223 in the SR group. The primary outcome was higher in the AF group (17.6% vs 8.1%, p = 0.038). The cut-off value of pVO2 for HT selection showed a PPV of 100% and an NPV of 95.5% for the primary outcome in the AF group, with a PPV of 38.5% and an NPV of 94.3% in the SR group. The cut-off value of VE/VCO2 slope showed lower values of PPV (33.3%) and similar NPV (92.3%) to pVO2 results in the AF group. Conclusion: Despite the fact that AF carries a worse prognosis for HF patients, the current cut-off of pVO2 for HT selection can precisely stratify this high-risk group.

Resumo Fundamento: A fibrilação atrial (FA) está associada ao aumento da mortalidade em pacientes com insuficiência cardíaca (IC). Objetivo: Avaliar se o risco de pacientes com FA pode ser estratificado com precisão em relação aos pontos de corte do teste de esforço cardiopulmonar (TECP) para seleção do transplante cardíaco (TC). Métodos: Avaliação prospectiva de 274 pacientes consecutivos com IC com fração de ejeção do ventrículo esquerdo ≤ 40%. O endpoint primário foi um composto de morte cardíaca ou TC urgente no seguimento de 1 ano. O endpoint primário foi analisado através de vários parâmetros do TECP para a maior área sob a curva e para o valor preditivo positivo (VPP) e negativo (VPN) em pacientes com FA e ritmo sinusal (RS) para detectar se os atuais pontos de corte para a seleção de TC podem estratificar com precisão o grupo com FA. Diferenças estatísticas com valor de p < 0,05 foram consideradas significativas. Resultados: Havia 51 pacientes no grupo de FA e 223 no grupo RS. O endpoint primário foi maior no grupo FA (17,6% vs. 8,1%, p = 0,038). O valor de corte de pVO2 para a seleção do TC mostrou um VPP de 100% e um VPN de 95,5% para o endpoint primário no grupo FA, com um VPP de 38,5% e um VPN de 94,3% no grupo RS. O valor de corte da inclinação VE/VCO2 apresentou valores mais baixos de VPP (33,3%) e valor semelhante de VPN (92,3%) aos resultados de pVO2 no grupo FA. Conclusões: Apesar do fato de a FA apresentar um pior prognóstico para os pacientes com IC, o atual ponto de corte de pVO2 para a seleção de TC pode estratificar com precisão esse grupo de alto risco.

Humans , Male , Female , Adult , Middle Aged , Aged , Atrial Fibrillation/physiopathology , Atrial Fibrillation/mortality , Risk Assessment/standards , Exercise Test/standards , Heart Failure/physiopathology , Oxygen/metabolism , Oxygen Consumption/physiology , Prognosis , Reference Standards , Stroke Volume/physiology , Time Factors , Proportional Hazards Models , Multivariate Analysis , Prospective Studies , Risk Factors , Follow-Up Studies , Statistics, Nonparametric , Exercise Test/methods , Heart Failure/mortality
Einstein (Säo Paulo) ; 18: eAO5256, 2020. tab, graf
Article in English | LILACS | ID: biblio-1090048


ABSTRACT Objective To describe and identify the importance of different indicators of the aerobic and anaerobic fitness of male ultra-trail runners according to their level of participation (regional or national). Methods Forty-four male ultra-trail runners were assessed (36.5±7.2 years). They were classified as regional (n=25) and national (n=19). Wingate test was used to assess the anaerobic pathway. A progressive incremental running test was performed and ventilatory thresholds registered, in parallel to heart rate and lactate concentration at the end of the protocol. Comparison between groups was performed using independent samples t-test. Results No significant differences were found between outputs derived from Wingate test. For aerobic fitness, while examining absolute values, differences were uniquely significant for the second ventilatory threshold (ultra-trail regional runners: 3.78±0.32L.min-1; ultra-trail national runners: 4.03±0.40L.min-1 p<0.05). Meantime, when aerobic fitness was expressed per unit of body mass, differences were significant for the second ventilatory threshold (ultra-trail regional runners: 50.75±; ultra-trail national runners: 57.88± p<0.05) and also maximum volume of oxygen (ultra-trail regional runners: 57.33±; ultra-trail national runners: 63.39± p<0.05). Conclusion This study emphasized the importance of expressing physiological variables derived from running protocols per unit of body mass. Also, the second ventilatory threshold appears to be the best and the only aerobic fitness variable to distinguish between trail runners according to competitive level. Maximal oxygen uptake seems of relative interest to distinguish between long distance runners according to competitive level.

RESUMO Objetivo Descrever e comparar indicadores de aptidão metabólica em corredores de trilhas de longa distância (ultra trail running) adultos do sexo masculino, de acordo com o nível de competição (regional ou nacional). Métodos Foram avaliados 44 corredores masculinos com média de idade de 36,5±7,2 anos classificados como de nível regional (n=25) ou nacional (n=19). Foi utilizado o teste de Wingate para avaliação da via anaeróbica, enquanto o teste incremental de corrida em esteira também foi realizado para determinar os limiares ventilatórios, o consumo máximo de oxigênio, a frequência cardíaca e a concentração de lactato ao final do protocolo. A comparação entre os grupos foi realizada por estatística teste t para amostras independentes. Resultados As variáveis obtidas do teste Wingate não diferiram de forma significativa entre os grupos. No que diz respeito à aptidão aeróbica, foram encontradas diferenças significativas entre variáveis expressas em valores absolutos no segundo limiar ventilatório (corredores de nível regional: 3,78±0,32L.min-1; corredores de nível nacional: 4,03±0,40L.min-1; p<0,05). Quando considerados os valores expressos por unidade de massa corporal, o segundo limiar ventilatório (corredores de nível regional: 50,75±6,; corredores de nível nacional: 57,88±4,; p<0,05) e o volume máximo de oxigênio (corredores de nível regional: 57,33±7,; corredores de nível nacional: 63,39±4,; p<0,05) também diferiram de forma significativa. Conclusão Este estudo destacou a importância de se expressarem variáveis fisiológicas derivadas de protocolos de corrida por unidade de massa corporal. Além disso, o segundo limiar ventilatório pareceu ser o melhor e único indicador de aptidão aeróbica para a diferenciação de corredores de trilha de longa distância, segundo o nível competitivo. O consumo máximo de oxigênio não é especialmente relevante para distinguir os corredores de trilha de longa distância, segundo o nível competitivo.

Humans , Male , Adult , Running/physiology , Athletes , Oxygen/metabolism , Reference Values , Time Factors , Anaerobic Threshold/physiology , Body Mass Index , Cross-Sectional Studies , Statistics, Nonparametric , Exercise Test/methods , Heart Rate/physiology
Rev. bras. anestesiol ; 69(6): 553-560, nov.-Dec. 2019. tab, graf
Article in English | LILACS | ID: biblio-1057477


Abstract Background and objectives: The aim of this study was to investigate the efficacy of the pressure-controlled, volume-guaranteed (PCV-VG) and volume-controlled ventilation (VCV) modes for maintaining adequate airway pressures, lung compliance and oxygenation in obese patients undergoing laparoscopic hysterectomy in the Trendelenburg position. Methods: Patients (104) who underwent laparoscopic gynecologic surgery with a body mass index between 30 and 40 kg.m-2 were randomized to receive either VCV or PCV-VG ventilation. The tidal volume was set at 8, with an inspired oxygen concentration of 0.4 with a Positive End-Expiratory Pressure (PEEP) of 5 mmHg. The peak inspiratory pressure, mean inspiratory pressure, plateau pressure, driving pressure, dynamic compliance, respiratory rate, exhaled tidal volume, etCO2, arterial blood gas analysis, heart rate and mean arterial pressure at 5 minutes after induction of anesthesia in the and at 5, 30 and 60 minutes, respectively, after pneumoperitoneum in the Trendelenburg position were recorded. Results: The PCV-VG group had significantly decreased peak inspiratory pressure, mean inspiratory pressur, plateau pressure, driving pressure and increased dynamic compliance compared to the VCV group. Mean PaO2 levels were significantly higher in the PCV-VG group than in the VCV group at every time point after pneumoperitoneum in the Trendelenburg position. Conclusions: The PCV-VG mode of ventilation limited the peak inspiratory pressure, decreased the driving pressure and increased the dynamic compliance compared to VCV in obese patients undergoing laparoscopic hysterectomy. PCV-VG may be a preferable modality to prevent barotrauma during laparoscopic surgeries in obese patients.

Resumo Justificativa e objetivos: O objetivo deste estudo foi investigar a eficácia dos modos de ventilação garantida por volume controlado por pressão (PCV-VG) e ventilação controlada por volume (VCV) para manter pressões adequadas nas vias aéreas, complacência pulmonar e oxigenação em pacientes obesos submetidos à histerectomia laparoscópica na posição de Trendelenburg. Métodos: Cento e quatro pacientes submetidos à cirurgia ginecológica laparoscópica, com índice de massa corporal entre 30 e 40 kg.m-2, foram randomizados para receber ventilação com VCV ou PCV-VG. O volume corrente foi fixado em 8, com uma concentração inspirada de oxigênio de 0,4 e pressão positiva expiratória final (PEEP) de 5 mmHg. Registramos os seguintes parâmetros: pressão de pico inspiratório, pressão inspiratória média, pressão de platô, driving pressure, complacência dinâmica, frequência respiratória, volume corrente expirado, etCO2, gasometria arterial, frequência cardíaca e pressão arterial média aos 5, 30 e 60 minutos, respectivamente, após o pneumoperitônio na posição de Trendelenburg. Resultados: O grupo PCV-VG apresentou uma redução significativa da pressão de pico inspiratório, pressão inspiratória média, pressão de platô, driving pressure e aumento da complacência dinâmica comparado ao grupo VCV. Os níveis médios de PaO2 foram significativamente maiores no grupo PCV-VG do que no grupo VCV em todos os momentos após o pneumoperitônio na posição de Trendelenburg. Conclusões: O modo de ventilação PCV-VG limitou a pressão de pico inspiratório, diminuiu a driving pressure e aumentou a complacência dinâmica, comparado ao VCV em pacientes obesas submetidas à histerectomia laparoscópica. O PCV-VG pode ser uma modalidade preferida para prevenir o barotrauma durante cirurgias laparoscópicas em pacientes obesos.

Humans , Female , Adult , Gynecologic Surgical Procedures/methods , Laparoscopy/methods , Head-Down Tilt , Obesity/complications , Oxygen/metabolism , Respiration, Artificial/methods , Tidal Volume/physiology , Lung Compliance/physiology , Prospective Studies , Positive-Pressure Respiration , Middle Aged
Arq. bras. cardiol ; 113(2): 188-194, Aug. 2019. tab, graf
Article in English | LILACS | ID: biblio-1019397


Abstract Background: Left ventricular global longitudinal strain value (GLS) can predict functional capacity in patients with preserved left ventricular ejection fraction (LVEF) heart failure (HF) and to assess prognosis in reduced LVEF HF. Objetive: Correlate GLS with parameters of Cardiopulmonary Exercise Test (CPET) and to assess if they could predict systolic HF patients that are more appropriated to be referred to heart transplantation according to CPET criteria. Methods: Systolic HF patients with LVEF < 45%, NYHA functional class II and III, underwent prospectively CPET and echocardiography with strain analysis. LVEF and GLS were correlated with the following CPET variables: maxVO2, VE/VCO2 slope, heart rate reduction during the first minute of recovery (HRR) and time needed to reduce maxVO2 in 50% after physical exercise (T1/2VO2). ROC curve analysis of GLS to predict VO2 < 14 mL/kg/min and VE/VCO2 slope > 35 (heart transplantation's criteria) was performed. Results: Twenty six patients were selected (age, 47 ± 12 years, 58% men, mean LVEF = 28 ± 8%). LVEF correlated only with maxVO2 and T1/2VO2. GLS correlated to all CPET variables (maxVO2: r = 0.671, p = 0.001; VE/VCO2 slope: r = -0.513, p = 0.007; HRR: r = 0.466, p = 0.016, and T1/2VO2: r = -0.696, p = 0.001). GLS area under the ROC curve to predict heart transplantation's criteria was 0.88 (sensitivity 75%, specificity 83%) for a cut-off value of -5.7%, p = 0.03. Conclusion: GLS was significantly associated with all functional CPET parameters. It could classify HF patients according to the functional capacity and may stratify which patients have a poor prognosis and therefore to deserve more differentiated treatment, such as heart transplantation.

Resumo Fundamento: O strain longitudinal global (SLG) é capaz de predizer a capacidade funcional dos pacientes com insuficiência cardíaca (IC) e fração de ejeção do ventrículo esquerdo (FEVE) preservada, e avaliar o prognóstico na IC com FEVE reduzida. Objetivo: Correlacionar o SLG com parâmetros do teste de exercício cardiopulmonar (TECP), e avaliar se o SLG seria capaz de predizer quais pacientes com IC sistólica deveriam ser encaminhados ao transplante cardíaco de acordo com os critérios do TECP. Métodos: Os pacientes com IC sistólica com FEVE <45%, classe funcional NYHA II e III, submeteram-se prospectivamente ao TECP e à ecocardiografia com análise do strain. A FEVE e o SLG foram correlacionados com as seguintes variáveis do TECP: maxVO2, inclinação de VE/VCO2, redução da frequência cardíaca durante o primeiro minuto de recuperação (RFC), e tempo necessário para a redução do maxVO2 em 50% após o exercício físico (T1/2VO2). Foi realizada análise da curva ROC do SLG em predizer um VO2 < 14 mL/kg/min e uma inclinação de VE/VCO2 > 35 (critérios para transplante cardíaco). O nível de significância adotado na análise estatística foi de p < 0,05. Resultados: Vinte e seis pacientes foram selecionados para o estudo (idade, 47±12 anos, 58% homens, FEVE média LVEF = 28 ± 8%). A FEVE correlacionou-se somente com o maxVO2 e o T1/2VO2. O SLG correlacionou-se com todas as variáveis do TECP (maxVO2: r = 0,671; p = 0,001; inclinação de VE/VCO2: r = -0,513; p = 0,007; RFC: r = 0,466; p = 0,016; e T1/2VO2: r = -0,696, p = 0,001). A área sob a curva ROC para o SLG para predizer os critérios para transplante cardíaco foi de 0,88 (sensibilidade 75%, especificidade 83%) para um ponto de corte de -5,7%, p = 0,03. Conclusão: O SLG apresentou associação significativa com todos os parâmetros funcionais do TECP. O SLG foi capaz de classificar os pacientes com IC segundo capacidade funcional e possivelmente pode identificar quais pacientes têm um prognóstico ruim e, portanto, se beneficiariam de um tratamento diferenciado, tal como o transplante cardíaco.

Humans , Male , Female , Adult , Middle Aged , Exercise/physiology , Ventricular Dysfunction, Left/physiopathology , Exercise Test/methods , Heart Failure, Systolic/physiopathology , Oxygen/metabolism , Oxygen Consumption/physiology , Prognosis , Reference Values , Stroke Volume/physiology , Time Factors , Echocardiography/methods , Cross-Sectional Studies , Risk Factors , ROC Curve , Heart Transplantation , Statistics, Nonparametric , Risk Assessment , Heart Rate/physiology
Rev. chil. pediatr ; 90(3): 309-315, jun. 2019. tab, graf
Article in Spanish | LILACS | ID: biblio-1013838


INTRODUCCIÓN: El diagnóstico precoz de los Trastornos Respiratorios del Sueño (TRS) puede permitir una intervención oportuna. La poligrafía (PG) es una alternativa confiable y accesible en la actualidad. OBJETIVO: Describir y analizar PG de niños > 1 año con sospecha de TRS. PACIENTES Y MÉTODO: Se incluyeron PG de niños y adolescentes > 1 año de edad con sospecha de TRS, desde diciembre de 2011 hasta agosto de 2017 provenientes de la ciudad de Concepcion, Chile. Se recopilaron datos demo gráficos, clínicos y variables poligráficas. Estadística descriptiva, expresando resultados en mediana y rango. Se determinó asociación entre índice de apnea hipopnea (IAH) y saturación mediante Rho de Spearman; considerando significancia p < 0,05. RESULTADOS: Se analizaron 190 estudios. Edad 7,9 años (1,0-20,6), varones 61%. Diagnósticos: enfermedades neuromusculares (ENM) (24,2%), daño pulmonar crónico (21,1%), obstrucción de vía aérea superior (OVAS) (19,5%), daño neurológico (11%), síndrome de Down (8,9%) malformaciones VAS (7,4%), hipoventilación central (3,7%), obesidad (2,6%) y otros (1,6%). El 55,3% de las PG resultaron alteradas; síndrome de apnea hipopnea obstructiva del sueño (SAHOS) leve en 53,3%, moderado 30,5% y severo 16,2%. No se observaron diferencias significativas en IAH entre grupos de patologías (p = 0,032), destacando un mayor IAH en Obesidad 9,0 (0,41-51) y ENM 23,9 (0,4-36,6). Se constató asociación entre IAH y parámetros de saturación; saturación promedio (rho = -0,425; p = 0,001); mínima (rho = -0,654; p = 0,001); y saturación bajo 90% (rho = 0,323; p = 0,001) en la totalidad de la muestra. DISCUSIÓN: Existió un alto porcentaje de SAHOS en pacientes pediátricos de riesgo, en especial en aquellos con ENM y obesidad. La PG es una herramienta accesible e implementable en un hospital público; situación potencialmente extrapolable a otros centros asistenciales.

INTRODUCTION: The early diagnosis of Sleep Disordered Breathing (SDB) may allow proper intervention. Currently, polygraphy (PG) is a reliable and accessible alternative. OBJECTIVE: To describe and analyze the PG of children > 1 year old with suspicion of SDB. PATIENTS AND METHOD: PG of children > 1 year old and adolescents from Concepcion, Chile, with suspected SDB were included, from December 2011 to August 2017. Demographic, clinical and polygraphic variables were collected. It was used descriptive sta tistics, expressing results in median and range. The association between apnea-hypopnea index (AHI) and oxygen saturation was determined by Spearman's Rho, considering significance of p < 0.05. RESULTS: 190 studies were analyzed. Age 7.9 years old (1.0-20.6), 61% males. Diagnosis: neuromuscular disease (NMD) (24.2%), chronic lung damage (21.1%), upper airway obstruction (UAO) (19.5%), neurological damage (11%), Down syndrome (8.9%), upper airway malformations (7.4%), central hypoventilation (3.7%), obesity (2.6%), and others (1.6%). 55.3% were altered PG, with 53.3% of mild Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS), 30.5% moderate, and 16.2% severe. There were no significant differences in AHI between groups of pathologies (p = 0.032), highlighting a higher AHI in obese patients 9 (0.41-51), and those with NMD 23.9 (0.4-36.6). It was found asso ciation between AHI and oxygen saturation parameters: mean saturation (rho = -0.425; p = 0.001), minimum (rho = -0.654; p = 0.001), and oxygen saturation below 90% (rho = 0.323; p = 0.001) in the whole sample. DISCUSSION: There was a high percentage of OSAHS in at-risk pediatric patients, especially in those with NMD and obesity. PG is an accessible and implementable tool in a public hospital, a situation that can potentially be extrapolated to other healthcare centers.

Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Sleep Apnea Syndromes/diagnosis , Polysomnography/methods , Sleep Apnea, Obstructive/diagnosis , Oxygen/metabolism , Sleep Apnea Syndromes/epidemiology , Chile/epidemiology , Retrospective Studies , Risk Factors , Sleep Apnea, Obstructive/epidemiology , Pediatric Obesity/epidemiology , Neuromuscular Diseases/epidemiology
Rev. bras. enferm ; 72(3): 592-599, May.-Jun. 2019. tab
Article in English | LILACS, BDENF | ID: biblio-1013536


ABSTRACT Objective: to describe the influence of oxygen in retinopathy of prematurity (ROP) in premature newborns (PTNB) hospitalized in neonatal units of intensive care and undergoing ophthalmological follow-up procedures after hospital discharge. Method: retrospective cohort study, from January 2014 to June 2016, whose data collection totaled 181 charts. Descriptive and inferential statistical analysis. Results: when using oxygen (O2) in 148 PTNB (81.7%), both mask (n=141; 77.9%; p-value <0.001) and the tracheal tube predominated (n=100; 55.25; p-value <0.001) for 15 days in average. The time of use and O2 concentration of the tracheal tube (p-value <0.001), the time of mask use (p-value <0.001) and the time and concentration of O2 of the continuous positive airway pressure (CPAP) (p-value <0.001) were significant to cause ROP in 50 PTNB (11.31%). Conclusion: the oxygen therapy has influenced the development and severity of ROP, indicating the need to adopt protocols for its use.

RESUMEN Objetivo: describir la influencia del oxígeno en la retinopatía del prematuro (ROP) en recién nacidos prematuros (RNPT) hospitalizados en unidad de cuidados intensivos neonatal y en seguimiento tras alta hospitalaria por servicio de oftalmología del estado del Paraná, en Brasil. Método: estudio de cohorte retrospectivo, en recorte temporal de enero del 2014 a junio del 2016, con recolección de datos en 181 fichas clínicas. Análisis estadístico descriptivo e inferencial. Resultados: utilizaron oxígeno (O2) 148 RNPT (81,7 %), predominando máscara (n=141; 77,9%; p-valor < 0,001) e intubación orotraqueal (TOT) (n=100; 55,25; p-valor < 0,001), alrededor de 15 días. El tiempo de uso y la concentración de O2 de TOT (p-valor < 0,001), tiempo de uso de máscara (p-valor < 0,001) y tiempo y concentración de O2 del continuous positive airway pressure (CPAP) (p-valor < 0,001) fueron significativos para desencadenar la ROP en 50 (11,31 %) RNPT. Conclusión: la terapéutica con oxígeno influyó en el desarrollo y gravedad de la ROP, indicando la necesidad de adoptar protocolos para su uso.

RESUMO Objetivo: descrever a influência do oxigênio na retinopatia da prematuridade (ROP) em recém-nascidos prematuros (RNPT) hospitalizados em unidade de terapia intensiva neonatal e em seguimento pós-alta hospitalar por serviço de oftalmologia do Paraná. Método: estudo de coorte retrospectivo, em recorte temporal de janeiro de 2014 a junho de 2016, com coleta de dados em 181 prontuários. Análise estatística descritiva e inferencial. Resultados: utilizaram oxigênio (O2) 148 RNPT (81,7%), predominando máscara (n=141; 77,9%; p-valor < 0,001) e tubo orotraqueal (TOT) (n=100; 55,25; p-valor < 0,001), em média por 15 dias. O tempo de uso e a concentração de O2 de TOT (p-valor < 0,001), tempo de uso de máscara (p-valor < 0,001) e tempo e concentração de O2 do continuous positive airway pressure (CPAP) (p-valor < 0,001) foram significativos para desencadear a ROP em 50 (11,31%) RNPT. Conclusão: a terapêutica com oxigênio influenciou no desenvolvimento e gravidade da ROP, indicando a necessidade de adoção de protocolos para seu uso.

Humans , Oxygen/metabolism , Retinopathy of Prematurity/etiology , Infant, Premature/physiology , Oxygen/adverse effects , Retinopathy of Prematurity/physiopathology , Brazil , Infant, Premature/growth & development , Retrospective Studies , Cohort Studies , Gestational Age
Rev. bras. ter. intensiva ; 31(2): 113-121, abr.-jun. 2019. graf
Article in Portuguese | LILACS | ID: biblio-1013758


RESUMO Objetivo: Descrever a transferência de energia do ventilador mecânico para os pulmões; o acoplamento entre a transferência de oxigênio por oxigenação por membrana extracorpórea venovenosa (ECMO-VV) e o consumo de oxigênio do paciente; a remoção de dióxido de carbono com ECMO; e o efeito potencial da oxigenação venosa sistêmica na pressão arterial pulmonar. Métodos: Modelo matemático com cenários hipotéticos e utilização de simulações matemáticas por computador. Resultados: A transição de ventilação protetora para ventilação ultraprotetora em um paciente com síndrome da angústia respiratória aguda grave e complacência respiratória estática de 20mL/cmH2O reduziu a transferência de energia do ventilador para os pulmões de 35,3 para 2,6 joules por minuto. Em um paciente hipotético, hiperdinâmico e ligeiramente anêmico com consumo de oxigênio de 200mL/minuto, é possível atingir saturação arterial de oxigênio de 80%, ao mesmo tempo em que se mantém o equilíbrio entre a transferência de oxigênio pela ECMO e o consumo de oxigênio do paciente. O dióxido de carbono é facilmente removido e a pressão parcial de dióxido de carbono normal é facilmente obtida. A oxigenação do sangue venoso, por meio do circuito da ECMO, pode direcionar o estímulo da pressão parcial de oxigênio na vasoconstrição pulmonar por hipóxia para valores normais. Conclusão: A ventilação ultraprotetora reduz amplamente a transferência de energia do ventilador para os pulmões. A hipoxemia grave no suporte com ECMO-VV pode ocorrer, a despeito do acoplamento entre a transferência de oxigênio, por meio da ECMO, e o consumo de oxigênio do paciente. A faixa normal de pressão parcial de dióxido de carbono é fácil de atingir. O suporte com ECMO-VV potencialmente alivia a vasoconstrição pulmonar hipóxica.

ABSTRACT Objective: To describe (1) the energy transfer from the ventilator to the lungs, (2) the match between venous-venous extracorporeal membrane oxygenation (ECMO) oxygen transfer and patient oxygen consumption (VO2), (3) carbon dioxide removal with ECMO, and (4) the potential effect of systemic venous oxygenation on pulmonary artery pressure. Methods: Mathematical modeling approach with hypothetical scenarios using computer simulation. Results: The transition from protective ventilation to ultraprotective ventilation in a patient with severe acute respiratory distress syndrome and a static respiratory compliance of 20mL/cm H2O reduced the energy transfer from the ventilator to the lungs from 35.3 to 2.6 joules/minute. A hypothetical patient, hyperdynamic and slightly anemic with VO2 = 200mL/minute, can reach an arterial oxygen saturation of 80%, while maintaining the match between the oxygen transfer by ECMO and the VO2 of the patient. Carbon dioxide is easily removed, and normal PaCO2 is easily reached. Venous blood oxygenation through the ECMO circuit may drive the PO2 stimulus of pulmonary hypoxic vasoconstriction to normal values. Conclusion: Ultraprotective ventilation largely reduces the energy transfer from the ventilator to the lungs. Severe hypoxemia on venous-venous-ECMO support may occur despite the matching between the oxygen transfer by ECMO and the VO2 of the patient. The normal range of PaCO2 is easy to reach. Venous-venous-ECMO support potentially relieves hypoxic pulmonary vasoconstriction.

Humans , Female , Adult , Oxygen/metabolism , Respiratory Distress Syndrome/therapy , Extracorporeal Membrane Oxygenation/methods , Models, Theoretical , Oxygen Consumption , Computer Simulation , Carbon Dioxide/metabolism , Pulmonary Gas Exchange , Energy Transfer , Hypertension, Pulmonary/physiopathology , Lung/metabolism , Lung/pathology
Rev. bras. ter. intensiva ; 31(2): 156-163, abr.-jun. 2019. tab, graf
Article in Portuguese | LILACS | ID: biblio-1013763


RESUMO Objetivo: Avaliar a eficácia e a segurança da oxigenoterapia com uso de cânula nasal de alto fluxo no tratamento da insuficiência respiratória hipercápnica moderada em pacientes que não conseguem tolerar ou têm contraindicações para ventilação mecânica não invasiva. Métodos: Estudo prospectivo observacional de 13 meses envolvendo participantes admitidos a uma unidade de terapia intensiva com insuficiência respiratória hipercápnica ou durante o processo de seu desenvolvimento. Os parâmetros clínicos e de troca gasosa foram registrados em intervalos regulares durante as primeiras 24 horas. Os parâmetros finais foram saturação de oxigênio entre 88 e 92%, juntamente da redução do esforço respiratório (frequência respiratória) e da normalização do pH (≥ 7,35). Os participantes foram considerados não responsivos em caso de necessidade de utilização de suporte ventilatório. Resultados: Trinta participantes foram tratados utilizando oxigenoterapia com cânula nasal de alto fluxo. Esta foi uma população mista com exacerbação de doença pulmonar obstrutiva crônica, edema pulmonar cardiogênico agudo, e insuficiência respiratória aguda pós-operatória e pós-extubação. Observou-se melhora não significante na frequência respiratória (28,0 ± 0,9 versus 24,3 ± 1,5; p = 0,22), que foi aparente nas primeiras 4 horas do tratamento. Ocorreu melhora do pH, embora só se tenham obtido níveis normais após 24 horas de tratamento com cânula nasal de alto fluxo (7,28 ± 0,02 versus 7,37 ± 0,01; p = 0,02). A proporção de não responsivos foi de 13,3% (quatro participantes), dos quais um necessitou e aceitou ventilação mecânica não invasiva, e três necessitaram de intubação. A mortalidade na unidade de terapia intensiva foi de 3,3% (um participante), e um paciente morreu após a alta para a enfermaria (mortalidade hospitalar de 6,6%). Conclusão: O oxigenoterapia com cânula nasal de alto fluxo é eficaz para a insuficiência respiratória hipercápnica moderada e ajuda a normalizar os parâmetros clínicos e de troca gasosa, com taxa aceitável de não responsivos que necessitaram de suporte ventilatório.

ABSTRACT Objective: To assess the efficacy and safety of high-flow nasal cannula oxygen therapy in treating moderate hypercapnic respiratory failure in patients who cannot tolerate or have contraindications to noninvasive mechanical ventilation. Methods: A prospective observational 13-month study involving subjects admitted to an intensive care unit with or developing moderate hypercapnic respiratory failure. Clinical and gas exchange parameters were recorded at regular intervals during the first 24 hours. The endpoints were a oxygen saturation between 88 and 92% along with a reduction in breathing effort (respiratory rate) and pH normalization (≥ 7.35). Subjects were considered nonresponders if they required ventilatory support. Results: Thirty subjects were treated with high-flow nasal cannula oxygen therapy. They consisted of a mixed population with chronic obstructive pulmonary disease exacerbation, acute cardiogenic pulmonary edema, and postoperative and postextubation respiratory failure. A nonsignificant improvement was observed in respiratory rate (28.0 ± 0.9 versus 24.3 ± 1.5, p = 0.22), which was apparent in the first four hours of treatment. The pH improved, although normal levels were only reached after 24 hours on high-flow nasal cannula therapy (7.28 ± 0.02 versus 7.37 ± 0.01, p = 0.02). The rate of nonresponders was 13.3% (4 subjects), of whom one needed and accepted noninvasive mechanical ventilation and three required intubation. Intensive care unit mortality was 3.3% (1 subject), and a patient died after discharge to the ward (hospital mortality of 6.6%). Conclusion: High-flow nasal cannula oxygen therapy is effective for moderate hypercapnic respiratory failure as it helps normalize clinical and gas exchange levels with an acceptable rate of nonresponders who require ventilatory support.

Humans , Male , Female , Aged , Oxygen Inhalation Therapy/methods , Respiratory Insufficiency/therapy , Hypercapnia/therapy , Intensive Care Units , Oxygen/administration & dosage , Oxygen/metabolism , Oxygen Inhalation Therapy/adverse effects , Pulmonary Gas Exchange , Prospective Studies , Treatment Outcome , Cannula , Middle Aged
Rev. bras. anestesiol ; 69(3): 315-318, May-June 2019.
Article in English | LILACS | ID: biblio-1013411


Abstract Background: Trigeminocardiac reflex is a physiological phenomenon that may occur in head and neck surgery, and is usually benign. However, it may present with exaggerated responses with severe morbidity. Case report: Male patient, 26 years old, candidate for surgical treatment of zygomatic-orbital complex fracture. The surgery with bilateral nasal packing placed at the end of the procedure was uneventful. After being admitted to the post-anesthesia care unity, the patient complained of shortness of breath and nausea. Pulse oximetry fell below 90% in ambient air, and 100% O2 was then offered through a Hudson mask. He showed no improvement in oximetry and presented with worsening dyspnea, diffuse wheezing, reduced heart rate, and blood pressure. Atropine was given, which raised the heart rate, but without resolution of hypotension and bronchospasm. Our suspicion was of a trigeminal-cardiac reflex, and then the removal of the nasal packing was done with complete remission of the signs and symptoms. Discussion: Florian Kratschmer (1870) was the first to describe the influences of nasal mucosal reflexes on respiration and circulation, which became known as Kratschmer's reflex. It is a reflex arc whose afferent originates in the nerve endings of the trigeminal nerve. The clinical presentation of trigeminocardiac reflex is the occurrence of sudden bradycardia, hypotension, apnea, and gastric hypermotility. Conclusion: Trigeminocardiac reflex may be a protective neurogenic, oxygen-conserving response with low morbidity, however, exacerbated in certain situations. The interaction between surgeon and anesthesiologist, together with a careful monitoring of blood pressure and heart rate are fundamental for diagnosis and treatment.

Resumo Justificativa: O reflexo trigêmino-cardíaco é um fenômeno fisiológico passível de ocorrer em cirurgias da cabeça e pescoço, e normalmente é benigno. Contudo, pode apresentar respostas exageradas, com grave morbidade. Relato de caso: Paciente masculino, 26 anos, candidato a tratamento cirúrgico de fratura do complexo zigomático-orbitário. Ato cirúrgico sem intercorrências com tamponamento nasal bilateral ao final. Após admitido na sala de recuperação pós-anestésica, queixou-se de "falta de ar" e náusea. A oximetria de pulso caiu abaixo 90% em ar ambiente e foi ofertado então O2 a 100% sob máscara de Hudson. Não houve melhora da oximetria e apresentou piora da dispneia, com sibilos difusos, redução da frequência cardíaca e da pressão arterial. Administrada atropina, que elevou a frequência cardíaca, mas sem resolução da hipotensão arterial e broncoespasmo. Aventamos a hipótese de reflexo trigêmino-cardíaco e então foi feita a remoção do tamponamento nasal com remissão completa dos sinais e sintomas. Discussão: Florian Kratschmer (1870) foi o primeiro a descrever as influências de reflexos da mucosa nasal na respiração e na circulação, o que ficou conhecido como reflexo de Kratschmer. Trata-se de um arco reflexo cuja aferência é originária nas terminações nervosas do nervo trigêmeo. A apresentação clínica do reflexo trigêmino-cardíaco é a ocorrência de súbita bradicardia, hipotensão, apneia e hipermotilidade gástrica. Conclusão: O reflexo trigêmino-cardíaco pode ser uma resposta neurogênica protetora, oxigênio-conservadora, de baixa morbidade, contudo exacerbada em determinadas situações. A interação entre cirurgião e anestesiologista, aliada à monitoração criteriosa da pressão arterial e do ritmo cardíaco, é fundamental para o diagnóstico e o tratamento.

Humans , Male , Adult , Postoperative Complications/diagnosis , Oral Surgical Procedures/methods , Reflex, Trigeminocardiac/physiology , Oxygen/metabolism , Blood Pressure/physiology , Heart Rate/physiology
Biol. Res ; 52: 32, 2019. graf
Article in English | LILACS | ID: biblio-1038783


BACKGROUND: Long non-coding RNA H19 (H19) plays an important role by regulating protein expression in different tissues and organs of the body. However, whether H19 induces hypoxia/reoxygenation (h/R) injury via increase of autophagy in the hepatoma carcinoma cells is unknown. RESULTS: H19 was expressed in the hepatoma carcinoma cells (Hep G2 and HCCLM3 cells) and its expression was most in 8 h/24R. The knockdown of H19 and 3-MA (an autophagy inhibitor) protected against h/R-induced apoptosis, cell damage, the expression of cleaved caspase-3 and cleaved caspase-9, the release of cytochrome c (Cyt c). The knockdown of H19 and 3-MA also decreased the autophagic vesicles (AVs) and the expression of Beclin-1 and the ration of LC3-II/LC3-I, and increased cell viability, the expression of Bcl-2 and P62 and the phosphorylation of PI3K, Akt and mTOR. In addition, chloroquine (CQ, an inhibitor of autophagy flux) markedly decreased formation of autophagy flux (the ration of LC3-II/LC3-I). The results of the knockdown of H19 group were similar to those of the 3-MA (or CQ) group. Rapamycin (a mTOR inhibitor, an autophagy activator) further down-regulated h/R-induced decrease of the phosphorylated PI3K, Akt and mTOR. The knockdown of H19 cancelled the effect of rapamycin. The overexpression of H19 further expanded h/R-induced increase of the ration of LC3-II/LC3-I and decrease of the phosphorylated PI3K, Akt and mTOR. CONCLUSIONS: Our results suggest that the long non-coding RNA H19 induces h/R injury by up-regulation of autophagy via activation of PI3K-Akt-mTOR pathway in the hepatoma carcinoma cells.

Humans , Reperfusion Injury/metabolism , Carcinoma, Hepatocellular/metabolism , RNA, Long Noncoding/metabolism , Liver Neoplasms/metabolism , Hypoxia/metabolism , Oxygen/metabolism , Autophagy/drug effects , Up-Regulation/physiology , Brain Ischemia/metabolism , Apoptosis/physiology , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/pathology
Acta cir. bras ; 34(4): e201900407, 2019. graf
Article in English | LILACS | ID: biblio-1001083


Abstract Purpose: To evaluate the functional and structural response of tadalafil effects in the intestinal mucosa, using an experimental model of hypoxia and reoxygenation injury in rats. Methods: The animals were divided into 4 groups: CTL, H/R, H/R+Td and M+Td. The newborn rats allocated in groups H/R, H/R+Td and M+Td were submitted twice a day, to a gas chamber with CO2 at 100% for 10 minutes and afterward reoxygenation with O2 at 98% for 10 minutes, in the three first days of life. Tadalafil dose was given to newborn of group H/R+Td and to the pregnant rat of group M+Td. Histological analysis was made with hematoxylin-eosin technique and oxidative stress through nitrite and nitrate levels and lipid peroxidation. Results: The histological analysis showed a reduction of mucosa alterations in the groups that received tadalafil. In the oxidative stress evaluation, occurred an increase of NO levels and less lipidic peroxidation in the ileum segments that received tadalafil. Conclusion: Tadalafil provides tissue protection when administered independently to both, pregnant or newborns.

Humans , Animals , Female , Pregnancy , Oxygen/metabolism , Oxidative Stress/drug effects , Phosphodiesterase 5 Inhibitors/pharmacology , Tadalafil/pharmacology , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Hypoxia/metabolism , Time Factors , Lipid Peroxidation , Random Allocation , Reproducibility of Results , Rats, Wistar , Intestinal Mucosa/pathology , Animals, Newborn , Malondialdehyde/analysis , Nitrates/analysis , Nitrites/analysis
J. bras. pneumol ; 45(5): e20180067, 2019. tab, graf
Article in English | LILACS | ID: biblio-990118


ABSTRACT Objective: To compare the effects that prone and supine positioning during high-frequency oscillatory ventilation (HFOV) have on oxygenation and lung inflammation, histological injury, and oxidative stress in a rabbit model of acute lung injury (ALI). Methods: Thirty male Norfolk white rabbits were induced to ALI by tracheal saline lavage (30 mL/kg, 38°C). The injury was induced during conventional mechanical ventilation, and ALI was considered confirmed when a PaO2/FiO2 ratio < 100 mmHg was reached. Rabbits were randomly divided into two groups: HFOV in the supine position (SP group, n = 15); and HFOV with prone positioning (PP group, n = 15). For HFOV, the mean airway pressure was initially set at 16 cmH2O. At 30, 60, and 90 min after the start of the HFOV protocol, the mean airway pressure was reduced to 14, 12, and 10 cmH2O, respectively. At 120 min, the animals were returned to or remained in the supine position for an extra 30 min. We evaluated oxygenation indices and histological lung injury scores, as well as TNF-α levels in BAL fluid and lung tissue. Results: After ALI induction, all of the animals showed significant hypoxemia, decreased respiratory system compliance, decreased oxygenation, and increased mean airway pressure in comparison with the baseline values. There were no statistically significant differences between the two groups, at any of the time points evaluated, in terms of the PaO2 or oxygenation index. However, TNF-α levels in BAL fluid were significantly lower in the PP group than in the SP group, as were histological lung injury scores. Conclusions: Prone positioning appears to attenuate inflammatory and histological lung injury during HFOV in rabbits with ALI.

RESUMO Objetivo: Comparar os efeitos das posições prona e supina durante ventilação oscilatória de alta frequência (VOAF) sobre oxigenação e inflamação pulmonar, lesão histológica e estresse oxidativo em um modelo de lesão pulmonar aguda (LPA) em coelhos. Métodos: Trinta coelhos Norfolk machos brancos foram submetidos à LPA por meio de lavagem traqueal com salina (30 ml/kg, 38°C). A lesão foi induzida durante a ventilação mecânica convencional, e a LPA foi considerada confirmada na presença de relação PaO2/FiO2 < 100 mmHg. Os coelhos foram aleatoriamente divididos em dois grupos: VOAF em posição supina (grupo PS, n = 15); e VOAF em posição prona (grupo PP, n = 15). Para a VOAF, a pressão média das vias aéreas foi inicialmente estabelecida em 16 cmH2O. No 30º, 60º e 90º min após o início do protocolo de VOAF, a pressão média das vias aéreas foi reduzida para 14, 12 e 10 cmH2O, respectivamente. No 120º min, os animais foram recolocados ou permaneceram na posição supina por mais 30 min. Foram avaliados os índices de oxigenação e escores histológicos de lesão pulmonar, bem como os níveis de TNF-α em lavado broncoalveolar e tecido pulmonar. Resultados: Após a indução da LPA, todos os animais apresentaram hipoxemia significativa, diminuição da complacência do sistema respiratório, diminuição da oxigenação e aumento da pressão média das vias aéreas em comparação aos valores basais. Não houve diferenças estatisticamente significativas entre os dois grupos, em nenhum dos momentos avaliados, quanto a PaO2 e índice de oxigenação. Entretanto, os níveis de TNF-α no lavado broncoalveolar foram significativamente menores no grupo PP que no grupo PS, assim como os escores histológicos de lesão pulmonar. Conclusões: A posição prona parece atenuar a lesão pulmonar inflamatória e histológica durante a VOAF em coelhos com LPA.

Humans , Animals , Male , Rats , High-Frequency Ventilation/methods , Supine Position/physiology , Prone Position/physiology , Acute Lung Injury/prevention & control , Oxygen/metabolism , Reference Values , Time Factors , Bronchoalveolar Lavage Fluid/chemistry , High-Frequency Ventilation/adverse effects , Lipid Peroxidation , Prospective Studies , Reproducibility of Results , Tumor Necrosis Factor-alpha/analysis , Oxidative Stress , Models, Animal , Acute Lung Injury/pathology
J. appl. oral sci ; 27: e20180442, 2019. tab, graf
Article in English | LILACS, BBO | ID: biblio-1002405


Abstract Objective To assess pulp oxygen saturation levels (SaO2) in maxillary central incisors after dental bleaching. Materials and Methods 80 participants (160 teeth) were randomly allocated to four groups: G1 In-office bleaching with two applications of 35% hydrogen peroxide (HP) (20 minutes), followed by at-home bleaching with 10% carbamide peroxide (CP) (2 hours/day for 16 days); G2 - Same protocol as G1, plus desensitizing toothpaste; G3 - In-office bleaching with 35% HP and one application of placebo gel (20 minutes), followed by at-home bleaching with 10% CP (2 hours/day for 16 days); and G4 - Same protocol as G3, plus desensitizing toothpaste. Pulp SaO2 levels were measured before (T0) and immediately after (T1) in-office bleaching; on the 5th (T2), 8th (T3), 12th (T4), and 16th days of at-home bleaching (T5); and on the 7th (T6) and 30th (T7) days. Mean (SD) pulp SaO2 levels were compared within groups by generalized estimating equations (GEE) and Student's t-test (P<0.05). Results Mean pulp SaO2 at T0 was 84.29% in G1, 84.38% in G2, 84.79% in G3, and 85.83% in G4. At T1, these values decreased to 81.96%, 82.06%, 82.19%, and 81.15% in G1, G2, G3, and G4 respectively, with significant difference in G4 (P<0.05). During home bleaching, pulp SaO2 levels varied in all groups, with 86.55%, 86.60%, 85.71%, and 87.15% means at T7 for G1, G2, G3, and G4, respectively; G2 presented significant difference (P<0.05). Conclusions Pulp SaO2 level in maxillary central incisors was similar at baseline, reducing immediately after in-office bleaching, regardless of using desensitizing toothpaste and increasing at 30 days after dental bleaching.

Humans , Male , Female , Adolescent , Adult , Young Adult , Oxygen/metabolism , Tooth Bleaching/adverse effects , Dental Pulp/metabolism , Tooth Bleaching Agents/adverse effects , Incisor/metabolism , Reference Values , Time Factors , Tooth Bleaching/methods , Toothpastes/therapeutic use , Oximetry/methods , Treatment Outcome , Dental Pulp/drug effects , Dentin Sensitivity/chemically induced , Dentin Sensitivity/prevention & control , Dentin Desensitizing Agents/therapeutic use , Carbamide Peroxide/adverse effects , Hydrogen Peroxide/adverse effects , Incisor/drug effects
In. Boggia de Izaguirre, José Gabriel; Hurtado Bredda, Francisco Javier; López Gómez, Alejandra; Malacrida Rodríguez, Leonel Sebastián; Angulo Nin, Martín; Seija Alves, Mariana; Luzardo Domenichelli, Leonella; Gadola Bergara, Liliana; Grignola Rial, Juan Carlos. Fisiopatología: mecanismos de las disfunciones orgánicas. Montevideo, BiblioMédica, 2 ed; c2019. p.379-399, ilus, graf.
Monography in Spanish | LILACS, UY-BNMED, BNUY | ID: biblio-1437044
Braz. dent. j ; 29(6): 541-546, Nov.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974196


Abstract The present study assessed oxygen saturation (SaO2) levels before, during, and after at-home bleaching treatment in the pulps of healthy maxillary central incisors. SaO2 levels were measured in 136 healthy maxillary central incisors using a pulse oximeter. The bleaching protocol consisted of 10% carbamide peroxide gel placed in individual trays and used for four hours daily for 14 days. SaO2 levels were assessed before bleaching (T0), immediately after the first session (T1), on the 7th day of treatment (T2), on the 15th day (the day following the last session) (T3), and 30 days after completion of the bleaching protocol (T4). Data were statistically analyzed using generalized estimating equations (GEE), Student's t test (p<0.05) and Pearson's correlation. Mean pulp SaO2 levels were 85.1% at T0, 84.9% at T1, 84.7% at T2, 84.3% at T3, and 85.0% at T4. Gradual reductions in SaO2 levels were observed, with significant differences (p<0.001) during the course of home bleaching treatment. However, 30 days after the end of the bleaching protocol, SaO2 levels returned to baseline levels. Home bleaching caused a reversible transient decrease in SaO2 levels in the pulps.

Resumo Este estudo verificou o grau de saturação de oxigênio (SaO2) pulpar antes, durante e após o clareamento dental caseiro em incisivos centrais superiores hígidos. O nível de SaO2 foi verificado em 136 incisivos centrais superiores hígidos usando oxímetro de pulso. A técnica de clareamento empregou peróxido de carbamida 10% em moldeira individual por quatro horas diárias durante 14 dias. Os níveis de SaO2 foram analisados antes do clareamento (T0), imediatamente após a primeira sessão (T1), no sétimo dia de tratamento (T2), no décimo quinto dia (um dia após a última sessão) (T3) e 30 dias após o término do clareamento dental (T4). A análise estatística utilizou o modelo de equações de estimações generalizadas (GEE), teste t de Student (p<0,05) e correlação de Pearson. Os níveis médios de SaO2 pulpar foram 85,1% em T0, 84,9% em T1, 84,7% em T2, 84,3% em T3 e 85,0% em T4. Foi observada uma redução gradual dos níveis de SaO2, com diferenças significantes (p<0,001) durante o clareamento dental caseiro. No entanto, 30 dias após o término do clareamento dental, houve retorno aos valores iniciais. O clareamento dental caseiro provocou uma diminuição transitória reversível no grau de SaO2 pulpar.

Humans , Male , Female , Adult , Oxygen/metabolism , Tooth Bleaching/methods , Dental Pulp/drug effects , Dental Pulp/metabolism , Carbamide Peroxide/pharmacology , Incisor/drug effects , Oximetry , Prospective Studies , Dental Pulp Test , Tooth Bleaching Agents/pharmacology , Maxilla
Braz. j. microbiol ; 49(3): 662-667, July-Sept. 2018. tab, graf
Article in English | LILACS | ID: biblio-951808


Abstract The effect of the intracellular microenvironment in the presence of an oxygen vector during expression of a fusion protein in Escherichia coli was studied. Three organic solutions at different concentration were chosen as oxygen vectors for fumarase expression. The addition of n-dodecane did not induce a significant change in the expression of fumarase, while the activity of fumarase increased significantly to 124% at 2.5% n-dodecane added after 9 h induction. The concentration of ATP increased sharply during the first 6 h of induction, to a value 7600% higher than that in the absence of an oxygen-vector. NAD/NADH and NADP/NADPH ratios were positively correlated with fumarase activity. n-Dodecane can be used to increase the concentration of ATP and change the energy metabolic pathway, providing sufficient energy for fumarase folding.

Oxygen/metabolism , Gene Expression , Alkanes/metabolism , Escherichia coli/genetics , Fumarate Hydratase/metabolism , Oxygen/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Recombinant Proteins/chemistry , Protein Folding , Alkanes/chemistry , Escherichia coli/metabolism , Fumarate Hydratase/genetics , Fumarate Hydratase/chemistry , NADP/metabolism , NADP/chemistry