Significado biológico y utilidad clínica del lactato en la sepsis / Biological significance and clinical utility of lactate in sepsis

La sepsis es un problema global de salud y la progresión hacia el shock séptico se asocia con un incremento marcado de la morbimortalidad. En este escenario, el aumento del lactato plasmático demostró ser un indicador de gravedad y un predictor de mortalidad, y suele interpretarse casi exclusivamente como marcador de baja perfusión tisular. Sin embargo, últimamente se produjo un cambio de paradigma en la exégesis del metabolismo y propiedades biológicas del lactato. En efecto, la adaptación metabólica al estrés, aun con adecuado aporte de oxígeno, puede justificar la elevación del lactato circulante. Asimismo, otras consecuencias fisiopatológicas de la sepsis, como la disfunción mitocondrial, se asocian con el desarrollo de hiperlactatemia sin que necesariamente se acompañen de baja perfusión tisular. Interpretar el origen y la función del lactato puede resultar de suma utilidad clínica en la sepsis, especialmente cuando sus niveles circulantes fundamentan las medidas de reanimación.

Sepsis is a global health problem; progression to septic shock is associated with a marked increase in morbidity and mortality. In this setting, increased plasma lactate levels demonstrated to be an indicator of severity and a predictor of mortality, and are usually interpreted almost exclusively as a marker of low tissue perfusion. However, a recent paradigm shift has occurred in the exegesis of lactate metabolism and its biological properties. Indeed, metabolic adaptation to stress, even with an adequate oxygen supply, may account for high circulating lactate levels. Likewise, other pathophysiological consequences of sepsis, such as mitochondrial dysfunction, are associated with the development of hyperlactatemia, which is not necessarily accompanied by low tissue perfusion. Interpreting the origin and function of lactate may be of great clinical utility in sepsis, especially when circulating lactate levels are the basis for resuscitative measures.

Performance Evaluation of Geometrically Different Pediatric Arterial Cannulae in a Pediatric Cardiopulmonary Bypass Model

ABSTRACT Objective: To define a reference chart comparing pressure drop vs. flow generated by a set of arterial cannulae currently utilized in cardiopulmonary bypass conditions in pediatric surgery. Methods: Cannulae from two manufacturers were selected considering their design and outer and inner diameters. Cannula performance was evaluated in terms of pressure drop vs. flow during simulated cardiopulmonary bypass conditions. The experimental circuits consisted of a Jostra HL-20 roller pump, a Quadrox-i pediatric oxygenator (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set. The circuit was primed with lactated Ringer's solution only (first condition) and with human packed red blood cells added (second condition) to achieve a hematocrit of 30%. Cannula sizes 8 to 16 Fr were inserted into the cardiopulmonary bypass circuit with a "Y" connector. The flow was adjusted in 100 ml/min increments within typical flow ranges for each cannula. Pre-cannula and post-cannula pressures were measured to calculate the pressure drop. Results: Utilizing a pressure drop limit of 100 mmHg, our results suggest a recommended flow limit of 500, 900, 1400, 2600, and 3100 mL/min for Braile arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, respectively. For Medtronic DLP arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, the recommended flow limit is 600, 1100, 1700, 2700, and 3300 mL/min, respectively. Conclusion: This study reinforces discrepancies in pressure drop between cannulae of the same diameter supplied by different manufacturers and the importance of independent translational research to evaluate components' performance.

Acute physiological responses to "recovery intermittent hypoxia" in hiit / Respuestas agudas a la "hipoxia intermitente de recuperación" en el hiit / Respostas fisiológicas agudas à "hipóxia intermitente de recuperação" no hiit

ABSTRACT Introduction: Traditional intermittent hypoxia training improves sport performance after short periods of exposure, but acute exposure to intermittent hypoxia leads to decreased training intensity and technical quality. The solution to overcome these negative effects may be to perform efforts in normoxia and the intervals between efforts in hypoxia, maintaining the quality of training and the benefits of hypoxia. Objective: This study aimed to evaluate the acute physiological responses to hypoxia exposure during recovery between high intensity efforts. Materials and methods: Randomized, one-blind, placebo-controlled study. Sixteen men performed a graded exercise test to determine their maximal intensity and two sessions of high-intensity interval training. The training intervals could be in hypoxia (HRT), FIO2: 0.136 or normoxia (NRT), FIO2: 0.209. During the two-minute interval between the ten one-minute efforts, peripheral oxygen saturation (SpO2), heart rate (HR), blood lactate ([La]), blood glucose ([Glu]) were constantly measured. Results: There were differences in HR (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p < 0.01) and SpO2 (TRN = 96.9 ± 1.0%; TRH = 86.2 ± 3.5%, p < 0.01). No differences in [La] and [Glu] TRN (4.4 ± 1.7 mmol.l-1; 3.9 ± 0.5 mmol.l-1) and TRH (5.2 ± 2.0 mmol.l-1; 4.0 ± 0.8 mmol.l-1, p = 0.17). Conclusion: The possibility of including hypoxia only in the recovery intervals as an additional stimulus to the training, without decreasing the quality of the training, was evidenced. Level of Evidence II; Randomized Clinical Trial of Minor Quality.

RESUMEN Introducción: El entrenamiento tradicional en hipoxia intermitente mejora el rendimiento deportivo tras cortos periodos de exposición, sin embargo, la exposición aguda a la hipoxia intermitente conduce a una disminución de la intensidad del entrenamiento y de la calidad técnica. La solución para superar estos efectos negativos puede ser realizar los esfuerzos en normoxia y los intervalos entre esfuerzos en hipoxia, manteniendo la calidad del entrenamiento y los beneficios de la hipoxia. Objetivo: Este estudio pretendía evaluar las respuestas fisiológicas agudas a la exposición a la hipoxia durante la recuperación entre esfuerzos de alta intensidad. Materiales y métodos: Estudio aleatorizado, a ciegas y controlado con placebo. Dieciséis hombres realizaron una prueba de ejercicio graduado para determinar su intensidad máxima y dos sesiones de entrenamiento por intervalos de alta intensidad. Los intervalos de entrenamiento podían ser en hipoxia (HRT), FIO2: 0,136 o normoxia (NRT), FIO2: 0,209. Durante el intervalo de dos minutos entre los diez esfuerzos de un minuto, se midieron constantemente la saturación periférica de oxígeno (SpO2), la frecuencia cardiaca (FC), el lactato en sangre ([La]) y la glucemia ([Glu]). Resultados: Hubo diferencias en la FC (TRN = 120 ± 14 lpm; TRH = 129 ± 13 lpm, p < 0,01) y la SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p < 0,01). No hubo diferencias en [La] y [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) y TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusión: Se evidenció la posibilidad de incluir hipoxia sólo en los intervalos de recuperación como estímulo adicional al entrenamiento sin disminuir la calidad del mismo. Nivel de Evidencia II; Ensayo Clínico Aleatorizado de Baja Calidad.

RESUMO Introdução: O treinamento de hipóxia intermitente tradicional melhora o desempenho esportivo após curtos períodos de exposição, porém a exposição aguda à hipóxia intermitente leva à diminuição da intensidade do treinamento e da qualidade técnica. A solução para superar esses efeitos negativos pode ser realizar esforços em normóxia e os intervalos entre os esforços em hipóxia, mantendo a qualidade do treinamento e os benefícios da hipóxia. Objetivo: Este estudo teve como objetivo avaliar as respostas fisiológicas agudas à exposição de hipóxia durante a recuperação entre esforços de alta intensidade. Materiais e métodos: Estudo aleatório e one-blinded, com efeito placebo controlado. Dezesseis homens realizaram um teste de exercício graduado para determinar sua intensidade máxima e duas sessões de treinamento intervalado de alta intensidade. Os intervalos de treinamento podem ser em hipóxia (TRH), FIO2: 0,136 ou normóxia (TRN), FIO2: 0,209. Durante os dois minutos de intervalo entre os dez esforços de um minuto, foram medidos constantemente a saturação periférica de oxigênio (SpO2), frequência cardíaca (FC), lactato sanguíneo ([La]), glicemia ([Glu]). Resultados: Houve diferenças na FC (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p <0,01) e SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p <0,01). Sem diferenças em [La] e [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) e TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusão: Evidenciou-se a possibilidade de incluir a hipóxia apenas nos intervalos de recuperação como um estímulo adicional ao treinamento, sem diminuir a qualidade do treinamento. Nível de Evidência II; Estudo Clínico Randomizado de Menor Qualidade.

Mechanism of catalpol regulating Th17 cell differentiation by interfering PKM2/LDHA expression / 中国药房

OBJECTIVE To investigate the mechanism of catalpol affecting the differentiation of helper T cell 17 （Th17） by interfering the expressions of pyruvate kinase M2 （PKM2） and lactate dehydrogenase A （LDHA）. METHODS The naive CD4+ T cells were selected from the spleen of C57BL/6 mice， and were differentiated into Th17 cells by adding directional differentiation stimulants for 72 hours. At the same time， the cells were treated with 0 （directed control）， 20， 40 and 80 μg/mL catalpol. The flow cytometry was used to detect the proportion of Th17 cell differentiation in cells； the colorimetric method was adopted to detect the levels of pyruvate and lactate in cell culture supernatant； mRNA expressions of retinoid-related orphan nuclear receptor gamma t （RORγt）， PKM2 and LDHA were detected by qRT-PCR method； Western blot was used to detect the expression levels of PKM2， LDHA， signal transducer and activator of transcription 3 （STAT3）， and phosphorylated STAT3 （p-STAT3） proteins in cells. RESULTS Compared with the directed control group， after 72 hours of treatment with 20， 40， 80 μg/mL catalpol， the differentiation ratio of Th17 cells were decreased by 6.74%， 8.41%， 9.24%， and the levels of pyruvate and lactate in the cell culture supernatant， the mRNA expressions of PKM2， LDHA and RORγt as well as the protein expressions of PKM2 and LDHA and the phosphorylation of STAT3 were significantly reduced （P＜0.05）. CONCLUSIONS Catalpol can reduce the glycolysis level by down-regulating the expressions of PKM2 and LDHA， thereby inhibiting the differentiation of Th17 cells.

Lactate and Lactate Clearance Are Predictive Factors for Mortality in Patients with Extracorporeal Membrane Oxygenation

ABSTRACT Introduction: Findings of inadequate tissue perfusion might be used to predict the risk of mortality. In this study, we evaluated the effects of lactate and lactate clearance on mortality of patients who had undergone extracorporeal membrane oxygenation (ECMO). Methods: Patients younger than 18 years old and who needed venoarterial ECMO support after surgery for congenital heart defects, from July 2010 to January 2019, were retrospectively analyzed. Patients successfully weaned from ECMO constituted Group 1, and patients who could not be weaned from ECMO were in Group 2. Postoperative clinics and follow-ups of the groups including mortality and discharge rates were evaluated. Results: There were 1,844 congenital heart surgeries during the study period, and 55 patients that required ECMO support were included in the study. There was no statistically significant difference between the groups regarding demographics and operative variables. The sixth-, 12th-, and 24th-hour lactate levels in Group 1 were statistically significantly lower than those in Group 2 (P=0.046, P=0.024, and P<0.001, respectively). There were statistically significant differences regarding lactate clearance between the groups at the 24th hour (P=0.009). The cutoff point for lactate level was found as ≥ 2.9, with 74.07% sensitivity and 78.57% specificity (P<0.001). The cutoff point for lactate clearance was determined as 69.44%, with 59.26% sensitivity and 78.57% specificity (P=0.003). Conclusion: Prognostic predictive factors are important to initiate advanced treatment modalities in patients with ECMO support. In this condition, lactate and lactate clearance might be used as a predictive marker.

Lactate dehydrogenase as a hematopoietic stem cell mobilization biomarker in autologous transplantation

ABSTRACT Introduction: Pre-apheresis peripheral blood CD34+ cell count (PBCD34+) is the most important predictor of good cell mobilization before hematopoietic stem cell transplantation, albeit flow cytometry is not always immediately available. Identification of surrogate markers can be useful. The CD34+ cells proliferate after mobilization, resulting in elevated lactate dehydrogenase (LDH) activity and correlating with the PBCD34+ count. Objective: To determine the LDH cut-off value at which adequate CD34+ cell mobilization is achieved and its diagnostic yield. Materials and methods: A total of 103 patients who received an autologous stem cell transplantation (ASCT) between January 2015 and January 2020 were included. Demographic and laboratory characteristics were obtained, including complete blood count, pre-apheresis PBCD34+ and LDH levels. Receiver operating characteristic (ROC) curves were performed to identify the optimal serum LDH activity cut-off points for ≥ 2 and ≥ 4 × 106 cells/kg post-mobilization CD34+ count and their diagnostic yield. Results: A post-mobilization serum LDH cut-off value of 462 U/L yielded a sensitivity (Se) = 86.8% (positive predictive value [PPV] = 72.7%), a pre- and post-mobilization serum LDH difference cut-off value of 387 U/L, an Se = 45.7% (PPV = 97%) and an LDH ratio of 2.46, with an Se = 47.1% (PPV = 97%) for an optimal mobilization count (CD34+ ≥ 4 × 106). Conclusion: The LDH measurement represents a fast and affordable way to predict PBCD34+ mobilization in cases where flow cytometry is not immediately available. According to the LDH diagnostic yield, it could be used as a surrogate marker in transplant centers, supporting the CD34+ count, which remains the gold standard.

Lactate and pH values in newborns with a history of acute fetal distress / Valores de lactato y pH en recién nacidos con antecedente de sufrimiento fetal agudo

Abstract Background: Acute fetal distress (AFD) is a condition that requires timely diagnosis because it generates hypoxia, acidosis, and even intrauterine death. This study aimed to determine lactate and pH values in the umbilical cord in full-term newborns (NBs) with a history of AFD. Methods: We conducted a cross-sectional study in full-term NBs of mothers with at least one perinatal, neonatal, or gasometric AFD antecedent. Neonatal morbidity was considered: if 1-min Apgar ≤ 6, or advanced neonatal maneuvers, or neonatal intensive care unit (NICU) admissions were necessary. The cutoff points were lactate > 4mmol/L and pH < 7.2. Results: Of 66 NBs, 33.3% of mothers presented at least one antecedent for developing AFD; 22.7% presented hypertensive pregnancy disease, 13.6% oligohydramnios, and 63.6% other factors. Perinatally, 28.7% required advanced neonatal resuscitation maneuvers and 7.5% admission to the NICU. In the gasometry, the lactate and pH values for the neonatal morbidity of the NBs' group were 4.726 ± 1.401 and 7.293 ± 0.056, respectively, versus 2.240 ± 0.318 and 7.359 ± 0.022 (p < 0.05) for the group without associated neonatal morbidity. Conclusions: Lactate values in the umbilical cord increased by 25%, and pH decreased by one percent in NBs with a history of AFD and associated morbidity.

Resumen Introducción: El sufrimiento fetal agudo (SFA) es una condición que amerita un diagnóstico oportuno debido a que genera hipoxia, acidosis e incluso la muerte intrauterina. El objetivo de este estudio fue determinar los valores de lactato y pH en cordón umbilical en recién nacidos de término con antecedente SFA. Métodos: Se llevó a cabo un estudio transversal, en recién nacidos a término, de madres que tuvieron al menos un antecedente para SFA de tipo perinatal, neonatal o gasométrico. Se consideró morbilidad neonatal cuando presentaron Apgar al minuto ≤ 6, o requirieron maniobras avanzadas de reanimación neonatal, o ingreso a Unidad de Cuidados Intensivos Neonatales (UCIN). El punto de corte fue > 4 mmol/L para los valores de lactato y pH < 7.2. Resultados: De un total de 66 recién nacidos, el 33.3% de las madres presentaron al menos un antecedente para desarrollar SFA; el 22.7% presentó enfermedad hipertensiva del embarazo, el 13.6%, oligohidramnios, y el 63.6%, otros factores. El 28.7% requirieron maniobras avanzadas de la reanimación neonatal y el 7.5%, el ingreso a la UCIN. En la gasometría, el valor de lactato y pH para el grupo de recién nacidos con morbilidad neonatal fue de 4.726 ± 1.401 y 7.293 ± 0.056 respectivamente, versus 2.240 ± 0.318 y 7.359 ± 0.022 (p < 0.05) para el grupo sin morbilidad neonatal asociada. Conclusiones: Se observó un incremento del 25% de los valores de lactato en cordón umbilical y una disminución del 1% del pH en los recién nacidos con antecedente de SFA y morbilidad asociada.

Correlation of Venous to Arterial Carbon Dioxide Partial Pressure Difference with other Cardiac Output Indices in Patients Undergoing Intracardiac Repair for Tetralogy of Fallot

Background: Clearance of tissue carbon dioxide by circulation is measured by venous to arterial carbon dioxide partial pressure difference (AVCO2 ) and is correlated with cardiac output (CO) in critically ill adult patients. This study aimed to correlate AVCO2 with other CO indices like arteriovenous oxygen saturation difference (AVO2 ), central venous oxygen saturation (ScVO2 ), and serum lactate in pediatric patients undergoing intracardiac repair (ICR) for tetralogy of Fallot (TOF). Methods: We conducted a prospective observational study in 50 patients, of age 5months to 5 years, undergoing ICR for TOF and analyzed AVO2 , AVCO2 , ScVO2 , and lactate from arterial and venous blood gas pairs obtained at different time intervals from admission to pediatric intensive care unit(PICU)(T0 ), at 6 h (T1 ), 12 h (T2 ), 24 h (T3 ), and 48 h (T4 ) postoperatively. Bivariate correlations were analyzed using Pearson for parametric variables. Results: Admission AVCO2 was not correlated with AVO2 (R2 = 0.166, P = 0.246), ScVO2 (R2 = ?2.2, P = 0.124), and lactate (R2 = ?0.07, P = 0.624). At T1 , AVCO2 was correlated with AVO2 (R2 = 0.283, P = 0.0464) but not with ScVO2 (R2 = ? 0.25, P = 0.079) and lactate (R2 = ?0.07, P = 0.623). At T2 , T3 and T4 , AVCO2 was correlated with AVO2 (R2 = 0.338,0.440 & 0.318, P = 0.0162, 0.0013, and 0.024), ScVO2 (R2 = ? 0.344, ? 0.488, and ?0.366; P = 0.0143, <0.0001, and 0.017), and lactate (R2 = 0.305, 0.467 and 0.607; P = 0.0314, 0.00062 and <0.0001). AVCO2 was negatively correlated with ScVO2 . No correlation observed between admission AVCO2 and mechanical ventilation duration. Two nonsurvivors had higher value of admission AVCO2 compared to survivors. Conclusion: AVCO2 is correlated with other CO surrogates like AVO2 , ScVO2 , and lactate in pediatric patients undergoing ICR for TOF.

Lactate acid level and prognosis of neonatal necrotizing enterocolitis: a retrospective cohort study based on pediatric-specific critical care database

Abstract Objective To investigate the relationship between lactate acid level and hospitalization mortality in neonatal necrotizing enterocolitis (NEC). Method Paediatric-specific critical care database collected clinical data from the intensive care unit of Children's Hospital Affiliated to Zhejiang University Medical College from 2010 to 2018. Clinical and laboratory examination information of NEC patients was collected and divided into the death group and discharge group to find out the risk factors affecting the prognosis through univariate and multivariate analysis. Results Among 104 NEC neonates, the admission age was 7.5 days and the weight was 2.03 kg. Comparing the death group with the discharge group, there were significant differences in therapeutic regimen, pH, serum albumin, total protein, creatinine and lactate acid. Multivariate and threshold effect analysis showed that lactate acid had a linear correlation with hospital mortality, and newborns who died in the hospital had much higher lactate levels than those who were discharged. The mortality of NEC newborns increased by 40-45% for every 1 mmol/L increase in lactate acid level. Conclusions There was a correlation between lactate acid level and hospital mortality in newborns with NEC, and lactate acid level was an important index to evaluate the prognosis of NEC.

CORRELATION OF SERUM FERRITIN AND LDH ON CRITICALLY ILL PATIENTS OF COVID-19 DISEASE DURING 1ST AND 2ND WAVE OF COVID 19 PANDEMIC IN TERTIARY CARE HOSPITAL, INDIA

In both the earlier waves of COVID-19 variants, severe and fatal respiratory disease like acute respiratory distress syndrome (ARDS) became more fatal in population with comorbid conditions. Therefore, early identi?cation of severe COVID-19 is very important for individual's precise management, including antiviral, oxygen support and intensive care unit (ICU) management. First case of COVID-19 got reported in the medical record of India on 30th January 2020 in a student who had returned from Wuhan, China. In 2020 and 2021 it was found that individuals with increased serum ferritin and LDH level landed up with severe and very severe COVID-19 if not treated timely and correctly. So correlation between S. Ferritin and LDH in 1st and 2nd wave was required to evaluate the condition of patients who remained admitted in critical care unit with or without comorbid conditions. This is hospital based cross- sectional observational study on 50-50 (total-100) critically ill patients admitted during 2020 and 2021 respectively. We found that In 2020 during the 1st wave serum LDH and serum Ferritin levels were signi?cantly high with the mean value of 481.65 U/L and 532.56 ng/ml respectively and in 2021 during 2nd wave serum LDH and serum Ferritin levels were again signi?cantly high with the mean value of 488.43 U/L and 667.27 ng/ml respectively. In 2020 patients with comorbid conditions showed S. LDH and Ferritin mean value of 543.47 U/L and 582.63 ng/ml respectively and in 2021 during 2nd wave it showed S.LDH and Ferritin levels mean value of 672.72 U/L and 727.38 ng/ml respectively. Both in?ammatory markers were signi?cantly more increased in the critically ill patients who presented with co-morbidities. This study will provide improved con?dence to health workers working in remote areas and COVID-19 hospitals in predicting transfer of COVID-19 patients to tertiary care hospitals for critical care management at the earliest.

Lactic Acid Inhibits the Cytotoxicity of NK-92 Cells via Activating the Lactate Receptor GPR81

Aims: Lactate acid functions as not only an energy source but a signaling molecule through the lactate receptor GPR81 under physiological conditions. However, the pathological role of lactic acid in the tumor microenvironment remains unclear, particularly for immune cells. Methodology: NK-92 cells were treated with L-lactic acid solutions at final concentrations of 10, 20, 30, and 40 mM, and its cell viability and cytotoxicity on A549 cells and A375 cells were evaluated by CCK8 assay and crystal violet assay, respectively. Furthermore, qPCR was used to assess the expression of GPR81 and cytotoxicity-related genes in NK-92 cells treated with antagonist and agonist. And their relationship between lactate/GPR81 pathway and cytotoxicity-related genes were analyzed by Pearson’s correlation. Results: The viability of NK-92 cells was inhibited by L-lactic acid with increasing concentration. Additionally, the cytotoxic activity against tumor cells of NK-92 cells treated with L-lactic acid decreased with increasing concentration. Moreover, qPCR results demonstrated that GPR81 can be activated by lactic acid or agonist (3,5-DHBA) and downregulate the expression cytotoxicity-related genes which included FASLG gene(Fas Ligand),TNF-? gene(Tumor necrosis factor-?), INFG gene (Interferon-?), RPF1 gene (Perforin 1), GZMA gene (Granzyme A), GZMB gene (Granzyme B), GZMH gene (Granzyme H), GAMK gene (Granzyme K) and GZMM gene (Granzyme M). And the expression of GPR81 returned to near-control level when treated with L-lactic acid in the presence of antagonist (3-OBA), the expression of cytotoxicity-related genes did as well. Pearson’s correlation analysis of cytotoxicity-related genes with GPR81 revealed that their correlation coefficient seems negative. Conclusion: Lactic acid can activate the GPR81 to downregulate the expression of cytotoxicity-related genes, subsequently lower the cytotoxicity of NK-92 cells.

Electrochemical sensor for sweat monitoring / Sensor eletroquímico para monitoramento de suor / Sensor electroquímico para el control del sudor

ABSTRACT Introduction: Attention is given to developing electrochemical sensors for the rapid and real-time measurement of lactate levels. The synthesis of electrochemical sensors is based on an electrode modified with a nanocomposite. Objective: Analyze an electrochemical sensor's feasibility for sports monitoring sweat in lactate. The Au@CNTs were the main focus of this study. Methods: The Au@CNTs composite was synthesized on the GCE surface and tested under pre-established protocols as a sensor. Results: The shape and structure of the modified electrodes were analyzed using SEM. The results showed that the Au@CNTs nanoparticles in the Au@CNTs nanocomposite were evenly distributed throughout the porous CNTs network. The performance of the developed sensor was measured using cyclic voltammetry and amperometry. The electrochemical biosensor responded linearly to lactate over phosphate buffer solution with a low detection limit and sensitivity. Conclusion: The experiment of this sensor evaluated lactate concentrations in real sweat samples that were exceptionally close to the injection amount, enabling it as an effective biosensor for the detection of lactate in sweat samples. Level of Evidence: Therapeutic Studies - Outcome Investigation.

RESUMO Introdução: É dada atenção ao desenvolvimento de sensores eletroquímicos para a medição rápida e em tempo real dos níveis de lactato. A síntese de sensores eletroquímicos é baseada em um eletrodo modificado com um nanocomposto. Objetivo: Analisar a viabilidade de um sensor eletroquímico para monitoramento esportivo de suor em lactato. O Au@CNTs foi o foco principal deste estudo. Métodos: O composto Au@CNTs foi sintetizado na superfície GCE, e testado sob protocolos preestabelecidos como sensor. Resultados: A forma e estrutura dos eletrodos modificados foram analisadas usando SEM, e os resultados mostraram que as nanopartículas de Au@CNTs no nanocomposto Au@CNTs foram distribuídas uniformemente por toda a rede porosa de CNTs. O desempenho do sensor desenvolvido foi medido usando voltametria cíclica e amperometria. O biosensor eletroquímico respondeu linearmente ao lactato sobre solução tampão fosfato com um limite de detecção e sensibilidade reduzidos. Conclusão: O experimento deste sensor avaliou as concentrações de lactato em amostras de suor real que estavam excepcionalmente próximas à quantidade de injeção, habilitando-o como um biosensor efetivo para detecção de lactato em amostras de suor. Nível de evidência: Estudos Terapêuticos - Investigação dos Resultados.

RESUMEN Introducción: Se presta atención al desarrollo de sensores electroquímicos para la medición rápida y en tiempo real de los niveles de lactato. La síntesis de los sensores electroquímicos se basa en un electrodo modificado con un nanocompuesto. Objetivo: Analizar la viabilidad de un sensor electroquímico para la monitorización esporádica del sudor en el lactato. Los Au@CNTs fueron el objetivo principal de este estudio. Métodos: El compuesto de Au@CNTs se sintetizó sobre la superficie de GCE, y se probó bajo protocolos preestablecidos como sensor. Resultados: La forma y la estructura de los electrodos modificados se analizaron mediante SEM, y los resultados mostraron que las nanopartículas de Au@CNTs en el nanocompuesto de Au@CNTs estaban distribuidas uniformemente en la red porosa de CNTs. El rendimiento del sensor desarrollado se midió mediante voltamperometría cíclica y amperometría. El biosensor electroquímico respondió linealmente al lactato sobre la solución tampón de fosfato con un bajo límite de detección y sensibilidad. Conclusión: El experimento de este sensor evaluó las concentraciones de lactato en muestras reales de sudor que eran excepcionalmente cercanas a la cantidad inyectada, lo que le permite ser un biosensor eficaz para la detección de lactato en muestras de sudor. Nivel de evidencia: Estudios terapéuticos - Investigación de resultados.

Creatine supplementation for post-exercise muscle damage / Suplementação com creatina para danos musculares pós-exercício / Suplementación con creatina para daños musculares después del ejercicio

ABSTRACT Introduction: Exercise-induced muscle damage (EIMD) can occur from recent or unusual physical activity, leading to a temporary reduction in muscle function. And increased pain. Several articles indicate the positive impacts of creatine on EIMD. Objective: Evaluate the impact of creatine on EIMD. Methods: Online searches were performed in Scopus, Embase, Medline and Google scholar until March 2022. Results: Thirteen studies met the inclusion criteria. To assess the quality of the studies, the Cochrane collaboration system was used for risk and bias analysis. Due to the high heterogeneity of interventions and studies designed, a meta-analysis was not performed. The current paper reveals that creatine intake is preferable to inactive recovery and only a rest period between several harmful and exhausting physical activities. Conclusion: Benefits were attenuated in EIMD markers that reduce muscle operation and muscle strength loss after exercise. Level of evidence II; Therapeutic studies - Manuscript review.

RESUMO Introdução: O dano muscular induzido pelo exercício (EIMD) pode acontecer por atividade física recente ou não habitual e leva a uma redução temporária da função muscular. e aumento da dor. Vários artigos indicam impactos positivos da creatina sobre a EIMD. Objetivo: Avaliar o impacto da creatina sobre a EIMD. Métodos: Foram feitas pesquisas eletrônicas em Scopus, Embase, Medline e Google scholar até março de 2022. Resultados: Treze estudos preencheram os critérios de inclusão. Para avaliar a qualidade dos estudos, o sistema de colaboração Cochrane foi utilizado na análise de risco e viés. Devido à alta heterogeneidade de intervenções e estudos desenhados, a meta-análise não foi realizada. As informações do documento atual revelam que a ingestão de creatina é preferível a uma recuperação inativa e apenas um período de repouso entre diversas atividades físicas prejudiciais e exaustivas. Conclusão: Os benefícios evidenciaram-se atenuados nos marcadores EIMD que reduzem a operação muscular e a perda de força muscular após os exercícios. Nível de evidência II; Estudos terapêuticos - Revisão de manuscritos.

RESUMEN Introducción: el daño muscular inducido por el ejercicio (EIMD) puede producirse por una actividad física reciente o inusual y provoca una reducción temporal de la función muscular y un aumento del dolor. Varios artículos indican impactos positivos de la creatina en la EIMD. Objetivo: Evaluar el impacto de la creatina en la EIMD. Métodos: Se realizaron búsquedas electrónicas en Scopus, Embase, Medline y Google scholar hasta marzo de 2022. Resultados: Trece estudios cumplieron los criterios de inclusión. Para evaluar la calidad de los estudios, se utilizó el sistema de colaboración Cochrane para el análisis de riesgos y sesgos. Debido a la gran heterogeneidad de las intervenciones y de los estudios diseñados, no se realizó un metanálisis. La información del presente documento revela que la ingesta de creatina es preferible a una recuperación inactiva y sólo un período de descanso entre varias actividades físicas perjudiciales y agotadoras. Conclusión: Los beneficios se mostraron atenuados en los marcadores EIMD que reducen el funcionamiento muscular y la pérdida de fuerza muscular después del ejercicio. Nivel de evidencia II; Estudios terapéuticos - Revisión de manuscritos.

Relationship between peripheral ischemic microvascular reserve, persistent hyperlactatemia, and its temporal dynamics in sepsis: a post hoc study / Relação entre reserva microvascular isquêmica periférica, hiperlactatemia persistente e sua dinâmica temporal na sepse: um estudo post hoc

ABSTRACT Objective: To measure the prognostic value of peripheral ischemic microvascular reserve in the context of persistent sepsis-induced hyperlactatemia and measure its influence on the temporal dynamics of lactate and the strength of association between these variables. Methods: This post hoc analysis of the peripheral perfusion index/postocclusive reactive hyperemia trial, an observational cohort study that enrolled patients with sepsis who persisted with lactate levels ≥ 2mmol/L after fluid resuscitation (with or without shock). Peripheral ischemic microvascular reserve was evaluated using the association of the peripheral perfusion index and postocclusive reactive hyperemia techniques. The cutoff point of ∆ peripheral perfusion index peak values (%) defined the groups with low (≤ 62%) and high peripheral ischemic microvascular reserve (> 62%). Results: A total of 108 consecutive patients with persistent sepsis-induced hyperlactatemia were studied. The high peripheral ischemic microvascular reserve group showed higher 28-day mortality than the low peripheral ischemic microvascular reserve group (p < 0.01). The temporal dynamics of lactate within the first 48 hours showed a rapid decrease in lactate levels in the low peripheral ischemic microvascular reserve group (p < 0.01). However, this result was not reproduced in the linear mixed effects model. A weak correlation between peripheral ischemic microvascular reserve (%) and lactate level (mmol/L) was observed within the first 24 hours (r = 0.23; p < 0.05). Conclusion: The prognostic value of high peripheral ischemic microvascular reserve was confirmed in the context of persistent sepsis-induced hyperlactatemia. Although there was a weak positive correlation between peripheral ischemic microvascular reserve value and lactate level within the first 24 hours of sepsis diagnosis, the low peripheral ischemic microvascular reserve group appeared to have a faster decrease in lactate over the 48 hours of follow-up.

RESUMO Objetivo: Avaliar o valor prognóstico da reserva microvascular isquêmica periférica no contexto da hiperlactatemia persistente induzida pela sepse, determinar sua influência na dinâmica temporal de lactato e analisar a força da associação entre essas variáveis. Métodos: Análise post hoc do estudo de índice de perfusão periférica/hiperemia reativa pós-oclusiva caracterizada por uma coorte observacional que incluiu pacientes com sepse que persistiram com níveis de lactato ≥ 2mmol/L após a ressuscitação volêmica (com ou sem choque). A reserva microvascular isquêmica periférica foi mensurada utilizando-se a associação dos métodos do índice de perfusão periférica e hiperemia reativa pós-oclusiva. O ponto de corte dos valores da ∆ índice de perfusão periférica de pico (%) definiu os grupos com baixa (≤ 62%) e alta (> 62%) reserva microvascular isquêmica periférica. Resultados: Estudaram-se 108 pacientes consecutivos com hiperlactatemia persistente induzida pela sepse. O grupo com alta reserva microvascular isquêmica periférica apresentou maior mortalidade aos 28 dias em relação ao grupo com baixa reserva microvascular isquêmica periférica (p < 0,01). A dinâmica temporal de lactato nas primeiras 48 horas mostrou redução rápida dos níveis de lactato no grupo com baixa reserva microvascular isquêmica periférica (p < 0,01). No entanto, esse resultado não foi reproduzido no modelo de efeitos mistos lineares. Observou-se fraca correlação (%) entre os valores da reserva microvascular isquêmica periférica e níveis de lactato (mmol/L) nas primeiras 24 horas (r = 0,23; p < 0,05). Conclusão: O valor prognóstico da alta reserva microvascular isquêmica periférica foi confirmado no contexto da hiperlactatemia persistente induzida por sepse. Embora tenha sido observada uma baixa correlação positiva entre os valores da reserva microvascular isquêmica periférica e os níveis de lactato nas primeiras 24 horas do diagnóstico de sepse, o grupo com baixa reserva microvascular isquêmica periférica pareceu apresentar redução mais rápida do lactato nas 48 horas de seguimento.

An analysis of lactate/albumin, procalcitonin/albumin, and blood urea nitrogen/albumin ratios as a predictor of mortality in uroseptic patients

SUMMARY OBJECTIVE: The aim of this study was to investigate the ratios of lactate/albumin, procalcitonin/albumin, and blood urea nitrogen/albumin to predict 14- and 28-day mortality in uroseptic patients. Urosepsis is a disease with high mortality, and early diagnosis and treatment are important. METHODS: Patients with urosepsis who were admitted to the intensive care unit between January 2021 and September 2022, had a follow-up of at least 28 days, and met the inclusion criteria were evaluated retrospectively. RESULTS: The mean age was 70.23 (15.66) years and 84 (53.85%) were males. The number of non-survivors were 75 (48%) in the 14-day mortality group and 97 (62.1%) in the 28-day mortality group. Based on the 14-day mortality data, the blood urea nitrogen/albumin ratio was higher in non-survivors vs. survivors (median, 15.88 vs. 9.62), and the lactate/albumin ratio was higher (median, 0.96 vs. 0.52, p<0.01, all). Based on the 28-day mortality data, the blood urea nitrogen/albumin ratio was higher in non-survivors vs. survivors (median, 14.78 vs. 8.46), and the lactate/albumin ratio was higher (median, 0.90 vs. 0.50, p<0.01, all). CONCLUSION: It is very difficult to determine the prognosis of patients admitted to the emergency department with the diagnosis of urosepsis. The lactate/albumin ratio and the blood urea nitrogen/albumin ratio can be used as early prognostic markers for both 14-day and 28-day mortality until more reliable markers are identified.

Immunoexpression profile of hypoxia-inducible factor (HIF) targets in potentially malignant and malignant oral lesions: a pilot study

Abstract Oral potentially malignant disorders (OPMD) are associated with an increased risk of oral squamous cell carcinoma (OSCC). OSCC has an aggressive profile and is the most prevalent among different head and neck malignancies. Most OSCC patients are diagnosed with advanced stage tumors and have a poor prognosis. Cancer cells are able to reprogram their metabolism, even in the presence of oxygen, enhancing the conversion of glucose to lactate via the glycolytic pathway, a phenomenon mainly regulated by hypoxia-inducible factor (HIF) signaling. Thus, several glycometabolism-related biomarkers are upregulated. Objectives This study aimed to evaluate the immunoexpression of the HIF targets GLUT1, GLUT3, HK2, PFKL, PKM2, pPDH, LDHA, MCT4, and CAIX in OPMD and OSCC samples, in order to identify potential correlations between biomarkers' immunoexpression, clinicopathological features, and prognostic parameters. Methodology OSCC and OPMD samples from 21 and 34 patients (respectively) were retrospectively collected and stained for the different biomarkers by immunohistochemistry. Results CAIX and MCT4 expressions were significantly higher in OSCC samples when compared with OPMD samples, while the rest were also expressed by OPMD. GLUT3 and PKM2 alone, and the concomitant expression of more than four glycometabolism-related biomarkers were significantly correlated with the presence of dysplasia in OPMD. When considering OSCC cases, a trend toward increased expression of biomarkers and poor clinicopathological features was observed, and the differences regarding HK2, PFKL, LDHA and MCT4 expression were significant. Moreover, HK2 and CAIX were correlated with low survival rates. GLUT1 and GLUT3 were significantly associated with poor outcome when their expression was observed in the hypoxic region of malignant lesions. Conclusion OPMD and OSCC cells overexpress glycolysis-related proteins, which is associated with aggressive features and poor patient outcome. Further research is needed to deeply understand the glycolic phenotype in the process of oral carcinogenesis.

Effect of Lactate on Immune Cells in Tumor Microenvironment and Progress of Related Target Therapy / 肿瘤防治研究

The relationship between tumor metabolism and immunity is complex and diverse. To date, the role of tumor-specific metabolic reprogramming in shaping the specific tumor microenvironment in tumor immunotherapy remains unclear. Lactic acid is the main product of glycolysis, and the aerobic glycolysis of tumor cells causes lactic acid to accumulate in the microenvironment. Recent studies have shown that the accumulation of lactic acid in the tumor microenvironment hinders anti-tumor immunity, especially affects the function, differentiation, and metabolism of immune cells, and participates in tumor immune escape, thus promoting tumor. This article reviews the effects of lactate accumulation in the tumor microenvironment on dendritic cells, T cells, NK cells, tumor-associated macrophages, and myeloid-derived suppressor cells. Targeted intervention of lactate production and efflux by tumor cells is expected to become a new strategy for tumor immunotherapy.

Predictive value of serum lactate dehydrogenase on prognosis of patients with paraquat poisoning / 中华劳动卫生职业病杂志

Objective: To investigate the predictive value of serum lactate dehydrogenase (LDH) in the prognosis of patients with paraquat (PQ) poisoning, and to provide evidence for early prognosis assessment. Methods: In February 2022, 50 patients with PQ poisoning who completed serum LDH detection admitted to the Department of Emergency Medicine, the First Affiliated Hospital of Wenzhou Medical University from January 2012 to December 2021 were selected as the observation group, and 50 healthy physical examination personnel were randomly selected as the control group. Patients with PQ poisoning were divided into survival group and death group according to the prognosis, and the differences of blood routine routine, liver and kidney function and other indicators in the first admission between the two groups were compared. Multivariate logisitic regression model was established, ROC curve was drawn, and the influencing factors of prognosis of patients with PQ poisoning were analyzed. Results: Compared with the control group, the white blood cell count (WBC), total bilirubin (TBil), alanine aminotransferase (ALT), aspartate aminotransferase (AST), LDH, glucose (GLU) and creatinine (Cr) in observation group were significantly increased, while albumin (ALB) and total cholesterol (TC) were significantly decreased (P<0.05). Univariate analysis showed that WBC, elevated LDH (>247 U/L), TBil, ALT, AST and Cr were significantly different between PQ poisoning survival group and death group (P<0.05). Multivariate logisitic regression analysis showed that elevated serum LDH was an independent risk factor for the prognosis of PQ poisoning patients (OR=9.95, 95%CI: 1.34-73.82, P=0.025). The area under the ROC curve of LDH was 0.811 (95%CI: 0.692-0.930). When the cut-off value was 340 U/L, the sensitivity was 0.889 and the specificity was 0.719. Log-rank test showed that there was a statistically significant difference in survival rate between the normal LDH group and the elevated LDH group (P=0.001) . Conclusion: Serum LDH has a good predictive value in evaluating the prognosis of patients with PQ poisoning. Elevated LDH is a risk factor for poor prognosis of patients with PQ poisoning.

Effects of Cytokines on Early Death in Patients with Newly Diagnosed Acute Promyelocytic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of cytokine levels on early death and coagulation function of patients with newly diagnosed acute promyelocytic leukemia (APL).@*METHODS@#Routine examination was performed on 69 newly diagnosed APL patients at admission. Meanwhile, 4 ml fasting venous blood was extracted from the patients. And then the supernatant was taken after centrifugation. The concentrations of cytokines, lactate dehydrogenase (LDH) and ferritin were detected by using the corresponding kits.@*RESULTS@#It was confirmed that cerebral hemorrhage was a major cause of early death in APL patients. Elevated LDH, decreased platelets (PLT) count and prolonged prothrombin time (PT) were high risk factors for early death (P <0.05). The increases of IL-5, IL-6, IL-10, IL-12p70 and IL-17A were closely related to the early death of newly diagnosed APL patients, and the increases of IL-5 and IL-17A also induced coagulation disorder in APL patients by prolonging PT (P <0.05). In newly diagnosed APL patients, ferritin and LDH showed a positive effect on the expression of IL-5, IL-10 and IL-17A, especially ferritin had a highly positive correlation with IL-5 (r =0.867) and IL-17A (r =0.841). Moreover, there was a certain correlation between these five high-risk cytokines, among which IL-5 and IL-17A (r =0.827), IL-6 and IL-10 (r =0.823) were highly positively correlated.@*CONCLUSION@#Elevated cytokine levels in newly diagnosed APL patients increase the risk of early bleeding and death. In addition to the interaction between cytokines themselves, ferritin and LDH positively affect the expression of cytokines, thus affecting the prognosis of APL patients.

The effect of tumor-associated macrophage on proliferation of renal carcinoma cells and related mechanism / 中华泌尿外科杂志

Objective:To investigate the effect of tumor-associated macrophage(TAM) on proliferation of renal carcinoma cells and its related mechanism.Methods:The model of TAM was established by stimulating human monocytic leukemia cell line THP-1 with phorbol myristate acetate (PMA), bacterial endotoxin (LPS) and interferon-γ (IFN- γ). Then the TAM model was co-cultured with carcinoma cell lines ACHN and 786-O in vitro .The cytokines IL-6, TNF-α and IL-1β in TAM supernatant were detected by enzyme-linked immunosorbent assay (ELISA). MTT method was used to detect the proliferation of ACHN and 786-O cells treated with supernatant of TAM or TAM/Tocilizumab. Western blot was used to detect lactate dehydrogenase A (LDHA) expression of both renal cancer cells co-cultured with TAM or TAM/Tocilizumab. The ACHN and 786-O cells with LDHA-overexpression and LDHA-knockdown were cultured in TAM supernatant in vitro. The cell proliferation was detected by MTT and the relative proliferation rate was calculated.Results:THP-1 cells was differentiated into TAM through the treatment of 80 ng/ml PMA combined with 20 ng/ml LPS and 20 ng/ml IFN- γ.The expression rate of CD68, a cell surface marker on TAM, was (36.2 ±4.5)%. When TAM was co-cultured with ACHN cells, the results of ELISA showed that the secretion of IL-6 in the supernatant was significantly elevated compared with that in the supernatant when ACHN cells cultured alone [(138.0 ±12.4) pg/ml and (19.7±4.9) pg/ml], and the secretion of TNF- α [(122.5 ±14.2) pg/ml and (12.6 ±2.3) pg/ml] and IL-1 β [(89.2 ±6.4) pg/ml and (69.2 ±3.5) pg/ml] were also significantly increased. The secretion of IL-6 [(119.2 ±14.8) pg/ml and (17.1 ±3.3) pg/ml], TNF- α [(122.6 ±14.4) pg/ml and (45.7 ±7.2) pg/ml] and IL-1 β [(95.1 ±11.8) pg/ml and (88.2 ±12.7) pg/ml] in the supernatant were also significantly elevated when 786-O cells co-cultured with TAM compared with 786-O cells cultured alone. After treated with the supernatant of TAM for 72 hours, the relative proliferation rates of ACHN and 786-O cells [(128.6 ±21.4)% and (124.2 ±19.7)%] were significantly higher than that of the control group (100.0%). At the same time, the expression of LDHA in ACHN and 786-O cells increased significantly. After 72 hours of treatment with the supernatant of TAM combined with tocilizumab, the relative proliferation rates of ACHN and 786-O cells [(76.5±13.7)% and (74.8±12.5)%] were significantly lower than that of the control group(100.0%), and the expression of LDHA was also significantly decreased at the same time. The relative proliferation rates of ACHN and 786-O cells in LDHA overexpression group [(121.5 ±17.2)% and (122.7±21.6)%]were significantly higher than that in blank-vector-transfection group[(93.3±10.7)% and (89.8±11.2)%], while the relative proliferation rates in LDHA-knockdown group [(61.4±11.2)% and (58.0 ±10.6)% ]were significantly lower than that in blank-vector-transfection group.Conclusions:By secreting IL-6, TAM can up-regulate the expression of LDHA and promote the proliferation of renal cancer cells.