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.

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.

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.

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.

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 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.

Research progress on the impact of lactate clearance rate on the prognosis of critically ill patients / 中国医师杂志

Lactic acid is one of the main metabolites in the body, and its clearance rate reflects the dynamic changes of lactic acid in the body. Recent studies have shown that lactate clearance rate is related to the prognosis of critically ill patients with sepsis/septic shock, cardiogenic shock, out-of-hospital cardiac arrest, postoperative cardiovascular surgery, and liver and kidney dysfunction. This article reviews the relevant research progress of lactate metabolism and lactate clearance rate in different critically ill patients.

Predictive value of Pv-aCO 2/Ca-vO 2 combined blood lactate concentration for primary peritonitis-related septic shock in children / 中华危重病急救医学

Objective:To investigate the prognostic value of the ratio of veno-arterial carbon dioxide partial pressure difference to arterio-venous oxygen content difference (Pv-aCO 2/Ca-vO 2) in children with primary peritonitis-related septic shock. Methods:A retrospective study was conducted. Sixty-three children with primary peritonitis-related septic shock admitted to department of intensive care unit of the Children's Hospital Affiliated to Xi'an Jiaotong University from December 2016 to December 2021 were enrolled. The 28-day all-cause mortality was the primary endpoint event. The children were divided into survival group and death group according to the prognosis. The baseline data, blood gas analysis, blood routine, coagulation, inflammatory status, critical score and other related clinical data of the two groups were statistics. The factors affecting the prognosis were analyzed by binary Logistic regression, and the predictability of risk factors were tested by the receiver operator characteristic curve (ROC curve). The risk factors were stratified according to the cut-off, Kaplan-Meier survival curve analysis compared the prognostic differences between the groups.Results:A total of 63 children were enrolled, including 30 males and 33 females, the average age (5.6±4.0) years old, 16 cases died in 28 days, with mortality was 25.4%. There were no significant differences in gender, age, body weight and pathogen distribution between the two groups. The proportion of mechanical ventilation, surgical intervention, vasoactive drug application, and procalcitonin, C-reactive protein, activated partial thromboplastin time, serum lactate (Lac), Pv-aCO 2/Ca-vO 2, pediatric sequential organ failure assessment, pediatric risk of mortality Ⅲ in the death group were higher than those in the survival group. Platelet count, fibrinogen, mean arterial pressure were lower than those in the survival group, and the differences were statistically significant. Binary Logistic regression analysis showed that Lac and Pv-aCO 2/Ca-vO 2 were independent risk factors affecting the prognosis of children [odds ratio ( OR) and 95% confidence interval (95% CI) were 2.01 (1.15-3.21), 2.37 (1.41-3.22), respectively, both P < 0.01]. ROC curve analysis showed that the area under curve (AUC) of Lac, Pv-aCO 2/Ca-vO 2 and their combination were 0.745, 0.876 and 0.923, the sensitivity were 75%, 85% and 88%, and the specificity were 71%, 87% and 91%, respectively. Risk factors were stratified according to cut-off, and Kaplan-Meier survival curve analysis showed that the 28-day cumulative probability of survival of Lac ≥ 4 mmol/L group was lower than that in Lac < 4 mmol/L group [64.29% (18/28) vs. 82.86% (29/35), P < 0.05]. Pv-aCO 2/Ca-vO 2 ≥ 1.6 group 28-day cumulative probability of survival was less than Pv-aCO 2/Ca-vO 2 < 1.6 group [62.07% (18/29) vs. 85.29% (29/34), P < 0.01]. After a hierarchical combination of the two sets of indicator variables, the 28-day cumulative probability of survival of Pv-aCO 2/Ca-vO 2 ≥ 1.6 and Lac ≥ 4 mmol/L group significantly lower than that of the other three groups (Log-rank test, χ2 = 7.910, P = 0.017). Conclusion:Pv-aCO 2/Ca-vO 2 combined with Lac has a good predictive value for the prognosis of children with peritonitis-related septic shock.

Predictive value of early lactate/albumin ratio in the prognosis of sepsis / 中华危重病急救医学

Objective:To investigate the prognostic value of early serum lactate, albumin, and lactate/albumin ratio (L/A) on the 28-day prognosis of adult patients with sepsis.Methods:A retrospective cohort study was conducted among adult patients with sepsis admitted to the First Affiliated Hospital of Xinjiang Medical University from January to December in 2020. Gender, age, comorbidities, lactate within 24 hours of admission, albumin, L/A, interleukin-6 (IL-6), procalcitonin (PCT), C-reactive protein (CRP) and 28-day prognosis were recorded. The receiver operator characteristic curve (ROC curve) was drawn to analyze the predictive value of lactate, albumin and L/A for 28-day mortality in patients with sepsis. Subgroup analysis of patients was performed according to the best cut-off value, Kaplan-Meier survival curves were drawn, and the 28-day cumulative survival of patients with sepsis was analyzed.Results:A total of 274 patients with sepsis were included, and 122 patients died at 28 days, with a 28-day mortality of 44.53%. Compared with the survival group, the age, the proportion of pulmonary infection, the proportion of shock, lactate, L/A and IL-6 in the death group were significantly increased, and albumin was significantly decreased [age (years): 65 (51, 79) vs. 57 (48, 73), pulmonary infection: 75.4% vs. 53.3%, shock: 37.7% vs. 15.1%, lactate (mmol/L): 4.76 (2.95, 9.23) vs. 2.21 (1.44, 3.19), L/A: 0.18 (0.10, 0.35) vs. 0.08 (0.05, 0.11), IL-6 (ng/L): 337.00 (97.73, 2 318.50) vs. 55.88 (25.26, 150.65), albumin (g/L): 27.68 (21.02, 33.03) vs. 29.62 (25.25, 34.23), all P < 0.05]. The area under the ROC curve (AUC) and 95% confidence interval (95% CI) of lactate, albumin, and L/A were 0.794 (95% CI was 0.741-0.840), 0.589 (95% CI was 0.528-0.647), 0.807 (95% CI was 0.755-0.852) for predicting 28-day mortality in sepsis patients. The optimal diagnostic cut-off value of lactate was 4.07 mmol/L, the sensitivity was 57.38%, the specificity was 92.76%. The optimal diagnostic cut-off value of albumin was 22.28 g/L, the sensitivity was 31.15%, the specificity was 92.76%. The optimal diagnostic cut-off of L/A was 0.16, the sensitivity was 54.92%, and the specificity was 95.39%. Subgroup analysis showed that the 28-day mortality of sepsis patients in the L/A > 0.16 group was significantly higher than that in the L/A ≤ 0.16 group [90.5% (67/74) vs. 27.5% (55/200), P < 0.001]. The 28-day mortality of sepsis patients in the albumin ≤ 22.28 g/L group was significantly higher than that in the albumin > 22.28 g/L group [77.6% (38/49) vs. 37.3% (84/225), P < 0.001]. The 28-day mortality in the group with lactate > 4.07 mmol/L was significantly higher than that in the group with lactate ≤ 4.07 mmol/L [86.4% (70/81) vs. 26.9% (52/193), P < 0.001]. The three were consistent with the analysis results of Kaplan-Meier survival curve. Conclusion:The early serum lactate, albumin, and L/A were all valuable in predicting the 28-day prognosis of patients with sepsis, and L/A was better than lactate and albumin.

Clinical efficacy of ateplase combined with heparin in the treatment of acute moderate- and high-risk pulmonary thromboembolism and its effects on arterial blood gas analysis and myocardial enzyme level / 中国基层医药

Objective:To investigate the clinical efficacy of alteplase combined with heparin in the treatment of acute moderate- and high-risk pulmonary thromboembolism and its effects on arterial blood gas analysis and myocardial enzyme level.Methods:Seventy-eight patients with acute moderate- and high-risk pulmonary thromboembolism who received treatment in Dongyang People's Hospital from January 2015 to January 2022 were retrospectively included in this study. They were divided into observation ( n = 39) and control ( n = 39) groups according to different treatment methods. The control group was treated with heparin, while the observation group was treated with alteplase based on heparin. All patients were treated for 7 days. Clinical efficacy as well as arterial blood gas analysis, myocardial enzymes, pulmonary artery pressure, and tricuspid annular plane systolic excursion pre- and post-treatment were compared between the two groups. Results:The total response rate in the observation group was significantly higher than that in the control group (94.87% vs. 76.92%, χ2 = 5.18, P < 0.05). After treatment, the partial pressure of carbon dioxide in the observation group was significantly lower than that in the control group [(36.24 ± 5.12) mmHg vs. (44.25 ± 3.78) mmHg, 1 mmHg = 0.133 kPa, t = 7.86, P < 0.05]. After treatment, the partial pressure of oxygen in the observation group was significantly higher than that in the control group [(78.82 ± 5.1) mmHg vs. (71.23 ± 4.89) mmHg, t = 6.66, P < 0.05]. After treatment, lactate dehydrogenase, creatine kinase, and creatine kinase isoenzyme in the observation group were (107.42 ± 15.45) U/L, (37.21 ± 10.84) U/L, and (12.28 ± 3.54) U/L, respectively, which were significantly lower than (189.94 ± 21.20) U/L, (65.42 ± 6.57) U/L, and (19.29 ± 3.08) U/L in the control group ( t = 19.64, 13.89, 9.33, all P < 0.001). After treatment, the pulmonary arterial pressure in the observation group was significantly lower than that in the control group [(32.24 ± 3.86) mmHg vs. (37.79 ± 5.17) mmHg, t = 5.37, P < 0.001]. Tricuspid annular plane systolic excursion in the observation group was significantly higher than that in the control group [(14.07 ± 1.27) mm vs. (12.63 ± 1.16) mm, t = 5.22, P < 0.001]. Conclusion:Ateplase combined with heparin has an obvious effect on acute moderate- and high-risk pulmonary thromboembolism. It can improve arterial blood gas analysis and reduce myocardial enzyme levels.

Inhibitory Effect of Sophora alopecuroides Total Alkaloids and Two Monomer Alkaloids on PC12 Cell Activity / 中国实验方剂学杂志

ObjectiveTo compare the effects of total alkaloids， matrine， and sophoridine extracted from Sophora alopecuroides on the activity of pheochromocytoma cells （PC12 cells）. MethodThe effect of S. alopecuroides total alkaloids， matrine， and sophoridine at concentrations of 2， 1， 0.5， 0.25， 0.125， and 0.062 5 g·L-1 on the proliferation of PC12 cells was evaluated using the 3-（4，5-dimethylthiazol-2-yl）-2，5-diphenyl tetrazolium bromide （MTT） assay. The lactate dehydrogenase （LDH） leakage rate was measured by enzyme-linked immunosorbent assay （ELISA）. Flow cytometry was used to assess cell apoptosis rate， cell cycle distribution， and intracellular Ca2+ levels. Real-time quantitative polymerase chain reaction （Real-time PCR） was performed to determine the mRNA transcription levels of B-cell lymphoma-2 （Bcl-2） and Bcl-2-associated X protein （Bax）. Protein expression levels of apoptosis-related proteins Caspase-3， Caspase-8， Bcl-2， and Bax were detected by Western blot. ResultCompared to the control group， S. alopecuroides total alkaloids， matrine， and sophoridine inhibited the proliferation of PC12 cells， increased LDH leakage rate， enhanced intracellular Ca2+ fluorescence intensity， and induced cell apoptosis in concentration-dependent manner （P<0.05， P<0.01）. Among them， S. alopecuroides total alkaloids had the strongest inhibitory effect on cell proliferation and induction of apoptosis in PC12 cells （P<0.01）. After treatment with S. alopecuroides total alkaloids， matrine， and sophoridine， the cell cycle progression of PC12 cells was arrested at G1/G0 in the S. alopecuroides total alkaloids group， and at G1/S in the matrine and sophoridine groups. The expression levels of Bax mRNA were significantly increased （P<0.05， P<0.01）， while the expression levels of Bcl-2 mRNA were significantly decreased （P<0.05， P<0.01）. All treatments significantly downregulated the expression of the anti-apoptotic protein Bcl-2 （P<0.05， P<0.01） and upregulated the expression of the pro-apoptotic proteins Bax， Caspase-3， and Caspase-8 （P<0.05， P<0.01）， with the most significant protein expression changes observed in the S. alopecuroides total alkaloids group. ConclusionAmong the S. alopecuroides total alkaloids， matrine， and sophoridine， S. alopecuroides total alkaloids exhibit the strongest inhibitory effect on the activity of PC12 cells， and its mechanism of action may be related to the inhibition of anti-apoptotic protein expression， upregulation of pro-apoptotic protein expression， and activation of the mitochondrial Caspase-8 apoptotic pathway.

Research progress on T cell glycolytic metabolism in oral lichen planus / 口腔疾病防治

@#Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa. The pathogenesis of OLP is still unclear. Immune abnormalities mediated by T cells and related cytokines play a crucial role in the pathogenesis of OLP. In recent years, glycolytic metabolism-related transporters, enzymes and regulators, such as glucose transporter-1 (Glut1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), lactate dehydrogenase A (LDHA), mammalian target of rapamycin (mTOR) and hypoxia inducible factor-1α (HIF-1a), have attracted an increasing amount of attention in OLP by regulating the proliferation and differentiation of T cells and the secretion of inflammatory factors. It has been shown that 2-deoxy-D-glucose (2-DG) or rapamycin (RAPA) inhibits the glycolytic metabolism of T cells and then inhibits OLP. This article reviews the research progress of glycolytic metabolism-related transporters, enzymes and regulatory factors in OLP in recent years.

Advances in research on mechanism of lactate dehydrogenase B in tumors / 中国药科大学学报

@#Increased glycolysis is a major feature of metabolic reprogramming in cancer.Glycolysis provides not only energy for cancer cells but also necessary precursors for biosynthesis, which is important for promoting tumor growth.Cancer cells meet their own needs by regulating glycolytic enzymes, which play an active role in promoting cancer survival, metastasis, and invasion.Lactate dehydrogenase (LDH), as a key enzyme in glycolysis, consists of two subunits: lactate dehydrogenase A (LDHA) and lactate dehydrogenase B (LDHB).LDHA is known to play a key role in aerobic glycolysis and has been extensively studied, whereas less has been done on LDHB.However, at present, more and more reports have revealed the important effects of LDHB on the progression of various cancers.A large number of studies have shown that LDHB is abnormally expressed in a variety of cancers, which is related to the malignant progression of tumors.The article reviews the research progress of LDHB in recent ten years, including its regulatory mechanism in tumor, its relationship with cancer development and its role as a biomarker in clinical diagnosis of cancer, which provides some insight for further investigation of the mechanism of LDHB in cancer research.

A metabolic intervention strategy to break evolutionary adaptability of tumor for reinforced immunotherapy

The typical hallmark of tumor evolution is metabolic dysregulation. In addition to secreting immunoregulatory metabolites, tumor cells and various immune cells display different metabolic pathways and plasticity. Harnessing the metabolic differences to reduce the tumor and immunosuppressive cells while enhancing the activity of positive immunoregulatory cells is a promising strategy. We develop a nanoplatform (CLCeMOF) based on cerium metal-organic framework (CeMOF) by lactate oxidase (LOX) modification and glutaminase inhibitor (CB839) loading. The cascade catalytic reactions induced by CLCeMOF generate reactive oxygen species "storm" to elicit immune responses. Meanwhile, LOX-mediated metabolite lactate exhaustion relieves the immunosuppressive tumor microenvironment, preparing the ground for intracellular regulation. Most noticeably, the immunometabolic checkpoint blockade therapy, as a result of glutamine antagonism, is exploited for overall cell mobilization. It is found that CLCeMOF inhibited glutamine metabolism-dependent cells (tumor cells, immunosuppressive cells, etc.), increased infiltration of dendritic cells, and especially reprogrammed CD8+ T lymphocytes with considerable metabolic flexibility toward a highly activated, long-lived, and memory-like phenotype. Such an idea intervenes both metabolite (lactate) and cellular metabolic pathway, which essentially alters overall cell fates toward the desired situation. Collectively, the metabolic intervention strategy is bound to break the evolutionary adaptability of tumors for reinforced immunotherapy.

Coordinated Regulation of Myelination by Growth Factor and Amino-acid Signaling Pathways / 神经科学通报·英文版

Myelin-forming oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS) are essential for structural and functional homeostasis of nervous tissue. Albeit with certain similarities, the regulation of CNS and PNS myelination is executed differently. Recent advances highlight the coordinated regulation of oligodendrocyte myelination by amino-acid sensing and growth factor signaling pathways. In this review, we discuss novel insights into the understanding of differential regulation of oligodendrocyte and Schwann cell biology in CNS and PNS myelination, with particular focus on the roles of growth factor-stimulated RHEB-mTORC1 and GATOR2-mediated amino-acid sensing/signaling pathways. We also discuss recent progress on the metabolic regulation of oligodendrocytes and Schwann cells and the impact of their dysfunction on neuronal function and disease.