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.

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.

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.

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.

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.

Effects of manipulating lactate dehydrogenase gene on metabolism of HEK-293 and production of human adenovirus / 生物工程学报

Reducing lactate accumulation has always been a goal of the mammalian cell biotechnology industry. When animal cells are cultured in vitro, the accumulation of lactate is mainly the combined result of two metabolic pathways. On one hand, glucose generates lactate under the function of lactate dehydrogenase A (LDHA); on the other hand, lactate can be oxidized to pyruvate by LDHB or LDHC and re-enter the TCA cycle. This study comprehensively evaluated the effects of LDH manipulation on the growth, metabolism and human adenovirus (HAdV) production of human embryonic kidney 293 (HEK-293) cells, providing a theoretical basis for engineering the lactate metabolism in mammalian cells. By knocking out ldha gene and overexpression of ldhb and ldhc genes, the metabolic efficiency of HEK-293 cells was effectively improved, and HAdV production was significantly increased. Compared with the control cell, LDH manipulation promoted cell growth, reduced the accumulation of lactate and ammonia, significantly enhanced the efficiency of substrate and energy metabolism of cells, and significantly increased the HAdV production capacity of HEK-293 cells. Among these LDH manipulation measures, ldhc gene overexpression performed the best, with the maximum cell density increased by about 38.7%. The yield of lactate to glucose and ammonia to glutamine decreased by 33.8% and 63.3%, respectively; and HAdV titer increased by at least 16 times. In addition, the ATP production rate, ATP/O2 ratio, ATP/ADP ratio and NADH content of the modified cell lines were increased to varying degrees, and the energy metabolic efficiency was significantly improved.

Relationship between lactate and alkali deficiency and blood transfusion therapy in patients with traumatic hemorrhagic shock / 中国输血杂志

【Objective】 To explore the effect of lactate and alkali deficiency on the need for red blood cell transfusion in emergency of patients with traumatic hemorrhagic shock. 【Methods】 A total of 126 patients with traumatic hemorrhagic shock in our hospital from January 2019 to December 2021 were retrospectively analyzed, and the 99 cases with effective treatment were divided into two groups according to the outcome of blood transfusion within 24 hours after admission: non-transfusion group (n=36) and transfusion group (n=63). The changes of lactic acid (Lac), alkali deficiency (BE), hemoglobin (Hb), hematocrit (Hct) at admission, hemoglobin (Hb), hematocrit (Hct) 24 hours after admission and the length of stay in ICU were compared between the two groups. The binary logistic regression was used to analyze the risk factors of whether there was a need for blood transfusion at the time of emergency admission. The correlation between individual and combined indicators of each risk factor and the need for blood transfusion were analyzed by the receiver operating curve (ROC). 【Results】 The mean level of Lac (2.90±1.82) in the non-transfusion group at admission was lower than that in the transfusion group (5.80±2.83) (P0.05)The maximum AUG of Lac and BE(0.875, 0.766) in predicting the need for emergency red blood cell transfusion in patients with traumatic hemorrhagic shock was significantly better than that of Hb and Hct (0.692, 0.682); the optimal threshold for Lac was >3.6 mmol/L, while the optimal threshold for Hb is ≤106 g/L; the maximum AUG obtained by ROC curve analysis combined with Lac, BE, Hb and Hct was 0.910, which was higher than that of the sole virable. Comparative predictive value using the optimal thresholds of Lac and Hb as indications for transfusion showed that Lac had better predictive value than Hb. 【Conclusion】 Lac and be can be instructive for patients with traumatic hemorrhagic shock as to whether they need red blood cell transfusion in an emergency setting, and combination of Lac, BE, Hb and Hct may help to determine the transfusion needs of patients more timely and accurately and optimize the transfusion management of emergency patients.

Metabolic regulation of exogenous lactate on obese mice induced by high fat diet / 中国药科大学学报

@#This study investigates the metabolic regulatory effects of exogenous lactate on obesity mice induced by high-fat diet.We established obesity and metabolic disorder C57 mice model using a synthetic high-fat forage containing 60% fat.Some mice were fed with high-fat diet for 4 weeks to establish the model, being given 500 mg/(kg?d) lactate with ip for 4 weeks at the same time; the others were fed with high-fat diet for 8 weeks to establish the model, being given 500 mg/(kg?d) lactate 4 weeks after 4 weeks of modeling.During the trial period, the change of body weight and food intake, as well as serum glucose, lactate, triglycerides, insulin, and liver glycogen levels of both groups of mice were measured.Oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were used to assess glucose metabolism and insulin resistance in the body.At the end of the experiment, adipose tissue was dissected for weighing and histopathological examination.The expression of lipid synthesis and lipolysis genes in adipose tissue was detected by real-time PCR.The results showed that: (1) in the 4-week preventive medication trial, lactate had no significant effect on the body weight of normal and high-fat diet (HFD) mice, yet it increased the subcutaneous fat/visceral fat weight ratio; lactate could significantly reduce fasting blood glucose and liver glycogen levels in HFD mice while increasing blood lactate levels, significantly improving impaired glucose tolerance in HFD mice; lactate could improve the size and arrangement of adipocytes in the HFD group while significantly down-regulating the expression of fatty acid synthesis and lipolysis genes in adipose tissue; (2) in the 8-week treatment, both routes of lactate administration could partially reduce body weight in HFD group mice and reduce food intake, with the improvement trend for fat weight; both routes of lactate administration could significantly reduce fasting blood glucose levels in HFD mice, while significantly improving glucose and insulin tolerance, with some improvement of fasting insulin levels and insulin resistance index; both routes of lactate administration showed different degrees of improvement effect on adipocyte morphology in obese mice while significantly down-regulating lipolysis gene expression in adipose tissue.Therefore, for high-fat diet-induced obese mice with metabolic imbalance, exogenous lactate can stimulate glucose metabolism, inhibit adipose tissue lipolysis, and prevent adipocyte hypertrophy, thereby improving glucose tolerance and insulin sensitivity and reducing sugar-lipid metabolic disorder.

Effect of Liangfang Wenjing Decoction on expression of key glycolytic enzymes in uterus and ovaries of rats with coagulating cold and blood stasis syndrome / 中国中药杂志

This study aimed to investigate the relationship between coagulating cold and blood stasis syndrome and glycolysis, and observe the intervention effect of Liangfang Wenjing Decoction(LFWJD) on the expression of key glycolytic enzymes in the uterus and ovaries of rats with coagulating cold and blood stasis. The rat model of coagulating cold and blood stasis syndrome was established by ice-water bath. After modeling, the quantitative scoring of symptoms were performed, and according to the scoring results, the rats were randomly divided into a model group and LFWJD low-, medium-and high-dose groups(4.7, 9.4, 18.8 g·kg~(-1)·d~(-1)), with 10 in each group. Another 10 rats were selected as the blank group. After 4 weeks of continuous administration by gavage, the quantitative scoring of symptoms was repeated. Laser speckle flowgraphy was used to detect the changes of microcirculation in the ears and uterus of rats in each group. Hematoxylin-eosin(HE) staining was used to observe the pathological morphology of uterus and ovaries of rats in each group. The mRNA and protein expressions of pyruvate dehydrogenase kinase 1(PDK1), hexokinase 2(HK2) and lactate dehydrogenase A(LDHA) in the uterus and ovaries of rats were examined by real-time quantitative polymerase chain reaction(RT-qPCR) and Western blot, respectively. The rats in the model group showed signs of coagulating cold and blood stasis syndrome, such as curl-up, less movement, thickened veins under the tongue, and reduced blood perfusion in the microcirculation of the ears and uterus, and HE staining revealed a thinning of the endometrium with disorganized arrangement of epithelial cells and a decrease in the number of ovarian follicles. Compared with the model group, the treatment groups had alleviated coagulating cold and blood stasis, which was manifested as red tongue, reduced nail swelling, no blood stasis at the tail end as well as increased blood perfusion of the microcirculation in the ears and uterus(P<0.05 or P<0.01). Among the groups, the LFWJD medium-and high-dose groups had the most significant improvement in coagulating cold and blood stasis, with neatly arranged columnar epithelial cells in uterus, and the number of ovarian follicles was higher than that in the model group, especially mature follicles. The mRNA and protein expressions of PDK1, HK2, LDHA in uterus and ovaries were up-regulated in the model group(P<0.05 or P<0.01), while down-regulated in LFWJD medium-and high-dose groups(P<0.05 or P<0.01). The LFWJD low-dose group presented a decrease in the mRNA expressions of PDK1, HK2 and LDHA in uterus and ovaries as well as in the protein expressions of HK2 and LDHA in uterus and HK2 and PDK1 in ovaries(P<0.05 or P<0.01). The therapeutic mechanism of LFWJD against coagulating cold and blood stasis syndrome is related to the down-regulation of key glycolytic enzymes PDK1, HK2 and LDHA, and the inhibition of glycolytic activities in uterus and ovaries.

Lactate-induced up-regulation of PLEKHA4 promotes proliferation and apoptosis of human glioma cells / 南方医科大学学报

OBJECTIVE@#To investigate the effect of lactic acid-induced upregulation of PLEKHA4 expression on biological behaviors of glioma cells and the possible molecular mechanism.@*METHODS@#GEO database and GEPIA2 website were used to analyze the relationship between PLEKHA4 expression level and the pathological grade of glioma. A specific PLEKHA4 siRNA was transfected in glioma U251 and T98G cells, and the changes in cell proliferation ability were assessed by real-time cell analysis technology and Edu experiment. The colony-forming ability of the cells was evaluated using plate cloning assay, and cell cycle changes and cell apoptosis were analyzed with flow cytometry. The mRNA expression of PLEKHA4 was detected by PCR in glioma samples and controls and in glioma cells treated with lactic acid and glucose. Xenograft mice in vivo was used to detect tumor formation in nude mice; Western blotting was used to detect the expressions of cyclinD1, CDK2, Bcl2, β-catenin and phosphorylation of the key proteins in the MAPK signaling pathway.@*RESULTS@#The results of GEO database and online website analysis showed that PLEKHA4 was highly expressed in glioma tissues and was associated with poor prognosis; PLEKHA4 knockdown obviously inhibited the proliferation and attenuated the clone-forming ability of the glioma cells (P < 0.05). Flow cytometry showed that PLEKHA4 knockdown caused cell cycle arrest in G1 phase and promoted apoptosis of the cells (P < 0.01). PLEKHA4 gene mRNA expression was increased in glioma samples and glioma cells after lactate and glucose treatment (P < 0.01). PLEKHA4 knockdown, tumor formation ability of nude mice decreased; PLEKHA4 knockdown obviously lowered the expression of cyclinD1, CDK2, Bcl2 and other functional proteins, inhibited the phosphorylation of ERK and p38 and reduced the expression of β-catenin protein (P < 0.01).@*CONCLUSION@#PLEKHA4 knockdown inhibited the proliferation of glioma cells and promoted apoptosis by inhibiting the activation of the MAPK signaling pathway and expression of β-catenin. Lactic acid produced by glycolysis upregulates the expression of PLEKHA4 in glioma cells.

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.

Predictive value of Pcv-aCO 2 on left ventricular ejection fraction in myocardial infarction / 中华急诊医学杂志

Objective:To investigate the relationship between central venous-arterial blood carbon dioxide partial pressure difference (Pcv-aCO 2) and left ventricular ejection fraction(LVEF) in acute myocardial infarction. Methods:Clinical data of patients with acute myocardial infarction admitted to the Intensive Care Unit of Fujian Provincial Hospital from November 2019 to October 2021 were retrospectively analyzed. LVEF was measured by bedside echocardiogram. The patients were divided into the normal LVEF group (LVEF ≥ 52%) and decreased LVEF group (LVEF < 52%) according to LVEF. The differences in general information and hemodynamic parameters between the two groups were compared. The normality of the above data was tested by the Jarque-Bera test. Correlation analysis of hemodynamic indices with LVEF was performed. Binary logistic regression was used to analyze the risk factors associated with the decrease in LVEF. The feasibility of diagnosing LVEF decline with Pcv-aCO 2 was assessed using receiver operating characteristic (ROC) curve. Results:Seventy-two patients with acute myocardial infarction were included for analysis, including 25 patients in the normal LVEF group and 47 patients in the decreased LVEF group. Pcv-aCO 2 was significantly higher in the decreased LVEF group than that in the normal LVEF group [(7.13±1.19) mmHg vs. (5.41±1.23) mmHg, P<0.01]. There was a negative correlation between LVEF and Pcv-aCO 2 ( rs= -0.740, P<0.01). The area under the ROC curve for Pcv-aCO 2 was 0.849 (95% CI: 0.758-0.939, P<0.01). The binary logistic regression analysis showed that Pcv-aCO 2 was an independent risk factor for decreased LVEF ( OR=2.251, 95% CI: 1.326-3.820). Conclusions:To a certain extent, the increase of Pcv-aCO 2 can predict the decrease of LVEF in acute myocardial infarction.