Predictive value of exhaled nitric oxide and aerobic capacity for sepsis complications after liver transplantation

Our objective was to investigate the predictive value of fractional nitric oxide (NO) concentration in exhaled breath (FeNO) and aerobic capacity (peak VO₂) for postoperative sepsis in liver transplantation candidates. Patients were identified and charts of all consecutive patients were prospectively reviewed. Bacterial sepsis represented the commonest postoperative complications (30%), which was attributed to peritonitis, pneumonia, and catheter‐related infections. Preoperative FeNO and peak VO₂ values were lower in patients with postoperative sepsis. Patients with sepsis required higher needs for mechanical ventilation and ICU length of stay. Inverse correlation was found between logarithmically FeNO‐transformed data and systolic pulmonary artery pressure (r = ?0.348; P = 0.018). Multivariate analyses using bootstrap sampling method indicated that odds of sepsis were associated with lower values of peak exercise VO₂ [OR = 0.790 (0.592; 0.925)] and reduced log(FeNo) [OR = 0.027 (0.001; 0.451)], but not with higher MELD scores [OR = 1.141 (0.970; 1.486)]. By evaluating the cutoff for the ROC curves in each bootstrap resampling, median and 95% confidence interval were calculated for peak VO₂: 17 [16.2; 22] ml/kg/min and FeNO: 17.2 [13.0; 33.9] ppb. We conclude that low peak exercise VO₂ and reduced FeNO may help identify patients who are at risk to develop perioperative sepsis.     

缺氧对前列腺癌细胞糖酵解及迁移侵袭能力的影响

目的  探讨缺氧状态下前列腺癌细胞糖酵解和体外迁移侵袭能力的改变。方法  将前列腺癌细胞DU145和/或PC-3分别置于常氧及缺氧环境中培养24和48 h,侵袭小室实验检测前列腺癌细胞体外迁移及侵袭能力改变。分别检测上清液中葡萄糖含量、乳酸含量;实时定量逆转录-聚合酶链反应（qRT-PCR）检测糖酵解相关基因的表达改变。结果  前列腺癌细胞DU145经缺氧处理后,体外迁移及侵袭能力较常氧处理增强。同时缺氧处理后,DU145和PC-3细胞培养上清液中葡萄糖含量减少,肿瘤细胞摄入葡萄糖能力提高,糖酵解代谢产物乳酸在上清液中增加。qRT-PCR结果表明,缺氧处理后DU145细胞糖酵解相关基因。结论  缺氧处理能增强前列腺癌细胞的体外迁移及侵袭能力,同时通过改变糖酵解相关基因的表达,对前列腺癌细胞的糖酵解过程发挥调控作用。

     

精脒对SW620细胞增殖及糖酵解的影响

目的 探讨精脒对人结肠癌SW620细胞增殖及糖酵解的影响.方法 以SW620细胞为研究对象,用0.625～2.5 μmoL/L精脒(SPD)作用于细胞,细胞密度以104个/mL接种于96孔培养板,分别培养24 h后,MTT法检测细胞增殖情况;同时,取6孔板培养24 h的细胞上清液,用试剂盒检测SW620细胞葡萄糖消耗及乳酸水平;细胞密度以1.2× 105个/mL接种于6孔培养板中,培养24 h后加入不同浓度SPD,继续培养24 h后,Western blot检测缺氧诱导因子(HIF-1)、乳酸脱氢酶(LDHA)及葡萄糖转运蛋白1(GLUT1)表达的变化.结果 与对照组比较,精脒各浓度组均能促进SW620细胞的增殖(P＜0.01),且促进作用呈剂量依赖性;精脒各浓度组作用后SW620细胞内葡萄糖的消耗及乳酸含量明显增多(P＜0.01),呈剂量依赖性;与对照组比较,LDHA、HIF-1及GLUT1蛋白表达水平随着精脒浓度的升高而增加(P＜0.01),且呈剂量依赖性.结论 精脒具有促进人结肠癌SW620细胞增殖及糖酵解的作用.     

Mechanisms of toxicity associated with six tyrosine kinase inhibitors in human hepatocyte cell lines

Tyrosine kinase inhibitors have revolutionized the treatment of certain cancers. They are usually well tolerated, but can cause adverse reactions including liver injury. Currently, mechanisms of hepatotoxicity associated with tyrosine kinase inhibitors are only partially clarified. We therefore aimed at investigating the toxicity of regorafenib, sorafenib, ponatinib, crizotinib, dasatinib and pazopanib on HepG2 and partially on HepaRG cells. Regorafenib and sorafenib strongly inhibited oxidative metabolism (measured by the Seahorse‐XF24 analyzer) and glycolysis, decreased the mitochondrial membrane potential and induced apoptosis and/or necrosis of HepG2 cells at concentrations similar to steady‐state plasma concentrations in humans. In HepaRG cells, pretreatment with rifampicin decreased membrane toxicity (measured as adenylate kinase release) and dissipation of adenosine triphosphate stores, indicating that toxicity was associated mainly with the parent drugs. Ponatinib strongly impaired oxidative metabolism but only weakly glycolysis, and induced apoptosis of HepG2 cells at concentrations higher than steady‐state plasma concentrations in humans. Crizotinib and dasatinib did not significantly affect mitochondrial functions and inhibited glycolysis only weakly, but induced apoptosis of HepG2 cells. Pazopanib was associated with a weak increase in mitochondrial reactive oxygen species accumulation and inhibition of glycolysis without being cytotoxic. In conclusion, regorafenib and sorafenib are strong mitochondrial toxicants and inhibitors of glycolysis at clinically relevant concentrations. Ponatinib affects mitochondria and glycolysis at higher concentrations than reached in plasma (but possibly in liver), whereas crizotinib, dasatinib and pazopanib showed no relevant toxicity. Mitochondrial toxicity and inhibition of glycolysis most likely explain hepatotoxicity associated with regorafenib, sorafenib and possibly pazopanib, but not for the other compounds investigated.     

两种运动心率监测器比较研究

用国产运动心率监测显示器(Exercise Heart Rate Monitor简称EHRM—I型)和芬兰产Polar心率监测仪同时对2名健康青年作多种不同负荷的动态心率测试,结果证实国产机在监测低到中等强度负荷的运动时的心率,其灵敏度及准确性均能与进口仪器相比.用EHRM—Ⅰ型作8名健康对象的静态心率测试,同时与手测搭脉方法对照,结果显示该仪器在显示静态心率数有很好的准确性.说明EHRM—I型有较好的工作性能.     

Müller细胞在视网膜糖酵解作用机制中的研究进展

糖酵解是生物通过在细胞内对糖的分解代谢获取部分能量的一种途径,视网膜的病理性改变多与能量代谢相关,视网膜Müller细胞是正常视网膜功能及几乎所有形式的视网膜损伤和疾病的参与者,Müller细胞在调控视网膜病变的病理过程中与糖酵解前体代谢产物之间有着密切关系。本文就视网膜及其Müller细胞与糖酵解前体代谢产物的作用机制进行归纳总结,为视网膜病变的治疗提供新的研究思路。     

Effect of Beetroot Juice Supplementation on Aerobic Response during Swimming

The beneficial effects of beetroot juice supplementation (BJS) have been tested during cycling, walking, and running. The purpose of the present study was to investigate whether BJS can also improve performance in swimmers. Fourteen moderately trained male master swimmers were recruited and underwent two incremental swimming tests randomly assigned in a pool during which workload, oxygen uptake (VO₂), carbon dioxide production (VCO₂), pulmonary ventilation (VE), and aerobic energy cost (AEC) of swimming were measured. One was a control swimming test (CSW) and the other a swimming test after six days of BJS (0.5l/day organic beetroot juice containing about 5.5 mmol of NO₃⁻). Results show that workload at anaerobic threshold was significantly increased by BJS as compared to the CSW test (6.3 ± 1 and 6.7 ± 1.1 kg during the CSW and the BJS test respectively). Moreover, AEC was significantly reduced during the BJS test (1.9 ± 0.5 during the SW test vs. 1.7 ± 0.3 kcal·kg⁻¹·h⁻¹ during the BJS test). The other variables lacked a statistically significant effect with BJS. The present investigation provides evidence that BJS positively affects performance of swimmers as it reduces the AEC and increases the workload at anaerobic threshold.     

Bioenergetic medicine

Here we discuss a specific therapeutic strategy we call ‘bioenergetic medicine’. Bioenergetic medicine refers to the manipulation of bioenergetic fluxes to positively affect health. Bioenergetic medicine approaches rely heavily on the law of mass action, and impact systems that monitor and respond to the manipulated flux. Since classically defined energy metabolism pathways intersect and intertwine, targeting one flux also tends to change other fluxes, which complicates treatment design. Such indirect effects, fortunately, are to some extent predictable, and from a therapeutic perspective may also be desirable. Bioenergetic medicine-based interventions already exist for some diseases, and because bioenergetic medicine interventions are presently feasible, new approaches to treat certain conditions, including some neurodegenerative conditions and cancers, are beginning to transition from the laboratory to the clinic.

Linked Articles

This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue-8