Muscular cell proliferative and protective effects of N-acetylcysteine by modulating activity of extracellular signal-regulated protein kinase

N-acetylcysteine (NAC), an antioxidant and a precursor of glutathione, is currently in clinical use for various pathological conditions. No data is available as to the relationship between NAC and muscular cell proliferation or muscular degenerative disease. In this study, we assessed the effect of NAC on growth of L6 myoblasts, a rat skeletal muscle cell line, under normal or bupivacaine-treated condition. Of interest, under normal growth conditions, NAC treatment concentration-dependently increased viability, cell number, and DNA incorporation of L6 cells. Remarkably, NAC treatment for 12 to 24 h led to increased phosphorylation of ERKs, a family of mitogen-activated protein kinase known to involve in cell proliferation, in L6 cells, and specific inhibition of ERKs by PD98059, a selective inhibitor of ERKs, greatly abolished the ability of NAC to increase the number of L6 cells. More importantly, pretreatment with NAC effectively blocked decrease in the number and ERKs phosphorylation in L6 cells induced by the exposure of bupivacaine, a local anesthetic with myotoxicity. These results collectively suggest that NAC has muscular cell proliferative and protective effects and the effects by NAC appear to be, in part, mediated via increase in ERKs activation.     

腰麻硬膜外联合麻醉在老年下肢手术中的临床观察

目的:比较罗哌卡因、左旋布比卡因和布比卡因在老年患者下肢手术腰麻—硬膜外联合麻醉(combined spinal epidural anesthesia,CSEA)应用中的麻醉效果.方法:60例拟行下肢手术的老年患者随机分为罗哌卡因组、左旋布比卡因组和布比卡因组,每组各15例,均采用CSEA麻醉方法.比较各组感觉、运动麻醉阻滞情况,以及血流动力学变化.结果:罗哌卡因组麻醉效果不及其他两组,而布比卡因组与左旋布比卡因组间比较麻醉效果差异不明显;与其他两组比较,罗哌卡因组麻醉起效时间及最大运动阻滞时间均显著延长,而阻滞恢复时间明显缩短(P＜0.05或0.01),且Bromage评分及麻醉满意率低于布比卡因组(P＜0.05);罗哌卡因组与左旋布比卡因组患者循环系统稳定性优于布比卡因组.结论:腰麻—硬膜外联合麻醉中罗哌卡因、左旋布比卡因和布比卡因对于老年患者下肢手术均有较好的麻醉效果,其中罗哌卡因、左旋布比卡因对于心血管影响较小.     

布比卡因局部阻滞治疗输尿管结石所致肾绞痛60 例的临床观察

目的:比较药物治疗与布比卡因局部阻滞治疗输尿管上段结石所致的肾绞痛的临床疗效。方法:选择输尿管结石患者共120例。随机分成药物治疗组(M组)与局部阻滞组(B组)各60例,其中药物治疗组采用杜冷丁加阿托品治疗,局部阻滞组采用布比卡因行痛区局部阻滞,两组年龄、性别均无统计学差异,比较两组患者治疗的总有效率、不良反应、镇痛起效时间、缓解时间等疗效指标。结果:局部阻滞组治疗的总有效率大于药物治疗组,不良反应也比药物治疗组少。疼痛起效时间及缓解时间,局部阻滞组均明显短于药物治疗组。结论:布比卡因局部阻滞治疗输尿管上段结石所致的肾绞痛临床疗效明显优于以杜冷丁加阿托品为代表的药物治疗。     

布比卡因与左旋布比卡因在剖宫产手术中麻醉效果比较*

摘要目的：探讨蛛网膜下腔注射左旋布比卡因和布比卡因对剖宫产手术中的麻醉效果。方法：选取2012 年3 月到2013 年3 月 期间在我院住院进行剖宫产手术产妇60 例作为研究对象。随机分为左旋布比卡因组与布比卡因组,观察两组患者的麻醉效果以 及术后不良反应的发生情况。结果：剖宫产手术中左旋布比卡因和布比卡因的蛛网膜下腔注射麻醉后的5 min 和7 min 后MAP 值与麻醉前比较差异具有统计学意义（P<0.05）。左旋布比卡因和布比卡因的蛛网膜下腔注射麻醉后的5 min、7 min、10 min 以及 15minHR值比较差异具有统计学意义（P<0.05）。左旋布比卡因和布比卡因的蛛网膜下腔注射麻醉后Bromage 评分0分时间和麻 醉后切口感觉疼痛时间相比差异具有统计学意义（P<0.05）。左旋布比卡因和布比卡因麻醉后的不良反应的发生率比较差异无统 计学意义（P>0.05）。结论：剖宫产手术麻醉中布比卡因的麻醉效果好于左旋布比卡因,临床上剖宫产等腹部手术应该选择布比卡 因进行临床麻醉。     

Effects of levobupivacaine and bupivacaine on intracellular calcium signaling in cultured rat dorsal root ganglion neurons

Bupivacaine and levobupivacaine have been shown to be effective in the treatment of pain as local anesthetics, although the mechanisms mediating their antinociceptive actions are still not well understood. The aim of this study was to investigate the effects of bupivacaine and levobupivacaine on intracellular calcium ([Ca²⁺]_i) signaling in cultured rat dorsal root ganglion (DRG) neurons. DRG neuronal cultures loaded with 5?μM Fura-2/AM and [Ca²⁺]_i transients for stimulation with 30?mM KCl (Hi K⁺) were assessed by using fluorescent ratiometry. DRGs were excited at 340 and 380?nm, emission was recorded at 510?nm, and responses were determined from the change in the 340/380 ratio (basal-peak) for individual DRG neurons. Data were analyzed by using Student’s t-test. Levobupivacaine and bupivacaine attenuated the KCl-evoked [Ca²⁺]_i transients in a reversible manner. [Ca²⁺]_i increase evoked by Hi K⁺ was significantly reduced to 99.9?±?5.1% (n?=?18) and 62.5?±?4.2% (n?=?15, P?<?0.05) after the application of 5 and 50?µM levobupivacaine, respectively. Bupivacaine also inhibited Hi K⁺-induced [Ca²⁺]_i responses, reduced to 98.7?±?4.8% (n?=?10) and 69.5?±?4.5% (n?=?9, P?<?0.05) inhibition of fluorescence ratio values of Hi K⁺-induced responses at 5 and 50?μM, respectively. Our results indicate that bupivacaine and levobupivacaine, with no significant differences between both agents, attenuated KCl-evoked calcium transients in a reversible manner. The inhibition of calcium signals in DRG neurons by levobupivacaine and bupivacaine might contribute to the antinociceptive effects of these local anesthetics.     

iTRAQ proteomics analysis reveals that PI3K is highly associated with bupivacaine‐induced neurotoxicity pathways

Bupivacaine, a commonly used local anesthetic, has potential neurotoxicity through diverse signaling pathways. However, the key mechanism of bupivacaine‐induced neurotoxicity remains unclear. Cultured human SH‐SY5Y neuroblastoma cells were treated (bupivacaine) or untreated (control) with bupivacaine for 24 h. Compared to the control group, bupivacaine significantly increased cyto‐inhibition, cellular reactive oxygen species, DNA damage, mitochondrial injury, apoptosis (increased TUNEL‐positive cells, cleaved caspase 3, and Bcl‐2/Bax), and activated autophagy (enhanced LC3II/LC3I ratio). To explore changes in protein expression and intercommunication among the pathways involved in bupivacaine‐induced neurotoxicity, an 8‐plex iTRAQ proteomic technique and bioinformatics analysis were performed. Compared to the control group, 241 differentially expressed proteins were identified, of which, 145 were up‐regulated and 96 were down‐regulated. Bioinformatics analysis of the cross‐talk between the significant proteins with altered expression in bupivacaine‐induced neurotoxicity indicated that phosphatidyl‐3‐kinase (PI3K) was the most frequently targeted protein in each of the interactions. We further confirmed these results by determining the downstream targets of the identified signaling pathways (PI3K, Akt, FoxO1, Erk, and JNK). In conclusion, our study demonstrated that PI3K may play a central role in contacting and regulating the signaling pathways that contribute to bupivacaine‐induced neurotoxicity.     

High-performance liquid chromatographic separation and nanogram quantitation of bupivacaine enantiomers in blood

Chiral separation of rac-bupivacaine extracted from blood was achieved with similar limits of detection but using a much simpler sample preparation than reported previously. The simple one-step sample preparation devised was highly robust and efficient and allowed a very high throughput of samples. The high-performance liquid chromatography (HPLC) conditions used gave baseline separation of the enantiomers with high sensitivity. R-(+)-bupivacaine and S-(−)-bupivacaine blood concentrations were determined using a chiral stationary phase (AGP, ChromTech) with diode array detection at 220 nm; this wavelength produced a stable baseline allowing semi-automated analysis. Sample preparation involved addition of internal standard (diphenhydramine), basification of blood, extraction with n-hexane, concentration of the extract to dryness and reconstitution in 0.002 M phosphoric acid. At rac-bupivacaine concentrations of 0.5, 5 and 50 μg/ml in blood, assay accuracy as estimated by coefficients of variation (C.V.s), were 3.3, 1.4, and 1.6%, respectively, for R-(+)-bupivacaine and 3.7, 2.0 and 1.5%, respectively, for S-(−)-bupivacaine. Using 0.6-ml samples, the estimated limits of detection for R-(+)-bupivacaine and S-(−)-bupivacaine were both 15 ng/ml of blood. Calibration curves (n=188) were linear from 0.1 to 50 μg/ml with all correlation coefficients being greater than 0.99. This semi-automated method was applied to studies involving whole body pharmacokinetics with intravenous doses ranging from 12.5 to 350 mg and regional myocardial pharmacokinetics with coronary arterial doses ranging from 2.5 to 12.5 mg. These studies generated approximately 12 000 blood samples.     

盐酸布比卡因、透明质酸酶对大鼠在体肌卫星细胞增殖的影响

目的 :研究盐酸布比卡因和透明质酸酶对成年大鼠肌卫星细胞在体增殖的影响。方法 :免疫组化法 ,H .E染色法 ,光镜和电镜观察。结果 :①正常对照组和生理盐水组肌纤维完整 ,有少量Desmin阳性肌卫星细胞 ,面密度值为 0 .66%± 0 .57%和 2 .48%± 1.13 %。生理盐水组较正常对照组无显著差异 (P >0 .0 5)。②透明质酸酶组肌纤维完整 ,Desmin阳性肌卫星细胞数量增加 ,面密度值为 2 .52 %± 1.41% ,较生理盐水组和正常对照组无显著差异(P >0 .0 5)。③盐酸布比卡因组和盐酸布比卡因 +透明质酸酶混合液组均可见大量坏死和溶解的肌纤维 ,并伴有肌卫星细胞的激活、增殖 ,Desmin阳性肌卫星细胞显著增加 ,并有部分融合形成小肌管。面密度值分别为 19.0 1%± 4.74%和 2 2 .41%± 7.64% ,较生理盐水组显著增加 (P <0 .0 1)。结论 :局麻药盐酸布比卡因能引起在体肌卫星细胞的活化、增殖并形成肌管 ,单独透明质酸酶溶液在本实验条件下对在体肌卫星细胞无明显作用     

The efficacy of ropivacaine and bupivacaine in the caesarean section and the effect on the vital signs and the hemodynamics of the lying-in women

ObjectiveTo investigate the efficacy of ropivacaine and bupivacaine in caesarean section and vital signs and the hemodynamics of the lying-in women.MethodsA total of 480 lying-in women who were admitted to this hospital for treatment between December 2017 and June 2018 were enrolled into this study as the subjects, which were divided into the experiment group and the control group, with 240 subjects in each group. In the experiment group, subjects received the local anesthesia by infusion of 1.5 mL ropivacaine (0.75%), while those in the control group also took the local anesthesia by infusion of 1.5 mL bupivacaine (0.75%). Thereafter, we observed the differences in the anesthetic efficiency, vital signs and hemodynamics of the lying-in women between two groups.ResultsThe excellent and good rates of the anesthesia in two groups were 92.1% and 87.9%, showing no obvious difference; in the experiment group, the average arterial pressures and systolic pressures at 5 min and 10 min after combined spinal and epidural analgesia (CSEA) were all elevated when comparing to the control group (all P < 0.05); in the experiment group, the onset time was obviously extended, while duration of sensory and motor block and the duration of motor block were all shorter than those in the control group (all P < 0.05). During anesthesia, the incidence rate of the adverse reactions in the control group was 2.50%, significantly higher than 0.83% in the experiment group (P < 0.05).ConclusionDespite that ropivacaine and bupivacaine are efficient in anesthesia in the CSEA in the caesarean section, ropivacaine is more recommended for little influence on the hemodynamics, shorter duration of sensory block and motor block and low incidence rate of adverse reactions, which are conducive to the recovery and also safe to the patients.     

Bupivacaine, but not lidocaine, disrupts cardiolipin-containing small biomimetic unilamellar liposomes

Inadvertent intravenous administration of bupivacaine, unlike that of lidocaine, is associated with significant cardiotoxicity. However, the mechanism(s) underlying this phenomenon is uncertain. High concentrations of cardiolipin, an anionic phospholipid, are found in the mitochondria membrane of cardiomyocytes. We hypothesized that bupivacaine, but not lidocaine, interacts avidly with cardiolipin in the mitochondria membrane of cardiomyocytes and alters its integrity thereby accounting, in part, for cardiotoxicity. Accordingly, the purpose of this study was to begin to address this issue by determining the effects of bupivacaine and lidocaine on permeability of cardiolipin-containing biomimetic small unilamellar liposomes. We found that bupivacaine, but not lidocaine, elicited a significant, concentration-dependent increase in carboxyfluorescein release from cardiolipin-containing small unilamellar liposomes (size, 165 nm) composed of egg yolk phosphatidylcholine and cholesterol (p < 0.05). Both drugs had no significant effects on carboxyfluorescein release from liposomes devoid of cardiolipin (p > 0.5). Collectively, these data indicate that bupivacaine, but not lidocaine, interacts avidly and selectively with biomimetic small unilamellar liposomes containing cardiolipin and disrupts their integrity. We suggest that these interactions underlie, in part, bupivacaine-induced cardiotoxicity.