Glucose Content and Efficiency of Glycolysis in Protected Ischemic Kidneys of Different Species

In ischemic canine kidneys protected by Bretschneider's HTK solution the glycolytic lactate production is limited by a low renal substrate content. However, for anaerobic energy supply ischemic organs depend on glycolysis. To evaluate the role of glycolysis in renal protection, the relationship between lactate production and anaerobic energy supply was examined in protected kidneys of dogs, sheep, and swine. Additionally, in canine kidneys an attempt was made to improve anaerobic energy provision by adding glucose to the protective solution. The results were as follows: (1) According to increasing lactate production from swine to dog to sheep, intraischemic ATP decay was delayed least in swine and most in sheep. (2) Glucose addition (10 mM) to the HTK solution roughly doubled the time for ATP to fall to 1 μmollg dry wt (t_Atp) in dogs. (3) The greater the lactate production in all three species, the lower the decrease in SAN (ATP + ADP + AMP) from 5 to 120 min of ischemia. (4) A glucose additive in the protective solution led to a significant (p >. 005) increase of SAN in dogs at 120 min of ischemia. A sufficient substrate supply seems to be an essential component of a reliable renal protection.     

Cell effects of xenon <Emphasis Type="Italic">n vitro</Emphasis> under hypothermal conditions

The effects of Xe on cell viability and redox balance in the culture of Wistar rat thymocytes were studied in vitro during 24-h storage under hypothermic conditions. The results indicate that after bubbling of cell suspensions (5×10⁶ cell/ml, 4 ml medium), the weight of Xe in flasks was 15–43 mg, whereas in cell-free medium no weight increment due to gas accumulation in the system was detected. The content of Xe in cell suspension slightly decreased over 24-h culturing at ambient temperature (by 10% of initial level). Xenon significantly improved cell survival during thermal exposure of all modes. The maximum cytoprotective effect of Xe was observed under rigorous thermal conditions associated with significant cell death without chemical protectors (3°C, −35°C). The effect of Xe was less pronounced at mild temperatures (23–37°C) or in the presence of chemical protectors (−35°C with dimethylsulfoxide). The mechanisms of the effect of the inert gas are determined by its antioxidant or prooxidant action. The capacity of Xe to improve cell survival under hypothermic conditions can be used for the development of new methods for transportation and storage of cell material. __________ Translated from Kletochnye Tehnologii v Biologii i Medicine, No. 2, pp. 74–77, April, 2007     

人参皂苷CK对人肝癌细胞HepG2迁移及侵袭的影响

目的探讨人参皂苷CK对人肝癌细胞增殖、迁移、侵袭的影响及其可能机制。方法取对数生长期的Hep G2细胞,用不同浓度人参皂苷CK(0、10、20、40、80μmol·L^-1)处理,MTT法检测人参皂苷CK对细胞增殖的影响;细胞划痕实验、Transwell实验检测人参皂苷CK对肝癌细胞迁移、侵袭的影响;Western blot检测人参皂苷CK对Hep G2细胞中E-cadherin、N-cadherin及信号分子p-ERK、ERK、p-Akt、Akt水平的影响。结果 MTT检测结果显示,人参皂苷CK对肝癌Hep G2细胞生长有抑制作用;划痕和Transwell实验结果显示,人参皂苷CK可抑制Hep G2细胞的迁移和侵袭;Western blot结果显示人参皂苷CK可降低N-cadherin表达,明显升高E-cadherin表达水平,同时抑制ERK和Akt信号的磷酸化。结论人参皂苷CK可抑制肝癌细胞的迁移和侵袭过程,可能与抑制ERK和Akt信号有关。     

Alpinumisoflavone rescues glucocorticoid-induced apoptosis of osteocytes via suppressing Nox2-dependent ROS generation

Background

Long term use of glucocorticoids is one of the most common causes of secondary osteoporosis. Osteocyte, the most abundant cell type in bone, coordinates the function of osteoblast and osteoclast. This study evaluates the protective effect of alpinumisoflavone (AIF), a naturally occurring flavonoid compound, on dexamethasone (Dex)-induced apoptosis of osteocytes.

多巴酚丁胺负荷试验结合脉冲组织多普勒二尖瓣环运动定量评估心肌梗死患者心肌存活

目的研究脉冲多普勒组织成像技术(DTI-PW)中二尖瓣环速度检测存活心肌的可行性及价值.方法 40例陈旧性心肌梗死患者室壁按照硝酸甘油(NTG)介入99Tcm-MIBI SPECT 结果分为有存活心肌组、无存活心肌组,采用小剂量多巴酚丁胺负荷超声心动图试验,测量相应梗死壁二尖瓣环多巴酚丁胺(Dobutamine,Dob)负荷前及每级Dob负荷试验时的收缩期峰值速度Vs、射血前期PEP、射血期ET;另选20例年龄匹配的正常人为对照组,测量6个室壁二尖瓣环Vs、PEP、ET.结果 Dob 5μg/(kg·min)时,以Vs增加量≥2 cm/s为临界值,则检测存活心肌的敏感度为75%,特异度为76%,准确度为75%,以PEP/ET变化率2(Dob 5μg/(kg·min)时PEP/ET与Dob负荷前PEP/ET的比值)≥100%作为诊断无存活心肌的临界值,则敏感度为73%,特异度为85%,准确度为79%;以Dob 10 μg/(kg·min)时Vs增加量≥3 cm/s为临界值,则检测存活心肌的敏感度增加到83%,特异度为79%,准确度增加到81%,以PEP/ET变化率3(Dob 10μg/(kg·min)时PEP/ET与Dob负荷前PEP/ET的比值)≥100%作为诊断非存活心肌的临界值,则敏感度为82%,特异度为85%,准确度为84%.结论 Dob负荷时二尖瓣环Vs、PEP/ET可用于检测存活心肌,方法简单、可靠.     

急性心肌梗死后心肌存活性的相关影响因素分析

目的探讨急性心肌梗死后影响患者心肌存活性的临床相关因素。方法采用回顾性对比研究的方法,104例急性心肌梗死患者以99Tcm-MIBI SPECT静息显像及18F-FDG SPECT心肌代谢显像的检查结果分为梗死区心肌有存活组和无存活组,对比两组患者病史及各项临床特点并进行统计学分析。结果与梗死区无存活心肌组相比,梗死区仍有心肌存活组患者ECG表现ST段抬高的导联数较少(4.30±1.63vs5.22±1.97,P=0.025),ST段抬高总数值较低(0.93±0.64vs1.42±1.17,P=0.028),经皮冠状动脉介入治疗(PCI)开通梗死相关冠脉(IRA)距症状开始时间在6小时以内的患者比例较大(68.9%vs41.2%,P=0.021),PCI前冠脉血流TIMI0或1级的人数比例较低(57.7%vs88.2%,P=0.003),侧支循环0级患者比例较少(44.4%vs70.6%,P=0.024),两组差别具有统计学意义。结论心电图ST段抬高导联数及ST段抬高总数值、症状距IRA开通时间、PCI前冠脉血流TIMI分级及侧支循环分级是与急性心肌梗死后心肌存活相关的临床因素。     

In situ label‐free cell viability assessment of nucleus pulposus tissue

Regenerative medicine approaches aiming at treating degenerating intervertebral discs, a major cause of back pain, are increasingly tested in ex‐vivo disc explant models mimicking in‐vivo conditions. For assessing the efficacy of regenerative therapies, cell viability is commonly measured requiring specific labels to stain cells. Here, we demonstrate and evaluate how cellular auto‐fluorescence can be utilized to non‐invasively assess viability in disc tissue in‐situ using label‐free two‐photon microscopy. Live and dead bovine disc cells (0% and 100% cell viability) from the nucleus pulposus were seeded into collagen gels and auto‐fluorescence was characterized. Subsequently, nucleus pulposus explants were cultured for 6 days in media with different glucose supplementation (0, 0.25, 0.5, and 1 g/L) to induce different degrees of cell death. Then, samples were split and viability was assessed using label‐free two‐photon microscopy and conventional staining. Results show that live and dead nucleus pulposus cells systematically emit auto‐fluorescent light with distinct characteristics. Cell viability values obtained with label‐free microscopy did not significantly differ from those acquired with staining. In summary, monitoring auto‐fluorescence facilitates accurate cell viability assessment in nucleus tissue requiring no additional dyes. Thus, this technique may be suitable for pre‐clinical testing of regenerative therapies in nucleus pulposus cultures. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:545–550, 2014.