Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

OBJECTIVE:

It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage.

METHODS:

We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student''s t-test.

RESULTS:

The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group.

CONCLUSION:

For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion.     

Eritoran对蛛网膜下腔出血兔基底动脉IL-1β、TNF-α和IFN-β mRNA表达的影响

目的 探讨eritora对蛛网膜下腔出血(subarachnoid hemorrhage,SAH)兔基底动脉炎性细胞因子白细胞介素-1β(interleukin-1β,IL-1β)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和干扰素-β(interferon-β,IFN-β)mRNA表达的影响.方法 36只健康成年雄性新西兰兔随机分为SAH组(n=12)、生理盐水组(n=12)和eritoran组(n=12).采用枕大池自体动脉血二次注血法建立SAH模型,生理盐水组用生理盐水等量置换脑脊液,SAH组置换脑脊液后立即注入等量自体非肝素化动脉血,eritoran组在每次经枕大池注血后立即静脉注射eritoran( 1.5 mg/kg).进行摄食情况和神经功能缺损评分.实时荧光定量聚合酶链反应检测基底动脉IL-1β、TNF-α和IFN-β mRNA表达.结果 Eritoran组进食评分[(1.20 ±0.41)分对(2.20±0.61)分;t=53.073,P=0.002]、神经功能缺损评分[(1.46±0.32)分对(2.60±0.08)分;t=306.431,P=0.001]、IL-1β [(1.22±0.48)对(2.38±0.06);P=0.000]、TNF-α[(1.39±0.07)对(3.32±0.21),P=0.000]和IFN-β[(1.51±0.08)对(2.18±0.05),P=0.000] mRNA表达均显著低于SAH组.结论 Eritoran可下调SAH兔基底动脉炎性细胞因子IL-1β、TNF-α和IFN-β mRNA表达,增加摄食量,减轻神经功能缺损.     

光动力疗法治疗恶性肿瘤作用机制的研究进展

【摘要】 光动力疗法(PDT)是继手术、放化疗等传统治疗肿瘤手段外的一种新的抗肿瘤模式。PDT机制目前尚不完全清楚, 已知其利用肿瘤细胞高摄取光敏剂的特性, 使用相应波长的激光照射, 使光敏剂产生单线态氧或其他活性氧, 通过非细胞凋亡途径或直接高效诱导凋亡或导致肿瘤组织坏死杀死癌细胞。PDT也可损伤肿瘤组织的血管内皮细胞及介导自身免疫系统的激活。     

出血坏死表型肝细胞癌病理特征及预后的前瞻性初步研究

目的:探讨出血坏死表型的肝细胞癌(HN-HCC)的病理特征及临床预后。方法:前瞻性入组67例手术与病理证实的HN-HCC患者,并以同期37例非HN-HCC(NHN-HCC)患者为对照。比较HN-HCC与NHN-HCC大体病理学差异;对HN-HCC标本的组织病理学以及Ki-67、缺氧诱生因子1α(HIF-1α)、cleaved-caspase-3的表达行多区域检测;检测HN-HCC标本碳酸酐酶IX(CA-IX)和E-钙黏蛋白的表达;比较HN-HCC患者与NHN-HCC患者术后生存率的差异。结果:HN-HCC与NHN-HCC呈现明显不同的大体病理形态。组织病理学观察与免疫组化检测显示,在HN-HCC瘤内不同区域,细胞分化程度有明显差异;Ki-67、cleaved-caspase-3、HIF-1α的表达量有明显差异(均P0.05)。在HN-HCC标本中,CA-IX阳性表达率为86.5%(58/67),E-钙黏蛋白为25.3%(17/67),且两者表达呈负相关(r=-2.601,P0.05)。与NHN-HCC患者比较,HN-HCC患者的1、3、5年总体生存率(71.9%、10.7%、2.8%vs.87.5%、35.6%、3.6%)与无瘤生存率(67.0%、15.4%、3.2%vs.81.2%、34.3%、4.0%)均明显降低(均P0.05)。结论:HCC合并出血坏死病理改变提示肿瘤有较强的瘤内异质性和侵袭转移潜能,患者预后不良。     

Influence of extremely low frequency magnetic fields on Ca2+ signaling and NMDA receptor functions in rat hippocampus

The nervous tissue of many vertebrates, including humans, can synthesize beta-alanyl-L-histidine (carnosine). The biological functions of carnosine are still open to question, although several theories supported by strong experimental data have been proposed. The objective of this study was to examine the effects of carnosine on neurotoxicity in differentiated rat pheochromocytoma (PC12) cells. Neurotoxicity was induced by N-methyl-D-aspartate (NMDA), which caused time- and concentration-dependent cell death as measured by MTT and LDH assays. Pretreatment with carnosine significantly prevented the neurotoxicity in a concentration-dependent manner. The protective effect of carnosine was antagonized by the H1 receptor antagonist pyrilamine, but not by the H2 receptor antagonist cimetidine. In addition, alpha-fluoromethylhistidine, a histidine decarboxylase inhibitor, slightly reversed the protective action of carnosine. These results indicate that carnosine can effectively protect against NMDA-induced necrosis in PC12 cells, and its protection may in part be due to the activation of the postsynaptic histamine H1 receptor. The study suggests that carnosine may be an endogenous protective factor and calls for its further study as a new anti-excitotoxic agent.     

不同缺血程度的绞窄性肠梗阻超声表现：与手术病理对照

目的探讨不同缺血程度绞窄性肠梗阻的超声表现及临床意义。方法回顾性分析52例不同缺血程度绞窄性肠梗阻患者的声像图特征,并与手术、病理结果相对照。结果肠管缺血、但尚无坏死时,声像图特征包括肠壁增厚,呈低回声,横断面呈"面包圈征",黏膜皱襞水肿增厚,呈"珊瑚样"改变;8例肠壁间可见多个环状低回声,可呈"串珠样",血流信号为静脉血流频谱;13例腹腔积液,透声好。肠管缺血坏死时,声像图可见黏膜层与浆膜层呈"分离征"或"剥脱样"改变,局部管壁缺乏膨胀性,呈塌瘪征象;CDFI示局部肠壁间血流信号消失;12例腹腔积液,呈密集点状高回声群,动态观察短期内积液快速增多。结论超声可评价绞窄性肠梗阻所致不同程度肠管缺血,对临床诊断及治疗具有重要价值。     

Comparison of toxicity effects of ropivacaine,bupivacaine, and lidocaine on rabbit intervertebral disc cells in vitro

Background contextIt has been shown that bupivacaine, the most commonly used local anesthetic to relieve or control pain in interventional spine procedures, is cytotoxic to intervertebral disc (IVD) cells in vitro. However, some other common local anesthetics, such as ropivacaine and lidocaine, are also frequently used in the treatment of spine-related pain, and the potential effects of these agents remain unclear.PurposeThe purpose of this study was to evaluate the effect of various local anesthetics on rabbit IVD cells in vitro and further compare the cytotoxicity of ropivacaine, bupivacaine, lidocaine, and saline solution control.Study designControlled laboratory study.SubjectsRabbit annulus fibrosus (AF) and nucleus pulposus (NP) cells were isolated from Japanese white rabbits.MethodsBoth AF and NP cells at the second generation maintained in monolayer were exposed to various concentrations of local anesthetics (eg, bupivacaine) or different durations of exposure and evaluated for cell viability by use of cell counting kit-8 (CCK-8). In addition, to compare the cytotoxicity of ropivacaine, bupivacaine, lidocaine, and saline solution control in commercial concentration, the viability was analyzed by flow cytometry after 60-minute exposure, and the morphologic changes were observed by the phase-contrast microscopy. Apoptosis and necrosis of IVD cells were confirmed by using fluorescence microscopy with double staining of Hoechst 33342 and propidium iodide.ResultsRabbit IVD cell death demonstrated a time and dose dependence in response to bupivacaine and lidocaine. However, ropivacaine only exerted a significant time-dependent effect on IVD cells. There was no significant difference in IVD viability after treatment with different doses of ropivacaine. In addition, the results showed that lidocaine was the most toxic of the three local anesthetics and that ropivacaine presented less cytotoxicity than lidocaine and bupivacaine. Fluorescence microscopy also confirmed that the short-term toxic effect of local anesthetics on both AF and NP cells was mainly caused by necrosis rather than apoptosis.ConclusionsResults show that bupivacaine and lidocaine decrease cell viability in rabbit IVD cells in a dose- and time-dependent manner. All local anesthetics should be avoided if at all possible. Ropivacaine may be a choice if necessary, but it is also toxic. The increase in cell death is more related with cell necrosis rather than cell apoptosis. If these results can be corroborated in tissue explant models or animal studies, caution regarding diagnosing, treating, and controlling spine-related pain with local anesthetics is prompted.     

Platelet activation and myocardial necrosis in patients undergoing radiofrequency and cryoablation of isthmus-dependent atrial flutter.

AIMS: Lower platelet activation by cryoenergy compared with radiofrequency (RF) energy was recently demonstrated immediately following ablation procedures of cardiac arrhythmias. Due to the delayed occurrence of cryolesions it is currently unknown, if cryoenergy and RF energy are associated with similar platelet activation and myocardial necrosis in the days after the procedure. METHODS AND RESULTS: We enrolled 38 patients with common atrial flutter undergoing cavotricuspid isthmus ablation with either RF energy (n = 23) or cryoenergy (n = 13). Ten patients undergoing RF ablation and receiving aspirin served as antiplatelet control group. Troponin T and platelet surface protein expression of P-selectin were determined before and immediately after ablation as well as on day 1 and 2 thereafter. Rise in troponin T was amplified after RF ablation (0.50 +/- 0.37 microg/L) when compared with cryoablation (0.24 +/- 0.20 microg/L; P = 0.024). In patients without aspirin, a significant increase in P-selectin expression was observed on day 1 after intervention in RF ablation compared with cryoablation (80 +/- 26 vs. 63 +/- 16 arbitrary units; P = 0.048). Platelet activation was attenuated in patients receiving aspirin. CONCLUSION: Successful ablation of atrial flutter with cryoenergy is associated with less myocardial necrosis and platelet activation compared with ablation with RF energy. Increased platelet activation following RF ablation can be attenuated by concomitant treatment with aspirin.     

Loss of plasma membrane integrity,complement response and formation of reactive oxygen species during early myocardial ischemia/reperfusion

Loss of plasma membrane integrity (LPMI) is a hallmark of necrotic cell death. The involvement of complement and ROS in the development of LPMI during the early stages of murine myocardial ischemia–reperfusion injury was investigated. LPMI developed within 1 h of reperfusion to a level that was sustained through 24 h. C3 deposition became significant at 3-h reperfusion and thus contributed little to LPMI prior to this time. SOD1 transgenic mice had significantly less LPMI compared with WT mice at 1 h of reperfusion but not at later time points. Catalase transgenic mice were not protected from LPMI at 1-h reperfusion compared with WT mice, but had 69% less LPMI at 3-h reperfusion. This protection was transient. At 24-h reperfusion the LPMI of catalase transgenic mice was identical to that of WT mice. The delayed benefits of over-expressed catalase compared with SOD1 are consistent with its antioxidant action downstream of SOD1. The onset of LPMI occurs within 1 h of reperfusion at a level that is maintained through 24 h. ROS contribute significantly to LPMI during the first 3 h of reperfusion, while complement deposition, which becomes significant after 3-h reperfusion, may contribute thereafter.