白血病病人与健康人白细胞氧自由基及耗氧量的比较

利用电子自旋共振（ESR）自旋捕集与探针技术,观察白血病病人与健康人白细胞氧代谢过程释放活性氧自由基的种类及其耗氧量的变化。结果发现,白血病病人白细胞经豆蔻酰佛波醇乙酯（PMA）刺激只捕集到微弱的羟自由基（OH）信号,刺激前后耗氧量差别不显;健康人白细胞可得到超氧阴离子自由基（O^-2）的ESR波谱信号,耗氧量较正常呼吸即未受PMA刺激时大大增加（P＜0.001)。两组白细胞耗氧量比较,未受刺激时两无明显差别;刺激后,健康组明显高于白血病组（P＜0.001)。结论说明白血病病人白细胞缺乏呼吸爆发功能,因此耗氧量明显低于健康人白细胞。     

Temperature-dependent free radical reaction in water

Temperature-dependent free radical reactions were investigated using nitroxyl radicals as redox probes. Reactions of two types of nitroxyl radicals, TEMPOL (4-hydroxyl-2,2,6,6-tetramethylpiperidine-N-oxyl) and carbamoyl-PROXYL (3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl), were tested in this paper. Heating a solution containing a nitroxyl radical and a reduced form of glutathione (GSH) caused temperature-dependent decay of electron paramagnetic resonance (EPR) signal of the nitroxyl radical. Heating a solution of the corresponding hydroxylamine form of the nitroxyl radical showed EPR signal recovery. The GSH-dependent reduction of nitroxyl radicals at 70°C was suppressed by antioxidants, spin trapping agents, and/or bubbling N₂ gas, although heating carbamoyl-PROXYL with GSH showed temporarily enhanced signal decay by bubbling N₂ gas. Since SOD could restrict the GSH-dependent EPR signal decay of TEMPOL, O₂^•− is related with this reaction. O₂^•− was probably generated from dissolved oxygen in the reaction mixture. Oxidation of the hydroxylamines at 70°C was also suppressed by bubbling N₂ gas. Heating a solution of spin trapping agent, DMPO (5,5-dimethyl-1-pyrroline-N-oxide) showed a temperature-dependent increase of the EPR signal of the hydroxyl radical adduct of DMPO. Synthesis of hydroxyl radical adduct of DMPO at 70°C was suppressed by antioxidants and/or bubbling N₂ gas. The results suggested that heating an aqueous solution containing oxygen can generate O₂^•−.     

Role of plasma protein and low-molecular weight substances in the change of hydroxyl radical scavenging activity in hemodialysis patients

While it is well known that hemodialysis (HD) patients with end stage renal failure are exposed to high oxidative stress, there is not a general opinion regarding whether antioxidant activity is high or low in these patients. We evaluated the variation of plasma hydroxyl radical scavenging activity (p-HRSA) by a single-session of HD in 69 patients by using a new system, reactive flow-injection electron spin resonance. And then comparing p-HRSA with their biochemical parameters, we tried to elucidate what components affected p-HRSA in the HD patients. The average of p-HRSA significantly increased after HD and the variation of p-HRSA by HD was correlated with that of plasma total protein (TP). In 5 patients however, their p-HRSA decreased after HD, in spite of increasing TP. In pre-HD, the p-HRSA values and hydroxyl radical scavenging activity of low-molecular weight fraction of plasma were significantly higher in these 5 patients than in patients whose p-HRSA increased after HD. These 5 patients were in an inflammatory state. These findings suggest that p-HRSA is mainly affected by TP, but caution should be exercised in patients who have high p-HRSA before HD and whose p-HRSA does not increase after HD.     

家兔休克再灌注胃粘膜氧自由基的直接测定与其意义

采用自旋捕捉剂（ＰＢＮ）以稳定高度活性的自由基，并用电子自旋共振（ＥｌｅｃｔｒｏｎＳｐｉｎＲｅｓｏ－ｎａｎｃｅ，ＥＳＲ）技术直接测定休克再灌注胃粘膜不同时限氧自由基（ＯｘｙｇｅｎＦｒｅｅＲｅｄｉｃａｌｓ，ＯＦＲ）的含量变化，并用肉眼和光镜观察胃粘膜形态变化。实验家兔２６只随机分为４组。结果显示：休克９０ｍｉｎ组的胃粘膜ＯＦＲ含量已显著升高，假休克组相比具有统计学意义（Ｐ＜０．０５），再灌注后胃粘膜ＯＦＲ含量进一步增高，并随时间延长而进一步递升，与假休克组相比均具有非常显著意义（Ｐ＜０．０１）。病理改变严重程度与ＯＦＲ含量变化趋势基本一致。     

Bactericidal effect of hydroxyl radicals generated from a low concentration hydrogen peroxide with ultrasound in endodontic treatment

One approach to enhance the disinfection of root canals in endodontic treatment is ultrasonic irrigation with sodium hypochlorite. Reactive oxygen species, such as hydroxyl radical, are generated by biological defense systems to kill invading bacteria. Ultrasonic irrigation with hydrogen peroxide may be a promising option to increase hydroxyl radical generation. We examined the bactericidal effects of hydroxyl radical generated from low concentration hydrogen peroxide with ultrasound in vitro. An ultrasonic tip was submerged in 0.5 or 1.0 M hydrogen peroxide in a microfuge tube. hydrogen peroxide was irradiated with the ultrasound, the tip of which was maintained centered in the tube to mimic ultrasonic irrigation. Hydroxyl radical generation was assessed by electron spin resonance spectroscopy. Subsequently, Enterococcus faecalis suspension in hydrogen peroxide was prepared and irradiated as described above. Bactericidal effects were assessed by viable counting. Electron spin resonance measurements showed that hydroxyl radical generation increased significantly in a time- and dose-dependent manner (two-way analysis of variance and Tukey’s test, p<0.05). Moreover, the bactericidal effects of hydrogen peroxide against Enterococcus faecalis were enhanced by ultrasonic irradiation in a time- and dose-dependent manner. These results suggest that ultrasonic irrigation in the presence of low concentration hydrogen peroxide can serve as a disinfection strategy in endodontic treatment.     

Method for assessing X-ray-induced hydroxyl radical-scavenging activity of biological compounds/materials

A method for correctly assessing hydroxyl radical scavenging activity of antioxidative chemicals and/or biological compounds/materials was proposed. This method can simultaneously assess two factors, i.e. hydroxyl radical-scavenging and 5,5-dimethyl-2-hydroxy-1-pyrrolidine-N-oxide (hydroxyl radical adduct of 5,5-dimethyl-1-pyrroline-N-oxide)-reducing ability, as antioxidative properties. In this paper, some biologically common hydrophilic molecules, cell culture media, and rat plasma were tested. X-ray-induced hydroxyl radical can be detected using the electron paramagnetic resonance spin trapping technique. Using X-ray irradiation of the reaction mixture as the hydroxyl radical source, the true hydroxyl radical-scavenging ability of the subjected antioxidant can be assessed. In addition, the method simultaneously measures the reduction of 5,5-dimethyl-2-hydroxy-1-pyrrolidine-N-oxide, to estimate the reducing ability of the antioxidant. Biological materials, such as sugars and proteins, could abolish hydroxyl radical at the biological concentration. Ascorbic acid showed reducing ability at the biological concentration. The simultaneous assessment of hydroxyl radical-scavenging and reducing ability of antioxidants can be an informative index for antioxidants.     

Antioxidant effects of antioxidant biofactor on reactive oxygen species in human gingival fibroblasts

The purpose of this study was to investigate the effects of antioxidant biofactor (AOB) on reactive oxygen species (ROS). Generation of superoxide radical (O₂^•−) and hydroxyl radical (^•OH) was determined using an electron spin resonance (ESR) spin-trapping method. AOB was added at different concentrations to these free radical generating systems. The generation of both O₂^•− and ^•OH was scavenged by the addition of AOB in a dose-dependent manner. These results indicate that AOB has strong antioxidant properties against these radicals. We further investigated the anti-oxidative effect of AOB on human gingival fibroblasts (HGFs). HGFs were treated for 3 h with α-MEM containing a combination of AOB and H₂O₂ (AOB + H₂O₂ group), containing H₂O₂ (H₂O₂ group), or containing AOB alone (AOB group). Non-stimulated HGFs were used as a control group. The number of surviving cells was in the order of the AOB group > control group > AOB + H₂O₂ group > H₂O₂ group. The level of expression of type I collagen mRNA and production of collagen were also in the order of the AOB group > control group > AOB + H₂O₂ group > H₂O₂ group. In conclusion, our results suggest that AOB may protect HGFs against oxidative stress by reducing stress-induced ROS.     

Radical scavenging activity of bisbenzylisoquinoline alkaloids and traditional prophylactics against chemotherapy-induced oral mucositis

Background and objective: Oral mucositis is a major severe toxic side‐effect of systemic chemotherapy and irradiation in patients with cancer. Various free radical scavengers have been shown to prevent chemotherapy‐induced skin necrosis. The objective of this study was to determine the antioxidant activity of a bisbenzylisoquinoline alkaloidal compound (BIQAC) and a series of chemicals, including allopurinol, used clinically for the treatment of chemotherapy‐induced mucositis. Methods: Allopurinol, melatonin, camostat mesilate, gabexate mesilate, hydroquinone and BIQAC were tested for their radical scavenging activities on four different radical species: 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) cation radical (ABTS^•+) using standard methods, and superoxide anion radical (O₂⁻) and hydroxyl radical (OH^•) using electron spin resonance. Results: Allopurinol had radical scavenging activity against O₂⁻ only. Melatonin had strong radical scavenging activity against ABTS^•+, and weak activity against DPPH radical and OH^•. Camostat mesilate had weak radical scavenging activity against OH^•. Gabexate mesilate had no radical scavenging activity against any of these radicals. Hydroquinone had strong radical scavenging activity against DPPH radical and ABTS^•+, and moderate activity against both O₂⁻ and OH^•. BIQAC had moderate radical scavenging activity against DPPH radical, strong radical scavenging activity against ABTS^•+ and O₂⁻, and weak activity against OH^•. Conclusion: The BIQAC had the most braod‐spectrum radical scavenging activity, suggesting that it may be effective against chemotherapy‐induced mucositis. These findings also suggest that this radical‐scavenging activity screening method, against four kinds of radicals, may be useful for the screening of radical scavenging activity of new natural and synthetic chemicals.     

蒸馏水用于肺癌根治术胸腔浸泡冲洗的不良影响

目的探讨蒸馏水在肺癌根治术中胸腔浸泡冲洗时对患者心率（HR）、血压（BP）及心电图（ECG）的影响。方法将400例肺癌根治术患者分为A、B两组,于手术关胸前分别用43C蒸馏水和43℃生理盐水倒入胸腔浸泡10min,然后吸出;观察并记录浸泡前、浸泡中5min、浸泡中10min及浸泡后5min患者ECG、HR、收缩压（SBP）、舒张压（DBP）的变化情况,并进行前后对比。结果A组患者浸泡前后的HR、SBP、DBP差异有显著意义（P〈0.01）。对肺叶连同部分心包及受浸润的血管基底部或部分心房壁一并切除的患者,浸泡5min内有57.14％出现了心律失常,与浸泡前相比,差异有极显著意义（P〈0.01）。而B组浸泡前后变化较小。结论使用蒸馏水行胸腔浸泡冲洗时,要严密观察患者的HR、BP及ECG变化;对于肺叶连同部分心包及受浸润的血管基底部或部分心房壁一并切除的患者,术中应尽量采用生理盐水浸泡冲洗。     

Direct demonstration of nitric oxide formation in organs of rabbits treated by transdermal glyceryl trinitrate using an in vivo spin trapping technique

Glyceryl trinitrate (GTN) is commonly delivered by a patch for the treatment of angina pectoris. The idea is now generally accepted that GTN requires a biotransformation process that activates the drug, in particular through nitric oxide (NO) generation. However, the pharmacokinetics of NO delivery from GTN still remains obscure. The objective of this study was to assess GTN-derived NO formation in vascular tissues and organs in rabbit given GTN patches. NO levels were evaluated in rabbits after 3 h of treatment with a 10 mg GTN patch (GTN group; n = 7) or a placebo patch (CTL; n = 7). Nitrosylhaemoglobin (HbNO) was evaluated by electron spin resonance (ESR) spectroscopy in red cell suspension. In vivo spin trapping technique using FeMGD as a spin trap, associated with ESR was used to quantify NO in tissues. The NO-spin trap complex, which is a relatively stable product, has been measured in several tissues. The ESR spectrum corresponding to HbNO was not found in red cell of GTN or CTL rabbits. The spectrum corresponding to the NO-spin trap complex was observed in all analysed tissues of CTL rabbits. The signal was significantly increased in liver, renal medulla, heart left ventricle and spleen of GTN-treated rabbits, and to a lesser extent in right ventricle and lung. No difference was shown between NO-spin trap levels measured in aorta or inferior vena cava from GTN or CTL rabbits. These data suggest that GTN patch treatment induced NO release, and that tissue-specific differences in transdermal GTN-derived NO exist. The GTN-NO pathway appears to be largely involved in organs such as the liver, kidney and heart.     

Studies by electron paramagnetic resonance of the importance of iron in the hydroxyl scavenging properties of ascorbic acid in plasma: Effects of iron chelators

Summary— Ascorbic acid is considered to be the most important antioxidant of plasma. Its oxidation leads to the ascorbyl free radical (AFR), detected by electron paramagnetic resonance (EPR) spectroscopy. The purpose of this study was to investigate by EPR the interaction of plasma AFR levels in different situations of oxidative stress. Our results showed that plasma AFR remains constant after rat feeding with vitamin C (5 mg or 50 mg per 100 g body weight). We also demonstrated that: (1) the ascorbyl free radical (AFR) level was increased after direct addition of iron Fe³⁺/EDTA to plasma, the optimal level was reached after addition of 8 μM Fe³⁺/EDTA (1:2); (2) this AFR production was associated with the formation of hydroxyl radicals. Iron chelators (deferrioxamine, a synthetic iron chelator and apotransferrine, a biological iron chelator) added just before the Fe³⁺/EDTA complex inhibited the increase of AFR signal induced by this complex. The scavenging effect of plasma was significantly correlated with the AFR production. Therefore, AFR, which is naturally present in plasma, could be used as an index of oxidative stress in which free radicals or adverse iron mobilisation are implicated.     

The effect of irradiation wavelengths and the crystal structures of titanium dioxide on the formation of singlet oxygen for bacterial killing

Safe and effective methods for oral bacterial disinfection have been desired, since bacteria cause many infectious diseases such as dental caries, periodontal disease, and endodontic infections. Singlet oxygen (¹O₂) is attractive, because it is toxic to prokaryotic cells, but not to eukaryotic cells. We selected irradiation of titanium dioxide (TiO₂) as a source of ¹O₂, because it has been used in sunscreens and cosmetic products without complications. In order to establish the optimal oral photodynamic therapy conditions, we measured the rate of ¹O₂ formation from the irradiated anatase or rutile forms of TiO₂ using 365 or 405 nm lamps. The rate of ¹O₂ formation decreased in the following order: anatase, 365 nm > rutile, 405 nm > rutile, 365 nm > anatase, 405 nm. Therefore, we concluded that irradiation of the rutile form of TiO₂ by a 405 nm lamp is the most favorable photodynamic therapy condition, because visible light is more desirable than UV light from the viewpoint of patient safety. We also confirmed that there was no direct HO^• formation from the irradiated TiO₂.     

生脉溶液对超氧阴离子自由基作用的实验研究

目的体外测定并评价生脉溶液对超氧阴离子自由基（O2）的影响及作用。方法建立能够产生超氧阴离子的二甲基亚砜（DMSO）碱性体系，配制不同浓度生脉溶液、VC溶液为实验组及对照组，采用电子顺磁共振（EPR）方法，测定加入不同浓度溶液后体系中超氧阴离子信号的强度。结果加入浓度为20％、40％生脉溶液时，体系中超氧阴离子信号增强，且浓度为20％时与相同浓度对照组比较，增强显著（P〈0．01）；加入生脉溶液浓度增高至60％、80％及100％时，超氧阴离子信号强度逐渐减少并接近零，与相同浓度VC溶液对照组比较，减少显著（P〈0．01）。结论体外实验表明，较低浓度的生脉溶液对体系中超氧阴离子产生且有增强作用，而浓度较高时对其具有直接清除作用；体外实验说明生脉溶液对超氧阴离子自由基具有双向调节作用。     

远端胃癌根治术后不置胃管及早饮水的可行性和安全性研究

目的：探讨远端胃癌根治术后不置胃管及早饮水的安全性和可行性。方法将100例行远端胃癌根治术的患者根据手术先后顺序随机分为对照组和观察组各50例。对照组采用外科术后护理常规,予以安置胃管,禁食、禁饮,保留胃管至肛门排气、排便后再进食水;观察组除外科护理常规外,不安置胃管,术后6h患者麻醉完全清醒后,在医生指导下协助患者每4h饮一次温开水,每次10～20ml,对两组患者术后肠功能恢复时间、下床活动时间、腹胀、呼吸道感染、吻合口瘘等因素进行分析。结果观察组术后肠功能恢复时间短、下床时间早,差异具有显著意义（P＜0．05）;观察组术后咽喉疼痛、肺部感染发生率低,两组差异具有显著意义（P＜0．05）;两组术后恶心呕吐、吻合口瘘、腹胀发生的差异无显著意义（P＞0．05）。结论远端胃癌根治术后不置胃管及早饮水是安全可行的,可促进肠功能的恢复及减少术后并发症,提高患者舒适度,有利于病人术后的恢复。     

Crocetin reduces the oxidative stress induced reactive oxygen species in the stroke-prone spontaneously hypertensive rats (SHRSPs) brain

Crocetin is a natural carotenoid compound of gardenia fruits and saffron, which has various effects in biological systems. In this study, we investigated the antioxidant effects of crocetin on reactive oxygen species such as hydroxyl radical using in vitro X-band electron spin resonance and spin trapping. Crocetin significantly inhibited hydroxyl radical generation compared with the control. Moreover, we performed electron spin resonance computed tomography ex vivo with the L-band electron spin resonance imaging system and determined the electron spin resonance signal decay rate in the isolated brain of stroke-prone spontaneously hypertensive rats, a high-oxidative stress model. Crocetin significantly reduced oxidative stress in the isolated brain by acting as a scavenger of reactive oxygen species, especially hydroxyl radical, as demonstrated by in vitro and ex vivo electron spin resonance analysis. The distribution of crocetin was also determined in the plasma and the brain of stroke-prone spontaneously hypertensive rats using high-performance liquid chromatography. After oral administration, crocetin was detected at high levels in the plasma and the brain. Our results suggest that crocetin may participate in the prevention of reactive oxygen species-induced disease due to a reduction of oxidative stress induced by reactive oxygen species in the brain.     

Oxygen radical absorbance capacity (ORAC) of cyclodextrin-solubilized flavonoids, resveratrol and astaxanthin as measured with the ORAC-EPR method

Recently, we proposed an oxygen radical absorbance capacity method that directly quantifies the antioxidant's scavenging capacity against free radicals and evaluated the radical scavenging abilities for water soluble antioxidant compounds. In this study, we determined the radical scavenging abilities of lipophilic antioxidants which were solubilized by cyclodextrin in water. Commonly employed fluorescence-based method measures the antioxidant's protection capability for the fluorescent probe, while we directly quantify free-radical level using electron paramagnetic resonance spin trapping technique. In addition, the spin trapping-based method adopted controlled UV-photolysis of azo-initiator for free radical generation, but in fluorescence-based method, thermal decomposition of azo-initiator was utilized. We determined the radical scavenging abilities of seven well-known lipophilic antioxidants (five flavonoids, resveratrol and astaxanthin), using methylated β-cyclodextrin as a solubilizer. The results indicated that the agreement between spin trapping-based and fluorescence-based values was only fair partly because of a large variation in the previous fluorescence-based data. Typical radical scavenging abilities in trolox equivalent unit are: catechin 0.96; epicatechin 0.94; epigallocatechin gallate 1.3; kaempferol 0.37; myricetin 3.2; resveratrol 0.64; and astaxanthin 0.28, indicating that myricetin possesses the highest antioxidant capacity among the compounds tested. We sorted out the possible causes of the deviation between the two methods.     

动脉自旋标记技术定量分析阿尔茨海默病不同阶段脑血流量

目的基于三维动脉自旋标记(3D-ASL)技术定量分析阿尔兹海默病(AD)不同进展阶段脑血流量(CBF)改变,评价其鉴别效能。方法针对22例AD(AD组)、22例轻度认知功能障碍(MCI组)、25例主观认知功能下降(SCD组)患者和25名正常志愿者(NC组)采集头部3D T1WI和3D-ASL图像,经后处理获得双侧苍白球(GP)、壳核(PU)、尾状核(CA)、海马(HP)、丘脑(TH)、额叶皮层(FC)、顶叶皮层(PC)和枕叶皮质(OC)的CBF值。比较各组间CBF值差异,观察其与年龄、简易精神状态量表(MMSE)和蒙特利尔认知评估量表(MoCA)评分的相关性;以ROC曲线评价各脑区CBF值鉴别AD不同阶段的效能。结果AD组及MCI组除OC外各脑区CBF值均较NC组减低(P均<0.01);SCD组CA、PU及TH的CBF值均较NC组增高(P均<0.05)。AD组及MCI组HP的CBF值与MoCA评分均呈正相关(r=0.584、0.595,P均<0.01)。HP、TH、FC、PC、OC的CBF值鉴别AD不同进展阶段的AUC均较高。结论AD及MCI存在广泛脑灌注减少;SCD部分脑区存在灌注代偿;HP、TH、FC、PC、OC的CBF值对诊断及鉴别不同阶段AD有一定价值。     

腹腔镜根治性子宫切除术与开腹根治性子宫切除术治疗宫颈癌的临床效果及促进患者恢复的可行性

目的 比较腹腔镜根治性子宫切除术与开腹根治性子宫切除术治疗宫颈癌的临床效果及促进患者恢复的可行性.方法 回顾性分析2018年1月至2020年1月本院收治的86例宫颈癌患者的临床资料,依据手术方法 将患者分为腹腔镜组(n=43,腹腔镜根治性子宫切除术)与开腹组(n=43,开腹根治性子宫切除术).比较两组的手术指标、淋巴结...