不同类型磁场对细胞作用的生物学研究

本文就不同参数的磁场的细胞生物学效应研究进行了综述 ,总结了不同类型不同物理参数的磁场对细胞生物学效应的研究成果 ,结合实验结果对磁场生物学效应的可能物理机制进行了初步探讨 ,并对磁场的细胞生物学效应的研究前景进行了展望。     

磁场对酶学效应影响的研究进展

本文就近年来国内外关于脉冲磁场和恒定磁场对于生物体内各种酶的活性、构象、酶促反应动力学的效应的研究进行了综述。     

磁生物学效应的研究进展

磁场作用于生物体后产生一系列的生物学效应,这种观点已被多年来的许多实验所证实。早在1896年,磁场对神经系统作用的研究就已被报道。后来,磁场抗炎,促进骨生成,促进血管神经再生等作用相继被发现。近几十年来,关于磁场对生物体的作用,从流行病学调查到实验室研究也都有了一定进展。如今,磁场的生物学效应研究已成为物理医学研究的热点。本文就近年来磁场生物学效应研究的热点与进展作一简要综述。     

磁场的生物学效应及其机理的研究

本文就不同参数的磁场的生物学效应研究进行了综述,总结了磁场对生命体整体、组织、器官、细胞直至生物大分子层面上的研究成果,并结合实验结果对磁场生物学效应的可能物理机制进行了初步探讨,并对磁场生物学效应的研究前景进行了展望。     

Protective Effects of Moderate Intensity Static Magnetic Fields on Diabetic Mice

The purpose of this study was to investigate the effects of moderate-intensity static magnetic field (SMF) on diabetic mice. We studied the effects of SMF on blood glucose of normal mice by starch tolerance and glucose tolerance tests. Then, we evaluated the effects of SMF on blood glucose of diabetic mice by establishing alloxan-induced type 1 diabetic mice and high-fat diet + streptozotocin (STZ)-induced type 2 diabetic mice. The results showed that different magnetic field intensities and blank control did not affect the blood glucose of normal mice. After starch and glucose administration, different magnetic fields could improve the glucose tolerance of normal mice, and this was obvious in the 600 mT group. In the experiment of type 1 diabetic mice induced by alloxan, the results showed that different magnetic field intensities could improve the starch tolerance of mice, and that in the 400 mT group was obvious. In the experiment of type 2 diabetic mice induced by a high-fat diet + STZ, the 400 mT group could reduce food intake and water consumption in the later period. The 600 mT group could improve the starch tolerance of mice. The 400 and 600 mT groups could reduce fasting blood glucose. At the same time, total cholesterol and triglyceride decreased in different magnetic field intensities, and the 600 mT group could significantly increase the serum insulin content of mice. In summary, the results of this study suggest that SMF has a protective role in diabetic mice. Bioelectromagnetics. © 2020 Bioelectromagnetics Society     

恒定磁场对大肠杆菌生长繁殖影响

目的:研究恒定磁场在静态处理和动态处理两种处理方式下对大肠杆菌生长繁殖的影响.方法:将处于对数生长期的大肠杆菌茵液置于磁场中(静态处理)或使菌液循环流动并通过磁场(动态处理),用平板法测定不同时刻菌液的活菌数,记录下菌落形成单位(CFU)的数目,并与相应时申刻对照样(无磁处理)的CFU作对比.结果:两种处理方式下,菌液的相对CFU的数目都有下降.且动态处理的下降幅度大于静态处理.结论:恒定磁场在两种处理方式下都对大肠杆菌起到明显的杀死或抑制作用.文章的讨论部分总结了产生这种作用的可能机理.     

300 mT恒磁场对于糖尿病大鼠创伤愈合的影响

目的:研究300mT恒磁作用对于糖尿病大鼠皮肤创伤愈合的修复效果,旨在为其系统的临床应用提供理论依据.方法:8周龄雌性SD大鼠,体重220±20g,行腹腔注射50mg/kg链脲做菌素,3天后空腹血糖高于16.7 mmol/L的大鼠用于实验.32只糖尿大鼠病和16只正常大鼠的背部构建直径2cm的圆形创口,将动物随机分为对照组、糖尿病组、糖尿病恒磁场作用组,每组16只,术后一天采用无菌纱布将创口进行包裹,磁场作用组的纱布表面粘附有300 mT中心场强的钕铁硼恒磁片.分别于第6、13、20天每组处死4只大鼠,对其进行创伤愈合率和创伤表皮组织生物力学实验评估.结果:相比于糖尿病组,糖尿病恒磁场治疗大鼠的伤口愈合速度在第6、13、20天显著提高(P＜0.05),伤口组织的抗张强度亦显著提升(P＜0.05),其愈合速度接近于正常状态下的大鼠.结论:300mT恒磁场作用对于促进糖尿病大鼠皮肤创伤的愈合速率具有积极的治疗作用,恒磁场治疗凭借经济、简单、方便等特点,具有广阔的临床应用前景.     

磁场对大肠杆菌生长影响的研究

通过对在外加恒强磁场与正常情况下培养的大肠杆菌的生长曲线的测定及对比分析,发现外加磁场能影响大肠杆菌正常的生长并能使其世代周期延长。     

静态磁场对细菌存活率的影响*

细菌污染是食品生产的重要危害,而高强度磁场对细菌的生长有一定的抑制作用,可望用于细菌对食品的危害控制。通过研究静态磁场强度和磁场处理时间对细菌存活率的影响,探讨了静态磁场对细菌的作用规律,并对磁场处理前后的细菌进行了DNA图谱分析。研究结果可为磁场处理技术在食品工业上的应用提供初步理论分析和实验依据。     

磁场对急性胃损伤的治疗效应及其机制的实验研究

目的：探讨腹部恒磁场作用,对大鼠急性胃损伤模型的治疗效应及其作用机制.方法：10只健康SD大鼠,以indomethacin胃灌注法复制急性胃损伤模型,以表面磁强度为1300-1600GS,钡铁氧体恒磁场作用大鼠腹部3小时,观察胃损伤指数及病理损伤积分,同时对血浆中内皮素（endothelin,ET）、一氧化氮（nitric oxide,NO）、谷胱甘肽过氧化物酶（GSH-Px）及超氧化物岐化酶（SOD）水平进行比较.结果：恒磁场腹部作用后,大鼠胃损伤指数及病理损伤积分较对照组均显著减轻（p均〈0.05）;血浆ET-1和NO水平却无无明显改变（p均〉0.05）,血GSH-Px和SOD含量较对照组均明显升高（p均〈0.05）.结论：腹部1300-1600GS恒磁场作用3小时,对大鼠急性胃损伤具有明显的治疗效应,磁场的这一效应可能与其增加血浆中清除氧自由基的GSH-Px和SOD活性有关.     

Moderate Intensity Static Magnetic Fields Prevent Thrombus Formation in Rats and Mice

We established three types of thrombosis models to explore the effects of the static magnetic field (SMF) on thrombosis in rats and mice with three different MF intensities. In the carrageenan-induced thrombosis model in rats, the SMF treatments reduced the black tail length of rats, extracorporeal thrombus, and the mass of wet and dry thrombus, and improved the coagulation index value. In FeCl₃-induced arterial thrombosis model in rats, the SMF treatment showed some anti-thrombotic effects. More specifically, the SMF treatment affected rodent blood pressure, plasma plasminogen activator inhibitor, tissue-type plasminogen activator, thrombus mass, and thrombus protein content. In the adrenaline-induced thrombosis model in mice, the SMF treatment had certain effects on the diameter and blood flow velocity of mouse auricle microcirculation in fine veins and arteries. Overall, the highest MF intensities we tested, 20–150 mT, showed a trend of anti-thrombotic effect, indicating that the moderate-intensity SMF might serve as a potential treatment for clot-related diseases in the future. Bioelectromagnetics. 2020;41:52–62 © 2019 Bioelectromagnetics Society.     

不同磁处理方式对小球藻生长的影响

目的：利用恒定均匀磁场研究了不同磁处理方式和磁感应强度对小球藻生长的影响,探索磁处理技术应用于微藻培养的可能。方法：用t检验考察静止磁处理、循环磁处理和磁处理水三种不同的磁处理方式对小球藻生长的影响。结果：静止磁处理和循环磁处理分别在5．15mT和10．35mT范围促进小球藻生长,并且随磁感应强度增强分别从45mT与200mT开始表现出显著抑制生长作用．相同的磁感应强度下静止磁处理比循环磁处理的影响显著。未发现磁处理水对小球藻的生长有显著影响。结论：不同的磁处理方式对小球藻生长有不同的刺激与抑制的强度闽值;0．8T和1．2T磁感应强度处理下比生长速率下降的差别并不明显,说明磁处理的影响在此强度范围趋于稳定;磁处理水无显著影响说明磁场直接对小球藻细胞产生影响。     

低浓度臭氧对小鼠生长发育的影响

目的研究低浓度臭氧对小鼠生长发育的影响。方法实验组小鼠和对照组小鼠分别在15w紫外灯照射产生的低浓度臭氧环境下和正常无臭氧环境下连续饲养7周,观察其体重变化;阴道涂片镜检观察雌性小鼠的动情周期。7周后,取脑、心、肝、脾、肺、肾等组织标本,做组织病理学分析;利用全自动生化分析仪对部分血清生化指标进行测定,利用放免试剂盒对血清性激素水平进行测定。结果实验组雌性小鼠体重与对照组雌性小鼠差异无统计学意义,实验组雄性小鼠体重比对照组雄性小鼠轻;实验组雌性小鼠的动情周期与对照组雌性小鼠差异无统计学意义;实验组与对照组小鼠的组织切片均未发现异常;实验组小鼠的血清生化指标以及血清性激素水平与对照组小鼠差异无统计学意义。结论本实验中紫外灯照射产生的低浓度臭氧对昆明小鼠的生长发育基本无影响。     

静磁场对小鼠黑色素瘤细胞B16生长和氧化应激的影响

目的:利用小鼠黑色素瘤细胞B16,研究静磁场对肿瘤细胞生长和氧化应激的影响,探讨氧化应激介导静磁场影响肿瘤细胞生长的机制,为磁场在肿瘤疾病的治疗中的应用提供理论依据。方法:采用MTT法测定磁场对B16细胞活力的影响;利用流式细胞仪测定静磁场暴露对B16细胞周期分布的影响;利用生物化学方法测定磁场暴露对细胞氧化防御系统相关蛋白酶活性的影响。结果:24 h内50 m T-200 m T静磁场暴露可以抑制B16生长,但超过24 h的磁场暴露可以促进B16生长;100 m T和200 m T静磁场暴露对B16的细胞周期分布没有影响;B16暴露于100 m T和200 m T静磁场48 h,GST活性和GSH/GSSG水平表现为先上升后下降,SOD活性和T-AOC水平先下降后上升,CAT活性没有受到影响。结论:50 m T-200 m T静磁场可以抑制小鼠黑色素瘤细胞B16的生长,诱导肿瘤细胞产生氧化应激。     

Effects of Static Magnetic Fields on the Antioxidant System of Almond Seeds

Russian Journal of Plant Physiology - During the evolutionary process, all living cells experience natural magnetic fields (geo-magnetic fields) as a usual part of their environment. Living...     

Effects of Continuous and Intermittent Magnetic Fields on Oxidative Parameters In vivo

Continuous and intermittent 50 Hz, 1.5 mT magnetic field with the exposure period of 4 h/day for 4 days was used to investigate its possible effect on adult guinea pigs. Tissues and plasma specimens were assessed by biochemical parameters. Malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels and myeloperoxidase activity (MPO) were examined in plasma, liver and brain tissues. All parameters were determined by spectrophotometer. While intermittent magnetic field was effective on plasma lipid peroxidation, continuous magnetic field was found to be effective on plasma MPO activity and NO levels. Augmentation of lipid peroxidation was also observed in liver tissue both intermittent and continuous magnetic field exposures. These results indicate that both the intermittent and continuous magnetic field exposures affect various tissues in a distinct manner because of having different tissue antioxidant status and responses.     

The Effects of Weak Static Magnetic Field on the Development of Organotypic Tissue Culture in Rats

The effects of weak static magnetic field on the organotypic tissue culture of the rat cerebral cortex, liver, and spleen have been investigated. Exposure to a 200 μT static magnetic field induces tissue development, leading to the intensification of regeneration processes compared to the control explants.     

Absence of Kinetic and Cytogenetic Effects on Human Lymphocytes Exposed to Static Magnetic Fields

Two experiments were performed to assay the influence of static magnetic fields on the kinetics and cytogenetics of lymphocyte cultures. Whole blood aliquots were exposed 3 hrs to 45 mT, after which the lymphocytes were cultured for 72 hrs. In the second experiment, lymphocytes were simultaneously cultured and exposed to 125 mT for 72 or 96 hrs. Some cultures were treated with 5,bromodeoxyuridine (BrdU) to quantify the frequencies of sister chromatid exchanges (SCE) and the percentage of cells that underwent one or more replications. BrdU decreased the mitotic index and raised the ratio of first-generation cells; the effects were dependent on concentration. Exposure to magnetic fields did not significantly change the frequencies of chromosome aberrations, SCE, or polyploidies. The mitotic index and cell generation distribution were unmodified in 8/10 and 7/8 experiments, respectively. The results suggest that moderately strong static magnetic fields do not affect genes.     

卵形鲳鲹血细胞发生的观察

对卵形鲳鲹(Trachinotus ovatus)肝脏、脾脏、头肾和体肾4种组织器官内各种血细胞的发生和外周血液的血细胞分类组成进行了观察。结果表明:卵形鲳鲹的红细胞主要在脾脏、体肾和头肾中发生;淋巴细胞主要在体肾、头肾和脾脏中发生;粒细胞主要在头肾和体肾中发生;单核细胞在肝脏、头肾和脾脏中均有发生;而血栓细胞的发生在这4种组织中均未观察到。卵形鲳鲹在外周血液中的白细胞包括淋巴细胞、血栓细胞、嗜中性粒细胞和单核细胞。在这几种白细胞中,单核细胞数量最少,很难观察到,数量少于1%;嗜中性粒细胞稍多,有(9.25±5.64)%;血栓细胞占(38.23±21.86)%;淋巴细胞最多,达(52.52±21.65)%。     

PPR蛋白在植物生长发育中的作用

PPR蛋白在陆生植物中属于最大的蛋白家族之一,其成员种类和数量均十分庞大。PPR蛋白主要的功能是通过在多种细胞器中进行定位从而参与细胞核和细胞器中特异单链RNA的转录后修饰和编辑,在植物生长发育的多个阶段均发挥着重要的作用。多数PPR蛋白编码基因的突变体呈现异常的发育表型,如胚胎致死、发育迟缓及绿化延迟等。对近年来植物PPR蛋白的分类、定位、RNA修饰的机制及其对植物生长发育影响进行了综述,并展望了植物PPR发挥功能区域和参与的调控网络研究。