香烟烟雾水溶物对人外周血淋巴细胞SCE的影响

SCE频率分析是研究环境诱变剂和致癌剂引起人类遗传物质损伤的有效手段。本文以人外周血淋巴细胞姐妹染色单体交换(SCE)为指标,研究了香烟烟雾水溶物对体外培养的人外周血淋巴细胞SCE的影响。结果表明香烟烟雾水溶物引起人的外周血淋巴细胞SCE数的增加,证明香烟烟雾水溶物具有诱发突变作用。     

ELF脉冲电磁场对脑组织钙离子迁移量的影响

目的研究极低频(extremely low frequency,ELF)脉冲电磁场对脑组织钙离子迁移量的影响。方法以鸡脑组织为生物学实验对象,以同位素示踪法为标记方法,用液体闪烁计数器为检测仪器,实验观察ELF脉冲电磁场对脑组织钙离子迁移量的影响。结果不同特征外加ELF脉冲电磁场对脑组织钙离子迁移量影响不同,如频率为16 Hz、场强为42.5 V/m的ELF脉冲电磁场可引起脑组织钙离子迁移量显著变化。频率为16 Hz、场强为62.2 V/m与频率为31 Hz、场强为42.5 V/m的ELF脉冲电磁场却未引起脑组织钙离子迁移量显著改变。结论只有频率和强度恰当组合的ELF电磁场才可引起脑组织钙离子迁移量显著升高,呈现出生物学窗效应。另一方面在既注重物理学分析又注重生物系统特性基础上,从膜通道内的带电粒子动力学方程入手分析讨论生物学窗效应产生机制。     

脉冲电磁场对模拟高原环境小鼠肝脏氧化应激的影响

目的:探究脉冲电磁场对模拟高原环境下小鼠肝脏氧化应激的影响。方法:将15只雄性SPF级小鼠平均随机分为平原对照组（Control组）、低压低氧组（HH组）和脉冲电磁场干预组（PEMF组）,HH组和PEMF组置于低压低氧舱内模拟海拔6 000 m,构建小鼠肝脏氧化应激模型。其中PEMF组每天施加2 mT磁场干预2 h。实验进行5 d后处死小鼠取材,对肝组织的氧化应激生化指标进行检测,并对抗氧化酶活性蛋白表达进行检测。结果:与HH组相比较,PEMF组丙二醛和氧化型谷胱甘肽水平显著降低,而还原谷胱甘肽水平显著上升;与HH组比较,PEMF组谷胱甘肽过氧化物酶活性显著上升,与蛋白表达活性相一致。结论:脉冲电磁场可以改善模拟高原环境引起的小鼠肝脏氧化应激失衡,显著提高谷胱甘肽过氧化物酶活性。     

Comparative investigations of the genotoxic effects of metals in the single cell gel (SCG) assay and the sister chromatid exchange (SCE) test

Sodium arsenite (NaAsO₂) and cadmium sulphate (CdSO₄) were tested for their ability to induce genotoxic effects in the single cell gel (SCG) assay and the sister chromatid exchange (SCE) test in human blood cultures in vitro. Both metals induced DNA damage in white blood cells that was expressed and detected as DNA migration in the SCG assay. Dose dependent effects were seen for cadmium in concentrations from 5 × 10^?4-5 × 10^?3 M and for arsenic in concentrations from 2 × 10^?4-1.5 × 10^?3 M. The distribution of DNA migration among cells, a function of dose, revealed that the majority of exposed cells expressed more DNA damage than cells from control cultures and that with increasing length of DNA migration the variability in migration among cells increased as well. Treatment of cells for 2 hr or 24 hr beginning 48 hr after the start of the blood cultures did not increase the SCE frequency in the case of cadmium but caused a small but significant SCE induction with arsenic at the highest concentration. The metal concentrations which could be investigated in the SCE test were much lower due to a strong toxic effect. Metal concentrations which were toxic in the SCE test were without visible effect in the SCG assay. Thus the two endpoints for the determination of genotoxic effects in vitro differed markedly with respect to the detection of genotoxicity induced by metals. These differences and the biological significance of the findings are discussed. © 1994 Wiley-Liss, Inc.     

Comparison of the long-term effectiveness of physiotherapy programs with low-level laser therapy and pulsed magnetic field in patients with carpal tunnel syndrome

PurposeThe aim of the study was to compare the long term effects of low - level laser therapy (LLLT) and pulsed magnetic field (PMF) in the rehabilitation of patients with carpal tunnel syndrome (CTS).MethodsThe study included 38 patients with idiopathic CTS, confirmed by electroneurographic (ENG) examination. All patients were randomly assigned to 2 groups: group L (18 patients) treated with LLLT and group M (20 patients) with PMF therapy. Clinical assessment, including day and night pain, the presence of paresthesia, functional tests (Phalen, Tinel, armband tests) and pain severity according to the Visual Analogue Scale (VAS) was conducted before treatment, after the first series of 10 sessions, after a two-week break, after the second series of 10 sessions and six months after the last series.ResultsAfter LLLT a significant reduction of day and night pain was observed at each stage of treatment and 6 months after the last series (p<0.05). However, in group M, a significant reduction of both day and night pain was demonstrated only after the second series (p<0.05). A reduction of the incidence of Phalen's symptoms were noticed in both groups, however, only in group L the improvement was significant (p<0.05). In groups L and M a significant reduction of pain intensity was observed at every stage of treatment (p<0.05).ConclusionsAlthough after LLL as well as PMF therapy clinical improvement was observed, the most significant differences were registered after the second series and persisted for up to 6 months in both groups.     

A strategy for controlling degradation in vitro of carbon fiber-reinforced polylactic acid composites (by combining fiber modification and pulsed electromagnetic fields)

Abstract

Carbon fiber-reinforced polylactic acid (C/PLA) composites are a human bone-fixation material, but control of the material’s degradation remains a major factor hindering its widespread use. In this study, a combined method for controlling the degradation performance in vitro of C/PLA composites was designed. In this strategy, carbon fibers for C/PLA composite reinforcement were prepared in both modified and unmodified forms. A pulsed electromagnetic field (PEF) was then selectively applied during the subsequent degradation process. Results and analysis showed that the interfacial ester bonding between modified carbon fibers and PLA matrices significantly affected degradation in vitro of C/PLA composite. However, PEF affected the degradation performance of C/PLA composites and, after PEF treatment, the material's water absorption, mass retention, and bending and shearing strengths were changed to varying degrees. This method, by combining fiber modification and pulsed electromagnetic fields (abbreviated as CMP) provided a new strategy for the controlled degradation of C/PLA composites in human skeletal fixation.     

不同培养基对人脐静脉内皮细胞体外培养效果的影响

目的研究不同培养基对人脐静脉内皮细胞体外培养生长的影响,探讨内皮细胞的最佳体外扩增培养条件。方法取健康产妇分娩后脐带,用胶原酶Ⅰ消化后得脐静脉内皮细胞,进行原代培养,并用免疫荧光染色的方法对细胞进行鉴定,传代培养时则分别采用RPMI-1640培养基和EGM-2培养基,倒置显微镜观察两种培养条件下细胞的生长状态,同时利用流式细胞仪检测其生长周期,对比培养效果。结果 EGM-2组内皮细胞生长良好,2d后贴壁生长的细胞可达90%。EGM-2组S期细胞比例为（29.07±1.48）%,RPMI-1640培养基组S期细胞为（17.58±3.49）%,二者比较差异有统计学意义（P〈0.01）。结论 EGM-2培养基更适合人脐静脉内皮细胞的体外传代扩增培养。     

Action of a modulated electromagnetic field on experimentally evoked epileptiform brain activity in rats

The effect of a modulated electromagnetic field (MEMF) on experimentally evoked epileptiform activity of brain structures was studied in rats. Exposure to an MEMF with modulation frequencies of 2–30 Hz was shown to induce depression of paroxysmal brain electrical activity in 41% of experiments. Marked weakening of epileptiform activity was observed in 23% of experiments and potentiation in 10.1%. In 25% of experiments exposure to an MEMF did not significantly alter the character of evoked paroxysmal brain activity.Laboratory of Emotions and Emotional Stresses, P. K. Anokhin Institute of Normal Physiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 1, pp. 145–148, February, 1980.     

脉冲电磁场防治骨质疏松的动物实验装置研制及实验观察

目的根据脉冲电磁场治疗骨质疏松的原理，设计用于动物实验的脉冲电磁场治疗装置．并用该装置观察在脉冲电磁场作用下实验动物力学特性和骨组织形态的变化。方法设计了强度为11MT．频率12Hz／8Hz自动跳变的脉冲电磁场发生装置和专用的动物实验装置，并将磁场作用于去势大鼠的骨质疏松模型。结果实验装置运行时．对各参数检测表明，实验装置满足设计的要求：经脉冲电磁场装置治疗的大鼠骨形态和力学特性与未经治疗的模型组都有明显改善。结论实验装置满足设计要求，脉冲电磁场可以改善骨的形态和骨骼的力学特性。     

Chromosomal aberrations induced by in vitro irradiation: comparisons between human sperm and lymphocytes

Types and frequencies of structural aberrations in human sperm and lymphocyte chromosomes from one donor were compared after in vitro irradiation with 100, 200, and 400 rad in order to determine if cells with dramatically different chromatin configurations are similarly affected and to investigate the feasibility of using lymphocytes as surrogates for germ cells in risk estimation. Sperm chromosomes were analyzed after fusion with eggs from the golden hamster. Total frequencies of induced aberrations were similar in the two cell types. However, the relative frequencies of rejoined lesions (dicentrics), compared with unrejoined lesions (chromosome breaks and acentric fragments), were different. At the three doses tested, a constant ratio of 5 dicentrics in lymphocytes for every dicentric in sperm was induced. Conversely, for every chromosome break or acentric fragment induced in lymphocytes, 1.7 such events were induced in sperm at the three doses tested.     

雷帕霉素对人CD4~+CD25~+调节性T细胞体外扩增的影响

探讨有效的体外扩增人CD4~+CD25~+调节性T细胞(Treg)的方法以及雷帕霉素(rapamycin,RAPA)对人CD4~+CD25~+Treg细胞体外扩增的影响。采用免疫磁珠分离人外周血的CD4~+CD25~+Treg,并将实验分为3组:第1组在CD4~+CD25~+Treg培养体系中加入200 U/ml IL-2和包被CD3/CD28单克隆抗体的磁珠;第2组培养体系中除加入100 nmol/LRAPA以外,其余与第1组相同;第3组是CD4~+CD25~+Treg培养第12天后,将细胞进一步分选获取CD4~+CD25~+CD127~- Treg再继续培养,培养体系与第2组相同。实验结果显示,加RAPA培养的CD4~+CD25~+Treg细胞扩增效率比不加RAPA的低,但细胞的纯度明显提高(92%vs 65%)。而加RAPA培养的第2、3组CD4~+CD25~+Treg细胞在纯度上没有明显的差异。加RAPA培养的CD4~+CD25~+Treg细胞扩增后保持其无能状态。体外抑制实验显示体外扩增的CD4~+CD25~+Treg细胞对CD4~+效应T细胞增殖均有明显的抑制作用,而且加RAPA扩增的Treg细胞表现出更强的抑制功能。另外,与第1组体外扩增的Treg细胞相比,加RAPA扩增的Treg细胞表达低水平的IL-2和IFN-γ。实验证明雷帕霉素抑制了CD4~+ CD25~+Treg细胞中混杂的CD4~+效应T细胞的扩增,使用雷帕霉素可以提高体外扩增CD4~+CD25~+Treg细胞的纯度及其免疫抑制功能。     

Confirmation of the chromosome damaging effects of lamivudine in in vitro human peripheral blood lymphocytes

The aim of this study was to investigate genotoxic effects of lamivudine (an analogue of cytidine) using in vitro sister chromatid exchange (SCE), chromosome aberration (CA), and micronucleus (MN) tests in human peripheral lymphocytes. The cells were treated with 75, 100, 125, and 150 microg/ml concentrations of lamivudine (roughly 30-60 times higher than plasma levels achieved in patients receiving this drug) for two (24- and 48-hr) treatment periods. Lamivudine induced SCEs at the highest concentration (150 microg/ml) in the 24-hr treatment, and at 125 and 150 microg/ml in the 48-hr treatment, when compared to the solvent control. During both treatment periods, structural chromosome aberrations were significantly increased at 100, 125, and 150 microg/ml lamivudine concentrations. However, the increases of SCEs (22%) and CAs (50%) were weak. In addition, lamivudine reduced both the proliferation index (PI) and the mitotic index (MI) significantly at all concentrations for the two treatment periods. The MI was reduced by lamivudine in a dose-dependent manner during both the 24- and 48-hr treatment periods. In contrast, the PI was reduced by lamivudine only during the 48-hr treatment period. A weak but significant increase in MN formation was observed following lamivudine treatment at 100, 125, and 150 microg/ml for 48 hr, but no significant increase in micronuclei were observed following 24-hr treatment. In conclusion, lamivudine has a weak genotoxic effect at elevated doses on human peripheral lymphocytes.     

不同频率脉冲电磁场对人卵巢癌SKOV3细胞增殖、凋亡及迁移的影响

研究不同频率的脉冲电磁场(PEMF)对人卵巢癌SKOV3细胞增殖、凋亡和迁移的影响,为PEMF治疗或预防卵巢癌切除术后发生骨质疏松患者的安全性提供实验参考数据。分别对体外培养的人SKOV3细胞施加不同频率(8、16、32和64Hz)、固定强度为1mT的PEMF,2次/d,30min/次,间隔12h,共3d,以未施加PEMF的细胞作为对照组。分别采用EdU荧光法、Annexin V-FITC荧光法和划痕实验检测SKOV3细胞增殖、凋亡及迁移的情况。结果:频率8Hz的PEMF能明显抑制SKOV3细胞的增殖,并诱导其凋亡。频率8Hz和32Hz的PEMF能明显促进人卵巢癌细胞SKOV3的迁移,而频率16Hz的PEMF却明显地抑制SKOV3细胞的迁移。提示不同频率的PEMF对人卵巢癌细胞SKOV3增殖、凋亡及迁移的影响不同。在临床中对于卵巢癌切除术后的骨质疏松患者,应当慎重考虑PEMF治疗的安全性,并严格选择治疗参数。     

Immunization of human lymphocytes with Epstein-Barr virus capsid antigens in vitro

Research Center for Development and Introduction of Modern Methods of Molecular Diagnosis, Ministry of Health of the USSR, Moscow. (Presented by Academician of the academy of Medical Sciences of the USSR A. I. Borob'ev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 111, No. 1, pp. 62–64, January, 1991.     

Effect of mangiferin on radiation-induced micronucleus formation in cultured human peripheral blood lymphocytes

Irradiation causes a variety of lesions in important biomolecules of the cell through generation of free radicals leading to genomic instability. DNA strand breaks, acentric fragments, or defective kinetochores are manifested as micronuclei after the first cell division. Chemicals that can trap free radicals may reduce the deleterious effects of ionizing radiation. Mangiferin (MGN), a glucosylxanthone derived from Mangifera indica (mango), was investigated for its ability to reduce the frequency of radiation-induced micronucleated binucleate cells (MNBNCs) in cultured human peripheral blood lymphocytes (HPBLs). HPBL cultures were pretreated with 0, 5, 10, 20, 50, and 100 microg/ml of MGN for 30 min before exposure to 3 Gy of (60)Co gamma-radiation. The maximum decline in radiation-induced micronuclei was observed at a concentration of 50 microg/ml MGN; thereafter, a nonsignificant elevation in MNBNC frequency was observed at 100 microg/ml MGN. Since the lowest MNBNC frequency was observed for 50 microg/ml MGN, dose-response studies were undertaken using this concentration. Irradiation of HPBLs with 0, 1, 2, 3, or 4 Gy of gamma-radiation caused a dose-dependent elevation in the MNBNC frequency, while treatment of HPBLs with 50 microg/ml MGN 30 min before radiation resulted in significant declines in these frequencies. MGN alone did not alter the proliferation index. Irradiation caused a dose-dependent decline in the proliferation index, while treatment of HPBLs with 50 micro/ml MGN significantly elevated the proliferation index in irradiated cells. MGN treatment reduced hydrogen peroxide-induced lipid peroxidation in HPBLs in a concentration-dependent fashion. In cell-free studies, MGN inhibited the induction of (.)OH (hydroxyl), O(2) (.-) (superoxide), DPPH (1,1-diphenyl-2-picrylhydrazyl), and ABTS(.+) (2,2-azino-bis-3-ethyl benzothiazoline-6-sulphonic acid) radicals in a dose-dependent manner. The results of this study indicate that MGN possesses radioprotective properties by suppressing the effects of free radicals.     

In vitro detection of apoptosis using oscillating and pulsed gradient diffusion magnetic resonance imaging

Cellular apoptosis, a common pathway towards tumor regression, is induced by many radiotherapy and chemotherapy regimens. Imaging methods that can detect apoptosis may be able to assess treatment response earlier than typical tumor volume measurements. In this paper, a wide range of diffusion experiments and a simple model of diffusion in tissues were used to probe the microstructural effects of apoptosis. Experiments were conducted on acute myeloid leukemia cell pellets, where apoptosis was induced by treatment with the chemotherapeutic agent cisplatin. Seventy‐two hours following cisplatin treatment, pulsed and oscillating gradient diffusion measurements were utilized to assess effects across a broad range of structural scales. The presence of apoptosis, which was histologically confirmed by TUNEL (terminal deoxynucleotidyl transferase UTP nick end labelling) staining, significantly changed diffusion properties. To describe these changes, the data were fit to the parallel plane model, which characterizes the effects of restricted diffusion in terms of three parameters: d, the restricted size, D_free, the intrinsic, free diffusion coefficient of the solvent, and D_rest, the long time or “restricted” diffusion coefficient. Apoptotic samples exhibited significant decreases in parameters d and D_free and a significant increase in D_rest. These changes appear consistent with the established morphological effects of apoptosis. In particular, the decrease in d may be a result of the combined effects of cell shrinkage, nuclear fragmentation and membrane blebbing, the decrease in D_free may relate to cytosolic condensation, while the increase in D_rest can be attributed to increased membrane permeability and extracellular volume fraction. By non‐invasively detecting apoptosis, the methods reported in this study have the potential to improve upon current MRI methods for monitoring therapeutic response. Furthermore, these methods may offer sufficient specificity to differentiate between apoptosis and other modes of cell death, such as oncosis or necrosis. Copyright © 2014 John Wiley & Sons, Ltd.     

Homocysteine accumulates in supernatants of stimulated human peripheral blood mononuclear cells

Moderate hyperhomocysteinaemia is associated with atherosclerosis, thrombosis and also with stroke and dementia. Elevated homocysteine concentrations are related to deficiency of folate and also vitamin-B12, as these two vitamins are essential co-factors in the remethylation of homocysteine to methionine. A causal role of homocysteine in the pathogenesis of vascular disease has been discussed over years. Immune activation appears to be involved strongly in atherogenesis as well as in other diseases found to be associated with moderate hyperhomocysteinaemia. To study a possible influence of immune stimulation on homocysteine metabolism, in vitro experiments were performed using peripheral blood mononuclear cells upon stimulation with mitogens concanavalin A, phytohaemagglutinin and pokeweed mitogen. In stimulated cells a dose-dependent increase of homocysteine concentrations was found. When cells were kept in medium supplemented with methionine, homocysteine concentrations increased further, while supplementation with folate had only a slight effect. We conclude that in supernatants of stimulated peripheral blood mononuclear cells homocysteine is accumulating. T cell activation could be involved in the development of moderate hyperhomocysteinaemia.     

温度开环和闭环反馈在高压脉冲电场消融中的对照研究

目的:对比温度开环和闭环反馈在高压脉冲电场消融中的区别。方法:温度开环组应用高压方波脉冲发生器以场强1.5 kV/cm、频率1 Hz、脉宽100 μs、脉冲数20个的条件对细胞悬液、3D细胞模型和离体猪肝组织3种不同负载施加高压脉冲电场。闭环组在相同脉冲条件下增加温度闭环算法对微控制器及温度传感器编程控制脉冲发放。分别从电场消融后的电极温度、细胞悬液电导率和细胞死亡率,3D细胞模型消融截面积以及猪肝组织消融区病理特点进行定量比较和定性分析。结果:消融后开环组电极温度、细胞悬液电导率、细胞死亡率和3D细胞模型消融截面积分别为（53.2±5.5）℃、（1.43±0.03） S/m、（86.8±5.5）%和（0.46±0.15） cm2,均高于闭环组对应的（38.5±1.6） ℃、（1.21±0.02） S/m、（73.6±10.2）%和（0.37±0.08） cm2,差异均有统计学意义（P<0.05）;开环组消融区猪肝组织H-E染色可见热损伤导致的凝固性坏死区,闭环组表现为肝血窦增宽、细胞质脱水丢失和核聚集。结论:该实验条件下,温度开环和闭环反馈高压脉冲电场消融存在差异。传统温度开环高压脉冲电场消融效果略强于温度闭环,这可能与电导率增加和热效应介导的电场杀伤效应增强有关。温度闭环反馈能避免热损伤效应,实现真正意义上的非热性消融。