磁场对恶性肿瘤生长的抑制作用

宿主和恶性肿瘤之间的相互作用和生物电磁现象有关。磁场影响肿瘤生长的报道较多,由于磁场的生物效应及其机制都很复杂,进一步研究工作是需要的,我们观测到一定参数的脉冲梯度磁场在不同生物层次上抑制鼠恶性肿瘤生长,磁场诱发癌细胞凋亡和阻塞供应肿瘤的新生血管,由于脉冲梯度磁场抑制癌生长,所以它能成为一种辅助治疗癌症的新方法。     

试论磁场治疗恶性肿瘤中的三对矛盾凋亡与增殖免疫与肿瘤阻塞与供给

脉冲梯度磁场(峰值磁场0.2~2.0T,梯度10~100T.M-1,脉冲宽度20~200ms,重复频率0.16~1.34HZ)抑制鼠恶性肿瘤的细胞增殖和诱导细胞凋亡,提高宿主细胞免疫功能和抑制肿瘤生长,阻塞供给肿瘤生长的新生血管。虽然进一步的清晰的机理研究是非常需要的,但是上面的发现能够成为治疗恶性肿瘤的一种新方法。     

超低频脉冲梯度磁场诱导癌细胞凋亡和抑制癌细胞生长实验研究

观测到磁场诱导鼠癌细胞凋亡的形态特征. 凋亡的癌细胞收缩变圆, 与周围细胞脱离; 异染色质浓缩, 沿核膜内侧排列, 凝结成块; 内质网池状水肿并与细胞膜融合; 出现许多被膜包裹的凋亡小体; 凋亡小体被一些淋巴细胞、浆细胞吞噬. 用原位缺口末端标记法(TUNEL)测定癌细胞凋亡, 发现磁场治疗组的凋亡癌细胞的数目明显大于对照组. 在超低频脉冲梯度磁场作用下, 抑制鼠恶性肿瘤生长和提高免疫细胞的溶癌能力, 核DNA倍性减少, 揭示磁场能阻碍DNA复制, 抑制癌细胞分裂与代谢, 降低其恶性程度和抑制其高速与异形生长.     

超低频脉冲磁场诱导癌细胞凋亡机理研究

我们研究超低频脉冲磁场(峰值0.6~2.0T,梯度10~100T.m-1,脉冲宽度20~200ms,重复频率0.16~1.34HZ)作用于鼠S-180肉瘤。在电镜下观察到肉瘤细胞程序性死亡的许多特征。这一磁场引起约1.5mv的跨膜电位变化,导致钙离子Ca2+内流,促使癌细胞凋亡。磁场对运动电荷的洛仑兹力使运动的带电粒子束缚在拉莫尔(Larmor)半径以内,影响正负带电离子对细胞膜和核膜的渗透能力,甚至在膜上形成空洞。     

ELF磁场对3T3细胞生长的影响及其机理的探讨

用细胞分析成像光盘记录系统测量了3T3细胞在某些ELF磁场和温度条件下生长周期的变化.实验结果表明,只有某些频率的ELF磁场才对细胞生长产生影响,磁场对细胞生长的影响还与培养细胞的生化环境有关.温度和ELF磁场都能影响细胞的生长.但二者的机理是不一样的,当撤除ELF磁场后,细胞在短时间内(2天以上)继续保持着ELF场对其生长的影响.而细胞生长周期能在短时间内(2天以内)随着温度的变化而变化.温度引起的细胞生长的变化可能与细胞内的各种生长因子、生物离子的活性有关.ELF磁场引起的细胞生长的变化可能与ELF磁场对细胞膜的影响有关,与细胞内细胞生长必不可少的生物离子(如Ca~(2+))的浓度有关.     

稳恒磁场联合抗肿瘤药物协同杀伤肝癌细胞Hepa1-6

化学疗法为肿瘤临床治疗的常规方法,存在毒副作用大、抗药性强等缺陷。为了提高药物的利用效率,减少药物引起的毒副作用,将8.8 m T稳恒磁场分别与顺铂、阿霉素联用,经MTT检测发现磁场与药物联用可对肝癌细胞Hepa1-6生长具有协同抑制的效应,经HE染色发现联合处理组细胞发生明显的形态学改变。流式细胞仪检测显示磁场能增加顺铂对G2/M期细胞的滞留,而磁场与阿霉素共同作用可将细胞阻止于G1期和G2/M期。经彗星电泳检测表明磁场能够增强药物对DNA的损伤,且原子力显微镜观察发现联合处理组细胞膜表面出现较大且较深的孔洞,表面结构破坏严重。实验结果表明,抗肿瘤药物与磁场联用技术可有效抑制肿瘤细胞的生长,减少药物的使用浓度,为将抗肿瘤药物与磁场应用于临床治疗恶性肿瘤提供了一个全新的思路与策略。     

超低频脉冲磁场抑制癌瘤和提高细胞免疫功能的实验研究

在报道用电子显微镜观测超低频脉冲磁场(峰值磁场0.6～2.0T,磁场梯度10～100T·m^-1,脉冲宽度20～200ms,重复频率0.16～1.34Hz)抑制鼠S-180肉瘤和加强免疫细胞溶癌作用以后,报道了用Faulgen染色法测定肉瘤细胞核的DNA倍性,和用电镜技术和细胞结构的体视学分析磁场对癌细胞形态的影响,观测到磁场影响癌细胞的代谢:磁场使癌细胞的恶性程度降低,抑制其高速和异形生长;磁场抑制癌细胞的分裂和DNA的复制;磁场提高细胞免疫功能,加强淋巴细胞、浆细胞反应.     

磁场对肿瘤细胞的抑制作用

目的 :用磁场进行小鼠荷瘤和人体的离体癌细胞抑制试验。方法 :用装备有NdFeB永磁材料的仪器产生非均匀磁场 (磁通密度为 0 .2 0T ,梯度为 0 .0 7T/cm)对荷瘤小鼠和人体的离体癌细胞每天作用0 .5小时 ,1 2天后解剖检查试验结果。结果 :磁场对荷瘤小鼠的癌细胞抑止率达 61 % (p <0 .0 0 2 ) ,胸腺平均比化疗组重 8mg(p <0 .0 1 ) ,癌组织的纤维包膜是对照组的 2～ 3倍。谷丙转氨酶 (SGPT)低于化疗组的平均值 (p <0 .0 0 1 ) ,肝、心肌细胞无损伤 ;白细胞 (WBC)高于化疗组的平均值 (p <0 .0 2 ) ,免疫功能提高 ;血红蛋白 (Hb)低于化疗组的平均值 (p <0 .0 5 ) ,局部缺氧 ,癌细胞呈片状坏死 ,部分癌组织呈孤岛状。磁疗组无明显毒副作用反应。重复性实验结果相近。小鼠和人体离体癌细胞实验显著性检验无显著性意义。结论 :磁场在一定的梯度范围是可以有效的抑制小鼠肿瘤的生长。     

极低频率（ELF）磁场对细胞生长周期分布谱的影响及其机理的计算机模拟分析

测定在各种温度条件下和在ＥＬＦ（极低频率）磁场作用下细胞生长周期分布谱的变化。实验结果表明温度不仅能使周期分布谱的离散性发生改变,而且也能使谱的峰值产生位移,而ＥＬＦ磁场只能使周期分布谱的离散性发生变化,对谱的峰值没有显著影响。这一差异是由于温度和ＥＬＦ磁场对细胞生长产生影响的机理不同。用计算机模拟不同机理对细胞生长周期分布谱的影响与我们早先提出的机理相吻合,即温度影响细胞内各种生长因子、生物离子的活性,而ＥＬＦ磁场则可能通过对细胞膜的影响使细胞内的细胞生长必不可少的生物离子的浓度发生变化。     

脉冲电场和磁场对高血粘和高凝血影响的比较研究

比较研究脉冲电场和脉冲磁场对高血粘和高凝血的影响,探寻降低血液粘度,抑制凝血过快、过强的物理方法.每份血样等分9份,1份作对照,对另外8份分别作不同的脉冲电场或磁场处理.结果显示不同上升沿速率的脉冲电场和磁场对高血粘和高凝血的影响程度不同,上升沿速率为2.5 × 105T s-1的脉冲磁场使全血表观粘度η降低(P＜0.01)、复钙凝血时间tr变长(P＜0.01),血块的最大剪切应力τax变小(P＜0.01).脉冲磁场作用能改善高血粘和高凝血状况.     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).