A549人肺癌细胞系/615-SCID小鼠转移瘤的生物学特征

目的通过建立A549人肺腺癌细胞/615-SCID小鼠模型,评价重度联合免疫缺陷615-SCID小鼠在建立人类肺癌转移模型方面的应用价值.方法将1×107A549细胞接种到615-SCID及SCID小鼠右上肢背部皮下,观察成瘤时间、成瘤率、肿瘤生长速度及转移发生.结果两品系小鼠接种后的成瘤率均为100%,615-SCID小鼠移植瘤潜伏期较长、生长较缓慢,更容易发生转移.结论 615-SCID小鼠比SCID小鼠更易于构建人类肺腺癌转移模型,对于肺癌转移特性研究具有较大的意义.     

两种人乳腺癌裸鼠移植模型的建立

目的建立简便的人乳腺癌裸鼠移植模型,并探讨其部分生物学特性。方法采用雌激素受体阴性的MDA-MB-231和SK-BR-3人乳腺癌细胞株,分别接种于10只裸鼠左侧腋窝皮下,移植细胞总数为1×107/只。观察肿块生长情况,第42天处死荷瘤鼠,切除肿块作病理切片。结果 MDA-MB-231接种后第5d在接种部位可见结节,成瘤率为90%（9/10）,接种42 d肿瘤体积426.6±333.8,瘤重0.417±0.276,病理学检查为浸润性导管癌;SK-BR-3接种后第11天在接种部位可见结节,成瘤率为80%（8/10）,接种42 d肿瘤体积357.5±246,瘤重0.325±0.167,病理学检查为浸润性导管癌。结论该方法建立的人乳腺癌裸鼠移植模型,皮下移植方法简单,易于操作,成功率较高,肿瘤可部分保持人乳腺癌生物学特性,为研究人乳腺癌提供了重要工具。     

TCR基因修饰淋巴细胞体内抗肿瘤作用的研究

建立荷人肝癌细胞BEL-7402的SCID小鼠模型,用脂质体介导进行基因转染,流式细胞术检测TCRVβ7.1基因表达,分别以尾静脉注射,肿瘤周围皮下注射以及腹腔注射三种方式给予荷瘤免疫缺陷小鼠(SCID鼠)转染TCRVβ7.1基因的人外周血淋巴细胞,24h后处死小鼠取各组织用免疫组化方法来检测淋巴细胞在小鼠体内的分布的情况.通过检测瘤重、肿瘤体积大小,并计算肿瘤抑制率,观察该基因对SCID荷瘤小鼠的抑瘤作用,为该基因用于肿瘤的临床治疗提供动物实验数据.     

不同接种量荧光素酶标记小鼠乳腺癌细胞4T1在小鼠体内生长及肺转移的比较

目的 采用活体成像技术比较四种剂量荧光素酶标记肿瘤细胞在小鼠体内生长及肺转移情况,为光学标记肿瘤模型的药物筛选或机制研究提供参考资料.方法 以荧光素酶作为报告基因导人小鼠乳腺癌细胞4T1中,经G418筛选获得稳定表达荧光素酶的细胞克隆并扩大培养.标记细胞稀释成1×107细胞/mL,2×107细胞/mL,5×107细胞/mL和1×108细胞/mL四种剂量,取0.1 mL接种子BALB/c小鼠右侧第二对乳腺脂肪垫内,制作小鼠原位乳腺癌模型,比较肿瘤细胞在小鼠体内生长及肺转移情况.结果获得稳定表达荧光素酶基因的细胞克隆,在致瘤性方面和亲代细胞无明显差别,四种剂量细胞接种BALB/c小鼠后,均有肿瘤生长,接种第28天时,四种剂量接种的原位移植瘤大小没有明显差别,但接种两个高剂量肿瘤细胞的小鼠组各有2只小鼠死亡;接种后31 d,发现四种剂量接种的原位移植瘤均发生不同程度的转移,随着观察天数的增加,转移程度逐渐严重,接种后42 d,小鼠陆续发生死亡.结论 根据转移和死亡情况,确定接种1×106个细胞/只不仅肺转移明显,而且存活时间一般超过45 d,比高剂量接种存活时间长,为最佳肺转移剂量.     

小鼠Lewis肺癌原位模型的建立

目的利用Matrigel与Lewis制备细胞混悬液注射于小鼠左肺内,建立小鼠Lewis肺癌原位模型,评价其肿瘤生长情况、转移情况,以期建立更稳定、更接近于人肺癌生长情况的小鼠肺癌原位模型。方法将处于对数生长期的Lewis肺癌细胞混悬于Matrigel中,接种于C57BL/6近交系小鼠左肺内。分别于第4、7、10、13、16天各处死5只小鼠,观察其局部成瘤率、肿瘤生长情况、中位生存期及肿瘤转移情况,并对各阶段小鼠行肺部,肝脏,肾脏,脾脏病理切片检查。结果术后第7天解剖的5只小鼠中,3只小鼠肺上可见小的瘤结节形成,其余2只肺上未见肉眼成瘤,行病理HE染色检查在显微镜下可见2只小鼠肺脏有小的瘤结节形成。术后第10天以后处死的所有小鼠肺上均有肉眼成瘤,术后第13天,所有小鼠肺原位成瘤并伴有血性胸腔积液、胸腔内转移。术后第25天,有1只小鼠出现上述转移的同时还出现了心包膜转移及肾脏远处转移。5只小鼠生存期分别为17 d、20 d、22 d、22 d、25 d,小鼠中位生存期为21.2 d（17~25 d）。成瘤率100%。结论利用Matrigel法成功建立小鼠Lewis肺癌原位模型,稳定性好,成瘤率高,并具有远处转移的特性,更接近于人肺癌的发生、发展过程。     

免疫重建荷人膀胱癌 -SCID 鼠模型的建立 *

摘要 目的：探讨建立稳定的荷人膀胱癌 SCID 鼠人化复合型的方法,为在人免疫重建荷人膀胱肿瘤 SCID 鼠型检测重组 BCG 的免疫刺激和免疫保护中打下基础。方法： 经 SCID 鼠腹腔内注射人 PBL、 皮下接种 RT4 膀胱癌细胞, 于接种后 4 周检测 SCID 鼠体内人免疫细咆水平(IgG 和 CD 3+ 、 CD 4+ 、 CD 8+ T 细胞)及脾脏重量, 观察皮下成瘤潜伏期及成瘤率。结果： 型组 100％ 成 瘤,病理类型为移行细胞癌; 检测 SCID 鼠血中人 IgG 均一定水平存在, 与对照组间差异有统计学意义(P<0.01); 人 CD 3+ 、 CD 4+ 、 CD 8+ T 细胞在鼠血及脾中均有表达, 而对照组均未检出(P<0.05); 4 周鼠脾重平均(178.9± 45.2)mg。较对照组(40.6± 14.8)mg 差异 有统计学意义(P<0.01)。结论： 采用腹腔注射人 PBL、 皮下接种 RT4 膀胱癌细胞的方法可以有效地建立人化荷人膀胱癌 SCID 鼠 型, 较好地拟人浸润性膀胱癌体内生物学特性,是膀胱癌免疫基因治疗的较理想型。     

表达人前列腺干细胞抗原小鼠前列腺癌模型的建立

目的探讨并建立可供药物评价或生物学功能研究的表达人PSCA抗原的小鼠肿瘤模型。方法克隆人PSCA基因,构建pcDNA-PSCA质粒,稳定转染RM-1细胞,用RT-PCR和流式检测的方法筛选稳定表达人PSCA抗原的RM-PSCA细胞株;再将RM-PSCA细胞接种C57BL/6小鼠,观察其致瘤性,并寻找能够稳定致瘤的细胞数量;进而观测RM-PSCA所致肿瘤的生长情况及小鼠存活状况。结果筛选到了表达人PSCA抗原的RM-PSCA细胞,且1×105个肿瘤细胞能够保证10只实验小鼠全部成瘤;所致肿瘤生长迅速,接种后小鼠的平均存活时间为37 d。结论该研究成功的建立了稳定表达人PSCA抗原的小鼠肿瘤模型。     

亲骨转移乳腺癌细胞MDA-MB-231BO成瘤性的初步研究

目的通过比较亲骨转移乳腺癌细胞（MDA-MB-231BO）和亲代乳腺癌细胞（MDA-MB-231）的生长曲线和致瘤性,初步探讨MDA-MB-231BO细胞的生物学特性。方法MTT法测定两种细胞的生长曲线,并将两种乳腺癌细胞接种于裸鼠腋窝处皮下,建立乳腺癌细胞异种移植瘤动物模型,30 d后处死裸鼠,肿瘤组织及相关脏器官做病理检查。结果MTT法测得MDA-MB-231BO细胞生长速率高于MDA-MB-231细胞。接种两种乳腺癌细胞的裸鼠均长出肿瘤,成瘤率为100%。病理检查符合人乳腺癌细胞特征,MDA-MB-231BO组瘤体体积明显大于MDA-MB-231组（P〈0.05）。结论MDA-MB-231BO细胞生长速率高于MDA-MB-231细胞,而且MDA-MB-231BO在裸鼠体内的致瘤性强于MDA-MB-231。     

人脐带间充质干细胞体内移植的安全性研究

目的:探讨人脐带间充质干细胞(hUCMSC)的成瘤性及其对荷瘤鼠肿瘤生长的影响。方法:分离培养hUCMSC,取第6代细胞裸鼠皮下移植,观察其成瘤性;对荷瘤鼠尾静脉注射移植hUCMSC,观察其对肿瘤生长的影响;体外共培养hUCMSC和MCF-7肿瘤细胞,观察hUCMSC对MCF-7细胞克隆形成率的影响。结果:hUCMSC裸鼠皮下移植30 d,未观察到有肿瘤形成;尾静脉注射移植hUCMSC对荷瘤鼠肿瘤的生长无明显影响;体外共培养结果表明,hUCMSC对MCF-7肿瘤细胞的克隆形成无明显影响。结论:hUCMSC体内移植无成瘤性;静脉移植后对肿瘤生长无显著影响。     

IRM-2小鼠移植性肿瘤模型的生物学特性

目的观察IRM-2小鼠和C57BL/6小鼠接种Lewis肺癌生物学特性的对比研究。方法取肿瘤组织研磨,用生理盐水稀释成2×10^6/mL,取细胞悬液接种于IRM-2小鼠和C57BL/6小鼠腋下,0.2 mL/只。观察两品系肿瘤生长、荷瘤鼠生存时间,外周血细胞及病理指标变化。结果两品系小鼠成瘤率均是100%,荷瘤鼠存活时间无明显差异,IRM-2小鼠荷瘤鼠体重净增长明显高于C57BL/6荷瘤小鼠（P〈0.05）。白细胞分类及病理指标变化无明显差别。结论IRM-2小鼠与C57BL/6小鼠Lewis肺癌模型生物学特性基本一致,IRM-2小鼠可以建立稳定的Lewis肺癌肿瘤模型应用于实验研究。     

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).     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.