Recent amplification of the kangaroo endogenous retrovirus, KERV, limited to the centromere

Mammalian retrotransposons, transposable elements that are processed through an RNA intermediate, are categorized as short interspersed elements (SINEs), long interspersed elements (LINEs), and long terminal repeat (LTR) retroelements, which include endogenous retroviruses. The ability of transposable elements to autonomously amplify led to their initial characterization as selfish or junk DNA; however, it is now known that they may acquire specific cellular functions in a genome and are implicated in host defense mechanisms as well as in genome evolution. Interactions between classes of transposable elements may exert a markedly different and potentially more significant effect on a genome than interactions between members of a single class of transposable elements. We examined the genomic structure and evolution of the kangaroo endogenous retrovirus (KERV) in the marsupial genus Macropus. The complete proviral structure of the kangaroo endogenous retrovirus, phylogenetic relationship among relative retroviruses, and expression of this virus in both Macropus rufogriseus and M. eugenii are presented for the first time. In addition, we show the relative copy number and distribution of the kangaroo endogenous retrovirus in the Macropus genus. Our data indicate that amplification of the kangaroo endogenous retrovirus occurred in a lineage-specific fashion, is restricted to the centromeres, and is not correlated with LINE depletion. Finally, analysis of KERV long terminal repeat sequences using massively parallel sequencing indicates that the recent amplification in M. rufogriseus is likely due to duplications and concerted evolution rather than a high number of independent insertion events.     

羊水直接PCR法快速诊断脊肌萎缩症的实验研究

目的：建立一种快速、简便的产前诊断脊肌萎缩症的检测方法。方法：基于运动神经元生存基因SMNc和SMNt的两个同源拷贝碱基的差异,对SMNt基因第7、8外显子进行缺失分析,抽取孕妇羊水后用作者自行研制的“HpH—Buffer”,以离心后羊水沉淀中的胎儿细胞为模板直接进行PCR扩增,扩增产物进行酶切限制性片断长度多态性分析,对2例有脊肌萎缩症患儿生育史的孕妇怀有的胎儿进行产前基因诊断。同时,为考察羊水直接扩增方法的效率,对羊水样本直接扩增和对羊水样本中提取的基因组DNA扩增进行了平行实验。结果：2例胎儿均有SMNt基因第7、8外显子缺失;以羊水为模板和以基因组DNA为模板进行扩增的效率相似。结论：应用“HpHBuffer”直接对羊水样本中SMN基因上外显子7、8进行扩增,结合限制性片断长度多态性分析SMNt上是否发生缺失,可缩短诊断时间,节约诊断成本,减少检测过程中可能出现的样本交叉污染,有望成为临床上产前诊断脊肌萎缩症的新方法。     

CMTM6, the newly identified PD-L1 regulator,correlates with PD-L1 expression in lung cancers

Modulation of Immune check point regulators, especially the PD-1/PD-L1 axis, plays a critical role in successful management of a small proportion of lung cancer patients, but not so effective in the rest of lung cancer patients. A better understanding of immunotherapy non-responsive or resistant patients therefore warranted for future development of novel therapeutics. The newly identified regulator CMTM6 (CKLF-like MARVEL transmembrane domain containing 6) has been reported to serves as the stabilizer of PD-L1 and enhances the inhibitory effect of PD-L1 on immune system in both cell line and animal models, but its clinical relevance associated with PD-L1 is unknown and the current study is designed to address this question. The study using immunohistochemistry demonstrated that CMTM6 positivity from 15 out of 19 types of cancers with our in-house tissue microarray, and PD-L1 expression is always found only in CMTM6 positive cancers. CMTM6 and PD-L1 expression were analyzed in 81 lung cancer patient sample, and we observed that CMTM6 expression correlated with cancer histotypes and inversely correlated with cancer metastases, but not with patients’ age and gender. No PD-L1 expression was observed in negative CMTM6 samples. Higher expression PD-L1 is also associated with higher CMTM6 expression. In summary, CMTM6 expression is associated with PD-L1 expression, as well as lung cancer histotypes and metastasis. The results thus for the first time confirmed earlier reports on CMTM6/PD-L1 connection, from a clinical aspect of analysis.     

脑电生物反馈训练对ADHD 儿童心理、行为的影响

目的：探讨脑电生物反馈治疗对ADHD儿童心理、行为的影响。方法：对45例ADHD儿童采用脑电生物反馈训练。20次为一个疗程。治疗前和治疗后20、40次分别用症状评定量表进行比较。结果：接受20次训练的ADHD儿童注意、情感、活动水平、异常行为、学业等方面的问题都有明显好转;接受40次训练的ADHD儿童注意、情感、活动水平、异常行为、学业等方面的问题改善十分明显。P值〈0.01差异显著。结论：脑电生物反馈训练能有效地改善儿童注意、情感、活动水平、异常行为、学业等方面的问题。     

《免疫学基础与病原生物学》移动交互式数字教材在“抗疫”时期在线教学中的应用

新型冠状病毒肺炎疫情暴发以来,全国各级各类学校延期开学,但停课不停教、停课不停学。各学校教师利用各种网络资源开展在线教学,也为深入挖掘"互联网+教育"教学新模式带来了契机。本文以《免疫学基础与病原生物学》移动交互式数字教材(云教材)应用为例,介绍如何应用移动交互式数字教材创设合理的学习情境,从而实现交互式学习,提升线上学习教学效果。     

Long noncoding RNA MEG3 plays a promoting role in the proliferation,invasion, and angiogenesis of lung adenocarcinoma cells through the AKT pathway

The role of long noncoding RNA maternally expressed gene 3 (MEG3) in lung adenocarcinoma has not been explored entirely. In this study, it was demonstrated that the expression of MEG3 was enhanced in lung adenocarcinoma tissues from TCGA database and some specific cell lines, while the survival analysis showed that patients with higher MEG3 levels had lower survival probabilities, which suggested that MEG3 might serve as a lung adenocarcinoma promoter. In addition, the results suggested that the overexpression of MEG3 could promote the proliferation and invasion of lung adenocarcinoma cells. Furthermore, increased MEG3 expression could result in a notable increase in angiogenesis-related factors as well as in the capillary tube formation of endothelial cells, which indicates that the overexpression of MEG3 could promote the angiogenesis of lung adenocarcinoma. From a mechanistic perspective, the results obtained revealed that the upregulation of MEG3 could stimulate the AKT signaling pathway and consequently lead to the biological behaviors mentioned above. In summary, all the results obtained from this study indicated that MEG3 plays a promoting role in the tumorigenesis and angiogenesis of lung adenocarcinoma, which deserves special attention when considered as a potential therapeutic target for lung adenocarcinoma.     

Expression and characterization of a chimeric bifunctional antibody with therapeutic applications

A simple method is described for the generation of a biologically produced mouse/human chimeric hetero-bifunctional antibody that has dual specificity for human carcinoembryonic Ag and metal chelate haptens. Two large compound chimeric vectors each containing the genetic information to produce a single antibody specificity were sequentially electroporated into the murine nonsecreting hybridoma SP2/0. This led to the isolation of a clone expressing high levels of total IgG (up to 25 micrograms/ml/10(6) cells), 10 to 20% of which showed simultaneous reactivity with both Ag. Binding studies showed that the immunoreactivities and affinity constants for the individual arms of the bifunctional antibody were equivalent to those seen with the parental antibodies.     

1H NMR characterization of metastable and equilibrium heme orientational heterogeneity in reconstituted and native human hemoglobin

A proton nuclear magnetic resonance study of the reaction of apohemoglobin A with both oxidized and reduced hemes reveals that at least two slowly interconverting species are initially formed, only one of which corresponds to the native proteins. Reconstitutions with isotope-labeled hemes reveal that the hyperfine-shift patterns for heme resonances in the metazido derivatives differ for the two species by interchange of heme environment characteristic of heme orientational disorder about the alpha, gamma-meso axis, as previously demonstrated for myoglobin [La Mar, G. N., Davis, N. L., Parish, D. W., & Smith, K. M. (1983) J. Mol. Biol. 168, 887-896]. Careful scrutiny of the 1H NMR spectrum of freshly prepared hemoglobin A (Hb A) reveals that characteristic resonances for the alternate heme orientation are present in both subunits, clearly demonstrating that "native" Hb A possesses an important structure heterogeneity. It is observed that this heterogeneity disappears with time for one subunit but remains unchanged in the other. This implies that a metastable disordered state in vivo involves the alpha subunit and an equilibrium disordered state both in vivo and in vitro is involved within the beta subunit. The presence of metastable disorder in fresh blood suggests an in vivo hemoglobin assembly from apoprotein and heme that is similar to the in vitro reconstitution process. The slow equilibration and known lifetimes for erythrocytes provide a rationalization for the presence of detectable metastable states. The implications of such heme disorder for Hb function are discussed.     

Determination of aflatoxin levels in peanut butter using HPLC and ELISA procedures: Inter-laboratory comparison

Mycotoxin Research - Six laboratories analyzed portions of the same aqueous acetonitrile extracts of three peanut butters for aflatoxin concentrations by an HPLC procedure (using immunoaffinity...