Comparative analysis of selenocysteine machinery and selenoproteome gene expression in mouse brain identifies neurons as key functional sites of selenium in mammals

Although dietary selenium (Se) deficiency results in phenotypes associated with selenoprotein depletion in various organs, the brain is protected from Se loss. To address the basis for the critical role of Se in brain function, we carried out comparative gene expression analyses for the complete selenoproteome and associated biosynthetic factors. Using the Allen Brain Atlas, we evaluated 159 regions of adult mouse brain and provided experimental analyses of selected selenoproteins. All 24 selenoprotein mRNAs were expressed in the mouse brain. Most strikingly, neurons in olfactory bulb, hippocampus, cerebral cortex, and cerebellar cortex were exceptionally rich in selenoprotein gene expression, in particular in GPx4, SelK, SelM, SelW, and Sep15. Over half of the selenoprotein genes were also expressed in the choroid plexus. A unique expression pattern was observed for one of the highly expressed selenoprotein genes, SelP, which we suggest to provide neurons with Se. Cluster analysis of the expression data linked certain selenoproteins and selenocysteine machinery genes and suggested functional linkages among selenoproteins, such as that between SelM and Sep15. Overall, this study suggests that the main functions of selenium in mammals are confined to certain neurons in the brain.     

55例自身血回收的临床应用探讨

总结和分析在心脏手术中进行自身血回收的经验。1999年1月－2000年3月,上海市胸科医院共进行自身血回收55例,其中男性27例,女性25例。年龄范围19－71岁,体表面积1．3－2．2m^2。本院应用的是意大利dideco公司生产的自身血回收机及其管道,不仅回收手术野血,而且回收体外循环管道内的残余血液。结果：55例患者均康复。自身血回收组患者的术后用血量和ICU时间与对照组相比,均显著降低（P＜0．05）。讨论：自身血回收技术除可减少患者术后用血量和ICU时间与对照组相比,均显著降低（P＜0．05）。讨论：自身回收技术除要减少患者术后用血、缓解血源紧张、避免血源性疾病外,还可提供以下有利条件：①为稀有血型患者提供手术保障;②可提供手术中发生意义大出血时的应急处理手段;③为外地患者就医和手术提供方便,并能减轻经济负担。     

Candidate Markers That Associate with Chemotherapy Resistance in Breast Cancer through the Study on Taxotere-Induced Damage to Tumor Microenvironment and Gene Expression Profiling of Carcinoma-Associated Fibroblasts (CAFs)

Recently, emerging evidence has suggested that carcinoma-associated fibroblasts (CAFs) could contribute to chemotherapy resistances in breast cancer treatment. The aim of this study is to compare the gene expression profiling of CAFs before and after chemotherapy and pick up candidate genes that might associate with chemotherapy resistance and could be used as predictors of treatment response. CAFs were cultured from surgically resected primary breast cancers and identified with immunohistochemistry (IHC) and Flow cytometry (FCM). MDA-MB-231 cells were cultured as the breast cancer cell line. Cell adhesion assay, invasion assay, and proliferation assay (MTT) were performed to compare the function of MDA-MB-231 cells co-cultured with CAFs and MDA-MB-231 cells without co-culture, after chemotherapy. Totally 6 pairs of CAFs were prepared for microarray analysis. Each pair of CAFs were obtained from the same patient and classified into two groups. One group was treated with Taxotere (regarded as after chemotherapy) while the other group was not processed with Taxotere (regarded as before chemotherapy). According to our study, the primary-cultured CAFs exhibited characteristic phenotype. After chemotherapy, MDA-MB-231 cells co-cultured with CAFs displayed increasing adhesion, invasiveness and proliferation abilities, compared with MDA-MB-231 cells without CAFs. Moreover, 35 differentially expressed genes (absolute fold change >2) were identified between CAFs after chemotherapy and before chemotherapy, including 17 up-regulated genes and 18 down-regulated genes. CXCL2, MMP1, IL8, RARRES1, FGF1, and CXCR7 were picked up as the candidate markers, of which the differential expression in CAFs before and after chemotherapy was confirmed. The results indicate the changes of gene expression in CAFs induced by Taxotere treatment and propose the candidate markers that possibly associate with chemotherapy resistance in breast cancer.     

银杏叶片衰老过程中光合生理特性及叶绿体超微结构的变化

选取自然条件下生长的雌雄银杏植株为实验材料,测定了银杏叶片在衰老过程中部分光合生理指标及叶绿体超微结构的变化。检测结果表明：银杏叶片在衰老过程中净光合速率、叶绿素含量均呈下降趋势,SOD、CAT、APX活性均先上升后下降,MDA含量则一直呈现上升趋势。叶片衰老过程中叶绿体类囊体膜片层逐渐松散,直至膜结构逐渐解体,叶绿体内油脂颗粒增大增多,最终解体。雌雄银杏植株在各项生理指标上差异不显著。     

miRNA-20a促进卵巢癌细胞OVCAR3的转移

目的检测miRNA．20a对卵巢癌细胞系OVCAR3转移能力的影响。方法通过实时定量RT-PCR验证反义寡核苷酸与小干扰RNA封闭与过表达的效果,然后利用MTF、软琼脂集落形成和transwell侵袭实验检测封闭和过表达miRNA．20a对OVCAR3细胞增殖及转移能力的影响。结果封闭内源性miRNA-20a后,细胞活性基本不受影响,但集落形成能力和细胞的转移能力明显降低。过表达miRNA-20a后,细胞活性基本不受影响,但集落形成能力和细胞的转移能力明显升高。结论miRNA-20a可能参与了卵巢癌细胞OVCAR3的转移。     

鹅掌楸贵州烂木山居群的微卫星遗传多样性及空间遗传结构

濒危植物鹅掌楸(Liriodendron chinense)目前仅零散分布于我国亚热带及越南北部地区, 残存居群生境片断化较为严重。研究濒危植物片断化居群的遗传多样性及小尺度空间遗传结构(spatial genetic structure)有助于了解物种的生态进化过程以及制定相关的保育策略。本研究采用13对微卫星引物, 对鹅掌楸的1个片断化居群进行了遗传多样性及空间遗传结构的研究, 旨在揭示生境片断化条件下鹅掌楸的遗传多样性及基因流状况。研究结果表明: 鹅掌楸烂木山居群内不同生境斑块及不同年龄阶段植株的遗传多样性水平差异不显著(P>0.05), 居群内存在寨内和山林2个遗传分化明显的亚居群。烂木山居群个体在200 m以内呈现显著的空间遗传结构, 而2个亚居群内的个体仅在20 m的距离范围内存在微弱或不显著的空间遗传结构。鹅掌楸的空间遗传结构强度较低(Sp = 0.0090), 且寨内亚居群的空间遗传结构强度(Sp = 0.0067)要高于山林亚居群(Sp = 0.0053)。鹅掌楸以异交为主, 种子较轻且具翅, 借助风力传播, 在一定程度上降低了空间遗传结构的强度。此外, 居群内个体密度及生境特征也对鹅掌楸的空间遗传结构产生了一定影响。该居群出现显著的杂合子缺失, 近交系数(F_IS)为0.099 (P < 0.01), 表明生境片断化的遗传效应正逐渐显现。因此, 对鹅掌楸的就地保护应注意维护与强化生境的连续性, 促进基因交流。迁地保护时, 取样距离应不小于20 m, 以涵盖足够多的遗传变异。     

影响酵母细胞麦角固醇的发酵控制参数的分析

研究了麦角固醇发酵过程中的参数。比较了溶氧、OUR、Ph和残糖浓度与酿酒酵母的生物量和麦角固醇含量的关系 ,并研究了这些参数之间的内在联系。研究表明 ,溶氧能比较准确地反映酵母的生长状况 ,是发酵过程中的一个较好的控制参数。将溶氧控制在 12 %左右能有效提高单位体积发酵液中的麦角固醇的产量。     

球形芽孢杆菌的抗药标记及外源DNA的转化与表达

用亚硝基胍（NTG）对球形芽孢杆菌（Bacillussphaericus）进行化学诱变,筛选到利福平（Rif）和链霉素（Sm）二个标记菌株。抗药浓度均达100u／ml培养基。其抗药性状能够获得较好地遗传。用含溶葡球菌酶基因的质粒DNA对RifR菌株进行原生质体转化,酶基因在该抗药菌株中获得了高效表达。经摇瓶发酵试验,溶葡球菌酶的活性约为122u／ml培养液。