亚硒酸钠和硒蛋氨酸的毒性比较

目的　比较亚硒酸钠和硒蛋氨酸毒性差异以及探讨硒中毒的指标。方法　将断乳Wistar大鼠随机分为 7组 ,每组 14只 ,雌雄各半。其中一组为对照组 ,另外六组分别给予含硒 3、6、10mg kg的亚硒酸钠或硒蛋氨酸饲料 ,于第 12周将其处死。结果　当饲料硒水平达到 3mg kg时 ,动物肝脏出现病理变化 ,在Se6mg kg时 ,体重才出现下降。饲料硒水平为 6、10mg kg时 ,同一饲料硒水平的亚硒酸钠组大鼠体重小于硒蛋氨酸组。饲料硒水平为 3、6mg kg时 ,硒蛋氨酸组大鼠的肝脏病理改变轻于亚硒酸钠组 ,雄性大鼠轻于雌性。亚硒酸钠组较硒蛋氨酸组或雌性大鼠较雄性大鼠在肝脏体重比方面变化更为明显。除雌性大鼠肝脏谷胱甘肽过氧化物酶 (GPX)活性随硒水平升高而降低外 ,其它补硒各组肝、红细胞、血浆GPX活性具有随硒水平的升高而升高的趋势。结论　大鼠硒中毒的剂量为Se 3mg kg,硒蛋氨酸的毒性小于亚硒酸钠 ,雌性大鼠对硒毒性更为敏感     

Xa21转基因大米对大鼠致畸作用的实验研究

目的　观察Xa2 1转基因大米对大鼠胚胎生长、发育的影响。方法　将初断乳Wistar大鼠按雌雄分别随机分为 4组 :转基因大米组、非转基因大米组、AIN93G对照组和敌枯双阳性对照组。单笼喂养 ,饲相应鼠料 ,喂满 90天 ,雌雄合笼。观察母鼠和胎鼠的生长发育情况。结果　转基因大米组孕鼠增重、活胎体重、身长、尾长均显著高于阳性对照组 ,而死胎数、吸收胎数、畸形率 (外观、内脏、骨骼 )均显著低于阳性对照组。转基因大米组与非转基因大米组、AIN93G对照组相比 ,所有观察指标均无统计学差异。结论　转Xa2 1基因大米与非转基因大米相比 ,对大鼠受孕率、胚胎生长发育无显著性差异。     

水中微量甲胺磷农药的检验

目的选择检出水中微量甲胺磷农药的最佳方案。方法分别使用液-液萃取法、固相萃取法、活性炭富集法提取甲胺磷含量极低的液体检材，提取液经MS／GC检验。结果液-液萃取法为阴性结果，固相萃取法、活性炭富集法为阳性结果。结论实验表明对于常规液-液萃取方法效果欠佳的甲胺磷含量极低的液体检材，采取固相萃取法或活性炭富集法进行萃取，可提高检出率。     

甘草体外抑制呼吸道合胞病毒作用研究

目的:开发安全有效的抗呼吸道合胞病毒的新药.方法:采用细胞病变抑制实验观察甘草在Hela细胞中对呼吸道合胞病毒的抑制作用.结果:甘草半数中毒浓度(TC50)为3.43g/L;抑制呼吸道合胞病毒的半数有效浓度(EC50)为0.2535g/L,治疗指数(TI)为13.53;甘草对呼吸道合胞病毒的抑制作用存在量效反应关系;在感染后0 h、2 h、4 h、6 h、8 h,甘草均有抑制呼吸道合胞病毒的作用.结论:甘草在Hela细胞中对呼吸道合胞病毒有明显的抑制作用,其作用机制是多途径的.     

鹿茸口服液对抗氧化酶的影响

目的:研究鹿茸口服液对青年及老年小鼠的抗氧化作用.方法:灌服鹿茸口服液后,测定小鼠SOD、CAT和GSHpx活性及MDA含量.结果:鹿茸口服液对老年小鼠SOD活性增强和MDA含量降低作用均明显强于对青年小鼠,并能增强老年小鼠肝CAT和GSHpx活性.结论:鹿茸口服液对老年小鼠具有抗氧化作用.     

程序性凋亡分子1及其配体信号通道对调节性T淋巴细胞及肿瘤细胞的影响

程序性凋亡分子-1(PD-1)及其配体(PD-L1)是抑制性共同刺激分子中的重要成员之一,在多种肿瘤细胞及其相关细胞表面高表达,而肿瘤浸润的T淋巴细胞中调节性T淋巴细胞(Treg)的比例也异常升高.PD-L1与PD-1结合和Treg帮助肿瘤逃避免疫清除减弱了免疫应答和诱导免疫耐受.最新研究发现,PD-L1分子是诱导型Treg(iTreg)发育和功能维持的重要分子,PD-L1信号可将初始CD4+ CD25-T细胞转化成iTreg,发挥免疫抑制作用.对PD-1信号通道的研究可为抑制肿瘤免疫逃逸临床应用中肿瘤的免疫治疗提供新的理论依据和更好的治疗方法.     

Utility of BRAF protein overexpression in predicting the metastasis potential of papillary thyroid carcinoma

V-raf murine sarcoma viral oncogene homolog B1 (BRAF) is a significant member of the MAPK pathway, the point mutation (V600E) of which is a common genetic event in papillary thyroid carcinoma (PTC). Investigators showed that the variations in BRAF expression levels were independent of the V600E mutation. These variations were involved in the pathogenesis of thyroid carcinomas. This study evaluated the feasibility of BRAF, proliferating cell nuclear antigen (PCNA) and hMSH2 as markers for the prediction of the metastatic potential of PTC. Using immunohistochemistry, the expression of BRAF, PCNA and hMSH2 proteins was studied in 70 PTC and 29 nodular goiter (NG) tissues. The results indicated that i) the positive rate of BRAF, PCNA and hMSH2 expression in PTCs was significantly higher than that in NGs (P=0.000, P=0.000 and P=0.003, respectively), ii) the positive rate of BRAF expression in the lymph node metastasis (LNM) group was significantly higher than that in the non-LNM group (P=0.019), iii) the age at diagnosis of PTC patients with LNM was significantly older compared to that without LNM (P=0.021) and iv) the positive rate of BRAF expression significantly correlated with that of PCNA and hMSH2 expression (P=0.000 and P=0.019, respectively). In conclusion, BRAF, PCNA and hMSH2 overexpression appeared to be molecular events of PTC carcinogenesis. Older patients with BRAF overexpression appear to be a high-risk group for PTC metastasis. Detection of BRAF expression is likely to aid in the prediction of the metastatic potential of the carcinoma.     

Metabolomics and transcriptomics profiles reveal the dysregulation of the tricarboxylic acid cycle and related mechanisms in prostate cancer

Genetic alterations drive metabolic reprograming to meet increased biosynthetic precursor and energy demands for cancer cell proliferation and survival in unfavorable environments. A systematic study of gene‐metabolite regulatory networks and metabolic dysregulation should reveal the molecular mechanisms underlying prostate cancer (PCa) pathogenesis. Herein, we performed gas chromatography–mass spectrometry (GC–MS)‐based metabolomics and RNA‐seq analyses in prostate tumors and matched adjacent normal tissues (ANTs) to elucidate the molecular alterations and potential underlying regulatory mechanisms in PCa. Significant accumulation of metabolic intermediates and enrichment of genes in the tricarboxylic acid (TCA) cycle were observed in tumor tissues, indicating TCA cycle hyperactivation in PCa tissues. In addition, the levels of fumarate and malate were highly correlated with the Gleason score, tumor stage and expression of genes encoding related enzymes and were significantly related to the expression of genes involved in branched chain amino acid degradation. Using an integrated omics approach, we further revealed the potential anaplerotic routes from pyruvate, glutamine catabolism and branched chain amino acid (BCAA) degradation contributing to replenishing metabolites for TCA cycle. Integrated omics techniques enable the performance of network‐based analyses to gain a comprehensive and in‐depth understanding of PCa pathophysiology and may facilitate the development of new and effective therapeutic strategies.     

白藜芦醇对脂多糖诱导一氧化氦和肿瘤坏死因子生成的影响

目的：探讨白藜芦醇对脂多糖（LPS）诱导的小胶质细胞激活时所分泌的一氧化氮（NO）和肿瘤坏死因子-α（TNF-α）的影响。方法：采用LPS诱导的小胶质细胞活化模型，用ELISA法测定细胞外液中的炎症介质NO和TNF-α的含量。结果：LPS能高度激活小胶质细胞并且能使NO和TNF-α分泌增加，白藜芦醇明显抑制NO和TNF-α的含量。结论：白藜芦醇有抑制炎症介质NO和TNF-α的分泌作用。