采用MDA-MB-231细胞膜进行表皮生长因子受体活性的检测

目的　探讨能否直接利用肿瘤细胞膜进行表皮生长因子受体 (Epidermalgrowthfactorreceptor,EGFR)催化活性检测。方法　首先筛选出EGFR基因表达水平相对较高的细胞株MDA MB 2 31,通过差速离心制备细胞膜 ,采用Westernblotting检测EGFR催化磷酸化的程度。结果　底物被磷酸化 ,加入特异性拮抗剂AG14 78后 ,磷酸化被抑制。结论　利用肿瘤细胞膜检测EGFR活性的设想是成立的 ,并且其方法简便、经济。     

Dibenzocyclooctadiene Lignans from Roots and Stems of Kadsura coccinea

Ten dibenzocyclooctadiene lignans were obtained from the ethereal soluble fraction of the dried roots and stems of KADSURA COCCINEA. Two of them were new compounds, named kadsutherin ( 8) and isokadsuranin ( 10). Their structures were elucidated on the basis of chemical and spectral analysis.     

Radioprotective Effect of Whey Hydrolysate Peptides against γ-Radiation-Induced Oxidative Stress in BALB/c Mice

Radiation therapy is widely used in the treatment of tumor diseases, but it can also cause serious damage to the body, so it is necessary to find effective nutritional supplements. The main purpose of this study is to evaluate the protective effect of whey hydrolysate peptides (WHPs) against ⁶⁰Coγ radiation damage in mice and explore the mechanism. BALB/c mice were given WHPs by oral gavage administration for 14 days. Then, some mice underwent a 30-day survival test after 8 Gy radiation, and other mice received 3.5 Gy radiation to analyze the changes in body weight, hematology and bone marrow DNA after three and 14 days. In addition, through further analysis of the level of oxidative stress and intestinal barrier function, the possible mechanism of the radioprotective effect of WHPs was explored. The study found WHPs can prolong survival time, restore body weight, and increase the number of peripheral blood white blood cells and bone marrow DNA content in irradiated mice. In addition, WHPs can significantly improve the antioxidant capacity, inhibit pro-inflammatory cytokines and protect the intestinal barrier. These results indicate that WHPs have a certain radioprotective effect in mice, and the main mechanism is related to reducing oxidative damage.     

科技论文中通信作者和末位作者重要性的比较

【目的】 试图解决论文作者署名中通信作者与末位作者谁是最重要的作者的问题。【方法】 以Science期刊为研究对象,收集该刊论文的作者署名信息和作者贡献声明信息,提取贡献要素并进行规范化分类,结合作者贡献声明和作者署名位置、署名角色进行比较分析。【结果】 在论文作者署名位置的分布中,末位作者通常同时是通信作者。在论文研究中,通信作者往往比末位作者发挥更重要的作用。对于不是通信作者的末位作者,其对研究的贡献往往较低。【结论】 结合作者贡献声明能够合理地判断作者的重要性。学术界对于作者署名位置应该有更加统一的认识,建议在科技期刊中推行作者贡献声明政策,完善学术期刊作者贡献声明规范。     

维生素D缺乏性晚发性佝偻病的骨密度研究

目的：探讨维生素D缺乏性晚发性佝偻病的骨密度变化;方法：采用病例对照研究方法。对640名学生进行问诊及体验,测定非优势侧尺挠骨中1／3交界处骨密度（BMD）,病例组检测骨碱性磷酸酶,拍摄腕部X光片,病例组与对照组同测血250HD3;结果：病例组骨密度显著低于对照组,病例组250HD3异常者显著低于对照组;结论：晚佝病是由于维生素D缺乏所至的骨量减少性疾病,日后影响峰值骨量的形成,并与成人期骨质疏松有密切的关系,骨密度检查对晚佝病有重要诊断价值。     

无呼吸道症状肺癌35例临床分析

目的：探讨完全无症状或无呼吸道症状肺癌的早期诊断。方法：随机抽取1995年2月至2001年3月经临床及病理诊断为肺癌的380例,其中“无症状”肺癌35例进行分析。结果：由于“无症状”肺癌的异位内分泌等作用,致使患者表现为神经科,骨科,皮肤科,消化科,内分泌科学等多学科病变。结论：为了提高“无症状”肺癌的早期确诊率,及早行胸片,CT片,支行镜等相关检查相当重要,定期体检对于早期发现肺癌有重要的意义。     

慢性乙型肝炎患者肝组织FasL表达与血清可溶性FasL水平的关系

目的：探讨慢性乙型肝炎患者肝组织中FasL表达与血清可溶性FasL水平的关系。方法：用免疫组化方法检测60例慢性乙型肝炎患者肝穿组织FasL的表达,同时用酶联免疫吸附试验检测血清可溶性FasL。结果：重度慢性乙型肝炎患者血清中sFasL水平＞中度＞轻度,各组间差异有显著意义（P＜0．01）;慢性乙型肝炎患者肝组织FasL表达的程度和血清sFasL水平与肝组织病变的活动性一致。结论：（1）肝组织炎症程度加重,肝组织FasL抗原的表达增强,同时血清中sFasL水平升高;（2）Fas介导的肝细胞凋亡在慢性乙型肝炎的发病机制中起重要作用,抑制肝细胞Fas表达有助于减轻肝细胞损伤程度。     

端粒酶及nm23的表达与胃腺癌预后的关系探讨

目的 :探讨端粒酶和nm2 3癌基因蛋白表达与胃癌根治术后复发及预后的关系。方法 :采用端粒酶原位分子杂交技术及免疫组化S P法分别对 4 5例原发性胃腺癌组织中端粒酶的活性及nm2 3进行检测 ,并结合内镜及随访资料进行分析。结果 :胃腺癌端粒酶阳性表达率及nm2 3低表达率在有淋巴结转移组显著高于无淋巴结转移组 ;在术后 5年内复发者中显著高于无复发者。虽然随着胃腺癌分化程度的降低及浸润深度的增加 ,端粒酶活性及nm2 3低表达呈增强趋势 ,但其差异无统计学意义。结论 :胃腺癌组织中端粒酶的活性表达及nm2 3的低表达与淋巴结转移及术后复发显著相关 ,两者的表达变化对判断胃癌术后复发及预后判断有重要临床意义     

Culture bovine prospermatogonia with 2i medium

Germplasm cryopreservation and expansion of gonocytes/prospermatogonia or spermatogonial stem cells (SSCs) are important; however, it's difficult in cattle. Since inhibitors of Mek1/2 and Gsk3β (2i) can enhance pluripotency maintenance, effects of 2i-based medium on the cultivation of bovine prospermatogonia from the cryopreserved tissues were examined. The testicular tissues of newborn bulls were well cryopreserved. High mRNA levels of prospermatogonium/SSC markers (PLZF, GFRα-1) and pluripotency markers (Oct4/Pouf5, Sox2, Nanog) were detected and the PLZF⁺/GFRα-1⁺ prospermatogonia were consistently identified immunohistochemically in the seminiferous cords. Using differential plating and Percoll-based centrifugation, 41.59% prospermatogonia were enriched and they proliferated robustly in 2i medium. The 2i medium boosted mRNA abundances of Pouf5, Sox2, Nanog, GFRα-1, PLZF, anti-apoptosis gene Bcl2, LIF receptor gene LIFR and enhanced PLZF protein expression, but suppressed mRNA expressions of spermatogonial differentiation marker c-kit and pro-apoptotic gene Bax, in the cultured prospermatogonia. It also alleviated H₂O₂-induced apoptosis of the enriched cells and decreased histone H3 lysine (K9) trimethylation (H3K9me3) and its methylase Suv39h1/2 mRNA level in the cultured seminiferous cords. Overall, 2i medium improves the cultivation of bovine prospermatogonia isolated from the cryopreserved testes, by inhibiting Suv39h1/2-mediated H3K9me3 through Mek1/2 and Gsk3β signalling, evidencing successful cryopreservation and expansion of bovine germplasm.