蔬菜中联苯菊酯和甲氰菊酯的气相色谱测定方法

目的:探索乙腈和甲苯在不同体积比的混合洗脱液及其洗脱液用量对蔬菜中联苯菊酯和甲氰菊酯在PestiCarb/NH2固相萃取柱(SPE柱)上的洗脱效率,以气相色谱ECD测定。方法:试样用乙腈提取,浓缩后经PestiCarb/NH2SPE柱、乙腈∶甲苯=3∶1混合洗脱液净化,用气相色谱ECD,以OV-1701毛细管柱分离测定。结果:联苯菊酯的最低检出浓度为0.3μg/kg,最低检测定量浓度为0.8μg/kg,相对标准偏差(RSD)为6.1%～3.8%;甲氰菊酯的最低检出浓度为1.0μg/kg,最低检测定量浓度为3.3μg/kg,相对标准偏差(RSD)为6.4%～3.4%。平均回收率均为95%～105%。结论:在该净化条件下,试样经气相色谱ECD测定,联苯菊酯和甲氰菊酯有较好回收率和理想的重复性,适用于该类样品的测定。     

真元气功治疗耳聋的微循环观察

本文报导对接受真元气功治疗的26例聋人一次治疗前后微循环及穴位血流图观察结果。患者全部经广州中山医附院耳科电反应测试诊为感觉神经性耳聋,4人为突发性,22人均有应用耳毒性药物史,全部为中重度聋,24人于婴幼儿时起病成为聋哑人。年龄2岁至50岁,平均年龄10.5岁。男14例,女12人。接受治疗均在1个疗     

32P-磷酸铬-聚 L-乳酸缓释粒子的制备及其放射性释出和生物分布

Objective The aim of this study was to prepare the 32P-chromic phosphate-poly(L-lac-tide) (32P-CP-PLLA) particles with different ratio of the materials and further examine their performance in-dex in vivo and in vitro and their intracorporeal distribution. Methods The erosion, degrading rates, de-layed release velocity and radioactivity self-absorption coefficient (RSAC) of 32P-CP-PLLA particles made from different materials were investigated and compared. After the implantation of 32P-CP-PLLA particles and the injection of 32P-CP colloids in the muscular tissues, the weight loss rate and the radioactivity release rate (RRR) of the particles were calculated. The intracorporeal distribution, radioactive half-life and bio-logical effect of 32P in the targeting sites were further studied. Statistical analysis was performed with SPSS 12.0, and one-way analysis of variance and t-test were used. Results 32P-CP-PLLA particles were of green cylinder, with regular shape and radionuclide distribution. The RSAC of the particles was of little re-lation with molecular weight of PLLA and proportional to the ratio of PLLA to CP. The extracorporeal release rate increased with the reduction of molecular weight of PLLA and with the increase of the ratio of PLLA to CP. The RRR reached peak when PLLA was 3 times of CP. The 32P-CP, released with the degradation and corrosion of the particle distributed mainly in the surrounding muscles of the particle. And the peak of per-centage activity of injection dose per gram of tissue (% ID/g) in liver, spleen and bone were 1. 7887, 1. 6401 and 1. 9470 respectively, much lower than that in the 32P-CP group (4.7523, 3.9712 and 4.3174 ; all t > 2.7, all P < 0.05). The % ID/g in other organs was much less. The radioactivity effective half-life in the targeting sites increased to about 13 d. There was widespread necrosis around the particles with no ex-istence of normal tissues among them. And no abnormality in spleen and liver was found. Conclusion As a better dosage form of pure β-particle emitter, 32P-CP-PLLA, which can increase the targeting radioactive dosage and effective half-life in the implanting sites, can be served as an potential implanting agent for onco-therapy with a better perspective.     

消化道肿瘤nm23基因研究进展

对于恶性肿瘤的侵袭和转移这一复杂过程的基因调节机制、基因诊断和基因治疗策略,目前已成为癌细胞研究领域的关键问题,1988年由Ｓｔｅｅｇ等[1]首先发现的ｎｍ23基因,被认为是一种重要的抑癌基因[1～21],故倍受人们的关注和重视。人们对肺癌、乳腺癌、肾癌等作了许多研究和报道,但对消化道肿瘤的研究尚不深入,为提高对ｎｍ23基因及其在消化道肿瘤中作用的认识,笔者拟就消化道肿瘤ｎｍ23基因的研究进展作一综述。1　ｎｍ23基因基础研究Ｓｔｅｅｇ等[1]用消减杂交分离方法从不同转移潜能的鼠黑色素瘤Ｋ-1735细胞株中克隆到一种抑制肿瘤转移的…     

脂肪酸合酶抑制剂阻遏人结肠癌细胞增殖的实验研究

目的：探讨脂肪酸合酶抑制剂对人结肠癌细胞增殖的影响。方法：应用细胞形态学，ＭＴＴ法及成集落实验方法进行检测和观察。结果：癌细胞在脂肪酸合酶抑制剂浅蓝菌素作用下，细胞增殖被阻遏，并呈现剂量－效应关系。同时发现癌细胞呈现细胞凋亡的形态学改变。凋亡的表现为细胞固缩，核染色质凝聚，边集或断裂。     

火焰原子吸收光谱法测定饮料中镁含量的测量不确定度评定

目的评定火焰原子吸收光谱法测定饮料中镁含量的测量不确定度。方法根据测定方法建立数学模型,分析测量不确定度来源,计算各不确定度分量和扩展不确定度。结果当k=2（95%置信概率）时,饮料中镁的含量为（4.45±0.68）mg/L。结论测量不确定度的主要来源为样品定容体积引入的不确定度和曲线拟合引入的不确定度以及重复测定时产生的不确定度。     

FHIT基因过表达对人胃癌细胞系MKN-45增殖和粘附的影响

目的探讨FHIT基因过表达对人胃癌细胞系MKN-45增殖和粘附能力的影响。方法将载有人外源性FHIT基因的真核表达质粒pcDNA3.1-FHIT转染FHIT基因mRNA阴性表达人胃癌细胞系MKN-45,分别用MTT法、平板克隆形成实验、黏附实验检测转染前后细胞增殖活性、克隆形成能力及粘附能力的变化。结果FHIT基因的过表达可降低MKN-45细胞的增殖和克隆形成能力(P<0.05),但是对MKN-45细胞与内皮细胞的粘附能力无明显影响。结论FHIT基因过表达可抑制人胃癌细胞系MKN-45的增殖和克隆形成,对于MKN-45细胞与内皮细胞的粘附能力无明显影响。     

Reg Ⅳ基因对5-FU干预结直肠癌LoVo细胞增殖、凋亡的影响

目的 观察Reg Ⅳ基因对5-FU干预结直肠癌LoVo细胞增殖、凋亡的影响.方法 构建重组质粒pcDNA3.1-RegⅣ并转染LoVo细胞,RT-PCR和细胞免疫组化检测转染前后细胞中Reg Ⅳ基因的mRNA和蛋白表达.终浓度80 μmol/L的5-FU干预细胞48 h后,MTT检测细胞的增殖活性.平板克隆实验观察细胞的克隆形成能力.FCM检测细胞凋亡.结果 LoVo细胞不表达Reg Ⅳ基因,转染后的LoVo/RegⅣ细胞高表达RegⅣ.5-FU干预后,未转染组(LoVo)和空转质粒组(LoVo/空载)细胞增殖活性、克隆形成能力较RegⅣ转染组(LoVo/RegⅣ)明显降低(P<0.05),细胞凋亡率较RegⅣ转染组明显升高(P<0.05).结论 RegⅣ基因表达可能降低5-FU抑制LoVo细胞的增殖活性及克隆形成能力,并能抑制5-FU诱导LoVo细胞凋亡的作用.Reg Ⅳ基因可能是患者对5-FU化疗产生抗药性的标志及导致临床化疗失败的原因之一.     

TNF-α对小鼠肾上腺皮质细胞系Y1皮质醇合成的影响

目的 探讨肿瘤坏死因子α(TNF-α)对小鼠肾上腺皮质细胞系Y1皮质醇合成及其合成过程中的关键基因StAR的变化.方法 50U/ml的TNF-α或(和)10-9mol/L促肾上腺皮质激素(ACTH)在不同作用时间处理小鼠肾上腺皮质细胞系Y1.台盼蓝拒染法检测细胞数目,放免法检测细胞皮质醇合成水平,RT-PCR检测类固醇急性调节蛋白相关基因(StAR)的表达变化.结果 50U/ml TNF-α或(和)10-9mol/L ACTH处理Y1细胞不同时间,发现TNF-α和ACTH共同作用后,皮质醇合成水平明显下降(P＜0.05),StAR mRNA表达明显下降(P＜0.05);而TNF-α单独作用时对皮质醇合成的抑制作用不明显,StAR mRNA表达也无明显改变(P＞0.05);ACTH单独作用时Y1细胞皮质醇的合成明显升高(P＜0.05);StAR mRNA表达明显升高(P＜0.05).结论 TNF-α与ACTH共同作用通过抑制StAR表达进而抑制皮质醇合成能力;而TNF-α单独作用无明显抑制作用,ACTH单独作用后其表达量则明显升高.     

肿瘤手术切缘的分子边界研究进展

目前,手术切除是治疗肿瘤的最主要手段之一,而术后局部复发是手术治疗失败和影响患者预后的重要原因。因此,手术切缘彻底与否成为影响肿瘤预后的主要因素,如何获得安全的手术切缘目前仍存在较大争议。传统方法判断手术切除是否干净主要基于对切缘组织的常规病理学(即细胞形态学