维甲酸诱导后CK13基因在鼻咽癌中的表达研究

目的探讨维甲酸(retinoic acids,RA)对鼻咽癌细胞株HNE1生长及表型的作用,同时观察维甲酸诱导鼻咽癌细胞株HNE1后细胞角蛋白基因13(cytokeratin 13,CK13)表达情况。方法应用细胞培养的方法观察维甲酸诱导鼻咽癌细胞株HNE1细胞的生长状况,利用Northern杂交技术分析维甲酸诱导鼻咽癌细胞株HNE1后CK13基因的表达。结果维甲酸能显著抑制鼻咽癌细胞的生长,抑制的强度取决于维甲酸的浓度和诱导持续时间,当维甲酸的浓度为1×10-4 M/L时,前4天下降约50％,第5天开始细胞停止增殖,细胞数逐渐减少,细胞逐渐老化死亡。维甲酸处理后的鼻咽癌细胞从典型的多边形变成扁平、细长,类似纤维细胞的形态。维甲酸诱导后的鼻咽癌细胞中CK13基因的表达明显上调,且与维甲酸的浓度有关。结论维甲酸能促进鼻咽癌细胞的分化,可能是通过上调CK13基因的表达而实现的。     

不同高浓度CO_2对2-细胞小鼠胚胎体外发育的影响

目的 :观察不同高浓度二氧化碳 ( CO2 )对 2 -细胞小鼠胚胎体外发育的影响。方法 :获取小鼠 2 -细胞胚胎 ,置于 CZB培养液微滴 ,覆盖经三蒸水处理的石蜡油 ,分别在 5 % CO2 (对照组 )、5 .7%CO2 、6.0 % CO2 和 1 5 % CO2 浓度下体外培养 ;在 1 5 % CO2 时 ,另设覆盖经磷酸盐缓冲液 ( PBS)处理的石蜡油或不覆盖石蜡油的实验组 ,观察胚胎发育情况。结果 :5个实验组的囊胚率均显著低于对照组 ( P<0 .0 1 ) ,5 .7% CO2 时仅为 4.3% ,其余 4组的均为 0。 CO2 浓度 5 .7%和 6.0 %时 ,胚胎大部分停滞在 2 -细胞和 4-细胞期 ,两者间无统计学差异 ( P>0 .0 5 )。CO2 浓度 1 5 %时 ,覆盖经三蒸水处理的石蜡油组 ,有 1 5 %的胚胎发育到 4-细胞阶段 ,但 4-细胞胚胎的卵裂球不规则 ,很快退化 ;覆盖经 PBS处理过的石蜡油组 ,有 2 .2 %的胚胎发育到 4-细胞 ,其余出现严重的退化。结论 :高浓度 CO2 对小鼠胚胎发育有强毒性效应 ,引致胚胎发育停滞和严重降解 ;高浓度 CO2 时 ,胚胎覆盖三蒸水处理石蜡油的效果优于经 PBS处理的石蜡油 ;严密监控 CO2 浓度对胚胎体外发育是重要的     

重组人甲状旁腺激素1-34的氨基酸组成分析

分析重组人甲状旁腺激素 1-3 4的氨基酸组成 ,为该品种的结构鉴定提供依据。水解条件含 1%苯酚的6mol L盐酸 ,10 5℃水解 2 4h ;衍生方法异硫氰酸苯酯 (PITC)柱前衍生法 ;氨基酸测定色谱条件色谱柱为PhenomenexprodigyODS 10 0A。 (4 .6mm× 2 5cm ,5 μm) ;流动相A为 0 .1mol L醋酸钠 (pH6.5 ) -乙腈 (93 :7) ,B为水 -乙腈 (1:4) ;二元梯度洗脱 ;检测波长为 2 5 4nm ;流速为 1ml min ;柱温为 40℃。结果 :实验值与理论值一致 ,偏差小于 10 %。本法准确、可靠、重现性好 ,可用于该产品的质量控制。     

白藜芦醇和抗坏血酸对预防非典型肺炎方剂Ⅰ和Ⅵ所致小鼠外周血液淋巴细胞DNA损伤的保护作用

目的研究白藜芦醇和抗坏血酸对预防非典型肺炎方剂Ⅰ和Ⅵ致小鼠外周血液淋巴细胞DNA损伤的保护作用.方法采用单细胞凝胶电泳方法研究白藜芦醇和抗坏血酸对预防非典型肺炎方剂Ⅰ和Ⅵ致小鼠外周血液淋巴细胞DNA损伤的保护作用.结果白藜芦醇(50,100,200 mg/kg×3 d)和抗坏血酸(50,100,200 mg/kg×3 d)对方剂Ⅰ和Ⅵ(临床等效量×3 d)所致的小鼠外周血液淋巴细胞DNA损伤呈剂量依赖性的保护作用(P＜0.05).结论白藜芦醇和抗坏血酸能够保护预防非典型肺炎方剂J和Ⅵ对小鼠外周血液淋巴细胞DNA的损伤.     

Radical trapping in glycogen storage disease 1a

Oxidative mechanisms involving lipid peroxidation in the subendothelium of the arterial vessel wall play a key role in atherogenesis. Despite severe hyperlipidaemia, patients with glycogen storage disease type la (GSD1a) do not develop premature atherosclerosis. Therefore, we analysed parameters of antioxidative defence and oxidative stress in plasma and serum of patients with GSD1a (n=17) and compared them with those of patients with type 1 diabetes mellitus (n=17), familial hypercholesterolaemia (n=18) and healthy controls (n=20). We measured the total radical trapping ability parameter (TRAP), single plasma antioxidants (sulfhydryl-groups, uric acid, vitamin C, alpha-tocopherol, coenzyme-Q10), markers of lipid peroxidation, lipoprotein (a) and homocysteine. Patients with GSD1a showed an elevated TRAP (P<0.01) compared to the three other groups. This can mainly be attributed to elevated uric acid levels (P<0.05 versus control). Lipoprotein (a) was significantly lower in the GSD1a group compared to the three other groups (P<0.05).Conclusion: Patients with glycogen storage disease type 1a show an increased antioxidative defence in plasma which may protect them against lipid peroxidation and thus against premature atherosclerosis. Our finding of low lipoprotein (a) levels in this small group of patients warrants further investigation in a greater number of patients before assessing its role in atherogenesis in glycogen storage disease type 1a. Published online: 19 September 2002     

Anaphylactic shock secondary to intravenous administration of folinic acid: a first report.

BACKGROUND: Folates, components of the B-complex vitamins, have numerous pharmacological effects. In oncology combining folates with 5-fluorouracil (5-FU) enhances the cytotoxic effects of chemotherapy in colon cancer patients. Folic acid has been rarely involved in adverse allergic reactions. To the best of our knowledge no anaphylactic reaction secondary to folinic acid (FA) administration has ever been reported before. PATIENTS AND METHODS: An 80-year-old patient had adjuvant chemotherapy for colon cancer including FA and 5-FU and irinotecan as a second line agent after multiple metastases. RESULTS: Following FA administration anaphylactic shock occurred. Diagnosis was made according to the French method of adverse reactions monitoring. CONCLUSION: Anaphylactic shock may be an adverse reaction of FA in patients receiving chemotherapy for colon cancer.     

p16(ink4a) and retinoic acid modulate rhoA and GFAP expression during induction of a stellate phenotype in U343 MG-A astrocytoma cells

We previously showed that the expression of p16(ink4a) (p16), in conjunction with retinoic acid (RA) treatment in the p16-deficient astrocytoma cell line, U343 MG-A, induced a potent cell cycle arrest in G(1) associated with changes in morphology. In this study, we investigated the effects of p16 expression and RA treatment on the expression and distribution of actin, glial fibrillary acidic protein (GFAP), and vimentin within the U343 MG-A astrocytoma cytoskeleton. Changes in expression and location of the small GTPase, rhoA, were also examined after p16 expression and RA treatment. We showed that p16 expression and RA treatment led to an increase in the expression of GFAP, as well as its reorganization but that it did not significantly affect actin or vimentin expression. p16 induction in combination with RA treatment resulted in a decreased expression and activation of rhoA as determined by immunocytochemistry and Western blot analysis of soluble and insoluble fractions of cell lysates. Endogenous levels of rhoA expression varied among samples in a panel of astrocytoma cell lines as determined by Western blot analysis. Introduction of a dominant active rhoA mutant into p16-induced, RA-treated U343 MG-A astrocytoma cells was associated with the loss of long astrocytic processes and stellate morphology. These data are among the first to report the pattern of rhoA expression in human astrocytoma cell lines. They furthermore suggest that the stellate cell phenotype observed in U343 MG-A astrocytoma cells after cyclin-dependent kinase inhibitor (CKI) induction and RA treatment is accompanied by an inhibition and inactivation of rhoA in this cell system.     

Electrochemical aspects of cations in the cochlear hair cell of the chinchilla: a cellular model of the ion movement

Summary The dc potential and ion composition (K⁺, Na⁺, and Ca⁺⁺) in the hair cells of the cochlea were examined using ion-selective microelectrodes. The K⁺, Na⁺, and Ca⁺⁺ concentrations were 124.0 ± 29.8 mM, 6.9 ± 4.1 mM, and 1.7 ± 1.4 M in the hair cells, respectively. The electrochemical potential gradients for K⁺, Na⁺, and Ca⁺⁺ across the apical membranes of the hair cells were calculated to be 160.0 ± 29.8 mV, 87.6 ± 27.0 mV, and 194.4 ± 35.2 mV, respectively. Those for K⁺, Na⁺, and Ca⁺⁺ across the basolateral membranes of the hair cells were –12.6 ± 33.3 mV, 126.8 ± 28.3 mV, and 170.8 ± 30.1 mV, respectively. These findings were discussed in light of the transport mechanism necessary to maintain the ionic composition of hair cells.     

玻璃毛细柱色谱法对脂肪酸的分析

通过色谱条件、斜率灵敏度、尾吹气流等的选择,我们建立了一个分析脂肪酸的气相色谱法。脂肪酸甲基化后,在涂交联甲基硅油的毛细柱内的保留时间和碳原子数目密切相关。如以相对保留时间为纵坐标,碳原子数为横坐标,可得一条光滑曲线。方法重现性好,相对标准偏差0.4-1.5％。用以分析六种植物油的脂肪酸组成,结果接近加拿大谷物协会的报告。用于细菌游离脂A的分析,结果与薄层层析和化学分析相一致。