Cell cycle arrest, apoptosis and p53 expression in nickel(II) acetate- treated Chinese hamster ovary cells

Nickel(II) compounds are known human and animal carcinogens. In this study, the effects of nickel(II) acetate on cell cycle, apoptosis and p53 expression were investigated in order to unveil the elements of early cellular responses to the metal. Chinese hamster ovary (CHO) cells were grown for 72 h in Ham's F-12 medium containing 0, 40, 80, 160, 240, 320, 480 or 640 microM nickel(II) acetate. DNA fragmentation, representative of apoptosis, was examined by agarose gel electrophoresis. The distribution of cells among various phases of cell cycle was determined by DNA flow cytometry. Expression of p53 protein was measured by the Western blotting technique. DNA fragmentation was detectable in cells treated with > or = 160 microM nickel(II) and its intensity increased with increasing nickel(II) concentration. The proportion of cells at S phase declined in a nickel(II) concentration- dependent manner. The decline was accompanied by an increase of cell proportion in G2/M phase and the increase became statistically significant in cells exposed to at least 480 microM nickel(II). Expression of p53 protein was not different from that in the control among samples treated with < or = 480 microM nickel(II). However, an extra fraction that migrated close to the p53 protein fraction was detected in cells treated with 640 microM nickel(II). Our findings suggest that nickel(II) modulates cellular response through effectors involved in both G2/M arrest and apoptosis regulatory pathways. The proportion of cells arrested at G2/M phase or undergoing apoptosis depends directly on nickel(II) concentration. High concentration of nickel(II) appears to up-regulate protein(s) other than the common form of p53 protein.      

红豆杉中二个新紫杉烷二萜化合物的分离与测定

从红豆杉Taxus chinensis(Pilger)Rehd。树皮中得到二个新的紫杉烷类化合物,它们的结构为1-羟基-7,9-二去乙酰基巴卡亭Ⅰ(1—hydroxy-7,9—dideacetyl—baccatin Ⅰ)和7,9-二去乙酰基巴卡亭Ⅵ(7,9-dideacetyl baccatin Ⅵ).     

Cross sectional study of use of alternative medicines in Chinese cancer patients

The aim of this study was to ascertain the prevalence of alternative medicine consumption in Chinese cancer patients on active conventional treatment. A cross sectional survey of 100 consecutive advanced cancer patients admitted to a cancer clinical trial referral unit were personally interviewed by their assigned oncology research nurse using a specially designed questionnaire. The results showed that 64% of our patients used indigenous Chinese medication. In all age groups except the over-70s (P = 0.043), > 50% took such medication, more female (76%) than male (57.6%) patients (P = 0.323). Patients of all educational levels (P = 0.062) and religious backgrounds (P = 0.08) consumed alternative medicines. Duration of alternative medication consumption was less than three months in 50% of patients, with costs between US$40 and 2000/month for 70% of patients. Reasons cited for alternative medication consumption was hope that it might be of some benefit to their well being or disease control, and maybe even result in a miracle cure. Sources of advice on medication were mostly from strangers (by word of mouth), family, friends, the media, and infrequently from qualified professional Chinese doctors. Reasons for discontinuing such treatment were mostly given as lack of positive effect. In conclusion, Chinese cancer patients, willingly, rampantly and non-selectively seek out and consume alternative medications, with almost total ignorance of the medication consumed, oblivious to any potential side effects, and with little subjective benefit.      

HPV-16 E7 protein bypasses keratinocyte growth inhibition by serum and calcium

The E6 and E7 genes of HPV-16 or HPV-18 both are necessary for effective immortalization of primary human genital keratinocytes. To analyse the individual role of E6 and E7 genes in dysregulating cell growth, we cloned the HPV-16 E6, E7 and E6/E7 genes into retroviruses. Primary human keratinocytes (PHK) were then infected with these retroviruses and selected in differentiation-inducing medium (high calcium and serum). The E6/E7 retroviruses were the most effective at inducing differentiation-resistant colonies. Intermediate numbers of colonies were induced by E6 and low numbers by E7. Interestingly, only cultures infected with E7 and E6/E7 retroviruses showed a significant proportion of cells progressing into the S phase, consistent with our earlier studies showing that E7 is required for the efficient immortalization of genital keratinocytes. Accompanying this entry into S phase, the E7 or E6/E7 transduced cells expressed high levels of cyclins A, B and E, but lower levels of cyclin D. In addition, cdc-2, cdk-2 and cdk-4 were also increased. No significant differences were detected in the expression of c-myc and c-fos between the vector and any of the transduced cells. Keratinocytes infected with the E7 retrovirus exhibited decreased levels of Rb protein and increased levels of p53, whereas cells infected with E6-expressing retroviruses displayed normal levels of Rb protein and decreased levels of p53. Finally, E7 induced a three-fold increase in bcl-2 expression. Our results indicate that the HPV-16 E7 gene alone is sufficient to bypass keratinoctye growth arrest induced by serum and calcium exposure and that the discordant expression of several cell regulatory proteins accompanies this unregulated proliferation.      

面颈部烧伤后的早期系统康复治疗

０引言面颈部是最常见的烧伤部位之一,烧伤可导致色素沉着、瘢痕增生、游离植皮挛缩．在烧伤后期,系统的康复治疗可避免或减轻后遗症,提高患者的生活质量．我们采用体位与支架治疗、压力治疗、物理治疗、运动与作业治疗、心理治疗等康复手段,对９５例面颈部烧伤患者进...     

烧成温度对可控多孔生物陶瓷制备技术的影响

目的:观察烧成温度对多孔生物陶瓷制品孔结构、显气孔率与容重、水渗透率、收缩率以及压缩强度的影响。方法:实验于2002-09/2005-09在武汉理工大学生物中心和重庆邮电大学生物实验中心完成。采用可控多孔生物陶瓷制备技术,改变烧成温度,其他因素(如成型工艺、升温速度和保温时间等)不变,分别制得不同的样品;用电子扫描显微镜观察孔道和表面形貌;根据GB/T1964～1967-1996和GB/T1969～1970-1996测量显气孔率、容重;用自制水渗透率测定仪测定水渗透率;用体积法测定收缩率。用ASTM材料强度测试机测定压缩强度。结果:①烧成温度对孔结构的影响:在900℃以内时烧成温度的变化对大孔的影响不明显,仍然在500μm左右,但当烧成温度增加到1000℃,大孔变小到400μm左右。烧成温度的变化对小孔的影响比较明显,小孔明显增大,当烧成温度800℃增加到1000℃时,小孔从10μm左右增大到20～30μm左右。烧成温度的变化对微孔的影响也比较明显,小孔明显增大,当烧成温度800℃增加到1000℃时,小孔从4μm左右增大到6μm左右。②烧成温度对显气孔率及容重的影响:随着烧成温度的提高,样品的显气孔率下降幅度增大,容重的增加幅度增大。③烧成温度对水渗透率的影响:随着烧成温度的提高,样品的水渗透率下降幅度增大,容重的增加幅度增大。④不同烧成温度对收缩率的影响:随着烧成温度的提高,样品的收缩率增大。⑤烧成温度对压缩强度的影响:随着烧成温度的提高,压缩强度增大。而在800℃以后继续升温,压缩强度急剧增大。结论:烧成温度对孔结构、显气孔率与容重、水渗透率、收缩率以及压缩强度有着重要的影响,为了保证成品有较好的孔结构、较高的显气孔率的同时具有一定的机械强度,烧成温度选择在850℃左右较佳。     

卟啉类衍生物的合成

卟啉类衍生物的合成已有七十余年的历史,其合成方法有以吡咯为原料的全合成,也有以易得的天然产物,如血红素等为原料进行半合成。自报道血卟啉衍生物(hematoporphyrin derivatives简称HpD)与激光结合用于诊治癌症以后,有关卟啉类的化学和临床研究,也迅速开展起来。1982年报道了单乙酰血卟啉、双乙酰血卟啉和乙酰氧乙基乙烯次卟啉在动物体内有对肿瘤的光敏活性,而纯血卟啉、原卟啉和羟乙基乙烯次卟啉却无效。为     

局灶性脑缺血大鼠脑内生长相关蛋白43表达与滋补肝肾中药的干预效应

目的:观察局灶性脑缺血大鼠脑内生长相关蛋白43表达与滋补肝肾中药合剂干预效果的关系。方法:实验于2004-06/2005-06在山东大学医学院药理实验室、山东中医药大学中西医结合肿瘤防治中心实验室完成。雄性Wistar大鼠49只按随机数字表法随机分为假手术组、模型组(分设1,2,3周时间点)、中药组(分设1,2,3周时间点),每组7只。模型组与中药组进行右侧近端大脑中动脉电凝术造成大鼠局灶性脑缺血模型,假手术组行同样开颅术,但不凝闭大脑中动脉,其余操作同模型组。于造模成功后第6天起中药组灌胃给予滋补肝肾中药复方,剂量为9g/(kg·d),余2组分别灌胃给予同等量生理盐水,1次/d。假手术组大鼠于术后1周时麻醉下断头处死,模型组与中药组分别于给药1,2,3周时处死,取材后用免疫组化法观察局灶性脑缺血大鼠脑内生长相关蛋白的表达。结果:纳入大鼠49只,造模不成功或死亡14只,最后每组5只共35只大鼠进入结果分析。模型组生长相关蛋白阳性信号密度值在给药1周、2周及3周组与假手术组比较差异均无显著性意义[(15.7±1.4)%,(15.3±1.3)%,(15.4±1.1)%,(15.1±1.3)%,P>0.05];中药组在治疗1周后生长相关蛋白阳性信号密度值较假手术组及模型组差异尚无显著性,但2周及3周组表达显著增强,与模型组和假手术组比较,差异有显著性意义[(23.4±1.3)%,(24.1±1.4)%,P<0.01]。结论:滋补肝肾中药复健片能增强局灶性脑缺血大鼠脑内生长相关蛋白43的表达,从而促进缺血性脑卒中后的神经功能重塑。