As2O3治疗急性早幼粒细胞白血病的作用机制

目的：研究三氧化二砷（As2O3）治疗M3型急性早幼粒细胞白血病（APL）的作用机制。方法：将培养的NB4细胞加入不同浓度（0．5μM,1μM,1．5μM,2μM,3μM）的As203作用48h后,采用MTT比色法观察不同浓度As2O3对NB4细胞活力的影响,用流式细胞术及Caspase-3活性检测试剂盒检测As2O3引起NB4细胞凋亡情况,用westernBlot检测As203对Caspase-3蛋白的作用。结果：MTT比色法结果显示,As2O3明显抑制NB4细胞增殖,且呈浓度依赖性,2μMAs2O3孵育48hNB4细胞活力下降约50％;流式细胞术结果显示,2μMAs2O3作用48h后,NB4细胞凋亡率显著增加,且以早期凋亡率增加为主（P〈0．01）;同时As2O3处理后的NB4细胞Caspase-3活性明显增加,为对照组的2．2倍（P〈0.01）;WesternBlot结果显示,As2O3显著增加Caspase-3总蛋白及其激活型cleaved—Caspase-3（p17）蛋白表达量。结论：As2O3可诱导NB4细胞凋亡,此作用与激活依赖Caspase-3的细胞凋亡通路相关,但是具体是通过何种凋亡通路,以及参与其中的信号分子需要进一步验证。     

三氧化二砷对白血病细胞DNA损伤及凋亡相关基因表达的影响

目的：研究三氧化二砷（As2O3)对HL－60，K562和NB4细胞DNA的损伤及凋亡相关基因的调控。方法：用荧光显微技术，单细胞彗星电泳观察As2O3对HL－60，K562及NB4细胞DNA的损伤，用流式细胞术测定As2O3对HL－60，K562及NB4细胞凋亡相关基因Bcl-2和p53的表达，结果：As2O3诱导HL－60，K562和NB4细胞的凋亡时造成了DNA损伤；显著下调三种细胞内Bcl-2蛋白的表达，且Bcl-2下调程度与凋亡有密切关系，上调了p53蛋白的表达。结论：As2O3诱导细胞凋亡时发生了DNA的损伤，诱导凋亡主要是通过下调Bcl-2和上调p53来实现。     

三氧化二砷对白血病细胞凋亡和分化的双向诱导作用

目的:研究三氧化二砷(As2O3)对白血病细胞株NB4,HL-60细胞凋亡和分化的双向诱导作用。方法:细胞分化抗原用相应抗体标记,用PI标记DNA,并用流式细胞仪检测。结果:0.6μmol·L-1As2O3作用72h能诱导NB4发生44.9%的凋亡,提高其浓度至8.1μmol·L-1,也能诱导HL-60发生62.3%凋亡,低浓度0.1～0.3μmol·L-1As2O3对NB4、0.1～2.7μmol·L-1As2O3对HL-60细胞无诱导分化作用,对分化抗原表达无影响。只有当浓度增至0.6和8.1μmol·L-1并作用较长时间才能使两种细胞分化抗原表达增加。结论:低浓度As2O3无促分化作用,较高浓度作用较长时间才显示诱导凋亡和一定的促分化作用。     

三氧化二砷诱导急性早幼粒白血病细胞凋亡的机制

目的 探讨线粒体在三氧化二砷(As2O3)诱导急性早幼粒细胞白血病NB4细胞凋亡中的作用并观察线粒体基因组在该过程中的表达变化.方法 采用荧光显微镜、流式细胞仪、细胞生长抑制实验、线粒体膜电位检测、RT-PCR等方法,观察As2O3对NB4细胞的诱导凋亡、生长抑制作用及线粒体基因差异表达变化.结果 荧光显微镜观察显示,NB4细胞经As2O3处理48h后呈现出明显的凋亡形态学改变.As2O3在一定的浓度范围内对NB4细胞具有显著的生长抑制效应.流式细胞仪分析发现,NB4细胞经0.5、1、2、3μmol/L As2O3处理后,其细胞凋亡率分别为5.02%、6.40%、28.40%、33.34%.以0.5、1、2、4、8μmol/LAs2O3分别处理NB4细胞48h后,流式细胞仪检测NB4细胞线粒体膜电位分别下降12.8%、21.6%、66.9%、83.7%、83.8%.对As2O3诱导NB4细胞凋亡过程中的13个线粒体基因组基因进行RT-PCR分析发现,COX2基因表达下调,其余12个基因表达无明显改变.结论 As2O3在体外对NB4细胞具有显著的诱导凋亡及生长抑制效应,其诱导凋亡作用与线粒体膜电位下降密切相关;线粒体相关基因COX2的表达变化参与了As2O3诱导的NB4细胞凋亡过程.     

三氧化二砷诱导血管内皮细胞凋亡和抑制血管生成的研究

目的：研究三氧化二砷(As2O3)抑制血管内皮细胞(HUVECs)生长、诱导凋亡和抑制血管生成的作用。方法：As2O3与HUVECs共同孵育一定时间后，观察细胞形态学变化，并用MTT方法测定细胞生长曲线图、TUNEL方法检测细胞凋亡；观测As2O3对鸡胚血管生成的影响。结果：在0．75μmol／L～6μmol／L浓度范围内随药物浓度增加或作用时间延长，细胞生长抑制和细胞凋亡效果越显著；As2O3作用鸡胚绒毛尿囊膜后血管生成减少。结论：As2O3抑制HUVECs生长、诱导细胞凋亡，对血管生成有抑制作用。     

三氧化二砷诱导NB4细胞凋亡相关基因表达改变的基因芯片研究

目的 利用基因芯片技术研究NB4细胞经三氧化二砷(As2O3)诱导凋亡后的凋亡相关基因表达变化.方法 检索NCBI的Entrez以及Human IPI数据库,通过染色体定位来排除冗余基因,共获得1 384个凋亡相关基因.探针使用软件OligoArray 2.0设计,并作Blast比对.设计基因特异寡核苷酸探针,合成后点样,制备寡核苷酸芯片.用2μmol/L的As2O3处理NB4细胞48h后,提取细胞总RNA,分别以Cy3,Cy5标记对照组及实验组,随后与含1 384个凋亡相关基因的寡核苷酸芯片杂交,使用基因芯片扫描仪对杂交信号扫描,软件分析Cy3和Cy5两种荧光信号的强度和比值,找出经As2O3处理后出现差异表达的基因,并挑选其中差异表达最明显的4条基因,设计引物后与CNDA产物进行PCR扩增,琼脂糖凝胶电泳进行验证.结果 NB4细胞经2μmol/L As2O3作用48h后共有4个基因表达上调,12个基因表达下调,且RT-PCR验证结果与基因芯片结果完全相符.结论 As2O3可以诱导NB4细胞一系列基因表达的改变,这些涉及信号转导、转录调节、细胞周期、氧化应激、蛋白质的翻译合成及细胞分化等方面基因的差异表达,可能在NB4细胞凋亡中起着重要作用.     

三氧化二砷对人结肠癌细胞增殖及凋亡影响的研究

目的：观察三氧化二砷（As2O3）对人结肠腺癌LS-174T细胞增殖的抑制及凋亡的诱导作用。方法：应用MTT法、细胞集落形成试验、流式细胞仪技术和TUNEL法观察不同浓度的As2O3(1.0μmol,2.0μmol，4.0μmol，8.0μmol，16.0μmol/L）对LS-174T细胞增殖和凋亡的影响。免疫组化技术观察As2O3对bcl-2基因表达的影响。结果：LS-174T细胞经As2o3作用后，细胞生长抑制率上升，细胞集落形成率下降，细胞周期中G1期细胞比例上升，S期和G2/M期细胞比例下降，TUNEL法显示凋亡细胞数增加，免疫组化结果显示bcl-2的表达明显减弱。结论：As2O3能抑LS-174T细胞增殖并诱导该细胞株凋亡，其机理可能与下调bcl-2表达有关。     

三氧化二砷对鼻咽癌离体细胞的放射增敏作用

目的探讨三氧化二砷(As2O3)对鼻咽癌离体肿瘤细胞的放射增敏作用及其机理。方法利用多靶单击数学模型拟合放射剂量一细胞存活曲线，观察As2O3对鼻咽癌细胞株CNE-1的放射增敏作用。流式细胞法观察As2O3对细胞周期分布的影响，末端脱氧核苷酰转移酶法(TUNEL法)检测细胞凋亡，免疫组织化学观察As2O3对p53，bcl-2基因表达的影响。结果As2O3对鼻咽癌细胞株CME-1有明显的放射增敏效应，1．0，1．5μmol／L的As2O3作用48h的放射增敏比分别为1．33和1．57。药物作用后G2／M期细胞比例逐渐增加，S期细胞比例逐渐减少；细胞凋亡指数增加，p53基因表达，bax／bcl-2基因表达上调。结论As2O3对鼻咽癌细胞株CNE-1有明显的放射增敏效应，放射增敏的机理可能与As2O3使细胞周期阻滞在G2／M并使S期细胞减少，以及细胞p53、bax、bcl-2基因表达变化导致凋亡增加有关。     

三氧化二砷诱导血管内皮细胞凋亡和抑制血管生成的实验研究

 目的研究三氧化三砷(As2O3)抑制人脐静脉血管内皮细胞(HUVECs)生长、诱导凋亡和抑制血管生成的作用.方法As2O3与HUVECs共同孵育一定时间后,观察细胞形态学变化,并用MTT方法测定细胞生长抑制率、TUNEL方法检测细胞凋亡;观测As2O3对鸡胚血管生成的影响.结果在0.75～6 μmol/L浓度范围内随药物浓度增加或作用时间延长,细胞生长抑制和细胞凋亡效果越显著;As2O3作用鸡胚绒毛尿囊膜后血管生成减少.结论As2O3抑制HUVECs生长、诱导细胞凋亡,对血管生成有抑制作用.     

氧化砷抑制结肠癌裸鼠皮下移植瘤生长及作用机制的研究

 目的研究氧化砷(As2O3)对人结肠癌SW480细胞裸鼠皮下移植瘤生长的抑制作用及其作用机制.方法建立BALB/C-nu/nu裸鼠SW480结肠癌皮下移植瘤模型,以不同浓度As2O3行腹腔内注射治疗,与5-氟脲嘧啶(5-FU)治疗进行对比,观察移植瘤的瘤重及瘤重抑制率,TUNEL法检测移植瘤SW480细胞凋亡率,免疫组织化学法检测bcl-2,Fas基因表达水平的变化.结果5-FU、低剂量As2O3及高剂量As2O3均能明显抑制裸鼠皮下肿瘤的生长,抑瘤率分别为41.51%、53.21%和58.02%,As2O3对移植瘤的生长抑制作用明显强于5-FU,两者比较有显著性差异(P＜0.01).两种浓度As2O3组SW480细胞凋亡率明显高于5-FU.移植瘤组织中bcl-2蛋白阳性细胞数明显减少,Fas蛋白阳性细胞数明显增加.结论As2O3对结肠癌移植瘤的生长具有明显的抑制作用,可诱导移植瘤SW480细胞凋亡,其作用的分子机制可能是下调bcl-2基因表达,上调Fas基因表达.     

肾透明细胞癌与肾乳头状癌、嫌色细胞癌MRI表现的对照研究

目的 探讨MR动态增强扫描对肾癌亚型的鉴别诊断价值.方法 搜集77例经病理证实的肾癌患者资料,其中透明细胞癌(CCRCC)55例,乳头状癌(PRCC)14例,嫌色细胞癌(CRCC)8例,回顾性分析各亚型肿瘤患者MR平扫及动态增强扫描表现并与病理对照,根据肿瘤及肾皮质增强前后的皮质期、实质期及延迟期信号变化,分别进行百分比测量、肿瘤-肾皮质增强指数计算,并采用单因素方差分析和LSD法进行比较.结果 CRCC多数信号均匀(7/8);CCRCC及PRCC多数信号不均(分别为51/55和13/14)、常见坏死(36/55和7/14),PRCC最常见出血(9/14)及囊变(9/14).动态增强各期CCRCC强化程度最高,强化模式呈"快进快退",CRCC轻至中度强化,PRCC强化最轻,两者均呈渐进性延迟强化.CCRCC、PRCC及CRCC皮质期信号变化分别为(296.15±60.27)%、(79.70±18.84)%和(119.56±40.76)%,实质期分别为(236.33±58.31)%、(122.81±27.35)%和(163.06±33.91)%,延迟期分别为(216.83±46.72)%、(117.55±20.63)%和(179.72±32.89)%;三者皮质期的肿瘤-皮质增强指数分别为1.26±0.34、0.33±0.12及0.54±0.10,实质期分别为0.92±0.23、0.41±0.23及0.62±0.15,延迟期分别为0.76±0.14、0.35±0.11及0.69±0.12,各亚型增强各期的信号变化(F值分别为940.931、124.515、38.194,P值均＜0.01)、肿瘤-皮质增强指数(F值分别为798.625、78.308、73.699,P值均＜0.01)差异均有统计学意义.3种亚型的MRI表现与病理学所见基本相符.结论 CCRCC、PRCC及CRCC的MRI动态增强有一定特征性的表现,与其病理特点密切相关,在肾癌亚型的鉴别诊断上有着较高的临床应用价值.

Abstract：

Objective To investigate the differential diagnostic features of subtypes of renal cell carcinoma(RCC) using dynamic contrast-enhanced MRI(DCE-MRI).Methods The MRI appearances of 77 RCCs, including 55 clear cell RCCs(CCRCC),14 papillary RCCs(PRCC) and 8 chromophobe RCCs(CRCC), were retrospectively analyzed and compared with findings of pathology. DCE-MRI was conducted in each case after intravenous administration of contrast agent. Region of interest measurements (cortical, nephrographic and delayed Phases) of signals within tumor and uninvolved renal cortex were used to calculate percentage signal intensity change and tumor-to-cortex enhancement index, and the data was analyzed by AVONA and t test. Results On unenhanced and enhanced MRI, most CRCCs showed homogeneous signal(7/8). CCRCC and PRCC often show inhomogenous signal with necrosis(36/55, 7/14). Hemorrhage and cystic degeneration were often found in PRCC (9/14). On the cortical, nephrographic and delayed phase images, CCRCCs showed greater signal intensity change[(296.15±60.27)%, (236.33±58.31)% and (216.83±46.72)%,respectively than PRCCs (79.70±18.84)%, (122.81±27.35)% and (117.55±20.63)%, respectively], and CRCCs showed intermediate change [(119.56±40.76)%, (163.06±33.91)% and (179.72±32.89)%, respectively].A phenomenon of quick staining and quick fainting was observed in CCRCCs. Both of CRCCs and PRCCs showed delayed enhancement. The tumor-to-cortex enhancement index at the cortical, nephrographic and delayed phases was highest for CCRCCs (1.26±0.34, 0.92±0.23 and 0.76±0.14, respectively), lowest for PRCCs (0.33±0.12, 0.41±0.23 and 0.35±0.11, respectively), and intermediate for CRCCs (0.54±0.10, 0.62±0.15 and 0.69±0.12, respectively,P＜0.01). The degree of enhancement was significantly different among the 3 subtypes at the every contrast enhanced phase (F=940.931, 124.515 and 38.194, P＜0.01), so was the tumor-to-cortex enhancement index(F=798.625,78.308 and 73.699, P＜0.01). There was a good consistency between MR appearances of the 3 RCC subtypes and pathological characteristics. Conclusion DCE-MRI could distinctly show imaging features of CCRCC, PRCC and CRCC, which were related to their pathological characteristics, and these features were helpful in predicting a specific subtype of RCC.     

Fluorodeoxyglucose cell incorporation as an index of cell proliferation: evaluation of accuracy in cell culture

The use of fluorodeoxyglucose (FDG) and positron emission tomography (PET) is recognized as an accurate tool for the specific diagnosis and staging of cancer. It has also been proposed for the monitoring of anticancer therapy. FDG cell incorporation reflects glycolytic activity whereas inhibition of cell proliferation corresponds to an efficient cancer treatment. The relationship between FDG incorporation and cell proliferation has yet to be demonstrated. Therefore, we aimed to correlate the effects of the toxic agents bleomycin and unlabelled meta-iodobenzylguanidine (mIBG) on cellular metabolism and proliferation. We determined the in vitro metabolic and cytotoxic effects of bleomycin and mIBG by measuring the incorporation of fluorine-18 FDG (%U_FDG) and hydrogen-3 thymidine (%U_THY) in cells of the human premonocytic line U937 in the presence of increasing concentrations of these agents. Proliferation rate of these cells was studied by means of limiting dilution analysis. %U_THY appeared more sensitive to bleomycin or mIBG-mediated cell injury than %U_FDG. After 1 h of exposure to 0.5 M bleomycin, %U_THY was significantly reduced to 62.0% ± 10.4% of control value whereas %U_FDG remained unchanged (91.6% ± 5.3%). Similar results were obtained after 1 h of exposure to increasing concentrations of mIBG (1 M to 1 mM). After 20 h of exposure to bleomycin, %U_THY and %U_FDG were significantly reduced as a function of concentration. After 20 h of exposure to mIBG, a transient increase in %U_FDG up to 149.3% ± 11.2% with 50 M mIBG was further followed by a reduction to 20.1% ± 6.7% with 0.5 mM (P < 0.001). The clonogenic efficiency was reduced as a function of bleomycin (ANOVA, n=255, P) or mIBG concentration (n=80, P) and nearly abolished with 0.1 M bleomycin or 0.1 mM mIBG. In conclusion, %U_THY appears to be a more sensitive index of cytotoxicity in vitro and more accurately relates to cell proliferation than %U_FDG. Correspondence to: D.O. Slosman, Nuclear Medicine Division, Geneva University Hospital, CH-1211 Geneva 14, Switzerland     

Potency of different red light sources in photodynamic induction of cell death in a squamous cell carcinoma cell line

LED illumination systems were found to be more efficacious than broad spectrum lamps in recent phase III trials on photodynamic treatment of actinic keratosis. However, a detailed comparison of the light doses emitted at the appropriate spectral range and its correlation to photodynamic effects is thus far not available for the most frequently used devices. Here, we compared the spectral emissions of three different PDT lamps with their potency of inducing cell death in ALA-loaded A431 cells, including a new system equipped with more advanced LEDs matching the photosensitizer absorption peak more precisely and emitting more homogeneous light over time. Cells were exposed to two different ALA concentrations, incubated for 1 or 3 h and then illuminated by one of two different LED or a broad-spectrum system at four different light doses, whereupon viability was assessed. Maximal doses were selected in accordance to clinically applied light doses in recent phase III studies and the manufacturers’ recommendations. The data gathered here clearly demonstrate that the two LED systems were significantly more effective in inducing cell death than the broad spectrum system. Most efficient was the newer LED system, in agreement with emission parameters that more accurately corresponded to the photosensitizer’s absorption peak.     

肾透明细胞癌预后相关分子生物标志物研究进展

肾癌是目前泌尿系统常见的恶性肿瘤之一,发病率占全身恶性肿瘤的3%,而肾透明细胞癌占肾癌的70%～80%。针对晚期或转移性肾癌的抗肿瘤血管生成的分子靶向治疗已取得令人满意的疗效,但肾癌生物学行为极为复杂多变,目前仍缺乏对肾癌患者预后以及靶向药物治疗效果进行评价的有效分子标志物。本文综述了与肾透明细胞癌预后密切相关的肿瘤分子标志物的研究进展。     

儿童郎格尔汉斯细胞增生症的CT表现（附13例分析 ）

目的 探讨CT对郎格尔汉斯细胞组织细胞增生症（Langerhans cell histocytosis,LCH)造成多脏器损害诊断的价值及限度。方法 分析13例经临床、实验室、病理检查确诊的LCH的CT表现。局限性LCH4例,广泛性LCH9例。全部病例均行颅脑、胸部、肝、脾CT平扫检查,4例行增强检查。结果 男性多于女性,颅穹隆骨破坏依次为颞骨8例、顶骨3例、枕骨2例、额骨1例。CT发现早期骨破坏敏感性高。肿块变化可反映病变由活跃增殖到静止消退的病理过程。下丘脑－垂体轴侵犯影像表现晚于临床。CT可显著LCH不同阶段的肺损害。结论 LCH各脏器损害的影像学表现缺乏特异性。好发部位的典型CT表现可提示诊断,同时对辅助LCH分型、确定治疗方案、估计预后有一定价值。     

Sickle cell considerations in athletes

This article highlights the exertional-sickling collapse syndrome in athletes with sickle cell trait (SCT). It covers all aspects of this syndrome, including pathophysiology, new research on microcirculatory changes, clinical features, differential diagnosis, prevention, and treatment. Also covered in this article are other clinical concerns for athletes with SCT, including lumbar myonecrosis, splenic infarction, hematuria, hyposthenuria, and venous thromboembolism. The final section offers practical points on athletes with sickling hemoglobinopathies more serious than SCT.     

Malignancy in giant cell tumor

Malignant giant cell tumor is a confusing term that in the past has been used to describe different types of giant cell-rich tumors. We try to clarify this term in this report. We consider two types of malignancy in giant cell tumor of bone: "primary" when it arises in juxtaposition to a benign giant cell tumor and 'secondary' when it arises at the site of a previously treated giant cell tumor. Here we present a case of primary malignancy in giant cell tumor that was initially not recognized as a malignancy. On radiography and histology of frozen sections the lesion had the appearance of a conventional giant cell tumor of bone. After curettage, the permanent histology slides showed areas of highly malignant osteosarcoma juxtaposed to areas of benign giant cell tumor. The patient was treated with chemotherapy and wide resection of the tumor.     

Sickle cell trait in sports

Sickle cell trait (SCT) can pose a grave risk for some athletes. In the past decade in NCAA Division I football, no deaths have occurred from the play or practice of the game, but 16 deaths have occurred from conditioning for the game, and 10 (63%) of these deaths are tied to SCT, an excess of up to 21-fold. Research shows how and why, during intense exercise bouts, sickle cells can accumulate and "logjam" blood vessels, causing explosive rhabdomyolysis that can kill. Sickling can begin in 2 to 5 min of all-out exertion and can reach grave levels soon thereafter if the athlete struggles on or is urged on by coaches despite warning signs. Sickling collapse is an intensity syndrome that differs from other common causes of collapse. Tailored precautions can prevent sickling collapse and enable athletes with SCT to thrive. Irrationally intense conditioning for a game puts the lives of healthy athletes with SCT at risk.     

干细胞治疗新进展

治愈各种各样的疾病 ,数量无限 ,为您量身定制……中国生命科学家徐荣祥教授在干细胞研究和应用领域取得的科研进展对于科学家和广大的普通百姓们来说已经不再是天方夜潭 ,而是带来了希望。干细胞技术被美国《科学》杂志冠以“1999年度排名第一的科学成就”和“医学的未来”。自从生物学家ＪａｍｅｓＴｈｏｍｓｏｎ首先宣布他在培养皿内培养出人类胚胎干细胞 ,科学家们就对干细胞在医学上的潜在的应用前景兴奋不已。干细胞具有产生构成身体各种类型细胞的潜能 ,这些细胞可取代因衰老、创伤或疾病而损伤的组织。数月前 ,加利福尼亚大学洛杉矶…