RNA干扰下调YAP基因对甲状腺癌细胞TPC-1功能的影响

目的 检测siRNA沉默Yes相关蛋白(Yes associated protein,YAP)后的人甲状腺癌TPC-1细胞功能变化。方法 应用阳离子脂质体转染试剂LipofectamineTM2000将靶向沉默YAP基因的siRNA序列转染至甲状腺癌TPC-1细胞,应用qRT-PCR、Western印迹法检测转染后TPC-1细胞YAP基因及蛋白表达,MTT、平板克隆实验、Transwell小室、划痕实验和流式细胞术分别检测转染对细胞增殖、侵袭、迁移和细胞周期及凋亡的影响。结果转染siRNA后,YAP mRNA和蛋白表达明显下降(P<0.05);TPC-1细胞的增殖、侵袭、迁移能力受到抑制,细胞周期G₀/G₁阻滞,细胞凋亡未明显上升。结论 抑制甲状腺癌细胞YAP表达可有效降低细胞的增殖、迁移和侵袭能力,改变细胞周期分布,但对细胞凋亡无明显影响。     

靶向调控TOX3基因对乳腺癌细胞增殖及周期的影响

目的 研究TOX3基因对人乳腺癌细胞增殖能力及细胞周期的影响。方法 采用Western blot法检测已构建的稳定沉默TOX3的ZR-75-1细胞和稳定过表达TOX3的MDA-MB-231细胞中TOX3蛋白的表达。MTT法检测过表达和干扰TOX3基因对乳腺癌细胞增殖活性的影响。平板单克隆实验检测过表达TOX3对MDA-MB-231细胞单克隆形成能力的影响,流式细胞术检测沉默或过表达TOX3后ZR-75-1和MDA-MB-231细胞周期的变化。结果 与阴性对照组比较,稳定沉默TOX3的乳腺癌ZR-75-1细胞TOX3蛋白表达明显下降,过表达TOX3的MDA-MB-231细胞TOX3蛋白表达明显上调。过表达TOX3后,MDA-MB-231细胞的增殖活性明显增强,单克隆形成能力增强,G₀/G₁期细胞所占比例明显减少,G₂/M期细胞比例增多。干扰TOX3后,ZR-75-1细胞增殖活性下降,G₀/G₁期细胞比例增加,G₂/M期细胞比例减少。结论 靶向调控TOX3基因的表达可改变乳腺癌细胞增殖和单克隆形成能力,影响乳腺癌细胞周期。     

microRNA干扰抑制MTDH的表达对乳腺癌细胞MDA-MB-231增殖和侵袭能力的影响

目的 探讨microRNA干扰技术沉默异黏蛋白（MTDH,metadherin蛋白）基因表达及对人乳腺癌细胞MDA-MB-231细胞增殖、转移、侵袭能力的影响。方法 将人工合成的针对MTDH基因的miRNA片段瞬时转染人乳腺癌细胞MDA-MB-231,通过Western blot法、RT-PCR法检测MTDH蛋白表达和MTDHmRNA;应用MTT检测法、划痕实验、Transwell实验检测抑制MTDH基因后对乳腺癌细胞增殖、转移、侵袭能力的影响。结果 MTDHmiRNA能有效抑制MTDH蛋白和MTDHmRNA表达,最佳抑制率分别为79.41%、80.56%（P<0.05）;经miRNA干扰的细胞,生长速度明显受到抑制（P<0.05）,侵袭迁移能力显著下降（P<0.05）。结论 MTDH miRNA瞬时转染人乳腺癌MDA-MB-231细胞可明显抑制癌细胞中MTDH表达,沉默MTDH基因表达后可明显抑制人乳腺癌MDA-MB-231细胞生长增殖、侵袭迁移能力。     

去乙酰化修饰调控瘦素诱导乳腺癌细胞增殖的分子机制

【目的】 研究去乙酰化修饰在瘦素(Leptin)诱导的乳腺癌细胞增殖过程中的调控作用。 【方法】 应用MTT法测定Leptin对乳腺癌MDA-MB-231细胞生长的诱导作用,并测定乳腺癌细胞活力、侵袭力及细胞周期的变化情况;实时定量PCR、蛋白质印迹法测定Leptin诱导后MDA-MB-231细胞周期关键因子及相关酶的表达情况;染色质沉淀法(ChIP)检测Leptin作用MDA-MB-231细胞后核心组蛋白H3、H4乙酰化水平变化情况。 【结果】 Leptin诱导乳腺癌MDA-MB-231细胞增殖呈现时间和剂量依赖性,1.25 nm (20 mg/mL)、24 h为Leptin最佳作用浓度和孵育时间;经Leptin处理后,乳腺癌MDA-MB-231细胞凋亡明显减少、活力增强,同时由G₁进入S期的细胞显著增多;荧光显微镜观察发现Leptin诱导后BrdU荧光染色增强,且主要集中在MDA-MB-231细胞核内;Transwell小室侵袭实验也显示细胞侵袭力增强;实时定量PCR及蛋白质印迹法检测 发现Leptin处理后的 MDA-MB-231细胞中与G₁/S 期限制点调控相关的细胞周期调控因子CDK2、cyclin E1以及与抑制细胞凋亡有关的Bcl-2均显著增加,细胞中HDAC酶活性增强,且与细胞周期G₁/S 期调控密切相关的HDAC1 mRNA及蛋白表达水平也明显增强;ChIP 实验发现Leptin处理后的乳腺癌MDA-MB-231细胞中GAPDH 启动子区域核心组蛋白乙酰化水平显著降低,而经HDAC抑制剂SAHA阻断后MDA-MB-231细胞p21WAF 1/CIP 表达水平显著提高。 【结论】 Leptin通过HDAC1的去乙酰化修饰抑制p21WAF 1/CIP的表达,激活细胞周期关键因子CDK 2、cyclin E1的表达,从而加速乳腺癌细胞周期G₁/S 期的进程。     

siRNA干扰整合素β4的表达对MDA-MB-231乳腺癌细胞侵袭和迁移的影响

目的采用RNA干扰（Small interference RNA,siRNA）技术抑制MDA-MB-231乳腺癌细胞中整合素β4（integrinβ4）基因表达,观察其对细胞侵袭和迁移能力的影响。方法选用MDA-MB-231乳腺癌细胞为研究对象,应用siRNA技术沉默癌细胞Integrinβ4 mRNA的表达,Real-time PCR和Western blotting方法分别检测未转染Integrinβ4 siRNA的乳腺癌细胞组（简称空白对照组）及转染Integrinβ4 siRNA的乳腺癌细胞组（简称Integrinβ4 RNA干扰组）的Integrinβ4 mRNA和蛋白表达水平;Transwell实验检测两组细胞的侵袭及迁移能力。结果与空白对照组相比,Integrinβ4 RNA干扰组Integrinβ4的mRNA及蛋白表达水平分别降低了86%（P〈0.01）和89%（P〈0.01）,细胞侵袭和迁移能力下降（P〈0.05）。结论应用siRNA干扰技术抑制Integrinβ4表达可使MDA-MB-231细胞迁移及侵袭能力降低,提示Integrinβ4在乳腺癌侵袭转移中发挥重要作用。     

RSRC2影响三阴性乳腺癌细胞增殖迁移及侵袭的初步研究

目的:探究富含精氨酸/丝氨酸卷曲螺旋2（RSRC2）对三阴性乳腺癌细胞生物学行为的影响。方法:将RSRC2过表达、降表达和空载体质粒通过慢病毒包装转染至三阴性乳腺癌细胞MDA-MB-231中,通过Western blot检测转染效果,通过Transwell 迁移实验、侵袭实验、划痕实验检测RSRC2对MDA-MB-231细胞迁移、侵袭能力的影响,通过平板克隆形成实验检测RSRC2对MDA-MB-231细胞增殖能力的影响。结果:Western blot结果显示RSRC2过表达和降表达质粒成功转染至MDA-MB-231细胞中,Transwell迁移实验、侵袭实验、划痕实验、平板克隆实验显示,RSRC2过表达的MDA-MB-231细胞其迁移、侵袭及增殖能力减弱,RSRC2降表达的MDA-MB-231细胞其迁移、侵袭及增殖能力增强（均P<0.05）。结论:RSRC2在三阴性乳腺癌细胞增殖、迁移及侵袭过程中起着重要的负调控作用。     

特异性小干扰RNA沉默Annexin Ⅱ基因表达对人乳腺癌细胞MDA-MB-231侵袭迁移力的影响

目的:探讨RNA干扰技术沉默Annexin Ⅱ基因表达对人乳腺癌细胞MDA-MB-231侵袭迁移力的影响.方法:体外化学合成AnnexinⅡ基因序列特异性双链小干扰RNA(Annexin Ⅱ-siRNA),转染高转移人乳腺癌细胞株MDA-MB-231,用荧光显微镜观察转染效率,逆转录-聚合酶链反应和蛋白印迹检测Armexin Ⅱ mRNA和蛋白表达水平;通过生长曲线和体外侵袭迁移实验,观察乳腺癌细胞恶性生物学行为的改变.结果:Annexin Ⅱ-siRNA能有效抑制Annexin Ⅱ mRNA和蛋白表达(P<0.05);经siRNA处理的细胞,细胞生长速度明显降低(P<0.05),侵袭迁移力显著下降(P相似文献   

调控CIAPIN1基因表达对食管癌细胞生长及侵袭性的影响

目的 采用重组慢病毒CIAPIN1表达载体和CIAPIN1沉默载体感染食管癌EC9706细胞,观察调控CIAPIN1基因表达对细胞增殖、细胞周期、细胞凋亡及体外侵袭转移的影响。 方法 构建CIAPIN1表达慢病毒载体和CIAPIN1 siRNA慢病毒载体,包装得到重组慢病毒;分别感染食管癌EC9706细胞,筛选得到稳定CIAPIN1基因高表达和低表达的细胞。实验分为CIAPIN1表达组、CIAPIN1 siRNA组、无关siRNA对照组和空白对照组。采用RT-PCR和蛋白质印迹法分析CIAPIN1基因和蛋白的表达,MTT实验检测细胞增殖,流式细胞术(FCM)分析细胞周期及细胞凋亡的变化, Boyden小室检测细胞侵袭转移。 结果 与空白对照组、无关siRNA对照组和CIAPIN1 siRNA组比较,CIAPIN1高表达组细胞生长受到抑制(P<0.05);S和G₂/M期细胞比例减少,G₀/G₁期细胞比例增加(P<0.05);平均细胞凋亡率增加(P<0.05),穿透Matrigel的平均细胞数减少(P<0.05)。 结论 以慢病毒为载体介导的CIAPIN1基因高表达可有效抑制食管癌EC9706细胞增殖、促进细胞凋亡和降低细胞侵袭迁移能力。     

miR-99a对乳腺癌细胞侵袭和迁移的负向调控机制研究

目的探讨miR-99a对乳腺癌细胞侵袭及迁移的影响,并初步分析其影响乳腺癌细胞侵袭及迁移的可能分子机制。方法利用荧光实时定量PCR检测乳腺癌细胞系MDA-MB-231和MCF-7中miR-99a的表达。运用脂质体介导的转染方法分别将miR-99a模拟物（miR-99amimics）、miR-99a抑制物（miR-99ainhibitors）以及相应对照miRNA转染MDA-MB-231和MCF-7细胞,通过Transwell侵袭实验检测细胞的侵袭力;采用Transwell迁移实验及划痕实验检测细胞的迁移能力;利用生物信息学方法预测miR-99a的靶基因,并对靶基因进行验证。结果（1）高转移潜能的MDA-MB-231细胞中miR-99a表达明显低于低转移潜能的MCF-7细胞,划痕实验中转染miR-99amimics的与转染controlmimics的MDA-MB-231细胞比较迁移能力显著减弱（P＜0.05）,而MCF-7细胞转染miR-99ainhibitors后迁移能力明显增强（P＜0.01）。（2）Transwell的侵袭及迁移实验显示,转染miR-99amimics后MDA-MB-231细胞的侵袭和迁移能力明显减弱（P＜0.01）;MCF-7细胞转染miR-99ainhibitors后迁移能力增强（P＜0.01）,而侵袭能力基本不变（P＞0.05）。（3）生物信息学方法预测微管相关蛋白（MTMR3）是miR-99a的靶点,实时定量PCR和3′UTR荧光素酶报告基因实验验证了该靶点。（4）干扰了MTMR3后MDA-MB-231细胞的迁移和侵袭能力明显减弱。结论（1）miR-99a对乳腺癌细胞的侵袭及迁移发挥负向调控作用。（2）miR-99a可能通过靶向于MTMR3发挥其对乳腺癌细胞迁移和侵袭的调控作用。     

BRG1对乳腺癌细胞迁移和侵袭的影响及其分子机制探讨

目的探讨沉默BRG1基因对乳腺癌细胞迁移和侵袭的影响及其分子机制。方法体外化学合成BRG1小干扰RNA（siRNA）和Control siRNA（si—Ctr1）,脂质体介导转染乳腺癌MDA—MB-231和BT-549细胞,Transwell迁移实验和侵袭实验观察沉默BRG1基因对2种乳腺癌细胞迁移和侵袭能力的影响,明胶酶谱实验检测基质金属蛋白酶-2（matrix metalloproteinase-2,MMP-2）变化,Westernblot检测基质金属蛋白酶组织抑制因子-2（tissue inhibitor of metalloproteinase-2,TIMP-2）及MMP-2蛋白表达。结果转染BRG1 siRNA可以有效减少乳腺癌MDA—MB-231和BT-549细胞BRG1的表达,细胞迁移和侵袭能力下降。BRG1沉默后TIMP-2表达升高,MMP-2表达下降且酶活性降低。结论BRG1沉默后通过上调TIMP-2抑制MMP-2的表达,破坏TIMP-2／MMP-2平衡,最终抑制乳腺癌细胞迁移和侵袭能力。     

Value of D-Dimers in patients with acute aortic dissection

Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P ＜ 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (＞0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P ＜0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P ＜ 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.     

Research of combined liver-kidney transplantation model in rats

Objective： To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods： SD rats served as both donors and recipients. 4℃ sodium lactate Ringer＇s was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava （IVC） inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results： Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion： This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.     

BLOOD PRESSURE CHANGE WITH AGE IN SALT-SENSITIVE TEENAGERS

Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P＜ 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P＜ 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

目的：评价使用安心颗粒对急诊经皮冠状动脉介入术（PPCI）术后生活质量的影响.方法：将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组（术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次）和对照组（仅接受基础药物治疗）.所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表（MIDAS）、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果：入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异（P＞0.05）;出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低（P＜0.05）;组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低（P＜0.05）.两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血（P＞0.05）.两组发生轻度血小板减少症的患者数比较无差异（P＞0.05）.结论：PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.     

The comparative studies of the influences of Urapidil and Nicardipine on sino-atrial node function, atrio-ventricular node function and hemodynamics

Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P＜0.01);the MAP decreased(P＜0.01)and the HR increased drastically(P＜0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.     

Expression of OPGmRNA and ODFmRNA in the patients of hip fracture due to osteoporosis

Objective：To investigate the gene expression of osteoprotegerin（OPG） and osteoclast differentiation factor（ODF） in the bone tissue of patients with hip fracture due to osteoporosis. Methods：OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers（over 50 years old） with hip fracture（Observer Group） and 30 cases of hip facture sufferers with no osteoporosis（Control group） were analyzed with the Semi-Quantitative RT-PCR method. Results：The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion：Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.     

The clinicopathological and immuohistochemical analysis of solid-pseudopapillary tumor of the pancreas： report of 9 cases

Objective：To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas（SPTP）. Methods：Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin（HE） staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results：Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin（9/9 cases）, AAT（9/9 cases）, NSE（9/9 cases）, ACT（7/9 cases）, CK20（2/9 cases）, CgA（1/9 cases）, S-100（3/gcases）, PR（4/gcases）, Syn（3/9 cases） and CD56（5/9cases）, negative in CEA and ER. Conclusion：SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.     

Dynamic Changes in Serum Estradiol and Progesterone levels in Patients of Premenstrual Syndrome with Adverse Flow of Liver-qi

Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.     

Real-time Three-dimensional Echocardiography in Assessment of Left Ventricular and Right Ventricular Volumes

Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.     

SCREENING FOR A 21-CHROMOSOME ABNORMALITY IN PREIMPLANTED EMBRYOS OF ELDERLY WOMEN

Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.