人胶质细胞源性神经营养因子在肌萎缩性脊髓侧索硬化症小鼠模型基因治疗中的作用

目的 探讨人胶质细胞源性神经营养因子(GDNF)基因治疗在肌萎缩性脊髓侧索硬化症(ALS)中的作用。方法 ALS小鼠随机分成AdCMVlacz对照组和AdCMVgdnf治疗组各12只。第9周肌肉注射AdCMVgdnf或AdCMVlacz病毒。第10周测试运动能力,并记录发病时间和生存时间。利用ELISA和免疫组织化学检测骨骼肌肉和脊髓中GDNF的表达,对脊髓运动神经元细胞数目和腓肠肌质量变化进行定量分析。结果 ① AdCMVgdnf治疗组ALS小鼠注射部位肌肉中GDNF水平为(6589.0±325.0)pg/mg,而对照组为（75.3±18.9） pg/mg,治疗组高于对照组近100倍（P＜0.01）。② 对照组的腓肠肌质量为（88.6±14.5)mg,治疗组为（174.9±18.7）mg,差异有统计学意义（P＜0.01）。③ 治疗组脊髓运动神经元细胞中GDNF较对照组明显增加,并且神经元细胞数目也明显增加（P＜0.01）。④与对照组的发病时间（96.2±5.8）d比较,治疗组为（123.0±6.9 ）d,差异有统计学意义（P＜0.01）。与对照组生存期(127.3±4.6) d比较,治疗组为（155.2±4.1） d,差异有统计学意义（P＜0.01）。结论 AdCMVgdnf基因治疗对ALS小鼠脊髓运动神经元有保护作用,缓解肌肉萎缩,改善神经运动功能,延缓疾病的发生和延长生存期。     

刺五加皂苷对体外培养大鼠脊髓运动神经元缺氧损伤的保护作用

目的:观察刺五加皂苷(acanthopanax senticosus saponins, ASS)对脊髓运动神经元缺氧损伤有无保护作用,并探讨其可能机制.方法:对胚鼠运动神经元进行原代分离培养,免疫组化鉴定后建立缺氧诱导的神经元凋亡模型.取运动神经元培养在24孔板中,每组10孔,分为4组:对照组,无缺氧损伤;缺氧损伤组;ASS保护组,缺氧前24 h加入50 μg/ml的ASS;神经胶质细胞源性神经营养因子(GDNF)保护组,缺氧前24 h加入0.1 μg/ml的GDNF.倒置显微镜及电镜下观察细胞形态学变化;MTT法测定神经元细胞活性;检测细胞外液LDH释放量来观察ASS对神经元细胞膜稳定性的影响.提取细胞匀浆液,Western印迹法检测分析ASS对缺氧的运动神经元HIF-1α表达的影响.结果:形态学观察显示ASS、GDNF保护组神经元缺氧损伤较缺氧损伤组明显减轻.ASS保护组神经元的细胞活性(0.21±0.028)比缺氧损伤组(0.15±0.012)高(P<0.05),而LDH的释放量(28.6±1.309)比缺氧损伤组(40.7± 1.885)低(P<0.01);缺氧损伤组的神经元HIF-1α的相对表达量(0.72±0.027)比对照组(0.16±0.003)高(P<0.01),但ASS保护组HIF-1α的表达(1.15±0.016)最高(P<0.01).ASS对大鼠脊髓运动神经元缺氧损伤的保护作用与GDNF相仿.结论:ASS可以提高体外缺氧损伤的运动神经元的细胞活性,对细胞的缺氧损伤有明显的保护作用,其保护作用的发挥,可能与增强细胞膜的稳定性及提高细胞HIF-1α的表达有关.     

靶向于SW1990细胞K-ras exon 1反义RNA腺病毒的构建

目的:构建靶向于SW1990细胞K-ras exon 1序列的反义RNA腺病毒,观察其对SW1990细胞的增殖和凋亡的影响.方法:将K-ras exon 1 cDNA克隆至穿梭质粒pShuttle-CMV,筛选出反向插入的克隆,与腺病毒骨架质粒pAdEasy-1共转染大肠杆菌BJ5183,同源重组产生腺病毒重组质粒.腺病毒重组质粒转染293细胞进行包装,产生重组腺病毒.腺病毒载体Ad-LacZ转染SW1990细胞,X-gal染色观察感染效率.重组腺病毒感染体外培养的SW1990细胞,MTT法检测SW1990细胞增殖,AnnexinⅤ/PI流式细胞术检测SW1990细胞凋亡.结果:所构建的重组腺病毒PCR扩增出282 bp的目的基因片段;制备出了高滴度重组病毒,CsCl2密度梯度纯化前后病毒滴度分别为7.6×108pfu/ml和5.0×1010 pfu/ml,当MOI=100时对SW1990的感染效率接近100%;重组腺病毒体外转染能抑制SW1990细胞增殖(P＜0.05),转染后4～5 d,抑制效应达到最高峰,抑制率约为40.5%,也能促进SW1990细胞凋亡,转染后72 h,凋亡率为 (22.54±5.38)% (P＜0.01). 结论:成功构建了靶向于SW1990细胞K-ras exon 1序列的反义RNA腺病毒,为进一步探讨胰腺癌以K-ras为靶点的反义基因治疗奠定了基础.     

胶质源性神经营养因子对脊髓损伤后前角运动神经元的保护作用

目的 :探讨胶质细胞源性神经营养因子 (GDNF)对脊髓损伤后运动神经元的保护作用。 方法 :大鼠分为假手术组、生理盐水 (NS)组和 GDNF组 ,改良 Allen法撞击致伤 T1 2 脊髓 ,蛛网膜下腔分别给予 NS和 GDNF,分别取不同时间的伤段脊髓进行切片 ,应用酶组织化学染色方法显示脊髓前角外侧核运动神经元中胆碱酯酶 (Ch E)和酸性磷酸酶 (ACP)活性 ,并结合计算机进行图像分析。结果 :GDNF组较 NS组 Ch E活性显著增加 ,ACP活性显著降低 ;2 1d时 NS组的 ACP及 Ch E活性均高于及低于假手术组 ;GDNF组与假手术组 Ch E和 ACP活性差别不显著。 结论 :GDNF对脊髓损伤后的前角外侧核运动神经元有一定的保护作用     

腺病毒介导的脑源性神经营养因子基因脊髓内转移对神经根损伤后细胞凋亡的影响

目的观察腺病毒介导的脑源性神经营养因子（BDNF）基因脊髓内转移对神经根损伤后细胞凋亡的影响。方法在大鼠神经根切断吻合模型基础上,通过显微注射法在立体定位仪上将复制缺陷型重组腺病毒载体（AxCA-BDNF）直接转移至大鼠神经根损伤部相应的脊髓腹角。术后1、3、7、14、28d利用DNA末端原位标记、免疫组化、原位杂交,观察脊髓凋亡细胞、Caspase-3、bcl-2及iNOS表达的改变。结果神经根损伤诱导Caspase-3和iNOS的表达,触发运动神经元凋亡;AxCA-BDNF治疗后腹角运动神经元不但较少表达Caspase-3和iNOS,而且bcl-2表达增加,发生凋亡的细胞减少。结论AxCA-BDNF介导的外源性BDNF基因转染对脊髓运动神经元具有保护作用,其作用机制与AxCA—BDNF抑制内源性的死亡程序有关。     

重组腺病毒Ad-shRNA-NgR在大鼠缺血脑组织的转染效率研究

目的探索用于RNA干扰的重组腺病毒Ad-shRNA-NgR转染大鼠缺血脑组织的适宜滴度。方法将低、中、高3种不同滴度(7.90×109、1.58×1010、3.16×1010pfu/ml)的重组腺病毒通过立体定位手术注射到大脑中动脉阻塞(middle cerebral artery occlusion,MCAO)/再灌注模型大鼠(n=10)脑缺血区,于术后48 h和1周在荧光显微镜下观察各组大鼠脑组织中绿色荧光蛋白(green fluorescent protein,GFP)的表达强度并估算转染效率,通过HE染色检测炎性反应。结果中滴度和高滴度注射组大鼠脑组织腺病毒转染效率相似,为60%～70%,明显高于低滴度注射组(P<0.01)。在各组脑组织切片中,仅高滴度注射组有明显炎症反应,血管周围可见淋巴和巨噬细胞浸润。结论中等滴度(1.58×1010pfu/ml)的腺病毒能高效、稳定、低毒地转染大鼠缺血脑组织,推荐用于脑缺血基因干预治疗的实验研究。     

Ad-hNGFβ转染原代培养的大鼠脊髓星形胶质细胞及其生物活性研究

目的:体外培养新生SD大鼠脊髓星形胶质细胞,观察携带人β神经生长因子基因的重组腺病毒(Ad-hNGFβ)对其存活及毒性作用,为Ad-hNGFβ在体研究打下基础。方法:分离新生SD大鼠的脊髓星形胶质细胞(Astrocyte,Ast),应用DMEM/F-121∶1培养基进行原代培养扩增鉴定。重组Ad-hNGFβ(MOI=25,50,100)转染Ast后,噻唑蓝(MTT)法检测病毒感染滴度与细胞存活的关系。ELISA方法测定培养3,6,9,12,15d时培养上清中hNGFβ的含量;用流式细胞仪对转染细胞进行倍体分析,观察转染Ad-hNGFβ对细胞周期和凋亡的影响;Western blot印迹法测定转染后表达产物的存在形式。结果:从新生SD大鼠的脊髓组织中成功分离培养出星形胶质细胞,GFAP免疫荧光阳性。经MTT法测定,当MOI=25,50,100时试验组的吸光值OD490与对照组比无显著差异,P>0.05。转染Ad-hNGFβ后试验组细胞培养上清中hNGFβ表达量与对照组同期相比有显著差异,P<0.01;且hNGFβ可持续表达至15d。Ad-hNGFβ转染细胞后所表达的活性产物以hNGFβ二聚体的形式存在。流式细胞仪测得细胞增殖指数与对照组比明显升高,P<0.01。结论:Ad-hNGFβ可有效介导hNGFβ基因转染原代培养的脊髓星形胶质细胞,并且成功表达有活性的hNGFβ,增加细胞活性。     

胶质细胞源性神经营养因子对运动神经元病培养模型的保护作用

目的 利用运动神经元病的脑片和脊髓片培养模型,观察胶质细胞源性神经营养因子（GDNF）对运动神经元的保护作用.方法 取1日龄SD乳鼠的大脑做脑片培养,取8日龄SD乳鼠脊髓做脊髓片培养.脑片在培养2周后,脊髓片在培养1周后,随机分为对照组、模型组（100 μmol/L THA）、不同浓度GDNF组（1 ng/ml、5 ng/ml和50 ng/ml）,继续培养3周后,SMI-32免疫组化染色,分别计数脑片中皮层运动神经元和脊髓片中前角运动神经元数目的变化,测定培养液中乳酸脱氢酶（LDH）的含量.结果 模型组SMI-32阳性的皮层运动神经元数目和脊髓运动神经元数目较对照组明显减少,差异有显著性意义（P＜0.05）,而GDNF各组神经元存活数目较模型组显著增多,差异有显著性意义（P＜0.05）,脑片组和脊髓片组中的模型组LDH含量均对照组显著增高,差异有显著性意义（P＜0.05）,GDNF各组培养液中LDH含量较对照组均升高,差异有显著性意义（P＜0.05）.结论 GDNF能保护运动神经元免受谷氨酸兴奋毒性的损伤,使得GDNF在临床上治疗MND成为可能.     

腺病毒介导的胶质细胞源性神经营养因子对中度脊髓损伤大鼠的治疗作用

目的 探讨腺病毒介导的胶质细胞源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)体内转染对中度脊髓损伤的治疗作用.方法 将60只成年SD中度脊髓损伤模型大鼠随机分为3组,手术对照组、Ad-LacZ组、Ad-GDNF组.Ad-LacZ组于模型制作成功后立即于损伤处注射Ad-LacZ(1×109pfu/mL)2 μL,Ad-GDNF组注射Ad-GDNF(1×109pfu/mL)2 μL,手术对照组不进行注射.术后检测各组GDNF表达量并进行后肢运动功能评价,术后4周比较各组有效组织保留率.结果 术后Ad-GDNF组GDNF mRNA表达量明显高于其他2组.术后第2周为大鼠神经功能恢复最快的时期,Ad-GDNF组恢复速度最快(P＜0.05).术后4周手术对照组、Ad-GDNF组大鼠后肢运动功能基本恢复正常.Ad-GDNF组比单纯损伤组及Ad-LacZ组组织破坏程度小,有效组织保留率差异有统计学意义(P＜0.05).结论 腺病毒介导的GDNF可以有效地加速中度脊髓损伤神经功能的恢复,缩短恢复时间.     

蛛网膜下隙局部应用GDNF对脊髓前角运动神经元的保护作用

目的 研究周围神经损伤后经蛛网膜下隙置管局部应用外源性胶质细胞源性神经营养因子(glial cell line-derived neu-rotrophic factor,GDNF)对脊髓前角运动神经元的保护作用. 方法 成年SD大鼠随机分为2组:GDNF组(坐骨神经切断术后给予GDNF)和NS组(术后给予生理盐水).切断两组大鼠左侧坐骨神经致相应脊髓前角运动神经元部分损伤,行蛛网膜下隙置管,实验组注入外源性GDNF(10 μg/ml),对照组注入同等剂量的生理盐水,于2,4,8周行坐骨神经功能指数检测;取L4-6节段脊髓标本冰冻切片,行胆碱酯酶(ChE)和酸性磷酸酶(ACP)染色并进行图像分析. 结果 GDNF组脊髓前角运动神经元ChE阳性颗粒面积比NS组有明显提高(P<0.05),ACP阳性颗粒面积低于NS组(P<0.05);GDNF组坐骨神经功能指数亦优于NS组. 结论 周围神经损伤后通过蛛网膜下隙注入外源性GDNF对相应的脊髓运动神经元有保护作用.     

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.