复方丹参滴丸、普罗布考对动脉损伤后内膜增殖与血管重塑的影响

目的：探讨复方丹参滴丸、普罗布考对兔髂动脉损伤后内膜增殖、血管重塑及血管内皮生长因子表达的影响。方法：雄性日本大耳白兔40只,随机平均分为对照组、普罗布考组、复方丹参滴丸组和联合组,高脂喂养两周后行髂动脉球囊内皮拉伤术,从术前3d开始对照组予单纯高脂喂养,治疗组分别以普罗布考（1．0g／只·d^-1）、复方丹参滴丸（300mg／只·d^-1）及两药联合灌喂至术后4周,取病变血管行病理形态学观察,免疫组化检测血管内皮生长因子（VEGF）和增殖细胞核抗原（PCNA）表达水平。结果：与对照组比较,普罗布考组、复方丹参滴丸组增殖内膜面积明显减小（P〈0．05）,普罗布考组内弹力膜包绕面积增大（P〈0．05）;与单独用药组比较,联合组内弹力膜包绕面积明显增大（P〈0．05）,但增殖内膜面积无改变（P〉0．05）;各治疗组VEGF、PCNA表达均较对照组明显减少（P〈0．05）。结论：复方丹参滴丸、普罗布考均可抑制动脉损伤后平滑肌细胞增殖,减轻内膜增生;普罗布考兼有改善血管重塑的作用,两药联合使用可取得改善血管重塑的协同效应,其机制可能与减少VEGF在血管内、中膜的表达水平有关。     

氟伐他汀对高脂血症模型兔血脂的影响及其与内膜增生的关系

为探讨氟伐他汀对血脂的影响及其与内膜增厚的关系 ,将髂动脉内膜剥脱术后高脂血症模型兔随机分为氟伐他汀组和非用药组 (各组n =2 8) ,并设正常对照组 (n =7)。分别于喂高脂饮食前及动脉剥脱术后 1、2、4、8周 ,观察氟伐他汀组和非用药组动物血清TC、TG及LDL C的变化 ;并观察动脉剥脱术后 1、2、4、8周氟伐他汀组和非用药组兔髂动脉切片的新生内膜、中膜厚度及内膜 /中膜比值 (I/M)。结果 :氟伐他汀组血清TC、TG、LDL C浓度明显低于非用药组 (P <0 .0 5) ;氟伐他汀组的新生内膜厚度和I/M明显低于非用药组 (P <0 .0 1 ) ;动脉内膜厚度与TC、TG、LDL C呈明显的直线相关 (偏相关系数分别为 0 .91 1、0 .892、0 .94 2 ,P <0 .0 1 )。提示 :氟伐他汀可调节血脂 ,有效抑制血管内膜过度增生     

白藜三醇对血管内皮剥脱术后内膜增殖的影响

目的:观察白藜三醇对兔髂动脉内皮剥脱后血管内膜增殖的作用。方法:建立兔髂动脉内皮剥脱后血管内膜增殖模型,从术前1周至术后4周,给予2～4mg/(kg·d)的白藜三醇。结果:白藜三醇高剂量可有效地抑制血管内膜的增生,使内膜增生指数从模型组(M组)的0.41降低到白藜三醇高剂量组(H组)的0.28(P<0.01);相对管腔面积从M组的0.39增加到H组的0.53(P<0.001);相同管腔直径的增殖内膜中平滑肌细胞(SMC)数目从M组的1935减少到H组的1115(P<0.05)。结论:提示白藜三醇可抑制血管内膜的增殖,对于预防血管成形术后再狭窄可能具有潜在的临床应用价值。     

重组水蛭素局部治疗兔髂总动脉球囊扩张术后内膜增殖和管腔狭窄

目的　探讨重组水蛭素经多孔球囊导管局部治疗对兔髂总动脉球囊扩张术后内膜增殖和管腔狭窄的影响 .方法　 2 4只纯种日本大耳白兔随机分成对照组 (n=12 )和重组水蛭素局部治疗组 (n=12 ) ,采用兔髂总动脉球囊扩张术后内膜增殖和管腔狭窄动物模型 ,治疗组经多孔球囊导管于球囊扩张局部在 2个大气压下给予重组水蛭素 (13.8× 10 6抗凝血酶单位· g- 1 ) 1mg· kg- 1 ,对照组给予生理盐水 .术后 2 wk和4wk复查血管造影 ,术后 4wk取髂总动脉标本行 HE染色、Masson三色染色、平滑肌肌动蛋白 (α- actin)免疫组织化学染色和增殖细胞核抗原 (PCNA)免疫组织化学染色 ,并进行计算机图像分析 .结果　治疗组术后 2 wk和 4wk平均髂总动脉直径均较对照组显著扩大 [2 wk (86± 5 ) % vs(5 6±10 ) % ,P <0 .0 1;4wk (77± 13) % vs (5 6± 10 ) % ,P <0 .0 1],术后 2 wk和 4wk平均髂总动脉面积亦显著增加 .术后 4wk治疗组球囊扩张血管管腔面积较对照组显著增加[(37± 5 ) % vs (16± 5 ) % ,P <0 .0 1],管壁面积显著减少[(6 3± 5 ) % vs(84± 5 ) % ,P<0 .0 1],其中主要是内膜面积的减少 [(7± 1) % vs (38± 10 ) % ,P<0 .0 1].术后 4wk治疗组球囊扩张血管壁 α- actin和 PCNA免疫组化染色阳性细胞均较对照组明显减     

血管内放射对猪受损髂动脉平滑肌细胞增殖与凋亡的影响

目的 :观察血管内放射照射对猪髂动脉球囊损伤后血管新生内膜平滑肌细胞(SMC)增殖与凋亡的影响。方法 :2 7头小型猪分为 3组 ,所有猪行髂动脉球囊过大扩张 ,通过后装装置将 1 0Gy和 2 0Gy的192 Ir放射源分别置于 9只猪受损髂动脉部位 ,其他 9只猪的受损髂动脉作为对照。每组的 9头猪分别术后 3天、1 0天和 2 8天分 3次处死。用增殖细胞核抗原(PCNA)和三磷酸脱氧尿嘧啶缺口末端标记法 (TUNEL)法检测内膜SMC增殖和凋亡情况。结果 :代表血管内膜增殖的PCNA指数在 1 0天和 2 8天宰杀的猪中 ,放射治疗组明显低于对照组。术后 1 0天内膜SMC凋亡在对照组和 1 0Gy、2 0Gy组的值分别为 :(1 85± 0 49) %比 (2 2 7± 0 49) %(P >0 0 5)和 (1 85± 0 49) %比 (2 53± 0 45) %(P <0 0 5) ;术后 2 8天上述值分别为(1 61± 0 3 5) %比 (3 1 1± 0 51 ) %(P <0 0 5)和 (1 61± 0 3 5) %比 (7 0 5± 1 82 ) %(P <0 0 5) ;2 8天时 2 0Gy组的内膜SMC凋亡明显高于 1 0Gy组 (7 0 5± 1 82 ) %比 (3 1 1± 0 51 ) %(P <0 0 5)。相同的放射剂量时 ,2 8天宰杀猪的髂动脉SMC凋亡高于 1 0天宰杀猪的量。结论 :血管内γ射线照射能抑制小型猪球囊损伤髂动脉内膜SMC增殖和刺激SMC凋     

普罗布考对兔血管成形术后再狭窄及血管生长因子的影响

目的 :研究普罗布考 (Probucol)对兔血管成形术后再狭窄的预防作用和对生长因子表达的影响。方法 :雄性新西兰白兔2 0只 ,随机分为对照组 (C组 ) 1 0只 ,Probucol组 (P组 ) 1 0只 ,于高脂饮食 1周后行髂动脉球囊拉伤术 ,术后 C组单纯予高脂饮食喂养 ,P组予 Probucol每只 1 0 0 0 m g/ d喂养 ,各组均给予 4周药物。于实验第 1、8、2 1、35天行血脂检查 ,术后 4周行血管形态学检查及检测胰岛素样生长因子 - I受体 (IGF- IR)、血管内皮生长因子 (VEGF)、增殖细胞核抗原 (PCNA)。结果 :两组间各时点血脂浓度差异无统计学意义。与 C组相比 ,P组管腔面积明显扩大 (P <0 .0 1 ) ,内膜 +中膜面积明显减少 (P <0 .0 5 ) ,IGF- IR、VEGF和 PCNA表达明显减少 (P <0 .0 1 )。结论 :Probucol可以显著减轻兔血管成形术后再狭窄的形成 ,抑制 IGF-IR、VEGF和 PCNA的表达     

左旋精氨酸对家兔髂动脉球囊损伤后PCNA的表达的影响

目的　探讨动脉球囊损伤后 ,左旋精氨酸抑制内膜增生的机制。方法　 36只健康家兔随机分成球囊损伤组(A组 ,n =12 )、球囊损伤 +L -Arg组 (B组 ,n =12 )、假手术组 (S组 ,n =12 ) ;每组再随机分成术后 7天处死和术后 2 8天处死两个亚组 (n =6 )。A、B组行右髂动脉球囊损伤术。B组从术前 3天至处死时经静脉注射L -Arg 95 0mg·Kg-1·d-1。组织切片行PCNA免疫组化染色 ,行形态学观察及形态计量分析。结果　A、B、S组皆有PCNA表达 ,A7组较B7、S组PCNA阳性细胞数、阳性百分率、增殖指数显著增高 (P <0 .0 5 )。结论　应用L -Arg可抑制动脉球囊损伤后内膜的增生 ,其作用的机制可能与L -Arg能抑制动脉壁细胞PCNA表达有关。     

全反式维甲酸对球囊损伤大鼠胸主动脉VSMC表型变化及增殖的影响

①目的探讨全反式维甲酸(ATRA)对球囊剥脱大鼠胸主动脉内皮后血管平滑肌细胞(VSMC)表型变化及增殖的影响。②方法雄性SD大鼠54只,随机分为3组。ATRA治疗组(n=24)行球囊剥脱大鼠胸主动脉内皮术,术前4d开始予ATRA芝麻油混悬液(30mg.kg-1.d-1)灌胃至术后处死;手术组(n=24)行球囊剥脱大鼠胸主动脉内皮术,术前4d开始予芝麻油(1mL.kg-1.d-1)灌胃至术后处死;对照组(n=6)除不插入球囊导管外,其他操作同手术组。分别于术后2、7、14、28d取胸主动脉应用苏木精-伊红染色、免疫组化和计算机图像分析法进行形态学、平滑肌α肌动蛋白(SM--αactin)和增殖细胞核抗原(PCNA)表达水平检测。③结果正常动脉VSMC高表达SM--αactin,处于非增殖状态;损伤后中膜SM--αactin表达迅速下降,2d达最低水平,而增殖旺盛,后趋向正常水平;新生内膜在术后7d出现,处于高度增殖状态,SM--αactin含量少,术后14、28d的SM--αactin表达明显增多,而增殖下降。ATRA治疗能明显抑制中膜SM--αactin的下调,诱导内膜和中膜SM--αactin表达,显著抑制VSMC的迁移和增殖,明显抑制新生内膜形成和管腔缩窄。SM--αactin表达与PCNA表达呈显著负相关(r=-0.738,P<0.01)。④结论维持并诱导VSMC于较高的分化状态,抑制VSMC迁移和增殖,是ATRA抑制球囊损伤大鼠主动脉后新生内膜增生和管腔狭窄的可能机制之一。     

雷红冲剂对兔动脉球囊损伤术后狭窄影响的实验研究

目的探讨雷红冲剂对兔动脉球囊损伤术后狭窄的干预作用。方法健康新西兰大白兔40只,随机分为假手术组、模型组、雷红冲剂低剂量组、雷红冲剂高剂量组,每组10只。运用球囊原位扩张、拉伤致兔髂动脉损伤建立经皮冠状动脉腔内血管成形术(PTCA)后内皮损伤模型。观察雷红冲剂对损伤血管内膜及管腔内径的影响。结果球囊损伤侧血管均显示弥漫性内膜增厚,光镜下形态学观察增生内膜以增殖的梭形平滑肌细胞为主。与假手术组比较,模型组管腔面积明显缩小(P<0.001),内膜、中膜显著增生(P<0.001);与模型组比较,雷红冲剂低、高剂量组管腔面积及内膜增生程度均明显改善(P<0.001),两组比较高剂量组优于低剂量组。与模型组比较雷红方对增殖细胞核抗原(PCNA)、血管内皮生长因子(VEGF)、细胞周期蛋白依赖性激酶2(CDK2)表达有减少的趋势(P<0.01),对细胞周期调控蛋白(p21cip1)表达有升高趋势(P<0.01)。结论雷红冲剂可抑制损伤血管的内膜增生,对兔髂动脉球囊损伤术后狭窄有不同程度的抑制作用。     

普罗布考和科素亚对血管成形术后生长因子表达的影响

目的 :研究普罗布考和科素亚对血管成形术后再狭窄的预防作用和对生长因子表达的影响。方法 :新西兰白兔30只均予高脂饮食 ,1周后进行髂动脉球囊拉伤术 ,随机分为对照组 (C组 )、普罗布考组 (P组 )、科素亚组 (L组 )。术后第 4周进行血管形态学检查 ,用免疫组化方法检测胰岛素样生长因子 - 1受体 (IGF- 1 R)、血管内皮生长因子(VEGF)、增殖细胞核抗原 (PCNA)表达。结果 :与 C组相比 ,P组和 L 组血管腔面积明显扩大 (P<0 .0 1 ) ,IGF- 1 R、VEGF和 PCNA表达明显减少 (P<0 .0 1 ) ,P组和 L组相比无显著性差异 (P>0 .0 5 )。结论 :普罗布考和科素亚可以显著减轻兔髂动脉血管成形术后再狭窄的形成 ,抑制 IGF- 1、VEGF和 PCNA的表达 ,而两药之间则无显著性差异     

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.