七氟烷和异氟烷对肝脏缺血再灌注损伤的影响

 【目的】探讨七氟烷和异氟烷预处理对大鼠肝脏缺血再灌注损伤(I/R)的保护作用及机制。【方法】96只SD大鼠随机分为假手术对照组(Sham)、肝脏缺血再灌注组(IR)、七氟烷预处理(Sev)和异氟烷预处理组(Iso),于肝脏缺血30min,再灌注30min、120min测各组大鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)的含量以及肝脏组织中谷胱甘肽(GSH)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性。【结果】肝脏缺血再灌注后IR、Sev和Iso组血清ALT、AST和LDH含量均显著升高,肝组织SOD和GSH显著降低,而MDA明显升高,和Sham组相比有显著差异(P<0.01);Sev、Iso组和IR组比较,ALT、AST、LDH和MDA降低,而SOD和GSH显著升高(P<0.05或P<0.01),其中Sev组比Iso组效果更为明显(P<0.05或P<0.01)。【结论】七氟烷和异氟烷对肝脏缺血再灌注损伤有一定的保护作用,这可能与其抑制氧自由基生成,减少脂质过氧化有关。     

二氮嗪对黄疸大鼠肝脏缺血再灌注损伤的影响

目的：研究二氮嗪对梗阻性黄疸肝脏的缺血再灌注损伤是否有保护作用。方法：采用胆总管结扎法制作梗阻性黄疸模型，雄性S—D大鼠60只，分5组：缺血再灌注损伤组（对照组），缺血30min和再灌注120min；GSH活性氧（清除剂）处理组，缺血再灌注前10min静脉注射GSH50mg／kg；二氮嗪预处理组（A、B、C）缺血再灌注前10min分别静脉注射1mg／kg、5mg／kg、10mg／kg。结果：与对照组相比，二氮嗪预处理各组血清中ALT、AST、LDH含量，细胞内MDA含量和SOD活性，肝细胞凋亡指数差异无显著性（P〉0．05），而GSH组与对照组相比，各组血清中ALT、AST、LDH含量，细胞内MDA含量和SOD活性，肝细胞凋亡指数差别具有显著性（P〈0．05）。结论：二氮嗪预处理对大鼠梗阻性黄疸肝脏缺血30min再灌注120min无保护作用，GSH预处理对大鼠梗阻性黄疸肝脏缺血再灌注损伤能／提供保护作用。     

心钠素预处理对大鼠肝脏缺血再灌注损伤的影响

目的：探讨心钠素（ANP）预处理对肝脏缺血再灌注损伤的影响。方法：30只雄性SD大鼠随机均分为3组：假手术组（SO组）、缺血再灌注组（IR组）和ANP预处理组。IR组和ANP预处理组分别经门静脉注入生理盐水、1mg/L的ANP3mL/kg,然后阻断左、中叶肝蒂45min,造成70%肝脏缺血,SO组仅行分离而不阻断,再恢复供血40min,采集下腔静脉血测定血清谷丙转氨酶（ALT）、谷草转氨酶（AST）、乳酸脱氢酶（LDH）水平,取肝组织测定超氧化物歧化酶（SOD）与丙二醛（MDA）水平,并行肝组织病理学观察。结果：IR组和ANP预处理组缺血再灌注后血清ALT、AST、LDH水平及肝组织MDA含量均高于SO组,肝组织SOD含量低于SO组;ANP预处理组血清ALT、AST、LDH水平及肝组织MDA含量低于IR组,肝组织SOD含量则高于IR组;ANP预处理组肝细胞形态学异常改变较IR组明显减轻。结论：ANP预处理可减轻大鼠肝脏缺血再灌注损伤,其机制可能与提高肝组织SOD含量,抑制脂质过氧化,保护线粒体有关。     

异氟烷对大鼠肝脏缺血再灌注损伤时细胞间黏附分子-1表达的影响

目的研究异氟烷对大鼠肝脏缺血再灌注损伤后细胞间黏附分子-1（ICAM-1）的影响,探讨异氟烷肝脏缺血再灌注保护作用的机制。方法将32只SD成年雌性大鼠分为假手术组、缺血再灌注组、异氟烷组、异氟烷．缺血再灌注组。假手术组、异氟烷组作为对照;缺血再灌注组和异氟烷-缺血再灌注组阻断支配大鼠肝脏左叶和中叶的门静脉分支,建立肝脏70％缺血再灌注模型,缺血60min再灌注3h后取材,测定大鼠血清ALT、AST;免疫组织化学方法检测ICAM-1蛋白的表达,HE染色进行病理学检查。结果肝脏缺血60min再灌注3h后肝组织ICAM-1蛋白表达水平增高;血清酶ALT和AST升高;肝组织损害严重。异氟烷抑制ICAM-1表达,降低ALT、AST水平,减轻肝细胞损伤。结论肝脏缺血再灌注损伤程度与肝组织内ICAM-1水平有密切的关系,异氟烷可抑制肝脏缺血再灌注期间肝组织ICAM-1的表达,同时减轻伤肝脏损伤。     

缺血预处理对肝硬化大鼠肝缺血再灌注损伤保护作用的实验研究

目的 观察缺血预处理对肝脏缺血再灌注损伤的保护作用。方法 建立肝硬化大鼠模型,测定肝脏缺血预处理组与对照组血天冬氨酸氨基转移酶（AST）、血丙氨酸氨基转移酶（ALT）、乳酸脱氢酶（LDH）及肝组织中丙二醛（MDA）、超氧化物歧化酶（SOD）、谷胱甘肽还原酶（GSH-PX）及ATP含量。结果 预处理组与对照组相比缺因再灌注后AST、ALT、LDH升高较少,MDA含量较低,SOD、GSH-PX含量较高,ATP储量较高。结论 缺血预处理能有效减轻肝硬化大鼠肝脏的缺血再灌注损伤。     

血红素氧化酶-1在异氟烷预处理肝脏保护机制中的作用

目的 研究血红素氧化酶(HO)-1的表达及活性的改变对肝脏缺血再灌注损伤的影响,及其在异氟烷预处理肝脏保护中的作用.方法 将40只雄性Sprague-Dawley大鼠随机均分为5组:假手术(Sham)组;肝脏缺血再灌注对照组(I/R组).肝脏缺血60 min,再灌注4 h;异氟烷预处理一肝脏缺血再灌注(I/R-ISO)组,1.4%异氟烷吸入预处理30 min后再行缺血再灌注处理;肝脏缺血再灌注组-异氟烷预处理-HO-1抑制剂(Iso-Znpp)组.于缺血再灌注前1 h先于腹腔内注射锌原卟啉(ZnPP),其余处理同I/R-ISO组;肝脏缺血再灌注HO-1诱导剂(I/R-hemin)组,缺血再灌注前24 h于腹腔内注射HO-1诱导剂血红索(hemin),其余处理同I/R组.观察各组大鼠肝组织的病理改变,测定血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、肝脏髓过氧化物酶(MPO)活性,以及肝组织及血清肿瘤坏死因子(TNF)-а的表达等情况.采用免疫组织化学方法测定HO-1的表达.结果 与I/R组比较,I/R-ISO和I/R-hemin组的ALT、AST水平均显著降低(P值均＜0.05);与I/R-ISO组比较,Iso-Znpp组ALT、AST均显著升高(P值均＜0.05).与Sham组比较,I/R、I/R-ISO、Iso-Znpp、I/R-hemin组血清及肝组织中TNF-а mRNA水平均显著升高(P值均＜0.05);与I/R组比较,I/R-ISO和I/R-hemin组血清及肝组织中TNF-а mRMA水平均显著降低(P值均＜0.05);与I/R-ISO组比较,Iso-Znpp组血清及肝组织中TNF-а水平均显著升高(P值均＜0.05).与Sham组比较.I/R、I/R-ISO、Iso-Znpp、I/R-hemin组肝脏MPO活性均显著升高(P值均＜0.01);与I/R-ISO组比较,Iso-Znpp组肝脏MPO活性显著升高(P＜0.05).Sham组几乎无HO-1表达,I/R组可见HO-1少量表达,I/R-ISO、ISO-Znpp、I/R-hemin组HO-1表达均显著高于I/R组.结论 HO-1的诱导表达可明显减轻肝脏缺血再灌注损伤和相应的炎性反应,异氟烷预处理可明显上调肝脏缺血再灌注损伤后HO-1的表达,HO-1活性抑制剂ZnPP可反转异氟烷预处理的肝脏保护及抗炎作用,提示异氟烷预处理的肝脏保护及抗炎作用可能与增强肝脏缺血再灌注后肝脏中HO-1的表达及活性有关.     

缺血预处理对大鼠肝缺血再灌注肾损伤的影响

【目的】探讨缺血预处理对大鼠肝缺血再灌注肾损伤的影响及可能机制。【方法】30只SD大鼠,随机分为假手术对照组(Sham组)、肝缺血再灌注组(IR组)和缺血预处理组(IPC组),每组10例。Sham组仅分离肝门区;IR组用无损伤血管夹夹闭门静脉和肝动脉的分支,阻断肝左、中叶血流,缺血40 min,再灌注6 h;IPC组先缺血5 min,再灌注5 min,然后操作同IR组。肝缺血再灌注6 h,断头处死大鼠,于下腔静脉抽取血样并取左肾和左肝。血样离心测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、尿素氮(BUN)和肌酐(Cr)的含量。左肾一半制成匀浆,测定肾组织匀浆超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6)的含量,另一半和左肝观察组织病理改变。【结果】与Sham组比较,IR组和IPC组ALT、AST、BUN、Cr、MDA、TNF-α和IL-6含量升高,SOD含量降低(P<0.05),肾组织病理损伤明显;与IR组比较,IPC组ALT、AST、BUN、Cr、MDA、TNF-α和IL-6含量降低,SOD含量升高(P<0.05),肾组织病理损伤减轻。【结论】缺血预处理对肝缺血再灌注导致的肾损伤有保护作用,其保护机制可能与减少氧自由基的释放和抑制炎症反应有关。     

丙泊酚-瑞芬太尼靶控静脉麻醉对肝脏缺血再灌注损伤的保护作用

目的探讨丙泊酚．瑞芬太尼靶控静脉麻醉对肝脏部分切除术缺血再灌注损伤的影响。方法40例患者随机分为丙泊酚-瑞芬太尼组和异氟烷组。分别于术前（TO）、麻醉诱导后（T1）、肝门阻断开放后10min（T2）、30min（T3）和60min（T4）取静脉血测定谷草转氨酶（AST）、谷丙转氨瞬（ALT）、谷氟酰转肽酶、总胆红素等代谢指标，并测定血清总超氧化物歧化酶（T-SOD））和丙二醛（MDA）含量。结果两组的AST和ALT在肝门开放后10、30、60min均逐渐增高．与术前比较差异均有统计学意义（P〈0．05）；丙泊酚-瑞芬太尼组的AST在T4明显高于异氟烷纽（P〈0．05）。两组SOD在肝门开放后10、30、60min逐渐降低，1’3和T4时与术前比较差异均有统计学意义（P〈0．05），在13和T4时异氟烷组的SOD明显低于丙泊酚一瑞芬太尼组（P〈0．05）。丙泊酚一瑞芬太尼组的MDA各时间点无显著变化，异氟烷组的MDA在13和T4时均较术前增高，同时明显高于丙泊酚．瑞芬太尼组（P〈0．05）。结论丙泊酚．瑞芬太尼麻醉对肝脏缺血再灌注损伤后超氧化物歧化酶和丙二醛的影响变化较小，提示其对肝细胞具有较好的保护作用。     

七氟烷预处理对大鼠在体心肌抗氧化的影响

目的探讨七氟烷预处理对大鼠心肌抗氧化作用。方法 50只健康雄性SD大鼠分为5组：假手术组（C组）、缺血再灌注组（I/R组）、1%、2%、3%七氟烷预处理组（S1组、S2组、S3组）,每组10只,建立大鼠在体心肌缺血再灌注模型。测定再灌注3h后血清MDA、SOD和CK-MB含量。结果 S1、S2、S3组的MDA、CK-MB积明显低于I/P组,且S2组的MDA和CK-MB的水平低于S1、S3组,SOD水平明显高于I/P组（P〈0.01）。结论在心肌缺血再灌注损伤中,七氟烷对心肌的具有保护作用,且浓度为2%的七氟烷保护作用较好。     

七氟烷对肾脏缺血/再灌注糖尿病大鼠肝功能的影响

目的 探讨吸入性麻醉药七氟烷对糖尿病大鼠肾脏缺血/再灌注后肝功能的保护作用.方法 雄性SD大鼠随机分为6组:正常大鼠组;大鼠肾脏缺血/再灌注组;七氟烷预处理大鼠肾脏缺血/再灌注组;糖尿病大鼠组;糖尿病大鼠肾脏缺血/再灌注组;七氟烷预处理糖尿病大鼠肾脏缺血/再灌注组.测定各组大鼠血液谷丙转氨酶(ALT)、谷草转氨酶(AST)值,对测得数据采用SPSS13.0软件进行统计学处理.结果糖尿病大鼠肾脏缺血/再灌注组分别较正常大鼠及糖尿病大鼠组ALT、AST有所升高,差异无显著性;七氟烷预处理后肾脏缺血/再灌注组较肾脏缺血/再灌注组ALT、AST进一步升高(P值分别为0.527及0.141),差异无显著性;糖尿病大鼠七氟烷预处理后肾脏缺血/再灌注组较糖尿病大鼠肾脏缺血/再灌注组ALT进一步升高,AST略降低,差异无显著性.结论 2.5%七氟烷预处理对糖尿病大鼠肾脏缺血/再灌注肝功能损伤无明显保护作用.     

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.