纳络酮预处理对脑出血大鼠脑组织水通道蛋白4及基质金属蛋白酶9表达的影响

目的 探讨纳络酮预处理对脑出血大鼠的保护效应及相关作用机制.方法 将30只雄性Sprague-Dawley大鼠(体质量280～350 g)按随机数字表法随机分为假手术对照组(Sham组)、脑出血(intracerebral hemorrhage,ICH)组和纳络酮预处理(Naloxone preconditioning,NP)组,每组10只大鼠.复制上述动物模型之前,NP组大鼠预先给予盐酸纳络酮(2.0 mg/kg),ICH组给予相同体积的生理盐水,随后制备ICH模型.切取并收集大鼠脑出血灶周围脑组织,分别采用RT-PCR和Western blot检测大鼠病变脑组织中水通道蛋白(aquaporin protein 4,AQP4)在转录水平和蛋白水平上的变化情况;同时采用免疫组织化学检测大鼠病变脑组织中基质金属蛋白酶(matrix metalloproteinase 9,MMP-9)的阳性表达情况.结果 相对于Sham组,ICH组大鼠脑组织中含水量明显增加(P<0.05),而经过纳络酮预处理后,大鼠脑组织中含水量明显减少(P<0.05);相对于ICH组,NP可有效降低脑出血大鼠脑组织中AQP4 mRNA和蛋白水平(P<0.01);同时,NP组大鼠脑组织中MMP-9阳性表达率明显下调(P<0.01).结论 纳络酮作为脑出血的一种有效的保护措施,其具体作用机制可能与其降低脑组织中AQP4的表达,从而减少脑水肿的发生及下调的MMP-9水平密切相关.     

曲马多对切口痛诱发大鼠脊髓背角神经元c-fos基因和血液IL-6表达的抑制作用

目的:在大鼠切口痛模型中研究腹腔注射曲马多对脊髓c-fos蛋白表达和血液IL-6含量的影响.方法:雄性SD大鼠48只,随机分为6组,每组8只,分别为假手术组、切口痛组、术前3个浓度曲马多预处理组(剂量分别为1 mg/kg、10 mg/kg、20 mg/kg)和术后曲马多治疗组(剂量为10 mg/kg).按Brennan法制成大鼠切口痛模型,以von Frey细丝法(机械性痛觉过敏)、热辐射法(热痛觉过敏)和累积疼痛评分法观察疼痛的行为学变化.手术后2 h取脊髓,并以免疫组织化学检测脊髓c-fos表达(Fos蛋白,以FLI阳性神经元表示),ELISA法测定血清IL-6含量.结果:与假手术组比较,在术后2 h时切口痛组大鼠的von Frey纤毛刺激缩爪阈值明显降低(P<0.01),热刺激缩爪潜伏期明显缩短(P<0.01),累积疼痛评分明显升高(P<0.01);与切口痛组比较,曲马多预处理10 mg/kg和20 mg/kg组大鼠的von Frey纤毛刺激缩爪阚值均明显增加(P<0.01),热刺激缩爪潜伏期均明显延长(P<0.01),累积疼痛评分均明显降低(P<0.01),此效应呈剂量依赖性;PT10组大鼠的行为学改变与T10组相似.切口痛组FLI细胞主要分布在Ⅰ～Ⅱ层,曲马多预处理10 mg/kg和20 mg/kg组FLI细胞与切口痛组相比减少.与假手术组比较,切口痛组大鼠脊髓c-fos表达和血液IL-6含量明显增加(P<0.01);与切口痛组比较,曲马多预处理10 mg/kg和20 mg/kg组能使脊髓c-fos表达和血液IL-6含量明显降低(P<0.01),此效应呈剂量依赖性,而术后曲马多治疗组这种抑制作用弱于曲马多预处理10 mg/kg组(P<0.05).与切口痛组比较,曲马多预处理1 mg/kg组的痛阈和脊髓c-fos表达以及血液IL-6含量差异无显著性意义(P>0.05).结论:曲马多能对疼痛引起的脊髓灰质背角FLI阳性神经元增多和血液IL-6含量增加的效应产生剂量依赖性的抑制作用,曲马多预处理效果更强;脊髓灰质背角Ⅰ～Ⅱ层可能是曲马多产生痛觉调制的主要部位.在大鼠切口痛模型中,曲马多的抗伤害作用可能与抑制脊髓c-fos的表达和减少血液IL-6含量有关.     

育亨宾对异丙酚麻醉中大鼠海马去甲基肾上腺素释放的影响

目的:观察大鼠异丙酚麻醉与中枢神经系统海马去甲基肾上腺素(NA)的释放以及α2-NA受体抑制剂之间的相互关系,探讨中枢性NA机制在异丙酚麻醉中发生的作用. 方法:选择20只雄性SD大鼠, 随机分为A, B 2组,每组10只. A组:微量泵以10 mg/(kg·h), 60 mg/(kg·h)的速度依次各静注45 min,停止静注异丙酚直至动物清醒. B组在输注异丙酚的同时腹腔内注射育亨宾0.5 mg/kg , 余和A组相同. 采用微透析技术分别测定异丙酚麻醉前、中及苏醒期的大鼠海马区细胞外液的NA释放值. 结果:A组和B组,NA的释放在整个麻醉过程中的变化趋势有显著差异(P<0.05). 其中B组的NA的释放量在整个麻醉过程中的变化波动较大并呈升高的趋势,最高为(0.19±0.02) μg/15 min,最低为(0.13±0.03) μg/15 min;而A组NA的释放量在整个麻醉过程中的变化则较平稳,最高为(0.16±0.01) μg/15 min,最低(0.14±0.02) μg/15 min. 结论:异丙酚麻醉抑制海马区NA的释放,育亨宾可使此作用减弱.     

预先腹腔联合注射曲马多与对乙酰氨基酚部分抑制大鼠L5脊神经结扎后神经病理性疼痛的形成

目的神经病理性疼痛是由中枢或外周神经系统损伤或疾病引起的疼痛综合征,临床起因广泛,病理机制复杂,症状多样,常规的单一的药物治疗对神经病理性疼痛均无明显的效果。文中旨在观察腹腔预先联合注射曲马多与对乙酰氨基酚对大鼠L5脊神经结扎后神经病理性疼痛形成的影响。方法健康成年雄性SD大鼠150只,体重250～300 g,出生10～15周,制备成L5脊神经部分结扎神经病理性疼痛模型后随机分为5组(n=30):假手术组(S组)、等渗盐水对照组(C组)、曲马多20 mg/kg(T组)、对乙酰氨基酚160 mg/kg(P组)、曲马多20 mg/kg+对乙酰氨基酚160 mg/kg(T+P组),每组分别向腹腔注射相应药物,2次/d,并于手术当天及术后第1、3、7、11、14、21天,分别测定大鼠的机械性缩足反射阈值(mechani-cal withdrawal threshald,MWT)和热缩足潜伏期(thermal withdrawal lateney,TWL)值。结果L5脊神经损伤术后4组大鼠均出现明显的机械痛觉超敏和热痛觉过敏症状;与对照组相比,手术当天即开始连续给与曲马多+对乙酰氨基酚能预防性减轻疼痛行为学表现,以术后...     

姜黄素对神经病理性疼痛大鼠脊髓背角和背根神经节GR和NMDAR-NR1表达的影响

目的探讨姜黄素对神经病理性疼痛大鼠脊髓背角和背根神经节皮质激素受体(GR)和NMDAR-NR1表达的影响。方法将雄性SD大鼠72只(体质量220～250g),随机分成4组:假手术组(Sham组)、慢性坐骨神经结扎损伤组(CCI组)、CCI+溶剂组(SC组)、CCI+姜黄素100mg/kg组(Cur100组)。SC组和Cur100组大鼠在坐骨神经结扎后,分别腹腔注射溶剂或100mg.kg-1.d-1姜黄素,至术后14d。于术前2d和术后1、3、5、7、10、14d测定机械缩足反射阈值(MWT)和热缩足反射潜伏期(TWL);术后3、7、14d取大鼠术侧L4、L5脊髓背角和背根神经节,用免疫组化法检测脊髓背角和背根神经节GR和NMDAR-NR1表达情况。结果与Sham组相比,CCI组术后TWL、MWT明显降低(P<0.01),术侧脊髓背角和背根神经节内GR和NMDAR-NR1表达明显增多(P<0.01)。与CCI组相比,Cur100组大鼠TWL和MWT明显提高(P<0.05),脊髓背角和背根神经节GR和NMDAR-NR1表达明显减少(P<0.05)。结论姜黄素可通过抑制脊髓背角和背神经根节GR和NMDAR-NR1的表达而减轻CCI大鼠神经病理性疼痛。     

可乐定对小鼠和大鼠烧伤休克的保护作用

可乐定1mg/kg ip及0.2(小鼠)或0.025(大鼠)1ng/kg iv,可提高烫伤小鼠的存活率,延长烫伤大鼠的存活时间。育亨宾对抗其保护烫伤小鼠的作用,哌唑嗪无明显影响。可乐定在使烫伤大鼠颈交感神经放     

预防性给予重组人红细胞生成素对神经病理性疼痛大鼠的行为学影响

目的神经病理性疼痛难于治疗,探寻新的治疗药物是未来神经病理性疼痛治疗的重要研究方向。文中探讨雄性大鼠L5脊神经切断前预防性给予重组人红细胞生成素(Recombinant Human Erythropoietin,rhEPO)对大鼠机械、热痛觉高敏的影响及可能机制。方法选用L5脊神经切断神经病理性模型,将50只SD雄性大鼠随机分成5组(每组10只),分别为:假手术组、损伤腹腔注射等渗盐水组(等渗盐水组)、损伤腹腔注射rhEPO 1000 U/kg组(rhEPO 1000 U/kg组)、损伤腹腔注射rhEPO 3000 U/kg组(rhEPO 3000 U/kg组)、损伤腹腔注射rhEPO 5000 U/kg组(rhEPO 5000 U/kg组),术前1 d给药,连续给药7 d。采用von Frey和Hargreaves法测定各组大鼠机械缩足反射阈(mechnical withdrawal threstholds,MWT)值和热缩足潜伏期(thermal withdrawal latencies,TWL)。结果与等渗盐水组大鼠相比,预防性腹腔注射rhEPO 3000 U/kg或5000 U/kg,能明显缓解大鼠的机械、热痛高敏行为。结论预防性给予rhEPO(3000 U/kg或5000 U/kg)能预防神经病理性疼痛的发生。     

大剂量白蛋白联合纳络酮治疗重度新生儿缺氧缺血性脑病疗效观察

目的探讨大剂量白蛋白联合纳络酮治疗重度新生儿缺氧缺血性脑病(HIE)的临床疗效。方法选择重度HIE患儿72例,分为3组:大剂量白蛋白与纳络酮(白蛋白 纳络酮)治疗组24例,给予静脉滴注人体白蛋白2 g/(kg.d),连续3~5 d,纳络酮0.1 mg/kg加10%葡萄糖20 ml,2 h滴完,每8 h 1次,连续3 d;大剂量白蛋白治疗组24例,静滴人体白蛋白2 g/(kg.d),连续3~5 d;对照治疗组24例。观察3组患儿临床症状体征变化,同时进行新生儿神经行为(NBNA)评分。结果大剂量白蛋白可显著提高重度HIE 2周后NBNA评分(P<0.05),与纳络酮联合治疗重度HIE,临床症状体征早期明显好转,NBNA评分进一步提高,与对照组相比差异显著(P<0.01)。结论大剂量白蛋白联合纳络酮治疗重度HIE疗效显著,预后改善。     

川芎嗪对轻度烧伤大鼠烧伤痛行为学影响研究

目的 探讨川芎嗪对轻度烧伤大鼠痛行为的影响,了解川芎嗪对烧伤痛的作用.方法 建立大鼠轻度烧伤模型,应用von Frey细丝法和热辐射法测定机械缩足反射阈值(mechanical withdrawal threshold,MWT)和热缩足反射潜伏期( thermal withdrawal latency,TWL),观察川芎嗪对烧伤大鼠MWT和TWL的影响.结果 烧伤后1 h,ⅢA组(生理盐水+Ⅰ度烧伤组)和ⅢB组(生理盐水+浅Ⅱ度烧伤组)MWT和TWL显著性下降,分别持续24 h和96 h(P<0.01).24 h之后,ⅡA组(TMP+Ⅰ度烧伤组)TWL和TWL和Ⅰ组相比无显著性差异,而ⅡB组(TMP+浅Ⅱ度烧伤组)24 h后明显增加,72 h后与Ⅰ组相比已没有显著性差异.结论 川芎嗪可以抑制烧伤大鼠的机械缩足反射阈值和热缩足反射潜伏期,从而对烧伤痛有抑制作用.     

苦参碱对大鼠急性心肌缺血性损伤的保护作用

目的 研究苦参碱对大鼠急性心肌缺血性损伤的保护作用.方法 将SD大鼠随机分为7组:正常对照组、假手术组、模型组、硝酸甘油组、苦参碱2.5、5、10mg/kg剂量组.应用左冠状动脉前降支(LAD)结扎法制备大鼠急性心肌缺血模型.记录结扎前、结扎后1、5、15、30、60min大鼠心率(HR)、平均动脉血压(MAP);应用分光光度计法检测血清中肌酸激酶(CK)活性和一氧化氮(NO)含量.结果 静脉注射苦参碱5、10ms/ks均可使大鼠HR、MAP明显升高(P<0.05或P<0.01),此作用在左冠状动脉前降支结扎后15min最明显.静脉注射苦参碱5、10mg/kg,可降低急性心肌缺血大鼠血清CK活性(P<0.05或P<0.01);静脉注射苦参碱2.5、5、10mg/kg,可增加急性心肌缺血大鼠血清NO含量(P<0.05或P<0.01).结论 静脉注射苦参碱对大鼠急性心肌缺血性损伤有保护作用.     

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.