异基因造血干细胞移植后供者淋巴细胞输注观察与护理

目的探讨血液病异基因造血干细胞移植后供者淋巴细胞输注（DLI）的并发症的观察及护理。以确保DLI的安全性及疗效。方法对11例血液病畀基因造血千细胞移植后,进行DLI。其中5种肿瘤性血液病在非清髓性移植后形成混合性嵌合体（MC）状态后,逐渐增加输注供者的T细胞剂量方案进行DLI。首次于移植后4。5周进行第一次Du,此后在无aGVHD情况下,每隔3—4周进行1次。6例血液病包括2例SAA、1例TM、1例cML（CP1）、急性白血病2例,经过G-CSF动员后行供者淋巴细胞输注。供者分离血量4000—10000ml,观察输注时尿常规,患者的反应情况,输注后血象、骨髓象,嵌合体情况及GVHD发生情况。结果输注过程仅有轻微血红蛋白尿。出现Ⅰ～Ⅱ急性移植物抗宿主病（aGVrm）3例、慢性GVHD（cGVHD）3例、骨髓抑制2例。结论无论血型相舍与否,DLI过程安全,GVHD和骨髓抑制为其主要两大并发症。     

急性髓系白血病异体造血干细胞移植后复发12例分析

目的 探讨急性髓系白血病（AML）异体造血干细胞移植（allo-HSCT）后复发的临床特点及危险因素。方法 收集2012年1月至2021年1月于中国医科大学附属第一医院血液科接受allo-HSCT后复发的12例AML病例,统计其临床一般信息、造血干细胞移植情况、复发后治疗情况以及随访结果等。结果 12例患者造血干细胞均成功植活,其中8例血液学复发,复发中位时间4个月;4例分子生物学复发,复发中位时间4.5个月。8例血液学复发患者无一例发生急性及慢性移植物抗宿主病（a/cGVHD）,其中4例患者于复发后行化疗+供者淋巴细胞输注（DLI）治疗,1例行二次同供者allo-HSCT,另外3例患者复发后放弃治疗,最终8例患者均不同时间死亡。4例分子生物学复发患者中,1例快速减停免疫抑制剂后出现cGVHD,已持续缓解6年;3例予以地西他滨+DLI治疗,其中1例出现aGVHD,截至目前已持续缓解3年,1例无GVHD,已持续缓解2年,1例出现aGVHD,持续缓解近3个月,最终死于重症感染。结论 无论接受全相合或半相合allo-HSCT的AML患者,血液学复发前通常无GVHD,化疗+DLI治疗效果差,无...     

非清髓异基因造血干细胞移植造血细胞嵌合体形成及演变的临床意义

目的：探讨非清髓异基因造血干细胞移植（NAST）造血细胞嵌合体的形成及演变的临床意义。方法：采用非清髓性预处理方案治疗了42例组织相容性抗原相合的血液病患者。男26例,女16例,中位数年龄37岁（18－59岁）。非清髓预处理：白血病患者采用环磷酰胺（CTX）、阿糖胞苷及CD3单克隆抗体,6周患者在此基础上加用氟达拉滨。再生障碍性贫血和骨髓增生异常综合征患者采用CTX和抗淋巴细胞球蛋白。结果：42例患者均顺利渡过造血抑制期并形成造血细胞嵌合体。18例形成稳定的完全供者造血细胞嵌合体（FDC）,24例形成混合造血细胞嵌合体（MC）。其中15例逐渐转为FDC,5例保持稳定嵌合状态,4例发生移植排斥。42例中10例（23．8％）发生急性移植物抗宿主病（aGVHD).其中FDC者8／18（44．4％）,MC组2／24,FDC者的aGVHD发生率明显高于MC患者（P＜0．05）。42例中8例发生慢性移植物抗宿主病（cGVHD).FDC者4／18,MC者4／24,FDC患者的cGVHD发生率高于MC组但差异无显著意义（P＞0．05）。FDC患者和MC患者的中性粒细胞和血小板最低值及恢复时间,存活时间差异无显著意义（P＞0．05）。随访2－43个月,仍存活31例（73．8％）。结论：NAST早期先形成高比例MC再逐渐转化为FDC即可显著减轻GVHD又不降低和影响疗效,可能是造血干细胞移植更理想的植入模式。     

非清髓造血干细胞移植治疗重型再生障碍性贫血

目的探讨非清髓造血干细胞移植治疗重型再生障碍性贫血（Severe alpastic anemia,SAA）的方法及疗效。方法对5例确诊的SAA患者进行了全相合的造血干细胞移植（Hematopoietic stem cell transplantation,HSCT）,预处理方案为：环磷酰胺（Cyclophosphamide,CY）＋氟达拉滨（Fludarabine,FLU）＋抗人胸腺球蛋白（Antithymocyte globulin,ATG）。观察采用该方案的非清髓预处理后患者造血重建时间及疗效。结果 5例患者移植后第10-14d供者造血重建,第30d行患者骨髓人类短串联重复序列复合扩增（Short tadom repeated-PCR,STR-PCR）检测显示为完全供者的基因型。其中1例出现I度急性移植物抗宿主病（Acute graft-versus-host disease,a GVHD）,2例口腔黏膜感染,1例肺部感染,随访至移植后3-28个月,造血功能恢复良好。结论以CY＋FLU＋ATG的非清髓性预处理方案造血干细胞移植治疗SAA,能够获得稳定的植入,且并发症少,是有效移植方法。     

异基因造血干细胞移植治疗急性髓系白血病4例效果分析

目的：回顾性分析急性髓系白血病异基因造血干细胞移植的临床疗效。方法：急性髓系白血病患者4例,采用粒细胞集落刺激因子动员外周血干细胞,其中3例行全相合异基因移植,1例行半相合异基因移植。结果：4例患者均获得造血重建,呈完全嵌合体状态,粒细胞中位植活时间为11（11～12）ｄ,血小板中位植活时间为12.5（11～13）ｄ。2例出现aGVHD,其中Ⅰ度1例,Ⅳ度1例;2例出现cGVHD,1例为局限性,1例为Ⅳ度肠、肝cGVHD;1例出现消化道粘膜炎,1例出现轻度肝功能损害,2例EB病毒定量升高,治疗后均好转。结论：异基因造血干细胞移植治疗AML疗效显著,使用外周血干细胞进行半相合移植值得推广。     

非清髓性异基因外周血造血干细胞移植治疗慢性粒细胞白血病

目的　探讨非清髓性异基因外周血造血干细胞移植 (非清髓性allo -PBSCT)治疗慢性粒细胞白血病的治疗效果。方法　对 4例白血病患者进行了非清髓性allo -PBSCT治疗并进行了临床观察。结果　 4例均成功植入 (完全植入或混合嵌合性植入 ) ,1例出现IV°aGVHD ,存活 3个月后死于cGVHD及多脏器功能衰竭 ;另外 3例未出现严重移植并发症 ,1例10个月后失访 ,2例至今分别存活 10个月、2 3个月。结论　非清髓性allo -PBSCT是一种根治白血病更安全有效的方法     

减低预处理剂量的异基因造血干细胞移植治疗难治性急性白血病

目的 探讨减低预处理剂量的异基因造血干细胞移植在难治性急性白血病治疗中的安全性和疗效.方法 6例难治性急性白血病,其中5例耐药复发,1例继发性白血病,经常规化疗2～11个疗程未能达到完全缓解.预处理方案为减低预处理剂量的BuCy方案.结果 除1例死于肠道Ⅳ度急性GVHD外,其余5例均获得造血重建,各脏器预处理相关毒性（RRT）大多数为Ⅰ～Ⅱ级,未发生严重预处理相关并发症.移植后11～24 d均有经DNA检测证实的完全供者嵌合.发生急性GVHD 4例,2例为Ⅳ度肠道GVHD,分别于＋18 d和＋64d死亡.1例为Ⅰ度皮肤GVHD治愈,1例先后出现Ⅳ度皮肤aGVHD和肝脏cGVHD经治疗得到良好控制,无白血病生存.3例移植后发生髓外软组织肿瘤（EMD）,采用联合化疗＋放疗、供者淋巴细胞输注（DLI）,2例进行了二次移植,2例无病生存,1例带瘤生存.结论 减低预处理剂量的BuCy方案治疗难治复发性急性白血病,有较好的耐受性,可取得完全型供者细胞植入及血液学缓解,但有可能增加髓外复发的风险.     

移植物抗宿主病的发生及其早期预测分析

目的 为了探讨异基因造血干细胞移植（allo-HSCT)后移植物抗宿主病(GVHD)及不明原因水肿与GVHD的关系及其临床意义。方法 对29例allo-HSCT的白血病惠者进行了随访观察；将发生急性GVHD(aGVHD)或慢性GVHD(cGVHD)前有无水肿的病例分为水肿组与非水肿组进行对比分析。结果 29例病人均顺利植入，15例中17例次发生GVHD，其中8例aGVHD，7例为Ⅰ、Ⅱ度，1例为肠道Ⅳ度aGVHD；9例(其中2例为aGVHD转变)cGVHD中，5／9例为局限性皮肤或口腔黏膜cGVHD，4／9例为广泛性皮肤cGVHD。17例次GVHD中，4例aGVHD和1例cGVHD患者，发生GVHD前均有不明原因的水肿，其部位为颜面及双下肢，其中4例为轻度一过性水肿，1例为中等度持续性水肿，发生时间为 23～ 150d。水肿与GVHD发生时的间隔时间为7～12d。所有病例随访15个月(3～106个月)，15例GVHD病人中，14例病情控制或稳定，仅1例Ⅳ度aGVHD死亡。结论 水肿与GVHD似乎有关联，特别是aGVHD。allo-PBSCT后不明原因的水肿可能为GVHD预测指征，防治GVHD有积极意义。     

造血干细胞移植治疗恶性血液病、实体瘤回顾分析

目的 探讨不同预处理方案以及不同移植方法治疗恶性血液病、实体瘤的疗效,对其移植效果及移植风险进行评价.方法 回顾分析非净化自体骨髓移植（auto-HSCT）31例,外周血干细胞加自体骨髓活化移植（PBSCT＋ABM）26例,清髓性异基因骨髓移植（allo-HSCH）18例,非清髓性异基因骨髓/外周血移植（allo-NSCT）43例,脐带血干细胞移植（CBT）7例的临床资料.PBSCT＋ABM、auto-HSCH和allo-HSCH均采用MAC方案预处理.PBSCT＋ABM系采用自身外周血干细胞及体外活化自体骨髓液750 ml回输;allo-HSCT采集供者骨髓液于移植0 d回输;allo-NSCT是采用低强度的FAAC或MAAC两种方案预处理,移植后根据嵌合体形成的情况,以递增方式将供体淋巴细胞输注（DLI）给患者.allo-CBT患儿,2例采用脐血库的干细胞,HLA配型4个以上的位点相合,5例采用同胞的脐带血干细胞,预处理采用CTX/ATG,移植的程序与上述一致.异基因移植患者常规使用免疫抑制剂（环胞霉素、氨甲蝶呤/骁悉）,并根据白细胞、血小板、骨髓恢复,ABO血型分析,STR测定嵌合体形成等情况作为植活的证据.aGVHD按Glucksberg标准分析,cGVHD根据Shulman标准分析.结果 125例患者中除有1例慢性髓性白血病（CML）NSCT移植后40 d时植入失败死于骨髓衰竭,1例急性髓性白血病（AML）NSCT在造血恢复前死于脑出血外,其余123例都预期恢复造血.异基因移植aGVHD发生率9.69%,cGVHD发生率22.23%.auto-HSCT31例,截止资料分析时生存8例（25.80%）.PBSCT＋ABM 26例,生存15例（57.69%），allo-HSCT 18例,生存11例（61.11%）,NSCT43例,生存19例（45%）.CBT7例生存2例.结论 异基因造血干细胞移植是一种根治性的治疗手段,尤其非清髓性预处理的异基因造血干细胞移植方法不仅扩大了移植的应用范围及适应证,而且提高了移植的安全性并降低了移植费用.     

造血干细胞移植治疗血液病及实体瘤的疗效分析

目的评价造血干细胞移植(HSCT)治疗血液病和实体瘤的临床疗效及并发症。方法回顾性分析61例行HSCT的患者,其中19例为自体造血干细胞移植(auto-HSCT),37例为异基因造血干细胞移植(allo-HSCT),5例非血缘脐血移植(UCBT)。结果除2例成人UCBT病例外,59例均获造血重建。在auto-HSCT、allo-HSCT(不包括UCBT病例)和UCBT后中性粒细胞绝对计数(ANC)≥0.5×109/L和血小板≥20×109/L所需的时间3组分别为(11.7±3.8)d和(12.7±5.4)d、(12.5±2.6)d和(13.8±4.3)d、(14.2±3.5)d和(30.4±10.5)d。auto-HSCT与allo-HSCT比较造血重建时间差异无显著性意义(P>0.05),但与UCBT组相比差异有极显著性意义(P<0.01)。allo-HSCT组急性移植物抗宿主病(aGVHD)发生率为24.3%,慢性移植物抗宿主病(cGVHD)发生率为35.1%,UCBT组未发生GVHD。auto-HSCT组、allo-HSCT组和UCBT组总生存率(OS),无病生存率(DFS)和累积复发率的Kaplan-Meier曲线无显著差异。auto-HSCT组中移植后免疫治疗组和非免疫治疗组的DFS及累积复发率的Kaplan-Meier曲线有显著差异。结论auto-HSCT与allo-HSCT的3年OS、DFS和复发率相当。auto-HSCT后的免疫治疗能有效降低复发率。非清髓造血干细胞移植(NST)对于有脏器功能受损或年龄大的患者是安全有效的,术后嵌合体的监测指导免疫抑制剂的调节和供者淋巴细胞输注(DLI)能有效预防复发。     

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.