DNA损伤修复基因XRCC4、RAD51单核苷酸多态性与中国地区食管癌易感相关性研究

目的 探究DNA双链断裂修复基因XRCC4、RAD51单核苷酸多态性与食管癌易感性的关系。 方法 采用以医院为基础的病例-对照研究方法,应用PCR限制性内切酶片段长度多态性(PCR-RFLP)检测包括正常对照61例,食管癌患者123例XRCC4基因启动子区G-1394T(rs6869366)位点,以及RAD51-G135C位点的单核苷酸多态性。通过logistic回归分析计算出比值比(OR)和95%置信区间(95%CI)。 结果 XRCC4 rs6869366位点G等位基因的基因型(GT+GG)的携带者患食管癌的风险显著增加(OR=3.022,95%CI=1.487~6.142,P=0.002)。RAD51基因型GC和CC与携带GG的野生型个体相比,携带RAD51变异基因型(GC和CC)的个体具有更高的患癌风险(OR=3.643,95%CI=1.501~8.842,P<0.05)。 结论 DNA损伤修复系统中的基因多态性很可能与食管癌发生的易感性有关,XRCC4 G-1394T,RAD51-G135 C位点多态性改变均可增加食管癌的发病风险。     

苏皖地区汉族人群XRCC4 rs6869366多态性与前列腺癌易感性的关系

目的:研究中国苏皖地区汉族人群X 线修复交叉互补组4(XRCC4) rs6869366多态性与前列腺癌(prostate cancer,PCa)易感性的关系?方法:采用病例-对照研究,提取187例PCa患者(病例组)和210例非肿瘤患者(对照组)外周血基因组DNA,应用聚合酶链反应-连接酶特异检测技术(polymorphism chian reaction and ligase detection reaction,PCR-LDR)分析两组XRCC4 rs6869366位点的多态性,比较不同基因型与PCa易感性的关系?结果:以携带TT基因型的对象为参照组,携带GT基因型者患PCa的风险是携带TT基因型的1.15倍(OR=2.15,95%CI:1.02~4.53)?结论:XRCC4 rs6869366与苏皖地区汉族人群PCa的易感性有关,GT可能是PCa的易感基因型?     

BIRC5基因rs9904341多态性与乳腺癌易感性的关联研究

目的 探索BIRC5基因-31G＞C(rs9904341)位点多态性与乳腺癌易感性的关联.方法 采用病例对照研究设计,纳入新发女性乳腺癌患者709例和749例健康对照,提取研究对象外周血细胞基因组DNA,通过聚合酶链反应-连接酶反应(PCR-LDR)对rs9904341位点进行基因分型,多因素Logistic回归分析-31G＞C(rs9904341)位点多态性与乳腺癌易感性的关联.结果 病例组中GG、GC、CC基因型分布分别为191(26.9％)、354(49.9％)、164(23.1％);对照组中GG、GC、CC基因型分布分别为184(24.6％)、382(51.0％)、183(24.4％).基因型频率分布差异无统计学意义(P =0.566).基于共显性、显性、隐性、等位基因模型,rs9904341位点与乳腺癌易感性均无显著性关联(P＞0.05).在＞50岁年龄组和已绝经女性人群,显性模型中显性基因者(GC+CC)相比于GG基因型者患乳腺癌的风险显著降低,效应值分别为:校正OR =0.61,95％ CI=0.38 ～0.96,P=0.031以及校正OR=0.63,95％ CI=0.42 ～0.95,P=0.029.结论 BIRC5基因-31G＞ C(rs9904341)位点多态性与乳腺癌易感性无显著关联,在＞50岁年龄组和已绝经女性人群中,C等位基因携带者(CG+CC)较GG基因型者患乳腺癌易感性显著降低.     

DNA损伤修复基因RAD51基因单核苷酸多态性与食管鳞状细胞癌的相关性研究

目的：探讨DNA损伤修复基因RAD51基因多态性与食管鳞状细胞癌(以下简称鳞癌)遗传易感性、临床病理特征的关系,及其在食管癌预后中的临床价值。方法：采用病例对照研究设计,选择98例食管鳞癌患者为观察组和80例正常人为对照组。选取RAD51135 G/C基因多态性为研究位点,以聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法进行多态性检测,应用Logistic回归计算比值比(odds ratio,OR)及95%CI,比较不同基因型与食管鳞癌发病风险的关系、与食管鳞癌临床病理学特征的相关性、在食管鳞癌预后中的临床价值。结果：携带RAD51135 G/C多态患者中,基因型CC、GC 与野生基因型GG 相比,患食管鳞癌的危险度OR 和95%CI 分别是1.86(0.54～6.46)和0.93(0.50～1.72)。RAD51135基因纯合及杂合型基因型与淋巴结转移状态、远处转移及复发相关。结论：RAD51135基因单核苷酸多态与当地居民食管鳞癌遗传易感性无关;与食管鳞癌患者的淋巴结及远处转移可能相关;与食管鳞癌患者预后可能相关,对食管癌患者的预后可能有一定的临床价值。     

miRNA-146a基因多态性与肝癌易感性的meta分析

目的:通过meta分析评价miRNA-146a rs2910164位点基因多态性与肝癌易感性之间的相关性。方法:系统地检索PubMed、Embase、Web of Science、中国知网以及中国生物医学文献数据库 2017年1月30日之前发表的相关文章,用总的比值比（odd ratios, OR）及相应的95%可信区间（credibility intervals, CI）来评价miRNA-146a基因多态性与肝癌易感性之间的相关性。结果:共纳入了18项病例对照研究,包括5 657例肝癌病例与6 680例健康对照。经过统计分析未发现miRNA-146a rs2910164位点的基因多态性与肝癌易感性之间存在相关性（C vs. G：OR=0.96,95%CI=0.88~1.06;GC vs. GG：OR=0.98,95%CI=0.88~1.09; CC vs. GG：OR=0.90,95%CI=0.74~1.09;GC/CC vs. GG：OR=0.95,95%CI=0.82~1.10;CC vs. GC/GG：OR=0.95,95%CI= 0.84~1.07）。结论:目前没有足够证据能够证明miRNA-146a基因多态性与肝癌易感性之间存在相关性。未来有必要在大规模和设计完善的研究中加以验证。     

IL-13基因多态性与喉癌遗传易感性的关联研究

目的:探讨白细胞介素-13(interleukin-13,IL-13)基因单核苷酸多态性(single-nucleotide polymorphism,SNP)与喉癌遗传易感性的关系?方法:通过病例-对照研究设计,以111例经病理确诊的喉癌患者和340例健康对照者为研究对象,选取IL-13基因3’-UTR的SNP位点rs1295685,采用TaqMan探针方法进行多态性检测,应用Logistic回归计算OR值及其95%CI,比较不同基因型与喉癌发病风险的关联?结果:病例组与对照组中rs1295685(IL-13C870T)位点基因型分布存在统计学差异,在调整年龄?吸烟?饮酒及肿瘤家族史因素后发现,与CC基因型相比,携带TT/CT基因型者喉癌发病风险显著增高(调整OR值为2.00,95%CI为1.23~3.27,P值为0.005)?与CC基因型相比,携带TT/CT基因型在年龄≤62岁?吸烟?饮酒?无肿瘤家族史各亚组中表现出更高的喉癌患病风险(OR = 2.72,95%CI:1.40~5.28; OR = 2.07,95%CI:1.19~3.58;OR = 1.96,95%CI:1.03~3.73;OR = 2.01,95%CI:1.18~3.41)?吸烟?饮酒均与TT/CT基因型存在协同作用(OR = 6.48,95%CI:2.77~15.14和OR = 7.35,95%CI:3.15~17.12)?而基因型分布在肿瘤分期?分级中未见显著差异?结论:IL-13基因rs1295685位点的单核苷酸多态性与喉癌遗传易感性有关联?     

福建省汉族女性乳腺癌患者MMP9基因的多态性研究

目的探讨福建地区汉族女性基质金属蛋白酶9基因(MMP9)的单体型标签单核苷酸多态性位点(htSNP)与乳腺癌遗传易感性的关系。方法采取以自然人群为基础的病例对照研究设计,选取福建地区经组织学确诊的汉族女性乳腺癌患者251例和年龄频数匹配的女性健康对照者255例。采用基质辅助激光解吸电离飞行时间质谱或聚合酶链反应-限制性内切酶片段长度多态性方法对MMP9的5个htSNP(rs17576、rs2250889、rs3787268、rs17577和rs3918254)进行基因分型。非条件Logistic回归模型被用以估计各SNP基因型与乳腺癌发病风险、临床病理特点的关系,单体型分析则采用R软件的Haplo.Stats程序包进行。结果 MMP9基因rs17577的A等位基因型携带者增加了乳腺癌的发病风险(OR=1.581,95%CI 1.082～2.310),GA+AA基因型的携带者发生乳腺癌的风险是GG基因型携带者的1.6倍(OR=1.668,95%CI 1.098～2.533);其余4个位点的基因型与等位基因型频率分布在乳腺癌组和正常对照组之间无显著性差异(P>0.05)。含有rs17577危险等位基因型A的单体型GCGCA携带者发生乳腺癌的风险是单体型GCACG携带者的1.5倍(OR=1.543,95%CI1.018～2.337)。而且rs3918254位点CT+TT基因型携带者发生高级别乳腺癌的风险是CC基因型患者的2.6倍(OR=2.632,95%CI 1.331～5.204)。结论 MMP9基因rs17577多态性位点与乳腺癌的遗传易感性显著相关;而rs3918254的CT+TT基因型有可能成为乳腺癌不良预后的分子指标。     

微小RNA前体区域基因多态与儿童特异性皮炎易感性的关联研究

目的探讨微小RNA（miRNA）前体区域基因单核苷酸多态性（SNP）与儿童特异性皮炎（AD）易感性的关系。方法采用病例-对照研究,选取AD患儿400例,年龄频率匹配的健康对照儿童400例;使用标准化的调查表获得研究对象的基本资料;采用ABI7900HT的Taqman基因分型技术检测hsa-mir-149 rs2292832、hsamir-146a rs2910164、has-mir-499 rs374644和hsa-mir-196a2 rs11614913基因多态性。结果 hsa-mir-146a基因多态性位点rs2910164与AD发病风险有关联,与CC、GG＋CG相比,纯合型CC可显著增加儿童AD的发病风险（OR=1.46,95%CI：1.18-1.81,P〈0.005;OR=1.49,95%CI：1.21-1.85,P〈0.001）;分层分析显示,CC基因型增加AD发病风险性在男性（OR=1.60,95%CI：1.24-2.02,P〈0.001）、有家庭环境香烟暴露史（OR=2.00,95%CI：1.75-2.34,P〈0.001）和无过敏性疾病家族史（OR=1.45,95%CI：1.11-1.85,P=0.011）的儿童中更加显著。未发现多态性位点hsa-mir-196a2 rs11614913、hsa-mir-149 rs2292832和has-mir-499 rs374644与儿童AD易感性有关。结论 hsa-mir-146a rs2910164 CC基因型可能增加儿童AD的发病风险。     

PD-L1基因多态性与肝癌易感性以及预后之间的关系

目的 研究PD-L1基因多态性与肝癌易感性以及患者预后之间的关系.方法 收集我院123例原发性肝癌患者和141例健康体检者的外周血淋巴细胞,应用直接测序法和PCR-SSCP检测PD-L1基因rs4143185,rs2890658和rs17718883三个位点的单核苷酸多态性.结果 rs2890658位点的AC基因型及rs17718883的CG基因型可以显著降低肝癌的发病风险(OR=0.43,P=0.035;OR=0.01,P＜0.001);而rs4143185的GG基因型可能增加肝癌的发病风险(OR=2.80,P=0.057).rs2890658位点AC+ CC和AA的中位生存时间分别为20个月和17个月(P =0.042);rs4143185位点的GC+ GG和CC中位生存时间分别为21个月和15个月,差异有统计学意义(P ＜0.001);COX回归分析显示rs4143185位点的突变基因型都可以获得好的预后,差异有统计学意义(HR＜1;且P＜0.05).结论 PD-L1基因rs2890658和rs17718883两个位点的SNP与肝癌的易感性有关,而rs2890658和rs4143185位点的SNP可能与肝癌的预后有关.     

miR-499、miR-196a2、miR-149单核苷酸多态性与系统性红斑狼疮的关联性

目的探讨系统性红斑狼疮(systemic lupus erythematosus,SLE)患者与miR-499、miR-196a2及miR-149单核苷酸多态性(single nucleotide polymorphism,SNP)的关联性。方法选取111例SLE患者(SLE组)与120例健康者(对照组)为研究对象,收集临床资料并抽取2mL外周静脉血,提取基因组DNA。利用PCR-RFLP技术对研究对象miR-499rs22928323、miR-196a2rs11614913、miR-149rs3746444的单核苷酸多态性进行检测,分析SLE与SNP的关联性。结果 miR-196a2rs11614913表现为TT、TC、CC 3种基因型,与miR-196a2基因型TT+TC相比,基因型为CC的患者发病风险增加,OR=1.28,95%CI为1.03~1.84,P=0.017;miR-149rs22928323表现为TT、TC、CC 3种基因型,与miR-149基因型TT+TC相比,基因型为CC的患者发病风险不增加,OR=0.61,95%CI为0.38~1.38,P=0.283;miR-499rs3746444表现为AA、AG、GG 3种基因型,与miR-449基因型AA+AG相比,基因型为GG的患者发病风险不增加,OR=0.78,95%CI为0.58~1.11,P=0.188。结论miR-196a2内的SNP rs11614913与中国华东地区人群SLE的遗传易感性有关;miR-499、miR-149内的SNPs rs3746444、rs22928323与中国华东地区人群SLE的遗传易感性无关。     

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.