BQ123对左向右分流肺动脉高压大鼠肺组织Ⅰ、型胶原合成的影响

目的：研究内皮素-1(ET-1)受体拮抗剂BQ123对左向右分流肺动脉高压大鼠肺组织Ⅰ、Ⅲ型胶原合成的影响，并探讨左向右分流肺动脉高压的发生机理。方法：选择Wistar大鼠34只，随机分为实验Ⅰ组(n=15)．实验Ⅱ组(n=9)，对照组(n=10)。实验组大鼠采用套管连接法建立颈部左向右分流肺动脉高压模型，实验Ⅱ组大鼠术后4周开始给予BQ123，每次50μg／kg，每周3次，连用12周，术后16周测取大鼠肺动脉收缩压。放射免疫法测定大鼠肺组织ET-1含量变化。RT-PCR检测BQ123对大鼠肺组织Ⅰ、Ⅲ型前胶原mRNA表达的影响。免疫组化法检测BQ123对大鼠肺组织Ⅰ、Ⅲ型胶原表达及相对含量的影响。结果：左向右分流大鼠肺动脉收缩压及肺组织ET-1含量升高，肺组织Ⅰ、Ⅲ型前胶原mRNA的表达增强，胶原蛋白相对含量增加；应用BQ123后大鼠肺动脉压力及肺组织ET-1含量降低，Ⅰ、Ⅲ型前胶原mR-NA的表达及胶原相对含量降低。结论：BQ123可降低肺组织ET-1含量，抑制胶原合成，ET-1和胶原合成增加均参与了肺动脉高压的形成过程。     

肺动脉管壁Ⅰ、Ⅲ型胶原变化在慢性低氧肺动脉高压形成中的作用

目的：探讨肺动脉管壁Ⅰ、Ⅲ型胶原以及Ⅰ、Ⅲ型前胶原mRNA变化在慢性低氧肺动脉高压中的作用。方法：将二级SD大鼠分为对照组（A）和低O2组（B），低O2时间为4w。采用透射电镜，免疫组化，原位杂交，图像分析等方法研究慢性低氧对大鼠肺动脉平均压（mPAP)，右心室经（RV＋LV＋S），管壁厚度占血管外径的百分比（MT％），管壁面积占管总面积的百分比（MA％），肺细小动脉超微结构，肺动脉管壁Ⅰ、Ⅲ型胶原以及Ⅰ、Ⅲ型前胶原mRNA的影响。结果：（1）B组mPAP,RV/LV＋S显高于A组（P＜0．01）。（2）光镜下B组MT％，MA％显高于A组（P＜0．01）；电镜显示B组肺动脉中膜平滑肌细胞增生，胶原纤维较A组明显为多。（3）免疫组化显示B组肺细小动脉（直径约100－200μm)I型胶原含量（平均吸光度值LD）较A组明显为高（P＜0．01），Ⅲ型胶原LD各组间差异无显性（P＞0．05）。（4）原位杂交显示B组肺细小动脉（直径约100－200μm)Ⅰ型前胶原mRNA平均吸光度值较A组明显为高（P＜0．01），Ⅲ型前胶原mRNA平均吸光度值各组是差异无显性（P＞0．05）。（5）肺细小动脉I型及胶原，I型前胶原mRNA与mPAP,MT%均呈正相关。结论：慢性低氧引起肺动脉管壁I型胶原，I型前胶原mRNA表达增多是导致肺血管重构以致形成同压的重要原因之。     

缺氧性肺动脉高压大鼠泡内肺动脉与右心室胶原表达及黄芪的干 …

目的 观察缺氧性肺动脉高压大鼠胞内肺动脉与右心室胶原表达及黄芪的干预作用,初步探讨其作用机制。方法 将雄性Ｗｉｓｔａｒ大鼠随机分为３组：（１）缺氧组：在常压缺氧舱内缺氧,每日１２小时,连续３周;（２）黄芪组：缺氧条件同缺氧组;自缺氧第一天起给大鼠每天腹腔注０．２ｍｌ黄芪注射液;（３）正常组对照组：室内空气正常饲养,用心导管和Ｆｉｃｋ’ｓ法测定肺动脉压和右心排血量,苦味酸天狼猩红染色切片观察泡内肺动     

长期吸入一氧化氮对大鼠慢性缺氧性肺动脉高压的影响及毒副作用观察

目的：探讨长期吸入一氧化氮（NO）对慢性缺氧性肺动脉高压的影响及毒副反应。方法：从54只Wistar大鼠（雌雄各半）中随机取6只作为正常对照组,其余48只常压缺氧两周复制成慢性缺氧性肺动脉高压模型后分为：缺氧组：每日继续缺氧6小时,吸入NO组：继续缺氧同时每日吸入40ppm(40/10^6)NO 1小时,于第8,15,22,29天分别观察肺动脉压力,右心室肥厚指标,血高铁血红蛋白含量以及肺组织病理学改变。结果：（1）缺氧组大鼠肺动脉平均压明显升高,右心室肥厚显著（P均＜0．01）,而吸入NO组肺动脉压降低,右心室肥厚减轻;（2）吸入NO不同时间组血高铁血红蛋白含量与缺氧组同时间及正常对照组比较无明显升高,且吸入NO各时段组间比较亦无明显差异（P均＞0．05）;（3）光镜下,缺氧组腺泡内肌型肺动脉增多,无肌肺动脉明显减少,与正常对照组及吸入NO组比较,有显著差异（P＜0．01）,吸入NO组明显改善三型血管比例失调,阻抑慢性缺氧所造成的腺泡内肺动脉肌化和肌型小动脉中膜增厚,未见明显肺泡水肿,渗出,细胞浸润等NO损伤性改变。结论：长期吸入40ppmNO可以减轻大鼠慢性缺氧性肺动脉高压,右心室肥厚以及肺小血管肌化程度,且未见明显毒副作用。     

BQ123对左向右分流肺动脉高压大鼠肺组织Ⅰ、Ⅲ型胶原合成的影响

目的:研究内皮素-1(ET-1)受体拮抗剂BQ123对左向右分流肺动脉高压大鼠肺组织Ⅰ、Ⅲ型胶原合成的影响,并探讨左向右分流肺动脉高压的发生机理.方法:选择Wistar大鼠34只,随机分为实验Ⅰ组(n=15),实验Ⅱ组(n=9),对照组(n=10).实验组大鼠采用套管连接法建立颈部左向右分流肺动脉高压模型,实验Ⅱ组大鼠术后4周开始给予BQ123,每次50μg/kg,每周3次,连用12周,术后16周测取大鼠肺动脉收缩压.放射免疫法测定大鼠肺组织ET-1含量变化.RT-PCR检测BQ123对大鼠肺组织Ⅰ、Ⅲ型前胶原mRNA表达的影响.免疫组化法检测BQ123对大鼠肺组织Ⅰ、Ⅲ型胶原表达及相对含量的影响.结果:左向右分流大鼠肺动脉收缩压及肺组织ET-1含量升高,肺组织Ⅰ、Ⅲ型前胶原mRNA的表达增强,胶原蛋白相对含量增加;应用BQ123后大鼠肺动脉压力及肺组织ET-1含量降低,Ⅰ、Ⅲ型前胶原mR-NA的表达及胶原相对含量降低.结论:BQ123可降低肺组织ET-1含量,抑制胶原合成,ET-1和胶原合成增加均参与了肺动脉高压的形成过程.     

纤溶异常在慢性阻塞性肺病早期缺氧大鼠肺纤维化中的作用

目的探讨慢性阻塞性肺病（COPD）早期缺氧时纤溶异常与肺纤维化的关系。方法将70只雄性SD大鼠随机分为无缺氧对照组（10只）、COPD缺氧1个月组（一月组,20只）、COPD缺氧2个月组（二月组,20只）及COPD缺氧3个月组（三月组,20只）。模型建立成功后各组大鼠行肺功能测定,处死后肺组织作病理切片,并以HE染色及免疫组化法检测肺组织I、Ⅲ型胶原的表达情况;采用ELISA法测定大鼠肺泡灌洗液（BALF）及血浆中抗凝血酶Ⅲ（AT-Ⅲ）和纤溶酶原激活物抑制剂（PAI-1）的浓度。结果COPD缺氧各组大鼠均形成明显的肺泡炎和肺间质纤维化,并随着缺氧时间延长逐渐加重。与对照组比较,其它三组大鼠I型胶原的表达均明显增强（P〈005）、一月组和二月组Ⅲ型胶原的表达均明显增强（P〈0．05）、三月组Ⅲ型胶原的表达均明显降低（P〈0．05）;与一月组比较。二月组及三月组I型胶原表达均明显增强（P〈0．05）、三月组Ⅲ胶原表达明显降低（P〈0．05）;与二月组比较,三月组I型胶原的表达明显增强（P〈0．05）、Ⅲ型胶原的表达均明显降低（P〈0．05）;三月组I/Ⅲ胶原表达比值较之其它各组均明显增大（P〈0．05）。模型组大鼠BALF及血浆中AT－Ⅲ浓度均较对照组明显降低（均P〈0．05）,二月组及三月组PAI－1浓度均较对照组明显升高（均P〈0.05）;二月组及三月组BALF中PAI－1浓度均较一月组明显升高（均P〈0．05）;三月组BALF中PAI－1浓度较二月组亦明显升高（P〈0.05）。结论COPD早期缺氧所致纤溶异常在肺纤维化的发病过程中起着一定的作用;缺氧时间越长,AT－Ⅲ产生越少,PAI－1合成增多,进而引起肺泡内纤维蛋白形成的增加和清除障碍,这种失衡促进了肺间质纤维化的发生。     

缺氧对大鼠心肌胶原网架改建的作用

目的 观察缺氧大鼠右心室心肌胶原网架改建的特点，并探讨血浆Ⅲ型前的胶原（ＰＣⅢ）含量的变化是否能反映心肌胶原含量和浓度的变化。方法 ４０只Ｗｉｓｔａｒ大鼠分为两组：①常氧对照组；②慢性缺氧组：缺氧大鼠暴露于模拟５０００ｍ高原３０ｄ和６０ｄ，８ｈ／ｄ。测定其ＰａＯ２；左、右心室收缩压，观察心肌胶原含量及形态学变化。结果：慢性缺氧可以引起ＰａＯ２下降、右心室收缩压及右心室重量指数增加。缺氧大鼠右心室心     

慢性缺氧大鼠肺组织钙调素活性研究

为探讨钙调素（ＣａＭ）在慢性缺氧性肺动脉高压发病中的作用，将４０只Ｗｉｓｔａｒ大鼠随机分为四组，Ⅰ组为正常对照组，不接受任何处理。Ⅱ、Ⅲ、Ⅳ组为实验组，分别间断缺氧１、２、３周，而后采用火焰原子吸收分光光度法及磷酸二酯酶法测定四组大鼠肺组织Ｃａ２＋含量及ＣａＭ活性。结果显示：缺氧１、２、３周均能引起大鼠平均肺动脉压（ｍＰＡＰ）及肺血管阻力（ＰＶＲ）增高，心输出量（ＣＯ）降低；缺氧大鼠肺组织Ｃａ２＋含量及ＣａＭ活性较正常对照组增高，其中缺氧２周及３周组大鼠肺组织ＣａＭ活性与正常对照组比较有显著性差异（Ｐ＜０．０５），但缺氧１周组大鼠ＣａＭ活性与正常对照组比较差异无统计学意义；肺组织Ｃａ２＋含量与ＣａＭ活性呈明显正相关（Ｐ＜０．０５），提示Ｃａ２＋－ＣａＭ系统在大鼠缺氧性肺动脉高压的发生中起一定作用。细胞内Ｃａ２＋浓度增高，可促使ＣａＭ由细胞骨架移行到细胞浆内，可能是慢性缺氧大鼠肺组织ＣａＭ活性增高的原因之一。     

慢性缺氧对肺外动脉胶原堆积及胶原基因表达的影响

慢性缺氧对肺外动脉胶原堆积及胶原基因表达的影响［吴康健，严仪昭，李红兵，等．中华结核和呼吸杂志１９９４，１７（３）１５２］模拟５０００ｍ连续低压缺氧７天复制大鼠肺动脉高压模型，观察结构重建的肺外动脉胶原含量及其基因表达的变化。结果表明，缺氧７天大鼠肺...     

缺氧性肺动脉高压大鼠肺动脉一氧化氮合酶的实验研究

目的：研究大鼠肺动脉中一氧化氮合酶（ｎｉｔｒｉｃ ｏｘｉｄｅｓｙｎｔｈａｓｅ,ＮＯＳ）的含量及分布变化与慢性缺氧性肺动脉高压（ｈｙｐｏｘｉｃｐｕｌｍｏｎａｒｙ ｈｙｐｅｒｔｅｎｓｉｏｎ, ＨＰＨ）发生的关系。方法：采用ｅＮＯＳ多克隆抗体,对慢性ＨＰＨ 大鼠的肺组织进行免疫组织化学分析,观察缺氧组及对照组大鼠各级肺动脉中ｅＮＯＳ含量及定位;同时应用分光光度计测定缺氧组及对照组大鼠血浆中ＮＯ的间接浓度。结果：正常大鼠肺动脉内皮细胞及平滑肌细胞均含有较高的ｅＮＯＳ表达,且各级肺动脉中ｅＮＯＳ含量差异无显著性;缺氧组大鼠各级肺动脉内皮细胞及平滑肌细胞ｅＮＯＳ含量均较对照组显著减少;缺氧组大鼠血浆ＮＯ间接浓度较对照组明显降低。结论：大鼠肺动脉内皮细胞和平滑肌细胞ｅＮＯＳ含量下降及血浆ＮＯ浓度下降参与慢性ＨＰＨ 的形成。     

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.