体外循环术中肺动脉灌注低温保护液对肺的保护作用研究

目的:探讨体外循环术中肺动脉灌注低温保护液对肺保护的作用。方法:将72例体外循环术患者随机分为观察组与对照组,每组36例,观察组术中给予肺动脉灌注低温保护液,对照组则不灌注,观察两组患者的氧指数及气道阻力情况。结果:观察组患者术后的氧指数及气道阻力均优于对照组患者,组间差异有统计学意义(P<0.05)。结论:体外循环术中肺动脉灌注低温保护液对肺有较好的保护作用,能够减少或减轻术后肺损伤,值得临床进一步推广使用。     

含银杏叶提取物的肺保护液对心内直视术患者肺的保护作用

目的探讨体外循环（CPB）期间肺动脉灌注低温含银杏叶提取物的肺保护液对MDA、IL-6和TNF-α的影响，观察其对肺脏的保护作用。方法30例二尖辩置换术患者随机等分为保护组和对照组，均在CPB下行心内直视术，保护组CPB期间经肺动脉灌注低温含银杏叶提取物的保护液，对照组灌注等量生理盐水，其他处理与保护组相同。监测CPB前和CPB后0．6、12和24h患者的血氧指数、血浆丙二醛（MDA）、肿瘤坏死因子仪（TNF-α）及白细胞介素6（IL-6）的变化，并观察肺组织形态学改变。结果保护组各时点血氧指数均高于对照组（P〈O．05），CPB后血浆MDA、IL-6和TNF-α水平较术前升高（P〈O．05）；在CPB后各时间点，肺保护组患者血浆IL-6、TNF-α和MDA均低于对照组（P〈O．05）；对照组肺组织可见中性粒细胞浸润、肺间质水肿、肺泡壁小血管扩张、充血，保护组肺组织炎性反应较轻微。结论CPB可引起患者术后血浆MDA、IL-6和TNF-α水平升高；经肺动脉灌注低温含银杏叶提取物的肺保护液可抑制心内直视术后患者血浆MDA、IL-6以及TNF-α的表达，减轻肺组织的炎性损伤。     

肺动脉灌注去白细胞肺保护液对体外循环肺的保护作用

目的 探讨肺动脉灌注去白细胞肺保护液对体外循环(CPB)肺的保护作用及其机制.方法 将30例CPB下行二尖瓣置换术患者随机分为3组:去白细胞肺保护组(A组)、普通肺保护组(B组)及对照组(C组),每组10例.A组CPB期间经肺动脉灌注低温去白细胞肺保护液;B组CPB期间经肺动脉灌注低温肺保护液,C组患者常规行瓣膜置换术.监测3组患者术中主动脉阻断时间、CPB时间、术前术后平均肺动脉压力(PAPm)、气道阻力(AR)及静态肺顺应性(CLS)的变化、术后呼吸机辅助时间、ICU监护时间和住院时间以及术后并发症发生情况等;测定3组患者CPB前和CPB后0、6、12、24 h血清丙二醛(MDA)、白细胞介素-6(IL-6)及肿瘤坏死因子-α(TNF-α)的变化.结果 3组患者手术顺利,均痊愈出院,无术后并发症.3组术中主动脉阻断时间、CPB时间、术后ICU监护时间、住院时间及CPB前血清MDA、IL-6、TNF-α含量比较,差异均无统计学意义(均P＞0.05);A、B组的术后呼吸机辅助时间、CPB后0、6、12、24 h呼吸指数(RI)、氧合指数(OI)、血清MDA、IL-6、TNF-α及术前、术后PAPm、CLS、AR变化与C组比较差异均有统计学意义(均P＜0.05);临床及生化指标在A、B组比较差异均无统计学意义(均P＞0.05).结论 CPB期间肺动脉灌注去白细胞肺保护液可明显减轻CPB肺损伤,与单纯CPB期间经肺动脉灌注低温肺保护液比较,两者肺保护效果无明显差别.     

洗涤红细胞保护液肺动脉灌注对体外循环术后肺损伤的影响

目的观察心内直视手术中采用低温洗涤红细胞保护液肺动脉灌注对肺损伤的影响。方法选择风湿性二尖瓣病变伴中重度肺动脉高压(PH)的患者30例,分为肺动脉灌注组和对照组(各15例)。灌注组在升主动脉阻断后,经主肺动脉间断灌注低温洗涤红细胞保护液,测定并记录两组患者围术期的肺血管阻力(PVR)、静脉血与动脉血白细胞计数比值(V/A)、肺循环血浆丙二醛(MDA)含量及氧合指数(OI)、机械辅助通气时间。结果(1)PVR:转流结束即刻、术后12、24h灌注组(46·4kPa·s·L-1±8·1kPa·s·L-1、48·5kPa·s·L-1±7·0kPa·s·L-1、36·1kPa·s·L-1±6·3kPa·s·L-1)明显低于对照组(65·7kPa·s·L-1±5·3kPa·s·L-1、79·8kPa·s·L-1±8·7kPa·s·L-1、47·9kPa·s·L-1±7·1kPa·s·L-1,均P<0·05)。(2)MDA含量:转流结束即刻、术后12、24h灌注组(分别为14·3mmol/L±0·8mmol/L、16·1mmol/L±0·7mmol/L、13·3mmol/L±0·5mmol/L)明显低于对照组(18·9mmol/L±0·9mmol/L、21·6mmol/L±0·4mmol/L、22·5mmol/L±0·7mmol/L,均P<0·05)。(3)V/A比值:转流结束即刻、术后12h灌注组(1·16±0·05、1·20±0·05)明显低于对照组(1·53±0·07、1·68±0·25,均P<0·01)。(4)OI:转流结束即刻、术后12、24h灌注组(370±33、388±41、414±40)明显高于对照组(217±30、210±36、222±33,均P<0·05)。(5)机械辅助通气时间:灌注组(13h±4h)显著低于对照组(27h±6h,P<0·01)。结论洗涤红细胞保护液肺动脉灌注可以减轻体外循环术后肺损伤。     

自体肺体外循环对肺缺血再灌注损伤的保护作用研究

目的:探讨自体肺体外循环对肺缺血再灌注损伤的保护作用.方法:16只健康成年杂种犬随机分为实验组和对照组,每组8只.实验组为自体肺体外循环组,利用犬自体肺作为氧合器,对照组利用鼓泡式氧合器.实验组同时行左心和右心转流,对照组行常规转流.两组采用相同的心肌保护(冷晶体停跳液),两组体外循环均持续1h,于体外循环前、停机第5、30、60、90min后分别测定:右、左心房白细胞记数,并记算其比值;肺动脉压;动脉血氧分压.两组于体外循环前、体外循环结束后,分别取肺标本(3cm×3cm×2cm)行病理学检查.结果:体外循环后右、左心房白细胞比值自体肺组低于常规体外循环组;体外循环后自体肺组肺动脉压低于常规体外循环组,其中第30、60、90min时间点有显著性差异;自体肺组体外循环后动脉血氧分压高于常规体外循环组,差异有显著性.肺标本组织学检查示:体外循环后自体肺组肺标本毛细血管轻度淤血,轻度中性粒细胞及淋巴细胞聚集;无肺水肿、肺不张;肺泡腔隙基本正常,无明显肺组织损伤性改变.人工肺组体外循环后毛细血管、小静脉严重淤血,中性粒细胞显著聚集.结论:自体肺体外循环组有较好的肺保护作用,减轻了缺血再灌注对肺的炎症损伤.     

含抑肽酶的低温保护液肺动脉灌注对体外循环术后肺的保护作用

目的　研究体外循环 ( cardiopulmonary bypass,CPB)期间低温保护液肺动脉灌注对肺的保护作用。方法　 12只杂种犬随机分为对照组和实验组。主动脉阻断后 ,对照组经右肺动脉灌注 4℃乳酸林格液 ,实验组经右肺动脉灌注4℃含抑肽酶的低温保护液。开放主动脉并停 CPB后收集肺静脉血标本进行生化分析 ,测定肺功能并进行组织学检查。结果　实验组气道压在 CPB结束后显著低于对照组 ( P<0 .0 5) ;两组右肺静脉血氧分压在 CPB结束后 30 ,60 min均较左肺静脉血氧分压高 ,实验组右肺静脉血氧分压在停 CPB60 min时显著高于对照组 ( P<0 .0 5) ;实验组右房 /右肺静脉白细胞比值和脂质过氧化物 ( malondialdehyde,MDA)在开放主动脉后 5min明显低于对照组 ( P<0 .0 5) ;组织学观察提示两组左肺均有明显肺泡内出血和间质水肿 ,对照组右肺病理改变较左肺轻 ,实验组右肺组织结构基本正常。结论　 CPB期间肺动脉灌注含抑肽酶的低温保护液可以明显减轻 CPB对肺造成的损伤     

低温肺保护液肺动脉灌注对首次单纯二尖瓣置换病人的肺保护作用

目的 :研究体外循环期间低温保护液肺动脉灌注对单纯二尖瓣置换病人的肺保护作用。方法 :将 2 0例单纯二尖瓣置换病人随机分为对照组和实验组。实验组在主动脉阻断后、主动脉根部灌注心脏停搏液的同时 ,经肺动脉灌注 4℃含抑肽酶、沐舒坦的低温保护液 ,对照组则不灌注肺保护液 ,分别于术前、开放升主动脉后 2 0 min、体外循环结束时采集外周动脉血 ,进行中性粒细胞计数 ,分别于术前、体外循环结束后 0、3、6和 1 2 h检测动脉血氧分压 ( Pa O2 )、吸入氧浓度 ( Fi O2 ) ,计算氧指数 ( Pa O2 /Fi O2 )及肺泡 -动脉氧压力差 ( P〔 A-a〕O2 )。结果 :对照组在升主动脉开放 2 0 min中性粒细胞计数较术前明显降低 ,实验组的中性粒细胞计数在体外循环结束时明显高于术前 ,实验组与对照组的 Pa O2 /Fi O2 在体外循环结束后 6h达到最低点 ,实验组的氧指数在体外循环结束后 1 2 h回升接近术前正常水平 ,而对照组则未回升至术前正常水平。在体外循环结束后 0、3、6和 1 2 h,实验组的 Pa O2 /Fi O2 均明显高于对照组。再灌注 60 min后实验组 P〔 A-a〕O2 明显低于对照组。实验组气道阻力在体外循环后各时间点明显低于对照组。结论 :体外循环后存在肺损伤 ,使用含抑肽酶低温肺动脉灌注液可明显减轻首次单纯二尖瓣置换     

肺动脉灌注HTK液对肺动脉高压先心病患儿术后的肺保护作用

目的  研究体外循环期间肺动脉灌注HTK保护液对合并肺动脉高压的先心病患儿的肺保护作用。方法  将40例合并肺动脉高压的先心病患儿随机分为灌注组（体外循环+HTK液肺动脉灌注,n＝20）和对照组（体外循环, n＝20）,进行心内畸形矫治,并于麻醉前、主动脉开放时、开放后6 、12 、24h 分别抽取动脉血样,测定血清中白介素-6（IL-6）和丙二醛（MDA）的浓度,并在相应的时间点抽取动脉血样行血气分析,计算各时间点的呼吸指数（RI）及氧和指数（OI）。结果  术后两组患儿血清中IL-6和MDA的浓度较术前明显升高,但灌注组明显低于对照组（P＜0.05）。灌注组患儿术后的RI及OI明显好于对照组（P＜0.05）。结论  体外循环期间行肺动脉灌注HTK液对合并肺动脉高压的先心病患儿有一定的肺保护作用。     

体外循环中肺动脉灌注和间断肺通气的肺保护作用

目的: 探讨肺动脉灌注4℃含氧冷血和间断肺通气对体外循环(cardiopulmonary bypass,CPB)肺损伤的保护作用?方法: 将30例符合条件的心脏手术患者采用随机数字表法分为两组:肺保护组(n=15):CPB期间经肺动脉间断灌注4℃含氧冷血,并在灌注期间给予间断肺通气;对照组(n=15):常规行心脏手术?记录呼吸机支持时间;分别在CPB前和CPB结束及结束后1?6 h测算氧合指数(OI)?呼吸指数(RI)?肺气道阻力(Raw)和肺静态顺应性(Cstat)?结果: 术后肺保护组呼吸机支持时间明显短于对照组(P < 0.05),肺保护组CPB结束后1?6 h OI?Cstat均显著高于对照组(P < 0.05或P <0.01),而RI?Raw均显著低于对照组(P <0.05和P < 0.01)?结论: 肺动脉含氧冷血间断灌注及间断肺通气对CPB肺损伤有良好的保护作用?     

白细胞过滤对肺保护作用的临床研究

目的探讨心肺再灌注早期循环血白细胞过滤对体外循环(Extracorporeal c ircu lation,ECC)心瓣膜置换术患者的肺保护作用。方法52例心瓣膜置换术患者,随机分成实验组(EG)和对照组(CG)。实验组在动脉旁路上并行安装白细胞滤器(Pall LG-6),白细胞滤器开放时间在心肺再灌注前5 m in~10 m in至ECC结束;对照组仅用ECC常规动脉滤器。观察术中及术后循环血白细胞计数、再灌注肺内白细胞隔离、ECC前后肺动脉压改变、机械辅助通气和动脉血气分析。结果①在心肺再灌注前,白细胞过滤可显著降低循环血中的白细胞计数;②再灌注15 m in时白细胞过滤对肺内白细胞隔离的影响并不明显;③白细胞过滤可缓和ECC后肺动脉压力的上升;④白细胞过滤可显著降低术后呼吸指数(R I)和提高机械通气氧合指数(O I)。结论再灌注前及再灌注早期循环血白细胞过滤可明显改善心瓣膜置换术患者术后肺功能。     

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.