人工下颌骨在不同应变率下的压缩强度

研究下颌骨在不同应变率下的生物力学性质，分析应变率和骨密度对压缩强度、弹性模量和破坏应变的影响。方法以５具新鲜男性青年尸体的下颌骨为材料，对每具标本进行骨密度测定，然后制成标准试件在ＩＮＳＴＯＲＮ材料试验机上进行电子压缩，应变率分别为０．０００５，０．００５，０．０５，０．５ｓ＾－１获得不同应变率下的应力－应变曲线，下颌骨的极限强度，弹性模量以及破坏应变。应用Ｏｒｉｇｉｎ５．０软件在ＰＣ机上进行数     

犬脱钙骨基质颗粒骨水泥复合材料的生物力学性能

目的　研究不同质量比的犬脱钙骨基质颗粒骨水泥复合材料的生物力学性能 ,为临床应用该复合材料修复骨缺损提供理论依据 .方法　按 U rist等方法制备犬脱钙骨基质颗粒后 ,再与骨水泥混合制成含骨粒质量比为 0 ,40 0 ,5 0 0和6 0 0 m g·g- 1 的脱钙骨基质颗粒骨水泥复合材料 ,对其抗压极限强度、抗弯极限强度、抗扭转极限强度进行测定 .结果　含脱钙骨基质颗粒质量比为 0 ,40 0 ,5 0 0和 6 0 0 mg· g- 1的复合材料的抗压极限强度分别为 (81.0± 3.0 ) ,(5 0 .4± 5 .9) ,(4 8.8± 2 .0 )和 (33.8± 3.6 ) MPa;抗弯极限强度分别为 (6 5 .3± 6 .7) ,(4 2 .9± 8.1) ,(37.2± 2 .9)和 (2 5 .0± 2 .4) MPa;抗扭转极限强度分别为 (35 .5± 0 .8) ,(16 .3± 2 .2 ) ,(13.1± 2 .0 )和 (8.0± 1.4) MPa.结论　犬脱钙骨基质颗粒骨水泥复合材料具有良好的生物力学性能 ,易于塑形 ,能根据需要适应不同部位骨缺损的要求 ,其中含骨粒质量比为 5 0 0 mg· g- 1的复合材料生物力学性能及骨诱导活性最为适宜 ,能作为支架材料有效地修复大块骨缺损 .     

椎体骨密度与椎体生物力学的关系

目的探讨椎体骨密度(BMD)与其生物力学的关系。方法取5具女性和3具男性福尔马林浸泡的胸腰段脊柱标本(T8~L5),X线摄片无明显病理异常,双能X线吸收骨密度仪(DEXA)测定椎体骨密度(BMD)。将标本游离成单个椎体,去除椎间盘及附件等。共选择60个椎体,按骨密度分对照组(正常)、轻中度和重度骨质疏松组,即A组、B组和C组。用材料试验机轴向加载,压缩椎体高度25%,制造椎体压缩骨折,确定椎体的初始压缩强度和刚度。结果对照组、轻中度和重度骨质疏松组平均骨密度分别为(1.098±0.147)、(0.650±0.137)和(0.393±0.060)g/cm2;3组间的压缩强度分别为(6.775±1.952)、(3.450±0.909)和(2.395±0.697)KN;刚度分别为(2.216±0.897)、(1.391±0.461)和(0.942±0.206)KN/mm。BMD与椎体压缩强度和刚度呈正相关;3组间的BMD、最大抗压力和刚度均存在显著性差异(P<0.01)。结论椎体BMD与椎体的生物力学性质有较明显的相关关系,对骨质疏松的早期诊断和预测椎体压缩性骨折危险性有一定的参考意义。     

肝炎肝硬化螺旋CT门静脉造影扫描延迟时间的合理选择

目的　应用时间—密度曲线选择正常人和肝炎肝硬化患者螺旋 CT门静脉造影的合理扫描延迟时间 .方法　 2 0例正常人和 1 8例肝炎后肝硬化患者于第一肝门水平门静脉主干分叉以下 1 0 mm处行同层动态增强扫描 .造影剂量 1 .5m L· kg-1 ,注射速率 3 m L· s-1 ,经外周静脉注射造影剂后1 5 s开始扫描 ,以后每隔 5 s扫描 1次 ,持续至 1 2 0 s.分别测量同一层面门静脉、肝脏的 CT值 ,并计算各点门静脉与肝脏的密度差 (P- L) ,描绘时间 -密度曲线 .结果　正常组与肝硬化组门静脉平均强化峰值分别为 (1 81± 34) Hu,(1 59± 2 9)Hu(P<0 .0 5) ,峰值到达时间分别为 (54± 7) s,(65± 9) s(P<0 .0 5) .肝脏平均强化峰值分别为 (1 1 8± 1 9) Hu,(96±1 3) Hu(P<0 .0 5) ,峰值到达时间分别为 (64± 9) s,(75±1 0 ) s(P<0 .0 5) .门静脉和肝脏密度差最大值两组分别为(9 0± 2 8) Hu,(73± 1 6) Hu(P<0 .0 5) ,其达到最大密度差时间分别为 (50± 7) s,(65± 3) s(P<0 .0 1 ) .结论　行肝脏螺旋 CT门静脉造影成像显示肝内门静脉分支 ,造影剂量为 1 .5m L· kg-1 ,注射速率为 3m L· s-1 ,正常人最佳扫描延迟时间为 40 s,肝炎后肝硬化患者最佳扫描延迟时间为 50 s     

雌性猪尿道壁应力应变关系的测量:预测女性尿道壁排尿期力学变化

目的研究雌性猪尿道壁的应力应变关系,仿真预测女性排尿过程中力学变化。方法将雌性猪尿道壁样品拉伸直至断裂,测量拉伸过程中拉力和变形,计算应力应变关系、极限应变和极限应力,并统计分析。结果对应力-应变曲线使用二次多项式进行拟合,得到表达式σ=aε2+bε(σ为应力,ε为应变,a=0.3727±0.1471,b=-0.0735±0.0767),决定系数R2=0.9935±0.0034,极限应变为1.096±0.3099,极限应力为(0.3469±0.1974)MPa。结论尿道组织的弹性模量随变形增加而增加。对女性正常排尿生理过程进行仿真计算,尿道的壁应力为2.226×10-3MPa,应变为0.4507,弹性模量为0.5536MPa。     

成人动脉导管未闭Amplatzer封堵器封堵术后左心功能的变化

目的　应用超声心动图评价 Amplatzer封堵器治疗成人动脉导管未闭 (PDA)术后左心功能的变化 .方法　 6 8例成人 PDA (男 2 6例 ,女 4 2例 ) ,年龄 18～ 6 5 (32± 2 7)岁行Am platzer封堵器根治 PDA术 .应用超声心动图测量封堵前后左室舒张末期内径 (L VEDD)和收缩末期内径 (L VESD) .应用椭圆体体积法计算出左室舒张末期容积 (L VEDV)、收缩末期容积 (L VESV)、每搏搏出量 (L VSV)、射血分数 (L VEF)和短轴缩短率 (L VFS) ,将封堵前后测量数据分别用统计学配对 t检验 .结果　 L VEDD,L VEDV,L VESV,L VSV封堵前分别 (6 0± 9) mm,(2 2 8± 90 ) m L,(5 4± 2 7) m L,(172± 74 )m L;封堵后 5 d分别降为 (5 0± 7) mm,(130± 6 0 ) m L,(41±2 1) m L ,(96± 4 5 ) m L (P<0 .0 5 ) ;封堵后 3mo分别为 (48±7) m m,(112± 5 0 ) m L ,(38± 17) m L ,(91± 4 0 ) m L (P<0 .0 5 ) ;L VEF,L VFS封堵前分别为 (5 6± 18) % ,(38± 5 ) % ;封堵后 5 d分别为 (5 1± 2 0 ) % ,(36± 6 ) % (P>0 .0 5 ) ,封堵后3mo分别为 (5 7± 8) % ,(38± 8) % .结论　 Amplatzer封堵器治疗成人 PDA能缩短 L VEDD和改善左心功能 .     

牛血红蛋白延长兔离体心脏的保存时间

目的　提高心肌保护效果 ,延长供心的保存时限 .方法　将 2 4只大白兔分为两组 ,每组 12只 ,在 St Thomas 液中加入无机质游离牛血红蛋白 ( SFBHB)作为载氧体 ,常温灌注离体兔心 6 h作为实验组 ,用单纯 St Thomas 液低温保存离体兔心作为对照组 .结果　左室发展压 [L VDP,( 13.77±1.36 ) k Pa vs( 7.2 2± 1.13) k Pa,P<0 .0 1],冠状动脉流量恢复率 [CFR,( 92 .8± 5 .16 ) % vs( 5 9.0 7± 9.5 9) % ,P<0 .0 1]均显著高于对照组 ;心肌组织 ATP含量在保存 4h后两组即有明显差异 [( 30 .1± 2 .6 ) μmol.g- 1 vs( 2 7.2± 3.7) μmol.g- 1 ,P<0 .0 5 ],复跳 30 min后 ,实验组较对照组心肌组织的ATP含量明显升高 [( 2 9.9± 3.6 ) μmol.g- 1 vs( 10 .9± 4.4)μmol.g- 1 ,P<0 .0 1];同时 ,试验组心肌氧摄取量明显高于对照组 [( 5 37.3± 12 4.0 ) nmol.s- 1 .g- 1 vs( 90 .5± 39.5 ) nmol.s- 1 .g- 1 ,P<0 .0 1],心肌组织内的丙二醛 [MDA,( 6 .2 4± 2 .10 ) μmol.g- 1 vs( 18.6 0± 5 .6 3) μm ol.g- 1 ,P<0 .0 1]含量及冠状静脉引流液中肌酸磷酸激酶 [CPK,( 1.1± 0 .1) nkat.s- 1.g- 1 vs( 3.6± 0 .5 ) nkat.s- 1 .g- 1 ,P<0 .0 1],乳酸脱氢酶[L DH,( 2 30 .4± 6 0 .9) nkat.15 min- 1 .g- 1 v     

先天性心脏病肺动脉高压心内直视手术患者吸入NO对再灌注肺功能的影响

目的　评价先天性心脏病合并肺动脉高压患者吸入一氧化氮 (NO)对再灌注肺功能的影响 .方法　先天性心脏病合并中重度肺动脉患者 4 4例 ,分为对照组 (2 2例 )和吸入NO组 (2 2例 ) .吸入 NO组在升主动脉开放即刻连续吸入NO2 0 m L· L- 1 2 4 h,监测和计算平均动脉压 (m Bp)、平均肺动脉压 (m PA)、肺血管阻力 (PVR)、心排出量 (CO) ;氧分压(Po2 )、二氧化碳分压 (Pco2 )、肺泡动脉氧分压差 (A- a Do2 )、肺内动静脉分流 (Qs/ Qt) .结果　吸入 NO组 m PA肺再灌注后3,6 ,12 ,2 4 h分别为 (5 .8± 1.9) ,(5 .6± 1.6 ) ,(5 .1± 1.3)和 (4.4± 1.1) k Pa,对照组为 (7.8± 1.6 ) ,(7.3± 1.7) ,(6 .8± 1.5 )和 (6 .9± 1.5 ) k Pa,吸入 NO组下降显著 (P<0 .0 5 ) ;吸入 NO组 m PVR肺再灌注后 3,6 ,12 ,2 4 h分别为(87± 17) ,(79± 12 ) ,(6 7± 9)和 (6 0± 9) k Pa· s· L- 1 ,对照组为 (14 5± 2 2 ) ,(135± 16 ) ,(130± 14 )和 (114± 11) k Pa· s- 1·L- 1 ,吸入 NO组下降明显 (P<0 .0 5 ) ;吸入 NO组肺再灌注后 6 ,12 ,2 4 h分别为 (4.2± 1.2 ) ,(4.5± 0 .9)和 (4.4± 1.2 )L· min- 1 ,对照组为 (3.3± 0 .8) ,(3.4± 0 .8)和 (3.5± 0 .9)L· min- 1 ,吸入 NO组明显升高 (P<0 .0 5 ) .与对照     

加减麦门冬汤对大鼠胃排空的影响

目的　观察加减麦门冬汤对大鼠胃排空的影响。方法　 9周龄的SD大鼠随机分为 :A组 (空白对照组 )、B组 (吗丁啉组 )、C组 (中药小剂量组 )、D组 (中药大剂量组 )。用药 4周后 ,用放射性核素法检测其胃的排空率。结果　B、C、D组的 30分钟 ,6 0分钟胃排空率分别为 (5 5 .13±6 .81) % ,(73.2 4± 17.5 2 ) % ,(5 8.6 5± 15 .13) % ,(6 0 .77± 19.37) % ,(5 8.15± 9.42 ) % ,(6 7.82±6 .76 ) % ,均明显高于A组 :(33.16± 15 .6 4) % ,(48.47± 12 .35 ) % ,(P <0 .0 1)。结论　加减麦门冬汤对大鼠胃排空有促进作用。     

2型糖尿病模型GK大鼠骨形态学和生物力学特点观察

目的 观察2型糖尿病模型GK大鼠的骨代谢特点以及骨密度和骨生物力学特性的变化.方法 采用雄性6月龄GK大鼠10只,以月龄、性别匹配的健康Wistar大鼠作为正常对照.颈静脉取血检测与骨代谢有关的生化指标.DXA法测定股骨和腰椎骨密度,并行股骨三点弯曲实验和腰椎压缩实验.甲基丙烯酸甲酯包埋胫骨干骺端以制备不脱钙骨切片.应用多媒体病理图像分析软件进行骨组织形态计量学分析.结果 GK大鼠体重明显低于健康对照Wistar大鼠(P<0.01).与对照组相比,GK大鼠血清骨钙素水平明显降低[(4.97±0.49,6.75±0.71)μg/mL,P<0.01],而抗酒石酸酸性磷酸酶活性明显升高[(17.92±5.23,8.31±2.69)U/L,P<0.01],但血钙和血磷无明显变化(P>0.05);股骨和腰椎骨密度显著降低[(0.16±0.01,0.22±0.02;0.12±0.01,0.16±0.02)g/cm2,P<0.01];骨强度和腰椎的弹性模量明显降低(P<0.01).骨形态学分析显示GK大鼠股骨长度和第五腰椎高度分别降低10.3%和9.5%(P<0.01),股骨和腰椎横截面积无明显变化(P>0.05).骨组织形态计量学分析显示,GK大鼠骨小梁体积、骨小梁厚度、类骨质表面和厚度明显降低[(15.72±1.18,19.13±1.13)%,(61.91±4.54,74.43±3.63)μm,(18.18±1.25,19.63±1.07)%,(3.68±0.48,4.34±0.35)μm,P<0.01或0.05],动态参数如矿化表面、矿化沉积率和骨形成率也明显降低[(17.77±1.54,19.56±2.07)%,(1.07±0.22,1.35±0.16;0.20±0.03,0.26±0.04)μm/day,P<0.05或0.01],而矿化延迟时间显著延长(2.66±0.56,2.12±0.35,P<0.05).结论 非肥胖的GK大鼠表现有骨量减少和骨折危险性增加;2型糖尿病本身可干扰成骨细胞功能和活性而导致骨重建失衡.     

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.