壳寡糖的酶法制备

通过还原端基、酶解产物聚合度、水解液调碱性后透光率的测定以及酶解产物的TLC、HPLC分析,研究了壳聚糖酶降解壳聚糖过程中壳聚糖浓度、酶用量、反应时间和pH对酶促反应速率和产物聚合度的影响。结果表明:壳聚糖酶在底物浓度0.03 g/mL、壳聚糖酶用量4~6 u/g、pH=5.8和水解200 min时,可得到以聚合度3~7为主的壳寡糖。     

非专一性酶催化壳聚糖水解反应的特性

某些非专一性酶对壳聚糖具有一定的降解作用，具有普遍的壳聚糖酶的活性。α-淀粉酶对壳聚糖的降解作用受温度、底物浓度、酶浓度、反应时间、pH等因素的影响，其最佳反应条件为壳聚糖浓度20g/L，酶浓度4g/L,pH值6.0，反应温度50℃。降解反应初期是以内切的方式进行，所得到的壳寡糖具有较低的分散度。     

壳寡糖的制备及其对黄瓜的促生长作用

研究壳聚糖在乳酸介质中的氧化降解工艺，以制备数均分子量为2000－3000的壳寡糖。通过条件实验得到最佳工艺条件为：20g壳聚糖溶于8mL乳酸中，滴加ω＝0．30的H2O25mL,于55℃下反应6h。温室试验结果证明壳寡糖对黄瓜具有良好的促生长作用。     

超细聚甲基硅氧烷微球的制备

采用水解-缩聚两步法以甲基三甲氧基硅烷（MTMS）为原料制备微米级聚甲基硅氧烷微球，粒径为1～15pm，粒径分布较窄；就反应体系pH值、油水比等条件对微球粒径大小、形态及其分布的影响进行了研究。结果表明，较优的反应条件为：在水解过程应控制pH=4．0～6．0之间，投料油水比（MTMS与水的摩尔比）应小于1／4，缩聚过程控制pH=7．0～9．0之间；随着油水比的增大以及缩聚反应中pH值的降低，微球的粒径增大，分布变宽。     

溶菌酶降解壳聚糖条件的研究

研究了溶茵酶对壳聚糖的降解条件，结果表明：脱乙酰度约70％的壳聚糖较易被溶菌酶水解；水解反应的最适温度为55℃、pH值为4．0，低速摇床振荡对水解有利；在壳聚糖水解初期，溶液中还原糖浓度迅速增加，0．5h后水解速率逐渐减慢，至8h后还原糖浓度的增加已很缓慢；酶解液中还原糖的生成量瞳壳聚糖及溶茵酶浓度的增加而增大，当壳聚糖溶液浓度为20mg／mL、溶茵酶浓度为2．48mg／mL时，水解6h后，还原糖的含量可达6．758mmol／L。水解6h后酶解液中还原糖浓度与壳聚糖的浓度呈线性关系。     

固定化脂肪酶的动力学研究

以壳聚糖为载体，用物理吸附固定化脂肪酶，对影响固定化过程的各种因素进行了考察，确定了最优条件，并比较了游离酶和固定化酶的最适温度、pH、酶的热稳定性以及表观Km。固定化酶水解的最适pH(pH7．0)稍低于游离酶(pH8．0)，最适温度为50℃(游离酶为40℃)。固定化酶在50℃的半衰期(0．96h)是游离酶(0．32h)的3倍，在4℃的冰箱中贮存3个月活力变化很小。     

壳聚糖的酶法降解

用壳聚糖酶降解壳聚糖,探讨了壳聚糖降解过程中温度、pH值、底物浓度和金属离子对酶促反应的影响。结果表明:酶促反应进行到5 h左右时,即可得到聚合度小于10的壳寡糖。该酶促反应的最适温度为50℃,最适pH=5.5;最适底物浓度为0.02 g/mL;金属离子Ca2+和Mg2+对酶降解有一定的促进作用,而Zn2+、Cu2+对酶降解有较强的抑制作用。该酶促反应符合米氏动力学方程,米氏常数Km=7.80 g/L,最大反应速率Vmax=7.72 g/(min.L)。     

过氧化氢在乙酸均相体系中对壳聚糖的降解

为制备分子量较低的可溶于水的壳低聚糖,研究了在乙酸均相体系中过氧化氢氧化降解壳聚糖的过程,采用凝胶渗透色谱法跟踪测定了壳聚糖氧化降解过程中分子量及其分布的变化,探索制备不同分子量壳低聚糖的适宜条件。     

β-葡萄糖苷酶水解栀子苷的工艺研究

目的：研究栀子苷元最佳制备工艺。方法：采用β-葡萄糖苷酶水解的方法将栀子苷转化为苷元，以栀子苷元转化率为指标，正交试验优化β-葡萄糖苷酶水解栀子苷的工艺。结摹：最佳水解条件为：水解介质pH4．5、反应温度50℃、酶用量9600U·ml^-1，水解时间1h，栀子苷元转化率为44．7％，纯度为97．3％。结论：选取的水解工艺条件合理、可行，栀子苷元转化率高。     

壳寡糖对神经干细胞分化的影响

目的:探讨壳聚糖的降解产物壳寡糖对神经干细胞分化的影响。方法:将壳聚糖降解为分子量1100能够溶于水的壳寡糖,然后将不同浓度的壳寡糖(0.1mg/ml,0.01mg/ml)与神经干细胞共培养12天,研究壳寡糖对神经干细胞分化的影响,对照组采用无壳寡糖培养。结果:实验组的神经干细胞分化的突起平均长度比对照组要长,表明一定浓度的壳寡糖能够促进神经干细胞的分化。结论:用壳聚糖制备人工神经移植物时,壳聚糖导管不仅在神经再生过程可起到支架,细胞依附的作用,同时其降解产物壳寡糖能够起到促进神经生长的作用,而进一步阐明壳聚糖具有多功能的生物学作用。     

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.