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)。     

中药菊花过氧化物酶酶学特性及炮制工艺的研究

目的 探讨中药菊花过氧化物酶酶学特性及炮制工艺.方法 以愈创木酚为底物,采用分光光度法测定菊花过氧化物酶的酶学特性,并比较不同加工工艺下菊花过氧化物酶学特性及总黄酮含量.结果 菊花反应时间不宜超过2 min,最适pH 7.0,最适温度36℃,100℃处理30 s后,过氧化物酶活性完全丧失.过氧化物酶催化的酶促褐变反应动力学符合米氏方程,动力学参数Km=1.58×10-2 mol/L,Vmax=14.278 U/min.四种炮制工艺比较过氧化物酶的抑制效果为水蒸汽>微波干燥>80℃热风干燥>自然阴干.分光光度计法测定样品总黄酮含量,蒸制干燥>微波干燥>80℃热风干燥>自然阴干.结论 菊花过氧化物酶适应温度范围广,20~80℃,相对耐热性好.本研究可为中药菊花炮制工艺的改善提供理论参考.     

单核细胞吞噬细胞脂加氧酶酶促反应动力学的研究

采用10.000×g 离心细胞上清,对脂加氧酶的酶促反应动力学进行研究。结果表明,以亚油酸作为酶促反应底物,酶活性在1。5min 达到最大,其 km(app)=61.1μM;活性的最适 pH 在8.3附近,最适温度为25～30℃;Mg~(2+)对酶活性具有促进效应,而去甲二氢愈创木酸和维生素 E 均可强烈抑制该酶活性。     

源于纤维单胞菌的聚阿拉伯糖内切酶性质的研究

目的确定源于纤维单胞菌（Cellulomonose sp．）的聚阿拉伯糖内切酶的性质。方法SDS—PAGE和凝胶层析测定相对分子质量,离子交换层析估计等电点,TLC法测定酶活力,Lineweare—Burk双倒数做图法测定酶促反应动力学特性。结果相对分子质量为45kD,等电点约为6．0,酶促反应动力学符合Michaelis—Menten动力学规律,在37℃反应条件下,米氏常数Km为2．5mg／ml,最大反应速率Vmax为0．083μmol／L·min,最适pH为8．0,pH6．0～9．0时较稳定。最适温度为40℃,在40℃以下较稳定,超过50℃时酶活力开始下降。结论确定了一种聚阿拉伯糖内切酶的性质。     

大鼠肝微粒体中有机锡抗癌化合物DBDCT的测定与酶促动力学研究

目的 建立测定大鼠肝微粒体中有机锡抗癌化合物DBDCT的方法并研究其相应的酶促动力学。方法 采用HPLC测定DBDCT在体外代谢系统中的酶促动力学,用Eadie-Hofstee法分析数据,求算酶促动力学参数Km和Vmax以及肝代谢速率Clin。结果 在体外代谢系统中,DBDCT代谢酶促动力学参数Km=159.07 μmol·L^-1,Vmax=2.813 μmol·(min·mg)^-1以及肝清除率Clin=V_max/Km=0.017 L·(min·mg)^-1。结论 此分析方法符合方法学验证要求且简单准确,可满足DBDCT体外代谢的研究。     

多聚乙二醇化f蒜酶的特性研究

采用酶活性测定及双扩散法研究了蒜酶及修饰度为53%的多聚乙二醇(PEG)化蒜酶的某些理化性质、抗原性和免疫原性及在体外和小鼠体内的活性半衰期.结果显示在75%的乙醇中,蒜酶完全失活,而PEG化蒜酶仍保持了50%的活性.蒜酶和PEG化蒜酶最适温度均为40C.与蒜酶相比,PEG化蒜酶在更宽的pH范围内具有催化活性,蒜酶的最适pH为7,而PEG化蒜酶在pH为6～7范围内均具有最强的催化活性.蒜酶与其抗血清形成明显沉淀线,而PEG化蒜酶既不与蒜酶的抗血清也不与自身的抗血清形成沉淀.在血清中PEG化蒜酶的半衰期为90 h,是蒜酶的45倍.PEG化蒜酶的小鼠体内半衰期达2.58 d,而蒜酶在小鼠体内30 min后,已测不出催化活性.多次应用PEG化蒜酶的小鼠体内,相邻两次应用的PEG化蒜酶半衰期无显著性差异.     

多聚乙二醇化蒜酶的特性研究

采用酶活性测定及双扩散法研究了蒜酶及修饰度为53％的多聚乙二醇（PEG）化蒜酶的某些理化性质、抗原性和免疫原性及体外和小鼠体内的活性半衰期。结果显示：在75％的乙醇中，蒜酶完全失活，而PEG化蒜酶仍保持了50％的活性。蒜酶和PEG化蒜酶最适温度均为40℃，与蒜酶相比，PEG化蒜酶在更宽的pH范围内具有催化活性，蒜酶的最适pH为7，而PEG化蒜酶在pH为6－7范围内均具有最强的催化活性。蒜酶与其抗血清形成明显沉淀线，而PEG化蒜酶既不与蒜酶的抗血清也不与自身的抗血清形成沉淀。在血清中PEG化蒜酶的半衰期为90h，是蒜酶的45倍。PEG化蒜酶的小鼠体内半衰期达2．58d，而蒜酶在小鼠体内30min后，已测不出催化活性。多次应用PEG化蒜酶的小鼠体内，相邻两次应用的PEG化蒜酶半衰期无显著性差异。     

纳米二氧化硅固定木瓜蛋白酶性能研究

目的：研究固定化木瓜蛋白酶的性质。方法：以纳米二氧化硅为载体,戊二醛为交联剂,制备固定化木瓜蛋白酶。研究木瓜蛋白酶的最佳固定化条件以及固定化酶的酶学性质和动力学参数。结果：固定化酶的最适反应温度70℃,最适反应pH值为7.5,酶活回收率可达61.5％。结论：固定化酶催化的活性与游离酶相比不受显著影响。     

重组腺苷蛋氨酸合成酶酶促反应条件的研究

目的：对重组腺苷蛋氨酸合成酶催化L-蛋氨酸（Met）和三磷酸腺苷（ATP）合成腺苷蛋氨酸的反应条件进行研究。方法：将重组腺苷蛋氨酸合成酶制成粗酶液,对其酶促反应条件进行研究和优化,摸索反应的最适pH值、最适反应时间及最适酶量,解决产物抑制问题和产物分解问题。根据试验摸索的条件进行450L生物反应罐的中试放大。结果：重组腺苷蛋氨酸合成酶催化Met和ATP合成的反应最适pH值为7．0,反应时间为8h,选择硼酸钠-硫酸缓冲液作为反应的缓冲系统,确定了反应液中酶液的最佳比例为1：10,解决产物抑制问题的对甲苯磺酸钠的用量为9％。将镁离子和钾离子的盐酸盐形式改为硫酸盐形式,从而保证了最小限度的产物分解。中试放大结果：三批收率分别达到86．8％、87．1％和88．4％。结论：建立了重组腺苷蛋氨酸合成酶酶促反应的方法,为酶促法合成腺苷蛋氨酸大规模生产奠定了基础。     

酶解牛肉工艺的研究

目的 研究木瓜蛋白酶和风味酶对牛肉进行分步酶解的最佳工艺参数.方法 本实验以木瓜蛋白酶和风味酶为水解酶对牛肉进行分步酶解,在单因素的基础上采用了正交试验对水解条件进行优化.结果 先用木瓜蛋白酶在加酶量为0.1%、料液比为3:1、温度为65 ℃、pH=7.0的条件下酶解1 h,再用风味酶在加酶量为0.4%、温度为55 ℃、pH=6.0的条件下酶解5h.结论 在此方法 下的牛肉水解物经美拉德反应生成的反应物肉香味更加浓郁,游离氨基酸含量较高.     

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.     

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.     

Scientific principles and rigorous processes should be followed in developing clinical guidelines for therapeutic interventions of integrative medicine

A clinical guideline for the therapeutic interventions of integrative medicine may be defined as a written document which states a series of recommendations on therapeutic interventions of integrative medicine for a special disease or condition. The guideline may provide assistance to medical professionals in making clinical decisions aimed at improving the clinical outcome of patients and reducing the costs of medical care（~＇4~. Recommendations issued by a guideline should be based on the best available evidence in both Western and Chinese medicine. For fulfilling this purpose, the development of clinical guidelines for therapeutic interventions in the field of integrative medicine should follow scientific principles and undergo a rigorous processes.