乙肝酶标增速剂和稳定剂的研制和应用

本文报道乙肝酶标检测中增速剂和稳定剂的研制结果。采用一定浓度化学物质(P_a和S_c)的适当配比制成增速剂稀释被检标本和酶结合物,并建立快速酶标检测法,可使试验中两次免疫学反应在60分钟内(每次30分钟)完成。比同温度下的常规法(每次1.5小时)缩短2/3时间。用快速法检测定值标本和病人血清中的乙肝标志物与常规法比较,无统计学差异,故本增速剂在乙肝酶标诊断中是可以应用的。 用一定浓度牛血清白蛋白和某些稳定酶的化学物质,配制成4种稳定剂,通过对酶结合物的保存观察,选出了稳定剂B较为理想。用该稳定剂保存酶结合物14个月(最长观察期),其活性下降仅为6.1％。     

不同冲洗方法对粪肠球菌感染根管的抗菌性研究

目的比较超声、Er,Cr：YSGG激光及Er：YAG激光辅助1%次氯酸钠（NaOCl）溶液冲洗对人离体牙根管表面粪肠球菌生物膜及根尖区不同深度牙本质小管内粪肠球菌的杀灭效果。 方法单直根管下颌前磨牙42颗,建立粪肠球菌生物膜感染的根管模型,采用随机字表法随机抽取2颗确定建成粪肠球菌生物膜感染根管模型,剩余40颗牙采用随机数字表法按随机对照原则分为5组,每组8颗。A组：5.25% NaOCl联合17%乙二胺四乙酸（EDTA）注射器冲洗;B组：0.9%氯化钠溶液注射器冲洗;C组：1% NaOCl溶液超声荡洗;D组：1% NaOCl溶液Er：YAG激光活化冲洗;E组：1% NaOCl溶液Er,Cr：YSGG激光活化冲洗。按分组进行处理后取样菌落计数,计算灭菌率。使用SPSS 17.0统计软件对实验数据进行方差齐性及正态性检验比较各组间和组内的灭菌率。 结果（1）组间比较：对根管壁表面,各组冲洗方法灭菌率比较,B组（5.74%）相似文献   

孤束核内迷走神经传入纤维与神经降压肽样神经元间的突触联系—溃变结合免疫电镜研究

用切断颈迷走神经的顺行溃变法结合免疫组化(PAP法)研究了孤束核内迷走神经传入纤维与NT样免疫反应(NT-LI)结构超微结构及其联系。发现溃变的迷走神经传入纤维终末多呈电子致密型,少量为电子透亮型;溃变的轴突终末少量地与NT-LI树突形成非对称性突触,较多的与未标记的树突或胞体形成对称性和非对称性突触;NT-LI结构可作为突触前成分或突触后成分与未标记的细胞构成对称性或非对称性突触,NT-LI结构间各存在对称性的轴-体、轴-树和树-树突触。结果表明迷走神经传入纤维可与孤束核内NT-LI细胞构成突触,但数量较少,孤束核内的NT-LI细胞可能作为迷走神经传入纤维与迷走神经背核中节前神经元或高位脑部之间联系的中间神经元的一部分,从而参与内脏、心血管活动的调节。     

蛛网膜下腔注射神经降压素对大鼠血压和心率的影响

本文研究了蛛网膜下腔注射神经降压素（ｎｅｕｒｏｔｅｎｓｉｎ，ＮＴ）对大鼠血压和心率的影响，结果表明：注射ＮＴ后血压立即下降，继而有所回升，但不及正常水平，然后再次降低，持续６０ｍｉｎ；心率无明显改变。Ｈ１受体阻断剂苯海拉明能部分阻断ＮＴ的降血压效应，Ｈ２受体阻断剂甲氰咪胍无翻转作用。注射组胺释放剂Ｃｏｍｐｏｕｎｄ４８／８０使血压下降，待血压恢复正常水平后，再注射ＮＴ，其降压效应减弱。结果提示：蛛网     

直接MR髋关节造影的临床应用

临床上慢性髋关节疼痛的病因较多,髋臼唇的损伤是引起髋关节疼痛的原因之一,易导致关节内软骨病变,并且是髋关节发生骨关节炎的先兆,有研究表明髋臼唇损伤在顽固性髋痛者中占55%[1]。常规MRI很难观察到髋臼唇及软骨结构,由于没有可靠的影像学诊断方法,诊断往往被延误。     

超声对比剂的剂量和浓度对心腔造影时间-强度曲线参数的影响

目的:探讨心腔超声对比剂的剂量及浓度对心腔造影时间强度曲线参数的影响.方法:对10条健康犬在基础状态下经股静脉分别注射1%、5%声振白蛋白注射液,剂量分别为0.04ml/kg、0.08ml/kg,于心尖四腔切面观察右心室对比剂的充盈及清除,采用拟合曲线定量分析方法获取心腔造影时间强度(TIC)曲线各项参数,并分析各项参...     

微波辐射防护剂研究现状

随着微波（频率300MHz～300GHz）技术的发展,微波在通讯、家用电器、工业和军事等领域应用越来越广泛,人受微波辐射的机会越来越多,微波对健康影响开始引起人们的重视,微波的生物损伤效应研究成为热点。近年来大量研究工作表明,微波可对生物体造成不同伤害。     

稀释对比剂注射法在64层螺旋CT冠状动脉成像中的应用研究

目的比较不同对比剂方案对冠状动脉成像的影响。方法 60例临床疑诊冠心病患者在行回顾性心电门控64-层螺旋CT冠状动脉造影检查中,根据不同对比剂方案随机分为以下3组:A组(20例)先注射对比剂,后注射生理盐水;B组(20例)先注射对比剂,后注射对比剂与盐水以3∶7比例配制的稀释液;C组(20例)先注射对比剂,后注射对比剂与盐水以1∶1比例配制的稀释液。分别测量所有患者冠状动脉左主干、左前降支、左回旋支及右冠状动脉的CT值。对获自显示冠状动脉、右心室均匀性及左心室壁的数据,利用SPSS13.0软件进行统计学分析与比较。结果在冠状动脉左主干、左前降支、左回旋支测得的CT值以及右心室均匀性显示,各组间均无显著性差异(P>0.05),然而,左心室壁的显示在A、B组之间或A、C组之间均有显著性差异(P=0.0001),在B、C组之间亦有显著性差异(P=0.0007)。结论在64层螺旋CT冠状动脉增强扫描中,稀释对比剂方案优于传统的注射方案(A组),以3∶7比例配制的稀释液(B组)为最佳方案。     

新型MR对比剂长循环超顺磁氧化铁脂质体纳米微粒的体内外实验研究

目的 评价自制新型MR对比剂:长循环超顺磁性氧化铁(superparamagnetic iron oxide,SPIO)脂质体纳米微粒的药代动力学.方法 以加入SPIO为对照组,加入长循环SPIO脂质体纳米微粒为实验组.(1)巨噬细胞的体外吞噬实验:将巨噬细胞株RAW 264.7经复苏、培养,细胞达到80%～90%融合后,以每孔2.5×105个细胞接种于培养板,对照组和实验组细胞与不同浓度药物孵化后,分别测定细胞中Fe浓度和Fe染色情况,并用析因设计的方差分析对结果进行统计学处理.(2)小鼠体内药物分布实验:C57BL/6J雄性小鼠6只,每组2只,设为空白对照组、对照组、实验组,经尾静脉分别注射生理盐水、SPIO以及长循环SPIO脂质体后牺牲动物,经病理检查观察2组药物在体内的分布情况.(3)荷肺癌裸鼠MR成像实验:建立20只BALB/c裸鼠移植型肺癌模型,分为对照组和实验组,每组10只,分别经尾静脉注入SPIO和长循环SPIO脂质体纳米微粒后行MR扫描,测量增强前后2组实验动物各时间点肝脏和肿瘤ROI的信号强度,绘制信噪比(SNR)时间动态变化曲线,采用协方差分析比较2组动物肝脏及肿瘤增强12 h 后SNR差异有无统计学意义.(4)细胞毒性实验(噻唑蓝,MTT法):检查2种药物对人肝细胞株HL-7702细胞的毒性作用,用析因设计的方差分析对结果进行统计学处理.结果 (1)巨噬细胞的体外实验:析因分析结果表明,对照组细胞内Fe含量明显高于实验组,差异有统计学意义(F=296 839.9,P=0.000).普鲁士蓝染色显示对照组巨噬细胞染色较深,实验组巨噬细胞染色较浅.(2)小鼠体内药物分布实验:对照组肝、脾、肺、肾组织内蓝染颗粒多于实验组.(3)荷肺癌裸鼠MR成像实验:平扫对照组肝脏SNR为31.47±0.56,实验组为30.89±1.41;增强扫描12 h后对照组为17.00±0.96,实验组为22.29±0.73.平扫对照组肿瘤SNR为58.41±0.61,实验组为58.44±1.08;增强扫描12 h后对照组为58.50±0.63,实验组为52.47±1.18.经协方差分析表明增强12 h后对照组肝脏SNR显著低于实验组(F=167.022,P=0.000);而实验组肿瘤 SNR显著低于对照组(F=266.106,P=0.000).(4)细胞毒性实验:随着培养液中Fe浓度的增加,HL-7702细胞生存率均有下降趋势,但析因分析结果表明,实验组药物的细胞毒性较对照组低(F=2256.204,P=0.000).结论 长循环SPIO脂质体纳米微粒在体内外均有较好的抗巨噬系统吞噬功能,在体内实现了长循环,对非网状内皮系统的肿瘤也具有良好的T2负性被动靶向强化效果;同时还降低了SPIO对细胞的毒性作用.

Abstract：

Objective To evaluate pharmacodynamics of prepared long-circulating superparamagnetic iron oxide (SPIO) liposomes. Methods Control and experimental groups were established after adding SPIO or long-circulating SPIO liposomes as agents. (1)Macrophages experiment in vitro: the RAW 264.7 macrophage cell strains were recovered, cultured and seeded in the culture plate at a density of 2.5×105 cells/well until they reached 80%-90% confluence. The intracellular Fe uptake of control and experimental group cells were quantified by Ferrozine assay after incubation with different concentrations of drugs. Factorial design analysis of variance was used as statistics method. Prussian blue staining method was used to detect staining of experimental cells.(2)Drug biodistribution in mice: C57BL/6J(n=6) were classified into blank control group (n=2), control group(n=2) and experimental group(n=2).Saline, SPIO and long circulating SPIO were injected via the tail vein in the blank control group, control group and experimental group respectively. Then distribution of drugs in the body was observed by pathological examination.(3) MR imaging of tumor-bearing nude mice: 20 BALB/c nude mice bearing lung cancer models were established and classified into control group and experimental group. After administration of drugs, all animals underwent MR scanning. Signal intensities of livers and tumors were measured, SNR-time dynamic curves were drew. Covariance analysis was used to compare post-enhanced SNR at the 12th hour. (4)Cytotoxicity studies (MTT): cytotoxicity of both drugs on human liver cell line HL-7702 was studied, and statistically analyzed using factorial design analysis of variance. Results (1) Macrophages experiment in vitro: The nanoparticle uptake by macrophage cells evaluated by ferrozine assay showed the uptake of blank SPIO was higher than long-circulating SPIO liposomes. Compared with the blank control group, there was strong blue staining in the macrophages with Prussian staining in the control group and little blue staining in the experimental group. (2) Drug biodistribution in mice: for blue stained cells composed of iron particles, the amounts in the liver, spleen, lung, kidney of the control group were more than those in the experimental group. (3) MR imaging of tumor-bearing nude mice: the non-enhanced SNR of livers and tumors in the control group and experimental group were 31.47 ± 0.56, 30.89 ± 1.41, 58.41 ± 0.61, 58.44 ± 1.08, respectively. After injecting of contrast agents, SNR of livers and tumors in the control group and experimental group were 17.00 ± 0.96, 22.29 ± 0.73, 58.50 ± 0.63, 52.47 ± 1.18, respectively. The covariance analysis showed that SNR of the livers in the control group after 12 hours was significantly lower than the experimental group (F=167.022, P=0.000); while the SNR of the tumors in the experimental group was significantly lower than the control group (F=266.106, P=0.000).(4) Cytotoxicity of nanoparticles by MTT method: the viability of HL-7702 cells tend to decrease with the increase of Fe concentration. Cytotoxicity in the long-circulating SPIO liposomes was lower than the SPIO(F=2256.204,P=0.000). Conclusions Long-circulating SPIO liposomes we prepared reveal suitable sizes, even distribution, and good anti-macrophage ability in vitro and in vivo. They have long circulation characteristic and T2 negative enhancement effect in the transplanted lung cancers, while they still maintain low cytotoxicity.