聚合酶链反应-单链构象多态性分析在家族性高胆固醇血症研究中的应用

目的：探讨聚合酶链反应－单链构象多态性分析（polymerase chain reaction-single strand conformation polymorphism，PCR－SSCP）在家族性高胆固醇血症（familial hypercholesterolemia,FH)研究中的应用价值。方法：提取FH患者外周血基因组DNA，进行PCR－SSCP及DNA序列分析。结果：对1家2例临床诊断为FH的患儿及其父母从基因水平明确了诊断。LDL受体基因突变是位于第6外显子的移框突变，结论：PCR－SSCCP可以从基因水平对FH患者明确诊断，并可对先证者家族系成员早期诊断，以便提供咨询和指导。     

高血压脑梗死患者血管紧张素转换酶基因多态性分析

目的 探讨血管紧张素转换酶（ACE）基因多态性与高血压脑梗死发病的关系。方法 采用聚合酶链反应技术（PCR），对158名健康成人和50例原发性高血压、90例高血压脑梗死患者ACE基因插入／缺失（I／D）多态性进行检测，并且非条件Logistic回归筛选出与高血压脑梗死发病相关的因素。结果 DD基因型、D等位基因频率高血压脑梗死组高于正常对照组（P＜0.01)和高血压组（P＜0.05)。发病年龄在60岁以上者，DD基因型、D等位基因频率高血压脑梗死组高于高血压组和正常对照组（P＜0.05、P＜0.01)；而60岁以下起病者，DD基因型、D等位基因频率高血压脑梗死组则与高血压组、正常对照组无差别（均P＞0.05)，而高血压组D等位基因频率高于正常对照组（P＜0.05)。ACE DD基因型是高血压脑梗死独立的危险因素，发现高血压时间是高血压脑梗死的保护因素。结论 ACE DD基因型携带者发生高血压脑梗死的危险性增高，早期发现及治疗高血压对降低高血压患者脑梗死发生有意义。     

Neuromuscular transmission as a function of motor unit size in patients with prior poliomyelitis.

We studied neuromuscular transmission in 16 patients with prior poliomyelitis by measuring single fiber electromyographic (SFEMG) jitter. This was compared with 3 indirect methods of assessing reinnervation: SFEMG fiber density, macro EMG, and the presence of fiber type grouping on muscle biopsy. In patients with acute poliomyelitis before the age of 10, there was a positive correlation between the extent of neuromuscular transmission impairment, demonstrated by increased SFEMG jitter, and the enlargement of the motor unit, as indicated by increased fiber density, increased macro EMG signals, and fiber type grouping on muscle biopsy. However, there was no correlation between any of these parameters and the presence or absence of new symptoms of weakness. These findings suggest that impaired neuromuscular transmission is most common in patients with prior poliomyelitis whose motor units have been maximally enlarged by axonal sprouting, but is independent of the presence or absence of new symptoms of weakness.     

2型糖尿病患者载脂蛋白E基因多态性的研究

目的：探讨中国人2型糖尿病患者载脂蛋白E（apoE)基因多态性及其与血脂和载脂蛋白水平的关系。方法：采用聚合酶链反应－限制性酶切片段长度多态性法，分别对74例2型糖尿病患者及191例血脂、血糖正常且无糖尿病史者的apoE基因型、空腹血脂及载脂蛋白AI、AⅡ、B100、CⅡ、CⅢ及E进行全面分析。结果：2型糖尿病患者的血清甘油三酯（TG）、总胆固醇（TC），低密度脂蛋白胆固醇（LDLC），非高密度脂蛋白胆固醇（nHDLC),载脂蛋白B100、CⅡ、CⅢ、E水平及TG／HDLC比值较对照组显著升高（P＜0．01）；血清高密度脂蛋白胆固醇（HDLC），apoE/apoCⅢ比值显著降低（P＜0．05）。2型糖尿病组与对照组apoE基因频率分布无显著性差异（P＞0．05）。携带ε2等位基因组血清TG／HDLC比值较E3／3基因型显著降低；而携带ε4等位基因组血清apoAⅡ水平较E3／3基因型及携带ε2等位基因组显著升高（P＜0．001）。结论：2型糖尿病患者apoE基因多态性与血TG／HDLC及apoAⅡ有一定关联。     

均一吸收体中SPECT重建多解性的探讨

通过对重建图像噪声特性的分析，间接证明ＳＰＥＣＴ的解具有多样性。分别用ＴｒｅｔｉａｋＭｅｔｚ、Ｇｕｌｂｅｒｇ、富谷武浩等推导的３种等价重建方法和Ｂｅｌｉｎｉ等推导的重建方法，经计算机模拟重建衰减均匀分布的图像，先预置相同的重建图像的空间分辨率，再比较它们的噪声特性。两种方法重建图像的噪声分布：前者近图像边缘时增大，而后者减小，从而间接证明在假定均匀衰减条件下，ＳＰＥＣＴ的重建有多解性。     

Left ventricular ejection fraction and volumes from gated single photon emission tomographic myocardial perfusion images: Comparison between two algorithms working in three-dimensional space

Objective. Two different algorithms operating in three-dimensional space, one dependent on surface detection developed at Cedars-Sinai Medical Center (CS) and another dependent on statistical parameters and developed at Stanford University Medical School (SU), were compared in the same patients to assess the left ventricular volumes and the left ventricular ejection fractions (LVEFs) from gated single-photon emission tomography (SPECT) myocardial perfusion images.Methods. Perfusion SPECT images gated in eight time bins were recorded in 40 patients with coronary artery disease 60 minutes after the injection of 925 MBq^99mTc-labeled tetrofosmin at rest. The LVEF values were validated against planar gated ^99mTc-labeled blood pool studies (ERNA).Results. The software success rates were 95% (38/40 patients) for CS and 100% for SU. Agreement between LVEFs measured with CS and SU and agreement between both methods and ERNA were excellent (LVEF_CS = 0.89LVEF_SU + 6.21, r = 0.93; LVEF_SU = 0.92LVEF_ERNA + 0.99, r = 0.94; and LVEF_CS = 0.88LVEF_ERNA + 4.58, r = 0.93). Bland-Altman plots showed that differences between LVEFs from SU and CS and from ERNA were similar across a wide range (20% to 80%) of LVEF values. No relationship between these differences and the severity of perfusion defects was observed. For left ventricular volumes, linear regression analysis showed an excellent correlation between both methods (end-diastolic volume R = 0.97 end-systolic volume R = 0.98), but systematically higher values were obtained with SU (p = 0.013).Conclusion. Measurements of LVEF obtained with CS and SU correspond well with those from the standard, ERNA, even in patients with severe perfusion defects. A close relationship is observed between SU and CS when left ventricular volumes are considered. Measurements of LVEF (and left ventricular volumes) should be considered as an integral part of myocardial perfusion studies whenever possible.     

血管紧张素转换酶基因多态性与冠心病关系的研究

目的：探讨血管紧张素转换酶（ACE）基因多态性与冠心病及冠状动脉病变支数的关系。方法：应用PCR扩增ACE基因的16内含子上的287bp插入／缺失片段，确定ACE基因型。在各组间进行基因型和等位基因频率的比较，采用多因素逐步logistic回归分析ACE的DD基因型及其他易患因素对冠心病的作用。用冠状动脉造影标准确诊冠心病。结果：（1）冠心病组ACE的DD基因型和D等位基因频率均高于对照组（x^2分别为16．04，16．08；P均＜0．01）。D等位基因与冠心病的关联性较高（隐性作用时OR＝2．15，P＜0．01，显性作用时OR＝2．84，P＜0．01）。（2）冠状动脉单支，双支，三支病变组之间，ACE基因型分布和D等位基因频率均一致（x^2分别为1．50，1．06，P均＞0．05）。（3）多因素逐步logistic回归分析，排除公认的冠心病危险因素后，ACE的DD基因型仍是冠心病的危险因素。结论：（1）ACE基因多态性与冠心病有相关性；（2）ACE基因型分布和D等位基因频率与冠状动脉病变支数无关；（3）ACE的DD基因型是冠心病的独立危险因素。     

SLE小鼠高IgG血症Fcgr2b基因序列分析

目的: 测定系统性红斑狼疮(SLE)小鼠模型-NZB/WF1双亲NZB,NZW小鼠 Fcgr2b基因启动子区核酸序列,明确Fcgr2b基因启动子区的突变性质.方法:扩增NZB,NZW小鼠Fcgr2b基因启动子DNA进行核酸序列分析.采用ELISA法测定、比较(NZB×NZW )F1×NZW回交小鼠Fcgr2b基因B/W型与W/W型组间血清总IgG 水平.结果:NZB小鼠Fcgr2b基因启动子区与正常鼠Balb/C相比存在2个部位碱基缺失,分别为13 bp及3 bp.NZW小鼠除有3个碱基置换外,与Balb/C鼠该基因启动子区序列相同.回交小鼠Fcgr2b基因B/W型组血清总 IgG水平明显高于W/W型组(P<0.0001).结论:NZB小鼠Fcgr2b基因启动子区存在碱基缺失,且该缺失突变可能与血清总IgG水平升高有关.     

儿茶酚-邻-甲基转移酶基因多态性与强迫症

目的：探索儿茶酚-邻-甲基转移酶(COMT)基因多态性同强迫症临床特征的关系。方法：采用聚合酶链反应扩增技术与限制性片段长度多态(PCR-RFLP)测定120例强迫症(OCD)患者和130例健康对照者的基因型；根据Yale-Brown强迫量表评分将强迫症划分亚型。结果：强迫症患者COMT基因型与等位基因分布与健康对照者之间无显著差异；强迫行为组与强迫思想组的COMT基因型分布存在差异；G／A基因型多见于强迫行为组。结论：COMT基因多态可能对强迫症的发病没有直接的作用，但G／A基因型可能对症状是否表现为强迫动作有一定的影响。