低场强磁共振尿路水成像技术及临床应用价值的初步探索

目的评价低场强(0.35T)磁共振单次激发快速自旋回波序列(SSFSE)尿路水成像(MRU)技术及其临床应用价值。材料与方法42例正常和尿路梗阻患者,在GE0.35T永磁MR成像仪上采用SSFSE进行MRU成像;38例加作2DFSE重T2WI,经最大信号强度投影(MIP)重建MRU图像。结果采用SSFSE所得MRU图像可清晰显示正常尿路,效果比2DFSE重T2WI经MIP重建所得MRU图像要佳,尿路梗阻患者均能显示梗阻部位及程度,定性诊断正确率也达84.8%。结论低场强下应用SSFSE对尿路梗阻性病变的诊断具有较大临床应用价值。     

人类β-肾上腺素受体基因的遗传多态性及其与肥胖的关系

在世界范围内,肥胖和超重的发生率正在稳步增长.过去有关候选基因的大量研究已经表明,大多数基因与人类脂肪组织中肥胖的发生相关.与人体体质量相关的40%以上的基因变异可以产生遗传差异.β-肾上腺素受体在人体能量平衡调节中扮演重要作用,交感神经系统的高度激活被认为与肥胖的发生密切相关.β-肾上腺素受体的单核苷酸多态性如β1-肾上腺素受体Gly389Arg,β2-肾上腺素受体Gln27Glu和β3-肾上腺素受体Trp64Arg已经被证明能够改变受体的功能,并与肥胖的发生有关.本文就β-肾上腺素受体的遗传多态性以及它们在肥胖发生中的作用作一综述.     

蜗神经发育不良儿童的临床特征分析

目的探讨蜗神经发育不良(cochlear nerve deficiency,CND)儿童的临床特征。方法以43例(60耳)CND患儿(4个月~10岁,平均2.6±2.8岁)为研究对象,总结分析其是否存在听力损失高危因素、影像学检查及听性脑干反应(ABR)、畸变产物耳声发射(DPOAE)、Chirp声诱发听性稳态反应(Chirp-ASSR)检测等结果。结果43例患儿中,26例(60.5%,26/43)为单侧病变,17例(39.5%,17/43)为双侧病变;仅7例患儿有听力损失高危因素。50耳(83.3%,50/60)为蜗神经缺如,10耳(16.7%,10/60)为蜗神经细小;16耳(26.7%,16/60)伴面神经细小,8耳(13.3%,8/60)伴前庭神经异常。4耳(6.7%,4/60)仅伴前庭畸形为第一组,21耳(35%,21/60)合并耳蜗畸形或同时合并前庭畸形为第二组,35耳(58.3%,35/60)不伴内耳畸形为第三组。26耳(43.3%,26/60)ABR仅见波Ⅲ以前波形分化,随后波形消失;23耳(38.3%,23/60)ABR无波形分化;11耳(18.3%,11/60)可见分化不良的波V,其反应阈值为75~100 dB nHL。24耳(40%,24/60)DPOAE或/和CM引出,且第三组CND患儿DPOAE的信噪比(SNR)值和引出率均明显高于CND合并内耳畸形的第一、二组患儿。49耳ABR最大声输出时未引出波V的CND患儿中,41耳(83.7%,41/49)Chirp-ASSR可在不同频率不同程度引出,500、1000、2000和4000 Hz Chirp-ASSR平均反应阈分别为87.14±21.33、89.27±16.09、89.37±15.85和91.10±15.77 dB corHL。结论本组CND患儿多无明确听力损失高危因素或病因,多表现为重度或极重度感音神经性聋,高发于先天性单侧感音神经性聋婴幼儿,可表现出听神经病的特征,ABR仅见波III以前波形分化,随后波形消失,Chirp-ASSR测得残余听力明显优于ABR检测结果。     

五种氯化有机物对V79细胞DNA损伤作用的研究

本文采用近年来发展的单细胞凝胶电泳试验检测了二氯甲烷、三氯甲烷、四氯化碳及一氯化酸和三氯乙酸对Ｖ７９细胞的ＤＮＡ损伤作用。结果显示：五种受试物均可引起体外培养的Ｖ７９细胞ＤＮＡ损伤,但其作用强度差异很大。其顺序为四氯化碳〉三氯甲烷〉二氯甲烷〉一氯乙酸〉三氯乙酸。该结果还提示：五种氯化有机物对Ｖ７９细胞的毒性及ＤＮＡ损伤作用的大小顺序是一致的,氯化烷基类化合物的细胞毒性及ＤＮＡ损伤作用均大于氯乙酸类     

Striatal and temporal cortical D2/D3 receptor occupancy by olanzapine and sertindole in vivo: a [123I]epidepride single photon emission tomography (SPET) study

RATIONALE: Previous work suggests clozapine preferentially targets limbic cortical dopamine systems, which could help account for its lack of extrapyramidal side effects (EPS) and superior therapeutic efficacy. OBJECTIVES: To test the hypothesis that olanzapine, a novel atypical antipsychotic drug, occupies temporal cortical D2/D3 receptors to a greater extent than striatal D2/D3 receptors in vivo. METHODS: Nine schizophrenic patients taking either olanzapine [(n=5; mean (SD) age: 32.5 (6.5) years; daily dose: 18.3 (2.6) mg] or sertindole [(n=4; mean (SD) age: 30.3 (7.4) years; daily dose: 16 (5.6) mg] were studied with [123I]epidepride ((S)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-iodo-2,3-dimethoxybenz amide) and single photon emission tomography (SPET). An estimate of [123I]epidepride 'specific binding' to D2/D3 receptors was obtained in patients and age-matched healthy volunteers. A summary measure was generated representing striatal and temporal cortical relative %D2/D3 receptor occupancy by antipsychotic drugs. Occupancy data were compared with previously studied groups of patients receiving typical antipsychotic drugs (n=12) and clozapine (n=10). RESULTS: Mean striatal and temporal cortical %D2/D3 receptor occupancy in olanzapine-treated patients was 41.3% (SD 17.9) and 82.8% (SD 4.2), respectively. Unexpectedly low levels of striatal relative %D2/D3 receptor occupancy were seen in two patients with typical antipsychotic-drug-induced movement disorder prior to switching to olanzapine. In the temporal cortex, mean D2/D3 dopamine receptor occupancy levels above 80% were seen for all antipsychotic drugs studied. CONCLUSIONS: The atypical antipsychotic drugs olanzapine and sertindole, in common with clozapine, demonstrate higher occupancy of temporal cortical than striatal D2/D3 dopamine receptors in vivo at clinically useful doses. This could help mediate their atypical clinical profile of therapeutic efficacy with few extrapyramidal side effects. Limbic selective blockade of D2/D3 dopamine receptors could be a common action of atypical antipsychotic drugs.     

Selective effect of cinnarizine on the vestibular nucleus neurons

Summary Effects of cinnarizine were studied on the lateral vestibular nucleus (LVN) and spinal trigeminal nucleus (STN) of cats anesthetized with -chloralose. Cinnarizine did not produce any obvious alterations of the field potential and spike generation of type B interneurons in STN elicited by trigeminal nerve stimulation as well as the field potential in LVN by vestibular nerve stimulation. Spike generation of monosynaptic LVN neurons elicited by the suprathreshold stimulus to the vestibular nerve was unaffected by cinnarizine up to 4 mg/kg. When the subthreshold stimulus was applied to the vestibular nerve, however, the spike number of LVN monosynaptic neurons was significantly increased after cinnarizine treatment. The enhancement of spike firing by cinnarizine upon both supra- and subthreshold stimuli to the vestibular nerve was found to be more pronounced in LVN polysynaptic neurons than monosynaptic ones. Since the effect of cinnarizine on LVN neurons was not dose-dependent, it is suggested that the enhanced responsiveness of the neurons by the drug might be due to an increase of blood flow, but not to a direct excitation of the neurons themselves.     

The atrioventricular junction in the univentricular heart: A two-dimensional echocardiographic analysis

Summary The atrioventricular junction of 40 patients with univentricular heart was evaluated by two-dimensional echocardiography. The apical 4 chamber view optimally imaged the atrioventricular junction, and allowed determination of the type of atrioventricular connection: double inlet, common atrioventricular orifice, and absent right or left atrioventricular connection. When double inlet to 1 ventricle was demonstrated, the 4 chamber view allowed immediate comparison of the form and function of the right and left atrioventricular valves. Because anomalies of the atrioventricular valves frequently complicate the univentricular heart, two-dimensional echocardiographic assessment is a most important adjunct to the preoperative investigation of these patients.     

Inhibitory effect of betahistine on polysynaptic neurons in the lateral vestibular nucleus

Summary Effects of betahistine, an antivertigo drug, were examined on the lateral vestibular nucleus (LVN) neurons of cats anesthetized with -chloralose. Spike generation of monosynaptic LVN neurons elicited by vestibular nerve stimulation remained unaffected with intravenous administration of betahistine up to 5 mg/kg and with iontophoretic application of the drug up to 200 nA. In contrast, the spike generation of polysynaptic I neurons in the LVN was dose-dependently inhibited by intravenous as well as iontophoretic application of betahistine. These results suggest that small doses of betahistine more selectively interfere with synaptic transmission in the polysynaptic I neurons than in the monosynaptic neurons.     

人类MOG1基因检测及其与青壮年猝死综合征的相关性研究

目的寻找MOG1基因的变异位点,探讨其与青壮年猝死综合征的关系。方法提取青壮年猝死综合征病例组及健康对照组的基因组DNA,采用聚合酶链式反应（PCR）方法扩增MOG1基因编码区外显子、外显子-内含子交界区以及3′侧翼区序列,直接行DNA测序以明确遗传变异类型,并进行统计学分析。结果在病例组中共检测到3个变异位点,其中2个为新发现的突变,分别为c.285G〉C（p.L95L）和c.＊4C〉T,另1个为单核苷酸多态性位点c.437＋16C〉T。在病例组和对照组中c.437＋16C〉T位点基因型分布（P=0.071）和等位基因频率（P=0.819）存在一定程度差异,但差异均无统计学意义。结论MOG1基因是否是中国人青壮年猝死综合征的易感基因还有待进一步研究。