医学物理学实验教学——测量液体表面张力系数的一种简易方法

目的：在医学物理学实验教学中,设计性实验内容的不确定性,需要实验方法的多样性,需要相关仪器设备的多样性,而各医学院校在医学物理学实验设备的投入上都不多,那我们如何立足现有仪器设备,自己动手,勇于创新,对其从新组合．从而保证设计性实验顺利完成,进行了有益的尝试。方法：立足现有仪器设备,用弹簧、读数显微镜代替焦利称．采用拉脱法和用一个新的测量液体表面张力系数的方法一相对法测量,使液体表面张力系数随浓度变化的研究获得了满意的结果。结果：该实验具有操作简单,待测量少,结果明显的特点,为表面张力系数的测量提供了一种简易可行的方法。结论：在现有仪器设备条件下,通过我们摸索、创新,可以组合出新设备,找到实验的新方法,保证医学物理学实验教学的顺利进行。     

Serum proteomic changes in adults with obstructive sleep apnoea

To examine whether differentially expressed proteins are present in the serum of patients with obstructive sleep apnoea (OSA), iTRAQ techniques (isobaric tags for relative and absolute quantification) were employed in a prospective study. Individuals were assigned to either a non‐OSA control group (apnoea–hypopnoea index, AHI <5) or an OSA group (AHI ≥5). Blood samples were collected, aliquoted and frozen at ?80 °C. Protein digestion and tagging with iTRAQ4plex^® and mass spectrometry analysis was then performed (MALDI TOF/TOF). Ten male subjects were included in the control group (age = 45 ± 9.7 years) and 30 male patients in the OSA group (age = 45 ± 10.7 years), the latter being then subdivided into three severity groups. A total of 103 proteins were identified with differential levels between patients with OSA and controls. Of these, 11 proteins were underexpressed and 19 were overexpressed in patients with OSA. C4BPA and thrombospondin were underexpressed in all three OSA severity groups. Among the overexpressed proteins, 13 were overexpressed in the mild OSA group, seven in the moderate group and five in the severe group. Analysis of interactions between the identified proteins revealed that protein alterations in OSA are primarily associated with derangements in lipid and vascular metabolic pathways. This study provides initial evidence that differential protein expression occurs in adults with OSA, and that such proteins change according to disease severity, and appear to primarily involve lipid and vascular metabolic pathways.     

Orexin A decreases lipid peroxidation and apoptosis in a novel hypothalamic cell model

Current data support the idea that hypothalamic neuropeptide orexin A (OxA; hypocretin 1) mediates resistance to high fat diet-induced obesity. We previously demonstrated that OxA elevates spontaneous physical activity (SPA), that rodents with high SPA have higher endogenous orexin sensitivity, and that OxA-induced SPA contributes to obesity resistance in rodents. Recent reports show that OxA can confer neuroprotection against ischemic damage, and may decrease lipid peroxidation. This is noteworthy as independent lines of evidence indicate that diets high in saturated fats can decrease SPA, increase hypothalamic apoptosis, and lead to obesity. Together data suggest OxA may protect against obesity both by inducing SPA and by modulation of anti-apoptotic mechanisms. While OxA effects on SPA are well characterized, little is known about the short- and long-term effects of hypothalamic OxA signaling on intracellular neuronal metabolic status, or the physiological relevance of such signaling to SPA. To address this issue, we evaluated the neuroprotective effects of OxA in a novel immortalized primary embryonic rat hypothalamic cell line. We demonstrate for the first time that OxA increases cell viability during hydrogen peroxide challenge, decreases hydrogen peroxide-induced lipid peroxidative stress, and decreases caspase 3/7 induced apoptosis in an in vitro hypothalamic model. Our data support the hypothesis that OxA may promote obesity resistance both by increasing SPA, and by influencing survival of OxA-responsive hypothalamic neurons. Further identification of the individual mediators of the anti-apoptotic and peroxidative effects of OxA on target neurons could lead to therapies designed to maintain elevated SPA and increase obesity resistance.     

Association of IL8 -251A/T, IL12B -1188A/C and TNF-α -238A/G polymorphisms with Tourette syndrome in a family-based association study in a Chinese Han population

An earlier study indicated a possible relationship between Tourette syndrome (TS) and the cytokines. To explore this further, we analyzed the association of the polymorphisms, IL8 -251A/T, IL12B -1188A/C and TNF-α -238A/G, in the IL8, IL12B and TNF-α cytokine genes with TS in a Chinese Han population. A total of 108 patients diagnosed with TS and their parents were recruited for the study. The genetic contributions of the IL8 -251A/T, IL12B -1188A/C, and TNF-α -238A/G polymorphisms were evaluated using polymerase chain reaction and restriction enzyme digestion (PCR-RFLP) and haplotype relative risk (HRR) and transmission disequilibrium test (TDT) statistics. Our results revealed no significant associations between the IL8 -251A/T, IL12B -1188A/C and TNF-α -238A/G polymorphisms and TS (for IL8 -251A/T, TDT=0.418, df=1, P=0.518; HRR=2.17, X(2)=3.000, P=0.083, 95%CI: 0.900-5.230; for IL12B -1188A/C, TDT=1.131, df=1, P=0.288; HRR=1.27, X(2)=0.35, P=0.549, 95%CI: 0.580-2.790; for TNF-α -238A/G, TDT=2.793, df=1, P=0.095; HRR=0.27, X(2)=2.90, P=0.089, 95%CI: 0.061-1.217). This result was confirmed using haplotype-based haplotype relative risk (HHRR) which allows the two alleles in each genotype to be considered separately. Our data suggests that the IL-8 -251A/T, IL-12B -1188A/C and TNF-α -238A/G polymorphisms may not be associated with susceptibility to TS in the Chinese Han population studied. However, these results need to be replicated using larger datasets collected from different populations.     

N-acetyl cysteine restores brain glutathione loss in combined 2-cyclohexene-1-one and d-amphetamine-treated rats: relevance to schizophrenia and bipolar disorder

Oxidative stress and reduced brain levels of glutathione have been implicated in schizophrenia and bipolar disorder. N-acetyl cysteine (NAC) is a precursor of glutathione and has additional effects on glutamate neurotransmission, neurogenesis and inflammation. While NAC treatment has shown benefits in both schizophrenia and bipolar disorder, the mechanisms of action are largely unknown. Similarly, the interaction between oxidative stress and altered dopaminergic activities in psychiatric illness is not yet characterized. This study investigated the capacity of NAC in restoring brain glutathione depletion in rats that received 2-cyclohexene-1-one (CHX, 75 mg/kg), d-amphetamine (2.5mg/kg) or both. CHX, but not amphetamine, induced significant depletion of glutathione levels in the striatum and frontal cortex. Glutathione depletion was reversed by NAC (1000 mg/kg) in saline-treated and amphetamine-treated (frontal cortex only) rats. While NAC was shown to be beneficial in this model, the lack of additional glutathione depletion by amphetamine in combination with CHX does not support a summative interaction between oxidative stress and altered dopamine transmission.     

镓合金的细胞毒性评价

细胞性是评价生物材料生物相容性优劣的一个重要指标。对新研制的镓合金用Ｌ－９２９小鼠成纤维细胞,采用改进的体外细胞相对增殖度法。对其细胞毒性进行了评价。     

基于相对风险的肿瘤基因差异表达分析

目的寻找与肿瘤相关的基因诊疗中差异表达基因提取的方法。方法将基因表达谱数据进行预处理,采用相对风险方法筛选出差异表达基因特征子集,计算其样本间距离,然后对特征基因加权排序和过滤冗余基因,最后应用分类器对卵巢癌基因数据集进行分析,测试该方法的有效性。结果选取20维特征基因,进行分类测试,当特征基因为3～5、7和12～20维时,分类准确率可以达到100%,假阳性率可以达到0,表现出较好的可靠性,能够有效地将2个样本类型分开。结论经分类器测试证明,分类精度高,效果优于使用传统的基因差异表达分析方法。     

Multi-level basis selection of wavelet packet decomposition tree for heart sound classification

Wavelet packet transform decomposes a signal into a set of orthonormal bases (nodes) and provides opportunities to select an appropriate set of these bases for feature extraction. In this paper, multi-level basis selection (MLBS) is proposed to preserve the most informative bases of a wavelet packet decomposition tree through removing less informative bases by applying three exclusion criteria: frequency range, noise frequency, and energy threshold. MLBS achieved an accuracy of 97.56% for classifying normal heart sound, aortic stenosis, mitral regurgitation, and aortic regurgitation. MLBS is a promising basis selection to be suggested for signals with a small range of frequencies.     

中年知识分子心理健康影响因素的广义相对危险度模型

目的：研究影响中年知识分子心理健康的危险因素及模式。方法：对１５０３名中年知识分子进行ＳＣＬ－９０测试和影响因素的调查,用广州相对危险度模型分析危险因素的作用大小及相互作用形式。结果：６．９％的中年知识分子（男性为６．１％,女性为７．８％）有心理健康问题,按作用大小危险因素依次是离婚或丧偶、接触毒物或噪声、缺少业余爱好、工作时间延长、患慢性病,多因素模型趋向于超相乘结构、危险因素间联合作用趋向于超     

鼻腔内机械振荡刺激对健康人群静息态脑电图相对功率及有效连接的影响

鼻腔内机械振荡刺激(iMVS)是一种新型的无创神经刺激技术,可提升边缘系统内在功能活性从而改善自主神经平衡.通过分析iMVS对健康人群脑电图(EEG)相对功率以及EEG有效连接的影响,探索iMVS的神经生理机制.将22名健康成年被试随机均分为刺激组与对照组,并对11名刺激组被试两侧鼻腔各进行10 min的iMVS,11...