有氧运动对ApoE基因缺陷小鼠脂肪组织脂联素mRNA表达的影响

目的:探讨运动对ApoE基因缺陷小鼠脂肪组织脂联素mRNA表达及其防治动脉粥样硬化(AS)的作用机理。方法:20只8周龄雄性ApoE基因缺陷小鼠随机分为安静组(C,10只)和运动组(E,10只)。两组小鼠均饲以高脂膳食饲料,C组不训练,E组进行14周跑台运动,前6周由10m/min×30min逐渐递增至13m/min×60min,后8周稳定在13m/min×60min,跑台坡度为0,每周5次。14周末取材比较两组小鼠体重、内脏脂肪重量及脂体比,观察两组小鼠主动脉病理变化,检测比较其脂肪组织脂联素mRNA表达水平、血清脂联素水平及血脂水平。结果:与C组相比,E组小鼠AS斑块着色区域较小;E组小鼠脂肪组织脂联素mRNA表达水平显著高于C组(P<0.05),其血清脂联素含量也显著高于C组(P<0.01)。两组小鼠血清TC、TG、LDL、HDL水平均无显著性差异。结论:14周有氧跑台运动显著提高了小鼠脂肪组织脂联素mRNA表达及血清脂联素水平,这可能是有氧运动防治AS的重要机制之一。     

Assessment of thoracic aortic elasticity: a preliminary study using electrocardiographically gated dual-source CT

Objectives  

To gain a new insight into the elastic properties of the thoracic aorta in patients without aortic diseases using electrocardiographically (ECG)-gated dual-source (DS) CT.     

Comparison of cellular damage response to low-dose-rate 125I seed irradiation and high-dose-rate gamma irradiation in human lung cancer cells

PurposeTo investigate the difference of cellular response between low-dose-rate (LDR) ¹²⁵I seed irradiation and high-dose-rate (HDR) γ-irradiation in human lung cancer cells.Methods and MaterialsA549 and NCI-H446 cells with or without wortmannin (WM) treatment were exposed to ¹²⁵I seeds and γ-rays, respectively. Cell survival, micronuclei (MN) formation, and the expressions of Ku70/Ku80 proteins were measured.ResultsThere was a strong negative correlation between survival and MN formation for both irradiations, and the MN inductions of NCI-H446 were about twofolds of those of A549, and the survival of NCI-H446 was lower than that of A549, indicating the radiosensitivity of NCI-H446 cells was greater than that of A549 cells. Interestingly, at 4-Gy radiation, NCI-H446 cells were more sensitive to LDR irradiation than HDR irradiation. WM treatment enhanced the radiosensitivity of A549 cells evenly to ¹²⁵I seed and γ-irradiation, but this treatment led NCI-H446 cells to be more sensitive to LDR ¹²⁵I. Further results revealed that the expression of phosphorylated Ku80 protein was enhanced in irradiated A549, but in contrast, it was markedly decreased in NCI-H446 cells after 4-Gy LDR ¹²⁵I irradiation as that compared with γ-irradiated and nonirradiated cells.ConclusionNCI-H446 cells were more sensitive to LDR ¹²⁵I irradiation than HDR irradiation, and this sensitivity could be further enhanced by WM treatment. But no obvious differences of cellular response to both irradiations were observed in A549. Ku as molecular markers together with cell proliferation rate can be used to predict the radiosensitivity of tumor cells to LDR ¹²⁵I seed irradiation.     

Sacrococcygeal teratoma: computed tomography evaluation

Axial computed tomography, as well as direct sagittal computed tomography in some cases, was used to evaluate five cases of sacrococcygeal tumors, and the findings are presented. Computed tomography greatly assisted in making a correct preoperative diagnosis and in delineating the extent of the tumors. Direct sagittal scans readily staged these tumors, whereas axial scans revealed extension in the transverse plane, especially for intraspinal extension.     

双源CT冠状动脉造影的初步研究

目的 探讨双源CT在冠状动脉造影中的临床应用.方法 51例患者同时行双源CT冠状动脉血管造影(DSCTA)及选择性冠状动脉血管造影(CAG) 检查,分析DSCTA的敏感性、特异性及准确率.结果 51例患者[平均心率(77.7±5.8)次/min]均成功完成了双源CT冠状动脉血管造影,并清晰显示冠状动脉各主干及部分分支,51例患者的166支冠状动脉伴有不同程度的狭窄或闭塞,150支冠状动脉狭窄程度与CAG诊断结果相同,得出DSCTA的敏感性、特异性、阳性预测值、阴性预测值及准确率分别为100%,90%,90.4%,100%,94.8%.结论 双源CT对冠状动脉疾病的诊断准确率接近选择性冠状动脉造影,是一种准确可靠的检查方法.     

心脏良性非粘液瘤性肿瘤的电子束CT诊断

目的：探讨电子束ＣＴ（ＥＢＣＴ）在心脏良性非粘液瘤性肿瘤诊断中的价值。方法：对１９９５－ ０７～１９９９－ ０２,经ＥＢＣＴ检查并手术、病理证实的７ 例心脏良性非粘液瘤性肿瘤的ＥＢＣＴ、超声心动图结果与手术、病理所见进行回顾性分析。７个病例,男性４例（５７．１％ ）,女性３例（４２．９％ ）,年龄从５个月至４２岁,平均２１．６岁。所有病例同时行单层增强和电影序列。结果：７例心脏非粘液性良性肿瘤,包括２例浸润性脂肪瘤,２ 例纤维瘤,１例横纹肌瘤,１例淋巴管瘤,１ 例间皮瘤,ＥＢＣＴ不但能够明确肿瘤的位置、附着、大小、范围、运动,而且以优良的密度分辨率,在６个病例显示肿瘤病理学特征,提示正确的病理学定性诊断,准确性为８５．７％ ;２ 个病例术后提示肺不张与胸腔积液。同组病例中,超声心动图无１例做出正确组织病理学定性。结论：ＥＢＣＴ具有优良的时间、空间和密度分辨率,在对超声心动图难以准确定性的良性非粘液瘤性肿瘤的诊断中具一定优势,同时可展示邻近病变情况     

乙型肝炎病毒基因异质性及准种特点研究的临床意义

乙型肝炎病毒（HBV）基因组在慢性HBV感染的个体中存在不同的基因型（genotype)、血清型（serotype)和准种（quasispecies)等基因序列异质性（heterogeneity)的特点。HBV基因序列异质性是普遍存在的，在HBV基因组的各结构基因区、调节基因区都有异质性的特点，而且始终处在持续变化之中。HBV基因序列的异质性具有十分重要的生物医学意义。HBV准种等异质性特点的研究，使我们对于HBV全基因序列、HBV基因突变的规律、HBV抗药性的遗传学基础，甚至导致肝细胞恶性转化的分子生物学机制等都有了全新的认识。准种概念的引入，使我们对于HBV基因序列异质性的认识，从单一病毒株水平提升到HBV种群的水平，是对于HBV基因遗传与变异认识的一次革命性的飞跃。     

肝癌氩氦刀冷冻治疗的CT评价

目的:评价肝癌氩氦刀冷冻治疗的临床价值。材料和方法:氩氦刀治疗48例肝脏恶性肿瘤病人。其中40例为原发性肝细胞癌,8例为转移性肝癌。术后1～4个月复查CT。结果:对<3cm的小肝癌冷冻治疗后CT检查,肿瘤完全坏死,动脉期和门静脉期病灶不强化,但对>5cm的肿瘤疗效欠佳。结论:氩氦刀冷冻治疗肝癌(特别是<3cm的小肝癌)安全有效,并发症少,但对较大的肿瘤(>5cm)并不完全适合,需结合其他疗法。     

副肝静脉成形术在Budd-Chiari综合征治疗中的应用

目的 评价副肝静脉成形术[经皮腔内血管成形术（PTA）及支架置入术]在Budd-Chiari综合征（BCS）介入治疗中的价值。方法 本组14例BCS患者均为肝静脉，副肝静脉狭窄或闭塞，主要症状和体征为腹胀，腹痛，腹水，肝脾肿大等，均接受了副肝静脉成形术，采用经股静脉或经颈静脉和经皮经副肝静脉途径开通副肝静脉的方法。结果 14例BCS开通副肝静脉均获得成功，未发生严重并发症，术后临床治愈7例，有效5例，无效2例。随访3-48个月。3例PTA后再狭窄（支架内血栓形成1例），1例术后2个月死于消化道大出血。结论 开通副肝静脉有着与开通肝静脉同等的治疗价值。易于操作，且更加安全，适应证为：（1）肝静脉和副肝静脉同时闭塞，而且肝静脉为节段性闭塞；（2）副肝静脉明显代偿性扩张，其管径大于8mm。     

Rapid electrochemical quantification of trace Hg2+ using a hairpin DNA probe and quantum dot modified screen-printed gold electrodes

Rapid, simple, sensitive and specific approaches for mercury(ii) (Hg²⁺) detection are essential for toxicology assessment, environmental protection, food analysis and human health. In this study, a ratiometric hairpin DNA probe based electrochemical biosensor, which relies on hairpin DNA probes conjugated with water-soluble and carboxyl functionalized quaternary Zn–Ag–In–S quantum dot (QD) on screen-printed gold electrodes (SPGE), referred to as the HP-QDs-SPGE electrochemical biosensor in this study, was developed for Hg²⁺ detection. Based on the “turn-off” reaction of a hairpin DNA probe binding with a mismatched target and Hg²⁺ through the formation of T–Hg²⁺–T coordination, the HP-QDs-SPGE electrochemical biosensor can rapidly quantify trace Hg²⁺ with high ultrasensitivity, specificity, repeatability and reproducibility. The conformational change of the hairpin DNA probe caused a significant decrease in electrochemical intensity, which could be used for the quantification of Hg²⁺. The linear dynamic range and high sensitivity of the HP-QDs-SPGE electrochemical biosensor for the detection of Hg²⁺ was studied in vitro, with a broad linear dynamic range of 10 pM to 1 μM and detection limits of 0.11 pM. In particular, this HP-QDs-SPGE electrochemical biosensor showed excellent selectivity toward Hg²⁺ ions in the presence of other metal ions. More importantly, this biosensor has been successfully used to detect Hg²⁺ in deionized water, tap water, groundwater and urine samples with good recovery rate and small relative standard deviations. In summary, the developed HP-QDs-SPGE electrochemical biosensor exhibited promising potential for further applications in on-site analysis.

A ratiometric hairpin DNA probe based electrochemical biosensor, which relies on hairpin DNA probes conjugated with water-soluble and carboxyl functionalized quantum dot on screen-printed gold electrodes, was developed for Hg²⁺ detection.