CT导引下胸部病变穿刺活检不同方法的临床探讨

目的探讨胸部病变穿刺活检联合同轴针吸对提高阳性率减少并发症的价值。方法回顾性分析CT导引下106例胸部病变三种不同穿刺方法的阳性率及并发症。结果单纯针吸组32例,检出恶性病变23例,良性4例,阳性率为84.3%,并发症为15.6%;单纯活检组27例,检出恶性病变15例,良性7例,阳性率为81.5%,并发症为48.1%;活检同轴针吸组47例,检出恶性病变28例,良性15例,阳性率91.5%,并发症为29.7%。结论活检联合同轴针吸是提高阳性率减少并发症的较好的活检方法,它既弥补了活检的缺点,又集中了针吸的优点,是值得推广的活检方法。     

机械振动的成骨效应研究进展

应力是骨形成的“指导性”因素。其机制是近十年来骨科学、生物医学工程及康复医学领域的研究热点。机械振动是力学刺激形式之一。诸多研究表明：振动具有显著的成骨效应,其在骨质疏松的治疗中将会有广阔的应用前景。但是,现有相关研究中,具有成骨效应的振动频率、强度等参数并不一致,尤其是振动的成骨机制不明,相关报道极少,本文对其作一论述,可为更系统、深入地研究及其在临床中的应用提供理论基础。     

手术后病人应用自控镇痛方法并发症的护理

病人自控镇痛方法（PCA）因其特殊优点，近年来得到了广泛的推广。我科自2006年6月-2006年10月推广使用PCA以来，共给300例硬膜外麻醉手术后病人使用PCA，临床效果满意。但仍有少数病人出现1种或2种并发症。现将并发症的护理报告如下。     

Regional left atrial voltage in patients with atrial fibrillation

BACKGROUND: Regional differences in fibrosis, particularly related to the posterior wall and septum, may be important in atrial fibrillation (AF). Using electroanatomic mapping, voltage can be used as a measure of fibrosis. OBJECTIVES: The purpose of this study was to determine if patients with AF have disproportionately lower voltage in the septal and posterior walls of the left atrium. METHODS: Sinus rhythm left atrial electroanatomic maps were used in serial patients presenting for left atrial ablation of AF (8-mm tip). Patients undergoing left atrial mapping for focal atrial tachycardia (AT) were used as a comparison group (4-mm tip). Animal experiments were performed to assess the influence of ablation catheter tip size on voltage amplitude. RESULTS: The posterior and septal walls exhibited the lowest voltages in both groups. Compared with the anterior wall, there was a 3.78-fold greater odds of finding a low-voltage point (<0.5 mV) in the septum (P <.001) and a 3.37-fold greater odds of finding a low-voltage point in the posterior wall (P <.001) in the AF patients; the proportion of low-voltage points by region were not significantly different in the AT group. In the animal model, the mean voltage obtained from an 8-mm ablation catheter was significantly higher (0.30 +/- 0.17 mV) than that obtained from the same points using a 4-mm catheter (0.22 +/- 0.17, P = .05). CONCLUSION: Regional differences in voltage are present in patients with atrial arrhythmias, with AF patients exhibiting significantly more low-voltage areas in the septum and posterior walls.     

Nurr1基因转染人脐血间充质干细胞诱导分化为多巴胺能神经元的实验研究

目的探讨外源性Nurrl基因修饰的人脐血间充质干细胞在基因重组成纤维细胞生长因子-8(FGF8)和音猬因子(Shh)诱导下体外分化为多巴胺能神经元的情况。方法间充质干细胞被随机分为A组(对照组)、B组(Nurrl组)、C组(FGF8+Shh组)及D组(Nurrl+FGF8+Shh),采用脂质体法将pcDNA3.1-Ntrr1转染B、D组间充质干细胞,Western blot观察Nurr1基因表达情况,并在神经元条件培养液中进行增殖培养和诱导分化,间接免疫荧光染色法鉴定细胞性质,高效液相色谱法测定多巴胺含量。结果Western blot结果显示转染后Nurr1蛋白表达明显增高。A组和B组未发现酪氨酸羟化酶(TH)阳性细胞,而C组和D组TH阳性细胞分别为10．12％±2．65％及25．36％±3．13％,多巴胺含量分别为(43．6±2．1)nmol／L及(83．2±3．5)nmol／L,差异均有显著性意义(P< 0．01)。结论人脐血间充质干细胞在FGF8和Shh诱导下可以分化为多巴胺能神经元,外源性Nurr1基因修饰后,分化为多巴胺能神经元的数量增加。     

Performance measurement of the microPET focus 120 scanner.

The microPET Focus 120 scanner is a third-generation animal PET scanner dedicated to rodent imaging. Here, we report the results of scanner performance testing. METHODS: A (68)Ge point source was used to measure energy resolution, which was determined for each crystal and averaged. Spatial resolution was measured using a (22)Na point source with a nominal size of 0.25 mm at the system center and various off-center positions. Absolute sensitivity without attenuation was determined by extrapolating the data measured using an (18)F line source and multiple layers of absorbers. Scatter fraction and counting rate performance were measured using 2 different cylindric phantoms simulating rat and mouse bodies. Sensitivity, scatter fraction, and noise equivalent counting rate (NECR) experiments were repeated under 4 different conditions (energy window, 250 approximately 750 keV or 350 approximately 650 keV; coincidence window, 6 or 10 ns). A performance phantom with hot-rod inserts of various sizes was scanned, and several animal studies were also performed. RESULTS: Energy resolution at a 511-keV photopeak was 18.3% on average. Radial, tangential, and axial resolution of images reconstructed with the Fourier rebinning (FORE) and filtered backprojection (FBP) algorithms were 1.18 (radial), 1.13 (tangential), and 1.45 mm full width at half maximum (FWHM) (axial) at center and 2.35 (radial), 1.66 (tangential), and 2.00 mm FWHM (axial) at a radial offset of 2 cm. Absolute sensitivities at transaxial and axial centers were 7.0% (250 approximately 750 keV, 10 ns), 6.7% (250 approximately 750 keV, 6 ns), 4.0% (350 approximately 650 keV, 10 ns), and 3.8% (350 approximately 650 keV, 6 ns). Scatter fractions were 15.9% (mouse phantom) and 35.0% (rat phantom) for 250 approximately 750 keV and 6 ns. Peak NECR was 869 kcps at 3,242 kBq/mL (mouse phantom) and 228 kcps at 290 kBq/mL (rat phantom) at 250 approximately 750 keV and 6 ns. Hot-rod inserts of 1.6-mm diameter were clearly identified, and animal studies illustrated the feasibility of this system for studies of whole rodents and mid-sized animal brains. CONCLUSION: The results of this independent field test showed the improved physical characteristics of the F120 scanner over the previous microPET series systems. This system will be useful for imaging studies on small rodents and brains of larger animals.     

MR血管成像在诊断下肢深静脉血栓形成中的价值并与DSA对照研究

目的探讨下肢深静脉血栓形成MR血管成像（MRA）的临床价值。方法对30例怀疑下肢深静脉血栓形成的患者进行了MRA和DSA检查，MRA采用二维时间飞越法（2DTOF）。对MRA与DSA表现进行对照分析。结果下肢深静脉血栓形成的MRA表现有1静脉充盈缺损（14例）、静脉闭塞和中断（8例）、静脉再通（3例）、侧支循环形成（25例）。以DSA为标准，MRA诊断出所有病变，但有1例假阳性。结论MRA作为无创性检查，是诊断下肢深静脉血栓有效的检查方法之一。     

老年及儿童外科病人输血治疗的特殊问题

严格掌握输血适应证已成为临床所共识。为提高临床用血的安全性，老年及儿童外科病人作为特殊群体，在输血治疗中的特殊性也应引起重视。