FL联合TPO体外培养AC133+细胞表面标记的变化

目的:探讨脐血造血干/祖细胞的体外扩增.方法:免疫磁珠法分离纯化脐血AC133+细胞,在细胞因子FLT3配体、血小板生成素作用下,体外扩增,检测有核细胞扩增的倍数.采用流式细胞仪分析细胞表面标志的变化.结果:FLT3联合血小板生成素体外培养2周.有核细胞扩增(18±8)倍.CD34细胞扩增2.8倍,AC133+未获扩增,CD34细胞纯度由(56±23)%下降到(8±1)%,AC133+细胞由85%下降到(0.1±0.1)%.随着体外培养时间延长至4周,有核细胞,CD34+进一步扩增.分别扩增475倍和17倍.但细胞随之发生分化,CD34+细胞占有核细胞中的比例下降至2%,AC133+细胞消失.CD45细胞上升到1.3%.结论:FL联合TPO长期培养AC133+细胞能使CD34细胞扩增.     

miRNA-21与心血管疾病

MicroRNAs (miRNAs)是长度约22个核苷酸左右的内源性、非编码RNA.在心血管疾病状态下,如增殖性血管疾病,心脏肥大,心功不全和缺血性心脏病的心血管组织中,miRNA-21表达下调.miRNA-21在血管平滑肌细胞的增殖、凋亡,心肌细胞生长、死亡及心肌细胞纤维化方面起着重要作用,已被证实参与上述疾病发病过...     

Measurement of both left ventricular function and regional myocardial perfusion with 133Xe in dogs

A technique to measure left ventricular (LV) function and myocardial perfusion was validated in 12 dogs. ¹³³Xe in saline was injected into the left atrium (LA) or LV and two data sets were obtained using gamma camera imaging: 1) A first pass gated scan for LV function; followed by 2) Sequential images for regional myocardial perfusion. LV ejection fraction and wall motion measurements from the ¹³³Xe blood pool images were compared to ejection fraction (r=0.88, P<0.01) and wall motion (r=0.83, P<0.01) data from ^99mTc labeled blood pool scans. The perfusion measurements obtained with the ¹³³Xe method were compared to microsphere data (r=0.79, P<0.01). Measurements after LV ¹³³Xe injection were similar to data following LA injection. Thus, quantitative assessment of global LV function, regional wall motion and myocardial perfusion is possible with LA or LV ¹³³Xe injection and gamma camera imaging.     

MicroRNA-224在肝癌HepG2细胞中的表达及其靶基因的预测分析

目的 应用基因芯片技术研究microRNA-224在肝癌HepG2细胞中的表达,通过生物信息学预测其下游靶基因,并初步揭示其在肝癌发生过程中的作用.方法 利用基因芯片技术筛选得到和正常肝上皮LO2细胞比较差异表达的基因,通过生物信息学预测表达上调的microRNA-224的靶基凶,并对其靶基因进行功能注释.结果 与LO2细胞比较,microRNA-224在肝癌HepG2细胞中旱高表达.MicroRNA-224预测靶基因有264个,其多个基因涉及细胞周期、信号转导、细胞增殖、细胞分化和细胞凋亡等众多生物学过程.结论 MicroRNA-224在肝癌HepG2细胞中呈现高表达,可能间接或直接地调控其下游靶基因表达,在肝癌发生过程中起着重要的作用.     

Cesium-133: a potential reporter of the hepatic uptake of contrast agents.

NMR spectroscopy of intracellularly located (133)Cs has been used to monitor the uptake of Gd-EOB-DTPA by the isolated rat liver. As shown by (31)P spectroscopy, accumulation of (133)Cs ions in hepatocytes does not produce detectable effects on the metabolism. The hepatic internalization of Gd-EOB-DTPA was followed by the paramagnetic relaxation enhancement of the intracellular (133)Cs ions, and confirmed by parallel quantitations of Gd and Cs run by inductively coupled plasma (ICP) analysis of liver samples and aliquots of perfusate. The relaxation data significantly underestimate the Gd content, suggesting a potential compartmentation of Cs(+) and/or the contrast agent. Magn Reson Med 45:711-715, 2001.     

Absolute activity of (133)Ba by liquid scintillation coincidence counting using the 4pi(e,X)-gamma extrapolation technique.

The Technical Committee for Ionizing Radiation (TCRI) of the Asia Pacific Metrology Programme (APMP) recently organized a regional key comparison of activity measurements of the radionuclide ¹³³Ba. This paper reports on absolute measurements made at the National Metrology Institute of South Africa (NMISA) by the coincidence extrapolation technique, with liquid scintillation counting (LSC) comprising the 4π channel. A detection efficiency analysis was undertaken to predict the maximum efficiency likely to be achieved and to confirm that the method does indeed provide the source disintegration rate for ¹³³Ba. Various experimental and data analysis difficulties to be aware of are discussed in the paper.     

Absolute activity of Ba by liquid scintillation coincidence counting using the 4π(e,X)-γ extrapolation technique

The Technical Committee for Ionizing Radiation (TCRI) of the Asia Pacific Metrology Programme (APMP) recently organized a regional key comparison of activity measurements of the radionuclide ¹³³Ba. This paper reports on absolute measurements made at the National Metrology Institute of South Africa (NMISA) by the coincidence extrapolation technique, with liquid scintillation counting (LSC) comprising the 4π channel. A detection efficiency analysis was undertaken to predict the maximum efficiency likely to be achieved and to confirm that the method does indeed provide the source disintegration rate for ¹³³Ba. Various experimental and data analysis difficulties to be aware of are discussed in the paper.     

Microdialysis assessment of adipose tissue metabolism in post-absorptive obese NIDDM subjects

Abstract. Lactate and glycerol turnover is enhanced in obesity and NIDDM. To evaluate the influence of NIDDM on subcutaneous adipose tissue metabolism microdialysis combined with ¹³³Xe clearance and measurements in arterialized plasma were carried out using samples of subcutaneous abdominal fat from nine obese NIDDM subjects (glucose, 7.9 ± 0.7 mmol L^-1) (mean±SEM) and nine obese non-diabetic subjects (glucose, 4.9 ±0.1) matched for age, BMI and body fat. After an overnight fast arterialized plasma levels were 1145 ±110 vs. 876 ±59 μmol L^-1 ( P <0.05) for lactate and 75±10 vs. 66 ±8 μmol L^-1 for glycerol in the diabetic and control group, respectively. The corresponding abdominal subcutaneous interstitial lactate and glycerol concentrations were 1278 ± 63 vs 1107 ±64 μmolL^-1 and 314 ±28 vs. 311 ± 17μmol L^-1, respectively. However, adipose tissue blood flow in the same region was lower in NIDDM subjects (1.5±0.2 vs 2.4±0.3 mL 100g^-1 min^-1) ( P <0.05). Consequently, apparent subcutaneous lactate and glycerol release, estimated according to Fick, were not statistically different in the two groups (1.8 ±0.4 vs 2.4 ±0.8 and 2.1 ±0.4 vs 3.1 ±0.5 μmol kg^-1 min^-1 in NIDDM and control subjects, respectively). Thus, in the post-absorptive state apparent lactate and glycerol release by the abdominal subcutaneous tissue in obese NIDDM subjects was similar to that in a matched group of obese non-diabetic controls. The data suggest that no primary defect is evident in adipose tissue metabolism in well controlled NIDDM subjects.     

Transcranial Doppler Blood Flow Velocity versus 133Xe Clearance Cerebral Blood Flow During Mild Hypothermic Cardiopulmonary Bypass

Objective. Transcranial doppler (TCD) is used during cardiopulmonary bypass (CPB) to assess cerebral emboli and to estimate cerebral perfusion. We sought to compare TCD middle cerebral artery blood flow velocity (V_mca) to ¹³³Xe clearance cerebral blood flow (CBF) measurements during mild hypothermic CPB thus determining its utility in cerebral perfusion assessment. Methods. Thirty-four patients undergoing mild hypothermic CPB (35 °C) were studied and had comparisons of V_mca and ¹³³Xe CBF at three time intervals, 10, 30 and 60 min after the institution of CPB. Linear regression analysis was performed on data from each of the 3 intervals as well as for pooled data from all 3 periods. Results. The correlation coefficients for the 3 time periods were, r = 0.32 (p = 0.12), r = 0.32 (p = 0.11), r = 0.48 (p = 0.02), respectively. The pooled data correlation had a coefficient of 0.34 (p = 0.003). Conclusion. These findings suggest that TCD V_mca is a relatively poor correlate of CBF during mild hypothermic CPB.