Glu-GNPs对人肺腺癌细胞株A549放射增敏的初步探讨

目的探讨偶联葡萄糖的纳米金颗粒(Glu-GNPs)对人A549细胞的放射增敏作用及其机制。方法噻唑蓝(MTT)法检测低浓度(≤20 nmol/L)Glu-GNPs联合放射对A549细胞存活的影响,克隆形成检测Glu-GNPs对A549细胞的放射增敏作用,流式细胞仪(FCM)检测细胞周期及其凋亡。结果低浓度Glu-GNPs对A549细胞生长无明显抑制,联合X射线后具有抑制作用,在15 nmol/L范围内,随浓度增大,抑制作用增强;15 nmol/LGlu-GNPs对A549细胞有放射增敏作用,由Dq、Do计算放射增敏比(SER)分别为1.93、1.10;Glu-GNPs、单纯放射均可诱导细胞凋亡,凋亡率分别为(7.64±1.43)%、(13.46±1.99)%,联合放射组凋亡率为(21.43±1.04)%,显著高于前两组(P<0.01);Glu-GNPs作用后,细胞周期发生变化,表现为S期减少,G2/M期增加(P<0.05)。结论 Glu-GNPs对人肺腺癌细胞株A549具有放射增敏作用,其机制可能为抑制细胞亚致死损伤修复,阻滞细胞于G2/M期,并诱导细胞凋亡。     

2种不同试剂检测血清免疫球蛋白结果的可比性及偏倚评估

目的进行2种不同免疫球蛋白诊断试剂对血清免疫球蛋白测定结果的可比性及偏倚评估研究,为血清免疫球蛋白测定的标准化和临床实验室认可提供实验数据。方法参考美国临床和实验室标准协会(CLSI)的EP9A2文件,分别用执诚试剂和优利特试剂在HITACHI7600-010全自动生化分析仪上测定免疫球蛋白IgG、IgA和IgM,以执诚试剂为对照组,优利特试剂为实验组。用线性回归统计法分析对照组(Y)和实验组(X)测定结果决定水平处的方法间误差,以美国临床实验室修正法规(CLIA′88)规定的室间质量评价允许误差范围的1/2为标准,判断不同试剂的临床可接受性。结果两种试剂对患者血清免疫球蛋白测定结果显示,方法内重复性良好,无离群点,除IgA在决定水平处的系统误差不能被接受外,其余项目测定结果的偏差临床可以接受。结论当同一实验室同一检验项目存在2个或以上的试剂时,应进行方法比对和偏差评估,判断其临床可接受性,以保证检验结果的可比性。     

Evaluation of bisphenol A glucuronidation according to UGT1A1*28 polymorphism by a new LC-MS/MS assay

The endocrine disruptor bisphenol A (BPA) is a frequently used chemical in the manufacture of consumer products. In humans, BPA is extensively metabolized to BPA glucuronide (BPAG) by different UDP-glucuronosyltransferase (UGT) isoforms. The study has been performed with the intention to improve the accuracy of published physiologically based pharmacokinetic models and to improve regulatory risk assessments of BPA. In order to gain insight into intestine, kidney, liver, and lung glucuronidation of BPA, human microsomes of all tested organs were used. BPAG formation followed Michaelis-Menten kinetics in the intestine and kidney, but followed substrate inhibition kinetics in the liver. Human lung microsomes did not show glucuronidation activity towards BPA. While the liver intrinsic clearance was very high (857 mL min(-1)kg body weight(-1)), the tissue intrinsic clearances for the kidney and intestine were less than 1% of liver intrinsic clearance. Since BPA is a UGT1A1 substrate, we postulated that the common UGT1A1*28 polymorphism influences BPA glucuronidation, and consequently, BPA detoxification. Hepatic tissue intrinsic clearances for UGT1A1*1/*1, UGT1A1*1/*28, and UGT1A1*28/*28 microsomes were 1113, 1075, and 284 mL min(-1)kg body weight(-1), respectively. Prior to microsomal experiments, the bioproduction of BPAG and stable isotope-labeled BPAG (BPAG(d16)) was performed for the purpose of the reliable and accurate quantification of BPAG. In addition, a sensitive LC-MS/MS analytical method for the simultaneous determination of BPA and BPAG based on two stable isotope-labeled internal standards was developed and validated. In conclusion, our in vitro results show that the liver is the main site of BPA glucuronidation (K(m) 8.9 μM, V(max) 8.5 nmol min(-1) mg(-1)) and BPA metabolism may be significantly influenced by a person's genotype (K(m) 10.0-13.1 μM, V(max) 3.4-16.2 nmol min(-1) mg(-1)). This discovery may be an important fact for the currently on-going worldwide BPA risk assessments and for the improvement of physiologically based pharmacokinetic models.     

Imaging agents for myeloperoxidase

The myeloperoxidase (MPO) inhibitors 1 and 2 were prepared as their isotopologues with carbon‐14, carbon‐13, and nitrogen‐15 or tritium with high specific activity and purity. Starting from potassium [¹⁴C]cyanide or [¹⁴C]formate provided metabolically stable ¹⁴C‐labels on [¹⁴C]‐1 and [¹⁴C]‐2. Catalytic hydrogenation was used for the preparation of [³H]‐2, giving multiple enriched positions as shown by ³H NMR. 1 and 2 are promising in vitro and in vivo imaging radioligands and have the potential to provide key information with regard to MPO expression, function, stoichiometry, and pharmacology.     

Synthesis and biological evaluation of a series of 99mTc‐labeled diphosphonates as novel radiotracers with improved bone imaging

Three radiolabeled diphosphonates, ^99mTc‐labeled 1‐hydroxy‐3‐(2‐propyl‐1H‐imidazol‐1‐yl)propane‐1,1‐diyldiphosphonic acid (PIPrDP), 1‐hydroxy‐4‐(2‐propyl‐1H‐imidazol‐1‐yl)butane‐1,1‐diyldiphosphonic acid (PIBDP), and 1‐hydroxy‐5‐(2‐propyl‐1H‐imidazol‐1‐yl)pentane‐1,1‐diyldiphosphonic acid (PIPeDP), have been designed and synthesized with good chemical yields and high radiochemical purity. Their in vitro and in vivo biological properties were investigated and compared. All radiotracers evaluated in mice showed substantial retention in bone (8.42 ± 0.53, 9.08 ± 0.65, and 10.3 ± 0.61 ID%/g, respectively) at 1 h post‐injection and had rapid clearance in blood (1.9484, 1.3666, and 0.7704 ID%/g/min, respectively). ^99mTc‐PIBDP has the highest uptake ratio of bone‐to‐soft tissue at 1 h post‐injection among the three radiotracers. The results indicate that ^99mTc‐PIBDP is the most promising bone imaging agent. Copyright © 2012 John Wiley & Sons, Ltd.     

微柱凝胶免疫检测卡在临床输血中的应用

目的:应用两种微柱凝胶免疫检测卡在不规则抗体筛查、交叉配血试验和直接抗人球蛋白试验中观察两者间的差异性及与传统试管法作比较。方法:应用Diamed和Biovue两种免疫检测卡对本院住院患者的血标本进行上述对比试验,凝聚胺试剂试管法进行交叉配血试验。结果:显示两种免疫检测卡做不规则抗体筛查、交叉配血试验和直接抗人球蛋白试验的符合率分别为100%、100%、99.7%,符合率完全相同。结论:两种免疫检测卡之间虽然存在着部分差异,但都可以捕捉到十分微弱的抗原抗体反应且符合率相同,比手工操作简便、标准化、易于保存,对临床安全输血有极大的帮助。     

Use of QuantiFERON-TB Gold to investigate tuberculosis contacts in a high school

BACKGROUND AND OBJECTIVE: QuantiFERON-TB Gold (QFT-G) was employed in a contact investigation in a high school to evaluate its performance in adolescents. METHODS: Students of the same school grade as the index case were screened with tuberculin skin test (TST) and CXR examination as an initial contact investigation. QFT-G was performed for students demonstrating a positive TST (erythema larger than 30 mm). RESULTS: Of 349 students whose TST was completed, 95 had positive TST responses, although the distribution of TST responses was similar for both high and low exposure groups. In contrast, only four of the 88 TST-positive students tested with QFT-G were positive by this test, and three of these were from the high exposure group. Chemoprophylaxis was provided to only those four QFT-G-positive students. Follow up of the 91 students who were TST-positive, but QFT-G-negative (or not tested), for more than 3.5 years revealed that none have developed active tuberculosis. CONCLUSIONS: QFT-G appears more specific than TST as contacts with positive TST and negative QFT-G responses were not offered prophylaxis and none developed tuberculosis during 3.5 years of follow up. The replacement of TST with QFT-G, or perhaps combined use of TST and QFT-G, may be more useful in diagnosing true infection and thus reducing the number of subjects indicated for chemoprophylaxis.     

Evaluation of leukocyte esterase and nitrite strip tests to detect spontaneous bacterial peritonitis in cirrhotic patients

AIM： To investigate the diagnostic efficacy of leukocyte esterase and nitrite reagent strips for bedside diagnosis of spontaneous bacterial peritonitis （SBP）. METHODS： A total of 63 consecutive patients with cirrhotic ascites （38 male, 25 female） tested between April 2005 and July 2006 were included in the study. Bedside reagent strip testing was performed on ascitic fluid and the results compared to manual cell counting and ascitic fluid culture. SBP was defined as having a polymorphonuclear ascites count of ≥ 250/mm^3. RESULTS： Fifteen samples showed SBP. The sensitivity, specificity, positive and negative predictive values of the leukocyte esterase reagent strips were; 93%, 100%, 100%, and 98%, respectively. The sensitivity, specificity, positive and negative predictive value of the nitrite reagent strips were 13%, 93%, 40%, and 77%, respectively. The combination of leukocyte esterase and nitrite reagents strips did not yield statistically significant effects on diagnostic accuracy. CONCLUSION： Leukocyte esterase reagent strips may provide a rapid, bedside diagnostic test for SBP.     

Cost-effectiveness of interferon-gamma release assay screening for latent tuberculosis infection treatment in Germany

OBJECTIVES: To assess the cost-effectiveness of the new QuantiFERON-TB Gold In-Tube (QFT-G) [Cellestis; Carnegie, VIC, Australia] assay for screening and treating of persons who have had close contact with tuberculosis (TB) patients and are suspected of having latent tuberculosis infection (LTBI) [hereafter called close-contacts] in Germany. METHODS: The health and economic outcomes of isoniazid treatment of 20-year-old close-contacts were compared in a Markov model over a period of 20 years, using two different cutoff values for the tuberculin skin test (TST), the QFT-G assay alone, or the QFT-G assay as a confirmatory test for the TST results. RESULTS: QFT-G assay-based treatment led to cost savings of $542.9 and 3.8 life-days gained per LTBI case. TST-based treatment at a 10-mm induration size cutoff gained $177.4 and 2.0 life-days gained per test-positive contact. When the cutoff induration size for the TST was reduced to 5 mm, the incremental cost-effectiveness ratio fell below the willingness-to-pay threshold ($30,170 per life-years gained) but resulted in unnecessary treatment of 77% of contacts owing to false-positive TST results. Combination with the 5-mm induration size TST cutoff value compared to the results of the QFT-G assay alone reduced the total costs per 1,000 contacts by 1.8% to $222,869. The number treated to prevent 1 TB case was 22 for the two QFT-G assay-based procedures, 40 for the TST at a cutoff induration size of 10 mm, and 96 for the TST at a cutoff induration size of 5 mm. When the sensitivity rates of the TST and the QFT-G assay were compounded, the QFT-G assay strategy alone was slightly less costly (0.6%) than the two-step approach. CONCLUSIONS: Using the QFT-G assay, but especially combining the QFT-G assay following the TST screening of close-contacts at a cutoff induration size of 5 mm before LTBI treatment is highly cost-effective in reducing the disease burden of TB.     

MRI detection of macrophages labeled using micrometer-sized iron oxide particles

PURPOSE: To evaluate cellular labeling of immune cells using micron-sized iron oxide particles (MPIOs) and evaluate the MR relaxivity and MRI detection of the labeled cells. MATERIALS AND METHODS: Immune cells isolated from mice and rats were labeled with three different sizes of MPIO particles (0.35, 0.90, or 1.63 microm). These labeled cells were characterized using transmission electron microscopy (TEM), fluorescence microscopy, flow cytometry, MR relaxometry, and MRI. RESULTS: Macrophage uptake of MPIOs was found to be highest for the 1.63-microm size particles. MR relaxivity measurements indicated greater spin-spin relaxation for MPIO-labeled cells relative to cells labeled with nanometer-sized ultra-small superparamagnetic iron oxide (USPIO) particles with similar iron content. TEM and fluorescence microscopy indicated cellular uptake of multiple MPIO particles per cell. Macrophages labeled with 1.63-microm MPIOs had an average cellular iron uptake of 39.1 pg/cell, corresponding to approximately 35 particles per cell. CONCLUSION: Cells labeled with one or more MPIO particles could be readily detected ex vivo at 11.7 Tesla and after infusion of the MPIO-labeled macrophages into the kidney of a rat, hypointense regions of the outer cortex are observed, in vivo, by MRI at 4.7 Tesla.