T1ρ MRI of human musculoskeletal system

Magnetic resonance imaging (MRI) offers the direct visualization of the human musculoskeletal (MSK) system, especially all diarthrodial tissues including cartilage, bone, menisci, ligaments, tendon, hip, synovium, etc. Conventional MRI techniques based on T₁‐ and T₂‐weighted, proton density (PD) contrast are inconclusive in quantifying early biochemically degenerative changes in MSK system in general and articular cartilage in particular. In recent years, quantitative MR parameter mapping techniques have been used to quantify the biochemical changes in articular cartilage, with a special emphasis on evaluating joint injury, cartilage degeneration, and soft tissue repair. In this article we focus on cartilage biochemical composition, basic principles of T_1ρ MRI, implementation of T_1ρ pulse sequences, biochemical validation, and summarize the potential applications of the T_1ρ MRI technique in MSK diseases including osteoarthritis (OA), anterior cruciate ligament (ACL) injury, and knee joint repair. Finally, we also review the potential advantages, challenges, and future prospects of T_1ρ MRI for widespread clinical translation. J. Magn. Reson. Imaging 2015;41:586–600. © 2014 Wiley Periodicals, Inc.     

Measurement of glucose and fructose in clinical samples using gas chromatography/mass spectrometry

Objective:The impact of increased fructose consumption on carbohydrate metabolism is a topic of current interest, but determination of serum level has been hindered due to low concentration and interference from serum glucose. We are reporting a method for the quantification of glucose and fructose in clinical samples using gas chromatography/mass spectrometry (GC/MS). The accuracy and precision of GC/MS and an enzymatic assay were compared.Design and methods:Mass spectrometry fragmentation patterns of methyloxime peracetate derivatized aldose and ketose were determined. Unique fragments for glucose and fructose were used for quantitative analysis using isotope labeled recovery standards.Results:Methyloxime peracetate derivatives of glucose and fructose showed characteristic loss of acetate (M-60) or ketene (M-42) under chemical ionization (CI). Under electron impact (EI) ionization, a unique C1–C2 fragment of glucose was formed, while a C1–C3 fragment was formed from keto-hexoses. These unique fragments were used in the quantitative assay of glucose and fructose in clinical samples. In clinical samples, the GC/MS assay has a lower limit of detection than that of the enzymatic assay. In plasma samples from patients evaluated for diabetes the average serum glucose and fructose were 6.19 ± 2.72 mM and 46 ±  25.22 μM. Fructose concentrations in many of these samples were below the limit of detection of the enzymatic method.Conclusion:Derivatization of aldose and ketose monosaccharides to their respective O-methyloxime acetates for GC/MS analysis is a facile method for determination of serum/plasma glucose and fructose samples.     

HPLC-MS/MS法研究PVP包衣去甲斑蝥素壳聚糖纳米粒在大鼠体内的药代动力学

目的:建立HPLC-MS/MS方法测定大鼠血浆中去甲斑蝥素(NCTD)浓度,并考察PVP包衣去甲斑蝥素-壳聚糖纳米粒制剂(PVP coated NCTD-chitosan nanoparticles,PVP-NCTD-NP)在大鼠体内药代动力学及相对生物利用度。方法:使用电喷雾电离负离子源(ESI-),多重反应离子(MRM)模式检测药物;采用高氯酸作为蛋白沉淀剂,测定大鼠尾静脉注射PVP-NCTD-NP和原药NCTD溶液后的血药浓度;利用3P97软件计算药代动力学参数。结果:NCTD在0.102 5～10.25μg·mL-1范围内线性关系良好(r=0.999 2),最低检测限为50 ng·mL-1;经3P97软件拟合,NCTD的药代动力学过程符合二室模型,与原药相比,PVP-NCTD-NP相对生物利用度为325.5%。结论:本法灵敏、准确、选择性高,适用于NCTD药代动力学的研究;PVP-N-CTD-NP可促进药物的吸收,显著提高NCTD的生物利用度。     

体外染烟对V79细胞增殖和凋亡的影响

目的研究体外香烟烟雾对V79细胞增殖和凋亡的影响。方法将V79细胞分为对照组、5%浓度组和20%浓度组进行染烟实验。染烟后检测细胞内ROS水平、细胞增殖活性、细胞周期及凋亡情况。结果5%浓度和20%浓度染烟组与对照组相比,V79细胞ROS水平均明显升高,且20%浓度组与5%浓度组相比ROS也明显升高,差异均有统计学意义（均P〈0.05）。5%浓度和20%浓度染烟组与对照组相比,细胞增殖率、克隆率明显降低;G1期细胞百分比明显升高,G2期和S期细胞明显减少,差异均有统计学意义（均P〈0.05）。20%浓度染烟组分别与对照组和5%浓度染烟组相比,细胞凋亡率均明显升高,差异有统计学意义（P〈0.05）。结论香烟烟雾可能刺激了V79细胞内ROS的增多,影响细胞增殖和凋亡率。     

细胞核靶向富勒醇硬脂质纳米粒的制备与表征

目的制备细胞核靶向富勒醇硬脂质纳米粒,并对其性质进行表征。方法胺催化合成法合成富勒醇,并且通过使用生物材料,将富勒醇包裹起来,在其表面连接与核受体具有高度亲和力的雌激素类似物,制备成新的纳米材料。对制备的富勒醇及其硬脂质纳米粒进行了分析和表征。结果结果表明,合成的富勒醇分子式为C60(OH)24,其硬脂质纳米粒能够通过核膜,到达细胞核。结论通过该实验方法可制备在细胞核靶向的富勒醇硬脂质纳米粒,为进一步研究细胞核靶向的电离辐射防护药物提供依据。     

Evaluation of magnetic resonance imaging and radionuclide bone scan in early spondyloarthropathy

IntroductionSpondyloarthropathy (SpA) comprises a small percentage of low backache (LBA) and presents with inflammatory pain. Sacroiliitis in SpAs forms the basis of diagnosis, and may take 7–8 years to become visible in plain radiographs. In order to achieve significant modification of the course of the disease it is imperative to make an early diagnosis, identify risk factors for aggressive disease and initiate the therapy right at outset. Magnetic resonance imaging (MRI) is a promising modality to pick up inflammation and structural damage early in the course of the disease.ObjectiveTo assess the role of MRI and radionuclide bone scan in patients with early SpA of less than 2 years.MethodsPatients with inflammatory LBA, defined according to the Calin criteria and satisfying the European Spondyloarthropathy Study Group (ESSG) criteria for SpA of less than 2 years duration, were included. Controls had mechanical LBA. A detailed clinical assessment and assessment of disease activity and functional impairment was done with validated measures. Radiological assessment included conventional radiograph of the pelvis, radionuclide scan and MRI of sacroiliac joints (SI joints). The sensitivity, specificity and predictive value of each modality in contributing to the diagnosis of SpA were assessed.ResultsAssessment of 132 SI joints in 33 patients (Age 31 ± 6.14 years, M:F 24:9) and 33 controls (Age 31.8 ± 7.21 years, M:F 27:5) was done. The mean disease duration of cases was 10.7 (± 6.97) months. Conventional radiograph failed to pick up sacroiliitis in any of the cases. Positive bone scan was present in 27 patients (21 bilateral sacroiliitis, 6 unilateral sacroiliitis). Bone scan had a sensitivity of 81.8% and a specificity of 88%. MRI abnormality was present in 29 patients (50 joints, bilateral in 21 and unilateral in 8) and in none of the controls. This accounted for a sensitivity of 87.9% and a specificity of 100%. The MRI changes included bone marrow oedema (89%), synovial enhancement (55%), subchondral oedema (41%), erosions (51%) and sclerosis (28%). Both inflammatory and structural changes in MRI showed positive correlation with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (P = 0.034, 0.02) and erythrocyte sedimentation rate (ESR) (P = 0.02, 0.001).ConclusionsIn patients with early SpA of less than 2 years duration, conventional radiographs did not pick up sacroiliitis; however, both the radionuclide scan and MRI were useful.     

一次性使用滴定管式输液器辐照灭菌后组织相容性和致畸毒性研究

目的观察一次性使用滴定管式输液器辐照灭菌后组织相容性和致畸毒性,为辐射灭菌后的医疗产品安全应用提供依据。方法依据ISO11137标准相关规定,采用细胞毒性试验和动物试验对辐照灭菌后的一次性使用滴定管式输液器进行了组织相容性和致畸毒性评价。结果试验的灭菌剂量为9.4 kGy,辐照灭菌后的一次性使用滴定管式输液器无细胞毒性、不会致敏和引起皮内刺激,无遗传毒性(不会引起染色体畸变),无诱导骨髓多染红细胞微核发生率增高作用。结论经设定剂量辐照灭菌后的一次性使用滴定管式输液器组织相容性良好、无致畸毒性,辐射灭菌作为医疗器械灭菌方法具有较好的安全性。     

B细胞易位基因2过表达增加人乳腺癌细胞T-47D的放射敏感性的研究

目的研究B细胞易位基因2（BTG2）对人乳腺癌细胞T-47D放射敏感性的影响。方法应用脂质体转染的方法提高BTG2基因在人乳腺癌细胞T-47D的表达水平,利用克隆形成实验研究转染后细胞的放射敏感性改变,采用流式细胞术对细胞周期变化进行分析,应用Western blot方法研究相关蛋白的变化。结果克隆形成细胞生存实验结果表明,BTG2稳定高表达的T-47D/BTG2细胞在不同剂量X射线照射后,其存活分数明显低于X射线照射后的未转染的T-47D/Parental（母）细胞以及＂空质粒＂转染的对照T-47D/Neo细胞的存活分数。细胞平均致死剂量（D0）值在T-47D/Parental细胞、T-47D/Neo细胞和T-47D/BTG2细胞分别为1.84,1.86和1.57。流式细胞实验结果显示,与T-47D/母细胞和T-47D/Neo细胞相比,T-47D/BTG2细胞在受照射后出现明显的细胞凋亡sub-G1峰。另外,BTG2高表达上调了Bad和Bax促凋亡蛋白的表达水平和下调了协作性的致癌基因Cyclin D1的表达水平。结论增加BTG2基因的表达水平可以明显提高凋亡相关蛋白水平,增加放射治疗所诱导的细胞凋亡,从而提高人类乳腺癌细胞T-47D对电离辐射放射治疗的敏感性。BTG2可能是调节人类乳腺癌细胞放射治疗的有效靶点之一。