Acoustic characterization of a new trisacryl contrast agent. Part II: Flow phantom study and in vivo quantification

The biocompatible trisacryl particles (TMP) are made of a cross-linked acrylic copolymer. Their inherent acoustic properties, studied for a contrast agent application, have been previously demonstrated in a in vitro Couette device. To measure their acoustic behaviour under circulating blood conditions, the TMP backscatter enhancement was further evaluated on a home-made flow phantom at different TMP doses (0.12-15.6 mg/ml) suspended in aqueous and blood media, and in nude mice (aorta and B16 grafted melanoma). Integrated backscatter (IB) was measured by spectral analysis of the Doppler signals recorded from an ultrasound system (Aplio^®) combined with a 12-MHz probe. Doppler phantom experiments revealed a maximal IB of 17 ± 0.88 dB and 7.5 ± 0.7 dB in aqueous and blood media, respectively. IB measured on mice aorta, in pulsed Doppler mode, confirmed a constant maximal value of 7.29 ± 1.72 dB over the first minutes after injection of a 7.8 mg/ml TMP suspension. Following the injection, a 60% enhancement of intratumoral vascularization detection was observed in power Doppler mode. A preliminary histological study revealed inert presence of some TMP in lungs 8 and 16 days after injection.Doppler phantom experiments on whole blood allowed to anticipate the in vivo acoustic behaviour. Both protocols demonstrated TMP effectiveness in significantly increasing Doppler signal intensity and intratumoral vascularization detection. However, it was also shown that blood conditions seemed to shadow the TMP contrast effect, as compared to in vitro observations. These results encourage further investigations on the specific TMP targeting and on their bio-distribution in the different tissues.     

黑色素瘤循环肿瘤细胞检测的金属卤化物钙钛矿外泌体复合探针检测新策略

液体活检技术的兴起为黑色素瘤的快速、准确诊断提供了新的机遇.然而,普通循环肿瘤细胞活检基于上皮黏附蛋白进行阳性富集,但信号标记的有机荧光探针存在量子效率低的问题,导致检测黑色素瘤循环肿瘤细胞时准确率和灵敏度较低.本文以高量子效率的金属卤化物钙钛矿量子点作为信号标记物,以黑色素瘤来源的外泌体作为生物识别分子,构建了一种用于黑色素瘤液体活检的循环肿瘤细胞检测新策略.与商品化的上皮细胞黏附蛋白富集策略相比,本研究报道的复合探针检测新策略,其检测灵敏度提高了一个数量级,并且具有良好的亲水性和低毒性.实验结果证明了外泌体引导的金属卤化物钙钛矿量子点指示的黑色素瘤循环肿瘤细胞检测新策略具有理想的应用前景.     

基于质谱技术研究黑色素瘤血清特异性O-糖链

对接种和未接种B16黑色素瘤细胞的C57小鼠进行血清O-糖链比较糖组学研究,寻找黑色素瘤血清特异性O-糖链.小鼠血清10μL,β-消除反应释放O-糖链.反应混合物经石墨化炭黑固相萃取小柱(GCC SPE)分离纯化后,用于MALDI-Qit-TOF-MS分析.通过Launchpad软件采集并输出质谱数据,MATLAB进行数据解析,找到了10个稳定出现的差异糖链质谱峰.利用串联质谱分析了其中5个主要差异糖链的结构.     

New coumarin from the roots of Prangos pabularia

The new coumarin 1, yuganin A (7-methoxy-8-((1S,2S)-1,2,3-trihydroxy-3-methylbutyl)-2H-chromen-2-one) along with nine known coumarins, heraclenol 3′-O-β-D-glucopyranoside (2), oxypeucedanin hydrate 3′-O-β-D-glucopyranoside (3), heraclenol (4), oxypeucedanin hydrate (5), osthole (6), oxypeucedanin (7), heraclenin (8), isoimperatorin (9), imperatorin (10) and the disaccharide sucrose (11), have been isolated from the roots of Prangos pabularia, and the structures of these isolated compounds were elucidated by spectroscopic means, especially, UV, HR-ESIMS, and 1D and 2D NMR spectroscopy. Furthermore, the anti-melanogenic effect of yuganin A and its inhibitory effect on B16 cells were evaluated. Yuganin A may be useful in the treatment of hyperpigmentation and as a skin-whitening agent in the cosmetics industry.     

高效液相色谱法测定黑色素瘤小鼠尿液中达卡巴嗪

达卡巴嗪是治疗恶性黑色素瘤的一线化疗药物。它在体内主要经肝脏代谢,同时部分药物仍以原药形式经尿液排出。这就意味着可以通过监测尿液中达卡巴嗪的含量评估其在人体内的利用率和转化率,进而对其治疗效果进行评价。针对达卡巴嗪,人们发展了多种分析方法,但多基于高效液相色谱-质谱平台。然而达卡巴嗪为强极性弱碱性化合物,采用常规反相色谱法分析时会出现出峰时间过早、峰形拖尾的现象,导致定量不准确。基于此,该文建立了一种测定尿液中达卡巴嗪含量的高效液相色谱方法以克服上述问题。小鼠尿液经丙酮沉淀法去除蛋白后,采用Shimadzu-GL ODS柱(150 mm×4.6 mm, 5μm)分离,色谱条件如下:流动相为甲醇/乙腈(1∶1, v/v)-0.01 mol/L磷酸二氢钠溶液(pH=6.5)(20∶80, v/v),流速1 mL/min,检测波长280 nm,柱温35℃,洗脱时间15 min。在该色谱条件下,达卡巴嗪保留时间为5.3 min且峰形良好。其在0.25～1 000μg/mL范围内线性关系良好(r²=0.999)。基于信噪比(S/N)=3和S/N=10,计算出检出限和定量限分...     

Raman spectroscopy detects melanoma and the tissue surrounding melanoma using tissue-engineered melanoma models

Invasion of melanoma cells from the primary tumor involves interaction with adjacent tissues and extracellular matrix. The extent of this interaction is not fully understood. In this study Raman spectroscopy was applied to cryo-sections of established 3D models of melanoma in human skin. Principal component analysis was used to investigate differences between the tumor and normal tissue and between the peri-tumor area and the normal skin. Two human melanoma cells lines A375SM and C8161 were investigated and compared in 3D melanoma models. Changes were found in protein conformations and tryptophan configurations across the entire melanoma samples, in tyrosine orientation and in more fluid lipid packing only in tumor dense areas, and in increased glycogen content in the peri-tumor areas of melanoma. Raman spectroscopy revealed changes around the perimeter of a melanoma tumor as well as detecting differences between the tumor and the normal tissue.     

Synthesis of Cytotoxic Palmerolides

The chemical synthesis of the palmerolides is the subject of this review. The palmerolides are a family of Antarctic marine natural products, many of which display potent and selective cytotoxicity against melanoma cells. The confluence of promising bioactivities, limited natural supplies, and complex structures makes the palmerolides exciting targets for chemical synthesis. To date, several approaches have been reported, and a consensus strategy based on convergent fragment assembly has emerged. Collective wisdom from myriad approaches reviewed here may enable hybrid strategies capable of delivering larger amounts of synthetic palmerolides to support continued biological studies. Considering the relative lack of options for melanoma chemotherapy and the intriguing activity profile of the palmerolides, efforts aimed at developing an efficient, gram‐scale synthesis of palmerolide A and congeneric structures should be given a high priority.