Hypocrellin B in hepatocellular carcinoma cells: Subcellular localization and sonodynamic damage

Abstract

Purpose: To study subcellular localization of hypocrellin B in hepatocellular carcinoma cells, and hypocrellin B-mediated sonodynamic action-induced cell damage.

Materials and methods: After incubation with 2.5 μM of hypocrellin B, human hepatocellular carcinoma HepG2 cells were exposed to ultrasound waves for 8 sec at an intensity of 0.46 W/cm². Clonogenic survival of HepG2 cells was measured using a colony forming assay and light microscope. Ultrastructural morphology was observed using transmission electron microscope (TEM) and mitochondrial membrane potential (MMP) was assessed using confocal laser scanning microcope (CLSM) after rhodamine 123 staining. Additionally, subcellular localization of hypocrellin B in HepG2 cells with organelle probe staining was also observed using CLSM.

Results: The colony forming units of HepG2 cells decreased substantially after sonodynamic treatment. The results of TEM showed microvilli disappearance, apoptotic body formation, swollen mitochondria with loss of cristae and mitochondrial myelin-like features (or membrane whorls). Collapse of MMP was found in the treated cells. Hypocrellin B was distributed in mitochondria and lysosomes as well as in endoplasmic reticulum and Golgi apparatus.

Conclusions: The findings demonstrated that sonodynamic action of hypocrellin B induced mitochondrial damage, survival inhibition, and apoptosis of HepG2 cells. Additionally, other subcellular organelles such as endoplasmic reticulum, Golgi apparatus and lysosomes were also the targets of hypocrellin B-mediated sonodynamic action as well as mitochondria.     

Diagnostic performance of computed tomography for parathyroid adenoma localization; a systematic review and meta-analysis

Abstract purposeTo perform a systematic review and meta-analysis of the sensitivity and positive predictive value (PPV) of CT for preoperative parathyroid localization in patients with primary hyperparathyroidism (pHPT), and subsequently compare the different protocols and their performance in different patient groups.Materials and methodsWe performed a search of the Embase, Pubmed and Cochrane Library databases to identify studies published between January 1, 2000 and March 31, 2016 investigating the diagnostic value of CT for parathyroid localization in patients with biochemical diagnosis of pHPT. Performance of CT was expressed in sensitivity and PPV with pooled proportion using a random-effects model. Factors that could have affected the diagnostic performance were investigated by subgroup analysis.ResultsThirty-four studies evaluating a total of 2563 patients with non-familial pHPT who underwent CT localization and surgical resection were included. Overall pooled sensitivity of CT for localization of the pathological parathyroid(s) to the correct quadrant was 73% (95% CI: 69–78%), which increased to 81% (95% CI: 75–87%) for lateralization to the correct side. Subgroup analysis based on the number of contrast phases showed that adding a second contrast phase raises sensitivity from 71% (95% CI: 61–80%) to 76% (95% CI: 71–87%), and that adding a third phase resulted in a more modest additional increase in performance with a sensitivity of 80% (95% CI: 74–86%).ConclusionCT performs well in localizing pathological glands in patients with pHPT. A protocol with two contrast phases seems to offer a good balance of acceptable performance with limitation of radiation exposure.     

Human Antibody Fragments Specific for the Epidermal Growth Factor Receptor Selected from Large Non-immunised Phage Display Libraries

Antibodies to EGFR have been shown to display anti-tumour effects mediated in part by inhibition of cellular proliferation and angiogenesis, and by enhancement of apoptosis. Humanised antibodies are preferred for clinical use to reduce complications with HAMA and HAHA responses frequently seen with murine and chimaeric antibodies. We have used depletion and subtractive selection strategies on cells expressing the EGFR to sample two large antibody fragment phage display libraries for the presence of human antibodies which are specific for the EGFR. Four Fab fragments and six scFv fragments were identified, with affinities of up to 2.2 nM as determined by BIAcore analysis using global fitting of the binding curves to obtain the individual rate constants (k_a and k_d). This overall approach offers a generic screening method for the identification of growth factor specific antibodies and antibody fragments from large expression libraries and has potential for the rapid development of new therapeutic and diagnostic reagents.     

基于超声定位的火器贯穿伤标准化动物损伤模型的构建

目的:基于超声定位技术,构建一种模拟真实战场环境下的股动脉火器贯穿伤标准化动物损伤模型。方法:选择体质量指数与人体相当的10只长白猪作为实验对象,采用定制弹道步枪和欧盟制式子弹作为致伤武器,使用自制超声引导定位架作为辅助血管定位装置。采用超声探头定位实验动物左侧股动脉血管位置,利用超声引导定位架和致伤架将实验动物的股动脉血管中心调整至子弹弹道轨迹线上射击致伤。计算自由出血20 s实验动物体外失血量,测量实验动物体表弹道入口、出口处直径和体内弹道深度,并通过解剖观察股动脉受损情况。采用SPSS 26.0软件进行统计学分析。结果:采用自制的超声引导定位架可以构建相对稳定的股动脉火器贯穿伤标准化动物损伤模型,成功率约90%(9/10);实验动物体表弹道入口平均直径为(7.20±1.03)mm,出口平均直径为(93.30±33.06)mm,两者相比具有明显统计学差异(t=-8.16,P=0.000);实验动物体内弹道平均深度为(191.80±25.50)mm;致伤20 s后死亡实验动物和存活实验动物的平均失血量分别为(478.00±267.48)和(111.50±45.32)g,两者相比没有统计学差异(t= -2.75,P=0.070)。结论:采用自制的超声引导定位架构建的股动脉火器贯穿伤标准化动物损伤模型成功率高、重复性好,且实验动物伤情稳定,可以为新型止血材料和止血装置的研制提供可靠的模型依据。     

肿瘤抑制因子PTEN亚细胞定位与缺血-缺氧性脑损伤

第10号染色体缺失的磷酸酶和张力蛋白同源等位基因(PTEN)具有脂质和蛋白双重磷酸酶活性。脑组织缺血-缺氧后PTEN发生活化并向线粒体或胞核内转移,而这种在神经元内的不同亚细胞定位可能最终决定细胞命运。因此,阐明PTEN在脑缺血-缺氧后的亚细胞定位机制,将为各种急慢性神经退行性变疾病的靶向治疗和药物研发提供新思路。     

Cellular localization of iron(II) polypyridyl complexes determines their anticancer action mechanisms

Elucidation of relationship among cellular uptake, localization and biological activities of metal complexes could make great breakthrough in the understanding of their action mechanisms and provide useful information for rational design of metal-based anticancer drugs. Iron(II) complexes have emerged as potential anticancer drug candidates with application potential in cancer imaging and therapy. Herein, a series of iron(II) polypyridyl complexes with different lipophilicity were rationally designed, synthesized and identified as potent anticancer agents. The relationship between the cellular localization and molecular action mechanisms of the complexes was also elucidated. The results showed that, the increase in planarity of the Fe(II) polypyridyl complexes enhanced their lipophilicity and cellular uptake, leading to improved anticancer efficacy. The hydrophilic Fe(II) complex entered cancer cells through transferring receptor (TfR)-mediated endocytosis, and translocated to cell nucleus, where they induced S phase cell cycle arrest through triggering DNA damage-mediated p53 pathway. Interestingly, the hydrophobic Fe(II) complexes displayed higher anticancer efficacy than the hydrophilic ones, but shared the same uptake pathway (TfR-mediated endocytosis) in cancer cells. They accumulated and localized in cell cytoplasm, and induced G0/G1 cells cycle arrest through regulation of AKT pathway and activation of downstream effector proteins. These results support that the cellular localization of Fe(II) complexes regulated by their lipophilicity could affect the anticancer efficacy and action mechanisms. Taken together, this study may enhance our understanding on the rational design of the next-generation anticancer metal complexes.     

基于颈部软组织张力探讨悬吊循经弹拨结合麦肯基疗法对颈型颈椎病的疗效及机制

目的比较悬吊循经弹拨结合麦肯基疗法与两者分别单一治疗颈型颈椎病的临床疗效差异并探讨其疗效机制。方法将88例符合标准的患者按照随机数字表法分为综合组(29例)、对照1组(30例)、对照2组(29例)。对照1组采用悬吊循经弹拨法,对照2组采用麦肯基疗法,综合组将对照组的治疗方法相结合,5 d为1疗程,共观察2个疗程。应用颈椎病临床评价量表(clinical assessment scale for cervical spondylosis,CASCS)、利用表面肌电图比较2个疗程治疗前后颈椎功能情况以及胸锁乳突肌、斜方肌上部纤维平均功率频率(mean power frequency,MPF)和中位频率(median frequency,MF)数值变化(对应肌肉的疲劳度改变)。结果治疗结束后,综合组总有效率96.55%,优于对照1组总有效率80.00%和对照2组75.86%(P<0.05或P<0.01),且综合组颈椎功能情况及胸锁乳突肌、斜方肌上部纤维MPF、MF值的治疗效果均优于对照1组和对照2组,组间差异有统计学意义(P<0.05或P<0.01)。结论悬吊循经弹拨法结合麦肯基疗法能有效治疗颈型颈椎病,其效果优于单纯悬吊循经弹拨法和单纯麦肯基疗法,能更好地修复颈部软组织张力,实现生物力学平衡,恢复颈椎运动功能,因此临床上可推广此法治疗颈型颈椎病。