At-Risk Serum Cholesterol Profile at Both Ends of the Nutrition Spectrum in West African Adults? The Benin Study

Low HDL-cholesterol (HDL-C), using as cut-offs 1.03 mmol/L in men and 1.29 mmol/L in women, was observed in more than 25% apparently healthy adults (n = 541) in a cross-sectional study on nutrition transition and cardiometabolic risk factors (CMRF) in Benin, West Africa. Both overweight/obesity (35.3%) and underweight (11.3%) were present, displaying the double burden of malnutrition. We examined in more depth the association of low HDL-C with nutrition and with other CMRF. Metabolic syndrome components were assessed, plus the ratio of total cholesterol (TC)/HDL-C and serum homocysteine. Insulin resistance was based on Homeostasis Model Assessment. We also measured BMI and body composition by bio-impedance. Dietary quality was appraised with two non-consecutive 24 h recalls. Low HDL-C was associated with much higher TC/HDL-C and more abdominal obesity in men and women and with more insulin resistance in women. The rate of low HDL-C was highest (41.9%) among the overweight/obese subjects (BMI ≥ 25), but it also reached 31.1% among the underweight (BMI < 18.5), compared with 17.3% among normal-weight subjects (p < 0.001). Lower dietary micronutrient adequacy, in particular, in vitamins A, B₃, B_12, zinc and calcium, was associated with low HDL-C when controlling for several confounders. This suggests that at-risk lipoprotein cholesterol may be associated with either underweight or overweight/obesity and with poor micronutrient intake.     

Toxicity of thallium on isolated rat liver mitochondria: The role of oxidative stress and MPT pore opening

Thallium(I) is a highly toxic heavy metal; however, up to now, its mechanisms are poorly understood. The authors' previous studies showed that this compound could induce reactive oxygen species (ROS) formation, reduced glutathione (GSH) oxidation, membrane lipid peroxidation, and mitochondrial membrane potential (MMP) collapse in isolated rat hepatocyte. Because the liver is the storage site of thallium, it seems that the liver mitochondria are one of the important targets for hepatotoxicity. In this investigation, the effects of thallium on mitochondria were studied to investigate its mechanisms of toxicity. Mitochondria were isolated from rat liver and incubated with different concentrations of thallium (25–200 µM). Thallium(I)‐treated mitochondria showed a marked elevation in oxidative stress parameters accompanied by MMP collapse when compared with the control group. These results showed that different concentrations of thallium (25–200 µM) induced a significant (P < 0.05) increase in mitochondrial ROS formation, ATP depletion, GSH oxidation, mitochondrial outer membrane rupture, mitochondrial swelling, MMP collapse, and cytochrome c release. In general, these data strongly supported that the thallium(I)‐induced liver toxicity is a result of the disruptive effect of this metal on the mitochondrial respiratory complexes (I, II, and IV), which are the obvious causes of metal‐induced ROS formation and ATP depletion. The latter two events, in turn, trigger cell death signaling via opening of mitochondrial permeability transition pore and cytochrome c expulsion. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 232–241, 2015.     

The polycomb group protein enhancer of zeste 2 is a novel therapeutic target for cervical cancer

Enhancer of zeste 2 (EZH2), a polycomb histone methyltransferase, is overexpressed in various cancers, including cervical cancer. Gene expression analysis revealed that increased expression of EZH2 is associated with cervical cancer progression, particularly the progression to invasive squamous cell carcinoma. Enhancer of zeste 2 is known to trimethylate lysine 27 on histone H3, leading to gene silencing that contributes to the progression of tumours into a more aggressive form of cancer. However, the specific molecular mechanisms by which EZH2 contributes to the development of cervical cancer remain largely unknown. Recently, an EZH2 inhibitor was reported to selectively inhibit trimethylated lysine 27 on histone H3 and to reactivate silenced genes in cancer cells. In this study, we found that GSK343 (a specific inhibitor of EZH2 methyltransferase) induces phenotypic reprogramming of cancer cells from mesenchymal to epithelial cells, reducing proliferation and cell motility and blocking the invasion of cervical cancer cell lines both in vitro and in vivo. Treatment with the EZH2 inhibitor led to increased levels of the epithelial marker E‐cadherin and decreased levels of mesenchymal markers such as N‐cadherin and vimentin. The observed reprogramming is associated with restrained cervical cancer progression and provides direct evidence in support of EZH2 as a therapeutic target.     

The effect of Fe2O3 and ZnO nanoparticles on cytotoxicity and glucose metabolism in lung epithelial cells

Metallic nanoparticles (NPs) have potential applications in industry and medicine, but they also have the potential to cause many chronic pulmonary diseases. Mechanisms for their cytotoxicity, glucose and energy metabolism responses need to be fully explained in lung epithelial cells after treatment with metallic nanoparticles. In our study, two different metallic nanoparticles (Fe₂O₃ and ZnO) and two cell‐based assays (BEAS‐2B and A549 cell lines) were used. Our findings demonstrate that ZnO nanoparticles, but not Fe₂O₃ nanoparticles, induce cell cycle arrest, cell apoptosis, reactive oxygen species (ROS) production, mitochondrial dysfunction and glucose metabolism perturbation, which are responsible for cytotoxicity. These results also suggest that the glucose metabolism and bioenergetics had a great potential in evaluating the cytotoxicity and thus were very helpful in understanding their underlying molecular mechanisms. Copyright © 2015 John Wiley & Sons, Ltd.     

Mechanism of adrenocortical toxicity induced by quinocetone and its bidesoxy-quinocetone metabolite in porcine adrenocortical cells in vitro

Quinocetone (QCT) is a new feeding antibacterial agent in the QdNOs family. The mechanism of its adrenal toxicity is far from clear. This study was conducted to estimate the adrenal cell damage induced by QCT and its bidesoxy-quinocetone (B-QCT) metabolite and to further investigate their mechanisms. Following doses of QCT increasing from 5 to 50 μM, cell apoptosis and necrosis, mitochondrial dysfunction and redox imbalance were observed in porcine adrenocortical cells. The mRNA levels of the six components of intermediary enzymes and the adrenal renin-angiotensin-aldosterone system (RAAS) displayed a dysregulation induced by QCT, indicating that QCT might influence aldosterone secretion not only through the upstream of the production but also through the downstream of the adrenal RAAS pathway. In contrast, B-QCT had few toxic effects on the cell apoptosis, mitochondrial dysfunction and redox imbalance. Moreover, LCMS-IT-TOF analysis showed that no desoxy metabolites of QCT were found in either cell lysate or supernatant samples. In conclusion, we reported on the cytotoxicity in porcine adrenocortical cells exposed to QCT via oxidative stress, which raised awareness that its toxic effects resulted from N→O groups, and its toxic mechanism might involve the interference of the steroid hormone biosynthesis pathway.     

Applicability of the one-step DVS method for the determination of amorphous amounts for further different hydrophilic and hydrophobic drugs

In a former publication the authors showed that low amounts of amorphous content (LOQ of 0.5%) in a hydrophobic model API (Ciclesonide) can be measured with an individually adjusted one-step dynamic organic vapor sorption (DVS). In this investigation the applicability is tested on various APIs which differ in lipophilicity (poor water solubility) and hygroscopicity (absorption of water).The vapor sorption method proved to be applicable in almost all cases. Moisture sorption isotherms were determined for all five investigated crystalline and amorphous APIs. However, it was necessary to select the parameters individually for each API. The used solvents (water, methanol, isopropanol and methylene chloride) and the humidity-levels (0.05 p/p₀ until 0.5 p/p₀) were chosen carefully because otherwise the amorphous amounts switch to their crystalline counterparts and are not detectable. The production of fully amorphous samples (absence of crystalline material measured by DSC, mDSC and XRPD) was optimized over several trials. As successfully methods proved ball-milling, freeze-drying, spray-drying and/or quench cooling. In the next step these fully amorphous amounts were blended with crystalline starting material to calibration curves (Turbula blender, influence of electrostatic charge to homogeneity) for the calculation of amorphous content.In summary, the following presented methods were used to determine and quantify low amorphous amounts (between 1.5% and 17.0%) in jet-milled powders (grinding pressure of 8 bar, 1–3 grinding cycles), respectively.     

8-(N,N-二乙铵)-n-辛基-3,4,5-三甲氧基苯甲酸酯对谷氨酸诱导神经细胞DNA损伤的影响

目的研究 8 (N ,N 二乙铵 ) n 辛基 3,4 ,5 三甲氧基苯甲酸酯 (TMB 8)对谷氨酸诱导神经细胞DNA损伤的影响。方法用谷氨酸诱导培养的大鼠皮层神经细胞DNA断裂 ,观察TMB 8对神经细胞DNA断裂和线粒体功能的影响。结果TMB 8能明显减轻谷氨酸诱导的大鼠皮层神经细胞DNA断裂并能改善线粒体功能。结论TMB 8具有抑制神经细胞DNA损伤的作用 ,其机制可能与其降低细胞内游离钙、改善线粒体功能和减轻谷氨酸的氧化毒性有关     

骨肌康搽剂治疗软组织损伤的机理探讨

目的 :研究骨肌康搽剂“GJKL”对软组织损伤治疗作用的机理。方法 :腹腔注射醋酸溶液 ,观察对毛细血管通透性的影响 ;造成动物软组织损伤 ,观察血液流变学指标的变化。结果 :GJKL能明显抑制毛细血管通透性增加 ;能明显降低血液流变学指标。结论 :GJKL通过抑制软组织损伤时毛细血管通透性增加及降低血液流变学指标而治疗软组织损伤     

三氧化二砷诱导肿瘤细胞凋亡途径的研究

目的　探讨细胞线粒体跨膜电位 (Δψm)和半胱氨酶3(Caspase 3)在三氧化二砷 (As2 O3 )诱导肿瘤细胞凋亡过程中的作用。方法　以Namalwa、SGC790 1和Bcap37细胞为体外模型 ,流式细胞仪检测亚G1期细胞含量和细胞膜磷脂酰丝氨酸 (PS)外翻量等方法鉴定细胞凋亡 ;碘化丙啶 (PI) /Rhodamine(Rh12 3)双染色检测Δψm变化并观察了Caspase 3抑制剂DEVD CHO对As2 O3 诱导肿瘤细胞凋亡的影响。结果　As2 O3 诱导肿瘤细胞凋亡效应与其诱导细胞Δψm下降和Caspase 3活性升高相关 ,抑制Caspase 3活性后As2 O3 使细胞选择坏死通路。结论　As2 O3 可能通过诱导细胞Δψm下降激活Caspase 3并最终使肿瘤细胞凋亡。