The role of Ntcp,Oatp2, Bsep and Mrp2 in liver injury induced by Dioscorea bulbifera L. and Diosbulbin B in mice

Dioscorea bulbifera L. (DB) is a traditional Chinese herb used in thyroid disease and cancer. However, the clinical use of DB remains a challenge due to its hepatotoxicity, which is caused, in part, by the presence of Diosbulbin B (DIOB), a toxin commonly found in DB extracts. As abnormal expression of hepatobiliary transporters plays an important role in drug-induced liver injury, we assessed the hepatotoxicity induced by DB and DIOB, and explored their impacts on hepatobiliary transporter expression levels. Following liquid chromatography-tandem mass analysis of the DIOB content of DB extract, male ICR mice were randomly orally administered DB or DIOB for 14 days. Liver injury was assessed by histopathological and biochemical analysis of liver fuction. The levels of transporter protein and mRNA were determined by western blotting and real-time PCR. Liver function and histopathological analysis indicated that both DB and DIOB could induce liver injury in mice, and that DIOB might be the primary toxic compound in DB. Moreover, down-regulation of Mrp2 blocked the excretion of bilirubin, glutathione disulfide, and bile acids, leading to the accumulation of toxic substrates in the liver and a redox imbalance. We identified down-regulated expression of Mrp2 as potential factors linked to increased serum bilirubin levels and decreased levels of glutathione in the liver and increased liver injury severity. In summary, our study indicates that down-regulation of Mrp2 represents the primary mechanism of DB- and DIOB-induced hepatotoxicity, and provides insight into novel therapies that could be used to prevent DB- and DIOB-mediated liver injury.     

NMR测定丹酚酸B标准品中有机溶剂残留

[目的] 用定量核磁共振(QNMR)技术建立中药来源的标准品化合物丹酚酸B中残留甲醇、乙醇和乙酸含量的快速分析方法。[方法] 采用BRUKER AVANCEⅢ 600型超导核磁共振波谱仪采集谱图, 观频率600.23 MHz,测定温度298 K.谱宽12 019.2 Hz,采样数据点65 536,扫描次数16次, 延迟时间15 s.[结果] 所有标准曲线在1.22~2 430 mg/L范围内线性良好(r²>0.999 5),平均回收率(n=6)在 105%~109%之间。[结论] 本方法快速、准确, 可应用于样品有机溶剂残留的检测。     

毛细管气相色谱法测定酒石酸托特罗定中有机溶剂的残留量

摘 要 目的： 建立毛细管气相色谱法测定酒石酸托特罗定中8种有机溶剂残留量的方法。 方法: 采用CP sil 5CB色谱柱（60.0 m×0.32 mm,5 μm）;进样口温度为200℃;FID检测器温度为250℃;载气流速为1.2 ml·min^-1;柱温120℃;顶空瓶平衡温度85℃,时间30 min,以二甲基甲酰胺 水（1∶4）混合溶液为溶解介质,测定酒石酸托特罗定中甲醇,乙醇,乙腈,丙酮,乙酸乙酯,三氯甲烷和四氢呋喃的残留量;采用HP 1色谱柱（30.0 m×0.53 mm,5 μm）,进样口温度为220℃;FID检测器温度为250℃;载气流速为3.0 ml·min^-1;柱温80℃;顶空瓶平衡温度85℃,时间30 min,以二甲亚砜 氢氧化钠溶液（17∶13）混合溶液为溶解介质,测定酒石酸托特罗定中吡啶的残留量。结果:在各色谱条件下,被测溶剂峰之间均分离良好,8种溶剂的标准曲线线性良好,相关系数均大于0.999;平均回收率为86.0%～100.2%,RSD为1.7%～3.5%(n=9);甲醇,乙醇,乙腈,丙酮,乙酸乙酯,三氯甲烷,四氢呋喃和吡啶的检测限分别为0.63,0.43,0.30,0.18,0.079,0.36,0.18,0.89 μg·ml^-1。结论: 该法适用于酒石酸托特罗定中这8种有机溶剂残留量的测定。     

气相色谱法测定厄贝沙坦中9种残留溶剂

目的:建立厄贝沙坦原料药中9种残留溶剂(甲醇,乙醇,丙酮,异丙醇,乙腈,二氯甲烷,甲基叔丁基醚,乙酸乙酯及甲苯)的检测方法。方法:色谱柱为Kromat KB-624(30 m×0.53 mm,3.0μm);程序升温;载气为氮气,流速为5.0 ml·min-1;进样口温度为200℃;检测器为氢火焰离子化检测器,检测器温度为250℃;顶空进样,顶空瓶平衡温度为80℃,平衡时间20min。以二甲基亚砜为溶剂,用外标法测定9种残留溶剂的量,进样量为1 ml。结果:在本色谱条件下,9种残留溶剂分离良好。在各自的浓度范围内线性关系良好(r≥0.999 1),平均回收率为99.08%~105.14%,RSD为1.1%~3.3%(n=9);定量限分别为15.68,25.45,1.09,10.61,4.54,5.73,1.04,10.58,1.89μg。结论:本方法简便,准确,重复性好,可用于厄贝沙坦原料药中多种残留溶剂的同时测定。     

顶空气相色谱法测定硝酸芬替康唑原料药中有机溶剂残留量

目的：：建立测定硝酸芬替原料药中二氯甲烷、甲醇和乙醇3种有机溶剂残留量的分析方法。方法：采用毛细管气相色谱法,色谱柱：OV-1301毛细管色谱柱(30 m ×0.53 mm,3.0μm),检测器：FID;检测器温度：250℃;进样器温度：200℃;载气：氮气;顶空进样。结果：在上述色谱条件下,二氯甲烷、甲醇和乙醇分别在2.436~21.924μg·ml-1(r=0.9988),12.268~110.412μg·ml-1(r=0.9995),20.052~180.468μg·ml-1(r=0.9969)质量浓度范围内线性关系良好。平均回收率分别为99.30%(RSD=2.36%,n=9),100.21%(RSD=1.07%, n=9),100.15%(RSD=1.27%, n=9)。结论：该检测方法灵敏、准确、可靠,可用于硝酸芬替康唑原料药的质量控制。     

Primary Sjögren's syndrome and occupational risk factors: A case–control study

ObjectivesA case–control study was carried out to investigate the relation between primary Sjögren's syndrome (pSS) and occupational exposure.MethodsOne hundred seventy five cases of pSS followed up into the internal medicine departments of three French university hospitals from 2010 to 2013 were included. For each case, two age and gender matched controls were selected during the same period in the same departments. Occupational exposure was assessed retrospectively by industrial hygienists and occupational practitioners. Exposure to occupational factors such as organic solvents or silica was investigated using semiquantitative estimates of exposure. An exposure score was calculated for each subject based on probability, intensity, daily frequency, and duration of exposure for each period of employment. The final cumulative exposure score was obtained, taking into account all periods of employment.ResultsSignificant associations with pSS were observed for dichloromethane (OR 9.28, 95%CI 2.60–33.03), perchlorethylene (OR 2.64, 95%CI 1.20–5.77) chlorinated solvents (OR 2.95, 95%CI 1.77–4.93), benzene (OR 3.30, 95%CI 1.07–10.26), toluene (OR 4.18 95%CI 1.41–12.43), white spirit (OR 3.60, 95%CI 1.39–9.33), aromatic solvents (OR 3.03, 95%CI 1.41–6.50) and any types of solvents (OR 2.76, 95%CI 1.70–4.47). Risk of pSS was significantly associated with a high cumulative exposure score of occupational exposure to toluene (OR 4.69, 95%CI 1.42–15.45), white spirit (OR 3.30, 95%CI 1.07–10.26), aromatic solvents (OR 2.50, 95%CI 1.06–5.91) and any types of solvents (OR 2.25, 95%CI 1.20–4.22).ConclusionThis work suggests the influence of occupational risk factors in the occurrence of pSS.     

Hydrogen‐Bonding Effects for the C–ON Bond Homolysis and Reformation Reactions of Alkoxyamines

N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐O‐(2‐carboxyprop‐2‐yl) hydroxylamine (BlocBuilder MA) is, among the commercially available alkoxyamines, one of the most efficient for nitroxide‐mediated polymerization (NMP). However, recent results have shown that it does not perform well for the NMP of isoprene. The occurrence of intramolecular hydrogen bonding (IHB) between the carboxylic function and the diethoxyphosphoryl group has been proposed as the reason for its low efficiency. In this article, the presence of this IHB is confirmed using IR, ³¹P NMR, ³¹P‐¹H HOESY, and DFT calculation results. The solvent effect on this IHB and consequently on k_d values is also investigated. However, combining kinetic analysis and rate measurements in various solvents, the influence of this IHB on the C? ON bond homolysis and reformation in alkoxyamine is shown to be very weak.

     

Solvent and Steric Hindrance Effects of Bulky Poly(9,9‐diarylfluorene)s on Conformation,Gelation, Morphology,and Electroluminescence

Clarification of the solvent effects of bulky π‐conjugated polymers on the conformation behavior and morphology evolution of the chain from solution to thin film is the main prerequisite for the molecular design of printable polymer light‐emitting materials. Here, three bulky poly(9,9‐diarylfluorene)s (PFs) with the steric hindrance effect are synthesized to examine gelation behaviors, β‐phase conformation, film morphology, and electroluminescence (EL) spectra in three solvents. Their gelation behaviors occur in 1,2‐dichloroethane (DCE) of high concentrations, featuring emission bands of ≈470 nm as well as the β‐phase conformation. Bulky PFs also exhibit different solvent effects on the morphology and green emission bands. Compared with other bulky PFs, poly(spirofluorenexanthene)s have obvious advantages in terms of the solvent‐independent emission, high quantum yield, and air‐stable photoluminescence, as well as the EL spectra. Poly(SFX) will be potential components for the formula of optical inks in printed electronics.

     

Energetics and Mechanism of Conformational Transitions of Protein‐Like NIPAM‐Sodium Styrene Sulfonate Copolymers in Aqueous Solutions

Protein‐like and random NIPAM‐sodium styrene sulfonate copolymers of similar composition have been prepared by radical polymerization in water at temperatures above and below the LCST of PNIPAM, respectively. Thermal transitions of the copolymers in aqueous solutions have been studied by means of dynamic light scattering, viscometry, and high‐sensitivity differential scanning calorimetry. The phase separation or cooperative conformational transitions without phase separation were observed for the random or the protein‐like copolymers, respectively. Transition temperature, enthalpy, and heat capacity increment of the protein‐like copolymer differed insignificantly from those of the random copolymer of similar composition. The transition heat capacity increments of the protein‐like copolymers revealed that only 10–20% of their NIPAM links participate in the formation of a dense water‐free globule core. The coil–globule transitions of the protein‐like copolymers were described by the thermodynamic three‐state model according to the scheme “random coil?condensed coil?globule”, which is known to simulate the folding mechanism of globular proteins.

     

Toxic trace elements at gastrointestinal level

Many trace elements are considered essential [iron (Fe), zinc (Zn), copper (Cu)], whereas others may be harmful [lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As)], depending on their concentration and chemical form. In most cases, the diet is the main pathway by which they enter our organism. The presence of toxic trace elements in food has been known for a long time, and many of the food matrices that carry them have been identified. This has led to the appearance of legislation and recommendations concerning consumption. Given that the main route of exposure is oral, passage through the gastrointestinal tract plays a fundamental role in their entry into the organism, where they exert their toxic effect. Although the digestive system can be considered to be of crucial importance in their toxicity, in most cases we do not know the events that occur during the passage of these elements through the gastrointestinal tract and of ascertaining whether they may have some kind of toxic effect on it. The aim of this review is to summarize available information on this subject, concentrating on the toxic trace elements that are of greatest interest for organizations concerned with food safety and health: Pb, Cd, Hg and As.