Aldehyde dehydrogenase 2 deficiency significantly exacerbates tert-butyl alcohol-induced toxicity in mice

Owing to the use of ethyl tert-butyl ether (ETBE) as a fuel additive, the possible adverse effects of ETBE exposure have become a public concern. Our previous study showed that ETBE-induced toxicity in aldehyde dehydrogenase 2 (Aldh2) gene knockout (KO) mice was caused by its primary metabolite acetaldehyde, which was toxic. However, it is unclear whether tert-butyl alcohol (TBA), another main metabolite of ETBE, plays a role in ETBE-induced toxicity. To investigate this relationship, we analyzed the changes of TBA concentrations in tissues after ETBE exposure, and then evaluated the toxicity after direct TBA treatment in both KO and wild-type (WT) mice. An exposure to 500 ppm ETBE via inhalation resulted in the formation of its three metabolites, TBA, 2-methyl-1,2-propanediol and ethanol, whose concentrations in the liver, brain, fat and testis of male KO mice were significantly higher than the corresponding concentrations observed in male WT mice. Direct treatment to TBA (20 mg/mL of drinking water) caused significant changes in relative organ weights and histopathology, and increased levels of genetic damages in both types of mice. These toxic effects were also seen in KO mice exposed to a lower concentration of TBA (5 mg/mL), which was associated with increased oxidative stress in serum (reduced glutathione and reduced glutathione/oxidized glutathione ratio decreased). Our findings indicate that ALDH2 is involved in the metabolism of ETBE and TBA, and ALDH2 deficiency could greatly increase the sensitivity to TBA-induced toxicity.     

顶空气相色谱-质谱法测定布南色林原料药中遗传毒性杂质

目的：建立顶空气相色谱-质谱法测定布南色林原料药中甲磺酸甲酯、甲磺酸乙酯和甲磺酸异丙酯3种遗传毒性杂质含量的方法。方法：采用顶空气相色谱-质谱法，以甲磺酸丁酯为内标，按内标标准曲线法进行甲磺酸甲酯、甲磺酸乙酯和甲磺酸异丙酯的含量测定。色谱条件：DB-WAX毛细管色谱柱（30 m×0.25 mm×0.25 μm）；程序升温，初始柱温为40℃，维持3 min，升温速率为30℃·min^-1，终止温度150℃，保持2 min；进样口温度为110℃；载气（He）流速为0.6 mL·min^-1；进样量为1 mL；进样方式为分流进样，分流比为20：1。质谱条件：电子轰击离子源（EI），扫描方式为选择性离子检测；离子源温度为200℃；接口温度为150℃；电子能量为70 eV；溶剂延迟1 min。结果：3种杂质成分之间的分离度均大于2.0；甲磺酸甲酯、甲磺酸乙酯、甲磺酸异丙酯检测质量浓度线性范围均为0.025~3.0 μg·mL^-1（r ≥ 0.998 5）；精密度、稳定性、重复性试验的RSD<5%；加样回收率分别为93.40%~101.40%（RSD为3.2%，n=9）、92.80%~99.70%（RSD为2.5%，n=9）和96.30%~100.75%（RSD为1.6%，n=9）。结论：该方法简便、准确、灵敏、迅速，可用于布南色林原料药中3种遗传毒性杂质的测定。     

5-对氟苄氧基杨梅醇对人肺腺癌A549-Homo BIRC5体内增殖的抑制作用及机制研究

目的 研究5-对氟苄氧基杨梅醇(myricanol 5-fluorobenzyloxy ether,5FEM)对人肺腺癌A549-Homo BIRC5体内增殖的抑制作用及机制。方法 构建A549-Homo BIRC5裸鼠移植瘤模型,随机分为模型组、溶剂(聚乙二醇400,2.5 mL·kg^-1)组和5FEM低、中、高剂量(20,40,80 mg·kg^-1)组,每组8只。各组每日腹腔注射给药,连续5周,每周测量移植瘤体积用于绘制肿瘤生长曲线,实验结束后处死裸鼠,剥离瘤体并称重。TUNEL法检测移植瘤组织细胞凋亡情况;RT-qPCR测定移植瘤组织中Caspase-9、PARP、Bax、Bcl-2和Survivin的mRNA表达水平;ELISA法检测瘤组织中Caspase-9、Survivin和PARP蛋白含量;免疫组化法检测瘤组织中Survivin、Caspase-9、Cleaved caspase-9、PARP和Cleaved PARP蛋白水平。结果 与模型组相比,5FEM(20,40,80 mg·kg^-1)能够显著减小移植瘤体积和减轻瘤重,呈一定剂量依赖性。TUNEL染色结果显示5FEM干预后肿瘤细胞凋亡较模型组明显增多。RT-qPCR结果显示,5FEM(20,40,80 mg·kg^-1)可以诱导瘤组织中Caspase-9和Bax的mRNA表达显著升高,并诱导Bcl-2、PARP和Survivin的mRNA表达降低。ELISA结果显示,5FEM(40,80 mg·kg^-1)可以显著增加瘤组织中Caspase-9蛋白表达量,并显著降低瘤组织中PARP和Survivin蛋白的表达量。免疫组化结果显示,5FEM(80 mg·kg^-1)处理后瘤组织中Caspase-9、Cleaved caspase-9和Cleaved PARP蛋白表达均显著升高,而PARP和Survivin蛋白表达被不同程度抑制。结论 5FEM可下调Survivin表达,促进Caspase-9和PARP活化,诱导肿瘤细胞凋亡,抑制肺腺癌A549-Homo BIRC5裸鼠移植瘤生长。     

Effect of micro-roughening of poly(ether ether ketone) on bone marrow derived stem cell and macrophage responses,and osseointegration

Poly(ether ether ketone) (PEEK) has emerged as a candidate to replace metal implants because of its satisfactory mechanical properties, radiolucency, and lack of metal allergy. However, PEEK lacks osseointegration ability limiting its clinical applications. To overcome this problem, we prepared PEEK with a micro-rough surface using the sandblast method to modulate its osseointegration property; the sandblast method is simple, cost-effective, and is already applied to clinical metal implants. The surface roughness of the sandblasted PEEK was about 2.3 μm, whereas that of mirror-polished PEEK was 0.06 μm. Rat bone marrow-derived mesenchymal stem cells (RMSCs) showed higher proliferation, osteocalcin (OC) expression and bone-like nodule formation on micro-roughened PEEK compared with those cultured on mirror-polished PEEK, suggesting that micro-roughening facilitated RMSCs proliferation and differentiation. The micro-roughened surface slightly mitigated secretion of inflammatory C-C motif chemokine 2 (CCL-2) from lipopolysaccharide (LPS)-stimulated macrophages, but not of tumor necrosis factor α (TNFα) and interleukin-6 (IL-6). Finally, to compare osseointegration, specimens were implanted in rat femur bone marrow cavities, and then the pull-out force was measured. The pull-out force of micro-roughened PEEK was about four times higher than that of the mirror-polished PEEK. These results showed that micro-roughening of PEEK using the sandblast method was able to improve osseointegration, partly through elevating proliferation and differentiation of RMSCs.     

Cutis laxa,exocrine pancreatic insufficiency and altered cellular metabolomics as additional symptoms in a new patient with ATP6AP1-CDG

Congenital disorders of glycosylation (CDG) are genetic defects in the glycoconjugate biosynthesis. > 100 types of CDG are known, most of them cause multi-organ diseases. Here we describe a boy whose leading symptoms comprise cutis laxa, pancreatic insufficiency and hepatosplenomegaly. Whole exome sequencing identified the novel hemizygous mutation c.542 T > G (p.L181R) in the X-linked ATP6AP1, an accessory protein of the mammalian vacuolar H⁺-ATPase, which led to a general N-glycosylation deficiency. Studies of serum N-glycans revealed reduction of complex sialylated and appearance of truncated diantennary structures. Proliferation of the patient's fibroblasts was significantly reduced and doubling time prolonged. Additionally, there were alterations in the fibroblasts' amino acid levels and the acylcarnitine composition. Especially, short-chain species were reduced, whereas several medium- to long-chain acylcarnitines (C14-OH to C18) were elevated. Investigation of the main lipid classes revealed that total cholesterol was significantly enriched in the patient's fibroblasts at the expense of phophatidylcholine and phosphatidylethanolamine. Within the minor lipid species, hexosylceramide was reduced, while its immediate precursor ceramide was increased. Since catalase activity and ACOX3 expression in peroxisomes were reduced, we assume an ATP6AP1-dependent impact on the β-oxidation of fatty acids. These results help to understand the complex clinical characteristics of this new patient.     

Design,Synthesis, and Biological Activity of Oxime Ether Strobilurin Derivatives Containing Indole Moiety as Novel Fungicide

Twenty‐one novel oxime ether strobilurins containing indole moiety, which employed an indole group to stabilize the E‐styryl group in Enoxastrobin, were designed and synthesized. The biological assay indicated that most compounds exhibited potent fungicidal activities. The structure–activity relationship study demonstrated that the synthesized methyl 3‐methoxypropenoate oxime ethers 7b–e exhibited remarkably high activities among all the synthesized oxime ether compounds 7 . Moreover, the fungicidal activities of methyl α‐(methoxyimino)benzeneacetate oxime ethers compounds 7f–i and N‐methoxy‐carbamic acid methyl esters compounds 7j–m showed significant differences compared to the corresponding products of ammonolysis.     

The Effect of Zeolite Features on the Dehydration Reaction of Methanol to Dimethyl Ether: Catalytic Behaviour and Kinetics

The synthesis of dimethyl ether (DME) is an important step in the production of chemical intermediate because it is possible to prepare it by direct hydrogenation of CO₂. This paper reports the effect of different zeolitic frameworks (such as: BEA, EUO, FER, MFI, MOR, MTW, TON) on methanol conversion, DME selectivity and catalyst deactivation. The effect of crystal size, Si/Al ratio and acidity of the investigated catalysts have been also studied. Finally, the kinetic parameters (such as: ∆H, ∆S and ∆G) have been evaluated together with pre-exponential factor and activation energy for catalysts with FER and MFI structure topology.     

Disturbance of zinc and glucose homeostasis by methyl tert-butyl ether (MTBE); evidence for type 2 diabetes

1.?The prevalence of diabetes and the other metabolic disorders has noticeably increased worldwide. A causal link between increasing risk of type 2 diabetes and exposure to environmental pollutants has been reported.

2.?We hypothesized that exposure to methyl tert-butyl ether (MTBE), an oxygenate additive to gasoline would hinder zinc and glucose homeostasis in rats.

3.?Male Sprague–Dawley rats received MTBE in drinking water for 90 days. At the end of the treatment, pancreas and blood samples were collected for biochemical and molecular examinations. Expression of four candidate genes, including Insulin1, Insulin2, MT1A, SLC30A8 by Real-Time Quantitative PCR (Q-PCR) as well as biochemical parameters, including fasting blood glucose (FBS), triglycerides (TG), cholesterol (CHO), low-density lipoprotein (LDL), high-density lipoprotein (HDL), copper (Cu²⁺) and calcium (Ca²⁺) levels as well as High-sensitive C-reactive protein were assessed as endpoints.

4.?This study suggested that MTBE exposure can be associated with disruption in zinc homeostasis and glucose tolerance.     

Gentamicin and leucine inhalable powder: What about antipseudomonal activity and permeation through cystic fibrosis mucus?

The aim of this study was to evaluate the permeation properties of gentamicin (G) in a novel dry powder form for inhalation through an artificial mucus model. Moreover, since respiratory infections sustained by Pseudomonas are a major cause of sickness and death in CF patients, the susceptibility of P. aeruginosa to engineered G powders was investigated.