LC-MS/MS法同时测定消毒产品中6种抗生素残留

目的建立同时测定消毒产品中甲硝唑、盐酸金霉素、土霉素二水合物、盐酸米诺环素、红霉素及盐酸四环素的高效液相色谱-串联质谱(LC-MS/MS)检测方法。方法样品经甲醇超声提取,0.45μm聚四氟乙烯膜过滤后,选择WatersSymmetryC18(2.1mm×150mm,3.5μm)为分析柱,5mmol/L乙酸铵缓冲溶液、甲醇和乙腈为流动相,用LC-MS/MS正离子扫描多反应监测模式检测。结果上述6种抗生素在0～2000ng/ml范围内线性关系良好,相关系数均大于0.998,回收率为74.7%～114%,相对标准偏差为1.6%～20.2%。该法成功用于115件皮肤、黏膜使用的膏霜剂型抗(抑)菌制剂消毒产品中抗生素残留量的检测。结论该法操作简单,灵敏度高,选择性强,可用于膏霜剂型消毒产品中抗生素残留量的测定。     

Genistein prevents hyperglycemia-induced monocyte adhesion to human aortic endothelial cells through preservation of the cAMP signaling pathway and ameliorates vascular inflammation in obese diabetic mice

Hyperglycemia-induced vascular inflammation resulting in the enhanced monocyte-endothelial cell (EC) interaction is the key event in the pathogenesis of atherosclerosis in diabetes. Here, we investigated the effect of isoflavone genistein on hyperglycemia-stimulated vascular inflammation. Human aortic EC (HAEC) were pretreated with genistein before the addition of high glucose (HG; 25 mmol/L) for 48 h. Genistein at a physiological concentration (0.1 μmol/L) significantly inhibited HG-induced adhesion of monocytes to HAEC and suppressed endothelial production of monocyte chemotactic protein-1 (MCP-1) and IL-8. Inhibition of adenylate cyclase or protein kinase A (PKA) significantly attenuated the antiadhesion effect of genistein. Consistently, genistein improved HG-impaired intracellular cAMP production and PKA activity in HAEC. Six-week-old diabetic db/db mice were untreated (db/db) or treated with a diet containing 1 g genistein/kg diet (db/db+G) for 8 wk. Their nondiabetic db/+ mice were used as normal controls. Circulating concentrations of MCP-1/JE and KC were significantly greater, whereas IL-10 concentrations were lower in db/db mice than those in normal mice. Dietary supplementation of genistein did not normalize but significantly suppressed the elevated serum concentrations of MCP-1/JE from 286 ± 30 ng/L to 181 ± 35 ng/L and KC from 321 ± 21 ng/L to 232 ± 20 ng/L while increasing that of IL-10 from 35 ± 4 ng/L to 346 ± 35 ng/L in db/db+G mice. Further, genistein treatment suppressed diabetes-induced adhesion of monocytes to EC by 87% and endothelial secretion of adhesion molecules. We conclude that genistein improves diabetes-caused vascular inflammation, which may be mediated through promoting the cAMP/PKA pathway.     

HIV vaccine candidates generate in vitro T cell response to putative epitopes in Chinese-origin rhesus macaques

The Indian rhesus macaque is the established animal model for HIV infection and vaccine research. Growing evidence suggests that the more readily available Chinese rhesus macaque may be a more relevant option. As increasing numbers of novel Chinese rhesus MHC alleles are reported, we decided to explore potential HIV vaccine epitopes in this model. We immunized forty Chinese rhesus macaques with three different HIV vaccine candidates either individually or following a prime/boost strategy. We used ELISPOT to measure immune response in vitro to HIV-1 p24C and HIV-1 gp160 peptide libraries. We identified five putative epitopes with associations to HLA-I alleles including HLA*B-2705 and HLA-B*5101 (associated with slow disease progression and low viral set point) and HLA-B*18 (associated with rapid disease progression and high viral set point). This suggests the possible use of Chinese rhesus macaques to model different disease progressions. We also explored the use of fusion proteins as stimulators in ELISPOT assays. While PBMCs from 6 monkeys responded to peptide stimulation, PBMCs from 28 monkeys responded to the anthrax lethal factor fusion proteins LFn p24C and/or LFn gp140C. Our results support the use of Chinese rhesus macaques in HIV vaccine studies.     

Thermochemical properties and phase behavior of halogenated polycyclic aromatic hydrocarbons

Knowledge of vapor pressure of organic pollutants is essential in predicting their fate and transport in the environment. In the present study, the vapor pressures of 12 halogenated polycyclic aromatic compounds (PACs), 9-chlorofluorene, 2,7-dichlorofluorene, 2-bromofluorene, 9-bromofluorene, 2,7-dibromofluorene, 2-bromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 9,10-dibromophenanthrene, 1-chloropyrene, 7-bromobenz[a]anthracene, and 6,12-dibromochrysene, were measured using the Knudsen effusion method over the temperature range of 301 to 464?K. Enthalpies and entropies of sublimation of these compounds were determined via application of the Clausius-Clapeyron equation. The data were also compared with earlier published literature values to study the influence of halogen substitution on vapor pressure of PACs. As expected, the halogen substitution decreases vapor pressure compared with parent compounds but does not necessarily increase the enthalpy of sublimation. Furthermore, the decrease of vapor pressure also depends on the substitution position and the substituted halogen, and the di-substitution of chlorine and/or bromine decreases the vapor pressure compared with single halogen-substituted polycyclic aromatic hydrocarbons. In addition, the enthalpy of fusion and melting temperature of these 12 PACs were determined using differential scanning calorimetry and melting point analysis.     

Toxicological effect of joint cadmium selenium quantum dots and copper ion exposure on zebrafish

Quantum dots (QDs) have strong adsorption capacity; therefore, their potential toxicity to aquatic organisms from the facilitated transport of other trace toxic pollutants when they coexist has received increasing interest. However, the impact of cadmium selenium (CdSe) QDs and copper ion (Cu(2+) ) joint exposure on zebrafish (Danio rerio) embryo and larvae remains almost unknown. Therefore, the present study was performed to determine the developmental toxicities to zebrafish exposed to combined pollution with CdSe QDs (500?μg/L) and Cu(2+) (0, 0.1, 1, 10, and 100?μg/L CuC1(2) ) compared with single exposure. Our findings for the first time revealed that: (1) QDs facilitated the accumulation of Cu(2+) in zebrafish; (2) QDs caused higher mortality, lower hatch rate, and more malformations of the exposed zebrafish; (3) junction, bifurcation, crossing, particles, and aggregation of the exposed FLI-1 transgenic zebrafish larvae can be observed; (4) embryo cell apoptosis appeared in the head and tail region; and (5) synergistic effects played an important role during joint exposure. These observations provide a basic understanding of CdSe QDs and Cu(2+) joint toxicity to aquatic organisms and suggest the need for additional research to identify the toxicological mechanism. Environ. Toxicol. Chem. 2012; 31: 2117-2123. ? 2012 SETAC.     

Prevalence of low ankle brachial index and its association with pulse pressure in an elderly chinese population: a cross-sectional study

Background: We investigated the prevalence of low ankle brachial index (ABI) and the association of low ABI with pulse pressure among elderly community residents in China.Methods: This population-based cross-sectional study was conducted in Beijing and recruited 2982 participants who were aged 60 years or older in 2007. Low ABI was defined as an ABI value less than 0.9 in either leg. Participants with or without stroke or coronary heart disease (CHD) were analyzed separately. The association between pulse pressure and low ABI was examined by using multiple logistic regression models.Results: The prevalence of low ABI was 5.65% (4.24% among men and 6.52% among women; P = 0.0221) among participants without stroke or CHD and 10.91% (13.07% among men and 9.49% among women; P = 0.1328) among those with stroke or CHD. After adjusting for confounders, the odds ratio (95% CI) for each 5-mm Hg increase in pulse pressure was 1.19 (1.07, 1.33) and 1.10 (1.02, 1.20) for men and women, respectively, among participants without stroke or CHD and 1.17 (1.03, 1.34) and 1.15 (1.02, 1.30) for men and women with stroke or CHD. When pulse pressure was classified into quartiles and the lowest quartile was used as reference, the association between pulse pressure and low ABI remained positive in men and women.Conclusions: Low ABI was prevalent among elderly Chinese, and pulse pressure was positively associated with low ABI.     

Hypertriglyceridemic acute pancreatitis in a patient with Sheehan''''s syndrome

BACKGROUND: There is no report on case of severe acute hyperlipidemic pancreatitis after treatment of Sheehan's syndrome. METHODS: A 32-year-old female patient was diagnosed as having acute hyperlipidemic pancreatitis after treatment of Sheehan's syndrome, and treated with diet and lipidlowering agents in early stage. RESULTS: Abdominal pain and fever of the patient resolved within a few days. She was subjected to diet and oral lipid-lowering therapy on the 4th day after admission. The disease did not recur during the follow-up for more than one year. CONCLUSIONS: Estrogen replacement therapy should be prescribed for Sheehan's syndrome. The serum level of triglyceride should be monitored and treatment should be given to prevent severe acute pancreatitis. Lipid-lowering therapy in early stage is the key step towards a complete recovery.