Uncertainty of antioxidant profiling in complex mixtures using liquid chromatography involving post-column derivatisation

The main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data reported in the literature, we demonstrated that improper optimisation of temperature and/or pH assay conditions performed using an on-line derivatisation reactor may substantially change the antioxidant peaks ratio of targeted phytochemical compounds. It has been found that despite the relatively high stability of flavonoids at high temperature and under binary mobile phase HPLC conditions, the reaction of target compounds with common ABTS, FCR and DPPH radicals at elevated regions (particularly above 100 °C) dramatically changes their antioxidant activity values expressed, for example, as TEAC (Trolox equivalent antioxidant capacity) parameters. In principle, separation and detection processes of antioxidant profiling assay must not significantly affect the antioxidant activity of target compounds. In the case of foods eaten by humans or animals, critical experimental parameters such as pH and temperature concerning interaction of target analytes with derivatisation reagent should be as close as possible to the real physiological values.     

Internal exposure to organochlorine pollutants and cadmium and self-reported health status: A prospective study

In this paper, based on the Flemish biomonitoring programs, we describe the associations between internal exposure to organochlorine pollutants and to cadmium (measured in 2004–2005 for adults aged 50–65 years) and self-reported health status obtained through a questionnaire in November 2011. Dioxin-like activity in serum showed a significant positive association with risk of cancer for women. After adjustment for confounders and covariates, the odds ratio for an exposure equal to the 90th percentile was 2.4 times higher than for an exposure equal to the 10th percentile. For both men and women dioxin-like activity and serum hexachlorobenzene (HCB) showed a significant positive association with risk of diabetes and of hypertension. Detailed analysis suggested that an increase in BMI might be part of the mechanism through which HCB contributes to diabetes and hypertension. Serum dichlorodiphenyldichloroethylene (p,p′-DDE) concentration showed a significant positive association with diabetes and hypertension in men, but not in women. Serum polychlorinated biphenyl (PCB) 118 showed a significant positive association with diabetes in both men and women, and after adjustment for correlated exposures, also with hypertension in men. Urinary cadmium concentrations showed a significant positive association with hypertension. Urinary cadmium concentrations were (in 2004–2005) significantly higher in persons who felt in less than good health (in 2011) than in persons who felt in very good health. After adjustment for correlated exposures (to HCB, p,p′-DDE and PCB118) marker PCBs showed a significant negative association with diabetes and hypertension. Serum p,p′-DDE showed in men a significant negative association with risk of diseases based on atheromata. Our findings suggest that exposure to pollutants can lead to an important increase in the risk of diseases such as cancer, diabetes and hypertension. Some pollutants may possibly also decrease the risk of some health problems, although this requires confirmation by other approaches.     

新疆民族药的开发研究与前景展望

新疆地区药用植物资源颇为丰富，因其具有显著的药理活性，被广泛应用于新疆各民族药中，为新疆各族人民群众的生命健康和当地卫生事业提供一定保障。新疆各民族药呈现多元一体、和而不同、互相促进、共同发展的特点，共同构成我国传统医药学宝库中不可分割的部分，其中以维吾尔药、哈萨克药、柯尔克孜药、塔吉克药、塔塔尔药等最具地域特色，但新疆民族药产业发展较为滞后，有待于深入研究与开发利用。近年来，研究报道新疆民族药具有较高的药用价值，有着潜在的开发与研究价值，但由于民族药的实践经验流失、基础研究薄弱、品牌效应较弱、资源破坏严重等因素，严重制约了新疆民族药的发展。该文通过对新疆民族药的药用价值、发展现状、前景展望等方面进行初步分析与探讨，梳理新疆民族药现代化发展中存在的问题。以期为我国新疆民族药的临床应用和开发利用提供一定的科学参考依据，旨在促进新疆民族药产业的可持续化发展，弘扬我国传统医药文化。     

Evaluation of masticatory activity during unilateral single tooth clenching using muscle functional magnetic resonance imaging

Masticatory muscle activity during teeth clenching is affected by occlusal pattern. However, few studies have performed simultaneous evaluation of all masticatory activities during teeth clenching under various occlusal conditions. The aim of this study was to use muscle functional magnetic resonance imaging (mfMRI) to evaluate the effects of changes in occlusal point on masticatory activity during single tooth clenching. Changes in mean proton transverse relaxation time (?T2) as an index of activity in all masticatory muscles during left unilateral clenching at the first molar or first premolar for 1 min were examined in nine healthy volunteers. Bite force was maintained at 40% of the maximum voluntary clenching force. The ?T2 values of the masseter and lateral pterygoid muscles were analysed separately for superficial and deep layers, and for superior and inferior heads. The ?T2 values for the ipsilateral deep masseter were significantly lower, and for the superior head of the ipsilateral lateral pterygoid muscles were significantly higher, after left first premolar clenching compared to left first molar clenching. These results quantitatively demonstrate a significant increase in activity of the superior head of the ipsilateral lateral pterygoid muscle and a significant decrease in activity of the ipsilateral deep masseter muscle with forward displacement of the occlusal contact point during unilateral tooth clenching.     

Studies on the structure-activity relationship of caffeate derivatives as neuroprotective agents

In the present study, novel ester derivatives of CAPE were designed and synthesized as neuroprotective agents. The anti-inflammatory and antioxidant activities of these compounds were evaluated at the cellular level, while the blood-brain barrier (BBB) permeability was predicted by parallel artificial membrane permeability assay (PAMPA). The results revealed that phenolic hydroxyl groups and double bonds in the structure of CAPE had important effects on neuroprotective activities. Accordingly,a preliminary structure-activity relationship was summarized in this paper. In addition, we observed a significant improvement on BBB permeability. These results provided important references for the structural modification and optimization of CAPE in the future.     

Real-time assessment of bacteriophage T3-derived antimicrobial activity against planktonic and biofilm-embedded Escherichia coli by isothermal microcalorimetry

Bacterial biofilms, highly resistant to the conventional antimicrobial therapy, remain an unresolved challenge pressing the medical community to investigate new and alternative strategies to fight chronic implant-associated infections. Recently, strictly lytic bacteriophages have been revalued as powerful agents to kill antibiotic-resistant bacteria even in biofilm. Here, the interaction of T3 bacteriophage and planktonic and biofilm Escherichia coli TG1, respectively, was evaluated using isothermal microcalorimetry. Microcalorimetry is a non-invasive and highly sensitive technique measuring growth-related heat production of microorganisms in real-time. Planktonic and biofilm E. coli TG1 were exposed to different titers of T3 bacteriophage, ranging from 10² to 10⁷ PFU/ml. The incubation of T3 with E. coli TG1 showed a strong inhibition of heat production both in planktonic and biofilm already at lower bacteriophage titers (10³ PFU/ml). This method could be used to screen and evaluate the antimicrobial potential of different bacteriophages, alone and in combination with antibiotics in order to improve the treatment success of biofilm-associated infections.     

绍兴地区肺炎链球菌的血清型和耐药性

目的:调查绍兴地区流行肺炎链球菌的血清型和耐药性,对不同来源的菌株进行比较,计算PCV7的覆盖率,为临床用药提供指导。方法:收集105株不同样本来源的肺炎链球菌,使用Pneumotest-latex鉴定血清型,统计耐药性,并研究两者之间关系。结果:105株肺炎链球菌,青霉素不敏感仅1株咽拭子分离菌,红霉素、克林霉素耐药率为99.3%,未检到万古霉素、左氧氟沙星耐药株,复方SMZ、四环素、利福平、氯霉素的耐药率分别为77.9%、86.2%、5.1%、10.6%。主要检出的血清组/型为19和23,占所有菌株的47.6%(49/103),PCV疫苗覆盖率为62.1%。结论:不同样本来源的肺炎链球菌的流行血清型和耐药性差异有统计学意义,眼部分离肺炎链球菌较其他部位分离株耐药程度低,PCV7覆盖率低,需长期监测。     

Potato Disc Bioassay for Some Jordanian Medicinal Plants

Fifteen different plants representing different species, genera and families were used to test the effect of their aqueous extracts on tumor inhibition with a rapid, inexpensive, safe, animal sparing technique, and statistically reliable prescreen for in vivo murine leukemia antitumor activity, which is known as potato disc technique. The inoculum used contains the extract with the bacterium (Agrobacterium tumefaciens) that was known to cause crown gall tumor to different plant species especially dicotyledons and some gymnosperms. After 12 to 21 days of incubation the tumors appeared and were counted, and the maximum inhibition was then calculated. Thirteen species out of fifteen showed a good antitumor effect, and three of them showed a maximum inhibition of 80%. More experiments are necessary to determine the exact mechanism of action.     

Anti-Diarrheal Activity and Toxicity of Learng Pid Samud Recipe

Learng Pid Samud (LPS) recipe is a traditional remedy in Thai folk medicine to ease the common diarrhea. The anti-diarrheal potential of LPS recipe was herein examined in vitro using a guinea-pig ileum model. The LPS exerted an inhibitory effect on acetylcholine-induced smooth muscle contraction in the guinea pig ileum. Significantly, not only did the LPS reduce the total amount of feces in the induced diarrhea rats, but also the intestinal transit in the charcoal meal test. A single oral administration with the recipe at 5,000 mg/kg did not cause acute toxicity and the daily oral administration (1,000, 2,000 and 4,000 mg/kg) for 90 days in rats did not produce any toxic signs and symptoms. In conclusion, the Learng Pid Samud recipe remedy is evidently safe and effective for the anti-diarrheal treatment which supports its therapeutic uses in the alternative medicine.