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1.
《Dental materials》2021,37(12):1834-1844
ObjectiveThe biocompatibility of resin based dental composites has not yet been fully characterized even though certain monomers used in these composites are synthesized from Bisphenol A (BPA), a well-known estrogenic endocrine disruptor. As a result, they show structural relationship to BPA and can contain it as an impurity. Therefore, the estrogenic activity of 9 monomers, 2 photoinitiators, one photostabilizer and leachates of 4 commercially available composites was determined.MethodsThe ERα-CALUX bioassay was used to determine both agonistic and antagonistic estrogenic activities of the pure compounds (BPA, BisDMA, BisGMA, BisEMA(3), BisEMA(6), BisEMA(10), TEGDMA, TCD-DI-HEA, BADGE, UDMA, HMBP, DMPA, CQ) and the leachates of cured composite disks. The leachates of 4 commercially available composites (Solitaire 2, Ceram.x Spectra ST, G-ænial Posterior and Filtek Supreme XTE) in water and 0.1 M NaOH (pH = 13, ‘worst-case scenario’) were tested for estrogenic activity (pooled leachates from 10 cured composite disks).ResultsAgonistic estrogenic activity was found for the monomer BisDMA, the photostabilizer HMBP and photoinitiator DMPA. All leachates from the 4 tested composites showed significant agonistic estrogenic activity higher than the DMSO control, and the highest activity (potency and efficacy) was found for Solitaire 2, followed by Ceram.x Spectra ST. Furthermore, antagonistic estrogenic activity was found in the leachates from G-ænial Posterior.SignificanceThese results show that significant estrogenic activity was found in all leachates of the cured composite disks, and that this estrogenicity is most likely due to a mixture effect of multiple estrogenic compounds (including BPA, HMBP and DMPA). This indicates that further research into the endocrine activity of all the compounds that are present in these composites (even at low quantities) and their possible mixture effect is warranted to guarantee their safe use.  相似文献   
2.
目的以延长活化部分凝血活酶时间(APTT)为指标,建立定量测定川芎抗凝血作用的方法,评价川芎及其中成药的质量。方法川芎先后用乙醇和水定量提取,以总提取物为供试品,体外测定延长APTT值。家兔心脏取血,制备血浆,加入APTT试剂后,测定凝结时间。以APTT延长率为抗凝血活性的评价指标,用阿魏酸钠标定川芎的延长APTT活性。根据量反应平行线法(2.2)计算川芎的抗凝血活性。并测定了9份川芎药材、饮片及中成药的抗凝血活性。结果阿魏酸钠和川芎总提取物均具有显著的抗凝血活性,且可靠性检验结果成立。阿魏酸钠的给药质量浓度(1~5 mg/m L)与其APTT延长率呈良好的线性关系(r=0.995 5)。供试品重复测定抗凝血活性的RSD为9.34%(n=6),可信限率为15.98%(n=6)。不同川芎样品的抗凝血活性不同,5份川芎药材的抗凝血效价分别为5.431~7.620 U/g,川芎饮片及川芎酒炙饮片分别为5.910、3.017 U/g,通脉颗粒和血府逐瘀丸分别为14.516、29.035 U/g。结论建立的方法能准确测定川芎药材、饮片及其中成药的抗凝血活性并评价其质量。  相似文献   
3.
4.
目的:建立胰岛素生物测定的快速检测方法。方法:血糖试纸上的葡萄糖脱氢酶将血液中的葡萄糖转化为葡萄糖酸内脂。这种作用会产生直流电,血糖仪以此判读血糖值。使用血糖仪快速测定小鼠血糖。结果:血糖仪能够快速测定小鼠血糖值,与全自动生化分析仪测定结果高度相关,效价偏差率<5%,结果无显著性差异(P>0.05)。结论:经方法学验证,本法可用于胰岛素生物活性的快速测定。  相似文献   
5.
Hemapolin (2α,3α‐epithio‐17α‐methyl‐5α‐androstan‐17β‐ol) is a designer steroid that is an ingredient in several “dietary” and “nutritional” supplements available online. As an unusual chemical modification to the steroid A‐ring could allow this compound to pass through antidoping screens undetected, the metabolism of hemapolin was investigated by an in vivo equine drug administration study coupled with GC‐MS analysis. Following administration of synthetically prepared hemapolin to a thoroughbred horse, madol (17α‐methyl‐5α‐androst‐2‐en‐17β‐ol), reduced and dihydroxylated madol (17α‐methyl‐5α‐androstane‐2β,3α,17β‐triol), and the isomeric enone metabolites 17β‐hydroxy‐17α‐methyl‐5α‐androst‐3‐en‐2‐one and 17β‐hydroxy‐17α‐methyl‐5α‐androst‐2‐en‐4‐one, were detected and confirmed in equine urine extracts by comparison with a library of synthetically derived reference materials. A number of additional madol derivatives derived from hydroxylation, dihydroxylation, and trihydroxylation were also detected but not fully identified by this approach. A yeast cell‐based androgen receptor bioassay of available reference materials showed that hemapolin and many of the metabolites identified by this study were potent activators of the equine androgen receptor. This study reveals the metabolites resulting from the equine administration of the androgen hemapolin that can be incorporated into routine GC‐MS antidoping screening and confirmation protocols to detect the illicit use of this agent in equine sports.  相似文献   
6.
通过查阅中、美、英、日四国药典中胰岛素生物测定方法的相关内容,对其历年来的生物活性测定方法进行分析与对比,结果各国药典中胰岛素的生物测定方法还存在差异,胰岛素生物测定方法的发展方向与改进空间应参考国外药典统一为HPLC法。  相似文献   
7.

Objectives

To evaluate the ovicidal and oviposition deterrent activities of five medicinal plant extracts namely Aegle marmelos (Linn.), Limonia acidissima (Linn.), Sphaeranthus indicus (Linn.), Sphaeranthus amaranthoides (burm.f), and Chromolaena odorata (Linn.) against Culex quinquefasciatus and Aedes aegypti mosquitoes. Three solvents, namely hexane, ethyl acetate, and methanol, were used for the preparation of extracts from each plant.

Methods

Four different concentrations—62.5 parts per million (ppm), 125 ppm, 250 ppm, and 500 ppm—were prepared using acetone and tested for ovicidal and oviposition deterrent activities. One-way analysis of variance (ANOVA) was used to determine the significance of the treatments and means were separated by Tukey''s test of comparison.

Results

Among the different extracts of the five plants screened, the hexane extract of L. acidissima recorded the highest ovicidal activity of 79.2% and 60% at 500 ppm concentration against the eggs of Cx. quinquefasciatus and Ae. aegypti, respectively. Similarly, the same hexane extract of L. acidissima showed 100% oviposition deterrent activity at all the tested concentrations against Cx. quinquefasciatus and Ae. aegypti adult females.

Conclusion

It is concluded that the hexane extract of L. acidissima could be used in an integrated mosquito management program.  相似文献   
8.
ObjectiveTo evaluate the toxicity of the ethanol and hexane extracts of the different parts of Persea americana Mill. (P. americana) toward third and fourth instars larvae of Aedes aegypti (Ae. aegypti) and to characterize the ethanol extract by qualitative phytochemical analysis.MethodsThe seeds, peels and pulp of P. americana were processed for crude extraction using 95% ethanol and n-hexane. Crude extracts were bio-assayed for larvicidal activity against Ae. aegypti following the World Health Organization standard bioassay method. The mortality was observed at 24 h and 48 h after treatment and data were subjected to probit analysis to determine lethal concentrations (LC50 and LC90). The ethanol extract was characterized by phytochemical analysis.ResultsBoth the hexane and ethanol extracts from the different parts of P. americana exhibited evidence of larvicidal toxicity. The hexane extract from the seeds exhibited the highest toxicity with LC50 and LC90 values of 9.82 mg/L and 22.19 mg/L, respectively, while the ethanol seed extract exhibited LC50 of 16.48 mg/L and LC90 45.77 mg/L, respectively. This was closely followed by the ethanol extract of the peels with an LC50 of 10.35 mg/L and LC90 of 26.29 mg/L. The pulp extracted with ethanol also yielded great larvicidal toxicity with LC50 of 21.32 mg/L and LC90 of 59.45 mg/L. Results of the phytochemical analysis of the ethanol seed extract indicated presence of alkaloids, tannins, saponins, unsaturated steroids and triterpenoids, flavonoids (leucoanthocyanins), fats and oils.ConclusionsBoth the hexane and ethanol extracts of P. americana showed promising potential as an alternative source of a more sustainable, non-toxic and environmentally friendly solution for the control of dengue vector, Ae. aegypti.  相似文献   
9.
当归为常用的补血药,以阿魏酸等已知化学成分为指标难以有效评价其质量.为此,根据生物检定的原理,建立了定量测定当归药材补血活性的生物检测方法.当归药材依次用乙醇和水提取,以合并后的总提物为供试品进行小鼠补血活性试验;用环磷酰胺和盐酸苯肼联合建立小鼠血虚模型;以红细胞数为补血活性的评价指标,用环孢菌素A标定当归的补血活性.再根据量反应平行线(3 ·3')法计算供试品的补血活性.结果表明,环孢菌素A和当归总提物补血活性的可靠性检验结果成立;与模型组相比,当归总提取物具有显著的补血活性(P<0.05).环孢菌素A在给药剂量0.035 ~0.56 g· kg-1与红细胞数增加值呈良好的线性关系(r=0.998 4,n=5).供试品补血活性重复测定的RSD为6.15%(n=6),可信限率为26.68% (n=6).5份从甘肃、四川、云南收集的当归药材样品的性状特征不同,其补血活性也不同(21.95 ~44.16 U·g-1).表明建立的方法可准确测定当归药材的补血活性,评价其质量.  相似文献   
10.
Therapeutic drug monitoring (TDM) of antifungal triazole was recommended, except for isavuconazole (ISA) whose target trough concentrations (Cmin) need to be specified. Concerning posaconazole (POS), tablet formulation results in higher exposure but no upper Cmin threshold has been yet proposed. We aimed to investigate the pharmacokinetic–pharmacodynamic relationship of POS and ISA, using a bioassay approach as surrogate marker of antifungal activity, in order to refine the therapeutic Cmin of both antifungals. A bioassay using a cellulose disk diffusion method was performed to determine the growth inhibition zone (GIZ) of POS and ISA on Aspergillus fumigatus and Candida parapsilosis (ISA only). GIZs of plasma from patients undergoing TDM for POS (n = 136) or ISA (n = 40) were determined. GIZs of plasma patients and antifungal Cmin were highly correlated for ISA (A. fumigatus: ρ = 0.942, < 0.0001; C. parapsilosis: ρ = 0.949, < 0.0001) and POS (ρ = 0.922, P < 0.0001), and these relationships were represented with a Michaelis–Menten model. Based on this modeling, the recommended thresholds of 0.7, 1, and 1.25 mg/L for the POS Cmin corresponded to 50.1, 55.2, and 59.1% of the maximal GIZ, respectively. We propose an upper threshold of 4.8 mg/L for the POS Cmin and a lower threshold of 2.0 mg/L for the Cmin of ISA, as they respectively corresponded to concentrations leading to 90% and 50% of the maximal GIZ on A. fumigatus. The determination of antifungal activity using this bioassay allowed refining target Cmin of POS and ISA, especially the upper threshold of POS (4.8 mg/L) and the lower threshold of ISA (2.0 mg/L).  相似文献   
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