曲克芦丁脑蛋白水解物联合醒脑静治疗脑卒中的疗效

目的探讨曲克芦丁脑蛋白水解物联合醒脑静注射液治疗急性缺血性脑卒中的临床疗效。方法选取医院2016年6月—2018年10月收治的急性缺血性脑卒中患者96例,治疗方案不同分为观察组(n=48)和对照组(n=48),对照组采用曲克芦丁脑蛋白水解物治疗,观察组于对照组基础上采用醒脑静注射液治疗,疗程结束后,观察分析2组治疗效果,治疗前后神经缺损(NIHSS评分)、生活质量(SS-QOL评分)。结果观察组总有效率91.67%较对照组75.00%高(P<0.05),治疗后观察组SS-QOL评分较对照组高(P<0.05),观察组NIHSS评分较对照组低(P<0.05)。结论曲克芦丁脑蛋白水解物联合醒脑静注射液应用于急性缺血性脑卒中患者治疗中,疗效肯定,并可显著减轻神经缺损,提高生活质量。     

丹参干燥前后游离型和结合型酚酸的比较研究

丹参干燥前后,新鲜和干燥丹参中酚酸成分含量有显著性差异,即在干燥过程中随脱水增加,丹参酚酸含量显著增加。为探究丹参干燥前后游离型和结合型酚酸含量的差异及转化,该实验对丹参酚酸水解方法、水解产物、水解规律等进行研究,采用UPLC测定丹参结合型酚酸4种主要水解产物丹参素、咖啡酸二聚体(SMND-309)、咖啡酸、甘西鼠尾草酸甲(原紫草酸)以及丹参中3种主要游离酚酸成分(迷迭香酸、紫草酸和丹酚酸B)的含量。结果显示,丹参酚酸的碱水解效果显著优于酸水解,优选的碱水解条件为用含有1%抗坏血酸的2 mol·L-1氢氧化钠溶液于70℃水解4 h;游离酚酸和结合酚酸的水解产物相同;新鲜丹参中游离酚酸含量较低,结合酚酸含量较高,而干燥丹参却相反。提示丹参生长过程中已积累储存了大量的结合型酚酸,主要以酯键与细胞壁多糖结合形成了不溶性酚酸,常规方法不易检出,在干燥脱水过程中,结合型酚酸或在相关酶的作用下转化生成大量的游离酚酸。     

Improving the Acid and Base Resistance of Polyurethane Using Carbon Nanotubes

This paper demonstrates that carbon nanotubes (CNTs) can be used as an effective filler for inhibiting the hydrolysis of polyurethane (PU) under acidic and basic conditions. Although it has been reported that CNTs can quench the radicals on its surface, for the first time, it is confirmed that CNTs undergo reactions that have an inhibiting effect on ion‐mediated hydrolysis. Attenuated total reflectance–infrared spectroscopy measurements on PU and PU–CNT samples reveal that CNTs inhibit the hydrolysis of PU in both acid and alkaline environments. Via quantum chemical calculations, it is shown that CNTs can trap H⁺ ions and OH^? ions on their surface. It is also shown that CNTs can trap multiple ions, even though electrical repulsion is to be expected. The results reveal that CNTs can also function as a hydrolysis inhibitor in addition to their known functions as an antioxidant.     

Carboxylesterase catalyzed 18O-labeling of carboxylic acid and its potential application in LC-MS/MS based quantification of drug metabolites

LC-MS quantification of drug metabolites is sometimes impeded by the availability of internal standards that often requires customized synthesis and/or extensive purification. Although isotopically labeled internal standards are considered ideal for LC-MS/MS based quantification, de novo synthesis using costly isotope-enriched starting materials makes it impractical for early stage of drug discovery. Therefore, quick access to these isotope-enriched compounds without chemical derivatization and purification will greatly facilitate LC-MS/MS based quantification. Herein, we report a novel ¹⁸O-labeling technique using metabolizing enzyme carboxylesterase (CES) and its potential application in metabolites quantification study. Substrates of CES typically undergo a two-step oxygen exchange with H₂¹⁸O in the presence of the enzyme, generating singly- and doubly-¹⁸O-labeled carboxylic acids; however, unexpected hydrolytic behavior was observed for three of the test compounds – indomethacin, piperacillin and clopidogrel. These unusual observations led to the discovery of several novel hydrolytic mechanisms. Finally, when used as internal standard for LC-MS/MS based quantification, these in situ labeled compounds generated accurate quantitation comparable to the conventional standard curve method. The preliminary results suggest that this method has potential to eliminate laborious chemical synthesis of isotope-labeled internal standards for carboxylic acid-containing compounds, and can be developed to facilitate quantitative analysis in early-stage drug discovery.     

Screening and confirmation methods for the qualitative identification of nine phytocannabinoids in urine by LC-MS/MS

Qualitative liquid chromatography tandem mass spectrometry (LC-MS/MS) methods were developed and validated to screen and confirm the presence of nine phytocannabinoids in urine. The nine phytocannabinoids targeted in the methods included Δ⁹-tetrahydrocannabinol (THC), 11-hydroxy-THC, 11-nor-9-carboxy-THC, cannabidiol, 7-carboxy cannabidiol, cannabinol, cannabigerol, Δ⁹-tetrahydrocannabivarin (THCV), and 11-nor-9-carboxy-THCV. The methods presented use a rapid, single-step enzymatic hydrolysis followed by solid-phase extraction and LC-MS/MS analysis. Limits of detection were established at 1 µg/L for non-carboxylated analytes and 5 µg/L for carboxylated analytes. The screening and confirmation methods were validated and implemented in the analysis of authentic case samples. These methods can assist forensic, medicolegal, or medical compliance investigations as the presence of phytocannabinoids, or lack there-of, may be used to help differentiate cannabis (hemp, marijuana) use from synthetic THC (dronabinol) exposure.     

Investigation of the presence of carbapenemases in carbapenem-resistant Klebsiella pneumoniae strains by MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) and comparison with real-time PCR method

PurposeWe aimed to develop a new procedure for rapid detection of the carbapenemase activity using MALDI-TOF MS, and to determine the sensitivity and specificity of the method. Also, we aimed to determine the distribution of carbapenemase genes among the K.pneumoniae strains isolated in our hospital using real-time PCR.MethodBetween January 2017–February 2019; K. pneumoniae strains(n = 74) isolated from blood culture samples were included. Klebsiella pneumoniae NCTC 13438 was used as a positive control and Escherichia coli ATCC 25922 as a negative control. First, Imipenem, meropenem, and ertapenem MIC values of strains were determined. Then bla_KPC, bla_OXA-48, and/or bla_NDM genes were investigated with PCR. Carbapenemase activity was investigated in strains with the newly developed method using MALDI-TOF MS. The performance of the new method was evaluated for both the second and fourth hours of the incubation period.ResultsWhile 65 strains were found resistant to tested carbapenems, nine of them were susceptible. Of the 65 resistant strains, 57 had bla_OXA-48, 15 had bla_NDM, and four had bla_KPC genes. Bla_OXA-48 and bla_NDM genes were detected together in 11 strains. Bla_OXA-48, bla_NDM, and bla_KPC genes were not detected in any of the susceptible strains. The sensitivity and specificity of MALDI-TOF MS at the second hour were 83.1% and 100%, respectively. At the fourth hour, the sensitivity and specificity of MALDI-TOF MS were 100%. No false-positive results were observed.ConclusionThe sensitivity of the method at the fourth hour was better than the second hour. The false-negative results observed in the second hour disappeared when the incubation period was extended to 4 h. MALDI-TOF MS which is still under development is a fast, cost-effective, promising method for the detection of carbapenemase activity.     

Microbial factors and gingival crevicular fluid aspartate aminotransferase levels

Abstract. The aim of this cross-sectional study was to investigate the clinical application of chairside tests for gingival crevicular fluid (GCF) aspartale amino-transferase (AST) levels and plaque BANA hydrolysis activity with the presence of the periodontal pathogens Porphyromonas gingivalis and Actinohacillus action-mycetemcomitans. The study comprised 100 periodontitis sites (pocket depths≥4 mm. GI = 3) from 10 patients with chronic adult periodontitis and 100 control sites (pocket depths <4 mm. GI<3) from 10 periodontally healthy patients comprising 55 healthy sites (pocket depths <4 mm. GI=0) and 45 gingivitis sites (pocket depths <4 mm, GI=1 or 2). The values for both BANA hydrolysis and AST levels were significantly higher in samples from periodontitis compared with gingivitis and healthy sites (p<0.001), A. actinomycetemcomitans was identified in 45% and P. gingivalis in 17% of periodontitis sites but neither pathogen was recovered from control sites and there was no significant correlation with (he clinical parameters measured. There was no significant relationship between the presence of P. gingivalis and/or A. actinmycetemcomitans with BANA hydrolysis or AST levels. A significant correlation (p=0.0017) was observed between BANA hydrolysis and pocket depth and between AST hydrolysis and the GI (p=0.01). This study failed to demonstrate a positive association between chairside analysis of GCF metabolites for AST levels and/or BANA hydrolysis with P. gingivalis and A. actinomycetemcomitans. However, the GCF metabolites had a significant correlation with periodontally diseased sites in patients with chronic adult periodontitis and may help confirm clinical observations.     

Combined enzymatic hydrolysis and herbal extracts fortification to boost in vitro antioxidant activity of edible bird’s nest solution

Objective Edible bird’s nest (EBN) is a popular traditional tonic food in Chinese population for centuries. Malaysia is one of the main EBN suppliers in the world. This study aims to explore the best strategy to boost the antioxidant potential of EBN solution. Methods In this study, the raw EBN (4%, mass to volume ratio) was initially enzymatic hydrolyzed using papain enzyme to produce EBN hydrolysate (EBNH), then spray-dried into powdered form. Next, 4% (mass to volume ratio) of EBNH powder was dissolved in ginger extract (GE), mulberry leaf extract (MLE) and cinnamon twig extract (CTE) to detect the changes of antioxidant activities, respectively. Results Results obtained suggest that enzymatic hydrolysis significantly reduced the viscosity of 4% EBN solution from (68.12 ± 0.69) mPa.s to (7.84 ± 0.31) mPa.s. Besides, the total phenolic content (TPC), total flavonoid content (TFC), total soluble protein, DPPH scavenging activity and ferric reducing antioxidant power (FRAP) were substantially increased following EBN hydrolysis using papain enzyme. In addition, fortification with GE, MLE and CTE had further improved the TPC, TFC, DPPH scavenging activity and FRAP of the EBNH solution. Among the samples, MLE-EBNH solution showed the most superior antioxidant potential at (86.39 ± 1.66)% of DPPH scavenging activity and (19.79 ± 2.96) mmol/L FeSO4 of FRAP. Conclusion This study proved that combined enzymatic hydrolysis and MLE fortification is the best strategy to produce EBN product with prominent in vitro antioxidant potential. This preliminary study provides new insight into the compatibility of EBN with different herbal extracts for future health food production.     

低密度脂蛋白胆固醇的直接测定法

目的　建立直接测定血清低密度脂蛋白胆固醇 (LDL C)的方法。方法　基于选择性水解法的原理 ,通过对多聚体和表面活性剂的筛选和测定条件的优化实验确定了方法。结果　本法反应达终点的时间为 180s ,线性达 11 7mmol/L ,批内CV <1 6 4% ,日间CV <2 6 5 % ,总CV <3 38% ,回收率平均为 99 7%。和日本一化试剂比较 :Y =0 94X 0 0 32 ,r =0 975 ,n =5 2。本法的特异性好 ,加入LDL C达 3 9mmol/L ,VLDL Trig达 19 5mmol/L ,抗坏血酸 <2 84mmol/L、血红蛋白<5g/L和胆红素 <340 μmol/L时无显著干扰。 结论　本法的总误差 <7 40 % ,达到NCEP提出的 <12 %的分析目标 ,标本无需预处理 ,适合全自动分析     

超声波协同复合酶提取菟丝子总黄酮工艺优化

目的:将酶解法和超声波法联用,通过工艺优化提高菟丝子总黄酮的含量。方法:实验采用紫外分光光度法测定总黄酮提取率,选取酶解pH、酶解温度和超声时间3个指标为影响因素,菟丝子总黄酮提取率为响应值,Design-Expert 8.0统计分析软件的响应面分析法安排试验后获得最适合工艺参数。结果:最适合的工艺参数是PH为4.0,酶解温度为52.6℃,超声时间为20.3 min,在此条件下得到的总黄酮质量分数为23.39 mg·g~(-1)。结论:此工艺操作简单、稳定性好、总黄酮提取率高,可为菟丝子总黄酮的相关工业生产提供技术支持。