冬令膏方防治小儿哮喘缓解期研究进展

文章对近年来有关冬令膏方防治小儿哮喘缓解期的临床及实验研究进展作一综述。众医家从肺脾肾三脏虚损着手,确立健脾益肺、温补肾阳、温肾填精、健脾温肾等治法,灵活运用冬令膏方防治小儿哮喘缓解期,取得良好疗效。冬令膏方防治哮喘缓解期的疗效机制研究也正在进行。同时认为冬令膏方防治小儿哮喘缓解期尚存在一些问题,如膏方制作程序缺乏统一标准,制作成本高,临床研究有待规范深入,疗效评价体系不完善等,并针对前述问题提出个人见解。     

喹烯酮诱导HepG2细胞DNA复制相关基因表达水平的变化

目的：喹烯酮能诱导HepG2细胞S期阻滞,引起DNA和染色体损伤。本研究旨在对喹烯酮致HepG2细胞S期阻滞机制进行筛选和分析。方法：本研究对喹烯酮染毒后HepG2细胞和未染毒HepG2细胞进行了Agilent全基因组的表达谱芯片检测,应用Genespring软件对差异表达的基因进行相关通路分析,并使用荧光定量PCR技术对部分DNA复制相关表达差异基因进行验证。结果：在芯片点样的41000个寡聚核苷酸片段中,喹烯酮染毒HepG2后,差异表达基因共1750个,其中表达上调的基因共446个,表达下调的基因共1304个。差异表达基因通路分析结果表明,与细胞周期、MAPK通路、DNA复制及DNA修复等通路相关的基因表达差异显著。经荧光定量PCR验证,DNA复制相关基因表达变化趋势与芯片检测结果相一致。结论：DNA复制相关基因的下降导致S期DNA复制的不完全性以及DNA损伤后引起的DNA修复,使得HepG2细胞在喹烯酮染毒后引起S期阻滞。基因表达谱芯片检测分析的结果为喹烯酮致HepG2细胞S期阻滞机制的深入研究奠定了基础。     

基底细胞癌皮损中不同标记朗格汉斯细胞的研究

 目的　研究基底细胞癌（BCC）皮损中不同标记朗格汉斯细胞（LC）数量、形态以及分布等特点,为探讨其在皮肤肿瘤局部细胞免疫中可能的作用提供实验依据。方法　对30例BCC患者皮损组织和15例正常皮肤组织中浸润的LC进行CD1a、S-100蛋白和HLA-DR免疫组织化学染色,以计算机图像分析系统对阳性细胞进行定量研究。结果　BCC皮损中CD+1a LC呈局灶性分布于癌巢;与对照组相比,CD+1a LC细胞突起明显减少、缩短甚至消失;阳性细胞计数和免疫组织化学染色强度灰度值结果均显示：皮损中CD+1a LC数量较对照组显著下降,差异有统计学意义（P＜0.05）。BCC皮损中S-100（+）LC弥漫性分布于癌巢和癌旁;与对照组相比,S-100（+）LC细胞染色增强,细胞突起明显增多、增长;阳性细胞计数和免疫组织化学染色强度灰度值结果均显示：皮损中S-100（+）LC的数量显著增加,差异有统计学意义（P＜0.05）。BCC皮损中HLA-DR（+）LC主要集中于癌旁;细胞形态与对照组相似;阳性细胞计数和免疫组织化学染色强度灰度值结果均显示：皮损中HLA-DR（+）LC的数量略增加,但差异无统计学意义（P＞0.05）。结论　与正常皮肤组织相比,BCC皮损中不同标记的LC数量、形态及分布趋势均有差异,提示皮损中可能存在特殊的局部细胞免疫状态,可能是BCC低转移性和较好预后的重要原因之一。     

Salvage treatment for children with refractory first or second relapse of acute myeloid leukaemia with gemtuzumab ozogamicin: results of a phase II study

The prognosis of children with relapsed/refractory acute myeloid leukaemia (AML) is poor, and new therapies are needed. Gemtuzumab ozogamicin (GO) is an anti‐CD33 antibody linked to the antitumor antibiotic calicheamicin. We conducted an investigator‐initiated phase II study with GO to assess its efficacy and safety, administering two dosages of 7·5 mg/m² with a 14 d‐interval. Thirty children who were refractory to re‐induction at first relapse or suffered from second relapse of AML received a total of 64 infusions of GO. The response rate [complete remission (CR) and CR with insufficient platelet recovery] was 37%. Nine patients were subsequently transplanted (median time to transplant, 4 weeks, range 3–21 weeks), and three of these patients are currently in continuous CR with a median follow‐up of >3 years, and can considered to be cured. This resulted in a statistically significant survival advantage for children who responded to GO versus those who did not [27% (standard error 13%) vs. 0%, respectively, P = 0·001]. All other children died, mainly from progressive disease. The treatment was generally well tolerated by most patients. The frequency of transient transaminatis was low. All but one patient received defibrotide prophylaxis during the transplant procedure, and no cases of veno‐occlusive disease were noted. This study showed a favourable safety/efficacy profile of single‐agent GO in children with refractory first or second relapse of AML.     

Contribution of isoprene-derived organosulfates to free tropospheric aerosol mass

Recent laboratory studies have demonstrated that isoprene oxidation products can partition to atmospheric aerosols by reacting with condensed phase sulfuric acid, forming low-volatility organosulfate compounds. We have identified organosulfate compounds in free tropospheric aerosols by single particle mass spectrometry during several airborne field campaigns. One of these organosulfates is identified as the sulfate ester of IEPOX, a second generation oxidation product of isoprene. The patterns of IEPOX sulfate ester in ambient data generally followed the aerosol acidity and NO(x) dependence established by laboratory studies. Detection of the IEPOX sulfate ester was most sensitive using reduced ionization laser power, when it was observed in up to 80% of particles in the tropical free troposphere. Based on laboratory mass calibrations, IEPOX added > 0.4% to tropospheric aerosol mass in the remote tropics and up to 20% in regions downwind of isoprene sources. In the southeastern United States, when acidic aerosol was exposed to fresh isoprene emissions, accumulation of IEPOX increased aerosol mass by up to 3%. The IEPOX sulfate ester is therefore one of the most abundant single organic compounds measured in atmospheric aerosol. Our data show that acidity-dependent IEPOX uptake is a mechanism by which anthropogenic SO(2) and marine dimethyl sulfide emissions generate secondary biogenic aerosol mass throughout the troposphere.     

Palmitoylation regulates raft affinity for the majority of integral raft proteins

The physical basis for protein partitioning into lipid rafts remains an outstanding question in membrane biology that has previously been addressed only through indirect techniques involving differential solubilization by nonionic detergents. We have used giant plasma membrane vesicles, a plasma membrane model system that phase separates to include an ordered phase enriching for raft constituents, to measure the partitioning of the transmembrane linker for activation of T cells (LAT). LAT enrichment in the raft phase was dependent on palmitoylation at two juxtamembrane cysteines and could be enhanced by oligomerization. This palmitoylation requirement was also shown to regulate raft phase association for the majority of integral raft proteins. Because cysteine palmitoylation is the only lipid modification that has been shown to be reversibly regulated, our data suggest a role for palmitoylation as a dynamic raft targeting mechanism for transmembrane proteins.     

单独应用米索前列醇紧急避孕临床效果观察

目的研究女性黄体早期单独应用米索前列醇进行紧急避孕的有效性、安全性和可接受性。方法采用前瞻性临床研究,选择符合接收标准、要求紧急避孕、并愿意参加本课题研究的221例育龄妇女作为研究对象。分米索前列醇组(78例)、米非司酮组(71例)、无避孕组(72例)三组,米索前列醇组空腹顿服米索前列醇200μg×2片,米非司酮组单次口服米非司酮25mg,预约预期下次月经后10d内随访。观察在黄体早期用药后的妊娠率、月经的变化和副作用。结果①米索前列醇组1例妊娠,失败率为1.3%,米非司酮组无妊娠,失败率为0;无避孕组12例妊娠,失败率为16.7%,米索前列醇组、米非司酮组与无避孕组间均有显著性差异。米非司酮组与米索前列醇组之间无显著性差异。②随访时米索前列醇组77例、米非司酮组71例及无避孕组60例月经已经来潮,米索前列醇组及米非司酮组开始出血时间早于无避孕组,经检验有显著性差异(p<0.05),而米索前列醇组与米非司酮组之间无差异(p>0.05);出血持续时间3组间无显著性差异,与正常月经经期基本一致。③应用两种药物均无不良后果,副作用轻,能自行缓解。结论黄体期单独应用米索前列醇紧急避孕也是有效、安全和可行的方法。     

Sample preparation development and matrix effects evaluation for multianalyte determination in urine

The development of a generic analytical method remains difficult when a high number of compounds has to be simultaneously considered. This study proposes an innovative strategy for the development of a solid phase extraction (SPE) procedure before liquid chromatography-mass spectrometry analysis of 34 diuretics and beta-blockers in urine samples. These compounds have been selected since they are often encountered in anti-doping control. The principle is based on the selection of representative analytes during SPE protocol optimization, allowing a drastic reduction of generated data and development time. To select the representative compounds, all substances were classified based on their SPE behavior with a generic method and groups were formed with the help of a chemometric tool, namely hierarchical cluster analysis (HCA). One representative analyte per group was selected and used for subsequent SPE method development. Once the SPE method was developed, compounds were analyzed by LC-MS and matrix effects were evaluated to determine the influence of the matrix on the SPE process and MS signal alteration due to endogenous compounds. As a result, matrix effects evaluation must be performed on all analytes; representative compounds previously selected for SPE development were unable to predict matrix effects.     

Quantification of artemisinin in human plasma using liquid chromatography coupled to tandem mass spectrometry

A liquid chromatographic tandem mass spectroscopy method for the quantification of artemisinin in human heparinised plasma has been developed and validated. The method uses Oasis HLB™ μ-elution solid phase extraction 96-well plates to facilitate a high throughput of 192 samples a day. Artesunate (internal standard) in a plasma–water solution was added to plasma (50 μL) before solid phase extraction. Artemisinin and its internal standard artesunate were analysed by liquid chromatography and MS/MS detection on a Hypersil Gold C18 (100 mm × 2.1 mm, 5 μm) column using a mobile phase containing acetonitrile–ammonium acetate 10 mM pH 3.5 (50:50, v/v) at a flow rate of 0.5 mL/min. The method has been validated according to published FDA guidelines and showed excellent performance. The within-day, between-day and total precisions expressed as R.S.D., were lower than 8% at all tested quality control levels including the upper and lower limit of quantification. The limit of detection was 0.257 ng/mL for artemisinin and the calibration range was 1.03–762 ng/mL using 50 μL plasma. The method was free from matrix effects as demonstrated both graphically and quantitatively.     

A stability-indicating HPLC assay with diode array detection for the determination of a benzylpenicillin prodrug in aqueous solutions

The aim of this study was to develop a stability-indicating HPLC assay for the determination of penethamate (PNT), an ester prodrug of benzylpenicillin (BP), in aqueous solutions. The method was validated by subjecting PNT to forced decomposition under stress conditions of acid, alkali, water hydrolysis and oxidation. A quenching solution was developed to limit degradation to negligible levels before and during the analysis. Both PNT and BP were simultaneously determined and separated in presence of degradation products on a C₁₈ column using a mobile phase consisting of methanol–acetonitrile–acetate buffer. Different degradation products were formed in the stress conditions. The peak purity indexes of PNT and BP obtained by diode array detection were >0.999, confirming the absence of other co-eluting substances. The assay was linear for both analytes in the concentration range 1–100 μg mL⁻¹. The LOD and LOQ of PNT were 0.03 and 0.09 μg mL⁻¹ respectively. Degradation of PNT followed pseudo-first-order kinetics with t_1/2 of 43.6 min at pH 2.01 and 4.2 min at pH 9.31. In addition, the absence of BP in the acidic solutions of PNT emphasises the futility of monitoring BP to assess the stability of PNT. In conclusion, the assay is rapid and stability-indicating with adequate precision and accuracy, and in conjunction with the quenching solution, can be used for stability studies of PNT with simultaneous quantitation of BP. The degradation studies provide useful information for formulation development of PNT.