脉冲进样火焰原子吸收光谱法测定血清、脑和骨中的铁

采用脉冲微量进样火焰原子吸收光谱法测定血清、脑组织及骨中铁含量。血清样品经稀释后直接测定，脑组织及骨样品采用HNO3－HClO4湿法消化。实验探讨了进样体积、提升速度等影响因素，方法的相对标准偏差为1．1％－3．3％，平均回收率为99．0％－100．1％。     

Western blot detection of brain material in heated meat products using myelin basic protein and neuron-specific enolase as biomarkers

An assay based on Western blotting and detection of central nervous system (CNS)-specific antigens was developed to detect brain tissue in processed (heated) meat products. Bands of antigen-bound primary antibodies were visualised through secondary anti-antibodies labelled with peroxidase, which generated chemiluminescence documented by a photographic film. Ponceau-S staining before antibody incubation and molecular mass information on detected antigens after immunoreactions added information supporting correct identification of brain tissue in the meat products. In this approach B50/growth-associated protein (B50), glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), neurofilament (NF), neuron-specific enolase (NSE) and synaptophysin (Syn) proteins were detected in raw luncheon meat and a liver product enriched with brain tissue at a level of 5% (m/m). Only MBP and NSE were considered suitable biomarkers for detection of 1% (m/m) brain tissue in meat products pasteurised at 70 °C or sterilised at 115 °C. The use of an anti-monkey MBP instead of anti-human MBP enabled speciation of the CNS material whether from bovine and ovine brains or from porcine brain tissue. This immunoblot assay potentiates the analysis of approximately 70 samples within 8 h, including sample preparation and the simultaneous probing of NSE and MBP target antigens.     

傅里叶变换红外光谱法检测脑肿瘤

应用傅里叶变换红外光谱法检测了28例液氮冻存的离体脑肿瘤样本及其残留物(将脑肿瘤样本从ATR的ZnSe晶片上取下,样本在ZnSe晶片上沾染后留下的物质).结果发现,神经鞘瘤和神经上皮组织肿瘤(如星形细胞瘤等)的主要特征吸收峰存在明显差异,因此可从各个特征吸收峰的峰位、峰形及不同谱峰强度比的变化来初步鉴别脑肿瘤的性质,脑肿瘤组织样品残留物的红外光谱也可反映不同性质脑肿瘤的差异.与脂类糖蛋白以及核酸相关的谱带变化分析表明,通过特征峰强比(I1460cm-1/I1400cm-1,I1160cm-1/I1120cm-1和I1160cm-1/I1080cm-1)来鉴别肿瘤的性质与病理诊断结果的符合率超过85%.     

A fast and sensitive enzyme immunoassay for brain natriuretic peptide based on micro-magnetic probes strategy

In this paper, a simple, rapid and low-cost method for the high-sensitivity detection of brain natriuretic peptide (BNP) was developed, which adopted three amplification steps: (a) biotin-streptavidin amplification; (b) micro-magnetic probe amplification; (c) HRP (horseradish peroxidase) signal amplification. In the present strategy, the streptavidin-coated micro-magnetic particles (MMPs) were first conjugated with biotin-labeled capture antibody via the biotin-streptavidin interaction, which formed bio-functional micro-magnetic probes. Then, the analyte (antigen) is sandwiched by HRP-labeled antibody and capture antibody bound to MMPs. Finally, the HRP at the surface of sandwich structures catalytically oxidized the substrate and generated optical signals that reflected the amount of the target BNP. The influence of some important parameters such as the size of magnetic particles, the working concentration of HRP-labeled BNP antibody, the stability of magnetic probes, and the assay medium of serum BNP, etc. on the detection ability of present method was investigated in details. It is found that the detection limit of the proposed method could reach 10 pg/mL for BNP, which is much lower than that of sandwich-type ELISA. Furthermore, this detection time for the proposed method just takes about 30 min (two reaction steps and one wash step), which is faster than that of conventional sandwich-type ELISA (taking about 4 h, three reaction steps and three wash steps). Inspired by these advantages, it is expected that this method can probably be applicable to the detection of other hormones and tumor markers that are present in only low concentrations within the human body.     

Synthesis and investigation of anti-inflammatory and anticonvulsant activities of novel coumarin-diacylated hydrazide derivatives

A number of novel coumarin derivatives synthesized by the reaction of 3-carbonyl chloride coumarin with some substituted aryl acid hydrazides to investigate their anti-inflammatory and anticonvulsant activities. Carrageenan (0.1 ml of 1%, w/v) was injected subplantarly in the right paw of rats to induce an acute model of inflammation. Anti-inflammatory efficacy was evaluated for 5 hours at 3 different dosages 5, 10, 25 mg/kg. After that, the changes in the level of paw edema volumes and percentage inhibition of all groups were observed and the most effective coumarin derivative was found as N'-(2-hyroxybenzoyl)-2-oxo-2H-chromene-3-carbohydrazide. In addition, N’-(2-oxo-2H-chromene-3-carbonyl)nicotinohydrazide, (E)-N’-(3-(4-hydroxyphenyl)acryloyl)-2-oxo-2H-chromene-3-carbohydrazide, and N’-(5-amino-2-hydroxybenzoyl)-2-oxo-2H-chromone-3-carbohydrazide showed their anti-inflammatory effects in a dose-dependent manner. On the other hand, pentylenetetrazole (PTZ, 80 mg/kg, i.p.)-induced seizure model was used to investigate the anticonvulsant activities of six newly synthesized coumarin derivatives in mice. Hybrid compound of salicylic acid hydrazide and 3-carbonyl chloride coumarin (8d) was found the most promising anticonvulsant agent among all treatment groups according to the onset of seizure and survival rate. Moreover, (E)-N'-cinnamoyl-2-oxo-2H-chromene-3-carbohyrazide (8b) and (E)-N'-(3-(4-hyroxyphenyl)acryloyl)-2-oxo-2H-chromene-3-carbohydrazide (8c) has potential anticonvulsant efficiency in low doses (30 mg/kg). The anticonvulsant effect of these coumarin derivatives may be through enhanced GABA-mediated inhibition in the brain.     

An integrated experimental and analytical approach to the chemical state imaging of iron in brain gliomas using X-ray absorption near edge structure spectroscopy

X-ray absorption near-edge structure spectroscopy is used for human neoplastic tissues in order to investigate distributions and chemical states of iron. The specimens used in this study were obtained intraoperatively from brain gliomas of different types and various grades of malignancy and from a control subject. An integrated experimental and analytical approach toward topographic and quantitative analysis in thin freeze-dried cryo-sections is presented. The full XANES spectra at the Fe absorption K edge show the presence of both chemical forms of Fe in the analyzed points of the tissues. The main goal of the work is the chemical state imaging of Fe in tissue areas. Topographic analysis of Fe speciation in the tissues investigated with the use of the XANES technique indicates the presence of microstructures where Fe²⁺ is dominant as well as those with a high abundance of the oxidized form of Fe. The quantitative analysis shows that for all cases the content of the oxidized form of Fe is significantly higher in comparison with Fe²⁺. The highest level of Fe³⁺ is found in the control sample, and the lowest one for the glioma of the highest grade of malignancy. The content of either Fe²⁺ or Fe³⁺ is increased in low grade gliomas in comparison to high-grade malignant tumors.     

Fish oil preparation inhibits leukocyte recruitment and bands that characterize inflamed tissue in a model of phenol-induced skin inflammation: percutaneous penetration of a topically applied preparation demonstrated by photoacoustic spectroscopy

Abstract

Fish oil (FO) is a natural source of omega-3 fatty acids, with well-established beneficial effects in inflammatory diseases when FO is orally administered. This study investigated the effects of a topically applied FO preparation (FOP) on phenol-induced ear edema and evaluated the percutaneous penetration of FOP in ear tissue. After applying phenol, groups of mice received FOP on the ear. After 1?h, ear tissue was collected to determine the percent inhibition of edema, myeloperoxidase activity, and to perform photoacoustic spectroscopy (PAS). Treatment with FOP did not reduce edema, but reduced myeloperoxidase activity. The FOP decreased the area of bands that characterize inflamed tissue and penetrated into the tissue. These results indicated an inhibitory effect of FOP on leukocyte recruitment in phenol-induced ear edema. These data support the applicability of PAS as a non-destructive method for evaluating the inflammatory response, percutaneous penetration and antiinflammatory activity of compounds.     

Development and validation of an RP-HPLC method for the estimation of adenosine and related purines in brain tissues of rats

A new, rapid and sensitive RP-HPLC method with UV spectrophotometric detection was developed and validated for the concomitant estimation of adenosine and related purines in rat brain tissue preparations. The HPLC system consisted of C-18 column with UV-photodiode-array detection ranging from 210 to 400 nm, facilitating the online confirmation of peak purity. The column temperature was maintained at 30 degrees C and the injection volume was 20 muL. Elution with an isocratic mobile phase consisting of water/methanol/acetonitrile (88:5:7 by volume) at a flow rate of 0.8 mL/min yielded sharp, utmost-resolved peaks of adenosine (Ade), inosine (Ino), hypoxanthine (Hypoxan) and adenine (Adn) within 10 min. The method was validated with respect to the linearity, accuracy, precision, sensitivity, selectivity and stability. The method was also employed to estimate the naturally occurring purines in discrete regions of rat brain. A new protocol developed for tissue preparation utilizing H(2)SO(4) and Tris buffer gave well-resolved peaks and high component recoveries (>96%) which eliminated the need of an internal standard. The results show that the method for the determination of Ade, Ino, Hypoxan and Adn by RP-HPLC described here has good linearity, accuracy, precision, sensitivity, selectivity and is simple and rapid to perform.     

The rapid and automatic combination of proton MRSI data using multi-channel coils without water suppression

The use of multi-channel coils can efficiently increase the signal-to-noise ratio (SNR) of magnetic resonance spectroscopy data if the signals from multiple channels are optimally combined. Combining multi-channel signals requires proper alignment of the phases of the signals from each of the elements of the coil and then accurately weighting the summation of those signals. We present a procedure for acquiring proton magnetic resonance spectroscopic imaging (MRSI) data using an eight-channel coil without water suppression and a rapid and robust method that uses unsuppressed water signal as a reference both for aligning the phases and for weighting the summation of signals that originate in the multiple coil elements. We use both computer simulation and in vivo proton MRSI data to demonstrate the advantages of our method for optimizing the SNR of the combined signal compared with the SNRs of signals that were acquired either using a standard volume head coil or using an eight-channel coil with a metabolite signal as the reference for combination.     

大鼠脑组织中轻稀土元素含量相关性研究

研究了轻稀土元素La、Ce、Pr、Nd、Sm、Eu、Gd在大鼠脑组织中的吸收规律和蓄积特点.将雄性SD大鼠随机分为空白、对照、低、中、高及排毒组,每组10只,4周后处死,取脑组织.排毒组停止灌胃后继续饲养4周后处死取脑组织.用ICP-MS测定脑组织中上述稀土元素含量并做统计学分析.结果表明低、中、高剂量组大鼠脑组织中轻稀土元素含量逐渐增高,排毒组介于中、高剂量组之间;脑组织中轻稀土元素的含量远低于其他脏器;La、Ce、Pr在脑中分布符合奥多-哈尔金斯规则,Nd元素呈负偏离;多数轻稀土元素在脑和毛发中含量相关系数较高.稀土元素在脑组织中蓄积有量效关系,且蓄积具有可逆性;血-脑屏障对稀土元素的通透有一定阻碍作用;稀土元素在脑组织中的蓄积率不受摄入量的影响;毛发比全血更适合作为脑组织轻稀土元素含量的生物标志物.