Analytical Chemistry Insights最新文献_第10页

Role of 99mTc-(V)DMSA in detecting tumor cell proliferation. 99mTc-(V)DMSA在检测肿瘤细胞增殖中的作用。

Analytical Chemistry Insights Pub Date : 2007-12-13

Fatma Al-Saeedi

引用次数: 0

Solid phase extraction for monitoring of occupational exposure to Cr (III). 固相萃取用于监测职业接触Cr（III）。

Analytical Chemistry Insights Pub Date : 2007-12-11

S J Shahtaheri, M Khadem, F Golbabaei, A Rahimi-Froushani

{"title":"Solid phase extraction for monitoring of occupational exposure to Cr (III).","authors":"S J Shahtaheri, M Khadem, F Golbabaei, A Rahimi-Froushani","doi":"","DOIUrl":"","url":null,"abstract":"Chromium is an important constituent widely used in different industrial processes for production of various synthetic materials. For evaluation of workers' exposure to trace toxic metal of Cr (III), environmental and biological monitoring are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to analysis. The use of solid-phase extraction (SPE) has grown and is a fertile technique of sample preparation as it provides better results than those produced by liquid-liquid extraction (LLE). SPE using mini columns filled with XAD-4 resin was optimized regarding to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume, elution volume, amount of resins, and sample matrix interferences. Chromium was retained on solid sorbent and was eluted with 2 M HNO(3) followed by simple determination of analytes by using flame atomic absorption spectrometry. Obtained recoveries of metal ion were more than 92%. The optimized procedure was also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Through this study, suitable results were obtained for relative standard deviation, therefore, it is concluded that, this optimized method can be considered to be successful in simplifying sample preparation for trace residue analysis of Cr in different matrices for evaluation of occupational and environmental exposures. To evaluate occupational exposure to chromium, 16 urine samples were taken, prepared, and analyzed based on optimized procedure.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"2 ","pages":"125-32"},"PeriodicalIF":0.0,"publicationDate":"2007-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716808/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40017679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hazard identification on a single cell level using a laser beam. 使用激光束在单个细胞水平上进行危险识别。

Analytical Chemistry Insights Pub Date : 2007-12-06

Xing-Zheng Wu, Tomohisa Kato, Yumiko Tsuji, Satoshi Terada

{"title":"Hazard identification on a single cell level using a laser beam.","authors":"Xing-Zheng Wu, Tomohisa Kato, Yumiko Tsuji, Satoshi Terada","doi":"","DOIUrl":"","url":null,"abstract":"This research shows a novel method for hazard identification of a chemical and UV light on a single cell level with a laser probe beam. The laser probe beam was passed through interface of cell membrane/culture medium of a cultured human hepatoblastoma cell line HepG2. Deflection of the laser probe beam, which was induced by changes in concentration gradients due to the active materials movement across the cell membrane, was monitored. When a toxic hazard existed, a living cell was expected to be killed or injured, or cellular behaviors to be changed greatly. Then, the changing deflection signal from the living cell would become unchanged or altered in a different way. This was successfully demonstrated with cytotoxicity of UV light and H(2)O(2). Most of the cultured HepG2 cells showed changing deflection signals after 10 min illumination of UV-visible light longer than 370 nm, while almost all HepG2 cells showed unchanged deflection signal after 10 min illumination of UV-visible light with wavelength longer than 330 nm. The results suggested that UV light between 330-370 nm could kill the cells. Additions of H(2)O(2) solution with different concentrations to the cell cultures caused the changing deflection signal from a living cell either unchanged or changed in different trend, suggesting toxicity of H(2)O(2) to the cells. The results from the beam deflection detection agreed well with those obtained by the conventional trypane blue method.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"2 ","pages":"119-24"},"PeriodicalIF":0.0,"publicationDate":"2007-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40017678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identification of cysteine proteases and screening of cysteine protease inhibitors in biological samples by a two-dimensional gel system of zymography and reverse zymography. 半胱氨酸蛋白酶的鉴定和半胱氨酸蛋白酶抑制剂的筛选在生物样品的二维凝胶系统的酶和反酶。

Analytical Chemistry Insights Pub Date : 2007-11-18

Eiichi Saitoh, Shinya Yamamoto, Eishiro Okamoto, Yoshimi Hayakawa, Takashi Hoshino, Ritsuko Sato, Satoko Isemura, Sadami Ohtsubo, Masayuki Taniguchi

{"title":"Identification of cysteine proteases and screening of cysteine protease inhibitors in biological samples by a two-dimensional gel system of zymography and reverse zymography.","authors":"Eiichi Saitoh, Shinya Yamamoto, Eishiro Okamoto, Yoshimi Hayakawa, Takashi Hoshino, Ritsuko Sato, Satoko Isemura, Sadami Ohtsubo, Masayuki Taniguchi","doi":"","DOIUrl":"","url":null,"abstract":"We have developed a two-dimensional (2D-) gel system of zymography and reverse zymography for the detection and characterization of proteases and protease inhibitors. Isoelectric focusing (IEF) agarose gels with pH gradients were employed for separation in the first-dimension and sodium dodecyl sulfate (SDS)-polyacrylamide gel copolymerized with gelatin used for the second dimension. Proteases and protease inhibitors separated by IEF gel were applied on the second gel without trichloroacetic acid (TCA) fixation. Protease activity in the 2D-gel was visualized as transparent spots where gelatin substrate was digested after commassie brilliant blue (CBB) staining. Some of the transparent spots from the skin mucus extract of rainbow trout were determined to be a cysteine protease through use of E-64 or CA-074. In the reverse zymography technique, the gel was incubated with papain solution at 37 degrees C for 18 h. Cysteine protease inhibitors from broad bean seeds were detected as clear blue spots after CBB staining. The amino (N-) terminal sequences of four papain inhibitor spots thus detected were demonstrated to be identical to that of favin beta chain, a broad bean lectin. Taken together, our system can be considered to be an efficient technique for discovering and characterizing new proteases and protease inhibitors in biological samples. This is the first report describing a 2D-gel system of zymography and reverse zymography.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"2 ","pages":"51-9"},"PeriodicalIF":0.0,"publicationDate":"2007-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716818/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40017669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

NS-187 (INNO-406), a Bcr-Abl/Lyn dual tyrosine kinase inhibitor. NS-187 (INNO-406)， Bcr-Abl/Lyn双酪氨酸激酶抑制剂。

Analytical Chemistry Insights Pub Date : 2007-11-14

Tomoko Niwa, Tetsuo Asaki, Shinya Kimura

{"title":"NS-187 (INNO-406), a Bcr-Abl/Lyn dual tyrosine kinase inhibitor.","authors":"Tomoko Niwa, Tetsuo Asaki, Shinya Kimura","doi":"","DOIUrl":"","url":null,"abstract":"Protein kinases catalyze the transfer of the gamma-phosphoryl group of adenosine triphosphate (ATP) to the hydroxyl groups of protein side chains, and they play critical roles in regulating cellular signal transduction and other biochemical processes. They are attractive targets for today's drug discovery and development, and many pharmaceutical companies are intensively developing various kinds of protein kinase inhibitors. A good example is the recent success with the Bcr-Abl tyrosine kinase inhibitor imatinib mesylate (Gleevec) in the treatment of chronic myeloid leukemia. Though imatinib has dramatically improved the treatment of Bcr-Abl-positive chronic myeloid leukemia, resistance is often found in patients with advanced-stage disease. Several mechanisms have been proposed to explain this resistance, including point mutations within the Abl kinase domain, amplification of the bcr-abl gene, overexpression of the corresponding mRNA, increased drug efflux mediated by P-glycoprotein, and activation of the Src-family kinase (SFK) Lyn. We set out to develop a novel drug whose affinity for Abl is higher than that of imatinib and whose specificity in inhibiting Lyn is higher than that of SFK/Abl inhibitors such as dasatinib (Sprycel) or bosutinib (SKI-606). Our work has led to the development of NS-187 (INNO-406), a novel Abl/Lyn dual tyrosine kinase inhibitor with clinical prospects. To provide an overview of how a selective kinase inhibitor has been developed, this review presents chemical-modification studies carried out with the guidance of molecular modeling, the structural basis for the high potency and selectivity of NS-187 based on the X-ray structure of the NS-187/Abl complex, and the biological profiling of NS-187, including site-directed mutagenesis experiments.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"2 ","pages":"93-106"},"PeriodicalIF":0.0,"publicationDate":"2007-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716809/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40017675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A practical approach to red blood cell folate analysis. 红细胞叶酸分析的实用方法。

Analytical Chemistry Insights Pub Date : 2007-11-14

Chandrika J Piyathilake, Constance B Robinson, Phillip Cornwell

{"title":"A practical approach to red blood cell folate analysis.","authors":"Chandrika J Piyathilake, Constance B Robinson, Phillip Cornwell","doi":"","DOIUrl":"","url":null,"abstract":"The measurement of folate in red blood cells (RBCs) is preferred since it reflects long-term folate status in the body compared to plasma/serum folate which may be influenced by recent dietary intake. The commonly accepted technique for RBC folate analysis involves preparation of a hemolysate using a fresh whole blood sample. Hematocrit and plasma folate concentrations are needed to calculate RBC folate values. Because of the need for immediate access to a laboratory where processing can be performed, it may not be practical to assess RBC folate status using this method in field-based epidemiological studies. It is however, feasible to isolate packed RBSs from a blood sample under these conditions. The purpose of this study is to validate RBC folate analysis using packed red cells by comparing the RBC folate values obtained by hemolysate method (routine assay) with those obtained by using packed RBCs (new assay) in the same individuals (n = 50) using the folate microbiological assay. The correlation between plasma folate and the routine RBC folate assay (r = 0.58, p = 0.001) and the correlation between plasma folate and the new RBC folate assay was statistically significant (r = 0.55, p = 0.001). The correlation between RBC folate by the routine assay and new assay was also statistically significant (r = 0.78, p < 0.001). We conclude that measurement of folate in packed RBC is a practical approach in assessing long-term folate status in field-based and or larger scale epidemiological studies where an immediate access to a laboratory is unavailable for necessary sample processing for the routine RBC folate assay.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"2 ","pages":"107-10"},"PeriodicalIF":0.0,"publicationDate":"2007-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716806/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40017676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

UV-Vis spectrophotometrical and analytical methodology for the determination of singlet oxygen in new antibacterials drugs. 测定新型抗菌药物中单线态氧的紫外可见分光光度法和分析方法。

Analytical Chemistry Insights Pub Date : 2007-11-11

Tamara Zoltan, Franklin Vargas, Carla Izzo

引用次数: 0

Possible impact of salivary influence on cytokine analysis in exhaled breath condensate. 唾液对呼出冷凝水中细胞因子分析的可能影响。

Analytical Chemistry Insights Pub Date : 2007-10-12

T Ichikawa, K Matsunaga, Y Minakata, S Yanagisawa, K Ueshima, K Akamatsu, T Hirano, M Nakanishi, H Sugiura, T Yamagata, M Ichinose

{"title":"Possible impact of salivary influence on cytokine analysis in exhaled breath condensate.","authors":"T Ichikawa, K Matsunaga, Y Minakata, S Yanagisawa, K Ueshima, K Akamatsu, T Hirano, M Nakanishi, H Sugiura, T Yamagata, M Ichinose","doi":"","DOIUrl":"","url":null,"abstract":"Background: Exhaled breath condensate (EBC) is thought to contain substances of the lower airway epithelial lining fluid (ELF) aerosolized by turbulent flow. However, contamination by saliva may affect the EBC when collected orally.Objective: The purpose of this study was to compare the cytokine expression levels in EBC with those in saliva, and to clarify the influence of saliva on cytokine measurements of EBC.Methods: EBC and saliva samples were obtained from 10 adult subjects with stable asthma. To estimate differences in the contents of substances between EBC and saliva, the total protein concentration of each sample was measured. Further, we also measured the total protein concentration of ELF obtained from another patient group with suspected lung cancer using a micro sampling probe during bronchoscopic examination and roughly estimated the dilution of EBC by comparing the total protein concentration of EBC and ELF from those two patient groups. The cytokine expression levels of EBC and saliva from asthmatic group were assessed by a cytokine protein array.Results: The mean total protein concentrations in EBC, saliva and ELF were 4.6 microg/ml, 2,398 microg/ml and 14,111 microg/ml, respectively. The dilution of EBC could be estimated as 1:3000. Forty cytokines were analyzed by a cytokine protein array and each cytokine expression level of EBC was found to be different from that of saliva. Corrected by the total protein concentration, all cytokine expression levels of EBC were significantly higher than those of saliva.Conclusion: These results suggest that the salivary influence on the cytokine assessment in EBC may be negligible.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"2 ","pages":"85-92"},"PeriodicalIF":0.0,"publicationDate":"2007-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716811/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40017674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enantioselective gas chromatographic separation of racemic N-alkylated barbiturates: application of C11-Chirasil-Dex as chiral stationary phase in GC. 外消旋n -烷基化巴比妥酸酯的对映选择性气相色谱分离:C11-Chirasil-Dex作为GC手性固定相的应用。

Analytical Chemistry Insights Pub Date : 2007-09-18

Ashraf Ghanem

引用次数: 0

Vibratory reaction unit for the rapid analysis of proteins and glycochains. 用于快速分析蛋白质和糖链的振动反应单元。

Analytical Chemistry Insights Pub Date : 2007-09-17

Yukie Sasakura, Makoto Nogami, Noriko Kobayashi, Katsuhiro Kanda

{"title":"Vibratory reaction unit for the rapid analysis of proteins and glycochains.","authors":"Yukie Sasakura, Makoto Nogami, Noriko Kobayashi, Katsuhiro Kanda","doi":"","DOIUrl":"","url":null,"abstract":"A protein digestion system using immobilized enzymes for protein identification and glycochain analyses has been developed, and a vibration reaction unit for micro-scale sample convection on an enzyme-immobilized solid surface was constructed. BSA as a model substrate was digested by this unit, and was successfully identified by mass spectrometry (MS) analyses. Compared to the conventional liquid-phase digestion, the reaction unit increased the number of matched peptides from 9 to 26, protein score from 455 to 1247, and sequence coverage from 21% to 48%. Glycopeptidase F (NGF), an enzyme that cleaves N-glycans from glycoproteins, was also immobilized and used to remove the glycochains from human immunoglobulin G (IgG). Trypsin and NGF were immobilized on the same solid surface and used to remove glycochains from IgG in single-step. Glycochains were labeled with fluorescent reagent and analyzed by HPLC. Several peaks corresponding to the glycochains of IgG were detected. These results suggested that the single-step digestion system, by immobilized multiple enzymes (trypsin and NGF) would be effective for the rapid structural analysis of glycoproteins.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"2 ","pages":"69-74"},"PeriodicalIF":0.0,"publicationDate":"2007-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716815/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40017671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0