• The Korean Journal of Physiology and Pharmacology
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• 제17권1호
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• pp.89-97
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• 2013

Developing an animal model for a specific disease is very important in the understanding of the underlying mechanism of the disease and allows testing of newly developed new drugs before human application. However, which of the plethora of experimental animal species to use in model development can be perplexing. Administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a very well known method to induce the symptoms of Parkinson's disease in mice. But, there is very limited information about the different sensitivities to MPTP among mouse strains. Here, we tested three different mouse strains (C57BL/6, Balb-C, and ICR) as a Parkinsonian model by repeated MPTP injections. In addition to behavioral analysis, endogenous levels of dopamine and tetrahydrobiopterin in mice brain regions, such as striatum, substantia nigra, and hippocampus were directly quantified by liquid chromatography-tandem mass spectrometry. Repeated administrations of MPTP significantly affected the moving distances and rearing frequencies in all three mouse strains. The endogenous dopamine concentrations and expression levels of tyrosine hydroxylase were significantly decreased after the repeated injections, but tetrahydrobiopterin did not change in analyzed brain regions. However, susceptibilities of the mice to MPTP were differed based on the degree of behavioral change, dopamine concentration in brain regions, and expression levels of tyrosine hydroxylase, with C57BL/6 and Balb-C mice being more sensitive to the dopaminergic neuronal toxicity of MPTP than ICR mice.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.272-278
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• 2011

Bovine whey protein expression patterns of colostrum are much different from that of milk. Moreover, bovine colostrum is an important source of protective, nutritional and developmental factors for the newborn. However, to our knowledge, no research has been performed to date using a comparative proteomic method on the changes in the bovine whey proteome during the transition from colostrum to milk. This study therefore separated whey protein of days 1, 3, 7 and 21 after calving using two dimension electrophoresis. Differentially expressed proteins at different collection times were identified using high-performance liquid chromatography in tandem with mass spectrometry (LC/MS) and validated by enzyme-linked immunosorbent assay (ELISA) in order to understand the developmental changes in the bovine whey proteome during the transition from colostrum to milk. The expression patterns of whey protein of days 1 and 3 post-partum were similar except that immunoglobulin G was down-regulated on day 3, and four proteins were found to be down-regulated on days 7 and 21 compared with day 1 after delivering, including immunoglobulin G, immunoglobulin M, albumin, and lactotransferrin, which are involved in immunity and molecule transport. The results of this study confirm the comparative proteomic method has the advantage over other methods such as ELISA and immunoassays in that it can simultaneously detect more differentially expressed proteins. In addition, the difference in composition of milk indicates a need for adjustment of the colostrum feeding regimen to ensure a protective immunological status for newborn calves.

• KSBB Journal
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• 제30권5호
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• pp.230-238
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• 2015

Abnormal glycosylation can significantly affect the intrinsic functions (i.e., stability and solubility) of proteins and the extrinsic protein interactions with other biomolecules. For example, recombinant glycoprotein therapeutics needs proper glycosylation for optimal drug efficacy. Therefore, there has been a strong demand for rapid, sensitive and high-through-put glycomics tools for real-time monitoring and fast validation of the biotherapeutics glycosylation. Although liquid chromatography tandem mass spectrometry (LC-MS/MS) is one of the most powerful tools for the characterization of glycan structures, it is generally time consuming and requires highly skilled personnel to collect the data and analyze the results. Recently, as an alternative method, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS), which is a fast, robust and easy-to-use instrumentation, has been used for quantitative glycomics with various chemical derivatization techniques. In this review, we highlight the recent advances in MALDI-MS based quantitative glycan analysis according to the chemical derivatization strategies. Moreover, we address the application of MALDI-MS for high-throughput glycan analysis in many fields of clinical and biochemical engineering.

• 한국대기환경학회지
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• 제33권1호
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• pp.54-63
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• 2017

Atmospheric nitrogen containing organic compounds(e.g. amino acids) has attracted considerable attention from the viewpoint of the oceanic biogeochemical cycle of nitrogen as well as the long range transfer. However, only a few measurements of organic nitrogen compounds have been conducted due to analytical difficulties. In this study, total of nine amino acids such as Glutamic acid, Histidine, Arginine, Tyrosine, Cystine, Valine, Methionine, Phenylalanine, Lysine have been analytically determined by Liquid Chromatography - Mass Spectrometry Mass Spectrometry (LC-MSMS). As results, Fragmentor Voltage (FV), Precursor Ion, Collision Energy, Product Ion related to individual amino acid compounds are shown. Based on the operational conditions, Lysine, Glutamine Acid, Tyrosine were analyzed during the China Oriented Smog Period. High concentrations of Lysine, Glutamine Acid, and Tyrosine are discussed with organic carbon (OC), elemental carbon (EC), and water soluble ions. The results can provide to understand the sources with aging process related to amino acids influenced by the long-range transport from the Yellow Sea area.

• Molecules and Cells
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• 제21권3호
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• pp.381-388
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• 2006

Heat shock proteins (Hsp) 70 are a ubiquitous family of molecular chaperones involved in many cellular processes. A yeast strain, ssa1/2, with two functionally redundant cytosolic Hsp70s (SSA1 and SSA2) deleted shows thermotolerance comparable to mildly heatshocked wild type yeast, as well as increased protein synthesis and ubiquitin-proteasome protein degradation. Since mRNA abundance does not always correlate well with protein expression levels it is essential to study proteins directly. We used a gel-based approach to identify stress-responsive proteins in the ssa1/2 mutant and identified 43 differentially expressed spots. These were trypsin-digested and analyzed by nano electrospray ionization liquid chromatography tandem mass spectrometry (nESI-LC-MS/MS). A total of 22 non-redundant proteins were identified, 11 of which were confirmed by N-terminal sequencing. Nine proteins, most of which were up-regulated (2-fold or more) in the ssa1/2 mutant, proved to be stress-inducible proteins such as molecular chaperones and anti-oxidant proteins, or proteins related to carbohydrate metabolism. Interestingly, a translational factor Hyp2p up-regulated in the mutant was also found to be highly phosphorylated. These results indicate that the cytosolic Hsp70s, Ssa1p and Ssa2p, regulate an abundance of proteins mainly involved in stress responses and protein synthesis.

• 약학회지
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• 제60권3호
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• pp.112-117
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• 2016

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of caffeine in forensic aqueous sample. The centrifuged sample ($100{\mu}l$) was diluted 50-fold with distilled water. The diluted sample ($400{\mu}l$) was then diluted further with $200{\mu}l$ of 0.1% formic acid solution and $400{\mu}l$ of acetonitrile containing 500 ng of caffeine-(3-methyl-$^{13}C_3$) prior to LC-MS/MS analysis. The mobile phase was composed of 0.1% formic acid in distilled water (A) and acetonitrile (B). Chromatographic separation was performed by using a Zorbax SB-C18 ($100mm{\times}2.1mm$ i.d., $3.5{\mu}m$) column and caffeine was eluted within 1.1 min. Linear least-squares regression with a 1/x weighting factor was used to generate a calibration curve with the coefficients of determination ($r^2=0.9983$). The lower limit of quantification was $25ng/ml$ for the analyte. The process efficiency was 98.6~100.1%. Intra- and inter-day precisions were not more than 2.1% and 1.7%, while intra- and inter-day accuracies were ranged from -6.8 to 4.5%, respectively. The suitability of the method was examined by analyzing unknown forensic aqueous samples.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1131-1136
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• 2013

Parabens, the esters of p-hydroxybenzoic acid, have been widely used as antimicrobial preservatives in cosmetic products, drugs, and processed foods and beverages. However, some parabens have been shown to have weak estrogenic effects through in vivo and in vitro studies. Because such widespread use has raised concerns about the potential human health risks associated with exposure to parabens, we developed a simultaneous analytical method to quantify 4 parabens (methyl, ethyl, propyl, and butyl) in human urine, by using solid-phase extraction and high-performance liquid chromatography coupled with triple quadrupole mass spectrometry. This method showed good specificity, linearity ($R^2$ > 0.999), accuracy (92.2-112.4%), precision (0.9-9.6%, CV), and recovery (95.7-102.0%). The LOQs for the 4 parabens were 1.0, 0.5, 0.2, and 0.5 ng/mL, respectively. This method could be used for quick and accurate analysis of a large number of human samples in epidemiological studies to assess the prevalence of human exposure to parabens.

• 한국동물위생학회지
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• 제25권1호
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• pp.23-29
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• 2002

A method was developed to separate, detect and qualify aldicarb, bendiocarb, carbaryl, carbofuran, ethiofencarb, methomyl, methiocarb, propoxur in meats and fruits. Experimental beef and fork samples were fortified with 0.05mg/kg of carbamate pesticides for analysis. Carbamate-detected pear by HPLC fluorescence detector(HPLC/FLS) are extracted with acetonitril and refined by solid phase extraction(SPE) filled with aminopropyl-bonded silca, In the following step, the injected materials into LC/MS are analyzed to result in the fact that bendiocarb, carbaryl, carbofuran, ethiofencarb, methomyl, methiocarb, propoxur presents several sorts of fraction ions following with; [M+H]$^{+}$, [M+Na]$^{+}$,［M-CONH$CH_3$]$^{+}$, [M-OCONH$CH_3$]$^{+}$. In addition, ethiofencarb presents [M-SCH$_2$$CH_3$]$^{+}$ ion distinctive and aldicarb presents [M+Na]$^{+}$ and [M-OCONH$CH_3$]$^{+}$ ion which is the most decisive fraction ion for pesticides such as bendiocarb, carbaryl, carbofuran, ethiofencarb, methiocarb, methomyl, propoxur excluding [M+H]$^{+}$ ion. However, [M-OCONH$CH_3$]$^{+}$ and [M-OCONH$CH_3$]$^{+}$ fraction ion charactering carbamate pesticides are detected most efficiently with fragment voltage 50ev. As a result, for rluantitative analysis, [M+Na]$^{+}$ ion is the most decisive ion for detection of aldicarb and [M+H]$^{+}$ ion is the most decisive fraction ion for Pesticides such as bendiocarb, carbaryl, carbofuran, ethiofencarb, methiocarb, methomyl, propoxur. Carbaryl-detected pear by HPLC/FLS are analyzed by L/MS and the result shows that [M+H]$^{+}$ and [M-CONH$CH_3$]$^{+}$ ions charactering carbaryl are detected.ering carbaryl are detected.

• Environmental Analysis Health and Toxicology
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• 제26권
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• pp.12.1-12.7
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• 2011

Objectives: Perchlorate is an emerging contaminant that is found everywhere, including various foods. Perchlorate is known to disturb the production of thyroid hormones and leads to mental disorders in fetuses and infants, as well as metabolic problems in adults. In this study, we attempted to establish an LC-MS/MS method for measuring perchlorate in dairy products and used this developed method to investigate perchlorate levels in Korean milk and yogurt samples. Methods: The developed method of perchlorate analysis requires a shaker and 1% acetic acid/acetonitrile as the extracting solvent. Briefly, the samples were extracted and then centrifuged (4000 rpm, 1hour), and the supernatant was then passed through a $Envi^{TM}$ Carb SPE cartridge that had been prewashed sequentially with 6 mL of acetonitrile and 6 mL of 1% acetic acid in water. The final volume of the sample extract was adjusted to 40 mL with reagent water and the final sample was filtered through a 0.20-${\mu}m$ pore size PTFE (Polytetrafluoroethylene) syringe filter prior to LC-MS/MS. Results: The average levels of perchlorate in milk and yogurt samples were $5.63{\pm}3.49\;{\mu}g/L$ and $3.65{\pm}2.42\;{\mu}g/L$, respectively. The perchlorate levels observed in milk samples in this study were similar to those reported from China, Japan, and the United States. Conclusions: The exposure of Koreans to perchlorate through the consumption of dairy products was calculated based on the results of this study. For all age groups, the calculated exposure to perchlorate was below the reference of dose (0.7 ${\mu}g/kg$-day) proposed by the National Academy of Science, USA, but the perchlorate exposure of children was higher than that of adults. Therefore, further investigation of perchlorate in other food samples is needed to enable a more exact assessment of exposure of children to perchlorate.

• 생약학회지
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• 제43권1호
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• pp.10-15
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• 2012

An accurate and sensitive analysis method was established for simultaneous determination of three bioactive compounds (glycyrrhizin, 6-gingerol and ginsenoside Rg3) in the Ejung Tang with high-performance liquid chromatography (HPLC)-photodiode array detection (DAD)-electrospray ionization (ESI)-Mass spectrometry (MS). The optimizing chromatographic separations a were acquired by an $C_{18}$ column ($5{\mu}m$, $4.6I.D{\times}250mm$, SHISHEDO) using gradient elution with water comprising 0.1% TFA(trifluoroacetic acid) and acetonitrile at a performing temperature of $35^{\circ}C$. Flow rate was 1.0 ml/min. A detection UV wavelength set at 205 nm and 250 nm. The three compounds were identified by electrospray ionization mass spectrometry. All calibration curves indicated great linear regression within test ranges ($R^2>0.9997$). The established method provided acceptable precision and accuracy. The relative standard deviations (RSDs) of intra-day and inter-day were less than 2.00% and 3.00%, respectively. The recoveries were found to range from 94.49 to 101.10% for the three compounds analyzed. These results showed that this method was effective and reliable for quality control of Eiung-Tang.