1.Determination of glyphosate in air of workplaces by ion chromatography.
Ren-nan ZHANG ; Hua-liang LIU ; Zong-li HUO ; Feng ZHANG ; Yong-jian MA ; Bao-li ZHU ; Jian-rui DOU ; Yi-yang MAO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2013;31(10):779-782
OBJECTIVETo establish a method for determining glyphosate in the air of workplaces by ion chromatography.
METHODSUltra-fine glass fiber filter paper was used to collect glyphosate from the workplace air. After being ultrasonically eluted with deionized water, samples were determined by ion chromatography using a conductivity detector.
RESULTSWithin the range of 0.05-1.00 mg/L, a linear relationship was found with a limit of detection of 0.003 mg/m(3). The minimum detectable concentration was 0.000 41 mg/m(3) (calculated by sampling 75 L of air). For three different concentrations of glyphosate, the intra-batch relative standard deviations (RSDs) were 1.8%, 1.6%, and 0.8%, respectively, and the inter-batch RSDs were 1.9%, 2.1%, and 2.2%, respectively. The recovery rate ranged from 94.8% to 97.4%. The elution efficiency ranged from 94.5% to 96.7%. The sampling efficiency was 100%. Samples could be stored at room temperature for at least 7 days.
CONCLUSIONThis presented method meets the requirements of Guide for establishing occupational health standards-Part 4: Determination methods of air chemicals in workplace and is feasible for determination of glyphosate in the air of workplaces.
Air Pollutants, Occupational ; analysis ; Chromatography, Gas ; Glycine ; analogs & derivatives ; analysis ; Workplace
3.Isolation and Partial Characterization of a 50 kDa Hemin-regulated Cell Envelope Protein from Prevotella nigrescens.
Kyung Mi KIM ; Jeom IL CHOI ; Sung Jo KIM
The Journal of the Korean Academy of Periodontology 2002;32(2):351-360
In the study presented here, identification, purification, and partial characterization of a hemin-regulated protein in Prevotella nigrescens were carried out. The results of this study confirm that the availability of hemin influences the expression of a selected membrane protein as well as the growth rate of P. nigrescens ATCC 33563. The 50 kDa cell envelope associated protein, whose expression is hemin regulated, is considered to be a putative hemin-binding protein from P. nigrescens. Disulfide bonds were not present in this protein, and N'-terminal amino acid sequence analysis revealed that this protein belongs to a new, so far undescribed protein. The 50 kDa protein was found to be rich in hydrophilic amino acids, with glycine comprising approximately 60% of the total amino acids. The study described here is the first to identify, purify, and biochemically characterize a putative hemin-binding protein from P. nigrescens. Work is in progress to further characterize the molecular structure of this protein.
Amino Acids
;
Glycine
;
Hemin
;
Membrane Proteins
;
Molecular Structure
;
Prevotella nigrescens*
;
Prevotella*
;
Sequence Analysis, Protein
4.Discussion of the application of three-point interaction principle to the phenylglycine racemic compound in IR spectrometry and its enantiomers separation in HPLC.
Yi SHEN ; Da-nian YI ; Ji-ning LIU
Acta Pharmaceutica Sinica 2002;37(8):636-638
AIMTo discuss the relationship between the three-point interaction principle in the stereoselective separation of chromatography and applying this principle to survey the infrared spectrometry of racemate.
METHODSIn proving the applicability of the three-point interaction principal in IR spectrometry, a special case was found that phenylglycine did not obtain enantioselective separation on the chiral column but its IR spectrometry still obey this principle and explained such special case by experiment.
RESULTSAfter an equal quantity of solid crystal of d-phenylglycine and l-phenylglycine were mixed and ground for several minutes, they transformed to racemic compound. X-powder diffraction also confirmed this fact.
CONCLUSIONThe three-point principle was relatively reliable when it was used in the enantioselective chromatography separation and the IR spectrometric analysis. The reason of the fact that phenylglycine was not separated by chiral column can be explained by the fact that the acting force between the three polarity groups in the enantiomers is so strong that they can not form the instantaneous diastereoisomer with the chiral column, it was agreeable with the phenomenon that racemic mixture easily became racemic compound only by simply grinding the mixture in IR spectrometric experiment.
Chromatography, High Pressure Liquid ; Glycine ; analogs & derivatives ; analysis ; chemistry ; Orosomucoid ; chemistry ; Spectrophotometry, Infrared ; Stereoisomerism
5.Determination of underivatized glycine and proline in vinegar turtle shell by HPLC-ELSD.
Xinyu WANG ; Xiaomei TAN ; Mingze GAO ; Jinlong PENG
China Journal of Chinese Materia Medica 2011;36(15):2107-2109
OBJECTIVETo establish a method to determine the underivatized glycine (Gly) and proline (Pro) in vinegar turtle shell.
METHODAn HPLC-ELSD method was conducted on a Prevail C18 column (4.6 mm x 250 mm, 5 microm) with the mobile phase of acetonitrile and 0.7% trifluoroacetic acid solution (containing 5.0 mmol x L(-1) heptafluorobutyric acid), and elution time was 15 min.
RESULTThe calibration curves were showed good linearity within the concentration range of 0.14-0.6 g x L(-1). The average recoveries were 101.2% and 102.5%, and RSD were 1.9% and 2.5%, respectively.
CONCLUSIONSince this method needs neither the special amino acid analyzer nor derivation of amino acid., it is efficient, simple and accurate., which could be used for quality control of vinegar turtle shell.
Animal Shells ; chemistry ; Animals ; Chromatography, High Pressure Liquid ; Glycine ; analysis ; Proline ; analysis ; Quality Control ; Reference Standards ; Reproducibility of Results ; Turtles
6.Identification of a Novel Mutation in the MCCC2 Gene of a Korean Patient with 3-Methylcrotonyl-CoA Carboxylase Deficiency.
Byung Chul KIM ; Dong Hwan LEE ; Chang Seok KI ; Hyung Doo PARK ; Tae Youn CHOI ; Jeong Won SHIN ; Yong Wha LEE
Laboratory Medicine Online 2011;1(2):115-119
3-methylcrotonyl-CoA carboxylase deficiency is an autosomal recessive disorder characterized by a defect in leucine catabolism. We report the case of an 80-day-old patient with 3-methylcrotonyl-CoA carboxylase deficiency who had elevated levels of 3-hydroxyisovalerylcarnitine (45.56 micromol/L; reference range, <0.65 micromol/L), which was detected using tandem mass spectrometry during newborn screening, and elevated levels of 3-hydroxyisovaleric acid (375.75 mmol/mol Cr) and 3-methylcrotonylglycine (502.36 mmol/mol Cr ), which were detected in urine organic acid analysis. We performed direct sequence analysis of all the exons of the MCCC1 and MCCC2 genes. No mutations were detected in the direct sequence analysis of MCCC1. However sequencing of the MCCC2 gene revealed a mutation caused by a heterozygous G to C transversion [c.313G>C (p.Gly105Arg)] at nucleotide position 313 and a mutation caused by a heterozygous A to T transversion [c.1252A>T (p.lle418Phe)] at nucleotide position 1252. Identification of these 2 novel MCCC2 gene mutations in our patient suggested that analysis of the MCCC1 and MCCC2 genes might prove useful in the diagnosis of 3-methylcrotonyl-CoA carboxylase deficiency.
Carnitine
;
Exons
;
Glycine
;
Humans
;
Infant, Newborn
;
Leucine
;
Mass Screening
;
Reference Values
;
Sequence Analysis
;
Tandem Mass Spectrometry
;
Valerates
7.Glycine receptors contribute to cytoprotection of glycine in myocardial cells.
Ren-bin QI ; Jun-yan ZHANG ; Da-xiang LU ; Hua-dong WANG ; Hai-hua WANG ; Chu-Jie LI
Chinese Medical Journal 2007;120(10):915-921
BACKGROUNDThe classic glycine receptor (GlyR) in the central nervous system is a ligand-gated membrane-spanning ion channel. Recent studies have provided evidence for the existence of GlyR in endothelial cells, renal proximal tubular cells and most leukocytes. In contrast, no evidence for GlyR in myocardial cells has been found so far. Our recent researches have showed that glycine could protect myocardial cells from the damage induced by lipopolysaccharide (LPS). Further studies suggest that myocardial cells could contain GlyR or binding site of glycine.
METHODSIn isolated rat heart damaged by LPS, the myocardial monophasic action potential (MAP), the heart rate (HR), the myocardial tension and the activities of lactate dehydrogenase (LDH) from the coronary effluent were determined. The concentration of intracellular free calcium ([Ca(2+)](i)) was measured in cardiomyocytes injured by LPS and by hypoxia/reoxygenation (H/R), which excludes the possibility that reduced calcium influx because of LPS neutralized by glycine. Immunohistochemistry was used to detect the GlyR in myocardial tissue. GlyR and its subunit in the purified cultured cardiomyocytes were identified by Western blotting.
RESULTSAlthough significant improvement in the MAP/MAPD(20), HR, and reduction in LDH release were observed in glycine + LPS hearts, myocardial tension did not recover. Further studies demonstrated that glycine could prevent rat mycordial cells from LPS and hypoxia/reoxygenation injury (no endotoxin) by attenuating calcium influx. Immunohistochemistry exhibited a positive green-fluorescence signaling along the cardiac muscle fibers. Western blotting shows that the purified cultured cardiomyocytes express GlyR beta subunit, but GlyR alpha1 subunit could not be detected.
CONCLUSIONSThe results suggest that glycine receptor is expressed in cardiomyocytes and participates in cytoprotection from LPS and hypoxia/reoxygenation injury. Glycine could directly activate GlyR on the cardiomyocytes and prevent calcium influx into the cardiomyocytes.
Animals ; Blood Pressure ; drug effects ; Blotting, Western ; Calcium ; metabolism ; Cytoprotection ; Glycine ; pharmacology ; Heart ; drug effects ; physiology ; Heart Rate ; drug effects ; Immunohistochemistry ; L-Lactate Dehydrogenase ; secretion ; Lipopolysaccharides ; toxicity ; Male ; Rats ; Rats, Sprague-Dawley ; Receptors, Glycine ; analysis ; physiology
8.Effect of hypocapnia on extracellular glutamate and glycine concentrations during peri-ischemic period in the rabbit hippocampus.
Kyu Taek CHOI ; Jung Kil CHUNG ; Chun Sik KWAK ; Hae Kyu KIM
Journal of Korean Medical Science 1994;9(5):394-401
Glutamate (GLU) is a neurotransmitter. Massive release of GLU and glycine (GLY) into the brain's extracellular space may be triggered by ischemia, and may result in acute neuronal lysis or delayed neuronal death. The aim of this study was to evaluate the possible relationship between hyperventilation and the level of GLU and GLY during brain ischemia. Rabbits were anesthetized with halothane and oxygen. Group 1 was allowed to hyperventilate (PaCO2 25-35 mmHg). PaCO2 was maintained throughout the study. Group 2 was a normal control group that maintained normocapnia. Two global cerebral ischemic episodes were produced. Microdialysate was collected during the peri-ischemic and reperfusion periods from the dorsal hippocampus. GLU and GLY concentrations were determined using high-performance liquid chromatography. In the control group, GLU and GLY were significantly elevated during each episode of ischemia; these levels returned to baseline within 10 minutes after reperfusion. In contrast, in the hyperventilation group GLU and GLY concentrations increased during ischemia, but they were not statistically significant. We were able to demonstrate that hypocapnia during periischemic period lowered extracellular GLU and GLY concentrations. These results can explain a part of the protective action of hypocapnia during cerebral ischemia.
Animal
;
Brain Ischemia/*metabolism
;
Glutamic Acid/*analysis
;
Glycine/*analysis
;
Hippocampus/*chemistry
;
Hyperventilation/metabolism
;
Hypocapnia/*metabolism
;
Potassium/metabolism
;
Potassium Channels/physiology
;
Rabbits
;
Support, Non-U.S. Gov't
9.Effect of single-used borneol and combining it with diazepam on content of neurotransmitter in corpus striatum of rats.
Na ZHANG ; Ping LIU ; Xinrong HE
China Journal of Chinese Materia Medica 2011;36(22):3180-3183
OBJECTIVETo research the content changes of excitatory neurotransmitter and inhibitory neurotransmitter in corpus striatum of rats after single-used borneol and combining it with diazepam in hope of comprehending the activity of borneol on central nervous system and to observe whether borneol could increase the penetration of other drugs into the brain.
METHODThe content of four amino acids neurotransmitters in corpus striatum of rats were sampled by brain microdialysis technology at different time after administration and were determined by RP-HPLC which involved pre-column derivation with orthophthaladehyde (OPA), using phosphate gradient elution and fluorescence detection to detect the content of excitatory neurotransmitter aspartate (Asp), glutamate (Glu) and inhibitory neurotransmitter glycine (Gly), gamma-aminobutyric acid (GABA) in standards and samples and carry on statistical analysis.
RESULTThe content of both Gly and GABA in corpus striatum of rats with borneol increased significantly, compared with diazepam group (P < 0.05), while Asp and Glu showed no significant difference.
CONCLUSIONBorneol can improve permeability of diazepam through BBB.
Animals ; Aspartic Acid ; analysis ; Blood-Brain Barrier ; Bornanes ; administration & dosage ; pharmacology ; Corpus Striatum ; chemistry ; drug effects ; Diazepam ; administration & dosage ; pharmacology ; Glutamic Acid ; analysis ; Glycine ; analysis ; Male ; Neurotransmitter Agents ; analysis ; Rats ; Rats, Sprague-Dawley ; gamma-Aminobutyric Acid ; analysis
10.Co-existence of calcium-binding proteins and gamma-aminobutyric acid or glycine in neurons of the rat medullary dorsal horn.
Wen WANG ; Sheng-xi WU ; Yun-qing LI
Chinese Medical Journal 2004;117(3):430-433
BACKGROUNDWe investigated the co-expression of calbindin-D28k (CB), calretinin (CR) and parvalbumin (PV, a combination of the three is referred to as CaBPs) with gamma-aminobutyric acid (GABA) or glycine in neurons of the rat medullary dorsal horn (MDH).
METHODSImmunofluorescence histochemical double-staining for CaBPs and GABA or glycine was performed on the sections from rat MDH.
RESULTSCB-, CR-, PV-, GABA- and glycine-like immunoreactive (LI) neurons were differentially observed in all layers of the MDH, but particularly in lamina II. Neurons that exhibited immunoreactivity for both CaBPs and GABA or glycine were also observed mainly in lamina II. A few of them were found in laminae I and III. The percentages of neurons which co-expressed CB/GABA or CB/glycine out of the total numbers of CB- and GABA-LI neurons or CB- and glycine-LI neurons were 5.3% and 12.1% or 4.1% and 10.0%, respectively. The ratios of CR/GABA or CR/glycine co-existing neurons out of the total numbers of CR- and GABA-LI neurons or CR- and glycine-LI neurons were 5.8% and 7.6% or 4.4% and 7.1%, respectively. The rates of PV/GABA or PV/glycine co-localized neurons out of the total numbers of PV- and GABA-LI neurons or PV- and glycine-LI neurons were 11.1% and 5.1% or 9.9% and 5.1%, respectively.
CONCLUSIONThe results indicate that some neurons in the MDH contain both CaBPs and GABA or glycine.
Animals ; Calbindin 1 ; Calbindin 2 ; Calbindins ; Calcium-Binding Proteins ; analysis ; Fluorescent Antibody Technique ; Glycine ; analysis ; Immunohistochemistry ; Medulla Oblongata ; cytology ; Parvalbumins ; analysis ; Posterior Horn Cells ; chemistry ; Rats ; S100 Calcium Binding Protein G ; analysis ; gamma-Aminobutyric Acid ; analysis