Objective To establish a method for determination of the azide ions in blood by gas chromatography-mass spectrometry （GC-MS） following pentafluorobenzyl derivatization. Methods A blood sample of 0.2 mL was placed into a 10 mL glass test tube, and the internal standard sodium cyanide, derivatization reagent pentafluorobenzyl bromide and catalyst tetradecyl benzyl dimethyl ammonium chloride were added in turn. After vortex mixing, the mixture was heated with low-power microwave for 3 min. After centrifugation, the organic phase was taken for GC-MS analysis. Results The azide ions in blood had a good linear relationship in the mass concentration range of 0.5 to 20 μg/mL. The lowest detection limit was 0.25 μg/mL and the relative recovery was 91.36%-94.58%. The method was successfully applied to a case of death from sodium azide poisoning. The mass concentration of azide ions in the blood of the dead was 11.11 μg/mL. Conclusion The method developed in this paper has strong specificity and is easy to operate, which is suitable for the rapid detection of azide ions in blood.
Azides ; Gas Chromatography-Mass Spectrometry ; Humans ; Ions

BACKGROUND AND OBJECTIVES: Glutaraldehyde (GA) has been used as a representative method of tissue preservation in cardiovascular surgery. However, GA has showed limited durability including calcification, mechanical failure and toxicity. To overcome those unsolved problems, we analyzed the crosslinking differences of primary amines, GA and genipin in their mechanical and biochemical properties with a single or double crosslinking agent for clinical application. MATERIALS AND METHODS: Samples were divided into 3 groups; control, single crosslinking fixation and double crosslinking fixation after decellurarization using bovine pericardium. For analysis of the biochemical and mechanical properties of each crosslinking method, tensile strength, percentage strain, thermal stability, resistance to pronase, nynhydrin and cytotoxicity test were studied. RESULTS: Combined hexamethylene diamine and suberic acid in the carbodiimide hydrochloride/N-hydroxysucinimide solution (EDC/NHS) after decellurarization, tensile strength and strain percentage were not statistically significant compared to the single crosslinking treated groups (p>0.05). Tissue crosslinking stability was weak in single treatment of diphenylphosphoryl azide, suberic acid, low concentration of EDC, hexamethylene diamine and procyanidin groups, but thermal stability and resistance to the pronase and ninhydrin were markedly increased in concentrated EDC/NHS or after combined double treatment with low concentration of GA or genipin (p<0.001). CONCLUSION: Single or double crosslinking with low concentration of carbodiimide, diphenylphosphonyl azide, procyanidin, suberic acid and hexane diamine were not as effective in mechanical, biochemical, cytotoxic and crosslinking properties compared to GA or genipin fixation, but their mechanical and chemical properties were much improved when combined with low concentrations of GA or genipin in the double crosslinking process.
Amines ; Azides ; Biflavonoids ; Bioprosthesis ; Caprylates ; Catechin ; Dicarboxylic Acids ; Glutaral ; Iridoids ; Ninhydrin ; Pericardium ; Proanthocyanidins ; Pronase ; Sprains and Strains ; Tensile Strength ; Tissue Preservation

Polymerase chain reaction (PCR) can detect bacteria more rapidly than conventional plate counting. However DNA-based assays cannot distinguish between viable and dead cells due to persistence of DNA after cells have lost their vitality. Recently, propidium monoazide (PMA) treatment has been introduced. The purpose of this study is to evaluate the applicability of the PMA treatment and real-time PCR method for cell counting in comparison with plate counting and to evaluate the antibacterial efficacy of 2% CHX on E. faecalis using PMA treatment in combination with real-time PCR. Firstly, to elucidate the relationship between the proportion of viable cells and the real-time PCR signals after PMA treatment, mixtures with different ratios of viable and dead cells were used. Secondly, relative difference of viable cells using PMA treatment in combination with real-time PCR was compared with CFU by plate counting. Lastly, antibacterial efficacy of 2% CHX on E. faecalis was measured using PMA treatment in combination with real-time PCR. The results were as follows : 1. Ct value increased with decreasing proportion of viable E. faecalis. 2. There was correlation between viable cells measured by real-time PCR after PMA treatment and CFU by plate counting until Optical density (OD) value remains under 1.0. However, viable cells measured by real-time PCR after PMA treatment have decreased at 1.5 of OD value while CFU kept increasing. 3. Relative difference of viable E. faecalis decreased more after longer application of 2% CHX.
Azides ; Bacteria ; Cell Count ; Chlorhexidine ; DNA ; Enterococcus ; Enterococcus faecalis ; Polymerase Chain Reaction ; Propidium ; Real-Time Polymerase Chain Reaction

Grafting of poly (ethylene glycol) (PEG) on the surface of polysulfone (PSF) sheets by simultaneous or sequential UV irradiation with 4-azidobenzoic acid as the photocoupler was carried out. Water contact angle measurements showed that there was a great improvement of hydrophilicity on the grafted surface. X-ray photoelectron spectroscopy suggested that the area covered by PEG be 77.3% and 41.9% respectively after grafting by simultaneous and sequential pathways. With atomic force microscope (AFM), obvious difference in the shape and the phase mode was observed between surfaces of PEG-g-PSF sheets made by these two pathways. Evidences implied that simultaneous pathway would produce a branched PEG layer on the surface, while sequential pathway was coupled with a "pan-cake" PEG layer on it. This study provides the foundation for further advancement in tethering brush-like PEG on PSF hollow fiber membranes.
Azides ; chemistry ; Biocompatible Materials ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Membranes, Artificial ; Microscopy, Atomic Force ; Polyethylene Glycols ; chemistry ; Polymers ; chemistry ; Sulfones ; chemistry ; Ultraviolet Rays

PURPOSE: The aim of this study was to investigate bronchodilator responsiveness (BDR) following methacholine-induced bronchoconstriction and to determine differences in BDR according to clinical parameters in children with asthma. METHODS: The methacholine challenge test was performed in 145 children with mild to moderate asthma, and the provocative concentration causing a 20% decline in FEV1 (PC20) was determined. Immediately after the challenge test, patients were asked to inhale short-acting beta2-agonists (SABAs) to achieve BDR, which was assessed as the change in FEV1% predictedx100/post-methacholine FEV1% predicted. For each subject, the asthma medication, blood eosinophil count, serum total IgE, serum eosinophil cationic protein level, and skin prick test result were assessed. RESULTS: The FEV1 (mean+/-SD) values of the 145 patients were 90.5+/-10.9% predicted, 64.2+/-11.5% predicted, and 86.2+/-11.2% predicted before and after methacholine inhalation, and following the administration of a SABA, respectively. The BDR did not differ significantly according to asthma medication, age, or gender. However, BDR in the atopy group (37.4+/-17.7%) was significantly higher than that in the non-atopy group (30.5+/-10.7%; P=0.037). Patients with blood eosinophilia (38.6+/-18.1%) displayed increased BDR compared with patients without eosinophilia (32.0+/-13.8%; P=0.037). CONCLUSIONS: In children with mild to moderate asthma, the responsiveness to short-acting bronchodilators after methacholine-induced bronchoconstriction was not related to asthma medication, but was higher in children with atopy and/or peripheral blood eosinophilia.
Adrenergic beta-Agonists ; Asthma ; Azides ; Bronchoconstriction ; Bronchodilator Agents ; Child ; Eosinophil Cationic Protein ; Eosinophilia ; Eosinophils ; Humans ; Immunoglobulin E ; Inhalation ; Methacholine Chloride ; Serotonin ; Skin

PURPOSE: Extended spectrum beta-lactamases (ESBLs) are cephalosporinases that confer resistance to a wide variety of oxyimino cephalosporins and create serious therapeutic problems. In addition, the quinolone resistance qnr genes are becoming increasingly prevalent in clinical isolates, some of which also produce ESBL. This study was designed to evaluate the occurrence and genotypic distribution of ESBL producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) as well as the prevalence and distribution of qnr genes in ESBL-producing isolates in a tertiary care hospital in Korea. MATERIALS AND METHODS: We tested a total of 111 ESBL-producing isolates of E. coli and K. pneumoniae, which were collected at Kyung Hee Medical Center from November 2006 to June 2008. ESBL production was determined by the Clinical and Laboratory Standards Institute (CLSI) ESBL confirmatory test. The cefotaxime and ceftazidime resistance of the ESBL-producers were transferred to azide-resistant E. coli J53 by conjugation. The presence and identity of ESBL and qnr genes were determined by polymerase chain reaction (PCR) and nucleotide sequencing. RESULTS: The prevalence of ESBLs was 17.7% (297/1,680) of E. coli and 26.5% (240/904) of K. pneumoniae in our hospital during the study periods. Of the 111 collected isolates, 69 isolates were E. coli and 42 isolates were K. pneumoniae. The most prevalent ESBL genotype was CTX-M15. Among the ESBL-producing isolates, 4 E. coli (5.8%) and 17 K. pneumoniae (40.5%) contained qnr genes. qnrB4 was the most frequent type in both E. coli and K. pneumoniae. CONCLUSION: CTX-M15 was the most frequently encountered ESBL. In addition, a high prevalence of qnr genes among ESBL-producing K. pneumoniae was identified in this study.
Azides/pharmacology ; Bacterial Proteins/*metabolism ; Cefotaxime/pharmacology ; Ceftazidime/pharmacology ; Drug Resistance, Multiple, Bacterial/genetics ; Escherichia coli/drug effects/*enzymology ; Escherichia coli Infections/*microbiology ; Escherichia coli Proteins/*metabolism ; Humans ; Klebsiella Infections/*microbiology ; Klebsiella pneumoniae/drug effects/*enzymology ; Korea ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; beta-Lactamases/*metabolism

BACKGROUND: Conventional acid-fast bacilli (AFB) staining cannot differentiate viable from dead cells. Propidium monoazide (PMA) is a photoreactive DNA-binding dye that inhibits PCR amplification by DNA modification. We evaluated whether PMA real-time PCR is suitable for the early detection of viable Mycobacterium tuberculosis (MTB) in clinical respiratory specimens. METHODS: A total of 15 diluted suspensions from 5 clinical MTB isolates were quadruplicated and subjected to PMA treatment and/or heat inactivation. Eighty-three AFB-positive sputum samples were also tested to compare the DeltaC(T) values (C(T) value in PMA-treated sputum samples-C(T) value in non-PMA-treated sputum samples) between culture-positive and culture-negative specimens. Real-time PCR was performed using Anyplex MTB/NTM Real-Time Detection (Seegene, Korea), and the C(T) value changes after PMA treatment were compared between culture-positive and culture-negative groups. RESULTS: In MTB suspensions, the increase in the C(T) value after PMA treatment was significant in dead cells (P=0.0001) but not in live cells (P=0.1070). In 14 culture-negative sputum samples, the median DeltaC(T) value was 5.3 (95% confidence interval [CI], 4.1-8.2; P<0.0001), whereas that in 69 culture-positive sputum samples was 1.1 (95% CI, 0.7-2.0). In the ROC curve analysis, the cutoff DeltaC(T) value for maximum sensitivity (89.9%) and specificity (85.7%) for differentiating dead from live cells was 3.4. CONCLUSIONS: PMA real-time PCR is a useful approach for differentiating dead from live bacilli in AFB smear-positive sputum samples.
Adult ; Aged ; Area Under Curve ; Azides/*chemistry ; DNA, Bacterial/*analysis ; Female ; Humans ; Lung Diseases/diagnosis/*microbiology/pathology ; Male ; Middle Aged ; Mycobacterium tuberculosis/genetics/*isolation & purification ; Pilot Projects ; Propidium/*analogs & derivatives/chemistry ; ROC Curve ; *Real-Time Polymerase Chain Reaction ; Sputum/microbiology ; Tuberculosis/*diagnosis/microbiology

BACKGROUND: Development of thoracic aortic aneurysms and aortic dissections (TAAD) is attributed to unbearable wall tension superimposed on defective aortic wall integrity and impaired aortic repair mechanisms. Central to this repair mechanisms are well-balanced and adequately functional cellular components of the aortic wall, including endothelial cells, smooth muscle cells (SMCs), inflammatory cells, and adventitial fibroblasts. Adventitial fibroblasts naturally produce aortic extracellular matrix (ECM), and, when aortic wall is injured, they can be transformed into SMCs, which in turn are involved in aortic remodeling. We postulated the hypothesis that adventitial fibroblasts in patients with TAAD may have defects in ECM production and SMC transformation. MATERIALS AND METHODS: Adventitial fibroblasts were procured from the adventitial layer of fresh aortic tissues of patients with TAAD (Group I) and of multi-organ donors (Group II), and 4-passage cell culture was performed prior to the experiment. To assess ECM production, cells were treated with TNF-alpha (50 pM) and the expression of MMP-2 / MMP-3 was analyzed using western blot technique. To assess SMC transformation capacity, cells were treated with TGF-beta1 and expression of SM alpha-actin, SM-MHC, Ki-67 and SM calponin was evaluated using western blot technique. Fibroblasts were then treated with TGF-beta1 (10 pM) for up to 10 days with TGF-beta1 supplementation every 2 days, and the proportion of transformed SMC in the cell line was measured using immunofluorescence assay for fibroblast surface antigen every 2 days. RESULTS: MMP-3 expression was significantly lower in group I than in group II. TGF-beta1-stimulated adventitial fibroblasts in group I expressed less SM alpha-actin, SM-MHC, and Ki-67 than in group II. SM-calponin expression was not different between the two groups. Presence of fibroblast was observed on immunofluorescence assay after more than 6 days of TGF-beta1 treatment in group I, while most fibroblasts were transformed to SMC within 4 days in group II. CONCLUSION: ECM production and SMC transformation are compromised in adventitial fibroblasts from patients with TAAD. This result suggests that functional restoration of adventitial fibroblasts could well be a novel approach for the prevention and treatment of TAAD.
Actins ; Aneurysm ; Antigens, Surface ; Aorta ; Aortic Aneurysm, Thoracic ; Azides ; Blotting, Western ; Calcium-Binding Proteins ; Cell Culture Techniques ; Cell Line ; Deoxyglucose ; Endothelial Cells ; Extracellular Matrix ; Fibroblasts ; Fluorescent Antibody Technique ; Humans ; Microfilament Proteins ; Myocytes, Smooth Muscle ; Tissue Donors ; Transforming Growth Factor beta1 ; Tumor Necrosis Factor-alpha

Adult ; Humans ; Male ; Occupational Exposure ; Sodium Azide ; poisoning

The effects of dimethyl sulfoxide (DMSO) were studied in two groups of Xenopus oocytes, one expressing ATP sensitive K+ (KATP) channel comprised of sulfonylurea receptor SUR1 and inwardly rectifying K+ channel subunit Kir6.2, and the other expressing renal KATP channel ROMK2. At concentrations of 0.3~10% (vol/vol) DMSO inhibited whole cell Kir6.2/SUR1 currents elicited by bath application of sodium azide (3 mM) in a concentration-dependent manner. The inhibition constant and Hill coefficient were 2.93% and 1.62, respectively. ROMK2 currents, however, was not affected significantly by DMSO. The results support the idea that DMSO inhibits KATP channel expressed in Xenopus oocyte through a protein-specific mechanism(s) that remains to be further elucidated.
Adenosine Triphosphate ; Baths ; Dimethyl Sulfoxide* ; Oocytes* ; Sodium Azide ; Xenopus*