Nosocomial bloodstream infection pathogen Pantoea dispersa: a case report and literature review.

Pantoea dispersa is a Gram-negative bacterium frequently found in plants, soil, and water. The genus Pantoea is a rare pathogen in human infectious diseases. The known susceptible populations include infants and postoperative and immunocompromised patients. To date, there have been no reports of nosocomial bloodstream infection due to P. dispersa following chest puncture. A 72-year-old Chinese woman suffering from chest distress was found to be blood culture positive for a Gram-negative bacterium. The organism was identified as P. dispersa through Vitek 2, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and 16S rRNA gene sequencing. Although cefoperazone-sulbactam and imipenem were used for treatment, the patient died four days later. To the best of our knowledge, this is the first case of nosocomial bloodstream infection caused by P. dispersa in China. We hope that this article might help clinicians understand better the potential pathogenicity of this pathogen.

[Application of a new solid adsorbent tube for the determination of three kinds of epoxy eompounds in air].

Objective: To develop a new solid sorbent tube for simultaneously capturing ethylene oxide (EO) , propylene oxide (PO) and epichlorohydrin (ECH) in air, and establish a complete set of method. Methods: In June 2018, EO, PO and ECH in air were captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 5% (V/V) methanol-methylene chloride, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of EO, PO and ECH were 0.24-960.00, 0.60-2384.00 and 0.12-472.40 mg/L respectively, and the related coefficients were between 0.99995-0.99997. The relative standard deviations (RSD) within the group were 1.66%-4.09%, 1.36%-4.43%, and 1.99%-5.65%, respectively, and the RSD between the group were 2.69%-4.95%, 2.77%-5.30%, and 3.27%-6.67%, respectively. The average desorption efficiencies were 88.25%-94.50%, 98.17%-98.60%, and 97.79%-101.04%, respectively. The samples could be stored at 4 ℃ refrigerator for at least 27 days. Conclusion: The newly developed solid sorbent tube filled with carbon aerogel adsorbent and its complete set of gas chromatography method could be used for sampling and quantitative detection of EO, PO and ECH in workplace air.

[Study on the Specific Complexation of GMDTC and Metal Ion].

Objective: Study the response of GMDTC to cadmium ions and metal ions in vivo to determine whether GMDTC are specifically complexed with cadmium ions to provide a reference for the safety and dfficacy of GMDTC. Methods: Complexometric titration, HPLC and HPLC-MS were applied to research the complexation reaction of GMDTC and various metal ions. The molecular ion peak of GMDTC, GMDTC-Cd complex and GMDTC-Pb complex also detected by LC-MS. Additionally, the initial structure was determined by DFT simulation method. Results: Results of complexometric titration and HPLC detection showed that GMDTC characteristic absorption peak area was proportional to the concentration of itself and there was no color change and peak time change when the GMDTC mixed with Ca(2+), Fe(2+), Mg(2+), Zn(2+). However, the color changed to black transition when the GMDTC mixed with Cu(2+) and the color changed from yellow precipitate to light yellow transparent transition when GMDTC mix with Hg(2+). Moreover, the peak area as well as the retention time has changed a lot which indicated that a chemical reaction has already happened. When the GMDTC mixed with Cd(2+) and Pb(2+), the color has changed from pale yellow to colorless transparent and the peak area of GMDTC has increased a lot. Finally, the GMDTC-Cd complex ratio both of which are 2:1 were calculated based on the results of LC-MS instrument and atomic calculations. Conclusion: The specific cadmium chelating agent GMDTC can not react with the Ca(2+), Fe(2+), Mg(2+), Zn(2+), but it can react chemically with Cu(2+) and Hg(2+), even specific complex with Pb(2+) and Cd(2+).

[Determination of glycidyl methacrylate in the air of workplace captured adsorbent tube by gas chromatography].

Objective: To develop a new solid sorbent tube for capturing glycidyl methacrylate (GMA) in workplace air, and establish a complete set of method. Methods: GMA in workplace air was captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 50% (V/V) dimethylformamide-carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear range of GMA was 0.38-604.80 mg/L, and the related coefficient was 0.999 82. The within-run and the between-run precision were 1.11%-2.80% and 2.53%-4.84% respectively. The average desorption efficiency was 93.20%-94.97%. The minimum quantification concentration and The minimum quantification concentration were 0.02 and 0.07 mg/m(3) respectively (3.00 L sample) . Samples could be stored for at least 8 days at room temperature. Conclusion: The newly developed solid sorbent tube and its complete set of gas chromatography method is simple, and has high sensitivity and precision, so it can be used for sampling and quantitative detection of GMA in workplace air.

[Determination of hippuric acid and methylhippuric acid in urine by high performance liquid chromatography after extracted with acetonitrile].

OBJECTIVE: To establish pretreatment conditions of hippuric acid (HA)and methyl-hippuric acid (MHA)in urine and HPLC conditions. METHODS: HA and MHA in urine were extracted with acetonitrile under acid condition and determinated by HPLC-DAD. The operating conditions by HPLC were C18 column (150 mm× 4.6 mm, 5 µm), methanol-0.2% acetic acid (contained 6.5 mmol/L potassium dihydrogen phosphate)(25∶75, V/V) as mobile phase,1 ml/min as flow rate and wavelength was at 254 nm. RESULTS: The standard curves for HA, 2-MHA and 3-MHA(4-MHA)showed good linearity between 9.91~2 974.20 µg/ml(r=0.999 98), 1.91~573.60 µg/ml (r=0.999 84)and 2.00~598.65 µg/ml (r=0.999 85), respectively. The mean recoveries were 96.38%~98.01%, 83.17%~94.05 %, 103.22%~104.45%, respectively. The within-run precision were 0.50%~1.20%, 0.51%~1.59%, 0.49%~0.95%, respectively, and the between-run precision were 1.70%~3.20%, 1.30%~2.67%, 0.86%~2.74%, respectively. The detection limit of HA, 2-MHA and 3-MHA(4-MHA)were 0.18 µg/ml, 0.46 µg/ml and 0.12 µg/ml, and the low determination concentrations of the method were 0.36 µg/ml, 0.92 µg/ml and 0.24 µg/ml(1 ml urine). The urine can be kept 15 days at 4 ℃ refrigerator without significantly loss. CONCLUSION: This method with simply pretreatment conforms to the relevant requirements of guide for establishing occupational health standards-part 5: determination methods of chemicals in biological materials. It can be used to detect HA and MHA in urine for occupational population exposure to toluene and xylene.

Activation of Galpha s mediates induction of tissue-type plasminogen activator gene transcription by epoxyeicosatrienoic acids.

The epoxyeicosatrienoic acids (EETs) are products of cytochrome P450 (CYP) epoxygenases that have vasodilatory and anti-inflammatory properties. Here we report that EETs have additional fibrinolytic properties. In vascular endothelial cells, physiological concentrations of EETs, particularly 11,12-EET, or overexpression of the endothelial epoxygenase, CYP2J2, increased tissue plasminogen activator (t-PA) expression by 2.5-fold without affecting plasminogen activator inhibitor-1 expression. This increase in t-PA expression correlated with a 4-fold induction in t-PA gene transcription and a 3-fold increase in t-PA fibrinolytic activity and was blocked by the CYP inhibitor, SKF525A, but not by the calcium-activated potassium channel blocker, charybdotoxin, indicating a mechanism that does not involve endothelial cell hyperpolarization. The t-PA promoter is cAMP-responsive, and induction of t-PA gene transcription by EETs correlated with increases in intracellular cAMP levels and, functionally, with cAMP-driven promoter activity. To determine whether increases in intracellular cAMP levels were due to modulation of guanine nucleotide-binding proteins, we assessed the effects of EETs on Galpha(s) and Galpha(i2). Treatment with EETs increased Galpha(s), but not Galpha(i2), GTP-binding activity by 3.5-fold. These findings indicate that EETs possess fibrinolytic properties through the induction of t-PA and suggest that endothelial CYP2J2 may play an important role in regulating vascular hemostasis.

Activation of guanine nucleotide-binding proteins and induction of endothelial tissue-type plasminogen activator gene transcription by alcohol.

The mechanism by which moderate alcohol ingestion lowers the risk of cardiovascular disease is unknown but may be due, in part, to the ability of alcohol to increase the level of tissue-type plasminogen activator (t-PA). Human endothelial cells were treated with low concentrations of ethanol (0.25-25 mM, 0-24 h), which are associated with moderate alcohol consumption. Although treatment with ethanol alone did not affect t-PA gene transcription or mRNA expression, it augmented isoproterenol (ISO)-stimulated t-PA gene transcription and mRNA levels by 3.4- and 2.8-fold, respectively, and decreased plasminogen activator inhibitor-1 mRNA levels by 65%. These effects of ethanol correlated with 2.5- and 6.9-fold increases in ISO-stimulated cyclic AMP levels and 4x-cyclic AMP response element heterologous promoter activity, respectively. To determine whether alcohol-induced changes in agonist-stimulated cyclic AMP levels were because of modulation of guanine nucleotide-binding proteins (G proteins), we assessed the effects of ethanol on Galphas and Galphai2. Although ethanol did not affect the expression of Galphas or Galphai2, it increased ISO-stimulated Galphas GTPase and GTP binding activity by 2.2- and 2.9-fold and decreased UK14304-stimulated Galphai2 GTPase and GTP binding activity by 38 and 80%. These results indicate that treatment with relatively low concentrations of ethanol enhances agonist-stimulated cyclic AMP-dependent t-PA gene transcription in vascular endothelial cells through differential modulation of G protein.