Objective To study the effect of hyperoxia solution and hypertonic saline infusion on arteries blood gas analysis of traumatic hemorrhagic shock rabbits,and interaction of hyperoxia solution and hypertonic saline.Methods Forty rabbits established into traumatic hemorrhagic shock model by Lamson' s method.Post hoc analysis was adopted in trial according to hyperoxia solution and hypertonic saline and 40 rabbits were divided into four groups(n =10):saline(NS) group,normal hyperoxic solution (NSO) group,hypertonic saline(HS) group,hyperosmotic-hyperoxic solution(HSO) group.Then blood samples were collected at pre-shock,post-shock,the end of limited resuscitation and hemostatic resuscitation for blood gas analysis.Results At the pre-shock,post-shock stages,PaCO2 and PaO2 were no significant difference in each groups ( P ＞0.05 ).At the end of limited resuscitation and hemostatic resuscitation stage,PaCO2 in NSO group (33.50 ±5.93),(37.22 ±6.74) mm Hg,(31.70 ±7.39),(35.10 ±7.56 )mm Hg in HS group,HSO group(38.70 ±4.92),(41.80 ± 5.51 )mm Hg were higher than that in NS group ( 27.40 ± 3.60 ),( 30.83 ± 2.79 ) mm Hg (F =6.894,4.287,respectively ;P ＜ 0.05 ),but there were no cross correlation between hypertonic saline and hyperoxia solution ( P ＞ 0.05).There were no significant difference in PaO2 in each groups at the end of limited resuscitation and hemostatic resuscitation stage ( P ＞ 0.05 ).Conclusions Both hyperoxia solution and hypertonic saline can effectively relieve hyperventilation,but there is no interaction between them.

A method was established for the determination of chlorpyrifos metabolites employing QuEChERS method and ultra performance liquid chromatography-triple quadrupole-linear ion trap mass spectrometry (UPLC-QTRAP). The urine samples were extracted by acetonitrile and then cleaned up with PSA and GCB. The samples were separated with the gradient elution of acetonitrile-0.2% ammonia water on ZORBAX Eclipse Plus C18column. The analytes were detected by tandem mass spectrometry under negative ion mode with electrospray ionization (ESI) source and MRM-IDA-EPI mode. Under the optimized conditions, the calibration curve was linear in range of 1.0-100.0 μg/L,and the limits of detection were 0.10-0.73 μg/L. The average recoveries were 80.3%-90.1%, and RSDs were all within 10%. The developed method was simple,sensitive,accurate,and repeatable,and could avoid false positive result of samples effectively. The established method was successfully applied to determine the exposure level of chlorpyrifos metabolites in real samples of human health risk analysis. The results showed that the maximum concentration of chlorpyrifos metabolites was 54.6 μg/L. This method provided technic support for simultaneous identification and quantification of chemicals in complex matrix.

OBJECTIVETo investigate the effects of arsenic trioxide (As(2)O(3)) on the apoptosis and P-glyco-protein (P-gp) expression of multidrug-resistant human leukemia K562/ADM cells, and the combined effects of As(2)O(3) with conventional chemotherapeutic agents.

METHODSMultidrug-resistant human leukemia cell line K562/ADM that overexpresses mdr-1 gene was used as the target cells. The cell proliferating activity was assessed with a MTT assay. Cell morphology was examined by light microscopy, confocal microscopy and electron-microscopy. P-gp expression, cell-cycle status were determined by flow cytometry.

RESULTSK562/ADM cells were highly resistant to adriamycin, and cross-resistant to daunorubicin and etoposide. As(2)O(3) at concentrations of 0.5 to 20 micromol/L inhibited the proliferation of K562/ADM cells, and K562/ADM cells were more sensitive to As(2)O(3) than their parent K562 cells did. As(2)O(3) induced marked apoptosis of K562/ADM cells showed by typical apoptotic morphological changes and the appearance of high sub-G(1) cell population. As(2)O(3) significantly inhibited the P-gp expression in K562/ADM cells, and exerted a synergistic effect on the enhancement of the cell sensitivity to adriamycin, daunorubicin and etoposide.

CONCLUSIONAs(2)O(3) induces growth-inhibition and apoptosis of multidrug-resistant K562/ADM cells, and augments synergistically the sensitivity of the cells to conventional chemotherapeutic agents via down-regulation of P-gp expression.

ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; drug effects ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Daunorubicin ; pharmacology ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Drug Synergism ; Etoposide ; pharmacology ; Humans ; K562 Cells ; Oxides ; pharmacology

Objective To understand the distribution and changes in antimicrobial resistance of clinically isolated Pseudomonas aeruginosa(P.aeruginosa)in the member hospitals of Hunan Provincial Antimicrobial Resistance Surveillance System from 2012 to 2021.Methods Antimicrobial susceptibility testing by disk diffusion or automa-ted instrument was performed on clinical isolates.Testing results were determined according to the standards of 2022 edition from American Clinical Laboratory Standards Institute(CLSI).Statistical analysis was performed by WHONET 5.6 software.Data were analyzed by trend test(Cochran-armitage)and Chi-square test with SPSS.Results A total of 176 441 strains of P.aeruginosa were surveilled by Hunan Provincial Antimicrobial Resistance Surveillance System from 2012 to 2021.99.4％of the strains were isolated from hospitalized patients,and about 70％of the strains were isolated from respiratory specimens.8.4％of P.aeruginosa were from children(0-17 years old),91.6％were from adults.Antimicrobial susceptibility testing results showed that P.aeruginosa was most sensitive to polymyxin B over 10 years,with a resis-tance rate of less than 6％.Resistance rates to piperacil-lin,piperacillin/tazobactam,ceftazidime,cefepime,aztreonam,imipenem,amikacin,gentamicin,tobramycin,cip-rofloxacin,levofloxacin,and polymyxin B all showed downward trends.A total of 29 920 carbapenem-resistant P.aeruginosa(CRPA)strains were detected.The average isolation rate of CRPA in this province was 18.0％over 10 years.CRPA detection rate from adult was 18.5％,higher than that from children(12.3％),and both showing downward trends.Conclusion The resistance rate of clinically isolated P.aeruginosa in Hunan Province to most commonly used antimicrobial agents is decreasing.

Objective:To investigate the effects of naringenin on oxidative stress and Tau protein phosphorylation of adrenal pheochromocytoma（PC12） cells injured by β-amyloid（Aβ）_25-35 and its relationship with estrogen receptor（ER） and phosphatidylinositol -3 kinase/protein kinase B（PI3K/Akt） signaling pathway. Method:The PC12 cells were intervened with Aβ_25-35 to prepare the injury model. The experiment was divided into blank group， model group， naringenin（400，40，4，0.4，0.04，4×10^-3，4×10^-4，4×10^-5 μmol·L^-1）group， positive drugs estradiol（E₂）（1 nmol·L^-1）+Aβ_25-35 group， naringenin（0.4，0.04，4×10^-3，4×10^-4，4×10^-5 μmol·L^-1）+Aβ_25-35 group， E₂+Aβ_25-35+ER antagonist（ICI182780）（1 μmol·L^-1） group， naringenin+Aβ_25-35+ICI182780 group， E₂+Aβ_25-35+PI3K blocker（LY294002）（50 μmol·L^-1） group， naringenin+Aβ_25-35+LY294002 group. Methye thiazolye telrazlium（MTT）method was used to detect the cell proliferation index， 2'，7'-Dichlorodi -hydrofluorescein diacetate（DCFH-DA） was used as a fluorescent probe to detect the content of reactive osygen species（ROS）， the content of malondialdehyde（MDA） and the activity of superoxide dismutase（SOD） were measured by thiobarbituric acid（TBA） and oxidase methods， Western blot was used to detect the expression of phosphorylated Tau protein/total Tau protein（p-Tau/t-Tau）. Result:According to the results of MTT experiment， 0.4 μmol·L^-1 was selected as the best effective concentration of naringenin， compared with the blank group， the cell proliferation index of model group decreased significantly （P<0.01）， compared with model group， the cell proliferation index of naringenin+Aβ_25-35 group increased significantly （P<0.01）. In addition， compared with blank group， the content of ROS， MDA and the expression of p-Tau/t-Tau in the model group increased significantly （P<0.01）， and the activity of SOD decreased significantly （P<0.01）， compared with model group， the content of ROS， MDA and the expression of p-Tau/t-Tau in naringenin+Aβ_25-35 group decreased significantly （P<0.01）， and the activity of SOD increased significantly （P<0.01）， compared with naringenin+Aβ_25-35 group， the addition of ICI182780 and LY294002 significantly reversed the role of naringenin in the above indicators （P<0.01）. The effect of naringenin was similar to that of E₂. Conclusion:Naringenin can improve the cell proliferation index and protect PC12 cells from Aβ_25-35 injury， which may be achieved by activating ER and PI3K/Akt signaling pathway to reduce ROS， MDA content， p-Tau/t-Tau expression and promote SOD activity.