A method for determining volatile organic compounds (VOCs) emitted from medical molecular sieve oxygen concentrators was developed using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The oxygen concentrator gas was sampled at a flow rate of 0.5 L/min through a branched sampling system onto Tenax GR/carbopack B adsorption tubes. The adsorbed compounds were desorbed and introduced using a programmed temperature vaporization inlet system, followed by chromatographic separation on an SH-I-624Sil MS column. Four VOCs (BHT-Q, PTBP, BHT-quinol, and EHB) were detected in the medical oxygen concentrator using this method. Calibration curves for these compounds exhibited excellent linearity ( R ²>0.99) within the range of 3~100 ng. With a sampling volume of 20 L, the detection limit of the four VOCs ranged from 0.003 9 to 0.022 2 μg/m ³. Spike recovery rates for the four VOCs were between 95% and 115%, with relative standard deviations (RSDs) below 5% ( n=6). The method is simple, rapid, highly sensitive, and accurate, making it suitable for VOCs detection in medical molecular sieve oxygen concentrators.
Volatile Organic Compounds/analysis* ; Gas Chromatography-Mass Spectrometry/methods* ; Oxygen

Wave intensity (WI) is a newly proposed hemodynamic index that assesses the working condition of cardiovascular system. The purpose of this study is to investigate the clinical value of WI in assessing the function of cardiovascular system in patients with chronic heart failure (CHF). We used a combined Doppler and echo-tracking system to calculate the carotid artery WI in 16 patients with CHF and 35 normal subjects, and examined the characteristics of WI. The main WI indices included W1, W2, NA, R-W1 and W1-W2. Compared with those in the control group, W1 and W2 were significantly decreased in CHF group (5.44 +/- 3.24 vs. 10.05 +/- 46.33, P < 0.01, 0.83 +/- 0.42 vs. 1.50 +/- 0.95, P < 0.01, respectively), the temporal indices R-W1 shortened (141.06 +/- 41.14 vs. 109.77 +/- 22.50, P < 0.05) and W1-W2 prolonged (214.63 +/- 39.93 vs. 260.51 +/- 20.58, P < 0.01), and the (R-W1)/(W1-W2) ratio was significantly larger in CHF group (0.69 +/- 0.26 vs. 0.43 +/- 0.10, P < 0.01). WI provides a great deal of information about the dynamic behavior of the interaction between the heart and vascular system, so it is a new quantitative approach for analysis of CHF.
Adult ; Aged ; Blood Flow Velocity ; Blood Pressure ; Carotid Arteries ; diagnostic imaging ; physiopathology ; Chronic Disease ; Echocardiography, Doppler, Color ; Female ; Heart Failure ; diagnostic imaging ; physiopathology ; Hemodynamics ; physiology ; Humans ; Male ; Middle Aged

Objective To examine the effects of a peroxisome proliferator-activated receptor γ ligand troglitazone on the proliferation and differentiation of HepG2 cells. Methods After the pretreatment of HepG2 cells with troglitazone, MTT and flow cytometry were used to analyze the proliferation and cell cycle of HepG2 cells, respectively. Immunocytochemistry, bromocresol green dye-binding method and chemiluminessence immunosorbent assay was used to determine E-cadherin, albumin and AFP, respectively. The expression of cyclin D1 and c-myc protein were detected by Western blot. Results Troglitazone inhibited the proliferation of HepG2 cells in a concentration-dependent manner and arrested HepG2 ceils at the G0>/G1> phase. After pretreated with troglitazone, HepG2 cells showed E-cadherin expression, a decreased expression of cyclin D1 and c-myc protein, a reduction of AFP level and a dramatic increase of albumin level. Conclusions Troglitazone inhibits proliferation and induces differentiation of HepG2 cells, the mechanism of which might be attributable to the down-regulation of cyclin D1 and c-myc expression.

OBJECTIVETo investigate the killing effect of herpes simplex virus thymidine kinase gene expression actuated by the promoter of the vascular endothelial growth factor gene on human hepatocellular tumor cells under hypoxic condition.

METHODSRecombinant adenoviral vectors, AdVEGF-tk and AdVEGF-GFP, were constructed with HSV-tk or GFP under the control of VEGF promoter through AdEasy system. Then GFP expression in hepatoma cell line HepG2 and normal liver cell line L02 transfected with AdVEGF-GFP were observed under fluorescence microscope, and the sensitivity to GCV of the AdVEGF-tk-transfected cells under normoxia or hypoxia condition were monitored by MTT method.

RESULTSGFP expression actuated by VEGF promoter was detected in sporadic L02 cells, but in almost all HepG2 cells after transfected with AdVEGF-GFP. With GCV at 10 micro g/ml and MOI at 100, L02 cells were insensitive to GCV under oxic condition, but more than 70% L02 cells were killed under hypoxic condition. Moreover, HepG2 cells infected with AdVEGF-tk showed the increased GCV sensitivity under hypoxia (over 80% killed) as compared with normoxia (over 60% killed) conditions.

CONCLUSIONHypoxia enhances the GCV sensitivity of human hepatocellular tumor cells infected with recombinant AdVEGF-tk under the control of VEGF promoter.

Adenoviridae ; genetics ; Carcinoma, Hepatocellular ; pathology ; Endothelial Growth Factors ; genetics ; Gene Expression ; drug effects ; Gene Transfer Techniques ; Genetic Vectors ; genetics ; Humans ; Hypoxia ; Intercellular Signaling Peptides and Proteins ; genetics ; Liver Neoplasms ; pathology ; Lymphokines ; genetics ; Oxygen ; pharmacology ; Promoter Regions, Genetic ; physiology ; Simplexvirus ; enzymology ; Thymidine Kinase ; genetics ; metabolism ; Tumor Cells, Cultured ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

OBJECTIVETo investigate the correlation between midkine (MK) protein expression with local infiltration and metastasis in human hepatocellular carcinoma (HCC).

METHODSImmunohistochemical and Western Blot analysis for MK were performed on samples of tumor tissue and the paratumor tissue from HCC and benign liver tumors.

RESULTSThe overexpression of MK protein determined by immunohistochemical analysis was similar to that by Western Blot analysis. No specific positivity was detected in either benign liver tumor tissue or normal liver tissue, but most of HCC tissue showed a positive reaction to MK immunostain. No correlation between MK expression and other clinicopathological features in MK negative or positive HCC cases was found. Yet, the overexpression rate of MK protein in HCC with intra-hepatic metastasis was significantly higher than that in HCC without intra-hepatic metastasis.

CONCLUSIONIn human hepatocellular carcinoma, MK overexpressed at protein level may very well be closely related to local infiltration and metastasis.

Blotting, Western ; Carcinoma, Hepatocellular ; metabolism ; secondary ; Carrier Proteins ; biosynthesis ; metabolism ; Cytokines ; Humans ; Immunohistochemistry ; Liver Neoplasms ; metabolism ; pathology ; Neoplasm Metastasis

0.05). The mean growth values in AdCMV-tk/GCV- and AdVEGF-tk/GCV-treated tumors were significantly lower than those in untreated tumors and AdVEGF-tk/saline-untreated tumors( P

The leaves of Scindapsus aureum were frozen at\|19℃ for 5 mins after sprayed with 91?g/mL Ampicillin and 91?g/mL streptomycin sulfate mixture solution,After 15 days the results showed that frozen spot number of the leaves treated with water reduced by 75% compared with those of CK,but thethickness unchanged.The frozen spots began with the border of the leaves.The frozen spots of the group treated with antibiotic mixture solution didn't appear until 5 mins later,and the number of the frozen spots reduced by 95% after 8 mins of freezing.They covered the border of the leaves.This indicated that the antibiotic mixture solulion can obviously reduce the freeze injury to the leaves.