Research progress on detection methods for nitrobenzene compounds in air / 中国职业医学

@#Abstract: Nitrobenzene compounds (NBCs) are widely used in the world. It has 40 isomers such as nitrobenzene, dinitrobenzene and nitrotoluene, that are highly toxic and difficult to degrade and can cause harm to human health in different degrees. At pres⁃ ent, there is no unified standard method and occupational exposure limit for the detection of NBCs in the air. In terms of sampling medium, solid adsorption tube is mostly used for trapping vapor state NBCs, and filter membrane and solid adsorption tube are mostly used in series for sampling coexist NBCs in vapor state and aerosol state. In the detection methods, gas chromatography and liquid chromatography are common, and ultraviolet spectrophotometry, Raman spectroscopy, ion migration spectrometry and some other rapid response methods and technologies are also used in the detection of NBCs. In the detection of NBCs by gas chro⁃ matography, capillary column separation is commonly used, and the main detectors are flame ionization detector, electron capture detector and mass spectrometry detector. It is of practical significance to establish a method with high sensitivity, strong practica⁃ bility, convenient operation, and can simultaneously collect and detect a variety of NBCs in different states.

Determination of dimethyl sulfate in workplace air by pre-column derivatization-high performance liquid chromatography / 中国职业医学

@#Abstract: Objective - - To establish a pre column derivatization high performance liquid chromatography method for detecting Methods dimethyl sulfate (DMS) in workplace air. DMS in workplace air was collected with mercaptopyridine impregnated （ silicone tube. The derivative of DMS and mercaptopyridine was eluted by mobile phase phase A: water, phase B: acetonitrile, ∶ the volume ratio was 40 60) , and separated with a C18 column, then detected with diode array detector and quantitated by a Results - standard curve. The linear range of DMS was 0.17 40.00 mg/L, with the correlation coefficient of 0.999 95. The detection limit and the lower limit of quantitation were 0.05 and 0.17 mg/L respectively. The minimum detection concentration and minimum quantitation concentration were 0.02 and 0.04 mg/m³, respectively (air sample volume of 4.5 L, 1.0 mL sample - - - solution). The average desorption efficiency was 98.40% 102.00%. The within run and between run relative standard deviations - - were 0.61% 3.92% and 1.71% 6.00%, respectively. The samples could be stored at room temperature for at least 14 days. Conclusion This method can be used to detect DMS in workplace air.

Chloro-nitrobenzene compounds air sampling tube preparation and determination method / 中国职业医学

@#Objective - - To prepare the GDH 5 air sampling tube for simultaneous collection of eight kinds of chloro nitrobenzene （ ） ， compounds CNBs in the air of workplace and establish a matching determination method using gas chromatography. Methods - - ， Eight kinds of CNBs in vapor and aerosol state were collected by self developed GDH 5 air sampling tube desorbed ， ， ， by toluene separated by polysiloxane gas chromatography column detected by microcell electron capture detector and Results - （ - quantified by external standard method. It was determined that the air sampling tube was assembled by XAD 2 ion ） - ， exchange resin and glass fiber filter membrane. The linear range of CNBs was 0.80 240.00 mg/L and the linear correlation - - coefficients were greater than 0.999 9. The detection limit was 7.87 13.03 μg/L. The minimum detectable concentration was 0.60 3， - 3（ ） 1.33 μg/m and the minimum quantitative concentration was 2.00 4.22 μg/m sample 45.00 L . The average desorption - - （RSD） - ， - RSD efficiency was 101.2% 110.0%. The within run relative standard deviation was 0.8% 4.1% and the between run - Conclusion - was 0.3% 5.8%. The samples could be stored for more than 30 days at room temperature. GDH 5 air sampling tube and its associated determination method can be used for the collection and determination of eight kinds of CNBs in workplace air.

Involvement of endothelial CK2 in the radiation induced perivascular resistant niche (PVRN) and the induction of radioresistance for non-small cell lung cancer (NSCLC) cells

BACKGROUND: Tumor microenvironment (TME) plays a vital role in determining the outcomes of radiotherapy. As an important component of TME, vascular endothelial cells are involved in the perivascular resistance niche (PVRN), which is formed by inflammation or cytokine production induced by ionizing radiation (IR). Protein kinase CK2 is a constitutively active serine/threonine kinase which plays a vital role in cell proliferation and inflammation. In this study, we investigated the potential role of CK2 in PVRN after IR exposure. RESULT: Specific CK2 inhibitors, Quinalizarin and CX-4945, were employed to effectively suppressed the kinase activity of CK2 in human umbilical vein endothelial cells (HUVECs) without affecting their viability. Results showing that conditioned medium from IR-exposed HUVECs increased cell viability of A549 and H460 cells, and the pretreatment of CK2 inhibitors slowed down such increment. The secretion of IL-8 and IL-6 in HUVECs was induced after exposure with IR, but significantly inhibited by the addition of CK2 inhibitors. Furthermore, IR exposure elevated the nuclear phosphorylated factor-κB (NF-κB) p65 expression in HUVECs, which was a master factor regulating cytokine production. But when pretreated with CK2 inhibitors, such elevation was significantly suppressed. CONCLUSION: This study indicated that protein kinase CK2 is involved in the key process of the IR induced perivascular resistant niche, namely cytokine production, by endothelial cells, which finally led to radioresistance of non-small cell lung cancer cells. Thus, the inhibition of CK2 may be a promising way to improve the outcomes of radiation in nonsmall cell lung cancer cells.

Progress of galectin-3 and atrial fibrillation / 天津医药

Atrial fibrillation (AF) is the most common tachyarrhythmia in clinical practice. Owing to its high morbidity and mortality, early diagnosis of AF plays an important clinical significance in treatment and prognosis. Galectin-3 (Gal-3), as a sensitive marker of inflammatory and oxidative stress found in recent years, is involved in the occurrence and development of myocardial inflammation and fibrosis, which is closely related to atrial remodeling. Gal-3 inhibitor may decrease the risk of AF by reversing myocardial remodeling, which may provide a new theoretical basis and research direction for the upstream treatment of AF.

Effects of dexamethasone on NF-κB activity in lung tissue of rabbits with seawater drowning-induced acute lung injury / 第二军医大学学报

Objective: To explore the changes of nuclear factor-κB (NF-κB) activity, TNF-α, IL-1β and IL-10 contents in the lung tissue of rabbit with seawater drowning-induced acute lung injury (SWD-ALI) and the effects of dexamethasone on the changes. Methods: Forty-two New Zealand white rabbits were randomly allocated to control group (C group, n=18) , seawater drowning group (S group, n=12) and dexamethasone treatment group (D group, n= 12). The drowning model was established by instilling seawater (2 ml/kg body weight) into the endotracheal catheter of animals, then the rabbits received arterial injection of dexamethasone (D group, 1 mg/kg body weight) or 2 ml normal saline (S group). Blood gas analysis was done at predefined time points. The lung wet to dry weight ratio (W/D) and lung permeability index (LPI) were calculated. The activity of NF-κB was analyzed by non-radioactive electrophoretic mobility shift assay (EMSA). The contents of TNF-α, IL-1β and IL-10 were detected by ELISA. Meanwhile, the pathology changes of lung tissues were detected by H-E staining, and the semi-quantitative lung pathologic scores (LPS) was also calculated. Results: The lung of rabbits in S group was obviously enlarged and had more severe edema and congestion compared with C group; furthermore, histopathologic findings indicated inflammatory cell infiltration and other pathologic signs of ALI; the oxygenation index (PaO 2/FiO2) reached the bottom at 0.5 h and did not elevate to more than 300 mmHg(1 mmHg=0.133 kPa) until 6 h. The largest W/D ratio appeared at 3 h after seawater drowning, and the highest LPI and LPS appeared at 6 h; and NF-κB activity and the contents of TNF-α, IL-1β and IL-10 in lung tissues were significantly higher in S group than in C group(P<0.05, P<0.01). The pathological changes of lung in the rabbits of D group were improved compared with S group but worse than those of group C. The W/D ratio, lung permeability index, and lung pathological score in D group were lower than those of the S group; and the oxygenation index was greatly improved 6 h after seawater drowning. NF-κB activity and the contents of TNF-α, IL-1β and IL-10 in lung tissues were significantly lower than those of the S group(P<0.05, P<0.01). Conclusion: Dexamethasone can inhibit the activity of NF-κB and the expression of TNF-α, IL-1β and IL-10 in the lung tissue of rabbits with SWD-ALI and relieve the inflammatory responses and pathological changes.

Relationship between P53 and survivin in human lung cancer cells / 中国肿瘤生物治疗杂志

Objective:To observe the inhibitory effects of survivin-specific siRNA on human lung cancer cell lines with different P53 statuses,and to analyse the relationship between P53 and survivin in vitro.Methods:A549(wild-type P53)and H1299(P53 absent)cells were transfected with chemosynthetic survivin siRNA.The effect of siRNA on cell proliferation was analysed by MTT assay.The changes of cell cycle and apoptosis were examined by flow cytometry.The expression of survivin mRNA was detected by RT-PCR.The protein expression of survivin,P53,P21 and PARP was examined by Western blotting.Results:Endogenous survivin level in A549 cells was lower than that in H1299 cells.The mRNA and protein expression of survivin was significantly lower in siRNA group than in blank control group and non-silencing siRNA group(P

Dynamic changes in apoptosis of polymorphonuclear neutrophil in rabbit with acute lung injury induced by seawater drowning / 解放军医学杂志

Objective To explore the dynamic changes in apoptosis of polymorphonuclear neutrophil (PMN) during the course of seawater drowning-induced acute lung injury (SWD-ALI), and the possible roles of cytokines in the process. Methods Thirty-six NZ rabbits were randomly divided into 6 groups by using a random number table: control group (0h, as baseline value) and 5 seawater drowning groups (S1h, S3h, S6h, S12h and S24h). Blood gas analysis and hemogram were observed at different time points. The ratio of wet to dry lung weight (W/D) and lung permeability index (LPI) were calculated. The changes in PMN apoptosis were analyzed by flow cytometer. The concentrations of tumor necrosis factor alpha (TNF-?), interleukin-1 (IL-1 ) and IL-10 in serum were detected by ELISA. Meanwhile, the pathological changes in lung tissue were examined with hematoxylin-eosin (HE) staining, and lung pathologic scores (LPS) were evaluated. Results The W/D ratio reached its peak value at 3h, while LPI at 6h. The histopathologic findings indicated that inflammatory cell infiltration was most massive at 6～12h. LPS increased at 1h, significantly higher than that of control group (P0.05). Conclusions The apoptosis of PMN, the main inflammatory effector cells, is significantly inhibited in the early stage of SWD-ALI. The serum cytokines, TNF-?, IL-1 and IL-10, play important roles in the pathogenesis of SWD-ALI, but have no evident effects on the inhibition of PMN apoptosis.

Growth-inhibiting effects of paclitaxel combined with survivin-specific siRNA on human lung cancer cell lines / 解放军医学杂志

Objective To assess the effects of survivin-specific siRNA on chemosensitivity of lung cancer cell A549 to paclitaxel in vitro.Methods For determining if survivin-specific siRNA could enhance the responsiveness of lung cancer to paclitaxel,human lung adenocarcinoma cell lines A549(p53 wild-type)were divided into four different treatment groups:control,survivin siRNA,paclitaxel and survivin siRNA+paclitaxel.The effects on cell proliferation,cell cycle and apoptosis were analyzed by MTT assay and flow cytometry,respectively.The protein expression levels of survivin,p21 and PARP were evaluated by Western blot experiments.Results Survivin-specific siRNA showed a augmenting effect on the chemosensitivity of different concentrations of paclitaxel(P

Inhibition of human lung adenocarcinoma A549 cells by silencing survivin gene with RNAi / 解放军医学杂志

0.05).The mRNA and protein expressions of survivin in cells transfected by 100-200nmol/L siRNA were significantly lower than those of untransfected cells(P0.05).Conclusion Silencing survivin gene by the RNAi technique can decrease effectively the expressions of survivin gene and protein,suppress significantly the growth and proliferation of A549 cells,and induce apoptosis of A549 cells.The inhibitory effect of RNAi is characterized by its specificity,high efficiency and durability.This may lay an experimental foundation for further study of gene therapy in lung cancer.