Determination of tin and its compounds in ambient PM2.5 by atomic fluorescence spectrometry after ultrasonic extraction with concentrated hydrochloric acid / 环境与职业医学

Background Tin and its compounds can cause serious harm to human respiratory system and nervous system, but there is no corresponding national standard method for the determination of tin in PM2.5. Objective To establish a method for the determination of tin and its compounds in PM2.5 by atomic fluorescence spectrometry (AFS) after ultrasonic extraction with concentrated hydrochloric acid. Methods We extracted a fixed volume of air at a constant speed through a sampler with preset cutting characteristics to trap PM2.5 in the ambient air on quartz filter membranes. By selecting extraction solvent, comparing extraction temperature and time, and adjusting the acidity of solution to be measured, the sample pretreatment process was optimized, and a method for the determination of tin and its compounds in PM2.5 by AFS was proposed, and its performance indexes such as linearity, detection limit, and lower limit of quantification were obtained. The accuracy and precision of the method were evaluated by the standard addition recovery test with blank quartz filter membranes, and the interference test was carried out by adding standard urban particulate samples. The proposed method and the method recommended by the “Handbook on Monitoring and Protection of Air Pollution (Haze) Effects on Population Health (2020)” (the Handbook) were applied to actual samples, and the results were compared. Results This experiment used concentrated hydrochloric acid as the extraction solvent. The higher the reaction temperature and the longer the reaction time, the higher the recovery rate. Therefore, 70 ℃ water bath ultrasonic extraction for 3 h was selected. In terms of the proposed method, the linear range of detection was from 5.00 μg·L−1 to 50.00 μg·L−1, with a correlation coefficient ≥0.999 and a detection limit of 0.27 μg·L−1. When the quantitative detection of the lower limit was 0.90 μg·L−1，and the sampling volume was 144 m3, the limit of quantification was 1.25 ng·m−3. The recovery rate of standard addition of blank quartz filter membranes was 94.1%-97.5%, with a relative standard deviation ≤3.2%; the recovery rate of standard addition of standard urban particulate matter samples was 93.5%-103.0%, and the relative standard deviation was ≤2.1%, indicating that coexisting components in PM2.5 samples would not affect the determination of tin. For the 10 quartz filter membrane samples of PM2.5 monitoring, the results of tin by the established method (extraction with concentrated hydrochloric acid) were higher than those of the Handbook recommended method (extraction with nitric acid), and the difference is (3.61±0.54) ng·m−3(t=21.303, P<0.05). Conclusion The established method for the determination of tin and its compounds in PM2.5 by AFS after ultrasonic extraction with concentrated hydrochloric acid is simple, accurate, and suitable for laboratory determination of tin and its compounds in large quantities of PM2.5 samples.

Clinicopathological features and prognosis of colorectal stromal tumor / 北京大学学报(医学版)

OBJECTIVE@#The incidence of colorectal stromal tumor is low among digestive tract tumors, therefore the literatures about clinicopathological features and prognosis of colorectal stromal tumor are few at home and abroad. In this study, we performed survival analyses for colorectal stromal tumor. The nomogram made by prognostic factors provided basis for evaluation of prognosis.@*METHODS@#The clinico-pathological and prognostic data of colorectal stromal tumor between January 1992 and December 2015 were collected from the surveillance, epidemiology, and end results (SEER) database. The survival analyses were made by SPSS 24.0 software. The nomogram and calibration curve were made by RMS package in R 3.5.2 software.@*RESULTS@#In the study, 546 patients with colorectal stromal tumor were included. The median age of onset was 64 years. The regional lymph node metastasis (LNM) rate was 9.4%. The multivariate Cox regression analyses of the 546 cases showed that the older age of onset (>64 years), single or divorce, colon tumor (compared with rectal tumor), non-surgery, high histological grade, LNM and distant metastasis were associated with worse cancer specific survival (CSS) and overall survival (OS), P < 0.05 for all. The treatment district was independent prognostic factor of OS (P = 0.027). The C-index of independent prognostic factors predicting CSS and OS probability were 0.76 (95%CI: 0.72-0.80) and 0.75 (95%CI: 0.72-0.78), respectively. Multivariate analyses were further carried out in the 174 patients with definite histological grade and tumor location, which revealed that the age of onset, histological grade, surgery or not were independent prognostic factors of CSS and OS (P < 0.05 for all). Tumor location was associated with CSS (P = 0.041) but not OS (P = 0.057) among the 174 cases. Four independent prognostic factors influencing the 174 patients' prognosis were used to make nomogram for predicting survival probability of 546 cases. The C-index of four prognostic factors predicting probability of CSS and OS of the 546 cases were separately 0.71 (95%CI: 0.66-0.75) and 0.73 (95%CI: 0.70-0.77). The nomogram had more accuracy for predicting OS probability of colorectal stromal tumors.@*CONCLUSION@#The prognosis of colorectal stromal tumor was affected by multiple clinicopathological factors. The nomogram provided the basis for predicting the survival probability of patients with colorectal stromal tumor.

Influencing factors affecting the retinal blood vessel morphology in patients with diabetes mellitus / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyze the influencing factors affecting retinal blood vessel morphology in patients with diabetes mellitus. <p>METHODS: Totally 312 patients with type 2 diabetes mellitus in our hospital from January 2012 to September 2016 were selected as study subjects. The patients were examined by fundus photography and related laboratory. As grouping factors in the patients'age, sex, disease duration, smoking, drinking, hypertension, hyperlipidemia or diabetic nephropathy, we compared the incidence of retinal vascular changes in different groups. The meaningful factors were introduced into the Logistic regression equation again. Independent risk factors for retinal vascular changes in patients with diabetes mellitus were screened out. <p>RESULTS:In 312 cases of patients with type 2 diabetes mellitus,169 cases were accompanied with retinal vascular abnormalities, and 143 cases were not associated with retinal vascular abnormalities. Univariate analysis showed that age, duration of disease, hypertension, hyperlipidemia or diabetes nephropathy were significantly correlated with retinal vascular morphological changes(<i>P</i><0.05). Sex, smoking or drinking had no significant correlation with retinal vascular abnormality(<i>P</i>>0.05). Retinal vascular abnormalities were used as the dependent variable, and the above mentioned factors were grouped as independent variables. By Logistic stepwise regression analysis showed that the course of disease, patients with hypertension or diabetic nephropathy were the independent risk factors of abnormal retinal vascular morphology(<i>P</i><0.05). <p>CONCLUSION: The independent risk factors for the occurrence of retinal vascular changes in patients with diabetes mellitus are increased course of disease, hypertension or diabetic nephropathy. Early diagnosis and intervention, to take measures and control blood pressure, reduce kidney damage can reduce the incidence of diabetic retinopathy, and macrovascular disease caused by diabetes, the incidence of adverse cardiovascular and cerebrovascular events.

Roles of atypical chemokine receptors in progression and metastasis of tumor / 中国病理生理杂志

[ ABSTRACT] Chemokines and their receptors have been implicated mostly in tumor progression and metastasis. Atypical chemokine receptors ( ACKRs) comprise a group of 7-transmembrane domain proteins structurally similar to G pro-tein-coupled receptors.However, ACKRs do not induce classical signaling via the typical G protein-mediated pathways. ACKRs efficiently internalize the cognate chemokine ligands and act as scavengers instead.ACJRs are composed of at least 3 members of chemokine receptors: Duffy antigen receptor for chemokines ( DARC, also known as ACKR1 ) , D6 ( also known as ACKR2) and ChemoCentryx chemokine receptor (CCX-CKR, also known as ACKR4).These receptors bind to and/or internalize their chemoattractant ligands without activating signal transduction cascades leading to cell migration.In this review, we summarize the recent progress regarding the roles of ACKRs in the progression and metastasis of tumor.

Metabonomic study of plasma after intratracheally instilling titanium dioxide nanoparticles in rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>1H magnetic resonance (1H MR) spectroscopic technique in combination with pattern recognition technique were applied to analyze toxic effects of rats which were intratracheally instilled with titanium dioxide nanoparticles (nano-TiO2) as well as to detect the target organs and biomarkers associated with the toxic effects.</p><p><b>METHODS</b>Twenty-four SD male rats were divided into 4 groups randomly which were high dose group (40 mg/kg nano-TiO2), moderate dose group (4 mg/kg nano-TiO2), low dose group (0.4 mg/kg nano-TiO2) and control group (0.9% NaCl solution) respectively, there were six rats per group. All rats were exposed to the object by single intratracheally instilling at a volume of 0.1 ml/100 g. After one week observation, 1H MR spectra of plasma were measured and analyzed by principal component analysis. Histopathologic examination for tissues such as heart, lung, liver, and kidney were performed simultaneously.</p><p><b>RESULTS</b>The relative content of lactate [(37.86+/-2.58)x10(-3)], citrate [(2.21+/-0.45)x10(-3)], choline [(7.74+/-0.76)x10(-3)] and creatine [(4.17+/-1.15)x10(-3)] in high dose group were significantly decreased as compared with those [(52.07+/-5.12)x10(-3), (3.01+/-0.21)x10(-3), (9.28+/-0.78)x10(-3), (8.59+/-2.64)x10(-3)] in control group (t values were -6.024, -3.177, -3.374, -4.215 respectively, P<0.05), however the relative content of glucose [(19.41+/-1.72)x10(-3)] was significantly increased compared with that [(14.45+/-2.45)x10(-3)] in control group (t value was 2.802, P<0.05). The relative content of lactate [(44.39+/-5.09)x10(-3)] and creatine [(3.67+/-0.76)x10(-3)] in moderate group was significantly decreased compared with those [(52.07+/-5.12)x10(-3), (8.59+/-2.64)x10(-3)] in control group (t values were -3.254, -4.694 respectively, P<0.05). The relative content of pyruvate [(3.84+/-0.70)x10(-3)] was significantly increased in low dose group as compared with that [(3.13+/-0.46)x10(-3)] in control group (t value was 2.787, P<0.05), however the relative content of creatine [(8.10+/-0.72)x10(-3)] was significantly decreased compared with that [(9.28+/-0.78)x10(-3)] in control group (t value was -2.602, P<0.05). No significant difference was found between other experimental groups and control group. No visible damage was found in histopathologic examination.</p><p><b>CONCLUSION</b>Lung, liver, kidney and heart were the target organs of rats which were intratracheally instilling titanium dioxide nanoparticles. Lactate, pyruvate, glucose, citrate, choline and creatine can be presumed as the biomarkers when searching the target organs of the toxic effects.</p>

Effect of constitutive androstane receptor on the cytotoxicity of mitomycin C and 5-(aziridin-1-yl)-3-hydroxymethyl-1-methylindole-4,7-dione / 药学学报

This study is to evaluate the cytotoxicity of mitomycin C (MMC) and its analogue 5-(aziridin-1-yl)-3-hydroxymethyl-1-methylindole-4,7-dione (629) as well as the effect of transfection of constitutive androstane receptor (CAR) on their biological effects. HepG2 cells were transfected with the plasmids mCAR1/pCR3 mediated by liposome. Vector pCR3 was used as control. Transfected cells were screened by G418 resistance and limiting dilution. The expressions of plasmid mCAR1/pCR3 and CYP2B6 mRNA were detected by RT-PCR; Cytotoxicities of MMC and 629 in vitro were evaluated in g2car cells and HepG2 cells by MTT method under anaerobic and aerobic conditions. mRNA expression of CAR and CYP2B6 can not be detected in HepG2 cells and HepG2/pCR3 cells but can in g2car cells. It is shown that plasmid mCAR1/pCR3 was transfected into g2car cells successfully and target CYP2B6 was transactivated by CAR. To compare with aerobic and anaerobic, the cytotoxicities of MMC and 629 to HepG2 cells and g2car cells had significantly enhanced (P < 0.05), and transfect CAR gene can improve the cytotoxicity of MMC (P < 0.05), but not 629 (P > 0.05). Furthermore, CYP2B6 is one master enzyme for the metabolism of MMC and not 629. Transfection of CAR can increase expression of CYP2B6 mRNA in HepG2 cells, and can affect cytotoxicities of MMC and 629.

Apoptosis of type II alveolar epithelial cell induced by bleomycin in lung fibrotic rat / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effects of bleomycin (BLM) on the apoptosis of type II alveolar epithelial cell (AT II) in lung fibrotic rats and its possible mechanisms.</p><p><b>METHODS</b>Totally 32 male Sprague-Dawley rats were randomly divided into sham group (n = 8) and BLM group (n = 24). Rats in sham group or BLM group were intratracheally instillated with saline or 5 mg/kg of bleomycin, respectively. One, three, and seven days after the instillation of bleomycin, 8 rats in BLM group were taken for AT II isolation and purification. Rats in sham group were used to isolate and purify AT II on 7 days after the instillation of saline. The cell cycle and apoptosis, intracellular free calcium concentration, and mitochondrial membrane potential (MMP) in AT II were determined by flow cytometry. Immunohistochemistry was performed to observe the expressions of Bax, Bcl-2, and Fas. Caspase-3, Caspase-8, and Caspase-9 activities were measured by Caspase activity detection kit.</p><p><b>RESULTS</b>The ratio of S phase AT II in BLM group was significantly lower than in sham group (P < 0.05). AT II apoptosis rates on day 1 and 3 were significantly higher in BLM group than in sham group (P < 0.01). Intracellular free calcium concentrations in BLM group were significantly higher than in sham group (P < 0.05). However, MMP was significantly lower than sham group (P < 0.05). The positive rates of Bax, Fas and Caspase-3, Caspase-8, and Caspase-9 activities of BLM group were significantly higher than those of sham group (P < 0.05, P < 0.01). The positive rates of Bcl-2 on day 1 and 3 were significantly lower than those of sham group (P < 0.05).</p><p><b>CONCLUSION</b>Early AT II apoptosis may be induced by bleomycin, which may be explained by the increase of intracellular free calcium concentration, depression of MMP, increased expressions of Fas and Bax, and increase of Caspase-3, Caspase-8, and Caspase-9 activities.</p>

Changes of matrix metalloproteinases activities in pulmonary fibrosis rats / 中国医学科学院学报

<p><b>OBJECTIVE</b>To observe the changes of matrix metalloproteinases (MMPs) activities in pulmonary fibrosis rats.</p><p><b>METHODS</b>Eighty male SD rats were randomly divided into sham group (n = 40) and bleomycin group (BLM, n = 40), in which SD rats were injected with a single intratracheal dose of sham saline or bleomycin respectively. On day 1, 3, 7, 14, and 28 following bleomycin or saline instillation, rats were randomly killed, and serum from abdominal aorta, alveolar fluid from the bronchoalveolar lavage, and the lung homogenate were collected and then stored at -80 degrees C. MMPs activity was determined by zymography.</p><p><b>RESULTS</b>Compared with sham group, the levels of MMP-9 in all samples were augmented. MMP-9 activities in the serum were highest on day 3 than those on day 1 and day 7, and in lung tissue homogenate were highest on day 7; however, no significant differences were found between BLM group and sham group on day 14 and day 28; and that of bronchoalveolar lavage fluid (BALF) was highest on day 7 than those on day 1 and day 14, while no significant difference existed between BLM group and sham group on day 28. Serum MMP-2 level did not change from day 1 to day 28, while the level of BALF MMP-2 began to increase after day 14, even on day 28. Lung tissue homogenate MMP-2 level began to increase early on day 3 and continued to day 28.</p><p><b>CONCLUSION</b>The sources and effects of MMP-2 and MMP-9 differ in BLM-induced rat pulmonary fibrosis.</p>

Effect of inducible nitric oxide synthase on tumour cells sensitivity to mitomycin C analogue 629 in vitro / 药学学报

<p><b>AIM</b>To examine the effect of inducible nitric oxide synthase (iNOS) on tumour cells chemosensitivity to mitomycin C (MMC) analogue 5-aziridinyl-3-hydroxyl-1-methylindole-4,7-dione (629) in vitro, and elucidate the possible role of iNOS in the metabolism of 629.</p><p><b>METHODS</b>Human sarcoma cells (HT1080) and its iNOS gene transfected clones (iNOS9, iNOS12) were exposed to 629 at concentrations of 1 nmol x L(-1) - 100 micromol x L(-1). 3-[4, 5-Dimethylthiazol-2-yl] -2,5-diphenyltetrazolium bromide (MTT) assay, agarose electrophoresis and flow cytometric analysis were used to determine cell sensitivity, deoxyribonucleic acid (DNA) damage and the change of cell cycle in above process, respectively. All experiments were performed both in air and under hypoxia parallelly.</p><p><b>RESULTS</b>629 was more toxic than MMC, and enhanced cytotoxicity under hypoxia, which resulted in cell necrosis. Sixteen hours after treated with 629, HT1080 cells and related iNOS-transfected clone cells were obviously blocked in G2/M phase.</p><p><b>CONCLUSION</b>iNOS plays dual roles in 629 metabolism, enhancing or decreasing the cytoxicity of 629 depending on the intracellular oxygen pressure P(O2), which caused higher cytotoxicity to hypoxia cells of 629 with the increasing of iNOS activity.</p>

Rat alveolar type II injured by bleomycin / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore dysfunction mechanism of rat alveolar type II (AT-II) injured by bleomycin (BLM).</p><p><b>METHODS</b>SD rats were injected with a single intratracheal dose of bleomycin or control saline. On day 7, 14, and 28 following intratracheal bleomycin or saline instillation, animals were killed under overdose of 1.5% sodium pentobarbital (0.25 ml/100 g, i.p.) and bronchoalveolar lavage fluid (BALF) from the lung was tested for the activity of pulmonary surfactant (PS) by the Whihelmy Film Balance. Several concentrations of bleomycin stimulated the culture of rat AT-II cells, and surfactant protein (SP) A, B, and aquaporin-1 (AQP) mRNA were analyzed by fluorescent quantitative polymerase chain reaction (FQ-PCR).</p><p><b>RESULTS</b>The activity of PS and hypoxemia significantly decreased on day 7 and improved on day 14 and completely recovered to normal status on day 28. SP-A, B, and AQP-1 mRNA expression in BLM-stimulated group were significantly lower than those in the control group (P<0.001).</p><p><b>CONCLUSION</b>BLM-injured AT-II cells decrease the levels of SP-A, B, and AQP-1 mRNA and cause PS dysfunction, resulting in hypoxemia and pneumonedema.</p>

DNA damage induced by methyl tertiary-butyl ether in vivo and in vitro / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of methyl tertiary-butyl ether (MTBE)-induced animal carcinoma.</p><p><b>METHODS</b>Single cell gel electrophoresis assay (SCGE), DNA cross-links test and unscheduled DNA synthesis (UDS) assay were conducted with cultured rat type II pneumocytes and rat hepatocytes in vitro. Except UDS assay, the same experiment was performed in hepatocytes, renal cells and pneumocytes of mice administrated MTBE by inhalation at 0, 108, 1,440 and 4,968 mg/m(3) for 20 consecutive days. Simultaneously, the contents of malondialdehyde (MDA) in homogenates of lung and kidney were determined.</p><p><b>RESULTS</b>The lengths of DNA migration in mice hepatocytes at 1,440, 4,968 mg/m(3) of MTBE, renal cells at all doses of MTBE, and pneumocytes at 4,968 mg/m(3) were greater than those in negative controls. There was dose-effect relationship between the concentration of MTBE and hepatocytes DNA migration lengths in mice (r = 0.997, P = 0.003). MTBE of 1,440 and 4,968 mg/m(3) contributed to a rise in MDA of renal homogenates in female mice (P < 0.05). MTBE above 0.050 mmol/L caused greater DNA migration in cultured rat type II pneumocytes and rat hepatocytes in vitro (P < 0.05), and also with dose-effect relationship (r(lung) = 0.967, r(liver) = 0.963, P < 0.05)). In UDS assay, DNA synthesis of rat type II pneumocytes and rat hepatocytes were increased at the concentration of 5.0 mmol/L and 10.0 mmol/L of MTBE.</p><p><b>CONCLUSION</b>MTBE has some genotoxicity on DNA, and the single strand breaks of cell and lipid peroxidation may be one of the possible mechanism of MTBE-induced hepatic and renal tumors of animal.</p>

The protective effects of Fufang Biejiafang on bleomycin-induced pulmonary fibrosis in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To explore the possible effects and mechanism of Fufang Biejiafang on a single intratracheal instillation (IT) of bleomycin-induced lung fibrosis model.</p><p><b>METHOD</b>SD rats were treated with a single IT dose of bleomycin or control saline. Chinese medicine group were poured into the stomach after the first day of operation with high dosage, middle dosage and low dosage. On days 7, 14 and 28 following IT bleomycin or saline, 4 mL blood were taken from the abdominal aorta for arterial blood gas analysis. The left lung was fixed for routine light microscopic examination. Bronchoalveolar lavage fluid (BALF) from the right lung was tested the activity of pulmonary surfactant (PS) by the Whihelmy Film Balance, then the right lung was frozen immediately in liquid nitrogen for determination of hydroxyproline concentration.</p><p><b>RESULT</b>Model rats had obviously changes of body weight and hypoxemia and dysfunction of PS on days 7 and improved on days 14. Compared with three dose groups, the middle dose group some degreely improved and PS function. It ameliorate fibrosis because of inhibition of inflammation.</p><p><b>CONCLUSION</b>(1) PS dysfunction resulted in hypoxemia after bleomycin injured alveolar type II (AT II). Fufang biejiafang-middle dose-group ameliorate hypoxemia by remission AT-II injury. (2) Fufang biejiafang may inhibit exudation inflammation and ameliorate fibrosis.</p>

Oxidative Damage in Cultured CHL Cells Induced by Joint Action of Benzene and Formaldehyde / 环境与健康杂志

Objective To investigate the joint action of benzene and formaldehyde for oxidative damage effects on cultured CHL cells.Methods Twenty-four hours after the cultured CHL cells exposed to formaldehyde(0,0,0,0.319 75,0.319 75,0.319 75,0.639 5,0.639 5,0.639 5 ?g/ml) or(and) benzene(0,0.392,0.784,0,0.392,0.784,0,0.392,0.784 mg/ml),the level of glutathione(GSH),malondialdehyde(MDA) and the activity of superoxide dismutase(SOD) were determined.Results Twenty-four hours after formaldehyde or(and) benzene exposure,the level of GSH reduced,activity of SOD reduced significantly(P

Preparation of chitosan-5-fluorouracil nanometer particle and its drug-release characters / 解放军医学杂志

Objective To prepare the nanometer particles (NPs) of chitosan-5-fluorouracil (5-FU), and to study its characters of drug release in vivo. Methods Cross-linking polymer technique was employed to prepare the chitosan-5-FU NPs, and their characters were detected by scanning electron microscope and photon correlation spectroscope (PCS); the loaded capacity was measured by ultraviolet spectrophotometry; high-performance liquid chromatography was used to detect the characters of drug release in vivo. Results The chitosan-5-FU-NPs were found to be round or elliptic in shape, with 120 to 150nm in diameter and having a good dispersive ability. The loaded capacity was 31.000%?0.001%. The blood concentration of 5-FU was controlled at 76?g/L, and it was maintained for 48h. Conclusion As a vehicle, chitosan-5-FU NPs can change the behavior of pharmacokinetics and prolong the cycle time of 5-FU in vivo. Chitosan-5-FU NPs ran reduce the initial burst and prolong the releasing time.