[Pollution characteristics and health risk assessment of heavy metals in PM(2.5) in Lanzhou]

Objective: To understand the pollution characteristics and assess the pollution health risks of heavy metals in atmospheric PM(2.5) in Lanzhou. Methods: According to the regional characteristics of air pollution and industrial distribution characteristics in Lanzhou, atmospheric PM(2.5) was sampled monthly in Chengguan and Xigu Districts from January, 2015 to December, 2016. Detected the concentration of PM(2.5) and 12 kinds of elements (Sb, Al, As, Be, Cd, Cr, Hg, Pb, Mn, Ni, Se and Tl) by weighing method and inductively coupled plasma mass spectrometry. Enrichment factor and geo-accumulation index were used to describe the pollution characteristics, while health risk assessment was conducted using the recommended United States Environmental Protection Agency (USA EPA) model. The health risks of non-carcinogens were evaluated by non-cancer hazard quotient (HQ), the non-carcinogenic risk was considered to be negligible when HQ<1, HQ>1 meant a health risk. With a single contaminant cancer Risk value to evaluate the health risks of carcinogens, when the Risk value between 10(-6) to10(-4) as an acceptable level. Results: The daily average concentrations of PM(2.5) was 83.0 μg/m(3), 77.0 μg/m(3) in Chengguan and Xigu Districts, respectively, during the sampling periods, and the concentration of PM(2.5) in winter/spring was higher than summer/fall in both districts. The concentration of Al in PM(2.5) was the highest and other elements in descending order: Pb, Mn, As, Sb/Cd, Tl in both districts. Enrichment factor results showed that Al and Mn were mainly affected by natural factors, the rest of five elements were all typical man-made pollution elements and according to geo-accumulation index pollution level of Cd was the strongest in the winter. The results of health risk assessment showed that Mn had the highest non-cancer risks (HQ>1) and affected the health of the children seriously. HQ reached up to 2.44 and 1.79 in Chengguan and Xigu Districts, respectively. Pb, As, Sb, Cd had slight health impact (HQ<1), could be negligible. The cancer risks range of As, Cr were 6.33×10(-6) to 6.46×10(-5) between the acceptable level of risk (10(-6) to 10(-4)), which indicated that As and Cd had potential cancer-risks. Conclusions: The pollution level of atmospheric PM(2.5) and the heavy metals in it was still grim;the non-cancer risks caused by multiple metals on children deserved attention. Although the cancer risks of As and Cd were between the acceptable level of risk, the potential cancer risk still shall not be ignored.

Quantitative structure-activity relationship of anti-HIV integrase and reverse transcriptase inhibitors using norm indexes

The development of new and safe anti-human immunodeficiency virus (anti-HIV) drugs has been an urgent task for medical research recently. Herein, based on the norm-index descriptors proposed in this work and previous works, a couple of models were developed for investigating the quantitative structure-activity/toxicity relationship (QSAR/QSTR) of dual-target anti-HIV integrase (IN) and reverse transcriptase (RT) inhibitors. The validation results proved that the developed models were stable and reliable, both in statistical quality and predictive capacity. Moreover, potential dual-target inhibitors with high activity and low toxicity were deduced from the developed models; molecular docking results indicated that these inhibitors could interact with some important residues of HIV IN and RT through H-bonding. Accordingly, the norm indexes descriptors proposed by this work might be helpful for the research and development of dual-target anti-HIV drugs.

[Effect of mitogen-activated protein kinase signaling pathway on apoptosis induced by chloroacetic acid in human normal bronchial epithelial 16HBE cells]

Objective: The aim of this study was to investigate the effect of mitogen-activated protein kinase (MAPK) signaling pathway on apoptosis induced by chloroacetic acid in human normal bronchial epithelial 16HBE cells. Methods: 16HBE cells were exposed to 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 mmol/L chloroacetic acid for 24 h in vitro. The cytotoxicity induced by chloroacetic acid was assessed by CCK-8 and LDH assays. Cell apoptosis was detected by Annexin V-FITC and PI staining. The protein expression levels of phosphorylation of p38, ERK1/2 and JNK were determined by western blotting. 16HBE cells were pretreated with MAPK signaling pathway specific inhibitors including SB203580, U0126 and SP600125 for 1 h, and these cells were subsequently treated with 2.5 mmol/L chloroacetic acid for 24 h. The expressions of p-p38, p-ERK1/2 and p-JNK as well as the changes of cell viability and apoptosis were measured after pretreated with inhibitors for 1 h. Results: The cell viability by CCK-8 and LDH methods gradually reduced in a dose-dependent manner when chloroacetic acid concentrations elevated (P<0.05) , and their correlation coefficients were -0.902 and -0.825, respectively. The detection efficiency of CCK-8 assay significantly increased compared with LDH assay (P<0.05) . The cell apoptosis rates, which were (17.2±4.0) %, (24.6± 4.2) %, (39.3 ± 5.7) % in 1.5, 2.0, 2.5 mmol/L chloroacetic acid-treated groups, were higher than that of the control group[ (5.6 ± 3.0) %] (P<0.05) . There was a time-or dose-dependent change in the protein expressions of p-p38, p-ERK1/2 and p-JNK. Compared with the control, the levels of p-p38 had 2.1 and 2.6-fold increases in 16 and 24 h treated groups (P<0.01) , while the levels of p-ERK1/2 distinctly decreased by 37% and 52% (P<0.01) . In comparison with the control group, the expressions of p-p38 had 1.9 and 2.6-fold increases in 1.5 and 2.5 mmol/L treatment groups (P<0.01) , whereas the expressions of p-ERK1/2 significantly decreased by 40% and 50% (P<0.01) . No significant change was observed in p-JNK protein expression between the chloroacetic acid-treated and control groups. In comparison with the vehicle control and the exposed group, p-p38, p-ERK1/2, p-JNK protein expressions significantly declined in the inhibitor controls and inhibitor groups. Compared with the controls, the cell survival rates had significant reductions of 28%, 18%, 36% and 26% respectively in chloroacetic acid treated group, SB203580 group, U0126 group and SP600125 group, and the apoptosis rates in the abovementioned groups were 7, 4, 8 and 7 times. Compared with chloroacetic acid-treated group, the cell viability increased by 14% in SB203580 group and decreased by 11% in U0126 group, and the cell apoptosis rates decreased by 36% in SB203580 group and increased by 18% in U0126 group (P<0.05) . But no significant changes were observed in cell viability and apoptosis between SP600125 and chloroacetic acid-treated group. Conclusion: Chloroacetic acid might activate p38 MAPK signaling pathway and inhibit ERK1/2 MAPK signaling pathway. The signaling pathways of p38 and ERK1/2 MAPK are involved in 16HBE cell apoptosis induced by chloroacetic acid, but JNK is not involved in chloroacetic acid-induced 16HBE cell apoptosis.

[Analysis of correlation between pulmonary function and expression levels of matrix metalloproteinases-9 and tissue inhibitor of metalloproteinase-1 among toluene diisocyanate exposed workers]

OBJECTIVE

To investigate the effect of occupational toluene diisocyanate(TDI) exposure on matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of metalloproteinase-1(TIMP-1), and analysis of the correlation of MMP-9,TIMP-1,MMP-9/TIMP-1 and lung function.

METHODS

In October 2014, based on cluster sampling, we conducted a cross-sectional study in a TDI production factory located in China's western region. 61 exposed workers were recruited from workers engaged in packing, operating and checking. Based on different levels of the external exposure, the packers were classified as high exposed group, while operators and checkers as low exposed group. 58 factory managers, matching age and agent, were selected as controls, having same work intense and not contacting the TDI or other allergens. The questionnaire surveys were used to obtain the agent, age, work age, smoking and drinking, personal and family allergic history, occupational history, and the recent health conditions. The levels of MMP-9 and TIMP-1 in serum of subjects were determind by ELISA. The time weighted average concentrations (8h-TWA) were used to describe the levels of TDI air exposure in working environment. Spearman correlation assay was used to investigate the correlation of MMP-9, TIMP-1, MMP-9/TIMP-1 and lung function, exposure time.

RESULTS

8-hour TWA means of TDI air levels in exposed group, packers, operators and checkers were 0.39, 0.76, 0.25 mg/m(3), respectively . According to the external exposure concentration, the packers were classified as high exposed group, and the operators and checkers were classified as low exposed group. In controls, low exposed group and high exposed group, the levels of MMP-9, respectively, were (807.21±347.70),(586.91±317.50),(388.94±312.01) ng/ml (χ(2)=16.69, P<0.001), respectively, and the P50(P25-P75) of MMP-9/TIMP-1 were 4.67(2.87-6.68), 2.3(1.44-3.48), 1.11(0.59-1.48) (χ(2)=39.42, P<0.001), respectively, and the concentrations of TIMP-1, were (173.44±72.67), (236.12±51.98), (302.81±44.39) ng/ml (F=20.09, P< 0.001), respectively. The levels P50(P25-P75) of FVC, FEV1.0 and FEV1.0/FVC in exposed group were, 92.8% (86.0%-101.8%), 85.5%(76.7%-92.8%), 112.5(108.2-118.5), respectively, which were lower than that in control group (124.3%(107.9%-144.2%), 142.7%(119.1%-155.7%), 129.2(123.5-134))(Z values were 7.70, 8.97, 8.62, and all P<0.001). Spearman rank correlation analysis showed that levels of MMP-9 were positively associated with FEV1.0, and FEV1.0/FVC (r values were 0.27, 0.25, respectively, all P<0.05), and The levels of TIMP-1 were negatively associated with FVC, FEV1.0, and FEV1.0/FVC (r valuse were -0.33, -0.39, -0.39, all P<0.05).The levels of MMP-9 were negatively correlated with exposure time(r=-0.26, P=0.040). The positive correlations of MMP-9/TIMP-1 with FVC, FEV1.0, and FEV1.0/FVC were also found (r valuse were 0.34, 0.44, 0.40, all P<0.05).

CONCLUSION

TDI exposure could induce the downs of MMP-9 and MMP-9/TIMP-1 associated with lung functions. The MMP-9 and MMP-9/TIMP-1,in a way, could reflect the respiratory inflammatory injury caused by TDI exposure.

A universal mechanism of extreme events and critical phenomena

The occurrence of extreme events and critical phenomena is of importance because they can have inquisitive scientific impact and profound socio-economic consequences. Here we show a universal mechanism describing extreme events along with critical phenomena and derive a general expression of the probability distribution without concerning the physical details of individual events or critical properties. The general probability distribution unifies most important distributions in the field and demonstrates improved performance. The shape and symmetry of the general distribution is determined by the parameters of the fluctuations. Our work sheds judicious insights into the dynamical processes of complex systems with practical significance and provides a general approach of studying extreme and critical episodes in a combined and multidisciplinary scheme.

The heterogeneous energy landscape expression of KWW relaxation

Here we show a heterogeneous energy landscape approach to describing the Kohlrausch-Williams-Watts (KWW) relaxation function. For a homogeneous dynamic process, the distribution of free energy landscape is first proposed, revealing the significance of rugged fluctuations. In view of the heterogeneous relaxation given in two dynamic phases and the transmission coefficient in a rate process, we obtain a general characteristic relaxation time distribution equation for the KWW function in a closed, analytic form. Analyses of numerical computation show excellent accuracy, both in time and frequency domains, in the convergent performance of the heterogeneous energy landscape expression and shunning the catastrophic truncations reported in the previous work. The stretched exponential β, closely associated to temperature and apparent correlation with one dynamic phase, reveals a threshold value of 1/2 defining different behavior of the probability density functions. Our work may contribute, for example, to in-depth comprehension of the dynamic mechanism of glass transition, which cannot be provided by existing approaches.

Consumption of Chilies, but not Sweet Peppers, Is Positively Related to Handgrip Strength in an Adult Population

BACKGROUND

Chili consumption may have a beneficial effect on muscle strength in the general population. The aim of this study was to investigate the relationship between frequency of chili consumption and handgrip strength in adults.

DESIGN

Population-based cross-sectional study.

SETTING

This study used baseline data from the Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study.

PARTICIPANTS

A total of 3 717 subjects were recruited to the study. Frequency of chili consumption during the previous month was assessed using a valid self-administered food frequency questionnaire. Analysis of covariance was used to examine the relationship between muscle strength and frequency of chili consumption. Handgrip strength was measured using a handheld digital dynamometer.

RESULTS

After adjustment for potential confounding factors, significant relationships were observed between different categories of chili consumption and handgrip strength in males, the means (95% confidence interval) for handgrip strength across chili consumption categories were 44.7 (42.1, 47.2) for < one time/week; 45.5 (42.9, 48.1) for one time/week; and 45.8 (43.3, 48.4) for ≥ 2-3 times/week (P for trend < 0.01). Similar results were not observed with sweet pepper consumption.

CONCLUSIONS

This study reveals a positive correlation between frequency of chili consumption and muscle strength in adult males. Further studies are necessary in order to determine whether there is a causal relationship between chili consumption frequency and muscle strength.

Dietary patterns are associated with prevalence of fatty liver disease in adults

BACKGROUND/OBJECTIVES

Previous studies have indicated that higher levels of food consumption are associated with fatty liver disease (FLD), but few studies have investigated the relationship between this disease and different dietary patterns. The aim of this cross-sectional study was to examine the association between dietary patterns and FLD in adults.

SUBJECTS/METHODS

Dietary intakes of participants in the Tianjin were assessed via questionnaire. Factor analysis was used to identify dietary patterns, and FLD was defined as having a FLD diagnosis using liver ultrasonography. Relationships between dietary patterns and FLD were assessed using multiple logistic regression analysis.

RESULTS

Female participants in the highest quartile of high-carbohydrate/sweet pattern scores had a 2.19-fold greater risk (95% confidence interval (CI), 1.40-3.46) of developing non-alcoholic FLD (NAFLD) than those in the lowest quartile after adjusting for confounding factors. No significant differences were found between any dietary pattern and NAFLD in males. In males, a significantly increasing trend of alcoholic FLD (AFLD) prevalence was associated with increasing high-protein/cholesterol pattern scores (P for trend = 0.03; odds ratio (OR), 2.08; 95% CI, 1.15-3.81) while an increased high-carbohydrate/sweet pattern score appeared protective against AFLD (P for trend = 0.02; OR, 0.55; 95% CI, 0.29-1.00).

CONCLUSIONS

Our study demonstrates that high-protein/cholesterol pattern scores are associated with higher prevalence of AFLD in males. We also show high-carbohydrate/sweet pattern scores are associated with higher prevalence of NAFLD in females; but, interestingly, this pattern shows a favorable effect on AFLD in males.

Peptide-binding motifs and characteristics for HLA -B*13:01 molecule

Trichloroethylene (TCE)-induced hypersensitivity dermatitis is one of the critical occupational diseases among workers in China. Our previous studies have identified a strong linkage between the disease and the HLA-B*13:01 allele. In this study, we searched for peptides bound to the HLA-B*13:01 molecule; 57 HLA-B*13:01-bound peptides in total were identified and 54 peptides were used to calculate frequency of amino acid residues to obtain binding motifs of HLA-B*13:01 molecule. The results showed P2, P3, and P9 were the primary binding anchor positions with the dominant anchor motifs of L, Q at P2, L at P9, D at P3. HLA-B*13:01-bound peptides were identified for the first time in our research, the results of which could contribute to the human leukocyte antigen (HLA)-binding peptides database.

Computational identification of citrus microRNAs and target analysis in citrus expressed sequence tags

MicroRNAs (miRNAs) are a new family of small RNA molecules found in plants and animals. We developed a comprehensive strategy for identifying new miRNA homologues by mining the repository of available citrus expressed sequence tags (ESTs). By adopting a range of filtering criteria, we identified a total of 38 potential miRNAs--nine, five, nine and 15 miRNAs in Citrus trifoliata (ctr-miRNAs), C. clementina (ccl-miRNAs), C. reticulata (crt-miRNAs) and C. sinensis (csi-miRNAs), respectively--from more than 430,000 EST sequences in citrus. Using the potential miRNA sequences, we conducted a further BLAST search of the mRNA database and found six potential target genes in these citrus species. Eight miRNAs were selected in order to verify their existence in citrus using Northern blotting, and the functions of several miRNAs in miRNA-mediated gene regulation are experimentally suggested. It appears that all these miRNAs regulate expression of their target genes by cleavage, which is the most common situation in gene regulation mediated by plant miRNAs. Our achievement in identifying new miRNAs in citrus provides a powerful incentive for further studies on the important roles of these miRNAs.

Hypoglycemic activity of a polyphenolic oligomer-rich extract of Cinnamomum parthenoxylon bark in normal and streptozotocin-induced diabetic rats

Cinnamon bark has been reported to be effective in the alleviation of diabetes through its antioxidant and insulin-potentiating activities. The water-soluble polyphenolic oligomers found in cinnamon are thought to be responsible for this biological activity. In this study, the hypoglycemic activity of a polyphenolic oligomer-rich extract from the barks of Cinnamomum parthenoxylon (Jack) Nees was studied in normal, transiently hyperglycemic, and streptozotocin (STZ)-induced diabetic rats. Oral administration of the extract at doses of 100, 200, and 300 mg/kg body wt. caused significant changes in body weight loss and fasting blood glucose levels of normal rats. In STZ-induced diabetic rats, after administration of the extract at doses of 100, 200, and 300 mg/kg body wt. over 14 days, the blood glucose levels were decreased by 11.1%, 22.5%, and 38.7%, respectively, and the plasma insulin levels were significantly increased over pre-treatment levels. In an oral glucose tolerance test, the extract produced a significant decrease in glycemia 90 min after the glucose pulse. These results suggest that Cinnamomum parthenoxylon polyphenolic oligomer-rich extract could be potentially useful for post-prandial hyperglycemia treatment.

The value of dual time point (18)F-FDG PET imaging for the differentiation between malignant and benign lesions

AIM

To assess the clinical value of dual time point 2-[(18)F]-fluoro-2-deoxy-d-glucose positron emission tomography ((18)F-FDG PET) imaging for the differentiation between malignant and benign lesions.

MATERIALS AND METHODS

Ninety-six patients (28 patients with primary lung cancer, 18 patients with digestive system carcinoma, 13 patients with other malignant tumours, and 37 patients with benign lesions) underwent FDG-PET/CT at two time points: examination 1 at 45-55 min and examination 2 at 160+/-24 (150-180) min after the intravenous injection of 233+/-52 (185-370)MBq (18)F-FDG. Reconstructed images were evaluated qualitatively and quantitatively. The maximum standardized uptake values (SUVmax) of the lesions were calculated for both time points. An increase was considered to have occurred if the SUVs at examination 2 had increased by >10% as compared with those at the examination 1.

RESULTS

The lesions in 24 of 28 (86%) patients with primary lung cancer had an SUVmax > or = 2.5 at examination 1. Of these, SUVmax values increased in 23 patients, but had not changed in one patient, at examination 2. The lesions in the other four patients with primary lung tumour had SUVmax values between 1.5 and 2.5 at examination 1, which were considered as suspected positive, increased SUVmax values were observed in three of these patients at examination 2. The malignant lesions in 17 of 18 patients with digestive system carcinoma showed SUVmax values > or = 2.5 and only one patient had an SUVmax value < 1.5 at examination 1; all lesions showed an increase in SUVmax values at examination 2. In 13 patients with other malignant tumours, all lesions had SUVmax values > or = 2.5 at examination 1 and the SUVmax values were further increased at examination 2. Therefore, the malignant lesions in 54/59 (92%) of patients had SUVmax values > or = 2.5 at examination 1 and showed a further increase in SUVmax value at examination 2. Only 12 of 37 (32%) patients with benign lesions showed SUVmax values > or = 2.5 at examination 1 and nine patients with benign lesions had SUVmax values > or = 2.5 in examination 2. The sensitivity, specificity, accuracy, positive and negative predictive values for the early and delayed imaging were 91.5, 67.6, 82.3, 81.8, and 83.3%, and 98.3, 75.7, 89.6, 86.6, and 96.6%, respectively.

CONCLUSION

The results of the present study provide further evidence that dual time point (18)F-FDG PET imaging is an important noninvasive method for the differentiation of malignant and nonmalignant lesions.

A medicinal extract of Scutellaria baicalensis and Acacia catechu acts as a dual inhibitor of cyclooxygenase and 5-lipoxygenase to reduce inflammation

A mixed extract containing two naturally occurring flavonoids, baicalin from Scutellaria baicalensis and catechin from Acacia catechu, was tested for cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) inhibition via enzyme, cellular, and in vivo models. The 50% inhibitory concentration for inhibition of both ovine COX-1 and COX-2 peroxidase enzyme activities was 15 microg/mL, while the mixed extract showed a value for potato 5-LOX enzyme activity of 25 microg/mL. Prostaglandin E2 generation was inhibited by the mixed extract in human osteosarcoma cells expressing COX-2, while leukotriene production was inhibited in both human cell lines, immortalized THP-1 monocyte and HT-29 colorectal adenocarcinoma. In an arachidonic acid-induced mouse ear swelling model, the extract decreased edema in a dose-dependent manner. When arachidonic acid was injected directly into the intra-articular space of mouse ankle joints, the mixed extract abated the swelling and restored function in a rotary drum walking model. These results suggest that this natural, flavonoid mixture acts via "dual inhibition" of COX and LOX enzymes to reduce production of pro-inflammatory eicosanoids and attenuate edema in an in vivo model of inflammation.