Decomposition Process of Nonoxidative Microwave Radiation Roasting of a Mixed Rare Earth Concentrate with Sodium Carbonate

This article introduces an efficient decomposition process that uses sodium carbonate (Na₂CO₃) and activated carbon (C) as additives to decompose Bayan Obo mixed rare earth concentrate (hereinafter to be referred to as RE concentrate) by nonoxidative microwave radiation roasting. The roasting temperature, holding time, and contents of Na₂CO₃ and activated carbon are investigated. The optimum process parameters for decomposition are 800 °C and 30 min. The ratio of m(Na₂CO₃)/m(RE concentrate) is 0.5, and the ratio of m(C)/m (ER concentrate and Na₂CO₃) is 0.2 based on experimental data. Under the above conditions, the decomposition rate (shortened to DR) of RE concentrate is 98.58%, and the removal rates (shortened to CRs) of fluorine (F) and phosphorus (P) reached 80.35 and 46.75%, respectively. These rates are higher than traditional oxidation roasting under the same conditions. The three reasons for the result are the unique microwave heating characteristics, the overall efficient reaction of the mixture (RE concentrate, Na₂CO₃, and activated carbon), and the high nonoxidation rate of cerium. For these reasons and large experimental data, the reaction rate of the mixture is improved, and the efficiency of dilute hydrochloric acid for leaching rare earth elements is enhanced. In this article, the valence of rare earth elements in the roasted ore is all in the form of trivalence. Importantly, this nonoxidative roasted product can avoid the generation of chlorine in hydrochloric acid leaching. Moreover, such a short holding time is scarce in traditional roasting. When the mixture was roasted by utilizing microwave heating, the sinter phenomenon of the roasted product was avoided at high-temperature roasting. Finally, the surface morphology of RE concentrate at different conditions was observed by scanning electron microscopy (SEM) analysis, which can be used to compare the specific differences of roasting methods. According to these results, this process is beneficial for the decomposition of RE concentrate in terms of Na₂CO₃ roasting and is helpful for improving the clean and green technology method of hydrometallurgy.

[Oxymatrine improves renal fibrosis and inflammation in diabetic rats by modulating CHK1/2 phosphorylation]

OBJECTIVE

To explore the role of cell cycle checkpoint kinase 1/2 (CHK1/2) in mediating the inhibitory effect of oxymatrine (OMT) against renal inflammation and fibrosis in diabetic rats.

METHODS

SD rats were randomly divided into normal control group, diabetes model group (DM) and OMT treatment group (n=6). HE and Masson staining were used to observe histopathological changes of the renal tissue, and the expressions of CHK1, CHK2, p-CHK1 and p-CHK2 were localized by immunohistochemical staining. The contents of interleukin-6 (IL-6) and IL-1β in the renal tissue were detected using ELISA, and the expression levels of CHK1, CHK2, p-CHK1, p-CHK2, type Ⅲ collagen (Col-Ⅲ), type Ⅳ collagen (Col-Ⅳ), and fibronectin (FN) were determined using Western blotting. The changes in the expressions of CHK1, CHK2, p-CHK1, p-CHK2, Col-Ⅲ, Col-Ⅳ and FN proteins were also examined with Western blotting in NRK-52E cells in response to high glucose exposure, OMT treatment and siRNA-mediated CHK1/2 knockdown.

RESULTS

In diabetic rats, OMT treatment significantly decreased the levels of blood glucose, serum creatinine and 24 h urinary protein (P < 0.05) and obviously improved inflammatory cell infiltration and fibrosis phenotype in the renal tissue (P < 0.05). CHK1 and CHK2 were mainly expressed in the cytoplasm and nuclei of renal tubule cells, and their phosphorylation levels were significantly higher in DM group than in the control group and OMT group. OMT treatment significantly decreased the protein expression levels of p-CHK1, p-CHK2, Col-Ⅲ, Col-Ⅳ and FN in the renal tissue of diabetic rats and in NRK-52E cells exposed to high glucose (P < 0.05). In NRK-52E cells, CHK1/2 knockdown resulted in significant reduction of the protein expressions of p-CHK1/2, Col-Ⅲ, Col-Ⅳ and FN (P < 0.05).

CONCLUSION

The inhibitory effects of OMT against renal inflammation and fibrosis in diabetic rats are mediated probably by lowered phosphorylation levels of CHK1 and CHK2, which result in reduced release of the downstream inflammatory mediators and decreased secretion and deposition of extracellular matrix.

Dapagliflozin decreases atherosclerotic plaque instability via regulating macrophage pyroptosis

Background

Vulnerable plaques are characterized by infiltration of inflammatory cells, playing a key role in the progression of acute coronary events. It's important to clarify the inflammatory mechanism of unstable plaque formation. Several clinical trials have demonstrated that dapagliflozin could reduce major adverse cardiac events in whether diabetic or non-diabetic patients. However, the underlying cardioprotective mechanism of dapagliflozin remains unclear. This study was aimed to investigate the role of dapagliflozin in regulating macrophage pyroptosis and vulnerable plaque formation.

Methods

20 ApoE−/− mice (control) were fed with high fat diet while another 20 ApoE−/− mice were challenged with high fat diet plus dapagliflozin for 12 weeks. The extent and instability of atherosclerotic plaque was determined by oil-red staining, HE staining, immunofluorescence staining and electron microscopy. Changes in subsets of immune cells were evaluated by flow cytometry. Plasma cytokines were assessed by ELISA. Microarray analysis was applied to detect gene expressions while Western blot and real-time PCR was used to assess gene expression levels.

Results

Morphology studies revealed that dapagliflozin could inhibit plaque formation and reduce instability in ApoE−/− mice. FACS data showed that dapagliflozin could decrease CD11b+Ly6Chigh M1 macrophages differentiation and inhibit foam cells formation in ApoE−/− mice. Microarray analysis and in vitro studies exhibited that dapagliflozin could induce the down regulation of NLRP3, caspase-1, IL-1β, IL-18 and MMP-7/10/12/14 to retard macrophage pyroptosis and foam cell formation.

Conclusions

We have characterized a novel role for dapagliflozin in modulating atherosclerotic lesion development and progression. We envision that this study may provide several potential therapeutic targets for treatment of acute coronary syndromes.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Shanghai Sailing Program

A New Method of Isolation of Mouse Renal Primary Tubular Epithelial Cells

Kidney diseases are becoming an emerging public health problem. In order to further explore the etiology of various kidney diseases, we improved the methods of isolation of primary cultures of mouse renal tubular epithelial cells. At the first stage, the kidneys were perfused with collagenase solution. To this end, the superior mesenteric artery, celiac artery and thoracic aorta were ligated and perfusion was performed through the abdominal aorta. Then, the cells were isolated ex vivo and their integrity, purity, viability, and concentration were evaluated. The proposed cost-effective and simple method provides high purity and high concentration of primary renal epithelial cells for molecular biology studies of the kidneys.

Elevated urinary mutagenicity among those exposed to bituminous coal combustion emissions or diesel engine exhaust

Urinary mutagenicity reflects systemic exposure to complex mixtures of genotoxic/carcinogenic agents and is linked to tumor development. Coal combustion emissions (CCE) and diesel engine exhaust (DEE) are associated with cancers of the lung and other sites, but their influence on urinary mutagenicity is unclear. We investigated associations between exposure to CCE or DEE and urinary mutagenicity. In two separate cross-sectional studies of nonsmokers, organic extracts of urine were evaluated for mutagenicity levels using strain YG1041 in the Salmonella (Ames) mutagenicity assay. First, we compared levels among 10 female bituminous (smoky) coal users from Laibin, Xuanwei, China, and 10 female anthracite (smokeless) coal users. We estimated exposure-response relationships using indoor air concentrations of two carcinogens in CCE relevant to lung cancer, 5-methylchrysene (5MC), and benzo[a]pyrene (B[a]P). Second, we compared levels among 20 highly exposed male diesel factory workers and 15 unexposed male controls; we evaluated exposure-response relationships using elemental carbon (EC) as a DEE-surrogate. Age-adjusted linear regression was used to estimate associations. Laibin smoky coal users had significantly higher average urinary mutagenicity levels compared to smokeless coal users (28.4 ± 14.0 SD vs. 0.9 ± 2.8 SD rev/ml-eq, p = 2 × 10-5 ) and a significant exposure-response relationship with 5MC (p = 7 × 10-4 ). DEE-exposed workers had significantly higher urinary mutagenicity levels compared to unexposed controls (13.0 ± 10.1 SD vs. 5.6 ± 4.4 SD rev/ml-eq, p = .02) and a significant exposure-response relationship with EC (p-trend = 2 × 10-3 ). Exposure to CCE and DEE is associated with urinary mutagenicity, suggesting systemic exposure to mutagens, potentially contributing to cancer risk and development at various sites.

First pregnancy in China after ovarian tissue transplantation to prevent premature ovarian insufficiency

OBJECTIVE

This article reports the first case of pregnancy after frozen-thawed ovarian tissue transplantation to prevent iatrogenic premature ovarian insufficiency in China.

METHODS

Ovarian tissue cryopreservation was performed in a patient with myelodysplastic syndrome (MDS) before multi-agent chemotherapy and hematopoietic stem cell transplantation. Two years later, she showed complete remission from MDS, and six frozen-thawed ovarian tissue strips were transplanted into the peritoneal pocket.

RESULTS

The patient's ovarian activity was restored 3 months after transplantation, and pregnancy occurred spontaneously 27 months after grafting. Until now, the pregnancy has progressed for 30 weeks, and the repeated ultrasound showed normal fetal development.

CONCLUSION

This is the first pregnancy resulting from ovarian tissue cryopreservation and transplantation in China.

[Roles of ERK/JNK in carbon black induced AP-1 cell signaling pathway changes]

OBJECTIVE

To investigate the role of ERK/JNK in the alteration of activator protein-1(AP-1) signaling pathway in human embryonic lung fibroblasts(HELFs) induced by carbon black.

METHODS

HELFs were cultured in RPMI 1640 medium containing 0, 15, 30, 60, 120 or 240 μg/mL carbon black for 24 h, and the appropriate dose of carbon black was determined by MTT assay result. HELFs were divided into three groups: HELFs, HELFs transfected with ERK dominant negative mutant plasmid(DN-ERK) and HELFs transfected with JNK dominant negative mutant plasmid(DN-JNK). 100 μg/mL carbon black was used to treat HELFs(CB), DN-ERK HELFs(CB-DN-ERK), DN-JNK HELFs(CB-DN-JNK), and HELFs without any treatment were considered as control group. At 0, 1, 2, 4, 8, 12, 24 and 36 h of CB and control groups HELFs, the western blot was used to detect ERK, p-ERK, JNK, p-JNK, p38, p-p38, c-Jun, p-c-Jun, c-Fos, p-c-Fos protein expression levels, and AP-1 activity was detected by luciferase method. Whereas CB-DN-ERK and CB-DN-JNK HELFs were detected only at 24 h.

RESULTS

Compared with the protein expression levels at 0 h, CB group HELFs ERK and p-ERK protein expression increased at each time point, whereas p38 protein expression decreased. AP-1 activity of CB group HELFs was declined to the lowest at 8 h(0.72±0.12), and upregulated to the peak at 36 h(1.38±0.11). CB group HELFs c-Fos, p-c-Fos and c-Jun protein expression levels at each time point from 1 h to 24 h were greater than those of 0 h, and p-c-Jun protein expression levels at 1 h, 2 h, 4 h, 8 h, 36 h were also greater than those of 0 h. CB group HELFs AP-1 activity, ERK, p-ERK, JNK, p-JNK, p38, p-p38, c-Jun, p-c-Jun, c-Fos, p-c-Fos protein expression levels changes followed biphasic patterns. There were no statistically significant differences in AP-1 activity between CB group HELFs(1.03±0.10) and CB-DN-ERK group(1.02±0.04) or CB-DN-JNK group(1.09±0.10) HELFs(t=0.16, P=0.88; t=0.73, P=0.50). However, compared with CB group HELFs, c-Fos(t=5.31, P=0.01), p-c-Fos(t=4.33, P=0.01), p-c-Jun(t=10.95, P& lt; 0.01)in CB-DN-JNK group, and c-Fos protein expression levels in CB-DN-ERK group(t=42.72, P& lt; 0.01)were significantly decreased.

CONCLUSION

While carbon black induces HELFs increased protein expression levels of ERK, p-ERK, c-Jun, p-c-Jun, c-Fos and p-c-Fos, JNK may upregulate c-Fos, p-c-Fos, p-c-Jun protein expression levels, and ERK may upregulate c-Fos protein expression level.

Abstract 856: Proteomic analysis of serum in workers exposed to diesel engine exhaust

Background: Diesel engine exhaust (DEE) is classified as a Group 1 human carcinogen by the International Agency for Research on Cancer because of its carcinogenicity to the lung. However, the underlying molecular mechanisms of DEE carcinogenicity are not well understood.

Methods: We previously conducted a cross-sectional molecular epidemiology study of diesel engine factory workers exposed to a wide range of DEE and unexposed comparable controls. Here, we carried out a pilot study of a representative subgroup of 19 exposed workers (total n = 54) and 19 unexposed controls (total n = 55). We measured serum level of 1238 targeted proteins using the SOMAScan assay (SOMALogic, Boulder, CA), which measures protein involved in a wide range of biological processes. We used linear regression to identify proteins associated with DEE (permutation p-value &lt;0.01), and examined their exposure-response relationship using a linear trend test across categories of elemental carbon (EC): unexposed (n = 19), lower exposed (median, range: 56.9, 40.2-62.1 µg/m3, n = 9), and higher exposed (median, range: 72.9, 66.9 - 107.7 µg/m3, n = 10), adjusted for age, smoking status, and body mass index. We further assessed correlations of DEE-related proteins with gene expression signature in the nasal epithelium (measured by Affymetrix microarrays) using Pearson's correlation, and examined their pathway enrichment using MetaCore.

Results: Occupational exposure to DEE was significantly associated with altered levels of 22 serum proteins. Of these, 13 proteins (CXCL11, HAPLN1, FLT4, CD40LG, PES1, IGHE.IGK..IGL, TNFSF9, PGD, NAGK, CCL25, CCL4L1, PDXK, and PLA2G1B) showed a significant exposure-response relationship with EC (p-trend &lt;0.01), with serum levels of all but PLA2G1B declining with increasing air levels of EC. For instance, CXCL11 showed the most significant association with DEE (β = -0.25; permutation p-value = 0.00004), where the median serum level of CXCL11 was 35.0 relative fluorescent unit (RFU) among the unexposed compared to 29.7 RFU among the lower exposed and 27.8 RFU among the higher exposed group (p-trend = 0.0005). Furthermore, four DEE-related proteins (CXCL11, PPY, CCL25, and SHH) also showed moderate to strong negative correlations (r = -0.52 to -0.72, all permutation p-values &lt;0.01) with the first principal component of a 225 DEE gene expression signature that we previously reported from nasal epithelial cells. Pathway enrichment analysis suggested that these proteins play a role in immunoregulatory and inflammatory processes, including Th17 cell migration; Th1, Th2, and endothelial cell differentiation; and differentiation and clonal expansion of CD8+ T cells (all FDR &lt;0.05).

Conclusion: Results from our pilot study suggest that DEE exposure is associated with alteration of multiple proteins in the serum, which play a role in inflammation and immune regulation. Analysis of a larger sample size will be needed to confirm our findings.

Citation Format: Mohammad L. Rahman, Yufei Dai, Roel Vermeulen, Wei Hu, Bryan Bassig, Eduard Drizik, Sean Corbett, Dianzhi Ren, Huawei Duan, Yong Niu, Jun Xu, Wei Fu, Kees Meliefste, Baosen Zhou, Xiaohui Zhang, Jufang Yang, Hanqiao Liu, Meng Ye, Gang Liu, Xiaowei Jia, Tao Meng, Ping Bin, Avrum Spira, Marc E. Lenburg, Debra Silverman, Nathaniel Rothman, Yuxin Zheng, Qing Lan. Proteomic analysis of serum in workers exposed to diesel engine exhaust [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 856.

C-peptide enhances glucagon secretion in response to hyperinsulinemia under euglycemic and hypoglycemic conditions

Several studies have associated the presence of residual insulin secretion capability (also referred to as being C-peptide positive) with lower risk of insulin-induced hypoglycemia in patients with type 1 diabetes (T1D), although the reason is unclear. We tested the hypothesis that C-peptide infusion would enhance glucagon secretion in response to hyperinsulinemia during euglycemic and hypoglycemic conditions in dogs (5 male/4 female). After a 2-hour basal period, an intravenous (IV) infusion of insulin was started, and dextrose was infused to maintain euglycemia for 2 hours. At the same time, an IV infusion of either saline (SAL) or C-peptide (CPEP) was started. After this euglycemic period, the insulin and SAL/CPEP infusions were continued for another 2 hours, but the glucose was allowed to fall to approximately 50 mg/dL. In response to euglycemic-hyperinsulinemia, glucagon secretion decreased in SAL but remained unchanged from the basal period in CPEP condition. During hypoglycemia, glucagon secretion in CPEP was 2 times higher than SAL, and this increased net hepatic glucose output and reduced the amount of exogenous glucose required to maintain glycemia. These data suggest that the presence of C-peptide during IV insulin infusion can preserve glucagon secretion during euglycemia and enhance it during hypoglycemia, which could explain why T1D patients with residual insulin secretion are less susceptible to hypoglycemia.

The role of HMGB1 on TDI-induced NLPR3 inflammasome activation via ROS/NF-κB pathway in HBE cells

To explore the potential role of HMGB1 on TDI-induced NLRP3 inflammasome activation, HBE cells were treated with TDI-HSA conjugate to observe the changes of HMGB1, TLR4, NF-κB, Nrf2 and NLRP3 inflammasome related proteins expressions, ROS release and MMP. NAC, TPCA-1 and Resatorvid pre-treatments were applied to explore the effects of ROS, NF-κB and TLR4 on TDI-induced NLRP3 inflammasome activation. The CRISPR/Cas9 system was used to construct HMGB1 gene knockout HBE cell line and then to explore the role of HMGB1 on TDI-HSA induced NLRP3 inflammasome activation. GL pre-treatment was applied to further confirm the role of HMGB1. Results showed that TDI increased HMGB1, TLR4, P-p65, Nrf2 proteins expressions and ROS release, decreased MMP level and activated NLRP3 inflammasome in HBE cells in a dose dependent manner. NAC, TPCA-1 and Resatorvid pre-treatments decreased the expression of P-p65 and inhibited NLRP3 inflammasome activation. Inhibition of HMGB1 decreased Nrf2 expression and ROS release, improved MMP level and reduced NLRP3 inflammasome activation. GL ameliorated NLRP3 inflammasome activation via inhibiting HMGB1 regulated ROS/NF-κB pathway. These results indicated that HMGB1 was involved in TDI-induced NLRP3 inflammasome activation as a positive regulatory mechanism. The study provided a potential target for early prevention and treatment of TDI-OA.

Copper stimulates neonicotinoid insecticide thiacloprid degradation by Ensifer adhaerens TMX-23

AIMS

Aims of this study are to elucidate the molecular mechanism of copper-improved thiacloprid (THI) degradation by Ensifer adhaerens TMX-23 and characterize copper resistance of this strain.

METHODS AND RESULTS

Resting cells of E. adhaerens TMX-23 were used to degrade THI, with formation of THI amide and 98·31% of 0·59 mmol l^-1 THI was degraded in 100 min. The addition of copper improved the degradation of THI and showed little inhibitory effects on the growth of E. adhaerens TMX-23. E. adhaerens TMX-23 degraded THI to THI amide by nitrile hydratases (NhcA and NhpA). QPCR analysis indicated that the expression of nhpA was up-regulated in the presence of copper. E. adhaerens TMX-23 nitrile hydratases were purified, and enzyme assay of NhpA exhibited the highest NHase activity toward THI. The addition of copper activated the activity of NhcA. Soil degradation experiment indicated that E. adhaerens TMX-23 could quickly eliminate THI residual in copper-added soil.

CONCLUSIONS

Copper improved THI degradation by E. adhaerens TMX-23 was attributed to the induced expression of nhpA and activated NhcA.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study broadens the investigation of regulatory mechanism of NHase expression and provided theoretical basis for using metal-resistant microbes to degrade pesticide in heavy metal co-contaminated environments.

Elevated Alu retroelement copy number among workers exposed to diesel engine exhaust

BACKGROUND

Millions of workers worldwide are exposed to diesel engine exhaust (DEE), a known genotoxic carcinogen. Alu retroelements are repetitive DNA sequences that can multiply and compromise genomic stability. There is some evidence linking altered Alu repeats to cancer and elevated mortality risks. However, whether Alu repeats are influenced by environmental pollutants is unexplored. In an occupational setting with high DEE exposure levels, we investigated associations with Alu repeat copy number.

METHODS

A cross-sectional study of 54 male DEE-exposed workers from an engine testing facility and a comparison group of 55 male unexposed controls was conducted in China. Personal air samples were assessed for elemental carbon, a DEE surrogate, using NIOSH Method 5040. Quantitative PCR (qPCR) was used to measure Alu repeat copy number relative to albumin (Alb) single-gene copy number in leucocyte DNA. The unitless Alu/Alb ratio reflects the average quantity of Alu repeats per cell. Linear regression models adjusted for age and smoking status were used to estimate relations between DEE-exposed workers versus unexposed controls, DEE tertiles (6.1-39.0, 39.1-54.5 and 54.6-107.7 µg/m³) and Alu/Alb ratio.

RESULTS

DEE-exposed workers had a higher average Alu/Alb ratio than the unexposed controls (p=0.03). Further, we found a positive exposure-response relationship (p=0.02). The Alu/Alb ratio was highest among workers exposed to the top tertile of DEE versus the unexposed controls (1.12±0.08 SD vs 1.06±0.07 SD, p=0.01).

CONCLUSION

Our findings suggest that DEE exposure may contribute to genomic instability. Further investigations of environmental pollutants, Alu copy number and carcinogenesis are warranted.

Immunotherapy-Related Autoimmune Diabetes Mellitus and Exogenous Insulin Antibody Syndrome in a Patient With Metastatic Oral Squamous Cell Carcinoma

Introduction: Exogenous insulin antibody syndrome (EIAS) is a rare condition characterized by wide glycemic excursions and recurrent hypoglycemia in the presence of high insulin antibody titers. It has been described in diabetic patients treated with exogenous insulin. Programmed death ligand 1 (PD-L1) inhibitors are known to cause autoimmune diabetes mellitus, but PD-L1-related EIAS has not yet been reported to our best knowledge. Case Description: A 63 years old Caucasian man with history of recurrent oral squamous cell cancer presented to emergency room with polyuria, polydipsia, nausea, and vomiting 3 months after initiation of immunotherapy (Durvalumab and cetuximab). He had no prior history of diabetes mellitus or hypoglycemia. He was admitted to hospital for management of diabetic ketoacidosis (Anion gap of 24 mEq/L, venous blood glucose of 805 mg/dL, Venous PH of 7.12, large urine ketone, A1C of 8.9%). After a brief hospital stay, the patient was discharged home on insulin glargine and metformin. His immunotherapy was resumed after hospital discharge. When the patient was seen by Endocrinologist in the clinic, metformin was discontinued and prandial insulin lispro was added. This basal-bolus insulin regimen improved his glycemic control initially. However, without significant changes in his lifestyle or medical condition, he developed worsening postprandial hyperglycemia and recurrent fasting hypoglycemia. Up-titration of his mealtime insulin did not lower postprandial hyperglycemia but possibly worsened fasting hypoglycemia. EIAS was suspected after reviewing his continuous glucose monitoring data. Further work up at this point revealed mildly elevated glutamic acid decarboxylase antibodies (5.9 units/mL, normal range 0.5 - 5.0) and markedly elevated insulin antibody level (77.0 µU/mL, normal range <5). His blood C-peptide was undetectable when his venous blood glucose was 252 mg/dl. In addition, his total insulin level (198 uU/mL) was much higher than his free insulin level (38 uU/mL) following an insulin lispro injection. The patient was diagnosed with EIAS. Switching insulin lispro to insulin aspart while he was on a different immunotherapy medication (Pembrolizumab) immediately reduced his average blood glucose and reduced his total daily insulin dosage by more than 50%. This improvement in glycemic control with insulin aspart only lasted for about 1 week. Unfortunately, the patient’s squamous cancer progressed on immunotherapy. He was referred to hospice care and passed away. Conclusion: Evaluation for EIAS would be reasonable in insulin-treated diabetic patients who develop wide glucose excursions and unexplained fasting hypoglycemia while on immunotherapy.

QSPR modelling for intrinsic viscosity in polymer-solvent combinations based on density functional theory

Linear and nonlinear quantitative structure-property relationship (QSPR) models were developed based on a dataset with 65 polymer-solvent combinations. Seven quantum chemical descriptors, dipole moment, hardness, chemical potential, electrophilicity index, total energy, HOMO and LUMO orbital energies, were calculated with density functional theory at the B3LYP/6-31 G(d) level for polymers and solvents. Considering the strong correlation between intrinsic viscosity and weight, size, shape as well as topological structure of polymers and solvents, topological descriptors were also applied in this work. Meanwhile, the most appropriate polymer structure representation was investigated by considering 1-5 monomeric repeating units. The molecular descriptors were first screened by using the genetic algorithms-multiple linear regression (GA-MLR), with coefficient of determinations (r2) of 0.78 and 0.83 for the training set and the prediction set, respectively. The support vector machine model (SVM) model based on the selected descriptors subset showed a r2 value of 0.95 for the training set and 0.93 for the prediction set. All statistical results suggest that the established QSPR models have good predictability. Furthermore, a new test set obtained from the literature was used for further validation. The r2 values were 0.81 for the MLR model and 0.90 for the SVM model.

Liver glycogen-induced enhancements in hypoglycemic counterregulation require neuroglucopenia

Iatrogenic hypoglycemia is a prominent barrier to achieving optimal glycemic control in patients with diabetes, in part due to dampened counterregulatory hormone responses. It has been demonstrated that elevated liver glycogen content can enhance these hormonal responses through signaling to the brain via afferent nerves, but the role that hypoglycemia in the brain plays in this liver glycogen effect remains unclear. During the first 4 h of each study, the liver glycogen content of dogs was increased by using an intraportal infusion of fructose to stimulate hepatic glucose uptake (HG; n = 13), or glycogen was maintained near fasting levels with a saline infusion (NG; n = 6). After a 2-h control period, during which the fructose/saline infusion was discontinued, insulin was infused intravenously for an additional 2 h to bring about systemic hypoglycemia in all animals, whereas brain euglycemia was maintained in a subset of the HG group by infusing glucose bilaterally into the carotid and vertebral arteries (HG-HeadEu; n = 7). Liver glycogen content was markedly elevated in the two HG groups (43 ± 4, 73 ± 3, and 75 ± 7 mg/g in NG, HG, and HG-HeadEu, respectively). During the hypoglycemic period, arterial plasma glucose levels were indistinguishable between groups (53 ± 2, 52 ± 1, and 51 ± 1 mg/dL, respectively), but jugular vein glucose levels were kept euglycemic (88 ± 5 mg/dL) only in the HG-HeadEu group. Glucagon and epinephrine responses to hypoglycemia were higher in HG compared with NG, whereas despite the increase in liver glycogen, neither increased above basal in HG-HeadEu. These data demonstrate that the enhanced counterregulatory hormone secretion that accompanies increased liver glycogen content requires hypoglycemia in the brain.NEW & NOTEWORTHY It is well known that iatrogenic hypoglycemia is a barrier to optimal glycemic regulation in patients with diabetes. Our data confirm that increasing liver glycogen content 75% above fasting levels enhances hormonal responses to insulin-induced hypoglycemia and demonstrate that this enhanced hormonal response does not occur in the absence of hypoglycemia in the brain. These data demonstrate that information from the liver regarding glycogen availability is integrated in the brain to optimize the counterregulatory response.

The transcription factors of tall fescue in response to temperature stress

Tall fescue (Festuca arundinacea) is an important grass species worldwide, but temperature stress severely affects its distribution and yield. Transcription factors (TFs), as the master switches in sophisticated regulatory networks, play essential roles in plant growth development and abiotic stress responses. In this study, the comparative transcriptome analysis was performed to explore the commonalities and differences in the response of TFs to the heat (40 °C), cold (10 °C) and control (22 °C) conditions. A total of 877 TF genes belonging to 35 families were identified. Most of them (784) were differentially expressed genes (DEG), indicating TF genes actively responded to temperature stress. The expression of bZIP and GTF family members was up-regulated when exposed to both heat and cold, but conversely, the expression of the most WRKY and NAC families members decreased. The HSF and GTE families and DREB2B were up-regulated upon heat, while bHLH, MYB, HD-ZIP and ERF families were elevated under cold stress. The TFs involved in 'Plant hormone signal transduction', 'Plant-pathogen interaction', 'Circadian rhythm' play major roles in responding to temperature stresses. The results showed the temperature threats up-regulated the expression of stress tolerance-related genes, and down-regulated those genes associated with growth and disease resistance, indicating TFs exert crucial roles in plant adaptation to an adverse environment. This study profiled the responsive pattern of TFs to temperature stresses, partially explained the mechanism of adaptations of cold-season forage crops and screened many candidate stress-tolerant TF genes.

Assisted reproductive technology service availability, efficacy and safety in mainland China: 2016

STUDY QUESTION

What is the current status of assisted reproductive technology (ART) service availability, efficacy and safety in mainland China?

SUMMARY ANSWER

In this first national report on ART status in mainland China, data on treatment numbers, outcomes and complications in 2016 are provided and analyzed, respectively.

WHAT IS KNOWN ALREADY

National ART Service Provision Surveys are conducted in mainland China regularly. Data were analyzed, and this manuscript was written by team members from the National Center for Women and Children's Health, China CDC and the Department of Women and Children Health, National Health Commission of the People's Republic of China.

STUDY DESIGN, SIZE AND DURATION

A cross-sectional nationwide survey was completed in 2018, in which data regarding ART treatments, performed from 1st January to 31st December2016 in 445 ART clinics located in 31 provinces of mainland China, were collected.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

There were in total 451 licensed ART clinics (including artificial insemination clinics) in mainland China in 2016, of which 445 submitted service data. A total of 906 840 cycles were provided by 323 in vitro fertilization (IVF) clinics, involving 375 770 conventional IVF cycles, 154 948 intracytoplasmic sperm injection (ICSI) cycles, 367 146 frozen embryo transfer (FET) thawing cycles and 8976 preimplantation genetic diagnosis (PGD) treatment cycles. A total of 161 376 artificial (i.e. intrauterine) insemination (AI) cycles were reported by 443 clinics, with 126 872 cycles using the husband's semen (AIH) and 34 504 using donor semen (AID).

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 98.7% of the licensed clinics, contributing to 100% of the ART services (including AID and AIH cycles), were included in this report. (Six clinics provided institutional information only and were excluded.) There were 906 840 in vitro fertilization cycles performed in mainland China with a population of over 1.3 billion inhabitants, with cycles per million inhabitants (C/M) increasing from 360 in 2013 to 657 in 2016, nationwide (range among provinces: 45-3676). After treatment with conventional IVF, the clinical pregnancy rate (PR) per oocyte retrieval cycle was 23.2%, the delivery rate (DR) per oocyte retrieval cycle was 18.7% and the proportion of twin delivery among the total deliveries was 27.9%. For ICSI cycles, the PR, DR and TDR were 20.5%, 16.7% and 27.2%, respectively. For FET per thawing cycles, the PR, DR and TDR were 48.2%, 37.6% and 24.2%. For PGD per diagnosis cycles, the PR, DR and TDR were 38.1%, 29.7% and 4.2%. For AIH cycles, the PR and DR were 13.3% and 10.5%; for AID cycles, the PR and DR were 24.3% and 21.1%, respectively. The total number of live infants born in mainland China in 2016, was 18.46 million, and the number of infants born through ART conducted in 2016 was 311 309, which accounted for 1.69% of the total. The reported rate of birth defects was about 87/10 000. The incidence of moderate to severe ovarian hyper-stimulation syndrome (OHSS) was 11.5 per 1000 oocyte retrieval cycles, and other complications were much more rare.

LIMITATIONS AND REASONS FOR CAUTION

This report is based on the summary data of ART services provided. The success rates were not calculated by age stratification. A low rate of birth defects was reported, which might be confounded by variations in birth follow-up methods, statistical timing and record taking.

WIDER IMPLICATIONS OF THE FINDINGS

ART service availability has improved significantly in recent years in mainland China. Because China is a vast country, significant imbalances in ART service provision do exist; however, the main efficacy and safety indicators were close to those of western countries.

TRIAL REGISTRATION NUMBER

N/A.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the National Key R&D Program of China (2016YFC1000307-2). There are no competing interests.

Genetic structure of the endangered Irrawaddy dolphin (Orcaella brevirostris) in the Gulf of Thailand

The Irrawaddy dolphin (Orcaella brevirostris) is an endangered, small cetacean species which is widely distributed in rivers, estuaries, and coastal waters throughout the tropical and subtropical Indo-Pacific. Despite the extensive distribution of this species, little is known of individual movements or genetic exchange among regions in Thailand. Here, we evaluate the genetic diversity and genetic structure of O. brevirostris in the eastern, northern and western Gulf of Thailand, and Andaman Sea. Although phylogenetic relationships and network analysis based on 15 haplotypes obtained from 32 individuals reveal no obvious divergence, significant genetic differentiation in mitochondrial DNA (overall FST = 0.226, P < 0.001; ΦST = 0.252, P < 0.001) is apparent among regions. Of 18 tested microsatellite loci, 10 are polymorphic and successfully characterized in 28 individuals, revealing significant genetic differentiation (overall FST = 0.077, P < 0.05) among the four sampling sites. Structure analysis reveals two inferred genetic clusters. Additionally, Mantel analysis demonstrates individual-by-individual genetic distances and geographic distances follow an isolation-by-distance model. We speculate that the significant genetic structure of O. brevirostris in Thailand is associated with a combination of geographical distribution patterns, environmental and anthropogenic factors, and local adaptations.

Early divergence and differential population histories of the Indo-Pacific humpback dolphin in the Pacific and Indian Oceans

The currently recognized Indo-Pacific humpback dolphin occurs in estuaries and surrounding shallow waters from the South China Sea to the Asian coast of the Indian Ocean. However, a recent study suggested that the humpback dolphin from the Bay of Bengal may represent a distinct phylogenetic species. In this study, we sequenced 915-bp mtDNA segments from five geographic populations in both Chinese and Thai waters; together with previously published sequences, these data revealed that the ancestral Indo-Pacific humpback dolphin might have split during the transition from the Oligocene to Miocene (23.45 Mya, 95% HPD: 16.65-26.55 Mya), and then dispersed along the Pacific and Indian Ocean coasts of Asia. Genetic differentiation was detected between most of the examined populations, except for only a few pairwise populations in the northern South China Sea. Genetic differentiation/distance between the humpback dolphins from the northern and southern South China Sea met the sub-species threshold value proposed for marine mammals, whereas that between the humpback dolphins in the Pacific and the Indian Ocean was above the species threshold. Bayesian inference of historic gene flow indicated low but constant northward gene flow along the Indian Ocean coast; however, there was a recent abrupt increase in gene flow in the Pacific region, likely due to the shortening coastline at the low stand of sea level. Our results revealed that the current taxonomic classification of Indo-Pacific humpback dolphins may not reflect their phylogeography.

Evaluation of pulmonary ventilation in COVID-19 patients using oxygen-enhanced three-dimensional ultrashort echo time MRI: a preliminary study

AIM

To evaluate the lung function of coronavirus disease 2019 (COVID-19) patients using oxygen-enhanced (OE) ultrashort echo time (UTE) MRI.

MATERIALS AND METHODS

Forty-nine patients with COVID-19 were included in the study. The OE-MRI was based on a respiratory-gated three-dimensional (3D) radial UTE sequence. For each patient, the percent signal enhancement (PSE) map was calculated using the expression PSE = (S_100% – S_21%)/S_21%, where S_21% and S_100% are signals acquired during room air and 100% oxygen inhalation, respectively. Agreement of lesion detectability between UTE-MRI and computed tomography (CT) was performed using the kappa test. The Mann–Whitney U-test was used to evaluate the difference in the mean PSE between mild-type COVID-19 and common-type COVID-19. Spearman's test was used to assess the relationship between lesion mean PSE and lesion size. Furthermore, the Mann–Whitney U-test was used to evaluate the difference in region of interest (ROI) mean PSE between normal pulmonary parenchyma and lesions. The Kruskal–Wallis test was applied to test the difference in the mean PSE between different lesion types.

RESULTS

CT and UTE-MRI reached good agreement in lesion detectability. Ventilation measures in mild-type patients (5.3 ± 5.5%) were significantly different from those in common-type patients (3 ± 3.9%). Besides, there was no significant correlation between lesion mean PSE and lesion size. The mean PSE of COVID-19 lesions (3.2 ± 4.9%) was significantly lower than that of the pulmonary parenchyma (5.4 ± 3.9%). No significant difference was found among different lesion types.

CONCLUSION

OE-UTE-MRI could serve as a promising method for the assessment of lung function or treatment management of COVID-19 patients.

[Effect of ERK/JNK cell signaling pathway in carbon black induced cytokine IL-6 and IL-8 expression changes]

OBJECTIVE

To investigate the roles of extracellular signal-regulated kinase(ERK)/c-Jun amino-terminal kinase(JNK) signaling pathway on the expression of interleukin-6(IL-6) and interleukin-8(IL-8) in human embryonic lung fibroblasts(HELF) induced by carbon black.

METHODS

HELFs were cultured in RPMI-1640 medium containing 0, 15, 30, 60, 120 or 240 μg/mL carbon black for 24 h, and the appropriate dose of carbon black was determined by MTT assay result HELFs were divided into three groups: HELFs, HELFs transfected with ERK dominant negative mutant plasmid(DN-ERK) and HELFs transfected with JNK dominant negative mutant plasmid(DN-JNK). 100 μg/mL carbon black was used to treat HELFs(CB), DN-ERK HELFs(CB-DN-ERK), DN-JNK HELFs(CB-DN-JNK), and HELFs without any black carbon treatment were considered as control group. At 16 h after carbon black treatment, scanning electron microscope(SEM) was used to observe HELFs morphology and whether there were carbon black particless. At 0, 1, 2, 4, 8, 12, 24 and 36 h, the enzyme linked immunosorbent assay(ELISA) was used to detect CB and control groups HELFs IL-6 and IL-8 expression levels, whereas CB-DN-ERK and CB-DN-JNK HELFs were detected only at 24 h.

RESULTS

SEM result showed no carbon black particles were observed in CB group HELFs, whereas their surface projections were increased. The CB group HELFs IL-6 expression levels at 2 h(44. 86±3. 65 ng/L) and 4 h(76. 52±3. 15 ng/L) were significantly lower than those of the control group(96. 78±2. 82 and 147. 32±3. 26 ng/L)(P&lt;0. 05), whereas the IL-6 expression levels were significantly higher than those of the control group(105. 54±6. 10, 101. 27±5. 84 and 97. 15±5. 12 ng/L) at 16 h(202. 64±7. 20 ng/L), 24 h(200. 38±6. 20 ng/L) and 36 h(183. 54±4. 54 ng/L)(P&lt;0. 001). At 24 h(136. 75±3. 81 ng/L) and 36 h(149. 12±2. 74 ng/L), the CB group IL-8 expression levels were significantly higher than those of the control group(75. 16±2. 84 and 73. 44±2. 15 ng/L)(P&lt;0. 001). Compared with CB group HELFs, CB-DN-ERK and CB-DN-JNK groups HELFs had significantly lower IL-6 and IL-8 expression levels(P&lt;0. 05).

CONCLUSION

While carbon black induced HELFs IL-6 and IL-8 expression levels changes, ERK and JNK may upregulate IL-6 and IL-8 expression levels.

Ambient particulate matter compositions and increased oxidative stress: Exposure-response analysis among high-level exposed population

BACKGROUND

Oxidative stress has been suggested to be one of the key drivers of health impact of particulate matter (PM). More studies on the oxidative potential of PM alone, but fewer studies have comprehensively evaluated the effects of external and internal exposure to PM compositions on oxidative stress in population.

OBJECTIVE

To comprehensively investigate the exposure-response relationship between PM and its main compositions with oxidative stress indicators.

METHODS

We conducted a cross-sectional study including 768 participants exposed to particulates. Environmental levels of fine particulate matter (PM_2.5), polycyclic aromatic hydrocarbons (PAHs) and metals in PM were measured, and urinary levels of PAHs metabolites and metals were measured as internal dose, respectively. Multivariable linear regression models were used to analyze the correlations of PM exposure and urinary levels of 8-hydroxy-2́'-deoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α) and malondialdehyde (MDA).

RESULTS

The concentration of both PM_2.5 and total PAHs was significantly correlated with increased urinary 8-OHdG, 8-iso-PGF2α and MDA levels (all p < 0.05). The levels of 4 essential metals all showed significant exposure-response increase in urinary 8-OHdG in both current and non-current smokers (all p < 0.05); ambient selenium, cobalt and zinc were found to be significantly correlated with urinary 8-iso-PGF2α (p = 0.002, 0.003, 0.01, respectively); only selenium and cobalt were significantly correlated with urinary MDA (p < 0.001, 0.01, respectively). Furthermore, we found each one-unit increase in urinary total OH-PAHs generated a 0.32 increase in urinary 8-OHdG, a 0.22 increase in urinary 8-iso-PGF2α and a 0.19 increase in urinary MDA (all p < 0.001). Furthermore, it was found that the level of 12 urinary metals all showed significant and positive correlations with three oxidative stress biomarkers in all subjects (all p < 0.001).

CONCLUSIONS

Our systematic molecular epidemiological study showed that particulate matter components could induce increased oxidative stress on DNA and lipid. It may be more important to monitor and control the harmful compositions in PM rather than overall particulate mass.

Polycyclic aromatic hydrocarbons in particulate matter and serum club cell secretory protein change among schoolchildren: A molecular epidemiology study

Airborne particulate matter (PM) is a complex mixture containing various kinds of harmful components. Exposure to air PM is associated with childhood respiratory disease, but epidemiological data are limited concerning the circulating respiratory injury protein on the etiology of childhood respiratory disease. Specifically, the role of PM toxic components or its biological effective dose (adduct) in respiratory injury remains unclear. To demonstrate the dose-response relationship and the main mechanism on circulating club cell secretory protein (CC16) from PM compositions among children, we enrolled 273 boarding schoolchildren in China, including 110 and 163 children of whom were in the low- and high-PM exposed areas, respectively. In this study, we measured the internal exposure levels, including serum polycyclic aromatic hydrocarbons (PAH) adduct, urinary metals, and AhR expression, and detected the serum CC16 level as a lung injury marker. Environmental tobacco exposure in children was assessed by urinary cotinine. We found that significantly higher levels of serum CC16, benzo[a]pyridin-7,8-dihydroglycol-9,10-epoxide (BPDE)-albumin adduct, urinary molybdenum, selenium, arsenic, cadmium and barium, and lower level of AhR expression in high-PM exposed group. There was a good association between serum BPDE-albumin adduct and CC16 (β = 0.222, P = 0.006). There was no association on urinary metals and serum CC16. BPDE-albumin adduct was directly associated with serum CC16 alternation [direct effect = 0.2044, 95% confidence interval (CI) = (0.0426, 0.36)]. PM could cause serum CC16 increased in children. PAH and its adduct might play a key role in lung injury during PM exposure.

The Prevalence and Negative Effects of Thoracic Hyperkyphosis on Chinese Community-Dwelling Older Adults in Wuhan, Hubei Province, China

BACKGROUND

Globally, 20% to 50% older adults have been found to have thoracic hyperkyphosis. Negative effects on physical performance have been reported. However, there has been a lack of research on the prevalence and negative effects of thoracic hyperkyphosis among Chinese community-dwelling elderly.

DESIGN

A cross-sectional study.

SETTING

The communities in Wuhan, China.

PARTICIPANTS

Three hundred and ninety-five Chinese community-dwelling older adults with thoracic hyperkyphosis.

MEASURES

Chinese community-dwelling older adults aged 60 or above lived in Wuhan, China from August to December 2018 were recruited for spine and physical performance assessments. The primary outcome was the prevalence of thoracic hyperkyphosis estimated according to the angle of kyphosis which was measured by manual inclinometers. The secondary outcomes were the effects of thoracic hyperkyphosis on physical performance measured by One-leg Standing Test (OLS), Timed Up AND Go Test (TUG), Chest Expansion Test (CE), Six Minutes Walking Test (6MWT), and Farsi Version of Functional Gait Assessment (FGA). The socio-demographic and health-related information were collected by a questionnaire.

RESULTS

Among 395 participants, the mean angle of kyphosis was 49.0° ± 10.5°, 75.2% of participants had the angle of kyphosis >40° (i.e., having thoracic kyperkyphosis). Compared with older adults having no thoracic hyperkyphosis, older adults with thoracic hyperkyphosis had increased risks performing impaired in OLS (OR=4.55, 95% CI 2.18-9.53, p<0.001), TUG (OR=6.08, 95% CI 2.57-14.40, p<0.001), CE (OR=3.23, 95% CI 1.63-6.38, p=0.001), 6MWT (OR=4.64, 95% CI 1.98-10.86, p<0.001), and FGA (OR=5.18, 95% CI 2.25-11.89, p<0.001) after controlling socio-demographic and health-related factors.

CONCLUSION

The thoracic hyperkyphosis had high prevalence and associated with impaired performance in balance, gait, and cardiopulmonary function tests among Chinese community-dwelling older adults, which calls for the future intervention.

Effect of alprostadil on myocardial fibrosis in rats with diabetes mellitus via TGF-β1/Smad signaling pathway

OBJECTIVE

To observe the influence of alprostadil on myocardial fibrosis in rats with diabetes mellitus (DM) through the transforming growth factor beta-1 (TGF-β1)/Smad signaling pathway.

MATERIALS AND METHODS

Wistar rats were employed to induce models of DM (DM group), and alprostadil treatment group (ALPR group) and control group (NC group) were set up. After successful modeling, blood and myocardial tissues were collected from rats. Next, blood glucose level, liver function, and myocardial function were detected. In addition, hematoxylin-eosin (HE) assay was performed to determine pathological changes. The enzyme-linked immunosorbent assay (ELISA) was carried out to measure serum interleukin-6 (IL-6) and cardiac function indexes such as ejection fraction (EF), Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Western blotting, which were applied to measure the gene and protein expression levels of important molecules in the proliferation and differentiation of myocardial fibroblasts [including checkpoint kinase 1 (Chek1) and alpha-smooth muscle actin (α-SMA)] and the relevant pathway TGF-β1/Smad2.

RESULTS

The blood glucose level was increased in DM group (p<0.01), suggesting that modeling is successful. The tumor necrosis factor-alpha (TNF-α), IL⁃6, and IL-1 levels were higher in DM group than in NC group. DM group had significantly elevated serum content of alkaline phosphatase (ALP), alanine aminotransferase (ALT), and creatine kinase (CK), as well as left ventricular end-diastolic dimension (LVEDd) and left ventricular end-systolic dimension (LVESd), but it clearly decreased fractional shortening (FS) and EF in comparison with NC group. Besides, myocardial cells were orderly arranged in NC group, while myocardial fibrosis was observed in DM group. The results of RT-PCR showed that the levels of Collagen, Chek1, α-SMA, TGF-β1, and Smad2 in myocardial fibroblasts were notably lowered in ALPR group, but evidently increased in DM group (p<0.05). According to Western blotting, there were evident decreases in the levels of TGF-β1 and Smad2 in myocardial fibroblasts in ALPR group (p<0.05). The above results suggest that alprostadil represses the expression of the TGF-β1/Smad2 signaling pathway and its relevant molecules, thus further suppressing the fibrosis of myocardial cells.

CONCLUSIONS

Alprostadil treats myocardial fibrosis in DM rats by inhibiting the TGF-β1/Smad2 signaling pathway.

MicroRNA-135 inhibits gastric cancer metastasis by targeting SMAD2

OBJECTIVE

The purpose of this study was to investigate whether microRNA-135 plays a role in the malignant progression of gastric cancer (GC) by regulating SMAD2 and its underlying mechanism.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine microRNA-135 expression in tumor tissue specimens and paracancerous ones of 28 patients with GC, and the interplay between microRNA-135 level and clinical indexes and prognosis of GC patients was also analyzed. Subsequently, when negative control (NC) sequence or microRNA-135 mimics were transfected into GC cell lines, Cell Counting Kit-8 (CCK-8), transwell and wound healing assays were used to analyze the impact of microRNA-135 on proliferation and apoptosis of GC cells. Finally, the mechanism of microRNA-135 on the downstream gene SMAD2 was explored by a cell recovery experiment.

RESULTS

QRT-PCR results revealed that in tumor tissues of GC patients, the microRNA-135 level was conspicuously lower than that in the adjacent tissues, and the difference was statistically significant. The overall survival rate was lower in patients with low expression of microRNA-135 compared with patients with a high one. In addition, in the GC cell lines including BGC-823 and SGC-7901, the cell proliferation, as well as invasion and migration ability of microRNA-135 mimics group, was significantly decreased compared with the NC group. Moreover, the research verified that SMAD2 expression in GC cell lines and tissues was markedly increased and negatively correlated with microRNA-135 level. The cell recovery study found that overexpression of SMAD2 can offset the influence of microRNA-135 mimics on proliferation and metastasis of GC cells, thus affecting the malignant progression of GC.

CONCLUSIONS

In this work, microRNA-135 was found conspicuously associated with lymph node or distant metastasis and poor prognosis of GC patients. Additionally, microRNA-135 may inhibit the malignant progression of GC by targeted regulating SMAD2 expression.

Evaluation of an accelerated 3D modulated flip-angle technique in refocused imaging with an extended echo-train sequence with compressed sensing for imaging of the knee: comparison with routine 2D MRI sequences

AIM

To accelerate the acquisition of high-resolution magnetic resonance imaging (MRI) by using the three-dimensional (3D) matrix sequence with compressed sensing and to compare it with conventional two-dimensional (2D) proton-density (PD) and fast spin-echo (FSE) sequences.

MATERIALS AND METHODS

3D matrix, 2D FSE, and PD sequences were acquired from 68 participants using 3 T magnetic resonance imaging (MRI). Two radiologists scored image quality independently on a four-point scale. The structural similarity index (SSIM), and signal- (SNRs) and contrast-to-noise ratios (CNRs) of different anatomical structures of the knee were assessed and compared between sequences using Wilcoxon signed-rank tests and Cohen's kappa.

RESULTS

The median acquisition time reduction was 44.5%. There was a substantial to perfect agreement for the rating between the 3D matrix FSE and 2D FSE or PD sequences when evaluating cartilage, subchondral bone, and ligaments (κ=0.783-872, p>0.05). The mean SSIM values between the 3D matrix FSE and 2D FSE, and between the 3D matrix PD and 2D PD sequences was 0.994 and 0.971, respectively, which are acceptable. No significant differences were found in SNR between the 3D matrix FSE and 2D FSE, and between the 3D matrix PD and 2D PD sequences, even though the SNR appeared to be higher on routine 2D sequences. The CNR of subchondral bone-meniscus, subchondral bone-joint fluid, and meniscus-joint fluid did not differentiate significantly between the 3D matrix sequence and routine 2D sequences.

CONCLUSIONS

3D matrix reduced the acquisition time in routine clinical knee MRI without the loss in image quality, SNR, and CNR.

[Establishment of a nucleic acid assay for detection of Echinococcus granulosus based on recombinase-aided isothermal amplification assay]

OBJECTIVE

To establish a nucleic acid assay for detection of Echinococcus granulosus based on recombinase-aided isothermal amplification (RAA) assay.

METHODS

The 12S rRNA gene of E. granulosus was selected as the target gene, and the specific primers and fluorescent probes for RAA assay were designed, screened and synthesized to establish a fluorescent RAA assay for detection of E. granulosus. The sensitivity of the fluorescent RAA assay was evaluated using different copy numbers of target gene sequence-contained recombinant plasmids and various concentrations of E. granulosus genomic DNA as templates, and the specificity of the fluorescent RAA assay was evaluated using the genomic DNA from E. granulosus, E. multilocularis, Schistosoma japonicum, S. mansoni, Ancylostoma duodenale, Clonorchis sinensis, Taenia saginata, Spirometra mansoni and Taenia solium as templates.

RESULTS

A fluorescent RAA assay was successfully established for detection of E. granulosus, which achieved specific amplification of E. granulosus genomic DNA within 20 min at 39 ℃. The lowest detection limit of the fluorescent RAA assay was 10 copies/μL of recombinant plasmids and 0.1 ng/μL E. granulosus genomic DNA, which exhibited a high sensitivity, and the fluorescent RAA assay was all negative for the genomic DNA from E. multilocularis, S. japonicum, S. mansoni, A. duodenale, C. sinensis, T. saginata, Spirometra mansoni and T. solium, which exhibited a high specificity. In addition, this fluorescent RAA assay successfully detected genomic DNA from E. granulosus cysts.

CONCLUSIONS

A rapid, sensitive and specific fluorescent RAA assay is successfully established for nucleic acid detection of E. granulosus.

[Establishment of a recombinase-aided isothermal amplification assay for nucleic acid detection of Angiostrongylus cantonensis]

OBJECTIVE

To establish a recombinase-aided isothermal amplification (RAA) assay for the nucleic acid detection of Angiostrongylus cantonensis.

METHODS

The internal transcribed spacer-1 (ITS1) gene sequence of A. cantonensis was used as the detection target sequence, and the specific primers and probes were designed and synthesized, followed by screening of the primers and probes with the highest specificity, to establish the basic and fluorescent RAA assay for nucleic acid detection of A. cantonensis. The sensitivity of the fluorescent RAA assay was evaluated by using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the template DNA samples, and the specificity of the fluorescent RAA assay was evaluated by using the genomic DNA from A. cantonensis, Schistosoma mansoni, Ascaris lumbricoides, Clonorchis sinensis, Echinococcus granulosus and Ancylostoma duodenale, as well as Pomacea canaliculata and Biomphalaria straminea snail tissues as the template DNA samples.

RESULTS

A fluorescent RAA assay was successfully established for nucleic acid detection of A. cantonensis, which achieved real-time amplification of the specific DNA fragment of A. cantonensis within 20 min at 37 ℃. By using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the DNA templates, the lowest detection limits of the fluorescent RAA assay were 10 copies/μL of recombinant plasmids and 100 pg/μL of genomic DNA, respectively. The fluorescent RAA assay was negative for detection of the genomic DNA from A. cantonensis, S. mansoni, A. lumbricoides, C. sinensis, E. granulosus, A. duodenale, and P. canaliculata and B. straminea snail tissues.

CONCLUSIONS

A simple, rapid fluorescent RAA assay has been successfully established, which has a high sensitivity and specificity for the nucleic acid detection of A. cantonensis.

[Polarization of human acute monocytic leukemia THP-1 cells-derived macprophages induced by Nippostrongylus brasiliensis proteins in vitro]

OBJECTIVE

To investigate the polarization of human acute monocytic leukemia THP-1 cells-derived macrophages induced by Nippostrongylus brasiliensis proteins in vitro, so as to provide insights into the elucidation of the mechanisms underlying host immune responses to hookworm infections.

METHODS

The in-vitro culture of N. brasiliensis was established and maintained in the laboratory, and the third- (L3) and fifth-stage larvae (L5) were collected under a sterile condition for preparation of L3 and L5 proteins. The in-vitro culture of THP-1 cells was established, stimulated with 500 ng/mL PMA to yield M0 macrophages that were adherent to the plate wall. The LPS + IFN-γ group, IL-4 + IL-13 group, L3 protein group and L5 protein group were given stimulation with 500 ng/mL LPS plus 100 ng/mL IFN-γ, IL-4 and IL-13 (both 100 ng/mL), L3 protein (5 mg/mL) and L5 protein (5 mg/mL), respectively, while the negative control group was given no stimulation. The cell morphology was observed using microscopy, the mRNA expression of M1/M2 macrophages-specific genes was quantified using a quantitative real-time PCR (qPCR) assay, and the surface markers of M1/M2 macrophages were detected using flow cytometry, while the levels of cytokines secreted by M1/M2 macrophages were measured using enzyme-linked immunosorbent assay (ELISA) following stimulations, so as to examine the polarization of THP-1-derived macrophages induced by N. brasiliensis proteins in vitro.

RESULTS

Following stimulation with PMA, THP-1 cells appeared wall-adherent M0 macrophages, and polarized to typical M1 macrophages following stimulation with LPS + IFN-γ, and typical M2 macrophages following stimulation with IL-4 + IL-13, IL-3 protein or L5 protein. There was a significant difference in the proportion of M1 macrophages among the negative control group, the LPS + IFN-γ group, the IL-4 + IL-13 group, the L3 protein group and the L5 protein group (χ² = 3 721.00, P < 0.001), with the highest proportion detected in the LPS + IFN-γ group, and there was also a significant difference in the proportion of M2 macrophages among groups (χ² = 105.43, P < 0.001). There were significant differences among groups in terms of the mRNA expression of CCL2 (F = 191.95, P < 0.001), TNF-α (F = 129.95, P < 0.001), IL-12b (F = 82.89, P < 0.001), PPARγ (F = 11.30, P < 0.001), IL-10 (F = 9.51, P < 0.001) and Mrc1 genes (F = 12.35, P < 0.001). In addition, there were significant differences in the proportion of positive CD86 and CD206 expression among groups (χ² = 24 004.33 and 832.50, P < 0.001). Higher IL-1β and TNF-α levels were measured in the LPS + IFN-γ group than in the IL-4 + IL-13 group, the L3 protein group and the L5 protein group (P < 0.001), and greater TGF-β1 and IL-10 levels were seen in the IL-4 + IL-13 group, the L3 protein group and the L5 protein group than in the negative control group and the LPS + IFN-γ group (P < 0.05).

CONCLUSIONS

Both L3 and L5 proteins of N. brasiliensis may induce the polarization of THP-1-derived macrophages to M2 type in vitro.

[The effects and immunologic mechanisms of Helicobacter pylori infection on AOM/DSS induced colitis-associated cancer in mice]

Objective: To investigate the effects and potential mechanisms of Helicobacter pylori (H.pylori) infection on azoxymethane (AOM)/dextran sulfate sulphate (DSS) induced colitis-associated cancer (CAC) in mice. Methods: A total of 60 specific pathogen free C57BL/6J mice were randomly divided into four groups: normal control group (control group, n=9), H. pylori-infected group (Hp group, n=9), AOM/DSS-treated group (AOM/DSS group,n=21) and AOM/DSS-treated with H.pylori infection group (Hp+AOM/DSS group, n=21). Mice were sacrificed on day19, 45 or 85 after AOM/DSS challenge. Histopathological changes in colonic tissues were determined by hematoxylin and eosin staining. Flow cytometry analysis was performed to determine T helper cells 17 (Th17) and regulatory T cells (Treg) in colonic lamina propria. The expression levels of Th17-and Treg-associated cytokines and transcription factors [interleukin (IL)-10, IL-17A, retinoic acid receptor-related orphan receptor γt (RORγt) and forkhead box P3 (Foxp3)] were determined by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Results: There were no histopathological changes in colonic tissues of mice in control group and Hp group. H.pylori colonization reduced the histopathological scores at the stages of colitis (day 19) and dysplasia (day 45), and also decreased tumor load (day 85) in mice treated with AOM/DSS (all P<0.05). Compared with AOM/DSS group, the percentages of CD3(+)CD4(+)IL-17A(+)Th17 and CD3(+)CD4(+)IL-17A(+)Foxp3(+)Treg cells (1.88±0.17 vs 2.07±0.89, 1.06±0.13 vs 1.89±0.23) and the expression levels of RORγt and IL-17A (1.08±0.59 vs 2.35±1.35, 2.96±0.92 vs 7.78±4.57) were decreased in colonic tissues of Hp+AOM/DSS group (all P<0.05). The percentages of CD3(+)CD4(+)CD25(+)Foxp3(+)Treg and CD3(+)CD4(+)IL-10(+)Foxp3(+)Treg cells (20.60±3.39 vs 15.63±2.71, 2.94±0.52 vs 2.14±0.47) and the expression levels of Foxp3 and IL-10 [17.59(13.77,24.87) vs 6.27(4.41,13.36), 3.52(1.59,5.99) vs 1.17(1.15,2.75)] in colonic tissues were higher (all P<0.05) in mice of Hp+AOM/DSS group compared with AOM/DSS group on day 85. Conclusion: H.pylori infection slows the progress from inflammation to tumor in a AOM/DSS induced CAC modal, accompanied with the downregulation of Th17 response and upregulation of Treg response.

MiR-431 suppresses proliferation and metastasis of lung cancer via down-regulating DDX5

OBJECTIVE

We aimed to detect the role and function of microRNA-431 (miR-431) in lung cancer, and to investigate the underlying mechanism in regulating the development of lung cancer.

PATIENTS AND METHODS

Quantitative Real-time polymerase chain reaction (qRT-PCR) was utilized to measure the relative expression level of miR-431 in lung cancer tissues and cell lines. Cell counting kit-8 (CCK-8) and colony formation assays were employed to measure the proliferative ability of lung cancer cells. Meanwhile, transwell assay was recruited to detect the invasive and migratory abilities of lung cancer cells. Furthermore, dual-luciferase reporter gene assay was designed to verify the target gene of miR-431. Western blot assay was used to gauge the protein level of DDX5 (DEAD box polypeptide 5).

RESULTS

MiR-431 expression was significantly lower in 122 lung cancer tissue samples or cell lines compared to the adjacent normal tissues or lung bronchial epithelial cell line, respectively. Over-expression of miR-431 significantly inhibited proliferation, invasion and migration of A549 cells. Down-regulation of miR-431 accelerated cell growth and metastasis of H1650 cells. DDX5 was proved to be a direct target for miR-431 in lung cancer.

CONCLUSIONS

MiR-431 expression decreased in lung cancer tissues and cells. MiR-431 suppressed proliferation, invasion and migration of lung cancer cells via inhibiting the expression of DDX5. Our study might provide a novel target for the biological therapy of lung cancer.

[Epidemic trend and control progress of soil-transmitted nematodiasis in Jiangsu Province]

Soil-transmitted nematodiasis was once widely prevalent in Jiangsu Province, which seriously threatened human health and hindered socioeconomic development. The control efforts over decades resulted in a remarkable decline in the prevalence of soil-transmitted nematode human infections in Jiangsu Province, with a reduction from 59.32% in 1989 to 0.12% in 2019, and the human prevalence remains at < 0.5% since 2013. Since 1987, an integrated strategy has been adopted for the control of soil-transmitted nematodiasis in Jiangsu Province; however, the core interventions varies at different stages, which mainly include deworming, water and sanitation service improvement, health education, and monitoring and assessment. The criteria of effective soil-transmitted nematodiasis control had been achieved in all epidemic counties (districts) of Jiangsu Province by 2019. Further actions to strengthen health education and monitoring and implement precision control measures are required to consolidate the achievements of soil-transmitted nematodiasis control and eliminate the harm of soil-transmitted nematodiasis to humans. This review summarizes the epidemiology, control progress and evolution of control strategy of soil-transmitted nematodiasis in Jiangsu Province.

[Clinical analysis of 150 cases of 2019 novel coronavirus infection in Nanyang City, Henan Province]

Objective: To analyze the epidemiological characteristics and clinical features of the patients with 2019-nCoV infection in Nanyang City, so as to provide evidence for clinical diagnosis and treatment. Methods: The epidemiology, clinical symptoms, atory and radiologic data of 150 patients with 2019-nCoV infection admitted to the designated hospitals in Nanyang City from January 24,2020 to February 16, 2020 were retrospectively analyzed. Results: The 150 patients with 2019 nCov infection consisted of 67 men and 83 women, and the median age was (45±16) years; 69 of them were the first generation case,60 of them were the second generation case, 6 of them were the third generation case,the median incubation period of the first generation case was (5.4±2.2) days, and the second generation case was (6.7±3.1) days, and the first-generation cases are the majority in severe patients (69%) . The most common basic disease was hypertension (13 cases, 9%), diabetes (9 cases, 6%), and the most common symptom is fever(142 cases, 95%, 63% showed moderate fever) , cough and sputum(108 cases,72%), fatigue(23 cases,15%), anorexia(20 cases, 13%), headache, diarrhea, muscle soreness, sore throat as the first symptoms. The average time from onset of symptoms to consultation was (4.2±2.2) days for all patients. The changes in peripheral blood cells were mainly lymphonpenia (83 cases, 55%) and eosinophilia (95 cases, 63%), The lymphocyte count of the severe and critically ill patients was more significantly reduced, and some patients had increased myocardial enzymes, mainly LDH (47 cases, 31%), and a few patients had liver function damage, mainly manifested in ALT and AST. High, very few patients have renal impairment. Among the inflammation-related indicators, the main manifestations are increased CRP (66 cases, 43%) and ESR (86 cases, 57%), elevated D-Dimer in 29% of patients. 144 cases have different degrees of infective lesions in chest CT examination, with 30 cases (21%) on one side and 144 cases (79%) on both sides. Morphologically, most of the lesions were patchy ground glass lesions, which could be accompanied by air bronchus signs and some consolidation and paving stone signs. Of the cases showing "white lung", 87% were sever ill or critically ill. After active treatment, 45% of patients were discharged according to discharge standards. 33% of sever and critically ill patients were discharged, 49% of them were degraded hospitalization.The average length of hospitalization was (12±4) days. Conclusion: A history of epidemiological exposure, fever, chest CT with signs of pneumonia, normal or decreased WBC, and lymphocytopenia, eosinophilia are the clinical basis for the diagnosis of this disease, and most of the sever patients were the first generation cases. The degree of lymphocytopenia is related to the severity of the disease.

Particulate matter air pollution and the expression of microRNAs and pro-inflammatory genes: Association and mediation among children in Jinan, China

Exposure to particulate matter (PM) has been associated with increased risk of various diseases, possibly through its effect on inflammatory response. MicroRNAs (miRNAs), an epigenetic mechanism regulating gene expression, can affect the expression of pro-inflammatory genes. However, few epidemiological studies have examined the impact of PM on inflammation-related miRNAs and their target mRNAs, especially among vulnerable population. We recruited 160 and 113 children from areas with different PM level in Jinan, China. We measured benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts in serum and the expression of 5 candidate miRNAs involved in inflammation regulation and 7 pro-inflammatory genes predicted to be their targets in leukocytes. Generally, children in the polluted area had higher miRNAs and lower mRNAs expression than those in the control area. An interquartile increase of BPDE-Alb adducts was associated with 12.66 %, 14.13 %, and 12.76 % higher of let-7a, miR-146a-5p, and miR-155-5p, as well as 21.61 %, 20.16 %, and 12.49 % lower of IL-6, CXCL8, and TLR2 mRNAs at false discovery rate<0.05, respectively. Additionally, let-7a, miR-146a-5p, and miR-155-5p were found to mediate the associations of BPDE-Alb adducts with IL-6 and/or TLR2 expression. Our findings suggested that PM exposure might attenuate inflammatory response among children in China, which was partly mediated by miRNAs regulating pro-inflammatory genes.

Development of a co-culture model of mouse primary hepatocytes and splenocytes to evaluate xenobiotic genotoxicity using the medium-throughput Comet assay

To date, only a limited number of toxicological studies have focused on the establishment and validation of in vitro genotoxicity screening systems using primary hepatocytes, and the results of these studies have been inconsistent. Therefore, the aim of this study was to develop an effective co-culture model of mouse-derived primary hepatocytes and splenocytes for screening chemicals for genotoxicity using the medium-throughput Comet assay. This cocultured model was constructed and verified using known genotoxic and non-genotoxic compounds as positive and negative controls, respectively. Cytotoxicity was measured using Cell Counting Kit-8 and lactate dehydrogenase methods. DNA damage was detected using both alkaline and formamidopyrimidine DNA glycosylase (FPG) Comet assays. Compared with the controls, DNA strand breaks and FPG-sensitive sites showed significant concentration-dependent increases in genotoxic-agent-treated groups. In contrast, DNA damage remained unchanged in non-genotoxic-agent-treated groups. In addition, different types of genotoxic agents resulted in different time-dependent DNA lesions. Our results indicated that the % tail DNA indicating both DNA strand breaks and FPG-sensitive sites might be effective markers for predicting chemical-induced DNA damage and oxidative DNA damage using the cocultured model of hepatocytes and splenocytes. Collectively, these findings provide reliable experimental data for the establishment of in vitro genotoxicity screening methods.

[Investigation on the risk of of Anisakis infection among high - risk populations along the coastal areas of Jiangsu Province]

OBJECTIVE

To investigate the risk of Anisakis infections among high-risk populations along the coastal areas of Jiangsu Province, so as to develop the strategy for the prevention and control of anisakiasis in the province.

METHODS

Three counties along the coastal areas of Jiangsu Province were selected as the study sites in 2018, including Rudong County in Nantong City, Haizhou District in Lianyungang City and Dongtai City in Yancheng City. The knowledge, attitude and practice (KAP) of anisakiasis prevention and control, and the prevalence of serum specific IgG antibody against Anisakis were investigated among high-risk populations among these three study sites, including fishermen, fish seller and people who liked eating fresh and live marine fish. Factors affecting the prevalence of the specific IgG antibody against Anisakis were identified using a multiple logistic regression model. In addition, Anisakis larvae infections were detected in fresh and live marine fish samples collected from local markets, and the prevalence and intensity of Anisakis infections were estimated.

RESULTS

A total of 625 high-risk populations were investigated, including 349 men (55.8%). Only 13.0% of the subjects heard about anisakiasis, and a low awareness rate of anisakiasis prevention and control knowledge was seen among these three types of high-risk populations. There were 21.6% of the subjects eating raw or half-cooked marine fish, 5.8% eating undercooked marine fish, 3.2% presenting vomiting, nausea and diarrhea after eating marine fish, 5.1% developing systemic allergic symptoms, and 65.6% using the same chopping board for raw and cooked food. The sero-prevalence of the anti-Anisakis IgG antibody was 7.0% among the study subjects. Multiple logistic regression analysis identified education level [OR = 0.687, 95% CI (0.478, 0.987)] and development of systemic allergic symptoms [OR = 4.641, 95% CI(1.411, 15.268)]as factors affecting the positive anti-Anisakis IgG antibody among the study subjects. Among 494 fresh and live marine fish detected, the prevalence and intensity of Anisakis larvae infection was 64.0% and 8.1 larvae per fish, with high prevalence seen in Trichiurus haumela and Pneumatophorus japonicas.

CONCLUSIONS

The awareness of anisakiasis prevention and control knowledge is low among the high-risk populations living along the coastal areas of Jiangsu Province, and there are high-risk behaviors, such as eating raw or half-cooked food, using the same chopping board for raw and cooked food. In addition, the prevalence of Anisakis infections is high in the marine fish in these areas. Therefore, the health education and health promotion for anisakiasis prevention and control should be intensified.

[A multicenter survey of the accessibility of essential medicines for children in China]

Objective: To investigate the availability, prices and affordability of essential medicines in pediatric population across China, in the hope of improving rational use of medicines. Methods: A multicenter cross-sectional survey of medicine prices, availability and affordability was conducted in 17 provinces, municipalities and autonomous region across east, south-central part, west and north of China. Data on 42 medicines used in pediatric population, both original and generic, were collected in 55 public hospitals from May 26 to June 2, 2017. Availability was expressed as the percentage of hospitals with stock of the target medicine on the day of data collection,and median price ratio (MPR) was the ratio of price upon investigation to international reference. Based on national minimum daily wage, affordability represents the number of working days needed to earn the expense which covers a standard course using the target medicine. Statistical software SPSS 13.0 was applied for descriptive analysis of availability, MPR and affordability. Results: Mean Availability of original and generic medicine was 33% and 32%, with median MPR being 5.43 and 1.55. Among the 19 medicines with price information for both original and generic product, the median MPR was 7.73 and 2.04 respectively. Regarding the five medicines used to treat four common pediatric diseases (pneumonia,peptic ulcer, congenital hypothyroidism, refractory nephrotic syndrome), the affordability was 0.63 (0.16-6.17) d for generic medicine, and 1.03 (0.16-11.53) d for its original counterpart. Conclusions: The availability to both original and generic products of the 42 medicines used in pediatric population was low in China. The prices of generic medicines seem to be lower and affordability higher than those of original medicines. There is an urgent need to improve the availability and affordability of pediatric medicines.

Transcriptomic changes in the nasal epithelium associated with diesel engine exhaust exposure

BACKGROUND

Diesel engine exhaust (DEE) exposure causes lung cancer, but the molecular mechanisms by which this occurs are not well understood.

OBJECTIVES

To assess transcriptomic alterations in nasal epithelium of DEE-exposed factory workers to better understand the cellular and molecular effects of DEE.

METHODS

Nasal epithelial brushings were obtained from 41 diesel engine factory workers exposed to relatively high levels of DEE (17.2-105.4 μg/m3), and 38 unexposed workers from factories without DEE exposure. mRNA was profiled for gene expression using Affymetrix microarrays. Linear modeling was used to identify differentially expressed genes associated with DEE exposure and interaction effects with current smoking status. Pathway enrichment among differentially expressed genes was assessed using EnrichR. Gene Set Enrichment Analysis (GSEA) was used to compare gene expression patterns between datasets.

RESULTS

225 genes had expression associated with DEE exposure after adjusting for smoking status (FDR q < 0.25) and were enriched for genes in pathways related to oxidative stress response, cell cycle pathways such as MAPK/ERK, protein modification, and transmembrane transport. Genes up-regulated in DEE-exposed individuals were enriched among the genes most up-regulated by cigarette smoking in a previously reported bronchial airway smoking dataset. We also found that the DEE signature was enriched among the genes most altered in two previous studies of the effects of acute DEE on PBMC gene expression. An exposure-response relationship was demonstrated between air levels of elemental carbon and the first principal component of the DEE signature.

CONCLUSIONS

A gene expression signature was identified for workers occupationally exposed to DEE that was altered in an exposure-dependent manner and had some overlap with the effects of smoking and the effects of acute DEE exposure. This is the first study of gene expression in nasal epithelial cells of workers heavily exposed to DEE and provides new insights into the molecular alterations that occur with DEE exposure.