DNA polymerase β may be involved in protecting human bronchial epithelial cells from the toxic effects induced by methyl tert-butyl ether exposure

Methyl tert-butyl ether (MTBE), a widely used gasoline additive and a ubiquitous environmental pollutant in many countries and regions, can cause various kinds of toxic effects on human health. However, the molecular mechanism underlying its toxic effects remains elusive. The present study aimed to explore the cytotoxicity, DNA damage and oxidative damage effects of MTBE on human bronchial epithelial cells (16HBE) and the possible role of DNA polymerase β (pol-β) in this process. RNA interference (RNAi) was used to obtain pol-β gene knocked-down cells (pol-β^-). CCK-8 assay was adopted to analyze the cell viability. Alkaline single-cell gel electrophoresis (SCGE) was performed to detect the DNA damage effects of MTBE. The enzyme activity of GSH-Px, SOD, CAT and the level of MDA were assessed. The data indicated that when treated with MTBE at the concentration exceeding 50 μmol/L and for the time exceeding 24 h, the pol-β^- exhibited significantly decreased cell viability and increased DNA damage effects, as compared to the control (P < 0.05). Furthermore, there was significant difference in the levels of GSH-pX, SOD, CAT and MDA between the pol-β^- and the control (P < 0.05). Our investigation suggests that MTBE can cause obvious cytotoxicity, DNA damage and oxidative damage effects on 16HBE cells. DNA polymerase β may be involved in protecting 16HBE cells from the toxic effects induced by MTBE exposure. These findings provide a novel insight into the molecular mechanism underlying the toxic effects of MTBE on human cells.

[Contribution of sympathetic activation to antihypertrophic memory after regression of exercise-induced physiological myocardial hypertrophy in mice]

OBJECTIVE

To investigate whether anti-hypertrophic memory exists after regression of exercise-induced physiological myocardial hypertrophy (PMH) and explore the contribution of sympathetic activation to hypertrophic memory formation.

OBJECTIVE

Seventy-two mice were randomized equally into 6 groups, including sedentary sham-operated group, exercise hypertrophic preconditioning (EHP) + sham operation group, bisoprolol (an adrenergic β1 receptor blocker) + EHP + sham operation group (biso+Exe+Sham group), sedentary group with transverse aortic constriction (TAC) (Sed+TAC group), EHP+ TAC group (Exe+TAC group), and bisoprolol+EHP+TAC group (biso+Exe+TAC group). The mice in the EHP groups were subjected to 3 weeks of swimming training, and in the bisoprolol groups, bisoprolol was administered by gavage once daily from two days before till the end of the training. One week after the training, TAC or sham surgery was performed. Echocardiography and hemodynamic measurements were performed to evaluate cardiac function of the mice, and the myocardial tissues were examined histologically to detect cardiac remodeling.

OBJECTIVE

Compared with the sedentary group, the mice receiving 3 weeks of swimming training had significantly increased heart weight to body weight ratio (HW/BW), HW to tibia length ratio (HW/TL), and the cross-sectional area of the cardiomyocytes (P < 0.05). One week after the training, exercise-induced PMH rapidly diminished and both HW/BW and HW/TL recovered the baseline levels. Treatment with bisoprolol obviously prevented the occurrence of PMH. Four weeks after TAC, the left ventricular posterior wall thickness, HW/BW, HW/TL, left ventricular end diastolic pressure and cross-sectional area of cardiomyocytes were all significantly lower (P < 0.05) while the left ejection fraction and maximal change rate of left ventricular pressure were significantly higher (P < 0.05) in Exe + TAC group than in Sed + TAC group. No significant difference was found in these parameters between biso + Exe + TAC group and Sed + TAC group.

OBJECTIVE

Anti-hypertrophic memory exists even after the regression of exercise-induced PMH, which may be attributed to the activation of sympathetic nervous system during exercise.

Nicotinamide improves NAD+ levels to protect against acetaminophen-induced acute liver injury in mice

Acetaminophen (APAP) overdose causes acute liver injury (ALI). Nicotinamide adenine dinucleotide (NAD) is an essential coenzyme, and NAD⁺ is oxidized type which synthesized from nicotinamide (NAM). The present study aimed to investigate the role of NAD⁺ in ALI and protective property of NAM. The mice were subjected to different doses APAP. After 8 hours, the serum activities of alaninetransaminase (ALT) and aspartate aminotransferase (AST), the hepatic NAD⁺ level and nicotinamide phosphoribosyltransferase (NAMPT) expression were determined. Then, the mice were pretreated with NAM (800 mg/kg), the hepatoprotective effects and the key antioxidative molecules were evaluated. Our findings indicated that APAP resulted in remarkable NAD⁺ depletion in a dose-dependent manner accompanied by NAMPT downregulation, and NAM pretreatment significantly elevated the NAD⁺ decline due to upregulation of NAMPT. Moreover, the downregulated Kelch-like ECH-associated protein-1 (Keap1), upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) and its translocation activation after NAM administration were confirmed, which were in accordance with improved superoxide dismutase (SOD) and glutathione (GSH) levels. Finally, NAM dramatically exhibited hepatoprotective effects by reducing the liver index and necrotic area. This study has suggested that APAP impairs liver NAD⁺ level and NAM is able to improve hepatic NAD⁺ to activate antioxidant pathway against APAP-induced ALI.

SARS-CoV-2 Seropositivity among Dental Staff and the Role of Aspirating Systems

INTRODUCTION

Health care workers (HCWs) are at a high risk of infection owing to occupational exposure to patients and virus-contaminated surfaces.

OBJECTIVES

The study was aimed to reveal and compare the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among patient-facing HCWs across 3 dental clinics equipped with different types of aspirating systems.

METHODS

This retrospective cohort study included 157 HCWs (43.58 ± 1.66 y) from 3 dental clinics in Ekaterinburg (Russian Federation) who reported to work during the coronavirus disease pandemic. All HCWs underwent serological testing once a week to detect immunoglobulin G and M antibodies against the SARS-CoV-2. The V6000 aspirating system with a vacuum controller (dry or semidry mode) and high-efficiency particulate air (HEPA) filters was used at clinics A and B, and the aspirated aerosol and air were evacuated and dissipated into the atmosphere. The VS900 aspirating vacuum pump without HEPA filters was used at clinic C. The aspirated aerosol and air were evacuated and dissipated into the operatories. All dental clinics followed the same recommendations for dental patient management and types of personal protective equipment used.

RESULTS

The estimated prevalence of SARS-CoV-2 infection was 11.5% (19 HCWs) over a 5-mo follow-up (May to August 2020). The prevalence of infection was unaffected by sex or the role of the member in the dental team (dentist/dental assistant). The prevalence of SARS-CoV-2 infection (+) was significantly higher at clinic C (equipped with an aspirating vacuum pump without HEPA filters) than at other clinics.

CONCLUSION

The type of aspirating system used and the presence of HEPA filters could affect the prevalence of SARS-CoV-2 infection across dental clinics. Therefore, we recommend the use of aspirating systems installed with HEPA filters, which evacuate and dissipate aerosols into specialized areas.

KNOWLEDGE TRANSFER STATEMENT

This report confirms that dentists, being patient-facing HCWs, are at a high risk of acquiring the SARS-CoV-2 infection and identifies gaps in the protection of patients and staff in dental settings.

Spatiotemporal variations and reduction of air pollutants during the COVID-19 pandemic in a megacity of Yangtze River Delta in China

In recent decades, air pollution has become an important environmental problem in the megacities of eastern China. How to control air pollution in megacities is still a challenging issue because of the complex pollutant sources, atmospheric chemistry, and meteorology. There is substantial uncertainty in accurately identifying the contributions of transport and local emissions to the air quality in megacities. The COVID-19 outbreak has prompted a nationwide public lockdown period and provides a valuable opportunity for understanding the sources and factors of air pollutants. The three-month period of continuous field observations for aerosol particles and gaseous pollutants, which extended from January 2020 to March 2020, covered urban, urban-industry, and suburban areas in the typical megacity of Hangzhou in the Yangtze River Delta in eastern China. In general, the concentrations of PM_2.5-10, PM_2.5, NO_x, SO₂, and CO reduced 58%, 47%, 83%, 11% and 30%, respectively, in the megacity during the COVID-Lock period. The reduction proportions of PM_2.5 and CO were generally higher in urban and urban-industry areas than those in suburban areas. NO_x exhibited the greatest reduction (>80%) among all the air pollutants, and the reduction was similar in the urban, urban-industry, and suburban areas. O₃ increased 102%-125% during the COVID-Lock period. The daytime elevation of the planetary boundary layer height can reduce 30% of the PM₁₀, PM_2.5, NO_x and CO concentrations on the ground in Hangzhou. During the long-range transport events, air pollutants on the regional scale likely contribute 40%-90% of the fine particles in the Hangzhou urban area. The findings highlight the future control and model forecasting of air pollutants in Hangzhou and similar megacities in eastern China.

Depression and one-year survival of patients with heart failure in China: analysis from the China-PEACE Prospective Heart Failure study

Background

Depression is prevalent among patients with heart failure (HF), but data exploring association of depression with risk of death in patients with HF is scarce in China. We investigated the relationship between depression and all-cause mortality of heart failure in China.

Methods

In China PEACE 5p-HF Study, we prospectively enrolled patients primarily hospitalized with HF from 52 diverse hospitals throughout China during 2016–2018. All the patients were followed up for 1 year. About 10% patients in the cohort from 41 hospitals was included for the measurement of depression state at convenience. Depression was measured by the Patient Health Questionnaire-8 depression scale (PHQ-8) at baseline. Depression state was categorized into major depressive disorder (10–24 points), minor depression (5–10 points) and no depression (0–5 points). Cox proportional hazards regression analyses, controlling for established risk factors as age, gender, LVEF, NYHA, medication use and medical history, were used to evaluate how depression were related to end point of death from any cause.

Results

Total 584 patients were included in our analysis, with median age 69 (IQR 60–77) years, and 40.8% female. Among these patients, 36.0% had major depressive disorder (n=210), 33.9% had minor depression (n=198). There were 70 (12%) patients died within 1 year after discharge. Major depressive disorder was associated with higher all-cause mortality compared with no depression (hazard ratio=2.18, 95% confidence interval 1.36–3.50, p=0.001). While minor depression was not significantly associated with all-cause mortality.

Conclusions

Major depression is an independent risk factor for all-cause mortality in hospitalized patients with HF in China. It is necessary to screen for psychological health in hospitalized patients to targeting intervention.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): National Key Research and Development Program from the Ministry of Science and Technology of China

An epistatic interaction between pre-natal smoke exposure and socioeconomic status has a significant impact on bronchodilator drug response in African American youth with asthma

BACKGROUND

Asthma is one of the leading chronic illnesses among children in the United States. Asthma prevalence is higher among African Americans (11.2%) compared to European Americans (7.7%). Bronchodilator medications are part of the first-line therapy, and the rescue medication, for acute asthma symptoms. Bronchodilator drug response (BDR) varies substantially among different racial/ethnic groups. Asthma prevalence in African Americans is only 3.5% higher than that of European Americans, however, asthma mortality among African Americans is four times that of European Americans; variation in BDR may play an important role in explaining this health disparity. To improve our understanding of disparate health outcomes in complex phenotypes such as BDR, it is important to consider interactions between environmental and biological variables.

RESULTS

We evaluated the impact of pairwise and three-variable interactions between environmental, social, and biological variables on BDR in 233 African American youth with asthma using Visualization of Statistical Epistasis Networks (ViSEN). ViSEN is a non-parametric entropy-based approach able to quantify interaction effects using an information-theory metric known as Information Gain (IG). We performed analyses in the full dataset and in sex-stratified subsets. Our analyses identified several interaction models significantly, and suggestively, associated with BDR. The strongest interaction significantly associated with BDR was a pairwise interaction between pre-natal smoke exposure and socioeconomic status (full dataset IG: 2.78%, p = 0.001; female IG: 7.27%, p = 0.004)). Sex-stratified analyses yielded divergent results for females and males, indicating the presence of sex-specific effects.

CONCLUSIONS

Our study identified novel interaction effects significantly, and suggestively, associated with BDR in African American children with asthma. Notably, we found that all of the interactions identified by ViSEN were "pure" interaction effects, in that they were not the result of strong main effects on BDR, highlighting the complexity of the network of biological and environmental factors impacting this phenotype. Several associations uncovered by ViSEN would not have been detected using regression-based methods, thus emphasizing the importance of employing statistical methods optimized to detect both additive and non-additive interaction effects when studying complex phenotypes such as BDR. The information gained in this study increases our understanding and appreciation of the complex nature of the interactions between environmental and health-related factors that influence BDR and will be invaluable to biomedical researchers designing future studies.

Abstract PR05: A genetic variant at 6q25 associated with estrogen receptor-negative breast cancer subtypes in Peruvian breast cancer patients

Background: We have previously identified a genetic variant, rs140068132, which has a strong protective effect on breast cancer risk. This variant is located near the estrogen receptor 1 gene (ESR1) on chromosome 6q25, a locus which has been repeatedly implicated in breast cancer risk. Women who carry two copies of the protective variant (GG) have 60-70% reduction in risk of developing breast cancer compared to women with none. The G variant has relatively high frequency in Latin American women (up to 23% in the 1000 Genomes Project Peruvians); it is only common in people of Indigenous American ancestry and almost absent in all other populations. We investigated whether the rs140068132-A/G polymorphism is associated with a specific breast cancer subtype among Peruvian women with breast cancer.

Methods: Blood samples and clinical data were collected from 441 women with breast cancer at the Instituto Nacional de Enfermedades Neoplasicas in Lima, Peru. Genotypic profiles were generated using the Affymetrix Precision Medicine Research Array. Four major breast cancer subtypes were identified based on immunohistochemical markers (luminal A, luminal B, triple-negative, and human epidermal growth factor receptor 2 (HER2) overexpressing). Quality control of the genotyped data was performed in PLINK. Genetic ancestry was determined for each individual using ADMIXTURE. ANOVAs were performed on the proportion of genetic ancestry and disease subtype. PLINK was used to perform a binary logistic regression on the rs140068132 variant and ER status (ER-negative versus-ER positive), with age and genetic ancestry as covariates.

Results: The breast cancer patients analyzed have the following average ancestry proportions: 77.3% Indigenous American, 17.4% European, 3.8% African and 1.5% East Asian. The frequency of the G allele in the Peruvian breast cancer patients is 14% (compared to 23% in healthy individuals from the 1000 Genomes Project). We found that the G allele of rs140068132 was associated with ER-negative status among cases (OR = 0.6443, P = 0.086) for both HER2 overexpressing and triple-negative. We also examined the proportions of ancestry in relation to subtypes of disease. The proportion of Indigenous American ancestry was associated with the HER2 overexpressing subtype (P = 0.06), with an average Indigenous American ancestry among these patients of 83.1% compared to 77.3% among all patients. The proportion of African ancestry was higher in women with the triple-negative subtype, with an average African ancestry of 4.8% among patients with the triple-negative subtype compared to a 3.8% average among all patients, but this trend was not statistically significant (P = 0.21).

Conclusions: The lower frequency of the variant in Peruvian breast cancer cases is consistent with a protective effect in this population. We have confirmed that the protective effect of the rs140068132 variant is stronger for ER-negative subtypes. Additional analyses are under way in a larger sample of Peruvian breast cancer patients.

This abstract is also being presented as Poster C051.

Citation Format: K.M. Marker, T. Vidaurre, L.I. Tamayo, J.N. Vásquez, R. Meza Florez, S. Casavilca, M. Calderon, J.E. Abugattas, H.L. Gómez, H.A. Fuentes, C.L. Monge Pimentel, S. Song, D. Cherry, S. Huntsman, D. Hu, E. Ziv, L. Fejerman. A genetic variant at 6q25 associated with estrogen receptor-negative breast cancer subtypes in Peruvian breast cancer patients [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr PR05.

[Study on the relationship between urinary polycyclic aromatic hydrocarbons metabolites and pulmonary function in community population]

Objective: To investigate the relationship between urinary polycyclic aromatic hydrocarbons(PAHs) metabolites and pulmonary function in community population. Methods: A total of 4 812 participants were recruited from two communities in Wuhan city from April to May 2011 and two communities in Zhuhai city in May 2012. Information of demographic characteristics and life style was collected by semi-structural questionnaire. Physical examination was performed and pulmonary function was measured. Morning urine was also collected. The concentration of 12 urinary PAHs metabolites was tested and classified into four types by chemical structure, including hydroxynaphthalene, hydroxyfluorene, hydroxyphenanthrene and hydroxypyrene. The level of pulmonary function in different group of urinary PAHs metabolites was compared by using covariance analysis. The association of the urinary PAHs metabolites and pulmonary function was analyzed by using generalized linear model, and the interaction of different population characteristics and life style on the association was analyzed. Results: The age of participants was(51.99±13.64) years old, and 67.66% (n=2 565) of the population were women. The M (P(25), P(75)) of concentration of total urinary PAHs metabolites was 5.72 (3.91,8.72) μg/mmol Cr. After controlling for variables including age, gender, city, Waist-to-Hip Ratio, smoking status, drinking situation, physical activity, cooking meals at home or not, kitchen ventilation and exposure to dust as confounding factors, generalized linear model showed that each 1-unit increase in log-transformed levels of hydroxynaphthalene, hydroxyfluorene, hydroxyphenanthrene, hydroxypyrene and total PAHs was associated with 26.83 (95%CI: -48.18, -5.48) , 21.86 (95%CI: -40.49, -3.23), 26.18(95%CI: -48.27, -4.09), 34.95 (95%CI: -55.95, -13.94), and 35.23 (95%CI: -58.93, -11.54) ml reduction of FVC and 29.36 (95%CI: -47.23, -11.48), 20.79 (95%CI: -36.39, -5.19), 22.65 (95%CI: -41.15, -4.15), 31.44(95%CI: -49.03, -13.85), and 33.20 (95%CI: -53.04, -13.36) ml reduction of FEV(1) respectively (all P values<0.05). Compared to non-alcohol users and participants with home cooking, the association was more evident in alcohol users and participants without home cooking(P for interaction<0.05). Conclusion: The exposure to PAHs was associated with decreased pulmonary function, and the association was more evident in alcohol users and participants without home cooking.

Seasonal variation of atmospheric vertical extinction and its interaction with meteorological factors in the Yangtze River Delta region

Based on ground-based lidar and microwave radiometer observations in Hangzhou from 1 January 2013 to 31 December 2015, the monthly characteristics of diurnal extinction as well as atmospheric boundary layer (ABL) were studied. The interactions between temperature (T), humidity fields including relative humidity (RH) and specific humidity (SH) and atmospheric stratification (AS) were analyzed to discuss the meteorological factors in the Yangtze River Delta region during the study period. The top of ABL_MPL varied from 0.8 km to 1.0 km throughout in January with higher extinction intensity close to the surface combined to the largest PM_2.5 about 100-120 μg/m³. Then the ABL_MPL could develop up to 1.5 km in the spring due to the weaker extinction during the daytime. The RH in the whole column in January and December was lower than the mean value (ranging from 5% to 20%) distributed from the ground to 3 km. From May to September, the RH anomaly profiles became positive contributed to larger extinction by strengthened the particle scattering ability. In January and December, the AS was stable from the surface to 3 km coincided with the extinction distribution; while in July and August, the gradient of Δθ_se decreased which favored the diffusion of particle in the air. Moreover, April and October presented turning points in the variation of θ_se. The humidity field reveals a stable condition in January and December which favored particles suppressed from the near surface to 3 km; the temperature field has tended towards a neutral state in most months except for February. The first change-point of the meteorological fields was found in April possibly attributable to the abnormal abrupt in the subtropical high. This study could have important reference for understanding regional air quality and governing air control.

Chestnut extract but not sodium salicylate decreases the severity of diarrhea and enterotoxigenic Escherichia coli F4 shedding in artificially infected piglets

The development of alternatives to antibiotics is crucial to limiting the incidence of antimicrobial resistance, especially in prophylactic and metaphylactic use to control post-weaning diarrhea (PWD). Feed additives, including bioactive compounds, could be a promising alternative. This study aimed to test two bioactive compounds, sodium salicylate (SA) and a chestnut extract (CE) containing hydrolysable tannins, on the occurrence of PWD. At weaning, 72 piglets were assigned to four treatments that combined two factors: CE supplementation (with 2% of CE (CE+) or without (CE-)) and SA supplementation (with 35 mg/kg BW of SA (SA+) or without (SA-)). Then, 4 days after weaning, all piglets were infected with a suspension at 10⁸ CFU/ml of enterotoxigenic Escherichia coli (ETEC F4ac). Each piglet had free access to an electrolyte solution containing, or not, SA. This SA supplementation was administered for 5 days (i.e., from the day of infection (day 0) to 4 days post-infection (day 4). During the 2 weeks post-infection, supplementation with SA had no effect (P > 0.05) on growth performances nor on fecal scores. A significant SA × time interaction (P < 0.01) for fecal scores and the percentage of diarrhea indicated that piglets with SA did not recover faster and did have a second episode of diarrhea. In contrast to SA treatment, inclusion of CE increased (P < 0.05) growth performances and feed intake. In the first week post-infection, CE decreased (P < 0.001) the overall fecal scores, the percentage of piglets with diarrhea, the days in diarrhea, and ETEC shedding in the feces. There was a SA×CE interaction (P < 0.05) for ETEC shedding, suggesting a negative effect of combining SA with CE. This study highlighted that, in contrast to SA, CE could represent a promising alternative to antibiotics immediately after weaning for improving growth performance and reducing PWD.

Genomic origin and EGFR-TKI treatments of pulmonary adenosquamous carcinoma

BACKGROUND

Adenosquamous carcinoma (ASC) of the lung is a heterogeneous disease that is composed of both adenocarcinoma components (ACC) and squamous cell carcinoma components (SCCC). Their genomic profile, genetic origin, and clinical management remain controversial.

PATIENTS AND METHODS

Resected ASC and metastatic tumor in regional lymph nodes (LNs) were collected. The ACC and SCCC were separated by microdissection of primary tumor. The 1021 cancer-related genes were evaluated by next-generation sequencing independently in ACC and SCCC and LNs. Shared and private alterations in the two components were investigated. In addition, genomic profiles of independent cohorts of adenocarcinomas and squamous cell carcinomas were examined for comparison. We have also carried out a retrospective study of ASCs with known EGFR mutation status from 11 hospitals in China for their clinical outcomes.

RESULTS

The most frequent alterations in 28 surgically resected ASCs include EGFR (79%), TP53 (68%), MAP3K1 (14%) mutations, EGFR amplifications (32%), and MDM2 amplifications (18%). Twenty-seven patients (96%) had shared variations between ACC and SCCC, and pure SCCC metastases were not found in metastatic LNs among these patients. Only one patient with geographically separated ACC and SCCC had no shared mutations. Inter-component heterogeneity was a common genetic event of ACC and SCCC. The genomic profile of ASC was similar to that of 170 adenocarcinomas, but different from that of 62 squamous cell carcinomas. The incidence of EGFR mutations in the retrospective analysis of 517 ASCs was 51.8%. Among the 129 EGFR-positive patients who received EGFR-TKIs, the objective response rate was 56.6% and the median progression-free survival was 10.1 months (95% confidence interval: 9.0-11.2).

CONCLUSIONS

The ACC and SCCC share a monoclonal origin, a majority with genetically inter-component heterogeneity. ASC may represent a subtype of adenocarcinoma with EGFR mutation being the most common genomic anomaly and sharing similar efficacy to EGFR TKI.

Low expression of lncRNA MEG3 promotes the progression of oral squamous cell carcinoma by targeting miR-21

OBJECTIVE

The aim of this study was to explore whether maternally expressed gene 3 (MEG3) could facilitate the proliferation and migration of oral squamous cell carcinoma (OSCC) cells by selectively binding to miR-21, thereby participating in the progression of OSCC.

PATIENTS AND METHODS

The expression levels of MEG3 and miR-21 in OSCC tissues and normal control tissues were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The effects of MEG3 and miR-21 on cell proliferation and migration were examined by cell counting kit-8 (CCK-8), transwell, and scratch assay, respectively. Meanwhile, cell cycle was detected using flow cytometry. The binding relationship between miR-21 and MEG3 was confirmed by dual luciferase assay. In addition, MEG3 and miR-21 were simultaneously knock-down to figure out whether MEG3 could regulate the proliferation and migration of OSCC cells through targeted binding to miR-21.

RESULTS

QRT-PCR results indicated that MEG3 expression in OSCC tissues was remarkably lower than that of normal control tissues. However, the expression of miR-21 was significantly higher in OSCC tissues. Meanwhile, it was found that inhibiting MEG3 expression in OSCC cell lines could significantly promote cell proliferation and migration, while the simultaneous inhibition of miR-21 showed the opposite effect. Dual Luciferase assay results revealed that MEG3 could selectively bind to miR-21. In addition, we demonstrated that the knockdown of MEG3 in Tca-8113 and CAL-27 cells partially reversed the inhibitory effect of downregulated-miR-21 on cell proliferation and migration. These results further suggested that MEG3 might regulate OSCC cell proliferation via selectively binding to miR-21.

CONCLUSIONS

Low expression of MEG3 can promote the proliferation and migration of OSCC cells through targeted binding to miR-21.

Phosphorylation of nucleopolyhedrovirus 39K is essential for the regulation of viral gene transcription in silkworm cells

39K protein was proven to be the most notable hyperphosphorylated protein of Bombyx mori nucleopolyhedrovirus (BmNPV), since its amino acid 136 has the highest phosphorylation ratio (16.683) among all of BmNPV phosphorylated proteins (Shobahah et al., 2017). Therefore, we inserted positive (mimicking phosphorylation) and negative (mimicking dephosphorylation) mutants of the highest phosphorylated site of 39K and the wild type 39k into the 39k-ko-Bacmid using the Bac-to-Bac system. These three kinds of recombinant Bacmids along with wild type and knocked-out Bacmid were then transfected into the Bombyx mori cells (BmN) and further investigated by qPCR analysis. The results of the qPCR showed that 39K phosphorylation had no significant effect on viral genome replication, unlike the positive mutation that reduced the viral gene transcription drastically compared to the wild type. Thus, phosphorylation of BmNPV 39K protein does not appear to be the essential mechanism for viral genome replication, even though it has an important role in the viral gene transcription. Keywords: BmNPV; 39K; phosphorylation; virus replication; virus transcription.

Application of 18S rDNA Clone Library to Detect Diatom Population Diversity in Dianchi

Abstract

Objective To detect the diatom population diversity in Dianchi by constructing a 18S rDNA clone library. Methods DNA from diatoms in 6 water samples of Dianchi was amplified with diatom 18S rDNA specific primer.The 18S rDNA clone library was constructed, and clones were randomly selected for sequence. Sequence alignment was performed by BLAST. The diatom population distribution in Dianchi was analyzed and the phylogenetic tree of diatom 18S rDNA in Dianchi waters was established with the MEGA v7.0.14 software. Results Two hundred and forty clones were sequenced, with 167 diatom sequences obtained, including 11 diatom species such as Stephanodiscus, Diatoma, and Melosira. There were certain differences in diatom population distribution among the 6 samples. Conclusion The population distribution of diatom species in Dianchi shows unique features and the sequence analysis of diatom 18S rDNA has a certain reference value to the inference of forensic drowning sites.

[HIV prevalence and correlated factors on male clients of female sex workers in Hekou Yao autonomous county of Yunnan province, 2014-2015]

Objective: To assess the prevalence and related factors of HIV infection among male clients of the female sex workers in Hekou Yao autonomous county of Honghe Hani Yi autonomous prefecture (Hekou county) in Yunnan province in China, 2014-2015. Methods: Serial cross-sectional survey was conducted during June 2014 to November 2015. Convenience sampling methods were used to recruit the male clients for this study. Self-reported information on social-demographic characteristics, with sexual and drug behavior patterns, was gathered. Both blood and urine samples were collected for HIV, with for opiate testing. Multivariate logistic regression and Exhaustive CHAID method were used to determine the correlated factors associated with HIV infection. Statistical analysis was used by SPSS 22.0 software and Clementine 12.0 software. Results: The overall HIV prevalence of male clients was 2.06% (16/776). Male clients who keep using condom with female sex worker was estimated as 68.81% (534/776). The last commercial sexual partner of Vietnamese male clients was all Vietnamese female sex workers. Compared with Chinese male clients, Vietnamese male clients have a higher rate of morphine positive. Factors as: age ≥50 years vs. age <30 years (OR=8.11, 95%CI: 1.26-52.16) and testing for morphine positive vs. morphine negative (OR=7.35, 95%CI: 1.42-38.06) were significantly associated with HIV infection through multiple logistic regression analysis. Through Exhaustive CHAID, it confirmed that age was the primary factor that associated with HIV infection of male clients. Conclusions: Relationship between morphine and HIV infection indicated that HIV prevalence of male clients in Hekou county was influenced by the combined effect of both illegal drug use and commercial sexual behavior. Special attention should be paid to male clients over 50 years of age, on HIV intervention.

6-year change in resting heart rate is associated with incident type 2 diabetes mellitus

BACKGROUND AND AIMS

Elevated resting heart rate (RHR) is associated with risk of type 2 diabetes mellitus (T2DM). However, the association of change in RHR (ΔRHR) and incident T2DM is not fully elucidated. We aimed to assess the dose-response association between 6-year ΔRHR and T2DM.

METHODS AND RESULTS

A total of 12155 non-T2DM participants ≥18 years old were enrolled during 2007-2008 and followed up during 2013-2014. ΔRHR was calculated by subtracting the baseline RHR from the RHR value at 6-year follow-up. Age-, sex-, and RHR-specific relative risks (RRs) and 95% confidence intervals (CIs) for the effect of ΔRHR on incident T2DM were calculated by using modified Poisson regression models. As compared with ΔRHR of 0 beats/min, the adjusted risk of T2DM was significantly increased with RHR increment and reduced with RHR reduction. ΔRHR was positively associated with future risk of T2DM [RR per unit increase: 1.03 (1.03-1.04)]. As compared with stable change in RHR group (-5<ΔRHR<5 beats/min), for ΔRHR ≤ -10 beats/min, -10<ΔRHR ≤ -5 beats/min, 5≤ΔRHR<10 beats/min, and ΔRHR ≥10 beats/min groups, the pooled adjusted RR (95% CI) of T2DM was 0.69 (0.55-0.86), 0.90 (0.73-1.11), 1.31 (1.07-1.61), and 1.90 (1.59-2.26), respectively. This significant association still existed on subgroup analyses based on age, sex, and baseline RHR and sensitivity analyses.

CONCLUSIONS

Dynamic RHR change was significantly associated with incident T2DM. Our study suggests that RHR may be a non-invasive clinical indicator for interventions aiming to reduce incident T2DM in the general population.

Caffeinated and decaffeinated coffee consumption and risk of all-cause mortality: a dose-response meta-analysis of cohort studies

BACKGROUND

Previous meta-analysis showed an inverse association between coffee consumption and all-cause mortality. However, the relationship between caffeinated and decaffeinated coffee consumption and all-cause mortality is inconsistent. We aimed to identify and review the published evidence updating the association between coffee consumption and all-cause mortality and, furthermore, to investigate the association of caffeinated and decaffeinated coffee consumption and all-cause mortality.

METHODS

We systematically searched PubMed and Web of Science for studies published up to 9 November 2017. Cohort studies in which authors reported relative risks (RRs) of all-cause mortality for at least three levels of coffee consumption were eligible. Random-effects models were used to estimate the pooled RR of all-cause mortality with coffee consumption. Restricted cubic splines were used to model the dose-response association.

RESULTS

We included 21 cohort study articles (10 103 115 study participants and 240 303 deaths). We found a nonlinear association between coffee consumption and all-cause mortality (P_nonlinearity  < 0.001). Compared with no or rare coffee consumption, with a consumption of 3 cups day^-1 , the risk of all-cause mortality might reduce 13% (RR = 0.87; 95% confidence interval = 0.84-0.89).

CONCLUSIONS

The findings of the present study provide quantitative data suggesting that coffee consumption plays a role in reducing the risk of all-cause mortality. Similar inverse associations are found for caffeinated coffee and decaffeinated coffee.