Short-Term PM2.5 Exposure and DNA Methylation Changes of Circadian Rhythm Genes: Evidence from Two Experimental Studies.

The circadian rhythm regulates many crucial physiological processes, impacting human aging and aging-related outcomes. Observational evidence links circadian rhythm disturbance to PM2.5 exposure, yet the underlying DNA methylation mechanisms remain unclear due to limited PM2.5-dominated experimental settings. Therefore, we investigated the associations between short-term PM2.5 exposure and DNA methylation changes of 1188 CpG candidates across circadian genes among 32 young adults in the FDU study, with the validation in 26 individuals from the PKU study. Further mediation analyses tested whether DNA methylation of circadian genes could mediate the influence of PM2.5 on aging measured by three epigenetic ages: DNAmGrimAge, DunedinPoAm, and the mortality risk score. We identified three CpG sites associated with personal PM2.5 exposure: cg01248361 (CSNK2A2), cg17728065 (RORA), and cg22513396 (PRKAG2). Acute effects of PM2.5 on the three loci could be mediated by several circulating biomarkers, including MDA and EGF, with up to ∼30% of mediated proportions. Three loci further showed varying potentials in mediating the aging acceleration effect of PM2.5. Locus cg17728065 is the key site exhibiting a robust mediating effect (7.54-12.52%) on PM2.5-induced aging acceleration. Our findings demonstrated that PM2.5, even short-term peaks, could leave imprints on human aging via inducing aberrant temporal fluctuation in circadian homeostasis captured by DNA methylation profiles.

Long-term fine particular exposure and incidence of frailty in older adults: findings from the Chinese Longitudinal Healthy Longevity Survey.

BACKGROUND: The association between fine particular matter (PM2.5) and frailty is less studied, and the national burden of PM2.5-related frailty in China is unknown. OBJECTIVE: To explore the association between PM2.5 exposure and incident frailty in older adults, and estimate the corresponding disease burden. DESIGN: Chinese Longitudinal Healthy Longevity Survey from 1998 to 2014. SETTING: Twenty-three provinces in China. SUBJECTS: A total of 25,047 participants aged ≥65-year-old. METHODS: Cox proportional hazards models were performed to evaluate the association between PM2.5 and frailty in older adults. A method adapted from the Global Burden of Disease Study was used to calculate the PM2.5-related frailty disease burden. RESULTS: A total of 5,733 incidents of frailty were observed during 107,814.8 person-years follow-up. A 10 µg/m3 increment of PM2.5 was associated with a 5.0% increase in the risk of frailty (Hazard Ratio = 1.05, 95% confidence interval = [1.03-1.07]). Monotonic, but non-linear exposure-response, relationships of PM2.5 with risk of frailty were observed, and slopes were steeper at concentrations >50 µg/m³. Considering the interaction between population ageing and mitigation of PM2.5, the PM2.5-related frailty cases were almost unchanged in 2010, 2020 and 2030, with estimations of 664,097, 730,858 and 665,169, respectively. CONCLUSIONS: This nation-wide prospective cohort study showed a positive association between long-term PM2.5 exposure and frailty incidence. The estimated disease burden indicated that implementing clean air actions may prevent frailty and substantially offset the burden of population ageing worldwide.

Mortality and morbidity risk prediction for older former smokers based on a score of smoking history: evidence from UK Biobank and ESTHER cohorts.

BACKGROUND: Rapid population ageing has raised the proportion of older former smokers considerably, but a comprehensive assessment tool of former smoking-related health risks is absent. OBJECTIVE: We utilised the large-scale data of UK Biobank and ESTHER study to build a former smoking score (FSS) for older former smokers using three major former smoking traits: pack-years, smoking duration and time since smoking cessation. DESIGN: UK Biobank and ESTHER study are two cohorts of older adults with 502,528 and 9,940 participants from the UK and Germany, respectively. METHODS: Smoking history and covariates were retrieved from the self-administrated questionnaires and mortality and morbidity data were obtained through regular linkages to hospital records. RESULTS: We constructed the FSS based on the 94,446 former smokers of UK Biobank by retrieving the averaged effect estimates of each trait with a 100-time random sampling. This score was robustly associated with higher risks of mortality and incidence of major smoking-related diseases, outperforming each trait. In the validation panel of 2,683 former smokers from ESTHER study, the FSS was highly predictive of mortality and morbidities. Particularly, compared with the 1st quartile of the FSS group, the 4th quartile group had 114.1, 104.5 and 158.9% higher risks of all-cause, CVD and cancer mortality, respectively, and 41.9, 31.9, 52.4 and 831.3% higher risks of incident CVD, type 2 diabetes, any cancers and lung cancer, respectively. CONCLUSIONS: Our study demonstrates the large potential of refined risk assessment of former smokers by more comprehensive consideration of the major traits of former smoking.

Association of DNA methylation in circulating CD4+T cells with short-term PM2.5 pollution waves: A quasi-experimental study of healthy young adults.

BACKGROUND: Fine particulate matter (PM2.5) is a modifiable environmental risk factor with established adverse effects on human health. However, associations between acute PM2.5 fluctuation and DNA methylation remain unknown. METHODS: A quasi-experimental study utilizing naturally occurring PM2.5 pollution waves (PPWs) was conducted on 32 healthy young adults. Repeated follow-up measurements were performed and participants served as their own controls before, during, and after PPWs. Exposure measurements including indoor and ambient PM2.5 levels, and equivalent personal PM2.5 exposure were further estimated based on the time-location information. DNA methylation profiles of circulating CD4+T cells were obtained using Illumina HumanMethylationEPIC BeadChip. Linear mixed-effect models were applied to estimate the associations between two scenarios (during-PPWs vs. pre-PPWs periods and during-PPWs vs. post-PPWs periods) and methylation level of each CpG site. We further validated their associations with the personal PM2.5 exposure, and GO and KEGG analyses and mediation analysis were conducted accordingly. RESULTS: Data from 26 participants were included in final analysis after quality control. Short-term high PM2.5 exposure was associated with DNA methylation changes of participants. Nine differently methylated CpG sites were not only significantly associated with PPWs periods but also with personal PM2.5 exposure in 24-h prior to the health examinations (p < 0.01). Gene ontology analysis found that five sites were associated with two pathways relating to membrane protein synthesis. PM2.5-related changes in CpG sites were mediated by sP-selectin, 8-isoPGF2α, EGF, GRO, IL-15, and IFN-α2, with mediated proportions ranging from 9.65% to 23.40%. CONCLUSIONS: This is the first quasi-experimental study showing that short-term high PM2.5 exposure could alter the DNA methylation of CD4+T cells, which provided valuable information for further exploring underlying biological mechanisms and epigenetic biomarkers for PM2.5-related acute health effects.

Carbapenem-resistant Acinetobacter baumannii from Air and Patients of Intensive Care Units.

To understand the molecular epidemiology and antibiotic resistance of air and clinical isolates of Acinetobacter baumannii , the intensive care unit settings of a hospital in Northern China were surveyed in 2014. Twenty non-duplicate A. baumannii isolates were obtained from patients and five isolates of airborne A. baumannii were obtained from the wards' corridors. Pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to analyze the homology relationships of isolates. Resistance and resistance genes were detected by drug susceptibility test and PCR. The results demonstrated that all isolates can be classified into eight PFGE types and four sequence types (ST208, ST195, ST369 and ST530). A pair of isolates from patients (TAaba004) and from the air (TAaba012) that share 100% similarity in PFGE was identified, indicating that air might be a potential and important transmission route for A. baumannii . More than 80% of the isolates were resistant to carbapenems and aminoglycoside antibiotics. Twenty-four isolates, which were resistant to carbapenems, carried the bla OXA-23-like gene. The data indicated that air might be an alternative way for the transmission of A. baumannii . Hospitals should pay more attention to this route, and design new measures accordingly.

[Diversity of agronomic traits of Paris polyphylla var. chinensis and their correlation with rhizome yield and active compositions].

The supply deficiency of crude medicinal plant of Paris polyphylla var. chinensis has become a bottleneck for related medicinal industry. An important approach to increase herbal production is to breed high-yield cultivated variety, which characterized ideal plant morphology. In the present study, we collected 99 wild germplasm resources of P. polyphylla and then measured their 12 main agronomic traits and contents of polyphyllin Ⅶ,Ⅵ,Ⅱ,Ⅰ. Followed analyses were used to characterize those traits and explore the potential connection with herbal yield or quality. The results showed that: ①There was ample morphological diversity in wild P. polyphylla, whose variation of agronomic traits reduced according to followed order: content of polyphyllin, weight of dry rhizome, petiole length, stem length, petal length, pedicel length, sepal length, leaf width, leaf length, sepal width, leaf number, stamen number, petal number. ② Most of those traits were significantly correlated to each other and generally represented the characterization of photosynthetic organs or reproductive organ. ③The total content of polyphyllin Ⅶ,Ⅵ,Ⅱ,Ⅰvaried between 0.02% and 0.87% and averagedat 0.13%, which showed no significant correlation with any agronomic trait. ④Plant breeders should play more attention on those germplasm resources with large leaves, large sepals and high stem.

[Cloning, subcellular lacalization and expression analysis of chloroplast-targeted Obg gene in Cyathula officinalis].

According to ObgC gene sequences from Cyathula officinalis genomic data, the specific primers were designed, and a full-length CoObgC cDNA (2 226 bp) was obtained by polymerase chain reaction (PCR) and rapid amplification of cDNA ends (RACE) methord. Sequence alignment showed that CoObgC gene contained a 1 818 bp open reading frame (ORF) encoding 605 amino acids. Sequence analysis predicted that molecular weight of CoObgC protein was about 66.39 kDa, the academic isoelectric point was 5.35, and the protein was stable protein. Then multiple sequence alignment was applied to construct phylogenetic tree. The real-time fluorescence quantification PCR (RT-qPCR) demonstrated that a high expression level in leaf, followed by root and flower, the low transcription was in stem. The recombinant vector pCABIA2300-CoObgC was constructed and introduced into tobacco epidermal cells by agrobacterium-mediated transformation, green fluorescence was tested and targeted to chloroplast under a laser scanning confocal microscope. These findings will be helpful to lay a foundation for studying the structure and function of CoObgC gene, and elucidating C. officinalis molecular biology experiment.

Epidemiological characteristics and drug resistance analysis of multidrug-resistant Acinetobacter baumannii in a China hospital at a certain time.

Multidrug-resistant Acinetobacter baumannii is an important bacterium causing nosocomial infections; A. baumannii infections have increased in our hospital since 2009. However, multidrug-resistant A. baumannii, which was mainly isolated from patients in each intensive care unit (ICU), rapidly increased from December 2012 to January 2013. Therefore, we described the molecular characteristics of A. baumannii by pulsed-field gel electrophoresis (PFGE). We also detected resistance genes for ß-lactam, aminoglycosides, and plasmid-mediated quinolones. Disinfectant-resistant genes were also detected in the clinical isolates of blaOXA-51-positive multidrug-resistant A. baumannii. The conjugative test was performed to detect whether or not resistance genes can be transferred to different strains. Carbonyl cyanide m-chlorophenylhydrazone (CCCP) inhibition test was conducted to analyze the factors influencing the resistance of A. baumannii to imipenem, meropenem, ceftazidime, levofloxacin, and tigecycline. PFGE profiles contained 12 strains, including 20 type C strains (47.6%), 4 type D strains (9.5%), and 1 to 3 strains of other types; 38 strains were distributed in patients in each ICU. In our test samples, the presence of blaOXA-23 was closely related to carbapenem resistance. The 16S rRNA methylase gene armA was associated with resistance to amikacin, gentamicin, and tobramycin. The multidrug-resistant A. baumannii was closely related to various resistance genes. These results indicated that multidrug-resistant A. baumannii with type C strains was predominant in our hospital in this period.

Infection­associated bile acid disturbance contributes to macrophage activation in patients with cirrhosis.

Cirrhosis impairs macrophage function and disrupts bile acid homeostasis. Although bile acids affect macrophage function in patients with sepsis, whether and how the bile acid profile is changed by infection in patients with cirrhosis to modulate macrophage function remains unclear. The present study aimed to investigate the changes in the bile acid profile of patients with cirrhosis and infection and their effects on macrophage function. Serum was collected from 20 healthy subjects, 18 patients with cirrhosis and 39 patients with cirrhosis and infection. Bile acid profiles were detected using high­performance liquid chromatography­triple time­of­flight mass spectrometer. The association between bile acid changes and infection was analysed using receiver operating characteristic (ROC) curves. Infection­altered bile acids were used in combination with lipopolysaccharides (LPS) to stimulate RAW264.7/THP­1 cells in vitro. The migratory capacity was evaluated using wound healing and Transwell migration assays. The expression of Arg­1, iNOS, IκBα, phosphorylated (p­)IκBα and p65 was examined with western blotting and immunofluorescence, Tnfα, Il1b and Il6 mRNA was examined with RT­qPCR, and CD86, CD163 and phagocytosis was measured with flow cytometry. The ROC curves showed that decreased hyodeoxycholic acid (HDCA) and deoxycholic acid (DCA) levels were associated with infection. HDCA or DCA combined with LPS enhanced the phagocytic and migratory ability of macrophages, accompanied by upregulation of iNOS and CD86 protein expression as well as Tnfα, Il1b, and Il6 mRNA expression. However, neither HDCA nor DCA alone showed an effect on these phenotypes. In addition, DCA and HDCA acted synergistically with LPS to increase the expression of p­IκBα and the intranuclear migration of p65. Infection changed the bile acid profile in patients with cirrhosis, among which the reduction of DCA and HDCA associated most strongly with infection. HDCA and DCA enhanced the sensitivity of macrophage function loss to LPS stimulation. These findings suggested a potential role for monitoring the bile acid profile that could help manage patients with cirrhosis and infection.

Accelerated biological aging elevates the risk of cardiometabolic multimorbidity and mortality.

Associations of biological aging with the development and mortality of cardiometabolic multimorbidity (CMM) remain unclear. Here we conducted a multistate analysis in 341,159 adults of the UK Biobank. CMM was defined as the coexistence of two or three cardiometabolic diseases (CMDs), including type 2 diabetes, ischemic heart disease and stroke. Biological aging was measured using the Klemera-Doubal Method Biological Age and PhenoAge algorithms. Over a median follow-up of 8.84 years, biologically older participants demonstrated robust higher risks from first CMD to CMM and then to death. In particular, adjusted hazard ratios for first CMD to CMM and for CMM to death were 1.15 (95% confidence interval (CI): 1.12, 1.19) and 1.26 (95% CI: 1.17, 1.35) per 1 s.d. increase in PhenoAge acceleration, respectively. Compared with frailty, Framingham Risk Score and Systematic Coronary Risk Evaluation 2 (SCORE2), biological aging measures yielded consistent substantial associations with CMM development. Accelerated biological aging may help identify individuals with CMM risks, potentially enabling early intervention and subclinical prevention.

Clean air policy reduces the atherogenic lipid profile levels: Results from China Health Evaluation And risk Reduction through nationwide Teamwork (ChinaHEART) Study.

Evidence of the associations between long-term exposure to PM2.5 and O3 and human blood lipid concentrations is abundant yet inconclusive. Whether clean air policies could improve lipid profiles remains unclear. In total, 2979312 participants from a Chinese nationwide prospective study were included. For cross-sectional analyses, linear mixed-effects models were utilized to assess the associations of pollutants with lipid profiles (TC, LDL-C, TG, HDL-C). For longitudinal analyses, a quasi-experimental design and difference-in-differences models were employed to investigate the impact of China's Clean Air Act. In the cross-sectional analyses, each IQR increase in PM2.5 was associated with 2.49 % (95 % CI: 2.36 %, 2.62 %), 2.51 % (95 % CI: 2.26 %, 2.75 %), 3.94 % (95 % CI: 3.65 %, 4.23 %), and 1.54 % (95 % CI: 1.38 %, 1.70 %) increases in TC, LDL-C, TG, and HDL-C, respectively. For each IQR increase in O3, TC, LDL-C, TG, and HDL-C changed by 1.06 % (95 % CI: 0.95 %, 1.17 %), 1.21 % (95 % CI: 1.01 %, 1.42 %), 1.78 % (95 % CI: 1.54 %, 2.02 %), and -0.63 % (95 % CI: -0.76 %, -0.49 %), respectively. Longitudinal analyses showed that the intervention group experienced greater TC, LDL-C, and HDL-C reductions (1.77 %, 4.26 %, and 7.70 %, respectively). Our findings suggest that clean air policies could improve lipid metabolism and should be implemented in countries with heavy air pollution burdens.

Long-Term Air Pollution, Genetic Susceptibility, and the Risk of Depression and Anxiety: A Prospective Study in the UK Biobank Cohort.

BACKGROUND: Depression and anxiety are two mental disorders that are often comorbid. However, the associations of long-term air pollution exposure with depression and anxiety remain inconclusive. OBJECTIVE: We conducted a cross-sectional and prospective study to examine the associations of ambient exposure to particulate matter (PM) with a diameter of ≤2.5µm (PM2.5), ≤10µm (PM10), and 2.5-10µm (PMcoarse), nitrogen oxides (NOx), and nitrogen dioxide (NO2) with the risk of depression and anxiety in the UK Biobank. METHODS: This study included 398,241 participants from the UK Biobank, 128,456 of whom participated the 7-y online mental health survey. A total of 345,876 individuals were free of depression and anxiety at baseline; of those, 16,185 developed incident mental disorders during a median of 8.7 y of follow-up. Depression and anxiety were assessed using hospital admission records and mental health questionnaires. Associations of air pollution with prevalent and incident mental disorders were examined using logistic regression and Cox regression models, respectively. RESULTS: Elevated levels of the five air pollutants were associated with higher odds of mental disorders at baseline. Levels of four pollutants but not PMcoarse were also associated with higher odds and risks of mental disorders during follow-up; specifically, hazard ratios [HR, 95% confidence interval (CI)] of an interquartile range increase in PM2.5, PM10, NOx, and NO2 for incident mental disorders were 1.03 (95% CI: 1.01, 1.05), 1.06 (95% CI: 1.04, 1.08), 1.03 (95% CI: 1.01, 1.05), and 1.06 (95% CI: 1.04, 1.09), respectively. An air pollution index reflecting combined effects of pollutants also demonstrated a positive association with the risk of mental disorders. HR (95% CI) of incident mental disorders were 1.11 (95% CI: 1.05, 1.18) in the highest quintile group in comparison with the lowest quintile of the air pollution index. We further observed that the associations between air pollution and mental disorders differed by a genetic risk score based on single nucleotide polymorphisms previously associated with genetic susceptibility to mental disorders in the UK Biobank cohort. DISCUSSION: To our knowledge, this research is one of the largest cohort studies that demonstrates an association between mental health disorders and exposure to long-term air pollution, which could be further enhanced by genetic predisposition. https://doi.org/10.1289/EHP10391.

Genomic Characteristics and Phylogenetic Analyses of a Multiple Drug-Resistant Klebsiella pneumoniae Harboring Plasmid-Mediated MCR-1 Isolated from Tai'an City, China.

Klebsiella pneumoniae is a clinically common opportunistic pathogen that causes pneumonia and upper respiratory tract infection in humans as well as community-and hospital-acquired infections, posing significant threats to public health. Moreover, the insertion of a plasmid carrying the mobile colistin resistance (MCR) genes brings obstacles to the clinical treatment of K. pneumoniae infection. In this study, a strain of colistin-resistant K. pneumoniae (CRKP) was isolated from sputum samples of a patient who was admitted to a tertiary hospital in Tai'an city, China, and tested for drug sensitivity. The results showed that KPTA-2108 was multidrug-resistant (MDR), being resistant to 21 of 26 selected antibiotics, such as cefazolin, amikacin, tigecycline and colistin but sensitive to carbapenems via antibiotic resistance assays. The chromosome and plasmid sequences of the isolated strain KPTA-2108 were obtained using whole-genome sequencing technology and then were analyzed deeply using bioinformatics methods. The whole-genome sequencing analysis showed that the length of KPTA-2108 was 5,306,347 bp and carried four plasmids, pMJ4-1, pMJ4-2, pMJ4-3, and pMJ4-4-MCR. The plasmid pMJ4-4-MCR contained 30,124 bp and was found to be an IncX4 type. It was the smallest plasmid in the KPTA-2108 strain and carried only one resistance gene MCR-1. Successful conjugation tests demonstrated that pMJ4-4-MCR carrying MCR-1 could be horizontally transmitted through conjugation between bacteria. In conclusion, the acquisition and genome-wide characterization of a clinical MDR strain of CRKP may provide a scientific basis for the treatment of K. pneumoniae infection and epidemiological data for the surveillance of CRKP.

Accelerated biological aging and risk of depression and anxiety: evidence from 424,299 UK Biobank participants.

Theory predicts that biological processes of aging may contribute to poor mental health in late life. To test this hypothesis, we evaluated prospective associations between biological age and incident depression and anxiety in 424,299 UK Biobank participants. We measured biological age from clinical traits using the KDM-BA and PhenoAge algorithms. At baseline, participants who were biologically older more often experienced depression/anxiety. During a median of 8.7 years of follow-up, participants with older biological age were at increased risk of incident depression/anxiety (5.9% increase per standard deviation [SD] of KDM-BA acceleration, 95% confidence intervals [CI]: 3.3%-8.5%; 11.3% increase per SD of PhenoAge acceleration, 95% CI: 9.%-13.0%). Biological-aging-associated risk of depression/anxiety was independent of and additive to genetic risk measured by genome-wide-association-study-based polygenic scores. Advanced biological aging may represent a potential risk factor for incident depression/anxiety in midlife and older adults and a potential target for risk assessment and intervention.

Sini San ameliorates CCl4-induced liver fibrosis in mice by inhibiting AKT-mediated hepatocyte apoptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: Sini San (SNS) is recorded in Zhang Zhongjing's "Treatise on Typhoids" and is used in the treatment of non-alcoholic fatty liver disease, hepatitis, and other liver diseases, with good efficacy in liver fibrosis. However, its anti-liver fibrosis mechanism remains unclear. AIM OF THE STUDY: This study aimed to evaluate the ameliorative effect of SNS on carbon tetrachloride (CCl4)-induced liver fibrosis in mice and the underlying mechanisms. MATERIALS AND METHODS: The active ingredients in the water extract of SNS were determined using high-performance liquid chromatography (HPLC). CCl4-induced liver fibrosis mice were subsequently treated with different doses of SNS for 3 weeks, and AST, ALT, and T-BIL were detected in the serum. The pathological characteristics of the liver were observed using hematoxylin and eosin (H&E) and Masson's staining. Hepatocyte apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The proteins expression of PI3K, p-PI3K, AKT, p-AKT, FXR, caspase-8, Bax, and Bcl-2 was analyzed using western blotting and immunofluorescence. FXR mRNA expression was measured using quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR). Using network pharmacology and bioinformatics to search for active ingredients that regulate PI3K/AKT signaling in the SNS. The material basis for regulating PI3K/AKT signaling in SNS was searched using network pharmacology and bioinformatics. Based on the network pharmacology results, isorhamnetin or SNS-containing serum was added to HepG2 cells stimulated with TNF-α. The Cell Counting Kit (CCK)-8 assay was used to analyze cell viability and apoptosis of HepG2 cells was detected using flow cytometry. RESULTS: SNS reduced serum levels of AST, ALT and T-BIL, down-regulated caspase-8 protein expression and the ratio of Bcl-2/Bax protein expression, and improved apoptosis in liver fibrosis mice. In addition, SNS downregulated the ratio of p-PI3K/PI3K and p-AKT/AKT protein expression and increased FXR expression. Network pharmacology studies showed that quercetin, kaempferol and isorhamnetin in SNS can bind to AKT. In vitro experiments showed that isorhamnetin inhibited HepG2 cell apoptosis, upregulated FXR expression and suppressed AKT activity, whereas AKT inhibitors blocked the effects of isorhamnetin. The effect of the SNS-containing serum was similar to that of isorhamnetin. CONCLUSION: SNS ameliorated the progression of fibrosis and improved hepatocyte apoptosis in liver fibrosis mice. The anti-apoptotic mechanism was related to the inhibition of AKT-mediated down-regulation of FXR expression by its active ingredient, isorhamnetin.

Cardiovascular effects of wearing respirators against particulate matter: A randomized crossover trial.

Fine particles (PM2.5) are implicated as an important risk to cardiovascular health. N95 respirators had been widely used to provide protection by filtering particles. Yet the practical effects of wearing respirators have not been fully understood. This study aimed to evaluate the cardiovascular effects of respirator wearing against PM2.5 and underpin the understanding of the mechanisms of cardiovascular responses triggered by PM2.5. We conducted a randomized, double-blind crossover trial among 52 healthy adults in Beijing, China. Participants were exposed to outdoor PM2.5 for 2 h in alterations wearing true respirators (with membranes) or sham ones (without membranes). We measured ambient PM2.5 and tested the filtration efficiency of the respirators. We compared the heart rate variability (HRV), blood pressure and arterial stiffness indicators between the true respirator group and the sham respirator group. Concentrations of ambient PM2.5 during the 2-h exposure ranged from 4.9 to 255.0 µg/m3. The filtration efficiency of true respirators was 90.1 % and that of sham ones was 18.7 %. Between-group differences varied by pollution levels. On less polluted days (PM2.5< 75 µg/m3), participants wearing true respirators showed lower levels of HRV and higher levels of heart rate compared with those wearing sham respirators. These between-group differences were inconspicuous on heavily polluted days (PM2.5≥ 75 µg/m3). We found that a 10 µg/m3 increase in PM2.5 was associated with a 2.2 % to 6.4 % decrease in HRV, prominent at 1 h after the start of exposure. N95 respirators have good performance in reducing PM2.5 exposure. Short-term exposure to PM2.5 can induce very acute responses in autonomic nervous function. However, the overall effects of wearing respirators might be not always favorable to human health in terms of their inherent adverse effects, which seem dependent on the levels of air pollution. Precise individual protection recommendations warrant to be developed.

Phenotypic and Molecular Characterization of K54-ST29 Hypervirulent Klebsiella pneumoniae Causing Multi-System Infection in a Patient With Diabetes.

Worldwide, hypervirulent Klebsiella pneumoniae (hvKp) is one of the leading causes of multisystem infection. Serotype K54 has also been considered as one of the hvKp-associated capsular types that are rarely reported. In this study, we reported a K54-ST29 hvKp isolated from a 58-year-old male patient with diabetes in a teaching hospital in China. The patient rapidly developed sepsis and brain abscess, with a lethal multiple-organ-system failure due to K54 hvKp infection. This K54 hvKp isolate showed high level of toxicity in a mouse infection model and was susceptible to all the tested antibiotics. The isolate was fully sequenced, and its genome was compared with the available K54 K. pneumoniae genome. We predicted 133 virulence and pathogen-related genes, including those involved in fimbriae synthesis, iron transport, and enterobactin synthesis. Sequence alignment revealed >90% similarity among seven K54 K. pneumoniae strains. Our data suggest that community-acquired infection caused by hypervirulent K54 K. pneumoniae in patients with diabetes is a concern in East Asia.

Non-Structural Protein 3 of Duck Tembusu Virus Induces Autophagy via the ERK and PI3K-AKT-mTOR Signaling Pathways.

Despite autophagy's pivotal role in the replication of viruses such as duck Tembusu virus (DTMUV), which has caused massive economic losses to the poultry industry in the world, the specific relationships between DTMUV and cellular autophagy remain largely unknown. In response, we investigated the interactions between autophagy and DTMUV, the effects of the structural and non-structural proteins of DTMUV on autophagy, and the autophagy-related signaling pathways induced by DTMUV. Among the results, DTMUV increased the autophagy flux in duck embryo fibroblasts (DEF) and BHK-21 cells, while autophagy facilitated viral replication. After we pharmacologically induced autophagy with rapamycin (RAPA), the replication of DTMUV increased by 15.23-fold compared with the control group of DEF cells. To identify which DTMUV protein primarily induced autophagy, all three structural proteins and seven non-structural proteins of DTMUV were transfected into cells, and the results showed that non-structural protein 3 (NS3) induced significant autophagy in DEF cells. By means of Western blot, immunofluorescence, and transmission electron microscopy, we confirmed that NS3 protein could significantly induce autophagy and autophagy flux. Furthermore, we showed that NS3 induced autophagy in DEF cells through extracellular signal-regulated kinase 2 (ERK2) and phosphatidylinositol-3-kinase (PI3K)/AKT and the mammalian target of rapamycin (mTOR) signaling pathways using specific inhibitors and RNA interference assays. Finally, autophagy induced by NS3 promoted DTMUV replication. These results provide novel insight into the relationship between DTMUV and autophagy, broadening the current understanding of the molecular pathogenesis of DTMUV.

[Effects of polysaccharides isolated from Panax japonicus on immunosuppression mice].

OBJECTIVE: To investigate the immunomodulatory effects of polysaccharides from Panax japonicus on immunosuppressed mice. METHODS: Immunosuppressed murine model were established in Kuming mice induced by cyclophosphamide (Cy) and splenic indexes were evaluated. The proliferation activities of splenic lymphocyte were assayed by MTT and levels of serum hemolysin were confirmed by spectrophotometry. The antibody-secreting capabilities of splenocytes were assayed by quan-titative haemolysis of SRBC (QHS). The percentage of NK cells were analysed by flow cytometry (FCM). RESULTS: Polysaccharides of Panax japonicus significantly increased the splenic indexes, promoted the proliferation of splenic lymphocytes, enhanced QHS reaction, elevated the production of serum hemolysin and percentages of peripheral blood NK cells in Cy-induced immunosuppressed mice. CONCLUSION: Panax japonicus polysaccharides can recover immune function in the Cy-induced immunosuppressed mice.