Enhanced Biosynthesis of d-Allulose from a d-Xylose-Methanol Mixture and Its Self-Inductive Detoxification by Using Antisense RNAs in Escherichia coli.

d-Allulose, a C-3 epimer of d-fructose, has great market potential in food, healthcare, and medicine due to its excellent biochemical and physiological properties. Microbial fermentation for d-allulose production is being developed, which contributes to cost savings and environmental protection. A novel metabolic pathway for the biosynthesis of d-allulose from a d-xylose-methanol mixture has shown potential for industrial application. In this study, an artificial antisense RNA (asRNA) was introduced into engineered Escherichia coli to diminish the flow of pentose phosphate (PP) pathway, while the UDP-glucose-4-epimerase (GalE) was knocked out to prevent the synthesis of byproducts. As a result, the d-allulose yield on d-xylose was increased by 35.1%. Then, we designed a d-xylose-sensitive translation control system to regulate the expression of the formaldehyde detoxification operon (FrmRAB), achieving self-inductive detoxification by cells. Finally, fed-batch fermentation was carried out to improve the productivity of the cell factory. The d-allulose titer reached 98.6 mM, with a yield of 0.615 mM/mM on d-xylose and a productivity of 0.969 mM/h.

Transporter mining and metabolic engineering of Escherichia coli for high-level D-allulose production from D-fructose by thermo-swing fermentation.

D-Allulose is an ultra-low-calorie sweetener with broad market prospects in the fields of food, beverage, health care, and medicine. The fermentative synthesis of D-allulose is still under development and considered as an ideal route to replace enzymatic approaches for large-scale production of D-allulose in the future. Generally, D-allulose is synthesized from D-fructose through Izumoring epimerization. This biological reaction is reversible, and a high temperature is beneficial to the conversion of D-fructose. Mild cell growth conditions seriously limit the efficiency of producing D-allulose through fermentation. FryABC permease was identified to be responsible for the transport of D-allulose in Escherichia coli by comparative transcriptomic analysis. A cell factory was then developed by expression of ptsG-F, dpe, and deletion of fryA, fruA, manXYZ, mak, and galE. The results show that the newly engineered E. coli was able to produce 32.33 ± 1.33 g L-1 of D-allulose through a unique thermo-swing fermentation process, with a yield of 0.94 ± 0.01 g g-1 on D-fructose.

Development and verification of prognostic nomogram for ampullary carcinoma based on the SEER database.

Background: Ampullary carcinoma (AC) is a rare cancer of the digestive system that occurs in the ampulla at the junction of the bile duct and pancreatic duct. However, there is a lack of predictive models for overall survival (OS) and disease -specific survival (DSS) in AC. This study aimed to develop a prognostic nomogram for patients with AC using data from the Surveillance, Epidemiology, and End Results Program (SEER) database. Methods: Data from 891 patients between 2004 and 2019 were downloaded and extracted from the SEER database. They were randomly divided into the development group (70%) and the verification group (30%), and then univariate and multivariate Cox proportional hazards regression, respectively, was used to explore the possible risk factors of AC. The factors significantly related to OS and DSS were used to establish the nomogram, which was assessed via the concordance index (C-index), and calibration curve. An internal validation was conducted to test the accuracy and effectiveness of the nomogram. Kaplan-Meier calculation was used to predict the further OS and DSS status of these patients. Results: On multivariate Cox proportional hazards regression, the independent prognostic risk factors associated with OS were age, surgery, chemotherapy, regional node positive (RNP),extension range and distant metastasis with a moderate C-index of 0.731 (95% confidence interval (CI): 0.719-0.744) and 0.766 (95% CI: 0.747-0.785) in the development and verification groups, respectively. While, marital status, surgery, chemotherapy, regional node positive (RNP),extension range and distant metastasis were significantly linked to AC patients' DSS, which have a better C-index of 0.756 (95% confidence interval (CI): 0.741-0.770) and 0.781 (95% CI: 0.757-0.805) in the development and verification groups. Both the survival calibration curves of 3- and 5-year OS and DSS brought out a high consistency. Conclusion: Our study yielded a satisfactory nomogram showing the survival of AC patients, which may help clinicians to assess the situation of AC patients and implement further treatment.

Exploring the common mechanism of Yindan Xinnaotong soft capsule in the treatment of stroke and coronary heart disease through HIF1α-MMP9-mediated HIF1α signaling pathway / 药学学报

Coronary heart disease (CHD) and stroke are the most well-known cardiovascular diseases, which share many common pathological basis. Yindan Xinnaotong soft capsule (YDXNT) is a commonly used Chinese patent medicine in the treatment of stroke and CHD. However, its action of mechanism of co-treatment for stroke and CHD is still unclear. The aim of this study was to explore the common mechanism of YDXNT in co-treatment of CHD and stroke using network pharmacology, experimental verification and molecular docking. An integrated literature mining and databases of IPA, ETCM, HERB, Swiss Target Prediction, OMIM and GeneCards were used to screen and predict active ingredients and potential targets of YDXNT in co-treatment of CHD and stroke. The protein-protein interaction network, GO analysis and pathway analysis were analyzed by IPA software. The effect of YDXNT on core targets was verified by immunofluorescence. UPLC-QTOF/MS and molecular docking were used to screen and predict the main active constituents of YDXNT and their interactions with core targets. A total of 151 potential targets are predicted for YDXNT in co-treatment of CHD and stroke. Hypoxia-inducible factor-1α (HIF1α)-matrix metalloproteinase-9 (MMP9)-mediated HIF1α signaling pathway serves as one of the common mechanisms. YDXNT could reduce the increase of mitochondrial fluorescence intensity and the protein expression of HIF1α and MMP9 in HL-1 and HA induced by oxygen and glucose deprivation/reperfusion (OGD/R) in a dose-dependent manner. Baicalin may be the material basis for treating stroke and CHD with YDXNT. In conclusion, the HIF1α signaling pathway is one of the common key mechanisms of YDXNT in the co-treatment of stroke and CHD. The study provides support and basis for the in-depth scientific connotation of the traditional Chinese medicine theory of "same treatment to different diseases".

Methanol-Dependent Carbon Fixation for Irreversible Synthesis of d-Allulose from d-Xylose by Engineered Escherichia coli.

d-Allulose is a rare hexose with great application potential, owing to its moderate sweetness, low energy, and unique physiological functions. The current strategies for d-allulose production, whether industrialized or under development, utilize six-carbon sugars such as d-glucose or d-fructose as a substrate and are usually based on the principle of reversible Izumoring epimerization. In this work, we designed a novel route that coupled the pathways of methanol reduction, pentose phosphate (PP), ribulose monophosphate (RuMP), and allulose monophosphate (AuMP) for Escherichia coli to irreversibly synthesize d-allulose from d-xylose and methanol. After improving the expression of AlsE by SUMO fusion and regulating the carbon fluxes by knockout of FrmRAB, RpiA, PfkA, and PfkB, the titer of d-allulose in fed-batch fermentation reached ≈70.7 mM, with a yield of ≈0.471 mM/mM on d-xylose or ≈0.512 mM/mM on methanol.

Metabolically Engineered Escherichia coli for Conversion of D-Fructose to D-Allulose via Phosphorylation-Dephosphorylation.

D-Allulose is an ultra-low calorie sweetener with broad market prospects. As an alternative to Izumoring, phosphorylation-dephosphorylation is a promising method for D-allulose synthesis due to its high conversion of substrate, which has been preliminarily attempted in enzymatic systems. However, in vitro phosphorylation-dephosphorylation requires polyphosphate as a phosphate donor and cannot completely deplete the substrate, which may limit its application in industry. Here, we designed and constructed a metabolic pathway in Escherichia coli for producing D-allulose from D-fructose via in vivo phosphorylation-dephosphorylation. PtsG-F and Mak were used to replace the fructose phosphotransferase systems (PTS) for uptake and phosphorylation of D-fructose to fructose-6-phosphate, which was then converted to D-allulose by AlsE and A6PP. The D-allulose titer reached 0.35 g/L and the yield was 0.16 g/g. Further block of the carbon flux into the Embden-Meyerhof-Parnas (EMP) pathway and introduction of an ATP regeneration system obviously improved fermentation performance, increasing the titer and yield of D-allulose to 1.23 g/L and 0.68 g/g, respectively. The E. coli cell factory cultured in M9 medium with glycerol as a carbon source achieved a D-allulose titer of ≈1.59 g/L and a yield of ≈0.72 g/g on D-fructose.

Restoration Efficacy of Picea likiangensis var. rubescens Rehder & E. H. Wilson Plantations on the Soil Microbial Community Structure and Function in a Subalpine Area.

The knowledge concerning the relationship between vegetation restoration and soil microorganisms is limited, especially at high altitudes. In order to evaluate the restoration efficacy of the reforestation on the soil microbial community, we have examined vegetation composition, edaphic properties and structure and function of different soil microbial groups in two different aged (25- and 40-year-old) Picea likiangensis var. rubescens Rehder & E. H. Wilson (P. rubescens) plantations and the primeval coniferous forest (PCF) dominated by Abies squamata Masters by plot-level inventories and sampling in western Sichuan Province, China. Our results suggested that only the fungal samples in 25-year-old P. rubescens plantation could be distinguished from those in the PCF in both structure and function. The structure and function of the fungal community recovered relatively slowly compared with bacterial and archaeal communities. In addition to the soil chemical properties and tree species composition, the shrub composition was also a key factor influencing the soil microbial community. The P. rubescens plantations were conducive to restoring the soil microbial community in both structure and function. However, there were uncertainties in the variations of the bacterial and archaeal communities with increasing the P. rubescens plantation age.

Nitrogen Fertilization Modified the Responses of Schima superba Seedlings to Elevated CO2 in Subtropical China.

There are very few studies about the effects of relatively higher CO2 concentration (e.g., 1000 µmol·mol-1) or plus N fertilization on woody plants. In this study, Schima superba seedings were exposed to ambient or eCO2 (550, 750, and 1000 µmol·mol-1) and N fertilization (0 and 10 g·m-2·yr-1, hereafter: low N, high N, respectively) for one growth season to explore the potential responses in a subtropical site with low soil N availability. N fertilization strongly increased leaf mass-based N by 118.38%, 116.68%, 106.78%, and 138.95%, respectively, in different CO2 treatments and decreased starch, with a half reduction in leaf C:N ratio. Leaf N was significantly decreased by eCO2 in both low N and high N treatments, and N fertilization stimulated the decrease of leaf N and mitigated the increase of leaf C:N by eCO2. In low N treatments, photosynthetic rate (Pn) was maximized at 733 µmol·mol-1 CO2 in August and September, while, in high N treatments, Pn was continuously increased with elevation of CO2. N fertilization significantly increased plant biomass especially at highly elevated CO2, although no response of biomass to eCO2 alone. These findings indicated that N fertilization would modify the response of S. superba to eCO2.

MG-132 attenuates cardiac deterioration of viral myocarditis via AMPK pathway.

BACKGROUND: Coxsackievirus B3 (CVB3) is the primary cause of infectious myocarditis. Aggressive immunological activation and apoptosis of myocytes contributes to progressive dysfunction of cardiac contraction and poor prognosis. MG-132, a proteasome inhibitor, regulates mitochondrial-mediated intrinsic myocardial apoptosis and downregulates NF-κB-mediated inflammation. Here, we determined whether AMPK pathway participates in MG-132-mediated myocardial protection in viral-induced myocarditis. METHODS AND RESULTS: Acute viral myocarditis models were established by intraperitoneal inoculation of CVB3 in male BALB/c mice. Myocarditis and age-matched control mice were administered MG-132 and/or BML-275 dihydrochloride (BML) (AMPK antagonist) intraperitoneally daily from the day following CVB3 inoculation. MG-132 improved hemodynamics and inhibited the structural remodeling of the ventricle in mice with myocarditis, while BML largely blunted these effects. TUNEL staining and immunochemistry suggested that MG-132 exerts anti-apoptotic and anti-inflammatory effects against CVB3-induced myocardial injuries. BML attenuated the effects of MG-132 on anti-apoptosis and anti-inflammation. CONCLUSION: MG-132 modulated apoptosis and inflammation, improved hemodynamics, and inhibited the structural remodeling of ventricles in a myocarditis mouse model via regulation of the AMPK signal pathway.

Duration of dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent: systematic review and network meta-analysis.

OBJECTIVE: To evaluate the efficacy and safety of standard term (12 months) or long term (>12 months) dual antiplatelet therapy (DAPT) versus short term (<6 months) DAPT after percutaneous coronary intervention (PCI) with drug-eluting stent (DES). DESIGN: Systematic review and network meta-analysis. DATA SOURCES: Relevant studies published between June 1983 and April 2018 from Medline, Embase, Cochrane Library for clinical trials, PubMed, Web of Science, ClinicalTrials.gov, and Clinicaltrialsregister.eu. REVIEW METHODS: Randomised controlled trials comparing two of the three durations of DAPT (short term, standard term, and long term) after PCI with DES were included. The primary study outcomes were cardiac or non-cardiac death, all cause mortality, myocardial infarction, stent thrombosis, and all bleeding events. RESULTS: 17 studies (n=46 864) were included. Compared with short term DAPT, network meta-analysis showed that long term DAPT resulted in higher rates of major bleeding (odds ratio 1.78, 95% confidence interval 1.27 to 2.49) and non-cardiac death (1.63, 1.03 to 2.59); standard term DAPT was associated with higher rates of any bleeding (1.39, 1.01 to 1.92). No noticeable difference was observed in other primary endpoints. The sensitivity analysis revealed that the risks of non-cardiac death and bleeding were further increased for ≥18 months of DAPT compared with short term or standard term DAPT. In the subgroup analysis, long term DAPT led to higher all cause mortality than short term DAPT in patients implanted with newer-generation DES (1.99, 1.04 to 3.81); short term DAPT presented similar efficacy and safety to standard term DAPT with acute coronary syndrome (ACS) presentation and newer-generation DES placement. The heterogeneity of pooled trials was low, providing more confidence in the interpretation of results. CONCLUSIONS: In patients with all clinical presentations, compared with short term DAPT (clopidogrel), long term DAPT led to higher rates of major bleeding and non-cardiac death, and standard term DAPT was associated with an increased risk of any bleeding. For patients with ACS, short term DAPT presented similar efficacy and safety with standard term DAPT. For patients implanted with newer-generation DES, long term DAPT resulted in more all cause mortality than short term DAPT. Although the optimal duration of DAPT should take personal ischaemic and bleeding risks into account, this study suggested short term DAPT could be considered for most patients after PCI with DES, combining evidence from both direct and indirect comparisons. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018099519.

Elevated O3 alters soil bacterial and fungal communities and the dynamics of carbon and nitrogen.

Although many studies have reported the negative effects of elevated O3 on plant physiological characteristics, the influence of elevated O3 on below-ground processes and soil microbial functioning is less studied. In this study, we examined the effects of elevated O3 on soil properties, soil microbial biomass, as well as microbial community composition using high-throughput sequencing. Throughout one growing season, one-year old seedlings of two important endemic trees in subtropical China: Taxus chinensis (Pilger) Rehd. var. chinensis, and Machilus ichangensis Rehd. Et Wils, were exposed to charcoal-filtered air (CF as control), 100 nl l-1 (E100) or 150 nl l-1 (E150) O3-enriched air, in open top chambers (OTCs). We found that only higher O3 exposure (E150) significantly decreased soil microbial biomass carbon and nitrogen in M. ichangensis, and the contents of organic matter were significantly decreased by E150 in both tree species. Although both levels of O3 exposure decreased NO3-N in T. chinensis, only E150 increased NO3-N in M. ichangensis, and there were no effects of O3 on NH4-N. Moreover, elevated O3 elicited changes in soil microbial community structure and decreased fungal diversity in both M. ichangensis and T. chinensis. However, even though O3 exposure reduced bacterial diversity in M. ichangensis, no effect of O3 exposure on bacterial diversity was detected in soil grown with T. chinensis. Our results showed that elevated O3 altered the abundance of bacteria and fungi in general, and in particular reduced nitrifiers and increased the relative abundance of some fungal taxa capable of denitrification, which may stimulate N2O emissions. Overall, our findings indicate that elevated O3 not only impacts the soil microbial community structure, but may also exert an influence on the functioning of microbial communities.

Geno-typing and drug resistance gene analysis of Salmonella in Chinese PLA General Hospital from 2015 to 2017 / 中华检验医学杂志

Objective To understand the prevalence of Salmonella and the characteristics of drug resistance genes in General Hospital of People's Liberation Army, and to provide evidence for the prevention and treatment of Salmonella infection. Methods A retrospective study was conducted to collect 78 clinical isolates of Salmonella from 2015 to 2017. The age of the patients was 49 ± 21 years old. The infected patients were mainly young and middle-aged. The clinical samples mainly came from feces and venous blood, accounting for 44.87％(35/78) and 33.33％(26/78), respectively. After serotype identification, drug sensitivity test and whole genome sequencing, multilocus sequence typing and drug resistance genotyping were performed. Cluster of Cefotaxime or Ciprofloxacin resistant Salmonella was analyzed. Results Salmonella group D (53.85％) and Salmonella group C (21.79％) were dominant Salmonella serotype. ST11 was mainly ST type. Drug sensitivity test showed that the multidrug resistance rate of Salmonella was 64.11％ (50/78). The sensitivity to all antimicrobial agents' rate was 25.64 (20/78). The resistance rate of Salmonella to nalidixic acid was 65.38％(51/78). The most common drug resistance gene of Salmonella was extended-spectrum β-lactam drug resistance gene, accounting for 78.21％ (61/78). Conclusions The ST-type and carrying resistance genes of Salmonella in this hospital were diverse. Most pathogens were multi-drug resistant to antimicrobial agents. Molecular typing and drug resistance gene analysis of Salmonella and construction of resistant strains to determine the inheritance of Salmonella relationships have a certain clinical significance.

Effects of Elevated Ozone Levels on Photosynthesis, Biomass and Non-structural Carbohydrates of Phoebe bournei and Phoebe zhennan in Subtropical China.

To assess the impacts of ozone (O3) on carbon metabolism of subtropical broadleaved tree species, seedlings of Phoebe bournei and Phoebe zhennan were exposed to elevated O3 levels in open-top chambers (OTCs) from June to November 2014. Three treatments were conducted in nine total OTCs, including charcoal-filter air (CF) as a control treatment, low O3 treatment 'O3-1' (∼100 nl l-1), and high O3 treatment 'O3-2' (∼150 nl l-1). Our findings demonstrated that elevated O3 levels significantly decreased the net photosynthesis rates (Pn ) and leaf, root, and total biomass of both species, while it did not significantly affect the root/shoot ratio in P. bournei and P. zhennan. O3-1 treatments significantly increased water soluble carbohydrates (WSC) in leaves of both tree species, while only increased the total non-structural carbohydrates (TNC) and starch in leaves of P. bournei; effects on P. zhennan were equivalent in comparison to the control treatment (CF). Likewise, there was no effect of treatment on the polysaccharide content of both tree species. The contents of polysaccharide, starch contents in fine roots of both species, and TNC in fine roots of P. bournei increased significantly in O3-1 compared to CF. O3-2 treatment significantly decreased starch and TNC in the fine roots of P. bournei, and significantly decreased polysaccharide, starch, WSC, and TNC in the fine roots of P. zhennan. Elevated O3 had no effects on leaf polysaccharide in both species, but O3-1 significantly increased polysaccharide in the fine roots of both species, and O3-1 significantly increased WSC in the leaves while decreased that in the fine roots of both species. These results suggested that elevated O3 levels have significant impacts on the carbon metabolism of both tree species in our study, with differential responses between tree species and among leaves and roots.

Effects of elevated O3 on physiological and biochemical responses in three kinds of trees native to subtropical forest in China during non-growing period.

Numerous studies have documented the negative effects of ozone (O3) on tree species in growing season, however, little is done in non-growing season. Three evergreen tree species, Phoebe bournei (Hemsl.) Yang (P. bournei), Machilus pauhoi Kanehira (M. pauhoi) and Taxus chinensis (Pilger) Rehd (T. chinensis), were exposed to non-filtered air, 100 nmol mol-1 O3 air (E1) and 150 nmol mol-1 O3 air (E2) in open-top chambers in subtropical China. In the entire period of experiment, O3 fumigation decreased net photosynthesis rate (Pn) through stomatal limitation during the transition period from growing to non-growing season (TGN), and through non-stomatal limitation during the period of non-growing season (NGS) in all species tested. Meanwhile, O3 fumigation reduced and delayed the resilience of Pn in all species tested during the transition period from non-growing to growing season (TNG). O3 fumigation significantly decreased chlorophyll contents during NGS, whereas no obvious injury symptoms were observed till the end of experiment. O3 fumigation induced increases in levels of malondialdehyde, superoxide dismutase, total phenolics and reduced ascorbic acid, and changes in four plant endogenous hormones as well in all species tested during NGS. During NGS, E1 and E2 reduced Pn by an average of 80.11% in P. bournei, 94.56% in M. pauhoi and 12.57% in T. chinensis, indicating that the O3 sensitivity was in an order of M. pauhoi > P. bournei > T. chinensis. Overall, O3 fumigation inhibited carbon fixation in all species tested during NGS. Furthermore, O3-induced physiological activities also consumed the dry matter. All these suggested that elevated O3, which is likely to come true during NGS in the future, will adversely affect the accumulation of dry matter and the resilience of Pn during TNG in evergreen tree species, and further inhibit their growth and development in the upcoming growing season.

How important is woody tissue photosynthesis in EuCahetus dunnii Maiden and Osmanthus fragrans (Thunb.) Lour. under O3 stress?

Numerous studies have demonstrated the negative effects of elevated O3 on leaf photosynthesis. Within trees, a portion of respired CO2 is assimilated by woody tissue photosynthesis, but its response to elevated O3 remains unclear. Saplings of two evergreen tree species, EuCahetus dunnii Maiden (E. dunnii) and Osmanthus fragrans (Thunb.) Lour. (O. fragrans), were exposed to non-filtered air (NF), 100 nmol mol-1 O3 air (E1) and 150 nmol mol-1 O3 air (E2) in open-top chambers from May 5 to September 5, 2016 (8 h a day; 7 days a week) in subtropical China. In this study, O3 fumigation significantly reduced leaf net photosynthesis rate in both two tree species on most measurements. However, compared with leaf net photosynthesis rate, woody tissue gross photosynthesis rate showed less negative response to O3 fumigation and was even stimulated to increase. Refixation rate reflects the utilization efficiency of the respired CO2 by woody tissue photosynthesis. During the experiment period, E1 and E2 both increased refixation rate in O. fragrans compared with NF. Whereas for E. dunnii, E1 increased refixation rate until 81 days after starting of fumigation and then decreased it, and E2 decreased it all the time. Refixation rate had a significant positive correlation with woody tissue chlorophyll contents, indicating that the response of refixation rate to elevated O3 may relate to chlorophyll contents. All these suggested that under O3 fumigation, when atmospheric CO2 uptake and fixation by leaf is limited, woody tissue photosynthesis can contribute more to the total carbon assimilation in trees. The findings help to understand the significance of woody tissue photosynthesis under elevated O3 conditions.

Expressions and significances of LIF and RANTES in mouse model of bloodstream infection with single pathogen / 临床检验杂志

Objective To investigate the expressions of leukaemia inhibitory factor (LIF) and regulated upon activation,normal T cell expressed and secreted factor (RANTES) in mice with bloodstream infection by 4 different single pathogen and provide research basis for the early diagnosis of bacteriogenous bloodstream infection.Methods CD-1 (ICR,Institute of Cancer Research) mouse models of bloodstream infection with the standard strains of Staphylococcus aureus (S.aureus),Enterococcus faecalis (E.faecalis),Escherichia coli (E.coli) and Klebsiella pneumonia(K,pneumoniae) were established.The serum samples were collected at the 0.5,1,3,6,12,24 and 48 hours after infection and the concentrations of LIF and RANTES in mouse serum of experimental groups and control were detected by Luminex liquid chip system.Results The median lethal dose (LD50) of S.aureus,E.faecalis,E.coli and K.pneumoniae were 8.1 × 108/mL,9.6 × 108/mL,8.1 × 108/mL and 1.1 × 109/mL,respectively.The concentration of serum LIF was significantly increased in 1 hour after infection.The peak concentrations of LIF in the four groups were (51.6±5.0),(73.2±20.8),(7.3 ±0.9)and (6.1 ± 1.2) pg/mL respectively,and the differences were statistically significant compared with the control group (P ＜ 0.01).The concentrations of RANTES in E.faecalis group,E.coli group and K.pneumoniae group were increased after infection for 1 hour and increased significantly after infection for 3 hours.The increased concentrations of RANTES in E.coli group and K.pneumoniae group were more than those in S.aureus group and E.faecalis group.The peak concentrations of RANTES in S.aureus group,E.faecalis group,E.coli group and K.pneumoniae group were (1 929.0-± 25.2),(1 218.1 ± 227.4),(55.7 ± 10.0) and (179.2 ± 9.2)pg/mL,and the differences were statistically significant compared with the control group (P ＜ 0.01).Conclusion The concentrations of LIF and RANTES increased obviously in 1 h after the bacteria entered bloodstream.After 2 days of infections,the levels of LIF and RANTES in E.coli group and K.pneumoniae group were significantly higher than those in S.aureus group and the E.faecalis group.Combined detections of LIF and RANTES may be of certain values to differentiate the infections caused by the pathogens between gram positive and gram negative bacteria.

Analysis of serum peptides in Candida albicans bloodstream infection based on MALDI-TOF MS / 解放军医学杂志

Objective To analyze the fingerprints of serum peptides in bloodstream infection induced by Candida albicans (C.albicans),with matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS),and establish the corresponding diagnostic model Methods To establish ICR mice model of C.albicans bloodstream infection,and collect the serum samples which were purified by weak cation exchange beads.The serum peptide finger printing was recognized by MALDITOF MS,and BioExplorer software was used for analysis between infection group and normal control group.Furthermore,the peptide fingerprints were analyzed between C.albicans infection group,Escherichia coli (E.coli) infection group and Staphylococcus aureus (S.aureus) infection group.Results Comparison between C.albicans infection group and normal control group,there were 135 polypeptide peaks,of which 5 polypeptides up-regulated,6 down-regulated and 7 up-regulated first and down-regulated afterwards.The diagnostic model was established by combination of 6 peaks (i.e.m/z 1610.9,1742.3,2666.4,2778.0,3345.1 and 4528.8),which possessed an accurate rate of 80.0％ in diagnosis of C.albicans infection.It was found by comprehensive comparison between C.albicans,E.coli and S.aureus infection groups that there were 5 polypeptides expressed collectively,i.e.m/z1513.8,2910.8,3538.1,3884.9 and 5007.3.Conclusions MALDI-TOF MS can be used to distinguish the C.albicans infection and normal polypeptide peaks.The collective polypeptides expressed in the infection groups can be further used to diagnose the infection.Establishment of corresponding diagnostic models may be helpful for early diagnosis of fungal bloodstream infection and provide a basis for reasonable clinical medication.

Early detection of the bloodstream infection bacteria based on MALDI-TOF MS / 解放军医学杂志

Objective To establish a clinical method for early detection of the bloodstream infection bacteria based on matrix-assisted laser ionization time of flight mass spectrometry (MALDI-TOF MS).Methods After consulting the Laboratory Information System statistics and domestic related literature,We chose 10 kinds of bacteria (Escherichia coli.,Pseudomonas aeruginosa,Acinetobacter baumannii,Klebsiella pneumoniae,Enterococcus faecium,Enterococcus faecalis,Staphylococcus aureus and Staphylococcus epidermidis,Proteus mirabilis,Streptococcus pneumoniae) as target.The MALDI-TOF MS was established using simulated bacterial infection blood samples.From March to May 2017,33 blood samples of suspected sepsis patients from Emergency Department,General Hospital of PLA,were tested.Results The MALDI-TOF MS whose detecting sensitivity was 100CFU/ml had the same negative detection rate with the blood culture (27cases/27cases,100％).Besides the 2 samples of Morganella morganii infection and Staphylococcus hominis infection were out of the range,the results of the remaining 4 positive samples were consistent (100％).Conclusion Compared to the blood culture and biochemical identification,MALDI-TOF MS can rapidly detect 10 kinds of bloodstream infection bacteria with high sensitivity and high accuracy.

Physiological and biochemical responses of Machilus ichangensis Rehd. et Wils and Taxus chinensis (Pilger) Rehd. to elevated O3 in subtropical China.

Considerable researches have documented the negative effects of ozone on woody species in North America and Europe; however, little is known about how woody tree species respond to elevated O3 in subtropical China, and most of the previous studies were conducted using pot experiment. In the present study, Machilus ichangensis Rehd. et Wils (M. ichangensis) and Taxus chinensis (Pilger) Rehd. (T. chinensis), evergreen tree species in subtropical China, were exposed to non-filtered air (NF), 100 nmol mol-1 O3 (E1) and 150 nmol mol-1 O3 (E2), in open-top chambers under field conditions from 21st March to 2nd November 2015. In this study, O3 fumigation significantly reduced net photosynthesis rate (Pn) in M. ichangensis in the three measurements and in T. chinensis in the last measurement. Also, non-stomatal factors should be primarily responsible for the decreased Pn. O3 fumigation-induced increase in malondialdehyde, superoxide dismutase, and reduced ascorbic acid levels indicated that antioxidant defense mechanism had been stimulated to prevent O3 stress and repair the oxidative damage. Yet, the increase of antioxidant ability was not enough to counteract the harm of O3 fumigation. Because of the decrease in CO2 assimilation, the growth of the two tree species was restrained ultimately. The sensitivity of the two tree species to O3 can be determined: M. ichangensis > T. chinensis. It suggests a close link between the rising O3 concentrations and the health risk of some tree species in subtropics in the near future.

[Effects of Continuous Application of Sewage Sludge Compost on Heavy Metals Accumulation and Mobility Characteristics in Soil Profile and on Heavy Metals Uptake of Wheat].

The use of sewage sludge compost(SSC)as fertilizer may cause increased leaching due to its high content of heavy metals and thus pose a threat to groundwater quality. The effect of SSC application on heavy metals leaching in calcareous soils has been studied in field trials, which provides basis for determining heavy metals environmental capacity and preventing metal pollution in farmland soil scientifically. The results indicated that the contents of Cu, Zn elevated obviously with the increase of the age and the dosage of SSC utilization in the topsoil(0-15 cm) under 4-year continuous application of SSC. Under higher levels of the compost treatment, the heavy metals Cu and Zn were found to migrate into the 15-30 cm soil and 60-90 cm soil under the experimental condition. Nevertheless, the majority of Cu and Zn from SSC accumulated in topsoil and the highest accumulation rates could reach 75.3% for Cu and 85.9% for Zn. The contents of Cd, Pb increased significantly in topsoil after 4-year continuous application of SSC, and their increases could reach 57.2%-165.2% for Cd and 13%-34% for Pb compared with CK. At 60-90 cm soil, the contents of Cr, As and Pb were also significantly higher than those in CK treatment. Application of SSC not only caused accumulation of some heavy metals in topsoil but also leached heavy metals located in the subsurface soil down in this experiment. Continuous utilization of SSC increased Zn concentration of wheat grain, and the increase could reach 13.3%-47.9%. For the concentrations of Cr and Pb in wheat grain, the values exceeded the national food and healthy standards value (GB 2762-2012) in part of compost treatments. The cumulative ratio of heavy metals carried out by wheat were all below 10% after 4-year experiment, wheat grain carried much more Cu, Zn out than wheat straw, but it was opposite for Cr, As, Cd, Pb. The cumulative ratio of heavy metals carried by wheat decreased with the increasing level of SSC utilization. The amounts of heavy metals migrated to deeper soil should be considered when determining the environmental capacity of heavy metals in farmland soil.