Publications by authors named "Xinping Chen"

86 Publications

Transcriptional Start Site Coverage Analysis in Plasma Cell-Free DNA Reveals Disease Severity and Tissue Specificity of COVID-19 Patients.

Front Genet 2021 28;12:663098. Epub 2021 May 28.

BGI-Shenzhen, Shenzhen, China.

Symptoms of coronavirus disease 2019 (COVID-19) range from asymptomatic to severe pneumonia and death. A deep understanding of the variation of biological characteristics in severe COVID-19 patients is crucial for the detection of individuals at high risk of critical condition for the clinical management of the disease. Herein, by profiling the gene expression spectrum deduced from DNA coverage in regions surrounding transcriptional start site in plasma cell-free DNA (cfDNA) of COVID-19 patients, we deciphered the altered biological processes in the severe cases and demonstrated the feasibility of cfDNA in measuring the COVID-19 progression. The up- and downregulated genes in the plasma of severe patient were found to be closely related to the biological processes and functions affected by COVID-19 progression. More importantly, with the analysis of transcriptome data of blood cells and lung cells from control group and cases with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection, we revealed that the upregulated genes were predominantly involved in the viral and antiviral activity in blood cells, reflecting the intense viral replication and the active reaction of immune system in the severe patients. Pathway analysis of downregulated genes in plasma DNA and lung cells also demonstrated the diminished adenosine triphosphate synthesis function in lung cells, which was evidenced to correlate with the severe COVID-19 symptoms, such as a cytokine storm and acute respiratory distress. Overall, this study revealed tissue involvement, provided insights into the mechanism of COVID-19 progression, and highlighted the utility of cfDNA as a noninvasive biomarker for disease severity inspections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fgene.2021.663098DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8194351PMC
May 2021

Soil type shapes the antibiotic resistome profiles of long-term manured soil.

Sci Total Environ 2021 Sep 27;786:147361. Epub 2021 Apr 27.

College of Resources and Environment, Southwest University, Chongqing 400716, China. Electronic address:

Animal manure fertilization facilitates the proliferation and dissemination of antibiotic resistance genes (ARGs) in soil, posing high risks to humans and ecosystem health. Although studies suggest that soil types could shape the ARG profiles in greenhouse soil, there is still a lack of comparative studies on the fate of ARGs in different types of manured soils under field trials. Thus, a metagenomic approach was used to decipher the fate of ARGs in 12-year long-term fertilized (inorganic fertilizer, compost manure and a mix of them) acidic, near-neutral and alkaline soils. A total of 408 unique ARG subtypes with multidrug, glycopeptide, beta-lactam and aminoglycoside resistance genes were identified as the most universal ARG types in all soil samples. Genes conferred to beta-lactam was the predominant ARG type in all the manure-amended soils. Genomic and statistical analyses showed that manure application caused the enrichment of 98 and 91 ARG subtypes in acidic and near-neutral soils, respectively, and 8 ARG subtypes in alkaline soil. The abundances of Proteobacteria (acidic and near-neutral soils) and Actinobacteria (alkaline soil), which are the potential hosts of ARGs, were clearly increased in manured soils. Random forest modelling and Pearson correlation analysis revealed that the soil properties (pH and bio-available Zn) and mobile genetic elements had considerable impacts on the transmission of ARGs. A structural equation model further indicated that soil types shaped the ARG profiles by significantly (P < 0.01) influencing the soil properties, bacterial abundance and bacterial diversity, where bacterial abundance was the major factor influencing the ARG profiles. This study systematically explored the mechanisms shaping the ARG profiles of long-term manured soils, and this information could support strategies to manage the dissemination of ARGs in different soil types.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2021.147361DOI Listing
September 2021

Uterine necrosis, infection, and subinvolution: complications observed after combined application of modified B-Lynch suture and vascular ligation.

J Int Med Res 2021 May;49(5):3000605211010730

Department of Obstetrics & Gynecology, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.

Compression sutures are primarily used to treat atonic postpartum hemorrhage. We herein describe three cases of selective arterial ligation combined with B-Lynch or modified B-Lynch suture for the treatment of intractable postpartum hemorrhage unresponsive to available conservative interventions. Three pregnant women underwent a cesarean section for a macrosomic fetus, fetal distress, and oligohydramnios, respectively. All three women developed intractable postpartum hemorrhage due to uterine atony with no chance of embolization therapy. B-Lynch or modified B-Lynch suture and additional selective arterial ligation were performed using braided absorbable suture. The first woman developed postoperative hematometra and infection without response to drainage and antibiotic therapy. Although laparoscopic exploration was performed to loosen the suture line and drain the hematometra and pyometra, the necrosis and infection could not be controlled. Subtotal hysterectomy was therefore conducted, and the necrotic uterine adnexa was removed. The other two women developed subinvolution of the uterus resulting in prolonged menstruation and amenorrhea, although the uterus was preserved and the bleeding was controlled. Modified B-Lynch suture combined with vascular ligation is an invaluable technique for women with severe intractable postpartum hemorrhage. However, it can lead to serious complications such as uterine necrosis, infection, and subinvolution.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/03000605211010730DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8113939PMC
May 2021

Nitrogen leaching and grey water footprint affected by nitrogen fertilization rate in maize production: a case study of Southwest China.

J Sci Food Agric 2021 Apr 19. Epub 2021 Apr 19.

College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, China.

Background: Effective nitrogen (N) management measures are required to control environmental problems caused by N fertilizer use in intensive maize production systems. Soil N losses associated with high precipitation and over-fertilization in maize production can cause substantial environmental problems, whereas there is a lack of quantitative data and effective study countermeasures. A 2-year field study was conducted in the subtropical maize production system in Southwest China to quantify N leaching under varying N application rates of 0, 90, 180, 270 and 360 kg N ha yr .

Results: The results indicated that N leaching accounted for 16-38% of N fertilizer input. For farmer practice treatment (360 kg N ha yr ), N leaching loss was high at 110 kg N ha yr and accounted for 31% of the N applied. As an indicator of the ambient water quality pollution, the grey water footprint across all treatments ranged from 376 to 1092 m Mg , with an average of 695 m Mg . Reducing N rate to agronomically optimized treatment (180 kg N ha yr ) significantly decreased N leaching by 77%, and maintained high grain yield of 8.1 Mg ha . The grey water footprint was reduced by 52-63% with N rates from 270 or 360 kg N ha yr to 180 kg N ha yr .

Conclusion: Nitrogen surplus (applied N rate minus N uptake by maize) resulted in higher soil residual nitrate concentration and consequently high N leaching. High precipitation and low soil pH were the main ecological factors leading to high N leaching.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jsfa.11263DOI Listing
April 2021

Life cycle assessment of a long-term multifunctional winter wheat-summer maize rotation system on the North China Plain under sustainable P management.

Sci Total Environ 2021 Aug 17;783:147039. Epub 2021 Apr 17.

College of Resources and Environmental Science, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing 100193, China. Electronic address:

In sustainable agriculture, sufficient crop yields and nutrients must be produced while maintaining environmental protection. Considering the role of phosphorus (P) fertilizer in influencing crops yield and environmental security, life cycle assessment was used to examine the environmental impacts of long-term P application on the grain yield and nutritional quality of winter wheat and summer maize. Thus, a long-term field experiment with six P application rates for winter wheat (0, 25, 50, 100, 200, and 400 kg P ha) and summer maize (0, 12.5, 25, 50, 100, and 200 kg P ha) was conducted on the North China Plain (NCP). The results showed that the cradle-to-farm gate eutrophication potential (EP), energy depletion (ED), and P depletion (PD) were significantly affected by the P application rate applied in winter wheat and summer maize production. The critical P rate required to ensure food security for wheat and maize was in line with the optimal rate for sustainable environmental development in terms of grain production and nutrient levels. On the NCP, the ED and PD of summer maize with optimized P management over 10 years were less than those of winter wheat regardless of using yield or nutrient level as the functional unit. However, the EP of the nutrient supply in winter wheat was less than that in summer maize under optimized P fertilization. The specific nutritional components that limited improvements in environment of wheat and maize production under the optimal P rate were energy (calories) and protein, respectively. In conclusion, in a multifunctional winter wheat-summer maize rotation system, optimized P fertilization (50 kg ha for winter wheat and 25 kg ha for summer maize) combined with the planting of high-yield wheat varieties and high-protein maize varieties showed great potential to reduce the environmental impacts of wheat and maize production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2021.147039DOI Listing
August 2021

Plant flavones enrich rhizosphere Oxalobacteraceae to improve maize performance under nitrogen deprivation.

Nat Plants 2021 04 8;7(4):481-499. Epub 2021 Apr 8.

College of Resources and Environment, and Academy of Agricultural Sciences, Southwest University, Chongqing, China.

Beneficial interactions between plant roots and rhizosphere microorganisms are pivotal for plant fitness. Nevertheless, the molecular mechanisms controlling the feedback between root architecture and microbial community structure remain elusive in maize. Here, we demonstrate that transcriptomic gradients along the longitudinal root axis associate with specific shifts in rhizosphere microbial diversity. Moreover, we have established that root-derived flavones predominantly promote the enrichment of bacteria of the taxa Oxalobacteraceae in the rhizosphere, which in turn promote maize growth and nitrogen acquisition. Genetic experiments demonstrate that LRT1-mediated lateral root development coordinates the interactions of the root system with flavone-dependent Oxalobacteraceae under nitrogen deprivation. In summary, these experiments reveal the genetic basis of the reciprocal interactions between root architecture and the composition and diversity of specific microbial taxa in the rhizosphere resulting in improved plant performance. These findings may open new avenues towards the breeding of high-yielding and nutrient-efficient crops by exploiting their interaction with beneficial soil microorganisms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41477-021-00897-yDOI Listing
April 2021

Report of Two Novel Thalassemia Variants, : c.181delG and : c.121_126delAAGACC, in Chinese Individuals.

Hemoglobin 2021 Jan 1;45(1):52-55. Epub 2021 Apr 1.

Central Laboratory, Hainan General Hospital, Hainan Hospital Affiliated to The Hainan Medical College, Hainan Provincial Key Laboratory of Cell and Molecular Genetic Translational Medicine, Haikou, Hainan Province, People's Republic of China.

In this study, we report two novel thalassemia variants detected in Chinese individuals using targeted NGS technology. We detected a novel frameshift variant, : c.181delG, in a 32-year-old Chinese individual. This novel variant [a single nucleotide deletion at nucleotide 181 of codon 60 (-G)], was detected by targeted next generation sequencing (NGS), resulting in a stop codon at codon 60 in exon 2 of the gene. The impact of this novel variant was further analyzed by an model. We also identified a novel in-frame variant, : c.121_126delAAGACC [codons 40/41 (-AAGACC)], in another Chinese individual in this study. We named these two novel variants, : c.181delG and : c.121_126delAAGACC according to the Human Genome Variation Society (HGVS), which were detected by the first author. These two novel variants have expanded the mutation spectrum of thalassemia and it would be beneficial for carrier screening, genetic counseling and prenatal diagnosis (PND) of thalassemia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/03630269.2021.1883646DOI Listing
January 2021

HIV-1LAI Nef blocks the development of hematopoietic stem/progenitor cells into T lymphoid cells.

AIDS 2021 05;35(6):851-860

Department of Clinical Medicine, Nanchang University, Nanchang, Jiangxi, China.

Objective: Despite successful antiviral therapy, the recovery of CD4+ T cells may not be complete in certain HIV-1-infected individuals. In our previous work with humanized mice infected with CXCR4-tropic HIV-1LAI (LAI), viral protein Nef was found the major factor determining rapid loss of both CD4+ T cells and CD4+CD8+ thymocytes but its effect on early T-cell development is unknown. The objective of this study is to investigate the influence of LAI Nef on the development of hematopoietic stem/progenitor cells (HSPCs) into T lymphoid cells.

Design: HSPC-OP9-DL1 cell co-culture and humanized mouse model was used to investigate the objective of our study in vitro and in vivo. RNA-seq was exploited to study the change of gene expression signature after nef expression in HSPCs.

Results: Nef expression in HSPCs was found to block their development into T lymphoid cells both in vitro and in the mice reconstituted with nef-expressing HSPCs derived from human cord blood. More surprisingly, in humanized mice nef expression preferentially suppressed the production of CD4+ T cells. This developmental defect was not the result of CD34+ cell loss. RNA-seq analysis revealed that Nef affected the expression of 176 genes in HSPCs, including those involved in tumor necrosis factor, Toll-like receptor, and nucleotide-binding oligomerization domain-like receptor signaling pathways that are important for hematopoietic cell development.

Conclusion: Our results demonstrate that Nef compromises the development of HSPCs into T lymphoid cells, especially CD4+ T cells. This observation suggests that therapeutics targeting Nef may correct HIV-1-associated hematopoietic abnormalities, especially defects in T-cell development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/QAD.0000000000002837DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8048728PMC
May 2021

Soil Microbial Composition and Gene Abundance Are Sensitive to Phosphorus Level in a Long-Term Wheat-Maize Crop System.

Front Microbiol 2020 14;11:605955. Epub 2021 Jan 14.

College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, China.

Microbes associated with phosphorus (P) cycling are intrinsic to soil P transformation and availability for plant use but are also influenced by the application of P fertilizer. Nevertheless, the variability in soil P in the field means that integrative analyses of soil P cycling, microbial composition, and microbial functional genes related to P cycling remain very challenging. In the present study in the North China Plain, we subjected the bacterial and fungal communities to amplicon sequencing analysis and characterized the alkaline phosphatase ( encoding bacterial alkaline phosphatase in a long-term field experiment (10 years) with six mineral P fertilization rates up to 200 kg P ha. Long-term P fertilization increased soil available P, inorganic P, and total P, while soil organic P increased until the applied P rate reached 25 kg ha and then decreased. The fungal alpha-diversity decreased as P rate increased, while there were no significant effects on bacterial alpha-diversity. Community compositions of bacteria and fungi were significantly affected by P rates at order and family levels. The number of keystone taxa decreased from 10 to 3 OTUs under increasing P rates from 0 to 200 kg ha. The gene copy numbers of the biomarker of the alkaline phosphatase was higher at moderate P rates (25 and 50 kg ha) than at low (0 and 12.5 kg ha) and high (100 and 200 kg ha) rates of P fertilization, and was positively correlated with soil organic P concentration. One of the keystone taxa named BacOTU3771 belonging to Xanthomonadales was positively correlated with potential functional genes encoding enzymes such as glycerophosphoryl diester phosphodiesterase, acid phosphatase and negatively correlated with guinoprotein glucose dehydrogenase. Altogether, the results show the systematic effect of P gradient fertilization on P forms, the microbial community structure, keystone taxa, and functional genes associated with P cycling and highlight the potential of moderate rates of P fertilization to maintain microbial community composition, specific taxa, and levels of functional genes to achieve and sustain soil health.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2020.605955DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7873961PMC
January 2021

Carbon footprint of maize production in tropical/subtropical region: a case study of Southwest China.

Environ Sci Pollut Res Int 2021 Jun 5;28(22):28680-28691. Epub 2021 Feb 5.

Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Chongqing, 400715, China.

Maize production is critical in tropical/subtropical regions, especially in developing countries where maize is a staple food. However, its environmental costs remain unclear. Southwest China is a tropical/subtropical region with large-scale maize production in each of its sub-regions. In the present study, we used Southwest China as a case study to evaluate the greenhouse gas (GHG) emissions and carbon footprint (CF) of maize production during 1996-2015 using life cycle assessment to identify the driving factors behind the GHG emissions and CF and to propose potential mitigation strategies. The mean GHG emissions of maize production per year during 1996-2015 was 4132 kg CO-eq·ha, and the CF during this period was 961 kg CO-eq·Mg. The GHG emissions and CF in Southwest China were 2-4 times higher than those of other major maize-producing regions worldwide. The GHG emissions and CF were both significantly correlated with the N surplus. The N surplus was also linearly correlated with annual precipitation, annual temperature and growing degree days, but not significantly related with soil pH. Scenario testing showed that the CF of maize production in Southwest China could be reduced by 41%, i.e. to 437 kg CO-eq·Mg, by farmers adopting a comprehensive strategy including recommended fertiliser application rates, innovative fertilisers, and crop management to decrease GHG emissions and achieve the yield potential in the region. Integrated soil and crop management is essential for sustainable maize production in tropical/subtropical regions with complex and changeable ecological conditions, especially in developing countries where maize is a staple food.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-021-12663-wDOI Listing
June 2021

Combined applications of organic and synthetic nitrogen fertilizers for improving crop yield and reducing reactive nitrogen losses from China's vegetable systems: A meta-analysis.

Environ Pollut 2021 Jan 23;269:116143. Epub 2020 Nov 23.

College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, 400716, China; Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, Southwest University, Chongqing, 400716, China; Chongqing Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Southwest University, Chongqing, 400716, China. Electronic address:

The combined application of organic and synthetic nitrogen (N) fertilizers is being widely recommended in China's vegetable systems to reduce reliance on synthetic N fertilizer. However, the effect of substituting synthetic fertilizer with organic fertilizer on vegetable productivity (yield, N uptake and nitrogen use efficiency) and reactive nitrogen (Nr) losses (NO emission, N leaching and NH volatilization) remains unclear. A meta-analysis was performed using peer-reviewed papers published from 2000 to 2019 to comprehensively assess the effects of combined application of organic and synthetic N fertilizers. The results indicate that overall, the vegetable yield, NO emission and NH volatilization were not significantly changed, whereas N leaching was reduced by 44.6% and soil organic carbon (SOC) concentration increased by 12.5% compared to synthetic N fertilizer alone. Specifically, when synthetic N substitution rates (SRs) were ≤70%, vegetable yields and SOC concentration were increased by 5.5%-5.6% and 13.1-18.0%, and N leaching was reduced by 41.6%-48.1%. At the high substitution rate (SR>70%), vegetable yield was reduced by 13.6%, NO emission was reduced by 14.3%, and SOC concentration increased by 16.4%. Mixed animal-plant sources of organic N preferentially increased vegetable yield and SOC concentration, and reduced NO emission and N leaching compared with single sources of organic-N. Greenhouse gas (GHG) emission was decreased by 28.4%-34.9% by combined applications of organic and synthetic N sources, relative to synthetic N fertilizer alone. We conclude that appropriate rates (SR ≤ 70%) of combined applications of organic and synthetic N fertilizers could improve vegetable yields, decrease Nr and GHG emission, and facilitate sustainable development of coupled vegetable-livestock systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2020.116143DOI Listing
January 2021

Phosphorus fractionation related to environmental risks resulting from intensive vegetable cropping and fertilization in a subtropical region.

Environ Pollut 2021 Jan 20;269:116098. Epub 2020 Nov 20.

College of Resources and Environment, Academy of Agricultural Sciences, Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Southwest University, Chongqing, 400716, PR China. Electronic address:

Overuse of phosphorus (P) fertilizer and the resulting soil P accumulation in vegetable production increases the risk of P runoff and leaching. However, P transformations under continuous fertilization and their effects on environmental risk are unclear. The current study examined the effects of long-term P fertilizer application on P fractions in different soil layers, and assessed the correlations between P fractions and environmental risks in intensive vegetable production in a subtropical region. A total of 32 fields were studied, including 8 uncultivated fields and 24 fields continuously used for vegetable production for 1-3, 4-9, or 10-15 years. The results showed that excessive P fertilizer input caused soil P surpluses ranging from 204.6 to 252.4 kg ha yr. Compared to uncultivated fields, vegetable fields contained higher levels of labile P, moderately labile P, sparingly labile P, and non-labile P. The combined percentage of labile P and moderately labile P increased from 55.2% in fields cultivated for 0-3 year to 65.5% in fields cultivated for 10-15 years. The concentrations of soil P fractions were higher at 0-20 cm soil depth than at 20-40 and 40-60 cm soil depth. Soil available P was positively correlated with all soil P fractions except diluted HCl-P or concentrated HCl-P. Long-term vegetable production increased CaCl-P downward movement, which was positively correlated with levels of labile and moderately labile P. The P index indicated a high risk of P losses from the vegetable fields. The P index was on average 3.27-fold higher in the vegetable fields than in uncultivated fields, and was significantly correlated with soil available P and organic and inorganic P fertilizer input. The environmental risk caused by P in vegetable production should be reduced by reducing P fertilizer input so as to maintain soil available P within an optimal range for vegetable production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2020.116098DOI Listing
January 2021

Identification of an IRF10 gene in common carp (Cyprinus carpio L.) and analysis of its function in the antiviral and antibacterial immune response.

BMC Vet Res 2020 Nov 19;16(1):450. Epub 2020 Nov 19.

Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, No. 88 East Wenhua Road, Jinan, 250014, China.

Background: Interferon (IFN) regulatory factors (IRFs), as transcriptional regulatory factors, play important roles in regulating the expression of type I IFN and IFN- stimulated genes (ISGs) in innate immune responses. In addition, they participate in cell growth and development and regulate oncogenesis.

Results: In the present study, the cDNA sequence of IRF10 in common carp (Cyprinus carpio L.) was characterized (abbreviation, CcIRF10). The predicted protein sequence of CcIRF10 shared 52.7-89.2% identity with other teleost IRF10s and contained a DNA-binding domain (DBD), a nuclear localization signal (NLS) and an IRF-associated domain (IAD). Phylogenetic analysis showed that CcIRF10 had the closest relationship with IRF10 of Ctenopharyngodon idella. CcIRF10 transcripts were detectable in all examined tissues, with the highest expression in the gonad and the lowest expression in the head kidney. CcIRF10 expression was upregulated in the spleen, head kidney, foregut and hindgut upon polyinosinic:polycytidylic acid (poly I:C) and Aeromonas hydrophila stimulation and induced by poly I:C, lipopolysaccharide (LPS) and peptidoglycan (PGN) in peripheral blood leucocytes (PBLs) and head kidney leukocytes (HKLs) of C. carpio. In addition, overexpression of CcIRF10 was able to decrease the expression of the IFN and IFN-stimulated genes PKR and ISG15.

Conclusions: These results indicate that CcIRF10 participates in antiviral and antibacterial immunity and negatively regulates the IFN response, which provides new insights into the IFN system of C. carpio.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-020-02674-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7678311PMC
November 2020

Mechanistic Phase II Clinical Trial of Metformin in Pulmonary Arterial Hypertension.

J Am Heart Assoc 2020 11 10;9(22):e018349. Epub 2020 Nov 10.

Division of Allergy, Pulmonary and Critical Care Medicine Vanderbilt University Medical Center Nashville TN.

Background Metabolic dysfunction is highly prevalent in pulmonary arterial hypertension (PAH) and likely contributes to both pulmonary vascular disease and right ventricular (RV) failure in part because of increased oxidant stress. Currently, there is no cure for PAH and human studies of metabolic interventions, generally well tolerated in other diseases, are limited in PAH. Metformin is a commonly used oral antidiabetic that decreases gluconeogenesis, increases fatty acid oxidation, and reduces oxidant stress and thus may be relevant to PAH. Methods and Results We performed a single-center, open-label 8-week phase II trial of up to 2 g/day of metformin in patients with idiopathic or heritable PAH with the co-primary end points of safety, including development of lactic acidosis and study withdrawal, and plasma oxidant stress markers. Exploratory end points included RV function via echocardiography, plasma metabolomic analysis performed before and after metformin therapy, and RV triglyceride content by magnetic resonance spectroscopy in a subset of 9 patients. We enrolled 20 patients; 19/20 reached the target dose and all completed the study protocol. There was no clinically significant lactic acidosis or change in oxidant stress markers. Metformin did not change 6-minute walk distance but did significantly improve RV fractional area change (23±8% to 26±6%, =0.02), though other echocardiographic parameters were unchanged. RV triglyceride content decreased in 8/9 patients (3.2±1.8% to 1.6±1.4%, =0.015). In an exploratory metabolomic analysis, plasma metabolomic correlates of ≥50% reduction in RV lipid included dihydroxybutyrate, acetylputrescine, hydroxystearate, and glucuronate (<0.05 for all). In the entire cohort, lipid metabolites were among the most changed by metformin. Conclusions Metformin therapy was safe and well tolerated in patients with PAH in this single-arm, open-label phase II study. Exploratory analyses suggest that metformin may be associated with improved RV fractional area change and, in a subset of patients, reduced RV triglyceride content that correlated with altered lipid and glucose metabolism markers. Registration URL: http://www.clinicaltrials.gov; Unique identifier: NCT01884051.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/JAHA.120.018349DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7763730PMC
November 2020

Global direct nitrous oxide emissions from the bioenergy crop sugarcane (Saccharum spp. inter-specific hybrids).

Sci Total Environ 2021 Jan 20;752:141795. Epub 2020 Aug 20.

Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing 400716, China; Center for Resources, Environment and Food Security, China Agricultural University, Beijing 100193, China. Electronic address:

Sugarcane is the second largest bioenergy crop in the world and it accounts for 80% of global sugar production. Grown mostly in wet and warm tropics with relatively high nitrogen (N) fertiliser input and crop residue retention, sugarcane production is a significant source of nitrous oxide (NO) emission. Yet, a global evaluation of research on NO emission from sugarcane crop is lacking. Here, we conducted a meta-analysis using data from 141 measurements compiled from 15 sugarcane field studies reported from different countries to i) quantify NO emissions and emission factors (EFs) globally, and for tropics and sub-tropics, and ii) identify the key factors that promote NO emission. Our analysis shows that the global mean total NO emission from sugarcane production reached 2.26 (CI: 1.93-2.62) kg NO-N ha yr with an estimated EF of 1.21% (CI: 0.971-1.46%). NO emissions increased exponentially with increase in N fertiliser rate, questioning the adequacy of Intergovernmental Panel on Climate Change (IPCC) default EF value (1%) for sugarcane NO emission estimation. Mean total NO emissions and EFs in tropics and sub-tropics did not vary significantly. Supplementing synthetic N fertiliser (SN) with organic amendments (OA) significantly increased mean NO emission (~1.4-fold) and EF (~2.5-fold) compared to SN. A remarkable reduction in NO emission (38.6%) and EF (61.5%) was evident when enhanced efficiency fertilisers (EEF) replaced SN. In contrast, crop residue removal had little impact on NO emission and EF, but both parameters showed an upward trend with irrigation and increased rainfall. Soil carbon content and pH were emerged as key regulators of sugarcane NO emission and EF. It is concluded that global sugarcane NO emission could be significant and that there is considerable prospect for mitigating the emission through innovative nutrient formulations and precision agriculture that help meet crop nutrient demand without compromising environmental imperatives.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2020.141795DOI Listing
January 2021

Modeling the Contribution of Crops to Nitrogen Pollution in the Yangtze River.

Environ Sci Technol 2020 10 11;54(19):11929-11939. Epub 2020 Sep 11.

College of Resources and Environment, Southwest University, Tiansheng Road 02, Chongqing 400715, China.

Agriculture contributes considerably to nitrogen (N) inputs to the world's rivers. In this study, we aim to improve our understanding of the contribution of different crops to N inputs to rivers. To this end, we developed a new model system by linking the MARINA 2.0 (Model to Assess River Input of Nutrient to seAs) and WOFOST (WOrld FOod STudy) models. We applied this linked model system to the Yangtze as an illustrative example. The N inputs to crops in the Yangtze River basin showed large spatial variability. Our results indicate that approximately 6,000 Gg of N entered all rivers of the Yangtze basin from crop production as dissolved inorganic N (DIN) in 2012. Half of this amount is from the production of single rice, wheat, and vegetables, where synthetic fertilizers were largely applied. In general, animal manure contributes 12% to total DIN inputs to rivers. Three-quarters of manure-related DIN in rivers are from vegetable, fruit, and potato production. The contributions of crops to river pollution differ among sub-basins. For example, potato is an important source of DIN in rivers of some upstream sub-basins. Our results may help to prioritize the dominant crop sources for management to mitigate N pollution in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.est.0c01333DOI Listing
October 2020

Nutritional quality and health risk of pepper fruit as affected by magnesium fertilization.

J Sci Food Agric 2021 Jan 7;101(2):582-592. Epub 2020 Aug 7.

College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, China.

Background: Magnesium (Mg) fertilization is a promising practice to improve vegetable yield. However, its impacts on vegetable quality and human health have not been examined. Thus, a field experiment was conducted to investigate the effects of varying Mg fertilization rates on yield and quality of pepper (Capsicum annuum L.) fruit. Furthermore, result of the field experiment was linked to pepper consumption data from the China Health and Nutrition Survey (CHNS) in the disability-adjusted life years (DALYs) framework to evaluate the potential health impact of Mg fertilization for the first time.

Results: Compared to control, Mg fertilization increased the 2-year average pepper yield by 25.6%, whereas there was no significant yield improvement when Mg rates exceeded 112.5 kg MgO ha . Magnesium application increased concentrations of Mg and capsaicinoids, decreased those of calcium (Ca), zinc (Zn) and vitamin C (Vc), and had no effect on potassium (K) and iron (Fe) in pepper fruit. As a result, Mg fertilization decreased the comprehensive nutrition level of pepper by 16.6%. Furthermore, the current health burden of the Chinese adult population associated with pepper consumption is estimated at 21.3 million DALYs per year, with the risk being increased by 5.40 DALYs for per megagram of Mg fertilizer application. Increasing health risk was mainly attributed to decreasing concentrations of Ca and Vc in pepper fruit, though the increased Mg intakes offset the impact of 1.74% to 14.4%.

Conclusion: Magnesium fertilization significantly improved the yield but reduced nutritional quality of pepper fruit, and increased human health risks associated with consumption of pepper fruit. © 2020 Society of Chemical Industry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jsfa.10670DOI Listing
January 2021

Integrated systematic approach increase greenhouse tomato yield and reduce environmental losses.

J Environ Manage 2020 Jul 16;266:110569. Epub 2020 Apr 16.

College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, 400716, China; Chongqing Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Southwest University, Chongqing, 400716, China. Electronic address:

High input - high output greenhouse vegetable systems are responsible for nutrient surpluses and environmental losses. Integrated strategies that improve soil, crop and nutrient management are needed to ensure more sustainable production systems. We conducted a two-year field experiment to evaluate the potential of integrated soil-crop system management (ISSM) practices to improve the productivity and environmental outcomes from an intensive greenhouse tomato production system in the Yangtze River Basin, China. Four treatments were tested: i) farmers' practice (FP); ii) soil remediation (SR), where lime nitrogen with compost addition was the only management strategy; iii) a treatment that combined soil remediation with optimized crop planting density (SRCO), which increased planting density for improving crop yield; and iv) integrated soil-crop system management (ISSM), as a systematic integrated approach, which included the combined optimization of soil remediation, crop optimization, and nutrient management. In the integrated soil-crop system management treatment, nutrient management was optimized through adoption of the most appropriate type (formula) of fertilizer for the crop, rate and application timing of synthetic fertilizer, and by substituting poultry manure with compost. Our results indicated that the fruit yield of the integrated soil-crop system management treatment was 104 t ha, 13.4%-37.3% higher than that of the other three treatments. The mean reactive nitrogen loss (81.1 kg N ha) and the greenhouse gas emissions (6495 kg CO-eq ha) in the farmers' practice treatment were much higher than in the other three treatments (reactive nitrogen loss: 47.9-54.3 kg N ha; and greenhouse gas emissions: 4926-5468 kg CO-eq ha, respectively). The mean nitrogen and carbon footprints of the integrated soil-crop system management treatment were significantly lower than those of other treatments, as a result of both the lower fertilizer nitrogen use and the greater yield. This study indicates that integrated soil-crop system management could produce greater yields and increase net profit with reduced nitrogen inputs, whilst reducing the environmental cost associated with conventional farmers' practice in plastic-greenhouse vegetable production systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jenvman.2020.110569DOI Listing
July 2020

Substitution of manure for chemical fertilizer affects soil microbial community diversity, structure and function in greenhouse vegetable production systems.

PLoS One 2020 21;15(2):e0214041. Epub 2020 Feb 21.

Laboratory of Geo-information Science and Remote Sensing, Wageningen University, Wageningen, The Netherlands.

Soil microbial communities and enzyme activities together affect various ecosystem functions of soils. Fertilization, an important agricultural management practice, is known to modify soil microbial characteristics; however, inconsistent results have been reported. The aim of this research was to make a comparative study of the effects of different nitrogen (N) fertilizer rates and types (organic and inorganic) on soil physicochemical properties, enzyme activities and microbial attributes in a greenhouse vegetable production (GVP) system of Tianjin, China. Results showed that manure substitution of chemical fertilizer, especially at a higher substitution rate, improved soil physicochemical properties (higher soil organic C (SOC) and nutrient (available N and P) contents; lower bulk densities), promoted microbial growth (higher total phospholipid fatty acids and microbial biomass C contents) and activity (higher soil hydrolase activities). Manure application induced a higher fungi/bacteria ratio due to a lower response in bacterial than fungal growth. Also, manure application greatly increased bacterial stress indices, as well as microbial communities and functional diversity. The principal component analysis showed that the impact of manure on microbial communities and enzyme activities were more significant than those of chemical fertilizer. Furthermore, redundancy analysis indicated that SOC and total N strongly influenced the microbial composition, while SOC and ammonium-N strongly influenced the microbial activity. In conclusion, manure substitution of inorganic fertilizer, especially at a higher substitution rate, was more efficient for improving soil quality and biological functions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214041PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7034837PMC
April 2020

dysfunction impairs insulin signaling and glucose homeostasis in cardiomyocytes.

Am J Physiol Lung Cell Mol Physiol 2020 02 18;318(2):L429-L441. Epub 2019 Dec 18.

Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee.

Insulin resistance and right ventricular (RV) dysfunction are associated with lipotoxicity in heritable forms of pulmonary arterial hypertension (PAH), commonly due to mutations in bone morphogenetic protein receptor type 2 (BMPR2). How BMPR2 dysfunction in cardiomyocytes alters glucose metabolism and the response of these cells to insulin are unknown. We hypothesized that BMPR2 mutation in cardiomyocytes alters glucose-supported mitochondrial respiration and impairs cellular responses to insulin, including glucose and lipid uptake. We performed metabolic assays, immunofluorescence and Western analysis, RNA profiling, and radioactive isotope uptake studies in H9c2 cardiomyocyte cell lines with and without patient-derived BMPR2 mutations (mutant cells), with and without insulin. Unlike control cells, BMPR2 mutant cardiomyocytes have reduced metabolic plasticity as indicated by reduced mitochondrial respiration with increased mitochondrial superoxide production. These mutant cells show enhanced baseline phosphorylation of insulin-signaling protein as indicated by increased Akt, AMPK, and acetyl-CoA carboxylase phosphorylation that may negatively influence fatty acid oxidation and enhance lipid uptake, and are insulin insensitive. Furthermore, mutant cells demonstrate an increase in milk fat globule-EGF factor-8 protein (MFGE8), which influences the insulin-signaling pathway by phosphorylating Akt via phosphatidylinositol 3-kinase and mammalian target of rapamycin. In conclusion, BMPR2 mutant cardiomyocytes have reduced metabolic plasticity and fail to respond to glucose. These cells have enhanced baseline insulin-signaling pattern favoring insulin resistance with failure to augment this pattern in response to insulin. BMPR2 mutation possibly blunts glucose uptake and enhances lipid uptake in these cardiomyocytes. The MFGE8-driven signaling pathway may suggest a new mechanism underlying RV lipotoxicity in PAH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajplung.00555.2018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7052666PMC
February 2020

The anti-aging effects of Gracilaria lemaneiformis polysaccharide in Caenorhabditis elegans.

Int J Biol Macromol 2019 Nov 22;140:600-604. Epub 2019 Aug 22.

Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo 315211, China. Electronic address:

The anti-aging activity of marine macroalgae Gracilaria lemaneiformis polysaccharide (GP) on Caenorhabditis elegans was evaluated by observing the lifespan, reproduction, pharyngeal pumping and stress response of worms. Moreover, quantitative fluorescence of polyglutamic acid and nuclear localization of DAF-16 were observed. The results showed that GP treatment enhanced the mean lifespan by over 16.47% and significantly increased the reproduction duration of worm in the high dose group (1000 μg/mL). GP exhibited little potent effects under the thermotolerance and oxidative stress. The number of polyglutamic acid aggregates in three dosage groups decreased by 24.82%, 32.08% and 30.93% (p < 0.05) compared to the control. The middle dose group strongly induced DAF-16 nuclear translocation over intermediate and cytosolic localizations compared to the control (p < 0.001). It was inferred that GP extended the adult lifespan of wild-type and polyQ nematodes through the insulin pathway DAF-16.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijbiomac.2019.08.186DOI Listing
November 2019

Overexpression of miR-148a inhibits viability and invasion of ovarian cancer OVCAR3 cells by targeting FOXO3.

Oncol Lett 2019 Jul 6;18(1):402-410. Epub 2019 May 6.

Department of Obstetrics and Gynecology, Taizhou People's Hospital, Fifth Affiliated Hospital to Nantong University, Taizhou, Jiangsu 225300, P.R. China.

Decreased expression of microRNA (miR)-148a is associated with poor prognosis in ovarian cancer. The aim of the present study was to investigate the impact of miR-148a on tumor cell viability and invasion via targeting forkhead box protein O3 (FOXO3). Expression of miR-148a was detected in paired tumor and adjacent normal tissues. OVCAR3 cells were transfected with miR-148a mimic and inhibitor. Cell viability, apoptosis and invasion were determined. A luciferase reporter assay was used to study the association between miR-148a and FOXO3. In addition, the influence of miR-148a on tumor cell growth was investigated by performing xenograft assays in nude mice. RT-qPCR showed that miR-148a was downregulated in ovarian cancer tissues. Overexpression of miR-148a in OVCAR3 cells inhibited cell viability, suppressed invasion and promoted cellular apoptosis. The dual-luciferase assay indicated that miR-148a directly regulated the expression of FOXO3, a transcription factor of caspase-3. Western blotting confirmed that the expression of caspase-3 was regulated by the modulation of miR-148a expression. assays revealed that miR-148a overexpression inhibited the growth of OVCAR3 ×enograft tumors in nude mice. miR-148a is a tumor suppressor in ovarian cancer OVCAR3 cells and in nude mice. The suppressive effect is due to inhibiting cell viability and invasion as well as promoting apoptosis. These results may provide theoretical basis for targeting miR-148a in the treatment of ovarian cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/ol.2019.10321DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6539956PMC
July 2019

Preparation and Identification of ACE Inhibitory Peptides from the Marine Macroalga .

Mar Drugs 2019 Mar 19;17(3). Epub 2019 Mar 19.

School of Marine Sciences, Ningbo University, Ningbo 315211, China.

Angiotensin I-converting enzyme (ACE) inhibitory peptides derived from seaweed represent a potential source of new antihypertensive. The aim of this study was to isolate and purify ACE inhibitory peptides (ACEIPs) from the protein hydrolysate of the marine macroalga . protein was hydrolyzed by five different proteases (trypsin, pepsin, papain, α-chymotrypsin, alcalase) to prepare peptides; compared with other hydrolysates, the trypsin hydrolysates exhibited the highest ACE inhibitory activity. The hydrolysis conditions were further optimized by response surface methodology (RSM), and the optimum conditions were as follows: pH 8.4, temperature 28.5 °C, enzyme/protein ratio (E/S) 4.0%, substrate concentration 15 mg/mL, and enzymolysis time 5.0 h. After fractionation and purification by ultrafiltration, gel exclusion chromatography and reverse-phase high-performance liquid chromatography, two novel purified ACE inhibitors with IC values of 219.35 μM (0.183 mg/mL) and 236.85 μM (0.179 mg/mL) were obtained. The molecular mass and amino acid sequence of the ACE inhibitory peptides were identified as Phe-Gly-Met-Pro-Leu-Asp-Arg (FGMPLDR; MW 834.41 Da) and Met-Glu-Leu-Val-Leu-Arg (MELVLR; MW 759.43 Da) by ultra-performance liquid chromatography-tandem mass spectrometry. A molecular docking study revealed that the ACE inhibitory activities of the peptides were mainly attributable to the hydrogen bond and Zn(II) interactions between the peptides and ACE. The results of this study provide a theoretical basis for the high-valued application of and the development of food-derived ACE inhibitory peptides.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/md17030179DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6471128PMC
March 2019

Severe hemolytic anemia due to combined α thalassemia and de novo Hemoglobin Sabine.

Ann Hematol 2019 Mar 23;98(3):783-785. Epub 2019 Jan 23.

Department of Central Laboratory, Key Laboratory of Cellular and Molecular Genetic Transformation of Hainan Province Medicine, Hainan Province People's Hospital, Haikou, 570311, Hainan Province, China.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00277-019-03617-xDOI Listing
March 2019

The effects of controlled release urea on maize productivity and reactive nitrogen losses: A meta-analysis.

Environ Pollut 2019 Mar 23;246:559-565. Epub 2018 Dec 23.

College of Resources and Environment, Academy of Agricultural Science, Southwest University, Chongqing, 400716, PR China. Electronic address:

Application of controlled release urea (CRU) is recommended to reduce the undesirable environmental effects resulting from urea application. However, the overall effects of CRU on maize productivity and reactive nitrogen (N) losses remain unclear. Our global meta-analysis based on 866 observations of 120 studies indicated that application of CRU instead of urea (same N rate) increased maize yield by 5.3% and nitrogen use efficiency (NUE) by 24.1%, and significantly decreased nitrous oxide (NO) emission, N leaching and ammonia (NH) volatilization by 23.8%, 27.1% and 39.4%, respectively. The increase of NUE and reduction of NO emission by CRU application were greater with medium and high N rates (150 ≤ N < 200 and N ≥ 200 kg N ha) than with low N rates. The reduction in NO emission and N leaching with CRU application were enhanced when soil organic carbon (SOC) content was <15.0 g kg, and soil texture was medium or coarse. The reduction in NO emission and NH volatilization with CRU were greater in soils with pH ≥ 6.0. We concluded that use of CRU should be encouraged for maize production, especially on light-textured soils with low organic matter content.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2018.12.059DOI Listing
March 2019

Nitrous Oxide Emissions Increase Exponentially When Optimum Nitrogen Fertilizer Rates Are Exceeded in the North China Plain.

Environ Sci Technol 2018 11 26;52(21):12504-12513. Epub 2018 Oct 26.

SRUC , West Mains Road , Edinburgh, EH9 3JG , Scotland , U.K.

The IPCC assume a linear relationship between nitrogen (N) application rate and nitrous oxide (NO) emissions in inventory reporting, however, a growing number of studies show a nonlinear relationship under specific soil-climatic conditions. In the North China plain, a global hotspot of NO emissions, covering a land as large as Germany, the correlation between N rate and NO emissions remains unclear. We have therefore specifically investigated the NO response to N applications by conducting field experiments with five N rates, and high-frequency measurements of NO emissions across contrasting climatic years. Our results showed that cumulative and yield-scaled NO emissions both increased exponentially as N applications were raised above the optimum rate in maize ( Zea mays L.). In wheat ( Triticum aestivum L.) there was a corresponding quadratic increase in NO emissions with the magnitude of the response in 2012-2013 distinctly larger than that in 2013-2014 owing to the effects of extreme snowfall. Existing empirical models (including the IPCC approach) of the NO response to N rate have overestimated NO emissions in the North China plain, even at high N rates. Our study therefore provides a new and robust analysis of the effects of fertilizer rate and climatic conditions on NO emissions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.est.8b03931DOI Listing
November 2018

Nitrate leaching from open-field and greenhouse vegetable systems in China: a meta-analysis.

Environ Sci Pollut Res Int 2018 Nov 4;25(31):31007-31016. Epub 2018 Sep 4.

College of Resources and Environment, Southwest University, Chongqing, 400716, China.

The potential for nitrate leaching in Chinese vegetable systems is substantial because of high inputs of nitrogen (N) fertilizer and water. To quantify the nitrate leaching and identify the key controlling factors in Chinese vegetable systems, we conducted a meta-analysis that included 221 data sets from 18 field studies. The results revealed that nitrate leaching over the entire crop growing season in Chinese vegetable systems was very high and averaged 79.1 kg N ha and primarily resulted from extremely high N fertilizer inputs (in average 423 kg N ha). Nitrate leaching was, on the average, 63.9% greater in the greenhouse systems (98.0 kg N ha) than in open-field systems (59.8 kg N ha). The leaching factor, defined as the proportion of the quantity of N applied to soils that was lost due to nitrate leaching, averaged 14.6% overall and was significantly lower in greenhouse systems (10.9%) than in open-field systems (18.4%). This difference appears to be due to lower of the total water inputs (irrigation + precipitation) in greenhouse systems. Nitrate leaching increased with water input, the number of growing days, and the N rate. The nitrate leaching response to increasing N rate was linear. The leaching factor significantly increased with water input but was not affected by the N rate or the number of growing days. Compared with application of synthetic fertilizer alone, the application of manure alone or manure plus synthetic fertilizer significantly reduced both the nitrate leaching and the leaching factor in open-field and greenhouse systems. These results suggest that nitrate leaching in Chinese vegetable systems can be reduced by optimizing rates of N and water supply to synchronize crop needs. Application of mixed synthetic N fertilizer and manure is more effective in reducing nitrate leaching, compared to synthetic N only.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-018-3082-zDOI Listing
November 2018

A potential therapeutic role for angiotensin-converting enzyme 2 in human pulmonary arterial hypertension.

Eur Respir J 2018 06 21;51(6). Epub 2018 Jun 21.

Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.

Pulmonary arterial hypertension (PAH) is a deadly disease with no cure. Alternate conversion of angiotensin II (AngII) to angiotensin-(1-7) (Ang-(1-7)) by angiotensin-converting enzyme 2 (ACE2) resulting in Mas receptor (Mas1) activation improves rodent models of PAH. Effects of recombinant human (rh) ACE2 in human PAH are unknown. Our objective was to determine the effects of rhACE2 in PAH.We defined the molecular effects of Mas1 activation using porcine pulmonary arteries, measured AngII/Ang-(1-7) levels in human PAH and conducted a phase IIa, open-label pilot study of a single infusion of rhACE2 (GSK2586881, 0.2 or 0.4 mg·kg intravenously).Superoxide dismutase 2 (SOD2) and inflammatory gene expression were identified as markers of Mas1 activation. After confirming reduced plasma ACE2 activity in human PAH, five patients were enrolled in the trial. GSK2586881 was well tolerated with significant improvement in cardiac output and pulmonary vascular resistance. GSK2586881 infusion was associated with reduced plasma markers of inflammation within 2-4 h and increased SOD2 plasma protein at 2 weeks.PAH is characterised by reduced ACE2 activity. Augmentation of ACE2 in a pilot study was well tolerated, associated with improved pulmonary haemodynamics and reduced markers of oxidant and inflammatory mediators. Targeting this pathway may be beneficial in human PAH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1183/13993003.02638-2017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6613216PMC
June 2018

Meta-analysis data quantifying nitrous oxides emissions from Chinese vegetable production.

Data Brief 2018 Aug 11;19:114-116. Epub 2018 May 11.

Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China.

This paper describes data of nitrous oxides (NO) emissions from open-field and greenhouse systems in Chinese vegetable production. The data also describes the potential soil and management factors to identify the effective measures to mitigate NO emissions. The data were collected from 21 peer-reviewed papers, covering 153 NO emission field measurements as affected by fertilizer nitrogen (N) management. This data were subjected to meta-analysis for a comprehensive assessment on NO emission and applied N based emission factor in Chinese vegetable production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2018.05.034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5993008PMC
August 2018
-->