CR Dhan 310(CRD310),a biofortified rice variety,contains a significantly higher level of grain protein compared with its recurrent parent Naveen(NV),as well as most adapted high-yielding rice varieties in India.Althou...CR Dhan 310(CRD310),a biofortified rice variety,contains a significantly higher level of grain protein compared with its recurrent parent Naveen(NV),as well as most adapted high-yielding rice varieties in India.Although a limited investigation depicted that CRD310 contained higher levels of glutelin and some essential amino acids,detailed biochemical,molecular,and cellular mechanisms remain to be studied.As one of the means to identify the proteins and understand the underlying mechanism of higher proteins accumulation in grains of CRD310,the comparative proteomics was undertaken on grains of CRD310 and NV at the yellow ripening stage.展开更多
This study examined four species of Scylla genus(S.paramamosain,S.olivacea,S.serrata,and S.tranquebarica)morphologically and molecularly.Morphologically,distinct frontal lobe spine shapes and colorations were observed...This study examined four species of Scylla genus(S.paramamosain,S.olivacea,S.serrata,and S.tranquebarica)morphologically and molecularly.Morphologically,distinct frontal lobe spine shapes and colorations were observed.Using HRM genotyping with CSN9 primers,we identified clear species-specific melting curve distinctions.The Tm values of S.serrata,S.paramamosain,S.tranquebarica and S.olivacea are 79.55℃,80.12℃,78.12℃ and 82.04℃,respectively.Sequencing data validated these results,revealing 28 SNPs and 9 haplotypes.Amino acid analysis showed arginine dominance in S.paramamosain,which was 40.64 mg g^(-1),and a TFAA range of 135.70-149.65 mg g^(-1).A total of 26 fatty acids were identified,while S.paramamosain showed the highest concentration(P<0.05).EPA was a major component(16.17%-23.26%),while S.paramamosain exhibited the highest levels.Principal component analysis and cluster analysis highlighted distinct species groupings based on amino acid and fatty acid profiles.These findings provide comprehensive insights into Scylla species'morphological,molecular,and biochemical diversities.展开更多
Sesame is one of the eight major allergens that cause food allergies.Study of the epitopes of sesame allergens is important for understanding their sensitization mechanisms.Currently,less information is available on t...Sesame is one of the eight major allergens that cause food allergies.Study of the epitopes of sesame allergens is important for understanding their sensitization mechanisms.Currently,less information is available on the epitope studies of sesame allergens.In this study,we analyzed the molecular characteristics,structure and homology of Ses i 3,one of the important sesame allergens.We predicted the B-cell linear epitopes of Ses i 3 using bioinformatics tools and characterized them by slot blot immuno-microarrays technology.Eight peptides as B-cell linear epitopes of Ses i 3 were identified,in addition,key amino acids in these epitopes were predicted and leucine 422 was identified as a key amino acid.The present work will contribute to further understanding of the sesame allergen and provide some help in the prevention and treatment of sesame allergy.展开更多
Metabolic reprogramming involving branched-chain amino acids(BCAAs)—leucine,isoleucine,and valine—is increasingly recognized as pivotal in cancer progression,metastasis,and immune modulation.This review comprehensiv...Metabolic reprogramming involving branched-chain amino acids(BCAAs)—leucine,isoleucine,and valine—is increasingly recognized as pivotal in cancer progression,metastasis,and immune modulation.This review comprehensively explores how cancer cells rewire BCAA metabolism to enhance proliferation,survival,and therapy resistance.Tumors manipulate BCAA uptake and catabolism via high expression of transporters like L-type amino acid transporter 1(LAT1)and enzymes including branched chain amino acid transaminase 1(BCAT1),branched chain amino acid transaminase 2(BCAT2),branched-chain alpha-keto acid dehydrogenase(BCKDH),and branched chain alpha-keto acid dehydrogenase kinase(BCKDK).These alterations sustain energy production,biosynthesis,redox homeostasis,and oncogenic signaling(especially mammalian target of rapamycin complex 1[mTORC1]).Crucially,tumor-driven BCAA depletion also shapes an immunosuppressive microenvironment,impairing anti-tumor immunity by limiting essential nutrients for T cells and natural killer(NK)cells.Innovative therapeutic strategies targeting BCAA pathways—ranging from selective small-molecule inhibitors(e.g.,LAT1 and BCAT1/2)to dietary modulation—have shown promising preclinical and early clinical efficacy,highlighting their potential to exploit metabolic vulnerabilities in cancer cells while bolstering immune responses.By integrating multi-omics data and precision targeting approaches,this review underscores the translational significance of BCAA metabolic reprogramming,positioning it as a novel frontier in cancer treatment.展开更多
Skeletal muscle accounts for approximately 40%of body mass and 50%–75%of whole-body protein,playing a central role in meat production and quality.Efficient protein synthesis in skeletal muscle relies on an adequate s...Skeletal muscle accounts for approximately 40%of body mass and 50%–75%of whole-body protein,playing a central role in meat production and quality.Efficient protein synthesis in skeletal muscle relies on an adequate supply of nutrient substrates and a balanced amino acid profile.Branched-chain amino acids(BCAA),including leucine(Leu),isoleucine(Ile),and valine(Val),are the most abundant essential amino acids in skeletal muscle and contribute to both protein synthesis and oxidative energy production.Additionally,BCAA function as signaling molecules that regulate gene expression and protein phosphorylation cascades,which significantly influence physiological processes,such as protein synthesis and degradation,glucose and lipid metabolism,and cell apoptosis and autophagy.These processes are primarily mediated through the PI3K/AKT/AMPK/mTOR signaling pathways.This review summarizes BCAA transporters and catabolic metabolism,their role as signaling molecules in regulating protein metabolism and glucose and lipid equilibrium,and applications in animal production.These findings offer both theoretical insights and practical guidelines for the precise regulation of feed efficiency and production performance through tailored dietary BCAA supplementations.展开更多
The detection of amino acid enantiomers holds significant importance in biomedical,chemical,food,and other fields.Traditional chiral recognition methods using fluorescent probes primarily rely on fluorescence intensit...The detection of amino acid enantiomers holds significant importance in biomedical,chemical,food,and other fields.Traditional chiral recognition methods using fluorescent probes primarily rely on fluorescence intensity changes,which can compromise accuracy and repeatability.In this study,we report a novel fluorescent probe(R)-Z1 that achieves effective enantioselective recognition of chiral amino acids in water by altering emission wavelengths(>60 nm).This water-soluble probe(R)-Z1 exhibits cyan or yellow-green luminescence upon interaction with amino acid enantiomers,enabling reliable chiral detection of 14 natural amino acids.It also allows for the determination of enantiomeric excess through monitoring changes in luminescent color.Additionally,a logic operation with two inputs and three outputs was constructed based on these optical properties.Notably,amino acid enantiomers were successfully detected via dual-channel analysis at both the food and cellular levels.This study provides a new dynamic luminescence-based tool for the accurate sensing and detection of amino acid enantiomers.展开更多
Post-exercise whey protein isolate(WPI)supplement is beneficial for skeletal muscle recovery due to the stimulation of branched chain amino acids(BCAAs).This implies us that intake slow digestion rate of protein to su...Post-exercise whey protein isolate(WPI)supplement is beneficial for skeletal muscle recovery due to the stimulation of branched chain amino acids(BCAAs).This implies us that intake slow digestion rate of protein to sustain BCAAs releasing rate may facilitate muscle protein synthesis.To examine this hypothesis,we conducted a series of protein supplements including modified slow-digesting whey(SDW),whey,hydrolyzed whey and casein,orally to mice undergoing endurance running.Our results showed that the SDW gavage constant supplied BCAAs in the serum of mice within 6 h and significantly enhanced(P<0.01)endurance exercise capacity,compared to other groups.In addition,the SDW supplementation increased the crosssectional area of mice gastrocnemius fibers,as well as their muscle and liver glycogen content.It also increased the testosterone/cortisol ratio in serum and interleukin-6(IL-6)levels in muscle,while it decreased the tumor necrosis factor-alpha(TNF-α)levels and oxidative stress in muscle.Moreover,it may activate mechanistic target of rapamycin signaling by upregulating mRNA(bcat-1 and pgc-1α)expression.Thus,our findings illustrate that prolonged BCAAs supply duration promotes mice endurance running capacity and skeletal muscle growth,contributing to the advancement of sports nutrition practices.展开更多
The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen a...The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL.As the water concentration increased to 65 mg·g^(-1),the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%,and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201.When the concentration of impurities increased to a critical value,the chloroaluminate IL began to deactivate,leading to a decrease in naphthalene conversion.The critical concentrations for ethanolamine,water,methanol,ether,and diisopentyl sulfide were 33 mg·g^(-1),65 mg·g^(-1),67mg·g^(-1),87 mg·g^(-1),and 123 mg·g^(-1),respectively.Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation.The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy.2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better,but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks.2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL.With the increase inwater concentration,the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid,and the Lewis acid gradually decreased,while the Brønsted acid showed a change of increasing first and then decreasing.展开更多
Amino acids(AAs) are prevalent in source water, particularly during spring run-off. Monitoring of amino acids in source water is desirable for water treatment plants(WTP) to indicate changes in source water quality. T...Amino acids(AAs) are prevalent in source water, particularly during spring run-off. Monitoring of amino acids in source water is desirable for water treatment plants(WTP) to indicate changes in source water quality. The objective of this study was to establish analytical procedures for reliable monitoring of amino acids in source water. Therefore, we examined two different methods, large volume inject(LVI) and solid phase extraction(SPE), for sample preparation prior to HILIC-MS/MS. The LVI-HILIC-MS/MS method can provide fast and sensitive detection for clean samples, but suffers from matrix effects, resulting in irreproducible separation and shortening column lifetime. We have demonstrated that SPE was necessary prior to HILIC-MS/MS to achieve reproducible and reliable quantification of AAs in source water. A natural heterocyclic amine 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid(MTCCA) was also included in the method to indicate changes in other natural nitrogenous compounds in source water. The SPE-HILIC-MS/MS method was able to achieve limits of detection from 2.6-3400 ng/L for the amino acids and MTCCA with RSDs( n = 3) of 1.1%-4.8%. As well, retention times(RT) of the analytes were reproducible with variation less than 0.01 min( n = 3) through the entire project. We further applied the SPE-HILICMS/MS method to determine AAs in authentic source water samples collected from two drinking water treatment plants(WTPs) during the 2021 spring run-off season. The results support that the SPE-HILIC-MS/MS method does not require derivatization and can provide reliable, accurate, and robust analysis of AAs and MTCCA in source water, supporting future monitoring of source water quality.展开更多
The binding between NL-101, a novel nitrogen mustard anti-cancer drug, with amino acids and peptides has been investigated by high performance liquid chromatography electrospray tandem mass spectrometry(HPLC/ESI-MS/MS...The binding between NL-101, a novel nitrogen mustard anti-cancer drug, with amino acids and peptides has been investigated by high performance liquid chromatography electrospray tandem mass spectrometry(HPLC/ESI-MS/MS). This study offers supporting data of the interaction among drug and amino acids and peptides, which could potentially explain the cytotoxic and mutagenic effects of the drug. Collision-induced dissociation(CID) experiment demonstrated that under the same collision energy, the amino group combined with NL-101 adducts are sensitive and often produce more fragment ions; the carboxyl group combined with NL-101 adducts are hard to break and display fewer fragment ions. In addition, when other group(like sulfhydryl group) of amino acids binds to NL-101, CID spectra show different fragmentation pattern. These differences could display structural information about the drug adducts and be utilized as location of the authentic binding sites.展开更多
A novel method for determination of amino acids in individual human red blood cells has been developed. In this method, the derivatization reagents (NDA and CN-) are introduced into living cells by electroporation. ...A novel method for determination of amino acids in individual human red blood cells has been developed. In this method, the derivatization reagents (NDA and CN-) are introduced into living cells by electroporation. After completion of derivatization, the amino acids in a single cell is determined by capillary zone electrophoresis with end-column amperometric detection.展开更多
Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic netw...Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains unclear.Through metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar fermentation.Taxonomic profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism pathways.The metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was illuminated.The results revealed that 5 functional genera were closely involved in FAA biosynthesis.This study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.展开更多
AIM: To determine the differences of amino acid(AA) levels in experimental autoimmune uveoretinitis(EAU). METHODS: AA analysis of the plasma samples in EAU rats induced by interphotoreceptor retinoid-binding protein e...AIM: To determine the differences of amino acid(AA) levels in experimental autoimmune uveoretinitis(EAU). METHODS: AA analysis of the plasma samples in EAU rats induced by interphotoreceptor retinoid-binding protein emulsion were performed with high performance liquid chromatography(HPLC) and phenylisothiocyanate(PITC) pre-column derivation methods were performed. Using partial least squares discriminant analysis(PLS-DA), the potential biomarkers were identified in EAU rat plasma, and the metabolic pathways related to EAU were further analyzed. RESULTS: The method results showed that linear(r≥0.9957), intra-day reproducible [relative standard deviation(RSD)=0.04%-1.33%], inter-day reproducible(RSD=0.06%-2.07%), repeatability(RSD=0.03%-0.89%), stability(RSD=0.05%-2.48%) and recovery(RSD=1.98%-4.39%), with detection limits of 0.853-11.4 ng/mL. The metabolic profile in EAU rats was different from that in the control groups five AAs concentrations were increased and nine AAs were reduced. Moreover, five metabolic pathways were related to the development of EAU. CONCLUSION: The developed method is a simple, rapid and convenient for determination of AAs in EAU rat plasma, and these findings will provide a comprehensiveinsight on the metabolic profiling of the pathological changes in EAU.展开更多
The composition and quantity of amino acids influence the protein content and nutritional value of soybeans and also have an important impact upon soybean quality.After integrating and proofreading 140 original QTLs a...The composition and quantity of amino acids influence the protein content and nutritional value of soybeans and also have an important impact upon soybean quality.After integrating and proofreading 140 original QTLs associated with amino acid contentfrom soybase(http://www.soybase.org/),138 QTLs were further analyzed to determine high-confidence QTL regions.Meta-analysis was first carried out using the Bio Mercator ver.2.1 software,yielding 33 consensus QTLs.The consensus QTL confidence intervals(CIs)ranged from 0.07 to 19.85 Mb.Next,the overview method was used to optimize the CIs,and 57"real"QTLs were mapped.Candidate genes in the consensus QTL regions were obtained from Phytozome and were annotated using the Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG),Swissprot,and gene annotation databases.Finally,16 unpublished candidate genes controlling the content of five types of amino acids were identified with Blast.These results laid the foundation for fine mapping of soybean amino acid-related QTLs and marker-assisted selection.展开更多
Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper stud...Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper studies protein molecule from the algebraic point of view. The algebraic system （∑, ＋, ＊） is introduced, where ∑ is the set of 64 codons. According to the characteristics of （∑, ＋, ＊）, a novel quasi-amino acids code classification method is introduced and the corresponding algebraic operation table over the set ZU of the 16 kinds of quasi-amino acids is established. The internal relation is revealed about quasi-amino acids. The results show that there exist some very close correlations between the properties of the quasi-amino acids and the codon. All these correlation relationships may play an important part in establishing the logic relationship between codons and the quasi-amino acids during the course of life origination. According to Ma F et al （2003 J. Anhui Agricultural University 30 439）, the corresponding relation and the excellent properties about amino acids code are very difficult to observe. The present paper shows that （ZU, ＋,×） is a field. Furthermore, the operational results display that the eodon tga has different property from other stop codons. In fact, in the mitochondrion from human and ox genomic codon, tga is just tryptophane, is not the stop codon like in other genetic code, it is the case of the Chen W C et al （2002 Acta Biophysiea Siniea 18（1） 87）. The present theory avoids some inexplicable events of the 20 kinds of amino acids code, in other words it solves the problem of ＇the 64 codon assignments of mRNA to amino acids is probably completely wrong＇ proposed by Yang （2006 Progress in Modern Biomedicine 6 3）.展开更多
BACKGROUND Liver cirrhosis(LC)is currently the 11^(th) most common cause of death and 15^(th) cause of morbidity globally.The treatment of LC is mainly aimed at etiological intervention,lifestyle intervention,preventi...BACKGROUND Liver cirrhosis(LC)is currently the 11^(th) most common cause of death and 15^(th) cause of morbidity globally.The treatment of LC is mainly aimed at etiological intervention,lifestyle intervention,prevention and treatment of complications and nutritional treatment.Nutritional treatment of LC mainly includes increasing dietary intake,food intake time and branched-chain amino acids(BCAAs).Despite the recommendation of BCAAs in some guidelines,adverse effects have been reported in studies so the efficacy and safety of BCAAs remain controversial.Currently,BCAAs have been widely used in chronic liver disease,while the summary of the effect of BCAAs on long-term prognosis is rare.AIM To determine the effects of BCAAs in patients with LC.METHODS The PubMed,Cochrane Library,Embase and Web of Science databases were searched.The retrieval deadline was 1 October 2021 and there were no language restrictions set in the retrieval.The study was performed in strict accordance with the inclusion and exclusion criteria.Nine studies were finally included.The primary outcome was complications of LC.The secondary outcomes were nutritional status and liver function.This meta-analysis used the Review Manager,version 5 statistical package(Cochrane Collaboration,Oxford,England)for analysis.RESULTS The analysis included nine studies that consisted of 1080 patients(554 in the BCAA groups and526 in the control groups).The nine studies were randomized control trials(RCTs).The quality of the studies was assessed using the risk of bias method recommended by the Cochrane Collaboration.BCAAs reduced the rate of complications in LC patients[Risk ratio:0.70,95%confidence interval(CI):0.56-0.88,P=0.002]and improved patients’albumin levels[std mean difference SMD:0.26,95%CI:0.12-0.40,P=0.0002].Meanwhile,BCAAs significantly ameliorated the levels of alanine transaminase(SMD:-2.03,95%CI:-2.52 to-1.53,P<0.00001)and aspartate aminotransferase(SMD:-1.8,95%CI:-2.14 to-1.46,P<0.00001).Meanwhile,glucose in the LC was significantly increased in BCAA-treated patients(MD:13.04,95%CI:6.81-19.89,P=0.0002).CONCLUSION BCAAs reduce the incidence of complications in patients with LC and ameliorate nutritional status.展开更多
Many of the extraction and amino acid analysis methodologies currently employed do not provide complete analysis of all the physiological amino acids and biogenic amines. Extraction procedures frequently employ dilute...Many of the extraction and amino acid analysis methodologies currently employed do not provide complete analysis of all the physiological amino acids and biogenic amines. Extraction procedures frequently employ dilute acid which partially converts gln and asn to glu and asp. A commonly used pre-column derivatizing agent, o-phthalaldehyde, does not react with the imino acids, pro and hydroxypro. The purpose of this investigation was to integrate extraction and analysis procedures into a reliable method for measuring the complete physiological amino acid profiles of fruit and vegetables using HPLC instrumentation commonly available to most laboratories. Water extraction of ground, frozen-thawed tissues effected complete recovery of the physiological amino acids as demonstrated by spiking experiments and tissue combination experiments. HPLC of dabsyl derivatives of the free amino acids allowed their quantification in a selection of fruit and vegetables. Physiological amino acid levels were determined for peach, apple, potato, onion, tomato, bell pepper, broccoli, and seven types of cucurbits. The coefficient of variation for estimation of an amino acid level generally fell in the range of 5% to 7%. Because of marked variability in physiological amino acid content as a result of growing conditions, cultural practices, and inherent cultivar differences, comparisons of results with literature values were not possible.展开更多
The six antigens of Cysticercus cellulosae: CFag, CSag, CBWag, CWag, UCWag and TSag were prepared respectively. The amino acids of the antigens were determined quantitative by automatic amino acid analyzer. The relati...The six antigens of Cysticercus cellulosae: CFag, CSag, CBWag, CWag, UCWag and TSag were prepared respectively. The amino acids of the antigens were determined quantitative by automatic amino acid analyzer. The relationship of original reaction was confirmed between amino acids and antigens. The results showed that there were 17 amino acids among all of the antigens. There were no significant difference (P >0.05) of Asp, Clu, Lys, His in composition of all antigens by data analysis software SPSS. There are also no significant difference (P >0.05) in the composition of all amino acids between CSag and CBWag. The composition of Thr, Ser, Tyr, Ved, Pro in UCWag shows significant difference (P<0.05) with other antigens. The sensitivity and peculiarity of UCWag are higher than that of the others. Pro and Glu show significant linear correspondence with sensitivity and peculiarity of antigens respectively.展开更多
BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon e...BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon emission computed tomography(SPECT).Since amino acids play a minor role in metabolism of inflammatory cells,the potential of the SPECT tracer,3-[ 123 I]iodo-L-α-methyltyrosine(123I-IMT),for detecting pancreatic cancer was examined in xenotransplantation models of human pancreatic carcinoma in mice. METHODS: 123 I-IMT was injected to eight mice inoculated with subcutaneous or orthotopic pancreatic tumors.Fused high-resolution-micro-SPECT(Hi-SPECT)and magnetic resonance imaging were performed.The gene expression level of L amino acid transport-system 1(LAT1)was analyzed and correlated with tumor uptake of 123 I-IMT. RESULTS:A high uptake of 123 I-IMT was detected in all tumor-bearing mice.The median tumor-to-background ratio (T/B)was 12.1(2.0-13.2)for orthotopic and 8.4(1.8-11.1)for subcutaneous xenotransplantation,respectively.Accordingly, the LAT1 expression in transplanted Colo357 cells was increased compared to non-malignant controls.CONCLUSIONS:Our mouse model could show a high 123 I-IMT uptake in pancreatic cancer.Fused MRI scans facilitate precise evaluation of uptake in the specific regions of interest.Further studies are required to confirm these findings in tumors derived from other human pancreatic cancer cells.Since amino acids play a minor role in the metabolism of inflammatory cells,the potential for application of 123 I-IMT to distinguish pancreatic tumor from inflammatory pancreatitis warrants further investigation.展开更多
Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient aerosol.Due to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challen...Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient aerosol.Due to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution conditions.In this study,we present an optimized method for analyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fuorescence detector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analysis in ambient aerosol samples were investigated especially for those collected in pollution episodes.The results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH_(4)^(+).To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample extract.After pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by HPLC-FLD.The recoveries are in the range of 67%-106%.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enantiomers determination.We suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the infuence of biomass burning.展开更多
基金supported by the director of Indian Council of Agricultural Research and International Rice Research Institute (ICAR-CRRI), Cuttack, Indiathe coordinator of the ICAR-sponsored project ‘C-reactive protein (CRP) in Biofortification in Selected Crops’, India
文摘CR Dhan 310(CRD310),a biofortified rice variety,contains a significantly higher level of grain protein compared with its recurrent parent Naveen(NV),as well as most adapted high-yielding rice varieties in India.Although a limited investigation depicted that CRD310 contained higher levels of glutelin and some essential amino acids,detailed biochemical,molecular,and cellular mechanisms remain to be studied.As one of the means to identify the proteins and understand the underlying mechanism of higher proteins accumulation in grains of CRD310,the comparative proteomics was undertaken on grains of CRD310 and NV at the yellow ripening stage.
基金funded by the Key Scientific and Technological Grant of Zhejiang(No.2021C02069-6)the Earmarked Fund(No.CARS-48)K.C.Wong Magana Fund in Ningbo University。
文摘This study examined four species of Scylla genus(S.paramamosain,S.olivacea,S.serrata,and S.tranquebarica)morphologically and molecularly.Morphologically,distinct frontal lobe spine shapes and colorations were observed.Using HRM genotyping with CSN9 primers,we identified clear species-specific melting curve distinctions.The Tm values of S.serrata,S.paramamosain,S.tranquebarica and S.olivacea are 79.55℃,80.12℃,78.12℃ and 82.04℃,respectively.Sequencing data validated these results,revealing 28 SNPs and 9 haplotypes.Amino acid analysis showed arginine dominance in S.paramamosain,which was 40.64 mg g^(-1),and a TFAA range of 135.70-149.65 mg g^(-1).A total of 26 fatty acids were identified,while S.paramamosain showed the highest concentration(P<0.05).EPA was a major component(16.17%-23.26%),while S.paramamosain exhibited the highest levels.Principal component analysis and cluster analysis highlighted distinct species groupings based on amino acid and fatty acid profiles.These findings provide comprehensive insights into Scylla species'morphological,molecular,and biochemical diversities.
基金supported by the Fundamental Research Funds for the Public Research Institutes of Chinese Academy of Inspection and Quarantine(2022JK04).
文摘Sesame is one of the eight major allergens that cause food allergies.Study of the epitopes of sesame allergens is important for understanding their sensitization mechanisms.Currently,less information is available on the epitope studies of sesame allergens.In this study,we analyzed the molecular characteristics,structure and homology of Ses i 3,one of the important sesame allergens.We predicted the B-cell linear epitopes of Ses i 3 using bioinformatics tools and characterized them by slot blot immuno-microarrays technology.Eight peptides as B-cell linear epitopes of Ses i 3 were identified,in addition,key amino acids in these epitopes were predicted and leucine 422 was identified as a key amino acid.The present work will contribute to further understanding of the sesame allergen and provide some help in the prevention and treatment of sesame allergy.
基金supported by a grant from the Dalian Science and Technology Innovation Fund Program(No.2024JJ13PT070)United Foundation for Dalian Institute of Chemical Physics,Chinese Academy of Sciences and the Second Hospital of Dalian Medical University(No.DMU-2&DICP UN202410)Dalian Life and Health Field Guidance Program Project(No.2024ZDJH01PT084).
文摘Metabolic reprogramming involving branched-chain amino acids(BCAAs)—leucine,isoleucine,and valine—is increasingly recognized as pivotal in cancer progression,metastasis,and immune modulation.This review comprehensively explores how cancer cells rewire BCAA metabolism to enhance proliferation,survival,and therapy resistance.Tumors manipulate BCAA uptake and catabolism via high expression of transporters like L-type amino acid transporter 1(LAT1)and enzymes including branched chain amino acid transaminase 1(BCAT1),branched chain amino acid transaminase 2(BCAT2),branched-chain alpha-keto acid dehydrogenase(BCKDH),and branched chain alpha-keto acid dehydrogenase kinase(BCKDK).These alterations sustain energy production,biosynthesis,redox homeostasis,and oncogenic signaling(especially mammalian target of rapamycin complex 1[mTORC1]).Crucially,tumor-driven BCAA depletion also shapes an immunosuppressive microenvironment,impairing anti-tumor immunity by limiting essential nutrients for T cells and natural killer(NK)cells.Innovative therapeutic strategies targeting BCAA pathways—ranging from selective small-molecule inhibitors(e.g.,LAT1 and BCAT1/2)to dietary modulation—have shown promising preclinical and early clinical efficacy,highlighting their potential to exploit metabolic vulnerabilities in cancer cells while bolstering immune responses.By integrating multi-omics data and precision targeting approaches,this review underscores the translational significance of BCAA metabolic reprogramming,positioning it as a novel frontier in cancer treatment.
基金partly funded by National Key R&D Program of China(2023YFD1301405)the 2115 Talent Development Program of China Agricultural University。
文摘Skeletal muscle accounts for approximately 40%of body mass and 50%–75%of whole-body protein,playing a central role in meat production and quality.Efficient protein synthesis in skeletal muscle relies on an adequate supply of nutrient substrates and a balanced amino acid profile.Branched-chain amino acids(BCAA),including leucine(Leu),isoleucine(Ile),and valine(Val),are the most abundant essential amino acids in skeletal muscle and contribute to both protein synthesis and oxidative energy production.Additionally,BCAA function as signaling molecules that regulate gene expression and protein phosphorylation cascades,which significantly influence physiological processes,such as protein synthesis and degradation,glucose and lipid metabolism,and cell apoptosis and autophagy.These processes are primarily mediated through the PI3K/AKT/AMPK/mTOR signaling pathways.This review summarizes BCAA transporters and catabolic metabolism,their role as signaling molecules in regulating protein metabolism and glucose and lipid equilibrium,and applications in animal production.These findings offer both theoretical insights and practical guidelines for the precise regulation of feed efficiency and production performance through tailored dietary BCAA supplementations.
基金the financial support from the National Natural Science Foundation of China(Nos.22377097,22307036,22074114)Natural Science Foundation of Hubei Province of China(Nos.2020CFB623,2021CFB556)Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education(No.LCX202305)。
文摘The detection of amino acid enantiomers holds significant importance in biomedical,chemical,food,and other fields.Traditional chiral recognition methods using fluorescent probes primarily rely on fluorescence intensity changes,which can compromise accuracy and repeatability.In this study,we report a novel fluorescent probe(R)-Z1 that achieves effective enantioselective recognition of chiral amino acids in water by altering emission wavelengths(>60 nm).This water-soluble probe(R)-Z1 exhibits cyan or yellow-green luminescence upon interaction with amino acid enantiomers,enabling reliable chiral detection of 14 natural amino acids.It also allows for the determination of enantiomeric excess through monitoring changes in luminescent color.Additionally,a logic operation with two inputs and three outputs was constructed based on these optical properties.Notably,amino acid enantiomers were successfully detected via dual-channel analysis at both the food and cellular levels.This study provides a new dynamic luminescence-based tool for the accurate sensing and detection of amino acid enantiomers.
基金financially supported by the Fundamental Research Funds for the Central Universities(JUSRP622014)Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province,Jiangnan University(2022-3-2)National Key Research and Development Program of China(2022YFF1100300).
文摘Post-exercise whey protein isolate(WPI)supplement is beneficial for skeletal muscle recovery due to the stimulation of branched chain amino acids(BCAAs).This implies us that intake slow digestion rate of protein to sustain BCAAs releasing rate may facilitate muscle protein synthesis.To examine this hypothesis,we conducted a series of protein supplements including modified slow-digesting whey(SDW),whey,hydrolyzed whey and casein,orally to mice undergoing endurance running.Our results showed that the SDW gavage constant supplied BCAAs in the serum of mice within 6 h and significantly enhanced(P<0.01)endurance exercise capacity,compared to other groups.In addition,the SDW supplementation increased the crosssectional area of mice gastrocnemius fibers,as well as their muscle and liver glycogen content.It also increased the testosterone/cortisol ratio in serum and interleukin-6(IL-6)levels in muscle,while it decreased the tumor necrosis factor-alpha(TNF-α)levels and oxidative stress in muscle.Moreover,it may activate mechanistic target of rapamycin signaling by upregulating mRNA(bcat-1 and pgc-1α)expression.Thus,our findings illustrate that prolonged BCAAs supply duration promotes mice endurance running capacity and skeletal muscle growth,contributing to the advancement of sports nutrition practices.
基金financial support of the Scientific Research Funds of Huaqiao University (605-50Y17073)
文摘The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL.As the water concentration increased to 65 mg·g^(-1),the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%,and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201.When the concentration of impurities increased to a critical value,the chloroaluminate IL began to deactivate,leading to a decrease in naphthalene conversion.The critical concentrations for ethanolamine,water,methanol,ether,and diisopentyl sulfide were 33 mg·g^(-1),65 mg·g^(-1),67mg·g^(-1),87 mg·g^(-1),and 123 mg·g^(-1),respectively.Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation.The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy.2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better,but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks.2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL.With the increase inwater concentration,the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid,and the Lewis acid gradually decreased,while the Brønsted acid showed a change of increasing first and then decreasing.
基金supported by the Natural Sciences and Engineering Research Council of Canada, Alberta Innovatesthe Canada Research Chairs Program。
文摘Amino acids(AAs) are prevalent in source water, particularly during spring run-off. Monitoring of amino acids in source water is desirable for water treatment plants(WTP) to indicate changes in source water quality. The objective of this study was to establish analytical procedures for reliable monitoring of amino acids in source water. Therefore, we examined two different methods, large volume inject(LVI) and solid phase extraction(SPE), for sample preparation prior to HILIC-MS/MS. The LVI-HILIC-MS/MS method can provide fast and sensitive detection for clean samples, but suffers from matrix effects, resulting in irreproducible separation and shortening column lifetime. We have demonstrated that SPE was necessary prior to HILIC-MS/MS to achieve reproducible and reliable quantification of AAs in source water. A natural heterocyclic amine 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid(MTCCA) was also included in the method to indicate changes in other natural nitrogenous compounds in source water. The SPE-HILIC-MS/MS method was able to achieve limits of detection from 2.6-3400 ng/L for the amino acids and MTCCA with RSDs( n = 3) of 1.1%-4.8%. As well, retention times(RT) of the analytes were reproducible with variation less than 0.01 min( n = 3) through the entire project. We further applied the SPE-HILICMS/MS method to determine AAs in authentic source water samples collected from two drinking water treatment plants(WTPs) during the 2021 spring run-off season. The results support that the SPE-HILIC-MS/MS method does not require derivatization and can provide reliable, accurate, and robust analysis of AAs and MTCCA in source water, supporting future monitoring of source water quality.
基金supported by the National Natural Science Foundation of China (Nos. 21327010, 21372199)
文摘The binding between NL-101, a novel nitrogen mustard anti-cancer drug, with amino acids and peptides has been investigated by high performance liquid chromatography electrospray tandem mass spectrometry(HPLC/ESI-MS/MS). This study offers supporting data of the interaction among drug and amino acids and peptides, which could potentially explain the cytotoxic and mutagenic effects of the drug. Collision-induced dissociation(CID) experiment demonstrated that under the same collision energy, the amino group combined with NL-101 adducts are sensitive and often produce more fragment ions; the carboxyl group combined with NL-101 adducts are hard to break and display fewer fragment ions. In addition, when other group(like sulfhydryl group) of amino acids binds to NL-101, CID spectra show different fragmentation pattern. These differences could display structural information about the drug adducts and be utilized as location of the authentic binding sites.
基金This project was supported by the National Natural Science Foundation of China the Natural Science Foundation of Shandong Province and the Key State Laboratory of Electroanalytical ChemistryChangchun Institute of Applied Chemistry,Chinese Academy
文摘A novel method for determination of amino acids in individual human red blood cells has been developed. In this method, the derivatization reagents (NDA and CN-) are introduced into living cells by electroporation. After completion of derivatization, the amino acids in a single cell is determined by capillary zone electrophoresis with end-column amperometric detection.
基金The authors are grateful for the financial support from National Natural Science Foundation of China(32001728).
文摘Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains unclear.Through metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar fermentation.Taxonomic profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism pathways.The metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was illuminated.The results revealed that 5 functional genera were closely involved in FAA biosynthesis.This study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.
基金Supported by the National Natural Science Foundation of China (No.81373826 No.81674032)+1 种基金Natural Science Foundation of Shandong Province (No. ZR2014HQ074)Key Development & Research Program of Shandong Province (No.2017GSF19110)
文摘AIM: To determine the differences of amino acid(AA) levels in experimental autoimmune uveoretinitis(EAU). METHODS: AA analysis of the plasma samples in EAU rats induced by interphotoreceptor retinoid-binding protein emulsion were performed with high performance liquid chromatography(HPLC) and phenylisothiocyanate(PITC) pre-column derivation methods were performed. Using partial least squares discriminant analysis(PLS-DA), the potential biomarkers were identified in EAU rat plasma, and the metabolic pathways related to EAU were further analyzed. RESULTS: The method results showed that linear(r≥0.9957), intra-day reproducible [relative standard deviation(RSD)=0.04%-1.33%], inter-day reproducible(RSD=0.06%-2.07%), repeatability(RSD=0.03%-0.89%), stability(RSD=0.05%-2.48%) and recovery(RSD=1.98%-4.39%), with detection limits of 0.853-11.4 ng/mL. The metabolic profile in EAU rats was different from that in the control groups five AAs concentrations were increased and nine AAs were reduced. Moreover, five metabolic pathways were related to the development of EAU. CONCLUSION: The developed method is a simple, rapid and convenient for determination of AAs in EAU rat plasma, and these findings will provide a comprehensiveinsight on the metabolic profiling of the pathological changes in EAU.
基金financially supported by the National Key R&D Program of China(2016YFD0100500,2016YFD0100300,2016YFD0100201-21)the"Challenge Cup"National College Student Curricular Academic Science and Technology Works Competition of Ministry of Education of China(to Gong Qianchun,guided by Qi Zhaoming)+5 种基金the National Natural Science Foundation of China(31701449,31471516,31401465,31400074,31501332)the China Post Doctoral Project(2015M581419)the Dongnongxuezhe Project(to Chen Qingshan),Chinathe Young Talent Project(to Qi Zhaoming)of Northeast Agriculture University,China(518062)the Heilongjiang Funds for Distinguished Young Scientists,China(JC2016004)the Outstanding Academic Leaders Projects of Harbin,China(2015RQXXJ018)
文摘The composition and quantity of amino acids influence the protein content and nutritional value of soybeans and also have an important impact upon soybean quality.After integrating and proofreading 140 original QTLs associated with amino acid contentfrom soybase(http://www.soybase.org/),138 QTLs were further analyzed to determine high-confidence QTL regions.Meta-analysis was first carried out using the Bio Mercator ver.2.1 software,yielding 33 consensus QTLs.The consensus QTL confidence intervals(CIs)ranged from 0.07 to 19.85 Mb.Next,the overview method was used to optimize the CIs,and 57"real"QTLs were mapped.Candidate genes in the consensus QTL regions were obtained from Phytozome and were annotated using the Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG),Swissprot,and gene annotation databases.Finally,16 unpublished candidate genes controlling the content of five types of amino acids were identified with Blast.These results laid the foundation for fine mapping of soybean amino acid-related QTLs and marker-assisted selection.
基金Project supported in part by the International Technology Collaboration Research Program of China (Grant No 2007DFA706700)
文摘Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper studies protein molecule from the algebraic point of view. The algebraic system （∑, ＋, ＊） is introduced, where ∑ is the set of 64 codons. According to the characteristics of （∑, ＋, ＊）, a novel quasi-amino acids code classification method is introduced and the corresponding algebraic operation table over the set ZU of the 16 kinds of quasi-amino acids is established. The internal relation is revealed about quasi-amino acids. The results show that there exist some very close correlations between the properties of the quasi-amino acids and the codon. All these correlation relationships may play an important part in establishing the logic relationship between codons and the quasi-amino acids during the course of life origination. According to Ma F et al （2003 J. Anhui Agricultural University 30 439）, the corresponding relation and the excellent properties about amino acids code are very difficult to observe. The present paper shows that （ZU, ＋,×） is a field. Furthermore, the operational results display that the eodon tga has different property from other stop codons. In fact, in the mitochondrion from human and ox genomic codon, tga is just tryptophane, is not the stop codon like in other genetic code, it is the case of the Chen W C et al （2002 Acta Biophysiea Siniea 18（1） 87）. The present theory avoids some inexplicable events of the 20 kinds of amino acids code, in other words it solves the problem of ＇the 64 codon assignments of mRNA to amino acids is probably completely wrong＇ proposed by Yang （2006 Progress in Modern Biomedicine 6 3）.
基金Supported by the Key Research and Development Projects of Sichuan Science and Technology Department,No.22ZDYF1691,No.2018FZ0062,and No.2020YFS0410。
文摘BACKGROUND Liver cirrhosis(LC)is currently the 11^(th) most common cause of death and 15^(th) cause of morbidity globally.The treatment of LC is mainly aimed at etiological intervention,lifestyle intervention,prevention and treatment of complications and nutritional treatment.Nutritional treatment of LC mainly includes increasing dietary intake,food intake time and branched-chain amino acids(BCAAs).Despite the recommendation of BCAAs in some guidelines,adverse effects have been reported in studies so the efficacy and safety of BCAAs remain controversial.Currently,BCAAs have been widely used in chronic liver disease,while the summary of the effect of BCAAs on long-term prognosis is rare.AIM To determine the effects of BCAAs in patients with LC.METHODS The PubMed,Cochrane Library,Embase and Web of Science databases were searched.The retrieval deadline was 1 October 2021 and there were no language restrictions set in the retrieval.The study was performed in strict accordance with the inclusion and exclusion criteria.Nine studies were finally included.The primary outcome was complications of LC.The secondary outcomes were nutritional status and liver function.This meta-analysis used the Review Manager,version 5 statistical package(Cochrane Collaboration,Oxford,England)for analysis.RESULTS The analysis included nine studies that consisted of 1080 patients(554 in the BCAA groups and526 in the control groups).The nine studies were randomized control trials(RCTs).The quality of the studies was assessed using the risk of bias method recommended by the Cochrane Collaboration.BCAAs reduced the rate of complications in LC patients[Risk ratio:0.70,95%confidence interval(CI):0.56-0.88,P=0.002]and improved patients’albumin levels[std mean difference SMD:0.26,95%CI:0.12-0.40,P=0.0002].Meanwhile,BCAAs significantly ameliorated the levels of alanine transaminase(SMD:-2.03,95%CI:-2.52 to-1.53,P<0.00001)and aspartate aminotransferase(SMD:-1.8,95%CI:-2.14 to-1.46,P<0.00001).Meanwhile,glucose in the LC was significantly increased in BCAA-treated patients(MD:13.04,95%CI:6.81-19.89,P=0.0002).CONCLUSION BCAAs reduce the incidence of complications in patients with LC and ameliorate nutritional status.
文摘Many of the extraction and amino acid analysis methodologies currently employed do not provide complete analysis of all the physiological amino acids and biogenic amines. Extraction procedures frequently employ dilute acid which partially converts gln and asn to glu and asp. A commonly used pre-column derivatizing agent, o-phthalaldehyde, does not react with the imino acids, pro and hydroxypro. The purpose of this investigation was to integrate extraction and analysis procedures into a reliable method for measuring the complete physiological amino acid profiles of fruit and vegetables using HPLC instrumentation commonly available to most laboratories. Water extraction of ground, frozen-thawed tissues effected complete recovery of the physiological amino acids as demonstrated by spiking experiments and tissue combination experiments. HPLC of dabsyl derivatives of the free amino acids allowed their quantification in a selection of fruit and vegetables. Physiological amino acid levels were determined for peach, apple, potato, onion, tomato, bell pepper, broccoli, and seven types of cucurbits. The coefficient of variation for estimation of an amino acid level generally fell in the range of 5% to 7%. Because of marked variability in physiological amino acid content as a result of growing conditions, cultural practices, and inherent cultivar differences, comparisons of results with literature values were not possible.
文摘The six antigens of Cysticercus cellulosae: CFag, CSag, CBWag, CWag, UCWag and TSag were prepared respectively. The amino acids of the antigens were determined quantitative by automatic amino acid analyzer. The relationship of original reaction was confirmed between amino acids and antigens. The results showed that there were 17 amino acids among all of the antigens. There were no significant difference (P >0.05) of Asp, Clu, Lys, His in composition of all antigens by data analysis software SPSS. There are also no significant difference (P >0.05) in the composition of all amino acids between CSag and CBWag. The composition of Thr, Ser, Tyr, Ved, Pro in UCWag shows significant difference (P<0.05) with other antigens. The sensitivity and peculiarity of UCWag are higher than that of the others. Pro and Glu show significant linear correspondence with sensitivity and peculiarity of antigens respectively.
基金supported in part by a BMBF grant(TOMCAT)given to H.K.the Molecular Imaging North Competence Center(MOIN-CC)
文摘BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon emission computed tomography(SPECT).Since amino acids play a minor role in metabolism of inflammatory cells,the potential of the SPECT tracer,3-[ 123 I]iodo-L-α-methyltyrosine(123I-IMT),for detecting pancreatic cancer was examined in xenotransplantation models of human pancreatic carcinoma in mice. METHODS: 123 I-IMT was injected to eight mice inoculated with subcutaneous or orthotopic pancreatic tumors.Fused high-resolution-micro-SPECT(Hi-SPECT)and magnetic resonance imaging were performed.The gene expression level of L amino acid transport-system 1(LAT1)was analyzed and correlated with tumor uptake of 123 I-IMT. RESULTS:A high uptake of 123 I-IMT was detected in all tumor-bearing mice.The median tumor-to-background ratio (T/B)was 12.1(2.0-13.2)for orthotopic and 8.4(1.8-11.1)for subcutaneous xenotransplantation,respectively.Accordingly, the LAT1 expression in transplanted Colo357 cells was increased compared to non-malignant controls.CONCLUSIONS:Our mouse model could show a high 123 I-IMT uptake in pancreatic cancer.Fused MRI scans facilitate precise evaluation of uptake in the specific regions of interest.Further studies are required to confirm these findings in tumors derived from other human pancreatic cancer cells.Since amino acids play a minor role in the metabolism of inflammatory cells,the potential for application of 123 I-IMT to distinguish pancreatic tumor from inflammatory pancreatitis warrants further investigation.
基金supported by the Natural Science Foundation of China (No.41975156)。
文摘Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient aerosol.Due to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution conditions.In this study,we present an optimized method for analyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fuorescence detector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analysis in ambient aerosol samples were investigated especially for those collected in pollution episodes.The results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH_(4)^(+).To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample extract.After pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by HPLC-FLD.The recoveries are in the range of 67%-106%.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enantiomers determination.We suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the infuence of biomass burning.
