Capillary zone electrophoresis has been applied to the analysis of nucleotides. The effects of buffer concentration. pH and other operating conditions on the separation were investigated and optimized. By using the me...Capillary zone electrophoresis has been applied to the analysis of nucleotides. The effects of buffer concentration. pH and other operating conditions on the separation were investigated and optimized. By using the method, separation and identification of nuclotides in swine tissues were completed.展开更多
Aim To synthesize isonucleoside-incorporated oligonucleotides and investigatetheir binding abilities with complementary sequences. Methods The synthesis was performed on DNAsynthesizer, and the binding behavior was in...Aim To synthesize isonucleoside-incorporated oligonucleotides and investigatetheir binding abilities with complementary sequences. Methods The synthesis was performed on DNAsynthesizer, and the binding behavior was investigated by thermal denaturation studies. Results Fourkinds of single isonucleoside containing oligonucleotides were synthesized. The results of thermaldenaturation showed that the existence of isonucleoside decreased the stability of duplex, and theeffect was more obvious when the isonucleoside was in the middle of the sequence. No obviousdifference was observed when 6'-OH of isonucleoside was free or was protected by allyl group.Conclusions The existence of isonucleoside in oli-gonucleotide makes chain twist and decreased thestability of duplex.展开更多
Background： Dietary nucleotides, considered as antibiotics alternative, were shown to have positive effects on intestinal hyperaemia, systemic immunity, small-intestinal growth, and hepatic composition in pigs. Howev...Background： Dietary nucleotides, considered as antibiotics alternative, were shown to have positive effects on intestinal hyperaemia, systemic immunity, small-intestinal growth, and hepatic composition in pigs. However, there is no previous research on nucleotide supplementation in weanling pigs under an oral challenged E. coil K88. Therefore, 2 experiments were conducted to investigate the effects of dietary nucleotides on weanling pig growth performance, nutrient digestibility, fecal score, and blood profile after being orally challenged with E. coli K88. Methods： In Exp. 1, a total of 140 weanling pigs [8.33 ± 0.33 kg of body weight （BW）, 28-d old] were used in this 42-d feeding trial. Pigs were distributed into 1 of 4 treatments, 5 pigs/pen （3 barrows and 2 gilts） and 7 pens/treatment. Treatments were a control basal diet （CON） or the CON supplemented with 150 （R150）, 220 （R220）, or 275 （R275） mg/kg to give the three treatment diets. In Exp. 2, 28 weanling pigs （BW = 8.40 ± 0.22 kg, 28-d old） were distributed into 1 of 4 treatments to give 1 pig/pen and 7 pens/treatment in a 42-d feeding and challenge trial. Dietary treatments were the same as in Exp. 1. 0n d 14, all those pigs （BW= 13.3±0.15 kg, 42-d old） were orally dosed with 1.5 mL suspension containing 10 cfu/mL of E. coli K88. Twenty four hours after challenge, blood and excreta samples were collected from each pigs for analysis. Fecal scores were measured on d 7, 14, 21, and 28 of the study. Results： In Exp. 1, overall BW, average daily gain （ADG）, gain/feed （G/F） ratio, and nutrient digestibilities were lower （P 〈 0.05） in CON group compared with the nucleotides fed pigs. In Exp. 2, after challenge, IgA, IgM, and IGF-I were higher （P〈 0.05） in the nucleotide groups compared with CON. However, the nucleotide groups had lower （P 〈 0.05） cortisol and TNF-o compared with CON. Fecal E. coil counts and fecal score for the nucleotide groups were lower （P 〈 0.05） than for CON. Conclusions： In conclusion, dietary nucleotides supplementation could improve growth performance, nutrient digestibility, immune status, microbial balance, reduce diarrhea, and provide protection against enterotoxigenic E. coli K88 infection in weanling pigs.展开更多
Nucleotides (NT) and human milk oligosaccharides (HMO) individually affect epithelial cell growth, but their combined effects had not been studied. Herein, the impact of NT and HMO on cell proliferation, apoptosis, ne...Nucleotides (NT) and human milk oligosaccharides (HMO) individually affect epithelial cell growth, but their combined effects had not been studied. Herein, the impact of NT and HMO on cell proliferation, apoptosis, necrosis and cell cycle in the fetal epithelial cell line (FHs-74 Int) was determined. Cells were incubated with media containing 2.5% FBS and no epidermal growth factor (Control);fucosyllactose (FL) mix [85% 2’FL/15% 3’FL], sialyllactose (SL) mix [40% 6’SL/10% 3’SL/50% sialic acid (SA)] or LNnT at 125, 250, 500 or 1000 μg/mL with and without 250 μg/mL NT (43% CMP, 18.5% UMP, 16.4% AMP, and 22.0% GMP) for 24 or 72 h. NT alone significantly increased proliferation, but did not affect cell cycle or apoptosis/necrosis. All HMO treatments at 1000 μg/mL significantly decreased proliferation and some were also inhibitory at 250 or 500 μg/mL. When NT and HMO were simultaneously added, NT ameliorated the anti-proliferative effect of HMO. FL significantly increased cells in S phase and SL and LNnT treatments significantly increased cells in G2/M and S phases, which concomitantly decreased cells in G0/G1. HMO with NT significantly decreased the percent of cells in the G2/M phase compared to HMO alone. Higher HMO doses significantly increased the percentage of apoptotic and necrotic cells compared to control. In conclusion, HMO reduced cell proliferation and this effect is partially ameliorated by NT. It appears that HMO initially induced apoptosis/necrosis, which was later evidenced by G2/M cell cycle arrest and decreased proliferation.展开更多
We measured the erythrocyte levels of principal nucleotides (ATP, ADP, AMP, GTP, GDP, GMP, IMP), nucleosides (Ado, Guo, Ino) and Hyp with HPLC. Purine concentrations were determined in the erythrocytes of 36 type 1 an...We measured the erythrocyte levels of principal nucleotides (ATP, ADP, AMP, GTP, GDP, GMP, IMP), nucleosides (Ado, Guo, Ino) and Hyp with HPLC. Purine concentrations were determined in the erythrocytes of 36 type 1 and 40 type 2 diabetic patients. The increased dephosphorylation of adenine and guanine nucleotides, indicated by increased Ado, Ino, Guo and Hyp concentrations as the products of purine nucleotide degradation, suggests serious energy metabolism disruptions in diabetes. An increase in AMP, GMP, IMP concentrations, as well as a decrease in AEC and GEC values, points to significant alterations in erythrocyte purine nucleotide concentration.展开更多
The present work revealed that the praseodymium()complex of 2carboxyethylgermanium sesquioxide(Ge132)promotes the hydrolysis of the phosphodiester linkages of 3,5cyclic adenosine monophosphate(cAMP),3,5cyclic deoxyade...The present work revealed that the praseodymium()complex of 2carboxyethylgermanium sesquioxide(Ge132)promotes the hydrolysis of the phosphodiester linkages of 3,5cyclic adenosine monophosphate(cAMP),3,5cyclic deoxyadenosine monophosphate(dcAMP),5adenosine monophosphate(5AMP)and 5deoxyadenosine monophosphate(5dAMP)under mild conditions.Both cAMP and dcAMP were hydrolyzed sitespecifically,yielding predominantly 3monophosphates,the main products of the cleavage of 5AMP and 5dAMP included adenosine(Ado),deoxyadenosine(dAdo)and free phosphates respectively.A hydrolytic mechanism was proposed for cAMP,dcAMP,5AMP and 5dAMP.展开更多
At present, there is no method for identifying meat frozen in a thermal state acceptable for production control. The role of free nucleotides in the processes of refrigeration and storage of meat, affecting the struct...At present, there is no method for identifying meat frozen in a thermal state acceptable for production control. The role of free nucleotides in the processes of refrigeration and storage of meat, affecting the structural and mechanical properties of muscle tissue, the formation of taste and its biological value is known. In this article we compared methods for identifying the thermal state of meat based on the determination of the composition and content of free nucleotides by high-performance liquid chromatography (HPLC) and spectrophotometry [SF]. High-purity reference substances were used: free nucleotides—ATP, ADP, AMP, IMP and nucleosides-inosine and hypoxanthine. It has been experimentally established that the characteristic peaks of the absorption spectra for extracts of free nucleotides of meat frozen depended from thermal state of meat. The content of ATP is 21.8 times higher in meat frozen in a fresh state, and the amount of IMF is 12.3 times lower than in meat frozen after cooling. The results of studies of meat frozen using the HPLC method and the developed SF method show the adequacy of the data obtained by both methods. SF-method based on the determination of the optical density of the extracts of free nucleotides is recommended to justify the choice of technological process meat defrost modes.展开更多
Zipf＇s approach in linguistics is utilized to analyze the statistical features of frequency and correlation of 16 nearest neighboring nucleotides （AA, AC, AG, …, TT） in 12 human chro- mosomes （Y, 22, 21, 20, 19, ...Zipf＇s approach in linguistics is utilized to analyze the statistical features of frequency and correlation of 16 nearest neighboring nucleotides （AA, AC, AG, …, TT） in 12 human chro- mosomes （Y, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, and 12）. It is found that these statistical features of nearest neighboring nucleotides in human genome： （i） the frequency distribution is a linear function, and （ii） the correlation distribution is an inverse function. The coefficients of the linear function and inverse function depend on the GC content. It proposes the correlation distribution of nearest neighboring nucleotides for the first time and extends the descriptor about nearest neighboring nueleotides.展开更多
A new version of DNA walks, where nucleotides are regarded unequal in their contribution to a walk is introduced, which allows us to study thoroughly the “fine structure” of nucleotide sequences. The approach is bas...A new version of DNA walks, where nucleotides are regarded unequal in their contribution to a walk is introduced, which allows us to study thoroughly the “fine structure” of nucleotide sequences. The approach is based on the assumption that nucleotides have an inner abstract characteristic, the determinative degree, which reflects genetic code phenomenological prop-erties and is adjusted to nucleotides physical properties. We consider each codon position independently, which gives three separate walks characterized by different angles and lengths, and that such an object is called triander which reflects the “strength” of branch. A general method for identifying DNA sequence “by triander” which can be treated as a unique “genogram” (or “gene passport”) is proposed. The two- and three-dimensional trianders are considered. The difference of sequences fine structure in genes and the intergenic space is shown. A clear triplet signal in coding sequences was found which is absent in the intergenic space and is independent from the sequence length. This paper presents the topological classification of trianders which can allow us to provide a detailed working out signatures of functionally different genomic regions.展开更多
The development of molecular probes or systems with the ability of multiple orthogonal responses is an effective approach to precisely detect biomolecules with similar chemical structures.Herein,we report the synthesi...The development of molecular probes or systems with the ability of multiple orthogonal responses is an effective approach to precisely detect biomolecules with similar chemical structures.Herein,we report the synthesis of a water-soluble TPE-based octacationic cage(1)with the compressed TPE-containing bilayer,which endows it with good fluorescence properties and potential conformation chirality.As a result,1 exhibits molecular recognition for anionic nucleotides within its two“claw”-like cavities to form 1:2 host-vip complexes in water,companying with selective turn-off fluorescence and turn-on CD responses to G/GTP over other nucleotides.展开更多
We investigate the possibility of injection of a nucleotide via single-walled carbon nanotubes (SWNTs). The collapse process of an SWNT with a large radius may proceed like falling dominoes. The characteristics of a l...We investigate the possibility of injection of a nucleotide via single-walled carbon nanotubes (SWNTs). The collapse process of an SWNT with a large radius may proceed like falling dominoes. The characteristics of a large radius SWNT are utilized to drive the nucleotide movement in the SWNT, or even to inject the stored nucleotide out of the SWNT. In this process, the lateral section of the collapsed SWNT resembles a dumbbell. Occasionally, the nucleotide in the SWNT will be inbreathed into one of the two dumbbell ends, leading to interference with the injection process. To investigate the random nature of the injection process, a series of simulations on SWNT with different lengths were carried out. It was found that the injection probability was not influenced by the tube length. Freezing the nucleotide at the beginning, or modifying the SWNT at the outlet, may serve to facilitate the injection process, as indicated by the rise in the injection probability.展开更多
New water-soluble fluorescent tetracationic imidazolium-based macrocycles are synthesized via a modular SN2 nucleophilic substitution reaction.The positive charge and acidic C-H sites of these macrocycles enable them ...New water-soluble fluorescent tetracationic imidazolium-based macrocycles are synthesized via a modular SN2 nucleophilic substitution reaction.The positive charge and acidic C-H sites of these macrocycles enable them to bind with nucleotides in water,driven by hydrogen bonds and electrostatic interactions.The binding is high affinity for suitable nucleotides.These properties position them as promising candidates for the selective sensing of nucleotides.展开更多
This study investigated the effect of dietary supplementation of yeast nucleotides on the growth, nonspecific immunity, intestine growth and intestinal microbiota of juvenile hybrid tilapia. Tilapia(initial average we...This study investigated the effect of dietary supplementation of yeast nucleotides on the growth, nonspecific immunity, intestine growth and intestinal microbiota of juvenile hybrid tilapia. Tilapia(initial average weight of 8.02 g) was fed test diets supplemented with a yeast-originated nucleotide mixture(0,0.15, 0.30, 0.60, and 1.20 g/100 g diet) for 8 weeks. Fish fed the diet with 0.60% nucleotide had significantly higher weight gain than the control group(P < 0.05). Feed efficiency was improved in the fish fed 0.60 and 1.20% nucleotide compared with that in the control group. The optimal doses of nucleotides supplementation for growth and feed efficiency of fish were determined as 0.63 and 0.81%, respectively.Intestinal growth was improved in the 0.30 and 0.60% groups, as indicated by significant increase in intestine length. The fish fed 0.60 and 1.20% nucleotide showed higher super oxide dismutase(SOD)activity and lower malondialdehyde(MDA) level in the liver than the control fish, indicating enhancement of the anti-oxidant status. Serum lysozyme activity was significantly increased in the 0.15 and 0.3%nucleotide supplementation groups, suggesting an enhancement effect on the non-specific immune response. Lastly, dietary nucleotides supplementation exerted moderate influence on the intestinal microbiota of hybrid tilapia. A reduction in the cumulative abundance of putative butyrate-producing species was observed in the intestinal microbiota of fish fed diets with 0.60% nucleotide compared with the control, implying an interaction between dietary nucleotides and butyrate production. Briefly, dietary supplementation with 0.60% nucleotide improve the growth performance, immune activity and intestine growth in tilapia.展开更多
Cancer,like other diseases accompanied by metabolic changes,shows characteristic DNA/RNA modifications and activities of modifying enzymes,resulting in fluctuations in nucleoside levels.In this study,we undertook targ...Cancer,like other diseases accompanied by metabolic changes,shows characteristic DNA/RNA modifications and activities of modifying enzymes,resulting in fluctuations in nucleoside levels.In this study,we undertook targeted metabolomic analyses of nucleotides in different cancer cell culture models using a sensitive and reproducible ion-pair HPLC method.The experimental data were analyzed by principal component analysis(PCA)to identify potential biomarkers in cancer cells,and statistical significance was determined by one-way analysis of variance.As a result,a clear differentiation of normal and tumor cells into two clusters was shown,indicating abnormal metabolism of nucleotides in tumor cells.Six variables(AMP,UDP,CTP levels with a significance of Po0.05;ATP,UTP and GMP levels with a significance of Po0.01)were considered as potential biomarkers;the content of AMP,UTP,GMP and ATP was significantly higher in cancer cells.The receiver operating characteristic(ROC)curve analysis allowed us to discriminate normal cells from tumor cells based on area under the curve(AUC).The sequence of their AUC values were:ATP(0.979)4UTP(0.938)4CTP¼GMP(0.896)4AMP(0.812)4UDP(0.792),so we conclude that ATP and UTP are the best potential biomarkers in tumor cells.This study may provide a valuable tool for studying minute alterations of intracellular nucleotide pools induced by anticancer/antiviral drugs,diseases or environmental factors.展开更多
Objective:To observe the effect of electroacupuncture(EA)pretreatment on adenine nucleotides in the myocardial tissues of the myocardial ischemia-reperfusion injury(MIRI)rats,and to explore the mechanism of EA pretrea...Objective:To observe the effect of electroacupuncture(EA)pretreatment on adenine nucleotides in the myocardial tissues of the myocardial ischemia-reperfusion injury(MIRI)rats,and to explore the mechanism of EA pretreatment on myocardial prevention and protection in MIRI rats.Methods:Forty SPF male Sprague-Dawley(SD)rats were randomly divided into 5 groups:a blank group,a sham operation group,a model group,an EA at Neiguan(PC 6)group and an EA at Hegu(LI 4)group,with 8 rats in each group.Rats in the blank group only received binding to the rat plate,30 min/time,once a day for 7 d;on the 7th day,rats in the sham operation group were subjected to threading for 40 min at the left anterior descending coronary artery without ligation,and then the rats were allowed to stand for 60 min before collection of the specimens;on the 7th day,rats in the model group were subjected to threading at the left anterior descending coronary artery with ligation,for 40 min before the blood flow was restored,and then the rats were allowed to stand for 60 min before collection of the specimens;on the 7th day of pretreatment with EA at Neiguan(PC 6)or Hegu(LI 4)for 30 min per day(once a day for 7 d),rats in the EA at Neiguan(PC 6)group and EA at Hegu(LI 4)group were subjected to modeling and sample collection same as in the model group.The left ventricular myocardium of the lower left anterior descending coronary artery was collected from rats in all 5 groups.Hematoxylin-eosin(HE)staining and transmission electron microscope(TEM)were used to observe the changes in myocardial pathological morphology.The change in the adenine nucleotide level of myocardial tissue was measured by high performance liquid chromatography(HPLC).Results:The HE staining and ultrastructure showed that the myocardial injury was severer in the model group compared with the sham operation group.Compared with the model group,the myocardial injury in the EA at Neiguan(PC 6)and the EA at Hegu(LI 4)groups was mild or hardly any.The adenine nucleotide levels in the sham operation group and the model group were all decreased compared with the blank group(all P<0.05);compared with the sham operation group,the adenine nucleotide level of the model group was also decreased,but the difference was not statistically significant(P>0.05);compared with the model group,the adenine nucleotide level in the EA at Neiguan(PC 6)group was increased(P<0.05),and the adenine nucleotide level in the EA at Hegu(LI 4)group was significantly increased(P<0.01).The adenine nucleotide level in the EA at Hegu(LI 4)group was higher than that in the EA at Neiguan(PC 6)group,but the difference was not statistically significant(P>0.05).Compared with the EA at Neiguan(PC 6)group,the levels of adenosine triphosphate(ATP),adenosine diphosphate(ADP)and adenosine monophosphate(AMP)in the EA at Hegu(LI 4)group were significantly increased(all P<0.01).Conclusion:Both EA at Neiguan(PC 6)and Hegu(LI 4)can alleviate the pathological damage to myocardium in MIRI rats,and increase the adenine nucleotide level in myocardial tissues,and thus protect MIRI rats.EA at Hegu(LI 4)has a better protective effect than Neiguan(PC 6).展开更多
A thirty-nine nucleotide fragment (nucleotides 38—76) of yeast alanyl tRNA was prepared by using calf spleen phosphodiesterase to delete C_(36)m^1I_(37) from the 3′-half molecule of this tRNA under controlled condit...A thirty-nine nucleotide fragment (nucleotides 38—76) of yeast alanyl tRNA was prepared by using calf spleen phosphodiesterase to delete C_(36)m^1I_(37) from the 3′-half molecule of this tRNA under controlled conditions. Analogs of yeast alanyl tRNA with A, G or C instead of m^1I_(37) were synthesized and their biological activities determined. The results indicated that the aminoacylation activity of these analogs was not affected in the rat liver aminoacyl-tRNA synthetase system, compared with natural yeast alanyl tRNA. However, the incorporation activity (i. e. the activity of transferring alanine into proteins) of these analogs was significantly reduced to 20—30% of that of natural yeast alanyl tRNA in the rabbit reticulocyte lysate cell-free protein synthesizing system.展开更多
Acting as immune cells,microglia play a surveillance role in central nervous system injuries and diseases.Extracellular nucleotides such as ATP and UTP,and adenosine are reported to regulate the response of microglia ...Acting as immune cells,microglia play a surveillance role in central nervous system injuries and diseases.Extracellular nucleotides such as ATP and UTP,and adenosine are reported to regulate the response of microglia to insults and disease.ATP activates P2X receptors and triggers several signal cascades,resulting in the activation of microglia.Subsequently,UDP binding to the P2Y6 receptor induces phagocytosis by microglia,while adenosine regulates process retraction in microglia.Nucleotides and adenosine leak out from dead cells and act on their corresponding receptors on microglia,stimulating the release of inflammatory factors and cytokines to provide both neurotrophic and neurotoxic effects.In this article,we review the regulatory effects of nucleotides and adenosine on microglial chemotaxis,phagocytosis,and process retraction,and summarize the activities of these cells after ischemia.展开更多
The 3' half molecule of yeast tRNAAla (nucleotides 36-75) was hybridized with a DNA fragment (5'GGAATCGAACC 3') and the hybrid was then digested with E. coli RNase H (from Boehringer). The enzyme can speci...The 3' half molecule of yeast tRNAAla (nucleotides 36-75) was hybridized with a DNA fragment (5'GGAATCGAACC 3') and the hybrid was then digested with E. coli RNase H (from Boehringer). The enzyme can specifically cleave the 3' half molecule at the 3' side of nucleotide ψ55, thus a fragment C36-ψ55 was prepared. The 3'-terminal T or Tψ of this fragment was removed by one or two cycles of periodate oxidation and $-elimination. The products were fragments C36-T54 and C36-G53. Three yeast tRNAAla fragments C56-A76, U55-A76 (with ψ55 replaced by U), U54-A76 (with T54ψ55 replaced by UU) were synthesized and ligated with three prepared fragments (C36-ψ55 C36-T54 and C36-G53) respectively by T4 RNA ligase. The products were further ligated with the 5' half molecule (nu-cleotides 1-35). Using this method, one reconstituted yeast tRNAAla (tRNAr) and two yeast tRNAAla analogs: (i) tRNAa with U55 instead of ψ55; (ii) tRNAb with U54U55 instead of T54ψ55 were synthesized. The charging and incorporation activities of these three tRNAs were determined. In comparison with the reconstituted tRNA, the charging activity was 75% for tRNAa and 45% for tRNAb and the incorporation activity was 65% for tRNAa and 70% for tRNAb. These results suggest that the modified nucleotides T54 and ψ55 play an important role in yeast tRNAAla func-tion.展开更多
Holley et al. were the first in 1965 to determine the primary sequence of a nucleic acid—yeast alanine transfer RNA. This molecule consists of 76 nucleotides, including 7 different modified nucleotides as further inv...Holley et al. were the first in 1965 to determine the primary sequence of a nucleic acid—yeast alanine transfer RNA. This molecule consists of 76 nucleotides, including 7 different modified nucleotides as further investigated by other展开更多
文摘Capillary zone electrophoresis has been applied to the analysis of nucleotides. The effects of buffer concentration. pH and other operating conditions on the separation were investigated and optimized. By using the method, separation and identification of nuclotides in swine tissues were completed.
文摘Aim To synthesize isonucleoside-incorporated oligonucleotides and investigatetheir binding abilities with complementary sequences. Methods The synthesis was performed on DNAsynthesizer, and the binding behavior was investigated by thermal denaturation studies. Results Fourkinds of single isonucleoside containing oligonucleotides were synthesized. The results of thermaldenaturation showed that the existence of isonucleoside decreased the stability of duplex, and theeffect was more obvious when the isonucleoside was in the middle of the sequence. No obviousdifference was observed when 6'-OH of isonucleoside was free or was protected by allyl group.Conclusions The existence of isonucleoside in oli-gonucleotide makes chain twist and decreased thestability of duplex.
基金supported by Department of Animal Resource & Science,Dankook University
文摘Background： Dietary nucleotides, considered as antibiotics alternative, were shown to have positive effects on intestinal hyperaemia, systemic immunity, small-intestinal growth, and hepatic composition in pigs. However, there is no previous research on nucleotide supplementation in weanling pigs under an oral challenged E. coil K88. Therefore, 2 experiments were conducted to investigate the effects of dietary nucleotides on weanling pig growth performance, nutrient digestibility, fecal score, and blood profile after being orally challenged with E. coli K88. Methods： In Exp. 1, a total of 140 weanling pigs [8.33 ± 0.33 kg of body weight （BW）, 28-d old] were used in this 42-d feeding trial. Pigs were distributed into 1 of 4 treatments, 5 pigs/pen （3 barrows and 2 gilts） and 7 pens/treatment. Treatments were a control basal diet （CON） or the CON supplemented with 150 （R150）, 220 （R220）, or 275 （R275） mg/kg to give the three treatment diets. In Exp. 2, 28 weanling pigs （BW = 8.40 ± 0.22 kg, 28-d old） were distributed into 1 of 4 treatments to give 1 pig/pen and 7 pens/treatment in a 42-d feeding and challenge trial. Dietary treatments were the same as in Exp. 1. 0n d 14, all those pigs （BW= 13.3±0.15 kg, 42-d old） were orally dosed with 1.5 mL suspension containing 10 cfu/mL of E. coli K88. Twenty four hours after challenge, blood and excreta samples were collected from each pigs for analysis. Fecal scores were measured on d 7, 14, 21, and 28 of the study. Results： In Exp. 1, overall BW, average daily gain （ADG）, gain/feed （G/F） ratio, and nutrient digestibilities were lower （P 〈 0.05） in CON group compared with the nucleotides fed pigs. In Exp. 2, after challenge, IgA, IgM, and IGF-I were higher （P〈 0.05） in the nucleotide groups compared with CON. However, the nucleotide groups had lower （P 〈 0.05） cortisol and TNF-o compared with CON. Fecal E. coil counts and fecal score for the nucleotide groups were lower （P 〈 0.05） than for CON. Conclusions： In conclusion, dietary nucleotides supplementation could improve growth performance, nutrient digestibility, immune status, microbial balance, reduce diarrhea, and provide protection against enterotoxigenic E. coli K88 infection in weanling pigs.
文摘Nucleotides (NT) and human milk oligosaccharides (HMO) individually affect epithelial cell growth, but their combined effects had not been studied. Herein, the impact of NT and HMO on cell proliferation, apoptosis, necrosis and cell cycle in the fetal epithelial cell line (FHs-74 Int) was determined. Cells were incubated with media containing 2.5% FBS and no epidermal growth factor (Control);fucosyllactose (FL) mix [85% 2’FL/15% 3’FL], sialyllactose (SL) mix [40% 6’SL/10% 3’SL/50% sialic acid (SA)] or LNnT at 125, 250, 500 or 1000 μg/mL with and without 250 μg/mL NT (43% CMP, 18.5% UMP, 16.4% AMP, and 22.0% GMP) for 24 or 72 h. NT alone significantly increased proliferation, but did not affect cell cycle or apoptosis/necrosis. All HMO treatments at 1000 μg/mL significantly decreased proliferation and some were also inhibitory at 250 or 500 μg/mL. When NT and HMO were simultaneously added, NT ameliorated the anti-proliferative effect of HMO. FL significantly increased cells in S phase and SL and LNnT treatments significantly increased cells in G2/M and S phases, which concomitantly decreased cells in G0/G1. HMO with NT significantly decreased the percent of cells in the G2/M phase compared to HMO alone. Higher HMO doses significantly increased the percentage of apoptotic and necrotic cells compared to control. In conclusion, HMO reduced cell proliferation and this effect is partially ameliorated by NT. It appears that HMO initially induced apoptosis/necrosis, which was later evidenced by G2/M cell cycle arrest and decreased proliferation.
文摘We measured the erythrocyte levels of principal nucleotides (ATP, ADP, AMP, GTP, GDP, GMP, IMP), nucleosides (Ado, Guo, Ino) and Hyp with HPLC. Purine concentrations were determined in the erythrocytes of 36 type 1 and 40 type 2 diabetic patients. The increased dephosphorylation of adenine and guanine nucleotides, indicated by increased Ado, Ino, Guo and Hyp concentrations as the products of purine nucleotide degradation, suggests serious energy metabolism disruptions in diabetes. An increase in AMP, GMP, IMP concentrations, as well as a decrease in AEC and GEC values, points to significant alterations in erythrocyte purine nucleotide concentration.
文摘The present work revealed that the praseodymium()complex of 2carboxyethylgermanium sesquioxide(Ge132)promotes the hydrolysis of the phosphodiester linkages of 3,5cyclic adenosine monophosphate(cAMP),3,5cyclic deoxyadenosine monophosphate(dcAMP),5adenosine monophosphate(5AMP)and 5deoxyadenosine monophosphate(5dAMP)under mild conditions.Both cAMP and dcAMP were hydrolyzed sitespecifically,yielding predominantly 3monophosphates,the main products of the cleavage of 5AMP and 5dAMP included adenosine(Ado),deoxyadenosine(dAdo)and free phosphates respectively.A hydrolytic mechanism was proposed for cAMP,dcAMP,5AMP and 5dAMP.
文摘At present, there is no method for identifying meat frozen in a thermal state acceptable for production control. The role of free nucleotides in the processes of refrigeration and storage of meat, affecting the structural and mechanical properties of muscle tissue, the formation of taste and its biological value is known. In this article we compared methods for identifying the thermal state of meat based on the determination of the composition and content of free nucleotides by high-performance liquid chromatography (HPLC) and spectrophotometry [SF]. High-purity reference substances were used: free nucleotides—ATP, ADP, AMP, IMP and nucleosides-inosine and hypoxanthine. It has been experimentally established that the characteristic peaks of the absorption spectra for extracts of free nucleotides of meat frozen depended from thermal state of meat. The content of ATP is 21.8 times higher in meat frozen in a fresh state, and the amount of IMF is 12.3 times lower than in meat frozen after cooling. The results of studies of meat frozen using the HPLC method and the developed SF method show the adequacy of the data obtained by both methods. SF-method based on the determination of the optical density of the extracts of free nucleotides is recommended to justify the choice of technological process meat defrost modes.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20173023 and No.90203012） and the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘Zipf＇s approach in linguistics is utilized to analyze the statistical features of frequency and correlation of 16 nearest neighboring nucleotides （AA, AC, AG, …, TT） in 12 human chro- mosomes （Y, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, and 12）. It is found that these statistical features of nearest neighboring nucleotides in human genome： （i） the frequency distribution is a linear function, and （ii） the correlation distribution is an inverse function. The coefficients of the linear function and inverse function depend on the GC content. It proposes the correlation distribution of nearest neighboring nucleotides for the first time and extends the descriptor about nearest neighboring nueleotides.
文摘A new version of DNA walks, where nucleotides are regarded unequal in their contribution to a walk is introduced, which allows us to study thoroughly the “fine structure” of nucleotide sequences. The approach is based on the assumption that nucleotides have an inner abstract characteristic, the determinative degree, which reflects genetic code phenomenological prop-erties and is adjusted to nucleotides physical properties. We consider each codon position independently, which gives three separate walks characterized by different angles and lengths, and that such an object is called triander which reflects the “strength” of branch. A general method for identifying DNA sequence “by triander” which can be treated as a unique “genogram” (or “gene passport”) is proposed. The two- and three-dimensional trianders are considered. The difference of sequences fine structure in genes and the intergenic space is shown. A clear triplet signal in coding sequences was found which is absent in the intergenic space and is independent from the sequence length. This paper presents the topological classification of trianders which can allow us to provide a detailed working out signatures of functionally different genomic regions.
基金the National Natural Science Foundation of China(Nos.22122108 and 21971208)the Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province of China(No.2021JC-37)the Fok Ying Tong Education Foundation(No.171010).
文摘The development of molecular probes or systems with the ability of multiple orthogonal responses is an effective approach to precisely detect biomolecules with similar chemical structures.Herein,we report the synthesis of a water-soluble TPE-based octacationic cage(1)with the compressed TPE-containing bilayer,which endows it with good fluorescence properties and potential conformation chirality.As a result,1 exhibits molecular recognition for anionic nucleotides within its two“claw”-like cavities to form 1:2 host-vip complexes in water,companying with selective turn-off fluorescence and turn-on CD responses to G/GTP over other nucleotides.
文摘We investigate the possibility of injection of a nucleotide via single-walled carbon nanotubes (SWNTs). The collapse process of an SWNT with a large radius may proceed like falling dominoes. The characteristics of a large radius SWNT are utilized to drive the nucleotide movement in the SWNT, or even to inject the stored nucleotide out of the SWNT. In this process, the lateral section of the collapsed SWNT resembles a dumbbell. Occasionally, the nucleotide in the SWNT will be inbreathed into one of the two dumbbell ends, leading to interference with the injection process. To investigate the random nature of the injection process, a series of simulations on SWNT with different lengths were carried out. It was found that the injection probability was not influenced by the tube length. Freezing the nucleotide at the beginning, or modifying the SWNT at the outlet, may serve to facilitate the injection process, as indicated by the rise in the injection probability.
基金Zhejiang Provincial Natural Science Foundation of China(Nos.LR24B020003 and LQ24B020003)Science and Technology Project of Taizhou City(No.24gyb17)for financial support。
文摘New water-soluble fluorescent tetracationic imidazolium-based macrocycles are synthesized via a modular SN2 nucleophilic substitution reaction.The positive charge and acidic C-H sites of these macrocycles enable them to bind with nucleotides in water,driven by hydrogen bonds and electrostatic interactions.The binding is high affinity for suitable nucleotides.These properties position them as promising candidates for the selective sensing of nucleotides.
基金supported by grants from the National Science and Technology Support Program Project of China (2014CB138600, 2012BAD25B02, 2015CB150605)the National Natural Science Foundation of China (31272672 to ZGZ)the Beijing Earmarked Fund for Modern Agro-industry Technology Research System (SCGWZJ20141104-4)
文摘This study investigated the effect of dietary supplementation of yeast nucleotides on the growth, nonspecific immunity, intestine growth and intestinal microbiota of juvenile hybrid tilapia. Tilapia(initial average weight of 8.02 g) was fed test diets supplemented with a yeast-originated nucleotide mixture(0,0.15, 0.30, 0.60, and 1.20 g/100 g diet) for 8 weeks. Fish fed the diet with 0.60% nucleotide had significantly higher weight gain than the control group(P < 0.05). Feed efficiency was improved in the fish fed 0.60 and 1.20% nucleotide compared with that in the control group. The optimal doses of nucleotides supplementation for growth and feed efficiency of fish were determined as 0.63 and 0.81%, respectively.Intestinal growth was improved in the 0.30 and 0.60% groups, as indicated by significant increase in intestine length. The fish fed 0.60 and 1.20% nucleotide showed higher super oxide dismutase(SOD)activity and lower malondialdehyde(MDA) level in the liver than the control fish, indicating enhancement of the anti-oxidant status. Serum lysozyme activity was significantly increased in the 0.15 and 0.3%nucleotide supplementation groups, suggesting an enhancement effect on the non-specific immune response. Lastly, dietary nucleotides supplementation exerted moderate influence on the intestinal microbiota of hybrid tilapia. A reduction in the cumulative abundance of putative butyrate-producing species was observed in the intestinal microbiota of fish fed diets with 0.60% nucleotide compared with the control, implying an interaction between dietary nucleotides and butyrate production. Briefly, dietary supplementation with 0.60% nucleotide improve the growth performance, immune activity and intestine growth in tilapia.
基金support of Natural Science Foundation of Liaoning Province(No.201102210)Program for Liaoning Innovative Research Team in University(No.LH2012018)National Undergraduate Training Programs for Innovation and Entrepreneurship(No.201210163007).
文摘Cancer,like other diseases accompanied by metabolic changes,shows characteristic DNA/RNA modifications and activities of modifying enzymes,resulting in fluctuations in nucleoside levels.In this study,we undertook targeted metabolomic analyses of nucleotides in different cancer cell culture models using a sensitive and reproducible ion-pair HPLC method.The experimental data were analyzed by principal component analysis(PCA)to identify potential biomarkers in cancer cells,and statistical significance was determined by one-way analysis of variance.As a result,a clear differentiation of normal and tumor cells into two clusters was shown,indicating abnormal metabolism of nucleotides in tumor cells.Six variables(AMP,UDP,CTP levels with a significance of Po0.05;ATP,UTP and GMP levels with a significance of Po0.01)were considered as potential biomarkers;the content of AMP,UTP,GMP and ATP was significantly higher in cancer cells.The receiver operating characteristic(ROC)curve analysis allowed us to discriminate normal cells from tumor cells based on area under the curve(AUC).The sequence of their AUC values were:ATP(0.979)4UTP(0.938)4CTP¼GMP(0.896)4AMP(0.812)4UDP(0.792),so we conclude that ATP and UTP are the best potential biomarkers in tumor cells.This study may provide a valuable tool for studying minute alterations of intracellular nucleotide pools induced by anticancer/antiviral drugs,diseases or environmental factors.
文摘Objective:To observe the effect of electroacupuncture(EA)pretreatment on adenine nucleotides in the myocardial tissues of the myocardial ischemia-reperfusion injury(MIRI)rats,and to explore the mechanism of EA pretreatment on myocardial prevention and protection in MIRI rats.Methods:Forty SPF male Sprague-Dawley(SD)rats were randomly divided into 5 groups:a blank group,a sham operation group,a model group,an EA at Neiguan(PC 6)group and an EA at Hegu(LI 4)group,with 8 rats in each group.Rats in the blank group only received binding to the rat plate,30 min/time,once a day for 7 d;on the 7th day,rats in the sham operation group were subjected to threading for 40 min at the left anterior descending coronary artery without ligation,and then the rats were allowed to stand for 60 min before collection of the specimens;on the 7th day,rats in the model group were subjected to threading at the left anterior descending coronary artery with ligation,for 40 min before the blood flow was restored,and then the rats were allowed to stand for 60 min before collection of the specimens;on the 7th day of pretreatment with EA at Neiguan(PC 6)or Hegu(LI 4)for 30 min per day(once a day for 7 d),rats in the EA at Neiguan(PC 6)group and EA at Hegu(LI 4)group were subjected to modeling and sample collection same as in the model group.The left ventricular myocardium of the lower left anterior descending coronary artery was collected from rats in all 5 groups.Hematoxylin-eosin(HE)staining and transmission electron microscope(TEM)were used to observe the changes in myocardial pathological morphology.The change in the adenine nucleotide level of myocardial tissue was measured by high performance liquid chromatography(HPLC).Results:The HE staining and ultrastructure showed that the myocardial injury was severer in the model group compared with the sham operation group.Compared with the model group,the myocardial injury in the EA at Neiguan(PC 6)and the EA at Hegu(LI 4)groups was mild or hardly any.The adenine nucleotide levels in the sham operation group and the model group were all decreased compared with the blank group(all P<0.05);compared with the sham operation group,the adenine nucleotide level of the model group was also decreased,but the difference was not statistically significant(P>0.05);compared with the model group,the adenine nucleotide level in the EA at Neiguan(PC 6)group was increased(P<0.05),and the adenine nucleotide level in the EA at Hegu(LI 4)group was significantly increased(P<0.01).The adenine nucleotide level in the EA at Hegu(LI 4)group was higher than that in the EA at Neiguan(PC 6)group,but the difference was not statistically significant(P>0.05).Compared with the EA at Neiguan(PC 6)group,the levels of adenosine triphosphate(ATP),adenosine diphosphate(ADP)and adenosine monophosphate(AMP)in the EA at Hegu(LI 4)group were significantly increased(all P<0.01).Conclusion:Both EA at Neiguan(PC 6)and Hegu(LI 4)can alleviate the pathological damage to myocardium in MIRI rats,and increase the adenine nucleotide level in myocardial tissues,and thus protect MIRI rats.EA at Hegu(LI 4)has a better protective effect than Neiguan(PC 6).
基金Project supported by the National Natural Science Foundation of China. Part Ⅱ of this series is Ref. [3].
文摘A thirty-nine nucleotide fragment (nucleotides 38—76) of yeast alanyl tRNA was prepared by using calf spleen phosphodiesterase to delete C_(36)m^1I_(37) from the 3′-half molecule of this tRNA under controlled conditions. Analogs of yeast alanyl tRNA with A, G or C instead of m^1I_(37) were synthesized and their biological activities determined. The results indicated that the aminoacylation activity of these analogs was not affected in the rat liver aminoacyl-tRNA synthetase system, compared with natural yeast alanyl tRNA. However, the incorporation activity (i. e. the activity of transferring alanine into proteins) of these analogs was significantly reduced to 20—30% of that of natural yeast alanyl tRNA in the rabbit reticulocyte lysate cell-free protein synthesizing system.
基金by the National Natural Science Foundation of China(30772763)Innovation Team Development Plan of the Ministry of Education of China(IRT0810)Program for New Century Excellent Talents of the Ministry of Education of China(2010)。
文摘Acting as immune cells,microglia play a surveillance role in central nervous system injuries and diseases.Extracellular nucleotides such as ATP and UTP,and adenosine are reported to regulate the response of microglia to insults and disease.ATP activates P2X receptors and triggers several signal cascades,resulting in the activation of microglia.Subsequently,UDP binding to the P2Y6 receptor induces phagocytosis by microglia,while adenosine regulates process retraction in microglia.Nucleotides and adenosine leak out from dead cells and act on their corresponding receptors on microglia,stimulating the release of inflammatory factors and cytokines to provide both neurotrophic and neurotoxic effects.In this article,we review the regulatory effects of nucleotides and adenosine on microglial chemotaxis,phagocytosis,and process retraction,and summarize the activities of these cells after ischemia.
基金Project supported by the National Natural Science Foundation of China.
文摘The 3' half molecule of yeast tRNAAla (nucleotides 36-75) was hybridized with a DNA fragment (5'GGAATCGAACC 3') and the hybrid was then digested with E. coli RNase H (from Boehringer). The enzyme can specifically cleave the 3' half molecule at the 3' side of nucleotide ψ55, thus a fragment C36-ψ55 was prepared. The 3'-terminal T or Tψ of this fragment was removed by one or two cycles of periodate oxidation and $-elimination. The products were fragments C36-T54 and C36-G53. Three yeast tRNAAla fragments C56-A76, U55-A76 (with ψ55 replaced by U), U54-A76 (with T54ψ55 replaced by UU) were synthesized and ligated with three prepared fragments (C36-ψ55 C36-T54 and C36-G53) respectively by T4 RNA ligase. The products were further ligated with the 5' half molecule (nu-cleotides 1-35). Using this method, one reconstituted yeast tRNAAla (tRNAr) and two yeast tRNAAla analogs: (i) tRNAa with U55 instead of ψ55; (ii) tRNAb with U54U55 instead of T54ψ55 were synthesized. The charging and incorporation activities of these three tRNAs were determined. In comparison with the reconstituted tRNA, the charging activity was 75% for tRNAa and 45% for tRNAb and the incorporation activity was 65% for tRNAa and 70% for tRNAb. These results suggest that the modified nucleotides T54 and ψ55 play an important role in yeast tRNAAla func-tion.
文摘Holley et al. were the first in 1965 to determine the primary sequence of a nucleic acid—yeast alanine transfer RNA. This molecule consists of 76 nucleotides, including 7 different modified nucleotides as further investigated by other
