Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulat...Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood−brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.展开更多
BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is o...BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE: To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN : A randomized control animal experiment SETTING : Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS: Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS: The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups: control group (n=10), alcohol group (n=10) and topiramate-treated group (n=10). Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol (10 mL/kg), once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy (HPLC) respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES : ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS: Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group (10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01). In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol (6.06±0.82, 3.50±0.92, P 〈 0.05), and the withdrawal scores at 48 and 72 hours were close to those in the control group (4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05).② Changes of the contents of glutamic acid in hippocampal dentate gyrus: In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [(143.32±11.42)%, (99.12±0.69)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(78.50±16.40)%, (99.12±0.69)%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.30±0.37)%, (118.91±10.40)%, (99.55±12.81)%, (99.08±11.42)%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus: In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [(126.60±8.67)%, (129.17±10.40)%, (99.25±0.87)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(89.87±9.93)%, (99.25±0.87)%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.27±0.32)%, (120.81 ±12.63)%, (98.91±7.83)%, (85.92±8.07)%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). CONCLUSION: ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats.展开更多
Objective:To estimate to what extent the mixture of ursolic acid and oleanolic acid,in addition to the antitubercular standard regime,affects the hepatotoxicity profile.Methods:Liver injury was induced in male BALB/c ...Objective:To estimate to what extent the mixture of ursolic acid and oleanolic acid,in addition to the antitubercular standard regime,affects the hepatotoxicity profile.Methods:Liver injury was induced in male BALB/c mice by administering,per os and daily for 11 weeks,a combination of anti-Tubercular(anti-TB) agents Rifampicin(10 mg/kg),Isoniazid(10 mg/kg),and Pyrazinamide(30 mg/kg).The ursolic acid and oleanolic acid mixture at doses of 100 or 200 μg/mouse/day was subcutaneously injected throughout the entire study period(11 weeks).Biochemical and hematological analysis was supplemented by liver histological examination.Results:Animals treated with the mixture of triterpenic acids exhibited significantly decreased aspartate transaminase and alanine aminotransferase levels and amelioration of the histopathological alterations produced by the anti-TB drugs.Conclusions:The triterpene mixture is able to prevent the steatosis induced by the anti-TB drugs.展开更多
The present study collected cerebrospinal fluid samples from the corpus striatum in rats treated with borneol, moschus, storax, and acorus tatarinowii using brain microdialysis technology. Levels of excitatory neurotr...The present study collected cerebrospinal fluid samples from the corpus striatum in rats treated with borneol, moschus, storax, and acorus tatarinowii using brain microdialysis technology. Levels of excitatory neurotransmitters aspartic acid and glutamate, as well as inhibitory neurotransmitters glycine and ^-aminobutyric acid, were measured in samples using reversed-phase high-performance liquid chromatography, phosphate gradient elution, and fluorescence detection. Results showed that concentrations of all four amino acid neurotransmitters significantly increased in the corpus striatum following treatment with borneol or moschus, but effects due to borneol were more significant than moschus. Acorus tatarinowii treatment increased ^-aminobutyric acid expression, but decreased glutamate concentrations. Storax increased aspartic acid concentrations and decreased glycine expression. Results demonstrated that borneol and moschus exhibited significant effects on con amino acid neurotransmitter expression; storax exhibited excitatory effects and acorus tatarinowii resulted in inhibitory effects.展开更多
Amino acid transporters,which play a vital role in transporting amino acids for the biosynthesis of mammalian cells,are highly expressed in types of tumors.Increasing studies have shown the feasibility of amino acid t...Amino acid transporters,which play a vital role in transporting amino acids for the biosynthesis of mammalian cells,are highly expressed in types of tumors.Increasing studies have shown the feasibility of amino acid transporters as a component of tumortargeting therapy.In this review,we focus on tumor-related amino acid transporters and their potential use in tumor-targeting therapy.Firstly,the expression characteristics of amino acid transporters in cancer and their relationship with tumor growth are reviewed.Secondly,the recognition requirements are discussed,focusing on the“acidbase”properties,conformational isomerism and structural analogues.Finally,recent developments in amino acid transporter-targeting drug delivery strategies are highlighted,including prodrugs and nanocarriers,with special attention to the latest findings of molecular mechanisms and targeting efficiency of transporter-mediated endocytosis.We aim to offer related clues that might lead to valuable tumor-targeting strategies by the utilization of amino acid transporters.展开更多
The stability constants and thermodynamic functions for complexes of lanthanum with eight kind of amino acids according to 1∶1 and 1∶2 in proportion have been determined by titration calorimeter at 298.15 K. The ent...The stability constants and thermodynamic functions for complexes of lanthanum with eight kind of amino acids according to 1∶1 and 1∶2 in proportion have been determined by titration calorimeter at 298.15 K. The enthalpy change makes a predominant contribution to the stability of these complexes. The ring in amino acid associated with lanthanum ion helps to enhance the stability of complexes. Steric effects between rings in complexes leads to that the equilibrium constants of reaction of the complexes (1∶2) is much less than that of the complexes (1∶1).展开更多
Amino acids are the building blocks of proteins,which are the most abundant macromolecules in living cells.From the standpoint of the photon interaction cross sections of amino acids,the mass attenuation coefficients,...Amino acids are the building blocks of proteins,which are the most abundant macromolecules in living cells.From the standpoint of the photon interaction cross sections of amino acids,the mass attenuation coefficients,half and tenth value layers,mean free path,effective atomic and electronic cross sections,effective atomic number,and effective electron density of fifteen essential amino acids have been determined for 133Ba,137Cs,and 60Co gamma-ray sources.The MCNP-4C code and the XCOM program have been used to calculate these parameters.The results have been compared to the available experimental and theoretical data.The theoretical results agreed with the experimental data,with RD values of ≤±7%.In the energy region of 81-1332.5 keV,it was found that the μm,σa,and revalues of the amino acids decreased as the photon energy increased,and the increasing density of amino acids had no steady effect on these quantities.Additionally,results demonstrated that the HVL,TVL,and MFP values increased with the increase in photon energy.The μm,σa,and Zeff values of aspartic acid were the highest among those of all amino acids,and they were the lowest for isoleucine.The Zeff value of each sample containing H,C,N,and O atoms was nearly constant in the studied energy region.The Neffvalues of the studied amino acids varied in the range of 3.14×10^23-3.44×10^23 electron/g.Furthermore,the Neffvalues were approximately independent of the amino acid type in this energy region.展开更多
A new six intraperitoneal injection insulin-mimetic vanadyl(Ⅱ) compounds [(VD3^-1)(VO^+2)(AAn^-1)](where(n=1~6);AA1=isoleucine, AA2=threonine, AA3=proline, AA4=phenylalanine, AA5=lysine and AA6=glutamine) were synthe...A new six intraperitoneal injection insulin-mimetic vanadyl(Ⅱ) compounds [(VD3^-1)(VO^+2)(AAn^-1)](where(n=1~6);AA1=isoleucine, AA2=threonine, AA3=proline, AA4=phenylalanine, AA5=lysine and AA6=glutamine) were synthesized by the chemical reactions between vitamin D3(VD3), VOSO4 and amino acids(AAn) with equal molar ratio 1∶1∶1 in neutralized media. The structures of these complexes were elucidated by spectroscopic methods like, infrared and solid reflectance spectroscopes. Magnetic moments and electronic spectra reveal square pyramid geometrical structure of the complexes. The infrared spectra assignments of these complexes revealed that the chelation towards vanadyl(Ⅳ) ions existed via deprotonation of the hydroxyl group of VD3 drug ligand and so amino acids act as bidentate ligand via N-amino and O-carboxylate groups. The anti-diabetic efficiency of these complexes were evaluated against streptozotocin induced diabetic male albino rats.展开更多
It is worthy to mention that the two broad bean cultivars displayed a surprising situation during the fruiting stage of growth. The absolute amount of pods yield was higher in cv. Assiut 125 than in cv. Assiut 84. Thi...It is worthy to mention that the two broad bean cultivars displayed a surprising situation during the fruiting stage of growth. The absolute amount of pods yield was higher in cv. Assiut 125 than in cv. Assiut 84. This situation was in contrast with that in the vegetative stage, where cv. Assiut 84 produced greater vegetative growth than cv. Assiut 125. Although the cv. Assiut 84 was less affected by the highest dose of copper, the cv. Assiut 125 was greatly affected by this dose. However, another surprising situation was recorded when the absolute values of fresh and dry matter of cv. Assiut 125 were much higher than cv. Assiut 84 at any used copper concentration. The fresh matters of the pods of cv. Assiut 84 and cv. Assiut 125 were 7.24 and 10.16 gm at the level of control and 6.69 and 7.59 gm at the level of 350 ppm Cu, respectively. Their dry matters were 1.99 and 3.52 gm at the level of control and 1.77 and 2.13 gm at the level of 350 ppm Cu2+ in cv. Assiut 84 and cv. Assiut 125, respectively. This contradiction was also extended when these copper-affected cultivars were sprayed by IAA. The cv. Assiut 84 responded slightly to IAA treatment. On the other hand, a considerable increase in the dry matter yield was recorded in the pods of cv. Assiut 125 at any used level of copper when compared to the non-sprayed plants treated by the same copper concentration. At the level of 350 ppm Cu2+ , the pod yield was 2-fold that of plants treated only by 350 ppm Cu2+ , without IAA spraying. Thus, even IAA behaved differently in its effect on the crop yield of the two tested broad bean cultivars. There are big and surprising variations in the accumulation of microelements and heavy metals in pods among the two broad bean genotypes, whatever the treatments used. These variations seemed to be complicated which might need further studies. The concentration of amino acids and their individuals also varied among the two cultivars;they increased in cv. Assiut 84 and decreased in cv. Assiut 125. The increased amino acids in cv. Assiut 84 are mostly used as precursors for phytochelatins. For the previous studies, thus the present work was conducted to explain the effect of Cu and interactive effect with IAA on two selected broad bean cultivars Assiut 84 and Assiut 125 during yielding production.展开更多
The effect of ethanol on the transport of amino acids across the human placenta was studied in the dual perfusion apparatus using a non-metabolizable α-amino isobutyric acid (AIB). Results were obtained for thirty in...The effect of ethanol on the transport of amino acids across the human placenta was studied in the dual perfusion apparatus using a non-metabolizable α-amino isobutyric acid (AIB). Results were obtained for thirty intact whole human placentas in the absence (control group) and presence (ethanol group) of ethanol (500 - 1000 mg/dL). Experimental determinations of AIB transport at AIB concentrations of 5 - 100 mg/l, measured radioactively using (1−14 C-) AIB, were compared with a dual-active transport model. The diffusion coefficients of AIB were found to be (3.7 × 10−9 cm2/s) in the absence of ethanol and (2.3 × 10−9 cm2/s) in the presence of ethanol with no statistical difference (P = 0.25). The ratio of the fetal to maternal perfusate concentrations in the absence of ethanol (1.44) was statistically significant (P = 0.016) from the ratio in the presence of ethanol (1.20), which may indicate that active transport in the human placenta is inhibited by the presence of ethanol. The placental uptake from the maternal circulation was 2.6 (control) and 2.5 (ethanol) times greater than the uptake from the total circulation. The relative contribution of the diffusive transport to the net placental uptake of AIB from both the maternal and fetal circulations was less than that of active transport regardless of the presence of ethanol: control (38%) and ethanol (35%). It appears that the placental tissue plays the role of a mediator to maintain a fetal concentration higher than the maternal one by either enhancing the transfer from the maternal to the placental tissue or impairing the transfer in the opposite direction.展开更多
BACKGROUND: Nitric oxide synthase (NOS) inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate t...BACKGROUND: Nitric oxide synthase (NOS) inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate the ischemic neuronal damage with the release of excessively excitatory amino acids (EAA) during cerebral ischemia. On the other hand, some inhibitory amino acid is suggested to be important for the neuronal protection against ischemic brain damage. Our study has recently showed that treatment with the NOS inhibitor NG-nitro-L-arginine (L-NA) reduced focal cerebral ischemic damage. The effect of L-NA on the contents of excitatory and inhibitory amino acid in the rat brain following cerebral ischemia is still unclear. OBJECTIVE: By evaluating the effect of NOS inhibitor, L-NA on the contents of aspartate, glutamate, glycine and γ-aminobutyric acid (GABA) in striatum, hippocampus and cortex in the rat brain following cerebral ischemia respectively, to investigate the beneficial effect of L-NA on cerebral ischemic injury and the possible mechanism. DESIGN: A randomized and controlled experiment SETTING : Department of Pharmacology, Hebei Academy of Medical Sciences MATERIALS: A total of 42 male healthy SD rats (grade Ⅱ, weighting 250-300 g) were provided by the Experimental Animal Center of Hebei Province (Certification: 04036). Aspartate, glutamate, glycine, GABA, L-NA and 2,3,5-triphenyltetrazolium chloride (TTC) were obtained from Sigma Chemicals Co, St Louis, MO, USA. HPLC-ultraviolet detector system consisted of Agilent 1100 HPLC. METHODS: The experiment was carried out in Department of Pharmrcology, Hebei Academy of Medical Sciences from June 2005 to June 2006. Rats were randomly divided into three groups: sham-operated group (n = 6), ischemic group (n = 18), L-NA group (n = 18). The model of focal cerebral ischemia in rat was prepared with intraluminal line occlusion methods. In sham-operated rats, the external carotid artery was surgically prepared, but the filament was not inserted. Each group was further divided into 3 subgroups (n = 6 for each): drugs were administrated at 2, 6 and 12 hours after the middle cerebral artery occlusion (MCAO) respectively. L-NA (20 mg/kg, ip) was administrated, twice a day, for 3 consecutive days. Same volume of normal saline was administrated in ischemic and sham operation groups. The changes of infarcted volume and the contents of amino acids were respectively assayed. Image analysis software was used for the measurement of the infarcted area. The results were expressed as a percentage of the infarcted volume of cerebral/volume of whole brain (IV%) in order to control for edema formation. The contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in the rat brain following cerebral ischemia were respectively measured by HPLC method. All data were analyzed with one-way ANOVA and Dunnett's test. MAIN OUTCOME MEASURES: (1) The volume of cerebral infarction; (2) The contents of aspartate, glutamate glycine and GABA in brain tissue after cerebral ischemia. RESULTS : All 42 rats were involved in the final analysis. (1) Infarcted volume: Volume was 0 in sham-operated group. When L-NA was administrated at 2 and 6 hours after MCAO, the infarcted volume was (20.13±3.59)% and (23.12±5.84)% in L-NA group, which was not similar to that in ischemic group [(22.10±3.98)%, (25.38± 5.37)%, P〉 0.05]. However, the infarcted volume was markedly decreased compared with that of ischemic group when L-NA was administrated at 12 hours after MCAO [(26.11±3.55)% and (37.15±3.58)%, P 〈 0.01]. Changes of amino acid content: At 2 and 6 hours after ischemia, the contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in ischemic group were significantly increased compared with those in sham-operated group ( P〈 0.05-0.01). However, contents in L-NA group were similar to those in ischemic group (P 〉 0.05). At 12 hours after ischemia, the contents of aspartate [(0.21 ±0.06), (0.36±0.05), (0.29±0.12) mg/g] and glutamate [(0.55±0.06), (0.78±0.10), (0.52±0.10) mg/g] in striatum, hippocampus and cortex in L-NA group were significantly decreased compared with those in ischemic group [(0.49±0.17), (0.63± 0.03), (0.51±0.15) mg/g; (0.98±0.30), (1.15±0.15), (0.93±0.15) mg/g, P〈 0.05-0.01]. Glycine in hippocampus was (0.40±0.07) mg/g, which was higher than that in ischemic group [(0.21±0.07) mg/g, P 〈 0.05]. GABA in striatum, hippocampus and cortex was (0.93±0.10), (0.62±0.12) and (0.81 ±0.10) mg/g, respectively, which was higher than that in ischemic group [(0.60±0.08), (0.37±0.17), (0.59±0.10) mg/g, P 〈 0.05-0.01]. CONCLUSION : It may be concluded that L-NA have beneficial effect on ischemic cerebral injury in ischemic later stage in rats. The possible mechanism is that L-NA can decrease the contents of aspartate and glutamate, increase the contents of glycine and GABA.展开更多
The digestibility of cadmium(Cd)in brown rice is directly related to amino acid metabolism in rice and human health.In our field study,three kinds of alkaline calcium-rich soil inorganic amendments(SIAs)at three dosag...The digestibility of cadmium(Cd)in brown rice is directly related to amino acid metabolism in rice and human health.In our field study,three kinds of alkaline calcium-rich soil inorganic amendments(SIAs)at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated paddy.With the increased application of SIA,Cd content in iron plaque on rice root significantly increased,the transfer of Cd from rice root to grain significantly decreased,and then Cd content in brown rice decreased synchronously.The vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction test.Results showed that more than 70%of Cd in brown rice could be digested by simulated gastrointestinal juice.Based on the total and digestible Cd contents in brown rice to evaluate the health risk,the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy soils.The amino acids(AAs)in brown rice were determined by high-performance liquid chromatography.The contents of 5 key AAs(KAAs)that actively respond to environmental changes increased significantly with the increased application of SIA.The structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain,and consequently altered the ratio of indigestible Cd in brown rice.The formation of indigestible KAAs-Cd complexes by combining KAAs(phenylalanine,leucine,histidine,glutamine,and asparagine)with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd.展开更多
In this study,we have examined the effects of exposure to high temperature, carbon inonoxideor a combination of both conditions in a model system,the rat and in industrial workers.In the rat liver, HSP70 mRNA and HSP7...In this study,we have examined the effects of exposure to high temperature, carbon inonoxideor a combination of both conditions in a model system,the rat and in industrial workers.In the rat liver, HSP70 mRNA and HSP70 synthesis were measured by dot hybridization and western blot. The results showed that after a heat stress HSP70 mRNA and its product, HSP70 increased significantly and there was a synergism in the combined effects of high temperature and carbon monoxide exposure on the induction of HSP70 mRNA and HSP70 synthesis. Heat played a major role in this induction. The presence of antibodies to human HSP27, HSP60, HSP70,HSC73, HSP89 αand β in workers exposed to heat, carbon monoxide was also measured by western blot using purified HSPs as antigens. Plasma free amino acids were measured in the saine group of workers. The incidence of antibodies to HSP27 and HSP70 Was significantly higher in the workers working in an environment with extreme heat, and high carbon monoxide ernission than in a control group. The carbon monoxide exposed group showed the highest incidence of antibodies to HSPs. Although our previous results indicated that workers had an insufficient protein intake,plasma free amino acids tended to increase, especially in methionine and tryptophan two kinds of amino acids which are absent from the main stress protein, HSP70.These results suggest that the major problems that these workers may face are how to facilitate the use of plasma free amino acids and reduce the inhibition of synthesis of normal proteins when they are exposed to occupational harmful factors.These resultsalso add new information on the measurement of HSPs as a potential biomonitor to assess whether organisms are experiencing metabolic stress within their environment.展开更多
Cephalopods are important economic shellfish that have been developed extensively in the coastal water of various countries. Octopus vulgaris is a large-scaled economic cephalopod that is mainly cultured in South Chin...Cephalopods are important economic shellfish that have been developed extensively in the coastal water of various countries. Octopus vulgaris is a large-scaled economic cephalopod that is mainly cultured in South China. This study explored the effect of different diets on the volatile flavor and nutritional ingredients of O. vulgaris. Four diets were tested in four groups: Group A(fish(Scomberomorus niphonius)), Group B(crab(Helice tridens tientsinensis Rathbun)), Group C(clam(Mactra veneriformis)), and Group D(squid(Loligo japonica)). Octopus muscles were sampled after 36 days of feeding, and volatile flavor substances(VFSs), fatty acids(FAs), and amino acids(AAs) were detected. Results showed that the VFSs, FAs, and AAs of octopus in the four groups were obviously different. The sum of volatile ketones and aldehydes was higher in Group B than in the other groups, which could present much more flavors. All groups were abundant in unsaturated FAs, including eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA). In terms of content and variety, the FAs in Group B were more beneficial to human health than those in the other groups. The content of each AA in Group B was basically higher than those in the other groups and was significantly higher than that in Group D(P < 0.05). Comparing the VFSs, FAs, and AAs in samples fed with four kinds of diets, the results indicate that using crab to feed O. vulgaris can achieve better effects on volatile flavor and nutritional ingredients.展开更多
L-type amino acid transporters(LATs) mainly assist the uptake of neutral amino acids into cells. Four LATs(LAT1, LAT2, LAT3 and LAT4) have so far been identified. LAT1(SLC7A5) has been attracting much attention in the...L-type amino acid transporters(LATs) mainly assist the uptake of neutral amino acids into cells. Four LATs(LAT1, LAT2, LAT3 and LAT4) have so far been identified. LAT1(SLC7A5) has been attracting much attention in the field of cancer research since it is commonly up-regulated in various cancers. Basic research has made it increasingly clear that LAT1 plays a predominant role in malignancy. The functional significance of LAT1 in cancer and the potential therapeutic application of the features of LAT1 to cancer management are described in this review.展开更多
The nanohydroxyapatites (HAP) and its biological effects have been studied using ultraviolet absorption spectrum, X-ray diffraction (XRD) structure analysis, fluorescent and infrared spectrum of absorption and MTT met...The nanohydroxyapatites (HAP) and its biological effects have been studied using ultraviolet absorption spectrum, X-ray diffraction (XRD) structure analysis, fluorescent and infrared spectrum of absorption and MTT method. The nanohyd- roxyapatites are prepared and made by using Sol-gel method, in which the parameters of process and reaction are controlled as: PH 】9, Ca/P = 1.67, sintering temperature of 1100?C and sintering time 2 hours. The results of the study show that nanohydroxyapatites can absorb the amino acid molecules, the absorption is better for stronger acidity of amino acids. We also find that the nanohydroxyapatites and complex of nanoHAP+ nanoCrO2 can all restrain the proliferation of cells, but their toxiciteis are all first degree or minor, but the restrained effect of the latter is smaller than that of the former, although they can decrease the relative proliferation rate of cells. The nanohydroxyapatites can also change the molecular structure of human serum albumin.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U23A20591,52203201,52173149,and 81971174)the Youth Talents Promotion Project of Jilin Province(Grant No.202019)+1 种基金the Science and Technology Development Program of Jilin Province(Grant No.20210101114JC)Research Cooperation Platform Project of Sino-Japanese Friendship Hospital of Jilin University and Basic Medical School of Jilin University(Grant No.KYXZ2022JC04).
文摘Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood−brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.
文摘BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE: To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN : A randomized control animal experiment SETTING : Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS: Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS: The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups: control group (n=10), alcohol group (n=10) and topiramate-treated group (n=10). Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol (10 mL/kg), once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy (HPLC) respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES : ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS: Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group (10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01). In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol (6.06±0.82, 3.50±0.92, P 〈 0.05), and the withdrawal scores at 48 and 72 hours were close to those in the control group (4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05).② Changes of the contents of glutamic acid in hippocampal dentate gyrus: In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [(143.32±11.42)%, (99.12±0.69)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(78.50±16.40)%, (99.12±0.69)%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.30±0.37)%, (118.91±10.40)%, (99.55±12.81)%, (99.08±11.42)%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus: In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [(126.60±8.67)%, (129.17±10.40)%, (99.25±0.87)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(89.87±9.93)%, (99.25±0.87)%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.27±0.32)%, (120.81 ±12.63)%, (98.91±7.83)%, (85.92±8.07)%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). CONCLUSION: ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats.
基金partly supported by Grant from the Instituto Mexicano del Seguro Social (NO.FIS/IMSS/PROT/G12/1126FIS/IMSS/PROT/G14/1341)
文摘Objective:To estimate to what extent the mixture of ursolic acid and oleanolic acid,in addition to the antitubercular standard regime,affects the hepatotoxicity profile.Methods:Liver injury was induced in male BALB/c mice by administering,per os and daily for 11 weeks,a combination of anti-Tubercular(anti-TB) agents Rifampicin(10 mg/kg),Isoniazid(10 mg/kg),and Pyrazinamide(30 mg/kg).The ursolic acid and oleanolic acid mixture at doses of 100 or 200 μg/mouse/day was subcutaneously injected throughout the entire study period(11 weeks).Biochemical and hematological analysis was supplemented by liver histological examination.Results:Animals treated with the mixture of triterpenic acids exhibited significantly decreased aspartate transaminase and alanine aminotransferase levels and amelioration of the histopathological alterations produced by the anti-TB drugs.Conclusions:The triterpene mixture is able to prevent the steatosis induced by the anti-TB drugs.
基金supported by the National Natural Science Foundation of China, No. 81173572
文摘The present study collected cerebrospinal fluid samples from the corpus striatum in rats treated with borneol, moschus, storax, and acorus tatarinowii using brain microdialysis technology. Levels of excitatory neurotransmitters aspartic acid and glutamate, as well as inhibitory neurotransmitters glycine and ^-aminobutyric acid, were measured in samples using reversed-phase high-performance liquid chromatography, phosphate gradient elution, and fluorescence detection. Results showed that concentrations of all four amino acid neurotransmitters significantly increased in the corpus striatum following treatment with borneol or moschus, but effects due to borneol were more significant than moschus. Acorus tatarinowii treatment increased ^-aminobutyric acid expression, but decreased glutamate concentrations. Storax increased aspartic acid concentrations and decreased glycine expression. Results demonstrated that borneol and moschus exhibited significant effects on con amino acid neurotransmitter expression; storax exhibited excitatory effects and acorus tatarinowii resulted in inhibitory effects.
基金This work was supported by the National Natural Science Foundation of China(Nos.81803442 and 81703425).
文摘Amino acid transporters,which play a vital role in transporting amino acids for the biosynthesis of mammalian cells,are highly expressed in types of tumors.Increasing studies have shown the feasibility of amino acid transporters as a component of tumortargeting therapy.In this review,we focus on tumor-related amino acid transporters and their potential use in tumor-targeting therapy.Firstly,the expression characteristics of amino acid transporters in cancer and their relationship with tumor growth are reviewed.Secondly,the recognition requirements are discussed,focusing on the“acidbase”properties,conformational isomerism and structural analogues.Finally,recent developments in amino acid transporter-targeting drug delivery strategies are highlighted,including prodrugs and nanocarriers,with special attention to the latest findings of molecular mechanisms and targeting efficiency of transporter-mediated endocytosis.We aim to offer related clues that might lead to valuable tumor-targeting strategies by the utilization of amino acid transporters.
基金Supported by the National Nature Science Foundation of China(29873036)
文摘The stability constants and thermodynamic functions for complexes of lanthanum with eight kind of amino acids according to 1∶1 and 1∶2 in proportion have been determined by titration calorimeter at 298.15 K. The enthalpy change makes a predominant contribution to the stability of these complexes. The ring in amino acid associated with lanthanum ion helps to enhance the stability of complexes. Steric effects between rings in complexes leads to that the equilibrium constants of reaction of the complexes (1∶2) is much less than that of the complexes (1∶1).
文摘Amino acids are the building blocks of proteins,which are the most abundant macromolecules in living cells.From the standpoint of the photon interaction cross sections of amino acids,the mass attenuation coefficients,half and tenth value layers,mean free path,effective atomic and electronic cross sections,effective atomic number,and effective electron density of fifteen essential amino acids have been determined for 133Ba,137Cs,and 60Co gamma-ray sources.The MCNP-4C code and the XCOM program have been used to calculate these parameters.The results have been compared to the available experimental and theoretical data.The theoretical results agreed with the experimental data,with RD values of ≤±7%.In the energy region of 81-1332.5 keV,it was found that the μm,σa,and revalues of the amino acids decreased as the photon energy increased,and the increasing density of amino acids had no steady effect on these quantities.Additionally,results demonstrated that the HVL,TVL,and MFP values increased with the increase in photon energy.The μm,σa,and Zeff values of aspartic acid were the highest among those of all amino acids,and they were the lowest for isoleucine.The Zeff value of each sample containing H,C,N,and O atoms was nearly constant in the studied energy region.The Neffvalues of the studied amino acids varied in the range of 3.14×10^23-3.44×10^23 electron/g.Furthermore,the Neffvalues were approximately independent of the amino acid type in this energy region.
文摘A new six intraperitoneal injection insulin-mimetic vanadyl(Ⅱ) compounds [(VD3^-1)(VO^+2)(AAn^-1)](where(n=1~6);AA1=isoleucine, AA2=threonine, AA3=proline, AA4=phenylalanine, AA5=lysine and AA6=glutamine) were synthesized by the chemical reactions between vitamin D3(VD3), VOSO4 and amino acids(AAn) with equal molar ratio 1∶1∶1 in neutralized media. The structures of these complexes were elucidated by spectroscopic methods like, infrared and solid reflectance spectroscopes. Magnetic moments and electronic spectra reveal square pyramid geometrical structure of the complexes. The infrared spectra assignments of these complexes revealed that the chelation towards vanadyl(Ⅳ) ions existed via deprotonation of the hydroxyl group of VD3 drug ligand and so amino acids act as bidentate ligand via N-amino and O-carboxylate groups. The anti-diabetic efficiency of these complexes were evaluated against streptozotocin induced diabetic male albino rats.
文摘It is worthy to mention that the two broad bean cultivars displayed a surprising situation during the fruiting stage of growth. The absolute amount of pods yield was higher in cv. Assiut 125 than in cv. Assiut 84. This situation was in contrast with that in the vegetative stage, where cv. Assiut 84 produced greater vegetative growth than cv. Assiut 125. Although the cv. Assiut 84 was less affected by the highest dose of copper, the cv. Assiut 125 was greatly affected by this dose. However, another surprising situation was recorded when the absolute values of fresh and dry matter of cv. Assiut 125 were much higher than cv. Assiut 84 at any used copper concentration. The fresh matters of the pods of cv. Assiut 84 and cv. Assiut 125 were 7.24 and 10.16 gm at the level of control and 6.69 and 7.59 gm at the level of 350 ppm Cu, respectively. Their dry matters were 1.99 and 3.52 gm at the level of control and 1.77 and 2.13 gm at the level of 350 ppm Cu2+ in cv. Assiut 84 and cv. Assiut 125, respectively. This contradiction was also extended when these copper-affected cultivars were sprayed by IAA. The cv. Assiut 84 responded slightly to IAA treatment. On the other hand, a considerable increase in the dry matter yield was recorded in the pods of cv. Assiut 125 at any used level of copper when compared to the non-sprayed plants treated by the same copper concentration. At the level of 350 ppm Cu2+ , the pod yield was 2-fold that of plants treated only by 350 ppm Cu2+ , without IAA spraying. Thus, even IAA behaved differently in its effect on the crop yield of the two tested broad bean cultivars. There are big and surprising variations in the accumulation of microelements and heavy metals in pods among the two broad bean genotypes, whatever the treatments used. These variations seemed to be complicated which might need further studies. The concentration of amino acids and their individuals also varied among the two cultivars;they increased in cv. Assiut 84 and decreased in cv. Assiut 125. The increased amino acids in cv. Assiut 84 are mostly used as precursors for phytochelatins. For the previous studies, thus the present work was conducted to explain the effect of Cu and interactive effect with IAA on two selected broad bean cultivars Assiut 84 and Assiut 125 during yielding production.
文摘The effect of ethanol on the transport of amino acids across the human placenta was studied in the dual perfusion apparatus using a non-metabolizable α-amino isobutyric acid (AIB). Results were obtained for thirty intact whole human placentas in the absence (control group) and presence (ethanol group) of ethanol (500 - 1000 mg/dL). Experimental determinations of AIB transport at AIB concentrations of 5 - 100 mg/l, measured radioactively using (1−14 C-) AIB, were compared with a dual-active transport model. The diffusion coefficients of AIB were found to be (3.7 × 10−9 cm2/s) in the absence of ethanol and (2.3 × 10−9 cm2/s) in the presence of ethanol with no statistical difference (P = 0.25). The ratio of the fetal to maternal perfusate concentrations in the absence of ethanol (1.44) was statistically significant (P = 0.016) from the ratio in the presence of ethanol (1.20), which may indicate that active transport in the human placenta is inhibited by the presence of ethanol. The placental uptake from the maternal circulation was 2.6 (control) and 2.5 (ethanol) times greater than the uptake from the total circulation. The relative contribution of the diffusive transport to the net placental uptake of AIB from both the maternal and fetal circulations was less than that of active transport regardless of the presence of ethanol: control (38%) and ethanol (35%). It appears that the placental tissue plays the role of a mediator to maintain a fetal concentration higher than the maternal one by either enhancing the transfer from the maternal to the placental tissue or impairing the transfer in the opposite direction.
基金the Natural Sci-ence Foundation of HebeiProvince, No. C2005000840
文摘BACKGROUND: Nitric oxide synthase (NOS) inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate the ischemic neuronal damage with the release of excessively excitatory amino acids (EAA) during cerebral ischemia. On the other hand, some inhibitory amino acid is suggested to be important for the neuronal protection against ischemic brain damage. Our study has recently showed that treatment with the NOS inhibitor NG-nitro-L-arginine (L-NA) reduced focal cerebral ischemic damage. The effect of L-NA on the contents of excitatory and inhibitory amino acid in the rat brain following cerebral ischemia is still unclear. OBJECTIVE: By evaluating the effect of NOS inhibitor, L-NA on the contents of aspartate, glutamate, glycine and γ-aminobutyric acid (GABA) in striatum, hippocampus and cortex in the rat brain following cerebral ischemia respectively, to investigate the beneficial effect of L-NA on cerebral ischemic injury and the possible mechanism. DESIGN: A randomized and controlled experiment SETTING : Department of Pharmacology, Hebei Academy of Medical Sciences MATERIALS: A total of 42 male healthy SD rats (grade Ⅱ, weighting 250-300 g) were provided by the Experimental Animal Center of Hebei Province (Certification: 04036). Aspartate, glutamate, glycine, GABA, L-NA and 2,3,5-triphenyltetrazolium chloride (TTC) were obtained from Sigma Chemicals Co, St Louis, MO, USA. HPLC-ultraviolet detector system consisted of Agilent 1100 HPLC. METHODS: The experiment was carried out in Department of Pharmrcology, Hebei Academy of Medical Sciences from June 2005 to June 2006. Rats were randomly divided into three groups: sham-operated group (n = 6), ischemic group (n = 18), L-NA group (n = 18). The model of focal cerebral ischemia in rat was prepared with intraluminal line occlusion methods. In sham-operated rats, the external carotid artery was surgically prepared, but the filament was not inserted. Each group was further divided into 3 subgroups (n = 6 for each): drugs were administrated at 2, 6 and 12 hours after the middle cerebral artery occlusion (MCAO) respectively. L-NA (20 mg/kg, ip) was administrated, twice a day, for 3 consecutive days. Same volume of normal saline was administrated in ischemic and sham operation groups. The changes of infarcted volume and the contents of amino acids were respectively assayed. Image analysis software was used for the measurement of the infarcted area. The results were expressed as a percentage of the infarcted volume of cerebral/volume of whole brain (IV%) in order to control for edema formation. The contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in the rat brain following cerebral ischemia were respectively measured by HPLC method. All data were analyzed with one-way ANOVA and Dunnett's test. MAIN OUTCOME MEASURES: (1) The volume of cerebral infarction; (2) The contents of aspartate, glutamate glycine and GABA in brain tissue after cerebral ischemia. RESULTS : All 42 rats were involved in the final analysis. (1) Infarcted volume: Volume was 0 in sham-operated group. When L-NA was administrated at 2 and 6 hours after MCAO, the infarcted volume was (20.13±3.59)% and (23.12±5.84)% in L-NA group, which was not similar to that in ischemic group [(22.10±3.98)%, (25.38± 5.37)%, P〉 0.05]. However, the infarcted volume was markedly decreased compared with that of ischemic group when L-NA was administrated at 12 hours after MCAO [(26.11±3.55)% and (37.15±3.58)%, P 〈 0.01]. Changes of amino acid content: At 2 and 6 hours after ischemia, the contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in ischemic group were significantly increased compared with those in sham-operated group ( P〈 0.05-0.01). However, contents in L-NA group were similar to those in ischemic group (P 〉 0.05). At 12 hours after ischemia, the contents of aspartate [(0.21 ±0.06), (0.36±0.05), (0.29±0.12) mg/g] and glutamate [(0.55±0.06), (0.78±0.10), (0.52±0.10) mg/g] in striatum, hippocampus and cortex in L-NA group were significantly decreased compared with those in ischemic group [(0.49±0.17), (0.63± 0.03), (0.51±0.15) mg/g; (0.98±0.30), (1.15±0.15), (0.93±0.15) mg/g, P〈 0.05-0.01]. Glycine in hippocampus was (0.40±0.07) mg/g, which was higher than that in ischemic group [(0.21±0.07) mg/g, P 〈 0.05]. GABA in striatum, hippocampus and cortex was (0.93±0.10), (0.62±0.12) and (0.81 ±0.10) mg/g, respectively, which was higher than that in ischemic group [(0.60±0.08), (0.37±0.17), (0.59±0.10) mg/g, P 〈 0.05-0.01]. CONCLUSION : It may be concluded that L-NA have beneficial effect on ischemic cerebral injury in ischemic later stage in rats. The possible mechanism is that L-NA can decrease the contents of aspartate and glutamate, increase the contents of glycine and GABA.
基金supported by the National Key R&D Program of China (No.2019YFC1803704)。
文摘The digestibility of cadmium(Cd)in brown rice is directly related to amino acid metabolism in rice and human health.In our field study,three kinds of alkaline calcium-rich soil inorganic amendments(SIAs)at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated paddy.With the increased application of SIA,Cd content in iron plaque on rice root significantly increased,the transfer of Cd from rice root to grain significantly decreased,and then Cd content in brown rice decreased synchronously.The vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction test.Results showed that more than 70%of Cd in brown rice could be digested by simulated gastrointestinal juice.Based on the total and digestible Cd contents in brown rice to evaluate the health risk,the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy soils.The amino acids(AAs)in brown rice were determined by high-performance liquid chromatography.The contents of 5 key AAs(KAAs)that actively respond to environmental changes increased significantly with the increased application of SIA.The structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain,and consequently altered the ratio of indigestible Cd in brown rice.The formation of indigestible KAAs-Cd complexes by combining KAAs(phenylalanine,leucine,histidine,glutamine,and asparagine)with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd.
文摘In this study,we have examined the effects of exposure to high temperature, carbon inonoxideor a combination of both conditions in a model system,the rat and in industrial workers.In the rat liver, HSP70 mRNA and HSP70 synthesis were measured by dot hybridization and western blot. The results showed that after a heat stress HSP70 mRNA and its product, HSP70 increased significantly and there was a synergism in the combined effects of high temperature and carbon monoxide exposure on the induction of HSP70 mRNA and HSP70 synthesis. Heat played a major role in this induction. The presence of antibodies to human HSP27, HSP60, HSP70,HSC73, HSP89 αand β in workers exposed to heat, carbon monoxide was also measured by western blot using purified HSPs as antigens. Plasma free amino acids were measured in the saine group of workers. The incidence of antibodies to HSP27 and HSP70 Was significantly higher in the workers working in an environment with extreme heat, and high carbon monoxide ernission than in a control group. The carbon monoxide exposed group showed the highest incidence of antibodies to HSPs. Although our previous results indicated that workers had an insufficient protein intake,plasma free amino acids tended to increase, especially in methionine and tryptophan two kinds of amino acids which are absent from the main stress protein, HSP70.These results suggest that the major problems that these workers may face are how to facilitate the use of plasma free amino acids and reduce the inhibition of synthesis of normal proteins when they are exposed to occupational harmful factors.These resultsalso add new information on the measurement of HSPs as a potential biomonitor to assess whether organisms are experiencing metabolic stress within their environment.
基金supported by the earmarked fund for the Modern Agro-Industry Technology Research System (No. CARS-49)the Natural Science Foundation of Shan-dong Province (No. ZR2018BC052)+1 种基金the Entrepreneurship and Innovation Talents programme of Jiangsu Province of China (2020–2023)the Huaguo Mountain Talent Pro-gramme of Lianyungang City Jiangsu Province (2019–2022)。
文摘Cephalopods are important economic shellfish that have been developed extensively in the coastal water of various countries. Octopus vulgaris is a large-scaled economic cephalopod that is mainly cultured in South China. This study explored the effect of different diets on the volatile flavor and nutritional ingredients of O. vulgaris. Four diets were tested in four groups: Group A(fish(Scomberomorus niphonius)), Group B(crab(Helice tridens tientsinensis Rathbun)), Group C(clam(Mactra veneriformis)), and Group D(squid(Loligo japonica)). Octopus muscles were sampled after 36 days of feeding, and volatile flavor substances(VFSs), fatty acids(FAs), and amino acids(AAs) were detected. Results showed that the VFSs, FAs, and AAs of octopus in the four groups were obviously different. The sum of volatile ketones and aldehydes was higher in Group B than in the other groups, which could present much more flavors. All groups were abundant in unsaturated FAs, including eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA). In terms of content and variety, the FAs in Group B were more beneficial to human health than those in the other groups. The content of each AA in Group B was basically higher than those in the other groups and was significantly higher than that in Group D(P < 0.05). Comparing the VFSs, FAs, and AAs in samples fed with four kinds of diets, the results indicate that using crab to feed O. vulgaris can achieve better effects on volatile flavor and nutritional ingredients.
文摘L-type amino acid transporters(LATs) mainly assist the uptake of neutral amino acids into cells. Four LATs(LAT1, LAT2, LAT3 and LAT4) have so far been identified. LAT1(SLC7A5) has been attracting much attention in the field of cancer research since it is commonly up-regulated in various cancers. Basic research has made it increasingly clear that LAT1 plays a predominant role in malignancy. The functional significance of LAT1 in cancer and the potential therapeutic application of the features of LAT1 to cancer management are described in this review.
文摘The nanohydroxyapatites (HAP) and its biological effects have been studied using ultraviolet absorption spectrum, X-ray diffraction (XRD) structure analysis, fluorescent and infrared spectrum of absorption and MTT method. The nanohyd- roxyapatites are prepared and made by using Sol-gel method, in which the parameters of process and reaction are controlled as: PH 】9, Ca/P = 1.67, sintering temperature of 1100?C and sintering time 2 hours. The results of the study show that nanohydroxyapatites can absorb the amino acid molecules, the absorption is better for stronger acidity of amino acids. We also find that the nanohydroxyapatites and complex of nanoHAP+ nanoCrO2 can all restrain the proliferation of cells, but their toxiciteis are all first degree or minor, but the restrained effect of the latter is smaller than that of the former, although they can decrease the relative proliferation rate of cells. The nanohydroxyapatites can also change the molecular structure of human serum albumin.