Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances ar...Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.展开更多
Nitric oxide(NO),which generally originates from vehicle exhaust and industrial flue gases,is one of the most serious air pollutants.In this case,the electrochemical NO reduction reaction(NORR)not only removes the atm...Nitric oxide(NO),which generally originates from vehicle exhaust and industrial flue gases,is one of the most serious air pollutants.In this case,the electrochemical NO reduction reaction(NORR)not only removes the atmospheric pollutant NO but also produces valuable ammonia(NH_(3)).Hence,through the synthesis and modification of Fe_(3)C nanocrystal cata-lysts,the as-obtained optimal sample of Fe_(3)C/C-900 was adopted as the NORR catalyst at ambient conditions.As a result,the Fe_(3)C/C-900 catalyst showed an NH_(3)Faraday efficiency of 76.5%and an NH_(3)yield rate of 177.5μmol·h^(-1)·cm^(-2)at the working potentials of-0.8 and-1.2 V versus reversible hydrogen electrode(vs.RHE),respectively.And it delivered a stable NORR activity during the electrolysis.Moreover,we attribute the high NORR properties of Fe_(3)C/C-900 to two aspects:one is the enhanced intrinsic activity of Fe_(3)C nanocrystals,including the lowering of the energy barrier of rate-limiting step(*NOH→*N)and the inhibition of hydrogen evolution;on the other hand,the favorable dispersion of active components,the effective adsorption of gaseous NO,and the release of liquid NH_(3)products facilitated by the porous carbon substrate.展开更多
Nitric oxide(NO)modulates several cancer-related physiological processes and has advanced the development of green methods for cancer treatment and integrated platforms for combination or synergistic therapies.Althoug...Nitric oxide(NO)modulates several cancer-related physiological processes and has advanced the development of green methods for cancer treatment and integrated platforms for combination or synergistic therapies.Although a nanoengineering strategy has been proposed to overcome deficiencies of NO gas or small NO donor molecules,such as short half-life,lipophilicity,non-selectivity,and poor stability,it remains challenging to prepare NO nanomedicines with simple composition,multiple functions and enhanced therapeutic efficacy.Herein,we build a liquid metal nanodroplet(LMND)-based NO nanogenerator(LMND@HSG)that is stabilized by a bioreducible guanylated hyperbranched poly(amido amine)(HSG)ligand.Mechanically,the tumor microenvironment specifically triggers a cascade process of glutathione elimination,reactive oxygen species(ROS)generation,and NO release.According to actual demand,the ROS and NO concentrations could be readily controlled by tuning the LMND and HSG feed amounts.Along with the intrinsic anticancer property of LMND(ROS-mediated apoptosis and anti-angiogenesis),LMND@HSG administration could further enhance tumor growth suppression compared with LMND and HSG alone.Fromthis study,leveraging LMND for NO gas therapy provides more possibilities for the prospect of LMND-based anticancer nanomedicines.展开更多
Scientists have devoted considerable effort overs several decades to reduce automobile exhaust emissions,and one practical and important strategy is the catalytic conversion of nitric oxide(NO)[1].Previous studies hav...Scientists have devoted considerable effort overs several decades to reduce automobile exhaust emissions,and one practical and important strategy is the catalytic conversion of nitric oxide(NO)[1].Previous studies have shown that lanthanide(Ln)metals can catalytically reduce NO.Thus,the reactions of NO with Ln to form lanthanide-nitric oxide(LnNO)complexes have been designed and served as the simplest prototype molecules for studying NO chemisorption on metal surfaces[2].展开更多
OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first ...OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first predicted by network pharmacology and molecular docking,then the possible signaling pathways were systematically analyzed.Finally,the potential therapeutic targets and possible signaling pathways of AT-I on PI-IBS in Sprague-Dawley(SD)rat model were verified by experiments.RESULTS:AT-I could alleviate PI-IBS symptoms and reduce the expression of tumor necrosis factorα,interleukin-6 and Interferon-gamma in PI-IBS SD rat model and inhibit the c-Jun N-terminal kinase/inducible nitric oxide synthase(JNK/iNOS)pathway.Notably,AT-I treatment could inhibit the overexpression of polymeraseⅠand transcript release factor(PTRF).CONCLUSION:AT-I could alleviate PI-IBS symptoms through downregulation of PTRF and inhibiting the JNK/iNOS pathway.This study not only provides a scientific basis to clarify the anti-PI-IBS effect of AT-I and its mechanism but also suggests a novel promising therapeutic strategy to treat the PI-IBS.展开更多
[Objective] Effects of different concentrations of nitric oxide on membrane lipid peroxidation of wheat induced by enhanced UV-B radiation were researched,sodium nitroprusside （SNP） was selected as an exogenous nitr...[Objective] Effects of different concentrations of nitric oxide on membrane lipid peroxidation of wheat induced by enhanced UV-B radiation were researched,sodium nitroprusside （SNP） was selected as an exogenous nitric oxide（NO）donor.[Method] There are 3 groups including CK,UV treatment group （B）,B＋SNP treatment group,0,1,2,3,4 d sampling after treatment respectively,and physiological and biochemical indexes of MDA content and CAT,POD,SOD and so on were determined,repeated 3 times,and statistical analyzed.[Result] The results showed that,after the enhanced UV-B radiation,activity of the catalase （CAT）,superoxide dismutase （SOD） and of the guaiacol peroxidase （POD） all reduced apparently,and the concentration of malondialdehyde （MDA） increased obviously,leading to oxidative damage in wheat seedlings.Impose different concentrations of SNP after UV-B radiation,may mitigate oxidative damage of wheat seedling from different degrees,which was in agreement with the effect of making the concentration of MDA decrease and the activity of the CAT,SOD and POD all increased.The mitigation role of 0.01 mol/L SNP was more obvious for roots＇ oxidative damage,while 0.1 mmol/L SNP is more effective for oxidative damage of leaves.[Conclusion] Exogenous NO donor SNP had obvious relieve effects on oxidative damage of wheat seedlings caused by UV-B radiation,which can enhance adaptive capacity of plants to adversity stress.展开更多
Inflammatory bowel diseases(IBDs), including Crohn's disease and ulcerative colitis are complex disorders with undetermined etiology. Several hypotheses suggest that IBDs result from an abnormal immune response ag...Inflammatory bowel diseases(IBDs), including Crohn's disease and ulcerative colitis are complex disorders with undetermined etiology. Several hypotheses suggest that IBDs result from an abnormal immune response against endogenous flora and luminal antigens in genetically susceptible individuals. The dysfunction of the mucosal immune response is implicated in the pathogenesis of IBD. The balance between pro-inflammatory cytokines [tumor necrosis factor(TNF)-α, interleukin(IL)-1b, IL-8, and IL-17A], anti-inflammatory cytokines(IL-4 and IL-13), and immunoregulatory cytokines(IL-10 and transforming growth factors b) is disturbed. Moreover, evidence from animal and clinical studies demonstrate a positive correlation between an increased concentration of nitric oxide(NO) and the severity of the disease. Interestingly, proinflammatory cytokines are involved in the up-regulation of inducible oxide synthase(iN OS) expression in IBD. However, anti-inflammatory and immunoregulatory cytokines are responsible for the negative regulation of iN OS. A positive correlation between NO production and increased pro-inflammatory cytokine levels(TNF-α, IL-6, IL-17, IL-12, and interferon-γ) were reported in patients with IBD. This review focuses on the role of cytokines in intestinal inflammation and their relationship with NO in IBD.展开更多
AIM： To determine the expressions of inducible nitric oxide synthase （iNOS） and matrix metalloproteinase-9 （MMP-9） in hepatocellular carcinoma （HCC） and to investigate the relationship between iNOS and MMP-9 ex...AIM： To determine the expressions of inducible nitric oxide synthase （iNOS） and matrix metalloproteinase-9 （MMP-9） in hepatocellular carcinoma （HCC） and to investigate the relationship between iNOS and MMP-9 expression and their effects on angiogenesis and progression of HCC.METHODS： In this study, we examined iNOS, MMP-9, and CD34 expression in specimens surgically removed from 32 HCC patients and 7 normal liver tissues by immunohistochemical staining. Meanwhile, microvessel density （MVD） was determined as a marker of angiogenesis by counting CD34-positive cells. RESULTS： The positive rates of iNOS and MMP-9 expression were 71.88% （23/32） and 78.13% （25/32） in HCC. MMP-9 expression was significantly correlated with tumor size, capsule status, TNM stage, and risk of HCC recurrence （P = 0.032, P= 0.033, P= 0.007, and P= 0.001, respectively）. There was also a significant relationship between iNOS expression and capsule status and risk of HCC recurrence （P = 0.049 and P = 0.004, respectively）, but no correlation between iNOS expression and tumor size and TNM stage. There was a positive association between MVD and TNM stage and risk of HCC recurrence （P = 0.037 and P = 0.000, respectively）. The count of MVD was significantly different in different iNOS and MMP-9 immunoreactivity groups （F= 17.713 and 17.097, P= 0.000 and P = 0.000, respectively）. The examination of Spearman＇s rank correlation coefficient showed that there was a significant positive correlation between MVD and iNOS, MMP-9 immunoreactivity （r = 0.754 and 0.751, P= 0.000 and P=-0.000, respectively）. There was also a significant association between MMP-9 and iNOS expression in HCC （P = 0.010）. CONCLUSION： Nitric oxide （NO） produced by iNOS could modulate MMP-9 production and therefore contribute totumor cell angiogenesis and invasion and metastasis in HCC. The strong expression of iNOS and MMP-9 in HCC may be helpful in evaluating the recurrence of HCC, predicting poor prognosis. For patients with strong expression of MMP-9 and iNOS, the optimal treatment scheme needs to be selected.展开更多
AIM:Cydooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins.Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide. Both have constitutive and inducible i...AIM:Cydooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins.Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide. Both have constitutive and inducible isoforms.The inducible isoforms (iNOS and COX-2) are of great interest as regulators of tumor angiogenesis,tumorigenesis and inflammatory processes.This study was to clarify their role in pancreatic adenocarcinomas. METHODS:We investigated the immunohistochemical iNOS and COX-2 expression in 40 pancreatic ductal adenocardnomas of different grade and stage.The results were compared with microvessel density and dinicopathological data. RESULTS:Twenty-one (52.5%) of the cases showed iNOS expression,15 (37.5%) of the cases were positive for COX-2. The immunoreaction was heterogeneously distributed within the tumors.Staining intensity was different between the tumors.No correlation between iNOS and COX-2 expression was seen.There was no relationship with microvessel density. However,iNOS positive tumors developed more often distant metastases and the more malignant tumors showed a higher COX-2 expression.There was no correlation with other clinicopathological data. CONCLUSION:Approximately half of the cases expressed iNOS and COX-2.These two enzymes do not seem to be the key step in angiogenesis or carcinogenesis of pancreatic adenocarcinomas.Due to a low prevalence of COX-2 expression,chemoprevention of pancreatic carcinomas by COX-2 inhibitors can only achieve a limited success.展开更多
Objective: The present study is designed to investigate the cellular expressions and immunolocalizations of three different nitric oxide synthase (NOS) isoforms and the related nitric oxide (NO)/cyclic guanosine monop...Objective: The present study is designed to investigate the cellular expressions and immunolocalizations of three different nitric oxide synthase (NOS) isoforms and the related nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway in the ovaries of neonatal and immature rats.Methods: The ovaries were obtained from ICR (Institute for Cancer Research) female Sprague-Dawley rats at postnatal days 1,5,7,10,and 19.Then we carried out the histologic examination,immunohistochemistry,measurement of NOS activity,and modifications within the NO/cGMP pathway.Results: During postnatal days 1,5,7,10,and 19,all three isoforms of NOS were mainly localized to the oocytes and expressed as a gradual increase in granulosa cells and theca cells within the growing follicle.The ovarian total NOS activities and NO levels were increased at postnatal days 7 and 10 compared with other days.Conclusions: Our findings suggest that the locally produced NO and the NO/NOS signaling systems are involved in the follicular development to puberty.展开更多
AIM: To study the effects of aminoguanidine (AG) and two L-arginine analogues N(omega)-nitro-L-arginine methyl ester (L-NAME) and N(omega)-nitro-L-arginine (L-NNA) on nitric oxide (NO) production induced by cytokines ...AIM: To study the effects of aminoguanidine (AG) and two L-arginine analogues N(omega)-nitro-L-arginine methyl ester (L-NAME) and N(omega)-nitro-L-arginine (L-NNA) on nitric oxide (NO) production induced by cytokines (TNF-alpha, IL-1 beta, and IFN-gamma) and bacterial lipopolysaccharide (LPS) mixture (CM) in the cultured rat hepatocytes, and examine their mechanisms action. METHODS: Rat hepatocytes were incubated with AG, L-NAME, L-NNA, Actinomycin D (ActD) and dexamethasone in a medium containing CM (LPS plus TNF-alpha, IL-1 beta, and IFN-gamma) for 24h. NO production in the cultured supernatant was measured with the Griess reaction. Intracellular cGMP level was detected with radioimmunoassy. RESULTS: NO production was markedly blocked by AG and L-NAME in a dose-dependent manner under inflammatory stimuli condition triggered by CM in vitro. The rate of the maximum inhibitory effects of L-NAME (38.9%) was less potent than that obtained with AG(53.7%, P 【 0.05). There was no significant difference between the inhibitory effects of AG and two L-arginine analogues on intracellular cGMP accumulation in rat cultured hepatocytes. Non-specific NOS expression inhibitor dexamethasone (DEX)and iNOS mRNA transcriptional inhibitor ActD also significantly inhibited CM-induced NO production. AG(0.1 mmol x L(-1)) and ActD (0.2 ng x L(-1)) were equipotent in decreasing NO production induced by inflammatory stimuli in vitro, and both effects were more potent than that induced by non-selectivity NOS activity inhibitor L-NAME (0.1 mmol x L(-1)) under similar stimuli conditions (P【0.01). CONCLUSION: AG is a potent selective inhibitor of inducible isoform of NOS,and the mechanism of action may be not only competitive inhibition in the substrate level, but also the gene expression level in rat hepatocytes.展开更多
AIM: To investigate the expression of NOS in gastric carcinoma, and to explore the relationship between the expression of nitric oxide synthases (NOS) and p53, PCNA,pathological features and clinical staging of gastri...AIM: To investigate the expression of NOS in gastric carcinoma, and to explore the relationship between the expression of nitric oxide synthases (NOS) and p53, PCNA,pathological features and clinical staging of gastric cancer.METHODS: The activity of NOS protein was investigated in 85 samples of human gastric carcinoma and 25 samples of normal gastric mucosal tissue by biochemical assay. We then examined the expression of NOS, p53, PCNA in 85 samples of human gastric cancer was examined by immunohistochemistry, and NOS mRNA expression in 85 gastric cancer tissue specimens by in situ hybridization.RESULTS: Biochemical assay showed that the activity of NOS was significantly higher in gastric carcinoma than in normal gastric mucosal tissues (t = 0.4161, P＜0.01).Immunohistochemistry revealed that endothelial nitric oxide synthase (eNOS) expressed in all samples of normal gastric mucosa, but only 6 cases of 85 gastric cancer specimens showed weak positive immunohistochemical reactions to eNOS (20%). Inducible nitric oxide synthase (iNOS) was expressed strongly in human gastric carcinoma (81.2%). In situ hybridization analysis showed that iNOS mRNA expression was significantly stronger than eNOS mRNA expression in gastric cancer tissue (x2 = 10.23, P＜0.01). The expression of iNOS in gastric cancer was associated with differentiation, clinical stages or lymph node metastases (r= 0.3426, P＜0.05). However,iNOS expression did not correlate with histological classifications and morphological types. The expression of iNOS was significantly correlated with p53 or PCNA expression (r = 0.3612, P＜0.05). The expression of neuronal nitric oxide synthase (nNOS) was not examined by immunohistochemistry and in situ hybridization in gastric cancer specimens and normal gastric mucosa.CONCLUSION: In human gastric cancer, there is an enhanced expression of iNOS, but not of eNOS. NOS promotes the proliferation of tumor cells and plays an important role in gastric cancer spread. Inactivation of antioncogene p53 and overexpression of iNOS might play a synergetic role in the process of carcinogenesis of human gastric carcinoma.展开更多
AIM： To study the effects of endogeous nitric oxide induced by 5-fluorouracil （5-FU） and L-arginine （L-Arg） on the human liver carcinoma model in nude mice. METHODS： The human liver carcinoma model in nude mice ...AIM： To study the effects of endogeous nitric oxide induced by 5-fluorouracil （5-FU） and L-arginine （L-Arg） on the human liver carcinoma model in nude mice. METHODS： The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline （NS）, 5-FU and 5-FU ＋ L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling （TUNEL） method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide （NO） in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry. RESULTS： 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU＋L- Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3, respectively （P 〈 0.05 5-FU vs 5-FU ± L-Arg group;P 〈 0.05 NS ys 5-FU ± L-Arg group; P 〈 0.05, NS ys 5-FU group）. The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU ＋ L-Arg group （X^2= 15.963, P 〈 0.05）. The apoptosis indexes were as follows： NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU ± L-Arg, 46% ± 15.24% （P 〈 0.05, 5-FU ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU）. The expression and activity of iNOS were increased in the tumor tissue. The concentration of NO was also increased. F of opticaldensity of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P 〈 0.05. The concentration of NO was related to the expression of PI6 and BAX. The correlation coefficient was 0.764 and 0.554. CONCLUSION： 5-FU combined with L-Arg can inhibit the growth of tumor in nude mice. The effect may be related to inducing the synthesis and increasing the activity of iNOS. The production of NO is increased, and it can enhance the expression of apoptosis-related gene and antioncogene.展开更多
AIM： To explore rectal nitric oxide （NO） as biomarker of treatment response in ulcerative colitis （UC） and Crohn＇s disease （CD）, and examine relationships between rectal NO, mucosal expression of NO synthases ...AIM： To explore rectal nitric oxide （NO） as biomarker of treatment response in ulcerative colitis （UC） and Crohn＇s disease （CD）, and examine relationships between rectal NO, mucosal expression of NO synthases （NOS）, and pro-inflammatory cytokines. METHODS： Twenty-two patients with UC and 24 with CD were monitored during steroid treatment. Rectal NO levels were measured and clinical activities were assessed on days 1, 3, 7 and 28. Mucosal presence of NOS and pro-inflammatory cytokines were analyzed by immunohistochemistry and RT-PCR. RESULTS： Active UC and CD displayed markedly increased rectal NO levels （10950 ± 7610 and 5 040 ± 1 280 parts per billion （ppb）, respectively） as compared with the controls （154 ± 71 ppb, P 〈 0.001）. Rectal NO correlated weakly with disease activity in both UC and CD （r = 0.34 for UC and r = 0.48 for CD, P 〈 0.01）. In 12 patients, a steroid-refractory course led to colectomy. These patients had only slightly increased NO levels （UC： 620 ± 270 ppb; CD： 1260 ± 550 ppb） compared to those with a therapeutic response （UC： 18860 ± 530 ppb, P 〈 0.001, CD： 10060 ± 3200 ppb, P 〈 0.05）. CONCLUSION： Rectal NO level is a useful biomarker of treatment response in IBD as low NO levels predicts a poor clinical response to steroid treatment.展开更多
NO is now known to be an important messenger molecule in biology.It regulates a variety of functions within cells and tissues including vasodilation, neurotransmission and immunological process. This review will focus...NO is now known to be an important messenger molecule in biology.It regulates a variety of functions within cells and tissues including vasodilation, neurotransmission and immunological process. This review will focus on the nitric oxide synthase gene family and recent progress on molecular genetic analysis of NOS1, NOS2 and N0S3 genes.展开更多
In this study, we examined the expression of inducible nitric oxide s ynthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistoc hemi cal staining in 76 tissue sections collected from hepatocellula...In this study, we examined the expression of inducible nitric oxide s ynthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistoc hemi cal staining in 76 tissue sections collected from hepatocellular carcinoma (HCC) patients undergoing hepatectomy. Microvascular density (MVD) was determined by counting endothelial cells immunostained using anti-CD34 antibody. We performe d DNA-flow cytometric analyses to elucidate the impact of iNOS and VEGF expressi o n on the cell cycle of HCC. Most of the HCC cells that invaded stroma were mark edly immunostained by iNOS antibody. The iNOS stain intensity of the liver tissu e close to the tumor edge was stronger than that of HCC tissue, and the stronges t was the hepatocytes closer to the tumor tissue. However, iNOS expression in 10 normal hepatic samples was undetectable. VEGF positive expression ratio was 84. 8% in iNOS positive expression cases, and the ratio was 35.3% in negative cases. There was significant correlation (P=0.000) between iNOS and VEGF expressi on. Moreover, iNOS expression was significantly associated with bcl-2 and MVD, but w ithout p53 expression. DNA-flow cytometric analyses showed that combined expres s ion of iNOS and VEGF had significant impact on the cell cycle in HCC. PI (Proli ferating Index) and SPF (S-phase fraction) in the combined positive expression o f iNOS and VEGF group was significantly higher than that in the combined negativ e group. The present findings suggested that iNOS expression was significantly a ssociated with angiogenesis, bcl-2 and cell proliferation of HCC.展开更多
A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD,BET and TPR.Catalyst CuCoOx/TiO2 ...A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD,BET and TPR.Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2,CuCo total loading of 30%at the calcination temperature of 350℃formed CuCo204 spinel and had the highest activity.NO conversion reached 98.9%at 200℃.Mechanism of the reduction was also investigated,N20 was mainly yielded below 100℃,while N2 was produced instead at higher temperature.O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2,but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly.Either SO2 or H20 had no adverse impact on the activity of NO reduction;however,in the presence of both SO2 and H20,the catalyst deactivated quickly.展开更多
AIM： To study the expression and activity of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） in rats with ethanol-induced liver injury and their relation with liver damage, act...AIM： To study the expression and activity of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） in rats with ethanol-induced liver injury and their relation with liver damage, activation of nuclear factor-KB （NF-κB） and tumor necrosis factor-α （TNF-α） expression in the liver. METHODS： Female Sprague-Dawley rats were given fish oil （0.5 mL） along with ethanol or isocaloric dextrose daily via gastrogavage for 4 or 6 wk. Liver injury was assessed using serum alanine aminotransferase （ALT） activity and pathological analysis. Liver malondialdehyde （MDA）, nitric oxide contents, iNOS and eNOS activity were determined. NF-κB p65, iNOS, eNOS and TNF-α protein or mRNA expression in the liver were detected by immunohistochemistry or reverse transcriptase-polymerase chain reaction （RT-PCR）. RESULTS： Chronic ethanol gavage for 4 wk caused steatosis, inflammation and necrosis in the liver, and elevated serum ALT activity. Prolonged ethanol administration （6 wk） enhanced the liver damage. These responses were accompanied with increased lipid peroxidation, NO contents, iNOS activity and reduced eNOS activity. NF-κB p65, iNOS and TNF-α protein or mRNA expression were markedly induced after chronic ethanol gavage, whereas eNOS mRNA expression remained unchanged. The enhanced iNOS activity and expression were positively correlated with the liver damage, especially the necro-inflammation, activation of NF-KB, and TNF-α mRNA expression. CONCLUSION： iNOS expression and activity are induced in the liver after chronic ethanol exposure in rats, which are correlated with the liver damage, especially the necro-inflammation, activation of NF-KB and TNF-α expression, eNOS activity is reduced, but its mRNA expression is not affected.展开更多
In the present study, a series of novel nitric oxide-hydrogen sulfide releasing derivatives of(S)-3-n-butylphthalide((S)-NBP) were designed, synthesized, and evaluated as potential antiplatelet agents. Compound NOSH-N...In the present study, a series of novel nitric oxide-hydrogen sulfide releasing derivatives of(S)-3-n-butylphthalide((S)-NBP) were designed, synthesized, and evaluated as potential antiplatelet agents. Compound NOSH-NBP-5 displayed the strongest activity in inhibiting the arachidonic acid(AA)- and adenosine diphosphate(ADP)-induced platelet aggregation in vitro, with 3.8- and 7.0-fold more effectiveness than(S)-NBP, respectively. Furthermore, NOSH-NBP-5 could release moderate levels of NO and H2 S, which would be beneficial in improving cardiovascular and cerebral circulation. Moreover, NOSH-NBP-5 could release(S)-NBP when incubated with rat brain homogenate. In conclusion, these findings may provide new insights into the development of novel antiplatelet agents for the treatment of thrombosis-related ischemic stroke.展开更多
Objective： To investigate the relationships between endothelial nitric oxide synthases （eNOS） G894T and 27 bpvariable number tandem repeat （VNTR） gene polymorphisms and osteoporosis in the postmenopausal women of...Objective： To investigate the relationships between endothelial nitric oxide synthases （eNOS） G894T and 27 bpvariable number tandem repeat （VNTR） gene polymorphisms and osteoporosis in the postmenopausal women of Chinese Han nationality. Methods： In the present study, 281 postmenopausal women from Xi＇an urban area in West China were recruited, and divided into osteoporosis, osteopenia, and normal groups according to the diagnostic criteria of osteoporosis proposed by World Health Organization （WHO）. The bone mineral density （BMD） values of lumbar vertebrae and left hips were determined by QDR-2000 dual energy X-ray absorptiometry. Blood samples were tested for plasma biochemical indicators including testosterone, estradiol, calcitonin, osteocalcin, and procollagen type I amino-terminal propeptide by enzyme-linked immunosorbent assay （ELISA）, tartrate-resistant acid phosphatase by spectrophotometric method, and the content of nitric oxide by Griess method. Genome DNA was extracted from whole blood, and G894T polymorphism of eNOS gene was analyzed by using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method and 27 bp-VNTR polymorphism of eNOS gene was genotyped by PCR method. Then the relationships between genotypes and biochemical indicators, genotypes and osteoporosis, and haplotypes and osteoporosis were analyzed. Results： The average BMD values of the femoral neck, ward＇s triangle and lumbar vertebrae 1-4 （LI-L4） in the subjects with T/T genotype in eNOS G894T locus were significantly higher than those in the subjects with G/T and G/G genotypes （P〈0.05）. The average BMD of the femoral neck in the subjects with a/a genotype of eNOS 27 bp-VNTR locus was evidently higher than that in the subjects with b/b genotype （P〈0.05）. The plasma testosterone and osteocalcin concentrations in the subjects of eNOS G894T G/T genotype were evidently higher than those in the subjects of other genotypes （P〈0.05）; the plasma estradiol concentration in the subjects of eNOS 27 bp-VNTR a/a genotype was obviously higher than that in the subjects of b/b genotype （P〈0.01）. eNOS G/G homozygous frequencies in osteoporosis women, osteopenia women, and normal women were 85.37%, 76.38%, and 83.87%, respectively （P〉0.05）. 0% osteoporosis woman, 0.79% osteopenia women, and 3.23% normal women were eNOS a/a homozygous （P〈0.05）. The frequencies of eNOS 27 bp-VNTR a allele were 5.33% in the osteoporosis group, 10.24% in the osteopenia group, and 16.13% in the normal group （P〈0.05, odds ratio （OR）=0.29, 95% confidence interval （CI）=0.11-0.77）, suggesting that a/a genotype and a allele might have protective effects on osteoporosis. The haplotype analysis showed that G-b was 87.7% （214/244） in the osteoporosis group （P〈0.05, OR=2.48, 95% CI=1. 18-5.18）. G-a was 5.3% （13/244） in the osteoporosis group （P〈0.05, OR=0.29, 95% CI=0. 11-0.77）. G-b was a risk factor for osteoporosis, and G-a a protective factor. Conclusion： eNOS G894T G/T genotype influenced the plasma testosterone and osteocalcin concentrations, and T/T genotype influenced BMD. eNOS 27 bp-VNTR a/a genotype increased plasma estradiol concentration to have a protective effect on osteoporosis.展开更多
基金funding support from General Research Fund[Project No.14300525]from the Research Grants Council(RGC)of Hong Kong SAR,Chinafunding support from Natural Science Foundation of China(NSFC)Young Scientists Fund(Project No.22305203)+2 种基金NSFC Projects Nos.22309123,22422303,22303011,22033002,92261112 and U21A20328support from the Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM)at City University of Hong Kongsupport from Young Collaborative Research Grant[Project No.C1003-23Y]support from RGC of Hong Kong SAR,China.
文摘Electrocatalytic nitric oxide(NO)reduction reaction(NORR)is a promising and sustainable process that can simultaneously realize green ammonia(NH3)synthesis and hazardous NO removal.However,current NORR performances are far from practical needs due to the lack of efficient electrocatalysts.Engineering the lattice of metal-based nanomaterials via phase control has emerged as an effective strategy to modulate their intrinsic electrocatalytic properties.Herein,we realize boron(B)-insertion-induced phase regulation of rhodium(Rh)nanocrystals to obtain amorphous Rh_(4)B nanoparticles(NPs)and hexagonal close-packed(hcp)RhB NPs through a facile wet-chemical method.A high Faradaic efficiency(92.1±1.2%)and NH_(3) yield rate(629.5±11.0μmol h^(−1) cm^(−2))are achieved over hcp RhB NPs,far superior to those of most reported NORR nanocatalysts.In situ spectro-electrochemical analysis and density functional theory simulations reveal that the excellent electrocatalytic performances of hcp RhB NPs are attributed to the upshift of d-band center,enhanced NO adsorption/activation profile,and greatly reduced energy barrier of the rate-determining step.A demonstrative Zn-NO battery is assembled using hcp RhB NPs as the cathode and delivers a peak power density of 4.33 mW cm−2,realizing simultaneous NO removal,NH3 synthesis,and electricity output.
基金supported by the Guangxi Natural Science Fund for Distinguished Young Scholars(2024GXNSFFA010008)Shenzhen Science and Technology Program(JCYJ20230807112503008).
文摘Nitric oxide(NO),which generally originates from vehicle exhaust and industrial flue gases,is one of the most serious air pollutants.In this case,the electrochemical NO reduction reaction(NORR)not only removes the atmospheric pollutant NO but also produces valuable ammonia(NH_(3)).Hence,through the synthesis and modification of Fe_(3)C nanocrystal cata-lysts,the as-obtained optimal sample of Fe_(3)C/C-900 was adopted as the NORR catalyst at ambient conditions.As a result,the Fe_(3)C/C-900 catalyst showed an NH_(3)Faraday efficiency of 76.5%and an NH_(3)yield rate of 177.5μmol·h^(-1)·cm^(-2)at the working potentials of-0.8 and-1.2 V versus reversible hydrogen electrode(vs.RHE),respectively.And it delivered a stable NORR activity during the electrolysis.Moreover,we attribute the high NORR properties of Fe_(3)C/C-900 to two aspects:one is the enhanced intrinsic activity of Fe_(3)C nanocrystals,including the lowering of the energy barrier of rate-limiting step(*NOH→*N)and the inhibition of hydrogen evolution;on the other hand,the favorable dispersion of active components,the effective adsorption of gaseous NO,and the release of liquid NH_(3)products facilitated by the porous carbon substrate.
基金the National Natural Science Foundation of China(22075114,32371434,82301630)the Natural Science Foundation of Jiangsu Province(BK20211034)the financial support from Jiangsu Provincial Medical Key Laboratory(Key Laboratory of Nuclear Medicine).
文摘Nitric oxide(NO)modulates several cancer-related physiological processes and has advanced the development of green methods for cancer treatment and integrated platforms for combination or synergistic therapies.Although a nanoengineering strategy has been proposed to overcome deficiencies of NO gas or small NO donor molecules,such as short half-life,lipophilicity,non-selectivity,and poor stability,it remains challenging to prepare NO nanomedicines with simple composition,multiple functions and enhanced therapeutic efficacy.Herein,we build a liquid metal nanodroplet(LMND)-based NO nanogenerator(LMND@HSG)that is stabilized by a bioreducible guanylated hyperbranched poly(amido amine)(HSG)ligand.Mechanically,the tumor microenvironment specifically triggers a cascade process of glutathione elimination,reactive oxygen species(ROS)generation,and NO release.According to actual demand,the ROS and NO concentrations could be readily controlled by tuning the LMND and HSG feed amounts.Along with the intrinsic anticancer property of LMND(ROS-mediated apoptosis and anti-angiogenesis),LMND@HSG administration could further enhance tumor growth suppression compared with LMND and HSG alone.Fromthis study,leveraging LMND for NO gas therapy provides more possibilities for the prospect of LMND-based anticancer nanomedicines.
基金the National Key Research and Development Program of China(No.2021YFB3501501)the National Natural Science Foundation of China(No.22276013)the Beijing Natural Science Foundation(No.2242009)for financial support,and thank Tianhe2-JK HPC for generous computer time.
文摘Scientists have devoted considerable effort overs several decades to reduce automobile exhaust emissions,and one practical and important strategy is the catalytic conversion of nitric oxide(NO)[1].Previous studies have shown that lanthanide(Ln)metals can catalytically reduce NO.Thus,the reactions of NO with Ln to form lanthanide-nitric oxide(LnNO)complexes have been designed and served as the simplest prototype molecules for studying NO chemisorption on metal surfaces[2].
基金The University Collaborative Innovation Project of Anhui:Creation of a Combined Animal Model of Coronary Heart Disease based on the Theory of Xin'an Medicine(No.GXXT-2020-024)Start-up Funding for Doctoral Research at Wannan Medical College(WYRCQD2018009)Horizontal Project of South Anhui Medical College(H202003)。
文摘OBJECTIVE:To explore the therapeutic effect and target of atractylenolide I(AT-I)on post-infectious irritable bowel syndrome(PI-IBS)rats.METHODS:Therefore,the preliminarily mechanism of AT-I in anti-PI-IBS were first predicted by network pharmacology and molecular docking,then the possible signaling pathways were systematically analyzed.Finally,the potential therapeutic targets and possible signaling pathways of AT-I on PI-IBS in Sprague-Dawley(SD)rat model were verified by experiments.RESULTS:AT-I could alleviate PI-IBS symptoms and reduce the expression of tumor necrosis factorα,interleukin-6 and Interferon-gamma in PI-IBS SD rat model and inhibit the c-Jun N-terminal kinase/inducible nitric oxide synthase(JNK/iNOS)pathway.Notably,AT-I treatment could inhibit the overexpression of polymeraseⅠand transcript release factor(PTRF).CONCLUSION:AT-I could alleviate PI-IBS symptoms through downregulation of PTRF and inhibiting the JNK/iNOS pathway.This study not only provides a scientific basis to clarify the anti-PI-IBS effect of AT-I and its mechanism but also suggests a novel promising therapeutic strategy to treat the PI-IBS.
基金Supported by National Natural Science Foundation of China(No.30671061)Natural Science Foundation of Shanxi Province(No.2008011059-1 and No.20041101)~~
文摘[Objective] Effects of different concentrations of nitric oxide on membrane lipid peroxidation of wheat induced by enhanced UV-B radiation were researched,sodium nitroprusside （SNP） was selected as an exogenous nitric oxide（NO）donor.[Method] There are 3 groups including CK,UV treatment group （B）,B＋SNP treatment group,0,1,2,3,4 d sampling after treatment respectively,and physiological and biochemical indexes of MDA content and CAT,POD,SOD and so on were determined,repeated 3 times,and statistical analyzed.[Result] The results showed that,after the enhanced UV-B radiation,activity of the catalase （CAT）,superoxide dismutase （SOD） and of the guaiacol peroxidase （POD） all reduced apparently,and the concentration of malondialdehyde （MDA） increased obviously,leading to oxidative damage in wheat seedlings.Impose different concentrations of SNP after UV-B radiation,may mitigate oxidative damage of wheat seedling from different degrees,which was in agreement with the effect of making the concentration of MDA decrease and the activity of the CAT,SOD and POD all increased.The mitigation role of 0.01 mol/L SNP was more obvious for roots＇ oxidative damage,while 0.1 mmol/L SNP is more effective for oxidative damage of leaves.[Conclusion] Exogenous NO donor SNP had obvious relieve effects on oxidative damage of wheat seedlings caused by UV-B radiation,which can enhance adaptive capacity of plants to adversity stress.
文摘Inflammatory bowel diseases(IBDs), including Crohn's disease and ulcerative colitis are complex disorders with undetermined etiology. Several hypotheses suggest that IBDs result from an abnormal immune response against endogenous flora and luminal antigens in genetically susceptible individuals. The dysfunction of the mucosal immune response is implicated in the pathogenesis of IBD. The balance between pro-inflammatory cytokines [tumor necrosis factor(TNF)-α, interleukin(IL)-1b, IL-8, and IL-17A], anti-inflammatory cytokines(IL-4 and IL-13), and immunoregulatory cytokines(IL-10 and transforming growth factors b) is disturbed. Moreover, evidence from animal and clinical studies demonstrate a positive correlation between an increased concentration of nitric oxide(NO) and the severity of the disease. Interestingly, proinflammatory cytokines are involved in the up-regulation of inducible oxide synthase(iN OS) expression in IBD. However, anti-inflammatory and immunoregulatory cytokines are responsible for the negative regulation of iN OS. A positive correlation between NO production and increased pro-inflammatory cytokine levels(TNF-α, IL-6, IL-17, IL-12, and interferon-γ) were reported in patients with IBD. This review focuses on the role of cytokines in intestinal inflammation and their relationship with NO in IBD.
文摘AIM： To determine the expressions of inducible nitric oxide synthase （iNOS） and matrix metalloproteinase-9 （MMP-9） in hepatocellular carcinoma （HCC） and to investigate the relationship between iNOS and MMP-9 expression and their effects on angiogenesis and progression of HCC.METHODS： In this study, we examined iNOS, MMP-9, and CD34 expression in specimens surgically removed from 32 HCC patients and 7 normal liver tissues by immunohistochemical staining. Meanwhile, microvessel density （MVD） was determined as a marker of angiogenesis by counting CD34-positive cells. RESULTS： The positive rates of iNOS and MMP-9 expression were 71.88% （23/32） and 78.13% （25/32） in HCC. MMP-9 expression was significantly correlated with tumor size, capsule status, TNM stage, and risk of HCC recurrence （P = 0.032, P= 0.033, P= 0.007, and P= 0.001, respectively）. There was also a significant relationship between iNOS expression and capsule status and risk of HCC recurrence （P = 0.049 and P = 0.004, respectively）, but no correlation between iNOS expression and tumor size and TNM stage. There was a positive association between MVD and TNM stage and risk of HCC recurrence （P = 0.037 and P = 0.000, respectively）. The count of MVD was significantly different in different iNOS and MMP-9 immunoreactivity groups （F= 17.713 and 17.097, P= 0.000 and P = 0.000, respectively）. The examination of Spearman＇s rank correlation coefficient showed that there was a significant positive correlation between MVD and iNOS, MMP-9 immunoreactivity （r = 0.754 and 0.751, P= 0.000 and P=-0.000, respectively）. There was also a significant association between MMP-9 and iNOS expression in HCC （P = 0.010）. CONCLUSION： Nitric oxide （NO） produced by iNOS could modulate MMP-9 production and therefore contribute totumor cell angiogenesis and invasion and metastasis in HCC. The strong expression of iNOS and MMP-9 in HCC may be helpful in evaluating the recurrence of HCC, predicting poor prognosis. For patients with strong expression of MMP-9 and iNOS, the optimal treatment scheme needs to be selected.
文摘AIM:Cydooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins.Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide. Both have constitutive and inducible isoforms.The inducible isoforms (iNOS and COX-2) are of great interest as regulators of tumor angiogenesis,tumorigenesis and inflammatory processes.This study was to clarify their role in pancreatic adenocarcinomas. METHODS:We investigated the immunohistochemical iNOS and COX-2 expression in 40 pancreatic ductal adenocardnomas of different grade and stage.The results were compared with microvessel density and dinicopathological data. RESULTS:Twenty-one (52.5%) of the cases showed iNOS expression,15 (37.5%) of the cases were positive for COX-2. The immunoreaction was heterogeneously distributed within the tumors.Staining intensity was different between the tumors.No correlation between iNOS and COX-2 expression was seen.There was no relationship with microvessel density. However,iNOS positive tumors developed more often distant metastases and the more malignant tumors showed a higher COX-2 expression.There was no correlation with other clinicopathological data. CONCLUSION:Approximately half of the cases expressed iNOS and COX-2.These two enzymes do not seem to be the key step in angiogenesis or carcinogenesis of pancreatic adenocarcinomas.Due to a low prevalence of COX-2 expression,chemoprevention of pancreatic carcinomas by COX-2 inhibitors can only achieve a limited success.
基金Project supported by the National Natural Science Foundation of China (No.30771553)National Basic Research Program (973) of China (No.2007CB947403)
文摘Objective: The present study is designed to investigate the cellular expressions and immunolocalizations of three different nitric oxide synthase (NOS) isoforms and the related nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway in the ovaries of neonatal and immature rats.Methods: The ovaries were obtained from ICR (Institute for Cancer Research) female Sprague-Dawley rats at postnatal days 1,5,7,10,and 19.Then we carried out the histologic examination,immunohistochemistry,measurement of NOS activity,and modifications within the NO/cGMP pathway.Results: During postnatal days 1,5,7,10,and 19,all three isoforms of NOS were mainly localized to the oocytes and expressed as a gradual increase in granulosa cells and theca cells within the growing follicle.The ovarian total NOS activities and NO levels were increased at postnatal days 7 and 10 compared with other days.Conclusions: Our findings suggest that the locally produced NO and the NO/NOS signaling systems are involved in the follicular development to puberty.
基金Project supported by the National Natural Science Foundation of China,No.39770861.and JANSSEN Science Research Foundation.
文摘AIM: To study the effects of aminoguanidine (AG) and two L-arginine analogues N(omega)-nitro-L-arginine methyl ester (L-NAME) and N(omega)-nitro-L-arginine (L-NNA) on nitric oxide (NO) production induced by cytokines (TNF-alpha, IL-1 beta, and IFN-gamma) and bacterial lipopolysaccharide (LPS) mixture (CM) in the cultured rat hepatocytes, and examine their mechanisms action. METHODS: Rat hepatocytes were incubated with AG, L-NAME, L-NNA, Actinomycin D (ActD) and dexamethasone in a medium containing CM (LPS plus TNF-alpha, IL-1 beta, and IFN-gamma) for 24h. NO production in the cultured supernatant was measured with the Griess reaction. Intracellular cGMP level was detected with radioimmunoassy. RESULTS: NO production was markedly blocked by AG and L-NAME in a dose-dependent manner under inflammatory stimuli condition triggered by CM in vitro. The rate of the maximum inhibitory effects of L-NAME (38.9%) was less potent than that obtained with AG(53.7%, P 【 0.05). There was no significant difference between the inhibitory effects of AG and two L-arginine analogues on intracellular cGMP accumulation in rat cultured hepatocytes. Non-specific NOS expression inhibitor dexamethasone (DEX)and iNOS mRNA transcriptional inhibitor ActD also significantly inhibited CM-induced NO production. AG(0.1 mmol x L(-1)) and ActD (0.2 ng x L(-1)) were equipotent in decreasing NO production induced by inflammatory stimuli in vitro, and both effects were more potent than that induced by non-selectivity NOS activity inhibitor L-NAME (0.1 mmol x L(-1)) under similar stimuli conditions (P【0.01). CONCLUSION: AG is a potent selective inhibitor of inducible isoform of NOS,and the mechanism of action may be not only competitive inhibition in the substrate level, but also the gene expression level in rat hepatocytes.
基金Supported by the Scientific Foundation of Jiangsu University,No.2631280055
文摘AIM: To investigate the expression of NOS in gastric carcinoma, and to explore the relationship between the expression of nitric oxide synthases (NOS) and p53, PCNA,pathological features and clinical staging of gastric cancer.METHODS: The activity of NOS protein was investigated in 85 samples of human gastric carcinoma and 25 samples of normal gastric mucosal tissue by biochemical assay. We then examined the expression of NOS, p53, PCNA in 85 samples of human gastric cancer was examined by immunohistochemistry, and NOS mRNA expression in 85 gastric cancer tissue specimens by in situ hybridization.RESULTS: Biochemical assay showed that the activity of NOS was significantly higher in gastric carcinoma than in normal gastric mucosal tissues (t = 0.4161, P＜0.01).Immunohistochemistry revealed that endothelial nitric oxide synthase (eNOS) expressed in all samples of normal gastric mucosa, but only 6 cases of 85 gastric cancer specimens showed weak positive immunohistochemical reactions to eNOS (20%). Inducible nitric oxide synthase (iNOS) was expressed strongly in human gastric carcinoma (81.2%). In situ hybridization analysis showed that iNOS mRNA expression was significantly stronger than eNOS mRNA expression in gastric cancer tissue (x2 = 10.23, P＜0.01). The expression of iNOS in gastric cancer was associated with differentiation, clinical stages or lymph node metastases (r= 0.3426, P＜0.05). However,iNOS expression did not correlate with histological classifications and morphological types. The expression of iNOS was significantly correlated with p53 or PCNA expression (r = 0.3612, P＜0.05). The expression of neuronal nitric oxide synthase (nNOS) was not examined by immunohistochemistry and in situ hybridization in gastric cancer specimens and normal gastric mucosa.CONCLUSION: In human gastric cancer, there is an enhanced expression of iNOS, but not of eNOS. NOS promotes the proliferation of tumor cells and plays an important role in gastric cancer spread. Inactivation of antioncogene p53 and overexpression of iNOS might play a synergetic role in the process of carcinogenesis of human gastric carcinoma.
基金the Grants for the Excellent Youth Scientists of Shandong Provincial Science Commission.No.2000BB2DBA1
文摘AIM： To study the effects of endogeous nitric oxide induced by 5-fluorouracil （5-FU） and L-arginine （L-Arg） on the human liver carcinoma model in nude mice. METHODS： The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline （NS）, 5-FU and 5-FU ＋ L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling （TUNEL） method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide （NO） in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry. RESULTS： 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU＋L- Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3, respectively （P 〈 0.05 5-FU vs 5-FU ± L-Arg group;P 〈 0.05 NS ys 5-FU ± L-Arg group; P 〈 0.05, NS ys 5-FU group）. The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU ＋ L-Arg group （X^2= 15.963, P 〈 0.05）. The apoptosis indexes were as follows： NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU ± L-Arg, 46% ± 15.24% （P 〈 0.05, 5-FU ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU）. The expression and activity of iNOS were increased in the tumor tissue. The concentration of NO was also increased. F of opticaldensity of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P 〈 0.05. The concentration of NO was related to the expression of PI6 and BAX. The correlation coefficient was 0.764 and 0.554. CONCLUSION： 5-FU combined with L-Arg can inhibit the growth of tumor in nude mice. The effect may be related to inducing the synthesis and increasing the activity of iNOS. The production of NO is increased, and it can enhance the expression of apoptosis-related gene and antioncogene.
基金Supported by the Swedish Research Council, Novo Nordisk and the Bengt Ihre fund
文摘AIM： To explore rectal nitric oxide （NO） as biomarker of treatment response in ulcerative colitis （UC） and Crohn＇s disease （CD）, and examine relationships between rectal NO, mucosal expression of NO synthases （NOS）, and pro-inflammatory cytokines. METHODS： Twenty-two patients with UC and 24 with CD were monitored during steroid treatment. Rectal NO levels were measured and clinical activities were assessed on days 1, 3, 7 and 28. Mucosal presence of NOS and pro-inflammatory cytokines were analyzed by immunohistochemistry and RT-PCR. RESULTS： Active UC and CD displayed markedly increased rectal NO levels （10950 ± 7610 and 5 040 ± 1 280 parts per billion （ppb）, respectively） as compared with the controls （154 ± 71 ppb, P 〈 0.001）. Rectal NO correlated weakly with disease activity in both UC and CD （r = 0.34 for UC and r = 0.48 for CD, P 〈 0.01）. In 12 patients, a steroid-refractory course led to colectomy. These patients had only slightly increased NO levels （UC： 620 ± 270 ppb; CD： 1260 ± 550 ppb） compared to those with a therapeutic response （UC： 18860 ± 530 ppb, P 〈 0.001, CD： 10060 ± 3200 ppb, P 〈 0.05）. CONCLUSION： Rectal NO level is a useful biomarker of treatment response in IBD as low NO levels predicts a poor clinical response to steroid treatment.
文摘NO is now known to be an important messenger molecule in biology.It regulates a variety of functions within cells and tissues including vasodilation, neurotransmission and immunological process. This review will focus on the nitric oxide synthase gene family and recent progress on molecular genetic analysis of NOS1, NOS2 and N0S3 genes.
文摘In this study, we examined the expression of inducible nitric oxide s ynthase (iNOS) and vascular endothelial growth factor (VEGF) by immunohistoc hemi cal staining in 76 tissue sections collected from hepatocellular carcinoma (HCC) patients undergoing hepatectomy. Microvascular density (MVD) was determined by counting endothelial cells immunostained using anti-CD34 antibody. We performe d DNA-flow cytometric analyses to elucidate the impact of iNOS and VEGF expressi o n on the cell cycle of HCC. Most of the HCC cells that invaded stroma were mark edly immunostained by iNOS antibody. The iNOS stain intensity of the liver tissu e close to the tumor edge was stronger than that of HCC tissue, and the stronges t was the hepatocytes closer to the tumor tissue. However, iNOS expression in 10 normal hepatic samples was undetectable. VEGF positive expression ratio was 84. 8% in iNOS positive expression cases, and the ratio was 35.3% in negative cases. There was significant correlation (P=0.000) between iNOS and VEGF expressi on. Moreover, iNOS expression was significantly associated with bcl-2 and MVD, but w ithout p53 expression. DNA-flow cytometric analyses showed that combined expres s ion of iNOS and VEGF had significant impact on the cell cycle in HCC. PI (Proli ferating Index) and SPF (S-phase fraction) in the combined positive expression o f iNOS and VEGF group was significantly higher than that in the combined negativ e group. The present findings suggested that iNOS expression was significantly a ssociated with angiogenesis, bcl-2 and cell proliferation of HCC.
基金supported by the Doctoral Fund of Ministry of Education of China(No.200805301004)the Hunan Provincial Natural Science Foundation of China(No.07JJ4003)the Scientific Research Fund of Hunan Provincial Education Department(No.08C890)
文摘A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD,BET and TPR.Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2,CuCo total loading of 30%at the calcination temperature of 350℃formed CuCo204 spinel and had the highest activity.NO conversion reached 98.9%at 200℃.Mechanism of the reduction was also investigated,N20 was mainly yielded below 100℃,while N2 was produced instead at higher temperature.O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2,but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly.Either SO2 or H20 had no adverse impact on the activity of NO reduction;however,in the presence of both SO2 and H20,the catalyst deactivated quickly.
文摘AIM： To study the expression and activity of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） in rats with ethanol-induced liver injury and their relation with liver damage, activation of nuclear factor-KB （NF-κB） and tumor necrosis factor-α （TNF-α） expression in the liver. METHODS： Female Sprague-Dawley rats were given fish oil （0.5 mL） along with ethanol or isocaloric dextrose daily via gastrogavage for 4 or 6 wk. Liver injury was assessed using serum alanine aminotransferase （ALT） activity and pathological analysis. Liver malondialdehyde （MDA）, nitric oxide contents, iNOS and eNOS activity were determined. NF-κB p65, iNOS, eNOS and TNF-α protein or mRNA expression in the liver were detected by immunohistochemistry or reverse transcriptase-polymerase chain reaction （RT-PCR）. RESULTS： Chronic ethanol gavage for 4 wk caused steatosis, inflammation and necrosis in the liver, and elevated serum ALT activity. Prolonged ethanol administration （6 wk） enhanced the liver damage. These responses were accompanied with increased lipid peroxidation, NO contents, iNOS activity and reduced eNOS activity. NF-κB p65, iNOS and TNF-α protein or mRNA expression were markedly induced after chronic ethanol gavage, whereas eNOS mRNA expression remained unchanged. The enhanced iNOS activity and expression were positively correlated with the liver damage, especially the necro-inflammation, activation of NF-KB, and TNF-α mRNA expression. CONCLUSION： iNOS expression and activity are induced in the liver after chronic ethanol exposure in rats, which are correlated with the liver damage, especially the necro-inflammation, activation of NF-KB and TNF-α expression, eNOS activity is reduced, but its mRNA expression is not affected.
基金supported by the National Natural Science Foundation for Young Scientists of China(Nos:21502071 and 21302068)the Natural Science Foundation of Jiangsu Province,China(Nos:BK20140154 and BK20130127)the Fundamental Research Funds for the Central Universities(Nos:JUSRP51411B and JUSRP51629B)
文摘In the present study, a series of novel nitric oxide-hydrogen sulfide releasing derivatives of(S)-3-n-butylphthalide((S)-NBP) were designed, synthesized, and evaluated as potential antiplatelet agents. Compound NOSH-NBP-5 displayed the strongest activity in inhibiting the arachidonic acid(AA)- and adenosine diphosphate(ADP)-induced platelet aggregation in vitro, with 3.8- and 7.0-fold more effectiveness than(S)-NBP, respectively. Furthermore, NOSH-NBP-5 could release moderate levels of NO and H2 S, which would be beneficial in improving cardiovascular and cerebral circulation. Moreover, NOSH-NBP-5 could release(S)-NBP when incubated with rat brain homogenate. In conclusion, these findings may provide new insights into the development of novel antiplatelet agents for the treatment of thrombosis-related ischemic stroke.
基金supported by the National Natural Science Foundation of China (Nos.30630058 and 30571725)the Xi'an Municipal Science and Technology Research Project Fund (No.GG06152)the Shanxi Provincial Science and Technology Research and Development Project Fund (No.2007K14-01),China
文摘Objective： To investigate the relationships between endothelial nitric oxide synthases （eNOS） G894T and 27 bpvariable number tandem repeat （VNTR） gene polymorphisms and osteoporosis in the postmenopausal women of Chinese Han nationality. Methods： In the present study, 281 postmenopausal women from Xi＇an urban area in West China were recruited, and divided into osteoporosis, osteopenia, and normal groups according to the diagnostic criteria of osteoporosis proposed by World Health Organization （WHO）. The bone mineral density （BMD） values of lumbar vertebrae and left hips were determined by QDR-2000 dual energy X-ray absorptiometry. Blood samples were tested for plasma biochemical indicators including testosterone, estradiol, calcitonin, osteocalcin, and procollagen type I amino-terminal propeptide by enzyme-linked immunosorbent assay （ELISA）, tartrate-resistant acid phosphatase by spectrophotometric method, and the content of nitric oxide by Griess method. Genome DNA was extracted from whole blood, and G894T polymorphism of eNOS gene was analyzed by using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method and 27 bp-VNTR polymorphism of eNOS gene was genotyped by PCR method. Then the relationships between genotypes and biochemical indicators, genotypes and osteoporosis, and haplotypes and osteoporosis were analyzed. Results： The average BMD values of the femoral neck, ward＇s triangle and lumbar vertebrae 1-4 （LI-L4） in the subjects with T/T genotype in eNOS G894T locus were significantly higher than those in the subjects with G/T and G/G genotypes （P〈0.05）. The average BMD of the femoral neck in the subjects with a/a genotype of eNOS 27 bp-VNTR locus was evidently higher than that in the subjects with b/b genotype （P〈0.05）. The plasma testosterone and osteocalcin concentrations in the subjects of eNOS G894T G/T genotype were evidently higher than those in the subjects of other genotypes （P〈0.05）; the plasma estradiol concentration in the subjects of eNOS 27 bp-VNTR a/a genotype was obviously higher than that in the subjects of b/b genotype （P〈0.01）. eNOS G/G homozygous frequencies in osteoporosis women, osteopenia women, and normal women were 85.37%, 76.38%, and 83.87%, respectively （P〉0.05）. 0% osteoporosis woman, 0.79% osteopenia women, and 3.23% normal women were eNOS a/a homozygous （P〈0.05）. The frequencies of eNOS 27 bp-VNTR a allele were 5.33% in the osteoporosis group, 10.24% in the osteopenia group, and 16.13% in the normal group （P〈0.05, odds ratio （OR）=0.29, 95% confidence interval （CI）=0.11-0.77）, suggesting that a/a genotype and a allele might have protective effects on osteoporosis. The haplotype analysis showed that G-b was 87.7% （214/244） in the osteoporosis group （P〈0.05, OR=2.48, 95% CI=1. 18-5.18）. G-a was 5.3% （13/244） in the osteoporosis group （P〈0.05, OR=0.29, 95% CI=0. 11-0.77）. G-b was a risk factor for osteoporosis, and G-a a protective factor. Conclusion： eNOS G894T G/T genotype influenced the plasma testosterone and osteocalcin concentrations, and T/T genotype influenced BMD. eNOS 27 bp-VNTR a/a genotype increased plasma estradiol concentration to have a protective effect on osteoporosis.
