Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been sy...Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with conv...展开更多
Previous studies have reported a neuroprotective effect of 8-hydroxy-2-（di-n-propylamino）tetralin （8-OH-DPAT） against traumatic brain injury. In accordance with the Marmarou method, rat models of diffuse axonal in...Previous studies have reported a neuroprotective effect of 8-hydroxy-2-（di-n-propylamino）tetralin （8-OH-DPAT） against traumatic brain injury. In accordance with the Marmarou method, rat models of diffuse axonal injury were established. 8-OH-DPAT was intraperitoneally injected into model rats. 8-OH-DPAT treated rats maintained at constant temperature served as normal temperature controls TUNEL results revealed that neural cell swelling, brain tissue necrosis and cell apoptosis occurred around the injured tissue. Moreover, the number of Bax-, Bcl-2- and caspase-3-positive cells increased at 6 hours after diffuse axonal injury, and peaked at 24 hours. However, brain injury was attenuated, the number of apoptotic cells reduced, Bax and caspase-3 expression decreased, and Bcl-2 expression increased at 6, 12, 24, 72 and 168 hours after diffuse axonal injury in normal temperature control and in 8-OH-DPAT-intervention rats. The difference was most significant at 24 hours. All indices in 8-OH-DPAT-intervention rats were better than those in the constant temperature group. These results suggest that 8-OH-DPAT inhibits Bax and caspase-3 expression, increases Bcl-2 expression, and reduces neural cell apoptosis, resulting in neuroprotection against diffuse axonal injury. This effect is associated with a decrease in brain temperature.展开更多
Reactive oxygen species may be involved in the progression of gastric carcinomas. To clarify whether the pathology of gastric carcinoma are related to oxidative DNA damage, the expression of 8-hydroxy-2＇-deoxyguanosi...Reactive oxygen species may be involved in the progression of gastric carcinomas. To clarify whether the pathology of gastric carcinoma are related to oxidative DNA damage, the expression of 8-hydroxy-2＇-deoxyguanosine （8-OHdG） was examined in 30 patients with gastric carcinomas. Methods： The expression of 8-OHdG and apoptosis in the gastric carcinoma were measured using the methods of immunocytochemistry and deoxynucleartididyl transferase-mediated dUTP-biotin nick end labeling （TUNEL）, respectively. Results： Of the 30 cases, 25（83%） showed stronger immunoreactivity than normal control. The patients with poorly differentiated gastric carcinoma had a larger tumor size and higher labeling indices of TUNEL- and 8-OHdG-positive cells than those with well and moderately differentiated gastric carcinoma. Conclusion： Our findings suggest that oxidative DNA damage is increased in association with necroinflammation in chronic gastric injuries and determination of 8-OHdG is useful in assessing high-grade malignancy in gastric carcinomas.展开更多
8-hydroxy-2’-deoxyguanosine (8-OHdG), a typical form ofDNA adducts, is a key molecular biomarker for DNA oxidativedamage. The aim of the present study was to evaluote the correla-tion between the sperm DNA 8-OHdG lev...8-hydroxy-2’-deoxyguanosine (8-OHdG), a typical form ofDNA adducts, is a key molecular biomarker for DNA oxidativedamage. The aim of the present study was to evaluote the correla-tion between the sperm DNA 8-OHdG level and the semen quality.In 52 male infertile patients, the sperm DNA 8-OHdG level wasdetermined by a high performance liquid chromatograph with elec-trochemical detector and the semen quality was examined according展开更多
Spontaneous preterm birth (SPTB) is characterized by the delivery of a baby before 37 completed weeks of gestation, and this condition is associated with significant health challenges for the newborn. Emerging evidenc...Spontaneous preterm birth (SPTB) is characterized by the delivery of a baby before 37 completed weeks of gestation, and this condition is associated with significant health challenges for the newborn. Emerging evidence highlights the importance of biomarkers for understanding the mechanisms underlying SPTB. One such biomarker, 8-OH-2dG, plays a critical role in evaluating oxidative stress and its impact on pregnancy outcomes. It has been demonstrated that 8-OH-2dG is a product of oxidative DNA damage and is widely recognized as a key indicator of cellular oxidative stress. Elevated reactive oxygen species in SPTB result in higher levels of the DNA degradation product 8-OH-2dG in amniotic fluid, causing damage to maternal and fetal tissues that could lead to premature rupture of fetal membranes. Therefore, evaluating the role of 8-OH-2dG in SPTB is of great interest. This review provides an overview of the current knowledge on 8-OH-2dG as a biomarker for SPTB and aims to elucidate its mechanism in this condition.展开更多
Supercritical fluids play a crucial role in material transport within Earth's deep interior.Investigating the pressure-dependent atomic structures and transport properties of such fluids is essential for understan...Supercritical fluids play a crucial role in material transport within Earth's deep interior.Investigating the pressure-dependent atomic structures and transport properties of such fluids is essential for understanding their petrological,chemical,and geophysical behaviors.In this study,we employed first-principles molecular dynamics simulations to explore the structures,self-diffusion coefficients(D),and viscosities(η)of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids under conditions of 2000 K and 3-10 GPa,with water contents of 30 wt% and 50 wt%.Our calculations indicate that at a water content of 30 wt%,Q^(2) and Q^(3) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species(n represents the number of bridging oxygens connected to Si/Al)show minimal changes.At a water content of 50 wt%,Q^(2) and Q^(0) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species show minimal changes.At both water contents,Si-O-H and molecular water in the system exhibit negative pressure dependence,suggesting that the migration of supercritical fluids from deep to shallow regions is accompanied by the release of water.The self-diffusion coefficients in the supercritical NaAlSi_(3)O_(8)-H_(2)O fluid follow the order D_(Na)≈D_(H)>D_(O)>D_(Al)≈D_(Si),with an overall weak negative pressure dependence.By comparing the viscosities of anhydrous and hydrous silicate melts from previous studies,we found that the addition of water caused a transition from negative to positive pressure dependence of viscosity,corresponding to a structural change from polymerization to depolymerization.Additionally,we calculated the fluid mobility Δp/η of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids and found that their mobility is several orders of magnitude higher than that of basalt melt and is also significantly greater than that of carbonate melt.As supercritical fluids ascend from deeper to shallower regions,their mobility is further enhanced,significantly contributing to the transport of elements from subducting slabs to the overlying mantle wedge.展开更多
A composite film of DNA/poly(3-methylthiophene)(P3MT)modified glassy carbon electrode(GCE)has been fabricated by electro-deposition method.P3MT film was first electropolymerized at the GCE and the DNA layer was then i...A composite film of DNA/poly(3-methylthiophene)(P3MT)modified glassy carbon electrode(GCE)has been fabricated by electro-deposition method.P3MT film was first electropolymerized at the GCE and the DNA layer was then immobilized on the P3MT layer by electrochemical method.The voltammetric behavior of 8-hydroxy-2'-deoxyguanosine(8-OH-dG)at the composite film modified electrode was studied.The effects of scan rates,pH and the interference of uric acid(UA)on the voltammetric behavior and detection of 8-OH-dG were also discussed.The experimental results suggest that the electrochemical behavior of 8-OH-dG at the composite film modified electrode was greatly improved due to the combination of the advantages of P3MT and DNA.In 0.1 M pH 7.0 phosphate buffer solution(PBS),the anodic peak currents of 8-OH-dG were linear with the 8-OH-dG concentration in two intervals,viz.0.28―4.2μM and 4.2―19.6μM.The detection limit of 56 nM 8-OH-dG could be estimated(S/N=3).This proposed composite film modified electrode shows excellent reproducibility and stability.It may have the potential application for the detection of 8-OH-dG in human urine.展开更多
基金the support of the National Natural Science Foundation of China(No.20575051).
文摘Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with conv...
基金funded by the Natural Science Foundation of Technology Department of Liaoning Province, No.20032047
文摘Previous studies have reported a neuroprotective effect of 8-hydroxy-2-（di-n-propylamino）tetralin （8-OH-DPAT） against traumatic brain injury. In accordance with the Marmarou method, rat models of diffuse axonal injury were established. 8-OH-DPAT was intraperitoneally injected into model rats. 8-OH-DPAT treated rats maintained at constant temperature served as normal temperature controls TUNEL results revealed that neural cell swelling, brain tissue necrosis and cell apoptosis occurred around the injured tissue. Moreover, the number of Bax-, Bcl-2- and caspase-3-positive cells increased at 6 hours after diffuse axonal injury, and peaked at 24 hours. However, brain injury was attenuated, the number of apoptotic cells reduced, Bax and caspase-3 expression decreased, and Bcl-2 expression increased at 6, 12, 24, 72 and 168 hours after diffuse axonal injury in normal temperature control and in 8-OH-DPAT-intervention rats. The difference was most significant at 24 hours. All indices in 8-OH-DPAT-intervention rats were better than those in the constant temperature group. These results suggest that 8-OH-DPAT inhibits Bax and caspase-3 expression, increases Bcl-2 expression, and reduces neural cell apoptosis, resulting in neuroprotection against diffuse axonal injury. This effect is associated with a decrease in brain temperature.
基金Nature Science Fundation of Jiangsu Province (BK2004146)Science Fund of Department of Education of Jiangsu Province (03KJB310085)
文摘Reactive oxygen species may be involved in the progression of gastric carcinomas. To clarify whether the pathology of gastric carcinoma are related to oxidative DNA damage, the expression of 8-hydroxy-2＇-deoxyguanosine （8-OHdG） was examined in 30 patients with gastric carcinomas. Methods： The expression of 8-OHdG and apoptosis in the gastric carcinoma were measured using the methods of immunocytochemistry and deoxynucleartididyl transferase-mediated dUTP-biotin nick end labeling （TUNEL）, respectively. Results： Of the 30 cases, 25（83%） showed stronger immunoreactivity than normal control. The patients with poorly differentiated gastric carcinoma had a larger tumor size and higher labeling indices of TUNEL- and 8-OHdG-positive cells than those with well and moderately differentiated gastric carcinoma. Conclusion： Our findings suggest that oxidative DNA damage is increased in association with necroinflammation in chronic gastric injuries and determination of 8-OHdG is useful in assessing high-grade malignancy in gastric carcinomas.
文摘8-hydroxy-2’-deoxyguanosine (8-OHdG), a typical form ofDNA adducts, is a key molecular biomarker for DNA oxidativedamage. The aim of the present study was to evaluote the correla-tion between the sperm DNA 8-OHdG level and the semen quality.In 52 male infertile patients, the sperm DNA 8-OHdG level wasdetermined by a high performance liquid chromatograph with elec-trochemical detector and the semen quality was examined according
文摘Spontaneous preterm birth (SPTB) is characterized by the delivery of a baby before 37 completed weeks of gestation, and this condition is associated with significant health challenges for the newborn. Emerging evidence highlights the importance of biomarkers for understanding the mechanisms underlying SPTB. One such biomarker, 8-OH-2dG, plays a critical role in evaluating oxidative stress and its impact on pregnancy outcomes. It has been demonstrated that 8-OH-2dG is a product of oxidative DNA damage and is widely recognized as a key indicator of cellular oxidative stress. Elevated reactive oxygen species in SPTB result in higher levels of the DNA degradation product 8-OH-2dG in amniotic fluid, causing damage to maternal and fetal tissues that could lead to premature rupture of fetal membranes. Therefore, evaluating the role of 8-OH-2dG in SPTB is of great interest. This review provides an overview of the current knowledge on 8-OH-2dG as a biomarker for SPTB and aims to elucidate its mechanism in this condition.
基金funded by National Natural Science Foundation of China(42373033,Yicheng Sun)Fundamental Research Funds for the Central Universities(B240201111,Yicheng Sun)。
文摘Supercritical fluids play a crucial role in material transport within Earth's deep interior.Investigating the pressure-dependent atomic structures and transport properties of such fluids is essential for understanding their petrological,chemical,and geophysical behaviors.In this study,we employed first-principles molecular dynamics simulations to explore the structures,self-diffusion coefficients(D),and viscosities(η)of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids under conditions of 2000 K and 3-10 GPa,with water contents of 30 wt% and 50 wt%.Our calculations indicate that at a water content of 30 wt%,Q^(2) and Q^(3) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species(n represents the number of bridging oxygens connected to Si/Al)show minimal changes.At a water content of 50 wt%,Q^(2) and Q^(0) exhibit a certain degree of positive and negative pressure dependence,respectively,while other Q^(n) species show minimal changes.At both water contents,Si-O-H and molecular water in the system exhibit negative pressure dependence,suggesting that the migration of supercritical fluids from deep to shallow regions is accompanied by the release of water.The self-diffusion coefficients in the supercritical NaAlSi_(3)O_(8)-H_(2)O fluid follow the order D_(Na)≈D_(H)>D_(O)>D_(Al)≈D_(Si),with an overall weak negative pressure dependence.By comparing the viscosities of anhydrous and hydrous silicate melts from previous studies,we found that the addition of water caused a transition from negative to positive pressure dependence of viscosity,corresponding to a structural change from polymerization to depolymerization.Additionally,we calculated the fluid mobility Δp/η of supercritical NaAlSi_(3)O_(8)-H_(2)O fluids and found that their mobility is several orders of magnitude higher than that of basalt melt and is also significantly greater than that of carbonate melt.As supercritical fluids ascend from deeper to shallower regions,their mobility is further enhanced,significantly contributing to the transport of elements from subducting slabs to the overlying mantle wedge.
基金Supported by the National Natural Science Foundation of China(Grant Nos.20475024&20775031)the Shandong Tai-Shan Scholar Research Fund
文摘A composite film of DNA/poly(3-methylthiophene)(P3MT)modified glassy carbon electrode(GCE)has been fabricated by electro-deposition method.P3MT film was first electropolymerized at the GCE and the DNA layer was then immobilized on the P3MT layer by electrochemical method.The voltammetric behavior of 8-hydroxy-2'-deoxyguanosine(8-OH-dG)at the composite film modified electrode was studied.The effects of scan rates,pH and the interference of uric acid(UA)on the voltammetric behavior and detection of 8-OH-dG were also discussed.The experimental results suggest that the electrochemical behavior of 8-OH-dG at the composite film modified electrode was greatly improved due to the combination of the advantages of P3MT and DNA.In 0.1 M pH 7.0 phosphate buffer solution(PBS),the anodic peak currents of 8-OH-dG were linear with the 8-OH-dG concentration in two intervals,viz.0.28―4.2μM and 4.2―19.6μM.The detection limit of 56 nM 8-OH-dG could be estimated(S/N=3).This proposed composite film modified electrode shows excellent reproducibility and stability.It may have the potential application for the detection of 8-OH-dG in human urine.
