In the present study, the authors attempted to shed a light on the possible relationships between lipid per oxidation markers, serum malondialdehyde （MDA） with the effect of mercury exposure using serum samples obta...In the present study, the authors attempted to shed a light on the possible relationships between lipid per oxidation markers, serum malondialdehyde （MDA） with the effect of mercury exposure using serum samples obtained from 100 mercury exposed dentals due to their occupation. These dentals were divided into two groups according to their occupational period. The third group consists of healthy volunteers that were working outside the mercury factories as a control group. The present results showed that mercury levels increased with the increasing of their occupation period. The highest level was 5.7 μg/dl, compared to the control group which was 0.1 μg/dl., The level of MDA was elevated in the workers and the highest level was found to be 41.00 nmol/dL for workers with longest period compared to the control group 8.6 nmol/dL. Some serum antioxidants such as vitamin A, E and albumin were evaluated and were found to be lower in all workers compared to the control group. The present results showed that Mg levels increased with the increasing of their occupation period and were found to be lower in Zn, Se of all workers compared to the control group.展开更多
The effect of N levels and sources on the antioxidant components in vegetable is not completely understood. Therefore, greenhouse experiments were conducted to determine the changes in antioxidant capacity diphenyl-2-...The effect of N levels and sources on the antioxidant components in vegetable is not completely understood. Therefore, greenhouse experiments were conducted to determine the changes in antioxidant capacity diphenyl-2-picrylhydrazyl （DPPH） and ferric reducing antioxidant power （FRAP）, total phenolics, ascorbic acid, total carotene and lycopene contents in edible portions of lettuce, onion and tomato due to different nitrogen levels and sources. The experiment included three N levels （20, 40 and 60 kg/ha for lettuce trial and 60, 120 and 180 kg/ha for either onion or tomato） and four nitrogen sources （calcium nitrate, ammonium sulphate, ammonium nitrate and urea）. The antioxidant capacity and phenolic contents in lettuce was enhanced under low nitrogen level, while the antioxidant capacities, phenolics, carotenoids and lycopene in tomato fruits were not significantly affected by the nitrogen dose applied. Application of calcium nitrate caused 50% increase in DPPH and 20% in FRAP of lettuce compared to other nitrogen forms. Tomato treated with calcium nitrate or ammonium sulphate had higher phenolic and ascorbic acid contents than treated plants with ammonium nitrate or urea. Antioxidant tested parameters of onion were not significantly affected by the nitrogen treatments. Nitrogen concentration in tomato fruits significantly correlated with FRAP antioxidant capacity, phenolics, ascorbic acid, carotene and lycopene contents.展开更多
Objective:To determine whether endothelial dysfunction leads to an abnormal responsiveness of platelet to nitric oxide(NO)during the development of atherosclerosis. Methods:Rabbits were fed a 1% cholesterol chow for ...Objective:To determine whether endothelial dysfunction leads to an abnormal responsiveness of platelet to nitric oxide(NO)during the development of atherosclerosis. Methods:Rabbits were fed a 1% cholesterol chow for 12 weeks to induce atherosclerosis.Serum NOx levels and the responsiveness of platelet to NO donor SNP were determined every 4 weeks during maintaining on a chow containing 1% cholesterol.The measurement of serum lipids and the examination of morphological feature and endothelial-dependent relaxation of aorta were performed after 12 weeks of cholesterol diet. Results:Cholesterol diet significantly increased serum levels of cholesterol and LDL,caused a remarkable platelet hyperaggregability,and produced an evident endothelial dysfunction as indicated by the diminished vasorelaxation induced by acetylcholine and endothelial cell lesion as exhibited by scanning electron microscope examination.The percentage of inhibition of ADP-induced platelet aggregation by NO donor SNP was significantly smaller in cholesterol chow group than that in normal chow group although no significant difference in serum NOx levels between normal and cholesterol chow group was observed throughout the development of atherosclerosis. Conclusion:The present study suggests that the endothelial dysfunction caused by enhanced serum cholesterol and LDL levels induces a decreased responsiveness of platelet to NO.展开更多
Cyanobacterial blooms are ubiquitous in fresh and brackish eutrophic waters in India. The cyanotoxins produced by many bloom forming cyanobacteria severely affect the health of animals, fishes, birds and human beings....Cyanobacterial blooms are ubiquitous in fresh and brackish eutrophic waters in India. The cyanotoxins produced by many bloom forming cyanobacteria severely affect the health of animals, fishes, birds and human beings. Different physical and chemical factors contribute towards bloom formation. Ten bloom forming cyanobacteria were isolated from natural blooms of northern India. The strains were purified and enriched in the laboratory. The aim of this study was to understand the influence of iron on growth, pigmentation and antioxidative activity of enzymes-catalase and ascorbate peroxidase of bloom forming cyanobacteria. Results show that different strains of bloom forming cyanobacteria attain optimum growth at varied concentration of iron. The cyanobacterial strains like Synechocystis aquatalis, Merismopedia glauca, Anabaena variabilis and Anabaena iyengarii exhibit maximum growth at low iron concentration （2 pM） while some species require higher concentration of iron for their optimum growth namely, Arthrospira platensis show optimum growth at 10uM, and Nostocpaludosum shows maximum growth at 100uM concentration of iron. It was also noticed that chlorophyll and phycobiliprotein content also varies with change in iron concentration. The activity of antioxidative enzymescatalase and ascorbate peroxidase was noticed in all ten cyanobacterial strains. In the light of the findings, it seems that Arthrospira platensis possess maximum catalase and ascorbate peroxidase activity. Increment in concentration beyond optimum value leads to deterioration in the growth, pigment content and enzymatic activity of the cyanobacterial strains. Knowledge about the factors influencing growth of bloom forming cyanobacteria will help to work out ways for eradication of hazardous cyanobacterial blooms.展开更多
文摘In the present study, the authors attempted to shed a light on the possible relationships between lipid per oxidation markers, serum malondialdehyde （MDA） with the effect of mercury exposure using serum samples obtained from 100 mercury exposed dentals due to their occupation. These dentals were divided into two groups according to their occupational period. The third group consists of healthy volunteers that were working outside the mercury factories as a control group. The present results showed that mercury levels increased with the increasing of their occupation period. The highest level was 5.7 μg/dl, compared to the control group which was 0.1 μg/dl., The level of MDA was elevated in the workers and the highest level was found to be 41.00 nmol/dL for workers with longest period compared to the control group 8.6 nmol/dL. Some serum antioxidants such as vitamin A, E and albumin were evaluated and were found to be lower in all workers compared to the control group. The present results showed that Mg levels increased with the increasing of their occupation period and were found to be lower in Zn, Se of all workers compared to the control group.
文摘The effect of N levels and sources on the antioxidant components in vegetable is not completely understood. Therefore, greenhouse experiments were conducted to determine the changes in antioxidant capacity diphenyl-2-picrylhydrazyl （DPPH） and ferric reducing antioxidant power （FRAP）, total phenolics, ascorbic acid, total carotene and lycopene contents in edible portions of lettuce, onion and tomato due to different nitrogen levels and sources. The experiment included three N levels （20, 40 and 60 kg/ha for lettuce trial and 60, 120 and 180 kg/ha for either onion or tomato） and four nitrogen sources （calcium nitrate, ammonium sulphate, ammonium nitrate and urea）. The antioxidant capacity and phenolic contents in lettuce was enhanced under low nitrogen level, while the antioxidant capacities, phenolics, carotenoids and lycopene in tomato fruits were not significantly affected by the nitrogen dose applied. Application of calcium nitrate caused 50% increase in DPPH and 20% in FRAP of lettuce compared to other nitrogen forms. Tomato treated with calcium nitrate or ammonium sulphate had higher phenolic and ascorbic acid contents than treated plants with ammonium nitrate or urea. Antioxidant tested parameters of onion were not significantly affected by the nitrogen treatments. Nitrogen concentration in tomato fruits significantly correlated with FRAP antioxidant capacity, phenolics, ascorbic acid, carotene and lycopene contents.
文摘Objective:To determine whether endothelial dysfunction leads to an abnormal responsiveness of platelet to nitric oxide(NO)during the development of atherosclerosis. Methods:Rabbits were fed a 1% cholesterol chow for 12 weeks to induce atherosclerosis.Serum NOx levels and the responsiveness of platelet to NO donor SNP were determined every 4 weeks during maintaining on a chow containing 1% cholesterol.The measurement of serum lipids and the examination of morphological feature and endothelial-dependent relaxation of aorta were performed after 12 weeks of cholesterol diet. Results:Cholesterol diet significantly increased serum levels of cholesterol and LDL,caused a remarkable platelet hyperaggregability,and produced an evident endothelial dysfunction as indicated by the diminished vasorelaxation induced by acetylcholine and endothelial cell lesion as exhibited by scanning electron microscope examination.The percentage of inhibition of ADP-induced platelet aggregation by NO donor SNP was significantly smaller in cholesterol chow group than that in normal chow group although no significant difference in serum NOx levels between normal and cholesterol chow group was observed throughout the development of atherosclerosis. Conclusion:The present study suggests that the endothelial dysfunction caused by enhanced serum cholesterol and LDL levels induces a decreased responsiveness of platelet to NO.
文摘Cyanobacterial blooms are ubiquitous in fresh and brackish eutrophic waters in India. The cyanotoxins produced by many bloom forming cyanobacteria severely affect the health of animals, fishes, birds and human beings. Different physical and chemical factors contribute towards bloom formation. Ten bloom forming cyanobacteria were isolated from natural blooms of northern India. The strains were purified and enriched in the laboratory. The aim of this study was to understand the influence of iron on growth, pigmentation and antioxidative activity of enzymes-catalase and ascorbate peroxidase of bloom forming cyanobacteria. Results show that different strains of bloom forming cyanobacteria attain optimum growth at varied concentration of iron. The cyanobacterial strains like Synechocystis aquatalis, Merismopedia glauca, Anabaena variabilis and Anabaena iyengarii exhibit maximum growth at low iron concentration （2 pM） while some species require higher concentration of iron for their optimum growth namely, Arthrospira platensis show optimum growth at 10uM, and Nostocpaludosum shows maximum growth at 100uM concentration of iron. It was also noticed that chlorophyll and phycobiliprotein content also varies with change in iron concentration. The activity of antioxidative enzymescatalase and ascorbate peroxidase was noticed in all ten cyanobacterial strains. In the light of the findings, it seems that Arthrospira platensis possess maximum catalase and ascorbate peroxidase activity. Increment in concentration beyond optimum value leads to deterioration in the growth, pigment content and enzymatic activity of the cyanobacterial strains. Knowledge about the factors influencing growth of bloom forming cyanobacteria will help to work out ways for eradication of hazardous cyanobacterial blooms.
