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Objective In this study,we investigated the relationship between oxidative stress,selenoproteins level and onset of Keshan disease (KD) through detecting the expression of 8-hydroxy-2-deoxy guanosine (8-OH-dG),thioredoxin reductase 1 (TrxR1) and glutathione peroxidase 1 (GPx1) in myocardial tissue.Methods Myocardium samples of autopsy patients including 8 cases of KD (KD group included 4 acute KD and 4 chronic KD) and 9 cases of non-KD (control group) were immunohistochemically stained for 8-OH-dG,TrxR1 and GPx1.The staining intensities subsequently quantified by using Olympus Image-Pro Plus 6.0 software.Results The positive rate of 8-OH-dG expression in myocardial nuclei was higher in the case group[(68.6 ± 20.4)％] than that of the control group[(2.4 ± 1.5)％,t =8.515,P ＜ 0.05].In addition,the positive rate of 8-OH-dG expression in acute KD[(91.7 ± 3.7)％] was significantly higher than that of chronic KD[(53.2 ± 7.9)％,t =6.409,P＜0.05].The distribution of TrxR1 and GPx1 was not associated with the distribution of myocardial damage.The expression of these two selenoproteins in KD group (401340 ± 59865,497590 ± 197082) were both lower than that of control group(2790300 ± 379298,1348400 ±615840; t =-28.493,-6.016,respectively,all P＜0.01).Conclusions Oxidative damage is detected in myocardium tissue of KD,and 8-OH-dG expression is associated with the degree of myocardial damage in KD.Selenoproteins,TrxR1 and GPx1,may be closely related to the pathogenesis of KD.
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ObjectiveTo explore the effect of selenium,protein and vitamin E deficiency on mRNA expression of rat cardiac selenoprotein,and their relation with myocardial injury.MethodsForty male Wistar rats were randomly divided into 4 groups:low selenium low protein low vitamin E group(group A),low selenium low protein adequate vitamin E group(group B),adequate selenium adequate protein low vitamin E group(group C),and adequate selenium adequate protein adequate vitamin E group (group D),10 rats in each group.The activity of whole blood glùtathione peroxidase(GSH-Px ) was measured using dithiobis nitrobenzoic acid (DTNB) at the end of sixth month experiment.The levels of mRNA expression of glutathione peroxidase 1(Gpx1),phospholipid hydroperoxide glutathione peroxidase 4(Gpx4),thioredoxin reductase(TrxR),selenoprotein P(Se-P) and selenoprotein W(Se-W) were determined by real-time fluorescence quantitative PCR at the end of sixth month.Histopathological changes of myocardial injury were observed with light microscope.ResultsThe activity of GSH-Px was (44.6 ± 3.1 ),(45.5 ± 1.6),(86.6 ± 2.2),(85.6 ± 1.2)U/L,respectively,in the above four groups at the end of sixth month,and the difference was statistically significant(F =100.7,P ＜ 0.01 ) ; the activity of GSH-Px of groups C and D was higher than that of groups A,B(all P ＜ 0.05).mRNA expression of myocardial tissue of the four groups was as follows,Gpx1(0.099 ± 0.312,0.054 ± 0.007,0.386 ± 0.067,0.340 ± 0.085),Gpx4(1.005 ± 0.089,0.810 ± 0.229,0.895 ± 0.084,0.922 ± 0.399),and Se-W(0.188 ± 0.080,0.119 ± 0.069,0.574 ± 0.167,0.570 ± 0.383),and the difference was statistically significant(F =112.1,3.76,22.8,all P ＜ 0.05) ; the mRNA levels of Gpx1,Se-W of groups C,D were significantly higher than that of groups A,B(all P ＜ 0.05).The mRNA expression of Gpx4 of group A was higher than that of group C(P ＜ 0.05).The mRNA expression of TrxR(0.130 ± 0.037,0.127 ± 0.038,0.134 ± 0.021,0.120 ± 0.014) and Se-P(0.446 ± 0.155,0.413 ± 0.152,0.385 ± 0.041,0.408 ±0.208 ) was not statistically different among the four groups (F =0.91,1.75,all P ＞ 0.05).Pathological changes of myocardial tissue were mainly as foci of coagulative necrosis.The necrosis detection rate of the four groups was 8/10,4/9,2/10,and 1/10,respectively,and the difference was significant statistically(Fisher exact test,P =0.0067).ConclusionsLong-term selenium,protein and vitamin E deficiency will reduce body antioxidant capacity and lead to myocardial injury.The mRNA levels of Gpx1 and Se-W and selenium level are closely related.The mRNA levels of Gpx4,TrxR and Se-P remain relatively stable.
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Objective To study the effects of selenium(Se) and protein on cardiac morphology and expression of cellular glutathione peroxidase(GPX1 ) and mitochondrial thioredoxin reductase(TR2) in rat myocardial tissue.MethodsSixty healthy weaning male Wistar rats were randomly divided into four groups by two factors two levels factorial design(n =15).Drinking water was divided into two levels of Se-deficient(0 mg/L) and Se-adequate (0.25 mg/L); diet was divided into two levels of protein-deficeient (10％ protein and 0.008 mg/kg Se) and protein-adequate(20％ protein and 0.015 - 0.026 mg/kg Se).The rats were killed after feeding for one year.Pathological changes in myocardial tissues were observed under light microscope.The expression of GPX1 and TR2 in rat myocardial tissue was detected by immunohistochemistry and Western blotting.Results Compared between groups,the difference of the rate of myocardial necrosis in rats was statistically significant(x2 =11.04,P ＜ 0.05),in which Se-deficient protein-deficient group [66.7％ (8/12) ] was significantly higher than Se-adequate proteinadequate group [ 7.1％ ( 1 / 14),x2 - 11.06,P ＜ 0.05 ].GPX 1 positive rates in Se-deficient protein-deficient group,Se-adequate protein-deficient group,Se-deficient protein-adequate group and Se-adequate protein-adequate group were 0(0/12),81.8％(9/11 ),10.0％(1/10) and 100.0％(14/14),respectively,in rat myocardial tissue determined by immunohistochemistry.Of which,Se-adequate protein-deficient group and Se-adequate protein-adequate group were significantly higher than Se-deficient protein-deficient group and Se-deficient protein-adequate group(x2 =12.88,8.14 and 35.89,32.60,all P ＜ 0.05).The positive expression rates of TR2 in rats myocardial tissue of the four groups were 0(0/12),81.8％(9/11),0(0/10) and 100.0％(14/14),respectively.Of which,Se-adequate proteindeficient group and Se-adequate protein-adequate group were significantly higher than Se-deficient protein-deficient group and Se-deficient protein-adequate group (x2 =28.67,18.25 and 35.89,32.60,all P ＜ 0.05).The four groups'results of the overall mean of the relatively value of protein expression of GPX1 in cardiac tissue by Western blotting were 0.87 ± 0.13,1.18 ± 0.13,0.95 ± 0.13 and 1.74 ± 0.23,respectively.Through analysis of variance of factorial design,the effects of Se and protein on protein expression of GPX1 in the heart were statistically significant(F=124.93,43.16,all P＜ 0.05).And there was interaction between them(F=24.10,P＜ 0.05).The four groups'results of the overall mean of the relatively value of protein expression of TR2 in cardiac tissue by Western blotting were 0.63 ± 0.19,0.97 ± 0.24,0.55 ± 0.08 and 1.03 ± 0.31,respectively.Through analysis of variance of factorial design,the effect of Se on expression of TR2 in the heart was statistically significant(F =36.97,P ＜ 0.05).Conclusions Adequate Se and protein diet can increase the levels of GPX1 and TR2 in the heart compared to deficient Se and protein diet,can enhance anti-oxidizing ability,protect the myocardial endothelial cells,reduce degree of myocardial injury,and the combined effects of both are better.
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Objective To observe protective effects on rat serum cardiac enzymes and the antioxidant capacity of selenium and vitamin E.Methods According to body weight and 2 × 2 factorial design,eighty male Wistas rats were randomly divided into four groups:low selenium and low vitamin E group(feed containing 23.42％ of the low selenium yeast,excluding vitamin E),low selenium and adequate vitamin E group (feed containing 23.42％ of the low selenium yeast and vitamin E 160 mg/kg),adequate selenium and low vitamin E group(feed containing 46.84％ of the low selenium yeast and sodium seleni 0.25 mg/L in water,excluding vitamin E),adequate selenium and adequate vitamin E group(feed containing 46.84％ of the low selenium yeast,vitamin E 160 mg/kg and sodium selenite 0.25 mg/L in water),20 rats every group.Rats were feed with synthetic feed,and given intraperitoneal anesthesia after 26 weeks of feeding.Blood was collected to observe the impact of selenium and vitamin E on rat cardiac enzymes and myocardial antioxidant capacity and their interactions.Serum creatine kinase (CK) was measured using the continuous monitoring method,creatine kinase isozymes (CK-MB) and lactate dehydrogenase(LDH ) using the immune suppression method,the whole blood GSH-Px assay using the dithiobis nitrohenzoic acid(DTNB) method,serum superoxide dismutase(SOD) using the xanthine oxidase method,total antioxidant capacity (T-AOC) using the complex colorimetry method,the content of propylene glycol (MDA) using the thiobarbituric acid colorimetric method,and reactive oxygen species(ROS) using the colorimetric method.Results Group differences of serum CK,CK-MB,LDH,whole blood GSH-Px activity,serum T-AOC vitality,MDA and ROS content were statistically significant(F=9.797,17.041,48.399,3.744,224.900,49.384,5.045,all P＜ 0.05).Compared with the two low selenium groups and one adequate selenium group,the vitalities of CK,CK-MB,LDH and the contents of MDA[(1577.75 ± 451.87),(1239.15 ± 344.99),(884.25 ± 133.84)U/L,(5.688 ±1.169) × 103 nmol/L; (1474.21 ± 398.38),(1014.84 ± 215.40),(523.00 ± 98.05)U/L,(4.035 ± 0.487 ) × 103 nmol/L and (1180.10 ± 245.51),(948.75 ± 173.68),(676.70 ± 193.63)U/L,(3.406 ± 0.146) × 103 nmol/L]increased significantly in adequate selenium and adequate vitamin E group[( 1056.80 ± 250.98),(721.70 ±129.98),(404.65 ± 72.49)U/L,(3.010 ± 1.270) × 103 nmol/L,all P ＜ 0.05) ].The activity of GSH-Px was obviously increased in the two adequate selenium groups[ (96.611 ± 8.238) × 103,(103.024 ± 8.217) × 103 U/L,all P ＜ 0.05],compared with the two low selenium groups[ (60.356 ± 8.179) × 103,(63.117 ± 8.281) × 103 U/L].Selenium affected the activities of CK,CK-MB and LDH(F =27.09,31.58,29.66,all P＜ 0.01 ),and vitamin E affected the activities of CK-MB and LDH(F=18.9,11.2.all P＜ 0.01 ),but both selenium and vitamin E had no interactions on the activities of CK,CK-MB and LDH (F=0.02,0.001,2.22,all P＞0.05).Selenium affected the activity of GSH-Px and the content of MDA(F=6.74,95.68,all P＜ 0.05),vitamin E affected the activity of T-AOC,the contents of MDA and ROS(F=6.42,36.73,8.43,all P＜0.05),but selenium and vitamin E had interactions only on the content of MDA(F =13.82,P＜ 0.05).Conclusions Long-term selenium or vitamin E deficiency,can reduce the body's antioxidant capacity,leading to the occurrence of myocardial injury.Selenium and vitamin E can improve the body's oxidation capacity,playing a role in myocardial protection.
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Objective To explore the relationship between myocardial damage and antioxidant capacity in vivo of Keshan disease patients and to analyze the possible pathogenesis. Methods In the period from 2005 to 2006, 41 chronic and latent Keshan disease cases were chosen as the case group from such serious endemic areas as Yongjin Village, Xinfa Village of Fuyu County, Fuan Village of Shangzhi County, Xinghuo Village of Wudalianchi County, 61 healthy people from the same area as internal controls, 48 healthy people from Xianglansan Village of Wangkui County, an un-endemic area, as external control. Fasting peripheral venous blood was collected from all the people. And blood selenium, glutathione peroxidase(GSH-Px) and suporoxide dismutase.(T-SOD) activities, malondialdehyde (MDA) levels were examined. Results Blood selenium level of the patient group [(34.80±13.30) μg/L], GSH-Px[(104.10±34.19)U/L]and T-SOD[(92.16±17.98)×103 U/L]actives were significantly lower than the internal control group [(41.24±13.57)μg/L, (118.57±25.49)U/L, (104.82±13.56)×103 U/L]and the external control group [(48.33±16.51)μg/L, (155.00±24.01)U/L, (108.48±12.73)×103 U/L], respectively, with a statistically significant difference(all P < 0.05). MDA level of the patient group[(7.12± 1.37)μmol/L]was higher than that in the internal control group[(5.36±1.18)μmol/L]and the external control group[(5.22±0.83)μmol/L]with a statistically significant differences(both P < 0.05). The blood selenium level, GSH-Px activity of internal control group was resoectively lower than that in the external control group, the differences being statistically significant(beth P < 0.05). Conclusions Selenium deficiency may lead to reduced antioxidant capacity and enhanced oxidative damage in Keshan disease patients in vivo. There may be a certain relationship between oxidative stress disorder and myocardial damage of Keshan disease.
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Objective To investigate the myocardial damage in rats fed with corn from Keshan disease area added with bean puree. Methods Male Wistar rats were randomly divided into 3 groups according to their body weights, and fed with corn, corn from Keshan disease area added with bean puree, corn from non-endemic area. The GSH-Px activity of vena cardalis blood was examined in 1 and 3 months, rats were sacrificed after being fed for 6 months to examine the heart changes with HE stain. Results The three groups of GSH-Px activity were different in 1 and 3 months respectively(F=23.60,72.46, all P<0.01); GSH-Px activity was (181.58±22.15), (44.76±28.59)U/L in rats fed with corn, was (195.03±17.66), (30.38±3.35)U/L in those fed with corn added with bean puree from Keshan disease area, lower than the group fed with corn of non-endemic area[(340.90±95.42), (125.17±13.64)U/L, all P < 0.01]. But the difference of GSH-Px activity between simple corn group and corn adding bean puree groups of Keshan disease area was not obvious(P>0.05). Myocardial damage incidence of the three groups was 3/9,1/9,2/7. Difference among three groups did not have statistical significance(χ2=1.33, P> 0.05). Conclusions Only corn from Keshan disease area may induce myocardial damage pathology change. Adding bean puree into corn does not increase damage.
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Objective To explore the potential risk factors to Ymman endemic sudden cardiac death (YESCD) and provide evidence for prevention. Methods Twenty-two cases and 24 controls were randomly selected from YESCD areas and non-YESCD areas, respectively. Both cases and controls were interviewed with unified questionnaires. Univatiate X2 test and multivariate conditional logistic stepwise regression was conducted with SPSS 13.0. The optimal regression model was established and evaluated. Results The univariate X2 teat revealed that presence or absence of 5 potential factors might possibly be associated to YESCD: appropriate places for storing dining utensils, pens for livestock, consumption of mushrooms, exposure to any pesticides, and sudden climate changes before onset(X2=12.206,4.779,5.741,6.120,10.754, P<0.05). Multivariate conditional logistic stepwise regression demonstrated that consumption of mushrooms was a protective factor(OR=0.115, P<0.05) and sudden climate change was a risk factor(OR=36.592, P<0.01). Conclusions Sudden climate change might be a risk factor contributing to YESCD, and eating mushrooms before the prevalence seasons may provide some protection.
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Objective Using flowing injection hydride generation atomic fluotometric method(FI-HG- AFM)to detect the whole blood selenium content.Methods A series of standard selenium(1,2,4,6,8.10μg/L) were dectecte by FI-HG-AFM,and the precision and accuracy of the method were observed.The selenium contents of 89 blood samples were detected by FI一HG-AFM and 2,3-diaminonaphthalene fluorometric method(DFM) respectively,and the correlation of two methods Was analyzed.Results The detection limit and recovery rate of FI-HG-AFM were 0.138μg/L and 96.4%,respectively.The relative standard deviation(RSD)was maximized at 1 μg/L(4.406%).The RSD diminished along with the increase of the concentration,and it declined to 0.512%at 10 μg/L.There wag no significant difference(t=1.7878,P>0.05)between the result8 of FI-HG-AFM[(45.9± 14.5)μg/L]and DFM[(47.5 ±13.3)μg/L],and the two methods were in highly positive correlation(r=0.8143,P< 0.01).Conclusions The whole blood selenium content call be rapidly and exactly detected by FI-HG-AFM,and the method are highly consistent with DFM.
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Objective To investigate the influence of acupuncture on Nestin expression in the cerebral cor- tex of hypoxia-ischemic neonatal rats.Methods A total of 72 Sprague-Dawley(SD)rats aged 7 days were random- ly divided into three groups:A normal group(n=24),the hypoxic-ischemic encepbalopathy(HIE)group(n=24), and an acupuncture+HIE group(n=24).The rats were sacrificed at time points including 3d,7d,14d and 28d af- ter insult,their brains were removed and sections were made.Any nerve stem cells(NSCs)in the cerebral cortex were detected using immunohistochemical staining of Nestin.Results Nestin-positive cells were found in the cere- bral cortex in the normal neonatal SD rats early after birth.After HI insult,the Nestin-positive cells had increased in the injured areas of the cortex and in contralateral mirror areas,especially around the injured areas.Peak Nestin ex- pression was 3 days after insult.In the acupuncture+HIE group,Nestin positive cells were significantly increased when compared with that in the HIE group,the peak was postponed,and the peak was longer than in the HIE group. The Nestin positive cells decreased,were seldom seen,and were not different among three groups 28 days after the HI insult.Conclusions Endogenous neural stem cells in the cerebral cortex were increased by acupuncture in hy- poxia-ischemic in neonatal rats,and acupuncture made the peak of Nestin expression longer.