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Hao L.-N.,Peoples Hospital of Hebei Province | Zhang X.-D.,Hebei Province Peoples Hospital | Wang M.,Peoples Hospital of Hebei Province | Yang T.,Hebei Medical University | He S.-Z.,301 Hospital
International Journal of Ophthalmology | Year: 2011

AIM: To explore that if peroxy nitrite induced the expression of inducible nitric oxide synthase (iNOS) via nuclear factor-kappa B (NF-κB) pathway in retinal pigment epithelial (RPE) cells and the antagonism of cholecy stokinin octapeptide-8 (Melatonin, CCK-8) in vitro. METHODS: RPE cells were obtained from eyes of C57 BL/6 mouse and divided into control, peroxy nitrite and CCK-8 groups. Control group was treated with saline, peroxy nitrite group was treated with peroxy nitrite, and CCK-8 group was treated with CCK-8 after added with peroxy nitrite. All changes were observered at 6, 12 and 24 hours after treatment. Gene array analysis, Reverse Transcription Poly merase Chain Reaction (RT-PCR) were used to determ ine the expression of inducible nitric oxide synthase (iNOS) mRNA in RPE cells. Western blotting was used to test the apoptosis of RPE cells. Immunofluorescent staining was used to determ ine the NF-κB pathway signal transduction. RESULTS: Compared to the control group, the expression of iNOS mRNA was up-regulated in peroxy nitrite group and down-regulated in CCK-8 group with gene array analysis. Apoptosis was increased in peroxy nitrite group and decreased in CCK-8 group with western blotting. The NF-κB pathway signal transduction was more and more stronger in the peroxy nitrite group. But in CCK-8 group, little stronger could be observed at 12 hours, then weak at 24 hours with immunofluorescent staining (P<0.001). CONCLUSION: This study suggested that apoptosis of RPE cells was partly induced by peroxy nitrite, which may be the new way of oxidative damage to the RPE cells. The NF-κB signal transduction may affect and reinforce apoptosis mediated by peroxy nitrite. CCK-8 decreased apoptosis of RPE cells induced by peroxy nitrite and is a potential agent for therapy of retinopathy. The mechanism of CCK-8 dealing with RPE cells may be related to its direct inhibition of the form ation of iNOS to produce peroxy nitrite and antagnism of damage of peroxy nitrite to the RPE cells. Copyright International Journal of Ophthalmology Press.


Background: Stroke remains a leading cause of death in the United States. While stroke-related mortality in the USA has declined over the past decades, stroke death rates are still higher for blacks than for whites, even at younger ages. The purpose of this study was to estimate the frequency of a lipid core and explore risk factors for its presence in asymptomatic, young-to-middle-aged urban African American adults recruited from inner-city Baltimore, Md., USA. Methods: Between August 28, 2003, and May 26, 2005, 198 African American participants aged 30-44 years from inner-city Baltimore, Md., were enrolled in an observational study of subclinical atherosclerosis related to HIV and cocaine use. In addition to clinical examinations and laboratory tests, B-mode ultrasound for intima-media thickness of the internal carotid arteries was performed. Among these 198, 52 were selected from the top 30th percentile of maximum carotid intima-media thickness by ultrasound, and high-resolution black blood MRI images were acquired through their carotid plaque before and after the intravenous administration of gadodiamide. Of these 52, 37 with maximum segmental thickness by MRI >1.0 mm were included in this study. Lumen and outer wall contours were defined using semiautomated analysis software. The frequency of a lipid core in carotid plaque was estimated and risk factors for lipid core presence were explored using logistic regression analysis. Results: Of the 37 participants in this study, 12 (32.4%) were women. The mean age was 38.7 ± 4.9 years. A lipid core was present in 9 (17%) of the plaques. Seventy percent of the study participants had a history of cigarette smoking. The mean total cholesterol level was 176.1 ± 37.3 mg/dl, the mean systolic blood pressure was 113.1 ± 13.3 mm Hg, and the mean diastolic blood pressure was 78.9 ± 9.5 mm Hg. There were 5 participants with hypertension (13.5%). Twelve (32%) participants had a history of chronic cocaine use, and 23 (62%) were HIV positive. Among the factors investigated, including age, sex, blood pressure, cigarette smoking, C-reactive protein, fasting glucose, triglycerides, serum total cholesterol, coronary calcium, cocaine use, and HIV infection, only total cholesterol was significantly associated with the presence of a lipid core. Conclusions: This study revealed an unexpectedly high rate of the presence of lipid core in carotid plaque and highlights the importance of cholesterol lowering to prevent cerebrovascular disease in this population. Further population-based studies are warranted to confirm these results. Copyright © 2012 S. Karger AG, Basel.


Zhang Y.,Shandong University | Zhang Y.,Capital Medical University | Wang H.,301 Hospital | Wei L.,Shandong Provincial Hospital | And 8 more authors.
Breast Cancer Research and Treatment | Year: 2010

Breast cancer resistance protein (BCRP/ ABCG2), an ATP-binding cassette half transporter, confers multidrug resistance (MDR) to a series of antitumor agents such as mitoxantrone, daunorubicin, SN-38, and topotecan, and often limits the efficacy of chemotherapy. Recent studies have indicated that a putative estrogen response element (ERE) is located in the promoter region of the BCRP gene. However, whether and how BCRP is regulated transcriptionally by toremifene (TOR) remains unknown. In the present study, two plasmid vectors have been designed to express the wild-Type full-length BCRP cDNA enforced driven by its endogenous promoter containing a functional ERE and a constitutive cytomegalovirus (CMV) promoter as control, respectively, which were transfected into estrogenresponsive MCF-7 and estrogen-independent MDA-MB-231 human breast adenocarcinoma cell lines. We showed that toremifene alone significantly downregulated BCRP mRNA and protein levels in estrogen receptor a (ERa)-positiveMCF- 7 cells in a dose-dependent manner, and the inhibitory effect was partially reversed by estrone (E1). Furthermore, gel shift assays demonstrated that specific binding of ERa to the ERE in the BCRP promoter is essential for transcriptional inhibition of BCRP by toremifene. Interestingly, toremifene alone increased the cellular accumulation of mitoxantrone inBCRPtransfected cells, suggesting that TOR indeed inhibits BCRPmediated drug efflux and overcome drug resistance. To the best of our knowledge, this is the first report describing a direct effect of toremifene on BCRP. Our results thus indicate that toremifene by itself downregulates BCRP expression to reverse BCRP-mediated atypical multidrug resistance via a novel transcriptionally mechanism, which might be involved inTOR-ERcomplexes binding to theEREofBCRP promoter to repress transcription of BCRP gene. © Springer Science+Business Media, LLC. 2009.


Califf R.M.,Duke University | McMurray J.J.,University of Glasgow | Holman R.R.,University of Oxford | Haffner S.M.,University of Texas Health Science Center at San Antonio | And 52 more authors.
New England Journal of Medicine | Year: 2010

Background: It is not known whether drugs that block the renin-angiotensin system reduce the risk of diabetes and cardiovascular events in patients with impaired glucose tolerance. Methods: In this double-blind, randomized clinical trial with a 2-by-2 factorial design, we assigned 9306 patients with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors to receive valsartan (up to 160 mg daily) or placebo (and nateglinide or placebo) in addition to lifestyle modification. We then followed the patients for a median of 5.0 years for the development of diabetes (6.5 years for vital status). We studied the effects of valsartan on the occurrence of three coprimary outcomes: the development of diabetes; an extended composite outcome of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, hospitalization for heart failure, arterial revascularization, or hospitalization for unstable angina; and a core composite outcome that excluded unstable angina and revascularization. Results: The cumulative incidence of diabetes was 33.1% in the valsartan group, as compared with 36.8% in the placebo group (hazard ratio in the valsartan group, 0.86; 95% confidence interval [CI], 0.80 to 0.92; P<0.001). Valsartan, as compared with placebo, did not significantly reduce the incidence of either the extended cardiovascular outcome (14.5% vs. 14.8%; hazard ratio, 0.96; 95% CI, 0.86 to 1.07; P = 0.43) or the core cardiovascular outcome (8.1% vs. 8.1%; hazard ratio, 0.99; 95% CI, 0.86 to 1.14; P = 0.85). Conclusions: Among patients with impaired glucose tolerance and cardiovascular disease or risk factors, the use of valsartan for 5 years, along with lifestyle modification, led to a relative reduction of 14% in the incidence of diabetes but did not reduce the rate of cardiovascular events. (ClinicalTrials.gov number, NCT00097786.). Copyright © 2010 Massachusetts Medical Society. All rights reserved.


Holman R.R.,University of Oxford | Haffner S.M.,University of Leicester | Haffner S.M.,University of Texas Health Science Center at San Antonio | McMurray J.J.,University of Glasgow | And 54 more authors.
New England Journal of Medicine | Year: 2010

Background: The ability of short-acting insulin secretagogues to reduce the risk of diabetes or cardiovascular events in people with impaired glucose tolerance is unknown. Methods: In a double-blind, randomized clinical trial, we assigned 9306 participants with impaired glucose tolerance and either cardiovascular disease or cardiovascular risk factors to receive nateglinide (up to 60 mg three times daily) or placebo, in a 2-by-2 factorial design with valsartan or placebo, in addition to participation in a lifestyle modification program. We followed the participants for a median of 5.0 years for incident diabetes (and a median of 6.5 years for vital status). We evaluated the effect of nateglinide on the occurrence of three coprimary outcomes: the development of diabetes; a core cardiovascular outcome that was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure; and an extended cardiovascular outcome that was a composite of the individual components of the core composite cardiovascular outcome, hospitalization for unstable angina, or arterial revascularization. Results: After adjustment for multiple testing, nateglinide, as compared with placebo, did not significantly reduce the cumulative incidence of diabetes (36% and 34%, respectively; hazard ratio, 1.07; 95% confidence interval [CI], 1.00 to 1.15; P = 0.05), the core composite cardiovascular outcome (7.9% and 8.3%, respectively; hazard ratio, 0.94, 95% CI, 0.82 to 1.09; P = 0.43), or the extended composite cardiovascular outcome (14.2% and 15.2%, respectively; hazard ratio, 0.93, 95% CI, 0.83 to 1.03; P = 0.16). Nateglinide did, however, increase the risk of hypoglycemia. Conclusions: Among persons with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors, assignment to nateglinide for 5 years did not reduce the incidence of diabetes or the coprimary composite cardiovascular outcomes. (ClinicalTrials.gov number, NCT00097786.) Copyright © 2010 Massachusetts Medical Society.

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