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891.
Hayes EK Lechowicz A Petrik JJ Storozhuk Y Paez-Parent S Dai Q Samjoo IA Mansell M Gruslin A Holloway AC Raha S 《PloS one》2012,7(3):e33370
Maternal obesity results in a number of obstetrical and fetal complications with both immediate and long-term consequences. The increased prevalence of obesity has resulted in increasing numbers of women of reproductive age in this high-risk group. Since many of these obese women have been subjected to hypercaloric diets from early childhood we have developed a rodent model of life-long maternal obesity to more clearly understand the mechanisms that contribute to adverse pregnancy outcomes in obese women. Female Sprague Dawley rats were fed a control diet (CON--16% of calories from fat) or high fat diet (HF--45% of calories from fat) from 3 to 19 weeks of age. Prior to pregnancy HF-fed dams exhibited significant increases in body fat, serum leptin and triglycerides. A subset of dams was sacrificed at gestational day 15 to evaluate fetal and placental development. The remaining animals were allowed to deliver normally. HF-fed dams exhibited a more than 3-fold increase in fetal death and decreased neonatal survival. These outcomes were associated with altered vascular development in the placenta, as well as increased hypoxia in the labyrinth. We propose that the altered placental vasculature may result in reduced oxygenation of the fetal tissues contributing to premature demise and poor neonatal survival. 相似文献
892.
Efficacy of short-term high-dose statin in preventing contrast-induced nephropathy: a meta-analysis of seven randomized controlled trials 总被引:1,自引:0,他引:1
Background
A few studies focused on statin therapy as specific prophylactic measures of contrast-induced nephropathy have been published with conflicting results. In this meta-analysis of randomized controlled trials, we aimed to assess the effectiveness of shor-term high-dose statin treatment for the prevention of CIN and clinical outcomes and re-evaluate of the potential benefits of statin therapy.Methods
We searched PubMed, OVID, EMBASE, Web of science and the Cochrane Central Register of Controlled Trials databases for randomized controlled trials comparing short-term high-dose statin treatment versus low-dose statin treatment or placebo for preventing CIN. Our outcome measures were the risk of CIN within 2–5 days after contrast administration and need for dialysis.Results
Seven randomized controlled trials with a total of 1,399 patients were identified and analyzed. The overall results based on fixed-effect model showed that the use of short-term high-dose statin treatment was associated with a significant reduction in risk of CIN (RR = 0.51, 95% CI 0.34–0.76, p = 0.001; I2 = 0%). The incidence of acute renal failure requiring dialysis was not significant different after the use of statin (RR = 0.33, 95% CI 0.05–2.10, p = 0.24; I2 = 0%). The use of statin was not associated with a significant decrease in the plasma C-reactive protein level (SMD −0.64, 95% CI: −1.57 to 0.29, P = 0.18, I2 = 97%).Conclusions
Although this meta-analysis supports the use of statin to reduce the incidence of CIN, it must be considered in the context of variable patient demographics. Only a limited recommendation can be made in favour of the use of statin based on current data. Considering the limitations of included studies, a large, well designed trial that incorporates the evaluation of clinically relevant outcomes in participants with different underlying risks of CIN is required to more adequately assess the role for statin in CIN prevention. 相似文献893.
Yi-Xing Li Wen-Li Mei Wen-Jian Zuo You-Xing Zhao Wen-Hua Dong Hao-Fu Dai 《Phytochemistry letters》2012,5(1):41-44
Phytochemical investigation on the stems of Trigonostemon heterophyllus led to the isolation of a new diterpene, trigonoheterene (1), and a new naphthoquinone, trigonoheterone (2), together with two known compounds, 3,4-seco-sonderianol, (3) and trigonochinene E, (4). Their structures were determined by spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). All compounds were evaluated for cytotoxic activities and antibacterial activities. 相似文献
894.
Li QL Gu FM Wang Z Jiang JH Yao LQ Tan CJ Huang XY Ke AW Dai Z Fan J Zhou J 《PloS one》2012,7(3):e33379
Background
Rapamycin is an attractive approach for the treatment and prevention of HCC recurrence after liver transplantation. However, the objective response rates of rapamycin achieved with single-agent therapy were modest, supporting that rapamycin resistance is a frequently observed characteristic of many cancers. Some studies have been devoted to understanding the mechanisms of rapamycin resistance, however, the mechanisms are cell-type-dependent and studies on rapamycin resistance in HCC are extremely limited.Methodology/Principal Findings
The anti-tumor sensitivity of rapamycin was modest in vitro and in vivo. In both human and rat HCC cells, rapamycin up-regulated the expression and phosphorylation of PDGFRβ in a time and dose-dependent manner as assessed by RT-PCR and western blot analysis. Using siRNA mediated knockdown of PDGFRβ, we confirmed that subsequent activation of AKT and ERK was PDGFRβ-dependent and compromised the anti-tumor activity of rapamycin. Then, blockade of this PDGFRβ-dependent feedback loop by sorafenib enhanced the anti-tumor sensitivity of rapamycin in vitro and in an immunocompetent orthotopic rat model of HCC.Conclusions
Activation of PI3K/AKT and MAPK pathway through a PDGFRβ-dependent feedback loop compromises the anti-tumor activity of rapamycin in HCC, and blockade of this feedback loop by sorafenib is an attractive approach to improve the anti-tumor effect of rapamycin, particularly in preventing or treating HCC recurrence after liver transplantation. 相似文献895.
We have studied the fluorescence of Mg-Al-Eu ternary layered hydroxides (TLH) quenched by tryptophan (Trp). IR spectroscopy was used to evaluate the change of Trp structure which was caused by TLH. XRD and TG-DTA results further suggested a structural change of Trp after being reacted with TLH. XPS characterization confirmed a strong chemical reaction between Trp and TLH. These studies may present more direct evidence to explain the interrelation between the structural change of Trp and the fluorescent quenching of TLH. 相似文献
896.
Wang L Aryal UK Dai Z Mason AC Monroe ME Tian ZX Zhou JY Su D Weitz KK Liu T Camp DG Smith RD Baker SE Qian WJ 《Journal of proteome research》2012,11(1):143-156
Protein glycosylation (e.g., N-linked glycosylation) is known to play an essential role in both cellular functions and secretory pathways; however, our knowledge of in vivo N-glycosylated sites is very limited for the majority of fungal organisms including Aspergillus niger. Herein, we present the first extensive mapping of N-glycosylated sites in A. niger by applying an optimized solid phase glycopeptide enrichment protocol using hydrazide-modified magnetic beads. The enrichment protocol was initially optimized using both mouse blood plasma and A. niger secretome samples, and it was demonstrated that the protein-level enrichment protocol offered superior performance over the peptide-level protocol. The optimized protocol was then applied to profile N-glycosylated sites from both the secretome and whole cell lysates of A. niger. A total of 847 N-glycosylated sites from 330 N-glycoproteins (156 proteins from the secretome and 279 proteins from whole cells) were confidently identified by LC-MS/MS. The identified N-glycoproteins in the whole cell lysate were primarily localized in the plasma membrane, endoplasmic reticulum, Golgi apparatus, lysosome, and storage vacuoles, supporting the important role of N-glycosylation in the secretory pathways. In addition, these glycoproteins are involved in many biological processes including gene regulation, signal transduction, protein folding and assembly, protein modification, and carbohydrate metabolism. The extensive coverage of N-glycosylated sites and the observation of partial glycan occupancy on specific sites in a number of enzymes provide important initial information for functional studies of N-linked glycosylation and their biotechnological applications in A. niger. 相似文献
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Passerini L Casey GJ Biggs BA Cong DT Phu LB Phuc TQ Carone M Montresor A 《PLoS neglected tropical diseases》2012,6(4):e1608