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排序方式: 共有261条查询结果,搜索用时 31 毫秒
131.
Elmar W Tobi Bastiaan T Heijmans Dennis Kremer Hein Putter Henriette A Delemarre-van de Waal Martijn JJ Finken Jan M Wit P Eline Slagboom 《Epigenetics》2011,6(2):171-176
Being born small for gestational age (SGA), a proxy for intrauterine growth restriction (IUGR) and prenatal famine exposure are both associated with a greater risk of metabolic disease. Both associations have been hypothesized to involve epigenetic mechanisms. We investigated whether prenatal growth restriction early in pregnancy was associated with changes in DNA methylation at loci that were previously shown to be sensitive to early gestational famine exposure. We compared 38 individuals born preterm (<32 weeks) and with a birth weight too low for their gestational age (less than −1SDS; SGA) with 75 individuals born preterm but with a birth weight appropriate for their gestational age (greater than −1SDS) and a normal postnatal growth (greater than −1SDS at three months post term; AGA). The SGA individuals were not only lighter at birth, but also had a smaller length (p = 3.3 × 10−13) and head circumference at birth (p = 4.1 × 10−13). The DNA methylation levels of IGF2, GNASAS, INSIGF and LEP were 48.5, 47.5, 79.4 and 25.7% respectively. This was not significantly different between SGA and AGA individuals. Risk factors for being born SGA, including preeclampsia and maternal smoking, were also not associated with DNA methylation at these loci. Growth restriction early in development is not associated with DNA methylation at loci shown to be affected by prenatal famine exposure. Our and previous results by others indicate that prenatal growth restriction and famine exposure may be associated with different epigenetic changes or non-epigenetic mechanisms that may lead to similar later health outcomes.Key words: SGA, DOHAD, IUGR, DNA methylation, famine, IGF2, LEP, INS, GNASAS 相似文献
132.
133.
M Barathan V Mariappan E M Shankar B JJ Abdullah K L Goh J Vadivelu 《Cell death & disease》2013,4(6):e697
Photodynamic therapy (PDT) has emerged as a capable therapeutic modality for the treatment of cancer. PDT is a targeted cancer therapy that reportedly leads to tumor cell apoptosis and/or necrosis by facilitating the secretion of certain pro-inflammatory cytokines and expression of multiple apoptotic mediators in the tumor microenvironment. In addition, PDT also triggers oxidative stress that directs tumor cell killing and activation of inflammatory responses. However, the cellular and molecular mechanisms underlying the role of PDT in facilitating tumor cell apoptosis remain ambiguous. Here, we investigated the ability of PDT in association with hypericin (HY) to induce tumor cell apoptosis by facilitating the induction of reactive oxygen species (ROS) and secretion of Th1/Th2/Th17 cytokines in human hepatocellular liver carcinoma cell line (HepG2) cells. To discover if any apoptotic mediators were implicated in the enhancement of cell death of HY-PDT-treated tumor cells, selected gene profiling in response to HY-PDT treatment was implemented. Experimental results showed that interleukin (IL)-6 was significantly increased in all HY-PDT-treated cells, especially in 1 μg/ml HY-PDT, resulting in cell death. In addition, quantitative real-time PCR analysis revealed that the expression of apoptotic genes, such as BH3-interacting-domain death agonist (BID), cytochrome complex (CYT-C) and caspases (CASP3, 6, 7, 8 and 9) was remarkably higher in HY-PDT-treated HepG2 cells than the untreated HepG2 cells, entailing that tumor destruction of immune-mediated cell death occurs only in PDT-treated tumor cells. Hence, we showed that HY-PDT treatment induces apoptosis in HepG2 cells by facilitating cytotoxic ROS, and potentially recruits IL-6 and apoptosis mediators, providing additional hints for the existence of alternative mechanisms of anti-tumor immunity in hepatocellular carcinoma, which contribute to long-term suppression of tumor growth following PDT. 相似文献
134.
Rob Noorlag Pauline MW van Kempen Cathy B Moelans Rick de Jong Laura ER Blok Ronald Koole Wilko Grolman Paul J van Diest Robert JJ van Es Stefan M Willems 《Epigenetics》2014,9(9):1220-1227
Silencing of tumor suppressor genes (TSGs) by DNA promoter hypermethylation is an early event in carcinogenesis and a potential target for personalized cancer treatment. In head and neck cancer, little is known about the role of promoter hypermethylation in survival. Using methylation specific multiplex ligation-dependent probe amplification (MS-MLPA) we investigated the role of promoter hypermethylation of 24 well-described genes (some of which are classic TSGs), which are frequently methylated in different cancer types, in 166 HPV-negative early oral squamous cell carcinomas (OSCC), and 51 HPV-negative early oropharyngeal squamous cell carcinomas (OPSCC) in relation to clinicopathological features and survival. Early OSCC showed frequent promoter hypermethylation in RARB (31% of cases), CHFR (20%), CDH13 (13%), DAPK1 (12%), and APC (10%). More hypermethylation (≥ 2 genes) independently correlated with improved disease specific survival (hazard ratio 0.17, P = 0.014) in early OSCC and could therefore be used as prognostic biomarker. Early OPSCCs showed more hypermethylation of CDH13 (58%), TP73 (14%), and total hypermethylated genes. Hypermethylation of two or more genes has a significantly different effect on survival in OPSCC compared with OSCC, with a trend toward worse instead of better survival. This could have a biological explanation, which deserves further investigation and could possibly lead to more stratified treatment in the future. 相似文献
135.
In this study, we analyse the distribution and species richness of epibenthic and planktonic Cladocera (Crustacea: Branchiopoda)
in 62 Uganda crater lakes, spread across the climatic gradient between the sub-humid shoulder and semi-arid floor of the East
African Rift Valley. Together, these lakes cover large environmental gradients in salinity, trophic conditions and depth.
In total, 36 species of Cladocera were encountered in the freshwater lakes (<1,500 μS/cm), whereas only a single species was
found in the true saline lakes (>10,000 μS/cm). Cladoceran species richness in individual lakes was found to be determined
primarily by the presence of a well-developed littoral belt of submerged and emergent aquatic macrophytes, pH and salinity.
The highest species richness occurred in fresh but eutrophic shallow waters, with relatively low pH (6.5–7) and dense aquatic
macrophyte growth. As identified by multivariate statistical analysis, the distribution of Cladocera species among the Uganda
lakes was most strongly determined by nutrient availability (measured as total phosphorus), the presence and diversity of
aquatic macrophyte habitat, pH, mean annual temperature and the fraction of the crater catchment that is currently under agriculture.
Since Cladocera play an important role in aquatic food webs, and as such contribute to the ecological integrity of aquatic
ecosystems, an increased understanding of the environmental controls underlying their distribution provides valuable information
on aquatic ecosystem functioning needed for management and conservation. The significant turnover of cladoceran species composition
along the sampled environmental gradients demonstrates their potential as biological indicators for water quality and ecosystem
health in East African lakes. Our results suggest that changes in land use are the greatest threat to natural ecosystem functioning
in these African lakes, and particularly so in the shallower lakes. 相似文献
136.
137.
Sanjiv S. Agarwala Jurgen C. Becker Alexander M. Eggermont Keith T. Flaherty Claus Garbe Alisa M. Goldstein Allan Halpern Mohammed Kashani‐Sabet Axel Hauschild John M. Kirkwood Sancy Leachman Paul Lorigan Martin McMahon Jane Messina Antoni Ribas Wolfram E. Samlowski Dirk Schadendorf Vernon K. Sondak 《Pigment cell & melanoma research》2009,22(5):532-543
This overview of the current state of melanoma research and treatment and directions for moving forward represents the consensus of discussions between expert panelists at the First and Second Global Workshops on Melanoma held in Fajardo, Peurto Rico on November 30–December 1, 2007 and Clearwater Beach, Florida on November 19–20, 2008. 相似文献
138.
The following meeting highlights are from the Perspectives in Melanoma XII conference, held in Scheveningen/The Hague, the Netherlands, on October 2–4, 2008. Selected reviews are included but further discussions of these and other presentations are posted at http://www.MelanomaCare.org . 相似文献
139.
Fekkes D Van Gool AR Bannink M Sleijfer S Kruit WH van der Holt B Eggermont AM Hengeveld MW Stoter G 《Amino acids》2009,37(4):703-708
Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-α (IFN-α).
Animal studies showed that IFN-α administration results in increased levels of biogenic amines, subsequent activation of monoamine
oxidases (MAOs), and finally in a change in NO production due to the H2O2 generated by MAOs. We examined the potential relationship between NO production in plasma and MAO-B activity in platelets
of 43 cancer patients during 8 weeks of treatment with IFN-α. NO synthesis was quantitated by measuring both the ratio of
citrulline and arginine (CIT/ARG-ratio) and total nitrite/nitrate (NOx) levels. Compared to baseline, MAO activity and NOx
increased, while the CIT/ARG-ratio decreased. No associations were found between NOx, MAO and CIT/ARG-ratio. Only few associations
were observed between changes in the biochemical parameters and changes in psychopathology induced by IFN-α, of which the
association between changes in CIT and lassitude was the most consistent. The results suggest that peripheral NO production
and MAO activity are unrelated to each other, and that peripheral changes in these biochemical parameters induced by IFN-α
are unlikely to contribute to definite psychiatric disturbance. 相似文献
140.
Jacques M Mathieu John Schloendorn Bruce E Rittmann Pedro JJ Alvarez 《Microbial cell factories》2009,8(1):21-18
Catabolic insufficiency in humans leads to the gradual accumulation of a number of pathogenic compounds associated with age-related
diseases, including atherosclerosis, Alzheimer's disease, and macular degeneration. Removal of these compounds is a widely
researched therapeutic option, but the use of antibodies and endogenous human enzymes has failed to produce effective treatments,
and may pose risks to cellular homeostasis. Another alternative is "medical bioremediation," the use of microbial enzymes
to augment missing catabolic functions. The microbial genetic diversity in most natural environments provides a resource that
can be mined for enzymes capable of degrading just about any energy-rich organic compound. This review discusses targets for
biodegradation, the identification of candidate microbial enzymes, and enzyme-delivery methods. 相似文献