157 research outputs found

    Transcriptional Studies of the Muscle-Specific Expression of the Rabbit Muscle Phosphofructokinase Gene.

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    The rabbit muscle phosphofructokinase (RM-PFK) gene is predominantly expressed in skeletal muscle. Its muscle-specific transcription was investigated using transient transfection studies, electrophoretic mobility shift assays, and DNaseI footprinting experiments. The evidence presented here provides the first example of the myogenic basic-Helix-Loop-Helix proteins regulating a gene that encodes a glycolytic enzyme. The 3 kb 5\sp\prime-flanking sequence of this gene directed the expression of the chloramphenicol acetyltransferase gene in muscle and non-muscle cells. MyoD, Myf5, and myogenin exhibited differential transactivation capabilities. MyoD had the most pronounced transactivational effect, and its N-terminal transactivation domain and the basic DNA-binding region were required for its function. The RM-PFK gene has at least two muscle-specific promoters that are approximately 1.9 kb apart, and that were stimulated by the myogenic regulators to different extents. The proximal promoter was the major promoter responding to transactivation of the myogenic regulators. Progressive deletional analysis revealed that there were two positive and two negative regulatory regions controlling the proximal promoter. An enhancer region, E1, contains a CAGCTG E-box that was recognized by MyoD glutathione S-transferase fusion in vitro. Along with this E-box, two other specific sequences were also recognized by the nuclear proteins of C2C12 cells. The TATA-less proximal promoter was localized to a 268 bp region, with its core promoter lying within region -95 to +23 with respect to the cap site. A pyrimidine-rich initiator and a myotube-specific AG-rich sequence within the core promoter were recognized by the nuclear proteins of C2C12 cells. MyoD stimulation was mediated through the sequences around the core promoter, mainly through the region (-195 to -95) containing a crucial CAGATG E-box. A CAGCTG E-box and a CCATCGT sequence downstream of the core promoter were also recognized by the nuclear proteins of C2C12 cells. In contrast, the distal promoter b was localized within a 671 bp region and might contain a TATA element (TTATTTATT). Thus, the differences in regulation of these promoters may be correlated with their divergent DNA compositions

    Transdisciplinary, co-designed and adaptive management for the sustainable development of rongcheng, a coastal city in China in the context of human activities and climate change

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    Half the population of China live in coastal zones where 70% of large cities are also located. Intensive human activities pose significant environmental and ecological hazards to these cities that are already vulnerable to natural hazards and climate change. The sustainable development of coastal cities is thus both a national and international issue. Rongcheng is a typical coastal city in east China. It is a national marine ranch demonstration area that is subjected to multi-stressors from human activities and climate change. The dominant economic sectors include aquaculture and fisheries, agriculture, shipping and tourism. A multitude of resulting pressures come mainly from intensified human activities, such as intensive aquaculture, overfishing, industrial pollutants, agricultural runoff, land reclamation and port expansion. In addition, Rongcheng is also facing exogenic pressures from extreme climate events such as intensified storms, storm surges, droughts and sea ice. A growing awareness of these problems brought together a trans-disciplinary group from local government, research institutions, local practitioners and coastal representatives to jointly explore and co-design adaptive coastal management options. In this transdisciplinary study, a social-ecological analysis based on a combination of the Systems Approach Framework and the Drivers-Pressures-States-Impacts-Responses framework was used to analyze and formulate an adaptive management plan for the sustainability of Rongcheng. More than 40 stakeholders including government, companies, civil society and institutions participated in the study through questionnaires and on-site meetings. A statistical analysis of the results identified urgent issues impeding the sustainable development of Rongcheng. The issues identified were poorly regulated aquaculture, loss of shoreline, and the decline of seagrass and cultural heritage.The study identified management options and measures, some of which were adopted by the local government in a co-designed management plan. The measures included upgrading of aquaculture industry, habitat conservation and restoration, and the development of cultural tourism. Another outcome was the increased knowledge exchange between stakeholders to inform management, policy, and decision making, as well as raised awareness of vulnerability to natural hazards and climate change. The success of this case study provides a reference for the adaptive management of other coastal cities and their sustainable development in a changing climate.info:eu-repo/semantics/publishedVersio

    Analysis of sugar content in formula foods and complementary foods for infants and young children aged 0-36 months in China

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    ObjectiveTo investigate the implementation of the standards (formula foods and complementary foods for infants and young children), the contents of glucose, galactose, fructose, lactose, sucrose and maltose in formula foods and complementary foods for infants aged 0-36 months, and provide data support for the management of food safety standards related to infant formula and infant complementary food in China.MethodsBased on the principle of random sampling, 83 formula food and complementary food for infants and young children, including infant formula foods, older infant formula foods, young children formula foods, cereal complementary foods and canned foods for infants and young children, were collected from the domestic market, the content of glucose, galactose, fructose, lactose, sucrose and maltose were determined by ion chromatography-pulse ampere method and the results were analyzed.ResultsThe median of total sugar content in formula foods for infants and young children was 433.43-476.99 g/kg; the proportion of lactose in all kinds of products was higher than 95%, and the content from high to low was infant formula, older infant formula and formula for young children. The detection rate of sugar in infant cereal supplementary food was 36.8%, the median content was 0-28.35 g/kg; the medians of lactose and sucrose were 84.30 and 70.17 g/kg; while the third quartile(Q3) of sucrose was 53.43 g/kg. There was no significant difference in the content of added sugar between domestic and imported formula foods(P>0.05).ConclusionThe lactose content in formula foods for infants and young children sold in China is higher than that of other sugars. The content of total sugar in cereal supplementary food is low, but the content of sucrose in biscuit should be concerned. It is suggested that enterprises should strictly control added sugar, and government departments should continue to push the implementation of the sugar content regulation in the newly released national standards

    DNA Methylation Supports Intrinsic Epigenetic Memory in Mammalian Cells

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    We have investigated the role of DNA methylation in the initiation and maintenance of silenced chromatin in somatic mammalian cells. We found that a mutated transgene, in which all the CpG dinucleotides have been eliminated, underwent transcriptional silencing to the same extent as the unmodified transgene. These observations demonstrate that DNA methylation is not required for silencing. The silenced CpG-free transgene exhibited all the features of heterochromatin, including silencing of transcriptional activity, delayed DNA replication, lack of histone H3 and H4 acetylation, lack of H3-K4 methylation, and enrichment in tri-methyl-H3-K9. In contrast, when we tested for transgene reactivation using a Cre recombinase-mediated inversion assay, we observed a marked difference between a CpG-free and an unmodified transgene: the CpG-free transgene resumed transcription and did not exhibit markers of heterochromatin whereas the unmodified transgene remained silenced. These data indicate that methylation of CpG residues conferred epigenetic memory in this system. These results also suggest that replication delay, lack of histone H3 and H4 acetylation, H3-K4 methylation, and enrichment in tri-methyl-H3-K9 are not sufficient to confer epigenetic memory. We propose that DNA methylation within transgenes serves as an intrinsic epigenetic memory to permanently silence transgenes and prevent their reactivation

    The Prognostic Value of Preoperative Serum Tumor Markers in Non-Small Cell Lung Cancer Varies With Radiological Features and Histological Types

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    ObjectivesTo assess the association between common-used serum tumor markers and recurrence of lung adenocarcinoma and squamous cell carcinoma separately and determine the prognostic value of serum tumor markers in lung adenocarcinoma featured as ground glass opacities.MethodsA total of 2,654 non-small cell lung cancer patients undergoing surgical resection between January 2008 and September 2014 were analyzed. The serum levels of carcinoma embryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), neuron-specific enolase (NSE), carbohydrate antigen 125 (CA125), carbohydrate antigen 153 (CA153) and carbohydrate antigen 199 (CA199) were tested preoperatively. Survival analyses were performed with COX proportional hazard regression.ResultsAmong patients with lung adenocarcinoma, elevated preoperative serum CEA(HR=1.246, 95%CI:1.043-1.488, P=0.015), CYFRA21-1(HR=1.209, 95%CI:1.015-1.441, P=0.034) and CA125(HR=1.361, 95%CI:1.053-1.757, P=0.018) were significantly associated with poorer recurrence free survival (RFS). Elevated preoperative serum CA199 predicted worse RFS in patients diagnosed with lung squamous cell carcinoma (HR=1.833, 95%CI: 1.216-2.762, P=0.004). Preoperative serum CYFRA21-1(HR=1.256, 95%CI:1.044-1.512, P=0.016) and CA125(HR=1.373, 95%CI: 1.050-1.795, P=0.020) were independent prognostic factors for patients with adenocarcinoma presenting as solid nodules while serum CEA (HR=2.160,95%CI:1.311-3.558, P=0.003) and CA125(HR=2.475,95%CI:1.163-5.266, P=0.019) were independent prognostic factors for patients with adenocarcinoma featured as ground glass opacities.ConclusionsThe prognostic significances of preoperative serum tumor markers in non-small cell lung cancer were associated with radiological features and histological types

    FAM-MDR: A Flexible Family-Based Multifactor Dimensionality Reduction Technique to Detect Epistasis Using Related Individuals

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    We propose a novel multifactor dimensionality reduction method for epistasis detection in small or extended pedigrees, FAM-MDR. It combines features of the Genome-wide Rapid Association using Mixed Model And Regression approach (GRAMMAR) with Model-Based MDR (MB-MDR). We focus on continuous traits, although the method is general and can be used for outcomes of any type, including binary and censored traits. When comparing FAM-MDR with Pedigree-based Generalized MDR (PGMDR), which is a generalization of Multifactor Dimensionality Reduction (MDR) to continuous traits and related individuals, FAM-MDR was found to outperform PGMDR in terms of power, in most of the considered simulated scenarios. Additional simulations revealed that PGMDR does not appropriately deal with multiple testing and consequently gives rise to overly optimistic results. FAM-MDR adequately deals with multiple testing in epistasis screens and is in contrast rather conservative, by construction. Furthermore, simulations show that correcting for lower order (main) effects is of utmost importance when claiming epistasis. As Type 2 Diabetes Mellitus (T2DM) is a complex phenotype likely influenced by gene-gene interactions, we applied FAM-MDR to examine data on glucose area-under-the-curve (GAUC), an endophenotype of T2DM for which multiple independent genetic associations have been observed, in the Amish Family Diabetes Study (AFDS). This application reveals that FAM-MDR makes more efficient use of the available data than PGMDR and can deal with multi-generational pedigrees more easily. In conclusion, we have validated FAM-MDR and compared it to PGMDR, the current state-of-the-art MDR method for family data, using both simulations and a practical dataset. FAM-MDR is found to outperform PGMDR in that it handles the multiple testing issue more correctly, has increased power, and efficiently uses all available information

    DNA Double-Strand Break Repair Genes and Oxidative Damage in Brain Metastasis of Breast Cancer

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    Background Breast cancer frequently metastasizes to the brain, colonizing a neuro-inflammatory microenvironment. The molecular pathways facilitating this colonization remain poorly understood. Methods Expression profiling of 23 matched sets of human resected brain metastases and primary breast tumors by two-sided paired t test was performed to identify brain metastasis–specific genes. The implicated DNA repair genes BARD1 and RAD51 were modulated in human (MDA-MB-231-BR) and murine (4T1-BR) brain-tropic breast cancer cell lines by lentiviral transduction of cDNA or short hairpin RNA (shRNA) coding sequences. Their functional contribution to brain metastasis development was evaluated in mouse xenograft models (n = 10 mice per group). Results Human brain metastases overexpressed BARD1 and RAD51 compared with either matched primary tumors (1.74-fold, P < .001; 1.46-fold, P < .001, respectively) or unlinked systemic metastases (1.49-fold, P = .01; 1.44-fold, P = .008, respectively). Overexpression of either gene in MDA-MB-231-BR cells increased brain metastases by threefold to fourfold after intracardiac injections, but not lung metastases upon tail-vein injections. In 4T1-BR cells, shRNA-mediated RAD51 knockdown reduced brain metastases by 2.5-fold without affecting lung metastasis development. In vitro, BARD1- and RAD51-overexpressing cells showed reduced genomic instability but only exhibited growth and colonization phenotypes upon DNA damage induction. Reactive oxygen species were present in tumor cells and elevated in the metastatic neuro-inflammatory microenvironment and could provide an endogenous source of genotoxic stress. Tempol, a brain-permeable oxygen radical scavenger suppressed brain metastasis promotion induced by BARD1 and RAD51 overexpression. Conclusions BARD1 and RAD51 are frequently overexpressed in brain metastases from breast cancer and may constitute a mechanism to overcome reactive oxygen species–mediated genotoxic stress in the metastatic brain

    Effects of oat (Avena sativa L.) hay diet supplementation on the intestinal microbiome and metabolome of Small-tail Han sheep

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    Supplementation of the sheep diet with oats (Avena sativa L.) improves animal growth and meat quality, however effects on intestinal microbes and their metabolites was not clear. This study aimed to establish the effect of dietary oat supplementation on rumen and colonic microbial abundance and explore the relationship with subsequent changes in digesta metabolites. Twenty Small-tail Han sheep were randomly assigned to a diet containing 30 g/100 g of maize straw (Control) or oat hay (Oat). After 90-days on experimental diets, rumen and colon digesta were collected and microbial diversity was determined by 16S rRNA gene Illumina NovaSeq sequencing and metabolomics was conducted using Ultra-high performance liquid chromatography Q-Exactive mass spectrometry (UHPLC-QE-MS). Compared to Control group, oat hay increased the abundance of Bacteroidetes and Fibrobacteres as well as known short-chain fatty acid (SCFA) producers Prevotellaceae, Ruminococcaceae and Fibrobacteraceae in rumen (p &lt; 0.05). In rumen digesta, the Oat group showed had higher levels of (3Z,6Z)-3,6-nonadienal, Limonene-1,2-epoxide, P-tolualdehyde, and Salicylaldehyde compared to Control (p &lt; 0.05) and these metabolites were positively correlated with the abundance of cecal Prevotellaceae NK3B31. In conclusion, supplementation of the sheep diet with oat hay improved desirable microbes and metabolites in the rumen, providing insight into mechanisms whereby meat quality can be improved by oat hay supplementation
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