91 research outputs found

    Expression analysis of banana MaECHI1 during fruit ripening with different treatments

    Get PDF
    The main function of endochitinase is believed to be pathogenesis related protein. However, more and more scientists reported the roles of endochitinase in plant growth and development. In order to investigate the role of endochitinase in postharvest banana fruit ripening, an endochitinase gene known as MaECHI1 had been isolated from a suppression subtractive hybridization (SSH) complementary deoxyribonucleic acid (cDNA) library. MaECHI1 was mainly expressed in banana fruit and flowers. Ethylene biosynthesis, gene expression and chitinase activities in different stages of postharvest banana fruit with or without ethylene and 1-methylcycle–propene (1-MCP) treatments were investigated. The results show that under ethylene treatment, banana ethylene production, gene expression, and chitinase activities increased markedly at the onset of banana ripening. Moreover, banana ethylene production and MaECHI1 gene expression peaks appeared earlier with ethylene treatment than with other treatment. MaECHI1 gene expression was markedly responsive to the fruit ripening process and to exogenous ethylene treatment.Keywords: Banana (Musa acuminata L.AAA), endochitinase gene expression, ethylene production fruit ripenin

    Integrated application of uniform design and least-squares support vector machines to transfection optimization

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Transfection in mammalian cells based on liposome presents great challenge for biological professionals. To protect themselves from exogenous insults, mammalian cells tend to manifest poor transfection efficiency. In order to gain high efficiency, we have to optimize several conditions of transfection, such as amount of liposome, amount of plasmid, and cell density at transfection. However, this process may be time-consuming and energy-consuming. Fortunately, several mathematical methods, developed in the past decades, may facilitate the resolution of this issue. This study investigates the possibility of optimizing transfection efficiency by using a method referred to as least-squares support vector machine, which requires only a few experiments and maintains fairly high accuracy.</p> <p>Results</p> <p>A protocol consists of 15 experiments was performed according to the principle of uniform design. In this protocol, amount of liposome, amount of plasmid, and the number of seeded cells 24 h before transfection were set as independent variables and transfection efficiency was set as dependent variable. A model was deduced from independent variables and their respective dependent variable. Another protocol made up by 10 experiments was performed to test the accuracy of the model. The model manifested a high accuracy. Compared to traditional method, the integrated application of uniform design and least-squares support vector machine greatly reduced the number of required experiments. What's more, higher transfection efficiency was achieved.</p> <p>Conclusion</p> <p>The integrated application of uniform design and least-squares support vector machine is a simple technique for obtaining high transfection efficiency. Using this novel method, the number of required experiments would be greatly cut down while higher efficiency would be gained. Least-squares support vector machine may be applicable to many other problems that need to be optimized.</p

    Propofol Inhibits Lipopolysaccharide-Induced Tumor Necrosis Factor-Alpha Expression and Myocardial Depression through Decreasing the Generation of Superoxide Anion in Cardiomyocytes

    Get PDF
    TNF-α has been shown to be a major factor responsible for myocardial depression in sepsis. The aim of this study was to investigate the effect of an anesthetic, propofol, on TNF-α expression in cardiomyocytes treated with LPS both in vivo and in vitro. In cultured cardiomyocytes, compared with control group, propofol significantly reduced protein expression of gp91phox and phosphorylation of extracellular regulated protein kinases 1/2 (ERK1/2) and p38 MAPK, which associates with reduced TNF-α production. In in vivo mice studies, propofol significantly improved myocardial depression and increased survival rate of mice after LPS treatment or during endotoxemia, which associates with reduced myocardial TNF-α production, gp91phox, ERK1/2, and p38 MAPK. It is concluded that propofol abrogates LPS-induced TNF-α production and alleviates cardiac depression through gp91phox/ERK1/2 or p38 MAPK signal pathway. These findings have great clinical importance in the application of propofol for patients enduring sepsis

    Diurnal Variations of Particle-bound PAHs at a Traffic Site in Xiamen, China

    Get PDF
    To improve our current understanding of the fate of particle-bound PAHs, which include potent mutagens and carcinogens, diurnal measurements of these compounds were carried out from 23 Oct to 31 Dec 2008 at a busy traffic site in Xiamen, China. The sum of 19 PAH concentrations showed a just noticeable day-night difference in the warmer period (from 23 Oct to 25 Nov) to a remarkable day-night difference in the colder period (from 26 Nov to 31 Dec). However, the average profiles of the 19 PAHs in the warmer and colder periods were very similar for both day and night samples. Atmospheric mixing seemed to have more influence on the diurnal variations in PAHs than photodecomposition resulting from solar radiation, because PAH concentrations showed negative correlation with air temperature but significantly positive correlation with the ratios of reactive to stable PAHs, such as benz[a] anthracene to chrysene and benzo[a] pyrene to benzo[e] pyrene. Based on the diagnostic ratios of indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd] pyrene plus benzo[g, h, i]perylene and fluoranthene to fluoranthene plus pyrene, the results showed that no significant differences were observed in PAHs sources between the warm and cold periods and a combination of grass, wood or coal combustion and petroleum sources in airborne particles might be the most significant contributors of PAHs. Gas-phase PAHs were calculated based on the theoretical gas/particle partitioning coefficients for 19 PAHs and a high fraction of daily exposure was attributed to particle-phase PAHs in most cases. The excess lifetime cancer risk in colder period was generally higher than in the warmer period. The total uncertainties were computed based on the simpler average error transfer formula.Natural Science Foundation (NSFC) [40971257, 20777060

    Self Assessment in Insects: Honeybee Queens Know Their Own Strength

    Get PDF
    Contests mediate access to reproductive opportunities in almost all species of animals. An important aspect of the evolution of contests is the reduction of the costs incurred during intra-specific encounters to a minimum. However, escalated fights are commonly lethal in some species like the honeybee, Apis mellifera. By experimentally reducing honeybee queens' fighting abilities, we demonstrate that they refrain from engaging in lethal contests that typically characterize their reproductive dominance behavior and coexist peacefully within a colony. This suggests that weak queens exploit an alternative reproductive strategy and provides an explanation for rare occurrences of queen cohabitation in nature. Our results further indicate that self-assessment, but not mutual assessment of fighting ability occurs prior to and during the agonistic encounters

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

    Get PDF
    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

    Get PDF

    Rediscovery and amended descriptions of Begonia kingdon-wardii (Begoniaceae) from North Myanmar

    No full text
    Begonia kingdon-wardii Tebbitt was rediscovered in 2014 from Myanmar after 67 years based on its last collection in 1937. Its previously unknown female flower and inaccurate morphology of leaf and ovary have been additionally described. This species belongs to Begonia sect. Sphenanthera (Hassk.) Warb. due to its dioecious habit, 3-locular ovary, berry fruits and thick placenta segments. Morphologically, it is similar to Begonia gulinqingensis S. H. Huang & Y. M. Shui in the leaf shape, placentation and fruit shape, but different in its dioecious plants, pliciform leaves, two-petalled female flowers and berry fruits. The rediscovery of this amazing living species will attract significant interest for scientific research and horticultural application

    Balance of Yin and Yang: Ubiquitylation-Mediated Regulation of p53 and c-Myc,

    Get PDF
    Protein ubiquitylation has been demonstrated to play a vital role not only in mediating protein turnover but also in modulating protein activity. The stability and activity of the tumor suppressor p53 and of the oncoprotein c-Myc are no exception. Both are regulated through independent ubiquitylation by several E3 ubiquitin ligases. Interestingly, p53 and c-Myc are functionally connected by some of these E3 enzymes and their regulator ARF, although these proteins play opposite roles in controlling cell growth and proliferation. The balance of this complex ubiquitylation network and its disruption during oncogenesis will be the topics of this review
    corecore