Search results for "complement"

Stable expression of rat cytochrome P-450IIB1 cDNA in Chinese hamster cells (V79) and metabolic activation of aflatoxin B1.

1988

V79 Chinese hamster fibroblasts are widely used for mutagenicity testing but have the serious limitation that they do not express cytochromes P-450, which are needed for the activation of many promutagens to mutagenic metabolites. A full-length cDNA clone encoding the monooxygenase cytochrome P-450IIB1 under control of the simian virus 40 early promoter was constructed and cointroduced with the selection marker neomycin phosphotransferase (conferring resistance to G418) into V79 Chinese hamster cells. G418-resistant cells were selected, established as cell lines, and tested for cytochrome P-450IIB1 expression and enzymatic activity. Two cell lines (SD1 and SD3) were found that stably produc…

Hormonal regulation of S-adenosylmethionine synthase transcripts in pea ovaries

1996

Two cDNA clones coding for S-adenosyl-L-methionine synthase (SAMs, EC 2.5.1.6) have been isolated from a cDNA library of gibberellic acid-treated unpollinated pea ovaries. Both cDNAs were sequenced showing a high degree of identity but coding for different SAMs polypeptides. The presence of two SAMs genes in pea was further confirmed by Southern analysis. Expression of the SAMs genes in the pea plant was found at different levels in vegetative and reproductive tissues. We characterized the expression levels of SAMs genes during the development or senescence of pea ovaries. Northern analysis showed that transcription of SAMs genes in parthenocarpic fruits was upregulated by auxins in the sam…

Sponge homologue to human and yeast gene encoding the longevity assurance polypeptide: differential expression in telomerase-positive and telomerase-…

2000

Porifera show a characteristic Bauplan in spite of the fact that (almost) all cells are telomerase-positive and presumably provided with an unlimited potency for cell proliferation. Studies revealed that telomerase-positive cells can be triggered to telomerase-negative cells by dissociating them into single cells. Single cells from the demosponge Suberites domuncula, in contrast to cells present in primmorphs (a special form of cell aggregates), lack the property to proliferate and they undergo apoptosis. One gene, SDLAGL, was identified in primmorphs that showed high sequence similarity to the longevity assurance genes from other Metazoa. In single cells no transcripts of SDLAGL could be i…

Injectors with a normal complement in a finite solvable group

2011

Abstract Suppose G is a finite solvable group, and H is a subgroup with a normal complement in G. We shall find necessary and sufficient conditions (some of which are related to the properties of coprime actions) for H to be an injector in G. We shall also use these criteria to find characterizations of injectors which need not have a normal complement.

Algebraic thinking and generalization of patterns: a didactical experience with Italian and Chinese students

2009

Processi cognitivi e soluzioni di problemi matematici con studenti italiani e cinesi

2012

To compare cognitive processes adopted by students with different cultures in solving mathematical problems we have to focus on the Math epistemology through a cultural analysis concerning the fundamental elements of the students different cultural traditions and the philosophical, logic and linguistic bases subtended to the mathematical thought and its historical evolution. The paper describes this theoretical framework, emphasizing a possible comparison between different cognitive styles and mathematical problem solutions in the context of arithmetic and Algebraic thought of Italian and Chinese students in multicultural classes.

Ontogenesis and phylogenesis in the passage from arithmetic to algebraic thought

2012

With this work we retrace some of the fundamental historical and historical epistemological steps of the evolution of algebraic thought. Given the accepted parallelism between ontogenesis and phylogenesis we believe such a research to be a useful approach to the interpretation of obstacles and difficulties that students encounter during the acquisition of algebraic thought.

Mast cells in allergic asthma and beyond.

2010

Mast cells have been regarded for a long time as effector cells in IgE mediated type I reactions and in host defence against parasites. However, they are resident in all environmental exposed tissues and express a wide variety of receptors, suggesting that these cells can also function as sentinels in innate immune responses. Indeed, studies have demonstrated an important role of mast cells during the induction of life-saving antibacterial responses. Furthermore, recent findings have shown that mast cells promote and modulate the development of adaptive immune responses, making them an important hinge of innate and acquired immunity. In addition, mast cells and several mast cell-produced me…

Nutritional Interventions, Complementary and Alternative Medicine for Endometriosis

2022

Since endometriosis symptoms can significantly impact women’s quality of life, while the short-term and particularly long-term therapeutic benefits of the currently available approaches are quite limited, there is increasing frustration among patients who undergo only hormonal and/or surgical intervention. The discovery of changeable risk factors for endometriosis, such as diet and exercise, and the search for complementary and alternative medicine (CAM), has become increasingly attractive. The importance of nutrition in controlling the growth and development of endometriosis has lately emerged as a matter of study, mainly due to the finding that some of the disease-related physiological an…

Dissection of the relative contribution of the Schizosaccharomyces pombe Ctr4 and Ctr5 proteins to the copper transport and cell surface delivery fun…

2011

The Ctr1 family of proteins mediates high-affinity copper (Cu) acquisition in eukaryotic organisms. In the fission yeastSchizosaccharomyces pombe, Cu uptake is carried out by a heteromeric complex formed by the Ctr4 and Ctr5 proteins. Unlike human andSaccharomyces cerevisiaeCtr1 proteins, Ctr4 and Ctr5 are unable to function independently in Cu acquisition. Instead, both proteins physically interact with each other to form a Ctr4–Ctr5 heteromeric complex, and are interdependent for secretion to the plasma membrane and Cu transport activity. In this study, we usedS. cerevisiaemutants that are defective in high-affinity Cu uptake to dissect the relative contribution of Ctr4 and Ctr5 to the Cu…