1,720,992 research outputs found

    Il dolore e la medicina. Alla ricerca di senso e di cure

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    Raccolta di saggi sul problema del dolore e del suo significato per la medicina visto da diverse prospettive: medica, filosofica e religiosa. Si insiste in particolare sulla necessità di una medicina che sappia considerare tutta la persona umana, anche nello stesso processo di diagnosi e cura delle malatie, tenendo nella dovuta considerazione l'influenza dei fattori psicologici e spirituali sulla genesi e il decorso delle malattie e sulla loro guarigione

    Respiratory response of phagocytes: terminal NADPH oxidase and the mechanisms of its activation

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    The chemical composition, properties and activation mechanism of the O2(-)-forming NADPH oxidase of phagocytes were investigated, using partially purified enzyme preparations. Highly active NADPH oxidase was extracted as an aggregate of high Mr from the membranes of neutrophils and macrophages. The enzyme complex contained phospholipids and cytochrome b-245, very little FAD and almost no quinones or NAD(P)H-dye reductase activity. The purification of a polypeptide with a relative molecular mass of 31 500 strictly paralleled the purification of NADPH oxidase, suggesting that this polypeptide is a component of the enzyme. This protein was identified as cytochrome b -245 after dissociation of the proteolipid complex and purification of the cytochrome moiety. The 31 500 Mr protein was phosphorylated in enzyme preparations from activated but not from resting cells. The results indicate that: cytochrome b-245 is a major component of NADPH oxidase; the involvement of NAD(P)H dye reductases in the O2(-)-forming activity is questionable; the cytochrome b-245: FAD ratio in the enzyme complex is much higher than that indicated in crude preparations; the Mr of pig neutrophil cytochrome b-245 is 31 500; the activation of the O-2-forming system involves a process of phosphorylation of cytochrome b-245

    Homeopathy and placebo RID C-3728-2011

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    The foundation of homeopathic medicine is the 'Similia Principle', also known as the 'Principle of Similarity' or also as the 'Simile', which reflects the inversion of pharmacological effects in healthy subjects as compared with sick ones. This article describes the inversion of effects, a widespread medical phenomenon, through three possible mechanisms: non-linearity of dose-response relationship, different initial pathophysiological states of the organism, and pharmacodynamics of body response to the medicine. Based on the systemic networks which play an important role in response to stress, a unitary and general model is designed: homeopathic medicines could interact with sensitive (primed) regulation systems through complex information, which simulate the disorders of natural disease. Reorganization of regulation systems, through a coherent response to the medicine, could pave the way to the healing of the cellular, tissue and neuro-immuno-endocrine homeodynamics. Preliminary evidence is suggesting that even ultra-low doses and high-dilutions of drugs may incorporate structural or frequency information and interact with chaotic dynamics and physical-electromagnetic levels of regulation. From the clinical standpoint, the 'simile' can be regarded as a heuristic principle, according to which the detailed knowledge of pathogenic effects of drugs, associated with careful analysis of signs and symptoms of the ill subject, could assist in identifying homeopathic remedies with high grade of specificity for the individual case

    Mechanism of production of toxic oxygen radicals by granulocytes and macrophages and their function in the inflammatory process

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    The paper deals with 1) the features of the respiratory burst (increase of the respiration with production of O2 metabolites, O2-, H2O2, OH) of the inflammatory cells; 2) the factors responsible for its activation; 3) the methods for its measurement; 4) the molecular events which take place at the level of the plasma membrane following the interaction between the stimuli and the cell surface (the Ca++ changes, the modification of membrane potential, the activation of phospholipid turnover) and the hypothesis of the activation of the protein kinase C; 5) the nature of the NADPH oxidase whose activation is responsible for the respiratory burst and the production of O2 metabolites; 6) the defensive, toxic, proinflammatory and modulatory effects due to the reactivity of the oxygen metabolites

    Partial purification of the superoxide-generating system of macrophages. Possibleassociation of the NADPH oxidase activity with a low-potential (-247 mV)cytochrome b

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    NADPH oxidase activity was solubilized by detergent treatment of subcellular particles obtained from guinea-pig peritoneal macrophages stimulated with phorbol myristate acetate. Gel filtration of the material containing the NADPH oxidase activity gave two peaks of proteins, one of which eluted with the void and the other with the included volume of an AcA 22 column. The material eluted in the void volume contained more than 50% of the NADPH oxidase activity and less than 10% of the NAD(P)H cytochrome c reductase activity. A b-type cytochrome with peaks of absorption at 558, 528 and 426 nm was also enriched in the fraction which contained the NADPH oxidase activity. The distribution of flavoproteins as revealed by the measurement of FAD was different from that of NADPH oxidase and cytochrome b, and followed the elution profile of NADH cytochrome c reductase. Studies in subcellular particles showed that the b cytochromes of mitochondria and endoplasmic reticulum reduced by selective biochemical means accounted for only a minor part of the total b-type cytochromes and that the new cytochrome b previously described in neutrophils is the major chromophore also in macrophages. Oxidation-reduction midpoint potential of the partially purified cytochrome b was shown to be -247 mV. Association of cytochrome b with the NADPH oxidase activity and its very low Em7.0 makes it a suitable candidate to be part of the superoxide-generating system also in macrophages

    Medicina ufficiale e terapie non convenzionali: dal conflitto all'integrazione?

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    Tentativo di valutazione delle medicine alternative dal punto di vista scientifico e metodologico, in base alle acquisizioni della scienza della complessità, in collaborazione con un gruppo di medici impegnati da anni in questo lavoro

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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