1,721,121 research outputs found
La genitorialità sociale tra ordine pubblico e interesse del minore
No full textIn un contesto caratterizzato dall'affermarsi della pluralità dei modelli familiari l'interprete è chiamato a ricostruire il concetto di genitorialità in funzione di un interesse del minore a conservare da una parte un rapporto significativo con i genitori biologici, senza pregiudicare, dall'altra, la rilevanza di legame fondati su relazioni affettive alle quali il diritto vivente mostra di riconoscere una crescente rilevanza
A comparative study between spermine oxidase and bovine serum amine oxidase in differential scanning calorimetry and on cytotoxicity on cancer cell lines
No full textSpermine oxidase (SMO) is a FAD-containing enzyme while bovine serum amine-oxidase (BSAO) is a copper amine oxidase and both are able to oxidize polyamines. They play a dominant role in the highly regulated mammalian polyamines catabolism. Spermine oxidase specifically oxidizes spermine (SPM) producing spermidine (SPD), the reactive oxygen species H2O2 and the aldehyde 3-aminopropanal, each with the potential to produce cellular damages and pathologies (1). BSAO deaminates SPM and SPD to H2O2, aldehyde acrolein and ammonia. Since SPM represents a common substrate for SMO and BSAO enzymatic activities, a comparative study was performed on both enzymes in presence of SPM on several tumor cell lines melanoma (M14) and colon adenocarcinoma (LoVo) wild type and their MDR counterparts. SPM is a tetramine that plays mandatory roles in several cell functions, such as DNA synthesis, cellular proliferation, modulation of ion channels function and cellular signaling (1). Our previous studies demonstrated that BSAO and SPM added to human cancer cells induce cytotoxicity and overcome the MDR phenotype (2). We have performed in vitro experiments treating the above human cancer cell lines both phenotype wild type and MDR with SMO in presence of several concentrations of SPM (0-80 μM) for 60 min at 37°C. Cytotoxicity induced by SPM oxidation metabolites, such as H2O2 and the aldehyde 3-aminopropanal, was greater in MDR cells than in the corresponding wild-type ones (WT), maybe due to an increased mitochondrial activity. To get structural information a comparative study was also carried out on both enzymes, by differential Scanning Calorimetry (DSC) (3). The thermal stability of BSAO and SMO is studied by differential scanning calorimetry with a MicroCal MC-2D instrument. Differential scanning calorimetry permits detection of overall changes in protein structure correlated with changes in thermal stability of one or more calorimetric domains. This is particularly important in the case of BSAO and SMO, proteins for which only a little structural information is available. Our previous studies demonstrated that the thermal denaturation profile of the dimeric BSAO is characterized by three distinct endothermic peaks (Tm 58°C, 71.3°C, 77.9°C) (3). The deconvolution of the thermal profile required five two-state transitions, revealed for the dimeric protein a five domain structure, while the monomeric SMO displays one single, endothermic peak (Tm 63°C). The peak may be deconvoluted into two transitions and reveals the presents of two non similar size calorimetric domains: the lowest temperature domain is described by a non two-state transition and the highest temperature domain is described by a two-state transition. The thermal denaturation is irreversible after heating to 100°C.
Since the treatments with BSAO/SPM and SMO/SPM increased the amount of reactive oxygen species (ROS) inside the cells, higher in MDR than WT ones, we hypothesize that the enhancement of amine oxidase activity in tissues, undergoing pathological proliferative phenomena, may reasonably be exploited in the treatment of neoplastic diseases, mainly against MDR tumors.
References:
1- Cervelli M, Amendola R, Polticelli F, Mariottini P (2012). Spermine oxidase ten years later , AminoAcids 42 :441-450
2-Agostinelli, E., Condello, M., Molinari, A., Tempera, G., Viceconte, N., Arancia, G. (2009)
Cytotoxicity of spermine oxidation products to multidrug resistant melanoma M14 ADR2 cells:
Sensitization by the MDL 72527 lysosomotropic compound
International Journal of Oncology 35: 485-498
3) Giartosio A, Agostinelli E and Mondovì B (1988). Domains in bovine serum amine oxidase.
Biochem. Biophys. Res. Comm. 154: 66-72
A novel comprehensive paradigm for the etiopathogenesis of multiple sclerosis: therapeutic approaches and future perspectives on its treatment
No full textIt is well recognized that variation in the geographical distribution of prevalence of multiple sclerosis (MS) exists: increasing the latitude its prevalence increases as well, but the underlying causes of such dissimilarity still remained elusive as of today. Currently, the most accredited hypothesis is that the closer to the equator the more pronounced is the amount of sunlight which, in turn, increases the production of vitamin D. Cholecalciferol is indeed deficient in MS patients, but this factor does not explain by itself the etiopathogenesis of the disease. In the present study, to search for a pattern and provide a model of the disease’s etiology consistent with this regional factor, as well with its changing ethnic, sex-ratio, lifestyle variations and the other unexplained aspects of MS, an extensive analysis of peer-reviewed literature and data was conducted. The arisen hypothesis was that, increasing the latitude, the factor that varies and can have the stronger effect on the human organism, is the continuous and ever-increasing diversity of the natural light–dark cycle. The consequent effort of the suprachiasmatic nucleus to entrain the organism’s circadian rhythm affects the hypothalamic–pituitary–adrenal axis resulting in desynchronizing the central and peripheral circadian clocks and pathologizing the immunitary system. To verify such hypothesis, a theoretical framework of the etiopathogenesis, coherent with the gathered literature, was conceived and a demonstration to corroborate it was eventually devised and performed. The results underscored that people living in countries subjected to a further circadian disruptive factor, as daylight saving time, have a 6.35 times higher prevalence of MS than States placed on their same latitude that do not observe it, thus strongly supporting the hypothesis. As further reinforcement of the conclusions, it is worth mentioning that the levels of polyamines rise abruptly in autoimmune diseases. Moreover, among their numerous roles, these polycations participate to the regulation of the circadian clock so their sudden variation might disrupt it. Following these interesting findings, new perspectives in therapies are, therefore, proposed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Spin-glass-like freezing and enhanced magnetization in ultra-small CoFe2O4 nanoparticles
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Have mammalian amine oxidases and mitochondrial polyamine transporter a similar protein structure?
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