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Short Cycles of Both Static and Pulsed Electromagnetic Fields Have No Effect on the Induction of Cytokines by Peripheral Blood Mononuclear Cells
No full textPulsed Electromagnetic Fields Enhance the Induction of Cytokines by Peripheral Blood Mononuclear Cells Challenged with Phytohemagglutinin
No full textCytokine production by human peripheral blood mononuclear cells exposed to low-frequency electromagnetic field
No full textWe evaluated the effects of a 50-Hz pulsed electromagnetic field with a peak magnetic field of 3 mT on the production of cytokines by resting peripheral blood mononuclear cells. Our results demonstrate no modification of interleukin-1β, interleukin-2, or interleukin-6 levels, evaluated 0, 24, and 48 h after exposure, compared with sham-exposed cells. Proliferation indices were also practically unchanged, suggesting the absence of any activating effect of the electromagnetic field. Indeed, concentrations of tumor necrosis factor-α and interferon-γ, evaluated during the same period after 12 h of EMF exposure, were significantly lower than those measured in supernatants of control cells. This was confirmed by evaluation of both cytokines during a 24-h exposure period and 24 h thereafter, in the supernatants of exposed and sham-exposed cells. Comparison between tumor necrosis factor-α biologic activity and the cytokine antigen present in our samples showed strong and reproducible correlation values, suggesting the absence of qualitative differences in this protein due to either proteolytic activity or electromagnetic field
Electromagnetic fields enhance the release of both interferon γ and interleukin-6 by peripheral blood mononuclear cells after phytohaemagglutinin stimulation
No full textWe evaluated the effect of pulsed electromagnetic fields on the eventual activation of peripheral blood mononuclear cells. The cells were exposed to electromagnetic fields with a frequency of 50 Hz and a potency of 3 mT for various times, after which, an exposure time of 12 h was decided on. The results clearly demonstrated that the release of either interferon gamma or interleukin-6 by normal cells exposed to electromagnetic fields for 12 and 24 h was not significantly increased. In contrast, after phytohaemagglutinin challenge, the cells expressed heightened responses to electromagnetic field exposure, with both the proliferative responses and the release of cytokines being significantly increased. In this case, the levels of interferon gamma measured by immunoenzymatic methods 48 h after the treatment were 4827 +/- 4300 pg ml(-1) and were significantly different from the control values (p < 0.05). Evaluation of the biological activity provided results that were practically identical to those of the immunoenzymatic assay, indicating the absence of quantitative and qualitative differences in these proteins. Also, interleukin-6 levels were always higher than in controls and became significant (p < 0.0006) 48 h after the exposure. On the whole, our results indicate that pulsed electromagnetic fields applied continuously for up to 24 h to phytohaemagglutinin-stimulated cells enhance their biological responses. (C) 1998 Elsevier Science S.A
Ozonation of human blood induces a remarkable upregulation of heme oxygenase-1 and heat stress protein-70
No full textHeme oxygenase-I (HO-1) has emerged as one of the most protective enzymes and its pleiotropic activities have been demonstrated in a variety of human pathologies. Unpublished observations have shown that HO-1 is induced after the infusion of ozonated blood into the respective donors, and many other experimental observations have demonstrated the efficacy of oxidizing agents. It appeared worthwhile to evaluate whether we could better define the activity of potential inducers such as hydrogen peroxide and ozonated human plasma. Human vascular endothelial cells at confluence were challenged with different concentrations of these inducers and the simultaneous production of nitric oxide (NO); and HO-1 was measured by either measuring nitrite, or bilirubin formation, or/and the immune reactivity of the protein by Western blot using a rabbit antihuman HO-1 and Hsp-70. The results show that production of both NO and HO-1 is fairly dose dependent but is particularly elevated using human plasma after transient exposure to a medium ozone concentration. At this concentration, there is also induction of Hsp-70. The results clarify another positive effect achievable by the use of ozone therapy
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
Studies on the biological effects of ozone: 7. Generation of reactive oxygen species (ROS) after exposure of human blood to ozone
No full textThe acceptance of any complementary medical approach is conditioned by the results obtained after the same scientific scrutiny applied in orthodox medicine. Otherwise any claim of efficacy remains in the realm of fiction. In the case of ozone therapy, the mechanisms of action have remained nebulous and in a series of publications we are trying to present the biochemical, immunological and morphological evidence in favour or against ozone therapy. We have now shown that ozone (O3) dissolved in the water of either plasma or serum or physiological saline generates reactive oxygen species (ROS), of which hydrogen peroxide (H2O2) can be unequivocally demonstrated by using specific methods for its detection. Lipids present in plasma preferentially those present in lipoproteins, undergo peroxidation that is somewhat O3-dose dependent and can be observed by the measurement of thiobarbituric acid reactive substances (TBARS). While the generation of H2O2 is crucial in activating both biochemical (hexose monophosphate shunt) and immunological (via the transcription factor NF-kB) mechanisms, the role of lipid oxidation products (LOP) remains to be investigated. We have shown here that there is a small but consistent induction of some cytokines (TNF-alpha, IFN-gamma and IL-2) when human blood is directly exposed to O3 concentrations up to 100 micrograms/ml per g of blood. On the other hand, isolated blood mononuclear cells (PBMC) in tissue culture medium are far more sensitive to the oxidant action of O3 as shown by a progressive reduction of the proliferation index with comparatively far lower O3, concentrations. On the whole, these results support the concept that much of the O3 toxicity is neutralized by the powerful antioxidant system of blood. The minimal hemolysis supports this idea but as far as platelets are concerned, we must mention that they tend to aggregate in heparinized blood, even when it is exposed to an O3 concentration of 40 micrograms/ml. In spite of the lack of side-effects after autohemotherapy, this drawback must be kept in mind and avoided in clinical practice
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
Appropriate 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
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