181 research outputs found
Evaluation of Anti-Inflammatory Activity of Pseudananas macrodontes (Morr.) Harms (Bromeliaceae) Fruit Extract in Rats
Several species of the family Bromeliaceae are characterized by the production of proteases in unusual amounts, especially in fruits. Bromelain, an extract rich in cysteine endo-peptidases obtained from Ananas comosus L., and a few other proteases have been used as anti-infl ammatory agents for some years, but bromelain is still mainly being used as alternative and/or complementary therapy to the treatment with glucocorticoids, nonsteroi-dal antirheumatics, and immunomodulators. In this study, the anti-infl ammatory action of a partially purifi ed extract from Pseudananas macrodontes (Morr.) Harms fruits (PPEPm) is presented, whose main components are cysteine endopeptidases. The effect of PPEPm was assessed in carrageenan-induced and serotonin-induced rat paw edema, as well as in the cotton pellet granuloma model. Doses with equal proteolytic activity of PPEPm and bromelain produced signifi cantly similar anti-infl ammatory responses in the acute infl ammatory models assayed, supporting the hypothesis that proteolytic activity could be responsible for the anti-infl ammatory action. On the contrary, comparable anti-infl ammatory effects of PPEPm and bromelain in the chronic infl ammatory assay required a much lower proteolytic activity content of PPEPm, which could be due to a differential affi nity for the protein target involved in this process.Facultad de Ciencias Exacta
Timelapse
We discuss the existence in an arbitrary frame of a finite time for the
transformation of an initial quantum state into another e.g. in a decay.
This leads to the introduction of a timelapse in analogy with
the lifetime of a particle. An argument based upon the Heisenberg uncertainty
principle suggests the value of . Consequences for the
exponential decay formula and the modifications that introduces
into the Breit-Wigner mass formula are described.Comment: 5 pages [2 figs], ReV-Te
Evaluation of Anti-Inflammatory Activity of Pseudananas macrodontes (Morr.) Harms (Bromeliaceae) Fruit Extract in Rats
Several species of the family Bromeliaceae are characterized by the production of proteases in unusual amounts, especially in fruits. Bromelain, an extract rich in cysteine endo-peptidases obtained from Ananas comosus L., and a few other proteases have been used as anti-infl ammatory agents for some years, but bromelain is still mainly being used as alternative and/or complementary therapy to the treatment with glucocorticoids, nonsteroi-dal antirheumatics, and immunomodulators. In this study, the anti-infl ammatory action of a partially purifi ed extract from Pseudananas macrodontes (Morr.) Harms fruits (PPEPm) is presented, whose main components are cysteine endopeptidases. The effect of PPEPm was assessed in carrageenan-induced and serotonin-induced rat paw edema, as well as in the cotton pellet granuloma model. Doses with equal proteolytic activity of PPEPm and bromelain produced signifi cantly similar anti-infl ammatory responses in the acute infl ammatory models assayed, supporting the hypothesis that proteolytic activity could be responsible for the anti-infl ammatory action. On the contrary, comparable anti-infl ammatory effects of PPEPm and bromelain in the chronic infl ammatory assay required a much lower proteolytic activity content of PPEPm, which could be due to a differential affi nity for the protein target involved in this process.Facultad de Ciencias Exacta
Experimental Study of the Effects of Three Types of Meat on Endothelial Function in a Group of Healthy Volunteers
Background: There is a relationship between atherosclerotic risk factors and increased vascular production of reactive oxygen species (ROS). Oxidized LDL and ROS may directly cause endothelial dysfunction by reducing endothelial nitric oxide (NO) bioavailability. The semi-essential amino acid L-arginine is the only substrate for NO synthesis in vascular endothelial cells. Therefore, this amino acid improves endothelial function and plays a role in the prevention and/or treatment of multiple cardiovascular diseases: atherosclerosis, hypertension, diabetes and so on. To determine the effects of three different protein matrices (250 g Fillet of Beef, FB; Chicken Raised on the Ground, CRG; Free-Range Chicken, FRC) with a known content of arginine on the cardiovascular workload, vascular compliance and urinary excretion of some parameters of endothelial function as TGF–Beta, NO (nitrate e nitrite) in a group of healthy volunteers. Materials and methods: We enrolled 10 men to study the behavior of Systolic, Diastolic, Mean, and Pulse Blood Pressure, of Vascular Resistances, of Macro and Micro Vascular Elasticity, of urinary excretion of TGF-β and Nitric Oxide as ratio of creatinine before and after two hours of each meal. The cardiovascular parameters are determined by HDI/Pulse Wave CR 2000 (Hypertension Diagnostic Inc, Eagan, MN); TGF-β is analysed by Elisa method (R&D Systems) and NO by colorimetric method (Cayman). Results and Conclusion: The protein meal packed with CRG causes a significant decrease in diastolic blood pressure mean pressure and vascular resistance in urinary excretion of TGF. FB resulted in a significant decrease in vascular resistance and urinary excretion of NO, while significantly increasing the Pulse Pressure, heart rate and urinary excretion of TGF-β. FRC resulted in a significant reduction of macrovascular elasticity; increase the urinary excretion of TGF and Pulse Pressure. We can conclude that CRG meat looks better both in terms of metabolic and cardiovascular load especially at endothelial level
Dirac Equation Studies in the Tunnelling Energy Zone
We investigate the tunnelling zone V0 < E < V0+m for a one-dimensional
potential within the Dirac equation. We find the appearance of superluminal
transit times akin to the Hartman effect.Comment: 12 pages, 4 figure
The omega rho pi coupling in the VMD model revisited
We determine the value of the \omega -\rho- \pi mesons coupling
(g_{\omega\rho\pi}), in the context of the vector meson dominance model, from
radiative decays, the \omega \rightarrow 3\pi decay width and the e^+e^-
\rightarrow 3\pi cross section. For the last two observables we consider the
effect of either a heavier resonance (\rho'(1450)) or a contact term. A
weighted average of the results from the set of observables yields
g_{\omega\rho\pi} =14.7 \pm 0.1 GeV^{-1} in absence of those contributions, and
g_{\omega\rho\pi} =11.9 \pm 0.2 GeV^{-1} or g_{\omega\rho\pi} =11.7 \pm 0.1
GeV^{-1} when including the \rho' or contact term respectively. The inclusion
of these additional terms makes the estimates from the different observables to
lay in a more reduced range. Improved measurements of these observables and the
\rho'(1450) meson parameters are needed to give a definite answer on the
pertinence of the inclusion of this last one in the considered processes.Comment: 14 pages, 5 figures. Extended analysis including SND and CMD2 data.
References added. Matches published versio
Potential Scattering in Dirac Field Theory
We develop the potential scattering of a spinor within the context of
perturbation field theory. As an application, we reproduce, up to second order
in the potential, the diffusion results for a potential barrier of quantum
mechanics. An immediate consequence is a simple generalization to arbitrary
potential forms, a feature not possible in quantum mechanics.Comment: 7 page
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