Conceivable difference in the anti-inflammatory mechanisms of lipocortins 1 and 5

Human recombinant lipocortins (LCT) 1 and 5 have been expressed in a yeast secretion vector and purified by ion exchange chromatography. The action of the proteins has been investigated in two models of experimental acute inflammation in the rat: carrageenin induced paw oedema and zymosan induced pleurisy. The effects of the proteins on PGE2 release in vitro by rat macrophages stimulated with zymosan and on rat neutrophil chemotaxis induced by FMLP have also been assessed. LCT-1 significantly inhibited both paw swelling in carrageenin oedema and leukocyte migration in zymosan pleurisy. Moreover it showed a dose dependent, inhibitory effect on PGE2 release. Neutrophil chemotaxis was only weakly affected by LCT-1. Conversely LCT-5 did not reduce carrageenin oedema and slightly inhibited PGE2 release, but showed profound, dose dependent inhibitory activity on leukocyte migration in zymosan pleurisy and on neutrophil chemotaxis. These data suggest that LCT-1 acts mainly by interfering with arachidonic acid metabolism via the inhibition of phospholipase A2. The anti-inflammatory activity of LCT-5, at variance with LCT-1, may be due to a direct effect on cell motility in addition to the interference with arachidonic acid metabolism

Inhibition of smooth muscle contraction and platelet aggregation by peptide 204–212 of lipocortin 5: an attempt to define some structure requirements

Peptide 204–212 of lipocortin (LC) 5 inhibited porcine pancreatic phospholipase A2 (PLA2) induced rat stomach strip contractions and ADP induced rabbit platelet aggregation in a concentration dependent manner (IC30 of 10 μM and 400 μM, respectively). The first two amino acids are not necessary since the eptapeptide 206–212 was equipotent in both assays (IC30 of 12.5 μM and 420 μM). Of the two pentapeptides 204–208 and 208–212 only the latter showed inhibitory activity in both models although the potency was much reduced (IC30 of 170 μM and 630 μM) compared with that of the parent nonapeptide. Comparison of peptide 204–212 effects with those of its analogues on LC1 and LC2 indicate that lysine 208 and aspartic acid 211 are essential in order to maintain a fully active nonapeptide

Perspectives of social entrepreneurship in Portugal: comparison and contrast with international theoretical approaches

The aim of this article is to present and discuss the perspectives of social entrepreneurship conveyed by third sector organizations in Portugal in the context of the main international theoretical approaches. As part of a research project on social entrepreneurship in Portugal, the article analyses the content of 20 semi-structured interviews with key actors within the Portuguese third sector. It is assumed that the roles these actors play are a clear indicator of the importance their views can hold in defining the social entrepreneurship field in Portugal. This analysis enables us to conclude that heterogeneous views and blurred defined boundaries frame the debate on social entrepreneurship’s processes and definitions, with some actors even rejecting it in favour of other concepts such as “social economy” or “solidarity economy”. Nevertheless, the central issues that arose are associated with the individual qualities of the entrepreneur, as well as the sustainability of the initiatives

Exploring The Potential of Probabilistic Shaping Technique in Quantum Key Distribution Systems

We investigated the role of probabilistic shaping in the optimization of the secure key rate of a continuous variable quantum key distribution system with discrete modulation in both homodyne and heterodyne scheme

Sulfates on Mars as Markers of Aqueous Processes: An Integrated Multidisciplinary Study of Minerals, Mars Analog sites and Recent Mission Data

Our analyses of sulfate minerals, analog sites, and Martian spectra and spectral images is focused on characterization of the Martian surface and in particular identification of aqueous processes there

Sequential release of TNFα and phospholipase A2 in a rat model of LPS-induced pleurisy

The levels of extracellular phospholipase A2 (sPLA2) and TNFα, and cell accumulation were measured in the pleural washings obtained at different times following the induction of Escherichia coli lipopolysaccharide (LPS, 100 μg/cavity) pleurisy in rats. TNFα peaked at 2 hours (3036 ± 160.3 units/ml) and decreased thereafter. Conversely, levels of sPLA2 peaked at 48 hours (1.97 ± 0.64 ng/ml) and were increased further (14.02 ± 4.16 ng/ml) by pretreatment with anti-TNFα antibody. Cell accumulation was not affected by antibody pretreatment. These data indicate that the sPLA2 enzyme is involved in LPS-induced pleurisy. The enzyme seems not to be stimulated by TNFα which may be involved in the downregulation of sPLA2 in this model of inflammation

Probabilistic Amplitude Shaping for Continuous-Variable Quantum Key Distribution with Discrete Modulation over a Wiretap Channel

To achieve the maximum information transfer and face a possible eavesdropper, the samples transmitted in continuous-variable quantum key distribution (CV-QKD) protocols are to be drawn from a continuous Gaussian distribution. As a matter of fact, in practical implementations the transmitter has a finite (power) dynamics and the Gaussian sampling can be only approximated. This requires the quantum protocols to operate at small powers. In this paper, we show that a suitable probabilistic amplitude shaping of a finite set of symbols allows to approximate at will the optimal channel capacity also for increasing average powers. We investigate the feasibility of this approach in the framework of CV-QKD, propose a protocol employing discrete quadrature amplitude modulation assisted with probabilistic amplitude shaping, and we perform the key generation rate analysis assuming a wiretap channel and lossless homodyne detection

The human otitis media with effusion: a numerical-based study

Otitis media is a group of inflammatory diseases of the middle ear. Acute otitis media and otitis media with effusion (OME) are its two main types of manifestation. Otitis media is common in children and can result in structural alterations in the middle ear which will lead to hearing losses. This work studies the effects of an OME on the sound transmission from the external auditory meatus to the inner ear. The finite element method was applied on the present biomechanical study. The numerical model used in this work was built based on the geometrical information obtained from The visible ear project. The present work explains the mechanisms by which the presence of fluid in the middle ear affects hearing by calculating the magnitude, phase and reduction of the normalized umbo velocity and also the magnitude and phase of the normalized stapes velocity. A sound pressure level of 90 dB SPL was applied at the tympanic membrane. The harmonic analysis was performed with the auditory frequency varying from 100 Hz to 10 kHz. A decrease in the response of the normalized umbo and stapes velocity as the tympanic cavity was filled with fluid was obtained. The decrease was more accentuated at the umbo.info:eu-repo/semantics/publishedVersio