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We investigated the ability of human peripheral CD4 ؉ cells to express CD94 and NKG2 molecules as... more We investigated the ability of human peripheral CD4 ؉ cells to express CD94 and NKG2 molecules as a consequence of CD3-mediated activation. Using highly purified peripheral CD4 ؉ T cells, we found expression of both CD94 and NKG2A 15 days after CD3-mediated stimulation of cells. We also determined by reverse transcriptase-PCR that all gene members of NKG2 familynamely, NKG2A, -C, -D, and -E-are sequentially expressed on CD4 ؉ cells. We found that this expression is tightly regulated by cytokines, and we identified transforming growth factor-1 and interleukin-10 as the main factors that, on CD3-dependent stimulation, positively contribute to the expression of CD94 and NKG2A on CD4 ؉ cells. We also investigated the functional role of NKG2A and found that coligation of CD3 and NKG2A by specific monoclonal antibodies results in significant inhibition of interferon ␥ and tumor necrosis factor ␣ production by stimulated CD4 ؉ cells. The presence and function of these receptors on CD4 ؉ lymphocytes support a more general role for NKG2 molecules, whose functions were originally thought to be confined to cytotoxic cells, in the immune system. J. Leukoc. Biol. 70: 219 -224; 2001.
We show that the degree of the Alexander polynomial of an irreducible plane algebraic curve with ... more We show that the degree of the Alexander polynomial of an irreducible plane algebraic curve with nodes and cusps as the only singularities does not exceed 5over3d−2{5 \over 3}d-25over3d−2 where ddd is the degree of the curve. We also show that the Alexander polynomial DeltaC(t)\Delta_C(t)DeltaC(t) of an irreducible curve C=F=0subsetmathbbP2C=\{F=0\}\subset \mathbb P^2C=F=0subsetmathbbP2 whose singularities are nodes and cusps is non-trivial if and only if there exist homogeneous polynomials fff, ggg, and hhh such that f3+g2+Fh6=0f^3+g^2+Fh^6=0f3+g2+Fh6=0. This is obtained as a consequence of the correspondence, described here, between Alexander polynomials and ranks of Mordell-Weil groups of certain threefolds over function fields. All results also are extended to the case of reducible curves and Alexander polynomials DeltaC,epsilon(t)\Delta_{C,\epsilon}(t)DeltaC,epsilon(t) corresponding to surjections epsilon:pi1(mathbbP2setminusC0cupC)rightarrowmathbbZ\epsilon: \pi_1(\mathbb P^2\setminus C_0 \cup C) \rightarrow \mathbb Zepsilon:pi1(mathbbP2setminusC0cupC)rightarrowmathbbZ, where C0C_0C0 is a line at infinity. In addition, we provide a detailed description of the collection of relations of FFF as above in terms of the multiplicities of the roots of DeltaC,epsilon(t)\Delta_{C,\epsilon}(t)DeltaC,epsilon(t). This generalization is made in the context of a larger class of singularities i.e. those which lead to rational orbifolds of elliptic type.
Duke Mathematical Journal, 2003
In this paper we prove that braid monodromy of an affine plane curve determines the topology of a... more In this paper we prove that braid monodromy of an affine plane curve determines the topology of a related projective plane curve. 1 2 E. ARTAL, J. CARMONA, AND J.I. COGOLLUDO
Comptes Rendus De L Academie Des Sciences Serie I-mathematique, 2000
Environmental Research, 2008
Exposure to particulate matter (PM) may alter lung homeostasis inducing changes in fluid balance ... more Exposure to particulate matter (PM) may alter lung homeostasis inducing changes in fluid balance and host defense. Bioavailability of soluble PM compounds like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and transition metals has been shown to play a key role in lung injury. We have previously characterized the size, shape, and chemical components of urban air particles from Buenos Aires (UAP-BA) and their biological impact on lungs. Herein, we evaluate the possible toxic effect of UAP-BAsoluble fraction (UAP-BAsf) on pulmonary cells obtained from young (1-2 months old) and aged (9-12 months old) Wistar rats using phagocytosis, oxidant-antioxidant generation, and apoptosis as endpoints. UAP-BA were collected in downtown BA and residual oil fly ash (ROFA), employed as a positive control, was collected from Boston Edison Co., Mystic Power Plant, Mystic, CT, USA. Both particle-soluble fractions (sf) were employed at concentrations ranging from 0 to 100 mg/mL. UAP-BAsf and ROFAsf even at the lowest dose assayed (10 mg/mL) showed in both lung cell populations the ability to stimulate phagocytosis and increase superoxide anion (O 2 À ) generation. Both types of air particles caused a marked intracellular oxidant stress in aged pulmonary cells that may contribute to subsequent cell activation and production of proinflammatory mediators, leading to cell dysfunction. These data suggest that the impact of UAP-BAsf on phagocytosis, oxidant radical generation, and apoptosis is clearly dependent on the maturational state of the animal and might have different mechanisms of action. r
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Journal of Hepatology, 2006
Corrigendum to ''Immunosuppression without steroids in liver transplantation is safe and reduces ... more Corrigendum to ''Immunosuppression without steroids in liver transplantation is safe and reduces infection and metabolic complications: Results from a prospective multicenter randomized study'' [J Hepatol 44 (2006) 710-716]
A new clusters labelling strategy, which combines the computation of the Davies-Bouldin index of ... more A new clusters labelling strategy, which combines the computation of the Davies-Bouldin index of the clustering and the centroid diameters of the clusters is proposed for application in anomaly based intrusion detection systems (IDS). The aim of such a strategy is to detect compact clusters containing very similar vectors and these are highly likely to be attack vectors. Experimental results comparing the effectiveness of a multiple classifier IDS with such a labelling strategy and that of the classical cardinality labelling based IDS show that the proposed strategy behaves much better in a heavily attacked environment where massive attacks are present. The parameters of the labelling algorithm can be varied in order to adapt to the conditions in the monitored network.
We investigated the ability of human peripheral CD4 ؉ cells to express CD94 and NKG2 molecules as... more We investigated the ability of human peripheral CD4 ؉ cells to express CD94 and NKG2 molecules as a consequence of CD3-mediated activation. Using highly purified peripheral CD4 ؉ T cells, we found expression of both CD94 and NKG2A 15 days after CD3-mediated stimulation of cells. We also determined by reverse transcriptase-PCR that all gene members of NKG2 familynamely, NKG2A, -C, -D, and -E-are sequentially expressed on CD4 ؉ cells. We found that this expression is tightly regulated by cytokines, and we identified transforming growth factor-1 and interleukin-10 as the main factors that, on CD3-dependent stimulation, positively contribute to the expression of CD94 and NKG2A on CD4 ؉ cells. We also investigated the functional role of NKG2A and found that coligation of CD3 and NKG2A by specific monoclonal antibodies results in significant inhibition of interferon ␥ and tumor necrosis factor ␣ production by stimulated CD4 ؉ cells. The presence and function of these receptors on CD4 ؉ lymphocytes support a more general role for NKG2 molecules, whose functions were originally thought to be confined to cytotoxic cells, in the immune system. J. Leukoc. Biol. 70: 219 -224; 2001.
We show that the degree of the Alexander polynomial of an irreducible plane algebraic curve with ... more We show that the degree of the Alexander polynomial of an irreducible plane algebraic curve with nodes and cusps as the only singularities does not exceed 5over3d−2{5 \over 3}d-25over3d−2 where ddd is the degree of the curve. We also show that the Alexander polynomial DeltaC(t)\Delta_C(t)DeltaC(t) of an irreducible curve C=F=0subsetmathbbP2C=\{F=0\}\subset \mathbb P^2C=F=0subsetmathbbP2 whose singularities are nodes and cusps is non-trivial if and only if there exist homogeneous polynomials fff, ggg, and hhh such that f3+g2+Fh6=0f^3+g^2+Fh^6=0f3+g2+Fh6=0. This is obtained as a consequence of the correspondence, described here, between Alexander polynomials and ranks of Mordell-Weil groups of certain threefolds over function fields. All results also are extended to the case of reducible curves and Alexander polynomials DeltaC,epsilon(t)\Delta_{C,\epsilon}(t)DeltaC,epsilon(t) corresponding to surjections epsilon:pi1(mathbbP2setminusC0cupC)rightarrowmathbbZ\epsilon: \pi_1(\mathbb P^2\setminus C_0 \cup C) \rightarrow \mathbb Zepsilon:pi1(mathbbP2setminusC0cupC)rightarrowmathbbZ, where C0C_0C0 is a line at infinity. In addition, we provide a detailed description of the collection of relations of FFF as above in terms of the multiplicities of the roots of DeltaC,epsilon(t)\Delta_{C,\epsilon}(t)DeltaC,epsilon(t). This generalization is made in the context of a larger class of singularities i.e. those which lead to rational orbifolds of elliptic type.
Duke Mathematical Journal, 2003
In this paper we prove that braid monodromy of an affine plane curve determines the topology of a... more In this paper we prove that braid monodromy of an affine plane curve determines the topology of a related projective plane curve. 1 2 E. ARTAL, J. CARMONA, AND J.I. COGOLLUDO
Comptes Rendus De L Academie Des Sciences Serie I-mathematique, 2000
Environmental Research, 2008
Exposure to particulate matter (PM) may alter lung homeostasis inducing changes in fluid balance ... more Exposure to particulate matter (PM) may alter lung homeostasis inducing changes in fluid balance and host defense. Bioavailability of soluble PM compounds like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and transition metals has been shown to play a key role in lung injury. We have previously characterized the size, shape, and chemical components of urban air particles from Buenos Aires (UAP-BA) and their biological impact on lungs. Herein, we evaluate the possible toxic effect of UAP-BAsoluble fraction (UAP-BAsf) on pulmonary cells obtained from young (1-2 months old) and aged (9-12 months old) Wistar rats using phagocytosis, oxidant-antioxidant generation, and apoptosis as endpoints. UAP-BA were collected in downtown BA and residual oil fly ash (ROFA), employed as a positive control, was collected from Boston Edison Co., Mystic Power Plant, Mystic, CT, USA. Both particle-soluble fractions (sf) were employed at concentrations ranging from 0 to 100 mg/mL. UAP-BAsf and ROFAsf even at the lowest dose assayed (10 mg/mL) showed in both lung cell populations the ability to stimulate phagocytosis and increase superoxide anion (O 2 À ) generation. Both types of air particles caused a marked intracellular oxidant stress in aged pulmonary cells that may contribute to subsequent cell activation and production of proinflammatory mediators, leading to cell dysfunction. These data suggest that the impact of UAP-BAsf on phagocytosis, oxidant radical generation, and apoptosis is clearly dependent on the maturational state of the animal and might have different mechanisms of action. r
[
Journal of Hepatology, 2006
Corrigendum to ''Immunosuppression without steroids in liver transplantation is safe and reduces ... more Corrigendum to ''Immunosuppression without steroids in liver transplantation is safe and reduces infection and metabolic complications: Results from a prospective multicenter randomized study'' [J Hepatol 44 (2006) 710-716]
A new clusters labelling strategy, which combines the computation of the Davies-Bouldin index of ... more A new clusters labelling strategy, which combines the computation of the Davies-Bouldin index of the clustering and the centroid diameters of the clusters is proposed for application in anomaly based intrusion detection systems (IDS). The aim of such a strategy is to detect compact clusters containing very similar vectors and these are highly likely to be attack vectors. Experimental results comparing the effectiveness of a multiple classifier IDS with such a labelling strategy and that of the classical cardinality labelling based IDS show that the proposed strategy behaves much better in a heavily attacked environment where massive attacks are present. The parameters of the labelling algorithm can be varied in order to adapt to the conditions in the monitored network.