Effect of recombinant TRAIL in a murine co-culture system of osteoclastogenesis

Although some experimental evidence has implicated the TRAIL/TRAIL-receptor system in the regulation of osteoclastogenesis, the only available studies performed so far have been performed on isolated pre-osteoclasts, induced to differentiate by the addition of recombinant RANKL and M-CSF. Using a more physiological co-culture system in the absence of exogenous cytokines, we have here demonstrated that recombinant TRAIL inhibits osteoclast formation, but only at relatively high concentrations (500 ng/mL)

Exponential mapping for non semisimple quantum groups

The concept of universal T matrix, recently introduced by Fronsdal and Galindo in the framework of quantum groups, is here discussed as a generalization of the exponential mapping. New examples related to inhomogeneous quantum groups of physical interest are developed, the duality calculations are explicitly presented and it is found that in some cases the universal T matrix, like for Lie groups, is expressed in terms of usual exponential series.Comment: 12 page

On a nonstandard two-parametric quantum algebra and its connections with Up,q(gl(2))U_{p,q}(gl(2)) and Up,q(gl(1∣1))U_{p,q}(gl(1|1))

A quantum algebra $U_{p,q}(\zeta ,H,X_\pm )$ associated with a nonstandard $R$-matrix with two deformation parameters$(p,q)$ is studied and, in particular, its universal ${\cal R}$-matrix is derived using Reshetikhin's method. Explicit construction of the $(p,q)$-dependent nonstandard $R$-matrix is obtained through a coloured generalized boson realization of the universal ${\cal R}$-matrix of the standard $U_{p,q}(gl(2))$ corresponding to a nongeneric case. General finite dimensional coloured representation of the universal ${\cal R}$-matrix of $U_{p,q}(gl(2))$ is also derived. This representation, in nongeneric cases, becomes a source for various $(p,q)$-dependent nonstandard $R$-matrices. Superization of $U_{p,q}(\zeta , H,X_\pm )$ leads to the super-Hopf algebra $U_{p,q}(gl(1|1))$. A contraction procedure then yields a $(p,q)$-deformed super-Heisenberg algebra $U_{p,q}(sh(1))$ and its universal ${\cal R}$-matrix.Comment: 17pages, LaTeX, Preprint No. imsc-94/43 Revised version: A note added at the end of the paper correcting and clarifying the bibliograph

Graded Contractions of Affine Kac-Moody Algebras

The method of graded contractions, based on the preservation of the automorphisms of finite order, is applied to the affine Kac-Moody algebras and their representations, to yield a new class of infinite dimensional Lie algebras and representations. After the introduction of the horizontal and vertical gradings, and the algorithm to find the horizontal toroidal gradings, I discuss some general properties of the graded contractions, and compare them with the In\"on\"u-Wigner contractions. The example of $\hat A_2$ is discussed in detail.Comment: 23 pages, Ams-Te

Coherent and squeezed states of quantum Heisenberg algebras

Starting from deformed quantum Heisenberg Lie algebras some realizations are given in terms of the usual creation and annihilation operators of the standard harmonic oscillator. Then the associated algebra eigenstates are computed and give rise to new classes of deformed coherent and squeezed states. They are parametrized by deformed algebra parameters and suitable redefinitions of them as paragrassmann numbers. Some properties of these deformed states also are analyzed.Comment: 32 pages, 3 figure

Universal RR--matrices for non-standard (1+1) quantum groups

A universal quasitriangular $R$--matrix for the non-standard quantum (1+1) Poincar\'e algebra $U_ziso(1,1)$ is deduced by imposing analyticity in the deformation parameter $z$. A family $g_\mu$ of ``quantum graded contractions" of the algebra $U_ziso(1,1)\oplus U_{-z}iso(1,1)$ is obtained; this set of quantum algebras contains as Hopf subalgebras with two primitive translations quantum analogues of the two dimensional Euclidean, Poincar\'e and Galilei algebras enlarged with dilations. Universal $R$--matrices for these quantum Weyl algebras and their associated quantum groups are constructed.Comment: 12 pages, LaTeX

Activation of PKC-ε counteracts maturation and apoptosis of HL-60 myeloid leukemic cells in response to TNF family members

Protein kinase C (PKC)-ε, a component of the serine/threo-nine PKC family, has been shown to influence the survival and differentiation pathways of normal hematopoietic cells. Here, we have modulated the activity of PKC-ε with specific small molecule activator or inhibitor peptides. PKC-ε inhibitor and activator peptides showed modest effects on HL-60 maturation when added alone, but PKC-ε activator peptide significantly counteracted the pro-maturative activity of tumor necrosis factor (TNF)-α towards the monocytic/macrophagic lineage, as evaluated in terms of CD14 surface expression and morphological analyses. Moreover, while PKC-ε inhibitor peptide showed a reproducible increase of TNF-related apoptosis inducing ligand (TRAIL)-induced apoptosis, PKC-ε activator peptide potently counteracted the pro-apoptotic activity of TRAIL. Taken together, the anti-maturative and anti-apoptotic activities of PKC-ε envision a potentially important proleukemic role of this PKC family member

Quantum limit of deterministic theories

We show that the quantum linear harmonic oscillator can be obtained in the large $N$ limit of a classical deterministic system with SU(1,1) dynamical symmetry. This is done in analogy with recent work by G.'t Hooft who investigated a deterministic system based on SU(2). Among the advantages of our model based on a non--compact group is the fact that the ground state energy is uniquely fixed by the choice of the representation.Comment: 4 pages, 2 figures, minor corrections added. To appear in the Proceedings of Waseda International Symposium on Fundamental Physics: "New Perspectives in Quantum Physics", 12-15 November 2002, Waseda University, Tokyo, Japa

Avaliação simultânea das membranas plasmática, acrossomal e mitocondrial de espermatozoides de carneiros por sondas fluorescentes

Neste experimento, foi definida uma combinação de sondas fluorescentes: iodeto de propídio (PI), aglutinina de Pisum sativum conjugada ao isotiocionato de fluoresceína (FITC-PSA) e JC-1. Para esta proposta, quatro ejaculados de três carneiros (n=12), que apresentavam motilidade >80% e alterações morfológicas <10%, foram diluídos em meio TALP e divididos em duas alíquotas. Uma alíquota foi submetida a três ciclos de flash frozen e descongelação, para induzir danos nas membranas celulares e distúrbios na função mitocondrial. Três tratamentos foram preparados com as seguintes proporções preestabelecidas de sêmen fresco: sêmen submetido a flash frozen: 0:100 (T0), 50:50 (T50) e 100:0 (T100). As amostras foram coradas no protocolo proposto e avaliadas por microscopia de epifluorescência. Para integridade de membrana plasmática, detectada pela sonda PI, foi obtida a equação: v=1,09+0,86X (R2=0,98). O acrossomo intacto, verificado pela sonda FITC-PSA, produziu a equação: v=2,76+0,92X (R2=0,98). O alto potencial de membrana mitocondrial, marcada em vermelho-alaranjado pelo JC-1, foi estimado pela equação: v=1,90+0,90X (R2=0,98). As equações lineares resultantes demonstraram que a técnica é eficiente e prática para avaliação simultânea das membranas plasmática, acrossomal e mitocondrial em espermatozoides de carneirosIn this experiment, it was defined a protocol of fluorescent probes combination: propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA), and JC-1. For this purpose, four ejaculates from three different rams (n=12), all showing motility 80% and abnormal morphology 10%, were diluted in TALP medium and split into two aliquots. One of the aliquots was flash frozen and thawed in three continuous cycles, to induce damage in cellular membranes and to disturb mitochondrial function. Three treatments were prepared with the following fixed ratios of fresh semen:flash frozen semen: 0:100 (T0), 50:50 (T50), and 100:0 (T100). Samples were stained in the proposal protocol and evaluated by epifluorescence microscopy. For plasmatic membrane integrity, detected by PI probe, it was obtained the equation: Ŷ=1.09+0.86X (R2=0.98). The intact acrosome, verified by the FITC-PSA probe, produced the equation: Ŷ=2.76+0.92X (R2=0.98). The high mitochondrial membrane potential, marked in red-orange by JC-1, was estimated by the equation: Ŷ=1.90+0.90X (R2=0.98). The resulting linear equations demonstrate that this technique is efficient and practical for the simultaneous evaluations of the plasmatic, acrosomal, and mitochondrial membranes in ram spermatozoa.FAPESP 00/14653-6 e 01/13940-