On a class of bivariate second-order linear partial difference equations and their monic orthogonal polynomial solutions

AbstractIn this paper we classify the bivariate second-order linear partial difference equations, which are admissible, potentially self-adjoint, and of hypergeometric type. Using vector matrix notation, explicit expressions for the coefficients of the three-term recurrence relations satisfied by monic orthogonal polynomial solutions are obtained in terms of the coefficients of the partial difference equation. Finally, we make a compilation of the examples existing in the literature belonging to the class analyzed in this paper, namely bivariate Charlier, Meixner, Kravchuk and Hahn orthogonal polynomials

Evidence for fungal infection in cerebrospinal fluid and brain tissue from patients with amyotrophic lateral sclerosis

Among neurogenerative diseases, amyotrophic lateral sclerosis (ALS) is a fatal illness characterized by a progressive motor neuron dysfunction in the motor cortex, brainstem and spinal cord. ALS is the most common form of motor neuron disease; yet, to date, the exact etiology of ALS remains unknown. In the present work, we have explored the possibility of fungal infection in cerebrospinal fluid (CSF) and in brain tissue from ALS patients. Fungal antigens, as well as DNA from several fungi, were detected in CSF from ALS patients. Additionally, examination of brain sections from the frontal cortex of ALS patients revealed the existence of immunopositive fungal antigens comprising punctate bodies in the cytoplasm of some neurons. Fungal DNA was also detected in brain tissue using PCR analysis, uncovering the presence of several fungal species. Finally, proteomic analyses of brain tissue demonstrated the occurrence of several fungal peptides. Collectively, our observations provide compelling evidence of fungal infection in the ALS patients analyzed, suggesting that this infection may play a part in the etiology of the disease or may constitute a risk factor for these patientsThe financial support of Fundación ONCE (Organización Nacional de Ciegos Españoles) is acknowledged. We acknowledge an institutional grant to Centro de Biología Molecular “Severo Ochoa” from the Fundación Ramón Arece

Macrophage: From Recognition of Foreign Agents to Late Phagocytosis

The main line of defense that exists to eliminate foreign agents falls on phagocytic cells (neutrophils, dendritic cell, and macrophages), and it does so through phagocytosis, a complex cellular mechanism that occurs after the recognition and binding of the ligand by cellular receptors. Macrophages are part of a diverse lineage of innate immune cells. Once a macrophage receptor binds its ligand, a coordinated intracellular signaling cascade is activated to the clearance or otherwise of the foreign agent. Objects removed by macrophage phagocytosis include dead or dying host cells, cells opsonized with antibodies, and specific pathogens such as bacteria, fungi, parasites, and viruses. Currently, phagocytic macrophages have been shown to contribute to the killing of cancer cells, inflammatory bowel disease, atherosclerosis, Alzheimer’s disease, and schizophrenia. For this reason, phagocytic macrophages are important in critical participation for health and disease

NP7 protects from cell death induced by oxidative stress in neuronal and glial midbrain cultures from parkin null mice

AbstractParkin mutations produce Parkinson’s disease (PD) in humans and nigrostriatal dopamine lesions related to increased free radicals in mice. We examined the effects of NP7, a synthetic, marine derived, free radical scavenger which enters the brain, on H2O2 toxicity in cultured neurons and glia from wild-type (WT) and parkin null mice (PK-KO).NP7, 5–10μM, prevented the H2O2 induced apoptosis and necrosis of midbrain neuronal and glial cultures from WT and PK-KO mice. NP7 suppressed microglial activation and the H2O2 induced drop-out of dopamine neurons. Furthermore, NP7 prevented the increased phosphorylation of ERK and AKT induced by H2O2. NP7 may be a promising neuroprotector against oxidative stress in PD

Measurement of two-halo neutron transfer reaction p(11^{11}Li,9^{9}Li)t at 3AA MeV

The p(\nuc{11}{Li},\nuc{9}{Li})t reaction has been studied for the first time at an incident energy of 3$A$ MeV delivered by the new ISAC-2 facility at TRIUMF. An active target detector MAYA, build at GANIL, was used for the measurement. The differential cross sectionshave been determined for transitions to the \nuc{9}{Li} ground andthe first excited states in a wide range of scattering angles. Multistep transfer calculations using different \nuc{11}{Li} model wave functions, shows that wave functions with strong correlations between the halo neutrons are the most successful in reproducing the observation.Comment: 6 pages, 3 figures, submitted to Physical Review Letter

Distinct Actin and Lipid Binding Sites in Ysc84 Are Required during Early Stages of Yeast Endocytosis

During endocytosis in S. cerevisiae, actin polymerization is proposed to provide the driving force for invagination against the effects of turgor pressure. In previous studies, Ysc84 was demonstrated to bind actin through a conserved N-terminal domain. However, full length Ysc84 could only bind actin when its C-terminal SH3 domain also bound to the yeast WASP homologue Las17. Live cell-imaging has revealed that Ysc84 localizes to endocytic sites after Las17/WASP but before other known actin binding proteins, suggesting it is likely to function at an early stage of membrane invagination. While there are homologues of Ysc84 in other organisms, including its human homologue SH3yl-1, little is known of its mode of interaction with actin or how this interaction affects actin filament dynamics. Here we identify key residues involved both in Ysc84 actin and lipid binding, and demonstrate that its actin binding activity is negatively regulated by PI(4,5)P2. Ysc84 mutants defective in their lipid or actin-binding interaction were characterized in vivo. The abilities of Ysc84 to bind Las17 through its C-terminal SH3 domain, or to actin and lipid through the N-terminal domain were all shown to be essential in order to rescue temperature sensitive growth in a strain requiring YSC84 expression. Live cell imaging in strains with fluorescently tagged endocytic reporter proteins revealed distinct phenotypes for the mutants indicating the importance of these interactions for regulating key stages of endocytosis

Detecció de sibilacions en l'exploració física en Atenció Primària de Salut

A partir de la documentació clínica realitzem un estudi retrospectiu sobre una població infantil d'edats compreses entre 8 i 13 anys observada per un espai de temps superior a un any, a fi de valorar la prevalença d'asma i la hiperreactivitat bronquial. En el grup d'estudi foren practicades sistemàticament maniobres d'espiració forçada; en resultà una prevalença del 42% enfront del 20% en el grup de comparació (p < 0,001). Atesa la transcendència clínica i terapèutica de la detecció de roncors i sibilacions en l'exploració física creiem convenient la pràctica sistemàtica de maniobres d'espiració forçada en tots els pacients que presenten tos o altres signes d'infecció respiratòria