Browsing by Author "Aldunate, R"

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    A major portion of synaptic basal lamina acetylcholinesterase is detached by high salt- and heparin-containing buffers from rat diaphragm muscle and Torpedo electric organ
    (1998) Casanueva, OI; García-Huidobro, T; Campos, EO; Aldunate, R; Garrido, J; Inestrosa, NC
    Collagen-tailed asymmetric acetylcholinesterase (AChE) forms are believed to be anchored to the synaptic basal lamina via electrostatic: interactions involving proteoglycans. However, it was recently found that in avian and rat muscles, high ionic strength or polyanionic buffers could not detach AChE: from cell-surface clusters and that these buffers solubilized intracellular non-junctional asymmetric AChE rather than synaptic: forms of the enzyme. In the present study, asymmetric AChE forms were specifically solubilized by ionic buffers from sg synaptic basal! lamina-enriched fractions, largely devoid of intracellular material, obtained from the electric organ of Torpedo californica and the end plate regions of rat diaphragm muscle, Furthermore, foci of AChE activity were seen to diminish in size, number, and staining intensity when the rat synaptic basal lamina-enriched preparations were treated with the extraction buffers, Pn the case of Torpedo, almost all the AChE activity was removed from the pure basal lamina sheets. We therefore conclude that a major portion of extracellular collagen-tailed AChE is extractable from rat and Torpedo synaptic basal lamina by high ionic strength and heparin buffers,;although some non-extractable AChE activity remains associated with the junctional regions.
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    Human-like rodent amyloid-β-peptide determines Alzheimer pathology in aged wild-type Octodon degu
    (2005) Inestrosa, NC; Reyes, AE; Chacón, MA; Cerpa, W; Villalón, A; Montiel, J; Merabachvili, G; Aldunate, R; Bozinovic, F; Aboitiz, F
    It is generally accepted that human Alzheimer's disease (AD) neuropathology markers are completely absent in rodent brains. We report here that an aged wild-type South American rodent, Octodon degu, expresses neuronal beta-amyloid precursor protein (beta-APP695) displaying both intracellular and extracellular deposits of amyloid-beta-peptide (A beta), intracellular accumulations of tau-protein and ubiquitin, a strong astrocytic response and acetylcholinesterase (AChE)-rich pyramidal neurons. The high amino acid homology (97.5%) between deguA beta and humanA beta sequences is probably a major factor in the appearance of AD markers in this aged rodent. Our results indicate that aged 0. degu constitutes the first wild-type rodent model for neurodegenerative processes associated to AD. (c) 2004 Elsevier Inc. All rights reserved.
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    Peridomestic small mammals associated with confirmed cases of human hantavirus disease in southcentral Chile
    (2004) Torres-Pérez, F; Navarrete-Droguett, J; Aldunate, R; Yates, TL; Mertz, GJ; Vial, PA; Ferrés, M; Marquet, PA; Palma, RE
    Cases of human hantavirus disease have been reported in Chile since 1995, most of them in people living in rural and periurban areas. We conducted a peridomestic study of small mammals to evaluate the relationships between the presence of rodents with antibodies to Andes virus confirmed human cases of hantavirus pulmonary syndrome in southcentral Chile. The results of 20 sampled sites, which involved the capture of 272 mice over an 18-month period, showed the occurrence of 10 small mammal species, of which Oligoryzomys longicaudatus was the only seropositive species for hantavirus, with an intra-specific serologic rate of 10.4%.
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    Peripheral binding site is involved in the neurotrophic activity of acetylcholinesterase
    (1999) Muñoz, FJ; Aldunate, R; Inestrosa, NC
    ACETYLCHOLINESTERASE (AChE) catalyses the hydrolysis of the neurotransmitter acetylcholine and it has been implicated in several non-cholinergic actions, including neurite outgrowth and amyloid formation. We have studied the trophic function of brain AChE on neuronal cell metabolism and proliferation as well as the enzyme domain involved in such effects. Low AChE concentrations (0.1-2.5 nM) stimulated neurite outgrowth and induced cell proliferation as measured by MTT reduction and [H-3]thymidine incorporation. The action of AChE was not affected by edrophonium and tacrine both active site inhibitors, but it was abolished by propidium and gallamine, two peripheral anionic binding site (PAS) ligands. We conclude that the PAS domain of AChE is involved in the neurotrophic activity of the enzyme. (C) 1999 Lippincott Williams & Wilkins.
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    Robust mobile ad hoc space for collaboration to support disaster relief efforts involving critical physical infrastructure
    (ASCE-AMER SOC CIVIL ENGINEERS, 2006) Aldunate, R; Ochoa, SF; Pena Mora, F; Nussbaum, M
    When an extreme event hits an urban area, the efficiency and effectiveness of the first response have a profound effect on disaster relief efforts. The redefinition of the civil engineers' role and responsibilities as first response team members, along with an enhanced collaboration between disaster relief organizations, will greatly improve first response efforts and the securing of affected infrastructures. To improve collaboration efforts, the currently used radio systems-based interaction rnedium needs to be modified due to the impossibility of storing, retrieving, and transferring digital information, and limited support to implement information dissemination policies. This paper presents a reliable, transparent, and portable mobile ad hoc space for collaboration (MASC) based on a short range wireless communication platform to address these limitations in order to provide more consistent and efficient collaboration among first responders. The system was designed around a robust data redundancy core, and tested through software simulations and by conducting a search and rescue exercise involving civil engineers and firefighters. The simulation results highlight that the number of machines, the replication level, the size of the replication unit, and the wireless communication range are key design elements of the system in providing high availability. The search and rescue exercise allowed this research to confirm the high availability simulation results and to demonstrate that MASC is able to adequately manage and disseminate information in disaster scenarios. These encouraging results allow this research effort to conclude that MASC is able to address these new challenges.