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KEY POINTS: The state of central sensitization induced by the intradermic injection of capsaicin leads to structured (non-random) changes in functional connectivity between dorsal horn neuronal populations distributed along the spinal lumbar segments in anaesthetized cats. The capsaicin-induced changes in neuronal connectivity and the concurrent increase in secondary hyperalgesia are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. The effects of both capsaicin and lidocaine are greatly attenuated in spinalized preparations, showing that supraspinal influences play a significant role in the shaping of nociceptive-induced changes in dorsal horn functional neuronal connectivity. We conclude that changes in functional connectivity between segmental populations of dorsal horn neurones induced by capsaicin and lidocaine result from a cooperative adaptive interaction between supraspinal and spinal neuronal networks, a process that may have a relevant role in the pathogenesis of chronic pain and analgesia. ABSTRACT: Despite a profusion of information on the molecular and cellular mechanisms involved in the central sensitization produced by intense nociceptive stimulation, the changes in the patterns of functional connectivity between spinal neurones associated with the development of secondary hyperalgesia and allodynia remain largely unknown. Here we show that the state of central sensitization produced by the intradermal injection of capsaicin is associated with structured transformations in neuronal synchronization that lead to an enduring reorganization of the functional connectivity within a segmentally distributed ensemble of dorsal horn neurones. These changes are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. Lidocaine also reduces the capsaicin-induced facilitation of the spinal responses evoked by weak mechanical stimulation of the skin in the region of secondary but not primary hyperalgesia. The effects of both intradermic capsaicin and systemic lidocaine on the segmental correlation and coherence between ongoing cord dorsum potentials and on the responses evoked by tactile stimulation in the region of secondary hyperalgesia are greatly attenuated in spinalized preparations, showing that supraspinal influences are involved in the reorganization of the nociceptive-induced structured patterns of dorsal horn neuronal connectivity. We conclude that the structured reorganization of the functional connectivity between the dorsal horn neurones induced by capsaicin nociceptive stimulation results from cooperative interactions between supraspinal and spinal networks, a process that may have a relevant role in the shaping of the spinal state in the pathogenesis of chronic pain and analgesia.
Assuntos
Capsaicina/toxicidade , Hiperalgesia/fisiopatologia , Lidocaína/farmacologia , Rede Nervosa/fisiologia , Nociceptividade/fisiologia , Células do Corno Posterior/fisiologia , Anestésicos Locais/farmacologia , Animais , Capsaicina/administração & dosagem , Gatos , Feminino , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Masculino , Estimulação Física , Células do Corno Posterior/efeitos dos fármacos , Fármacos do Sistema Sensorial/administração & dosagem , Fármacos do Sistema Sensorial/toxicidadeRESUMO
Selenium is an essential trace element in human health. However, it has been considered a widespread selenium deficiency worldwide, although the recommended daily intake is very low (55 µg per day). Strategies have been implemented to comply with the recommended doses, for example, through bioavailable selenium such as selenoamino acids. Thus, this research aimed to elaborate on a beer-type fermented beverage produced with previously selenized Saccharomyces boulardii. For this, the yeast was selenized by adding a minimum inhibitory concentration of Na2SeO3 (74 ppm) to YPD media. Subsequently, barley must fermentations were carried out for 120 h. Kinetic parameters of the fermentation and physicochemical parameters and selenium content of the beverage were measured. The yeast accumulated up to 25.12 mg/g of dry cell. Furthermore, selenization affected the fermentation rate, but the beverage's physicochemical parameters were not different from those of the control. Due to the final concentration of selenium in the beverage (0.378 mg/kg), it is considered a process that confers advantages for the safe intake of selenium with bioavailable potential. In conclusion, fermented beverages enriched with organic selenium could be produced through cell selenization to produce functional beverages and food.
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Decision support systems (DSS) have generated high expectations as a tool to support activated sludge operation because of their ability to represent heuristic reasoning and to handle large amounts of qualitative, uncertain and low-accuracy data. Previous applications have been satisfactory to control simple problems, when static reasoning and literature-based solutions were enough. However to face complex operational problems with biological origin and slow dynamics (e.g. solids separation problems), it is necessary to use dynamic reasoning and apply long-term control strategies, monitoring the evolution of the process and adjusting the action plan according to the feed back of the process. This paper presents a dynamic reasoning DSS to face solids separation problems in the activated sludge system. The DSS is capable of identifying the complex problem affecting the process, determining if the current situation is new or a continuation from the previous one, assessing what is the specific cause of the situation, and recommending a long-term control strategy, which is daily adjusted according to the evolution of the process.
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Técnicas de Apoio para a Decisão , Eliminação de Resíduos Líquidos , Inteligência ArtificialRESUMO
The p53 tumor suppressor protein functions to monitor the integrity of the genome. If a damage is detected, p53 binds tightly to specific sequence elements in the DNA and induces the transactivation of genes involved in various growth regulatory processes such as cell cycle progression, DNA repair and apoptosis. A p53-binding site was recently identified in the promoter region of the metastatic suppressor KAI1 gene, suggesting that this gene was a direct transcriptional target of p53. To test the relevance of this hypothesis, we studied the endogenous KAI1 expression in a series of human cell lines with varying p53 status in response to genotoxic treatment as well as in different cellular models exhibiting an inducible p53 activity. Overall, our data indicate that KAI1 expression is not significantly modulated by p53. This observation provides a direct evidence that the presence of a p53-binding site in regulatory domains is not a sufficient criteria to define a p53-transcriptional target gene.
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Antígenos CD , Dano ao DNA , Glicoproteínas de Membrana , Metástase Neoplásica/genética , Proteínas Proto-Oncogênicas , Proteína Supressora de Tumor p53/metabolismo , Humanos , Proteína Kangai-1 , Células Tumorais CultivadasRESUMO
Poly(ADP-ribosyl)ation is an immediate cellular response to DNA damage generated either exogenously or endogenously. This post-translational modification is catalyzed by poly(ADP-ribose) polymerase (PARP, PARP-1, EC 2.4.2.30). It is proposed that this protein plays a multifunctional role in many cellular processes, including DNA repair, recombination, cell proliferation and death, as well as genomic stability. Chemical inhibitors of the enzyme, dominant negative or null mutations of PARP-1 cause a high degree of genomic instability in cells. Inhibition of PARP activity by chemical inhibitors renders mice or rats susceptible to carcinogenic agents in various tumor models, indicating a role for PARP-1 in suppressing tumorigenesis. Despite the above observations, PARP-1 knockout mice are generally not prone to the development of tumors. An enhanced tumor development was observed, however, when the PARP-1 null mutation was introduced into severely compromised immune-deficient mice (a mutation in DNA-dependent protein kinase) or mice lacking other DNA repair or chromosomal guardian molecules, such as p53 or Ku80. These studies indicate that PARP-1 functions as a cofactor to suppress tumorigenesis via its role in stabilization of the genome, and/or by interacting with other DNA strand break-sensing molecules. Studies using PARP-1 mutants and chemical inhibitors have started to shed light on the role of this protein and of the specific protein post-translational modification in the control of genomic stability and hence its involvement in cancer.
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Reparo do DNA , Neoplasias/etiologia , Poli(ADP-Ribose) Polimerases/fisiologia , Animais , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Genômica , Humanos , Neoplasias/genética , Inibidores de Poli(ADP-Ribose) Polimerases , Poli(ADP-Ribose) Polimerases/química , Recombinação GenéticaRESUMO
BACKGROUND: Human organs for transplant from a deceased donor are presently distributed in Spain by means of manual handling and telephone or fax transmission of data. This procedure is conducted organ by organ with the information transmitted sequentially. This process has several inherent drawbacks, the main one being the long length of time to allocate organs on many occasions. A difficulty of this type could be solved by means of an electronic system of data management and transmission through the Internet. CARREL is a platform that could provide an alternative organ distribution procedure. The main objective of CARREL was to increase the efficiency, safety, rapidity, and quality of organ distribution for transplantation, thereby helping the allocation process. MATERIALS AND METHODS: CARREL is a database system, accessible through the Internet, to which any medical center authorized to perform organ transplants in Spain may subscribe. CARREL allows information share between centers, including administrative, anthropometric, immunological, analytical, and clinical data, as well as parameters concerning donor maintenance. CONCLUSIONS: CARREL is an online system that can reduce organ distribution time, directly store complete information concerning the donor, and also share data between centers. It facilitates communication between transplant coordinators at different centers, thereby improving and hastening candidate selection.
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Internet , Transplante de Órgãos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/organização & administração , Bases de Dados Factuais , Humanos , Sistemas On-Line , Transplante de Órgãos/normasRESUMO
BACKGROUND: Until recently, all cornea information at our tissue bank was managed manually, no specific database or computer tool had been implemented to provide electronic versions of documents and medical reports. The main objective of the BanTeC project was therefore to create a computerized system to integrate and classify all the information and documents used in the center in order to facilitate management of retrieved, transplanted corneal tissues. MATERIALS AND METHODS: We used the Windows platform to develop the project. Microsoft Access and Microsoft Jet Engine were used at the database level and Data Access Objects was the chosen data access technology. CONCLUSIONS: In short, the BanTeC software seeks to computerize the tissue bank. All the initial stages of the development have now been completed, from specification of needs, program design and implementation of the software components, to the total integration of the final result in the real production environment. BanTeC will allow the generation of statistical reports for analysis to improve our performance.
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Transplante de Córnea/instrumentação , Software , Transplante de Córnea/métodos , Humanos , Reprodutibilidade dos Testes , EspanhaRESUMO
The use of multi-agent systems (MAS) in health-care domains is increasing. Such agent-mediated medical systems can manage complex tasks and have the potential to adapt gracefully to unexpected events. However, in these kinds of systems the issues of privacy, security and trust are particularly sensitive in relation to matters such as agents' access to patient records, what is acceptable behaviour for an agent in a particular role and the development of trust both between (heterogeneous) agents and between users and agents. To address these issues we propose a formal normative framework, deriving from and developing the notion of an electronic institution. Such institutions provide a framework to define and police norms that guide, control and regulate the behaviour of the heterogeneous agents that participate in the institution. These norms define the acceptable actions that each agent may perform depending on the role or roles it is playing, and clearly specifies the data it may access and/or modify in playing those roles. In this paper, we present the formalization of Carrel, a virtual organization for the procurement of organs and tissues for transplantation purposes, as an electronic institution using the ISLANDER institution specification language as formalizing languages. We demonstrate aspects of the formalization of such an institution, example fragments in the language used for the textual specification, and how such formalization can be used as a blueprint in the implementation of the final agent architecture, through techniques such as skeleton generation.
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Inteligência Artificial , Confidencialidade , Software , Bancos de Tecidos , Obtenção de Tecidos e Órgãos , Tomada de Decisões Assistida por Computador , Humanos , NegociaçãoRESUMO
A knowledge-based approach for the supervision of the deflocculation problem in activated sludge processes was considered and successfully applied to a full-scale plant. To do that, a methodology that integrates on-line, off-line and heuristic information has been proposed. This methodology consists of three steps: (i). development of a decision tree (which involves knowledge acquisition and representation); (ii). implementation into a rule-based system; and (iii). validation. The set of symptoms most useful in diagnosing the deflocculation problem has been identified, the different branches to diagnose pin-point floc and dispersed growth have been built (using generic and specific knowledge), and all this knowledge has been codified into an object-oriented shell. The results obtained in the application of this knowledge-based approach to the Granollers WWTP (which treats about 130000 inhabitants-equivalents) showed that the system was able to identify correctly the problem with reasonable accuracy. Our positive experience building this system suggests that this approach is a practical and valuable element to include in an intelligent supervisory system combining numerical and reasoning techniques.
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Inteligência Artificial , Árvores de Decisões , Modelos Teóricos , Eliminação de Resíduos Líquidos , Automação , Floculação , EsgotosRESUMO
Integrated operation of Wastewater Treatment Plants is still far from being solved. A reasonable proposal should link advanced and robust control algorithms to some knowledge-based techniques, allocating the detailed engineering to numerical computations, while delegating the logical analysis and reasoning to supervisory intelligent systems. This paper describes the development and implementation of a knowledge-based Hybrid Supervisory System to support the operation of a real Wastewater Treatment Plant. The system integrates different reasoning modules, overcoming the limitations in the use of each single technique, while providing an agent based architecture with additional modularity and independence. It is structured into three separated levels: data gathering, diagnosis, and decision support. The different tasks of the system are performed in a seven-step cycle: data gathering and update, diagnosis, supervision, prediction, communication, actuation, and evaluation phase. In spite of certain reservations of the scientific community about the use of these techniques, the system is successfully performing real-time support to the operation of the Granollers facility since September 1999. Results of the first four-month validation period are shown and discussed. An example of the system behavior is also shown in the paper. The conclusions indicate the key steps which are necessary to transfer the system to another facility.
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Esgotos/química , Purificação da Água/instrumentação , Purificação da Água/métodos , Algoritmos , Automação , Simulação por Computador , Controle de Qualidade , Poluentes da Água/análiseRESUMO
The development of a case-based reasoning system for the supervision of an activated sludge process is presented here. The methodology proposed permits the use of past experiences to solve new problems that arise in the process. These experiences are classified as cases or situations. The adaptation of cases and the generation of new cases are used to tune the response of the system and to learn from the new information generated by the process. The case and the case library definition, the initial seed, the search and retrieval process, the adaptation, the action, the evaluation and the learning steps are presented and outlined. The process studied is the wastewater treatment plant of Girona, Spain. Two examples of the response of the system to two different operational situations are presented. The paper also outlines the integration of different fields in a multidisciplinary approach as the most optimal solution to ensure the successful control and supervision of complex processes like the activated sludge process. With this aim the integration of an array of specific supervisory intelligent systems (for the logical analysis and reasoning) and numerical computations for detailed engineering is suggested.
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Engenharia Sanitária/métodos , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Bactérias , Tomada de Decisões , Humanos , ConhecimentoRESUMO
Recent studies have demonstrated a relationship between the expression of stem cell-associated genes and relapses in glioblastoma (GBM), suggesting a key role for tumor stem cells in this process. Although there is increasing interest in this field, glioma stem cells (GSCs) are still poorly characterized, their 'stemness' state and factors maintaining these properties remain largely unknown. We performed an expression profiling analysis of pluripotency in gliomaspheres derived from 11 patients. Comparative analysis between GSCs and H1 and H9 human embryonic stem cells as well as H9-derived neural stem cells indicates major variations in gene expression of pluripotency factors Nanog and OCT4, but a stable pattern for SOX2 suggesting its important function in maintaining pluripotency in GSCs. Our results also showed that all GSC lines have the capacity to commit to neural differentiation and express mesenchymal or endothelial differentiation markers. In addition, hierarchical clustering analysis revealed two groups of GSCs reflecting their heterogeneity and identified COL1A1 and IFITM1 as the most discriminating genes. Similar patterns have been observed in tumors from which gliomaspheres have been established. To determine whether this heterogeneity could be clinically relevant, the expression of both genes was further analyzed in an independent cohort of 30 patients with GBM and revealed strong correlation with overall survival. In vitro silencing of COL1A1 and IFTM1 confirmed the effect of these mesenchymal-associated genes on cell invasion and gliomasphere initiation. Our results indicate that COL1A1 and IFITM1 genes could be considered for use in stratifying patients with GBM into subgroups for risk of recurrence at diagnosis, as well as for prognostic and therapeutic evolution.
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Proteínas de Transporte/genética , Glioma/genética , Proteínas de Membrana/genética , Proteínas de Fusão Oncogênica/genética , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Sequência de Bases , Proteínas de Transporte/metabolismo , Feminino , Rearranjo Gênico , Glioma/metabolismo , Proteínas da Matriz do Complexo de Golgi , Humanos , Masculino , Proteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Dados de Sequência Molecular , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Adulto JovemRESUMO
In Europe senior citizens are a fast growing part of population, increasing proportion of disabled persons and that of persons with reduced quality of life. The concept of disability itself is not always precise and quantifiable. To improve agreement on it, the World Health Organization (WHO) developed the clinical test WHO Disability Assessment Schedule, (WHO-DASII) that includes physical, mental, and social well-being, as a generic measure of functioning. From the medical point of view, the purpose of this work is to extract knowledge about performance of the WHO-DASII using a sample of patients from an italian hospital.This Knowledge Discovery problem has been faced by using clustering based on rules, an hybrid AI and Statistics technique introduced by Gibert (1994), which combines some Inductive Learning (from AI) with clustering (from Statistics) to extract knowledge from certain complex domains in form of tipical profiles. In this paper, the results of applying this technique to the WHO-DASII results is presented together with a comparison of other more classical analysis approaches.
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Pessoas com Deficiência , Qualidade de Vida , Análise por Conglomerados , Europa (Continente) , Humanos , Organização Mundial da SaúdeRESUMO
Exposure of mammalian cells to genotoxic agents evokes a complex cellular response. An ordered series of molecular events is necessary to sense DNA damage, transduce the signal, and ultimately delay the cell cycle or trigger apoptosis. Recently, we have shown that BTG2/TIS21 gene expression was induced in response to DNA damage through a p53-dependent pathway. This gene belongs to a newly identified family of structurally related genes whose other known human members are BTG1, BTG3, and Tob. To define the respective involvement of these four related genes in the cellular response to DNA damage, we studied their expression in human cell lines after a variety of genotoxic treatments. Our results demonstrated that were BTG1, BTG2/TIS21, and Tob genes the DNA damage--inducible genes. However, BTG2/TIS21 appeared to be the only p53-transcriptional target gene. We speculate that BTG proteins may play a coordinate role in a general transduction pathway that is induced in response to DNA damage. It has been previously described that recombinant BTG1 and BTG2/TIS21 can physically interact with PRMT1, an arginine methyl transferase, suggesting that BTG1 and BTG2/TIS21 induction may lead to posttranslational modifications of cellular proteins. In support of this hypothesis, we showed that the endogenous induction of BTG1 and BTG2 after genotoxic treatment was correlated with a modulation of protein methylation.