359 research outputs found

    Antiepileptogenic effects of trilostane in the kainic acid model of temporal lobe epilepsy

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    Objective: Epileptogenesis after status epilepticus (SE) has a faster onset in rats treated to reduce brain levels of the anticonvulsant neurosteroid allopregnanolone with the 5α-reductase inhibitor finasteride; however, it still has to be evaluated whether treatments aimed at increasing allopregnanolone levels could result in the opposite effect of delaying epileptogenesis. This possibility could be tested using the peripherally active inhibitor of 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase trilostane, which has been shown repeatedly to increase allopregnanolone levels in the brain. Methods: Trilostane (50 mg/kg) was administered subcutaneously once daily for up to six consecutive days, starting 10 min after intraperitoneal administration of kainic acid (15 mg/kg). Seizures were evaluated by video-electrocorticographic recordings for 70 days maximum, and endogenous neurosteroid levels were assessed by liquid chromatography–electrospray tandem mass spectrometry. Immunohistochemical staining was performed to evaluate the presence of brain lesions. Results: Trilostane did not alter the latency of kainic acid-induced SE onset or its overall duration. When compared to the vehicle-treated group, rats receiving six daily trilostane injections presented a remarkable delay of the first spontaneous electrocorticographic seizure and subsequent tonic–clonic spontaneous recurrent seizures (SRSs). Conversely, rats treated with only the first trilostane injection during SE did not differ from vehicle-treated rats in developing the SRSs. Notably, trilostane did not modify neuronal cell densities or the overall damage in the hippocampus. In comparison to the vehicle group, repeated administration of trilostane significantly decreased the activated microglia morphology in the subiculum. As expected, allopregnanolone and other neurosteroid levels were remarkably increased in the hippocampus and neocortex of rats treated for 6 days with trilostane, but pregnanolone was barely detectable. Neurosteroids returned to basal levels after a week of trilostane washout.. Significance: Overall, these results suggest that trilostane led to a remarkable increase in allopregnanolone brain levels, which was associated with protracted effects on epileptogenesis

    Finite bisimulations for switched linear systems

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    In this paper, we consider the problem of constructing a finite bisimulation quotient for a discrete-time switched linear system in a bounded subset of its state space. Given a set of observations over polytopic subsets of the state space and a switched linear system with stable subsystems, the proposed algorithm generates the bisimulation quotient in a finite number of steps with the aid of sublevel sets of a polyhedral Lyapunov function. Starting from a sublevel set that includes the origin in its interior, the proposed algorithm iteratively constructs the bisimulation quotient for the region bounded by any larger sublevel set. We show how this bisimulation quotient can be used for synthesis of switching laws and verification with respect to specifications given as syntactically co-safe Linear Temporal Logic formulae over the observed polytopic subsets

    Función de la escuela en la génesis de la seriación

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    Facile multi-components one-pot synthesis of dipyrazolo[1,5-a:3',4'-d]pyrimidine as potent bioactive scaffolds

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    An efficient, three-component, catalyst free synthesis of dipyrazolo[1,5-a:3',4'-d]pyramid scaffolds has been carried out using 3-methyl-1H-pyrazol-5(4H)-one (1), 5-amino pyarazole (2a-b) and substituted aromatic aldehydes. The reaction underwent cyclocondensation reaction in reflux condition with moderate to good (62%–90 %) yields. The twenty newly prepared molecules were analyzed by means of 1H & 13C NMR, Mass, and IR spectroscopies and their activities against the bacterial and fungal strains were screened. Some of tested compounds have shown excellent antibacterial activities while another four were found to have good antifungal activity

    The importance of contextual aspects in the care for patients with functional somatic symptoms

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    Functional somatic symptoms refer to physical symptoms that cannot be (bio) medically explained. The pattern or clustering of such symptoms may lead to functional syndromes like chronic fatigue syndrome, fibromyalgia, irritable bowel syndrome, among many others. Since the underlying pathophysiology remains unknown, several explanatory models have been proposed, nearly all including social and psychological parameters. These models have stimulated effectiveness studies of several psychological and psychopharmacological therapies. While the evidence for their effectiveness is steadily growing, effect-sizes are at most moderate and many patients do not benefit. We hypothesize that the context in which interventions for functional somatic symptoms are delivered substantially influences their effectiveness. Although this hypothesis is in line with explanatory models of functional somatic symptoms, to our knowledge, studies primarily focusing on the influence of contextual aspects on treatment outcome are scarce. Contextual research in the field of somatic symptoms has (irrespective whether these symptoms can be medically explained or not), however, just begun and already yielded some valuable results. These findings can be organized according to Duranti's and Goodwin's theoretical approach to context in order to substantiate our hypothesis. Based on this approach, we categorized empirical findings in three contextual aspects, i.e. 1) the setting, 2) the behavioural environment, and 3) the language environment. Collectively, some support is found for the fact that early identification of patients with functional somatic symptoms, starting treatment as soon as possible, having a neat appearance and an organized office interior, a warm and friendly nonverbal approach and a language use without defensiveness are contextual parameters which enhance the assessment by the patient of the physician's competence to help. Nonetheless, in vivo studies addressing the most aspects, i.e. nonverbal behaviour and language, are needed for better understanding of these contextual aspect. Moreover, future research should address to what extent optimizing contextual aspects improve care for functional somatic symptoms

    "One time I fell, but I didn't have to cry." A qualitative study on everyday physical complaints in children

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    OBJECTIVE: Young children experience physical complaints, like abdominal pain or minor injuries from playing, almost every day. These experiences may shape how they deal with health issues later in life. While models exist to explain illness perception in adults, information is lacking on the perspective of young children. This qualitative study aimed to explore important themes in the experience of everyday physical complaints in four- and five-year-old children, using children as informants. STUDY DESIGN: 30 semi-structured interviews were performed in which four- and five-year-old children were questioned about their experiences with everyday physical complaints. The interviews were double coded using Atlas.ti and subsequently qualitative content analysis was used to define themes. RESULTS: All participating children were able to elaborate on their experiences with physical complaints. Three themes emerged from the interviews: causes of complaints, appraisal of complaints, and implications of complaints. In their appraisal of complaints, four- and five-year-old children made a distinction between visible and invisible complaints and real or pretended complaints. CONCLUSION: Four- and five-year-old children can already give details about their experiences with everyday physical complaints. They have developed ideas about the causes and implications of complaints and try to make an appraisal
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