RESUMO
Widespread loss of cerebral connectivity is assumed to underlie the failure of brain mechanisms that support communication and goal-directed behaviour following severe traumatic brain injury. Disorders of consciousness that persist for longer than 12 months after severe traumatic brain injury are generally considered to be immutable; no treatment has been shown to accelerate recovery or improve functional outcome in such cases. Recent studies have shown unexpected preservation of large-scale cerebral networks in patients in the minimally conscious state (MCS), a condition that is characterized by intermittent evidence of awareness of self or the environment. These findings indicate that there might be residual functional capacity in some patients that could be supported by therapeutic interventions. We hypothesize that further recovery in some patients in the MCS is limited by chronic underactivation of potentially recruitable large-scale networks. Here, in a 6-month double-blind alternating crossover study, we show that bilateral deep brain electrical stimulation (DBS) of the central thalamus modulates behavioural responsiveness in a patient who remained in MCS for 6 yr following traumatic brain injury before the intervention. The frequency of specific cognitively mediated behaviours (primary outcome measures) and functional limb control and oral feeding (secondary outcome measures) increased during periods in which DBS was on as compared with periods in which it was off. Logistic regression modelling shows a statistical linkage between the observed functional improvements and recent stimulation history. We interpret the DBS effects as compensating for a loss of arousal regulation that is normally controlled by the frontal lobe in the intact brain. These findings provide evidence that DBS can promote significant late functional recovery from severe traumatic brain injury. Our observations, years after the injury occurred, challenge the existing practice of early treatment discontinuation for patients with only inconsistent interactive behaviours and motivate further research to develop therapeutic interventions.
Assuntos
Lesões Encefálicas/fisiopatologia , Lesões Encefálicas/terapia , Estimulação Encefálica Profunda , Tálamo/fisiologia , Adulto , Nível de Alerta/fisiologia , Conscientização/fisiologia , Lesões Encefálicas/reabilitação , Estimulação Elétrica , Humanos , Modelos Logísticos , Masculino , Fala/fisiologia , Tálamo/fisiopatologia , Fatores de Tempo , Resultado do TratamentoRESUMO
The evaluation and management of prostate cancer (PCa) are based mainly on parameters such as the serum prostate-specific antigen level, clinical stage, and pathologic findings at biopsy or after surgery. The aim of this paper was to review the current roles of conventional imaging and multiparametric magnetic resonance imaging (mpMRI) techniques in the diagnosis of PCa. A non systematic literature search using the Medline and Cochrane Library databases was performed up to January 2012. Bibliographies of retrieved articles and review articles were also examined. Only those articles reporting complete data with clinical relevance for the present review (i.e., diagnosis, staging) were selected. The advent of a high performance (1.5T) and higher fields strength (3T), and thus, higher spatial resolution, increased the potentiality and the diffusion of MR examinations. Intense research has focused on the use of complementary techniques to improve the detection, characterization, and staging of PCa by MRI. This review article is divided into two major parts: the first one considers the technical aspects of mpMRI; the second part is intended to provide the impact of this technique on patients with PCa. Published data indicate an emerging role for MRI (particularly mpMRI combining T2 weighted imaging, diffusion weighted imaging, contrast enhanced MR, and spectroscopy) as the most sensitive and specific tool available for imaging PCa. MpMRI can provide metabolic information, characterize tissue and tumor vascularity, as well as tissue cellularity and correlate with tumor aggressiveness.
Assuntos
Biomarcadores Tumorais/análise , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Humanos , MasculinoAssuntos
Broncodilatadores/uso terapêutico , Pneumopatias Obstrutivas/tratamento farmacológico , Teofilina/análogos & derivados , Adulto , Idoso , Broncodilatadores/administração & dosagem , Ensaios Clínicos como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Teofilina/administração & dosagem , Teofilina/uso terapêuticoRESUMO
Results of a first-stage Sea Urchin Genome Project are summarized here. The species chosen was Strongylocentrotus purpuratus, a research model of major importance in developmental and molecular biology. A virtual map of the genome was constructed by sequencing the ends of 76,020 bacterial artificial chromosome (BAC) recombinants (average length, 125 kb). The BAC-end sequence tag connectors (STCs) occur an average of 10 kb apart, and, together with restriction digest patterns recorded for the same BAC clones, they provide immediate access to contigs of several hundred kilobases surrounding any gene of interest. The STCs survey >5% of the genome and provide the estimate that this genome contains approximately 27,350 protein-coding genes. The frequency distribution and canonical sequences of all middle and highly repetitive sequence families in the genome were obtained from the STCs as well. The 500-kb Hox gene complex of this species is being sequenced in its entirety. In addition, arrayed cDNA libraries of >10(5) clones each were constructed from every major stage of embryogenesis, several individual cell types, and adult tissues and are available to the community. The accumulated STC data and an expanding expressed sequence tag database (at present including >12, 000 sequences) have been reported to GenBank and are accessible on public web sites.