RESUMO
As a result of the aging population dementia is a growing challenge, especially in healthcare. Nevertheless, cognitive disorders are often not systematically evaluated, especially during hospital stays for other reasons; however, cognitive impairment is associated with a number of geriatric syndromes, including falls, delirium, dysphagia and lack of adherence to treatment plans. This article considers the current state of diagnosis and treatment of dementia. Non-pharmacological therapeutic approaches as well as current and future pharmacological treatment options are discussed. The drugs of choice for the symptomatic treatment of cognitive deficits in Alzheimer's disease and Parkinson-associated dementia are cholinesterase inhibitors and memantine; there is no specific pharmacological treatment for other types of dementia. Prevention and treatment of cardiovascular risk factors can potentially retard the progression of possibly all forms of dementia.
Assuntos
Inibidores da Colinesterase/uso terapêutico , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/terapia , Memantina/uso terapêutico , Idoso , Doença de Alzheimer , Inibidores da Colinesterase/efeitos adversos , Demência , HumanosRESUMO
Nonsense-mediated decay (NMD) eliminates mRNAs containing premature termination codons and thus helps limit the synthesis of abnormal proteins. New results uncover a broader role of NMD as a pathway that also affects the expression of wild-type genes and alternative-splice products. Because the mechanisms by which NMD operates have received much attention, we discuss here the emerging awareness of the impact of NMD on the manifestation of human genetic diseases. We explore how an understanding of NMD accounts for phenotypic differences in diseases caused by premature termination codons. Specifically, we consider how the protective function of NMD sometimes benefits heterozygous carriers and, in contrast, sometimes contributes to a clinical picture of protein deficiency by inhibiting expression of partially functional proteins. Potential 'NMD therapeutics' will therefore need to strike a balance between the general physiological benefits of NMD and its detrimental effects in cases of specific genetic mutations.
Assuntos
Códon sem Sentido , Doenças Genéticas Inatas/genética , Processamento Alternativo , Regulação da Expressão Gênica , Genes Supressores de Tumor , Doenças Genéticas Inatas/terapia , Humanos , Modelos Genéticos , RNA MensageiroRESUMO
Tracking cognition in patients with multiple sclerosis (MS) is important for detection of disease progression but it is often not performed in routine settings due to time constraints. This exploratory cohort study aims to develop a very brief repeatable tracking tool with comparable test quality criteria to the current gold standard, the Brief International Cognitive Assessment for MS (BICAMS). The study included 88 participants (22 healthy controls, 66 MS patients) who were examined at baseline and at one-year follow-up. As a validity criterion for the six administered cognitive tests, we assessed the difference between MS patients and HC, and the correlation with MS-related disability. Combining the two tests with the highest validity-the Controlled Oral Word Association Test and Symbol Digit Modalities Test-yielded an administration time of 5 min. Comparing this new TRACK-MS test battery with the 15 min BICAMS indicated that TRACK-MS showed larger differences between MS patients and healthy controls, a higher correlation with MS-related disability, smaller practice effects, and a good test-retest reliability. We provide evidence that TRACK-MS, although faster to administer, showed at least comparable quality criteria as the BICAMS. As the study was exploratory, replication of these results is necessary.
RESUMO
In eukaryotes, a surveillance pathway known as nonsense-mediated decay (NMD) regulates the abundance of messenger RNAs containing premature termination codons (PTCs). In mammalian cells, it has been asserted that the NMD-relevant first round of translation is special and involves initiation by a specific protein heterodimer, the nuclear cap-binding complex (CBC). Arguing against a requirement for CBC-mediated translation initiation, we show that ribosomal recruitment by the internal ribosomal entry sequence of the encephalomyocarditis virus triggers NMD of a PTC-containing transcript under conditions in which ribosome entry from the cap is prohibited. These data generalize the previous model and suggest that translation per se, irrespective of how it is initiated, can mediate NMD.