RESUMO
OBJECTIVE: We aimed to test the hypothesis that slice-by-slice prospective motion correction at 7T using an optical tracking system reduces the rate of false positive activations in an fMRI group study with a paradigm that involves task-correlated motion. MATERIALS AND METHODS: Brain activation during right leg movement was measured using a block design on 15 volunteers, with and without prospective motion correction. Clearly erroneous activations were compared between both cases, at the individual level. Additionally, conventional group analysis was performed. RESULTS: The number of falsely activated voxels with T-values higher than 5 was reduced by 48% using prospective motion correction alone, without additional retrospective realignment. In the group analysis, the statistical power was increased - the peak T-value was 26% greater, and the number of voxels in the cluster representing the right leg was increased by a factor of 9.3. CONCLUSION: Slice-by-slice prospective motion correction in fMRI studies with task-correlated motion can substantially reduce false positive activations and increase statistical power.
Assuntos
Algoritmos , Artefatos , Mapeamento Encefálico/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Movimento/fisiologia , Feminino , Humanos , Perna (Membro)/fisiologia , Masculino , Movimento (Física) , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estatística como Assunto , Análise e Desempenho de Tarefas , Adulto JovemRESUMO
Macrocyclic peptides are highly promising as inhibitors of protein-protein interactions. While many bond-forming reactions can be used to make cyclic peptides, most have limitations that make this chemical space challenging to access. Recently, a variety of cysteine alkylation reactions have been used in rational design and library approaches for cyclic peptide discovery and development. We and others have found that this chemistry is versatile and robust enough to produce a large variety of conformationally constrained cyclic peptides. In this chapter, we describe applications, methods, mechanistic insights, and troubleshooting for dithiol bis-alkylation reactions for the production of cyclic peptides. This method for efficient solution-phase macrocyclization is highly useful for the rapid production and screening of loop-based inhibitors of protein-protein interactions.
Assuntos
Peptídeos Cíclicos/química , Conformação Proteica , Engenharia de Proteínas/métodos , Mapeamento de Interação de Proteínas/métodos , Alquilação , Cisteína/química , Peptídeos Cíclicos/síntese químicaRESUMO
Triple-A syndrome is a very rare pathology in childhood, consisting of achalasia, alacrima and adrenal insufficiency. The order of manifestation of these three main symptoms is variable. Here we present a case of Triple-A syndrome with recurrent vomiting caused by achalasia as first symptom. At the same time, alacrima was diagnosed. Several years later adrenal insufficiency occurred and substitution therapy with hydrocortisone was started. The follow-up of patients with achalasia should pay attention to symptoms of adrenal insufficiency.
Assuntos
Doenças das Glândulas Suprarrenais/complicações , Acalasia Esofágica/complicações , Doenças do Aparelho Lacrimal/complicações , Vômito/etiologia , Criança , Acalasia Esofágica/diagnóstico por imagem , Acalasia Esofágica/cirurgia , Feminino , Humanos , Radiografia , Recidiva , SíndromeRESUMO
In a 4 year old girl the diagnosis osteogenesis imperfecta type I was suspected by following clinical criteria: four fractures after small trauma, intensive blue sclera, anomalies of dental enamel, macrocephalie with frontal bassing. Clinical diagnosis could be verified by moleculargenetic analysis, a newly recognized heterozygous point mutation (Arg420Stop) in the COL1A1-gene was found.