RESUMO
BACKGROUND: There is limited published outcome data on the STARFlex device for transcatheter closure of atrial septal defects (ASD). AIM: To contribute to the long term outcomes of ASD device closure with the STARFlex device. METHODS: Results of a prospective FDA approved clinical trial (1999-2001) from a single institution of the STARFlex device for simple ASD was reviewed. The inclusion criteria included age >or=2 years, isolated secundum ASD, evidence of right ventricular volume overload, and maximum stretched diameter <22 mm. A retrospective review of the original study data with most recent follow-up was performed. Clinical success in the trial was defined as complete closure or residual leak Assuntos
Cateterismo Cardíaco/instrumentação
, Comunicação Interatrial/terapia
, Adolescente
, Adulto
, Cateterismo Cardíaco/efeitos adversos
, Procedimentos Cirúrgicos Cardíacos
, Criança
, Pré-Escolar
, Remoção de Dispositivo
, Ecocardiografia Doppler em Cores
, Eletrocardiografia
, Desenho de Equipamento
, Falha de Equipamento
, Feminino
, Seguimentos
, Migração de Corpo Estranho/etiologia
, Migração de Corpo Estranho/cirurgia
, Comunicação Interatrial/diagnóstico por imagem
, Comunicação Interatrial/fisiopatologia
, Hemodinâmica
, Humanos
, Masculino
, Pessoa de Meia-Idade
, Estudos Retrospectivos
, Fatores de Tempo
, Resultado do Tratamento
, Adulto Jovem
RESUMO
The crystal structure of a nucleic acid triplex reveals a helix, designated P-form, that differs from previously reported nucleic acid structures. The triplex consists of one polypurine DNA strand complexed to a polypyrimidine hairpin peptide nucleic acid (PNA) and was successfully designed to promote Watson-Crick and Hoogsteen base pairing. The P-form helix is underwound, with a base tilt similar to B-form DNA. The bases are displaced from the helix axis even more than in A-form DNA. Hydrogen bonds between the DNA backbone and the Hoogsteen PNA backbone explain the observation that polypyrimidine PNA sequences form highly stable 2:1 PNA-DNA complexes. This structure expands the number of known stable helical forms that nucleic acids can adopt.
Assuntos
DNA/química , Conformação de Ácido Nucleico , Oligopeptídeos/química , Sequência de Aminoácidos , Sequência de Bases , Cristalografia por Raios X , Modelos Moleculares , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/química , Conformação ProteicaRESUMO
Peptide nucleic acids (PNAs) are polyamide oligomers that can strand invade duplex DNA, causing displacement of one DNA strand and formation of a D-loop. Binding of either a T10 PNA or a mixed sequence 15-mer PNA to the transcribed strand of a G-free transcription cassette caused 90 to 100 percent site-specific termination of pol II transcription elongation. When a T10 PNA was bound on the nontranscribed strand, site-specific inhibition never exceeded 50 percent. Binding of PNAs to RNA resulted in site-specific termination of both reverse transcription and in vitro translation, precisely at the position of the PNA.RNA heteroduplex. Nuclear microinjection of cells constitutively expressing SV40 large T antigen (T Ag) with either a 15-mer or 20-mer PNA targeted to the T Ag messenger RNA suppressed T Ag expression. This effect was specific in that there was no reduction in beta-galactosidase expression from a coinjected expression vector and no inhibition of T Ag expression after microinjection of a 10-mer PNA.