RESUMO
It has been reported that two genes MSX1 and PAX9, which encode transcription factors, are associated with selective tooth agenesis. Expression of these genes specifically marks the regions of the mesenchyme where the tooth buds are formed. A mutation in the MSX1 gene, detected in a single family, resulting in an Arg-->Pro substitution in the homeodomain of the protein product of this gene has previously been associated with the deficiency of second premolars and third molars. However, mutations of the MSX1 gene were excluded in the patients with agenesis of the other type of teeth. In a single family with the lack of first and second molars, a mutation in the PAX9 gene was found. In our group of patients with the deficiency of various teeth, in 20% of the patients and their relatives sequence analysis revealed a C-->T transition in the coding sequence of the PAX9 gene. However, this polymorphism does not alter amino acid sequence of the protein product of this gene.
Assuntos
Proteínas de Ligação a DNA/genética , Doenças Dentárias/genética , Dente/crescimento & desenvolvimento , Fatores de Transcrição/genética , Primers do DNA , Éxons/genética , Humanos , Fator de Transcrição PAX9 , Polimorfismo Genético , Polimorfismo Conformacional de Fita Simples , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
We have studied the effect of RG 12525, an oral leukotriene D4 (LTD4) antagonist, on LTD4-induced bronchoconstriction in eight male subjects with mild asthma (baseline FEV1 greater than 80% predicted) in a double-blind, placebo-controlled fashion. RG 12525 800 mg displaced the dose-response curve for LTD4 to the right. The mean (95% confidence intervals) difference in log PC20FEV1 following RG 12525 and placebo was 2.88 (1.61, 4.17) doubling doses of LTD4 (P less than 0.01), a 7.5 fold difference. We conclude that RG 12525 when administered orally is an effective LTD4 antagonist in subjects with mild asthma.