RESUMO
Background: As non-cystic fibrosis bronchiectasis (NCFB) progresses, patients suffer irreversible lung damage and deterioration in lung function. This study explored whether inhalational parameters (peak inspiratory flow [PIF, primary endpoint], inspiratory volume and time [secondary endpoints]) represent barriers to complete dosing in patients with poor lung function who are using Ciprofloxacin dry powder for inhalation (DPI) (a drug-device combination of the T-326 inhaler device and a Ciprofloxacin dry powder formulation). Methods: This open-label, multicenter study generated inspiratory flow rate data from patients with NCFB using the breath-actuated T-326 dry powder inhaler. These rates were compared against reference values to identify whether patients with all degrees of lung function impairment could generate sufficient flow rates to facilitate adequate drug delivery. Patients attended screening and a second visit 1 - 14 days later. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, and inspiratory capacity were measured via spirometry at both visits. Forty-two patients were screened for inclusion; 33 met eligibility criteria and were stratified into one of three groups based on their FEV1% predicted value (group 1: 25% ≤ FEV1% predicted <45%; group 2: 45% ≤ FEV1% predicted <70%; group 3: FEV1% predicted ≥70%). Results: No significant between-group differences occurred in PIF (mean flow rates 68.21, 66.01, and 65.18 L/min in groups 1, 2, and 3, respectively). Individual minimum PIFs of 46.0-49.0 L/min were observed across groups. These results all exceeded the reference value (minimum PIF 45 L/min for Ciprofloxacin DPI) indicating that regardless of the level of airflow obstruction, patients were capable of achieving sufficient PIFs to aerosolize and inhale Ciprofloxacin dry powder with the T-326 inhaler. Conclusions: Our data indicate that T-326 is suitable for use in the drug-device combination Ciprofloxacin DPI to provide targeted pulmonary delivery in patients with NCFB, including those with significantly impaired lung function.
Assuntos
Antibacterianos/administração & dosagem , Bronquiectasia/tratamento farmacológico , Ciprofloxacina/administração & dosagem , Sistemas de Liberação de Medicamentos , Administração por Inalação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Bronquiectasia/fisiopatologia , Ciprofloxacina/farmacologia , Inaladores de Pó Seco , Feminino , Volume Expiratório Forçado , Humanos , Pulmão/metabolismo , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Espirometria , Capacidade Vital , Adulto JovemRESUMO
A member of the R2R3-MYB family of transcription factors was cloned from a cDNA library constructed from RNA isolated from differentiating pine xylem. This MYB, Pinus taeda MYB4 (PtMYB4), is expressed in cells undergoing lignification, as revealed by in situ RT-PCR. Electrophoretic mobility shift assays (EMSAs) showed that recombinant PtMYB4 protein is able to bind to DNA motifs known as AC elements. AC elements are ubiquitous in the promoters of genes encoding lignin biosynthetic enzymes. Transcriptional activation assays using yeast showed that PtMYB4 could activate transcription in an AC-element-dependent fashion. Overexpression of PtMYB4 in transgenic tobacco plants altered the accumulation of transcripts corresponding to genes encoding lignin biosynthetic enzymes. Lignin deposition increased in transgenic tobacco plants that overexpressed PtMYB4, and extended to cell types that do not normally lignify. Taken together, these findings are consistent with the hypothesis that PtMYB4 is sufficient to induce lignification, and that it may play this role during wood formation in pine.
Assuntos
Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas/genética , Genes myb/genética , Pinus/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Sequência de Bases , DNA Complementar/genética , Proteínas de Ligação a DNA/química , Biblioteca Gênica , Lignina/genética , Dados de Sequência Molecular , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , RNA de Plantas/genética , RNA de Plantas/isolamento & purificação , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Nicotiana/metabolismo , Fatores de Transcrição/químicaRESUMO
A cDNA encoding a member of the R2R3-MYB family of transcription factors was cloned from a library constructed from differentiating Pinus taeda (loblolly pine) xylem RNA. This MYB family member, Pinus taeda MYB1 (PtMYB1), was most abundantly expressed in differentiating xylem, as assessed by both ribonuclease protection assays, and by northern blot analysis with poly(A)-enriched RNA. Similar to other plant R2R3-MYB family members, recombinant Pt MYB1 protein was able to bind to AC elements in electrophoretic mobility shift assays (EMSAs). AC elements are DNA motifs rich in adenosine and cytosine that have been implicated in the xylem-localised regulation of genes encoding lignin biosynthetic enzymes. Pt MYB1 not only bound to AC elements, but was also able to induce AC-element-dependent shifts in the electrophoretic mobility of a plant promoter that contains three AC elements, the minimal PHENYLALANINE AMMONIA-LYASE 2 (PAL2) promoter from Phaseolus vulgaris. Transcriptional activation assays conducted using yeast showed that Pt MYB1 also activated transcription, and that it did so in an AC-element-dependent fashion. Pt MYB1 also activated transcription from the minimal PAL2 promoter in plant cells in an AC-element-dependent fashion, as revealed by transient transcriptional activation assays with microprojectile-bombarded tobacco NT-1 cells. Taken together, these finding are consistent with the hypothesis that Pt MYB1 may regulate transcription from cis -acting AC elements in pine xylem.
