RESUMEN
Patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) treated by continuous positive airway pressure (CPAP) need to use long-term CPAP to prevent cardiovascular disease. The method of survival analysis was used to allow for long-term CPAP use in 72 patients who were prescribed a CPAP. During a mean follow-up of 22+/-15 months, one patient died and 17 patients stopped their treatment, 29% of them in the first 6 months. In compliant patients, the median value of daily CPAP use was 4.5hours. Kaplan Meier analysis showed that 92% of patients were still using CPAP at 6 months, 83% at 12 months and 59.9% at 3 years. Chronic obstructive pulmonary disease was identified as a predictor factor of long-term CPAP use (OR=4.53, p=0.01). CPAP is a well-accepted long-term therapy for OSAHS with 60% of patients continuing to be compliant with treatment at 3 years.
Asunto(s)
Presión de las Vías Aéreas Positiva Contínua/estadística & datos numéricos , Cooperación del Paciente , Apnea Obstructiva del Sueño/terapia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/epidemiologíaRESUMEN
Catecholamine transporters constitute the biological targets for several important drugs, including antidepressants, cocaine, and related compounds. Some information exists about discrete domains of these transporters that are involved in substrate translocation and uptake blockade, but delineation of domains mediating the ionic dependence of the transport remains to be defined. In the present study, human neuronal transporters for dopamine and noradrenaline (hDAT and hNET) and a series of six functional chimeras were transiently expressed in LLC-PK1 cells. Substitution of Cl(-) by isethionate reveals that cassette IV (i.e., the region of the transporter encompassing transmembrane domain 9 through the COOH terminal) plays an important role in the Cl(-)- dependence of the uptake. Substitutions of Na(+) and NaCl by Tris(+) and sucrose, respectively, demonstrate that three different segments scattered across the transporter are involved in the Na(+)- dependence of the transport activity: cassette I (i.e., the region from the amino terminus through the first two transmembrane domains), cassette IV, and junction between transmembrane domains 3 to 5 and 6 to 8. Results of the present work also suggest that the use of Tris(+) as a substitute for Na(+) results in a biased estimate of the Hill number value for hDAT. This study provides useful clues for identifying specific residues involved in the uptake function of the catecholamine transporters.