RESUMEN
Parameters which distinguish phototaxis from random motility in Chlamydomonas reinhardtii have been defined with quantitative assays. The phototactic responses in photosynthetic, mixotrophic, and heterotrophic cultures were highest during exponential growth and declined rapidly as the cultures entered stationary phase. In contrast, random motility was relatively constant throughout growth. Phototaxis and motility also differ in their sensitivity to azide and antimycin A. Both of these drugs inhibited phototaxis within 5 min, but motility was unaffected for at least 30 min. Phototaxis and motility have different ion requirements. Optimum motility was observed in the presence of either Ca(++) or Mg(++); phototaxis required Ca(++) and either K(+) or NH(4) (+). Photosynthesis is not required for phototaxis, since phototaxis was not inhibited by dichlorophenyldimethyl urea, and a mutant lacking chlorophyll was phototactic.
Asunto(s)
Chlamydomonas/metabolismo , Luz , Antimetabolitos/farmacología , Arginina/metabolismo , Dióxido de Carbono/metabolismo , División Celular , Movimiento Celular/efectos de los fármacos , Chlamydomonas/efectos de los fármacos , Cicloheximida/farmacología , Dinitrofenoles/farmacología , Diurona/farmacología , Matemática , Fotosíntesis , Proteínas de Plantas/biosíntesis , Factores de TiempoRESUMEN
A multidisciplinary approach using a neonatology independent physicians association, affiliated hospitals, a pediatric home care company, and a health maintenance organization was designed to promote earlier safe discharge of infants from intensive care. This pilot project involved 43 infants who received case management and early discharge home with home oxygen, monitoring, intravenous antibiotics, gavage feedings, phototherapy, or nutritional management for poor weight gain. A staff neonatologist remained the primary physician until the patient would have been discharged according to standard criteria. Two patients had unscheduled readmissions and all infants survived. This approach resulted in an estimated savings of 456 hospital days and $329,982; 89% of parents rated the care as good to excellent, and 83% were satisfied with the program and outcome. This study suggests that a prospectively designed program can be designed to promote safe earlier discharge of infants in intensive care.
Asunto(s)
Servicios de Atención a Domicilio Provisto por Hospital , Unidades de Cuidado Intensivo Neonatal , Tiempo de Internación , Alta del Paciente , Manejo de Caso , Femenino , Humanos , Recién Nacido , Masculino , Proyectos PilotoAsunto(s)
Cuidados Críticos , Enfermedades del Recién Nacido/etiología , Evaluación de la Tecnología Biomédica , Infecciones Bacterianas/etiología , Vasos Sanguíneos , Cateterismo/efectos adversos , Nutrición Enteral/instrumentación , Femenino , Humanos , Recién Nacido , Enfermedades del Recién Nacido/terapia , Unidades de Cuidados Intensivos , Intubación/efectos adversos , Intubación Intratraqueal/efectos adversos , Luz/efectos adversos , Salas Cuna en Hospital , Terapia por Inhalación de Oxígeno/efectos adversos , Fototerapia , Embarazo , Tórax , Tromboembolia/etiología , Arterias Umbilicales , Ventiladores Mecánicos/efectos adversosRESUMEN
Phototaxis in Chlamydomonas reinhardi was specifically inhibited by azide. The effect of azide was rapid and reversible, and did not depend upon the intensity of actinic light. Under conditions of completely inhibited phototaxis, azide had no effect on the number of motile cells in the population or on the rate of motility. The effect was not related to changes in oxygen uptake or cellular ATP concentration. Apparently, a cellular component or process specifically involved in phototaxis is inactivated by azide.
Asunto(s)
Adenosina Trifosfato/metabolismo , Azidas/farmacología , Movimiento Celular/efectos de los fármacos , Chlamydomonas/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Chlamydomonas/metabolismo , Depresión Química , LuzRESUMEN
Tidal liquid ventilation (TLV) with perfluorochemical fluid (PFC) has been successfully used experimentally for up to 4 h. However, no studies of prolonged TLV have been reported. We hypothesized that full-term newborn lambs can safely and effectively be liquid-ventilated for up to 24 h. To test this hypothesis, 17 lambs were liquid-ventilated; 7 for 4 h, 5 for 12 h, and 5 for 24 h. Arterial blood samples were obtained for PFC uptake, lipid analysis, and blood gas measurements. Tissues were obtained for histologic and biochemical analysis. Arterial blood gas and mean arterial blood pressure were as follows (mean +/- SEM): pH 7.48 +/- 0.04; PaCO2 30.6 +/- 2.8; PaO2 424 +/- 17; mean arterial pressure 76 +/- 16 mm Hg. PFC blood levels increased rapidly to a mean of 5.2 +/- 3.9 microg/mL. PFC tissue levels increased significantly (p < 0.01) from 260 +/- 45 microg/g at 4 h to 400 +/- 140 microg/g at 12 h. There was no further increase in PFC tissue levels by 24 h (456 +/- 181 microg/g). There was a significant difference in PFC concentration as a function of tissue (p < 0.01). Furthermore, there was a significant correlation (r = 0.88; p < 0.01) between the amount of PFC and lipid in blood and tissue. Microscopic examination of the lungs demonstrated no evidence of barotrauma. These data demonstrate that prolonged TLV can be safe and efficacious for up to 24 h in full-term newborn lambs.