RESUMEN
Hybridization has an important and often positive role in plant evolution. However, it can also have negative consequences for species. Two closely related species of Ornduffia are endemic to the Porongurup Range in the South West Australian Global Biodiversity Hotspot. The rare Ornduffia calthifolia is found exclusively on the summits, while O. marchantii is more widely dispersed across a greater range of elevation and is not considered threatened. Hybridisation in suitable overlapping habitat has been suspected between them for decades. Here we combine genotyping by sequencing to verify hybridisation genetically, and fine scale (2 m resolution) species distribution modelling (SDM) to test if hybrids occur in suitable intersecting habitat. From a study area of c. 4700 ha, SDM identified c. 275 ha and c. 322 ha of suitable habitat for O. calthifolia and O. marchantii, respectively. We identified range overlap between species of c. 59 ha), which enveloped 32 individuals confirmed to be hybrids. While the hybrids were at the margin of suitable habitat for O. marchantii, their preference for elevated habitat was closer to the more narrowly distributed O. calthifolia. The combination of genetic data and fine scale spatial modelling approaches enabled a better understanding of hybridisation among taxa of conservation significance. However, the level to which hybrid proliferation and competition for habitat presents as a threat to O. calthifolia is currently unknown and requires priority in conservation management given the threats from global warming and disturbance by tourism.
Asunto(s)
Asteraceae/genética , Técnicas de Genotipaje/métodos , Hibridación Genética/genética , Análisis de Secuencia de ADN/métodos , Conservación de los Recursos Naturales , Ecosistema , Modelos Genéticos , Australia OccidentalRESUMEN
Although extracorporeal membrane oxygenation (ECMO) has become standard treatment for neonatal respiratory failure, the results of ECMO in adults have been less encouraging. With technical improvements in membrane oxygenators and revised ECMO protocols, there has been renewed interest in ECMO for adults with severe acute respiratory failure. However, few cases of ECMO as an adjunct to adult lung transplantation have been reported. We present the case of a 20-year-old woman with cystic fibrosis who underwent bilateral single lung transplantation. She had development of severe graft dysfunction in the immediate postoperative period requiring support with ECMO for stabilization.
Asunto(s)
Fibrosis Quística/cirugía , Oxigenación por Membrana Extracorpórea , Rechazo de Injerto/terapia , Trasplante de Pulmón/inmunología , Edema Pulmonar/terapia , Síndrome de Dificultad Respiratoria/terapia , Adulto , Dióxido de Carbono/sangre , Femenino , Estudios de Seguimiento , Rechazo de Injerto/inmunología , Humanos , Oxígeno/sangre , Edema Pulmonar/inmunología , Reoperación , Síndrome de Dificultad Respiratoria/inmunologíaRESUMEN
BACKGROUND: Bio-Medicus centrifugal ventricular support has been used widely for postcardiotomy cardiac failure. The purpose of this study was to review a large series of support patients examining complications and outcomes. METHODS: One hundred twenty-nine patients undergoing cardiac operations at The Methodist Hospital in Houston, Texas, were placed on Bio-Medicus centrifugal ventricular support for postcardiotomy cardiac failure; 102 were male and 27 were female with a mean age of 61.6 years. These patients were selected for ventricular support based solely on failure to be weaned from cardiopulmonary bypass or progressive postcardiotomy cardiac failure shortly after arrival in the intensive care unit. RESULTS: These patients experienced numerous complications including coagulopathy, renal insufficiency or failure, sepsis, neurologic deficits, ventricular failure, arrhythmias, and death; 56.3% of patients were weaned from mechanical support and 21.0% were discharged alive. Causes of death included ventricular failure (62.4%), arrhythmias (12.9%), triage (6.9%), perioperative myocardial infarction or cardiac arrest (5.0%), coagulopathy (4.0%), sepsis syndrome (4.0%), cardiac graft failure (3.0%), and device related (1.0%). The one device-related death was a venous cannula dislodgment in the intensive care unit with subsequent exsanguination. Device-related complications were seen in only 1.6% of patients. CONCLUSIONS: Bio-Medicus centrifugal ventricular support can be implemented rapidly and relatively easily. There are few device-related complications and the cost is relatively inexpensive compared with other assist systems. This series demonstrates that a substantial number of patients who experience reversible postcardiotomy myocardial injury will benefit from temporary centrifugal ventricular support.
Asunto(s)
Gasto Cardíaco Bajo/terapia , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Corazón Auxiliar , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Gasto Cardíaco Bajo/etiología , Procedimientos Quirúrgicos Cardíacos/mortalidad , Puente Cardiopulmonar , Causas de Muerte , Femenino , Corazón Auxiliar/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Complicaciones PosoperatoriasRESUMEN
One hundred and seventy-two patients at The Methodist Hospital in Houston, Texas, were placed on BioMedicus centrifugal ventricular support. One hundred thirty-nine patients were male and 33 were female with a mean age of 59.7 years. Reasons for support were postcardiotomy cardiac failure (129 patients), cardiac allograft failure (17 patients), bridge to transplantation (10 patients), resuscitation (7 patients), postpercutaneous transluminal coronary angioplasty emergent (2 patients), and other (7 patients). Support was by left ventricular assist device in 108 patients, right ventricular assist device in 20 patients, and biventricular assist device in 44 patients. Eighty-four patients (48.8%) were weaned from the ventricular assist device, and 88 patients (51.2%) were not weaned. Thirty-four patients (20.0%) were discharged from the hospital. Complications included coagulopathy, renal insufficiency/failure, respiratory insufficiency/failure, neurological deficits, sepsis, arrhythmias, and device-related complications. Overall causes of death were ventricular failure (55.1%), triage (13.0%), arrhythmias (9.4%), graft failure (5.9%), coagulopathy (4.3%), sepsis syndrome (2.9%), device-related (0.7%), and other (0.7%). BioMedicus centrifugal ventricular support can be implemented rapidly and easily. Device-related complications are few (1.2%), and it is relatively inexpensive when compared with other ventricular assist systems. This series demonstrates that a substantial number of patients may benefit from temporary centrifugal ventricular support.
Asunto(s)
Presión Sanguínea/fisiología , Corazón Auxiliar , Función Ventricular Izquierda/fisiología , Función Ventricular Derecha/fisiología , Adulto , Centrifugación , Estudios de Cohortes , Femenino , Humanos , Complicaciones Intraoperatorias/mortalidad , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/mortalidadRESUMEN
Speciation calculations for aluminum, in water samples taken from a drainage basin containing acid mine waters, demonstrate a distinct transition from conservative behavior for pH below 4.6 to nonconservative behavior for pH above 4.9. This transition corresponds to the pK for the first hydrolysis constant of the aqueous aluminum ion and appears to be a consistent phenomenon independent of field location, ionic strength, and sulfate concentration. Nonconservative behavior is closely correlated with the equilibrium solubility of a microcrystalline gibbsite or amorphous aluminum hydroxide.