RESUMEN
The subcellular mechanisms underlying intrinsic myocardial depression during sepsis remain poorly defined, in particular the relative roles of altered intracellular Ca2+ transients versus changes in myofilament properties. We studied contractile function of cardiac myocytes isolated 12 h after induction of endotoxemia (5 mg/kg intravenous E. coli lipopolysaccharide [LPS]) in conscious rats. Cardiomyocytes from LPS-injected rats had depressed twitch shortening compared with control cells (4.10.2% versus 7.80.3%; P2+ transients (peak indo-1 ratio 1.130.02 versus 1.120.02; P = NS). Contractile depression was unaffected by inhibitors of nitric oxide synthase. Steady-state myofilament response to Ca2+, assessed by tetanization of intact cells over a range of [Ca2+], was reduced significantly in the LPS group (P2+ was unaffected by isoproterenol (3 nmol/L) in endotoxemic cells, whereas there was a rightward shift in control cells. A reduction in myofilament response to Ca2+ is the major determinant of intrinsic cardiac depression in systemic endotoxemia. This condition appears to be related to an increase in myocardial troponin I phosphorylation.
Asunto(s)
Citoesqueleto de Actina/fisiología , Endotoxemia/fisiopatología , Corazón/fisiopatología , Contracción Miocárdica , Miocardio/metabolismo , Troponina I/metabolismo , Citoesqueleto de Actina/metabolismo , Animales , Calcio/metabolismo , Citosol/metabolismo , Endotoxemia/metabolismo , Corazón/efectos de los fármacos , Corazón/fisiología , Ventrículos Cardíacos , Homeostasis , Concentración de Iones de Hidrógeno , Isoproterenol/farmacología , Lipopolisacáridos/toxicidad , Contracción Miocárdica/efectos de los fármacos , NG-Nitroarginina Metil Éster/farmacología , Fosforilación , Ratas , omega-N-Metilarginina/farmacologíaRESUMEN
We present the case of a young female who suffered a massive intracerebral bleed following the ingestion of a small quantity of amphetamine (speed). Physicians should be aware that amphetamine abuse can lead to cerebrovascular events in young adults.
Asunto(s)
Anfetamina , Estimulantes del Sistema Nervioso Central , Hemorragia Cerebral/inducido químicamente , Trastornos Relacionados con Sustancias/complicaciones , Adulto , Hemorragia Cerebral/diagnóstico , Femenino , HumanosRESUMEN
A 58-year-old man with previous myocardial infarction and coronary bypass surgery underwent angioplasty to a totally occluded venous graft to the left anterior descending artery (LAD). The procedure resulted in a coronary-ventricular fistula. Prolonged inflation of the balloon in the proximal part of the graft resulted in obliteration of the fistula with little haemodynamic compromise.
Asunto(s)
Angioplastia Coronaria con Balón/efectos adversos , Cardiomiopatías/etiología , Vasos Coronarios/patología , Fístula/etiología , Anastomosis Quirúrgica , Angina Inestable/cirugía , Angioplastia Coronaria con Balón/instrumentación , Angioplastia Coronaria con Balón/métodos , Cardiomiopatías/terapia , Puente de Arteria Coronaria , Fístula/terapia , Oclusión de Injerto Vascular/terapia , Ventrículos Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/cirugía , Venas/trasplanteRESUMEN
A 52 year old man with chronic pancreatitis presented with recurrent upper gastrointestinal bleeding. Gastroscopy was normal, but visceral angiography suggested that there were gastric varices. Despite treatment with propranolol he had further episodes of bleeding and so underwent splenectomy to decompress the gastric varices. When the spleen was removed, however, an inflammatory mass in the head of the pancreas adherent to the posterior gastric wall was noted. Within it the splenic artery was visible and communicated with the gastric lumen through a small opening in the gastric wall. The artery was ligated and the patient has since had no further bleeding. Thus, chronic pancreatitis should be considered as a cause of recurrent upper gastro-intestinal bleeding, especially when gastroscopy is normal.
Asunto(s)
Hemorragia Gastrointestinal/etiología , Pancreatitis/complicaciones , Enfermedad Crónica , Várices Esofágicas y Gástricas/diagnóstico , Hemorragia Gastrointestinal/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Recurrencia , Arteria Esplénica/diagnóstico por imagenRESUMEN
A 46 year old woman presented with the CREST variety of systemic sclerosis and occult gastrointestinal bleeding due to vascular malformations of her stomach. Partial gastrectomy cured her anaemia. In systemic sclerosis, visceral angiography should be performed early when initial investigations have been negative.