RESUMO
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.
Assuntos
Citoesqueleto de Actina/fisiologia , Endotoxemia/fisiopatologia , Coração/fisiopatologia , Contração Miocárdica , Miocárdio/metabolismo , Troponina I/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Cálcio/metabolismo , Citosol/metabolismo , Endotoxemia/metabolismo , Coração/efeitos dos fármacos , Coração/fisiologia , Ventrículos do Coração , Homeostase , Concentração de Íons de Hidrogênio , Isoproterenol/farmacologia , Lipopolissacarídeos/toxicidade , Contração Miocárdica/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Fosforilação , Ratos , ômega-N-Metilarginina/farmacologiaRESUMO
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.
Assuntos
Anfetamina , Estimulantes do Sistema Nervoso Central , Hemorragia Cerebral/induzido quimicamente , Transtornos Relacionados ao Uso de Substâncias/complicações , Adulto , Hemorragia Cerebral/diagnóstico , Feminino , HumanosRESUMO
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.
Assuntos
Angioplastia Coronária com Balão/efeitos adversos , Cardiomiopatias/etiologia , Vasos Coronários/patologia , Fístula/etiologia , Anastomose Cirúrgica , Angina Instável/cirurgia , Angioplastia Coronária com Balão/instrumentação , Angioplastia Coronária com Balão/métodos , Cardiomiopatias/terapia , Ponte de Artéria Coronária , Fístula/terapia , Oclusão de Enxerto Vascular/terapia , Ventrículos do Coração/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/cirurgia , Veias/transplanteRESUMO
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.
Assuntos
Hemorragia Gastrointestinal/etiologia , Pancreatite/complicações , Doença Crônica , Varizes Esofágicas e Gástricas/diagnóstico , Hemorragia Gastrointestinal/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Recidiva , Artéria Esplênica/diagnóstico por imagemRESUMO
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.