Function of human intrinsic cardiac neurons in situ.

We sought to determine the behavior of intrinsic cardiac neurons in human subjects undergoing cardiac surgery and to correlate their activity with hemodynamics status. A lead II electrocardiogram, pulmonary artery pressure, and systemic arterial pressure were recorded along with extracellular activity generated by right atrial neurons in 10 patients undergoing coronary artery bypass surgery. Identified neurons generated spontaneously activity that was, for the most part, unrelated to the cardiac cycle. Most neurons were activated by gentle mechanical distortion of ventricular epicardial loci. The activity generated by neurons in each patient increased when arterial pressure increased and decreased when arterial pressure fell. Intrinsic cardiac neurons continued to generate activity during cardioplegia and cardiopulmonary bypass, but at reduced levels. Normal neuronal activity was restored postbypass. It is concluded that human intrinsic cardiac neurons generate spontaneous activity and that many receive inputs from ventricular mechanosensory neurites. The latter may account for the fact that their behavior depends, in part, on cardiac dynamics. They are also sensitive to intravenously administered pharmacological agents. These data also indicate that cardiopulmonary bypass and cardioplegia do not induce residual depression of their function.

Traumatic coronary artery fistula management.

Traumatic coronary artery-cameral fistulas (TCAF) are uncommon sequelae of trauma that require early surgical intervention to prevent complications. The etiology of traumatic coronary artery-cameral fistulas may be classified as accidental or iatrogenic and have distinctly different courses depending on the etiology. The two operations described for definitive surgical closure of a traumatic coronary-cameral fistula are external ligation/obliteration of the fistula (with or without bypass grafting to the coronary artery distal to the fistula) and direct repair of the fistula from within the recipient chamber. The technique of fistula closure from within the recipient chamber is associated with a reduced incidence of fistula recurrence. A case report and a collective literature review are presented.

Improved survival of biolistically transfected mouse islet allografts expressing CTLA4-Ig or soluble Fas ligand.

BACKGROUND: Pancreatic islet transplantation is limited because of immune rejection of the transplanted tissue. Long-term survival of allogeneic pancreatic islet grafts in the absence of systemic immunosuppressive agents should be possible by transfecting the islets directly with DNA encoding immunoregulatory molecules. Localized production of these molecules should affect only the immune cells that come into the vicinity of the foreign tissue. We investigated whether local expression of human CTLA4-Ig or soluble human Fas ligand from biolistically transfected mouse islets would have a protective effect on allograft survival. METHODS: Isolated CBA (H2k) islets were biolistically transfected using the gene gun. The experimental groups were naked gold particles (n=6), empty vector DNA (n=5), DNA encoding human CTLA4-Ig (n=8), or soluble human Fas ligand (n=5). Secretion of the transfected gene product was confirmed by screening islet culture supernatants for protein production using a sandwich ELISA. The blasted islets were transplanted under the kidney capsule of alloxan-diabetic BALB/c (H2d) recipients. RESULTS: Control grafts survived for 23 days, on average. CTLA4-Ig-transfected islets showed a bimodal distribution: 50% of cases survived > or = 46 days and 50% were similar to the controls. In the soluble human Fas ligand group, 80% of grafts survived > or = 50 days. There was no correlation between graft survival times and pretransplant levels of protein production. CONCLUSION: Our results indicate that local production of human CTLA4-Ig or soluble human Fas ligand by biolistically transfected islets can promote allograft survival. This approach should be valuable as a potential immunoprotective therapeutic strategy in tissue transplantation.

Churg-Strauss syndrome leading to small bowel infarction: an unusual case of abdominal pain in a young patient.

A 33-year-old man with a history of severe asthma presented to the emergency department with a week-long history of severe unrelenting abdominal pain, nausea and decreased appetite. He was admitted to hospital, and routine gastrointestinal investigations were performed, which did not elucidate the cause of his abdominal pain. Exploratory laparotomy demonstrated patchy infarction of the entire small bowel, characteristic of Churg-Strauss syndrome. The patient subsequently underwent 12 separate laparotomies to salvage surviving small bowel. The patient is maintained on total parenteral nutrition.