Ferrocene-containing cationic lipids for the delivery of DNA: oxidation state determines transfection activity.

The ability of two redox-active, ferrocene-containing cationic lipids [11-(ferrocenylundecyl)trimethylammonium bromide (FTMA) and bis(11-ferrocenylundecyl)dimethylammonium bromide (BFDMA)] to transfect mammalian cells was investigated. This study sought to determine the range of conditions over which these lipids were capable of transfecting cells and whether the oxidation state of the ferrocenyl groups in these materials could be used to influence the extent of transfection. Experiments conducted in the COS-7 cell line demonstrated that reduced and oxidized FTMA were substantially cytotoxic and did not transfect cells. Subsequent experiments conducted using BFDMA and reporter plasmids encoding enhanced green fluorescent protein (EGFP) and firefly luciferase demonstrated that BFDMA was able to transfect cells. However, the extent of transfection depended significantly upon both the concentration of BFDMA and the oxidation state of the lipid. Quantitative characterization of cytotoxicity and gene expression demonstrated that a window of concentration existed over which reduced BFDMA was non-cytotoxic and yielded high levels of transfection, but over which electrochemically oxidized BFDMA yielded very low (background) levels of transfection. Characterization of lipoplexes using dynamic light scattering demonstrated that reduced and oxidized BFDMA formed small aggregates (ca. 90 to 250nm) at concentrations of lipid ranging from 2 to 10 microM. Taken together, these results demonstrate that the oxidation state of BFDMA, which can be controlled electrochemically, can be used to control the extent of cell transfection. These results could form the basis of transfection procedures that exploit the redox behavior of ferrocene-containing lipids to achieve active spatial and temporal control over transfection using electrochemical methods.     

Graft-versus-host disease after liver transplantation complicated by systemic aspergillosis with pancarditis.

Graft-versus-host disease after liver transplantation complicated by systemic aspergillosis with pancarditis. Can J Gastroenterol 2000;14(7):637-640. Acute graft-versus-host disease (GVHD) is a common complication after bone marrow transplantation, with characteristic rash and diarrhea being the most common features. After liver transplantation, however, this phenomenon is very rare. Most transplant patients are on a variety of medications, including immunosuppressants; therefore, the differential diagnosis of skin rash or diarrhea is broad. A 37-year-old man who underwent liver transplantation for primary biliary cirrhosis, and developed a rash and watery diarrhea, is presented. Skin and colonic biopsies confirmed acute GVHD. A pulse of intravenous steroids was given. The skin rash improved, but he developed pancytopenia. His course was complicated by central line infection, jugular and subclavian vein thrombosis, pseudomembranous colitis, recurrent bacteremia, cholestasis on total parenteral nutrition and cytomegalovirus infection. After the onset of pleuritic chest pain and clinical sepsis, spiral computed tomography scan of his chest and abdomen revealed septic infarcts in multiple organs. Despite empirical treatment with amphotericin B, he died of multiorgan dysfunction syndrome within 72 h. Autopsy revealed systemic aspergillosis with pancarditis, endocardial vegetations, and septic pulmonary, splenic, hepatic and renal infarcts. The pathogenesis and experience with this rare, but often fatal, complication of liver transplantation are reviewed. In contrast to GVHD after bone marrow transplantation, pancytopenia is common and liver dysfunction is rare. One should have a high level of suspicion in the liver transplant recipient presenting with rash and/or diarrhea.     

Effect of nicotine aerosol on slowly adapting receptors in the airways of the dog

The response of slowly adapting airway stretch receptors to nicotine aerosol was studied in the paralyzed, artificially ventilated, anesthetized dog. Single-unit stretch receptor recordings were made from individual vagus nerve filaments placed on a pair of platinum hook electrodes. Administration of 2% nicotine aerosol for five consecutive breaths caused an increase in both the peak transpulmonary pressure (Ptp) and in the activity of the slowly adapting stretch receptors (SARs). The results suggest that tracheal SARs were more affected than those receptors located distal to the carina. Administration of nicotine aerosols following pretreatment with isoproterenol, a bronchodilator, failed to significantly increase Ptp and, concomitantly, the activity of SARs. Therefore, the stimulatory effect of nicotine on SARs appeared to involve primarily an indirect activation of SARs via nicotine-induced bronchoconstriction. It is suggested that the activation of SARs may be involved in the reported nicotine-dependent cigarette smoke-induced apnea.     

Anti-neutrophil nuclear antibody in ulcerative colitis, Crohn''s disease and primary sclerosing cholangitis.

We have previously described circulating autoantibodies to a portal tract antigen in patients with primary sclerosing cholangitis. In this study the antigen has been shown by double-labelling studies to be specifically located in the nuclei of tissue neutrophils. Using isolated peripheral blood neutrophils and an immunoperoxidase technique, anti-neutrophil nuclear antibody (ANNA) was found in the serum of 84% of patients with primary sclerosing cholangitis (PSC: n = 32) with a median titre of 1/1000 and a peak titre of 1/500,000. ANNA was also detected in 86% of patients with inflammatory bowel disease alone (IBD: n = 76) with a median titre of 1/10 and a peak titre of 1/10,000. In contrast, only 12% of controls had ANNA, and in none was the titre greater than 1/10. In PSC the ANNA titre correlated with the serum aspartate transaminase concentration, suggesting that it is related to disease activity. In IBD the titre of ANNA was significantly higher in patients with recently active disease. There was no significant difference between the titres seen in ulcerative colitis and Crohn's disease. ANNA was not associated with neutropaenia. The results provide further evidence of involvement of autoimmune mechanisms in inflammatory bowel disease and primary sclerosing cholangitis.     

Peripheral aneurysms

Peripheral atherosclerotic aneurysms occur primarily in elderly men. Major complications are arterial thromboembolism with ischemia of the limb and, rarely, rupture of the aneurysm. Vascular reconstruction is associated with a low mortality, and operation is recommended. These aneurysms are often associated with arterial ectasia at other locations. The presence of peripheral atherosclerotic aneurysms always requires a search for other peripheral aneurysms, particularly in the abdominal aorta.