RESUMEN
A series of organometallic Re(I)(L)(CO)3Br complexes with 4'-substituted terpyridine ligands (L) has been synthesised as electrocatalysts for CO2 reduction. The complexes' spectroscopic characterisation and computationally optimised geometry demonstrate a facial geometry around Re(I) with three cis COs and the terpyridine ligand coordinating in a bidentate mode. The effect of substitution on the 4'-position of terpyridine (Re1-5) on CO2 electroreduction was investigated and compared with a known Lehn-type catalyst, Re(I)(bpy)(CO)3Br (Re7). All complexes catalyse CO evolution in homogeneous organic media at moderate overpotentials (0.75-0.95 V) with faradaic yields of 62-98%. The electrochemical catalytic activity was further evaluated in the presence of three Brønsted acids to demonstrate the influence of the pKa of the proton sources. The TDDFT and ultrafast transient absorption spectroscopy (TAS) studies showed combined charge transfer bands of ILCT and MLCT. Amongst the series, the Re-complex containing a ferrocenyl-substituted terpyridine ligand (Re5) shows an additional intra-ligand charge transfer band and was probed using UV-Vis spectroelectrochemistry.
RESUMEN
Pericardial effusion and cardiac tamponade following renal transplantation have been recognized as a potentially serious complications associated with the use of sirolimus for immunosuppression. Our study aims to analyze the development of sirolimus-associated pericardial effusion. Patients who underwent renal transplantation at our institution between 2001 and 2014 were reviewed and the correlation between sirolimus exposure and pericardial effusion was determined. Nineteen out of 792 patients who received a renal transplant over this 14-year period (incidence 2.4%) developed symptomatic pericardial effusion (determined by the need for pericardiocentesis or a pericardial window). All patients had a pre-transplantation cardiac workup, including echocardiogram, which did not reveal the presence of pericardial effusion. Our cohort of patients is mostly male (57.9%) and Caucasian (73.7%), which is consistent with the makeup of transplant recipients at our center. The mean age was 52.42 years at the time of transplantation. The development of symptomatic pericardial effusions occurred at a mean of 5.06 (.5-9.8) years after renal transplant while on sirolimus therapy. Sirolimus levels at diagnosis were 5.19-7.47 ng/mL. No significant pericardial effusion (resulting in tamponade physiology) recurred after therapeutic intervention, including cessation of sirolimus with or without pericardial drainage. This study is the largest single-center report of the possible association between pericardial effusion in renal transplant recipients who received sirolimus. Due to the widespread use of sirolimus in organ transplantation, clinicians must remain vigilant for this potential cardiac complication.
Asunto(s)
Inmunosupresores/efectos adversos , Trasplante de Riñón , Derrame Pericárdico/inducido químicamente , Sirolimus/efectos adversos , Adulto , Estudios de Cohortes , Femenino , Humanos , Terapia de Inmunosupresión/efectos adversos , Incidencia , Masculino , Persona de Mediana Edad , Derrame Pericárdico/epidemiologíaRESUMEN
OBJECTIVES: Prognostic implications of early protocol biopsies have been studied; however, the value of late protocol biopsy in predicting graft outcome has not been well defined. Here, we compared the effects of early and late protocol biopsy histologic findings in stable kidney allografts and aimed to understand the significance of "borderline" rejection on allograft function. MATERIALS AND METHODS: We studied 261 biopsies from 159 renal transplant recipients who were on a steroid-free, calcineurin inhibitor and mycophenolate mofetil regimen and who received transplants between 2004 and 2012 with mean follow-up of 5 years. Early (between 3 and 9 mo) and subsequent late (between 12 and 24 mo) protocol biopsies were performed. Biopsies were classified as normal, interstitial fibrosis and/or tubular atrophy, subclinical acute rejection with interstitial fibrosis and/or tubular atrophy, and borderline rejection with interstitial fibrosis and/or tubular atrophy. A linear mixed-effects model was used to determine the effects of early and late protocol biopsies on estimated glomerular filtration rate changes, with baseline time for estimated glomerular filtration rate fixed at 12 months. RESULTS: The adjusted model showed that estimated glomerular filtration rate at 3 months, donor age, delayed graft function, and early protocol biopsies were associated with baseline estimated glomerular filtration rate at 12 months. Estimated glomerular filtration rate changes over time were associated with findings of interstitial fibrosis and/or tubular atrophy at early biopsy and subclinical acute rejection and borderline rejection at late biopsy. At last follow-up, final estimated glomerular filtration rate was significantly associated with interstitial fibrosis and/or tubular atrophy at early biopsy and with subclinical acute rejection at late biopsy. CONCLUSIONS: Although early protocol biopsy predicted baseline estimated glomerular filtration rate, late biopsy was important for predicting changes in function over time. In addition, a diagnosis of "borderline" rejection on protocol biopsies predicted long-term graft function.