Key Points• Myeloma cells produce ammonium in the presence of glutamine, showing high glutaminase and low glutamine synthetase expression.• Myeloma cells show high expression of glutamine transporters and inhibition of ASCT2 transporter hinders myeloma growth.The importance of glutamine (Gln) metabolism in multiple myeloma (MM) cells and its potential role as a therapeutic target are still unknown, although it has been reported that human myeloma cell lines (HMCLs) are highly sensitive to Gln depletion. In this study, we found that both HMCLs and primary bone marrow (BM) CD138 1 cells produced large amounts of ammonium in the presence of Gln. MM patients have lower BM plasma Gln with higher ammonium and glutamate than patients with indolent monoclonal gammopathies. Interestingly, HMCLs expressed glutaminase (GLS1) and were sensitive to its inhibition, whereas they exhibited negligible expression of glutamine synthetase (GS). High GLS1 and low GS expression were also observed in primary CD138 1 cells. Gln-free incubation or treatment with the glutaminolytic enzyme L-asparaginase depleted the cell contents of Gln, glutamate, and the anaplerotic substrate 2-oxoglutarate, inhibiting MM cell growth. Consistent with the dependence of MM cells on extracellular Gln, a gene expression profile analysis, on both proprietary and published datasets, showed an increased expression of the Gln transporters SNAT1, ASCT2, and LAT1 by CD138 1 cells across the progression of monoclonal gammopathies. Among these transporters, only ASCT2 inhibition in HMCLs caused a marked decrease in Gln uptake and a significant fall in cell growth. Consistently, stable ASCT2 downregulation by a lentiviral approach inhibited HMCL growth in vitro and in a murine model. In conclusion, MM cells strictly depend on extracellular Gln and show features of Gln addiction. Therefore, the inhibition of Gln uptake is a new attractive therapeutic strategy for MM. (Blood. 2016;128(5):667-679)
Mitral valve replacement is a suitable option for patients with chronic ischemic mitral regurgitation and impaired left ventricular function. It provides better results in terms of freedom from reoperation with comparable valve-related complication rates.
BackgroundAn important number of patients with idiopathic dilated cardiomyopathy have dramatically improved left ventricular function with optimal treatment; however, little is known about the evolution and long‐term outcome of this subgroup, which shows apparent healing. This study assesses whether real healing actually exists in dilated cardiomyopathy .Methods and ResultsPersistent apparent healing was evaluated among 408 patients with dilated cardiomyopathy receiving tailored medical treatment and followed over the very long‐term. Persistent apparent healing was defined as left ventricular ejection fraction ≥50% and indexed left ventricular end‐diastolic diameter ≤33 mm/m2 at both mid‐term (19±4 months) and long‐term (103±9 months) follow‐up. At mid‐term, 63 of 408 patients (15%) were apparently healed; 38 (60%; 9% of the whole population) showed persistent apparent healing at long‐term evaluation. No predictors of persistent apparent healing were found. Patients with persistent apparent healing showed better heart transplant–free survival at very long‐term follow‐up (95% versus 71%; P=0.014) compared with nonpersistently normalized patients. Nevertheless, in the very long term, 37% of this subgroup experienced deterioration of left ventricular systolic function, and 5% died or had heart transplantation.ConclusionsPersistent long‐term apparent healing was evident in a remarkable proportion of dilated cardiomyopathy patients receiving optimal medical treatment and was associated with stable normalization of main clinical and laboratory features. This condition can be characterized by a decline of left ventricular function over the very long term, highlighting the relevance of serial and individualized follow‐up in all patients with dilated cardiomyopathy, especially considering the absence of predictors for long‐term apparent healing.
Due to the increase in average life expectancy and the higher incidence of cardiovascular disease with advancing age, more elderly patients present for cardiac surgery nowadays. Advances in pre- and postoperative care have led to the possibility that an increasing number of elderly patients can be operated on safely and with a satisfactory outcome. Currently, coronary artery bypass surgery, aortic and mitral valve surgery, and major surgery of the aorta are performed in elderly patients. The data available show that most cardiac surgical procedures can be performed in elderly patients with a satisfactory outcome. Nevertheless, the risk for these patients is only acceptable in the absence of comorbidities. In particular, renal dysfunction, cerebrovascular disease, and poor clinical state are associated with a worse outcome in elderly patients. Careful patient selection, flawless surgery, meticulous hemostasis, perfect anesthesia, and adequate myocardial protection are basic requirements for the success of cardiac surgery in elderly patients. The care of elderly cardiac surgical patients can be improved only through the strict collaboration of geriatricians, anesthesiologists, cardiologists, and cardiac surgeons, in order to obtain a tailored treatment for each individual patient.
Linear cryoablation with lesions connecting the four pulmonary veins and the mitral annulus is effective in restoration and maintenance of SR in patients with heart valve disease and chronic AF. Limited left atrial cryoablation may represent a valid alternative to the maze procedure, reducing myocardial ischemic time and risk of bleeding.
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