RESUMEN
Telomerase is involved in the elongation of telomeres. It remains active in very few types of cell in mature organisms. One such cell type is the lymphocytes. In this study, we investigated the activity and expression of telomerase in lymphocytes from renal failure patients and compared it to that for normal controls. Inflammation status was determined at the same time. The enzyme activity was measured using PCR-ELISA with peripheral blood mononuclear cells (PBMCs) from three groups: 53 healthy individuals, 50 patients with chronic kidney disease (CKD) and 50 dialysis patients. In the same cell populations, the expression of the reverse transcriptase of the human telomerase gene (hTERT) was measured via real-time PCR. The inflammationstatus of these individuals was determined by calculating the interleukin 6 (IL-6), IL-10, C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-a) serum concentrations via ELISA. The lowest levels of telomerase activity were detected in CKD, and this group had the highest IL-6 and CRP values and the lowest hTERT expression. The dialysis group showed significant differences in comparison to the normal subjects and to the CKD patients. Further studies are warranted in order to explore the way inflammation influences telomerase activity and hTERT expression.
Asunto(s)
Inflamación , Leucocitos Mononucleares/enzimología , Insuficiencia Renal/enzimología , Telomerasa/metabolismo , Transcripción Genética , Adulto , Anciano , Pruebas de Enzimas , Femenino , Humanos , Leucocitos Mononucleares/inmunología , Masculino , Persona de Mediana Edad , Insuficiencia Renal/inmunología , Telomerasa/genéticaRESUMEN
INTRODUCTION: Malignant peripheral nerve sheath tumors are rare soft tissue sarcomas. They are considered to carry a poor prognosis with current therapeutic approaches. Successful treatment depends on a multimodal approach. CASE PRESENTATION: The authors report two cases with malignant peripheral nerve sheath tumors arising from pre-existing neurofibromas in the grounds of neurofibromatis-type I. Complete surgical removal of all lesions is considered before and after induction chemotherapy. Correlation of the response to chemotherapy in the context of the immuno-histopathological features of the tumors is also discussed with reference to the existing literature. CONCLUSION: A need for a multidisciplinary approach with chemotherapy, surgery and radiotherapy is anticipated in the management of malignant peripheral nerve sheath tumors as described in these two reported cases. It is felt that further research on the molecular aspects of malignant peripheral nerve sheath tumors and neurofibromatis-type I will optimize treatment strategies in the future.
Asunto(s)
Índice de Masa Corporal , Enfermedades Renales/epidemiología , Obesidad/epidemiología , Enfermedades Cardiovasculares/epidemiología , Enfermedad Crónica , Humanos , Enfermedades Renales/mortalidad , Enfermedades Renales/fisiopatología , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: Telomerase preserves telomeres' function and structure preventing cellular senescence. Its activity is reduced in peripheral blood mononuclear cells (PBMC) of haemodialysis (HD) patients. The purpose of this study is to investigate the potential correlation between increased oxidative stress/inflammation and telomerase activity in PBMC of HD patients. METHODS: Telomerase activity was measured by PCR-ELISA in PBMC isolated from a group of 42 HD patients and 39 subjects with estimated glomerular filtration rate >or=80 mL/min (control group). Serum oxidized low-density lipoprotein (ox-LDL), tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) were also measured in both groups by ELISA. RESULTS: Ox-LDL was negatively correlated to percentage telomerase activity in PBMC (r = -0.506, P = 0.000 in the whole group of 81 HD and normal subjects and r = -0.559, P < 0.001 in HD patients). TNF was also inversely associated with percentage telomerase activity in the whole group studied (r = -0.492, P = 0.000) while IL-10 was not. In stepwise multiple linear regression, taking into consideration the most important characteristics of the HD patients and control group, the only significant predictors for percentage telomerase activity in PBMC were ox-LDL and TNF (beta = -0.421, t = -4.083, P = 0.000 and beta = -0.381, t = -3.691, P = 0.000, respectively) while examining separately HD patients, the predictors for the same parameter were ox-LDL and HD duration (beta = -0.671, t = -4.709, P = 0.000 and beta = -0.349, t = -2.447, P = 0.023, respectively). CONCLUSION: Ox-LDL serum level is inversely correlated to telomerase activity in PBMC of HD patients. Our study proposes a new consequence of increased oxidative stress in HD patients: the premature cellular senescence potentially related to atherosclerosis through LDL oxidation.