RESUMEN
Noradrenergic transmission has been implicated in the affective component of relapse to tobacco smoking. Evidence in human and laboratory animals showed that smoking or nicotine administration may cause changes of the noradrenergic system resulting in hyperactivity in this system after cessation. It has been hypothesised that the anti-adrenergic beta-blocker propranolol may decrease affective activation and arousal observed during drug withdrawal or cue-induced relapse. The aim of the present work was to test the effects of propranolol pre-treatment in a rat model of nicotine cue-induced relapse to nicotine seeking. We also tested the effects of propranolol on food cue-induced reinstatement of food seeking in rats trained on food self-administration. Propranolol transiently inhibited nicotine cue-induced reinstatement. The inhibitory effect of propranolol reached a peak after 30 min from the beginning of the reinstatement session and then it declined until it was completely absent at the end of the 3-h session. This inhibitory effect of propranolol was not observed when the drug was tested versus reinstatement with food cues. The present study suggests a weak effect of propranolol to counteract nicotine cue-induced reinstatement of nicotine seeking. Therefore, these findings do not support a potential use of propranolol for prevention of smoking relapse.
Asunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Conducta Adictiva/prevención & control , Nicotina/efectos adversos , Agonistas Nicotínicos/uso terapéutico , Propranolol/uso terapéutico , Prevención del Hábito de Fumar , Animales , Modelos Animales de Enfermedad , Extinción Psicológica/efectos de los fármacos , Conducta Alimentaria/efectos de los fármacos , Masculino , Nicotina/farmacología , Agonistas Nicotínicos/farmacología , Ratas , Ratas Sprague-Dawley , Recompensa , Prevención Secundaria , Autoadministración , Fumar/tratamiento farmacológicoRESUMEN
Despite technological advances in dialysis treatment, survival, morbidity and the quality of life in hemodialysis (HD) patients are affected by long-term complications, often related to the treatment itself. Among these complications, moderate protein and caloric malnutrition are present in approximately 30% of dialysis patients and are viewed as major contributors to increased mortality. In malnutrition pathogenesis, great importance is given to protein catabolism and to the loss of somatic protein and amino acids during dialysis. On the contrary, toxin clearance is believed to influence, positively, both protein anabolism and dietary protein intake. In hemodiafiltration (HDF), the clearance process is potentiated by three mechanisms (diffusion, convection and adsorption) and this could have a favorable effect on malnutrition. In addition, the reinfusion of regenerated ultrafiltrate (UF) would avoid the loss of large amounts of useful solutes as occurs with standard HD. In fact, all amino acids are present in the UF, which is not important in standard HD, but could be a problem in hemodiafiltration reinfusion (HFR). We treated 16 patients with HFR during the previous 3 months (the study will last for 12 months). Patients had been previously treated with bicarbonate dialysis for at least 6 months. The clinical tolerance of HFR was excellent and the technique appeared to be quite simple. The preliminary biochemical results demonstrated the stabilization of some parameters (such as urea and uric acid) with an adequate clearance of small molecules, while variables related to nutritional status (body weight, serum albumin and serum transferrin) did not change substantially. Surprisingly, the loss of both branched chain amino acids (BCAA) and essential amino acids (EAA) seemed slightly lower in HFR compared with standard HD. However, the reduced loss of amino acids (AA) observed with HFR should take into account other factors, such as absorption on adsorbent material and the basal plasma AA concentrations. Therefore, although each patient is in control of himself, it is difficult to draw any definite conclusions after only 3 months. However, it is evident that the loss of AA in HFR is quite modest and is not increased by the fact that it is a hemofiltration technique with all the consequent positive effects.
Asunto(s)
Hemodiafiltración/métodos , Soluciones para Hemodiálisis/administración & dosificación , Uremia/terapia , Aminoácidos/sangre , Estudios Cruzados , Humanos , Uremia/sangreRESUMEN
In the present study, the authors show that 1, 25 (OH)2 D3 given to hemodialyzed patients taking Al (OH)3, increased their plasma concentrations of Al. Two mechanism can explain this increase: increased intestinal absorption or decreased tissue storage of Al.
Asunto(s)
Aluminio/farmacología , Calcitriol/farmacología , Diálisis Renal , Uremia/sangre , Adolescente , Adulto , Anciano , Hidróxido de Aluminio/farmacocinética , Hidróxido de Aluminio/uso terapéutico , Calcitriol/uso terapéutico , Enfermedad Crónica , Deferoxamina , Interacciones Farmacológicas , Femenino , Humanos , Hiperparatiroidismo Secundario/tratamiento farmacológico , Hiperparatiroidismo Secundario/etiología , Absorción Intestinal/efectos de los fármacos , Masculino , Persona de Mediana Edad , Distribución Tisular , Uremia/complicaciones , Uremia/terapiaRESUMEN
Although the role of prolactin in the initiation and promotion of mammary carcinoma has been proved in animal experiments, a similar effect of hormone in the development of human mammary tumor has not been clearly demonstrated. If hyperprolactinemia is a significant factor in the initiation and promotion of human breast carcinoma, the incidence of mammary carcinoma in patients with hyperprolactinemia, with or without prolactinomas, might be higher than in control populations, but this relationship has never been documented. We present this case to stimulate awareness of the possibility so the condition will be investigated further.