RESUMEN
We wished to determine whether the glucocorticoid hormone dexamethasone (dex), a potent modular of both pituitary-adrenal and immunologic activity, altered the effect of adrenocorticotropin-related peptides on activated peripheral blood mononuclear cells (PBMCs) and T-cells. PBMCs preactivated with Concanavalin A (Con A) and T-cells preactivated with phorbol 12,13 dibutyrate (PDB) plus phytohemagglutinin (PHA) were exposed to dex, ACTH, and related peptide sequences. Proliferation of cells was measured as was IL-2 in conditioned media. It was found that in the absence of dex only the peptide ACTH(18-39) altered proliferation of PBMCs while there was no effect of peptide on T-cells activated via protein kinase C-mediated pathways. Significant reversal of the inhibitory effect of dex on proliferation of PBMCs exposed to Con A was achieved with addition of ACTH(1-39) and ACTH(11-24), while IL-2 levels were unaffected by the addition of peptide. ACTH(18-39) and ACTH(11-24) enhanced the inhibitory effect of dex on T-cells activated with PDB plus PHA. These findings suggest that the biologic activity of ACTH on immune cells is altered when dexamethasone is present and under certain circumstances ACTH may protect the immunologic response from the inhibitory effects of elevated ambient glucocorticoids.
Asunto(s)
Hormona Adrenocorticotrópica/fisiología , Dexametasona/farmacología , Leucocitos Mononucleares/metabolismo , Hormona Adrenocorticotrópica/sangre , División Celular/efectos de los fármacos , División Celular/fisiología , Humanos , Técnicas In Vitro , Interleucina-2/sangre , Leucocitos Mononucleares/efectos de los fármacos , Masculino , Fragmentos de Péptidos/farmacologíaRESUMEN
Purified, small resting mouse B cells appear to express low levels of transferrin receptor (TfR) as detected by flow cytometry. Moreover, when such cells are stimulated with LPS or F(ab')2 anti-mu, they show increased expression of TfR as early as 4 h after activation when the cells are at the boundary of G0 and G1 phase by cell cycle analysis. Cells treated with anti-mu increased TfR expression gradually, reaching a plateau after 46 h, whereas cells with LPS reached their plateau by 12 h. The kinetics of induction of increased TfR expression was similar for both small and large B cells. Inhibition of protein synthesis with anisomycin or inhibition of transcription with actinomycin-D blocked the increased expression of TfR at 4 h. Northern blot analysis showed a marked increase of TfR mRNA at 2 and 4 h with either anti-mu or LPS which was then followed by an apparent decline at 16 h. These findings together with other recent studies justify reevaluation of the generally accepted models placing TfR induction late in the G1 phase of the lymphocyte activation sequence. They support the concept that in the B lymphocyte the TfR gene is selectively transcribed earlier than previously thought, before the general increase in RNA synthesis.
Asunto(s)
Linfocitos B/metabolismo , Activación de Linfocitos , Receptores de Transferrina/biosíntesis , Animales , Linfocitos B/inmunología , Linfocitos B/fisiología , Femenino , Regulación de la Expresión Génica , Interfase , Cinética , Ratones , Ratones Endogámicos BALB C , ARN/biosíntesis , ARN Mensajero/aislamiento & purificación , Receptores de Transferrina/genéticaRESUMEN
A patient with systemic lupus erythematosus (SLE) and subdural hematoma is described. Pathophysiological concepts are discussed and a link between this lesion and active SLE is suggested. The disastrous consequences of failure to recognize subdural hematoma in this context is emphasized.
Asunto(s)
Hematoma Subdural/etiología , Lupus Eritematoso Sistémico/complicaciones , Adolescente , Femenino , Hematoma Subdural/diagnóstico por imagen , Hematoma Subdural/cirugía , Humanos , Tomografía Computarizada por Rayos XAsunto(s)
Metilprednisolona/uso terapéutico , Polirradiculoneuropatía/tratamiento farmacológico , Adolescente , Adulto , Biopsia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polirradiculoneuropatía/inmunología , Polirradiculoneuropatía/patología , Estudios Prospectivos , Nervio Sural/patologíaRESUMEN
We present 38 acromegalyc patients who were studied by non invasive methods to assess the frequency of cardiovascular complications. Seventy one percent of the cases presented some type of cardiovascular alteration. In 68% we observed left ventricular hypertrophy by echocardiography which was the most sensitive method to detect it. In 71% we obtained abnormal electrocardiograms, mainly because of conduction disturbances, being right bundle branch block the most frequent. Half of the cases had pulmonary fibrosis and chronic bronchitis. Arterial hypertension was present in 32%. Diabetes mellitus in 21%. Only 2 cases had coronary heart disease. In 37% of the patients who underwent hypophisectomy we observed regression up to 90% of the cardiac complications except for left ventricular hypertrophy and pulmonary fibrosis. None of the patients has died.