RESUMO
The proliferative responsiveness of T cells of aged individuals is known to be depressed in both autologous mixed lymphocyte reaction (AMLR) and in PHA-stimulated cultures. In the present study we confirm previous results and also report decreased IL-2 and normal IFN-gamma production (PHA-induced) in aged subjects as compared to young normals. In addition, similar percentages of T lymphocytes expressing surface IL-2 receptors both in the peripheral blood and after different stimulations, i.e. AMLR and PHA, were detected in young and aged individuals. The addition of exogenous IL-2 induces a sharp increase of spontaneous and AMLR proliferation in young individuals, whereas the increase is only slight in aged subjects. The experiments reported herein suggest that in general the T cell proliferation in AMLR is not completely dependent on the presence of IL-2 in the cultures and that aged subjects are probably defective in the production of other factor(s) presumably involved in AMLR proliferation, since the addition of exogenous IL-2 does not produce T-cell proliferation comparable to normal young subjects. The possible meanings of these experimental evidences in AMLR and in the defective immune responses of aged subjects are discussed.
Assuntos
Interleucina-2/imunologia , Ativação Linfocitária , Linfócitos T/imunologia , Adulto , Idoso , Envelhecimento , Células Cultivadas , Feminino , Humanos , Cinética , Teste de Cultura Mista de Linfócitos , Masculino , Receptores Imunológicos/análise , Receptores de Interleucina-2 , Linfócitos T/citologiaRESUMO
Based on commonalities between peripheral blood "immunocytes" and central nervous system cells (both have receptors for endorphins, enkephalins, dopamine, acetylcholine, etc.) blocking of potassium ion channels in both brain cell synaptosome and suppressor T cells, and common sharing of antigenic determinants on one or another immunocyte and one or another CNS cells, we postulated that peripheral blood immunocytes can be used to study CNS mechanisms. In the present studies we used peripheral blood lymphocytes to study the effects of phencyclidine (PCP) on various receptors. This agent causes a permanent psychosis similar to chronic schizophrenia in a small percent of users. We observed similar effects in binding to sigma receptors, inhibition of binding and reversibility of binding in receptors of both human peripheral blood receptors and the mouse neuroblastoma, a hamster brain cell hybrid clone. The results are complete with the hypothesis that some cases of schizophrenia are immunologically mediated, perhaps due to antibodies to the sigma receptor. Alternatively, immunologic deficiency might hinder elimination of neurotropic viruses which in genetically predisposed individuals bind to and block the sigma receptor. Functional deficiency of the brain cell equivalent of lymphocyte suppressor T cells by one or another immunologic mechanisms or an excess of T helper cells might also cause schizophrenia by causing an excess of normal brain "B-cell equivalent cell" output response to sensory input.
Assuntos
Autoanticorpos/biossíntese , Receptores Opioides/metabolismo , Esquizofrenia/metabolismo , Humanos , Fenciclidina/efeitos adversos , Fenciclidina/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores sigma , Esquizofrenia/imunologia , Esquizofrenia/fisiopatologia , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Transmissão SinápticaRESUMO
3-Ketothiolase deficiency (3KTD) manifests with intermittent acidosis and is due to deficiency of mitochondrial 2-methylacetoacetate thiolase. Only 22 patients have been previously reported. Although its variable clinical presentation is recognized, the associated neurological findings have not been detailed. We report four new patients all with significant neurological symptoms. Three patients were examined with MRI of the brain which showed increased T2 intensity within the posterior lateral part of the putamen bilaterally. In two the MRI was otherwise normal; in one delayed myelination was also seen. These MRI putaminal findings may be typical enough to suggest the diagnosis of 3KTD. Two of the three had abnormal EEGs; one had an abnormal VEP. 3KTD can thus occur as an organic acidemia associated with encephalopathy.
Assuntos
Acetil-CoA C-Aciltransferase/deficiência , Erros Inatos do Metabolismo/enzimologia , Doenças do Sistema Nervoso/enzimologia , Encéfalo/patologia , Carnitina/sangue , Pré-Escolar , Eletroencefalografia , Feminino , Fibroblastos/enzimologia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Espectrometria de Massas , Erros Inatos do Metabolismo/genética , Erros Inatos do Metabolismo/patologia , Mitocôndrias/enzimologia , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/patologia , FenótipoRESUMO
Three children from consanguineous parents began losing the ability to walk in late infancy. Despite chronically progressive weakness leading to wheelchair dependence by adolescence and later loss of motor speech production, intellect remained preserved. Examination revealed upper motor neuron findings of pseudobulbar palsy and spastic quadriplegia, without dementia, cerebellar, extrapyramidal or sensory signs. In addition they exhibited a diffuse conjugate saccadic gaze paresis, especially severe on down-gaze. CT and MRI scans of brain and spinal cord, EEGs, visual and brainstem auditory evoked potentials, CSF examinations, enzyme assays for lysosomal storage diseases, blood amino acids and urine organic acids were all normal. Cortical somatosensory evoked potentials were poorly configured in two of the patients, though they had normal central conduction. EMG showed no signs of denervation. Nerve conduction studies showed normal peripheral motor and sensory conduction velocities. Transcranial magnetic stimulation of the brain elicited no motor-evoked potentials. Despite the lack of neuropathological confirmation, the clinical course and neurophysiologic data strongly support the diagnosis of a familial (autosomal recessive) primary lateral sclerosis (PLS).