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1.
Rev. clín. esp. (Ed. impr.) ; 215(1): 18-24, ene.-feb. 2015. tab
Artigo em Espanhol | IBECS | ID: ibc-132108

RESUMO

Objetivo. Las gammapatías biclonales se caracterizan por una proliferación clonal de cálulas plasmáticas, o sus progenitores linfoides B, con producción de dos inmunoglobulinas anormales (proteínas M o paraproteínas). No conocemos estudios que hayan analizado esta patología en España. Hemos estudiado las enfermedades subyacentes, características de las paraproteínas y evolución de una serie de pacientes con gammapatía biclonal. Material y métodos. Se revisaron las gammapatías clonales del Servicio de Inmunología del Hospital Puerta de Hierro de Madrid, entre los años 1970 y 2011, seleccionando aquellos pacientes con gammapatía biclonal en una determinación. Se recogieron datos epidemiológicos, enfermedad de base, patologías asociadas, terapias recibidas, paraproteína y cuantificación de inmunoglobulinas. Resultados. De los 1.626 casos de gammapatías clonales, 47 eran gammapatía biclonal (2,89%). La mediana de seguimiento fue de 2 años. La principal entidad asociada fue la gammapatía biclonal de significado indeterminado. La composición de paraproteínas más frecuente fue IgG-IgG. En el 81% de los pacientes con una segunda determinación de paraproteína, había desaparecido al menos un componente M. Un tercio de los pacientes no había recibido tratamiento. Conclusiones. Las gammapatías biclonales se asocian fundamentalmente a gammapatía biclonal de significado indeterminado. Ninguna gammapatía biclonal de significado indeterminado evolucionó a patología maligna. En un elevado porcentaje desapareció al menos uno de los dos componentes clonales, a veces de forma espontánea (AU)


Objectives. Biclonal gammopathies are characterized by the clonal proliferation of plasma cells or their B-lymphoid progenitors and are associated with the production of abnormal immunoglobulins (M proteins or paraproteins). There are no known studies that have analyzed this disease in Spain. We studied the underlying diseases, characteristics of paraproteins and the evolution of a series of patients with biclonal gammopathy. Material and methods. We reviewed clonal gammopathies at the Department of Immunology of Hospital Puerta de Hierro in Madrid, between 1970 and 2011, selecting those patients with biclonal gammopathy in one reading. We collected data on the patient's epidemiology, underlying disease, associated diseases, therapies and paraprotein and immunoglobulin levels. Results. Of the 1626 cases of clonal gammapathies, 47 were biclonal gammopathy (2.89%). The median follow-up was 2 years. The main associated condition was biclonal gammopathies of undetermined significance (BGUS). The most common paraprotein combination was IgG-IgG. Upon conducting a second paraprotein reading, 81% of the patients had lost at least 1 monoclonal component. A third of the patients had not undergone treatment. Conclusions. Biclonal gammopathy are fundamentally associated with biclonal gammopathies of undetermined significance. No biclonal gammopathies of undetermined significance evolved to a malignant disease. In a high percentage of patients, at least 1 of the 2 clonal components disappeared, sometimes spontaneously (AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Paraproteinemias/diagnóstico , Imunoglobulinas/análise , Imunoglobulinas , Eletroforese em Gel de Ágar/métodos , Eletroforese em Gel de Ágar/tendências , Densitometria/métodos , Paraproteinemias/epidemiologia , Estudos Retrospectivos , Genes de Cadeia Leve de Imunoglobulina/imunologia , Genes de Cadeia Leve de Imunoglobulina/fisiologia
2.
Rev Clin Esp (Barc) ; 215(1): 18-24, 2015.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-25440496

RESUMO

OBJECTIVES: Biclonal gammopathies are characterized by the clonal proliferation of plasma cells or their B-lymphoid progenitors and are associated with the production of abnormal immunoglobulins (M proteins or paraproteins). There are no known studies that have analyzed this disease in Spain. We studied the underlying diseases, characteristics of paraproteins and the evolution of a series of patients with biclonal gammopathy. MATERIAL AND METHODS: We reviewed clonal gammopathies at the Department of Immunology of Hospital Puerta de Hierro in Madrid, between 1970 and 2011, selecting those patients with biclonal gammopathy in one reading. We collected data on the patient's epidemiology, underlying disease, associated diseases, therapies and paraprotein and immunoglobulin levels. RESULTS: Of the 1626 cases of clonal gammapathies, 47 were biclonal gammopathy (2.89%). The median follow-up was 2 years. The main associated condition was biclonal gammopathies of undetermined significance (BGUS). The most common paraprotein combination was IgG-IgG. Upon conducting a second paraprotein reading, 81% of the patients had lost at least 1 monoclonal component. A third of the patients had not undergone treatment. CONCLUSIONS: Biclonal gammopathy are fundamentally associated with biclonal gammopathies of undetermined significance. No biclonal gammopathies of undetermined significance evolved to a malignant disease. In a high percentage of patients, at least 1 of the 2 clonal components disappeared, sometimes spontaneously.

4.
Biotechniques ; 33(3): 680, 682, 684 passim, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12238778

RESUMO

Here we compare human monoclonal antibody (MAb) production from mouse strains that carry disruptions of their endogenous mouse IgH/IgK loci and harbor human IgM + Igkappa(BABkappa) or human IgM + Igkappa + IgA transloci (BABkappa,lambda). We found that whereas both strains proved effective for the isolation of antigen-specific IgM antibodies, many of the IgM MAbs elicited from BABkappa comprise human mu chains that are associated with mouse lambda chains. In contrast, BABkappa,lambda mice gave rise to fully functional, polymeric human IgM antibodies comprising both human IgH and human IgL chains. Therefore, the inclusion of a human Iglambda translocus (in addition to the human IgH + Igkappa transloci) not only diminishes problems of endogenous mouse Iglambda expression but also provides a strain of mice that yields fully human MAbs to a wide range of antigens, as witnessed by the isolation of MAbs to human blood cells, tumor cell lines, and an immunoglobulin idiotype.


Assuntos
Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/genética , Imunoglobulina M/biossíntese , Imunoglobulina M/genética , Cadeias kappa de Imunoglobulina/biossíntese , Cadeias kappa de Imunoglobulina/genética , Animais , Anticorpos Monoclonais/imunologia , Regulação da Expressão Gênica/imunologia , Humanos , Hibridomas/imunologia , Hibridomas/fisiologia , Imunoglobulina M/imunologia , Cadeias kappa de Imunoglobulina/imunologia , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Monócitos/imunologia , Monócitos/fisiologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Especificidade da Espécie , Baço/imunologia
5.
Clin Exp Rheumatol ; 20(2): 225-7, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12051404

RESUMO

Intravenous infusion of gammaglobulins (IVIG) is one of the treatments of choice in patients with type II mixed cryoglobulinemia (MC). We describe the case of a patient with MC who suffered an adverse generalised reaction with severe cutaneous vasculitis accompanied by a sudden increase in cryocrit levels shortly after being treated with IVIG. When the same gammaglobulin preparation was added in vitro to a sample of the patient's serum, a strong increment in cryoglobulin precipitation and depletion of the monoclonal IgM peak resulted. We suggest that this simple method of studying the displacement of the precipitation reaction could help to predict the outcome of treatment and must be performed before starting IVIG in patients with MC.


Assuntos
Crioglobulinemia/terapia , Imunoglobulinas Intravenosas/efeitos adversos , Vasculite Leucocitoclástica Cutânea/etiologia , Adulto , Feminino , Humanos , Imunoglobulinas Intravenosas/uso terapêutico
6.
Cancer Immunol Immunother ; 50(2): 87-92, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11401030

RESUMO

Specific immunological responses to the idiotypic epitopes present in the surface immunoglobulin (Ig) of the clonal tumour population can be induced for active immunotherapy in patients with B-cell non-Hodgkin lymphoma (NHL). The clonality of the tumour cells should have important implications for the success of the implemented therapy. Here we report on the case of a patient enrolled in a protocol of active idiotypic immunotherapy in which previous cytofluorometric analysis showed a major IgM+, kappap+ population in the tumoral cell suspensions. However, sequence analysis of both tumour sample and tumour-derived hybrids revealed the presence of two unrelated clones that used different VH and VK gene segments. It was possible to obtain hybridomas secreting these two different IgM, kappap idiotypic proteins. The patient was immunised with a mixture of these two idiotypic Igs conjugated to keyhole limpet haemocyanin. Anti-idiotypic antibodies directed against both tumour-associated proteins were detected. This is the first case of anti-idiotypic therapy in a patient with a biclonal NHL. Our work calls attention to the question of clonality in the context of idiotypic vaccination in NHL patients.


Assuntos
Vacinas Anticâncer/uso terapêutico , Idiótipos de Imunoglobulinas/imunologia , Imunoterapia Ativa , Linfoma Folicular/terapia , Adulto , Sequência de Bases , Hemocianinas/imunologia , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Cadeias kappa de Imunoglobulina/genética , Masculino , Dados de Sequência Molecular
7.
Rev Neurol ; 32(1): 42-5, 2001.
Artigo em Espanhol | MEDLINE | ID: mdl-11293097

RESUMO

INTRODUCTION: Lamotrigine (LTG) is a new antiepileptic drug that it has proved to be efficacious in treating patients with partial and generalized tonic-clonic seizures in adjunctive and monotherapy. It has similar efficacy in comparison with carbamazepine and phenytoin with a minor number of adverse experiences. PATIENTS AND METHODS: We report the use of LTG in adjunctive therapy in 106 adults patients with refractory epilepsy (efficacy and safety) with partial and generalized seizures, with follow-up to 3.4 years. The LTG mean doses used was 273 mg/day. RESULTS: 66% of patients experienced a > or = 50% reduction in seizure frequency, with 30% in remission. Both partial, secondarily generalized and generalized seizures showed significant reductions with LTG treatment. LTG was well tolerated in our patients. Side effects were minor. No case of rash was seen. CONCLUSION: LTG is a excellent agent for adjunctive therapy in refractory epilepsy.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsias Parciais/tratamento farmacológico , Epilepsia Generalizada/tratamento farmacológico , Triazinas/uso terapêutico , Adolescente , Adulto , Idoso , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/efeitos adversos , Astenia/induzido quimicamente , Criança , Pré-Escolar , Avaliação de Medicamentos , Resistência a Medicamentos , Quimioterapia Combinada , Feminino , Seguimentos , Cefaleia/etiologia , Humanos , Lactente , Lamotrigina , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Triazinas/efeitos adversos , Vômito/etiologia
8.
Rev. neurol. (Ed. impr.) ; 32(1): 42-45, 1 ene., 2001.
Artigo em Es | IBECS | ID: ibc-20709

RESUMO

Introducción. La lamotrigina (LTG) es un nuevo antiepiléptico de probada eficacia como tratamiento coadyuvante y como monoterapia en el control de todo tipo de crisis parciales, y tonicoclónicas generalizadas, con eficacia similar a la carbamacepina y a la fenitoína pero con un número más reducido de efectos adversos. En el presente estudio abierto aportamos nuestra experiencia con el uso de LTG en pacientes con crisis epilépticas resistentes al tratamiento habitual. Pacientes y métodos. Se realizó un estudio de eficacia clínica y aparición de efectos indeseables en 106 pacientes adultos con crisis epilépticas tanto parciales (simples o complejas) con y sin generalización secundaria, como generalizadas, refractarias al tratamiento antiepiléptico, a los que se instauró tratamiento con LTG en dosis medias de 273 mg/día siempre en politerapia. El seguimiento fue de 3,4 años. Resultados. El 66 por ciento de los pacientes presentan una reducción en más del 50 por ciento de las crisis previas tras la introducción del tratamiento, permaneciendo el 30 por ciento libres de crisis durante el período de seguimiento. El tratamiento fue eficaz tanto para crisis parciales como generalizadas, siendo particularmente eficaz en las crisis parciales complejas y en las secundariamente generalizadas. Los efectos secundarios fueron escasos y leves. No se detecto exantema cutáneo. Conclusión. La LTG es un fármaco muy eficaz en las epilepsias de difícil control, con una tolerancia excelente (AU)


Assuntos
Pessoa de Meia-Idade , Criança , Pré-Escolar , Adolescente , Adulto , Idoso , Masculino , Lactente , Feminino , Humanos , Triazinas , Resultado do Tratamento , Astenia , Anticonvulsivantes , Avaliação de Medicamentos , Resistência a Medicamentos , Quimioterapia Combinada , Epilepsias Parciais , Epilepsia Generalizada , Seguimentos , Cefaleia , Vômito
9.
Bone Marrow Transplant ; 25(10): 1105-8, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10828874

RESUMO

A 48-year-old patient with IgA k multiple myeloma received a BMT from his HLA-matched sibling. After transplantation, the disease relapsed. Melphalan therapy followed by reinfusion of haemopoietic blood stem cells collected from the patient led to the improvement of the clinical status, although mixed chimerism and an elevated serum IgA persisted. Successful donor immunisation against an immunogenic preparation of the recipient monoclonal protein was performed before the infusion of donor T lymphocytes (DLI) into the patient. Ten weeks after the lymphocyte infusions, no monoclonal band was evidenced and donor complete chimerism was detected. The patient did not develop GVHD. Once complete remission was achieved, the idiotype vaccine was administered to the patient. Nineteen months after DLI, the patient remains in remission. Bone Marrow Transplantation (2000).


Assuntos
Doadores de Sangue , Imunização , Imunoglobulina A/imunologia , Idiótipos de Imunoglobulinas/imunologia , Cadeias kappa de Imunoglobulina/imunologia , Imunoterapia Adotiva , Transfusão de Linfócitos , Mieloma Múltiplo/terapia , Proteínas do Mieloma/imunologia , Terapia de Salvação , Linfócitos T/transplante , Antineoplásicos Alquilantes/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Medula Óssea , Quimera , Terapia Combinada , Dexametasona/administração & dosagem , Doxorrubicina/administração & dosagem , Sobrevivência de Enxerto , Humanos , Masculino , Melfalan/uso terapêutico , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/imunologia , Indução de Remissão , Vincristina/administração & dosagem
11.
Headache ; 40(1): 45-7, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10759903

RESUMO

OBJECTIVE: The aim of our study was to investigate the possible effect of acenocoumarol, which is indicated for nonneurological disease, on headache. BACKGROUND: It has been suggested that anticoagulation can have beneficial effects in the control of migraine attacks. METHODS: Four hundred randomized patients on oral anticoagulant therapy were asked to complete a questionnaire regarding their headaches. RESULTS: Headache was present before or during oral anticoagulation in 166 (66 migraineurs and 100 nonmigraineurs) of 326 respondents. The major finding was that oral anticoagulation produced improvement in 63% of patients with migraine versus 38% of patients with nonmigranous headache. Improvement was related to the severity of migraine but not to age. CONCLUSIONS: Oral anticoagulant therapy can improve migraine. The way in which anticoagulant therapy acts on migraine is unknown, but potential mechanisms include its effect on platelet aggregability and pharmacological effects such as suppression of enhanced nitric oxide.


Assuntos
Acenocumarol/uso terapêutico , Anticoagulantes/uso terapêutico , Transtornos de Enxaqueca/tratamento farmacológico , Acenocumarol/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/farmacologia , Feminino , Cefaleia/tratamento farmacológico , Cefaleia/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/prevenção & controle , Distribuição Aleatória , Estudos Retrospectivos , Inquéritos e Questionários
12.
APMIS ; 108(11): 764-70, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11211971

RESUMO

In patients with B-cell lymphoma, only in rare cases a secreted paraprotein is found, and in very few of them an associated autoantibody activity has been demonstrated. Here we report the case of a patient with a low-grade B-cell lymphoma with a serum biclonal paraprotein (G,M)lambda and severe erythroblastopenia. Indirect immunofluorescence studies of total serum revealed cytoplasmic (Hep-2 cells) and extracellular matrix (rat tissue sections) staining, suggestive of a new specificity. After gel filtration of serum samples, only the IgM-containing fraction showed the same pattern of staining. Tumor-derived hybridomas expressed an unmutated V3-11 gene identical to that found in tumor samples and secreted an IgM immunoglobulin endowed with the same reactivity, which confirms the tumoral origin of the tissue-reactive protein. The results suggest a link between the autoimmune condition in this patient and the novel specificity displayed by the tumor-derived immunoglobulin.


Assuntos
Anticorpos Antineoplásicos/imunologia , Autoanticorpos/imunologia , Linfoma de Células B/imunologia , Linfoma Folicular/imunologia , Paraproteínas/imunologia , Adulto , Sequência de Aminoácidos , Animais , Anticorpos Antineoplásicos/sangue , Especificidade de Anticorpos , Autoanticorpos/sangue , Sequência de Bases , Linhagem Celular , Técnica Indireta de Fluorescência para Anticorpo , Genes de Imunoglobulinas , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Dados de Sequência Molecular , Ratos , Células Tumorais Cultivadas
13.
Nat Med ; 5(9): 1076-9, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10470089

RESUMO

Malignant transformation of human cells requires the accumulation of multiple genetic alterations, such as the activation of oncogenes and loss of function of tumor suppressor genes or those related to genomic instability. Among the genetic alterations most frequently found in human tumors are chromosomal translocations that may result in the expression of chimeric products with transforming capability or are able to change the expression of oncogenes. We show here that the adenovirus early region 1A (E1A) gene can induce a specific human fusion transcript (EWS-FLI1) that is characteristic of Ewing tumors. This fusion transcript was detected by RT-PCR in normal human fibroblasts and keratinocytes after expression of the adenovirus E1A gene, as well as in human cell lines immortalized by adenoviruses. Cloning and sequencing of the RT-PCR product showed fusion points between EWS and FLI1 cDNA identical to those detected in Ewing tumors. In addition, we detected a chimeric protein by western blot analysis and immunoprecipitation and a t(11,22) by fluorescent in situ hybridization. This association between a single viral gene and a specific human fusion transcript indicates a direct link between viral genes and chromosome translocations, one of the hallmarks of many human tumors.


Assuntos
Proteínas E1A de Adenovirus/metabolismo , Genes Virais/fisiologia , Proteínas de Fusão Oncogênica/genética , Oncogenes/genética , Sarcoma de Ewing/genética , Fatores de Transcrição/genética , Proteínas E1A de Adenovirus/genética , Adenovírus Humanos/genética , Sequência de Bases , Linhagem Celular , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 22/genética , Fibroblastos , Regulação Neoplásica da Expressão Gênica , Genes Virais/genética , Humanos , Hibridização in Situ Fluorescente , Queratinócitos , Dados de Sequência Molecular , Peso Molecular , Mutação , Proteínas de Fusão Oncogênica/biossíntese , Oncogenes/fisiologia , Proteína Proto-Oncogênica c-fli-1 , RNA Mensageiro/análise , RNA Mensageiro/genética , Proteína EWS de Ligação a RNA , Sarcoma de Ewing/metabolismo , Fatores de Transcrição/biossíntese , Translocação Genética/genética
14.
Rev Neurol ; 26(153): 769-71, 1998 May.
Artigo em Espanhol | MEDLINE | ID: mdl-9634665

RESUMO

INTRODUCTION: Neurocutaneous melanosis is an infrequent condition characterized by the presence of numerous gigantic cutaneous naevi and melanocytic infiltration of the central nervous system and/or the leptomeningeal layers. Different clinical features may be seen: endocranial hypertension due to hydrocephalus, cranial nerve paralysis, myelopathy, convulsive seizures, etc. The prognosis is considered to be malignant. Only positive CNS histological findings confirm the diagnosis. CLINICAL CASE: We present the case of a man with cutaneous lesions compatible with the diagnosis of neurocutaneous melanosis since birth, with benign self-limiting epilepsy in early childhood. Cerebral CT and MR scans were normal until the age of 17, when hipper-signal lesions appeared on MR, infiltrating the leptomeninges of the deep temporal pole and anterior aspect of the cerebral peduncles, which suggested the presence of melanocytes in the CNS. CONCLUSIONS: There are cases of neurocutaneous melanosis with a good medium-term prognosis and benign manifestations until infiltration of the CNS occurs. Then they start to show the classical behavior of cases with a malignant prognosis. MR should be included as part of the diagnostic criteria for neurocutaneous melanosis. MR should be done periodically in patients with cutaneous lesions suggestive of this condition.


Assuntos
Encefalopatias/patologia , Melanose/complicações , Melanose/patologia , Nevo/patologia , Neoplasias Cutâneas/patologia , Criança , Humanos , Imageamento por Ressonância Magnética , Masculino
15.
Cephalalgia ; 18(3): 157-8, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9595210

RESUMO

Three new cases compatible with hypnic headache syndrome (HHS) are presented. The patients were 70, 77, and 79 years of age (2F, 1M). They described a history of nocturnal headache ranging from 5 months to 7 years. One patient was afflicted with diffuse pain but the other two had unilateral pain. In one patient headache was clearly related with dreams, but in the other two this point could not be confirmed. Except for headache being unilateral in two cases, the remaining HHS criteria were present. It is noteworthy that pain responded to flunarizine in two patients.


Assuntos
Cefaleia/diagnóstico , Transtornos do Sono-Vigília/diagnóstico , Idoso , Bloqueadores dos Canais de Cálcio/uso terapêutico , Dominância Cerebral , Antagonistas de Dopamina/uso terapêutico , Sonhos , Feminino , Flunarizina/uso terapêutico , Cefaleia/tratamento farmacológico , Cefaleia/etiologia , Humanos , Masculino , Transtornos do Sono-Vigília/tratamento farmacológico , Transtornos do Sono-Vigília/etiologia , Síndrome , Resultado do Tratamento
16.
J Immunother Emphasis Tumor Immunol ; 17(3): 194-8, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7613645

RESUMO

Active immunization with autologous idiotypic immunoglobulin, obtained by somatic fusion techniques, has been shown to be a useful alternative treatment in patients with B-cell lymphoma. Nevertheless, the requirement for biopsy specimens to obtain lymphoma cells could be a limitation to this therapeutic strategy. We address the question of whether peripheral blood samples containing small amounts of tumor cells can be used as appropriate fusion partners to rescue tumor-derived idiotypic proteins. In this report, we show that hybrid cells can be obtained from somatic fusions of K6H6/B5 heterohybridoma with lymphoma cells obtained from both lymph node (LN) and peripheral blood mononuclear cells (PBMC) containing only minor amounts of tumor cells. Some hybrid cells obtained from LN or PBMC fusions present an immunoglobulin (Ig) heavy-chain gene rearrangement identical with that of the original tumor and secrete identical Ig protein containing the expected H and L chains.


Assuntos
Idiótipos de Imunoglobulinas/isolamento & purificação , Leucócitos Mononucleares/imunologia , Linfoma de Células B/imunologia , Feminino , Rearranjo Gênico , Genes de Imunoglobulinas , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Pessoa de Meia-Idade
17.
J Immunol ; 150(1): 8-16, 1993 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-8417133

RESUMO

Precursor of T lymphocytes undergo proliferation and maturation under the influence of the thymic microenvironment. In our study, we have attempted to determine the distribution of human postnatal thymocytes in division according to their stage of differentiation. Our data show that about 11.5% of all thymic cells are in S/G2/M phases, and that a subset of the cortical and precortical subpopulations contains most of the dividing cells. Rate of cell division is maintained at high levels from the prethymocyte precursor along the successive stages of differentiation represented by CD1+CD3-CD4-CD8- and CD1+CD3-CD4+CD8- cells. The percentage of dividing cells is maximal in an intermediate subset of CD1+CD3-CD4+CD8-CD45RO+ cells defined by the distinct expression of class I HLAdim/high molecules, which could contain cells in transit from prethymocytes to double-positive cortical cells. The CD3- fraction of the double-positive cortical cells contains most of the dividing thymocytes, although the rate of division within this subset is much less than that of the precursor CD1+CD3-CD4+CD8- cells. In a linear scheme of differentiation, cell division stops at or near the point of initiation of CD3 expression. These results suggest that in human thymus cell expansion takes place before the initiation of the positive selection process. According to this view the stringency of the selection process would require the previous generation of a large number of precursors to permit the production of sufficient numbers of mature T cells.


Assuntos
Complexo CD3/análise , Ativação Linfocitária , Linfócitos T/fisiologia , Antígenos de Superfície/análise , Separação Celular , Pré-Escolar , DNA/análise , Citometria de Fluxo , Humanos , Lactente , Subpopulações de Linfócitos T/química , Subpopulações de Linfócitos T/imunologia , Linfócitos T/química , Linfócitos T/imunologia
18.
Clin Exp Immunol ; 88(2): 341-4, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1572099

RESUMO

Treatment of unfractionated human thymocytes in culture with the synthetic glucocorticoid dexamethasone induced cell death, as measured by trypan blue exclusion, after several hours of incubation. In purified subsets of human cortical and medullary thymocytes dexamethasone caused cell lysis with similar kinetics in both populations; 50% of thymocytes were killed after 20-24 h of incubation with the steroid. The mechanism of dexamethasone-induced cell death seems to correspond to apoptosis since degradation of DNA into oligonucleosome-sized fragments could be observed in the cultures treated with the steroid. A certain degree of DNA fragmentation and cell death could also be observed in control cultures of thymocytes. In contrast, peripheral T lymphocytes were resistant to the cytolytic effect of glucocorticoid hormone. The killing of human thymocytes by dexamethasone was inhibited by cycloheximide, suggesting that this cell death program requires a fully operating protein synthesis machinery and perhaps the induction of new proteins.


Assuntos
Dexametasona/toxicidade , Linfócitos T/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Células Cultivadas , Pré-Escolar , Cicloeximida/farmacologia , Dano ao DNA , Dexametasona/antagonistas & inibidores , Humanos , Inibidores da Síntese de Proteínas/farmacologia , Timo/citologia
19.
Cell Immunol ; 141(1): 10-20, 1992 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-1532537

RESUMO

The CD45RA and CD45RO isoforms have been reported to define complementary subsets among CD4+ T cells: CD45RA CD4+ T cells are considered "virgin T cells" and CD45RO "primed T cells." We investigated the secretion of lymphokines by human CD4+ CD45RO and CD4+ CD45RA T helper cells after mitogen stimulation. CD45RA and CD45RO CD4+ T cells were isolated by negative immunoselection using magnetic beads. CD45RO cells, but not CD45RA cells, proliferate well in response to pokeweed mitogen (PWM) or insoluble anti-CD3. Both subpopulations produced interleukin (IL)-2, IL-6, and interferon (IFN)-gamma when stimulated with PWM for 1-4 days. Only Day 1 supernatants from CD45RO cells contained moderate amounts of IL-4. After 14 days of continuous culture and stimulation with PWM, the CD45RA subset had lost the expression of CD45RA and gained that of CD45RO. When long-term cultured CD45RA or CD45RO cells were treated with insoluble anti-CD3, they incorporated [3H]thymidine at similar levels, but only CD45RO cells secreted IL-4 and significantly increased their secretion of IFN-gamma. These data indicate that despite phenotype conversion, the two subpopulations maintain functional differences in the secretion of lymphokines, thus suggesting that circulating CD45RA and CD45RO cells may represent different lines of differentiation.


Assuntos
Antígenos CD/imunologia , Antígenos CD4/imunologia , Antígenos de Histocompatibilidade/imunologia , Interleucinas/metabolismo , Subpopulações de Linfócitos T/imunologia , Humanos , Interferon gama/metabolismo , Interleucina-2/metabolismo , Interleucina-4/metabolismo , Interleucina-6/metabolismo , Antígenos Comuns de Leucócito , Ativação Linfocitária/imunologia , Fenótipo , Subpopulações de Linfócitos T/metabolismo
20.
Eur J Immunol ; 21(1): 115-21, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1991483

RESUMO

We have studied the effects of phorbol-dibutyrate (PBu2), a protein kinase C (PKC) activator, on the proliferation of peripheral human T cells and thymocyte subpopulations selected by treatment with monoclonal antibodies and complement: pre-thymocytes (CD1a-CD3-CD4-CD8-), cortical thymocytes (CD3-, class I- antigens) and medullary thymocytes (enriched as CD1a- cells). PBu2 induces a dose-dependent proliferative response in human peripheral blood T cells at concentrations greater than 6 ng/ml, this proliferation being mediated by the autocrine interleukin 2 (IL2)/IL2 receptor (IL2R) pathway. Pre-thymocytes respond to PBu2 in a way similar to T cells, being able to secrete IL2 in significant amounts and express the p55 chain of IL2R. On the other hand, cortical thymocytes are not induced to proliferate after PKC activation and neither expression of the p55 chain of IL2R nor IL2 secretion is observed. Human medullary thymocytes, phenotypically identical to peripheral blood T cells, show no proliferation in response to PBu2 at any concentration tested unless IL2 is supplied to the cultures. The activation of PKC induces the expression of IL2R in these cells, but not IL2 secretion. The implications of PKC activation in thymic maturation, the role of IL2 and the relevance of the differences between medullary thymocytes and peripheral blood T cells are discussed.


Assuntos
Ativação Linfocitária , Proteína Quinase C/metabolismo , Linfócitos T/fisiologia , Diferenciação Celular , Separação Celular , Ativação Enzimática , Humanos , Interleucina-2/fisiologia , Dibutirato de 12,13-Forbol/farmacologia , Receptores de Interleucina-2/fisiologia , Linfócitos T/enzimologia , Timo/citologia
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