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1.
Rev Clin Esp (Barc) ; 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39216807

RESUMO

INTRODUCTION: DP-TRANSFERS is a translational lifestyle intervention project, which follows a previous protocol described in the DE-PLAN-CAT study. OBJECTIVE: Analyze the feasibility of reproducing the intensive intervention and estimating the effect of translation in real conditions of clinical practice in primary care. METHODOLOGY: Implementation of the face-to-face group intervention adjusted to 2 years. After screening, the intervention consisted of a basic module and a continuity module. Stratifying by clusters (health centers), a representative sample (centers, professionals and participants) was evaluated (FINDRISC > 11 and/or prediabetes) from 2016 to 2020. The effect of the intervention on the incidence of diabetes was analyzed. RESULTS: The intervention, feasible in 95 of 123 centers, involved 343 of 647 professionals. Of 2381 subjects screened, 1713 participated in the basic module, with 1186 participants completing the first year and 776 completing the second. 121 participants (7.06%) were diagnosed with diabetes: 77 (4.49%) during the first year; 44 (2.57%) during the second. The bivariate analysis showed that those subjects in whom diabetes affected differed in: previous glycemic status, A1c, HDL-cholesterol, FINDRISC score and adherence to the Mediterranean diet, and in the differences between the beginning and end of the study of: body weight, BMI and abdominal circumference. CONCLUSIONS: The intensive intervention substantially reduced (23.6%) the incidence of diabetes compared to that previously estimated in standardized intervention. The following acted as protective factors: a better glycemic status, lower baseline risk, elevated HDL-cholesterol, or achieving a reduction in weight or abdominal circumference during the study.

2.
Leuk Res ; 21(2): 93-9, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9112424

RESUMO

Cytokines such as interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-alpha), stem cell factor (SCF), and interleukin-12 (IL-12), among others, are presently known to exert a radioprotective effect on bone marrow (BM) precursor cells. IL-1, TNF-alpha, transforming growth factor-beta (TGF-beta), and macrophage inflammatory protein-1 alpha (MIP-1alpha) exert a chemoprotective effect on BM cells, while a putative role of IL-12 in this effect is still unknown. IL-1, SCF, and IL-12 are known to promote BM precursor cell cycling. Conversely, TNF-alpha, MIP-1alpha, and TGF-beta, the latter a radiosensitizer, induce cycle arrest in these cells. Cycling increases radioprotection, while arrest reduces chemical damage. IL-1 and TNF-alpha are unique in their ability to induce detoxifying mechanisms. The present communication overviews these effects. It also proposes a model, based on the induction of biochemical detoxifying mechanisms, aiming to explain BM cell radio- and chemoprotection by opposite cell cycle-acting cytokines.


Assuntos
Doenças da Medula Óssea/prevenção & controle , Medula Óssea/efeitos dos fármacos , Citocinas/uso terapêutico , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Animais , Medula Óssea/efeitos da radiação , Células da Medula Óssea , Doenças da Medula Óssea/induzido quimicamente , Doenças da Medula Óssea/etiologia , Ciclo Celular/efeitos dos fármacos , Citocinas/fisiologia , Humanos
3.
Bone Marrow Transplant ; 12(6): 551-63, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8136738

RESUMO

Administration of interleukin 1 (IL-1) or tumor necrosis factor-alpha (TNF alpha) protects bone marrow precursor cells (BMPC) from ionizing radiation and antineoplastic drugs. The time of injection is critical: the best protective results being obtained when cytokines are given around 24h prior to the induced injury. Multiple daily cytokine injections that precede irradiation or drug administration are more effective than single ones although single doses are quite effective at increasing survival in mice. Protection is positively correlated with both rapid granulocyte recovery and BMPC survival. Mechanisms involved in BMPC radioprotection include: (1) push to the S/G2 + M or arrest in the G0 phases of the cell cycle by IL-1 or TNF alpha, respectively, and (2) induction of mitochondrial manganous superoxide dismutase synthesis. For BMPC chemoprotection, proposed mechanisms are: (1) increase of aldehyde dehydrogenase synthesis, and (2) modulation of multiple-drug resistant gene expression. Stimulation of glutathione synthesis in BMPC could be operating in both radio- and chemoprotection. These findings point to the relevance of IL-1 or TNF alpha in cancer therapy as a means of reducing BMPC sensitivity to cytoreductive drugs or irradiation (including radioimmunotherapy) as well as in in vitro tumor cell purging with drugs in autologous BMT. Prior administration of these cytokines should be also considered for people in imminent danger of exposure to radiation.


Assuntos
Medula Óssea/efeitos dos fármacos , Medula Óssea/efeitos da radiação , Interleucina-1/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/antagonistas & inibidores , Células da Medula Óssea , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Ensaio de Unidades Formadoras de Colônias , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos da radiação , Humanos , Técnicas In Vitro , Interleucina-1/administração & dosagem , Interleucina-1/efeitos adversos , Neoplasias/terapia , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/farmacologia , Fator de Necrose Tumoral alfa/administração & dosagem , Fator de Necrose Tumoral alfa/efeitos adversos
4.
Clin Exp Rheumatol ; 22(2): 213-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15083889

RESUMO

OBJECTIVE: To evaluate the clinical and immunomodulatory efficacy of seed extracts from sucupira branca (Pterodon pubescens Benth.), a Brazilian anti-inflammatory folk medicine, against collagen II (CII)-induced arthritis (CIA) in mice. METHODS: Mice were divided into 3 groups: 1) normal control mice received a vehicle (ethanol 15% in water); 2) mice with CIA received the vehicle; and 3) mice with CIA received extract from 1 mg sucupira seeds/day. The daily oral treatments started 21 days after the first collagen immunization, ending 4 weeks later. We analyzed the arthritic index, the histopathology of the joints, the serum anti-CII IgG antibody level, and the absolute counts of the CD4+, CD8+, CD4+CD69+ and CD8+CD69+ subsets of inguinal lymph nodes (LN). RESULTS: Sucupira treatment strongly reduced the severity of arthritis (p < 0.001). Vehicle-treated CIA mice exhibited invasive synovial pannus and significant articular leukocyte infiltration, features that were reduced or absent in sucupira-treated mice. Mice with CIA exhibited twice the number of CD4+ and CD8+ LN cells found in control mice. Suctupira-treated mice exhibited these subsets in numbers comparable to the latter. A two-thirds decrease in the level of serum anti-CII IgG antibody and a normalization of the CD4+CD69+ LN cell number in treated mice hallmark a negative regulatory effect of sucupira on B- and CD4 T-cell activation, respectively. The CD8+CD69+ cell number remained roughly the same in the 3 groups. CONCLUSION: The clinical and immunomodulatory effects of sucupira on CIA provides a further experimental basis for the popular use of sucupira in chronic inflammatory diseases.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Artrite Experimental/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Sementes , Adjuvantes Imunológicos/administração & dosagem , Administração Oral , Animais , Anti-Inflamatórios/administração & dosagem , Antígenos CD/metabolismo , Artrite Experimental/sangue , Artrite Experimental/patologia , Contagem de Células , Modelos Animais de Doenças , Articulações/efeitos dos fármacos , Articulações/patologia , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Masculino , Camundongos , Camundongos Endogâmicos DBA , Extratos Vegetais/administração & dosagem , Plantas Medicinais/química , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia , Resultado do Tratamento
5.
J Pharm Pharmacol ; 56(1): 135-41, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14980011

RESUMO

We previously demonstrated that alcoholic extracts from Pterodon pubescens Benth. (Sucupira branca, Leguminosae) seeds exhibit anti-arthritic activity. In the present work we show that the oleaginous extract obtained from P. pubescens seeds (OEP) exhibits acute or topic anti-edematogenic activity when tested in carrageenan-induced paw edema or in croton oil-induced ear edema assays, respectively. Four fractions were obtained from OEP by sequential liquid-liquid extraction. The anti-edematogenic properties were predominant in the hexanic fraction, which was further fractionated by HPLC, yielding three sub-fractions (PF1.1, PF1.2 and PF1.3). PF1.1 and PF1.3 showed potent acute and topic anti-edematogenic activity. The PF1.2 sub-fraction, although not active in the carrageenan assay, exhibited a potent anti-edematogenic activity in the croton oil-induced ear edema. This sub-fraction shows a maximum efficacy similar to indometacin in a lower dose. The PF1.1 sub-fraction presented a complex mixture containing furane diterpene derivatives of vouacapan. PF1.2 consists of a single substance, geranylgeraniol, as determined by GC/MS and NMR, while PF1.3 contains farnesol.


Assuntos
Edema/tratamento farmacológico , Fabaceae , Fitoterapia , Administração Tópica , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Injeções Intraperitoneais , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Sementes
6.
Braz J Med Biol Res ; 22(5): 601-10, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2620170

RESUMO

1. Three assays were used to test nine sugars for inhibition of jacalin activity prepared from Artocarpus integrifolia. Rat spleen proliferation was unsuitable since the measurement of the effects of sugars against jacalin binding was complicated by their simultaneous metabolic effects on the cells. 2. Based partly on a sheep red blood cell hemagglutination assay and mainly on human serum protein precipitation, the following potencies in relation to D(+)-galactose (taken as 1) were obtained: 1-0-methyl-alpha-D-galactopyranoside, 40; methyl-alpha-D-mannopyranoside and D(+)-galactose, 1; 1-0-methyl-alpha-D-glucopyranoside, 0.4; 1-0-methyl-beta-D-galactopyranoside, 0.2; D(+)-mannose, 0.12; beta-D-(-)-fructose, 0.08; alpha-D(+)-glucose and 1-0-methyl-beta-D-glucopyranoside, less than 0.04.


Assuntos
Indutores de Interferon , Lectinas/antagonistas & inibidores , Monossacarídeos/farmacologia , Lectinas de Plantas , Aglutinação , Animais , Precipitação Química , Ativação Linfocitária/efeitos dos fármacos , Ratos , Baço/citologia
7.
Braz J Med Biol Res ; 22(9): 1111-20, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2636007

RESUMO

1. The parameters involved in the choice of an optimal T cell growth activity (TCGAc) induction protocol using rat spleen cells stimulated with jacalin were studied. 2. In the absence of serum, 5 micrograms/ml jacalin was sufficient to obtain maximal TCGAc. Supernatants could be harvested at any time between 24 and 72 h since significant consumption of TCGAc was not observed during this interval. TCGAc recovery was increased in the presence of 5% fetal calf serum, with the optimal jacalin dose being about 25 micrograms/ml. The recommended harvesting time was 24 h to reduce TCGAc loss due to cellular proliferation. 3. Human or rat sera were not suitable since they absorb significant amounts of jacalin, thus shifting the optimal lectin concentration to greater than 800 micrograms/ml. Indomethacin (1 micrograms/ml) had little enhancing effect on TCGAc production by rat cells but rendered conditioned media less inhibitory of cytotoxic T lymphocyte L (CTLL) proliferation. Addition of 50 ng/ml phorbol myristate acetate is not recommended if the supernatants are to be used for T cell line maintenance, since the agent interferes with CTL function, while only doubling TCGAc production. 4. Jacalin-stimulated TCGAc recovery is comparable, in titer, to that obtained with concanavalin A under the best conditions, but the former is less expensive due to the large quantities of lectin recovered from a single jackfruit, besides being less toxic for rat spleen cells.


Assuntos
Indutores de Interferon/farmacologia , Lectinas/farmacologia , Lectinas de Plantas , Baço/citologia , Linfócitos T/citologia , Animais , Divisão Celular/efeitos dos fármacos , Concanavalina A/farmacologia , Feminino , Indometacina/farmacologia , Masculino , Ratos
9.
AMB Rev Assoc Med Bras ; 37(2): 99-106, 1991.
Artigo em Português | MEDLINE | ID: mdl-1719584

RESUMO

The study of the direct involvement of colony stimulating factors, interleukins, and other purified factors in distinct steps of hematopoiesis has been complicated by the in vitro presence of non-hematopoietic cells which can intermediate the effects observed on hematopoietic precursors. The review covers the recent finding that the CD34 antigen is expressed on the membranes of essentially all pluripotent stem cells, but is lacking in the majority of the differentiated blood and stromal bone marrow cells. This finding allowed in vitro experiments with selected CD34+ hematopoietic precursors, and a consequent reevaluation of the participation of different factors in their differentiation. The role of interferons, tumor necrosis factors, and transforming growth factors beta in the negative regulation of hematopoiesis is also analysed.


Assuntos
Citocinas/fisiologia , Hematopoese/fisiologia , Medula Óssea/fisiologia , Fatores Estimuladores de Colônias/fisiologia , Técnicas In Vitro , Interferons/fisiologia , Interleucina-1/fisiologia , Interleucina-4/fisiologia , Interleucinas/fisiologia , Fatores de Crescimento Transformadores/fisiologia , Fator de Necrose Tumoral alfa/fisiologia
10.
Mem Inst Oswaldo Cruz ; 85(2): 153-62, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2087156

RESUMO

Diverse conditions for stimulating human mononuclear cells to release thymocyte costimulatory factors were tested for their contribution to the generation of supernatants containing high titers of these monokines. Activity titers increased with LPS concentration, reaching a plateau between 1 and 10 micrograms/ml. Indomethacin did not modify the monokine release, but the assay for thymocyte costimulatory activity was substantially affected by inhibitory substances produced by the monocytes in the absence of indomethacin. The use of nylon wool columns to trap the cells was shown to be effective in raising cellular densities without decreasing activity titers. As a result, the yield per cell could be maintained even in the absence of serum, an important step toward the goal of purifying bioactive peptides from crude broths.


Assuntos
Linfocinas/metabolismo , Monócitos/metabolismo , Timo/citologia , Animais , Meios de Cultura , Humanos , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Microscopia de Contraste de Fase
11.
J Immunol ; 161(7): 3384-92, 1998 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9759855

RESUMO

We have recently reported that epidermal growth factor (EGF) modulates thymocyte development in fetal thymus organ cultures. Exogenously added EGF arrested thymocyte growth and differentiation, acting at the transition from the CD4-CD8- (double-negative (DN)) to the CD4+CD8+ (double-positive (DP)) phenotype. In this study, we further investigate some molecular aspects of this blockade. This inhibitory effect could be mimicked by tyrphostins, which are selective inhibitors of EGF receptor kinase activity. An attempt to use insulin (INS) as a synergizing effector resulted in partial restoration of lobe cellularity, leading to expansion of the CD44-CD25+ DN subset. However, INS did not overcome the EGF-driven blockade of the thymocyte DN --> DP transition. Analysis of CD45 phosphatase showed that this transition was preceded by a rise in CD45RB isotype expression. At the end of a 7-day culture, the remaining DN cells from both EGF- and EGF+INS-treated fetal thymus organ cultures showed a CD45RB- phenotype and were negative for the EGF-immunoreactive molecule described previously on the fetal thymocyte surface. This finding implies that neither molecule is related to the growth capability of cells at this early developmental stage; it is more likely that the molecules are related to subsequent events in the thymocyte pathway to the DP phenotype. Thus, our data support the concept that EGF receptor-related circuitry may be relevant in thymus ontogeny. Additionally, evidence is provided for the duality between growth and differentiation at this particular early stage of thymocyte development.


Assuntos
Fator de Crescimento Epidérmico/fisiologia , Receptores ErbB/antagonistas & inibidores , Insulina/farmacologia , Isoenzimas/biossíntese , Antígenos Comuns de Leucócito/biossíntese , Subpopulações de Linfócitos T/citologia , Timo/citologia , Timo/embriologia , Tirfostinas , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Divisão Celular/imunologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/imunologia , Receptores ErbB/metabolismo , Feto , Inibidores do Crescimento/farmacologia , Imunofenotipagem , Camundongos , Camundongos Endogâmicos C57BL , Mimetismo Molecular , Nitrilas/farmacologia , Técnicas de Cultura de Órgãos , Quinazolinas/farmacologia , Solubilidade , Subpopulações de Linfócitos T/enzimologia , Timo/enzimologia
12.
Blood ; 93(3): 974-90, 1999 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9920847

RESUMO

A 250-cGy whole-body gamma-radiation dose was used to induce thymus regression in mice, and to study the expression and function of extracellular matrix (ECM) receptors in distinct thymocyte subsets emerging during repopulation of the organ. The onset of regeneration was detected from day 2 to 3 postirradiation (P-Ir), when a remarkable increase in the absolute counts of CD3(-)CD25(hi)CD44(+) and CD3(-)CD25(in/hi)CD44(-) cells occurred. Enhanced expression of L-selectin, alpha4, and alpha5 integrin chains (L-selhi alpha4(hi) alpha5(hi)) was also exhibited by these cells. This pattern of expression was maintained until the CD4(+)CD8(+) (DP) young stage was achieved. Afterward, there was a general downregulation of these ECM receptors in DP as well as in CD4(+) or CD8(+) single positive (SP) thymocytes (L-selin alpha4(in) alpha5(in)). In some recently generated SP cells, alpha4 expression was downregulated before the alpha5 chain, and L-selectin was upregulated in half of more mature cells. The expression of the alpha6 integrin chain was downregulated only in maturing CD4(+) cells. Importantly, the increased expression of L-selectin and alpha4 and alpha5 chains in thymocytes was strongly correlated with their adhesiveness to thymic epithelial cells (TEC) in vitro. Blocking experiments with monoclonal antibody or peptides showed the following: (1) that the LDV rather than the REDV cell attachment motif in the IIIC segment of fibronectin is targeted by the alpha4 integrin during thymocyte/TEC adhesion; (2) that the RGD motif of the 120-kD fragment of fibronectin, a target for alpha5 integrin, has a secondary role in this adhesion; and (3) that the YIGSR cell attachment motif of the beta1 chain of laminin/merosin recognized by a nonintegrin receptor is not used for thymocyte adherence. In conclusion, our results show that an upregulated set of receptors endows CD25(+) precursors and cells up to the young DP stage with a high capability of interacting with thymic ECM components.


Assuntos
Receptores de Fibronectina/biossíntese , Subpopulações de Linfócitos T/fisiologia , Timo/citologia , Regulação para Cima , Animais , Anticorpos Monoclonais/metabolismo , Antígenos CD/biossíntese , Antígenos CD/genética , Adesão Celular , Diferenciação Celular , Células Epiteliais/fisiologia , Matriz Extracelular/metabolismo , Feminino , Síndromes de Imunodeficiência/etiologia , Síndromes de Imunodeficiência/patologia , Integrina alfa4 , Integrina alfa5 , Integrina alfa6 , Selectina L/biossíntese , Selectina L/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oligopeptídeos/metabolismo , Fragmentos de Peptídeos/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Tirosina Quinases/metabolismo , Lesões Experimentais por Radiação/imunologia , Lesões Experimentais por Radiação/patologia , Receptores de Fibronectina/genética , Receptores de Interleucina-2/análise , Regeneração , Timo/embriologia , Timo/fisiologia , Timo/efeitos da radiação
13.
Dev Immunol ; 7(2-4): 279-91, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11097218

RESUMO

Cell adhesion, migration, differentiation and survival or death is amongst a large spectrum of biological responses that can be elicited by ligation of extracellular matrix components to their corresponding receptors. As regards the physiology of the thymus, cell migration is a crucial event in the general process of T cell differentiation. Studies on the intrathymic distribution of ECM components revealed that fibronectin, laminin and type IV collagen, are not restrictedly located at typical basement membrane sites, also forming a thick network in the medullary region of the thymic lobules, whereas very thin ECM fibers are found within the cortex. These ECM components are essentially produced by thymic microenvironmental cells, which also drive thymocyte differentiation. Signals triggered by ECM are conveyed into thymocytes or microenvironmental cells through specific membrane receptors, and most of them belong to the integrin type, such as the VLA-3, VLA-4, VLA-5 and VLA-6. In vitro studies revealed that adhesion of thymocytes to thymic microenvironmental cells is mediated by extracellular matrix. Such an adhesion is preferentially done by immature thymocytes. Importantly, ECM-mediated interactions also govern the entrance and exit of thymocytes in the lymphoepithelial complexes named thymic nurse cells. Lastly, pathological conditions, including infectious and autoimmune diseases, in which changes of ECM ligands and receptors are observed, course with alterations in thymocyte migration and death. In conclusion, the fact that ECM can modulate traffic, differentiation, death and survival of normal thymocytes adds clues for understanding how ECM-mediated interactions behave in the thymus, not only in normal, but also in pathological conditions.


Assuntos
Matriz Extracelular/fisiologia , Linfócitos T/fisiologia , Animais , Adesão Celular , Movimento Celular , Doença de Chagas/imunologia , Humanos , Receptores de Hialuronatos/análise , Laminina/análise , Camundongos , Camundongos Endogâmicos NOD , Proteoglicanas/análise , Timo/citologia
14.
Mem Inst Oswaldo Cruz ; 88(3): 419-25, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8107604

RESUMO

The observation that murine thymocytes increase their proliferation to interleukin 1 (IL-1) in the presence of phytohemagglutinin (PHA) when pre-incubated with interleukin 2 (IL-2) allowed the introduction of a modified assay for the measurement of IL-1 or the search of thymocyte-inducing proliferative activities in biological samples. Pre-incubation of thymocytes for 24 hr with 50 u/ml IL-2, followed by washings, elicited their maximal response to IL-1 in the usual lymphocyte activating factor (LAF) assay. This suggests that sequential events lead to thymocyte activation. The responsiveness is three to five fold greater than, and the total time of assay is the same as that of the LAF assay. Interestingly, pre-incubation with IL-2 renders thymocytes more sensitive than responsive to crude monocyte conditioned media. The use of the MTT colorimetric method for the assessment of thymocyte proliferation, and of the lectin jacalin as a co-mitogen are suggested as alternatives to be used in co-stimulatory assays.


Assuntos
Interleucina-1/fisiologia , Interleucina-2/farmacologia , Fito-Hemaglutininas/farmacologia , Timo/citologia , Animais , Divisão Celular/efeitos dos fármacos , Meios de Cultura , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H
15.
Cell Mol Biol (Noisy-le-grand) ; 47(1): 75-86, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11292262

RESUMO

We used irradiation-induced thymic regression/reconstitution to study phosphotyrosine (PTyr) levels and expression of extracellular matrix receptors in thymocyte subsets by flow cytometry. High PTyr levels (PTyr(hi)) characterized cells from the CD4-CD8-(DN)CD25in/hi to the "early" CD4-CD8+(DP)CD25- stage. Correlation indexes (R) between the percentages of these PTyrhi cells and cells with up-regulated expression of alpha4 integrin (alpha4hi) were strongly positive (R= 0.91, P= 0.002, for DN; R= 0.98, P= 0.0001 for DP). At the "early" DP stage, R between PTyrhi cells and cells with up-regulated expression of alpha5 integrin and L-selectin (alpha5hi and L-sel(hi)) also rendered strongly positive (R>0.95, p<0.0003). "Late" expanding DP cells exhibited intermediate PTyr levels (PTyr(in)), associated with a down-regulation of the adhesion receptors assessed. Triple-labeling suggested that in most early CD3-/lo cells, alpha4hi and alpha5hi, but not L-sel(hi) expression preceded a PTyr(hi) content. CD3in/hi-enriched CD8+ cells were also PTyr(hi), but conversely to the immature ones exhibited a tendency for a negative R between PTyr(hi) and alpha4hi (R = -0.93, P = 0.067, n= 4) or alpha5hi cells (R = -0.77, P = 0.23, n = 4). CD4+ cells were either PTyr(hi) or PTyr(in), exhibiting a tendency for a positive R (R = 0.59, P = 0.124, n= 8) between PTyr(hi) and L-sel(hi) cells only. In conclusion, our results associate an up-regulation of alpha4 and alpha5 chains expression with PTyr(hi) levels and, as elsewhere published, with increased adhesion to fibronectin up to the "early" DP stage, but not afterwards.


Assuntos
Antígenos CD/biossíntese , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD8-Positivos/citologia , Matriz Extracelular/metabolismo , Selectina L/biossíntese , Fosfotirosina/metabolismo , Animais , Apoptose , Diferenciação Celular , Feminino , Integrina alfa4 , Integrina alfaV , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Subpopulações de Linfócitos T/citologia , Irradiação Corporal Total
16.
Dev Immunol ; 5(3): 169-82, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9851357

RESUMO

In the present study, we used the fetal organ culture (FTOC) technique in order to study a putative effect of epidermal growth factor (EGF) on the thymus ontogeny. Functional EGF receptors and more recently the EGF molecule itself, respectively, on the membrane of epithelial components of thymic stroma and on a few thymocytes in adult thymus, had been reported in the literature. We could observe a dose-dependent decrease in cellularity and a progressive retention of thymocytes in the double-negative (CD4-/CD8-) stage of differentiation when exogenous EGF was added. Epidermal growth factor interfered with both fetal stroma growth and thymocyte development at a precise moment, that is, in the passage from double-negative to the double-positive (CD4+/CD8+) stage. After a 7-day FTOC in the presence of EGF, most cells recovered were Thy-1.2+, c-kit+, TSA1-/int, CD3-, and one of CD44high/CD25int, CD44-/CD25int, or CD44/CD25-. Some developed into gammadeltaTCR+ cells with a mature (CD3+) phenotype, but not into alphabetaTCR+ thymocytes. It seems that EGF addition makes the cultures "nonpermissible" for alphabetaTCR+ thymocyte generation. We report here the presence of a high Mr "EGF-like" molecule on the membrane of fetal thymocytes, which role in the observed effects is under investigation. Further biochemical characterization of this molecule is still required, because its presence was only evidenced on the basis of its antigenicity.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Fator de Crescimento Epidérmico/farmacologia , Linfócitos T/citologia , Timo/citologia , Timo/embriologia , Animais , Western Blotting , Eletroforese em Gel de Poliacrilamida , Feminino , Citometria de Fluxo , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Cultura de Órgãos , Gravidez , Linfócitos T/imunologia
17.
Dev Immunol ; 4(2): 139-47, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-9700363

RESUMO

Increasing evidence reveals that extracellular matrix components can be regarded as a group of mediators in intrathymic T-cell migration and/or differentiation. Yet, little is known about the expression and putative function of one particular extracellular matrix protein, namely, tenascin in the thymus. Herein we investigated, by means of immunocytochemistry, tenascin expression in normal infant and fetal human thymuses, as well as in cultures of thymic microenvironmental cells. In situ, tenascin distribution is restricted to the medulla and cortico-medullary regions of normal thymuses. This pattern thus differed from that of fibronectin, laminin and type IV collagen, in which subseptal basement membranes were strongly labeled. Interestingly, tenascin did not co-localize with the cytokeratin-defined thymic epithelial cell network. This was in keeping with the in vitro data showing that tenascin-bearing cells were nonepithelial (and probably nonfibroblastic) microenvironmental elements. Studies with fetal thymuses revealed a developmentally regulated expression of tenascin, with a faint but consistent network labeling, in thymic rudiments as early as 12 weeks of gestational age, that progressed to a strong TN expression at 18 weeks of fetal development, which was similar to the distribution pattern observed thereafter, including postnatally. Our results clearly indicated that tenascin is constitutively expressed in the human thymus, since early stages of thymic ontogeny, and suggest that the cell type responsible for its secretion is a nonepithelial microenvironmental cell.


Assuntos
Tenascina/biossíntese , Timo/metabolismo , Células Cultivadas , Técnicas de Cultura , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Feto , Idade Gestacional , Humanos , Imuno-Histoquímica , Lactente , Especificidade de Órgãos/imunologia , Células Estromais/imunologia , Células Estromais/metabolismo , Timo/citologia , Timo/embriologia
18.
Phytother Res ; 13(7): 613-5, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10548757

RESUMO

The antiarthritic effect of a hydroalcohol extract of Pterodon pubescens (HEPp) seeds was tested using collagen-induced arthritis (CIA) in DBA1/J mice treated with daily oral doses of HEPp in different schedules. The preventive treatment significantly reduced both the arthritic index (AI) and the CIA incidence. Using a therapeutic protocol, only the lower dose of HEPp induced a decrease in both parameters. These results provide a scientific foundation for the popular use of Pp seed infusions in rheumatoid arthritis (RA) treatment.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Colágeno/toxicidade , Extratos Vegetais/uso terapêutico , Plantas Medicinais/química , Animais , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos DBA , Sementes/química
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