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1.
Bioprocess Biosyst Eng ; 34(3): 253-61, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21072543

RESUMO

Agaricus blazei is a mushroom that belongs to the Brazilian biodiversity and is considered as an important producer of bioactive compounds beneficial to human health. Studies have demonstrated that these compounds present immuno-modulatory, antioxidant and antitumor properties. In order to compare the most used method for fungal polysaccharide drying, lyophilization with other industrial-scale methods, the aim of this work was to submit A. blazei LPB 03 polysaccharide extracts to vaucum, spray and freeze drying, and evaluate the maintenance of its antitumoral effects in vitro. Exopolysaccharides produced by A. blazei LPB 03 on submerged fermentation were extracted with ethanol and submitted to drying processes. The efficiency represents the water content that was removed during the drying process. The resultant dried products showed water content around 3% and water activity less than 0.380, preventing therefore the growth of microorganisms and reactions of chemical degradation. Exopolysaccharide extracts dried by vacuum and spray dryer did not showed any significant cytotoxic effect on cell viability of Wistar mice macrophages. Content of total sugars and protein decrease after drying, nevertheless, 20 mg/ml of exopolysaccharides dried by spray dryer reached 33% of inhibition rate over Ehrlich tumor cells in vitro.


Assuntos
Agaricus/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Liofilização/métodos , Extratos Vegetais/farmacologia , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Agaricus/crescimento & desenvolvimento , Agaricus/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Fermentação , Proteínas Fúngicas/análise , Macrófagos , Camundongos , Extratos Vegetais/isolamento & purificação , Polissacarídeos/biossíntese , Água/química , Água/metabolismo
2.
J Obstet Gynaecol ; 30(8): 804-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21126117

RESUMO

The aim of this study was to determine the lipid and lipoproteins ratio in pregnant mothers and to evaluate their role in the interpretation of hyperlipidaemias. A total of 222 pregnant women who registered for ANC and 222 non-pregnant healthy women of the sameage and parity as control were recruited for the study. A sample of venous blood after an overnight fast was collected for analysis and interpretation. The mean ± SD age (years) of pregnant women, 27.317 ± 7.283 years and that of the non-pregnant women, 26.234 ± 6.234 years are not significantly different, p = 0.429. Total cholesterol, HDL-c and TGs were significantly higher in pregnant women (5.29 ± 1.04 mmol/l, 1.64 ± 0.42 mmol/l and 1.74 ± 0.42 mmol/l) compared with that of non-pregnant women (4.64 ± 0.92 mmol/l, 1.25 ± 0.35 mmol/l and 1.37 ± 0.45 mmol/l, respectively) All showed p < 0.000. The frequencies of hypercholesterolaemia, 96(43.2%) and hypertriglyceridaemia, 82 (36.9%), are significantly higher in the pregnant women than in the non-pregnant women, 58 (26.1%) and 26 (11.7%), respectively. TC/HDL-C ratio, 3.33 ± 1.01 and LDL/HDL-C ratio, 1.91 ± 0.85 are significantly lower in pregnant women compared with non-pregnant women counterparts, 3.89 ± 0.97 and 2.35 ± 0.84, respectively. Similarly the frequencies of increased TC/HDL-C ratio, 22 (9.9%) and LDL/HDL-C ratio, 16 (7.2%) are significantly less in the pregnant compared with the non-pregnant women, 54 (24.3%) and 28 (12.6%), respectively.


Assuntos
Hiperlipidemias/sangue , Lipoproteínas/sangue , Complicações na Gravidez/sangue , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Hiperlipidemias/diagnóstico , Gravidez , Complicações na Gravidez/diagnóstico , Estudos Prospectivos , Adulto Jovem
3.
Appl Biochem Biotechnol ; 151(2-3): 283-94, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18516506

RESUMO

The aim of the work was to study the production of the exopolysaccharides by Agaricus brasiliensis and the isolation of exopolysaccharides (EPSs) with biological effects. A brasiliensis LPB03 was cultured in submerged fermentation in a medium containing glucose, yeast extract, hydrolyzed soybean protein, and salts (pH 6.1) at 29 degrees C and 120 rpm for 144 h. The maximum biomass and EPS yield was 7.80 +/- 0.01 and 1,430.70 +/- 26.75 mg/L, respectively. To isolate the produced EPSs, two methods were compared: (1) with alcohol precipitation and (2) treatment with tricloroacetic acid (TCA), followed by alcohol precipitation. The use of TCA facilitated the purification of the EPS, reducing the amount of the contaminant soy proteins. For monosaccharide identification, the EPSs were hydrolyzed, derivatized to alditol acetates, and analyzed by gas chromatography (GC) and GC-mass spectrometry, which showed the presence (in molar percentage) of mannose (58.7), galactose (21.4), and glucose (13.1) as major sugars, with lower amounts of rhamnose (3.9) and xylose (2.8). Scanning electron microscopy was used to observe the morphological structure of the EPS. The experiments in vivo including EPS in the mice diet during 8 weeks indicated the hipocholesteremic and hypoglycemic effects.


Assuntos
Agaricus/metabolismo , Polissacarídeos/biossíntese , Agaricus/crescimento & desenvolvimento , Animais , Anticolesterolemiantes/farmacologia , Biomassa , Glicemia/metabolismo , Colesterol/sangue , Meios de Cultura , Etanol , Feminino , Fermentação , Precipitação Fracionada , Hipoglicemiantes/farmacologia , Camundongos , Microscopia Eletrônica , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Proteínas de Soja , Ácido Tricloroacético
4.
Curr Top Microbiol Immunol ; 324: 95-107, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18481455

RESUMO

Passive antibody administration shows strong potential as a new therapeutic method. In clinical applications, human-derived antibodies with antigen specificity are more useful without putting individuals at risk. Production of human-derived antibodies against given antigens can be obtained from animal models if the human immune system is established in the animals. In fact, past reports revealed that human T and B cells develop from hematopoietic progenitor cells in immunodeficient mice. However, there have been few reports on sufficient induction of antigen-specific antibodies, particularly IgG, in immunodeficient mice reconstituted with human immune cells. In this chapter, we discuss a major shortcoming of induction of antigen-specific IgG antibodies in human immune cells developed in the murine environment based on our data. We demonstrated that human T cell development is restricted by the murine MHC and consequently T cells may not achieve cognate interaction with human B cells. Human B cells developed in the mouse are mainly CD5+B1 cells that preferentially produce IgM. At the same time, human LN transplantation on the spleen enabled NOG mice to produce antigen-specific IgG antibody. These results suggest that if efficient cognate interaction mediated by a certain antigen on MHC class II between human T and B-2 cells occurs, human B cells can produce IgG antibody against a given antigen in the murine environment.


Assuntos
Antígenos/imunologia , Linfócitos B/imunologia , Sistema Imunitário/fisiologia , Imunoglobulina G/biossíntese , Modelos Animais , Animais , Humanos , Camundongos , Camundongos SCID , Linfócitos T/imunologia
5.
Afr J Med Med Sci ; 34(2): 185-8, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16749345

RESUMO

Urolithiasis is a common disorder in Maiduguri and constitutes a significant proportion of surgical diseases in Nigerian Hospitals today. Although, the analysis of the stones is an integral part of the assessment of stone formers, earlier report in Maiduguri did not dwell well on it. We therefore, carry out this study to report on the composition of urinary tract calculi removed during surgery at the University of Maiduguri Teaching Hospital and to find out if stone composition in the area changes with time. Fourty-nine urinary tract calculi removed in the surgery unit of the Hospital in 2003 were chemically analyzed in the Department of Chemical Pathology of the same Hospital. We also retrieved results of stones analyzed in 1989 (41) and 1999 (21) and compared the results with the 49 analyzed in 2003. The results showed a male preponderance with male: female ratio 12:1, and the calculi occurred more in the upper part of the tract (70.9%) than the lower part of the tract (29.1%). Calcium containing stones constituted the majority; 76.9%, uric acid/urate was associated with 16.3% of the stones while struvite constitutes 4.3%, xanthine 1.7% and cystine 0.9%. There was subsequent reduction of struvite stones with time. Urinary tract stone is common in Maiduguri. There is need for identification of risk factors of calculi formation in the environment to enable the health care providers plan preventive measures in order to reduce the high incidence in the area.


Assuntos
Cálculos Urinários/química , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nigéria , Fatores de Risco
6.
Int J Clin Pharmacol Res ; 24(4): 111-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15754915

RESUMO

The aim of our study was to evaluate the diagnostic sensitivity of the new thyrotropin receptor antibody (TRAb) assays (Cosmic TRAb CT, ELISA and Yamasa DYNOtest TRAb). TRAb was positive in 43 of 44 (97.7%) untreated patients with Graves' disease by both TRAb CT and/or ELISA and NYNOtest TRAb. Thus the new TRAb assays were clearly more sensitive than the conventional assay (positivity: 85%). There was a strong positive correlation between the data obtained in TRAb CT and/or ELISA and those obtained in DYNOtest TRAb (r = 0.942, p < 0.0001). There was a significant correlation between the new TRAb and TSAb (r = 0.696, p < 0.0001). Although there was a significant correlation between the new TRAb and thyroid stimulation-blocking antibody (TSBAb), the correlation coefficient was low (r = 0.605, p < 0.0001). The increased sensitivity of the new TRAb assays for Graves' disease provides an advantage over conventional assay.


Assuntos
Autoanticorpos/sangue , Doença de Graves/diagnóstico , Imunoglobulinas Estimuladoras da Glândula Tireoide/sangue , Receptores da Tireotropina/imunologia , Autoanticorpos/imunologia , Doença de Graves/imunologia , Humanos , Imunoensaio , Imunoglobulinas Estimuladoras da Glândula Tireoide/imunologia , Sensibilidade e Especificidade
7.
Clin Exp Immunol ; 133(1): 22-9, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12823274

RESUMO

The interaction between CD40 and its ligand (CD154) is crucial for IL-12 production and effective humoral immunity such as IgE production. Although the interaction seems to play a crucial role in asthmatic inflammation, previous studies investigating the role of the CD40 and CD154 interaction in experimental animal models of asthma are complicated due to multistep reactions in developing asthma. Here, in order to investigate the role of CD40 in the effector phase in the development of airway responses, we used CD40-deficient mice backcrossed with mice transgenic for an ovalbumin (OVA)-specific TCR (TCRtg). Using intranasal OVA administration followed by aerosol inhalation of OVA, greater airway hyperreactivity and eosinophilia in bronchoalveolar lavage fluid (BALF) were observed in CD40-deficient mice backcrossed with TCRtg mice (CD40-/-/ TCRtg mice), compared with control littermates (CD40+/+/ TCRtg mice). CD4+ helper T cell subset analysis of lung draining lymph nodes revealed that the Th1 component was significantly decreased in CD40-/-/ TCRtg mice. Airway hyperreactivity and airway eosinophilia significantly correlated with the predomination of Th2 cells. Cytokine measurements in BALF also showed decreased IL-12 and the predominance of Th2 cells in CD40-/-/ TCRtg mice. These results suggest that CD40 may play a protective role in developing asthma in the phase after establishing specific memory T cells through the regulation of the balance between Th1 and Th2 cells presumably via induction of IL-12.


Assuntos
Hiper-Reatividade Brônquica/imunologia , Antígenos CD40/imunologia , Ligante de CD40/imunologia , Animais , Hiper-Reatividade Brônquica/patologia , Líquido da Lavagem Broncoalveolar/imunologia , Broncoconstritores , Antígenos CD40/genética , Suscetibilidade a Doenças , Eosinófilos/imunologia , Interferon gama/análise , Interleucina-12/análise , Interleucina-4/análise , Contagem de Leucócitos , Pulmão/patologia , Cloreto de Metacolina , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/genética
8.
Clin Exp Allergy ; 32(4): 563-70, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11972603

RESUMO

BACKGROUND: Our previous study using allergen-sensitized murine splenocyte cultures has shown that Lactobacillus casei strain Shirota (LcS), a lactic acid bacterium widely used as a starter for fermented milk products, suppresses IgE production through promoting a dominant Th1-type response mediated by IL-12 induction. OBJECTIVE: We tried to evaluate the ability of LcS to suppress both IgE response and allergic reactions in vivo using a food allergy model with ovalbumin-specific T cell receptor transgenic (OVA-TCR-Tg) mice. METHODS: The ability of heat-killed LcS to induce IL-12 in serum was tested. OVA-TCR-Tg mice were fed a diet containing OVA for 4 weeks and injected with LcS intraperitoneally three times in the first week of this period. Cytokine and antibody secretion by splenocytes, and serum IgE and IgG1 responses were examined. The inhibitory effect of LcS on systemic anaphylaxis induced by intravenous challenge of OVA-fed OVA-TCR-Tg mice with OVA was also tested. RESULTS: Intraperitoneal injection of LcS induced an IL-12 response in the serum of OVA-TCR-Tg mice. In the food allergy model, LcS administration skewed the pattern of cytokine production by splenocytes toward Th1 dominance, and suppressed IgE and IgG1 secretion by splenocytes. The ability of LcS to modulate cytokine production was blocked by anti-IL-12 antibody treatment. LcS also inhibited serum OVA-specific IgE and IgG1 responses and diminished systemic anaphylaxis. CONCLUSION: LcS administration suppresses IgE and IgG1 responses and systemic allergic reactions in a food allergy model, suggesting a possible use of this lactic acid bacterium in preventing food allergy.


Assuntos
Anafilaxia/prevenção & controle , Hipersensibilidade Alimentar/imunologia , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Lacticaseibacillus casei , Animais , Anticorpos/farmacologia , Células Cultivadas , Citocinas/biossíntese , Genes Codificadores dos Receptores de Linfócitos T , Imunoglobulina E/biossíntese , Imunoglobulina G/biossíntese , Interleucina-12/antagonistas & inibidores , Interleucina-12/sangue , Interleucina-12/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Ovalbumina/imunologia , Fragmentos de Peptídeos/imunologia , Baço/citologia , Baço/imunologia , Células Th1/imunologia
9.
Int Immunol ; 13(12): 1561-70, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11717197

RESUMO

Although some animal models suggest an involvement of CD4 T cells reactive to luminal microbial antigen(s) for the pathogenesis of inflammatory bowel diseases (IBD), direct linkage between microflora-driven clonal expansion of CD4 T cells and the development of colitis has not been well studied. Here, BALB/c and SCID mice were given CD4 T cells purified from Rag-2(-/-) mice crossed to transgenic mice expressing TCR specific to ovalbumin (OVA) then administered with antibiotic-resistant Escherichia coli producing OVA (ECOVA) or LacZ (ECLacZ) via the rectum. The ECOVA-inoculated BALB/c and SCID mice developed a subacute colitis with microscopic features of distortion of crypt architecture, loss of goblet cells, and focal infiltration by mononuclear cells in the lamina propria (LP) and submucosa. Expanding OVA-specific CD4 T cells were detected in colonic follicles of mice with ECOVA. Early in colitis, OVA-specific CD4 T cells producing IFN-gamma predominate in the LP of the colon, which was followed by an emergence of OVA-specific CD4 T cells producing IL-4 and IL-10 at a later time point. Co-transfer of an IL-10-secreting OVA-specific CD4 T cell line prevented colitis. Thus, an expansion of CD4 T cells monospecific to OVA, an antigen non-cross-reactive to colonic tissue, can mediate both induction and inhibition of the colitis which was associated with hyperplasia of lymph follicles.


Assuntos
Transferência Adotiva , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/transplante , Colite/imunologia , Epitopos de Linfócito T/imunologia , Escherichia coli/imunologia , Ovalbumina/imunologia , Administração Retal , Transferência Adotiva/métodos , Animais , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/biossíntese , Antígenos de Bactérias/genética , Linfócitos T CD4-Positivos/metabolismo , Linhagem Celular , Colite/patologia , Colite/prevenção & controle , Colo/patologia , Citocinas/biossíntese , Modelos Animais de Doenças , Epitopos de Linfócito T/administração & dosagem , Epitopos de Linfócito T/genética , Escherichia coli/genética , Injeções Intravenosas , Interleucina-10/biossíntese , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Óperon Lac/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos SCID , Camundongos Transgênicos , Ovalbumina/administração & dosagem , Ovalbumina/biossíntese , Ovalbumina/genética , Plasmídeos/administração & dosagem , Plasmídeos/biossíntese , Plasmídeos/imunologia , Síndrome de Emaciação/imunologia
10.
Neuroendocrinology ; 74(5): 281-7, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11694760

RESUMO

Ciliary neurotropic factor (CNTF) is a neuroregulatory cytokine belonging to the interleukin-6 type cytokine superfamily. Although a few studies have reported a facilitatory action of CNTF on the reproductive axis in rodents, information along this line is still very limited. In this study, we examined a possible role of CNTF in the generation of ovarian steroid-induced luteinizing hormone (LH) and prolactin (PRL) surges in the rat, a crucial physiological event in mammalian reproduction. Experiments were performed on both normally-fed and 3-day-fasted rats, ovariectomized and primed with estradiol and progesterone. Blood was collected every 30 min between 11:00 and 18:00 h, to measure LH and PRL. Drugs were given intracerebroventricularly at 11:00 h. Compared to control serum, undiluted as well as threefold dilutions of anti-CNTF serum caused partial but significant suppression of LH surges. Both concentrations of the antibody also delayed the onset of PRL surge to a comparable degree. Fasted rats did not exhibit significant surges of the hormones, while 0.3 and 1.0 nmol, but not 0.1 nmol, recombinant human CNTF led to a dose-dependent recovery of both LH and PRL surges. These results demonstrate for the first time a significant role of CNTF in the generation of preovulatory LH and PRL surges in the rat. CNTF may thus be another humoral signal linking nutrition and reproductive function.


Assuntos
Fator Neurotrófico Ciliar/fisiologia , Fase Folicular/fisiologia , Hormônio Luteinizante/metabolismo , Prolactina/metabolismo , Animais , Encéfalo/metabolismo , Fator Neurotrófico Ciliar/imunologia , Fator Neurotrófico Ciliar/farmacologia , Feminino , Humanos , Soros Imunes/imunologia , Injeções Intraventriculares , Ovário/metabolismo , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia
11.
J Immunol ; 167(9): 4957-65, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11673502

RESUMO

To understand the gene regulation involved in the development of single-positive (SP) thymocytes, we generated transgenic mice in which the AML1 transcription factor is overexpressed. In these mice the number of CD8 SP thymocytes was greatly increased, and this continued to be true even when MHC class I was absent. This promotion to the CD8 SP lineage was not, however, observed when both class I and class II were absent. Furthermore, even thymocytes carrying MHC class II-restricted TCR differentiated into the CD8 SP lineage when AML1 was overexpressed. The selected CD8 SP cells were, however, unable to mature, as judged by the expression level of heat-stable Ag. Thus, overexpression of AML1 is able to skew class II-restricted thymocytes into the CD8 SP lineage, but not to drive the maturation of resulting selected CD8 SP cells.


Assuntos
Antígenos CD8/análise , Linhagem da Célula , Proteínas de Ligação a DNA/fisiologia , Proteínas Proto-Oncogênicas , Linfócitos T/fisiologia , Fatores de Transcrição/fisiologia , Animais , Antígenos CD4/análise , Subunidade alfa 2 de Fator de Ligação ao Core , Antígenos de Histocompatibilidade Classe I/fisiologia , Antígenos de Histocompatibilidade Classe II/fisiologia , Camundongos , Camundongos Transgênicos
12.
Cell Immunol ; 211(1): 71-9, 2001 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-11585390

RESUMO

It has been reported that the three-dimensional structure of thymic epithelial cells (TECs) is responsible for thymic positive selection but that this ability disappears when TECs are cultured in monolayer. These results have supported the hypothesis that certain TEC-specific molecules are extinguished during monolayer culture. In this study, using MHC class II-restricted T-cell receptor transgenic mice, we demonstrated that preselected CD4(+)8(+) (DP) thymocytes were inhibited from developing into CD4(+)8(-) (CD4SP) cells in reaggregate thymus organ culture with monolayer-cultured TECs, but this inhibition was removed when TECs were cultured in monolayer with protein synthesis inhibitor or when the cultured TECs were treated with fixative. These results seem to be inconsistent with the previous hypothesis and indicate that monolayer culture allows TECs to retain the surface molecules necessary for positive selection but interferes with their function, which must be sustained for three dimensional structure.


Assuntos
Células Epiteliais/fisiologia , Linfócitos T/imunologia , Timo/citologia , Timo/imunologia , Animais , Diferenciação Celular , Células Cultivadas , Cicloeximida/farmacologia , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Fixadores/química , Interleucina-2/biossíntese , Proteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Técnicas de Cultura de Órgãos/métodos , Inibidores da Síntese de Proteínas/farmacologia , Receptores de Antígenos de Linfócitos T/genética , Células Estromais/fisiologia
13.
Int Immunol ; 13(11): 1405-14, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11675372

RESUMO

We have generated mutant mice in which TCR beta chain enhancer (E(beta)) was replaced with the TCR alpha chain enhancer (E(alpha)). Using this mouse model, we analyzed (i) recombination status of the TCR beta chain genes after functional V(D)J rearrangements occurred in the first allele during double-negative (DN)-to-double-positive (DP) transition and (ii) involvement of E(beta) for the expression of rearranged TCR beta chain genes. Our data show that E(alpha) substituted for E(beta) function to express a similar extent of TCR beta chains exactly at the same time as did E(beta) (CD25+CD44- DN stage), although the proportion of TCR beta+ cells at this stage was low in mutant mice. At the DP stage, germline transcription and histone acetylation of D(beta)-J(beta) loci were detectable at a high degree in both mutant and wild-type mice. However, DP cells in mutant mice retained the germline D(beta)-J(beta) configuration at a higher frequency than that of wild-type mice, whereas both DP cells expressed TCR beta chains to a similar extent. These data suggest that chromatin opening has a limited impact on D(beta)-to-J(beta) recombination at the DP stage and that E(alpha) is functionally equivalent to E(beta) in promoting expression of functionally rearranged TCR beta chain genes through DN-to-DP transition.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Cromatina/fisiologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Timo/imunologia , Animais , Elementos Facilitadores Genéticos , Mutação em Linhagem Germinativa , Camundongos , Camundongos Mutantes , Recombinação Genética
14.
J Biol Chem ; 276(45): 41717-24, 2001 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-11546792

RESUMO

Tumor suppressor p53 has been shown to transactivate epidermal growth factor receptor (EGFR) expression through binding to a putative p53 responsive element in the EGFR promoter between nucleotides -265 and -239 (EGFRp53RE). Isotypes of p63 gene products, recently identified as p53 relatives, have a similar function to transactivate several p53 target gene promoters. However, our results indicate that TAp63gamma has a very low ability to bind to the EGFRp53RE and surprisingly represses both basal EGFR promoter activity and endogenous EGFR expression. Transient transfection assays show that the EGFR promoter region between -348 and -293, containing two Sp1 sites, is crucial for the repression of the EGFR expression by TAp63gamma. Mutations in these Sp1 sites in the reporter constructs result in loss of the TAp63gamma repression effect. We further show that TAp63gamma directly interacts with Sp1 by immunoprecipitation analysis and that TAp63gamma impairs Sp1 binding to the target DNA site in electrophoretic mobility shift assays. These results suggest that TAp63gamma is involved in the regulation of the EGFR gene expression through interactions with basal transcription factors.


Assuntos
Receptores ErbB/genética , Proteínas de Membrana , Fosfoproteínas/fisiologia , Proteínas Repressoras/fisiologia , Transativadores/fisiologia , DNA/metabolismo , Proteínas de Ligação a DNA , Genes Supressores de Tumor , Humanos , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Elementos de Resposta , Fator de Transcrição Sp1/metabolismo , Fatores de Transcrição , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor
15.
Biochem Biophys Res Commun ; 286(3): 628-34, 2001 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-11511106

RESUMO

The p51/p73L/p63/p40 gene, recently identified as a p53 homolog, encodes two major isoforms, p51A and p73L, which are suggested to have similar functions synonymous with p53 and dominant-negative activity toward both p53 and p51A, respectively. We have cloned a high affinity genomic fragment bound to p51A that was assigned to be a novel retrovirus long terminal repeat. Strikingly, this fragment was found to bind to both p53 and p73L with similar affinity to p51A. Additional demonstration with known p53 response elements suggested that DNA-binding profiles of p51A and p73L were very similar but were distinct from that of p53. Consistent with this novel finding, transient cotransfection experiments in mammalian cells suggested that p73L, when it was expressed at a low level, selectively suppressed p53-dependent transactivation of p21-luc and mdm2-luc but not of cyclinG-luc and bax-luc reporters. These data raise the possibility that p73L differentially modulates the p53 function according to the distinct DNA-binding affinity between these two proteins.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Proteínas Nucleares/fisiologia , Fosfoproteínas , Retroviridae/genética , Sequências Repetidas Terminais , Transativadores , Proteína Supressora de Tumor p53/fisiologia , Animais , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , Sequência Consenso , Proteínas de Ligação a DNA/genética , Genes Supressores de Tumor , Camundongos , Dados de Sequência Molecular , Mutação , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Fatores de Transcrição , Proteína Tumoral p73 , Proteínas Supressoras de Tumor
16.
Br J Cancer ; 84(9): 1235-41, 2001 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-11336476

RESUMO

We have recently identified a second p53 -related p73L gene, also referred to as p63 / p51 / p40 / KET gene, which encodes the 2 major isoforms p73L and p51 resulting from different exon usage at their amino terminal regions. Although p73L and p51 are suspected to play oncogenic and tumour suppressive roles in mammalian cells, respectively, no evidence of linkage between the expression of these isoforms and human cancers has been reported so far. In this study, we first investigated the expression profile of p51 and p73L in various human tumour cell lines and found that a novel isoform, termed DeltaNp73L, was predominantly expressed in squamous cell carcinomas. The expression profile of DeltaNp73L/p73L/p51 in primary human skin cancer specimens showed that the expression of p51 was frequently lost (62%) but was detected in all normal skin samples. In p51-expressing skin cancers, DeltaNp73L expression was associated at a high frequency (75%) though it was not detected in normal skin tissues. Transient co-transfection data indicate the possibility that DeltaNp73L can inhibit p53-, and more preferentially, p51-mediated transactivation. These data suggest that the loss of expression of p51 and/or the expression of DeltaNp73L might contribute to the pathogenesis of human squamous cell carcinomas.


Assuntos
Carcinoma de Células Escamosas/genética , Proteínas de Ligação a DNA/biossíntese , Regulação Neoplásica da Expressão Gênica , Proteínas de Membrana , Proteínas Nucleares/biossíntese , Fosfoproteínas/biossíntese , Proteínas , Neoplasias Cutâneas/genética , Transativadores , Proteína Supressora de Tumor p53/biossíntese , Carcinoma de Células Escamosas/fisiopatologia , Linhagem Celular , Proteínas de Ligação a DNA/genética , Genes Supressores de Tumor , Humanos , NADPH Oxidases , Proteínas Nucleares/genética , Fosfoproteínas/genética , Neoplasias Cutâneas/fisiopatologia , Fatores de Transcrição , Transcrição Gênica , Proteína Tumoral p73 , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor
17.
Endocr Regul ; 35(1): 31-4, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11308994

RESUMO

OBJECTIVE: To develop radioimmunoassay for somatostatin receptor type 2 (SSTR2) and search for its presence in certain rat tissues. METHODS: Anti-SSTR2 antiserum has been raised in New Zealand white rabbits immunized with a conjugate of synthetic SSTR2 with bovine serum albumin. Radioiodination of SSTR2 was performed by chloramin T method followed by purification of radioiodinated material on Sephadex G-25 column. RESULTS: The obtained antibody did not crossreact with SSTR1, SSTR3, SSTR4, SSTR5, hypothalamic hormones, pituitary hormones, neuropeptides or gut hormones. The assay was performed with a double antibody system. SSTR2 was extracted from the tissues with acid acetone. The dilution curve of acid acetone-extracts of rat hypothalamus in the radioimmunoassay system was parallel to the standard curve. The recovery of tissue SSTR2 was about 89 %, and the intra-assay and inter-assay variations were 4.9 % and 7.8 %, respectively. SSTR2 was found in the hypothalamus, cerebrum, cerebellum, pituitary, stomach and testis. CONCLUSIONS: These data suggest that this assay system is suitable for the estimation of SSTR2 in the tissues.


Assuntos
Receptores de Somatostatina/análise , Acetona , Animais , Especificidade de Anticorpos , Química Encefálica , Cerebelo/química , Hipotálamo/química , Soros Imunes , Radioisótopos do Iodo , Marcação por Isótopo , Masculino , Hipófise/química , Controle de Qualidade , Coelhos , Ratos , Ratos Wistar , Estômago/química , Telencéfalo/química , Testículo/química
18.
Rinsho Byori ; 49(11): 1122-8, 2001 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-11769558

RESUMO

We tried to investigate the present problems, concerning the reference individual and interval in thyroid function tests and find the solutions for them. We are now using healthy adults for the reference individual and interval. Recently, we found the sex-difference and age-related changes for reference individual and interval in free T3 measurement. We raised the questions on whether there are any sex-differences and/or age-related changes or not. Surprisingly, there were almost no detailed data about them especially in Japan. Therefore, we examined the Europe data, and found out some kind of sex-differences and age-related changes. We propose the following examinations using many Japanese population in order to provide a precise and proper reference individual and interval: 1. Whether there are any sex-difference in thyroid function tests? 2. Whether there are age-related change in thyroid function tests, for instance, simply dividing population into the immature, adult and the aged?


Assuntos
Testes de Função Tireóidea/normas , Hormônios Tireóideos/sangue , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Tireotropina/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue
19.
J Immunol ; 166(1): 353-60, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11123312

RESUMO

Mutations in the CD40 ligand (CD40L) gene lead to X-linked immunodeficiency with hyper-IgM, which is often associated with autoimmune diseases. To determine the contribution of defective CD40-CD40L interactions to T cell autoreactivity, we reconstituted CD40-CD40L interactions by transferring T cells from CD40-deficient mice to syngenic athymic nude mice and assessed autoimmunity. T cells from CD40-deficient mice triggered autoimmune diseases accompanied with elevations of various autoantibodies, while those from wild-type mice did not. In CD40-deficient mice, the CD25(+) CD45RB(low) CD4(+) subpopulation which regulates T cell autoreactivity was markedly reduced. CD40-deficient APCs failed to induce T regulatory cells 1 producing high levels of an inhibitory cytokine, IL-10 in vitro. Furthermore, autoimmune development was inhibited when T cells from CD40-deficient mice were cotransferred with CD45RB(low) CD4(+) T cells from wild-type mice or with T regulatory cells 1 induced on CD40-expressing APCs. Collectively, our results indicate that CD40-CD40L interactions contribute to negative regulation of T cell autoreactivity and that defective interactions can lead to autoimmunity.


Assuntos
Autoantígenos/imunologia , Antígenos CD40/fisiologia , Ligante de CD40/genética , Ligante de CD40/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/patologia , Autoanticorpos/biossíntese , Autoanticorpos/sangue , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Antígenos CD40/genética , Antígenos CD40/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Antígenos Comuns de Leucócito/biossíntese , Contagem de Linfócitos , Linfopenia/genética , Linfopenia/imunologia , Linfopenia/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Camundongos Nus , Receptores de Interleucina-2/biossíntese , Subpopulações de Linfócitos T/patologia , Subpopulações de Linfócitos T/transplante
20.
J Immunol ; 165(12): 6816-24, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11120804

RESUMO

In the thymic cortex, T lymphocytes are positively selected to survive and committed either to the CD4 single-positive (SP) or the CD8 SP lineage. The SP cells then pass through a step of maturation in the medulla and are delivered to peripheral lymphoid tissues. We examined the role of AML1, the gene encoding a transcription factor, in the above processes by using the transgenic mice expressing a dominant interfering form of AML1 as well as mice targeted heterozygously for AML1. One phenotypic change seen in the AML1-diminished mice was the reduction in the numbers of both CD4 SP and CD8 SP thymocytes, reflecting the partial impairment of the transition from the double-positive to SP stage. In addition, distinct from the above abnormality, perturbed were several aspects of SP cells, including the maturation of SP thymocytes, the recent thymic emigration, and the proliferative responsiveness of peripheral T cells to TCR stimulation. Interestingly, the AML1 diminution caused inhibitory and enhancing effects on the CD4 SP and CD8 SP cells, respectively. These differential effects are most likely related to the reduction in the peripheral CD4 SP/CD8 SP ratio observed in the AML1-diminished mice. The AML1 transcription factor thus maintains the homeostasis of each SP subset by functioning at the later stages of T lymphocyte differentiation.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/fisiologia , Proteínas Proto-Oncogênicas , Subpopulações de Linfócitos T/metabolismo , Fatores de Transcrição/deficiência , Fatores de Transcrição/fisiologia , Animais , Relação CD4-CD8 , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Movimento Celular/imunologia , Células Cultivadas , Subunidade alfa 2 de Fator de Ligação ao Core , Cruzamentos Genéticos , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila , Ativação Linfocitária/genética , Tecido Linfoide/imunologia , Tecido Linfoide/patologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Nucleares , Fenótipo , Receptores de Antígenos de Linfócitos T/fisiologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Timo/citologia , Timo/imunologia , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
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