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1.
Int Endod J ; 54(3): 454-463, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33063865

RESUMO

AIM: To evaluate the current situation of undergraduate endodontic teaching in Spanish dental schools. METHODOLOGY: An online version, translated into Spanish, of a survey conducted in the UK (Int Endod J 52, 2019, 1077) was sent via email to the undergraduate endodontic programme leads in all 23 Spanish dental schools. RESULTS: The response rate was 96%. In 95% of dental schools, endodontics is taught in the fourth year. Students treat simple root canal treatment cases in 100% of schools and only in 40% treat moderate cases. In 65% of schools, students are supervised by full-time professors who are specialists in Endodontics, significantly more frequently in private dental schools (P = 0.002). Spanish dental schools use both rotary and reciprocating instrumentation systems during endodontic training, with consistency on methods of working length determination, use of silicate-based endodontic cements, irrigating solutions, inter-visit medicaments and canal filling techniques. No type of magnification is used in 90% of dental schools, and only 25% use ultrasonic instruments. Private dental schools have a significantly better staff: student ratio during clinical practice (P = 0.041), spend significantly more hours in clinical training (P = 0.04) and have significantly greater number of clinical areas specifically dedicated to Endodontics (P = 0.010). CONCLUSIONS: Undergraduate endodontic teaching in Spanish dental schools follows the key recommendations of the ESE Undergraduate Curriculum Guidelines (Int Endod J 46, 2013, 1105), being, in most respects, comparable to that carried out in the UK (Int Endod J 52, 2019, 1077). The use of magnification and ultrasonic instruments needs to be increased. Private schools reported better results than public schools in some of the variables that were analysed.


Assuntos
Endodontia , Educação em Odontologia , Humanos , Faculdades de Odontologia , Espanha , Estudantes , Inquéritos e Questionários
2.
Ceylon Med J ; 64(2): 46-51, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31455066

RESUMO

Interpretation: RAS-RAF-MEK-ERK is a key pathway for apoptosis regulation in cancer cells. B-Raf-inhibitors such as PLX4032 peptide was developed by Institute Curie-Université Pierre et Marie Curie in order to induce apoptosis in cancer cells. Objectives: To demonstrate pro-apoptotic properties and survival outcome of EP2014/064243 peptide in murine aggressive lymphoma. Material and Methodology: BALBc mice with T-lymphoma were randomized assigned either in Group A (peptide+cyclophosphamide-CFM); Group B (peptides), Group C (CFM-control) or Control D (Cl-Na 0.9%-SF control group). Survival probability was calculated by Kaplan-Meier analysis. Apoptosis was detected using TUNEL technique. The protocol was approved by the Institutional Committee for Animal Care (CICUAL: T04-01-2015) Results: The median survival was 24 days (21.6-26.4) for placebo, 33 days (28.0-35.4) for the CFM monotherapy group, 33 (27.1-35.8) for the peptide group and 34 days (24,4-40) for CFM-peptide combined treatment (p<0.05). In lymph node tissue the mean TUNEL positive cells per field for each treatment group was 2, 12 and 13 and 35 for SF, CFM, peptide and combined therapy (p<0.05). Conclusion: These findings suggest that in murine aggressive lymphoma treated by an experimental peptide in addition with CFM, had an exponentially pro-apoptotic effect than CFM alone, suggesting that the peptide potentiated the anti-tumoural effect of CFM.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linfoma/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Vemurafenib/farmacologia , Animais , Modelos Animais de Doenças , Estimativa de Kaplan-Meier , Linfoma/mortalidade , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas ras/metabolismo
3.
Rev Esp Quimioter ; 36(2): 169-179, 2023 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-36645021

RESUMO

OBJECTIVE: To estimate the prevalence of unknown HIV infection in patients who consulted in hospital emergency services (ED) for conditions defined in the SEMES-GESIDA Consensus Document (DC), evaluate the efficiency of its im-plementation and investigate the efficiency of HIV serology determination in other conditions. METHODS: Results were reviewed in 10 Catalan EDs for 12 months (July-21-June-22) after implementing CD recommendations: request HIV serology in case of suspected sexually transmitted infection, chemsex, post-exposure prophylaxis (PEP), mononucleosis syndrome, community pneumonia (18-65 y-o) or herpes zoster (18-65 y-o). Other reasons for request were included. Prevalence (%) of global seropositivity and for each circumstance was calculated, with a 95% confidence interval (95%CI). The efficient strategy was considered if the lower limit of the CI95%>0.1%. RESULTS: A total of5,107 HIV serologies were performed: 2,847(56%) in situations specified in CD, and 2,266 (44%) in other 138 circumstances. Forty-eight unknown HIV infections were detected (prevalence=0.94%;95%CI=0.69-1.24). The prevalence was somewhat higher in DC requests (30 cas-es 1.12%) than the rest (18 cases 0.71%; p=0.16). The individualized prevalence of CD reasons ranged between 7.41% (95%CI=0.91-24.3) in chemsex and 0.42% 95%CI=0.14-0.98) in PPE, always efficient except herpes zoster (0.76%; CI95%=0.02-4.18). In other reasons, cases were detected in 12 circumstances, and in four the determination could be efficient: lymphopenia (10%;CI95%=0.25-44.5), fever with polyarthralgia-polyarthritis (7.41%;CI95% =0.91-24.3), behavioral alteration-confusion-encephalopathy (3.45%;95%CI=0.42-11.9) and fever of unknown origin (2.50%;95%CI=0.82-5.74). CONCLUSIONS: The determination of HIV serology in HES in the processes defined by DC SEMES-GESIDA is efficient. Some circumstances are identified that could be added to those previously contemplated to increase efficiency.


Assuntos
Infecções por HIV , Herpes Zoster , Infecções Sexualmente Transmissíveis , Humanos , Infecções por HIV/epidemiologia , Infecções Sexualmente Transmissíveis/epidemiologia
4.
Rev Neurol (Paris) ; 168(3): 239-56, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22386676

RESUMO

Malaria is still the world's major important parasitic disease and is responsible for the death of more people than any other communicable disease except tuberculosis. A major change in recent years has been the recognition that severe malaria, predominantly caused by Plasmodium falciparum, is a complex multi-system disorder presenting with a range of clinical features. Some surviving patients have an increased risk of neurological and cognitive deficits, behavioural difficulties and epilepsy, making cerebral malaria a leading cause of childhood neurodisability in the malaria transmission area. It is unclear how an intravascular parasite causes such brain injury. Understanding of these mechanisms is important to develop appropriate neuroprotective interventions. However, due to the high specificity of P. falciparum to the human host and to the fact that clinical studies in human are not always feasible, our knowledge about this syndrome mainly comes from autopsy studies which can only give us a limited view of this deadly syndrome. Efforts developed by the scientific community have shown that development of severe malaria probably results from a combination of parasite-specific factors such as adhesion and sequestration to the vascular endothelium, the release of bioactive molecules, together with host inflammatory responses and metabolic acidosis. Recent studies have shown that endothelial cells could play a central role in the onset of the severe malaria. Indeed, adhesion of parasitized erythrocytes to these cells could drive their activation, which could participate in the trigger of an immune response and haemostatic derangements. Moreover, death of endothelial cells could be at the origin of the blood-lung/brain barrier breakdown. Despite the efforts to find new mechanisms, which explain the physiopathology of severe malaria, research progress is slowed down by the lack of experimental models, which reproduce this complex multi-system disorder. In absence of a vaccine so far, the rapid diagnosis of the disease, an efficient treatment, a correct management and nursing care are the only weapons to control mortality due to P. falciparum. It is important to note that in the future, the treatment of severe malaria may involve adjuvant treatments in addition to a potent antimalarial drug. In the present review, we summarize both what is known and practically useful for a physician, and the most promising and current topics of research.


Assuntos
Malária Cerebral/terapia , Adulto , Animais , Antimaláricos/uso terapêutico , Criança , Efeitos Psicossociais da Doença , Modelos Animais de Doenças , Feminino , Haplorrinos , Humanos , Controle de Infecções , Malária Cerebral/complicações , Malária Cerebral/diagnóstico , Malária Cerebral/epidemiologia , Malária Cerebral/parasitologia , Camundongos , Plasmodium falciparum/fisiologia , Gravidez , Prognóstico
5.
Transplant Proc ; 51(1): 83-86, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30655140

RESUMO

INTRODUCTION: Portal vein thrombosis (PVT) is a relatively common finding in patients undergoing liver transplantation. Although the recommendation to prevent its recurrence is anticoagulation for a duration of 3 to 6 months, this is controversial. AIM: The aim of our study was to determine the efficacy of oral anticoagulants (OAC) as prophylaxis for recurrent PVT after liver transplantation. MATERIALS AND METHODS: Our study included 215 liver transplant patients who underwent surgery in our center from January 2012 to August 2017. We selected all patients diagnosed with PVT either pre-transplantation (using Doppler echography or Angio-CT) or during transplant surgery. All patients with PVT were initially anticoagulated with low-molecular-weight heparin in the postoperative period; at discharge they received OAC for a duration of six months. Control Doppler ultrasound was performed at 3, 6, and 12 months post-transplantation. RESULTS: PVT was identified in 37 out of 215 patients (17.2%). PVT was diagnosed with a pre-transplant vascular study in 17 out of 37 cases (45.9%). All patients were anticoagulated with OAC (warfarin) for at least 6 months. There were no cases of recurrent thrombosis and no complications associated with anticoagulant treatment throughout the follow-up period. CONCLUSIONS: The prevalence of portal thrombosis in liver transplant patients in our study was fairly high, at 17.2%. PVT was identified in nearly 50% of patients using high-quality vascular studies prior to transplant surgery. Anticoagulation with OAC for 6 months was effective in preventing a recurrence of thrombosis and there were no associated complications.


Assuntos
Anticoagulantes/uso terapêutico , Transplante de Fígado , Veia Porta/patologia , Trombose Venosa/prevenção & controle , Adulto , Feminino , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Prevalência , Recidiva , Estudos Retrospectivos , Trombose Venosa/epidemiologia , Trombose Venosa/etiologia , Varfarina/uso terapêutico
6.
J Med Life ; 11(1): 83, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29697701

RESUMO

[This corrects the article on p. 172 in vol. 10, PMID: 29075346.].

7.
Biosens Bioelectron ; 22(9-10): 2132-7, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-17084071

RESUMO

An electrochemical DNA sensor based on the hybridization recognition of a single-stranded DNA (ssDNA) probe immobilized onto a gold electrode to its complementary ssDNA is presented. The DNA probe is bound on gold surface electrode by using self-assembled monolayer (SAM) technology. An optimized mixed SAM with a blocking molecule preventing the nonspecific adsorption on the electrode surface has been prepared. In this paper, a DNA biosensor is designed by means of the immobilization of a single stranded DNA probe on an electrochemical transducer surface to recognize specifically Escherichia coli (E. coli) 0157:H7 complementary target DNA sequence via cyclic voltammetry experiments. The 21 mer DNA probe including a C6 alkanethiol group at the 5' phosphate end has been synthesized to form the SAM onto the gold surface through the gold sulfur bond. The goal of this paper has been to design, characterise and optimise an electrochemical DNA sensor. In order to investigate the oligonucleotide probe immobilization and the hybridization detection, experiments with different concentration of DNA and mismatch sequences have been performed. This microdevice has demonstrated the suitability of oligonucleotide Self-assembled monolayers (SAMs) on gold as immobilization method. The DNA probes deposited on gold surface have been functional and able to detect changes in bases sequence in a 21-mer oligonucleotide.


Assuntos
Técnicas Biossensoriais/instrumentação , DNA , Eletroquímica , Escherichia coli O157/isolamento & purificação , Escherichia coli O157/genética , Marcadores Genéticos , Hibridização de Ácido Nucleico
8.
Mol Cell Biol ; 20(10): 3407-16, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10779330

RESUMO

We have analyzed the interleukin-4 (IL-4)-triggered mechanisms implicated in cell survival and show here that IL-4 deprivation induces apoptotic cell death but does not modulate Bcl-2 or Bcl-x expression. Since Bcl-x expression is insufficient to ensure cell survival in the absence of IL-4, we speculate that additional molecules replace the antiapoptotic role of Bcl-2 and Bcl-x in an alternative IL-4-triggered pathway. Cell death is associated with Bcl-3 downregulation and Bcl-3 expression blocks IL-4 deprivation-induced apoptosis, suggesting that Bcl-3 acts as a survival factor in the absence of growth factor. To characterize the IL-4-induced regulation of murine Bcl-3 expression, we cloned the promoter of this gene. Sequencing of the promoter showed no TATA box element but did reveal binding sites for AP1, AP1-like, and SP1 transcription factors. Retardation gels showed that IL-4 specifically induces AP1 and AP1-like binding activity and that mutation of these binding sites abolishes the IL-4-induced Bcl-3 promoter activity, suggesting that these transcription factors are important in Bcl-3 promoter transactivation. IL-4 deprivation induces downregulation of Jun expression and upregulation of Fos expression, both of which are proteins involved in the formation of AP1 and AP1-like transcription factors. Overexpression of Jun family proteins transactivates the promoter and restores Bcl-3 expression in the absence of IL-4 stimulation. Taken together, these data describe a new biological role for Bcl-3 and define the regulatory pathway implicated in Bcl-3 expression.


Assuntos
Interleucina-4/farmacologia , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/genética , Linfócitos T/citologia , Fator de Transcrição AP-1/metabolismo , Animais , Apoptose , Proteína 3 do Linfoma de Células B , Sequência de Bases , Divisão Celular , Linhagem Celular , Sobrevivência Celular , Clonagem Molecular , Regulação da Expressão Gênica , Camundongos , Dados de Sequência Molecular , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Receptores de Interleucina-2/genética , Análise de Sequência de DNA , Deleção de Sequência , Fatores de Transcrição , Proteína bcl-X
9.
Mol Biol Cell ; 9(11): 3107-18, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9802900

RESUMO

We have shown previously that interleukin-4 (IL-4) protects TS1alphabeta cells from apoptosis, but very little is known about the mechanism by which IL-4 exerts this effect. We found that Akt activity, which is dependent on phosphatidylinositol 3 kinase, is reduced in IL-4-deprived TS1alphabeta cells. Overexpression of wild-type Akt or a constitutively active Akt mutant protects cells from IL-4 deprivation-induced apoptosis. Readdition of IL-4 before the commitment point is able to restore Akt activity. We also show expression and c-Jun N-terminal kinase 2 activation after IL-4 deprivation. Overexpression of the constitutively activated Akt mutant in IL-4-deprived cells correlates with inhibition of c-Jun N-terminal kinase 2 activity. Finally, TS1alphabeta survival is independent of Bcl-2, Bcl-x, or Bax.


Assuntos
Apoptose , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Interleucina-4/metabolismo , Proteínas Quinases Ativadas por Mitógeno , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/metabolismo , Animais , Linhagem Celular , Ativação Enzimática , Proteínas Quinases JNK Ativadas por Mitógeno , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt , Regulação para Cima
10.
J Med Life ; 10(3): 172-175, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29075346

RESUMO

RATIONALE: RAS-RAF-MEK-ERK pathway has been considered a promising target for anticancer therapy. However, tumor cells may develop resistance against such drugs via hyperactivation of N-Ras, which explains why novel therapeut-ic approaches. In this sense, the Institute Curie- Université Pierre et Marie Curie (Paris 6) designed peptides in order to disturb Ras/Raf interaction which showed pro-apoptotic properties. These peptides were patented as WO2015001045 A2 (PCT/EP2014/064243)5. OBJECTIVE: In order to check the anti-tumoral action of WO2015001045 A2 peptides in a very aggressive BALB/c mice spontaneous leukemia called LB, we performed the present study. METHOD & RESULTS: 50 BALB/c mice inoculated with 106 LB tumor cells were randomly assigned either to control (placebo) or treatment group (that daily received 3 mg of peptide per kg of mice) during 30 days. By day 15 only 24% of the control group was alive vs. 100% of the treatment group. The average survival in treated group was 20,27 days while in control group the mean survival was 15,48 days. Either bone marrow, spleen or axillary nodes demonstrated a higher level of malignant T cell presence compare with treated group (89,78% ; 95,64% & 77,68% versus 72,45%, 80,23% & 63.44% respectively for each organ inspected. DISCUSSION: Our study demonstrated an improvement in survival curves in mice model affected by spontaneous T lymphoid leukemia when peptides WO2015001045 A2 were used. These peptides might be a valid option to become part of the therapeutic armory for malignant lymphoproliferative diseases control.


Assuntos
Leucemia de Células T/tratamento farmacológico , Peptídeos/uso terapêutico , Proteínas Proto-Oncogênicas c-raf/metabolismo , Transdução de Sinais , Proteínas ras/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Humanos , Leucemia de Células T/patologia , Camundongos Endogâmicos BALB C , Peptídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida
12.
Oncogene ; 18(35): 4930-9, 1999 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-10490827

RESUMO

IL-2 deprivation triggers apoptosis in the murine T cell line TS1alphabeta, a process that can be blocked by overexpression of Bcl-2. Here we show that Bcl-2 and Ras proteins interact in mitochondria from TS1alphabeta cells in the presence or absence of IL-2, as evidenced by co-immunoprecipitation. All three Ras proteins, K-, N- and H-Ras, interact with Bcl-2; however, their mitochondrial localization is differentially regulated in IL-2-supplemented or -deprived cells. K-Ras is found in mitochondria only in IL-2-supplemented cells, whereas H-Ras is observed in mitochondria only after IL-2 withdrawal. N-Ras is detected in mitochondria under both experimental conditions. Bcl-2 transfection partially restored K- and N-Ras association with mitochondria in IL-2-deprived cells and rendered H-Ras association independent of IL-2 withdrawal. Inhibitors of Ras posttranslational processing did not alter the IL-2-induced differential pattern of mitochondrial localization. The processed forms of K- and N-Ras associated with mitochondria, although unprocessed H-Ras was also detected in mitochondria from mevastatin-treated cells. These results evidence a distinct behavior among the three Ras proteins in TS1alphabeta cells, depending on IL-2 supply, and suggest homologue-specific roles for Ras proteins in IL-2-dependent events.


Assuntos
Apoptose , Interleucina-2/farmacologia , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Animais , Apoptose/efeitos dos fármacos , Transporte Biológico/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Humanos , Lovastatina/análogos & derivados , Lovastatina/farmacologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Oligopeptídeos/farmacologia , Testes de Precipitina , Ligação Proteica , Prenilação de Proteína/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Fatores de Tempo , Transfecção
13.
Oncogene ; 17(10): 1235-43, 1998 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-9771966

RESUMO

The murine TS1alphabeta T cell line expresses the anti-apoptotic protein Bcl-2 upon IL-2 stimulation, whereas IL-4-mediated growth of this cell line proceeds in the absence of Bcl-2 expression. In addition, IL-4 stimulation inhibits Bcl-2 expression and modulates its mRNA level. IL-2-induced DNA binding activity for these transcription factors is sensitive to phosphatidylinositol 3 kinase inhibitor wortmannin and to Rho inhibitor Clostridium difficile toxin B, which inhibit IL-2-induced Bcl-2 expression. NF-AT transcription factor appears to be the most important in the control Bcl-2 expression, since inhibition of the calcium-calmodulin-dependent phosphatase calcineurin, which regulates NF-AT activity, downregulates Bcl-2 expression in IL-2-stimulated cells. Constitutive expression of this phosphatase also upregulates Bcl-2 expression in IL-4-stimulated cells. In addition, a dominant negative NF-AT expression vector downregulates Bcl-2 expression in IL-2-stimulated cells. These results suggest that IL-2 induction of Bcl-2 expression may be directly or indirectly mediated by NF-AT.


Assuntos
Proteínas de Bactérias , Proteínas de Ligação a DNA/metabolismo , Interleucina-2/metabolismo , Interleucina-4/metabolismo , Proteínas Nucleares , Proteínas Proto-Oncogênicas c-bcl-2/genética , Fatores de Transcrição/metabolismo , Androstadienos/farmacologia , Animais , Toxinas Bacterianas/farmacologia , Calcineurina/metabolismo , Inibidores de Calcineurina , Linhagem Celular , Ciclosporina/farmacologia , Proteínas de Ligação a DNA/genética , Regulação para Baixo , Regulação da Expressão Gênica , Interleucina-2/genética , Interleucina-2/farmacologia , Interleucina-4/genética , Interleucina-4/farmacologia , Camundongos , Fatores de Transcrição NFATC , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fator de Transcrição Sp1/metabolismo , Linfócitos T/efeitos dos fármacos , Tacrolimo/farmacologia , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/genética , Ativação Transcricional , Regulação para Cima , Wortmanina
14.
Cell Death Differ ; 6(8): 722-8, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10467345

RESUMO

The importance of Ras proteins as crucial crossroads in cellular signaling pathways has been well established. In spite of the elucidation of the mechanism of RAS activation by growth factors and the delineation of MAP kinase cascades, the overall framework of Ras interactions is far from being complete. Novel regulators of Ras GDP/GTP exchange have been identified that may mediate the activation of Ras in response to changes in intracellular calcium and diacylglycerol. The direct activation of Ras by free radicals such as nitric oxide also suggests potential regulation of Ras function by the cellular redox state. In addition, the array of Ras effectors continues to expand, uncovering links between Ras and other cellular signaling pathways. Ras is emerging as a dual regulator of cellular functions, playing either positive or negative roles in the regulation of proliferation and apoptosis. The signals transmitted by Ras may be modulated by other pathways triggered in parallel, resulting in the final order for proliferation or apoptosis. The diversity of ras-mediated effects may be related in part to differential involvement of Ras homologues in distinct cellular processes. The study of Ras posttranslational modifications has yielded a broad battery of inhibitors that have been envisaged as anti-cancer agents. Although an irreversible modification, Ras isoprenylation appears to be modulated by growth factors and by the activity of the isoprenoid biosynthetic pathway, which may lead to changes in Ras activity.


Assuntos
Transdução de Sinais , Proteínas ras/metabolismo , Animais , Apoptose , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Processamento de Proteína Pós-Traducional
15.
Cell Death Differ ; 6(1): 87-94, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10200552

RESUMO

A variety of environmental stresses, as well as inflammatory cytokines, induce activation of c-Jun N-terminal kinases. We describe here that IL-2 deprivation-induced apoptosis in TS1alphabeta cells does not modify c-Jun protein levels and correlates Bcl-2 downregulation and an increase in JNK1, but not JNK2, activity directly related to the induction of apoptosis. Indeed, downregulation of JNK1 expression using antisense oligonucleotides inhibits apoptosis induced by IL-2 withdrawal. Overexpression of Bcl-2 promotes cell survival and blocks JNK1 activation as well as apoptosis caused by IL-2 deprivation. This suggests that inhibition of the JNK1 signaling pathway may be a mechanism through which Bcl-2 promotes cell survival and prevents apoptosis triggered by growth factor withdrawal.


Assuntos
Apoptose , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Interleucina-2/deficiência , Proteínas Quinases Ativadas por Mitógeno , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Linfócitos T/metabolismo , Animais , Linhagem Celular , Regulação para Baixo , Ativação Enzimática , Citometria de Fluxo , Regulação da Expressão Gênica , Proteínas Quinases JNK Ativadas por Mitógeno , Camundongos , Proteína Quinase 9 Ativada por Mitógeno , Oligonucleotídeos Antissenso/farmacologia , Proteínas Quinases/metabolismo , Transdução de Sinais
16.
Crit Rev Immunol ; 18(3): 185-220, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9637410

RESUMO

In this review we discuss several molecules that are attractive candidates as transducing molecules involved in signaling processes. IL-2 receptor signaling is a complex process involving a large number of molecules: Ras, Rho, PI3 kinase, PKC, Akt, transcription factors NF-AT, and NF-kappaB and some target genes such as bcl-2, c-myc, c-jun and c-fos. Ras and Rho have been defined as dual molecules because Ras- and Rho-initiated signals can either promote or inhibit apoptosis. Several studies have contributed to the delineation of a signaling pathway structured in three independent channels designated channels 1, 2, and 3. These three channels serve as major landmarks: Lck-c-fos/c-jun (channel 1), Syk-myc (channel 2), and a pathway leading to actin organization/bcl-2 expression (channel 3). The detailed hierarchical organization of these three channels is presented throughout the review and the model is depicted in the figure.


Assuntos
Interleucina-2/fisiologia , Transdução de Sinais , Animais , Humanos
17.
Mol Immunol ; 29(1): 119-30, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1370571

RESUMO

We have isolated and characterized 8 mAb against human rIL-2. All recognize nonglycosylated rIL-2 in liquid phase with similar affinities (Kd approximately 1 nM). Based on the epitopes of the IL-2 molecule that they recognize and their pattern of reactivity against glycosylated and non-glycosylated IL-2, they have been classified into four groups. The first group of anti-IL-2 mAb (2C4, 19B11 and 12C2) inhibits IL-2 binding to p70 IL-2R, while the second one (16F11, 18E1 and 2A4) prevents its binding to p55 IL-2R. These two groups neutralize IL-2 activity in a T cell proliferation assay equally well, due to their similar inhibition of IL-2 binding to high affinity IL-2R. Two mAb, 3H9 and 17F4, recognize separate epitopes on IL-2 molecule, are poor inhibitors of IL-2 binding, and they are inefficient in the neutralization of its biological activity; they have been assigned to the third and fourth groups, respectively. These results show that mAb from the first and second group recognize two epitopes of the human IL-2 molecule which probably overlap the p70 IL-2R and p55 IL-2R binding sites, respectively. In addition, these areas together form the high affinity IL-2R binding site. The two mAb from the third and fourth group recognized epitopes of IL-2 not directly involved in IL-2 binding to its receptor. All eight mAb anti-human IL-2 recognize murine IL-2 and with the exception of one, 17F4 mAb are also able to neutralize it in a T cell proliferation assay. The relationship between the structure and the function of the IL-2 molecule is discussed.


Assuntos
Anticorpos Monoclonais/imunologia , Interleucina-2/imunologia , Animais , Especificidade de Anticorpos , Células Cultivadas , Epitopos , Glicosilação , Humanos , Técnicas In Vitro , Interleucina-2/química , Interleucina-2/metabolismo , Ativação Linfocitária , Camundongos , Receptores de Interleucina-2/metabolismo , Proteínas Recombinantes/imunologia , Especificidade da Espécie
18.
Gene ; 79(1): 47-58, 1989 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-2550329

RESUMO

Phosphate strongly repressed the formation of p-aminobenzoic acid (PABA) synthase, an enzyme involved in candicidin biosynthesis. Expression in Streptomyces lividans of the pabS gene (encoding PABA synthase) of Streptomyces griseus is repressed by phosphate at concentrations above 0.1 mM. However, expression of the pabS gene in Escherichia coli is not regulated by phosphate. Phosphate control of the expression of the pabS gene was observed in all plasmids containing the original 4.5-kb BamHI fragment, whereas no phosphate regulation was found when an upstream 1-kb fragment that carries the pabS promoter was deleted. Using the promoter-probe plasmid pIJ424, a '114-bp' promoter was cloned. Expression of the promoterless kanamycin phosphotransferase gene when fused to the '114-bp' promoter was strongly reduced by phosphate (90% at 5 mM concentration). The '114-bp' promoter has been sequenced and the first transcribed nucleotide identified by S1 mapping. The '114-bp' fragment is A + T-rich (54%), as compared to the Streptomyces genome (70-73% GC). The presence of a phosphate control sequence (pcs) in the upstream region of the pabS gene is proposed.


Assuntos
Antifúngicos/biossíntese , Candicidina/biossíntese , Clonagem Molecular , Fosfatos/fisiologia , Regiões Promotoras Genéticas , Sequência de Bases , DNA Bacteriano/isolamento & purificação , Escherichia coli/genética , Genes , Canamicina Quinase , Dados de Sequência Molecular , Fosfotransferases/genética , Fosfotransferases/metabolismo , Plasmídeos , Mapeamento por Restrição , Streptomyces griseus/genética , Transaminases/genética , Transcrição Gênica , Transformação Bacteriana
19.
Front Biosci ; 2: d49-60, 1997 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9159211

RESUMO

The NF-kappaB/Rel/IkappaB family of transcription factors regulates a number of genes involved in a wide variety of biological processes. The activation of p53, c-myc and Ras genes suggests a role for NF-kappaB in cell proliferation; NF-kappaB is also important in immune and inflammatory responses. By virtue of its role in apoptosis, NF-kappaB participates in the thymus as well as in embryonic development. The NF-kappaB family of transcription factors is also involved in viral transcription, transformation and in the development of some types of human cancers. Given the pivotal role of NF-kappaB, clarification is needed of the mechanisms through which its deregulation contributes to disease. Several aspects of NF-kappaB regulation, such as phosphatase involvement, the mechanism of IkappaB ubiquitination and the regulation of nuclear translocation, remain obscure. Here, we review and discuss the function of NF-kappaB activation in IL-2-stimulation and in apoptosis induced by IL-2 deprivation in T cells.


Assuntos
Apoptose/efeitos dos fármacos , Interleucina-2/farmacologia , NF-kappa B/fisiologia , Linfócitos T/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Humanos , Proteínas I-kappa B/metabolismo , Interleucina-2/metabolismo , Modelos Biológicos , NF-kappa B/metabolismo , Receptores de Interleucina-2/metabolismo , Transdução de Sinais , Linfócitos T/citologia , Linfócitos T/metabolismo
20.
Pancreas ; 11(2): 165-72, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7479674

RESUMO

The effects of chronic administration of hydrocortisone (10 mg/kg/day) on the development and evolution of acute pancreatitis induced by supramaximal stimulation with cerulein were examined in the rat. In these circumstances the potentially therapeutic effect of L-364,718, a CCK-receptor antagonist, was assayed. Administration of hydrocortisone over 7 days did not increase the severity of edematous acute pancreatitis induced by cerulein, since the reduction in pancreatic secretion, the hyperamylasemia and the increase in the levels of hematocrit and fluid in the pancreatic tissue were similar in rats with acute pancreatitis treated and untreated with hydrocortisone previously. When hydrocortisone was administered chronically, before administration of supramaximal doses of cerulein, a spontaneous regression of acute pancreatitis occurred. However, when hydrocortisone administration was continued after inducing pancreatitis, pancreatic recovery was prevented, observing a significantly depressed acinar secretion and elevated values of hematocrit and tissue fluid (edema). L-364,718 administration proved to be detrimental in the evolution of edematous acute pancreatitis when the rats had been treated chronically with hydrocortisone because the blockade exerted on secretion prevented the draining of enzymes stored in excess by hydrocortisone administration.


Assuntos
Ceruletídeo , Hidrocortisona/farmacologia , Pancreatite/induzido quimicamente , Doença Aguda , Amilases/sangue , Animais , Benzodiazepinonas/uso terapêutico , Devazepida , Hematócrito , Hidrocortisona/administração & dosagem , Masculino , Pâncreas/efeitos dos fármacos , Pâncreas/fisiopatologia , Suco Pancreático/metabolismo , Pancreatite/fisiopatologia , Pancreatite/prevenção & controle , Ratos , Ratos Wistar , Receptores da Colecistocinina/antagonistas & inibidores
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