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1.
J Nutr Health Aging ; 20(8): 878-888, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27709238

RESUMO

BACKGROUND: The estimation of the risk of poor tolerance and overdose of antineoplastic agents protocols represents a major challenge in oncology, particularly in older patients. We hypothesize that age-related modifications of body composition (i.e. increased fat mass and decreased lean mass) may significantly affect tolerance to chemotherapy. METHOD: We conducted a systematic review for the last 25 years (between 1990 and 2015), using US National library of Medicine Medline electronic bibliographic database and Embase database of cohorts or clinical trials exploring (i) the interactions of body composition (assessed by Dual X-ray Absorptiometry, Bioelectrical Impedance Analyses, or Computerized Tomography) with pharmacokinetics parameters, (ii) the tolerance to chemotherapy, and (iii) the consequences of chemotherapies or targeted therapies on body composition. RESULTS: Our search identified 1504 articles. After a selection (using pre-established criteria) on titles and abstract, 24 original articles were selected with 3 domains of interest: impact of body composition on pharmacokinetics (7 articles), relationship between body composition and chemotoxicity (14 articles), and effect of anti-cancer chemotherapy on body composition (11 articles). The selected studies suggested that pharmacokinetic was influenced by lean mass, that lower lean mass could be correlated with toxicity, and that sarcopenic patients experienced more toxicities that non-sarcopenic patients. Regarding fat mass, results were less conclusive. No studies specifically explored the topic of body composition in older cancer patients. CONCLUSIONS: Plausible pathophysiological pathways linking body composition, toxicity, and pharmacokinetics are sustained by the actual review. However, despite the growing number of older cancer patients, our review highlighted the lack of specific studies in the field of anti-neoplastic agents toxicity regarding body composition conducted in elderly.


Assuntos
Antineoplásicos/uso terapêutico , Composição Corporal/fisiologia , Neoplasias/tratamento farmacológico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
2.
Rev Med Interne ; 37(12): 827-833, 2016 Dec.
Artigo em Francês | MEDLINE | ID: mdl-27639909

RESUMO

Liver abscess is a rare and severe infection. Incidence increases because of aging of population, advances in liver and biliary surgery including liver transplantation, and immunodeficiency factors. Diagnosis depends mainly on imaging and needle aspiration for microbiological identification. Treatment is based on antibiotics, percutaneous or surgical drainage, and control of the primary source.


Assuntos
Antibacterianos/uso terapêutico , Abscesso Hepático/diagnóstico , Fígado/microbiologia , Biópsia por Agulha , Feminino , Humanos , Abscesso Hepático/terapia , Masculino
3.
Med Mal Infect ; 44(11-12): 530-4, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25311839

RESUMO

OBJECTIVE: We wanted to describe the clinical features associated with urinalysis positive for ESBL-producing Escherichia coli and their impact on antibiotic use. METHODS: We performed a prospective observational study in 13 French hospitals of the Paris area for 3 consecutive months. We included all patients with urine cultures positive for ESBL-producing E. coli. RESULTS: One hundred and seventeen of the 218 patients (54%) presented with asymptomatic bacteriuria, 31 (14%) with cystitis, and 70 (32%) with a parenchymal infection. Nineteen patients with asymptomatic bacteriuria (16%) received antibiotics. Forty-one with parenchymal infections (59%) received a carbapenem. A carbapenem alternative could have been used in every patient treated with a carbapenem, according to antibiotic susceptibility testing results. CONCLUSIONS: Urinary tract infections accounted for 46% of E. coli ESBL positive urinalysis. Fifty percent of parenchymal infections were treated with a carbapenem.


Assuntos
Antibacterianos/uso terapêutico , Infecções por Escherichia coli/urina , Escherichia coli/isolamento & purificação , Prescrição Inadequada/estatística & dados numéricos , Urina/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/metabolismo , Bacteriúria/tratamento farmacológico , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/microbiologia , Criança , Pré-Escolar , Infecção Hospitalar/tratamento farmacológico , Escherichia coli/enzimologia , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Paris , Estudos Prospectivos , Fatores de Risco , Especificidade por Substrato , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia , Adulto Jovem , Resistência beta-Lactâmica , beta-Lactamases/metabolismo
4.
Cell Death Dis ; 4: e662, 2013 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-23744362

RESUMO

Osmotic changes occur in many tissues and profoundly influence cell function. Herein, we investigated the effect of hyperosmotic stress on retinal pigmented epithelial (RPE) cells using a microarray approach. Upon 4-h exposure to 100 mM NaCl or 200 mM sucrose, 79 genes were downregulated and 72 upregulated. Three gene ontology categories were significantly modulated: cell proliferation, transcription from RNA polymerase II promoter and response to abiotic stimulus. Fluorescent-activated cell sorting analysis further demonstrated that owing to hyperosmotic stimulation for 24 h, cell count and cell proliferation, as well as the percentage of cells in G0/G1 and S phases were significantly decreased, whereas the percentage of cells in G2/M phases increased, and apoptosis and necrosis remained unaffected. Accordingly, hyperosmotic conditions induced a decrease of cyclin B1 and D1 expression, and an activation of the p38 mitogen-activated protein kinase. In conclusion, our results demonstrate that hypertonic conditions profoundly affect RPE cell gene transcription regulating cell proliferation by downregulation cyclin D1 and cyclin B1 protein expression.


Assuntos
Pontos de Checagem do Ciclo Celular , Células Epiteliais/metabolismo , Pressão Osmótica , Epitélio Pigmentado da Retina/citologia , Linhagem Celular , Proliferação de Células , Ontologia Genética , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Fosforilação , Processamento de Proteína Pós-Traducional , Cloreto de Sódio/farmacologia , Estresse Fisiológico , Transcriptoma , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
Rev Med Interne ; 33(9): 519-21, 2012 Sep.
Artigo em Francês | MEDLINE | ID: mdl-22766160

RESUMO

INTRODUCTION: Fever of unknown origin is a common reason for care in internal medicine. The wide variety of possible etiologies makes it difficult to standardize the diagnostic work-up that has to be primarily guided by the interview and physical examination. CASE REPORT: We report a case of prolonged fever having as main characteristics to be intermittent and triggered by efforts. The diagnosis of cerebrospinal fluid shunt infection with Propionibacterium acnes was finally made. In reaching this conclusion, many tests were needed, including renal explorations with biopsy showing an aspect of shunt nephritis. CONCLUSION: Prolonged fever of unknown origin in a patient having prosthetic material should raise the suspicion of prosthesis infection (especially if the fever is associated with efforts).


Assuntos
Derivações do Líquido Cefalorraquidiano/efeitos adversos , Febre/diagnóstico , Febre/etiologia , Infecções por Bactérias Gram-Positivas/diagnóstico , Esforço Físico/fisiologia , Infecções do Sistema Nervoso Central/diagnóstico , Infecções do Sistema Nervoso Central/etiologia , Infecções do Sistema Nervoso Central/microbiologia , Doença Crônica , Diagnóstico Diferencial , Feminino , Febre/microbiologia , Infecções por Bactérias Gram-Positivas/complicações , Humanos , Pessoa de Meia-Idade , Periodicidade , Propionibacterium acnes/isolamento & purificação
6.
Clin Microbiol Infect ; 14(2): 183-6, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18076664

RESUMO

This study investigated the long-term outcome of patients with tuberculosis (TB) as a complication of tumour necrosis factor (TNF)-alpha blocker therapy. All TB cases (n = 21) complicating TNF-alpha blocker therapy from French university hospitals were collated between January 2000 and September 2002. Outcome was assessed via a postal questionnaire during September 2005. The mortality rate after 4 years was 4.8%, and one patient had relapsed and six (29%) patients had recommenced TNF-alpha antagonist treatment, after appropriate anti-TB therapy, without reactivation. These data support the concept that TNF-alpha antagonists can be restarted in TB patients provided that adequate anti-TB treatment has been completed.


Assuntos
Anticorpos Monoclonais/efeitos adversos , Antirreumáticos/efeitos adversos , Artrite Reumatoide/tratamento farmacológico , Tuberculose/induzido quimicamente , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/uso terapêutico , Antirreumáticos/uso terapêutico , Antituberculosos/uso terapêutico , Artrite Reumatoide/complicações , Feminino , Seguimentos , França/epidemiologia , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Infliximab , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Resultado do Tratamento , Tuberculose/tratamento farmacológico , Tuberculose/mortalidade
7.
Rheumatology (Oxford) ; 44(2): 247-50, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15546964

RESUMO

OBJECTIVES: Recently published findings suggested that antineutrophil cytoplasmic antibodies (ANCA), particularly those with a cytoplasmic (C-ANCA) labelling pattern and targeting proteinase 3 (anti-PR3), might be markers of tuberculosis (TB). This is a critical issue, because C-ANCA/anti-PR3 were considered to be a highly specific hallmark of Wegener's granulomatosis or microscopic polyangiitis and because TB may clinically mimic Wegener's granulomatosis. We therefore undertook a study with the aim of investigating further the prevalence and specificity of ANCA in TB. METHODS: We evaluated serum samples from 67 patients diagnosed with culture-proven TB and 10 previously untested control samples from patients known to be ANCA positive (four Wegener's granulomatosis and two microscopic polyangiitides) or negative. All 77 sera were screened for ANCA using commercially available indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) for anti-PR3 and antimyeloperoxidase (MPO). IIF-positive and anti-PR3- and anti-MPO-negative sera were also tested for bactericidal/permeability-increasing protein, lactoferrin, elastase and cathepsin G specificities with commercially available ELISA. RESULTS: IIF detected ANCA in seven (10%) of the TB sera, including three C-ANCA and four atypical perinuclear-labelling ANCA. Only one IIF-negative specimen was anti-PR3 positive in ELISA. ANCA testing of the control sera yielded IIF and ELISA results concordant with previous findings, except for one borderline ELISA. CONCLUSION: Our results indicate that TB is associated with low ANCA seroprevalence and poor specificity, with no test serum showing combined C-ANCA/anti-PR3 activity. In a clinical setting of Wegener's granulomatosis/TB mimicry, such combined reactivity would seem to be more suggestive of Wegener's granulomatosis.


Assuntos
Anticorpos Anticitoplasma de Neutrófilos/sangue , Tuberculose/imunologia , Adulto , Especificidade de Anticorpos , Comorbidade , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Imunofluorescência/métodos , Humanos , Masculino , Paris/epidemiologia , Peroxidase/imunologia , Estudos Soroepidemiológicos , Tuberculose/sangue , Tuberculose/epidemiologia
9.
Endocrinology ; 142(7): 2760-7, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11415994

RESUMO

A model has been proposed in which, in the absence of TSH, the extracellular domain of the TSH receptor would exert a silencing effect on the serpentine domain involved in activation of the G(alpha)(s) protein. Mutation of S281 in the ectodomain is supposed to release this constraint, thereby causing receptor activation. This defines S281 and its neighbors as a segment important in intramolecular signal transduction. The functional importance of this segment was explored by site-directed mutagenesis experiments involving S281, as well as the two cysteine residues (C283, C284) present immediately downstream. S281 was mutated to N, T, G, and A in this study, and the functional characteristics of the mutants were compared. We found that S281N, S281T, and S281G display stronger constitutive activity than S281A mutant, suggesting that increase in constitutive activity is related to the extent of disruption of the local structure of the ectodomain. C283 and C284, the two consecutive cysteines that are highly conserved in glycoprotein hormone receptors, were mutated to serine, either alone (S281HSC or S281HCS) or in combination (S281HSS) and were studied in two different TSH receptor backgrounds. The mutated cysteine ectodomains were either linked to a glycosylphosphatidylinositol anchor or the serpentine domain of the wild-type holoreceptor. Glycosylphosphatidylinositol-anchored ectodomain receptors showed good cell surface expression in CHO cells, but only S281HCS was able to bind TSH specifically, illustrating the importance of C283, or the putative disulphide bond, in maintaining the conformation of the ligand binding site. In contrast, cysteine mutants on an extracellular domain-holoreceptor background displayed severely impaired membrane targeting and were poorly expressed in COS cells. However, basal cAMP production, normalized to expression at the plasma membrane, indicated significant increase in constitutive activity of all three mutants, compared with the wild-type receptor. Altogether, these findings support a model in which the ectodomain would act as a silencer of the basal activity of the serpentine portion of the receptor.


Assuntos
Mutação/fisiologia , Receptores da Tireotropina/genética , Tireotropina/metabolismo , Sequência de Aminoácidos , Animais , Células COS , Sequência Conservada , Glicosilfosfatidilinositóis/genética , Técnicas In Vitro , Dados de Sequência Molecular , Mutação/genética , Estrutura Terciária de Proteína/genética , Receptores de Superfície Celular/metabolismo
10.
J Biol Chem ; 276(25): 22991-9, 2001 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-11312274

RESUMO

The thyrotropin (TSH) receptor is an interesting model to study G protein-coupled receptor activation as many point mutations can significantly increase its basal activity. Here, we identified a molecular interaction between Asp(633) in transmembrane helix 6 (TM6) and Asn(674) in TM7 of the TSHr that is crucial to maintain the inactive state through conformational constraint of the Asn. We show that these residues are perfectly conserved in the glycohormone receptor family, except in one case, where they are exchanged, suggesting a direct interaction. Molecular modeling of the TSHr, based on the high resolution structure of rhodopsin, strongly favors this hypothesis. Our approach combining site-directed mutagenesis with molecular modeling shows that mutations disrupting this interaction, like the D633A mutation in TM6, lead to high constitutive activation. The strongly activating N674D (TM7) mutation, which in our modeling breaks the TM6-TM7 link, is reverted to wild type-like behavior by an additional D633N mutation (TM6), which would restore this link. Moreover, we show that the Asn of TM7 (conserved in most G protein-coupled receptors) is mandatory for ligand-induced cAMP accumulation, suggesting an active role of this residue in activation. In the TSHr, the conformation of this Asn residue of TM7 would be constrained, in the inactive state, by its Asp partner in TM6.


Assuntos
Asparagina/metabolismo , Proteínas de Membrana/metabolismo , Receptores da Tireotropina/metabolismo , Animais , Células COS , AMP Cíclico/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Conformação Proteica , Receptores da Tireotropina/química , Receptores da Tireotropina/genética , Homologia de Sequência de Aminoácidos , Tireotropina/farmacologia
11.
Medicine (Baltimore) ; 79(5): 327-37, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11039081

RESUMO

To better define the overall characteristics and risk factors for dying of adult pneumococcal endocarditis (PE) focusing on the echocardiographic diagnosis, the impact of surgery, and emergence of penicillin resistance, the medical and microbiologic charts of adult PE cases observed between 1991 and 1998 in university and general hospitals were reviewed through a nationwide retrospective study in France. Thirty cases of PE (22 men, 8 women; median age, 53 yr; range, 27-87 yr) were collected and validated. Twenty patients (66.7%) had no known predisposing cardiopathy; 4 had a bioprosthetic valve. The primary focus of infection was pneumonia in 10 (33.3%), and meningitis was noted in 12 (40.0%). Half the patients suffered from chronic alcoholism. Echocardiography detected vegetation(s) in 29 cases (96.7%), valvular perforation in 6 (20.0%), and/or valve ring abscess in 4 (13.3%). The most frequent complications were congestive heart failure (n = 19), large arterial emboli (n = 8), and focal abscesses (n = 7). Five strains were penicillin-resistant. Twenty (66.7%) patients underwent valve replacement, 12 of them during the first month. The overall mortality rate was 24.1%. According to a multivariate analysis, the risk factors independently associated with dying were age > or = 65 yr and septic shock, while cardiac surgery was protective (p < 0.01). In conclusion, PE is usually fulminant and causes severe valve damage and embolic complications; its short-term prognosis might be improved by early valve replacement.


Assuntos
Endocardite Bacteriana , Resistência às Penicilinas , Infecções Pneumocócicas , Adulto , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/tratamento farmacológico , Endocardite Bacteriana/epidemiologia , Feminino , Seguimentos , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Pneumocócicas/diagnóstico , Infecções Pneumocócicas/tratamento farmacológico , Infecções Pneumocócicas/epidemiologia , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
12.
Biochem Biophys Res Commun ; 187(2): 919-26, 1992 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-1530647

RESUMO

A human brain hippocampus cDNA library was screened by hybridization with a dog A1 adenosine receptor cDNA probe. Sequencing of the resulting clones identified a 978 residue open reading frame encoding a 326 amino acid polypeptide showing 95.7% similarity with the dog A1 adenosine receptor. Individual clones of stably transfected CHO cells expressing the human A1 receptor were obtained and tested for their response to the A1 agonist CPA [N6-cyclopentyladenosine] in the presence of forskolin. One clone was further characterized with respect to membrane binding of various adenosine agonists and antagonists. The rank order of affinities observed was typical of an A1 adenosine receptor. A Kd value of 2.28 nM was determined using [3H]DPCPX [dipropylcyclopentyl-xanthine], an A1 selective antagonist.


Assuntos
Clonagem Molecular , Receptores Purinérgicos/genética , Adenosina/análogos & derivados , Adenosina/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Células CHO/metabolismo , Colforsina/farmacologia , Cricetinae , DNA/genética , DNA/isolamento & purificação , Sondas de DNA , Cães , Hipocampo/química , Humanos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Receptores Purinérgicos/química , Receptores Purinérgicos/fisiologia , Homologia de Sequência do Ácido Nucleico , Transfecção , Xantinas/metabolismo
13.
EMBO J ; 10(7): 1677-82, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1646713

RESUMO

The extensive amino acid sequence conservation among G protein-coupled receptors has been exploited to clone new members of this large family by homology screening or by PCR. Out of four such receptor cDNAs we cloned recently, RDC7 corresponds to a relatively abundant transcript in the brain cortex, the thyroid follicular cell and the testis. We have now identified RDC7 as an A1 adenosine receptor. The A1 agonist CPA [N6-cyclopentyladenosine] decreased by 80% cAMP accumulation in forskolin-stimulated CHO cells stably transfected with RDC7. Specific binding of another A1 adenosine agonist, [3H]CHA [N6-cyclohexyladenosine], was demonstrated on membranes from Cos cells transfected with a pSVL construct harbouring the RDC7 cDNA insert. The binding characteristics were similar to those of the natural brain A1 receptor. The recombinant and the natural receptors behaved also in the same way in displacement experiments involving a series of A1 adenosine agonists. The binding characteristics of RDC7 were compared to those of RDC8, another orphan receptor recently identified as an A2 adenosine receptor. The two molecular species RDC7 and RDC8 correspond clearly to the A1 and A2 receptor entities defined hitherto on a purely pharmacological basis.


Assuntos
DNA/isolamento & purificação , Proteínas de Ligação ao GTP/genética , Receptores de Superfície Celular/genética , Receptores Purinérgicos P1 , Receptores Purinérgicos/genética , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular , Colforsina/farmacologia , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Cães , Proteínas de Ligação ao GTP/metabolismo , Masculino , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Testículo/efeitos dos fármacos , Testículo/metabolismo , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Distribuição Tecidual
16.
Horm Metab Res Suppl ; 23: 38-43, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2170261

RESUMO

The production of the thyroid hormones by the thyroid tissue is regulated by thyrotropin (TSH). TSH, through cAMP, enhances all steps of T3 and T4 synthesis, among which transcription of the genes encoding the precursor protein, thyroglobulin (TG) and the enzyme responsible for the iodination and coupling mechanisms, thyroperoxidase (TPO). Run-on transcription assays show that the kinetics of TG gene transcriptional activation by cAMP is slow (8 to 16 hours) in dog thyrocytes in primary culture, while it is rapid (1 hour) in dog thyroid slices. Activation is sensitive to cycloheximide, reflecting the need for ongoing protein synthesis. In contrast, stimulation of TPO gene transcription is rapid in both experimental systems and is not inhibited in the presence of cycloheximide. It is concluded that different regulatory mechanisms are implicated in the control of Tg and TPO gene transcription by cAMP. However, the stimulation of TG and TPO gene transcription are equally suppressed by inhibition of cAMP-dependent protein kinase, which suggests that both regulatory mechanisms involve protein phosphorylation.


Assuntos
Colforsina/farmacologia , AMP Cíclico/fisiologia , Genes , Iodeto Peroxidase/genética , Tireoglobulina/genética , Glândula Tireoide/metabolismo , Transcrição Gênica , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Células Cultivadas , Cicloeximida/farmacologia , Sondas de DNA , Cães , Genes/efeitos dos fármacos , Humanos , Técnicas In Vitro , Glândula Tireoide/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos
17.
Science ; 246(4937): 1620-2, 1989 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-2556796

RESUMO

The pituitary hormone thyrotropin, or thyroid-stimulating hormone (TSH), is the main physiological agent that regulates the thyroid gland. The thyrotropin receptor (TSHR) was cloned by selective amplification with the polymerase chain reaction of DNA segments presenting sequence similarity with genes for G protein-coupled receptors. Out of 11 new putative receptor clones obtained from genomic DNA, one had sequence characteristics different from all the others. Although this clone did not hybridize to thyroid transcripts, screening of a dog thyroid complementary DNA (cDNA) library at moderate stringency identified a cDNA encoding a 4.9-kilobase thyroid-specific transcript. The polypeptide encoded by this thyroid-specific transcript consisted of a 398-amino acid residue amino-terminal segment, constituting a putative extracellular domain, connected to a 346-residue carboxyl-terminal domain that contained seven putative transmembrane segments. Expression of the cDNA conferred TSH responsiveness to Xenopus oocytes and Y1 cells and a TSH binding phenotype to COS cells. The TSHR and the receptor for luteinizing hormone-choriogonadotropin constitute a subfamily of G protein-coupled receptors with distinct sequence characteristics.


Assuntos
Clonagem Molecular , Genes , Receptores da Tireotropina/genética , Sequência de Aminoácidos , Animais , Northern Blotting , Linhagem Celular , AMP Cíclico , Cães , Feminino , Dados de Sequência Molecular , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Especificidade de Órgãos , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , Tireotropina/farmacologia , Transcrição Gênica , Xenopus
18.
Mol Endocrinol ; 3(12): 2110-8, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2560810

RESUMO

The expression of the genes coding for thyroglobulin (TG), and thyroperoxidase (TPO), are regulated by TSH. These effects are mediated by cAMP as they are reproduced by forskolin. In vitro run-on transcription assays performed on nuclei isolated from dog thyrocytes in culture or from dog thyroid slices, indicate that the forskolin-induced transcriptional stimulation of TG and TPO genes are very different. For the TG gene, the kinetics of transcriptional activation vary according to the experimental model: it is rapid (1 h) in thyroid slices and slow (8 h) in primary cultures. In contrast, TPO induction is rapid in both cases. In primary cultures, insulin is responsible for the basal level and for a part of forskolin-induced TG transcription, whereas TPO transcription is not affected by insulin. The forskolin-induced increase of TG transcription requires ongoing protein synthesis, as it is blocked by cycloheximide. TPO gene transcription is unaffected by cycloheximide. Taken together with previous data on the two genes, our results suggest that while TPO regulation corresponds to the classical model of genes in which the promoter is regulated directly via cAMP regulatory elements, TG gene regulation involves the synthesis of an intermediary, rapid turnover trans-acting protein.


Assuntos
AMP Cíclico/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Iodeto Peroxidase/genética , Tireoglobulina/genética , Glândula Tireoide/metabolismo , Animais , Células Cultivadas , Colforsina/farmacologia , Cicloeximida/farmacologia , Cães , Insulina/farmacologia , Cinética , RNA Nuclear/genética , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/enzimologia
19.
Biochem Biophys Res Commun ; 165(3): 1250-5, 1989 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-2610690

RESUMO

A human thyroid cDNA library was screened by hybridization with a dog thyrotropin receptor (TSHr) cDNA. Sequencing of the resulting clones identified a 2292 residue open reading frame encoding a 744 amino acid mature polypeptide presenting 90.3% similarity with the dog TSHr. Two major transcripts (4.6 and 4.4 kilobases) were identified in the human thyroid which suggests that alternative splicing could generate multiple forms of human TSHr. Transfection of the coding sequence in COS-7 cells conferred to a membrane preparation of these cells the ability to bind specifically TSH. TSH binding was completely displaced by immunoglobulin preparations from patients with idiopathic myxoedema.


Assuntos
Autoanticorpos/metabolismo , Clonagem Molecular , Receptores da Tireotropina/genética , Sequência de Aminoácidos , Linhagem Celular , DNA/genética , DNA/isolamento & purificação , Sondas de DNA , Doença de Graves/imunologia , Humanos , Dados de Sequência Molecular , Mixedema/imunologia , Hibridização de Ácido Nucleico , Splicing de RNA , Receptores da Tireotropina/imunologia , Receptores da Tireotropina/metabolismo , Tireotropina/metabolismo , Transfecção
20.
Eur J Biochem ; 183(3): 699-708, 1989 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-2550222

RESUMO

The role of the two different isozymes of the cAMP-dependent protein kinase is still unclear. We have investigated the potential roles for each isozyme in dog thyroid cells, a model in which the function, expression of differentiation and proliferation are positively regulated by thyrotropin acting through cyclic AMP. The dog thyroid contains both type I and type II cAMP-dependent protein kinases. These isozymes were selectively activated in vitro by type-I-directed and type-II-directed analog pairs. In thyroid slices, both type-I directed and type II-directed analog pairs synergistically activated thyroid hormone synthesis, as measured by incorporation of 131I into proteins and thyroid hormone secretion as determined by the release of butanol-extractable 131I. In primary cultures of dog thyroid cells both isozyme-directed analog pairs synergistically enhanced iodide trapping, a marker of differentiation, and DNA synthesis, as measured by the percentage of cells incorporating [3H]thymidine into their nuclei. However, DNA synthesis was more sensitive to type-I-directed pairs. The results demonstrate that both cAMP-dependent protein kinase isozymes can mediate the action of cAMP on function, differentiation expression and cell proliferation in dog thyroid cells.


Assuntos
AMP Cíclico/análogos & derivados , AMP Cíclico/farmacologia , Isoenzimas/metabolismo , Proteínas Quinases/metabolismo , Glândula Tireoide/citologia , Tireotropina/farmacologia , Animais , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Replicação do DNA/efeitos dos fármacos , Cães , Sinergismo Farmacológico , Ativação Enzimática , Técnicas In Vitro , Iodetos/metabolismo , Relação Estrutura-Atividade , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo
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