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1.
Int Ophthalmol ; 39(1): 105-109, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29274019

RESUMO

PURPOSE: To validate the hypothesis that BAK induces low-grade inflammation in the anterior chamber, we designed a study to investigate whether switching from BAK-preserved to preservative-free latanoprost in patients with primary open-angle glaucoma (POAG) would reduce the flare levels. PATIENTS: Forty-one eyes of twenty-two patients with primary open-angle glaucoma treated with BAK-preserved latanoprost for at least 6 months as monotherapy were included. Exclusion criteria included any use of topical eye drops other than latanoprost, pseudoexfoliation and pigment dispersion glaucoma, wearing of contact lenses and intraocular surgery in the past year. METHODS: At the start of the study, we measured baseline flare values. We then switched all patients to preservative-free latanoprost. After 1, 2, and 3 months, a routine ophthalmological examination was performed and flare measurement repeated. RESULTS: Thirty-three eyes were followed up throughout the entire 3-month period. One month after the switch to preservative-free latanoprost, a statistically significant mean drop in flare of - 0.96 ph/ms (P = 0.025) was observed. Mean flare decreased further by - 1.31 ph/ms (P = 0.0027) after 2 months and by - 1.25 ph/ms (P = 0.0041) after 3 months. CONCLUSION: The switch from BAK-preserved to preservative-free latanoprost induced a statistically significant reduction in mean flare value. Whereas our previous study showed an increase in flare when initiating treatment with BAK-preserved eye drops, this study shows a decrease in flare upon cessation of BAK-preserved drugs. The combined evidence from the two studies strongly suggests that in humans BAK exerts its effects not only on the ocular surface, but also at the level of the anterior chamber.


Assuntos
Câmara Anterior/diagnóstico por imagem , Compostos de Benzalcônio/uso terapêutico , Substituição de Medicamentos/métodos , Glaucoma de Ângulo Aberto/tratamento farmacológico , Pressão Intraocular/efeitos dos fármacos , Latanoprosta/administração & dosagem , Idoso , Anti-Hipertensivos/administração & dosagem , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Soluções Oftálmicas/administração & dosagem , Conservantes Farmacêuticos , Estudos Prospectivos
2.
Genes Immun ; 16(2): 142-50, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25569266

RESUMO

A classic T-cell phenotype in systemic lupus erythematosus (SLE) is the downregulation and replacement of the CD3ζ chain that alters T-cell receptor signaling. However, genetic associations with SLE in the human CD247 locus that encodes CD3ζ are not well established and require replication in independent cohorts. Our aim was therefore to examine, localize and validate CD247-SLE association in a large multiethnic population. We typed 44 contiguous CD247 single-nucleotide polymorphisms (SNPs) in 8922 SLE patients and 8077 controls from four ethnically distinct populations. The strongest associations were found in the Asian population (11 SNPs in intron 1, 4.99 × 10(-4) < P < 4.15 × 10(-2)), where we further identified a five-marker haplotype (rs12141731-rs2949655-rs16859085-rs12144621-rs858554; G-G-A-G-A; P(hap) = 2.12 × 10(-5)) that exceeded the most associated single SNP rs858554 (minor allele frequency in controls = 13%; P = 4.99 × 10(-4), odds ratio = 1.32) in significance. Imputation and subsequent association analysis showed evidence of association (P < 0.05) at 27 additional SNPs within intron 1. Cross-ethnic meta-analysis, assuming an additive genetic model adjusted for population proportions, showed five SNPs with significant P-values (1.40 × 10(-3) < P< 3.97 × 10(-2)), with one (rs704848) remaining significant after Bonferroni correction (P(meta) = 2.66 × 10(-2)). Our study independently confirms and extends the association of SLE with CD247, which is shared by various autoimmune disorders and supports a common T-cell-mediated mechanism.


Assuntos
Complexo CD3/genética , Lúpus Eritematoso Sistêmico/etnologia , Lúpus Eritematoso Sistêmico/genética , Adulto , Povo Asiático/genética , Estudos de Casos e Controles , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Linfócitos T/imunologia , População Branca/genética
3.
Transpl Infect Dis ; 16(3): 505-10, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24725139

RESUMO

The optimal combination of galactomannan index (GMI) testing for the diagnosis of invasive pulmonary aspergillosis (IPA) remains unclear. For diagnostic approaches that are triggered by clinical signs and symptoms in high-risk patients, institutional variation remains, with some centers routinely relying on only serum GMI or bronchoalveolar lavage (BAL) GMI testing. In addition, use of mold-active agents before diagnosis of IPA is becoming increasingly common, and understanding the effect of these drugs on test yield is important when making time-critical treatment decisions. In a single-center cohort of 210 allogeneic hematopoietic cell transplant recipients, we found that serum and BAL GMI testing contributed independently to IPA diagnosis, supporting the practice of sending both tests simultaneously to ensure a timely diagnosis of IPA. BAL GMI sensitivity was not affected by receipt of mold-active therapy in our cohort.


Assuntos
Líquido da Lavagem Broncoalveolar/química , Aspergilose Pulmonar Invasiva/diagnóstico , Mananas/sangue , Transplante/efeitos adversos , Adolescente , Adulto , Idoso , Aspergillus/isolamento & purificação , Feminino , Galactose/análogos & derivados , Humanos , Aspergilose Pulmonar Invasiva/microbiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
4.
Br J Cancer ; 108(11): 2399-406, 2013 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-23652303

RESUMO

BACKGROUND: Women treated with supradiaphragmatic radiotherapy (sRT) for Hodgkin lymphoma (HL) at young ages have a substantially increased breast cancer risk. Little is known about how menarcheal and reproductive factors modify this risk. METHODS: We examined the effects of menarcheal age, pregnancy, and menopausal age on breast cancer risk following sRT in case-control data from questionnaires completed by 2497 women from a cohort of 5002 treated with sRT for HL at ages <36 during 1956-2003. RESULTS: Two-hundred and sixty women had been diagnosed with breast cancer. Breast cancer risk was significantly increased in patients treated within 6 months of menarche (odds ratio (OR) 5.52, 95% confidence interval (CI) (1.97-15.46)), and increased significantly with proximity of sRT to menarche (Ptrend<0.001). It was greatest when sRT was close to a late menarche, but based on small numbers and needing reexamination elsewhere. Risk was not significantly affected by full-term pregnancies before or after treatment. Risk was significantly reduced by early menopause (OR 0.55, 95% CI (0.35-0.85)), and increased with number of premenopausal years after treatment (Ptrend=0.003). CONCLUSION: In summary, this paper shows for the first time that sRT close to menarche substantially increases breast cancer risk. Careful consideration should be given to follow-up of these women, and to measures that might reduce their future breast cancer risk.


Assuntos
Neoplasias da Mama/epidemiologia , Doença de Hodgkin/radioterapia , Neoplasias Induzidas por Radiação/epidemiologia , Adulto , Fatores Etários , Neoplasias da Mama/etiologia , Estudos de Casos e Controles , Estudos de Coortes , Inglaterra/epidemiologia , Feminino , Humanos , Menarca , Pessoa de Meia-Idade , Neoplasias Induzidas por Radiação/etiologia , Gravidez , História Reprodutiva , País de Gales/epidemiologia
5.
Genes Immun ; 13(3): 232-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22189356

RESUMO

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by autoantibody production and organ damage. Lupus nephritis (LN) is one of the most severe manifestations of SLE. Multiple studies reported associations between renal diseases and variants in the non-muscle myosin heavy chain 9 (MYH9) and the neighboring apolipoprotein L 1 (APOL1) genes. We evaluated 167 variants spanning MYH9 for association with LN in a multiethnic sample. The two previously identified risk variants in APOL1 were also tested for association with LN in European-Americans (EAs) (N = 579) and African-Americans (AAs) (N = 407). Multiple peaks of association exceeding a Bonferroni corrected P-value of P < 2.03 × 10(-3) were observed between LN and MYH9 in EAs (N = 4620), with the most pronounced association at rs2157257 (P = 4.7 × 10(-4), odds ratio (OR) = 1.205). A modest effect with MYH9 was also detected in Gullah (rs8136069, P = 0.0019, OR = 2.304). No association between LN and MYH9 was found in AAs, Asians, Amerindians or Hispanics. This study provides the first investigation of MYH9 in LN in non-Africans and of APOL1 in LN in any population, and presents novel insight into the potential role of MYH9 in LN in EAs.


Assuntos
Apolipoproteínas/genética , Negro ou Afro-Americano/genética , Lipoproteínas HDL/genética , Nefrite Lúpica/etnologia , Nefrite Lúpica/genética , Proteínas Motores Moleculares/genética , Cadeias Pesadas de Miosina/genética , Apolipoproteína L1 , Predisposição Genética para Doença , Humanos , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , População Branca/genética
6.
Genes Immun ; 13(5): 380-7, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22476155

RESUMO

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical manifestations characterized by the development of pathogenic autoantibodies manifesting in inflammation of target organs such as the kidneys, skin and joints. Genome-wide association studies have identified genetic variants in the UBE2L3 region that are associated with SLE in subjects of European and Asian ancestry. UBE2L3 encodes an ubiquitin-conjugating enzyme, UBCH7, involved in cell proliferation and immune function. In this study, we sought to further characterize the genetic association in the region of UBE2L3 and use molecular methods to determine the functional effect of the risk haplotype. We identified significant associations between variants in the region of UBE2L3 and SLE in individuals of European and Asian ancestry that exceeded a Bonferroni-corrected threshold (P<1 × 10(-4)). A single risk haplotype was observed in all associated populations. Individuals harboring the risk haplotype display a significant increase in both UBE2L3 mRNA expression (P=0.0004) and UBCH7 protein expression (P=0.0068). The results suggest that variants carried on the SLE-associated UBE2L3 risk haplotype influence autoimmunity by modulating UBCH7 expression.


Assuntos
Predisposição Genética para Doença , Haplótipos , Lúpus Eritematoso Sistêmico/genética , Enzimas de Conjugação de Ubiquitina/genética , Negro ou Afro-Americano/genética , Alelos , Povo Asiático/genética , Feminino , Hispânico ou Latino/genética , Humanos , Desequilíbrio de Ligação , Lúpus Eritematoso Sistêmico/etnologia , Masculino , Polimorfismo de Nucleotídeo Único , Enzimas de Conjugação de Ubiquitina/metabolismo , População Branca/genética
7.
Genes Immun ; 12(4): 270-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21270825

RESUMO

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disorder with a complex pathogenesis in which genetic, hormonal and environmental factors have a role. Rare mutations in the TREX1 gene, the major mammalian 3'-5' exonuclease, have been reported in sporadic SLE cases. Some of these mutations have also been identified in a rare pediatric neurological condition featuring an inflammatory encephalopathy known as Aicardi-Goutières syndrome (AGS). We sought to investigate the frequency of these mutations in a large multi-ancestral cohort of SLE cases and controls. A total of 40 single-nucleotide polymorphisms (SNPs), including both common and rare variants, across the TREX1 gene, were evaluated in ∼8370 patients with SLE and ∼7490 control subjects. Stringent quality control procedures were applied, and principal components and admixture proportions were calculated to identify outliers for removal from analysis. Population-based case-control association analyses were performed. P-values, false-discovery rate q values, and odds ratios (OR) with 95% confidence intervals (CI) were calculated. The estimated frequency of TREX1 mutations in our lupus cohort was 0.5%. Five heterozygous mutations were detected at the Y305C polymorphism in European lupus cases but none were observed in European controls. Five African cases incurred heterozygous mutations at the E266G polymorphism and, again, none were observed in the African controls. A rare homozygous R114H mutation was identified in one Asian SLE patient, whereas all genotypes at this mutation in previous reports for SLE were heterozygous. Analysis of common TREX1 SNPs (minor allele frequency (MAF)>10%) revealed a relatively common risk haplotype in European SLE patients with neurological manifestations, especially seizures, with a frequency of 58% in lupus cases compared with 45% in normal controls (P=0.0008, OR=1.73, 95% CI=1.25-2.39). Finally, the presence or absence of specific autoantibodies in certain populations produced significant genetic associations. For example, a strong association with anti-nRNP was observed in the European cohort at a coding synonymous variant rs56203834 (P=2.99E-13, OR=5.2, 95% CI=3.18-8.56). Our data confirm and expand previous reports and provide additional support for the involvement of TREX1 in lupus pathogenesis.


Assuntos
Exodesoxirribonucleases/genética , Lúpus Eritematoso Sistêmico/genética , Fosfoproteínas/genética , Estudos de Coortes , Feminino , Haplótipos , Humanos , Lúpus Eritematoso Sistêmico/epidemiologia , Masculino , Mutação , Fenótipo , Polimorfismo de Nucleotídeo Único
8.
Clin Transl Oncol ; 23(10): 2141-2154, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33948920

RESUMO

The relapse rate for children with acute myeloid leukemia is nearly 40% despite aggressive chemotherapy and often stem cell transplant. We sought to understand how environment-induced signaling responses are associated with clinical response to treatment. We previously reported that patients whose AML cells showed low G-CSF-induced STAT3 activation had inferior event-free survival compared to patients with stronger STAT3 responses. Here, we expanded the paradigm to evaluate multiple signaling parameters induced by a more physiological stimulus. We measured STAT3, STAT5 and ERK1/2 responses to G-CSF and to stromal cell-conditioned medium for 113 patients enrolled on COG trials AAML03P1 and AAML0531. Low inducible STAT3 activity was independently associated with inferior event-free survival in multivariate analyses. For inducible STAT5 activity, those with the lowest and highest responses had inferior event-free survival, compared to patients with intermediate STAT5 responses. Using existing RNA-sequencing data, we compared gene expression profiles for patients with low inducible STAT3/5 activation with those for patients with higher inducible STAT3/5 signaling. Genes encoding hematopoietic factors and mitochondrial respiratory chain subunits were overexpressed in the low STAT3/5 response groups, implicating inflammatory and metabolic pathways as potential mechanisms of chemotherapy resistance. We validated the prognostic relevance of individual genes from the low STAT3/5 response signature in a large independent cohort of pediatric AML patients. These findings provide novel insights into interactions between AML cells and the microenvironment that are associated with treatment failure and could be targeted for therapeutic interventions.


Assuntos
Fator Estimulador de Colônias de Granulócitos/farmacologia , Leucemia Mieloide Aguda/genética , Sistema de Sinalização das MAP Quinases , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT5/genética , Transcriptoma , Proteínas Supressoras de Tumor/genética , Adolescente , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Criança , Pré-Escolar , Criopreservação , Meios de Cultivo Condicionados/farmacologia , Resistencia a Medicamentos Antineoplásicos , Feminino , Perfilação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Lactente , Interleucina-13/farmacologia , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/terapia , Masculino , Análise Multivariada , Intervalo Livre de Progressão , Modelos de Riscos Proporcionais , Recidiva , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT5/metabolismo , Análise de Sequência de RNA , Ativação Transcricional , Microambiente Tumoral , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima , Adulto Jovem
9.
Rheumatology (Oxford) ; 47(9): 1335-41, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18650228

RESUMO

OBJECTIVE: Antigen-presenting cells (APC) play critical roles in establishing and maintaining peripheral tolerance. This is accomplished in part via expression of negative co-stimulatory molecules such as programmed death ligand-1 (PD-L1) on tolerogenic APC, such as immature myeloid dendritic cells (mDC). Several studies have strongly linked dysfunction of APC, including mDC, to the pathogenesis of SLE. The objective of this study was to determine whether APC expressed PD-L1 protein at normal levels during active lupus. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated from 19 paediatric patients with SLE and from 17 healthy age-matched controls. PBMC from both cohorts were cultured in the absence of exogenously added stimuli, and leucocyte PD-L1 expression was measured by flow cytometry. RESULTS: Immature mDC and monocytes (Mo) from healthy children expressed little PD-L1 at initial isolation, but spontaneously up-regulated PD-L1 by 24 h. In contrast, both mDC and Mo from patients with active SLE failed to up-regulate PD-L1 over a 5 day time course, expressing this protein only during disease remissions. CONCLUSIONS: These data are the first to link active lupus with reversibly decreased PD-L1 expression on professional APC, suggesting a novel mechanism for loss of peripheral tolerance in SLE.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Antígenos CD/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Adolescente , Adulto , Antígeno B7-H1 , Células Cultivadas , Criança , Células Dendríticas/imunologia , Feminino , Humanos , Masculino , Monócitos/imunologia , Índice de Gravidade de Doença , Regulação para Cima/imunologia
10.
Placenta ; 28(5-6): 378-82, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16934327

RESUMO

Recent advances in placental biology and immunology lead us to propose a novel hypothesis for maternal tolerance of the semi-allogeneic fetus and amelioration of rheumatoid arthritis (RA) during pregnancy. The initial event in this hypothesis is extrusion of placental apoptotic syncytiotrophoblast debris recently identified to contain intracellular fetal HLA Class II molecules, into maternal blood. The second event is uptake of apoptotic syncytiotrophoblast by immature maternal dendritic cells and presentation of fetal HLA class II peptides. In addition to presenting foreign antigens, HLA molecules also present HLA self-peptides. In the setting of the non-inflammatory environment of pregnancy, this process is expected to induce peripheral tolerance of fetal antigens through T cell death, anergy or induction of regulatory T cells in the lymph nodes. This hypothesis suggests a mechanism by which the simultaneous presentation of fetal and self (RA-associated) HLA peptides by tolerogenic dendritic cells during pregnancy may explain the observed amelioration of RA as a secondary benefit of fetal tolerance. After delivery, apoptotic syncytiotrophoblast debris disappears from maternal blood, autoimmunity returns and RA recurs. Thus, during pregnancy maternal immunologic "self" includes fetal HLA Class II as a result of apoptotic syncytiotrophoblast uptake by maternal tolerogenic dendritic cells.


Assuntos
Feto/imunologia , Tolerância Imunológica , Troca Materno-Fetal/imunologia , Gravidez/fisiologia , Artrite Reumatoide/prevenção & controle , Feminino , Antígenos HLA-D/imunologia , Humanos , Gravidez/imunologia , Complicações na Gravidez/prevenção & controle
11.
Placenta ; 28(5-6): 477-81, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17055575

RESUMO

Toll-like receptor 4 (TLR4) mediates lipopolysaccharide (LPS) induced immune responses, which may contribute to preterm labor associated with intraamniotic gram-negative bacterial infections. The study objective was to investigate gestational age and LPS-induced changes in TLR4 subcellular localization within amniotic epithelium, the first line of host defense against intraamniotic bacteria. TLR4 localization in amniotic epithelium was assessed using immunohistochemistry on 24 placentas of different gestational ages: first trimester (n=6), second trimester (n=6), and third trimester (n=12). Immunofluorescence was used to determine TLR4 localization following ex vivo LPS stimulation of amnion from women undergoing cesarean section without labor at term. TLR4 was expressed in the cytoplasm of amniotic epithelium starting at 9weeks with apical polarization by 25weeks gestation. TLR4 localization to the basal membrane was significantly associated with chorioamnionitis (p=0.01). After LPS stimulation, TLR4 was expressed sequentially within the apical membrane, cytoplasm, and finally in the basal cellular compartment. This suggests that TLR4 expression in amniotic epithelium is poised to monitor amniotic fluid for pathogens. TLR4 translocation to the basal membrane may decrease LPS signaling early in an infection, but allow the amniotic epithelium to remain competent to invasive or intracellular bacteria.


Assuntos
Âmnio/metabolismo , Células Epiteliais/metabolismo , Lipopolissacarídeos/farmacologia , Placenta/metabolismo , Receptor 4 Toll-Like/metabolismo , Âmnio/citologia , Âmnio/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Feminino , Humanos , Imuno-Histoquímica , Cinética , Microscopia Confocal , Placenta/citologia , Placenta/efeitos dos fármacos , Gravidez , Transporte Proteico
12.
Mol Cell Biol ; 10(6): 3087-94, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2342469

RESUMO

The pituitary peptide hormone prolactin (Prl) is a potent inducer of Nb2 T lymphoma cell proliferation. To analyze the early genetic response to the mitogenic signals of Prl, a cDNA library was constructed from Nb2 T cells stimulated for 4 h with Prl and the protein synthesis inhibitor cycloheximide. Of 26 distinct clones isolated by differential screening, one clone, designated c25, exhibited extremely rapid but transient kinetics of induction by Prl and superinduction by Prl plus cycloheximide. Run-on transcription analysis indicated that c25 gene transcription was induced greater than 20-fold within 30 to 60 min of Prl stimulation. Surprisingly, DNA sequence analysis of c25 cDNA revealed that this Prl-inducible early-response gene is the rat homolog of the mouse transcription factor interferon-regulatory factor 1 (IRF-1), sharing 91% coding sequence similarity with mouse IRF-1. At the protein level, rat IRF-1 shares 97% and 92% homology with mouse IRF-1 and human IRF-1, respectively, suggesting that this molecule has been functionally conserved throughout evolution. Our studies show that the gene for IRF-1 is an immediate-early gene in Prl-stimulated T cells, which suggests that IRF-1 is a multifunctional molecule. In addition to its role in regulating growth-inhibitory interferon genes, IRF-1 may, therefore, also play a stimulatory role in cell proliferation. The gene for IRF-1 is one of the earliest genes known to be transcriptionally regulated by Prl.


Assuntos
Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Fosfoproteínas , Prolactina/farmacologia , Transcrição Gênica/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Clonagem Molecular , Cicloeximida/farmacologia , DNA de Neoplasias/genética , DNA de Neoplasias/isolamento & purificação , Biblioteca Gênica , Genes , Humanos , Fator Regulador 1 de Interferon , Linfoma , Camundongos , Dados de Sequência Molecular , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , Ratos , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/genética
13.
Sci Rep ; 7(1): 15548, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29138423

RESUMO

The 35-kDa Orange Carotenoid Protein (OCP) is responsible for photoprotection in cyanobacteria. It acts as a light intensity sensor and efficient quencher of phycobilisome excitation. Photoactivation triggers large-scale conformational rearrangements to convert OCP from the orange OCPO state to the red active signaling state, OCPR, as demonstrated by various structural methods. Such rearrangements imply a complete, yet reversible separation of structural domains and translocation of the carotenoid. Recently, dynamic crystallography of OCPO suggested the existence of photocycle intermediates with small-scale rearrangements that may trigger further transitions. In this study, we took advantage of single 7 ns laser pulses to study carotenoid absorption transients in OCP on the time-scale from 100 ns to 10 s, which allowed us to detect a red intermediate state preceding the red signaling state, OCPR. In addition, time-resolved fluorescence spectroscopy and the assignment of carotenoid-induced quenching of different tryptophan residues derived thereof revealed a novel orange intermediate state, which appears during the relaxation of photoactivated OCPR to OCPO. Our results show asynchronous changes between the carotenoid- and protein-associated kinetic components in a refined mechanistic model of the OCP photocycle, but also introduce new kinetic signatures for future studies of OCP photoactivity and photoprotection.


Assuntos
Proteínas de Bactérias/química , Carotenoides/química , Ficobilissomas/química , Synechocystis/química , Proteínas de Bactérias/genética , Carotenoides/efeitos da radiação , Cristalografia por Raios X , Cinética , Lasers , Luz , Modelos Moleculares , Ficobilissomas/efeitos da radiação , Transdução de Sinais/efeitos da radiação , Espectrometria de Fluorescência , Synechocystis/genética
14.
Mol Endocrinol ; 8(3): 345-55, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8015552

RESUMO

The interferon regulatory factor-1 (IRF-1) gene is both an immediate-early G1 phase gene and an S phase gene inducible by PRL in rat Nb2 T lymphocytes. To understand the mechanism by which PRL regulates the biphasic expression of IRF-1, we cloned the rat IRF-1 gene and functionally characterized the IRF-1 promoter. Upon transfection into Nb2 T cells, 1.7 kilobases (kb) of IRF-1 5'-flanking DNA linked to a chloramphenicol acetyl transferase (CAT) reporter gene mediated a 30-fold induction of CAT enzyme activity in response to 24 h of PRL stimulation. Deletion mutants containing 1.3, 0.6, and 0.2 kb 5'-flanking DNA were incrementally less transcriptionally active, although 0.2 kb still mediated a 12-fold induction by PRL. The sequence between -1.7 and -0.2 kb linked to a heterologous thymidine kinase promoter failed to respond to PRL stimulation, suggesting that the activity of upstream PRL response elements may require an interaction with promoter-proximal elements. By assaying CAT enzyme activity across a 24-h PRL induction time course, we were able to assign G1 vs. S phase PRL responses of the IRF-1 gene to different regions of the IRF-1 5'-flanking and promoter DNA. The 0.2-kb IRF-CAT construct was induced by PRL stimulation during the G1 phase of the cell cycle. In contrast, the 1.7-kb IRF-CAT construct was inducible by PRL during both G1 and S phase of the cell cycle. Hence, the PRL-induced biphasic expression of the IRF-1 gene appears to be controlled by separate PRL-responsive elements: elements in the first 0.2 kb of the IRF-1 promoter region act during early activation, and elements between 0.2 and 1.7 kb act in concert with the proximal 0.2-kb region during S phase progression.


Assuntos
Proteínas de Ligação a DNA/genética , Fase G1 , Regulação da Expressão Gênica , Genes env/fisiologia , Fosfoproteínas/genética , Prolactina/genética , Fase S , Animais , Sequência de Bases , Ciclo Celular , Linhagem Celular , Cloranfenicol O-Acetiltransferase/análise , Cloranfenicol O-Acetiltransferase/metabolismo , DNA/análise , DNA/genética , Genes Precoces , Genes Reporter , Genes fos/genética , Genes myc/genética , Humanos , Fator Regulador 1 de Interferon , Camundongos , Dados de Sequência Molecular , Ornitina Descarboxilase/genética , Prolactina/fisiologia , Regiões Promotoras Genéticas/genética , Ratos , Linfócitos T/citologia , Fatores de Transcrição/genética , Transcrição Gênica , Transfecção
15.
Mol Endocrinol ; 6(12): 2236-43, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1491701

RESUMO

PRL induces quiescent Nb2 rat T-lymphoma cells to undergo mitogenesis. Upon PRL stimulation, the transcription factor interferon regulatory factor-1 (IRF-1) is induced as a novel T-cell activation gene in Nb2 cells. Surprisingly, IRF-1 is expressed twice during a single PRL-induced growth cycle: first during the early G1 phase, in an immediate transient peak from 15 min to 2 h, and second during the G1/S phase transition, in a broader peak beginning at 8 h. The unusual biphasic expression of IRF-1 mRNA is accompanied both times by de novo IRF-1 protein synthesis. However, the rate of IRF-1 protein turnover appears to be different in G1 and S phases. IRF-1 protein expressed in G1 exhibits a half-life of about 25 min, whereas in the S phase, the half-life is about 60 min. By washing out PRL at various times during G1, we found a direct correlation among the length of PRL exposure, the second peak of IRF-1 mRNA expression, and DNA synthesis. Our data suggest that PRL and one putative nuclear mediator, IRF-1, may be important in two distinct phases of the cell cycle: first in cell cycle activation, and then in S phase progression.


Assuntos
Proteínas de Ligação a DNA/biossíntese , Regulação da Expressão Gênica/efeitos dos fármacos , Interfase/efeitos dos fármacos , Fosfoproteínas/biossíntese , Prolactina/farmacologia , Fase S/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Fatores de Transcrição/biossíntese , Animais , Divisão Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA de Neoplasias/biossíntese , Proteínas de Ligação a DNA/genética , Fator Regulador 1 de Interferon , Linfoma de Células T , Fosfoproteínas/genética , Ratos , Linfócitos T/metabolismo , Fatores de Transcrição/genética , Células Tumorais Cultivadas
16.
Mol Endocrinol ; 9(4): 513-25, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7659094

RESUMO

Stimulation of quiescent Nb2 T cells by PRL leads to the rapid transcriptional activation of a T cell activation gene, interferon regulatory factor-1 (IRF-1). IRF-1 is induced twice by PRL in a single cell cycle, first during G1 at 30-60 min and again over early S phase at 10-12 h. By nuclear run-on transcription analysis of IRF-1 promoter-chloramphenicol acetyl transferase (CAT) constructs, the -1.7 kilobase (kb) 5'-flanking IRF-1 DNA was shown to contain elements that mediate both G1 and S phase expression. The -200 bp IRF-1 promoter DNA contains elements that respond to G1 PRL stimulation in a protein synthesis independent manner, suggesting the involvement of pre-existing factors. Further promoter deletion analysis delineated a minimal PRL responsive region between -112 and -205 bp. Within this region is a Gamma Interferon Activated Sequence or GAS, consisting of two inverted GAAA motifs (-123/-113), which confers PRL-inducible expression to a reporter gene, suggesting that GAS can function as a PRL responsive element. Further, GAS exhibits binding with nuclear proteins in a PRL-inducible, cell cycle-dependent manner. One of these proteins appears to be related to the emerging family of Signal Transducer and Activator of Transcription or Stat factors. These studies suggest that the GAS site and Stat-like proteins participate in PRL receptor signal transduction to regulate the biphasic expression of the IRF-1 gene in PRL-stimulated T cells.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Interferon gama/farmacologia , Fosfoproteínas/genética , Prolactina/farmacologia , Transativadores/farmacologia , Transcrição Gênica/efeitos dos fármacos , Animais , Sequência de Bases , Proteínas de Ligação a DNA/biossíntese , Fase G1 , Fator Regulador 1 de Interferon , Dados de Sequência Molecular , Fosfoproteínas/biossíntese , Ratos , Sequências Reguladoras de Ácido Nucleico , Fase S , Fator de Transcrição STAT1 , Transdução de Sinais/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo
17.
AIDS ; 5(3): 295-300, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2059369

RESUMO

We present the baseline results of a prospective cohort study on the perinatal transmission of HIV-1 in Kigali, Rwanda. HIV-1-antibody testing was offered to all women of urban origin delivering a live newborn at the maternity ward of the Centre Hospitalier de Kigali from November 1988 to June 1989; 218 newborns of 215 HIV-positive mothers were matched to 218 newborns of 216 HIV-negative mothers. The matching criteria were maternal age and parity. No differences in socioeconomic characteristics were observed between HIV-positive and HIV-negative women. HIV-positive mothers more frequently reported a history of at least one death of a previously born child (P less than 0.01) and a history of abortion (P less than 0.001). Most of the HIV-positive women were asymptomatic, but 72.4% of them had a CD4; CD8 ratio less than 1 versus 10.1% in the HIV-negative group (P less than 0.001). The frequency of signs and symptoms was not statistically different in the two groups, except for a history of herpes zoster or chronic cough, which was more frequent among HIV-positive women. The rates of prematurity, low birth weight, congenital malformations and neonatal mortality were comparable in the two groups. However, infants of HIV-positive mothers had a mean birth weight 130 g lower than the infants of HIV-negative mothers (P less than 0.01). The impact of maternal HIV-1 infection on the infant seems limited during the neonatal period.


Assuntos
Infecções por HIV/epidemiologia , Soroprevalência de HIV , HIV-1 , Mortalidade Infantil , Complicações Infecciosas na Gravidez/epidemiologia , Aborto Espontâneo/complicações , Aborto Espontâneo/epidemiologia , Peso ao Nascer , Estudos de Coortes , Feminino , Infecções por HIV/complicações , Infecções por HIV/congênito , Infecções por HIV/transmissão , Herpes Zoster/complicações , Herpes Zoster/epidemiologia , Humanos , Recém-Nascido , Masculino , Troca Materno-Fetal , Gravidez , Estudos Prospectivos , Ruanda/epidemiologia , Fatores Socioeconômicos
18.
Mol Cell Endocrinol ; 86(1-2): 103-10, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1324854

RESUMO

Interferon regulatory factor-1 (IRF-1) gene expression is rapidly upregulated in the prolactin (PRL)-activated Nb2 rat T lymphoma cell line. To further elucidate its role as a T cell activation molecule, IRF-1 gene expression in response to various T cell stimuli was examined. In Nb2 T cells, PRL induced two peaks of IRF-1 gene expression: a rapid, transient peak at 1 h and a sustained peak at 12 h. PRL subsequently induced interferon-gamma (IFN-gamma) gene expression at 3-6 h. However, the early induction of IRF-1 and IFN-gamma does not appear to be interdependent. Interleukin-2 (IL-2) also induced IRF-1 gene expression in Nb2 T cells but only one broad peak at 10 h was observed. In primary mouse splenocytes, concanavalin A induced rapid and transient expression of the IRF-1 gene; maximal expression occurred by 6 h, and then returned to basal levels by 12-15 h. These results provide additional evidence for the importance of IRF-1 in T cell activation.


Assuntos
Concanavalina A/farmacologia , Proteínas de Ligação a DNA/biossíntese , Interleucina-2/farmacologia , Fosfoproteínas/biossíntese , Prolactina/farmacologia , RNA Mensageiro/biossíntese , Linfócitos T/metabolismo , Animais , Células Cultivadas , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Fator Regulador 1 de Interferon , Linfoma de Células T/patologia , Camundongos , Camundongos Endogâmicos BALB C , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Ratos , Receptores de Superfície Celular/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Estimulação Química , Linfócitos T/efeitos dos fármacos , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo
19.
Ann N Y Acad Sci ; 945: 164-71, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11708474

RESUMO

Long-term persistence of fetal cells in parous women (fetal microchimerism, FM) as well as maternal cells in their offspring (maternal microchimerism, MM) have been reported. Systemic sclerosis (SSc), primary biliary cirrhosis (PBC), and Sjögren's syndrome (SS) share similar epidemiology with a predilection for females following childbearing years, with clinical similarities to chronic graft-versus-host disease, a known condition of chimerism. This led to the hypothesis that FM could be involved in the pathogenesis of autoimmune diseases. Initial investigations were conducted in SSc, where the hypothesis was supported by the more frequent occurrence and, quantitatively, a greater degree of FM in women with SSc compared to matched healthy women. Long-term persistence, however, of fetal cells in healthy women indicates that FM per se is not sufficient for causing SSc, but may be important in the context of other risk factors, such as genetic susceptibility and HLA relationship among host and nonhost cells. Contradictory results have recently been published for both PBC and SS and cause difficulty in drawing any conclusions about the role of FM in their pathogenesis. On the other hand, MM has been investigated as a risk factor in patients with systemic lupus (SLE) and juvenile dermatomyositis (JDM). A potential role of MM has been suggested in the pathogenesis of SLE. Recent publications also support the hypothesis that MM might lead to increased risks for JDM. In conclusion, contradictory results have been observed. This reflects a need for standardization of protocols and the selection of control populations. Detection of microchimerism has to be quantitatively studied in the context of genetic factors in order to study its relationship to the pathogenesis of autoimmune diseases.


Assuntos
Doenças Autoimunes/genética , Quimera , Feminino , Humanos
20.
Am J Ophthalmol ; 108(5): 516-23, 1989 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-2510519

RESUMO

We evaluated the efficacy of oral norfloxacin in 15 patients with culture-proven gonococcal eye disease caused by Neisseria gonorrhoeae. The first seven patients received 1,200 mg of oral norfloxacin for three consecutive days. The other eight patients were each treated with a single oral dose of 1,200 mg of norfloxacin. All control cultures were negative, and there was no progression of the corneal lesions after treatment was initiated. No adverse effects were observed. The results of this study suggested that a single dose of oral norfloxacin may be a valuable alternative to the currently recommended treatment regimens for gonococcal eye disease because it combines high efficacy and low toxicity with low cost and excellent patient compliance.


Assuntos
Infecções Oculares Bacterianas/tratamento farmacológico , Ceratoconjuntivite/tratamento farmacológico , Neisseria gonorrhoeae/isolamento & purificação , Norfloxacino/uso terapêutico , Administração Oral , Adolescente , Adulto , Ensaios Clínicos como Assunto , Túnica Conjuntiva/microbiologia , Infecções Oculares Bacterianas/etiologia , Infecções Oculares Bacterianas/patologia , Seguimentos , Humanos , Ceratoconjuntivite/etiologia , Ceratoconjuntivite/patologia , Masculino , Norfloxacino/administração & dosagem , Fotografação , Uretra/microbiologia
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