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1.
mBio ; 14(4): e0108323, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37382440

RESUMO

Infection by retroviruses as HIV-1 requires the stable integration of their genome into the host cells. This process needs the formation of integrase (IN)-viral DNA complexes, called intasomes, and their interaction with the target DNA wrapped around nucleosomes within cell chromatin. To provide new tools to analyze this association and select drugs, we applied the AlphaLISA technology to the complex formed between the prototype foamy virus (PFV) intasome and nucleosome reconstituted on 601 Widom sequence. This system allowed us to monitor the association between both partners and select small molecules that could modulate the intasome/nucleosome association. Using this approach, drugs acting either on the DNA topology within the nucleosome or on the IN/histone tail interactions have been selected. Within these compounds, doxorubicin and histone binders calixarenes were characterized using biochemical, in silico molecular simulations and cellular approaches. These drugs were shown to inhibit both PFV and HIV-1 integration in vitro. Treatment of HIV-1-infected PBMCs with the selected molecules induces a decrease in viral infectivity and blocks the integration process. Thus, in addition to providing new information about intasome-nucleosome interaction determinants, our work also paves the way for further unedited antiviral strategies that target the final step of intasome/chromatin anchoring. IMPORTANCE In this work, we report the first monitoring of retroviral intasome/nucleosome interaction by AlphaLISA. This is the first description of the AlphaLISA application for large nucleoprotein complexes (>200 kDa) proving that this technology is suitable for molecular characterization and bimolecular inhibitor screening assays using such large complexes. Using this system, we have identified new drugs disrupting or preventing the intasome/nucleosome complex and inhibiting HIV-1 integration both in vitro and in infected cells. This first monitoring of the retroviral/intasome complex should allow the development of multiple applications including the analyses of the influence of cellular partners, the study of additional retroviral intasomes, and the determination of specific interfaces. Our work also provides the technical bases for the screening of larger libraries of drugs targeting specifically these functional nucleoprotein complexes, or additional nucleosome-partner complexes, as well as for their characterization.


Assuntos
Nucleossomos , Spumavirus , Humanos , Histonas/genética , Integração Viral , Cromatina , Retroviridae/genética , Integrases/genética , DNA Viral/química , Spumavirus/genética
2.
Eur J Neurol ; 27(3): 579-585, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31721389

RESUMO

BACKGROUND AND PURPOSE: The long-term outcomes and stroke recurrence after basilar artery occlusion (BAO) are largely unknown. We aimed to assess these variables in a comparatively large series of consecutive patients. METHODS: Adults with acute BAO were retrospectively identified from 1976 to 2011. Post-discharge records were reviewed to assess for stroke recurrences, mortality and disability. Exploratory analysis of survival was carried out using Kaplan-Meier and log-rank tests. Factors associated with survival time were determined using Cox models. RESULTS: A total of 86 patients (34% female, median age 72 [interquartile range (IQR), 60-79] years) with a median National Institutes of Health Stroke Scale score of 11 (IQR, 6-27) were included. Twenty-nine patients (34%) died during the initial hospitalization. Median modified Rankin Scale (mRS) score at discharge among survivors was 4 (IQR, 2.5-5.5). At 1 and 5 years, 70% of survivors ad a mRS ≤3. Seventeen patients had recurrent strokes during the hospitalization and 12 patients had 19 recurrent strokes after discharge. The median survival time was 52 days (IQR, 6-1846). Older age per decade on admission [adjusted hazard ratios (aHR), 1.32; 95% confidence interval (CI), 1.05-1.66, P = 0.02] and a higher mRS at discharge (aHR, 4.48; 95% CI, 2.72-7.39, P < 0.0001) were associated with mortality. Patients who were not treated with any reperfusion therapy had a trend towards reduced mortality (aHR, 0.39; 95% CI, 0.14-1.08, P = 0.07). CONCLUSIONS: Survivors from BAO had severe short-term functional disability. Most deaths and stroke recurrences occurred within the first year following the initial event. The risk of death was higher in older and more disabled survivors. However, favorable long-term recovery was possible.


Assuntos
Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Insuficiência Vertebrobasilar/complicações , Insuficiência Vertebrobasilar/mortalidade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Avaliação da Deficiência , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
3.
Eur J Clin Microbiol Infect Dis ; 37(7): 1345-1352, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29728782

RESUMO

Respiratory syncytial virus (RSV) may cause severe illness in cystic fibrosis (CF) children, but recommendations vary on prophylaxis. CARESS is a prospective registry of children who received palivizumab in 32 Canadian sites from 2005 to 2016. Demographic data were collected at enrollment and respiratory illness-related events recorded monthly. We reviewed respiratory illness hospitalization (RIH) and RSV hospitalization (RSVH) in CF children aged < 24 months versus those prophylaxed for standard indications (SI; prematurity, chronic lung disease [CLD] and congenital heart disease [CHD]), and complex medical disorders (CM). Of 23,228 children analyzed, 19,452 (83.8%) were SI, 3349 (14.4%) were CM, and 427 (1.8%) were CF. CF children were more likely to be Caucasian, heavier at birth and enrollment, and less likely to have a sibling or live in crowded conditions. CF children were similar to the other groups in daycare attendance, history of atopy, and exposure to smoking. RIH incidences were 4.3% (premature), 13.8% CLD, 11.5% CHD, 11.7% CM, and 6.8% CF. RSVH incidence in CF children was similar to that in the SI and CM groups: 1.1, 1.5, and 2.0% groups respectively. Cox regression analyses showed that compared to CF children, the HRs for RSVH in SI (HR 2.0 95% CI 0.5-8.3, p = 0.3) and CM (HR 2.4, 95% CI 0.6-9.8, p = 0.2) did not differ. CF children are equally at risk for RSVH relative to those prophylaxed for other indications. Pending robust evidence from prospective trials, palivizumab could perhaps be considered in the interim, for young CF patients born early during the RSV season with evidence of serious lung disease.


Assuntos
Antivirais/uso terapêutico , Fibrose Cística/patologia , Palivizumab/uso terapêutico , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Canadá/epidemiologia , Pré-Escolar , Feminino , Cardiopatias Congênitas , Humanos , Lactente , Masculino , Estudos Prospectivos , Sistema de Registros , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico
4.
J Clin Neurosci ; 53: 239-240, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29685413

RESUMO

Tolosa Hunt syndrome (THS) is characterized by painful ophthalmoplegia secondary to idiopathic granulomatous inflammation of the cavernous sinus. The characteristic finding on MRI is an enhancing T1 isointense and T2 hypo- or hyperintense cavernous sinus mass lesion, which may result in focal narrowing of the ipsilateral internal carotid artery. Although the incidence is quite rare, it is a common diagnostic consideration in cases that present with multiple cranial neuropathies. However, the differential diagnosis for a unilateral cavernous sinus lesion in adults is broad and includes neoplastic, inflammatory (such as sarcoidosis and immunoglobulin G4-related disease [IgG4-RD]), infectious etiologies (such as syphilis and leprosy), as well as vascular lesions. We describe a patient presenting with neurologic symptoms referable to a persistent unilateral cavernous sinus MRI abnormality, initially thought to be consistent with Tolosa-Hunt syndrome, that was clinically but not radiographically responsive to steroids. Following reevaluation due to the presence of new symptoms, pathology revealed that the abnormality was most consistent with chordoma, a rare skull based tumor. In patients with a presumed diagnosis of Tolosa-Hunt syndrome, close clinical and radiographic follow-up is imperative, with early consideration for biopsy in patients that fail to respond to treatment both clinically and radiographically.


Assuntos
Seio Cavernoso/patologia , Cordoma/diagnóstico , Cordoma/patologia , Neoplasias da Base do Crânio/diagnóstico , Neoplasias da Base do Crânio/patologia , Diagnóstico Diferencial , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Esteroides/uso terapêutico , Síndrome de Tolosa-Hunt/diagnóstico
5.
Acta Crystallogr D Biol Crystallogr ; 62(Pt 10): 1125-36, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17001090

RESUMO

Protein characterization plays a role in two key aspects of structural proteomics. The first is the quality assessment of the produced protein preparations. Obtaining well diffracting crystals is one of the major bottlenecks in the structure-determination pipeline. Often, this is caused by the poor quality of the protein preparation used for crystallization trials. Hence, it is essential to perform an extensive quality assessment of the protein preparations prior to crystallization and to use the results in the evaluation of the process. Here, a protein-production and crystallization strategy is proposed with threshold values for protein purity (95%) and monodispersity (85%) below which a further optimization of the protein-production process is strongly recommended. The second aspect is the determination of protein characteristics such as domains, oligomeric state, post-translational modifications and protein-protein and protein-ligand interactions. In this paper, applications and new developments of protein-characterization methods using MS, fluorescence spectroscopy, static light scattering, analytical ultracentrifugation and small-angle X-ray scattering within the EC Structural Proteomics in Europe contract are described. Examples of the application of the various methods are given.


Assuntos
Proteínas/metabolismo , Proteômica/métodos , Cristalização , Hidrólise , Luz , Espectrometria de Massas , Microscopia de Fluorescência , Modelos Moleculares , Conformação Proteica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espalhamento de Radiação , Tripsina , Ultracentrifugação , Raios X
6.
Neuroscience ; 134(2): 671-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15979806

RESUMO

Chronic neuroinflammation plays a prominent role in the progression of Alzheimer's disease. Reactive microglia and astrocytes are observed within the hippocampus during the early stages of the disease. Epidemiological findings suggest that anti-inflammatory therapies may slow the onset of Alzheimer's disease. Chemokine receptor 5 (CCR5) up-regulation may influence the recruitment and accumulation of glia near senile plaques; activated microglia express CCR5 and reactive astrocytes express chemokines. We have previously shown that neuroinflammation induced by chronic infusion of lipopolysaccharide into the 4th ventricle reproduces many of the behavioral, neurochemical, electrophysiological and neuropathological changes associated with Alzheimer's disease. The current study investigated the ability of D-Ala-peptide T-amide (DAPTA), a chemokine receptor 5 chemokine receptor antagonist of monocyte chemotaxis, to influence the consequences of chronic infusion of lipopolysaccharide. DAPTA (0.01 mg/kg, s.c., for 14 days) dramatically reduced the number of activated microglia and astrocytes, as compared with lipopolysaccharide-infused rats treated with vehicle. DAPTA treatment also reduced the number of immunoreactive cells expressing nuclear factor kappa binding protein, a prominent component of the proinflammatory cytokine signaling pathway. The present study suggests that DAPTA and other CCR5 antagonists may attenuate critical aspects of the neuroinflammation associated with Alzheimer's disease.


Assuntos
Astrócitos/fisiologia , Antagonistas dos Receptores CCR5 , Dipeptídeos/farmacologia , Hipocampo/fisiopatologia , Microglia/fisiologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Inflamação , Lipopolissacarídeos/toxicidade , Microglia/efeitos dos fármacos , Microscopia Confocal , Ratos
7.
Med Res Rev ; 21(6): 523-39, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11607933

RESUMO

The aim of this study is to compare crystal structures of nuclear receptor ligand binding domains in complex with different agonists and partial agonists to achieve a better understanding of the three-dimensional structures and their ligand-induced conformational changes. This led to the identification of structurally conserved "rigid" regions and more flexible parts of the proteins. The analysis was found to be of great value in fitting selected non-steroidal compounds into the human estrogen receptor alpha (hER alpha) ligand binding pocket. The experimentally determined binding affinities for a number of 2-aryl indoles and 2-aryl indenones are in good agreement with the subsequently modeled binding interactions. To date, no crystal structure is published for a complex with a pure antagonist. We therefore used the available structural information on complexes with partial agonists and the crystal structure of a mutant protein in complex with estradiol displaying a similar conformation to predict binding interactions for antagonists. The results are discussed in detail.


Assuntos
Receptores de Estrogênio/química , Humanos , Ligantes , Modelos Moleculares , Conformação Molecular , Receptores de Estrogênio/metabolismo
8.
Antiviral Res ; 52(1): 63-75, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11530189

RESUMO

Peptide T, which is derived from the V2 region of HIV-1, inhibits replication of R5 and dual-tropic (R5/X4) HIV-1 strains in monocyte-derived macrophages (MDMs), microglia, and primary CD4(+)T cells. Little to no inhibition by peptide T was observed with lab adapted X4 viruses such as IIIB, MN, or NL4-3 propagated in CD4(+) T cells or in the MAGI entry assay. The more clinically relevant R5/X4 early passage patient isolates were inhibited via either the X4 or R5 chemokine receptors, although inhibition was greater with R5 compared to X4 receptors. Virus inhibition ranged from 60 to 99%, depending on the assay, receptor target, viral isolate and amount of added virus. Peak inhibitory effects were detected at concentrations from 10(-12) to 10(-9) M. Peptide T acted to block viral entry as it inhibited in the MAGI cell assay and blocked infection in the luciferase reporter assay using HIV virions pseudotyped with ADA envelope. These results using early passage virus grown in primary cells, together with two different entry reporter assays, show that peptide T selectively inhibits HIV replication using chemokine receptor CCR5 compared to CXC4, explaining past inconsistencies of in vitro antiviral effects.


Assuntos
HIV-1/fisiologia , Peptídeo T/fisiologia , Receptores CCR5/fisiologia , Replicação Viral/efeitos dos fármacos , Anticorpos Monoclonais/imunologia , Antivirais/metabolismo , Bioensaio , Células Cultivadas , Quimiocinas/antagonistas & inibidores , Quimiocinas/metabolismo , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Feto , Citometria de Fluxo , Genes Reporter , Proteína do Núcleo p24 do HIV/imunologia , HIV-1/metabolismo , Células HeLa , Humanos , Luciferases/análise , Luciferases/genética , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/virologia , Microglia/citologia , Microglia/metabolismo , Microglia/virologia , Peptídeo T/imunologia , Fatores de Tempo
9.
Protein Expr Purif ; 22(2): 165-73, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11437591

RESUMO

Several crystal structures of human estrogen receptor alpha ligand-binding domain (hERalpha LBD) complexed with agonist or antagonist molecules have previously been solved. The proteins had been modified in cysteine residues (carboxymethylation) or renatured in urea to circumvent aggregation and denaturation problems. In this work, high-level protein expression and purification together with crystallization screening procedure yielded high amounts of soluble protein without renaturation or modifications steps. The native protein crystallizes in the space group P3(2) 21 with three molecules in the asymmetric unit. The overall structure is very similar to that previously reported for the hERalpha LBD with cysteine carboxymethylated residues thus validating the modification approach. The present strategy can be adapted to other cases where the solubility and the proper folding is a difficulty.


Assuntos
Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Receptores de Estrogênio/química , Receptores de Estrogênio/isolamento & purificação , Clonagem Molecular , Simulação por Computador , Cristalização , Cristalografia por Raios X , Dimerização , Receptor alfa de Estrogênio , Humanos , Ligantes , Modelos Moleculares , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Dobramento de Proteína , Estrutura Secundária de Proteína/genética , Estrutura Terciária de Proteína/genética , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo
10.
J Mol Biol ; 307(2): 577-86, 2001 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-11254383

RESUMO

Stromelysin-3 (ST3) is a matrix metalloproteinase (MMP-11) whose proteolytic activity plays an important role in tumorigenicity enhancement. In breast cancer, ST3 is a bad prognosis marker: its expression is associated with a poor clinical outcome. This enzyme therefore represents an attractive therapeutic target. The topology of matrix metalloproteinases (MMPs) is remarkably well conserved, making the design of highly specific inhibitors difficult. The major difference between MMPs lies in the S(1)' subsite, a well-defined hydrophobic pocket of variable depth. The present crystal structure, the first 3D-structure of the ST3 catalytic domain in interaction with a phosphinic inhibitor mimicking a (d, l) peptide, clearly demonstrates that its S(1)' pocket corresponds to a tunnel running through the enzyme. This open channel is filled by the inhibitor P(1)' group which adopts a constrained conformation to fit this pocket, together with two water molecules interacting with the ST3-specific residue Gln215. These observations provide clues for the design of more specific inhibitors and show how ST3 can accommodate a phosphinic inhibitor mimicking a (d, l) peptide. The presence of a water molecule interacting with one oxygen atom of the inhibitor phosphinyl group and the proline residue of the Met-turn suggests how the intermediate formed during proteolysis may be stabilized. Furthermore, the hydrogen bond distance observed between the methyl of the phosphinic group and the carbonyl group of Ala182 mimics the interaction between this carbonyl group and the amide group of the cleaved peptidic bond. Our crystal structure provides a good model to study the MMPs mechanism of proteolysis.


Assuntos
Metaloendopeptidases/química , Oligopeptídeos/química , Sequência de Aminoácidos , Sítios de Ligação , Cálcio/química , Cátions Bivalentes/química , Cátions Bivalentes/metabolismo , Simulação por Computador , Cristalografia por Raios X , Desenho de Fármacos , Ligação de Hidrogênio , Ligantes , Metaloproteinase 11 da Matriz , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Oligopeptídeos/farmacologia , Inibidores de Proteases/farmacologia , Alinhamento de Sequência , Zinco/química
11.
J Biol Chem ; 276(18): 15059-65, 2001 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-11278577

RESUMO

The crystal structure of a triple cysteine to serine mutant ERalpha ligand-binding domain (LBD), complexed with estradiol, shows that despite the presence of a tightly bound agonist ligand, the protein exhibits an antagonist-like conformation, similar to that observed in raloxifen and 4-hydroxytamoxifen-bound structures. This mutated receptor binds estradiol with wild type affinity and displays transcriptional activity upon estradiol stimulation, but with limited potency (about 50%). This partial activity is efficiently repressed in antagonist competition assays. The comparison with available LBD structures reveals key features governing the positioning of helix H12 and highlights the importance of cysteine residues in promoting an active conformation. Furthermore the present study reveals a hydrogen bond network connecting ligand binding to protein trans conformation. These observations support a dynamic view of H12 positioning, where the control of the equilibrium between two stable locations determines the partial agonist character of a given ligand.


Assuntos
Receptores de Estrogênio/química , Receptores de Estrogênio/metabolismo , Clonagem Molecular , Cristalografia por Raios X , Antagonistas de Estrogênios/farmacologia , Receptor alfa de Estrogênio , Humanos , Ligação de Hidrogênio , Ligantes , Modelos Moleculares , Mutagênese Sítio-Dirigida , Conformação Proteica , Receptores de Estrogênio/agonistas , Receptores de Estrogênio/genética
12.
Ann Allergy Asthma Immunol ; 85(5): 407-15, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11101186

RESUMO

BACKGROUND: Flovent Diskus is a powder formulation of the inhaled corticosteroid fluticasone propionate (FP) delivered via a breath-actuated, multidose inhaler. OBJECTIVE: To determine the efficacy and safety of dry powder FP administered once or twice daily (200 microg per day) to children with persistent asthma. METHODS: Twelve-week, randomized, double-blind, placebo-controlled, multicenter trial with a 52-week, open-label extension. Children aged 4 to 11 were required to have pulmonary function 50% to 85% of predicted values. The population was stratified for baseline therapy (inhaled corticosteroid/cromolyn or bronchodilators only). After a 2-week placebo run-in, 242 patients received dry powder FP 200 microg each morning, dry powder FP 100 microg BID, or placebo for 12 weeks; 192 were rerandomized to the QD or BID regimen for an additional 52 weeks of open-label treatment. Primary endpoints were mean changes in FEV1 and morning PEF recorded at clinic visits. RESULTS: Both dry powder FP regimens significantly improved FEV1, evening PEF, and asthma symptoms at the double-blind phase endpoint (P < or = .017 compared with placebo). The BID regimen also significantly improved morning PEF and nighttime awakenings due to asthma (P < or = .005). Among patients previously treated with inhaled corticosteroids/cromolyn, improvements observed with the QD and BID regimens were similar. Patients switched from BID to open-label QD treatment showed additional improvements at week 52 generally comparable to patients who received the BID regimen during both phases. Fluticasone propionate was well tolerated for up to 64 weeks with few reports of drug-related adverse events or morning plasma cortisol abnormalities. CONCLUSIONS: Once daily dosing of dry powder FP 200 microg is an effective and convenient alternative for children whose asthma is controlled with a more frequent dosing regimen of inhaled corticosteroids.


Assuntos
Androstadienos/farmacocinética , Androstadienos/uso terapêutico , Antiasmáticos/farmacocinética , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Fluticasona , Volume Expiratório Forçado/efeitos dos fármacos , Humanos , Masculino , Pós , Equivalência Terapêutica
13.
EMBO J ; 19(11): 2592-601, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10835357

RESUMO

The pleiotropic effects of active retinoids are transduced by their cognate nuclear receptors, retinoid X receptors (RXRs) and retinoic acid receptors (RARs), which act as transcriptional regulators activated by two stereoisomers of retinoic acid (RA): 9-cis RA (9-cRA) and all-trans RA (a-tRA). Among nuclear receptors, RXR occupies a central position and plays a crucial role in many intracellular signalling pathways as a ubiquitous heterodimerization partner with numerous other members of this superfamily. Whereas RARs bind both isomers, RXRs exclusively bind 9-cRA. The crystal structure of the ligand-binding domain (LBD) of human RXRalpha bound to 9-cRA reveals the molecular basis of this ligand selectivity and allows a comparison of both apo and holo forms of the same nuclear receptor. In the crystal, the receptor is monomeric and exhibits a canonical agonist conformation without direct contacts between the ligand and the transactivation helix H12. Comparison with the unliganded RXRalpha LBD structure reveals the molecular mechanisms of ligand-induced conformational changes and allows us to describe at the atomic level how these changes generate the proper protein interface involved in nuclear receptor-coactivator interaction.


Assuntos
Receptores do Ácido Retinoico/química , Fatores de Transcrição/química , Tretinoína/metabolismo , Alitretinoína , Apoproteínas/química , Apoproteínas/metabolismo , Sítios de Ligação , Cristalização , Cristalografia por Raios X , Humanos , Ligantes , Substâncias Macromoleculares , Modelos Moleculares , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Conformação Proteica , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Receptores X de Retinoides , Estereoisomerismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional
14.
Pediatrics ; 105(2): E22, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10654982

RESUMO

OBJECTIVE: Intranasal corticosteroids are used widely for the treatment of allergic rhinitis because they are effective and well tolerated. However, their potential to suppress growth of pediatric subjects with allergic rhinitis continues to be a concern, particularly in light of reports of growth suppression after treatment with intranasal beclomethasone dipropionate or intranasal budesonide (see the article by Skoner et al in this month's issue). A 1-year study of prepubertal patients between 3 and 9 years of age with perennial allergic rhinitis was conducted to assess the effects on growth of mometasone furoate aqueous nasal spray (MFNS), a new once-daily (QD) intranasal corticosteroid with negligible bioavailability. METHODS: This was a randomized, placebo-controlled, double-blind, multicenter study. Ninety-eight subjects were randomized to treatment with either MFNS 100 microg QD or placebo for 1 year. Each subject's height was required to be between the 5th and 95th percentile at baseline, and skeletal age at screening was required to be within 2 years of chronological age, as determined by left wrist x-rays. Washout periods for medications that affect either childhood growth or allergic rhinitis symptoms were established based on estimated period of effect, and these medications were prohibited during the study. However, short courses of either oral prednisone lasting no longer than 7 days or low-potency topical dermatologic corticosteroids lasting no longer than 10 days were permitted if necessary. Height was measured with a calibrated stadiometer at baseline and at 4, 8, 12, 26, 39, and 52 weeks, and the primary safety variable was the change in standing height. The rate of growth was also calculated for each subject as the slope (linear regression) of the change in height from baseline using data from all visits of subjects who had at least 2 visits. Hypothalamic-pituitary-adrenocortical- (HPA)-axis function was assessed via cosyntropin stimulation testing at baseline and at 26 and 52 weeks. All analyses were based on all randomized subjects (intent-to-treat principle). The change from baseline in standing height was analyzed by a 2-way analysis of variance that extracted sources of variation attributable to treatment, center, and treatment-by-center interaction. RESULTS: Demographic characteristics were similar at baseline. Eighty-two subjects completed the study (42 in the MFNS group and 40 in the placebo group), and 93% of subjects achieved at least 80% compliance with therapy. After 1 year of treatment, no suppression of growth was seen in subjects treated with MFNS, and mean standing heights were similar for both treatment groups at all time points. For the primary safety variable (change in height from baseline), both treatment groups were similar at all time points except for weeks 8 and 52. Subjects treated with MFNS had a slightly greater mean increase in height than subjects treated with placebo at these time points: the change in height was 6.95 cm versus 6.35 cm at the 1-year time point. However, the rate of growth (.018 cm/day) averaged for all time points over the course of the study was similar for both treatment groups. Additional analyses found that MFNS did not retard growth in any sex or age subgroup of subjects. The use of exogenous corticosteroids other than the study drug was also similar among the 2 treatment groups. Results from cosyntropin stimulation testing confirmed the absence of systemic effects of MFNS. The change from baseline in the difference between prestimulation and poststimulation levels was similar for both treatment groups after 1 year of treatment, with no evidence of HPA-axis suppression in MFNS-treated subjects at any time point. Incidences of treatment-related adverse events were similar for both treatment groups, with 16% of MFNS-treated subjects reporting adverse events, compared with 22% of placebo-treated subjects. CONCLUSIONS: (ABSTRACT TRUNCATED)


Assuntos
Anti-Inflamatórios/uso terapêutico , Crescimento/efeitos dos fármacos , Pregnadienodiois/uso terapêutico , Rinite Alérgica Perene/tratamento farmacológico , Administração Intranasal , Anti-Inflamatórios/efeitos adversos , Criança , Método Duplo-Cego , Feminino , Glucocorticoides , Transtornos do Crescimento/induzido quimicamente , Humanos , Masculino , Furoato de Mometasona , Pregnadienodiois/efeitos adversos
15.
Breast Cancer Res ; 2(5): 353-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11250728

RESUMO

Estrogen receptors are members of the nuclear receptor steroid family that exhibit specific structural features, ligand-binding domain sequence identity and dimeric interactions, that single them out. The crystal structures of their DNA-binding domains give some insight into how nuclear receptors discriminate between DNA response elements. The various ligand-binding domain crystal structures of the two known estrogen receptor isotypes (alpha and beta) allow one to interpret ligand specificity and reveal the interactions responsible for stabilizing the activation helix H12 in the agonist and antagonist positions.


Assuntos
DNA/metabolismo , Ligantes , Receptores de Estrogênio/metabolismo , Transcrição Gênica , Ativação Transcricional , Sequência de Aminoácidos , Animais , DNA/química , Humanos , Dados de Sequência Molecular , Receptores de Estrogênio/química , Receptores de Estrogênio/genética , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade
16.
Clin Immunol ; 93(2): 124-31, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10527688

RESUMO

We previously reported that certain short gp120 V2 region peptides homologous to vasaoactive intestinal peptide (VIP), such as "peptide T," were potent inhibitors of gp120 binding, infectivity, and neurotoxicity. The present study shows that synthetic V2-region-derived peptides have potent intrinsic chemotaxis agonist activity for human monocytes and also act as antagonists of high-affinity (0.1 pM) gp120-mediated monocyte chemotaxis. Selectivity is shown in that peptide T is more potent at suppressing M-tropic than T-tropic gp120 chemotaxis. Peptide T was also able to suppress monocyte chemotaxis to MIP-1beta, a chemokine with selectivity for CCR5 chemokine receptors, while chemotaxis of the more promiscuous ligand RANTES was not inhibited, nor was chemotaxis mediated by SDF-1alpha. In order to determine if peptide T mediated its gp120 antagonistic effects via modulation of CCR5 receptors, RANTES chemotaxis was studied using a CCR5 receptor-transfected HOS cell line. In this case, RANTES chemotaxis was potently inhibited by V2-region-derived short peptides. Peptide T also partially suppressed (125)I-MIP1-beta binding to human monocytes, suggesting action at a subset of MIP1-beta receptors. The V2 region of gp120 thus contains a potent receptor binding domain and synthetic peptides derived from this region modulate CCR5 chemokine receptor chemotactic signaling caused by either gp120 or chemokine ligands. The results have therapeutic implications and may explain recent clinical improvements, in that HIV/gp120 actions at CCR5 receptors, such as occur in the brain or early infection, would be susceptible to peptide T inhibition.


Assuntos
Antagonistas dos Receptores CCR5 , Fatores Quimiotáticos/antagonistas & inibidores , Fatores Quimiotáticos/fisiologia , Quimiotaxia/imunologia , Proteína gp120 do Envelope de HIV/fisiologia , Peptídeo T/metabolismo , Células Cultivadas , Quimiocina CCL5/antagonistas & inibidores , Quimiocina CCL5/imunologia , Quimiocinas/antagonistas & inibidores , Quimiocinas/metabolismo , Humanos , Monócitos/imunologia , Monócitos/metabolismo , Peptídeo T/imunologia , Peptídeos , Isoformas de Proteínas/metabolismo
18.
Vet Parasitol ; 84(3-4): 337-47, 1999 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-10456422

RESUMO

Poultry now accounts for 30% of all meat consumed. Parasites are a problem where ever poultry are raised, whether in large commercial operations or in small back-yard flocks, and economic losses can be significant. This paper will briefly review the major protozoan, helminth, and arthropod species in poultry including pathogenesis. Other topics will include the importance of the interaction of other diseases and parasites, and control of the infection by chemotherapy, management, and immunity.


Assuntos
Infecções por Cestoides/veterinária , Coccidiose/veterinária , Ectoparasitoses/veterinária , Infecções por Nematoides/veterinária , Doenças das Aves Domésticas/parasitologia , Criação de Animais Domésticos , Animais , Anti-Helmínticos/uso terapêutico , Artrópodes/patogenicidade , Cestoides/patogenicidade , Infecções por Cestoides/tratamento farmacológico , Infecções por Cestoides/prevenção & controle , Coccidiose/tratamento farmacológico , Coccidiose/prevenção & controle , Coccidiostáticos/uso terapêutico , Ectoparasitoses/tratamento farmacológico , Ectoparasitoses/prevenção & controle , Eimeria/patogenicidade , Inseticidas/uso terapêutico , Nematoides/patogenicidade , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/prevenção & controle , Aves Domésticas , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/prevenção & controle
19.
Brain Res ; 838(1-2): 27-36, 1999 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-10446313

RESUMO

Vasoactive intestinal peptide (VIP) and DAPTA (D-ala(1)-peptide T-amide, a gp120-derived octapeptide homologous to VIP) prevent neuronal cell death produced by five variants of HIV-1 (human immunodeficiency virus) envelope protein (gp120). VIP or DAPTA treatment of astrocyte cultures resulted in the release of macrophage inflammatory protein-1alpha (MIP-1alpha) and RANTES, beta chemokines known to block gp120 interactions with microglial chemokine receptors. In rat cerebral cortical cultures, gp120-induced neuronal killing was partially or completely prevented by chemokines that stimulate the CXCR4, CCR3 or CCR5 chemokine receptors. Chemokines exhibited marked differences in potency and efficacy in preventing toxicity associated with five gp120 variants (LAV/BRU, CM243, RF, SF2, and MN). RANTES had the broadest and most potent inhibition (IC(50)<3 pM for RF isolate). An octapeptide derived from RANTES also exhibited neuroprotection from gp120 (RF isolate) toxicity (IC(50)=0.3 microM). Treatment with chemokines alone had no detectable effect on neuronal cell number. However, antiserum to MIP-1alpha produced neuronal cell death that was prevented by co-treatment with MIP-1alpha, suggesting that this endogenous chemokine exerts a tonic regulation important to neuronal survival. The neuroprotective action of VIP on gp120 was attenuated by co-treatment with anti-MIP-1alpha. These studies suggest that the neuroprotective action of VIP is linked in part to its release of MIP-1alpha. Furthermore, neuroprotection produced by chemokines is dependent on both the type of chemokine and the variant structure of gp120 and may be relevant to drug strategies for the treatment of AIDS dementia.


Assuntos
Quimiocinas/metabolismo , Proteína gp120 do Envelope de HIV/genética , HIV , Neurônios/efeitos dos fármacos , Peptídeo T/farmacologia , Peptídeo Intestinal Vasoativo/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL5/análise , Variação Genética , Neurônios/patologia , Neurotoxinas/genética , Ratos
20.
J Allergy Clin Immunol ; 104(1): 107-14, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10400847

RESUMO

BACKGROUND: The efficacy and safety of mometasone furoate aqueous nasal spray (MFNS; Nasonex) 200 microg once daily for the treatment and prophylaxis of seasonal allergic rhinitis (SAR) and treatment of perennial rhinitis have been demonstrated in adults. However, the dose response of MFNS in pediatric patients has not yet been characterized. OBJECTIVE: This study was conducted to determine the dose-response relationship of 3 different doses of MFNS in a pediatric population. METHODS: This was a multicenter, double-blind, active- and placebo-controlled study of 679 children 6 to 11 years of age with histories of SAR and documented positive skin test responses. Patients were randomized to one of the following treatment groups for 4 weeks: MFNS 25 microgram once daily, MFNS 100 microgram once daily, MFNS 200 microgram once daily, beclomethasone dipropionate 84 microgram twice daily (168 microgram/day), or placebo. Physician evaluations were performed at days 4, 8, 15, and 29, and patient evaluations were analyzed for days 1 to 15 and 16 to 29. RESULTS: The mean reduction from baseline in physician-evaluated total nasal symptom scores at day 8 (the primary efficacy variable) was significantly greater in the MFNS and beclomethasone dipropionate groups than in the placebo group (P

Assuntos
Anti-Inflamatórios/administração & dosagem , Pregnadienodiois/administração & dosagem , Rinite Alérgica Sazonal/tratamento farmacológico , Administração Intranasal , Anti-Inflamatórios/farmacocinética , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Método Duplo-Cego , Tolerância a Medicamentos , Feminino , Glucocorticoides , Humanos , Masculino , Furoato de Mometasona , Placebos , Pregnadienodiois/farmacocinética , Equivalência Terapêutica
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