Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 111
Filtrar
1.
Sci Total Environ ; 616-617: 1101-1123, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29132720

RESUMO

The rapid increase of the world population constantly demands more food production from agricultural soils. This causes conflicts, since at the same time strong interest arises on novel bio-based products from agriculture, and new perspectives for rural landscapes with their valuable ecosystem services. Agriculture is in transition to fulfill these demands. In many countries, conventional farming, influenced by post-war food requirements, has largely been transformed into integrated and sustainable farming. However, since it is estimated that agricultural production systems will have to produce food for a global population that might amount to 9.1 billion by 2050 and over 10 billion by the end of the century, we will require an even smarter use of the available land, including fallow and derelict sites. One of the biggest challenges is to reverse non-sustainable management and land degradation. Innovative technologies and principles have to be applied to characterize marginal lands, explore options for remediation and re-establish productivity. With view to the heterogeneity of agricultural lands, it is more than logical to apply specific crop management and production practices according to soil conditions. Cross-fertilizing with conservation agriculture, such a novel approach will provide (1) increased resource use efficiency by producing more with less (ensuring food security), (2) improved product quality, (3) ameliorated nutritional status in food and feed products, (4) increased sustainability, (5) product traceability and (6) minimized negative environmental impacts notably on biodiversity and ecological functions. A sustainable strategy for future agriculture should concentrate on production of food and fodder, before utilizing bulk fractions for emerging bio-based products and convert residual stage products to compost, biochar and bioenergy. The present position paper discusses recent developments to indicate how to unlock the potentials of marginal land.

2.
Glob Chang Biol ; 21(2): 676-97, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25204435

RESUMO

We present quantitative reconstructions of regional vegetation cover in north-western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1° × 1° spatial scale with the objective of producing vegetation descriptions suitable for climate modelling. The REVEALS model was applied on 636 pollen records from lakes and bogs to reconstruct the past cover of 25 plant taxa grouped into 10 plant-functional types and three land-cover types [evergreen trees, summer-green (deciduous) trees, and open land]. The model corrects for some of the biases in pollen percentages by using pollen productivity estimates and fall speeds of pollen, and by applying simple but robust models of pollen dispersal and deposition. The emerging patterns of tree migration and deforestation between 6k bp and modern time in the REVEALS estimates agree with our general understanding of the vegetation history of Europe based on pollen percentages. However, the degree of anthropogenic deforestation (i.e. cover of cultivated and grazing land) at 3k, 0.5k, and 0.2k bp is significantly higher than deduced from pollen percentages. This is also the case at 6k in some parts of Europe, in particular Britain and Ireland. Furthermore, the relationship between summer-green and evergreen trees, and between individual tree taxa, differs significantly when expressed as pollen percentages or as REVEALS estimates of tree cover. For instance, when Pinus is dominant over Picea as pollen percentages, Picea is dominant over Pinus as REVEALS estimates. These differences play a major role in the reconstruction of European landscapes and for the study of land cover-climate interactions, biodiversity and human resources.


Assuntos
Biodiversidade , Mudança Climática , Modelos Teóricos , Dispersão Vegetal , Europa (Continente) , Pólen
4.
Aliment Pharmacol Ther ; 40(6): 648-56, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25039978

RESUMO

BACKGROUND: Little is known regarding patient characteristics that influence the speed of reflux oesophagitis (RO) healing. AIM: To investigate patient characteristics that may influence RO healing rates. METHODS: A post hoc analysis of clinical trial data for potent acid suppression treatment of RO (esomeprazole or AZD0865) was conducted. Group A underwent endoscopy at baseline, week 2 and 4, and group B at baseline, week 4 and 8. Group A patients were sub-grouped as 'rapid' (healed at 2 weeks) or unhealed at 2 weeks. Group B patients were sub-grouped as 'slow' (healed at 8 weeks, not at 4 weeks) or 'refractory' (not healed at 8 weeks). Logistic regression analysis was performed only for comparisons within group A. RESULTS: At 2, 4 and 8 weeks, RO had healed in 68%, 65% and 61% of patients unhealed at previous endoscopy, respectively. Low-grade [vs. high-grade (C or D)] RO was the only independent predictor of rapid healing in group A after logistic regression analysis. Significantly more rapid healers had low grade RO (A or B) at baseline than patients with refractory RO (84% vs. 49%; P < 0.001), and significantly more refractory patients had frequent regurgitation at baseline than slow healers (80% vs. 63%; P = 0.039). CONCLUSIONS: Low- (vs. high-) grade RO determines the most rapid benefit from acid suppression. Roughly two-thirds of patients healed with each time increment of potent acid suppression therapy. This suggests that some unhealed patients may still heal with continued therapy and that truly refractory RO is rare. (ClinicalTrials.gov: NCT00206245).


Assuntos
Esomeprazol/uso terapêutico , Esofagite Péptica/tratamento farmacológico , Imidazóis/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Piridinas/uso terapêutico , Adulto , Método Duplo-Cego , Resistência a Medicamentos , Endoscopia , Esofagite Péptica/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cicatrização
5.
J Integr Neurosci ; 12(4): 513-28, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24372069

RESUMO

The aim of this research proposal was to investigate the effects of tetrahydropalmatine (THP) on gene expression in a post-traumatic stress disorder (PTSD) rodent model. Eighty male Sprague-Dawley rats were randomly assigned to the nonstressed groups or the 3-day restraint shock PTSD rodent model groups. There were four groups within the nonstressed rats (control, THP, midazolam, and midazolam with THP) and four groups within the stressed rats (control, THP, midazolam, and midazolam with THP). After injection the subjects were euthanized and the amygdala and hippocampus were sent for reverse transcriptase-polymerase chain reaction gene expression analysis. Of the genes interrogated, 17 genes in the amygdala and 18 genes in the hippocampus were found to have significant changes in gene expression and regulation. Significant transcriptional fold changes were found in important genes involved in dopamine, serotonin, acetylcholine, and gamma-aminobutyric acid neurotransmitter systems. The results provide quantifiable data demonstrating gene expression changes in PTSD-stressed and nonstressed rats receiving various treatments. These findings contribute important data to the limited molecular details pertaining to the neurobiology of PTSD.


Assuntos
Analgésicos não Narcóticos/farmacologia , Alcaloides de Berberina/farmacologia , Encéfalo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Receptores de Neurotransmissores/metabolismo , Transtornos de Estresse Pós-Traumáticos/patologia , Adjuvantes Anestésicos/farmacologia , Adjuvantes Anestésicos/uso terapêutico , Analgésicos não Narcóticos/uso terapêutico , Análise de Variância , Animais , Alcaloides de Berberina/uso terapêutico , Encéfalo/metabolismo , Modelos Animais de Doenças , Masculino , Midazolam/farmacologia , Midazolam/uso terapêutico , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , RNA Mensageiro , Ratos , Ratos Sprague-Dawley , Receptores de Neurotransmissores/genética , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico
6.
Diabetes Obes Metab ; 15(11): 1056-60, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23701286

RESUMO

This study explored sex differences in 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) activity and gene expression in isolated adipocytes and adipose tissue (AT), obtained via subcutaneous biopsies from non-diabetic subjects [58 M, 64 F; age 48.3 ± 15.3 years, body mass index (BMI) 27.2 ± 3.9 kg/m²]. Relationships with adiposity and insulin resistance (IR) were addressed. Males exhibited higher 11ß-HSD1 activity in adipocytes than females, but there was no such difference for AT. In both men and women, adipocyte 11ß-HSD1 activity correlated positively with BMI, waist circumference, % body fat, adipocyte size and with serum glucose, triglycerides and low-density lipoprotein:high-density lipoprotein (LDL:HDL) ratio. Positive correlations with insulin, HOMA-IR and haemoglobin A1c (HbA1c) and a negative correlation with HDL-cholesterol were significant only in males. Conversely, 11ß-HSD1 activity in AT correlated with several markers of IR and adiposity in females but not in males, but the opposite pattern was found with respect to 11ß-HSD1 mRNA expression. This study suggests that there are sex differences in 11ß-HSD1 regulation and in its associations with markers of obesity and IR.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Adiposidade , Regulação Enzimológica da Expressão Gênica , Resistência à Insulina , Sobrepeso/metabolismo , Gordura Subcutânea/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/genética , Biomarcadores/sangue , Biomarcadores/metabolismo , Biópsia , Índice de Massa Corporal , Tamanho Celular , Células Cultivadas , Feminino , Hemoglobinas Glicadas/análise , Humanos , Hiperlipidemias/etiologia , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Sobrepeso/complicações , Sobrepeso/patologia , Sobrepeso/fisiopatologia , RNA Mensageiro/metabolismo , Caracteres Sexuais , Gordura Subcutânea/enzimologia , Gordura Subcutânea/patologia
7.
Aliment Pharmacol Ther ; 34(7): 714-23, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21848799

RESUMO

BACKGROUND: Patients with dyspepsia often experience troublesome symptoms. AIM: To assess the burden of uninvestigated dyspepsia (symptoms, health-related quality of life [HRQL] and work productivity) before and after 8 weeks' esomeprazole treatment. METHODS: Patients (n=1250) with uninvestigated dyspepsia (no endoscopy within 6 months and ≤ 2 endoscopies within 10 years) underwent a 1-week esomeprazole acid-suppression test before randomisation to 7 weeks' esomeprazole or placebo. The Reflux Disease Questionnaire (RDQ), Quality of Life in Reflux and Dyspepsia (QOLRAD) and Work Productivity and Activity Impairment (WPAI) questionnaires were completed at baseline (1-week off-treatment) and 8 weeks. WPAI results were further analysed among patients who responded to the acid-suppression test. RESULTS: The highest baseline symptom score was for the RDQ dyspepsia domain, and the highest disease burden was for QOLRAD vitality and food/drink problems. After 8 weeks, significant improvements vs. placebo were observed for all RDQ and QOLRAD domains. The sub-population of acid-suppression test responders, but not the total WPAI population, had a significant work productivity improvement vs. placebo. CONCLUSIONS: Uninvestigated dyspepsia is associated with high symptom load and impacts on HRQL and work productivity. Esomeprazole improves HRQL among such patients, and improves work productivity among 1-week acid-suppression trial responders. ClinicalTrials.gov identifier: NCT00251992.


Assuntos
Antiulcerosos/uso terapêutico , Efeitos Psicossociais da Doença , Dispepsia/tratamento farmacológico , Dispepsia/economia , Esomeprazol/uso terapêutico , Adolescente , Adulto , Antiulcerosos/economia , Método Duplo-Cego , Esomeprazol/economia , Humanos , Pessoa de Meia-Idade , Qualidade de Vida , Análise de Regressão , Índice de Gravidade de Doença , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
8.
Horm Metab Res ; 42(11): 798-802, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20514603

RESUMO

The aim of this study was to measure 11ß-HSD-1 activity in subcutaneous adipose tissue by an ex vivo method in three subgroups; lean, obese, and type 2 diabetes subjects, both in the fasting state and after a mixed meal and to determine the variability and reproducibility of this method. Eighteen subjects were investigated; 6 lean, 6 abdominally obese, and 6 type 2 diabetes subjects (BMI 22 ± 1, 30 ± 3 and 31 ± 3 kg/m², respectively). Needle biopsies were taken repeatedly and an index of 11ß-HSD-1 activity was measured as percent conversion of (3)H-cortisone to (3)H-cortisol/100 mg tissue. For two separate biopsies taken in the fasting state on the same day, the within subjects CV was 16% and the between CV was 36% for 11ß-HSD-1 activity for all subjects. For two biopsies taken in the fasting state at two different days, the total within subjects CV was 38% and the between subjects CV was 46%. Lean subjects had lower 11ß-HSD-1 activity (4.8 ± 1.5% conversion of ³H-cortisone to ³H-cortisol/100 mg tissue) than both obese (14.4 ± 1.6% conversion, p<0.01) and type 2 diabetes subjects (11.7 ± 1.9% conversion, p<0.05) in the fasting state. There was no effect of a meal on 11ß-HSD-1 activity in any of the three groups. The conclusions from this study are: 1) the variation coefficient for the ex vivo adipose tissue 11ß-HSD-1 activity method was ∼25% for repeat measures within subjects; 2) food intake had no major impact on enzyme activity; and 3) 11ß-HSD-1 activity in subcutaneous adipose tissue was significantly increased in obese subjects with or without T2DM compared to lean subjects without diabetes.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Abdome/patologia , Diabetes Mellitus Tipo 2/enzimologia , Comportamento Alimentar , Obesidade/enzimologia , Gordura Subcutânea/enzimologia , Magreza/enzimologia , Idoso , Antropometria , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/complicações , Jejum , Feminino , Glucose/metabolismo , Humanos , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Reprodutibilidade dos Testes , Gordura Subcutânea/patologia , Magreza/complicações
9.
Bioresour Technol ; 101(11): 3884-92, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20137925

RESUMO

In this work process water from a thermomechanical pulp mill was divided into five fractions by filtration and membrane filtration. Suspended matter was mainly isolated in the retentate from the drum filter, extractives in the microfiltration retentate, hemicelluloses in the ultrafiltration retentate and lignin in the nanofiltration retentate. The final water fraction was of fresh water quality. For each tonne of pulp produced, about 10kg of suspended matter, more than 0.3kg of extractives, 11kg of hemicelluloses and 8kg of aromatic compounds (lignin) could be recovered from the drum filtration retentate, the microfiltration retentate, the ultrafiltration retentate and the nanofiltration retentate, respectively. About 40% of the treated process water could be recovered as fresh water.


Assuntos
Resíduos Industriais , Papel , Indústria Têxtil , Poluentes da Água/isolamento & purificação , Ultrafiltração
10.
Torture ; 19(2): 88-101, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19920327

RESUMO

Lately, there has been a call to develop and assess efficacious mental health interventions for minors who have witnessed organized violence. This review outlines what is currently known about targeted and general school-based interventions for children and adolescents in war exposed countries. Seven empirical outcome studies were identified from a PubMed and PsychINFO search; four targeted and three general programmes. Despite the paucity of published evidence, some promising findings were noted. School-based interventions implemented by locally trained paraprofessionals in organized violence settings appear to be a feasible and low cost sustainable alternative to individualized therapy for distressed children in low and middle income countries. However, the reported outcomes for treatment effectiveness were mixed and suggest that school-based group crisis interventions for traumatized war exposed minors may not be sufficient to reduce mental distress and may sometimes even increase it. Several limitations in the published literature were observed. Although studies reported changes in symptoms associated with interventions, most did not report on the degree of functional impairment. Further, there may be a need to develop interventions targeting other dimensions of organized violence than post-traumatic distress, for example, depression and maladaptive grief. At this point in time it is difficult to compare targeted versus general interventions. There may be risks associated with screening minors, and studies should weigh the cost benefit of targeted versus broader treatment approaches. Future research should aim to determine which therapeutic ingredients, which could be professional-specific, such as manualized cognitive-behavioural therapy, culture-specific, or a combination, significantly contribute to positive outcomes.


Assuntos
Maus-Tratos Infantis , Saúde Mental , Refugiados , Serviços de Saúde Escolar/organização & administração , Guerra , Adolescente , Criança , Maus-Tratos Infantis/psicologia , Maus-Tratos Infantis/estatística & dados numéricos , Humanos , Internacionalidade , Refugiados/psicologia , Refugiados/estatística & dados numéricos , Serviços de Saúde Escolar/estatística & dados numéricos
11.
Aliment Pharmacol Ther ; 26(5): 665-72, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17697200

RESUMO

BACKGROUND: While empiric acid-suppressive therapy for uninvestigated dyspepsia patients with symptoms of epigastric pain or burning is standard practice, it is unknown whether an early response to therapy predicts outcome. AIM: To evaluate whether a 1-w acid suppression trial is effective for predicting 8-w response in such patients. METHODS: Helicobacter pylori-negative patients (aged 18-50 years) in primary care with uninvestigated epigastric pain or burning were randomized to esomeprazole 40 mg q.d.s. or b.d. for 1w, followed by esomeprazole 40 mg q.d.s. or placebo for 7w. Each day, patients rated the severity of their symptoms. RESULTS: Based on the last 3d, 1-w response rates were 39% (231 of 588) and 43% (258 of 596) with esomeprazole 40 mg q.d.s. and b.d., respectively. Based on the last 7d, response rates at 4w were 38% (283 of 738) and 25% (93 of 380) for esomeprazole and placebo, respectively, and 47% (339 of 716) and 34% (124 of 368), respectively, at 8w (both P < 0.001 vs. placebo). The sensitivity and specificity of esomeprazole treatment were 58% and 70%, respectively, at 8w. CONCLUSION: A 1-w acid suppression trial is of limited clinical value for predicting 8-w response in patients with symptoms of epigastric pain or burning. Esomeprazole provides greater symptom control than placebo at 4w and 8w.


Assuntos
Antiulcerosos/administração & dosagem , Dispepsia/tratamento farmacológico , Esomeprazol/administração & dosagem , Azia/prevenção & controle , Administração Oral , Adolescente , Adulto , Antiulcerosos/efeitos adversos , Relação Dose-Resposta a Droga , Esomeprazol/efeitos adversos , Feminino , Azia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Qualidade de Vida , Resultado do Tratamento
12.
Aliment Pharmacol Ther ; 26(5): 673-82, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17697201

RESUMO

BACKGROUND: Early identification of true responders to acid suppression in functional dyspepsia patients with symptoms of epigastric pain or burning may enable clinicians to optimally tailor treatment. AIM: To evaluate whether a 1-w acid suppression trial is useful for identifying true responders in this population. METHODS: Patients (18-70 years) were randomized to either esomeprazole 40 mg q.d.s., b.d. or placebo for 1w, and then esomeprazole 40 mg q.d.s. or placebo for 7w. Epigastric pain and/or burning were recorded on a 4-point scale (0 = none, 3 = severe). Trial-week response was defined as symptom score sum < or = 1 on last 3d of therapy; response at 8w was symptom score sum < or = 1 over preceding 7d. RESULTS: 1-w response rates were 33% (199 of 597), 29% (188 of 629) and 23% (71 of 315) with esomeprazole q.d.s., esomeprazole b.d. and placebo, respectively (P = 0.002 for esomeprazole groups vs. placebo). At 8w, trial week sensitivity and specificity were 46% and 80%, respectively, for esomeprazole (40 or 80 mg), and 33% and 87%, respectively, for placebo. The positive and negative predictive values for esomeprazole were 60% and 69%. CONCLUSION: Response to a 1-w acid suppression trial is of limited use for predicting symptom response at 8w in patients with unexplained epigastric pain or burning.


Assuntos
Dispepsia/tratamento farmacológico , Esomeprazol/administração & dosagem , Azia/prevenção & controle , Adolescente , Adulto , Idoso , Antiulcerosos/administração & dosagem , Antiulcerosos/efeitos adversos , Relação Dose-Resposta a Droga , Esomeprazol/efeitos adversos , Feminino , Seguimentos , Refluxo Gastroesofágico/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Qualidade de Vida , Sensibilidade e Especificidade , Resultado do Tratamento
13.
J Appl Microbiol ; 102(3): 826-37, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17309633

RESUMO

AIM: To investigate the potential of quorum sensing inhibitors (QSI) as food preservative agents in a food product, where bacterial spoilage is controlled by quorum sensing (QS). METHODS AND RESULTS: The effects of well-known QSI were tested on spoilage phenotypes and on QS-regulated genes of a bean sprout spoiling bacterial isolate (Pectobacterium A2JM) in laboratory substrates and in a bean sprout model system. The acylated homoserine lactones (AHL) analogues PenS-AHL and HepS-AHL decreased the specific protease activity of Pectobacterium A2JM in broth but did not reduce the expression of a QS-regulated secretion protein, and were without effect on soft rot of bean sprouts. The QSI ProS-AHL, furanone C-30, patulin, penicillic acid and 4-nitropyridine-N-oxide did not have any effect on protease activity, on gene expression or bean sprout appearance at nongrowth inhibitory concentrations. Extracts from garlic and bean sprouts induced the QS system of Pectobacterium in bean sprouts and a broth system, respectively. CONCLUSIONS: Among the several well-known QSI compounds, only PenS-AHL and HepS-AHL, inhibited QS-regulated protease activity of Pectobacterium A2JM in broth cultures, but had no effect on bean sprout spoilage. SIGNIFICANCE AND IMPACT OF THE STUDY: The QSI compounds must be selected in the specific system in which they are to function and they cannot easily be transferred from one QS system to another.


Assuntos
Microbiologia de Alimentos , Conservantes de Alimentos/farmacologia , Pectobacterium/efeitos dos fármacos , Phaseolus/microbiologia , Percepção de Quorum/efeitos dos fármacos , 4-Butirolactona/análogos & derivados , 4-Butirolactona/análise , 4-Butirolactona/farmacologia , Proteínas de Bactérias/genética , Óxidos N-Cíclicos/análise , Óxidos N-Cíclicos/farmacologia , Conservantes de Alimentos/análise , Furanos/análise , Furanos/farmacologia , Genes Bacterianos/genética , Mutação , Patulina/análise , Patulina/farmacologia , Pectobacterium/genética , Pectobacterium/crescimento & desenvolvimento , Ácido Penicílico/análise , Ácido Penicílico/farmacologia , Fenótipo , Percepção de Quorum/genética , Proteínas Repressoras/genética , Transativadores/genética , Fatores de Transcrição/genética
14.
Microbiology (Reading) ; 151(Pt 11): 3589-3602, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16272381

RESUMO

The function of LuxR homologues as quorum sensors is mediated by the binding of N-acyl-L-homoserine lactone (AHL) signal molecules to the N-terminal receptor site of the proteins. In this study, site-directed mutagenesis was carried out of the amino acid residues comprising the receptor site of LuxR from Vibrio fischeri, and the ability of the L42A, L42S, Y62F, W66F, D79N, W94D, V109D, V109T and M135A LuxR mutant proteins to activate green fluorescent protein expression from a P(luxI) promoter was measured. X-ray crystallographic studies of the LuxR homologue TraR indicated that residues Y53 and W57 form hydrogen bonds to the 1-carbonyl group and the ring carbonyl group, respectively, of the cognate AHL signal. Based on the activity and signal specificity of the LuxR mutant proteins, and on molecular modelling, a model is suggested in which Y62 (corresponding to Y53 in TraR) forms a hydrogen bond with the ring carbonyl group rather than the 1-carbonyl group, while W66 (corresponding to W57 in TraR) forms a hydrogen bond to the 1-carbonyl group. This flips the position of the acyl side chain in the LuxR/signal molecule complex compared to the TraR/signal molecule complex. Halogenated furanones from the marine alga Delisea pulchra and the synthetic signal analogue N-(sulfanylacetyl)-L-homoserine lactone can block quorum sensing. The LuxR mutant proteins were insensitive to inhibition by N-(propylsulfanylacetyl)-L-homoserine lactone. In contrast, the mutations had only a minor effect on the sensitivity of the proteins to halogenated furanones, and the data strongly suggest that these compounds do not compete in a 'classic' way with N-3-oxohexanoyl-L-homoserine lactone for the binding site. Based on modelling and experimental data it is suggested that these compounds bind in a non-agonist fashion.


Assuntos
4-Butirolactona/análogos & derivados , Escherichia coli/crescimento & desenvolvimento , Furanos/farmacologia , Regulação Bacteriana da Expressão Gênica , Proteínas Repressoras/química , Transdução de Sinais , Transativadores/química , 4-Butirolactona/metabolismo , Aliivibrio fischeri/genética , Aliivibrio fischeri/metabolismo , Substituição de Aminoácidos , Sítios de Ligação , Escherichia coli/genética , Escherichia coli/metabolismo , Furanos/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Modelos Moleculares , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transativadores/antagonistas & inibidores , Transativadores/genética , Transativadores/metabolismo
15.
Aliment Pharmacol Ther ; 21(4): 363-71, 2005 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-15709986

RESUMO

AIM: To assess the efficacy and safety of budesonide capsules 6 mg daily for prolongation of time to relapse and maintenance of remission in patients with Crohn's disease (CD) affecting the ileum and/or ascending colon. METHODS: In a double-blind, placebo-controlled, multicentre trial, 110 patients with CD, who had previously achieved remission in a placebo-controlled trial of budesonide 9 mg daily, were randomly assigned to receive budesonide 6 mg once daily or placebo for 52 weeks. Primary outcome measure was time to relapse [CD activity index (CDAI) of >150 plus an increase of at least 60 points from study entry or withdrawal due to clinical deterioration]. RESULTS: Median time to relapse was 360 days for budesonide patients; 169 days for placebo patients (P = 0.132). No significant differences were seen between groups in relapse rates at 1 year. Budesonide was safe and well tolerated, with a similar adverse events profile to placebo. CONCLUSION: Patients treated with budesonide 6 mg once daily had a trend towards a prolonged time to relapse and lower CDAI scores compared with patients treated with placebo, but relapse rates were not significantly different at the 1-year end point.


Assuntos
Anti-Inflamatórios/uso terapêutico , Budesonida/uso terapêutico , Doença de Crohn/tratamento farmacológico , Adolescente , Adulto , Idoso , Anti-Inflamatórios/efeitos adversos , Budesonida/efeitos adversos , Doença de Crohn/patologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Índice de Gravidade de Doença , Resultado do Tratamento
16.
Ann Rheum Dis ; 63(6): 688-95, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15140776

RESUMO

OBJECTIVES: To compare budesonide, a locally acting glucocorticoid with minimal systemic exposure, with conventional glucocorticoid treatment and placebo in rheumatoid arthritis. METHODS: A double blind, randomised, controlled trial over 12 weeks in 143 patients with active rheumatoid arthritis, comparing budesonide 3 mg daily, budesonide 9 mg daily, prednisolone 7.5 mg daily, and placebo. Particular attention was paid to the pattern of clinical response and to changes in the four week period following discontinuation of treatment. RESULTS: There were improvements in tender joint count and swollen joint count on budesonide 9 mg compared with placebo (28% for tender and 34% for swollen joint counts, p<0.05). Prednisolone 7.5 mg gave similar results, while budesonide 3 mg was less effective. ACR20 response criteria were met by 25% of patients on placebo, 22% on budesonide 3 mg, 42% on budesonide 9 mg, and 56% on prednisolone 7.5 mg. A rapid and significant reduction in symptoms and signs in response to budesonide 9 mg and prednisolone 7.5 mg was evident by two weeks and maximal at eight weeks. There was no evidence that budesonide provided a different pattern of symptom control from prednisolone, or that symptoms became worse than placebo treatment levels after discontinuation of glucocorticoid treatment. Adverse effects attributable to glucocorticoids were equally common in all groups. CONCLUSIONS: The symptomatic benefits of budesonide 9 mg and prednisolone 7.5 mg are achieved within a short time of initiating treatment, are maintained for three months, and are not associated with any rebound in symptoms after stopping treatment.


Assuntos
Anti-Inflamatórios/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Budesonida/uso terapêutico , Prednisolona/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antirreumáticos/uso terapêutico , Artrite Reumatoide/patologia , Budesonida/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prednisolona/efeitos adversos , Qualidade de Vida , Resultado do Tratamento
17.
Clin Exp Allergy ; 33(4): 531-7, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12680872

RESUMO

BACKGROUND: Eosinophils are seen at sites of inflammation in diseases such as helminthic infestation, asthma, ulcerative colitis and some neoplastic diseases. They are also associated with connective tissue remodelling, for example in longstanding asthma. In the present study, we investigated whether eosinophils express the CXC chemokine epithelial cell-derived neutrophil activating peptide (ENA-78/CXCL5), a chemokine that can activate neutrophils and in addition possesses angiogenic properties. Immunocytochemistry detected CXCL5 in eosinophils and the peptide was localized in the specific granules by immunoelectron microscopy. METHODS AND RESULTS: In eosinophil lysates, 12 +/- 2 pg (mean +/- SEM) of CXCL5 was detected per 106 cells by enzyme-linked immunosorbent assay (ELISA). Weak constitutive expression of CXCL5, as well as the related CXC chemokine IL-8/CXCL8, could be detected in freshly isolated eosinophils by RT-PCR. However, during prolonged incubation of eosinophils, a strong increase in both CXCL5 and IL-8/CXCL8 expression was seen, as detected by RT-PCR, and increasing amounts of CXCL5 peptide with time were detected in the incubation medium by ELISA. Addition of TNF-alpha neutralizing antibodies during prolonged incubation significantly inhibited CXCL5 production, demonstrating involvement of auto- and paracrine effects from TNF-alpha produced by eosinophils themselves. Addition of IFN-gamma showed a strong inhibitory effect on CXCL5 synthesis. CONCLUSION: These findings suggest that, through expression of CXCL5, eosinophils can recruit and activate CXC receptor 2 (CXCR2)-bearing cells such as neutrophils at sites of inflammation. Eosinophils may also promote connective tissue remodelling through release of this peptide.


Assuntos
Quimiocinas CXC , Eosinófilos/imunologia , Hipersensibilidade/imunologia , Interleucina-8/análogos & derivados , Interleucina-8/análise , Ativação de Neutrófilo , Células Cultivadas , Quimiocina CXCL5 , Meios de Cultivo Condicionados , Expressão Gênica , Humanos , Imuno-Histoquímica/métodos , Hibridização In Situ/métodos , Interleucina-1/farmacologia , Interleucina-8/genética , Microscopia Imunoeletrônica , RNA/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/farmacologia
18.
Aliment Pharmacol Ther ; 17(1): 85-92, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12492736

RESUMO

BACKGROUND: Systemic glucocorticosteroid therapy is effective in Crohn's disease, but is associated with side-effects. Budesonide has high topical anti-inflammatory activity, but considerably lower systemic activity than other oral glucocorticosteroids. AIM: To evaluate the systemic exposure to budesonide (controlled ileal release capsules) in children and adults with active Crohn's disease, and to assess the suppression of plasma cortisol. METHODS: In an open label study, patients (eight children and six adults) with active Crohn's disease received 9 mg budesonide (Entocort capsules) orally once daily for 7 days. Plasma concentrations were determined on the seventh day of administration, and pharmacokinetic parameters were calculated. For reference, 0.5 mg budesonide was given intravenously separately. Plasma cortisol levels were compared with the pre-treatment baseline values. RESULTS: Systemic exposure to budesonide (AUC0-24 h) after 1 week of oral administration was 41 +/- 21 nmol/L x h (mean +/- s.d.) in children and 35 +/- 20 nmol/L x h in adults. The estimated systemic availability in children was 9 +/- 5% and in adults 11 +/- 7%. The mean plasma cortisol (AUC0-24 h) decreased by 64 +/- 18% in children and by 50 +/- 27% in adults. CONCLUSIONS: The systemic exposure, systemic availability and cortisol suppression after oral administration of 9 mg budesonide were similar in children and adults with active Crohn's disease. Budesonide was well tolerated and no clinically important safety-related findings were identified.


Assuntos
Anti-Inflamatórios/farmacocinética , Budesonida/farmacocinética , Doença de Crohn/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Budesonida/administração & dosagem , Budesonida/efeitos adversos , Cápsulas , Criança , Doença de Crohn/sangue , Preparações de Ação Retardada , Feminino , Humanos , Hidrocortisona/sangue , Infusões Intravenosas , Masculino
20.
Aliment Pharmacol Ther ; 16(8): 1519-27, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12182752

RESUMO

BACKGROUND: A high prevalence of osteoporosis has been noted in Crohn's disease, but data about fractures are scarce. METHODS: The relationship between low bone mineral density and the prevalence of vertebral fractures was studied in 271 patients with ileo-caecal Crohn's disease in a large European/Israeli study. One hundred and eighty-one currently steroid-free patients with active Crohn's disease (98 completely steroid-naive) and 90 steroid-dependent patients with inactive or quiescent Crohn's disease were investigated by dual X-ray absorptiometry scan of the lumbar spine, a standardized posterior/anterior and lateral X-ray of the thoracic and lumbar spine, and an assessment of potential risk factors for osteoporosis. RESULTS: Thirty-nine asymptomatic fractures were seen in 25 of 179 steroid-free patients (14.0%; 27 wedge, 12 concavity), and 17 fractures were seen in 13 of 89 steroid-dependent patients (14.6%; 14 wedge, three concavity). The prevalence of fractures in steroid-naive patients was 12.4%. The average bone mineral density, expressed as the T-score, of patients with fractures was not significantly different from that of those without fractures (-0.759 vs. -0.837; P=0.73); 55% of patients with fractures had a normal T-score. The bone mineral density was negatively correlated with lifetime steroids, but not with previous bowel resection or current disease activity. The fracture rate was not correlated with the bone mineral density (P=0.73) or lifetime steroid dose (P=0.83); in women, but not in men, the fracture rate was correlated with age (P=0.009). CONCLUSIONS: The lack of correlation between the prevalence of fractures on the one hand and the bone mineral density and lifetime steroid dose on the other necessitates new hypotheses for the pathogenesis of the former.


Assuntos
Doença de Crohn/complicações , Fraturas Espontâneas/etiologia , Osteoporose/complicações , Fraturas da Coluna Vertebral/etiologia , Absorciometria de Fóton , Adulto , Distribuição por Idade , Idoso , Anti-Inflamatórios/efeitos adversos , Densidade Óssea , Doença de Crohn/tratamento farmacológico , Europa (Continente)/epidemiologia , Feminino , Fraturas Espontâneas/epidemiologia , Fraturas Espontâneas/fisiopatologia , Glucocorticoides/efeitos adversos , Humanos , Israel/epidemiologia , Masculino , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Prevalência , Fatores de Risco , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/fisiopatologia , Esteroides
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...