RESUMO
To reduce errors in portion size estimation, a number of aids have been developed and tested. This systematic review synthesizes what is known about error associated with use of different portion size estimation aids (PSEAs) within self-reported dietary recall studies in children (aged ≤18 years). Eight electronic databases were searched using relevant keywords. From 8184 records identified and screened, 327 full texts were retrieved, with 10 records representing 9 studies meeting inclusion criteria. Studies using proxy reporting were excluded. Thirteen PSEAs were identified. To facilitate comparisons between different types of aids they were categorized into 'physical 2-dimensional (2D)', 'digital 2D' and '3-dimensional' PSEAs. Seven were physical 2D (e.g. food atlas), two were digital 2D (i.e. computer-based), and four were 3D (e.g. modelling clay, household items). Comparisons of PSEAs within studies found the smallest estimation errors for digital 2D and largest for 3D aids. Errors in relation to food type were varied, with portions of amorphous foods overestimated in multiple studies. No effects for recall interval time or sex were identified. One study reported a significant improvement in estimation error with increasing age. Across studies, large variations in study design and reporting of estimation error hindered the synthesis of evidence regarding the influence of different types of PSEAs on accuracy. While a definitive conclusion about the most accurate PSEA could not be drawn, a check-list to guide future PSEA development and testing has been proposed in the current review. This will assist comparability with future studies of PSEAs for children facilitate development of more accurate PSEAs in the future.
Assuntos
Comportamento Alimentar/psicologia , Rememoração Mental , Tamanho da Porção/psicologia , Estatística como Assunto/métodos , Adolescente , Criança , Inquéritos sobre Dietas , Feminino , Humanos , Masculino , Autorrelato , Percepção de TamanhoRESUMO
BACKGROUND: Epidemiologic evidence on the influence of dietary glycemic index (GI) and glycemic load (GL) on the development of obesity is limited. OBJECTIVE: This prospective study examined the associations between dietary GI and GL and changes in body composition measures during adolescence. DESIGN: In a representative sample of Northern Irish adolescents aged 12 years at baseline and 15 years at follow-up (n=426), dietary intake was assessed by a diet history interview. Body composition measures included body mass index (BMI; kg m(-2)), BMI z-score, sum of four skinfold thicknesses, percentage body fat, fat mass index (FMI; kg m(-2)) and fat-free mass index (kg m(-2)). RESULTS: After adjustment for potential confounding factors, baseline GI was associated with increased change in FMI. Mean (95% confidence interval) values of changes in FMI according to tertiles of baseline GI were 0.41 (0.25, 0.57), 0.42 (0.26, 0.58) and 0.67 (0.51, 0.83) kg m(-2), respectively (P for trend=0.03). There was no significant association of baseline GI with changes in other body composition measures (P for trend≥0.054). Conversely, baseline GL showed no association with changes in any of the measures (P for trend≥0.41). Furthermore, changes in GI or GL were not associated with changes in any of the measures (P for trend≥0.16). CONCLUSION: Dietary GI at age 12 years was independently associated with increased change in FMI between ages 12 and 15 years in a representative sample from Northern Ireland, whereas dietary GL showed no association with changes in any of the body composition measures examined.
Assuntos
Glicemia/metabolismo , Composição Corporal , Carboidratos da Dieta/metabolismo , Ingestão de Energia , Índice Glicêmico , Puberdade/metabolismo , Adolescente , Composição Corporal/fisiologia , Índice de Massa Corporal , Criança , Dieta , Feminino , Seguimentos , Humanos , Resistência à Insulina , Masculino , Irlanda do Norte , Obesidade/metabolismo , Obesidade/fisiopatologia , Obesidade/prevenção & controle , Estudos Prospectivos , Puberdade/fisiologia , Fatores de Risco , Dobras CutâneasRESUMO
OBJECTIVE: To compare portion size (PS) estimates, perceived energy density (ED) and anticipated consumption guilt (ACG) for healthier vs standard foods. METHODS: Three pairs of isoenergy dense (kJ per 100 g) foods-healthier vs standard cereals, drinks and coleslaws-were selected. For each food, subjects served an appropriate PS for themselves and estimated its ED. Subjects also rated their ACG about eating the food on a scale of 1 (not at all guilty) to 5 (very guilty). RESULTS: Subjects (n=186) estimated larger portions of the healthier coleslaw than that of the standard version, and perceived all healthier foods to be lower in ED than their standard alternatives, despite being isoenergy dense. Higher ACG was associated with the standard foods. Portion estimates were generally larger than recommendations and the ED of the foods was underestimated. CONCLUSIONS: The larger portions selected for the 'reduced fat' food in association with lower perceived ED and ACG suggests that such nutrition claims could be promoting inappropriate PS selection and consumption behaviour. Consumer education on appropriate portions is warranted to correct such misconceptions.
Assuntos
Comércio , Ingestão de Energia , Comportamento Alimentar/psicologia , Tamanho da Porção , Saúde Pública , Adulto , Comportamento do Consumidor , Comparação Transcultural , Europa (Continente) , Feminino , Indústria Alimentícia , Preferências Alimentares , Alimentos Fortificados , Alimentos Orgânicos , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Fenômenos Fisiológicos da Nutrição , Valor Nutritivo , Percepção , Tamanho da Porção/psicologia , Estados UnidosRESUMO
BACKGROUND: The present study aimed to compare the nutritional quality (NQ) and energy costs (EC) (£ MJ(-1) ) of own brand (OB) versus market brand (MB) foods in 2010 and 2012. METHODS: A list of processed foods (n = 32) was identified based on the most frequently consumed foods in the UK. Total fat, saturated fat, sugars, salt and energy density (ED) (kJ g(-1) ) in 2010 and 2012 were compared for six OB and one MB version of each food using a NQ scoring method based on the Food Standards Agency's Traffic Light System (TLS). Additional information (fruit, vegetable and nut content; protein; fibre and sodium) was recorded in 2012, and NQ was assessed using the Food Standards Agency's nutrient profiling model (NPM). The EC of the food baskets (FB) was compared in 2010 and 2012. RESULTS: There were no differences in overall NQ between OB and MB FB in 2010 (TLS, P = 0.978) or 2012 (TLS, P = 0.840; NPM, P = 0.696). However, the MB FB was highest in EC in 2010 and 2012 (both P < 0.001). There was an inverse relationship between the ED and EC of the MB foods in 2010 (r = -0.484; P = 0.005) and 2012 (r = -0.452; P = 0.009). CONCLUSIONS: The MB FB was higher in EC than the OB FB in 2010 and 2012 but not superior in overall NQ based on both the TLS and NPM.
Assuntos
Comércio , Ingestão de Energia , Fast Foods , Abastecimento de Alimentos , Valor Nutritivo , Fibras na Dieta , Fast Foods/economia , Fast Foods/normas , Abastecimento de Alimentos/economia , Abastecimento de Alimentos/normas , Humanos , Sódio na DietaRESUMO
OBJECTIVE: To investigate the effect of Olibra fat emulsion on medium-term food intake and appetite in non-obese subjects. DESIGN: Double-blind, placebo-controlled, within-subject crossover. SETTING: University of Ulster, Coleraine. SUBJECTS: A total of 28 subjects (14 male, 14 female). INTERVENTIONS: Subjects were randomly assigned to receive either a 200 g portion of test (5 g of Olibra fat) or control (5 g milk fat) yoghurt for breakfast for 2 x 3 week 'study' phases, separated by a 3-week 'wash-out' phase. On days 1, 8 and 22 of the study phases, food intake 4 h post-consumption of the yoghurt was assessed by pre- and post-covert weighing at an ad libitum buffet-style test lunch. Throughout each of these study days, appetite was assessed using visual analogue scales (VAS) at regular intervals. For the remainder of the study days, and the following 24 h ('post-study days'), subjects reported their food intake using weighed dietary records. RESULTS: Consumption of the Olibra emulsion had no significant effect on mean energy, macronutrient or amounts of food consumed at the lunch 4 h post-consumption. Self-reported food intakes indicated that there was no significant effect of the emulsion on energy intakes for the remainder of each study day and post-study days. There was considerable individual variation in food intakes following consumption of the Olibra emulsion, with 46, 59 and 57% of subjects reducing their energy intakes at lunch on days 1, 8 and 22. There was no consistent effect of the emulsion on appetite ratings. CONCLUSIONS: In contrast to earlier studies, there was no evidence of a short- or medium-term effect of the Olibra emulsion on food intake or appetite. This could be owing to numerous confounding factors influencing eating behaviour and/or the different study design used in the present study.
Assuntos
Apetite/efeitos dos fármacos , Gorduras na Dieta/administração & dosagem , Ingestão de Energia/efeitos dos fármacos , Adulto , Apetite/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Emulsões , Ingestão de Energia/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Fatores de Tempo , IogurteRESUMO
OBJECTIVE: To provide an overview of methodological issues in the design, delivery and evaluation of childhood obesity prevention programmes. DESIGN: Review of existing literature. SETTING: International. RESULTS: Interventions have varied considerably with regard to their design, subject selection criteria, sample size, attrition rates, intervention components and duration of both the intervention and the follow-up phases. However, overall, there is only a limited body of consistent, high-quality evidence on which valid and generalisable conclusions can be drawn about best practices for the prevention of childhood obesity. CONCLUSIONS: Although the rationale for targeting children and adolescents through primary prevention is now compelling, effective obesity prevention remains elusive. There is increasing consensus that prevention of childhood obesity necessitates multifaceted health promotion interventions based on population health principles. By definition, such interventions should have a range of outcome indicators of effectiveness, generalisability and sustainability, not just the traditional ones focused on individual lifestyle behaviour change. Given the complexity and intricacy of population-based intervention programmes, multiple methods of data collection which combine both qualitative and quantitative approaches will need to be fully exploited in order to move towards evidence-based practice in the future.
Assuntos
Promoção da Saúde/métodos , Obesidade/prevenção & controle , Prevenção Primária/métodos , Adolescente , Criança , Medicina Baseada em Evidências , Humanos , Avaliação de Programas e Projetos de Saúde , Pesquisa , Características de ResidênciaRESUMO
Atherosclerotic lesions may progress due to a "failure to die" by vascular repair cells. Egr-1, a zinc finger transcription factor, is elevated more than 5-fold in human carotid lesions relative to the adjacent tunica media. Lesion cells in vitro also express 2-3-fold higher Egr-1 mRNA and protein levels but express much lower levels of the transforming growth factor-beta (TGF-beta) Type II receptor (TbetaR-2) and are functionally resistant to the antiproliferative effects of TGF-beta. Lesion cells fail to express a TbetaR-2 promoter/chloramphenicol acetyltransferase (CAT) construct but overexpress an Egr-1-inducible platelet-derived growth factor-A promoter/CAT construct. Transfection of Egr-1 cDNA represses TbetaR-2/CAT constructs but induces PDGF-A/CAT. Egr-1 transfection reduces the levels of TbetaR-2 and confers resistance to the antiproliferative effect of TGF-beta1. Egr-1 can interact directly with both the -143 Sp1 site and the positive regulatory element 2 (PRE2) (ERT/ets) region of the TbetaR-2 promoter. Thus, although activating a family of stress-responsive genes, Egr-1 also transcriptionally represses one of the major inhibitory pathways that restrains vascular repair.
Assuntos
Arteriosclerose/metabolismo , Proteínas de Ligação a DNA/biossíntese , Proteínas Imediatamente Precoces , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Fatores de Transcrição/biossíntese , Artérias/metabolismo , Sítios de Ligação , Western Blotting , Divisão Celular , Núcleo Celular/metabolismo , Células Cultivadas , Cloranfenicol O-Acetiltransferase/metabolismo , Clonagem Molecular , DNA Complementar/metabolismo , Densitometria , Relação Dose-Resposta a Droga , Proteína 1 de Resposta de Crescimento Precoce , Fator 2 de Crescimento de Fibroblastos/metabolismo , Genes Reporter , Humanos , Fator de Crescimento Neural/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases , RNA/metabolismo , RNA Mensageiro/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo II , Proteínas Recombinantes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Transcrição Gênica , Transfecção , Veias/metabolismo , Dedos de ZincoRESUMO
Based on diverse evidence in animals and humans, it has been hypothesized that atherosclerosis, and other injury-induced hyperplasias such as restenosis, may result from a failure in endogenous inhibitory systems that normally limit wound repair and induce regression of wound repair cells. A key defect in one of these inhibitory pathways, the TGF-beta system, has been identified and characterized in both animal models and in human lesions and lesion-derived cells. Cells derived from human lesions are resistant to the antiproliferative and apoptotic effects of TGF-beta, while their normal counterparts from the vascular media are potently inhibited and killed. Both cell types increase PAI-1 production, switch actin phenotypes in response to TGF-beta1, and produce similar levels of TGF-beta activity. Membrane cross-linking of (125)I-TGF-beta1 indicates that normal human SMC express Type I, II and III receptors. The Type II receptor is strikingly decreased in lesion cells, with little change in the Type I or III receptors. RT-PCR confirmed that the Type II TGF-beta1 receptor mRNA is reduced in lesion cells. Subsequent analysis of human lesion vs normal tissues confirmed that the Type I receptor was consistently present in the lesion, while the Type II receptor was much more variable, and commonly absent in both coronary artery and carotid artery lesions. Transfection of the Type II receptor into lesion cells partially restores the growth inhibitory response to TGF-beta1, implying that signaling remains intact. A subset of patients, and cells derived from their lesions, exhibit acquired mutations in the Type II receptor that would explain their resistance, though the majority of cells are resistant without obvious mutational defects. Thus, it is currently being tested whether transcriptional defects or abnormalities in receptor processing may explain the low levels of the Type II receptor. Because TGF-beta1 is overexpressed in fibroproliferative vascular lesions, receptor-negative cells would be allowed to grow in a slow, but uncontrolled fashion, while overproducing extracellular matrix components.
Assuntos
Receptores de Ativinas Tipo I , Arteriosclerose/metabolismo , Arteriosclerose/fisiopatologia , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Envelhecimento/fisiologia , Angioplastia , Animais , Arteriosclerose/cirurgia , Constrição Patológica , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Humanos , Mutação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , RNA Mensageiro/análise , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Fator de Crescimento Transformador beta/farmacologiaRESUMO
PURPOSE: Although 60% to 80% of the mature intimal hyperplastic plaque is composed of extracellular matrix (ECM) proteins, little is known about the factors that stimulate smooth muscle cells (SMCs) to produce these proteins. A major component of the ECM protein is fibronectin. Thus we studied fibronectin production and its response to various growth factors, cytokines, and other ECM proteins that are released at the time of vascular injury. METHODS: Quiescent cultured human SMCs were stimulated for varying intervals with increasing concentrations of agonist. Fibronectin in the cell medium was assayed by immunoblotting with a fibronectin-specific antibody. RESULTS: After 72 hours of stimulation, transforming growth factor-beta (10 ng/mL) had the most profound effect on fibronectin production (9.6- +/- 2.1-fold; P <.05), followed by epidermal growth factor (100 ng/mL; 5.0- +/- 0.1-fold; P <.05, for both). Surprisingly, the platelet-derived growth factors (AA, AB, and BB) and fibroblast growth factor did not stimulate fibronectin production. Among the matrix proteins studied, only collagen type I (20 microg/mL) stimulated fibronectin production (1.9- +/- 0.1-fold; P <.05), whereas collagen type IV and laminin had no effect. The contractile protein angiotensin II (100 ng/mL) was a weak stimulant of fibronectin (1.6- +/- 0.2-fold; P <.05). Time course studies of fibronectin production up to 72 hours revealed kinetics that varied with each agonist. Transforming growth factor-beta stimulated significant early production of fibronectin, whereas fibronectin production in response to epidermal growth factor and collagen type I was initially modest but increased with time. The effect of angiotensin II did not become evident until 72 hours. CONCLUSION: Cytokines, growth factors, and matrix proteins have varying quantitative effects on ECM protein production by human vascular SMCs. Knowledge of the factors that influence ECM protein production may allow for the design of specific inhibitors that can prevent intimal hyperplasia.
Assuntos
Citocinas/farmacologia , Proteínas da Matriz Extracelular/farmacologia , Fibronectinas/biossíntese , Substâncias de Crescimento/farmacologia , Músculo Liso Vascular/metabolismo , Células Cultivadas , Meios de Cultura , Fibronectinas/agonistas , Humanos , Immunoblotting , Músculo Liso Vascular/citologiaRESUMO
To understand the mRNA transcript profile in the human atherosclerotic lesion, RNA was prepared from the fibrous cap versus adjacent media of 13 patients undergoing carotid endarterectomy. cDNA expression arrays bearing 588 known genes indicated that lesions express unexpectedly high levels of the early growth response gene, Egr-1 (NGFI-A), a zinc-finger transcription factor that modulates a cluster of stress-responsive genes including PDGF and TGF-beta. Expression of Egr-1 was an average of 5-fold higher in the lesion than in the adjacent media, a result confirmed by RT-PCR, and many Egr-1-inducible genes were also strongly elevated in the lesion. Time-course analyses revealed that Egr-1 was not induced ex vivo. Immunocytochemistry indicated that Egr-1 was expressed prominently in the smooth muscle-actin positive cells, particularly in areas of macrophage infiltration, and in other cell types, including endothelial cells. Induction of atherosclerosis in LDL receptor-null mice by feeding them a high-fat diet resulted in a progressive increase in Egr-1 expression in the aorta. Thus, induction of Egr-1 by atherogenic factors may be a key step in coordinating the cellular events that result in vascular lesions.
Assuntos
Arteriosclerose/genética , Proteínas de Ligação a DNA/genética , Proteínas Imediatamente Precoces , Músculo Liso Vascular/patologia , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , Animais , Arteriosclerose/patologia , Proteínas de Ligação a DNA/metabolismo , Dieta Aterogênica , Proteína 1 de Resposta de Crescimento Precoce , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Receptores de LDL/genética , Fatores de Transcrição/metabolismoRESUMO
Polycyclic aromatic hydrocarbons, such as benzo[a]pyrene (B[a]P) present in tobacco smoke and tar, have been implicated in the development of atherosclerosis as well as cancer. Increased expression of cyclooxygenase-2 (COX-2) has been detected both in atherosclerotic lesions and in epithelial cancers. To determine whether polycyclic aromatic hydrocarbons might directly affect COX expression in vascular cells, we investigated the effects of B[a]P on COX-2 expression in human and rat arterial smooth muscle cells (SMC). Treatment with B[a]P increased levels of COX-2 protein and mRNA and enhanced prostaglandin synthesis. Nuclear runoff assays and transient transfections revealed increased COX-2 gene transcription after treatment with B[a]P. Experiments were done to define the signaling mechanism by which B[a]P induced COX-2. B[a]P caused a rapid increase in phosphorylation of extracellular signal-regulated kinase (ERK); pharmacologic inhibition of mitogen-activated protein kinase kinase blocked B[a]P-mediated induction of COX-2. Depletion of the intracellular antioxidant, glutathione, with buthionine sulfoximine significantly increased B[a]P-mediated induction of COX-2 while exposure to N-acetylcysteine, a precursor of glutathione, suppressed the induction of COX-2 by B[a]P. Several lines of evidence suggest that the induction of COX-2 by B[a]P is mediated, at least in part, by NF-kappaB. Treatment with B[a]P increased binding of NF-kappaB to DNA. Moreover, B[a]P-mediated stimulation of COX-2 promoter activity was blocked when a construct containing a mutagenized NF-kappaB site was used. Pharmacological inhibitors of NF-kappaB blocked the induction of COX-2 protein and the stimulation of COX-2 promoter activity by B[a]P. Taken together, these data are likely to be important for understanding the atherogenic effects of tobacco smoke.
Assuntos
Benzo(a)pireno/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Isoenzimas/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , NF-kappa B/metabolismo , Prostaglandina-Endoperóxido Sintases/genética , Transcrição Gênica/efeitos dos fármacos , Animais , Sequência de Bases , Ciclo-Oxigenase 2 , Primers do DNA , Humanos , Proteínas de Membrana , Músculo Liso Vascular/citologia , Músculo Liso Vascular/enzimologia , Estresse Oxidativo , RatosRESUMO
The degree of cellularity in vascular lesions is determined by the balance between the migration and proliferation of cells relative to their rate of egress and apoptosis. Transforming growth factor-beta(1) can act as a potent antiproliferative and apoptotic factor for proliferating vascular cells. Our laboratory has previously identified cells cultured from human vascular lesions that are resistant to the antiproliferative effect of TGF-beta(1) due to an acquired mutation in the Type II receptor for TGF-beta(1). In the present studies, the expression of the Type I and II receptors in coronary and carotid atherosclerotic lesions was analysed by immunostaining, RT-PCR, and in situ RT-PCR. Levels of the Type I and Type II receptors varied widely within lesions, with the highest levels in the fibrous cap and at discrete foci within the lesion. Regions of smooth muscle-like cells (SMC) were commonly found that were Type I positive but Type II receptor negative. In 43 cell lines cultured from 126 human lesions, 84% of the lesion-derived cell (LDC) cultures exhibited functional resistance to the antiproliferative effect of TGF-beta(1). This resistance was conferred against TGF-beta(1), TGF-beta(2), and TGF- beta(3), but not interferon-gamma or mimosine. While normal SMC exhibited a four-fold increase in the rate of apoptosis after TGF- beta(1) treatment, most LDC were resistant to apoptosis in response to TGF-beta(1). Resistant cells exhibited selective loss of Type II receptor expression, and retroviral transfection of Type II receptor cDNA partially corrected the functional deficit. Thus, resistance to apoptosis may lead to the slow proliferation of resistant cell subsets, thereby contributing to the progression of atherosclerotic and restenotic lesions.
Assuntos
Receptores de Ativinas Tipo I , Arteriosclerose/patologia , Estenose das Carótidas/patologia , Estenose das Carótidas/fisiopatologia , Doença das Coronárias/patologia , Doença das Coronárias/fisiopatologia , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Apoptose , Arteriosclerose/genética , Arteriosclerose/fisiopatologia , Aterectomia , Estenose das Carótidas/genética , Divisão Celular/efeitos dos fármacos , Clonagem Molecular , Doença das Coronárias/genética , Endarterectomia das Carótidas , Humanos , Imuno-Histoquímica , Modelos Cardiovasculares , RNA Mensageiro/genética , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Proteínas Recombinantes/biossíntese , Recidiva , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica , Transfecção , Fator de Crescimento Transformador beta/farmacologiaRESUMO
This study assessed safety of the distal occlusion washout (DOW) method for prevention of no-reflow during stenting of degenerated saphenous vein grafts (SVGs). The DOW method involves protection of distal native coronary circulation with an occlusive balloon during the pretreatment and washout steps prior to stenting. Outcomes of stenting of 23 grafts in 21 patients after pretreatment with the DOW method were evaluated. The mean graft age was 7.4 +/- 4.3 years. The mean treated lesion length was 53 +/- 28 mm. Total occlusions were treated in 6 grafts and thrombotic lesions in 10 nontotally occluded grafts. One non-Q-wave MI and one acute stent thrombosis were observed. No deaths, Q-wave MIs, or subacute thromboses occurred. Follow-up in 18/21 (85.7%) patients at 28 +/- 8 weeks demonstrated target graft revascularization in 1 (5%) patient. The DOW method prevented clinically significant no-reflow in all 23 degenerated SVGs stented.
Assuntos
Angioplastia Coronária com Balão/métodos , Doença das Coronárias/terapia , Oclusão de Enxerto Vascular/terapia , Veia Safena/transplante , Stents , Idoso , Angiografia Coronária , Circulação Coronária , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/fisiopatologia , Feminino , Filtração , Oclusão de Enxerto Vascular/diagnóstico por imagem , Oclusão de Enxerto Vascular/fisiopatologia , Humanos , Masculino , Estudos Prospectivos , Veia Safena/diagnóstico por imagem , Veia Safena/fisiopatologia , Irrigação Terapêutica , Resultado do TratamentoRESUMO
Mechanisms that control the balance between cell proliferation and death are important in the development of vascular lesions. Rat primary smooth muscle cells were 80% inhibited by low microgram doses of hydrocortisone (HC) and 50% inhibited by nanogram concentrations of transforming growth factor-beta1 (TGF-beta1), although some lines acquired resistance in late passage. However, comparable doses of HC, or TGF-beta1, failed to inhibit most human lesion-derived cell (LDC) lines. In sensitive LDC, HC (10 microg/mL) inhibited proliferation by up to 50%, with obvious apoptosis in some lines, and TGF-beta1 inhibited proliferation by more than 90%. Collagen production, as measured by [3H]proline incorporation or RIA for type III pro-collagen, was either unaffected or increased in the LDCs by HC. These divergent responses between LDC lines were partially explained by the absence of the glucocorticoid receptor (GR) and heat shock protein 90 mRNA in 10 of 12 LDC lines, but the presence of the mineralocorticoid receptor and 11beta-hydroxysteroid dehydrogenase type II. Western blot analysis confirmed the absence of the GR protein in cells lacking GR mRNA. Immunohistochemistry of human carotid lesions showed high levels of GR in the tunica media, but large areas lacking GR in the fibrous lesion. Considering the absence of the GR in most lines, the effects of HC may be elicited through the mineralocorticoid receptor. Functional resistance to the antiproliferative and antifibrotic effects of HC may contribute to excessive wound repair in atherosclerosis and restenosis.
Assuntos
Arteriosclerose/patologia , Regulação para Baixo , Hidrocortisona/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Receptores de Glucocorticoides/deficiência , Fator de Crescimento Transformador beta/farmacologia , 11-beta-Hidroxiesteroide Desidrogenases , Animais , Apoptose/efeitos dos fármacos , Arteriosclerose/metabolismo , Arteriosclerose/cirurgia , Artérias Carótidas/patologia , Artérias Carótidas/cirurgia , Lesões das Artérias Carótidas , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Replicação do DNA/efeitos dos fármacos , Resistência a Medicamentos , Endarterectomia , Indução Enzimática , Artéria Femoral/lesões , Artéria Femoral/patologia , Artéria Femoral/cirurgia , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP90/biossíntese , Proteínas de Choque Térmico HSP90/deficiência , Proteínas de Choque Térmico HSP90/genética , Humanos , Hidroxiesteroide Desidrogenases/análise , Artéria Ilíaca/lesões , Artéria Ilíaca/patologia , Artéria Ilíaca/cirurgia , Masculino , Músculo Liso Vascular/metabolismo , Pró-Colágeno/biossíntese , Pró-Colágeno/genética , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos F344 , Receptores de Glucocorticoides/biossíntese , Receptores de Glucocorticoides/genética , Receptores de Mineralocorticoides/análise , Recidiva , Especificidade da EspécieRESUMO
Transforming growth factor-beta (TGF-beta) is a profibrotic cytokine which has been implicated in the renal fibrosis which follows unilateral ureteral obstruction (UUO) in the rat. TGF-beta receptor type I (TGF-RI) and TGF-beta receptor type II (TGF-RII) are part of the complex which mediates the response to TGF-beta. We sought to determine if TGF-RI and TGF-RII are found in the kidney, and if their expression is changed as a result of UUO. Polymerase chain reaction (PCR) was used to determine expression of mRNA for TGF-RI and TGF-RII in the kidney. Immunoperoxidase was used to localize and quantify the expression of these receptors at 3, 7, 14, 21 and 28 days after UUO, and in sham-operated animals. Expression of mRNA for TGF-RI and TGF-RII was demonstrated in sham operated, obstructed and contralateral unobstructed kidneys using PCR. Using immunoperoxidase, a uniform distribution of TGF-RI and TGF-RII was found in cortical tubules of sham operated kidneys, whereas medullary tubules showed a patchy TGF-RI distribution and no TGF-RII staining. After UUO, an increased tubular expression of TGF-RI and TGF-RII was noted in both obstructed and contralateral kidneys compared to sham operated kidneys. No staining for either TGF-RI or TGF-RII was noted in glomeruli, vasculature or interstitial cells. TGF-beta receptors I and II were found exclusively in renal tubules and were shown to increase in both the obstructed and contralateral kidneys relative to sham operated animals. Upregulation of TGF-beta receptors in both kidneys suggests that TGF-beta may contribute to the fibrotic response in the obstructed kidney and the hypertrophic response of the contralateral kidney.
Assuntos
Expressão Gênica , Túbulos Renais/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Obstrução Ureteral/metabolismo , Actinas/genética , Animais , Técnicas Imunoenzimáticas , Córtex Renal/química , Medula Renal/química , Túbulos Renais/química , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Ratos , Ratos Sprague-DawleyRESUMO
Cells proliferating from human atherosclerotic lesions are resistant to the antiproliferative effect of TGF-beta1, a key factor in wound repair. DNA from human atherosclerotic and restenotic lesions was used to test the hypothesis that microsatellite instability leads to specific loss of the Type II receptor for TGF-beta1 (TbetaR-II), causing acquired resistance to TGF-beta1. High fidelity PCR and restriction analysis was adapted to analyze deletions in an A10 microsatellite within TbetaR-II. DNA from lesions, and cells grown from lesions, showed acquired 1 and 2 bp deletions in TbetaR-II, while microsatellites in the hMSH3 and hMSH6 genes, and hypermutable regions of p53 were unaffected. Sequencing confirmed that these deletions occurred principally in the replication error-prone A10 microsatellite region, though nonmicrosatellite mutations were observed. The mutations could be identified within specific patches of the lesion, while the surrounding tissue, or unaffected arteries, exhibited the wild-type genotype. This microsatellite deletion causes frameshift loss of receptor function, and thus, resistance to the antiproliferative and apoptotic effects of TGF-beta1. We propose that microsatellite instability in TbetaR-II disables growth inhibitory pathways, allowing monoclonal selection of a disease-prone cell type within some vascular lesions.
Assuntos
Arteriosclerose/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Arteriosclerose/patologia , Aterectomia , Sequência de Bases , Células Cultivadas , Vasos Coronários , Humanos , Artéria Torácica Interna , Repetições de Microssatélites , Mutação , Proteínas Serina-Treonina Quinases , Receptor do Fator de Crescimento Transformador beta Tipo II , Fatores de RiscoRESUMO
Chronic unilateral ureteral obstruction (UUO) results in interstitial fibrosis and nephron damage associated with irreversible loss of function. Collagen is increased in UUO, but detailed studies of rat renal extracellular matrix changes in UUO have not been carried out. Acute (3-day) obstruction results in increases in renal macrophages and the fibrogenic cytokine transforming growth factor-beta (TGF-beta), but their involvement in longer-term obstruction and fibrosis has not been studied. In the present experiments, kidneys of rats after UUO of 1, 2, 3, 7, 14, 21, and 28 days' duration were used. Trichrome staining, measurement of interstitial volume, and immunohistochemical studies localizing collagens I, III, and IV; laminin; fibronectin; TGF-beta; and macrophages were carried out. We found increases in the interstitial space in both cortex and medulla that (a) were significant by day 7 after UUO and (b) were accompanied by increased deposition of collagen I and collagen III. Collagen IV, laminin, and fibronectin, normally associated with the basement membrane, were found both in a thickened basement membrane and in the interstitial space. Macrophages, not found in sham-operated kidneys, were found in the interstitial space after UUO. TGF-beta was found in sham cortical tubules, but not in medullary tubules. UUO was associated with little change in cortical TGF-beta, whereas at 14 days, TGF-beta was found in dilated medullary tubules. Immunohistochemical findings were confirmed with measurements of tissue TGF-beta. In summary, UUO is associated with interstitial fibrosis. The increase in extracellular matrix is due both to increases in the interstitial collagens I and III and the basement membrane-associated collagen IV, laminin, and fibronectin. Macrophages are increased after UUO, but do not seem to be associated with the fibrogenic cytokine TGF-beta. Medullary tubular synthesis of TGF-beta may be a contributing factor in the fibrosis associated with UUO.
Assuntos
Túbulos Renais/metabolismo , Rim/patologia , Fator de Crescimento Transformador beta/metabolismo , Obstrução Ureteral/metabolismo , Obstrução Ureteral/patologia , Animais , Doença Crônica , Proteínas da Matriz Extracelular/metabolismo , Imuno-Histoquímica , Ratos , Ratos Sprague-Dawley , Distribuição TecidualRESUMO
The migration and proliferation of vascular smooth muscle cells (SMC) into the neointima are important early events in the development of atherosclerosis and post-angioplasty restenosis. The stimulation of SMC migration by platelet derived growth factor (PDGF) involves the induction of protein kinase C activity. Using immunoblot techniques, we demonstrated that rat aortic SMC express a pattern of PKC isoforms which includes PKC-alpha, delta, epsilon, zeta and eta. Upon exposure to PDGF-BB, a fraction of PKC-delta was rapidly translocated from the cytosol to the post-nuclear particulate fraction at 15 seconds and reached an apparent maximum at 30 minutes. In contrast, PKC-alpha and zeta were not translocated by PDGF-BB, TGF-beta 1, which inhibits PDGF-induced DNA synthesis and chemotaxis, reduced the immunoreactive levels of PKC-delta and blocked the PDGF-induced translocation of PKC-delta to the particulate fraction. This suggests that the activation of PKC-delta by translocation to the particulate fraction may play an important role in the control of vascular smooth muscle cell migration by PDGF and TGF-beta 1.
Assuntos
Isoenzimas/metabolismo , Músculo Liso Vascular/enzimologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteína Quinase C/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Sequência de Aminoácidos , Animais , Anticorpos , Aorta Torácica , Becaplermina , Células Cultivadas , Immunoblotting , Isoenzimas/química , Isoenzimas/efeitos dos fármacos , Masculino , Dados de Sequência Molecular , Músculo Liso Vascular/citologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Proteína Quinase C/química , Proteína Quinase C/efeitos dos fármacos , Proteína Quinase C-delta , Proteínas Proto-Oncogênicas c-sis , Coelhos , Ratos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/enzimologiaRESUMO
Atherosclerosis and postangioplasty restenosis may result from abnormal wound healing. The present studies report that normal human smooth muscle cells are growth inhibited by TGF-beta1, a potent wound healing agent, and show little induction of collagen synthesis to TGF-beta1, yet cells grown from human vascular lesions are growth stimulated by TGF-beta1 and markedly increase collagen synthesis. Both cell types increase plasminogen activator inhibitor-1 production, switch actin phenotypes in response to TGF-beta1, and produce similar levels of TGF-beta activity. Membrane cross-linking of 125I-TGF-beta1 indicates that normal human smooth muscle cells express type I, II, and III receptors. The type II receptor is strikingly decreased in lesion cells, with little change in the type I or III receptors. RT-PCR confirmed that the type II TGF-beta1 receptor mRNA is reduced in lesion cells. Transfection of the type II receptor into lesion cells restores the growth inhibitory response to TGF-beta1, implying that signaling remains responsive. Because TGF-beta1 is overexpressed in fibroproliferative vascular lesions, receptor-variant cells would be allowed to grow in a slow, but uncontrolled fashion, while overproducing extracellular matrix components. This TGF-beta1 receptor dysfunction may be relevant for atherosclerosis, restenosis and related fibroproliferative diseases.
Assuntos
Arteriosclerose/metabolismo , Doença das Coronárias/metabolismo , Vasos Coronários/metabolismo , Expressão Gênica/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Proteoglicanas/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Actinas/biossíntese , Arteriosclerose/patologia , Sequência de Bases , Divisão Celular/efeitos dos fármacos , Doença das Coronárias/patologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Primers do DNA , Proteínas da Matriz Extracelular/biossíntese , Humanos , Dados de Sequência Molecular , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Inibidor 1 de Ativador de Plasminogênio/biossíntese , Reação em Cadeia da Polimerase , Proteínas Serina-Treonina Quinases , Proteoglicanas/biossíntese , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/biossíntese , Proteínas Recombinantes/biossíntese , Valores de Referência , Transfecção , Fator de Crescimento Transformador beta/biossíntese , Fator de Crescimento Transformador beta/metabolismo , beta-Galactosidase/biossínteseRESUMO
The neurotrophins, a family of related polypeptide growth factors including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-3 and NT-4/5 promote the survival and differentiation of distinctive sets of embryonic neurons. Here we define a new functional role for neurotrophins, as autocrine or local paracrine mediators of vascular smooth muscle cell migration. We have identified neurotrophins, and their cognate receptors, the trk tyrosine kinases, in human and rat vascular smooth muscle cells in vivo. In vitro, cultured human smooth muscle cells express BDNF; NT-3; and trk A, B, and C. Similarly, rat smooth muscle cells expressed all three trk receptors as well as all four neurotrophins. Moreover, NGF induces cultured human smooth muscle cell migration at subnanomolar concentrations. In the rat aortic balloon deendothelialization model of vascular injury, the expression of NGF, BNDF, and their receptors trk A and trk B increased dramatically in the area of injury within 3 days and persisted during the formation of the neointima. In human coronary atherosclerotic lesions, BDNF, NT-3, and NT-4/5, and the trk B and trk C receptors could be demonstrated in smooth muscle cells. These findings suggest that neurotrophins play an important role in regulating the response of vascular smooth muscle cells to injury.