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1.
Appl Physiol Nutr Metab ; 46(11): 1430-1434, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34324824

RESUMO

Despite widespread use, community-based physical activity prescription is controversial. Data limitations have resulted in a lack of clarity about what works, under what circumstances, and for whom, reflected in conservative policy recommendations. In this commentary we challenge a predominantly negative discourse, using contemporary research to highlight promising findings and "lessons learnt" for design, delivery, and evaluation. In doing so, we argue for the importance of a more nuanced approach to future commissioning and evaluation. Novelty: Amalgamating learning from multiple research teams to create recommendations for advancing physical activity prescription.


Assuntos
Projetos de Pesquisa Epidemiológica , Exercício Físico , Promoção da Saúde , Humanos , Reino Unido
2.
Soc Sci Med ; 232: 156-167, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31100696

RESUMO

The burden of noncommunicable diseases (NCD) on health systems worldwide is substantial. Physical inactivity and sedentary behaviour are major risk factors for NCD. Previous attempts to understand the value for money of preventative interventions targeting physically inactive individuals have proved to be challenging due to key methodological challenges associated with the conduct of economic evaluations in public health. A systematic review was carried out across six databases (Medline, SPORTSDiscus, EconLit, PsychINFO, NHS EED, HTA) along with supplementary searches. The review examines how economic evaluations published between 2009-March 2017 have addressed methodological challenges with the aim of bringing to light examples of good practice for future studies. Fifteen economic evaluations from four high-income countries were retrieved; there is a dearth of studies targeting sedentary behaviour as an independent risk factor from physical activity. Comparability of studies from the healthcare and societal perspectives were limited due to analysts' choice in cost categories, valuation technique and time horizon differing substantially. The scarcity of and inconsistencies across economic evaluations for these two behaviours have exposed a mismatch between calls for more preventative action to tackle NCD and the lack of information available on how resources may be optimally allocated in practice. Consequently, this paper offers a table of recommendations on how future studies can be improved.


Assuntos
Análise Custo-Benefício/normas , Exercício Físico/psicologia , Comportamento Sedentário , Análise Custo-Benefício/métodos , Análise Custo-Benefício/estatística & dados numéricos , Humanos
3.
Health Educ Res ; 34(1): 113-127, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30307496

RESUMO

Exercise referral schemes aim to increase physical activity amongst inactive individuals with or at risk of long-term health conditions. Yet many patients referred to these schemes (by health professionals) fail to take up the exercise opportunities on offer. Understanding factors influencing uptake to exercise referral schemes may help improve future attendance. Using the Socio-Ecological Model as a framework, this qualitative study aimed to explore factors influencing uptake to an exercise referral scheme based in the North West of England. Semi-structured interviews were conducted with referred patients (n = 38) about their reasons for referral, interactions with referring health professionals, events following referral and ideas to improve future uptake. Data were analysed thematically and mapped onto the constructs of the Socio-Ecological Model. Factors reported to influence uptake included intrapersonal (past PA experiences, motivation, competing priorities), interpersonal (scheme explanations, support) and organizational influences (scheme promotion, communication between service, cost). Whilst several intrapersonal-level factors influenced patient decisions to uptake the exercise referral scheme, modifiable interpersonal and organizational factors were identified as potential targets for intervention. Recommendations are made for improving awareness of exercise referral schemes and for enhancing communication between referring practitioners, patients and referral scheme staff.


Assuntos
Exercício Físico/psicologia , Cooperação do Paciente/psicologia , Encaminhamento e Consulta , Adulto , Idoso , Inglaterra , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa
4.
Obes Rev ; 20(3): 448-463, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30468299

RESUMO

Despite continued public health campaigns to promote physical activity, a majority of the population is inactive. In recent years, mindfulness-based approaches have been used in health and lifestyle interventions for physical activity promotion. We conducted a systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to investigate the evidence for the potential of mindfulness-based approaches for physical activity. We searched electronic databases for papers that met eligibility criteria and identified 40 studies for inclusion. Evidence from cross-sectional studies (n = 20) indicated a positive relationship between dispositional mindfulness and physical activity, particularly with psychological factors related to physical activity. Five studies found that the mindfulness-physical activity relationship was mediated by stress, psychological flexibility, negative affect and shame, satisfaction and state mindfulness. Evidence from mindfulness-based interventions (n = 20) suggested positive between-subjects effects on physical activity, but interventions varied in duration, session length, group size, delivery, content and follow-up. Mindfulness-based interventions were more likely to be successful if they were physical activity-specific and targeted psychological factors related to physical activity. The body of research shows a need for more methodologically rigorous studies to establish the effect of mindfulness on physical activity and to identify potential mechanisms involved in the mindfulness-physical activity relationship reliably.


Assuntos
Exercício Físico/psicologia , Promoção da Saúde/métodos , Atenção Plena , Obesidade/prevenção & controle , Obesidade/psicologia , Estudos Transversais , Humanos , Programas de Redução de Peso
5.
J Public Health (Oxf) ; 40(4): e586-e593, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29688551

RESUMO

Background: Translational research is required to ensure exercise referral schemes (ERSs) are evidence-based and reflect local needs. This article reports process data from the co-development phase of an ERS, providing an insight into (i) factors that must be considered when translating evidence to practice in an ERS setting, and (ii) challenges and facilitators of conducting participatory research involving multiple stakeholders. Methods: An ERS was iteratively co-developed by a multidisciplinary stakeholder group (commissioners, managers, practitioners, patients and academics) via five participatory meetings and an online survey. Audio data (e.g. group discussions) and visual data (e.g. whiteboard notes) were recorded and analysed using NVivo-10 electronic software. Results: Factors to consider when translating evidence to practice in an ERS setting included (i) current ERS culture; (ii) skills, safety and accountability; and (iii) resources and capacity. The co-development process was facilitated by needs-analysis, open questions, multidisciplinary debate and reflective practice. Challenges included contrasting views, irregular attendance and (mis)perceptions of evaluation. Conclusion: The multidisciplinary co-development process highlighted cultural and pragmatic issues related to exercise referral provision, resulting in an evidence-based intervention framework designed to be implemented within existing infrastructures. Further work is required to establish the feasibility and effectiveness of the co-developed intervention in practice.


Assuntos
Exercício Físico , Encaminhamento e Consulta/organização & administração , Pesquisa Participativa Baseada na Comunidade , Humanos , Avaliação das Necessidades , Desenvolvimento de Programas , Inquéritos e Questionários , Pesquisa Translacional Biomédica
6.
Oncogenesis ; 5: e182, 2016 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-26751936

RESUMO

The cancer-associated Sm-like (CaSm) oncogene is overexpressed in 87% of human pancreatic tumor samples and CaSm knockdown has demonstrated therapeutic efficacy in murine models of pancreatic cancer. Evidence indicates that CaSm modulates messenger RNA degradation; however, its target genes and the mechanisms by which CaSm promotes pancreatic cancer remain largely unknown. Here, we demonstrate that the CaSm overexpression alters several hallmarks of cancer-including transformation, proliferation, chemoresistance and metastasis. Doxycycline-induced CaSm expression enhanced proliferation and both anchorage-dependent and -independent growth of the human Panc-1 cells in vitro. CaSm induction decreased gemcitabine-induced cytotoxicity and altered the expression of apoptotic regulation genes, including Bad, E2F1 and Bcl-XL. CaSm-overexpressing Panc-1 cells were twofold more migratory and fourfold more invasive than the driver controls and demonstrated characteristics of epithelial-to-mesenchymal transition such as morphological changes and decreased E-cadherin expression. CaSm induction resulted in changes in RNA expression of metastasis-associated genes such as MMP1, SerpinB5, uPAR and Slug. Using a murine model of metastatic pancreatic cancer, injection of CaSm-induced Panc-1 cells resulted in a higher abundance of hepatic metastatic lesions. Overall, CaSm overexpression contributed to a more aggressive cancer phenotype in Panc-1 cells, further supporting the use of CaSm as a therapeutic target against pancreatic cancer.

7.
Cancer Gene Ther ; 20(4): 222-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23470564

RESUMO

To overcome gene therapy barriers such as low transfection efficiency and nonspecific delivery, liposomal nanoparticles targeted by a single-chain antibody fragment to the transferrin receptor (TfRscFv) delivering wild-type (wt) human p53 (SGT-53) were developed for tumor-specific targeting. We hypothesize that SGT-53 in combination with gemcitabine will demonstrate enhanced therapeutic benefit in an in vivo metastatic pancreatic cancer model. Intrasplenic injection of 1 × 10(6) Panc02 murine pancreatic cancer cells was used to generate in vivo hepatic metastatic tumors. Nanoparticle localization was assessed by tail vein injection of TfRscFv with fluorescently labeled oligonucleotides (6-carboxyfluorescein phosphoramidite (6FAM) ODN) imaged by Xenogen IVIS 200 scan. SGT-53 (equivalent to 30 µg of p53 intravenously) and gemcitabine (20 mg/kg intraperitoneally) alone and in combination were administered biweekly and compared with untreated mice. Survival was determined by blinded daily assessment of morbidity. Human wtp53 expression and transferrin levels in the tumors were assessed by western blot analysis. Tumor burden was quantified by liver weight. Xenogen imaging demonstrated tumor-specific uptake of TfRscFv-6FAM ODN. Exogenous human wtp53 protein was detected in the SGT-53-treated tumors compared with control. Compared with untreated mice with metastatic tumors demonstrating median survival of 20 days, SGT-53, gemcitabine and the combination demonstrated improved median survival of 29, 30 and 37 days, respectively. The combination treatment prolonged median survival when compared with single drug treatment and decreased tumor burden. The tumor targeting liposomal-based SGT-53 nanoparticle is capable of sensitizing pancreatic cancer to conventional chemotherapy in pancreatic cancer models. This approach has the potential to be translated into a new, more effective therapy for pancreatic cancer. Further optimization is ongoing, moving towards a Phase 1B/2 clinical trial.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Desoxicitidina/análogos & derivados , Genes p53 , Neoplasias Hepáticas/metabolismo , Neoplasias Pancreáticas/metabolismo , Receptores da Transferrina/metabolismo , Animais , Antimetabólitos Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Terapia Combinada , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Técnicas de Transferência de Genes , Terapia Genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Camundongos , Camundongos Endogâmicos C57BL , Nanomedicina , Nanopartículas , Transplante de Neoplasias , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Receptores da Transferrina/imunologia , Anticorpos de Cadeia Única/imunologia , Carga Tumoral/efeitos dos fármacos , Gencitabina
9.
Am J Physiol Endocrinol Metab ; 280(2): E372-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11158943

RESUMO

We tested the hypothesis that leptin, in addition to reducing body fat by restraining food intake, reduces body fat through a peripheral mechanism requiring uncoupling protein 1 (UCP1). Leptin was administered to wild-type (WT) mice and mice with a targeted disruption of the UCP1 gene (UCP1 deficient), while vehicle-injected control animals of each genotype were pair-fed to each leptin-treated group. Leptin reduced the size of white adipose tissue (WAT) depots in WT mice but not in UCP1-deficient animals. This was accompanied by a threefold increase in the amount of UCP1 protein and mRNA in the brown adipose tissue (BAT) of WT mice. Leptin also increased UCP2 mRNA in WAT of both WT and UCP1-deficient mice but increased UCP2 and UCP3 mRNA only in BAT from UCP1-deficient mice. These results indicate that leptin reduces WAT through a peripheral mechanism requiring the presence of UCP1, with little or no involvement of UCP2 or UCP3.


Assuntos
Tecido Adiposo Marrom/fisiologia , Tecido Adiposo/anatomia & histologia , Tecido Adiposo/efeitos dos fármacos , Proteínas de Transporte/fisiologia , Leptina/farmacologia , Proteínas de Membrana/fisiologia , Proteínas de Membrana Transportadoras , Proteínas Mitocondriais , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Epididimo , Canais Iônicos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Proteínas/genética , RNA Mensageiro/metabolismo , Proteína Desacopladora 1 , Proteína Desacopladora 2 , Proteína Desacopladora 3
10.
J Biol Chem ; 275(42): 33059-67, 2000 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-10938091

RESUMO

The three known subtypes of beta-adrenoreceptors (beta(1)-AR, beta(2)-AR, and beta(3)-AR) are differentially expressed in brown and white adipose tissue and mediate peripheral responses to central modulation of sympathetic outflow by leptin. To assess the relative roles of the beta-AR subtypes in mediating leptin's effects on adipocyte gene expression, mice with a targeted disruption of the beta(3)-adrenoreceptor gene (beta(3)-AR KO) were treated with vehicle or the beta(1)/beta(2)-AR selective antagonist, propranolol (20 microgram/g body weight/day) prior to intracerebroventricular (ICV) injections of leptin (0.1 microgram/g body weight/day). Leptin produced a 3-fold increase in UCP1 mRNA in brown adipose tissue of wild type (FVB/NJ) and beta(3)-AR KO mice. The response was unaltered by propranolol in wild type mice, but was completely blocked by this antagonist in beta(3)-AR KO mice. In contrast, ICV leptin had no effect on leptin mRNA in either epididymal or retroperitoneal white adipose tissue (WAT) from beta(3)-AR KOs. Moreover, propranolol did not block the ability of exogenous leptin to reduce leptin mRNA in either WAT depot site of wild type mice. These results demonstrate that the beta(3)-AR is required for leptin-mediated regulation of ob mRNA expression in WAT, but is interchangeable with the beta(1)/beta(2)-ARs in mediating leptin's effect on UCP1 mRNA expression in brown adipose tissue.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo/metabolismo , Proteínas de Transporte/genética , Ventrículos Cerebrais/fisiologia , Regulação da Expressão Gênica/fisiologia , Leptina/genética , Leptina/farmacologia , Proteínas de Membrana/genética , Propranolol/farmacologia , Receptores Adrenérgicos beta 3/fisiologia , Transcrição Gênica , Antagonistas Adrenérgicos beta/farmacologia , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Ventrículos Cerebrais/efeitos dos fármacos , Imidazóis/farmacologia , Injeções Intraventriculares , Canais Iônicos , Leptina/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Proteínas Mitocondriais , Propanolaminas/farmacologia , RNA Mensageiro/genética , Receptores Adrenérgicos beta 3/deficiência , Receptores Adrenérgicos beta 3/genética , Receptores para Leptina , Proteína Desacopladora 1
11.
Am J Physiol Endocrinol Metab ; 279(2): E356-65, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10913036

RESUMO

Obesity-resistant (A/J) and obesity-prone (C57BL/6J) mice were weaned onto low-fat (LF) or high-fat (HF) diets and studied after 2, 10, and 16 wk. Despite consuming the same amount of food, A/J mice on the HF diet deposited less carcass lipid and gained less weight than C57BL/6J mice over the course of the study. Leptin mRNA was increased in white adipose tissue (WAT) in both strains on the HF diet but to significantly higher levels in A/J compared with C57BL/6J mice. Uncoupling protein 1 (UCP1) and UCP2 mRNA were induced by the HF diet in brown adipose tissue (BAT) and WAT of A/J mice, respectively, but not in C57BL/6J mice. UCP1 mRNA was also significantly higher in retroperitoneal WAT of A/J compared with C57BL/6J mice. The ability of A/J mice to resist diet-induced obesity is associated with a strain-specific increase in leptin, UCP1, and UCP2 expression in adipose tissue. The findings indicate that the HF diet does not compromise leptin-dependent regulation of adipocyte gene expression in A/J mice and suggest that maintenance of leptin responsiveness confers resistance to diet-induced obesity.


Assuntos
Gorduras na Dieta , Leptina/biossíntese , Proteínas de Membrana Transportadoras , Proteínas Mitocondriais , Obesidade/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Peso Corporal/fisiologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Ingestão de Alimentos/fisiologia , Ingestão de Energia/fisiologia , Expressão Gênica , Crescimento/fisiologia , Canais Iônicos , Leptina/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos A , Camundongos Endogâmicos C57BL , Obesidade/genética , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/metabolismo , Especificidade da Espécie , Proteína Desacopladora 1 , Proteína Desacopladora 2 , Proteína Desacopladora 3
12.
Endocrinology ; 140(10): 4772-8, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10499537

RESUMO

Exogenous leptin enhances energy utilization in ob/ob mice by binding its hypothalamic receptor and selectively increasing peripheral fat oxidation. Leptin also increases uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT), but the neurotransmitter that mediates this effect has not been established. The present experiments sought to determine whether leptin regulates UCP1 expression in BAT and its own expression in white adipose tissue (WAT) through the long or short forms of leptin receptor and modulation of norepinephrine release. Mice lacking dopamine beta-hydroxylase (Dbh-/-), the enzyme responsible for synthesizing norepinephrine and epinephrine from dopamine, were treated with leptin (20 microg/g body weight/day) for 3 days before they were euthanized. UCP1 messenger RNA (mRNA) and protein expression were 5-fold higher in BAT from control (Dbh+/-) compared with Dbh-/- mice. Leptin produced a 4-fold increase in UCP1 mRNA levels in Dbh+/- mice but had no effect on UCP1 expression in Dbh-/-. The beta3-adrenergic agonist, CL-316,243 increased UCP1 expression and established that BAT from both groups of mice was capable of responding to beta-adrenergic stimulation. Similarly, exogenous leptin reduced leptin mRNA in WAT from Dbh+/- but not Dbh-/- mice. In separate experiments, leptin produced comparable reductions in food intake in both Dbh+/- and Dbh-/- mice, illustrating that norepinephrine is not required for leptin's effect on food intake. Lastly, db/db mice lacking the long form of the leptin receptor failed to increase UCP1 mRNA in response to exogenous leptin but increased UCP1 mRNA in response to CL-316,243. These studies establish that norepinephrine is required for leptin to regulate its own expression in WAT and UCP1 expression in BAT and indicate that these effects are likely mediated through the centrally expressed long form of the leptin receptor.


Assuntos
Tecido Adiposo Marrom/fisiologia , Tecido Adiposo/fisiologia , Proteínas de Transporte/metabolismo , Expressão Gênica/fisiologia , Proteínas de Membrana/metabolismo , Norepinefrina/fisiologia , Proteínas/fisiologia , Animais , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Dopamina beta-Hidroxilase/genética , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Canais Iônicos , Leptina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout/genética , Camundongos Knockout/metabolismo , Proteínas Mitocondriais , Proteínas/genética , Proteínas/farmacologia , RNA Mensageiro/metabolismo , Proteína Desacopladora 1
13.
Endocrinology ; 140(1): 292-300, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9886838

RESUMO

Deposition of excess body fat occurs when energy intake chronically exceeds energy expenditure. In ob/ob mice, the absence of leptin affects both components of the energy balance equation, and the mice become morbidly obese after weaning. Treatment of ob/ob mice with exogenous leptin reduces body weight by decreasing food intake and stimulating energy utilization, but even when saline- and leptin-injected ob/ob mice are pair-fed, mice receiving leptin lose significantly more weight. Therefore, the purpose of the present study was to test the hypotheses that uncoupling protein-1 (UCP1) expression is reduced in adipose tissue from ob/ob mice and is restored by treatment with exogenous leptin. Lean and ob/ob mice (5-6 weeks old) were housed at 23 C and treated with leptin (20 microg/g BW x day) for 3 days before they were killed. Compared with levels in lean littermates, UCP1 messenger RNA (mRNA) and protein levels were lower in brown adipose tissue (BAT) and retroperitoneal white adipose tissue (WAT) from ob/ob mice. Treatment of ob/ob mice with leptin reduced body weight and produced a 4- to 5-fold increase in UCP1 mRNA levels in both interscapular BAT and retroperitoneal WAT. The increases in UCP1 mRNA were accompanied by comparable increases in UCP1 protein in mitochondrial preparations from each tissue. Given that the sole known function of UCP1 is to uncouple oxidative phosphorylation, the present results are consistent with the conclusion that leptin stimulates energy utilization in ob/ob mice by increasing thermogenic activity and capacity (UCP1). In addition, the present results suggest that decreased UCP1 expression in BAT and WAT of ob/ob mice is in part responsible for their increased metabolic efficiency and propensity to become obese.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo/metabolismo , Proteínas de Transporte/biossíntese , Proteínas de Membrana/biossíntese , Proteínas de Membrana Transportadoras , Proteínas Mitocondriais , Biossíntese de Proteínas , Proteínas/farmacologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Western Blotting , Peso Corporal/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Epididimo , Canais Iônicos , Leptina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Obesidade/metabolismo , Peritônio , RNA Mensageiro/metabolismo , Proteína Desacopladora 1 , Proteína Desacopladora 2
15.
Int J Obes Relat Metab Disord ; 21(10): 865-73, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9347404

RESUMO

OBJECTIVE: To investigate the role of hypercorticism in the development of compromised beta-adrenergic signalling in adipocytes of mature C57BL/6J-ob/ob mice. DESIGN AND EXPERIMENTAL UNITS: Mature male ob/ob mice and their lean littermates were treated with vehicle or the specific glucocorticoid receptor (GR) antagonist, RU-486 (30 mg/kg bw/d) for 21 d. MEASUREMENTS: Blood glucose, serum insulin, adipocyte Glut-4 expression, adipocyte Gs alpha expression, adenylylcyclase activation by beta-adrenergic receptor (beta-AR) agonists in adipocyte membranes and mRNA levels for beta 1-, beta 2- and beta 3-adrenergic receptor subtypes in adipocytes. RESULTS: RU-486 reduced blood glucose levels in ob/ob mice to levels that were not different from lean mice. RU-486 also reduced serum insulin by approximately 50% in ob/ob mice, but failed to restore depressed Gs alpha or GLUT-4 expression in adipocytes of ob/ob mice. RU-486 produced a two-fold increase in beta 3-AR mRNA in ob/ob mice and a small but significant improvement in isoprenaline-mediated adenylylcyclase activation. CONCLUSIONS: The present results indicate that glucocorticoid antagonism ameliorates diabetic symptoms of the mature ob/ob mouse, but does not lessen their obesity or fully reverse deficient expression and function of components of the adipocyte beta-adrenergic signalling cascade.


Assuntos
Adenilil Ciclases/metabolismo , Tecido Adiposo/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Antagonistas de Hormônios/farmacologia , Mifepristona/farmacologia , Proteínas Musculares , Receptores Adrenérgicos beta/efeitos dos fármacos , Receptores de Glucocorticoides/antagonistas & inibidores , Adenilil Ciclases/efeitos dos fármacos , Tecido Adiposo/citologia , Animais , Glicemia/metabolismo , Northern Blotting , Western Blotting , Colforsina/farmacologia , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Etanolaminas/farmacologia , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Transportador de Glucose Tipo 4 , Insulina/sangue , Isoproterenol/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Transporte de Monossacarídeos/metabolismo , Fenótipo , Transdução de Sinais/efeitos dos fármacos
16.
Endocrinology ; 138(7): 2697-704, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9202206

RESUMO

The role of hypercorticism in the development of compromised beta-adrenergic signaling in adipose tissue was assessed in ob/ob mice adrenalectomized at 4 weeks of age and studied 1 and 3 weeks thereafter. Adrenalectomy prevented the rapid increase in body weight and fat deposition between 4 and 5 weeks of age in ob/ob mice and produced a phenotype indistinguishable from that of lean mice. However, adrenalectomized ob/ob mice became intermediate between lean and ob/ob mice by 7 weeks of age. Adipocyte beta3-adrenergic receptor (AR) messenger RNA levels were similar between lean and adrenalectomized ob/ob mice at both time points and were 4- to 8-fold higher than messenger RNA levels in ob/ob mice. As judged by maximal activation of adenylyl cyclase by a beta3-AR-selective agonist, adrenalectomy also restored functional activity of the beta3-AR to levels above or equivalent to those seen in lean mice at both time points. The present results suggest that development of hypercorticism at or before weaning in ob/ob mice represses expression of the beta3-AR and prevents the normal postweaning development of this signaling system in the adipocyte.


Assuntos
Adipócitos/metabolismo , Glândulas Suprarrenais/fisiologia , Receptores Adrenérgicos beta/genética , Transdução de Sinais , Desmame , Adrenalectomia , Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Sítios de Ligação , Ligação Competitiva , AMP Cíclico/farmacologia , Dioxóis/farmacologia , Epinefrina/farmacologia , Imidazóis/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , RNA Mensageiro/metabolismo , Receptores Adrenérgicos beta/metabolismo , Receptores Adrenérgicos beta 3 , Ribonucleases/metabolismo , Estereoisomerismo
17.
Endocrinology ; 137(9): 4054-7, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8756584

RESUMO

Various model systems have been used to study the expression of the recently cloned ob gene, leptin. Here we report that freshly isolated rat white adipocytes incubated with insulin release leptin in a rapid and concentration-dependent manner (EC50 of 0.221 +/- .075 nM). Insulin-stimulated leptin release could be detected as early as 30 min and a maximal 2-3 fold effect was produced by 10 nM insulin. The effect of insulin was completely blocked by simultaneous activation of cAMP-dependent protein kinase. Using the activation of lipolysis as an index of cAMP-dependent protein kinase activity, we show that inhibition of leptin release by norepinephrine or the selective beta 3-adrenergic receptor agonist, CL316,243, occurred in parallel to activation of cAMP-dependent protein kinase. In addition, beta 1- and beta 2-adrenergic receptor antagonists did not impair the ability of norepinephrine or CL316,243 to inhibit leptin release from the adipocytes. These findings suggest that the beta 3-adrenergic receptor plays a central role in regulating the release of leptin from the adipocyte.


Assuntos
Adipócitos/metabolismo , Insulina/farmacologia , Proteínas/metabolismo , Receptores Adrenérgicos beta/fisiologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Separação Celular , Proteínas Quinases Dependentes de AMP Cíclico/farmacologia , Ativação Enzimática , Antagonistas da Insulina/farmacologia , Leptina , Masculino , Obesidade/genética , Ratos , Ratos Sprague-Dawley
18.
Cancer Pract ; 3(4): 247-53, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7620490

RESUMO

Although nausea and vomiting are among the most disruptive chemotherapy side effects, little is known about patients' expectations before therapy and their experience after chemotherapy. A stratified sample of 329 subjects on nine chemotherapy regimens were asked to list their expected symptoms and level of distress. The patients listed a total of 524 responses and 28 different symptoms. This paper focuses on the symptoms of nausea and vomiting. A statistically significant relationship (P = 0.015) was found between the patients' expectations of symptom experience and their expectations of symptom distress. No significant relationship was found between the expectation of the symptom and the actual symptom experience. These findings support the need for educational interventions that provide hopeful but realistic expectations of the unknown events for patients with cancer.


Assuntos
Antineoplásicos/efeitos adversos , Atitude Frente a Saúde , Náusea/induzido quimicamente , Educação de Pacientes como Assunto , Vômito Precoce/induzido quimicamente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/prevenção & controle , Diagnóstico de Enfermagem , Inquéritos e Questionários , Vômito Precoce/prevenção & controle
19.
Neurosci Lett ; 129(1): 6-10, 1991 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-1922971

RESUMO

Continuous tight junctions between vascular endothelial cells, the principal anatomical basis for the blood-brain barrier, have been investigated functionally and morphologically but their molecular components have not been defined. This communication reports that the protein ZO-1, a specific constituent of epithelial tight junctions, is found in human and rat brain vasculature. ZO-1-positive immunocytochemical staining forms a tightly banded pattern outlining individual endothelial cells in blood vessels of the human cerebral cortex. Rat brain exhibits a similar staining of blood vessels as well as ZO-1-positive staining around individual epithelial cells of the choroid plexus. The antiserum used for immunocytochemistry recognizes a protein of about 200 kDa in rat brain microvessels by Western blot. These findings indicate that ZO-1 is located at the interendothelial junctions of brain vasculature, implicating its importance as a component of the blood-brain barrier.


Assuntos
Barreira Hematoencefálica , Endotélio Vascular/química , Junções Intercelulares/química , Proteínas de Membrana/análise , Fosfoproteínas/análise , Animais , Vasos Sanguíneos/química , Córtex Cerebral/irrigação sanguínea , Humanos , Imuno-Histoquímica , Proteínas de Membrana/imunologia , Fosfoproteínas/imunologia , Ratos , Proteína da Zônula de Oclusão-1
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