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1.
J Interpers Violence ; 37(23-24): NP21476-NP21501, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34865554

RESUMO

Purpose: While the importance of domestic violence has been examined in relation to parenting behaviors and child development, less is known about the link between justifying attitudes toward wife beating and parenting, especially in low- and middle-income countries (LMIC). This study employs an actor-partner interdependence mediation model to examine how parents' justifying attitudes toward violence against women relate to their own (actor effects) and their partners' (partner effects) level of parental involvement, which then influence their preschool children's early development. Method: Using data from mothers, fathers, and children in 16,010 families residing in LMIC that participated in UNICEF's Multiple Indicator Cluster Survey Waves 4-5-6 and a dyadic mediation modeling approach, we have examined the associations between maternal and paternal justification of violence against women, parental involvement, and children's early development. Results: Results revealed that mothers' greater justification of violence against themselves were associated with decreased level of maternal (actor effect) and paternal (partner effect) involvement, while fathers' greater justification of violence against their wives was related to decreased paternal involvement (actor effect). Furthermore, mediation tests indicated that paternal justification of violence was negatively and indirectly associated with early childhood development through paternal involvement. Moreover, maternal justification of violence was negatively and indirectly associated with early childhood development through both maternal and paternal involvement. Conclusion: Mothers' and fathers' justifying attitudes toward domestic violence emerge as a possible risk factor for child development that can be addressed by preventive interventions.


Assuntos
Violência Doméstica , Pai , Masculino , Pré-Escolar , Feminino , Humanos , Poder Familiar , Mães , Pais , Atitude , Fatores de Risco , Nações Unidas
2.
Br J Educ Psychol ; 91(4): 1434-1455, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34042178

RESUMO

BACKGROUND: Coding has been added to school curricula in several countries, being one of the necessary competencies of the 21st century. Although it has also been suggested to foster the development of several cognitive skills such as computational thinking and problem-solving, studies on the effects of coding are very limited, provide mixed results, and lack causal evidence. AIM: This study aims to evaluate the impact of a learn-to-code programme on three cognitive skills in children: computational thinking, fluid intelligence, and spatial orientation, using a randomized trial. SAMPLE: One hundred seventy-four (n = 81 girls) 4th-grade children participated in the study. METHODS: Children were randomly assigned to one of the three 10-week learning programmes: learn-to-code (treatment of interest), mathematics (another STEM-related comparison treatment), and reading (control). Children responded to paper-pencil computational thinking, and spatial orientation measurements, and face-to-face matrix reasoning task at pre- and post-tests. RESULTS: Results showed that children's computational thinking scores increased significantly only in the learn-to-code condition. Fluid intelligence significantly increased in all conditions, possibly due to a practice effect. The spatial orientation did not improve in any of the conditions. CONCLUSION: These findings suggested that learning to code can be selectively beneficial for the development of computational thinking skills while not effective for spatial reasoning and fluid intelligence.


Assuntos
Resolução de Problemas , Pensamento , Criança , Cognição , Feminino , Humanos , Matemática , Instituições Acadêmicas
3.
Res Dev Disabil ; 113: 103941, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33831663

RESUMO

Changing teacher willingness to teach inclusive classes is critical in achieving optimal outcomes for students with autism spectrum disorder (ASD). The present study investigated the mechanisms underlying the effects of a teacher training in special education strategies for students with ASD on mainstream school teachers' behavioral intentions toward inclusive education. Specifically, the role of attitudes and autism self-efficacy were explored as mediators in this process. The sample comprised 763 mainstream school teachers from eleven cities in Northeastern Turkey who participated in an intensive training that included special education strategies for students with ASD, evidence-based special education applications, and inclusive education practices. Statistical mediation analyses revealed that the training increased teachers' willingness to teach inclusive classes and intention to implement special education techniques in the regular education classroom through increasing their autism self-efficacy. However, though attitudes toward inclusive education was a significant predictor of both willingness to teach inclusive classes and intent to use special education techniques, the training did not improve attitudes. Based on these findings, additional strategies or components to change attitudes toward inclusive education were recommended to be integrated into the teacher training programs on special education strategies for inclusive education.


Assuntos
Transtorno do Espectro Autista , Capacitação de Professores , Educação Inclusiva , Humanos , Professores Escolares , Turquia
4.
Front Psychol ; 11: 2067, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922345

RESUMO

In many disciplines, mediating processes are usually investigated with randomized experiments and linear regression to determine if the treatment affects the outcome through a mediator. However, randomizing the treatment will not yield accurate causal direct and indirect estimates unless certain assumptions are satisfied since the mediator status is not randomized. This study describes methods to estimate causal direct and indirect effects and reports the results of a large Monte Carlo simulation study on the performance of the ordinary regression and modern causal mediation analysis methods, including a previously untested doubly robust sequential g-estimation method, when there are confounders of the mediator-to-outcome relation. Results show that failing to measure and incorporate potential post-treatment confounders in a mediation model leads to biased estimates, regardless of the analysis method used. Results emphasize the importance of measuring potential confounding variables and conducting sensitivity analysis.

5.
Educ Psychol Meas ; 78(3): 460-481, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30140102

RESUMO

When testing a statistical mediation model, it is assumed that factorial measurement invariance holds for the mediating construct across levels of the independent variable X. The consequences of failing to address the violations of measurement invariance in mediation models are largely unknown. The purpose of the present study was to systematically examine the impact of mediator noninvariance on the Type I error rates, statistical power, and relative bias in parameter estimates of the mediated effect in the single mediator model. The results of a large simulation study indicated that, in general, the mediated effect was robust to violations of invariance in loadings. In contrast, most conditions with violations of intercept invariance exhibited severely positively biased mediated effects, Type I error rates above acceptable levels, and statistical power larger than in the invariant conditions. The implications of these results are discussed and recommendations are offered.

6.
Exp Gerontol ; 111: 133-140, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30006298

RESUMO

The obesity epidemic is multi-generational and is particularly debilitating in the aging population, necessitating the use of pharmaceutical interventions. Recent evidence suggests that increasing the activity of the angiotensin converting enzyme-2 [ACE2]/angiotensin-(1-7)[Ang-(1-7)]/Mas receptor (MasR) axis in obese animal models leads to significant reductions in body weight. It was hypothesized that activation of ACE2 via diminazene aceturate (DIZE) will significantly reduce body weight of rats fed a high fat diet. Young and old (4 and 23 months, respectively) male Fisher 344 × Brown Norway rats were fed 60% high fat diet for one week, and subsequently given either 15 mg/kg/day DIZE s.c. or vehicle for three weeks. DIZE treatment resulted in a significant reduction of food intake and body weight in both young and old animals. However, that decrease was so dramatic in the older animals that they all nearly stopped eating. Interestingly, the TD-NMR assessments revealed that the weight-loss was primarily a result of decreased body fat percentage, with a relative preservation of lean mass. Tissue weights confirm the significant loss of white adipose tissue (WAT), with no change in muscle weights. Gene expression and serum ACE2 activity analyses implied that increased activation of the ACE2/Ang-(1-7)/MasR axis plays a role in reducing fat mass. Collectively, our results suggest that DIZE may be a useful tool in the study of obesity; however, caution is recommended when using this compound in older animals due to severe anorectic effects, although there is a mechanism by which muscle is preserved.


Assuntos
Adiposidade/efeitos dos fármacos , Angiotensina I/metabolismo , Diminazena/análogos & derivados , Obesidade/metabolismo , Fragmentos de Peptídeos/metabolismo , Peptidil Dipeptidase A/metabolismo , Fatores Etários , Angiotensina I/genética , Enzima de Conversão de Angiotensina 2 , Animais , Diminazena/farmacologia , Modelos Animais de Doenças , Expressão Gênica , Masculino , Fragmentos de Peptídeos/genética , Peptidil Dipeptidase A/sangue , Peptidil Dipeptidase A/genética , Ratos , Ratos Endogâmicos F344 , Sistema Renina-Angiotensina/efeitos dos fármacos
7.
Eval Rev ; 42(1): 111-143, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29852743

RESUMO

Compared to the randomized experiment (RE), the regression discontinuity design (RDD) has three main limitations: (1) In expectation, its results are unbiased only at the treatment cutoff and not for the entire study population; (2) it is less efficient than the RE and so requires more cases for the same statistical power; and (3) it requires correctly specifying the functional form that relates the assignment and outcome variables. One way to overcome these limitations might be to add a no-treatment functional form to the basic RDD and including it in the outcome analysis as a comparison function rather than as a covariate to increase power. Doing this creates a comparative regression discontinuity design (CRD). It has three untreated regression lines. Two are in the untreated segment of the RDD-the usual RDD one and the added untreated comparison function-while the third is in the treated RDD segment. Also observed is the treated regression line in the treated segment. Recent studies comparing RE, RDD, and CRD causal estimates have found that CRD reduces imprecision compared to RDD and also produces valid causal estimates at the treatment cutoff and also along all the rest of the assignment variable. The present study seeks to replicate these results, but with considerably smaller sample sizes. The power difference between RDD and CRD is replicated, but not the bias results either at the treatment cutoff or away from it. We conclude that CRD without large samples can be dangerous.


Assuntos
Teste de Esforço , Análise de Regressão , Reprodutibilidade dos Testes , Projetos de Pesquisa , Interpretação Estatística de Dados , Teste de Esforço/estatística & dados numéricos , Humanos , Tamanho da Amostra
8.
Behav Brain Res ; 340: 14-22, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28419850

RESUMO

BACKGROUND & AIM: Overpressure blast-wave induced brain injury (OBI) and its long-term neurological outcome pose significant concerns for military personnel. Our aim is to investigate the mechanism of injury due to OBI. METHODS: Rats were divided into 3 groups: (1) Control, (2) OBI (exposed 30psi peak pressure, 2-2.5ms), (3) Repeated OBI (r-OBI) (three exposures over one-week period). Lung and brain (cortex and cerebellum) tissues were collected at 24h post injury. RESULTS: The neurological examination score was worse in OBI and r-OBI (4.2±0.6 and 3.7±0.5, respectively) versus controls (0.7±0.2). A significant positive correlation between lung and brain edema was found. Malondialdehyde (index for lipid peroxidation), significantly increased in OBI and r-OBI groups in cortex (p<0.05) and cerebellum (p<0.01-0.001). The glutathione (endogenous antioxidant) level decreased in cortex (p<0.01) and cerebellum (p<0.05) of r-OBI group when compared with the controls. Myeloperoxidase activity indicating neutrophil infiltration, was significantly (p<0.01-0.05) elevated in r-OBI. Additionally, tissue thromboplastin activity, a coagulation marker, was elevated, indicating a tendency to bleed. NGF and NF-κB proteins along with Iba-1 and GFAP immunoreactivity significantly augmented in the frontal cortex demonstrating microglial activation. Serum biomarkers of injury, NSE, TNF-alpha and leptin, were also elevated. CONCLUSION: OBI triggers both inflammation and oxidative injury in the brain. This data in conjunction with our previous observations suggests that OBI triggers a cascade of events beginning with impaired cerebral vascular function leading to ischemia and chronic neurological consequences.


Assuntos
Traumatismos por Explosões/metabolismo , Cerebelo/lesões , Lobo Frontal/lesões , Inflamação/metabolismo , Estresse Oxidativo/fisiologia , Animais , Traumatismos por Explosões/complicações , Traumatismos por Explosões/patologia , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Edema Encefálico/etiologia , Edema Encefálico/metabolismo , Edema Encefálico/patologia , Cerebelo/metabolismo , Cerebelo/patologia , Modelos Animais de Doenças , Lobo Frontal/metabolismo , Lobo Frontal/patologia , Gliose/etiologia , Gliose/metabolismo , Gliose/patologia , Glutationa/metabolismo , Inflamação/etiologia , Inflamação/patologia , Leptina/sangue , Pulmão/metabolismo , Pulmão/patologia , Masculino , Malondialdeído/metabolismo , Microglia/metabolismo , Microglia/patologia , Peroxidase/metabolismo , Ratos Sprague-Dawley , Tromboplastina/metabolismo
9.
Psychol Methods ; 23(1): 150-168, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28301197

RESUMO

In the "sharp" regression discontinuity design (RD), all units scoring on one side of a designated score on an assignment variable receive treatment, whereas those scoring on the other side become controls. Thus the continuous assignment variable and binary treatment indicator are measured on the same scale. Because each must be in the impact model, the resulting multi-collinearity reduces the efficiency of the RD design. However, untreated comparison data can be added along the assignment variable, and a comparative regression discontinuity design (CRD) is then created. When the untreated data come from a non-equivalent comparison group, we call this CRD-CG. Assuming linear functional forms, we show that power in CRD-CG is (a) greater than in basic RD; (b) less sensitive to the location of the cutoff and the distribution of the assignment variable; and that (c) fewer treated units are needed in the basic RD component within the CRD-CG so that savings can result from having fewer treated cases. The theory we develop is used to make numerical predictions about the efficiency of basic RD and CRD-CG relative to each other and to a randomized control trial. Data from the National Head Start Impact study are used to test these predictions. The obtained estimates are closer to the predicted parameters for CRD-CG than for basic RD and are generally quite close to the parameter predictions, supporting the emerging argument that CRD should be the design of choice in many applications for which basic RD is now used. (PsycINFO Database Record


Assuntos
Interpretação Estatística de Dados , Psicologia/métodos , Projetos de Pesquisa , Humanos
10.
Am J Physiol Endocrinol Metab ; 314(3): E224-E231, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29089334

RESUMO

We evaluated the contribution of brown adipose tissue (BAT) sympathetic innervation on central leptin-mediated weight loss. In a short- and long-term study, F344BN rats were submitted to either a denervation of interscapular BAT (Denervated) or a sham operation (Sham). Animals from each group received the Ob (Leptin) or green fluorescent protein (GFP; Control) gene through a single injection of recombinant adeno-associated virus delivered centrally. Changes in body weight were recorded for 14 or 35 days, after which adipose tissues and skeletal muscles were weighed. In both studies, hypothalamic phosphorylated STAT3 (P-STAT3) was significantly higher in Sham-Leptin and Denervated-Leptin groups compared with their respective Control groups ( P < 0.01), indicating that leptin signaling was enhanced at the end point. We measured uncoupling protein 1 (UCP1), a marker of BAT thermogenic activity, and found a significant induction in Leptin in Sham animals ( P < 0.001) but not in Denervated animals, demonstrating that BAT UCP1 protein was only induced in Sham rats. Both Sham-Leptin and Denervated-Leptin rats lost ~15% of their initial body weight ( P < 0.001) by day 14 and reached a maximum of 18% body weight loss that stabilized over week 3 of treatment, indicating that sympathetic outflow to BAT is not required for leptin-mediated weight loss. In summary, interscapular BAT (iBAT) denervation did not prevent body weight loss following central leptin gene delivery. The present data show that sympathetic innervation of iBAT is not essential for leptin-induced body weight loss.


Assuntos
Tecido Adiposo Marrom/inervação , Técnicas de Transferência de Genes , Leptina/administração & dosagem , Leptina/genética , Sistema Nervoso Simpático/fisiologia , Redução de Peso/genética , Tecido Adiposo Marrom/metabolismo , Animais , Peso Corporal/genética , Denervação , Dependovirus/genética , Regulação da Expressão Gênica , Infusões Intraventriculares , Masculino , Ratos , Ratos Endogâmicos F344 , Ratos Transgênicos , Termogênese/efeitos dos fármacos , Termogênese/genética , Proteína Desacopladora 1/metabolismo , Redução de Peso/fisiologia
11.
J Gerontol A Biol Sci Med Sci ; 73(4): 450-458, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29040389

RESUMO

Nutritional ketosis is induced by high fat/low carbohydrate dietary regimens, which produce high levels of circulating ketone bodies, shifting metabolism away from glucose utilization. While ketogenic diets (KD) were initially introduced to suppress seizures, they are garnering attention for their potential to treat a myriad of neurodegenerative and metabolic disorders that are associated with advanced age. The feasibility and physiological impact of implementing a long-term KD in old animals, however, has not been systematically examined. In this study, young and aged rats consumed a calorically- and nutritionally-matched KD or control diet for 12 weeks. All KD-fed rats maintained higher levels of BHB and lower levels of glucose relative to controls. However, it took the aged rats longer to reach asymptotic levels of BHB compared to young animals. Moreover, KD-fed rats had significantly less visceral white and brown adipose tissue than controls without a loss of lean mass. Interestingly, the KD led to significant alterations in protein levels of hippocampal transporters for monocarboxylates, glucose, and vesicular glutamate and gamma-aminobutyric acid. Most notably, the age-related decline in vesicular glutamate transporter expression was reversed by the KD. These data demonstrate the feasibility and potential benefits of KDs for treating age-associated neural dysfunction.


Assuntos
Adiposidade , Dieta Cetogênica , Hipocampo , Proteínas de Membrana Transportadoras , Animais , Ratos , Adiposidade/fisiologia , Fatores Etários , Glicemia/metabolismo , Western Blotting , Química Encefálica/fisiologia , Hipocampo/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Modelos Animais , Distribuição Aleatória , Ratos Endogâmicos F344
12.
Methods Mol Biol ; 1598: 313-325, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28508370

RESUMO

Endocrine disorders and autonomic dysfunction are common paradigms following traumatic brain injury (TBI). Alterations in the hypothalamus-pituitary-adrenal (HPA) axis following TBI may result in impaired vasopressor response, energy imbalance, fatigue, depression, or neurological disorders. Autonomic dysfunction is a common disorder following TBI. The sympathetic activity markers on HPA axis can be measured by Western blot protein analysis. Tyrosine hydroxylase, dopamine beta hydroxylase are the key enzymes for the synthesis of norepinephrine; and neuropeptide Y (NPY) is the peptide that is co-stored and co-released with norepinephrine. Thus, the present chapter reviews the experimental protocols for Western blot protein analysis for the measurement of biomarkers that indicate sympathetic activity in brain regions (hypothalamus, pituitary, cerebral cortex, and cerebellum) following TBI.


Assuntos
Lesões Encefálicas/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Proteoma , Proteômica , Animais , Biomarcadores , Disautonomias Primárias/metabolismo , Proteômica/métodos , Ratos
13.
Appl Physiol Nutr Metab ; 42(1): 59-67, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28006433

RESUMO

Hypothalamic inflammation and increased oxidative stress are believed to be mechanisms that contribute to obesity. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol), a free radical scavenger, has been shown to reduce inflammation and oxidative stress. We hypothesized that brain infusion of tempol would reduce oxidative stress, and thus would reduce food intake and body weight and improve body composition in rats with age-related obesity and known elevated oxidative stress. Furthermore, we predicted an associated increase in markers of leptin signalling, including the silent mating type information regulator 2 homolog 1 (SIRT1)/5'AMP-activated protein kinase (AMPK) pathway and the signal transducer and activator of transcription 3 (STAT3) pathway. For this purpose, osmotic minipumps were placed in the intracerebroventricular region of young (3 months) and aged (23 months) male Fischer 344 x Brown Norway rats for the continuous infusion of tempol or vehicle for 2 weeks. Tempol significantly decreased (p < 0.01) nicotinamide adenine dinucleotide phosphate oxidase activity in the hypothalamus but failed to reduce food intake or weight gain and did not alter body composition. SIRT1 activity and Acetyl p53 were decreased and phosphorylation of AMPK was increased with age, but they were unchanged with tempol. Basal phosphorylation of STAT3 was unchanged with age or tempol. These results indicate that tempol decreases oxidative stress but fails to alter feeding behaviour, body weight, or body composition. Moreover, tempol does not modulate the SIRT1/AMPK/p53 pathway and does not change leptin signalling. Thus, a reduction in hypothalamic oxidative stress is not sufficient to reverse age-related obesity.


Assuntos
Envelhecimento , Disfunção Cognitiva/prevenção & controle , Óxidos N-Cíclicos/administração & dosagem , Sequestradores de Radicais Livres/administração & dosagem , Hipotálamo/efeitos dos fármacos , Nootrópicos/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Disfunção Cognitiva/etiologia , Cruzamentos Genéticos , Óxidos N-Cíclicos/efeitos adversos , Óxidos N-Cíclicos/uso terapêutico , Ingestão de Energia/efeitos dos fármacos , Sequestradores de Radicais Livres/efeitos adversos , Sequestradores de Radicais Livres/uso terapêutico , Hipotálamo/metabolismo , Bombas de Infusão Implantáveis , Infusões Intraventriculares , Masculino , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Nootrópicos/efeitos adversos , Nootrópicos/uso terapêutico , Obesidade/tratamento farmacológico , Obesidade/fisiopatologia , Ratos Endogâmicos BN , Ratos Endogâmicos F344 , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/metabolismo , Marcadores de Spin
14.
J Exerc Nutrition Biochem ; 20(1): 41-8, 2016 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-27298812

RESUMO

PURPOSE: To determine whether resveratrol improves the adverse effects age on vascular function in mesenteric arteries (MAs), and diminishes the hyperactivity in adrenal gland with age. METHODS: Male F344 x Brown Norway rats were assigned to 6-month control (YC), 6-month resveratrol (YR), 24-month control (OC) and 24-month resveratrol (OR). Resveratrol (15 mg/kg) was provided to resveratrol groups in drinking water for 14 days. RESULTS: Concentration response curves to phenylephrine (PE, 10(-9)-10(-5)M), acetylcholine (Ach, 10(-9)-10(-5)M) and resveratrol (10(-8)-10(-4)M) were evaluated in pressurized isolated MAs. The Ach concentration-response curve was right shifted with maximal response diminished in OC compared with YC rats. These effects were reversed by resveratrol treatment. The resveratrol-mediated relaxant responses were unchanged with age or resveratrol suggesting an endothelium-independent mechanism. Resveratrol tended to increase endothelial nitric oxide synthase; caused no effect on copper-zinc superoxide dismutase; and normalized the age-related elevatation in DßH and NPY levels in adrenal medulla, two indicators of sympathetic activity. CONCLUSION: These data indicate that resveratrol reverses age-related dysfunction in endothelium-dependent vasodilation in MAs and partially reverses hyperactivity of adrenomedullary function with age. This treatment may have a therapeuticpotential in the treatment of cardiovascular diseases or hypertension in the elderly.

15.
Clin Exp Pharmacol Physiol ; 43(9): 802-7, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27232670

RESUMO

The authors have previously demonstrated that a low and intermittent peripheral dose of rapamycin (1 mg/kg three times/week) to rats inhibited mTORC1 signalling, but avoided the hyperlipidemia and diabetes-like syndrome associated with higher doses of rapamycin. The dosing regimen reduced food intake, body weight, adiposity, serum leptin and triglycerides. mTORC1 signalling was inhibited in both liver and hypothalamus, suggesting some of the actions, in particular the decrease in food intake, may be the results of a central mechanism. To test this hypothesis, rapamycin (30 µg/day for 4 weeks) was infused into 23-25-month-old F344xBN rats by intracerebroventricular (icv) mini pumps. Our results demonstrated that central infusion did not alter food intake or body weight, although there was a tendency for a decrease in body weight towards the end of the study. mTORC1 signalling, evidenced by decreased phosphorylation of S6 protein at end of 4 weeks, was not activated in liver, hypothalamus or hindbrain. Fat and lean mass, sum of white adipose tissues, brown adipose tissue, serum glucose, insulin and leptin levels remained unchanged. Thus, these data suggest that the anorexic and body weight responses evident with peripheral rapamycin are not the result of direct central action. The tendency for decreased body weight towards the end of study, suggests that there is either a slow transport of centrally administered rapamycin into the periphery, or that there is delayed action of rapamycin at sites in the brain.


Assuntos
Anorexia/tratamento farmacológico , Anorexia/fisiopatologia , Sirolimo/farmacologia , Animais , Anorexia/metabolismo , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Energia/efeitos dos fármacos , Ratos , Sirolimo/uso terapêutico , Resultado do Tratamento
16.
Eur J Pharmacol ; 779: 177-85, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-27012992

RESUMO

Leptin administration results in leptin resistance presenting a significant barrier to therapeutic use of leptin. Consequently, we examined two hypotheses. The first examined the relationship between leptin dose and development of physiological and biochemical signs of leptin resistance. We hypothesized lower doses of leptin would produce proportional reductions in body weight without the adverse leptin-induced leptin resistance. The second compared pulsed central leptin infusion to continuous leptin infusion. We hypothesized that pulsed infusion at specific times of the day would evoke favorable body weight reductions while tempering the development of leptin-induced leptin resistance. The first experiment examined leptin responsiveness, including food intake, body weight and hypothalamic STAT3 phosphorylation to increasing doses of viral gene delivery of leptin. Varying the dose proved inconsequential with respect to long-term therapy and demonstrated proportional development of leptin resistance. The second experiment examined leptin responsiveness to pulsed central leptin infusion, comparing pulsed versus constant infusion of 3µg/day leptin or a 2h morning versus a 2h evening pulsed leptin infusion. Pulsed delivery of the supramaximal dose of 3µg/day was not different than constant delivery. Morning pulsed infusion of the submaximal dose of 0.25µg reduces food intake only over subsequent immediate meal period and was associated with body weight reductions, but results in cellular leptin resistance. Evening pulsed infusion did not decrease food intake but reduces body weight and maintains full leptin signaling. The positive benefit for pulsed delivery remains speculative, yet potentially may provide an alternative mode of leptin therapy.


Assuntos
Resistência a Medicamentos/efeitos dos fármacos , Leptina/administração & dosagem , Leptina/farmacologia , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Animais , Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Esquema de Medicação , Ingestão de Alimentos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Leptina/metabolismo , Masculino , Ratos , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Proteína Desacopladora 1/metabolismo
17.
Bone ; 85: 99-106, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26855373

RESUMO

Dietary-induced obesity (DIO) resulting from high-fat (HF) or high-sugar diets produces a host of deleterious metabolic consequences including adverse bone development. We compared the effects of feeding standard rodent chow (Control), a 30% moderately HF (starch-based/sugar-free) diet, or a combined 30%/40% HF/high-fructose (HF/F) diet for 12weeks on cancellous/cortical bone development in male Sprague-Dawley rats aged 8weeks. Both HF feeding regimens reduced the lean/fat mass ratio, elevated circulating leptin, and reduced serum total antioxidant capacity (tAOC) when compared with Controls. Distal femur cancellous bone mineral density (BMD) was 23-34% lower in both HF groups (p<0.001) and was characterized by lower cancellous bone volume (BV/TV, p<0.01), lower trabecular number (Tb.N, p<0.001), and increased trabecular separation versus Controls (p<0.001). Cancellous BMD, BV/TV, and Tb.N were negatively associated with leptin and positively associated with tAOC at the distal femur. Similar cancellous bone deficits were observed at the proximal tibia, along with increased bone marrow adipocyte density (p<0.05), which was negatively associated with BV/TV and Tb.N. HF/F animals also exhibited lower osteoblast surface and reduced circulating osteocalcin (p<0.05). Cortical thickness (p<0.01) and tissue mineral density (p<0.05) were higher in both HF-fed groups versus Controls, while whole bone biomechanical characteristics were not different among groups. These results demonstrate that "westernized" HF diets worsen cancellous, but not cortical, bone parameters in skeletally-immature male rats and that fructose incorporation into HF diets does not exacerbate bone loss. In addition, they suggest that leptin and/or oxidative stress may influence DIO-induced alterations in adolescent bone development.


Assuntos
Osso e Ossos/patologia , Dieta Hiperlipídica , Comportamento Alimentar , Frutose/farmacologia , Adipócitos/efeitos dos fármacos , Adipócitos/patologia , Adipogenia/efeitos dos fármacos , Animais , Biomarcadores/sangue , Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Medula Óssea/patologia , Medula Óssea/fisiopatologia , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiopatologia , Osso Esponjoso/efeitos dos fármacos , Osso Esponjoso/patologia , Osso Esponjoso/fisiopatologia , Masculino , Ratos Sprague-Dawley , Microtomografia por Raio-X
18.
J Pers Soc Psychol ; 109(6): 1068-89, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26389797

RESUMO

The issue of Americans' levels of narcissism is subject to lively debate. The focus of the present research is on the perception of national character (PNC) of Americans as a group. In Study 1, American adults (N = 100) rated Americans as significantly more narcissistic than they perceived themselves and acquaintances. In Study 2, this finding was replicated with American college students (N = 322). PNC ratings of personality traits and externalizing behaviors revealed that Americans were perceived as disagreeable and antisocial as well. In Study 3, we examined the broader characteristics associated with PNC ratings (N = 183). Americans rated the typical American as average on a variety of characteristics (e.g., wealth, education, health, likability) and PNC ratings of narcissism were largely unrelated to these ratings. In Study 4 (N = 1,202) Americans rated PNCs for different prespecified groups of Americans; as expected, PNC ratings of narcissism differed by gender, age, and occupational status such that American males, younger Americans, and Americans working in high-visibility and status occupations were seen as more narcissistic. In Study 5 (N = 733), citizens of 4 other world regions (Basque Country, China, England, Turkey) rated members of their own region as more narcissistic than they perceived themselves, but the effect sizes were smaller than those found in the case of Americans' perceptions of Americans. Additionally, members of these other regions rated Americans as more narcissistic than members of their own region. Finally, in Study 6, participants from around the world (N = 377) rated Americans as more narcissistic, extraverted, and antagonistic than members of their own countries. We discuss the role that America's position as a global economic and military power, paired with a culture that creates and reifies celebrity figures, may play in leading to perceptions of Americans as considerably narcissistic.


Assuntos
Comparação Transcultural , Narcisismo , Personalidade , Percepção Social , Adulto , Caráter , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos da Personalidade/psicologia , Estados Unidos/etnologia , Adulto Jovem
19.
J Cereb Blood Flow Metab ; 35(12): 1950-6, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26104291

RESUMO

Overpressure blast-wave induced brain injury (OBI) leads to progressive pathophysiologic changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema, and cerebral ischemia. The aim of this study was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague-Dawley rats were divided into three groups: Control (Naive), single OBI (30 psi peak pressure, 1 to 2 msec duration), and repeated (days 1, 4, and 7) OBI (r-OBI). Rats were killed 24 hours after injury and the basilar artery was isolated, cannulated, and pressurized (90 cm H2O). Vascular responses to potassium chloride (KCl) (30 to 100 mmol/L), endothelin-1 (10(-12) to 10(-7) mol/L), acetylcholine (ACh) (10(-10) to 10(-4) mol/L) and diethylamine-NONO-ate (DEA-NONO-ate) (10(-10) to 10(-4) mol/L) were evaluated. The OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and r-OBI groups. However, impaired DEA-NONO-ate-induced vasodilation and increased wall thickness to lumen ratio were observed only in the r-OBI group. The endothelin-1 type A (ET(A)) receptor and endothelial nitric oxide synthase (eNOS) immunoreactivity were significantly enhanced by OBI. These findings indicate that both single and r-OBI impairs cerebral vascular endothelium-dependent dilation, potentially a consequence of endothelial dysfunction and/or vascular remodelling in basilar arteries after OBI.


Assuntos
Artéria Basilar/patologia , Traumatismos por Explosões/patologia , Lesões Encefálicas/patologia , Animais , Capilares/patologia , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/metabolismo , Pressão , Ratos , Ratos Sprague-Dawley , Receptor de Endotelina A/efeitos dos fármacos , Receptor de Endotelina A/metabolismo , Vasoconstritores/farmacologia , Vasodilatadores/farmacologia
20.
Appetite ; 81: 180-92, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24949566

RESUMO

Inhibitory control and sensitivity to reward are relevant to the food choices individuals make frequently. An imbalance of these systems can lead to deficits in decision-making that are relevant to food ingestion. This study evaluated the relationship between dietary behaviors - binge eating and consumption of sweetened beverages and snacks - and behavioral control processes among 198 adolescents, ages 14 to 17. Neurocognitive control processes were assessed with the Iowa Gambling Task (IGT), a generic Go/No-Go task, and a food-specific Go/No-Go task. The food-specific version directly ties the task to food cues that trigger responses, addressing an integral link between cue-habit processes. Diet was assessed with self-administered food frequency and binge eating questionnaires. Latent variable models revealed marked gender differences. Inhibitory problems on the food-specific and generic Go/No-Go tasks were significantly correlated with binge eating only in females, whereas inhibitory problems measured with these tasks were the strongest correlates of sweet snack consumption in males. Higher BMI percentile and sedentary behavior also predicted binge eating in females and sweet snack consumption in males. Inhibitory problems on the generic Go/No-Go, poorer affective decision-making on the IGT, and sedentary behavior were associated with sweetened beverage consumption in males, but not females. The food-specific Go/No-Go was not predictive in models evaluating sweetened beverage consumption, providing some initial discriminant validity for the task, which consisted of sweet/fatty snacks as no-go signals and no sugar-sweetened beverage signals. This work extends research findings, revealing gender differences in inhibitory function relevant to behavioral control. Further, the findings contribute to research implicating the relevance of cues in habitual behaviors and their relationship to snack food consumption in an understudied population of diverse adolescents not receiving treatment for eating disorders.


Assuntos
Bulimia/psicologia , Comportamento Alimentar/psicologia , Inibição Psicológica , Edulcorantes/administração & dosagem , Adolescente , Bebidas , Índice de Massa Corporal , Comportamento de Escolha , Estudos Transversais , Sinais (Psicologia) , Ingestão de Energia , Feminino , Preferências Alimentares , Humanos , Masculino , Atividade Motora , Lanches , Inquéritos e Questionários
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