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1.
Mol Psychiatry ; 22(12): 1701-1713, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27646262

RESUMO

Stressful life events produce a state of vulnerability to depression in some individuals. The mechanisms that contribute to vulnerability to depression remain poorly understood. A rat model of intense stress (social defeat (SD), first hit) produced vulnerability to depression in 40% of animals. Only vulnerable animals developed a depression-like phenotype after a second stressful hit (chronic mild stress). We found that this vulnerability to depression resulted from a persistent state of oxidative stress, which was reversed by treatment with antioxidants. This persistent state of oxidative stress was due to low brain-derived neurotrophic factor (BDNF) levels, which characterized the vulnerable animals. We found that BDNF constitutively controlled the nuclear translocation of the master redox-sensitive transcription factor Nrf2, which activates antioxidant defenses. Low BDNF levels in vulnerable animals prevented Nrf2 translocation and consequently prevented the activation of detoxifying/antioxidant enzymes, ultimately resulting in the generation of sustained oxidative stress. Activating Nrf2 translocation restored redox homeostasis and reversed vulnerability to depression. This mechanism was confirmed in Nrf2-null mice. The mice displayed high levels of oxidative stress and were inherently vulnerable to depression, but this phenotype was reversed by treatment with antioxidants. Our data reveal a novel role for BDNF in controlling redox homeostasis and provide a mechanistic explanation for post-stress vulnerability to depression while suggesting ways to reverse it. Because numerous enzymatic reactions produce reactive oxygen species that must then be cleared, the finding that BDNF controls endogenous redox homeostasis opens new avenues for investigation.


Assuntos
Transtorno Depressivo/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/fisiologia , Transporte Ativo do Núcleo Celular/fisiologia , Animais , Antioxidantes/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/patologia , Modelos Animais de Doenças , Suscetibilidade a Doenças , Dominação-Subordinação , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo/efeitos dos fármacos , Proteoma , Distribuição Aleatória , Ratos Sprague-Dawley
3.
Appl Psychophysiol Biofeedback ; 41(1): 61-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26346569

RESUMO

Health care that addresses the emotional regulation capacity of patients with schizophrenia confronted with daily stress may contribute to a less anxious life. A psycho-physiological training [cardiac coherence training (CCT)] focusing on emotion regulation is known to decrease anxiety for healthy individuals. We performed a pilot cross sectional survey to explore the benefits of CCT for clinically stable patients with schizophrenia. Ten patients were enrolled in the program consisting of twelve weekly 1-h session programs monitored over a 2-month period. Standardised questionnaires were used before and after the intervention to assess anxiety, well-being outcomes, and how patients deal with stress and stressors. Results showed that this quite-well accepted intervention improved (or tended to improve) well-being outcomes, state-anxiety, and emotional stressors evaluation. The successful transformations were higher for patients with the highest clinical and emotional suffering. Thus, this pilot study revealed that CCT may help patients with schizophrenia to deal with anxiety in daily life.


Assuntos
Ansiedade/terapia , Biorretroalimentação Psicológica/métodos , Emoções/fisiologia , Frequência Cardíaca/fisiologia , Interocepção/fisiologia , Qualidade de Vida/psicologia , Esquizofrenia/terapia , Estresse Psicológico/terapia , Adulto , Ansiedade/epidemiologia , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Esquizofrenia/epidemiologia , Estresse Psicológico/epidemiologia , Resultado do Tratamento
4.
Encephale ; 42(1): 99-104, 2016 Feb.
Artigo em Francês | MEDLINE | ID: mdl-26796563

RESUMO

INTRODUCTION: The concept of mindfulness is characterized by awareness and acceptance of experiences; flexible regulation of attention; an objective receptivity to experience and an orientation to the here-and-now. Interest in 'mindfulness' and 'mindfulness meditation' is recent and growing both at the levels of research and of clinical practice in the West as mindfulness is associated with health and well-being. It (mindfulness) is attained by the practice of certain types of meditation. One of the current key challenges is to evaluate and measure the level of mindfulness of a subject and its evolution. OBJECTIVES: The paper proposes a reflexion on the concept of mindfulness with a view to improving the operational evaluation of mindfulness level for clinical and non-clinical subjects. METHODS: First, the problems with the use of existing self-report questionnaires assessing mindfulness level are discussed. Second, an analysis of the cognitive processes that come into play in mindfulness acquisition (by meditation) can highlight the significance of certain cognitive tools in a more accurate evaluation of the level of mindfulness of individuals. CONCLUSION: Self-regulation of attention, and orientation to lived experience could be operational candidates for assessing the level of mindfulness. The pertinence of well-known paradigms evaluating self-regulation of attention and orientation to experience are discussed.


Assuntos
Conscientização , Atenção Plena , Atenção , Humanos , Meditação/psicologia , Autorrelato
5.
Encephale ; 40(6): 474-80, 2014 Dec.
Artigo em Francês | MEDLINE | ID: mdl-25194754

RESUMO

The first part of this paper describes the long history of the concept of Mindfulness. Contrary to the belief that Mindfulness only has Buddhist and Hindu origins, it is also rooted in Jewish, Islamic and Christian religions. Furthermore, western philosophers have described a mindful path to become more aware of thoughts, feelings, and bodily sensations. Mindfulness can be considered as a universal human ability embodied to foster clear thinking and open-heartedness. As such, this form of being requires no particular religious or cultural belief system. The current acceptance of what a mindful path is, refers to a psychological quality that involves bringing one's complete attention to present experience on a moment-to-moment basis, in a particular way: in the present moment, and nonjudgmentally. Although such a definition is well accepted in France, the French translation for Mindfulness is not easy to use: being conscious and being aware are translated with the same French word. The French language fails to clearly separate the dimensional attributes of a mindful subject from the ways for developing mindfulness through formal meditation practice. In line with this conception, stability and assessments of Mindfulness mainly were examined. How this disposition allows the development of concentration, attention and acceptance moment by moment in a nonjudgmental way is described in the second part. Particular attention is paid to its positive effects in several aspects of mental and physical health. In particular, positive effects on the ability to cope with stress are described from a physiological point of view. Third, this article intends to present neurobiological aspects currently proposed to explain the benefits of Mindfulness meditation. Modifications of cerebral networks and neurobiological functioning are described in relation to expertise in meditation practice. The hypothesis of the role of meditation on neuroplasticity is also discussed. Furthermore, the specific impact of Mindfulness meditation practice on these mechanisms will be considered in comparison with relaxation techniques. With the increasing growth of well-designed and well-controlled meditation research, however, future studies will be needed to compare between different meditation techniques. This will enable researchers to outline the effects of the technique-specific differences on behavior, cognitive function, underlying physiology and neurobiology and clinical effectiveness. Finally, the most recent data on the changes in functioning of a resting brain (Brain Default Mode) induced by a Mindfulness practice, demonstrate differences in the default-mode network that are consistent with decreased mind-wandering. That is a way to better understand possible neural mechanisms of meditation for health benefits of Mindfulness.


Assuntos
Encéfalo/fisiopatologia , Atenção Plena , Plasticidade Neuronal/fisiologia , Religião e Psicologia , Atenção/fisiologia , Conscientização/fisiologia , Comportamento/fisiologia , Cognição/fisiologia , Humanos , Meditação/psicologia , Rede Nervosa/fisiopatologia , Terapia de Relaxamento/métodos , Estresse Psicológico/fisiopatologia , Estresse Psicológico/terapia
6.
Heliyon ; 9(11): e21945, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38027965

RESUMO

Antibody kinetic curves obtained during a viral infection are often fitted using aggregated patient data, hiding the heterogeneity of individual humoral immune responses. Individual antibody responses can be modeled using the Wood equation and grouped according to their profile. Such modeling takes into account several important kinetic parameters, such as the day when antibody detection becomes positive [daypos], the day of the maximal response [daymax], the maximum antibody level [levelmax], and the day when antibody detection becomes negative [dayneg]. Potential associations between these profiles and studied factors can then be tested.

7.
Drug Alcohol Depend ; 41(3): 209-17, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8842633

RESUMO

Longitudinal studies can be hampered by poor follow-up rates, seriously reducing generalizability of the findings. Understanding the barriers, as well as approaches to overcome and adapt to these impediments, resulted in a 96.6% 18 month follow-up rate of 479 drug abusers enrolled in an NIDA funded demonstration project aimed at reducing HIV transmission among St. Louis' most vulnerable drug-using population. In this paper, we discuss the importance of phone and systems tracking, creative team work and persistence and procedures for tracking out-of-treatment drug-users by analyzing the efforts needed to reach the study subjects. We also compared the characteristics of hard-to-reach respondents with those who were less difficult. The results revealed that employment status was the only characteristic associated with being hard-to-reach. Gender, race, age, education and psychiatric status did not discriminate recruitment difficulty in this sample. The study findings suggest that although unemployment predicted recruitment difficulty, and that the locator information provided by the respondent can be very helpful, a comprehensive tracking strategy as well as persistence and creative team work are the most important determinants of the rate of success of a follow-up investigation.


Assuntos
Transtornos Relacionados ao Uso de Substâncias , Adulto , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade
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