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2.
BMC Public Health ; 19(1): 1553, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752787

RESUMO

BACKGROUND: Sugar-sweetened beverage consumption is contributing to the obesity epidemic. On 28 March 2017, Catalonia enacted a law levying an excise tax on sugar-sweetened beverages for public health reasons. The purpose of this study is to assess the impact of the tax on the consumption of sugar-sweetened beverages in Catalonia (Spain). METHODS: Before-and-after study to assess changes in the prevalence of consumption of sugar-sweetened beverages among 1929 persons aged 12 to 40 years residing in low-income neighbourhoods of Barcelona (intervention) and Madrid (control). Beverage consumption frequency was ascertained via a validated questionnaire administered during the month prior to the tax's introduction (May 2017) and again at 1 year after it had come into force. The effect of the tax was obtained using Poisson regression models with robust variance weighted using propensity scores. RESULTS: While the prevalence of regular consumers of taxed beverages fell by 39% in Barcelona as compared to Madrid, the prevalence of consumers of untaxed beverages remained stable. The main reason cited by more than two-thirds of those surveyed for reducing their consumption of sugar-sweetened beverages was the increase in price, followed by a heightened awareness of their health effects. CONCLUSIONS: The introduction of the Catalonian excise tax on sugar-sweetened beverages was followed by a reduction in the prevalence of regular consumers of taxed beverages.


Assuntos
Áreas de Pobreza , Bebidas Adoçadas com Açúcar/economia , Bebidas Adoçadas com Açúcar/estatística & dados numéricos , Impostos , Adolescente , Adulto , Criança , Inquéritos sobre Dietas , Feminino , Humanos , Masculino , Espanha , Adulto Jovem
3.
Int J Mol Sci ; 20(7)2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30959735

RESUMO

Melatonin administration has been associated with different benefits in animals and patients suffering from liver diseases. However, there is no published data about circulating melatonin levels in patients with hepatocellular carcinoma (HCC) who underwent liver transplantation (LT). Thus, the objective of this observational and retrospective study was to determine whether patients with HCC with lower serum melatonin levels prior to LT have a higher risk of one-year mortality after LT. We measured serum levels of melatonin, malondialdehyde (to assess lipid peroxidation), and total antioxidant capacity (to assess antioxidant state) before LT. One-year surviving LT patients (n = 129) showed higher serum levels of melatonin (p = 0.001) and total antioxidant capacity (p = 0.001) and lower serum levels of malondialheyde (p = 0.01) than non-surviving LT patients (n = 16). Logistic regression analysis showed that high serum melatonin levels prior to LT were associated with lower one-year LT mortality (odds ratio = 0.525; 95% confidence interval (CI) = 0.331⁻0.834; p = 0.006). We found an association between serum levels of melatonin with serum levels of malondialheyde (rho = -0.22; p = 0.01) and total antioxidant capacity (rho = 0.21; p = 0.01). Thus, the novel findings of our study were the association between high serum melatonin levels prior to LT and survival at first year after LT and the association between serum levels of melatonin with malondialheyde and total antioxidant capacity.


Assuntos
Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Transplante de Fígado/mortalidade , Melatonina/sangue , Adulto , Idoso , Feminino , Humanos , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Curva ROC
4.
Rev Invest Clin ; 70(4): 177-183, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30067727

RESUMO

Background: Central nervous system (CNS) tumors are a group of neoplasms that originate from various cells in the CNS. The increasing incidence and prevalence of this type of tumor in developing countries are striking; however, there are few current studies in Latin America including Mexico estimating the impact of these pathological entities on the general population. Objective: The objective of the study was to study the characteristics of primary CNS tumors over a period of 52 years. Methods: A review of records from patients with a histopathological diagnosis of CNS neoplasm over a period of 52 years was conducted at a tertiary-care academic medical center. Patients were grouped by sex, age, and the tumor's anatomical location. Results: A sample of 9615 patients with tumor lesions was obtained; 51% were female, 49% were male, and their mean age was 42 years. The tumors with the highest prevalence were neuroepithelial tumors (38.6%), followed by meningeal tumors (22.8%). Neuroepithelial tumors accounted for 64% in the group of patients under 40 years of age and 56% among those above 40 years of age. The most frequently involved location was supratentorial, in 78.9% of cases. Conclusions: Although retrospective in nature and based on a small sample, this study reports the epidemiology and characteristics of primary brain tumors in the Mexican population.


Assuntos
Neoplasias Encefálicas/epidemiologia , Neoplasias do Sistema Nervoso Central/epidemiologia , Neoplasias Meníngeas/epidemiologia , Neoplasias Neuroepiteliomatosas/epidemiologia , Adulto , Distribuição por Idade , Neoplasias Encefálicas/patologia , Neoplasias do Sistema Nervoso Central/patologia , Feminino , Humanos , Incidência , Masculino , Neoplasias Meníngeas/patologia , México/epidemiologia , Pessoa de Meia-Idade , Neoplasias Neuroepiteliomatosas/patologia , Prevalência , Estudos Retrospectivos , Distribuição por Sexo , Adulto Jovem
6.
Nature ; 468(7324): 696-700, 2010 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-21068725

RESUMO

Parkinson's disease is a pervasive, ageing-related neurodegenerative disease the cardinal motor symptoms of which reflect the loss of a small group of neurons, the dopaminergic neurons in the substantia nigra pars compacta (SNc). Mitochondrial oxidant stress is widely viewed as being responsible for this loss, but why these particular neurons should be stressed is a mystery. Here we show, using transgenic mice that expressed a redox-sensitive variant of green fluorescent protein targeted to the mitochondrial matrix, that the engagement of plasma membrane L-type calcium channels during normal autonomous pacemaking created an oxidant stress that was specific to vulnerable SNc dopaminergic neurons. The oxidant stress engaged defences that induced transient, mild mitochondrial depolarization or uncoupling. The mild uncoupling was not affected by deletion of cyclophilin D, which is a component of the permeability transition pore, but was attenuated by genipin and purine nucleotides, which are antagonists of cloned uncoupling proteins. Knocking out DJ-1 (also known as PARK7 in humans and Park7 in mice), which is a gene associated with an early-onset form of Parkinson's disease, downregulated the expression of two uncoupling proteins (UCP4 (SLC25A27) and UCP5 (SLC25A14)), compromised calcium-induced uncoupling and increased oxidation of matrix proteins specifically in SNc dopaminergic neurons. Because drugs approved for human use can antagonize calcium entry through L-type channels, these results point to a novel neuroprotective strategy for both idiopathic and familial forms of Parkinson's disease.


Assuntos
Relógios Biológicos/fisiologia , Dopamina/metabolismo , Neurônios/metabolismo , Proteínas Oncogênicas/metabolismo , Estresse Oxidativo , Animais , Encéfalo/citologia , Encéfalo/metabolismo , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/farmacologia , Sinalização do Cálcio , Peptidil-Prolil Isomerase F , Ciclofilinas/metabolismo , Di-Hidropiridinas/farmacologia , Deleção de Genes , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/metabolismo , Glicosídeos Iridoides/farmacologia , Iridoides , Masculino , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/metabolismo , Neurônios/citologia , Proteínas Oncogênicas/deficiência , Proteínas Oncogênicas/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Doença de Parkinson/prevenção & controle , Peroxirredoxinas , Proteína Desglicase DJ-1 , Purinas/farmacologia , Superóxidos/metabolismo , Proteína Desacopladora 1
8.
Int J Mol Sci ; 17(9)2016 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-27618033

RESUMO

Cytokeratin (CK)-18 is the major intermediate filament protein in the liver and during hepatocyte apoptosis is cleaved by the action of caspases; the resulting fragments are released into the blood as caspase-cleaved cytokeratin (CCCK)-18. Higher circulating levels of CCCK-18 have been found in patients with hepatocellular carcinoma (HCC) than in healthy controls and than in cirrhotic patients. However, it is unknown whether serum CCCK-18 levels before liver transplantation (LT) in patients with HCC could be used as a prognostic biomarker of one-year survival, and this was the objective of our study with 135 patients. At one year after LT, non-survivors showed higher serum CCCK-18 levels than survivors (p = 0.001). On binary logistic regression analysis, serum CCCK-18 levels >384 U/L were associated with death at one year (odds ratio = 19.801; 95% confidence interval = 5.301-73.972; p < 0.001) after controlling for deceased donor age. The area under the receiver operating characteristic (ROC) curve of serum CCCK-18 levels to predict death at one year was 77% (95% CI = 69%-84%; p < 0.001). The new finding of our study was that serum levels of CCCK-18 before LT in patients with HCC could be used as prognostic biomarker of survival.


Assuntos
Carcinoma Hepatocelular/sangue , Queratina-18/química , Neoplasias Hepáticas/sangue , Fragmentos de Peptídeos/sangue , Biomarcadores/sangue , Carcinoma Hepatocelular/terapia , Caspases/metabolismo , Feminino , Humanos , Queratina-18/sangue , Neoplasias Hepáticas/terapia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Análise de Sobrevida
10.
J Vasc Surg ; 61(4): 1041-9.e1, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24472415

RESUMO

OBJECTIVE: Circulating anti-ß2-glycoprotein I (ABGPI) antibodies are associated with peripheral arterial disease (PAD) and induce the expression of leukocyte adhesion molecules and proinflammatory cytokines by endothelial cells. Our aim is to study a transcriptional activation pathway of the innate immune system through the cellular signalling cascade triggered by receptors Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) of endothelial cells after the exposure of these cells to seropositive ABGPI human serum obtained from PAD patients. METHODS: We obtained serum samples from PAD patients and controls without PAD. ABGPI serum titer was detected using indirect immunofluorescence. Our sample was stratified into three groups: group I (PAD and ABGPI titer ≥1:100; n = 15), group II (PAD and ABGPI titer <1:100; n = 15), and control participants (no PAD; n = 15). All serum samples were incubated with human aortic endothelial cell (HAEC) culture. Genomic expression of TLR2 and TLR4 receptors and their shared intracellular signalling molecules, myeloid differentiation primary response gene 88 (MyD88), and interleukin (IL)-1 receptor-associated kinase (1IRAK1), were measured after the exposure of HAECs to each serum. RESULTS: HAEC genomic expression of TLR4 was higher after the exposure to group I serum than after the exposure to group II serum (log10×10-relative quantification [RQ]: 1.80 ± 0.42 vs 1.37 ± 0.39; P = .01) or control serum (log10×10-RQ: 1.80 ± 0.42 vs 1.09 ± 0.26; P < .01). TLR4 expression was higher in group II than in the control group (log10×10-RQ: 1.37 ± 0.39 vs 1.09 ± 0.26; P = .04). TLR4 expression correlated with MyD88 (r = 0.54; P < .01) and IRAK1 (r = 0.55; P < .01) expression. We recorded a positive correlation between MyD88 and IRAK1 genomic expression (r = 0.58; P < .01). CONCLUSIONS: Our results suggest that serum from PAD patients with elevated ABGPI antibodies induces a genomic overexpression of TLR4 and its cellular signalling molecules in endothelial cells.


Assuntos
Autoanticorpos/sangue , Células Endoteliais/metabolismo , Doença Arterial Periférica/sangue , Receptor 4 Toll-Like/metabolismo , beta 2-Glicoproteína I/imunologia , Idoso , Estudos de Casos e Controles , Células Cultivadas , Células Endoteliais/imunologia , Feminino , Humanos , Imunidade Inata , Quinases Associadas a Receptores de Interleucina-1/genética , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Masculino , Pessoa de Meia-Idade , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Doença Arterial Periférica/imunologia , RNA Mensageiro/metabolismo , Transdução de Sinais , Fatores de Tempo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Transcrição Gênica , Regulação para Cima
11.
J Exp Biol ; 218(Pt 2): 316-25, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25524977

RESUMO

In the present study, we assessed the responses of the vasotocinergic and isotocinergic systems to chronic stress induced by cortisol administration in the gilthead sea bream (Sparus aurata). Pituitary and plasma arginine vasotocin (AVT) and isotocin (IT) levels, as well as hypothalamic pro-vasotocin (pro-VT) and pro-isotocin (pro-IT) mRNA expression levels, were analysed. In addition, the mRNA levels of three receptors, AVTR type V1a2, AVTR type V2 and ITR, were analysed in several target organs associated with the following physiological processes: (i) integration and control (hypothalamus), (ii) metabolism and its control (liver and hypothalamus), (iii) osmoregulation (gills) and (iv) stress response (head kidney). Specimens were injected intraperitoneally with slow-release implants (5 µL g(-1) body mass) containing coconut oil alone (control group) or with cortisol (50 µg g(-1) body mass; cortisol group). Both AVT and IT synthesis and release were correlated with plasma cortisol values, suggesting a potential interaction between both hormonal systems and cortisol administration. Our results suggest that the activation of hepatic metabolism as well as the hypothalamic control of metabolic processes provide the energy necessary to overcome stress, which could be partly mediated by AVTRs and ITR. Upregulation of branchial AVT and IT receptor expression following cortisol treatment suggests an involvement of the vasotocinergic and isotocinergic systems in the regulation of ion channels/transporters during stressful situations. Finally, changes in AVT and IT receptor mRNA expression in the head kidney suggest these nonapeptides participate in feedback mechanisms that regulate the synthesis/release of cortisol. Our results indicate a relationship between cortisol and both the vasotocinergic and isotocinergic systems during simulated chronic stress in S. aurata.


Assuntos
Receptores de Vasopressinas/metabolismo , Dourada/metabolismo , Estresse Fisiológico/fisiologia , Animais , Sequência de Bases , Brânquias/fisiologia , Rim Cefálico/metabolismo , Hidrocortisona/metabolismo , Hipotálamo/fisiologia , Fígado/metabolismo , Masculino , Osmorregulação/fisiologia , Ocitocina/análogos & derivados , Ocitocina/metabolismo , Hipófise/fisiologia , RNA Mensageiro/metabolismo , Receptores de Vasopressinas/genética , Dourada/genética , Vasotocina/metabolismo
12.
Front Physiol ; 15: 1410660, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38966230

RESUMO

Somatic growth in vertebrates is mainly controlled by the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis. The role of epigenetic mechanisms in regulating this axis in fish is far from being understood. This work aimed to optimize and evaluate the use of short-term culture of pituitary and liver explants from a farmed fish, the gilthead seabream Sparus aurata, for studying epigenetic mechanisms involved in GH/IGF-I axis regulation. Our results on viability, structure, proliferation, and functionality of explants support their use in short-term assays. Pituitary explants showed no variation in gh expression after exposure to the DNA methylation inhibitor decitabine (5-Aza-2'-deoxycytidine; DAC), despite responding to DAC by changing dnmt3bb and tet1 expression, and TET activity, producing an increase in overall DNA hydroxymethylation. Conversely, in liver explants, DAC had no effects on dnmt s and tet s expression or activity, but modified the expression of genes from the GH-IGF-I axis. In particular, the expression of igfbp2a was increased and that of igfbp4, ghri and ghrii was decreased by DAC as well as by genistein, which is suggestive of impaired growth. While incubation of liver explants with S-adenosylmethionine (SAM) produced no clear effects, it is proposed that nutrients must ensure the methylation milieu within the liver in the fish to sustain proper growth, which need further in vivo verification. Pituitary and liver explants from S. aurata can be further used as described herein for the screening of inhibitors or activators of epigenetic regulators, as well as for assessing epigenetic mechanisms behind GH-IGF-I variation in farmed fish.

13.
Foods ; 12(18)2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37761223

RESUMO

Satsuma mandarins are good sources of vitamin C and can be used as raw materials to produce novel plant-based food ingredients including satsuma mandarin juice powders (SJP). Food powders produced via spray drying often show thermal degradation due to the drying conditions and high drying air temperatures. The aim of this study was to evaluate the effect of using different spray drying configurations, including concurrent (CC), mixed flow (MX), and combined (CC + MX), at two inlet air temperatures (160 and 180 °C) on the physicochemical properties of SJP. Remarkably, SJP produced using the CC spray drying configuration exhibited a higher vitamin C content (3.56-4.01 mg/g) and lower moisture levels (15.18-16.35 g/100 g) than powders produced via MX or CC + MX. The vitamin C content of MX and CC + MX powders ranged from 2.88 to 3.33 mg/g. Meanwhile, all SJP had water activity values below 0.19. Furthermore, MX powders displayed the largest mean particle sizes (D50) (8.69-8.83 µm), higher agglomeration, and a rapid dissolution. Despite these differences, all SJP variants exhibited consistent color, surface area, and pore volumes. Notably, powders dried at higher inlet air temperatures (180 °C) showed less vitamin C content and increased thermal damage when compared with powders dried at 160 °C inlet air temperature. This study demonstrated the feasibility of producing high-quality SJP with an extended shelf life. SJP can be used as a novel plant-based ingredient in different food applications.

14.
Chem Mater ; 35(9): 3522-3531, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37181669

RESUMO

Nanoparticles (NPs) of conjugated polymers in intimate contact with sheets of graphene oxide (GO) constitute a promising class of water-dispersible nanohybrid materials of increased interest for the design of sustainable and improved optoelectronic thin-film devices, revealing properties exclusively pre-established upon their liquid-phase synthesis. In this context, we report for the first time the preparation of a P3HTNPs-GO nanohybrid employing a miniemulsion synthesis approach, whereby GO sheets dispersed in the aqueous phase serve as a surfactant. We show that this process uniquely favors a quinoid-like conformation of the P3HT chains of the resulting NPs well located onto individual GO sheets. The accompanied change in the electronic behavior of these P3HTNPs, consistently confirmed by the photoluminescence and Raman response of the hybrid in the liquid and solid states, respectively, as well as by the properties of the surface potential of isolated individual P3HTNPs-GO nano-objects, facilitates unprecedented charge transfer interactions between the two constituents. While the electrochemical performance of nanohybrid films is featured by fast charge transfer processes, compared to those taking place in pure P3HTNPs films, the loss of electrochromic effects in P3HTNPs-GO films additionally indicates the unusual suppression of polaronic charge transport processes typically encountered in P3HT. Thus, the established interface interactions in the P3HTNPs-GO hybrid enable a direct and highly efficient charge extraction channel via GO sheets. These findings are of relevance for the sustainable design of novel high-performance optoelectronic device structures based on water-dispersible conjugated polymer nanoparticles.

15.
World J Clin Cases ; 11(8): 1753-1760, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36970008

RESUMO

BACKGROUND: Fas ligand (FasL) is one ligand that activates extrinsic apoptosis pathway. High expression in lymphocytes of FasL have been found in patients with acute rejection of liver transplantation (LT). No high blood concentrations of soluble FasL (sFasL) have been found in patients with acute LT rejection; however, the samples size of those studies was small. AIM: To determine whether patients with hepatocellular carcinoma (HCC) that dead during the first year of LT have higher blood sFasL concentrations previously to LT that those who that remain alive in a study of higher sample size. METHODS: Patients underwent LT due to HCC were included in this retrospective study. Serum sFasL levels prior to LT were measured and one-year LT mortality was registered. RESULTS: Non-surviving patients (n = 14) showed higher serum sFasL levels [477 (269-496) vs 85 (44-382) pg/mL; P < 0.001] than surviving patients (n = 113). Serum sFasL levels (pg/mL) were associated with mortality (OR = 1.006; 95%CI = 1.003-1.010; P = 0.001) independently of age of LT donor in the logistic regression analysis. CONCLUSION: We report for the first time that HCC patients who die within the first year of HT have higher blood sFasL concentrations prior to HT than those who remain alive.

16.
World J Hepatol ; 14(6): 1182-1189, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35978670

RESUMO

BACKGROUND: Oxidative damage of DNA and RNA has been associated with mortality of patients with different diseases. However, there is no published data on the potential use of DNA and RNA oxidative damage to predict the prognosis of patients with hepatocellular carcinoma (HCC) undergoing liver transplantation (LT). AIM: To determine whether patients with increased DNA and RNA oxidative damage prior to LT for HCC have a poor LT prognosis. METHODS: Patients with HCC who underwent LT were included in this observational and retrospective study. Serum levels of all three oxidized guanine species (OGS) were measured prior to LT since guanine is the nucleobase that forms DNA and RNA most prone to oxidation. LT mortality at 1 year was the end-point study. RESULTS: Surviving patients (n = 101) showed lower serum OGS levels (P = 0.01) and lower age of the liver donor (P = 0.03) than non-surviving patients (n = 13). An association between serum OGS levels prior to LT and 1-year LT (odds ratio = 2.079; 95% confidence interval = 1.356-3.189; P = 0.001) was found in the logistic regression analysis. CONCLUSION: The main new finding was that high serum OGS concentration prior to LT was associated with the mortality 1 year after LT in HCC patients.

17.
Artigo em Inglês | MEDLINE | ID: mdl-33801958

RESUMO

Parenting generally brings about high internal and external demands, which can be perceived as stressful when they exceed families' resources. When faced with such stressors, parents need to deploy several adaptive strategies to successfully overcome these challenges. One of such strategies is coping, an important cognitive and behavioural skill. In this study, we intended to examine the psychometric properties of Carver's (1997) Brief COPE (Coping Orientation to Problems Experienced), extending its cross-cultural validity among a Portuguese sample of community and at-risk parents. The sample comprised community (n = 153) and at-risk (n = 116) parents who completed the brief COPE, the Family Adaptability and Cohesion Scales and the Parenting Stress Index-Short Form. Confirmatory factor analysis, internal consistency, cross sample invariance, convergent and discriminant validity were analysed. Data from the confirmatory factor analysis revealed that the 14-factor model obtained the best fit. The results provided evidence that the Brief COPE is a psychometrically sound instrument that shows measurement invariance across samples and good reliability. Our findings demonstrated that the Portuguese version of brief COPE is a useful, time-efficient tool for both practitioners and researchers who need to assess coping strategies, a relevant construct in family context.


Assuntos
Adaptação Psicológica , Humanos , Portugal , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários
18.
Neuron ; 109(5): 823-838.e6, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33476548

RESUMO

The circuit mechanisms underlying fear-induced suppression of feeding are poorly understood. To help fill this gap, mice were fear conditioned, and the resulting changes in synaptic connectivity among the locus coeruleus (LC), the parabrachial nucleus (PBN), and the central nucleus of amygdala (CeA)-all of which are implicated in fear and feeding-were studied. LC neurons co-released noradrenaline and glutamate to excite PBN neurons and suppress feeding. LC neurons also suppressed inhibitory input to PBN neurons by inducing heterosynaptic, endocannabinoid-dependent, long-term depression of CeA synapses. Blocking or knocking down endocannabinoid receptors in CeA neurons prevented fear-induced depression of CeA synaptic transmission and fear-induced suppression of feeding. Altogether, these studies demonstrate that LC neurons play a pivotal role in modulating the circuitry that underlies fear-induced suppression of feeding, pointing to new ways of alleviating stress-induced eating disorders.


Assuntos
Medo/fisiologia , Comportamento Alimentar/fisiologia , Locus Cerúleo/fisiologia , Neurônios/fisiologia , Animais , Núcleo Central da Amígdala/fisiologia , Condicionamento Clássico , Feminino , Ácido Glutâmico/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologia , Norepinefrina/fisiologia , Núcleos Parabraquiais/fisiologia , Transmissão Sináptica
19.
J Neurosci ; 29(35): 11011-9, 2009 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-19726659

RESUMO

Dopaminergic neurons of the substantia nigra pars compacta are autonomous pacemakers. This activity is responsible for the sustained release of dopamine necessary for the proper functioning of target structures, such as the striatum. Somatodendritic L-type Ca2+ channels have long been viewed as important, if not necessary, for this activity. The studies reported here challenge this viewpoint. Using a combination of optical and electrophysiological approaches in brain slices, it was found that antagonism of L-type Ca2+ channel effectively stopped dendritic Ca2+ oscillations but left autonomous pacemaking unchanged. Moreover, damping intracellular Ca2+ oscillations with exogenous buffer had little effect on pacemaking rate. Although not necessary for pacemaking, L-type channels helped support pacemaking when challenged with cationic channel blockers. Simulations suggested that the insensitivity to antagonism of L-type channels reflected the multichannel nature of the pacemaking process. The robustness of pacemaking underscores its biological importance and provides a framework for understanding how therapeutics targeting L-type Ca2+ channels might protect dopaminergic neurons in Parkinson's disease without compromising their function.


Assuntos
Potenciais de Ação/fisiologia , Relógios Biológicos/fisiologia , Dopamina/fisiologia , Neurônios/fisiologia , Substância Negra/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL
20.
PLoS One ; 15(11): e0241900, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33152042

RESUMO

We present evidence of pupil response modification, as well as differential theoretical melatonin suppression through selective and dynamic electrochromic filtering of visible light in the 400-500 nm range to minimize chronodisruptive nocturnal blue light exposure. A lower activation of intrinsically photosensitive retinal ganglion cells (ipRGCs), the first step for light to reach a human's internal clock, is related to melatonin secretion therefore avoiding detrimental effects of excessive blue light exposure. Pupillary Light Reflex and Color Naming were experimentally assessed under light filtered by two different coloration states (transmissive and absorptive) of these novel dynamic filters, plus an uncoated test device, in 16 volunteers. Also, different commercial light sources at illuminances ranging from 1 to 1000 lux were differentially filtered and compared in terms of theoretical melatonin suppression. Representative parameters of the pupil responses reflected lower pupil constriction when the electrochromic filters (ECFs) were switched on (absorptive state, blue light is absorbed by the filter) compared to uncoated filters (control sample), but failed to do so under transmissive state (blue light passes through the filter) indicating less activation of ipRGCs under absorptive state (although no significant differences between states was found). Out of eight colors tested, just one showed significant differences in naming between both filter states. Thus, the ECF would have some protecting effect on ipRGC activation with very limited changes in color perception. While there are some limitations of the theoretical model used, the absorptive state yielded significantly lower theoretical melatonin suppression in all those light sources containing blue wavelengths across the illuminance range tested. This would open the way for further research on biological applications of electrochromic devices.


Assuntos
Pupila/fisiologia , Reflexo Pupilar/fisiologia , Células Ganglionares da Retina/fisiologia , Adulto , Cor , Feminino , Humanos , Luz , Masculino , Melatonina/metabolismo , Pessoa de Meia-Idade , Estimulação Luminosa/métodos
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