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1.
Small ; 20(29): e2310576, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38402439

RESUMO

In search for novel materials to replace noble metal-based electrocatalysts in electrochemical energy conversion and storage devices, special attention is given to a distinct class of materials, MAX phase that combines advantages of ceramic and metallic properties. Herein, Nb4AlC3 MAX phase is prepared by a solid-state mixing reaction and characterized morphologically and structurally by transmission and scanning electron microscopy with energy-dispersive X-ray spectroscopy, nitrogen-sorption, X-ray diffraction analysis, X-ray photoelectron and Raman spectroscopy. Electrochemical performance of Nb4AlC3 in terms of capacitance as well as for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) is evaluated in different electrolytes. The specific capacitance Cs of 66.4, 55.0, and 46.0 F g-1 at 5 mV s-1 is determined for acidic, neutral and alkaline medium, respectively. Continuous cycling reveals high capacitance retention in three electrolyte media; moreover, increase of capacitance is observed in acidic and neutral media. The electrochemical impedance spectroscopy showed a low charge transfer resistance of 64.76 Ω cm2 that resulted in better performance for HER in acidic medium (Tafel slope of 60 mV dec-1). In alkaline media, the charge storage value in the double layer is 360 mF cm-2 (0.7 V versus reversible hydrogen electrode) and the best ORR performance of the Nb4AlC3 is achieved in this medium (Tafel slope of 126 mV dec-1).

2.
Int J Mol Sci ; 25(13)2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-39000518

RESUMO

While obesity-related nonalcoholic fatty liver disease (NAFLD) is linked with metabolic dysfunctions such as insulin resistance and adipose tissue inflammation, lean NAFLD more often progresses to liver fibrosis even in the absence of metabolic syndrome. This review aims to summarize the current knowledge regarding the mechanisms of liver fibrosis in lean NAFLD. The most commonly used lean NAFLD models include a methionine/choline-deficient (MCD) diet, a high-fat diet with carbon tetrachloride (CCl4), and a high-fructose and high-cholesterol diet. The major pro-fibrogenic mechanisms in lean NAFLD models include increased activation of the extracellular signal-regulated kinase (ERK) pathway, elevated expression of α-smooth muscle actin (α-SMA), collagen type I, and TGF-ß, and modulation of fibrogenic markers such as tenascin-X and metalloproteinase inhibitors. Additionally, activation of macrophage signaling pathways promoting hepatic stellate cell (HSC) activation further contributes to fibrosis development. Animal models cannot cover all clinical features that are evident in patients with lean or obese NAFLD, implicating the need for novel models, as well as for deeper comparisons of clinical and experimental studies. Having in mind the prevalence of fibrosis in lean NAFLD patients, by addressing specific pathways, clinical studies can reveal new targeted therapies along with novel biomarkers for early detection and enhancement of clinical management for lean NAFLD patients.


Assuntos
Cirrose Hepática , Hepatopatia Gordurosa não Alcoólica , Obesidade , Humanos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Obesidade/metabolismo , Obesidade/complicações , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Cirrose Hepática/etiologia , Animais , Células Estreladas do Fígado/metabolismo , Modelos Animais de Doenças
3.
Curr Issues Mol Biol ; 45(11): 9084-9102, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37998747

RESUMO

The central mechanism involved in the pathogenesis of MAFLD is insulin resistance with hyperinsulinemia, which stimulates triglyceride synthesis and accumulation in the liver. On the other side, triglyceride and free fatty acid accumulation in hepatocytes promotes insulin resistance via oxidative stress, endoplasmic reticulum stress, lipotoxicity, and the increased secretion of hepatokines. Cytokines and adipokines cause insulin resistance, thus promoting lipolysis in adipose tissue and ectopic fat deposition in the muscles and liver. Free fatty acids along with cytokines and adipokines contribute to insulin resistance in the liver via the activation of numerous signaling pathways. The secretion of hepatokines, hormone-like proteins, primarily by hepatocytes is disturbed and impairs signaling pathways, causing metabolic dysregulation in the liver. ER stress and unfolded protein response play significant roles in insulin resistance aggravation through the activation of apoptosis, inflammatory response, and insulin signaling impairment mediated via IRE1/PERK/ATF6 signaling pathways and the upregulation of SREBP 1c. Circadian rhythm derangement and biological clock desynchronization are related to metabolic disorders, insulin resistance, and NAFLD, suggesting clock genes as a potential target for new therapeutic strategies. This review aims to summarize the mechanisms of hepatic insulin resistance involved in NAFLD development and progression.

4.
Molecules ; 27(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36364154

RESUMO

The new 3D coordination polymer (CP) [Mn(L)(HCOO)]n (Mn-CP) [L = 4-(pyridin-4-ylcarbamoyl)benzoate] was synthesised via a hydrothermal reaction using the pyridyl amide functionalized benzoic acid HL. It was characterized by elemental, FT-IR spectroscopy, single-crystal and powder X-ray diffraction (PXRD) analyses. Its structural features were disclosed by single-crystal X-ray diffraction analysis, which revealed a 3D structure with the monoclinic space group P21/c. Its performance as an electrocatalyst for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution (HER) reactions was tested in both acidic (0.5 M H2SO4) and alkaline (0.1 M KOH) media. A distinct reduction peak was observed at 0.53 V vs. RHE in 0.1 M KOH, which corresponds to the oxygen reduction, thus clearly demonstrating the material's activity for the ORR. Tafel analysis revealed a Tafel slope of 101 mV dec-1 with mixed kinetics of 2e- and 4e- pathways indicated by the Koutecky-Levich analysis. Conversely, the ORR peak was not present in 0.5 M H2SO4 indicating no activity of Mn-CP for this reaction in acidic media. In addition, Mn-CP demonstrated a noteworthy activity toward OER and HER in acidic media, in contrast to what was observed in 0.1 M KOH.


Assuntos
Amidas , Polímeros , Espectroscopia de Infravermelho com Transformada de Fourier , Oxigênio , Hidrogênio
5.
Microsc Microanal ; 26(5): 997-1006, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32782033

RESUMO

Nonalcoholic fatty liver disease (NAFLD) represents a hepatic manifestation of metabolic syndrome. The aim of this study was to examine the effect of betaine on ultrastructural changes in the mouse liver with methionine- and choline-deficient (MCD) diet-induced NAFLD. Male C57BL/6 mice were divided into groups: Control-fed with standard chow, BET-standard chow supplemented with betaine (1.5% w/v drinking water), MCD-fed with MCD diet, and MCD + BET-MCD diet with betaine supplementation for 6 weeks. Liver samples were taken for pathohistology and transmission electron microscopy. The MCD diet-induced steatosis, inflammation, and balloon-altered hepatocytes were alleviated by betaine. MCD diet induced an increase in mitochondrial size versus the control group (p < 0.01), which was decreased in the betaine-treated group. In the MCD diet-fed group, the total mitochondrial count decreased versus the control group (p < 0.01), while it increased in the MCD + BET group versus MCD (p < 0.01). Electron microscopy showed an increase in the number of autophagosomes in the MCD and MCD + BET group versus control, and a significant difference in autophagosomes number was detected in the MCD + BET group by comparison with the MCD diet-treated group (p < 0.05). Betaine decreases the number of enlarged mitochondria, alleviates steatosis, and increases the number of autophagosomes in the liver of mice with NAFLD.


Assuntos
Betaína/farmacologia , Colina/metabolismo , Dieta , Suplementos Nutricionais , Fígado/efeitos dos fármacos , Fígado/ultraestrutura , Metionina/deficiência , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Colágeno , Modelos Animais de Doenças , Hepatócitos/efeitos dos fármacos , Hepatócitos/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos C57BL
6.
Can J Physiol Pharmacol ; 97(2): 120-129, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30673308

RESUMO

In high-fat diet (HFD) induced nonalcoholic fatty liver disease (NAFLD), there is an increase in the endocannabinoid system activity, which significantly contributes to steatosis development. The aim of our study was to investigate the effects of cannabinoid receptor type 1 blockade on adipokine and proinflammatory cytokine content in adipose and hepatic tissue in mice with NAFLD. Male mice C57BL/6 were divided into a control group fed with a control diet for 20 weeks (C, n = 6) a group fed with a HFD for 20 weeks (HF, n = 6), a group fed with a control diet and treated with rimonabant after 18 weeks (R, n = 9), and a group fed with HFD and treated with rimonabant after 18 weeks (HFR, n = 10). Rimonabant significantly decreased leptin, resistin, apelin, visfatin, interleukin 6 (IL-6), and interferon-γ (IFN-γ) concentration in subcutaneous and visceral adipose tissue in the HFR group compared to the HF group (p < 0.01). Rimonabant reduced hepatic IL-6 and IFN-γ concentration as well as plasma glucose and insulin concentration and the homeostatic model assessment index in the HFR group compared to the HF group (p < 0.01). It can be concluded that the potential usefulness of CB1 blockade in the treatment of HFD-induced NAFLD is due to modulation of the adipokine profile and proinflammatory cytokines in both adipose tissues and liver as well as glucose metabolism.


Assuntos
Antagonistas de Receptores de Canabinoides/farmacologia , Citocinas/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Receptor CB1 de Canabinoide/antagonistas & inibidores , Rimonabanto/farmacologia , Adipocinas/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Glicemia/efeitos dos fármacos , Antagonistas de Receptores de Canabinoides/uso terapêutico , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Glucose/metabolismo , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Rimonabanto/uso terapêutico
7.
Microsc Microanal ; 24(2): 132-138, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29350612

RESUMO

The effects of betaine on hepatocytes chromatin architecture changes were examined by using fractal and gray-level co-occurrence matrix (GLCM) analysis in methionine/choline-deficient (MCD) diet-induced, nonalcoholic fatty liver disease (NAFLD). Male C57BL/6 mice were divided into groups: (1) Control: standard diet; (2) BET: standard diet and betaine supplementation through drinking water (solution 1.5%); (3) MCD group: MCD diet for 6 weeks; (4) MCD+BET: fed with MCD diet + betaine for 6 weeks. Liver tissue was collected for histopathology, immunohistochemistry, and determination of fractal dimension and GLCM parameters. MCD diet induced diffuse micro- and macrovesicular steatosis accompanied with increased Ki67-positive hepatocyte nuclei. Steatosis and Ki67 immunopositivity were less prominent in the MCD+BET group compared with the MCD group. Angular second moment (ASM) and inverse difference moment (IDM) (textural homogeneity markers) were significantly increased in the MCD+BET group versus the MCD group (p<0.001), even though no difference between the MCD and the control group was evident. Heterogeneity parameters, contrast, and correlation were significantly increased in the MCD group versus the control (p<0.001). On the other hand, betaine treatment significantly reduced correlation, contrast, and entropy compared with the MCD group (p<0.001). Betaine attenuated MCD diet-induced NAFLD by reducing fat accumulation and inhibiting hepatocyte proliferation. Betaine supplementation increased nuclear homogeneity and chromatin complexity with reduction of entropy, contrast, and correlation.


Assuntos
Betaína/administração & dosagem , Núcleo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromatina/efeitos dos fármacos , Fármacos Gastrointestinais/administração & dosagem , Hepatócitos/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Animais , Modelos Animais de Doenças , Hepatócitos/fisiologia , Histocitoquímica , Imuno-Histoquímica , Antígeno Ki-67/análise , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/patologia
8.
Gen Physiol Biophys ; 35(3): 363-70, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27174897

RESUMO

Choline and methionine are precursors of acetylcholine, whose hydrolysis is catalyzed by acetylcholinesterase (AChE). Considering the possibility of their common deficiency, we investigated the influence of methionine-choline deprivation on AChE activity in liver and various brain regions (hypothalamus, hippocampus, cerebral cortex and striatum) in mice fed with methionine-choline deficient (MCD) diet. Male C57BL/6 mice (n = 28) were randomly and equally divided into following groups: control group fed with standard diet for 6 weeks (C) and groups fed with MCD diet for 2 weeks (MCD2), 4 weeks (MCD4) and for 6 weeks (MCD6). After the diet, mice were sacrificied and AChE activity in liver and brain was determined spectrophotometrically. Hepatic AChE activity was higher in MCD2, MCD4 and MCD6 compared to control (p < 0.01), with most prominent increase in MCD6. AChE activity in hypothalamus was higher in MCD4 and MCD6 vs. control (p < 0.05 and p < 0.01, respectively), as well as in MCD6 compared to MCD4 (p < 0.01). In hippocampus, increase in AChE activity was shown in MCD6 compared to control (p < 0.01). In cortex and striatum, increase in AChE activity was noted in MCD6 compared to control (p < 0.05). Our findings indicate the increase of hepatic and brain AChE activity in mice caused by methionine-choline deprivation.


Assuntos
Acetilcolinesterase/metabolismo , Encéfalo/enzimologia , Deficiência de Colina/metabolismo , Fígado/enzimologia , Metionina/deficiência , Hepatopatia Gordurosa não Alcoólica/metabolismo , Animais , Ativação Enzimática , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Distribuição Tecidual
9.
Am J Physiol Gastrointest Liver Physiol ; 307(9): G931-40, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25104500

RESUMO

Neurosteroids are involved in the pathogenesis of hepatic encephalopathy (HE). This study evaluated the effects of finasteride, inhibitor of neurosteroid synthesis, on motor, EEG, and cellular changes in rat brain in thioacetamide-induced HE. Male Wistar rats were divided into the following groups: 1) control; 2) thioacetamide-treated group, TAA (300 mg·kg(-1)·day(-1)); 3) finasteride-treated group, FIN (50 mg·kg(-1)·day(-1)); and 4) group treated with FIN and TAA (FIN + TAA). Daily doses of TAA and FIN were administered in three subsequent days intraperitoneally, and in the FIN + TAA group FIN was administered 2 h before every dose of TAA. Motor and reflex activity was determined at 0, 2, 4, 6, and 24 h, whereas EEG activity was registered about 24 h after treatment. The expressions of neuronal (NeuN), astrocytic [glial fibrilary acidic protein (GFAP)], microglial (Iba1), and oligodendrocyte (myelin oligodendrocyte glycoprotein) marker were determined 24 h after treatment. While TAA decreased all tests, FIN pretreatment (FIN + TAA) significantly improved equilibrium, placement test, auditory startle, head shake reflex, motor activity, and exploratory behavior vs. the TAA group. Vital reflexes (withdrawal, grasping, righting and corneal reflex) together with mean EEG voltage were significantly higher (P < 0.01) in the FIN + TAA vs. the TAA group. Hippocampal NeuN expression was significantly lower in TAA vs. control (P < 0.05). Cortical Iba1 expression was significantly higher in experimental groups vs. control (P < 0.05), whereas hippocampal GFAP expression was increased in TAA and decreased in the FIN + TAA group vs. control (P < 0.05). Finasteride improves motor and EEG changes in TAA-induced HE and completely prevents the development of hepatic coma.


Assuntos
Encéfalo/fisiopatologia , Finasterida/uso terapêutico , Encefalopatia Hepática/tratamento farmacológico , Locomoção , Animais , Antígenos Nucleares/genética , Antígenos Nucleares/metabolismo , Encéfalo/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Eletroencefalografia , Comportamento Exploratório , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Encefalopatia Hepática/induzido quimicamente , Encefalopatia Hepática/metabolismo , Encefalopatia Hepática/fisiopatologia , Fígado/patologia , Masculino , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Glicoproteína Mielina-Oligodendrócito/genética , Glicoproteína Mielina-Oligodendrócito/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Wistar , Reflexo , Tioacetamida
10.
Endocrine ; 85(1): 18-34, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38285412

RESUMO

Obesity is the best described risk factor for the development of non-alcoholic fatty liver disease (NAFLD)/metabolic dysfunction associated steatotic liver disease (MASLD) and polycystic ovary syndrome (PCOS) while the major pathogenic mechanism linking these entities is insulin resistance (IR). IR is primarily caused by increased secretion of proinflammatory cytokines, adipokines, and lipids from visceral adipose tissue. Increased fatty acid mobilization results in ectopic fat deposition in the liver which causes endoplasmic reticulum stress, mitochondrial dysfunction, and oxidative stress resulting in increased cytokine production and subsequent inflammation. Similarly, IR with hyperinsulinemia cause hyperandrogenism, the hallmark of PCOS, and inflammation in the ovaries. Proinflammatory cytokines from both liver and ovaries aggravate IR thus providing a complex interaction between adipose tissue, liver, and ovaries in inducing metabolic abnormalities in obese subjects. Although many pathogenic mechanisms of IR, NAFLD/MASLD, and PCOS are known, there is still no effective therapy for these entities suggesting the need for further evaluation of their pathogenesis. Extracellular vesicles (EVs) represent a novel cross-talk mechanism between organs and include membrane-bound vesicles containing proteins, lipids, and nucleic acids that may change the phenotype and function of target cells. Adipose tissue releases EVs that promote IR, the development of all stages of NAFLD/MASLD and PCOS, while mesenchymal stem cell-derived AVs may alleviate metabolic abnormalities and may represent a novel therapeutic device in NAFLD/MASLD, and PCOS. The purpose of this review is to summarize the current knowledge on the role of adipose tissue-derived EVs in the pathogenesis of IR, NAFLD/MASLD, and PCOS.


Assuntos
Tecido Adiposo , Vesículas Extracelulares , Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Síndrome do Ovário Policístico , Humanos , Síndrome do Ovário Policístico/metabolismo , Feminino , Resistência à Insulina/fisiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Vesículas Extracelulares/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Animais , Obesidade/metabolismo , Obesidade/complicações
11.
Endocrine ; 85(3): 1050-1057, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38635064

RESUMO

Neuroactive steroids are a type of steroid hormones produced within the nervous system or in peripheral glands and then transported to the brain to exert their neuromodulatory effects. Neuroactive steroids have pleiotropic effects, that include promoting myelination, neuroplasticity, and brain development. They also regulate important physiological functions, such as metabolism, feeding, reproduction, and stress response. The homoeostatic processes of metabolism and reproduction are closely linked and mutually dependent. Reproductive events, such as pregnancy, bring about significant changes in metabolism, and metabolic status may affect reproductive function in mammals. In females, the regulation of reproduction and energy balance is controlled by the fluctuations of oestradiol and progesterone throughout the menstrual cycle. Neurosteroids play a key role in the neuroendocrine control of reproduction. The synthesis of neuroestradiol and neuroprogesterone within the brain is a crucial process that facilitates the release of GnRH and LH, which in turn, regulate the transition from oestrogen-negative to oestrogen-positive feedback. In addition to their function in the reproductive system, oestrogen has a key role in the regulation of energy homoeostasis by acting at central and peripheral levels. The oestrogenic effects on body weight homoeostasis are primarily mediated by oestrogen receptors-α (ERα), which are abundantly expressed in multiple brain regions that are implicated in the regulation of food intake, basal metabolism, thermogenesis, and brown tissue distribution. The tight interplay between energy balance and reproductive physiology is facilitated by shared regulatory pathways, namely POMC, NPY and kisspeptin neurons, which are targets of oestrogen regulation and likely participate in different aspects of the joint control of energy balance and reproductive function. The aim of this review is to present a summary of the progress made in uncovering shared regulatory pathways that facilitate the tight coupling between energy balance and reproductive physiology, as well as their reciprocal interactions and the modulation induced by neurosteroids.


Assuntos
Ingestão de Alimentos , Metabolismo Energético , Neuroesteroides , Reprodução , Humanos , Reprodução/fisiologia , Animais , Ingestão de Alimentos/fisiologia , Metabolismo Energético/fisiologia , Metabolismo Energético/efeitos dos fármacos , Neuroesteroides/metabolismo , Sistemas Neurossecretores/fisiologia , Sistemas Neurossecretores/metabolismo , Sistemas Neurossecretores/efeitos dos fármacos , Feminino , Encéfalo/metabolismo , Encéfalo/fisiologia
12.
Chem Biol Interact ; 394: 110996, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38593908

RESUMO

Diabetic retinopathy is not cured efficiently and changes of lifestyle measures may delay early retinal injury in diabetes. The aim of our study was to investigate the effects of reduced daily light exposure on retinal vascular changes in streptozotocin (STZ)-induced model of DM with emphasis on inflammation, Aqp4 expression, visual cycle and cholesterol metabolism-related gene expression in rat retina and RPE. Male Wistar rats were divided into the following groups: 1. control; 2. diabetic group (DM) treated with streptozotocin (100 mg/kg); 3. group exposed to light/dark cycle 6/18 h (6/18); 4. diabetic group exposed to light/dark cycle 6/18 h (DM+6/18). Retinal vascular abnormalities were estimated based on lectin staining, while the expression of genes involved in the visual cycle, cholesterol metabolism, and inflammation was determined by qRT-PCR. Reduced light exposure alleviated vasculopathy, gliosis and the expression of IL-1 and TNF-α in the retina with increased perivascular Aqp4 expression. The expression of genes involved in visual cycle and cholesterol metabolism was significantly up-regulated in RPE in DM+6/18 vs. DM group. In the retina only the expression of APOE was significantly higher in DM+6/18 vs. DM group. Reduced light exposure mitigates vascular changes and gliosis in DM via its anti-inflammatory effect, increased retinal cholesterol turnover and perivascular Aqp4 expression.


Assuntos
Colesterol , Diabetes Mellitus Experimental , Retinopatia Diabética , Gliose , Luz , Ratos Wistar , Retina , Estreptozocina , Animais , Masculino , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Retina/metabolismo , Retina/patologia , Retina/efeitos da radiação , Colesterol/metabolismo , Ratos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/complicações , Gliose/patologia , Gliose/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética , Anti-Inflamatórios/farmacologia , Aquaporina 4/metabolismo , Aquaporina 4/genética , Vasos Retinianos/metabolismo , Vasos Retinianos/patologia
13.
Gen Physiol Biophys ; 32(2): 277-83, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23682026

RESUMO

Moderate caloric restriction prolongs lifespan. Changes in oxidative stress and hormesis may be involved in this process. The aim of this study is to examine the effects of different levels of chronic caloric restriction (CR) and acute fasting on stress response and oxidative stress parameters in rat liver and plasma. Forty-two rats were divided into groups: control group, calorie-restricted groups with intake of 80-90%, 60-70%, 40-50%, 20-30% of daily caloric needs and acute fasting group. To determine alanine aminotransferase (ALT), aspartate aminotransferase (AST) and superoxide dismutase (SOD) activity, concentration of corticosterone, nitrites and nitrates (NOx), malondialdehyde (MDA) and glutathione (GSH), liver samples and blood were collected. Increase in plasma corticosterone concentration and AST and ALT activity was found in severe CR. Ingestion 40-50% daily caloric needs or less increased liver MDA and NOx concentration and decreased SOD activity. Ingestion 60-70% daily caloric needs increased Mn-SOD activity, GSH and NOx. In acute fasting group and group taking 20-30% daily caloric needs, GSH was significantly lower than in control group. Severe CR and acute fasting increase oxidative damage and decrease antioxidative capacity of hepatocytes. Moderate CR increases antioxidative capacity of hepatocytes due to increase in Mn-SOD activity and GSH concentration, which might have a role in anti-aging and hormetic mechanism of CR.


Assuntos
Restrição Calórica/métodos , Citocinas/sangue , Hormese/fisiologia , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/sangue , Animais , Masculino , Ratos , Ratos Wistar
14.
Telemat Inform ; 79: 101966, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36910674

RESUMO

To comprehend the nature, implications, risks and consequences of the events of the COVID-19 crisis, individuals largely relied on various online information sources. The features of online information exchange (e.g., conducted on a massive scale, with an abundance of information and unverified sources) led to various behavioral and psychological responses that are not fully understood. This study therefore investigated the relationship between exposure to online information sources and how individuals sought, forwarded, and provided COVID-19 related information. Anchored in the stimulus-organism-response model, cognitive load theory, and the theory of fear appeal, this study examined the link between the online consumption of COVID-19-related information and psychological and behavioral responses. In the theory development process, we hypothesized the moderating role of levels of fear. The research model included six hypotheses and was empirically verified on self-reported data (N = 425), which was collected in early 2021. The results indicate that continuous exposure to online information sources led to perceived information overload, which further heightened the psychological state of cyberchondria. Moreover, the act of seeking and providing COVID-19 information was significantly predicted by perceived cyberchondria. The results also suggest that higher levels of fear led to increased levels of seeking and providing COVID-19-related information. The theoretical and practical implications of these findings are presented, along with promising areas for future research.

15.
Heliyon ; 9(3): e14496, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36942240

RESUMO

Over the course of the COVID-19 pandemic, in addition to vaccination, health authorities have strongly advocated the wearing of face masks as a crucial measure in combating the virus. Nevertheless, the recommendation or legal requirement to wear a face mask is no guarantee of adherence to the rules. A person's decision to wear a mask may also be based on their beliefs and is likely to be influenced by their observation of the mask-wearing behavior of other people. This study aims to explore the role of conformity on the wearing of masks during the COVID-19 pandemic. Given that there is little evidence on how the mask-wearing behavior of others and demographic factors affect people's decisions to wear face masks in public settings, we performed a large-scale observational study in the Czech Republic during a period of rapidly increasing COVID-19 related cases and deaths. We observed a total of 1753 customers and 472 employees in 67 highly frequented shopping venues. The data were collected by trained observers and analyzed using multilevel logistic regression modeling. The results indicate that the mask-wearing behavior of new customers was influenced by the proportion of other customers wearing masks and the behavior differed according to the demographics of age and sex. A notable finding was that the greater the presence of customers wearing masks in a store, the lower the propensity of new visitors to wear masks. Which may be evidence of problematic free-riding behavior. These findings therefore have policy implications and can aid the formulation of specific (communication) strategies to promote mask-wearing behavior.

16.
Materials (Basel) ; 16(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37176270

RESUMO

A set of platinum (Pt) and earth-abundant transition metals (M = Ni, Fe, Cu) on graphene nanoplatelets (sqPtM/GNPs) was synthesised via sequential deposition to establish parallels between the synthesis method and the materials' electrochemical properties. sqPtM/GNPs were assessed as bifunctional electrocatalysts for oxygen evolution (OER) and reduction (ORR) reactions for application in unitised regenerative fuel cells and metal-air batteries. sqPtFe/GNPs showed the highest catalytic performance with a low potential difference of ORR half-wave potential and overpotential at 10 mA cm-2 during OER, a crucial parameter for bifunctional electrocatalysts benchmarking. A novel two-stage synthesis strategy led to higher electrocatalytic performance by facilitating the reactants' access to the active sites and reducing the charge-transfer resistance.

17.
J Pers Med ; 13(5)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37240914

RESUMO

The aim of our study was to investigate the effects of a shortened daily photoperiod on anxiety-like behaviour, brain oxidative stress, lipid status and fatty acid composition of serum lipids in a streptozotocin (STZ)-induced model of diabetes mellitus in rats. Male Wistar rats were divided into the following groups: first group-control group (C12/12); second group-diabetic group (DM12/12; 100 mg/kg STZ); third group-control group exposed to a light/dark cycle 6/18 h (C6/18); fourth group-diabetic group exposed to a light/dark cycle 6/18 h (DM6/18). Anxiety-like behaviour was tested three weeks following STZ injection by elevated plus maze (EPM) and open-field test (OFT). Oxidative stress parameters were measured in the cortex, hippocampus and thalamus, while lipid status and fatty acid methyl esters (FAMEs) were measured in the serum. Both EPM and OFT showed a lower degree of anxiety-like behaviour in the DM6/18 vs. DM12/12 group. Lipid peroxidation in the cortex, hippocampus and thalamus was significantly lower in the DM6/18 vs. DM12/12 group (p < 0.05), associated with an increased level of antioxidant enzymes and protein thiols in the cortex and thalamus. In the DM6/18 group, oleic, vaccenic, dihomo-γ-linolenic and docosahexaenoic acid concentrations were significantly higher in comparison to the DM12/12 group. A shortened daily photoperiod alleviates anxiety-like behaviour in diabetic rats by reduced lipid peroxidation and changes in the serum fatty acids profile.

18.
Oxid Med Cell Longev ; 2023: 3199988, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37064799

RESUMO

Pathogenesis of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) remains unclear since it represents an interplay between immunological, endocrine, and neuropsychiatric factors. Patients suffering from CP/CPPS often develop mental health-related disorders such as anxiety, depression, or cognitive impairment. The aim of this study was to investigate depression-like behavior, learning, and memory processes in a rat model of CP/CPPS and to determine the alterations in hippocampal structure and function. Adult male Wistar albino rats (n = 6 in each group) from CP/CPPS (single intraprostatic injection of 3% λ-carrageenan, day 0) and Sham (0.9% NaCl) groups were subjected to pain threshold test (days 2, 3, and 7), depression-like behavior, and learning-memory tests (both on day 7). Decreased pain threshold in the scrotal region and histopathological presence of necrosis and inflammatory infiltrate in prostatic tissue confirmed the development of CP/CPPS. The forced swimming test revealed the depression-like behavior evident through increased floating time, while the modified elevated plus maze test revealed learning and memory impairment through prolonged transfer latency in the CP/CPPS group in comparison with Sham (p < 0.001 and p < 0.001, respectively). Biochemical analysis showed decreased serum levels of testosterone in CP/CPPS group vs. the Sham (p < 0.001). The CP/CPPS induced a significant upregulation of ICAM-1 in rat cortex (p < 0.05) and thalamus (p < 0.01) and increased GFAP expression in the hippocampal astrocytes (p < 0.01) vs. Sham, suggesting subsequent neuroinflammation and astrocytosis. Moreover, a significantly decreased number of DCX+ and Ki67+ neurons in the hippocampus was observed in the CP/CPPS group (p < 0.05) vs. Sham, indicating decreased neurogenesis and neuronal proliferation. Taken together, our data indicates that CP/CPPS induces depression-like behavior and cognitive declines that are at least partly mediated by neuroinflammation and decreased neurogenesis accompanied by astrocyte activation.


Assuntos
Prostatite , Humanos , Animais , Ratos , Masculino , Prostatite/complicações , Prostatite/metabolismo , Astrócitos/metabolismo , Doença Crônica , Depressão/complicações , Doenças Neuroinflamatórias , Ratos Wistar , Dor Pélvica , Hipocampo/metabolismo , Neurogênese
19.
Can J Physiol Pharmacol ; 90(9): 1219-27, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22913436

RESUMO

The aim of our study was to investigate the behavioral and electroencephalographic manifestations of thioacetamide-induced encephalopathy in rats. Male Wistar rats were divided among (i) control, saline-treated, and (ii) thioacetamide-treated groups (TAA(300) (300 mg/kg body mass); TAA(600) (600 mg/kg); and TAA(900) (900 mg/kg)). The daily dose of thioacetamide (300 mg/kg) was administered intraperitoneally once (TAA(300)), twice (TAA(600)), or 3 times (TAA(900)), on subsequent days. Behavioral manifestations were determined at 0, 2, 4, 6, and 24 h, while electroencephalographic changes were recorded 22-24 h after the last dose. General motor activity and exploratory behavior, as well as head shake, auditory startle reflex, placement, and equlibrium tests were diminished in the TAA(600) and TAA(900) groups compared with the control, and were absent in the TAA(900) group 24 h after treatment. Corneal, withdrawal, grasping, and righting reflexes were significantly diminished in the TAA(900) group compared with the control. Mean electroencephalographic power spectra density was significantly higher in TAA(300) and TAA(600) and lower in the TAA(900) group by comparison with the control. Only a score of 3 (mean dominant frequency ≤ 7.3 Hz and δ relative power ≥ 45%) was observed in the TAA(900) group. Thioacetamide induces encephalopathy in rats in a dose-dependent manner. A dose of 900 mg/kg TAA may be used as a suitable model of all stages of hepatic encephalopathy.


Assuntos
Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Modelos Animais de Doenças , Encefalopatia Hepática/induzido quimicamente , Fígado/efeitos dos fármacos , Tioacetamida/farmacologia , Animais , Encéfalo/fisiopatologia , Relação Dose-Resposta a Droga , Eletroencefalografia , Encefalopatia Hepática/fisiopatologia , Encefalopatia Hepática/psicologia , Fígado/patologia , Masculino , Ratos , Ratos Wistar
20.
ScientificWorldJournal ; 11: 1582-90, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22224072

RESUMO

The increased thickness of the carotid wall >1 mm is a significant predictor of coronary and cerebrovascular diseases. The purpose of our study was to assess the agreement between multidetector row computed tomography angiography (MDCTA) in measuring carotid artery wall thickness (CAWT) and color Doppler ultrasound (CD-US) in measuring intimae-media thickness (IMT). Eighty-nine patients (aged 35-81) were prospectively analyzed using a 64-detector MDCTA and a CD-US scanner. Continuous data were described as the mean value ± standard deviation, and were compared using the Mann-Whitney U test. A p value <0.05 was considered significant. Bland-Altman statistics were employed to measure the agreement between MDCTA and CD-US. CAWT ranged from 0.62 to 1.60 mm, with a mean value of 1.09 mm. IMT ranged from 0.60 to 1.55 mm, with a mean value of 1.06 mm. We observed an excellent agreement between CD-US and MDCTA in the evaluation of the common carotid artery thickness, with a bias between methods of 0.029 mm (which is a highly statistically important difference of absolute values [t = 43.289; p < 0.01] obtained by paired T test), and limits of agreement from 0.04 to 0.104. Pearson correlation coefficient was 0.9997 (95% CI 0.9996-0.9998; p < 0.01). We conclude that there is an excellent correlation between CAWT and IMT measurements obtained with the MDCTA and CD-US.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Ultrassonografia Doppler em Cores , Adulto , Idoso , Idoso de 80 Anos ou mais , Espessura Intima-Media Carotídea , Estenose das Carótidas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
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