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1.
Biopolymers ; 113(8): e23519, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35633499

RESUMO

The aims of this study were to analyze the plasticizing effect of Apis mellifera honey on the mechanical, physicochemical and optical properties of whey protein isolate (WPI) films and to compare the results collected with the plasticizing effect of glycerol on WPI-films. Response surface was applied to optimize the amounts of WPI and glycerol in order to obtain films with higher tensile strength (TS), moderate elongation, and lower water vapor permeability so that they could be used as reference films. Honey was added at different concentrations (60%, 80%, and 100%) of g honey/100 g WPI, as a plasticizer to the WPI-films. In comparison to glycerol-plasticized films, an increase in the percentage of honey produced a reduction of 20 ± 10 to 48 ± 0.5% of TS, a 66 ± 0.5% lower in Young's modulus (WPI-films with 100% honey), and an increase of 186 ± 11% in elongation at break in the WPI-films with 100% honey. Honey-plasticized WPI-films were from 29 ± 11 to 43 ± 3% less permeable to water vapor than glycerol-plasticized WPI films. The mechanical characteristics of the 80% honey formulation did not differ significantly from those of the reference film (p > 0.05). Findings from this study indicate that honey has great potential as a plasticizer in WPI-films.


Assuntos
Abelhas , Mel , Plastificantes , Proteínas do Soro do Leite , Animais , Glicerol/química , Permeabilidade , Plastificantes/química , Vapor , Resistência à Tração , Proteínas do Soro do Leite/química
2.
J Food Sci Technol ; 58(5): 1918-1926, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33897028

RESUMO

The objective of this work was to evaluate the effect of freeze-dried pulps of Eugenia uniflora L. and Opuntia ficus-indica fruits on oxidative stability of n-3-enriched beef patties. Besides, the effect of freeze-dried pulps on cooking yield, color, texture parameters and sensory acceptance of patties was also evaluated. Eugenia uniflora L. (orange-skinned variety) and Opuntia ficus-indica (orange-skinned and red-skinned varieties) fruits were collected, their pulp was lyophilized and incorporated, as a natural source of antioxidant, in beef patties enriched with canola oil as a source of polyunsaturated fatty acids. Oxidation stability of samples was monitored by measuring thiobarbituric acid-reactive substances during refrigerated storage. Results show that all freeze-dried pulps limited lipid oxidation to an acceptable level during 15 days refrigerated storage, having Opuntia ficus-indica (red-skinned variety) the highest inhibitory activity. Besides, the addition of freeze-dried pulps increased the cooking yield and decreased the hardness of beef patties. Respect to sensorial parameters, patties elaborated with no added freeze-dried fruit pulp and patties elaborated with freeze-dried pulp of Opuntia ficus-indica (red-skinned variety) presented the highest overall acceptance of consumers, remaining as a future task to improve the color and taste of patties elaborated with freeze-dried pulps of Eugenia uniflora L. and Opuntia ficus-indica (orange-skinned variety). This research reveals the effectiveness of studied fruits to reduce lipid oxidation in beef patties. In addition, preliminary information about which sensorial parameters of these products should be improved in futures incorporation of pulps in the manufacture of healthy meat products.

3.
Skin Pharmacol Physiol ; 33(5): 237-243, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33070140

RESUMO

BACKGROUND: The use of antioxidants has become a common practice in the development of antiaging cosmetics. OBJECTIVE: The aim of this study was to evaluate the clinical efficacy of cosmetic formulations containing lycopene and melatonin antioxidants. METHOD: Thirty-six healthy women from 32 to 65 years were enrolled in this study. The study was carried out for 10 weeks, 2 preconditioning weeks with a control cream without antioxidants, and 8-week test with creams containing antioxidants in study. A multifunctional skin physiology monitor (Courage & Khazaka electronic GmbH®, Germany) was used to measure skin sebum content, hydration, elasticity, erythema index, and melanin index in 4 different regions of the face. RESULTS: There were significant differences between them.


Assuntos
Antioxidantes/administração & dosagem , Cosméticos/administração & dosagem , Licopeno/administração & dosagem , Melatonina/administração & dosagem , Creme para a Pele/administração & dosagem , Fenômenos Fisiológicos da Pele/efeitos dos fármacos , Adulto , Idoso , Antioxidantes/metabolismo , Cosméticos/metabolismo , Combinação de Medicamentos , Composição de Medicamentos , Feminino , Humanos , Licopeno/metabolismo , Melatonina/metabolismo , Pessoa de Meia-Idade , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/fisiologia , Creme para a Pele/metabolismo
4.
J Food Sci Technol ; 55(3): 858-867, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29487427

RESUMO

The improvement of fatty acids (FA) profile of bread made with bovine fat (BF) and a mixture of flours completely replacing fat with canola oil (CO), or olive oil (OO) was evaluated. Technological and sensory characteristics and overall acceptability of the fortified breads were also studied. The results showed a decrease in saturated FA and a relative increase in monounsaturated and polyunsaturated FA compared to bread made with BF. Regarding CO, this caused the higher increase in n3 FA. This effect was maximized in bread made from the mixture of wheat flour (WF) + flaxseed flour (FF) + soybean flour (SF). OO caused a rise of n9 and n6 FA, mainly in bread made with WF + FF + wheat bran (WB). The breads with WF + FF + SF + CO and WF + FF + WB + OO presented higher specific volume, softer crumb and colour similar to those from base formulations. Furthermore, they had a very good sensory acceptance.

5.
J Food Sci Technol ; 55(5): 1889-1902, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29666542

RESUMO

The goal of this study was to develop a fish-based product suitable for people with celiac disease. Water and gluten-free flours (rice, corn, amaranth or quinoa) were added to improve cooking yield, texture parameters and as an aid in improving quality attributes such as taste and juiciness. Cooking yields of patties containing gluten-free flours were higher than control and maximum values ranged between 91 and 93%. Hardness was higher in patties made with amaranth or quinoa flour, whereas cohesiveness and springiness were higher in patties made with corn and rice flour, respectively. Response surface methodology was used to optimize patties formulations. Optimized formulations were prepared and evaluated showing a good agreement between predicted and experimental responses. Also, nutritional value and consumer acceptance of optimized formulations were analysed. Flours addition affected proximate composition increasing carbohydrates, total fat and mineral content compared to control. Sensory evaluation showed that no differences were found in the aroma of products. Addition of rice flour increased juiciness and tenderness whereas taste, overall acceptance and buying intention were higher in control patty, followed by patties made with corn flour. The present investigation shows good possibilities for further product development, including the scale up at an industrial level.

6.
RNA Biol ; 14(6): 712-725, 2017 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-27627892

RESUMO

Cajal is commonly regarded as the father of modern neuroscience in recognition of his fundamental work on the structure of the nervous system. But Cajal also made seminal contributions to the knowledge of nuclear structure in the early 1900s, including the discovery of the "accessory body" later renamed "Cajal body" (CB). This important nuclear structure has emerged as a center for the assembly of ribonucleoproteins (RNPs) required for splicing, ribosome biogenesis and telomere maintenance. The modern era of CB research started in the 1990s with the discovery of coilin, now known as a scaffold protein of CBs, and specific probes for small nuclear RNAs (snRNAs). In this review, we summarize what we have learned in the recent decades concerning CBs in post-mitotic neurons, thereby ruling out dynamic changes in CB functions during the cell cycle. We show that CBs are particularly prominent in neurons, where they frequently associate with the nucleolus. Neuronal CBs are transcription-dependent nuclear organelles. Indeed, their number dynamically accommodates to support the high neuronal demand for splicing and ribosome biogenesis required for sustaining metabolic and bioelectrical activity. Mature neurons have canonical CBs enriched in coilin, survival motor neuron protein and snRNPs. Disruption and loss of neuronal CBs associate with severe neuronal dysfunctions in several neurological disorders such as motor neuron diseases. In particular, CB depletion in motor neurons seems to reflect a perturbation of transcription and splicing in spinal muscular atrophy, the most common genetic cause of infant mortality.


Assuntos
Corpos Enovelados/metabolismo , Neurônios/metabolismo , Animais , Nucléolo Celular/metabolismo , Suscetibilidade a Doenças , Humanos , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/metabolismo , Doenças do Sistema Nervoso/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Transporte Proteico , Splicing de RNA , RNA Nuclear Pequeno/genética , RNA Nuclear Pequeno/metabolismo , Ribonucleoproteínas Nucleares Pequenas/metabolismo
7.
Anal Bioanal Chem ; 409(15): 3891-3898, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28365870

RESUMO

A new system for continuous flow chemiluminescence detection, based on the use of a simple and low-priced lens-free digital camera (with complementary metal oxide semiconductor technology) as a detector, is proposed for the quantitative determination of paracetamol in commercial pharmaceutical formulations. Through the camera software, AVI video files of the chemiluminescence emission are captured and then, using friendly ImageJ public domain software (from National Institutes for Health), properly processed in order to extract the analytical information. The calibration graph was found to be linear over the range 0.01-0.10 mg L-1 and over the range 1.0-100.0 mg L-1 of paracetamol, the limit of detection being 10 µg L-1. No significative interferences were found. Paracetamol was determined in three different pharmaceutical formulations: Termalgin®, Efferalgan® and Gelocatil®. The obtained results compared well with those declared on the formulation label and with those obtained through the official analytical method of British Pharmacopoeia. Graphical abstract Abbreviated scheme of the new chemiluminescence detection system proposed in this paper.


Assuntos
Acetaminofen/análise , Analgésicos não Narcóticos/análise , Medições Luminescentes/instrumentação , Gravação em Vídeo/instrumentação , Desenho de Equipamento , Limite de Detecção , Medições Luminescentes/economia , Medições Luminescentes/métodos , Metais/química , Óxidos/química , Semicondutores , Comprimidos , Gravação em Vídeo/economia , Gravação em Vídeo/métodos
8.
Cir Esp ; 94(8): 460-6, 2016 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27461232

RESUMO

INTRODUCTION: Preoperative short-course radiotherapy with immediate surgery improves local control in patients with rectal cancer. Tumor responses are smaller than those described with radiochemotherapy. Preliminary data associate this lower response to the short period until surgery. The aim of this study is to analyze the response to preoperative short-course radiotherapy and its correlation with the interval to surgery especially analyzing patients with mesorectal fascia involvement. METHODS: A total of 155 patients with locally advanced rectal cancer treated with preoperative radiotherapy (5×5Gy) were retrospectively analyzed. Tumor response in terms of rates of complete pathological response, downstaging, tumor regression grading and status of the circumferential resection margin were quantified. RESULTS: The mean interval from radiotherapy to surgery was 23 days. The rate of complete pathological response was 2.2% and 28% experienced downstaging (stage decreased). No differences between these rates and interval to surgery were detected. Eighty-eight patients had magnetic resonance imaging for staging (in 31 patients the mesorectal fascia was involved).The mean time to surgery in patients with involvement of the fascia and R0 surgery was 27 days and 16 days if R1 (P=.016). The cutoff of 20 days reached the highest probability of achieving a free circumferential resection margin between patients with mesorectal fascia involvement, with no statistically significant differences: RR 3.036 95% CI=(0.691-13.328), P=.06. CONCLUSIONS: After preoperative short-course radiotherapy, an interval>20 days enhances the likelihood of achieving a free circumferential resection margin in patients with mesorectal fascia involvement.


Assuntos
Neoplasias Retais/radioterapia , Neoplasias Retais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Fáscia/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Cuidados Pré-Operatórios , Neoplasias Retais/patologia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
9.
ScientificWorldJournal ; 2014: 401981, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25478592

RESUMO

Functional breads constitute an interesting alternative as vehicle of new essential fatty acids sources. The aim of this study was to improve the fatty acids (FA) profile of bakery products, producing breads with low saturated fatty acid (SFA) content and with high polyunsaturated fatty acid (PUFA) content, through partial substitution of wheat flour by other ingredients (soy flour, flax flour, and wheat bran) and to analyze the effect of this change on the technological, rheological, and sensorial characteristics of breads. Flaxseed flour (FF), soybeans flour (SF), or wheat bran (WB) was used to replace 50, 100, and 150 g kg(-1) of wheat flour (WF) in breads. FF or SF produced a decrease in monounsaturated and SFA and an increase of PUFA in these breads. Furthermore, breads replaced with FF presented considerable increase in the content of n3 FA, while, SF or WB contributed to rise of linoleic and oleic FA, respectively. The substitution percentage increase of FF, SF, or WB to formulation produced changes in the colour, rheological, textural, and technological characteristics of breads. This replacement resulted in improved lipid profile, being breads with 50 g kg(-1) SF, the better acceptance, baking features, and enhanced fatty acid profile.


Assuntos
Pão , Suplementos Nutricionais , Ácidos Graxos Insaturados/química , Fibras na Dieta , Ácidos Graxos Insaturados/isolamento & purificação , Linho/química , Humanos , Reologia , Glycine max/química
10.
Radiat Prot Dosimetry ; 199(15-16): 1743-1747, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37819344

RESUMO

Regular participation in intercomparisons (ICs) is an excellent way to test the reliability of results in laboratories. This work presents the analysis and conclusions of the results obtained by the CIEMAT dosimetry system in the last seven EURADOS ICs of whole-body dosemeters in fields of photons and beta radiation. Compliance with the criteria established in the ISO14146 standard, as well as the behavior of the CIEMAT personal dosemeters in all these ICs, has provided the necessary confidence for its use in the individual monitoring of workers during these years.


Assuntos
Exposição Ocupacional , Monitoramento de Radiação , Proteção Radiológica , Humanos , Monitoramento de Radiação/métodos , Doses de Radiação , Reprodutibilidade dos Testes , Proteção Radiológica/métodos , Radiometria/métodos , Fótons , Exposição Ocupacional/análise
11.
Psychol Rep ; : 332941221132995, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36219581

RESUMO

OBJECTIVE: To examine the relationship between self-compassion, compassion for others and Burnout in medical students and physicians. METHODS: A cross-sectional study was conducted. Medicine students and general physicians from two Colombian cities participated (n = 359). The Compassion Scales and the Maslach Inventory were administered. An Exploratory Structural Equation approach was used for validating new measures and testing for relationships between latent variables. RESULTS: Most participants were students (85.9%), mean age was 22 years (SD = 7), 55.2% were female, 62,6% dedicated more than 48 weekly hours to study or practice, while physicians had worked a mean of 10.34 years (SD = 8.67). Self-compassion and Compassion for others action subscales were validated, but engagement subscales of were not. Participant´s compassion actions for others and self-compassion actions are negatively related to depersonalization and emotional exhaustion, respectively. Additionally, compassion dimensions were positively associated with professional accomplishment. CONCLUSION: Our findings indicate that compassion and self-compassion actions inversely relate to different components of Burnout and could constitute protective factors against the stress of healthcare. Compassion and self-compassion training programs for medical students and physicians might be an alternative to avoid Burnout, diminishing physicians' depersonalization and emotional exhaustion while enhancing their professional accomplishment.

12.
Environ Technol ; 39(11): 1393-1403, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28537128

RESUMO

Wastewater management in developing countries is a challenge, especially in small towns with rapid population growth. This study aims at assessing the performance and management of five treatment plants (TPs) in rural areas of Cochabamba, Bolivia. Pollutants' concentrations, wastewater flows, hydraulic and organic loads and hydraulic retention times were determined in three small treatment plants (2000-10,000 population equivalent [p.e.]; flow > 432 m3/d) and two very small treatment plants (<2000 p.e.; flow < 432 m3/d). The performance assessment was based on operational parameters, treatment efficiency and effluent quality. Management data were collected through semi-structured interviews with managers of local water associations. The results support that the poor performance of the TPs is due to lack of operational expertise and financial resources for adequate operation and maintenance (O&M). Additionally, effective treatment was affected by the type of technology used and whether the plant design included plans for O&M with available resources. This study contributes to a better understanding of actual operating conditions of wastewater TPs in small towns, thus providing needed information regarding technology selection, design, implementation and operation.


Assuntos
Gerenciamento de Resíduos , Águas Residuárias , Bolívia , Eliminação de Resíduos Líquidos
13.
PLoS One ; 12(8): e0182796, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28796821

RESUMO

Information on whole community responses is needed to predict direction and magnitude of changes in plant and animal abundance under global changes. This study quantifies the effect of past ozone exposure on a weed community structure and arthropod colonization. We used the soil seed bank resulting from a long-term ozone exposure to reestablish the plant community under a new low-pollution environment. Two separate experiments using the same original soil seed bank were conducted. Plant and arthropod richness and species abundance was assessed during two years. We predicted that exposure to episodic high concentrations of ozone during a series of growing cycles would result in plant assemblies with lower diversity (lower species richness and higher dominance), due to an increase in dominance of the stress tolerant species and the elimination of the ozone-sensitive species. As a consequence, arthropod-plant interactions would also be changed. Species richness of the recruited plant communities from different exposure histories was similar (≈ 15). However, the relative abundance of the dominant species varied according to history of exposure, with two annual species dominating ozone enriched plots (90 ppb: Spergula arvensis, and 120 ppb: Calandrinia ciliata). Being consistent both years, the proportion of carnivore species was significantly higher in plots with history of higher ozone concentration (≈3.4 and ≈7.7 fold higher in 90 ppb and 120 ppb plots, respectively). Our study provides evidence that, past history of pollution might be as relevant as management practices in structuring agroecosystems, since we show that an increase in tropospheric ozone may influence biotic communities even years after the exposure.


Assuntos
Poluentes Atmosféricos/toxicidade , Ozônio/toxicidade , Plantas Daninhas/efeitos dos fármacos , Animais , Argentina , Artrópodes/fisiologia , Atmosfera , Biodiversidade , Cadeia Alimentar , Dispersão Vegetal , Plantas Daninhas/crescimento & desenvolvimento , Plantas Daninhas/parasitologia , Dinâmica Populacional
14.
Radiat Prot Dosimetry ; 170(1-4): 113-6, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26838064

RESUMO

Starting in 2008 the European Dosimetry Group (EURADOS) has been performing international intercomparisons on photon whole-body dosemeters for individual monitoring services. These intercomparisons were organised (on a biannual basis) in 2008, 2010, 2012 and 2014, each time with a similar set-up but with small alterations in the subsequent irradiation plans. With an increasing number of participants and participating systems, this intercomparison action has become an important tool for individual monitoring services to test their whole-body dosimetry systems, compare their results with other services or systems and to improve the quality of their dosimetry. The paper presents and compares the results of these four intercomparisons and compares the dosimetric results for the participating system types. Major dosimetric problems of the individual monitoring services are identified, and trends in the dosimetric performance of the different systems are shown. This gives the opportunity to identify some dosimetry issues that should be improved by application of the monitoring services' quality assurance systems and QA procedures.


Assuntos
Monitoramento de Radiação/instrumentação , Proteção Radiológica/métodos , Contagem Corporal Total/métodos , Calibragem , Europa (Continente) , Dosimetria Fotográfica/instrumentação , Dosimetria Fotográfica/métodos , Humanos , Fótons , Controle de Qualidade , Doses de Radiação , Monitoramento de Radiação/métodos , Proteção Radiológica/instrumentação , Reprodutibilidade dos Testes , Raios X
15.
Neurotox Res ; 29(1): 69-79, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26264240

RESUMO

Chronic alcohol consumption may cause neurodevelopmental and neurodegenerative disorders. Alcohol neurotoxicity is associated with the production of acetaldehyde and reactive oxygen species that induce oxidative DNA damage. However, the molecular mechanisms by which ethanol disturbs the DNA damage response (DDR), resulting in a defective DNA repair, remain unknown. Here, we have used cultured primary cortical neurons exposed to 50 or 100 mM ethanol for 7 days to analyze the ethanol-induced DDR. Ethanol exposure produced a dose-dependent generation of double strand breaks and the formation of DNA damage foci immunoreactive for the histone γH2AX, a DNA damage marker, and for the ubiquitylated H2A, which is involved in chromatin remodeling at DNA damage sites. Importantly, these DNA damage foci failed to recruit the protein 53BP1, a crucial DNA repair factor. This effect was associated with a drop in 53BP1 mRNA and protein levels and with an inhibition of global transcription. Moreover, ethanol-exposed neurons treated with ionizing radiation (2 Gy) also failed to recruit 53BP1 at DNA damage foci and exhibited a greater vulnerability to DNA lesions than irradiated control neurons. Our results support that defective DNA repair, mediated by the deficient expression and recruitment of 53BP1 to DNA damage sites, represents a novel mechanism involved in ethanol neurotoxicity. The design of therapeutic strategies that increase or stabilize 53BP1 levels might potentially promote DNA repair and partially compensate alcohol neurotoxicity.


Assuntos
Depressores do Sistema Nervoso Central/farmacologia , Córtex Cerebral/citologia , Reparo do DNA/efeitos dos fármacos , Etanol/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neurônios/efeitos dos fármacos , Animais , Cromatina/efeitos dos fármacos , Cromatina/ultraestrutura , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Hipocampo/citologia , Histonas/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/ultraestrutura , Ratos , Fatores de Tempo , Ativação Transcricional/efeitos dos fármacos , Raios X/efeitos adversos
16.
Radiat Prot Dosimetry ; 170(1-4): 82-5, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26759475

RESUMO

The European Radiation Dosimetry Group (EURADOS) has been organising dosimetry intercomparisons for many years in response to an identified requirement from individual monitoring services (IMS) for independent performance tests for dosimetry systems. The participation in intercomparisons gives IMS the opportunity to show compliance with their own quality management system, compare results with other participants and develop plans for improving their dosimetry systems. In response to growing demand, EURADOS has increased the number of intercomparisons for external radiation dosimetry. Most of these fit into the programme of self-financing intercomparisons for dosemeters routinely used by IMS. This programme is being coordinated by EURADOS working group 2 (WG2). Up to now, this programme has included four intercomparisons for whole-body dosemeters in photon fields, one for extremity dosemeters in photon and beta fields, and one for whole-body dosemeters in neutron fields. Other EURADOS working groups have organised additional intercomparisons including events in 2014 for eye-lens dosemeters and passive area dosemeters for environmental monitoring. In this paper, the organisation and achievements of these intercomparisons are compared in detail focusing on the similarities and differences in their execution.


Assuntos
Cristalino/efeitos da radiação , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Monitoramento Ambiental/métodos , Europa (Continente) , Humanos , Cooperação Internacional , Nêutrons , Exposição Ocupacional/análise , Fótons , Doses de Radiação , Dosímetros de Radiação , Contagem Corporal Total
17.
Neurotox Res ; 27(1): 43-54, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25022897

RESUMO

The specific traffic of the membrane components in neurons is a major requirement to establish and maintain neuronal domains-the axonal and the somatodendritic domains-and their polarized morphology. Unlike axons, dendrites contain membranous organelles, which are involved in the secretory pathway, including the endoplasmic reticulum, the Golgi apparatus and post-Golgi apparatus carriers, the cytoskeleton, and plasma membrane. A variety of molecules and factors are also involved in this process. Previous studies have shown that chronic alcohol exposure negatively affects several of these cell components, such as the Golgi apparatus or cytoskeleton in neurons. Yet very little information is available on the possible effects of this exposure on the remaining cell elements involved in intracellular trafficking in neurons, particularly in dendrites. By qualitative and quantitative electron microscopy, immunofluorescence and immunoblotting, we herein show that chronic exposure to moderate levels (30 mM) of ethanol in cultured neurons reduces the volume and surface density of the rough endoplasmic reticulum, and increases the levels of GRP78, a chaperone involved in endoplasmic reticulum stress. Ethanol also significantly diminishes the proportion of neurons that show an extension of Golgi into dendrites and dendritic Golgi outposts, a structure present exclusively in longer, thicker apical dendrites. Both Golgi apparatus types were also fragmented into a large number of cells. We also investigated the effect of alcohol on the levels of microtubule-based motor proteins KIF5, KIF17, KIFC2, dynein, and myosin IIb, responsible for transporting different cargoes in dendrites. Of these, alcohol differently affects several of them by lowering dynein and raising KIF5, KIFC2, and myosin IIb. These results, together with other previously published ones, suggest that practically all the protein trafficking steps in dendrites are altered to a greater or lesser extent by chronic alcohol exposure in neuronal cells, which may have negative repercussions for the development and maintenance of their polarized morphology and function.


Assuntos
Dendritos/efeitos dos fármacos , Dendritos/ultraestrutura , Etanol/farmacologia , Transporte Proteico/efeitos dos fármacos , Animais , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático Rugoso/efeitos dos fármacos , Retículo Endoplasmático Rugoso/ultraestrutura , Etanol/administração & dosagem , Feminino , Complexo de Golgi/efeitos dos fármacos , Complexo de Golgi/ultraestrutura , Proteínas de Choque Térmico/metabolismo , Proteínas Motores Moleculares/efeitos dos fármacos , Proteínas Motores Moleculares/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Ratos Wistar
18.
Neurotox Res ; 24(4): 532-48, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23820986

RESUMO

Dendritic spines are specialised membrane protrusions of neuronal dendrites that receive the majority of excitatory synaptic inputs. Abnormal changes in their density, size and morphology have been associated with various neurological and psychiatric disorders, including those deriving from drug addiction. Dendritic spine formation, morphology and synaptic functions are governed by the actin cytoskeleton. Previous in vivo studies have shown that ethanol alters the number and morphology of spines, although the mechanisms underlying these alterations remain unknown. It has also been described how chronic ethanol exposure affects the levels, assembly and cellular organisation of the actin cytoskeleton in hippocampal neurons in primary culture. Therefore, we hypothesised that the ethanol-induced alterations in the number and shape of dendritic spines are due to alterations in the mechanisms regulating actin cytoskeleton integrity. The results presented herein show that chronic exposure to moderate levels of alcohol (30 mM) during the first 2 weeks of culture reduces dendritic spine density and alters the proportion of the different morphologies of these structures in hippocampal neurons, which affects the formation of mature spines. Apparently, these effects are associated with an increase in the G-actin/F-actin ratio due to a reduction of the F-actin fraction, leading to changes in the levels of the different factors regulating the organisation of this cytoskeletal component. The data presented herein indicate that these effects occur between weeks 1 and 2 of culture, an important period in dendritic spines development. These changes may be related to the dysfunction in the memory and learning processes present in children prenatally exposed to ethanol.


Assuntos
Citoesqueleto de Actina/efeitos dos fármacos , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/ultraestrutura , Etanol/toxicidade , Acetilcolinesterase/metabolismo , Actinas/metabolismo , Animais , Células Cultivadas , Proteína 4 Homóloga a Disks-Large , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Ratos , Ratos Wistar , Receptores Ionotrópicos de Glutamato/metabolismo , Proteínas Ativadoras de ras GTPase/metabolismo
19.
Rev. argent. microbiol ; 48(3): 187-190, set. 2016. ilus
Artigo em Espanhol | LILACS | ID: biblio-1290554

RESUMO

Dentro del género Candida, la especie más frecuentemente aislada de materiales clínicos es Candida albicans. Debido a la emergencia de otras especies que pueden presentar mayor índice de resistencia a los antifúngicos, se hace necesaria la identificación rápida de aquellas. El objetivo del presente trabajo fue evaluar el rendimiento del sistema RapID™ Yeast Plus a partir de subcultivos en 2 formulaciones diferentes, agar Sabouraud dextrosa modificado por Emmons (medio indicado en el inserto del equipo) y agar Sabouraud glucosado, que es el utilizado habitualmente en los laboratorios de la Ciudad Autónoma de Buenos Aires. Se estudiaron 166 cepas de muestras clínicas provenientes de los distintos hospitales que integran la Red de Micología de la Ciudad de Buenos Aires. De los resultados obtenidos se concluye que se deben mantener las condiciones y el medio de cultivo indicado por el fabricante


Within the genus Candida, Candida albicans is the most commonly isolated species from clinical samples. Due to the emergence of other species which can show a higher index of antifungal resistance, a fast identification of these species is necessary. The aim of this work was to evaluate the performance of the RapID Yeast Plus system from two different subculture media formulations: Sabouraud dextrose agar adjusted by Emmons (the medium is indicated in the equipment insert) and Sabouraud glucose agar, which is the most frequently used in Buenos Aires City laboratories. One hundred and sixty-six clinical sample strains coming from different hospitals belonging to the Mycology Network of Buenos Aires City were studied. From the obtained results, we conclude that the conditions and culture medium indicated by the manufacturer should be followed


Assuntos
Leveduras/isolamento & purificação , Candida/classificação , Técnicas e Procedimentos Diagnósticos , Meios de Cultura/análise , Candidíase/diagnóstico , Estudo de Avaliação
20.
Toxicol Sci ; 118(2): 602-12, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20829428

RESUMO

The organization and dynamics of microtubules (MTs) and the actin cytoskeleton are critical for the correct development and functions of neurons, including intracellular traffic and signaling. In vitro ethanol exposure impairs endocytosis, exocytosis, and nucleocytoplasmic traffic in astrocytes and alters endocytosis in cultured neurons. In astrocytes, these effects relate to changes in the organization and/or function of MTs and the actin cytoskeleton. To evaluate this possibility in hippocampal cultured neurons, we analyzed if chronic ethanol exposure affects the levels, assembly, and cellular organization of both cytoskeleton elements and the possible underlying mechanisms of these effects by morphological and biochemical methods. In the experiments described below, we provide the first evidence that chronic alcohol exposure decreases the amount of both filamentous actin and polymerized tubulin in neurons and that the number of MTs in dendrites lowers in treated cells. Alcohol also diminishes the MT-associated protein-2 levels, which mainly localizes in the somatodendritic compartment in neurons. Ethanol decreases the levels of total Rac, Cdc42, and RhoA, three small guanosine triphosphatases (GTPases) involved in the organization and dynamics of the actin cytoskeleton and MTs. Yet when alcohol decreases the levels of the active forms (GTP bound) of Rac1 and Cdc42, it does not affect the active form of RhoA. We also investigated the levels of several effector and regulator molecules of these GTPases to find that alcohol induces heterogeneous results. In conclusion, our results show that MT, actin cytoskeleton organization, and Rho GTPase signaling pathways are targets for the toxic effects of ethanol in neurons.


Assuntos
Depressores do Sistema Nervoso Central/toxicidade , Citoesqueleto/efeitos dos fármacos , Etanol/toxicidade , Hipocampo/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Actinas/metabolismo , Animais , Células Cultivadas , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Feminino , Hipocampo/metabolismo , Hipocampo/patologia , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Neurônios/metabolismo , Neurônios/ultraestrutura , Ratos , Transdução de Sinais/efeitos dos fármacos , Proteínas rho de Ligação ao GTP/metabolismo
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