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1.
Mol Psychiatry ; 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39237722

RESUMEN

Chronic stress exerts profound negative effects on cognitive and emotional behaviours and is a major risk factor for the development of neuropsychiatric disorders. However, the molecular links between chronic stress and its deleterious effects on neuronal and synaptic function remain elusive. Here, using a combination of in vitro and in vivo approaches, we demonstrate that the upregulation of miR-186-5p triggered by chronic stress may be a key mediator of such changes, leading to synaptic dysfunction. Our results show that the expression levels of miR-186-5p are increased both in the prefrontal cortex (PFC) of mice exposed to chronic stress and in cortical neurons chronically exposed to dexamethasone. Additionally, viral overexpression of miR-186-5p in the PFC of naïve mice induces anxiety- and depressive-like behaviours. The upregulation of miR-186-5p through prolonged glucocorticoid receptor activation in vitro, or in a mouse model of chronic stress, differentially affects glutamatergic and GABAergic synaptic transmission, causing an imbalance in excitation/inhibition that leads to altered neuronal network activity. At glutamatergic synapses, we observed both a reduction in synaptic AMPARs and synaptic transmission, whereas GABAergic synaptic transmission was strengthened. These changes could be rescued in vitro by a miR-186-5p inhibitor. Overall, our results establish a novel molecular link between chronic glucocorticoid receptor activation, the upregulation of miR-186-5p and the synaptic changes induced by chronic stress, that may be amenable to therapeutic intervention.

2.
J Neurochem ; 163(2): 74-93, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35950924

RESUMEN

Microglia are tissue-resident macrophages responsible for the surveillance, neuronal support, and immune defense of the brain parenchyma. Recently, the role played by microglia in the formation and function of neuronal circuits has garnered substantial attention. During development, microglia have been shown to engulf neuronal precursors and participate in pruning mechanisms while, in the mature brain, they influence synaptic signaling, provide trophic support and shape synaptic plasticity. Recently, studies have unveiled different microglial characteristics associated with specific brain regions. This emerging view suggests that the maturation and function of distinct neuronal circuits may be potentially associated with the molecular identity microglia adopts across the brain. Here, we review and summarize the known role of these cells in the thalamus, hippocampus, cortex, and cerebellum. We focus on in vivo studies to highlight the characteristics of microglia that may be important in the remodeling of these neuronal circuits and in relation to neurodevelopmental and neuropsychiatric disorders.


Asunto(s)
Microglía , Plasticidad Neuronal , Encéfalo/fisiología , Hipocampo/fisiología , Microglía/fisiología , Plasticidad Neuronal/fisiología , Neuronas , Sinapsis/fisiología
3.
Int J Mol Sci ; 23(9)2022 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-35563162

RESUMEN

Glycated human serum albumin (gHSA) undergoes conformational changes and unfolding events caused by free radicals. The glycation process results in a reduced ability of albumin to act as an endogenous scavenger and transporter protein in diabetes mellitus type 2 (T2DM) patients. Astaxanthin (ASX) in native form and complexed with metal ions (Cu2+ and Zn2+) has been shown to prevent gHSA from experiencing unfolding events. Furthermore, it improves protein stability of gHSA and human serum albumin (HSA) as it is shown through molecular dynamics studies. In this study, the ASX/ASX-metal ion complexes were reacted with both HSA/gHSA and analyzed with electronic paramagnetic resonance (EPR) spectroscopy, rheology and zeta sizer (particle size and zeta potential) analysis, circular dichroism (CD) spectroscopy and UV-Vis spectrophotometer measurements, as well as molecular electrostatic potential (MEP) and molecular docking calculations. The addition of metal ions to ASX improves its ability to act as an antioxidant and both ASX or ASX-metal ion complexes maintain HSA and gHSA stability while performing their functions.


Asunto(s)
Complejos de Coordinación , Albúmina Sérica Humana , Dicroismo Circular , Humanos , Iones , Simulación del Acoplamiento Molecular , Unión Proteica , Albúmina Sérica/metabolismo , Albúmina Sérica Humana/metabolismo , Xantófilas
4.
Pediatr Phys Ther ; 34(2): 180-183, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35385449

RESUMEN

PURPOSE: Clinical experience suggests that gastroesophageal reflux disease (GERD) occurs commonly in infants with congenital muscular torticollis (CMT). However, this is an understudied topic and prospective studies are absent. We determine the prevalence of GERD in infants with CMT, comparing clinical characteristics between CMT infants with and without GERD, and identifying infants with potentially undiagnosed GERD. METHODS: A prospective cohort study of 155 infants with CMT younger than 12 months with and without GERD was evaluated by pediatric physical therapists. RESULTS: GERD prevalence was 30.3%, including 6 (3.9%) infants with undiagnosed GERD. Demographic and clinical characteristics were similar in CMT infants with and without GERD. CONCLUSIONS: This is the first prospective cohort study determining the prevalence of GERD in infants referred for evaluation of CMT. Further prospective studies are needed to determine whether early intervention and treatment of GERD improves outcomes in infants with CMT (see Supplemental Digital Content 1, available at: http://links.lww.com/PPT/A369).


Asunto(s)
Reflujo Gastroesofágico , Tortícolis , Niño , Reflujo Gastroesofágico/diagnóstico , Reflujo Gastroesofágico/epidemiología , Humanos , Lactante , Prevalencia , Estudios Prospectivos , Tortícolis/congénito
5.
Mol Divers ; 25(4): 2035-2043, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32377993

RESUMEN

HSV disease is distributed worldwide. Anti-herpesvirus drugs are a problem in clinical settings, particularly in immunocompromised individuals undergoing herpes simplex virus type 1 infection. In this work, 4-substituted-1,2,3-1H-1,2,3-triazole linked nitroxyl radical derived from TEMPOL were synthesized, and their ability to inhibit the in vitro replication of HSV-1 was evaluated. The nitroxide derivatives were characterized by infrared spectroscopy and elemental analysis, and three of them had their crystal structures determined by single-crystal X-ray diffraction. Four hybrid molecules showed important anti-HSV-1 activity with IC50 values ranged from 0.80 to 1.32 µM. In particular, one of the nitroxide derivatives was more active than Acyclovir (IC50 = 0.99 µM). All compounds tested were more selective inhibitors than the reference antiviral drug. Among them, two compounds were 4.5 (IC50 0.80 µM; selectivity index CC50/IC50 3886) and 7.7 times (IC50 1.10 µM; selectivity index CC50/IC50 6698) more selective than acyclovir (IC50 0.99 µM; selectivity index CC50/IC50: 869). These nitroxide derivatives may be elected as leading compounds due to their antiherpetic activities and good selectivity.


Asunto(s)
Herpesvirus Humano 1
6.
Int J Mol Sci ; 22(4)2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33572316

RESUMEN

Pyomelanin mimics from homogentisic acid (HGA) and gentisic acid (GA) were biosynthesized by the oxidative enzyme T. versicolor laccase at physiological pH to obtain water soluble melanins. The pigments show brown-black color, broad band visible light absorption, a persistent paramagnetism and high antioxidant activity. The EPR approach shows that at least two different radical species are present in both cases, contributing to the paramagnetism of the samples. This achievement can also shed light on the composition of the ochronotic pigment in the Alkaptonuria disease. On the other hand, these soluble pyomelanin mimics, sharing physico-chemical properties with eumelanin, can represent a suitable alternative to replace the insoluble melanin pigment in biotechnological applications.


Asunto(s)
Antioxidantes/farmacología , Gentisatos/farmacología , Ácido Homogentísico/farmacología , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Antioxidantes/metabolismo , Biotecnología/métodos , Proteínas Fúngicas/metabolismo , Gentisatos/química , Gentisatos/aislamiento & purificación , Gentisatos/metabolismo , Ácido Homogentísico/química , Ácido Homogentísico/aislamiento & purificación , Ácido Homogentísico/metabolismo , Lacasa/metabolismo , Melaninas/química , Polyporaceae/enzimología
7.
J Environ Manage ; 286: 112189, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33677342

RESUMEN

Fire is one of the most powerful modifiers of the Amazonian landscape and knowledge about its drivers is needed for planning control and suppression. A plethora of factors may play a role in the annual dynamics of fire frequency, spanning the biophysical, climatic, socioeconomic and institutional dimensions. To uncover the main forces currently at play, we investigated the area burned in both forested and deforested areas in the outstanding case of Brazil's state of Acre, in southwestern Amazonia. We mapped burn scars in already-deforested areas and intact forest based on satellite images from the Landsat series analyzed between 2016 and 2019. The mapped burnings in already-deforested areas totalled 550,251 ha. In addition, we mapped three forest fires totaling 34,084 ha. Fire and deforestation were highly correlated, and the latter occurred mainly in federal government lands, with protected areas showing unprecedented forest fire levels in 2019. These results indicate that Acre state is under increased fire risk even during average rainfall years. The record fires of 2019 may continue if Brazil's ongoing softening of environmental regulations and enforcement is maintained. Acre and other Amazonian states must act quickly to avoid an upsurge of social and economic losses in the coming years.


Asunto(s)
Incendios , Incendios Forestales , Brasil , Conservación de los Recursos Naturales , Bosques , Árboles
8.
J Sci Food Agric ; 101(10): 4409-4419, 2021 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-33421137

RESUMEN

BACKGROUND: Fermented cocoa beans (Theobroma cacao L.) are a pivotal raw material for chocolate production. A cocktail yeast applied in the cocoa fermentation process can promote the formation of pleasant metabolites. Saccharomyces, Pichia and Hanseniaspora have been widely used in fermentation to improve the final product organoleptic profile, highlighting that fermentation is a critical point for chocolate flavour precursor production. This study aims to evaluate the impact of Pichia kluyveri and Saccharomyces cerevisiae strains as starter cultures on the fermentation for two cocoa hybrids, FA13 and CEPEC2002. RESULTS: During fermentation processes, volatile organic compounds (VOCs) and protein profiles were assessed. Chocolates produced were also assessed regarding the presence of VOCs. Eighty VOCs were identified using gas chromatography coupled to mass spectrometry analysis. Mass spectrometry provided the protein profile evolution during fermentation and showed that the profiles changed with inoculation type (spontaneous versus inoculated fermentation). Chocolate obtained from FA13 inoculated with S. cerevisiae strain contained a greater amount of organics acids, being categorised as sourer than chocolate produced by spontaneous fermentation of FA13. CEPEC2002 inoculated with S. cerevisiae strain in co-culture with P. kluyveri strain generated less sour and sweeter chocolate than spontaneous fermentation only. CONCLUSIONS: Chocolates from inoculated assays with starter cultures were more accepted by evaluators, highlighting that P. kluyveri and S. cerevisiae influence the composition of VOCs. Besides, protein profiles also changed throughout fermentation. Further investigation should be conducted to clarify protein degradation dynamics during inoculated fermentations to define which of the microbial cultures positively affect the chocolate sensory characteristics. © 2021 Society of Chemical Industry.


Asunto(s)
Cacao/microbiología , Pichia/metabolismo , Saccharomyces cerevisiae/metabolismo , Cacao/química , Cacao/metabolismo , Chocolate/análisis , Chocolate/microbiología , Fermentación , Aromatizantes/química , Aromatizantes/metabolismo , Microbiología de Alimentos , Cromatografía de Gases y Espectrometría de Masas , Humanos , Semillas/química , Semillas/metabolismo , Semillas/microbiología , Gusto , Compuestos Orgánicos Volátiles/química , Compuestos Orgánicos Volátiles/metabolismo
9.
BMC Pediatr ; 20(1): 371, 2020 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-32767992

RESUMEN

BACKGROUND: The oropharyngeal colostrum administration protocol to treat premature newborns is a possible and plausible strategy in neonatal health services, since the immunoprotective components of colostrum can be absorbed by the lymphoid tissues of the oropharynx. In this context, this study aims to describe the implementation of oropharyngeal colostrum immunotherapy in very low birth weight preterm newborns in a neonatal unit, as well as to test an algorithm in a public hospital. METHODS: The protocol is applied in a non-randomized, superiority clinical trial with historical control. In the treatment group, 0.2 mL of raw colostrum is dripped into the right and left oropharyngeal mucosa, totaling 8 administrations every 24 h until the 7th complete day of life interruptedly. The control group consists of very low birth weight preterm newborns born in the same hospital in previous years (historical control). The clinical progression of 60 newborns until hospital discharge is recorded on standardized forms. A total of 350 participants are estimated to complete the survey in 4 years. The occurrence of continuous outcomes between the groups are compared through the paired t-test or Wilcoxon's two-sample test. The chi-square test or Fisher's exact test, and survival analysis are used for binary outcomes. The nutritional status is assessed through Intergrowth-21st growth curves for preterm newborns. DISCUSSION: The flows of the protocol's actions is sorted by an algorithm, compatible with the Brazilian reality of a public hospital. This measure facilitates and systematizes clinical care, organizes the team's work process, speeds up the intervention steps, standardizes decision-making and unifies the quality of care, besides showing the feasibility of oropharyngeal colostrum immunotherapy. TRIAL REGISTRATION: ReBEC, U1111-1222-0598 , Registered 09 October 2018, http://www.ensaiosclinicos.gov.br/rg/RBR-2cyp7c/ .


Asunto(s)
Calostro , Recien Nacido Prematuro , Peso al Nacer , Femenino , Humanos , Inmunoterapia , Lactante , Recién Nacido , Recién Nacido de muy Bajo Peso , Orofaringe , Embarazo
10.
Molecules ; 23(8)2018 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-30071605

RESUMEN

An actinobacteria strain was isolated from Algerian Sahara soil and assigned to Streptomyces cyaneofuscatus Pridham et al. 1958 species. This strain was selected for its ability to produce melanin exopigments in liquid and solid media. Melanin synthesis was associated with tyrosinase activity and the enzyme from this strain was isolated and biochemically characterized. Synthetic melanin was then enzymatically produced using the S. cyaneofuscatus Pridham et al. 1958 tyrosinase. As this enzyme showed a higher diphenolase activity, a synthetic melanin from the enzymic oxidation of 3,4-dihydroxyphenylalanine (dopa) was obtained by the use of a Trametes versicolor (L.) Lloyd laccase for comparison. The natural and synthetic pigments were physico-chemically characterized by the use of ultraviolet (UV)-Visible, and Fourier transform infrared (FT-IR) and multifrequency electron paramagnetic resonance (EPR) spectroscopies. All the melanin samples displayed a stable free radical when analyzed by X-band EPR spectroscopy. Once the samples were recorded at Q-band EPR, a copolymer derived from a mixture of different constituents was evident in the natural melanin. All radical species were analyzed and discussed. The use of water-soluble melanin naturally produced by S. cyaneofuscatus Pridham et al. 1958 represents a new biotechnological alternative to commercial insoluble pigments.


Asunto(s)
Lacasa/metabolismo , Melaninas/metabolismo , Monofenol Monooxigenasa/metabolismo , Streptomyces/metabolismo , Espectroscopía de Resonancia por Spin del Electrón , Espectroscopía Infrarroja por Transformada de Fourier
11.
Int J Mol Sci ; 18(9)2017 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-28880250

RESUMEN

The insulin/insulin-like growth factor (IGF) system in mammals comprises a dynamic network of proteins that modulate several biological processes such as development, cell growth, metabolism, and aging. Dysregulation of the insulin/IGF system has major implications for several pathological conditions such as diabetes and cancer. Metabolic changes also culminate in aberrant glycosylation, which has been highlighted as a hallmark of cancer. Changes in glycosylation regulate every pathophysiological step of cancer progression including tumour cell-cell dissociation, cell migration, cell signaling and metastasis. This review discusses how the insulin/IGF system integrates with glycosylation alterations and impacts on cell behaviour, metabolism and drug resistance in cancer.


Asunto(s)
Factor I del Crecimiento Similar a la Insulina/metabolismo , Insulina/metabolismo , Neoplasias/metabolismo , Polisacáridos/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos/genética , Animales , Glicosilación , Humanos , Insulina/genética , Factor I del Crecimiento Similar a la Insulina/genética , Neoplasias/genética , Neoplasias/patología , Transducción de Señal/genética , Transducción de Señal/fisiología
12.
Rev Esc Enferm USP ; 51: e03231, 2017 Jun 12.
Artículo en Inglés, Portugués, Español | MEDLINE | ID: mdl-28614438

RESUMEN

OBJECTIVE: To assess the direct cost of dressings in pressure ulcer treatment. METHOD: This was a descriptive observational study conducted at an intensive care unit in the Northeast region of Brazil, between November and December 2015. Data were gathered using the Pressure Ulcer Scale for Healing and a form to characterize and assess costs. Values in Brazilian reais (BRL) were converted into U.S. dollars at the exchange rate of USD 0.26/BRL. Univariate and bivariate analyses were conducted. RESULTS: The sample consisted of 15 patients with at least stage 2 ulcers. There was a significant reduction in costs with dressing materials between the initial and final assessments (p=0.002), with a mean of USD 11.9 (±7.4). The most common topical treatments used were essential fatty acids and papain. CONCLUSION: Cost reduction was proportional to the stage of pressure ulcer. The role of nurses in creating evidence-based care plans is crucial to improve care management. OBJETIVO: Avaliar o custo direto com curativos no tratamento de lesões por pressão. MÉTODO: Estudo observacional descritivo, realizado em Unidade de Terapia Intensiva do nordeste do Brasil, de novembro a dezembro de 2015. Foi aplicada a Pressure Ulcer Scale for Healing e formulário para caracterização e avaliação de custos. Os valores da moeda brasileira (R$) foram convertidos para a moeda norte-americana (US$) à taxa de US$0,26/R$. Foram realizadas análises univariadas e bivariadas. RESULTADOS: Compuseram a amostra 15 pacientes com lesões, no mínimo, estágio 2. Houve redução significativa dos custos com materiais de curativos entre as avaliações inicial e final (p=0,002), com média de US$11,9 (±7,4). As terapias tópicas mais frequentes foram ácidos graxos essenciais e papaína. CONCLUSÃO: Verificou-se redução de custos proporcional aos estágios das lesões. Enfatiza-se o papel do enfermeiro na elaboração de planos de cuidados baseados em evidências para melhor gerenciamento do cuidado. OBJETIVO: Evaluar el costo directo de curativos para el tratamiento de lesiones por presión. MÉTODO: Estudio observacional descriptivo en la Unidad de Cuidados Intensivos del noreste de Brasil, de noviembre a diciembre del año 2015. Se aplicó la Pressure Ulcer Scale for Healing y formulario para la caracterización y evaluación de los costos. Los valores de la moneda brasileña (Reales- R$) se convirtieron al dólar estadounidense (US$) a razón de $0.26/R$. Se realizaron análisis univariados y bivariados. RESULTADOS: La muestra consistió en 15 pacientes con lesiones al menos en Etapa 2. Hubo una reducción significativa en el costo de los materiales de curación entre las evaluaciones inicial y final (p=0,002), con un promedio de US$11.9 (±7.4). Los tratamientos tópicos más comunes son los ácidos grasos esenciales y papaína. CONCLUSIÓN: Se verificó una reducción de los costos proporcional a las etapas de las lesiones. Se hace hincapié en el papel de los enfermeros en el desarrollo de planes de cuidados basados en la evidencia, para una mejor gestión de la atención.


Asunto(s)
Vendajes/economía , Costos y Análisis de Costo , Úlcera por Presión/enfermería , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crítica , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Adulto Joven
13.
Cell Microbiol ; 16(8): 1244-54, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24612488

RESUMEN

ExoU is an important virulence factor in acute Pseudomonas aeruginosa infections. Here, we unveiled the mechanisms of ExoU-driven NF-κB activation by using human airway cells and mice infected with P. aeruginosa strains. Several approaches showed that PAFR was crucially implicated in the activation of the canonical NF-κB pathway. Confocal microscopy of lungs from infected mice revealed that PAFR-dependent NF-κB activation occurred mainly in respiratory epithelial cells, and reduced p65 nuclear translocation was detected in mice PAFR-/- or treated with the PAFR antagonist WEB 2086. Several evidences showed that ExoU-induced NF-κB activation regulated PAFR expression. First, ExoU increased p65 occupation of PAFR promoter, as assessed by ChIP. Second, luciferase assays in cultures transfected with different plasmid constructs revealed that ExoU promoted p65 binding to the three κB sites in PAFR promoter. Third, treatment of cell cultures with the NF-κB inhibitor Bay 11-7082, or transfection with IκBα negative-dominant, significantly decreased PAFR mRNA. Finally, reduction in PAFR expression was observed in mice treated with Bay 11-7082 or WEB 2086 prior to infection. Together, our data demonstrate that ExoU activates NF-κB by PAFR signalling, which in turns enhances PAFR expression, highlighting an important mechanism of amplification of response to this P. aeruginosa toxin.


Asunto(s)
Proteínas Bacterianas/metabolismo , Factor de Activación Plaquetaria/metabolismo , Glicoproteínas de Membrana Plaquetaria/genética , Pseudomonas aeruginosa/patogenicidad , Receptores Acoplados a Proteínas G/genética , Factor de Transcripción ReIA/metabolismo , Animales , Azepinas/farmacología , Toxinas Bacterianas/metabolismo , Línea Celular , Activación Enzimática , Femenino , Regulación de la Expresión Génica , Humanos , Pulmón/microbiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Confocal , Factor de Activación Plaquetaria/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Glicoproteínas de Membrana Plaquetaria/antagonistas & inhibidores , Glicoproteínas de Membrana Plaquetaria/biosíntesis , Regiones Promotoras Genéticas , Unión Proteica , Infecciones por Pseudomonas/patología , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/biosíntesis , Transducción de Señal/genética , Triazoles/farmacología
14.
Avian Dis ; 59(1): 79-86, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26292539

RESUMEN

Infectious diseases such as aspergillosis, avian malaria, and viral infections are significant threats to the conservation of penguins, leading to morbidity and mortality of these birds both in captivity and in the wild. The immune response to such infectious diseases is dependent on different mechanisms mediated by cells and soluble components such as antibodies. Antibodies or immunoglobulins are glycoproteins that have many structural and functional features that mediate distinct effector immune functions. Three distinct classes of antibodies have been identified in birds: immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin Y (IgY). In this study we aim to establish an efficient laboratory method to obtain IgM and IgY antibodies from plasma samples of healthy adult Magellanic penguins (Spheniscus magellanicus). The protocol was developed combining plasma delipidation, sequential precipitation with caprylic acid and ammonium sulfate, and size-exclusion chromatography. The efficiency of the protocol and the identity of the purified IgM and IgY antibodies were confirmed through enzyme-linked immunosorbent assay, Western blotting, one-dimensional and two-dimensional polyacrylamide gel electrophoresis, and lectin binding assay. Structural and physicochemical properties of IgM and IgY from Magellanic penguins were consistent with those of other avian species. This purification protocol will allow for more detailed studies on the humoral immunity of penguins and for the development of high specificity serologic assays to test Magellanic penguins for infectious pathogens.


Asunto(s)
Inmunoglobulina M/sangre , Inmunoglobulinas/sangre , Spheniscidae/sangre , Animales
15.
Polymers (Basel) ; 16(13)2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-39000661

RESUMEN

The escalating environmental concerns associated with petroleum-based adhesives have spurred an urgent need for sustainable alternatives. Chitosan, a natural polysaccharide, is a promising candidate; however, its limited water resistance hinders broader application. The aim of this study is to develop a new chitosan-based adhesive with improved properties. The polydopamine association with chitosan presents a significant increase in adhesiveness compared to pure chitosan. Polydopamine is synthesized by the enzymatic action of laccase from Trametes versicolor at pH = 4.5, in the absence or presence of chitosan. This pH facilitates chitosan's solubility and the occurrence of catechol in its reduced form (pH < 5.5), thereby increasing the final adhesive properties. To further enhance the adhesive properties, various crosslinking agents were tested. A multi-technique approach was used for the characterization of formulations. The formulation based on 3% chitosan, 50% polydopamine, and 3% xanthan gum showed a spectacular increase in adhesive properties when tested on glass, cardboard and textile. This formulation increased water resistance, maintaining the adhesion of a sample soaked in water for up to 10 h. For cardboard and textile, material rapture occurred, in mechanical tests, prior to adhesive bond failure. Furthermore, all the samples showed antiflame properties, expanding the benefits of their use. Comparison with commercial glues confirms the remarkable adhesive properties of the new formulation.

16.
Cien Saude Colet ; 29(3): e11782023, 2024 Mar.
Artículo en Portugués, Inglés | MEDLINE | ID: mdl-38451654

RESUMEN

This is a study on sickle cell disease, a chronic illness that affects many Brazilians, that aims to understand and analyze how people address the adversities arising from the diagnosis and the biographical rupture. The description of people's experiences and strategies conjures a picture that expresses the respondents' habitus, built in a dialectical relationship with the vulnerability determined by the disease. We adopted a qualitative approach and focused interviews as proposed by Merton, combined with the snowball technique, applied to groups related to sickle cell disease on social networks. Seven participants were selected because they were privileged informants with the disease, were over eighteen, lived in the Federal District, and were non-exclusive users of the Unified Health System. The interview material was categorized from the focal groups employed. The results indicated the following categories: biographical rupture, experience and coping strategies, and healthcare. It is necessary to sensitize professionals and the population about the challenging living conditions of people with sickle cell disease and the consolidation of public policies and care networks to accommodate this population.


Trata-se de um estudo sobre a doença falciforme, enfermidade crônica que afeta muitas pessoas no Brasil. O objetivo foi compreender como as pessoas lidam com as adversidades oriundas do diagnóstico e a ruptura biográfica. A descrição das experiências e estratégias empregadas pelas pessoas compuseram um quadro que expressa os habitus dos entrevistados, construídos em relação dialética com a vulnerabilidade determinada pela doença. A abordagem foi qualitativa e empregou entrevistas focadas como propostas por Merton, a técnica bola de neve aplicada em grupos relacionados à doença falciforme em redes sociais. Sete participantes foram selecionados por serem informantes privilegiados, portadores da doença, maiores de 18 anos, moradores no Distrito Federal e usuários não exclusivos do Sistema Único de Saúde. O material das entrevistas foi categorizado a partir dos núcleos focais empregados. Os resultados apontaram as categorias: ruptura biográfica, experiência e estratégias de enfrentamento, atenção à saúde. Concluímos que é necessária uma sensibilização dos profissionais e da população sobre as dificuldades da condição de vida das pessoas com doença falciforme e a consolidação das políticas públicas e das redes de atendimento para acolher essa população.


Asunto(s)
Anemia de Células Falciformes , Pueblos Sudamericanos , Humanos , Anemia de Células Falciformes/epidemiología , Brasil , Habilidades de Afrontamiento , Grupos Focales
17.
Sci Total Environ ; 950: 175302, 2024 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-39111422

RESUMEN

Sandy beach ecosystems are particularly affected by plastic pollution. Supralittoral amphipods are important components of the food web in sandy beaches and their ability to ingest microplastics and bioplastics has been assessed. Chitosan, a polysaccharide obtained by deacetylation of chitin, the second most abundant polymer in the world, represents an interesting component to produce novel bioplastics in combination with other biopolymers like starch. Here, the possibility of ingesting chitosan-starch blends and the possible effects on the amphipod Talitrus saltator were investigated. Groups of adult individuals were fed with sheets containing mixtures of chitosan and starch in different percentages for 7 and 14 days. The results showed that chitosan ingestion is dependent on the percentage of starch present in the mixture. Moreover, FTIR analyses of both sheets and faecal pellets after consumption show that chitosan is not digested. Furthermore, the survival rate of amphipods fed with a mixture of chitosan and starch decreases after one week compared to the control groups (100 % starch and paper), and drops drastically to 0 % after two weeks the experiment began. In addition, consumption of 100 % chitosan is negligible. Therefore, the results of the experimental observations evidenced that chitosan is avoided as food resource and its consumption significantly affects the survival capacity of T. saltator. It is emphasized that the release of mixtures of chitosan and starch into the marine environment appears to be dangerous for littoral amphipods.


Asunto(s)
Anfípodos , Quitosano , Almidón , Contaminantes Químicos del Agua , Animales , Anfípodos/fisiología , Anfípodos/efectos de los fármacos , Microplásticos , Cadena Alimentaria
18.
Int J Biol Macromol ; 277(Pt 1): 133828, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39084985

RESUMEN

This study aimed to perform a bibliometric analysis of starch films with nanocellulose, using the Scopus database and VOSviewer and Bibliometrix software. A total of 258 documents were identified between 2019 and 2023, reflecting a growing interest in research, particularly in journals such as the International Journal of Biological Macromolecules, Polymers, and Carbohydrate Polymers. The most common terms were "starch" (349 occurrences), "cellulose" (207), and "tensile strength" (175). China (58 articles), Brazil (38), and India (33) led scientific production, with authors like Ilyas (13 articles) and Sapuan (10) at the forefront. Approximately 41.7 % of the studies used corn starch. The analysis revealed that 66 % of the studies investigated films with cellulose nanofibrils (CNF), 32 % with cellulose nanocrystals (CNC), and 2 % with bacterial nanocellulose (CB). The majority of studies (94.1 %) used the casting method for film production. Additionally, 35.44 % focused on reinforcing films with nanocellulose, while 7 % developed blends with other biopolymers. About 59.44 % examined the performance of starch films for food packaging, 11.25 % explored practical applications in various foods. Furthermore, 7.94 % incorporated active agents to improve antioxidant and antimicrobial properties, 1.30 % investigated active packaging. Moreover, 2.36 % explored the use of films in materials engineering, and 2.36 % explored biomedical potential. Only 0.40 % evaluated the impact of films on wastewater treatment. The analysis highlights the potential of starch films with nanocellulose, demonstrating their diverse applications and the growing interest in the field.


Asunto(s)
Bibliometría , Celulosa , Almidón , Almidón/química , Celulosa/química , Embalaje de Alimentos/métodos , Nanopartículas/química , Resistencia a la Tracción , Nanofibras/química
19.
Acta Trop ; 257: 107309, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38955321

RESUMEN

Bats are the second most diverse order of mammals and play a central role in ecosystem dynamics. They are also important reservoirs of potentially zoonotic microorganisms, of which rabies virus is the most lethal among the bat-transmitted zoonotic pathogens. Importantly, recent outbreaks of human rabies have been reported from the Brazilian Amazon. Here we present a survey of bat species and rabies virus (RABV) circulation in a bat assemblage in the Marajó region, northern Brazil. Using data from mist-net captures and bioacoustic sampling, 56 bat species were recorded along the Jacundá River basin over a 10-day expedition in November 2022. For the investigation of RABV, we used the direct fluorescent antibody test (DFAT) and the rapid fluorescent focus inhibition test (RFFIT). In total, 159 bat individuals from 22 species were investigated for RABV. Five adults of the common vampire bat, Desmodus rotundus, showed RABV-specific antibodies in serum samples. Additionally, we report on local residents with injuries caused by D. rotundus bites and the occurrence of colonies of non-hematophagous bats from different species roosting inside human residences. This scenario raises concerns about the risks of new cases of human rabies and other zoonotic diseases associated with bats in the region and highlights the need for epidemiological surveillance and mitigation measures to prevent outbreaks of emerging infectious diseases.


Asunto(s)
Anticuerpos Antivirales , Quirópteros , Brotes de Enfermedades , Virus de la Rabia , Rabia , Zoonosis , Quirópteros/virología , Animales , Brasil/epidemiología , Virus de la Rabia/inmunología , Virus de la Rabia/aislamiento & purificación , Virus de la Rabia/clasificación , Rabia/epidemiología , Rabia/veterinaria , Rabia/virología , Humanos , Zoonosis/epidemiología , Zoonosis/virología , Anticuerpos Antivirales/sangre , Femenino , Masculino , Adulto , Persona de Mediana Edad , Adolescente
20.
Biochim Biophys Acta ; 1822(8): 1198-206, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22542512

RESUMEN

UNLABELLED: Viruses such as HIV, HCV, Mayaro and HCMV affect cellular metabolic pathways, including glycolysis. Although some studies have suggested that the inhibition of glycolysis affects HSV-1 replication and that HSV-1-infected eyes have increased lactate production, the mechanisms by which HSV-1 induces glycolysis have never been investigated in detail. In this study, we observed an increase in glucose uptake, lactate efflux and ATP content in HSV-1-infected cells. HSV-1 triggered a MOI-dependent increase in the activity of phosphofructokinase-1 (PFK-1), a key rate-limiting enzyme of the glycolytic pathway. After HSV-1 infection, we observed increased PFK-1 expression, which increased PFK-1 total activity, and the phosphorylation of this enzyme at serine residues. HSV-1-induced glycolysis was associated with increased ATP content, and these events were critical for viral replication. In summary, our results suggest that HSV-1 triggers glycolysis through a different mechanism than other herpesviruses, such as HCMV. Thus, this study contributes to a better understanding of HSV-1 pathogenesis and provides insights into novel targets for antiviral therapy. HIGHLIGHTS: ►HSV-1 activates glycolysis by PFK-1 activation. ►In HSV-1-infected cells PFK-1 synthesis is up-regulated and phosphorylated at serine residues. ►PFK-1 knockdown impairs HSV-1 replication. ►HSV-1-mediated glycolysis activation increases ATP content.


Asunto(s)
Glucosa/metabolismo , Herpesvirus Humano 1/metabolismo , Fosfofructoquinasa-1/metabolismo , Animales , Supervivencia Celular , Chlorocebus aethiops , Activación Enzimática , Glucólisis , Herpes Simple/metabolismo , Fosfofructoquinasa-1/antagonistas & inhibidores , Fosfofructoquinasa-1/química , Células Vero
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