Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Soft Matter ; 19(9): 1720-1731, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36779517

RESUMO

The assembly of biopolymers into a hydrated elastic network often goes along with syneresis, a spontaneous process during which the hydrogel slowly shrinks and releases solvent. The tendency to syneresis of calcium-alginate hydrogels, widely used biocompatible materials, is a hindrance to applications for which dimensional integrity is crucial. Although calcium-induced aggregation of specific block-sequences has been long known as the microscopic process at work in both primary cross-linking and syneresis, the nature of the coupling between these structural events and the global deswelling flow has remained so far elusive. We have tackled this issue within the regime of entangled pregels that yield highly cross-linked, self-crowded hydrogels with stiff networks. Using an original, stopped-flow extrusion experiment, we have unveiled a robust, stretched-exponential kinetics of shrinking, spanning more than six decades of time and quasi-independent of the alginate concentration. A careful analysis of the puzzling dynamical features of syneresis in these gels has led us to propose that due to the network rigidity, the calcium-fueled, random collapse events that drive solvent locally, are not thermally activated but rather controlled by the average poroelastic flow itself, according to a self-sustained mechanism described here for the first time.

2.
Sensors (Basel) ; 23(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36772621

RESUMO

Peripheral arterial disease (PAD) causes blockage of the arteries, altering the blood flow to the lower limbs. This blockage can cause the individual with PAD to feel severe pain in the lower limbs. The main contribution of this research is the discovery of a solution that allows the automatic detection of the onset of claudication based on data analysis from patients' smartphones. For the data-collection procedure, 40 patients were asked to walk with a smartphone on a thirty-meter path, back and forth, for six minutes. Each patient conducted the test twice on two different days. Several machine learning models were compared to detect the onset of claudication on two different datasets. The results suggest that we can identify the onset of claudication using inertial sensors with a best case accuracy of 92.25% for the Extreme Gradient Boosting model.


Assuntos
Claudicação Intermitente , Doença Arterial Periférica , Humanos , Claudicação Intermitente/diagnóstico , Claudicação Intermitente/etiologia , Smartphone , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/complicações , Caminhada/fisiologia , Aprendizado de Máquina
3.
Int J Mol Sci ; 23(4)2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35216147

RESUMO

Major depressive disorder (MDD), also called depression, is a serious disease that impairs the quality of life of patients and has a high incidence, affecting approximately 3.8% of the world population. Its diagnosis is very subjective and is not supported by measurable biomarkers mainly due to the lack of biochemical markers. Recently, disturbance of lipid profiling has been recognized in MDD, in animal models of MDD or in depressed patients, which may contribute to unravel the etiology of the disease and find putative new biomarkers, for a diagnosis or for monitoring the disease and therapeutics outcomes. In this review, we provide an overview of current knowledge of lipidomics analysis, both in animal models of MDD (at the brain and plasma level) and in humans (in plasma and serum). Furthermore, studies of lipidomics analyses after antidepressant treatment in rodents (in brain, plasma, and serum), in primates (in the brain) and in humans (in plasma) were reviewed and give evidence that antidepressants seem to counteract the modification seen in lipids in MDD, giving some evidence that certain altered lipid profiles could be useful MDD biomarkers for future precision medicine.


Assuntos
Depressão/metabolismo , Metabolismo dos Lipídeos , Animais , Biomarcadores/metabolismo , Depressão/diagnóstico , Depressão/tratamento farmacológico , Humanos , Estresse Oxidativo
4.
Int J Mol Sci ; 23(21)2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36361581

RESUMO

The increase in the demand for Paracentrotus lividus roe, a food delicacy, causes increased pressure on its wild stocks. In this scenario, aquaculture facilities will mitigate the effects of anthropogenic pressures on the wild stocks of P. lividus. Consequently, experimental studies should be conducted to enhance techniques to improve efficient aquaculture practices for these animals. Here, we for the first time performed molecular investigations on cultured sea urchins. We aimed at understanding if maternal influences may significantly impact the life of future offspring, and how the culture conditions may impact the development and growth of cultured specimens. Our findings demonstrate that the outcomes of in vitro fertilization of P. lividus are influenced by maternal influences, but these effects are largely determined by culture conditions. In fact, twenty-three genes involved in the response to stress and skeletogenesis, whose expressions were measured by Real Time qPCR, were differently expressed in sea urchins cultured in two experimental conditions, and the results were largely modified in offspring deriving from two groups of females. The findings herein reported will be critical to develop protocols for the larval culture of the most common sea urchin, both for research and industrial production purposes for mass production.


Assuntos
Paracentrotus , Animais , Feminino , Paracentrotus/genética , Taxa de Sobrevida , Reprodução/genética , Larva , Expressão Gênica
5.
Brain ; 141(9): 2772-2794, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30059965

RESUMO

Autism spectrum disorders are neurodevelopmental conditions with diverse aetiologies, all characterized by common core symptoms such as impaired social skills and communication, as well as repetitive behaviour. Cell adhesion molecules, receptor tyrosine kinases and associated downstream signalling have been strongly implicated in both neurodevelopment and autism spectrum disorders. We found that downregulation of the cell adhesion molecule NEGR1 or the receptor tyrosine kinase fibroblast growth factor receptor 2 (FGFR2) similarly affects neuronal migration and spine density during mouse cortical development in vivo and results in impaired core behaviours related to autism spectrum disorders. Mechanistically, NEGR1 physically interacts with FGFR2 and modulates FGFR2-dependent extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) signalling by decreasing FGFR2 degradation from the plasma membrane. Accordingly, FGFR2 overexpression rescues all defects due to Negr1 knockdown in vivo. Negr1 knockout mice present phenotypes similar to Negr1-downregulated animals. These data indicate that NEGR1 and FGFR2 cooperatively regulate cortical development and suggest a role for defective NEGR1-FGFR2 complex and convergent downstream ERK and AKT signalling in autism spectrum disorders.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Moléculas de Adesão Celular Neuronais/fisiologia , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/fisiologia , Animais , Transtorno do Espectro Autista/metabolismo , Comportamento Animal/fisiologia , Moléculas de Adesão Celular Neuronais/metabolismo , Membrana Celular/metabolismo , Movimento Celular , Córtex Cerebral/crescimento & desenvolvimento , Espinhas Dendríticas/fisiologia , Modelos Animais de Doenças , Regulação para Baixo , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurogênese , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais/fisiologia
6.
Adv Exp Med Biol ; 1127: 67-82, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31140172

RESUMO

The liver plays a capital role in the control of whole body energy homeostasis through the metabolization of dietary carbohydrates and lipids. However, under excess macronutrient uptake, those pathways overcharge nucleus-to-endoplasmic reticulum (ER) traffic pathways, leading to luminal overload of unfolded proteins which activates a series of adaptive signaling pathways known as unfolded protein response (UPR). The UPR is a central network mechanism for cellular stress adaptation, however far from a global nonspecific all-or-nothing response. Such a complex signaling network is able to display considerable specificity of responses, with activation of specific signaling branches trimmed for distinct types of stimuli. This makes the UPR a fundamental mechanism underlying metabolic processes and diseases, especially those related to lipid and carbohydrate metabolism. Thus, for a better understanding of the role of UPR on the physiopathology of lipid metabolism disorders, the concepts discussed along this chapter will demonstrate how several metabolic derangements activate UPR components and, in turn, how UPR triggers several metabolic adaptations through its component signaling proteins. This dual role of UPR on lipid metabolism will certainly foment the pursuit of an answer for the question: is UPR cause or consequence of lipid and lipoprotein metabolism disturbances?


Assuntos
Retículo Endoplasmático/metabolismo , Metabolismo dos Lipídeos , Lipoproteínas/metabolismo , Transdução de Sinais , Resposta a Proteínas não Dobradas
7.
Clin Nephrol ; 89(2): 113-119, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29092738

RESUMO

As erythropoiesis is a continuous process, we hypothesized that a new approach with smaller doses of darbepoetin-α administered more regularly could result in fewer variations of its serum levels and be more effective. In a prevalent hemodialysis population, we evaluated the effects of the darbepoetin splitting in "mini-doses". A 34-month prospective study was performed in a cohort of 110 patients, with a mean age of 66.6 ± 14.2 years, median dialysis vintage of 63.6 months (IQ range: 27 - 86), 46.4% (n = 51) male gender, 36.4% (n = 40) diabetics. In the first 12 months of the study, the usual dose regime for darbepoetin (weekly, every other week, or monthly) was unchanged. In the following 22 months, darbepoetin doses were divided into multiples of 10 µg and administered in the maximum possible number of hemodialysis (HD) sessions. Paired Student's t or Wilcoxon matched-pairs analyses were performed. After darbepoetin splitting, we verified a decrease in its consumption (1.9 ± 1.7 to 1.4 ± 1.6 µg/kg, p < 0.0001) and in the erythropoietin resistance index (8.6 to 6.7 IU/kg/week, p = 0.0001), with stable hemoglobin levels (11.4 ± 0.7 to 11.3 ± 0.6 g/dL, p = 0.02). We also observed an increase in ferritin levels (490 ± 138.2 to 560.7 ± 149.3 µg/L, p < 0.0001) and C-reactive protein (CRP) levels, with no changes in iron doses (2.2 - 3.2 mg/kg, p = 0.24). From these results, we conclude that the splitting of darbepoetin in "mini-doses" is highly effective, potentially allowing a significant decrease in the costs of anemia treatment. Larger and randomized studies are needed to prove the cost-benefit of this new strategy.
.


Assuntos
Anemia/prevenção & controle , Darbepoetina alfa/administração & dosagem , Hematínicos/administração & dosagem , Falência Renal Crônica/terapia , Diálise Renal , Adulto , Idoso , Idoso de 80 Anos ou mais , Esquema de Medicação , Eritropoese , Feminino , Humanos , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
8.
Neural Plast ; 2018: 3725087, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30123245

RESUMO

Decline in declarative learning and memory performance is a typical feature of normal aging processes. Exposure of aged animals to an enriched environment (EE) counteracts this decline, an effect correlated with reduction of age-related changes in hippocampal dendritic branching, spine density, neurogenesis, gliogenesis, and neural plasticity, including its epigenetic underpinnings. Declarative memories depend on the medial temporal lobe system, including the hippocampus, for their formation, but, over days to weeks, they become increasingly dependent on other brain regions such as the neocortex and in particular the prefrontal cortex (PFC), a process known as system consolidation. Recently, it has been shown that early tagging of cortical networks is a crucial neurobiological process for remote memory formation and that this tagging involves epigenetic mechanisms in the recipient orbitofrontal (OFC) areas. Whether EE can enhance system consolidation in aged animals has not been tested; in particular, whether the early tagging mechanisms in OFC areas are deficient in aged animals and whether EE can ameliorate them is not known. This study aimed at testing whether EE could affect system consolidation in aged mice using the social transmission of food preference paradigm, which involves an ethologically based form of associative olfactory memory. We found that only EE mice successfully performed the remote memory recall task, showed neuronal activation in OFC, assessed with c-fos immunohistochemistry and early tagging of OFC, assessed with histone H3 acetylation, suggesting a defective system consolidation and early OFC tagging in aged mice which are ameliorated by EE.


Assuntos
Envelhecimento/fisiologia , Epigênese Genética/fisiologia , Preferências Alimentares/fisiologia , Memória de Longo Prazo/fisiologia , Comportamento Social , Meio Social , Envelhecimento/psicologia , Animais , Feminino , Preferências Alimentares/psicologia , Hipocampo/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Plasticidade Neuronal/fisiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-28320726

RESUMO

Leishmaniasis is a neglected tropical disease caused by >20 species of the protozoan parasite Leishmania Meglumine antimoniate (Glucantime) is the first-choice drug recommended by the World Health Organization for the treatment of all types of leishmaniasis. However, the mechanisms of action and toxicity of pentavalent antimonials, including genotoxic effects, remain unclear. Therefore, the mechanism by which meglumine antimoniate causes DNA damage was investigated for BALB/c mice infected by Leishmania (Leishmania) infantum and treated with meglumine antimoniate (20 mg/kg for 20 days). DNA damage was analyzed by a comet assay using mouse leukocytes. Furthermore, comet assays were followed by treatment with formamidopyrimidine-DNA glycosylase and endonuclease III, which remove oxidized DNA bases. In addition, the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the animals' sera were assessed. To investigate mutagenicity, we carried out a micronucleus test. Our data demonstrate that meglumine antimoniate, as well as L. infantum infection, induces DNA damage in mammalian cells by the oxidation of nitrogenous bases. Additionally, the antileishmanial increased the frequency of micronucleated cells, confirming its mutagenic potential. According to our data, both meglumine antimoniate treatment and L. infantum infection promote oxidative stress-derived DNA damage, which promotes overactivation of the SOD-CAT axis, whereas the SOD-GPx axis is inhibited as a probable consequence of glutathione (GSH) depletion. Finally, our data enable us to suggest that a meglumine antimoniate regimen, as recommended by the World Health Organization, would compromise GPx activity, leading to the saturation of antioxidant defense systems that use thiol groups, and might be harmful to patients under treatment.


Assuntos
Antiprotozoários/uso terapêutico , Leishmania infantum/patogenicidade , Leishmaniose/tratamento farmacológico , Leishmaniose/genética , Meglumina/uso terapêutico , Compostos Organometálicos/uso terapêutico , Animais , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Leishmania infantum/efeitos dos fármacos , Antimoniato de Meglumina , Camundongos , Camundongos Endogâmicos BALB C
10.
Nanomedicine ; 13(5): 1693-1701, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28343016

RESUMO

Chemotherapy for bone tumors is a major challenge because of the inability of therapeutics to penetrate dense bone mineral. We hypothesize that a nanostructured formulation with high affinity for bone could deliver drug to the tumor while minimizing off-target toxicity. Here, we evaluated the efficacy and toxicity of a novel bone-targeted, pH-sensitive liposomal formulation containing doxorubicin in an animal model of bone metastasis. Biodistribution studies with the liposome showed good uptake in tumor, but low accumulation of doxorubicin in the heart. Mice treated with the bone-targeted liposome formulation showed a 70% reduction in tumor volume, compared to 35% reduction for free doxorubicin at the same dose. Both cardiac toxicity and overall mortality were significantly lower for animals treated with the bone-targeted liposomes compared to free drug. Bone-targeted, pH-sensitive, doxorubicin containing liposomes represent a promising approach to selectively delivering doxorubicin to bone tumors while minimizing cardiac toxicity.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Neoplasias Ósseas/tratamento farmacológico , Doxorrubicina/administração & dosagem , Lipossomos , Animais , Antibióticos Antineoplásicos/toxicidade , Neoplasias Ósseas/secundário , Cardiotoxicidade , Doxorrubicina/toxicidade , Concentração de Íons de Hidrogênio , Camundongos , Distribuição Tecidual
11.
Aging Ment Health ; 21(1): 58-65, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27936876

RESUMO

OBJECTIVES: Information and communication technologies (ICT) developers, together with dementia experts have created several technological solutions to improve and facilitate social health and social participation and quality of life of older adults living with dementia. However, there is a need to carry out a systematic literature review that focuses on the validity and efficacy of these new technologies assessing their utility to promote 'social health' and 'active ageing' in people with dementia. METHOD: Searches in electronic databases identified 3824 articles of which 6 met the inclusion criteria and were coded according to their methodological approach, sample sizes, type of outcomes and results. RESULTS: Six papers were identified reporting the use of 10 different interventions with people with dementia. Qualitative studies (four) showed a benefit of the use of technologies to foster social participation in people with dementia. At the same time, barriers to a widespread use of these technologies in this population were identified. A quantitative study and a mixed-method study with quantitative outcomes showed that ICT-based interventions promote more social behaviours than non-technology-based interventions. CONCLUSIONS: In the last years, several technological devices for living independently and fostering social health and social participation in people with dementia have been developed. However, specific outcome measures to assess social health and social participation are needed. Even though the analysed studies provided some evidence-base for the use of technology in this field, there is an urge to develop high quality studies and specific outcome measures.


Assuntos
Sistemas Computacionais , Demência/psicologia , Qualidade de Vida , Participação Social , Tecnologia/normas , Idoso , Atenção à Saúde , Humanos , Ciência da Informação , Pesquisa Qualitativa , Comportamento Social
12.
Metab Brain Dis ; 31(4): 917-27, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27154727

RESUMO

Early-life environmental insults have been shown to promote long-term development of chronic non-communicable diseases, including metabolic disturbances and mental illnesses. As such, premature consumption of high-sugar foods has been associated to early onset of detrimental outcomes, whereas underlying mechanisms are still poorly understood. In the present study, we sought to investigate whether early and sustained exposure to high-sucrose diet promotes metabolic disturbances that ultimately might anticipate neurological injuries. At postnatal day 21, weaned male rats started to be fed a standard chow (10 % sucrose, CTR) or a high-sucrose diet (25 % sucrose, HSD) for 9 weeks prior to euthanasia at postnatal day 90. HSD did not alter weight gain and feed efficiency between groups, but increased visceral, non-visceral and brown adipose tissue accumulation. HSD rats demonstrated elevated blood glucose levels in both fasting and fed states, which were associated to impaired glucose tolerance. Peripheral insulin sensitivity did not change, whereas hepatic insulin resistance was supported by increased serum triglyceride levels, as well as higher TyG index values. Assessment of hippocampal gene expression showed endoplasmic reticulum (ER) stress pathways were activated in HSD rats, as compared to CTR. HSD rats had overexpression of unfolded protein response sensors, PERK and ATF6; ER chaperone, PDIA2 and apoptosis-related genes, CHOP and Caspase 3; but decreased expression of chaperone GRP78. Finally, HSD rats demonstrated impaired neuromuscular function and anxious behavior, but preserved cognitive parameters. In conclusion, our data indicate that early exposure to HSD promote metabolic disturbances, which disrupt hippocampus homeostasis and might precociously affect its neurobehavioral functions.


Assuntos
Comportamento Animal/efeitos dos fármacos , Sacarose Alimentar/administração & dosagem , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Síndrome Metabólica/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Ansiedade/metabolismo , Glucose/metabolismo , Hipocampo/metabolismo , Resistência à Insulina/fisiologia , Masculino , Ratos , Ratos Wistar , Triglicerídeos/metabolismo
13.
Artif Organs ; 39(2): 142-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25277688

RESUMO

Hemodiafiltration (HDF) with 20-22 L of substitution fluid is increasingly recognized as associated with significant benefits regarding patient outcome. However, some doubt exists as to whether these high volumes can be achieved in routine clinical practice. A total of 4176 sessions with 366 patients on postdilution HDF were analyzed in this 1-month observational cohort study with prospective data collection. All dialysis machines were equipped with AutoSub plus signal analysis software that automatically and continuously adapts the substitution fluid flow according to the blood flow, blood viscosity, and dialyzer characteristics. Percentages of sessions with different types of vascular access were compared regarding achievement of ≥21 L substitution fluid. Logistic regression analysis was conducted to study the independent relationship of selected variables with achievement of ≥21 L substitution volume. Patient- and dialysis-related variables that showed an association with the convection volume were entered in a multivariable model that included hematocrit up front. Respectively, 87%, 84%, and 33% of routine sessions conducted with fistulas, grafts, and catheters qualified as high-volume HDF. Serum albumin levels ≥4.2 g/dL were positively associated with the achievement of at least 21 L substitution volume. Positive associations were also observed for blood flows in the ranges 350-399 and ≥400 mL/min compared with the reference range (300-350 mL/min), for longer treatment time, for fistula versus catheter, for higher filtration fraction, and for dialysis conducted at the end of the week versus Monday. It can be concluded that implementation and sustainability of high-volume HDF is possible in routine clinical practice for almost all patients treated with fistulas and grafts.


Assuntos
Hemodiafiltração/métodos , Idoso , Velocidade do Fluxo Sanguíneo , Estudos de Coortes , Feminino , Hematócrito , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Albumina Sérica/análise
14.
Public Underst Sci ; 24(7): 776-93, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24327672

RESUMO

A study of a project on science stand-up comedy developed in Portugal between 2009 and 2013 is presented, in which thirteen scientists, coordinated by a science communicator and a professional actor, created and presented comedy acts. Eleven of these scientists were asked about their motivations to participate, the process of performance development and the perceived value of the project. Personal motivations were highly important, but professional reasons were also mentioned. Working in a group with the guidance of coordinators, testing and re-writing the texts and gradually gaining confidence on stage were considered fundamental in the development of the shows. Additionally, a questionnaire revealed that the audience, most of whom were young adults, and held a higher education degree, were satisfied with the show. Overall, both participating scientists and audience members considered that stand-up comedy has potential for science communication.


Assuntos
Comunicação , Ciência , Senso de Humor e Humor como Assunto , Humanos , Portugal , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto Jovem
15.
Chemosphere ; 357: 142026, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38615959

RESUMO

The consumption of antidepressants, such as fluoxetine, has increased over the years and, as a result, they are increasingly found in aquatic systems. Given the increasing use of zebrafish as an animal model in toxicological studies, this work proposed to evaluate the effects of chronic exposure, for 21 days, to fluoxetine at environmentally relevant concentrations (1, 10, 100, and 1000 ng/L). The behavioral tests performed did not reveal significant effects of fluoxetine. However, oxidative stress and changes in energy metabolism were detected after exposure to the highest concentrations of fluoxetine tested, namely a decrease in glutathione S-transferase (GST) activity (decrease of ca. 31%), increase in catalase (CAT) activity (increase of ca. 71%), and decrease in lactate dehydrogenase (LDH) activity (decrease of ca. 53%). Analysis of the fatty acid profile (FA) revealed a decrease in the omega-3 FA, docosahexaenoic acid (DHA), C22:6 (decrease in relative abundance between 6% and 8% for both the head and body), an increase in omega-6 FA, linoleic acid (LA), C18:2, (increased relative abundance between 8% and 11% in the head and between 5% and 9% in the body), which may suggest changes in the inflammatory state of these organisms. The integrated analysis adopted proved to be useful in detecting subindividual effects of fluoxetine and modes of action in fish.


Assuntos
Comportamento Animal , Ácidos Graxos , Fluoxetina , Estresse Oxidativo , Poluentes Químicos da Água , Peixe-Zebra , Fluoxetina/toxicidade , Animais , Poluentes Químicos da Água/toxicidade , Comportamento Animal/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ácidos Graxos/metabolismo , Glutationa Transferase/metabolismo , Catalase/metabolismo
16.
J Bras Pneumol ; 50(4): e20240165, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39356913

RESUMO

OBJECTIVE: To establish the accuracy of frozen section examination in identifying tumor spread through air spaces (STAS), as well as to propose a reproducible technical methodology for frozen section analysis. We also aim to propose a method to be incorporated into the decision making about the need for conversion to lobectomy during sublobar resection. METHODS: This was a nonrandomized prospective study of 38 patients with lung cancer who underwent surgical resection. The findings regarding STAS in the frozen section were compared with the definitive histopathological study of paraffin-embedded sections. We calculated a confusion matrix to obtain the positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity and accuracy. RESULTS: The intraoperative frozen section analysis identified 7 STAS-positive cases that were also positive in the histopathological examination, as well as 3 STAS-negative cases that were positive in the in the histopathological examination. Therefore, frozen section analysis was determined to have a sensitivity of 70%, specificity of 100%, PPV of 100%, NPV of 90.3%, and accuracy of 92% for identifying STAS. CONCLUSIONS: Frozen section analysis is capable of identifying STAS during resection in patients with lung cancer. The PPV, NPV, sensitivity, and specificity showed that the technique proposed could be incorporated at other centers and would allow advances directly linked to prognosis. In addition, given the high accuracy of the technique, it could inform intraoperative decisions regarding sublobar versus lobar resection.


Assuntos
Secções Congeladas , Neoplasias Pulmonares , Sensibilidade e Especificidade , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Estudos Prospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Reprodutibilidade dos Testes , Período Intraoperatório , Valor Preditivo dos Testes , Idoso de 80 Anos ou mais , Invasividade Neoplásica , Adulto , Cuidados Intraoperatórios/métodos , Pneumonectomia/métodos
17.
ACS Chem Neurosci ; 15(4): 699-715, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38305187

RESUMO

Atomic force microscopy (AFM) is a scanning probe microscopy technique which has a physical principle, the measurement of interatomic forces between a very thin tip and the surface of a sample, allowing the obtaining of quantitative data at the nanoscale, contributing to the surface study and mechanical characterization. Due to its great versatility, AFM has been used to investigate the structural and nanomechanical properties of several inorganic and biological materials, including neurons affected by tauopathies. Tauopathies are neurodegenerative diseases featured by aggregation of phosphorylated tau protein inside neurons, leading to functional loss and progressive neurotoxicity. In the broad universe of neurodegenerative diseases, tauopathies comprise the most prevalent, with Alzheimer's disease as its main representative. This review highlights the use of AFM as a suitable research technique for the study of cellular damages in tauopathies, even in early stages, allowing elucidation of pathogenic mechanisms of these diseases.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Tauopatias , Humanos , Microscopia de Força Atômica/métodos , Tauopatias/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/metabolismo , Doenças Neurodegenerativas/metabolismo , Neurônios/metabolismo
18.
ACS Omega ; 9(39): 40870-40881, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39371966

RESUMO

Diabetes Mellitus (DM) is a disease characterized by high blood glucose levels, known as hyperglycemia. Diabetes represents a risk factor for the development of neurodegenerative diseases, such as Alzheimer's Disease (AD), one of the most prevalent neurodegenerative diseases worldwide, which leads to progressive mental, behavioral, and functional decline, affecting many brain structures, especially the hippocampus. Here, we aim to characterize the ultrastructural, nanomechanical, and vibrational changes in hyperglycemic hippocampal tissue using atomic force microscopy (AFM) and Raman spectroscopy. DM was induced in rats by streptozotocin injection (type 1) or dietary intervention (type 2). Cryosections of the hippocampus were prepared and analyzed on an MM8 AFM (Bruker) in Peak Force Quantitative Nanomechanics mode, performing 25 µm2 scans in 9 regions of 3 samples from each group. Ultrastructural and nanomechanical data such as surface roughness, area, volume, Young's modulus, and adhesion were evaluated. The hippocampal samples were also analyzed on a T64000 Spectrometer (Horiba), using a laser λ = 632.8 nm, and for each sample, four spectra were obtained in different regions. AFM analyses show changes on the ultrastructural scale since diabetic animals had hippocampal tissue with greater roughness and volume. Meanwhile, diabetic tissues had decreased adhesion and Young's modulus compared to control tissues. These were corroboratedby Raman data that shows changes in the molecular composition of diabetic tissues. The individual spectra show that the most significant changes are in the amide, cholesterol, and lipid bands. Overall, the data presented here show that hyperglycemia induces biophysical alterations in the hippocampal tissue of diabetic rats, providing novel biophysical and vibrational cues on the relationship between hyperglycemia and dementia.

19.
Artigo em Inglês | MEDLINE | ID: mdl-39368680

RESUMO

BACKGROUND: Recent clinical series on donation after uncontrolled cardiovascular death (uDCD) reported successful transplantation of lungs preserved by pulmonary inflation up to 3h post-mortem. This study aims to investigate the additive effects of in situ lowering of intrathoracic temperature and sevoflurane preconditioning on lung grafts in a porcine uDCD model. METHODS: After uDCD induction, donor pigs were allocated to one of the following groups: Control - static lung inflation only (SLI); TC - SLI + continuous intrapleural topical cooling (TC); or TC+Sevo - SLI + TC + sevoflurane. Lungs were retrieved 6h post-asystole and evaluated via ex vivo lung perfusion (EVLP) for 6h. A left single lung transplant was performed using lungs from the best performing group, followed by 4h of graft evaluation. RESULTS: Animals that received topical cooling achieved intrathoracic temperature < 15°C within 1 hour after chest filling of coolant. Only lungs from donors that received TC and TC+Sevo completed the planned post-preservation 6h EVLP assessment. Despite similar early performance of the two groups on EVLP, the TC+Sevo group was superior - associated with overall lower airway pressures, higher pulmonary compliances, less edema development, and less release of inflammatory cytokines. Transplantation was performed using lungs from the TC+Sevo group, and excellent graft function was observed post-reperfusion. CONCLUSION: Preservation of uDCD lungs with a combination of static lung inflation, topical cooling and sevoflurane treatment maintains good pulmonary function up to 6h post-mortem with excellent early post-lung transplant function. These interventions may significantly expand the clinical utilization of uDCD donor lungs.

20.
Public Underst Sci ; 32(4): 459-469, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36448498

RESUMO

The media play an important role in informing us about new developments in our understanding of the sea and raising awareness about its sustainability. However, press coverage of marine issues seems to be modest, compared with the importance oceans have in our lives. In this study, we examine science journalists' working contexts, motivations, and difficulties in writing about the sea in Europe. We conducted semi-structured interviews with 26 journalists who write for quality newspapers from 13 European countries. We found that the recent production of press news on marine issues is mainly conditioned by working contexts in newspapers, the personal and professional interests of journalists, and the available resources to write news. More studies are needed to compare our findings, including with other regions outside Europe.


Assuntos
Meios de Comunicação de Massa , Motivação , Europa (Continente) , Redação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA