Novel bilayered Gellan gum/Gellan gum hydroxyapatite scaffolds for osteochondral tissue engineering applications

Osteoarthritis is a major cause of disability during aging. By the age of 60, close to 100% of the population will have histologic changes of degeneration in their knee cartilage (Loeser, 2000). Because of its avascular nature, cartilage has little capacity to self-regenerate. Despite the progress already achieved in osteochondral regeneration, some limitations have to be overcome. The formation of fibrocartilage has to be avoided and the innervation has to be improved. Further, one main feature to be promoted is the induction of vascularization in the bony part but not in the cartilage part and to avoid de-differentiation processes. A promising strategy could pass through the development and optimization of novel culture systems. The ideal approach could integrate scaffolds presenting regions with different physical characteristics, combined with different growth factors to support different stem cells fates, regarding the complex tissue physiology to be regenerate. This work aims to develop novel bilayered gellan gum (GG)/gellan gumhydroxyapatite (HAp) hydrogels based structures for osteochondral tissue engineering applications. Bilayered GG/GG-HAp hydrogels were produced by joining both solutions of GG 2% (w/v) with and without HAp (20% wt.) for bony and cartilage parts, respectively. The solutions were introduced into a silicone mould with 20:10 mm (height and diameter, respectively). Gelation of GG was promoted by immersion in PBS solution for 24 h. The architecture of the bilayered scaffolds was investigated by micro-computed tomography. Results have shown that the freeze-dried bilayered scaffolds composed by low acyl GG(2%(w/ v)/low acyl GG(2%(w/v)-HAp20%(w/w) possess a porosity of 83.4 ± 0.8%, pore size of 279.3 ± 38.6 lm and interconnectivity of 62.2 ± 5.4%. Degradability assays are being performed with the intent to use this system to culture human adipose derived stem cells inducing cell co-differentiation into chondrocytes and osteoblasts. Ultimately, the developed bilayered scaffolds will provide new therapeutic possibilities for the regeneration of osteochondral defects

Gellan gum-based hydrogel bilayered scaffolds for osteochondral tissue engineering

It has been shown that hydrogel bilayered scaffolds combining cartilage- and bone-like layers are most advantageous for treating osteochondral defects. In this study, it is proposed the use of low acyl gellan gum (LAGG) for developing bilayered hydrogel scaffolds for osteochondral tissue engineering. The cartilage-like layer of the GG-based bilayered hydrogel scaffolds is composed of LAGG (2 wt%). By adding a 2 wt% LAGG aqueous solution to different amounts of HAp (5-20 wt%) it was possible to produce the bone-like layer. In vitro bioactivity tests were performed by means of soaking the LAGG/LAGG-HAp hydrogel scaffolds in a simulated body fluid solution up to 14 days. Scanning electron microscopy, Fourier transform infra-red spectroscopy and X-ray diffraction analyses demonstrated that apatite formation is limited to the bone-like layer of the LAGG/LAGG-HAp bilayered hydrogel scaffolds

Posterior talar process as a suitable cell source for treatment of cartilage and osteochondral defects of the talus

Osteochondral defects of the ankle are common lesions affecting the talar cartilage and subchondral bone. Current treatments include cell-based therapies but are frequently associated with donor-site morbidity. Our objective is to characterize the posterior process of the talus (SP) and the os trigonum (OT) tissues and investigate its potential as a new source of viable cells for application in tissue engineering and regenerative medicine.SP and OT tissues obtained from six patients were characterized by micro-computed tomography, and histological, histomorphometric and immunohistochemical analyses. Isolated cells proliferation and viability were evaluated by MTS assay, DNA quantification and Live/Dead staining. The TUNEL assay was performed to evaluate cell death by apoptosis. Moreover, the production of extracellular matrix was evaluated by toluidine blue staining, whereas cells phenotype was investigated by flow cytometry. Ankle explants characterization showed the presence of a cartilage tissue layer in both SP and OT tissues, which represent, at least 20% in average of the explant. The presence of type II collagen was detected in the extracellular matrix. Isolated cells presented a round morphology typical of chondrocytes. In in vitro studies, cells were viable and proliferating up to 21 days of culturing. No signs of apoptosis were detected. Flow cytometry analysis revealed that isolated cells maintained the expression of several chondrocytic markers during culturing. The results indicate that the SP and OT tissues are a reliable source of viable chondrocytes, which can find promising applications in ACI/MACI strategies with minimal concerns regarding donor zone complications.Portuguese Foundation for Science and Technology (FCT) through the project OsteoCart (Grant No. PTDC/CTM-BPC/115977/2009), Fundación MAPFRE (Ayudas a la Investigación Ignacio H. de Larramendi, Prevención, Salud y Medio Ambiente, Spain) under the project 'Preventing the progression of the knee osteoarthritis: advanced therapies combining injectable hydrogels, autologous stem cells and PRP' (Grant No. BIL/13/SA/235). This study was also carried out with the support of Fundo Europeu de Desenvolvimento Regional (FEDER) through Programa Operacional do Norte through the project Articulate (Grant No. 23189

Acute effects of transcranial direct current stimulation (tDCS) on peak torque and 5000 m running performance: a randomized controlled trial

The benefits of transcranial direct current stimulation (tDCS) on brain function, cognitive response, and motor ability are well described in scientific literature. Nevertheless, the effects of tDCS on athletes’ performance remain unclear. To compare the acute effects of tDCS on the running performance of 5000 m (m) runners. Eighteen athletes were randomized into Anodal (n = 9) groups that received tDCS for 20 min and 2 mA, and Sham (n = 9), in the motor cortex region (M1). Running time in 5000 m, speed, perceived exertion (RPE), internal load and peak torque (Pt) were evaluated. The Shapiro–Wilk test followed by a paired Student’s t-test was used to compare Pt and total time to complete the run between the groups. The running time and speed of the Anodal group (p = 0.02; 95% CI 0.11–2.32; d = 1.24) was lower than the Sham group (p = 0.02, 95% CI 0.05–2.20; d = 1.15). However, no difference was found in Pt (p = 0.70; 95% CI − 0.75 to 1.11; d = 0.18), RPE (p = 0.23; 95% CI − 1.55 to 0.39; d = 0.60) and internal charge (p = 0.73; 95% CI − 0.77 to 1.09; d = 0.17). Our data indicate that tDCS can acutely optimize the time and speed of 5000 m runners. However, no alterations were found for Pt and RPE

Manejo da hanseníase na atenção primária: diagnóstico e tratamento / Leprosy management in primary care: diagnosis and treatment

A Hanseníase é uma patologia de evolução alongada, e seu agente causador é o Mycobacterium leprae. Seus sinais e sintomas são no nível dermatoneurológico. Nesse contexto, esse estudo tem por objetivo geral analisar por meio da pesquisa baseada em evidências - PBE- achados da literatura, sobre estigmas que envolvem pacientes com hanseníase e praticas da educação em saude durante o tratamento na atenção básica. Pesquisa baseada em evidências, utilizando os indexadores Pubmed, Scielo e Cohcrane com os seguintes filtros: resumo abstract, textos open access, idioma português e inglês, período 2016 a 2021. Também foram utilizados manuais e boletins epidemiológicos disponíveis na página do Ministério da Saúde. O material foi selecionado de modo a buscar responder os objetivos dessa pesquisa e portanto utilizou os descritores em saúde: hanseníase, atenção básica, diagnóstico, tratamento. Foram abordadas práticas de educação em saude que envolvem orientações e estigmas em saude. Entende-se que o manejo da hanseníase envolve sensibilidade, consciência e sobretudo conhecimento embasado para consubstanciar a prática clínica

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Mielomeningocele e anomalias associadas: uma série de casos e revisão sistemática

A mielomeningocele é uma malformação congênita grave do sistema nervoso central, representando um dos tipos mais complexos de defeitos do tubo neural. A condição é marcada pela exposição das meninges e, em alguns casos, da medula espinhal, através de uma abertura na coluna vertebral, desafiando tanto o prognóstico do paciente quanto as estratégias de tratamento. O presente estudo visa explorar os avanços recentes no diagnóstico, intervenções cirúrgicas e desfechos neurológicos associados à mielomeningocele, com foco particular na eficácia e segurança das abordagens atuais. Para isso, foi realizada uma revisão sistemática da literatura de 2016 a 2024 nas bases de dados PubMed (Medline), Cochrane Library e SciELO, aplicando critérios de inclusão e exclusão rigorosos para selecionar estudos que abordassem esses aspectos. Três estudos chave foram analisados, destacando-se pelas técnicas de diagnóstico antenatal, pela utilização de intervenções cirúrgicas inovadoras, como o fechamento fetal, e pelos cuidados pós-operatórios visando melhorias nos desfechos neurológicos. Os resultados indicam uma tendência positiva na melhoria da qualidade de vida dos pacientes, com avanços significativos no controle e na prevenção de complicações a longo prazo. No entanto, foi observada a necessidade de uma abordagem multidisciplinar no tratamento, integrando cuidados neurocirúrgicos, ortopédicos e reabilitativos. A mielomeningocele, apesar dos desafios, tem testemunhado progressos notáveis nas últimas décadas, sugerindo um futuro mais promissor para os pacientes afetados. Ainda assim, são necessários mais estudos para consolidar essas abordagens e otimizar as estratégias de tratamento na prática clínica

Alterações cognitivas na infecção pelo HIV: uma revisão sistemática: Cognitive changes in HIV infection: a systematic review

Provocada pelo vírus da imunodeficiência humana, com a síndrome da imunodeficiência adquirida, numa pessoa tem o seu sistema imunológico prejudicado, tornando-se suscetível a outras doenças e infecção. Tem-se a estimativa de que 50% dos infectados com o referido vírus podem sofrer alterações cognitivas. Diante disso, este estudo tem como objetivo refletir sobre mudanças estruturais cerebrais e comprometimento cognitivo em pacientes com HIV. Portanto, trata-se de uma revisão sistemática de literatura, desenvolvida a partir da seleção de estudos nas bases de dados Scielo, Pubmed e BVS/Medline a partir do uso de descritores DeCS/MeSH e aplicação de critérios de inclusão e exclusão. Após a análise e interpretação dos dados, concluiu-se que há uma significativa prevalência de HAND em adultos infectados por HIV, no que se refere a alterações cognitivas, especialmente entre pacientes do sexo feminino, de baixa escolaridade e renda, com diagnóstico tardio e baixa quantidade de linfócitos CD4 no início do tratamento. Entre essas pessoas, revelam-se comprometimentos quanto à memória, atenção, controle de impulsos, velocidade de processamento e motora, dentre outros