155 research outputs found
Tackling Ischemic Reperfusion Injury With the Aid of Stem Cells and Tissue Engineering
Ischemia is a severe condition in which blood supply, including oxygen (O), to organs and tissues is interrupted and reduced. This is usually due to a clog or blockage in the arteries that feed the affected organ. Reinstatement of blood flow is essential to salvage ischemic tissues, restoring O, and nutrient supply. However, reperfusion itself may lead to major adverse consequences. Ischemia-reperfusion injury is often prompted by the local and systemic inflammatory reaction, as well as oxidative stress, and contributes to organ and tissue damage. In addition, the duration and consecutive ischemia-reperfusion cycles are related to the severity of the damage and could lead to chronic wounds. Clinical pathophysiological conditions associated with reperfusion events, including stroke, myocardial infarction, wounds, lung, renal, liver, and intestinal damage or failure, are concomitant in due process with a disability, morbidity, and mortality. Consequently, preventive or palliative therapies for this injury are in demand. Tissue engineering offers a promising toolset to tackle ischemia-reperfusion injuries. It devises tissue-mimetics by using the following: (1) the unique therapeutic features of stem cells, i.e., self-renewal, differentiability, anti-inflammatory, and immunosuppressants effects; (2) growth factors to drive cell growth, and development; (3) functional biomaterials, to provide defined microarchitecture for cell-cell interactions; (4) bioprocess design tools to emulate the macroscopic environment that interacts with tissues. This strategy allows the production of cell therapeutics capable of addressing ischemia-reperfusion injury (IRI). In addition, it allows the development of physiological-tissue-mimetics to study this condition or to assess the effect of drugs. Thus, it provides a sound platform for a better understanding of the reperfusion condition. This review article presents a synopsis and discusses tissue engineering applications available to treat various types of ischemia-reperfusions, ultimately aiming to highlight possible therapies and to bring closer the gap between preclinical and clinical settings
Produção e caracterização de MPB70 de Mycobacterium bovis para uso em imunodiagnóstico.
Demonstrou-se a produção e caracterização de MPB70 recombinante de M. bovis.bitstream/CNPGC-2010/13223/1/COT119.pd
Current state of molecular and metabolic strategies for the improvement of L-asparaginase expression in heterologous systems
Heterologous expression of L-asparaginase (L-ASNase) has become an important area of research due to its clinical and food industry applications. This review provides a comprehensive overview of the molecular and metabolic strategies that can be used to optimize the expression of L-ASNase in heterologous systems. This article describes various approaches that have been employed to increase enzyme production, including the use of molecular tools, strain engineering, and in silico optimization. The review article highlights the critical role that rational design plays in achieving successful heterologous expression and underscores the challenges of large-scale production of L-ASNase, such as inadequate protein folding and the metabolic burden on host cells. Improved gene expression is shown to be achievable through the optimization of codon usage, synthetic promoters, transcription and translation regulation, and host strain improvement, among others. Additionally, this review provides a deep understanding of the enzymatic properties of L-ASNase and how this knowledge has been employed to enhance its properties and production. Finally, future trends in L-ASNase production, including the integration of CRISPR and machine learning tools are discussed. This work serves as a valuable resource for researchers looking to design effective heterologous expression systems for L-ASNase production as well as for enzymes production in general
Study of the membrane lipid compostion of Atlantic salmon (Salmon salar) spermatozoa and its relaction with semen quality
Protein phosphorylation and ions effects on salmonid sperm motility activation
Sperm motility is considered as a key factor allowing determination of semen quality and predicts fertilizing capacity. In many fish species, the spermatozoa are immotile in the testes and seminal plasma, and motility is induced when they are released in the aqueous environment. Initiation and activation of sperm motility are prerequisite processes for the contact and fusion of male and female gametes at fertilization. Many proteins are involved in the activation of sperm motility in many species. Cell signalling for the initiation of sperm motility in the salmonid fish has drawn much attention during the last two decades. In some species, protein phosphorylation process was shown to be involved in flagellar motility regulation. Hyperpolarization of the sperm membrane induces synthesis of cAMP (cyclic AMP), which triggers further cell signalling processes, such as cAMP-dependent protein phosphorylation that finally initiates sperm motility in salmonid fish. Ions such as Na+, K+ and Ca2+ play also an important role in the activation of sperm motility in many species, more specifically in salmonids. Salmonid fish sperm motility can be suppressed by millimolar concentrations of extracellular K+, and dilution of K+ upon spawning is enough to trigger the cAMP-dependent signalling cascade leading to motility initiation. This review aims to update the present knowledge about the roles of ions and protein phosphorylation process in the sperm motility activation in salmonid
Um Avaliador Automático de Eficiência de Algoritmos para Ambientes Educacionais de Ensino de Programação
Existem características importantes que devem ser observadas no projeto de algoritmos que são fundamentais no seu uso, uma delas é a eficiência. Portanto, se torna necessário que esse aspecto seja enfatizado durante o processo de ensino e aprendizagem de algoritmos. Este trabalho propõe uma solução automática para a medição da eficiência dos algoritmos através da implementação de um componente que adota métodos matemáticos que combinam o uso de análise experimental e assintótica para avaliar a complexidade dos algoritmos. Este componente foi desenvolvido e testado para o IGED e MOCCA, ferramentas educacionais para ensino de algoritmos e estrutura de dados. Em nossos experimentos computacionais obtemos uma análise assintótica efetiva sobre sete algoritmos clássicos
Polymeric nanoparticles of Brazilian red propolis extract : preparation, characterization, antioxidant and leishmanicidal activity
The ever-increasing demand for natural products and biotechnology derived from bees and ultra-modernization of various analytical devices has facilitated the rational and planned development of biotechnology products with a focus on human health to treat chronic and neglected diseases. The aim of the present study was to prepare and characterize polymeric nanoparticles loaded with Brazilian red propolis extract and evaluate the cytotoxic activity of "multiple-constituent extract in co-delivery system" for antileishmanial therapies. The polymeric nanoparticles loaded with red propolis extract were prepared with a combination of poly-ε-caprolactone and pluronic using nanoprecipitation method and characterized by different analytical techniques, antioxidant and leishmanicidal assay. The red propolis nanoparticles in aqueous medium presented particle size (200–280 nm) in nanometric scale and zeta analysis (−20 to −26 mV) revealed stability of the nanoparticles without aggregation phenomenon during 1 month. After freeze-drying method using cryoprotectant (sodium starch glycolate), it was possible to observe particles with smooth and spherical shape and apparent size of 200 to 400 nm. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermal analysis revealed the encapsulation of the flavonoids from the red propolis extract into the polymeric matrix. Ultra performance liquid chromatography coupled with diode array detector (UPLC-DAD) identified the flavonoids liquiritigenin, pinobanksin, isoliquiritigenin, formononetin and biochanin A in ethanolic extract of propolis (EEP) and nanoparticles of red propolis extract (NRPE). The efficiency of encapsulation was determinate, and median values (75.0 %) were calculated using UPLC-DAD. 2,2-Diphenyl-1-picryhydrazyl method showed antioxidant activity to EEP and red propolis nanoparticles. Compared to negative control, EEP and NRPE exhibited leishmanicidal activity with an IC50 value of ≅38.0 μg/mL and 31.3 μg/mL, 47.2 μg/mL, 154.2μg/mL and 193.2 μg/mL for NRPE A1, NRPE A2, NRPE A3 and NRPE A4, respectively. Nanoparticles loaded with red propolis extract in co-delivery system and EEP presented cytotoxic activity on Leishmania (V.) braziliensis. Red propolis extract loaded in nanoparticles has shown to be potential candidates as intermediate products for preparation of various pharmaceutical dosage forms containing red propolis extract in the therapy against negligible diseases such as leishmaniasis
RENDIMENTO FORRAGEIRO E COMPOSIÇÃO BROMATOLÓGICA DE MILHETO SOB ADUBAÇÃO NITROGENADA
Realizou-se um experimento com milheto (Pennisetum glaucum) cv. ADR-300 sob doses de nitrogênio (0, 50, 100 e 150 kg.ha-1) em regimes de cortes em duas alturas residuais (0,20 e 0,25 m), para se avaliar o potencial de produção e composição bromatológica da massa seca. O trabalho foi conduzido na Escola de Veterinária /UFG. O delineamento experimental foi o de blocos casualizados em esquema fatorial 2 x 3 x 4, com três repetições. Avaliou-se a produção de massa seca (PMS), teor de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA). A PMS diferiu (P<0,05) entre as doses de N e cortes de avaliações. Houve decréscimo no teor de MS à medida que as doses de N se elevaram. O acréscimo das doses de N promoveu uma elevação dos teores de PB do milheto, em todos os cortes. Houve decréscimo no teor de PB com a sucessão dos cortes. Os teores de FDN e FDA diferiram (P<0,05) com a sucessão dos cortes em ambas as alturas. Houve variação na produção e composição bromatológica do milheto mediante os tratamentos aplicados, assim, recomenda-se para a alimentação animal a utilização dessa planta forrageira na altura residual de 0,25 m e com aplicação da dose de 150 kg.ha-1 de N.
PALAVRAS-CHAVE: altura residual; nitrogênio; Pennisetum glaucum; produção de massa seca; proteína bruta
Functional genomic analyses uncover APOE-mediated regulation of brain and cerebrospinal fluid beta-amyloid levels in Parkinson disease
Alpha-synuclein is the main protein component of Lewy bodies, the pathological hallmark of Parkinson\u27s disease. However, genetic modifiers of cerebrospinal fluid (CSF) alpha-synuclein levels remain unknown. The use of CSF levels of amyloid bet
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