RESUMO
The best amylolytic activity production by Aspergillus clavatus UEM 04 occurred in submersed culture, with starch, for 72 h, at 25 °C, and 100 rpm. Exclusion chromatography partially purified two enzymes, which ran as unique bands in SDS-PAGE with approximately 84 kDa. LC-MS/MS identified a glucoamylase (GH15) and an α-amylase (GH13_1) as the predominant proteins and other co-purified proteins. Zn2+, Cu2+, and Mn2+ activated the glucoamylase, and SDS, Zn2+, Fe3+, and Cu2+ inhibited the α-amylase. The α-amylase optimum pH was 6.5. The optimal temperatures for the glucoamylase and α-amylase were 50 °C and 40 °C, and the Tm was 53.1 °C and 56.3 °C, respectively. Both enzymes remained almost fully active for 28-32 h at 40 °C, but the α-amylase thermal stability was calcium-dependent. Furthermore, the glucoamylase and α-amylase KM for starch were 2.95 and 1.0 mg/mL, respectively. Still, the Vmax was 0.28 µmol/min of released glucose for glucoamylase and 0.1 mg/min of consumed starch for α-amylase. Moreover, the glucoamylase showed greater affinity for amylopectin and α-amylase for maltodextrin. Additionally, both enzymes efficiently degraded raw starch. At last, glucose was the main product of glucoamylase, and α-amylase produced mainly maltose from gelatinized soluble starch hydrolysis.
Assuntos
Glucana 1,4-alfa-Glucosidase , alfa-Amilases , alfa-Amilases/metabolismo , Glucana 1,4-alfa-Glucosidase/metabolismo , Amido/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Glucose , Concentração de Íons de HidrogênioRESUMO
Objective: To assess the survival rate of patients with colorectal cancer at Hospital Universitário Alzira Vellano, in the municipality of Alfenas, state of Minas Gerais (MG), Brazil, from 2007 to 2016. Methodology: A search was conducted in the laboratory files and medical records of patients diagnosed with colorectal cancer and cared for during the aforementioned period. Results: In total, 128 cases were found: 52.3% were men, and 47.7% were women, with ages ranging from 25 to 91 years. The most common types of cancer in both genders were of the colon, rectum and sigmoid. The most common stages were T3N1Mx, followed by T3N0Mx and T3N2Mx. Patients with T1 or T2 cancers had a 100% survival rate, whereas the rate for those with grade 4 (T4) was of 0%. An association (p<0.05) of the location of the tumor with the survival rate was confirmed. Conclusion: There was a high mortality rate among patients diagnosed with colorectal cancer at Hospital Universitário Alzira Vellano from 2007 to 2016. (AU)
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Neoplasias Intestinais/mortalidade , Taxa de SobrevidaRESUMO
Early life stress such as physical abuse, trauma or neglect during a critical period of development can elicit negative long-lasting effects on health. Neonatal maternal deprivation (MD) is a stressful event capable of triggering structural and neurobiological changes in Central Nervous System (CNS) development during proliferative and migratory cell differentiation. In this study, we investigated the maternal behavior of lactating rats submitted to protocol of chronic neonatal maternal deprivation (MD) during postnatal day (PND) 1 until 10. We analyzed the effects of the MD in the olfactory memory and cellular proliferation and differentiation in the hippocampus and olfactory bulb in Wistar rat pups on 7, 11 and 21â¯days postpartum. Analysis in active neurons, cellular differentiation and proliferation, were marked and evaluated by flow cytometry in tissue samples of hippocampi and olfactory bulb. Our results demonstrated an increase in maternal behavior immediately after dam's return to the home-cage in MD group compared to the non-deprived group. In addition, MD pups spent more time (higher latency) to identify the nest odor in comparison to the non-deprived rat pups in the olfactory learning task and showed a significant delay in the neural differentiation and proliferation in the hippocampus and olfactory bulb. These results reveal that disruptions in the mother-infant bonding by the MD induce changes in maternal behavior and interaction with the offspring that could be leading to delayed CNS development and significant impairment in offspring's olfactory learning.
Assuntos
Aprendizagem/fisiologia , Comportamento Materno , Privação Materna , Neurônios/fisiologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Animais Recém-Nascidos/fisiologia , Feminino , Citometria de Fluxo , Hipocampo/crescimento & desenvolvimento , Hipocampo/fisiologia , Masculino , Memória/fisiologia , Bulbo Olfatório/crescimento & desenvolvimento , Bulbo Olfatório/fisiologia , Gravidez , Ratos , Ratos Wistar , Olfato/fisiologiaRESUMO
AIM: Scaffolds are a promising approach for spinal cord injury (SCI) treatment. FGF-2 is involved in tissue repair but is easily degradable and presents collateral effects in systemic administration. In order to address the stability issue and avoid the systemic effects, FGF-2 was encapsulated into core-shell microfibers by coaxial electrospinning and its in vitro and in vivo potential were studied. Materials & methods: The fibers were characterized by physicochemical and biological parameters. The scaffolds were implanted in a hemisection SCI rat model. Locomotor test was performed weekly for 6 weeks. After this time, histological analyses were performed and expression of nestin and GFAP was quantified by flow cytometry. Results: Electrospinning resulted in uniform microfibers with a core-shell structure, with a sustained liberation of FGF-2 from the fibers. The fibers supported PC12 cells adhesion and proliferation. Implanted scaffolds into SCI promoted locomotor recovery at 28 days after injury and reduced GFAP expression. CONCLUSION: These results indicate the potential of these microfibers in SCI tissue engineering. [Formula: see text].
Assuntos
Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Medula Espinal/patologia , Engenharia Tecidual/métodos , Alicerces Teciduais , Animais , Teste de Materiais , Células PC12 , Ratos , Medula Espinal/metabolismo , Medula Espinal/ultraestrutura , Traumatismos da Medula Espinal/terapiaRESUMO
Sugar cane is an important crop for sugar and biofuel production. Its lignocellulosic biomass represents a promising option as feedstock for second-generation ethanol production. Nitrogen fertilization can affect differently tissues and its biopolymers, including the cell-wall polysaccharides and lignin. Lignin content and composition are the most important factors associated with biomass recalcitrance to convert cell-wall polysaccharides into fermentable sugars. Thus it is important to understand the metabolic relationship between nitrogen fertilization and lignin in this feedstock. In this study, a large-scale proteomics approach based on GeLC-MS/MS was employed to identify and relatively quantify proteins differently accumulated in two contrasting genotypes for lignin composition after excessive nitrogen fertilization. From the â¼1000 nonredundant proteins identified, 28 and 177 were differentially accumulated in response to nitrogen from IACSP04-065 and IACSP04-627 lines, respectively. These proteins were associated with several functional categories, including carbon metabolism, amino acid metabolism, protein turnover, and oxidative stress. Although nitrogen fertilization has not changed lignin content, phenolic acids and lignin composition were changed in both species but not in the same way. Sucrose and reducing sugars increased in plants of the genotype IACSP04-065 receiving nitrogen.
Assuntos
Biocombustíveis , Plantas Geneticamente Modificadas/genética , Proteoma/genética , Saccharum/genética , Biomassa , Carboidratos/química , Carboidratos/genética , Fermentação , Regulação da Expressão Gênica de Plantas , Genótipo , Lignina/química , Lignina/metabolismo , Nitrogênio/química , Nitrogênio/metabolismo , Oxidantes/química , Oxidantes/metabolismo , Fenótipo , Plantas Geneticamente Modificadas/metabolismo , Proteoma/química , Saccharum/metabolismoRESUMO
The maintenance of viable and functional pancreatic islets is crucial for successful islet transplantation from brain-dead donors. To overcome islet quality loss during culture, some studies have co-cultured islets with mesenchymal stem/stromal cells (MSC). However, it is still uncertain if MSC-secreted factors are enough to improve islet quality or if a physical contact between MSCs and islets is needed. Therefore, we performed a systematic review and meta-analysis to clarify the effect of different culture contact systems of islets with MSCs on viability and insulin secretion outcomes. Pubmed and Embase were searched. Twenty studies fulfilled the eligibility criteria and were included in the qualitative synthesis and/or meta-analysis. For both outcomes, pooled weighted mean differences (WMD) between islet cultured alone (control group) and the co-culture condition were calculated. Viability mean was higher in islets co-cultured with MSCs compared with islet cultured alone [WMD = 18.08 (95% CI 12.59-23.57)]. The improvement in viability was higher in islets co-cultured in indirect or mixed contact with MSCs than in direct physical contact (P <0.001). Moreover, the mean of insulin stimulation index (ISI) was higher in islets from co-culture condition compared with islet cultured alone [WMD = 0.83 (95% CI 0.54-1.13)], independently of contact system. Results from the studies that were analyzed only qualitatively are in accordance with meta-analysis data. Co-culture of islets with MSCs has the potential for protecting islets from injury during culture period. Moreover, culture time appears to influence the beneficial effect of different methods of co-culture on viability and function of islets.
Assuntos
Técnicas de Cocultura , Insulina/metabolismo , Ilhotas Pancreáticas/citologia , Células-Tronco Mesenquimais/citologia , Animais , Humanos , Secreção de Insulina , Ilhotas Pancreáticas/metabolismoRESUMO
Engineering neural tissue by combining biodegradable materials, cells and growth factors is a promising strategy for the treatment of central and peripheral nervous system injuries. In this study, neural differentiation of mouse embryonic stem cells (mESCs) was investigated in combination with three dimensional (3D) electrospun nanofibers as a substitute for the extracellular matrix (ECM). Nano/microfibrous poly(lactic-co-glycolic acid) (PLGA) 3D scaffolds were fabricated through electrospinning and characterized. The scaffolds consisted of either a randomly oriented or an aligned structure of PLGA fibers. The mESCs were induced to differentiate into neuronal lineage and the effect of the polymer and fiber orientation on cell survival, morphology and differentiation efficiency was studied. The neural progenitors derived from the mESCs could survive and migrate onto the fibrous scaffolds. Aligned fibers provided more contact guidance with the neurites preferentially extending along the long axis of fiber. The mESCs differentiated into neural lineages expressing neural markers as seen by the immunocytochemistry. The nestin and beta3-tubulin expression was enhanced on the PLGA aligned fibers in comparison with the other groups, as seen by the quantitative analysis. Taken together, a combination of electrospun fiber scaffolds and mESC derived neural progenitor cells could provide valuable information about the effects of topology on neural differentiation and axonal regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1333-1345, 2017.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Ácido Láctico , Células-Tronco Embrionárias Murinas/metabolismo , Nanofibras/química , Células-Tronco Neurais/metabolismo , Ácido Poliglicólico , Alicerces Teciduais/química , Animais , Antígenos de Diferenciação/biossíntese , Ácido Láctico/química , Ácido Láctico/farmacologia , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Neurais/citologia , Ácido Poliglicólico/química , Ácido Poliglicólico/farmacologia , Copolímero de Ácido Poliláctico e Ácido PoliglicólicoRESUMO
Whereas highly porous scaffolds composed of electrospun nanofibers can mimick major features of the extracellular matrix in tissue engineering, they lack the ability to incorporate and release biocompounds (drugs, growth factors) safely in a controlled way. Here, electrospun core-shell fibers (core made from water and aqueous solutions of hydrophilic polymers and the shell from materials with well-defined release mechanisms) offer unique advantages in comparison with those that have helped make porous nanofibrillar scaffolds highly successful in tissue engineering. This review considers the preparation and biofunctionalization of such core-shell fibers as well as applications in various areas, including neural, vascular, cardiac, cartilage and bone tissue engineering, and touches on the topic of clinical trials.
Assuntos
Sistemas de Liberação de Medicamentos , Nanofibras , Engenharia Tecidual , Animais , Humanos , Nanotecnologia , Tecnologia FarmacêuticaRESUMO
Ethanol exposure to offspring during pregnancy and lactation leads to developmental disorders, including central nervous system dysfunction. In the present work, we have studied the effect of chronic ethanol exposure during pregnancy and lactation on the phosphorylating system associated with the astrocytic and neuronal intermediate filament (IF) proteins: glial fibrillary acidic protein (GFAP), and neurofilament (NF) subunits of low, medium, and high molecular weight (NFL, NFM, and NFH, respectively) in 9- and 21-day-old pups. Female rats were fed with 20% ethanol in their drinking water during pregnancy and lactation. The homeostasis of the IF phosphorylation was not altered in the cerebral cortex, cerebellum, or hippocampus of 9-day-old pups. However, GFAP, NFL, and NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. PKA had been activated in the hippocampus, and Ser55 in the N-terminal region of NFL was hyperphosphorylated. In addition, JNK/MAPK was activated and KSP repeats in the C-terminal region of NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. Decreased NFH immunocontent but an unaltered total NFH/phosphoNFH ratio suggested altered stoichiometry of NFs in the hippocampus of ethanol-exposed 21-day-old pups. In contrast to the high susceptibility of hippocampal cytoskeleton in developing rats, the homeostasis of the cytoskeleton of ethanol-fed adult females was not altered. Disruption of the cytoskeletal homeostasis in neural cells supports the view that regions of the brain are differentially vulnerable to alcohol insult during pregnancy and lactation, suggesting that modulation of JNK/MAPK and PKA signaling cascades target the hippocampal cytoskeleton in a window of vulnerability in 21-day-old pups. Our findings are relevant, since disruption of the cytoskeleton in immature hippocampus could contribute to later hippocampal damage associated with ethanol toxicity.
Assuntos
Depressores do Sistema Nervoso Central/toxicidade , Citoesqueleto/efeitos dos fármacos , Etanol/toxicidade , Hipocampo/efeitos dos fármacos , Lactação , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ingestão de Energia/efeitos dos fármacos , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/embriologia , Homeostase , Filamentos Intermediários/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Neurofilamentos/metabolismo , Fosforilação , Gravidez , Ratos , Ratos WistarRESUMO
Carbonyl compounds such as methylglyoxal (MGO) seem to play an important role in complications resulting from diabetes mellitus, in aging and neurodegenerative disorders. In this study, we are showing, that MGO is able to suppress cell viability and induce apoptosis in the cerebral cortex and hippocampus of neonatal rats ex-vivo. These effects are partially related with ROS production, evaluated by DCFH-DA assay. Coincubation of MGO and reduced glutathione (GSH) or Trolox (vitamin E) totally prevented ROS production but only partially prevented the MGO-induced decreased cell viability in the two brain structures, as evaluated by the MTT assay. Otherwise, L-NAME, a nitric oxide (NO) inhibitor, partially prevented ROS production in the two structures but partially prevented cytotoxicity in the hippocampus. Pharmacological inhibition of Erk, has totally attenuated MGO-induced ROS production and cytotoxicity, suggesting that MEK/Erk pathway could be upstream of ROS generation and cell survival. Otherwise, p38MAPK and JNK failed to prevent ROS generation but induced decreased cell survival consistent with ROS-independent mechanisms. We can propose that Erk, p38MAPK and JNK are involved in the cytotoxicity induced by MGO through different signaling pathways. While Erk could be an upstream effector of ROS generation, p38MAPK and JNK seem to be associated with ROS-independent cytotoxicity in neonatal rat brain. The cytotoxic damage progressed to apoptotic cell death at MGO concentration higher than those described for adult brain, suggesting that the neonatal brain is resistant to MGO-induced cell death. The consequences of MGO-induced brain damage early in life, remains to be clarified. However, it is feasible that high MGO levels during cortical and hippocampal development could be, at least in part, responsible for the impairment of cognitive functions in adulthood.