Gastroprotective effects of oral nucleotide administration

BACKGROUND AND AIMS: Nucleotides form the building blocks of DNA and are marketed as dietary supplements, alone or in combination with other ingredients, to promote general health. However, there has been only limited scientific study regarding the true biological activity of orally administered nucleotides. We therefore tested their efficacy in a variety of models of epithelial injury and repair. METHODS: Effects on proliferation ([(3)H] thymidine incorporation) and restitution (cell migration of wounded monolayers) were analysed using HT29 and IEC6 cells. The ability of a nucleotide mixture to influence gastric injury when administered orally and subcutaneously was analysed using a rat indomethacin (20 mg/kg) restraint model. RESULTS: In both cell lines, cell migration was increased by approximately twofold when added at 1 mg/ml (p<0.01); synergistic responses were seen when a mixture of nucleotides was used. Cell proliferation was stimulated by adenosine monophosphate (AMP) in HT29, but not in IEC6, cells. Gastric injury was reduced by approximately 60% when gavaged at 4–16 mg/ml (p<0.05), concentrations similar to those likely to be found in consumers taking nucleotide supplements. Systemic administration of nucleotides was unhelpful. CONCLUSIONS: Nucleotides possess biological activity when analysed in a variety of models of injury and repair and could provide a novel inexpensive approach for the prevention and treatment of the injurious effects of non steroidal anti‐inflammatory drugs and other ulcerative conditions of the bowel. Further studies on their potential benefits (and risks) appear justified

Penurunan Viabilitas Benih Padi (Oryza Sativa L.) melalui Beberapa Metode Pengusangan Cepat

Availability of seed lots with different viabilities is very important as the material for invigoration studies. Acceleratedor rapid aging methods is expected to serve seeds with different viabilities for those studies. The objective of this study was toobtain efficient seeds rapid aging method of rice seeds. The study consisted of three experiments i.e. rapid aging with ethanolgas, soaking seed in liquid ethanol (96%) and exposing seeds to 41 oC temperature and ± 100% relative humidity. Eachexperiment was arranged in a randomized block design with single factor that was length of aging with three replications.There were eight rice varieties used in this study, i. e. three varieties of upland rice, two verieties of lowland rice, and threevarieties of swamp rice. The results showed that the physical aging method could not produce reliable data due to fungusinfection on the treated seed. It was found that generally 60% and 50% viabilities of rice seed could be obtain by ethanol gastreatment for 4.9 and 5.3 hours, as well as by liquid ethanol for 4.0 and 4.4 minutes, respectively. Rapid aging method withliquid ethanol was the fastest and simplest method for decreasing seed viability of rice

A prática na construção da identidad profissional: estudo exploratório junto de educadores de infância

[Resumo] De acordo com Katz (1993) os educadores de infáncia podem percorrer 4 estádios no seu desenvolvimento profissional: sobrevivencia, consolida~ao, renova~ao e maturidade. A prática profissional parece ser o factor determinante dessa progressao sucessiva, sobretudo tendo como variáveis moderadoras as experiencias vivenciadas de feedback, de suporte e de reflexao (Bell & Gilbert, 1996). Iniciando um projecto de investiga~ao junto de educadores de infancia neste tema, apresentamse os dados de um estudo qualitativo realizado junto de 5 alunas finalistas e de 5 educadoras de infáncia (com 3 ou mais anos de experiencia profissional). Este estudo fez urna opçao por urna metodologia qualitativa (análise de conteúdo), tendo-nos servido de urna entrevista semi-estruturada para a recolha dos dados. A entrevista estruturou-se em torno dos seguintes aspectos: "ser educador", planos de actividades, materiais, e relaçes interpessoais. A comunicaçao apresenta e discute as proximidades e diferenzas de discurso nos dois grupos considerados, apreciando ainda as potencialidades da metodologia seguida para os objectivos deste projecto

Mkp3 is a negative feedback modulator of Fgf8 signaling in the mammalian isthmic organizer

The pivotal mechanisms that govern the correct patterning and regionalization of the distinct areas of the mammalian CNS are driven by key molecules that emanate from the so-called secondary organizers at neural plate and tube stages. FGF8 is the candidate morphogenetic molecule to pattern the mesencephalon and rhombencephalon in the isthmic organizer (IsO). Recognizable relevance has been given to the intracellular pathways by which Fgf8 is regulated and modulated. In chick limb bud development, a dual mitogen-activated protein kinase phosphatase-3 (Mkp3) plays a role as a negative feedback modulator of Fgf8 signaling. We have investigated the role of Mkp3 and its functional relationship with the Fgf8 signaling pathway in the mouse IsO using gene transfer microelectroporation assays and protein-soaked bead experiments. Here, we demonstrate that MKP3 has a negative feedback action on the MAPK/ERK-mediated FGF8 pathway in the mouse neuroepithelium. (C) 2004 Elsevier Inc. All rights reserved.info:eu-repo/semantics/publishedVersio

Gluconic acid production by Aspergillus niger from sugarcane molasses and grape must: effect of increased air pressure and operation mode

Feedstock costs for the biosynthesis of gluconic acid (GA) represent most of the operating costs at an industrial scale. The increasing demand for GA boosts the search for alternative substrates to pure glucose. The oxidation reaction of glucose to GA, catalyzed by glucose oxidase, is strongly dependent on oxygen availability in the culture medium. The high viscous Aspergillus niger culture, together with the use of agro-industrial by-products rich in sugars, could be a challenge in the biotechnological production of GA. This work showed the strong effect of air pressurized at 4 bar on batch and step-wise fed-batch production of GA by A. niger MUM 92.13 from sugarcane molasses and grape must. A 3-fold enhancement in GA productivity was obtained in batch experiments at 4 bar compared to those at atmospheric pressure. Moreover, step-wise fed-batch cultures carried out at 4 bar showed to be an alternative to traditional batch strategies, with similar GA yields. This study demonstrates the possibility of replacing pure glucose with two different sugar-rich by-products in the microbial production of GA under pressurized air conditions, becoming its production more sustainable and eco-friendlier within a circular bioeconomy concept.Portuguese Foundation for Science and Technology (FCT) - UID/BIO/04469/2019 and the PhD grant SFRH/BD/129475/2017.info:eu-repo/semantics/publishedVersio

On correctly assessing the reversibility of the magnetocaloric effect from indirect measurements

The adiabatic temperature change ($\Delta T_{ad}$) of a magnetic refrigerant can be indirectly estimated through field ($H$) and temperature ($T$) dependent magnetization ($M$) and specific heat ($C_p$) measurements. A direct integration approach for this estimation is frequently reported, which is an approximation to a rigorous mathematical approach. In this work, we propose an iterative method in small $H$ steps, to estimate $\Delta T_{ad}$ from indirect measurements. We show that this approach is able to reproduce the reversibility of the magnetocaloric effect, and provides a more accurate estimation of $\Delta T_{ad}$, up to 10\% when considering a detailed $M(H,T)$ and $Cp(H,T)$ dataset that reproduces the magnetothermal properties of gadolinium, a benchmark room-temperature magnetic refrigerant

Yarrowia lipolytica is a promising oleaginous yeast for bio-oils production from volatile fatty acids

Every year, approximately 931 million tons of food waste (FW) are generated worldwide. The discharge of FW in the landfill has a negative environmental impact due to water and soil pollution and GHG emission. Volatile fatty acids (VFAs), produced by anaerobic fermentation of FW, can be used as a substrate by oleaginous yeasts to produce bio-oils. The bioconversion of pure VFAs into Y. lipolytica biomass and bio-oils was affected by oxygenation conditions in batch cultures carried out in a stirred-tank bioreactor. Approximately 3-fold enhancement in lipids concentration was obtained by increasing the agitation and aeration rates. Two-stage batch cultures (1st stage growth in glucose; 2nd stage bio-oils production in VFAs) proved to be an effective approach to improve lipids accumulation from pure VFAs. The highest lipid content was attained in conditions of dissolved oxygen concentration of 45% of saturation during the lipogenic phase. Y. lipolytica also accumulated lipids in food waste-derived VFAs, particularly in two-stage batch cultures (1st stage growth in VFAs; 2nd stage bio-oils production in crude glycerol). These bio-oils are promising feedstock for the biodiesel industry and the estimated fuel properties of biodiesel are in accordance with international standards.info:eu-repo/semantics/publishedVersio

Optimization study of Escherichia coli TB1 cell disruption for cytochrome b5 recovery in a small-scale bead mill

The recovery of a recombinant intracellular protein, cytochrome b5, from Escherichia coli TB1 cells was carried out by bead mill disintegration in a discontinuous smallscale instrument. This process was optimized by the use of experimental factorial design. Several parameters were studied: operating time, amount and size of beads, cellular suspension concentration, and presence of toluene and lysozyme. For the experimental conditions used, only the time of treatment and bead load had significant effects. The optimal values of these variables were found by applying the response surface methodology.Junta Nacional de Investigação Científica e Tecnológica (JNICT

Freeze/thawing and sonication of Escherichia coli TB1 cells for cytochrome b5 recovery

The influence of sonication power, suspension volume and cell concentration on the kinetics of cytochrome b5 and intracellular protein release by sonication of Escherichia coli TB1 cells was studied. The influence of freezing and thawing of the cell suspension was also evaluated. Freezing and thawing increased the recovery yield of cytochrome b5. The sonication efficiency increased with the increase of sonication power and with the decrease of the suspension volume and cell concentration