Characterization of renin mRNA expression and enzyme activity in rat and mouse mesangial cells

Renin is an enzyme involved in the stepwise generation of angiotensin II. Juxtaglomerular cells are the main source of plasma renin, but renin activity has been detected in other cell types. In the present study we evaluated the presence of renin mRNA in adult male Wistar rat and mouse (C-57 Black/6) mesangial cells (MC) and their ability to process, store and release both the active and inactive forms of the enzyme. Active renin and total renin content obtained after trypsin treatment were estimated by angiotensinogen consumption analyzed by SDS-PAGE electrophoresis and quantified by angiotensin I generation by HPLC. Renin mRNA, detected by RT-PCR, was present in both rat and mouse MC under basal conditions. Active renin was significantly higher (P<0.05) in the cell lysate (43.5 ± 5.7 ng h-1 10(6) cells) than in the culture medium (12.5 ± 2.5 ng h-1 10(6) cells). Inactive prorenin content was similar for the intra- and extracellular compartments (9.7 ± 3.1 and 3.9 ± 0.9 ng h-1 10(6) cells). Free active renin was the predominant form found in both cell compartments. These results indicate that MC in culture are able to synthesize and translate renin mRNA probably as inactive prorenin which is mostly processed to active renin inside the cell. MC secrete both forms of the enzyme but at a lower level compared with intracellular content, suggesting that the main role of renin synthesized by MC may be the intracellular generation of angiotensin II.

Kaarityypin ja suojakaasun vaikutus roiskeisuuteen teräksen MAG-hitsauksessa

Tässä kandidaatintyössä tutkitaan suojakaasun ja kaarityypin vaikutuksia roiskeisuuden muodostumiselle teräksen MAG-hitsauksessa (nro. 135). Roiskeisuuden tutkimisessa tutkitaan kolmea (3) eri kaarityyppiä ja kahta (2) eri suojakaasua ja niiden keskenäisiä vaikutuksia roiskeiden syntymiselle. Tutkittavat kaarityypit ovat pulssi-, kuumakaari sekä Kemppi Oy:n WiseFusion erikoiskaarisovellus. Suojakaasuina käyetään AGAn Corgon 3 ja Mison 18 suojakaasuja. Hitsauskokeita suoritetaan kuusi (6) kappaletta alapienana jalkoasennossa (PA). Työn alussa perehdytään MAG-hitsauksen laitteistoon ja teoriaan sekä perehdytään mitkä eri asiat vaikuttavat roiskeiden muodostumiseen. Työn lopussa verrataan tieteellisistä julkaisuista löydettyjä tietoja ja tuloksia itsetehtyihin koetuloksiin.

Anandamide injected into the lateral ventricle of the brain inhibits submandibular salivary secretion by attenuating parasympathetic neurotransmission

Our objective was to determine the effect of arachidonylethanolamide (anandamide, AEA) injected intracerebroventricularly (icv) into the lateral ventricle of the rat brain on submandibular gland (SMG) salivary secretion. Parasympathetic decentralization (PSD) produced by cutting the chorda tympani nerve strongly inhibited methacholine (MC)-induced salivary secretion while sympathetic denervation (SD) produced by removing the superior cervical ganglia reduced it slightly. Also, AEA (50 ng/5 µL, icv) significantly decreased MC-induced salivary secretion in intact rats (MC 1 µg/kg: control (C), 5.3 ± 0.6 vs AEA, 2.7 ± 0.6 mg; MC 3 µg/kg: C, 17.6 ± 1.0 vs AEA, 8.7 ± 0.9 mg; MC 10 µg/kg: C, 37.4 ± 1.2 vs AEA, 22.9 ± 2.6 mg). However, AEA did not alter the significantly reduced salivary secretion in rats with PSD, but decreased the slightly reduced salivary secretion in rats with SD (MC 1 µg/kg: C, 3.8 ± 0.8 vs AEA, 1.4 ± 0.6 mg; MC 3 µg/kg: C, 14.7 ± 2.4 vs AEA, 6.9 ± 1.2 mg; P < 0.05; MC 10 µg/kg: C, 39.5 ± 1.0 vs AEA, 22.3 ± 0.5 mg; P < 0.001). We showed that the inhibitory effect of AEA is mediated by cannabinoid type 1 CB1 receptors and involves GABAergic neurotransmission, since it was blocked by previous injection of the CB1 receptor antagonist AM251 (500 ng/5 µL, icv) or of the GABA A receptor antagonist, bicuculline (25 ng/5 µL, icv). Our results suggest that parasympathetic neurotransmission from the central nervous system to the SMG can be inhibited by endocannabinoid and GABAergic systems.

Stimulated mast cells promote maturation of myocardial microvascular endothelial cell neovessels by modulating the angiopoietin-Tie-2 signaling pathway

Angiopoietin (Ang)-1 and Ang-2 interact in angiogenesis to activate the Tie-2 receptor, which may be involved in new vessel maturation and regression. Mast cells (MCs) are also involved in formation of new blood vessels and angiogenesis. The present study was designed to test whether MCs can mediate angiogenesis in myocardial microvascular endothelial cells (MMVECs). Using a rat MMVEC and MC co-culture system, we observed that Ang-1 protein levels were very low even though its mRNA levels were increased by MCs. Interestingly, MCs were able to enhance migration, proliferation, and capillary-like tube formation, which were associated with suppressed Ang-2 protein expression, but not Tie-2 expression levels. These MCs induced effects that could be reversed by either tryptase inhibitor [N-tosyl-L-lysine chloromethyl ketone (TLCK)] or chymase inhibitor (N-tosyl-L-phenylalanyl chloromethyl ketone), with TLCK showing greater effects. In conclusion, our data indicated that MCs can interrupt neovessel maturation via suppression of the Ang-2/Tie-2 signaling pathway.

Determinação simultânea dos teores de cinza e proteína em farinha de trigo empregando NIRR-PLS e DRIFT-PLS

As técnicas de espectroscopia por reflexão no infravermelho próximo (NIRRS) e por reflexão difusa no infravermelho médio com transformada de Fourier (DRIFTS) foram empregadas com o método de regressão multivariado por mínimos quadrados parciais (PLS) para a determinação simultânea dos teores de proteína e cinza em amostras de farinha de trigo da variedade Triticum aestivum L. Foram coletados espectros no infravermelho em duplicata de 100 amostras, empregando-se acessórios de reflexão difusa. Os teores de proteína (8,85-13,23%) e cinza (0,330-1,287%), empregados como referência, foram determinados pelo método Kjeldhal e método gravimétrico, respectivamente. Os dados espectrais foram utilizados no formato log(1/R), bem como suas derivadas de primeira e segunda ordem, sendo pré-processados usando-se os dados centrados na média (MC) ou escalados pela variância (VS) ou ambos. Cinqüenta e cinco amostras foram usadas para calibração e 45 para validação dos modelos, adotando-se como critério de construção os valores mínimos do erro padrão de calibração (SEC) e do erro padrão de validação (SEV). Estes valores foram inferiores a 0,33% para proteína e a 0,07% para cinza. Os métodos desenvolvidos apresentam como vantagens a não agressão ao ambiente, bem como permitem uma determinação direta, simultânea, rápida e não destrutiva dos teores de proteína e cinza em amostras de farinha de trigo.

Caracterização termofísica de polpas de bacuri

Foram estudadas as propriedades termofísicas calor específico, massa específica, difusividade térmica e condutividade térmica de polpas de bacuri em diferentes concentrações. O calor específico foi determinado pelo método do calorímetro de mistura; a massa específica foi determinada em picnômetro; a difusividade térmica foi obtida utilizando-se o método do cilindro infinito; a condutividade térmica foi determinada a partir dos resultados experimentais obtidos para massa específica, calor específico e difusividade térmica. Todas as propriedades também foram estimadas teoricamente com o uso de equações propostas em literatura e por meio de regressões dependentes da concentração. Entre os resultados experimentais o calor específico situou-se entre 3,616 a 2,986 kJ/kgºC; a massa específica variou de 1.008,40 a 1.048,36 kg/m³; a difusividade térmica variou de 1,637x10-7 a 1,787x10-7 m²/s; a condutividade térmica variou de 0,50 a 0,64 W/mºC. Exceto a massa específica, o valor de todas as propriedades diminuiu com o aumento da concentração. A condutividade térmica foi melhor representada por equação do tipo exponencial. As demais propriedades foram bem ajustadas por equações do tipo quadrática.

Association between aflatoxin and aflatoxigenic fungi in Brazil nut (Bertholletia excelsa H.B.K.)

Brazil nut has a high nutritional content and is a very important trade commodity to some Latin American countries. In order to evaluate its safety, 120 samples from different stages of the productive chain were analyzed in terms of: moisture content (mc), aflatoxigenic fungi and aflatoxin (LOQ = 1.95 μg.kg-1 total aflatoxin) using TLC. Among all samples, 4 (6.7%) from the receiving area, and 5 (16.7%), from retail presented aflatoxins above the LOQ, but the amount of aflatoxins was below the LOQ after the samples were dried in the plant. The positive samples were above the limit of total aflatoxin permitted by the European Union (4.0 μg.kg-1) and Brazil (30 μg.kg-1). The mc mean was 22.43% in the receiving area, which is higher than that in the other stages samples. All the A. flavus strains were aflatoxigenic, and there was statistic association between the presence of aflatoxin and flavus strains. The aflatoxigenic fungi strains associated to the aflatoxins levels in the samples show that an effective control is necessary for the food safety in the Brazil nut production chain.

Identificação do potencial amilolítico de linhagens mutantes do fungo filamentoso Aspergillus nidulans

As amilases estão entre as mais importantes enzimas industriais, apresentando grande importância biotecnológica, principalmente na indústria alimentícia. Com o avanço no conhecimento das enzimas, a utilização dos fungos como fonte de enzimas vem adquirindo um status de destaque nas mais variadas áreas industriais e comerciais. Diante disso, o presente estudo procurou identificar a presença de atividade amilolítica em quatro linhagens do fungo filamentoso Aspergillus nidulans, selvagem, PAT, biA1methG1 e CLB3, utilizando dois meios distintos de cultura, BDA e Meio Completo a 2% amido, variando os tratamentos com adição ou não de glicose. Foram determinados o diâmetro médio da colônia, o diâmetro médio do halo e o Índice Enzimático. Como resultados, todas as linhagens testadas foram capazes de degradar o amido quando na ausência de glicose, porém o tratamento que obteve estatisticamente melhor crescimento e maior degradação do amido foi o MC sem glicose a 2% amido e a linhagem que se demonstrou potencialmente degradadora de amido foi o mutante CLB3. Conclui-se, portanto, que Aspergillus nidulans pode ser considerado como um produtor de amilases.

Brazil nut sorting for aflatoxin prevention: a comparison between automatic and manual shelling methods

The impact of automatic and manual shelling methods during manual/visual sorting of different batches of Brazil nuts from the 2010 and 2011 harvests was evaluated in order to investigate aflatoxin prevention.The samples were tested as follows: in-shell, shell, shelled, and pieces in order to evaluate the moisture content (mc), water activity (Aw), and total aflatoxin (LOD = 0.3 µg/kg and LOQ 0.85 µg/kg) at the Brazil nut processing plant. The results of aflatoxins obtained for the manually shelled nut samples ranged from 3.0 to 60.3 µg/g and from 2.0 to 31.0 µg/g for the automatically shelled samples. All samples showed levels of mc below the limit of 15%; on the other hand, shelled samples from both harvests showed levels of Aw above the limit. There were no significant differences concerning the manual or automatic shelling results during the sorting stages. On the other hand, the visual sorting was effective in decreasing the aflatoxin contamination in both methods.

Effect of huitlacoche (Ustilago maydis DC Corda) paste addition on functional, chemical and textural properties of tortilla chips

AbstractThis study analyzed the addition of huitlacoche paste (HP) in baked tortilla chips (TC), evaluating its effects on functional, physicochemical and structural changes during processing. Two blue corn grains were nixtamalized, stone milled, air dried and milled to obtain flour; commercial blue corn flour (TM1) and commercial TC (TM2) were used as controls. Additions of 0, 3, 6 and 9% of HP were formulated; masas were prepared at 55% moisture content (MC), precooked and baked in an industrial machine. TC crispiness was influenced by grain characteristics and percentage of HP. Huitlacoche paste addition caused an increase in total dietary fiber (from 5.27 to 14.54%), total soluble phenolics content (from 17.52 to 37.60 mg GAE/100 g) and antioxidant capacity (from 6.74 to 7.98 μmol TE/g) in TC. Results suggest that tortilla chips added with huitlacoche can be an alternative to prepare this traditional edible fungus and produce healthier snacks, not fried and enriched with bioactive compounds.

The effect of hypoxia and reoxygenation in the response of mesangial cells to angiotensin II in vitro

INTRODUCTION: Mesangial cells (MC) may be involved in the glomerular alterations induced by ischemia/reperfusion injury. OBJECTIVE: To evaluate the response of immortalized MC (IMC) to 30 minutes of hypoxia followed by reoxygenation periods of 30 minutes (H/R30) or 24 hours (H/R24). METHODS: The intracellular calcium concentration ([Ca+2]i) was measured before (baseline) and after adding angiotensin II (AII, 10-5 M) in the presence and absence of glybenclamide (K ATP channel blocker). We estimated the level of intracellular ATP, nitric oxide (NO) and PGE2. RESULTS: ATP concentration decreased after hypoxia and increased after reoxygenation. Hypoxia and H/R induced increases in basal [Ca+2]i. AII induced increases in [Ca+2]i in normoxia (97 ± 9%), hypoxia (72 ± 10%) or HR30 (85 ± 17%) groups, but there was a decrease in the response to AII in group H/R24 since the elevation in [Ca+2]i was significantly lower than in control (61 ± 10%, p < 0.05). Glybenclamide did not modify this response. It was observed a significant increase in NO generation after 24 hours of reoxygenation, but no difference in PGE2 production was observed. Data suggest that H/R injury is characterized by increased basal [Ca+2]i and by an impairment in the response of cells to AII. Results suggest that the relative insensibility to AII may be at least in part mediated by NO but not by prostaglandins or vasodilator K ATP channels. CONCLUSION: H/R caused dysfunction in IMC characterized by increases in basal [Ca+2]i during hypoxia and reduction in the functional response to AII during reoxygenation.

Simulation and material calibration of ultra high strength steel (UHSS) S960 welded joint under static tensile test utilizing finite element method (FEM)

The aim of this work was to calibrate the material properties including strength and strain values for different material zones of ultra-high strength steel (UHSS) welded joints under monotonic static loading. The UHSS is heat sensitive and softens by heat due to welding, the affected zone is heat affected zone (HAZ). In this regard, cylindrical specimens were cut out from welded joints of Strenx® 960 MC and Strenx® Tube 960 MH, were examined by tensile test. The hardness values of specimens’ cross section were measured. Using correlations between hardness and strength, initial material properties were obtained. The same size specimen with different zones of material same as real specimen were created and defined in finite element method (FEM) software with commercial brand Abaqus 6.14-1. The loading and boundary conditions were defined considering tensile test values. Using initial material properties made of hardness-strength correlations (true stress-strain values) as Abaqus main input, FEM is utilized to simulate the tensile test process. By comparing FEM Abaqus results with measured results of tensile test, initial material properties will be revised and reused as software input to be fully calibrated in such a way that FEM results and tensile test results deviate minimum. Two type of different S960 were used including 960 MC plates, and structural hollow section 960 MH X-joint. The joint is welded by BöhlerTM X96 filler material. In welded joints, typically the following zones appear: Weld (WEL), Heat affected zone (HAZ) coarse grained (HCG) and fine grained (HFG), annealed zone, and base material (BaM). Results showed that: The HAZ zone is softened due to heat input while welding. For all the specimens, the softened zone’s strength is decreased and makes it a weakest zone where fracture happens while loading. Stress concentration of a notched specimen can represent the properties of notched zone. The load-displacement diagram from FEM modeling matches with the experiments by the calibrated material properties by compromising two correlations of hardness and strength.

Capacidade cognitiva de indivíduos com doença renal crônica: relação com características demográficas e clínicas

Introdução: O comprometimento da cognição e memória (CM) é comum em indivíduos com Doença Renal Crônica (DRC) em hemodiálise, o que prejudica a aderência ao tratamento. Objetivo: Avaliar a capacidade cognitiva de indivíduos renais crônicos em hemodiálise por meio do Miniexame do Estado Mental (MEEM) e a relação com as características sociodemográficas e clínicas desses indivíduos. Métodos: Foram obtidas informações clínicas e sociodemográficas de 75 indivíduos. Para avaliação da MC, foi aplicado o MEEM, o qual foi analisado segundo os diversos pontos de corte propostos na literatura. Após classificar os participantes de acordo com as diferentes propostas e pelas causas da DRC, os indivíduos foram alocados em grupos com e sem comprometimento da CM, na tentativa de identificar diferenças entre eles. Resultados: A maioria dos participantes eram homens, com idade média de 59,2 anos. O escore médio do MEEM foi 24,16 pontos e não houve diferença (p < 0,05) quanto às diferentes causas da DRC. Os escores do MEEM se correlacionaram (p < 0,05) positivamente com os anos de escolaridade e renda per capita e inversamente com a idade. Segundo os diversos pontos de corte, seis a 34 participantes apresentaram comprometimento da CM e apenas três desses foram classificados com déficit de CM por todas as propostas avaliadas. Conclusão: O escore do MEEM reduziu com o aumento da idade e se elevou com os anos de estudo e com a renda per capita. Não foram encontradas relações que justificassem efeitos prejudiciais do processo dialítico sobre a CM.

Seed moisture range in a soybean plant

It is common to see in any soybean plant that seeds reach maturity at different times. Thus the objective of the present study was to determine the magnitude of the seed moisture range at different stages of maturation in a soybean plant. The field study was conducted in a tropical region in the state of Mato Grosso - Brazil, established with foundation seeds of the MTBR-45 cultivar, and at flowering, 100 plants were marked at the same maturity stage. Harvesting began when seeds still were at high moisture content (MC). At each of eight harvesting times, during 16 days, all pods from two plants were harvested and the seeds from each pod were hand threshed individually and determined the moisture content . The results revealed that there is a great distribution of seed MC in a soybean plant, where at physiological maturity, the magnitude can reach more than 30 percentage points. Also, even with an average MC below 12%, there were more than 20 % of the seeds with MC above 13% and some seeds at this point had been waiting to be harvested for more than a week. The following conclusions and/or recommendations can be taken: 1- The great seed MC range in a soybean seed lot harvested at field maturity leads to the presence of seeds susceptible to mechanical damage and with MC unsafe for adequate storage; 2 - It is recommended that harvesting be accomplished when the seeds are in the 15-18% MC range, in order to minimize field deterioration and the percentage of seeds with high MC; 3- Drying is recommended, even when soybean seeds are in their average MC safe for storage.

Effects of Fabrication Processes on the Behavior of S960 Ultra High Strength Steel (UHSS)

Strenx® 960 MC is a direct quenched type of Ultra High Strength Steel (UHSS) with low carbon content. Although this material combines high strength and good ductility, it is highly sensitive towards fabrication processes. The presence of stress concentration due to structural discontinuity or notch will highlight the role of these fabrication effects on the deformation capacity of the material. Due to this, a series of tensile tests are done on both pure base material (BM) and when it has been subjected to Heat Input (HI) and Cold Forming (CF). The surface of the material was dressed by laser beam with a certain speed to study the effect of HI while the CF is done by bending the specimen to a certain angle prior to tensile test. The generated results illustrate the impact of these processes on the deformation capacity of the material, specially, when the material has HI experience due to welding or similar processes. In order to compare the results with those of numerical simulation, LS-DYNA explicit commercial package has been utilized. The generated results show an acceptable agreement between experimental and numerical simulation outcomes.