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Sample records for extracellular da concentration

  1. Stimulation of Suicidal Erythrocyte Death by Increased Extracellular Phosphate Concentrations

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    Jakob Voelkl

    2014-02-01

    Full Text Available Background/Aim: Anemia in renal insufficiency results in part from impaired erythrocyte formation due to erythropoietin and iron deficiency. Beyond that, renal insufficiency enhances eryptosis, the suicidal erythrocyte death characterized by phosphatidylserine-exposure at the erythrocyte surface. Eryptosis may be stimulated by increase of cytosolic Ca2+-activity ([Ca2+]i. Several uremic toxins have previously been shown to stimulate eryptosis. Renal insufficiency is further paralleled by increase of plasma phosphate concentration. The present study thus explored the effect of phosphate on erythrocyte death. Methods: Cell volume was estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, and [Ca2+]i from Fluo3-fluorescence. Results: Following a 48 hours incubation, the percentage of phosphatidylserine exposing erythrocytes markedly increased as a function of extracellular phosphate concentration (from 0-5 mM. The exposure to 2 mM or 5 mM phosphate was followed by slight but significant hemolysis. [Ca2+]i did not change significantly up to 2 mM phosphate but significantly decreased at 5 mM phosphate. The effect of 2 mM phosphate on phosphatidylserine exposure was significantly augmented by increase of extracellular Ca2+ to 1.7 mM, and significantly blunted by nominal absence of extracellular Ca2+, by additional presence of pyrophosphate as well as by presence of p38 inhibitor SB203580. Conclusion: Increasing phosphate concentration stimulates erythrocyte membrane scrambling, an effect depending on extracellular but not intracellular Ca2+ concentration. It is hypothesized that suicidal erythrocyte death is triggered by complexed CaHPO4.

  2. Lowering extracellular chloride concentration alters outer hair cell shape.

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    Cecola, R P; Bobbin, R P

    1992-08-01

    In general, increasing external K+ concentration, as well as exposure to hypotonic medium, induces a shortening of outer hair cells (OHCs) accompanied by an increase in width and volume. One possible mechanism suggested for these changes is a movement of Cl- and/or water across the cell membrane. We therefore examined the role of Cl- in OHC volume maintenance by testing the effect of decreasing extracellular Cl- concentration on OHC length and shape. In addition, the effect of hypotonic medium was examined. OHCs were isolated from guinea pig cochleae, mechanically dissociated and dispersed, and placed in a modified Hanks balanced salt solution (HBS). Exposing the cells to a Cl(-)-free HBS produced an initial shortening, which was rapidly followed by an increase in length. After about 9 min of exposure to Cl(-)-free HBS, the cells appeared to lose all water and collapsed. Upon return to normal HBS, the OHCs returned to their normal shape. We speculate that the collapse of the OHCs may be due to the loss of intracellular Cl-, which, in turn, resulted in the loss of intracellular K+ and water. The results indicate that Cl- contributes greatly to the maintenance of OHC volume. In addition, we confirmed that isolated OHCs swell in hypotonic medium and maintain their swollen state until returned to normal medium. The mechanism for maintenance of the swollen state is unknown.

  3. GLUCOSE-CONCENTRATION IN SUBCUTANEOUS EXTRACELLULAR-SPACE

    NARCIS (Netherlands)

    SCHMIDT, FJ; SLUITER, WJ; SCHOONEN, AJM

    1993-01-01

    OBJECTIVE- To compare the subcutaneous glucose sensor measurements with two reference methods. Previous studies provide conflicting findings about the real glucose concentrations in subcutaneous tissue. Some suggest substantially lower concentration, whereas others measure proportionally higher gluc

  4. Brain intra- and extracellular sodium concentration in multiple sclerosis: a 7 T MRI study.

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    Petracca, Maria; Vancea, Roxana O; Fleysher, Lazar; Jonkman, Laura E; Oesingmann, Niels; Inglese, Matilde

    2016-03-01

    Intra-axonal accumulation of sodium ions is one of the key mechanisms of delayed neuro-axonal degeneration that contributes to disability accrual in multiple sclerosis. In vivo sodium magnetic resonance imaging studies have demonstrated an increase of brain total sodium concentration in patients with multiple sclerosis, especially in patients with greater disability. However, total sodium concentration is a weighted average of intra- and extra-cellular sodium concentration whose changes reflect different tissue pathophysiological processes. The in vivo, non-invasive measurement of intracellular sodium concentration is quite challenging and the few applications in patients with neurological diseases are limited to case reports and qualitative assessments. In the present study we provide first evidence of the feasibility of triple quantum filtered (23)Na magnetic resonance imaging at 7 T, and provide in vivo quantification of global and regional brain intra- and extra-cellular sodium concentration in 19 relapsing-remitting multiple sclerosis patients and 17 heathy controls. Global grey matter and white matter total sodium concentration (respectively P brain regional level, clusters of increased total sodium concentration and intracellular sodium concentration and decreased intracellular sodium volume fraction were found in several cortical, subcortical and white matter regions when patients were compared with healthy controls (P < 0.05 family-wise error corrected for total sodium concentration, P < 0.05 uncorrected for multiple comparisons for intracellular sodium concentration and intracellular sodium volume fraction). Measures of total sodium concentration and intracellular sodium volume fraction, but not measures of intracellular sodium concentration were correlated with T2-weighted and T1-weighted lesion volumes (0.05 < P < 0.01) and with Expanded Disability Status Scale (P < 0.05). Thus, suggesting that while intracellular sodium volume fraction decrease could

  5. The effect of morphine sensitization on extracellular concentrations of GABA in dorsal hippocampus of male rats.

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    Farahmandfar, Maryam; Zarrindast, Mohammad-Reza; Kadivar, Mehdi; Karimian, Seyed Morteza; Naghdi, Nasser

    2011-11-01

    Repeated, intermittent exposure to drugs of abuse, such as morphine results in response enhancements to subsequent drug treatments, a phenomenon referred to as behavioral sensitization. As persistent neuronal sensitization may contribute to the long-lasting consequences of drug abuse, characterizing the neurochemical mechanisms of sensitization is providing insights into addiction. Although it has been shown that GABAergic systems in the CA1 region of dorsal hippocampus are involved in morphine sensitization, the alteration of extracellular level of GABA in this area in morphine sensitization has not been investigated. In the present study, using the in vivo microdialysis technique, we investigated the effect of morphine sensitization on extracellular GABA concentration in CA1 region of dorsal hippocampus of freely moving rats. Sensitization was induced by subcutaneous (s.c.) injection of morphine, once daily for 3 days followed by 5 days free of the opioid treatment. The results showed that extracellular GABA concentration in CA1 was decreased following acute administration of morphine in non-sensitized rats. However, morphine-induced behavioral sensitization significantly increased the extracellular GABA concentration in this area. The enhancement of GABA in morphine sensitized rats was inhibited by administration of naloxone 30 min before each of three daily doses of morphine. These results suggest an adaptation of the GABAergic neuronal transmission in dorsal hippocampus induced by morphine sensitization and it is implied that opioid receptors may play an important role in this effect.

  6. Extracellular ATP inhibits root gravitropism at concentrations that inhibit polar auxin transport

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    Tang, Wenqiang; Brady, Shari R.; Sun, Yu; Muday, Gloria K.; Roux, Stanley J.

    2003-01-01

    Raising the level of extracellular ATP to mM concentrations similar to those found inside cells can block gravitropism of Arabidopsis roots. When plants are grown in Murashige and Skoog medium supplied with 1 mM ATP, their roots grow horizontally instead of growing straight down. Medium with 2 mM ATP induces root curling, and 3 mM ATP stimulates lateral root growth. When plants are transferred to medium containing exogenous ATP, the gravity response is reduced or in some cases completely blocked by ATP. Equivalent concentrations of ADP or inorganic phosphate have slight but usually statistically insignificant effects, suggesting the specificity of ATP in these responses. The ATP effects may be attributable to the disturbance of auxin distribution in roots by exogenously applied ATP, because extracellular ATP can alter the pattern of auxin-induced gene expression in DR5-beta-glucuronidase transgenic plants and increase the response sensitivity of plant roots to exogenously added auxin. The presence of extracellular ATP also decreases basipetal auxin transport in a dose-dependent fashion in both maize (Zea mays) and Arabidopsis roots and increases the retention of [(3)H]indole-3-acetic acid in root tips of maize. Taken together, these results suggest that the inhibitory effects of extracellular ATP on auxin distribution may happen at the level of auxin export. The potential role of the trans-plasma membrane ATP gradient in auxin export and plant root gravitropism is discussed.

  7. Nitric oxide inhibited the melanophore aggregation induced by extracellular calcium concentration in snakehead fish, Channa punctatus.

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    Biswas, Saikat P; Palande, Nikhil V; Jadhao, Arun G

    2011-12-01

    We studied the role of nitric oxide (NO) and extra-cellular Ca(2+) on the melanophores in Indian snakehead teleost, Channa punctatus. Increase of Ca(2+) level in the external medium causes pigment aggregation in melanophores. This pigment-aggregating effect was found to be inhibited when the external medium contained spontaneous NO donor, sodium nitro prusside (SNP) at all the levels of concentration tested. Furthermore, it has been observed that SNP keeps the pigment in dispersed state even after increasing the amount of Ca(2+). In order to test whether NO donor SNP causes dispersion of pigments or not is checked by adding the inhibitor of nitric oxide synthase, N-omega-Nitro-L-arginine (L-NNA) in the medium. It has been noted that the inhibitor L-NNA blocked the effect of NO donor SNP causing aggregation of pigments. In that way NO is inhibiting the effect of extracellular Ca(2+), keeping the pigment dispersed.

  8. A standardized method to determine the concentration of extracellular vesicles using tunable resistive pulse sensing

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    Robert Vogel

    2016-09-01

    Full Text Available Background: Understanding the pathogenic role of extracellular vesicles (EVs in disease and their potential diagnostic and therapeutic utility is extremely reliant on in-depth quantification, measurement and identification of EV sub-populations. Quantification of EVs has presented several challenges, predominantly due to the small size of vesicles such as exosomes and the availability of various technologies to measure nanosized particles, each technology having its own limitations. Materials and Methods: A standardized methodology to measure the concentration of extracellular vesicles (EVs has been developed and tested. The method is based on measuring the EV concentration as a function of a defined size range. Blood plasma EVs are isolated and purified using size exclusion columns (qEV and consecutively measured with tunable resistive pulse sensing (TRPS. Six independent research groups measured liposome and EV samples with the aim to evaluate the developed methodology. Each group measured identical samples using up to 5 nanopores with 3 repeat measurements per pore. Descriptive statistics and unsupervised multivariate data analysis with principal component analysis (PCA were used to evaluate reproducibility across the groups and to explore and visualise possible patterns and outliers in EV and liposome data sets. Results: PCA revealed good reproducibility within and between laboratories, with few minor outlying samples. Measured mean liposome (not filtered with qEV and EV (filtered with qEV concentrations had coefficients of variance of 23.9% and 52.5%, respectively. The increased variance of the EV concentration measurements could be attributed to the use of qEVs and the polydisperse nature of EVs. Conclusion: The results of this study demonstrate the feasibility of this standardized methodology to facilitate comparable and reproducible EV concentration measurements.

  9. Mechanisms of astrocytic K(+) clearance and swelling under high extracellular K(+) concentrations.

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    Murakami, Shingo; Kurachi, Yoshihisa

    2016-03-01

    In response to the elevation of extracellular K(+) concentration ([K(+)]out), astrocytes clear excessive K(+) to maintain conditions necessary for neural activity. K(+) clearance in astrocytes occurs via two processes: K(+) uptake and K(+) spatial buffering. High [K(+)]out also induces swelling in astrocytes, leading to edema and cell death in the brain. Despite the importance of astrocytic K(+) clearance and swelling, the underlying mechanisms remain unclear. Here, we report results from a simulation analysis of astrocytic K(+) clearance and swelling. Astrocyte models were constructed by incorporating various mechanisms such as intra/extracellular ion concentrations of Na(+), K(+), and Cl(-), cell volume, and models of Na,K-ATPase, Na-K-Cl cotransporter (NKCC), K-Cl cotransporter, inwardly-rectifying K(+) (KIR) channel, passive Cl(-) current, and aquaporin channel. The simulated response of astrocyte models under the uniform distribution of high [K(+)]out revealed significant contributions of NKCC and Na,K-ATPase to increases of intracellular K(+) and Cl(-) concentrations, and swelling. Moreover, we found that, under the non-uniform distribution of high [K(+)]out, KIR channels localized at synaptic clefts absorbed excess K(+) by depolarizing the equivalent potential of K(+) (E K) above membrane potential, while K(+) released through perivascular KIR channels was enhanced by hyperpolarizing E K and depolarizing membrane potential. Further analysis of simulated drug effects revealed that astrocyte swelling was modulated by blocking each of the ion channels and transporters. Our simulation analysis revealed controversial mechanisms of astrocytic K(+) clearance and swelling resulting from complex interactions among ion channels and transporters.

  10. Basic mechanism leading to stimulation of glycogenolysis by isoproterenol, EGF, elevated extracellular K+ concentrations, or GABA.

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    Xu, Junnan; Song, Dan; Bai, Qiufang; Cai, Liping; Hertz, Leif; Peng, Liang

    2014-04-01

    Glycogenolysis, in brain parenchyma an astrocyte-specific process, has changed from being envisaged as an emergency procedure to playing central roles during brain response to whisker stimulation, memory formation, astrocytic K(+) uptake and stimulated release of ATP. It is activated by several transmitters and by even very small increases in extracellular K(+) concentration, and to be critically dependent upon an increase in free cytosolic Ca(2+) concentration ([Ca(2+)]i), whereas cAMP plays only a facilitatory role together with increased [Ca(2+)]i. Detailed knowledge about the signaling pathways eliciting glycogenolysis is therefore of interest and was investigated in the present study in well differentiated cultures of mouse astrocytes. The β-adrenergic agonist isoproterenol stimulated glycogenolysis by a β1-adrenergic effect, which initiated a pathway in which cAMP/protein kinase A activated a Gi/Gs shift, leading to Ca(2+)-activated glycogenolysis. Inhibition of this pathway downstream of cAMP but upstream of the Gi/Gs shift abolished the glycogenolysis. However, inhibitors operating downstream of the Ca(2+)-sensitive step, but preventing transactivation-mediated epidermal growth factor (EGF) receptor stimulation, a later step in the activated pathway, also caused inhibition of glycogenolysis. For this reason the effect of EGF was investigated and it was found to be glycogenolytic. Large increases in extracellular K(+) activated glycogenolysis by a nifedipine-inhibited L-channel opening allowing influx of Ca(2+), known to be glycogenolysis-dependent. Small increases (addition of 5 mM KCl) caused a smaller effect by a similarly glycogenolysis-reliant opening of an IP3 receptor-dependent ouabain signaling pathway. The same pathway could be activated by GABA (also in brain slices) due to its depolarizing effect in astrocytes.

  11. Reproducible extracellular vesicle size and concentration determination with tunable resistive pulse sensing

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    Frank A. W. Coumans

    2014-12-01

    Full Text Available Introduction: The size of extracellular vesicles (EVs can be determined with a tunable resistive pulse sensor (TRPS. Because the sensing pore diameter varies from pore to pore, the minimum detectable diameter also varies. The aim of this study is to determine and improve the reproducibility of TRPS measurements. Methods: Experiments were performed with the qNano system (Izon using beads and a standard urine vesicle sample. With a combination of voltage and stretch that yields a high blockade height, we investigate whether the minimum detected diameter is more reproducible when we configure the instrument targeting (a fixed stretch and voltage, or (b fixed blockade height. Results: Daily measurements with a fixed stretch and voltage (n=102 on a standard urine sample show a minimum detected vesicle diameter of 128±19 nm [mean±standard deviation; coefficient of variation (CV 14.8%]. The vesicle concentration was 2.4·109±3.8·109 vesicles/mL (range 1.4·108–1.8·1010. When we compared setting a fixed stretch and voltage to setting a fixed blockade height on 3 different pores, we found a minimum detected vesicle diameter of 118 nm (CV 15.5%, stretch, and 123 nm (CV 4.5%, blockade height. The detected vesicle concentration was 3.2–8.2·108 vesicles/mL with fixed stretch and 6.4–7.8·108 vesicles/mL with fixed blockade height. Summary/conclusion: Pore-to-pore variability is the cause of the variation in minimum detected size when setting a fixed stretch and voltage. The reproducibility of the minimum detectable diameter is much improved by setting a fixed blockade height.

  12. The concentration of extracellular superoxide dismutase in plasma is maintained by LRP-mediated endocytosis

    DEFF Research Database (Denmark)

    Petersen, Steen V; Thøgersen, Ida B; Valnickova, Zuzana;

    2010-01-01

    In this study, we show that human extracellular superoxide dismutase (EC-SOD) binds to low-density lipoprotein receptor-related protein (LRP). This interaction is most likely responsible for the removal of EC-SOD from the blood circulation via LRP expressed in liver tissue. The receptor recogniti...

  13. Multidrug resistance-associated protein 1 decreases the concentrations of antiepileptic drugs in cortical extracellular fluid in amygdale kindling rats

    Institute of Scientific and Technical Information of China (English)

    Ying-hui CHEN; Cui-cui WANG; Xia XIAO; Li WEI; Guoxiong XU

    2013-01-01

    Aim:To investigate whether multidrug resistance-associated protein 1 (MRP1) was responsible for drug resistence in refractory epilepsy in amygdale kindling rats.Methods:Rat amygdale kindling was used as a model of refractory epilepsy.The expression of MRP1 mRNA and protein in the brains was examined using RT-PCR and Western blot.MRP1-positive cells in the cortex and hippocampus were studied with immunohistochemical staining.The rats were intraperitoneally injected with phenytoin (50 mg/kg) or carbamazepine (20 mg/kg),and their concentrations in the cortical extracellular fluid were measured using microdialysis and HPLC.Probenecid,a MRP1 inhibitor (40 mmol/L,50 μL) was administered through an inflow tube into the cortex 30 min before injection of the antiepileptic drugs.Results:The expression of MRP1 mRNA and protein was significantly up-regulated in the cortex and hippocampus in amygdale kindling rats compared with the control group.Furthermore,the number of MRP1-positive cells in the cortex and hippocampus was also significantly increased in amygdale kindling rats.Microdialysis studies showed that the concentrations of phenytoin and carbamazepine in the cortical extracellular fluid were significantly decreased in amygdale kindling rats.Pre-administration of probenecid could restore the concentrations back to their control levels.Conclusion:Up-regulation of MRP1 is responsible for the resistance of brain cells to antiepileptic drugs in the amygdale kindling rats.

  14. Concentration determination of extracellular and intracellular red pigments produced by Monascus sp

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    Patricia Sanae Hamano

    2005-06-01

    Full Text Available In this work red pigments production was evaluated (by spectrophotometry in semi-synthetic medium by rotary shaker cultures, utilizing seven strains of Monascus sp. The strains isolated at LEB/DEQ/EPUSP had a absorbance average of extracellular red pigments higher than the others strains (13.0 and 9.6 U, respectively and the specific production of extracellular red pigments was from 1.7 until 3.5 times higher than the specific production of intracellular ones.Monascus sp. é um fungo filamentoso cuja principal aplicação industrial está relacionada à sua capacidade de produzir pigmentos vermelhos, utilizados como corantes naturais em alimentos, em substituição aos sintéticos. Neste trabalho a produção de pigmentos vermelhos foi avaliada (por meio de espectrofotometria de varredura em meio semi-sintético, empregando sete cepas de Monascus sp., através de cultivos conduzidos em incubador rotativo. As cepas isoladas no LEB/DEQ/EPUSP apresentaram média dos valores de absorbância dos pigmentos vermelhos extracelulares maior em relação às demais cepas (13,0 e 9,6 U, respectivamente, sendo que para as primeiras, a produção específica dos referidos pigmentos foi de 1,7 a 3,5 vezes maior que a produção específica dos pigmentos intracelulares.

  15. Concentration changes during venous occlusion of proteins with affinity for extracellular matrix in insulin-dependent diabetes mellitus A sign of vascular damage in patients with diabetic nephropathy?

    NARCIS (Netherlands)

    Myrup, B.; Rossing, P.; Jensen, T.; Gram, J.; Kluft, C.; Jespersen, J.

    1999-01-01

    Objective: To investigate protein concentration changes during venous occlusion of proteins with reported affinity for extracellular matrix (plasminogen activator inhibitor type 1, antithrombin III, fibronectin and von Willebrand factor) in comparison with proteins with no reported affinity (albumin

  16. Concentration changes during venous occlusion of proteins with affinity for extracellular matrix in insulin-dependent diabetes mellitus A sign of vascular damage in patients with diabetic nephropathy?

    NARCIS (Netherlands)

    Myrup, B.; Rossing, P.; Jensen, T.; Gram, J.; Kluft, C.; Jespersen, J.

    1999-01-01

    Objective: To investigate protein concentration changes during venous occlusion of proteins with reported affinity for extracellular matrix (plasminogen activator inhibitor type 1, antithrombin III, fibronectin and von Willebrand factor) in comparison with proteins with no reported affinity

  17. Tyramine biosynthesis in Enterococcus durans is transcriptionally regulated by the extracellular pH and tyrosine concentration.

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    Linares, Daniel M; Fernández, María; Martín, M Cruz; Alvarez, Miguel A

    2009-11-01

    The microbial decarboxylation of some amino acids leads to the undesirable presence of biogenic amines in foods. One of the most abundant and frequent biogenic amines found in fermented foods is tyramine, which is produced by the decarboxylation of tyrosine. In the present work, transcriptional analysis of tyramine biosynthesis in Enterococcus durans IPLA655, a strain isolated from cheese, was studied. The gene coding for the tyrosine decarboxylase (tdcA) and that coding for the tyrosine-tyramine antiporter (tyrP) form an operon transcribed from the promoter P(tdcA), the expression of which is regulated by the extracellular pH and tyrosine concentration. Quantification of gene expression during the log phase of growth showed high concentrations of tyrosine and acidic pH conditions to induce tdcA-tyrP polycistronic messenger transcription.

  18. High extracellular potassium ion concentration attenuates the blockade action of ketanserin on Kvl.3 channels expressed in xenopus oocytes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background Ketanserin (KT), a selective serotonin (5-HT) 2-receptor antagonist, reduces peripheral blood pressure by blocking the activation of peripheral 5-HT receptors. In this study electrophysiological method was used to investigate the effect of KT and potassium ion on Kv1.3 potassium channels and explore the role of blocker KT in the alteration of channel kinetics contributing to the potassium ion imbalances. Methods Kvl.3 channels were expressed in xenopus oocytes, and currents were measured using the two-microelectrode voltage-clamp technique. Results KCI made a left shift of activation and an inactivation curve of Kv1.3 current and accelerated the activation and inactivation time constant. High extracellular [K+] attenuated the blockade effect of KT on Kv1.3 channels. In the presence of KT and KCI the activation and inactivation time constants were not influenced significantly no matter what was administered first. KT did not significantly inhibit Kv1.3 current induced by tetraethylammonium (TEA). Conclusions KT is a weak blocker of Kv1.3 channels at different concentrations of extracellular potassium and binds to the intracellular side of the channel pore. The inhibitor KT of ion channels is not fully effective in clinical use because of high [K+]o and other electrolyte disorders.

  19. Probing Intracellular Element Concentration Changes during Neutrophil Extracellular Trap Formation Using Synchrotron Radiation Based X-Ray Fluorescence

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    Niemiec, Maria J.; Laforce, Brecht; Garrevoet, Jan; Vergucht, Eva; De Rycke, Riet; Cloetens, Peter; Urban, Constantin F.; Vincze, Laszlo

    2016-01-01

    High pressure frozen (HPF), cryo-substituted microtome sections of 2 μm thickness containing human neutrophils (white blood cells) were analyzed using synchrotron radiation based X-ray fluorescence (SR nano-XRF) at a spatial resolution of 50 nm. Besides neutrophils from a control culture, we also analyzed neutrophils stimulated for 1–2 h with phorbol myristate acetate (PMA), a substance inducing the formation of so-called Neutrophil Extracellular Traps (or NETs), a defense system again pathogens possibly involving proteins with metal chelating properties. In order to gain insight in metal transport during this process, precise local evaluation of elemental content was performed reaching limits of detection (LODs) of 1 ppb. Mean weight fractions within entire neutrophils, their nuclei and cytoplasms were determined for the three main elements P, S and Cl, but also for the 12 following trace elements: K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, Sr and Pb. Statistical analysis, including linear regression provided objective analysis and a measure for concentration changes. The nearly linear Ca and Cl concentration changes in neutrophils could be explained by already known phenomena such as the induction of Ca channels and the uptake of Cl under activation of NET forming neutrophils. Linear concentration changes were also found for P, S, K, Mn, Fe, Co and Se. The observed linear concentration increase for Mn could be related to scavenging of this metal from the pathogen by means of the neutrophil protein calprotectin, whereas the concentration increase of Se may be related to its antioxidant function protecting neutrophils from the reactive oxygen species they produce against pathogens. We emphasize synchrotron radiation based nanoscopic X-ray fluorescence as an enabling analytical technique to study changing (trace) element concentrations throughout cellular processes, provided accurate sample preparation and data-analysis. PMID:27812122

  20. Mechanism by which an elevation of extracellular glucide concentration induces pigment aggregation in medaka melanophores.

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    Fujii, Ryozo; Goda, Makoto; Oshima, Noriko

    2002-09-15

    An increase in glucide concentration induces pigment aggregation in melanophores in the skin on scales isolated from the medaka, Oryzias latipes. In this study, hexoses (including the common D-isomers of glucose, galactose, fructose, and mannitol) were examined. Denervated melanophores were refractory to such stimuli. An alpha-adrenolytic agent, phentolamine, effectively blocked the responses of normally innervated melanophores. The pigment-aggregating action of glucide was inhibited by withdrawal of Ca(2+) and Mg(2+) ions from the medium. A specific blocker of voltage-dependent N-type Ca(2+) channels, the omega-conotoxin GVIA, also inhibited the glucide action. The conclusion derived is that an elevation of glucide levels acts to open Ca(2+) channels of presynaptic membranes of sympathetic postganglionic fibers, and the consequently released adrenergic transmitter acts on the effector cells to induce the aggregation of their pigmentary organelles. Copyright 2002 Wiley-Liss, Inc.

  1. Activity of the TonEBP/OREBP transactivation domain varies directly with extracellular NaCl concentration.

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    Ferraris, Joan D; Williams, Chester K; Persaud, Prita; Zhang, Zheng; Chen, Ye; Burg, Maurice B

    2002-01-22

    Hypertonicity-induced binding of the transcription factor TonEBP/OREBP to its cognate DNA element, ORE/TonE, is associated with increased transcription of several osmotically regulated genes. Previously, it was found that hypertonicity rapidly causes nuclear translocation and phosphorylation of TonEBP/OREBP and, more slowly, increases TonEBP/OREBP abundance. Also, the C terminus of TonEBP/OREBP was found to contain a transactivation domain (TAD). We have now tested for tonicity dependence of the TAD activity of the 983 C-terminal amino acids of TonEBP/OREBP. HepG2 cells were cotransfected with a reporter construct and one of several TAD expression vector constructs. The reporter construct contained GAL4 DNA binding elements, a minimal promoter, and the Photinus luciferase gene. TAD expression vectors generate chimeras comprised of the GAL4 DNA binding domain fused to (i) the 983 C-terminal amino acids of TonEBP/OREBP, (ii) 17 glutamine residues, (iii) the TAD of c-Jun, or (iv) no TAD. All TAD-containing chimeras were functional at normal extracellular osmolality (300 mosmol/kg), but the activity only of the chimera containing the 983 C-terminal amino acids of TonEBP/OREBP varied with extracellular NaCl concentration, decreasing by >80% at 200 mosmol/kg and increasing 8-fold at 500 mosmol/kg. The chimera containing the 983 C-terminal amino acids of TonEBP/OREBP was constitutively localized to the nucleus and showed tonicity-dependent posttranslational modification consistent with phosphorylation. The activity at 500 mosmol/kg was reduced by herbimycin, a tyrosine kinase inhibitor and by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, a protein kinase CK2 inhibitor. Thus, the 983 C-terminal amino acids of TonEBP/OREBP contain a TAD that is regulated osmotically, apparently by tonicity-dependent phosphorylation.

  2. Sub-inhibitory tigecycline concentrations induce extracellular matrix binding protein Embp dependent Staphylococcus epidermidis biofilm formation and immune evasion.

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    Weiser, Julian; Henke, Hanae A; Hector, Nina; Both, Anna; Christner, Martin; Büttner, Henning; Kaplan, Jeffery B; Rohde, Holger

    2016-09-01

    Biofilm-associated Staphylococcus epidermidis implant infections are notoriously reluctant to antibiotic treatment. Here we studied the effect of sub-inhibitory concentrations of penicillin, oxacillin, vancomycin, daptomycin, linezolid and tigecycline on S. epidermidis 1585 biofilm formation, expression of extracellular matrix binding protein (Embp) and potential implications for S. epidermidis - macrophage interactions. Penicillin, vancomycin, daptomycin, and linezolid had no biofilm augmenting effect at any of the concentrations tested. In contrast, at sub-inhibitory concentrations tigecycline and oxacillin exhibited significant biofilm inducing activity. In S. epidermidis 1585, SarA is a negative regulator of giant 1 MDa Embp, and down regulation of sarA induces Embp-dependent assembly of a multi-layered biofilm architecture. Dot blot immune assays, confocal laser scanning microscopy, and qPCR showed that under biofilm inducing conditions, tigecycline augmented embp expression compared to the control grown without antibiotics. Conversely, expression of regulator sarA was suppressed, suggesting that tigecycline exerts its effects on embp expression through SarA. Tigecycline failed to induce biofilm formation in embp transposon mutant 1585-M135, proving that under these conditions Embp up-regulation is necessary for biofilm accumulation. As a functional consequence, tigecycline induced biofilm formation significantly impaired the up-take of S. epidermidis by mouse macrophage-like cell line J774A.1. Our data provide novel evidence for the molecular basis of antibiotic induced biofilm formation, a phenotype associated with inherently increased antimicrobial tolerance. While this could explain failure of antimicrobial therapies, persistence of S. epidermidis infections in the presence of sub-inhibitory antimicrobials is additionally propelled by biofilm-related impairment of macrophage-mediated pathogen eradication.

  3. Effects of extracellular iron concentration on calcium absorption and relationship between Ca2+ and cell apoptosis in Caco-2 cells

    Institute of Scientific and Technical Information of China (English)

    Li Wang; Qing Li; Xiang-Lin Duan; Yan-Zhong Chang

    2005-01-01

    AIM: To determine the method of growing small intestinal epithelial cells in short-term primary culture and to investigate the effect of extracellular iron concentration ([Fe3+]) on calcium absorption and the relationship between the rising intracellular calcium concentration ([Ca2+]i) and cell apoptosis in human intestinal epithelial Caco-2 cells. METHODS: Primary culture was used for growing small intestinal epithelial cells. [Ca2+]i was detected by a confocal laser scanning microscope. The changes in [Ca2+]i were represented by fluorescence intensity (FI). The apoptosis was evaluated by flow cytometry.RESULTS: Isolation of epithelial cells and preservation of its three-dimensional integrity were achieved using the digestion technique of a mixture of collagenase Ⅺ and dispase Ⅰ. Purification of the epithelial cells was facilitated by using a simple differential sedimentation method. The results showed that proliferation of normal gut epithelium in vitro was initially dependent upon the maintenance of structural integrity of the tissue. If 0.25% trypsin was used for digestion, the cells were severely damaged and very difficult to stick to the Petri dish for growing. The Fe3+ chelating agent desferrioxamine (100, 200 and 300 μmol/L) increased the FI of Caco-2 cells from 27.50±13.18 (control,n = 150) to 35.71±13.99 (n = 150, P<0.01), 72.19±35.40 (n = 150, P<0.01) and 211.34±29.03 (n = 150, P<0.01) in a concentration-dependent manner. There was a significant decrease in the FI of Caco-2 cells treated by ferric ammonium citrate (FAC, a Fe3+ donor; 10, 50 and 100 μmol/L). The FIvalue of Caco-2 cells treated by FAC was 185.85±33.77 (n = 150, P<0.01), 122.73±58.47 (n = 150, P<0.01), and 53.29±19.82 (n = 150, P<0.01), respectively, suggesting that calcium absorption was influenced by [Fe3+]. Calcium ionophore A23187 (0.1, 1.0 and 10 μmol/L) increased the FI of Caco-2 cells from 40.45±13.95 (control, n = 150) to 45.19±21.95 (n = 150, P<0

  4. Development of a Rat Plasma and Brain Extracellular Fluid Pharmacokinetic Model for Bupropion and Hydroxybupropion Based on Microdialysis Sampling, and Application to Predict Human Brain Concentrations.

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    Cremers, Thomas I F H; Flik, Gunnar; Folgering, Joost H A; Rollema, Hans; Stratford, Robert E

    2016-05-01

    Administration of bupropion [(±)-2-(tert-butylamino)-1-(3-chlorophenyl)propan-1-one] and its preformed active metabolite, hydroxybupropion [(±)-1-(3-chlorophenyl)-2-[(1-hydroxy-2-methyl-2-propanyl)amino]-1-propanone], to rats with measurement of unbound concentrations by quantitative microdialysis sampling of plasma and brain extracellular fluid was used to develop a compartmental pharmacokinetics model to describe the blood-brain barrier transport of both substances. The population model revealed rapid equilibration of both entities across the blood-brain barrier, with resultant steady-state brain extracellular fluid/plasma unbound concentration ratio estimates of 1.9 and 1.7 for bupropion and hydroxybupropion, respectively, which is thus indicative of a net uptake asymmetry. An overshoot of the brain extracellular fluid/plasma unbound concentration ratio at early time points was observed with bupropion; this was modeled as a time-dependent uptake clearance of the drug across the blood-brain barrier. Translation of the model was used to predict bupropion and hydroxybupropion exposure in human brain extracellular fluid after twice-daily administration of 150 mg bupropion. Predicted concentrations indicate that preferential inhibition of the dopamine and norepinephrine transporters by the metabolite, with little to no contribution by bupropion, would be expected at this therapeutic dose. Therefore, these results extend nuclear imaging studies on dopamine transporter occupancy and suggest that inhibition of both transporters contributes significantly to bupropion's therapeutic efficacy.

  5. Release of ATP from marginal cells in the cochlea of neonatal rats can be induced by changes in extracellular and intracellular ion concentrations.

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    Yating Peng

    Full Text Available BACKGROUND: Adenosine triphosphate (ATP plays an important role in the cochlea. However, the source of ATP and the mechanism by which it is released remain unclear. This study investigates the presence and release mechanism of ATP in vitro cultured marginal cells isolated from the stria vascularis of the cochlea in neonatal rats. METHODS: Sprague-Dawley rats aged 1-3 days old were used for isolation, in vitro culture, and purification of marginal cells. Cultured marginal cells were verified by flow cytometry. Vesicles containing ATP in these cells were identified by fluorescence staining. The bioluminescence assay was used for determination of ATP concentration in the extracellular fluid released by marginal cells. Assays for ATP concentration were performed when the ATP metabolism of cells was influenced, and ionic concentrations in intracellular and extracellular fluid were found to change. RESULTS: Evaluation of cultured marginal cells with flow cytometry revealed the percentage of fluorescently-labeled cells as 92.9% and 81.9%, for cytokeratin and vimentin, respectively. Quinacrine staining under fluorescence microscopy revealed numerous green, star-like spots in the cytoplasm of these cells. The release of ATP from marginal cells was influenced by changes in the concentration of intracellular and extracellular ions, namely extracellular K(+ and intra- and extracellular Ca(2+. Furthermore, changes in the concentration of intracellular Ca(2+ induced by the inhibition of the phospholipase signaling pathway also influence the release of ATP from marginal cells. CONCLUSION: We confirmed the presence and release of ATP from marginal cells of the stria vascularis. This is the first study to demonstrate that the release of ATP from such cells is associated with the state of the calcium pump, K(+ channel, and activity of enzymes related to the phosphoinositide signaling pathway, such as adenylate cyclase, phospholipase C, and phospholipase A(2.

  6. Plasma concentrations of extracellular matrix protein fibulin-1 are related to cardiovascular risk markers in chronic kidney disease and diabetes

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    Scholze Alexandra

    2013-01-01

    Full Text Available Abstract Background Fibulin-1 is one of a few extracellular matrix proteins present in blood in high concentrations. We aimed to define the relationship between plasma fibulin-1 levels and risk markers of cardiovascular disease. Methods Plasma fibulin-1 was determined in subjects with chronic kidney disease (n = 32; median age 62.5, inter-quartile range 51 – 73 years and 60 age-matched control subjects. Among kidney disease patients serological biomarkers related to cardiovascular disease (fibrinogen, interleukin 6, C-reactive protein were measured. Arterial applanation tonometry was used to determine central hemodynamic and arterial stiffness indices. Results We observed a positive correlation of fibulin-1 levels with age (r = 0.38; p = 0.033, glycated hemoglobin (r = 0.80; p = 0.003, creatinine (r = 0.35; p = 0.045, and fibrinogen (r = 0.39; p = 0.027. Glomerular filtration rate and fibulin-1 were inversely correlated (r = −0.57; p = 0.022. There was a positive correlation between fibulin-1 and central pulse pressure (r = 0.44; p = 0.011 and central augmentation pressure (r = 0.55; p = 0.001. In a multivariable regression model, diabetes, creatinine, fibrinogen and central augmentation pressure were independent predictors of plasma fibulin-1. Conclusion Increased plasma fibulin-1 levels were associated with diabetes and impaired kidney function. Furthermore, fibulin-1 levels were associated with hemodynamic cardiovascular risk markers. Fibulin-1 is a candidate in the pathogenesis of cardiovascular disease observed in chronic kidney disease and diabetes.

  7. Antioxidant effect of hyaluronan on polymorphonuclear leukocyte-derived reactive oxygen species is dependent on its molecular weight and concentration and mainly involves the extracellular space

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    Rafał Krasiński

    2009-05-01

    Full Text Available Introduction: Hyaluronan (HA, a component of the extracellular matrix, may regulate immune cell functions through its interactions with cellular receptors. Besides its effect on cytokine and chemokine production, its antioxidant properties have been described. However, the mechanisms of this are not fully elucidated. The aim of this study was to evaluate the relationship between HA concentration and molecular weight and its antioxidant properties towards human neutrophils. Also assessed was whether the antioxidant effect of HA is connected with a reduction in intracellular oxygen potential, which could indicate its direct effect on neutrophil respiratory burst.Materials/Methods: The relationship between HA’s antioxidant properties and its concentration and molecular weight was assessed by the luminol-enhanced chemiluminescence method (CL. To evaluate the effect of HA on intracellular oxygen potential selectively, the dihydrorhodamine 123 (DHR123 flow cytometric method was used.Results: Reduction of both HA molecular weight and its concentration decreased its antioxidant properties in the CL method. A selective effect of HA on intracellular oxygen potential measured by the DHR123 method was not shown.Conclusions: The antioxidant properties of HA are related to both its molecular weight and its concentration. The lack of an antioxidant effect of HA in the DHR123 test compared with a significant reduction in CL values at the same HA concentration suggests that HA acts mainly as a chemical ROI scavenger in the extracellular space.

  8. Immediate response of Ca2+ concentration in myocardial cells against oxidation stress by extracellular photosensitization reaction using Talaporfin sodium for the arrhythmia treatment application

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    Ogawa, Emiyu; Takahashi, Mei; Ito, Arisa; Arai, Tsunenori

    2014-02-01

    We studied the immediate response of myocardial cells by continuous observation using confocal microscope against oxidation stress by extracellular photosensitization reaction using Talaporfin sodium for tachyarrhythmia treatment application. Immediate response in order from several seconds to several minutes is required for the arrhythmia treatment since operators should judge the therapeutic effect during the tachyarrhythmia ablation procedure. To understand the immediate response of myocardial cells, we measured the intracellular Ca2+ concentration using fluo-4 AM during and after the extracellular photosensitization reaction. Talaporfin sodium concentration was varied 10-30 μg/ml. A red diode laser of 663 nm in wavelength was irradiated under the microscope with the radiant exposure of 40 J/cm2 and irradiance of 0.29 W/cm2. We observed the fluorescence image of fluo-4 AM each 400 ms during until 10 min after the photosensitization reaction. The myocardial cell beatings were stopped about 2 s after the beginning of the laser irradiation. The blebs were formed with the Ca2+ inflow. The intracellular Ca2+ was re-decreased after the bleb formation and then the cell necrosis was induced. The cell lethality 10 min after the laser irradiation was less than bleb formation ratio. The time response of the cell necrosis was shortened with the photosensitizer concentration increasing and the minimum average value was 209 s in the case of the 30 μg/ml in photosensitizer concentration and 40 J/cm2 in the radiant exposure. We think this extracellular photosensitization reaction may be applicable to tachyarrhythmia treatment in terms of its immediate response.

  9. Evidence for Tonic Control by the GABAA Receptor of Extracellular D-Serine Concentrations in the Medial Prefrontal Cortex of Rodents

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    Asami Umino

    2017-08-01

    Full Text Available Endogenous D-serine is a putative dominant co-agonist for the N-methyl-D-aspartate glutamate receptor (NMDAR in the mammalian forebrain. Although the NMDAR regulates the higher order brain functions by interacting with various neurotransmitter systems, the possible interactions between D-serine and an extra-glutamatergic system largely remain elusive. For the first time, we show in the rat and mouse using an in vivo microdialysis technique that the extracellular D-serine concentrations are under tonic increasing control by a major inhibitory transmitter, GABA, via the GABAA (GABAAR in the medial prefrontal cortex (mPFC. Thus, an intra-mPFC infusion of a selective GABAAR antagonist, bicuculline (BIC, caused a concentration-dependent and reversible decrease in the extracellular levels of D-serine in the rat mPFC without affecting those of another intrinsic NMDAR coagonist, glycine and an NMDAR agonist, L-glutamate. The decreasing effects of BIC were eliminated by co-infusion of a selective GABAA agonist, muscimol (MUS and were mimicked by a GABAA antagonist, gabazine (GBZ. In contrast, selective blockade of the GABAB or homomeric ρGABAA (formerly GABAC receptor by saclofen or (1,2,5,6-tetrahydropyridin-4-yl-methylphosphinic acid (TPMPA, respectively, failed to downregulate the prefrontal extracellular D-serine levels. Moreover, the local BIC application attenuated the ability of NMDA given to the mPFC to increase the cortical extracellular concentrations of taurine, indicating the hypofunction of the NMDAR. Finally, in the mouse mPFC, the reduction of the extracellular D-serine levels by a local injection of BIC into the prefrontal portion was replicated, and was precluded by inhibition of the neuronal or glial activity by co-local injection with tetrodotoxin (TTX or fluorocitrate (Fluo, respectively. These findings suggest that the GABAAR-mediated regulation of the D-serine signaling may exert fine-tuning of the NMDAR function and require both

  10. Inhibition of Brain Swelling after Ischemia-Reperfusion by β-Adrenergic Antagonists: Correlation with Increased K+ and Decreased Ca2+ Concentrations in Extracellular Fluid

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    Dan Song

    2014-01-01

    Full Text Available Infarct size and brain edema following ischemia/reperfusion are reduced by inhibitors of the Na+, K+, 2Cl−, and water cotransporter NKCC1 and by β1-adrenoceptor antagonists. NKCC1 is a secondary active transporter, mainly localized in astrocytes, driven by transmembrane Na+/K+ gradients generated by the Na+,K+-ATPase. The astrocytic Na+,K+-ATPase is stimulated by small increases in extracellular K+ concentration and by the β-adrenergic agonist isoproterenol. Larger K+ increases, as occurring during ischemia, also stimulate NKCC1, creating cell swelling. This study showed no edema after 3 hr medial cerebral artery occlusion but pronounced edema after 8 hr reperfusion. The edema was abolished by inhibitors of specifically β1-adrenergic pathways, indicating failure of K+-mediated, but not β1-adrenoceptor-mediated, stimulation of Na+,K+-ATPase/NKCC1 transport during reoxygenation. Ninety percent reduction of extracellular Ca2+ concentration occurs in ischemia. Ca2+ omission abolished K+ uptake in normoxic cultures of astrocytes after addition of 5 mM KCl. A large decrease in ouabain potency on K+ uptake in cultured astrocytes was also demonstrated in Ca2+-depleted media, and endogenous ouabains are needed for astrocytic K+ uptake. Thus, among the ionic changes induced by ischemia, the decrease in extracellular Ca2+ causes failure of the high-K+-stimulated Na+,K+-ATPase/NKCC1 ion/water uptake, making β1-adrenergic activation the only stimulus and its inhibition effective against edema.

  11. Human resting extracellular heat shock protein 72 concentration decreases during the initial adaptation to exercise in a hot, humid environment

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    Marshall, Helen C.; Ferguson, Richard A.; Nimmo, Myra A.

    2006-01-01

    Heat shock protein (Hsp) 72 is a cytosolic protein that also is present in the circulation. Extracellular Hsp72 (eHsp72) is inducible by exercise and is suggested to act as a danger signal to the immune system. The adaptive response of eHsp72 to repeated exercise-heat exposures in humans remains to be determined. An intracellular animal study found a reduced Hsp72 response, with no change in resting levels, during heat stress after a single day of passive heat acclimation. The current study therefore tested whether adaptations in human eHsp72 levels would similarly occur 24 hours after a single exercise-heat exposure. Seven males completed cycle exercise (42.5% V̇O2peak for 2 hours) in a hot, humid environment (38°C, 60% relative humidity) on each of 2 consecutive days. Blood samples were obtained from an antecubital vein before exercise and 0 hours and 22 hours postexercise for the analysis of eHsp72. Exercise-heat stress resulted in enhanced eHsp72, with a similar absolute increase found on both days (day 1: 1.26 ng/mL [0.80 ng/mL]; day 2: 1.29 ng/mL [1.60 ng/mL]). Resting eHsp72 decreased from rest on day 1 to day 2's 22-hour postexercise sample (P < 0.05). It is suggested that the reduction in resting eHsp72 after 2 consecutive exercise-heat exposures is possibly due to an enhanced removal from the circulation, for either immunoregulatory functions, or for improved cellular stress tolerance in this initial, most stressful period of acclimation. PMID:16817318

  12. Effect of pH and temperature on stability and kinetics of novel extracellular serine alkaline protease (70 kDa).

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    Bhunia, Biswanath; Basak, Bikram; Mandal, Tamal; Bhattacharya, Pinaki; Dey, Apurba

    2013-03-01

    A novel extracellular serine protease (70 kDa by SDS-PAGE) was purified and characterized. This enzyme retained more than 93% of its initial activity after preincubation for 30 min at 37 °C in the presence of 25% (v/v) tested organic solvents and showed feather degradation activity. The purified enzyme was deactivated at various combinations of pH and temperature to examine the interactive effect of them on enzyme activity. The deactivation process was modeled as first-order kinetics and the deactivation rate constant (k(d)) was found to be minimum at pH 9 and 37 °C. The kinetic analysis of enzyme over a range of pH values indicated two pK values at 6.21 and at 10.92. The lower pK value was likely due to the catalytic histidine in the free enzyme and higher pK value likely reflected deprotonation of the proline moiety of the substrate but ionization of the active site serine is another possibility. Inhibition kinetic showed that enzyme is serine protease because enzyme was competitively inhibited by antipain and aprotinin as these compounds are known to be competitive inhibitors of serine protease. The organic solvent, thermal and pH tolerances of enzyme suggested that it may have potential for use as a biocatalyst in industry.

  13. Imunofenotipagem e remodelamento da matriz extracelular na sarcoidose pulmonar e extrapulmonar Immunophenotyping and extracellular matrix remodeling in pulmonary and extrapulmonary sarcoidosis

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    Pedro Henrique Ramos Quintino da Silva

    2012-06-01

    Full Text Available OBJETIVO: Investigar o significado de marcadores de imunidade celular e de componentes elásticos/colágeno da matriz extracelular em estruturas granulomatosas em biópsias de pacientes com sarcoidose pulmonar ou extrapulmonar. MÉTODOS: Determinações qualitativas e quantitativas de células inflamatórias, de fibras de colágeno e de fibras elásticas em estruturas granulomatosas em biópsias cirúrgicas de 40 pacientes com sarcoidose pulmonar e extrapulmonar foram realizadas por histomorfometria, imuno-histoquímica, e técnicas de coloração com picrosirius e resorcina-fucsina de Weigert. RESULTADOS: A densidade de linfócitos, macrófagos e neutrófilos nas biópsias extrapulmonares foi significativamente maior do que nas biópsias pulmonares. Os granulomas pulmonares apresentaram uma quantidade significativamente maior de fibras de colágeno e menor densidade de fibras elásticas que os granulomas extrapulmonares. A quantidade de macrófagos nos granulomas pulmonares correlacionou-se com CVF (p OBJECTIVE: To investigate the significance of cellular immune markers, as well as that of collagen and elastic components of the extracellular matrix, within granulomatous structures in biopsies of patients with pulmonary or extrapulmonary sarcoidosis. METHODS: We carried out qualitative and quantitative evaluations of inflammatory cells, collagen fibers, and elastic fibers in granulomatous structures in surgical biopsies of 40 patients with pulmonary and extrapulmonary sarcoidosis using histomorphometry, immunohistochemistry, picrosirius red staining, and Weigert's resorcin-fuchsin staining. RESULTS: The extrapulmonary tissue biopsies presented significantly higher densities of lymphocytes, macrophages, and neutrophils than did the lung tissue biopsies. Pulmonary granulomas showed a significantly higher number of collagen fibers and a lower density of elastic fibers than did extrapulmonary granulomas. The amount of macrophages in the lung samples

  14. Effect of extracellular adenosine 5'-triphosphate on cryopreserved epididymal cat sperm intracellular ATP concentration, sperm quality, and in vitro fertilizing ability.

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    Thuwanut, Paweena; Arya, Nlin; Comizzoli, Pierre; Chatdarong, Kaywalee

    2015-09-15

    Intracellular adenosine 5'-triphosphate (ATP) is essential for supporting sperm function in the fertilization process. During cryopreservation, damage of sperm mitochondrial membrane usually leads to compromised production of intracellular ATP. Recently, extracellular ATP (ATPe) was introduced as a potent activator of sperm motility and fertilizing ability. This study aimed to evaluate (1) levels of intracellular ATP in frozen-thawed epididymal cat sperm after incubation with ATPe and (2) effects of ATPe on epididymal cat sperm parameters after freezing and thawing. Eighteen male cats were included. For each replicate, epididymal sperm from two cats were pooled to one sample (N = 9). Each pooled sample was cryopreserved with the Tris-egg yolk extender into three straws. After thawing, the first and second straws were incubated with 0-, 1.0-, or 2.5-mM ATPe for 10 minutes and evaluated for sperm quality at 10 minutes, 1, 3, and 6 hours after thawing and fertilizing ability. The third straw was evaluated for intracellular ATP concentration in control and with 2.5-mM ATPe treatment. Higher concentration of intracellular sperm ATP was observed in the samples treated with 2.5-mM ATPe compared to the controls (0.339 ± 0.06 μg/2 × 10(6) sperm vs. 0.002 ± 0.003 μg/2 × 10(6) sperm, P ≤ 0.05). In addition, incubation with 2.5-mM ATPe for 10 minutes promoted sperm motility (56.7 ± 5.0 vs. 53.3 ± 4.4%, P ≤ 0.05) and progressive motility (3.1 ± 0.2 vs. 2.8 ± 0.4, P ≤ 0.05), mitochondrial membrane potential (36.4 ± 5.5 vs. 28.7 ± 4.8%, P ≤ 0.05), and blastocyst rate (36.1 ± 7.0 and 28.8 ± 7.4%, P ≤ 0.05) compared with the controls. In contrast, ATPe remarkably interfered acrosome integrity after 6 hours of postthawed incubation. In sum, the present finding that optimal incubation time of postthaw epididymal cat sperm under proper ATPe condition might constitute a rationale for the studies on other endangered wild felids regarding sperm quality and embryo

  15. Interaction of leukemic cells with proteins of the extracellular matrix Interações de células leucêmicas com proteínas da matriz extracelular

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    Adriana Rodrigues-Anjos

    2004-01-01

    Full Text Available The interaction of neoplastic cells with basement membrane molecules is the first step for the dissemination of tumor cells in vivo. Leukemic cells have a great ability to spread in the host, since cells are released from the bone marrow to the circulation. In this study we analysed whether CEM, U937, K562 and HL-60 cells were able to attach to different concentrations of laminin and/or fibronectin and/or type IV collagen. Attachment to type IV collagen was low, but it increased with the addition of laminin and occurred in all four leukemic cell lines. On the other hand, attachment to fibronectin was higher, but it decreased with the addition of laminin in the assays using U937 and HL-60 cells. The combination of type IV collagen and fibronectin was a good substratum for cellular attachment. However, the addition of laminin to this substratum impaired its attachment activity in U937, HL-60 and K562. These data suggest that laminin may control cellular attachment to the extracellular matrix during leukemic dissemination in hosts in different ways.A interação de células neoplásicas com moléculas da membrana basal é a primeira etapa para a disseminação, in vivo, de células tumorais in vivo. As células leucêmicas possuem grande capacidade de espraiamento e disseminação no organismo uma vez que as mesmas são liberadas da medula óssea para a circulação. Neste trabalho avaliamos a capacidade das linhagens celulares CEM, U937, K562 and HL-60 em aderirem a uma matriz extracelular constituída por diferentes concentrações de laminina e,ou fibronectina e sobre colágeno IV. A adesão de todas a linhagens leucêmicas a colágeno IV foi baixa, mas aumentou com a associação à laminina. Por outro lado, as células U937 e HL-60 apresentaram alta ligação à fibronectina porém, foi reduzida com a adição de laminina. A associação de colágeno IV e fibronectina possibilitou um bom substrato para a adesão celular. Entretanto, a adi

  16. Growth and yield of summer squash: effect of the ionic concentration of nutrient solutionCrescimento e produtividade da abobrinha italiana: efeito da concentração iônica da solução nutritiva

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    Tiago Zanatta Aumonde

    2011-07-01

    Full Text Available With the objective of evaluating the effect of different ionic concentrations of the nutrient solution on growth of summer squash cultivated in raw rice husk substrate with leaching recirculation, two experiments were conducted in two crop-seasons: spring-summer of 2005 and summer-autumn of 2006, in Pelotas, RS. Four ionic concentrations of the nutrient solution (based on electrical conductivity - EC were studied: 1.3; 1.7; 2.1 and 4.2 dS m-1. Crop growth was determinated by accumulated dry mass production and partitioning among the different above-ground plant organs (leafs, stem and fruits at the end of the crop-seasons. Fruit yield was also evaluated. The obtained results indicate that ionic concentrations equal or lower than 1.7 dS m-1 were limiting for proper growth and yield of the crop. The effect of high ionic concentration of the nutrient solution (above 2.1 dS m-1 on dry mass production and partitioning varied according to the crop-season. The lower solar radiation availability of the summer-autumn crop season minimized the effects of the different concentrations of nutrient solution on dry mass production and partitioning to the fruits, as well as on the yield. The fruits comprised from 28 to 52% of the total above-ground dry mass production. Fruits represented the largest sink of assimilates of the plant only at 2.1 dS m-1 ionic concentration of the nutrient solution and in crescent solar radiation availability condition (spring-summer. According the mathematics models, the electrical conductivity that maximizes dry mass production and yield is approximately 3.0 dS m-1 for both crop-seasons.Com o objetivo de avaliar o efeito de diferentes concentrações iônicas da solução nutritiva sobre o crescimento e a produtividade da abobrinha italiana cultivada em substrato de casca de arroz in natura com recirculação dos lixiviados, foram realizados dois experimentos em duas épocas de cultivo: primavera-verão de 2005 e verão-outono de

  17. Effect of nitrogen narcosis on extracellular levels of dopamine and its metabolites in the rat striatum, using intracerebral microdialysis.

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    Barthelemy-Requin, M; Semelin, P; Risso, J J

    1994-12-19

    In man, nitrogen narcosis is characterized by euphoria, impaired cognitive function, neuromuscular incoordination and, ultimately, loss of consciousness. Because of the motor movement disorders, we chose to study the nigrostriatal system, whose major function is to regulate the extrapyramidal nervous system. The purpose of this investigation was to monitor changes in extracellular levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum of conscious rats, using intracerebral microdialysis. Results show a 40% decrease in extracellular DA concentration, a 59% increase in extracellular DOPAC and an increase in HVA starting with exposure to the nitrogen mixture. Thirty minutes after the beginning of the exposure, a compensation phase took place. HVA returns to its initial basal value, and levels of DOPAC and DA returned towards normal but never reached their initial values. These results contrast with those observed during the High Pressure Neurological Syndrome (HPNS, 5.1 MPa of helium pressure) in which there is a significant increase in extracellular DA. Therefore, some of the symptoms of nitrogen narcosis may be linked with the decrease in the extracellular DA levels.

  18. Decorina e Condroitim sulfato na remodelação da matriz extracelular do línquen escleroso vulvar Decorin and chondroitin sulfate in linchen sclerosus extracellular matrix remodeling

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    Adriana de Carvalho Corrêa

    2005-12-01

    Full Text Available FUNDAMENTOS: O líquen escleroso (LS apresenta zona de hialinização do colágeno na derme superior característica, que persiste pouco definida do ponto de vista morfológico e cujo significado permanece sem explicação. Já se pôde demonstrar que no LS há profundas modificações da matriz extracelular (MEC, com acúmulo de proteínas colagênicas e de glicosaminoglicanos sulfatados na região hialina. OBJETIVOS: Caracterizar morfologicamente a presença nessa zona de decorina e condroitim sulfato que, ao interagir com as fibrilas colágenas, entre outras proteínas matriciais, poderiam contribuir para essa peculiar apresentação da MEC. MÉTODOS: 31 casos de LS vulvar foram subdivididos segundo a gradação histológica de Hewitt e analisados por imuno-histoquímica utilizando anticorpos contra decorina e condroitim sulfato revelados pela diaminobenzidina. Esses resultados foram comparados aos do grupo controle constituído por fragmentos de retalhos cutâneos excisados durante cirurgias corretivas da região vulvoperineal. RESULTADOS: Ocorreu predomínio da decorina quando a matriz apresentava um aspecto frouxo/edematoso, e o condroitim sulfato foi mais evidente quando a MEC assumia um padrão compacto, parecendo que ambos contribuem para o aspecto hialino, porém em fases diferentes da patogenia dessa doença. CONCLUSÕES: A seqüência observada na síntese desses proteoglicanos/glicosaminoglicanos levou à suposição de que a decorina seja um possível marcador precoce do LS vulvar e de que o condroitim sulfato possa estar relacionado à contenção da alteração matricial no nível da derme média.BACKGROUND: Lichen sclerosus is characterized by a collagenous hyaline/homogeneous zone at upper dermis, which remains undefined morphologically and biologically. Our previous investigation showed that there are several changes at the extracellular matrix hyaline zone, such as accumulation of collagenic proteins (types I and III and

  19. Enzimas hidrolíticas extracelulares de isolados de rizóbia nativos da Amazônia Central, Amazonas, Brasil Extracellular hydrolytic enzymes in indigenous strains of rhizobia in Central Amazonia, Amazonas, Brazil

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    Arlem Nascimento de Oliveira

    2006-12-01

    Full Text Available A associação rizóbia x leguminosa contribui para enriquecer o solo com nitrogênio por meio da fixação biológica. Entretanto, pouco se conhece a respeito do perfil enzimático desses microrganismos. Nesse contexto, a presente investigação propõe avaliar a produção de enzimas hidrolíticas extracelulares por isolados de rizóbia nativos da Amazônia Central. Essa triagem constitui o primeiro passo na seleção de microrganismos nativos que são potencialmente exploráveis como produtores de enzimas. Foram testados 67 isolados nativos de rizóbia para as atividades amilolítica, celulolítica, lactolítica, lipolítica, pectinolítica e proteolítica, em meio YMA modificado. A atividade ureolítica foi detectada em meio ágar-uréia. As bactérias isoladas dos nódulos de feijão caupi mostraram maior capacidade em produzir enzimas do que os isolados bacterianos de soja. De todas as enzimas hidrolíticas avaliadas, apenas a pectinase não foi detectada neste estudo. Amilase (32,8%, protease (28,4%, urease (20,9% e carboximetilcelulase (9,0% foram as enzimas mais freqüentes produzidas pelos isolados. Neste trabalho, apenas as enzimas amilase e protease variaram significativamente entre os isolados de rizóbia. Os isolados INPA R-926 e INPA R-915 exibiram os maiores índices amilolíticos (IE = 3,1 e proteolíticos (IE = 6,6, respectivamente. Este estudo revelou alguns isolados de rizóbia nativos da Amazônia Central como fontes promissoras de enzimas de importância industrial para uso biotecnológico.Legumes enrich the soil by contributing nitrogen through symbiotic biological nitrogen fixation by rhizobia bacteria. However, very little is known about the extracellular enzymatic profile of these microorganisms. In this context, the production of extracellular hydrolytic enzymes by indigenous strains of rhizobia in Central Amazonia was evaluated. This screening constitutes the first step in selecting indigenous microorganisms that are

  20. Influência da coleta, da produção e da estocagem na qualidade dos concentrados de plaquetas Influence of collection, preparation and storage on the quality of platelet concentrates

    Directory of Open Access Journals (Sweden)

    Maria Aparecida V. Tostes

    2008-10-01

    Full Text Available Como o controle de qualidade dos concentrados de plaquetas (CP, feito na data de seu vencimento, não possibilita distinguir o momento e o procedimento que determina a eventual redução de sua qualidade, decidimos investigar, separadamente, a influência da coleta, da produção e da estocagem sobre a qualidade deste hemocomponente. Foram avaliados, em 33 CP randômicos, diariamente, durante cinco dias, os seguintes parâmetros: a agregação, o número de plaquetas e leucócitos, a pO2 e pCO2, o pH, sódio e potássio, a presença de swirling, grumos, hemácias e lipemia e cultura para bactérias. Observamos maior queda da agregação plaquetária com pares de agonistas durante a produção dos CP (de 99,4% para 59,8%, pAs quality control of platelet concentrates obtained at the expiration date does not distinguish between the different stages that may cause reductions in quality, such as collection and storage, we decided to separately investigate the influence of collection, processing and storage on the quality of these blood components. This study evaluated 33 random platelet concentrates daily for five days for the following parameters: aggregation, number of platelets and leukocytes, PO2 and PCO2, pH, sodium and potassium, the presence of swirling, platelet clots, red blood cells and lipemia, and bacteria culture. We observed a greater decrease in platelet aggregation with pairs of agonists during the production of platelet concentrates (from 99.4% to 59.8%, p<0.05, followed by a gradual drop during storage reaching 40.4% on day five. During storage the following were also observed: 1. a gradual drop of platelet concentration (p<0.05 although the values always remained higher than 5x1010/70 mL; 2. a decrease in leukocyte concentration (p<0.05; 3. increases in pO2 and decreases in pCO2 (p<0.05; 4. increase in the pH (p<0.05 from day 4 and in concentrations of sodium and potassium (in general p<0.05; 5. swirling in all platelet

  1. L-glutamate released from activated microglia downregulates astrocytic L-glutamate transporter expression in neuroinflammation: the ‘collusion’ hypothesis for increased extracellular L-glutamate concentration in neuroinflammation

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    Takaki Junpei

    2012-12-01

    Full Text Available Abstract Background In the central nervous system, astrocytic L-glutamate (L-Glu transporters maintain extracellular L-Glu below neurotoxic levels, but their function is impaired with neuroinflammation. Microglia become activated with inflammation; however, the correlation between activated microglia and the impairment of L-Glu transporters is unknown. Methods We used a mixed culture composed of astrocytes, microglia, and neurons. To quantify L-Glu transporter function, we measured the extracellular L-Glu that remained 30 min after an application of L-Glu to the medium (the starting concentration was 100 μM. We determined the optimal conditions of lipopolysaccharide (LPS treatment to establish an inflammation model without cell death. We examined the predominant subtypes of L-Glu transporters and the changes in the expression levels of these transporters in this inflammation model. We then investigated the role of activated microglia in the changes in L-Glu transporter expression and the underlying mechanisms in this inflammation model. Results Because LPS (10 ng/mL, 72 h caused a significant increase in the levels of L-Glu remaining but did not affect cell viability, we adopted this condition for our inflammation model without cell death. GLAST was the predominant L-Glu transporter subtype, and its expression decreased in this inflammation model. As a result of their release of L-Glu, activated microglia were shown to be essential for the significant decrease in L-Glu uptake. The serial application of L-Glu caused a significant decrease in L-Glu uptake and GLAST expression in the astrocyte culture. The hemichannel inhibitor carbenoxolone (CBX inhibited L-Glu release from activated microglia and ameliorated the decrease in GLAST expression in the inflammation model. In addition, the elevation of the astrocytic intracellular L-Glu itself caused the downregulation of GLAST. Conclusions Our findings suggest that activated microglia trigger the

  2. Monitoring In Vivo Changes in Tonic Extracellular Dopamine Level by Charge-Balancing Multiple Waveform Fast-Scan Cyclic Voltammetry.

    Science.gov (United States)

    Oh, Yoonbae; Park, Cheonho; Kim, Do Hyoung; Shin, Hojin; Kang, Yu Min; DeWaele, Mark; Lee, Jeyeon; Min, Hoon-Ki; Blaha, Charles D; Bennet, Kevin E; Kim, In Young; Lee, Kendall H; Jang, Dong Pyo

    2016-11-15

    Dopamine (DA) modulates central neuronal activity through both phasic (second to second) and tonic (minutes to hours) terminal release. Conventional fast-scan cyclic voltammetry (FSCV), in combination with carbon fiber microelectrodes, has been used to measure phasic DA release in vivo by adopting a background subtraction procedure to remove background capacitive currents. However, measuring tonic changes in DA concentrations using conventional FSCV has been difficult because background capacitive currents are inherently unstable over long recording periods. To measure tonic changes in DA concentrations over several hours, we applied a novel charge-balancing multiple waveform FSCV (CBM-FSCV), combined with a dual background subtraction technique, to minimize temporal variations in background capacitive currents. Using this method, in vitro, charge variations from a reference time point were nearly zero for 48 h, whereas with conventional background subtraction, charge variations progressively increased. CBM-FSCV also demonstrated a high selectivity against 3,4-dihydroxyphenylacetic acid and ascorbic acid, two major chemical interferents in the brain, yielding a sensitivity of 85.40 ± 14.30 nA/μM and limit of detection of 5.8 ± 0.9 nM for DA while maintaining selectivity. Recorded in vivo by CBM-FSCV, pharmacological inhibition of DA reuptake (nomifensine) resulted in a 235 ± 60 nM increase in tonic extracellular DA concentrations, while inhibition of DA synthesis (α-methyl-dl-tyrosine) resulted in a 72.5 ± 4.8 nM decrease in DA concentrations over a 2 h period. This study showed that CBM-FSCV may serve as a unique voltammetric technique to monitor relatively slow changes in tonic extracellular DA concentrations in vivo over a prolonged time period.

  3. Extracellular polymers of ozonized waste activated sludge.

    Science.gov (United States)

    Liu, J C; Lee, C H; Lai, J Y; Wang, K C; Hsu, Y C; Chang, B V

    2001-01-01

    Effect of ozonation on characteristics of waste activated sludge was investigated in the current study. Concentrations of cell-bound extracellular polymers (washed ECPs) did not change much upon ozonation, whereas the sum of cell-bound and soluble extracellular polymers (unwashed ECPs) increased with increasing ozone dose. Washed ECPs in original sludge as divided by molecular weight distribution was 39% 10,000 Da (high MW). It was observed that the low-MW fraction decreased, and the high-MW fraction increased in ozonized sludge. The unwashed ECPs were characterized as 44% in low MW, 30% in medium MW, and 26% in high MW. Both low-MW and medium-MW fractions of unwashed ECPs decreased while high-MW fraction increased in ozonized sludge. The dewaterability of ozonized sludge, assessed by capillary suction time (CST) and specific resistance to filtration (SRF), deteriorated with ozone dose. The optimal dose of cationic polyelectrolyte increased with increasing ozone dose. The production rate and the accumulated amount of methane gas of ozonized sludge were also higher.

  4. Proteinograma sérico de bovinos da raça Curraleir Serum protein concentration in Curraleiro bovine breed

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    R.S. Juliano

    2009-06-01

    Full Text Available Estudou-se o perfil eletroforético das proteínas séricas de bovinos sadios da raça Curraleiro por meio da técnica de eletroforese em gel de acrilamida contendo dodecil sulfato de sódio. Utilizaram-se amostras de soro sanguíneo de 228 bovinos da raça Curraleiro, 51 machos e 177 fêmeas, com idades entre sete meses e 12 anos, pertencentes a dois rebanhos localizados nos Estados de Goiás e Tocantins. Foram quantificadas proteína total e concentração plasmática de fibrinogênio. Verificaram-se variações nas concentrações das diferentes frações proteicas. Foram detectadas 26 proteínas e identificadas 10 delas. A ceruloplasmina esteve ausente em 78,1% dos indivíduos, e a α-antitripsina não foi detectada em nenhum animal. Proteína total, globulina, IgA, IgG e fibrinogênio aumentaram com a idade e houve correlação positiva entre os níveis séricos de haptoglobina e α1-glicoproteína ácida.The eletrophoretic serum protein profile in healthy Curraleiro bovine breed was studied by dodecyl sulphate-polyacrylamide gel electrophoresis. A total of 228 serum samples from Curraleiro cattle, being 51 males and 177 females were analyzed. They were from seven month to 12-year-old and were raised in two farms of Goiás and Tocantins states. Total protein and plasma fibrinogen quantification were performed. It was possible to verify variation in proteins fractions concentration. Twenty-six proteins were detected and ten of them were identified. Ceruloplasmin was absente in 78,10% of animals and α-antitrypsin was not detected. The total protein, globulin, IgA, IgG, and fibrinogen increased with age and there was a positive correlaction between haptoglobin and α1-acid glycoprotein.

  5. Secretion of five extracellular enzymes by strains of chromoblastomycosis agents Secreção de cinco enzimas extracelulares por amostras de agentes da cromoblastomicose

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    Thais Furtado de Souza

    2008-10-01

    Full Text Available The gelatinase, urease, lipase, phospholipase and DNase activities of 11 chromoblastomycosis agents constituted by strains of Fonsecaea pedrosoi, F. compacta, Phialophora verrucosa, Cladosporium carrionii, Cladophialophora bantiana and Exophiala jeanselmei were analyzed and compared. All strains presented urease, gelatinase and lipase activity. Phospholipase activity was detected only on five of six strains of F. pedrosoi. DNase activity was not detected on the strains studied. Our results indicate that only phospholipase production, induced by egg yolk substrate, was useful for the differentiation of the taxonomically related species studied, based on their enzymatic profile.As atividades gelatinase, urease, lipase, fosfolipase e DNase de 11 agentes da cromoblastomicose constituídos por amostras de Fonsecaea pedrosoi, F. compacta, Phialophora verrucosa, Cladosporium carrionii, Cladophialophora bantiana e Exophiala jeanselmei foram analisadas e comparadas. Todas as amostras apresentaram atividade urease, gelatinase e lipase. A atividade fosfolipase foi detectada apenas em cinco das seis amostras de F. pedrosoi. A atividade DNase não foi detectada nas amostras estudadas. Os resultados indicam que para a diferenciação entre espécies taxonomicamente relacionadas estudadas, baseado no seu perfil enzimático, apenas a produção de fosfolipase, induzida pelo substrato com gema de ovo, foi útil.

  6. Elevated tonic extracellular dopamine concentration and altered dopamine modulation of synaptic activity precede dopamine loss in the striatum of mice overexpressing human α-synuclein.

    Science.gov (United States)

    Lam, Hoa A; Wu, Nanping; Cely, Ingrid; Kelly, Rachel L; Hean, Sindalana; Richter, Franziska; Magen, Iddo; Cepeda, Carlos; Ackerson, Larry C; Walwyn, Wendy; Masliah, Eliezer; Chesselet, Marie-Françoise; Levine, Michael S; Maidment, Nigel T

    2011-07-01

    Overexpression or mutation of α-synuclein (α-Syn), a protein associated with presynaptic vesicles, causes familial forms of Parkinson's disease in humans and is also associated with sporadic forms of the disease. We used in vivo microdialysis, tissue content analysis, behavioral assessment, and whole-cell patch clamp recordings from striatal medium-sized spiny neurons (MSSNs) in slices to examine dopamine transmission and dopaminergic modulation of corticostriatal synaptic function in mice overexpressing human wild-type α-Syn under the Thy1 promoter (α-Syn mice). Tonic striatal extracellular dopamine and 3-methoxytyramine levels were elevated in α-Syn mice at 6 months of age, prior to any reduction in total striatal tissue content, and were accompanied by an increase in open-field activity. Dopamine clearance and amphetamine-induced dopamine efflux were unchanged. The frequency of MSSN spontaneous excitatory postsynaptic currents (sEPSCs) was lower in α-Syn mice. Amphetamine reduced sEPSC frequency in wild types (WTs) but produced no effect in α-Syn mice. Furthermore, whereas quinpirole reduced and sulpiride increased sEPSC frequency in WT mice, they produced the opposite effects in α-Syn mice. These observations indicate that overexpression of α-Syn alters dopamine efflux and D2 receptor modulation of corticostriatal glutamate release at a young age. At 14 months of age, the α-Syn mice presented with significantly lower striatal tissue dopamine and tyrosine hydroxylase content relative to WT littermates, accompanied by an L-DOPA-reversible sensory motor deficit. Together, these data further validate this transgenic mouse line as a slowly progressing model of Parkinson's disease and provide evidence for early dopamine synaptic dysfunction prior to loss of striatal dopamine. Copyright © 2011 Wiley-Liss, Inc.

  7. Effect of concentrating and exposing the bioluminescent bacteria to the non-luminescent allo-bacterial extracellular products on their luminescence

    Digital Repository Service at National Institute of Oceanography (India)

    Ravindran, J.; Priya, G.G.; Kannapiran, E.

    of cell-cell physical contact will be high. In this study, the physical proximity was artificially enhanced between cells and the effect on luminescence in the concentrated cells in the normal culture medium and in the presence of other non-bacterial cell...

  8. Production, purification and application of extracellular chitinase from Cellulosimicrobium cellulans 191 Produção, purificação e aplicação da quitinase extracelular de Cellulosimicrobium cellulans 191

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    Luciana F. Fleuri

    2009-09-01

    Full Text Available This study concerned the production, purification and application of extracellular chitinase from Cellulosimicrobium cellulans strain 191. In shaken flasks the maximum yield of chitinase was 6.9 U/mL after 72 h of cultivation at 25ºC and 200 rpm. In a 5 L fermenter with 1.5 vvm aeration, the highest yield obtained was 4.19 U/mL after 168 h of fermentation at 25ºC and 200 rpm, and using 3 vvm, it was 4.38 U/mL after 144 h of fermentation. The chitinase (61 KDa was purified about 6.65 times by Sepharose CL 4B 200 gel filtration with a yield of 46.61%. The purified enzyme was able to lyse the cell walls of some fungi and to form protoplasts.O presente estudo visou a produção, purificação e aplicação da quitinase extracelular da linhagem Cellulosimicrobium cellulans 191. A maior produção de quitinase em frascos agitados foi 6,9 U/mL após 72 h de fermentação a 25ºC e 200 rpm. Em fermentador de 5 L utilizando aeração de 1,5 vvm, a maior atividade da enzima foi 4,19 U/mL após 168 h de fermentação a 25ºC e 200 rpm; e com 3 vvm, foi obtido 4,38 U/mL após 144 h de fermentação. A quitinase (61 KDa foi purificada cerca de 6,65 vezes em coluna de filtração em gel Sepharose CL 4B 200 com um rendimento de 46,61%. A enzima purificada foi capaz de lisar a parede celular de alguns fungos e formar protoplastos.

  9. Effect of concentrating and exposing the bioluminescent bacteria to the non-luminescent allo-bacterial extracellular products on their luminescence.

    Science.gov (United States)

    Ravindran, J; Geetha Priya, G; Kannapiran, E

    2011-01-01

    Bioluminescence is a biochemical process occurring in many organisms. Bacterial bioluminescence has been investigated extensively that lead to many applications of such knowledge. Quorum sensing in the bioluminescent bacteria is a chemical signal process to recognize the strength of its own population to start luminescence in harmony. There is a mechanism in these bacteria to also recognize inter-species strength. When there is a higher number of these bacteria, the possibility and frequency of cell-cell physical contact will be high. In this study, the physical proximity was artificially enhanced between cells and the effect on luminescence in the concentrated cells in the normal culture medium and in the presence of other non-bacterial cell-free supernatants was investigated. The role of such physical contact in the quorum sensing in the bioluminescence is not known. Increase in the luminescence of V. fischeri when concentrated shows that the presence of physical proximity facilitates the quorum sensing for their bioluminescence.

  10. Efeito da criopreservação e/ou da descelularização na matriz extracelular de condutos valvados porcinos Effects of cryopreservation and/or decellularization on extracellular matrix of porcine valves

    Directory of Open Access Journals (Sweden)

    Luciana Cristina Ferretti de Nazareno Wollmann

    2011-09-01

    Full Text Available O objetivo desse estudo foi avaliar a morfologia de valvas pulmonares porcinas criopreservadas e/ou descelularizadas para determinar uma solução que remova as células, sem promover danos à matriz extracelular. Valvas pulmonares porcinas foram incubadas por 24h em soluções de deoxicolato de sódio 1% e de dodecil sulfato de sódio 0,1% e 0,3%, com ou sem criopreservação adicional. A avaliação foi feita com microscopia óptica (hematoxilina eosina, orceína acética ou Gomori e por morfometria. A efetividade das soluções foi variável, mas os melhores resultados foram obtidos com enxertos frescos descelularizados com dodecil sulfato de sódio 0,1%.The objective of this study was to evaluate the morphology of decelluarized and/or cryopreserved porcine pulmonary valves, to determine a solution capable of completely remove the cells without damaging the extracellular matrix. Porcine pulmonary valves were incubated for 24 hs in sodium deoxicholate 1% or sodium dodecyl sulfate 0.1 and 0.3%, with or without associated cryopreservation. Evaluation was done with optical microscopy (Hematoxilin-Eosin, Acetic Orcein and Gomori and with morphometric analysis. The effectiviness of the solutions was variable, but the best results were obtained with the sodium dodecyl sulfate solution 0.1%.

  11. Expressão imuno-histoquímica de proteínas da matriz extracelular em cistos odontogênicos calcificantes Immunohistochemical expression of extracellular matrix proteins in calcifying odontogenic cyst

    Directory of Open Access Journals (Sweden)

    Rosilene Calazans Soares

    2004-10-01

    Full Text Available INTRODUÇÃO: O cisto odontogênico calcificante (COC é uma lesão odontogênica de natureza benigna considerada por alguns autores como uma lesão exclusivamente cística, enquanto outros admitem uma contraparte neoplásica benigna. Vários estudos têm pesquisado a natureza das células fantasmas características do COC, porém permanece obscuro o conhecimento sobre a expressão dos constituintes da matriz extracelular (MEC nessa lesão. OBJETIVO: Realizar uma avaliação imuno-histoquímica da expressão de proteínas constituintes da MEC (fibronectina, tenascina e colágeno I em espécimes de COCs, a fim de verificar se há diferenças significativas em tal expressão ou se esses padrões representam um espectro da mesma entidade. MATERIAL E MÉTODOS: Foram utilizados dez casos de COCs, representados por cinco do tipo unicístico simples, três do tipo produtor de odontoma e dois com proliferação ameloblastomatosa, que foram submetidos à técnica imuno-histoquímica da estreptoavidina-biotina com anticorpos monoclonais anti-fibronectina, anti-tenascina e anti-colágeno I. RESULTADOS: Verificou-se que houve uma expressão variável das proteínas pesquisadas, tanto entre as lesões do mesmo grupo, como entre os três grupos estudados, sendo notável a reatividade para os três anticorpos apresentada pelas células fantasmas. CONCLUSÃO: Não foi possível observar um padrão de marcação que denotasse diferenças entre o tipo unicístico simples, o produtor de odontoma e o com proliferação ameloblastomatosa. Esse achado reforça a visão de que os vários tipos histológicos do COC podem, simplesmente, representar espectros histológicos diferentes de uma só entidade com comportamento biológico semelhante.BACKGROUND: The calcifying odontogenic cyst (COC is an odontogenic lesion of benign nature considered by some authors as an exclusively cystic lesion, while others admit a benign neoplastic counterpart. Some studies have studied the

  12. The tyrosyl-tRNA synthetase like gene located in the tyramine biosynthesis cluster of Enterococcus durans is transcriptionally regulated by tyrosine concentration and extracellular pH

    Directory of Open Access Journals (Sweden)

    Linares Daniel M

    2012-02-01

    Full Text Available Abstract Background The tyramine producer Enterococcus durans IPLA655 contains all the necessary genes for tyramine biosynthesis, grouped in the TDC cluster. This cluster includes tyrS, an aminoacyl-tRNA synthetase like gene. Results This work shows that tyrS was maximally transcribed in absence of tyrosine at acidic pH, showing a greater than 10-fold induction in mRNA levels over levels occurring in presence of tyrosine. Mapping of the tyrS transcriptional start site revealed an unusually long untranslated leader region of 322 bp, which displays the typical features of the T box transcriptional attenuation mechanism. The tyrosine concentration regulation of tyrS was found to be mediated by a transcription antitermination system, whereas the specific induction at acidic pH was regulated at transcription initiation level. Conclusions The expression of the tyrS gene present in the TDC cluster of E. durans is transcriptionally regulated by tyrosine concentration and extracelular pH. The regulation is mediated by both an antitermination system and the promoter itself.

  13. Calibração da Reflectometria no Domínio do Tempo (TDR para a estimativa da concentração da solução no solo Time Domain Reflectometry (TDR calibration for estimating soil solution concentration

    Directory of Open Access Journals (Sweden)

    Claudinei F. Souza

    2006-04-01

    Full Text Available A Reflectometria no Domínio do Tempo (TDR é um método confiável para medidas in situ da umidade e da concentração da solução no mesmo volume de solo. Entretanto, a interpretação precisa da medida de condutividade elétrica do solo (e umidade do solo pode requerer uma curva de calibração específica. O objetivo principal deste ensaio foi estabelecer um procedimento de calibração para usar a TDR no cálculo de concentrações de nitrato de potássio (KNO3 em solução do solo. Uma equação que relaciona a condutividade elétrica medida pela TDR e a concentração de KNO3 foram encontradas viabilizando o uso da técnica da TDR na estimativa da umidade e da concentração da solução do solo para o manejo eficiente da fertirrigação.Time Domain Reflectometry (TDR is a reliable method for in-situ measurements of the humidity and the solution concentration at the same soil volume. Accurate interpretation of electrical conductivity (and soil humidity measurements may require a specific calibration curve. The primary goal of this work was to establish a calibration procedure for using TDR to estimate potassium nitrate concentrations (KNO3 in soil solution. An equation relating the electrical conductivity measured by TDR and KNO3 concentration was established enabling the use of TDR technique to estimate soil water content and nitrate concentration for efficient fertigation management.

  14. Spectroscopic Characterization of Extracellular Polymeric Substances from Escherichia coli and Serratia marcescens: Suppression using Sub-Inhibitory Concentrations of Bismuth Thiols

    Energy Technology Data Exchange (ETDEWEB)

    Badireddy, Appala R.; Korpol, Bhoom Reddy; Chellam, Shankararaman; Gassman, Paul L.; Engelhard, Mark H.; Lea, Alan S.; Rosso, Kevin M.

    2008-10-21

    Free and capsular EPS produced by Escherichia coli and Serratia marcescens were characterized in detail using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Total EPS production decreased upon treatment with sub-inhibitory concentrations of lipophilic bismuth thiols (bismuth dimercaptopropanol, BisBAL; bismuth ethanedithiol, BisEDT; and bismuth pyrithione, BisPYR), BisBAL being most effective. Bismuth thiols also influenced acetylation and carboxylation of polysaccharides in EPS from S. marcescens. Extensive homology between EPS samples in the presence and absence of bismuth was observed with proteins, polysaccharides, and nucleic acids varying predominantly only in the total amount expressed. Second derivative analysis of the amide I region of FTIR spectra revealed decreases in protein secondary structures in the presence of bismuth thiols. Hence, anti-fouling properties of bismuth thiols appear to originate in their ability to suppress O-acetylation and protein secondary structures in addition to total EPS secretion.

  15. Medidas da concentração de oxigênio dissolvido na superfície da água Measurements of dissolved oxygen concentration at water surface

    Directory of Open Access Journals (Sweden)

    Johannes Gerson Janzen

    2008-09-01

    Full Text Available A transferência de gases através da interface ar-água é um processo importante para ciclos climáticos de grande escala e para sistemas ambientais menores como rios, lagos, córregos e estações de tratamento de esgoto. Para avançar no entendimento dos princípios básicos envolvidos no fenômeno é necessária a utilização de técnicas e aparatos experimentais adequados. Neste estudo, foram realizadas medidas de concentração através da utilização de micro sonda de oxigênio, em tanque de grade oscilante. A dimensão do elemento sensor da micro sonda é da ordem de alguns micra. Os resultados demonstram a possibilidade de medir, sob condições turbulentas controladas similares às encontradas no ambiente, as flutuações de concentração de oxigênio no interior da camada limite existente imediatamente abaixo da interface ar-água.Gas transfer across the air-water interface is an important process for large-scale climate cycles as well as smaller environmental systems such as rivers, lakes, streams, and wastewater treatment basins. To improve the understanding of the basic principles involved in this phenomenon it is necessary to use suitable apparatus and experimental techniques. In this study, a microprobe has been used for measurements of oxygen concentration in an oscillating-grid tank. The microprobe has tip dimensions of the order of a few microns. The results demonstrate that it is feasible to measure, under controlled turbulence conditions that are representative for environmental situations, the fluctuating oxygen concentrations that take place in a boundary layer below the air-water interface.

  16. Concentração da solução nutritiva no crescimento da planta, na produtividade e na qualidade de frutas do morangueiro Nutrient solution concentration on plant growth, fruit yield and quality of strawberry crop

    Directory of Open Access Journals (Sweden)

    Jerônimo Luiz Andriolo

    2009-06-01

    Full Text Available O objetivo do trabalho foi determinar o efeito da concentração da solução nutritiva no crescimento da planta, na produtividade e na qualidade das frutas do morangueiro cultivado em sistema fechado de cultivo sem solo. Os tratamentos consistiram de cinco soluções nutritivas com condutividades elétricas (CE de 0,9; 1,8; 2,5; 3,2 e 3,8dS m-1 no delineamento experimental inteiramente casualizado, com três repetições. Foram determinados os seguintes parâmetros: a produtividade e a qualidade das frutas durante o período de produção e o crescimento da parte aérea e das raízes ao final do experimento. A produtividade, o tamanho das frutas e o crescimento da planta diminuíram com o aumento da concentração da solução nutritiva, enquanto a acidez titulável e o teor de sólidos solúveis totais aumentaram. A solução nutritiva com CE de 0,9dS m-1 reduz o crescimento da planta e maximiza a produtividade de frutas no cultivo sem solo do morangueiro, em sistema fechado.The objective of the research was to determine the effect of nutrient solution concentration on plant growth, fruit yield and quality of the strawberry crop grown in a closed hydroponic growing system. Treatments were five nutrient solutions at electrical conductivities (EC of 0.9; 1.8; 2.5; 3.2 and 3.8dS m-1, in a randomised experimental design with three replications. Fruit yield and quality during the harvest period and shoot and root growth at the end of the experiment were determined. Fruit yield, fruit size and plant growth were reduced by increasing nutrient solution concentration, whereas titratable acidity and total soluble solids were increased. The EC of 0.9dS m-1 reduces plant growth and maximizes fruit yield of the strawberry crop in the closed soilless growing system.

  17. Comparison of blood serum selenium concentrations from elderly population living in Sao Paulo city and literature data; Comparacao da concentracao de selenio em soro sanguineo da populacao de idosos da cidade de Sao Paulo com os dados da literatura

    Energy Technology Data Exchange (ETDEWEB)

    Saiki, Mitiko; Alves, Edson R.; Vasconcellos, Marina B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica]. E-mail: mitiko@ipen.br; Sumita, Nairo M.; Jaluul, Omar; Jacob Filho, Wilson [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina

    2005-07-01

    Selenium is an essential nutrient of fundamental importance to human biology. This element is a component of the enzyme glutathione peroxidase that avoids the formation of free radicals protecting the organism against the oxidative damage. The Se concentrations in serum vary from one part of the world to another and this fact has been satisfactorily explained as a consequence of different Se intakes of the population. The main objective of this paper was the determination of serum Se concentrations in healthy elderly population included in a program for 'Successful Ageing' of the Hospital das Clinicas, Sao Paulo University Medical School. The blood samples were collected after a 12 h fast from 32 subjects aged 60 to 87 years. The blood was centrifuged after completely clotted and 4.0 mL of serum were freeze.dried for Se determination using neutron activation analysis. The serum samples and Se standard were irradiated for 16 h under a thermal neutron flux of de 5 x 10{sup 12} n cm{sup -}'2 s{sup -1} at the IEA-R1 nuclear reactor. Se was determined by measuring the gamma activity of {sup 75}Se using an HGe detector coupled to a gamma ray spectrometer. The mean value of (0.92{+-}0.07) {mu}mol L{sup -1} was obtained for serum Se concentration. This value is within the data used as reference values in clinical laboratories and those published in literature. Results obtained for certified reference materials NIST 1566b Oyster Tissue and NIST 1577b Bovine Liver showed good precision and agreed with the certified values. The relative standard deviation of the results was lower than 4.8 % and relative error lower than 0.97 %. Detection limit value obtained for serum Se determination was 0.003 {mu}mol L-1. (author)

  18. DA-6034 Induces [Ca(2+)]i Increase in Epithelial Cells.

    Science.gov (United States)

    Yang, Yu-Mi; Park, Soonhong; Ji, Hyewon; Kim, Tae-Im; Kim, Eung Kweon; Kang, Kyung Koo; Shin, Dong Min

    2014-04-01

    DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces Ca(2+) signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in Ca(2+) signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated Ca(2+)-activated Cl(-) channels (CaCCs) and increased intracellular calcium concentrations ([Ca(2+)]i) in primary cultured human conjunctival cells. DA-6034 also increased [Ca(2+)]i in mouse salivary gland cells and human corneal epithelial cells. [Ca(2+)]i increase of DA-6034 was dependent on the Ca(2+) entry from extracellular and Ca(2+) release from internal Ca(2+) stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate (IP3) pathway and lysosomal Ca(2+) stores. These results suggest that DA-6034 induces Ca(2+) signaling via extracellular Ca(2+) entry and RyRs-sensitive Ca(2+) release from internal Ca(2+) stores in epithelial cells.

  19. Extracellular DNA metabolism in Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Scott eChimileski

    2014-02-01

    Full Text Available Extracellular DNA is found in all environments and is a dynamic component of the micro-bial ecosystem. Microbial cells produce and interact with extracellular DNA through many endogenous mechanisms. Extracellular DNA is processed and internalized for use as genetic information and as a major source of macronutrients, and plays several key roles within prokaryotic biofilms. Hypersaline sites contain some of the highest extracellular DNA con-centrations measured in nature–a potential rich source of carbon, nitrogen and phosphorus for halophilic microorganisms. We conducted DNA growth studies for the halophilic archaeon Haloferax volcanii DS2 and show that this model Halobacteriales strain is capable of using exogenous double-stranded DNA as a nutrient. Further experiments with varying medium composition, DNA concentration and DNA types revealed that DNA is utilized primarily as a phosphorus source, that growth on DNA is concentration-dependent and that DNA isolated from different sources is metabolized selectively, with a bias against highly divergent methylated DNA sources. Additionally, fluorescence microscopy experiments showed that labeled DNA colocalized with Haloferax volcanii cells. The gene Hvo_1477 was also identified using a comparative genomic approach as a factor likely to be involved in extracellular DNA processing at the cell surface, and deletion of Hvo_1477 created an H. volcanii strain deficient in its ability to grow on extracellular DNA. Widespread distribution of Hvo_1477 homologs in archaea suggests metabolism of extracellular DNA may be of broad ecological and physiological relevance in this domain of life.

  20. Efeito da concentração da solução nutritiva no crescimento da alface em cultivo hidropônico-sistema NFT Effects of the concentration of nutrient solution on lettuce growth in hydroponics-NFT system

    Directory of Open Access Journals (Sweden)

    Nilton Nélio Cometti

    2008-06-01

    Full Text Available Foi avaliado o crescimento da alface (Lactuca sativa L. cv 'Vera' em um sistema hidropônico NFT com diferentes concentrações da solução nutritiva. O experimento foi realizado em casa de vegetação de abril a maio de 2000, na UFRRJ, Seropédica (RJ. Os tratamentos constaram de quatro soluções nutritivas, diferentes quanto à concentração de macronutrientes: 100; 50; 25 e 12,5% da concentração original proposta por Furlani (1997. A produção de massa seca (parte comercial em solução nutritiva a 50% da concentração original, e condutividade elétrica em torno de 0,98 dS m-1, foi semelhante à solução a 100% da força iônica. As produções obtidas com 100 e 50% da força iônica estiveram dentro da faixa de 90% da produção máxima, calculada em 75±1% da força iônica da solução nutritiva, simulada por equação de regressão. Entretanto, o uso de concentrações menores resultou em redução no crescimento de 50% com a solução a 25% e 80% com a solução a 12,5% da força iônica, nas condições de luz e temperatura em que o experimento foi conduzido. A redução da concentração da solução nutritiva permite uma economia de pelo menos 50% no custo da solução nutritiva básica, reduzindo-se a solução inicial para 1,00 dS m-1, sem comprometer a produtividade.The growth of lettuce (Lactuca sativa L. cv 'Vera' was evaluated in a NFT hydroponic system with different nutrient solution concentrations. An experiment was carried out in a greenhouse from April to May, 2000 in Rio de Janeiro State, Brazil. Four treatments were used differing in macro nutrient concentration: 100; 50; 25 and 12.5% of the original concentration of the solution proposed by Furlani (1997. Using 50% of the original concentration with electric conductivity around 0,98 dS m-1, plants produced the same shoot dry mass as using 100% of the ionic strength. In this trial, the phytomass yield using 100 and 50% of the ionic strength was within the range

  1. Metal concentration on soils of urban parks at Sao Paulo, Brazil. 3. Parque da Aclimacao; Concentracao de metais em solos de parques urbanos em Sao Paulo. 3. Parque da Aclimacao

    Energy Technology Data Exchange (ETDEWEB)

    Pavese, Arthur C. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias]. E-mail: pavese@terra.com.br; Figueiredo, Ana Maria G.; Camargo, Sonia P.; Gumiero, Felipe C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: anamaria@ipen.br; Enzweiler, Jacinta [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)]. E-mail: jacinta@ige.unicamp.br; Milian, Felix Mas [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil)]. E-mail: felixmasmilian@yahoo.com.br

    2007-07-01

    This paper determines the concentration of As, Ba, Zn, Sb, Se, Co, Cf, Cu and Pb on samples of superficial soils (0-5 cm and 0-20 cm) at the Parque da Aclimacao, Sao Paulo downtown. The metal analyses were performed by using instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF). The obtained results for the Zn were higher than the values considered as reference for soils at Sao Paulo, in accordance with the Sao Paulo Environmental Protection Agency (CETESB), but were lower than the prevention values. For the As, Ba, Cr and Sb, the results have shown concentration higher than the values of reference reported by the CETESB. (author)

  2. Specific inhibition of kynurenate synthesis enhances extracellular dopamine levels in the rodent striatum

    Science.gov (United States)

    Amori, L; Wu, H.-Q.; Marinozzi, M; Pellicciari, R; Guidetti, P; Schwarcz, R

    2011-01-01

    Fluctuations in the endogenous levels of kynurenic acid (KYNA), a potent α7 nicotinic and NMDA receptor antagonist, affect extracellular dopamine (DA) concentrations in the rat brain. Moreover, reductions in KYNA levels increase the vulnerability of striatal neurons to NMDA receptor-mediated excitotoxic insults. We now assessed the role of a key KYNA-synthesizing enzyme, kynurenine aminotransferase II (KAT II), in these processes in the rodent striatum, using KAT II KO mice—which have reduced KYNA levels—and the selective KAT II inhibitor (S)-4-(ethylsulfonyl)benzoylalanine (S-ESBA) as tools. S-ESBA (applied by reverse dialysis) raised extracellular DA levels in the striatum of KYNA-deficient mice threefold and caused a much larger, 15-fold increase in wild-type mice. In the rat striatum, S-ESBA produced a 35% reduction in extracellular KYNA, which was accompanied by a 270% increase in extracellular DA. The latter effect was abolished by co-infusion of 100 nM KYNA. Intrastriatal S-ESBA pre-treatment augmented the size of a striatal quinolinate lesion by 370%, and this potentiation was prevented by co-infusion of KYNA. In separate animals, acute inhibition of KAT II reduced the de novo synthesis of KYNA during an early excitotoxic insult without enhancing the formation of the related neurotoxic metabolites 3-hydroxykynurenine and quinolinate. Taken together, these results provide further support for the concept that KAT II is a critical determinant of functionally relevant KYNA fluctuations in the rodent striatum. PMID:19138730

  3. Extracellular calcium sensing and extracellular calcium signaling

    Science.gov (United States)

    Brown, E. M.; MacLeod, R. J.; O'Malley, B. W. (Principal Investigator)

    2001-01-01

    The cloning of a G protein-coupled extracellular Ca(2+) (Ca(o)(2+))-sensing receptor (CaR) has elucidated the molecular basis for many of the previously recognized effects of Ca(o)(2+) on tissues that maintain systemic Ca(o)(2+) homeostasis, especially parathyroid chief cells and several cells in the kidney. The availability of the cloned CaR enabled the development of DNA and antibody probes for identifying the CaR's mRNA and protein, respectively, within these and other tissues. It also permitted the identification of human diseases resulting from inactivating or activating mutations of the CaR gene and the subsequent generation of mice with targeted disruption of the CaR gene. The characteristic alterations in parathyroid and renal function in these patients and in the mice with "knockout" of the CaR gene have provided valuable information on the CaR's physiological roles in these tissues participating in mineral ion homeostasis. Nevertheless, relatively little is known about how the CaR regulates other tissues involved in systemic Ca(o)(2+) homeostasis, particularly bone and intestine. Moreover, there is evidence that additional Ca(o)(2+) sensors may exist in bone cells that mediate some or even all of the known effects of Ca(o)(2+) on these cells. Even more remains to be learned about the CaR's function in the rapidly growing list of cells that express it but are uninvolved in systemic Ca(o)(2+) metabolism. Available data suggest that the receptor serves numerous roles outside of systemic mineral ion homeostasis, ranging from the regulation of hormonal secretion and the activities of various ion channels to the longer term control of gene expression, programmed cell death (apoptosis), and cellular proliferation. In some cases, the CaR on these "nonhomeostatic" cells responds to local changes in Ca(o)(2+) taking place within compartments of the extracellular fluid (ECF) that communicate with the outside environment (e.g., the gastrointestinal tract). In others

  4. Capacidade da matriz extracelular da medula óssea de induzir proliferação de células mielóides in vitro no modelo de desnutrição protéica em camundongos Capacity of the extracellular matrix of the bone marrow to induce proliferation of myeloid cells in vitro in model of protein malnutrition in mice

    Directory of Open Access Journals (Sweden)

    Cidônia de Lourdes Vituri

    2008-09-01

    Full Text Available Este trabalho tem por objetivo verificar se a matriz extracelular (MEC obtida da medula óssea de camundongos com desnutrição protéica energética sustenta a sobrevivência, se induz proliferação de células mielóides, bem como avaliar a capacidade desta MEC de interagir com citocinas hematopoiéticas in vitro. Camundongos machos "Swiss" foram submetidos à desnutrição protéica (4% de caseína até que perdessem 20% do peso inicial e o grupo-controle foi mantido com uma dieta contendo 14% de caseína. A medula óssea foi extraída com tampão PBS suplementado com 1 mg de aprotinina/mL. Os ensaios de proliferação foram realizados com a linhagem mielóide FDC-P1, pelo método colorimétrico de redução do MTT. A MEC obtida tanto do grupo-controle como do desnutrido induziu proliferação celular in vitro. Os ensaios de interação foram realizados com IL-3 e GM-CSF na concentração de 10 ρg e 500 ρg/mL, que demonstraram efeito sinérgico e efeito regulatório, respectivamente. A MEC obtida de animais do grupo desnutrido quando submetida ao ensaio de ligação ao GM-CSF mostrou maior proliferação celular do que a MEC obtida de animais do grupo-controle (pThe aim of this study was to verify the capacity of the extracellular matrix (ECM obtained from bone marrow of malnourished mice to sustain survival and to induce the proliferation of myeloid cells. We also verified the capacity of the tests to interact with in vitro hematopoietic cytokines. Male "Swiss" mice were submitted to protein malnutrition with a diet content of '4% casein until they lost 20% of the original weight, while the group-control was kept with a diet content of 14% of casein. The bone marrow was extracted with 1.0 mg of aprotinin/mL in PBS. The proliferation tests were carried out with myeloid cell line FDCP-1, by the colorimetric method of reduction of the MTT. The obtained ECM from nourished and undernourished mice induced cellular proliferation invitro. Tests

  5. Insertion of tetracysteine motifs into dopamine transporter extracellular domains.

    Directory of Open Access Journals (Sweden)

    Deanna M Navaroli

    Full Text Available The neuronal dopamine transporter (DAT is a major determinant of extracellular dopamine (DA levels and is the primary target for a variety of addictive and therapeutic psychoactive drugs. DAT is acutely regulated by protein kinase C (PKC activation and amphetamine exposure, both of which modulate DAT surface expression by endocytic trafficking. In order to use live imaging approaches to study DAT endocytosis, methods are needed to exclusively label the DAT surface pool. The use of membrane impermeant, sulfonated biarsenic dyes holds potential as one such approach, and requires introduction of an extracellular tetracysteine motif (tetraCys; CCPGCC to facilitate dye binding. In the current study, we took advantage of intrinsic proline-glycine (Pro-Gly dipeptides encoded in predicted DAT extracellular domains to introduce tetraCys motifs into DAT extracellular loops 2, 3, and 4. [(3H]DA uptake studies, surface biotinylation and fluorescence microscopy in PC12 cells indicate that tetraCys insertion into the DAT second extracellular loop results in a functional transporter that maintains PKC-mediated downregulation. Introduction of tetraCys into extracellular loops 3 and 4 yielded DATs with severely compromised function that failed to mature and traffic to the cell surface. This is the first demonstration of successful introduction of a tetracysteine motif into a DAT extracellular domain, and may hold promise for use of biarsenic dyes in live DAT imaging studies.

  6. Extracellular Gd-CA

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Marckmann, Peter

    2008-01-01

    Until recently it was believed that extracellular gadolinium-based contrast agents were safe for both the kidneys and all other organs within the dose range up to 0.3 mmol/kg body weight. However, in 2006, it was demonstrated that some gadolinium-based contrast agents may trig the development of ...

  7. A Polysaccharide-Degrading Marine Bacterium Flammeovirga sp.MY04 and Its Extracellular Agarase System

    Institute of Scientific and Technical Information of China (English)

    HAN Wenjun; GU Jingyan; YAN Qiujie; LI Jungang; WU Zhihong; GU Qianqun; LI Yuezhong

    2012-01-01

    Bacteria of the genus Flammeovirga can digest complex polysaccharides(CPs),but no details have been reported regarding the CP depolymerases of these bacteria.MY04,an agarolytic marine bacterium isolated from coastal sediments,has been identified as a new member of the genus Flammeovirga.The MY04 strain is able to utilize multiple CPs as a sole carbon source and grows well on agarose,mannan,or xylan.This strain produces high concentrations of extracellular proteins (490mgL-1± 18.2 mgL-1liquid culture)that exhibit efficient and extensive degradation activities on various polysaccharides,especially agarose.These proteins have an activity of 310 U mg-1± 9.6 Umg-1 proteins.The extracellular agarase system(EAS)in the crude extracellular enzymes contains at least four agarose depolymerases,which are with molecular masses of approximately 30-70 kDa.The EAS is stable at a wide range of pH values(6.0-11.0),temperatures(0-50℃),and sodium chloride(NaCl)concentrations(0-0.9mol L-1).Two major degradation products generated from agarose by the EAS are identified to be neoagarotetraose and neoagarohexaose,suggesting that β-agarases are the major constituents of the MY04 EAS.These results suggest that the Flammeovirga strain MY04 and its polysaccharide-degradation system hold great promise in industrial applications.

  8. The origin, function, and diagnostic potential of RNA within extracellular vesicles present in human biological fluids

    OpenAIRE

    Taylor, Douglas D.; Gercel-Taylor, Cicek

    2013-01-01

    We have previously demonstrated that tumor cells release membranous structures into their extracellular environment, which are termed exosomes, microvesicles or extracellular vesicles depending on specific characteristics, including size, composition and biogenesis pathway. These cell-derived vesicles can exhibit an array of proteins, lipids and nucleic acids derived from the originating tumor. This review focuses of the transcriptome (RNA) of these extracellular vesicles. Based on current da...

  9. Extração da lignina e emprego da mesma em curvas de calibração para a mensuração da lignina em produtos vegetais Lignin extraction and its performance in calibration curves to determine lignin concentration in plants

    Directory of Open Access Journals (Sweden)

    Romualdo Shigueo Fukushima

    2000-10-01

    Full Text Available O objetivo deste experimento foi a extração da lignina e seu uso nas curvas de calibração para determinar a concentração de lignina em produtos vegetais. Dentre os métodos analíticos utilizados para a mensuração da lignina, pode-se mencionar o método "lignina solúvel em brometo de acetila - LSBA", no qual a lignina é solubilizada em uma solução de brometo de acetila a 25% em ácido acético glacial e, depois, lida no comprimento de onda a 280 nm. Entretanto, todo método espectrofotométrico requer o emprego de um padrão de referência confiável; neste experimento utilizou-se como padrão de referência a lignina da planta forrageira extraída com o emprego do próprio brometo de acetila. Quantificou-se a lignina presente em quatro amostras de forrageiras, em dois estádios de maturidade e, ainda, em duas amostras de madeiras, comparando-se os dados com outros dois métodos de determinação da lignina (lignina em detergente ácido - LDA e lignina permanganato de potássio - LPer. Os três métodos não foram concordantes entre si, sendo que, para praticamente todas as amostras, o método da LSBA mostrou valores mais elevados que os outros dois métodos. Para cada amostra analisada, foram confeccionados uma curva-padrão e um espectrograma na faixa de comprimento de luz de 240 a 320 nm. A análise dessas curvas e dos espectrogramas indicou diferenças qualitativas entre as amostras, em função não apenas da espécie botânica, mas também do estádio de maturidade da planta.The objective of this experiment was the extraction of lignin and its use in the calibration curves to determine lignin concentration in vegetable plants. Among the analytical methods for measuring lignin concentration, there is the "acetyl bromide soluble lignin -ABSL" method, were solubilized lignin in 25% solution of acetyl bromide in glacial acetic acid is read at 280 nm. However, any spectrophotometric method requires a reliable standard to which

  10. Regulation of Synaptic Transmission by Ambient Extracellular Glutamate

    OpenAIRE

    Featherstone, David E.; Scott A. Shippy

    2007-01-01

    Many neuroscientists assume that ambient extracellular glutamate concentrations in the nervous system are biologically negligible under nonpathological conditions. This assumption is false. Hundreds of studies over several decades suggest that ambient extracellular glutamate levels in the intact mammalian brain are ~0.5 to ~5 μM. This has important implications. Glutamate receptors are desensitized by glutamate concentrations significantly lower than needed for receptor activation; 0.5 to 5 μ...

  11. Extracellular ATP in the lymphohematopoietic system: P2Z purinoceptors and membrane permeabilization

    Directory of Open Access Journals (Sweden)

    Persechini P.M.

    1998-01-01

    Full Text Available The effects of extracellular nucleosides and nucleotides on many organs and systems have been recognized for almost 50 years. The effects of extracellular ATP (ATPo, UTPo, ADPo, and other agonists are mediated by P2 purinoceptors. One of the most dramatic effects of ATPo is the permeabilization of plasma membranes to low molecular mass solutes of up to 900 Da. This effect is evident in several cells of the lymphohematopoietic system and is supposed to be mediated by P2Z, an ATP4--activated purinoceptor. Here, we review some basic information concerning P2 purinoceptors and focus our attention on P2Z-associated phenomena displayed by macrophages. Using fluorescent dye uptake, measurement of free intracellular Ca2+ concentration and electrophysiological recordings, we elucidate some of the events that follow the application of ATP to the extracellular surface of macrophages. We propose a regulatory mechanism for the P2Z-associated permeabilization pore. The presence of P2 purinoceptors in cells of the lymphohematopoietic system makes them potential candidates to mediate immunoregulatory events

  12. O papel das proteínas da matriz extracelular e das metaloproteinases em carcinomas de cabeça e pescoço: uma atualização bibliográfica The role of matrix extracellular proteins and metalloproteinases in head and neck carcinomas: an updated review

    Directory of Open Access Journals (Sweden)

    Antonio L.A. Pereira

    2005-02-01

    Full Text Available Interações entre células neoplásicas e constituintes da matriz extracelular (MEC interferem fortemente no desenvolvimento tumoral, incluindo os localizados em cabeça e pescoço, pois influenciam a proliferação e sobrevivência celular, bem como a sua capacidade de migrar do sítio primário para outros tecidos e formar metástases. Essa migração celular é facilitada pela destruição parcial da MEC, a qual é realizada pelas metaloproteinases (MMPs, que representam uma família de mais de vinte endopeptidases, com atividade controlada pela expressão de inibidores específicos (TIMPs. Diversos estudos utilizando-se de marcadores para constituintes da MEC bem como pelas MMPs têm fornecido informações adicionais sobre o diagnóstico e prognóstico em carcinomas de cabeça e pescoço. Nesta revisão consideraremos o papel da MEC e das MMPs na progressão desses tumores, enfatizando que não somente a degradação proteolítica está envolvida neste processo, como também interações entre vários constituintes da MEC fornecem substrato para regulação e crescimento destes tumores.Interactions involving tumor cells and the extracellular matrix (ECM strongly influence tumor development, including head and neck tumors, affecting cell proliferation and survival as well as the ability to migrate beyond the original location into other tissues to form metastases. These cell migration is often facilitated by partial destruction of the surrounding ECM, which is catalyzed by matrix metalloproteinases (MMPs, a family of more than 20 endopeptidases that is controlled by regulated expression of specific inhibitors (TIMPs. Several studies of ECM and MMPs markers have provided additional diagnostic and prognostic information in head and neck carcinomas. In this review, we are considering the role of ECM and MMPs in tumor progression, emphasizing its proteolytic contributors to this process, and interactions between several members of ECM providing

  13. Extracellular Matrix Proteins

    Directory of Open Access Journals (Sweden)

    Linda Christian Carrijo-Carvalho

    2012-01-01

    Full Text Available Lipocalin family members have been implicated in development, regeneration, and pathological processes, but their roles are unclear. Interestingly, these proteins are found abundant in the venom of the Lonomia obliqua caterpillar. Lipocalins are β-barrel proteins, which have three conserved motifs in their amino acid sequence. One of these motifs was shown to be a sequence signature involved in cell modulation. The aim of this study is to investigate the effects of a synthetic peptide comprising the lipocalin sequence motif in fibroblasts. This peptide suppressed caspase 3 activity and upregulated Bcl-2 and Ki-67, but did not interfere with GPCR calcium mobilization. Fibroblast responses also involved increased expression of proinflammatory mediators. Increase of extracellular matrix proteins, such as collagen, fibronectin, and tenascin, was observed. Increase in collagen content was also observed in vivo. Results indicate that modulation effects displayed by lipocalins through this sequence motif involve cell survival, extracellular matrix remodeling, and cytokine signaling. Such effects can be related to the lipocalin roles in disease, development, and tissue repair.

  14. DA-9801 promotes neurite outgrowth via ERK1/2-CREB pathway in PC12 cells.

    Science.gov (United States)

    Won, Jong Hoon; Ahn, Kyong Hoon; Back, Moon Jung; Ha, Hae Chan; Jang, Ji Min; Kim, Ha Hyung; Choi, Sang-Zin; Son, Miwon; Kim, Dae Kyong

    2015-01-01

    In the present study, we examined the mechanisms underlying the effect of DA-9801 on neurite outgrowth. We found that DA-9801 elicits its effects via the mitogen-activated protein kinase (MEK) extracellular signal-regulated kinase (ERK)1/2-cAMP response element-binding protein (CREB) pathway. DA-9801, an extract from a mixture of Dioscorea japonica and Dioscorea nipponica, was reported to promote neurite outgrowth in PC12 cells. The effects of DA-9801 on cell viability and expression of neuronal markers were evaluated in PC12 cells. To investigate DA-9801 action, specific inhibitors targeting the ERK signaling cascade were used. No cytotoxicity was observed in PC12 cells at DA-9801 concentrations of less than 30 µg/mL. In the presence of nerve growth factor (NGF, 2 ng/mL), DA-9801 promoted neurite outgrowth and increased the relative mRNA levels of neurofilament-L (NF-L), a marker of neuronal differentiation. The Raf-1 inhibitor GW5074 and MEK inhibitor PD98059 significantly attenuated DA-9801-induced neurite outgrowth. Additionally, the MEK1 and MEK2 inhibitor SL327 significantly attenuated the increase in the percentage of neurite-bearing PC12 cells induced by DA-9801 treatment. Conversely, the selective p38 mitogen-activated protein kinase inhibitor SB203580 did not attenuate the DA-9801 treatment-induced increase in the percentage of neurite-bearing PC12 cells. DA-9801 enhanced the phosphorylation of ERK1/2 and CREB in PC12 cells incubated with and without NGF. Pretreatment with PD98059 blocked the DA-9801-induced phosphorylation of ERK1/2 and CREB. In conclusion, DA-9801 induces neurite outgrowth by affecting the ERK1/2-CREB signaling pathway. Insights into the mechanism underlying this effect of DA-9801 may suggest novel potential strategies for the treatment of peripheral neuropathy.

  15. Fibrotic remodeling of the extracellular matrix through a novel (engineered, dual-function antibody reactive to a cryptic epitope on the N-terminal 30 kDa fragment of fibronectin.

    Directory of Open Access Journals (Sweden)

    Maryada Sharma

    Full Text Available Fibrosis is characterized by excessive accumulation of scar tissue as a result of exaggerated deposition of extracellular matrix (ECM, leading to tissue contraction and impaired function of the organ. Fibronectin (Fn is an essential component of the ECM, and plays an important role in fibrosis. One such fibrotic pathology is that of proliferative vitreoretinopathy (PVR, a sight-threatening complication which develops as a consequence of failure of surgical repair of retinal detachment. Such patients often require repeated surgeries for retinal re-attachment; therefore, a preventive measure for PVR is of utmost importance. The contractile membranes formed in PVR, are composed of various cell types including the retinal pigment epithelial cells (RPE; fibronectin is an important constituent of the ECM surrounding these cells. Together with the vitreous, fibronectin creates microenvironments in which RPE cells proliferate. We have successfully developed a dual-action, fully human, fibronectin-specific single chain variable fragment antibody (scFv termed Fn52RGDS, which acts in two ways: i binds to cryptic sites in fibronectin, and thereby prevents its self polymerization/fibrillogenesis, and ii interacts with the cell surface receptors, ie., integrins (through an attached "RGD" sequence tag, and thereby blocks the downstream cell signaling events. We demonstrate the ability of this antibody to effectively reduce some of the hallmark features of fibrosis--migration, adhesion, fibronectin polymerization, matrix metalloprotease (MMP expression, as well as reduction of collagen gel contraction (a model of fibrotic tissue remodeling. The data suggests that the antibody can be used as a rational, novel anti-fibrotic candidate.

  16. Extracellular matrix structure.

    Science.gov (United States)

    Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

    2016-02-01

    Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented.

  17. Composição centesimal do fruto, extrato concentrado e da farinha da uva-do-japão Chemical composition of fruit, concentrated extract and flour from "Japanese grape"

    Directory of Open Access Journals (Sweden)

    Marlene Bampi

    2010-11-01

    Full Text Available A Hovenia dulcis, mais conhecida como uva-do-japão, pertence à família Rhamnaceae, é natural da China, Japão e Coréia, sendo largamente difundida no sul do Brasil. Rica em açúcares e bem aceita para consumo humano, pode ser consumida in natura ou processada. Não há na literatura relatos de seu aproveitamento em produtos alimentícios. O presente trabalho teve por objetivo determinar a composição centesimal do fruto, do extrato concentrado e da farinha. Foram obtidos teores em torno de 54,08, 52,44 e 19,08g 100g-1 para umidade; 2,16, 4,09 e 4,48g 100g-1 para cinzas; 3,74, 2,77 e 5,73g 100g-1 para proteína bruta; 1,42, 0,37 e 1,82g 100g-1 para extrato etéreo; 12,56, 3,33 e 25,62g 100g-1 para fibra alimentar; 19,46, 37,34 e 42,53g 100g-1 para açúcares totais, além do valor calórico de 105,56, 165,14 e 216,09kcal 100g-1, respectivamente, em fruto, extrato concentrado e farinha. A quantificação por cromatografia líquida confirmou o conteúdo dos açúcares redutores (frutose, 6,15g 100g-1 e glicose, 6,57g 100g-1 superior ao teor de açúcares não redutores no fruto (sacarose, 3,56g 100g-1. A farinha é rica em açúcares e possui elevado teor de fibra alimentar, podendo ser utilizada como um ingrediente alternativo em produtos de panificação. Em termos sensoriais, o extrato concentrado obteve um índice de aceitabilidade de 82% entre os julgadores, apresentando bom potencial para elaboração de geleias.Hovenia dulcis, whose popular name is Japanese grape, belongs to the family Rhamnaceae, native of China, Japan and Korea, is widely distributed in southern Brazil. Rich in sugar and with good acceptance for human consumption it can be consumed fresh or processed. There are no literature reports of its use in food products. The aim of this study was to determine the chemical composition of the Japanese grape fruit, concentrated extract and flour. The contents for moisture (54.08, 52.44 e 19.08g 100g-1, ash (2.16, 4.09 e 4.48g

  18. Efeito da concentração de coagulantes e do pH da solução na turbidez da água, em recirculação, utilizada no processamento dos frutos do cafeeiro Effects from the concentration of coagulants and pH solution on the turbidity of the recirculating water used in the coffee cherry processing

    Directory of Open Access Journals (Sweden)

    Antonio T. Matos

    2007-08-01

    Full Text Available Com o objetivo de determinar a dose e a faixa de pH dos coagulantes sulfato de alumínio (SA, sulfato ferroso clorado (SFC, cloreto férrico (CF e extrato de semente de moringa (ESM, que proporcionassem maior eficiência na remoção da turbidez na água residuária da despolpa de frutos do cafeeiro (ARDC, após serem efetuadas cinco recirculações, foram conduzidos ensaios de coagulação/floculação utilizando o aparelho "Jar-test". Todos esses coagulantes foram avaliados nas concentrações de 0; 0,5; 1,0; 1,5; 2,0; 2,5 e 3,0 g L-1. No caso da solução preparada com ESM, as doses utilizadas foram: 0; 10; 20; 30; 40; 50 e 60 mL L-1. O pH da solução em teste foi alterado, utilizando-se do hidróxido de sódio (NaOH, na concentração de 0,3 mol L-1, sendo avaliadas as faixas de 4,0 a 5,0; 5,0 a 6,0; 6,0 a 7,0 e 7,0 a 8,0. No ensaio de coagulação/floculação, o ESM proporcionou maior remoção de SS (sólidos em suspensão da ARDC com a dose de 10 mL L-1 e pH de 4,27 (natural. Para os coagulantes SA e CF, os melhores resultados foram obtidos com a concentração de 3 g L-1 e pH de 7,27 e, para o coagulante SFC, com a concentração de 3 g L-1 e pH de 4,27.Aiming the determination of the dose and pH range of the coagulants aluminum sulfate (AS, chlorinated ferrous sulfate (CFS, ferric chloride (FC and Moringa oleifera seed extract (MSE that would provide a higher efficiency in removing the turbidity from the coffee cherry pulping wastewater (CPW, five recirculations were accomplished and the coagulation/flocculation assays were conducted, by using the Jar-test device. The concentrations (0; 0.5; 1.0; 1.5; 2.0; 2.5 and 3.0 g L- 1 were evaluated. In the case of the MSE-prepared solution, the following doses were used: 0; 10; 20; 30; 40; 50 and 60 mL L-1. The pH of the solution under test was changed, by using the sodium hydroxide (NaOH at the concentration of 0.3 mol L-1, whereas the ranges from 4.0 to 5.0; 5.0 to 6.0; 6.0 to 7.0; and 7

  19. Purification and biochemical characterization of a halotolerant Staphylococcus sp. extracellular lipase.

    Science.gov (United States)

    Daoud, Lobna; Kamoun, Jannet; Ali, Madiha Bou; Jallouli, Raida; Bradai, Rim; Mechichi, Tahar; Gargouri, Youssef; Ali, Yassine Ben; Aloulou, Ahmed

    2013-06-01

    We have isolated a lipolytic halotolerant bacterium, designated as CJ3, that was identified as a Staphylococcus sp. Culture conditions were optimized and the highest extracellular lipase production amounting to 5 U/ml was achieved after 24 h of cultivation. The extracellular lipase was purified 24-fold by ammonium sulfate precipitation and a Sephacryl S-200 chromatography, and its molecular mass was found to be around 38 kDa, as revealed by SDS-PAGE and gel filtration. The lipase substrate specificity was investigated using short (tributyrin) and long (olive oil) chain triglyceride substrates. The lipase was inhibited by submicellar concentrations of Triton X-100, and maximum specific activities were found to be 802 U/mg on tributyrin and 260 U/mg on olive oil at pH 8.0 and 45 °C. The lipase was fairly stable in the pH range from 6.0 to 9.0, and about 69% of its activity was retained after incubation at 45 °C for 60 min. The enzyme showed a high tolerance to a wide range of salt concentration and a good stability in organic solvents, especially in long-chain alcohols.

  20. Seleção de leveduras da Região Amazônica para produção de protease extracelular Screening of yeasts from Amazon Region for extracellular protease production

    Directory of Open Access Journals (Sweden)

    Kilma Cristiane Silva Neves

    2006-01-01

    Full Text Available O objetivo deste trabalho foi identificar 50 leveduras isoladas a partir de diferentes substratos da Região Amazônica e selecionar uma espécie de maior atividade proteolítica. Entre as 26 espécies identificadas predominaram Candida aquatica (12% e Candida tropicalis (10%. A fermentação submersa foi realizada em Extrato de Malte suplementado com gelatina 1%, Candida intermedia foi a que expressou maior atividade proteolítica, halo = 25 mm e 273 U/mL, crescimento máximo a 30 ºC, viabilidade celular 6,2 x 10(6 UFC, em 48 horas, não demonstrou características de patogenicidade e a melhor densidade do inóculo foi 3%, utilizando-se culturas com 24 horas de crescimento em ágar Malte.The objective of this work was to identify 50 yeasts isolates obtained from differents substracts from Amazon Region and to select one species of higher proteolytic activity. Among the 26 identified species it had predominance of Candida aquatica (12% and Candida tropicalis (10%. The submerged fermentation was carried out in Malt Extract supplemented with gelatin 1%, Candida intermedia exhibited higher proteolytic activity, halo = 25 mm and 273U/mL, the maximum growth 30 ºC, the cellular viability 6.2 x 10(6 UFC, in 48 hours, did not demonstrate pathogenicity characteristics and the best inoculum density tested was 3%, using 24 hours Malt agar cultures.

  1. Analysis of neofructooligosaccharides production mediated by the extracellular β-fructofuranosidase from Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Linde, Dolores; Rodríguez-Colinas, Barbara; Estévez, Marta; Poveda, Ana; Plou, Francisco J; Fernández Lobato, María

    2012-04-01

    The extracellular β-fructofuranosidase Xd-INV from the yeast Xanthophyllomyces dendrorhous mainly synthesizes the neo-fructooligosaccharides (neo-FOS) neokestose and neonystose. This enzyme is a glycoprotein with a content of 59-67% N-linked carbohydrates and an estimated molecular mass of 160-200 kDa. The extent level of glycosylation affects the thermal behaviour of the enzyme but not its hydrolase and transferase activities, which are optimal at 60-70 °C. The neo-FOS yield of this enzyme was increased from 40 to 168 g/L when the sucrose concentration increased from 420 to 600 g/L and when the reaction was carried out at 60 °C. The neo-FOS levels obtained (168 g/L) in this work are the largest reported for any microbial β-fructofuranosidase.

  2. Importance of the evaluation of serum albumin concentration in postoperative period of patients submitted to major surgeries Importância da avaliação da concentração da albumina sérica no pós-operatório de operações de grande porte

    Directory of Open Access Journals (Sweden)

    Luiz Ronaldo Alberti

    2010-06-01

    Full Text Available BACKGROUND: The prevalence of protein-energy malnutrition in surgical patients is high, ranging from 10% to 54%. The correct assessment of the nutritional status of such patients is crucial since malnourishment is a risk factor for morbidity and mortality. AIM: To assess the effect of surgical trauma in serum albumin concentration during the immediate postoperative period of major surgeries. METHODS: The study was conducted on 100 randomly chosen adult patients submitted to elective major surgeries, classified according to sex, age and skin color. Blood samples for the determination of serum albumin concentrations were obtained on the days before and after the surgical procedure. RESULTS: There was a reduction in serum albumin from 3.72 ± 0.47 to 2.83 ± 0.71 g/dL (PRACIONAL: A prevalência de desnutrição energético-protéica em pacientes cirúrgicos é alta, variando entre 10% a 54%. A correta avaliação do estado nutricional desses pacientes é crucial uma vez que a desnutrição é um fator de risco para a morbidade e mortalidade. OBJETIVO: Avaliar o efeito do trauma cirúrgico na concentração sérica de albumina, durante o período pós-operatório imediato de operações de grande porte. MÉTODOS: O estudo foi conduzido em 100 pacientes escolhidos aleatoriamente adultos submetidos a procedimentos cirúrgicos eletivos de grande porte, classificados de acordo com sexo, idade e cor da pele. As amostras de sangue para a determinação da concentração sérica de albumina foram obtidas nos dias antes e após o procedimento cirúrgico. RESULTADOS: Houve diminuição da albumina sérica de 3,72 ± 0,47-2,83 ± 0,71 g / dL (P <0,0001, sem diferença de sexo ou cor da pele para operações de grande porte. Com relação à faixa etária, a maior queda da albumina foi observada entre os pacientes com idade superior a 65 anos, seguidos pelos pacientes mais jovens (<45 anos e, finalmente, pacientes com idade entre 45-65 anos. CONCLUSÃO: As

  3. Influência da temperatura e da concentração do cloreto de sódio (NaCl nas isotermas de sorção da carne de tambaqui (Colossoma macroparum Influence of temperature and concentration of the chloride sodium(NaCl on sorption isotherms of tambaqui meat (Colossoma macroparum

    Directory of Open Access Journals (Sweden)

    Lucídio Molina-Filho

    2006-06-01

    Full Text Available As isotermas de sorção da carne de tambaqui desidratada osmoticamente foram determinadas a três temperaturas (5, 17 e 29ºC e com duas concentrações de solução osmótica (10 e 30% de NaCl, pelo método gravimétrico. Quatro modelos de sorção foram testados para verificar o melhor ajuste; GAB, Oswin, BET e PELEG. Os dados experimentais se ajustaram satisfatoriamente aos modelos. O modelo escolhido para este trabalho foi o de PELEG. Para o ajuste nas curvas de sorção, foi feita a análise de regressão não-linear, usada o programa estatístico ORIGIN 4.0 para estimar as constantes dos modelos. A avaliação do melhor ajuste foi feita pela análise do coeficiente de determinação do ajuste (r² e teste de Qui-quadrado (x². Foram analisadas as influências da variação da temperatura e concentração de NaCl na atividade de água da carne do tambaqui. À medida que decresce a temperatura há um decréscimo na atividade de água. Um aumento na concentração do NaCl diminui a atividade de água. A propriedade termodinâmica estudada foi o calor isostérico de sorção. A medida que aumenta a concentração da solução osmótica aumenta o valor do calor isostérico de sorção.Sorption isotherms were determined for tambaqui fish osmotic treated at three different temperatures (5, 17 e 29ºC and for two concentration (10 e 30% of NaCl, using a standard gravimetric method. Four mathematics models were tested to verify the best fit of the experimental data: GAB, Oswin, BET e PELEG. The experimental data fitted goodness to all models. The chosen model was PELEG. The adjustment on sorption isotherms curves was done by a non-linear regression, using statistical program ORINGIN 4.0 to esteem the constants of the models sorption isotherms. The evaluation of goodness fit was shown through the analysis of the coefficient of determination (r² and Qui-square (x². The influences of the temperature of the meat of the tambaqui had been analysed

  4. Identification of enzymes responsible for extracellular alginate depolymerization and alginate metabolism in Vibrio algivorus.

    Science.gov (United States)

    Doi, Hidetaka; Tokura, Yuriko; Mori, Yukiko; Mori, Kenichi; Asakura, Yoko; Usuda, Yoshihiro; Fukuda, Hiroo; Chinen, Akito

    2017-02-01

    Alginate is a marine non-food-competing polysaccharide that has potential applications in biorefinery. Owing to its large size (molecular weight >300,000 Da), alginate cannot pass through the bacterial cell membrane. Therefore, bacteria that utilize alginate are presumed to have an enzyme that degrades extracellular alginate. Recently, Vibrio algivorus sp. SA2(T) was identified as a novel alginate-decomposing and alginate-utilizing species. However, little is known about the mechanism of alginate degradation and metabolism in this species. To address this issue, we screened the V. algivorus genomic DNA library for genes encoding polysaccharide-decomposing enzymes using a novel double-layer plate screening method and identified alyB as a candidate. Most identified alginate-decomposing enzymes (i.e., alginate lyases) must be concentrated and purified before extracellular alginate depolymerization. AlyB of V. algivorus heterologously expressed in Escherichia coli depolymerized extracellular alginate without requiring concentration or purification. We found seven homologues in the V. algivorus genome (alyB, alyD, oalA, oalB, oalC, dehR, and toaA) that are thought to encode enzymes responsible for alginate transport and metabolism. Introducing these genes into E. coli enabled the cells to assimilate soluble alginate depolymerized by V. algivorus AlyB as the sole carbon source. The alginate was bioconverted into L-lysine (43.3 mg/l) in E. coli strain AJIK01. These findings demonstrate a simple and novel screening method for identifying polysaccharide-degrading enzymes in bacteria and provide a simple alginate biocatalyst and fermentation system with potential applications in industrial biorefinery.

  5. Colicin S8 export: extracellular and cytoplasmic colicin are different.

    Science.gov (United States)

    Garcia Diaz, Maria-Elena; Concepción Curbelo, Juan Luis

    2003-12-01

    The properties of colicin S8 are different for the cytoplasmic, periplasmic and extracellular protein. Interactions with its specific receptors reflect this. Active cell extracts separate into a non-anionic along with an anionic fraction by DEAE-Sephacell chromatography. Previously, we have purified cell-associated colicin S8 as an aggregation of highly related polypeptides; cytoplasmic colicin S8 seems to be post-translationally processed into an aggregation of polypeptides of molecular mass ranging from 45,000 Da to 60,000 Da. We suggest that a conformational change to colicin S8 may occur related to the export process.

  6. Concentrados protéicos para bovinos: 1. Digestibilidade in situ da matéria seca e da proteína bruta Protein concentrates for bovines: 1. In situ digestibility of dry matter and crude protein

    Directory of Open Access Journals (Sweden)

    J.F.C. Moreira

    2003-06-01

    Full Text Available O objetivo deste trabalho foi determinar a degradação ruminal, pela técnica in situ, da matéria seca (MS e da proteína bruta (PB de 10 concentrados protéicos. As degradações potenciais da MS e da PB das farinhas de origem vegetal, soja, algodão, mamona e palmiste, mostraram-se elevadas (próximas a 100%, porém em função de taxas de degradação mais altas para o farelo de soja (10% e menores para o algodão (4%, mamona (MS:3%; PB:1,2% e palmiste (1,7%, as degradabilidades efetivas (DE foram bem superiores para o farelo de soja, independentemente da taxa de passagem, o que a torna a fonte protéica de maior disponibilidade ruminal. O glúten de milho mostrou ser uma fonte protéica de baixa degradabilidade ruminal (DE da PB: 16% para 0,05 de taxa de passagem. Dentre os alimentos de origem animal, a maior degradabilidade potencial da proteína bruta foi verificada para a farinha de carne e ossos ( 75,5%, seguida das farinhas de peixe I (58,5%, de penas e vísceras (52,3% e de sangue (36,7%. A maior degradabilidade efetiva para a taxa de passagem de 5% foi a da farinha de carne e ossos (51%, seguida da farinha de peixe I (41%, de penas e vísceras (40,0% e de sangue (33%. A farinha de peixe II apresentou valores muito baixos de degradabilidade, apenas 22% com 48h de incubação ruminal.This work aimed to determine the in situ rumen digestibility of dry matter (DM and crude protein (CP using 10 protein sources. Potential degradabilities of DM and CP of soybean meal, cottonseed meal, castorbean meal and palmist coconut meal were high (around 100%, however due to higher fractional degradation rates of soybean meal (10% and lower for cottonseed meal (4%, castorbean meal (DM:3%, CP:1.2% and palmist meal (1.7%, the effective degradability (ED of soybean was significantly higher despite the rates of passage, showing this protein source has the highest ruminal nitrogen availability (from 86% to 63%, as rate of passage increased from 2 to 8

  7. Efeito da carga de frutos e concentrações salinas no crescimento do meloeiro Cultivado em substrato Effect of fruit load and saline concentrations on the growth of melon cultivated under protected environment

    Directory of Open Access Journals (Sweden)

    Tatiana da S Duarte

    2008-09-01

    Full Text Available O objetivo foi avaliar o efeito do número de frutos por planta e de concentrações salinas em solução nutritiva recirculante, no crescimento do meloeiro cultivado em ambiente protegido e em substrato de casca de arroz crua, durante os meses de fevereiro a maio de 2003. Três números de frutos por planta (2, 3 e 4 e três concentrações salinas da solução nutritiva (1,9; 2,3 e 2,9 dS m-1 foram estudados. A partir dos dados da matéria seca (MS e fresca (MF e da área foliar, acumuladas aos 62 dias após o transplante, foi determinada a produção e a distribuição de biomassa entre as diferentes partes da planta. Os frutos compreenderam de 49 a 55% da MS aérea total produzida pela planta, demonstrando que estes são os órgãos drenos de assimilados mais potentes. O aumento do número de frutos reduziu o peso médio dos frutos, sem afetar a produção e a distribuição de MS total, vegetativa e generativa. Entretanto, aumentou levemente a produção de MF dos frutos e da parte aérea como um todo, favorecendo a distribuição de MF para os frutos. Portanto, o acúmulo de água nos frutos ocorreu em uma proporção diferente do acúmulo da MS. A menor concentração salina da solução nutritiva testada pode ser indicada para o cultivo do meloeiro em substrato de casca de arroz crua durante o outono, pois promove um crescimento da planta similar ao observado nas concentrações mais altas.The effect of fruit load and of saline concentrations in nutrient solution recirculating, was evaluated on the growth of melon plants cultivated under protected cultivation and in raw rice husk, during the months February to May of 2003. Three numbers of fruits/plant (2, 3 and 4 and three saline concentrations of the nutrient solution (1,9; 2,3 and 2,9 dS m-1 were studied. From the data of dry and fresh matter (DM and FM, and of the leaf area accumulated at 62 days after setting, the biomass production and distribution among the different plant parts

  8. Extracellular Vesicle (EV) Array

    DEFF Research Database (Denmark)

    Jørgensen, Malene; Bæk, Rikke; Pedersen, Shona

    2013-01-01

    their phenotype and determine their concentration in biological fluids. To identify circulating as well as cell culture-derived vesicles, the current standard is immunoblotting or a flow cytometrical analysis for specific proteins, both of which requires large amounts of purified vesicles....

  9. Extracellular vesicles for drug delivery

    NARCIS (Netherlands)

    Vader, Pieter; Mol, Emma A; Pasterkamp, Gerard; Schiffelers, Raymond M

    Extracellular vesicles (EVs) are cell-derived membrane vesicles, and represent an endogenous mechanism for intercellular communication. Since the discovery that EVs are capable of functionally transferring biological information, the potential use of EVs as drug delivery vehicles has gained

  10. Extracellular calmodulin: A polypeptide signal in plants?

    Institute of Scientific and Technical Information of China (English)

    SUN; Daye(

    2001-01-01

    Regulation, 1998, 25: 23-28.[34]Cui. S. J.. Wang, H. H., Ma, L. G. et al., The effects of extracellular calmodulin of style and pollen on pollen germination and pollen tube growth, Acta Phytophysiologica Sinica (in Chinese), 1998, 42: 320-326.[35]Ma, L. G.. Xu, X. D., Cui, S. J. et al., Effects of extracellular calmodulin on pollen germination and tube growth, Chin. Sci.Bull. (in Chinese), 1998, 43(2): 143-146.[36]Wanner. L. A., Gruissem, W., Expression dynamics of the tomato rbcS gene family during development, Plant Cell, 1991,3: 1289-1303.[37]Sawbridge, T. I., Knight, M. R., Jenkins, G. I., Ontogenetic regulation and photoregulation of members of the Phaseolus vulgaris L. rbcS gene family, Planta, 1996, 198: 31-38.[38]Zhang, S. Q., Ma, L. G., Sun, D. Y., The effect of extracellular calmodulin on rbcS-3A expression in suspension-cultured tomato cells, Acta Botanica Sinica (in Chinese), 2000, 42(6): 653-655.[39]Shang, Z. L., Ma, L. G., Wang, X. C. et al., Effect of extracellular calmodulin on the cytosolic Ca2+ concentration in lily pollen grains, Acta Botanica Sinica (in Chinese), 2001, 43(1): 12-17.[40]Ma, L. G., Xu, X. D., Cui, S. J. et al., The presence of a heterotrimeric G protein and its role in signal transduction of extracellular calmodulin in pollen germination and tube growth, Plant Cell, 1999, 11: 1351-1363.[41]Guo, Y., Ma, L. G., Zhang, L. et al., The involvement of hetrotrimeric G protein in signal transduction of extracellular calmodulin in regulating rbcS expression, Chin. Sci. Bull., 2000, 45(20): 2195-2200.[42]Ma, L. G., Xu, X. D., Cui, S. J. et al., The involvement of phosphoinositide signaling pathway in the initiatory effects of extracellular calmodulin on pollen germination and tube growth, Acta Phytophysiologica Sinica (in Chinese), 1998, 24:196-200.[43]Wang, X., Cui, S. J., Ma, L. G. et al., The involvement of PLC-IP3 pathway in pollen tube growth by microinjection study,Acta Botanica Sinica (in Chinese), 2000

  11. Seasonal variation of nutrients leaves concentration of banana plants in Vale do Ribeira-SPVariação sazonal da concentração de nutrientes em folhas de bananeiras, no Vale do Ribeira-SP

    Directory of Open Access Journals (Sweden)

    José Carlos de Mendonça

    2012-08-01

    Full Text Available The Vale do Ribeira, SP, main agricultural activity is the banana crop, which accounts for most of this fruit production in the State of São Paulo. The nutritional balance of the plant is one of the most important factors for the banana plant can complete the cycle and achieve high productivity. Aiming to evaluate the seasonal variation of leaf nutrient concentration in banana plants in Vale do Ribeira-SP, we used the results of 252 chemical analyses of plant tissue, collected from August 2009 to September 2010, in the 18 representative properties for the region, ten cultivated with subgroup Cavendish banana plant and eight of subgroup Prata banana plant. The largest variation between the macronutrient occurred for K and S, and among the micronutrients, especially for Fe and B. In some dates of evaluation, there was a higher leaf concentration of P, K, Ca and Zn, in subgroup Cavendish banana plants, while the subgroup Prata banana plants showed higher leaf concentration, especially of Mn, B and N. Climatic conditions, especially rain, influenced the leaf nutrient content, especially for K, N, S, B and Fe. O Vale do Ribeira, SP, tem como principal atividade agropecuária o cultivo da bananeira, sendo responsável pela maior parte da produção dessa frutífera no estado de São Paulo. O equilíbrio nutricional da planta é um dos fatores mais importantes para que esta consiga completar o ciclo e alcançar alta produtividade. Com o objetivo de avaliar a variação sazonal da concentração foliar de nutrientes em bananeiras cultivadas no Vale do Ribeira-SP, foram utilizados 252 resultados de análise química de nutrientes do tecido vegetal, coletados no período de agosto de 2009 a setembro de 2010, de 18 propriedades representativas na região, dez cultivadas com bananeira do subgrupo Cavendish e oito do subgrupo Prata. A maior variação entre os macronutrientes ocorreu para o K e o S e entre os micronutrientes, principalmente, para o Fe e o B

  12. In vitro solubility of meat and bone meal protein with different pepsin concentrations Solubilidade in vitro da proteína de farinhas de carne e ossos com diferentes concentraçoes de pepsina

    Directory of Open Access Journals (Sweden)

    Cláudio Bellaver

    2000-06-01

    Full Text Available In vitro protein digestibility of protein sources has been correlated with in vivo digestibility values. However, factors like protein origin, enzyme used and its concentration, pH and processing have been related with the significance of the correlation between the estimates. To address only the enzyme concentration factor, this paper had the objective of testing pepsin at 0.2, 0.02, 0.002 and 0.0002% using the standard AOAC (1995 procedure. Two meat and bone meals (MBM with low and high crude protein (CP content were used to determine the coefficient of solubility of CP in pepsin and HCl (CSCPPEPH. Centrifugation was used to establish the nitrogen (N in the soluble phase, instead of filtration and analysis of N in the residue. The variance analysis and a non-linear asymptotic model were adjusted. The CSCPPEPH under different pepsin concentrations for the two MBM showed higher solubility discrimination with low pepsin concentration. The level of 0.0002% pepsin is better to predict the CP soluble in MBM. This finding implies the assumption that 0.2% pepsin found in the AOAC is not correct for the purpose of determining the range of solubility in high and low CP content in MBM.A digestibilidade in vitro da proteína de fontes protéicas tem sido correlacionada com a digestibilidade in vivo. Entretanto, fatores como a origem protéica, enzima usada e sua concentração, pH e processamento têm sido relacionados com a significância da correlação entre as estimativas. Para atuar somente no fator da concentração enzimática, este trabalho teve por objetivo testar a pepsina nas concentrações de 0,2, 0,02, 0,002 e 0,0002%, utilizando o procedimento padrão do AOAC (1995. Duas farinhas de carne e ossos com baixo ou alto teor de proteína (PB foram usadas para determinar o coeficiente de solubilidade da PB em pepsina e HCl (CSCPPEPH. Centrifugação foi usada para obter o nitrogênio (N na fase solúvel, em vez da filtração e análise do N no

  13. Effects and mechanisms of chronic morphine exposure on extracellular glutamate concentration in C6 cells%吗啡慢性暴露对C6细胞胞外谷氨酸浓度的影响及其机制

    Institute of Scientific and Technical Information of China (English)

    傅艳妮; 郭明炎; 刘玲; 纪风涛; 刘安民; 曹铭辉

    2015-01-01

    目的 探讨慢性吗啡暴露对C6胶质瘤细胞胞外谷氨酸浓度的影响及其机制.方法 培养好的C6细胞随机分为4组:对照组(细胞培养液培养,不加任何药物)、10 Mor组(10 μmol/L吗啡处理48 h)、撤药组(10 μmol/L吗啡预处理48 h后停药12 h)、5 Mor组(10 μmol/L吗啡预处理48 h、停药12h后再以5μmol/L吗啡复处理4h).采用磺酰罗丹明B(SRB)法检测细胞存活率,高效液相色谱测定细胞外液谷氨酸(Glu)水平,Western blot法检测细胞兴奋性氨基酸转运蛋白3(EAAT3)蛋白表达,实时定量反转录聚合酶链反应(RT-qPCR)检测EAAT3 mRNA表达水平.结果 (1)对照组细胞外液谷氨酸浓度为(18.03 ±1.11) mg/L.10 μmol/L吗啡作用C6细胞48 h后细胞外液Glu浓度上升至(41.76 ±7.14) mg/L,与对照组比较明显增加(P<0.05).撤药12 h后Glu浓度降至(25.22±2.26) mg/L,后再以5μmol/L吗啡处理4h后,细胞外液Glu浓度再次升至(40.18±7.08) mg/L,较对照组与撤药12h均明显增加(P<0.05).(2)C6细胞经吗啡作用48 h后EAAT3蛋白表达较对照组明显减少(P<0.05),撤药12h后EAAT3蛋白表达水平与对照组差异无统计学意义(P>0.05);5μmol/L吗啡再次处理4h,EAAT3蛋白表达再次明显升高(P<0.05).(3)4组中EAAT3 mRNA表达水平差异均无统计学意义(P>0.05).结论 吗啡慢性暴露引起C6细胞胞外Glu浓度增加,与EAAT3蛋白表达下降有关,EAAT3表达下调可能为转录后水平调节.%Objective To explore the effects and mechanisms of chronic morphine exposure on extracellular glutamate (Glu) concentration in C6 cells.Methods Well-grown C6 cells were divided into 4 groups: control group (C6 cells were treated with no drugs), 10 Mor group (10 μmol/L morphine treatment for 48 h), withdrawal group (after 10 μmol/L morphine treatment for 48 h, C6 cells were cultured in medium without morphine for 12 h, a simulation of the abstinence process), 5 Mor group (after C6 cells experienced morphine exposure

  14. The effect of irradiation and thermal process on beef heme iron concentration and color properties Efeito da irradiação e processo térmico na concentração do ferro heme e nas propriedades de cor da carne

    Directory of Open Access Journals (Sweden)

    Liliana Perazzini Furtado Mistura

    2009-03-01

    Full Text Available The aim of this study was to evaluate the influence of irradiation and thermal process on the heme iron (heme-Fe concentration and color properties of Brazilian cattle beef. Beef samples (patties and steaks were irradiated at 0-10 kGy and cooked in a combination oven at 250 ºC for 9 minutes with 70% humidity. Total iron and heme iron (heme-Fe concentrations were determined. The data were compared by multiple comparisons and fixed- effects ANOVA. Irradiation at doses higher than 5 kGy significantly altered the heme-Fe concentration. However, the sample preparation conditions interfered more in the heme-Fe content than did the irradiation. Depending on the animal species, meat heme iron levels between 35 and 52% of the total iron are used for dietetic calculations. In this study the percentage of heme-iron was, on average, 70% of the total iron showing that humidity is an important factor for its preservation. The samples were analyzed instrumentally for CIE L*, a*, and b* values.O objetivo deste estudo foi avaliar a influência da irradiação e de processos térmicos na concentração do ferro heme (Fe heme e nas propriedades de cor da carne do gado brasileiro. As amostras da carne (hambúrgueres e bifes foram irradiadas com 0-10 kGy e foram cozidas em um forno combinado a 250 ºC por 9 minutes com umidade de 70%. As concentrações de ferro total e de ferro heme foram determinadas. Os dados foram comparados por comparações múltiplas e por efeitos fixos, ANOVA. Irradiação em doses mais altas do que 5 kGy alteraram significativamente a concentração de Fe heme. Entretanto, as condições de preparo da amostra, interferiram muito mais na quantidade de Fe heme do que a irradiação. Dependendo da espécie animal, os níveis do ferro heme da carne estão entre 35 e 52% do ferro total e são usados para cálculos dietéticos. Em nosso estudo, a porcentagem de ferro heme foi em média, 70% do ferro total, mostrando que a umidade é um fator

  15. Um dispositivo simples para a determinação simultânea e contínua da densidade de líquidos e da concentração de suspensões líquidas A simple device for on-line determinations of liquid density and suspension concentration

    Directory of Open Access Journals (Sweden)

    Sabrina S. Paes

    2004-06-01

    Full Text Available Um dispositivo para a determinação automática da densidade e da concentração de partículas em suspensões líquidas foi desenvolvido, usando suspensões de amido de mandioca como modelo. As determinações das propriedades foram baseadas na medição da força de empuxo que a suspensão líquida exerce sobre uma bóia de plástico esférica, submersa na mesma e conectada a um sistema eletrônico de medição de força. Os resultados obtidos mostraram que o dispositivo é um excelente densímetro e pode ser usado com sucesso para a determinação da concentração de suspensões líquidas de partículas, quando a relação entre concentração de sólidos e a densidade da suspensão é conhecida. Resultados da medida de densidade de líquidos com o dispositivo, como o glicerol com 99% de pureza e um óleo de soja comercial ficaram muito próximos dos valores citados na literatura e medidos por picnometria.A simple device was developed to determinate simultaneously the density and the concentration of particle suspensions. Cassava starch suspensions were used as a model to carry out the experiments and to develop the equipment. The determinations were based on the measure of the force suffered by a spherical plastic buoy immersed in the suspension under study. This force was transmitted to a force measure electronic cell by means of a metal stem. The experimental results showed that the device developed is a very good densimeter, which can be used to determine suspension concentration with good accuracy, when the relation between density and suspension concentration is known. Results of glycerin and a commercial soy oil density measures were in good agreement with the ones obtained in the literature and by picnometry technique, respectively.

  16. Extracellular potassium homeostasis: insights from hypokalemic periodic paralysis.

    Science.gov (United States)

    Cheng, Chih-Jen; Kuo, Elizabeth; Huang, Chou-Long

    2013-05-01

    Extracellular potassium makes up only about 2% of the total body's potassium store. The majority of the body potassium is distributed in the intracellular space, of which about 80% is in skeletal muscle. Movement of potassium in and out of skeletal muscle thus plays a pivotal role in extracellular potassium homeostasis. The exchange of potassium between the extracellular space and skeletal muscle is mediated by specific membrane transporters. These include potassium uptake by Na(+), K(+)-adenosine triphosphatase and release by inward-rectifier K(+) channels. These processes are regulated by circulating hormones, peptides, ions, and by physical activity of muscle as well as dietary potassium intake. Pharmaceutical agents, poisons, and disease conditions also affect the exchange and alter extracellular potassium concentration. Here, we review extracellular potassium homeostasis, focusing on factors and conditions that influence the balance of potassium movement in skeletal muscle. Recent findings that mutations of a skeletal muscle-specific inward-rectifier K(+) channel cause hypokalemic periodic paralysis provide interesting insights into the role of skeletal muscle in extracellular potassium homeostasis. These recent findings are reviewed. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Concentration of nutrient solution in the hydroponic production of potato minitubers Concentração da solução nutritiva na produção hidropônica de minitubérculos de batata

    Directory of Open Access Journals (Sweden)

    Manuel Benito Novella

    2008-09-01

    Full Text Available The effect of the nutrient solution concentration on potato plant growth and minituber yield were determined in a sand closed hydroponic system. Minitubers and micropropagated plantlets of the cv. 'Macaca' were used. Treatments were five nutrient solution concentrations at electrical conductivities (EC of 1.0 (T1, 2.2 (T2, 3.4 (T3, 4.7 (T4 and 5.8dS m-1 (T5. The split plot randomised experimental design was used with three replications. Plants from minitubers produced higher fresh and mean weight of minitubers, shoot dry mass and leaf area index than the micropropagated ones. However, higher dry mass of minitubers was found with micropropagated plantlets compared to minitubers. The concentration of the nutrient solution did not affect minituber number. Increasing the nutrient solution concentration decreased total and minituber dry mass production of micropropagated plantlets and plant growth and minituber production of minituber-originated plants. Low concentration of nutrient solution at an EC of about 1.0dS m-1 can be used in the hydroponic production of potato minitubers of both micropropagated and minituber-originated plants.Neste trabalho foi determinado o efeito da concentração da solução nutritiva no crescimento e na produtividade de minitubérculos de batata em um sistema hidropônico fechado empregando areia como substrato. Plântulas micropropagadas e minitubérculos foram plantados em 24 de março de 2004. Os tratamentos foram cinco soluções nutritivas com condutividades elétricas (CE de 1,0 (T1, 2,2 (T2, 3,4 (T3, 4,7 (T4 e 5,8dS m-1 (T5. O experimento foi conduzido em parcelas subdivididas no delineamento inteiramente casualizado com três repetições. Plantas originadas de minitubérculos produziram mais massa fresca total e média de minitubérculos, massa seca da parte aérea e maior índice de área foliar que plantas micropropagadas. Entretanto, maior massa seca dos minitubérculos foi obtida em plantas micropropagadas

  18. Experimental poisoning by Senecio brasiliensis in calves: quantitative and semi-quantitative study on changes in the hepatic extracellular matrix and sinusoidal cells Intoxicação experimental por Senecio brasiliensis em bovinos: estudo quantitativo e semi-quantitativo da matrix extracelular e de células sinusoidais do fígado

    Directory of Open Access Journals (Sweden)

    Márcia Bersane A.M. Torres

    2008-01-01

    Full Text Available Extracellular matrix plays an important role in chronic hepatic lesions and has been studied in experimental intoxication models. However in cattle, studies on chronic disease have focused on the hepatocellular damage and extracellular matrix (ECM changes are usually overlooked. There are no specific studies on the hepatic ECM in either normal or chronically damaged bovine liver. Thus an experimental model of hepatic toxicity model using Senecio brasiliensis poisoned calves was designed. Senecio brasiliensis contains pyrrolizidine alkaloids which cause either acute or chronic progressive dose dependent liver damage. Five calves were orally fed with 0.38g of dry leaves of S. brasiliensis/kg/day for 24 days. Liver needle biopsy specimens were obtained every 15 days for 60 days. Clinical signs of digestive complications appeared at 3rd week. One calf died on 45th day and four were evaluated up to 60th day. Biopsy samples were processed for routine light microscopy, immuno-histochemistry and transmission electron microscopy. From 30th day on progressive liver damage characterized by hepatocellular ballooning, necrosis, apoptosis and megalocytosis, centrilobular, pericellular and portal fibrosis were seen by light microscopy. Quantitative and semi-quantitative measurements of hepatic ECM components were performed before and after the onset of lesions. Morphometric analysis of total collagen and elastic fiber system was conducted. Total collagen and I and III collagen types progressively increased in throughout the liver of affected calves. Changes in location, amount and disposition of the elastic fiber system were also observed. Then numbers of Kupffer cells were significantly increased at 30th day and total numbers of sinusoidal cells were significantly increased at 45th and 60th days. Liver damage was progressive and irreversible even after the exposure to the plant was discontinued. Severe fibrotic lesions occurred mainly in portal tracts

  19. The effects of LPM570065, a novel triple reuptake inhibitor, on extracellular serotonin, dopamine and norepinephrine levels in rats.

    Directory of Open Access Journals (Sweden)

    Renyu Zhang

    Full Text Available Triple reuptake inhibitors (TRIs are currently being developed as a new class of promising antidepressants that block serotonin (5-HT, dopamine (DA and norepinephrine (NE transporters, thereby increasing extracellular monoamine concentrations. The purpose of this study was to investigate the effects of LPM570065, a novel TRI and a desvenlafaxine prodrug, on extracellular 5-HT, DA and NE levels in the rat striatum after acute and chronic administration relative to desvenlafaxine, using High Performance Liquid Chromatography (HPLC and microdialysis. Acute administration was performed by providing rodents with oral solutions (0.06 mmol·kg(-1 p.o., oral suspensions (0.06 mmol·kg(-1 p.o. and intravenous solutions (0.04 mmol·kg(-1 i.v. of LPM570065 and desvenlafaxine. Oral suspensions (0.06 mmol·kg(-1·day(-1 of the two drugs were also administered for a 14-day chronic period. HPLC analysis revealed that LPM570065 rapidly penetrated the rat striatum, converted into desvenlafaxine and exhibited larger total exposure compared with the administration of desvenlafaxine. Microdialysis revealed that acute and chronic administration of oral suspension of LPM570065 increased the 5-HT, DA and NE levels more than the relative administration of desvenlafaxine. Unlike desvenlafaxine, acute administration of an intravenous LPM570065 solution did not induce the undesirable 90% decrease in extracellular 5-HT levels. In contrast to the fully dose-dependent elevation of 5-HT induced by desvenlafaxine, the acute administration of LPM570065 showed a capped increase in extracellular 5-HT levels when combined with WAY-100635. Additionally, forced swim test demonstrated that acute and chronic administration of LPM570065 reduced the immobility time more than the relative administration of desvenlafaxine. These data suggest that LPM570065 may have greater efficacy and/or a more rapid onset of antidepressant action than desvenlafaxine and also counterbalance the harmful

  20. 多药转运蛋白对匹罗卡品癫(癎)大鼠模型脑内拉莫三嗪浓度的影响%Impact of multi-drug transporters on regulation of concentration of lamotrigine in hippocampal extracellular fluid in rat after pilocarpine-induced seizures

    Institute of Scientific and Technical Information of China (English)

    马爱梅; 张守文; 刘玉玺; 胡风云

    2009-01-01

    Objective To investigate the impact of multi-drug transporters including P-glycoprotein (PGP) and multi-drug resistance associated protein (MRP) on concentration of lamotrigine in the extracellular fluid in hippocampus of epilepsy rat models induced by pilocarpine, and to deduce the multi-drug resistance mechanisms in refractory epilepsy. Methods The epilepsy rat models were established by repeated administration (by ip) of pilocarpine. A microdialysis probe was placed into the hippocampus of the epileptic rats and dialysate was collected at five time-points from 30--150 minutes after systemic injections of lamotrigine (10 mg/kg). The concentration of lamotrigine in the extracellular fluid in the hippocampus was determined by high-performance liquid chromatography (HPLC). Then PGP inhibitor verapamil and MRP inhibitor probenecid was added individually through microdialysis probe and the concentration of lamotrigine was detected again. Results Compared with control group (0. 41 ± 0. 10 in 60 minutes, 0. 50 ±0.04 in 90 minutes, 0. 39 ±0. 09 in 120 minutes and 0. 30±0.06 in 150 minutes), verapamil significantly increased the concentration of lamotrigine in extracellular fluid of the hippocampus 60--150 minutes (0. 65 ±0. 11, 0. 84 ± 0. 09, 0. 70± 0. 09 and 0. 58 ± 0. 08 respectively) after injection (F value were 5.01, 8.61, 10. 23 and 7.89, all P < 0. 05) and probenecid also enhanced the concentration of lamotrigine 90--150 minutes (0. 75 ± 0. 09, 0. 58±0. 10 and 0. 49±0. 07) after injection (F = 6. 58, 4. 56, 4. 75, all P < 0. 05). Conclusions Penetration of lamotrigine through blood-brain barrier in pilocarpine induced epilepsy rats is restricted by PGP and MRP, resulting in decreased concentration of lamotrigine in the extracellular fluid of the hippocampus. Therefore, increasing expression of PGP and MRP in brains of epilepsy patients might be an important mechanism involved in multi-drug resistance in refractory epilepsy.%目的 观察多药转运蛋

  1. Nutrient concentrations in potato stem, petiole and leaflet in response to potassium fertilizer Teores de nutrientes no caule, pecíolo e limbo da batateira em função da adubação potássica

    Directory of Open Access Journals (Sweden)

    Roberto dos Anjos Reis Jr.

    2000-06-01

    Full Text Available Chemical composition of potato stem, petiole and leaflet were evaluated in response to the application of K fertilizer. Potassium was applied at six different rates (0, 60, 120, 240, 480 and 960 kg ha-1 of K2O, as K2SO4 and was placed in the furrow during planting. Two plants per plot were sampled 48 days after plant emergence to evaluate N, P, K, Ca, Mg, S, Cu, Mn and Zn concentrations in stems, petioles and leaflets of the youngest fully expanded leaf. It is recommended using potato petioles to evaluate the N, P, K, Ca, Mg and Cu status and using potato leaflet to evaluate the S, Mn and Zn status. The stem was not a good indicator of S nutritional status. Petiole N, P and Cu concentrations associated with the maximum tuber yield (30.5 t ha-1, with 353.4 kg ha-1 of K2O were 25.9 g kg-1, 1.4 g kg-1 and 9.7 mg kg-1, respectively, while, the leaflet S, Mn and Zn concentrations associated with the maximum tuber yield were 4.0 g kg-1, 155.2 mg kg-1 and 59.4 mg kg-1, respectively. This information should be used to build data banks of adequate nutrient concentration at different portions of potato plant and like this, to aid the nutrient diagnosis in potato crops.Para avaliar a composição mineral em órgãos da batateira em função da adubação potássica, foi realizado experimento com doses de potássio (0, 60, 120, 240, 480 e 960 kg ha-1 de K2O delineado em blocos casualizados com quatro repetições. Duas plantas por parcela foram amostradas aos 48 dias após emergência das plantas para avaliar teores de N, P, K, Ca, Mg, S, Cu, Mn e Zn no caule, pecíolo e limbo da folha recém madura. Recomenda-se utilizar o pecíolo da batateira para avaliar o status de N, P, K, Ca, Mg e Cu e utilizar o limbo da batateira para avaliar o status de S, Mn e Zn. O caule não foi um bom indicador do estado nutricional em relação ao S. A aplicação de 353,4 kg ha-1 de K2O proporcionou a máxima produtividade de tubérculos (30,5 t ha-1 e teores de N, P e Cu no

  2. Determinação da solubilidade protéica de farinhas de subproduto de aves com a pepsina em baixa concentração Determination of solubility of poultry by-product with pepsin in low concentration

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    Claudio Bellaver

    2004-10-01

    Full Text Available Foi proposto recentemente que a solubilidade protéica in vitro com pepsina na concentração de 0,0002% é melhor que em concentrações maiores, para melhor classificar a qualidade protéica de farinhas de origem animal (FOA. Entretanto, nessa concentração, desconhece-se qual é o intervalo que melhor exprime a qualidade por meio da solubilidade protéica das FOA. Este trabalho foi conduzido com o objetivo de identificar os valores da solubilidade protéica de farinhas de subprodutos do abate de aves (FSA, utilizadas como modelo experimental. As fontes protéicas foram duas FSA e caseína (considerada padrão com 100% de solubilidade protéica. Todas as farinhas foram autoclavadas a 120ºC, durante 0, 10, 20, 40 e 80 minutos. As concentrações utilizadas da pepsina em solução de HCl 0,0744N foram de 0,0002 e 0,02%. O delineamento experimental foi o de blocos casualizados em esquema fatorial 3 (fontes x 5 (temperaturas x 2 (concentrações, com quatro repetições para a enzima na concentração de 0,0002% e duas repetições para a concentração de 0,02%. Foram determinados os valores de solubilidade protéica in vitro em solução ácido/pepsina e energia metabolizável in vivo das FSA. Os resultados indicaram que, na concentração de pepsina de 0,0002%, os valores de boa qualidade das FSA estão acima de 55%. Da mesma forma, solubilidades próximas a 84% podem ser consideradas boas, mas decaem em solubilidade e são consideradas ruins se tiverem em torno de 67% de solubilidade protéica em pepsina a 0,02%.It was recently proposed that the in vitro protein solubility is better to classify animal by-product meals (ABP using pepsin concentration of .0002% than with higher concentrations. However on this concentration no reference value exists to express ABP quality based on protein solubility. The objective of this study was to obtain protein solubility values for poultry by-product meals (PBP, as model to ABP. Two PBP and casein

  3. Certification for copper concentration in reference material for fuel anhydro ethylic alcohol; Certificacao da concentracao de cobre em material de referencia para alcool etilico anidro combustivel (AEC)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Lindomar Augusto dos; Rocha, Marcia Silva da; Mesko, Marcia Foster; Silva, Fagner Francisco da; Quaresma, Maria Cristina Baptista; Araujo, Thiago Oliveira [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (DIMCI/INMETRO), Duque de Caxias, RJ (Brazil). Diretoria de Metrologia Cientifica e Industrial], E-mail: lareis@inmetro.gov.br

    2009-07-01

    This work aiming to obtain the first certified reference material for fuel anhydro ethylic alcohol relative to the copper concentration, which has his maximum limit determined by the in force legislation providing traceability and reliability for the measurement results.

  4. Concentração sérica das enzimas creatinoquinase, aspartato aminotransferase e dehidrogenase lática em equinos da raça crioula CK, ASTand LDH seric concentration in crioulo breed horses

    Directory of Open Access Journals (Sweden)

    Elisiane Lourdes Da Cás

    2000-08-01

    Full Text Available A concentração de creatinoquinase (CK, aspartato aminotransferase (AST e dehidrogenase lática (LDH foi determinada em amostras de soro obtidas de 60 equinos da raça Crioula: 20 éguas mantidas no pasto (Grupo A, 20 equinos em treinamento (Grupo B e 20 participantes da competição do "Freio de Ouro de 1997" em Esteio - RS (Grupo C, dos quais foram colhidas amostras 24 a 48 horas antes do início da competição e 24 e 48 horas após a mesma. Não houve variação significativa na LDH. O grupo B apresentou concentrações de CK e AST mais elevadas (pCreatine Kinase (CK, Aspartate Aminotransferase (AST and Lactic Dehidrogenase (LDH concentration was determined in serum samples obtained from 60 horses of the Criollo breed: 20 mares managed on pasture (Group A, 20 horses in training (Group B and 20 horses participating of the Freio de Ouro 1997 competition (Group C, where samples were collected 24-48 hours before competition and 24 and 48 hours there after. There was no difference in LDH values between groups. Group B horses had higher (p<0.05 CK and AST serum concentrations than horses in groups A and C, indicating an adaptation to exercise. Forty eight hours after competition, CK values were lowest and AST highest. CK and AST were more informative than LDH in evaluating muscular function. Females had higher CK activity (p<0.05 than males. There were significam diferences related to final outcome of competition with a trena of lower values in the first places, indicating the athletic condition of the best horses.

  5. Extracellular vesicles for drug delivery

    NARCIS (Netherlands)

    Vader, Pieter; Mol, Emma A; Pasterkamp, Gerard; Schiffelers, Raymond M

    2016-01-01

    Extracellular vesicles (EVs) are cell-derived membrane vesicles, and represent an endogenous mechanism for intercellular communication. Since the discovery that EVs are capable of functionally transferring biological information, the potential use of EVs as drug delivery vehicles has gained consider

  6. Study of the acid rain influence on the aluminium soil concentration near a coal fired power plant; Estudo da influencia da chuva acida na concentracao de aluminio em solos proximos a uma termoeletrica a carvao

    Energy Technology Data Exchange (ETDEWEB)

    Hama, Patricia

    2001-07-01

    Rainwater samples of a rural region around a coal plant in the northeast of Parana State (Brazil) were evaluated. Samples of bulk and wet deposition were analyzed during a one-year period (June 1999 - June 2000). A great number of rain events (70%) presented pH values below 5.6 (volume weight mean - VWM was pH = 4.9 {+-} 0.7), indicating that the region rainwater was lightly acid. The anions and cations concentrations results in the sampled rainwater showed a high sulphate concentration (69 {mu}eq L{sup -1}), followed by the cations concentration of sodium, calcium and ammonium (35, 32 and 30 {mu}eq L{sup -1}, respectively). The analysis of different data of the region showed that one probable source of the high sodium concentration could be from adsorbed sodium at the fly ash after the coal burning process. Due to the great contribution of these cations in the sulphate neutralization action, the rainwater of this region had only a lightly acid characteristic, which not caused a significant environmental impact. The study of the local soil showed that the soil characteristic was of an acid soil and bioavailable concentration of the alkaline (calcium, magnesium and potassium) and acid (aluminium) cations presented high calcium concentration [(1001{+-} 357) mg kg{sup -1}] compared with the other cations. The determination of the soil sensitivity to acid rain was calculated by the ratio BC/Al{sup 3+} (BC is the sum of the alkaline cations) and presented an average value of (5.1 {+-} 3.3). The preliminary evaluation of the soil susceptibility to acid rain by the ratio BC/Al{sup 3+}, showed that the local soil and type of vegetation (tropical savannah) were sensitive to acid deposition. A long term of this impacting condition (acid rain) could be harmful to the soil and vegetation quality. (author)

  7. Efeito da concentração de sais e fitorreguladores na indução de calos em carqueja Callus induction in "carqueja" as affected by salt concentrations and growth regulators

    Directory of Open Access Journals (Sweden)

    Fabiano Guimarães Silva

    2003-06-01

    Full Text Available Realizou-se este trabalho com o objetivo de estudar condições nutricionais e hormonais para maximizar a produção de calos friáveis de carqueja [Baccharis trimera (Less. DC]. Foi verificado que a iniciação de calo é dependente de fitorreguladores e da concentração do meio. A melhor indução de calo ocorreu em meio MS contendo 50% da concentração de sais, inositol e vitaminas, suplementado com 15,0 mM ANA. Proliferação de brotos foi obtida pelo uso de TDZ.The influence of various growth regulators and medium concentrations, in different quantities, on the in vitro callus induction of carqueja [Baccharis trimera (Less. DC.] was evaluated. It was found that the callus initiation was dependent on both, the growth regulator and medium concentration. The highest callus induction and development were obtained by using 15.0 mM 1-napthaleneacetic acid (NAA as growth regulators and half strength of salts, vitamins, and myo-inositol of Murashige and Skoog medium. In vitro shoot proliferation was obtained by using thidiazuron.

  8. Regulation of CFTR chloride channel macroscopic conductance by extracellular bicarbonate.

    Science.gov (United States)

    Li, Man-Song; Holstead, Ryan G; Wang, Wuyang; Linsdell, Paul

    2011-01-01

    The CFTR contributes to Cl⁻ and HCO₃⁻ transport across epithelial cell apical membranes. The extracellular face of CFTR is exposed to varying concentrations of Cl⁻ and HCO₃⁻ in epithelial tissues, and there is evidence that CFTR is sensitive to changes in extracellular anion concentrations. Here we present functional evidence that extracellular Cl⁻ and HCO₃⁻ regulate anion conduction in open CFTR channels. Using cell-attached and inside-out patch-clamp recordings from constitutively active mutant E1371Q-CFTR channels, we show that voltage-dependent inhibition of CFTR currents in intact cells is significantly stronger when the extracellular solution contains HCO₃⁻ than when it contains Cl⁻. This difference appears to reflect differences in the ability of extracellular HCO₃⁻ and Cl⁻ to interact with and repel intracellular blocking anions from the pore. Strong block by endogenous cytosolic anions leading to reduced CFTR channel currents in intact cells occurs at physiologically relevant HCO₃⁻ concentrations and membrane potentials and can result in up to ∼50% inhibition of current amplitude. We propose that channel block by cytosolic anions is a previously unrecognized, physiologically relevant mechanism of channel regulation that confers on CFTR channels sensitivity to different anions in the extracellular fluid. We further suggest that this anion sensitivity represents a feedback mechanism by which CFTR-dependent anion secretion could be regulated by the composition of the secretions themselves. Implications for the mechanism and regulation of CFTR-dependent secretion in epithelial tissues are discussed.

  9. Comportamento da Curva de Lactação de Cabras Mestiças Saanen em Função da Suplementação de Concentrado e do Sistema de Produção Lactation Curve Behavior of Cross Breed Saanen Dairy Goats in Function of the Concentrate Supplementation and the Production System

    Directory of Open Access Journals (Sweden)

    Vicente de Paulo Macedo

    2001-12-01

    Full Text Available Estudaram-se o comportamento da curva de lactação em 31 cabras mestiças Saanen e o efeito de duas estratégias de suplementação de concentrado: 30% das exigências em energia líquida da 3ª semana até o final da lactação (ESC.1; 60% das exigências em energia líquida diária da 3ª à 13ª semana, e 15% da 14ª semana até o final da lactação (ESC.2, em sistemas de produção semi-confinamento e pastagem. Os seguintes modelos foram avaliados: Wood linear e não-linear, Morant linear e não-linear, D-set e Grossman. O modelo Wood não linear foi o que melhor descreveu o comportamento da curva de lactação. A resposta da estratégia de suplementação com concentrado variou em função do sistema de produção. A estratégia de suplementação com concentrado afetou mais intensamente o comportamento da curva de lactação no sistema de produção semi-confinamento. A estratégia ESC.2, de suplementação com concentrado, resultou em mais dias para atingir o pico de produção, no sistema semi-confinamento, e maior produção no pico em ambos sistemas.The behavior of lactation curve of 31 crossbred Saanen dairy goats and the effect of two strategies of supplementation with concentrate: 30% of requirements in net energy from third week until the end of lactation (ESC.1; or 60% of requirements in daily net energy from the 3rd to the 13th week and 15% from 14th until the end of lactation (ESC.2, in a pasture or semi-confined systems, were studied. The following models were evaluated: Wood linear and non-linear, Morant linear and non-linear, D-set and Grossman. Non-linear Wood model was the best in describing the behavior of lactation curve. The responses to the strategy of supplementation with concentrate were different in function of production systems. The strategy of supplementation affected the behavior of lactation curve more intensely in the semi-confined system. The ESC.2 strategy of supplementation resulted in more days to reach

  10. Rendimento do tomate cereja em função do cacho floral e da concentração de nutrientes em hidroponia Yield of cherry tomatoes depending on the floral cluster and the concentration of nutrients in hydroponics

    Directory of Open Access Journals (Sweden)

    Marcelo de Q Rocha

    2010-12-01

    Full Text Available Neste trabalho avaliou-se os componentes do rendimento (número e peso médio de frutos por planta do tomate cereja cultivado em sistema hidropônico, no ciclo verão-outono de 2008, observando a influência da posição do cacho floral e da concentração de nutrientes da solução nutritiva. Foram estudadas quatro concentrações iônicas da solução nutritiva (condutividade elétrica inicial (CE: 1,3; 1,8; 2,3 e 2,8 dS m-1. Observou-se que não houve interação significativa entre os fatores concentração de nutrientes da solução nutritiva e posição do cacho floral para todos os componentes de rendimento avaliados. Em relação ao efeito da posição do cacho floral, verificou-se que somente para as variáveis índice de pegamento e produção de frutos, estes apresentaram influência significativa nas respostas observadas. A concentração iônica da solução nutritiva apresentou efeito significativo para as variáveis de rendimento peso médio do fruto e produção de frutos por planta. Em termos de peso médio de frutos, as CEs de 1,8 e 2,3 dS m-1 mostraram-se superiores à CE de 2,8 dS m-1 e similares à CE de 1,3 dS m-1, obtendo-se 13,0; 12,5; 9,5 e 10,9 g por fruto, respectivamente. A produção média de frutos das plantas cultivadas na solução nutritiva com CE de 1,8 dS m-1 (296,5 g cacho-1 e 2,1 kg planta-1 foram superiores às das demais condutividades avaliadas. Conclui-se que a posição do cacho floral na planta não afeta os componentes do rendimento número e peso médio do fruto, exercendo pouca influência sobre a produção de frutos por cacho do tomateiro cereja. Já, a variação da concentração iônica da solução nutritiva (na faixa entre 1,3 e 2,8 dS m-1 não afeta o número de frutos colhidos por planta, mas uma CE superior a 2,3 dS m-1 provoca uma redução no peso médio do fruto e, consequentemente, na produção de frutos por planta.The components of yield (number and average weight of fruits per plant

  11. Effect of succinic acid concentration in poly(glycerol citrate/succinate) properties; Efeito da concentracao do acido succinico nas propriedades do poli(glicerol citrato/succinato)

    Energy Technology Data Exchange (ETDEWEB)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Jose, Nadia M. [Universidade Federal da Bahia - UFBA, Instituto de Quimica, Salvador, BA (Brazil)

    2011-07-01

    In this work were prepared and characterized polymer based on glycerol, citric and succinic acid, in three different ratios to evaluate the effect of succinic acid concentration in materials properties. The polymers were obtained by polycondensation reaction between polyol and poly acids, and were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The materials are amorphous polyesters and its thermal and morphological properties change depending on the succinic acid concentration. (author)

  12. Antifungal performance of extracellular chitinases and culture supernatants of Streptomyces galilaeus CFFSUR-B12 against Mycosphaerella fijiensis Morelet.

    Science.gov (United States)

    Castillo, Benjamín Moreno; Dunn, Michael F; Navarro, Karina Guillén; Meléndez, Francisco Holguín; Ortiz, Magdalena Hernández; Guevara, Sergio Encarnación; Palacios, Graciela Huerta

    2016-03-01

    The tropical and mycoparasite strain Streptomyces galilaeus CFFSUR-B12 was evaluated as an antagonist of Mycosphaerella fijiensis Morelet, causal agent of the Black Sigatoka Disease (BSD) of banana. On zymograms of CFFSUR-B12 culture supernatants, we detected four chitinases of approximately 32 kDa (Chi32), 20 kDa (Chi20), and two with masses well over 170 kDa (ChiU) that showed little migration during denaturing electrophoresis at different concentrations of polyacrylamide. The thymol-sulphuric acid assay showed that the ChiU were glycosylated chitinases. Moreover, matrix assisted laser desorption ionization time-of-flight MS analysis revealed that the ChiU are the same protein and identical to a family 18 chitinase from Streptomyces sp. S4 (gi|498328075). Chi32 was similar to an extracellular protein from Streptomyces albus J1074 (gi|478687481) and Chi20 was non-significantly similar to chitinases from five different strains of Streptomyces (P > 0.05). Subsequently, Chi32 and Chi20 were partially purified by anion exchange and hydrophobic interaction chromatography and tested against M. fijiensis. Chitinases failed to inhibit ascospore germination, but inhibited up to 35 and 62% of germ tube elongation and mycelial growth, respectively. We found that crude culture supernatant and living cells of S. galilaeus CFFSUR-B12 were the most effective in inhibiting M. fijiensis and are potential biocontrol agents of BSD.

  13. Extracellular vesicles: Exosomes, microvesicles, and friends

    NARCIS (Netherlands)

    Raposo, G.; Stoorvogel, W.|info:eu-repo/dai/nl/074352385

    2013-01-01

    Cells release into the extracellular environment diverse types of membrane vesicles of endosomal and plasma membrane origin called exosomes and microvesicles, respectively. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for

  14. Extracellular enzyme kinetics scale with resource availability

    Science.gov (United States)

    Microbial community metabolism relies on external digestion, mediated by extracellular enzymes that break down complex organic matter into molecules small enough for cells to assimilate. We analyzed the kinetics of 40 extracellular enzymes that mediate the degradation and assimi...

  15. Neutrophil Extracellular Traps and Microcrystals

    Science.gov (United States)

    2017-01-01

    Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1–100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed. PMID:28373994

  16. Neutrophil Extracellular Traps and Microcrystals.

    Science.gov (United States)

    Rada, Balázs

    2017-01-01

    Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1-100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed.

  17. Neutrophil Extracellular Traps and Microcrystals

    Directory of Open Access Journals (Sweden)

    Balázs Rada

    2017-01-01

    Full Text Available Neutrophil extracellular traps represent a fascinating mechanism by which PMNs entrap extracellular microbes. The primary purpose of this innate immune mechanism is thought to localize the infection at an early stage. Interestingly, the ability of different microcrystals to induce NET formation has been recently described. Microcrystals are insoluble crystals with a size of 1–100 micrometers that have different composition and shape. Microcrystals have it in common that they irritate phagocytes including PMNs and typically trigger an inflammatory response. This review is the first to summarize observations with regard to PMN activation and NET release induced by microcrystals. Gout-causing monosodium urate crystals, pseudogout-causing calcium pyrophosphate dehydrate crystals, cholesterol crystals associated with atherosclerosis, silicosis-causing silica crystals, and adjuvant alum crystals are discussed.

  18. Análise comparativa da concentração industrial e de turnover da indústria farmacêutica no Brasil para os segmentos de medicamentos de marca e genéricos Comparative analysis of the Industrial Concentration and Turnover of the pharmaceutical industry in Brazil for the segments of mark and generic drugs

    Directory of Open Access Journals (Sweden)

    Gerson Rosenberg

    2010-04-01

    Full Text Available Este artigo analisa a evolução da estrutura do segmento de medicamentos de marca e genéricos no Brasil a partir de 1997. Após a entrada dos medicamentos genéricos, constatou-se que não houve diminuição significativa da concentração na indústria farmacêutica brasileira, porém, o mesmo não ocorreu em nível mundial, verificando-se um aumento da concentração a partir de 2001, impulsionado pelo expressivo processo de fusões e aquisições nos últimos anos da década de 1990. Em relação ao turnover, notou-se que este foi muito baixo para o grupo das maiores empresas em ambos os segmentos de medicamentos. Entretanto, observa-se um elevado turnover com a entrada dos genéricos, mostrando o fortalecimento da indústria nacional. Verifica-se que o processo de fusões e aquisições entre empresas nacionais é pouco significativo, o que pode ser uma alternativa para as pequenas empresas farmacêuticas aumentarem a sua participação no mercado brasileiro.This paper analyzes the evolution of brand-name and generic drugs structure in Brazil since 1997. After the introduction of generic drugs it was not verified a significant decrease in the concentration of Brazilian pharmaceutical industry. The process of mergers and acquisitions in the 90's enhanced the process of concentration in the international market. However, a non-expressive turnover can be demonstrated in both pharmaceutical and generic markets. At the same time, the entrance of the generic industry in Brazil explains the invigoration of the national industry. The mergers and acquisitions process in the pharmaceutical industry is quite intense in Europe and in the USA, although in Brazil it is still not significant.

  19. Extracellular secretion of recombinant proteins

    Science.gov (United States)

    Linger, Jeffrey G.; Darzins, Aldis

    2014-07-22

    Nucleic acids encoding secretion signals, expression vectors containing the nucleic acids, and host cells containing the expression vectors are disclosed. Also disclosed are polypeptides that contain the secretion signals and methods of producing polypeptides, including methods of directing the extracellular secretion of the polypeptides. Exemplary embodiments include cellulase proteins fused to secretion signals, methods to produce and isolate these polypeptides, and methods to degrade lignocellulosic biomass.

  20. Effect of extracellular calcium on the additive effect of theophylline on the cardiac response to catecholamine

    Directory of Open Access Journals (Sweden)

    Shamkuwar Prashant

    2008-01-01

    Full Text Available At different extracellular calcium concentrations, the positive inotropic effect of isoproterenol and isoproterenol in combination with theophylline, a phosphodiesterase inhibitor have been evaluated in the isolated frog heart and the isolated guinea pig left atria to investigate whether extracellular calcium produces any effect on the additive effect of the theophylline on the cardiac response to catecholamine. Cumulative dose response study of isoproterenol and isoproterenol in presence of theophylline at different extracellular calcium concentration was performed. The study revealed an increase in additive effect of theophylline on the cardiac response to catecholamine with increase in extracellular calcium concentration, but increase in extracellular calcium concentration decreased the myocardial responsiveness to additive effect of theophylline and isoproterenol combination. The mechanism of positive inotropic effect of isoproterenol and in combination with theophylline involves increase in intracellular cAMP by different pathways and extracellular calcium produces positive inotropic effect by initiating the interaction between the contractile proteins actin and myosin. The study revealed that an increase in the concentration of extracellular calcium increased the additive effect of theophylline and isoproterenol combination, but a decrease in the myocardial responsiveness was observed.

  1. EXTRACELLULAR POLYSACCHARIDES OF POTATO RING ROT PATHOGEN

    Directory of Open Access Journals (Sweden)

    Shafikova Т.N.

    2006-03-01

    Full Text Available Many bacteria, including phytopathogenic ones produce extracellular polysaccharides or exopolysaccharides which are universal molecules. Causal agent of potato ring rot, Clavibacter michiganensis subspecies sepedonicus, secretes exopolysaccharides which role in pathogenesis is poorly investigated. The aim of our research is to ascertain the composition and structure of Clavibacter michiganensis subspecies sepedonicus exopolysaccharides. Exopolysaccharides of Clavibacter michiganensis subspecies sepedonicus are determined to consist of 4-6 anionic and neutral components which have molecular weights from 700 kDa. Glucose is a major monomer of polysaccharides and arabinose, rhamnose and mannose are minor monomers. Glucose is present in α-Dglucopyranose and β-D-glucopyranose configurations. Calcium is determined to be a component of exopolysaccharides. Components of exopolysaccharides of potato ring rot pathogen are probably capableto associate via calcium ions and other ionic interactions that may result in a change of their physiological activity. Further studies of Clavibacter michiganensis subspecies sepedonicus exopolysaccharides composition and structure can serve a base for the synthesis of their chemical analogues with elicitor action.

  2. Force spectroscopy of hepatocytic extracellular matrix components

    Energy Technology Data Exchange (ETDEWEB)

    Yongsunthon, R., E-mail: YongsuntR@Corning.com [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States); Baker, W.A.; Bryhan, M.D.; Baker, D.E.; Chang, T.; Petzold, O.N.; Walczak, W.J.; Liu, J.; Faris, R.A.; Senaratne, W.; Seeley, L.A.; Youngman, R.E. [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States)

    2009-07-15

    We present atomic force microscopy and force spectroscopy data of live hepatocytes (HEPG2/C3A liver cell line) grown in Eagle's Minimum Essential Medium, a complex solution of salts and amino acids commonly used for cell culture. Contact-mode imaging and force spectroscopy of this system allowed correlation of cell morphology and extracellular matrix (ECM) properties with substrate properties. Force spectroscopy analysis of cellular 'footprints' indicated that the cells secrete large polymers (e.g., 3.5 {mu}m contour length and estimated MW 1000 kDa) onto their substrate surface. Although definitive identification of the polymers has not yet been achieved, fluorescent-labeled antibody staining has specified the presence of ECM proteins such as collagen and laminin in the cellular footprints. The stretched polymers appear to be much larger than single molecules of known ECM components, such as collagen and heparan sulfate proteoglycan, thus suggesting that the cells create larger entangled, macromolecular structures from smaller components. There is strong evidence which suggests that the composition of the ECM is greatly influenced by the hydrophobicity of the substrate surface, with preferential production and/or adsorption of larger macromolecules on hydrophobic surfaces.

  3. Characterization of a highly thermostable extracellular lipase from Lactobacillus plantarum.

    Science.gov (United States)

    Lopes, Maria de Fátima Silva; Leitão, Ana Lúcia; Regalla, Manuela; Marques, J J Figueiredo; Carrondo, Manuel José Teixeira; Crespo, Maria Teresa Barreto

    2002-06-01

    After screening for the presence of lipase activity in lactobacilli isolated from "chouriço", a traditional Portuguese dry fermented sausage, a strain of Lactobacillus plantarum (DSMZ 12028) was chosen for extracellular lipase characterisation and purification. Proteinase K did not significantly affect lipolytic activity, as opposed to trypsin, which completely eliminated this activity. Among NaCl, Ca2+, EDTA, BSA, glycerol, Mn2+ and Mg2+, only Mn2+ and Mg2+ stimulated the lipase. Purification by gel filtration chromatography and gel electrophoresis revealed four bands, between 98 and 45 kDa, all with lipolytic activity against olive oil.

  4. Purification and Characterization of an Extracellular Proteinase from Brevibacterium-Linens ATCC-9174

    DEFF Research Database (Denmark)

    Rattray, F P; Bockelmann, W; Fox, P F

    1995-01-01

    An extracellular serine proteinase from Brevibacterium linens ATCC 9174 was purified to homogeneity. pH and temperature optima were 8,5 and 50 degrees C, respectively. The results for the molecular mass of the proteinase were 56 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and...

  5. Interactions of human tenascin-X domains with dermal extracellular matrix molecules.

    NARCIS (Netherlands)

    Egging, D.; Berkmortel, F. van den; Taylor, G.; Bristow, J.; Schalkwijk, J.

    2007-01-01

    Tenascin-X (TNX) is a large 450 kDa extracellular matrix protein expressed in a variety of tissues including skin, joints and blood vessels. Deficiency of TNX causes a recessive form of Ehlers-Danlos syndrome characterized by joint hypermobility, skin fragility and hyperextensible skin. Skin of TNX

  6. Estudo da variação da concentração de metano no biogás produzido a partir das águas residuárias do café A study on the variation of methane concentration in biogas produced from coffee wastewater

    Directory of Open Access Journals (Sweden)

    Marco Antônio Calil Prado

    2010-04-01

    Full Text Available A água residuária do café (ARC, originada no processamento dos frutos do cafeeiro, produz quantidade considerável de biogás que pode e deve ser utilizado como fonte de energia alternativa e complementar. Neste trabalho, foi estudada a variação da concentração de metano do biogás produzido a partir das ARC, por tratamento anaeróbio, em reator UASB, em escala laboratorial. As amostras foram coletadas durante 86 dias. As análises da concentração de metano foram realizadas por cromatografia gás-sólido (CGS. A produção de biogás e de metano, foi de 0,545 a 0,602 m³ kg-1DQO removida e de 0,382 a 0,421 m³ kg-1 DQO removida, respectivamente. Os resultados da concentração de metano no biogás variaram de 48,60 a 68,14 %, influenciados pela variação dos parâmetros temperatura, pH, acidez e compostos fenólicos presentes nas ARC. Como havia sido previsto, as maiores concentrações de metano foram verificadas nos períodos em que o pH estava mais próximo da neutralidade.The wastewater produced from wet coffee processing (WCP, originated from the coffee fruits, can produce great quantities of biogas, which, in turn, can be also used as an alternative or complementary energy source. In this research, we studied the variation of methane concentration produced by WCP in a laboratory-scale UASB reactor with anaerobic treatment. The samples were collected during a period of 86 days. The methane concentration was measured through gas solid chromatography (GSC. The production of biogas and methane ranged from 0.545 to 0.602 m³ kg-1DQO removed and from 0.382 a 0.421 m³ kg-1 DQO removed, respectively. Methane presence in the biogas ranged from 48.60% to 68.14 %. This variation was influenced by the following parameters: temperature, pH, acidity, and phenol compounds present in the WCP. As expected, greater concentrations of methane gas were verified during the periods when the pH close to neutral.

  7. Calibração de extratores providos de cápsula porosa para monitoramento da salinidade e da concentração de íons Calibration of porous ceramic cup extractors in monitoring soil salinity and ion concentration

    Directory of Open Access Journals (Sweden)

    Francisco de A. de Oliveira

    2011-06-01

    Full Text Available Os resultados satisfatórios obtidos no monitoramento da salinidade e concentração de íons na solução do solo, usando extratores de cápsulas porosas, motivaram a realização deste trabalho, o qual teve como objetivo a obtenção de curvas de calibração para estes extratores monitorarem a condutividade elétrica e a concentração de nitrato e de potássio na solução de dois tipos de solo (Latossolo Vermelho-Amarelo Argissólico franco arenoso, e o outro como Cambissolo Eutrófico, em Mossoró - RN. As concentrações de nitrato utilizadas foram as mesmas nos dois solos (0; 84; 168; 252; 336; 420 e 504 mg L-1; quanto ao potássio, foram utilizadas concentrações diferentes no solo arenoso (0; 117; 234; 351; 468; 585 e 702 mg L-1 e no argiloso (0; 117; 234; 351; 468; 585; 702; 1.170; 1.755; 2.340; 2.925 e 3.510 mg L-1. A condutividade elétrica da solução do solo e a concentração de nitrato e de potássio foram estimadas com precisão satisfatória a partir da solução coletada com extratores providos de cápsulas porosas, sendo necessária uma calibração prévia para cada tipo de solo.The satisfactory results obtained in monitoring soil salinity and ion concentration, by means of porous ceramic cup extractors, motivated the realization of this study, which objective was obtaining calibration curves for these extractors to monitor soil electrical conductivity and concentration of nitrate and potassium in two different soils. The nitrate concentrations tested were the same for the two soils (0; 84; 168; 252; 336; 420 and 504 mg L-1 but, for potassium, different concentrations were used for sandy soil (0; 117; 234; 351; 468; 585 and 702 mg L-1 and clay soil (0; 117; 234; 351; 468; 585; 702; 1,170; 1,755; 2,340; 2,925 and 3,510 mg L-1. Electrical conductivity of soil solution and concentrations of nitrate and potassium were estimated with satisfactory precision from soil solution collected with porous ceramic cup extractors, but

  8. MK-801诱导的精神分裂症发育模型大鼠脑组织DA,DOPAC,Glu和GABA浓度的变化%Concentration change of DA, DOPAC, Glu and GABA in brain tissues in schizophrenia developmental model rats induced by MK-801

    Institute of Scientific and Technical Information of China (English)

    刘勇; 唐亚梅; 蒲唯丹; 张向晖; 赵靖平

    2011-01-01

    Objective To explore the related neurobiochemical mechanism by comparing the concentration change of dopamine (DA),dihydroxy-phenyl acetic acid (DOPAC),glutamate (Glu),and γ-aminobutyric acid (GABA) in the brain tissues in schizophrenia (SZ) developmental model rats and chronic medication model rats.Methods A total of 60 neonatal male Spragur-Dawley (SD) rats were randomly assigned to 3 groups at the postnatal day 6:an SZ developmental rat model group (subcutaneous injection with MK-801 at the postnatal day 7-10,0.1 mg/kg,Bid),a chronic medication model group (intraperitoneal injection at the postnatal day 47-60,0.2 mg/kg,Qd),and a normal control group (injection with O.9% normal saline during the corresponding periods).DA,DOPAC,Glu,and GABA of the tissue homogenate from the medial prefrontal cortex (mPFC) and hippocampus were examined with Coularray electrochemic detection by high performance liquid chromatogram technique.The utilization rate of DA and Glu was calculated.Results Compared with the normal control group,the concentration of DA and DOPAC in the mPFC and the hippocampus in the SZ developmental model group significantly decreased ( P < 0.05 ),and the GABA concentration and Glu utilization rate in the mPFC also decreased (P < 0.05 ).Compared with the chronic medication model group,the DA concentration of the mPFC in the SZ developmental group decreased ( P < 0.05 ),and the DOPAC concentration and the utility rate of DA in the hippocampus also decreased (P <0.01,P <0.05,respectively).Conclusion The activities of DA,Glu and GABA system decrease in the mPFC and the DA system function reduces in the hippocampus of SZ developmental rats.%目的:通过对MK-801诱导的精神分裂症(schizophrenia,SZ)发育模型大鼠和慢性给药模型大鼠脑组织多巴胺(dopamine,DA)、二羟苯乙酸(dihydroxy-phenyl acetic acid,DOPAC)、谷氨酸盐(glutamate,Glu)和γ-氨基丁酸(γ-aminobutyric acid,GABA)浓度的比较研究,探讨

  9. Protein concentrate obtainment from leaves and aerial part cassava (ManihotesculentaCrantzObtenção de concentrado protéico de folhas e parte aérea da mandioca (ManihotesculentaCrantz

    Directory of Open Access Journals (Sweden)

    Janaina Lima da Silva

    2012-12-01

    Full Text Available The aerial parts of cassava, constituted by leaves, stalk sand stems, are considered as agro-industrial waste, so, they are thrown away during roots crop. This material has content of protein, vitamin and mineral; therefore, it can be used as a dietary supplement for food industries. Thus, alternatives have come to extract protein from leaves and remove toxic agent sand anti-nutrients that make part of their composition. In this context, this study aimed at evaluating yield, mineral composition and functional properties of protein concentrates from leaves and aerial part of cassava. During the extraction of proteins, the following tested methods were:(1 isoelectric precipitation; (2 natural fermentation for five days; (3 fermentation for 48 hours and (4 fermentation for 48 hours, followed by pH adjustment. A 2 x 4 factorial design was used, the studied factors were the products (leaves and shoots and the method of protein extraction (four methods, with three replications. From the results, it was observed that Method1 provided the highest yields of protein concentrate and protein extraction for cassava leaves, however, there was no significant difference among the extraction methods for the aerial part of cassava. The values of Fe, Mn and Zn increased in protein concentrates obtained both in leaves and the aerial part of cassava, especially for Method 3. The capacities of absorbing water and oil from protein concentrates were considered high for the four studied methods, thus, indicating a good application in food products.As partes aéreas da mandioca, representadas pelas folhas, hastes e caules, constituem-se como resíduos agroindustriais por serem desperdiçadas na colheita das raízes. Esse material possui valor protéico, vitaminas e mineiras, propiciando sua utilização como suplemento alimentar nas indústrias alimentícias. Alternativas neste sentido surgem para extrair a proteína das folhas e eliminar os agentes tóxicos e

  10. Estimating microalgae Synechococcus nidulans daily biomass concentration using neuro-fuzzy network Estimador neuro-fuzzy de concentração diária de biomassa da microalga Synechococcus nidulans

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    Vitor Badiale Furlong

    2013-02-01

    Full Text Available In this study, a neuro-fuzzy estimator was developed for the estimation of biomass concentration of the microalgae Synechococcus nidulans from initial batch concentrations, aiming to predict daily productivity. Nine replica experiments were performed. The growth was monitored daily through the culture medium optic density and kept constant up to the end of the exponential phase. The network training followed a full 3³ factorial design, in which the factors were the number of days in the entry vector (3,5 and 7 days, number of clusters (10, 30 and 50 clusters and internal weight softening parameter (Sigma (0.30, 0.45 and 0.60. These factors were confronted with the sum of the quadratic error in the validations. The validations had 24 (A and 18 (B days of culture growth. The validations demonstrated that in long-term experiments (Validation A the use of a few clusters and high Sigma is necessary. However, in short-term experiments (Validation B, Sigma did not influence the result. The optimum point occurred within 3 days in the entry vector, 10 clusters and 0.60 Sigma and the mean determination coefficient was 0.95. The neuro-fuzzy estimator proved a credible alternative to predict the microalgae growth.Neste trabalho, foi construído um estimador neuro-fuzzy da concentração de biomassa da microalga Synechococcus nidulans a partir de concentrações iniciais da batelada, visando possibilitar a predição da produtividade. Nove experimentos em réplica foram realizados. O crescimento foi acompanhado diariamente pela transmitância do meio e mantido até o final da fase exponencial de crescimento. O treinamento das redes ocorreu segundo delineamento experimental 3³, os fatores foram o número de dias no vetor de entrada (3, 5 e 7 dias, o número de clusters (10, 30 e 50 clusters e o valor de abrandamento do filtro interno (Sigma (0,30, 0,45 e 0,60. A variável resposta foi o somatório do erro quadrático das validações. Estas possuíam 24 (A

  11. Estudo da vida-de-prateleira de fruta estruturada e desidratada obtida de polpa concentrada de mamão Shelf life studies of restructured and dried fruit made from concentrated papaya pulp

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    Regina Kitagawa Grizotto

    2006-09-01

    Full Text Available A fruta estruturada contendo polpa concentrada de mamão (700 g/kg, sacarose (340 g/kg, alginato de sódio (7 g/kg, pectina de baixa metoxilação (7 g/kg e glicerol (50 g/kg, cortada no formato cilindro sólido (vol. aprox. 2 cm³, desidratada (12% umidade, com cobertura de açúcar impalpável, foi utilizada no estudo de vida-de-prateleira. Foram realizadas análises físicas, químicas, sensoriais e microbiológicas no produto devidamente acondicionado em sacos de filme multilaminado, para acompanhar a evolução da perda de qualidade do produto armazenado a 0, 25 e 35 °C, durante 120 dias. Os resultados mostraram que a firmeza objetiva e as avaliações subjetivas da textura e qualidade global, foram as que melhor identificaram a queda na qualidade da fruta estruturada durante a estocagem. Na condição acelerada (35 °C, o produto foi considerado próprio para consumo até 56 dias de armazenamento, quando atingiu a nota 4,5 (não gostei/nem desgostei da escala de qualidade global do teste sensorial. Os dados cinéticos, Ea = 19,89 kcal/mol e Q10 = 3, estabelecidos no teste acelerado, permitiram estimar o limite da vida útil em 168 dias para o produto armazenado a 25 °C. Em condições normais de armazenamento, estimam-se 154 dias de vida útil com base na equação da qualidade global dos resultados sensoriais.The restructured fruit made with concentrated papaya pulp (700 g/kg, sugar (340 g/kg, sodium alginate (7 g/kg, low methoxy pectin (7 g/kg and glycerol (50 g/kg, cut in a solid cylindrical form (volume approx. 2 cm³, dehydrated (12% humidity and covered with icing sugar, was chosen for the shelf life studies. The physical, chemical, sensory and microbiological analyses were made on the product packaged in a multi layer film and stored at 0, 25 and 35 °C, for 120 days to check for quality loss. The results showed that the firmness (TA.XT2 Texturometer and the subjective evaluations of texture and overall quality were the evaluation

  12. Estudo da polimerização do 2-metil, 1,3-butadieno via catalisadores lantanídicos: influência do tipo de alquilalumínio, da temperatura reacional e da concentração do catalisador Polymerization of 2-methyl, 1,3-butadiene via lanthanides catalysts: influence from the type of alkylaluminum, concentration and reaction temperature and catalyst

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    André L. C. Simões

    2011-01-01

    Full Text Available Os catalisadores lantanídicos são muito eficientes na polimerização estereoespecífica de dienos, principalmente aqueles à base de neodímio. Neste trabalho será apresentado o estudo da polimerização do 2-metil, 1,3-butadieno com catalisadores à base de neodímio, utilizados comercialmente na polimerização do 1,3-butadieno. Foi estudado o efeito da temperatura, do tipo de alquilalumínio e da concentração de catalisador. As reações foram realizadas em reator de aço inox sob atmosfera inerte, usando como solvente o hexano e uma concentração de 2-metil, 1,3-butadieno de 12%. Foram obtidos polímeros com massas molares na faixa de 1,0 a 1,5 × 105 e teor de unidades repetitivas cis em torno de 97%.The rare earth metals catalysts are very efficient in stereospecific polymerization of dienes, especially those of neodymium. This paper reports on the polymerization of 2-methyl, 1,3-butadiene with catalysts of neodymium, used commercially in polymerization of 1,3-butadiene. Effects were studied from the temperature, type of alkylaluminum, and from the concentration of catalyst. The reactions were carried out in a stainless steel reactor under an inert atmosphere, using hexane as the solvent and a concentration of 12% of 2-methyl, 1,3-butadiene. Polymers were obtained with molecular weight from 1.0 to 1.5 × 105, with ca. 97% of cis repeating units.

  13. Extracellular DNA affects NO content in human endothelial cells.

    Science.gov (United States)

    Efremova, L V; Alekseeva, A Yu; Konkova, M S; Kostyuk, S V; Ershova, E S; Smirnova, T D; Konorova, I L; Veiko, N N

    2010-08-01

    Fragments of extracellular DNA are permanently released into the blood flow due to cell apoptosis and possible de novo DNA synthesis. To find out whether extracellular DNA can affect the synthesis of nitric oxide (NO), one of key vascular tone regulators, we studied in vitro effects of three artificial DNA probes with different sequences and 10 samples of extracellular DNA (obtained from healthy people and patients with hypertension and atherosclerosis) on NO synthesis in endothelial cell culture (HUVEC). For detection of NO in live cells and culture medium, we used a NO-specific agent CuFL penetrating into the cells and forming a fluorescent product FL-NO upon interaction with NO. Human genome DNA fragments affected the content of NO in endothelial cells; this effect depended on both the base sequence and concentration of DNA fragments. Addition of artificial DNA and extracellular DNA from healthy people into the cell culture in a low concentration (5 ng/ml) increased the detected NO concentration by 4-fold at most. Cytosine-guanine (CG)-rich fragment of the transcribed sequence of ribosomal repeat was the most powerful NO-inductor. The effect of DNA fragments on NO synthesis was comparable with that of low doses of oxidizing agents, H(2)O(2) and 17β-estradiol. Extracellular DNA samples obtained from patients with hypertension and atherosclerosis decreased NO content in cells and medium by 1.3-28 times compared to the control; the effect correlated with the content of CG-rich sequences.

  14. Digestibilidade da matéria seca de silagens de milho e de suplementos concentrados determinada por procedimentos in vitro Dry matter digestibility of corn silages and concentrates determined by in vitro procedures

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    F.C.F. Lopes

    2010-10-01

    Full Text Available Compararam-se os valores de digestibilidade in vitro da matéria seca (DIVMS de quatro silagens de milho e de seis concentrados (três proteicos e três energéticos, determinados pelo método de dois estádios realizados em tubos individuais ou em equipamento automatizado de fermentação, e avaliou-se a ocorrência de efeito associativo na digestão de alimentos destas três classes incubadas em um mesmo jarro de fermentação da incubadora in vitro, ou em jarros diferentes contendo a mesma classe de alimentos. Utilizou-se delineamento inteiramente ao acaso, em esquema fatorial 3 x 3 (procedimentos in vitro x classes de alimentos. Os valores de DIVMS determinados pelo método dos tubos foram mais próximos dos relatados na literatura e menores (P0,05 nos valores de DIVMS dos concentrados e das silagens de milho incubados no mesmo jarro de fermentação da incubadora ou, separadamente por alimento, em jarros diferentes.The values of in vitro dry matter digestibility (IVDMD of four corn silages and six concentrates (three proteic and three energetics were determined by the two-stage technique that utilizes individual digestion tubes and by an automatic equipment of fermentation (filter bag technique. It was also evaluated the associative effect on digestion of these three food classes when incubated in the same fermentation jar of the "in vitro incubator" and when in different vessels containing the same class of foods. The experimental design was completely randomized in a 3 x 3 factorial arrangement (in vitro procedures x food classes. The IVDMD values determined in tubes were closer to those found in the literature and lower (P0.05 in IVDMD of concentrates and silages when incubated together in the same fermentation jar or separated by food classes in separated jars.

  15. Extracellular ATP induces the release of calcium from intracellular stores without the activation of protein kinase C in Swiss 3T6 mouse fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, F.A.; Rozengurt, E.; Heppel, L.A. (Cornell Univ., Ithaca, NY (USA))

    1989-06-01

    Exposure of Swiss 3T6 mouse fibroblasts to extracellular ATP stimulated the formation of inositol phosphates and mobilized intracellular calcium. The mobilization of intracellular calcium was verified by imaging of fura-2 fluorescence in individual cells and by monitoring the efflux of {sup 45}Ca{sup 2+} from preloaded cells. However, the authors found no activation of protein kinase C as measured by phosphorylation of an 80-kDa acidic protein and by transmodulation of the receptor for epidermal growth factor. A careful examination of the kinetics of the phosphorylation reaction (from 30 sec to 10 min) revealed no activation of protein kinase C by extracellular ATP at any time. The lack of activation of protein kinase C was demonstrated even when a concentration of ATP 10-fold higher than that required to give a strong Ca{sup 2+} signal was used. Extracellular ATP did not inhibit protein kinase C activation by fetal bovine serum, platelet-derived growth factor, or phorbol esters. The effects of ATP were also produced by UTP but not by ADP, AMP, or adenosine. These findings demonstrate that it is possible to induce the mobilization of intracellular calcium by an inositol phosphate-mediated pathway without the activation of protein kinase C.

  16. Influência da concentração e da proporção fruto: xarope na desidratação osmótica de bananas processadas Influence of concentration and proportion fruit: syrup in the osmotic dehydration of processed bananas

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    Paulo Henrique Machado de Sousa

    2003-12-01

    Full Text Available Considerando-se as limitações tecnológicas dos processos tradicionais para produção de banana passa com uma qualidade padrão, a desidratação osmótica surge como uma opção à padronização deste processo. Neste trabalho visou-se determinar parâmetros do processo de desidratação osmótica da banana e avaliar a influência da concentração da solução osmótica nas características físico-químicas do fruto e construir as curvas de secagem da banana pré-tratada através de desidratação osmótica com e sem vácuo. Concluiu-se que é possível obter banana desidratada como produto de umidade intermediária, através de pré-tratamento osmótico seguido de secagem. As características do produto foram influenciadas pela concentração e proporção fruto:xarope do meio osmótico utilizado.Considering the technological limitations of the traditional processes for production of banana fig with standard quality, the osmotic dehydration appears as an option to the standardization of this process. In this work to determine parameters of the banana osmotic dehydration process and to evaluate the influence of osmotic solution concentration on the physical chemical caracteristics of the fruit and stablish drying curves of pre treatment bananas through osmotic dehydration with and without vacuum. It was concluded that is possible to obtain dehydrated banana as a product of intermediate moisture, through osmotic pre treatment followed by drying. The characteristics of the product were influenced by concentration and proportion fruit:xyrop of the used medium.

  17. CONCENTRAÇÃO DE b -GLUCANAS NAS DIFERENTES ETAPAS DO PROCESSAMENTO DA AVEIA (Avena sativa L. OAT (Avena sativa L. b -GLUCAN CONCENTRATION IN DIFFERENT PROCESSING STAGES

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    Roberta Marins DE SÁ

    1998-10-01

    Full Text Available As b-glucanas são fibras solúveis presentes em grande quantidade na aveia e têm importante ação na redução do colesterol sangüíneo em indivíduos com hipercolesterolemia, entre outras propriedades. Pouco se conhece em relação a este polímero em produtos brasileiros. Além disso, para ser consumida, a aveia passa por várias etapas de processamento, que poderiam alterar seu conteúdo de b-glucanas. Este trabalho avaliou a concentração de b-glucanas no cultivar de aveia IAC 7 e seus produtos, para verificar se existe alteração no teor desta fibra no decorrer do processamento. O farelo apresentou o maior teor de b-glucanas (9,51± 2,08%, diferindo estatisticamente dos demais produtos (Pb-glucanas dos demais produtos avaliados (aveia descascada, tostada, cortada, flocos inteiros, flocos e flocos finos, indicando que o processamento não tem influência no teor desta fibra no produto final.. b-glucans are soluble fibers which are quite abundant in oats. One of their many important properties is their capacity to lower blood cholesterol in individuals with hipercholesterolemy. Very little is known about this polymer in Brazilian food products. Besides, in order to be consumed as human food, the oats have to undergo several processing steps that may alter their original b-glucan concentration. The aim of this study was to measure this nutrient in cultivar IAC 7 and its products to determine if processing had any influence on the overall b-glucan content. Oat bran presented the highest values (9.51± 2.08% and was found to be significantly different from the other products (Pb-glucan contents of the other products, suggesting that processing had minimum or no effect on the concentration of this fiber.

  18. Differential effects of pyrethroid insecticides on extracellular dopamine in the striatum of freely moving rats.

    Science.gov (United States)

    Mubarak Hossain, Muhammad; Suzuki, Tadahiko; Sato, Norio; Sato, Itaru; Takewaki, Tadashi; Suzuki, Koichi; Tachikawa, Eiichi; Kobayashi, Haruo

    2006-11-15

    In order to obtain a more complete understanding of pyrethroid neurotoxicity, effects of the pyrethroid insecticides, allethrin (type I), cyhalothrin (type II) and deltamethrin (type II) on extracellular levels of dopamine (DA) and its metabolites in the striatum of conscious rats were studied by in vivo microdialysis. Rats were treated i.p. with pyrethroids or vehicle. Allethrin had a dual effect on DA release. The increase in the extracellular level of striatal DA by 10 mg/kg allethrin reached a maximum of 178% of baseline but 20 and 60 mg/kg inhibited DA release to 63% and 52% of baseline with a peak effect at 60-80 min after injection. Cyhalothrin 10, 20 and 60 mg/kg inhibited DA release to 65%, 56% and 45% of basal release, respectively, with a peak time of inhibition 40-80 min past injection. Deltamethrin (10 and 20 mg/kg) increased DA release to maximum of 187% and 252% of basal release whereas 60 mg/kg first reduced the efflux for 40 min to 50% of basal release and then increased the efflux to a maximum of 344% of basal release with a peak time of 120 min. Local infusion of 1 microM tetrodotoxin, a Na(+) blocker through the dialysis probe completely prevented the effect of allethrin (10 and 60 mg/kg), cyhalothrin (60 mg/kg) and deltamethrin (20 mg/kg) on DA release but only partially blocked the effects of 60 mg/kg deltamethrin. The effect of deltamethrin (60 mg/kg) on DA release was completely prevented by local infusion of 10 microM nimodipine, an L-type Ca(++) channel blocker. All three pyrethroids did not alter the extracellular levels of DOPAC, 3-MT and HVA except that 20 and 60 mg/kg of allethrin and cyhalothrin increased 3-MT levels. Effect of the pyrethroids on synaptosomal DA uptake was also examined. The DA uptake was decreased in rats exposed to 60 mg/kg of allethrin and cyhalothrin but was increased in rats exposed to 60 mg/kg of deltamethrin. Our results demonstrate that striatal DA release and DA uptake are differentially affected by type I

  19. Role of extracellular cations in cell motility, polarity, and chemotaxis

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    Soll D

    2011-04-01

    Full Text Available David R Soll1, Deborah Wessels1, Daniel F Lusche1, Spencer Kuhl1, Amanda Scherer1, Shawna Grimm1,21Monoclonal Antibody Research Institute, Developmental Studies, Hybridoma Bank, Department of Biology, University of Iowa, Iowa City; 2Mercy Medical Center, Surgical Residency Program, Des Moines, Iowa, USAAbstract: The concentration of cations in the aqueous environment of free living organisms and cells within the human body influence motility, shape, and chemotaxis. The role of extracellular cations is usually perceived to be the source for intracellular cations in the process of homeostasis. The role of surface molecules that interact with extracellular cations is believed to be that of channels, transporters, and exchangers. However, the role of Ca2+ as a signal and chemoattractant and the discovery of the Ca2+ receptor have demonstrated that extracellular cations can function as signals at the cell surface, and the plasma membrane molecules they interact with can function as bona fide receptors that activate coupled signal transduction pathways, associated molecules in the plasma membrane, or the cytoskeleton. With this perspective in mind, we have reviewed the cationic composition of aqueous environments of free living cells and cells that move in multicellular organisms, most notably humans, the range of molecules interacting with cations at the cell surface, the concept of a cell surface cation receptor, and the roles extracellular cations and plasma membrane proteins that interact with them play in the regulation of motility, shape, and chemotaxis. Hopefully, the perspective of this review will increase awareness of the roles extracellular cations play and the possibility that many of the plasma membrane proteins that interact with them could also play roles as receptors.Keywords: extracellular cations, chemotaxis, transporters, calcium, receptors

  20. Extracellular nucleotide signaling in plants

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, Gary [Univ. of Missouri, Columbia, MO (United States)

    2016-09-08

    Over the life of this funded project, our research group identified and characterized two key receptor proteins in plants; one mediating the innate immunity response to chitin and the other elucidating the key receptor for extracellular ATP. In the case of chitin recognition, we recently described the quaternary structure of this receptor, shedding light on how the receptor functions. Perhaps more importantly, we demonstrated that all plants have the ability to recognize both chitin oligomers and lipochitooligosacchardes, fundamentally changing how the community views the evolution of these systems and strategies that might be used, for example, to extend symbiotic nitrogen fixation to non-legumes. Our discovery of DORN1 opens a new chapter in plant physiology documenting conclusively that eATP is an important extracellular signal in plants, as it is in animals. At this point, we cannot predict just how far reaching this discovery may prove to be but we are convinced that eATP signaling is fundamental to plant growth and development and, hence, we believe that the future will be very exciting for the study of DORN1 and its overall function in plants.

  1. Influência da concentração de BAP e AG3 no desenvolvimento in vitro de mandioquinha-salsa Influence of BAP and GA3 concentration on the in vitro development of arracacha

    Directory of Open Access Journals (Sweden)

    Nuno R. Madeira

    2005-12-01

    Full Text Available Foram realizados dois experimentos com o objetivo de avaliar o efeito das concentrações de BAP e de AG3 no desenvolvimento in vitro de mandioquinha-salsa. Foram avaliadas as concentrações de 0,0; 0,2 e 0,4 mg L-1 de BAP e de 0,0; 0,125 e 0,250 mg L-1 de AG3 no desenvolvimento de ápices caulinares com cerca de 2 mm das cultivares Amarela de Senador Amaral e Amarela Comum. A interação cultivares x concentração de BAP não foi significativa para nenhuma das características avaliadas (P>0,0617. O aumento na concentração de BAP reduziu a formação de calos; entretanto, promoveu proporcionalmente redução no desenvolvimento da parte aérea. A concentração de BAP que apresentou os melhores resultados foi em torno de 0,3 mg L-1 de BAP, conciliando diâmetro de calo relativamente reduzido e bom desenvolvimento da parte aérea, cerca de 4,5 brotos com altura média de 43 mm. A interação cultivares x concentração de AG3 não foi significativa para nenhuma das características avaliadas (P>0,4310. O aumento na concentração de AG3 promoveu elevação significativa na altura média e máxima das brotações e aumento no tamanho de calos. Nos dois experimentos, observou-se maior número de brotações na cultivar Amarela Comum.Two experiments were carried out to evaluate the effect of BAP and GA3 concentrations on the in vitro arracacha development. The concentrations tested were 0.0; 0.2 and 0.4 mg L-1 of BAP and 0.0; 0.125 and 0.250 mg L-1 of GA3 in the shoot tips with about 2 mm of arracacha, cultivars Amarela de Senador Amaral and Amarela Comum. The interaction of cultivars x BAP concentration was not significant for any one of the evaluated variables (P>0,0617. The increase in the BAP concentration reduced the callus formation; however, promoted larger reduction in the shoot development. The best BAP concentration was around 0.3 mg L-1, with relatively reduced callus diameter and good development of shoot, with a mean of 4.5 shoots

  2. Teor de taninos em três espécies medicinais arbóreas simpátricas da caatinga Tannin concentration in three simpatric medicinal plants from caatinga vegetation

    Directory of Open Access Journals (Sweden)

    Julio Marcelino Monteiro

    2005-12-01

    Full Text Available O teor de taninos em três espécies medicinais do semi-árido do Nordeste do Brasil foi determinado. A partir de amostras das cascas do caule e folhas de 10 indivíduos de Anadenanthera colubrina (Vell. Brenam, Myracrodruon urundeuva (Engl. Fr. All. e Caesalpinia pyramidalis Tul., os teores de fenóis totais e taninos foram determinados em extratos metanólicos 80% pelo método de Folin-Ciocalteau, seguido do método da precipitação de proteínas. Adicionalmente, testou-se a hipótese de que a concentração de taninos está diretamente relacionada com a altura e diâmetro das plantas. As espécies estudadas apresentaram expressivos teores de extrativos tânicos, e os resultados não ratificaram a hipótese testada.A comparative study of tannin concentration in three medicinal plants from caatinga vegetation (Northeast Brazil was carried out through colorimetric assays. Bark and leaf samples of 10 individuals of each species were extracted with 80% methanol. Tannin was determined by Folin-Ciocalteau analysis for total phenolic materials, followed by precipitation with casein. Additionally, it was tested the hypothesis that the tannin concentration is directly related with the height and diameter of the plants. The results show that the studied species contain an expressive amount of tannins.

  3. DEGRADABILIDADE IN SITU DA MATÉRIA SECA, DA PROTEÍNA BRUTA E DA FRAÇÃO FIBROSA DE CONCENTRADOS E SUBPRODUTOS AGROINDUSTRIAIS IN SITU DEGRADABILITY OF DRY MATTER, CRUDE PROTEIN AND FIBROUS FRACTION OF CONCENTRATE AND AGROINDUSTRIAL BY-PRODUCTS

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho Carvalho

    2009-09-01

    Full Text Available Objetivou-se avaliar a degradabilidade ruminal da matéria seca (MS, da proteína bruta (PB, da fibra em detergente neutro (FDN e da fibra em detergente ácido (FDA do milho (Zea mays, do farelo de soja (Glicyne max L., da torta de dendê (Elaeis guineensis Jacq. e do farelo de cacau (Theobroma cacao L.. Incubaram-se amostras de cada alimento no rúmen de três novilhos por períodos de 0; 3; 6; 12; 24 e 48 horas. As degradabilidades efetivas da MS, PB, FDN e FDA, para a taxa de passagem de 5%/hora, foram relativamente baixas (abaixo de 60%, exceto para a PB do farelo de soja (acima de 65%. O farelo de soja apresentou os maiores coeficientes de degradação, tanto para MS e PB como também para os constituintes da parede celular, seguido do milho, torta de dendê e farelo de cacau. O farelo de cacau apresentou as menores taxas de degradação ruminal.

    PALAVRAS-CHAVES: Farelo de cacau, incubação ruminal, torta de dendê. The objective of the experiment was to evaluate the dry matter (DM, crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF ruminal degradability of corn (Zea mays, soybean meal (Glicyne max L., palm kernel cake (Elaeis guineensis Jacq. and cocoa meal (Theobroma cacao L.. Samples of each feed were incubated in rumens of three steers for periods of 0; 3; 6; 12; 24 and 48 hours. The DM, CP, NDF and ADF effective degradabilities, for a passage rate of 5%/hour, were relatively low (lower than 60%, except for soybean meal CP (higher than 65%. Soybean meal showed the greatest degradation coefficients for DM and CP as so as for cellular wall constituents, followed by corn, palm kernel cake and cocoa meal. Cocoa meal showed the lowest ruminal degradation rates.

    KEY WORDS: Cocoa meal, incubation ruminal, palm kernel cake.

  4. High-level extracellular production and characterization of Candida antarctica lipase B in Pichia pastoris.

    Science.gov (United States)

    Eom, Gyeong Tae; Lee, Seung Hwan; Song, Bong Keun; Chung, Keun-Wo; Kim, Young-Wun; Song, Jae Kwang

    2013-08-01

    The gene encoding lipase B from Candida antarctica (CalB) was expressed in Pichia pastoris after it was synthesized by the recursive PCR and cloned into the Pichia expression plasmid, pPICZαA. The CalB was successfully secreted in the recombinant P. pastoris strain X-33 with an apparent molecular weight of 34 kDa. For 140 h flask culture, the dry cell weight and the extracellular lipase activity reached at 5.4 g/l and 57.9 U/l toward p-nitrophenyl palmitate, respectively. When we performed the fed-batch fermentation using a methanol feeding strategy for 110 h, the dry cell weight and the extracellular lipase activity were increased to 135.7 g/l and 11,900 U/l; the CalB protein concentration was 1.18 g/l of culture supernatant. The characteristics of CalB recovered from the P. pastoris culture were compared with the commercial form of CalB produced in Aspergillus oryzae. The kinetic constants and specific activity, the effects of activity and stability on temperature and pH, the glycosylation extent, the degree of immobilization on macroporous resin and the yield of esterification reaction between oleic acid and n-butanol were almost identical to each other. Therefore, we successfully proved that the Pichia-based expression system for CalB in this study was industrially promising compared with one of the most efficient production systems.

  5. Influência da temperatura do ar de secagem e da concentração de agente carreador sobre as propriedades físico-químicas do suco de açaí em pó Influence of drying air temperature and carrier agent concentration on the physicochemical properties of açai juice powder

    Directory of Open Access Journals (Sweden)

    Renata Valeriano Tonon

    2009-06-01

    Full Text Available A influência da temperatura do ar de secagem e da concentração de agente carreador sobre as propriedades físico-químicas do suco de açaí em pó produzido por spray drying foi avaliada. O processo foi realizado em um mini spray dryer de bancada e maltodextrina 10DE foi utilizada como agente carreador. A temperatura do ar de secagem variou de 138 a 202 °C e a concentração de maltodextrina variou de 10 a 30%. As características analisadas foram: umidade, higroscopicidade, retenção de antocianinas, cor, distribuição do tamanho de partículas e morfologia. O aumento da temperatura resultou em partículas maiores, menos úmidas, mais higroscópicas e com menor retenção de antocianinas, além de provocar uma diminuição do parâmetro de cor L* e do ângulo de tom H*. O aumento na concentração de maltodextrina resultou em partículas maiores e menos higroscópicas, com maior luminosidade (L*, menores valores de C* e maiores valores de H*. Em relação à morfologia, o aumento da temperatura levou à formação de uma maior quantidade de partículas com superfície lisa, fato atribuído à maior transferência de calor e, consequentemente, à formação mais rápida de uma membrana ao redor da gota atomizada.The objective of this work was to study the influence of inlet air temperature and maltodextrin concentration on the physicochemical properties of açai juice powder produced by spray drying. The process was carried out in a mini spray dryer and the maltodextrin 10DE was used as carrier agent. Inlet air temperature varied from 138 to 202 °C and maltodextrin concentration varied from 10 to 30%. The characteristics analyzed were: moisture content, hygroscopicity, anthocyanin retention, color, particle size distribution, and morphology. The increase in the temperature resulted in particles with larger size, less moisture content, more hygroscopy and with lower anthocyanin retention, besides promoting a reduction in the color

  6. Densidade de plantio na produtividade e nos teores de nutrientes nas folhas e frutos da bananeira cv. Thap Maeo Plants density on yield and nutrients concentration in leaves and fruits of banana cv. Thap Maeo

    Directory of Open Access Journals (Sweden)

    Adônis Moreira

    2007-01-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito da densidade de plantio na produtividade, tempo de colheita e teores dos nutrientes nas folhas e nos frutos de bananeira cv. Thap Maeo (AAB cultivada em Manaus (AM. O delineamento experimental foi o de blocos casualizados, com três repetições. Os tratamentos foram constituídos pelos fatores: três densidades de plantio (1.111; 1.667 e 3.333 plantas ha-1 e duas épocas de colheita (primeiro e segundo ciclos. Os resultados do primeiro e segundo ciclos mostraram incremento significativo da produtividade, com aumento da densidade de plantio. O tempo médio para colheita dos cachos foi menor na densidade de 1.111 plantas ha-1 (1º ciclo, 338 e 2º ciclo, 401 dias. Na média das densidades e independentemente do ciclo, os teores de macronutrientes nos frutos apresentaram a ordem de: K>N>P>Mg>Ca=S, enquanto a dos micronutrientes foi: 1º ciclo - Cl>Fe>Mn=B>Zn>Cu e 2º ciclo - Cl>Fe>Zn>B=Mn>Cu.This study aimed to evaluate the effect of plants density on yield, period of harvest and nutrients concentration in leaves and fruits of banana cv. Thap Maeo (AAB, cultivated in Manaus, State of Amazonas, Brazil. The experiment was conduced in a randomized blocks, with three replicates. Treatments were comprised of planting density (1,111; 1,667 and 3,333 plants ha-1, and two cycles of harvest (sub treatments. The results obtained from 1st cycle and 2nd cycle showed significant increase in the yield per unit area as the employed plant density increased. The shortest average period to harvest banana bunches (1st cycle, 338 days and 2nd cycle, 401 days was observed for the lower density (1,111 plants ha-1. Pooled data of density and cycles showed that exportation of macronutrients through the fruits was, in order: K>N>P>Mg>Ca=S, while in micronutrients was: 1st cycle - Cl>Fe>Mn=B>Zn>Cu, and 2nd cycle - Cl>Fe>Zn>B=Mn>Cu.

  7. Efeito da concentração de ácido lático sobre a propriedade de expansão em amidos modificados fotoquimicamente Effect of lactic acid concentration on expansion property of photochemically modified starches

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    Ana Carolina Dal Bianco Garcia

    2005-06-01

    Full Text Available Uma característica valorizada pelo setor alimentício é a propriedade de expansão dos grânulos de amido. Com este trabalho, teve-se por objetivo avaliar o efeito da concentração de ácido lático durante tratamento de modificação fotoquímica das féculas de batata-doce (Ipomoea batatas, biri (Canna edulis, mandioca (Manihot esculenta e taioba (Xanthosoma sagittifolium. Pelos resultados obtidos neste experimento, nas condições em que este foi realizado, conclui-se que a concentração de ácido lático interferiu na propriedade de expansão das féculas de batata-doce, mandioca e taioba e não apresentou efeito na fécula de biri, devendo ser ajustado para cada tipo de fécula a ser modificada. Os índices de expansão obtidos nas diferentes féculas foram considerados baixos, quando comparados aos índices obtidos para fécula de mandioca modificada.The expansion property of starch granules is of great importance to the food industries. The effect of lactic acid concentration during photochemical treatment of sweet potato (Ipomoea batatas, edible canna (Canna edulis, cassava (Manihot esculenta and cocoyam (Xanthosoma sagittifolium starches was evaluated. The results showed that the acid concentration influenced the expansion property of sweet potato, cassava and cocoyam starches, but no differences were observed in edible canna starch, so that the acid concentration must be adjusted for each starch. The expansion ranges observed in all starches were lower that in modified cassava starch.

  8. Nutrients concentrations in the flag leaf and grains of black-oat affected by phosphate and potassium fertilization / Teores de nutrientes da folha bandeira e grãos de aveia-preta em função da adubação fosfatada e postássica

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    Claudemir Zucareli

    2009-12-01

    Full Text Available A aveia-preta (Avena strigosa Schreber tem sido comumente utilizada para adubação verde, rotação de culturas no sistema de plantio direto, em cultivo no outono-inverno e ainda, para pastejo, fenação e ensilagem. O objetivo deste trabalho foi avaliar os teores de macro e micronutrientes da folha bandeira e dos grãos de aveia-preta cv. Comum em função da adubação fosfatada e potássica. O experimento foi realizado em condições de campo, em Nitossolo Vermelho, em Botucatu-SP. Os tratamentos constaram de três doses de superfosfato simples (0, 40 e 80 kg ha-1 de P2O5 e três doses de cloreto de potássio (0, 20 e 40 kg ha-1 de K2O dispostos em esquema fatorial (3 x 3, sob o delineamento de blocos casualizados, com quatro repetições. A adubação foi feita no sulco de semeadura. Em todas as parcelas foi aplicado sulfato de amônio, sendo 20 kg ha-1 de N na semeadura e 30 kg ha-1 em cobertura no final do perfilhamento. Os teores de Ca, Mg, S, Fe, Mn, Cu e Zn da folha bandeira e de P e K dos grãos foram influenciados pela adubação fosfatada. A adubação potássica não influenciou os teores de macro e micronutrientes da folha bandeira e dos grãos em aveia preta.The black oat (Avena strigosa Schreber has been commonly used as green manure, in crop rotation systems under no-tillage, fall-winter crop, and for cattle grazing, hay, and silage. The objective of this work was to evaluate the nutrient concentrations in the flag leaf and grains of black-oat affect by phosphate and potassium fertilization. The experiment was carried out under field conditions on a Rhodic Nitosol, in Botucatu, São Paulo State, Brazil. Three doses of single superphosphate (0, 40 and 80 kg.ha-1 of P2O5 and three of potassium chloride (0, 20 and 40 kg ha-1 of K2O were tested as a factorial (3 x 3, in a randomized complete block design, with four replicates. The fertilizers were applied in the sowing row. Ammonium sulphate was supplied for all plots (20 kg ha-1

  9. Efeito da idade e sexo sobre a concentração sérica de eritropoietina em equinos da raça Árabe Effect of age and gender about the serum concentration of eritropoetin in Arabian horses

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    Joandes Henrique Fonteque

    2012-12-01

    Full Text Available A EPO é um fator de crescimento glicoprotéico sintetizado pelas células adjacentes aos túbulos proximais renais regulada via mecanismo de "feed back" envolvendo a tensão de oxigênio tissular. Na baixa tensão de oxigênio arterial, a produção de EPO aumenta causando uma maior produção de eritrócitos na medula óssea. Devido ao pouco conhecimento da concentração de EPO sérica em equinos e a ausência de trabalhos sobre o efeito da idade e sexo sobre a sua concentração o trabalho teve como objetivo comparar a concentração sérica de eritropoietina em equinos da raça Árabe de sexos e idades diferentes. Foram utilizados 31 equinos da raça Árabe, com idades de seis a 12 meses (jovens e acima de 24 meses (adultos, sendo 13 machos (seis jovens e sete adultos e 18 fêmeas (oito jovens e 10 adultas, clinicamente sadios. As amostras de sangue foram colhidas por venipunção jugular e o soro armazenado até o momento do processamento. A concentração sérica de eritropoetina foi determinada pelo método de radioimunoensaio (RIA utilizando kit comercial (EPO Trac TM125I RIA, Diagnostic Systems Laboratories, Webster, Texas, USA. Para análise estatística dos dados utilizou-se o Teste t de Student ao nível de 5% de significância (PThe erythropoietin (EPO is a glicoproteic grow factor synthesized by the adjacent cells in the proximal renal tubes and controlled by feedback mechanism that involve the tension of tissular oxygen. In the presence of low tension of arterial oxygen, the production of EPO increases and it causes a major production of erythrocytes in the marrowbone. Due to poor knowledge of the serum concentration of erythropoietin in equines and the absence of information about the differences between age and gender, the aim of this study was to compare the serum concentration of erythropoietin in Arabian horses, clinically healthy with different age and gender. A total of 31 horses were used from 6 to 12 months old (young

  10. Extracellular Ca2+ is a danger signal activating the NLRP3 inflammasome through G protein-coupled calcium sensing receptors

    DEFF Research Database (Denmark)

    Rossol, Manuela; Pierer, Matthias; Raulien, Nora;

    2012-01-01

    Activation of the NLRP3 inflammasome enables monocytes and macrophages to release high levels of interleukin-1ß during inflammatory responses. Concentrations of extracellular calcium can increase at sites of infection, inflammation or cell activation. Here we show that increased extracellular cal......, and this effect was inhibited in GPRC6A(-/-) mice. Our results demonstrate that G-protein-coupled receptors can activate the inflammasome, and indicate that increased extracellular calcium has a role as a danger signal and amplifier of inflammation....

  11. Analysis of extracellular RNA by digital PCR

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    Kenji eTakahashi

    2014-06-01

    Full Text Available The transfer of extracellular RNA is emerging as an important mechanism for intracellular communication. The ability for the transfer of functionally active RNA molecules from one cell to another within vesicles such as exosomes enables a cell to modulate cellular signaling and biological processes within recipient cells. The study of extracellular RNA requires sensitive methods for the detection of these molecules. In this methods article, we will describe protocols for the detection of such extracellular RNA using sensitive detection technologies such as digital PCR. These protocols should be valuable to researchers interested in the role and contribution of extracellular RNA to tumor cell biology.

  12. Extracellular Molecules Involved in Cancer Cell Invasion

    Energy Technology Data Exchange (ETDEWEB)

    Stivarou, Theodora; Patsavoudi, Evangelia, E-mail: epatsavoudi@pasteur.gr [Department of Biochemistry, Hellenic Pasteur Institute, Athens 11521 (Greece); Technological Educational Institute of Athens, Egaleo, Athens 12210 (Greece)

    2015-01-26

    Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  13. Extracellular Molecules Involved in Cancer Cell Invasion

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    Theodora Stivarou

    2015-01-01

    Full Text Available Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  14. Hidrólise da uréia em latossolos: efeito da concentração de uréia, temperatura, pH, armazenamento e tempo de incubação Urea hydrolysis in oxisols: effects of substrate concentration, temperature, pH, incubation time and storage conditions

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    Regina Marcia Longo

    2005-07-01

    Full Text Available Este trabalho objetivou estudar a velocidade de hidrólise da uréia em dois diferentes solos brasileiros (Latossolo Vermelho Aluminoférrico típico e Latossolo Vermelho distrófico típico onde foram realizados ensaios sobre o efeito do tempo e condições de armazenamento, concentração do substrato (uréia, temperatura, pH e tempo de incubação sobre a atividade da urease. As melhores condições de armazenamento foram em temperatura ambiente ou 5 ºC, após secagem ao ar, por um período de até 7 dias; para as condições estudadas, o melhor tempo de incubação foi de uma hora a 25-30 ºC, sem a utilização de tampão para acertar o pH, e a concentração de uréia suficiente foi de 3,30 g L-1, para o Latossolo Vermelho Aluminoférrico típico, e de 2,5 g L-1, para o Latossolo Vermelho distrófico típico para obter a velocidade máxima da enzima.This study evaluated the kinetics of urease hydrolysis in two different Brazilian soils (Rhodic Oxisols: a typic alumino-ferric Red Latossol and a typic distrophic Red Latosol. The trials were carried out to study the effects of air drying, soil sampling, storage conditions and temperature, pH, time of incubation, and substrate concentration on the urease activity. Results showed that best conditions for soil sample storage after air-drying for a 7-day period were at room temperature or at a temperature of 5 ºC. For the studied conditions the best incubation time was one hour at 25-30 ºC, without pH buffering. The ideal urea concentration suggested for the detection of the maximum velocity was 3.3 g L-1 for the typic alumino-ferric Red Latossol and 2.5 g L-1 for the typic distrophic Red Latosol.

  15. EFECTO DE LA ADMINISTRACIÓN INTRACEREBRAL DE MK-801 Y (- NICOTINA EN LAS CONCENTRACIONES EXTRACELULARES DE GLU Y GABA EN EL NÚCLEO PEDUNCULOPONTINO DE RATAS Effect of the Mk801 and (- Nicotine Intracerebral Administration on Glu and Gaba Extracellular Concentration in the Pedunculopontine Nucleus from Rats

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    LISETTE BLANCO LEZCANO

    Full Text Available Aunque la manipulación farmacológica de los sistemas glutamatérgico y colinérgico se ha tratado en modelos experimentales de enfermedad de Parkinson (EP, pocos autores han realizado estudios de esta temática a nivel del núcleo pedunculopontino (NPP. El presente trabajo aborda los cambios en las concentraciones extracelulares (CE de glutamato (Glu y ácido δ-amino butírico (GABA en el NPP de ratas hemiparkinsonizadas por inyección de 6-hidroxidopamina (6-OHDA y sometidas a infusión local de MK-801 (10 µmol/L o (- nicotina (10 mM. La infusión se realizó mediante microdiálisis cerebral y la determinación de CE de neurotransmisores se realizó a través de cromatografía líquida de alta resolución acoplada a detección de fluorescencia. La infusión de MK-801 en el NPP produjo disminución significativa de CE de Glu (pAlthough the pharmacological manipulation of the glutamatergic and cholinergic systems have been studied in animal models of Parkinson´s disease (PD, only some authors have done work on this topic at the pedunculopontine nucleus (PPN. The present work studied the changes in glutamate (Glu and δ-aminobutyric acid (GABA extracellular concentrations (EC in the PPN from hemiparkinsonian rats by 6hydroxydopamine injection. The rats were locally perfused by MK-801 (10 µmol/L or (- nicotine (10 mM solutions by cerebral microdyalisis. The biochemical studies were carried out through high performance liquid chromatography coupled to fluorescence detection. MK-801 infusion induced a significant decrease of Glu (p< 0.01 and GABA (p< 0.01 EC in PPN. On the other hand (- nicotine infusion induced a significant increase of Glu (p< 0.001 and GABA (p< 0.001 EC in PPN from hemiparkinsonian rats. The local blockade of NMDA receptors by MK-801 infusion facilitates the interaction between Glu and their metabotropic receptors that take part in presynaptic inhibition mechanisms and interfere with neurotransmitters release. Meanwhile, the

  16. Composição física da carcaça de bezerros da raça Holandesa alimentados com dietas contendo diferentes níveis de concentrado Carcass physical composition of Holstein calves fed diets with different levels of concentrate

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    Ricardo Dias Signoretti

    1999-08-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito dos diferentes níveis de concentrado nas dietas sobre a composição física da carcaça. Trinta e dois bezerros da raça Holandesa, PC, variedade preto e branco, divididos em dois grupos de abate (grupo 1: 16 animais abatidos com 190 ± 10 kg PV e grupo 2: 16 animais abatidos com 300 ± 10 kg, com, em média, 75 dias de idade e 78 kg PV inicial, foram distribuídos em delineamento inteiramente casualizado, com quatro tratamentos e quatro repetições para ambos os grupos. Os animais foram alimentados à vontade com dietas contendo 45,0; 60,0; 75,0; e 90,0% de concentrado na base da ração (% MS, usando-se feno de capim coast-cross (Cynodon dactylon, fubá de milho e farelo de soja, os quais constituíram dietas com aproximadamente 16% PB. A cada período de 28 dias, os animais foram pesados e abatidos quando se aproximavam do peso de abate preestabelecido para os grupos 1 e 2. A proporção de ossos na carcaça dos animais do grupo 1 não foi influenciada, porém a de músculos diminuiu e a de gordura e as relações tecido adiposo:ósseo e tecido adiposo:muscular aumentaram linearmente, em função dos níveis de concentrado nas rações. O aumento do nível de concentrado nas rações influenciou somente a relação tecido muscular:ósseo na carcaça dos animais do grupo 2.The objective of this study was to evaluate the effect of different dietary levels of concentrate on the carcass physical composition. Thirty two pure Holstein black and white type bull calves, into two slaughter groups (group 1: 16 animals slaughtered with 190 ± 10 kg PV and group 2: 16 animals slaughtered with 300 ± 10 kg with average of 75 days of age and initial 75 kg LW were allotted to a completely randomized design, with four treatments and four replicates for both groups. The animals were full fed diets containing 45.0, 60.0, 75.0, and 90.0% concentrate in the diet (% DM, using coast-cross (Cynodon dactylon grass hay

  17. Trypanocidal activity of genotoxic concentration of benznidazole on epimastigote forms of Trypanosoma cruzi = Atividade tripanocida da concentração genotóxica do benzonidazol em formas epimastigotas de Trypanosoma cruzi

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    Edilson Nobuyoshi Kaneshima

    2012-10-01

    Full Text Available The genotoxicity of benznidazole at a concentration of 75 µM, used in the treatment of Chagas’ disease, has been recently reported. The present study evaluated the inhibitory effect of benznidazole on the growth of epimastigote forms of T. cruzi I and II by using genotoxic (75 µM and non-genotoxic (50 µM concentrations. To assess the growth rates of T. cruzi strains G2, A2.1A, CL, Y, and 2052, parasites in the epimastigote form were cultured in LIT medium for 192 h at 28ºC, with (50 and 75 µM and without (negative control benznidazole. Benznidazole at both concentrations inhibited all the strains, regardless of genetic group. In the 75 µM concentration, there was a significant decrease in the number of parasites inoculated at T0 after 96 h incubation. The results showed that although genotoxic and non-genotoxic doses of benznidazole inhibit the growth of the epimastigote forms of T. cruzi I and II, only the 75 µM dose seem to indicate a possible trypanocidal effect.O benzonidazol é um medicamento utilizado no tratamento da doença de Chagas, cuja genotoxicidade foi recentemente observada em concentrações a partir de 75 µM. O efeito inibitório do benzonidazol sobre o crescimento de formas epimastigotas de T. cruzi I e II foi avaliado no presente trabalho, utilizando-se concentrações genotóxica (75 µM e não genotóxica (50 µM deste medicamento. Para avaliação da taxa de crescimento das cepas G2, A2.1A, CL, Y e 2052, os parasitos na forma epimastigota foram cultivados em meio LIT, durante 192 horas, à 28 o C, tanto em presença de benzonidazol (50 e 75 µM, quanto em sua ausência (controle negativo. O efeito inibitório do benzonidazol, em ambas concentrações, foi observado para todas as cepas analisadas, independentemente do grupo genético a que pertençam. Na concentração de 75 µM, observou-se após 96 horas de incubação, redução significativa do número de parasitos inoculados no tempo zero (T0. Os resultados

  18. Study of the proteins in the defatted flour and protein concentrate of baru nuts (Dipteryx alata Vog Estudo das proteínas da farinha desengordurada e concentrado protéico de castanhas de baru (Dipteryx alata Vog

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    Rita de Cássia Avellaneda Guimarães

    2012-09-01

    Full Text Available Baru (Dipteryx alata Vog. is an abundant legume in the Brazilian Savanna. Its nuts can be exploited sustainably using its protein and lipid fractions. This study aimed to analyze the proteins of the nuts present in the defatted flour and protein concentrate in terms of their functional properties, the profile of their fractions, and the in vitro digestibility. The flour was defatted with hexane and extracted at the pH of higher protein solubility to obtain the protein concentrate. The electrophoretic profile of the protein fractions was evaluated in SDS-PAGE gel. The functional properties of the proteins indicate the possibility of their use in various foods, like soybeans providing water absorption capacity, oil absorption capacity, emulsifying properties, and foamability. Globulins, followed by the albumins, are the major fractions of the flour and protein concentrate, respectively. Digestibility was greater for the concentrate than for the defatted flour.O baru (Dipteryx alata Vog. é uma leguminosa abundante no Cerrado brasileiro, cuja castanha pode ser explorada através do uso sustentável para o aproveitamento das frações proteicas e lipídicas. Este trabalho teve como objetivo estudar as proteínas desta castanha, presentes na farinha desengordurada e no concentrado proteico, quanto as suas propriedades funcionais, ao perfil das frações proteicas e à digestibilidade in vitro. A farinha desengordurada com hexano foi submetida à extração no pH de maior solubilidade das proteínas, obtendo-se o concentrado proteico. O perfil eletroforético das frações proteicas foi avaliado em gel de SDS-PAGE. As propriedades funcionais indicaram a possibilidade de emprego em diversos alimentos, assim como a soja, conferindo capacidade de absorção de água, capacidade de absorção de óleo, propriedades emulsificantes e espumabilidade. As globulinas, seguidas das albuminas, são as frações majoritárias da farinha e do concentrado proteico

  19. Controle genético da concentração de 2-Tridecanona e de 2-Undecanona em cruzamentos interespecíficos de tomateiro Genetic control of 2-Tridecanone and 2-Undecanone concentration in tomato interspecific cross

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    NORMA ELIANE PEREIRA

    2000-01-01

    Full Text Available Estudou-se o controle genético da concentração das metil-cetonas 2-tridecanona (2-TD e 2-undecanona (2-UN no cruzamento de Lycopersicon esculentum cv IPA-6 x L. hirsutum f. glabratum PI 134418. Para tal, as gerações parentais F1 e F2 foram avaliadas em experimento de casa de vegetação, sendo a quantificação das metil-cetonas foliares realizada por cromatografia gasosa com coluna capilar. Os resultados revelaram alta correlação (0,97; P > 0,001 entre as concentrações de 2-TD e 2-UN, possivelmente devido à ocorrência de efeitos pleiotrópicos ou de ligação gênica. O grau médio de dominância revelou a ocorrência de dominância parcial para as menores concentrações de 2-TD e 2-UN, cujas herdabilidades foram 0,75 e 0,78 respectivamente. A análise de média de gerações mostrou não haver adequação dos dados de concentração de 2-TD e 2-UN ao modelo aditivo-dominante, devido, possivelmente, a problemas de incongruidade ou a efeitos epistáticos.Genetic control of methyl-ketones 2-tridecanone (2-TD and 2-undecanone (2-UN concentration was studied in a cross of Lycopersicon esculentum cv IPA-6 x L. hirsutum f. glabratum PI 134418. The progenitors F1 and F2 generations were evalueted in a green house experiment, and the level of methyl-ketones in the leaves were determined by capilar gas chromatography. The results indicate that there is high correlations between 2-TD and 2-UN concentrations (0.97; P > 0.001, indicating that pleiotropic or genic linkage effects may be occurring. The 2-TD and 2-UN showed complete dominance for low concentration and high heritability, 0.75 and 0.78, respectively. The generation means analysis showed that the results of 2-TD and 2-UN concentration can not be explained by the simple additive-dominant model, suggesting that the segregation distortion could be due to incongruity problems of interspecific crosses or epistatic gene action.

  20. Extracellular proteases of Halobacillus blutaparonensis strain M9, a new moderately halophilic bacterium

    Science.gov (United States)

    Santos, Anderson F.; Valle, Roberta S.; Pacheco, Clarissa A.; Alvarez, Vanessa M.; Seldin, Lucy; Santos, André L.S.

    2013-01-01

    Halophilic microorganisms are source of potential hydrolytic enzymes to be used in industrial and/or biotechnological processes. In the present study, we have investigated the ability of the moderately halophilic bacterium Halobacillus blutaparonensis (strain M9), a novel species described by our group, to release proteolytic enzymes. This bacterial strain abundantly proliferated in Luria-Bertani broth supplemented with 2.5% NaCl as well as secreted proteases to the extracellular environment. The production of proteases occurred in bacterial cells grown under different concentration of salt, ranging from 0.5% to 10% NaCl, in a similar way. The proteases secreted by H. blutaparonensis presented the following properties: (i) molecular masses ranging from 30 to 80 kDa, (ii) better hydrolytic activities under neutral-alkaline pH range, (iii) expression modulated according to the culture age, (iv) susceptibility to phenylmethylsulphonyl fluoride, classifying them as serine-type proteases, (v) specific cleavage over the chymotrypsin substrate, and (vi) enzymatic stability in the presence of salt (up to 20% NaCl) and organic solvents (e.g., ether, isooctane and cyclohexane). The proteases described herein are promising for industrial practices due to its haloalkaline properties. PMID:24688526

  1. Extracellular proteases of Halobacillus blutaparonensis strain M9, a new moderately halophilic bacterium

    Directory of Open Access Journals (Sweden)

    Anderson F. Santos

    2013-12-01

    Full Text Available Halophilic microorganisms are source of potential hydrolytic enzymes to be used in industrial and/or biotechnological processes. In the present study, we have investigated the ability of the moderately halophilic bacterium Halobacillus blutaparonensis (strain M9, a novel species described by our group, to release proteolytic enzymes. This bacterial strain abundantly proliferated in Luria-Bertani broth supplemented with 2.5% NaCl as well as secreted proteases to the extracellular environment. The production of proteases occurred in bacterial cells grown under different concentration of salt, ranging from 0.5% to 10% NaCl, in a similar way. The proteases secreted by H. blutaparonensis presented the following properties: (i molecular masses ranging from 30 to 80 kDa, (ii better hydrolytic activities under neutral-alkaline pH range, (iii expression modulated according to the culture age, (iv susceptibility to phenylmethylsulphonyl fluoride, classifying them as serine-type proteases, (v specific cleavage over the chymotrypsin substrate, and (vi enzymatic stability in the presence of salt (up to 20% NaCl and organic solvents (e.g., ether, isooctane and cyclohexane. The proteases described herein are promising for industrial practices due to its haloalkaline properties.

  2. Extracellular DNA in oral microbial biofilms.

    Science.gov (United States)

    Jakubovics, Nicholas S; Burgess, J Grant

    2015-07-01

    The extracellular matrix of microbial biofilms is critical for surface adhesion and nutrient homeostasis. Evidence is accumulating that extracellular DNA plays a number of important roles in biofilm integrity and formation on hard and soft tissues in the oral cavity. Here, we summarise recent developments in the field and consider the potential of targeting DNA for oral biofilm control.

  3. Rastreamento de cardiopatias congênitas associadas ao diabetes mellitus por meio da concentração plasmática materna de frutosamina Congenital cardiopathies screening associated with diabetes mellitus using maternal fructosamine plasma concentration

    Directory of Open Access Journals (Sweden)

    Zilma Silveira Nogueira Reis

    2010-02-01

    Full Text Available OBJETIVO: avaliar a importância da concentração plasmática materna de frutosamina como indicador de cardiopatias congênitas fetais, em gestações complicadas pelo diabetes mellitus. MÉTODOS: o estudo retrospectivo incluiu 91 gestantes portadoras de diabetes mellitus, as quais foram submetidas à ecocardiografia fetal de rotina em centro universitário de referência em Medicina Fetal. Foram selecionadas 65 pacientes que apresentavam diabete pré-gestacional e registro em prontuário médico de frutosamina plasmática anterior ao exame ultrassonográfico. A primeira dosagem registrada foi confrontada com o resultado da ecocardiografia fetal de rotina, realizada por médico especialista do serviço. A presença ou ausência de achados ecográficos de cardiopatia congênita (AECC foi relacionada aos níveis plasmáticos de frutosamina, por meio de teste de médias, e sua acuidade para AECC verificada por curva ROC. Foram discutidos como pontos de corte os valores da concentração plasmática materna de frutosamina de 2,68, 2,9 e 2,23 mmol/L, que são, respectivamente, o valor de referência local do laboratório, o do kit de dosagem empregado e o de maior acurácia global. RESULTADOS: o AECC foi encontrado em 52,3% dos fetos. A primeira dosagem de frutosamina durante o pré-natal aconteceu em média com 20,4±8,0 semanas de gestação. A capacidade da concentração materna de frutosamina em identificar fetos com AECC foi significante (pPURPOSE: to evaluate the importance of maternal plasma concentration of fructosamine as an indicator of fetal congenital cardiopathies in pregnancies complicated by diabetes mellitus. METHODS: this was a retrospective study conducted on 91 pregnant women with diabetes mellitus who underwent routine fetal echocardiography at a university reference center in fetal medicine. Sixty-five patientes who presented pre-gestational diabetes mellitus and plasma fructosamine level were registered in the medical records

  4. Influência da aplicação de fertilizantes, na concentração de nutrientes em folhas de pimenteira-do-reino The influence of applications of fertilizer on foliar concentrations of nutrients of black pepper

    Directory of Open Access Journals (Sweden)

    Ondino C Bataglia

    1976-07-01

    Full Text Available Procedeu-se à análise de folhas coletadas no verão, outono e inverno, num ensaio de adubação qualitativa instalado na Estação Experimental de Pariquera Açu, do Instituto Agronômico, com o objetivo de avaliar o efeito da aplicação de fertilizantes na absorção de nutrientes pela pimenteira-do-reino. A amostragem de verão revelou efeito dos tratamentos sobre os teores de fósforo, potássio e cobre, sendo por isso recomendada para fins de diagnose foliar. Apenas para potássio houve aumento de concentração nas folhas quando se compararam as médias dos tratamentos com e sem cada um dos nutrientes.A field trial was conducted since 1965 at the Pariquera Açu Experiment Station, State of São Paulo, to study the effects of the presence and absence of fertilizer on black pepper (Piper nigrum L.. In 1973, recently mature leaves were collected in summer, fall and winter in order to verify the effects of the treatments on the foliar concentration of macro and micronutrients. Summer sampling showed effect of fertilizer treatments on the concentration of phosphorus, potassium, and copper. Fall sampling showed effect only for potassium and no effect was observed in the winter. When the average contents of nutrients from fertilized and not fertilized treatments were compared, only potassium revealed differences by the Scheffé test.

  5. Towards traceable size determination of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Zoltán Varga

    2014-02-01

    Full Text Available Background: Extracellular vesicles (EVs have clinical importance due to their roles in a wide range of biological processes. The detection and characterization of EVs are challenging because of their small size, low refractive index, and heterogeneity. Methods: In this manuscript, the size distribution of an erythrocyte-derived EV sample is determined using state-of-the-art techniques such as nanoparticle tracking analysis, resistive pulse sensing, and electron microscopy, and novel techniques in the field, such as small-angle X-ray scattering (SAXS and size exclusion chromatography coupled with dynamic light scattering detection. Results: The mode values of the size distributions of the studied erythrocyte EVs reported by the different methods show only small deviations around 130 nm, but there are differences in the widths of the size distributions. Conclusion: SAXS is a promising technique with respect to traceability, as this technique was already applied for traceable size determination of solid nanoparticles in suspension. To reach the traceable measurement of EVs, monodisperse and highly concentrated samples are required.

  6. Problemas da sociologia da arte

    OpenAIRE

    Bastide, Roger

    2006-01-01

    A partir de um balanço das realizações consideradas pelo autor como as mais relevantes no campo da sociologia da arte até o final dos anos de 1940, o texto propõe novos rumos para a disciplina, considerando o modo como a arte é socialmente produzida como linguagem e valor.

  7. Estimativa da concentração espermática do sêmen de peixe pelo método de espermatócrito Sperm concentration estimate of fish semen using spermatocrit method

    Directory of Open Access Journals (Sweden)

    Eduardo Antônio Sanches

    2011-06-01

    Full Text Available Um experimento foi realizado com o objetivo de estimar a concentração espermática das espécies dourado (Salminus brasiliensis, curimba (Prochilodus lineatus, jundiá (Rhamdia quelen, cascudo-preto (Rhinelepis aspera e tilápia-do-nilo (Oreochromis niloticus pelo método de espermatócrito. Utilizaram-se 19, 58, 51, 43 e 85 reprodutores de dourado, curimba, jundiá, cascudo-preto e tilápia-do-nilo, respectivamente. Com exceção da tilápia-do-nilo, os reprodutores foram submetidos ao processo de indução hormonal e posteriormente submetidos a coleta de sêmen. Foram comparadas as técnicas de mensuração da concentração espermática do sêmen por contagem em câmara hematimétrica de Neubauer e por espermatócrito. Os resultados obtidos foram submetidos à análise de regressão a 5% de probabilidade. As concentrações espermáticas mensuradas por ambas as técnicas apresentaram relação linear, para curimbas, jundiás e tilápias-do-nilo, com equações y = 6,6624 × 10(9 + 3,68553 × 10(8x; y = 2,153 × 10(9 + 4,426 × 10(8x e y = -9,0897 × 10(8 + 6,0167 × 10(8, respectivamente. O método de espermatócrito pode ser utilizado para estimar a concentração espermática do sêmen de curimbas, jundiás e tilápias-do-nilo.The objective of this experiment was estimate sperm concentration of "dourado" (Salminus brasiliensis, "curimba" (Prochilodus lineatus, "jundiá" (Rhamdia quelen, "cascudo-preto" (Rhinelepis aspera and Nile tilapia (Oreochromis niloticus by the method of spermatocrit. It was used 19, 58, 51, 43 and 85 brood fish of "dourado", "curimba", "jundia", "cascudo-preto" and Nile tilapia, respectively. Except for the Nile tilapia, the fishes were subjected to the hormonal induction process and then submitted to the semen collection. The measurement techniques of the sperm concentration by sperm count in Neubauer chamber (CSPZ and by spermatocrit (ESPMT were compared. The results were submitted to the regression analysis at 5

  8. Ratiometric Imaging of Extracellular pH in Dental Biofilms.

    Science.gov (United States)

    Schlafer, Sebastian; Dige, Irene

    2016-03-09

    The pH in bacterial biofilms on teeth is of central importance for dental caries, a disease with a high worldwide prevalence. Nutrients and metabolites are not distributed evenly in dental biofilms. A complex interplay of sorption to and reaction with organic matter in the biofilm reduces the diffusion paths of solutes and creates steep gradients of reactive molecules, including organic acids, across the biofilm. Quantitative fluorescent microscopic methods, such as fluorescence life time imaging or pH ratiometry, can be employed to visualize pH in different microenvironments of dental biofilms. pH ratiometry exploits a pH-dependent shift in the fluorescent emission of pH-sensitive dyes. Calculation of the emission ratio at two different wavelengths allows determining local pH in microscopic images, irrespective of the concentration of the dye. Contrary to microelectrodes the technique allows monitoring both vertical and horizontal pH gradients in real-time without mechanically disturbing the biofilm. However, care must be taken to differentiate accurately between extra- and intracellular compartments of the biofilm. Here, the ratiometric dye, seminaphthorhodafluor-4F 5-(and-6) carboxylic acid (C-SNARF-4) is employed to monitor extracellular pH in in vivo grown dental biofilms of unknown species composition. Upon exposure to glucose the dye is up-concentrated inside all bacterial cells in the biofilms; it is thus used both as a universal bacterial stain and as a marker of extracellular pH. After confocal microscopic image acquisition, the bacterial biomass is removed from all pictures using digital image analysis software, which permits to exclusively calculate extracellular pH. pH ratiometry with the ratiometric dye is well-suited to study extracellular pH in thin biofilms of up to 75 µm thickness, but is limited to the pH range between 4.5 and 7.0.

  9. A High-Fat Meal, or Intraperitoneal Administration of a Fat Emulsion, Increases Extracellular Dopamine in the Nucleus Accumbens

    Directory of Open Access Journals (Sweden)

    Bartley G. Hoebel

    2012-06-01

    Full Text Available Evidence links dopamine (DA in the nucleus accumbens (NAc shell to the ingestion of palatable diets. Less is known, however, about the specific relation of DA to dietary fat and circulating triglycerides (TG, which are stimulated by fat intake and promote overeating. The present experiments tested in Sprague-Dawley rats whether extracellular levels of NAc DA increase in response to acute access to fat-rich food or peripheral injection of a fat emulsion and, if so, whether this is related to caloric intake or elevated circulating lipids. When rats consumed more calories of a high-fat meal compared with a low-fat meal, there was a significant increase in extracellular accumbens DA (155% vs. 119%. Systemic injection of a fat emulsion, which like a high-fat diet raises circulating TG but eliminates the factor of taste and allows for the control of caloric intake, also significantly increased extracellular levels of DA (127% compared to an equicaloric glucose solution (70% and saline (85%. Together, this suggests that a rise in circulating TG may contribute to the stimulatory effect of a high-fat diet on NAc DA.

  10. Performance of holsteins cows in pasture of Cynodon dactylon cv. Coast-cross supplemented with concentrate Desempenho de vacas da raça Holandesa em pastagem de Cynodon dactylon cv. Coast-cross suplementada com concentrado

    Directory of Open Access Journals (Sweden)

    Rodrigo Carvalho Cardoso

    2009-12-01

    Full Text Available The work was developed in the experimental station of Embrapa Gado de Leite (Dairy Cattle Embrapa, in Coronel Pacheco, in Zona da Mata Region of Minas Gerais, with the purpose of evaluating the productive performance of Holstein cows kept on 'Coast-cross' (Cynodon dactylon (L. Pears pasture, fertilized, strategically irrigated and where the cows were daily supplemented with 3 or 6 kg of concentrate/cow/day. The data were collected during three years (October/2000 to October/2003, involving 108 lactations. An experimental randomized block design with two replicate areas per treatment was adopted, with nine animals per area and eighteen animals per treatment being utilized, with fixed stocking rate of five cows/ha. The system of grazing, under rotated stocking, with one day occupation of the enclosures (piquetes and 25 and 35 days rest in the rainy and dry seasons, respectively was used. The pasture was irrigated in the months of lowest rainfall and fertilized with NPK broadcast at six applications/year. The availability of dry matter of the pasture was 7,280 kg/ha and 6,167 kg/ha in early grazing, with the post-grazing waste stubble of 4,885 kg/ha and 3,994 kg/ha, in the rainy (Spring/Summer and dry (Fall/Winter seasons, respectively. During part of the experimental period, a few morphogenic characteristics of the pasture were evaluated, recording availability of 83.9; 125.6 and 89.5 kg of DM of leaf blades/ha/day, on spring, summer and fall, respectively. The daily averages of milk production per cow were 15.57 and 18.80 kg/ day with 3.5% of fat and per area 77.80 and 94.00 kg/ha, when 3 or 6 kg of concentrate/cow/day were fed, respectively. It was concluded that supplemented and managed 'Coast-cross' pasture adequately enables high milk production per animal and per area, as quantitatively and qualitatively adequate for milk production.O trabalho foi desenvolvido na base física da Embrapa Gado de Leite, em Coronel Pacheco, na Zona da Mata de

  11. Protective immunity against tuberculosis induced by vaccination with major extracellular proteins of Mycobacterium tuberculosis.

    OpenAIRE

    1995-01-01

    Tuberculosis, caused by the intracellular pathogen Mycobacterium tuberculosis, is the world's leading cause of death in humans from a single infectious agent. A safe and effective vaccine against this scourge is urgently needed. This study demonstrates that immunization with the 30-kDa major secretory protein, alone or in combination with other abundant extracellular proteins of M. tuberculosis, induces strong cell-mediated immune responses and substantial protective immunity against aerosol ...

  12. CONCENTRAÇÃO PLASMÁTICA DE TESTOSTERONA EM RUFIÕES EQÜINOS DA RAÇA MANGALARGA PLASMIC CONCENTRATION OF TESTOSTERONE IN MANGALARGA STALLION TEASERS

    Directory of Open Access Journals (Sweden)

    Luiz Altamiro Garcia Nogueira

    2007-09-01

    Full Text Available

    O objetivo deste trabalho foi determinar a concentração plasmática de testosterona em rufiões eqüínos da raça Mangalarga. Utilizaram-se 15 eqüinos, não castrados, com idade variando de 38 a 55 meses, separados em três grupos de cinco animais. O Grupo 1 foi utilizado para controle e os Grupos II e III foram transformados em rufiões pelo método de circuncisão com encurtamento do pênis. Não foi observada diferença estatisticamente significativa nos níveis plasmáticos do hormônio entre garanhões e rufiões e nem entre as diferentes épocas de avaliação.

    PALAVRAS-CHAVE: Eqüino; testosterona; rufião.

    The plasmic concentration of testosterone in Mangaiarga stallions teasers was estimated to be compared to stallions, in different seasons. Fifteen stallions divided into 3 groups of 5 animals each were used. Group I was used as control, and all animals from groups II and III were made teasers by the method of circumcision with penis shortening. No diferences were observed.

    KEY-WORDS: Equine; testosterone; teasers.

  13. Differential contribution of storage pools to the extracellular amount of accumbal dopamine in high and low responders to novelty: effects of reserpine.

    NARCIS (Netherlands)

    Verheij, M.M.M.; Cools, A.R.

    2007-01-01

    The present study examined the effects of reserpine on the extracellular concentration of accumbal dopamine in high responders (HR) and low responders (LR) to novelty rats. Reserpine reduced the baseline concentration of extracellular accumbal dopamine more in HR than in LR, indicating that the dopa

  14. and extracellular laccase isoenzymes from Pleurotus ostreatus ...

    African Journals Online (AJOL)

    ZMG

    Colonia Vicentina, Delegación Iztapalapa, 09340 México D.F., México. ... In this study, extracellular laccase enzymes produced by Pleurotus ostreatus was identified in .... the intracellular forms), through the modified zymography method of.

  15. Alternative methods for characterization of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Fatemeh eMomen-Heravi

    2012-09-01

    Full Text Available Extracellular vesicles are nano-sized vesicles released by all cells in vitro as well as in vivo. Their role has been implicated mainly in cell-cell communication, but also in disease biomarkers and more recently in gene delivery. They represent a snapshot of the cell status at the moment of release and carry bioreactive macromolecules such as nucleic acids, proteins and lipids. A major limitation in this emerging new field is the availability/awareness of techniques to isolate and properly characterize Extracellular vesicles. The lack of gold standards makes comparing different studies very difficult and may potentially hinder some Extracellular vesicles -specific evidence. Characterization of Extracellular vesicles has also recently seen many advances with the use of Nanoparticle Tracking Analysis (NTA, flow cytometry, cryo-EM instruments and proteomic technologies. In this review, we discuss the latest developments in translational technologies involving characterization methods including the facts in their support and the challenges they face.

  16. Bacterial binding to extracellular proteins - in vitro adhesion

    DEFF Research Database (Denmark)

    Schou, C.; Fiehn, N.-E.

    1999-01-01

    Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis......Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis...

  17. Concentração de progesterona e de estradiol 17-beta e características ultra-sonográficas da vesícula embrionária no início da gestação em éguas Puro Sangue Inglês Progesterone and estradiol 17-beta concentration, and ultrasonic images of the embryonic vesicle during the early pregnancy in Thoroughbred mares

    Directory of Open Access Journals (Sweden)

    L.E.S. Ferraz

    2001-08-01

    Full Text Available Associaram-se dosagens séricas de progesterona e estradiol 17-beta, realizadas durante os primeiros 36 dias de prenhez em 30 éguas PSI, com exames ultra-sonográficos, para verificar fenômenos que ocorrem com a vesícula embrionária. As éguas foram divididas em dois grupos de 15 animais, o primeiro constituído por éguas paridas e o segundo por éguas virgens ou vazias na estação anterior. Por meio da ultra-sonografia foram verificados fenômenos de mobilidade, fixação e orientação da vesícula embrionária. As concentrações séricas de progesterona e estradiol 17-B variaram (PMeasurements of progesterone and estradiol 17-beta concentrations within the first 36 days of pregnancy were taken in order to study the relationship between their concentrations and the ultrasound embryonic vesicle examination in 30 Thoroughbred mares. Two groups of 15 animals each were used, one consisting of maiden or barren mares from the previous breeding season, and the other one of foaling mares. The phenomena of mobility, fixation and orientation of the embryonic vesicle were studied, and no relationship between hormone concentration and the development of the concept was found. The concentration of oestrogens was higher (P<0.01 in the foaling mares.

  18. Acute extracellular ethanol load does not produce hyponatremia by internal osmoregulation

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, J.E.; Tzamaloukas, A.H.; Long, D.A.

    1986-03-05

    Hyponatremia is frequently present in subjects intoxicated with ethanol. To study whether an acute increase in extracellular osmolality by addition of ethanol creates any clinically appreciable osmotic shift of intracellular water extracellularly, they infused over 20 sec 11 mmol/kg of ethanol intravenously into 5 anesthetized dogs (2 with intact renal function, 3 anuric) and measured plasma sodium and ethanol concentrations and osmolality at frequent intervals for 100 min after the end of the infusion. For a range of ethanol concentration between 4 and 120 mmol/l, changes in osmolality were equal to ethanol concentration in plasma water (y = -0.49 + 1.06 x mosm/kg per mmol/l, r = 0.981, p < 0.01). Plasma sodium concentration remained unchanged from baseline throughout the experiments, even at 1 min post-infusion, when osmolality was 78 +/- 25 mosm/kg above the baseline. An acute increase in extracellular osmolality created by rapid intravenous infusion of a large dose of ethanol does not create any osmotic shift of intracellular water extracellularly, that can be detected by dilution of extracellular sodium. The mechanism of hyponatremia in ethanol intoxication is not internal osmoregulation, but abnormalities in external balance of body water and/or solute.

  19. Cryptic chemotactic activity of fibronectin for human monocytes resides in the 120-kDa fibroblastic cell-binding fragment.

    Science.gov (United States)

    Clark, R A; Wikner, N E; Doherty, D E; Norris, D A

    1988-08-25

    Monocytes and lymphocytes form a second wave of infiltrating blood leukocytes in areas of tissue injury. The mechanisms for monocyte accumulation at these sites are not completely understood. Recently, however, fragments from extracellular matrix proteins including collagen, elastin, and fibronectin have been shown to induce monocyte chemotaxis. In this report we demonstrate that chemotactic activity for human monocytes is expressed when a 120-kDa fragment containing the RGDS cell-binding peptide is released from intact fibronectin or from larger fibronectin fragments. Monocytes, either from mononuclear cell Ficoll-Hypaque preparations (10-20% monocytes, 89-90% lymphocytes) or from elutriation preparations (95% monocytes, 5% lymphocytes), but not lymphocytes, migrated toward 120-kDa fragment preparations (10(-7) M) in blind-end chambers when the cells were separated from the chemoattractant by a 5-micron pore polycarbonate filter either alone or overlying a 0.45-micron pore nitrocellulose filter. Neutrophils migrated toward zymosan-activated serum but not toward 10(-5)-10(-8) M concentrations of the 120-kDa fragment. Intact fibronectin had no chemotactic activity for human monocytes. Fibronectin was isolated from citrated human plasma by sequential gelatin-Sepharose affinity and DEAE ion-exchange chromatography in the presence of buffers containing 1 mM phenylmethylsulfonyl fluoride to prevent fragmentation. Controlled enzymatic digestion with thermolysin cleaved fibronectin into 30 kDa fibrin, 45 kDa collagen, and 150/160-kDa cell and heparin domains. Upon prolonged digestion, purified 150/160-kDa fragments were cleaved into 120-kDa cell and 30/40-kDa heparin-binding fragments. Even though the intact fibronectin molecule, the 150/160-kDa fragments, and the 120-kDa fragment, have cell binding activity for Chinese hamster ovary fibroblasts, only the 120-kDa fragment expressed chemotactic activity for human monocytes. Thus, the 120-kDa fibroblastic cell

  20. The extracellular RNA complement of Escherichia coli.

    Science.gov (United States)

    Ghosal, Anubrata; Upadhyaya, Bimal Babu; Fritz, Joëlle V; Heintz-Buschart, Anna; Desai, Mahesh S; Yusuf, Dilmurat; Huang, David; Baumuratov, Aidos; Wang, Kai; Galas, David; Wilmes, Paul

    2015-01-21

    The secretion of biomolecules into the extracellular milieu is a common and well-conserved phenomenon in biology. In bacteria, secreted biomolecules are not only involved in intra-species communication but they also play roles in inter-kingdom exchanges and pathogenicity. To date, released products, such as small molecules, DNA, peptides, and proteins, have been well studied in bacteria. However, the bacterial extracellular RNA complement has so far not been comprehensively characterized. Here, we have analyzed, using a combination of physical characterization and high-throughput sequencing, the extracellular RNA complement of both outer membrane vesicle (OMV)-associated and OMV-free RNA of the enteric Gram-negative model bacterium Escherichia coli K-12 substrain MG1655 and have compared it to its intracellular RNA complement. Our results demonstrate that a large part of the extracellular RNA complement is in the size range between 15 and 40 nucleotides and is derived from specific intracellular RNAs. Furthermore, RNA is associated with OMVs and the relative abundances of RNA biotypes in the intracellular, OMV and OMV-free fractions are distinct. Apart from rRNA fragments, a significant portion of the extracellular RNA complement is composed of specific cleavage products of functionally important structural noncoding RNAs, including tRNAs, 4.5S RNA, 6S RNA, and tmRNA. In addition, the extracellular RNA pool includes RNA biotypes from cryptic prophages, intergenic, and coding regions, of which some are so far uncharacterised, for example, transcripts mapping to the fimA-fimL and ves-spy intergenic regions. Our study provides the first detailed characterization of the extracellular RNA complement of the enteric model bacterium E. coli. Analogous to findings in eukaryotes, our results suggest the selective export of specific RNA biotypes by E. coli, which in turn indicates a potential role for extracellular bacterial RNAs in intercellular communication. © 2015 The

  1. Exposure to repeated immobilization stress inhibits cocaine-induced increase in dopamine extracellular levels in the rat ventral tegmental area.

    Science.gov (United States)

    Sotomayor-Zárate, Ramón; Abarca, Jorge; Araya, Katherine A; Renard, Georgina M; Andrés, María E; Gysling, Katia

    2015-11-01

    A higher vulnerability to drug abuse has been observed in human studies of individuals exposed to chronic or persistent stress, as well as in animal models of drug abuse. Here, we explored the effect of repeated immobilization stress on cocaine-induced increase in dopamine extracellular levels in VTA and its regulation by corticotropin-releasing factor (CRF) and GABA systems. Cocaine (10mg/Kg i.p.) induced an increase of VTA DA extracellular levels in control rats. However, this effect was not observed in repeated stress rats. Considering the evidence relating stress with CRF, we decided to perfuse CRF and CP-154526 (selective antagonist of CRF1 receptor) in the VTA of control and repeated stress rats, respectively. We observed that perfusion of 20μM CRF inhibited the increase of VTA DA extracellular levels induced by cocaine in control rats. Interestingly, we observed that in the presence of 10μM CP-154526, cocaine induced a significant increase of VTA DA extracellular levels in repeated stress rats. Regarding the role of VTA GABA neurotransmission, cocaine administration induced a significant increase in VTA GABA extracellular levels only in repeated stress rats. Consistently, cocaine was able to increase VTA DA extracellular levels in repeated stress rats when 100μM bicuculline, an antagonist of GABAA receptor, was perfused intra VTA. Thus, both CRF and GABA systems are involved in the lack of response to cocaine in the VTA of repeated stress rats. It is tempting to suggest that the loss of response in VTA dopaminergic neurons to cocaine, after repeated stress, is due to an interaction between CRF and GABA systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Extracellular Proteins: Novel Key Components of Metal Resistance in Cyanobacteria?

    Science.gov (United States)

    Giner-Lamia, Joaquín; Pereira, Sara B; Bovea-Marco, Miquel; Futschik, Matthias E; Tamagnini, Paula; Oliveira, Paulo

    2016-01-01

    Metals are essential for all living organisms and required for fundamental biochemical processes. However, when in excess, metals can turn into highly-toxic agents able to disrupt cell membranes, alter enzymatic activities, and damage DNA. Metal concentrations are therefore tightly controlled inside cells, particularly in cyanobacteria. Cyanobacteria are ecologically relevant prokaryotes that perform oxygenic photosynthesis and can be found in many different marine and freshwater ecosystems, including environments contaminated with heavy metals. As their photosynthetic machinery imposes high demands for metals, homeostasis of these micronutrients has been widely studied in cyanobacteria. So far, most studies have focused on how cells are capable of controlling their internal metal pools, with a strong bias toward the analysis of intracellular processes. Ultrastructure, modulation of physiology, dynamic changes in transcription and protein levels have been studied, but what takes place in the extracellular environment when cells are exposed to an unbalanced metal availability remains largely unknown. The interest in studying the subset of proteins present in the extracellular space has only recently begun and the identification and functional analysis of the cyanobacterial exoproteomes are just emerging. Remarkably, metal-related proteins such as the copper-chaperone CopM or the iron-binding protein FutA2 have already been identified outside the cell. With this perspective, we aim to raise the awareness that metal-resistance mechanisms are not yet fully known and hope to motivate future studies assessing the role of extracellular proteins on bacterial metal homeostasis, with a special focus on cyanobacteria.

  3. Extracellular Production of Reactive Oxygen Species by Marine Microbiota

    Science.gov (United States)

    Schneider, R. J.; Roe, K. L.; Voelker, B. M.; Hansel, C. M.

    2016-02-01

    The reactive oxygen species (ROS) superoxide (O2-) and hydrogen peroxide (H2O2) are important to the cycling of trace metals and carbon in marine systems. Previous studies have shown that biological ROS production in the ocean may be significant. We examined the ability of five common species of diatoms to produce and break down ROS in the presence and absence of light by suspending cells on filters and measuring downstream ROS concentrations using chemiluminescence probes. Results show a wide range of rates (undetectable to 7.3 x 10-16 mol cell-1 hr-1) and suggest that extracellular ROS production occurs through a variety of pathways. H2O2 decay appears to be mediated primarily by active cell processes, while O2- appears to occur through a combination of active and passive cell processes. Extracellular H2O2 production and decay were also determined for twelve species of heterotrophic bacteria using two different methodologies. Measured decay rates were consistent despite methodological differences. By contrast, large variability of production rates was observed could vary significantly even among between replicates of the same species measured using the same methodology. Although production rates cannot be stated with certainty, it is likely that extracellular H2O2 production occurs in most bacterial species.

  4. Características quantitativas da carcaça de cordeiros deslanados Morada Nova em função da relação volumoso:concentrado na dieta Quantitative characteristics of the carcass of Morada Nova lambs fed different dietary ratios of forage and concentrate

    Directory of Open Access Journals (Sweden)

    Severino Gonzaga Neto

    2006-08-01

    Full Text Available Com o objetivo de avaliar a influência da relação volumoso:concentrado sobre a composição tecidual e os rendimentos de carcaça e de cortes comerciais de cordeiros Morada Nova em confinamento, utilizaram-se 18 cordeiros com peso vivo (PV inicial de 15 kg, distribuídos em seis grupos de três animais (um em cada dieta, de acordo com a relação volumoso(V:concentrado(C: 40:60, 55:45 e 70:30. Foram avaliados os pesos de corpo vazio (PCV, de carcaça quente (PCQ e de carcaça fria (PCF, a partir dos quais foram calculados os rendimentos biológico (RB, de carcaça quente (RCQ e de carcaça fria (RCF e a perda de peso por resfriamento (PPR. A carcaça foi dividida em cinco cortes cárneos (perna, lombo, costelas, paleta e pescoço, os quais foram pesados para cálculo de seus rendimentos em relação ao peso da meia-carcaça. A perna foi dissecada em músculo, osso e gordura e os pesos desses tecidos foram expressos em peso absoluto e em porcentagem da perna. Calcularam-se as relações músculo:osso e músculo:gordura, o índice de musculosidade da perna (IMP e a área de olho-de-lombo (AOL. O aumento de 30 para 60% de concentrado na dieta elevou os rendimentos de carcaça quente e carcaça fria, assim como o rendimento biológico. Os crescentes teores de concentrado na dieta não afetaram a porcentagem de músculo na perna, mas proporcionaram maior deposição de gordura e maior área de olho-de-lombo.Eighteen lambs averaging initial body weight (BW of 15 kg were allotted to six groups of three animals (one lamb per diet and were fed diets with following forage:concentrate ratios (F:C: 1 40F:60C; 2 55F:45C; or 3 70F:30C. Lambs of each group were slaughtered when the animal fed the diet with the highest concentrate level reached 25 kg of BW. Animals were slaughtered after 16 h of fasting (feed and water. After obtaining the slaughter body weight (SBW, animals were anesthetized by electric discharge and killed by bleeding of the carotid

  5. Isolation, purification and characterization of extracellular protease produced by marine-derived endophytic fungus Xylaria psidii KT30

    Institute of Scientific and Technical Information of China (English)

    Bugi Ratno Budiarto; Apon Zaenal Mustopa; Kustiariyah Tarman

    2015-01-01

    Objective:To isolate, purify and characterize extracellular protease produced by Xylaria psidii (X. psidii) KT30. Methods:In the present study, the extracellular protease secreted by X. psidii KT30 was isolated and purified by using three steps of protein purification, then the purified protease was characterized by applying qualitative and quantitative enzymatic assays. Results:Extracellular protease with molecular mass 71 kDa has been purified successfully by applying diethylaminoethanol-Sepharose followed by sephadex SG75 with its final specific protease activity of 0.091 IU/mg. Protease was the most active at temperature 60 °C and pH 7. The activity of enzyme was abolished mostly by phenylmethanesulfonyl fluoride, showing it is family of serine protease. Conclusions:Extracellular serine protease produced by X. psidii KT30 with good biochemical properties displayed some promising results for its further application in field of biotechnology or medicine.

  6. Isolation, purification and characterization of extracellular protease produced by marine-derived endophytic fungus Xylaria psidii KT30

    Directory of Open Access Journals (Sweden)

    Bugi Ratno Budiarto

    2015-01-01

    Full Text Available Objective: To isolate, purify and characterize extracellular protease produced by Xylaria psidii (X. psidii KT30. Methods: In the present study, the extracellular protease secreted by X. psidii KT30 was isolated and purified by using three steps of protein purification, then the purified protease was characterized by applying qualitative and quantitative enzymatic assays. Results: Extracellular protease with molecular mass 71 kDa has been purified successfully by applying diethylaminoethanol-Sepharose followed by sephadex SG75 with its final specific protease activity of 0.091 IU/mg. Protease was the most active at temperature 60 °C and pH 7. The activity of enzyme was abolished mostly by phenylmethanesulfonyl fluoride, showing it is family of serine protease. Conclusions: Extracellular serine protease produced by X. psidii KT30 with good biochemical properties displayed some promising results for its further application in field of biotechnology or medicine.

  7. Transcriptome of extracellular vesicles released by hepatocytes.

    Directory of Open Access Journals (Sweden)

    Felix Royo

    Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

  8. Extracellular potassium inhibits Kv7.1 potassium channels by stabilizing an inactivated state

    DEFF Research Database (Denmark)

    Larsen, Anders Peter; Steffensen, Annette Buur; Grunnet, Morten;

    2011-01-01

    Kv7.1 (KCNQ1) channels are regulators of several physiological processes including vasodilatation, repolarization of cardiomyocytes, and control of secretory processes. A number of Kv7.1 pore mutants are sensitive to extracellular potassium. We hypothesized that extracellular potassium also...... modulates wild-type Kv7.1 channels. The Kv7.1 currents were measured in Xenopus laevis oocytes at different concentrations of extracellular potassium (1-50 mM). As extracellular potassium was elevated, Kv7.1 currents were reduced significantly more than expected from theoretical calculations based...... on the Goldman-Hodgkin-Katz flux equation. Potassium inhibited the steady-state current with an IC(50) of 6.0 ± 0.2 mM. Analysis of tail-currents showed that potassium increased the fraction of channels in the inactivated state. Similarly, the recovery from inactivation was slowed by potassium, suggesting...

  9. Extracellular potassium dynamics in the hyperexcitable state of the neuronal ictal activity

    Science.gov (United States)

    Florence, Gerson; Pereira, Tiago; Kurths, Jürgen

    2012-12-01

    An enduring question in epilepsy research concerns with the mechanisms responsible for the neuronal hyperexcitability. This theme is under debate and different hypotheses have been put forward. One hypothesis relates to extracellular ionic variations, especially the increase of the extracellular potassium concentration ([K+]o). During the epileptiform bursting, an increase of [K+]o is observed which raises the cellular excitability. It remains unclear, however, how the extracellular potassium variation could affect the generation and persistence of epileptiform bursting within the ictal phase, that is, during the epileptic seizure. The neuronal mechanisms responsible for this cellular hyperexcitability are not yet fully understood, hindering the development of more efficient therapies to control epilepsy. Mathematical models with biological plausibility have provided considerable insights into the mechanisms underlying epileptiform pattern. This paper reviews experimental evidences and computational studies concerning effects of the extracellular potassium dynamics on the cellular excitability within the neuronal ictal activity.

  10. Agonist-regulated Cleavage of the Extracellular Domain of Parathyroid Hormone Receptor Type 1*

    Science.gov (United States)

    Klenk, Christoph; Schulz, Stefan; Calebiro, Davide; Lohse, Martin J.

    2010-01-01

    The receptor for parathyroid hormone (PTHR) is a main regulator of calcium homeostasis and bone maintenance. As a member of class B of G protein-coupled receptors, it harbors a large extracellular domain, which is required for ligand binding. Here, we demonstrate that the PTHR extracellular domain is cleaved by a protease belonging to the family of extracellular metalloproteinases. We show that the cleavage takes place in a region of the extracellular domain that belongs to an unstructured loop connecting the ligand-binding parts and that the N-terminal 10-kDa fragment is connected to the receptor core by a disulfide bond. Cleaved receptor revealed reduced protein stability compared with noncleaved receptor, suggesting degradation of the whole receptor. In the presence of the agonistic peptides PTH(1–34), PTH(1–14), or PTH(1–31), the processing of the PTHR extracellular domain was inhibited, and receptor protein levels were stabilized. A processed form of the PTHR was also detected in human kidney. These findings suggest a new model of PTHR processing and regulation of its stability. PMID:20080964

  11. Agonist-regulated cleavage of the extracellular domain of parathyroid hormone receptor type 1.

    Science.gov (United States)

    Klenk, Christoph; Schulz, Stefan; Calebiro, Davide; Lohse, Martin J

    2010-03-19

    The receptor for parathyroid hormone (PTHR) is a main regulator of calcium homeostasis and bone maintenance. As a member of class B of G protein-coupled receptors, it harbors a large extracellular domain, which is required for ligand binding. Here, we demonstrate that the PTHR extracellular domain is cleaved by a protease belonging to the family of extracellular metalloproteinases. We show that the cleavage takes place in a region of the extracellular domain that belongs to an unstructured loop connecting the ligand-binding parts and that the N-terminal 10-kDa fragment is connected to the receptor core by a disulfide bond. Cleaved receptor revealed reduced protein stability compared with noncleaved receptor, suggesting degradation of the whole receptor. In the presence of the agonistic peptides PTH(1-34), PTH(1-14), or PTH(1-31), the processing of the PTHR extracellular domain was inhibited, and receptor protein levels were stabilized. A processed form of the PTHR was also detected in human kidney. These findings suggest a new model of PTHR processing and regulation of its stability.

  12. Production and characterization of an extracellular polysaccharide of antarctic marine bacteria Pseudoalteromonas sp. S-15-13

    Institute of Scientific and Technical Information of China (English)

    LI Jiang; CHEN Kaoshan; LIN Xuezheng; HE Peiqing; LI Guangyou

    2006-01-01

    Twenty-seven antarctic bacteria producing extracellular polysaccharide (EPS) were selected from 57 strains by staining technology. The effects of major environmental factors on the growth and EPS production of Pseudoalteromonas sp. S-15-13 were investigated, and the EPS was separated and purified for characterization analysis. The results showed that the optimal conditions for the EPS production were culture period, 56 h; growth temperature, 8 ℃; carbon source, 1.0% glucose; NaCl concentration, 3.0%; pH 6.0~7.0. The EPS was purified by cold ethanol precipitation, proteins removal, ion exchange chromatography and gel chromatography technology. The molecular mass of EPS-II was 62 kDa as determined by the high performance gel permeation chromatography. Its sugar composition was a homopolymer of mannose analyzed by gas chromatograph spectroscopy. After repeated freezing and thawing of the bacteria biomass in the presence of EPS, the bacterial growth was much higher than that observed after freezing in the absence of EPS and the difference augmented with the increase of freeze-thaw cycles. It is hypothesized that the adaptation of Pseudoalteromonas sp. S-15-13 to the antarctic marine conditions, characterized by low temperature, high NaCl concentration and repeated freeze-thaw cycles, might be related to the EPS production ability.

  13. Role of extracellular exopolymers on biological phosphorus removal

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-nan; XUE Gang; YU Shui-li; ZHAO Fang-bo

    2006-01-01

    Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.

  14. In Vivo Analysis of Extracellular Proteins in Rat Brains with a Newly Developed Intracerebral Microdialysis Probe

    Directory of Open Access Journals (Sweden)

    Nakamura,Mitsuo

    1990-02-01

    Full Text Available Peptides and proteins in the extracellular space in the central nervous system were investigated in vivo using an intracerebral microdialysis probe. The molecular cut-off of the hollow fiber which was used for the probe was approximately 100 kDa. We examined recovery rates of several compounds in vitro. The recovery rates of proteins and peptides were between 7-28%, with the exceptions of substance P and insulin-like growth factor I. The recovery rates of monoamines and their metabolites were 22-40%. In in vivo studies, two major proteins with apparent molecular weights of 62 kDa and 12 kDa, and several minor proteins (28 kDa, 43 kDa, 52 kDa and 70 kDa were detected by SDS-polyacrylamide gel electrophoresis in the dialysate from a probe implanted in the striatum of anesthetized rats. These results suggest that the newly developed, intracerebral microdialysis probe might be useful for investigating the dynamic changes of peptides and proteins in the central nervous system.

  15. Desempenho e características da carcaça de tourinhos Santa Gertrudes confinados, recebendo dietas com alto concentrado e níveis crescentes de polpa cítrica peletizada Feedlot performance and carcass characteristics of Santa Gertrudis bulls, fed high concentrate diets with increasing levels of dehydrated citrus pulp pellets

    Directory of Open Access Journals (Sweden)

    Wignez Henrique

    2004-04-01

    Full Text Available O experimento foi desenvolvido com o objetivo de avaliar o efeito da substituição do milho pela polpa cítrica peletizada sobre o desempenho e as características da carcaça de tourinhos Santa Gertrudes confinados. Vinte e oito animais, com nove meses de idade e peso inicial de 277 kg, foram confinados em baias individuais. O período experimental foi de 92 dias, após 21 dias de adaptação. Os animais receberam dietas contendo 20% da matéria seca como silagem de milho, com 40% de grãos. Foram testados os níveis de 0, 25, 40 e 55% de participação da polpa cítrica peletizada na matéria seca da dieta. Não houve efeito do nível de polpa cítrica na dieta sobre ganho de peso, ingestão diária de matéria seca, eficiência alimentar, rendimento de carcaça, área de olho de lombo e peso da gordura renal-pélvica-inguinal. Os pesos do fígado e da carcaça foram significativamente maiores com o aumento da polpa cítrica na dieta, que também determinou decréscimo linear na espessura de gordura sobre a 12ª costela. O pH das fezes foi semelhante entre os níveis de participação da polpa cítrica. Não foi verificada a ocorrência de abscessos no fígado em nenhum tratamento, apesar da dieta conter alto teor de concentrado. A polpa cítrica peletizada pode compor até 55% da matéria seca de dietas, substituindo o milho em grão, para tourinhos em terminação recebendo altos níveis de concentrado, apenas com diminuição da espessura de gordura.The experiment was developed to evaluate the effect of the replacement of corn grain by dehydrated citrus pulp pellets on the performance and carcass characteristics of Santa Gertrudis young bulls fed high concentrate diets. Twenty-eight bulls, with average age of nine months and an initial weight of 277 kg, were kept in individual pens and fed during 92 days, after 21 days of adaptation. The animals were fed a diet with 20% of the dry matter as corn silage, with 40% of grain. Treatments

  16. Water repellency of sandy soil as a function of hydrophobic concentration Influência da concentração de extratos hidrofóbicos na repelência à água em solos arenosos

    Directory of Open Access Journals (Sweden)

    Yorleni Chang Cambronero

    2011-03-01

    Full Text Available

    Soil water repellency has been reported worldwide being most extremes cases observed in sandy soils. Soil  water repellency is accepted to be caused by recovering  of soil particles by hydrophobic compounds originated  from plant decomposition. This work aimed to evaluate  the influence of concentration of hydrophobic extracts  from a forest soil under Pinus taeda on water repellency  of sandy soil with different organic matter  content. Hydrophobic compounds were extracted from a  everely hydrophobic Lithosol, using  chloroform:acetone, followed by isopropanol:ammonia. The water drops penetration time test (WDPT was applied in dried samples under four temperatures, seven treatments (sand with 0%; 3%; 6.5%; 6.5% + 10% of humic acid (AH; 6,5% + 30% of AH; 6.5% + 50% of AH; and 10% of charcoal as organic matter, and three levels of hydrophobic extract. The extracted material induced hydrophobicity in all treatments, in variable intensity, but lower than those found in the original Lithosol. Treatments with extract level 1 (2.88 g kg-1 presented the highest times of water repellency.

    doi: 10.4336/2011.pfb.31.65.01

    A repelência à água é estudada em vários solos do  mundo, sendo os casos mais extremos encontrados  em solos arenosos. Acredita-se que a repelência à  água seja causada pelo recobrimento das partículas do  solo por compostos hidrofóbicos derivados da  decomposição de plantas. Este trabalho avaliou a  influência da concentração de extratos hidrofóbicos de  um Neossolo sob plantio de Pinus taeda, na repelência  à água em amostras de um solo arenoso preparado  em laboratório, com diferentes teores de matéria  orgânica. Os extratos hidrofóbicos do solo original foram extraídos com clorofórmio:acetona, seguido de   isopropanol:amônia. Os tratamentos constaram de  mistura de areia com sete níveis de matéria orgânica  (0%; 3%; 6,5%; 6,5% + 10% de ácido húmico (AH;  6

  17. Decrease of extracellular taurine in the rat dorsal hippocampus after central nervous administration of vasopressin

    DEFF Research Database (Denmark)

    Brust, P; Christensen, Thomas; Diemer, Nils Henrik

    1992-01-01

    The extracellular amino acid concentrations in the left and right dorsal hippocampus of male rats were studied before and during application of vasopressin into the right hippocampus. The method of intracerebral microdialysis was used for both arginine vasopressin administration and monitoring...... of the composition of the extracellular fluid. The concentrations of 16 amino acids were measured by HPLC in the perfusate samples. The level of taurine declined 20% in the right hippocampus during perfusion with vasopressin, whereas o-phosphoethanolamine decreased in both sides, the left 20% and the right 24...

  18. Efeito da raça, dieta, época e ordem de parição na concentração de imunoglobulina G no colostro de suínos Effect of breed, diet, period and lactation numbers on immunoglobulin G concentration in swine colostrum

    Directory of Open Access Journals (Sweden)

    Raul Machado Neto

    2001-10-01

    Full Text Available Este trabalho teve por objetivo estudar os efeitos da raça, dieta, época do ano e ordem de parição na concentração de imunoglobulina G (IgG no colostro de porcas. A concentração de IgG foi determinada no colostro de 60 porcas, 33 da raça Large White e 27 da raça Landrace, submetidas a dietas contendo 0%, 7%, 14% e 21% de levedura seca (LS. A levedura seca de destilaria de álcool de cana-de-açúcar (Saccharomyces cerevisiae substituiu parte do milho e do farelo de soja da ração mantendo o nível de 14% de proteína bruta. Não foi verificado efeito significativo (P>0,05 de raça e da dieta sobre a concentração de IgG do colostro. Os valores mais elevados de IgG foram observados no colostro de porcas que pariram entre maio e outubro (PThe objective of the present study was to determine the effects of breed, diet, period of the year and lactation numbers on the concentration of immunoglobulin G (IgG in sows colostrum. IgG concentration was determined in colostrum of 60 sows (33 Large White and 27 Landrace submitted to four different diets with 0%, 7%, 14% and 21% of dried yeast. Dried yeast from alcohol of sugar cane industry (Saccharomyces cerevisiae was used as substitute for corn and soybean mill keeping the level of crude protein at 14%. IgG concentration in the colostrum was not affected by breed and diet. Higher concentration of IgG was found in colostrum of sows farrowing occurred between May and October (P<0.05. Quadratic (P<0.10 and cubic (P<0.01 effects of parturition order on IgG concentration were detected. Females from first parturition had lower concentration (P<0.05 of IgG (49.98±7.9 mg/mL compared to females from second (92.70±5.9 mg/mL, third (70.72±5.6 mg/mL and fourth (85.56±9.0 mg/mL parturition, demonstrating that animals with more immunological experience have higher concentrations of IgG in the colostrum.

  19. Estratégia de fornecimento de concentrado para vacas da raça Holandesa em pastagens de coast-cross Strategy of giving concentrate to lactating Holstein cows grazing coast-cross pasture

    Directory of Open Access Journals (Sweden)

    Maurilio José Alvim

    1999-09-01

    Full Text Available O experimento foi conduzido na Embrapa-Centro Nacional de Pesquisa de Gado de Leite, Coronel Pacheco, MG, objetivando avaliar formas de fornecer 6 kg de concentrado para vacas em pastagem de coast-cross: A - quantidade fixa, e B - quantidade variável (9, 6 e 3 kg/vaca/dia, respectivamente na primeira, segunda e terceira fase da lactação. O delineamento foi o de blocos ao acaso e duas repetições de pastagem, com os tratamentos organizados em parcelas divididas. Nas parcelas, consideraram-se os critérios de distribuição de ração, e nas subparcelas, as fases de lactação. O fornecimento variável de concentrado favoreceu (P 0,05, 93,1 (±10,8 e 94,8 (±10,9 kg/ha (P > 0,05 na segunda; 14,2 (±2,2 e 13,4 (±2,3 kg/vaca (P > 0,05 e 102,2 (±12,4 e 93,8 (±10,5 kg/ha (P > 0,05 na terceira, respectivamente em relação a A e B. A dose variável mostrou ser a mais indicada para suplementar vacas Holandesas em pastagem coast-cross.The trial was carried out at the Embrapa-Centro Nacional de Pesquisa de Gado de Leite, at Coronel Pacheco, Brazil, to evaluate two ways of feeding 6 kg/day of a concentrate mixture to cows grazing a coast-cross pasture: A - a fixed amount, and B - a variable amount (9, 6 and 3 kg/cow/day for the first, second, and third stage of lactation. A randomized block design was used with two replications for land grazing area, with the treatments organized in split plots. In the plots, the ways of feeding of distributing the ration concentrate were considered, and in the split plots, the phases of lactation were used. Feeding variable amount of concentrate affected (P 0.05, 93.1 (±10.8 and 94.8 (±10.9 kg/ha (P > 0.05 in the second phase; 14.2 (±2.2 and 13.4 (±2.3 kg/cow (P > 005 and 102.2 (±12.4 and 93.8 (±10.5 kg/ha (P > 0.05 in the last phase, respectively for A and B. The variable dose was the best indicated to supplement Holstein dairy cows in coast-cross pasture.

  20. Effect of the inherent variation in the mineral concentration of alfalfa cultivars on aphid populations Efeito da variação inata da concentração de minerais em cultivares de alfafa (Medicago sativa em população de afídeos (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Alexandre de Almeida e Silva

    2005-01-01

    Full Text Available Plants have inherent variability of mineral content which affects their physiology and consequently the herbivorous insects feeding on them. Besides, insects need considerable amounts of potassium, phosphorus and magnesium in their diets, whereas little calcium, sodium and chloride are required. In this study, the inherent variation on mineral (Ca, S, Mg, N, P, K and also C:N ratio concentrations and aphid (Acyrthosiphon spp., Therioaphis maculata, Aphis craccivora populations on three alfalfa (Medicago sativa cultivars (P3; Crioula, the most widely cultivated in Brazil, and CUF 101, an aphid-resistant were studied between September/1997 and August/1998. A significant variation on mineral concentrations and aphid populations was observed among different sampling times and cultivars. The correlations between C:N ratio, Mg, N, P and S concentrations and aphid density variation suggest that the mineral status affects aphid population dynamics under field conditions.As plantas têm variação inata do conteúdo de minerais e seu estado nutricional afeta sua fisiologia cloretos. A variação inata na concentração de minerais (Ca, S, Mg, N, P, K e também a razão C:N e na população de afídeos (Acyrthosiphon spp., Therioaphis maculata, Aphis craccivora em três cultivares de alfafa (M. sativa - P3; Crioula, as mais cultivadas no Brasil, e CUF 101, resistente a afídeos - foi estudada entre setembro/1997 a agosto/1998 neste trabalho. A concentração de minerais e as populações de pulgões variaram significativamente entre os diferentes períodos de coleta e cultivares. As correlações encontradas entre as concentrações de Mg, N, P, S e a razão C:N e a variação no número de pulgões sugerem que os minerais da planta afetam a dinâmica populacional dos pulgões em campo.

  1. Qualidade da água para consumo humano e concentração de fluoreto Calidad del agua para consumo humano y concentración de fluoruro Drinking water quality and fluoride concentration

    Directory of Open Access Journals (Sweden)

    Paulo Frazão

    2011-10-01

    Full Text Available O artigo visa analisar a concentração de fluoreto na água para consumo humano, considerando o balanço entre benefícios e riscos à saúde, e produzir subsídios para atualização da legislação brasileira. Estudos de revisão sistemática, documentos oficiais e dados meteorológicos foram examinados. As temperaturas nas capitais brasileiras indicam que o fluoreto deveria variar de 0,6 a 0,9 mg/L para prevenir cárie dentária. Concentração de fluoreto natural de 1,5 mg/L é tolerável para consumo no Brasil se não houver tecnologia de custo-benefício aceitável para ajuste/remoção do seu excesso. A ingestão diária de água com fluoreto em concentração > 0,9 mg/L representa risco à dentição em menores de oito anos de idade e os consumidores deveriam ser expressamente informados desse risco. Considerando a expansão do programa nacional de fluoretação da água para regiões de clima tipicamente tropical, deve-se revisar a Portaria 635/75, relacionada ao fluoreto adicionado às águas de abastecimento público.El artículo busca analizar la concentración de fluoruro en el agua para consumo humano considerando el balance entre beneficios y riesgos a la salud y producir subsidios para actualización de la legislación brasileña. Estudios de revisión sistemática, documentos oficiales y datos meteorológicos fueron examinados. Las temperaturas en las capitales brasileñas indican que el fluoruro debería variar de 0,6 a 0,9 mg/L para prevenir caries dentaria. Concentración de fluoruro natural de 1,5 mg/L es tolerable para consumo en Brasil si no hay tecnología de costo-beneficio aceptable para ajuste/remoción de su exceso. La ingestión diaria de agua con fluoruro en concentración > 0,9mg/L representa riesgo para la dentición en menores de ocho años de edad y los consumidores deberían ser expresamente informados de este riesgo. Considerando la expansión del programa nacional de fluorificación del agua para regiones de

  2. Processamento visual da forma em humanos: curvas de limiar de contraste para padrões circularmente simétricos Visual processing of form in human: threshold contrast curves to concentrically symmetric patterns

    Directory of Open Access Journals (Sweden)

    Natanael Antonio dos Santos

    2004-01-01

    Full Text Available O objetivo deste trabalho foi mensurar curvas de limiar de contraste para padrões espaciais circularmente simétricos em coordenadas polares. Mensurou-se os limiares de contraste para grade senoidais, freqüências radiais e freqüências radiais acopladas à freqüência angular de 4 ciclos360º. Participaram dos experimentos 6 adultos jovens com acuidade visual normal ou corrigida. As freqüências estimadas com o paradigma psicofísico da escolha forçada foram: 0,2; 0,3; 0,5; 0,8; 1; 2; 3; 4; 6 e 9 cpg. Os resultados mostraram que o acoplamento de freqüências radiais à freqüência angular causou um aumento na sensibilidade do sistema visual humano de pelo menos 1,6 em relação à curva de sensibilidade ao contraste para estímulos radiais puros. Estes resultados são consistentes com o modelo de canais múltiplos de freqüências espaciais para estímulos definido a priori em termos de coordenas polares.The aim of this work was to measure contrast sensitivity curves to concentrically symmetric patterns in a system of polar coordinates. We measured the contrast thresholds to sine wave gratings, radial frequencies and coupled radial/angular frequencies. Six young adults with corrected-to-normal visual acuity participated in the experiments. The frequencies measured with a forced-choice psychophysical method were 0.2, 0.3, 0.5, 0.8, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 and 9.0 cpd. Results showed that coupled radial/angular frequencies caused an increase in the sensitivity of at least 1.6 times in relation to radial contrast sensitivity function. These results were in agreement with the model of multiple channels processing of spatial frequencies of stimuli defined in terms of polar coordinates.

  3. Vertebrate extracellular preovulatory and postovulatory egg coats.

    Science.gov (United States)

    Menkhorst, Ellen; Selwood, Lynne

    2008-11-01

    Extracellular egg coats deposited by maternal or embryonic tissues surround all vertebrate conceptuses during early development. In oviparous species, the time of hatching from extracellular coats can be considered equivalent to the time of birth in viviparous species. Extracellular coats must be lost during gestation for implantation and placentation to occur in some viviparous species. In the most recent classification of vertebrate extracellular coats, Boyd and Hamilton (Cleavage, early development and implantation of the egg. In: Parkes AS (ed.), Marshall's Physiology of Reproduction, vol. 2, 3rd ed. London: Longmans, Green & Co; 1961:1-126) defined the coat synthesized by the oocyte during oogenesis as primary and the coat deposited by follicle cells surrounding the oocyte as secondary. Tertiary egg coats are those synthesized and deposited around the primary or secondary coat by the maternal reproductive tract. This classification is difficult to reconcile with recent data collected using modern molecular biological techniques that can accurately establish the site of coat precursor synthesis and secretion. We propose that a modification to the classification by Boyd and Hamilton is required. Vertebrate egg coats should be classed as belonging to the following two broad groups: the preovulatory coat, which is deposited during oogenesis by the oocyte or follicle cells, and the postovulatory coats, which are deposited after fertilization by the reproductive tract or conceptus. This review discusses the origin and classification of vertebrate extracellular preovulatory and postovulatory coats and illustrates what is known about coat homology between the vertebrate groups.

  4. The roles of serine protease, intracellular and extracellular phenoloxidase in activation of prophenoloxidase system, and characterization of phenoloxidase from shrimp haemocytes induced by lipopolysaccharide or dopamine

    Science.gov (United States)

    Xie, Peng; Pan, Luqing; Xu, Wujie; Yue, Feng

    2013-09-01

    We investigated the effects of lipopolysaccharide (LPS) and dopamine (DA) on the activation of the prophenoloxidase (proPO) system of Litopenaeus vannamei. LPS and DA were shown with a negative dose-dependent effect on hyalne cells (HC), semi-granular cells (SGC), large granular cells (LGC), and total haemocyte count (THC). When haemocytes were treated with LPS or DA, serine proteinase activity and intracellular phenoloxidase (PO) activity were significantly reduced, but extracellular PO activity increased significantly. These findings indicated that the reduction in haemocyte counts was mainly because of the degranulation and activation of the proPO system from semi-granule and large granule cells. The PKC inhibitor, chelerythrine, and the TPK inhibitor, genistein, had an inhibitory effect on extracellular PO activity, while serine proteinase and intracellular PO activity increased. This suggests that the LPS and DA induce the activation of proPO in haemocytes via PKC and TPK-related signaling pathways, but serine proteinase may be activated only by PKC, as the genistein effects were not statistically significant. Electrophoresis analysis revealed that POs induced by LPS or DA have the same molecular mass and high diphenolase activity. Two PO bands at 526 kDa and 272 kDa were observed in PAGE, while in the haemocyte lysate supernatant (HLS), only a 272-kDa band was observed. This band was resolved after SDS-PAGE under non-reducing and reducing conditions into two groups of POs, 166 kDa and 126 kDa, and 78.1 kDa and 73.6 kDa, respectively, suggesting that PO in L. vannamei is an oligomer, which may have different compositions intra- and extracellularly.

  5. Modeling extracellular field potentials and the frequency-filtering properties of extracellular space

    CERN Document Server

    Bedard, C; Destexhe, A; Bédard, Claude; Kroeger, Helmut; Destexhe, Alain

    2003-01-01

    Extracellular local field potentials (LFP) are usually modeled as arising from a set of current sources embedded in a homogeneous extracellular medium. Although this formalism can successfully model several properties of LFPs, it does not account for their frequency-dependent attenuation with distance, a property essential to correctly model extracellular spikes. Here we derive expressions for the extracellular potential that include this frequency-dependent attenuation. We first show that, if the extracellular conductivity is non-homogeneous, there is induction of non-homogeneous charge densities which may result in a low-pass filter. We next derive a simplified model consisting of a punctual (or spherical) current source with spherically-symmetric conductivity/permittivity gradients around the source. We analyze the effect of different radial profiles of conductivity and permittivity on the frequency-filtering behavior of this model. We show that this simple model generally displays low-pass filtering behav...

  6. Minimal inhibitory concentration of azithromycin in Rhodococcus equi strains isolated from foals Concentração inibitória mínima da azitromicina em linhagens de Rhodococcus equi isoladas de potros

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    M.G. Ribeiro

    2006-12-01

    Full Text Available O perfil de sensibilidade microbiana e a concentração inibitória mínima (MIC da azitromicina para 42 cepas de Rhodococcus equi isoladas de potros, no Brasil, e em uma cepa-controle, foi avaliado, respectivamente, pelos métodos de difusão com discos e E-test. A azitromicina apresentou 100% de efetividade in vitro para todas as cepas em ambos os testes. As cepas de R. equi apresentaram MIC90 para azitromicina em valores <1.5µg/ml. Este estudo mostra a alta efetividade da azitromicina em linhagens de R. equi isoladas no Brasil, sugerindo o uso dessa droga como alternativa na terapia da rodococose em potros.

  7. Efeito da concentração e temperatura de adição de trealose em diluentes para a congelação de sêmen ovino em palhetas Effect of the concentration and addition temperature of trehalose in extenders on freezing ram semen in straws

    Directory of Open Access Journals (Sweden)

    Adilson Moura

    1995-01-01

    Full Text Available A trealose é um dissacarídio com potencial emprego como crioprotetor quando adicionada aos meios para congelamento de sêmen ovino. Este experimento foi realizado para verificar os efeitos da temperatura de adição (30°C e 4°C e da concentração de trealose (2%, 4% e 6% sobre o sêmen ovino congelado em palhetas, utilizando como base as formulações INRA e TRIS/FRUTOSE. Os efeitos estudados em ambos experimentos foram medidos através da avaliação da motilidade espermática (MOT e da integridade de acrossomas (INTA em diferentes momentos após o descongelamento (0h, 2h e 5h. Os presentes resultados não recomendam a inclusão da trealose visando incrementar a qualidade in vitro do sêmen ovino congelado em palhetas nas concentrações e diluentes testados, porém, sugerem maiores estudos quanto a sua toxidade e possíveis interações com outros constituintes dos diluentes já formulados para o congelamento de sêmen ovino.This study was aimed to evaluate the possible effects of the addition of trehalose to extenders developed for freezing ram semen in straws. The effects of addition temperature (30°C and 4°C and concentration of trehalose (2, 4 and 6% on INRA and TRIS/FRUTOSE diluents was evaluated. Their effects were studied through motility rate and by acrosome integrity at different incubation times after thawing (0, 2 and 5h. The results do not recommend the inclusion of trehalose in these diluents. However, it would be interesting to learn more about toxicity and interactions between the components of the extenders and trehalose in ram sperm frozen in straws.

  8. Effect of betamethasone and diclofenac sodium on serum and tissue concentration of amoxicillin: in vivo study in rats Efeito da betametasona e do diclofenaco sódico na concentração sérica e tecidual da amoxicilina: estudo in vivo em ratos

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    Thales Rocha Mattos Filho

    2006-10-01

    Full Text Available OBJECTIVE: Antimicrobial agents in combination with anti-inflammatory drugs have been usually prescribed in both Medicine and Dentistry. However, few scientific reports support this clinical practice. The aim of this study was to evaluate the effect of betamethasone and diclofenac sodium on serum and tissue concentration of amoxicillin in rats. METHODS: Four polyurethane sponges were implanted in the back skin of 48 rats. After seven days the animals were divided into 6 groups (n=8. Group 1: amoxicillin (25 mg/kg; G2: diclofenac sodium (2.5 mg/kg; G3: betamethasone (0.1 mg/kg; G4: diclofenac sodium and amoxicillin; G5: betamethasone and amoxicillin; and G6: 0.9% sodium chloride solution (1.0 mL - control group. All drugs were administered in a single dose. After 90 minutes, the granulomatous tissues of each animal were surgically removed and weighed. Blood was collected from cervical plexus, centrifuged and 10µL of serum was placed on paper discs. In order to estimate amoxicillin concentration, serum and granulomatous tissues were separately submitted to microbiological assay, which used 10(8cfu/mL of Staphylococcus aureus ATCC 25923 (penicillin-susceptible strain. After incubation (18 hours, 37ºC the inhibition zones were measured and compared to a regression curve. RESULTS: No inhibition zones were observed for groups 2, 3 and 6. Tissue and serum concentrations of both G1 (4.14µg/g and 2.06µg/mL, respectively and G5 (3.87µg/g and 1.70µg/mL, respectively showed statistically significant differences (Kruskal-Wallis, p0.05. CONCLUSION: Considering single doses, betamethasone did not interfere with amoxicillin levels but diclofenac sodium reduced both tissue and serum levels of amoxicillin in rats.OBJETIVO: A prescrição de antimicrobianos associados a antiinflamatórios é uma prática comum em odontologia, embora na maioria das vezes não haja justificativa para tal conduta. O objetivo deste trabalho foi avaliar, em um estudo in vivo em

  9. Extracellular proteolysis in the adult murine brain.

    Science.gov (United States)

    Sappino, A P; Madani, R; Huarte, J; Belin, D; Kiss, J Z; Wohlwend, A; Vassalli, J D

    1993-08-01

    Plasminogen activators are important mediators of extracellular metabolism. In the nervous system, plasminogen activators are thought to be involved in the remodeling events required for cell migration during development and regeneration. We have now explored the expression of the plasminogen activator/plasmin system in the adult murine central nervous system. Tissue-type plasminogen activator is synthesized by neurons of most brain regions, while prominent tissue-type plasminogen activator-catalyzed proteolysis is restricted to discrete areas, in particular within the hippocampus and hypothalamus. Our observations indicate that tissue-type plasminogen activator-catalyzed proteolysis in neural tissues is not limited to ontogeny, but may also contribute to adult central nervous system physiology, for instance by influencing neuronal plasticity and synaptic reorganization. The identification of an extracellular proteolytic system active in the adult central nervous system may also help gain insights into the pathogeny of neurodegenerative disorders associated with extracellular protein deposition.

  10. The behaviors of Microcystis aeruginosa cells and extracellular microcystins during chitosan flocculation and flocs storage processes.

    Science.gov (United States)

    Pei, Hai-Yan; Ma, Chun-Xia; Hu, Wen-Rong; Sun, Feng

    2014-01-01

    This work aimed to study the effects of chitosan on cell integrity and extracellular microcystins (MCs) of Microcystis aeruginosa cells during flocculation and flocs storage processes. The impacts of chitosan addition, flocculation stirring and flocs storage time were comprehensively detected to prevent or reduce cell lysis and MCs release. Response surface method (RSM) was applied to optimize the chitosan flocculation. Under chitosan concentration 7.31 mg/L and optimized mechanical conditions, 99% of M. aeruginosa cells were integrated removed. Furthermore, amounts of extracellular MCs were adsorbed by chitosan polymers in this process. With chitosan flocs protect, though cells showed some damage, extracellular MCs concentration in flocculated samples lower than background level within first 2 d. However, lots of MCs release was observed after 4d which may result from chitosan degradation and cells lysis. Therefore, chitosan flocs should be treated within 2d to prevent the adsorbed MCs releasing again.

  11. Evaluation of the activity concentration of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb in sediments from Antarctica in the Admiralty bay region; Avaliacao da concentracao de atividade de Ra-226, Ra-228 e Pb-210 em sedimentos provenientes da Antartica na regiao da baia do Almirantado

    Energy Technology Data Exchange (ETDEWEB)

    Mora, Tamires de Araujo

    2015-07-01

    The natural radionuclides from radioactive series of {sup 238}U, {sup 235}U and {sup 232}Th have been applied as tracers in environmental studies for understanding the dynamics that occur in both marine and terrestrial environment, as for example, in research of oceanic processes and management of the coastal region. In the marine environment, these radionuclides can be used to estimate biogeochemical fluxes of marine particles and nutrients that occur in the water column as well as in the sediment. Several research works applied the distribution and the respective disequilibrium degree of natural radionuclides in the environment, including geochronological models for obtaining historical information on samples of certain sediment profile. In this study we performed a radiochemical characterization of the distribution of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb from a sedimentary column called 1B (248 cm long) collected in the Admiralty Bay, Antarctic Peninsula region. The methodology used included the acid leaching of sediment samples followed by the radiochemical sequential separation of {sup 226}Ra and {sup 228}Ra by co-precipitation with Ba(Ra)SO{sub 4} and {sup 210}Pb by co-precipitation with PbCrO{sub 4}. All measurements were carried out by counting of gross alpha and gross beta measures in a low background gas flow proportional detector. The activity concentrations of {sup 226}Ra and {sup 210}Pb were used to estimate the unsupported {sup 210}Pb activities present in sediment profile 1 B. Based on unsupported {sup 210}Pb data and the application of the CIC model (Constant Initial Concentration), it was possible to determine the sedimentation rate of 0.59 ± 0.05 cm /year. (author)

  12. Ratiometric imaging of extracellular pH in bacterial biofilms with C-SNARF-4.

    Science.gov (United States)

    Schlafer, Sebastian; Garcia, Javier E; Greve, Matilde; Raarup, Merete K; Nyvad, Bente; Dige, Irene

    2015-02-01

    pH in the extracellular matrix of bacterial biofilms is of central importance for microbial metabolism. Biofilms possess a complex three-dimensional architecture characterized by chemically different microenvironments in close proximity. For decades, pH measurements in biofilms have been limited to monitoring bulk pH with electrodes. Although pH microelectrodes with a better spatial resolution have been developed, they do not permit the monitoring of horizontal pH gradients in biofilms in real time. Quantitative fluorescence microscopy can overcome these problems, but none of the hitherto employed methods differentiated accurately between extracellular and intracellular microbial pH and visualized extracellular pH in all areas of the biofilms. Here, we developed a method to reliably monitor extracellular biofilm pH microscopically with the ratiometric pH-sensitive dye C-SNARF-4, choosing dental biofilms as an example. Fluorescent emissions of C-SNARF-4 can be used to calculate extracellular pH irrespective of the dye concentration. We showed that at pH values of biofilm and visualized the entire bacterial biomass in in vivo-grown dental biofilms with unknown species composition. We then employed digital image analysis to remove the bacterial biomass from the microscopic images and adequately calculate extracellular pH values. As a proof of concept, we monitored the extracellular pH drop in in vivo-grown dental biofilms fermenting glucose. The combination of pH ratiometry with C-SNARF-4 and digital image analysis allows the accurate monitoring of extracellular pH in bacterial biofilms in three dimensions in real time and represents a significant improvement to previously employed methods of biofilm pH measurement.

  13. Efeito do níquel e da concentração protéica sobre o consumo e digestibilidade aparente da materia seca, proteína bruta, energia e balanço de nitrogênio do feno de Brachiaria brizantha cv. Marandu em ovinos Effect of nickel and protein concentration on consumption and apparent digestibility of dry matter, crude protein, energy, and nitrogen balance of a Brachiaria brizantha cv. Marandu hay, in ovines

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    O.J. De Paula

    2005-09-01

    Full Text Available Avaliaram-se os efeitos do níquel e da concentração protéica da dieta sobre o consumo e a digestibilidade aparente da matéria seca (MS, proteína bruta (PB e energia, e balanço de nitrogênio do feno de Brachiaria brizantha cv. Marandu, oferecido a ovinos. As dietas testadas foram: A- feno; B- feno + níquel; C- feno + mistura protéica; D- feno + níquel + mistura protéica. As dietas continham, respectivamente 0,2, 5,2, 0,5 e 5,5ppm de níquel e 3,1, 3,1, 8,2 e 8,2% de PB. Nos níveis com menor concentração protéica (A e B; 3,1% PB, não foi observado efeito do níquel sobre o consumo e a digestibilidade aparente de matéria seca, energia e proteína, assim como os balanços protéico e energético. Nos com maior concentração protéica (C e D; 8,2% PB, o uso do níquel resultou em menor consumo de MS digestível, energia digestível e energia metabolizável. A maior concentração protéica teve efeito positivo sobre as características avaliadas, independentemente da suplementação ou não com níquel, com exceção da digestibilidade aparente da energia bruta, semelhantes entre as dietas B e D.This study was carried out to evaluate the effect of nickel supplementation and protein concentration of the diet on dry matter intake and apparent digestibilities of dry matter, crude protein (CP and energy, and nitrogen balance of male sheep fed on Brachiaria brizantha cv. marandu hay. The experimental diets were: A- hay; B- hay + nickel; C- hay + protein; D- hay + nickel + protein. The diets contained 0.2, 5.2, 0.5 e 5.5ppm of nickel and 3.1, 3.1, 8.2 and 8.2% of crude protein, respectively. No effect of nickel supplementation on the apparent digestibility of dry matter, energy and protein, as well as the balance of protein and energy were observed for lower protein concentration diets (A and B; 3.1% CP. The nickel supplementation reduced the digestible dry matter, digestible energy and metabolizible energy consumption of higher protein

  14. Optimization of extracellular fungal peroxidase production by 2 Coprinus species.

    Science.gov (United States)

    Ikehata, Keisuke; Pickard, Michael A; Buchanan, Ian D; Smith, Daniel W

    2004-12-01

    Optimum culture conditions for the batch production of extracellular peroxidase by Coprinus cinereus UAMH 4103 and Coprinus sp. UAMH 10067 were explored using 2 statistical experimental designs, including 2-level, 7-factor fractional factorial design and 2-factor central composite design. Of the 7 factors examined in the screening study, the concentrations of carbon (glucose) and nitrogen (peptone or casitone) sources showed significant effects on the peroxidase production by Coprinus sp. UAMH 10067. The optimum glucose and peptone concentrations were determined as 2.7% and 0.8% for Coprinus sp. UAMH 10067, and 2.9% and 1.4% for C. cinereus UAMH 4103, respectively. Under the optimized culture condition the maximum peroxidase activity achieved in this study was 34.5 U x mL(-1) for Coprinus sp. UAMH 10067 and 68.0 U x mL(-1) for C. cinereus UAMH 4103, more than 2-fold higher than the results of previous studies.

  15. Degradabilidade in situ da matéria seca e proteína bruta de concentrados com diferentes fontes energéticas - DOI: 10.4025/actascianimsci.v26i2.1885 In situ dry matter degradability and crude protein of concentrates of different energetic sources - DOI: 10.4025/actascianimsci.v26i2.1885

    Directory of Open Access Journals (Sweden)

    Daniele Cristina da Silva

    2004-04-01

    Full Text Available Foram avaliadas a cinética de degradação e a degradabilidade efetiva (DE da matéria seca (MS e proteína bruta (PB de três concentrados que diferiram na composição da fonte energética: AMI = concentrado rico em amido (56,6% de amido; OLE = concentrado rico em óleo (8,5% de óleo e A+O = concentrado composto pela mistura dos concentrados AMI e OLE (30,72% de amido e 6,05% de óleo. As fontes de amido e óleo utilizadas para comporem os concentrados foram o milho e o caroço de algodão, respectivamente. Foram utilizados três bovinos, machos, inteiros de 352kg de peso vivo e portadores de cânula ruminal. Para taxa de passagem de sólidos de 5%/h, verificou-se que a degradabilidade efetiva (DE da MS foi de 69,17%, 61,15% e 52,99% para os concentrados AMI, A+O e OLE, respectivamente, os quais diferiram (pThe degradation kinetics and the effective degradability (ED of dry matter (DM and crude protein (CP of three concentrates, different in energetic sources composition, were assessed: STA = concentrate of high level of starch (56.6% of starch; OIL = concentrate of high level of oil (8.5% of oil and S+O = concentrate composed of a mixture of STA and OIL (30.72% of starch and 6.05% of oil. The utilized starch and oil to compose the concentrate sources were corn and cottonseed, respectively. Three male bovines, averaging 352kg live weight and fitted with cannulae in the rumen, were used. For the 5%/h solid passage rate, it could be verified that the effective degradability (ED of DM presented 69.17%, 61,15% and 52,99% for STA, S+O and OIL concentrates, respectively, which differed from each other (P<0.01. For the same passage rate, 5%/h, the ED of CP for the STA concentrate (79.42% was different from S+O concentrate (69.41%, but both did not differ from OIL concentrate (73.59%. The S+O concentrate presented intermediate degradation offering more balanced ruminal fermentation conditions.

  16. The extracellular matrix of the lung and its role in edema formation

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    Paolo Pelosi

    2007-06-01

    Full Text Available The extracellular matrix is composed of a three-dimensional fiber mesh filled with different macromolecules such as: collagen (mainly type I and III, elastin, glycosaminoglycans, and proteoglycans. In the lung, the extracellular matrix has several functions which provide: 1 mechanical tensile and compressive strength and elasticity, 2 low mechanical tissue compliance contributing to the maintenance of normal interstitial fluid dynamics, 3 low resistive pathway for an effective gas exchange, d control of cell behavior by the binding of growth factors, chemokines, cytokines and the interaction with cell-surface receptors, and e tissue repair and remodeling. Fragmentation and disorganization of extracellular matrix components comprises the protective role of the extracellular matrix, leading to interstitial and eventually severe lung edema. Thus, once conditions of increased microvascular filtration are established, matrix remodeling proceeds fairly rapidly due to the activation of proteases. Conversely, a massive matrix deposition of collagen fiber decreases interstitial compliance and therefore makes the tissue safety factor stronger. As a result, changes in lung extracellular matrix significantly affect edema formation and distribution in the lung.A matriz extracelular é um aglomerado tridimensional demacromoléculas composta por: fibras colágenas (principalmente, tipos I e III, elastina, glicosaminoglicanos e proteoglicanos. No pulmão, a matriz extracelular tem várias funções, tais como: 1 promover estresse tensil e elasticidade tecidual, 2 contribuir para a manutenção da dinâmica de fluidos no interstício, 3 propiciar efetiva troca gasosa, 4 controlar a função celular através de sua ligação com fatores de crescimento, quimiocinas, citocinas e interação com receptores de superfície, e 5 remodelamento e reparo tecidual. A fragmentação e a desorganização da matriz extracelular pode acarretar edema intersticial e

  17. Efeitos da escarificação química e da concentração de nitrogênio sobre a germinação e o desenvolvimento in vitro de Vanilla planifolia Jack ex Andr. (Orchidaceae: Vanilloideae Effect of chemical scarification and concentration of nitrogen on the germination and in vitro development of Vanilla planifolia Jack ex Andr. (Orchidaceae: Vanilloideae

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    Cristiano Pedroso-de-Moraes

    2012-09-01

    Full Text Available Vanilla planifolia é uma espécie com grande valor comercial, porém sua propagação é dificultada devido à baixa germinação de suas sementes. No presente estudo procurou-se avaliar a influência da escarificação destas sementes por meio da imersão em H2SO4 concentrado durante 60, 120 e 180 segundos, bem como de diferentes concentrações de nitrogênio sobre a germinação e o desenvolvimento das plântulas. Sessenta segundos de escarificação e 25% de nitrogênio no meio de cultura proporcionaram os melhores resultados sobre a germinação e desenvolvimento de V. planifolia, constituindo-se em um procedimento viável para a produção comercial dessa espécie.Vanilla planifolia is a species with a large commercial value; however, it is difficult to propagate due to low seeds germination. In the present study we aimed to evaluate the influence of scarification of the seeds by soaking them in concentrated H2SO4 for 60, 120 and 180 seconds, as well as different concentrations of nitrogen, on germination and plant development. Sixty seconds of scarification and 25% nitrogen in the culture medium provided the best results for germination and is a viable procedure for the commercial production of this species.

  18. Receptor-like activity evoked by extracellular ADP in Arabidopsis root epidermal plasma membrane.

    Science.gov (United States)

    Demidchik, Vadim; Shang, Zhonglin; Shin, Ryoung; Colaço, Renato; Laohavisit, Anuphon; Shabala, Sergey; Davies, Julia M

    2011-07-01

    Extracellular purine nucleotides are implicated in the control of plant development and stress responses. While extracellular ATP is known to activate transcriptional pathways via plasma membrane (PM) NADPH oxidase and calcium channel activation, very little is known about signal transduction by extracellular ADP. Here, extracellular ADP was found to activate net Ca(2+) influx in roots of Arabidopsis (Arabidopsis thaliana) and transiently elevate cytosolic free Ca(2+) in root epidermal protoplasts. An inward Ca(2+)-permeable conductance in root epidermal PM was activated within 1 s of ADP application and repeated application evoked a smaller current. Such response speed and densitization are consistent with operation of equivalents to animal ionotropic purine receptors, although to date no equivalent genes for such receptors have been identified in higher plants. In contrast to ATP, extracellular ADP did not evoke accumulation of intracellular reactive oxygen species. While high concentrations of ATP caused net Ca(2+) efflux from roots, equivalent concentrations of ADP caused net influx. Overall the results point to a discrete ADP signaling pathway, reliant on receptor-like activity at the PM.

  19. Receptor-Like Activity Evoked by Extracellular ADP in Arabidopsis Root Epidermal Plasma Membrane1

    Science.gov (United States)

    Demidchik, Vadim; Shang, Zhonglin; Shin, Ryoung; Colaço, Renato; Laohavisit, Anuphon; Shabala, Sergey; Davies, Julia M.

    2011-01-01

    Extracellular purine nucleotides are implicated in the control of plant development and stress responses. While extracellular ATP is known to activate transcriptional pathways via plasma membrane (PM) NADPH oxidase and calcium channel activation, very little is known about signal transduction by extracellular ADP. Here, extracellular ADP was found to activate net Ca2+ influx in roots of Arabidopsis (Arabidopsis thaliana) and transiently elevate cytosolic free Ca2+ in root epidermal protoplasts. An inward Ca2+-permeable conductance in root epidermal PM was activated within 1 s of ADP application and repeated application evoked a smaller current. Such response speed and densitization are consistent with operation of equivalents to animal ionotropic purine receptors, although to date no equivalent genes for such receptors have been identified in higher plants. In contrast to ATP, extracellular ADP did not evoke accumulation of intracellular reactive oxygen species. While high concentrations of ATP caused net Ca2+ efflux from roots, equivalent concentrations of ADP caused net influx. Overall the results point to a discrete ADP signaling pathway, reliant on receptor-like activity at the PM. PMID:21562328

  20. Extracellular DNA chelates cations and induces antibiotic resistance in Pseudomonas aeruginosa biofilms.

    Directory of Open Access Journals (Sweden)

    Heidi Mulcahy

    2008-11-01

    Full Text Available Biofilms are surface-adhered bacterial communities encased in an extracellular matrix composed of DNA, bacterial polysaccharides and proteins, which are up to 1000-fold more antibiotic resistant than planktonic cultures. To date, extracellular DNA has been shown to function as a structural support to maintain Pseudomonas aeruginosa biofilm architecture. Here we show that DNA is a multifaceted component of P. aeruginosa biofilms. At physiologically relevant concentrations, extracellular DNA has antimicrobial activity, causing cell lysis by chelating cations that stabilize lipopolysaccharide (LPS and the outer membrane (OM. DNA-mediated killing occurred within minutes, as a result of perturbation of both the outer and inner membrane (IM and the release of cytoplasmic contents, including genomic DNA. Sub-inhibitory concentrations of DNA created a cation-limited environment that resulted in induction of the PhoPQ- and PmrAB-regulated cationic antimicrobial peptide resistance operon PA3552-PA3559 in P. aeruginosa. Furthermore, DNA-induced expression of this operon resulted in up to 2560-fold increased resistance to cationic antimicrobial peptides and 640-fold increased resistance to aminoglycosides, but had no effect on beta-lactam and fluoroquinolone resistance. Thus, the presence of extracellular DNA in the biofilm matrix contributes to cation gradients, genomic DNA release and inducible antibiotic resistance. DNA-rich environments, including biofilms and other infection sites like the CF lung, are likely the in vivo environments where extracellular pathogens such as P. aeruginosa encounter cation limitation.

  1. On the chemical dynamics of extracellular polysaccharides in the high Arctic surface microlayer

    Science.gov (United States)

    Gao, Q.; Leck, C.; Rauschenberg, C.; Matrai, P. A.

    2012-07-01

    The surface microlayer (SML) represents a unique system of which the physicochemical characteristics may differ from those of the underlying subsurface seawater (SSW). Within the Arctic pack ice area, the SML has been characterized as enriched in small colloids of biological origin, resulting from extracellular polymeric secretions (EPS). During the Arctic Summer Cloud Ocean Study (ASCOS) in August 2008, particulate organic matter (POM, with size range > 0.22 μm) and dissolved organic matter (DOM, fucose and glucose. The mean concentrations of total hydrolysable neutral sugars in SSW were 94.9 ± 37.5 nM in high molecular weight (HMW) DOM (> 5 kDa) and 64.4 ± 14.5 nM in POM. The enrichment of polysaccharides in the SML appeared to be a common feature, with EFs ranging from 1.7 to 7.0 for particulate polysaccharides and 3.5 to 12.1 for polysaccharides in the HMW DOM fraction. A calculated monosaccharide yield suggests that polymers in the HMW DOM fraction were scavenged, without substantial degradation, into the SML. Bubble scavenging experiments showed that newly aggregated particles could be formed abiotically by coagulation of low molecular weight nanometer-sized gels. Aerosol particles, artificially generated by bubbling experiments, were enriched in polysaccharides by factors of 22-70, relative to the source seawater. We propose that bubble scavenging of surface-active polysaccharides could be one of the possible mechanisms for the enrichment of polysaccharides in the high Arctic open lead SML.

  2. Characteristic of Extracellular Zn(2+) Influx in the Middle-Aged Dentate Gyrus and Its Involvement in Attenuation of LTP.

    Science.gov (United States)

    Takeda, Atsushi; Koike, Yuta; Osaw, Misa; Tamano, Haruna

    2017-03-13

    An increased influx of extracellular Zn(2+) into neurons is a cause of cognitive decline. The influx of extracellular Zn(2+) into dentate granule cells was compared between young and middle-aged rats because of vulnerability of the dentate gyrus to aging. The influx of extracellular Zn(2+) into dentate granule cells was increased in middle-aged rats after injection of AMPA and high K(+) into the dentate gyrus, but not in young rats. Simultaneously, high K(+)-induced attenuation of LTP was observed in middle-aged rats, but not in young rats. The attenuation was rescued by co-injection of CaEDTA, an extracellular Zn(2+) chelator. Intracellular Zn(2+) in dentate granule cells was also increased in middle-aged slices with high K(+), in which the increase in extracellular Zn(2+) was the same as young slices with high K(+), suggesting that ability of extracellular Zn(2+) influx into dentate granule cells is greater in middle-aged rats. Furthermore, extracellular zinc concentration in the hippocampus was increased age-dependently. The present study suggests that the influx of extracellular Zn(2+) into dentate granule cells is more readily increased in middle-aged rats and that its increase is a cause of age-related attenuation of LTP in the dentate gyrus.

  3. RELATIONSHIP BETWEEN ANALGESIA AND EXTRACELLULAR MORPHINE IN BRAIN AND SPINAL-CORD IN AWAKE RATS

    NARCIS (Netherlands)

    MATES, FF; ROLLEMA, H; TAIWO, YO; LEVINE, JD; BASBAUM, AI

    1995-01-01

    Extracellular concentrations of morphine from the dorsal spinal cord, the periaqueductal gray (FAG) including the dorsal raphe, and the lateral hypothalamus were measured by microdialysis in awake rats after intraperitoneal (i.p.) administration of 2.5, 5.0 and 10 mg/kg morphine. Morphine concentrat

  4. Prestorage leukofiltration of whole blood and SAGM blood prevents extracellular bioactive substance accumulation

    DEFF Research Database (Denmark)

    Mynster, T; Dybkjaer, E; Reimert, C M;

    1999-01-01

    unfiltered) were stored at + 4 degrees C for further 34 days. Samples were collected from all 40 half blood units on day 1, 21 and 35. Total content and extracellular concentration of myeloperoxidase (MPO), eosinophil cationic protein (ECP), histamine and plasminogen activator inhibitor-1 (PAI-1...

  5. Influence of complement on neutrophil extracellular trap release induced by bacteria

    DEFF Research Database (Denmark)

    Palmer, Lisa Joanne; Damgaard, Christian; Holmstrup, Palle;

    2016-01-01

    Background and Objectives Neutrophil extracellular trap (NET) release has generally been studied in the absence of serum, or at low concentrations of untreated or heat-inactivated serum. The influence of serum complement on NET release therefore remains unclear. We examined the DNA release induce...

  6. Na+ -K+ pump activity in rat peritoneal mast cells: inhibition by extracellular calcium

    DEFF Research Database (Denmark)

    Knudsen, Torben; Johansen, Torben

    1989-01-01

    of an enzyme, and it is mediated by the Na+ -K+ pump located in the plasma membrane. It is demonstrated that the activity of the Na+ -K+ pump mechanism is inhibited by low concentrations of extracellular calcium (0.1-1.2 mmol l-1). The possibility is discussed that calcium-deprivation may increase the pump...

  7. Extracellular matrix and tissue engineering applications

    NARCIS (Netherlands)

    Fernandes, Hugo; Moroni, Lorenzo; Blitterswijk, van Clemens; Boer, de Jan

    2009-01-01

    The extracellular matrix is a key component during regeneration and maintenance of tissues and organs, and it therefore plays a critical role in successful tissue engineering as well. Tissue engineers should recognise that engineering technology can be deduced from natural repair processes. Due to a

  8. Extracellular vesicles: fundamentals and clinical relevance

    Directory of Open Access Journals (Sweden)

    Wael Nassar

    2015-01-01

    Full Text Available All types of cells of eukaryotic organisms produce and release small nanovesicles into their extracellular environment. Early studies have described these vesicles as ′garbage bags′ only to remove obsolete cellular molecules. Valadi and colleagues, in 2007, were the first to discover the capability of circulating extracellular vesicles (EVs to horizontally transfer functioning gene information between cells. These extracellular vesicles express components responsible for angiogenesis promotion, stromal remodeling, chemoresistance, genetic exchange, and signaling pathway activation through growth factor/receptor transfer. EVs represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, signaling proteins, and RNAs. They contribute to physiology and pathology, and they have a myriad of potential clinical applications in health and disease. Moreover, vesicles can pass the blood-brain barrier and may perhaps even be considered as naturally occurring liposomes. These cell-derived EVs not only represent a central mediator of the disease microenvironment, but their presence in the peripheral circulation may serve as a surrogate for disease biopsies, enabling real-time diagnosis and disease monitoring. In this review, we′ll be addressing the characteristics of different types of extracellular EVs, as well as their clinical relevance and potential as diagnostic markers, and also define therapeutic options.

  9. Extracellular calmodulin: A polypeptide signal in plants?

    Institute of Scientific and Technical Information of China (English)

    孙大业; 唐文强; 马力耕

    2001-01-01

    Traditionally, calmodulin (CaM) was thought to be a multi-functional receptor for intracellular Ca2+ signals. But in the last ten years, it was found that CaM also exists and acts extracellularly in animal and plant cells to regulate many important physiological functions. Laboratory studies by the authors showed that extracellular CaM in plant cells can stimulate the proliferation of suspension cultured cell and protoplast; regulate pollen germination and pollen tube elongation,and stimulate the light-independent gene expression of Rubisco small subunit (rbcS). Furthermore,we defined the trans-membrane and intracellular signal transduction pathways for extracellular CaM by using a pollen system. The components in this pathway include heterotrimeric G-protein,phospholipase C, IP3, calcium signal and protein phosphorylation etc. Based on our findings, we suggest that extracellular CaM is a polypeptide signal in plants. This idea strongly argues against the traditional concept that there is no intercellular polypeptide signal in plants.

  10. Fragmentation of extracellular matrix by hypochlorous acid

    DEFF Research Database (Denmark)

    Woods, Alan A; Davies, Michael Jonathan

    2003-01-01

    The interaction of extracellular matrix with cells regulates their adhesion, migration and proliferation, and it is believed that damage to vascular matrix components is a factor in the development of atherosclerosis. Evidence has been provided for a role for the haem enzyme MPO (myeloperoxidase)...

  11. Estudo comparativo da eficiência de diferentes técnicas de mensuração da concentração espermática em suínos Efficiency of different measurement techniques of sperm concentration in swine

    Directory of Open Access Journals (Sweden)

    Wagner Loesch Vianna

    2004-12-01

    Full Text Available A inseminação artificial (IA em suínos é uma técnica cada vez mais utilizada na suinocultura moderna, pois propicia ao suinocultor vantagens quanto ao desempenho dos reprodutores, ao controle dos cruzamentos e à facilidade na introdução de material genético. Objetivando o aperfeiçoamento da técnica de IA, foram avaliadas a acurácia, a precisão e a robustez do Espermiodensímetro (ESPERMIO e do Espectrofotômetro (ESPECTRO, em comparação à Câmara de Neubauer. Utilizaram-se 142 ejaculados, que revelaram concentrações espermáticas médias (em milhões de sptz/mL e número médio de doses que poderiam ser produzidas, respectivamente, de 229,1 e 22,6; 185,0 e 18,5; 283,6 e 28,0 para a Câmara de Neubauer, o Espectrofotômetro e o Espermiodensímetro. O viés médio (acurácia e o desvio-padrão do viés médio (precisão do ESPECTRO, em comparação à Câmara de Neubauer, foram, respectivamente, de - 44,1 e 52,6, enquanto para o ESPERMIO foram de 54,5 e 44,8 (milhões de sptz/mL. Pode-se inferir que o ESPECTRO tende a subestimar e o ESPERMIO, a superestimar a concentração espermática, em comparação à Câmara de Neubauer. O ESPECTRO foi mais acurado e igualmente preciso que o ESPERMIO. A influência do volume de ejaculado sobre os resultados do ESPERMIO e do ESPECTRO pode ser comprovada pelos resultados de robustez para o volume do ejaculado.Artificial Insemination (AI in swines is a rising technique that has been used during the last years at the swine production systems, because it furnish several advantages to the producers just like boar high efficiency, better breeding control and easiness in introducing foreign genetic materials. Accuracy, precision and robustness for ejaculation volume of spermdensimeter (ESPERMIO and spectrofotometer (ESPECTRO in relation to the Neubauer Count, designed as the standard technique, were evaluated objectifying higher performance of AI technique. A total of 142 boar ejaculation was used

  12. Extracellular superoxide production, viability and redox poise in response to desiccation in recalcitrant Castanea sativa seeds.

    Science.gov (United States)

    Roach, Thomas; Beckett, Richard P; Minibayeva, Farida V; Colville, Louise; Whitaker, Claire; Chen, Hongying; Bailly, Christophe; Kranner, Ilse

    2010-01-01

    Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-intolerant 'recalcitrant' seeds. However, it is unknown if and how ROS are produced in the apoplast and if they play a role in stress signalling during desiccation. We studied intracellular damage and extracellular superoxide (O(2)(.-)) production upon desiccation in Castanea sativa seeds, mechanisms of O(2)(.-) production and the effect of exogenously supplied ROS. A transient increase in extracellular O(2)(.-) production by the embryonic axes preceded significant desiccation-induced viability loss. Thereafter, progressively more oxidizing intracellular conditions, as indicated by a significant shift in glutathione half-cell reduction potential, accompanied cell and axis death, coinciding with the disruption of nuclear membranes. Most hydrogen peroxide (H(2)O(2))-dependent O(2)(.-) production was found in a cell wall fraction that contained extracellular peroxidases (ECPOX) with molecular masses of approximately 50 kDa. Cinnamic acid was identified as a potential reductant required for ECPOX-mediated O(2)(.-) production. H(2)O(2), applied exogenously to mimic the transient ROS burst at the onset of desiccation, counteracted viability loss of sub-lethally desiccation-stressed seeds and of excised embryonic axes grown in tissue culture. Hence, extracellular ROS produced by embryonic axes appear to be important signalling components involved in wound response, regeneration and growth.

  13. Composição em ácidos graxos e qualidade da carne de tourinhos Nelore e Canchim alimentados com dietas à base de cana-de-açúcar e dois níveis de concentrado Fatty acids composition and meat quality of Nellore and Canchim young bulls fed sugar cane-based diets with two concentrate levels

    Directory of Open Access Journals (Sweden)

    Alexandre Rodrigo Mendes Fernandes

    2009-02-01

    Full Text Available O objetivo neste trabalho foi avaliar a composição de ácidos graxos e a qualidade do contrafilé (músculo Longissimus lumborum de tourinhos das raças Nelore e Canchim. Os animais foram terminados em confinamento e alimentados com dietas contendo cana-de-açúcar e dois níveis de concentrado (40 e 60% na matéria seca. Os concentrados foram compostos de grãos de girassol, milho, farelo de soja, levedura seca de cana-de-açúcar, uréia e núcleo mineral. O delineamento experimental foi o inteiramente ao acaso, em esquema fatorial 2 × 2 (grupo genético × nível de concentrado. Não foram observadas diferenças nos teores de umidade, proteína e extrato etéreo da carne. Os animais da raça Nelore apresentaram maiores concentrações de ácido linoléico conjugado (0,52%, ácidos graxos insaturados (46,82% e também relações mais elevadas de ácidos graxos insaturados:saturados (1,02 e monoinsaturados:saturados (0,86 em comparação aos tourinhos da raça Canchim. Os tourinhos da raça Canchim apresentaram maior intensidade das cores vermelha e amarela no contrafilé e maior luminosidade da gordura de cobertura. Houve interação para força de cisalhamento, que foi menor nos tourinhos Nelore alimentados com 40% de concentrado. Tourinhos da raça Nelore apresentam carne com melhor composição de ácidos graxos na gordura intramuscular do ponto de vista da saúde humana.The objective of this work was to evaluate the fatty acids composition and the qualitative and chemical characteristics of the loin meat (Longissimus lumborum muscle of Nellore and Canchim young bulls. The animals were fedlot finished and fed sugar cane-based diets with two concentrate levels (40 and 60% of dry matter. The concentrates were formulated with sunflower grains, corn, soybean meal, dry sugar cane yeast from sugar and alcohol industry, urea and mineral mixture. The experimental design was a completely randomized design with a 2 × 2 factorial arrangement

  14. Concentration device

    DEFF Research Database (Denmark)

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  15. Conversion of cheese whey into a fucose- and glucuronic acid-rich extracellular polysaccharide by Enterobacter A47.

    Science.gov (United States)

    Antunes, Sílvia; Freitas, Filomena; Alves, Vítor D; Grandfils, Christian; Reis, Maria A M

    2015-09-20

    Cheese whey was used as the sole substrate for the production of extracellular polysaccharides (EPS) by Enterobacter A47. An EPS concentration of 6.40 g L(-1) was reached within 3.2 days of cultivation, corresponding to a volumetric productivity of 2.00 g L(-1) d(-1). The produced EPS was mainly composed of glucuronic acid (29 mol%) and fucose (29 mol%), with lower contents of glucose and galactose (21 mol% each) and a total acyl groups content of 32 wt.%. The polymer had an average molecular weight of 1.8×10(6) Da, with a polydispersity index of 1.2, and an intrinsic viscosity of 8.0 dL g(-1). EPS aqueous solutions (1.0 wt.% in 0.01 M NaCl, at pH 8.0) presented a shear thinning behavior with a viscosity of the first Newtonian plateau approaching 0.1 Pas. This novel glucuronic acid-rich polymer possesses interesting rheological properties, which, together with its high content of glucuronic acid and fucose, two bioactive sugar monomers, confers it a great potential for use in high-value applications, such as cosmetics and pharmaceuticals.

  16. Purification and Characterization of an Extracellular Dextransucrase from Pediococcus pentosaceus Isolated from the Soil of North East India

    Directory of Open Access Journals (Sweden)

    Damini Kothari

    2011-01-01

    Full Text Available The extracellular dextransucrase produced from Pediococcus pentosaceus, a new isolate from the soil in Assam, India, was purified and characterized. The enzyme activity of cell-free supernatant was 3.4 U/mL and specific activity was 0.6 U/mg. The crude enzyme was purified by a single-step fractionation using polyethylene glycols of different molecular mass. The specific activity achieved was 18 U/mg with 31-fold purification by PEG 400 and 26 U/mg with 45-fold purification by PEG 1500. The molecular mass of dextransucrase determined by non-denaturing SDS-PAGE was approx. 180 kDa. The dextran formation activity of the enzyme was confirmed by activity staining. Optimum conditions for dextransucrase activity were: pH=5.4, reaction temperature 30 °C, 5 % sucrose and 20 mM sodium acetate buffer. A concentration of 1 mM MgCl2 and 6 mM CaCl2 enhanced dextransucrase activity by 5 and 150 %, respectively. The chaotropic agent urea (7 M and chelating agent EDTA (1 mM resulted in the residual enzyme activity of 98 and 80 %, respectively. The organic solvents such as ethanol (50 %, DMSO (90 %, acetone (50 % and acetonitrile (20 % decreased the dextransucrase activity by 80, 91, 94 and 80 %, respectively.

  17. Characterization of an extracellular biofunctional alginate lyase from marine Microbulbifer sp. ALW1 and antioxidant activity of enzymatic hydrolysates.

    Science.gov (United States)

    Zhu, Yanbing; Wu, Liyun; Chen, Yanhong; Ni, Hui; Xiao, Anfeng; Cai, Huinong

    2016-01-01

    A novel alginate-degrading marine bacterium Microbulbifer sp. ALW1 was isolated from rotten brown alga. An extracellular alginate lyase was purified to electrophoretic homogeneity and had a molecular mass of about 26.0 kDa determined by SDS-PAGE and size exclusion chromatography. This enzyme showed activities towards both polyguluronate and polymannuronate indicating its bifunctionality while with preference for the former substrate. Using sodium alginate as a substrate, strain ALW1 alginate lyase was optimally active at 45 °C and pH 7.0. It was stable at 25 °C, 30 °C, 35 °C and 40 °C, but not stable at 50 °C. This alginate lyase showed good stability over a broad pH range (5.0-9.0). The enzyme activity was increased to 5.1 times by adding NaCl to a final concentration of 0.5M. Strain ALW1 alginate lyase produced disaccharide (majority) and trisaccharide from alginate indicating that this enzyme could be a good tool for preparation of alginate oligosaccharides with low degree of polymerization (DP). The alginate oligosaccharides displayed the scavenging abilities towards radicals (DPPH, ABTS(+) and hydroxyl) and the reducing power. Therefore, the hydrolysates exhibited the antioxidant activity and had potential as a natural antioxidant.

  18. Activity-Dependent Changes in Extracellular Ca2+ and K+ Reveal Pacemakers in the Spinal Locomotor-Related Network

    OpenAIRE

    Brocard, Frédéric; Shevtsova, Natalia A.; Bouhadfane, Mouloud; Tazerart, Sabrina; Heinemann, Uwe; Rybak, Ilya A.; Vinay, Laurent

    2013-01-01

    Changes in the extracellular ionic concentrations occur as a natural consequence of firing activity in large populations of neurons. The extent to which these changes alter the properties of individual neurons and the operation of neuronal networks remains unknown. Here, we show that the locomotor-like activity in the isolated neonatal rodent spinal cord reduces the extracellular calcium ([Ca2+]o) to 0.9 mM and increases the extracellular potassium ([K+]o) to 6 mM. Such changes in [Ca2+]o and...

  19. Extracellular proteins: Novel key components of metal resistance in cyanobacteria?

    Directory of Open Access Journals (Sweden)

    Joaquin eGiner-Lamia

    2016-06-01

    Full Text Available Metals are essential for all living organisms and required for fundamental biochemical processes. However, when in excess, metals can turn into highly-toxic agents able to disrupt cell membranes, alter enzymatic activities and damage DNA. Metal concentrations are therefore tightly controlled inside cells, particularly in cyanobacteria. Cyanobacteria are ecologically relevant prokaryotes that perform oxygenic photosynthesis and can be found in many different marine and freshwater ecosystems, including environments contaminated with heavy metals. As their photosynthetic machinery imposes high demands for metals, homeostasis of these micronutrients has been widely studied in cyanobacteria. So far, most studies have focused on how cells are capable of controlling their internal metal pools, with a strong bias towards the analysis of intracellular processes. Ultrastructure, modulation of physiology, dynamic changes in transcription and protein levels have been studied, but what takes place in the extracellular environment when cells are exposed to an unbalanced metal availability remains largely unknown. The interest in studying the subset of proteins present in the extracellular space has only recently begun and the identification and functional analysis of the cyanobacterial exoproteomes are just emerging. Remarkably, metal-related proteins such as the copper-chaperone CopM or the iron-binding protein FutA2 have already been identified outside the cell. With this perspective, we aim to raise the awareness that metal-resistance mechanisms are not yet fully known and hope to motivate future studies assessing the role of extracellular proteins on bacterial metal homeostasis, with a special focus on cyanobacteria.

  20. Fibrillin assemblies: extracellular determinants of tissue formation and fibrosis

    Directory of Open Access Journals (Sweden)

    Olivieri Jacopo

    2010-12-01

    Full Text Available Abstract The extracellular matrix (ECM plays a key role in tissue formation, homeostasis and repair, mutations in ECM components have catastrophic consequences for organ function and therefore, for the fitness and survival of the organism. Collagen, fibrillin and elastin polymers represent the architectural scaffolds that impart specific mechanic properties to tissues and organs. Fibrillin assemblies (microfibrils have the additional function of distributing, concentrating and modulating local transforming growth factor (TGF-β and bone morphogenetic protein (BMP signals that regulate a plethora of cellular activities, including ECM formation and remodeling. Fibrillins also contain binding sites for integrin receptors, which induce adaptive responses to changes in the extracellular microenvironment by reorganizing the cytoskeleton, controlling gene expression, and releasing and activating matrix-bound latent TGF-β complexes. Genetic evidence has indicated that fibrillin-1 and fibrillin-2 contribute differently to the organization and structural properties of non-collagenous architectural scaffolds, which in turn translate into discrete regulatory outcomes of locally released TGF-β and BMP signals. Additionally, the study of congenital dysfunctions of fibrillin-1 has yielded insights into the pathogenesis of acquired connective tissue disorders of the connective tissue, such as scleroderma. On the one hand, mutations that affect the structure or expression of fibrillin-1 perturb microfibril biogenesis, stimulate improper latent TGF-β activation, and give rise to the pleiotropic manifestations in Marfan syndrome (MFS. On the other hand, mutations located around the integrin-binding site of fibrillin-1 perturb cell matrix interactions, architectural matrix assembly and extracellular distribution of latent TGF-β complexes, and lead to the highly restricted fibrotic phenotype of Stiff Skin syndrome. Understanding the molecular similarities and

  1. The Pathophysiology of Extracellular Hemoglobin Associated with Enhanced Oxidative Reactions

    Directory of Open Access Journals (Sweden)

    Joseph M Rifkind

    2015-01-01

    Full Text Available Hemoglobin (Hb continuously undergoes autoxidation producing superoxide which dismutates into hydrogen peroxide (H2O2 and is a potential source for subsequent oxidative reactions. Autoxidation is most pronounced under hypoxic conditions in the microcirculation and for unstable dimers formed at reduced Hb concentrations. In the red blood cell (RBC, oxidative reactions are inhibited by an extensive antioxidant system. For extracellular Hb, whether from hemolysis of RBCs and/or the infusion of Hb-based blood substitutes, the oxidative reactions are not completely neutralized by the available antioxidant system. Un-neutralized H2O2 oxidizes ferrous and ferric Hbs to Fe(IV-ferrylHb and oxyferrylHb, respectively. FerrylHb further reacts with H2O2 producing heme degradation products and free iron. OxyferrylHb, in addition to Fe(IV contains a free radical that can undergo additional oxidative reactions. Fe(IIIHb produced during Hb autoxidation also readily releases heme, an additional source for oxidative stress. These oxidation products are a potential source for oxidative reactions in the plasma, but to a greater extent when the lower molecular weight Hb dimers enter cells and tissues. Heme and oxyferryl have been shown to have a proinflammatory effect further increasing their potential for oxidative stress. These oxidative reactions contribute to a number of pathological situations including atherosclerosis, kidney malfunction, sickle cell disease and malaria. The toxic effects of extracellular Hb are of particular concern for increased hemolysis due to hemolytic anemia. Hemolysis is further exacerbated in various diseases and their treatments. Blood transfusions are required whenever there is an appreciable decrease in RBCs due to hemolysis or blood loss. It is, therefore, essential that transfused blood, whether stored RBCs or blood obtained by an Autologous Blood Recovery System from the patient, does not further increase extracellular Hb.

  2. The plasticity of extracellular fluid homeostasis in insects.

    Science.gov (United States)

    Beyenbach, Klaus W

    2016-09-01

    In chemistry, the ratio of all dissolved solutes to the solution's volume yields the osmotic concentration. The present Review uses this chemical perspective to examine how insects deal with challenges to extracellular fluid (ECF) volume, solute content and osmotic concentration (pressure). Solute/volume plots of the ECF (hemolymph) reveal that insects tolerate large changes in all three of these ECF variables. Challenges beyond those tolerances may be 'corrected' or 'compensated'. While a correction simply reverses the challenge, compensation accommodates the challenge with changes in the other two variables. Most insects osmoregulate by keeping ECF volume and osmotic concentration within a wide range of tolerance. Other insects osmoconform, allowing the ECF osmotic concentration to match the ambient osmotic concentration. Aphids are unique in handling solute and volume loads largely outside the ECF, in the lumen of the gut. This strategy may be related to the apparent absence of Malpighian tubules in aphids. Other insects can suspend ECF homeostasis altogether in order to survive extreme temperatures. Thus, ECF homeostasis in insects is highly dynamic and plastic, which may partly explain why insects remain the most successful class of animals in terms of both species number and biomass.

  3. Oxidative and other posttranslational modifications in extracellular vesicle biology.

    Science.gov (United States)

    Szabó-Taylor, Katalin; Ryan, Brent; Osteikoetxea, Xabier; Szabó, Tamás G; Sódar, Barbara; Holub, Marcsilla; Németh, Andrea; Pálóczi, Krisztina; Pállinger, Éva; Winyard, Paul; Buzás, Edit I

    2015-04-01

    Extracellular vesicles including exosomes, microvesicles and apoptotic vesicles, are phospholipid bilayer surrounded structures secreted by cells universally, in an evolutionarily conserved fashion. Posttranslational modifications such as oxidation, citrullination, phosphorylation and glycosylation play diverse roles in extracellular vesicle biology. Posttranslational modifications orchestrate the biogenesis of extracellular vesicles. The signals extracellular vesicles transmit between cells also often function via modulating posttranslational modifications of target molecules, given that extracellular vesicles are carriers of several active enzymes catalysing posttranslational modifications. Posttranslational modifications of extracellular vesicles can also contribute to disease pathology by e.g. amplifying inflammation, generating neoepitopes or carrying neoepitopes themselves.

  4. Concentrated Ownership

    DEFF Research Database (Denmark)

    Rose, Caspar

    2014-01-01

    , especially minority shareholders. Concentrated ownership is associated with benefits and costs. Concentrated ownership may reduce agency costs by increased monitoring of top management. However, concentrated ownership may also provide dominating owners with private benefits of control.......This entry summarizes the main theoretical contributions and empirical findings in relation to concentrated ownership from a law and economics perspective. The various forms of concentrated ownership are described as well as analyzed from the perspective of the legal protection of investors...

  5. Crescimento ponderal de filhotes de tartaruga gigante da Amazônia (Podocnemis expansa submetidos a tratamento com rações isocalóricas contendo diferentes níveis de proteína bruta Body growth of one-month giant Amazonian turtle (Podocnemis Expansa fed isocaloric diet with different levels of crude protein concentration

    Directory of Open Access Journals (Sweden)

    Vinicius Augusto Sá

    2004-12-01

    Full Text Available A criação de Podocnemis expansa, a tartaruga-da-amazônia, com finalidade comercial foi implantada no Brasil em 1992. Contudo, muitas questões acerca do manejo, da nutrição, da sanidade e, principalmente, da reprodução ainda são obscuras. Visando contribuir para o desenvolvimento de uma metodologia alimentar da espécie, objetivou-se testar diferentes níveis de proteína da dieta. Uma amostra de 480 animais neonatos de, aproximadamente, um mês de vida foram trazidos de uma área de proteção localizada no rio Araguaia no Estado Goiás para o Núcleo de Pscicultura Experimental/UFG. Os animais foram divididos em seis grupos de 80 animais e colocados em caixas de água de 500 litros. Cinco grupos receberam rações formuladas com diferentes teores de proteína bruta (PB vegetal: PB 18% (PB18, PB 21% (PB21, PB 24% (PB24, PB 27% (PB27 e PB 30% (PB30, enquanto o outro grupo (PBA30 recebeu ração comercial para peixes contendo proteína de origem animal (30% de PB. Bimestralmente, foram realizadas biometrias para determinação das medidas de comprimento (CC e largura da carapaça (LC, comprimento da carapaça (CP e largura do plastrão (LP e do peso corporal (PC. O experimento demonstrou superioridade do tratamento PBA30 em todas as medidas estudadas, seguidos seqüencialmente pelos tratamentos PB30, PB27, sem diferenças significativas entre estes grupos. Os piores resultados foram para os grupos PB24, PB21 e PB18, que não diferiam entre si. Filhotes de P. expansa nos dez primeiros meses de vida alimentados com dietas contendo elevados percentuais de proteína bruta (acima de 27% respondem melhor em termos de crescimento e ganho de peso que aqueles alimentados com dietas com percentuais mais baixos. A dieta contendo proteína bruta de origem animal apresentou melhores resultados que as de origem vegetal.The domestication of Podocnemis expansa (Gigant Amazonian turtle with commercial purpose it was implanted in Brazil in 1992. However, a

  6. Dinâmica da concentração de mercado na indústria Brasileira, 1996-2003 Dynamics of market concentration in the Brazilian industry, 1996-2003

    OpenAIRE

    Frederico Rocha

    2010-01-01

    O objetivo desse trabalho é estudar a mudança na concentração dos mercados da indústria brasileira de mineração e transformação entre 1996 e 2003, realizando uma decomposição do índice de Herfindahl-Hirschman em variação da distribuição do tamanho e do número de empresas. Os resultados obtidos sugerem que, na média, a indústria sofreu reduzida mudança no período; contudo, apontam que, em um grupo de indústrias, as mudanças no nível de concentração foram substanciais. Indicam também que a maio...

  7. Influência do teor de nitrogênio no cultivo de Spirulina maxima em duas temperaturas - Parte I: Alteração da composição da biomassa Influence of nitrogen concentration on the culture of Spirulina maxima grown at two temperatures - Part I: Changes in biomass composition

    Directory of Open Access Journals (Sweden)

    Gilvair Marconi dos Santos

    2003-12-01

    Full Text Available Spirulina maxima é uma cianobactéria de grande interesse para a produção de substâncias nutritivas e terapêuticas. É mesofílica, essencialmente fotoautotrófica, sendo suas principais fontes de nitrogênio os nitratos, uréia ou sais de amônio em meios com alta alcalinidade [1, 2, 3, 10, 16]. Spirulina maxima foi cultivada em fermentadores, expostos a luz com intensidade de 2400lux, contendo 3L do meio proposto por PAOLETTI, PUSHPARAJ & TOMASELLI [7] com concentração de 2,5g/L de KNO3, em meio modificado com 0,2g/L de KNO3 e em meio sem fonte de nitrogênio, denominados respectivamente meios 2,5N, 0,2N e SN, visando observar as alterações provocadas em sua composição final. Em culturas crescidas a 35ºC observou-se redução do teor de proteínas na massa celular seca de 28,84% e de 32,87%, aumento do teor de carboidratos de 30,34% e de 54,21% e aumento dos lipídios totais de 287,90% e 277,37%, quando se utilizou os meios 0,2N e SN, respectivamente, em comparação com o meio 2,5N. O teor de cinzas mostrou variação desprezível. Quando a temperatura de cultivo foi reduzida para 25ºC, ocorreu uma redução do teor de proteínas da massa seca de 40,28% e 39,02%, aumento de teor de carboidratos de 88,90% e de 91,15% e aumento do teor de lipídios totais em 321,25% e de 307,08%, quando se utilizou os meios 0,2N e SN em comparação com o meio 2,5N, respectivamente. Os resultados mostraram alterações sensíveis na composição da biomassa seca, com a diminuição do teor de nitrogênio e da temperatura de cultivo, exceto no teor de cinzas que não foi significativo.Spirulina maxima is a cianobacter of great interest to the production of nutritious and therapeutic substances. It is mesophilic, essentially fotoautotrophic and has preference for media with high alkalinity. Its principal nitrogen source are nitrates and ammonium salts or urea [1, 2, 3, 10, 16]. Spirulina maxima was cultured in fermentors with 3 liters of medium

  8. An easy ratiometric compensation for the extracellular Ca2+ indicator-caused fluorescence artifact.

    Science.gov (United States)

    Kukkonen, Jyrki P

    2009-07-15

    Measurement of intracellular Ca(2+) dynamics is one of the most central real-time assays for cellular signaling. Ratiometric methods reduce the need for internal calibration and also effectively compensate for most artifacts when used in imaging. However, ratiometric calculation cannot compensate for extracellularly leaked (and fluorescent) Ca(2+) indicator and will instead indicate erroneous Ca(2+) concentration. This frequently occurs in systems where extracellular indicator is accumulated such as fluorescence spectrophotometers and plate readers. Here I present a method that, for the first time, fully compensates for this phenomenon. The method uses a single-step internal calibration together with a predefined ratiometric calibration protocol.

  9. Determination of extracellular kynurenic acid in the striatum of unanesthetized rats: effect of aminooxyacetic acid

    DEFF Research Database (Denmark)

    Speciale, C; Wu, H Q; Gramsbergen, J B

    1990-01-01

    ). In the presence of KYN (50-2000 microM), KYNA concentration in the dialysate increased continuously to reach steady-state levels after 2h of perfusion. Introduction of the unspecific transaminase inhibitor aminooxyacetic acid (AOAA) through the dialysis probe caused a progressive decrease of extracellular KYNA......, which reached dose-dependent minimal levels within 2 h. One mM AOAA caused an almost complete depletion of KYNA in the dialysate. These data demonstrate that extracellular KYNA can be assessed by microdialysis and that AOAA can be used as a tool to examine the neurobiology of KYNA in awake, freely...

  10. Efeitos da concentração de Tm3+ nas propriedades de cerâmicas do sistema (Pb,La(Zr,TiO3 Effects of the Tm3+ concentration on the properties of (Pb,La(Zr,TiO3 ceramics

    Directory of Open Access Journals (Sweden)

    E. R. Botero

    2009-09-01

    Full Text Available As propriedades estruturais, ferroelétricas e dielétricas do sistema cerâmico ferroelétrico (Pb0,91La0,09(Zr0,65Ti0,35O3, PLZT, dopado com Tm, foram investigadas em função da concentração de dopante adicionada à matriz. Os corpos cerâmicos foram preparados pelo método convencional de síntese de estado sólido. Por meio da análise dos perfis de difração de raios X foi possível identificar a formação da fase cristalina desejada, perovskita, com simetria indistinta da cúbica e uma pequena concentração de uma fase secundária, rica em Tm3+ e Zr4+, para concentrações de dopante > 1.7% em mol. Os valores dos parâmetros de rede mostraram a existência de no mínimo dois processos de incorporação dos dopantes pela matriz de PLZT. Por meio da caracterização das propriedades elétricas, também foi possível observar os efeitos da incorporação de íons Tm3+ pela rede cristalina do PLZT, concordando com os resultados encontrados pelas caracterizações estruturais.This study explores the structural, ferroelectric and dielectric properties of the Tm-doped (Pb0.91La0.09(Zr0.65Ti0.35O3 (PLZT ferroelectric system as a function of the dopant concentration in the ferroelectric matrix. The ceramic bodies were prepared by the conventional solid state synthesis method. The X-ray diffraction pattterns reveal a formation of the desired crystalline phase, perovskite, with pseudo-cubic symmetry plus a small amount of a secondary phase for the dopant concentration > 1.7 mol%, constituted mainly by Tm3+ and Zr4+. The lattice volume, evaluated by the diffraction peaks position, showed at least two dopant incorporation mechanism on the PLZT matrix. From the electrical properties it was possible to verify the effects of the dopant ion Tm3+ occupancy in the PLZT lattice, in agreement with the structural results.

  11. Ascorbic acid: Nonradioactive extracellular space marker in canine heart

    Energy Technology Data Exchange (ETDEWEB)

    Reil, G.H.; Frombach, R.; Kownatzki, R.; Quante, W.; Lichtlen, P.R. (Medizinische Hochschule Hannover (West Germany))

    1987-11-01

    The distribution pattern of ascorbic acid and L-({sup 14}C)ascorbic acid in myocardial tissue was compared with those of the classical radioactive extracellular space markers ({sup 3}H)-inulin, ({sup 3}H)sucrose, and Na{sup 82}Br. A new polarographic techniques was developed for analogue registration of ascorbic acid concentration in coronary venous blood. The kinetic data of the markers were studied in an open-chest canine heart preparation during a constant tracer infusion of up to 9 min. Distribution volumes were calculated based on the mean transit time method of Zierler. The distribution volume of ascorbic acid as well as of L-({sup 14}C)ascorbic acid in myocardial tissue agreed closely with those of ({sup 3}H)inulin and ({sup 3}H)sucrose as well as {sup 82}Br. The obtained kinetic data confirmed that ascorbic acid exhibits the physicochemical properties of an extracellular space marker, though this compound was shown to leak slowly into myocardial cells. Favorable attributes of this indicator are its low molecular weight, high diffusibility in interstitial fluid, low binding affinity to macromolecules, and high transcapillary as well as low transplasmalemmal penetration rate. Therefore, this nonradioactive marker can be applied in a safe and simple fashion, and without untoward side effects in experimental animals as well as in patients.

  12. Microfluidic partitioning of the extracellular space around single cardiac myocytes.

    Science.gov (United States)

    Klauke, Norbert; Smith, Godfrey L; Cooper, Jonathan M

    2007-02-01

    This paper describes the partitioning of the extracellular space around an electrically activated single cardiac myocyte, constrained within a microfluidic device. Central to this new method is the production of a hydrophobic gap-structure, which divides the extracellular space into two distinct microfluidic pools. The content of these pools was controlled using a pair of concentric automated pipets (subsequently called "dual superfusion pipet"), each providing the ability to dispense (i.e., the source, inner pipet) and aspirate (the sink, outer pipet) a buffer solution (perfusate) into each of the two pools. For rapid solution switching around the cell, additional dual superfusion pipets were inserted into the microchannel for defined time periods using a piezostepper, enabling us to add a test solution, such as a drug. Three distinct areas of the cell were manipulated, namely, the microfluidic environment, the cellular membrane, and the intracellular space. Planar integrated microelectrodes enabled the electrical stimulation of the cardiomyocyte and the recording of the evoked action potential. The device was mounted on an inverted microscope to allow simultaneous sarcomere length and epifluorescence measurements during evoked electrical activity, including, for example, the response of the stimulated end of the cardiac myocyte in comparison with the untreated cell end.

  13. Extracellular N-acetylaspartate depletion in traumatic brain injury.

    Science.gov (United States)

    Belli, Antonio; Sen, Jon; Petzold, Axel; Russo, Salvatore; Kitchen, Neil; Smith, Martin; Tavazzi, Barbara; Vagnozzi, Roberto; Signoretti, Stefano; Amorini, Angela Maria; Bellia, Francesco; Lazzarino, Giuseppe

    2006-02-01

    N-Acetylaspartate (NAA) is almost exclusively localized in neurons in the adult brain and is present in high concentration in the CNS. It can be measured by proton magnetic resonance spectroscopy and is seen as a marker of neuronal damage and death. NMR spectroscopy and animal models have shown NAA depletion to occur in various types of chronic and acute brain injury. We investigated 19 patients with traumatic brain injury (TBI). Microdialysis was utilized to recover NAA, lactate, pyruvate, glycerol and glutamate, at 12-h intervals. These markers were correlated with survival and a 6-month Glasgow Outcome Score. Eleven patients died and eight survived. A linear mixed model analysis showed a significant effect of outcome and of the interaction between time of injury and outcome on NAA levels (p = 0.009 and p = 0.004, respectively). Overall, extracellular NAA was 34% lower in non-survivors. A significant non-recoverable fall was observed in this group from day 4 onwards, with a concomitant rise in lactate-pyruvate ratio and glycerol. These results suggest that mitochondrial dysfunction is a significant contributor to poor outcome following TBI and propose extracellular NAA as a potential marker for monitoring interventions aimed at preserving mitochondrial function.

  14. Extracellular pH modulates GABAergic neurotransmission in rat hypothalamus.

    Science.gov (United States)

    Chen, Z L; Huang, R Q

    2014-06-20

    Changes in extracellular pH have a modulatory effect on GABAA receptor function. It has been reported that pH sensitivity of the GABA receptor is dependent on subunit composition and GABA concentration. Most of previous investigations focused on GABA-evoked currents, which only reflect the postsynaptic receptors. The physiological relevance of pH modulation of GABAergic neurotransmission is not fully elucidated. In the present studies, we examined the influence of extracellular pH on the GABAA receptor-mediated inhibitory neurotransmission in rat hypothalamic neurons. The inhibitory postsynaptic currents (IPSCs), tonic currents, and the GABA-evoked currents were recorded with whole-cell patch techniques on the hypothalamic slices from Sprague-Dawley rats at 15-26 postnatal days. The amplitude and frequency of spontaneous GABA IPSCs were significantly increased while the external pH was changed from 7.3 to 8.4. In the acidic pH (6.4), the spontaneous GABA IPSCs were reduced in amplitude and frequency. The pH induced changes in miniature GABA IPSCs (mIPSCs) similar to that in spontaneous IPSCs. The pH effect on the postsynaptic GABA receptors was assessed with exogenously applied varying concentrations of GABA. The tonic currents and the currents evoked by sub-saturating concentration of GABA ([GABA]) (10 μM) were inhibited by acidic pH and potentiated by alkaline pH. In contrast, the currents evoked by saturating [GABA] (1mM) were not affected by pH changes. We also investigated the influence of pH buffers and buffering capacity on pH sensitivity of GABAA receptors on human recombinant α1β2γ2 GABAA receptors stably expressed in HEK 293 cells. The pH influence on GABAA receptors was similar in HEPES- and MES-buffered media, and not dependent on protonated buffers, suggesting that the observed pH effect on GABA response is a specific consequence of changes in extracellular protons. Our data suggest that the hydrogen ions suppress the GABAergic neurotransmission

  15. Analysis of the inter- and extracellular formation of platinum nanoparticles by Fusarium oxysporum f. sp. lycopersici using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Riddin, T L [Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, PO Box 94, Grahamstown (South Africa); Gericke, M [MINTEK, Private Bag X3015, Randburg 2125 (South Africa); Whiteley, C G [Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, PO Box 94, Grahamstown (South Africa)

    2006-07-28

    Fusarium oxysporum fungal strain was screened and found to be successful for the inter- and extracellular production of platinum nanoparticles. Nanoparticle formation was visually observed, over time, by the colour of the extracellular solution and/or the fungal biomass turning from yellow to dark brown, and their concentration was determined from the amount of residual hexachloroplatinic acid measured from a standard curve at 456 nm. The extracellular nanoparticles were characterized by transmission electron microscopy. Nanoparticles of varying size (10-100 nm) and shape (hexagons, pentagons, circles, squares, rectangles) were produced at both extracellular and intercellular levels by the Fusarium oxysporum. The particles precipitate out of solution and bioaccumulate by nucleation either intercellularly, on the cell wall/membrane, or extracellularly in the surrounding medium. The importance of pH, temperature and hexachloroplatinic acid (H{sub 2}PtCl{sub 6}) concentration in nanoparticle formation was examined through the use of a statistical response surface methodology. Only the extracellular production of nanoparticles proved to be statistically significant, with a concentration yield of 4.85 mg l{sup -1} estimated by a first-order regression model. From a second-order polynomial regression, the predicted yield of nanoparticles increased to 5.66 mg l{sup -1} and, after a backward step, regression gave a final model with a yield of 6.59 mg l{sup -1}.

  16. Analysis of the inter- and extracellular formation of platinum nanoparticles by Fusarium oxysporum f. sp. lycopersici using response surface methodology

    Science.gov (United States)

    Riddin, T. L.; Gericke, M.; Whiteley, C. G.

    2006-07-01

    Fusarium oxysporum fungal strain was screened and found to be successful for the inter- and extracellular production of platinum nanoparticles. Nanoparticle formation was visually observed, over time, by the colour of the extracellular solution and/or the fungal biomass turning from yellow to dark brown, and their concentration was determined from the amount of residual hexachloroplatinic acid measured from a standard curve at 456 nm. The extracellular nanoparticles were characterized by transmission electron microscopy. Nanoparticles of varying size (10-100 nm) and shape (hexagons, pentagons, circles, squares, rectangles) were produced at both extracellular and intercellular levels by the Fusarium oxysporum. The particles precipitate out of solution and bioaccumulate by nucleation either intercellularly, on the cell wall/membrane, or extracellularly in the surrounding medium. The importance of pH, temperature and hexachloroplatinic acid (H2PtCl6) concentration in nanoparticle formation was examined through the use of a statistical response surface methodology. Only the extracellular production of nanoparticles proved to be statistically significant, with a concentration yield of 4.85 mg l-1 estimated by a first-order regression model. From a second-order polynomial regression, the predicted yield of nanoparticles increased to 5.66 mg l-1 and, after a backward step, regression gave a final model with a yield of 6.59 mg l-1.

  17. Extracellular Ca2+ Is Required for Fertilization in the African Clawed Frog, Xenopus laevis.

    Science.gov (United States)

    Wozniak, Katherine L; Mayfield, Brianna L; Duray, Alexis M; Tembo, Maiwase; Beleny, David O; Napolitano, Marc A; Sauer, Monica L; Wisner, Bennett W; Carlson, Anne E

    2017-01-01

    The necessity of extracellular Ca2+ for fertilization and early embryonic development in the African clawed frog, Xenopus laevis, is controversial. Ca2+ entry into X. laevis sperm is reportedly required for the acrosome reaction, yet fertilization and embryonic development have been documented to occur in high concentrations of the Ca2+ chelator BAPTA. Here we sought to resolve this controversy. Using the appearance of cleavage furrows as an indicator of embryonic development, we found that X. laevis eggs inseminated in a solution lacking added divalent cations developed normally. By contrast, eggs inseminated in millimolar concentrations of BAPTA or EGTA failed to develop. Transferring embryos to varying solutions after sperm addition, we found that extracellular Ca2+ is specifically required for events occurring within the first 30 minutes after sperm addition, but not after. We found that the fluorescently stained sperm were not able to penetrate the envelope of eggs inseminated in high BAPTA, whereas several had penetrated the vitelline envelope of eggs inseminated without a Ca2+ chelator, or with BAPTA and saturating CaCl2. Together these results indicate that fertilization does not occur in high concentrations of Ca2+ chelators. Finally, we found that the jelly coat includes >5 mM of readily diffusible Ca2+. Taken together, these data are consistent with requirement of extracellular Ca2+ for fertilization. Based on our findings, we hypothesize that the jelly coat surrounding the egg acts as a reserve of readily available Ca2+ ions to foster fertilization in changing extracellular milieu.

  18. Desnutrição materna durante a lactação em ratos Wistar: efeitos sobre as fibras elásticas da matriz extracelular na traqueia dos filhotes Maternal malnutrition during lactation in Wistar rats: effects on elastic fibers of the extracellular matrix in the trachea of offspring

    Directory of Open Access Journals (Sweden)

    Filipe Moreira de Andrade

    2012-10-01

    Full Text Available OBJETIVO: Investigar os efeitos da desnutrição proteica materna durante a lactação sobre as fibras elásticas da traqueia de filhotes de ratos Wistar. MÉTODOS: Ao nascimento, 12 filhotes machos de duas ratas Wistar foram igualmente divididos em dois grupos: grupo controle, cuja mãe recebeu água e dieta padrão de laboratório ad libitum durante a lactação, e grupo restrição proteica (RP, cuja mãe recebeu água ad libitum e dieta isoenergética com RP (8% de proteína. Aos 21 dias de vida, os filhotes foram sacrificados, e suas traqueias foram ressecadas. As fibras elásticas foram coradas pelo método de resorcina-fucsina de Weigert (precedido de oxidação e avaliadas sob microscopia óptica. As determinações morfométricas foram feitas por estereologia, utilizando o método de contagem de pontos, e expressas em densidade volumétrica. RESULTADOS: As fibras elásticas foram identificadas abaixo da mucosa traqueal, sendo a maioria em distribuição longitudinal. Além disso, camadas circulares bem definidas de fibras elásticas envolviam as superfícies interna e externa do anel cartilaginoso. Não houve diferenças entre os grupos quanto à organização e distribuição das fibras elásticas. A densidade volumétrica das fibras elásticas dos filhotes nos grupos controle e RP foi de, respectivamente, 2,46 ± 0,99% e 3,25 ± 1,13% (p OBJECTIVE: To investigate the effects of maternal protein malnutrition during lactation on the elastic fibers in the tracheas of Wistar rat pups. METHODS: At delivery, 12 male pups of two Wistar rat dams were equally divided into two groups: control, in which the dam received water and standard rat chow ad libitum during lactation; and protein-restricted (PR, in which the dam received water ad libitum and an isoenergetic PR diet (8% protein. At 21 days of age, the pups were killed and their tracheas were excised. The elastic fibers were stained with Weigert's resorcin-fuchsin (after oxidation and

  19. Efeito da injeção de diferentes concentrações de cloreto de cálcio na textura e aceitabilidade de carne bovina maturada Effeet of different concentration of calcium chloride in texture and aceitability of aged beef

    Directory of Open Access Journals (Sweden)

    Riana Jordão Barrozo Heinemann

    2003-12-01

    Full Text Available A maturação a vácuo é uma das alternativas tecnológicas mais utilizadas para melhorar e padronizar a textura da carne bovina. Nesse processo, o amaciamento decorre da ação de enzimas proteolíticas endógenas, dentre as quais se destacam as calpaínas, cuja atividade depende da presença de íons cálcio livres no sarcoplasma. Por isso, a adição de soluções de cloreto de cálcio promove um incremento na proteólise durante a maturação. No entanto, dependendo da concentração, esse sal pode causar a formação de sabor desagradável. Assim, neste trabalho, avaliou-se o efeito da adição, na razão de 5% (v/p, de soluções 100, 200 e 300mM de CaCl2, seguida de maturação por 14 dias, na proteólise, maciez e sabor de amostras de carne bovina (m. Longissimus dorsi. A fragmentação miofibrilar foi intensificada e a força de cisalhamento diminuída pelo aumento da concentração salina. O efeito da concentração de cloreto de cálcio sobre a aceitabilidade das amostras foi melhor representado por uma curva de resposta de efeito quadrático, cuja equação indicou que a concentração mais adequada para a aplicação desse procedimento tecnológico é de 181,14mM. Os resultados obtidos demonstram que a adição de solução de cloreto de cálcio, seguida de maturação, representa uma possibilidade tecnológica para melhoria de qualidade de carne bovina in natura.Vacuum aging is one of the technological alternatives to improve and standard beef texture. In this process, the tenderization derives from endogenous proteolytic enzymes action, where calpains are involved and their activity is dependent on the level of free calcium in the sarcoplasm. The direct addition of calcium increases proteolysis during aging, but in some concentrations may cause off-flavor. This work evaluated the effect of addition, on a 5% (v/w basis, of 100, 200 and 300mM of CaCl2 solutions followed by vacuum aging for 14 days, on fragmentation, tenderness and

  20. Involvement of extracellular matrix constituents in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lochter, Andre; Bissell, Mina J

    1995-06-01

    It has recently been established that the extracellular matrix is required for normal functional differentiation of mammary epithelia not only in culture, but also in vivo. The mechanisms by which extracellular matrix affects differentiation, as well as the nature of extracellular matrix constituents which have major impacts on mammary gland function, have only now begun to be dissected. The intricate variety of extracellular matrix-mediated events and the remarkable degree of plasticity of extracellular matrix structure and composition at virtually all times during ontogeny, make such studies difficult. Similarly, during carcinogenesis, the extracellular matrix undergoes gross alterations, the consequences of which are not yet precisely understood. Nevertheless, an increasing amount of data suggests that the extracellular matrix and extracellular matrix-receptors might participate in the control of most, if not all, of the successive stages of breast tumors, from appearance to progression and metastasis.

  1. Extracellular matrix component signaling in cancer

    DEFF Research Database (Denmark)

    Multhaupt, Hinke A. B.; Leitinger, Birgit; Gullberg, Donald

    2016-01-01

    Cell responses to the extracellular matrix depend on specific signaling events. These are important from early development, through differentiation and tissue homeostasis, immune surveillance, and disease pathogenesis. Signaling not only regulates cell adhesion cytoskeletal organization and motil...... as well as matrix constitution and protein crosslinking. Here we summarize roles of the three major matrix receptor types, with emphasis on how they function in tumor progression. [on SciFinder(R)]......Cell responses to the extracellular matrix depend on specific signaling events. These are important from early development, through differentiation and tissue homeostasis, immune surveillance, and disease pathogenesis. Signaling not only regulates cell adhesion cytoskeletal organization...... and motility but also provides survival and proliferation cues. The major classes of cell surface receptors for matrix macromols. are the integrins, discoidin domain receptors, and transmembrane proteoglycans such as syndecans and CD44. Cells respond not only to specific ligands, such as collagen, fibronectin...

  2. Biotechnological Aspects of Microbial Extracellular Electron Transfer

    Science.gov (United States)

    Kato, Souichiro

    2015-01-01

    Extracellular electron transfer (EET) is a type of microbial respiration that enables electron transfer between microbial cells and extracellular solid materials, including naturally-occurring metal compounds and artificial electrodes. Microorganisms harboring EET abilities have received considerable attention for their various biotechnological applications, in addition to their contribution to global energy and material cycles. In this review, current knowledge on microbial EET and its application to diverse biotechnologies, including the bioremediation of toxic metals, recovery of useful metals, biocorrosion, and microbial electrochemical systems (microbial fuel cells and microbial electrosynthesis), were introduced. Two potential biotechnologies based on microbial EET, namely the electrochemical control of microbial metabolism and electrochemical stimulation of microbial symbiotic reactions (electric syntrophy), were also discussed. PMID:26004795

  3. Extracellular hydrogen peroxide produced under irradiation as the most important factor in the lethality of gamma-irradiated Paramecium tetraurelia

    Energy Technology Data Exchange (ETDEWEB)

    Croute, F.; Soleilhavoup, J.P.; Vidal, S.; Dupouy, D.; Planel, H. (Laboratoire de Biologie Medicale, 31 - Toulouse (France))

    1982-02-01

    It has been shown that the surviving fraction of ..gamma..-irradiated paramecia is correlated with the residual H/sub 2/O/sub 2/ concentration in the extracellular medium which is strongly dependent on the bacterial concentration, that is, on the enzyme content in the culture medium.

  4. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  5. Tetraspanins in Extracellular Vesicle Formation and Function

    OpenAIRE

    Andreu, Zoraida; Yáñez-Mó, María

    2014-01-01

    Extracellular vesicles (EVs) represent a novel mechanism of intercellular communication as vehicles for intercellular transfer of functional membrane and cytosolic proteins, lipids, and RNAs. Microvesicles, ectosomes, shedding vesicles, microparticles, and exosomes are the most common terms to refer to the different kinds of EVs based on their origin, composition, size, and density. Exosomes have an endosomal origin and are released by many different cell types, participating in different phy...

  6. Tetraspanins in Extracellular Vesicle formation and function

    OpenAIRE

    Zoraida Andreu Martínez; María eYáñez-Mó

    2014-01-01

    Extracellular vesicles (EVs) represent a novel mechanism of intercellular communication as vehicles for intercellular transfer of functional membrane and cytosolic proteins, lipids, and RNAs. Microvesicles, ectosomes, shedding vesicles, microparticles and exosomes are the most common terms to refer to the different kinds of EVs based on their origin, composition, size and density. Exosomes have an endosomal origin and are released by many different cell types, participating in different physi...

  7. Matrix Extracellular Phosphoglycoprotein Inhibits Phosphate Transport

    OpenAIRE

    Marks, J; Churchill, L J; Debnam, E. S.; Unwin, R J

    2008-01-01

    The role of putative humoral factors, known as phosphatonins, in phosphate homeostasis and the relationship between phosphate handling by the kidney and gastrointestinal tract are incompletely understood. Matrix extracellular phosphoglycoprotein (MEPE), one of several candidate phosphatonins, promotes phosphaturia, but whether it also affects intestinal phosphate absorption is unknown. Here, using the in situ intestinal loop technique, we demonstrated that short-term infusion of MEPE inhibits...

  8. Engineering hydrogels as extracellular matrix mimics

    OpenAIRE

    Geckil, Hikmet; Xu, Feng; Zhang, Xiaohui; Moon, SangJun; Demirci, Utkan

    2010-01-01

    Extracellular matrix (ECM) is a complex cellular environment consisting of proteins, proteoglycans, and other soluble molecules. ECM provides structural support to mammalian cells and a regulatory milieu with a variety of important cell functions, including assembling cells into various tissues and organs, regulating growth and cell–cell communication. Developing a tailored in vitro cell culture environment that mimics the intricate and organized nanoscale meshwork of native ECM is desirable....

  9. Dark production of extracellular superoxide by the coral Porites astreoides and representative symbionts

    Directory of Open Access Journals (Sweden)

    Tong Zhang

    2016-11-01

    Full Text Available The reactive oxygen species (ROS superoxide has been implicated in both beneficial and detrimental processes in coral biology, ranging from pathogenic disease resistance to coral bleaching. Despite the critical role of ROS in coral health, there is a distinct lack of ROS measurements and thus an incomplete understanding of underpinning ROS sources and production mechanisms within coral systems. Here, we quantified in situ extracellular superoxide concentrations at the surfaces of aquaria-hosted Porites astreoides during a diel cycle. High concentrations of superoxide (~10’s of nM were present at coral surfaces, and these levels did not change significantly as a function of time of day. These results indicate that the coral holobiont produces extracellular superoxide in the dark, independent of photosynthesis. As a short-lived anion at physiological pH, superoxide has a limited ability to cross intact biological membranes. Further, removing surface mucus layers from the P. astreoides colonies did not impact external superoxide concentrations. We therefore attribute external superoxide derived from the coral holobiont under these conditions to the activity of the coral host epithelium, rather than mucus-derived epibionts or internal sources such as endosymbionts (e.g., Symbiodinium. However, endosymbionts likely contribute to internal ROS levels via extracellular superoxide production. Indeed, common coral symbionts, including multiple strains of Symbiodinium (clades A to D and the bacterium Endozoicomonas montiporae LMG 24815, produced extracellular superoxide in the dark and at low light levels. Further, representative P. astreoides symbionts, Symbiodinium CCMP2456 (clade A and E. montiporae, produced similar concentrations of superoxide alone and in combination with each other, in the dark and low light, and regardless of time of day. Overall, these results indicate that healthy, non-stressed P. astreoides and representative symbionts produce

  10. Bordetella parapertussis Circumvents Neutrophil Extracellular Bactericidal Mechanisms

    Science.gov (United States)

    Gorgojo, Juan; Scharrig, Emilia; Gómez, Ricardo M.; Harvill, Eric T.; Rodríguez, Maria Eugenia

    2017-01-01

    B. parapertussis is a whooping cough etiological agent with the ability to evade the immune response induced by pertussis vaccines. We previously demonstrated that in the absence of opsonic antibodies B. parapertussis hampers phagocytosis by neutrophils and macrophages and, when phagocytosed, blocks intracellular killing by interfering with phagolysosomal fusion. But neutrophils can kill and/or immobilize extracellular bacteria through non-phagocytic mechanisms such as degranulation and neutrophil extracellular traps (NETs). In this study we demonstrated that B. parapertussis also has the ability to circumvent these two neutrophil extracellular bactericidal activities. The lack of neutrophil degranulation was found dependent on the O antigen that targets the bacteria to cell lipid rafts, eventually avoiding the fusion of nascent phagosomes with specific and azurophilic granules. IgG opsonization overcame this inhibition of neutrophil degranulation. We further observed that B. parapertussis did not induce NETs release in resting neutrophils and inhibited NETs formation in response to phorbol myristate acetate (PMA) stimulation by a mechanism dependent on adenylate cyclase toxin (CyaA)-mediated inhibition of reactive oxygen species (ROS) generation. Thus, B. parapertussis modulates neutrophil bactericidal activity through two different mechanisms, one related to the lack of proper NETs-inducer stimuli and the other one related to an active inhibitory mechanism. Together with previous results these data suggest that B. parapertussis has the ability to subvert the main neutrophil bactericidal functions, inhibiting efficient clearance in non-immune hosts. PMID:28095485

  11. Extracellular quality control in the epididymis

    Institute of Scientific and Technical Information of China (English)

    Gail A. Cornwall; H. Henning von Horsten; Douglas Swartz; Seethal Johnson; Kim Chau; Sandra Whelly

    2007-01-01

    The epididymal lumen represents a unique extracellular environment because of the active sperm maturation process that takes place within its confines. Although much focus has been placed on the interaction of epididymal secretory proteins with spermatozoa in the lumen, very little is known regarding how the complex epididymal milieu as a whole is maintained, including mechanisms to prevent or control proteins that may not stay in their native folded state following secretion. Because some misfolded proteins can form cytotoxic aggregate structures known as amyloid, it is likely that control/surveillance mechanisms exist within the epididymis to protect against this process and allow sperm maturation to occur. To study protein aggregation and to identify extracellular quality control mechanisms in the epididymis, we used the cystatin family of cysteine protease inhibitors, including cystatin-related epididymal spermatogenic and cystatin C as molecular models because both proteins have inherent properties to aggregate and form amyloid. In this chapter, we present a brief summary of protein aggregation by the amyloid pathway based on what is known from other organ systems and describe quality control mechanisms that exist intracellularly to control protein misfolding and aggregation. We then present a summary of our studies of cystatinrelated epididymal spermatogenic (CRES) oligomerization within the epididymal lumen, including studies suggesting that transglutaminase cross-linking may be one mechanism of extracellular quality control within the epididymis.

  12. EXTRACELLULAR VESICLES: CLASSIFICATION, FUNCTIONS AND CLINICAL RELEVANCE

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    A. V. Oberemko

    2014-12-01

    Full Text Available This review presents a generalized definition of vesicles as bilayer extracellular organelles of all celular forms of life: not only eu-, but also prokaryotic. The structure and composition of extracellular vesicles, history of research, nomenclature, their impact on life processes in health and disease are discussed. Moreover, vesicles may be useful as clinical instruments for biomarkers, and they are promising as biotechnological drug. However, many questions in this area are still unresolved and need to be addressed in the future. The most interesting from the point of view of practical health care represents a direction to study the effect of exosomes and microvesicles in the development and progression of a particular disease, the possibility of adjusting the pathological process by means of extracellular vesicles of a particular type, acting as an active ingredient. Relevant is the further elucidation of the role and importance of exosomes to the surrounding cells, tissues and organs at the molecular level, the prospects for the use of non-cellular vesicles as biomarkers of disease.

  13. Extracellular conversion of adiponectin hexamers into trimers

    Science.gov (United States)

    Kim, Jeong-a; Nuñez, Martha; Briggs, David B.; Laskowski, Bethany L.; Chhun, Jimmy J.; Eleid, Joseph K.; Quon, Michael J.; Tsao, Tsu-Shuen

    2012-01-01

    Adiponectin is an adipocyte-secreted hormone that exists as trimers, hexamers and larger species collectively referred to as HMW (high-molecular-weight) adiponectin. Whether hexamers or HMW adiponectin serve as precursors for trimers outside the circulation is currently unknown. Here, we demonstrate that adiponectin trimers can be generated from larger oligomers secreted from primary rat adipose cells or differentiated 3T3-L1 adipocytes. Purified hexameric, but not HMW, adiponectin converted into trimers in conditioned media separated from 3T3-L1 adipocytes or, more efficiently, when enclosed in the dialysis membrane in the presence of adipocytes. Several lines of evidence indicate that the conversion is mediated by an extracellular redox system. First, N-terminal epitope-tagged hexamers converted into trimers without proteolytic removal of the tag. Secondly, appearance of trimers was associated with conversion of disulfide-bonded dimers into monomers. Thirdly, thiol-reactive agents inhibited conversion into trimers. Consistent with a redox-based mechanism, purified hexamers reductively converted into trimers in defined glutathione redox buffer with reduction potential typically found in the extracellular environment while the HMW adiponectin remained stable. In addition, conversion of hexamers into trimers was enhanced by NADPH, but not by NADP+. Collectively, these data strongly suggest the presence of an extracellular redox system capable of converting adiponectin oligomers. PMID:22973892

  14. Extracellular DNA: the tip of root defenses?

    Science.gov (United States)

    Hawes, Martha C; Curlango-Rivera, Gilberto; Wen, Fushi; White, Gerard J; Vanetten, Hans D; Xiong, Zhongguo

    2011-06-01

    This review discusses how extracellular DNA (exDNA) might function in plant defense, and at what level(s) of innate immunity this process might operate. A new role for extracellular factors in mammalian defense has been described in a series of studies. These studies reveal that cells including neutrophils, eosinophils, and mast cells produce 'extracellular traps' (ETs) consisting of histone-linked exDNA. When pathogens are attracted to such ETs, they are trapped and killed. When the exDNA component of ETs is degraded, trapping is impaired and resistance against invasion is reduced. Conversely, mutation of microbial genes encoding exDNases that degrade exDNA results in loss of virulence. This discovery that exDNases are virulence factors opens new avenues for disease control. In plants, exDNA is required for defense of the root tip. Innate immunity-related proteins are among a group of >100 proteins secreted from the root cap and root border cell populations. Direct tests revealed that exDNA also is rapidly synthesized and exported from the root tip. When this exDNA is degraded by the endonuclease DNase 1, root tip resistance to fungal infection is lost; when the polymeric structure is degraded more slowly, by the exonuclease BAL31, loss of resistance to fungal infection is delayed accordingly. The results suggest that root border cells may function in a manner analogous to that which occurs in mammalian cells.

  15. Extracellular matrix proteins involved in pseudoislets formation.

    Science.gov (United States)

    Maillard, Elisa; Sencier, Marie-Christine; Langlois, A; Bietiger, William; Krafft, Mp; Pinget, Michel; Sigrist, Séverine

    2009-01-01

    Extracellular matrix proteins are known to mediate, through integrins, cell adhesion and are involved in a number of cellular processes, including insulin expression and secretion in pancreatic islets. We investigated whether expression of some extracellular matrix proteins were implied in islets-like structure formation, named pseudoislets. For this purpose, we cultured the β-cell line, RINm5F, during 1, 3, 5 and 7 days of culture on treated or untreated culture plate to form adherent cells or pseudoislets and analysed insulin, collagen IV, fibronectin, laminin 5 and β1-integrin expression. We observed that insulin expression and secretion were increased during pseudoislets formation. Moreover, we showed by immunohistochemistry an aggregation of insulin secreting cells in the centre of the pseudoislets. Peripheral β-cells of pseudoislets did not express insulin after 7 days of culture. RT-PCR and immunohistochemistry studies showed a transient expression of type IV collagen in pseudoislets for the first 3 days of culture. Study of fibronectin expression indicated that adherent cells expressed more fibronectin than pseudoislets. In contrast, laminin 5 was more expressed in pseudoislets than in adherent cells. Finally, expression of β1-integrin was increased in pseudoislets as compared to adherent cells. In conclusion, laminin 5 and collagen IV might be implicated in pseudoislets formation whereas fibronectin might be involved in cell adhesion. These data suggested that extracellular matrix proteins may enhance the function of pseudoislets.

  16. Intracellular Biopotentials During Static Extracellular Stimulation

    Science.gov (United States)

    Klee, Maurice

    1973-01-01

    Two properties of the intracellular potentials and electric fields resulting from static extracellular stimulation are obtained for arbitrarily shaped cells. First, the values of intracellular potential are shown to be bounded by the maximum and minimum values of extracellular potential on the surface of the cell. Second, the volume average of the magnitude of intracellular electric field is shown to have an upper bound given by the ratio of the magnitude of the largest extracellular potential difference on the surface of the cell to a generalized length constant λ = [σintraVcell/(σmemb Acell)]1/2, where Vcell and Acell are the volume and surface area of the cell, σintra is the intracellular conductivity (reciprocal ohms per centimeter), and σmemb is the membrane conductivity (reciprocal ohms per square centimeter). The use of the upper bound on the volume average of the magnitude of intracellular electric field as an estimate for intracellular isopotentiality is discussed and the use of the generalized length constant for electrically describing arbitrary cells is illustrated for cylindrical- and spheroidal-shaped cells. PMID:4726882

  17. An inhibitory effect of extracellular Ca2+ on Ca2+-dependent exocytosis.

    Directory of Open Access Journals (Sweden)

    Wei Xiong

    Full Text Available AIM: Neurotransmitter release is elicited by an elevation of intracellular Ca(2+ concentration ([Ca(2+](i. The action potential triggers Ca(2+ influx through Ca(2+ channels which causes local changes of [Ca(2+](i for vesicle release. However, any direct role of extracellular Ca(2+ (besides Ca(2+ influx on Ca(2+-dependent exocytosis remains elusive. Here we set out to investigate this possibility on rat dorsal root ganglion (DRG neurons and chromaffin cells, widely used models for studying vesicle exocytosis. RESULTS: Using photolysis of caged Ca(2+ and caffeine-induced release of stored Ca(2+, we found that extracellular Ca(2+ inhibited exocytosis following moderate [Ca(2+](i rises (2-3 µM. The IC(50 for extracellular Ca(2+ inhibition of exocytosis (ECIE was 1.38 mM and a physiological reduction (∼30% of extracellular Ca(2+ concentration ([Ca(2+](o significantly increased the evoked exocytosis. At the single vesicle level, quantal size and release frequency were also altered by physiological [Ca(2+](o. The calcimimetics Mg(2+, Cd(2+, G418, and neomycin all inhibited exocytosis. The extracellular Ca(2+-sensing receptor (CaSR was not involved because specific drugs and knockdown of CaSR in DRG neurons did not affect ECIE. CONCLUSION/SIGNIFICANCE: As an extension of the classic Ca(2+ hypothesis of synaptic release, physiological levels of extracellular Ca(2+ play dual roles in evoked exocytosis by providing a source of Ca(2+ influx, and by directly regulating quantal size and release probability in neuronal cells.

  18. An assay for the rate of removal of extracellular hydrogen peroxide by cells

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    Brett A. Wagner

    2013-01-01

    Full Text Available Cells have a wide range of capacities to remove extracellular hydrogen peroxide. At higher concentrations of extracellular H2O2 (micromolar the rate of removal can be approximated by a rate equation that is first-order in the concentration of H2O2 and cell density. Here we present a method to determine the observed rate constant for the removal of extracellular H2O2 on a per cell basis. In the cells examined, when exposed to 20 μM H2O2, these rate constants (kcell range from 0.46×10−12 s−1 cell−1 L for Mia-PaCa-2 cells (human pancreatic carcinoma to 10.4×10−12 s−1 cell−1 L for U937 cells (human histiocytic lymphoma. For the relatively small red blood cell kcell=2.9×10−12 s−1 cell−1 L. These rate constants, kcell, can be used to compare the capacity of cells to remove higher levels of extracellular H2O2, as often presented in cell culture experiments. They also provide a means to estimate the rate of removal of extracellular H2O2, rate=−kcell [H2O2] (cells L−1, and the half-life of a bolus of H2O2. This information is essential to optimize experimental design and interpret data from experiments that expose cells to extracellular H2O2.

  19. Purification and characterization of an extracellular protease from Clonostachys rosea

    Institute of Scientific and Technical Information of China (English)

    LI Jun; HUANG Xiao-wei; ZHANG Ke-qin

    2004-01-01

    @@ An extracellular protease from Clonostachys rosea (syn. Gliocladium roseum) was purified to SDSPAGE homogeneity with 14-fold purification by ultrafiltration、 ammonium sulfate precipetation、hydrophobic interaction chromatography and anion exchange chromatography. The molecular weight of the protease was 32 kDa as estimated by SDS-PAGE. The N-terminal sequence of first 10 amino acids was A-T-Q-S-N-A-P-W-G-L. This enzyme exhibited pH and temperature optima of 9-10 and 60℃, respectively, and was stable over a wide range of pH 4-10 and temperature 4-50 ℃. It did not require Ca2+ for activity and thermal stability. Pre-incubation of enzyme with Zn2+ , Cu2+ , Hg2+,Fe3+ inhibited most of the enzyme activity, but Mn2+ increased enzyme activity up to 38%. It remained stable in the presence of Tween20, H2O2, EDTA. The inhibition profile of the enzymes by PMSF, suggested that this purified protease belongs to the serine protease family. The protease could immobilize nematodes (Panagrellus redivirus) in bioassays and hydrolyzed proteins of the purified cuticle.

  20. [Thermostable extracellular cyclic nucleotide phosphodiesterase from Physarum polycephalum plasmodium].

    Science.gov (United States)

    Nezvetskiĭ, A R; Orlova, T G; Beĭlina, S I; Orlov, N Ia

    2006-01-01

    The cyclic nucleotide phosphodiesterase secreted by Physarum polycephalum plasmodium into extracellular medium has been partially purified by DEAE cellulose chromatography, ultrafiltration, and HPLC. The results obtained by gel filtration, HPLC, electrophoresis, and isoelectric focusing suggest that, the native enzyme in solution is a monomer with a molecular mass of about 90 kDa and pI in the range 3.6 - 4.0. The Km values were estimated to be about 0.9 mM and 7.7 mM, respectively, and Vm for both substrates were similar (up to several thousand micromoles of cAMP hydrolyzed/hour per mg of enzyme). The partially purified enzyme was shown to be extremely stable. It did not lose the activity after heat treatment at 100 degrees C during 30 min. The enzyme was active in the presence of 1% SDS, but it was fully inactivated under the same conditions in the presence of beta-mercaptoethanol. The properties of the phosphodiesterase from Physarum polycephalum are discussed.

  1. Extracellular vesicles in multiple sclerosis: what are they telling us?

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    Matías eSáenz-Cuesta

    2014-03-01

    Full Text Available Extracellular vesicles (EVs are membrane-bound particles secreted by almost all cell types. They are classified depending on their biogenesis and size into exosomes and microvesicles or according to their cell origin. EVs play a role in cell-to-cell communication, including contact-free cell synapsis, carrying active membrane proteins, lipids, and genetic material both inside the particle and on their surface. They have been related to several physiological and pathological conditions. In particular, increasing concentrations of EVs have been found in many autoimmune diseases including multiple sclerosis (MS. MS is a central nervous system demyelinating disease characterized by relapsing of symptoms followed by periods of remission. Close interaction between endothelial cells, leukocytes, monocytes and cells from central nervous system is crucial for the development of MS. This review summarizes the pathological role of EVs in MS and the relationship of EVs with clinical characteristics, therapy and biomarkers of the disease.

  2. A novel extracellular peroxidase and nucleases from a milky sap of Chelidonium majus.

    Science.gov (United States)

    Nawrot, Robert; Lesniewicz, Krzysztof; Pienkowska, Joanna; Gozdzicka-Jozefiak, Anna

    2007-12-01

    Using affinity chromatography, SDS-PAGE, peroxidase activity assay and mass spectrometry data, a new extracellular peroxidase (CMP) from Chelidonium majus milky sap was isolated and characterized. The protein has a molecular weight of about 40 kDa and belongs to secretory class III plant peroxidases. The peroxidase activity is also accompanied by DN-ase activities. A novel CMP combined with other proteins is probably involved in development and differentiation of the plant and defence against different pathogens. It suggests that the biological activity of C. majus whole plants and extracts may depend not only on its alkaloidal content but also on the presence of biologically active proteins.

  3. Production and composition of extracellular polysaccharide synthesized by a Rhizobium isolate of Vigna mungo (L.) Hepper.

    Science.gov (United States)

    Mandal, Santi Mohan; Ray, Bimalendu; Dey, Satyahari; Pati, Bikas Ranjan

    2007-08-01

    An extracellular polysaccharide (EPS) was produced by a Rhizobium sp. isolated from the root nodules of Vigna mungo (L.) Hepper. Maximum EPS production (346 mg l(-1)) was when the yeast extract basal medium was supplemented with mannitol (1%), biotin (1.5 mg l(-1)) and asparagine (0.3%). Ribose (53%) and mannose (47%) were the principle monomers of the EPS. Chemical, chromatographic and spectroscopic analysis showed that this polymer, which has Man(4)Rib(1) as an oligomeric subunit, has an apparent molecular mass of 750 kDa.

  4. Efeito de um hidrolisado de proteínas de soro de leite e de seus peptídeos na proteção de lesões ulcerativas da mucosa gástrica de ratos Effects of a whey protein concentrate and it's peptides in the protection of ulcerative lesions at rat gastric mucosa

    Directory of Open Access Journals (Sweden)

    Maria Teresa Bertoldo Pacheco

    2006-02-01

    Full Text Available OBJETIVO: Avaliar a atividade do hidrolisado das proteínas de soro de leite bovino e uma fração de peptídeos de baixo peso molecular (peso molecular OBJECTIVE: To assess the ability of bovine whey protein hydrolysate and its low molecular weight fraction (molecular weight <1kDa to protect the gastric mucosa of rats against ulcerative process induced by three different agents. METHODS: Adult Wistar rats were subjected to the indomethacin-induced ulcer (30mg/kg body weigh, absolute ethanol (1ml/animal and immobilization and cold stress (4(0C/2h, models. RESULTS: Whey protein hydrolysate was obtained by treatment with pancreatin to a degree of hydrolysis of 20% and fractionated using a tangential flow membrane with a molecular weight cut-off of 1kDa to obtain the fraction containing low molecular weight peptides (<1kDa. In the ethanol-induced acute ulcer model (single dose, whey protein hydrolysate inhibited the gastric lesion index by 65.5% and the double dose resulted in a 77.4% inhibition. CONCLUSION: For the anti-inflammatory model, the cytoprotective effect of low molecular weight peptides was stronger than that of total hydrolysate (53.1 and 71.6%, ulcerative lesion index for single and double dose, respectively. No mucosa cytoprotective activity was found for whey protein concentrate, whey protein hydrolysate or WPHP in the immobilization and cold stress model.

  5. Desempenho e avaliação econômica da terminação de tourinhos em confinamento alimentados com diferentes níveis de concentrado na dieta Performance and economic evaluation of young finished feedlot bulls fed different concentrate levels in the diet

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    Regis Luis Missio

    2009-07-01

    Full Text Available Este estudo foi conduzido para avaliar o desempenho animal e a viabilidade econômica da utilização de diferentes níveis de concentrado na dieta no confinamento de tourinhos para abate entre 14-16 meses de idade. Foram utilizados 16 bovinos não-castrados alimentados com 22, 40, 59 ou 79% de concentrado na dieta, distribuídos em delineamento inteiramente ao acaso, com quatro repetições por tratamento. A idade e o peso médio inicial dos animais foram de 9,32 meses e 192 kg, respectivamente. A idade de abate, o peso final, o consumo de fibra em detergente neutro, a conversão alimentar e a lucratividade mensal diminuíram com o aumento do nível de concentrado. O consumo de matéria seca em porcentagem do peso vivo e do tamanho metabólicoapresentaram comportamento quadrático, aumentando até os níveis de 67 e 75% de concentrado na dieta, respectivamente. O consumo de energia digestível e o ganho de peso vivo médio diário apresentaram aumentos lineares com a elevação do nível de concentrado. O aumento do nível de concentrado da dieta de 22 para 79% aumenta o desempenho animal, mas reduz a lucratividade da terminação de tourinhos dos 14 aos 16 meses de idade.This study was conducted to evaluate the performance and economic viability of young bulls slaughtered at 14-16 months old, fed on different concentrate levels in the diet. Sixteen young bulls were randomly distributed and fed with 22, 40, 59 or 79% concentrate in the diet, resulting in four replications per treatment. The initial age and weight were 9.32 months and 192.44 kg, respectively. Final age, final weight, neutral fiber detergent intake, feed conversion and monthly profit decreased with increasing concentrate levels. The dry matter intake as percentage of live weight and metabolic size showed quadratic variation, increasing to 67 and 75% concentrate in the diet, respectively. The digestible energy intake and average daily weight gain increased with increases in

  6. The effect of ionic diffusion on extracellular potentials in neural tissue

    CERN Document Server

    Halnes, Geir; Keller, Daniel; Pettersen, Klas H; Eivenoll, Gaute T

    2015-01-01

    In computational neuroscience, it is common to use the simplifying assumption that diffusive currents are negligible compared to Ohmic currents. However, endured periods of intense neural signaling may cause local ion concentration changes in the millimolar range. Theoretical studies have identified scenarios where steep concentration gradients give rise to diffusive currents that are of comparable magnitude with Ohmic currents, and where the simplifying assumption that diffusion can be neglected does not hold. We here propose a novel formalism for computing (1) the ion concentration dynamics and (2) the electrical potential in the extracellular space surrounding multi-compartmental neuron models or networks of such (e.g., the Blue-Brain simulator). We use this formalism to explore the effects that diffusive currents can have on the extracellular (ECS) potential surrounding a small population of active cortical neurons. Our key findings are: (i) Sustained periods of neuronal output (simulations were run for 8...

  7. Local e extensão da digestão em terneiros desmamados alimentados "Ad Libitum" com dietas ricas em concentrado contendo diferentes fontes de proteína suplementar Site and extent of digestion by weaned calves fed "Ad Libitum" on high concentrate-rich diets with different supplemental protein sources

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    Gilberto Vilmar Kozloski

    1999-06-01

    Full Text Available Foram utilizados nove terneiros da raça Holandesa (139 ± 2,4kg, fistulados no duodeno, em um delineamento experimental completamente casualizado para estudar o efeito da suplementação com diferentes fontes protéicas (2% de uréia ou 10% de farinha de carne na dieta total de dietas ricas em concentrado (milho e farelo de soja sobre o local e extensão da digestão do alimento, em condições de consumo ad libitum. A relação volumoso:concentrado das dietas foi de 30:70. A digestibilidade ruminal e total da matéria seca, matéria orgânica e nitrogênio, assim como o fluxo duodenal de nitrogênio microbiano e residual do alimento, e a eficiência da síntese protéica microbiana foram semelhantes nos dois tratamentos (P>0,10. A digestibilidade ruminal do amido também foi semelhante, mas a digestibilidade total foi menor no tratamento com uréia (PNine weaned Holstein calves (139 ± 2.4kg fitted with duodenal cannulas were used in a completly ramdomized design to study the effects of supplemental protein sources (2% of urea or 10% of meat meal of high concentrate diets (corn and soybean meal on site and extent of digestion of feed, in ad libitum feeding conditions. The forage:concentrate ratio was 30:70. The ruminal and total digestibility of dry matter, organic matter and nitrogen, as well as microbial and feed residual nitrogen duodenal flow, and the microbial protein synthesis efficiency were similar for both treatments (P>0.10. The ruminal digestibility of starch was also similar, but total digestibility was lower for urea treatment (P<0.10. However, this is probably due more to the limited capacity of ruminants to digest starch in the intestines than to an effect of the protein supplement. The use of urea or meat meal, as supplemental protein sources for corn and soybean meal based diets, formulated to supply the growth requirements of calves fed ad libitum, did not affect the digestion process.Thus, the choise of the protein

  8. Increased extracellular dopamine and 5-hydroxytryptamine levels contribute to enhanced subthalamic nucleus neural activity during exhausting exercise

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    Y Hu

    2015-09-01

    Full Text Available The purpose of the study was to explore the mechanism underlying the enhanced subthalamic nucleus (STN neural activity during exhausting exercise from the perspective of monoamine neurotransmitters and changes of their corresponding receptors. Rats were randomly divided into microdialysis and immunohistochemistry study groups. For microdialysis study, extracellular fluid of the STN was continuously collected with a microdialysis probe before, during and 90 min after one bout of exhausting exercise. Dopamine (DA and 5-hydroxytryptamine (5-HT levels were subsequently detected with high-performance liquid chromatography (HPLC. For immunohistochemistry study, the expression of DRD 2 and HT 2C receptors in the STN, before, immediately after and 90 min after exhaustion was detected through immunohistochemistry technique. Microdialysis study results showed that the extracellular DA and 5-HT neurotransmitters increased significantly throughout the procedure of exhausting exercise and the recovery period (P0.05. Our results suggest that the increased extracellular DA and 5-HT in the STN might be one important factor leading to the enhanced STN neural activity and the development of fatigue during exhausting exercise. This study may essentially offer useful evidence for better understanding of the mechanism of the central type of exercise-induced fatigue.

  9. Rendimentos de carcaça, composição tecidual e musculosidade da perna de cordeiros alimentados com silagem de milho ou cana-de-açúcar em dois níveis de concentrado Carcass yield, tissue composition, and leg muscularity of lambs fed corn silage or sugar cane in two levels of concentrate

    Directory of Open Access Journals (Sweden)

    G.M.B. Moreno

    2010-06-01

    Full Text Available Avaliou-se o efeito da relação volumoso:concentrado e do tipo de volumoso nos rendimentos de carcaça e dos cortes comerciais, e sobre a composição dos tecidos e musculosidade da perna de 32 cordeiros Ile de France, terminados em confinamento, alimentados com silagem de milho ou cana-de-açúcar, em duas relações volumoso:concentrado: de 60:40 ou 40:60. Os cordeiros foram abatidos aos 32kg de peso corporal; calcularam-se o peso e o rendimento da carcaça quente (PCQ e RCQ. Após 24 horas de refrigeração, obtiveram-se o peso e o rendimento da carcaça fria (PCF e RCF, o rendimento verdadeiro e as perdas por resfriamento. As carcaças foram divididas em cinco cortes comerciais, paleta, lombo, perna, costelas e pescoço, e a perna foi dissecada em músculo, osso e gordura, calculando-se as relações músculo:osso e músculo:gordura, além do índice de musculosidade da perna. Os cordeiros alimentados com silagem de milho apresentaram maiores PCQ (16,05kg, PCF (15,61kg, RCQ (50,4% e RCF (49,0%. O rendimento de lombo foi menor nos cordeiros alimentados com cana-de-açúcar (9,1%. A cana-de-açúcar e a silagem de milho nas duas relações volumoso:concentrado estudadas não afetaram as proporções de osso, músculo e gordura e musculosidade da perna, e podem constituir a dieta desses animais sem diminuir as proporções desses tecidos, responsáveis pela qualidade da carne.The effects of roughage:concentrate ratio and type of roughage were evaluated on the carcass yield and commercial cuts, and tissue composition and leg muscularity of 32 Ile de France lambs finished in feedlot and fed corn silage or sugar cane in two roughage:concentrate ratios: 60:40 or 40:60. The lambs were slaughtered with 32kg of body weight and the weight and yield of hot carcass (WHC and YHC were determined. After refrigerated for 24h in cold camera, the weight and yield of cold carcass (WCC and YCC, real yield, and weight loss for cooling were obtained. The carcass

  10. Torque, myoeletric sygnal and heart rate responses during concentric and eccentric exercises in older men Torque, sinal eletromiográfico e respostas da frequência cardíaca durante exercícios concêntrico e excêntrico em homens idosos

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    Robison J. Quitério

    2011-02-01

    Full Text Available BACKGROUND: The literature reports that the eccentric muscular action produces greater force and lower myoelectric activity than the concentric muscular action, while the heart rate (HR responses are bigger during concentric contraction. OBJECTIVES: To investigate the maximum average torque (MAT, surface electromyographic (SEMG and the heart rate (HR responses during different types of muscular contraction and angular velocities in older men. METHODS: Twelve healthy men (61.7±1.6years performed concentric (C and eccentric (E isokinetic knee extension-flexion at 60º/s and 120º/s. SEMG activity was recorded from vastus lateralis muscle and normalized by Root Mean Square - RMS (µV of maximal isometric knee extension at 60º. HR (beats/min and was recorded at rest and throughout each contraction. The data were analyzed by the Friedman test for repeated measures with post hoc Dunn's test (pCONTEXTUALIZAÇÃO: A literatura refere que a ação muscular excêntrica produz maior força e menor atividade mioelétrica que a concêntrica, enquanto a resposta da frequência cardíaca (FC é maior durante a contração concêntrica que durante a excêntrica. OBJETIVOS: Investigar as respostas de torque médio máximo (TMM, eletromiografia de superfície (EMGs e FC durante diferentes tipos de contração muscular e velocidades angulares em homens idosos. MATERIAIS E MÉTODOS: Doze homens saudáveis (61,7±1,6 anos realizaram flexões e extensões do joelho concêntrica (C e excêntrica (E em 60º/s e 120º/s. Registrou-se a atividade EMGs do músculo vasto lateral e normalizou-se pela RMS (µV da extensão isométrica máxima do joelho em 60º. A FC (bpm foi registrada em repouso e durante cada contração. Os dados foram analisados utilizando-se o teste de Friedman para medidas repetidas com post hoc de Dunn (p<0,05. RESULTADOS: Os valores médios de TMM (N.m/kg foram menores e os de RMS (µV foram maiores (p<0,05 nas contrações concêntricas (C60º/s=2

  11. Características físico-químicas e sensoriais da carne de cordeiros terminados com dietas contendo cana-de-açúcar ou silagem de milho e dois níveis de concentrado Physic-chemical and sensorial characteristics of meat from lambs finished with diets containing sugar cane or corn silage and two levels of concentrate

    Directory of Open Access Journals (Sweden)

    André Gustavo Leão

    2012-05-01

    Full Text Available Com o objetivo de avaliar as características físico-químicas e sensoriais da carne de cordeiros terminados em confinamento com dietas contendo cana-de-açúcar ou silagem de milho em duas relações volumoso:concentrado, 60:40 ou 40:60, utilizaram-se 32 cordeiros Ile de France, não-castrados, com 15 kg de peso corporal. Os animais foram confinados em baias individuais e abatidos aos 32 kg. As dietas e os músculos estudados não influenciaram o pH aos 45 minutos (6,56 e 24 horas (5,62 após o abate nem a capacidade de retenção de água (58,38% e a perda de peso por cocção (34,04%. A cor da carne e da gordura subcutânea não diferiu entre as dietas, entretanto a cor da carne variou entre os músculos longissimus lumborum e triceps brachii. A força de cisalhamento (1,85 kgf/cm² não foi afetada pelas dietas, porém diferiu entre os músculos, com valores de 1,41 e 2,28 kgf/cm² para o longissimus lumborum e triceps brachii, respectivamente. Nas análises sensoriais do lombo e da paleta, foram obtidas para os cordeiros alimentados com cana-de-açúcar e maior quantidade de concentrado as maiores notas para sabor (8,07 e 8,26, textura (8,53 e 8,53, preferência (8,20 e 8,46 e aceitação (8,33 e 8,26, respectivamente. A cana-de-açúcar na alimentação de cordeiros em confinamento manteve a qualidade físicoquímica da carne, podendo ser utilizada nesta fase de produção e, quando associada a maior quantidade de concentrado na dieta, melhora a qualidade sensorial da carne de cordeiros.With the objective of evaluating physic-chemical and sensorial characteristics of meat from lambs finished in feedlot with diets containing sugar cane or corn silage at two roughage:concentrate ratios, 60:40 or 40:60, 32 non-castrated Ile de France lambs, with 15 kg body weight were used. Animals were confined in individual stalls and were slaughtered at 32 kg body weight. Studied diets and muscles did not affect pH at 45 minutes (6.56 and 24 hours (5

  12. Effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

    Institute of Scientific and Technical Information of China (English)

    Run-lan Yu; Jing Liu; Jian-xi Tan; Wei-min Zeng; Li-juan Shi; Guo-hua Gu; Wen-qing Qin; Guan-zhou Qiu

    2014-01-01

    The pH value plays an important role in the bioleaching of sulphide minerals. The effect of pH values on the extracellular poly-saccharide secreted by Acidithiobacillus ferrooxidans was investigated in different phases of bacterial growth during chalcopyrite bioleach-ing. It is found that extracellular polysaccharide secretion from the cells attached to chalcopyrite is more efficiently than that of the free cells in the bioleaching solution. Three factors, pH values, the concentration of soluble metal ions, and the bacterial growth and metabolism, affect extracellular polysaccharide secretion in the free cells, and are related to the bacterial growth phase. Extracellular polysaccharide secretion from the attached cells is mainly dependent on the pH value of the bacterial culture.

  13. Efeito da aplicação de hCG ou GnRH sobre a concentração sérica de progesterona e eficiência reprodutiva em porcas Effect of injection of hCG or GnRH on progesterone serum concentration and reproductive efficiency of sows

    Directory of Open Access Journals (Sweden)

    L.F.R. Carvalho

    2003-12-01

    Full Text Available Avaliou-se o efeito da aplicação de diferentes hormônios no quinto dia após a primeira inseminação sobre a concentração sérica de progesterona e sobre as características reprodutivas, em 103 porcas entre o terceirro e sexto parto. As matrizes foram divididas em: grupo-controle (n=35, não tratado, grupo GnRH (n=34, animais submetidos à aplicação intramuscular (IM de 50mcg de um análogo-GnRH no quinto dia após a primeira inseminação, e grupo hCG (n=34, animais submetidos à aplicação IM de 500UI de hCG no quinto dia após a primeira inseminação. A aplicação dos hormônios não influenciou as características reprodutivas taxa de parto, número total de nascidos, número de nascidos vivos e peso da leitegada (P>0,05. Cinco animais de cada grupo foram submetidos a coletas de sangue da veia cava nos dias 3, 5, 8, 12, 21 e 28 após a primeira inseminação para avaliação da concentração sérica de progesterona (ng/ml, utilizando a técnica de radioimunoensaio. Não houve diferença significativa quanto à concentração sérica de progesterona entre os grupos.Two different hormones were administered on the fifth day after the first insemination to evaluate their influence on serum progesterone concentrations and on reproductive efficiency, in multiparous sows between the third and the sixth parturition. The reproductive performance was evaluated in 103 sows distributed into three groups: 1-Control (n=35; 2-GnRH, 50m g of GnRH-analogue, administered IM on the fifth day after the first insemination (n=34; and 3-hCG, 500 IU of hCG administered IM in the fifth day after the first insemination (n=34. No effect (P>0.05 of hormone treatments on farrowing rate, litter size, live born and litter weight was observed. Five sows of each group were blood sampled on days 3, 5, 8, 12, 21, 28, after the first insemination, to evaluate serum progesterone concentrations (ng/ml. Serum progesterone concentrations were not affected (P>0.05 by

  14. Development of experimental structure and influence of high CO2 concentration in maize cro Desenvolvimento de estrutura experimentale influências da alta concentração de CO2 na cultura do milho

    Directory of Open Access Journals (Sweden)

    João B. Lopes da Silva

    2012-04-01

    Full Text Available Maize is a C4 plant that shows few or no response to high [CO2]. Thus, this study aimed to analyze the photosynthetic rate and yield of maize under high [CO2] and develop open-top chambers (OTC to create an atmosphere enriched with CO2. The experiment was conducted between October 2008 and March 2009. The OTCs were developed in modular scheme. Measurement of photosynthetic rates, transpiration, stomata conductance, grain yield and dry matter were performed. The experimental design was randomized blocks with four replications and three treatments: P1 - plants grown in OTC with 700 ppm [CO2], P2 - plants grown in OTC with environmental [CO2], and P3 - control, cultivated in open field. The results were analyzed by ANOVA and Tukey's test (PrO milho é uma planta C4 que apresenta pouca, ou nenhuma, resposta às elevadas [CO2]; assim, neste trabalho, objetivou-se analisar respostas fisiológicas e produtivas da cultura do milho sob alta [CO2], e desenvolver câmaras de topo aberto (CTA para criar uma atmosfera enriquecida com CO2. O experimento foi conduzido entre outubro de 2008 e março de 2009. As CTAs foram desenvolvidas em esquema modular. Foram realizadas medições da taxa fotossintética, transpiração, condutância estomática, produção de grãos e matéria seca. O delineamento experimental foi em blocos casualizados, com quatro repetições e três tratamentos: P1 - plantas cultivadas em CTA a [CO2] de 700ppm; P2 - plantas cultivadas em CTAcom [CO2] ambiente; e P3 -plantas cultivadas em campo aberto, testemunhas. Os resultados obtidos foram submetidos à análise de variância e teste de Tukey (Pr<0,05. As câmaras reduzem em 25% a Radiação Fotossinteticamente Ativa e aumentam a temperatura do ar e das folhas, em relação ao ambiente externo. As plantas sob alta [CO2] (P1 apresentaram as maiores taxas fotossintéticas e as menores condutâncias estomáticas e transpiração. O peso total dos grãos (g e a matéria seca da parte a

  15. Vibrio cholerae evades neutrophil extracellular traps by the activity of two extracellular nucleases.

    Directory of Open Access Journals (Sweden)

    Andrea Seper

    Full Text Available The Gram negative bacterium Vibrio cholerae is the causative agent of the secretory diarrheal disease cholera, which has traditionally been classified as a noninflammatory disease. However, several recent reports suggest that a V. cholerae infection induces an inflammatory response in the gastrointestinal tract indicated by recruitment of innate immune cells and increase of inflammatory cytokines. In this study, we describe a colonization defect of a double extracellular nuclease V. cholerae mutant in immunocompetent mice, which is not evident in neutropenic mice. Intrigued by this observation, we investigated the impact of neutrophils, as a central part of the innate immune system, on the pathogen V. cholerae in more detail. Our results demonstrate that V. cholerae induces formation of neutrophil extracellular traps (NETs upon contact with neutrophils, while V. cholerae in return induces the two extracellular nucleases upon presence of NETs. We show that the V. cholerae wild type rapidly degrades the DNA component of the NETs by the combined activity of the two extracellular nucleases Dns and Xds. In contrast, NETs exhibit prolonged stability in presence of the double nuclease mutant. Finally, we demonstrate that Dns and Xds mediate evasion of V. cholerae from NETs and lower the susceptibility for extracellular killing in the presence of NETs. This report provides a first comprehensive characterization of the interplay between neutrophils and V. cholerae along with new evidence that the innate immune response impacts the colonization of V. cholerae in vivo. A limitation of this study is an inability for technical and physiological reasons to visualize intact NETs in the intestinal lumen of infected mice, but we can hypothesize that extracellular nuclease production by V. cholerae may enhance survival fitness of the pathogen through NET degradation.

  16. Extracellular polymeric substances play roles in extracellular electron transfer of Shewanella oneidensis MR-1

    DEFF Research Database (Denmark)

    Xiao, Yong; Zhang, En-Hua; Christensen, Hans Erik Mølager

    It is well known that microorganism is surrounded by extracellular polymeric substances (EPS) which include polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and humic acids. However, previous studies on microbial extracellular electron transfer (EET) are conducted on cells...... the extraction (Figure 1.a and 1.b). Comparing to cells in control group, MR-1 treated at 38 °C for EPS extraction showed different electrochemical characterizations as revealed by differential pulse voltammetry (Figure 1.c). EPS extracted from MR-1 also was proved to be electrochemically active. The present...

  17. Resorbable extracellular matrix grafts in urologic reconstruction

    Directory of Open Access Journals (Sweden)

    Richard A. Santucci

    2005-06-01

    Full Text Available PURPOSE: There is an increasingly large body of literature concerning tissue-engineering products that may be used in urology. Some of these are quite complex (such as multilayer patient-specific cell-seeded implants yet the most simple and successful products to date are also the most uncomplicated: resorbable acellular extra-cellular matrices (ECMs harvested from animals. ECMs have been used in a variety of difficult urologic reconstruction problems, and this review is intended to summarize this complex literature for the practicing urologist. METHODS: Medline search of related terms such as "SIS, small intestinal submucosa, ECM, extracellular matrix, acellular matrix and urologic reconstruction". Manuscripts missed in the initial search were taken from the bibliographies of the primary references. RESULTS: Full review of potential clinical uses of resorbable extra-cellular matrices in urologic reconstruction. CONCLUSIONS: Currently, the "state of the art" in tissue engineering solutions for urologic reconstruction means resorbable acellular xenograft matrices. They show promise when used as a pubovaginal sling or extra bolstering layers in ureteral or urethral repairs, although recent problems with inflammation following 8-ply pubovaginal sling use and failures after 1- and 4-ply SIS repair of Peyronie's disease underscore the need for research before wide adoption. Preliminary data is mixed concerning the potential for ECM urethral patch graft, and more data is needed before extended uses such as bladder augmentation and ureteral replacement are contemplated. The distant future of ECMs in urology likely will include cell-seeded grafts with the eventual hope of producing "off the shelf" replacement materials. Until that day arrives, ECMs only fulfill some of the requirements for the reconstructive urologist.

  18. Managing Brain Extracellular K(+) during Neuronal Activity

    DEFF Research Database (Denmark)

    Larsen, Brian Roland; Stoica, Anca; MacAulay, Nanna

    2016-01-01

    reveal insights into pathological conditions such as epilepsy, migraine, and spreading depolarization following cerebral ischemia. In addition, particular neurological diseases occur as a result of mutations in the α2- (familial hemiplegic migraine type 2) and α3 isoforms (rapid-onset dystonia...... parkinsonism/alternating hemiplegia of childhood). This review addresses aspects of the Na(+)/K(+)-ATPase in the regulation of extracellular K(+) in the central nervous system as well as the related pathophysiology. Understanding the physiological setting in non-pathological tissue would provide a better...

  19. Biogenesis, delivery, and function of extracellular RNA

    Directory of Open Access Journals (Sweden)

    James G. Patton

    2015-08-01

    Full Text Available The Extracellular RNA (exRNA Communication Consortium was launched by the National Institutes of Health to focus on the extent to which RNA might function in a non-cell-autonomous manner. With the availability of increasingly sensitive tools, small amounts of RNA can be detected in serum, plasma, and other bodily fluids. The exact mechanism(s by which RNA can be secreted from cells and the mechanisms for the delivery and uptake by recipient cells remain to be determined. This review will summarize current knowledge about the biogenesis and delivery of exRNA and outline projects seeking to understand the functional impact of exRNA.

  20. Extracellular polymeric bacterial coverages as minimal surfaces

    CERN Document Server

    Saa, A; Saa, Alberto; Teschke, Omar

    2005-01-01

    Surfaces formed by extracellular polymeric substances enclosing individual and some small communities of {\\it Acidithiobacillus ferrooxidans} on plates of hydrophobic silicon and hydrophilic mica are analyzed by means of atomic force microscopy imaging. Accurate nanoscale descriptions of such coverage surfaces are obtained. The good agreement with the predictions of a rather simple but realistic theoretical model allows us to conclude that they correspond, indeed, to minimal area surfaces enclosing a given volume associated with the encased bacteria. This is, to the best of our knowledge, the first shape characterization of the coverage formed by these biomolecules, with possible applications to the study of biofilms.

  1. Bidirectional extracellular matrix signaling during tissue morphogenesis

    Science.gov (United States)

    Gjorevski, Nikolce; Nelson, Celeste M.

    2009-01-01

    Normal tissue development and function are regulated by the interplay between cells and their surrounding extracellular matrix (ECM). The ECM provides biochemical and mechanical contextual information that is conveyed from the cell membrane through the cytoskeleton to the nucleus to direct cell phenotype. Cells, in turn, remodel the ECM and thereby sculpt their local microenvironment. Here we review the mechanisms by which cells interact with, respond to, and influence the ECM, with particular emphasis placed on the role of this bidirectional communication during tissue morphogenesis. We also discuss the implications for successful engineering of functional tissues ex vivo. PMID:19896886

  2. Effect of oligogalacturonides on root length, extracellular alkalinization and O₂⁻-accumulation in alfalfa.

    Science.gov (United States)

    Camejo, Daymi; Martí, María C; Jiménez, Ana; Cabrera, Juan C; Olmos, Enrique; Sevilla, Francisca

    2011-04-15

    The effects of an oligogalacturonic acid (OGA) pool on root length of intact alfalfa seedlings (Medicago sativa L.), on extracellular pH and on both extracellular and intracellular O₂⁻ dynamics were examined in this study. Lower OGA concentrations (25, 50 and 75 μg mL⁻¹)promoted root length, but 50 μg mL⁻¹ had a stronger effect in promoting growth, while the higher OGA concentration (100 μg mL⁻¹)had no significant effect. Extracellular alkalinization was tested only at concentrations higher than 50 μg mL⁻¹ OGA, showing that the response is determined not only by the specific size of OGA, but also by the concentration of OGA. The promoting effect of OGA on root growth at 25, 50 and 75 μg mL⁻¹ OGA concentrations in alfalfa root appeared to be unrelated to extracellular alkalinization. A possible explanation could be the induction of an O₂⁻ burst at non-toxic levels, which could drive directly or indirectly several processes associated with root elongation in 25, 50 and 75 μg mL⁻¹ OGA-treated seedlings. Analyses using confocal microscopy showed that the increase in the O₂⁻ generation, mainly in the epidermal cells, induced by 50 μg mL⁻¹ OGA could be related to the promoting effect on root growth. The combination of OGA with DPI allowed us to demonstrate that there are different O₂⁻-generating sources in the epidermal cells of the meristematic zone, likely NADPH oxidase and oxidases or oxido-reductase enzymes, insensitive to DPI, that maintain detectable O₂⁻ accumulation at 60 and 120 min of treatment. These results suggest that OGA induce an oxidative burst by several O₂⁻-generating sources in the active growth zones.

  3. Assessment of metal concentrations in sediment samples from Billings Reservoir, Rio Grande tributary, Sao Paulo, Brazil; Avaliacao da concentracao de metais em amostras de sedimento do Reservatorio Billings, Braco Rio Grande, Sao Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Bostelmann, Eleine

    2006-07-01

    The present study chemically characterized sediment samples from the Billings reservoir, Rio Grande tributary, in the Metropolitan region of Sao Paulo, by determining metal concentration and other elements of interest. The chosen chemical parameters for this characterization were Aluminum, Arsenic, Barium, Cadmium, Copper, Chromium, Iron, Lead, Manganese, Mercury, Nickel, Selenium and Zinco. These parameters are also used in the water quality index, with the exception of Selenium. The concentrations were determined through different analytical techniques such as atomic absorption spectrometry (FAAS, GFAAS and CVAAS), optical emission spectrometry (ICP OES) and neutron activation analysis. These analytical methodologies were assessed for precision, accuracy and detection and/or quantification limits for the sediment elements in question. Advantages and disadvantages of each technique for each element and its concentration were also discussed. From these assessments the most adequate technique was selected for the routine analysis of sediment samples for each element concentration determination. This assessment verified also that digestion in a closed microwave system with nitric acid is efficient for the evaluation of extracted metals of environmental interest. The analytical techniques chosen were equally efficient for metals determination. In the case of Cd and Pb, the FAAS technique was selected due to better results than ICP OES, as it does not present matrix interference. The concentration values obtained for metals As, Cd, Cu, Cr, Hg, Ni, Pb and Zn in the sediment samples were compared to Canadian Council of Minister of the Environment (CCME) TEL and PEL values. (author)

  4. Exigências nutricionais de bezerros da raça Holandesa alimentados com concentrado e feno de capim-elefante Nutritional requirements of Holstein calves fed concentrate and elephant grass hay

    Directory of Open Access Journals (Sweden)

    Paulo Valter Nunes Nascimento

    2009-08-01

    Full Text Available Foram utilizados 13 bezerros machos da raça Holandesa, com idade média de 14 dias. Três animais foram abatidos no início do experimento (referência e os outros dez foram distribuídos aleatoriamente em dois tratamentos (ração farelada ou peletizada e abatidos aos 112 dias de idade para determinação das exigências nutricionais. Foram ajustadas equações de regressão do logaritmo da quantidade corporal de proteína, gordura e energia em função do peso de corpo vazio (PCVZ. As exigências líquidas de proteína e energia para ganho de 1 kg de PCVZ foram obtidas por derivação das equações de predição da composição corporal. Os conteúdos de proteína, gordura e energia aumentaram de acordo com o peso corporal. Os requerimentos líquidos de proteína e energia para ganho de peso de corpo vazio (GPCVZ elevaram quando o PCVZ variou de 25,74 até 85,81 kg. Foi obtida a equação para estimar a proteína retida em função do ganho médio diário (GMD e da energia retida (ER: PR = - 0,297083 + 4,19797 ganho de peso corporal em jejum (GPCJ + 0,0926327 ER (R² = 0,92. A equação obtida para descrever a relação entre a energia retida (ER, em Mcal, e o ganho diário de PCVZ (GPCVZ, em kg, para determinado PCVZ a partir dos dados deste trabalho, foi a seguinte: ER = 0,1004 × PCVZ0,75 × GDPCVZ0,5552. Os valores de energia líquida de mantença (ELm variaram de 1,10 para 2,72 Mcal/dia e energia líquida para ganho (ELg de 1,42 para 2,46 Mcal/dia quando o peso corporal aumentou de 30 para 100 kg. Dos 28 aos 112 dias de idade, aumenta a composição de proteína, gordura e energia no corpo vazio de bezerros machos da raça Holandesa.Thirteen male Holstein calves with average age of 14 days were used. Three animals were slaughtered at the beginning of the experiment (reference and ten others were randomly distributed in two treatments (ground or pelleted feed, and slaughtered at 112 days of age to determine the nutritional requirements

  5. Defining the extracellular matrix using proteomics

    Science.gov (United States)

    Byron, Adam; Humphries, Jonathan D; Humphries, Martin J

    2013-01-01

    The cell microenvironment has a profound influence on the behaviour, growth and survival of cells. The extracellular matrix (ECM) provides not only mechanical and structural support to cells and tissues but also binds soluble ligands and transmembrane receptors to provide spatial coordination of signalling processes. The ability of cells to sense the chemical, mechanical and topographical features of the ECM enables them to integrate complex, multiparametric information into a coherent response to the surrounding microenvironment. Consequently, dysregulation or mutation of ECM components results in a broad range of pathological conditions. Characterization of the composition of ECM derived from various cells has begun to reveal insights into ECM structure and function, and mechanisms of disease. Proteomic methodologies permit the global analysis of subcellular systems, but extracellular and transmembrane proteins present analytical difficulties to proteomic strategies owing to the particular biochemical properties of these molecules. Here, we review advances in proteomic approaches that have been applied to furthering our understanding of the ECM microenvironment. We survey recent studies that have addressed challenges in the analysis of ECM and discuss major outcomes in the context of health and disease. In addition, we summarize efforts to progress towards a systems-level understanding of ECM biology. PMID:23419153

  6. Thermoreversible copolymer gels for extracellular matrix.

    Science.gov (United States)

    Vernon, B; Kim, S W; Bae, Y H

    2000-07-01

    To improve the properties of a reversible synthetic extracellular matrix based on a thermally reversible polymer, copolymers of N-isopropylacrylamide and acrylic acid were prepared in benzene with varying contents of acrylic acid (0 to 3%) and the thermal properties were evaluated. The poly(N-isopropylacrylamide) and copolymers made with acrylic acid had molecular weights from 0.8 to 1.7 x10(6) D. Differential scanning calorimetry (DSC) showed the high-molecular-weight acrylic acid copolymers had similar onset temperatures to the homopolymers, but the peak width was considerably increased with increasing acrylic acid content. DSC and cloud point measurements showed that polymers with 0 to 3% acrylic acid exhibit a lower critical solution temperature (LCST) transition between 30 degrees and 37 degrees C. In swelling studies, the homopolymer showed significant syneresis at temperatures above 31 degrees C. Copolymers with 1 and 1.5% showed syneresis beginning at 32 degrees and 37 degrees C, respectively. At 37 degrees C the copolymers with 1.5-3% acrylic acid showed little or no syneresis. Due to the high water content and a transition near physiologic conditions (below 37 degrees C), the polymers with 1.5-2.0% acrylic acid exhibited properties that would be useful in the development of a refillable synthetic extracellular matrix. Such a matrix could be applied to several cell types, including islets of Langerhans, for a biohybrid artificial pancreas.

  7. [Glutamic acid as a universal extracellular signal].

    Science.gov (United States)

    Yoneda, Yukio

    2015-08-01

    The prevailing view is that both glutamic (Glu) and gamma-aminobutyric (GABA) acids play a role as an amino acid neurotransmitter released from neurons. However, little attention has been paid to the possible expression and functionality of signaling machineries required for amino acidergic neurotransmission in cells other than central neurons. In line with our first demonstration of the presence of Glu receptors outside the brain, in this review I will outline our recent findings accumulated since then on the physiological and pathological significance of neuronal amino acids as an extracellular signal essential for homeostasis in a variety of phenotypic cells. In undifferentiated neural progenitor cells, for instance, functional expression is seen with different signaling machineries used for glutamatergic and GABAergic neurotransmission in neurons. Moreover, Glu plays a role in mechanisms underlying suppression of proliferation for self-replication in undifferentiated mesenchymal stem cells. There is more accumulating evidence for neuronal amino acids playing a role as an extracellular autocrine or paracrine signal commonly used in different phenotypic cells. Evaluation of drugs currently used could be thus beneficial for the efficient prophylaxis and/or the therapy of a variety of diseases relevant to disturbance of amino acid signaling in diverse organs.

  8. Extracellular superoxide dismutase of boar seminal plasma.

    Science.gov (United States)

    Kowalowka, M; Wysocki, P; Fraser, L; Strzezek, J

    2008-08-01

    Superoxide dismutase (SOD) is an enzymatic component of the antioxidant defense system that protects spermatozoa by catalysing the dismutation of superoxide anions to hydrogen peroxide and oxygen. Age and season effects on SOD activity in the seminal plasma were measured in boars at the onset of 8 months through a 35-month period. It was found that age-related changes in SOD activity in the seminal plasma were markedly higher in boars less than 2 years of age. However, it appeared that SOD activity was established at the early sexual maturity age (8-12 months). There were variations in SOD activity throughout the season, being significantly higher in spring and autumn than in summer. A secretory extracellular form of SOD (EC-SOD) was purified to homogeneity (350-fold) from boar seminal plasma, using a three-step purification protocol (affinity chromatography followed by ion exchange and ceramic hydroxyapatite chromatography). The molecular properties and specificity of SOD (molecular mass, isoelectric point, optimum pH, thermostability and susceptibility to inhibitors) confirmed that the purified enzyme is an extracellular form of Cu/Zn-superoxide dismutase occurring in boar seminal plasma. The results of this study indicate that EC-SOD is an important antioxidant enzyme of boar seminal plasma, which plays an important physiological role in counteracting oxidative stress in spermatozoa.

  9. Enhancement of extracellular lipid production by oleaginous yeast through preculture and sequencing batch culture strategy with acetic acid.

    Science.gov (United States)

    Huang, Xiang-Feng; Shen, Yi; Luo, Hui-Juan; Liu, Jia-Nan; Liu, Jia

    2017-09-19

    Oleaginous yeast Cryptococcus curvatus MUCL 29819, an acid-tolerant lipid producer, was tested to spill lipids extracellularly using different concentrations of acetic acid as carbon source. Extracellular lipids were released when the yeast was cultured with acetic acid exceeding 20g/L. The highest production of lipid (5.01g/L) was obtained when the yeast was cultured with 40g/L acetic acid. When the yeast was cultivated with moderate concentration (20g/L) of acetic acid, lipid production was further increased by 49.6% through preculture with 40g/L acetic acid as stimulant. When applying high concentration (40g/L) of acetic acid as carbon source in sequencing batch cultivation, extracellular lipids accounted up to 50.5% in the last cycle and the extracellular lipids reached 5.43g/L through the whole process. This study provides an effective strategy to enhance extracellular lipid production and facilitate the recovery of microbial lipids. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Radon and radon daughters' concentration in spring and wells waters from Presidente Prudente: preliminary results; Concentracao de Rn-222 e filhos em aguas provenientes de pocos e emergencias de agua da regiao de Presidente Prudente: resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, Ana Maria Araya; Saenz, Carlos Alberto Tello [Universidade Estadual Paulista Julio de Mesquita Filho (FCT/UNESP), Presidente Prudente, SP (Brazil). Departamento de Fisica Quimica e Biologia; Aguiar, Claudinei Rodrigues de [Universidade Tecnologica Federal do Parana (UTFPR), PR (Brazil); Pereira, Luiz Augusto Stuani [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Presidente Prudente, SP (Brazil)

    2009-07-15

    This work presents the preliminary results about the concentration of radon and radon daughters in wells and springs water from Presidente Prudente. Six water samples were studied: three from well-water, two from springs water and one from potable water. For the determination of α-activity the samples were placed inside plastic containers where the CR-39 tracks detectors were outside the water. The track density of α-particles were measured by using optical microscopy. The results show that one sample from well-water presented higher concentration of radon and radon daughters than the other samples. (author)

  11. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Cecilia Lässer

    2016-12-01

    Full Text Available The International Society for Extracellular Vesicles (ISEV has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs. This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field covering the nomenclature and history of EVs. Module 2 focuses on the biogenesis and uptake mechanisms of EVs, as well as their RNA, protein and lipid cargo. Module 3 covers the collection and processing of cell culture media and body fluids such as blood, breast milk, cerebrospinal fluid and urine prior to isolation of EVs. Modules 4 and 5 present different isolation methods and characterisation techniques utilised in the EV field. Here, differential ultracentrifugation, size-exclusion chromatography, density gradient centrifugation, kit-based precipitation, electron microscopy, cryo-electron microscopy, flow cytometry, atomic-force microscopy and nanoparticle-tracking analysis are covered. This first massive open online course (MOOC on EVs was launched on 15 August 2016 at the platform “Coursera” and is free of charge.

  12. Extracellular matrix in canine mammary tumors with special focus on versican, a versatile extracellular proteoglycan

    NARCIS (Netherlands)

    Erdélyi, Ildikó

    2006-01-01

    The extracellular matrix (ECM) research has become fundamental to understand cancer. This thesis focuses on the exploration of ECM composition and organization in canine mammary tumors, with a special interest in the large chondroitin-sulfate proteoglycan (PG), versican. Chapter 1 gives an overvie

  13. Cloning, Purification, and Characterization of Recombinant Human Extracellular Superoxide Dismutase in SF9 Insect Cells.

    Science.gov (United States)

    Shrestha, Pravesh; Yun, Ji-Hye; Kim, Woo Taek; Kim, Tae-Yoon; Lee, Weontae

    2016-03-01

    A balance between production and degradation of reactive oxygen species (ROS) is critical for maintaining cellular homeostasis. Increased levels of ROS during oxidative stress are associated with disease conditions. Antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD), in the extracellular matrix (ECM) neutralize the toxicity of superoxide. Recent studies have emphasized the importance of EC-SOD in protecting the brain, lungs, and other tissues from oxidative stress. Therefore, EC-SOD would be an excellent therapeutic drug for treatment of diseases caused by oxidative stress. We cloned both the full length (residues 1-240) and truncated (residues 19-240) forms of human EC-SOD (hEC-SOD) into the donor plasmid pFastBacHTb. After transposition, the bacmid was transfected into the Sf9-baculovirus expression system and the expressed hEC-SOD purified using FLAG-tag. Western blot analysis revealed that hEC-SOD is present both as a monomer (33 kDa) and a dimer (66 kDa), as detected by the FLAG antibody. A water-soluble tetrazolium (WST-1) assay showed that both full length and truncated hEC-SOD proteins were enzymatically active. We showed that a potent superoxide dismutase inhibitor, diethyldithiocarbamate (DDC), inhibits hEC-SOD activity.

  14. Novel thermostable glycosidases in the extracellular matrix of the terrestrial cyanobacterium Nostoc commune.

    Science.gov (United States)

    Morsy, Fatthy Mohamed; Kuzuha, Satomi; Takani, Yayoi; Sakamoto, Toshio

    2008-10-01

    The cyanobacterium Nostoc commune is adapted to the terrestrial environment and forms a visible colony in which the cells are embedded in extracellular polysaccharides (EPSs), which play a crucial role in the extreme desiccation tolerance of this organism. When natural colonies were immersed in water, degradation of the colonies occurred within 2 days and N. commune cells were released into the water. The activities that hydrolyze glycoside bonds in various N. commune fractions were examined using artificial nitrophenyl-linked sugars as substrates. A beta-D-glucosidase purified from the water-soluble fraction was resistant to 20 min of boiling. The beta-D-glucosidase, with a molecular mass of 20 kDa, was identified as a cyanobacterial fasciclin protein based on its N-terminal amino-acid sequence. The 36-kDa major protein in the water-soluble fraction was purified, and the N-terminal amino-acid sequence of the protein was found to be identical to that of the water-stress protein (WspA) of N. commune. This WspA protein also showed heat-resistant beta-D-galactosidase activity. The fasciclin protein and WspA in the extracellular matrix may play a role in the hydrolysis of the EPSs surrounding the cells, possibly as an aid in the dispersal of cells, thus expanding the colonies of this cyanobacterium.

  15. Evaluation of radon and their daughters concentration and estimative of effective dose in a waste deposits at the ore treatment unity of INB/Pocos de Caldas, Brazil; Avaliacao da concentracao de radonio e seus filhos e estimativa de dose efetiva em um deposito de rejeitos na unidade de tratamento de minerios da INB/Caldas

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Marcelino V.A.; Garcia Filho, Oswaldo; Antunes, Marcos M.; Junior, Joao V.S.; Py Junior, Delcy A., E-mail: marcelino@inb.gov.b, E-mail: wspereira@inb.gov.b, E-mail: ogarcia@inb.gov.b, E-mail: antunes@inb.gov.b, E-mail: Joao@inb.gov.b, E-mail: delcy@inb.gov.b [Industrias Nucleares do Brasil (UTM/INB), Caldas, MG (Brazil). Unidade de Tratamento de Minerios; Pereira, Wagner S. [Industrias Nucleares do Brasil (UTM/INB), Caldas, MG (Brazil). Unidade de Tratamento de Minerios; Universidade Federal Fluminense (IB/UFF), Niteroi, RJ (Brazil). Inst. de Biologia. Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos

    2011-10-26

    This paper conducts a surveillance of radon and their short half-life daughters gas concentration, inside the warehouse due to these gas inhalation. The results showed that the average concentration inside the warehouse ix approximately 700 Bq/m{sup 3} and the effective dose of an IOE, related to that concentration would be 5.0 mSv/year, therefore being 4 times lower than the established limit of 20 mSv/year

  16. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  17. Degradation of extracellular matrix proteins (fibronectin, vitronectin and laminin) by serine-proteinases isolated from Lonomia achelous caterpillar hemolymph.

    Science.gov (United States)

    Lucena, Sara; Guerrero, Belsy; Salazar, Ana M; Gil, Amparo; Arocha-Piñango, Carmen L

    2006-09-01

    Lonomia achelous is a caterpillar distributed in southern Venezuela and in northern Brazil that causes an acute hemorrhagic syndrome in people who have contact with its bristles. The effect of the crude hemolymph and its chromatographic fractions (FDII, Lonomin V and Lonomin V-2) on extracellular matrix proteins was studied. The chromatographic fractions show activities similar to plasmin and urokinase. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, both lonomins appear as a protein band of 25 kDa under reduced conditions. By exclusion chromatography, the molecular weights of Lonomin V and Lonomin V-2 were 26.5 and 24.5 kDa, respectively. Fibronectin, laminin and vitronectin were degraded by all venom components. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, under reduced conditions, shows that lonomins degrade fibronectin in four main fragments of 116, 60, 50 and 30 kDa. Molecular exclusion chromatography in native conditions shows that the molecular masses of these fragments are > or = 300, 62 and 27 kDa. The proteolytic effect of lonomins was abolished by benzamidine/HCl, iodoacetic acid and aprotinin. The extracellular matrix protein degradation together with the fibrino(geno)lytic activity of hemolymph and its fractions could explain, in part, the hemorrhagic syndrome, and the wound dehiscence in persons who have had contact with the L. achelous caterpillar.

  18. Avaliação da concentração de ferro orgânico em uma população de grávidas An assessment of organic iron concentration in pregnant women

    Directory of Open Access Journals (Sweden)

    Sophia Cornbluth Szarfarc

    1983-06-01

    Full Text Available Objetivou-se conhecer as alterações da concentração de hemoglobina (Hb, hematócrito (Ht, ferro sérico (FS, capacidade total de ligação de ferro (CTLF e saturação de transferrina (ST durante a gestação normal em mulheres não anêmicas (H > 11,0g/dl. Verificou-se, entre as 250 mulheres selecionadas, diminuição dos valores de Hb e Ht até o 7.° mês de gravidez quando houve aumento nesses valores até o final do processo gravídico; o mesmo foi observado com relação aos valores do FS. A CTLF apresentou um aumento durante todo o período considerado enquanto a ST diminuiu. Os resultados observados justificam o uso de suplementação de ferro como uma estratégia de saúde pública a ser utilizada no controle da deficiência de ferro, mesmo entre mulheres não anêmicas.With the aim of discovering the biochemical alterations related to pregnancy and involving iron, the pre-natal case-histories of 250 pregnant women were studied. These women were non-anemic (Hb > 11.0g/dl and free from pathological symptoms, both before and during pregnancy. The factors assessed: hemoglobin (Hb, hematocrite (Ht, serum iron (SI, total iron-binding capacity (TIBC and transferrin saturation (TS were plotted against gestational age, measured in weeks and in months. The Hb and Ht values diminished up to about the 7th month, when they showed an increase which continued up to the end of the pregnancy. The same was observed in relation to SI. The TIBC showed an increase throughout pregnancy while the TS diminished throughout the whole period of gestation. The results observed justify the suggestion of iron supplementation as an easy public health strategy to be applied in the control of iron deficiency, even among non-anemic women.

  19. Effects of extracellular calcium and sodium on depolarization-induced automaticity in guinea pig papillary muscle.

    Science.gov (United States)

    Katzung, B G

    1975-07-01

    Regenerative discharge of action potentials is induced in mammalian papillary muscles by passage of small depolarizing currents. In this paper, the effects of various extracellular calcium and sodium concentrations and of tetrodotoxin on this phenomenon were studied in guinea pig papillary muscles in a sucrose gap chamber. Phase 4 diastolic depolarization was found to be associated with an increase in membrane resistance. The slope of phase 4 depolarization was decreased by reductions in extracellular calcium or sodium concentration. The range of maximum diastolic potentials and the thresholds from which regenerative potentials arose were reduced, especially at the positive limit of potentials, by a reduction in either ion. It was concluded that both calcium and sodium influence diastolic depolarization and participate in the regenerative action potentials of depolarization-induced ventricular automaticity.

  20. Biofouling-Resistant Impedimetric Sensor for Array High-Resolution Extracellular Potassium Monitoring in the Brain

    Directory of Open Access Journals (Sweden)

    Ruben Machado

    2016-10-01

    Full Text Available Extracellular potassium concentration, [K+]o, plays a fundamental role in the physiological functions of the brain. Studies investigating changes in [K+]o have predominantly relied upon glass capillary electrodes with K+-sensitive solution gradients for their measurements. However, such electrodes are unsuitable for taking spatio-temporal measurements and are limited by the surface area of their tips. We illustrate seizures invoked chemically and in optogenetically modified mice using blue light exposure while impedimetrically measuring the response. A sharp decrease of 1–2 mM in [K+]o before each spike has shown new physiological events not witnessed previously when measuring extracellular potassium concentrations during seizures in mice. We propose a novel approach that uses multichannel monolayer coated gold microelectrodes for in vivo spatio-temporal measurements of [K+]o in a mouse brain as an improvement to the conventional glass capillary electrode.

  1. Biofouling-Resistant Impedimetric Sensor for Array High-Resolution Extracellular Potassium Monitoring in the Brain

    Science.gov (United States)

    Machado, Ruben; Soltani, Nima; Dufour, Suzie; Salam, Muhammad Tariqus; Carlen, Peter L.; Genov, Roman; Thompson, Michael

    2016-01-01

    Extracellular potassium concentration, [K+]o, plays a fundamental role in the physiological functions of the brain. Studies investigating changes in [K+]o have predominantly relied upon glass capillary electrodes with K+-sensitive solution gradients for their measurements. However, such electrodes are unsuitable for taking spatio-temporal measurements and are limited by the surface area of their tips. We illustrate seizures invoked chemically and in optogenetically modified mice using blue light exposure while impedimetrically measuring the response. A sharp decrease of 1–2 mM in [K+]o before each spike has shown new physiological events not witnessed previously when measuring extracellular potassium concentrations during seizures in mice. We propose a novel approach that uses multichannel monolayer coated gold microelectrodes for in vivo spatio-temporal measurements of [K+]o in a mouse brain as an improvement to the conventional glass capillary electrode. PMID:27754393

  2. Analysis of hyaluronic acid concentration in rat vocal folds during estral and gravidic puerperal cycles Análise da concentração do ácido hialurônico nas pregas vocais de ratas durante o ciclo estral e ciclo gravídico-puerperal

    Directory of Open Access Journals (Sweden)

    José Eduardo de Sá Pedroso

    2009-10-01

    Full Text Available Hormone plays an important role in the larynx. Among other substances, vocal folds contain hyaluronic acid, which tissue concentration may vary according to hormone action. AIM: the objective of this study is to analyze hyaluronic acid concentration in the vocal folds during estral and gravidic-puerperal cycles. MATERIALS AND METHODS: Experimental study. 40 adult rats were divided into two groups. In the first group we used 20 rats to establish the concentration of hyaluronic acid during the estral cycle and in the second group, 20 animals were submitted to the same procedure but during the gravidic-puerperal cycle. RESULTS: Variations in hyaluronic acid concentration was not observed during the estral cycle. In the gravidic puerperal cycle group, an increase in hyaluronic acid concentration was observed in the puerperal subgroup. Comparing the two groups of estral and gravidic-puerperal cycles, no difference was observed. CONCLUSIONS: In comparing all subgroups of estral and gravidic-puerperal cycles, an increase in hyaluronic acid concentration was noticed only in the puerperal phase.Os hormônios exercem importante influência sobre a laringe. A prega vocal contém, entre outras substâncias, o ácido hialurônico, cuja concentração nos tecidos pode variar com a ação dos hormônios. OBJETIVO: O objetivo deste trabalho é analisar comparativamente a concentração do ácido hialurônico nas pregas vocais de ratas durante o ciclo estral e ciclo gravídico-puerperal. FORMA DE ESTUDO: Experimental. MATERIAL E MÉTODO: Foram utilizadas 40 ratas adultas, divididas em dois grupos, no primeiro grupo utilizamos 20 ratas para determinação da concentração do ácido hialurônico no ciclo estral, no segundo grupo, também de 20 animais, foi realizado o mesmo experimento no ciclo gravídico-puerperal. RESULTADOS: No grupo do ciclo estral não observou-se variação da concentração do ácido hialurônico. No grupo do ciclo grav

  3. Production of an extracellular polyethylene-degrading enzyme(s) by Streptomyces species.

    Science.gov (United States)

    Pometto, A L; Lee, B T; Johnson, K E

    1992-01-01

    Extracellular culture concentrates were prepared from Streptomyces viridosporus T7A, Streptomyces badius 252, and Streptomyces setonii 75Vi2 shake flask cultures. Ten-day-heat-treated (70 degrees C) starch-polyethylene degradable plastic films were incubated with shaking with active or inactive enzyme for 3 weeks (37 degrees C). Active enzyme illustrated changes in the films' Fourier transform infrared spectra, mechanical properties, and polyethylene molecular weight distributions. PMID:1610196

  4. Lung protection by inhalation of exogenous solubilized extracellular matrix

    Science.gov (United States)

    Wu, Jinglei; Ravikumar, Priya; Nguyen, Kytai T.; Hsia, Connie C. W.

    2017-01-01

    Decellularized extracellular matrix (ECM) contains complex tissue-specific components that work in concert to promote tissue repair and constructive remodeling and has been used experimentally and clinically to accelerate epithelial wound repair, leading us to hypothesize that lung-derived ECM could mitigate acute lung injury. To explore the therapeutic potential of ECM for noninvasive delivery to the lung, we decellularized and solubilized porcine lung ECM, then characterized the composition, concentration, particle size and stability of the preparation. The ECM preparation at 3.2 mg/mL with average particle size <3 μm was tested in vitro on human A549 lung epithelial cells exposed to 95% O2 for 24 hours, and in vivo by tracheal instillation or nebulization into the lungs of rats exposed intermittently or continuously to 90% O2 for a cumulative 72 hours. Our results showed that the preparation was enriched in collagen, reduced in glycosaminoglycans, and contained various bioactive molecules. Particle size was concentration-dependent. Compared to the respective controls treated with cell culture medium in vitro or saline in vivo, ECM inhalation normalized cell survival and alveolar morphology, and reduced hyperoxia-induced apoptosis and oxidative damage. This proof-of-concept study established the methodology, feasibility and therapeutic potential of exogenous solubilized ECM for pulmonary cytoprotection, possibly as an adjunct or potentiator of conventional therapy. PMID:28151947

  5. Concentrações séricas de proteína total, albumina e gamaglobulinas em gatos infectados pelo vírus da imunodeficiência felina Serum protein, albumin and gamaglobulin concentrations in cats infected with feline immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Angela Manetti Armentano Rodrigues

    2007-02-01

    Full Text Available A infecção pelo vírus da imunodeficiência dos felinos (VIF apresenta um curso prolongado, caracterizado por uma fase aguda, em que ocorre a replicação viral no organismo hospedeiro, seguida de um período de menor replicação, no qual o animal é praticamente assintomático. Anos depois, no estádio final da infecção, desenvolve-se a síndrome da imunodeficiência dos felinos. Alguns animais infectados podem desenvolver hipergamaglobulinemia do tipo policlonal, principalmente na fase crônica ou final da infecção. Este fato tem sido atribuído a um distúrbio na produção de citocinas, causado pela infecção viral de linfócitos T CD4+. Não obstante, pouco se sabe a respeito das concentrações de proteínas séricas, especificamente gamaglobulinas, na fase aguda da infecção pelo VIF. Objetivando esclarecer isto, procedeu-se à determinação das proteínas séricas de dez felinos, SRD de ambos os sexos, infectados aos 7 meses de idade com o VIF (clade B, antes da infecção e 4, 8 e 12 meses após. A infecção pelo VIF foi confirmada pela soroconversão, com a presença de anticorpos específicos, pesquisados por meio da técnica de imunoadsorção enzimática (ELISA e pela demonstração de material genético do vírus (PCR. Outros dez felinos VIF-, da mesma faixa etária foram mantidos como controle. Previamente à infecção experimental, todos os felinos eram negativos ao VIF, fato comprovado pela ausência de anticorpos específicos. A proteína sérica total foi determinada pelo método do buireto e as frações protéicas foram obtidas por eletroforese em tiras de acetato de celulose lidas por densitometria. Verificou-se aumento de gamaglobulinas (2,01 ±0,27g dL-1, PFeline immunodeficiency virus (FIV infection is known as a lifelong infection of cats. The acute phase corresponds to the period of viral replication in the host organism, followed by a period of lower replication when the animal is asymptomatic. Some years

  6. Desidratação osmótica de pêssegos em função da temperatura e concentração do xarope de sacarose Osmotic dehydration of peaches as a function of temperature and concentration of sucrose syrup

    Directory of Open Access Journals (Sweden)

    Sílvia P. M Germer

    2011-02-01

    Full Text Available A desidratação osmótica pela qual passa a produção de fruta, é uma alternativa para o aproveitamento dos excedentes da persicultura. Neste trabalho se avaliou a influência da temperatura e da concentração do xarope de sacarose na desidratação osmótica de pêssegos, e se investigaram variações de propriedades físicas, químicas e dos parâmetros da desidratação osmótica (perda de massa e de água; incorporação de sólidos. O delineamento central composto rotacional foi utilizado variando-se a temperatura (30 a 50 ºC e a concentração (45 a 65 °Brix da solução osmótica e se fixando a razão mássica xarope:fruta 4:1, tempo de processo 4 h, e formato dos pedaços (metades. Na análise sensorial empregou-se o método de aceitação avaliando-se os atributos aparência, sabor, textura, cor e qualidade geral. Modelaram-se os resultados com o programa Statistica (v 6.0, através da Metodologia de Superfície de Resposta. Os seguintes modelos matemáticos resultaram significativos (p The production of dried peach by osmotic dehydration is an alternative for using the excess of peach production. The influence of the temperature and concentration of the sucrose syrup in osmotic dehydration of peaches was evaluated. Variations in physical and chemical properties, and osmotic dehydration parameters (weight loss and water loss; solids incorporation were investigated. An experimental central composite design was employed ranging the temperature (30 to 50 ºC and concentration (45 to 65 °Brix, keeping the syrup:fruit mass ratio 4:1, process time 4 h, and format pieces (halves. The degree of acceptance was used in the sensory analysis, evaluating the following characteristics: appearance, taste, texture, colour and overall quality. The results were modelled using the Statistica program (v. 6.0 employing the Response Surface Methodology. The following mathematical models resulted significant (p < 0.05 and predictive: dimensionless

  7. Características da Carcaça de Bezerros Holandeses para Produção de Vitelos Recebendo Dietas com Diferentes Níveis de Concentrado Carcass Characteristics of Holstein Veal Calves Fed Diets with Different Levels of Concentrate

    Directory of Open Access Journals (Sweden)

    Telma Regina Ribeiro

    2001-12-01

    Full Text Available O experimento foi realizado utilizando 20 bezerros da raça Holandesa, machos não castrados, com o objetivo de avaliar as características das carcaças desses animais alimentados com dietas contendo 45, 60, 75 e 90% de concentrado. As dietas foram constituídas de feno de capim-coastcross, fubá de milho, farelo de soja e mistura mineral, fornecidas à vontade. O delineamento experimental foi em blocos casualizados, com quatro tratamentos e cinco repetições. Antes do início do experimento, todos os animais foram submetidos a um mesmo sistema de aleitamento. O período experimental foi variável para cada tratamento, em que os animais eram abatidos, após jejum de 16 horas, à medida que atingiam o peso vivo médio de 200 kg. Nas meias carcaças esquerdas foram medidas a área de olho de lombo, o comprimento da carcaça e a sua composição física, enquanto nas meias carcaças direitas foram feitos os cortes básicos da carcaça. O rendimento das carcaças quente e fria com base no peso vivo dos animais, o rendimento da carcaça quente com base no peso corporal vazio e a área de olho de lombo dos animais apresentaram diferenças significativas com o acréscimo de concentrado nas dietas. Não houve diferenças significativas para peso vivo final, peso da carcaça quente, pesoda carcaça fria e rendimento da carcaça fria com base no peso corporal vazio, assim como nas perdas de peso nas carcaças ocasionadas pelo tempo de jejum ao qual os animais foram submetidos antes do abate, nos cortes básicos e no rendimento do dianteiro e traseiro nas carcaças.The experiment was carried out with 20 Holstein intact male calves to study the carcass characteristics of these animals fed with diets containing 45, 60, 75 and 90% of concentrate. Diets were composed of coastcross hay, ground corn grain, soybean meal and mineral mixture fed ad libitum. A completely randomized blocks experimental design, with four treatments and five replications, was used

  8. Extracellular Ca(2+)-dependent enhancement of cytocidal potency of zoledronic acid in human oral cancer cells.

    Science.gov (United States)

    Inoue, Sayaka; Arai, Naoya; Tomihara, Kei; Takashina, Michinori; Hattori, Yuichi; Noguchi, Makoto

    2015-08-15

    Direct antitumor effects of bisphosphonates (BPs) have been demonstrated in various cancer cells in vitro. However, the effective concentrations of BPs are typically much higher than their clinically relevant concentrations. Oral cancers frequently invade jawbone and may lead to the release of Ca(2+) in primary lesions. We investigated the effects of the combined application of zoledronic acid (ZA) and Ca(2+) on proliferation and apoptosis of oral cancer cells. Human oral cancer cells, breast cancer cells, and colon cancer cells were treated with ZA at a wide range of concentrations in different Ca(2+) concentration environments. Under a standard Ca(2+) concentration (0.6mM), micromolar concentrations of ZA were required to inhibit oral cancer cell proliferation. Increasing extracellular Ca(2+) concentrations greatly enhanced the potency of the ZA cytocidal effect. The ability of Ca(2+) to enhance the cytocidal effects of ZA was negated by the Ca(2+)-selective chelator EGTA. In contrast, the cytocidal effect of ZA was less pronounced in breast and colon cancer cells regardless of whether extracellular Ca(2+) was elevated. In oral cancer cells incubated with 1.6mM Ca(2+), ZA up-regulated mitochondrial Bax expression and increased mitochondrial Ca(2+) uptake. This was associated with decreased mitochondrial membrane potential and increased release of cytochrome c. We suggest that ZA can specifically produce potent cytocidal activity in oral cancer cells in an extracellular Ca(2+)-dependent manner, implying that BPs may be useful for treatment of oral squamous cell carcinoma with jawbone invasion leading to the hypercalcemic state.

  9. Extracellular RNAs: development as biomarkers of human disease

    Directory of Open Access Journals (Sweden)

    Joseph F. Quinn

    2015-08-01

    Full Text Available Ten ongoing studies designed to test the possibility that extracellular RNAs may serve as biomarkers in human disease are described. These studies, funded by the NIH Common Fund Extracellular RNA Communication Program, examine diverse extracellular body fluids, including plasma, serum, urine and cerebrospinal fluid. The disorders studied include hepatic and gastric cancer, cardiovascular disease, chronic kidney disease, neurodegenerative disease, brain tumours, intracranial haemorrhage, multiple sclerosis and placental disorders. Progress to date and the plans for future studies are outlined.

  10. Neutrophils cast extracellular traps in response to protozoan parasites.

    Science.gov (United States)

    Abi Abdallah, Delbert S; Denkers, Eric Y

    2012-01-01

    Release of extracellular traps by neutrophils is a now well-established phenomenon that contributes to the innate response to extracellular bacterial and fungal pathogens. The importance of NETs during protozoan infection has been less explored, but recent findings suggest an emerging role for release of neutrophil-derived extracellular DNA in response to this class of microbial pathogens. The present review summarizes findings to date regarding elicitation of NETs by Toxoplasma gondii, Plasmodium falciparum, Eimeria bovis, and Leishmania spp.

  11. CUMS抑郁模型大鼠脑组织DA、5-HT及其代谢产物的浓度变化%Concentration change of DA, 5-HT and their metabolites in brain tissue of depression models rat treated with chronic unpredicted mild stress

    Institute of Scientific and Technical Information of China (English)

    唐亚梅; 陈春梅; 刘勇

    2012-01-01

    Objective We explored the related neurobiochemistry pathomechanism by the comparison of concentration of dopamine(DA), 5-hydroxytryptamine (5-HT) and their metabolites in brain tissue in the Chronic unpredicted mild stress (CUMS)depression model rats. Methods 24 male Spragur-Dawley (SD) rats were randomly assigned to 3 groups: control group, model group and fluoxetine group. CUMS with solitary condition was taken to manufacture depression rat model. After separated the brains tissues of CUMS depression rats, the levels of DA, 5-HT and their metabolites of the tissue homogenate from the medial prefrontal cortex (mPFC) and hippocampus were examined with Coularray Electrochemic detection for high performance liquid chromatogram (HPLC) technique. Results Compared to contronl group, the levels of DA, homovanillic acid (HVA), 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in the mPFC of depression model rats have significantly decreased(P<0.01 or 0.05), and the levels of DA, HVA and 5-HT in hippocampus have significantly decreased (P<0.01 or 0.05); Compared to model group, the levels of DA, HVA and 5 -HT in the mPFC of fluoxetine group rats have significantly increased (P<0.01 or 0.05), and the levels of DA, 5 -HT and 5 -HIAA in hippocampus have significantly increased (P <0.05). Conclusion The activity of DA and 5 -HT systems in the mPFC and hippocampus were decreased in CUMS depression model rats.%目的:通过分析抑郁模型大鼠脑组织DA、5-HT及其代谢产物的浓度变化,探讨抑郁症发病的神经生化机制.方法:将24只雄性SD大鼠随机分成对照组、模型组和氟西汀组3组;采用慢性轻度不可预见性应激(CUMS)结合孤养建立抑郁大鼠模型,随后取脑并分离内侧前额皮质(mPFC)和海马,采用库仑阵列电化学高效液相色谱法测定上述脑区DA、5-HT及其代谢产物的浓度.结果:与对照组比较,模型组大鼠mPFC区DA、高香草酸(HVA)、5-HT及5-羟吲哚乙酸(5-HIAA

  12. A model of extracellular enzymes in free-living microbes: which strategy pays off?

    Science.gov (United States)

    Traving, Sachia J; Thygesen, Uffe H; Riemann, Lasse; Stedmon, Colin A

    2015-11-01

    An initial modeling approach was applied to analyze how a single, nonmotile, free-living, heterotrophic bacterial cell may optimize the deployment of its extracellular enzymes. Free-living cells live in a dilute and complex substrate field, and to gain enough substrate, their extracellular enzymes must be utilized efficiently. The model revealed that surface-attached and free enzymes generate unique enzyme and substrate fields, and each deployment strategy has distinctive advantages. For a solitary cell, surface-attached enzymes are suggested to be the most cost-efficient strategy. This strategy entails potential substrates being reduced to very low concentrations. Free enzymes, on the other hand, generate a radically different substrate field, which suggests significant benefits for the strategy if free cells engage in social foraging or experience high substrate concentrations. Swimming has a slight positive effect for the attached-enzyme strategy, while the effect is negative for the free-enzyme strategy. The results of this study suggest that specific dissolved organic compounds in the ocean likely persist below a threshold concentration impervious to biological utilization. This could help explain the persistence and apparent refractory state of oceanic dissolved organic matter (DOM). Microbial extracellular enzyme strategies, therefore, have important implications for larger-scale processes, such as shaping the role of DOM in ocean carbon sequestration.

  13. A Model of Extracellular Enzymes in Free-Living Microbes: Which Strategy Pays Off?

    Science.gov (United States)

    Thygesen, Uffe H.; Riemann, Lasse; Stedmon, Colin A.

    2015-01-01

    An initial modeling approach was applied to analyze how a single, nonmotile, free-living, heterotrophic bacterial cell may optimize the deployment of its extracellular enzymes. Free-living cells live in a dilute and complex substrate field, and to gain enough substrate, their extracellular enzymes must be utilized efficiently. The model revealed that surface-attached and free enzymes generate unique enzyme and substrate fields, and each deployment strategy has distinctive advantages. For a solitary cell, surface-attached enzymes are suggested to be the most cost-efficient strategy. This strategy entails potential substrates being reduced to very low concentrations. Free enzymes, on the other hand, generate a radically different substrate field, which suggests significant benefits for the strategy if free cells engage in social foraging or experience high substrate concentrations. Swimming has a slight positive effect for the attached-enzyme strategy, while the effect is negative for the free-enzyme strategy. The results of this study suggest that specific dissolved organic compounds in the ocean likely persist below a threshold concentration impervious to biological utilization. This could help explain the persistence and apparent refractory state of oceanic dissolved organic matter (DOM). Microbial extracellular enzyme strategies, therefore, have important implications for larger-scale processes, such as shaping the role of DOM in ocean carbon sequestration. PMID:26253668

  14. Metals on urban soils: evaluation of the concentration on soils adjacent to the Pinheiros river border avenues; Metais em solos urbanos: avaliacao da concentracao em solos adjacentes a marginal do rio Pinheiros, SP

    Energy Technology Data Exchange (ETDEWEB)

    Nammoura Neto, Georges M.; Figueiredo, Ana M.G.; Ribeiro, Andreza P.; Silva, Natalia C.; Ticianelli, Regina B.; Camargo, Sonia P., E-mail: anamaria@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2009-07-01

    The samples for this study were collected in seven points with approximately 3 km of distance, with a depth of 5 cm and prepared in laboratory. Also, with the samples three BEN (IWG-GIT), GS-N (IWG-GIT) and Soil-7 (IAEA) reference standards were analysed,for quality control of the results. Using neutron activation analysis it was possible to determine the concentrations of these heavy metal, particularly the zinc and the barium, and in these study, these two metals have their concentrations rose surpassing the intervention limits, according to the stipulated by the Companhia de Tecnologia de Saneamento Ambiental (CETESB), which can be connected to vehicle emissions and the use of pesticides and herbicides as long as his extension, being considered a risk for the human heath through the resuspension the dust of these contaminated soil

  15. Effect of acupuncture on TNF-alpha, IL-1b and IL-10 concentrations in the peritoneal exudates of carrageenan-induced peritonitis in rats Efeito da acupuntura sobre a concentração de TNF-alfa, IL-1b e IL-10 no exsudato peritoneal de ratos com peritonite induzida por carragenina

    Directory of Open Access Journals (Sweden)

    Márcia Valéria Rizzo Scognamillo-Szabó

    2005-02-01

    Full Text Available Acupuncture is an ancient and empirical therapeutic procedure known by its efficacy in the treatment of pain. However, the influence of acupuncture on inflammatory process is still poorly understood and additional research is needed. In this work, we investigated the mechanism of action of manual acupuncture on the inhibition of neutrophil migration to the peritoneal cavity induced by the inflammatory stimulus carrageenan in Wistar rats. Previous results from our laboratory showed that this anti-inflammatory effect is not due to endogenous corticoid release. Furthermore, the concentration of IL-1b, but not of TNF-alpha or IL-10 in the carrageenan-induced exudates was reduced in the acupuncture group. Further research will be needed to elucidate the mechanisms involved in the anti-inflammatory action of acupuncture as described here.A acupuntura é método terapêutico milenar reconhecido por sua eficácia no tratamento da dor, porém seu efeito sobre processos inflamatórios é ainda pouco conhecido e maiores estudos são necessários. Neste trabalho, é investigado o mecanismo de ação da acupuntura manual sobre a inibição na migração de neutrófilos para a cavidade peritoneal induzida por carragenina em ratos Wistar. Resultados prévios indicam que esse efeito antiinflamatório não depende de hormônios corticóides. Entretanto, as concentrações de IL-1b no exsudato induzido por carragenina foram reduzidas pelo tratamento com acupuntura. Por outro lado os níveis de TNF-alfa e IL-10 não foram afetados pelo tratamento. Mais pesquisas poderão elucidar os mecanismos envolvidos na ação antiinflamatória da acupuntura.

  16. Effect of the polypropylene concentration on the structure and properties of compounds with poly(hydroxymethylacrylamide); Efeito da concentracao de polipropileno sobre a estrutura e propriedades de compostos com poli(hidroximetilacrilamida)

    Energy Technology Data Exchange (ETDEWEB)

    Cirne, I.V.; Esperidiao, D.M.C.A., E-mail: mcecilia@ufba.b [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica; Watanabe, G.T. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Dept. de Engenharia Quimica; Lucas, E.F. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano; Ferreira, S.C. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

    2010-07-01

    The oily wastewater from petroleum industry has micro-emulsified oil in concentration around 1000 ppm. This oil can be efficiently removed by using adsorption processes. In this work the effect of the polypropylene, PP, concentration on the structure and properties of their compounds with poly(hydroxymethylacrylamide), PHMAA, were investigated for analyze its possible use as adsorbent. The apparent density, d{sub a}, swelling degree, Xi and crosslink density, X{sub c}, were determined. The FTIR, DSC, TGA, DRX and optical microscopy analyses were made. The d{sub a} and X{sub c} values decrease when the PP concentration increases. The Xi was equal to 1.3, 1.8 e 2.0 for compounds with 65, 70 e 79% of PP, respectively. The PP-PHMAA compounds have lesser temperature and melting enthalpy than the PP. The crystalline structure of the PP chains in PP-PHMAA was modified evidencing physic interactions between PP and PHMAA chains. (author)

  17. Neutron activation analysis application for determining iron concentration in forage grasses used in intensive cattle production system; Aplicacao da analise por ativacao com neutrons para determinacao de ferro em forrageiras usadas no sistema intensivo de producao de bovinos de leite

    Energy Technology Data Exchange (ETDEWEB)

    Armelin, Maria Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Primavesi, Odo [Empresa Brasileira de Pesquisa Agropecuaria, Sao Carlos, SP (Brazil). Centro de Pesquisa de Pecuaria do Sudeste

    2002-07-01

    Iron is an essential element to the life. It is an important hemoglobin component and it is involved in the transport of oxygen to cells. A deficiency of iron results in an unsuitable synthesis of hemoglobin and a delay in the growth. Iron contents above the tolerable level in animal feed can cause serious damages to the health and the death in extreme cases. The forages are the main source of feed to cattle in grazing. It is known from the literature, that the growth and the nutritious value of the forage are influenced by specie and physiologic age of the plant, soil fertility and environmental conditions. Therefore, an agronomical evaluations of the forages are necessary before to introduce in an intensive cattle production systems to program adequate grazing management. Neutron activation analysis was applied to evaluate the Fe concentration in the main tropical forage grasses used in intensive dairy cattle production systems in Sao Carlos, SP, Brazil. Iron concentrations were smaller in the rain season than in the dry one. Comparison of results obtained in the analyses of forages with daily requirements of iron in dry matter, showed that the Fe concentration in forages was adequate. (author)

  18. Avaliação da concentração de retinol em leite UHT ("Ultra High Temperature" comercializado em Natal, Rio Grande do Norte Evaluation of the retinol concentration in UHT milk commercialized in Natal, RN

    Directory of Open Access Journals (Sweden)

    Fernanda Barros Soares

    2008-01-01

    Full Text Available Deficiency of micronutrients is a public health problem. Cow milk is a source of retinol. The objective of this study is to evaluate the retinol concentration in milk commercialized in Natal/RN. Ten samples were taken of each brand of UHT milk. Vitamin content was determined by HPLC using the Shimadzu LC-10 AD Chromatograph, coupled to the Shimadzu SPD 10 A UV-VIS Detector and the Shimadzu C-R6A Chromatopac Integrator with Shim-pack CLC-ODS (M column, measuring 4.6 mm x 25 cm. The mobile phase was 100% methanol, with a flow of 1 mL/min. The mean retinol concentration varied between 22.7 ± 4.9 µg/100 mL and 44.1 ± 4.1 µg/100 mL, with the differences statistically significant (p<0.001. Only one of the 7 brands had retinol concentration below the normal requirements for human consumption.

  19. Carbenoxolone inhibits Pannexin1 channels through interactions in the first extracellular loop.

    Science.gov (United States)

    Michalski, Kevin; Kawate, Toshimitsu

    2016-02-01

    Pannexin1 (Panx1) is an ATP release channel important for controlling immune responses and synaptic strength. Various stimuli including C-terminal cleavage, a high concentration of extracellular potassium, and voltage have been demonstrated to activate Panx1. However, it remains unclear how Panx1 senses and integrates such diverse stimuli to form an open channel. To provide a clue on the mechanism underlying Panx1 channel gating, we investigated the action mechanism of carbenoxolone (CBX), the most commonly used small molecule for attenuating Panx1 function triggered by a wide range of stimuli. Using a chimeric approach, we discovered that CBX reverses its action polarity and potentiates the voltage-gated channel activity of Panx1 when W74 in the first extracellular loop is mutated to a nonaromatic residue. A systematic mutagenesis study revealed that conserved residues in this loop also play important roles in CBX function, potentially by mediating CBX binding. We extended our experiments to other Panx1 inhibitors such as probenecid and ATP, which also potentiate the voltage-gated channel activity of a Panx1 mutant at position 74. Notably, probenecid alone can activate this mutant at a resting membrane potential. These data suggest that CBX and other inhibitors, including probenecid, attenuate Panx1 channel activity through modulation of the first extracellular loop. Our experiments are the first step toward identifying a previously unknown mode of CBX action, which provide insight into the role of the first extracellular loop in Panx1 channel gating.

  20. Evidences of Hfq associates with tryptophanase and affects extracellular indole levels

    Institute of Scientific and Technical Information of China (English)

    Yinghua Zhang; Guofan Hong

    2009-01-01

    In this study, we observed a novel property of Escherichia coil Hfq protein: it possibly influenced extracellular indole levels. The extracellular indole concentrations were increased in Hfq mutant cells and decreased in Hfq overexpression cells in a cell density-dependent manner. The decreased extracellular indole levels in Hfq overexpression cells caused the postpone-ment of entering into stationary phase, lndole was pro-duced by tryptophanase, the gene product of tnaA, which catalyzed tryptophan into indole, ammonia and pyruvate. Further studies showed that at cell density of 0.8 but not at 0.4, tryptophanase activities of total cell extracts were affected by Hfq mutation or overexpression. Protein pull-down assay and co-immunoprecipitation experiments revealed that Hfq associated with trypto-phanase under relatively higher extracellular indole levels, suggesting this was a feedback control of indole production. The association of Hfq and tryptophanase might be indirect because purified Hfq could not affect the values of Km and Vmax of purified tryptophanase.

  1. Evidences of Hfq associates with tryptophanase and affects extracellular indole levels.

    Science.gov (United States)

    Zhang, Yinghua; Hong, Guofan

    2009-08-01

    In this study, we observed a novel property of Escherichia coli Hfq protein: it possibly influenced extracellular indole levels. The extracellular indole concentrations were increased in Hfq mutant cells and decreased in Hfq overexpression cells in a cell density-dependent manner. The decreased extracellular indole levels in Hfq overexpression cells caused the postponement of entering into stationary phase. Indole was produced by tryptophanase, the gene product of tnaA, which catalyzed tryptophan into indole, ammonia and pyruvate. Further studies showed that at cell density of 0.8 but not at 0.4, tryptophanase activities of total cell extracts were affected by Hfq mutation or overexpression. Protein pull-down assay and co-immunoprecipitation experiments revealed that Hfq associated with tryptophanase under relatively higher extracellular indole levels, suggesting this was a feedback control of indole production. The association of Hfq and tryptophanase might be indirect because purified Hfq could not affect the values of Km and Vmax of purified tryptophanase.

  2. The NIH Extracellular RNA Communication Consortium.

    Science.gov (United States)

    Ainsztein, Alexandra M; Brooks, Philip J; Dugan, Vivien G; Ganguly, Aniruddha; Guo, Max; Howcroft, T Kevin; Kelley, Christine A; Kuo, Lillian S; Labosky, Patricia A; Lenzi, Rebecca; McKie, George A; Mohla, Suresh; Procaccini, Dena; Reilly, Matthew; Satterlee, John S; Srinivas, Pothur R; Church, Elizabeth Stansell; Sutherland, Margaret; Tagle, Danilo A; Tucker, Jessica M; Venkatachalam, Sundar

    2015-01-01

    The Extracellular RNA (exRNA) Communication Consortium, funded as an initiative of the NIH Common Fund, represents a consortium of investigators assembled to address the critical issues in the exRNA research arena. The overarching goal is to generate a multi-component community resource for sharing fundamental scientific discoveries, protocols, and innovative tools and technologies. The key initiatives include (a) generating a reference catalogue of exRNAs present in body fluids of normal healthy individuals that would facilitate disease diagnosis and therapies, (b) defining the fundamental principles of exRNA biogenesis, distribution, uptake, and function, as well as development of molecular tools, technologies, and imaging modalities to enable these studies,

  3. Physiology and pathology of extracellular vesicules

    Directory of Open Access Journals (Sweden)

    M. A. Panteleev

    2017-01-01

    Full Text Available This year marks the 50th anniversary of the first publication about blood plasma microparticles. Initially considered as cell fragments or “platelet dust”, extracellular vesicles currently attracted the attention of biochemists, biophysicists, physicians, pharmacists around the world. They are heterogeneous in structure and derived from many cell types, express different antigen and contain variety of biomolecules that determines wide range of biological activity, including procoagulant, regenerative, immunomodulating, and others. They play an important role in the pathophysiology of different diseases and conditions – from infarction, injuries and pregnancies to the “graft versus host” disease. The vesicles as medicaments and their carriers, as well as the drugs that affect them, are a rapidly developing field of research.

  4. Extracellular Matrices (ECM) for Tissue Repair.

    Science.gov (United States)

    Polanco, Thais O; Xylas, Joanna; Lantis, John C

    2016-04-01

    Persistence of skin wounds due to underlying disease, bacterial contamination, and/or repeated trauma, causes a chronic condition where a functional extracellular matrix (ECM) cannot be established and the normal wound-healing cascade is unable to progress. These open chronic wounds leave the body susceptible to infection and present a major healthcare problem. To this end, a broad range of biologic ECM scaffolds have been developed that can provide other therapeutic options aside from traditional wound care approaches. These tissue engineered ECM scaffolds aim to facilitate the restoration of functional skin-like tissue by altering the chronic wound environment and facilitating cellular attachment, proliferation, and differentiation. This discussion will center on reviewing current ECM scaffolds and highlighting their properties and mechanism of action with respect to the clinical application in chronic, non-healing wounds.

  5. Neutrophil extracellular traps in tissue pathology.

    Science.gov (United States)

    Nakazawa, Daigo; Kumar, Santosh; Desai, Jyaysi; Anders, Hans-Joachim

    2017-03-01

    Neutrophil extracellular traps (NETs) are innate immune systems against invading pathogens. NETs are characterized as released DNA mixed with cytoplasmic antimicrobial proteins such as myeloperoxidase, proteinase3 and neutrophil elastase. While NETs are thought to have an important role in host defense, recent work has suggested that NETs contribute to tissue injury in non-infectious disease states. Uncontrolled NET formation in autoimmune diseases, metabolic disorders, cancers and thrombotic diseases can exacerbate a disease or even be a major initiator of tissue injury. But spotting NETs in tissues is not easy. Here we review the available histopathological evidence on the presence of NETs in a variety of diseases. We discuss technical difficulties and potential sources of misinterpretation while trying to detect NETs in tissue samples.

  6. Extracellular nicotinamide phosphoribosyltransferase, a new cancer metabokine

    Science.gov (United States)

    Grolla, Ambra A; Travelli, Cristina

    2016-01-01

    Abstract In this review, we focus on the secreted form of nicotinamide phosphoribosyltransferase (NAMPT); extracellular NAMPT (eNAMPT), also known as pre‐B cell colony‐enhancing factor or visfatin. Although intracellular NAMPT is a key enzyme in controlling NAD metabolism, eNAMPT has been reported to function as a cytokine, with many roles in physiology and pathology. Circulating eNAMPT has been associated with several metabolic and inflammatory disorders, including cancer. Because cytokines produced in the tumour micro‐environment play an important role in cancer pathogenesis, in part by reprogramming cellular metabolism, future improvements in cancer immunotherapy will require a better understanding of the crosstalk between cytokine action and tumour biology. In this review, the knowledge of eNAMPT in cancer will be discussed, focusing on its immunometabolic function as a metabokine, its secretion, its mechanism of action and possible roles in the cancer micro‐environment. PMID:27128025

  7. Extracellular Vesicles in Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Tsukasa Kadota

    2016-10-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is characterized by the progression of irreversible airflow limitation and is a leading cause of morbidity and mortality worldwide. Although several crucial mechanisms of COPD pathogenesis have been studied, the precise mechanism remains unknown. Extracellular vesicles (EVs, including exosomes, microvesicles, and apoptotic bodies, are released from almost all cell types and are recognized as novel cell–cell communication tools. They have been shown to carry and transfer a wide variety of molecules, such as microRNAs, messenger RNAs, and proteins, which are involved in physiological functions and the pathology of various diseases. Recently, EVs have attracted considerable attention in pulmonary research. In this review, we summarize the recent findings of EV-mediated COPD pathogenesis. We also discuss the potential clinical usefulness of EVs as biomarkers and therapeutic agents for the treatment of COPD.

  8. Extracellular Matrix Molecules Facilitating Vascular Biointegration

    Directory of Open Access Journals (Sweden)

    Martin K.C. Ng

    2012-08-01

    Full Text Available All vascular implants, including stents, heart valves and graft materials exhibit suboptimal biocompatibility that significantly reduces their clinical efficacy. A range of biomolecules in the subendothelial space have been shown to play critical roles in local regulation of thrombosis, endothelial growth and smooth muscle cell proliferation, making these attractive candidates for modulation of vascular device biointegration. However, classically used biomaterial coatings, such as fibronectin and laminin, modulate only one of these components; enhancing endothelial cell attachment, but also activating platelets and triggering thrombosis. This review examines a subset of extracellular matrix molecules that have demonstrated multi-faceted vascular compatibility and accordingly are promising candidates to improve the biointegration of vascular biomaterials.

  9. Active endocannabinoids are secreted on extracellular membrane vesicles.

    Science.gov (United States)

    Gabrielli, Martina; Battista, Natalia; Riganti, Loredana; Prada, Ilaria; Antonucci, Flavia; Cantone, Laura; Matteoli, Michela; Maccarrone, Mauro; Verderio, Claudia

    2015-02-01

    Endocannabinoids primarily influence neuronal synaptic communication within the nervous system. To exert their function, endocannabinoids need to travel across the intercellular space. However, how hydrophobic endocannabinoids cross cell membranes and move extracellularly remains an unresolved problem. Here, we show that endocannabinoids are secreted through extracellular membrane vesicles produced by microglial cells. We demonstrate that microglial extracellular vesicles carry on their surface N-arachidonoylethanolamine (AEA), which is able to stimulate type-1 cannabinoid receptors (CB1), and inhibit presynaptic transmission, in target GABAergic neurons. This is the first demonstration of a functional role of extracellular vesicular transport of endocannabinoids.

  10. On the chemical dynamics of extracellular polysaccharides in the high Arctic surface microlayer

    Directory of Open Access Journals (Sweden)

    Q. Gao

    2012-07-01

    Full Text Available The surface microlayer (SML represents a unique system of which the physicochemical characteristics may differ from those of the underlying subsurface seawater (SSW. Within the Arctic pack ice area, the SML has been characterized as enriched in small colloids of biological origin, resulting from extracellular polymeric secretions (EPS. During the Arctic Summer Cloud Ocean Study (ASCOS in August 2008, particulate organic matter (POM, with size range > 0.22 μm and dissolved organic matter (DOM, < 0.22 μm, obtained after filtration samples were collected and chemically characterized from the SML and the corresponding SSW at an open lead centered at 87.5° N and 5° E. Total organic carbon was persistently enriched in the SML with a mean enrichment factor (EF of 1.45 ± 0.41, whereas sporadic depletions of dissolved carbohydrates and amino acids were observed. Monosaccharide compositional analysis reveals that EPS in the Arctic lead was formed mainly of distinctive heteropolysaccharides, enriched in xylose, fucose and glucose. The mean concentrations of total hydrolysable neutral sugars in SSW were 94.9 ± 37.5 nM in high molecular weight (HMW DOM (> 5 kDa and 64.4 ± 14.5 nM in POM. The enrichment of polysaccharides in the SML appeared to be a common feature, with EFs ranging from 1.7 to 7.0 for particulate polysaccharides and 3.5 to 12.1 for polysaccharides in the HMW DOM fraction. A calculated monosaccharide yield suggests that polymers in the HMW DOM fraction were scavenged, without substantial degradation, into the SML. Bubble scavenging experiments showed that newly aggregated particles could be formed abiotically by coagulation of low molecular weight nanometer-sized gels. Aerosol particles, artificially generated by bubbling experiments, were enriched in polysaccharides by factors of 22–70, relative to the source seawater. We propose that bubble scavenging of surface-active polysaccharides could be one of the possible mechanisms for the

  11. Desempenho e avaliação econômica da alimentação de cordeiros confinados com dietas contendo diferentes relações volumoso: concentrado Performance and economic evaluation of the feeding of feedlot lambs with diets with different roughage: concentrate ratios

    Directory of Open Access Journals (Sweden)

    Sérgio Carvalho

    2007-10-01

    Full Text Available Este estudo objetivou avaliar o efeito do uso de diferentes relações volumoso:concentrado sobre o desempenho, as características de carcaça e o conteúdo gastrintestinal de cordeiros, bem como realizar uma avaliação econômica da alimentação de cordeiros confinados na fase de terminação. Foram utilizados 25 cordeiros, machos não-castrados, da raça Texel, desmamados com a idade média de 60 dias, e distribuídos aleatoriamente em cinco tratamentos, compostos por diferentes relações volumoso:concentrado, sendo: 30:70; 40:60; 50:50; 60:40 e 70:30, em base da matéria seca (MS. O volumoso utilizado foi o feno de Tifton-85 e o alimento concentrado era constituído por ração comercial, farelo de soja, calcário calcítico e fosfato bicálcico, em diferentes proporções. O período experimental teve duração de 80 dias, quando os animais foram abatidos. O aumento do teor de volumoso e a diminuição no teor de concentrado nas dietas promoveu redução linear (P£0,01 no ganho de peso diário e peso vivo ao abate. O consumo de matéria seca e a conversão alimentar foram influenciados de forma quadrática pelo aumento da relação volumoso:concentrado. Verificou-se redução linear (P£0,01 no peso de carcaça quente, rendimento de carcaça quente e nos pesos de quarto (perna, paleta, costilhar, pescoço e de vísceras verdes vazias, com o aumento do teor de volumoso e a diminuição no teor de concentrado nas dietas. Ocorreu crescimento linear nas proporções de vísceras verdes cheias (P£0,05 e de conteúdo gastrintestinal (P£0,01 com a elevação da proporção de volumoso e com a redução na proporção de concentrado nas dietas. A lucratividade em relação à venda dos cordeiros vivos não diferiu entre os tratamentos, apresentando um valor médio de R$ 57,00 por cordeiro. Houve redução linear (P£0,05 na lucratividade em relação à venda das carcaças dos cordeiros com o aumento da proporção de volumoso e com a diminui

  12. Bioengineering Human Myocardium on Native Extracellular Matrix

    Science.gov (United States)

    Guyette, Jacques P.; Charest, Jonathan M; Mills, Robert W; Jank, Bernhard J.; Moser, Philipp T.; Gilpin, Sarah E.; Gershlak, Joshua R.; Okamoto, Tatsuya; Gonzalez, Gabriel; Milan, David J.; Gaudette, Glenn R.; Ott, Harald C.

    2015-01-01

    Rationale More than 25 million individuals suffer from heart failure worldwide, with nearly 4,000 patients currently awaiting heart transplantation in the United States. Donor organ shortage and allograft rejection remain major limitations with only about 2,500 hearts transplanted each year. As a theoretical alternative to allotransplantation, patient-derived bioartificial myocardium could provide functional support and ultimately impact the treatment of heart failure. Objective The objective of this study is to translate previous work to human scale and clinically relevant cells, for the bioengineering of functional myocardial tissue based on the combination of human cardiac matrix and human iPS-derived cardiac myocytes. Methods and Results To provide a clinically relevant tissue scaffold, we translated perfusion-decellularization to human scale and obtained biocompatible human acellular cardiac scaffolds with preserved extracellular matrix composition, architecture, and perfusable coronary vasculature. We then repopulated this native human cardiac matrix with cardiac myocytes derived from non-transgenic human induced pluripotent stem cells (iPSCs) and generated tissues of increasing three-dimensional complexity. We maintained such cardiac tissue constructs in culture for 120 days to demonstrate definitive sarcomeric structure, cell and matrix deformation, contractile force, and electrical conduction. To show that functional myocardial tissue of human scale can be built on this platform, we then partially recellularized human whole heart scaffolds with human iPSC-derived cardiac myocytes. Under biomimetic culture, the seeded constructs developed force-generating human myocardial tissue, showed electrical conductivity, left ventricular pressure development, and metabolic function. Conclusions Native cardiac extracellular matrix scaffolds maintain matrix components and structure to support the seeding and engraftment of human iPS-derived cardiac myocytes, and enable

  13. Filter based phase distortions in extracellular spikes.

    Science.gov (United States)

    Yael, Dorin; Bar-Gad, Izhar

    2017-01-01

    Extracellular recordings are the primary tool for extracting neuronal spike trains in-vivo. One of the crucial pre-processing stages of this signal is the high-pass filtration used to isolate neuronal spiking activity. Filters are characterized by changes in the magnitude and phase of different frequencies. While filters are typically chosen for their effect on magnitudes, little attention has been paid to the impact of these filters on the phase of each frequency. In this study we show that in the case of nonlinear phase shifts generated by most online and offline filters, the signal is severely distorted, resulting in an alteration of the spike waveform. This distortion leads to a shape that deviates from the original waveform as a function of its constituent frequencies, and a dramatic reduction in the SNR of the waveform that disrupts spike detectability. Currently, the vast majority of articles utilizing extracellular data are subject to these distortions since most commercial and academic hardware and software utilize nonlinear phase filters. We show that this severe problem can be avoided by recording wide-band signals followed by zero phase filtering, or alternatively corrected by reversed filtering of a narrow-band filtered, and in some cases even segmented signals. Implementation of either zero phase filtering or phase correction of the nonlinear phase filtering reproduces the original spike waveforms and increases the spike detection rates while reducing the number of false negative and positive errors. This process, in turn, helps eliminate subsequent errors in downstream analyses and misinterpretations of the results.

  14. Filter based phase distortions in extracellular spikes

    Science.gov (United States)

    Yael, Dorin

    2017-01-01

    Extracellular recordings are the primary tool for extracting neuronal spike trains in-vivo. One of the crucial pre-processing stages of this signal is the high-pass filtration used to isolate neuronal spiking activity. Filters are characterized by changes in the magnitude and phase of different frequencies. While filters are typically chosen for their effect on magnitudes, little attention has been paid to the impact of these filters on the phase of each frequency. In this study we show that in the case of nonlinear phase shifts generated by most online and offline filters, the signal is severely distorted, resulting in an alteration of the spike waveform. This distortion leads to a shape that deviates from the original waveform as a function of its constituent frequencies, and a dramatic reduction in the SNR of the waveform that disrupts spike detectability. Currently, the vast majority of articles utilizing extracellular data are subject to these distortions since most commercial and academic hardware and software utilize nonlinear phase filters. We show that this severe problem can be avoided by recording wide-band signals followed by zero phase filtering, or alternatively corrected by reversed filtering of a narrow-band filtered, and in some cases even segmented signals. Implementation of either zero phase filtering or phase correction of the nonlinear phase filtering reproduces the original spike waveforms and increases the spike detection rates while reducing the number of false negative and positive errors. This process, in turn, helps eliminate subsequent errors in downstream analyses and misinterpretations of the results. PMID:28358895

  15. Ciliary extracellular vesicles: Txt msg orgnlls

    Science.gov (United States)

    Wang, Juan; Barr, Maureen M.

    2016-01-01

    Cilia are sensory organelles that protrude from cell surfaces to monitor the surrounding environment. In addition to its role as sensory receiver, the cilium also releases extracellular vesicles (EVs). The release of sub-micron sized EVs is a conserved form of intercellular communication used by all three kingdoms of life. These extracellular organelles play important roles in both short and long range signaling between donor and target cells and may coordinate systemic responses within an organism in normal and diseased states. EV shedding from ciliated cells and EV-cilia interactions are evolutionarily conserved phenomena, yet remarkably little is known about the relationship between the cilia and EVs and the fundamental biology of EVs. Studies in the model organisms Chlamydomonas and C. elegans have begun to shed light on ciliary EVs. Chlamydomonas EVs are shed from tips of flagella and are bioactive. C. elegans EVs are shed and released by ciliated sensory neurons in an intraflagellar transport (IFT)-dependent manner. C. elegans EVs play a role in modulating animal-to-animal communication, and this EV bioactivity is dependent on EV cargo content. Some ciliary pathologies, or ciliopathies, are associated with abnormal EV shedding or with abnormal cilia-EV interactions, suggest the cilium may be an important organelle as an EV donor or as an EV target. Until the past few decades, both cilia and EVs were ignored as vestigial or cellular junk. As research interest in these two organelles continues to gain momentum, we envision a new field of cell biology emerging. Here, we propose that the cilium is a dedicated organelle for EV biogenesis and EV reception. We will also discuss possible mechanisms by which EVs exert bioactivity and explain how what is learned in model organisms regarding EV biogenesis and function may provide insight to human ciliopathies. PMID:26983828

  16. Role of extracellular superoxide dismutase in hypertension.

    Science.gov (United States)

    Gongora, Maria Carolina; Qin, Zhenyu; Laude, Karine; Kim, Ha Won; McCann, Louise; Folz, J Rodney; Dikalov, Sergey; Fukai, Tohru; Harrison, David G

    2006-09-01

    We previously found that angiotensin II-induced hypertension increases vascular extracellular superoxide dismutase (ecSOD), and proposed that this is a compensatory mechanism that blunts the hypertensive response and preserves endothelium-dependent vasodilatation. To test this hypothesis, we studied ecSOD-deficient mice. ecSOD(-/-) and C57Blk/6 mice had similar blood pressure at baseline; however, the hypertension caused by angiotensin II was greater in ecSOD(-/-) compared with wild-type mice (168 versus 147 mm Hg, respectively; P<0.01). In keeping with this, angiotensin II increased superoxide and reduced endothelium-dependent vasodilatation in small mesenteric arterioles to a greater extent in ecSOD(-/-) than in wild-type mice. In contrast to these findings in resistance vessels, angiotensin II paradoxically improved endothelium-dependent vasodilatation, reduced intracellular and extracellular superoxide, and increased NO production in aortas of ecSOD(-/-) mice. Whereas aortic expression of endothelial NO synthase, Cu/ZnSOD, and MnSOD were not altered in ecSOD(-/-) mice, the activity of Cu/ZnSOD was increased by 80% after angiotensin II infusion. This was associated with a concomitant increase in expression of the copper chaperone for Cu/ZnSOD in the aorta but not in the mesenteric arteries. Moreover, the angiotensin II-induced increase in aortic reduced nicotinamide-adenine dinucleotide phosphate oxidase activity was diminished in ecSOD(-/-) mice as compared with controls. Thus, during angiotensin II infusion, ecSOD reduces hypertension, minimizes vascular superoxide production, and preserves endothelial function in resistance arterioles. We also identified novel compensatory mechanisms involving upregulation of copper chaperone for Cu/ZnSOD, increased Cu/ZnSOD activity, and decreased reduced nicotinamide-adenine dinucleotide phosphate oxidase activity in larger vessels. These compensatory mechanisms preserve large vessel function when ecSOD is absent in

  17. Oncogenic extracellular vesicles in brain tumour progression

    Directory of Open Access Journals (Sweden)

    Esterina eD'Asti

    2012-07-01

    Full Text Available The brain is a frequent site of neoplastic growth, including both primary and metastatic tumours. The clinical intractability of many brain tumours and their distinct biology are implicitly linked to the unique microenvironment of the central nervous system (CNS and cellular interactions within. Among the most intriguing forms of cellular interactions is that mediated by membrane-derived extracellular vesicles (EVs. Their biogenesis (vesiculation and uptake by recipient cells serves as a unique mechanism of intercellular trafficking of complex biological messages including the exchange of molecules that cannot be released through classical secretory pathways, or that are prone to extracellular degradation. Tumour cells produce EVs containing molecular effectors of several cancer-related processes such as growth, invasion, drug resistance, angiogenesis, and coagulopathy. Notably, tumour-derived EVs (oncosomes also contain oncogenic proteins, transcripts, DNA and microRNA (miR. Uptake of this material may change properties of the recipient cells and impact the tumour microenvironment. Examples of transformation-related molecules found in the cargo of tumour-derived EVs include the oncogenic epidermal growth factor receptor (EGFRvIII, tumour suppressors (PTEN and oncomirs (miR-520g. It is postulated that EVs circulating in blood or cerebrospinal fluid (CSF of brain tumour patients may be used to decipher molecular features (mutations of the underlying malignancy, reflect responses to therapy or molecular subtypes of primary brain tumours (e.g. glioma or medulloblastoma. It is possible that metastases to the brain may also emit EVs with clinically relevant oncogenic signatures. Thus EVs emerge as a novel and functionally important vehicle of intercellular communication that can mediate multiple biological effects. In addition, they provide a unique platform to develop molecular biomarkers in brain malignancies.

  18. Identification of a receptor for extracellular renalase.

    Directory of Open Access Journals (Sweden)

    Ling Wang

    Full Text Available An increased risk for developing essential hypertension, stroke and diabetes is associated with single nucleotide gene polymorphisms in renalase, a newly described secreted flavoprotein with oxidoreductase activity. Gene deletion causes hypertension, and aggravates acute ischemic kidney (AKI and cardiac injury. Independent of its intrinsic enzymatic activities, extracellular renalase activates MAPK signaling and prevents acute kidney injury (AKI in wild type (WT mice. Therefore, we sought to identity the receptor for extracellular renalase.RP-220 is a previously identified, 20 amino acids long renalase peptide that is devoid of any intrinsic enzymatic activity, but it is equally effective as full-length recombinant renalase at protecting against toxic and ischemic injury. Using biotin transfer studies with RP-220 in the human proximal tubular cell line HK-2 and protein identification by mass spectrometry, we identified PMCA4b as a renalase binding protein. This previously characterized plasma membrane ATPase is involved in cell signaling and cardiac hypertrophy. Co-immunoprecipitation and co-immunolocalization confirmed protein-protein interaction between endogenous renalase and PMCA4b. Down-regulation of endogenous PMCA4b expression by siRNA transfection, or inhibition of its enzymatic activity by the specific peptide inhibitor caloxin1b each abrogated RP-220 dependent MAPK signaling and cytoprotection. In control studies, these maneuvers had no effect on epidermal growth factor mediated signaling, confirming specificity of the interaction between PMCA4b and renalase.PMCA4b functions as a renalase receptor, and a key mediator of renalase dependent MAPK signaling.

  19. Evaluation of {sup 222}Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil; Avaliacao da concentracao do {sup 222}Rn nos ambientes internos e externos de residencias do municipio de Monte Alegre, PA

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Vicente de Paula

    1999-07-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas {sup 222}Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 {sup W}, used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of {sup 222}Rn in the residences of Monte Alegre and CANP. Determinations of the {sup 238}U and {sup 226}Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m{sup 3} (action level) and 600 Bq. m{sup 3} (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  20. Extracellular polymeric substances mediate bioleaching/biocorrosion via interfacial processes involving iron(III) ions and acidophilic bacteria.

    Science.gov (United States)

    Sand, Wolfgang; Gehrke, Tilman

    2006-01-01

    Extracellular polymeric substances seem to play a pivotal role in biocorrosion of metals and bioleaching, biocorrosion of metal sulfides for the winning of precious metals as well as acid rock drainage. For better control of both processes, the structure and function of extracellular polymeric substances of corrosion-causing or leaching bacteria are of crucial importance. Our research focused on the extremophilic bacteria Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, because of the "simplicity" and knowledge about the interactions of these bacteria with their substrate/substratum and their environment. For this purpose, the composition of the corresponding extracellular polymeric substances and their functions were analyzed. The extracellular polymeric substances of both species consist mainly of neutral sugars and lipids. The functions of the exopolymers seem to be: (i) to mediate attachment to a (metal) sulfide surface, and (ii) to concentrate iron(III) ions by complexation through uronic acids or other residues at the mineral surface, thus, allowing an oxidative attack on the sulfide. Consequently, dissolution of the metal sulfide is enhanced, which may result in an acceleration of 20- to 100-fold of the bioleaching process over chemical leaching. Experiments were performed to elucidate the importance of the iron(III) ions complexed by extracellular polymeric substances for strain-specific differences in oxidative activity for pyrite. Strains of A. ferrooxidans with a high amount of iron(III) ions in their extracellular polymeric substances possess greater oxidation activity than those with fewer iron(III) ions. These data provide insight into the function of and consequently the advantages that extracellular polymeric substances provide to bacteria. The role of extracellular polymeric substances for attachment under the conditions of a space station and resulting effects like biofouling, biocorrosion, malodorous gases, etc. will be discussed.

  1. Determination of the chemical composition and functional properties of shrimp waste protein concentrate and lyophilized flour Determinação da composição química e das propriedades funcionais de concentrado protéico e de farinha liofilizada de resíduos de camarão

    Directory of Open Access Journals (Sweden)

    Olivaldo Lacerda Brasileiro

    2012-04-01

    Full Text Available Wastes from the seafood industry can be easily processed into products with new forms of use. The present study was aimed at determining the chemical composition and functional properties of shrimp waste protein concentrate and lyophilized flour. The raw material used in this study consisted of waste (head of Litopenaeus vannamei. The protein concentrate was obtained by ethanolic extraction, being subsequently submitted to drying in oven at 70° C, while the flour was obtained by lyophilization of shrimp wastes. Moisture, ash, protein and calcium contents showed significant difference between fresh shrimp head waste samples (IN and protein concentrate and lyophilized flour samples. The protein content for protein concentrate (PC and lyophilized flour (LF showed significant increase in relation to protein content in the waste (IN, thus showing that the process for obtaining the protein concentrate was efficient.Resíduos provenientes da indústria do pescado podem ser facilmente transformados em produtos com novas formas de aproveitamento. No presente estudo, objetivou-se determinar a composição química e as propriedades funcionais de farinha liofilizada e concentrado proteico provenientes de resíduos de camarão. A matéria-prima empregada neste estudo foi constituída de resíduos (cabeça de camarão Litopenaeus vannamei. O concentrado proteico foi obtido por extração etanólica e, posteriormente, submetido à secagem em estufa a 70° C, enquanto a farinha foi obtida pelo processo de liofilização do resíduo. Os teores de umidade, cinzas, proteínas e cálcio apresentaram diferença significativa entre as amostras de resíduo de cabeça de camarão in natura (IN e as amostras de concentrado proteico e farinha liofilizada. O teor de proteínas para concentrado protéico (CP e para a farinha liofilizada (FL apresentou aumento significativo em relação ao teor proteico do resíduo (IN, mostrando, assim, que o processo de elaboração do

  2. Extracellular polymeric substances act as transient media in extracellular electron transfer of Shewanella oneidensis MR-1

    DEFF Research Database (Denmark)

    Xiao, Yong; Zhang, Jingdong; Ulstrup, Jens

    without extracting EPS or cells collected from log stage or early-steady stage cultures with little EPS. Therefore, microbial cells are believed in contact directly with each other or electrode. Such attempt apparently ignored the role of EPS in microbial EET, even though many components of EPS......It is well known that microorganism is surrounded by extracellular polymeric substances (EPS) which include polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and humic acids. However, previous studies on microbial extracellular electron transfer (EET) are conducted on cells......, such as DNA, humic acids and some proteins, are electrochemically active or semiconductive. Herein, we report experimental evidences of EPS role on EET for Shewanella oneidensis MR-1. Atomic force microscopy clearly showed that the cell surface was cleaned and few EPS could be observed on MR-1 after...

  3. The liver in patients with [beta]-thalassemia major. Determination of iron concentration with Magnetic Resonance Imaging. Il fegato dei pazienti affetti da [beta]-talassemia major. Determinazione della concentrazione di ferro con Risonanza Magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Midiri, M. (Bari, Policlinico Univ. (Italy). Ist. di Radiologia); Gallo, C.; Finazzo, M. (Palermo, Policlinico Univ. ' P. Giaccone' (Italy). Ist. di Radiologia ' Pietro Cignolini' )

    The paper investigates the clinical usefulness of liver MRI in a large multicenter study because the control of iron concentration (LIC) is crucial in thalassemia major (TM) prognosis and conflicting results have been reported in small and heterogeneous groups of patients using MRI, the only very common non-invasive procedure. One hundred and eight consecutive TM patients, selected according to a specific protocol, were included in the study. This study shows that LIC can be calculated as a function of SIR. A validation study is necessary before introducing this prediction rule in clinical practice.

  4. Influência da concentração de benzocaína e do comprimento dos peixes na anestesia e na recuperação de tilápias-do-nilo Effect of benzocaine concentration and fish size on anesthesia and recovery in Nile tilapia

    Directory of Open Access Journals (Sweden)

    Daniel Okamura

    2010-05-01

    Full Text Available Com o objetivo de avaliar a influência da concentração de benzocaína na indução e recuperação da anestesia em tilápias-do-nilo (Oreochromis niloticus de diferentes comprimentos, desenvolveu-se um experimento em blocos casualizados, em esquema fatorial 4 × 4, composto de quatro comprimentos de peixes (6; 10; 14 e 18 cm de comprimento total e quatro concentrações de benzocaína (60; 120; 180 e 240 mg por litro de água. A indução e a recuperação da anestesia foram divididas em três estágios, de acordo com o comportamento dos peixes sob efeito do anestésico, registrando-se o tempo de permanência em cada estágio. As diferenças de comprimento não influenciaram de forma significativa os tempos de anestesia e recuperação. Regressões lineares com plateau foram geradas para estimar o ponto em que o aumento da dose deixou de ter efeito. Durante a indução à anestesia, o plateau ocorreu na concentração de 132 mg/L e o tempo estimado para atingir a sedação total (estágio 3 foi de 86 segundos. Para permanência do peixe sob sedação total, é necessária concentração de benzocaína de 190 mg/L e o tempo estimado de permanência neste estágio é de 91,1 segundos. Concentrações superiores a 190 mg de benzocaína por litro de água não produzem efeitos que justifiquem seu emprego.To evaluate the influence of benzocaine concentration on the induction and recovery from anesthesia in different sized Nile tilapia (Oreochromis niloticus, it was developed a random block experiment design in 4 × 4 factorial consisted of four fish lengths (6; 10; 14 and 18 cm total lenght and four benzocaine concentrations (60; 120; 180 and 240 mg of benzocaine per liter of water. The induction and the recovery from anesthesia were divided in three stages based on the behavior of the fishes under anesthetic effect. The time spent in each stage was recorded. Differences in length did not affect significantly the anesthesia and recovery time

  5. Incorporation of Tenascin-C into the Extracellular Matrix by Periostin Underlies an Extracellular Meshwork Architecture*

    OpenAIRE

    Kii, Isao; Nishiyama, Takashi; Li, Minqi; Matsumoto, Ken-Ichi; Saito, Mitsuru; Amizuka, Norio; Kudo, Akira

    2009-01-01

    Extracellular matrix (ECM) underlies a complicated multicellular architecture that is subjected to significant forces from mechanical environment. Although various components of the ECM have been enumerated, mechanisms that evolve the sophisticated ECM architecture remain to be addressed. Here we show that periostin, a matricellular protein, promotes incorporation of tenascin-C into the ECM and organizes a meshwork architecture of the ECM. We found that both periostin null mice and tenascin-C...

  6. Vegetative development of Dendrobium nobile Lindl. plants fertirrigated with diferents concentrations of sarruge nutritive solution / Desenvolvimento vegetativo de plantas de Dendrobium nobile Lindl. fertirrigadas com diferentes concentrações da solução nutritiva de sarruge

    Directory of Open Access Journals (Sweden)

    Adriane Marinho de Assis

    2004-05-01

    Full Text Available The objective of this work was evaluate the possible changes in the chemical and physical characteristics of quail eggs fed with diets containing fish oil and solid fraction of fish chemical silage, along 30 days. The experiment was conducted using 80 quails 19 weeks old, distributed in a total occasional design with 4 treatments, 5 repetitions and 4 birds by experimental unit. The physical analyses were: Haugh Unit, yolk index, volumes of albumens and yolks and relationship of albumen/egg, yolk/egg and shell/egg. For the chemical analyses was used official methodology, specific for eggs. In this work was verified, in the end of the analysed time, a weigth loss of 3,43%; a decrease in the albumen quality, the Haugh Unit lowered from 67 to 64 and a rise of 5% in the humidity percentual of the yolks. Also was observed that the albumen volume is stabler than of the yolks and that the albumen proteins are instable front to its basic pH.A orquídea Dendrobium nobile é natural da parte baixa do Himalaia e regiões serranas do Sri Lanka, estando adaptada às condições brasileiras. O objetivo do experimento foi avaliar o crescimento vegetativo de plantas de Dendrobium nobile fertirrigadas com diferentes concentrações de solução de Sarruge. As plantas foram cultivadas em estufa com 50% de luminosidade, em vasos plásticos pretos, tendo como substrato xaxim desfibrado. Estas foram fertirrigadas uma vez por semana e irrigadas duas vezes por semana. Os tratamentos utilizados foram: T1 Testemunha; 2 Torta de mamona + farinha de osso 2:1; T3 Sarruge 100%; T4 Sarruge 25%; T5 Sarruge 50%; T6 Sarruge 75%; T7 Sarruge 125%; T8 Sarruge 150%. O delineamento experimental utilizado foi o inteiramente casualizado com 10 repetições por tratamento. Foram avaliados o crescimento vegetativo e o número de brotos após 7 meses do início do experimento. O melhor resultado foi observado no tratamento em que se utilizou solução de Sarruge 75%.

  7. MATHEMATICAL MODELING OF PHOSPHORUS CONCENTRATION: A TOOL FOR WATER RESOURCES MANAGEMENT = MODELAGEM MATEMÁTICA DA CONCENTRAÇÃO DE FÓSFORO: UMA FERRAMENTA PARA A GESTÃO DOS RECURSOS HÍDRICOS

    Directory of Open Access Journals (Sweden)

    Camila Pereira Montovani

    2013-01-01

    Full Text Available Water is a key asset to life, it is imperative to guarantee their quality, among other reasons, to the survival of living beings. Nowadays, with the range of the anthropogenic activities, it is important that rivers, reservoirs and springs are with physical, chemical and biological character according to the standards established by government, according to the class as intended. With the purpose to develop a tool to support the management of water resources for analysis of behavior pollutants, we carried out a phosphorus modeling based on mathematical and computational tools, in a public water supply source. The results feature the pollutant evolutionary behavior, allowing to analyze scenarios and make decisions with a view to preventive or remedial about a component that, in excess, interfere with water quality, mainly, in the eutrophication process that undertakes all the local biota. = A água é um bem essencial à vida, dessa forma é imprescindível a garantia de sua qualidade para, dentre outras razões, a sobrevivência dos seres vivos. Hoje em dia, com a amplitude e o desenvolvimento das atividades antrópicas, é importante que rios, reservatórios e mananciais estejam com características físicas, químicas e biológicas dentro dos padrões estabelecidos pelos órgãos governamentais, de acordo com a classe a que se destinam. Com o intuito de se desenvolver uma ferramenta de suporte à gestão de recursos hídricos para análises de comportamento de poluentes, realizou-se uma modelagem da concentração do componente fósforo baseado em instrumentos matemáticos e computacionais, num manancial de abastecimento público. Os resultados obtidos apresentam o comportamento evolutivo do poluente e possibilitam a geração de cenários e a tomada de decisões com vistas a ações preventivas ou de remediação acerca de um componente que, em excesso, interfere na qualidade das águas devido, principalmente, ao processo de eutrofiza

  8. Effect of Ionic Diffusion on Extracellular Potentials in Neural Tissue.

    Directory of Open Access Journals (Sweden)

    Geir Halnes

    2016-11-01

    Full Text Available Recorded potentials in the extracellular space (ECS of the brain is a standard measure of population activity in neural tissue. Computational models that simulate the relationship between the ECS potential and its underlying neurophysiological processes are commonly used in the interpretation of such measurements. Standard methods, such as volume-conductor theory and current-source density theory, assume that diffusion has a negligible effect on the ECS potential, at least in the range of frequencies picked up by most recording systems. This assumption remains to be verified. We here present a hybrid simulation framework that accounts for diffusive effects on the ECS potential. The framework uses (1 the NEURON simulator to compute the activity and ionic output currents from multicompartmental neuron models, and (2 the electrodiffusive Kirchhoff-Nernst-Planck framework to simulate the resulting dynamics of the potential and ion concentrations in the ECS, accounting for the effect of electrical migration as well as diffusion. Using this framework, we explore the effect that ECS diffusion has on the electrical potential surrounding a small population of 10 pyramidal neurons. The neural model was tuned so that simulations over ∼100 seconds of biological time led to shifts in ECS concentrations by a few millimolars, similar to what has been seen in experiments. By comparing simulations where ECS diffusion was absent with simulations where ECS diffusion was included, we made the following key findings: (i ECS diffusion shifted the local potential by up to ∼0.2 mV. (ii The power spectral density (PSD of the diffusion-evoked potential shifts followed a 1/f2 power law. (iii Diffusion effects dominated the PSD of the ECS potential for frequencies up to several hertz. In scenarios with large, but physiologically realistic ECS concentration gradients, diffusion was thus found to affect the ECS potential well within the frequency range picked up in

  9. Extracellular Ca2+ Is Required for Fertilization in the African Clawed Frog, Xenopus laevis

    Science.gov (United States)

    Duray, Alexis M.; Tembo, Maiwase; Beleny, David O.; Napolitano, Marc A.; Sauer, Monica L.; Wisner, Bennett W.

    2017-01-01

    Background The necessity of extracellular Ca2+ for fertilization and early embryonic development in the African clawed frog, Xenopus laevis, is controversial. Ca2+ entry into X. laevis sperm is reportedly required for the acrosome reaction, yet fertilization and embryonic development have been documented to occur in high concentrations of the Ca2+ chelator BAPTA. Here we sought to resolve this controversy. Methodology/principal finding Using the appearance of cleavage furrows as an indicator of embryonic development, we found that X. laevis eggs inseminated in a solution lacking added divalent cations developed normally. By contrast, eggs inseminated in millimolar concentrations of BAPTA or EGTA failed to develop. Transferring embryos to varying solutions after sperm addition, we found that extracellular Ca2+ is specifically required for events occurring within the first 30 minutes after sperm addition, but not after. We found that the fluorescently stained sperm were not able to penetrate the envelope of eggs inseminated in high BAPTA, whereas several had penetrated the vitelline envelope of eggs inseminated without a Ca2+ chelator, or with BAPTA and saturating CaCl2. Together these results indicate that fertilization does not occur in high concentrations of Ca2+ chelators. Finally, we found that the jelly coat includes >5 mM of readily diffusible Ca2+. Conclusions/Significance Taken together, these data are consistent with requirement of extracellular Ca2+ for fertilization. Based on our findings, we hypothesize that the jelly coat surrounding the egg acts as a reserve of readily available Ca2+ ions to foster fertilization in changing extracellular milieu. PMID:28114360

  10. Análise dos compostos voláteis da aguardente de cana por concentração dinâmica do "headspace" e cromatografia gasosa-espectrometria de massas The analysis of volatile compounds from Brazilian sugar cane spirit by dynamic headspace concentration and gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Ian Carneiro da Cunha Nóbrega

    2003-08-01

    Full Text Available Os compostos voláteis da aguardente de cana foram extraídos por meio da concentração dinâmica do "headspace" em armadilhas contendo Tenax-TA e analisados por cromatografia gasosa-espectrometria de massas. Cerca de 100 compostos voláteis, com número de carbonos que variavam de 5 a 18, foram detectados. Destes, 22 foram selecionados, sendo 18 ésteres, com base nas suas quantidades no extrato ou nas suas características sensoriais obtidas na literatura. Os compostos presentes em maiores quantidades foram o 3-metil-1-butanol (álcool isoamílico, 1,1-dietoxi-etano (acetaldeído dietil acetal e os ésteres acetato de 3-metilbutila, hexanoato de etila, octanoato de etila, decanoato de etila e dodecanoato de etila. Dentre os compostos identificados em menor quantidade, destacou-se, devido a sua natureza química, o composto sulfurado 4,5-de-hidro-2-metil-3(2H-tiofenona. Esta é a primeira vez que este e outros compostos voláteis são reportados em aguardente de cana. Conclui-se que a metodologia empregada neste trabalho permitiu a identificação de compostos voláteis da fração C5-C18, que potencialmente contribuem para o aroma da aguardente de cana.The volatile compounds of Brazilian sugar cane spirit, the fermented and distilled juice of sugar cane, were extracted by dynamic headspace concentration on Tenax-TA trap and analyzed by gas chromatography-mass spectrometry. Approximately 100 volatile compounds with carbon number ranging from 5 to 18 were detected. Among these, 18 esters and 4 compounds from other chemical classes were selected for this work on the basis of their quantity in the extract or their sensory qualities obtained from literature. The major compounds identified were 3-methyl-1-butanol (isoamyl alcohol, 1,1-diethoxy-ethane (acetaldehyde diethyl acetal and the esters 3-methylbutyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and ethyl dodecanoate. In minor quantities, potentially important aroma compounds

  11. Atmospheric CO2 and soil extracellular enzyme activity: A meta-analysis and CO2 gradient experiment

    Science.gov (United States)

    Rising atmospheric CO2 concentrations may alter carbon and nutrient cycling and microbial processes in terrestrial ecosystems. One of the primary ways that microbes interact with soil organic matter is through the production of extracellular enzymes, which break down large, complex organic molecules...

  12. Study of the reaction between {sup 51}CrO{sub 3} and concentrated nitric acid by radio chromatographic methods; Estudo da reacao entre {sup 51}CrO{sub 3} e acido nitrico concentrado por metodos radiocromatograficos

    Energy Technology Data Exchange (ETDEWEB)

    Pezzin, Sergio H. [Univesidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Centro de Ciencias Tecnologicas; Collins, Carol H.; Collins, Kenneth E. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica

    2000-07-01

    The objective of the present work is to verify the reduction of CrO{sub 3} in concentrated nitric acid, using {sup 51}Cr as a tracer. For the study, {sup 51}CrO{sub 3} (ca. 200,000 cpm/mg) was added to 65% HNO{sub 3} and maintained under agitation at 20 deg C for specified time periods. Aliquots (100 {mu}) were analyzed by open column cation (AG50Wx8, 100-200 mesh, Na{sup +} form) chromatography, either immediately or after dilution to approximately pH 2 and storage for specified time periods. The separations, which were made by stepwise elution using HClO{sub 4} and Ca(ClO{sub 4}){sub 2} solutions as effluents with fraction collection, followed by counting with a NaI(Tl) detector and a single channel analyzer. It was verified that ca. 3.5% of Cr(III) is obtained after 15 min of reaction. The major reaction product is hexaaquo chromium(III), with minor concentrations of mononitrate penta-aquochromium(III), [Cr(H{sub 2}O){sub 5}NO{sub 3}]{sup 2+}, a product which undergoes watering at pH 2 to produce, after 360 h, [Cr(H{sub 2}O){sub 6}]{sup 3+}. (author)

  13. Development of a sublation system in atmospheric tank using sunflower oil surfactant to reduce oily water concentration; Desenvolvimento de um sistema de sublacao em tanque atmosferico utilizando tensoativo de oleo de girassol para reducao da concentracao de aguas oleosas

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Rodrigo F. de; Dantas, Iuri A.C.; Quintaes, Filipe de O.; Salazar, Andres O.; Barros Neto, Eduardo L. de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    In order to reduce the rate of oil in water, was developed a system capable to be inserted in a tank and make air bubbles move to top of the tank, where is a layer of oil, similar that occurs in flotation, but in this case is called sublation. This system is composed by drilled PVC pipes and connected in way of four identical squares, joined by a high pressure hose. A compressor located in a region near to the tank supplies air to the system through the hose, that is connected in the central point of the system. The preliminary results had shown that the concentration after the sublation, without the surfactants use, decrease of 70 ppm to 35 ppm. After the sublation using surfactants this concentration decrease of 70ppm to 24,8 ppm. The efficiency of the sublation process using surfactants made of vegetal oil - OGS - was proved by the experimental results. This process, beyond allowing a bigger reutilization of the water in the tests of the laboratory, makes possible the reduction of the rate of oil in water to permitted levels by CONAMA. (author)

  14. Development of a sublation system in atmospheric tank using sunflower oil surfactant to reduce oily water concentration; Desenvolvimento de um sistema de sublacao em tanque atmosferico utilizando tensoativo de oleo de girassol para reducao da concentracao de aguas oleosas

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Rodrigo F. de; Dantas, Iuri A.C.; Quintaes, Filipe de O.; Salazar, Andres O.; Barros Neto, Eduardo L. de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    In order to reduce the rate of oil in water, was developed a system capable to be inserted in a tank and make air bubbles move to top of the tank, where is a layer of oil, similar that occurs in flotation, but in this case is called sublation. This system is composed by drilled PVC pipes and connected in way of four identical squares, joined by a high pressure hose. A compressor located in a region near to the tank supplies air to the system through the hose, that is connected in the central point of the system. The preliminary results had shown that the concentration after the sublation, without the surfactants use, decrease of 70 ppm to 35 ppm. After the sublation using surfactants this concentration decrease of 70ppm to 24,8 ppm. The efficiency of the sublation process using surfactants made of vegetal oil - OGS - was proved by the experimental results. This process, beyond allowing a bigger reutilization of the water in the tests of the laboratory, makes possible the reduction of the rate of oil in water to permitted levels by CONAMA. (author)

  15. Influência do tipo de ácido usado e da sua concentração na ativação de uma argila bentonítica Influence of the type and concentration of the used acid on the activation of bentonite clays

    Directory of Open Access Journals (Sweden)

    E. L. Foletto

    2001-12-01

    Full Text Available A ativação ácida de uma argila tem por finalidade aumentar as suas propriedades adsortivas e catalíticas. Nesse estudo, uma amostra de argila bentonítica, proveniente da Província de Mendoza (Argentina, foi ativada com diferentes concentrações (4 e 8 N por ácido sulfúrico e clorídrico. Para verificar a influência das concentrações e do tipo de ácido usado na ativação da argila, utilizou-se técnicas de difração de raios X, análise térmica diferencial e termogravimétrica e análise química. Os resultados mostraram que houve modificação na estrutura do material argiloso após o ataque ácido. O tratamento com ácido sulfúrico e clorídrico sobre uma mesma bentonita originou produtos com diferentes características estruturais.The clay acid activation has the purpose of increasing its adsorbent and catalytic properties. In this study, a bentonite clay sample from Mendoza (Argentine was activated in different concentrations (4 N and 8 N through the use of sulphuric and hydrochloric acid. To verify the influence of concentrations and the kind of acid utilized in the clay activation, it was utilized techniques of X-ray diffraction, thermogravimetric and differential thermal analysis and chemical analysis. The results have shown that the clay structure was modified after acid attack. Sulphuric and hydrochloric acid treatment in the same bentonite originated products with different structural characteristics.

  16. Alterations in brain extracellular dopamine and glycine levels following combined administration of the glycine transporter type-1 inhibitor Org-24461 and risperidone.

    Science.gov (United States)

    Nagy, Katalin; Marko, Bernadett; Zsilla, Gabriella; Matyus, Peter; Pallagi, Katalin; Szabo, Geza; Juranyi, Zsolt; Barkoczy, Jozsef; Levay, Gyorgy; Harsing, Laszlo G

    2010-12-01

    The most dominant hypotheses for the pathogenesis of schizophrenia have focused primarily upon hyperfunctional dopaminergic and hypofunctional glutamatergic neurotransmission in the central nervous system. The therapeutic efficacy of all atypical antipsychotics is explained in part by antagonism of the dopaminergic neurotransmission, mainly by blockade of D(2) dopamine receptors. N-methyl-D-aspartate (NMDA) receptor hypofunction in schizophrenia can be reversed by glycine transporter type-1 (GlyT-1) inhibitors, which regulate glycine concentrations at the vicinity of NMDA receptors. Combined drug administration with D(2) dopamine receptor blockade and activation of hypofunctional NMDA receptors may be needed for a more effective treatment of positive and negative symptoms and the accompanied cognitive deficit in schizophrenia. To investigate this type of combined drug administration, rats were treated with the atypical antipsychotic risperidone together with the GlyT-1 inhibitor Org-24461. Brain microdialysis was applied in the striatum of conscious rats and determinations of extracellular dopamine, DOPAC, HVA, glycine, glutamate, and serine concentrations were carried out using HPLC/electrochemistry. Risperidone increased extracellular concentrations of dopamine but failed to influence those of glycine or glutamate measured in microdialysis samples. Org-24461 injection reduced extracellular dopamine concentrations and elevated extracellular glycine levels but the concentrations of serine and glutamate were not changed. When risperidone and Org-24461 were added in combination, a decrease in extracellular dopamine concentrations was accompanied with sustained elevation of extracellular glycine levels. Interestingly, the extracellular concentrations of glutamate were also enhanced. Our data indicate that coadministration of an antipsychotic with a GlyT-1 inhibitor may normalize hypofunctional NMDA receptor-mediated glutamatergic neurotransmission with reduced

  17. ASPECTOS EPIDEMIOLÓGICOS DA QUEIMA DAS FOLHAS DA CENOURA (Daucus carota L CAUSADA POR Alternaria dauci (Kühn Groves & Skolko: Efeito da Concentração de Inóculo e Determinação do Período de Geração de Alternaria dauci (Kühn Groves & Skolko. EPIDEMIOLOGICAL ASPECTS OF LEAF BLIGHT OF CARROT (Daucus carota L. CAUSED BY Alternaria dauci (KÜHN GROVES & SKOLKO: EFFECT OF INOCULUN CONCENTRATION AND DETERMINATION OF THE GENERATION TIME OF Alternaria dauci

    Directory of Open Access Journals (Sweden)

    Yvo de Carvalho

    2007-09-01

    produzidos em agar-V8. Em síntese pode-se concluir que: 1. A concentração de inóculo afeta o grau de severidade da queima das folhas e, conseqüentemente, a produção; mas a freqüência do ciclo das infecções secundárias, é que parece determinar o caráter da epifitia. 2. A amplitude do período de geração de Alternaria dauci depende principalmente da vitalidade do inóculo.

    The effect of the concentration of conidial inoculum of Alternaria dauci (Kühn Groves & Skolko in relation to the degree of severity of occurrence of leaf blight on carrot (Daucus carota L. cultivar Nantes Half Long at 67 - 70 days of age, was studied. The plants were cultivated under green-house conditions innoculated by atomizing with spore suspension, and afterwards, maintained for 72 hours in an incubation chamber with temperature controlled at 18 – 24°C and relative humidity of 100% (foggy. The spore concentrations tests were 0, 10², 10³, 5x10³ and 2x10^4 spores/ml. There were significant differences in the treatments at the 5% level in relation to severity of the leaf blight, the total weight of the plants, and the weight of the roots. The generation period of the fungus was 6-7, 5, 6 and 6 days, respectively, at 16, 20, 24°C and room temperature. Detached leaflets were innoculated individually, by using a small brush to spread the spores. After innoculation, the leaflets were maintained in a moisture chamber. The vitality of the inoculum, seems to be a highly important factor in the determination of the generation time of the of fungus.

  18. Uso tópico da adrenalina em diferentes concentrações na cirurgia endoscópica nasal Topical use of adrenaline in different concentrations for endoscopic sinus surgery

    Directory of Open Access Journals (Sweden)

    Krishnamurti Matos de Araujo Sarmento Junior

    2009-04-01

    Full Text Available A concentração ideal de adrenalina tópica a promover hemostasia adequada sem toxicidade ainda é motivo de controvérsia. OBJETIVO: Comparar soluções tópicas de adrenalina em diferentes concentrações. DESENHO DO ESTUDO: Prospectivo, duplo-cego, seleção aleatória. MATERIAIS E MÉTODOS: 49 pacientes submetidos à cirurgia endoscópica nasal, divididos em 3 grupos usando exclusivamente adrenalina tópica, nas concentrações de 1:2000, 1:10.000 e 1:50.000. Comparou-se o tempo operatório, o sangramento, as concentrações plasmáticas de adrenalina e noradrenalina e a variação dos parâmetros cardiovasculares. RESULTADOS: O tempo operatório por procedimento foi menor no grupo que utilizou adrenalina 1:2000, assim como o sangramento (p The ideal adrenaline concentration remains unknown. AIM: Compare topical adrenaline solutions in different concentrations. STUDY DESIGN: Prospective, double blind, randomized trial. PATIENTS AND METHODS: 49 patients divided in 3 groups underwent endoscopic sinus surgery, using only topical solutions of adrenaline in different concentrations (1:2,000, 1:10,000 and 1:50,000. We compared the duration of surgery, intra-operative bleeding, plasmatic levels of catecholamines, hemodynamic parameters and changes in heart rhythm. RESULTS: Surgery time was shorter in the group using adrenaline 1:2,000, which also showed less bleeding in all evaluations (objective and subjective - p < 0.0001. Plasmatic levels of epinephrine rose in all groups, more sharply in the 1:2,000 group. There was a trend towards elevation of blood pressure in the groups using adrenaline 1:2,000 and 1:10,000, with a greater occurrence of hypertensive peaks. DISCUSSION: We found a very significance bleeding difference favoring the 1:2,000. The blood pressure elevation in the 1:2,000 and 1:10,000 groups was progressive but very slow throughout the procedure, which could be associated with the anesthesia technique. CONCLUSION: We favor the use

  19. Influência dos compostos nitrogenados na concentração de proteína da cianobactéria Aphanothece microscopica Nägeli Influence of nitrogen compounds on the protein concentration of the cyanobacterium Aphanothece microscopica Nägeli

    Directory of Open Access Journals (Sweden)

    Marcio Hornes

    2010-06-01

    Full Text Available O trabalho teve como objetivo avaliar a influência dos compostos nitrogenados na concentração de proteína da cianobactéria Aphanothece microscopica Nägeli quando cultivada em meio de cultivo padrão BG11 e no efluente do processamento de pescado. As condições experimentais foram inóculo de 200 mg.L-1, 30 °C, pH 7,6 e razão C/N 20. As amostras foram retiradas no início, meio e fim da fase logarítmica e da fase estacionária e analisadas quanto à concentração de nitrogênio total, nitrogênio não proteico, amônio, nitrato, nitrito e ácidos nucleicos. Ficou demonstrado em todas as culturas que o íon amônio, juntamente com os ácidos nucleicos, representa uma importante fração do nitrogênio não proteico presente na biomassa. Os resultados mostraram que o meio de cultivo influencia a concentração de nitrogênio e que a determinação de proteína pelo método de Kjeldahl superestima a concentração proteica em cianobactérias.This study aimed to evaluate the influence of nitrogen compounds on the protein concentration of the cyanobacterium Aphanothece microscopica Nägeli cultivated in BG11 medium and fish processing effluent. The experimental conditions were 200 mg L-1 inoculum, 30 °C, pH 7.6, and C/N ratio 20. Each culture was harvested during the early, mid-log, and late logarithmic growth phase and during the stationary phase and analyzed in terms of total nitrogen, non-protein nitrogen, ammonium nitrogen, nitrate, nitrite, and nucleic acid. It can be said that in all cultures the ammonium ion and the nucleic acids account for great portion of the non-protein nitrogen in the biomass. The results show that the culture medium influences the nitrogen content, and that the Kjeldahl method overestimates the real protein concentration in cyanobacteria.

  20. Determinação de zinco da sola do casco de bovinos leiteiros com ou sem lesões podais, suplementados ou não com levedura seca de cana-de-açúcar Evaluation of hoof sole zinc concentration of dairy cow with and without foot lesions, suplemented or not with drought yeast from sugarcane

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo Pardo

    2004-10-01

    Full Text Available Com o objetivo de estudar as concentrações de zinco da sola do casco de bovinos com e sem lesões podais, suplementados ou não com levedura seca, foram selecionadas e examinadas 60 vacas, escolhidas aleatoriamente, de um rebanho de 150 animais. Formaram-se quatro grupos de 15 animais, sendo o primeiro com animais com lesões podais e suplementados com levedura, o segundo com animais com lesões podais e sem suplementação de levedura, o terceiro com animais sem lesões podais e suplementados com levedura e o quarto com animais sem lesões podais e sem a suplementação de levedura. As concentrações de zinco da sola do casco foram determinadas por espectrometria de absorção atômica com chama (AAS. A comparação estatística das concentrações de zinco nas amostras foram submetidos à análise de variância, seguida pelo teste de Tukey, para comparação de médias. As médias das concentrações de zinco da sola do casco dos animais dos quatro grupos, quando comparadas estatisticamente, apresentaram diferença estatística significativa, somente nos animais com lesões podais e suplementados com levedura.With the goal of studying the hoof sole zinc concentrations of cow with and without foot lesions, suplemented or not with dried yeast from sugarcane; 60 cows were chosen from milking of 150 animals. Four groups of 15 animals were formed being the first one of animals with foot lesions and with supplemental yeast, the second one of animals with lesions and without supplemental yeast, the third group of animals without foot lesions and with supplemental yeast and the fourth one of animals without foot lesions and without supplemental yeast. Hoof sole zinc was determined by the Atomic Absortion Spectrophotometry (AAS. The results were statistically evaluated by analysis of variable, followed by Tukey’s test to compare mean levels. The mean concentration of zinc in the hoof sole of the groups statistically, significant showed differences

  1. Extracellular thiol-assisted selenium uptake dependent on the x(c)(-) cystine transporter explains the cancer-specific cytotoxicity of selenite

    DEFF Research Database (Denmark)

    Olm, E.; Fernandes, A. P.; Hebert, C.

    2009-01-01

    The selenium salt selenite (SeO32-) is cytotoxic in low to moderate concentrations, with a remarkable specificity for cancer cells resistant to conventional chemotherapy. Our data show that selenium uptake and accumulation, rather than intracellular events, are crucial to the specific selenite...... cytotoxicity observed in resistant cancer cells. We show that selenium uptake depends on extracellular reduction, and that the extracellular environment is a key factor specific to selenite cytotoxicity. The extracellular reduction is mediated by cysteine, and the efficacy is determined by the uptake...... and sensitivity to selenite cytotoxicity, and highlights the great therapeutic potential in treating multidrug-resistant cancer....

  2. Nutrição mineral, crescimento e teor de óleo essencial da menta em solução nutritiva sob diferentes concentrações de fósforo e épocas de coleta Mineral nutrition, growth and essential oil content of mint in nutrient solution under different phosphorus concentrations

    Directory of Open Access Journals (Sweden)

    Carlos R. Rodrigues

    2004-09-01

    Full Text Available Avaliou-se o efeito de concentrações de P e épocas de coleta sobre o crescimento, nutrição mineral e teor de óleo essencial da menta (Mentha piperita L.. O delineamento experimental foi em blocos casualizados com parcelas subdivididas, em esquema fatorial 2x5, sendo 2 épocas de coleta (65 e 95 dias de cultivo (DC e 5 concentrações de P na solução nutritiva (6; 12; 18; 24 e 30 mg L-1, com 4 repetições. Foi determinada a massa seca de folhas (MSF, caules (MSC, raízes (MSR e total (MST e as relações folha:caule (F:C e parte aérea:raiz (PA:R. Também, foi determinado o teor de óleo essencial em folhas frescas. Os níveis críticos foliares e acúmulo de nutrientes na parte aérea da menta foram estimados por meio da análise química das folhas e caules. As concentrações de P na solução influenciaram o crescimento e a produção de óleo essencial pela menta. Na coleta realizada aos 65 DC, apenas a MSF foi influenciada pelo P, não se observando efeito sobre os teores de óleo essencial. Aos 95 DC, o aumento da concentração de P promoveu aumentos significativos na massa seca das partes e do total da menta e, também, nos teores de óleo essencial, sendo o teor máximo (2,192 dag kg-1 obtido com 19,50 mg L-1 de P. As maiores concentrações de P avaliadas (24 e 30 mg L-1, promoveram aumentos na produção de matéria fresca e seca da parte aérea da menta, mas, reduziram os teores de óleo essencial, devido ao efeito de diluição, não significando, portanto, ganhos de produção de óleo por planta. Os teores foliares dos nutrientes associados ao teor máximo de óleo aos 95 DC foram em g kg-1: N=37,2; =3,9; K=21,2; Ca=9,3; Mg=3,8; S=3,0; e, em mg kg-1: B=35; Cu=8; Fe=323; Mn=145 e Zn=22. A exigência nutricional aos 95 DC relacionada ao teor máximo de óleo essencial seguiu a seqüência: N>K>Ca>P>Mg>S>Fe>Mn>B>Zn>Cu.The effect of P concentrations and harvest period upon the growth, mineral nutrition and essential oil

  3. Evaluation of NORM concentration in water treatment of Pocos de Caldas municipality, MG, Brazil: preliminary results; Avaliacao da presenca de NORM no tratamento de agua do municipio de Pocos de Caldas: resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Adriano Mota; Villegas, Raul A.S.; Fukuma, Henrique Takuji, E-mail: htfukuma@cnen.gov.br, E-mail: adrianomotaferreira@gmail.com [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    NORM is the acronym used to refer to naturally occurring radioactive materials. Besides being objects of study and monitoring such materials can be used as raw material or as by-products or waste of industrial activities. Oil and gas, mining and water treatment are examples of facilities that can handle NORM. In such cases, their concentration at significant levels from the perspective of environmental and occupational radiation protection may occur. This study aims to evaluate the presence of the natural radioactive {sup 238}U and {sup 232}Th series in the treatment of city water elements Pocos de Caldas - MG (water, materials and waste). The study can serve as an indication of the necessity of a more detailed review in the locally and in the country on this radiological issue. (author)

  4. Estudo da conformação de substratos cerâmicos por laminação a partir de suspensões concentradas de alumina Rolling study of ceramic substrates from concentrate alumina suspensions

    Directory of Open Access Journals (Sweden)

    L. F. G. Setz

    2011-12-01

    Full Text Available A produção de substratos cerâmicos por laminação, ou conformação viscoplástica, é interessante, pois minimiza problemas inerentes ao processamento como a aglomeração dos pós. Quando a preparação das massas a serem conformadas por esta técnica é realizada a partir de suspensões estáveis, estes problemas quase inexistem, possibilitando a obtenção de produtos íntegros com microestrutura homogênea. Neste trabalho é apresentado o comportamento reológico das suspensões concentradas e das massas de alumina contendo diferentes teores do espessante/plastificante hidroxipropil metilcelulose (HPMC e também o estudo das variáveis de processo envolvidas na conformação por calandragem. Como resultado deste estudo foi possível obter substratos de alumina calandrados densos, utilizando-se uma suspensão concentrada (60% vol., estabilizada com 0,02% de Viscocrete 20HE e com adição de 1,5%m. de HPMC.The ceramic substrates production by calendering, or viscous plastic processing, is interesting because inherent problems as a powder agglomeration is minimized. When the ceramic pastes shaping for this technique are produced from stabilized suspensions these problems almost inexist. This work presents the concentrate suspensions and pastes with different hydroxypropyl methyl cellulose (HPMC thickener content rheological behaviors. The variables involved in calendering shaping were studied, too. The production of dense alumina substrates shaped by calendaring from concentrate suspensions (60 vol.%, stabilized with 0.02 wt.% Viscocrete 20HE and 1.5 wt.% HPMC is possible.

  5. Efeito do concentrado no desempenho produtivo, reprodutivo e econômico de vacas da raça Holandesa em pastagem de coast-cross Effect of the concentrate on the productive, reproductive and economic performances of Holstein cows on coast-cross pastures

    Directory of Open Access Journals (Sweden)

    D. Vilela

    2007-04-01

    Full Text Available Avaliou-se o desempenho produtivo, reprodutivo e econômico de vacas da raça Holandesa, mantidas em pastagem de capim-coast-cross e suplementadas com 3 ou 6kg de concentrado/vaca/dia. O pastejo foi sob lotação rotacionada, com um dia de ocupação dos piquetes e 25 ou 35 dias de descanso nas épocas de chuvas ou de seca, respectivamente. A produção de leite foi influenciada pela quantidade de suplemento fornecida. Vacas que receberam 6kg de suplemento produziram mais leite (19,1kg/dia do que as que receberam 3kg (15,5kg/dia. O primeiro estro pós-parto ocorreu aos 99,9 e 67,8 dias, respectivamente, pelos métodos de identificação visual e dosagem de progesterona, para vacas suplementadas com 3kg de concentrado, e 72,9 e 54,5 dias para as suplementadas com 6kg; os intervalos de partos, obtidos na mesma ordem dos tratamentos citados, foram de 444,8 e 436,8 dias. O método visual para identificação de estros não foi preciso e comprometeu a rentabilidade da atividade.Productive, reproductive and economic performance of Holstein cows raised on coast-cross pasture and supplemented either 3 or 6kg of concentrate/cow/day were evaluated. Grazing was under rotating with one day of occupation of each feedlot and 25 or 35 days of resting in the rainy or dry seasons, respectively. Milk yield was higher for cows receiving 6kg of concentrate (19.1kg/day than for cows receiving (15.5kg/day. The first post-calving estrous occurred on 99.9 and 67.8 days, respectively, by visual and progesterone dosage methods for cows fed 3kg of concentrate, and 72.9 and 54.5 days for those fed 6kg. The calving intervals were 444.8 and 436.8 days for cows fed 3kg and 6kg of concentrate, respectively. The visual method for estrous detection was not accurate and compromised business profitability.

  6. Salinomicina e semduramicina associadas em diferentes concentrações no controle da eimeriose em frangos de corte Salinomycin and semduramicin in different concentrations on the broilers eimeriosis control

    Directory of Open Access Journals (Sweden)

    Giankleber Strumielo Diniz

    2009-12-01

    Full Text Available O presente estudo teve por objetivo investigar a associação de salinomicina e semduramicina, em diferentes doses, frente à infecção mista controlada de Eimeria acervulina, E. maxima e E. tenella em frangos de corte. Oitocentas aves foram divididas em 5 grupos (T1: ração não medicada; T2: 30 ppm de salinomicina e 12,5 ppm de semduramicina; T3: 30 ppm de salinomicina e 15 ppm de semduramicina; T4: 40 ppm de salinomicina e 12,5 ppm de semduramicina e T5: 40 ppm de salinomicina e 15 ppm de semduramicina e inoculadas aos 15 dias de idade com oocistos esporulados de E. acervulina, E. maxima e E. tenella, em inóculo misto, via ração. Parâmetros produtivos e escore de lesões foram registrados. Todos os grupos tratados apresentaram estatisticamente melhores ganhos de peso cumulativo aos 21 dias de vida. Aos 35 dias de vida, somente o grupo T3 apresentou diferença significativa. A conversão alimentar cumulativa apresentou diferença estatística nos grupos T4 e T5. O tratamento T5 foi mais eficaz no controle de E. tenella. T3 e T5 obtiveram diferenças estatísticas no escore médio de lesão das três espécies. O uso de salinomicina, associada a semduramicina, em baixas doses demonstrou uma opção viável no controle da coccidiose neste experimento.This study aimed to investigate the association of salinomycin and semduramicin, in different doses, against controlled mixed infection of Eimeria acervulina, E. maxima and E. tenella in broiler chickens. Eight hundred birds were divided into 5 groups (T1: not medicated feed; T2: 30 ppm of salinomycin and 12.5 ppm of semduramicin; T3: 30 ppm of salinomycin and 15 ppm of semduramicin; T4: 40 ppm of salinomycin and 12,5 ppm of semduramicin and T5: 40 ppm of salinomycin and 15 ppm of semduramicin and inoculated at 15 days of age with sporulated oocysts of E. acervulina, E. maxima and E. tenella in a mixed suspension, through the feed. Performance data and lesion scores were recorded. All treated

  7. Variação sazonal da concentração de macronutrientes em folhas de diferentes genótipos de aceroleira Seasonal changes of nutrient concentration in leaves of different barbados cherry genotypes

    Directory of Open Access Journals (Sweden)

    Rosiane de Lourdes Silva de Lima

    2007-01-01

    Full Text Available A aceroleira produz durante o ano inteiro, e seus frutos são ricos em vitaminas e sais minerais. Para a obtenção de produções elevadas e frutos de boa qualidade, é necessário conhecer as necessidades nutricionais e as épocas mais apropriadas para a adubação das plantas. Este trabalho, conduzido em área do Campo Experimental da Embrapa Agroindústria Tropical, em Pacajus, Ceará, de dezembro de 1999 a outubro de 2000, teve por objetivo estudar a variação sazonal dos teores de nutrientes (N, P, K, Ca, Mg e S e determinar a época mais indicada para a análise foliar de seis genótipos (P 52, P 66, P 78, P 91, P 93 e P 97 de aceroleira (Malpighia emarginata D.C.. Adotou-se o delineamento de blocos ao acaso, em esquema de parcelas subdivididas no tempo, com 4 repetições e uma planta por unidade experimental. Existem poucas diferenças no teor de macronutrientes das folhas de distintos genótipos de aceroleiras. O mês de dezembro é a época mais apropriada para diagnosticar os teores de macronutrientes em genótipos de aceroleira no Estado do Ceará, pois é o período menos influenciado pela falta ou excesso de chuva ou pela demanda dos órgãos em formação na planta.Plants of Barbados cherry (Malpighia emarginata produces all over the year, and its fruits are rich in vitamins and minerals. In order to obtain good production and high fruit quality it is necessary to know the nutritional need and the suitable season for plant fertilization. Thus, it was carried out an experiment at the EMBRAPA-National Center for Research of Tropical Agro-industry, from December 1999 to October 2000, aiming to study the seasonal changes nutrient (N, P, K, Ca, Mg and S levels, and the suitable period for leaves mineral diagnosis, in six genotypes P 52, P 66, P 78, P 91, P 93 and P 97 and six distinct sampling times. All the 36 treatments (six genotypes evaluated in six harvest times were conducted in a Randomized Completed Block (RCB design with

  8. Extracellular localization of catalase is associated with the transformed state of malignant cells.

    Science.gov (United States)

    Böhm, Britta; Heinzelmann, Sonja; Motz, Manfred; Bauer, Georg

    2015-12-01

    Oncogenic transformation is dependent on activated membrane-associated NADPH oxidase (NOX). However, the resultant extracellular superoxide anions are also driving the NO/peroxynitrite and the HOCl pathway, which eliminates NOX-expressing transformed cells through selective apoptosis induction. Tumor progression is dependent on dominant interference with intercellular apoptosis-inducing ROS signaling through membrane-associated catalase, which decomposes H2O2 and peroxynitrite and oxidizes NO. Particularly, the decomposition of extracellular peroxynitrite strictly requires membrane-associated catalase. We utilized small interfering RNA (siRNA)-mediated knockdown of catalase and neutralizing antibodies directed against the enzyme in combination with challenging H2O2 or peroxynitrite to determine activity and localization of catalase in cells from three distinct steps of multistage oncogenesis. Nontransformed cells did not generate extracellular superoxide anions and only showed intracellular catalase activity. Transformed cells showed superoxide anion-dependent intercellular apoptosis-inducing ROS signaling in the presence of suboptimal catalase activity in their membrane. Tumor cells exhibited tight control of intercellular apoptosis-inducing ROS signaling through a high local concentration of membrane-associated catalase. These data demonstrate that translocation of catalase to the outside of the cell membrane is already associated with the transformation step. A strong local increase in the concentration of membrane-associated catalase is achieved during tumor progression and is controlled by tumor cell-derived H2O2 and by transglutaminase.

  9. Characterization and biological activities of extracellular melanin produced by Schizophyllum commune (Fries).

    Science.gov (United States)

    Arun, G; Eyini, M; Gunasekaran, P

    2015-06-01

    Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment was characterized by biochemical tests and further, confirmed by UV, IR, EPR, NMR and MALDI-TOF Mass Spectra. Extracellular melanin, at 100 μg/ml, showed significant antibacterial activity against Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas fluorescens and antifungal activity against Trichophyton simii and T. rubrum. At a concentration of 50 μg/ml, melanin showed high free radical scavenging activity of DPPH (2,2-diphenyl-1-picrylhydrazyl) indicating its antioxidant potential. It showed concentration dependent inhibition of cell proliferation of Human Epidermoid Larynx Carcinoma Cell Line (HEP-2). This study has demonstrated characterization of melanin from basidiomycetes mushroom fungus, Schizophyllum commune and its applications.

  10. In situ ruminal degradability of dry matter, organic matter and crude protein of some concentrated supplements used in the feeding of bovines/ Degradabilidade ruminal “in situ” da matéria seca, matéria orgânica e proteína bruta de alguns suplementos concentrados usados na alimentação de bovinos

    Directory of Open Access Journals (Sweden)

    Marco Antônio da Rocha

    2005-06-01

    Full Text Available Holstein steers, with permanent ruminal cannula, 650 kg of liveweight, maintained on pasture, and receiving mineral mixture “ad libtum” were used. The present study had the objective of evaluating the “in situ” ruminal degradation of the dry matter (DM, crude protein (CP and organic matter (OM of 12 concentrated feed: whole sunflower seed (WSF, partially degreased sunflower (DSF, sunflower meal (SFM, sunflower pie pressed one time (T 1x, sunflower pie pressed two time (T 2x, for extracting of the oil, whole soybean seed (WS, partially degreased soybean (DS, soybean meal (SM, whole cottonseed (WC, cottonseed meal (CM, degreased corn germ (CG and a commercial concentrate with 36% of CP (CC. The feed were grounded in a mill equipped with a screen with sieves of 2 mm of diameter. Samples 5 g of DM from each one of the mentioned feed were incubated in nylon bags with pores of 50 micras of diameter, measuring 14 x 7 cm, for the times of 12; 20; and 33 h of ruminal fermentation. The effective degradability (ED of CP, for a passage rate of 5%/h varied from 62.08 to 95.93% for commercial concentrate and sunflower pie pressed two time for OM varied from 48.17 to 85.28% for soybean meal and whole cottonseed. The CC and CG presented the smallest ED of CP, however only the CC have larger protein escapes to be digested in the intestines, because CG presents little PB in its constitution.Foram utilizados quatro bovinos da raça holandesa, machos castrados, fistulados no rúmen, pesando em média 650kg, mantidos em pastejo e recebendo mistura mineral “ad libtum”. O presente trabalho teve como objetivo avaliar a degradação ruminal “in situ” da matéria seca (MS, proteína bruta (PB e matéria orgânica (MO de 12 alimentos concentrados: grão de girassol integral (GI, grão de girassol parcialmente desengordurado (GD, farelo de girassol (FG, torta de girassol com uma passagem pela prensa (T 1x, torta de girassol com duas passagens pela prensa (T

  11. Role of serotonin and/or norepinephrine in the MDMA-induced increase in extracellular glucose and glycogenolysis in the rat brain

    OpenAIRE

    Pachmerhiwala, Rashida; Bhide, Nirmal; Straiko, Megan; Gudelsky, Gary A.

    2010-01-01

    The acute administration of MDMA has been shown to promote glycogenolysis and increase the extracellular concentration of glucose in the striatum. In the present study the role of serotonergic and/or noradrenergic mechanisms in the MDMA-induced increase in extracellular glucose and glycogenolysis was assessed. The relationship of these responses to the hyperthermia produced by MDMA also was examined. The administration of MDMA (10 mg/kg, i.p.) resulted in a significant and sustained increase ...

  12. Taxas de passagem e cinética da degradação ruminal em bezerros holandeses alimentados com dietas contendo diferentes níveis de concentrado Passage rates and ruminal degradation kinetics in Holstein calves fed diets with different concentrate levels

    Directory of Open Access Journals (Sweden)

    Peter Johann Bürger

    2000-02-01

    Full Text Available RESUMO - Este trabalho foi realizado para avaliar os efeitos de diferentes níveis de concentrado sobre as taxas de passagem de fluidos, usando Co-EDTA, e partículas, usando cloreto de Iterbio e Cr-mordante e, a cinética da degradação ruminal in situ da matéria seca (MS e da proteína bruta (PB. Cinco bezerros holandeses, inteiros, fistulados no rúmen e abomaso, com idade de 5,8±0,7 meses e de e 107,4±11,0 kg PV médio inicial, foram distribuídos a um delineamento em quadrado latino 5x5 (tratamento x período. Os animais foram alojados em baias individuais e alimentados à vontade com dietas contendo 30,0; 45,0; 60,0; 75,0; e 90,0% de concentrado, com base na MS, em rações contendo como volumoso, o feno de capim coast-cross e no concentrado, o farelo de sojae , fubá de milho. A taxa de passagem de fluidos apresentou comportamento quadrático, estimando-se o valor máximo de 9,73%/h, com nível de 61,99% de concentrado na ração. A taxa de passagem de partículas do farelo de soja no retículo-rúmen- diminuiu linearmente, enquanto no ceco-cólon proximal não foi influenciada pelos níveis de concentrado na rações. As taxas de passagem do feno de capim coast-cross no rúmen-retículo e no ceco-cólon proximal não foram influenciadas pelo aumento no nível de concentrado nas rações. A degradação efetiva da MS do farelo de soja não foi influenciada, enquanto a do fubá de milho aumentou e do feno de capim coast-cross reduziu linearmente, respectivamente. A degradação efetiva da PB do farelo de soja e do feno de capim coast-cross não variou, porém a do fubá de milho aumentou linearmente, com o aumento dos níveis de concentrado nas rações.ABSTRACT - This work was conducted to evaluate the effects of different concentrate levels on the liquid passage rates, using Co-EDTA, and particulate, using ytterbium chloride and Cr-mordant, and the in situ ruminal degradation kinetics of dry matter (DM and crude protein (CP. Five

  13. Effects of bacterial cells and two types of extracellular polymers on bioclogging of sand columns

    Science.gov (United States)

    Xia, Lu; Zheng, Xilai; Shao, Haibing; Xin, Jia; Sun, Zhaoyue; Wang, Leyun

    2016-04-01

    Microbially induced reductions in the saturated hydraulic conductivity, Ks, of natural porous media, conventionally called bioclogging, occurs frequently in natural and engineered subsurface systems. Bioclogging can affect artificial groundwater recharge, in situ bioremediation of contaminated aquifers, or permeable reactive barriers. In this study, we designed a series of percolation experiments to simulate the growth and metabolism of bacteria in sand columns. The experimental results showed that the bacterial cell amount gradually increased to a maximum of 8.91 log10 CFU/g sand at 144 h during the bioclogging process, followed by a decrease to 7.89 log10 CFU/g sand until 336 h. The same variation pattern was found for the concentration of tightly bound extracellular polymeric substances (TB-EPS), which had a peak value of 220.76 μg/g sand at 144 h. In the same experiments, the concentration of loosely bound extracellular polymeric substances (LB-EPS) increased sharply from 54.45 to 575.57 μg/g sand in 192 h, followed by a slight decline to 505.04 μg/g sand. The increase of the bacterial cell amount along with the other two concentrations could reduce the Ks of porous media, but their relative contributions varied to a large degree during different percolation stages. At the beginning of the tests (e.g., 48 h before), bacterial cells were likely responsible for the Ks reduction of porous media because no increase was found for the other two concentrations. With the accumulation of cells and EPS production from 48 to 144 h, both were important for the reduction of Ks. However, in the late period of percolation tests from 144 to 192 h, LB-EPS was probably responsible for the further reduction of Ks, as the bacterial cell amount and TB-EPS concentration decreased. Quantitative contributions of bacterial cell amount and the two types of extracellular polymers to Ks reductions were also evaluated.

  14. Tailoring material properties of a nanofibrous extracellular matrix derived hydrogel

    Science.gov (United States)

    Johnson, Todd D.; Lin, Stephen Y.; Christman, Karen L.

    2011-12-01

    In the native tissue, the interaction between cells and the extracellular matrix (ECM) is essential for cell migration, proliferation, differentiation, mechanical stability, and signaling. It has been shown that decellularized ECMs can be processed into injectable formulations, thereby allowing for minimally invasive delivery. Upon injection and increase in temperature, these materials self-assemble into porous gels forming a complex network of fibers with nanoscale structure. In this study we aimed to examine and tailor the material properties of a self-assembling ECM hydrogel derived from porcine myocardial tissue, which was developed as a tissue specific injectable scaffold for cardiac tissue engineering. The impact of gelation parameters on ECM hydrogels has not previously been explored. We examined how modulating pH, temperature, ionic strength, and concentration affected the nanoscale architecture, mechanical properties, and gelation kinetics. These material characteristics were assessed using scanning electron microscopy, rheometry, and spectrophotometry, respectively. Since the main component of the myocardial matrix is collagen, many similarities between the ECM hydrogel and collagen gels were observed in terms of the nanofibrous structure and modulation of properties by altering ionic strength. However, variation from collagen gels was noted for the gelation temperature along with varied times and rates of gelation. These discrepancies when compared to collagen are likely due to the presence of other ECM components in the decellularized ECM based hydrogel. These results demonstrate how the material properties of ECM hydrogels could be tailored for future in vitro and in vivo applications.

  15. Substrate dependent production of extracellular biosurfactant by a marine bacterium.

    Science.gov (United States)

    Das, Palashpriya; Mukherjee, Soumen; Sen, Ramkrishna

    2009-01-01

    The potential of a marine microorganism to utilize different carbon substrates for the production of an extracellular biosurfactant was evaluated. Among the several carbon substrates tested for this purpose, production of the crude biosurfactant was found to be highest with glycerol (2.9+/-0.11 g L(-1)) followed by starch (2.5+/-0.11 g L(-1)), glucose (1.16+/-0.11 g L(-1)) and sucrose (0.94+/-0.07 g L(-1)). The crude biosurfactant obtained from glycerol, starch and sucrose media had significantly higher antimicrobial action than those obtained from glucose containing medium. RP-HPLC resolved the crude biosurfactants into several fractions one of which had significant antimicrobial action. The antimicrobial fraction was found in higher concentrations in biosurfactant obtained using glycerol, starch and sucrose as compared to the biosurfactants from glucose medium, thereby explaining higher antimicrobial activity. The carbon substrate was thus found to affect biosurfactant production both in a qualitative and quantitative manner.

  16. The extracellular matrix in breast cancer.

    Science.gov (United States)

    Insua-Rodríguez, Jacob; Oskarsson, Thordur

    2016-02-01

    The extracellular matrix (ECM) is increasingly recognized as an important regulator in breast cancer. ECM in breast cancer development features numerous changes in composition and organization when compared to the mammary gland under homeostasis. Matrix proteins that are induced in breast cancer include fibrillar collagens, fibronectin, specific laminins and proteoglycans as well as matricellular proteins. Growing evidence suggests that many of these induced ECM proteins play a major functional role in breast cancer progression and metastasis. A number of the induced ECM proteins have moreover been shown to be essential components of metastatic niches, promoting stem/progenitor signaling pathways and metastatic growth. ECM remodeling enzymes are also markedly increased, leading to major changes in the matrix structure and biomechanical properties. Importantly, several ECM components and ECM remodeling enzymes are specifically induced in breast cancer or during tissue regeneration while healthy tissues under homeostasis express exceedingly low levels. This may indicate that ECM and ECM-associated functions may represent promising drug targets against breast cancer, providing important specificity that could be utilized when developing therapies. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. PREPARATION AND PROPERTIES OF EXTRACELLULAR BIOPOLYMER FLOCCULANT

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The biopolymer flocculant (named PS-2) producing by Pseudomonas fluorescens was investigated. The PS-2 had high efficiency with small dosage, when dealing with kaolin suspension, formed larger floc, with big sedimentation rate, over a wide range of temperatures. Distributing of flocculating activity test showed that the biopolymer flocculant was an extracellular product. The composition analysis of purified biopolymer flocculant showed that it composed mainly of polysaccharide and nucleic acid. The content of polysaccharide was 86.7%, which determined by using phenol-vitriol method, and the content of nucleic acid was 7.8%, which determined by UV absorption method. The biopolymer flocculant as a powder form showed much better stability than that as a supernatant. The character of biopolymer flocculant was stable even it was heated to 100℃ when it in acidic condition. The optimal conditions to flocculate kaolin suspension were as follows: pH 8~12, flocculant dosage 1mL/L, and Ca2+ as the optimal cation.

  18. Bacterial Extracellular Polysaccharides Involved in Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Elena P. Ivanova

    2009-07-01

    Full Text Available Extracellular polymeric substances (EPS produced by microorganisms are a complex mixture of biopolymers primarily consisting of polysaccharides, as well as proteins, nucleic acids, lipids and humic substances. EPS make up the intercellular space of microbial aggregates and form the structure and architecture of the biofilm matrix. The key functions of EPS comprise the mediation of the initial attachment of cells to different substrata and protection against environmental stress and dehydration. The aim of this review is to present a summary of the current status of the research into the role of EPS in bacterial attachment followed by biofilm formation. The latter has a profound impact on an array of biomedical, biotechnology and industrial fields including pharmaceutical and surgical applications, food engineering, bioremediation and biohydrometallurgy. The diverse structural variations of EPS produced by bacteria of different taxonomic lineages, together with examples of biotechnological applications, are discussed. Finally, a range of novel techniques that can be used in studies involving biofilm-specific polysaccharides is discussed.

  19. PREPARATION AND PROPERTIES OF EXTRACELLULAR BIOPOLYMER FLOCCULANT

    Institute of Scientific and Technical Information of China (English)

    LI Chunxiang; LIU Binbin; XIONG Jinshui; YAN Jingchun

    2007-01-01

    The biopolymer flocculant (named PS-2) producing by Pseudomonas fluorescens was investigated. The PS-2 had high efficiency with small dosage, when dealing with kaolin suspension,formed larger floc, with big sedimentation rate, over a wide range of temperatures. Distributing of flocculating activity test showed that the biopolymer flocculant was an extracellular product. The composition analysis of purified biopolymer flocculant showed that it composed mainly of polysaccharide and nucleic acid. The content of polysaccharide was 86.7%, which determined by using phenol-vitriol method, and the content of nucleic acid was 7.8%, which determined by UV absorption method. The biopolymer flocculant as a powder form showed much better stability than that as a supernatant. The character of biopolymer flocculant was stable even it was heated to 100 ℃ when it in acidic condition. The optimal conditions to flocculate kaolin suspension were as follows:pH 8~12, flocculant dosage 1mL/L, and Ca2+ as the optimal cation.

  20. Getting to know the extracellular vesicle glycome.

    Science.gov (United States)

    Gerlach, Jared Q; Griffin, Matthew D

    2016-04-01

    Extracellular vesicles (EVs) are a diverse population of complex biological particles with diameters ranging from approximately 20 to 1000 nm. Tremendous interest in EVs has been generated following a number of recent, high-profile reports describing their potential utility in diagnostic, prognostic, drug delivery, and therapeutic roles. Subpopulations, such as exosomes, are now known to directly participate in cell-cell communication and direct material transfer. Glycomics, the 'omic' portion of the glycobiology field, has only begun to catalog the surface oligosaccharide and polysaccharide structures and also the carbohydrate-binding proteins found on and inside EVs. The EV glycome undoubtedly contains vital clues essential to better understanding the function, biogenesis, release and transfer of vesicles, however getting at this information is technically challenging and made even more so because of the small physical size of the vesicles and the typically minute yield from physiological-scale biological samples. Vesicle micro-heterogeneity which may be related to specific vesicle origins and functions presents a further challenge. A number of primary studies carried out over the past decade have turned up specific and valuable clues regarding the composition and roles of glycan structures and also glycan binding proteins involved EV biogenesis and transfer. This review explores some of the major EV glycobiological research carried out to date and discusses the potential implications of these findings across the life sciences.

  1. Extracellular Vesicles: potential roles in Regenerative Medicine

    Directory of Open Access Journals (Sweden)

    Olivier G de Jong

    2014-12-01

    Full Text Available Extracellular vesicles (EV consist of exosomes, which are released upon fusion of the multivesicular body with the cell membrane, and microvesicles, which are released directly from the cell membrane. EV can mediate cell-cell communication and are involved in many processes, including immune signaling, angiogenesis, stress response, senescence, proliferation, and cell differentiation. The vast amount of processes that EV are involved in and the versatility of manner in which they can influence the behavior of recipient cells make EV an interesting source for both therapeutic and diagnostic applications. Successes in the fields of tumor biology and immunology sparked the exploration of the potential of EV in the field of regenerative medicine. Indeed, EV are involved in restoring tissue and organ damage, and may partially explain the paracrine effects observed in stem cell based therapeutic approaches. The function and content of EV may also harbor information that can be used in tissue engineering, in which paracrine signaling is employed to modulate cell recruitment, differentiation, and proliferation. In this review, we discuss the function and role of EV in regenerative medicine and elaborate on potential applications in tissue engineering.

  2. Tumorigenic Potential of Extracellular Matrix Metalloproteinase Inducer

    Science.gov (United States)

    Zucker, Stanley; Hymowitz, Michelle; Rollo, Ellen E.; Mann, Richard; Conner, Cathleen E.; Cao, Jian; Foda, Hussein D.; Tompkins, David C.; Toole, Bryan P.

    2001-01-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN), a glycoprotein present on the cancer cell plasma membrane, enhances fibroblast synthesis of matrix metalloproteinases (MMPs). The demonstration that peritumoral fibroblasts synthesize most of the MMPs in human tumors rather than the cancer cells themselves has ignited interest in the role of EMMPRIN in tumor dissemination. In this report we have demonstrated a role for EMMPRIN in cancer progression. Human MDA-MB-436 breast cancer cells, which are tumorigenic but slow growing in vivo, were transfected with EMMPRIN cDNA and injected orthotopically into mammary tissue of female NCr nu/nu mice. Green fluorescent protein was used to visualize metastases. In three experiments, breast cancer cell clones transfected with EMMPRIN cDNA were considerably more tumorigenic and invasive than plasmid-transfected cancer cells. Increased gelatinase A and gelatinase B expression (demonstrated by in situ hybridization and gelatin substrate zymography) was demonstrated in EMMPRIN-enhanced tumors. In contrast to de novo breast cancers in humans, human tumors transplanted into mice elicited minimal stromal or inflammatory cell reactions. Based on these experimental studies and our previous demonstration that EMMPRIN is prominently displayed in human cancer tissue, we propose that EMMPRIN plays an important role in cancer progression by increasing synthesis of MMPs. PMID:11395366

  3. Analysis of extracellular RNA in cerebrospinal fluid

    Science.gov (United States)

    Saugstad, Julie A.; Lusardi, Theresa A.; Van Keuren-Jensen, Kendall R.; Phillips, Jay I.; Lind, Babett; Harrington, Christina A.; McFarland, Trevor J.; Courtright, Amanda L.; Reiman, Rebecca A.; Yeri, Ashish S.; Kalani, M. Yashar S.; Adelson, P. David; Arango, Jorge; Nolan, John P.; Duggan, Erika; Messer, Karen; Akers, Johnny C.; Galasko, Douglas R.; Quinn, Joseph F.; Carter, Bob S.; Hochberg, Fred H.

    2017-01-01

    ABSTRACT We examined the extracellular vesicle (EV) and RNA composition of pooled normal cerebrospinal fluid (CSF) samples and CSF from five major neurological disorders: Alzheimer’s disease (AD), Parkinson’s disease (PD), low-grade glioma (LGG), glioblastoma multiforme (GBM), and subarachnoid haemorrhage (SAH), representing neurodegenerative disease, cancer, and severe acute brain injury. We evaluated: (I) size and quantity of EVs by nanoparticle tracking analysis (NTA) and vesicle flow cytometry (VFC), (II) RNA yield and purity using four RNA isolation kits, (III) replication of RNA yields within and between laboratories, and (IV) composition of total and EV RNAs by reverse transcription–quantitative polymerase chain reaction (RT-qPCR) and RNA sequencing (RNASeq). The CSF contained ~106 EVs/μL by NTA and VFC. Brain tumour and SAH CSF contained more EVs and RNA relative to normal, AD, and PD. RT-qPCR and RNASeq identified disease-related populations of microRNAs and messenger RNAs (mRNAs) relative to normal CSF, in both total and EV fractions. This work presents relevant measures selected to inform the design of subsequent replicative CSF studies. The range of neurological diseases highlights variations in total and EV RNA content due to disease or collection site, revealing critical considerations guiding the selection of appropriate approaches and controls for CSF studies. PMID:28717417

  4. Extracellular Vesicles and Autophagy in Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Tianyang Gao

    2016-01-01

    Full Text Available Osteoarthritis (OA is a type of chronic joint disease that is characterized by the degeneration and loss of articular cartilage and hyperplasia of the synovium and subchondral bone. There is reasonable knowledge about articular cartilage physiology, biochemistry, and chondrocyte metabolism. However, the etiology and pathogenesis of OA remain unclear and need urgent clarification to guide the early diagnosis and treatment of OA. Extracellular vesicles (EVs are small membrane-linking particles that are released from cells. In recent decades, several special biological properties have been found in EV, especially in terms of cartilage. Autophagy plays a critical role in the regulation of cellular homeostasis. Likewise, more and more research has gradually focused on the effect of autophagy on chondrocyte proliferation and function in OA. The synthesis and release of EV are closely associated with autophagy. At the same time, both EV and autophagy play a role in OA development. Based on the mechanism of EV and autophagy in OA development, EV may be beneficial in the early diagnosis of OA; on the other hand, the combination of EV and autophagy-related regulatory drugs may provide insight into possible OA therapeutic strategies.

  5. Relevance of extracellular DNA in rhizosphere

    Science.gov (United States)

    Pietramellara, Giacomo; Ascher, Judith; Baraniya, Divyashri; Arfaioli, Paola; Ceccherini, Maria Teresa; Hawes, Martha

    2013-04-01

    One of the most promising areas for future development is the manipulation of the rhizosphere to produce sustainable and efficient agriculture production systems. Using Omics approaches, to define the distinctive features of eDNA systems and structures, will facilitate progress in rhizo-enforcement and biocontrol studies. The relevance of these studies results clear when we consider the plethora of ecological functions in which eDNA is involved. This fraction can be actively extruded by living cells or discharged during cellular lysis and may exert a key role in the stability and variability of the soil bacterial genome, resulting also a source of nitrogen and phosphorus for plants due to the root's capacity to directly uptake short DNA fragments. The adhesive properties of the DNA molecule confer to eDNA the capacity to inhibit or kill pathogenic bacteria by cation limitation induction, and to facilitate formation of biofilm and extracellular traps (ETs), that may protect microorganisms inhabiting biofilm and plant roots against pathogens and allelopathic substances. The ETs are actively extruded by root border cells when they are dispersed in the rhizosphere, conferring to plants the capacity to extend an endogenous pathogen defence system outside the organism. Moreover, eDNA could be involved in rhizoremediation in heavy metal polluted soil acting as a bioflotation reagent.

  6. Engineering hydrogels as extracellular matrix mimics.

    Science.gov (United States)

    Geckil, Hikmet; Xu, Feng; Zhang, Xiaohui; Moon, SangJun; Demirci, Utkan

    2010-04-01

    Extracellular matrix (ECM) is a complex cellular environment consisting of proteins, proteoglycans, and other soluble molecules. ECM provides structural support to mammalian cells and a regulatory milieu with a variety of important cell functions, including assembling cells into various tissues and organs, regulating growth and cell-cell communication. Developing a tailored in vitro cell culture environment that mimics the intricate and organized nanoscale meshwork of native ECM is desirable. Recent studies have shown the potential of hydrogels to mimic native ECM. Such an engineered native-like ECM is more likely to provide cells with rational cues for diagnostic and therapeutic studies. The research for novel biomaterials has led to an extension of the scope and techniques used to fabricate biomimetic hydrogel scaffolds for tissue engineering and regenerative medicine applications. In this article, we detail the progress of the current state-of-the-art engineering methods to create cell-encapsulating hydrogel tissue constructs as well as their applications in in vitro models in biomedicine.

  7. Overview of Extracellular Microvesicles in Drug Metabolism

    Science.gov (United States)

    Conde-Vancells, Javier; Gonzalez, Esperanza; Lu, Shelly C.; Mato, Jose M.; Falcon-Perez, Juan M.

    2010-01-01

    Importance of the field Liver is the major body reservoir for enzymes involved in the metabolism of endogenous and xenobiotic compounds. Recently, it has been shown that hepatocytes release exosome-like vesicles to the extracellular medium, and the proteomic characterization of these hepatocyte-secreted exosomes has revealed the presence of several of these enzymes on them. Areas covered in this review A systematic bibliographic search focus on two related aspects: 1) xenobiotic-metabolizing enzymes that have been detected in microvesicles, and 2) microvesicles which are in the blood stream or secreted by cell-types with clear interactions with this fluid. What the reader will gain A discussion of these hepatocyte-secreted vesicles along with others microvesicles as enzymatic carriers in the context of extrahepatic drug-metabolizing systems. Take home message The contribution of many tissues including the liver to the microvesicles plasma population is supported by several reports. On the other hand, many enzymes involved in the metabolism of drugs have been detected in microvesicles. Together, these observations argue positively through a role of hepatic-microvesicles in spreading the liver metabolizing activities through the body contributing in this manner to extrahepatic drug metabolism systems what could be relevant for body homeostasis and pharmaceutical interests. PMID:20192903

  8. Extracellular ice phase transitions in insects.

    Science.gov (United States)

    Hawes, T C

    2014-01-01

    At temperatures below their temperature of crystallization (Tc), the extracellular body fluids of insects undergo a phase transition from liquid to solid. Insects that survive the transition to equilibrium (complete freezing of the body fluids) are designated as freeze tolerant. Although this phenomenon has been reported and described in many Insecta, current nomenclature and theory does not clearly delineate between the process of transition (freezing) and the final solid phase itself (the frozen state). Thus freeze tolerant insects are currently, by convention, described in terms of the temperature at which the crystallization of their body fluids is initiated, Tc. In fact, the correct descriptor for insects that tolerate freezing is the temperature of equilibrium freezing, Tef. The process of freezing is itself a separate physical event with unique physiological stresses that are associated with ice growth. Correspondingly there are a number of insects whose physiological cryo-limits are very specifically delineated by this transitional envelope. The distinction also has considerable significance for our understanding of insect cryobiology: firstly, because the ability to manage endogenous ice growth is a fundamental segregator of cryotype; and secondly, because our understanding of internal ice management is still largely nascent.

  9. Protein Dynamics in the Plant Extracellular Space

    Science.gov (United States)

    Guerra-Guimarães, Leonor; Pinheiro, Carla; Chaves, Inês; Barros, Danielle R.; Ricardo, Cândido P.

    2016-01-01

    The extracellular space (ECS or apoplast) is the plant cell compartment external to the plasma membrane, which includes the cell walls, the intercellular space and the apoplastic fluid (APF). The present review is focused on APF proteomics papers and intends to draw information on the metabolic processes occurring in the ECS under abiotic and biotic stresses, as well as under non-challenged conditions. The large majority of the proteins detected are involved in “cell wall organization and biogenesis”, “response to stimulus” and “protein metabolism”. It becomes apparent that some proteins are always detected, irrespective of the experimental conditions, although with different relative contribution. This fact suggests that non-challenged plants have intrinsic constitutive metabolic processes of stress/defense in the ECS. In addition to the multiple functions ascribed to the ECS proteins, should be considered the interactions established between themselves and with the plasma membrane and its components. These interactions are crucial in connecting exterior and interior of the cell, and even simple protein actions in the ECS can have profound effects on plant performance. The proteins of the ECS are permanently contributing to the high dynamic nature of this plant compartment, which seems fundamental to plant development and adaptation to the environmental conditions. PMID:28248232

  10. Micro- and macrorheology of jellyfish extracellular matrix.

    Science.gov (United States)

    Gambini, Camille; Abou, Bérengère; Ponton, Alain; Cornelissen, Annemiek J M

    2012-01-04

    Mechanical properties of the extracellular matrix (ECM) play a key role in tissue organization and morphogenesis. Rheological properties of jellyfish ECM (mesoglea) were measured in vivo at the cellular scale by passive microrheology techniques: microbeads were injected in jellyfish ECM and their Brownian motion was recorded to determine the mechanical properties of the surrounding medium. Microrheology results were compared with macrorheological measurements performed with a shear rheometer on slices of jellyfish mesoglea. We found that the ECM behaved as a viscoelastic gel at the macroscopic scale and as a much softer and heterogeneous viscoelastic structure at the microscopic scale. The fibrous architecture of the mesoglea, as observed by differential interference contrast and scanning electron microscopy, was in accord with these scale-dependent mechanical properties. Furthermore, the evolution of the mechanical properties of the ECM during aging was investigated by measuring microrheological properties at different jellyfish sizes. We measured that the ECM in adult jellyfish was locally stiffer than in juvenile ones. We argue that this stiffening is a consequence of local aggregations of fibers occurring gradually during aging of the jellyfish mesoglea and is enhanced by repetitive muscular contractions of the jellyfish.

  11. Characterization and biological role of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Aneta Wójtowicz

    2014-12-01

    Full Text Available Extracellular vesicles (EV form a heterogeneous population of mostly spherical membrane structures released by almost all cells, including tumour cells, both in vivo and in vitro. Their size varies from 30 nm to 1 μm, and size is one of the main criteria of the selection of two categories of EV: small (30-100 nm, more homogeneous exosomes and larger fragments (0.1-1 μm called membrane microvesicles or ectosomes. The presence of EV has already been detected in many human body fluids: blood, urine, saliva, semen and amniotic fluid. Formation of EV is tightly controlled, and their function and biochemical composition depend on the cell type they originate from. EV are the “vehicles” of bioactive molecules, such as proteins, mRNA and microRNA, and may play an important role in intercellular communication and modulation of e.g. immune system cell activity. In addition, on the surface of tumour-derived microvesicles (TMV, called oncosomes, several markers specific for cancer cells were identified, which indicates a role of TMV in tumour growth and cancer development. On the other hand, TMV may be an important source of tumour-associated antigens (TAA which can be potentially useful as biomarkers with prognostic value, as well as in development of new forms of targeted immunotherapy of cancer.

  12. Routes and mechanisms of extracellular vesicle uptake

    Directory of Open Access Journals (Sweden)

    Laura Ann Mulcahy

    2014-08-01

    Full Text Available Extracellular vesicles (EVs are small vesicles released by donor cells that can be taken up by recipient cells. Despite their discovery decades ago, it has only recently become apparent that EVs play an important role in cell-to-cell communication. EVs can carry a range of nucleic acids and proteins which can have a significant impact on the phenotype of the recipient. For this phenotypic effect to occur, EVs need to fuse with target cell membranes, either directly with the plasma membrane or with the endosomal membrane after endocytic uptake. EVs are of therapeutic interest because they are deregulated in diseases such as cancer and they could be harnessed to deliver drugs to target cells. It is therefore important to understand the molecular mechanisms by which EVs are taken up into cells. This comprehensive review summarizes current knowledge of EV uptake mechanisms. Cells appear to take up EVs by a variety of endocytic pathways, including clathrin-dependent endocytosis, and clathrin-independent pathways such as caveolin-mediated uptake, macropinocytosis, phagocytosis, and lipid raft–mediated internalization. Indeed, it seems likely that a heterogeneous population of EVs may gain entry into a cell via more than one route. The uptake mechanism used by a given EV may depend on proteins and glycoproteins found on the surface of both the vesicle and the target cell. Further research is needed to understand the precise rules that underpin EV entry into cells.

  13. Mechanics of composite cytoskeletal and extracellular networks

    Science.gov (United States)

    Das, Moumita

    2014-03-01

    Living cells sense and respond to mechanical forces in their surroundings. This mechanical response is mainly due to the cell cytoskeleton, and its interaction with the extracellular matrix (ECM). The cell cytoskeleton is a composite polymeric scaffold made of many different types of protein filaments and crosslinking proteins. Two major filament systems in the cytoskeleton are actin filaments (F-actin) and microtubules (MTs). Actin filaments are semiflexible, while the much stiffer MTs behave as rigid rods. I shall discuss theories that help understand how the direct coupling to the surrounding F-actin matrix allows intracellular MTs to bear large compressive forces and controls the range of force transmission along the MTs, and how the MTs not only enhance the stiffness of the cell cytoskeleton, but can also dramatically endow an initially nearly incompressible F-actin matrix with enhanced compressibility relative to its shear compliance. A second source of compositeness in the cytoskeleton is the presences of different types of crosslinkers that can interact cooperatively leading to enhanced mechanical rigidity and tunable response. Like the cytoskeleton, the ECM is also a polymeric composite. It is primarily composed of a mesh of fibrous proteins, mainly stiff collagen filaments, and a comparatively flexible gel of proteoglycans and hyaluronan. I shall discuss a model that shows how the interplay between the collagen network and the background elastic gel leads to a mechanically robust ECM.

  14. Extracellular matrix components in peripheral nerve regeneration.

    Science.gov (United States)

    Gonzalez-Perez, Francisco; Udina, Esther; Navarro, Xavier

    2013-01-01

    Injured axons of the peripheral nerve are able to regenerate and, eventually, reinnervate target organs. However, functional recovery is usually poor after severe nerve injuries. The switch of Schwann cells to a proliferative state, secretion of trophic factors, and the presence of extracellular matrix (ECM) molecules (such as collagen, laminin, or fibronectin) in the distal stump are key elements to create a permissive environment for axons to grow. In this review, we focus attention on the ECM components and their tropic role in axonal regeneration. These components can also be used as molecular cues to guide the axons through artificial nerve guides in attempts to better mimic the natural environment found in a degenerating nerve. Most used scaffolds tested are based on natural molecules that form the ECM, but use of synthetic polymers and functionalization of hydrogels are bringing new options. Progress in tissue engineering will eventually lead to the design of composite artificial nerve grafts that may replace the use of autologous nerve grafts to sustain regeneration over long gaps.

  15. Role of Extracellular Vesicles in Hematological Malignancies

    Directory of Open Access Journals (Sweden)

    Stefania Raimondo

    2015-01-01

    Full Text Available In recent years the role of tumor microenvironment in the progression of hematological malignancies has been widely recognized. Recent studies have focused on how cancer cells communicate within the microenvironment. Among several factors (cytokines, growth factors, and ECM molecules, a key role has been attributed to extracellular vesicles (EV, released from different cell types. EV (microvesicles and exosomes may affect stroma remodeling, host cell functions, and tumor angiogenesis by inducing gene expression modulation in target cells, thus promoting cancer progression and metastasis. Microvesicles and exosomes can be recovered from the blood and other body fluids of cancer patients and contain and deliver genetic and proteomic contents that reflect the cell of origin, thus constituting a source of new predictive biomarkers involved in cancer development and serving as possible targets for therapies. Moreover, due to their specific cell-tropism and bioavailability, EV can be considered natural vehicles suitable for drug delivery. Here we will discuss the recent advances in the field of EV as actors in hematological cancer progression, pointing out the role of these vesicles in the tumor-host interplay and in their use as biomarkers for hematological malignancies.

  16. The NIH Extracellular RNA Communication Consortium

    Directory of Open Access Journals (Sweden)

    Alexandra M. Ainsztein

    2015-08-01

    Full Text Available The Extracellular RNA (exRNA Communication Consortium, funded as an initiative of the NIH Common Fund, represents a consortium of investigators assembled to address the critical issues in the exRNA research arena. The overarching goal is to generate a multi-component community resource for sharing fundamental scientific discoveries, protocols, and innovative tools and technologies. The key initiatives include (a generating a reference catalogue of exRNAs present in body fluids of normal healthy individuals that would facilitate disease diagnosis and therapies, (b defining the fundamental principles of exRNA biogenesis, distribution, uptake, and function, as well as development of molecular tools, technologies, and imaging modalities to enable these studies, (c identifying exRNA biomarkers of disease, (d demonstrating clinical utility of exRNAs as therapeutic agents and developing scalable technologies required for these studies, and (e developing a community resource, the exRNA Atlas, to provide the scientific community access to exRNA data, standardized exRNA protocols, and other useful tools and technologies generated by funded investigators.

  17. Use of LabSOCS for determination of specific concentrations of {sup 40}K, {sup 238}U and {sup 232}Th in fertilizer samples; Uso de LabSOCS no calculo da eficiencia de detecao para determinacao da concentracao especifica de {sup 40}K, {sup 238}U e {sup 232}Th em amostras de fertilizantes

    Energy Technology Data Exchange (ETDEWEB)

    Garcez, Ricardo Washington Dutra; Lopes, Jose Marques; Silva, Ademir Xavier da, E-mail: rgarcez@con.ufrj.br, E-mail: marqueslopez@yahoo.com.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Domingues, Alessandro Mariano; Lima, Marco Frota, E-mail: slessandrodomingues@fisica.if.uff.br, E-mail: marcofrotalima@yahoo.com.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Biologia

    2015-07-01

    Use of fertilizer is an established practice worldwide to promote agricultural productivity increased without increasing the planted area, resulting in native forests protection and increase of the food availability. Some kinds of fertilizer have in their chemical composition some radionuclides due the origin of its feedstock, such as {sup 238}U, the {sup 232}Th, and their descendants, beyond {sup 40}K. Knowledge of the radioactivity levels in the environment is great importance to know the gamma radiation dose that the human being is exposed. For identification and quantitation of radionuclides, it was used gamma spectrometry where HPGe detector was used to obtain the spectra, and LabSOCS software for calculating the detection efficiency for each energy. The values of {sup 232}Th specific concentrations ranged from 4.1 to 368.1 Bq.Kg{sup -1} , the values of {sup 238}U specific concentrations ranged from 16.0 to 647.7 Bq.Kg{sup -1} and {sup 40}K specific concentrations ranged from 19.1 to 12713 Bq.Kg{sup -1} . Concentrations of values are consistent with those found in literature. (author)

  18. Efeito da casca da berinjela (Solanum melongena) sobre as concentrações plasmáticas de triglicerídeos, colesterol total e frações lipídicas, em cobaias (Cavia porcellus) hiperlipidêmicos ( The effect of the eggplant core on blood lipid concentrations in hypercholesterolemic guinea pigs (Cavia porcellus) )

    NARCIS (Netherlands)

    Cherem, A.D.R.; Tramonte, V.L.C.G.; Fett, R.; Dokkum, W. van

    2007-01-01

    We investigated the effect of the eggplant core on the plasma concentrations of triglycerides, total- LDL- and HDL-cholesterol, in male guinea pigs, randomly assigned into five groups: 1 (N) - normolipidic diet AIN-93G, 2 (NB) - normolipidic diet, supplemented with eggplant core, halfway of the expe

  19. Efeito da casca da berinjela (Solanum melongena) sobre as concentrações plasmáticas de triglicerídeos, colesterol total e frações lipídicas, em cobaias (Cavia porcellus) hiperlipidêmicos ( The effect of the eggplant core on blood lipid concentrations in hypercholesterolemic guinea pigs (Cavia porcellus) )

    NARCIS (Netherlands)

    Cherem, A.D.R.; Tramonte, V.L.C.G.; Fett, R.; Dokkum, W. van

    2007-01-01

    We investigated the effect of the eggplant core on the plasma concentrations of triglycerides, total- LDL- and HDL-cholesterol, in male guinea pigs, randomly assigned into five groups: 1 (N) - normolipidic diet AIN-93G, 2 (NB) - normolipidic diet, supplemented with eggplant core, halfway of the

  20. Differential effect of extracellular calcium on the Na(+)-K+ pump activity in intact polymorphonuclear leucocytes and erythrocytes

    DEFF Research Database (Denmark)

    Petersen, R H; Knudsen, T; Johansen, Torben

    1991-01-01

    The effect of extracellular calcium on the Na(+)-K+ pump activity in human polymorphonuclear leucocytes and erythrocytes was studied and compared with the activity in mixed peritoneal leucocytes from rats. While there was maximal decrease in the pump activity (25-30%) of leucocytes from both rat...... and human by calcium 0.6 mM, a concentration of 0.1 mM caused a substantial decrease indicating a high sensitivity for extracellular calcium. In contrast, calcium had no effect on the pump activity in erythrocytes. The effect of calcium on the pump activity in leucocytes may be due to regulation...

  1. Presence of a lethal protease in the extracellular products of Vibrio splendidus-Vibrio lentus related strains.

    Science.gov (United States)

    Farto, R; Armada, S P; Montes, M; Perez, M J; Nieto, T P

    2006-12-01

    The presence of a lethal extracellular 39-kDa protease, a virulence determinant of a Listonella pelagia strain which produces vibriosis in turbot, was determined in the extracellular products (ECP) of 33 Vibrionaceae strains. Both immunological and enzymatic techniques distinguished this specific protease from other Vibrionaceae proteins. It was detected in 15% (5/33) of the ECPs assayed belonging to strains of the Vibrio splendidus-V. lentus related group isolated in Galician aquaculture systems (NW Spain). As these strains were associated with diseased octopus and cultured turbot, were able to colonize the internal organs of fish and produced a lethal ECP for fish, they are a potential risk for the health of reared aquatic organisms.

  2. Extracellular Enzyme Activity assay as indicator of soil microbial functional diversity and activity

    DEFF Research Database (Denmark)

    Hendriksen, Niels Bohse; Winding, Anne

    2012-01-01

    Extracellular Enzyme Activity assay as indicator of soil microbial functional diversity and activity Niels Bohse Hendriksen, Anne Winding. Department of Environmental Science, Aarhus University, 4000 Roskilde, Denmark Soil enzymes originate from a variety of organisms, notably fungi and bacteria...... and especially hydrolytic extracellular enzymes are of pivotal importance for decomposition of organic substrates and biogeochemical cycling. Their activity reflects the functional diversity and activity of the microorganisms involved in decomposition processes which are essential processes for soil functioning......, experimental conditions of extraction of enzymes from soils, buffer and pH, substrate concentration, temperature and the necessary controls were optimized and standardized. This has resulted in an optimized standard operating procedure of EEA, which are being tested as an indicator of soil functional diversity...

  3. The voltage dependence of GABAA receptor gating depends on extracellular pH.

    Science.gov (United States)

    Pytel, Maria; Mercik, Katarzyna; Mozrzymas, Jerzy W

    2005-11-28

    Recent studies have indicated that changes in extracellular pH and in membrane voltage affect the gamma-amino-n-butyric acid type A receptor gating mainly by altering desensitization and binding. To test whether the effects of membrane potential and pH are additive, their combined actions were investigated. By analyzing the current responses to rapid gamma-amino-n-butyric acid applications, we found that the current to voltage relationship was close to linear at acid pH but the increasing pH induced an inward rectification. Desensitization was enhanced at depolarizing potentials, but this strongly depended on pH, being weak at acidic and strong at basic pH values. A similar trend was observed for the onset rate of responses to saturating gamma-amino-n-butyric acid concentration. These data provide evidence that the voltage sensitivity of GABAA receptors depends on extracellular pH.

  4. The voltage dependence of GABAA receptor gating depends on extracellular pH

    Science.gov (United States)

    Pytel, Maria; Mercik, Katarzyna; Mozrzymas, Jerzy W.

    2007-01-01

    Recent studies have indicated that changes in extracellular pH and in membrane voltage affect the γ-amino-n-butyric acid type A receptor gating mainly by altering desensitization and binding. To test whether the effects of membrane potential and pH are additive, their combined actions were investigated. By analyzing the current responses to rapid γ-amino-n-butyric acid applications, we found that the current to voltage relationship was close to linear at acid pH but the increasing pH induced an inward rectification. Desensitization was enhanced at depolarizing potentials, but this strongly depended on pH, being weak at acidic and strong at basic pH values. A similar trend was observed for the onset rate of responses to saturating γ-amino-n-butyric acid concentration. These data provide evidence that the voltage sensitivity of GABAA receptors depends on extracellular pH. PMID:16272885

  5. A bioelectrochemical approach to characterize extracellular electron transfer by Synechocystis sp. PCC6803.

    Directory of Open Access Journals (Sweden)

    Angelo Cereda

    Full Text Available Biophotovoltaic devices employ photosynthetic organisms at the anode of a microbial fuel cell to generate electrical power. Although a range of cyanobacteria and algae have been shown to generate photocurrent in devices of a multitude of architectures, mechanistic understanding of extracellular electron transfer by phototrophs remains minimal. Here we describe a mediatorless bioelectrochemical device to measure the electrogenic output of a planktonically grown cyanobacterium, Synechocystis sp. PCC6803. Light dependent production of current is measured, and its magnitude is shown to scale with microbial cell concentration and light intensity. Bioelectrochemical characterization of a Synechocystis mutant lacking Photosystem II demonstrates conclusively that production of the majority of photocurrent requires a functional water splitting aparatus and electrons are likely ultimately derived from water. This shows the potential of the device to rapidly and quantitatively characterize photocurrent production by genetically modified strains, an approach that can be used in future studies to delineate the mechanisms of cyanobacterial extracellular electron transport.

  6. Determination of the air attenuation and electronic loss for the free air concentric cylinders ionization chamber; Determinacao da atenuacao do ar e perda eletronica para a camara de ionizacao de ar livre de cilindros concentricos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Hebert Pinto Silveira de

    2010-07-01

    Along the latest years, the LNMRI has been proceeding a continuous research work with a concentric cylinders type free air ionizing chamber (VICTOREEN, model 481), aiming to establish it as a new national standard, and, as a consequence, replace the worldwide accepted secondary standard, calibrated by PTB. Taking into account that the absolute determination of kerma in air with a free air ionizing chamber implies the acquirement of a number of correction factors. The main objective of the present work comprises the determination of the two factors, specifically, electronic loss (k{sub e}) and air attenuation (k{sub a}). The correction factors were obtained through mammography qualities reference spectrum, using Monte Carlo simulation method. The Penelope code was used in the simulation procedures. Simulations took place in two stages, the acquirement of specters related to the qualities of interest (mammography) with the x ray tube (Pantak, model HF160 e Panalytical, model XRF window), and the free-air ionization chamber. The data were compared to those related to the BIPM chamber, to electronic loss were not detected. The comparison between air attenuation factors was obtained data bellow 0.13%. (author)

  7. Composição química e perfil de ácidos graxos da carne de bovinos de diferentes condições sexuais recebendo silagem de milho e concentrado ou cana-de-açúcar e concentrado contendo grãos de girassol Chemical traits and fatty acids composition of beef from young bulls, steers and heifers fed corn silage and concentrate or sugarcane and concentrate with sunflower grains

    Directory of Open Access Journals (Sweden)

    Alexandre Rodrigo Mendes Fernandes

    2009-04-01

    Full Text Available O objetivo neste trabalho foi avaliar as características químicas e a composição em ácidos graxos do contrafilé (músculo Longissimus de tourinhos, novilhos e novilhas da raça Canchim. Os animais foram terminados em confinamento com duas dietas experimentais, uma com silagem de milho e concentrado e outra com cana-de-açúcar e concentrado contendo grãos de girassol. Os teores de umidade, proteína e minerais no músculo não diferiram entre as dietas e as condições sexuais dos animais. A carne de novilhos terminados com a dieta com grãos de girassol apresentou maior teor de lipídios (3,31% em comparação à dos animais de outras categorias. Os animais que receberam a dieta com grãos de girassol apresentaram maiores concentrações de ácido linoléico conjugado (18:2 cis9, trans-11 (0,73% e ácidos graxos poliinsaturados (8,12% no músculo, e também relações mais elevadas de ácidos graxos insaturados:saturados (0,93 e ácidos graxos poliinsaturados:saturados (0,16 em comparação àqueles que receberam a dieta convencional, à base de silagem de milho (0,34%; 6,31%; 0,86; e 0,11, respectivamente. A composição em ácidos graxos da carne de bovinos pode ser melhorada com a utilização de cana-de-açúcar e grãos de girassol na dieta dos animais terminados em confinamento.The objective in this work was to evaluate the chemical characteristics and the fatty acids composition of beef loin (Longissimus muscle of young bulls, steers and heifers of Canchim breed. The animals were finished in feedlot system and fed two experimental diets, one with corn silage and concentrate (SIL and the other with sugar cane, as exclusive roughage, and concentrate containing sunflower grains (CNA. Differences were not detected in relation to moisture, protein and mineral contents between diets or sexual categories. The meat from steers that received the CNA diet had higher lipid content (3.31% in relation to meat from young bulls and heifers

  8. Extracellular polymeric substances of bacteria and their potential environmental applications.

    Science.gov (United States)

    More, T T; Yadav, J S S; Yan, S; Tyagi, R D; Surampalli, R Y

    2014-11-01

    Biopolymers are considered a potential alternative to conventional chemical polymers because of their ease of biodegradability, high efficiency, non-toxicity and non-secondary pollution. Recently, extracellular polymeric substances (EPS, biopolymers produced by the microorganisms) have been recognised by many researchers as a potential flocculent for their applications in various water, wastewater and sludge treatment processes. In this context, literature information on EPS is widely dispersed and is very scarce. Thus, this review marginalizes various studies conducted so far about EPS nature-production-recovery, properties, environmental applications and moreover, critically examines future research needs and advanced application prospective of the EPS. One of the most important aspect of chemical composition and structural details of different moieties of EPS in terms of carbohydrates, proteins, extracellular DNA, lipid and surfactants and humic substances are described. These chemical characteristics of EPS in relation to formation and properties of microbial aggregates as well as degradation of EPS in the matrix (biomass, flocs etc) are analyzed. The important engineering properties (based on structural characteristics) such as adsorption, biodegradability, hydrophilicity/hydrophobicity of EPS matrix are also discussed in details. Different aspects of EPS production process such as bacterial strain maintenance; inoculum and factors affecting EPS production were presented. The important factors affecting EPS production include growth phase, carbon and nitrogen sources and their ratio, role of other nutrients (phosphorus, micronutrients/trace elements, and vitamins), impact of pH, temperature, metals, aerobic versus anaerobic conditions and pure and mixed culture. The production of EPS in high concentration with high productivity is essential due to economic reasons. Therefore, the knowledge about all the aspects of EPS production (listed above) is highly

  9. Calor específico e densidade da polpa de cajá (Spondias lutea L. com diferentes concentrações de sólidos solúveis sob baixas temperaturas Cajá pulp (Spondias lutea L. specific heat and density for different soluble solids concentrations at low temperatures

    Directory of Open Access Journals (Sweden)

    Mario E. R. M. Cavalcanti Mata

    2005-08-01

    Full Text Available A polpa de cajá tem sido exportada da região Nordeste para todo o Brasil, e uma das maneiras de conservá-la é processando-a e armazenado-a na forma congelada. Durante o processamento, existem dois fatores que favorecem a qualidade do produto a ser armazenado: a rapidez com que o produto é congelado e a adição de açúcar como forma de dificultar a ação microbiológica. Na linha de processo, algumas propriedades termofísicas, como o calor específico e a densidade, se alteram com as temperaturas negativas e com o teor de sólidos solúveis totais; dessa forma, para o dimensionamento adequado de máquinas e equipamentos, torna-se necessário conhecer essas propriedades, principalmente quando se operam equipamentos criogênicos, onde as temperaturas podem chegar a -196 ºC. Neste trabalho, determinaram-se a densidade e o calor específico da polpa do cajá com quatro diferentes níveis de sólidos solúveis totais (natural da polpa; 20; 40 e 60% e temperaturas entre -196 ºC e -18 ºC. A densidade foi obtida pela razão entre a massa da polpa e o seu volume. O volume foi determinado pelo método do deslocamento de massa (água e o calor específico por meio de balanço de calor entre a massa da polpa, a massa do cilindro que contém a polpa e a massa do gelo. Conclui-se que a densidade da polpa de cajá aumenta em função da redução da temperatura e do aumento do teor de sólidos solúveis totais de 9 para 60 °Brix e que o calor específico da polpa diminui com a diminuição de temperatura e aumenta com a concentração de sólidos solúveis totais.The cajá pulp has been exported from the Northeast area to all parts of Brazil, and one of the ways of conserving it is processing and storing it in the frozen form. During the processing, there are two factors that favor the quality of the product to be stored; the speed that the product is frozen and the addition of sugar as a form of hindering the microbiologic action. In the process

  10. Perturbation of red blood cell membrane rigidity by extracellular ligands.

    Science.gov (United States)

    Paulitschke, M; Nash, G B; Anstee, D J; Tanner, M J; Gratzer, W B

    1995-07-01

    It is known that binding of extracellular antibodies against the major sialoglycoprotein, glycophorin A, reduced the deformability of the red blood cell membrane. This has been taken to result from new or altered interactions between the glycophorin A and the membrane skeleton. We have shown by means of the micropipette aspiration technique that antibodies against the preponderant transmembrane protein, band 3, induce similar effects. A definite but much smaller reduction in elasticity of the membrane is engendered by univalent Fab fragments of the anti-band 3 antibodies. By examining cells genetically devoid of glycophorin A or containing a variant of this constituent, truncated at the inner membrane surface, we have shown that the anti-band 3 antibodies do not act through the band 3-associated glycophorin A. We examined the effect of anti-glycophorin A antibodies on homozygous Wr(a+b-) cells, in which an amino acid replacement in band 3 annihilates the Wright b (Wrb) epitope (comprising sequence elements of glycophorin A and band 3) and thus, by implication disrupts or perturbs the band 3-glycophorin A interaction; these cells show a much smaller response to an anti-glycophorin A antibody than do normal controls. We infer that in this case anti-glycophorin A antibodies exert their rigidifying effect through the associated band 3. Another anti-glycophorin A antibody, directed against an epitope remote from the membrane surface, however, increases the rigidity of both Wr(a+b-) and normal cells. This implies that not all antibodies act in the same manner in modifying the membrane mechanical properties. The effect exerted by anti-band 3 antibodies appears not to be transmitted through the band 3-ankyrin-spectrin pathway because the rigidifying effect of the intact antibody persists at alkaline pH, at which there is evidence that the ankyrin-band 3 link is largely dissociated. The large difference between the effects of saturating concentrations of the divalent and

  11. Increased Cortical Extracellular Adenosine Correlates with Seizure Termination

    Science.gov (United States)

    Van Gompel, Jamie J.; Bower, Mark R.; Worrell, Gregory A.; Stead, Matt; Chang, Su-Youne; Goerss, Stephan J.; Kim, Inyong; Bennet, Kevin E.; Meyer, Fredric B.; Marsh, W. Richard; Blaha, Charles D.; Lee, Kendall H.

    2014-01-01

    Objective Seizures are currently defined by their electrographic features. However, neuronal networks are intrinsically dependent upon neurotransmitters of which little is known regarding their peri-ictal dynamics. Evidence supports adenosine as having a prominent role in seizure termination, as its administration can terminate and reduce seizures in animal models. Further, microdialysis studies in humans suggest adenosine is elevated peri-ictally, but the relationship to the seizure is obscured by its temporal measurement limitations. Because electrochemical techniques can provide vastly superior temporal resolution, we test the hypothesis that extracellular adenosine concentrations rise during seizure termination in an animal model and humans using electrochemistry. Methods White farm swine (n=45) were used in an acute cortical model of epilepsy and 10 human epilepsy patients were studied during intraoperative electrocorticography (Ecog). Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS) based fast scan cyclic voltametry (FSCV) and fixed potential amperometry were obtained utilizing an adenosine specific triangular waveform or biosensors respectively. Results Simultaneous Ecog and electrochemistry demonstrated an average adenosine rise of 260% compared to baseline at 7.5 ± 16.9 seconds with amperometry (n=75 events) and 2.6 ± 11.2 seconds with FSCV (n=15 events) prior to electrographic seizure termination. In agreement with these animal data, adenosine elevation prior to seizure termination in a human patient utilizing FSCV was also seen. Significance Simultaneous Ecog and electrochemical recording supports the hypothesis that adenosine rises prior to seizure termination, suggesting that adenosine itself may be responsible for seizure termination. Future work using intraoperative WINCS based FSCV recording may help to elucidate the precise relationship between adenosine and seizure termination. PMID:24483230

  12. Extracellular production of tellurium nanoparticles by the photosynthetic bacterium Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Brucale, Marco [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Fortunato, Gianuario [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Lanzi, Massimiliano [Dept. of Industrial Chemistry “Toso Montanari”, University of Bologna (Italy); Mezzi, Alessio [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Valle, Francesco; Cavallini, Massimiliano [Institute for the Study of Nanostructured Materials (CNR-ISMN), Bologna (Italy); Zannoni, Davide [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy)

    2016-05-15

    Highlights: • Tellurite is reduced by R. capsulatus as cytosolic tellurium nanoprecipitates TeNPs. • Lawsone allows R. capsulatus to produce extracellular TeNPs. • Extracellular TeNPs production depends on the carbon source used for cells growth. • Both lawsone concentration and the incubation time determine the TeNPs size. • Extracellular TeNPs are coated with extracellular polymeric substances (EPS). - Abstract: The toxic oxyanion tellurite (TeO{sub 3}{sup 2−}) is acquired by cells of Rhodobacter capsulatus grown anaerobically in the light, via acetate permease ActP2 and then reduced to Te{sup 0} in the cytoplasm as needle-like black precipitates. Interestingly, photosynthetic cultures of R. capsulatus can also generate Te{sup 0} nanoprecipitates (TeNPs) outside the cells upon addition of the redox mediator lawsone (2-hydroxy-1,4-naphtoquinone). TeNPs generation kinetics were monitored to define the optimal conditions to produce TeNPs as a function of various carbon sources and lawsone concentration. We report that growing cultures over a 10 days period with daily additions of 1 mM tellurite led to the accumulation in the growth medium of TeNPs with dimensions from 200 up to 600–700 nm in length as determined by atomic force microscopy (AFM). This result suggests that nucleation of TeNPs takes place over the entire cell growth period although the addition of new tellurium Te{sup 0} to pre-formed TeNPs is the main strategy used by R. capsulatus to generate TeNPs outside the cells. Finally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analysis of TeNPs indicate they are coated with an organic material which keeps the particles in solution in aqueous solvents.

  13. Diffusion characteristics and extracellular volume fraction during normoxia and hypoxia in slices of rat neostriatum.

    Science.gov (United States)

    Rice, M E; Nicholson, C

    1991-02-01

    1. Diffusion properties of submerged, superfused slices from the rat neostriatum were measured by quantitative analysis of concentration-time profiles of tetramethylammonium (TMA+) introduced by iontophoresis. TMA+ was sensed at an ion-selective microelectrode (ISM) positioned 100-150 microns from the source pipette. Slice viability was assessed from the extracellular field potentials evoked by intrastriatal electrical stimulation. 2. Under normoxic conditions the extracellular volume fraction (alpha) was 0.21 (range 0.18-0.24), and the tortuosity (lambda) was 1.54, in slices with good field potentials. In slices with poor field potentials, alpha was 0.09-0.16. Extraction of correct alpha and lambda in the slice required evaluation of nonspecific uptake, k', which was 1 x 10(-2) s-1. 3. Slices were made hypoxic by superfusing physiological saline equilibrated with 95% N2-5% CO2 for 10-30 min. Synaptic components of field potentials were inhibited after 3-4 min in hypoxic media. In some experiments extracellular K+ concentration [( K+]o) was monitored with ISMs. During hypoxia, [K+]o rose from an average baseline of 5.1 mM to 7-10 mM. After reoxygenation, [K+]o transiently fell below the original level. 4. The average value for alpha during hypoxia was 0.13 (a 38% decrease), which was significantly different from control (P less than 0.001) and increased progressively during hypoxic exposure. In contrast, tortuosity and k' were unchanged by this treatment. 5. These data represent the first characterization of the diffusion properties of the rat striatal slice and of changes in extracellular volume fraction during hypoxia in a brain slice preparation.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Electrical slow waves in the mouse oviduct are dependent on extracellular and intracellular calcium sources

    Science.gov (United States)

    Dixon, Rose Ellen; Britton, Fiona C.; Baker, Salah A.; Hennig, Grant W.; Rollings, Christina M.; Sanders, Kenton M.

    2011-01-01

    Spontaneous contractions of the myosalpinx are critical for oocyte transport along the oviduct. Slow waves, the electrical events that underlie myosalpinx contractions, are generated by a specialized network of pacemaker cells called oviduct interstitial cells of Cajal (ICC-OVI). The ionic basis of oviduct pacemaker activity is unknown. Intracellular recordings and Ca2+ imaging were performed to examine the role of extracellular and intracellular Ca2+ sources in slow wave generation. RT-PCR was performed to determine the transcriptional expression of Ca2+ channels. Molecular studies revealed most isoforms of L- and T-type calcium channels (Cav1.2,1.3,1.4,3.1,3.2,3.3) were expressed in myosalpinx. Reduction of extracellular Ca2+ concentration ([Ca2+]o) resulted in the abolition of slow waves and myosalpinx contractions without significantly affecting resting membrane potential (RMP). Spontaneous Ca2+ waves spread through ICC-OVI cells at a similar frequency to slow waves and were inhibited by reduced [Ca2+]o. Nifedipine depolarized RMP and inhibited slow waves; however, pacemaker activity returned when the membrane was repolarized with reduced extracellular K+ concentration ([K+]o). Ni2+ also depolarized RMP but failed to block slow waves. The importance of ryanodine and inositol 1,4,5 trisphosphate-sensitive stores were examined using ryanodine, tetracaine, caffeine, and 2-aminoethyl diphenylborinate. Results suggest that although both stores are involved in regulation of slow wave frequency, neither are exclusively essential. The sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitor cyclopiazonic acid inhibited pacemaker activity and Ca2+ waves suggesting that a functional SERCA pump is necessary for pacemaker activity. In conclusion, results from this study suggest that slow wave generation in the oviduct is voltage dependent, occurs in a membrane potential window, and is dependent on extracellular calcium and functional SERCA pumps. PMID:21881003

  15. Reprint of “Extracellular production of tellurium nanoparticles by the photosynthetic bacterium Rhodobacter capsulatus”

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Brucale, Marco [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Fortunato, Gianuario [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Lanzi, Massimiliano [Dept. of Industrial Chemistry “Toso Montanari”, University of Bologna (Italy); Mezzi, Alessio [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Valle, Francesco; Cavallini, Massimiliano [Institute for the Study of Nanostructured Materials (CNR-ISMN), Bologna (Italy); Zannoni, Davide [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy)

    2017-02-15

    Highlights: • Tellurite is reduced by R. capsulatus as cytosolic tellurium nanoprecipitates TeNPs. • Lawsone allows R. capsulatus to produce extracellular TeNPs. • Extracellular TeNPs production depends on the carbon source used for cells growth. • Both lawsone concentration and the incubation time determine the TeNPs size. • Extracellular TeNPs are coated with extracellular polymeric substances (EPS). - Abstract: The toxic oxyanion tellurite (TeO{sub 3}{sup 2−}) is acquired by cells of Rhodobacter capsulatus grown anaerobically in the light, via acetate permease ActP2 and then reduced to Te{sup 0} in the cytoplasm as needle-like black precipitates. Interestingly, photosynthetic cultures of R. capsulatus can also generate Te{sup 0} nanoprecipitates (TeNPs) outside the cells upon addition of the redox mediator lawsone (2-hydroxy-1,4-naphtoquinone). TeNPs generation kinetics were monitored to define the optimal conditions to produce TeNPs as a function of various carbon sources and lawsone concentration. We report that growing cultures over a 10 days period with daily additions of 1 mM tellurite led to the accumulation in the growth medium of TeNPs with dimensions from 200 up to 600–700 nm in length as determined by atomic force microscopy (AFM). This result suggests that nucleation of TeNPs takes place over the entire cell growth period although the addition of new tellurium Te{sup 0} to pre-formed TeNPs is the main strategy used by R. capsulatus to generate TeNPs outside the cells. Finally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analysis of TeNPs indicate they are coated with an organic material which keeps the particles in solution in aqueous solvents.

  16. Estudo comparativo da concentração salivar do fator de crescimento epidérmico em indivíduos com laringite crônica por doença do refluxo gastroesofágica antes e após o tratamento: resultados preliminares Salivary egf concentration in adults with reflux chronic laryngitis before and after treatment: preliminary results

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    Claudia Alessandra Eckley

    2007-04-01

    Full Text Available Os mecanismos fisiopatológicos do refluxo laringofaríngeo (RLF são pouco conhecidos. O Fator de Crescimento Epidérmico (EGF é a proteína de produção salivar com maior ação na regeneração do epitélio da orofaringe e tubo digestivo alto, tendo sido demonstradas deficiências em sua concentração salivar em indivíduos com RLF. OBJETIVO: Comparar a concentração salivar de EGF em um mesmo indivíduo com RLF antes e após o tratamento. MATERIAL E MÉTODO: Neste estudo prospectivo doze indivíduos com DRGE e RLF de moderada intensidade tiveram sua saliva espontânea coletada antes e após o tratamento e controle da doença. A concentração salivar de EGF foi estabelecida através de exame de ELISA (Quantikine ®. RESULTADOS: Onze pacientes eram do sexo feminino e um do sexo masculino, com idade média de 49 anos. A concentração salivar de EGF pré-tratamento foi de 2.867,6pg/mL e a pós-tratamento foi 1.588,5pg/mL, sendo esta diferença estatisticamente significante (p=0,015. DISCUSSÃO E CONCLUSÕES: Apesar de a concentração salivar de EGF ser maior nos indivíduos antes do tratamento, esta não consegue alcançar àquela de uma população normal (estabelecida previamente, o que sugere uma deficiência primária deste importante fator de defesa em indivíduos com RLF.The Laryngopharyngeal Reflux (LPR physiopathology is still unknown. The Epidermal Growth Factor (EGF is a biologically active salivary protein that aids in the rapid regeneration of the oropharyngeal and upper digestive tract mucosas. Salivary deficiency of this protein in patients with LPR has been demonstrated in previous studies. AIM: To compare salivary EGF concentration in patients with LPR before and after treatment. MATERIALS AND METHODS: In this prospective study twelve patients with GERD and moderate LPR were studied. Whole saliva samples were collected before and after treatment and salivary EGF concentration was determined using a commercially available

  17. Efeitos do exercício crônico sobre a concentração circulante da leptina e grelina em ratos com obesidade induzida por dieta Effects of the chronic exercise on the circulating concentration of leptin and ghrelin in rats With diet-induced obesity

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    Ricardo Eguchi

    2008-06-01

    Full Text Available A obesidade vem se tornando uma das maiores epidemias mundiais, dessa forma, conhecer sua etiologia e mecanismos que regulam seu desenvolvimento é de grande relevância para o seu Tratamento. Portanto, o objetivo do presente estudo foi avaliar os efeitos da obesidade exógena induzida pela dieta de cafeteria e da atividade física crônica em ratos, sobre a adiposidade e a concentração sérica dos hormônios reguladores do balanço energético (leptina e grelina. Foram utilizados 32 ratos Wistar machos, divididos em quatro grupos: Sedentário alimentado com dieta padrão (SN, sedentário alimentado com dieta de cafeteria (SC, treinado alimentado com dieta padrão (TN e treinado alimentado com dieta de cafeteria (TC. A dieta de cafeteria aumentou significativamente a adiposidade central (RET e visceral (EPI (pObesity is becoming one of the biggest worldwide epidemics. Therefore, knowing its etiology and mechanisms that regulate its development is of great relevance for its treatment. Thus, the aim of the present study was to evaluate the effects of obesity induced by the palatable hyperlipidic diet and of the chronic physical activity in rats, on the adiposity and the serum concentration of regulating hormones of the energy balance (leptin and ghrelin. 32 male Wistar rats were divided in four groups: Sedentary fed with chow diet (SN, sedentary fed with cafeteria diet (SC, trained fed with chow diet (TN and trained fed with cafeteria diet (TC. The cafeteria diet led to a significant increase of central (RET and visceral (EPI adiposity (p<0.05. Conversely,the exercise training minimized the effect of the cafeteria diet, diminishing the central and visceral adiposity. Leptin was also increased in the groups fed with the cafeteria diet, suggesting increase of the resistance to the action of this hormone. Chronic physical activity did not hinder the development of hyperleptinemia. Reduction in the serum ghrelin concentration was observed only in

  18. Comparison of the fluorescent polarization (TDx and the enzymatic competitive (EMIT 2000 immune assays for the measurement of cyclosporin A blood concentration Comparação dos imuno-ensaios de fluorescência polarizada (TDx e enzimático competitivo (EMIT 2000 na dosagem da concentração de ciclosporina A no sangue total

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    Elias David-Neto

    2000-12-01

    Full Text Available Evaluation of Cyclosporin A (CyA blood concentration is imperative in solid organ transplantation in order to achieve maximal immunosuppression with the least side effects. We compared the results of whole blood concentrations of CyA in 50 blood samples simultaneously evaluated by the fluorescent polarization immune assay (TDx and the enzymatic competitive immune assay (EMIT 2000. There was a strong correlation between both kits for any range of CyA blood concentration (R=0.99, pA avaliação da concentração sanguínea de ciclosporina A (CyA é necessária em transplantes de órgãos sólidos para obter-se máxima imunosupressão e mínimos efeitos colaterais. Nós comparamos os resultados da concentração de CyA em 50 amostras sanguíneas analisadas pelos métodos dos imuno-ensaios de fluorescência polarizada (TDx e enzimático competitivo (EMIT 2000. Houve uma forte correlação entre ambos métodos para qualquer faixa de concentração de CyA (R=0.99, p<0.001. Os coeficientes de variação intra e interensaio foram menores que 4% para ambos os métodos. O custo para cada análise de CyA foi 50% menor para o EMIT em comparação com o TDx. Concluímos que a metodologia EMIT é tão acurada quanto a de TDx para dosar CyA em amostras sanguíneas. Além disso, a metodologia EMIT é mais prática para ser realizada e mais barata, sendo ainda possível adotá-la para dosagens de CyA em vários horários de um mesmo dia.

  19. Avaliação da concentração de pectinase no processo de hidrólise-sacarificação do farelo de mandioca para obtenção de etanol Determination of the pectinase concentration in hydrolysis - saccharification process for ethanol production by cassava fibrous residue

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    M. LEONEL

    2000-08-01

    Full Text Available Neste trabalho objetivou-se avaliar a concentração de pectinase (Pectinex Ultra SP-L no processo de hidrólise-sacarificação do farelo de mandioca para produção de etanol. Foram avaliadas quatro concentrações da enzima pectinase com enzima complemetar as amilases e o tratamento com apenas as amilases. Realizou-se a caracterização do hidrolisado e resíduo fibroso resultantes do processo, e os resultados obtidos demonstraram que a concentração mínima de pectinase para um bom rendimento do processo foi 8Kg enzima/t fibras, com. 89,4% do amido hidrolisado. Quanto ao resíduo fibroso, este apresenta potencialidade de aproveitamento com base para produtos dietéticos ricos em fibras.This work was proposed to determine of the pectinase concentration in process of the ethanol production by cassava fibrous waste. The results indicated that minimal concentration of pectinase was 8Kg/t fibre and 89.4% starch was hydrolyzed in process. The treatment without pectinase 72.5% of starch was hydrolyzed. The final residues may be used as high-fiber food product.

  20. Microbial modeling of thermal resistance of Alicyclobacillus acidoterrestris CRA7152 spores in concentrated orange juice with nisin addition Modelagem microbiana da resistência térmica de esporos de Alicyclobacillus acidoterrestris CRA7152 em suco de laranja concentrado com adição de nisina

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    Wilmer Edgard Luera Peña

    2009-09-01

    Full Text Available The nisin effect on thermal death of Alicyclobacillus acidoterrestris CRA 7152 spores in concentrated orange juice (64ºBrix was studied. Concentrations of 0, 50, 75 and 100 IU of nisin/ml juice, at temperatures of 92, 95, 98 and 102ºC were evaluated. The quadratic polynomial model was used to analyze the effects of the factors and their interaction. Verification of surviving spores was carried out through plating in K medium (pH 3.7. The results showed that the D values without nisin addition were 25.5, 12.9, 6.1 and 2.3 min for 92, 95, 98 and 102ºC respectively. With addition of nisin into the juice there was a drop of heat resistance as the concentration was increased at a same temperature. With 30, 50, 75, 100 and 150 IU/ml at 95ºC, the D values were 12.34, 11.38, 10.49, 9.49 and 9.42 min respectively, showing that a decrease in the D value up to 27% can be obtained. The second order polynomial model established with r² = 0.995 showed that the microorganism resistance was affected by the action of temperature followed by the nisin concentration. Nisin therefore is an alternative for reducing the rigor of the A. acidoterrestris CRA 7152 thermal treatment.Estudou-se o efeito da nisina na inativação térmica dos esporos de Alicyclobacillus acidoterrestris CRA 7152 em suco de laranja concentrado (64 ºBrix. Foram avaliadas as concentrações de 0, 50, 75 e 100 UI de nisina/ml de suco nas temperaturas de 92, 95, 98 e 102 ºC. Foi utilizado o modelo polinomial quadrático para analisar os efeitos dos fatores e suas interações. A contagem dos esporos sobreviventes foi feita atravé