926 resultados para Gellan-gum hydrogels and spongy-like


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A myographic study was performed to compare the neuromuscular effects of venoms and crotoxin-like proteins from Crotalus durissus ruruima and Crotalus durissus cumanensis in mice phrenic-diaphragm preparation. It was concluded that both venoms present neurotoxic activity as a consequence of their crotoxin content. Furthermore, crotoxin from C.d. cumanensis is more potent than that from C.d. ruruima venom. At the concentration range in which both venoms express neurotoxic activity, only C.d. cumanensis venom also manifest a direct myotoxic effect that probably involves the synergic participation of other components than crotoxin. (C) 2015 Elsevier Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Twenty six Murrah female river buffaloes, between 45 and 70 d post-partum, empty, multiparae, with an average live weight of 675 ± 56 kg, and average body condition of 3.5 points, in a 1 to 5 scale, were used to determine the concentrations of glucose, cholesterol, total protein and insulin-like growth factor type I(IGF-I) in the follicular fluid. The fluid was collected from dominant follicles, with diameters between 8 and 12 mm, by in vivo follicular aspiration. The oestrous cycle stage was not taken into account. The wave of follicular development was synchronized six days prior to the collection. Biochemical analyses of glucose and cholesterol were performed by the enzymatic colorimetric method with the utilization of commercial kits of Glicose (GOD-PAP) and Cholesterol (CHOD-PAP) (Kovalent), respectively. For the determination of total protein, the commercial kit total Protein (Kovalent), method Biuret, was employed. Readings were carried out through absorption spectrophotometry with visible light. Through the radioimmunoanalysis (RIA) technique the concentration of IGF-I was obtained using commercial kits of IRMA IGF-I (IMMUNOTECH). Descriptive statistics was used, by applying the PROC MEANS procedure of the SAS (2009) statistical package. Glucose concentrations (4.0 ± 0.75 mmol/L) and IGF-I (340 ± 129.83 ng/mL) showed higher values in female river buffaloes and dairy cows regarding those reported in other studies. However, cholesterol levels (0.51 ± 0.12 mmol/L) and total proteins (58.4 ± 4.43 g/L) were lower. Results indicate that there is a relationship between the concentration of biochemical indicators, the nutritional aspects, the diameter of the aspired follicles and the productive period.

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The aim of the present study was to evaluate the behavioral patterns associated with autism and the prevalence of these behaviors in males and females, to verify whether our model of lipopolysaccharide (LPS) administration represents an experimental model of autism. For this, we prenatally exposed Wistar rats to LPS (100 mu g/kg, intraperitoneally, on gestational day 9.5), which mimics infection by gram-negative bacteria. Furthermore, because the exact mechanisms by which autism develops are still unknown, we investigated the neurological mechanisms that might underlie the behavioral alterations that were observed. Because we previously had demonstrated that prenatal LPS decreases striatal dopamine (DA) and metabolite levels, the striatal dopaminergic system (tyrosine hydroxylase [TH] and DA receptors D1a and D2) and glial cells (astrocytes and microglia) were analyzed by using immunohistochemistry, immunoblotting, and real-time PCR. Our results show that prenatal LPS exposure impaired communication (ultrasonic vocalizations) in male pups and learning and memory (T-maze spontaneous alternation) in male adults, as well as inducing repetitive/restricted behavior, but did not change social interactions in either infancy (play behavior) or adulthood in females. Moreover, although the expression of DA receptors was unchanged, the experimental animals exhibited reduced striatal TH levels, indicating that reduced DA synthesis impaired the striatal dopaminergic system. The expression of glial cell markers was not increased, which suggests that prenatal LPS did not induce permanent neuroinflammation in the striatum. Together with our previous finding of social impairments in males, the present findings demonstrate that prenatal LPS induced autism-like effects and also a hypoactivation of the dopaminergic system. (c) 2012 Wiley Periodicals, Inc.

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The objective of this study was to evaluate lyophilized bovine colostrum as an alternative source of passive immunity and insulin like growth factor I (IGF-I) for goat kids, considering newborns consuming non-maternal colostrum. Twenty-nine male newborns received 5% of body weight of lyophilized bovine (LBC) or goat colostrum (GC), both with 55 mg/mL of IgG, at 0, 7 and 14 h of life. Blood samples were collected at 0, 7, 14, 18, 24, 36, 48, 72 and 96 h of life to determine serum IgG, total protein (TP), IGF-I and apparent efficiency of IgG absorption at 7, 14, 18 and 24 h (AEA(7hr), AEA(14hr), AEA(18hr), AEA(total), respectively). In LBC, the values of serum IgG at 14, 18,24 and 48 h (13.1, 13.4, 14.1 and 14.6 mg/mL, respectively) were higher than the values at 0 and 7 h (0.04 and 6.9 mg/mL, respectively). In GC, the serum IgG at 18 h (9.3 mg/mL) was higher than the value at 7 h (5.5 mg/mL). AEA(7hr) and AEA(14hr) in LBC were the same (19.2 and 18.5%, respectively, P>0.05) and the values of AEA(18hr) and AEA(total), 9.3 and 9.5%, respectively, were equal and smaller than AEA(7hr), and AEA(14hr). In GC, AEA(7hr), 20.8%, was higher than AEA(14hr), 16.1% (P<0.05) and AEA(18hr), and AEA(total), 9.2 and 8.0%, respectively, were equal and smaller than AEA(7hr) and AEA(14hr). The serum TP and IGF-I were not affected by colostrum feeding. Considering the variables study in the present work, lyophilized bovine colostrum constitutes a promising alternative substitute to goat colostrum in newborn goat kids, since the supply of immunoglobulins and IGF-I was suitable for the kids. (c) 2012 Elsevier B.V. All rights reserved.

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Noonan syndrome (NS) and Noonan-like syndromes (NLS) are autosomal dominant disorders caused by heterozygous mutations in genes of the RAS/MAPK pathway. The aim of the study was to construct specific growth charts for patients with NS and NLS. Anthropometric measurements (mean of 4.3 measurements per patient) were obtained in a mixed cross-sectional and longitudinal mode from 127 NS and 10 NLS patients with mutations identified in PTPN11 (n?=?90), SOS1 (n?=?14), RAF1 (n?=?10), KRAS (n?=?8), BRAF (n?=?11), and SHOC2 (n?=?4) genes. Height, weight, and body mass index (BMI) references were constructed using the lambda, mu, sigma (LMS) method. Patients had birth weight and length within normal ranges for gestational age although a higher preterm frequency (16%) was observed. Mean final heights were 157.4?cm [-2.4 standard deviation score (SDS)] and 148.4?cm (-2.2?SDS) for adult males and females, respectively. BMI SDS was lower when compared to Brazilian standards (BMI SDS of -0.9 and -0.5 SDS for males and females, respectively). Patients harboring mutations in RAF1 and SHOC2 gene were shorter than other genotypes, whereas patients with SOS1 and BRAF mutations had more preserved postnatal growth. In addition, patients with RAF1 and BRAF had the highest BMI whereas patients with SHOC2 and KRAS mutations had the lowest BMI. The present study established the first height, weight, and BMI reference curves for NS and NLS patients, based only on patients with a proven molecular cause. These charts can be useful for the clinical follow-up of patients with NS and NLS. (c) 2012 Wiley Periodicals, Inc.

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In Ostariophysan fish, the detection of the alarm substance liberated into the water as a consequence of an attack by a predator elicits an alarm reaction or anti-predatory behavior. In this study, experiments were performed to: (i) describe and quantitatively characterize the behavioral and ventilatory responses in piaucu fish (Leporinus macrocephalus), individually and as part of a school, to conspecific alarm substance (CAS) and; (ii) test the effect of acute fluoxetine treatment on alarm reaction. Histological analysis revealed the presence of club cells in the intermediate and superficial layers of the epidermis. The predominant behavioral response to CAS was freezing for fish held individually, characterized by the cessation of the swimming activity as the animal settles to a bottom corner of the aquarium. Fish exposed to CAS showed decrease in the mean ventilatory frequency (approximately 13%) relative to control. In schools, CAS elicited a biphasic response that was characterized by erratic movements followed by increased school cohesion and immobility, reflected as an increased school cohesion (65.5% vs. -5.8% for controls) and in the number of animals near the bottom of the aquarium (42.0% vs. 6.5% for controls). Animals treated with single i.p. injections of fluoxetine (10 mu g/g b.w.) did not exhibit alarm behavior following CAS stimulation. These results show that an alarm pheromone system is present in piaucu fish, evidenced by the presence of epidermal club cells and an alarm reaction induced by CAS and consequently of a chemosensory system to transmit the appropriate information to neural structures responsible for initiating anti-predator behavioral responses. In addition, fluoxetine treatment caused an anxiolytic-like effect following CAS exposure. Thus, the alarm reaction in piaucu can be a useful model for neuroethological and pharmacological studies of anxiety-related states. (C) 2011 Elsevier Inc. All rights reserved.

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The efficacy of liposome-encapsulated nisin and bacteriocin-like substance (BLS) P34 to control growth of Listeria monocytogenes in Minas frescal cheese was investigated. Nisin and BLS P34 were encapsulated in partially purified soybean phosphatidylcholine (PC-1) and PC-1-cholesterol (7:3) liposomes. PC-1 nanovesicles were previously characterized. PC-1-cholesterol encapsulated nisin and BLS P34 presented, respectively, 218 nm and 158 nm diameters, zeta potential of -64 mV and -53 mV, and entrapment efficiency of 88.9% and 100%. All treatments reduced the population of L monocytogenes compared to the control during 21 days of storage of Minas frescal cheese at 7 degrees C. However, nisin and BLS P34 encapsulated in PC-1-cholesterol liposomes were less efficient in controlling L monocytogenes growth in comparison with free and PC-1 liposome-encapsulated bacteriocins. The highest inhibitory effect was observed for nisin and BLS P34 encapsulated in PC-1 liposomes after 10 days of storage of the product The encapsulation of bacteriocins in liposomes of partially purified soybean phosphatidylcholine may be a promising technology for the control of food-borne pathogens in cheeses. (C) 2012 Elsevier B.V. All rights reserved.

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Abstract Background The metabolic capacity for nitrogen fixation is known to be present in several prokaryotic species scattered across taxonomic groups. Experimental detection of nitrogen fixation in microbes requires species-specific conditions, making it difficult to obtain a comprehensive census of this trait. The recent and rapid increase in the availability of microbial genome sequences affords novel opportunities to re-examine the occurrence and distribution of nitrogen fixation genes. The current practice for computational prediction of nitrogen fixation is to use the presence of the nifH and/or nifD genes. Results Based on a careful comparison of the repertoire of nitrogen fixation genes in known diazotroph species we propose a new criterion for computational prediction of nitrogen fixation: the presence of a minimum set of six genes coding for structural and biosynthetic components, namely NifHDK and NifENB. Using this criterion, we conducted a comprehensive search in fully sequenced genomes and identified 149 diazotrophic species, including 82 known diazotrophs and 67 species not known to fix nitrogen. The taxonomic distribution of nitrogen fixation in Archaea was limited to the Euryarchaeota phylum; within the Bacteria domain we predict that nitrogen fixation occurs in 13 different phyla. Of these, seven phyla had not hitherto been known to contain species capable of nitrogen fixation. Our analyses also identified protein sequences that are similar to nitrogenase in organisms that do not meet the minimum-gene-set criteria. The existence of nitrogenase-like proteins lacking conserved co-factor ligands in both diazotrophs and non-diazotrophs suggests their potential for performing other, as yet unidentified, metabolic functions. Conclusions Our predictions expand the known phylogenetic diversity of nitrogen fixation, and suggest that this trait may be much more common in nature than it is currently thought. The diverse phylogenetic distribution of nitrogenase-like proteins indicates potential new roles for anciently duplicated and divergent members of this group of enzymes.

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Background: It is believed that schistosomes evade complement-mediated killing by expressing regulatory proteins on their surface. Recently, six homologues of human CD59, an important inhibitor of the complement system membrane attack complex, were identified in the schistosome genome. Therefore, it is important to investigate whether these molecules could act as CD59-like complement inhibitors in schistosomes as part of an immune evasion strategy. Methodology/Principal Findings: Herein, we describe the molecular characterization of seven putative SmCD59-like genes and attempt to address the putative biological function of two isoforms. Superimposition analysis of the 3D structure of hCD59 and schistosome sequences revealed that they contain the three-fingered protein domain (TFPD). However, the conserved amino acid residues involved in complement recognition in mammals could not be identified. Real-time RT-PCR and Western blot analysis determined that most of these genes are up-regulated in the transition from free-living cercaria to adult worm stage. Immunolocalization experiments and tegument preparations confirm that at least some of the SmCD59-like proteins are surface-localized; however, significant expression was also detected in internal tissues of adult worms. Finally, the involvement of two SmCD59 proteins in complement inhibition was evaluated by three different approaches: (i) a hemolytic assay using recombinant soluble forms expressed in Pichia pastoris and E. coli; (ii) complement-resistance of CHO cells expressing the respective membrane-anchored proteins; and (iii) the complement killing of schistosomula after gene suppression by RNAi. Our data indicated that these proteins are not involved in the regulation of complement activation. Conclusions: Our results suggest that this group of proteins belongs to the TFPD superfamily. Their expression is associated to intra-host stages, present in the tegument surface, and also in intra-parasite tissues. Three distinct approaches using SmCD59 proteins to inhibit complement strongly suggested that these proteins are not complement inhibitors and their function in schistosomes remains to be determined.