Effects of creatine supplementation on glucose tolerance and insulin sensitivity in sedentary healthy males undergoing aerobic training

Recent findings have indicated that creatine supplementation may affect glucose metabolism. This study aimed to examine the effects of creatine supplementation, combined with aerobic training, on glucose tolerance in sedentary healthy male. Subjects (n = 22) were randomly divided in two groups and were allocated to receive treatment with either creatine (CT) (similar to 10g .day over three months) or placebo (PT) (dextrose). Administration of treatments was double blind. Both groups underwent moderate aerobic training. An oral glucose tolerance test (OGTT) was performed and both fasting plasma insulin and the homeostasis model assessment (HOMA) index were assessed at the start, and after four, eight and twelve weeks. CT demonstrated significant decrease in OGTT area under the curve compared to PT (P = 0.034). There were no differences between groups or over time in fasting insulin or HOMA. The results suggest that creatine supplementation, combined with aerobic training, can improve glucose tolerance but does not affect insulin sensitivity, and may warrant further investigation with diabetic subjects.

Citric acid as anti-hydration additive for magnesia containing refractory castables

Magnesia hydration is a key concern in refractory castable processing. The volumetric expansion that follows this reaction can result in cracks or even explosion during the first heating-up. Citric acid (CA) and other chelants can significantly reduce MgO hydration rate in aqueous suspensions by forming an insoluble magnesium citrate protective coating on the magnesia particles` surface. In the present work, the performance of CA as an anti-hydration additive in refractory castables was evaluated by hydration tests, mechanical strength and apparent volumetric expansion (AVE) measurements and thermogravimetry. The results attained have shown that CA effectiveness depends strongly on the amount added and by the interaction with other raw materials in the composition, in particular calcium aluminate cement. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Postharvest diseases in citrus and characterization of the fungal population in Sao Paulo`s wholesale market

The purposes of this workwere to characterize postharvest injuries and to evaluate the physicochemical characteristics of`Nra` and `Lima`oranges and `Murcott` tangor at Ceagesp market, as well as to characterize the environmental mycoflora in retail points at Ceagesp in 2006. Fruits collected at retail points were stored for 14 days at 25 degrees C and 85-90% RH. The incidence of injuries was visually evaluated every three days. The physicochemical characteristics analyzed were titratable acidity and soluble solids amount. The environmental mycoflora was sampled according to the gravimetric method, using Petri dishes containing potato-dextrose-agar medium+pentabiotic opened for two minutes. The average rot incidences in `Pera` and `Lima` oranges and `Murcott` tangor were 12.8, 14.9 and 25.8%, respectively, at the end of the storage period, and green mold was the main postharvest disease. Associations between physicochemical parameters and rot incidence was, in general, not significant. The environmental fungal population varied significantly between the sampling months in retail points with an average of 25.3 cfu/plate. Penicillium and Cladosporium were the most recorded genera of fungi. Positive correlation (r=0.96) was observed between frequency of P digitatum found in the environment of retail points and the green mold in on-sale fruits of `Pera` orange. However, for `Lima` orange and `Murcott` tangor such a correlation was not verified.

TonB-dependent outer-membrane proteins and siderophore utilization in Pseudomonas fluorescens Pf-5

The soil bacterium Pseudomonas fluorescens Pf-5 produces two siderophores, a pyoverdine and enantio-pyochelin, and its proteome includes 45 TonB-dependent outer-membrane proteins, which commonly function in uptake of siderophores and other substrates from the environment. The 45 proteins share the conserved beta-barrel and plug domains of TonB-dependent proteins but only 18 of them have an N-terminal signaling domain characteristic of TonB-dependent transducers (TBDTs), which participate in cell-surface signaling systems. Phylogenetic analyses of the 18 TBDTs and 27 TonB-dependent receptors (TBDRs), which lack the N-terminal signaling domain, suggest a complex evolutionary history including horizontal transfer among different microbial lineages. Putative functions were assigned to certain TBDRs and TBDTs in clades including well-characterized orthologs from other Pseudomonas spp. A mutant of Pf-5 with deletions in pyoverdine and enantio-pyochelin biosynthesis genes was constructed and characterized for iron-limited growth and utilization of a spectrum of siderophores. The mutant could utilize as iron sources a large number of pyoverdines with diverse structures as well as ferric citrate, heme, and the siderophores ferrichrome, ferrioxamine B, enterobactin, and aerobactin. The diversity and complexity of the TBDTs and TBDRs with roles in iron uptake clearly indicate the importance of iron in the fitness and survival of Pf-5 in the environment.

Occurrence and distribution of Vibrio parahaemolyticus in retail oysters in Sao Paulo State, Brazil

Vibrio parahaemolyticus is a potentially pathogenic bacterium that occurs naturally in estuarine environments worldwide, and is often associated with gastroenteritis in humans following consumption of raw bivalve mollusks, especially raw oysters. The occurrence of total and pathogenic V. parahaemolyticus in 74 samples of raw oysters collected in restaurants, supermarkets, groceries and beach huts in Sao Paulo State, was monitored between February 2006 and January 2007. Enumeration of V. parahaemolyticus was performed according to the most probable number (MPN) procedure. Five to ten typical colonies were selected from thiosulfate-citrate-bile salts-sucrose (TCBS) agar plates for confirmation by the presence of the species-specific gene tlh and the virulence genes tdh and trh by multiplex PCR. V. parahaemolyticus was detected in 100% of samples. The densities of total V. parahaemolyticus varied from 1.78 to 6.04 logio (MPN/g), with higher densities being detected in fall and summer, and lower densities in winter (P < 0.05). There was no statistical difference among densities of V parahaemolyticus regarding the site of collection. None of the 1943 V parahaemolyticus isolates contained tdh and/or trh. These data provide information for the assessment of exposure to V. parahaemolyticus in oysters consumed in Sao Paulo, State, Brazil. (C) 2010 Elsevier Ltd. All rights reserved.

Evaluation of aluminium tolerance in grapevine rootstocks

Aluminum (Al) toxicity is a major worldwide agricultural problem. At low pH, Al speciates into the soluble and phyto-toxic form Al(3+), inhibiting the root growth and affecting plant development. In Brazil, agriculture in acidic soils with elevated concentration of Al has significantly increased in the last decades. Therefore, in order to achieve efficient agriculture practices, the selection of plant cultivars with improved Al resistance has become crucial in this type of soils. In this work we have evaluated the Al resistance of six genotypes of grapevine rootstocks. The grapevine hardwood cuttings were grown in nutrient solution in the absence and presence of 250 and 500 mu M Al at pH 4.2. The phenotypic indexes of relative root growth, fresh and dry root weight, root area, hematoxylin staining profile, and Al content were evaluated for all six genotypes. These phenotypic indexes allowed us to identify the `Kober 5BB`, `Gravesac`, `Paulsen 1103`, and `IAC 766` grapevine rootstocks genotypes as the ones with the highest resistance to Al. Likewise, `IAC 572` and `R110` genotypes were the most Al-sensitive cultivars. We evaluated the root organic acid exudation profile in the most Al-resistant (`Kober 5BB`) and most Al-sensitive (`R110`) in plantlets cultivated in vitro in the absence and presence of 100, 200, and 400 mu M of Al. Among several compounds detected, citrate was the only organic acid related to the Al resistance phenotype observed in the `Kober 5BB` genotype. The high constitutive citrate exudation observed in `Kober 5BB` strongly suggests that exudation of this particular organic acid may impart Al-resistance/a melioration in grapevine.

Extraction of Ascorbate Oxidase from Cucurbita maxima by Continuous Process in Perforated Rotating Disc Contactor Using Aqueous Two-Phase Systems

The ascorbate oxidase is the enzyme used to determine the content of ascorbic acid in the pharmaceutical and food industries and clinics analyses. The techniques currently used for the purification of this enzyme raise its production cost. Thus, the development of alternative processes and with the potential to reduce costs is interesting. The application of aqueous two-phase system is proposed as an alternative to purification because it enables good separation of biomolecules. The objective of this study was to determine the conditions to continuously pre-purify the enzyme ascorbate oxidase by an aqueous two-phase system (PEG/citrate) using rotating column provided with perforated discs. Under the best conditions (20,000 g/mol PEG molar mass, 10% PEG concentration, and 25% citrate concentration), the system showed satisfactory results (partition coefficient, 3.35; separation efficiency, 54.98%; and purification factor, 1.46) and proved suitable for the pre-purification of ascorbate oxidase in continuous process.

Effect of natural pigments on the oxidative stability of sausages stored under refrigeration

The objective was to use natural pigments to replace sodium erythorbate (NaEry), a synthetic compound used as an antioxidant in sausage formulations, and to evaluate the oxidative stability of the samples. Six assays were prepared in which sodium erythorbate (ERY) at 0.05 g/100 g was substituted by norbixin (NOR), lycopene (LYC), zeaxanthin (ZEA), beta-carotene (CAR) or dextrose (used as a control (CON)). Physical, chemical, color, texture and sensory parameters were measured on the first day and after 45 days of storage at 4 degrees C. All pigments used in the sausage formulations were able to maintain the oxidative stability of the sausages (MDA equivalents <038 mg/kg). Zeaxanthin and norbixin were the most efficient antioxidants of those tested. This antioxidant effect might be associated with the intermediate polarities of these two compounds, which would allow them to concentrate in the membrane lipids or emulsion interface, where lipid oxidation is most prevalent. Other volatile secondary products of oxidation besides MDA should be evaluated in further studies involving natural pigments and sensory oxidative stability. (C) 2009 Elsevier Ltd. All rights reserved.

The intake of caffeine does not improve the performance of judo

The objective of this study was to investigate the ergogenic effects of caffeine on motor performance of judo female athletes. Thirteen female athletes (17.6 +/- 1.6 years, 58.3 +/- 11.4 kg, 162 +/- 4.1 cm, 22.5 +/- 4 kg/m(2)), registered in the State Federation of Judo for at least two years, participated in this study. The motor performance was assessed using the Special Judo Fitness Test (SJFT), from which was considered the number of throws in each block, the total number of throws, recovery and final heart rate (HR) and final score in SJFT. The subjects were tested in two different conditions, after ingestion of gelatin capsules of caffeine (6 mg.kg(-1)) or placebo (dextrose) 60 minutes before testing in a randomized double-blind, crossover study. The number of throws in each block did not differs between the caffeine (CAF) and placebo (PL) conditions (Block A: 4.53 +/- 0.51 CAF and 4.46 +/- 0.51 PL; Block B: 8.3 +/- 0.63 CAF and 8.23 +/- 0.72 PL; Block C: 7.23 +/- 0.59 CAF and 7.46 +/- 0.77 PL), as well as the total number of throws (20.07 +/- 1.18 CAF and 20.15 +/- 1.67 PL), HR (Final: 190.3 +/- 9.63 bpm CAF and 190.69 +/- 9.19 bpm PL; Recovery 162.07 +/- 13.78 bpm CAF and 164.3 +/- 9.64 bpm PL) and final score in SJFT (17.59 +/- 1.4 CAF and 17.75 +/- 1.98 PL). Ingestion of caffeine did not improve performance during high intensity and short duration exercise in judo fighters

Antioxidant activity of flavonoids in isolated mitochondria

Mitochondria are important intracellular sources and targets of reactive oxygen species (ROS), while flavonoids, a large group of secondary plant metabolites, are important antioxidants. Following our previous study on the energetics of mitochondria exposed to the flavonoids quercetin, taxifolin, catechin and galangin, the present work addressed the antioxidant activity of these compounds (1-50 mu mol/L) on Fe2+/citrate-mediated membrane lipid peroxidation (LPO) in isolated rat liver mitochondria, running in parallel studies of their antioxidant activity in non-organelle systems. Only quercetin inhibited the respiratory chain of mitochondria and only galangin caused uncoupling. Quercetin and galangin were far more potent than taxifolin and catechin in affording protection against LPO (IC50 = 1.23 +/- 0.27 and 2.39 +/- 0.79 mu mol/L, respectively), although only quercetin was an effective scavenger of both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals. These results, together with the previous study, suggest that the 2,3-double bond in conjugation with the 4-oxo function in the flavonoid structure are major determinants of the antioxidant activity of flavonoids in mitochondria, the presence of an o-di-OH structure on the B-ring, as occurs in quercetin, favours this activity via superoxide scavenging, while the absence of this structural feature in galangin, favours it via a decrease in membrane fluidity and/or mitochondrial uncoupling. Copyright (c) 2008 John Wiley & Sons, Ltd.

Iron chelating-mediated antioxidant activity of Plectranthus barbatus extract on mitochondria

Plectranthus barbatus Andrews (Lamiaceae) is a popular medicinal plant used to treat gastrointestinal and hepatic ailments. In this work, we assessed the antioxidant activity of the aqueous extract of P. barbatus leaves on Fe(2+)-citrate-mediated membrane lipid peroxidation in isolated rat liver mitochondria, as well in non-mitochondrial systems: DPPH reduction, (center dot)OH scavenging activity, and iron chelation by prevention of formation of the Fe(2+)-bathophenanthroline disulfonic acid (BPS) complex. Within all the tested concentrations (15-75 mu g/ml), P. barbatus extract presented significant free radical-scavenging activity (IC(50) = 35.8 +/- 0.27 mu g/ml in the DPPH: assay and IC(50) = 69.1 +/- 0.73 mu g/ml in the (center dot)OH assay) and chelated iron (IC(50) = 30.4 +/- 3.31 mu g/ml). Over the same concentration range, the plant extract protected mitochondria against Fe(2+)/citrate-mediated swelling and malondialdehyde production, a property that persisted even after simulation of its passage through the digestive tract. These effects could be attributed to the phenolic compounds, nepetoidin - caffeic acid esters, present in the extract. Therefore, P. barbatus extract prevents mitochondrial membrane lipid peroxidation, probably by chelation of iron, revealing potential applicability as a therapeutic source of molecules against diseases involving mitochondrial iron overload. (C) 2010 Elsevier Ltd. All rights reserved.

In vitro studies of cutaneous retention of magnetic nanoemulsion loaded with zinc phthalocyanine for synergic use in skin cancer treatment

In this study was developed a new nano drug delivery system (NDDS) based on association of biodegradable surfactants with biocompatible magnetic fluid of maguemita citrate derivative. This formulation consists in a magnetic emulsion with nanostructured colloidal particles. Preliminary in vitro experiments showed that the formulation presents a great potential for synergic application in the topical release of photosensitizer drug (PS) and excellent target tissue properties in the photodynamic therapy (PDT) combined with hyperthermia (HPT) protocols. The physical chemistry characterization and in vitro assays were carried out by Zn(II) Phtalocyanine (ZnPc) photosensitizer incorporated into NDDS in the absence and the presence of magnetic fluid, showed good results and high biocompatibility. In vitro experiments were accomplished by tape-stripping protocols for quanti. cation of drug association with different skin tissue layers. This technique is a classical method for analyses of drug release in stratum corneum and epidermis+ dermis skin layers. The NDDS formulations were applied directly in pig skin (tissue model) fixed in the cell`s Franz device with receptor medium container with a PBS/EtOH 20% solution (10mM, pH 7.4) at 37 degrees C. After 12 h of topical administration stratum corneum was removed from fifty tapes and the ZnPc retained was evaluated by solvent extraction in dimetil-sulphoxide under ultrasonic bath. These results indicated that magnetic nanoemulsion (MNE) increase the drug release on the deeper skin layers when compared with classical formulation in the absence of magnetic particles. This could be related with the increase of biocompatibility of NDDS due to the great affinity for the polar extracelullar matrix in the skin and also for the increase in the drug partition inside of corneocites wall. (C) 2008 Elsevier B.V. All rights reserved.

Myotoxic phospholipases A(2) isolated from Bothrops brazili snake venom and synthetic peptides derived from their C-terminal region: Cytotoxic effect on microorganism and tumor cells

This paper reports the purification and biochemical/pharmacological characterization of two myotoxic phospholipases A(2) (PLA(2)S) from Bothrops brazili venom, a native snake from Brazil. Both myotoxins (MTX-I and II) were purified by a single chromatographic step on a CM-Sepharose ion-exchange column up to a high purity level, showing M-r similar to 14,000 for the monomer and 28,000 Da for the dimer. The N-terminal and internal peptide amino acid sequences showed similarity with other myotoxic PLA2S from snake venoms, MTX-I belonging to Asp49 PLA(2) class, enzymatically active, and MTX-II to Lys49 PLA(2)S, catalytically inactive. Treatment of MTX-I with BPB and EDTA reduced drastically its PLA(2) and anticoagulant activities, corroborating the importance of residue His48 and Ca2+ ions for the enzymatic catalysis. Both PLA(2)S induced myotoxic activity and dose-time dependent edema similar to other isolated snake venom toxins from Bothrops and Crotalus genus. The results also demonstrated that MTXs and cationic synthetic peptides derived from their 115-129 C-terminal region displayed cytotoxic activity on human T-cell leukemia (JURKAT) lines and microbicidal effects against Escherichia coli, Candida albicans and Leishmania sp. Thus, these PLA(2) proteins and C-terminal synthetic peptides present multifunctional properties that might be of interest in the development of therapeutic strategies against parasites, bacteria and cancer. (C) 2008 Elsevier Inc. All rights reserved.

Visible light during mycelial growth and conidiation of Metarhizium robertsii produces conidia with increased stress tolerance

Light conditions during mycelial growth are known to influence fungi in many ways. The effect of visible-light exposure during mycelial growth was investigated on conidial tolerance to UVB irradiation and wet heat of Metarhizium robertsii, an insect-pathogenic fungus. Two nutrient media and two light regimens were compared. Conidia were produced on (A) potato dextrose agar plus yeast extract medium (PDAY) (A1) under dark conditions or (A2) under continuous visible light (provided by two fluorescent lamps with intensity 5.4 W m-2). For comparison, the fungus was also produced on (B) minimal medium (MM) under continuous-dark incubation, which is known to produce conidia with increased tolerance to heat and UVB radiation. The UVB tolerances of conidia produced on PDAY under continuous visible light were twofold higher than conidia produced on PDAY medium under dark conditions, and this elevated UVB tolerance was similar to that of conidia produced on MM in the dark. The heat tolerance of conidia produced under continuous light was, however, similar to that of conidia produced on MM or PDAY in the dark. Conidial yield on PDAY medium was equivalent when the fungus was grown either under continuous-dark or under continuous-light conditions.

Biotype stability of Candida albicans isolates after culture storage determined by randomly amplified polymorphic DNA and phenotypical methods

P>Typing methods to evaluate isolates in relation to their phenotypical and molecular characteristics are essential in epidemiological studies. In this study, Candida albicans biotypes were determined before and after storage in order to verify their stability. Twenty C. albicans isolates were typed by Randomly Amplified Polymorphic DNA (RAPD), production of phospholipase and proteinase exoenzymes (enzymotyping) and morphotyping before and after 180 days of storage in Sabouraud dextrose agar (SDA) and sterilised distilled water. Before the storage, 19 RAPD patterns, two enzymotypes and eight morphotypes were identified. The fragment patterns obtained by RAPD, on the one hand, were not significantly altered after storage. On the other hand, the majority of the isolates changed their enzymotype and morphotype after storage. RAPD typing provided the better discriminatory index (DI) among isolates (DI = 0.995) and maintained the profile identified, thereby confirming its utility in epidemiological surveys. Based on the low reproducibility observed after storage in SDA and distilled water by morphotyping (DI = 0.853) and enzymotyping (DI = 0.521), the use of these techniques is not recommended on stored isolates.