Characterization and stability study of a water-in-oil microemulsion incorporating quercetin

Background: The effectiveness of a water/oil (w/o) microemulsion containing quercetin against ultraviolet B radiation (UVB) induced damage was recently demonstrated by our group. However, during the development of new pharmaceutical products, the evaluation of percutaneous absorption and in vivo effectiveness should be accompanied by evaluation of stability parameters as an integral part of the process. Objective: The aim was to investigate the stability of the final microemulsion formulation considering the temperature ranges of storage and application. Methods: The physical, chemical, and functional stability of this formulation under different conditions of storage during 12 months and the photostability of quercetin incorporated into this system over UVB exposure for 7 days were evaluated. Results: Although the results indicated a notable physical stability of the w/o microemulsions during the experimental period under all employed conditions, in both, the chemical and functional studies, a significant loss of quercetin content and antioxidant activity was found after 6 months of storage at 30 degrees C/70% relative humidity and after 2 months at 40 degrees C/70% relative humidity. The photostability study results demonstrated that the incorporation of quercetin into the w/o microemulsion maintained the previously demonstrated photostability of this flavonoid under forced exposure to UVB irradiation. Conclusion: Thus, this work demonstrates that special storage conditions (at 4 +/- 2 degrees C) are necessary to maintain the functionality of the w/o microemulsion containing quercetin and mainly emphasizes the importance of studying physical, chemical, and functional parameters at the same time during stability evaluation of active principles.

Comparison of oxidation efficiency of disperse dyes by chemical and photoelectrocatalytic chlorination and removal of mutagenic activity

Degradation of Disperse Orange 1, Disperse Red 1 and Disperse Red 13 dyes has been performed using electrochemical oxidation on Pt electrode, chemical chlorination and photoelectrochemical oxidation on Ti/TiO(2) thin film electrodes in NaCl or Na(2)SO(4) medium. 100% discoloration was obtained for all tested methods after 1 h of treatment. Faster color removal was obtained by photoelectrocatalytic oxidation in 0.1 mol L(-1) NaCl pH 4.0 under UV light and an applied potential of +1.0V (vs SCE reference electrode), which indicates also values around 60% of TOC removal. The conventional chlorination method and electrochemical oxidation on Pt electrode resulted in negligible reduction of TOC removal. All dyes showed positive mutagenic activity in the Salmonella/microsome assay with the strain TA98 in the absence and presence of S9 (exogenous metabolic activation). Nevertheless, there is complete reduction of the mutagenic activity after 1 h of photoelectrocatalytic oxidation, suggesting that this process would be good option to remove disperse azo dyes from aqueous media. (C) 2008 Elsevier Ltd. All rights reserved.

A randomized and controlled trial of a participative ergonomics intervention to reduce injuries associated with manual tasks: physical risk and legislative

A participative ergonomics approach to reducing injuries associated with manual tasks is widely promoted; however only limited evidence from uncontrolled trials has been available to support the efficacy of such an approach. This paper reports on a randomized and controlled trial of PErforM, a participative ergonomics intervention designed to reduce the risks of injury associated with manual tasks. One hundred and seventeen small to medium sized food, construction, and health workplaces were audited by government inspectors using a manual tasks risk assessment tool (ManTRA). Forty-eight volunteer workplaces were then randomly assigned to Experimental and Control groups with the Experimental group receiving the PErforM program. Inspectors audited the workplaces again, 9 months following the intervention. The results showed a significant decrease in estimates of manual task risk and suggested better legal compliance in the Experimental group.

Habitual physical activity and physical activity intensity: their relation to body composition in 5.0-10.5 year old children

Background: Concerns of a decrease in physical activity levels (PALs) of children and a concurrent increase in childhood obesity exist worldwide. The exact relation between these two parameters however has as yet to be fully defined in children. Objective: This study examined the relation in 47 children, aged 5–10.5 y (mean age 8.4plusminus0.9 y) between habitual physical activity, minutes spent in moderate, vigorous and hard intensity activity and body composition parameters. Design: Total energy expenditure (TEE) was calculated using the doubly labelled water technique and basal metabolic rate (BMR) was predicted from Schofield's equations. PAL was determined by PAL=TEE/BMR. Time spent in moderate, vigorous and hard intensity activity was determined by accelerometry, using the Tritrac-R3D. Body fatness and body mass index (BMI) were used as the two measures of body composition. Results: Body fat and BMI were significantly inversely correlated with PAL (r=-0.43, P=0.002 and r=-0.45, P=0.001). Times spent in vigorous activity and hard activity were significantly correlated to percentage body fat (r=-0.44, P=0.004 and r=-0.39, P=0.014), but not BMI. Children who were in the top tertiles for both vigorous activity and hard activity had significantly lower body fat percentages than those in the middle and lowest tertiles. Moderate intensity activity was not correlated with measures of body composition. Conclusions: As well as showing a significant relation between PAL and body composition, these data intimate that there may be a threshold of intensity of physical activity that is influential on body fatness. In light of world trends showing increasing childhood obesity, this study supports the need to further investigate the importance of physical activity for children.

Purification and biochemical characterization of a thermostable extracellular glucoamylase produced by the thermotolerant fungus Paecilomyces variotii

An extracellular glucoamylase produced by Paecilomyces variotii was purified using DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration. The purified protein migrated as a single band in 7% PAGE and 8% SDS-PAGE. The estimated molecular mass was 86.5 kDa (SDS-PAGE). Optima of temperature and pH were 55 degrees C and 5.0, respectively. In the absence of substrate the purified glucoamylase was stable for 1 h at 50 and 55 degrees C, with a t(50) of 45 min at 60 degrees C. The substrate contributed to protect the enzyme against thermal denaturation. The enzyme was mainly activated by manganese metal ions. The glucoamylase produced by P. variotii preferentially hydrolyzed amylopectin, glycogen and starch, and to a lesser extent malto-oligossacarides and amylose. Sucrose, p-nitrophenyl alpha-D-maltoside, methyl-alpha-D-glucopyranoside, pullulan, alpha- and beta-cyclodextrin, and trehalose were not hydrolyzed. After 24 h, the products of starch hydrolysis, analyzed by thin layer chromatography, showed only glucose. The circular dichroism spectrum showed a protein rich in alpha-helix. The sequence of amino acids of the purified enzyme VVTDSFR appears similar to glucoamylases purified from Talaromyces emersonii and with the precursor of the glucoamylase from Aspergillus oryzae. These results suggested the character of the enzyme studied as a glucoamylase (1,4-alpha-D-glucan glucohydrolase).

Purification and biochemical characterization of a novel alpha-glucosidase from Aspergillus niveus

An extracellular alpha-glucosidase produced by Aspergillus niveus was purified using DEAE-Fractogel ion-exchange chromatography and Sephacryl S-200 gel filtration. The purified protein migrated as a single band in 5% PAGE and 10% SDS-PAGE. The enzyme presented 29% of glycosylation, an isoelectric point of 6.8 and a molecular weight of 56 and 52 kDa as estimated by SDS-PAGE and Bio-Sil-Sec-400 gel filtration column, respectively. The enzyme showed typical alpha-glucosidase activity, hydrolyzing p-nitrophenyl alpha-d-glucopyranoside and presented an optimum temperature and pH of 65A degrees C and 6.0, respectively. In the absence of substrate the purified alpha-glucosidase was stable for 60 min at 60A degrees C, presenting t (50) of 90 min at 65A degrees C. Hydrolysis of polysaccharide substrates by alpha-glucosidase decreased in the order of glycogen, amylose, starch and amylopectin. Among malto-oligosaccharides the enzyme preferentially hydrolyzed malto-oligosaccharide (G10), maltopentaose, maltotetraose, maltotriose and maltose. Isomaltose, trehalose and beta-ciclodextrin were poor substrates, and sucrose and alpha-ciclodextrin were not hydrolyzed. After 2 h incubation, the products of starch hydrolysis measured by HPLC and thin layer chromatography showed only glucose. Mass spectrometry of tryptic peptides revealed peptide sequences similar to glucan 1,4-alpha-glucosidases from Aspergillus fumigatus, and Hypocrea jecorina. Analysis of the circular dichroism spectrum predicted an alpha-helical content of 31% and a beta-sheet content of 16%, which is in agreement with values derived from analysis of the crystal structure of the H. jecorina enzyme.

Structural and Biochemical Correlates of Na(+), K(+)-ATPase Driven Ion Uptake Across the Posterior Gill Epithelium of the True Freshwater Crab, Dilocarcinus pagei (Brachyura, Trichodactylidae)

To better comprehend the structural and biochemical underpinnings of ion uptake across the gills of true freshwater crabs, we performed an ultrastructural, ultracytochemical and morphometric investigation, and kinetically characterized the Na(+), K(+)-ATPase, in posterior gill lamellae of Dilocarcinus pagei. Ultrastructurally, the lamellar epithelia are markedly asymmetrical: the thick, mushroom-shaped, proximal ionocytes contain elongate mitochondria (41% cell volume) associated with numerous (approximate to 14 mu m(2) membrane per mu m(3) cytoplasm), deep invaginations that house the Na(+), K(+)-ATPase, revealed ultracytochemically. Their apical surface is amplified (7.5 mu m(2) mu m(-2)) by stubby evaginations whose bases adjoin mitochondria below the subcuticular space. The apical membrane of the thin, distal ionocytes shows few evaginations (1.6 mu m(2) mu m(-2)), each surrounding a mitochondrion, abundant in the cytoplasm below the subcuticular space; basolateral invaginations and mitochondria are few. Fine basal cytoplasmic bridges project across the hemolymph space, penetrating into the thick ionocytes, suggesting ion movement between the epithelia. Microsomal Na(+), K(+)-ATPase specific activity resembles marine crabs but is approximate to 5-fold less than in species from fluctuating salinities, and freshwater shrimps, suggesting ion loss compensation by strategies other than Na(+) uptake. Enzyme apparent K(+) affinity attains 14-fold that of marine crabs, emphasizing the relevance of elevated K(+) affinity to the conquest of fresh water. Western blotting and biphasic ouabain inhibition disclose two alpha-subunit isoforms comprising distinct functional isoenzymes. While enzyme activity is not synergistically stimulated by NH(4)(+) and K(+), each increases affinity for the other, possibly assuring appropriate intracellular K(+) concentrations. These findings reveal specific structural and biochemical adaptations that may have allowed the establishment of the Brachyura in fresh water. J. Exp. Zool. 313A:508-523, 2010. (C) 2010 Wiley-Liss, Inc.

Inflammation and Biochemical Features of Bariatric Candidates: Does Gender Matter?

Background Accumulated fat is an accepted trigger of inflammation and metabolic syndrome but specific biochemical associations in males and females are still debated. In a prospective study, multiple variables were analyzed to search for gender-related correlations. Methods Bariatric candidates (n=94) were consecutively investigated. Age was 34.9 +/- 10.4 years (68.1% females) and body mass index (BMI) was 40.8 +/- 4.6 kg/m(2). Methods included anthropometrics, inflammatory indices (C-reactive protein (CRP), white blood cell count (WBC), ferritin) and general biochemical profile. Results Ferritin, but not CRP or WBC, was substantially more elevated in males. Serum albumin, uric acid, creatinine, and liver enzymes AST and ALT were also higher in men. Even after BMI was adjusted, all differences remained significant, and several, notably ferritin, withstood waist circumference control. Ferritin and CRP correlated with anthropometrics, glucose-related measurements, and liver enzymes, whereas WBC was only associated with triglycerides in females. Conclusions (1) Males displayed more severe inflammation according to ferritin profile, and also more signs of liver derangement; (2) all differences continued after BMI discrepancies were adjusted for, and ferritin was significant also after control of waist girth; (3) in both genders inflammatory markers often correlated with different anthropometrics, liver enzymes, and markers of glucose homeostasis; and (4) inflammatory and biochemical gender-related dissimilarities might have prognostic implications for cardiovascular risk and other comorbidities, and deserve additional studies.

Effects of the association zidovudine plus ritonavir on the liver and kidneys of pregnant rats. Morphological and biochemical aspects

Purpose: To evaluate biochemical and morphological effects on rats submitted to three different doses of the association zidovudine and ritonavir administered throughout pregnancy. Methods: Forty pregnant EPM-1 Wistar rats weighing about 200 g were randomly divided into the control group (Ctr = drug vehicle control, n = 10) and three experimental ones which were treated with an oral solution of zidovudine/ritonavir (Exp1 = 10/20 mg/kg bw, n = 10; Exp2 = 30/60 mg/kg bw, n = 10; Exp3 = 90/180 mg/kg bw, n = 10) from `day 0` up to the 20th day of pregnancy. At term (20th day) the rats were anesthetized. Blood and fetal and maternal organ samples (livers and kidneys) were taken for morphological and biochemical analyses. Results: Upon histological examinations fetal livers and kidneys appeared normal. In contrast the maternal samples revealed structural alterations. Maternal kidneys of the three experimental groups exhibited progressive and dose-dependent histological alterations; liver alterations were detected only in Exp3. Blood levels of AST and ALT were not significantly different from the control group but urea and creatinine levels were lower in groups Exp3 and Exp1. Conclusions: The administration of zidovudine plus ritonavir throughout rat pregnancy can cause morphological as well as functional changes in maternal kidneys.