In vivo CYP2E1 phenotyping as a new potential biomarker of occupational and experimental exposure to benzene

Assessing CYP2E1 phenotype in vivo may be important to predict individual susceptibility to those chemicals, including benzene, which are metabolically activated by this isoenzyme. Chlorzoxazone (CHZ), a specific CYP2E1 substrate, is readily hydroxylated to 6-OH-chlorzoxazone (6-OH-CHZ) by liver CYP2E1 and the metabolic ratio 6-OH-CHZ/CHZ in serum (MR) is a specific and sensitive biomarker of CYP2E1 activity in vivo in humans. We used this MR as a potential biomarker of effect in benzene-treated rats and, also, in humans occupationally exposed to low levels of benzene. Male Sprague-Dawley rats (375-400 g b.w.) were treated i.p. for 3 days with either a 0.5 ml solution of benzene (5 mmol/kg b.w.) in corn oil, or 0.5 ml corn oil alone. Twenty-four hours after the last injection, a polyethylene glycol (PEG) solution of CHZ (20 mg/kg b.w.) was injected i.p. in both treated and control animals. After 2, 5.10,15, 20,30,45, 60, 90, 120, 180, and 240 min from injection, 0.2 ml blood was taken from the tip tail and stored at -20 degrees C until analysis. A modified reverse phase HPLC method using a 5 mu m Ultrasphere C18 column equipped with a direct-connection ODS guard column, was used to measure CHZ and its metabolite 6-OH-CHZ in serum. No statistically significant difference in the MR was observed, at any sampling time, between benzene-treated and control rats. The concentration-versus-time area under the curve (AUC), however, was lower (p < 0.05, Mann-Whitney test), whereas the systemic clearance was higher (p < 0.05) in treated than in control rats. Eleven petrochemical workers occupationally exposed to low levels of airborne benzene (mean +/- SD, 25.0 +/- 24.4 mu g/m(3)) and 13 non-exposed controls from the same factory (mean +/- SD, 6.7 +/- 4.0 mu g/m(3)) signed an informed consent form and were administered 500 mg CHZ p.o. Two hours later a venous blood sample was taken for CHZ and 6-OH-CHZ measurements. Despite exposed subjects showed significantly higher levels of t,t-MA and S-PMA, two biomarkers of exposure to benzene, than non-exposed workers, no difference in the MR mean values +/- SD was found between exposed (0.59 +/- 0.29) and non-exposed (0.57 +/- 0.23) subjects. So, benzene was found to modify CHZ disposition, but not CYP2E1 phenotype in benzene-treated rats, nor in workers exposed to benzene, probably due to the levels of exposure being too low. (C) 2009 Elsevier B.V. All rights reserved.

Tradução, adaptação cultural e propriedades psicométricas da versão brasileira do Short-Form of the Mobility Assessment Tool (MAT-sf)

Objectives: to translate and assess the psychometric properties of the Brazilian short-form of the Mobility Assessment Tool (MAT-sf) in Brazilians community elderly. Methds: the 12 items MAT-sf went through the process of translation and back translation into Portuguese of the Brazil, considering the semantic and cultural adaptation. In a sample of 150 aged 65-74 years living in the community, the instrument's psychometric properties were evaluated by analysis of convergent and construct validity and test-retest reliability. The main outcomes measures used for validation included in the battery of tests of physical ability, self-repor measures of functional limitations, health, depression, cognitive and sex. The test-retest reliability of the instrument was assessed using the intra-class correlation coefficient (ICC), 40 subjects were reassessed after an interval of 14 days of assessment. Results: the concurrent validity for the MAT-sf was evidenced by significant correlations with SPPB (r = 0,53), number of functional limitations (r = -0,62) and depressive symptoms (r = -0,45). The construct validity of the instrument was measured by gradual and significant increase of the MAT-sf scores with high levels of physical performance and with positive self-reported health, also found that MAT-sf scores were statistically differents according to sex. The variation in MAT-sf scores (R2 = 0,41) was explained by SPPB, number of limitations for activities of daily life and depressive symptoms. High values for test-retest reliability was evidencend by ICC = 0,94, 95% CI = 0,90 0,97. Conclusions: the Brazilian version of the short-form of the Mobility Assessment Tool has values of validity and reliability to ensure its use in elderly populations living in communities

Study of interstitial oxygen mobility in RuSr2GdCu2O8 by internal friction

The discovery of the spatial uniform coexistence of superconductivity and ferromagnetism in ruthenocuprates, RuSr2GdCu2O8 (Ru-1212), has spurred an extraordinary development in the study of the competition between magnetism and superconductivity. However, several points of their preparation process and characterization that determine their superconductive behaviour are still obscure. The improvement of sample preparation conditions involves some thermal treatments in inert atmosphere. Anelastic spectroscopy measurements were made using an inverted torsion pendulum, operating with an oscillation frequency of 38 Hz, temperature in the 90 and 310 K range, heating rate of 1 K/min, and vacuum better than 10(-3) Pa. The results show anelastic relaxation peaks at 210 K related to the presence of interstitial oxygen atoms. The peaks decrease significantly with the oxygen loss caused by the heat treatments in vacuum, appearing again after the annealing of the sample in an oxygen atmosphere. These observed peaks are clearly related to the additional oxygen atoms, with activation energy 0.13 and 0.36 eV, and can be explained in terms by diffusional jumps of interstitial oxygen in the RuO2 planes. (C) 2009 Elsevier B.V. All rights reserved.

Quantitative comparison of mobility and gross motor function in Brazilian children with cerebral palsy

Background: Cerebral palsy (CP) presents changes in posture and movement as a core characteristic, which requires therapeutic monitoring during the habilitation or rehabilitation of children. Besides clinical treatment, it is fundamental that professionals use systems of evaluation to quantify the difficulties presented to the individual and assist in the organization of a therapeutic program. The aim of this study was to quantitatively verify the performance of children with spastic di-paresia type CP.Methods: The Pediatric Evaluation of Disability Inventory (PEDI) and Gross Motor Function Classification System (GMFM) tests were used and classification made through the GMFCS in the assessment of 7 patients with CP, 4 females and 3 males, average age of 9 years old.Results: According to GMFCS scales, 17% (n=1) were level II and 83% (n=6) were level III. The PEDI test and 88 GMFM items were used in the area of mobility. We observed that there was high correlation between mobility and gross motor function with Pearson's correlation coefficient =0.929) showing the likely impact of these areas in the functional skills and the quality of life of these patients.Conclusion: We suggest the impact of the limitation of the areas in functional skills and quality of life of these patients.

The HUman MicroNucleus project on eXfoLiated buccal cells (HUMNXL): The role of life-style, host factors, occupational exposures, health status, and assay protocol

The human buccal micronucleus cytome assay (BMCyt) is one of the most widely used techniques to measure genetic damage in human population studies. Reducing protocol variability, assessing the role of confounders, and estimating a range of reference values are research priorities that will be addressed by the HUMNXL, collaborative study. The HUMNXL, project evaluates the impact of host factors, occupation, life-style, disease status, and protocol features on the occurrence of MN in exfoliated buccal cells. In addition, the study will provide a range of reference values for all cytome endpoints. A database of 5424 subjects with buccal MN values obtained from 30 laboratories worldwide was compiled and analyzed to investigate the influence of several conditions affecting MN frequency. Random effects models were mostly used to investigate MN predictors. The estimated spontaneous MN frequency was 0.74 parts per thousand (95% CI 0.52-1.05). Only staining among technical features influenced MN frequency, with an abnormal increase for non-DNA-specific stains. No effect of gender was evident, while the trend for age was highly significant (p < 0.001). Most occupational exposures and a diagnosis of cancer significantly increased MN and other endpoints frequencies. MN frequency increased in heavy smoking (>= 40 cig/day. FR = 1.37:95% CI 1.03-.82) and decreased with daily fruit consumption (FR = 0.68; 95% CI 0.50-0.91). The results of the HUMNXL, project identified priorities for validation studies, increased the basic knowledge of the assay, and contributed to the creation of a laboratory network which in perspective may allow the evaluation of disease risk associated with MN frequency. (C) 2011 Elsevier B.V. All rights reserved.

Association between distressing non-work-related events and occupational injuries

The following is a report on a case-control study whose objective was to investigate the association between distressing non-work-related events and occupational injures. Ninety three injured workers (cases) were matched with 372 non-injured controls in a large metallurgical factory in southeastern Brazil. Exposure to distressing non-work-related events was measured through a questionnaire focusing on situations pertaining to personal problems unrelated to work activities. The data were analyzed by adjusting a conditional logistic regression model, where occurrence of the work injury was the dependent dichotomous variable and answers from the questionnaire were independent continuous variables. The analysis showed an association between some distressing non-work-related events and occupational injuries. These findings imply expanding the horizon of preventive measures used in targeting. work injuries which have traditionally been focused on the control of strictly workplace risks.

Fraction of work-related accidents attributable to occupational noise in the city of Botucatu, São Paulo, Brazil

Background: Noise is the most common agent of occupational exposure. It may induce both auditory and extraauditory dysfunction and increase the risk of work accidents. The purpose of this study was to estimate the fraction of accidents attributable to noise occupational exposure in a mid-size city located in southeastern Brazil. Materials and Methods: In this population case-control study, which included 108 cases and 324 controls, the incidence rate ratio of work accidents controlled for several covariables was obtained by classifying occupational noise exposure into three levels, as well as determining the prevalence in each level. Results: Based on these data, the attributable fraction was estimated as 0.6391 (95 CI = 0.2341-0.3676), i.e., 63 of the work accidents that took place in the study site were statistically associated with occupational noise exposure. Discussion: The causes of this association as well as its implications in the prevention of work accidents are discussed.

Mobility, Aesthetic, Implants, and Satisfaction of the Ocular Prostheses Wearers

During the process of facial rehabilitation, the mobility of ocular prostheses must be considered. Whereas some factors depend exclusively on the dentist, such as molding techniques and selection of material for denture construction, regarding ocular rehabilitation, factors, such as type of surgery, whether to adopt implants, and the use of lubricants, deserve special attention owing to their integration and their association with other factors pertaining exclusively to the patient. To establish harmony, and with the intention of aiding the dentist, after a discerning evaluation, the authors of this study report the factors that provide greater or less mobility to ocular prostheses and conceal the prosthesis in a more natural way, thereby contributing toward achieving a favorable aesthetic result in rehabilitations.

Suggestion of an inverse relationship between perception of occupational risks and work-related injuries

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

Oxygen mobility and structural phase transformation in Bi2Sr2CaCu2O8+delta measured by anelastic spectroscopy

One of the most studied ceramic superconductors for application has been, undoubtedly, Bi2Sr2CaCu2O8+delta. Although being a multiphasic material, it has proved to have great advantages compared to other ceramic systems. Measurements of the elastic energy loss and modulus (anelastic spectroscopy) as a function of temperature call distinguish among different atomic jumps that occur inside the various phases or at different local ordering. In this paper, mechanical loss spectra of Bi2Sr2CaCu2O8+delta bar shaped samples, made by a conventional method, have been measured between 80 and 600 K, using a torsion pendulum operating in frequencies below 50 Hz, for samples annealed in vacuum up to 600 K. Possible relaxation mechanisms are proposed to explain the origin of the mechanical-loss peaks observed 300 and 500 K. (C) 2004 Elsevier B.V. All rights reserved.

Sampling mobility index: Case study in Assis - Brazil

The objective of this work is to present an index which may synthesize a set of indicators of mobility for medium size cities urban centers. Three great areas were selected to compose the mobility index: pedestrians, motor vehicles and cycling. The Sampling Mobility Index is given by the sum of the punctuation the indicators selected and can to result in 700 points, the best result to mobility, and 0 points, the worse to mobility. The result obtained is given by the Sampling Mobility Index equal to 390. This result indicates a critical situation in Assis, as far as mobility is concerned. (c) 2005 Elsevier Ltd. All rights reserved.

Correlation between the mobility of spin-labeled peptide chains and resin solvation: An approach to optimize the synthesis of aggregating sequences

Resin solvation properties affect the efficiency of the coupling reactions in solid-phase peptide synthesis. Here we report a novel approach to evaluate resin solvation properties, making use of spin label electron paramagnetic resonance (EPR) spectroscopy. The aggregating VVLGAAIV and ING sequences were assembled in benzhydrylamine-resin with different amino group contents (up to 2.6 mmol/g) to examine the extent of chain association within the beads. These model peptidyl-resins were first labeled at their N-terminus with the amino acid spin label 2,2,6,6-tetramethylpiperidine-N-oxyl-4-amino-4-carboxylic acid (Toac). Their solvation properties in different solvents were estimated, either by bead swelling measurement or by assessing the dynamics of their polymeric matrixes through the analysis of Toac EPR spectra, and were correlated with the yield of the acylation reaction. In most cases the coupling rate was found to depend on bead swelling. Comparatively, the EPR approach was more effective. Line shape analysis allowed the detection of more than one peptide chain population, which influenced the reaction. The results demonstrated the unique potential of EPR spectroscopy not only for improving the yield of peptide synthesis, even in challenging conditions, but also for other relevant polymer-supported methodologies in chemistry and biology.

Structure, mobility and clustering of interstitial O in La2CuO4+delta in the limit of small delta

Anelastic spectra (elastic energy absorption as a function of temperature) are reported which provide evidence that excess O in La2CuO4+delta starts forming two different types of defects already at very low concentrations, where no phase separation or changes in the type of O intercalation are believed to occur. The absorption peak with the lowest activation enthalpy, H/k(B) = 5600 K, is visible at lowest values of delta and is attributed to the hopping of single interstitial O2- ions. The second process, with a slightly slower dynamics, appears at higher values of delta and soon becomes preponderant over the former process. The latter process is proposed to be due to stable pairs of O atoms and is put in connection with the formation of partially covalent bonds between interstitial and apical oxygen; such bonds would reduce the doping efficiency of excess O at increasing delta. The geometry of the interstitial O defect is discussed. O 1998 Published by Elsevier B.V. B.V. All rights reserved.

Interstitial oxygen mobility in superconducting samples of Bi2Sr2CaCu2O8+y

Since high-temperature superconductors were discovered, several studies have been made on their physical properties, attempting to associate them to the origin of superconductivity. Obviously, the oxygen atoms interstitially dissolved in the matrix have an important role in superconductivity, since they move easily in the lattice. In addition, they contribute to hole creation in the CuO2 planes. Anelastic spectroscopy ( internal friction) measurements are sensitive tools for the study of defects in solids, in particular for oxygen mobility. In this paper, Bi2Sr2CaCu2O8+y samples with several different amounts of interstitial oxygen were analysed by means of anelastic spectroscopy measurements. The measurements were performed by using a torsion pendulum operating at a frequency of about 40 Hz. Complex relaxation structures were observed and attributed to the shift of the oxygen interstitial atoms in BiO chains.