Serological screening and toxoplasmosis exposure factors among pregnant women in South of Brazil

Serological screening and evaluation of exposure factors for Toxoplasma gondii transmission were conducted in 2126 pregnant women from southern Brazil. Specific antibodies against Toxoplasma gondii were presented by 74.5% (n=1583) of the pregnant women evaluated. Contact with soil was found to be the major factor for infection.

Heavy metal contamination in seafood and consumer exposure in the Gulf Cooperation Council

Disserta����o para obten����o do Grau de Mestre em Tecnologia e Seguran��a Alimentar

Human exposure to potential rabies virus transmitters in Olinda, State of Pernambuco, between 2002 and 2006

The aim of the present study was to evaluate the data on human exposure to potential rabies virus transmitters in Olinda, State of Pernambuco, Brazil. Data from 7,062 patients who underwent antirabies prophylactic treatment in Olinda between 2002 and 2006 were analyzed. As expected, dogs and cats were involved in most of the cases; i.e. 82.3 and 16.3%, respectively. Attacks by nonhuman primates, bats and other species (unspecified) were also reported. Among the 7,062 patients who underwent antirabies treatment, 582 patients abandoned the treatment, either by indication from the health unit (195) or by their own decision (387). In conclusion, this study has indicated that prophylaxis for human rabies in this urban area will require a multifaceted approach, including health education, post-exposure prophylaxis, systematic vaccination for dogs and cats, and possibly selective control over wild animals such as hematophagous bats.

Gold nanoparticles for the detection of DNA adducts as biomarkers of exposure to acrylamide

The main objective of this thesis was the development of a gold nanoparticle-based methodology for detection of DNA adducts as biomarkers, to try and overcome existing drawbacks in currently employed techniques. For this objective to be achieved, the experimental work was divided in three components: sample preparation, method of detection and development of a model for exposure to acrylamide. Different techniques were employed and combined for de-complexation and purification of DNA samples (including ultrasonic energy, nuclease digestion and chromatography), resulting in a complete protocol for sample treatment, prior to detection. The detection of alkylated nucleotides using gold nanoparticles was performed by two distinct methodologies: mass spectrometry and colorimetric detection. In mass spectrometry, gold nanoparticles were employed for laser desorption/ionisation instead of the organic matrix. Identification of nucleotides was possible by fingerprint, however no specific mass signals were denoted when using gold nanoparticles to analyse biological samples. An alternate method using the colorimetric properties of gold nanoparticles was employed for detection. This method inspired in the non-cross-linking assay allowed the identification of glycidamide-guanine adducts and DNA adducts generated in vitro. For the development of a model of exposure, two different aquatic organisms were studies: a goldfish and a mussel. Organisms were exposed to waterborne acrylamide, after which mortality was recorded and effect concentrations were estimated. In goldfish, both genotoxicity and metabolic alterations were assessed and revealed dose-effect relationships of acrylamide. Histopathological alterations were verified primarily in pancreatic cells, but also in hepatocytes. Mussels showed higher effect concentrations than goldfish. Biomarkers of oxidative stress, biotransformation and neurotoxicity were analysed after prolonged exposure, showing mild oxidative stress in mussel cells, and induction of enzymes involved in detoxification of oxygen radicals. A qualitative histopathological screening revealed gonadotoxicity in female mussels, which may present some risk to population equilibrium.

Distribution of hepatitis C virus genotypes among different exposure categories in the State of Par��, Brazilian Amazon

INTRODUCTION: Epidemiological studies concerning HCV genotypic distribution in the Brazilian Amazon are scarce. Thus, this study determined the patterns of distribution of HCV genotypes among different exposure categories in the State of Par��, Brazilian Amazon. METHODS: A cross-sectional study was conducted on 312 HCV-infected individuals belonging to different categories of exposure, who were attended at the HEMOPA, CENPREN and a private hemodialysis clinic in Bel��m. They were tested for HCV antibodies using an immunoenzymatic test, RNA-HCV, using real-time PCR and HCV genotyping through phylogenetic analysis of the 5' UTR. The population groups were epidemiologically characterized according to data collected in a brief interview or medical consultation. RESULTS: Genotype 1 predominated in all the different categories of HCV exposure. HCV genotypic distribution among blood donors comprised genotypes 1 (94%) and 3 (6%). All patients with chronic hematologic diseases had HCV genotype 1. The genotypic distribution in illicit-drug users comprised genotypes 1 (59.6%) and 3 (40.4%). In patients under hemodialysis, genotypes 1 (90.1%), 2 (3.3%), and 3 (6.6%) were detected. Finally, the frequency of genotypes 1 and 3 was significantly different between the groups: BD and DU, PUH and DU, PUH and PCHD and PCHD and DU. CONCLUSIONS: The genotypic frequency and distribution of HCV in different categories of exposure in the State of Par�� showed a predominance of genotype 1, regardless of the possible risk of infection.

Ultrastructural study on the morphological changes to male worms of Schistosoma mansoni after in vitro exposure to allicin

INTRODUCTION: Garlic has a wide range of actions, including antibacterial, antiviral, antifungal, antiprotozoal and anthelmintic actions. This antiparasitic activity has been attributed to allicin, which is the main constituent of garlic. The present study aimed to investigate the in vitro activity of allicin on the tegument of adult Schistosoma mansoni worms using scanning electron microscopy. METHODS: Swiss Webster mice were infected with S. mansoni cercariae (100 per mouse) and sacrificed 50 days later to acquire the adult worms. These worms were collected by perfusion and placed in RPMI medium 1,640 at 37��C before transferring to RPMI media containing 0 (control), 5, 10, 15 and 20mg/mL of allicin, where they were incubated for 2h. The worms were fixed in 2.5% glutaraldehyde solution, washed twice, post-fixed in osmium tetroxide, washed twice and then dehydrated with ascending grades of ethanol. The samples were air-dried, mounted on stubs, gold coated in an ion sputtering unit and viewed using a scanning electron microscope. RESULTS: A concentration of 5mg/mL caused wrinkling in the tegument; a concentration of 10mg/mL resulted in changes to tubercles and loss or modification of spines. With 15 and 20mg/mL increasing damage to the tegument could be seen, such as vesicle formation and the presence of ulcers. CONCLUSIONS: These findings demonstrate the effect of allicin on adult S. mansoni worms and indicate that most of the changes occur at concentrations greater than that normally indicated for treatment.

Understanding multi-asset factor models: Factor exposure interpretation

Field lab: Business project

Systematic design analysis and risk management on engineered nanoparticles occupational exposure

The production of nanotechnology-based products is increasing, along with the conscience of the possible harmful effects of some nanomaterials. The ���safety-by-design��� approaches are getting attention as helpful tools to develop safer products and production processes. The Systematic Design Analysis Approach could help to identify the solutions to control the workplace risks by defining the emission and exposure scenarios and the possible barriers to interrupt them. By applying this approach in a photocatalytic ceramic tiles development project it was possible to identify relevant nanoparticles emission scenarios and related barriers, and defining possible ways to reduce it.

Mitigating the impact of occupational noise exposure for elderly workers: Setting the functional requirements for an ANC system

Noise affects people in very different aspects and in almost every aspect of our daily life. The most prominent impact of noise exposure is hearing loss. However, it can also impair people at their work settings due to other effects rather than hearing loss. Older works tend to be more susceptible to noise exposure effects at work, firstly because most of them already have some ���natural��� hearing loss, as a results of the ageing process, and secondly because they also tend to be more susceptible at an psychological level. The current study is an attempt to describe the potential problem and to make a survey to identify the available active noise cancelation systems, as well as to specific the main requirements of this type of systems to be applied in such contexts. Several aspects of characteristics of the ANC systems were identified and are presented in this study. From the obtained results it was possible to have a clearer idea about the potential of this technology, and to confirm that this type of solution can be extremely important as a component of an active ageing program, as the preservation of hearing will also impact on the social life of the exposed workers.

Contribution of the evaluation strategy and the use of hearing protection for the uncertainty associated with occupational exposure to noise

Doctoral Thesis for PhD degree in Industrial and Systems Engineering

Physiological responses of matrinx�� (Brycon amazonicus) fed different levels of vitamin C and submitted to air exposure

The role of vitamin C on physiological responses of matrinx�� (Brycon amazonicus) submitted to air exposure was analyzed. Nine hundred fish (70.15 g) were distributed in fifteen 500 l boxes (60 fish.box-1) and fed five rations (treatments): Control (no vitamin C); T100 (100 mg); T200 (200 mg); T400 (400 mg) and T800 (800 mg of vitamin C kg.ration-1). Each ration was offered to fish of three boxes during 60 days before the stress challenge that consisted of exposing fish to air for two minutes. Samplings were carried out for 5, 15, 30 and 60 minutes after the air exposure. Blood was collected for glucose, cortisol, total protein, sodium, chloride, hematocrit, hemoglobin determination, and white and red cell count. Liver was removed for hepatosomatic index (HSI) calculation and glycogen determination. Vitamin C did not affect the levels of cortisol, chloride, total protein, hemoglobin, leukocytes, hepatic glycogen or HSI in air exposed fish. Blood glucose levels elevation observed 60 minutes after the challenge did not depend on the levels of vitamin C, nor did the drop in serum sodium levels verified 60 minutes after stressor. In general, hematocrit did not change by effect of vitamin C but it was lower at 15 and 30 minutes after the challenge. The number of erythrocytes decreased in fish after 5 minute sampling in all treatments, especially at 30 and 60 minutes. The air exposure evoked alterations in stress indicators of matrinx��, and the vitamin C did not alter the responses.

A new page on the road book of inorganic mercury in fish body - tissue distribution and elimination following waterborne exposure and post-exposure periods

prova tipogr��fica / uncorrected proof

Exposici��n prenatal al alcohol y s��ndrome de hiperactividad con d��ficit de la atenci��n: un abordaje conductual, farmacol��gico y bioqu��mico. Alcohol prenatal exposure and attention deficit with hyperactivity disorder: behavioral, pharmacological and biochemical approaches.

El Trastorno por D��ficit de Atenci��n con Hiperactividad (ADHD) es un s��ndrome conductual de origen org��nico, que se manifiesta principalmente en ni��os. Est�� caracterizado por distracci��n moderada a severa, per��odos de atenci��n breve, hiperactividad, inestabilidad emocional e impulsividad. Los tratamientos se basan "parad��jicamente" en psicoestimulantes. Las sustancias mas empleadas son metilfenidato y anfetamina. La sintomatolog��a indica un mal funcionamiento en los circuitos dopamin��rgicos que ser��a el resultado de factores gen��ticos como ambientales, ya que es com��n encontrar ADHD en ni��os expuestos prenatalmente al alcohol. Los modelos animales son importantes para estudiar patolog��as de etiolog��a desconocida, en este sentido, estudios de nuestro laboratorio indican que ratones deficientes en p35 son hiperactivos y responden paradojalmente a psicoestimulantes. Cdk5/p35 participa en el desarrollo neuronal, liberaci��n de ves��culas, se��ales dopamin��rgicas, etc. Adem��s resultados preliminares indican que la experiencia prenatal con una dosis et��lica moderada durante la gestaci��n tard��a, es suficiente para incrementar los patrones de actividad locomotora, semejantes a los descriptos en los modelos animales de ADHD. De acuerdo a estas consideraciones hipotetizamos que la exposici��n et��lica prenatal a dosis moderadas y durante un periodo acotado de la gestaci��n tard��a, resulta en un patr��n conductual similar al descripto en modelos de ADHD. Asimismo, drogas psicoestimulantes pueden revertir dichos efectos. Por otra parte, proponemos que estas alteraciones son consecuencia de los efectos ocasionados por el insulto et��lico sobre el equilibrio en el funcionamiento del sistema de neurotransmisi��n dopamin��rgio mesol��mbico/cortical. Teniendo en cuenta que la etiolog��a del ADHD aun no se conoce, el desarrollo de modelos animales, que recapitulen caracter��sticas cl��nicas de este trastorno, constituye una herramienta muy poderosa para el estudio de los mecanismos celulares y moleculares que subyacen a este s��ndrome, por lo tanto, en este proyecto nos proponemos obtener evidencias acerca de las alteraciones originadas a partir de efectos delet��reos de la exposici��n et��lica prenatal, que recapitulan el desarrollo de fenotipos conductuales y bioqu��micos descriptos en modelos para ADHD. Espec��ficamente nos proponemos determinar, por medio de experimentos conductuales, si la exposici��n a distintas dosis moderadas de alcohol durante un periodo acotado de la gestaci��n tard��a, son suficientes para generar alteraciones conductuales caracter��sticas de ADHD y establecer si metilfenidato y anfetamina, son capaces de revertirlas. Evaluar, mediante m��todos bioqu��micos, si este modelo involucra cambios en algunos de los componentes claves de la neurotransmisi��n dopamin��rgica, tales como niveles de dopamina y sus metabolitos, niveles de expresi��n de tirosina-hidroxilasa, de receptores y transportador de dopamina, del complejo cdk5/p35, entre otros. Esperamos recapitular caracter��sticas an��logas a las observadas en sujetos diagnosticados con ADHD y que el tratamiento con psicoestimulantes re-establezca los niveles de conducta normales. Mediante ensayos bioqu��micos, esperamos encontrar mayores niveles de dopamina en tejido estriatal, acompa��ados con un aumento en los niveles de sus metabolitos y mediante western blot y ensayos de actividad esperamos encontrar mayor nivel de expresi��n en D1, menor de DAT y alteraciones en la normal actividad y expresi��n de cdk5/p35, que podr��an explicar los resultados comportamentales esperados. Dada la alta prevalencia de ADHD y que estos j��venes pacientes son medicados con psicoestimulantes, junto con la poca informaci��n sobre las respuestas neuroadaptativas del cerebro inmaduro, es importante investigar los mecanismos que subyacen las alteraciones neurofisiol��gicas de este trastorno. Estos abordajes experimentales resultan centrales para el desarrollo de terapias mas eficientes para el tratamiento de este s��ndrome.

Combination Therapy for the Cardiovascular Effects of Perinatal Lead Exposure in Young and Adult Rats

Background: Combination therapy can play a significant role in the amelioration of several toxic effects of lead (Pb) and recovery from associated cardiovascular changes. Objective: To investigate the effects of combination therapy on the cardiovascular effects of perinatal lead exposure in young and adult rats Methods: Female Wistar rats received drinking water with or without 500 ppm of Pb during pregnancy and lactation. Twenty-two- and 70-day-old rat offspring who were or were not exposed to Pb in the perinatal period received meso-dimercaptosuccinic acid (DMSA), L-arginine, or enalapril and a combination of these compounds for 30 additional days. Noradrenaline response curves were plotted for intact and denuded aortas from 23-, 52-, 70-, and 100-day-old rats stratified by perinatal Pb exposure (exposed/unexposed) and treatment received (treated/untreated). Results: Systolic blood pressure was evaluated and shown to be higher in the 23-, 52-, 70-, and 100-day age groups with Pb exposure than in the corresponding control age groups: 117.8 &#177; 3.9*, 135.2 &#177; 1.3*, 139.6 &#177; 1.6*, and 131.7 &#177; 2.8*, respectively and 107.1 &#177; 1.8, 118.8 &#177; 2.1, 126.1 &#177; 1.1, and 120.5 &#177; 2.2, respectively (p < 0.05). Increased reactivity to noradrenaline was observed in intact, but not denuded, aortas from 52-, 70-, and 100-day-old exposed rats, and the maximum responses (g of tension) in the respective Pb-exposed and control age groups were as follows: 3.43 &#177; 0.16*, 4.32 &#177; 0.18*, and 4.21 &#177; 0.23*, respectively and 2.38 &#177; 0.33, 3.37 &#177; 0.13, and 3.22 &#177; 0.21, respectively (p < 0.05). Conclusions: All treatments reversed the changes in vascular reactivity to noradrenaline in rats perinatally exposed to Pb. The combination therapy resulted in an earlier restoration of blood pressure in Pb-exposed rats compared with the monotherapies, except for enalapril therapy in young rats. These findings represent a new approach to the development of therapeutic protocols for the treatment of Pb-induced hypertension.

The Benefits of Prone SPECT Myocardial Perfusion Imaging in Reducing Both Artifact Defects and Patient Radiation Exposure

AbstractBackground:Prone imaging has been demonstrated to minimize diaphragmatic and breast tissue attenuation.Objectives:To determine the role of prone imaging on the reduction of unnecessary rest perfusion studies and coronary angiographies performed, thus decreasing investigation time and radiation exposure.Methods:We examined 139 patients, 120 with an inferior wall and 19 with an anterior wall perfusion defect that might represented attenuation artifact. Post-stress images were acquired in both the supine and prone position. Coronary angiography was used as the &#8220;gold standard&#8221; for evaluating coronary artery patency. The study was terminated and rest imaging was obviated in the presence of complete improvement of the defect in the prone position. Quantitative interpretation was performed. Results were compared with clinical data and coronary angiographic findings.Results:Prone acquisition correctly revealed defect improvement in 89 patients (89/120) with inferior wall and 12 patients (12/19) with anterior wall attenuation artifact. Quantitative analysis demonstrated statistically significant difference in the mean summed stress scores (SSS) of supine and mean SSS of prone studies in patients with disappearing inferior wall defect in the prone position and patent right coronary artery (true negative results). The mean difference between SSS in supine and in prone position was higher with disappearing than with remaining defects.Conclusion:Technetium-99m (Tc-99m) tetrofosmin myocardial perfusion imaging with the patient in the prone position overcomes soft tissue attenuation; moreover it provides an inexpensive, accurate approach to limit the number of unnecessary rest perfusion studies and coronary angiographies performed.