Study of a cutaneous leishmaniasis outbreak in General Vedia, Province of Chaco, 1996

Between March and July 1996, a focalized epidemic outbreak of cutaneous leishmaniasis in General Vedia, province of Chaco, associated to the gallery forest of the Oro river was verified. The incidence rate in the area, which was 0-2/000 cases in preceding years, reached 8/000 cases in 1996. The risk of symptomatic infection was similar between sexes, but was different when analizing the different age groups by sex, suggesting a greater relative importance of the peridomestic transmission for the females and of the transmission in the subtropical forest for the males. Specimens of Lutzomyia intermedia, a species already incriminated as a vector of Leishmaniasis in other provinces of northern Argentina, were captured and identified in the focus locality in May 1996. The possible causes of the outbreak related to the climatic variables and the vector abundance are analyzed and the results in the framework of possible preventive and control activities are discussed.

Sistema para a monitoriza����o ativa com recurso ao cloud computing

O desenvolvimento de aplica����es para dispositivos m��veis j�� n��o �� uma ��rea recente, contudo continua a crescer a um ritmo veloz. �� not��rio o avan��o tecnol��gico dos ��ltimos anos e a crescente popularidade destes dispositivos. Este avan��o deve-se n��o s�� �� grande evolu����o no que diz respeito ��s caracter��sticas destes dispositivos, mas tamb��m �� possibilidade de criar aplica����es inovadoras, pr��ticas e pass��veis de solucionar os problemas dos utilizadores em geral. Nesse sentido, as necessidades do quotidiano obrigam �� implementa����o de solu����es que satisfa��am os utilizadores, e nos dias de hoje, essa satisfa����o muitas vezes passa pelos dispositivos m��veis, que j�� tem um papel fundamental na vida das pessoas. Atendendo ao aumento do n��mero de raptos de crian��as e �� inseguran��a que se verifica nos dias de hoje, as quais dificultam a tarefa de todos os pais/cuidadores que procuraram manter as suas crian��as a salvo, �� relevante criar uma nova ferramenta capaz de os auxiliar nesta ��rdua tarefa. A partir desta realidade, e com vista a cumprir os aspetos acima mencionados, surge assim esta disserta����o de mestrado. Esta aborda o estudo e implementa����o efetuados no sentido de desenvolver um sistema de monitoriza����o de crian��as. Assim, o objetivo deste projeto passa por desenvolver uma aplica����o nativa para Android e um back-end, utilizando um servidor de base de dados NoSQL para o armazenamento da informa����o, aplicando os conceitos estudados e as tecnologias existentes. A solu����o tem como principais premissas: ser o mais user-friendly poss��vel, a otimiza����o, a escalabilidade para outras situa����es (outros tipos de monitoriza����es) e a aplica����o das mais recentes tecnologias. Assim sendo, um dos estudos mais aprofundados nesta disserta����o de mestrado est�� relacionado com as bases de dados NoSQL, dada a sua import��ncia no projeto.

Nonreductive physicalism and mental causation

In this work I articulate...

Development of paper-based color test-strip for drug detection in aquatic environment: Application to oxytetracycline

The wide use of antibiotics in aquaculture has led to the emergence of resistant microbial species. It should be avoided/minimized by controlling the amount of drug employed in fish farming. For this purpose, the present work proposes test-strip papers aiming at the detection/semi-quantitative determination of organic drugs by visual comparison of color changes, in a similar analytical procedure to that of pH monitoring by universal pH paper. This is done by establishing suitable chemical changes upon cellulose, attributing the paper the ability to react with the organic drug and to produce a color change. Quantitative data is also enabled by taking a picture and applying a suitable mathematical treatment to the color coordinates given by the HSL system used by windows. As proof of concept, this approach was applied to oxytetracycline (OXY), one of the antibiotics frequently used in aquaculture. A bottom-up modification of paper was established, starting by the reaction of the glucose moieties on the paper with 3-triethoxysilylpropylamine (APTES). The so-formed amine layer allowed binding to a metal ion by coordination chemistry, while the metal ion reacted after with the drug to produce a colored compound. The most suitable metals to carry out such modification were selected by bulk studies, and the several stages of the paper modification were optimized to produce an intense color change against the concentration of the drug. The paper strips were applied to the analysis of spiked environmental water, allowing a quantitative determination for OXY concentrations as low as 30 ng/mL. In general, this work provided a simple, method to screen and discriminate tetracycline drugs, in aquaculture, being a promising tool for local, quick and cheap monitoring of drugs.

Seroprevalence of antibodies to Venezuelan equine encephalitis complex (subtypes IAB and VI) in humans from General Belgrano Island, Formosa, Argentina

This work presents the results of the detection of antibodies (immunoglobulin G) for subtypes I and VI of VEE viruses complex (Togaviridae family) in people from the General Belgrano island, Formosa province (Argentina). The prevalence of neutralizing (NT) antibodies for subtype VI was from 30% to 70% and the prevalence of antibodies inhibitory of hemagglutination (HI) was of 0% in the first and second inquiry respectively. For the subtype IAB the prevalence of NT antibodies was from 13% to 3.6%, similar to the prevalence total for both subtypes. HI antibodies were not detected in any inquiries for any subtype. It was observed that both subtypes circulate simultaneously, while subtype VI remains constant with some peaks, subtype I was found in low level.

Solid contact PVC membrane electrodes based on neutral or charged carriers for the selective reading of anionic sulfamethoxazole and their application to the analysis of aquaculture water

Sulfamethoxazole (SMX) is among the antibiotics employed in aquaculture for prophylactic and therapeutic reasons. Environmental and food spread may be prevented by controlling its levels in several stages of fish farming. The present work proposes for this purpose new SMX selective electrodes for the potentiometric determination of this sulphonamide in water. The selective membranes were made of polyvinyl chloride (PVC) with tetraphenylporphyrin manganese (III) chloride or cyclodextrin-based acting as ionophores. 2-nitrophenyl octyl ether was employed as plasticizer and tetraoctylammonium, dimethyldioctadecylammonium bromide or potassium tetrakis (4-chlorophenyl) borate was used as anionic or cationic additive. The best analytical performance was reported for ISEs of tetraphenylporphyrin manganese (III) chloride with 50% mol of potassium tetrakis (4-chlorophenyl) borate compared to ionophore. Nersntian behaviour was observed from 4.0��������10���5 to 1.0��������10���2���mol/L (10.0 to 2500�����g/mL), and the limit of detection was 1.2��������10���5���mol/L (3.0�����g/mL). In general, the electrodes displayed steady potentials in the pH range of 6 to 9. Emf equilibrium was reached before 15���s in all concentration levels. The electrodes revealed good discriminating ability in environmental samples. The analytical application to contaminated waters showed recoveries from 96 to 106%.

Sulfadiazine-selective determination in aquaculture environment: Selective potentiometric transduction by neutral or charged ionophores

Solid-contact sensors for the selective screening of sulfadiazine (SDZ) in aquaculture waters are reported. Sensor surfaces were made from PVC membranes doped with tetraphenylporphyrin-manganese(III) chloride, ��-cyclodextrin, ��-cyclodextrin, or ��-cyclodextrin ionophores that were dispersed in plasticizer. Some membranes also presented a positive or a negatively charged additive. Phorphyrin-based sensors relied on a charged carrier mechanism. They exhibited a near-Nernstian response with slopes of 52 mV decade���1 and detection limits of 3.91 �� 10���5 mol L���1. The addition of cationic lipophilic compounds to the membrane originated Nernstian behaviours, with slopes ranging 59.7���62.0 mV decade���1 and wider linear ranges. Cyclodextrin-based sensors acted as neutral carriers. In general, sensors with positively charged additives showed an improved potentiometric performance when compared to those without additive. Some SDZ selective membranes displayed higher slopes and extended linear concentration ranges with an increasing amount of additive (always <100% ionophore). The sensors were independent from the pH of test solutions within 2���7. The sensors displayed fast response, always <15 s. In general, a good discriminating ability was found in real sample environment. The sensors were successfully applied to the fast screening of SDZ in real waters samples from aquaculture fish farms. The method offered the advantages of simplicity, accuracy, and automation feasibility. The sensing membrane may contribute to the development of small devices allowing in locus measurements of sulfadiazine or parent-drugs.

M��scaras da (in)capacidade: projeto desenvolvido numa institui����o de apoio a pessoas com defici��ncia intelectual

Neste relat��rio apresenta-se o projeto de Educa����o e Interven����o Social intitulado ���M��scaras da (In)Capacidade���, que assentou na metodologia de Investiga����o-A����o Participativa. Caracterizando-se pela an��lise dos contextos, pela a����o, pela reflex��o profunda e cont��nua, e pela avalia����o, sempre numa perspetiva de participa����o, esta metodologia possibilita ao investigador social conhecer e envolver-se na realidade de uma maneira muito mais efetiva. O presente trabalho constitui, assim, um olhar retrospetivo sobre o trabalho desenvolvido num contexto institucional de acolhimento de pessoas com defici��ncia intelectual. O projeto desenvolvido teve como principal finalidade: ���Melhorar as din��micas relacionais e de funcionamento existentes na institui����o, de forma a proporcionar um maior bem-estar f��sico e psicol��gico das pessoas que trabalham, vivem e/ou frequentam a institui����o���. Neste sentido, promovendo sempre a participa����o efetiva de pessoas com incapacidade e seus cuidadores, procedeu-se �� utiliza����o de t��cnicas que permitiram conhecer, analisar e trabalhar no contexto, tendo em vista a concretiza����o dos objetivos gerais do projeto. Esses objetivos, de uma forma sin��ptica, tinham como inten����o promover uma melhor intera����o entre todas as pessoas do CAO, e melhorar o funcionamento do Centro de Atividades Ocupacionais (CAO) da Institui����o. Assim, procurando sempre uma mudan��a constru��da e refletida por todos, num processo de avalia����o cont��nua, �� poss��vel afirmar que existiu uma melhoria tanto a n��vel das din��micas relacionais, como ao n��vel de alguns aspetos relacionados com o funcionamento da val��ncia

Nonlinear dynamics of the patient���s response to drug effect during general anesthesia

In today���s healthcare paradigm, optimal sedation during anesthesia plays an important role both in patient welfare and in the socio-economic context. For the closed-loop control of general anesthesia, two drugs have proven to have stable, rapid onset times: propofol and remifentanil. These drugs are related to their effect in the bispectral index, a measure of EEG signal. In this paper wavelet time���frequency analysis is used to extract useful information from the clinical signals, since they are time-varying and mark important changes in patient���s response to drug dose. Model based predictive control algorithms are employed to regulate the depth of sedation by manipulating these two drugs. The results of identification from real data and the simulation of the closed loop control performance suggest that the proposed approach can bring an improvement of 9% in overall robustness and may be suitable for clinical practice.

Preval��ncia de obesidade infanto-juvenil : associa����o com os h��bitos alimentares, actividade f��sica e comportamentos sedent��rios dos adolescentes escolarizados de Portugal Conti

RESUMO Nos pa��ses industrializados observam-se elevadas preval��ncias de pr��- obesidade e obesidade em jovens e adolescentes, com consequ��ncias negativas para a sa��de. A obesidade �� apontada como o dist��rbio nutricional mais frequente em crian��as e adolescentes nos pa��ses desenvolvidos e �� resultado da acumula����o excessiva ou anormal de gordura no tecido adiposo. Segundo a I.O.T.F. considera- se que uma crian��a tem pr��-obesidade quando o seu percentil de I.M.C. est�� entre o p88 e p99 para as raparigas e entre o p90 e o p99 para os rapazes. Considerase que tem obesidade quando o percentil de I.M.C. �� superior ao p99, para ambos os sexos. A preval��ncia de pr��-obesidade e obesidade em crian��as e adolescentes tem vindo a aumentar a n��vel mundial a um ritmo alarmante, sobretudo nos pa��ses desenvolvidos e em alguns segmentos de pa��ses em desenvolvimento. Estudos demonstram que a obesidade em crian��as e adolescentes se encontra fortemente correlacionada com o aumento da morbilidade e mortalidade, reflectindo-se numa variedade de situa����es patol��gicas com risco de persist��ncia no adulto. Dada a sua extrema import��ncia em termos de Sa��de P��blica, as tend��ncias para a pr��- obesidade e obesidade em crian��as e adolescentes devem ser monitorizadas com especial aten����o. Os h��bitos alimentares e o gasto energ��tico s��o factores que influenciam a obesidade e o seu controlo. H�� estudos que concluem que existe uma associa����o directa entre estes factos e a presen��a de obesidade e outros apresentam conclus��es contr��rias. Pretendeu-se determinar a preval��ncia de excesso de peso (pr��-obesidade e obesidade) infantojuvenil em Portugal e associ��-la com os h��bitos alimentares, actividade f��sica e comportamentos sedent��rios dos adolescentes. A popula����o em estudo �� todos os adolescentes, de ambos os sexos, que frequentam o ensino b��sico (2�� e 3�� ciclos) e secund��rio oficial de Portugal Continental (n=5708). Todos os elementos em estudos foram avaliados antropometricamente (peso e altura) e responderam a um question��rio de h��bitos alimentares e frequ��ncia alimentar, actividade f��sica e comportamentos sedent��rios. Como resultados do estudo verificou-se que a preval��ncia de pr��- obesidade infanto-juvenil em Portugal �� de 22,6% e a preval��ncia de obesidade de 7,8%. Quer a obesidade quer a pr��-obesidade apresentam indicadores superiores nos rapazes (p=0,01) e nos adolescentes mais jovens (p=0,00). Em rela����o aos h��bitos alimentares estudados �� de referir que a frequ��ncia de consumo de refei����es fora de casa �� muito similar entre o grupo normoponderal e o grupo com excesso de peso sendo a refei����o da ceia consumida por um n��mero muito superior de adolescentes normoponderais comparativamente com os que apresentam excesso de peso (p=0,01). Em rela����o �� ingest��o de determinados alimentos ou grupos aliment��cios, verificou-se que, regra geral, o consumo de alimentos de caracter��sticas nutricionais de baixa qualidade (gordura saturada, sal e a��ucares simples) era superior no grupo normoponderal comparativamente ao grupo com excesso de peso (refrigerantes, snacks, fast-food, cereais a��ucarados, sobremesas doces) (p<0,05). Em rela����o �� actividade f��sica, o n��mero de horas semanais de actividade f��sica diminui do grupo normoponderal para o grupo com excesso de peso. Dentro do grupo com excesso de peso, os obesos apresentam ainda uma m��dia inferior em rela����o aos pr��-obesos. Poderemos afirmar que quanto maior o ��ndice de actividade f��sica menor o percentil de I.M.C., mostrando-se assim a actividade f��sica como um factor protector de um peso saud��vel (p<0,05). Quando solicitado que caracterizassem o estilo de vida e a habilidade desportiva, verificou-se que nos grupos com excesso de peso se caracterizavam em indicadores mais baixos do que os normoponderais (p<0,05). No que diz respeito aos comportamentos sedent��rios, verifica-se que s��o mais prevalentes nos grupos com excesso de peso do que no grupo normoponderal (p<0,05). Em conclus��o, os resultados da preval��ncia de obesidade obtidos assemelham-se aos resultados obtidos noutros estudos, constituindo um dado revelador de uma situa����o bastante preocupante em termos de Sa��de P��blica. Em rela����o aos h��bitos alimentares as diferen��as n��o s��o significativas entre os diferentes grupos (normoponderal, pr��-obesidade e obesidade). A actividade f��sica apresentou-se como um factor protector do aumento de peso com uma associa����o directa com o estado nutricional (I.M.C.). Verificou-se que os adolescentes em Portugal que apresentavam indicadores mais elevados de actividade f��sica eram aqueles que se encontravam com peso normal. Os comportamentos sedent��rios apresentaram-se como um factor prop��cio ao desenvolvimento do excesso de peso estando directamente relacionados com o percentil de I.M.C. Os comportamentos sedent��rios mais frequentes s��o o visionamento televisivo e o computador/internet. Assim, poder-se-�� fundamentar a necessidade de medidas interventivas a este n��vel com o intuito de controlar os indicadores encontrados. ABSTRACT In the industrialized countries high prevalences of pre-obesity and obesity are observed in youngsters and adolescents, with negative health consequences. Obesity is pointed as the most frequent nutritional disturbance in children and adolescents in developed countries and results from the excessive or abnormal accumulation of fat in the adipose tissue. According to the IOTF a child is pre-obese when the BMI percentile is between p88 and p99 for girls and between p90 and p99 for boys. Obesity is considered when the BMI percentile is above p99 for both sexes. The prevalence of pre-obesity and obesity in children and adolescents has been rising alarmingly worldwide, especially in developed countries and some segments of developing countries. Studies indicate that obesity in children and adolescents is strongly associated with increased morbidity and mortality resulting in a variety of pathological situations with risk of persistence in adulthood. Given its major Public Health importance, pre-obesity and obesity trends in children and adolescents should be monitored with special attention. Eating habits and energy expenditure are factors that influence obesity and its control. Some studies conclude that there is a direct association between these factors and the presence of obesity and others present opposite conclusions. It was intended to determine the prevalence of overweight (pre-obesity and obesity) in children and youth in Portugal and to associate it with eating habits, physical activity and sedentary behaviors of adolescents. The population in study is constituted by all adolescents of both sexes that attend basic (2nd and 3rd grade) and secondary official education of continental Portugal (n=5708). All participants in study were anthropometrically evaluated (weight and height) and answered a questionnaire of eating habits and food frequency, physical activity and sedentary behaviors. The study results indicate a prevalence of pre-obesity in children and youth in Portugal of 22.6% and a prevalence of obesity of 7.8%. Both obesity and pre-obesity present higher indicators in boys (p=0.01) and younger adolescents (p=0.00). In relation to the studied eating habits it should be noted that the frequency of consumption of meals away from home is very similar between the normal weight group and the overweight group. Moreover, the supper meal is consumed by a much larger number of normal weight adolescents as compared to the ones with overweight (p=0.01). Regarding the intake of certain foods or food groups, it was found that, in general, the consumption of foods with characteristics of low nutritional quality (saturated fat, salt and simple sugars) was higher in the normoponderal group compared with the overweight group (soft drinks, snacks, fast-food, sugary cereals, desserts) (p<0.05). In respect to physical activity, the number of weekly hours of physical activity decreases from the normoponderal group to the group with overweight. Within the group with overweight, obese subjects also present a lower average than pre-obese subjects. As we can affirm that the higher the physical activity index the lower the BMI percentile, physical activity appears as a protective factor for a healthy weight (p<0.05). When they were asked to characterize their lifestyle and sports ability, it was found that overweight groups characterized themselves with lower indicators than the normoponderal group (p<0.05). Regarding sedentary behaviors, it appears that they were more prevalent in groups with overweight than in the normoponderal group (p<0.05). In conclusion, the results of the obesity prevalence attained are similar to the results obtained in other studies, revealing a very worrying situation in terms of Public Health. In relation to the eating habits there were no significant differences between the groups (normoponderal, pre-obesity and obesity). Physical activity appears as a protective factor from weight gain with a direct association with nutritional status (BMI). It was found that young people in Portugal who had the highest indicators of physical activity were those who presented normal weight. The sedentary behaviors were presented as a factor conducive to the development of overweight being directly related to the BMI percentile. The most frequent sedentary behaviors were television viewing and computer/internet

Literacia em sa��de e alimenta����o saud��vel : os novos produtos e a escolha dos alime

Resumo Com o objectivo de contribuir para entender o n��vel de literacia em sa��de dos consumidores e verificar a rela����o entre esta e o comportamento no consumo de alimentos (consumerismo), foi efectuado um inqu��rito por question��rio que incluiu a tradu����o para Portugu��s do Newest Vital Sign,�� (2008) Pfizer Inc. Used with permission (NVS). Este instrumento foi aplicado a uma amostra estratificada, de 384 indiv��duos com mais de 15 anos de idade, da regi��o da Grande Lisboa, distribu��da de acordo com o Census 2001. A n��vel de literacia em sa��de foi avaliado atrav��s da vers��o Portuguesa do NVS que consiste numa ���ferramenta��� onde se fornece aos inquiridos uma s��rie de informa����es relacionadas com a sa��de, nomeadamente a informa����o nutricional constante de um r��tulo, devendo estes fazer a demonstra����o das suas capacidades de utiliza����o dessa informa����o respondendo a quest��es. Dos resultados recolhidos verifica-se que existe uma rela����o directa entre a literacia em sa��de e a escolaridade, constatou-se ainda uma associa����o entre a literacia em sa��de e o comportamento consumerista no consumo de alimentos assim como com um comportamento de consumo pautado pela consci��ncia ecol��gica. De salientar ainda a rela����o estatisticamente significativa entre a literacia em sa��de e a neofilia alimentar. No entanto os indiv��duos mais idosos, com menores habilita����es liter��rias e de menor rendimento s��o mais neof��bicos N��o existe rela����o entre o g��nero e a literacia em sa��de. O NVS, agora dispon��vel na l��ngua portuguesa, constitui num contexto de promo����o da sa��de, uma ajuda em termos de Sa��de P��blica. Abstract Aiming to contribute to the understanding of consumer���s health literacy, and to verify the relation between health literacy and consumerism in food consumption, a validation of an inquiry, that include the Portuguese version of the Newest Vital Sign, �� (2008) Pfizer Inc. Used with permission (NVS) was performed. Afterwards this epidemiologic instrument was applied to a convenience sample (384 individuals, over 15 years old) of the population of ���Grande Lisboa���, distributed accordingly to Census 2001. Health literacy was evaluated by the Portuguese version of NVS and consists in a tool by which a number of health-related information, in this case nutritional information written in a food label, is used to demonstrate one���s ability to use that information answering to questions. From the results it is possible to verify that there is a close relation between health literacy and general literacy (school years), it was also possible to observe an association among health literacy, consumer behaviour and ecological consumption of food products. It is of relevance the fact that an association between health literacy and food neophilia is statistically significant. Nevertheless older individuals, with lower health literacy and income are the most neophobic. There is no statistical association between gender and health literacy. The Portuguese version of NVS is an essential tool to evaluate the population health literacy in a hea

Ball Sensing in a Leg Like Robotic Kicker

The trend to have more cooperative play and the increase of game dynamics in Robocup MSL League motivates the improvement of skills for ball passing and reception. Currently the majority of the MSL teams uses ball handling devices with rollers to have more precise kicks but limiting the capability to kick a moving ball without stopping it and grabbing it. This paper addresses the problem to receive and kick a fast moving ball without having to grab it with a roller based ball handling device. Here, the main difficulty is the high latency and low rate of the measurements of the ball sensing systems, based in vision or laser scanner sensors.Our robots use a geared leg coupled to a motor that acts simultaneously as the kicking device and low level ball sensor. This paper proposes a new method to improve the capability for ball sensing in the kicker, by combining high rate measurements from the torque and energy in the motor and angular position of the kicker leg. The developed method endows the kicker device with an effective ball detection ability, validated in several game situations like in an interception to a fast pass or when chasing the ball where the relative speed from robot to ball is low. This can be used to optimize the kick instant or by the embedded kicker control system to absorb the ball energy.

Combining sparse and dense methods in 6D Visual Odometry

13th International Conference on Autonomous Robot Systems (Robotica), 2013, Lisboa

Development and validation of a risk model for prediction of hazardous alcohol consumption in general practice attendees : the PredictAL study

Background: Little is known about the risk of progression to hazardous alcohol use in people currently drinking at safe limits. We aimed to develop a prediction model (predictAL) for the development of hazardous drinking in safe drinkers. Methods: A prospective cohort study of adult general practice attendees in six European countries and Chile followed up over 6 months. We recruited 10,045 attendees between April 2003 to February 2005. 6193 European and 2462 Chilean attendees recorded AUDIT scores below 8 in men and 5 in women at recruitment and were used in modelling risk. 38 risk factors were measured to construct a risk model for the development of hazardous drinking using stepwise logistic regression. The model was corrected for over fitting and tested in an external population. The main outcome was hazardous drinking defined by an AUDIT score >= 8 in men and >= 5 in women. Results: 69.0% of attendees were recruited, of whom 89.5% participated again after six months. The risk factors in the final predictAL model were sex, age, country, baseline AUDIT score, panic syndrome and lifetime alcohol problem. The predictAL model's average c-index across all six European countries was 0.839 (95% CI 0.805, 0.873). The Hedge's g effect size for the difference in log odds of predicted probability between safe drinkers in Europe who subsequently developed hazardous alcohol use and those who did not was 1.38 (95% CI 1.25, 1.51). External validation of the algorithm in Chilean safe drinkers resulted in a c-index of 0.781 (95% CI 0.717, 0.846) and Hedge's g of 0.68 (95% CI 0.57, 0.78). Conclusions: The predictAL risk model for development of hazardous consumption in safe drinkers compares favourably with risk algorithms for disorders in other medical settings and can be a useful first step in prevention of alcohol misuse.

Effects of Environmental Organochlorine Pesticides on Human Breast Cancer: Putative Involvement on Invasive Cell Ability

Human exposure to persistent organic pollutants (POPs) is a certainty, even to long banned pesticides like o,p���-dichlorodiphenyltrichloroethane (o,p���-DDT), and its metabolites p,p���-dichlorodiphenyldichloroethylene (p,p���-DDE), and p,p���-dichlorodiphenyldichloroethane (p,p���-DDD). POPs are known to be particularly toxic and have been associated with endocrine-disrupting effects in several mammals, including humans even at very low doses. As environmental estrogens, they could play a critical role in carcinogenesis, such as in breast cancer. With the purpose of evaluating their effect on breast cancer biology, o,p���-DDT, p,p���-DDE, and p,p���-DDD (50���1000 nM) were tested on two human breast adenocarcinoma cell lines: MCF-7 expressing estrogen receptor (ER) �� and MDA-MB-231 negative for ER��, regarding cell proliferation and viability in addition to their invasive potential. Cell proliferation and viability were not equally affected by these compounds. In MCF-7 cells, the compounds were able to decrease cell proliferation and viability. On the other hand, no evident response was observed in treated MDA-MB-231 cells. Concerning the invasive potential, the less invasive cell line, MCF-7, had its invasion potential significantly induced, while the more invasive cell line MDA-MB-231, had its invasion potential dramatically reduced in the presence of the tested compounds. Altogether, the results showed that these compounds were able to modulate several cancer-related processes, namely in breast cancer cell lines, and underline the relevance of POP exposure to the risk of cancer development and progression, unraveling distinct pathways of action of these compounds on tumor cell biology.