Practical Quality Control: Comparision of Methods on the Quantification of Stationary Phases in Paper and Thin-Layer Chromatographic Systems

Introduction: Paper and thin layer chromatography methods are frequently used in Classic Nuclear Medicine for the determination of radiochemical purity (RCP) on radiopharmaceutical preparations. An aliquot of the radiopharmaceutical to be tested is spotted at the origin of a chromatographic strip (stationary phase), which in turn is placed in a chromatographic chamber in order to separate and quantify radiochemical species present in the radiopharmaceutical preparation. There are several methods for the RCP measurement, based on the use of equipment as dose calibrators, well scintillation counters, radiochromatografic scanners and gamma cameras. The purpose of this study was to compare these quantification methods for the determination of RCP. Material and Methods: 99mTc-Tetrofosmin and 99mTc-HDP are the radiopharmaceuticals chosen to serve as the basis for this study. For the determination of RCP of 99mTc-Tetrofosmin we used ITLC-SG (2.5 x 10 cm) and 2-butanone (99mTc-tetrofosmin Rf = 0.55, 99mTcO4- Rf = 1.0, other labeled impurities 99mTc-RH RF = 0.0). For the determination of RCP of 99mTc-HDP, Whatman 31ET and acetone was used (99mTc-HDP Rf = 0.0, 99mTcO4- Rf = 1.0, other labeled impurities RF = 0.0). After the development of the solvent front, the strips were allowed to dry and then imaged on the gamma camera (256x256 matrix; zoom 2; LEHR parallel-hole collimator; 5-minute image) and on the radiochromatogram scanner. Then, strips were cut in Rf 0.8 in the case of 99mTc-tetrofosmin and Rf 0.5 in the case of 99mTc-HDP. The resultant pieces were smashed in an assay tube (to minimize the effect of counting geometry) and counted in the dose calibrator and in the well scintillation counter (during 1 minute). The RCP was calculated using the formula: % 99mTc-Complex = [(99mTc-Complex) / (Total amount of 99mTc-labeled species)] x 100. Statistical analysis was done using the test of hypotheses for the difference between means in independent samples. Results:The gamma camera based method demonstrated higher operator-dependency (especially concerning the drawing of the ROIs) and the measures obtained using the dose calibrator are very sensitive to the amount of activity spotted in the chromatographic strip, so the use of a minimum of 3.7 MBq activity is essential to minimize quantification errors. Radiochromatographic scanner and well scintillation counter showed concordant results and demonstrated the higher level of precision. Conclusions: Radiochromatographic scanners and well scintillation counters based methods demonstrate to be the most accurate and less operator-dependant methods.

Use of negative information in positioning and tracking algorithms

To avoid additional hardware deployment, indoor localization systems have to be designed in such a way that they rely on existing infrastructure only. Besides the processing of measurements between nodes, localization procedure can include the information of all available environment information. In order to enhance the performance of Wi-Fi based localization systems, the innovative solution presented in this paper considers also the negative information. An indoor tracking method inspired by Kalman filtering is also proposed.

Studies on prevalence of Strongyloides infection in Holambra and Maceió, Brazil, by the agar plate faecal culture method

Prevalence of Strongyloides stercoralis infection in three areas of Brazil was surveyed by a recently developed faecal culture method (an agar plate culture). The Strongyloides infection was confirmed in 11.3% of 432 subjects examined. The diagnostic efficacy of the agar plate culture was as high as 93.9% compared to only 28.5% and 26.5% by the Harada-Mori filter paper culture and faecal concentration methods, when faecal samples were examined simultaneously by these three methods. Among the 49 positive samples, about 60% were confirmed to be positive only by the agar plate culture. These results indicate that the agar plate culture is a sensitive new tool for the correct diagnosis of chronic Strongyloides infection.

Distribution of virulence markers in clinical and environmental Vibrio cholerae non-O1/non-O139 strains isolated in Brazil from 1991 to 2000

One hundred seventy nine Vibrio cholerae non-O1/non-O139 strains from clinical and different environmental sources isolated in Brazil from 1991 to 2000 were serogrouped and screened for the presence of four different virulence factors. The Random Amplification of Polymorphic DNA (RAPD) technique was used to evaluate the genetic relatedness among strains. Fifty-four different serogroups were identified and V. cholerae O26 was the most common (7.8%). PCR analysis for three genes (ctxA, zot, ace) located of the CTX genetic element and one gene (tcpA) located on the VPI pathogenicity island showed that 27 strains harbored one or more of these genes. Eight (4.5%) strains possessed the complete set of CTX element genes and all but one of these belonged to the O26 serogroup suggesting that V. cholerae O26 has the potential to be an epidemic strain. The RAPD profiles revealed a wide variability among strains and no genetic correlation was observed.

Epidemiological investigation of an acute case of Chagas disease in an area of active transmission in Peruvian Amazon region

The study objective was to investigate an acute case of Chagas disease in the San Pedro de Shishita community, Pebas District, in the Peruvian Amazon basin, a non-endemic area. Both parents of the index case (acute case) were thoroughly interviewed, a seroepidemiological survey was carried out in the community, parasitological exams were carried out only in relatives of the index case, and triatomine bugs were searched for inside houses, peridomiciliary, and in wild environments. Seroprevalence for IgG anti-T. cruzi antibodies was 1/104 (0.96%), using an ELISA test and an indirect immunofluorescence assay. Panstrongylus geniculatus and Rhodnius pictipes adults were found. The index case is autochthonous from San Pedro de Shishita, but the source of transmission is unknown.

Case-control study of an outbreak of acute toxoplasmosis in an industrial plant in the state of São Paulo, Brazil

Foodborne diseases represent operational risks in industrial restaurants. We described an outbreak of nine clustered cases of acute illness resembling acute toxoplasmosis in an industrial plant with 2300 employees. These patients and another 36 similar asymptomatic employees were diagnosed with anti-T. gondii IgG titer and avidity by ELISA. We excluded 14 patients based on high IgG avidity and chronic toxoplasmosis: 13 from controls and one from acute disease other than T. gondii infection. We also identified another three asymptomatic employees with T.gondii acute infection and also anti-T. gondii IgM positive as remaining acute cases. Case control study was conducted by interview in 11 acute infections and 20 negative controls. The ingestion of green vegetables, but not meat or water, was observed to be associated with the incidence of acute disease. These data reinforce the importance of sanitation control in industrial restaurants and also demonstrate the need for improvement in quality control regarding vegetables at risk for T. gondii oocyst contamination. We emphasized the accurate diagnosis of indexed cases and the detection of asymptomatic infections to determine the extent of the toxoplasmosis outbreak.

PHLEBOTOMINE FAUNA (DIPTERA: PSYCHODIDAE) IN AN AREA OF FISHING TOURISM IN CENTRAL-WESTERN BRAZIL

The aim of this study was to identify behavioral aspects of the sandfly fauna of a fishing tourism area in the municipality of Bonito (MS). Monthly captures were undertaken from December 2009 to November 2010, using automatic CDC type light traps, from 18h00 to 06h00, in a forested area, a savannah area, peridomiciles and animal shelters near peridomiciliary areas. Nyssomyia whitmani was the most frequent out of a total of 6,699 specimens collected, belonging to 16 species, followed by Psathyromyia bigeniculata and Lutzomyia longipalpis, found in all the environments investigated, though in their greatest numbers in the animal shelters. Ny. whitmani exhibited its highest frequencies during the dry months, coincident with the fishing season, when the risk of transmission of cutaneous leishmaniasis for tourists and inhabitants increases. Noteworthy was the finding of two species naturally infected by flagellates: Ny. whitmani and Pa. bigeniculata. The local population and visiting tourists should be warned of the threat posed by leishmaniasis and the health authorities alerted to the need for adopting environmental sanitary measures, especially regarding such animal shelters as they seem to provide favorable conditions to the proliferation, maintenance and breeding opportunities of phlebotomines.

The palm tree Copernicia cerifera (carnaúba) as an ecotope of Rhodnius nasutus in rural areas of the State of Piauí Northeastern Brazil

The C. cerifera palm tree (carnaúba) is widely distributed in the Northeastem Brazil, including the State of Piauí. This investigation revealed that R. nasutus is the ortly triatomine species captured on that palm tree, in five different localities. 78% of palm trees were infested with triatomines, and 4.0% were infected with flagellates morphologically and biologically indistinguishable from Trypanosoma cruzi. Birds, rodents and marsupials were found as major blood meai sources for R. nasutus.

Role of biotic interactions in generating and maintaining biodiversity

Dissertation presented to obtain the Ph.D degree in Biology.

Report of a traineeship : audit of antidepressant prescribing in Primary and Mental Care: how to address appropriateness and keep a curb on costs. A tool suitable for all contexts?

RESUMO: Este é o relatório de um estágio realizado na Autoridade de Saúde Local de Bolonha com o objectivo de desenvolver capacidades e competências na área de projectos orientados para a avaliação com base epidemiológica. As prescrições de anti-depressivos aumentaram consideravelmente em todo o mundo durante as últimas décadas. O uso cada vez maior dos agentes mais dispendiosos desempenha um papel na subida do custo dos tratamentos. A Autoridade de Saúde Local de Bolonha implementou um processo de auditoria com o objectivo de melhorar a adequação das prescrições de pacientes externos, centrando-se em dois anti-depressivos de marca ainda protegidos por patente, Escitalopram e Duloxetine. Os Departamentos de Cuidados de Saúde Primários e de Cuidados de Saúde Mental, assim como o Departamento Farmacêutico e a Unidade de Gestão Clínica, estiveram envolvidos na fase de planeamento da auditoria. O grupo da auditoria, maioritariamente composto por médicos de clínica geral e psiquiatras, reuniu e analisou provas da eficácia e segurança dos anti-depressivos. Os dados sobre as prescrições das Unidades de Cuidados de Saúde Primários e dos Centros de Saúde Mental Comunitários da Autoridade de Saúde Local (866.294 habitantes) foram comparados, em particular as taxas de consumo de Escitalopram e Duloxetine. O grupo da auditoria definiu os standards a serem abordados, os indicadores a serem avaliados e as medidas a empreender para atingir os objectivos definidos. As directrizes do NICE sobre a depressão foram escolhidas como referência. O objectivo da auditoria foi definido como evitar o Escitalopram e Duloxetine como medicamentos de primeira escolha num tratamento anti-depressivo. De modo a verificar a eficácia das medidas empreendidas foi seleccionado um indicador, consistindo numa redução de 25% das prescrições de ambos os anti-depressivos na prática clínica de pacientes externos e numa redução de 20% da variabilidade nas Unidades de Cuidados de Saúde Primários. O relatório retrospectivo pré-auditoria (Janeiro a Abril de 2012) revelou que os tratamentos com anti-depressivos para pacientes externos eram prescritos pelos médicos de clínica geral em mais de90% dos casos. As medidas da auditoria foram implementadas entre Novembro de 2012 e Maio de 2013. Algumas medidas relevantes foram integradas com a revisão da auditoria, tais como reuniões educacionais de pequena escala com os médicos de clínica geral e psiquiatras, visitas de apoio do assessor de prescrições da Autoridade de Saúde Local aos médicos de clínica geral e Centros de Saúde Mental Comunitários, panfletos para profissionais com informação retirada das directrizes clínicas do NICE, implementação de um serviço de consulta na Web para médicos de clínica geral sobre provas relativas a anti-depressivos. O relatório de feedback é aguardado em Novembro de 2013 depois de se verificar nos standards atingidos a eficácia das medidas implementadas. Foi realizada uma análise SWOT para comprovar as forças e fraquezas, as oportunidades e ameaças do processo. Como identificação de fraquezas poderá ser útil identificar estratégias relevantes para melhoria interna, para que o conhecimento das ameaças possa amortizar factores que possam ter impactos adversos que fujam ao controlo do Departamento de Saúde Mental. Uma melhor compreensão das forças e das oportunidades facilita a consecução dos objectivos estabelecidos no projecto. O primeiro, mas não o último, resultado deste processo consistiu numa maior integração entre os Cuidados de Saúde Primários e de Saúde Mental, permitindo assim que a Autoridade de Saúde Local coloque as alterações em prática.------------ABSTRACT: This is the report of a traineeship held in the Local Health Authority of Bologna with the aim to develop skills and competencies in the field of epidemiogically based evaluation oriented projects. Antidepressants prescriptions have considerably increased all over the world in the last decades. The increasing use of the most expensive agents plays a part in the rising cost of treatments. The Local Health Authority of Bologna has implemented an audit process aimed at improving the appropriateness of outpatient prescriptions focusing on the two branded antidepressants still protected by patent, Escitalopram and Duloxetine. The Primary Care and the Mental Health Care Departments, as well as the Pharmaceutical Department and the Clinical Governance Unit, were involved in the planning phase of the audit. The audit group, mainly composed of general practitioners and psychiatrists, collected and analyzed scientific evidence on effectiveness and safety of antidepressants. Data on prescriptions of Primary Care Units and Community Mental Health Centers of the Local Health Authority (866.294 inhabitants) were compared, in particular consumption rates of Escitalopram and Duloxetine. The audit group defined the standards to be addressed, the indicators to be evaluated and the actions aimed at reaching the defined goals. NICE guidelines on depression were chosen as reference. The aim of the audit was settled as avoiding Escitalopram and Duloxetine as first choice drugs starting an AD treatment. In order to check the efficacy of the actions undertaken an indicator was selected, consisting in a reduction of 25% of prescriptions of both ADs in outpatient practice and in a 20% reduction of To develop skills and competencies across Primary Care Units. The pre-audit retrospective report (January-April 2012) showed that outpatient antidepressant treatments were prescribed by GPs in over 90% of cases. Audit actions were implemented between November 2012 and May 2013. Some relevant actions have been integrated with the audit review, such as small-scale educational meetings with GPs and psychiatrists, outreach visits of the LHA prescribing adviser to GPs and CMHCs,leaflets for professionals with information extracted from NICE clinical guidelines, implementation of a web consultation service for GPs about evidence on antidepressants. The feedback report is expected in November 2013 after checking through the standards attained the effectiveness of actions implemented. A SWOT Analysis was carried out to evidence the strengths and weaknesses, opportunities and threats of the process. As identification of weaknesses may be useful to identify relevant strategies for internal improvement, so the knowledge of threats can amortize factors that may have adverse impacts beyond the control of the Mental Health Department. Better understanding of the strengths and the opportunities facilitates the achievement of the goals set in the project. The first and not least upshot of this process has consisted in further integration between Primary and Mental Health Care, thus enabling the LHA to put the change into practice.

Implementation of a pilot project for the treatment and prevention of substance abuse in children and adolescents : strengthening families for parents and youths 12-16

RESUMO: Antecendentes: Uma avaliação dos serviços de abuso de substâncias em Barbados identificou a necessidade de programas e serviços que são projetados especificamente para crianças e adolescentes. Objetivo: Realizar programa com base em evidências para reduzir a incidência de abuso de drogas entre crianças e adolescentes por meio do fortalecimento da unidade familiar através de parentalidade positiva, de maior funcionamento familiar e de resistência dos jovens. Método: Dois projetos-piloto foram realizadas com base no programa "Fortalecer as Famílias para Pais e Jovens de 12 a 16 anos (SFPY). O programa de nove semanas foi empregado como uma intervenção para criar laços familiares mais fortes, aumentar a resistência dos jovens e reduzir o abuso de drogas entre crianças e adolescentes de idades de 11 a 16 anos. A decisão foi tomada para incluir participantes de 11 anos desde que as crianças possam estar no primeiro ano da escola secundária nessa idade. IMPLEMENTATION OF SUBSTANCE ABUSE PILOT PROJECT FOR CHILDREN AND ADOLESCENTS 5 Resultados: Quinze famílias participaram em dois projetos-piloto e a avaliação final mostrou que os jovens após o programa, geralmente tornaram-se mais positivos sobre o seu lugar na unidade familiar e sentiram que sua participação no programa foi benéfica. Os pais, da mesma forma, relataram que eles conquistaram, com o programa uma relação mais positiva, uma melhor compreensão das necessidades, e consciência das mudanças de desenvolvimento de seus jovens. Desta forma, considera-se que o programa atingiu o resultado desejado de criar unidades familiares mais fortes. Conclusão: O Projeto Piloto “SFPY” foi bem sucedido em fazer pais e jovens mais conscientes de suas necessidades individuais e de responsabilidades dentro da unidade familiar. Como resultado, o relacionamentos das respectivas famílias melhorou. Estudos baseados em evidências têm demonstrado que um relação familiar mais forte diminui a incidência de uso e abuso de drogas na população adolescente, aumentando os fatores de proteção e diminuindo os fatores de risco. A implementação do programa, que foi desenvolvido e testado no ambiente norte-americano, demonstrou que era transferível para a sociedade de Barbados. No entanto, seu impacto total só pode ser determinado através de um estudo comparativo envolvendo um grupo de controle e / ou uma intervenção alternativa ao abuso de substâncias. Portanto, é recomendável que um estudo comparativo da intervenção SFPY deve envolver uma amostra representativa de adolescentes que estão em estágio de desenvolvimento anterior mais cedo. Evidências já demonstram que o programa é mais eficaz, com impacto mais longo sobre os jovens que participam em uma idade maisABSTRACT:Background: An evaluation of substance abuse services in Barbados has identified the need for programmes and services that are specifically designed for children and adolescents. Aim: To conduct an evidence-based programme to reduce the incidence of substance abuse among children and adolescents by strengthening the family unit through positive parenting, enhanced family functioning and youth resilience. Method: Two pilot projects were conducted based on the ‘Strengthening Families for Parents and Youths 12– 16’ (SFPY) programme. The nine-week programme was employed as an intervention to create stronger family connections, increase youth resiliency and reduce drug abuse among children and adolescents between the ages of 11 to 16. The decision was made to include participants from age 11 since children may be in the first year of secondary school at this age. IMPLEMENTATION OF SUBSTANCE ABUSE PILOT PROJECT FOR CHILDREN AND ADOLESCENTS 3 Results: Fifteen families participated in two pilot projects and an evaluation conducted at the conclusion showed that the youth were generally more positive about their perceived place in the family unit and felt that the being in the programme was generally beneficial. The parents similarly reported they had a more positive relationship with their youths and also had a better understanding of their needs, and an awareness of their developmental changes. This affirmed that the programme had achieved its desired outcome to create stronger family units. Conclusion: The SFPY Pilot Project was successful in making parents and youths more aware of their individual needs and responsibilities within the family unit. As a result relationships within their respective families were strengthened. Evidence-based studies have shown that enhanced family functioning decreases the incidence of substance use and abuse in the adolescent population by increasing protective factors and decreasing risk factors. The implementation of the programme, which was developed and tested in the North American environment, demonstrated that it was transferable to the Barbadian society. However, its full impact can only be determined through a comparative study involving a control group and/or an alternative substance abuse intervention. It is therefore recommended that a comparative study of the SFPY intervention should be delivered to a representative sample of adolescents who are at an earlier developmental stage. Evidence has shown that the programme is more effective, with longer impact on youths who participate at a younger age.

Diagnosis of hantavirus infection in humans and rodents in Ribeirão Preto, State of São Paulo, Brazil

INTRODUCTION: Hantavirus pulmonary and cardiovascular syndrome (HPCS) is an emerging serious disease in the Americas. Hantaviruses (Bunyaviridae) are the causative agents of this syndrome and are mainly transmitted through inhalation of aerosols containing the excreta of wild rodents. In the Ribeirão Preto region (state of São Paulo, Brazil), HPCS has been reported since 1998, caused by the Araraquara virus (ARAV), for which Necromys lasiurus is the rodent reservoir. This study aimed to show diagnostic results relating to infection in humans and rodents, obtained at the Virology Research Center of the Ribeirão Preto School of Medicine, University of São Paulo, between 2005 and 2008. METHODS: HPCS was diagnosed by means of ELISA and/or RT-PCR in 11 (21.2%) out of 52 suspected cases, and 54.4% of these were fatal. Furthermore, 595 wild rodents (Necromys lasiurus, Akodon sp, Calomys tener and Oligoryzomys sp) were caught between 2005 and 2008. RESULTS: Fifteen (2.5%) of these rodents presented antibodies for hantavirus, as follows: Necromys lasiurus (4%), Calomys tener (1.9%) and Akodon sp (1.5%). Nucleotide sequences obtained through RT-PCR from one HPCS patient and one Calomys tener rodent were compared with hantavirus sequences from GenBank, which showed that both were homologous with ARAV. CONCLUSIONS: This work corroborates previous studies showing that ARAV is the hantavirus causing HPCS in the Ribeirão Preto region. It also shows that rodents infected with hantavirus represent a constant risk of transmission of this virus to man.

The effectiveness of the “Processo Especial de Revitalização” as an instrument of corporate restructuring in the context of the current economic crisis

This work project intends to evaluate the effectiveness of the Portuguese Government’s strategy to promote the orderly deleveraging of the corporate sector in the context of the current economic crisis. The recommendations of the Troika and the commitments assumed under the Memorandum of Understanding signed by the Government in 2011 required the creation of formal processes to avoid disorderly deleveraging. Conclusions and recommendations were drawn based on past experiences of large-scale corporate restructuring strategies in other countries and on the analysis of financial and statistical data on companies applying for “Programa Especial de Revitalização”.

“What matters?”: The case of sustainability reporting in Spain and Portugal

This project explores the case of Sustainability Reporting in Spain and Portugal and the recently launched new generation of Global Reporting Initiative Guidelines. The sample of the study is composed of companies included in the “GRI Report list 1999-2015”. In particular 2013 onwards 51 companies that published their G4 Report are taken into consideration. An indirect study is conducted based on the content of the sustainability reports of companies that implemented the Global Report Initiatives (GRI) reporting guidelines in order to identify focus areas of sustainability reporting in Spain and Portugal, analyzing trends and patterns relevant for observation. The project also promotes a discussion of the usability of the G4 guidelines and the adoption of materiality definition.

Aprendizaje durante la ontogenia temprana: Estudio de la participación del sistema opioide en la modulación de aprendizajes mediados por el etanol. LEARNING AND EARLY ONTOGENY: ANALYSIS OF THE INVOLVEMENT OF OPIOID SYSTEM IN FETAL AND INFANTILE ETHANOL-MEDIATED EXPERIENCIES.

Este plan de trabajos es continuidad de una línea de investigación centrada en evaluar los mecanismos responsables de la adquisición, expresión y persistencia de experiencias con el etanol. A partir de ello, indagar acerca de los efectos de esta experiencia sobre comportamientos de búsqueda y autoadministración de etanol en neonatos e infantes de rata. Se pretende analizar la participación del sistema opiáceo en los mecanismos implicados en una memoria fetal y/o infantil, generada como consecuencia de la exposición etílica. En una primera etapa, nos proponemos establecer de qué manera experiencias prenatales con la droga modulan el patrón de auto-administración de alcohol y otros reforzadores, como sacarosa. En este primer bloque de experimentos realizaremos manipulaciones fetales para determinar con mayor grado de especificidad la posible acción del sistema opiáceo en los mecanismos de adquisición de una memoria etílica prenatal. Se realizarán administraciones de etanol y el antagonista opiáceo, directamente a nivel fetal, y se evaluará esta experiencia en un paradigma de condicionamiento neonatal positivo, mediado por la droga. De acuerdo a la evidencia previa, esperamos que la exposición prenatal con la droga facilite la expresión de conductas de consumo y búsqueda del etanol o hacia las claves que señalizan al psicotrópico, tanto durante la infancia como en el neonato. A su vez, cuando la droga es presentada bajo los efectos de un antagonista opiáceo esperamos que estas conductas muestren un perfil similar a las desplegadas por sujetos controles. El segundo bloque de experimentos ha sido ideado con el objeto de indagar acerca de la posible participación del sistema opiáceo en la modulación de los aspectos reforzantes de la droga, a través de un esquema de auto-administración etílica infantil. Se utilizará un paradigma de condicionamiento instrumental adaptado para ratas infantes que consta de dos instancias, una de adquisición de la conducta instrumental (DPs 14-17) en la cual los animales reciben un pulso de refuerzo, como consecuencia de la ejecución de la conducta operante. En una segunda fase se analiza el patrón de búsqueda del reforzador ya que se registra la respuesta instrumental, sin que ocurra el refuerzo por la misma. Para analizar la participación del sistema opiáceo, durante la fase de adquisición de la conducta operante (DPs 16 y 17) los animales serán re-expuestos a mínimas cantidades del reforzador, bajo los efectos de un antagonista opiáceo, momentos previos al ensayo instrumental correspondiente para cada uno de estos días (Exp. 3). Esperamos que el bloqueo del sistema opiáceo, durante esta re-exposición al etanol, sea suficiente para disminuir el patrón de respuesta instrumental hacia el refuerzo etílico. Un último experimento incorporará un tercer evento de re-exposición al etanol -bajo los efectos del antagonista- previo al ensayo de extinción de la conducta instrumental (DP 18). Este nuevo evento tiene por objeto analizar la participación de este sistema neurobiológico en los mecanismos de búsqueda de etanol. Si el sistema opiáceo participa en la modulación de patrones tanto de búsqueda como consumatorios del reforzamiento por etanol, se espera que la re-exposición a la droga bajo los efectos del antagonista, inhiba estas respuestas tanto durante la sesión de adquisición, como de extinción de la conducta operante. Este proyecto intenta profundizar en el conocimiento de los mecanismos que regulan reconocimiento, aceptación, búsqueda y consumo de etanol, como consecuencia de experiencias tempranas con la droga. A su vez, es importante identificar y estudiar los sistemas neurobiológicos involucrados en estos mecanismos. Es por ello que se intenta determinar el rol que ejerce el sistema opiáceo en la adquisición de estas experiencias etílicas a nivel fetal e infantil, que se conoce promueven la búsqueda y el consumo de la droga. Our work is directed to analyze the involvement of the opioid system in the generation of pre- and early postnatal ethanol-related memories. As a first step, maternal manipulations with ethanol will be done. Infants will be evaluated in a paradigm of infantile self-administration of different reinforcers (ethanol, sucrose or water), employing a model of operant conditioning adapted to infant rats. A second experiment will be conducted in order to analyze if a central administration of ethanol, directly to the fetus, modifies subsequent patterns of neonatal conditioned responses to an artificial nipple, mediated by ethanol reinforcing effects. Fetal presentation of ethanol will be accompanied with the injection of an opioid antagonist in order to analyze the involvement of this system in acquisition processes of a fetal ethanol-mediated memory. A second set of studies will be conducted to analyze appetitive and consummatory behaviors in an infant model of ethanol self-administration. Involvement of opioid system in the acquisition or expression of this experience will be also inquired. Infant rats (PDs14-17) have to display a target behavior (nose-poke) to gain access to 5% sucrose or 3.75% ethanol. On PD18 an extinction session will be included. At PDs16-17, 6-hr before training, pups will be re-exposed to ethanol under opioid antagonism effects (naloxone). In a follow up experiment, a re-exposure trial will be included at PD18. Prior extinction, pups will receive naloxone and will be re-exposed to ethanol. We aim to observe if opioid system is modulating etha¬nol reinforcing effects, in terms of both appetitive and consummatory behaviors.