Nas últimas décadas houve um grande avanço em pesquisas no desenvolvimento de medicamentos à base de plantas medicinais. Entretanto, constata-se que há pouca preocupação sobre as concentrações de elementos estáveis, bem como as concentrações de atividade de radionuclídeos naturais das séries do 238U e 232Th em plantas com esta finalidade no Brasil. A presença de minerais e radionuclídeos em plantas constitui um meio de migração destes elementos para o organismo humano, através da ingestão de chás ou medicamentos feitos com ervas medicinais. Peperomia pellucida é conhecida popularmente por erva de jabuti e por suas propriedades medicinais, como cicatrizante, analgésica, bactericida e fungicida. As amostras de Peperomia pellucida e de solo analisadas neste trabalho foram coletadas no Jardim Botânico do Rio de Janeiro e em suas proximidades. A concentração elementar de As, Ba, Br, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb e Zn foi determinada nas folhas, partes aéreas, compreendendo folhas e caule, e raiz de Peperomia pellucida, nos extratos obtidos por maceração e infusão e no solo pela técnica da Análise por Ativação Neutrônica Instrumental (AANI). O método analítico utilizado para determinar os elementos Cd, Hg e Pb foi a Espectrometria por Absorção Atômica e as atividades de 226Ra, 228Ra e 210Pb foram determinadas pela contagem alfa e beta total após separação radioquímica. A qualidade dos resultados obtidos foi verificada pela análise dos materiais de referência certificados IAEA-336 Lichen, IAEA-Soil-7, IAEA-326 Radionuclides in soil, NIST 1515 Apples Leaves e NIST 1542 Peach Leaves. Os resultados obtidos nas análises apresentaram boa precisão e exatidão. O óleo essencial e os extratos etanólico e hexânico obtidos das partes aéreas de P. pellucida foram testados in vitro, em placas de Petri, para verificar a atividade antifúngica diante ao fungo Aspergillus flavus. A atividade antifúngica baseou-se na zona de inibição e nos valores de CI50 frente ao patógeno. Também foi determinada a composição química do óleo essencial pela Cromatografia Gasosa acoplada ao Espectrômetro de Massa (GC-EM). / In recent decades, there has been a great advancement in research in developing drugs from plants. Nevertheless, little significant care exists in the literature about the stable concentration of elements, as well as the activity concentration of 238U and 232Th decay products in plants used for this purpose in Brazil. The presence of stable elements and radionuclides in plants constitutes the pathway for their migration to humans, via uptake of tea or remedies made with medicinal herbs. Peperomia pellucida, whose popular name is erva de jabuti, is a plant known by its medicinal usages, such as healing and analgesic properties plus antibacterial and antifungal activities against food fungi. In this study, the elemental composition of Peperomia pellucida and surrounding soil samples collected in the Botanical Garden in Rio de Janeiro was determined; the elemental concentration in the alcoholic extract and infusion processes of dry plants was also determined. The elemental concentration of As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn was determined in the leaves, aerial parts, including leaves, stems and roots of Peperomia pellucida, in their extracts obtained by maceration and infusions and in the surrounding soil by the Instrumental Neutron Activation Analysis (INAA). The analytical methodology used to determine the elements Cd, Hg and Pb was the Atomic Absorption Spectrometry (AAS); the activities of 226Ra, 228Ra and 210Pb were carried out by gross alpha and beta counting, after radiochemical separation. The quality of the obtained results was assured by the analyses of the certified reference materials IAEA-336 Lichen, IAEA-Soil-7, IAEA-326 Radionuclides in soil, NIST 1515 Apple Leaves and NIST 1542 Peach Leaves. The relative standard deviations and the relative errors obtained in these analyses indicated good precision and accuracy of the results. The essential oil, ethanolic and hexane extracts of Peperomia pellucida were tested for antifungal activity against Aspergillus flavus in vitro on Petri plates. The antifungal activity was based on the inhibition zone and IC50 values against the pathogen on Petri plates assays. Also, the essential oil chemical composition was determined by GC-MS.

Nas últimas décadas houve um grande avanço em pesquisas no desenvolvimento de medicamentos à base de plantas medicinais. Entretanto, constata-se que há pouca preocupação sobre as concentrações de elementos estáveis, bem como as concentrações de atividade de radionuclídeos naturais das séries do 238U e 232Th em plantas com esta finalidade no Brasil. A presença de minerais e radionuclídeos em plantas constitui um meio de migração destes elementos para o organismo humano, através da ingestão de chás ou medicamentos feitos com ervas medicinais. Peperomia pellucida é conhecida popularmente por erva de jabuti e por suas propriedades medicinais, como cicatrizante, analgésica, bactericida e fungicida. As amostras de Peperomia pellucida e de solo analisadas neste trabalho foram coletadas no Jardim Botânico do Rio de Janeiro e em suas proximidades. A concentração elementar de As, Ba, Br, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb e Zn foi determinada nas folhas, partes aéreas, compreendendo folhas e caule, e raiz de Peperomia pellucida, nos extratos obtidos por maceração e infusão e no solo pela técnica da Análise por Ativação Neutrônica Instrumental (AANI). O método analítico utilizado para determinar os elementos Cd, Hg e Pb foi a Espectrometria por Absorção Atômica e as atividades de 226Ra, 228Ra e 210Pb foram determinadas pela contagem alfa e beta total após separação radioquímica. A qualidade dos resultados obtidos foi verificada pela análise dos materiais de referência certificados IAEA-336 Lichen, IAEA-Soil-7, IAEA-326 Radionuclides in soil, NIST 1515 Apples Leaves e NIST 1542 Peach Leaves. Os resultados obtidos nas análises apresentaram boa precisão e exatidão. O óleo essencial e os extratos etanólico e hexânico obtidos das partes aéreas de P. pellucida foram testados in vitro, em placas de Petri, para verificar a atividade antifúngica diante ao fungo Aspergillus flavus. A atividade antifúngica baseou-se na zona de inibição e nos valores de CI50 frente ao patógeno. Também foi determinada a composição química do óleo essencial pela Cromatografia Gasosa acoplada ao Espectrômetro de Massa (GC-EM). / In recent decades, there has been a great advancement in research in developing drugs from plants. Nevertheless, little significant care exists in the literature about the stable concentration of elements, as well as the activity concentration of 238U and 232Th decay products in plants used for this purpose in Brazil. The presence of stable elements and radionuclides in plants constitutes the pathway for their migration to humans, via uptake of tea or remedies made with medicinal herbs. Peperomia pellucida, whose popular name is erva de jabuti, is a plant known by its medicinal usages, such as healing and analgesic properties plus antibacterial and antifungal activities against food fungi. In this study, the elemental composition of Peperomia pellucida and surrounding soil samples collected in the Botanical Garden in Rio de Janeiro was determined; the elemental concentration in the alcoholic extract and infusion processes of dry plants was also determined. The elemental concentration of As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn was determined in the leaves, aerial parts, including leaves, stems and roots of Peperomia pellucida, in their extracts obtained by maceration and infusions and in the surrounding soil by the Instrumental Neutron Activation Analysis (INAA). The analytical methodology used to determine the elements Cd, Hg and Pb was the Atomic Absorption Spectrometry (AAS); the activities of 226Ra, 228Ra and 210Pb were carried out by gross alpha and beta counting, after radiochemical separation. The quality of the obtained results was assured by the analyses of the certified reference materials IAEA-336 Lichen, IAEA-Soil-7, IAEA-326 Radionuclides in soil, NIST 1515 Apple Leaves and NIST 1542 Peach Leaves. The relative standard deviations and the relative errors obtained in these analyses indicated good precision and accuracy of the results. The essential oil, ethanolic and hexane extracts of Peperomia pellucida were tested for antifungal activity against Aspergillus flavus in vitro on Petri plates. The antifungal activity was based on the inhibition zone and IC50 values against the pathogen on Petri plates assays. Also, the essential oil chemical composition was determined by GC-MS.

Die juvenilen rheumatischen Erkrankungen sind häufiger, als von Laien angenommen wird. In der vorliegenden Studie werden Patienten der Kinderklinik und Polyklinik der Universität Würzburg genauer betrachtet um mögliche Verlaufsparameter retrospektiv auswerten zu können. Es zeigt sich, dass weibliche Patienten als häufiger von JIA-Erkrankungen betroffene länger therapiert wurden als die männlichen Patienten. Dabei erhielten sie länger NSAR und Steroide sowie häufiger MTX. Die Wahrscheinlichkeit eine Remission zu erreichen war im untersuchten Kollektiv nicht per se vom Geschlecht abhängig, jedoch geschätzt nach Kaplan und Meier zu Ungunsten der Mädchen, wie laut Literatur zu erwarten. Nicht bestätigen ließ sich ein negativer Zusammenhang zwischen erhöhten Entzündungswerten zu Beginn der Erkrankung und einer Remission im Verlauf. Weiterhin nicht bestätigen ließ sich eine generell geringere Remissionswahrscheinlichkeit bei Polyarthritis. Als prädiktive Marker für eine häufigere Remission können nach unseren Ergebnissen nun theoretisch das männliche Geschlecht (nach Kaplan und Meier) sowie erhöhte Entzündungswerte zu Beginn der Erkrankung angenommen werden. Wobei eine Remission häufiger auftrat, je schneller nach Krankheitsbeginn der Patient „an der richtigen Adresse“ vorgestellt wurde. / The frequency of juvenile idiopathic arthritis is bigger than most non-professional may expect. This trial analyzes retrospective e.g. the outcome of patients from the children's hospital of the University of Wuerzburg. In our cohort it is seen, that female patients are more often affected with rheumatism and need longer medication with NSAR and steroids, also they need more often MTX. The likelihood to reach remission did not differ between boys and girls at first sight, but rated by Kaplan and Meier the girls come out badly - like other references say, too. In our cohort there was no correlation between high inflammation values at the beginning of the disease and remission at a later time. Also it could not be seen, that children with Polyarthritis reached less often remission in general. Only regarding our data one could use male gender and higher inflammation values at the beginning of the disease as a predictive marker for a more frequent remission at a later time. Whereas the remission appeared more often in children who were presented to the "Specialist" early after the beginning of the disease.

Open celled micro and nano foams fabricated from polymers and metals have attracted tremendous attention in the recent past because of their applications in numerous areas such as catalyst carriers, filtration media, ion exchange membranes and tissue engineering scaffolds. In this study open celled polymer micro- and nano foams with controllable pore size and porosity were fabricated via solid state foaming of immiscible blends. The polymer foams were used as templates for fabricating nickel foams using an ethanol based electroless plating process. Thermal conductivity of micro- and nano foams was studied as a function of pore size and porosity using finite element and molecular dynamics based models. The effect of pore size and porosity on performance of phase change material infiltrated metal foams for thermal management was investigated via numerical models. Open celled micro foams were fabricated via solid state foaming of ethylene acrylic acid (EAA) and polystyrene (PS) co-continuous blends. Blending temperature was the main parameters affecting the formation of co-continuous structure. Gas saturation and foaming studies were performed to determine ideal processing conditions for the blend. The results indicated that saturation pressure and foaming temperature were major process parameters determining the porosity of the foamed samples. Open celled polymer templates were obtained by selective extraction of PS phase using dichloromethane (DCM). Foaming resulted in faster extraction of PS and also in a higher porosity. Open celled nano foams were fabricated via solid state foaming of polyetherimide (PEI) and polyethersulfone (PES). The effect of process parameters namely saturation pressure and temperature, desorption time, and foaming temperature and time on porosity and pore size was studied. A high gas concentration and foaming temperature were required to obtain nano pore-sized foams. Throughout the cross section there existed regions with varying pore size and porosity and solid skins at the surface regions of the foam. A solvent surface dissolution process using dimethylformamide (DMF) was employed to access the internal porous structure. Micro- and nano cellular nickel foams were fabricated from EAA and PES templates via electroless plating. The structure of the nickel foams was an inverse of the polymer templates. Ethanol based electroless plating solutions were used to ensure infiltration into the porous structure because of the small pore sizes. Finite element and molecular dynamics based models were developed to predict thermal conductivity of polymer foams as a function of pore size and porosity. Pore sizes ranging from 1 nm to 1 mm were studied. Models were partially validated using experimental data. The results showed that pore size has significant effect on thermal conductivity even for microcellular and conventional foams. When the pore size is reduced to the nanometer scale, the thermal conductivity of the nano foam dramatically reduces and the value could be lower than that of air for certain porosity levels. The extremely low thermal conductivity of polymer nanofoams is possibly due to increased phonon-phonon scattering in the solid phases of the polymer matrix in addition to low thermal conductivity of gas trapped in nano sized pores. Finite element based models were also developed to study the effect of pore size and porosity on performance of phase change material infiltrated metal foams for thermal management applications. The results showed that foams with smaller pore sizes can delay the temperature rise of the heat source for an extended period of time by rapidly dissipating heat in the phase change material. The lower temperatures resulting from the use of a smaller pore size metal foam could significantly increase the lifetime of IC chips. / text

Orientador: Alan Rodrigo Panosso / Resumo: O bioma Cerrado tem sofrido modificações nas últimas décadas, perdendo parte de sua cobertura original para culturas anuais, pastagens e florestas plantadas, tendo diferentes usos da terra. Neste trabalho, foram estudadas as interações entre os diferentes usos da terra em áreas do bioma Cerrado, bem como da dinâmica de carbono no solo e os fatores latentes formados pelos atributos físicos e químicos do solo, por meio de modelos de análise de equações estruturais, com auxílio das técnicas estatísticas multivariadas. Ensaios experimentais foram conduzidos na Fazenda de Ensino, Pesquisa e Extensão (FEPE/UNESP), localizada em Selvíria-MS: Floresta plantada de Eucalipto - Eucalyptus camaldulensis (EU); Floresta plantada de Pinus - Pinus caribaea var. hondurensis (PI); Sistema silvipastoril (SI) com uma área contendo floresta plantada de Aroeira (Myracrodruon urundeuva) e capim Braquiária (Brachiaria decumbens, e Mata Nativa (MN). Foi estudado os efeitos dos atributos físicos: densidade do solo (Ds), macroporosidade (Ma), microporosidade (Mi) e químicos com ênfase especial nas propriedades relacionadas à dinâmica do carbono no solo: matéria orgânica do solo (MO), estoque de carbono do solo (EstC), estoque de nitrogênio do solo (EstN), relação carbono e nitrogênio (C/N) e o grau de humificação da matéria orgânica do solo (HLIFS). A emissão de CO2 do solo (FCO2), umidade e temperatura do solo foram avaliados nas áreas durante três períodos distintos (definidos a partir do regime hídr... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Cerrado biome has undergone modifications in recent decades, losing part of its original cover to annual crops, pastures and planted forests, having different land uses. In this work, the interactions between the different land uses in areas of the Cerrado biome, as well as the soil carbon dynamics and the latent factors formed by the physical and chemical attributes of the soil through structural equation analysis models were studied. with the aid of multivariate statistical techniques. Experimental tests were performed at the Teaching, Research and Extension Farm (FEPE / UNESP), located in Selvíria-MS: Eucalyptus planted forest Eucalyptus camaldulensis (EU); Planted Pine Forest - Pinus caribaea var. hondurensis (PI); Silvipastoral system (SI) with an area containing Aroeira (Myracrodruon urundeuva) and native grass (Brachiaria decumbens), and Mata Nativa (MN). The effects of physical attributes: soil density (Ds), macroporosity (Ma), microporosity (Mi) and chemicals attributes were studied with special emphasis on properties related to soil carbon dynamics: soil organic matter (MO), soil carbon stock (EstC), soil nitrogen stock (EstN), carbon and nitrogen ratio (C / N), and the degree of soil organic matter (HLIFS). Soil CO2 emission (FCO2), soil moisture and temperature were evaluated in the areas during three distinct periods (defined from the water regime observed in the areas) called P1, P2 and P3, season rainfall, drought and transition, respectively, between March... (Complete abstract click electronic access below) / Doutor

http://www.pharmacol.usyd.edu.au/thesis This thesis is primarily concerned with a class of chemical compounds known as pyridazinediones, being 6-membered aromatic rings containing two adjacent nitrogen atoms (pyridazine), doubly substituted with oxygen. In particular, the work focuses on pyridazine-3,6-diones, derivatives of maleic hydrazide (1). Understanding of the chemistry of these compounds is extended, using theoretical and synthetic techniques. This thesis is also concerned with two very important classes of receptors which bind amino acids in the brain: firstly, the inhibitory GABA receptor, which binds g-aminobutyric acid (GABA) (2) in vivo, and for which muscimol (3) is an agonist of the GABAA subclass; secondly, Excitatory Amino Acid (EAA) receptors, which bind glutamate (4) in vivo, and in particular the AMPA subclass, for which (S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) (5) is an agonist. The connection between pyridazinediones and amino acid receptors is the design, synthesis, and evaluation of structures based on pyridazinediones as potential GABA and EAA receptor ligands. Techniques of theoretical chemistry, molecular modelling, synthetic chemistry, and in vitro pharmacology are used to explore pyridazine-3,6-dione derivatives as ligands.

http://www.pharmacol.usyd.edu.au/thesis This thesis is primarily concerned with a class of chemical compounds known as pyridazinediones, being 6-membered aromatic rings containing two adjacent nitrogen atoms (pyridazine), doubly substituted with oxygen. In particular, the work focuses on pyridazine-3,6-diones, derivatives of maleic hydrazide (1). Understanding of the chemistry of these compounds is extended, using theoretical and synthetic techniques. This thesis is also concerned with two very important classes of receptors which bind amino acids in the brain: firstly, the inhibitory GABA receptor, which binds g-aminobutyric acid (GABA) (2) in vivo, and for which muscimol (3) is an agonist of the GABAA subclass; secondly, Excitatory Amino Acid (EAA) receptors, which bind glutamate (4) in vivo, and in particular the AMPA subclass, for which (S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) (5) is an agonist. The connection between pyridazinediones and amino acid receptors is the design, synthesis, and evaluation of structures based on pyridazinediones as potential GABA and EAA receptor ligands. Techniques of theoretical chemistry, molecular modelling, synthetic chemistry, and in vitro pharmacology are used to explore pyridazine-3,6-dione derivatives as ligands.

This pilot study examined the effect of participation in an equine-assisted activities (EAA) program on the social functioning of participants with autism spectrum disorder (ASD). Pre- and post-assessments via the Naples Equestrian Challenge Participant Initial Evaluation were completed by a trained Certified Therapeutic Riding Instructor prior to and at the conclusion of a 12 week EAA program. 12 individuals (75% male; M age = 10.8; age range 5 – 20 years) participated. Paired-sample t-tests were conducted to examine the impact of EAA on social functioning. Analyses revealed that involvement in the EAA program resulted in a significant improvement in social functioning, but when grouped by age (5 – 10 years old, 10 – 20 years old) the effects were not significant. Lastly, individual analyses indicated that 75% of the sample had improved social functioning scores after participation in the EAA program. Results support EAA as an effective therapy for persons with ASD.

O chumbo é um metal muito tóxico e que tem ampla distribuição pela sua grande utilidade. Mesmo a exposição a baixos níveis (que não causam sintomas de intoxicação aguda) de chumbo é associada a desordens cognitivas e neurológicas. O osso é considerado o melhor marcador de exposição a chumbo. No tecido ósseo, vários elementos estão presentes, e alguns deles poderiam ter sua concentração modificada pela exposição a chumbo. Testou-se a hipótese de que haja variações nos elementos Zn e Mg nas tíbias de animais expostos a chumbo (por técnica de química analítica convencional). Testou-se também se variações em microelementos poderiam ser detectadas por técnicas semiquantitativas nas tíbias de controles e animais expostos a chumbo. O objetivo deste projeto foi caracterizar em animais expostos ao chumbo desde a gestação e controles as concentrações deste elemento no osso (tíbia) de animais de 28 e 60 dias. Além do chumbo, investigamos também a concentração de 2 outros microelementos no osso: zinco e magnésio. As medidas quantitativas de chumbo foram feitas no sangue total coletado ao final dos períodos. As medidas quantitativas de chumbo, cálcio, zinco e magnésio foram realizadas a partir de soluções ácidas obtidas pela dissolução total do osso, sendo estas utilizadas para quantificar por Espectrometria de Absorção Atômica no modo chama ou com Forno e Grafite. Mandíbulas foram análisadas em Microscopia Eletrônica de Varredura e utilizando os acessórios Eletron Dispersive Spectroscopy para os elementos mais abundantes e Wavelenght dispersive Spectroscopy para investigar por análise semiquantitativa os mais abundantes elementos inorgânicos no osso destes animais, como forma de verificar se há variações nestes microelementos nos animais expostos a chumbo em comparação com controles. Como o chumbo se concentra na superfície do esmalte, também analisou-se o esmalte de primeiros molares inferiores, a fim de verificar se era visto o sinal do elemento chumbo nestes dentes. Foram usados ratos Wistar machos de 28 e 60 dias divididos em 2 grupos: C 28D (n=5) e Pb 28D (n=5) e, C 60D (n=12) e Pb 60D (n=17). Em todas as medidas de chumbo dos grupos controle as concentrações obtidas foram próximas ao limite de detecção, e houve sempre diferença estatisticamente significante (P<0.0001) quando os controles foram comparados aos grupos expostos a chumbo. As concentrações de chumbo obtidas no sangue de animais do grupo Pb 28D foi de 8,0 ug/dl (± 1.1) e no grupo Pb 60D foi de 7,2 ug/dl (± 0.89). Houve diferença estatisticamente significante entre as massas das tíbias (aferidas em balança e também a partir da quantidade de cálcio dissolvida em solução) do grupo C 60D (0,86 g ± 0,13) e Pb 60D (0,61 g ±0,11)(p=0.0004). As concentrações de chumbo detectadas nos ossos do grupo Pb 28D foi 8,02 (± 1,12) e no grupo Pb 60D foi de 43,3ug/g (± 13,26). Concentração de zinco no osso do grupo C 60D foi 0,22 mg/g e no grupo Pb 60D foi 0,22 mg/g (p>0.05). A concentração de magnésio no osso do grupo C 60D foi de 4,89 mg/g ± 0,74 e no grupo Pb 60D foi de 4,98mg/g ±0,79 (p>0.05). Os microelementos mais abundantes detectados nas tíbias contralaterais por Microscopia Eletrônica de varredura por EDS/WDS foram cálcio, fósforo, carbono, oxigênio, magnésio, sódio e potássio, não tendo sido detectadas variações nestes elementos entre os grupos controle e expostos a chumbo de 60 dias. O chumbo foi detectado apenas na região cervical dos dentes molares por MEV-EDS, e, nesta posição, apenas na forma de óxido de chumbo (deposição extrínseca) que pode ser útil para fins forenses ou de determinação de contaminação desconhecida. As conclusões deste estudo são: Houve diferença estatisticamente significante entre as massas de osso do grupo Pb 60D e C 60D. Mesmo não havendo diferença entre as concentrações de chumbo no sangue total de animais de 28 e 60 dias, houve quantidade de chumbo 5 vezes maior nos animais Pb 60D. Não houve diferenças nas concentrações de zinco e magnésio entre controles e animais expostos a chumbo. Os microelementos mais abundantes detectados nas tibias contralaterais por Microscopia Eletrônica de varredura por EDS/WDS foram cálcio, fósforo, carbono, oxigênio, magnésio, sódio e potássio, não tendo sido detectadas variações semi-quantitativas nestes elementos. O chumbo não foi detectado nem nos grupos controle ou expostos por MEV, e nos molares só foi detectada no grupo exposto como uma deposição extrínseca. / Lead is a highly toxic metal that is ubiquitous do to its great usefulness. Exposure to even low levels of lead (which do not cause symptoms of acute poisoning) is associated with cognitive and neurological disorders. Bone is considered the best marker of exposure to lead. Several chemical elements are found in bone, and some of them may have a different concentration or distribution due to exposure to lead. We tested the hypothesis that there are variations in the elements zinc and magnesium in the tibia of animals exposed to lead (being those elements determined by a conventional analytic chemistry technique). It was also tested whether variations in microelements could be detected by semiquantitative microanalysis in tibias of controls and animals exposed to lead. The objective of this project was to determine the concentration of lead in bone (tibia) of animals exposed to lead from pregnancy to day 28 and day 60. Besides lead, zinc and magnesium were also determined. Lead was also determined in whole blood collected at the end of the 2 time points. Quantitative measurements of lead, calcium, zinc and magnesium have been made in solutions obtained by dissolution of the bone by Atomic Absorption Spectrometry using flame or Graphite Furnace. Tibias were analyzed by scanning electron microscopy using the accessories Electron Dispersive Spectroscopy and Wavelength dispersive Spectroscopy for semiquantitative analysis of inorganic elements in the bone and molars of these animals. Lower molars were also analyzed by these means. Male Wistar rats aged 28 and 60 days were used in these study. In both these ages there were animals in the control (C 28D, n = 5 and C 60D, n=12) and lead exposed group (Pb 28D, n = 5 and Pb 60D, n = 17). Lead concentrations found in control groups were close to the detection limit, and there was always statistically significant differences (P <0.0001) when control groups were compared with those exposed to lead. Blood lead of groups Pb 28D and Pb 60D was 8.0 ug/dl (± 1.1) and 7.2 ug/dl (± 0.89), respectively. There was a statistically significant difference between the masses of the tibia (measured in balance and also from the amount of calcium dissolved in solution): C 60D showing 0.86 g (± 0.13 g) and 0.61 g (± 0, 11) of the Pb 60D group (p = 0.0004). Lead concentrations increased five times when the Pb 28D group was compared with the Pb 60D (8.02 and 43.3 ug/g)(p<0.0001). Zinc concentrations were not different in the C 60D (0.22 mg/g) and in the Pb 60D group (0.22 mg/g)(p>0.05). Magnesium concentrations were 4.89 mg/g in the C 60D and 4.98 mg/g in the Pb 60D (p>0.05). The most abundant trace elements detected in the contralateral tibiae by SEM-EDS/WDS were calcium, phosphorus, carbon, oxygen, magnesium, sodium and potassium and no variations in these elements were detected between the control and lead exposed groups. Lead was detected only in the cervical region of molar teeth of the lead exposed groups by SEM-EDS. This finding revealed lead in the lead oxide (extrinsic deposition) which may be useful for forensic purposes or for determining unknown contaminations. Conclusions: There was a statistically significant difference between the bone masses of the Pb 60D and C 60D groups. While there is no difference between lead concentrations in whole blood of animals 28 and 60 days, the amount of lead was 5 times higher in animals Pb 60D. There were no differences in the concentrations of zinc and magnesium between controls and lead exposed animals. The most abundant trace elements detected in the contralateral tibiae by SEM-EDS/WDS were calcium, phosphorus, carbon, oxygen, magnesium, sodium and potassium, and no semi-quantitative variations in these elements were detected in relation to exposure to lead. Lead was not detected either in control or exposed groups by SEM, and in molars it was only detected in the exposed group as an extrinsic deposition.

No description available.