Manipulation of the human genome: ethics and law

A biologia molecular tem fornecido as ferramentas básicas para os geneticistas se aprofundarem nos mecanismos moleculares que influem na variação das doenças. Deve-se destacar a responsabilidade científica e moral dos pesquisadores, uma vez que os cientistas devem imaginar as consequências morais da aplicação comercial de testes genéticos, já que esse fato envolve não só o indivíduo e suas famílias, mas toda a população. Além de ser preciso, também, fazer uma reflexão sobre como essas informações do genoma humano serão utilizadas, para o bem ou mal. O objetivo desta revisão foi trazer à luz do conhecimento dados sobre características éticas da aplicação da biologia molecular, relacionando-a com os direitos do ser humano. Após análise bibliográfica, pôde-se observar que o Projeto Genoma Humano gerou várias possibilidades, como identificação de genes associados a doenças com propriedades sinergísticas, mas modificando às vezes comportamentos ao intervir geneticamente no ser humano, trazendo benefícios ou malefícios sociais. O grande desafio é decidir o que a humanidade pretende em relação a este gigantesco salto.The molecular biology has provided the basic tool for geneticists deepening in the molecular mechanisms that influence different diseases. It should be noted the scientific and moral responsibility of the researchers, because the scientists should imagine the moral consequences of the commercial application of genetic tests, since this fact involves not only the individual and their families, but the entire population. Besides being also necessary to make a reflection on how this information from the human genome will be used, for good or bad. The objective of this review was to bring the light of knowledge, data on characteristics of the ethical application of molecular biology, linking it with the rights of human beings. After studying literature, it might be observed that the Human Genome Project has generated several possibilities, such as the identification of genes associated with diseases with synergistic properties, but sometimes modifying behavior to genetically intervene in humans, bringing benefits or social harm. The big challenge is to decide what humanity wants on this giant leap

Recovery of silver residues from dental amalgam

Dental amalgam residues are probably the most important chemical residues generated from clinical dental practice because of the presence of heavy metals among its constituents, mainly mercury and silver. OBJECTIVE: The purpose of this study was to develop an alternative method for the recovery of silver residues from dental amalgam. MATERIAL AND METHODS: The residue generated after vacuum distillation of dental amalgam for the separation of mercury was initially diluted with 32.5% HNO3, followed by precipitation with 20% NaCl. Sequentially, under constant heating and agitation with NaOH and sucrose, the sample was reduced to metallic silver. However, the processing time was too long, which turned this procedure not viable. In another sequence of experiments, the dilution was accomplished with concentrated HNO3 at 90ºC, followed by precipitation with 20% NaCl. After washing, the pellet was diluted with concentrated NH4OH, water and more NaCl in order to facilitate the reaction with the reducer. RESULTS: Ascorbic acid was efficiently used as reducer, allowing a fast reduction, thus making the procedure viable. CONCLUSIONS: The proposed methodology is of easy application and does not require sophisticated equipment or expensive reagents.FAPESPODONTOPRE

Optimizing the procedure for mercury recovery from dental amalgam

Mercury, as any other heavy metal, may cause environmental damages due to its accumulation and biotransformation. Dental offices, whether private or institutional, use dental amalgam as a restorative material on a daily basis. Dental amalgam is composed of mercury (50%), silver (30%) and other metals. Approximately 30% of the amalgam prepared in dental offices (0.6 g per capsule) are wasted and inadequately discarded without any treatment. Methods for mercury recovery have been proposed previously, using high temperatures through exposure to direct flame (650°C), long processing time, and hazardous reagents as potassium cyanide. The purpose of this study was to develop a method to replace the direct flame by an electrical mantle in the process of mercury recovery. Results showed an average mercury recovery of 90% from 2 kg of amalgam after 30 minutes of processing time, thus optimizing the procedure. The proposed modifications allowed a significant reduction in processing time and a mercury recovery with high purity. The modified process also provided minimization of operator exposure to physical, chemical and ergonomic hazards, representing a technological advance compared to the risks inherent to the original method. It also provided environmental health and economy of energy resources by replacing a finite energy source (fossil and organic) by a more environmentally appropriate electric source, resulting in significant improvement of the procedure for mercury recovery from dental amalgam

Effect of chronic fluoride intake in the oxidant/antioxidant system of rats

A ingestão excessiva de fluoreto por um longo período de tempo pode resultar em fluorose, que pode causar manifestações dentárias e esqueléticas. Danos metabólicos, funcionais e estruturais causados pela fluorose crônica tem sido relatados em vários tecidos. O objetivo deste estudo foi avaliar os efeitos do fluoreto administrado na água de beber, da administração de fluoreto na água de beber na defesa antioxidante de ratos. Quatro grupos de ratos wistar foram usados (n=10/grupo). Os animais receberam água de beber contendo 0 (controle), 5, 15 ou 50 ppm de fluoreto durante 60 dias. Eles foram eutanasiados e os tecidos (fígado, rins e coração) e plasma foram coletados e homogenizados. Superóxido dismutase (SOD), catalase (CAT), glutationa peroxidase (GPx), glutationa reduzida (GSH), substâncias antioxidantes totais (SAT), substâncias reativas ao ácido tiobarbitúrico (TBARS), hidroperóxido de lipídios (HL) e fluoreto foram análisadas. Dados foram analisados por ANOVA e teste de Tukey ou Kruskal-Wallis e teste de Dunn (p<0,05). Nos rins, SOD, GPx, GSH e SAT diminuiram e fluoreto e HL aumentaram significantivamente. No fígado, CAT e TBARS diminuiram, SOD, HL e SAT aumentaram significativamente. No coração, GPx aumentou significativamente. No plasma, SOD e HL diminuiram significativamente. Em resumo, esses resultados mostram que a administração crônica de fluoreto altera o sistema antioxidante de ratos. Nosso dados sugerem que a exposição em níveis elevados de fluoreto, a conversão do ânion superóxido em água nos rins parecem ocorrer principalmente através da SOD e CAT, com baixa participação do sistema glutationa, diferindo do que parece ocorrer no fígado.Excessive fluoride intake over a long period of time could result in fluorosis, which can lead to dental and skeletal manifestations. Metabolic, functional and structural damages caused by chronic fluorosis have been reported in many tissues. The aim of this study was to evaluate the effect of fluoride, administered in drinking water, in the antioxidant defense of rats. Four groups of Wistar rats were included (n=10/group). The animals received drinking water containing 0 (control), 5, 15 or 50 ppm of fluoride during 60 days. They were euthanized and the tissues (liver, kidney and heart) and plasma were collected and homogenized. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), antioxidants, thiobarbituric acid reactive substances (TBARS), lipid hydroperoxide (LH), and fluoride were analyzed. Data were analyzed by ANOVA and Tukeys test or Kruskal-Wallis and Dunns tests (p<0.05). In the kidney SOD, GPx, GSH and SAT decreased and fluoride and LH increased significantly. In the liver, CAT and TBARS decreased and fluoride, SOD, LH and SAT increased significantly. In the heart, GPx increased significantly. In the plasma, SOD and LH decreased significantly. In summary, these results show that chronic fluoride administration alters the antioxidant system of the rats. Our data suggest that upon exposure to high levels of fluoride, the conversion of the superoxide anion to water in the kidney seems to occur mainly through the SOD and CAT, with a low participation of the glutathione system, differing from what seems to occur in the liver

PERCEPÇÃO DOS ALUNOS DO CURSO DE ODONTOLOGIA DE UMA UNIVERSIDADE BRASILEIRA EM RELAÇÃO À IMPORTÂNCIA DA DISCIPLINA DE BIOQUÍMICA NA SUA PROFISSÃO.

O aprendizado de disciplinas de ciências básicas, no curso de graduação emOdontologia, é necessário e cada vez mais exigido para a formação de um profissional atentoaos avanços tecnológicos na área da saúde. O objetivo deste trabalho foi avaliar a percepçãodos alunos do primeiro ano do curso de Odontologia da Faculdade de Odontologia de Bauru-USP, no ano de 2006, em relação à importância da disciplina de bioquímica na sua formação eatuação profissional. Foi proposto um questionário simples composto de duas questões demúltipla escolha sobre a disciplina de bioquímica, avaliando sua aplicabilidade e importância nocotidiano do cirurgião-dentista. Os alunos (n=34) responderam às questões sem a necessidadede se identificarem, para que não sofressem inibição ou mesmo receio de qualquer comentáriosobre respostas individuais. O interesse pela bioquímica se mostrou elevado. A grande maioriados alunos (88,23% e 82,35% na primeira e segunda questão respectivamente) respondeuacreditar no uso prático do conteúdo da disciplina de bioquímica na formação e atuaçãoprofissional. Uma pequena parcela (11,87% e 17,65% na primeira e segunda questão,respectivamente) respondeu não acreditar que o conteúdo da disciplina fosse importante eaplicável no cotidiano do profissional. Considerando que os alunos do primeiro ano do curso deodontologia precisão ser motivados a aprender conceitos básicos para aplicações futuras,podemos concluir que existem uma motivação e interesse pela bioquímica que devem ser, namedida do possível, mantidos pelos professores responsáveis

EXPECTATIVAS DOS ALUNOS QUANTO À IMPORTÂNCIA DA BIOQUÍMICA EM SUA CARREIRA

O objetivo do presente trabalho foi avaliar a perspectiva dos estudantes do primeiro anodos cursos de Odontologia e Fonoaudiologia sobre a importância do uso dos conhecimentosde bioquímica na aplicação clínica em suas futuras carreiras. Foram elaborados doisquestionários simples de múltipla escolha e questões abertas sobre a importância dadisciplina de bioquímica. Os questionários foram aplicados aos alunos do primeiro ano doscursos de Odontologia e Fonoaudiologia da Faculdade de Odontologia de Bauru,Universidade de São Paulo, no começo e no final da disciplina de Bioquímica (anos de 2007e 2008). Os estudantes responderam os questionários de forma voluntária e sem anecessidade de se identificarem. As respostas foram divididas em (questões de múltiplaescolha) e avaliadas quanto ao conteúdo escrito (questões abertas), indicando a opinião doaluno em cada questão. Cento e quinze estudantes responderam o primeiro questionário ecento e trinta e nove estudantes responderam o segundo. Na maioria das questões demúltipla escolha, a opinião predominante foi que a disciplina de bioquímica é importantepara sua futura carreira (59,0%) bem como para sua rotina clínica (51,1%). Podemosconcluir que os estudantes estão conscientes da importância dos conhecimentos adquiridosem Bioquímica para sua futura carreira, embora ainda não sejam capazes de definir comclareza a forma como esses conhecimentos serão aplicados

Fluoride Intensifies Hypercaloric Diet-Induced ER Oxidative Stress and Alters Lipid Metabolism.

BACKGROUND:Here, we evaluated the relationship of diet and F-induced oxidative stress to lipid metabolism in the liver of rats eating normocaloric or hypercaloric diets for two time periods (20 or 60 days). METHODS:Seventy-two 21-day-old Wistar rats were divided into 2 groups (n = 36) based on the type of diet they were eating; each of these groups was then further divided into another two groups (n = 18) based on the time periods of either 20 or 60 days, for a total of four groups. Each of these was divided into 3 subgroups (n = 6 animals/subgroup), dependent on the dose of F administered in the drinking water (0 mg/L(control), 15 mg/L or 50 mg/L). After the experimental period, blood samples and the liver were collected. Plasma samples were analyzed for HDL, cholesterol and triglycerides. Western blots were performed to probe for GRP78, Erp29, SOD2, Apo-E and SREBP in hepatic tissues. RESULTS:As expected,the expression of target proteins involved in oxidative stress increased in the F-treated groups, especially in liver tissue obtained from animals eating a hypercaloric diet. Most changes in the lipid levels and pathological conditions were seen earlier in the time period, at day 20. The morphometric analyses showed a reduction in steatosis in groups on ahypercaloric diet and treated with 50 mg F/L compared to the control, while no changes were obtained in normocaloric-fed rats. Accordingly, plasma TG was reduced in the F-treated group. The reduced expression of Apo-E in a time- and diet-dependent pattern may account for the particular decrease in steatosis in hypercaloric-fed F-treated rats. CONCLUSIONS:These results suggest that F changes liver lipid homeostasis, possibly because of the induction of oxidative stress, which seems to be higher in animals fed hypercaloric diets

Alkaline phosphatase activity in plasma and liver of rats submitted to chronic exposure to fluoride

The aim of this study was to compare the effect of fluoride (F) on alkaline phosphatase activity in the liver and plasma of the rats. Four groups of male Wistar rats (n=6), which received drinking water containing 5, 15 or 50 ppm F or deionized water (control) throughout the experiment were included in the study. The animals were euthanized and had their tissues and blood plasma collected for the analysis of fluoride and alkaline phosphatase. There was an increase in F concentration in most tissues in the animals treated with higher F concentrations, except for the heart. The alkaline phosphatase assay showed an increase in the activity in the liver and blood plasma of the animals treated with fluoride concentrations of 15 and 50 ppm (p<0.05). This study suggested that F at a concentration of 50 ppm in drinking water promotes increased the activity of alkaline phosphatase in the liver and blood plasma

Representative expression of proteins GRP-78, APO-E, SOD2, ERP-29 and of the constitutive protein β-tubulin in samples of individual animals (n = 3) from each group.

<p>Densitometric analysis was performed for 6 animals per group. <b>A.</b> Protein expression in the liver of rats in the group treated with the hypercaloric diet for 20 days; <b>B.</b> Protein expression in the liver of rats treated with the normocaloric diet for 20 days; <b>C.</b> Protein expression in the liver of rats in in the group treated with the hypercaloric diet for 60 days; <b>D.</b> Protein expression in the liver of rats treated with the normocaloric diet for 60 days. Densitometry was analyzed using the software <i>Image Studio Lite</i>. Vertical bars represent standard deviations. For each condition, distinct superscripts denote significant differences among the groups (ANOVA and Tukey’s test, p<0.05, n = 6).</p