Concentração de fluoreto em arroz, feijão e alimentos infantis industrializados

OBJETIVO: Determinar a concentração de fluoreto na refeição brasileira típica (arroz e feijão) e em alimentos infantis industrializados e estimar suas contribuições para fluorose dental. MÉTODOS: Os alimentos foram adquiridos de supermercados das cidades de Piracicaba e Campinas, SP, Brasil. Os alimentos infantis industrializados foram comprados em 2001 e o arroz e feijão em 2003, e imediatamente analisados. Foram analisadas três marcas de arroz, três de feijão e 36 amostras de alimentos infantis divididos em cinco grupos: prontos para o consumo; mingaus; alimentos formulados; leites em pó e outros alimentos. No arroz e feijão, foram determinadas as concentrações de fluoreto nas sementes "in natura" e após cozimento com água destilada ou fluoretada (0,7 ppm). Todas as análises de fluoreto foram feitas com eletrodo específico. Considerou-se 0,07 mg/kg/dia como a dose limite de exposição a fluoreto para risco de fluorose. RESULTADOS: A concentração de fluoreto encontrada nos grãos de arroz e feijão foi baixa. Porém, a concentração aumentou 100-200 vezes após cozimento em água fluoretada e mesmo assim, foi menor que a encontrada em alguns alimentos industrializados. Uma refeição com arroz e feijão preparada com água fluoretada seria responsável por 29% da dose limite de ingestão de fluoreto em termos de fluorose aceitável; a contribuição de alguns alimentos industrializados atingiria 45%. CONCLUSÕES: A alimentação típica brasileira, mesmo preparada com água fluoretada, é mais segura em termos de risco de fluorose dental que alguns alimentos infantis industrializados

Association between hepatitis C virus chronic infection and HLA-DRB1 and HLA-DQB1 alleles

Universidade Federal de São Paulo, São Paulo, BrazilUniv Fed Minas Gerais, Clin Hosp, Viral Hepatitis Div, Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

HLA Class II Alleles and Chronic Hepatitis C Virus Infection

The aim of this study was to investigate association of human leucocyte antigens (HLA)-DRB1 and DQB1 polymorphisms with hepatitis C virus (HCV) infection and with the occurrence of severe liver fibrosis/cirrhosis in chronically infected patients. Ninety-nine white patients, from southeast Brazil, with confirmed HCV chronic infection were included in the study. Severe fibrosis/cirrhosis (METAVIR scores F3-F4) was present in 49 patients. HLA-DRB1 specificities and DRB1*11 and DQB1* alleles were determined by PCR-SSP, and their frequencies were compared between patients and a control group of 103 healthy white Brazilian individuals. the results confirmed previous reports of the association of DRB1*11 and DQB1*03 with protection from chronic HCV infection, but did not confirm their association with protection from severe fibrosis/cirrhosis. Furthermore, the results suggested that the polymorphic sites on HLA molecules responsible for protection from chronic HCV infection are encoded not only by the DRB1*1101 and DQB1*0301, as suggested in the literature, but also by other DRB1*11 and DQB1*03 alleles. Thus, we hypothesized that the common polymorphic residues shared by different DRB1*11 and/or DQB1*03 alleles might be responsible for selection of viral epitopes for presentation to CD4(+) T cells, leading to an efficient immune response against the virus.Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Associacao Fundo de Incentivo a Psicofarmacologia (AFIP)Hosp Clin UFMG, Viral Hepatitis Div, Inst Alfa Gastroenterol, Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Dept Internal Med, Sch Med, Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pediat, Div Immunogenet, São Paulo, BrazilUniv Fed Minas Gerais, ICEX, Inst Ciencias Exatas, Belo Horizonte, MG, BrazilFundacao Oswaldo Cruz, Ctr Pesquisas Rene Rachou, Lab Biomarcadores Diagnost & Monitoracao, Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pediat, Div Immunogenet, São Paulo, BrazilWeb of Scienc

Rational design of a new class of heterobimetallic molecule-based magnets: Synthesis, crystal structures, and magnetic properties of oxamato-bridged M 3M2 (M = LiI and MnII; M = NiII and CoII) open-frameworks with a three-dimensional honeycomb architecture

[EN] Two new series of oxamato-bridged heterobimetallic coordination networks of general formula Li-5[Li3M2(mpba)(3)(H2O)(6)] center dot 31H(2)O [M= Ni-II (1a) and Co-II (1b)] and Li-2[Mn3M2(mpba)(3)(H2O)(6)] center dot 22H(2)O [M = Ni-II (2a) and Co-II (2b)] have been prepared from the metal- mediated self-assembly of the hexakis(bidentate), triple-stranded dinickel(I) and dicobalt(II) complexes [M-2(mpba)(3)](8) [mpba = meta-phenylenebis(oxamato)] with either monovalent lithium(I) or divalent manganese(II) ions respectively, in water. X-ray structural analyses of 1a and 1b show an anionic three-dimensional network formed by an infinite parallel array of oxamato-bridged (Li3M2II)-M-I (M = Ni and Co) hexagonal layers, which are interconnected through three m-phenylenediamidate bridges between the M-II ions of opposite propeller chirality (Lambda and Lambda) to give dinuclear metallacrypt and cores of the meso-helicate-type. The intralayer Li-M distance through the oxamate bridge is 5.380(3) (1a) and 5.396(5) (1b) angstrom, while the interlayer M-M distance through the triple m-phenylenediamidate bridge is 6.856(3) (1a) and 6.851(3) (1b) angstrom. Overall, this leads to an open-framework honeycomb structure with large hexagonal pores of ca. 21.8 (1a) and 21.5 angstrom (1b) in diameter which are occupied by linear arrays of water-bridged Li-I countercations. Variable-temperature (2.0-300 K) dc magnetic susceptibility and variable-field (0-5.0 T) magnetization measurements on these two series of compounds reveal a distinct magnetic behavior mainly depending on the diamagnetic or paramagnetic nature of the Li-I and Mn-II ions, respectively. Compounds 1a and 1b behave as rather well-isolated MI2II (M = Ni and Co) dimers with a moderate to weak ferromagnetic coupling(J(Ni-Ni) = + 3.17 cm (1) and J(Co-Co) = + 1.03 cm (1)) between the two M-II ions across the triple m-phenylenediamidate bridge, together with either an appreciable to remarkable local ion axial magnetic anisotropy (D-Ni = -3.35 cm (1)) or spin-orbit coupling (lambda(Co) = - 167.3 cm (1)); the next nearest-neighbor magnetic interactions between the M-II ions through the diamagnetic Li-I ions are negligible. Compounds 2a and 2b behave instead as strongly coupled oxamato-bridged (Mn3M2II)-M-II (M = Ni and Co) ferrimagnetic planes which are weakly interacting through the m-phenylenediamidate bridges, leading thus to a long-range 3D ferromagnetic order at T-C = 6.5 K. In addition, the variable-temperature (2.0-12 K) ac magnetic susceptibility measurements on 2a and 2b show an intriguing frequency-dependent magnetic behavior characteristic of a spin-glass dynamics. This glassy behavior is likely attributed to their amorphous character and/or the moderate to strong magnetic anisotropy of the dinickel(II) and dicobalt(II) precursors.This work was supported by the Ministerio de Educación y Ciencia (MEC, Spain) (Projects CTQ2007-61690 and CSD2007-00010), the Ministère de l Enseignement Supérieur et de la Recherche (MESR, France), the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil) (Project COFECUB 460/04), and the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG, Brazil) (Projects CEX1837/06 and PRONEX 526/07). D.C., E.P., and M.-C.D. thank the CAPES, the MEC, and the MESR/UPMC for grants. J.C. acknowledges the Universitat de València for an invited researcher grant.Cangussu, D.; Pardo, E.; Dul, MC.; Lescouëzec, R.; Herson, P.; Journaux, Y.; Pedroso, EF.... (2008). Rational design of a new class of heterobimetallic molecule-based magnets: Synthesis, crystal structures, and magnetic properties of oxamato-bridged M 3M2 (M = LiI and MnII; M = NiII and CoII) open-frameworks with a three-dimensional honeycomb architecture. Inorganica Chimica Acta. 361(12-13):3394-3402. https://doi.org/10.1016/j.ica.2008.02.042S3394340236112-1