pH-cycling models for in vitro evaluation of the efficacy of fluoridated dentifrices for caries control: strengths and limitations

Despite a plethora of in situ studies and clinical trials evaluating the efficacy of fluoridated dentifrices on caries control, in vitro pH cycling models are still broadly used because they mimic the dynamics of mineral loss and gain involved in caries formation. This paper critically reviews the current literature on existing pH-cycling models for the in vitro evaluation of the efficacy of fluoridated dentifrices for caries control, focusing on their strengths and limitations. A search was undertaken in the MEDLINE electronic journal database using the keywords "pH-cycling", "demineralization", "remineralization", "in vitro", "fluoride", "dentifrice". The primary outcome was the decrease of demineralization or the increase of remineralization as measured by different methods (e. g.: transverse microradiography) or tooth fluoride uptake. Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. One hundred and sixteen studies were included, of which 42 addressed specifically the comparison of dentifrices using different pH-cycling models. The other studies included meta-analysis or reviews, data about the effect of different fluoride sources on de-remineralization, different methods for analysis de-remineralization and chemical variables and characteristics of dental hard tissues that might have influence on de-remineralization processes. Generally, the studies presented ability to detect known results established by clinical trials, to demonstrate dose-related responses in the fluoride content of the dentifrices, and to provide repeatability and reproducibility between tests. In order to accomplish these features satisfactorily, it is mandatory to take into account the type of substrate and baseline artificial lesion, as well as the adequate response variables and statistical approaches to be used. This critical review of literature showed that the currently available pH-cycling models are appropriate to detect dose-response and pH-response of fluoride dentifrices, and to evaluate the impact of new active principles on the effect of fluoridated dentifrices, as well as their association with other anti-caries treatments.

Performance and economic indicators of a large scale fish farming in Mato Grosso, Brazil

Performance and economic indicators of a large scale fish farm that produces round fish, located in Mato Grosso State, Brazil, were evaluated. The 130.8 ha-water surface area was distributed in 30 ponds. Average total production costs and the following economic indicators were calculated: gross income (GI), gross margin (GM), gross margin index (GMI), profitability index (PI) and profit (P) for the farm as a whole and for ten ponds individually. Production performance indicators were also obtained, such as: production cycle (PC), apparent feed conversion (FC), average biomass storage (ABS), survival index (SI) and final average weight (FAW). The average costs to produce an average 2.971 kg.ha-1 per year were: R$ 2.43, R$ 0.72 and R$ 3.15 as average variable, fixed and total costs, respectively. Gross margin and profit per year per hectare of water surface were R$ 2,316.91 and R$ 180.98, respectively. The individual evaluation of the ponds showed that the best pond performance was obtained for PI 38%, FC 1.7, ABS 0.980 kg.m-2, TS 56%, FAW 1.873 kg with PC of 12.3 months. The worst PI was obtained for the pond that displayed losses of 138%, FC 2.6, ABS 0.110 kg.m-2, SI 16% and FAW 1.811 kg. However, large scale production of round-fish in farms is economically feasible. The studied farm displays favorable conditions to improve performance and economic indicators, but it is necessary to reproduce the breeding techniques and performance indicators achieved in few ponds to the entire farm.

Diferentes Perfis de Aminoácidos para Frangos de Corte no Período de 43 a 56 Dias de Idade

Um experimento foi conduzido para avaliar o desempenho e rendimento de carcaça de duas marcas comerciais de frangos de corte alimentados com diferentes perfis de aminoácidos. Dados de desempenho (ganho de peso, consumo de ração e conversão alimentar), carcaça (rendimento de carcaça, peito, pernas, dorso, asas, pés, cabeça e gordura abdominal) e vísceras comestíveis (moela, fígado e coração) foram coletados. O experimento foi realizado no período de 43 a 56 dias de idade e o delineamento experimental foi inteiramente casualizado em esquema fatorial 2x4 (duas marcas comerciais -- Hubbard e HI-Yield, e quatro perfis de aminoácidos - NRC (1994), Rostagno et al. (1992), Degussa (1997) e AEC (1993)), com quatro repetições de 50 aves cada. Quando as diferentes recomendações foram comparadas, o nível de lisina foi mantido constante, utilizando o nível do NRC (1994) como padrão. As aves alimentadas com dietas formuladas segundo recomendações do NRC (1994) apresentaram menor ganho de peso e pior conversão alimentar. As aves da marca comercial Hubbard apresentaram melhor ganho de peso, porém o consumo e a conversão alimentar não foram alterados. O rendimento de carcaça não diferiu entre os tratamentos. Contudo, as aves da marca comercial Hubbard apresentaram melhor rendimento de pernas e as aves HI-Yield, melhor rendimento de peito. A gordura abdominal foi afetada pelos tratamentos estudados em que aves da marca comercial Hubbard e alimentadas de acordo com os níveis recomendados pelo AEC (1993) apresentaram menor porcentagem de gordura abdominal. Não ocorreu efeito significativo para as vísceras comestíveis.

Tuberculose em necropsias realizadas no Serviço de Anatomia Patológica da Faculdade de Medicina de Botucatu

Entre 6.316 necropsias realizadas, no período de 1969 a 2000, no Departamento de Patologia da Faculdade de Medicina de Botucatu da Universidade Estadual Paulista (FMB/UNESP), foram encontradas 240 necropsias com diagnóstico de tuberculose, sendo 117 registradas como doença principal (grupo tuberculose/doença principal) e 123, como doença associada (grupo tuberculose/doença associada). No grupo tuberculose/doença principal, 100% apresentavam tuberculose ativa, com 80 ocorrências em homens e 37 em mulheres e média de idade de 47,7 anos. Caquexia (37,2%) e cor pulmonale (23,7%) foram as co-morbidades mais prevalentes nesse grupo. Os pulmões estavam comprometidos em 95,7% dos casos, seguido pelos linfonodos (38,9%) e pleuras (27,1%). Os padrões morfológicos das lesões pulmonares foram: 1. miliar, 58,4%; 2. cavernas, 56,6%; 3. fibrose, 41,5%; 4. bronquiectasias, 26,5%; 5. enfisema, 19,4%; e 6. cistos, 1,7%. Cavernas foram observadas em diferentes áreas, com discreto predomínio no pulmão direito, sendo a localização apical preferencial (100%) e quase sempre bilaterais (94%). Lesões miliares, bronquiectasias e fibrose estavam distribuídas, de forma difusa e aleatória, nos pulmões. No grupo tuberculose/doença associada também houve predomínio de homens (70,8%). Nesses casos, a AIDS e o alcoolismo crônico foram as doenças principais mais freqüentes, representando 22% e 16,3%, respectivamente. Os pulmões estavam acometidos em 85,2% dessas necropsias (100% nos casos de AIDS), seguidos pelos linfonodos (31,9%) e baço (28,6%). Nossos dados corroboram a importância da necropsia no estudo e no conhecimento da tuberculose, fornecendo subsídios para uma melhor abordagem clínica e epidemiológica dessa doença em nossa região.

Interaction of shikimic acid with shikimate kinase (Retracted Article. See vol 334, pg 967, 2005)

The crystal structure of shikimate kinase from Mycobacterium tuberculosis (MtSK) complexed with MgADP and shikimic acid (shikimate) has been determined at 2.3 Angstrom resolution, clearly revealing the amino acid residues involved in shikimate binding. In MtSK, the Glu61 strictly conserved in SK forms a hydrogen bond and salt-bridge with Arg58 and assists in positioning the guanidinium group of Arg58 for shikimate binding. The carboxyl group of shikimate interacts with Arg58, Gly81, and Arg136, and hydroxyl groups with Asp34 and Gly80. The crystal structure of MtSK-MgADP-shikimate will provide crucial information for elucidation of the mechanism of SK-catalyzed reaction and for the development of a new generation of drugs against tuberculosis. (C) 2004 Elsevier B.V. All rights reserved.

Structure and Growth Kinetics of 3-Glycidoxypropyltrimethoxysilane-Derived Organic/Silica Hybrids at Different Temperatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Frugivoria em morcegos (Mammalia, Chiroptera) no Parque Estadual Intervales, sudeste do Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bone mineral density of rat femurs after hindlimb unloading and different physical rehabilitation programs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Produção de matéria seca e proteína bruta e relação folha/colmo de genótipos de capim-elefante aos 56 dias de rebrota

Doze genótipos de capim-elefante foram avaliados em um delineamento em blocos ao acaso com três repetições. A parcela experimental foi composta de quatro linhas com 3 m de comprimento, espaçadas a 1 m e adubadas com 100 kg de P2O5, 100 kg de N, 60 kg de K2O e 25 kg de micronutrientes/ha. Os genótipos diferiram significativamente quanto à altura da planta e à produção de MS, de PB e matéria seca digestível (MSD)/ha. Os genótipos CNPGL 92-94-01, CNPGL 92-79-02, CNPGL 91-06-02, CNPGL 94-07-02, CNPGL 94-09-01, BAG 66, CNPGL 93-32-02 e cv. Cameroon apresentaram os maiores rendimentos de MS, PB e MSD e não diferiram significativamente quanto à relação folha/colmo (F/C). A análise de Cluster sugeriu o agrupamento dos genótipos de maior produção de MS, PB e MSD e dos genótipos com menores produções de MS, PB e MSD.

Fracionamento de carboidratos e compostos nitrogenados de genótipos de capim-elefante aos 56 dias de rebrota

Objetivou-se neste estudo determinar as frações de carboidratos e de compostos nitrogenados de genótipos de capim-elefante, em um único corte aos 56 dias de idade, na primavera. Avaliaram-se 12 genótipos de capim-elefante em um delineamento de blocos ao acaso com três repetições, no qual a parcela experimental foi composta de quatro linhas com 3 m de comprimento, espaçadas 1 m e adubadas com 100 kg de P2O5, 100 kg de N, 60 kg de K2O e 25 kg de micronutrientes/ha. As frações de carboidratos A + B1, B2 e C diferiram entre os genótipos. Os genótipos CNPGL 92-94-01, CNPGL 92-70-02, CNPGL 91-06-02, CNPGL 91-25-01, CNPGL 93-32-02 e Cameroon apresentaram os menores valores da fração C de carboidratos. Entre as frações nitrogenadas, apenas as frações B3 e C apresentaram diferenças. Os menores valores da fração C nitrogenada foram observados nos genótipos CNPGL 92-70-02, Napier, CNPGL 94-07-02 e CNPGL 91-25-01.

Composição e digestibilidade in vitro de genótipos de capim-elefante, aos 56 dias de rebrota

Twelve elephant grass genotypes were evaluated in a randomized blocks design with three repetitions. The experimental parcel was of 4 lines with 3m of length, spaced of 1 m and fertilized with 100 kg of P2O5, 100 kg of N, 60 kg of K2O and 25 kg of micronutrients/ha. Significant differences were observed among the genotypes for neutral detergent fiber (FND), acid detergent fiber (FAD) and lignin. The genotypes CNPGL 92-70-02, CNPGL 91-25-01 and CNPGL 93-32-02 showed low values for FND, FAD and lignin, simultaneously, outstanding between the others. There were no significant differences in the levels of dry matter and crude protein contents and in in vitro dry matter digestibility between the genotypes.

Desenvolvimento e acúmulo de nutrientes em duas espécies de orquídeas: Dendorobium nobile Lindl. e Miltonia flavescens Lindl. var. stellata Regel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atropelamento de vertebrados nas rodovias MG-428 e SP-334 com análise dos fatores condicionantes e valoração econômica da fauna

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resistência de clones de seringueira à infestação por ácaros

Calacarus heveaeFeres (Eriophyidae) and Tenuipalpus heveae Baker (Tenuipalpidae) can cause heavy defoliation of rubber tree plants. From the perspective of integrated pest management, resistant clones can be an important strategy. The objective of this work was to evaluate the resistance of rubber tree clones to the attack of mites, in an experiment carried out in Votuporanga, SP. The experimental design was a randomized blocks with eighteen treatments and three replications. The treatments were the clones PB 230, PB 243, PB 252, PB 294, PB 306, PB 311, PB 312, PB 314, PB 324, PB 346, PB 350, PB 355, IAC 56, IAC 302, IAC 328, IAC 334, Fx 3899 and RRIM 600. The evaluation of C. heveae and T. heveae populations was performed by counting mites and exuviae presence in six leaflets per plot. The defoliation levels were evaluated with a score scale, varying from 0 (no defoliation) to 4 (above 75% of defoliation). Based on the results, Fx 3899 clone is resistant through non-preference and/or antibiosis to C. heveae. The IAC 56 clone is less susceptible to defoliation caused by C. heveae and T. heveae infestation.

Performance, carcass traits, and body composition of broilers fed different linseed oil levels between 21 and 56 days of age

This study was carried out to evaluate the effect of the inclusion of different linseed oil levels (0.0, 3.3, 6.6, or 9.9%) in iso-energy diets fed during the period of 21 to 56 days of age on the performance, carcass traits, and body composition of broilers. A total of 1,600 broilers were distributed according to a completely randomized experimental design consisting of four treatments with eight replicates of 40 birds per experimental unit. In the period of 21-42 days of age, weight gain increased, feed and calorie conversion ratios quadratically improved, and feed and metabolizable energy intakes linearly increased as dietary linseed oil level increased. Considering the entire experimental period, dietary linseed oil linearly increased weight gain and feed and energy intakes, and feed and calorie conversion ratios in a quadratic manner. On days 42 and 56, abdominal fat percentage and carcass yield were quadratically influenced by dietary linseed oil. Total body fat content at 56 days of age was quadratically influenced by dietary linseed levels.