Navegando por Palavras-chave "Calcium phosphate"

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    Efeito de diferentes formas de fosfato de cálcio no processo de reparo ósseo em tibia de ratos
    (Universidade Federal de São Paulo (UNIFESP), 2016-01-04) Ueno, Fabio Roberto [UNIFESP]; Renno, Ana Claudia Muniz [UNIFESP]; http://lattes.cnpq.br/4106611304688552; Universidade Federal de São Paulo (UNIFESP)
    Autograft has been widely used because has shown an osteogenic potential and is immunological inert. Nevertheless, there are restriction on this kind of graft, morbity of the donor site, infection and restrict donor areas. Hence, synthetic biomaterials have be developed as an alternative to substitute the autograft stimulus. Among several biomaterials calcium phosphate (CaP) one of the most rechearched ceramic to improve bone consolidation because it have a singular composition and a high osteogenic potential. Associate with collagen, (CaP/Col) mimic the bone content, an inorganic part (CaP) and an organic part (collagen I). Ninity percent of the organic components in the bone are collagen; therefore, this composite (CaP/Col) shoud it show a high performance. Furthermore, form is another important issue to a biomaterial graft, powder and porous scaffolds have broadly studies showing that this material can enhance cellular adhesion and angiogenesis. However, on most cases it cannot be apply on irregular bone defect. Thus, a fiber form material can be useful in an irregular bone fracture, inasmuch as the fiber form have a profitable malleability. In this context, the hypothesis of this study was that the fibers form coated with collagen showed a superior new bone formation on rats? tibial bone. Therefore, the aim of this study was to assess the characteristics of the CaPp/Col composites CaP and CaPf/C,CaPf. To be evaluating, in vitro phisical quimical characteristics as SEM, calcium Assay, pH mensuration, FT-IR and in vivo, inflammatory infiltrate, granulation tissue, new bone formation, histomorphometric and ostegenic immunomarkers (Runx 2 and RANK-L).
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    Simplified estimates of ion-activity products of calcium oxalate and calcium phosphate in mouse urine
    (Springer, 2012-08-01) Tiselius, Hans-Goran; Nogueira Ferraz, Renato Ribeiro [UNIFESP]; Heilberg, Ita Pfeferman [UNIFESP]; Karolinska Inst; Universidade Federal de São Paulo (UNIFESP)
    This study aimed at formulating simplified estimates of ion-activity products of calcium oxalate (AP(CaOx)) and calcium phosphate (AP(CaP)) in mouse urineto find the most important determinants in order to limit the analytical work-up. Literature data on mouse urine composition was used to determine the relative effect of each urine variable on the two ion-activity products. AP(CaOx) and AP(CaP) were calculated by iterative approximation with the EQUIL2 computerized program. the most important determinants for AP(CaOx) were calcium, oxalate and citrate and for AP(CaP) calcium, phosphate, citrate, magnesium and pH. Urine concentrations of the variables were used. A simplified estimate of AP(CaOx) (AP(CaOx)-index(MOUSE)) that numerically approximately corresponded to 10(8) x AP(CaOx) was given the following expression:AP(CaOx)-index(MOUSE) = 0.70 x Calcium(1.05) x Oxalate(0.95)(0.90-0.0225 x Citrate) + (6.6 x 10(-8) x Citrate(3.98))For a series of urine samples with various composition the coefficient of correlation between AP(CaOx)-index(MOUSE) and 10(8) x AP(CaOx) was 0.99 (p = 0.00000). A similar estimate of AP(CaP) (AP(CaP)-index(MOUSE)) was formulated so that it approximately would correspond numerically to 10(14) x AP(CaP) taking the following form:Ap(CaP)-index(MOUSE) = 0.05 x Calcium(1.17) x Phosphate(0.85) x Magnesium(0.18) x (pH - 4.5)(6.8) / Citrate(0.76)For a series of variations in urine composition the coefficient of correlation was 0.95 (p = 0.00000). the two approximate estimates shown in this article are simplified expressions of AP(CaOx) and AP(CaP). the intention of these theoretical calculations was not to get methods for accurate information on the saturation levels in urine, but to have mathematical tools useful for rough conclusions on the outcome of different experimental situations in mice. It needs to be emphasized that the accuracy will be negatively influenced if urine variables not included in the formulas differ very much from basic concentrations.