Browsing by Subject "Mineralization"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Publication
    Open Access
    Changes in bone mineralization pattern, a response to local stimulus in maxilla and mandible of dogs
    (Murcia : F. Hernández, 1988) Buchanan, Mary; Sandhu, H.S.; Anderson, Colin
    A pilot study was carried out in order to verify the pattern of changes in mineralization of bone in the maxillas and mandibles of dogs which had a tooth extraction or luxation. Bone mineral content was determined using computerized microdensitometry. Significant changes in patterns of mineralization were found for alveolar bone, cortical bone and trabecular bone at the sites adjacent to the area of operation. These findings suggest that the three envelopes of jaw bones of the dogs are influenced by Regional activation phenomenon (RAP). These results have important implications for the design of clinical studies of periodontium. A more detailed study should elucidate the cellular mechanisms by which these changes occur.
  • Thumbnail Image
    Publication
    Open Access
    Distal villous lesions are clinically more relevant than proximal large muscular vessel lesions of placental fetal vascular malperfusion
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2022) Stanek, Jerzy
    Background. Fetal vascular malperfusion (FVM) can be diagnosed on placental examination based on histology of distal placental villi and large muscular placental vessels. While histology of both those placental compartments can be low grade or high grade, it is not known if these are clinically equivalent. This retrospective study aimed to compare the impact of placental distal villous and large vessel FVM lesions on clinical and placental phenotypes. Methods. Clinical and placental phenotypes of 479 consecutive ≥20 weeks of gestation at delivery cases of placental FVM were analyzed among 3 groups: Group 1: 86 cases with distal FVM (clusters of sclerotic distal villi and/or those with stromal vascular karyorrhexis and/or mineralization, and/or endothelial fragmentation by CD34 immunostain) without large vessel lesions; Group 2: 186 cases with large vessel lesions (fetal vascular ectasia, vascular thrombi, stem vessel obliteration, intramural fibrin deposition) without distal villous lesions; and Group 3: 207 cases showing both distal villous lesions and large fetal vessel lesions. Results. Statistically significant differences (Bonferroni correction) were observed in: average gestational age at delivery 31, 35, 34 weeks, fetal growth restriction 24, 9, 25%, average placental weight 318, 413, 366 g, postuterine pattern of chronic hypoxic placental injury 12, 2, 6%, luminal vascular abnormalities in stem vessels 16, 3, 11%, and high grade FVM 33, 16, 39%, among Groups 1-3, respectively. Conclusion. Because of longer time needed for its development, distal FVM portends poorer prognosis for the fetus than large vessel FVM
  • Thumbnail Image
    Publication
    Open Access
    Latexin expression correlated with mineralization of articular cartilage during progression of post-traumatic osteoarthritis in a rat model
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Martínez Calleja, América; Cruz, Raymundo; Miranda Sánchez, Magdalena; Fragoso Soriano, Rogelio; Vega López, Marco A.; Kour, Juan B.
    As latexin has been linked with chondrocyte hypertrophic differentiation it is possible that this protein may also be involved in the mineralization of cartilage in OA. Therefore, we correlated latexin expression with the mineralization marker, alkaline phosphatase and determined the mineral deposition in the articular cartilage by analyzing the Ca/P ratio and the collagen fibrils pattern, during the progression of post-traumatic OA in a rat model. OA was induced by medial meniscectomy and post-surgery exercise for 5, 10, 20 and 45 days. Protein expression in articular cartilage was evaluated by immunofluorescence, histochemistry and Western blot. Minerals and structure of collagen fibrils in the superficial zone of cartilage were analyzed by energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) respectively. Protein expression analysis showed time-dependent up- regulation of latexin during OA progression. In the cartilage, latexin expression correlated with the expression and activity of alkaline phosphatase. EDX of the superficial zone of cartilage showed a Ca/P ratio closer to theoretical values for basic calcium phosphate minerals. The presence of minerals was also analyzed indirectly with AFM, as the collagen fibril pattern was less evident in the mineralized tissue. Latexin is expressed in articular cartilage from the early stages of post-traumatic OA; however, minerals were detected after latexin expression was up-regulated, indicating that its activity precedes and remains during the pathological mineralization of cartilage. Thus, our results contribute to the identification of molecules involved in the mineralization of articular chondrocytes.
  • Thumbnail Image
    Publication
    Open Access
    Mineralization of human premolar occlusal fissures. A quantitative histochemical microanalysis
    (Murcia : F. Hernández, 2000) Campos, Antonio; Rodriguez, I.A.; Sanchez-Quevedo, M.C.; García, J.M.; Nieto-Albano, O.H.; Gómez de Ferraris, M.E.
    The mechanisms of cariogenesis in occlusal fissures remain elusive because of limited information about fissure structure and wall mineralization. The purpose of the present study was to determine the correlation between morphological patterns in occlusal fissures in human premolars and quantitative histochemical patterns of mineralization in the walls of these formations. We used scanning electron microscopy and quantitative X-ray microanalysis with the peak-tolocal background ratio method and microcrystalline calcium salts as standards. We distinguished three morphological patterns of fissures in scanning electron microscopic images. The wall of the fissures was less mineralized than the control enamel in all three types of fissures. Because the fissure walls are hypomineralized, we suggest that practicing dentists should take into account the degree of mineralization when they are preparing the fissures for the application of sealant.