RESUMO
Circulating osteogenic precursor (COP) cells are peripheral blood cells with a capacity for osteogenesis. The objective of our study was to ascertain the percentage of COPs as an early biomarker of osteoporosis and the effect of these cells in response to Denosumab (DmAb) (anti-resorptive) or to Teriparatide (TPDP) (anabolic) as very effective drugs in the treatment of the illness. A first study was conducted on healthy volunteers, with three age ranges, to determine the percentage of COPs and relate it to their anthropometric and biochemical characteristics, followed by a second longitudinal study on patients with osteoporosis, whereby one group of patients was treated with TPTD and another with DmAb. All were analyzed by cytometry for COP percentage in blood, bone turnover markers, and bone mass. Our findings show that COPs are influenced by age and become more prolific in the stages of growth and skeletal maturation. A higher percentage of COPs is found in osteoporotic disease, which could constitute a predictive marker thereof. We also show how treatment with TPTD or DmAb mobilizes circulating osteogenic precursors in the blood. Significant increases in % COPs were observed after 12 months of treatment with Dmb (21.9%) and TPTD (17%). These results can be related to an increase in osteogenesis and, consequently, a better and more efficient repair of bone tissue.
RESUMO
Bone resorption and inadequate osseointegration are considered the main problems of titanium implants. In this investigation, the texture and surface roughness of porous titanium samples obtained by the space holder technique were modified with a femtosecond Yb-doped fiber laser. Different percentages of porosity (30, 40, 50, and 60 vol.%) and particle range size (100-200 and 355-500 µm) were compared with fully-dense samples obtained by conventional powder metallurgy. After femtosecond laser treatment the formation of a rough surface with micro-columns and micro-holes occurred for all the studied substrates. The surface was covered by ripples over the micro-metric structures. This work evaluates both the influence of the macro-pores inherent to the spacer particles, as well as the micro-columns and the texture generated with the laser, on the wettability of the surface, the cell behavior (adhesion and proliferation of osteoblasts), micro-hardness (instrumented micro-indentation test, P-h curves) and scratch resistance. The titanium sample with 30 vol.% and a pore range size of 100-200 µm was the best candidate for the replacement of small damaged cortical bone tissues, based on its better biomechanical (stiffness and yield strength) and biofunctional balance (bone in-growth and in vitro osseointegration).
RESUMO
Type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases worldwide and it is associated with an increased risk of osteoporosis and fragility fractures. Our aim is to analyze the effect of T2DM on bone quality. This is a case-control study. The studied population consisted of 140 patients: 54 subjects with hip fracture (OP) without T2DM, 36 patients with hip fracture and T2DM (OP-T2DM), 28 patients with osteoarthritis (OA) without T2DM, and 22 patients with OA and T2DM (OA-T2DM). Bone markers, bone mineral density, FRAX score, microstructural, and bone material strength from femoral heads were assessed. The group with hip fracture presented lower BMD values than OA (p < 0.05). The OP, OP-T2DM, and OA-T2DM groups showed a decrease in bone volume fraction (BV/TV), in trabecular number (Tb.N), and in trabecular thickness (Tb.Th), while an increase was presented in the structural model index (SMI) and trabecular bone pattern factor (Tb.Pf), The groups OP, OP-T2DM, and OA-T2DM also presented lower values than those in group OA regarding the biomechanical parameters in the form of Young's modulus or elastic modulus, toughness, ultimate stress, ultimate load, extrinsic stiffness, and work to failure (p < 0.05). Our results show the negative effect of type 2 diabetes mellitus on trabecular bone structure and mechanical properties.
RESUMO
BACKGROUND AND OBJECTIVE: There is some controversy over bone mineral density (BMD) in children and teenagers with type 1 diabetes mellitus (DM1). We evaluated BMD by dual-energy X-ray absorptiometry (DXA) and correlated it with anthropometric, biochemical and hormonal parameters related to bone metabolism. PATIENTS AND METHOD: Sixty-six patients with DM1 (26 males and 40 females) aged between 3 and 17 years, and 327 controls with a similar age were studied. RESULTS: The BMD of all diabetic patients was not different from that of the controls. However, the subgroup of older males (between 15 and 17 years) had a significantly inferior BMD than controls of the same age: mean (standard deviation), 0.888 (0.13) versus 0.994 (0.11) (p = 0.027). BMD was inferior to -1 standard deviation (Z-score) in 21.2% of diabetic children. All the biochemical and hormonal parameters were within the normality rank. There was a negative correlation between the evolution time of the disease and the levels of 25-hydroxycholecalciferol (r = -0.345; p = 0.006). We did not observe any correlation between BMD and the remaining studied parameters. CONCLUSIONS: These results confirm that initially children and adolescents with non-complicated DM1 have no alteration of the bone mass. Yet the BMD physiological increase is smaller in the diabetic population than in controls during the adolescence period, which may cause a lower peak of bone mass in these patients.
