Evaluation of femur of orchiectomized guinea pigs by bone densitometry using dual-energy x-ray absortiometry (DXA) and mechanical testing

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Immunohistochemical, tomographic, and histological study on onlay bone graft remodeling. Part III: allografts

Objective In the last decades aroused the interest for bone tissue bank as an alternative to autogenous grafting, avoiding donor sites morbidity, surgical time, and costs reduction. The purpose of the study was to compare allografts (ALg) with autografts (AUg) using histology, immunochemistry, and tomographic analysis. Material and methods Fifty-six New Zealand White rabbits were submitted to surgical procedures. Twenty animals were donors and 36 were actually submitted to onlay grafting with ALg (experimental group) and AUg (control group) randomly placed bilaterally in the mandible. Six animals of each group were sacrificed at 3, 5, 7, 10, 20, and 60 postoperative days. Immunolabeling was accomplished with osteoprotegerin (OPG); receptor activator of nuclear factor-k ligand (RANKL); alkaline phosphatase (ALP); osteopontin (OPN); vascular endothelial growth factor (VEGF); tartrate-resistant acid phosphatase (TRAP); collagen type I (COL I); and osteocalcin (OC). Density and volume of the grafts was evaluated on tomography obtained at the surgery and sacrifice. Results The ALg and AUg exhibited similar patterns of density and volume throughout the experiments. The intra-group data showed statistical differences at days 7 and 60 in comparison with other time points (P = 0.001), in both groups. A slight graft expansion from fixation until day 20 (P = 0.532) was observed in the AUg group and then resorbed significantly at the day 60 (P = 0.015). ALg volume remained stable until day 7 and decreased at day 10 (P = 0.045). The light microscopy analysis showed more efficient incorporation of AUg onto the recipient bed if compared with the ALg group. The immunohistochemical labeling picked: at days 10 and 20 with OPG in the AUg group and at day 7 with TRAP in the ALg group (P = 0.001 and P = 0.002, respectively). Conclusions ALg and AUg were not differing in patterns of volume and density during entire experiment. Histological data exhibit more efficient AUg incorporation into recipient bed compared with the ALg group. Immunohistochemistry outcomes demonstrated similar pattern for both ALg and AUg groups, except for an increasing resorption activity in the ALg group mediated by TRAP and in the AUg group by higher OPG labeling. However, this latter observation does not seem to influence clinical outcomes.

PS-042c is low-dose combined oral contraceptives use associated to lower bone mineral content variation in adolescents over a one-year period?

Background Low dose combined oral contraceptives (COC) can interfere in bone mass acquisition during adolescence. To evaluate bone mineral density (BMD) and bone mineral content (BMC) in female adolescents taking a standard low-dose (EE 20 µg/Desogestrel 150 µg) combination oral contraceptive (COC) over a one-year period and compare with healthy adolescents from the same age group not taking COCs.Methods A non-randomised parallel control study with one-year follow-up. Sixty-seven adolescents from 12 to 20 years of age, divided into COC users (n = 41) taking 20 µg EE/150 µg Desogestrel and non-user controls (n = 26), were evaluated through bone densitometry examinations at baseline and 12 months later. Comparisons between groups at study start was done through the Mann-Whitney test with significance level fixed at 5% or corresponding p value; comparisons between groups at study start and 12 months later used variations in median percentages for bone mass variables.Results COC users presented low bone mass acquisition in the lumbar spine and BMD and BMC median variations between baseline and at 12 months of 2.07% and +1.57% respectively whereas the control group presented variations of +12.16% and +16.84% for BMD and BMC, respectively, over the same period. The total body BMD and BMC presented similar evolution during the study in both groups. Statistical significance (pConclusion The use of a low COC dose (EE 20 µg/Desogestrel 150 µg) was associated to lower bone mass acquisition in adolescents during the study period.Trial registration: (Register Number):RBR-5 h9b3c

Genetic erosion risk by environmental and antropic factor applied on strategies for Lychnophora ericoides conservation

This study evaluated the genetic erosion risk factors and the strategic points for the conservation of Lychnophora ericoides population in “Paraíso Perdido” farm, Serra da Canastra (20° 37’ 54” S; 46° 19’ 37” W; 833 m height) in São João Batista do Glória City, Minas Gerais State, Brazil. The number of young and adult plants, the soil and the phenology were evaluated in two sample areas of 125 m2. Information about the species utilization was obtained with local informants. Data on the region were obtained through literature review, in loco evaluation, GPS and geo-referenced map. In addition, local use of the plant for mixtures of drug was evaluated. According to the results obtained, the soil of the population is lithic with a weathered portion of frank-sandy texture, very acidic and dystrophic. The population density is 0.16 individuals/m2, 0.078 young/adult plant. The predominant phenophase was fruiting (100% plants) followed by flowering (21.62% plants). The local community uses the leaves of the plant in the form of hydroalcoholic extracts, as anti-inflammatory. Based on the evaluated parameters, the population is at 73% risk of genetic erosion. The detected key points were the development of activities including the participation of the local community for habitat protection as well as germplasm collection, seedlings production and reintroduction, together with environmental education, supervision, and reduction in the propensity for fire.