Genetic and environmental factors in human osteoporosis from Sub-Saharan to Mediterranean areas.

The aim of this study was to determine the prevalence of known gene polymorphisms associated with osteoporosis in postmenopausal normal women from Burkina Faso and Sicily, compared to postmenopausal Sicilian women with osteoporosis, and to establish the weight of environmental factors in the mechanism of osteoporosis. Bone mass density (BMD) was measured by phalangeal quantitative ultrasound (QUS) in Burkinabe woman and by the dual X-ray absorptiometry at the femoral neck in Sicilian women. The polymorphisms of the vitamin D receptor (VDR) gene, estrogen receptor (ESR) gene, calcitonin receptor (CTR) gene and COL1A1 collagen gene were characterized by PCR. The social characteristics of studied women were evaluated by a specific questionnaire. The observed percentages of single specific polymorphisms did not differ from that expected with exception of VDR B allele and ESR X and P allele in Burkinabe and Sicilian women, respectively. Association analyses and multivariate two-step regression model of social and molecular parameters, demonstrated that in comparison to the VDR, ESR, CTR polymorphisms, physical activities and healthy diet, associated with outdoor work are the best favourable prognostic factors for osteoporosis. A diet rich in calcium, other minerals and vitamin D in association with physical activity represents the most effective way to maintain not only a healthy bone structure but also an acceptable BMD. This is particularly true for Sub-Saharan women.

Primary afferent plasticity following deafferentation of the trigeminal brainstem nuclei in the adult rat.

Alpha-tyrosinated tubulin is a cytoskeletal protein that is involved in axonal growth and is considered a marker of neuronal plasticity in adult mammals. In adult rats, unilateral ablation of the left facial sensorimotor cortical areas induces degeneration of corticotrigeminal projections and marked denervation of the contralateral sensory trigeminal nuclei. Western blotting and real-time-PCR of homogenates of the contralateral trigeminal ganglion (TG) revealed consistent overexpression of growth proteins 15 days after left decortication in comparison with the ipsilateral side. Immunohistochemical analyses indicated marked overexpression of alpha-tyrosinated tubulin in the cells of the ganglion on the right side. Cytoskeletal changes were primarily observed in the small ganglionic neurons. Application of HRP-CT, WGA-HRP, and HRP to infraorbital nerves on both sides 15 days after left decortication showed a significant degree of terminal sprouting and neosynaptogenesis from right primary afferents at the level of the right caudalis and interpolaris trigeminal subnuclei. These observations suggest that the adaptive response of TG neurons to central deafferentation, leading to overcrowding and rearrangement of the trigeminal primary afferent terminals on V spinal subnuclei neurons, could represent the anatomical basis for distortion of facial modalities, perceived as allodynia and hyperalgesia, despite nerve integrity.