Bone
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Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed medications to treat depression and anxiety. SSRIs exert their effects by inhibiting the serotonin transporter and modulating extracellular serotonin levels, a neurotransmitter that has been shown to affect bone metabolism in animals. Studies in adults suggest a negative association between SSRI use and bone mineral density (BMD), greater rates of bone loss with SSRI use and increased risk of fractures. However, the results on bone mass have been inconsistent. Furthermore, there is a dearth of studies examining an association between SSRI use and bone mass in the pediatric and adolescent age group. ⋯ In this NHANES study, adolescents treated with SSRIs had lower DXA measurements of the total femur and lumbar spine compared to SSRI non-users. These findings support the need for future prospective studies to examine the effects of SSRI use on bone mass in adolescents.
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Periodontitis and osteoporosis are bone destructive diseases with a high prevalence in the adult population. The concomitant presence of osteoporosis may be a risk factor of progression of periodontal destruction. We studied the effect of sclerostin-neutralizing monoclonal antibody (Scl-Ab) on alveolar bone endpoints in an ovariectomized (OVX) rat model of induced experimental periodontitis. ⋯ Scl-Ab could be a potential bone anabolic agent for improving alveolar crest height and higher alveolar bone mass in conditions where alveolar bone loss in periodontitis is compounded by estrogen deficiency osteopenia.
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Vitamin D is well known for its role in promoting skeletal health. Vitamin D status is determined conventionally by circulating 25-dihydroxyvitamin D (25OHD) concentration. There is evidence indicating that circulating 25OHD concentration is affected by variation in Gc, the gene encoding the vitamin D binding protein (DBP). ⋯ This study demonstrates that different Gc variants are associated with different 25OHD concentrations in a rural Gambian population. Gc1f-1f, thought to have the highest affinity for 25OHD, had the highest 25OHD concentration compared with lower affinity Gc variants. The considerable difference in Gc1f frequency observed in Gambians compared with other non-West African populations and associated differences in plasma 25OHD concentration, may have implications for the way in which vitamin D status should be interpreted across different ancestral groups.
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Mice are the small animal model of choice in biomedical research due to the low cost and availability of genetically engineered lines. However, the devices utilized in current mouse models of implant-associated bone infection have been limited to intramedullary or trans-cortical pins, which are not amenable to treatments involving extensive debridement of a full-thickness bone loss and placement of a segmental antibiotic spacer. To overcome these limitations, we developed a clinically faithful model that utilizes a locking fracture fixation plate to enable debridement of an infected segmental bone defect (full-thickness osteotomy) during a revision surgery, and investigated the therapeutic effects of placing an antibiotic-laden spacer in the segmental bone defect. ⋯ While localized vancomycin delivery alone tended to decrease the bacterial burden and osteolysis, these effects were only significant when combined with systemic antibiotic therapy. This novel mouse model replicates key features of implant-associated osteomyelitis that make treatment extremely difficult, such as biofilm formation and osteolysis, and imitates the clinical practice of placing an antibiotic-laden spacer after infected tissue debridement. In addition, the model demonstrates the limitations of current PMMA spacers and could be an invaluable tool for evaluating alternative antimicrobial treatments for implant-associated bone infection.
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Vitamin D deficiency has reached epidemic proportions; this deficiency has been associated with osteoporosis and certain lifestyle factors in adults. This relationship is not well documented among the Lanzhou population in northwest China. This study sought to determine the prevalence of vitamin D deficiency and its risk factors in addition to its relationship with osteoporosis in a Chinese population living in Lanzhou. ⋯ Vitamin D deficiency is prevalent in the middle-aged and elderly northwestern Chinese population and is largely attributed to CHD, obesity, dyslipidemia, older age, female sex, and smoking. Reduced 25(OH)D levels are not associated with an increased osteoporosis risk.