Effect of combined treatment with alendronate and calcitriol on femoral neck strength in osteopenic rats

<p>Abstract</p> <p>Background</p> <p>Hip fracture is associated with pronounced morbidity and excess mortality in elderly women with postmenopausal osteoporosis. Many drugs have been developed to treat osteoporosis and to reduce the risk of osteoporotic fractures. We investigated the effects of combined alendronate and vitamin D₃treatment on bone mass and fracture load at the femoral neck in ovariectomized (OVX) rats, and evaluated the relationship between bone mass parameters and femoral neck strength.</p> <p>Methods</p> <p>Thirty 12-week-old female rats underwent either a sham-operation (n = 6) or OVX (n = 24). Twenty weeks later, OVX rats were further divided into four groups and received daily doses of either saline alone, 0.1 mg/kg alendronate, 0.1 μg/kg calcitriol, or a combination of both two drugs by continuous infusion via Alzet mini-osmotic pumps. The sham-control group received saline alone. After 12 weeks of treatment, femoral necks were examined using peripheral quantitative computed tomography (pQCT) densitometry and mechanical testing.</p> <p>Results</p> <p>Saline-treated OVX rats showed significant decreases in total bone mineral content (BMC) (by 28.1%), total bone mineral density (BMD) (by 9.5%), cortical BMC (by 26.3%), cancellous BMC (by 66.3%), cancellous BMD (by 29.0%) and total cross-sectional bone area (by 30.4%) compared with the sham-control group. The combined alendronate and calcitriol treatments improved bone loss owing to estrogen deficiency. On mechanical testing, although OVX significantly reduced bone strength of the femoral neck (by 29.3%) compared with the sham-control group, only the combined treatment significantly improved the fracture load at the femoral neck in OVX rats to the level of the sham-controls. The correlation of total BMC to fracture load was significant, but that of total BMD was not.</p> <p>Conclusion</p> <p>Our results showed that the combined treatment with alendronate and calcitriol significantly improved bone fragility of the femoral neck in OVX osteopenic rats.</p

Mapping network development of international new ventures with the use of company e-mails

International new ventures use e-mail frequently to communicate with globally dispersed contacts. In this paper we present and discuss a qualitative research method to map international network development based on company e-mails. Our approach also allows for combinations of inductive and deductive analysis and combines the possibility of content analysis and descriptive statistics with sensemaking through qualitative analysis of the narratives unfolding in the e-mail chains between the firm and its alters. We discuss these issues and examine to what extent and how structural and relational network variables and dimensions can be examined using e-mails and why this is relevant. In this discussion e-mails are also triangulated with and compared to other sources of data. The data used to exemplify our method are taken from an in-depth case study of a Dutch International New Venture. Copyright Springer Science+Business Media, LLC 2006Qualitative methods, E-mails, Data sources, Social networks, International entrepreneurship, Longitudinal,