641 research outputs found

    The evolution of social philopatry in female primates

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    The transition from solitary life to sociality is considered one of the major transitions in evolution. In primates, this transition is currently not well understood. Traditional verbal models appear insufficient to unravel the complex interplay of environmental and demographic factors involved in the evolution of primate sociality, and recent phylogenetic reconstructions have produced conflicting results. We therefore analyze a theoretical model for the evolution of female social philopatry that sheds new light on the question why most primates live in groups. In individual-based simulations, we study the evolution of dispersal strategies of both resident females and their offspring. The model reveals that social philopatry can evolve through kin selection, even if retention of offspring is costly in terms of within-group resource competition and provides no direct benefits. Our model supports the role of predator avoidance as a selective pressure for group-living in primates, but it also suggests that a second benefit of group-living, communal resource defense, might be required to trigger the evolution of sizable groups. Lastly, our model reveals that seemingly small differences in demographic parameters can have profound effects on primate social evolution

    Capture the fracture: a best practice framework and global campaign to break the fragility fracture cycle

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    Summary The International Osteoporosis Foundation (IOF) Capture the Fracture Campaign aims to support implementation of Fracture Liaison Services (FLS) throughout the world. Introduction FLS have been shown to close the ubiquitous secondary fracture prevention care gap, ensuring that fragility fracture sufferers receive appropriate assessment and intervention to reduce future fracture risk. Methods Capture the Fracture has developed internationally endorsed standards for best practice, will facilitate change at the national level to drive adoption of FLS and increase awareness of the challenges and opportunities presented by secondary fracture prevention to key stakeholders. The Best Practice Framework (BPF) sets an international benchmark for FLS, which defines essential and aspirational elements of service delivery. Results The BPF has been reviewed by leading experts from many countries and subject to beta-testing to ensure that it is internationally relevant and fit-for-purpose. The BPF will also serve as a measurement tool for IOF to award ‘Capture the Fracture Best Practice Recognition’ to celebrate successful FLS worldwide and drive service development in areas of unmet need. The Capture the Fracture website will provide a suite of resources related to FLS and secondary fracture prevention, which will be updated as new materials become available. A mentoring programme will enable those in the early stages of development of FLS to learn from colleagues elsewhere that have achieved Best Practice Recognition. A grant programme is in development to aid clinical systems which require financial assistance to establish FLS in their localities. Conclusion Nearly half a billion people will reach retirement age during the next 20 years. IOF has developed Capture the Fracture because this is the single most important thing that can be done to directly improve patient care, of both women and men, and reduce the spiralling fracture-related care costs worldwide.</p

    Recombinant human erythropoietin α modulates the effects of radiotherapy on colorectal cancer microvessels

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    Recent data suggest that recombinant human erythropoietin (rhEPO) modulates tumour growth and therapy response. The purpose of the present study was to examine the modulation of radiotherapy (RT) effects on tumour microvessels by rhEPO in a rat colorectal cancer model. Before and after 5 × 5 Gy of RT, dynamic contrast-enhanced -magnetic resonance imaging was performed and endothelial permeability surface product (PS), plasma flow (F), and blood volume (V) were modelled. Imaging was combined with pO2 measurements, analysis of microvessel density, microvessel diameter, microvessel fractal dimension, and expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1 α (HIF-1α), Bax, and Bcl-2. We found that RT significantly reduced PS and V in control rats, but not in rhEPO-treated rats, whereas F was unaffected by RT. Oxygenation was significantly better in rhEPO-treated animals, and RT induced a heterogeneous reoxygenation in both groups. Microvessel diameter was significantly larger in rhEPO animals, whereas VEGF expression was significantly lower in the rhEPO group. No differences were observed in HIF-1α, Bax, or Bcl-2 expression. We conclude that rhEPO results in spatially heterogeneous modulation of RT effects on tumour microvessels. Direct effects of rhEPO on neoplastic endothelium are likely to explain these findings in addition to indirect effects induced by increased oxygenation

    Axillary sentinel lymph node biopsy after mastectomy: a case report

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    <p>Abstract</p> <p>Background</p> <p>Sentinel lymph node biopsy has been established as the preferred method for staging early breast cancer. A prior history of mastectomy is felt to be a contraindication.</p> <p>Case presentation</p> <p>A patient with recurrent breast cancer in her skin flap was discovered to have positive axillary sentinel nodes by sentinel lymph node biopsy five years after mastectomy for ductal carcinoma in situ.</p> <p>Conclusion</p> <p>A prior history of mastectomy may not be an absolute contraindication to sentinel lymph node biopsy.</p

    Esophageal perforation in South of Sweden: Results of surgical treatment in 125 consecutive patients

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    <p>Abstract</p> <p>Background</p> <p>For many years there has been a debate as to which is the method of choice in treating patients with esophageal perforation. The literature consists mainly of small case series. Strategies for aiding patients struck with this disease is changing as new and less traumatic treatment options are developing. We studied a relatively large consecutive material of esophageal perforations in an effort to evaluate prognostic factors, diagnostic efforts and treatment strategy in these patients.</p> <p>Methods</p> <p>125 consecutive patients treated at the University Hospital of Lund from 1970 to 2006 were studied retrospectively. Prognostic factors were evaluated using the Cox proportional hazards model.</p> <p>Results</p> <p>Pre-operative ASA score was the only factor that significantly influenced outcome. Neck incision for cervical perforation (n = 8) and treatment with a covered stent with or without open drainage for a thoracic perforation (n = 6) had the lowest mortality. Esophageal resection (n = 8) had the highest mortality. A CAT scan or an oesophageal X-ray with oral contrast were the most efficient diagnostic tools. The preferred treatment strategy changed over the course of the study period, from a more aggressive surgical approach towards using covered stents to seal the perforation.</p> <p>Conclusion</p> <p>Pre-operative ASA score was the only factor that significantly influenced outcome in this study. Treatment strategies are changing as less traumatic options have become available. Sealing an esophageal perforation with a covered stent, in combination with open or closed drainage when necessary, is a promising treatment strategy.</p
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