In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Ex Input:
Context: Strontium ranelate reduces fracture risk in postmenopausal women with osteoporosis. Evidence from non-clinical studies and analyses of bone markers in phase III trials indicate that this is due to an increase in osteoblast formation and a decrease of osteoclastic resorption. The aim of this work was to investigate, in human cells, the mechanisms by which strontium ranelate is able to influence the activities of osteoblasts and osteoclasts.', 'Human primary osteoblasts were used to examine effects of strontium ranelate on replication (thymidine incorporation), differentiation (Runx2 and alkaline phosphatase) and cell survival (cell counts and caspase activity). Osteoprotegerin (OPG) was measured by quantitative reverse transcription PCR (qRT-PCR) and elisa and receptor activator of NFkappaB ligand (RANKL) by qRT-PCR and Western blot. As strontium ranelate has been proposed as an agonist of the calcium-sensing receptor (CaSR), the involvement of CaSR in the effects of strontium ranelate on OPG and RANKL expression, and cell replication was examined using siRNA.', 'Strontium ranelate increased mRNA and protein levels of OPG and suppressed those of RANKL. Strontium ranelate also stimulated osteoblast replication and differentiation and increased cell survival under stress. Knocking down CaSR suppressed strontium ranelate-induced stimulation of OPG mRNA, reduction of RANKL mRNA, and increase in replication, indicating the involvement of CaSR in these responses.\Question: Do osteoblasts play key roles in the mechanisms of action of strontium ranelate?

Ex Output:
Our results demonstrate that osteoblasts play a key role in the mechanism of action of the anti-fracture agent, strontium ranelate by mediating both its anabolic and anti-resorptive actions, at least in part, via activation of CaSR.


Ex Input:
Context: Centrifuge training, while an integral component in pilot training, is not without risks. To date there has never been a reported case of isolated transverse process fractures associated with centrifuge training.', 'A 32-yr-old Flight Surgeon underwent centrifuge training as part of an educational course. She had increasing back pain after exposure to the centrifuge. Follow-up studies showed left L2 and bilateral L3 transverse process fractures. No other contributory causes could be identified except for mild vitamin D deficiency.\Question: Do a Report of Transverse Process Fractures Secondary to the Centrifuge in a Healthy Aviator?

Ex Output:
The etiology, incidence, and treatment of transverse process fractures are examined to better prepare the clinician for the management of these cases. Puderbaugh MA. A report of transverse process fractures secondary to the centrifuge in a healthy aviator. Aerosp Med Hum Perform. 2016; 87(7):655-658.


Ex Input:
Context: While autogenous arteriovenous access is preferred, prosthetic arteriovenous grafts (AVG) are still required in a large number of patients. Infection of AVGs occurs frequently and may cause life-threatening bleeding or sepsis. Multiple treatment strategies have been advocated (ranging from graft preservation to excision with complex concomitant reconstructions), indicating a lack of consensus on appropriate management of infected AVGs. We undertook this study to evaluate if, in the setting of anastomotic involvement, brachial artery ligation distal to the origin of the deep brachial artery accompanied by total graft excision (BAL) is safe and effective.', 'All prosthetic arteriovenous graft infections managed by a single surgeon between 1995 and 2006 were reviewed retrospectively. Patients were identified from a computerized vascular registry, and data were obtained via patient charts and the electronic medical record.', 'We identified 45 AVG infections in 43 patients. Twenty-one patients (49%) demonstrated arterial anastomotic involvement and were treated with BAL; these form the cohort for this analysis. Mean patient age was 53.2 (SD 9.5) years. The primary etiologies for end stage renal disease (ESRD) were hypertension (29%), HIV (24%), and diabetes (19%). An upper arm AVG was present in 95% of patients; one (5%) had a forearm AVG. The majority of grafts were polytetrafluoroethylene (PTFE) (90%). Follow-up was 100% at 1 month, 86% at 3 months, and 67% at 6 months. No ischemic or septic complications occurred in the 21 patients who underwent BAL.\Question: Is brachial artery ligation with total graft excision a safe and effective approach to prosthetic arteriovenous graft infections?

Ex Output:

BAL is an effective and expeditious method to deal with an infected arm AVG in frequently critically ill patients with densely scarred wounds. In the short term, BAL appears to be well tolerated without resulting ischemic complications. Further study with longer duration of follow-up is necessary to ascertain whether BAL results in definitive cure, or whether patients may ultimately manifest ischemic changes and require additional intervention.