instruction:
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.
question:
Context: Therapeutic and prophylactic vena cava filters (VCFs) are used to prevent pulmonary embolism. Concerns exist over placing a permanent filter in a young trauma patient. Recently, retrievable VCFs have become available. One such filter is the OptEase, which has a recommended time of removal of up to 23 days after insertion. Data supporting this recommendation are sparse. Many trauma patients will need filters for more than 2 weeks, and there are no data evaluating the safety of removal after extended time periods. The purpose of this study was to determine the safety, feasibility, and reaction of the vena cava when removing the OptEase retrievable VCF at different time intervals.', 'Twenty Yorkshire cross pigs (80-113 kg) underwent general anesthesia with tiletamine and zolazepam. Filters were placed in the infrarenal vena cava (VC) through the femoral vein under fluoroscopic guidance. Animals were then divided into four groups. In group 1, filters were removed at 14 days; in group 2, at 30 days; in group 3, at 60 days; and in group 4, at 90 days. Removal was attempted using a snare-and-sheath technique through the femoral vein. Animals with successful filter removal were allowed to recover; then, the animals underwent autopsy (gross and microscopic VC examination) 2 months later. Animals with unsuccessful filter removal underwent autopsy immediately after attempted removal. Venacavograms were taken at filter insertion, at removal, and before autopsy to evaluate any VC abnormalities.', 'Successful removal of the filter in all five pigs (100%) was reliably performed only in the 14-day group. In this group, the initial VC transverse diameter was 19.4 +/- 0.8 mm and was significantly reduced to 9.8 +/- 1.1 mm (p < 0.05) immediately after removal. Sixty days later, before autopsy, VC diameter had increased to 15.3 +/- 1.9 mm, which was significantly larger than at removal (p < 0.05) but not different from the initial value. In the 30-day group, removal was successful in only one of five animals. Although removal was successful in the one pig, autopsy at 2 months postremoval revealed total occlusion of the VC. Filters could not be removed from 60- and 90-day groups. At autopsy, the VCF struts were embedded or protruded through the VC wall. Microscopic examination of the VC revealed significant scarring underneath and between the struts.\Question: Is removal of the OptEase retrievable vena cava filter feasible after extended time periods because of filter protrusion through the vena cava?
answer:
Removal of the retrievable OptEase VCF may be successfully performed up to 14 days after insertion. Strut protrusion through the VC wall prohibited successful and safe removal at extended time intervals.


question:
Context: Polycystic ovary syndrome (PCOS) is a common endocrinopathy of uncertain etiology but with strong evidence for a genetic contribution.', 'The objective of the study was to test the hypothesis that the typical polycystic ovarian morphology is a marker of inherited biochemical features in families of women with PCOS.', 'A study of probands with PCOS and their sisters.', 'Patients included 125 probands and 214 sisters. All probands had PCOS, defined by symptoms of anovulation and/or hyperandrogenism with polycystic ovaries on ultrasound. Affected sisters were defined by polycystic ovaries, regardless of symptoms, and unaffected sisters defined by normal ovarian morphology.', 'This was a clinic-based study.', 'Clinical, endocrine, and metabolic features in the various groups were compared, and estimates of broad-sense heritability were obtained using the quantitative transmission disequilibrium test.', 'Although affected sisters had fewer symptoms than probands (30% had no symptoms of PCOS), serum testosterone, androstenedione, LH, and fasting insulin and insulin sensitivity were similar in the two groups with polycystic ovaries but significantly different from those in unaffected sisters or controls. We observed moderate to high heritabilities for all traits studied in affected sister pairs, whereas heritabilities calculated from discordant siblings were substantially lower.\Question: Is ovarian morphology a marker of heritable biochemical traits in sisters with polycystic ovaries?
answer:
These data provide further evidence for a genetic basis of PCOS. The high heritability of biochemical features in probands and affected sisters, despite wide variation in symptoms, shows that not only are these biochemical traits strongly influenced by genetic factors but also, importantly, that polycystic ovarian morphology is an index of inherited traits in families with PCOS.


question:
Context: To describe the variability in rheumatology visits and referrals to other medical specialties of patients with spondyloarthritis (SpA) and to explore factors that may influence such variability.', 'Nation-wide cross-sectional study performed in 2009-2010. Randomly selected records of patients with a diagnosis of SpA and at least one visit to a rheumatology unit within the previous 2\xa0years were audited. The rates of rheumatology visits and of referrals to other medical specialties were estimated-total and between centres-in the study period. Multilevel regression was used to analyse factors associated with variability and to adjust for clinical and patient characteristics.', "1168 patients' records (45 centres) were reviewed, mainly ankylosing spondylitis (55.2\xa0%) and psoriatic arthritis (22.2\xa0%). The patients had incurred in 5908 visits to rheumatology clinics (rate 254 per 100 patient-years), 4307 visits to other medical specialties (19.6\xa0% were referrals from rheumatology), and 775 visits to specialised nurse clinics. An adjusted variability in frequenting rheumatology clinics of 15.7\xa0% between centres was observed. This was partially explained by the number of faculties and trainees. The adjusted intercentre variability for referrals to other specialties was 12.3\xa0%, and it was associated with urban settings, number of procedures, and existence of SpA dedicated clinics; the probability of a patient with SpA of being referred to other specialist may increase up to 25\xa0% depending on the treating centre.\Question: Do centre characteristics determine ambulatory care and referrals in patients with spondyloarthritis?
answer:

Frequenting rheumatology clinics and referrals to other specialists significantly varies between centres, after adjustment by patient characteristics.