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.

Q: Context: Total shoulder arthroplasty (TSA) results in superior clinical outcomes to hemiarthroplasty (HA); however, TSA is a more technical and invasive procedure. This study retrospectively compares perioperative complications after HA and TSA using the National Surgical Quality Improvement Program (NSQIP) database.', 'The NSQIP user file was queried for HA and TSA cases from the years 2005 through 2010. Major complications were defined as life-threatening or debilitating. All complications occurred within 30 days of the initial procedure. We performed multivariate analysis to compare complication rates between the two procedures, controlling for patient comorbidities.', 'The database returned 1,718 patients (HA in 30.4% [n = 523] and TSA in 69.6% [n = 1,195]). The major complication rates in the HA group (5.2%, n = 29) and TSA group (5.1%, n = 61) were similar (P = .706). Rates of blood transfusions for postoperative bleeding in patients undergoing HA (2.3%, n = 12) and TSA (2.9%, n = 35) were indistinguishable (P = .458). Venous thromboembolism was a rare complication, occurring in 0.4% of patients in each group (2 HA patients and 5 TSA patients, P > .999). On multivariate analysis, the operative procedure was not associated with major complications (P = .349); however, emergency case, pulmonary comorbidity, anemia with a hematocrit level lower than 36%, and wound class of III or IV increased the risk of a major complication (P < .05 for all).\Question: Are perioperative complications after hemiarthroplasty and total shoulder arthroplasty equivalent?

A: Multivariate analysis of patients undergoing TSA or HA in the NSQIP database suggests that patient factors-not the procedure being performed-are significant predictors of major complications. Controlling for patient comorbidities, we found no increased risk of perioperative major complications in patients undergoing TSA compared with HA.
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Q: Context: Tyrphostin AGL-2043 is a potent tricyclic quinoxaline inhibitor of PDGF beta-receptor tyrosine kinase (PTK), Kit, and Flt3. We have shown previously that selective inhibition of PDGF beta-receptor PTK by tyrphostins markedly reduces SMC proliferation and migration in vitro, reduces neointima formation in balloon-injured porcine femoral arteries, and reduces neointimal stenosis in stented porcine coronary arteries when administered intramurally within biodegradable nanoparticles. The present study was designed to determine the effect of AGL-2043 delivered from a stent-based, biodegradable polymeric coating on neointima formation in the porcine coronary artery model.', 'Stents coated with biodegradable, polylactic/glycolic acid (PLGA) polymer, with (n=13) or without (n=11) 180 mcg AGL-2043 were implanted into the proximal LAD of 24 Sinclair mini-pigs (34+/-4 kg) to achieve a 1.1:1 stent/artery diameter ratio. The delivery of drug from stent to tissue was confirmed by high-performance liquid chromatography. After 28 days, histomorphometric analysis showed that in-stent stenosis in animals treated with AGL-2043 was reduced by 50% (51+/-21% versus 26+/-10%, p=0.001), the absolute neointimal area was reduced by 44% (2.38+/-1.04 versus 1.31+/-0.43 mm(2), p=0.004), and the absolute luminal area was increased by 57% (2.19+/-1.09 versus 3.39+/-0.59 mm(2), p=0.003). There were no significant differences between control and AGL-2043 in injury score (1.24+/-0.11 vs. 1.15+/-0.12, p=0.07) or inflammation score (1.19+/-0.35 vs. 1.07+/-0.33, p=0.41). Moreover, the difference in % in-stent stenosis between control and treated animals remained highly significant even after normalizing the % stenosis to the degree of injury (p=0.0008) or to the inflammation score (p=0.001). Mortality for this study was zero. Tissue concentration in segments 1 cm proximal and distal to the stents, were negligible or zero at 1 h, 24 h, and 4 weeks after stent implantation.\Question: Does tyrphostin AGL-2043 eluting stent reduce neointima formation in porcine coronary arteries?

A: Stent-based delivery of tyrphostin AGL-2043 from a biodegradable polymeric coating reduces in-stent neointimal hyperplasia in porcine coronary arteries by 50% after 28 days and preserves lumen area. Long-term studies should be the next step in testing applicability to the human interventional setting.
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Q: Context: Little is known about the role of the CO2 pneumoperitoneum on tumor cells that spread from the portal system into the liver during laparoscopic surgery for gastrointestinal malignancies. Therefore, we designed a study to investigate the effect of CO2 pneumoperitoneum on cancer cells implanted in the portal vein in a rabbit model.', 'Immediately after intraportal inoculation of 2.5x10(5) cells of VX2 cancer, the rabbits received either CO2 pneumoperitoneum at a pressure of 10 mm Hg for 30 min (pneumoperitoneum group, n = 14) or laparotomy alone for 30 min (laparotomy group, n = 14).', 'The number (p<0.01) and area of cancer nodules (p = 0.045) on the liver surface on day 17 were greater in the pneumoperitoneum group than in the laparotomy group. The frequency of cancer nodules >3.0 mm in diameter was higher in the pneumoperitoneum group than in the laparotomy group (p<0.001).\Question: Does pneumoperitoneum with carbon dioxide enhance liver metastases of cancer cells implanted into the portal vein in rabbits?

A:
Compared with laparotomy, CO2 pneumoperitoneum enhanced the development of liver metastases in this experimental model.
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