Rivaroxaban is an orally administered direct inhibitor of factor Xa. As compared with enoxaparin, rivaroxaban was more effective in preventing venous thromboembolism after hip replacement, without a significant increase in major bleeding.

This trial compared rivaroxaban with enoxaparin for thromboprophylaxis after total knee replacement. Rivaroxaban was superior to enoxaparin in the prevention of venous thrombosis, and the two drugs had similar safety profiles.

Murine studies suggest that aortic-root dilation in Marfan's syndrome is due to excessive signaling by transforming growth factor β (TGF-β) and can be mitigated by TGF-β antagonists, such as angiotensin II–receptor blockers (ARBs). This study reviewed data on 18 pediatric patients with Marfan's syndrome who had begun ARB therapy and had been followed for at least 12 months. The rate of increase in aortic-root diameter was significantly slowed after the initiation of ARB therapy.

This article reviews the genetic susceptibility to breast cancer, with emphasis on genomewide association studies that have uncovered six single-nucleotide polymorphisms with a strong statistical association with breast cancer. Individually, these alleles are associated with a small relative risk, but when combined, they could facilitate population-based screening for breast cancer.

A 42-year-old woman presents with severe pain in the right upper quadrant, which started 15 hours earlier. She has had episodic pain in that location previously that lasted up to 2 hours. She has had one episode of vomiting with the current attack. Her temperature is 38.5°C, and the heart rate is 95 beats per minute. How should her condition be evaluated and treated?

A 57-year-old woman was admitted to the hospital because of abdominal pain and weakness, 1 month after gastric bypass surgery. In the month after the operation, episodes of tachycardia, bradycardia, diarrhea, dark urine, and abdominal pain occurred, with urine cultures that were positive for bacteria. After admission, weakness and numbness in the legs and arms developed and progressed to flaccid quadriparesis. A diagnostic test was performed.

A debate exists about informing potential organ-transplant recipients about the general risks associated with transplantation and the specific risks associated with a particular organ. In this article, the authors discuss whether and how the behavioral risks of donors should be considered and how that might affect choices and outcomes.

A femoral venous catheter may be necessary when peripheral access to the circulatory system is compromised and no other sites for placing a central catheter are available. This video demonstrates the insertion of a femoral venous catheter and explains the indications and potential complications.