Anticoagulant therapy with coumarin congeners. Action and guidelines

Processing of human toll-like receptor 7 by furin-like proprotein convertases is required for its accumulation and activity in endosomes

Toll-like receptor 7 (TLR7) triggers antiviral immune responses by recognizing viral single-stranded RNA in endosomes, but the biosynthetic pathway of human TLR7 (hTLR7) remains unclear. Here, we show that hTLR7 is proteolytically processed and that the C-terminal fragment selectively accumulates in endocytic compartments. hTLR7 processing occurred at neutral pH and was dependent on furin-like proprotein convertases (PCs). Furthermore, TLR7 processing was required for its functional response to TLR7 agonists such as R837 or influenza virus. Notably, proinflammatory and differentiation stimuli increased the expression of furin-like PCs in immune cells, suggesting a positive feedback mechanism for TLR7 processing during infection. Because self-RNA can under certain conditions activate TLR7 and trigger autoimmunity, our results identify furin-like PCs as a possible target to attenuate TLR7-dependent autoimmunity and other immune pathologies.

Clinical pulmonary embolus after gastric bypass surgery

BACKGROUND

Pulmonary embolus (PE) is one of the most common causes of death for patients undergoing gastric bypass surgery. The risk of developing PE has been associated with increased age, greater body mass index (BMI), and chronic venous stasis disease.

METHODS

Between 1998 and 2003, 1225 patients underwent open Roux-en-Y gastric bypass (RYGBP) surgery (258 men and 967 women) for the treatment of morbid obesity and its related disorders. The medical records for morbidly obese patients diagnosed with PE after RYGBP were identified. The presenting signs and symptoms were reviewed, and the known risk factors were analyzed. We compared the age and BMI of these patients with those of a randomly selected RYGBP control group. The Mann-Whitney U test was used to analyze the statistical significance of the results.

RESULTS

During the study period, 11 patients were diagnosed with PE (0.9%). Six patients were men and five were women, for a gender-specific incidence of PE of 2.3% in men and 0.5% in women. The average BMI was 62.5 kg/m(2) in the men and 59.1 kg/m(2) in the women, much greater than in the control group (men 53 kg/m(2) and women 52 kg/m(2); P <0.005 and P <0.05, respectively). All male patients were super-obese (BMI >50 kg/m(2)). The total number of super-obese patients undergoing RYGBP during the study period was 147, for an incidence of PE in super-obese men of 4%. Nine of the 11 patients developed PE after discharge from the hospital within an average of 10 days.

CONCLUSION

The super-obese male patient is at a much greater risk of developing PE than other RYGBP patients (relative risk 4.4). The risk extends to several weeks after discharge. Therefore, extending PE prophylaxis to several weeks after surgery may be warranted.

Clinical experience with an oral anticoagulant in children

Nineteen cardiac patients were given warfarin sodium to prevent thrombosis and embolism. Empirical dosage resulted in long hospital stays to obtain a stable therapeutic prothrombin time. Using a dosage of 0 therefore 5-0 therefore 7 mg/kg, therapeutic levels were achieved in a much shorter time. When prothrombin time was excessive, it was successfully reduced with vitamin K or plasma. A haematoma in one case and haematuria in another were easily controlled. Warfarin sodium appears to be appropriate and effective for children requiring anticoagulants within the above dosage limits and with meticulous follow-up.