No abstract

No abstract

No abstract

Sphingosine 1-phosphate (S-1-P), a lipid mediator shown to be a ligand for aortic G protein-coupled receptor [corrected] (AGRs), endothelial differentiation gene (EDG)1, EDG3, and AGR16/EDG5, is stored in platelets and released on their activation. Platelet consumption occurs in acute liver injury. Hepatic stellate cells (HSCs) play an important role in wound healing. Effects of S-1-P on HSCs were investigated. S-1-P enhanced proliferation of culture-activated HSCs. The mitogenic effect was pertussis toxin sensitive, mitogen-activated protein kinase dependent, and more prominent at lower cell density. S-1-P increased contraction of collagen lattices containing HSCs, irrespective of activation state, in a C3 exotoxin-sensitive manner. mRNAs of EDG1 and AGR16, but not of EDG3, were detected in HSCs. In HSC activation, EDG1 mRNA levels were downregulated, whereas AGR16 mRNA levels were unchanged. Considering that HSCs are capable of production of extracellular matrices and modulation of blood flow in sinusoids, our results suggest that S-1-P may play a role in wound healing process in the liver.

Mesenteric vein thrombosis is generally difficult to diagnose and can be fatal. A case of extensive thrombosis of the mesenteric and portal veins was diagnosed early and successfully treated in a 26-year-old man with Down syndrome who was admitted to hospital because of abdominal pain, severe nausea and high fever. Ultrasonography revealed moderate ascites, and there was minimal flow in the portal vein (PV) on the Doppler examination. Computed tomography (CT) showed remarkable thickening of the walls of the small intestine and extensive thrombosis of the mesenteric, portal and splenic veins. Because neither intestinal infarction nor peritonitis was seen, combined thrombolysis and anticoagulation therapy without surgical treatment was chosen. Urokinase was administered intravenously and later through a catheter in the superior mesenteric artery. Heparin and antibiotics were given concomitantly. The patient's symptoms and clinical data improved gradually. After 10 days, CT revealed that collateral veins had developed and the thrombi in the distal portions of the mesenteric veins had dissolved, although the main trunk of the PV had not recanalized. The only risk factor of thrombosis that was detected was decreased protein S activity.