Wound repair in sea urchin larvae involves pigment cells and blastocoelar cells.

Sea urchin larvae spend weeks to months feeding on plankton prior to metamorphosis. When handled in the laboratory they are easily injured, suggesting that in the plankton they are injured with some frequency. Fortunately, larval wounds are repaired through an efficient wound response with mesenchymal pigment cells and blastocoelar cells assisting as the epithelium closes. An injury to the epithelium leads to an immediate calcium transient that rapidly spreads around the entire larva and is necessary for activating pigment cell migration toward the wound. If calcium transport is blocked, the pigment cells fail to activate and remain in place. When activated, pigment cells initiate directed migration to the wound site from distances of at least 85 â€‹µm. Upon arrival at the wound site they participate in an innate immune response. Blastocoelar cells are recruited to the injury site as well, though the calcium transient is unnecessary for activating these cells. At the wound site, blastocoelar cells participate in several functions including remodeling the skeleton if it protrudes through the epithelium.

Hepatic artery reconstruction following ablative surgery for hepatobiliary and pancreatic malignancies.

OBJECTIVE: Hepatic artery (HA) reconstruction is an important part of resective surgery for advanced hepatobiliary and pancreatic malignancies, but few reports have been published. To identify indications for HA reconstruction, we retrospectively analyzed our surgical procedures and outcomes. METHODS: En-bloc resection of advanced hepatobiliary and pancreatic malignancies followed by HA reconstruction was performed in 35 patients. Patients ranged in age from 27 to 81 years and included 18 men and 17 women. The primary site of cancer included the bile duct in 22 patients, the pancreas in 7, and others in 6. Reconstruction of the HA was necessitated by HA resection due to direct cancer invasion in 29 patients and by accidental arterial injury during surgical procedure in 6 patients. RESULTS: The HA was reconstructed with end-to-end anastomosis between hepatic arteries in 17 patients. Transposition of an intra-abdominal artery, such as the gastroepiploic artery, was required in 14 patients, and arterial grafting was required in 4 patients. Although the HA patency was achieved in 30 patients, 4 cases of arterial thrombosis and 1 case of arterial rupture developed postoperatively. The overall RFS time was analyzed in all patients, and mean and median RFS times were 18 and 9 months, respectively. CONCLUSION: Although oncologic outcomes remain poor, HA resection and reconstruction can be performed in selected patients. We believe that the method of first choice for HA reconstruction is end-to-end anastomosis between HAs. A vascular autograft should be used only in selected cases.