Continuous regional arterial infusion effective for children with acute necrotizing pancreatitis even under neutropenia.

Severe acute pancreatitis is one of the critical conditions that may develop in children with cancer. The leading cause of death due to acute pancreatitis is infectious pancreatitis or circulation collapse. Therefore, patients who develop acute pancreatitis while undergoing chemotherapy or after hematopoietic transplantation are at risk for a life-threatening and fatal course. We treated 140 patients with malignancy from April 2002 to March 2009 at our hospital and encountered 3 patients under neutropenia who developed severe acute pancreatitis. Two of them were successfully treated with continuous regional arterial infusion of a protease inhibitor and antibiotic even under agranulocytosis. Another patient was treated with conventional therapy with intravenous antibiotics plus a protease inhibitor and total or partial parenteral nutrition. Even though the two patients treated with continuous regional arterial infusion presented much more severe conditions, their symptoms resolved earlier. In conclusion, acute pancreatitis is one of the severe complications of childhood malignancy. Even under agranulocytosis, continuous regional arterial infusion of a protease inhibitor and antibiotic was well tolerated and effective among our cases and might reduce early death due to pancreatitis.

Role of specialized microvilli and the fertilization envelope in the spatial positioning of blastomeres in early development of embryos of the starfish Astropecten scoparius.

In the eggs of a wide range of animal species, various factors that determine the blastomeres' presumptive fate are known to locate unevenly within the egg. In the embryos of these animals, cleavage occurs not just to increase cell numbers, but also to distribute the factors to the respective blastomeres, resulting in cell specialization at the later stages. In the early cleavage stages, before the establishment of a device such as desmosomes to directly join the blastomeres, some other means is needed to keep the blastomeres together and maintain the relative positions among them. In this study, we found that the embryos of the starfish Astropecten scoparius lack the hyaline layer seen in sea urchin embryos and that blastomeres adhere to the fertilization envelope (FE) via filamentous cellular projections (fixing processes). Electron microscopy revealed the fixing processes to be specialized microvilli formed, after the elevation of the FE, by the elongation of short microvilli that pre-exist in unfertilized eggs. After the first cleavage, the two blastomeres separate from each other and finally attach to the FE. In the subsequent cleavages, the blastomeres undergo repeated cell division without separating from the FE. Between the blastomeres and the FE, only shortened fixing processes were observed. Destruction of the fixing processes caused release of the blastomeres from the FE and disturbance of the relative positions of the blastomeres, resulting in abnormal development of the embryos. These observations suggest that the fixing process is a device to keep the egg placed centrally in the FE up to the first cleavage, and after the first cleavage and beyond to anchor the blastomeres to the FE so that the FE can be used as a scaffold for morphogenesis. Electron microscopy also suggests that the inner layer of the FE, which is derived from the contents of cortical granules, reinforces the adhesion of the fixing processes to the FE. Immuno-electron microscopy, using an antibody against sea urchin hyaline layer, showed that the inner layer of the FE of starfish eggs and the hyaline layer of sea urchin eggs, which are both derived from cortical granules, contain some common elements.