Yusuke Fuse

Development of capillary networks from rat microvascular fragments in vitro: The role of myofibroblastic cells

A new model useful for studying capillary growth in vitro is described. When the microvessel fragments and accompanying single cells (myofibroblastic cells) from rat epididymal fat pads were co-cultivated, the myofibroblastic cells initially began to grow and reached confluence. A few days later, endothelial cells started to sprout from the vessel fragments, forming cellular cord networks on and in the multilayered myofibroblastic cells. Ultrastructurally, the lumina, surrounded by the endothelial cells having intercellular junctions, were observed at cross-sectioned cellular cords. The growth of cellular cords from the fragments always occurred after the myofibroblastic cells had reached confluence. The medium conditioned to isolated rat myofibroblastic cells stimulated not only the proliferation of the endothelial cells from the bovine capillary and human vein but also the migration of bovine capillary endothelial cells in vitro. Moreover, the extracellular matrix produced by rat myofibroblastic cells modulated the morphology of bovine capillary endothelial cells to a cordlike shape. These observations strongly suggest that the formation of the capillary in vitro is induced by myofibroblastic cells.

Enhancement of cyclic adenosine monophosphate content in bone cells by the factor extracted from a pancreatic cancer associated with hypercalcemia

A woman with exocrine pancreatic cancer presented a syndrome of humoral hypercalcemia of malignancy (HHM). Either urea extract or acid/ethanol extract of the tumor showed a dose-dependent activity to elevate cyclic adenosine monophosphate (AMP) level in rat bone cells in primary culture. When each population obtained by the sequential digestion of rat fetal calvaria was cultured individually and cyclic AMP responses to parathyroid hormone (PTH), calcitonin, and tumor extract were examined, tumor extract-sensitive cells showed a similar distribution to PTH-sensitive cells. Tumor extract and PTH, but not calcitonin, increased cyclic AMP in osteogenic cell line MC 3T3-E1. PTH receptor-mediated increase of cyclic AMP was indicated by an antagonistic action of PTH analogue, (3-34) hPTH, on increase of cyclic AMP in MC 3T3-E1 elicited by tumor extract. Human breast cancer derived cell line MCF-7 had calcitonin-sensitive adenylate cyclase, but neither PTH nor tumor extract increased cyclic AMP in the cells. On Bio-Gel P-60 column, the activity to stimulate bone cell cyclic AMP was eluted as a single peak at the molecular size between 6.5 K and 12.4 K. It was concluded that pancreatic cancer, although rather exceptional as a cause of HHM, produced a factor very similar to that reported in representative HHM tumors of human and animal models.

A case of leiomyosarcoma associated with humoral hypercalcemia of malignancy: demonstration of biological and immunological activities of parathyroid hormone-related protein in the tumor extract.

Hypercalcemia occurred in a patient with leiomyosarcoma when multiple lung metastases developed. Despite normal plasma parathyroid hormone (PTH) levels and low 1,25‐dihydroxyvitamin D, this hypercalcemic patient had a marked hypercakiuria and phosphatnria associated with an increased excretion of nephrogenous cyclic AMP (NcAMP). Administration of cisplatin ameliorated both the hypercalcemia and hypercalciuria without any reduction in tumor size or NcAMP excretion. Terminally, acute pancreatitis occurred producing a profound hypocalcemia. In the extract of tumor tissue obtained post mortem, bioactivity stimulating the generation of cyclic AMP in osteogenic cells was demonstrated along with the immunoreactive PTH‐related protein (PTH‐rP). This is the first report of a solid non‐epithelial malignancy producing PTH‐rP and associated with humoral hypercalcemia of malignancy. The hypercalcemia in this case caused acute pancreatitis, which led to a profound hypocalcemia

A Serial Section Study on Mice Langerhans Cell Granules After DNFB Painting

There are numerous ultrastructural studies on the cells containing Langerhans cell granules. And general features of Langerhans cell granules have been studied and reported with detailed description.1 The profiles of Langerhans cell granules were identified as discoid bodies with a focal vesicular expansion at the margin of the disc from three dimensional reconstruction.2,3 Our previous report4 also mentioned a three dimensional morphology of normal mice Langerhans cell granules.

Ontogenic Study on the Bronchus-Associated Lymphoid Tissue (Balt) in the Rat, with Special Reference to Dendritic Cells

In several mammalian species, the bronchus-associated lymphoid tissue (BALT) appears as condensed lymphoid aggregates to the bronchial wall. Recently, a population of antigen-bearing cells with dendritic morphology has been identified in rat respiratory tract tissue (Sertl et al., 1986). We studied on the ontogenic development of BALT with special reference to dendritic cells (DC) of rat lung ultrastructurally and immunohistochemically.