Mary C. Williams

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Within the vascular system, the mucin-type transmembrane glycoprotein T1alpha/podoplanin is predominantly expressed by lymphatic endothelium, and recent studies have shown that it is regulated by the lymphatic-specific homeobox gene Prox1. In this study, we examined the role of T1alpha/podoplanin in vascular development and the effects of gene disruption in(More)
The mitochondrial enzyme 25-hydroxyvitamin D3-1a-hydroxylase (1a-hydroxylase) plays an important role in calcium homeostasis by catalyzing synthesis of the active form of vitamin D, 1,25-dihydroxyvitamin D3, in the kidney. However, enzyme activity assays indicate that 1a-hydroxylase is also expressed in a variety of extrarenal tissues; recent cloning of(More)
Understanding of the functions and regulation of the phenotype of the alveolar type I epithelial cell has lagged behind studies of its neighbor the type II cell because of lack of cell-specific molecular markers. The recent identification of several proteins expressed by type I cells indicates that these cells may play important roles in regulation of cell(More)
We assessed the capacity of plastic-adherent cultured bone marrow cells to serve as precursors of differentiated parenchymal cells of the lung. By intravenously delivering lacZ-labeled cells into wild-type recipient mice after bleomycin-induced lung injury, we detected marrow-derived cells engrafted in recipient lung parenchyma as cells with the(More)
Alveolar type II epithelial cells are identified by the presence of characteristic lamellar inclusions visualized by transmission electron microscopy. We developed a tannic acid and polychrome stain that can visualize these intracellular inclusions in rat alveolar type II cells by light microscopy and that can be used for autoradiography. This method of(More)
A method has been developed for isolating alveolar type II cells by digesting lung tissue with elastase and "panning" the resultant cell suspension on plates coated with IgG. This method provides both high yield and purity of type II cells. In 50 experiments with rats, we obtained 35 +/- 11 X 10(6) cells/rat, 89 +/- 4% of which were type II cells (mean +/-(More)
The adsorptive properties of phospholipids of pulmonary surfactant are markedly influenced by the presence of three related proteins (26-38 KD, reduced) found in purified surfactant. Whether these proteins are pre-assembled with lipids before secretion is uncertain but would be expected for a lipoprotein secretion. We performed indirect immunocytochemistry(More)
The alveolar surface of the lung is lined by two classes of epithelial cells, type I and type II cells. Type I cells cover more than 97% of the alveolar surface. Although this cell type is felt to be essential for normal gas exchange, neither unique identifying characteristics nor functions have been described for the type I cell. We have produced(More)
In addition to its calciotropic function, the secosteroid 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) has potent nonclassical effects. In particular, local production of 1,25D(3) catalyzed by the enzyme 1alpha-hydroxylase (1alpha-OHase) may act as an autocrine/paracrine immunomodulatory mechanism. To investigate the significance of this in vascular tissue(More)