Prairie dog colony attributes and associated vertebrate species

A survey of colony attributes and associated vertebrates on black - tail ( Cynomys ludovicianus ), Gunnison's ( C. gunnisoni ), and white - tail ( C. leucurus ) prairie dogs was made. A belt transect 1.6 km wide and 13,334 km long from Hobbs, New Mexico, to the Utah - Wyoming state line was surveyed. There were 47 colonies located (4760 ha comprising 2.2 percent) in the belt. Intercolony distances varied significantly. Three black - tail towns averaged 33 ha in area (SD = 26, range 10 – 61), II Gunnison's averaged 46 ha (SD = 43, range 16 – 150), and 33 white - tail towns averaged 125 ha (SD = 200, range 0.2 – 958). Badger activity was positively and significantly correlated to colony size and number of burrow openings on Gunnison's and white - tail towns. There were 107 vertebrate species and subspecies (one amphibian, 25 reptiles, 51 birds, 30 mammals) observed on prairie dog colonies. Results of our surveys are compared with prairie dog studies elsewhere. The role of prairie dogs and relationships to some vertebrates species are discussed.     

Molecular cloning of cDNA for murine interleukin-3

The cDNA sequence for murine interleukin-3, one of the colony stimulating factors that regulate haematopoiesis, codes for a polypeptide of 166 amino acids including a putative signal peptide. The predicted amino acid sequence indicates that formation of mature interleukin-3 involves proteolytic removal of not only the signal peptide but additional amino-terminal amino acids.     

Diabetes in transgenic mice resulting from over-expression of class I histocompatibility molecules in pancreatic beta cells

A class I histocompatibility gene, H-2Kb, linked to the rat insulin promoter, is overexpressed in the pancreatic beta cells of transgenic mice. The mice, whether syngeneic or allogeneic to the transgene, develop insulin dependent diabetes without detectable T cell infiltration, suggesting a direct, non-immune role for the transgenic class I molecules in the disease process.     

Haemonectin, a bone marrow adhesion protein specific for cells of granulocyte lineage

There is substantial evidence that the haematopoietic microenvironment is crucial to the growth and differentiation of haematopoietic cells. This microenvironment is composed of stromal cells, soluble factors and extracellular matrix (ECM). We have shown that a complex extract of bone marrow ECM can stimulate the growth and differentiation of haematopoietic cells in vitro. Furthermore, the use of inhibitors or stimulators of ECM synthesis in long-term marrow culture affects cell proliferation. On a molecular level, however, the interactions between ECM and haematopoietic cells are not well understood. We have investigated the adhesion between specific bone marrow ECM components and haematopoietic cells, and found a protein, 'haemonectin', of relative molecular mass 60,000 in bone marrow ECM which is a lineage- and organ-specific attachment molecule for cells of granulocyte lineage. This specificity distinguishes haemonectin from previously described adhesion proteins which have a wider tissue distribution and cell type specificity.     

Effect of propylthiouracil on intestinal tumor formation by azoxymethane in rats

Summary Treatment with propylthiouracil (PTU) resulted in a significant decrease in azoxymethane-induced intestinal tumors, total concentration of fecal bile acid as well as the fecal neutral steroids, cholesterol and coprostanol. Thus, a hypothyroid state induced by PTU treatment may affect intestinal carcinogenesis in this animal model by lowering the concentration of fecal bile acids and neutral steroids.We would like to acknowledge the excellent technical assistance of Dale Miller, Kenneth Kohn, Mathew McGee and Michael McLaughlin. We also wish to thank Dr M. S. Pak for the histological work, and Ms Mary Acree and Ms Kathleen Smith for the excellent secretarial assistance. Supported by the Maltida R. Wilson Fund.     

Epitaxy of rare earth element fluorcarbonate minerals from carbonatite dyke at Bayan Obo, Inner Mongolia, China

Rare earth element fluorocarbonate minerals such as bastnaesite and parisite are firstly discovered in carbonatite dykes from Bayan Obo, Inner Mongolia, China. Bastnaesite rarely occurs as homogeneously single crystal, but contains microfine phase of parisite. They form regular intergrowth along (0001) plane net, which is identified as epitaxy. This eptactic texture results from the variation of chemical composition of crystallizing agents of those minerals that crystallize directly from carbonatite magma.