Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1986-1-3
pubmed:abstractText
The Rice H500 tumor is a transplantable nonmetastasizing testicular tumor of Fischer rats associated with hypercalcemia and increased urine cyclic adenosine monophosphate (AMP) excretion, features similar to those of the clinical syndrome of humoral hypercalcemia of malignancy. Tumor cells can be maintained in tissue culture; one million cells grown in culture reinoculated in Fischer rats reproduce the syndrome of tumor growth and lethal hypercalcemia. Infusion of concentrated, serum-free cell culture supernatant into parathyroidectomized rats produced an increase in urine cyclic AMP similar to that produced by an infusion of bovine parathyroid hormone. Light and electron microscopic appearance of the H500 tumor in vivo and in vitro is similar to previous descriptions of a hypercalcemia-associated rat testicular tumor believed to be of Leydig cell origin. Ultrastructural characteristics of microvilli, intracellular glandlike lumina, and cell-cell attachments, however, suggest an epithelial origin. Absence of smooth endoplasmic reticulum typical of steroid-secreting Leydig cells suggest these cells are not actively involved in steroid synthesis and secretion. The ultrastructure of this tumor is sufficiently different from that of normal Leydig cells that the cell of origin is unclear. Nonetheless, this tumor provides a useful model of hormonally mediated tumor-associated hypercalcemia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0039-6060
pubmed:author
pubmed:issnType
Print
pubmed:volume
98
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1013-23
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Morphologic and functional studies of a rat hypercalcemia-associated testicular tumor maintained in cell culture.
pubmed:publicationType
Journal Article