Identification and partial sequence of a cDNA that is differentially expressed in human brain tumors.

Differential display technique was used to identify mRNAs that are differentially expressed in malignant versus benign brain tumors. Using this method, a novel 1.4-kb long cDNA (MM1) clone was isolated and sequenced.

A putative fourth Na+,K(+)-ATPase alpha-subunit gene is expressed in testis.

The Na+,K(+)-ATPase alpha subunit has three known isoforms, alpha 1, alpha 2 and alpha 3, each encoded by a separate gene. This study was undertaken to determine the functional status of a fourth human alpha-like gene, ATP1AL2. Partial genomic sequence analysis revealed regions exhibiting sequence similarity with exons 3-6 of the Na+,K(+)-ATPase alpha isoform genes.

RNA expression of complement regulatory proteins in human brain tumors.

The expression of complement regulatory proteins (CRP) on the surface of neoplastic cells has been proposed as a mechanism by which these cells evade immune surveillance. We have examined the RNA expression of the genes that encode 5 kinds of CRP in various human brain tumors to determine whether CRP expression might play a role in the malignant progression of these tumors. The benign and atypical meningiomas, and the astrocytomas showed high expression of SP-40,40, low expression of CD59, and barely detectable expression of CD46, CD55 and S-protein.

Characterisation of Na/K-ATPase, its isoforms, and the inotropic response to ouabain in isolated failing human hearts.

Objective: The aim was to determine whether failing human hearts have increased sensitivity to the inotropic and toxic effects of ouabain, and to examine alterations in Na/K-ATPase that might explain the observed higher ouabain sensitivity.

Methods: For contractility studies, a total of 57 trabeculae were isolated from two non-failing (death from head injury) and 10 terminally failing, explanted human hearts. After the experiment, each trabecula was inspected under the light microscope for morphological alterations consistent with heart failure.

Isoforms of the alpha subunit of Na,K-ATPase and their significance.

Recent studies of the Na,K-ATPase have demonstrated that multiple isoforms of both the alpha and beta subunits exist and that these are expressed in a tissue and developmental specific manner. In the case of the alpha subunit, there are three known isoforms, alpha 1, alpha 2 and alpha 3. We have examined adult human heart for the presence of these isoforms and found that all three exist in approximately equal amounts.