B/Singapore/222/79-like influenza viruses isolated from three patients during the winter of 1981 to 1982 and cultured in either embryonated hens' eggs or MDCK cells were studied. Sequence analysis indicated that the haemagglutinin (HA) genes of the six virus preparations contained at least four distinct HA1 sequences which differed by up to six amino acids. Only one pair of viruses had amino ac...

The susceptibilities of culture cells to twelve avian influenza virus strains were determined with ten established cell lines including MDCK and ESK cells and three primary culture cells. The established cell lines derived from embryonic swine kidney (ESK) and chicken kidney (CK) primary culture cells were more sensitive to the avian influenza viruses than the other eleven cells. The ESK cell h...

In the present investigation, the uptake and transport kinetics of valacyclovir (VACV), 5-aminolevulinic acid (5-ALA), and benzylpenicillin (BENZ) were studied in stably transfected Madin-Darby canine kidney (MDCK)/human peptide transporter 1 (hPepT1)-V5&His clonal cell lines expressing varying levels of epitope-tagged hPepT1 protein (low, medium, and high expression) and in Caco-2 cells to del...

ZO-1, originally identified by mAb techniques, is the first protein shown to be specifically associated with the tight junction. Here we describe and compare the physical characteristics of ZO-1 from mouse liver and the Madin-Darby canine kidney (MDCK) epithelial cell line. The ZO-1 polypeptide has an apparent size of 225 kD in mouse tissues and 210 kD in canine-derived MDCK cells as determined...

The epithelial-mesenchymal transition (EMT) is involved in neoplastic metastasis, and the RON protein may be involved. In the present study, we determined the role and the mechanisms of action of RON in EMT in Madin-Darby canine kidney (MDCK) cells by Western blot and cell migration analysis. Activation of RON by macrophage stimulating protein (MSP) results in cell migration and initiates chang...

Migration plays an important role in the formation of tumor metastases. Nonetheless, little is known about electrophysiological phenomena accompanying or underlying migration. Previously, we had shown that in migrating alkali-transformed Madin-Darby canine kidney focus (MDCK-F) cells a Ca(2+)-sensitive 53-pS K+ channel underlies oscillations of the cell membrane potential. The present study def...

We examined the peptide transport activity in renal basolateral membranes. [(14)C]glycylsarcosine (Gly-Sar) uptake in rat renal cortical slices was saturable and inhibited by excess dipeptide and aminocephalosporin cefadroxil. When several renal cell lines were screened for the basolateral peptide transport activity, Madin-Darby canine kidney (MDCK) cells were demonstrated to have the greatest ...

The role of platelet endothelial cell adhesion molecule-1 (PECAM-1) in endothelial cell-cell interactions and its contribution to cadherin-mediated cell adhesion are poorly understood. Such studies have been difficult because all known endothelial cells express PECAM-1. We have used Madin-Darby canine kidney (MDCK) cells as a model system in which to evaluate the role of PECAM-1 isoforms that d...

Ochratoxin A (OTA) is a ubiquitous fungal metabolite with nephritogenic, carcinogenic, and teratogenic action. Epidemiological studies indicate that OTA may be involved in the pathogenesis of different forms of human nephropathies. Previously we have shown that OTA activates extracellular signal-regulated kinases 1 and 2, members of the mitogen-activated protein kinases (MAPK) family, in the C7...

The renal UT-A urea transporters UT-A1, UT-A2, and UT-A3 are known to play an important role in the urinary concentrating mechanism. The control of the cellular localization of UT-A transporters is therefore vital to overall renal function. In the present study, we have investigated the effect of ubiquitination on UT-A plasma membrane expression in Madin-Darby canine kidney (MDCK) cell lines ex...