THY1 and glomerulonephritis: In acute anti-thy1 glomerulonephritis, a rat model of acute, reversible glomerular matrix expansion, it was showed that PDGF receptor tyrosine kinase blockade with STI 571 was associated with significant reductions in mesangial cell proliferation, the number of activated (alpha-smooth muscle positive) mesangial cells, and glomerular type IV collagen deposition.