BioStratum Reports Promising Advances for Treatment of Progressive Kidney Disease
-- Nephrotic syndrome gene identified. Codes for key protein in kidney filtration barrier--
-- Drug candidate Pyridorin™ prevents development of diabetic kidney disease --

Research Triangle Park, N.C., March 20, 1998 -- BioStratum Incorporated today announced that a research team led by its scientific cofounder has identified the gene and its corresponding protein responsible for the kidney disease congenital nephrotic syndrome. More over the results from this discovery provide a promising target for
the development of treatments for proteinuria, a common and serious complication of many kidney diseases.

In related news, the Company also reported that its drug candidate Pyridorin™ prevented the development of kidney disease in a preclinical animal model of diabetes.

The research team headed by BioStratum cofounder professor Karl Tryggvason at the Karolinska Institute
in Stockholm, Sweden, has succeeded in identifying
the mutant gene responsible for congenital nephrotic syndrome, a human kidney disorder characterized by massive leakage of blood proteins into the urine, termed medically as proteinuria.

Congenital nephrotic syndrome is usually fatal in early childhood, and the only available treatment is kidney transplantation. The results provide for the immediate
DNA-based diagnosis of congenital nephrotic syndrome and the identification of individuals that are carriers for
this disease. Researchers from Finland, Sweden and the U.S. contributed to the study titled, "Positionally Cloned Gene for a Novel Glomerular Protein-Nephrin-Is Mutated in Congenital Nephrotic Syndrome" that was published today in Molecular Cell (Volume 1, #4).

The identified gene encodes for a new protein named nephrin. Preliminary work indicates that nephrin is found
at the surface of cells that comprise the blood filtration barrier of the kidney. Its apparent function is to maintain
the integrity of the glomerular epithelials cells, and for their anchorage to components of the glomerular basement membrane involved in blood filtration.

"This discovery provides new fundamental knowledge about the kidney's filtration barrier and, furthermore, provides a new target for the development of treatments for proteinuria. While congenital nephrotic syndrome is relatively rare, proteinuria is a major complication in numerous diseases affecting the kidney, and a principal complication of the many disorders that can lead to end stage renal disease, including diabetic nephropathy," said Professor Tryggvason.

On the drug development front, a BioStratum sponsored study conducted by Dr. John Baynes at the University
of South Carolina, is providing promising results on BioStratum's drug candidate Pyridorin™, a member
of a new class of post-Amadori inhibitors of diabetic complications. The study demonstrates its efficacy
in preventing the development of proteinuria and other
diabetic kidney disease pathologies in a rat model of diabetes. The model used, the streptozotocin (STZ)
animal model, is widely accepted as one of the best available to test the efficacy of drugs for diabetic kidney disease. Pyridorin™ inhibits the formation of advanced glycation end-products (AGEs), which are thought to
be a major contributing factor in the development of
diabetic kidney disease. It specifically blocks conversion
of a key intermediate of AGE formation. Pyridorin™ also exhibits a very favorable toxicity profile in animal studies.

BioStratum is a privately held company developing proprietary therapeutics based on recent scientific advances in basal lamina and related technologies. The company's drug candidates are directed against novel
basal lamina extracellular targets involved in degenerative and invasive disease processes fundamental to kidney disease, diabetes and cancer. The company has also developed methods for the production of recombinant
basal lamina proteins for use in wound repair and
advanced tissue regeneration protocols.