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Biomedical subjects

H P Schwartz

Publications and source records attributed to H P Schwartz.

2 recordsLinked to original sources

Minimum safety requirements for preclinical testing.

A wide range of biological products for medicinal use can now be produced by novel biotechnology processes. These products include naturally occurring human proteins and peptides such as hormones, cytokines, blood products as well as monoclonal antibodies of murine and human origin and bacterial and viral antigens for use as vaccines. However, there are potential safety concerns that arise from the novel processes used in their manufacture and from the complex structural and biological characteristics of the products. The acute and repeated dose toxicity testing, pharmacodynamic and immunological testing and a range of product-specific biochemical and safety tests required for these products are described.

Animals↗

Thiamine response in maple syrup urine disease.

We measured the biochemical response for four patients with maple syrup disease to pharmacologic doses of thiamine, and correlated their response to their branched chain alpha-ketoacid dehydrogenase activity. We observed a linear correlation between the concentrations of each plasma branched-chain amino acid and its corresponding ketoacid analogue. In addition, the renal tubular reabsorption of branched-chain amino and ketoacids was nearly complete within these physiologic concentrations. Three children responded to thiamine therapy with a reduction in concentration of plasma and urinary branched-chain amino and ketoacids. Each responder had at least 5% activity for branched chain alpha-ketoacid dehydrogenase in their mononuclear blood cells and in whole cell fibroblasts from cultured skin when compared to the activity in normal control cells. We propose that each child with maple syrup urine disease be assessed for their response to thiamine by quantifying the concentration of branched-chain amino acids in plasma before and after vitamin supplementation.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗