Relation between serum hepatitis C virus-RNA levels and efficacy of interferon-β therapy

We performed two courses of interferon-β (IFN-β) to a child with chronic hepatitis C. A complete response was not obtained by the first interferon treatment, however, the results of the second treatment differed from those of the first. Hepatitis C virus (HCV)-RNA remained negative and both aspartate aminotransferase and alanine aminotransferase levels remained normal after completion of the second course. From these results we estimated that HCV-RNA levels before IFN therapy could be significantly associated with the efficacy of this treatment. The serum level of HCV-RNA was 10⁶ copies/50 μL before the first treatment, but was 10³ copies/50 μL before the second course. We conclude that IFN therapy to children with hepatitis C should always be directed at providing a cure. Even if the clinical effects of the first course are minimal decreasing quantities of HCV-RNA still offer hope for cure by subsequent readministration.     

Primary Adrenocortical Carcinoma and Ganglioneuroblastoma Followed by Rhabdomyosarcoma in a Child: A Case Report

We report a case of a young child affected by triple cancerswho developed a pleomorphic rhabdomyosarcoma of the retroperitoneumfollowing prophylactic chemotherapy after surgery for doubleprimary adrenocortical carcinoma and ganglioneuroblastoma. It is suggested that genetic susceptibility and chemotherapymight be responsible for the development of rhabdomyosarcomaas the second malignant neoplasm.     

Dipeptide synthesis catalyzed by aminoacyl-tRNA synthetases from Bacillus stearothermophilus

A new approach to enzymatic peptide synthesis by using aminoacyl-tRNA synthetase (ARS) as a catalyst has been investigated. Four ARSs (AspRS, HisRS, LeuRS and TyrRS) have been purified from a thermophilic bacterium, Bacillus stearothermophilus. By using TyrRS as a catalyst, tyrosine and leucinamide were shown to be condensed in the presence of ATP to give tyrosylleucinamide. In this manner, all of the ARSs investigated catalyzed the peptide synthesis reactions. TyrRS did not have strict specificity for the amino acid derivatives used as substrates and even D-amino acids were incorporated into peptides fairly easily in this enzymatic reaction. Preparative scale synthesis of L-Tyr-L-LeuNH₂ was carried out and from this the scope and limitation of this new enzymatic reaction as a tool to the peptide synthesis has been described.