Hydroxyurea, an antineoplastic agent , inhibits DNA synthesis and cell proliferation without affecting RNA and protein synthesis (Gale, 1964; Young and Hodas, 19641 Yarbro et al -0' 1965 Rosenbranz and Levy, 1965). A variety of evidence, primarily in vivo, has accumulated which suggests that the mode of action of hydroxyurea is the inhibition of the conversion of ribonucleotides to deoxyribonuc...

The introduction of hydroxyurea as a potentially useful agent in leukemia chemotherapy (e.g., Ref. 21) has led to several studies of its effects at the cellular level. Mohler (8) found that this drug both inhibits division and causes death of Chinese hamster cells and that it inhibits division of HeLa S3 cells as well. Young and Hodas (24) reported that synthesis of DNA in HeLa cells is inhibit...

BACKGROUND AND AIMS To introduce the possible role of hydroxyurea (HU), a well-characterized antineoplastic drug with established antiviral effects, in the treatment of chronic hepatitis B. METHODS Four antiretroviral-naïve patients with chronic hepatitis B were enrolled in this limited pilot trial, and given 1000 mg/day of hydroxyurea for 4 weeks; then, the administration of the drug was sus...

The purpose of this investigation was to obtain a com parative measure of DMA repair synthesis in hormonedependent normal mammary tissue and hormone-inde pendent D hyperplastic alveolar nodule (HAN) outgrowth. Treatment of mammary fragments in culture with 5 mm hydroxyurea inhibits 98% of the semiconservative DNA synthesis. Treatment of mammary fragments with methyl methanesulfonate in the pres...

PURPOSE The blood-brain tumor barrier (BTB) significantly limits the delivery of chemotherapeutics to brain tumors. Nitric oxide (NO) is involved in the regulation of cerebral vascular permeability. We investigated the effects of NO donors, L-arginine and hydroxyurea, on BTB permeability in 9L gliosarcoma-bearing Fischer rats. EXPERIMENTAL DESIGN The rats implanted with 9L gliosarcoma were do...

Ribonuclease Sa (RNase Sa) is a secretory ribonuclease from Streptomyces aureofaciens. Herein, 3'-N-hydroxyurea-3'-deoxythymidine 5'-phosphate is shown to be a competitive inhibitor of catalysis by RNase Sa. Inhibition is enhanced by nearly 10-fold in the presence of Zn(2+), which could coordinate to the N-hydroxyurea group along with enzymic residues. The carboxylate of Glu54 is the putative b...

BACKGROUND Fetal hemoglobin level is a heritable complex trait that strongly correlates swith the clinical severity of sickle cell disease. Only few genetic loci have been identified as robustly associated with fetal hemoglobin in patients with sickle cell disease, primarily adults. The sole approved pharmacologic therapy for this disease is hydroxyurea, with effects largely attributable to ind...