Multimodality treatment for retinoblastoma in children

A comprehensive programme was developed for the treatment of uni- and bilateral retinoblastoma in children with due regard to the disease stage by the TNM system. The use of the current sources of teletherapy and cyclic polychemotherapy expanded indications for organ-saving therapy at most common stages. Treatment by the program was performed in 202 patients, including 125 children with unilateral damage and 77 with bilateral damage. An attempt made treat 140 (75%) children at the first stage. More than 70% of cases were diagnosed as having disease stage T3 in one or two stage, while such patients underwent ocular enucleation. A complete or partial (more than 50%) tumor regression without signs of its progression for 2 years or more was achieved in 62% of cases. At the first stage of therapy, conservative therapy insignificantly affected the children's longevity in uncomplicated cases, which is particularly important in bilateral involvement, while this preserved the organ of vision in more than half the patients (62%). Five-year survival was 92 and 82% in unilateral retinoblastoma surgically treated and untreated, 83 and 84%, respectively. Adequate multimodality treatment brought about low incidence rates of recurrence and metastasis (10%) in conservative therapy and 7.7% among all patients.     

Extraction of U(IV) and U(VI) with 30% Tributyl Phosphate under Conditions of Formation of the Second Organic Phase

Extraction of U(IV) and U(VI) from nitric acid solutions with 30% TBP in dodecane under conditions of formation of two organic phases was studied. With respect to uranium recovery, this extraction system substantially differs from the similar system with 30% TBP in hexachlorbutadiene in which only one organic phase is formed. The study of the electronic spectra showed that the U(IV) and U(VI) solvates formed in light and heavy organic phases are different.     

Effect of TBP on Extraction of REE and TPE with 4d Element Salts of Dibutylphosphoric Acid

Extraction properties of 4d element (Ti, Zr, and Hf) salts of dibutylphosphoric acid (HDBP) are examined. In extraction of Eu from nitric acid solutions, the optimal [HDBP]/[M] ratio depends on the presence of TBP and a diluent in the extraction system and also on the HNO₃ concentration in solutions. With decane used as a diluent instead of xylene, the distribution coefficients of the extracted elements increase, and the extracting properties of the Zr and Hf salts become more similar. The extraction characteristics of these salts are similar over the entire examined range of HNO₃ concentrations. At the same time, the difference between the Zr and Hf salts in the extractive power applies to all the lanthanides. The extraction properties of the Ti salt strongly differ from those of the Zr and Hf salts. Thorough study of the behavior of the Ti salt is complicated by its limited solubility in organic solvents.     

Preliminary results of treatment of solid tumors in children with non-standard radiotherapy]

Urinary excretion of mefenamic acid (MA) and its two oxidative metabolites, M-I (3'-hydroxymethyl derivative) and M-II (3'-carboxyl derivative), and their glucuronides was investigated in preterm infants undergoing MA therapy. MA was given orally at a dose of 2 mg/kg and the dose was repeated every 24 h a maximum of three times. Urine was collected for up to 5 d after the last dose, and MA and the metabolites were determined by a newly developed HPLC. The cumulative amounts of MA and the metabolites excreted in the urine varied from 7 to 46% of the total dose administered, and were less than those reported in adults and children. Significant correlation was observed between the plasma half-life of MA and the cumulative amount of MA and the metabolites excreted in the urine. These results suggest that long plasma half-lives of MA observed in preterm infants are due mainly to low activity of drug metabolizing enzyme(s). In an infant who received the two regimens of MA therapy about 2 weeks apart, the plasma half-life of MA was shortened and the urinary excretion of the MA metabolites including their glucuronides was greatly increased during this period. It is suggested that the activities of both cytochrome P-450(s) and glucuronyltransferase(s) related to MA metabolism rapidly increased during the first month of the infant's life.     

Extraction Properties of Dibutylphosphoric Acid Zirconium Salt in Recovery of Transplutonium and Rare-Earth Elements from Nitric Acid Solution

The structures of dibutylphosphoric acid zirconium salt (Zr-DBP) and of the complexes formed in the organic phase in extraction of rare-earth elements with Zr-DBP were suggested on the basis of the extraction and IR data. The influence exerted by the acidity, Zr-DBP concentraiton, and degree of extractant saturation with the metal on the structure of the complexes was examined. The contributions of various extraction mechanisms for all the rare-earth elements and also for Am and Cm were revealed by mathematical simulation. Irrespective of the diluent, addition of TBP to Zr-DBP decreases the distribution factors of Ce, Eu, and Am but increases the extractant capacity for rare-earth elements by a value that considerably exceeds the extraction of the elements with TBP taken separately.