[Opsoclonus-myoclonus syndrome in children].

To study clinical peculiarities of parainfectious opsoclonus-myoclonus syndrome (OMS) in children and to elaborate approaches to its pharmacotherapeutic correction, 20 children, including 12 girls and 8 boys, have been examined using neurological, neurophysiological, immunological and virological methods along with magnetic resonance tomography (MRT). Age-at-disease-onset was from 8 months to 3 years old. The development of neurological symptoms was related to a virus infection (55% of cases) or vaccination (15%).

[Use of group A-specific polysaccharide antigen conjugated with protein carrier for detection of specific anti-polysaccharide antibodies].

Group-A specific polysaccharide antigen has been obtained by extraction of streptococcal suspension using 4N NaNO2 and glacial acetic acid, conjugated with bovine serum albumin using CNBr. Testing of the preparation with a set of rabbit anti-sera by enzyme immunoassay (EIA) and passive hemagglutination reaction (PHR) revealed its antigenic specificity both in direct experiments and in N-acetyl-D-glucosamine absorption. Forty-seven sera of EIA-studied individuals and 35 sera of PHR-studied ones, all with group-specific polysaccharide antigen, were examined.

[Induction of mutations in Streptomyces antibioticus].

Mutagenic action of UV-light, nitrosoguanidine and nitrosomethylbiuret was studied in Streptomyces antibioticus VNIIA 1607. Nitrosomethylbiuret appeared to be most effective inducer of auxotrophic mutations (mutation frequency reached 15%). By means of hybridological analysis, it was shown that heterokaryons predominated in the progeny of mixed cultures of multiply marked strains.

["Killer" plasmid mutants obtained by exposure to 5-fluorouracil].

Weak killers were tolerated from a killer strain of type k2 of Saccharomyces cerevisiae by treatment with 5-fluorouracil. They segregated sensitive clones during vegetative growth with a frequency from 2 to 20 per cent (nonstable killers, Knst mutants). Alteration of killer activity in these mutants is the result of a mutation in the cytoplasmic killer determinant (KIL-k).

["Killer" plasmid in natural strains of Saccharomyces].

Double stranded RNA's of thirteen wine strains of Saccharomyces belonging to different species and exhibiting killing activity were studied. Two strains of Oxford genetic stocks were used for control. All these strains have four different spectra of killer activity and contain two double stranded RNAs, L and M.