Suppressive effect of immature erythroid cells on the B-cell proliferation

Immature erythroid cells suppress the proliferative response of preactivated B lymphocytes to lipopolysaccharide. The same effect is observed when recombinant human interleukin-2 or culture medium conditioned by preactivated T or B cells is added to cultured cells. Suppressive nucleate erythroid cells are resistant to leucine methyl ester. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 1, pp. 66–70, January, 1997     

The universal algorithm of maturation for secretory and excretory protein precursors.

During maturation, most proteins undergo different posttranslational modifications. In most simple cases, signal peptidases remove the signal or leader peptide from the precursors of the secretory proteins during their translocation across the ER membrane. For biologically active proteins, such as enzymes, regulatory and defense proteins, toxins, etc., additional maturation-regulating mechanisms were shown to proceed with limited proteolysis of inactive precursors by specific enzymes. A number of specific enzymes from different cell types selectively cleave proproteins at specific processing sites. In this work, we analyzed the sequences of protein precursors synthesized in the excretory glands of different animals and identified new, non-traditional processing sites. They differ from the motifs previously identified in secreted proteins' precursors and enabled us to reconstruct the sequence of events leading to the conversion of protein precursors into the final products (mature proteins). We also found that in animals, the maturation mechanism of secretory and excretory proteins and the set of enzymes involved are species specific. The processing sites identified in protein precursors in this study are useful for a more detailed genome analysis and more accurate mature protein sequence prediction.     

Investigation of the anti-motion sickness effect of 3-hydroxypyridine derivatives]

Experiments with rats showed that three out of 12 3-hydroxypyridine derivatives (ethyl-methyl hyd- roxypyrine succinate, SK-132 and IBCP-2 - had an anti-motion sickness effect stronger than of scopolamine, the reference vestiboloprotector. The anti-motion sickness effect of ethyl-methyl hydroxypyrine was also demonstrated in experiments with cats. Apparent anti-motion sickness effect of ethyl-methyl hydroxypyrine (mexydol) was found in 69% of healthy male volunteers which is comparable with the effect of scopolamine (62%). In experiments with immobilized cats (myorelaxation drugs) the microelectrode technique and microontoiphoresis of physiologically active substances revealed that ethylmethyl hydroxypyrine influences the majority of neurons in the medial vestibular nucleus (61%). Suppression of cell spontaneous activities in more than one half of cases can be stopped completely or attenuated significantly by bicucculine, a specific GABA(A)-receptor antagonist. In 42% of neurons ethyl-methyl hydroxypyrine subdues the response to vestibular stimulation which is likely to underlie the anti-motion sickness effect.