Cancinogenic effects of fast helium ions with energy of 4 GeV/nucleon in rats

The study was made of carcinogenic efficiency of 4 GeV/nucleon helium ions (LET = 0.88 keV/um) in comparison with gamma-radiation 60Co (LET = 0.23 keV/um). Adult outbred female rats underwent a single whole-body irradiation with helium ions in doses 0.25-4.0 Gy at the Synchrophasotron of the Joint Institute for Nuclear Research and with gamma-rays at "PX-gamma-30" irradiator in doses ranged from 0.5 to 4.0 Gy. The yields, histology and occurrence time of hemoblastoses and tumours in mammary glands, in endocrine glands, in soft tissues and in other organs were determined. Histological study was made using conventional methods. The irradiation of experimental animals with accelerated helium ions and standard radiation was shown to result in an increase in the yield of growths of various localizations with decreasing occurrence time and expanding histological spectrum as compared with intact rats. However, helium ions possess a higher carcinogenic efficiency. The coefficients of relative biological effectiveness of helium ions calculated by the nonparametric method appeared to increase with decreasing the radiation dose.     

Evidence for Shared Cognitive Processing of Pitch in Music and Language

Language and music epitomize the complex representational and computational capacities of the human mind. Strikingly similar in their structural and expressive features, a longstanding question is whether the perceptual and cognitive mechanisms underlying these abilities are shared or distinct – either from each other or from other mental processes. One prominent feature shared between language and music is signal encoding using pitch, conveying pragmatics and semantics in language and melody in music. We investigated how pitch processing is shared between language and music by measuring consistency in individual differences in pitch perception across language, music, and three control conditions intended to assess basic sensory and domain-general cognitive processes. Individuals’ pitch perception abilities in language and music were most strongly related, even after accounting for performance in all control conditions. These results provide behavioral evidence, based on patterns of individual differences, that is consistent with the hypothesis that cognitive mechanisms for pitch processing may be shared between language and music.     

Characteristics of the carcinogenic effectiveness of 645 MeV protons and 60Co gamma-irradiation

The carcinogenic effect of 645 MeV protons and 60Co-gamma-rays (1, 2 and 4 Gy) on mongrel female rats was comparatively studied. The observations were made throughout the entire life span of the exposed animals. Revealed were a similar biological effectiveness of the two types of radiation and a common nature of the carcinogenic transformations.     

Properties of Large-Conductance Cationic Channels in the Neuronal Nuclear Envelope

The genetic apparatus of the nucleus of eukaryotic cells is surrounded by the nuclear envelope containing ion channels with different biophysical properties. The channels responsible for calcium release from the nuclear envelope into the intranuclear space have attracted special attention. As we found, a great number of large-conductance ion channels selective with respect to monovalent cations and impermeable for bivalent cations are present in all membranes where inositol trisphosphate receptors are expressed. We showed that channels of this type are insensitive to blockers of potassium channels and, according to their properties, cannot be attributed to one well-known type of ion channels or another. In addition, since their blockers remain unknown, these channels at present cannot be isolated and cloned. Channels of this type deserve further investigation; we hypothesize that large-conductance cationic channels can be involved in the control of the duration of Ca²⁺ release from the calcium store.     

Clinical and quality of life responses to high-dose chemotherapy plus autologous stem cell transplantation in patients with multiple sclerosis: two case reports

During the last several years high-dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT) has been established as a therapeutic option for multiple sclerosis (MS) patients. We report on the long-term effects of HDCT + ASCT in two female patients affected by secondary progressive and relapsing-remitting types of MS, respectively. As a result, disease stabilization was achieved in the first case and disease improvement in the second one. Both patients were off immunosuppressive or immunomodulating therapy throughout the post-transplant period. Notably, HDCT + ASCT resulted in an excellent quality of life (QoL) response in both cases. Our findings demonstrate that HDCT + ASCT could be considered as an effective treatment for MS patients. Moreover, QoL measurement seems to be an effective approach to assessment of treatment outcomes at long-term follow-up of patients with MS.     

Diversity of genes encoding nonribosomal peptide synthetases in the <Emphasis Type="Italic">Streptomyces sioyaensis</Emphasis> genome

Streptomyces sioyaensis Lv81 produces siomycin, a thiopeptide antibiotic synthesized on ribosomes. Nothing is known about the ability of this strain to produce nonribosomal peptides, a well represented group of natural actinomycete compounds. Using degenerate primers, we cloned a number of DNA fragments encoding putative adenylation domains (A domains) of nonribisomal peptide synthetases involved in biosynthesis of unknown compounds. Sequencing of amplicons revealed nine different A domains, which were analyzed in more detail. Nonribosomal codes of these domains were determined, but in most cases their substrate specificity failed to be unambiguously predicted. This means that many of these domains can recognize novel amino acids and be used to improve and expand the bioinformatic toolbox applied to predict substrate specificity of A domains. Multiple sequence alingments showed that the cloned A domains are probably involved in different biosynthetic pathways. Five A domains were used in gene inactivation experiments. Inactivation of one of them (in strain 736) resulted in a decrease of the total antibiotic activity as compared to the initial strain. Other A-domain mutants were similar to the initial strain in morphology and siomycin production. The causes of reduced antibiotic activity of strain 736 are discussed.     

Properties of <Emphasis Type="Italic">lanK</Emphasis>-based regulatory circuit involved in landomycin biosynthesis in <Emphasis Type="Italic">Streptomyces cyanogenus</Emphasis> S136

LanK is TetR-like regulatory protein recently shown to regulate the export and glycosylation of landomycins in Streptomyces cyanogenus S136. Here, several properties of the lanK-mediatcd regulation were deciphered. LanK seems to function as oligomer as evident from experiments in vitro. In vivo, it is able to recognize various landomycins with altered aglycon structure and the minimal concentration of landomycin A sensed by LanK lies in low nanomolar range. Coexpression studies showed that the positive regulatory gene lanI upregulates lanK-dependent lan genes once the negative LanK-regulation is cancelled. Gene lanK can be useful for the construction of biosensor strains for sensitive and specific identification of producers of landomycin-like molecules with long glycosidic chains.