The cause of cancer mutations: Improvable bad life or inevitable stochastic replication errors?

Despite substantial progress in understanding the mechanisms of carcinogenesis and fighting oncology diseases, cancer mortality remains rather high. Therefore, there is a striving to reduce this mortality to the level determined by endogenous biological factors. The review analyzes the mutations that lead to cell malignant transformation and describes the contribution that self-renewal of adult tissues makes to tumorigenesis. Cancer progression is considered as a development of a complicated system where cells mutate, evolve, and are subject to selection. Cancer paradoxes are described in conclusion.     

Detection in the structure of influenza viral proteins of sequences similar to vasoactive intestinal peptide

The paper presents the results on the influenza virus proteins (only HA, M and NS) contained in the amino acid sequence regions similar to that of the VIP. These data may be important as there is similarity in pathological reactions between VIP and influenza virus.     

A functional connection between translation elongation and protein folding at the ribosome exit tunnel in Saccharomyces cerevisiae

Proteostasis needs to be tightly controlled to meet the cellular demand for correctly de novo folded proteins and to avoid protein aggregation. While a coupling between translation rate and co-translational folding, likely involving an interplay between the ribosome and its associated chaperones, clearly appears to exist, the underlying mechanisms and the contribution of ribosomal proteins remain to be explored. The ribosomal protein uL3 contains a long internal loop whose tip region is in close proximity to the ribosomal peptidyl transferase center. Intriguingly, the rpl3[W255C] allele, in which the residue making the closest contact to this catalytic site is mutated, affects diverse aspects of ribosome biogenesis and function. Here, we have uncovered, by performing a synthetic lethal screen with this allele, an unexpected link between translation and the folding of nascent proteins by the ribosome-associated Ssb-RAC chaperone system. Our results reveal that uL3 and Ssb-RAC cooperate to prevent 80S ribosomes from piling up within the 5′ region of mRNAs early on during translation elongation. Together, our study provides compelling in vivo evidence for a functional connection between peptide bond formation at the peptidyl transferase center and chaperone-assisted de novo folding of nascent polypeptides at the solvent-side of the peptide exit tunnel.     

Microcloning and characteristics of DNA from regions of the centromeric heterochromatin of Drosophila melanogaster polytene chromosomes]

A method of microcloning, which involves microsurgical excision of chromosome fragments, DNA amplification by means of a polymerase chain reaction (PCR), and ligation of amplified products with plasmids, was employed in studying Drosophila polytene chromosomes for the first time. Clones of the DNA library thus obtained contained inserts varying in size from 0.1 to 0.5 kb. DNA sequencing of five clones of the library showed that pericentromeric heterochromatin contained the 17.6 and 297 retrotransposons, the ninja retrotransposon characteristic of D. simulans, and two Drosophila repetitive elements, a8 and a12, the function of which remains unknown.     

Computer evaluation of cat brain activation by means of striate cortex ecog

We analyzed striate cortex electrocorticograms of 12 cats in the following states: at rest with eyes closed and with eyes open; after light electrical stimulation of the ears; drowsiness; opening of the eyes after drowsiness; narcotic sleep. Spectral and periodometric analyses of the ECOG revealed state-dependent differences in power spectra from cats in two frequency bands (2.8–5.0 and 13.8–20.8 Hz). It is suggested that the ratio of ECOG power spectra in these frequency bands can be used to evaluate brain activation in cats.Vilnius University, Lithuania. Translated from Neirofiziologiya, Vol. 24, No. 6, pp. 672–678, November–December, 1992.