The relationship of damage to and death of ascitic tumor cells during starvation to the ATP and free calcium content in the cells

Ascite tumor cells EL-4 were incubated in conditions of energy starvation (Hanks salt solution with rothenone and without glucose) at 37 degrees C for 3 hours. Under these conditions, some structural cell damages appeared within the first hours: enlarging and flattening of the cells, blebbing, vacuolization of the cytoplasm, nuclear chromatin condensation. Later on, a share of cells with obvious damage decreased, whereas that of the cells stained with trypan blue (dead cells) much increased (up to 90% after a 3 hour incubation). The cellular ATP decreased abruptly (up to 10% of the control) during the first 10 minutes of starvation. Free Ca2+ concentration increased within 1 hour of incubation more than two-fold. The conditions promoting Ca2+ influx (ionophore A23187 + Ca2+ in medium) accelerated the damage and cell death. However, the increase in free Ca2+ concentration did not trigger any damage in the energy-starved cells, since in the Ca2(+)-depleted medium (no increase in free Ca2(+)-concentration) the development of damages was not prevented. The damage initiation was irreversible: the addition of glucose to cell suspensions after 0.5-1 hour of their incubation in energy-starved condition did not prevent the development of damage, while ATP content in these cells was much increased.     

RNA-binding properties of the plant protein Nt-4/1

The tobacco α-helical protein Nt-4/1 with unknown function forms ribonucleoprotein (RNP) complexes in vitro. Results obtained by retardation of RNP complexes in agarose gel were confirmed by Western-Northern hybridization. Several deletion and point mutants of Nt-4/1 were constructed, and the RNA-binding site was mapped in a positively charged region of the C-terminal domain of the protein. The results of this study and those described earlier support our hypothesis of the participation of Nt-4/1 protein in spreading RNA-containing pathogens in the plant.     

Investigation of ribosomes using molecular dynamics simulation methods

The ribosome as a complex molecular machine undergoes significant conformational changes while synthesizing a protein molecule. Molecular dynamics simulations have been used as complementary approaches to X-ray crystallography and cryoelectron microscopy, as well as biochemical methods, to answer many questions that modern structural methods leave unsolved. In this review, we demonstrate that all-atom modeling of ribosome molecular dynamics is particularly useful in describing the process of tRNA translocation, atomic details of behavior of nascent peptides, antibiotics, and other small molecules in the ribosomal tunnel, and the putative mechanism of allosteric signal transmission to functional sites of the ribosome.     

A spectrophotometric method of analysis of fusidic acid

A spectrophotometric method for assay of fusidic acid is described. The method is based on reaction with a reagent consisting of acetic anhydride and concentrated sulfuric acid. Mathematical processing of the results of the main substance determination in fusidic acid preparations showed that the error did not exceed 2 per cent. Procedures for spectrophotometric assay of fusidic acid in control of the processes of its biosynthesis, isolation and purification were developed. The procedures provided control of the technological process of fusidic acid production.     

Effects of cerebrocrast on local cerebral circulation and EEG in cats with cerebral hemorrhage]

In experiments on awake cats before and after intracerebral hemorrhage influence of cerebrocrast and nimodipine intravenous infusion (1 microgram/kg-1/min-1 during 60 min) on cerebral blood flow (CBF) in the cortex, thalamus and reticular formation and power of (alpha + beta)-, theta-, and delta-waves was investigated. During cerebrocrast infusion increasing CBF and improving bioelectrical activity were demonstrated.     

Several copies of angiogenin gene are present in the mammalian genome

Human cDNAs coding for angiogenin were isolated from Li7 hepatoma. Analysis of the nucleotide sequences of isolated cDNA clones and its comparison with recently published sequences of cDNA and human angiogenin gene permitted to suggest that an intron is present in the 5' region of the gene, dividing the coding and 5' untranslating regions. The size of the intron exceeds 1700 b.p. Up to now it has been known that the angiogenin gene is a single copy gene. However our results of blot-hybridization with genomic DNA of some mammals showed that there are 2-3 copies of the gene in their genomes. According to our results the angiogenin gene is conserved in mammalian genomes.     

Interrelations of the cerebral hemispheres in the cat in early stages of ontogeny

Multiple recording of transcallosal responses (TCRs) from different cortex areas has been carried out by means of acute experiments with immobilized and anesthetized kittens at the age of 1 to 30 days after birth. Homotopical TCRs in kittens at the age of 2-15 days appear earlier, are presented wider and reveal features of a greater maturity configuration and of amplitudinal-temporal parameters in association zone (parietal and sensorimotor) in comparison with projection zones (somatosensory, visual and auditory). Interhemispheric interrelations in association cortex of kittens are carried out not only by means of callosal but extracallosal system. In the course of animal developing in the parietal cortex the drain of the surface-positive oscillation moves from V to III layer and the drain of the surface-negative deviation remains at the level of II-III layers. The late component is registered up to the depth of III-IV layers, having the drain in I-II layers. In sensorimotor cortex the surface-negative oscillation has the drain in I-II layers, surface-positive--in III and V--VI layers. The interhemispheric asymmetry emerging from the moment of responses appearance is peculiar to TCRs of projection and association zones. In the first month of the postnatal development the asymmetry of positive and negative TCR oscillation amplitude has an individual character in sensorimotor cortex and a specific one--in parietal. The temporal parameters of TCR in association areas of the left hemisphere cortex are significantly shorter than of the right one. The data given testify to the possibility of interhemispheric interrelation realization and the presence of interhemispheric asymmetry in cat's brain on the early stages of postnatal ontogenesis.     

Scaling of the Sense Organs of Insects. 2. Sensilla. Discussion. Conclusion

Entomological Review - The second part of our review systematizes the published evidence of scaling of the insect antennal sensory system and provides an allometric analysis of quantitative data...