Current X-ray diagnosis of stomach cancer (comparison of radiologic and morphological methods of investigation)

By using the principles of wide comparisons of the data of radiation diagnosis (routine X-ray study, ultrasonography (USG), CT, MRI) with the morphological findings of resected gastric specimens from patients with endophytic gastric cancer (EGC) (n = 85), the authors propose some points in the problem associated with its diagnosis. They believe that by taking into account the fact that there is an obvious growth of endophytic parietally growing gastric cancer with the concurrent reduction in its intestinal forms, it is necessary to restore current radiation to its leading place, along with endoscopy, in detecting the cancer. The authors makes a highly positive assessment of USG, CT, MRI in addition to routine X-ray study and endoscopy particularly in those cases when difficulties emerge in histological verification of the existing signs of parietally growing cancer. The paper makes indications for USG, CT, MRI concrete. The authors also show how to stage gastric cancer.     

Modulating role of lipids and their fatty acids in adaptation of the White Sea mussels <Emphasis Type="Italic">Mytilus edulis</Emphasis> L. to environmental salinity change

Role of lipids and fatty acids (FA) in littoral and sublittoral White Sea mussels Mytilus edulis L. was studied at various stages of reproductive cycle in the phenotypic adaptation (acclimation) to changes of the sea water salinity. The obtained data indicate differences in the mussel lipid and fatty acid spectra, which are connected both with their location (littoral or sublittoral) and with the spawning period stage (3b—release of gametes or 3c—resorption of residual sex products). Lipids and FA of both mussel groups respond to the salinity changes to the greater degree at the 3b than at the 3c stage. In the littoral mussels at the 3b and 3c stages there were revealed differently directed changes in the content of membrane lipid—cholesterol—and in the cholesterol: phospholipids ratio. In the sublittoral mussels that are less adapted to extreme action of abiotic factors, more significant changes were found in the lipid and FA compositions.     

Evolution from retrotransposons to retroviruses: origin of the env gene

In genome of Drosophila melanogaster, various families of retrotransposons with different combination of functional domens and mechanisms of transposition are present. However only retrotransposons of gypsy family are retroviruses related to errantiviruses. Other families seemingly appeared as intermediate forms of retroviruses evolution. Despite the fact that the question on origin of retroviruses remains unclear, now the hypothesis of their origin from retrotransoposons can be considered the most consistent. Infectious properties of errantiviruses are linked to the presence of the third open reading frame (the env gene). Acquisition of the env gene conversed retrotransposons into retroviruses. So, origin of this gene is of special interest. Homologues of the env gene of errantiviruses are discovered in genomes of D. melanogaster, as well as in baculoviruses and in bacteria Wolbachia pipientis, the endosymbiont of Drosophila. It was shown that homologue of the env gene come to Wolbachia genome from Drosophila genome by horizontal transfer of the gypsy group retrotransposon. Thus, Wolbachia was not a donor of the env gene for errantiviruses. Seemingly, errantiviruses captured the baculoviral homologue of the env gene (f). However origin of the f gene is not clear. At the same time the env gene homologue in D. melanogaster genome exist (Iris). It must not be ruled out that the Iris gene was the source of the env gene of errantiviruses and baculoviruses.     

Lipid status and feeding habits of salmonid juveniles in the year preceding seaward migration as factors controlling their future smoltification

Juveniles of coho salmon Oncorhynchus kisutch (Walb.) and mykiss Parasalmo mykiss (Walbaum) of the same age (1+) become differentiated as early as eight months before smoltification and seaward migration by their lipid level, feeding habits, and size and weight parameters. It is found that juveniles of coho salmon and mykiss with a high lipid status have a greater (on average) length and weight and consume more calorific food items. The juveniles with a lower lipid status have a lower length and weight and consume less calorific organisms. It is presumed that a considerable part of juveniles with a high lipid status will migrate seaward next year. The role of the trophic factor in development of this differentiation and, accordingly, in determination of smoltification dates is discussed.     

Evolution of errantiviruses of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>. Strategy 2: From retroviruses to retrotransposons

Drosophila melanogaster retrotransposons of the gypsy group are considered to be potential errantiviruses. Their infectivity is caused by the functional activity of the third open reading frame (ORF3) encoding the Env protein, which was probably captured from baculoviruses. Mobile genetic elements (MGEs) of the gypsy group can be conventionally divided into three subgroups: with three ORFs, with a defective ORF3, and without the ORF3. To establish the patterns of evolution of gypsy retrotransposons in D. melanogaster, the members of the three subgroups were examined. Structural analysis of retrotransposons opus and rover, which carry a defective ORF3, as well as retrotransposons Burdock, McClintock, qbert, and HMS-Beagle, which lack the ORF3, suggests that the evolution of these MGEs followed the pattern of loosing the ORF3. At the same time, an MGE of the same subgroup, Transpac, may be an ancestral form, which had acquired the env gene and gave rise to the first errantiviruses. The capture of the ORF3 by retrotransposons provided their conversion to a fundamentally new state. However, the ORF3 in the genome is not subjected to strong selective pressure, because it is not essential for intragenomic transpositions. Because of this, the process of its gradual loss seems quite natural.     

Comparative Analysis of the Fatty Acid Profiles of Smolts of the Brown Trout <Emphasis Type="Italic">Salmo trutta</Emphasis> L. and Atlantic Salmon <Emphasis Type="Italic">Salmo salar</Emphasis> L. during Smoltification (Indera River,White Sea Basin)

The fatty acid status of the total lipids was studied in smolts of the brown trout and the Atlantic salmon collected in summer in the Indera River (White Sea basin). Higher 18:3ω-3/18:2ω-6, ω-3/ω-6, and 20:4ω-6/18:2ω-6 ratios were found in smolts of the Atlantic salmon in comparison to smolts of the brown trout. A higher amount of essential fatty acid 18:2ω-6 and an increased ratio of the sum of polyunsaturated fatty acids to the sum of saturated fatty acids in smolts of brown trout were observed. We have registered the differences in the ratios of the fatty acids, including physiologically active ones, which indicated species-specific physiological and biochemical processes during smoltification.     

Age dynamics of lipid status of juveniles of atlantic Salmon (<Emphasis Type="Italic">Salmo salar</Emphasis> L.) from the Varzuga River

Heterogeneity of zero class (0+) of Atlantic Salmon Salmo salar from the compared biotopes of the Varzuga R. (the Kola Peninsula) is revealed by the content of TAG, PL, 18:2n-6,18:3n-3, the sum of monoenoic FA, and parameters of CS/PL and TAG/PL retained in elder age groups of parr (1+ and 2+). It depends on the quality of food resources and hydrological conditions. The increase in the level of PS, one of the principal regulators of activity of Na⁺/K⁺-ATPase—a key enzyme of osmoregulation—in parrs 1+ and, to a greater extent, in smolts is supposed to be the formation of one of the biochemical mechanisms of preadaptation of fish to a marine environment. Salmon juveniles 3+ differ from the fish of junior age groups in a higher content of PUFA (20:4n-6, 20:5n-3, 22:6n-3), a considerable decrease in TAG, in parameter TAG/PL, and the sum of monoenoic FA related to smoltification and preparation for life in a marine environment. Multidirectional variations of concentrations of minor phospholipids (PI, LPC, SPM) in salmon juveniles depending on age and habitat may indicate the change in viscosity of biomembranes and, accordingly, of activity of some enzymes bound with membranes.