Numerous cell targets for gastrin in the guinea pig stomach revealed by gastrin/CCKB receptor localization

The localization of the gastrin/CCK_B receptor (GR) has recently become a subject of debate, especially since the publication of evidence for its presence in an unsuspected location, namely in the lamina propria, the submucosal layer of the stomach lining. Knowledge of the receptor localization is important because of the critical role of gastrin secretion and its trophic effects on the gastric epithelium. The present study, which utilizes immunohistochemistry and electron microscopy as primary tools, provides unequivocal data concerning the localization of GR in the guinea pig stomach. GR is expressed in parietal cells, on chief cells, and in previously unreported endocrine cells of the stomach. It is not found in the lamina propria. The predominant localization of the receptor in the endocrine cells is on the membranes of cytoplasmic electron-dense secretory granules. The positioning of these cells in the gastric glands suggests that they may be involved in the uptake of gastrin from the circulation. The distribution of GR implies that it may be involved in the regulation of various processes and may mediate various effects of gastrin in the stomach.     

Labelling of lupine nodule metabolites with 14CO2 assimilated from the leaves

On feeding ¹⁴CO₂ to the shoots of lupine (25 mCi per plant) 30 min was the minimal time needed to determine the incorporation of label into bacteroid compounds. The predominant incorporation, exhibited in all root, nodule and bacteroid samples after 30 min exposure, was into sucrose (45–90% of the corresponding fraction radioactivity) of the neutral fraction; into malate (30–40%) of the acid fraction; into aspartic acid and asparagine (60–80% in sum) of the basic fraction. The composition of carbon compounds containing the greatest amount of ¹⁴C in the cytosol of nodules and in bacteroids was similar. Their radioactivity after 30 min exposure was for bacteroids (nCi per g of bacteroid fr. wt): sucrose 5.73, glucose 1.00, malate 0.15, succinate 0.11; for the nodule cytosol (nCi per g of nodule fr. wt): sucrose 200.00, glucose 8.40, malate 9.34, succinate 8.50. Thus it was demonstrated that in lupine, sucrose is the main photoassimilate entering not only into nodules but also into bacteroids. The biosynthesis of aspartic acid and asparagine occurs during nitrogen fixation in bacteroids.     

The features of auditory passive perception while listening to sounds in healthy persons of young or advanced age (event-related potentials and psychology test analysis)

The study analyzed auditory event-related potentials (ERPs) in 37 healthy right-handed subjects without any neurological or psychiatric disorders. Young age group consisted of 18 persons aged from 10 to 27; advanced age group included 19 persons aged from 32 to 59 years. ERPs were recorded from 32 scalp electrodes according to 10–20 System. Two-tones oddball paradigm including standard and target tones was used for ERP-recording. The sound sequence was given to examinees without any preliminary instruction. Complex psychology testing included Stroop Color and Word Test and Wisconsin Card Sorting Test. Significantly larger amplitude of N200 was detected in young subjects compared to advanced age ones. Wavelet-analysis revealed stronger wavelet-connections in the frontal–central area on the time range of P300 in in advanced age examinees vs. young ones. The correlation of the data of psychological tests examining the executive functions was detected with latency of P300 in young examinees and with amplitude of P300 in advanced age ones. Obtained data suggest that switching from one activity to another is prevalent in young persons and focusing on a current activity in advances age persons.     

Preparative method for obtaining recombinant human interferon α2b from inclusion bodies of <Emphasis Type="Italic">Escherichia coli</Emphasis>

A simple, easily reproducible, and scalable method for obtaining recombinant human interferon α2b from Escherichia coli inclusion bodies has been elaborated. It involves the following steps: preparation of producer cell biomass, isolation and washing of inclusion bodies, their dissolution with protein refolding, SP Sepharose chromatography, and DEAE Sepharose chromatography. According to the results of gel electrophoresis and reversed-phase HPLC, the purity of the protein obtained exceeds 95%.     

Synthesis and breakdown of poly-beta-hydroxybutyric acid in Rhizobium lupini]

The effect of various substrates on synthesis and decomposition of poly-beta-hydroxybutyric acid (PHBA) was studied in cell suspensions of the effective strain of Rhizobium lupini and in suspensions of the bacteroids of this strain which were isolated from lupine nodules at different growth stages of the plants. Glucose and beta-hydroxybutyrate were found to be the best substrates for synthesis of PHBA in all variants. The content of PHBA in the presence of these substrates increased in suspensions by 2.0 to 2.5 times during ten hours of incubation. In the presence of succinate, PHBA was actively synthesized only by the bacteroids isolated during the stage of active nitrogen fixation (flowering of the plants). In the absence of exogenous substrates, PHBA was decomposed, especially if ammonium ions were present in suspensions. No synthesis of PHBA was registered in the presence of ammonium and glucose, and the rate of PHBA decomposition was high in this case during the stage of active nitrogen fixation.     

The morphological and functional characteristics of the human aortic endothelium. I. 2 variants of the organization of the endothelial monolayer in atherosclerosis]

The en face organization of human aortic endothelium in zones of low (LP) and high (HP) probability of sudanophilia was examined in preparation impregnated with silver nitrate. It is found that the heterogeneity of endothelial cells (EC) by area is "random" or "clusterized". In the latter case the major part of small and medium-sized EC (less than 800 microns 2) is associated in distinct groups ("clusters") and form foci with high monolayer density. The luminal surface outside the clusters was formed by preferentially large and giant EC. Clusterized endothelium was found with statistically significant higher frequency in HP zones of both "normal" and "atherosclerotic" vessels. The maximum clusterization of EC was revealed on the shoulder region and on the periphery of atherosclerotic plaques which was speculated to be a growth zone of the lesion. It is suggested that the appearance of clusterized endothelium is associated with the active development of atherosclerosis.     

Development of Male Reproductive Organs in an Insertion Mutant TPD1 of Tobacco Characterized by Extended Flowering

A tobacco clone TPD1 (Tobacco Pollen Development), characterized by an extended flowering period, was obtained using a serial agrobacterial transformation of tobacco (Nicotiana tabacum L., cv. Samsun) by constructing a DNA carrying the kanamycin resistance gene inserted into the binary pBin19 vector. However, the characteristics of the vegetative growth of these plants were similar to those of other tobacco clones and the wild type. In the insertion mutant, pollen was 1.5 times smaller than in the wild type and germinated on the stigmata of neither its own clone nor the wild-type plants. Cytochemical investigation of pollen of the TPD1-mutant did not reveal any activity of respiratory enzymes, succinate dehydrogenase and peroxidase, indicating that the pollen was nonviable. Unlike the wild type, theTPD1 mutant exhibited disturbed trophic interactions within the anther tissues, particularly suppressed starch hydrolysis in the anther wall tissues at the stage of rapidly growing microspores. We conclude that the insertion of T-DNA into the TPD1 gene produced structural and metabolic changes during the development of anther tissues in the mutant clone, resulting in pollen sterility.