Increase of seizure threshold and resistance to stress in rats after immunization against fragment of diazepam-binding inhibitor]

White rats were immunized against fragment of diazepam-binding inhibitor octadecaneuropeptide (ODN) with conjugate ODN bovine serum albumin. This rats have reduced reactions of fear and anxiety in stress model of "open field" and in conflict Vogel test; their pain sensitivity ("tail flick" test) was lowered. The number and intensity of generalized seizure reactions after injection of pentylenetetrazole were decreased. The results show that active immunization to endogenous ODN has stress--protective and anti-seizure effects.     

Changes in direct current input resistance in horizontal cells of fish retina during excitation

The input resistance of pike retinal horizontal cells was measured by means of coaxial electrodes under various conditions of illumination. With moderate intensities of illumination, the resistance (determined from a potential drop caused by the current passed through the microelectrode) increases, whereas at high saturating intensities it decreases, as compared with its value in darkness. Such changes in resistance of the horizontal cells explain the effects of input signals interaction in these cells, such as enhancement and complete saturation, observed earlier. Some properties of the horizontal cell response permit us to assume that the "active" cell response to polarization makes a substantial contribution to the measured resistance of these cells. Possible mechanisms of such changes in input resistance of horizontal cells are discussed.Institute of Problems in Information Transmission, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 3, No. 2, pp. 210–216, March–April, 1971.     

Cladistic analysis of the Cirripedia Thoracica

We present a cladistic analysis of the Cirripedia Thoracica using morphological characters and the Acrothoracica and Ascothoracida as outgroups. The list of characters comprised 32 shell and soft body features. The operational taxonomic units (OTUs) comprised 26 well-studied fossil and extant taxa, principally genera, since uncertainty about monophyly exists for most higher ranking taxonomic units. Parsimony analyses using PAUP 3.1.1 and Hennig86 produced 189 trees of assured minimal length. We also examined character evolution in the consensus trees using MacClade and Clados. The monophyly of the Balanomorpha and the Verrucomorpha sensu stricto is confirmed, and all trees featured a sister group relationship between the ‘living fossil Neoverruca and me Brachylepadomorpha. In the consensus trees the sequential progression of ‘pedunculate‘sister groups up to a node containing Neolepas also conforms to current views, but certain well-established taxa based solely on plesiomorphies stand out as paraphyletic, such as Pedunculata (= Lepadomorpha); Eolepadinae, Scalpellomorpha and Chthamaloidea. The 189 trees differed principally in the position of shell-less pedunculates, Neoverruca, the scalpelloid Capitulum, and the interrelationships within the Balanomorpha, although the 50% majority rule consensus tree almost fully resolved the latter. A monophyletic Sessilia comprising both Verrucomorpha and Balanomorpha appeared among the shortest trees, but not in the consensus. A tree with a monophyletic Verrucomorpha including Neoverruca had a tree length two steps longer than the consensus trees. Deletion of all extinct OTUs produced a radically different tree, which highlights the importance of fossils in estimating cirripede phylogeny. Mapping of our character set onto a manually constructed cladogram reflecting die most recent scenario of cirripede evolution resulted in a tree length five steps longer than any of our shortest trees. Our analysis reveals that several key questions in cirripede phylogeny remain unsolved, notably the position of shell-less forms and the transition from ‘pedunculate‘to ‘sessile‘barnacles. The inclusion of more fossil species at this point in our understanding of cirripede phylogeny will only result in even greater levels of uncertainty. When constructing the character list we also identified numerous uncertainties in the homology of traits commonly used in discussing cirripede evolution. Our study highlights larval ultrastructure, detailed studies of early ontogeny, and molecular data as the most promising areas for future research.     

Concomitant loss of cell surface fibronectin and laminin from transformed rat kidney cells

Both fibronectin and laminin were found by immunofluorescence as a matrix at the surface of normal rat kidney cells. These matrices were absent from the surface of virally transformed rat kidney cells. Soluble fibronectin and laminin were detected in the culture media of the transformed as well as the normal cells. Culture supernates of the transformed cells contained even more fibronectin than the supernates of the transformed cells contained even more fibronectin than the supernates of the normal cells while laminin was present in similar amounts in both culture media. This shows that the loss of fibronectin and laminin from the surface of the transformed cells is caused by failure of the cells to deposit these proteins into an insoluble matrix and not caused by inadequate production. Fibronectins isolated from culture media of the normal and transformed cells were similar in SDS polyacrylamide gel electrophresis. Laminin isolated from culture media by affinity chromatography on heparin-Sepharose followed by immunoprecipitation was composed of three main polypeptides, one with a molecular weight of 400,000 and two with a molecular weight close to 200,000 in both cell types. Fibronectins from both cell types were equally active in promoting cell attachment. Rat fibronectin from transformed cells, like normal cells, when applied to culture dishes coated with fibronectin, readily attached and spread on the substratum, requiring approximately the same amount of fibronectin as the normal cells. On the basis of these results it seem that the failure of the transformed cells to incorporate fibronectin into an insoluble cell surface matix is not a consequence of a demonstrable change in the functional characteristics of the fibronectin molecule or in the ability of the cells to interact with fibronectin. It may depend on as yet unidentified interactions of the cell surface. Similar interactions may be needed for the deposition of laminin into the matrix, because laminin was also absent from the surface of transformed cells, despite its being synthesized by these cells.     

Dissociation of intracellular lysosomal rupture from the cell death caused by silica

The relationship between intracellular lysosomal rupture and cell death caused by silica was studied in P388d(1) macrophages. After 3 h of exposure to 150 μg silica in medium containing 1.8 mM Ca(2+), 60 percent of the cells were unable to exclude trypan blue. In the absence of extracellular Ca(2+), however, all of the cells remained viable. Phagocytosis of silica particles occurred to the same extent in the presence or absence of Ca(2+). The percentage of P388D(1) cells killed by silica depended on the dose and the concentration of Ca(2+) in the medium. Intracellular lyosomal rupture after exposure to silica was measured by acridine orange fluorescence or histochemical assay of horseradish peroxidase. With either assay, 60 percent of the cells exposed to 150 μg silica for 3 h in the presence of Ca(2+) showed intracellular lysosomal rupture, was not associated with measureable degradation of total DNA, RNA, protein, or phospholipids or accelerated turnover of exogenous horseradish peroxidase. Pretreatment with promethazine (20 μg/ml) protected 80 percent of P388D(1) macrophages against silica toxicity although lysosomal rupture occurred in 60-70 percent of the cells. Intracellular lysosomal rupture was prevented in 80 percent of the cells by pretreatment with indomethacin (5 x 10(-5)M), yet 40-50 percent of the cells died after 3 h of exposure to 150 μg silica in 1.8 mM extracellular Ca(2+). The calcium ionophore A23187 also caused intracellular lysosomal rupture in 90-98 percent of the cells treated for 1 h in either the presence or absence of extracellular Ca(2+). With the addition of 1.8 mM Ca(2+), 80 percent of the cells was killed after 3 h, whereas all of the cells remained viable in the absence of Ca(2+). These experiments suggest that intracellular lysosomal rupture is not causally related to the cell death cause by silica or {"type":"entrez-nucleotide","attrs":{"text":"A23187","term_id":"833253","term_text":"A23187"}}A23187. Cell death is dependent on extracellular Ca(2+) and may be mediated by an influx of these ions across the plasma membrane permeability barrier damaged directly by exposure to these toxins.     

Association between 242C>T polymorphism of NADPH oxidase p22phox gene (CYBA) and longevity in Russian population

Life span depends on many factors, including the level of reactive oxygen species, like superoxide radical. Superoxide radical is produced from oxygen in the course of the oxidation of NADPH to NADP⁺. The process is catalyzed by NADPH oxidase. In this study, genotype and allele distributions of the C242T (rs4673) polymorphism in the CYBA gene, which encodes the α subunit of NADPH oxidase (p22phox), were examined in the sample of long livers and in the population sample of the city of Tomsk. Statistically significantly higher frequency of T allele among female long livers (34.625%), compared to the females from Russian population (26.32%) was demonstrated (χ² = 5.226; p = 0.022; OR = 1.48). Thus, the T allele is associated with a high life expectancy in females from the Russian population. No such association was observed for males from the same population.     

Low-voltage underwater electric discharges: Physical properties and application possibilities

Electrical discharges that burn inside an electrolyte bulk and have challenging practical applications are presented. The data on electrophysical and spectral properties of an underwater end-face discharge allowed suggesting the scenario of the discharge origination and development. It includes three stages: bubble growth, a quiet discharge, and an active discharge stage.     

When similar beginnings lead to different ends: Constraints and diversity in cirripede larval development

Summary

Cirripedes are fascinating models for studying both functional constraints and diversity in larval development. Adult cirripedes display an amazing variation in morphology from sessile suspension feeders that still retain many crustacean characters to parasites that have lost virtually all arthropod traits. In contrast, cirripede larval development follows a common scheme with pelagic larvae comprising a series of nauplii followed by a cyprid. Variations are mostly concerned with whether or not the nauplii are feeding and the degree of abbreviation of development, culminating in species where the larvae hatch as cyprids. The cypris larvae are very similar among the ingroups of the Cirripedia, but interesting variations occur in structures used for substrate location and attachment. The cyprid is specialized to both swim through the water and actively explore the substratum by walking on the antennules and using an array of sensory organs in search for a suitable site to attach. This unique morphology and behavior of the cyprid have enabled the Cirripedia to colonize widely different habitats ranging from hard rock to soft animal tissue. Yet, the cyprid can metamorphose into juveniles as different as a setose feeding barnacle and the vermiform stages of the parasitic forms. This emphasizes the importance of the cyprid as one of the key features for the evolutionary success of the Cirripedia.     

3-Dimensional microscopy as a method for volume measurement in cells undergoing apoptosis

Different patterns of cell volume perturbations are commonly used for modes of cell death: necrosis (cell swelling) and apoptosis (cell shrinkage). In this study we employed recently developed three dimensional microscopy for the measurement of the volume of attached vascular smooth muscle cells transfected with E1A-adenoviral protein. These cells undergo rapid apoptosis in the absence of growth factors or in the presence of staurosporine. In 30–60 min of serum deprivation the volume of these cells is increased by ～40% that corresponds to the time point of maximal activation of caspase 3 and chromatin cleavage. In 10–15 min swollen cells exhibit morphological collapse indicated by formation of apoptotic bodies. In contrast to serum-deprived cells, staurosporine leads to attenuation of cell volume by 30%. In this case, apoptotic bodies are detected in ～2.5 h after maximal shrinkage. Thus, our results show that cell shrinkage can not be considered as universal hallmark of apoptosis. The role of stimulus-specific cell volume perturbation in the triggering of the cell death machinery should be examined further.