Changes in vasoactive intestinal peptide, pituitary adenylate cyclase-activating polypeptide and neuropeptide Y-ergic structures of the enteric nervous system in the carcinoma of the human large intestine.

This investigation was aimed at immunohistochemical analysis of potential changes in the enteric nervous system caused by cancer of the large intestine. In this purpose, neurons and nerve fibers of intestinal plexuses containing neuropeptides: vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating polypeptide (PACAP) and neuropeptide Y (NPY), in pathologically changed part of the large intestine were microscpically observed and compared. Samples were taken from patients operated due to cancer of the sigmoid colon and rectum. The number of neurons and density of nerve fibres containing neuropeptides found in sections with cancer tissues were compared to those observed in sections from the uninvolved intestinal wall. Changes relating to reductions in the number of NPY-ergic neurons and density of nerve fibres in submucous and myenteric plexuses in the sections with cancer tissues (pathological sections) were statistically significant. A statistically similar presence of VIP-ergic and PACAP-ergic neurons in the submucosal and myenteric plexuses was observed in both the pathological and control sections. On the other hand, in the pathological sections, VIP-ergic nerve fibres in the myenteric plexuses and PACAP-ergic nerve fibres in the submucosal and myenteric plexuses were found to be less dense. Analysis revealed changes in pathologically affected part of the large intestine may caused disruption of proper intestinal function. Observed changes in the neural elements which are responsible for relaxation of the intestine may suggest dysfunction in the innervation of this part of the colon

Mapping of the Sequences Directing Localization of the Drosophila Germ Cell-Expressed Protein (GCE)

Drosophila melanogaster germ cell-expressed protein (GCE) belongs to the family of bHLH-PAS transcription factors that are the regulators of gene expression networks that determine many physiological and developmental processes. GCE is a homolog of D. melanogaster methoprene tolerant protein (MET), a key mediator of anti-metamorphic signaling in insects and the putative juvenile hormone receptor. Recently, it has been shown that the functions of MET and GCE are only partially redundant and tissue specific. The ability of bHLH-PAS proteins to fulfill their function depends on proper intracellular trafficking, determined by specific sequences, i.e. the nuclear localization signal (NLS) and the nuclear export signal (NES). Nevertheless, until now no data has been published on the GCE intracellular shuttling and localization signals. We performed confocal microscopy analysis of the subcellular distribution of GCE fused with yellow fluorescent protein (YFP) and YFP-GCE derivatives which allowed us to characterize the details of the subcellular traffic of this protein. We demonstrate that GCE possess specific pattern of localization signals, only partially consistent with presented previously for MET. The presence of a strong NLS in the C-terminal part of GCE, seems to be unique and important feature of this protein. The intracellular localization of GCE appears to be determined by the NLSs localized in PAS-B domain and C-terminal fragment of GCE, and NESs localized in PAS-A, PAS-B domains and C-terminal fragment of GCE. NLSs activity can be modified by juvenile hormone (JH) and other partners, likely 14-3-3 proteins

Wpływ niektórych regulatorów wzrostu na syntezę kwasów nukleinowych i białek w cyklach życiowych komórek nici spermatogenicznych Chara vulgaris L.

Badano wpływ regulatorów wzrostu : IAA, NAA, kinetyny, BA, GA₃ i CCC na syntezę kwasów nukleinowych i białek w kolejnych etapach interfazy oraz rozmiary i czas trwania cyklu życiowego 4 lub 5 pokoleń komórek nici spermatogenicznych Chara vulgaris L.

The role of plant growth substances in the regulation of the cell cycle in antheridial filaments of Chara vulgaris L. I. Effect of gibberellic acid on some, processes in the course of the cell cycle

The effect of gibberellic acid (10-4 M) on the incorporation of 8-14C adenine, 3H phenylalanine, the dimensions of mitotic cells and the durations of particular stages in the cell cycle were studied in synchronously dividing cells of the antheridial filaments in Chara vulgaris L. during succesive periods of growth and differentiation. GA3 strongly stimulates the uptake of both labeled precursors in the course of a whole interphase and in all generations of the antheridial filaments; approximatively in proportion to the intensity of the process in the control. The gibberellin causes a slight increment in cell dimensions and strongly reduces the cell cycle durations: the S, G2, and M to a similar degree. The earlier is the generation of the antheridial filament, the more pronounced is the influence of the plant growth substance. Since the gibberellin stimulated the course of all examined processes, the present study did not reveal any stage of interphase to be especially sensitive to GA3. The results suggest to interpret the effect of GA3 as an unspecific stimulator of metabolism in cells of the antheridial filaments of Chara vulgaris L

Effect of kinetin on the course of cell cycle in successive developmental stages of the antheridial filaments of Chara vulgaris L.

Effects of kinetin on the course of cell cycle in successive developmental stages of the antheridial filaments of Chara vulgaris L. were investigated. A shortening of the duration of cell cycles has been observed, particularly in initial. and final developmental stages. S phase. shortened in all stages whereas G2 phase+mitosis shortened in early but become longer in late developmental stages of filaments. Incorporation of 14C-adenine into cell nuclei increased after kinetin treatment in 4- and 8-celled filaments whereas that of 3H-phenylalanine increased in 8- and particularly 16-celled ones. This plant growth regulator stimulated also the 3H-thymidine incorporation into cells in studied developmental stages of filaments. The stimulation of radioactive phenylalanine incorporation into nucleus and cytoplasm was stronger in late G2 phase. A participation of cytokinins in the control of cell cycle in relation to process of differentiation of antheridial cells is discussed. A possibility of changes in the cytokinin content in antheridia and antheridial filament cells during their; development has been postulated

Callose formation in injured cells of the vegetative and generative thallus of Chara vulgaris L. Absence of callose in the process of cytodifferentiation

In an alga Chara vulgaris L. the processes of differentiation of vegetative system cells of the thallus, and initiation and development of generative organs are not associated with callose formation. It was demonstrated that damage to any of the somatic cells and also generative and nongenerative cells of the antheridium and oogonium are capable of callose formation independently of their developmental stage. The localisation and thickness of these layers depend on the way the cells are injured and on their size. The protective role of callose in such cells may consist, beside strengthening the damaged walls, in protection of the symplast by formation of callose deposits on the walls with plasmodesmata; it may also consist in increasing the water potential of the cells. Experiments in which callose deposition was provoked by pressing of the cells or damage leading to a sudden increase of the water potential of the extracellular environment suggest that a sudden increase of tension in the cells may be a factor triggering the "callose effect"