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  • 1
    Electronic Resource
    Electronic Resource
    Increased 5-hydroxytryptamine immunoreactivity in traumatized spinal cord (1990)
    Springer
    Acta neuropathologica 80 (1990), S. 12-17 
    Details
    ISSN: 1432-0533
    Keywords: Serotonin (5-hydroxytryptamine, 5-HT) ; Spinal cord trauma ; Ventral horn ; p-Chlorophenyl alanine ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possibility that serotonin (5-hydroxytryptamine, 5-HT) is involved in the early tissue reactions occurring in spinal cord trauma was examined in a rat model using an immunocytochemical technique. The injury was made in the form of a 5-mm long and 2.5-mm wide lesion of the right dorsal horn at the level of T10–11. Injured rats, pretreated with the 5-HT synthesis blocking agent, p-chlorophenyl alanine (p-CPA) were compared with untreated injured controls and the animals were allowed to survive for 5 h. The distribution of 5-HT was examined in proximal and distal cross-sections of the cord, located 2 and 5 mm away from the injury. Normal rats showed immunoreactive material in nerve cell processes and in a few nerve cell bodies of the ventral horns. The trauma to the spinal cord caused a marked increase in 5-HT immunoreactivity in the segments located 2 mm proximal and distal to the injury, particularly in the ipsilateral ventral horn. The segment located 5 mm distal to the lesion showed a similar increase in immunoreactivity but it was apparently less pronounced in the corresponding proximal segment. Treatment with p-CPA markedly reduced the trauma-induced increase in 5-HT immunoreactivity in all the segments. These immunohistochemical findings were in line with the changes in the contents of 5-HT measured biochemically in corresponding spinal cord segments. At the onset of the trauma to the spinal cord 5-HT is thus present in the tissue, mainly in the form of 5-HT-containing nerve cell processes. Biochemical determinations also revealed that there is an increased amount of 5-HT in the traumatized spinal cord. The present study indicates that this is at least partly due to an increased amount of 5-HT in neurons and nerve cell processes of the perifocal region. The pathophysiollogical significance of the observed 5-HT-reaction in spinal cord injury is not known in all its details. However, 5-HT might be implicated in such tissue reaction, such as increased microvascular permea bility and edema formation occurring in the early period after trauma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294216
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  • 2
    Electronic Resource
    Electronic Resource
    Edema formation and cellular alterations following spinal cord injury in the rat and their modification with p-chlorophenylalanine (1990)
    Springer
    Acta neuropathologica 79 (1990), S. 604-610 
    Details
    ISSN: 1432-0533
    Keywords: Trauma ; Spinal cord injury ; Edema ; Serotonin ; p-CPA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possibility that serotonin can modify the early pathological sequences occurring in spinal cord trauma was investigated in a rat model. To that end we took advantage of the possibility of influencing serotonin pharmacologically by treating animals with a serotonin synthesis inhibitor, p-chlorophenylalanine (p-CPA) before the production of the injury and compared the results with injured, untreated controls. A unilateral incision was made into the dorsal horn of the lower thoracic cord (about 2.5 mm deep, 4.5 mm long) and the trauma. The injured region from untreated animals showed macroscopically at that time a pronounced swelling and the water content had increased by 3.5% as compared to intact controls. The segments rostral and caudal to the lesion also exhibited a profound increase in water content. Light microscopy revealed a significant expansion of the spinal cord as compared to controls. The swelling was most pronounced in the gray matter on the injured side. Electron microscopy showed distorted neurons, swollen astrocytes and extracellular edema in the gray matter in and around the primary lesion. There was also a sponginess in the surrounding white matter with disruption of myelin, collapsed axons and widened periaxonal spaces. Pretreatment of the rats with p-CPA significantly reduced the swelling of the injured spinal cord and there was no visible expansion. The ipsilateral edema in the central gray matter was considerable less pronounced as compared to that in untreated animals. The increase in water content was less than 1% in these animals. The neuronal and glial cell changes were also markedly reduced in the drugtreated rats. The disruption of myelin and the vacuolation of the gray matter were much less severe. Our results show that p-CPA can markedly modify the edema and the cellular changes occurring in the traumatic spinal injury and indicate that serotonin is somehow involved in the production of the early, and thus important, pathological events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294237
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of p-chlorophenylalanine on microvascular permeability changes in spinal cord trauma (1990)
    Springer
    Acta neuropathologica 79 (1990), S. 595-603 
    Details
    ISSN: 1432-0533
    Keywords: Trauma ; Spinal cord injury ; Microvascular permeability ; Serotonin ; p-Chlorophenylalanine (p-CPA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possibility that serotonin can take part in the initiation of the increased microvascular permeability occurring in a spinal cord trauma was investigated in a rat model with 131I-sodium and lanthanum as tracers. We influenced the serotonin content in the tissue pharmacologically by treating animals with a serotonin synthesis inhibitor, p-chlorophenylalanine (p-CPA), before the production of the injury and compared the results with injured, untreated controls. A small incision was made in the dorsal horn of the lower thoracic cord. It caused a progressive extravasation of 131I-sodium in the damaged segment, measured after 1,2 and 5 h. Rostral and caudal segments also showed a significant but lower accumulation of 131I-sodium. Lanthanum added to the fixative was used as an ionic tracer detectable by electron microscopy. The endothelial cells of microvessels removed from the perifocal region after 5 h showed a marked increase in the number of lanthanum-filled vesicles. Many endothelial cells had a diffuse penetration of the tracer into the cytoplasm and the basement membrane. However, the tight junctions usually remained closed to lanthanum. Pretreatment with p-CPA markedly reduced the extravasation of 131I-sodium measured at 5 h in the traumatized cord. At the cellular level, the endothelial vesicles filled with lanthanum approached the condition of uninjured animals. The diffuse infiltration of lanthanum into endothelial cells and its spread into the basement membrane of the vascular wall were usually absent. Our results indicate that serotonin plays a role in the initiation of the increased microvascular permeability which occurs in spinal cord injuries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294236
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  • 4
    Electronic Resource
    Electronic Resource
    Vascular permeability of spinal nerve roots (1990)
    Springer
    Acta neuropathologica 81 (1990), S. 148-154 
    Details
    ISSN: 1432-0533
    Keywords: Spinal nerve roots ; Blood vessels ; Vascular permeability ; Lanthanum ; Evans blue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The permeability of blood vessels in rat spinal nerve roots was investigated with Evans blue-albumin as an in vivo macromolecular tracer and lanthanum as tracers as an electron microscopic ionic marker added to a fixative. Rats injected intravenously with Evans blue, showed macroscopic distinct staining of dorsal root ganglia, whereas spinal nerve roots remained unstained. Fluorescence microscopy, however, revealed clear extravascular fluorescence both in ventral and dorsal roots 2 or 18 h after tracer administration. Two different types of blood vessels exists in spinal nerve root; large extrinsic (radicular) in the root sheath and minute intrinsic vessels in the parenchyma. Lanthanum added to a fixative, perfused through the vessels was detected in the lumen of both types of vessels, usually adhering to the luminal plasma membrane and in many invaginations from that membrane. Lanthanum also entered the clefts between endothelial cells but was always stopped at the junctions which are, thus, of the tight type. Diffuse penetration of the compound into the cytoplasm was seen in one endothelial cell, but no fenestrations were detected. Junctions between the endothelial cells of vessel in rat spinal nerve roots are impermeable to lanthanum and most likely also to other large molecular substances like albumin. Thus, probable routes for serum albumin to enter the nerve rools, where it normally is present, must be either by centripetal extracellular diffusion from the ganglia and the peripheral nerve or by vascular leakage in the roots, caused by for instance pinocytosis across endothelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334503
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  • 5
    Electronic Resource
    Electronic Resource
    Maternal vitamin A restriction alters biochemical development of the brain in rats (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 208-211 
    Details
    ISSN: 1420-9071
    Keywords: Brain development ; DNA ; RNA ; protein ; vitamin A ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The biochemical development of the fetal brain in relation to maternal vitamin A restriction was studied in rats. The vitamin A status of pregnant rats was varied by supplying low, medium and adequate amounts (6, 40, and 100 μg retinol/day/kg body weight, respectively) of vitamin A during pregnancy and suckling. The maternal vitamin A restriction caused an altered brain development in terms of tissue weight, DNA, RNA and protein levels, and biosynthesis of DNA and protein from [3H]-thymidine and [3H]-leucine, respectively. A dose-dependent effect of maternal vitamin A restriction on the metabolism of DNA, RNA and protein was noticed in the developing fetal brain of rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02027317
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  • 6
    Electronic Resource
    Electronic Resource
    Crossability and embryo rescue enhancement in wide crosses between wheat and three Agropyron species (1990)
    Springer
    Euphytica 49 (1990), S. 209-214 
    Details
    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; Agropyron spp. ; embryo rescue ; wide crosses ; crossability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Soft winter wheat lines were crossed with Agropyron intermedium, A. elongatum and A. trichophorum using pollen from single plants of Agropyron spp. to pollinate wheat spikes. Not only species but also individual plants within varieties of Agropyron species differed in percent seed set with a wheat genotype. In two arrays of crosses between two phenotypically different plants of A. elongatum and nine wheat lines, one Agropyron plant gave higher seed set (overall=27.1%) than the other (overall=3.7%). The differences were significant in seven of the nine cross combinations. Results are consistent with the hypothesis that these two plants differ in their crossability as pollen parents with wheat, and suggest the possibility of occurrence of crossability genes in wheatgrasses. The success rate of hybrid embryo rescue was higher (87.5%) with cold treatment (4°C) than without cold treatment (75.0%) of excised embryos on culture media. Results underscore the significance of genotype of the alien species for crossing with low crossable wheats, and of the physical factors for improving embryo rescue in wide crosses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00036290
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  • 7
    Electronic Resource
    Electronic Resource
    Mechanisms of resistance in sorghum to head bug, Calocoris angustatus (1990)
    Springer
    Entomologia experimentalis et applicata 57 (1990), S. 285-294 
    Details
    ISSN: 1570-7458
    Keywords: Head bug ; Calocoris angustatus ; sorghum ; resistance mechanisms ; preference ; antibiosis ; consumption and utilization of food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les mécanismes de la résistance du sorgho à la punaise C. angustatus ont été examinés au champ et au laboratoire. Les préférences des adultes ont été examinées avec choix multiples au champ et au laboratoire sur les 5 cultivars relativement moins sensibles (IS 2761, IS 9692, IS 17610, IS 17618, IS 17645) comparés aux hybrides commerciaux très sensibles (CSH 1, CSH 5, CSH 9). Les différences ont été confirmées avec des choix binaires au laboratoire. L'absence de préférence pour un cultivar est une des composantes de la résistance du sorgho à la punaise. Mais l'absence de préférence n'est cependant pas prouvée en cage au champ au par des expériences en olfactomètre sans choix au laboratoire. La ponte a été étudié sur 8 ‘génotypes’ pendant la saison des pluies de 1983 et sur 6 génotypes pendant la saison des pluies et après celle-ci en 1983–84. Les résultats montrent que la réduction de la ponte est une composante importante de la résistance sur IS 17645, IS 17610 et IS 17618. Pour définir le niveau d'antibiose, l'étude du cycle a été menée au laboratoire sur 5 cultivars relativement peu sensibles (IS 2761, IS 9692, IS 17610, IS 176618, IS 17645) et 3 sensibles (CSH 1, CSH 5, CSH 9). Le développement post-embryonnaire est prolongé d'un jour au deux quand les larves sont élevées sur grains laiteux de IS 17610 ou IS 17645. Les larves de 5e stade et les adultes ont des poids plus faibles sur IS 17610 et IS 9692. Les indices de consommation et d'utilisation des aliments ont été calculés pour IS 2761, IS 6984, CSH 5 et Swarna; l'utilisation de grains de IS 2761 et IS 69884, comparée aux grains des cultivars CSH 5 et Swarna, est relativement moins efficace. C1 et GR sont plus faibles sur grains d'IS 2761 de 20 jours que de 12 jours.
    Notes: Abstract Cultivar preference/nonpreference for feeding is one of the components of resistance to the sorghum head bug, Calocoris angustatus Lethiery (Hemiptera: Miridae). IS 2761, IS 9692, IS 17610, IS 17618 and IS 17645 were not preferred by the adults of c. angustatus under multi- or two-choice conditions. However, cultivar preference was not evident under no-choice tests or headcage conditions. Reduced oviposition is an important component of resistance to head bugs in IS 17645, IS 17610 and IS 17618. Post-embryonic development was extended by 1–2 days when nymphs were fed on these genotypes. Fifth instar nymphs and adults had lower weights when reared on IS 17610 and IS 9692. Nymphal survival was relatively lower on IS 9692, IS 17610 and IS 17645. Fourth instar nymphs were relatively less efficient in food utilization when fed on grain of IS 2761 and IS 6984 as compared with the susceptible cultivars CSH 5 and Swarna. Stage of grain development influenced the indices of consumption and utilization of food by head bugs. Consumption index (CI) and growth rate was lower on 20-day-old grain of IS 2761 as compared with 12-day-old grain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00355028
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