Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    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
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    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
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 81 (1990), S. 148-154 
    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
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0533
    Keywords: Spinal cord trauma ; Edema ; Myelin basic protein ; Indomethacin ; Prostaglandins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possibility that prostaglandins participate in the formation of perifocal edema and cell changes following a localized trauma to the spinal cord was investigated in a rat model. A laminectomy was performed in urethane-anesthetized animals at the thoracic T10–11 segment. Using a scalpel blade a unilateral lesion, about 2 mm deep and 5 mm long was made 1 mm to the right of the midline. The deepest part of the injury occupied Rexed's lamina VII of the dorsal horn. Animals were pretreated with the prostaglandin synthesis inhibitor, indomethacin (10 mg/kg, i.p. 30 min prior to trauma). Five hours after the injury the water content was determined and cell changes in and around the primary lesion were examined by light and electron microscopy. Normal and injured rats without indomethacin pretreatment served as controls. Untreated injured rats showed a profound increase of water content in the traumatized T10–11, the rostral (T9) and caudal (T12) segments compared with normal rats. These segments also exhibited marked cell changes in ipsilateral and contralateral dorsal and ventral horns. The gray matter had a spongy appearance and some nerve cells were condensed and distorted. The white matter contained many distorted fibers. Immunostaining for myelin basic protein showed a marked reduction of reaction product in the injured animals compared with normal rats. Ultrastructurally widened extracellular spaces, cytoplasmic vacuolation, swollen and condensed neurons, swollen astrocytes and vesiculation of myelin were frequent findings. Pretreatment of rats with indomethacin significantly reduced the accumulation of water in the traumatized and in the rostral and caudal segments. The structural changes were less pronounced particularly in the cranial and caudal segments. The results indicate that prostaglandins somehow are involved in the pathophysiology of perifocal spinal cord injury and influence both the fluid microenvironment and the early cell changes.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Colonisation assessments confirmed that Trichoderma harzianum biotypes Th1, Th2a, Th2b and Th3 inoculated into two distinct compost types at spawning became established by first flush assessment; the extension rate of two Th2 isolates was over 1000 times that of Th1 and Th3. Results subsequently confirmed that while Th1 and Th3 did not significantly affect yield, Th2 could reduce mushroom quality and productivity by as much as 80%. Analysis of compost type also indicated that the speed and magnitude of T. harzianum colonisation was influenced by key compost characteristics, most notably, moisture, ash content and degree of fermentation. This study has shown that compost parameters which have a positive influence on Agaricus growth and productivity also resulted in increased compost colonisation by T. harzianum. Commercially acceptable yields obtained from uninoculated compost confirmed that production of a high quality, productive substrate does not confer inherent immunity to colonisation by T. harzianum.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    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
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0533
    Keywords: Spinal cord trauma ; Glial fibrillary acidic protein ; Serotonin ; p-Chlorophenylalanine ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The possibility that serotonin may influence the early response of astrocytes around a spinal cord trauma was investigated in a rat model by making a unilateral incision into the right dorsal horn of the T10-11 segments. One group of rats received a serotonin synthesis inhibitor, p-chlorophenylalanine (p-CPA) before injury in doses which cause a depletion of serotonin in the cord. Another group of traumatised rats did not receive p-CPA. All animals were allowed to survive for 5 h. Samples for immunohistochemistry were taken from the T9, T10-11 and T12 segments of the cord. Paraffin sections were immunostained for glial fibrillary acidic protein (GFAP) using monoclonal antibodies and avidin-biotin complex technique. Trauma to the cord resulted in a marked increase of GFAP immunoreactivity in all the investigated segments, particularly in the ipsilateral side. Pretreatment with p-CPA markedly reduced the GFAP response. This drug did not by itself influence the GFAP immunoreactivity of the cord of untraumatised rats. Our results show that trauma to the spinal cord induces a rapid enhancement of GFAP immunoreactivity in the cord which is present even far away from the primary lesion. This response can be prevented by pretreatment with the serotonin synthesis inhibitor, p-CPA. The results indicate that serotonin influences the increase of GFAP immunoreactivity following spinal cord injury either directly or indirectly, for instance by its microvascular reactions.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A wide range of thermophilic and thermo-tolerant fungi can cause spoilage of bagasse, grain, groundnut, hay, palm kernels, peat, wood chips and other agricultural crops. Thermophilous fungi are also reported to be involved in the processing of agricultural produce such as cocoa, guayule and tobacco; biodegradation of lignocellulose, animal and other wastes in controlled conditions. The habitat of thermophilous fungiranges from hot natural environment to manmade environments such as coal spoil tips and aircraft fuel tanks.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Spent mushroom substrate (SMS) leached with water or treated with chelating agents to remove metal cations, pasteurised to remove any harmful micro-organisms and mixed with peat has potential as a casing material for mushroom production. The microbial and chemical changes in SMS after treatment with citric acid, ethylene diaminetetraacetic acid (EDTA) and water were compared; treatment with the chelating agents resulted in lower ash content, conductivity and minerals, higher fibre fractions, carbon, hydrogen and nitrogen. The microbial and chemical changes in the materials after treatment with the two chelators and water were compared. Blending peat with the heat-treated materials at a ratio of 1:1 resulted in improved physical properties. The casings prepared from the test materials and the control, consisting of 100% peat, were compared after neutralising with lime for their productivity in a mushroom yield trial. As expected, the compost bags cased with the control were the most productive compared to the other casings. Of the three treated materials, casing prepared from SMS treated with EDTA blended with peat was the most productive. Dry matter of harvested mushrooms from chelated-SMS casings was significantly higher than the control casing. Comparison of the main components of peat and chelated SMS revealed that the major differences were in the proportions of ash, lipid, lignin and fibre fractions. The stability of some of these components, when complexed with metal cations present in lime may play an important role in determining the composition of the cell wall in fruiting bodies leading to high dry matter content.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Among the four strains of Pleurotus tested, hybrid strain A was found to degrade flax shive faster than the other three strains. Strain A produced more polygalacturonase, pectinlyase, cellulase and laccase enzymes than the other three strains of Pleurotus. Maximum activities of laccase and polysaccharide degrading enzymes were correlated with high weight loss, reduction in the yield of lignin and holocellulose and the degree of polymerisation of holocellulose. The addition of crude extract of flax shive on unextracted-shive increased the production of primordia of all the four strains, but it did not increase the degradation of flax shive. Flavonoid type compounds were detected in the crude extract of flax shive and they may be responsible for the increase in the production of mushroom primordia.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...