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  • 1
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The effect of MK-801, a non-competitive N-methyl-D-aspartate (NMDA) antagonist, on the kainic acid-induced expression of the inducible heat shock protein 70 kDa (HSP70) and on neuronal death in the rat hippocampus was investigated. HSP70 is expressed in ˜80% of the pyramidal neurons in the CA1 field 1 day after kainic acid injection. The majority of these HSP70-immunopositive neurons exhibited swelling and a hollow appearance in the perikaryon, indicating that they had been injured following kainic acid-elicited limbic seizures. Four days after administration of kainic acid, 87% of the pyramidal neurons in the CA1 field were dead. When a single dose of MK-801 was administered 1 h before kainic acid injection, the number of rats suffering with seizures was reduced, the severity of limbic seizures was attenuated and seizure onset was delayed. Neither HSP70 expression on day 1 nor neuronal loss on day 4 in the CA1 pyramidal cell layer was observed in these animals. A considerable number of HSP70-immunopositive neurons was detected in the dentate hilus, however, and somewhat fewer in the CA3a and CA3c subfields on day 1. Severe neuronal damage in these regions followed on day 4. Interestingly, little HSP70 expression or neuronal loss was observed in the CA3b subfield in these same animals. When a single dose of MK-801 was given 4 h after kainic acid treatment, HSP70 expression was partially blocked; 18% of neurons expressed HSP70 on day 1 and 37% on day 4 in CA1 pyramidal neurons in comparison to the kainic acid controls. About 50% neuronal death was detected in the CA1 pyramidal cell layer 4 days after kainic acid treatment followed by MK-801. When the animals were treated with MK-801 4 h after kainic acid treatment followed by additional daily administration for 3 days, a negligible number of pyramidal neurons expressed HSP70, and the survival of pyramidal cells was significantly increased in the CA1 field. Limbic seizure-induced HSP70 expression not only indicates neuronal injury in the pyramidal cell layer of the hippocampus but also predicts delayed neuronal death, at least in the case of the CA1 field of animals that suffered stage IV—V seizures.
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  • 2
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Using quantitative in situ hybridization and immunohistochemistry the expression of acidic and basic fibroblast growth factors (aFGF, bFGF) in dorsal root ganglia (DRGs) was examined. Around 5% of the small neurons expressed bFGF mRNA in normal DRGs. Nerve injury induced a very dramatic and rapid up-regulation in bFGF mRNA levels, and around 80% of all DRG neurons expressed bFGF mRNA 3 days after axotomy. A distinct increase in bFGF-like immunoreactivity (LI) was also detected as early as 15 h after axotomy. The elevation of bFGF mRNA and protein levels declined after 1 week. bFGF mRNA was also up-regulated in non-neuronal cells following axotomy. Normally bFGF-LI was mainly localized in the nuclei of DRG neurons and in some non-neuronal cells. After nerve section, bFGF-LI was in addition found in the cytoplasm, and many more bFGF-positive non-neuronal cells were observed. By means of confocal microscopy analysis of axotomized DRGs, some bFGF-LI could be detected in vesicle-like structures in the cytoplasm as well as in the nucleoli, in addition to the nuclear location. Application of leukaemia inhibitory factor to the transected sciatic nerve significantly increased the number of bFGF-positive neurons, whereas the bFGF-LI in non-neuronal cells was strongly suppressed. About 70% of the normal DRG neurons expressed aFGF mRNA and aFGF-LI. Axotomy produced a moderate increase in aFGF mRNA levels, but no detectable effect on protein levels. Taken together, the results show that bFGF may be involved in the neuronal response to injury and suggest a role in neuronal survival and regeneration in axotomized DRG neurons.
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  • 3
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Using in situ hybridization, the expression of the mRNA for a neuropeptide Y (NPY) receptor, was studied in lumbar (L) 4 and 5 dorsal root ganglia (DRGs) of normal rats and at various intervals after unilateral sciatic nerve transection. Twenty percent of all normal DRG neurons were NPY receptor mRNA-positive, and the majority of these neurons were of the small type, with only a few labelled medium-sized and large neurons. In L5 normal ganglia NPY receptor mRNA colocalized with substance P, calcitonin gene-related peptide and galanin mRNAs in small neurons, but not in medium-sized or large neurons containing these peptides. NPY receptor mRNA was not observed in somatostatin or nitric oxide synthase mRNA-positive neurons. Sciatic nerve transection induced a marked decrease in NPY receptor mRNA levels. However, in parallel there was a transient increase in the number of NPY receptor mRNA-positive small neuron profiles, but the intensity of labelling was mostly very low, although a few strongly labelled, small neuron profiles were also encountered. In addition, axotomy caused a marked increase in the number of NPY receptor mRNA-positive large neuron profiles in the ipsilateral DRGs, and they constituted 15–20% of counted DRG neuron profiles and 45–65% of counted large neuron profiles, 7–28 days after axotomy. In L5 DRGs, ipsilateral to the axotomy, NPY receptor mRNA colocalized with NPY mRNA in many large and some medium-sized neuron profiles, with galanin mRNA in some small, medium-sized and large neuron profiles and with vasoactive intestinal polypeptide mRNA in some small and medium-sized neuron profiles and a few large profiles. Occasionally, NPY receptor mRNA was observed in nitric oxide synthase mRNA-positive small neurons. In the dorsal horn, NPY receptor mRNA-positive small neurons were concentrated in lamina II at L4 and L5 levels, and were scattered in deeper laminae. No marked changes were observed ipsilateral to the axotomy. No NPY receptor mRNA-positive cells were found in the normal rat gracile nucleus, or in this nucleus after axotomy. These results show that a NPY receptor may be a prejunctional receptor in primary afferent neurons and play a role in the modulation of somatosensatory information, both in normal and lesioned primary afferent DRG cells. However, axotomy induced a distinct shift in NPY receptor mRNA expression from small to large neurons, indicating that sensitivity to NPY is switched from one modality to another. Thus, not only several sensory neuropeptides, as shown in previous studies, but at least also one of the peptide receptors change their expression dramatically in response to axotomy, suggesting complex adaptive responses.
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  • 4
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We established a guinea-pig model of anaphylactic bronchoconstriction provoked in immunized animals by inhalation and intravenous administration of 4,4-methyltetrahydrophthalic anhydride (MTHPA) and hexahydrophthalic anhydride (HHPA). Guinea pigs were immunized intradermally with either MTHPA (n= 8) or HHPA (n= 8) suspended in olive oil. Control animals (n= 8) were injected with olive oil alone. After 4 weeks, the animals were challenged during mechanical ventilation by inhalation or intravenous administration of MTHPA or HHPA conjugated with guinea-pig serum albumin (GPSA). Airway flow, and airway and esophageal pressures were measured. Resistance (R) and static compliance (Cst) of the respiratory system (rs), lung (1), and chest wall were studied with the flow-interruption technique. After challenge with MTHPA-GPSA or HHPA-GPSA, R, rs and R, 1 increased dramatically while Cst, rs and Cst,1 decreased, and severe arterial hypoxia developed. The reaction occurred at a well-defined dose of anhydride and lasted about 30 min. When the same dose was repeated after 30 min, the response was much attenuated. MTHPA and HHPA can induce asthma in guinea pigs. The dose-response curve at antigen challenge is steep. Once a threshold dose is reached, a severe reaction occurs. The reactivity is then exhausted. This model may be suitable for assessing occupational asthma caused by acid anhydrides and possibly by other low-molecular-weight chemicals.
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food quality 16 (1993), S. 0 
    ISSN: 1745-4557
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect on peach [Prunus persica (L) Batsch.] firmness during storage was investigated for the following tree irrigation schedules: no irrigation, irrigation beginning at budbreak until October, and irrigation beginning at stage III of fruit growth until October. Peaches (cv ‘Cresthaven’) from the three tree irrigation schedules were harvested at two ripeness stages and were stored at 2C, 90% RH. After 3, 6, 9, 13, and 16 days of storage, peach firmness was tested by a modified Effegi flesh probe test and drop impact test. From the flesh probe test, the bioyield force, maximum force, and elastic modulus were measured and from the drop impact test, the contact time, peak force/time-to-peak force, and percentage of energy absorbed were measured. None of these parameters were significantly affected by the tree irrigation schedules. Riper peaches were softer during the whole storage period. Less ripe peaches had more variation in firmness parameters during storage. The average firmness of peaches changed only slightly during the first nine days of storage, then softened quickly thereafter.
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  • 6
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 59 (1994), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fresh cooked ginger and processed ginger products were extracted with methanol and analyzed by HPLC to study changes in the levels of [6]-, [8]-, and [10]-gingerols after the products had been cooked and processed, and during storage of the products. Sensory tests evaluated the intensity of pungency in different processed products. Cooking and processing of paste and scnbei decreased (p 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00221147:JFDS1338:les" location="les.gif"/〉 0.05) gingerol levels, but blanching and freeze-drying had no effect. Gingerols in all products degraded gradually with storage. Ginger powder had a lower degradation rate than the paste stored at 4°C. Likewise, ginger senbei was more stable than ginger powder stored at room temperature (≅ 23°C).
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  • 9
    ISSN: 1600-0714
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Oral hyperpigmentation has been observed in six HIV-infected patients, in two of whom systemic medication (ketokonazole, clofazimine) was supposed to be etiologically involved. Histologically, pigment was found in epithelial basal cells and particularly in subepithelial connective tissue. Ultrastructurally, the presence of premature melanosomes in subepithelial keratinocytes was of interest. Stimulation of melanocytes during HIV infection may occur in association with immunopathologic changes in the oral mucosa.
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  • 10
    ISSN: 1600-0714
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Twelve biopsies of clinically normal oral mucosa taken from HIV seropositive patients have been investigated by means of light- and electron microscopy. Vascular abnormalities were found in all biopsies, regardless of the clinical stage of the HIV infection. In particular slit-like vascular channels, sparseness of intercellular junctions and swollen, protruded endothelial cells with an increased quantity of Weibel-Palade bodies were noticed. These findings were similar to those described in lesions of early stage Kaposi's sarcoma.
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