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981.
Venero JL Revuelta M Atiki L Santiago M Toms-Camardiel MC Cano J Machado A 《Free radical biology & medicine》2003,34(1):111-123
We have evaluated the ability of the injured nigrostriatal dopaminergic system to produce highly reactive hydroxyl radicals ((*)OH) by the electrochemical detection of salicylate hydroxylation. Unilateral transection of the medial forebrain bundle transiently increased the formation of (*)OH in substantia nigra (SN) but not in striatum during the first 48 h postlesion, when most relevant changes in terms of oxidatively modified proteins take place. Short-term adaptive axotomy-induced changes in substantia nigra included downregulation of nigral tyrosine hydroxylase (TH) and dopamine transporter (DAT) mRNA expression and more intense TH immunoreactivity. Maintained inhibition of monoamine oxidase activity with deprenyl totally prevented the axotomy-induced formation of (*)OH, thus demonstrating the dopaminergic nature of these radicals. In contrast, deprenyl treatment, which is associated with a diminution in free radical production, failed to delay the onset of dopaminergic degeneration. This observation highlights the importance of being extremely cautious when analyzing parameters of oxidative stress and extrapolating them as a primary cause of cell death in the context of neurodegeneration. Long-term adaptive changes included a dramatic downregulation of DAT mRNA expression along with a moderate decrease in TH mRNA levels in SN. We anticipate a key regulatory role of the DAT to maximally optimize dopaminergic transmission in the synaptic cleft under conditions of degeneration. 相似文献
982.
983.
Penstemon pinorum, from the Pine Valley Mountains of southwestern Utah, is described and illustrated. It is compared morphologically and ecologically to other members of sectionCristati. 相似文献
984.
A new species,Sphaeromeria ruthiae, from Zion National Park, and three new combinations,S. martirensis,S. compacta, andS. potentilloides var.nitrophila, are presented. Morphological and anatomical evidence is used to support the recognition ofSphaeromeria as distinct fromTanacetum. 相似文献
985.
986.
Leila V. Alegrio Raimundo Braz Fo. Otto R. Gottlieb J.Guilherme S. Maia 《Phytochemistry》1981,20(8):1963-1965
A re-examination of the trunk wood of Licaria armeniaca led to the isolation of 6,7-dimethoxycoumarin, 1,2,3-trimethoxy-7-oxoaporphine (tri-O-methylmoschatoline, 2e-(3,4,5-trimethoxyphenyl)-6e-(3,4-dimethoxyphenyl)-3,7-dioxabicyclo [3.3.0]octan (magnolin) and a novel neolignan (7S,8R,1′S,2′S,3′S)-2′-acetoxy-1′-allyl-3′,5′-dimethoxy-8-methyl-7-piperonyl-bicyclo [3.2.1]-oct-5′- en-4′-one. 相似文献
987.
Leila Risteli Juha Risteli Annegret Ihme Thomas Krieg Peter K. Müller 《Biochemical and biophysical research communications》1980,96(4):1778-1784
Normal and Ehlers-Danlos syndrome type VI human skin and cornea fibroblasts were assayed for lysyl hydroxylase activity using two different collagen types as substrates. The enzyme from normal fibroblasts hydroxylated type I collagen more readily than type IV collagen. In the diseased cells the enzyme activity was significantly reduced, and the residual activity was preferentially directed towards type IV collagen. This suggests the existence of isoenzymes of lysyl hydroxylase or an alteration in the Ehlers-Danlos syndrome type VI that affects the binding of type I collagen more than that of type IV collagen. 相似文献
988.
Leila M. Lopes-Alves Lucia Mendonça-Previato Bernard Fournet Pierre Degand José O. Previato 《Glycoconjugate journal》1992,9(2):75-81
-Elimination of peptidorhamnomannans purified from yeast-like and mycelial phases ofSporothrix schenckii released neutral and acidic reduced oligosaccharides that were O linked to serine and/or threonine. Man-(1–2)Man-ol, Rha(1–3)Man(1–2)Man-ol, Rha(1–4)GlcA(1–2)Man(1–2)Man-ol, and Rha(1–4)[Rha(1–2)] GlcA(1–2)Man(1–2)Man-ol were characterized based on methylation analysis, proton magnetic resonance and fast atom bombardment mass spectrometry.Abbreviations FAB
fast atom bombardment
- GLC
gas liquid chromatography
- GlcA
d-glucopyranosyluronic acid
- Man
d-mannopyranose
- Man-ol
d-mannitol
- MS
mass spectrometry
- NMR
nuclear magnetic resonance
- Rha
l-rhamnopyranose 相似文献
989.
Diego A. Golombek Esteban Escolar Leila J. Burin Marí a G. De Brito S nchez Diego Fern ndez Duque Daniel P. Cardinali 《Chronobiology international》1992,9(2):124-131
We endeavored to determine whether three behavioral effects of melatonin in rodents, i.e., depression of locomotor activity in hamsters, analgesia in mice, and impairment of 3-mercaptopropionic acid (3-MP) convulsions, exhibited the time dependency known to occur for several neuroendocrine effects of the hormone. Activity was monitored and registered by means of an optical acto-meter, and analgesia was assessed by the hot-plate procedure. Locomotor activity, analgesia, and seizure susceptibility were maximal at the beginning of the scoto-phase and minimal at noon. The effects of melatonin on the three parameters peaked at early night. The administration of the benzodiazepine antagonist fluma-zenil, although unable by itself to modify locomotor activity, pain, or seizure threshold, blunted the activity of melatonin. These results suggest that the time-dependent effects of melatonin on specific rodent behaviors may be mediated by central synapses employing 7-aminobutyric acid (GABA) as an inhibitory transmitter. 相似文献
990.
Shaida Mahmoudi Mohamad Javad Chaichi Mojtaba Shamsipur Ome Leila Nazari Abdolraouf Samadi-Maybodi 《Luminescence》2023,38(10):1711-1719
Atropine (AT) is an anticholinergic drug. AT is abundantly in Datura plant seeds. Fe3O4@Zn/Mg MOF (Fe3O4@MOF) composite was synthesized. The compound had a high peroxidase-like activity in a chemiluminescence (CL) reaction. Addition of AT quenched CL. The linear range and limit of detection were 5–600 μg L−1 and 2 × 10−2 μg L−1. This method is fast, reversible, and selective, without biodegradability effects, high accuracy, and precision for measuring AT in the Datura plant. 相似文献