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971.
Antibodies to human amyloid precursor protein (APP695) and beta‐amyloid peptide (Aβ1‐42) were used to determine timing of amyloidosis in the brain of kokanee salmon (Oncorhynchus nerka kennerlyi) in one of four reproductive stages: immature (IM), maturing (MA), sexually mature (SM), and spawning (SP), representing a range of aging from somatically mature but sexually immature to spawning and somatic senescence. In IM fish, immunoreactive (ir) intracellular APP occurred in 18 of 23 brain regions. During sexual maturation and aging, the number of neurons expressing APP increased in 11 of these APP‐ir regions. Aβ‐ir was absent in IM fish, present in seven regions in MA fish, moderately abundant in 15 regions in SM fish, and was most abundant in all brain regions of SP fish exhibiting Aβ‐ir. Intracellular APP‐ir was observed in brain regions involved in sensory integration, olfaction, vision, stress responses, reproduction, and coordination. Intra‐ and extracellular Aβ1‐42 immunoreactivity (Aβ‐ir) was present in all APP‐ir regions except the nucleus lateralis tuberis (hypothalamus) and Purkinje cells (cerebellum). APP‐ir and Aβ deposition increase during aging. APP‐ir is present in IM fish; Aβ‐ir usually appears first in MA or SM fish and increases in SM fish as does APP‐ir. Extracellular Aβ deposition dramatically increases between SM and SP stages (1–2 weeks) in all fish, indicating an extremely rapid and synchronized process. Rapid senescence observed in pacific salmon could make them a useful model to investigate timing of amyloidosis and neurodegeneration during brain aging. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 11–20, 2002 相似文献
972.
973.
974.
975.
976.
Summary The influence of total nitrification to nitrate or partial nitrification to nitrite on the soil organic nitrogen status was examined. NH
4
+
–15N was added to the soil in the absence and the presence of NaClO3, respectively nitrapyrin. The first chemical inhibits only nitrate formation, the second inhibits total nitrification. The accumulation of nitrite nitrogen in the soil at levels up to 5 mg kg–1 increased the loss of nitrogen. Yet, it did not increase the binding of mineral nitrogen into soil organic matter, relative to the control soil. The data suggest that the biochemistry of the nitrite formation process, rather than the levels of nitrite ions formed, are of primary importance in the role of nitrification mediated nitrosation of soil organic matter. 相似文献
977.
V I Frolenko V A Isabaeva G A Zakharov G I Gorokhova N P Novikova 《Biulleten' eksperimental'no? biologii i meditsiny》1989,108(12):663-666
During the long term noradrenaline injection (0.56 microgram/kg/min-2 hours during six days) the number of connective tissue mast cells decreases in dogs. Mature cells disappears and the percentage of young forms increases. Marked degranulation develops. 5-10 cell groups and chains are formed. The increase of free heparin level and the activation of anticoagulant unit hemostasis correspond to these changes. It is due to mast cells discharge of biologically active heparin which is an unspecific adaptogen. 相似文献
978.
979.
A G Bezrukova A B Oreshkov V M Kolikov G M Simonova V A Bet'kenev 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1989,(9):11-14
Changes in the spectrum of the opacity of biodispersions containing L. acidophilus at the stage of growth have been studied. The pronounced positive correlation between the opacity of dispersion and the titer of cells, determined by the method of ultimate dilutions, have been shown. 相似文献
980.
A D Antipov V A Tiurin N F Avrova A E Khovanskikh V E Kagan 《Biulleten' eksperimental'no? biologii i meditsiny》1989,107(2):169-171
The protective effects of alpha-tocopherol, carnosine and their mixtures on monoamine oxidase activity, accumulation of lipid peroxidation products, lipid fatty acid composition, hydrophobicity and microviscosity of synaptic membranes during lipid peroxidation were studied. It was shown that the protective efficiency is more higher when the mixture of water and liposoluble antioxidants was used. 相似文献