Browsing by Subject "Hamster"

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    Comparison of NADPH diaphorase activity in the brains of hamsters infected with scrapie strains 139H or 263K or with normal hamster brain homogenate
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Ye, X.; Meeker, H. C.; Scallet, A. C.; Carp, R. I.
    Previous studies showed that the histopathological changes found in the brains of scrapieinfected animals included amyloid plaque formation, vacuolation , gliosis and neuronal and neurite degeneration. There were differences in the histopathological findings as a function of the scrapie strain-host combination. NADPH-diaphorase (NADPHd) has been shown to be a selective histoch emical marker for neurons containing nitric oxide (NO) synthase. Neuronal cell damage caused by NOS in brain has been reported to be associated with many neurodegenerative diseases. In this study, we used NADPH-d histostaining to investigate changes in the NOS system in brains of 139H- and 263K-infected hamsters and compared the results to normal hamster brain (NHB) injected animals. We observed that some of the NADPH-d histostaining neurons in the cortex of scrapie-infected hamsters appeared to be atrophic: the neurons were smaller and had fewer neurites. The NADPH-d histostaining intensity of neurons or astrocytes in septum, thalamus, hypothalamus and amygdala of 139H- and 263K-infected hamsters was greater than in control hamsters. Astrocytes in the thalamus, hypothalamus and lower part of the cortex (layers 4 to 6) in 263K-infected hamsters were more intensely stained for NADPH-d than in either 139Hinfected hamsters or controls. Our results suggest that changes in NADPH-d system might playa role in the diversity of scrapie induced neurodegenerative changes.
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    Cytochemical and biochemical evidences for a complex tridimensional structure of the hamster zona pellucida
    (Murcia : F. Hernández, 2009) Saavedra Leos, María Dolores; Gutiérrez Gallego, Ricardo; Fayrer Hosken, Richard; Ballesta Germán, José; Avilés Sánchez, Manuel; Castells Mora, María Teresa; Izquierdo Rico, María José; Jíménez Movilla, María; Martínez Alonso, Emma; Biología Celular
    Zona pellucida (ZP) is an extracellular matrix that surrounds eggs and pre-implantation embryos and is required for in vivo fertility. A key event in successful fertilization is sperm binding to the surface of the ZP. It has been previously described that the hamster sperm binds mainly the outer region of the ZP which corresponds to the porous region in contact with the cumulus cells. Using ultrastructural cytochemistry approaches with an antibody developed against porcine ZP, this study shows that the pig ZP shares epitopes with some rodent species like hamster, rat and mouse. In the hamster, these epitopes are located mainly in the outer region of the ZP of preovulatory and ovulated oocytes. By means of biochemical approaches it was demonstrated that 1) the antibody is specific for the native hamster ZP3, 2) four different bands with a molecular weight of 67, 60, 48 and 38 kDa after Nlinked deglycosylation suggesting that the hamster ZP is formed by four proteins, and 3) the different composition observed in the outer region of the hamster ZP could be due to a specific supramolecular structure that makes some epitopes accessible for the antibodies. In summary, this study provides evidence that the different composition observed in the different regions of the ZP is mediated by a different organization of the components of the ZP produced during the oocyte maturation. This different organization could be responsible for the different sperm binding affinity observed for sperm to the outer region versus the inner region of the ZP.