Histology and histopathology Vol. 7, nº 3 (1992)
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- PublicationOpen AccessA scanning and transmission electron microscopic study of the membranes of chicken egg(Murcia : F. Hernández, 1992) Tan, C.K.; Chen, T. W.; Chan, H.L.; Ng, L.S.Questions regarding the structure of the inner and outer shell membranes of the chicken egg were addressed in this study by correlating observations from light microscopy and scanning and transmission electron microscopy. The egg membrane had a limiting membrane, which measured .9 to .15 pn in thickness and appeared to be a continuous and an impervious layer, but the shell membrane did not. Under the SEM, each membrane was seen to be made up of severa1 fibre layers. In the tear preparations viewed under the SEM two layers were observed in the egg membranes and three to five layers in the shell membrane, with an apparent plane of cleavage between each layer. Each fibre was made up of a central core and an outer mantle layers. The central core was perforated by channels which measured .O8 to 1.1 1 pn in diameter and ran longitudinally along the length of the fibre. Between the mantle layer and the fibre core was a gap or cleft measuring between .O3 to .07pn. The diameter of the fibres of the inner layer of the egg membrane ranged between .O8 to .64pn, whereas those of the outer layer of the same membrane ranged from .O5 to 1.11 p.m. Fibres in the shell membrane ranged from . l l to 4.14 pm diameter.
- PublicationOpen AccessStudies on the interaction between titin and myosin(Murcia : F. Hernández, 1992) Wang, Seu-Mei; Chung-Jiuan Jeng; Mu-Chien SunThis study examines the interaction of titin and mysoin. In order to analyze the domains of myosin contributing to the binding for titin, we conducted a solid phase binding assay. Different portions of mysoin (heavy chains, light chains and myosin fragments ) were coated on the microtiter wells and reacted with biotinylated titin. Then the binding of biotinylated titin to these polypeptides was detected by using the avidinbiotin- peroxidase method. The results demonstrated that light meromyosin and subfragment 1 were the major domains of myosin interacting with titin. Titin fragments obtained by trypsin digestion were allowed to react with myosin in an affinity column, and the bound fragments were isolated by an acidic elution. Immunoblot analysis of mysoin-bound titin fragments revealed that an A-band domain of titin was responsible for the binding of myosin. In addition, biotinylated titin labelled the outer A-bands and Z-bands in intact myofibrils, thus confirming the in situ binding of titin to myosin.
- PublicationOpen AccessCarbohydrate cytochemistry of bonnet monkey (Macaca radiaca) nasal epithelium. Response to ambient levels of ozone(Murcia : F. Hernández, 1992) Dimitriadis, V.K.The main purpose of this study was to determine whether exposures to ambient levels of ozone induced changes in the carbohydrate content in the anterior nasal cavity of bonnet monkey. Monkeys were exposed to 0.00. 0.15, or 0.30 ppm of ozone for 6 or 90 days, 8 hours / day. Monkeys treated for 90 days to 0.15 or 0.30 ppm of ozone displayed damaged ciliated cells and a new cell type in their respiratory nasal epithelium, the «intermediate» cells possessing morphological characteristics of both ciliated and secretory cells. Characterization of the secretory cell carbohydrates with the PA-TCH-SP, HID-TCH-SP and LID-TCH-SP techniques indicated the existence of periodate-reactive sulfated and carboxylated polysaccharides in both treated and control monkeys. Ozone-inhalation, however, induced the appearance of a large number of mucous cells with dilated cisternae of rough endoplasmic reticulum compared to controls, which reacted negatively for sugar presence. In addition, in the respiratory epithelium ozone induced the increase of cells with intracytoplasmic lumina containing material reacted positively for sulfated and carboxylated polysaccharides.
- PublicationOpen AccessIn vitro analysis of the cellular resistance to chemotherapeutic BCNU(Murcia : F. Hernández, 1992) Caballero Navarro, A.; Conde Guerri, B.; Sinués Porta, E.; Boada Apilluelo, E.; Alcalá Arellano, A.Our asays in vitro show that BCNU inhibits cell proliferation in the Ca cell line experimental glioma and is dose-dependent, starting from 0.5 pg/ml of the drug with just an hour of exposure. For every tested concentration of BCNU it is shown that, from the fifth day after exposure, cellular resistance appeared. This resistance is justified by the capacity of cell DNA reparation. A study of the clonogenic capacity of the Ca cells exposed to BCNU also shows the appearance of cellular resistance for doses of 0.5 pglml and 1 pglml. Furthermore, the exposure of Ca cell cultures to BCNU at these levels produces a cellular evolution towards more differentiated morphological patterns.
- PublicationOpen AccessKupffer cells and PlMs in acute experimental African Swine Fever(Murcia : F. Hernández, 1992) Carrasco, L.; Fernández, A.; Gómez-Villamandos, J. C.; Mozos, E.; Méndez, A.; Jover, A.An ultrastructural study of Kupffer cells and pulmonary intravascular macrophages (PIMs) of healthy and African Swine Fever (ASF)-infected pigs was carried out. A vascular perfusion method was performed in order to obtain an optimal intravascular morphology and tissue fixation. The infection developed acute ASF lesions in both organs. Both Kupffer cells and PIMs were studied at different stages of infection. The differences observed in both macrophagic cells from uninfected and infected tissues are shown and discussed.