Histology and histopathology Vol. 9, nº 1 (1994)
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- PublicationOpen AccessPulmonary response to bovine albumin. A morphometric study in rats(Murcia : F. Hernández, 1994) Escolar Castellón, J.de D.; Alfaro, E.; Roche Roche, P.A.; Almajano, C.; Gallego, B.The following hypothesis is proposed: that hypersensitivity pneumonitis (HP), experimentally induced in rats, is the cause of a thickening in the alveolar wall, a decrease in the size of the alveole, hyperplasia in the bronchus-airociated lymphoid tissue (BALT) and hypertrophy in the goblet cells. Wistar rats were classified into two different groupi, namely, non-treated animals and animals exposed to bovine albumin (BA). A morphometric study was carried out and the following variables were quantified: a) percentage of lymphocytes. neutrophils and alveolar macrophages of the bronchio-alveolar lavage (BAL); b) the interstice of the alveole, the alveolar chord length. the alveolar wall thickness and the number of alveolar macrophages with hemosiderin within its cytoplasm; c) the size of lymphatic area (LA) in BALT, the length of the lymphatic epithelium (LEp) in BALT and the percentage of goblet cells in the bronchial epithelium. The following results were obtained from the animals exposed to BA: 1) a significant increase in both lymphocytes and neutrophils of BAL, and of alveolar macrophages with hemosiderin in its cytoplasm; 2) a significant thickening of the alveolar walls and the BALT elements, which confirms the above mentioned hypothesis; 3) a significant increase in the alveolar chord and a significant decrease in the number of goblet cells of the bronchus, which contradicts the above mentioned hypothesis. The increase in alveolar macrophages with hemoiiderin is related to an increase in the capillary alveole perrneability, which, together with the variations in the BAL formula, lead us to consider the existence of an inflammation in the interstitial alveole; this interstitial alveole inflammation explains the alveolar wall thickening and the BALT hypertrophy.
- PublicationOpen AccessTopographic distribution and quantitative analysis of retrograde-labelled cells in the substantia nigra following administration of fluoro gold in the caudate putamen nucleus(Murcia : F. Hernández, 1994) Juanes, J.A.; Bentivoglio, M.; Riesco, J. M.; Chen, S.; Vázquez, R.The organization of the efferent projections of the substantia nigra following the irijection of 0.4 pl of 2% Fluoro Gold into the caudate-putamen nucleus of rats of both sexes was studied. After a survival period of 77 h. the greatest number of labelled cells was visuali~ed in ihe substantia nigra, with lower numbers in adjacent structures (ventral tegrnental area. zona incei-ta and ~rredial leinniscus). The cclls featured an intensely fluorescent goldcoloured soma and were varied in .shape (round or n\:al); short sinuous projectioris arose out of thein. corresponding to the dendrites and axons of the neurons. ln the statistical study. no significant differences were observed between r-iiales and females. A sirrrilar pattern of distribution was found rangirig Sr0111 ihe rostral to the caudal regions of the substantia niyra. occupying the whole of the extent of the suhstantia nigra; this distribution was most predominant in the rostro-caudal transition of the pars compacta of the substantia nigra.
- PublicationOpen AccessThe role of the proteasome in cellular protein degradation(Murcia : F. Hernández, 1994) Driscoll, J.Eukaryotic cells contain a major intracellular proteolytic activity known as the proteasome. The proteasome is a strongly conserved cylindrical structure of high molecular weight (650 kDa, -20 S) and desmonstrates multiple endopeptidase activities. The general structural, biochemical and genetic features of the proteasonie are conserved from archaebacteria through yeast to humans. This structure fulfills an essential role by functioning as the proteolytic core of a 26 S multienzyme complex responsible for the energydependent degradation of ubiquitinated proteins. The bulk of intracellular proteolysis appears to be through the ubiquitin-dependent pathway. Incorporation of the proteasome into the 26 S niultienzyme complex appears to confer both a specificity for ubiquitinated proteins as well as a nieans to tightly regulate proteolytic activity. Thus, one function of the proteasome is required for the degradation of either abnormal or certain regulatory proteins by the ubiquitin pathway. Proteasoine subunits appear to be encoded by a related gene family as defined by extensive sequence similarities. The gene products are confined to either of two general classes: a-type which appear to be structural and 8-type which may be catalytic. Genes encoding at least two proteasome subunits map to the Ma-jor Histocompatibility Complex. Accurnulating evidence points to the proteasome (or a specialized form) participatirig in the cytosolic degradation of these viral proteins upon cellular infection. Through a previously unforseen mechanisin. it appears that the products from the digestion of the viral proteins may be rescued from further digestion to amino acids and shuttled from the cytoplasm through the endoplasniic reticulum to the cell surface where they serve as antigenic peptides for recognition by the immune system. The proteasome may have been recruited by the immune system to serve as the cytosolic activity responsible for generating these antigenic peptides. The proteasome may function in the ubiquitindependent degradation of not only certain self-proteins but may fulfill a second essential role in the degradation of proteins originating from viral infection
- PublicationOpen Accesscoexistence of serotonin and cholecystokinin in paraneurons of the foetal sheep lung(Murcia : F. Hernández, 1994) Balaguer, L.; Romano, J.; Ruíz-Pesini, P.The coexistence of serotonin and cholecystokinin was studied in foetal sheep lungs at pseudoglandular stage of developtnerit by light inicroscopic itninunohistochemistry. The coexistence was examined by staining consecutive sections with the different antibodies. Serotonin and cholecystokinin iniinunoreactivity was found within consecutive sections of most bronchopultnonary neuroepithelial bodies and in consecutive sections of the same intrapulmonary autonomic gariglia.
- PublicationOpen AccessHistopathological characterization of photochemical damage in nervous tissue(Murcia : F. Hernández, 1994) Van Reempts, J.; Borgers, M.This paper discusses histological and ultrastructural changes produced by dye-sensitized photoreactions in the central and peripheral nervous system. Particular attention has been given to morphological outcome in experimental models which reproduce widespread clinical pathologies, e.g. stroke, spinal cord injury and peripheral neuropathy. Evaluation of structural alterations may not only help to characterize the evolution of these disease processes but also allow us to study possibilities of therapeutic intervention.