Histology and histopathology Vol. 9, nº 1 (1994)
Ir a Estadísticas
Permanent URI for this collection
Browse
Recent Submissions
- 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.
- PublicationOpen AccessHeterogeneous immunoreactivity of frozen human benign and malignant breast lesions to C-MYC and C-Ha-ras cellular oncogenes(Murcia : F. Hernández, 1994) pechoux, C.; Chardonnet, Y.; Chignol, M.C.; Noël, P.C-myc and c-Ha-ras oncoprotein expression was studied by immunohistochemistry and gene detection by in situ hybridization on serial frozen sections of 32 breast lesions (19 benign biopsies and 13 infiltrating carcinomas). C-myc protein was expressed in 15/19 benign and 12/13 malignant lesions; c-myc gene was detected in 17/19 benign and 13/13 malignant lesions. Although a higher proportion of benign biopsies (819) showed more than 50% of protein-positive cells than malignant specimens, this cannot predict the outcome of a lesion. Conversely, p2 1 ras protein was expressed only in 2/19 benign lesions and in most cases of grade 1 to 111 carcinomas. The c-Ha-ras gene was always detected in a small percentage of cells, in both benign and malignant lesions. The results obtained with atypical hyperplasia, a doubtful proliferating lesion, suggests that p21 c-Ha-ras protein expression is not restricted to breast carcinomas. Although Southern blot is commonly considered as a very sensitive technique for oncogene analysis, no amplification of c-myc and c-Ha-ras gene has been demonstrated either in benign or malignant lesions. The detection, on serial frozen sections, of proteins and DNA of c-myc and c-Ha-ras, showed a possible amplification of the c-myc and c-Ha-ras genes in various benign and malignant lesions.
- 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 AccessEffects of in utero exposure to low dose ionizing radiation on development in the rat(Murcia : F. Hernández, 1994) Bruni, J.E.; Persaud, T.V.N.; Froese, G.; Huang, W.Most studies of in utero effects of ionizing irradiation involve high doses and examination at postnatal intervals. Little information is available on the effects of low levels of ionizing radiation on embryogenesis. The developmental effects of in utero exposure to 50 cGy gamma radiation on gestational day-9.5 was investigated using Sprague- Dawley rats. Irradiated rats and appropriate controls were killed at prenatal intervals of 4h, 48h and 10 days after exposure. Fetuses were examined for abnormalities and random samples of tissues were prepared for microscopic study. With the exception of the neuroepithelium, no histopathological changes were observed in embryos 4h after exposure to 50 cGy. In irradiated embryos, mitoses were reduced within the neuroepithelium; pyknosis and some necrosis of cells were apparent at this gestational interval. Among the gross developmental abnormalities observed in embryos 48h after irradiation, excessive flexion of the embryo and abnormal flexion of the head were the only ones that appeared to be radiation-induced. The mean numerical score (47.310.2, controls; 42.410.1, irradiated) for 17 morphological parameters examined in fetuses at this gestational period compares favorably with other studies. Controls, however, showed greater variability in the extent of development of their forebrain, olfactory system, midbrain, hindbrain, and caudal neural tube. In al1 cases, there was evidence of slower development in these regions compared to their irradiated counterparts. At term. no significant differences in litter size or resorption rates were observed in irradiated animals compared to the controls, but there was a higher incidence of defective eye development, spinal curvature and visceral anomalies. In utero exposure to 50 cGY gamma-radiation during the period of early organogenesis can produce some irreversible defects that are discernible at term.
- PublicationOpen AccessUltrastructure of spontaneous glomerular lesions in Syrian hamsters of APA strain(Murcia : F. Hernández, 1994) Yamanouchi, J.; Yasoshima, A.; Han, J.S.; Itagaki, S.; Doi, K.Electron microscopic observations were carried out on the spontaneous glomerular lesions in male APA hamsters from 3 to 12 months of age. Until 6 months of age, focal expansion of mesangial region due to an increase of matrix material and mesangial cells was characteristic, and segmental thickening of capillary basement membrane and partial effacement of foot processes of podocytes were also sometimes observed. At 12 months of age, although al1 of these changes became more severe, the most prominent alteration was found in podocytes, which showed various degenerative changes. No deposition of amyloid fibrils was detected in any portion of the glomerulus.