Histology and histopathology Vol. 2, nº 2 (1987)
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- PublicationOpen AccessLight and electron microscopic study of fetal lung following maternal exposure to methylmercuric chloride(Murcia : F. Hernández, 1987) Curle, D.C.; Ray, M.; Persaud, T.V.N.Varying dose levels of methylmercuric chloride (MMC), 1000 ppm (5 mg through 15 mglkg of body weight), were administered via an intragastric tube to pregnant ICR SwissIWebster mice on day 9 of gestation. The animals were killed on gestational day 18 and the fetuses removed. Fetal lung sections were processed for light and electron microscopy. A group of animals treated with physiological saline in a similar mannner served as the controls. The fetal lungs from treated animals were hypoplastic and retarded in development. The severity of pulmonary changes increased with the dose-levels of MMC. Vacuolation and lysis of mitochondria were seen in fetal lungs. Mitochondrial damage increased in severity with doselevel of methylmercuric chloride.
- PublicationOpen AccessEndocrine cells of the gastric mucosa of Rana temporaria L.(Murcia : F. Hernández, 1987) Díaz de Rada, O.; Sesma, P.; Vazquez, J.J.The endocrine cells of the gastric mucosa of Rana temporaria have been studied according to the ultrastructure, the staining properties of the granules with Masson Fontana's and Grimelius' silver methods, silver impregnation of Davenport on deplasticised semithin sections and immunocytochemical techniques. Seven different types of endocrine cells have been described. Six were regarded as belonging to known types: G, A, EC, ECL, D and P cells. One type was considered as unclassifiable.
- PublicationOpen AccessGNRH induces activation of Leydig-like cells in Pleurodeles waltlii. A morphometric study(Murcia : F. Hernández, 1987) Moya, L.; Guerrero, F.; Navas, P.; García-Herdugo, G.The ultrastructure of the interstitial cells of the glandular tissue of Pleurodeles waltlii was studied in testis of animals obtained in early breeding season (January) under gonadotropic releasing hormone (GNRH) treatments and controls. These cells (parenchimal or Ledyig-like cells) displayed the structural characteristics of steroid-producing cells. GNRH administration for 24 hours induced a significant decrease of both medial volume and volume density of lipid droplets. On the other hand, cell volume, nucleus. mitochondria, mitochondrial cristae and tubules of smooth endoplasmic reticulum were increased. The surface density of mitochondrial cristae was also increased
- PublicationOpen AccessAutoradiographic investigation of circadian rhythms in alveolar bone periosteum and cementum in young mice(Murcia : F. Hernández, 1987) Tonna, E.A.; Singh, I.J.; Sandhu, H.S.This report presents circadian rhythms in cell proliferation of alveolar bone periosteum and cementum of the maxillary first molars of male 5-week-old BNL, Swiss albino mice which were maintained on a 12 hr light1 dark cycle. Mice were injected with 3H-TDR (lucilgm. body wt.) 1 hr prior to sacrifice and killed every 3 hrs for 24 hrs starting at 9 a.m. Maxillae were decalcified, routinely processed histologically and autoradiographs prepared. Cell labeling indices of alveolar bone and cementum mesial to the first molar were determined. Alveolar bone periosteal and cemental cells show circadian rhythm in their DNA synthetic processes. Peaks in percent labeling exhibit higher values than previously reported for nontraumatized, normal dental periosteum and cementum. While the outer periosteum reveals a single 24 hr peak (6 p.m.), inner periosteum and cementum reveal two ultradian peaks 9 to 12 hrs apart involving both light and dark periods. Rodents are nocturnal, but high peaks are also evident in the light periods, consequently, not all peaks are synonymous with the period of animal activity and feeding. Although the single daylight peak of the outer periosteum may indicate growth of that surface at night to about noon, the double peaks exhibited by inner periosteum and cementum indicate lightldark, continuously active surfaces in terms of DNA synthesis and growth
- PublicationOpen AccessThe protective effects of a prostaglandin without antisecretory properties aginst ethanol-induced injury in the rat stomach, a histologic study(Murcia : F. Hernández, 1987) Schmidt, Carmen L.; Henagan, Julia M.; Mitchell, Philip A.; Smith, Gregory S.; Miller, Thomas A.This study examined the effect of 2-acetyl-2- decarboxy-15(S)-15 methyl PGF,, (PGF,,) on ethanol (EtOH) induced injury in the rat stomach to determine if a PG analogue devoid of antisecretory properties could confer full or partial gastric mucosal protection. Rats were orally administered saline or PGF,, in a dose of 0.5 or 5.0 mg1Kg. Thirty minutes later animals received varying concentrations (i.e. 25%, 50%, and 100%) of EtOH orally. Five minutes following EtOH exposure, they were killed and samples taken from identical regions of the glandular mucosa for microscopic evaluation. All concentrations of EtOH tested damaged the gastric epithelium. The injury induced by 25% EtOH was almost exclusively confined to the surface epithelium and was not altered by either dose of PGF,,, pretreatment. In contrast, both 50% and 1(10% EtOH elicited comparable damage to the gastric mucosa involving both the deep and superficial mucosa of virtually the entire epithelium. The deep injury induced by these two EtOH concentrations was prevented by both the low and high dose of PGF,,. Of particular importance the 5.0 mg dose of PGF, provided complete protection (i.e. both superficial and deep) to as much as 50% of the mucosa exposed to 50% or 100% ethanol. These findings indicate that PGF?, possesses ~~cytoprotectivep*r operties involving both the superficial and deep epithelium that are dose related.
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