Histology and histopathology Vol. 6, nº 1 (1991)
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- PublicationOpen AccessThe alveolar pores of Kohn in young postnatal rat lungs and their relation with type II pneumocytes(Murcia : F. Hernández, 1991) Van Meir, FransIn order to obtain more information on the development, morphology and function of the pores of Kohn, the lungs of Wistar rats are studied during their early postnatal period, up to 3 weeks of age, by scanning and transmission electron microscopy. The substantial development of the interalveolar pores on days 14 and 21 coincides with the period of septal rearrangement when secondary interalveolar septa become lengthened and thinner. The high frequency of transseptal type 11 pneumocytes from day 7 onwards, and their typical localization near the pores of Kohn at this period of lung development especially suggests that type 11 pneumocytes are engaged in the formation of the pores of Kohn. During early lung development, the pores of Kohn seem to serve as passageways for alveolar macrophages.
- PublicationOpen AccessUltrastructure of mass of floccular substance in the parathyroid gland of golden hamster(Murcia : F. Hernández, 1991) Shoichi Emura; Shizuko Shoumura; Michiya Utsumi; Huayue Chen; Tomo Yamahira; Daisuke Ayakawa; Michio Arakawa; Hideo IsonoMass of floccular substance was observcd in the parathyroid glands of fetal, newborn and infantilc golden hamsters. Mass composed of floccular substances was spherical with no limiting membrane around it. It was located near the nucleus and the Golgi area, but was also observed in the peripheral cytoplasm. No ccll organelles were detected within area of mass.
- PublicationOpen AccessEffects of hypothyroidism on the ultrastructure of rat pancreatic acinar cells: a stereological analysis(Murcia : F. Hernández, 1991) Blanco-Molina, A.; González-Reyes, J.A.; Torre-Cisneros, J.; López-Miranda, J.; Nicolás, M.; Pérez-Jiménez, F.The morphological and stereological characteristics of the exocrine pancreas subcellular organelles from healthy and thyroidectomized rats have been studied. The acinar tissue from hypothyroid rats showed an interstitial edema and evidence of degenerative processes. Stereological parameters of zymogen granules were significantly reduced in thyroidectomized rats. The hypothyroidism induced degenerative changes in the pancreatic acinar cells as well as a decrease in the number and size of the zymogen granules. These modifications probably cause functional alterations.
- PublicationOpen AccessUltrastructural changes induced by a-sarcin in a human pulmonary tumor grown in naked mice(Murcia : F. Hernández, 1991) Mohamed-Ali, H.; Kolkenbrock, H.J.; Hecker-Kia, A.; Hinz, N.; Ulbrich, N.a-Sarcin is a cytotoxic polypeptide produced by Aspergillus giganteus. It suppresses protein synthesis in yeast and wheat germ extracts and has a purine-specific RNase activity. The substance has been tested for its antitumor properties in a series of induced tumor systems in mice such as sarcoma and carcinoma among others. Although some of the in vitro effects of a-Sarcin on certain cellular components have been elucidated, the biological effects leading to cellular damage are still obscure. In this work we analysed the morphological changes in tumor cells derived from human pulmonary adenocarcinoma heterotransplanted and grown in naked mice, induced shortly (24 hours) after a single intratumoral injection of U-Sarcin (0.4 mgltumor). The results obtained were: 1) swelling of mitochondria; 2) cell necrosis with partial removal of necrotic cells by phagocytosis; 3) thickening of interlobular connective tissue; 4) hyperplasia of globet-cell-like clear cells. The mode of action concerning these cellular changes is presently uncertain. In view of the severity of these structural alterations it seems conceivable that a-Sarcin may enter the cell undergoing interactions with different intracellular structures. This would require a selective membrane permeabilization, perhaps induced upon formation of complexes with negatively-charged membrane phospholipids
- PublicationOpen AccessUltrastructure of the rat hippocampus after isobaric respirative hyperoxia(Murcia : F. Hernández, 1991) Manthos, A.; Tsolaki, M.; Kaidoglou, K.; Alvanou, A.; Hatjinikolaou, K.; Hatjiagorakis, A.; Giala, M.; Foroglou, Ch.After exposing rats to an environment of isobaric h,v ~eroxia.th e ~iltrastructurala lterations of the L hippocampus were studied. No major alterations were found in the nerve cells. Of importante was the moderate osmiophilia and the spindle-like transformation of the mitochondria. Vacuolated synapses and neuraxons were found, containing amorphous material. Astrocytic perivascular end feet were found vacuolated in many places. Many endothelial cells of the capillaries presented high osmiophilia, which sonletimes prevented structural details. Quantitatively, the findings were proportionally related to the time of exposure in the pure oxygen atmosphere (24,48 and 65 hours)