Histology and histopathology Vol. 7, nº 1 (1992)
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- PublicationOpen AccessPostnatal maturation of the parenchymal cell types in the rabbit pineal gland(Murcia : F. Hernández, 1992) García-Mauriño, J.E.; Boya, J.An ultrastructural study on the maturation of the parenchymal rabbit pineal cell types from the first postnatal day up to 120 days is presented. Two main cell types are distinguished from the first 24h of postnatal life. Pinealocytes of the types 1 and 11 display different developmental degrees. Both immature cell types are arranged in groups. In addition, type 11 pinealocytes form rosette-like structures. Both cell types progressively become isolated and display cell processes. The nucleus and the cytoplasm of type 1 pinealocytes are barely electrondense. During the postnatal period, the number of cytoplasmic organelles, cell processes and terminal clubs increase progressively. Terminal clubs are frequently seen near blood vessels. After 30 days, type 1 pinealocytes show characteristics of adult pinealocytes. However, the maturation of rnost type 1 pinealocytes does not complete until the 90th postnatal day. Type 11 pinealocytes present a fairly electrondense nucleus and cytoplasm. Mature forms can be seen after the 5th postnatal day. During the postnatal period, a close relationship is determined arnong type 11 pinealocytes and cell processes and terminal clubs of type 1 pinealocytes.
- PublicationOpen AccessUltrastructural findings of congenital dyserythropoietic sickle cell beta thal-associated anemia(Murcia : F. Hernández, 1992) Dell`Orbo, Carlo; Marchi, Antonietta; Quacci, DanielaThe ultrastructural findings of erythroblasts and reticulocytes in one case of congenital dyserythropoiethic anemia (CDA) associated with a haemoglobinopathy, sickle cell beta thalassemia minor (Type V CDA), is described. The observations can be summarized as follows: 1) A lot of large breaks are present in the erythroblast nuclear envelope. 2) Nuclear membrane evaginations are filled with dense loose chromatin. 3) Electron-transparent areas (moth eaten chromatin) are evident in dense chromatin. 4) Electron-dense granular material, related to altered haemoglobin chain storage, is evident in the nucleus and in the cytoplasm. 5) Iron deposits are present in mitochondrial matrix. 6) Myelinic figures are present in reticulocyte cytoplasm. For the first time the ultrastructural findings in this type of associated CDA are described and related to the double origin of clinical symptoms.
- PublicationOpen AccessEffects of white light on the pineal gland of the chick embryo(Murcia : F. Hernández, 1992) Aige-Gil, Vicente; Murillo-Ferrol, NarcisoChick embryos were directly exposed to a source of white light during incubation and sacrificed before hatching. The light caused a number of teratological effects such as high mortality, delay in development, celosomy, hepatomegaly, auricular dilation and micrognatia. The pineal gland of the illuminated embryos showed an increase in number and size of the intracytoplasmic lipid droplets of the follicular pinealocytes. These findings suggest that the pineal gland of the chick embryo is sensitive to light.
- PublicationOpen AccessRadiation retinopathy: electron microscopy of retina and optic nerve(Murcia : F. Hernández, 1992) Krebs, Ingeborg P.; Krebs, Wolf; Merriam, John C.; Gouras, Peter; Jones, Ira S.A 4 112 year old female was treated for embryonal rhabdomyosarcoma of the left orbit in 1975 with radiation (59.5 Gy in 5 weeks), followed by chemotherapy. An electroretinogram (ERG) in March, 1988 revealed cone responses 3% of normal and no rod responses in the left eye, and normal responses in the right eye. The eye was enucleated in April 1988. In the fovea no choroidocapillaris was seen at the intact Bruch's membrane, and the pigment epithelium was preserved only in small patches. No photoreceptor cells were seen in the areas devoid of pigment epithelial cells. The parafoveal and peripheral (30° eccentricity) retina was better preserved. The thickness of the layer of rods and cones and of Henle's fiber layer was reduced. Very few outer segments were present. Macrophages had invaded the retinal tissue in moderate numbers. The retinal vessels were ensheathed by several layers of collagen fibrils. The spatial densities of pigment epithelial, cone, rod, and bipolar cells had been reduced. The optic nerve contained a total number of 1,022,000 nerve fibers
- PublicationOpen AccessElectron microscopic observations of elastic fibres in the lung and aorta of tight-skin and beta-aminopropionitrile-fed mice(Murcia : F. Hernández, 1992) Masumi Akita; Seong Ho Lee; Katsuji KanekoThe lung of the tight-skin (TSK) mouse was characterized by enlargement of the air spaces. Elastin in the alveolar walls of the TSK mouse exhibited fragmentation. The aorta of the TSK mouse was characterized by marked hyperplasia of loose connective tissue in the adventitia. Collagen fibres and ruthenium red-positive materials were markedly increased. Microfibrils surrounding elastin in the adventitia of the aorta were not clear in the TSK mouse. In the lung of the beta-aminopropionitrile (BAPN)-fed mouse. enlargement of the alveolar air spaces was not prominent compared with the TSK mouse. Elastic fibres in the alveolar walls did not show the fragmentation observed in the TSK mouse, and microfibrils surrounding elastin were clearly observed. However. elastic laminae in the media of the BAPNfed mouse aorta were swollen and fragmented. Elastic fibres in the adventitia exhibited a normal appearance and microfibrils surrounding elastin in the adventitia were clearly observed. The results suggest that the mechanism of the connective tissue abnormality in the TSK mouse is different from that of BAPN. which inhibits the activity of lysyl oxidase. The abnormality of elastin and microfibrils surrounding elastin in the TSK mouse probably plays a role in the deformity or degradation of elastic fibres and the structural changes of the lung.