Histology and histopathology Vol. 7, nº 1 (1992)
Ir a Estadísticas
Permanent URI for this collection
Browse
Recent Submissions
- 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 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 AccessSome morphological and histochemical features of the midgut myenteric plexus of the common european frog, Rana Esculenta(Murcia : F. Hernández, 1992) Gabriel, Robert; Fekete, Eva; Csoknya, MariaThe neuron morphology and distribution of four putative transmitters were investigated in the myenteric plexus of frog (Rana esculents) midgut. The gross morphology was revealed by NADH-diaphorase histochemistry, and the shape of the neurons by silver impregnation. Nerve cells had heterogeneous distribution: they either formed ganglia or placed as solitary neurons in the duodenum, while in the rest of the midgut only solitary neurons were observed. Three morphologically distinct cell types were rcvealed by silver impregnation: mainly type I and type I1 neurons cells were seen in the duodenum, while the rest of the intestine contained type I1 and I11 cells. Catecholamine fluorescence was revealed in nerve fibres in the duodenum, while few small nerve cells were observed in the small intestinal region. Acetylcholinesterase histochemistry showed strongly reactive nerve cells that were associated with the main fibre bundles in the duodenum. Only longitudinally oriented fibres and occasionally stained neurons were seen in the small intestine. Substance P immunocytochemistry revealed an extensive plexus, which contained a moderate number of stained perikarya in the full length of the midgut. Gammaaminobutyric acid showed non-uniform distribution in the two parts of the midgut: a stronger and more regular fibre staining was found in the duodenum then in the rest of the intestine. Ultrastructural observations demonstrated that intrinsic neurons received synaptic inputs from the profiles contained agranular vesicles. while ~PD- t y pper ofiles established close contacts with neurons. Both profile types formed close contacts with the smooth muscle cells. In spite of the several neuromorphological and ultrastructural similarities to the mammalian species, the transmitter distribution described here does not match in all respects to that found in the enteric nervous system of Offprint requests to: Dr. E. Fekete, Jate, Department of Zoology, Szeged, Egyetem U. 2., P.O. Box. 659, H-6722, Hungary those animals. This finding reflects the view, that the neurochemical coding system and the projection pattern within the plexus may vary considerably among different classes of vertebrates.
- 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.
- 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.