Histology and histopathology Vol.17, nº 2 (2002)
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- PublicationOpen AccessEffects of cigarette smoke exposure on the utlrastructure of the golden hamster parathyroid gland(Murcia : F. Hernández, 2002) Yano, R.; Hayakawa, D.; Emura, S.; chen, H.; Ozawa, Y.; Taguchi, H.; Shoumura, S.Cigarette smoking has been identified as one of the risk factors to induce osteoporosis. However, we find no study on the morphology of the parathy r o i d gland under smoking exposure. We studied the ultrastructure of the parathyroid gland, lung and femur of the golden hamster exposed to cigarette smoke. Fourweek- old male hamsters were housed in a plastic case (48x31x30 cm) and were exposed to cigarette smoke for 12 weeks, 5 minutes exposure, 4 times a day, 4 days a week. There were no differences in serum calcium level and the whole bone mineral density between the control and the smoke-exposed groups. In the parathyroid gland of the smoke - exposed animals, the Golgi complexe s associated with many prosecretory granules were well d eveloped and many secretory granules were located near the plasma membrane. Large lipid-like inclusion bodies were observed in the alveolar macrophages of the smoke-exposed animals. The femur morphology showed a wider area of resorbing surface in the smoke-exposed group than in the control group. From these findings, it is conceivable that the secretory activity of the p a r a t hyroid gland was stimulated with cigarette smoke exposure.
- PublicationOpen AccessImmunogold localization of mitochondrial aspartate aminotransferase in mitochondria and on the cell surface in normal rat tissues(Murcia : F. Hernández, 2002) Cechetto, J.D.; Sadacharan, S.K.; Berk, P.D.; Gupta, R.S.Mitochondrial aspartate aminotransferase (mAspAT) (E.C. 2.6.1.1), an important enzyme in amino acid metabolism, is identical to a fatty acid-binding protein (FA B Pp m) isolated from plasma membranes of several cell types. Employing a monospecific polyclonal antibody to rat mAspAT, we have used immunogold electron microscopy to study the subcellular distribution of mAspAT in various mammalian tissues. Immunogold labeling of rat tissue sections embedded in LR Gold resin showed strong labeling of mitochondria in all tissues examined (viz. live r, pancreas, pituitary, spleen, heart, kidney, submandibular gland). In addition, strong and specific labeling was also observed at a number of non-mitochondrial sites including various locations in k i d n ey, such as on cell surface in distal tubules and cortical collecting ducts, in condensing vacuoles, along cell boundaries between adjoining cells, and in endothelial cells lining capillaries in the glomerulus. S u r face labeling due to mAspAT was also seen in arteriolar endothelial cells and in lymphocytes. These findings support the previous identification of mAspAT as both a mitochondrial enzyme and a plasma membrane protein. It is suggested that in accordance with its established role in other cells and tissues, the surfa c e - located mAspAT in kidney and endothelial cells is i nvo l ved in the fatty acid transport process. The duallocalization of mAspAT, as well as a large number of other mitochondrial proteins (viz. Hsp60, Hsp10, Cytochrome c, TRAP-1 and P32 (gC1q-R)) in recent studies, within both mitochondria and at various specific extramitochondrial sites raises fundamental questions about the role of mitochondria in cell structure and function, and about the mechanisms that exist in normal cells for protein translocation from mitochondria to other compartments. These results have implications for the role of mitochondria in apoptosis and different diseases.
- PublicationOpen AccessPressure volume curve and alveolar recruitment/ de-recruitment. A morphometric model of the respiratory cycle(Murcia : F. Hernández, 2002) Escolar Castellón, J.de D.; Escolar, M.A.; Guzmán, J.; Roqués, M.H y p o t h e s i s : The changes in pulmonary volume taking place during respiration are accompanied by the opening and closing of the alveoli, with the number of alveoli open, at the same transpulmonary pressure (TPP) differing, depending on whether the lung is insufflated or deflated. Material and methods: Seventy 344 Fischer rats divided into five groups. Group 1 lungs were fixed by instilling 10% formalin through the trachea to a pressure of 25 cm H2O. The lungs of the next four groups were air- fi l l e d and fixed via the pulmonary artery: group 2 lungs were fixed in inflation at 10 cm H2O TPP; group 3 lungs were fixed in inflation at 20 cm. H2O TPP; the lungs of groups 4 and 5 were fi xed in deflation and, therefore, were inflated with air up to 27 cm. H2O to drop to 20 cm in group 4 and to 10 cm in group 5. The lungs were processed for light microscopy, carrying out a morphometric study. The results were statistically processed. Results: The lungs insufflated with liquid fixative at 25 cm of TPP reached higher values in the va r i a b l e s Pulmonary Volume, Internal Alveolar Surface (IAS) and Number of Alveoli, being statistically signifi c a n t (p<0.05) in comparison with the other four groups. In the lungs fixed in deflation, the pulmonary volume, IAS and number of alveoli were greater than in those fixed in inflation. The lungs fixed to 20 cm in deflation displayed s i g n i ficant statistical differences compared with those fi xed to 20 cm in inflation. The IAS and number of a l veoli gave good rates in relation with the pulmonary volume (r³ 0.65). Three variables were used to measure the size of the alveoli, alveolar cord, alveolar surface and Lm, but none showed significant modifications. Conclusion: This study supports the hypothesis that changes in lung volume are related to the increase/decrease in the number of alveoli that are open/closed and not to the modification in the size of the a l veoli. Alveolar recruitment is the microscopic expression of pulmonary hysteresis, since the number of alveoli open in deflation is greater than the number open during inflation.
- PublicationOpen AccessEffect of heparin and antivenom on skeletal muscle damage produced by Bothrops jararacussu venom(Murcia : F. Hernández, 2002) Calil-Elias, S.; Martinez, A.M.B.; Melo, P.A.We examined the effect of treatment with heparin and polyvalent antivenom on mice muscle Extensor digitorum longus (EDL) regeneration, after damage induced by injection of B o t h rops jara ra c u s s u crude venom over the muscle of the right posterior limb. The mice were separated into groups and each group received treatment, by intravenous route with either high molecular weight heparin (H), low molecular weight heparin (LMWH), polyvalent antivenom (PAV) or with the combination of PAV plus H or PAV plus LMWH at 15 minutes and 4 hours after the injection of the venom. Myotoxicity was measured by the increase in plasma creatine kinase (CK) activity at two hours after the injection of the venom. The histological changes in EDL at 1, 3, 7 and 21 days after the injection of the ve n o m were analyzed by light microscopy. In each group the normal and regenerated muscle fibers were quantifi e d using Scion Image computer program. We also evaluated in vitro, the influence of these substances in the proteolytic and phospholipase activities of the ve n o m . Heparins decreased the proteolytic activity of the venom but did not affect its phospholipase activity. However the PAV antagonized both activities. PAV and its combinations showed antimyotoxic activity, according to the magnitude of CK plasma levels. At 21 days the r egeneration was observed in all animals, also in those that received only the venom. All treatments, ex c e p t LMWH, promote a significant increase in the number of muscle fibers.
- PublicationOpen AccessCD34+ stem cells in chronic myeloproliferative disorders(Murcia : F. Hernández, 2002) Thiele, J.; Kvasnicka, H.M.Contrasting the wealth of information that is available about various biological and therapeutic aspects of human CD34+ stem cells, little data ex i s t concerning their quantity and dynamics as well as their mutual relationships with other hematopoietic constituents in the bone marrow of patients with chronic m y e l o p r o l i f e r a t ive disorders. In comparison with a control group frequency of progenitors is signifi c a n t l y increased in chronic myeloid leukemia (CML). Following different therapeutic modalities their quantity reflects therapeutic eff i c a cy (responder and nonresponder patients) and therefore exerts a predictive value regarding acceleration and blastic crisis. The s i g n i ficant correlations between fiber content and number of these precursors elucidates the complex interactions between stroma and progenitor cell d i fferentiation and maturation. Fo l l owing allogeneic bone marrow transplantation there is a rapid recovery of the CD34+ stem cell population in the first month. A higher number of these cells is related with graft size, an earlier independence for platelet transfusion and a more extended regeneration of erythro- and megakaryopoiesis. The slight increase in reticulin fibers in these patients may be associated with the complex and so far illd e fined pathomechanism of homing (adherence to the fibrous matrix). In idiopathic myelofibrosis (IMF) an increased number of CD34 + stem cells is found predominantly in the early (prefibrotic or mild fibrotic) hypercellular stages and probably indicates a higher p r o l i f e r a t ive activity of the precursor cell pool. According to sequential biopsies most patients with early IMF that later evolved into an overt fibrosclerotic stage usually display a reduction of progenitor cells during the development of myelofibrosis. The unequal d i s t r i bution of CD34+ stem cells in the bone marrow versus spleen in IMF (advanced fibrosclerotic stage) is in support of the currently discussed hypothesis of splenic filtration and concentration of precursor cells as an essential feature of myeloid metaplasia. Rega r d i n g prognosis in CML a higher amount of CD34+ stem cells is significantly associated with an unfavorable survival and thus confirms the assumed implication of an accelerated phase of disease at onset. On the other hand, in polycythemia vera (PV) and IMF a low number of progenitors is probably due to a decreased proliferation rate (reduced hematopoietic turnover index) and therefore reflects a reduction in the regenerative capacity of hematopoiesis. For this reason, a presumptive defect in the recovery of normal and clonally transformed stem cells is speculated to add to the worsening of prognosis by causing the well-known bone marrow insufficiency in terminal stage PV and IMF.