Histology and histopathology Vol.15, nº 2 (2000)
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- PublicationOpen AccessMineralization of human premolar occlusal fissures. A quantitative histochemical microanalysis(Murcia : F. Hernández, 2000) Campos, Antonio; Rodriguez, I.A.; Sanchez-Quevedo, M.C.; García, J.M.; Nieto-Albano, O.H.; Gómez de Ferraris, M.E.The mechanisms of cariogenesis in occlusal fissures remain elusive because of limited information about fissure structure and wall mineralization. The purpose of the present study was to determine the correlation between morphological patterns in occlusal fissures in human premolars and quantitative histochemical patterns of mineralization in the walls of these formations. We used scanning electron microscopy and quantitative X-ray microanalysis with the peak-tolocal background ratio method and microcrystalline calcium salts as standards. We distinguished three morphological patterns of fissures in scanning electron microscopic images. The wall of the fissures was less mineralized than the control enamel in all three types of fissures. Because the fissure walls are hypomineralized, we suggest that practicing dentists should take into account the degree of mineralization when they are preparing the fissures for the application of sealant.
- PublicationOpen AccessComparative study of tumor angiogenesis and immunohistochemistry for p53, c-ErbB2, c-myc and EGFr as prognostic factors in gastric cancer(Murcia : F. Hernández, 2000) Sanz Ortega, J.; Steinberg, S.M.; Moro, E.; Saez, M.; Lopez, J.A.; Sierra, E.; Sanz Esponera, J.; Merino, M.J.Gastric cancer (GC) continues to be a highly aggressive malignancy with poor prognosis and low survival rates. The survival of patients with GC depends mainly on the stage of the disease, with early GC having a 5 year survival of 90-100% and advanced tumors a 5 year survival of 15-25%. The role of other prognostic factors in these tumors is still under investigation. 28 gastric dysplasia, 45 Early GC and 98 Advanced Gastric Cancers were evaluated for expression of the oncogenes p53, c-ErbB2, c-myc and the EGFr in paraffin-embedded material utilizing Avidin-Biotin immunohistochemistry techniques. In 34 cases of GC microvessel density (MVD) was determined in CD34 stained sections. Statistical correlations with stage, histologic type, differentiation degree, location, size, ploidy patterns and overall survival were done. The Mantel-Cox test was performed to evaluate which factors had an independent prognostic value. Both, tumor angiogenesis and p53 protein expression were statistically associated (95% confidence intervals) with overall survival in patients with GC. p53 protein expression was also correlated with cardial location, nodal involvement and tumor stage. c-ErbB2 may recognize a group of highly aggressive well differentiated adenocarcinomas with worse prognosis. c-myc was also significantly enhanced in well differentiated tumors. EGFr showed no significant associations. Mantel-Cox was performed to compare the prognostic value of tumor stage, p53 protein expression and tumor angiogenesis. Tumor angiogenesis was the most important prognostic indicator to predict overall survival in our series. p53 expression was not independent and did not provide additional prognostic information to tumor stage. Our study suggests that angiogenesis as demonstrated by microvessel counts in CD34 stained sections is a significantly important Offprint requests to: Julian Sanz Ortega, MD, Departamento de Anatomia Patolbgica, Hospital Universitario "San Carlos". Martin Lagos s.n., Madrid 28040, Spain. Fax: 34-913303032, e-mail: jsanz@ hcsc.insalud.es prognostic factor for predicting survival in gastric cancer.
- PublicationOpen AccessEffects of ethanol on the ultrastructure of the hamster thyroid C-cell(Murcia : F. Hernández, 2000) chen, H.; Hayakawa, D.; Emura, S.; Tamada, A.; Ozawa, Y.; Taguchi, H.; Yano, R.; Shoumura, S.The morphology of the thyroid C-cells in golden hamsters after short- and long-term treatment with ethanol was studied. Immunohistochemistry was applied to examine the distribution of the C-cells in the thyroid gland. In the short-term experimental animals, the Golgi complexes and the granular endoplasmic reticulum were well developed and the number of the secretory granules was decreased as compared with those of the control animals. These findings suggest that the cellular activity of the thyroid C-cell is stimulated after short-term treatment with ethanol. The morphology of the thyroid C-cells of the long-term experimental animals was similar to that of the controls. It is conceivable that long-term treatment with ethanol does not affect the function of the C-cell.
- PublicationOpen AccessMelatonin, experimental basis for a possible application in breast cancer prevention and treatment(Murcia : F. Hernández, 2000) Cos, S.; Sánchez Barceló, E. J.The role of the pineal as an oncostatic gland has been studied in animal models of tumorigenesis, especially on those concerning the mammary gland. The general conclusion is that experimental manipulations activating pineal gland, or the administration of melatonin, reduce the incidence and growth rate of chemically-induced murine mammary tumors, while pinealectomy or situations which implicate a reduction of melatonin production usually stimulate mammary carcinogenesis. The direct actions of melatonin on mammary tumors have been suggested because of its ability to inhibit, at physiological doses (InM), the in vitro proliferation of MCF-7 human breast cancer cells. In this article we review the outstanding findings related to melatonin actions on mammary which, taken together, support a possible usefulnes of this indoleamine in the prevention and treatment of mammary gland malignancy.
- PublicationOpen AccessPathophysiology of primary hyperparathyroidism(Murcia : F. Hernández, 2000) Hellman, P.; Carling, T.; Rask, L.; Akerstrom, G.Parathyroid gland is the overall regulatory organ within the systemic calcium homeostasis. Through cell surface bound calcium-sensing receptors external calcium inversely regulates release of parathyroid hormone (PTH). This mechanism, which is voltage independent and most sensitive around physiologic calcium concentrations, is regulated through a 120 kDa calcium sensing receptor, CaR. Inherited inactivation of this receptor is the cause for familial hypocalciuric hypercalcemia (FHH). Parallel research identified the 550 kDa glycoprotein megalin, which also is expressed on the parathyroid cell surface, as another potential calcium sensing protein. Although this protein expresses numerous calcium binding sites on its external domain, its main function may be calcium sensitive binding and uptake of steroid hormones, such as 25-OH-vitamin Dg (bound to vitamin D binding protein) and retinol. In hyperparathyroidism (HPT), excessive PTH is secreted and the calcium sensitivity of the cells reduced, i.e. the set-point, defined as the external calcium concentration at which half-maximal inhibition of PTH release occurs, shifted to the right. Pathological cells have reduced expression of both CaR and megalin, and reduced amount of intracellular lipids, possibly including stored steroid hormones. A number of possible genetic disturbances have been identified, indicating multifactorial reasons for the disease. In postmenopausal women, however, the individual group with highest incidence of disease, a causal relation to reduced effect of vitamin D is possible. An incipient renal insufficiency with age, lack of sunshine in the Northern Hemisphere, and an association to the baT haplotype of the vitamin D receptor supports this theory. This review summarizes data on regulation of PTH release, dysregulation in HM; as well as proliferation of parathyroid cells.