Histology and histopathology Vol.23, nº1 (2008)

Ir a Estadísticas

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http://hdl.handle.net/10201/177712

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Open Access
Effects of sediment sorbed linear alkylbenzene sulphonate on juveniles of the Senegal sole, Solea senegalensis, Toxicity and histological indicators
(Murcia : F. Hernández, 2008) Hampel, M.; Ortiz-Delgado, J.B.; Sarasquete, C.; Blasco, J.
Many synthetic organic substances, including surfactants, tend to be sorbed on suspended solids and to accumulate finally on bottom sediments, where benthic communities may be exposed to them. Concentrations of Linear Alkylbenzene Sulphonates (LAS) have been detected in estuarine and coastal sediments, presenting wide concentration ranges depending on the presence of treatment facilities, hydrodynamic conditions, organic matter content, etc. Senegal sole, Solea senegalensis, larvae (40 days posthatching; dph) were exposed to increasing concentrations of LAS spiked sediments, comprised between 0.37 and 880.78 mg LAS·kg-1 during 30 days. The obtained results showed that survival of exposed larvae was not significantly affected at environmentally relevant concentrations, the LC50 value being obtained after 30 days 876.46 mg·kg-1. However, the histological and histopathological analyses carried out in target organs revealed, that first alterations from the normal pattern were observed at concentrations of 222.66 mg·kg-1, presenting effects such as blood extravasation and hyperplasy of the lamellar epithelium in gills, increase of inter-myotomal spaces of the skeletal musculature and edematous separation of the skin from epidermis. At the highest exposure concentrations (755.27 and 880.78 mg LAS·kg-1), shrinkage of hepatocytes, nuclear pycnosis and blood stagnation are observed in the liver, degeneration of pancreatic cells, reduction of hemocytopoietic tissue in the kidney and vacuolisation of intestinal enterocytes was observed at histological level, as well as severe separation of the epidermis from the underlying tissues. Simultaneously, a significant increase of the wet weight with exposure concentration was observed in the test organisms.
Open Access
AB deposition and related pathology in an APP x PS1 transgenic mouse model of Alzheimer s disease
(Murcia : F. Hernández, 2008) Howlett, D.R.; Bowler, K.; Soden, P.E.; Riddell, D.; Davis, J.B.; Richardson, J.C.; Burbidge, S.A.; Gonzalez, M.I.; Irving, E.A.; Lawman, A.; Miglio, G.; Dawson, E.L.; Howlett, E.R.; Hussain, I.
Summary. A transgenic mouse bearing mutant transgenes linked to familial forms of Alzheimer’s disease (AD) for the amyloid precursor protein and presenilin-1 (TASTPM) showed Aß plaque deposition and age-related histological changes in associated brain pathology. The Aß present was of multiple forms, including species with a C-terminus at position 40 or 42, as well as an N-terminus at position 1 or truncated in a pyro-3-glutamate form. Endogenous rodent Aß was also present in the deposits. Laser capture microdissection extracts showed that multimeric forms of Aß were present in both plaque and tissue surrounding plaques. Associated with the Aß deposits was evidence of an inflammatory response characterised by the presence of astrocytes. Also present in close association with the deposits was phosphorylated tau and cathepsin D immunolabelling. The incidence of astrocytes and of phosphorylated tau and cathepsin D load showed that both of these potential disease markers increased in parallel to the age of the mice and with Aß deposition. Immunohistochemical labelling of neurons in the cortex and hippocampus of TASTPM mice suggested that the areas of Aß deposition were associated with the loss of neurons. TASTPM mice, therefore, exhibit a number of the pathological characteristics of disease progression in AD and may provide a means for assessment of novel therapeutic agents directed towards modifying or halting disease progression.
Open Access
Ghrelin localization in the medulla of rat and human adrenal gland and in pheochromocytomas
(Murcia : F. Hernández, 2008) Raghay, K.; Garcia-Caballero, Tomas; Bravo, S.; Alvárez, C.V.; González, R.; Diéguez, C.; Beiras, Andres; Fraga, M.; Gallego, R.
Objective: Ghrelin is predominantly produced by neuroendocrine cells of stomach and has been expressed in several normal and tumour endocrine tissues. It has been reported that the localization of ghrelin is exclusively in the cortex of human and rat adrenal gland and in adrenocortical tumours. This prompted us to analyze the expression of this peptide in medulla of human and rat adrenal glands and in human pheochromocytomas. Design and methods: Analysis of ghrelin mRNA expression in rat adrenal gland was conducted by means of semi-quantitative RT-PCR. Ghrelin localization was studied in medulla of human and rat adrenal gland by immunohistochemistry. In addition, we have carried out a double immunofluorescence with chromogranin A to determine the specific cell type expressing ghrelin immunoreactivity. Ghrelin expression was also analyzed in five cases of pheochromocytoma by immunohistochemistry. Finally, Western blotting analysis was performed with goat ghrelin antibody in the cortex and in the medulla of rat adrenal gland. Results: RT-PCR demonstrated expression of ghrelin mRNA in rat adrenal gland. We also detected ghrelin expression in virtually all rat pheochromocytes by immunohistochemistry and double immunofluorescence. Furthermore, we showed ghrelin immunoreactivity in the medulla of human adrenal gland and in pheochromocytomas. By Western blotting, we found the expression of ghrelin precursor, proghrelin and mature ghrelin in the medulla of rat adrenals. However, the cortex of rat adrenal gland only expressed ghrelin precursor. Conclusions: Our study is the first to demonstrate a medullar expression of ghrelin in human and rat adrenal gland; we also showed ghrelin expression in pheochromocytomas.
Open Access
Molecular characterization of small peripheral lung tumors based on the analysis of fine needle aspirates
(Murcia : F. Hernández, 2008) Zudaire, I.; Lozano, M.D.; Vazquez, M.F.; Pajares, M.J.; Agorreta, J.; Pio, R.; Zulueta, J.J.; Yankelevitz, D.F.; Henschke, C.I.; Montuenga, L.M.
The computed tomography (CT)-based early lung cancer diagnostic technologies allow the detection of very small stage I lung tumors. As part of these screening protocols any suspicious nodule has to be diagnosed morphologically, which requires CT-guided Fine Needle Aspiration, open biopsy or surgery. Fine Needle Aspiration (FNA) cytology is a well-recognised method for a rapid and accurate diagnosis of small lung tumors. Molecular analysis of the FNA specimens could complement cytology diagnosis by the characterization of the biological traits at the preoperative stage. In this study, we aimed to characterize the biological profile of 33 paraffin-embedded transthoracic FNA samples obtained from three groups of lung cancer patients: two groups of small early-detected lung adenocarcinomas (radiologically subsolid and solid nodules) and a third group of small metastatic adenocarcinomas. Genetic analysis was performed by fluorescence in situ hybridization using the four-color LAVysion probe. p53 and Ki-67 protein expression was also evaluated by immunocytochemistry. The samples showed gains for all targets analyzed; two cases had EGFR gene amplification and two cases had MYC amplification. There were no significant differences in the percentage of genetically malignant cells and the expression of Ki- 67 among the three groups. However, p53 accumulation was significantly higher in the metastatic group compared to the subsolid early-detected group (P = 0.001). In conclusion, molecular analysis of FNA specimens may provide useful information at preoperative stages. In our series, a good prognostic profile in subsolid early detected adenocarcinomas is suggested.
Open Access
Adrenomedullin expression in pituitary adenomas and nontumoral adenohypophyses
(Murcia : F. Hernández, 2008) Lombardero, M.; Kovacs, K.; Horvath, E.; Scheithauer, B.W.; Rotondo, F.; Salehi. F; Lloyd, R.V.
Summary. Adrenomedullin (ADM) is a novel peptide originally identified in extracts of human pheochromocytoma. It is produced by several tissues, including the pituitary gland. The presence of ADM has been immunohistochemically demonstrated in pathologic pituitary glands, but no systematic study of ADM expression in human pituitary adenomas has been reported. Thus, we investigated ADM immunoexpression in 88 various hormone-secreting and clinically nonfunctioning pituitary adenoma types as well as 30 nontumoral adenohypophyses. Furthermore, ADM immunoreactivity was assessed on a 0 to +3 scale in all samples. We found strong immunoreativity for ADM in normal gonadotrophs also expressing FSH and LH whereas in the other adenohypophysial cell types expression of ADM was mild. Results showed that normal adenohypophyses were strongly immunopositive for ADM (2.18±0.11). Our findings demonstrate that ADM expression in the anterior pituitary is diminished in tumors as compared to the normal gland. The physiologic function of ADM is unknown, but it could act as a paracrine or autocrine factor in the adenohypophysis.

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