Histology and histopathology Vol.16, nº 3 (2001)
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- PublicationOpen AccessCaspase inhibition, a potential therapeutic strategy in neurological diseases(Murcia : F. Hernández, 2001) Rideout, H.J.; Stefanis, L.Caspases are intracellular proteases that participate in apoptotic pathways in mammalian cells, including neurons. Here we review evidence that caspase inhibition, through pharmacological or molecular means, rnay inhibit neuronal cell death in a number of in vitro and in vivo models of neurological disease. It has recently become clear that, at least in most cell culture models, caspase inhibition offers only transient protection, and that a caspase-independent death eventually occurs. This rnay be due to irreversible caspase-independent alterations at the leve1 of the mitochondria. Despite concerns that targeting caspases alone rnay prove insufficient to truly reverse the effects of various death stimuli, in vivo studies indicate that caspase inhibition promotes survival and functional outcome in a variety of neurological disease models. In addition, studies of human post-mortem material suggest that caspases are activated in certain human neurological diseases. Caspase inhibition rnay therefore provide a novel strategy for the treatment of such disorders. Caspas'es, through the generation of toxic fragments of critica1 protein substrates, rnay also be involved in earlier steps of neuronal dysfunction, such as protein aggregation in Huntington's and Alzheimer's disease, and therefore caspase inhibition rnay be of additional value in the treatment of these particular disorders.
- PublicationOpen AccessNeurotransmitters, neuromodulators, and neurotrophin receptors in the gut of pantex, a hybrid sparid fish (Pagrus major x Dentex dentex). Localizations in the enteric nervous and endocrine systems(Murcia : F. Hernández, 2001) Radaelli, G.; Domeneghini, C.; Arrighi, S.; Castaldo, L.; Lucini, C.The gut of Pantex, a sparid hybrid fish (Pagrus major x Dentex dentex) with a great potential importance for the Italian aquaculture, was histochemically and immunohistochemically investigated in order to evidence components of the intramural nervous and diffuse endocrine systems. The general structural aspects of the intramural nervous system were shown by the Nissl-thionin staining. As in most other fish, it was only organized in the myenteric plexus. Acetylcholinesterase (AChE) activity was observed in both nerve cell bodies and terminals al1 along the gut. The NADPH-diaphorase reactivity too, possibly linked to the synthesis and release of nitric oxide, was present in nerve cell bodies and nerve terminals of the oesophagus, stomach and intestine. In addition, the intramural nervous system was shown to contain Trk (tyrosinekinase) receptors for neurotrophin, as evidenced by Trk A-, Trk B- and Trk C-like immunoreactivities, thus suggesting an involvement of neurotrophin in the function of this system. Trk B- and Trk C-like immunoreactivities were detected in epithelial endocrine cells, too. The additional presence of serotonin- and metenkephalin- like immunoreactivities in numerous endocrine cells in the epithelial layers of the stomach and intestine was showed.
- PublicationOpen AccessAcute toxicity of anionic surfactants sodium dodecyl sulphate (SDS) and linear alkylbenzene sulphonate (LAS) on the fertilizing(Murcia : F. Hernández, 2001) Rosety, M.A.; Ordóñez Muñoz, F.J.; Rosety-Rodriguez, M.; Rosety, J.M.; Rosety, I.; Carrasco, C.; Ribelles, A.In the present work we have evaluated and compared the acute toxicity of two anionic surfactants, Sodium Dodecyl Sulphate (SDS) and Linear Alkylbenzene Sulphonate (LAS) on the fertilizing capability of gilthead Sparus aurata L. sperm. The criterion used to judge exposure effectiveness was fertilization success. Spawned eggs and sperms were collected from adult giltheads. Sperms were dosed separately with different concentrations of SDS and LAS for 60 minutes. After this period, sperms and eggs were combined for 20 minutes during which fertilization took place. Finally, the number of fertilized eggs were counted and recorded to estimate the percentage of fertilization. Exposure to SDS and LAS concentrations of 0.3, 0.6, 1.5, 3 and 6 mg/L for 60 minutes caused a significant inhibitory effect on fertilization success in gilthead Sparus aurata L.. In addition, the EC50 value for gilthead fertilization after sperm exposure was found to be 2.8 mg/L and in the case of LAS it was of 2.6 The comparison of the results from SDS and LAS shows that the latter has a stronger negative effect on sperm viability than SDS.
- PublicationOpen AccessUltrastructural observations on the microvasculature in advanced gastric carcinomas(Murcia : F. Hernández, 2001) Caruso, R.A.; Speciale, G.; Inferrera, A.; Rigolis, L.; Inferrera, C.The ultrastructural features associated with vascular permeability in 9 cases of advanced gastric carcinomas were studied, and compared with that of control non-neoplastic mucosa. Tumour rnicrovasculature showed features in common with those of control mucosa, including complete basa1 lamina, welldeveloped interendothelial junctions, fenestrations and caveolae. Some tumour blood vessels showed endothelial cell swelling accompained by luminal narrowing and perivascular fibrosis. In 2 out of 9 cases, there were endothelial attenuation with numerous fenestrations and vesiculo-vacuolar organelles. The vesiculo-vacuolar organelle is a recently described cytoplasmic structure found in the endothelial cells lining turnour microvessels and normal venules and which provides an important pathway for extravasation of circulating macromolecules. Our ultrastructural data suggest that advanced gastric carcinomas share with experimental tumour models in vivo only some morphologic features associated with hyperpermeability including fenestration, endothelial attenuation and vesiculo-vacuolar organelles. The implications of perivascular fibrosis on the delivery of immune cells to gastric carcinomas are discussed.
- PublicationOpen AccessOpiomelanins synthesis and properties(Murcia : F. Hernández, 2001) Rosei, M.A.Opiomelanins represent a new class of synthetic pigments produced by the tyrosinase-catalyzed oxidation of opioid peptides and other tyrosine aminoterminal peptides. In contrast with dopamelanin, these polymers are fully soluble in hydrophilic media, due to the presence of the peptide moiety. Opiomelanins show paramagnetism as demonstrated by the EPR spectrum identical to that of dopamelanin. The presence of the aminoacidic chain linked to the melaninic moiety, influences the electron transfer properties of opiomelanins i.e. the ability to oxidize NADH. Like dopamelanin Tyr-Gly-melanin exhibits this behaviour whereas leuenkmelanin does not show any oxidizing potential. Opiomelanins UV-Vis spectrum is characterized by an absorption band at 330 nm which disappears upon acid hydrolysis, H202 treatment and under simulated solar illumination. Opiomelanins exhibit a fluorescence emission peaked at 440 and 520 nm if excited at 330 nm. These fluorescence bands are due to the oligomeric units and high molecular weight units, respectively. When opioid peptides are allowed to react with tyrosinase in the presence of an excess of cysteine, cysteinyldopaenkephalins are synthesized. These peptides are furtherly oxidized giving rise to pheoopiomelanins. Reactive oxygen species also are able to oxidize non enzymatically both enkephalins and cysteinyldopaenkephalins, producing the corresponding melanin pigments .