Improved methodology for the detection and quantification of the acrosome reaction in mouse spermatozoa.

This study evaluates the use of two fluorescein-labelled (FITC) plant lectins, Pisum sativum (edible pea) agglutinin (PSA) and Arachis hypogaea (peanut) agglutinin (PNA), in order to determine the most accurate and reliable method to experimentally detect and assess the acrosome reaction in mouse spermatozoa. PNA-FITC labelling was restricted to the acrosome and was not influenced by the fixation procedure; either absolute methanol or paraformaldehyde. In contrast, PSA-FITC not only labelled the acrosome, but also the whole head and the flagellum.

Rapid changes in liver lipid composition and pancreatic islet K+ handling and secretory behaviour provoked by the intravenous administration of a medium-chain triglyceride: fish oil emulsion to long-chain polyunsaturated omega3 fatty acid-depleted rats.

Second generation rats depleted in long-chain polyunsaturated omega3 fatty acids are currently used as an animal model for the insufficient dietary supply of such fatty acids often prevailing in Western populations. The present study deals mainly with the effects of a novel medium-chain triglyceride: fish oil emulsion (MCT:FO), as compared to a control medium-chain triglyceride:olive oil emulsion (MCT: OO), administered as an intravenous bolus to the omega3-depleted rats 60-120 min before sacrifice upon selected biochemical and biophysical variables. The major findings consisted of a severe decrease of the omega3 fatty acid content of liver lipids in non-injected omega3-depleted rats and its partial correction after injection of the MCT:FO emulsion.

Glucocorticoid-induced differential expression of the sialylated and nonsialylated Lewis(a) epitopes and respective binding sites in human nasal polyps maintained under ex vivo tissue culture conditions.

We characterized the anti-inflammatory effects of budesonide on the expression of adhesion molecules involving Lewis(a) (Le(a)) epitope, its sialylated derivative (sLe(a)), and their respective binding sites in human nasal polyposis. By computer-assisted microscopy, we quantitatively characterized the level of histochemical expression of L- and P-selectins, sialylated and nonsialylated Le(a) epitopes, and their respective binding sites in both surface epithelium and glandular epithelium of human nasal polyps obtained from surgical resection, maintained under ex vivo tissue culture conditions for 24 hours, and treated or not with budesonide. Intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) were chosen as methodological controls, because data already published in the literature clearly indicated budesonide-mediated effects on ICAM-1 and VCAM-1 levels of expression.

Galectins and cancer.

The galectins are a family of proteins that are distributed widely in all living organisms. All of them share galactose-specificity. At present, 14 members of the family are characterized in mammals.

Galectin-1 modulates human glioblastoma cell migration into the brain through modifications to the actin cytoskeleton and levels of expression of small GTPases.

We show that high-grade astrocytic tumors with high levels of galectin-1 expression are associated with dismal prognoses. The immunohistochemical analysis of galectin-1 expression of human U87 and U373 glioblastoma xenografts from the brains of nude mice revealed a higher level of galectin-1 expression in invasive areas rather than non-invasive areas of the xenografts. Nude mice intracranially grafted with U87 or U373 cells constitutively expressing low levels of galectin-1 (by stable transfection of an expression vector containing the antisense mRNA of galectin-1) had longer survival periods than those grafted with U87 or U373 cells expressing normal levels of galectin-1.