Biomedical subjects

M Picardo

Publications and source records attributed to M Picardo.

129 records · Page 8Linked to original sources

PubMedDate not supplied

Cell-mediated antisperm immunity in selected forms of male infertility.

Leukocyte migration inhibition test (LMT) with semipurified spermatozoal antigen was carried out in two groups: normal males (fertile subjects before vasectomy; normal volunteers) and selected forms of male infertility. The percent positivity to the LMT in all the pathological groups considered, compared with controls positivity in only one out of 40 cases and only at the highest concentrations of Ag, stresses the important role played by cell-mediated antisperm immunity in male infertility. No characteristic seminal pattern was observed in the patients with positive LMT, probably on account of the particular selection of the patients studied. Finally, no significant correlation between humoral and cell-mediated antisperm immunity was observed, at least not in these selected series of patients.

Adult↗

PubMedDate not supplied

Partially reassembled high density lipoproteins. Effects on cholesterol flux, synthesis, and esterification in normal human skin fibroblasts.

The effects of a partially reassembled high density lipoprotein (PR-HDL) prepared by a detergent removal method on the cholesterol metabolism of fibroblasts has been tested under conditions of lipid depletion. The PR-HDL were composed of apolipoprotein A-I (1 mol) from human plasma HDL, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) 100 mol, and varying amounts of cholesterol. Below 15 mol%, the PR-HDL effected a net efflux of cholesterol from the fibroblasts; as a consequence, the activities of 3-hydroxy-3-methylglutaryl coenzyme A reductase and acyl coenzyme A acyltransferase, respectively, were increased and decreased. Above 15 mol% cholesterol in the PR-HDL, net influx of cholesterol was observed and 3-hydroxy-3-methyl-glutaryl coenzyme A reductase activity was decreased, while acyl coenzyme A acyltransferase activity was increased. The uptake of several phosphatidylcholines, apo A-I, and cholesterol were measured as a function of time. The rates of lipid transfer to the cells decreased with increasing hydrophobicity of the transferring lipid. By contrast, in parallel experiments a relatively small quantity of 125I apo A-I was associated with the cells. Our results suggest that a component of lipid transfer from PR-HDL to fibroblasts occurs via monomeric transfer through the aqueous phase that is independent of apo A-I binding.

Cells, Cultured↗

PubMedDate not supplied

Levels of enzymatic antioxidants activities in mononuclear cells and skin reactivity to sodium dodecyl sulphate.

Chemical irritants are able to produce several biological modifications of the skin, including the direct or indirect production of cytokines and reactive oxygen species leading to an inflammatory reaction. This report examines the existence of a possible correlation between the skin sensitivity to the irritant sodium dodecyl sulphate (SDS) and the activity of the enzymatic antioxidants. In twenty-three healthy subjects the evaluation of the epidermal and peripheral blood mononuclear cells (PBMCs) activities of Superoxide Dismutase (SOD) and Catalase (Cat) demonstrate a significant correlation (r= 0,85 and p< 0,005 for SOD, and r= 0,87 and p< 0,0001 for Cat). Based on this result, on a further group of normal subjects (n=13) we studied the link between the threshold dose of skin reactivity to SDS and the activities of the enzymatic antioxidants in PBMCs. The degree of skin modification induced by SDS, applied at different concentrations for 24 hrs, was determined by means of Trans Epidermal Water Loss (TEWL), Erythemal Index or by Visual Score (VS). The minimal dose of the irritant capable of inducing skin modifications, was significantly correlated with SOD (r=0,77) and Cat (r=0,81) activities in PBMCs, and the modification of TEWL or EI were inversely correlated with levels of antioxidants in PBMCs (r=-0,62 for SOD and r=-0,66 for Cat). Our results indicate that the skin reactivity to irritants can be modulated by the levels of antioxidants, and suggest a possible therapeutical approach in preventing irritant contact dermatitis.

Adult↗