Functional Effects of Adiponectin on Endothelial Progenitor Cells

Adiponectin is an adipokine whose plasma levels are inversely correlated to metabolic syndrome components. Adiponectin protects against atherosclerosis and decreases risks in myocardial infarction. Endothelial progenitor cells (EPCs) are a heterogeneous population of circulating cells involved in vascular repair and neovascularization. EPCs number is reduced in patients with cardiovascular disease. We hypothesize that the positive effects of adiponectin against atherosclerosis are explained in part by its interactions with EPCs. Cells were obtained from healthy volunteers' blood by mononuclear cell isolation and plating on collagen‐coated dishes. Three sub‐populations of EPCs were identified and characterized using flow cytometry. EPCs' expression of adiponectin receptors, AdipoR1, and AdipoR2 was evaluated by quantitative PCR. The effects of recombinant adiponectin on EPCs' susceptibility to apoptosis were assessed. Finally, expression of neutrophil elastase by EPCs and activity of this enzyme on adiponectin processing were assessed. Quantitative PCR analysis of EPCs mRNAs showed that AdipoR1 mRNA is expressed at higher levels than AdipoR2. Expression of AdipoR1 protein was confirmed by western blot. Adiponectin significantly increased survival of two sub‐populations of EPCs in conditions of serum deprivation. Such effect could not be demonstrated in the third EPCs sub‐population. We also demonstrated that EPCs, particularly one sub‐population, express neutrophil elastase. Neutrophil elastase activity was confirmed in EPCs' conditioned media. Adiponectin protects some EPCs sub‐populations against apoptosis and therefore could modulate EPCs ability to induce repair of vascular damage. Neutrophil elastase activity of EPCs could locally modulate adiponectin activity by its involvement in the generation of the globular form of adiponectin.     

Physiological and pathogenic characteristics of Nocardia brasiliensis isolated from human mycetomas

A previous analysis of the physiological properties of Nocardia brasiliensis strains isolated from soil of Tucumán proves that non-pathogenic strains have a different behaviour pattern from the pathogenic strains.In the present paper, 16 Nocardia brasiliensis strains isolated from human mycetomas were studied in the same way. The object is to determine if any of the Nocardia brasiliensis present in soil can produce human mycetomas.The macro and micromorphological, biochemical (17 tests), physiological (4 tests) and pathological characteristics were determined for each of the strains. Experimental pathogenicity was determined using albino Swiss mice by inoculation into the footpads.The strains of Nocardia brasiliensis that cause human mycetomas have the same physiological pattern and experimental pathogenicity as the virulent strains present in soil.     

Ethylene and in vitro rooting of hazelnut (Corylus avellana) cotyledons

Ethylene may be one of the many factors that play a role in rooting. However, in some studies ethylene promoted rooting, while in others it was inhibitory or had no effect. Using cotyledons of hazelnut ( Corylus avellana L. cv. Casina) observations were made of the effect of ethylene precursors on adventitious root formation. l-methionine (Met) or 1-aminocyclopropane-1-carboxylic acid (ACC) added to a standard indole-3-butyric acid (IBA)-kinetin-containing medium did not enhance rooting, while 2-chloroethylphosphonic acid (CEPA) did. The ethylene inhibitor, aminoethoxyvinylglycine (AVG), inhibited root formation, but its effect was reversed by ACC when cotyledonary segments were transferred to rhizogenic medium plus ACC at day 10. Ethylene production by cotyledons cultured on rhizogenic medium or rhizogenic medium plus CEPA was high at the beginning of rooting. Thus, the wound-induced ethylene is a key stimulatory factor in the formation of root primordia. The data support the hypothesis that ethylene plays a positive role in root formation.     

Detection of P-glycoprotein on endothelial and endocrine cells of the human pancreatic islets by C 494 monoclonal antibody

Summary P-glycoprotein, an integral membrane protein acting as an energy-dependent efflux pump, has been detected immunocytochemically in the human pancreatic islets using C 494 monoclonal antibody. Intense P-glycoprotein immunoreactivity was found in both endothelial cells of islet blood capillaries and in endocrine cells. Strong expression of P-glycoprotein has been found in the capillary blood vessels at blood-tissue barrier sites and in numerous kinds of cells with secretory/excretory function. Therefore the present findings suggest that P-glycoprotein may play a role in controlling the composition of the extracellular fluids and the intracellular milieu of endocrine islet cells and possibly in regulating their secretory activity.     

Effect of Drying Medium on Residual Moisture Content and Viability of Freeze-Dried Lactic Acid Bacteria

The effect of various substances on the relationship between residual moisture content and the viability of freeze-dried lactic acid bacteria has been studied. Compounds such as polymers, which display considerable ability in displacing water, showed no protective action during freeze-drying. Adonitol, on the other hand, produced the smallest change in water content at various times during drying and allowed the highest rate of survival.