No abstract

Daily consumption of calcium-fortified ice cream by premenopausal women may significantly reduce levels of the bone resorption marker serum CTX, without stimulating weight gain. The ice cream could be incorporated into the diet to replace low-calcium snacks and thus help individuals with habitually low calcium intakes to meet recommended intakes. The 244 mg calcium preparation would provide more than a quarter of the UK daily recommended nutrient intake for premenopausal women.

The nasal decongestants oxymetazoline and xylometazoline are frequently used in the topical treatment of rhinitis and sinusitis. As nitric oxide (NO) is thought to play a role in inflammation of the upper respiratory tract, the aim of this study was to examine the in vitro effects of these compounds on the activity and the expression of NO producing enzymes, including the inducible form of NO synthase (iNOS) and the constitutive isoform of NO synthase (cNOS).Experiments concerning the effects of both compounds on enzymatic activity and enzyme induction of iNOS were performed in a lipopolysaccharide (LPS) induced rat alveolar macrophage cell line (NR8383) using the Griess assay and the 3 H-citrulline assay respectively. The effects on cNOS were examined in fresh rat synaptosomes using the 3 H-citrulline assay. The direct scavenging properties of both compounds were investigated using a amperometric NO sensor.Oxymetazoline and xylometazoline were shown to have a dose dependent inhibitory effect on total iNOS activity indicated by nitrite/nitrate formation in the Griess assay. This effect was found to be due to an inhibition of induction of the enzyme rather than inhibition of the enzyme activity, as was investigated in two separate experiments using the 3 H-citrulline assay. Inhibition of cNOS was moderate and in the same order of magnitude as the inhibition of enzymatic iNOS activity. Direct scavenging of NO could not be detected.As constitutive nitric oxide synthase activity is thought to serve beneficial physiological functions, and exaggerated inducible nitric oxide synthase activity may cause exacerbation of the inflammatory process, pharmacological treatment influencing the nitric oxide generating system should focus on inhibition of inducible nitric oxide synthase alone. The specific characteristics of these decongestants in vitro suggests suitability for this application and may indicate an additional beneficial effect in the treatment of upper respiratory tract inflammation. Eur Respir J 2000; 16: 437±444.

Iron is transported across intestinal brush border cells into the circulation in at least two distinct steps. Iron can enter the enterocyte via the apical surface through several paths. However, iron egress from the basolateral side of enterocytes converges on a single export pathway requiring the iron transporter, ferroportin1, and hephaestin, a ferroxidase. Copper deficiency leads to reduced hephaestin protein expression and activity in mouse enterocytes and intestinal cell lines. We tested the effect of copper deficiency on differentiated Caco2 cells grown in transwells and found decreased hephaestin protein expression and activity as well as reduced ferroportin1 protein levels. Furthermore, the decrease in hephaestin levels correlates with a decrease of (55)Fe release from the basolateral side of Caco2 cells. Presence of ceruloplasmin, apo-transferrin or holo-transferrin did not significantly alter the results observed. Repletion of copper in Caco2 cells leads to reconstitution of hephaestin protein expression, activity, and transepithelial iron transport.