Thermal Annealing of Gold Thin Films on the Structure and Surface Morphology Using RF Magnetron Sputtering

Gold(Au)thin films were deposited on SiO2 substrate under argon(Ar)gas environment using RF(radio frequency)magnetron sputtering at room temperature for various...     

Autocrine inhibition of the epidermal growth factor receptor by intracellular expression of a single-chain antibody

A gene encoding a single-chain antibody which specifically binds the human epidermal growth factor (EGF) receptor has been constructed and expressed intracellularly. The single-chain antibody is derived from monoclonal antibody 225 which competes with EGF for binding to the extracellular domain of the receptor. The single-chain antibody was provided with a signal peptide to direct it to the secretory pathway and was expressed in EGF receptor transformed NIH/3T3 fibroblasts. EGF induced activation of its receptor was reduced in these cells. In addition, EGF-induced anchorage-independent growth of the cells was inhibited. The data suggest that the single-chain antibody functions in an autocrine fashion to inhibit the activity of the EGF receptor.     

Proteolytic activity of three probiotic strains in semi-hard cheese as single and mixed cultures: Lactobacillus acidophilus,Lactobacillus paracasei and Bifidobacterium lactis

The influence of three probiotic strains (Lactobacillus acidophilus, Lactobacillus paracasei and Bifidobacterium lactis) in semi-hard cheese proteolysis patterns was assessed. Probiotics were inoculated both as single cultures and as a three-strain mix, and added to milk either after a pre-incubation step or directly to the vat. B. lactis did not show any effect on proteolysis of cheeses, while L. paracasei showed limited impact at the end of the ripening. In contrast, L. acidophilus significantly influenced secondary proteolysis from the beginning of ripening, causing an increase in the levels of small nitrogen-containing compounds and free amino acids and changes in the peptide profiles. The effect of Lactobacillus acidophilus on peptidolysis was more noticeable when it was added to cheese–milk after pre-incubation in an enriched milk fat substrate. Similar results obtained with the three-strain mixed culture, suggesting that L. acidophilus played a major role in secondary proteolysis of probiotic cheeses in this trial.     

TAG-1 can mediate homophilic binding, but neurite outgrowth on TAG-1 requires an L1-like molecule and beta 1 integrins

Subsets of axons in the embryonic nervous system transiently express the glycoprotein TAG-1, a member of the subfamily of immunoglobulin (Ig)-like proteins that contain both C2 class Ig and fibronectin type III domains. TAG-1 is attached to the cell surface by a glycosylphosphatidylinositol linkage and is secreted by neurons. In vitro studies have shown that substrate-bound TAG-1 promotes neurite outgrowth. We have examined the nature of axonal receptors that mediate the neurite-outgrowth promoting properties of TAG-1. Although TAG-1 can mediate homophilic binding, neurite outgrowth on a substrate of TAG-1 does not depend on the presence of TAG-1 on the axonal surface. Instead, neurite outgrowth on TAG-1 is inhibited by polyclonal antibodies directed against L1 and, independently, by polyclonal and monoclonal antibodies against beta 1-containing integrins. These results provide evidence that TAG-1 can interact with cell surfaces in both a homophilic and heterophilic manner and suggest that neurite extension on TAG-1 requires the function of both integrins and an L1-like molecule.     

The tumour-suppressor gene patched encodes a candidate receptor for Sonic hedgehog

The protein Sonic hedgehog (Shh) controls patterning and growth during vertebrate development. Here we demonstrate that it binds Patched (vPtc), which has been identified as a tumour-suppressor protein in basal cell carcinoma, with high affinity. We show that Ptc can form a physical complex with a newly cloned vertebrate homologue of the Drosophila protein Smoothened (vSmo), and that vSmo is coexpressed with vPtc in many tissues but does not bind Shh directly. These findings, combined with available genetic evidence from Drosophila, support the hypothesis that Ptc is a receptor for Shh, and that vSmo could be a signalling component that is linked to Ptc.