Protonated poly(propylene imine) dendrimers (Astramol) of five generations: DAB-dendr-(NH2)x (where x=4, 8, 16, 32 or 64) are sorbed by slightly cross-linked polyanionic hydrogels: poly(sodium acrylate) and poly(sodium 2-acrylamido-2-methylpropane sulfonate). As a result highly swollen original hydrogel transforms into compact cross-linked polyelectrolyte-dendrimer complexes. Sorption of dendrimers by the hydrogels is a chemically drawn frontal diffusion process. Driving force comes from the gain in the free energy of interpolyelectrolyte coupling reaction between the charged dendrimer molecules and the oppositely charged hydrogel network, accompanied with entropically favourable release of low molecular salt into environment. The amount of a simple salt released is equivalent to a number of intermolecular salt bonds, formed between protonated dendrimers and hydrogel networks. Apparently the mechanism of dendrimer uptake involves a "relay-race" transfer of dendrimer polycations from one fragment of polyelectrolyte network to the other via interpolyelectrolyte exchange reaction. As a result "core-shell" constructs consisting of outer weakly swollen complex shell and highly swollen hydrogel core are formed at intermediate stages of the process. The rate of sorption is determined by the rate of the interpolyelectrolyte exchange reaction that is the rate of the formation of free fragments of polyelectrolyte network (vacancies) on the inner complex-hydrogel boundary. The amount of vacancies depends on the area of this boundary. Consequently kinetics of dendrimer uptake could not be fitted in terms of Fickian diffusion (except DAB-dendr-(NH2)4), but expressed in terms of the kinetic equation derived for a frontal heterogeneous reaction. Sorbed dendrimers of all studied generations at pH values ensuring complete protonation of primary and tertiary amine groups are closely packed in hydrogel networks, so that all dendrimer cationic units form ion pairs with anionic units of hydrogels. In other words polyanionic network fragments are able to penetrate into the interior of fully protonated DAB-dendr-(NH2)x species as it was earlier shown for flexible linear polyanions. In such case the ultimate amount of sorbed dendrimer molecules is always determined by the condition n(a)/N- = 1, where n(a) is the total number of dendrimer amine groups, N- is the number of the anionic hydrogel units. The latter is also true for the complex shell composition in the heterogeneous reacting samples formed at intermediate stages of dendrimers uptake. Variation of pH and sorption extent is an effective tool to control dendrimer distribution, self-organization and the final structure of dendrimer-hydrogel constructs.

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CD3f has emerged as a clinically important immunological marker in head and neck squamous cell carcinoma (HNSCC) with reduced level of expression reported in both tumor infiltrating lymphocytes and peripheral blood lymphocytes. In this prospective study (power 5 0.99, a 5 0.05), CD3f expression was compared in 47 HNSCC patients and 53 controls using standardized flow cytometric method. There was no statistical difference in the percentages of the CD3 e1 T-cell subset present in the peripheral blood mononuclear cells of the HNSCC patients and the healthy controls; however, T cells from the HNSCC patients produced a significantly weaker IFN-c response in comparison to the healthy controls, when they were stimulated by the recall viral CEF peptide antigen. All patients were followed up for at least 3 years with a median follow-up of 45 months. Levels of CD3f-chain expression were measured at 117 follow-up visits at six-month intervals. Receiver operating characteristic curve identified the optimal cut off as a 12% increase in post treatment CD3f-chain expression from the baseline levels to confirm absence of HNSCC with the area under curve of 0.81 (95% CI 5 0.68-0.94) for predicting absence of HNSCC. The specificity, sensitivity and positive predictive value were 81.25% 79.21% and 97.56%, respectively. Three-year disease specific survival (DSS) was significantly lower (p 5 0.007) at 63.2% for patients who showed <12% increase in CD3f-chain level as compared to 96.2% for patients who had 12% increase. Our results indicate that the change in CD3f-chain expression from the baseline is an independent predictor of residual and recurrent HNSCC.

Protein kinase C catalyzes phosphorylation of the rat skeletal muscle AMP-deaminase in the presence of calcium ions and phosphatidylserine. At the same time, the catalytic subunit of CAMP-dependent protein kinase fails to phosphorylate AMP-deaminase. CaZ', phosphatidylserine-dependent phosphorylation decreases three-fold (from 0.6 to 0.2 mM) the K,,, value and does not affect V,.. Protein kinase C-induced phosphorylation of AMP-deaminase, besides ADP-ribosylation, is suggested to be involved in regulating the AMP-deaminasc activity in vivo.