Radiative rates for E1, E2, M1 and M2 transitions in Fe X

Energies of the 54 levels belonging to the (1s(2)2s(2)2p(6)) 3s(2)3p(5), 3s3p(6), 3s(2)3p(4)3d and 3s3p(5)3d configurations of Fe X have been calculated using the GRASP code of Dyall et al. (1989). Additionally, radiative rates, oscillator strengths, and line strengths are calculated for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among these levels. Comparisons are made with results available in the literature, and the accuracy of the data is assessed. Our energy levels are estimated to be accurate to better than 3%, whereas results for other parameters are probably accurate to better than 20%. Additionally, the agreement between measured and calculated lifetimes is better than 10%.

The response of macrophages to particles of resorbable polymers and their degradation products

Alpha polyesters such as poly(L-lactide) and poly(glycolide) are biodegradable materials used in fracture fixation and they need to be assessed for problems associated with their degradation products. This study has compared cell responses to low molecular weight poly(L-lactide) particles, lactate monomer, poly(glycolide) particles and glycolic acid at cytotoxic and sub-cytotoxic concentrations. Murine macrophages were cultured in vitro and the release of lactate dehydrogenase (LDH), prostaglandin E-2 (PGE(2)) and interleukin-1 alpha IL-1alpha was measured following the addition of particles or monomer. Experiments revealed that both the poly(L-lactide) and poly(glycolide) particles gave rise to dose dependent increases in LDH release and an increase in IL-1alpha and PGE(2) release. Comparisons of the poly(L-lactide) particles to the poly(glycolide) particles did not reveal any differences in their stimulation of LDH, IL-1alpha and PGE(2) release. The lactate and glycolate monomers did not increase PGE(2) or IL-1alpha release above control levels. There was no difference in biocompatibility between the poly(L-lactide) and poly(glycolide) degradation products both in particulate and monomeric form. (C) 2003 Kluwer Academic Publishers.

Chemotaxis of macrophages is abolished in the Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome (WAS) is a rare disease characterized by microthrombocytopenia, eczema and immune deficiency. In this study a direct-viewing chemotaxis chamber was used to analyse chemotactic responses of WAS neutrophils and macrophages in stable linear concentration gradients. In five patients with classic WAS, chemotaxis of macrophages but not of neutrophils was found to be abolished, whereas the speed of random motility of both cell types was found to be indistinguishable from control cells. This supports the existence of an essential functional link, previously suggested by biochemical studies, between Cdc42, WAS protein (WASp) and the actin cytoskeleton in primary human macrophages. Moreover, these data suggest that Cdc42-WASp-mediated filopodial extension is a requirement for chemotaxis but not for chemokinesis in these cells. Abnormal directional cell motility of macrophages and related antigen-presenting cells may play a significant part in the immune deficiency and eczema of WAS.