Microtubule polyglutamylation is an essential regulator of cytoskeletal integrity in Trypanosoma brucei

Tubulin polyglutamylation, catalysed by members of the tubulin tyrosine ligase-like (TTLL) protein family, is an evolutionarily highly conserved mechanism involved in the regulation of microtubule dynamics and function in eukaryotes. In the protozoan parasite Trypanosoma brucei, the microtubule cytoskeleton is essential for cell motility and maintaining cell shape. In a previous study, we showed that T. brucei TTLL6A and TTLL12B are required to regulate microtubule dynamics at the posterior cell pole. Here, using gene deletion, we show that the polyglutamylase TTLL1 is essential for the integrity of the highly organised microtubule structure at the cell pole, with a phenotype distinct from that observed in TTLL6A- and TTLL12B-depleted cells. Reduced polyglutamylation in TTLL1-deficient cells also leads to increased levels in tubulin tyrosination, providing new evidence for an interplay between the tubulin tyrosination and detyrosination cycle and polyglutamylation. We also show that TTLL1 acts differentially on specific microtubule doublets of the flagellar axoneme, although the absence of TTLL1 appears to have no measurable effect on cell motility.

[Quality assurance in plastic surgery--initial experiences with "breast reduction" tracer diagnosis]

Quality assurance has to be an integral part of medical work as it is required by actual health laws. "Tracers" have been used in different parts of medicine as a reliable method. In 1997 we started to establish an internal program for a quality assurance with five different tracers (breast augmentation, breast reduction, oncological and reconstructive breast surgery, liposuction). The outcome is prospectively documented using an operation-specific documentation form. Every three months, the results are discussed in a surgical audit. The overall complication rate after mamma reduction (n = 81) was reduced about 40% to 21% (mean reduction weight 1.7 kg). Therefore, these measurements could promptly improve the quality of treatment of our patients.