Assigning Backbone NMR Resonances for Full Length Tau Isoforms: Efficient Compromise between Manual Assignments and Reduced Dimensionality

Tau protein is the longest disordered protein for which nearly complete backbone NMR resonance assignments have been reported. Full-length tau protein was initially assigned using a laborious combination of bootstrapping assignments from shorter tau fragments and conventional triple resonance NMR experiments. Subsequently it was reported that assignments of comparable quality could be obtained in a fully automated fashion from data obtained using reduced dimensionality NMR (RDNMR) experiments employing a large number of indirect dimensions. Although the latter strategy offers many advantages, it presents some difficulties if manual intervention, confirmation, or correction of the assignments is desirable, as may often be the case for long disordered and degenerate polypeptide sequences. Here we demonstrate that nearly complete backbone resonance assignments for full-length tau isoforms can be obtained without resorting either to bootstrapping from smaller fragments or to very high dimensionality experiments and automation. Instead, a set of RDNMR triple resonance experiments of modest dimensionality lend themselves readily to efficient and unambiguous manual assignments. An analysis of the backbone chemical shifts obtained in this fashion indicates several regions in full length tau with a notable propensity for helical or strand-like structure that are in good agreement with previous observations

Comparative study of the subjective and objective grading of ptosis surgery outcomes.

Aims To assess the results of blepharoptosis surgery in our hospital by subjective and objective grading of the outcome and comparing them to determine their degree of correlation. Methods Retrospective interventional case series report supplemented by postal questionnaires and telephonic patient surveys. The study included 107 eyelids of 78 patients. Using a simple grading system, surgical outcome was objectively graded as good, suboptimal, or poor. Outcome was also defined according to the patients' perspective as good, suboptimal, or poor. Level of agreement between the subjective and objective grading of the outcome was measured using a weighted kappa analysis. Results The objective results were classed as good¿68/107 (63.5%), suboptimal¿18 eyelids (16.8%), and poor¿21 eyelids (19.6%). The subjective results were obtainable in 91 eyelids and were good¿54/91 (59.3%), suboptimal¿8/91 (8.7%), and poor¿29/91 (32%). A mismatch between objective and subjective outcomes was seen in 16 eyelids. We saw a statistically significant correlation between the objective grading and the patients' perspective (P<0.001). Conclusion Our overall ptosis surgery results are comparable with rates previously reported. The subjective and objective outcomes of ptosis surgery may sometimes vary, but nevertheless exhibit substantive agreement when measured by this simple grading system