A colorimetric competitive displacement assay for the evaluation of catalytic peptides

An assay based on competitive dye displacement was adapted to detect the formation of aldol product in crude reaction mixtures, and was used to evaluate minimal peptide aldol catalysts.</p

Fatal anaphylactoid response to protamine after percutaneous transluminal coronary angioplasty

A generalized skin erythema and severe hypotension developed following administration of protamine for the reversal of heparin anticoagulation after an unsuccessful attempt at percutaneous transluminal angioplasty in a patient who had never been exposed to protamines before. Evidence of classical pathway complement activation was present indicating that this reaction could have been triggered by a non-immunological mechanism. The patient could not adequately be resuscitated because of the presence of severe coronary artery diseas

Diversity of new Martian crater clusters informs meteoroid atmospheric interactions

We investigated 634 crater clusters on Mars detected between 2007 and 2021, which represent more than half of all impacts discovered in this period. Crater clusters form when meteoroids in the 10 kg to 10 ton mass range break-up in Mars' atmosphere to produce a few to a few hundred fragments that hit the ground. The properties of the clusters can inform our understanding of meteoroid properties and the processes that govern their fragmentation. We mapped individual craters $>$1 m within each cluster and defined a range of cluster properties based on the spatial and size distributions of the craters. The large data set, with over eight times more cluster observations than previous work, provides a more robust statistical investigation of crater cluster parameters and their correlations. Trends in size, dispersion and large crater fraction with elevation support weak atmospheric filtering of material. The diversity in the number of individual craters within a cluster, and their size-frequency distributions, may reflect either a diversity in fragmentation style, fragility or internal particle sizes.Comment: 12 pages, 12 figures at the en

Metastasis-inducing S100A4 protein is associated with the disease activity of rheumatoid arthritis

Objectives. To evaluate the association between metastasis-inducing protein S100A4 and disease activity in patients with RA, and to demonstrate the effect of TNF-alpha blocking therapy on plasma levels of S100A4 in these patients. Methods. Plasma levels of the S100A4 protein were analysed in 40 anti-TNF-alpha naive patients with active RA. Of the 40 patients, 25 were treated with adalimumab and monitored over time. The conformational form of S100A4 was analysed using size-exclusion gel chromatography. TNF-alpha mRNA expression and protein synthesis were analysed by RT-PCR and ELISA, respectively. Results. Baseline levels of S100A4 were significantly correlated with disease activity in RA patients (r = 0.41; P < 0.01). After 12 weeks of treatment with adalimumab, there was an obvious shift in the conformations of S100A4 from the multimeric to the dimeric forms, whereas the total levels of the S100A4 protein remained unchanged. This suggests that the bioactive (multimer) S100A4 may decline in response to successful treatment with adalimumab. In addition, we showed significant up-regulation of TNF-alpha mRNA (P < 0.01), and protein release to the cell culture medium of monocytes stimulated with the S100A4 multimer compared with those treated with the dimer and to the unstimulated monocytes (P < 0.001). Conclusions. This is the first study to show that the levels of the S100A4 protein are correlated with RA disease activity. Furthermore, only the bioactive form, but not the total amount of S100A4, decreases after successful TNF-alpha blocking therapy in patients with RA. These data support an important role for the S100A4 multimer in the pathogenesis of R