Idiopathic club foot treated with the Ponseti method. Clinical and sonographic evaluation of Achilles tendon tenotomy. A review of 221 club feet

SummaryThe Ponseti method applied to treating idiopathic club foot consists in placing successive corrective casts, possibly an Achilles tendon tenotomy, then derotation braces, a method that has proven its efficacy. This study compared 221 cases of club foot treated with this method between 2002 and 2007 divided into two groups, based on whether or not Achilles tendon tenotomy was performed. Assessment was both clinical and sonographic. We observed clear improvement of the results in the group that underwent Achilles tendon tenotomy and a significant difference in the rate of secondary surgery. The sonographic evaluation also showed improvement of the morphological results. We now systematically propose Achilles tendon tenotomy however severe club foot may be

Arterial spin labeling in clinical pediatric imaging

International audienceArterial spin labeling (ASL) perfusion- weighted magnetic resonance imaging is the only approach that enables direct and non-invasive quantitative measurement of cerebral blood flow in the brain regions without administration of contrast material and without radiation. ASL is thus a promising perfusion imaging method for assessing cerebral blood flow in the pediatric population. Concerning newborns, there are current limitations because of their smaller brain size and lower brain perfusion. This article reviews and illustrates the use of ASL in pediatric clinical practice and discusses emerging cerebral perfusion imaging applications for children due to the highly convenient implementation of the ASL sequence. (C) 2015 Editions francaises de radiologie. Published by Elsevier Masson SAS. All rights reserved

X-ray crystallographic and computational studies of the O2-tolerant [NiFe]-hydrogenase 1 from Escherichia coli.

The crystal structure of the membrane-bound O(2)-tolerant [NiFe]-hydrogenase 1 from Escherichia coli (EcHyd-1) has been solved in three different states: as-isolated, H(2)-reduced, and chemically oxidized. As very recently reported for similar enzymes from Ralstonia eutropha and Hydrogenovibrio marinus, two supernumerary Cys residues coordinate the proximal [FeS] cluster in EcHyd-1, which lacks one of the inorganic sulfide ligands. We find that the as-isolated, aerobically purified species contains a mixture of at least two conformations for one of the cluster iron ions and Glu76. In one of them, Glu76 and the iron occupy positions that are similar to those found in O(2)-sensitive [NiFe]-hydrogenases. In the other conformation, this iron binds, besides three sulfur ligands, the amide N from Cys20 and one Oε of Glu76. Our calculations show that oxidation of this unique iron generates the high-potential form of the proximal cluster. The structural rearrangement caused by oxidation is confirmed by our H(2)-reduced and oxidized EcHyd-1 structures. Thus, thanks to the peculiar coordination of the unique iron, the proximal cluster can contribute two successive electrons to secure complete reduction of O(2) to H(2)O at the active site. The two observed conformations of Glu76 are consistent with this residue playing the role of a base to deprotonate the amide moiety of Cys20 upon iron binding and transfer the resulting proton away, thus allowing the second oxidation to be electroneutral. The comparison of our structures also shows the existence of a dynamic chain of water molecules, resulting from O(2) reduction, located near the active site

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Reply to: Comment on "Dual-energy synchroton X ray measurements of rapid soil density and water content changes in swelling soils during infiltration" by Kirby, J.M. and Smiles, D.E., Published in: Water Resources Research, vol. 35, nø 11, pg 3585-3587, 1999International audienc