Discrepancy between DXA and CT-based assessment of spine bone mineral density.

Purpose: Adequate bone mineral density (BMD) is necessary for success in spine surgery. Dual-energy X-ray absorptiometry (DXA) is the gold standard in determining BMD but may give spuriously high values. Hounsfield units (HU) from computed tomography (CT) may provide a more accurate depiction of the focal BMD encountered during spine surgery.

Structural and functional analysis of an l-serine O-phosphate decarboxylase involved in norcobamide biosynthesis.

Structural diversity of natural cobamides (Cbas, B vitamers) is limited to the nucleotide loop. The loop is connected to the cobalt-containing corrin ring via an (R)-1-aminopropan-2-ol O-2-phosphate (AP-P) linker moiety. AP-P is produced by the l-threonine O-3-phosphate (l-Thr-P) decarboxylase CobD.