The long-term safety and effectiveness of growth hormone treatment in Japanese children with short stature born small for gestational age.

This study aimed to characterize the safety and effectiveness of GH treatments, in usual clinical practice, in children with short stature born small for gestational age (SGA). This was a multicenter, open-label, non-interventional study (NCT01110928) conducted at 150 sites in Japan (2009-2018). The primary objective was to assess the type and frequency of serious adverse drug reactions (SADRs) associated with long-term GH use. Overall, 452 naïve and 46 non-naïve (previously treated) children were enrolled. GH treatment was well­tolerated, with SADRs occurring in 1.3% (6/452) and 0% (0/46) of naïve and non-naïve children, respectively. No new safety concerns or notable changes in glucose metabolism were identified during long-term treatment. Altogether, 57 children (32 naïve and 25 non-naïve) reached near adult height (NAH). In naïve and non-naïve children, mean ± standard deviation (SD) height standard deviation score (SDS) at NAH were -2.03 ± 0.77 and -1.53 ± 0.81, respectively, representing a change of +0.85 ± 0.72 and +1.24 ± 0.66 from baseline height SDS, respectively. Mean treatment duration to NAH was 4.29 (naïve) and 7.26 (non-naïve) yr. Thus, long-term GH treatment for short stature in children born SGA was confirmed to have a good safety profile and was effective for improving adult height.

Dynamic, ligand-dependent conformational change triggers reaction of ribose-1,5-bisphosphate isomerase from Thermococcus kodakarensis KOD1.

Ribose-1,5-bisphosphate isomerase (R15Pi) is a novel enzyme recently identified as a member of an AMP metabolic pathway in archaea. The enzyme converts d-ribose 1,5-bisphosphate into ribulose 1,5-bisphosphate, providing the substrate for archaeal ribulose-1,5-bisphosphate carboxylase/oxygenases. We here report the crystal structures of R15Pi from Thermococcus kodakarensis KOD1 (Tk-R15Pi) with and without its substrate or product. Tk-R15Pi is a hexameric enzyme formed by the trimerization of dimer units. Biochemical analyses show that Tk-R15Pi only accepts the α-anomer of d-ribose 1,5-bisphosphate and that Cys(133) and Asp(202) residues are essential for ribulose 1,5-bisphosphate production. Comparison of the determined structures reveals that the unliganded and product-binding structures are in an open form, whereas the substrate-binding structure adopts a closed form, indicating domain movement upon substrate binding. The conformational change to the closed form optimizes active site configuration and also isolates the active site from the solvent, which may allow deprotonation of Cys(133) and protonation of Asp(202) to occur. The structural features of the substrate-binding form and biochemical evidence lead us to propose that the isomerase reaction proceeds via a cis-phosphoenolate intermediate.