A gender-dependent analysis of Cushing's disease in childhood: pre- and postoperative follow-up.

OBJECTIVE: To analyse gender differences in the clinical presentation and recovery of paediatric patients with Cushing's disease (CD) after transsphenoidal surgery (TSS). Indeed, gender differences between paediatric patients with CD during presentation, after TSS and postoperative recovery have not been adequately studied. DESIGN: Data were obtained and retrospectively analysed from clinical reports and biochemical tests at the time of presentation, 5-9 days after TSS and at the 6 and 12 months postoperative follow-up visits to determine hypothalamic-pituitary-adrenal axis (HPAA) recovery. PATIENTS: Data from 102 paediatric patients (48 females, 54 males, mean age 12.9 ± 3.0) with CD who underwent TSS at the National Institute of Health (NIH) Clinical Center between 1997 and 2011. RESULTS: There was equal distribution of paediatric CD between males and females (53% vs 47%; n = 102, P = 0.484). Males were more likely than females to present with higher mean BMI Z-scores (2.2 ± 0.7 vs 1.9 ± 0.6, P = 0.0079), lower mean height Z-scores (-1.2 ± 1.3 vs -0.7 ± 1.1, P = 0.0467) and higher median plasma ACTH (12.2 vs 8.5 pmol/l; P = 0.0495). Females did not present more frequently with any single sign or symptom. No significant differences were found between males and females for CD cure rates 5-9 days after TSS (87.0% males vs 87.5% females, P = 1.0), long-term cure rates (86.5% vs 93.7%; n = 69; P = 0.4374) and HPAA recovery time (11.2 ± 2.5 vs 11.7 ± 2.5 months; n = 47; P = 0.1992). CONCLUSIONS: Paediatric CD is found to have equal distribution between males and females, but male patients present with elevated BMI and potentially shorter height and higher plasma ACTH. There is no significant difference in the cure rate or HPAA recovery time after TSS between males and females.

Investigation of the Importance of Protein 3D Structure for Assessing Conservation of Lysine Acetylation Sites in Protein Homologs.

Acetylation is a protein post-translational modification (PTM) that can affect a variety of cellular processes. In bacteria, two PTM Nε-acetylation mechanisms have been identified: non-enzymatic/chemical acetylation via acetyl phosphate or acetyl coenzyme A and enzymatic acetylation via protein acetyltransferases. Prior studies have shown that extensive acetylation of Nε-lysine residues of numerous proteins from a variety of bacteria occurs via non-enzymatic acetylation. In Escherichia coli, new Nε-lysine acetyltransferases (KATs) that enzymatically acetylate other proteins have been identified, thus expanding the repertoire of protein substrates that are potentially regulated by acetylation. Therefore, we designed a study to leverage the wealth of structural data in the Protein Data Bank (PDB) to determine: (1) the 3D location of lysine residues on substrate proteins that are acetylated by E. coli KATs, and (2) investigate whether these residues are conserved on 3D structures of their homologs. Five E. coli KAT substrate proteins that were previously identified as being acetylated by YiaC and had 3D structures in the PDB were selected for further analysis: adenylate kinase (Adk), isocitrate dehydrogenase (Icd), catalase HPII (KatE), methionyl-tRNA formyltransferase (Fmt), and a peroxide stress resistance protein (YaaA). We methodically compared over 350 protein structures of these E. coli enzymes and their homologs; to accurately determine lysine residue conservation requires a strategy that incorporates both flexible structural alignments and visual inspection. Moreover, our results revealed discrepancies in conclusions about lysine residue conservation in homologs when examining linear amino acid sequences compared to 3D structures.