Conscious sedation of the pediatric patient for suturing: a survey

No single drug or combination of drugs was used routinely in pediatric emergency departments to sedate children for suturing. A meperidine-promethazine-chlorpromazine "cocktail" was chosen most frequently. Many physicians were dissatisfied with the method they selected, however, leading some to experiment with newer medications such as fentanyl. The American Academy of Pediatrics (AAP) guidelines for the elective use of conscious sedation, specifically, those regarding monitoring during sedation and discharge post sedation, were not adhered to uniformly. Further study of conscious sedation in children is needed.     

The relative survival of COPD patients on long-term oxygen therapy in Australia: A comparative study

OBJECTIVE: The survival of patients with COPD on long-term oxygen therapy (LTOT) has been studied using both univariate and multivariate procedures. There has been only one previous report of relative survival. Relative survival takes into account the risk of death due to increasing age. The objective of this study was to determine the relative survival of a group of South Australian patients prescribed home oxygen therapy for COPD. METHODOLOGY: A method proposed by Hakulinen was used to determine relative survival. The results were compared with the relative survival of a similar group of French COPD patients. RESULTS: A total of 505 COPD patients (249 males, 256 females) were included in the survival analysis. Relative survival corrected for life expectancy was 78.1%, 56.7%, 23.1% and 1.1% at 1, 2, 5 and 10 years, respectively, which was less than that reported in a recent French study of comparable patients. Our patients were similar with respect to age, severity of hypoxaemia and oxygen usage to those in the French study. CONCLUSIONS: Using relative survival analysis, Australian LTOT patients with COPD have worse outcomes than some European patients. Factors contributing to the excess mortality in South Australian COPD patients need to be investigated.     

Signal peptide mutations in RANK prevent downstream activation of NF‐κB

Familial expansile osteolysis and related disorders are caused by heterozygous tandem duplication mutations in the signal peptide region of the gene encoding receptor activator of NF‐κB (RANK), a receptor critical for osteoclast formation and function. Previous studies have shown that overexpression of these mutant proteins causes constitutive activation of NF‐κB signaling in vitro, and it has been assumed that this accounts for the focal osteolytic lesions that are seen in vivo. We show here that constitutive activation of NF‐κB occurred in HEK293 cells overexpressing wild‐type or mutant RANK but not in stably transfected cell lines expressing low levels of each RANK gene. Importantly, only cells expressing wild‐type RANK demonstrated ligand‐dependent activation of NF‐κB. When overexpressed, mutant RANK did not localize to the plasma membrane but localized to extensive areas of organized smooth endoplasmic reticulum, whereas, as expected, wild‐type RANK was detected at the plasma membrane and in the Golgi apparatus. This intracellular accumulation of the mutant proteins is probably the result of lack of signal peptide cleavage because, using two in vitro translation systems, we demonstrate that the mutations in RANK prevent cleavage of the signal peptide. In conclusion, signal peptide mutations lead to accumulation of RANK in the endoplasmic reticulum and prevent direct activation by RANK ligand. These results strongly suggest that the increased osteoclast formation/activity caused by these mutations cannot be explained by studying the homozygous phenotype alone but requires further detailed investigation of the heterozygous expression of the mutant RANK proteins. © 2011 American Society for Bone and Mineral Research     

Analytical characteristics of cleavable isotope-coded affinity tag-LC-tandem mass spectrometry for quantitative proteomic studies

Quantitative proteomic studies using cleavable isotope-coded affinity tags (cICAT) in concert with tandem mass spectrometry (MS/MS) permit unbiased comparisons between biologically distinct samples. We sought to determine the analytical characteristics of cICAT-based studies by examining the cumulative results of multiple, separate cICAT-based experiments involving human lymphoma-derived cells. We found that the number of identified proteins increased with larger numbers of fractions analyzed. The majority of proteins were identified by single peptides. Only 24 to 41% of the peptides contained cysteine residues, but 85% of the cysteine-containing peptides yielded quantification data. Approximately 28% of all identified proteins yielded quantification data, with 57% of these being differentially expressed by at least 1.5-fold. The quantification ratios of peptides for proteins with multiple quantified peptides were concordant in trend in 87% of instances. cICAT-labeled peptides identified proteins in all subcellular compartments without significant bias. Analysis of the flow-through fraction did not increase the number of peptides identified per protein. Our studies indicate that cICAT-LC-MS/MS yields quantifications primarily based on single peptides, and analysis of flow-through peptides does not contribute signifi-cantly to the results. Nevertheless, identifications based on single cICAT-labeled peptides with tryptic ends provide sufficiently reliable protein identifications and quantification information in cICAT-LC-MS/MS-based proteomic studies.