CLSI-based transference of the CALIPER database of pediatric reference intervals from Abbott to Beckman, Ortho, Roche and Siemens Clinical Chemistry Assays: direct validation using reference samples from the CALIPER cohort.

Objectives: The CALIPER program recently established a comprehensive database of age- and sex-stratified pediatric reference intervals for 40 biochemical markers. However, this database was only directly applicable for Abbott ARCHITECT assays. We therefore sought to expand the scope of this database to biochemical assays from other major manufacturers, allowing for a much wider application of the CALIPER database.

Hematocrit correction does not improve glucose monitor accuracy in the assessment of neonatal hypoglycemia.

Background: The lack of accuracy of point of care (POC) glucose monitors has limited their use in the diagnosis of neonatal hypoglycemia. Hematocrit plays an important role in explaining discordant results. The objective of this study was to to assess the effect of hematocrit on the diagnostic performance of Abbott Precision Xceed Pro (PXP) and Nova StatStrip (StatStrip) monitors in neonates.

Missed follow-up opportunities using a two-step screening approach for gestational diabetes.

A 1-step approach for gestational diabetes (GDM) screening using a 75 g-oral glucose tolerance test (75 g-OGTT) has been recommended. We undertook an audit (January 2007-June 2010) to assess adherence to an existing 2-step approach (50 g-glucose challenge test followed by a 75 g-OGTT). Adherence was sub-optimal.

Establishment of reference intervals for bone markers in children and adolescents.

Objectives: To determine age and gender specific reference intervals for bone markers.

Design And Methods: Morning blood samples were collected after overnight fast from 356 healthy children (6 to 18 year-old) for the determination of bone marker levels, PTH and vitamin D(3). Multiple regression analysis was done to assess the effect of factors that could influence the bone marker levels; the central 95% reference interval and their 90% CI were calculated.

Pediatric critical values: laboratory-pediatrician discourse.

Objectives: To review pediatric critical values after consultation with departmental pediatricians.

Methods: An electronic survey with the critical value list of 26 high or low abnormal chemistry laboratory values of 12 analytes was circulated to pediatricians. The survey results were presented to a focus group of 3 pediatricians for comments and review.

Prevalence of low bone mass and deficiencies of vitamins D and K in pediatric patients with cystic fibrosis from 3 Canadian centers.

Objective: In this cross-sectional observational study, we assessed both vitamins D and K status and bone health in pancreatic insufficient pediatric patients with cystic fibrosis from 3 Canadian cystic fibrosis centers.

Methods: Eighty-one patients who had cystic fibrosis and were clinically stable for at least 3 months were enrolled. At the time of the clinic visit, anthropometric variables, lung function, pubertal status, intake of calcium and vitamins D and K, and physical activity were assessed.

Clinical implication of the difference between transcutaneous bilirubinometry and total serum bilirubin for the classification of newborns at risk of hyperbilirubinemia.

Objectives: 1) To determine the relationship between transcutaneous bilirubin measurements (TcB), performed using BiliCheck or Minolta Air-Shields JM-103, and total serum bilirubin levels (TSB) and 2) to evaluate the predictive accuracy of TcB measurements for risk using the nomogram recommended by the Canadian Pediatric Society (CPS).

Methods: A total of 154 healthy term neonates from the newborn nursery at McMaster Children's Hospital meeting the inclusion criteria were enrolled. TcB measurements were performed within 30 min of obtaining the TSB measurement.

An open-label dose-response study of lymphocyte glutathione levels in healthy men and women receiving pressurized whey protein isolate supplements.

Background: High-pressure treatment of whey protein may increase digestibility and bioavailability of cysteine. The purpose of the study was to determine whether total lymphocyte glutathione (gamma-glutamyl-cysteinyl-glycine [GSH]) levels (oxidized+reduced) can be augmented from three different doses of pressurized whey protein supplements in a dose-dependent manner over a 2-week period.

Methods: Eighteen healthy males and 18 healthy females were randomized into three different groups, with 31 finishing the study.

Effect of whey protein to modulate immune response in children with atopic asthma.

Background: Levels of glutathione (GSH) in antigen-presenting cells promote a T-helper type 2 (Th2) cytokine response in mice. We have previously demonstrated that we can increase intracellular GSH levels in healthy young adults using a whey-based oral supplement (HMS90). We hypothesized that such supplementation in children with atopic asthma, a Th2 cytokine disease, would improve lung function and decrease atopy.

Screening for hypoglycemia at the bedside in the neonatal intensive care unit (NICU) with the Abbott PCx glucose meter.

Background: Point of care (POC) glucose meters are routinely used as a screening tool for hypoglycemia in a neonatal setting. Glucose meters however, lack the same accuracy as laboratory instruments for glucose measurement. In this study we investigated potential reasons for this inaccuracy and established a cut off value for confirmatory testing.

Derivation and validation of cystatin C-based prediction equations for GFR in children.

Background: Cystatin C (CysC) may be a better marker of glomerular filtration rate (GFR) than serum creatinine (SCr) level. Few studies derived CysC-based GFR prediction equations for children. Objectives of this study are to: (1) derive CysC-based GFR prediction equations for children, and (2) compare these equations with published formulae.

Pediatric reference intervals for bone markers.

Bone markers are specific bone-derived molecules that reflect bone remodeling activity and can be classified into two categories: bone formation and bone resorption markers. Children have significantly elevated bone marker levels due to high skeletal growth velocity and rapid bone turnover during childhood growth. Many physiological and pathological processes may influence bone metabolism and bone marker concentrations during childhood growth.

Induced sputum in cystic fibrosis: within-week reproducibility of inflammatory markers.

Unlabelled: Analysis of induced sputum has provided significant insight into the inflammatory response in chronic respiratory diseases such as asthma. The thick, tenacious nature of cystic fibrosis (CF) sputum presents certain challenges to such evaluation. We describe the development of a methodology to assess CF sputum, and the within-week reproducibility (to limit the possibility of any change in clinical status) of cellular and inflammatory markers.

Improved glutathione status in young adult patients with cystic fibrosis supplemented with whey protein.

Background: The lung disease of cystic fibrosis is associated with a chronic inflammatory reaction and an over abundance of oxidants relative to antioxidants. Glutathione functions as a major frontline defense against the build-up of oxidants in the lung. This increased demand for glutathione (GSH) in cystic fibrosis may be limiting if nutritional status is compromised.