Biomedical subjects

Vijaylaxmi Grey

Publications and source records attributed to Vijaylaxmi Grey.

4 recordsLinked to original sources

PubMed2006

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. Measurements of bone markers may be useful in investigating skeletal diseases in children and monitoring the response to treatment. This review documents recent advances in analytical methods, preanalytical considerations related to each marker and particularly highlights the most valuable bone formation markers, bone alkaline phosphatase and osteocalcin, and bone resorption markers, pyridinium cross-links and cross-linked telopeptides. Age- and sex-specific pediatric reference intervals and their limitations in clinical application are also discussed.

Biomarkers↗

PubMed2006

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. METHODS: Patients younger than 18 years undergoing iothalamate GFR (IoGFR) testing were studied prospectively. Data collected were age, sex, CysC level, SCr level, IoGFR, height, weight, and diagnosis. By using linear regression, 2 equations were derived and compared with 3 previously published formulae by using Bland-Altman analysis and diagnostic characteristics. Local coefficients were derived for comparison formulae. RESULTS: There were 111 GFR tests from 103 patients (age, 12.7 +/- 4.7 years; IoGFR, 73.6 +/- 35.7 mL/min/1.73 m(2) [1.23 +/- 0.60 mL/s/1.73 m(2)]; 60% male; and 25% post-renal transplantation). The 2 equations derived were the CysEq (including CysC level) and the CysCrEq (including CysC and SCr levels). Overall, the 2 new equations had bias and precision similar to previously published formulae when local coefficients were used. However, in patients with a renal transplant or spina bifida, the 2 new equations were less biased and more precise. All CysC-based equations performed better than the Schwartz formula. CONCLUSION: This study provides 2 CysC-based GFR prediction equations that are accurate, precise, and sensitive for detecting abnormal GFRs. Three previously published CysC GFR prediction equations have been validated for the first time. Prediction equations based on CysC level are likely to provide more accurate estimates of GFR than SCr-based equations.

Adolescent↗

PubMed2004

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. METHODS: Seventeen young adults [9 males, 8 females, mean age 24 (5), median (quartile range) years, percentage of predicted FEV(1) = 64.0 (18.0%)] with CF underwent sputum inductions on the Monday and Thursday of the same week. Patients were pretreated with 400 microg salbutamol and subsequently inhaled 5% saline via a breath enhanced nebulizer. Every 3-min nebulization was interrupted to allow for expectoration of sputum into a polypropylene pot. Sputum samples were dispersed with a solution of dithiothreitol (DTT) and deoxyribonuclease to allow for analysis of total cell count (TCC) and percentage neutrophils (%Neut). Measurement of tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), and neutrophil elastase was performed on samples dispersed with DTT alone. RESULTS: There were no significant differences between the measurements taken in the same week. Values for Day 1 versus Day 2 were as follows: TCC 20.8 (6.4) vs. 17.6 (2.5) x 10(6) cells/ml; %Neut: 94.1 (0.0) vs. 95.4 (0.5) %; TNF-alpha 7.5 (26.0) vs. 21.0 (44.0) pg/ml; IL-8 610.0 (422.0) vs. 524.0 (587.0) ng/ml and neutrophil elastase 110.0 (19.75) vs. 49.75 (60.75) microM. High intraclass correlation coefficients (ICC) for TCC, %Neut, TNF-alpha IL-8 and neutrophil elastase were found (ICC = 0.76, 0.82, 0.93, 0.82, 0.74, respectively). CONCLUSIONS: The method developed here for the analysis of CF sputum shows good reproducibility and can be used to evaluate therapeutic interventions in patients with cystic fibrosis.

Adult↗

PubMed2003

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. We sought to increase glutathione levels in stable patients with cystic fibrosis by supplementation with a whey-based protein. METHODS: Twenty-one patients who were in stable condition were randomly assigned to take a whey protein isolate (Immunocal, 10 g twice a day) or casein placebo for 3 months. Peripheral lymphocyte GSH was used as a marker of lung GSH. Values were compared with nutritional status and lung parameters. RESULTS: At baseline there were no significant differences in age, height, weight, percent ideal body weight or percent body fat. Lymphocyte GSH was similar in the two groups. After supplementation, we observed a 46.6% increase from baseline (P < 0.05) in the lymphocyte GSH levels in the supplemented group. No other changes were observed. CONCLUSION: The results show that dietary supplementation with a whey-based product can increase glutathione levels in cystic fibrosis. This nutritional approach may be useful in maintaining optimal levels of GSH and counteract the deleterious effects of oxidative stress in the lung in cystic fibrosis.

Adolescent↗