Analysis of 26 amino acids in human plasma by HPLC using AQC as derivatizing agent and its application in metabolic laboratory.

The present study reports the simultaneous analysis of 26 physiological amino acids in plasma along with total cysteine and homocysteine by high-performance liquid chromatography (HPLC) employing 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) as precolumn derivatizing reagent. Separations were carried out using Lichrospher 100 RP-18e (5 µm) 250 × 4.0 mm column connected to 100 CN 4.0 × 4.0 mm guard column on a quaternary HPLC system and run time was 53 min. Linearity of the peak areas for different concentrations ranging from 2.5 to 100 pmol/µL of individual amino acids was determined. A good linearity (R (2) > 0.998) was achieved in the standard mixture for each amino acid. Recovery of amino acids incorporated at the time of derivatization ranged from 95 to 106 %. Using this method we have established the normative data of amino acids in plasma, the profile being comparable to the range reported in literature and identified cases of classical homocystinuria, cobalamin defect/deficiency, non-ketotic hyperglycinemia, hyperprolinemia, ketotic hyperglycinemia, urea cycle defect and maple syrup urine disease.

Evaluation of micronutrient profile of North Indian children with cystic fibrosis: a case-control study.

BACKGROUND: Data on the micronutrient levels in children with cystic fibrosis (CF) are not available from developing countries, wherein the nutritional profile of children is quite different from that of Western countries. METHODS: Levels of fat-soluble vitamins (A, D, and E) and trace metals (iron, copper, and zinc) were measured in 27 CF cases and 27 controls. RESULTS: CF cases had significantly low levels of all studied micronutrients compared with controls, and the levels were even lower in cases with exacerbation than in stable CF cases. Prevalence of deficiency of vitamin D, vitamin E, iron, copper, and zinc was significantly higher in cases than in controls, whereas vitamin A deficiency was almost equal in both the groups. CONCLUSION: The prevalence of deficiency of vitamins A, D, and E and iron, copper, and zinc was high in CF cases, and their levels were significantly lower in cases than controls. CF cases should be regularly monitored for these micronutrients, and appropriate supplementation should be considered.

Bone density and bone health alteration in boys with Duchenne Muscular Dystrophy: a prospective observational study.

OBJECTIVES: Boys with Duchenne Muscular Dystrophy (DMD) are at increased risk for compromised bone health, manifesting as low-impact trauma long bone fractures and vertebral compression fractures. METHODS: In a prospective observational study, we studied bone health parameters in North Indian boys with DMD. We consecutively enrolled ambulatory boys with DMD on glucocorticoid therapy. Bone health was evaluated with X-ray spine, Dual-energy X-ray absorptiometry (DXA), serum calcium, vitamin D3 (25[OH]D), 1,25-dihyroxyvitamin D3 (1,25[OH]2D3), serum osteocalcin, osteopontin, and N terminal telopeptide of type 1 collagen (Ntx) levels. RESULTS: A total of 76 boys with DMD were enrolled. The median age was 8.5 (interquartile range [IQR] 7.04-10.77) years. Among these, seven (9.2%) boys had long bone fractures, and four (5.3%) had vertebral compression fractures. Fifty-four (71%) boys underwent DXA scan, and among these 31 (57%) had low bone mineral density (BMD, ≤-2 z-score) at the lumbar spine. The mean BMD z-score at the lumbar spine was -2.3 (95% confidence interval [CI] = -1.8, -2.8), and at the femoral neck was -2.5 (95% CI = -2, -2.9). 25(OH)D levels were deficient in 68 (89.5%, n=76) boys, and 1,25(OH)2D3 levels were deficient in all. Mean serum osteocalcin levels were 0.68 ± 0.38 ng/mL (n=54), serum osteopontin levels were 8.6 ± 4.6 pg/mL (n=54) and serum Ntx levels were 891 ± 476 nmol/L (n=54). Boys with low BMD received glucocorticoids for longer duration, in comparison to those with normal BMD (median, IQR [16.9 (6-34) months vs. 7.8 (4.8-13.4) months]; p=0.04). CONCLUSIONS: Bone health is compromised in North Indian boys with DMD. BMD at the lumbar spine is reduced in more than half of boys with DMD and nearly all had vitamin D deficiency on regular vitamin D supplements. Longer duration of glucocorticoid therapy is a risk factor for low BMD in our cohort.