PubMed Health⌕ Search

Biomedical subjects

D Kia

Publications and source records attributed to D Kia.

7 recordsLinked to original sources

Problems associated with the use of exclusion-diffusion chromatography for identification of zinc ligands in human milk.

The effect of operating conditions used in gel filtration, i.e. the type of gel and elution buffer, on the qualitative and quantitative distribution of zinc in human milk was studied. The gels used were Sephadex G10 and G15, Biogel P2 and Trisacryl GF05. The three elution buffers used were 0.05 M Tris-HCl, pH = 7.4, 0.05 M Tris-acetate, pH = 7.4 and 0.1 M ammonium acetate, pH = 6.5. Ultrafiltration was used as an additional technique for the verification of a number of the results obtained. Zinc ligands in human milk are, possibly, serum albumin and citric acid. The results showed a gel effect, which was greater on the identification and quantitation of the low molecular-weight ligand (the percentage of zinc associated with citric acid was lower with Biogel P2). The elution buffer had a considerable effect, particularly when quantifying the protein-bound fraction. The percentage of zinc coeluted with proteins decreased when the elution buffer contained acetate ions. The combination of Sephadex G15 and 0.05 M Tris-HCl, pH = 7.4 was found to be the best compromise. Zinc distribution with this system was 35-44% of zinc coeluted with proteins and 18-22% with citric acid.

Chromatography, Gel↗

Simultaneous determination of retinol, alpha-tocopherol and beta-carotene in serum by isocratic high-performance liquid chromatography.

A simultaneous determination of retinol, alpha-tocopherol and beta-carotene in serum by high-performance liquid chromatography is described. Total analysis time is 13 min. A reversed-phase (Ultrasphere ODS, 5 microns) column is used with a mobile phase of acetonitrile-methanol-dichloromethane (70:10:20, v/v/v) and a flow-rate of 1.2 ml/min. Retinol is monitored at 325 nm, alpha-tocopherol at 292 nm and beta-carotene at 450 nm. Serum is deproteinized with ethanol containing the internal standard (alpha-tocopherol acetate), then extracted with hexane. The evaporated organic layer is reconstituted with the mobile phase and injected. The choice of the eluent is discussed, as well as the choice of an internal standard and the need for an antioxidant during the extraction step. Sixteen different eluents are compared in terms of analysis time and selectivity. The linear concentration ranges (retinol 0.016-13.7 microM, alpha-tocopherol 0.18-91.8 microM, beta-carotene 0.05-5.75 microM), within-run coefficients of variation (retinol less than 7%; alpha-tocopherol less than 8%, beta-carotene less than 7%), between-run coefficients of variation (retinol less than 13%, alpha-tocopherol less than 9%, beta-carotene less than 8%) and recoveries (retinol greater than 95%, alpha-tocopherol greater than 91%, beta-carotene greater than 80%) are suitable for clinical investigations. Serum reference values were found to be 2.47 +/- 0.61 microM (retinol), 30.5 +/- 6.8 microM (alpha-tocopherol) and 0.91 +/- 0.55 microM (beta-carotene). A significant difference (p less than 0.001) between males and females was found for retinol.

Carotenoids↗

pH-tested reflux without hiatus hernia.

Gastroesophageal reflux was tested for with a pH telemetry capsule. In 29 individuals in whom no hiatus hernia was demonstrated on barium esophagram, the transverse diameter of the intrahiatal esophagus was compared to that of the intrathoracic. When the width of the intrahiatal esophagus was two-thirds or less that of the intrathoracic, pH-proven reflux was an infrequent event. When wider, reflux occurred with high frequency.

Gastric Acidity Determination↗

Truncal vagotomy and pyloroplasty for duodenal ulcer.

Two hundred sixty-five patients who underwent vagotomy and pyloroplasty for duodenal ulcer disease were observed postoperatively, 220 for two to ten years, with an average follow-up of five years. Vagotomy and pyloroplasty carried a higher overall recurrence rate (3.6%) than did subtotal gastrectomy and vagotomy (1%), largely because of the high ulcer recurrence rate more than two years after operation for massive bleeding (9.2%) rather than that following elective operation (1.8%). Thirty-five percent of these patients with recurrent ulcers did well with medical management and did not require a second operation. The mortality of vagotomy and pyloroplasty for a massively bleeding ulcer (11%) was less than that following subtotal gastrectomy (21%). The mortality of elective vagotomy and pyloroplasty was 1%.

Adult↗

A new hyrogen ion telemetry technique for evaluating gastroesophageal reflux.

A new pH capsule telemetry technique was used to measure the pH fluxes in the upper part of the gastrointestinal tract in normal volunteers, symptomatic patients and in those with hiatal herniorrhaphy during the preoperative and postoperative period. The Darvon-sized pH capsule is swallowed with ease and with minimal discomfort by a fasting patient. The pH of the surrounding media activates an FM radio transmitter within the capsule to emit a continuous radio signal which is converted by a receiver to a linear graph on a strip chart recorder. This pH capsule telemetry test is easy to perform on an ambulatory basis and allows an accurate and reproducible determination of the presence or absence of esophageal reflux in patients with and without a hiatal hernia. Its correlation with symptomatic reflux is higher than that found with a conventional gastrointestinal series examination. The technique allows a much clearer distinction to be made between those patients with real symptomatic esophagitis secondary to actual reflux and those with other esophageal, cardiac or pulmonary symptoms existing withour reflux. This study also reveals a consistently lower fasting gastric pH in patients with signs and symptoms of reflux than in normal individuals without reflux. The technique enabled a more accurate assessment of the efficacy of hiatal hernia repair and revealed a reduced degree of esophageal reflux in those patients who had undergone successful repair with fundic plication.

Clinical Trials as Topic↗