Biomedical subjects

L Choinière

Publications and source records attributed to L Choinière.

3 recordsLinked to original sources

PubMed2001

In vivo variability of TMA oxidation is partially mediated by polymorphisms of the FMO3 gene.

Trimethylaminuria (TMAU) results from an accumulation of an excessive amount of unoxidized trimethylamine that is excreted in urine and body secretions. Mutations of the flavin-containing monooxygenase 3 (FMO3) gene (a hepatic phase I drug-metabolizing enzyme) account for the severe recessively encoded form of this condition. We have previously described a number of FMO3 polymorphisms which in vitro exhibit reduced substrate affinity for several FMO substrates. Here we show that three prevalent polymorphisms (E158K, V257M, and E308G) inherited in particular combinations confer a slight decrease in TMA oxidation under normal physiological conditions, which may be clinically "silent." With the use of substrate loading or with the interaction of other known modulators of FMO3 activity such as hormonal influences, these genotypes may predispose to mild TMAU.

Alleles↗

PubMed1999

Measurement of trimethylamine and trimethylamine N-oxide independently in urine by fast atom bombardment mass spectrometry.

We report a method based upon fast atom bombardment mass spectrometry (FAB-MS) and stable isotope dilution techniques for the measurement of urinary trimethylamine (TMA) and trimethylamine N-oxide (TMAOx). TMA is extracted from urine that was spiked with (15)N-labeled TMA. The extracted TMA isotopomers are quaternized with trideuteromethyl iodide and analyzed in FAB-MS with hexaethylene glycol as matrix. TMAOx is measured by evaporation of another sample of the urine spiked with (15)N-labeled TMAOx on the FAB probe and analyzed as for the TMA. The method allows the ready and simple distinguishing of controls and patients with TMAuria, and is useful in monitoring patients with the disorder. We give examples of its use in determining normal control ranges for these metabolites and in evaluating patients.

Case-Control Studies↗

PubMed1978

Recurrent duodenal ulcer.

In the past 6 years 26 patients underwent operation for recurrent duodenal ulcer after what was considered to be an "adequate" initial operation. In such patients it is necessary first to demonstrate the recurrent ulcer and then to determine its cause. Endoscopy was the best means of confirming the diagnosis. The cause of recurrence was determined by tests for gastric acid secretion; 70% of patients had hyperacidity and 80% had positive results of the Hollander test. Treatment is always surgical but varies depending on the type of initial surgery, the primary cause of recurrence and the condition of the patient. Ten patients underwent vagotomy, 12 had vagotomy with antrectomy and 4 had antrectomy alone. There were no operative deaths but nine (35%) patients experienced 11 significant postoperative complications.

Adult↗