* The method most commonly used for routinely measuring MTX in clinical laboratories is FPIA
. The DAMPA metabolite exhibits high cross-reactivity with most MTX immunoassays.
When the aliquots of drug-free serum pool were supplemented with Asian, American, and Indian ginsengs, significant apparent digoxin concentrations were observed using the FPIA
(range, 0.35-0.71 ng/mL, digoxin equivalent), but no apparent digoxin concentrations were observed using the TIA.
 Nonstandard abbreviations: tHcy, total homocysteine; CVD, cardiovascular disease; MMA, methylmalonic acid; FPIA
, fluorescence polarization immunoassay; GC-MS, gas chromatography-mass spectrometry; MS-MS, tandem mass spectrometry; MTHFR, methylenetetrahydrofolate reductase; CBS, cystathionine 0-synthase; NTD, neural tube defect; and holoTC, holotranscobalamin.
 Nonstandard abbreviations: GC-MS, gas chromatography-mass spectrometry; MDA-de, ([+ or -])-3,4-methylenedioxyamphetamine-[d.sub.5]; MBHFBA, N-methyl-bis(heptafluorobutyramide); FPIA
, fluorescence polarization immunoassay; DAD, photodiode array detection; HP, Hewlett-Packard; SIM, single-ion monitoring; and HFBA, heptafluorobutyramide.
Laboratories were grouped by the type of methodology performed: (a) HPLC-FD, further subdivided by the types of reduction [tributylphosphine (TBP), Na[BH.sub.4], tris-2-carboxyethylphosphine (TCEP)] and derivatization [ammonium 7-fluoro-2,1,3-benzoxadiazole-4-sulfonate (SBDF) or monobromobimane (MBrB)] agents used; (b) HPLC-ED; (c) FPIA
; (d) amino acid analyzer with ninhydrin detection; or (e) LC-MS/MS.
The patient produced a third urine, on November 13, 2001, that was also positive for cocaine metabolite (qualitative, >300 [micro]g/L by FPIA
Digoxin-like immunoreactive substance: monoclonal and polyclonal RIA and FPIA
In conclusion, heptaminol exhibits cross-reactivity (;0.06%) with the AxSYM FPIA
Amphetamine/Methamphetamine II assay, but gives false-positive results only with high urine concentrations of heptaminol.
To rule out the possibility that the observation of higher MEGX concentrations in uremic subjects was an artifact attributable to cross-reactivity with the TDx FPIA
by other lidocaine metabolites that may have accumulated in such patients, we compared the results of the FPIA
with those of a highly specific HPLC method in three healthy volunteers and three patients with severe renal dysfunction.
Doses of Tacrolimus were adjusted as per their serum levels by Fluorescence Polarization Immunoassay (FPIA
Petroleum service contractors shall also be entitled to Filipino Participation Incentive Allowance (FPIA
) at a minimum of 1.5-percent and maximum of 7.5-percent of gross proceeds; cost recovery of up to 70-percent of gross income from petroleum production in any calendar year with the unrecovered costs to be carried over in the succeeding calendar years.
Additionally, in the subgroup analysis of method of measurement, the positive association was still significant in studies using HPLC (OR = 1.29; 95% CI: 1.6, 1.44), while the association was not significant in studies using GC-MS and FPIA
. Details can be seen in Table 2.