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R H Drost

Publications and source records attributed to R H Drost.

32 records · Page 2Linked to original sources
PubMed1979

Evaluation of the manual enzyme immunoassay (EMIT) procedure for determination of serum thyroxine.

Our experience with the determination of thyroxine (T4) in serum using a homogeneous enzyme immunoassay technique (EMIT, Syva Corp.) is reported. The intra-assay precision of the EMIT Manual Thyroxine Assay was investigated with 2 different calibrator concentrations and showed coefficients of variation varying from 5--2% for thyroxine concentrations of 40 and 120 micrograms/l thyroxine respectively. The inter-assay precision was investigated with different series of calibrators and serum specimens. Coefficients of variation for the calibrators varied from 35--5% in the range of 20--200 micrograms/l thyroxine and for the serum specimens in the range of 8--232 micrograms/l thyroxine from 50--4%. The recovery of various amounts of thyroxine added to thyroxine-free serum varied between 91--103%. The cross reactivity of structurally related compounds such as: monoiodothyronine, diiodothyronine, triiodothyronine, triiodothyroacetic acid and tetraiodothyroacetic acid was investigated. Serum samples of 100 patients were analysed by EMIT and radioimmunoassay (T4 RIA (PEG), Abbott Lab.). A good correlation was found between the EMIT and RIA assay (r = 0.96, slope = 0.96 and y-intercept = 3.37 micrograms/l).

Cross Reactions↗
PubMed1977

A comparative study of the homogeneous enzyme immunoassay (EMIT) and two radioimmunoassays (RIA's) for digoxin.

Our experience with the determination of digoxin in plasma or serum using a homogeneous enzyme immunoassay technique (EMIT) is reported. The day-to-day precision of the EMIT digoxin assay was investigated with different series of calibrators. Coefficients of variation varied from 10 to 25 percent in the range of 0.65--7.0 ng digoxin/ml. The accuracy was established by determining the mean recovery (96 percen) of spiked serum samples (0.0--6.0 ng digoxin/ml). The cross reactivity of structure related compounds: digitoxin, spironolactone (Aldactone) and prednisone were investigated. Amniotic fluid, umbilical cord serum and serum of pregnant patients were examined for false positive reaction. Serum samples of 111 patients from two hospitals, who were treated with digoxin, were analysed by EMIT and 3H-radioimmunoassay (RIA); 38 of these samples were also determined by 125I-RIA. A good correlation was found between EMIT assay and these techniques (r =0.90 and 0.91, respectively).

Animals↗
PubMed1975

Paraquat poisoning in man.

In three cases of intoxication by Gramoxone¿, the concentration of paraquat dichloride in blood, dialysate, feces, and urine was determined spectrophotometrically after a clean-up of the biological material by means of ion exchange chromatography (with Dowex 50W-X12 or Zeo-Karb 225). Although good results were obtained after clean-up with Dowex 50W-X12, Zeo-Karb was preferred as ion exchange resin, especially when large sample volumes were needed for the determination. The reported findings indicate that: only 5 to 10% of an ingested dose of paraquat dichloride is absorbed in man, Fullers' earth is very useful, and that primary, e.g. immediate, hemodialysis is necessary.

Adult↗
PubMedDate not supplied

Epidural morphine anesthesia for abdominal aortic surgery--pharmacokinetics.

Plasma and CSF pharmacokinetics of morphine given epidurally in combination with general anesthesia for abdominal aortic surgery were recorded. The initial plasma and CSF concentrations of morphine appeared at two minutes. The peak plasma concentrations of morphine were recorded at 8.0 +/- 2.6 minutes after epidural injection. Plasma mean residence time was 84 +/- 25.7 minutes, Vdss 121 +/- 30 L, and C1 1.5 +/- 0.32 L/min. Free morphine was not detected in plasma 360 minutes after epidural administration. The fraction of the epidural morphine that crossed the dura was 3.15% +/- 2.4 The peak CSF morphine concentrations were recorded at 56 +/- 31 minute. MRT (200 +/- 28 minute), Vdss (65 +/- 33.8 ml), and CL (0.32 +/- 0.15 ml/min) showed that variable fractions of morphine remained many hours in the CSF. Factors that could produce the interindividual variability of plasma and CSF concentrations and pharmacokinetics of epidural morphine were discussed. Abdominal aortic surgery appears to influence both plasma and CSF pharmacokinetics.

Adult↗