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Biomedical subjects

C Franzelius

Publications and source records attributed to C Franzelius.

6 recordsLinked to original sources
PubMed1998

Simultaneous extraction of selected benzodiazepines and benzodiazepine-glucuronides from urine by immunoadsorption.

A rapid and selective cleanup procedure based on immunoadsorption is described for the simultaneous extraction of diazepam and its free or glucuronidated metabolites nordiazepam, temazepam, and oxazepam from urine. The method can also be used for the extraction of lorazepam and lorazepam-glucuronide. Because the samples do not have to be hydrolyzed before extraction, valuable information is preserved. With the exception of lorazepam-glucuronide, recoveries between 86 and 100% were obtained at spiking levels up to 200 ng of benzodiazepine or glucuronide per milliliter of urine. Using methanol/water (90:10, v/v) as an eluent, the immunoadsorber could be used at least 20 times. High-performance liquid chromatograms of urine samples from patients receiving low therapeutic dosages of diazepam or lorazepam are shown to demonstrate the high purity of the extracts.

Anti-Anxiety Agents↗
PubMed1997

Simple high-performance liquid chromatographic column-switching technique for the on-line immunoaffinity extraction and analysis of flunitrazepam and its main metabolites in urine.

A sensitive, simple and rapid method without sample pretreatment is presented for the simultaneous determination of flunitrazepam and its main metabolites (norflunitrazepam, 7-amino- and 7-acetamidoflunitrazepam) in urine. The single-step procedure is based on a column-switching technique which uses an immobilized antibody in an extraction column following concentration on a precolumn and separation on an analytical column. UV detection was performed at 254 nm. The reusability of the antibody exceeds 88 runs and a complete analysis was performed in less than 40 min. The method shows coefficients of variation below 9.9% and rates of recovery greater than 92% tested at the level of 50 ng/ml urine. The limit of detection was below 2 ng/ml urine for the four compounds.

Anti-Anxiety Agents↗
PubMed1993

Identification and quantitation of intact diastereoisomeric benzodiazepine glucuronides in biological samples by high-performance liquid chromatography.

A rapid and simple high-performance liquid chromatographic method for the simultaneous detection of intact glucuronides of different benzodiazepines is described. Separation of the diastereomers of the following benzodiazepine glucuronides can be achieved on a reversed-phase column (octadecyl or select B): oxazepam, nordiazepam, temazepam, lorazepam and 3-hydroxyprazepam. If the sample contains both S-lorazepam and R-temazepam glucuronides, or both S-temazepam and nordiazepam glucuronides, further separation on a beta-cyclodextrin column is required. The detection limit ranges between 5 and 10 ng of glucuronides per ml of plasma or urine, respectively.

Benzodiazepines↗
PubMedDate not supplied

On-line immunoaffinity extraction and HPLC analysis of flunitrazepam and its main metabolites in serum.

A sensitive, simple, and rapid method for the determination of flunitrazepam and its major metabolites (7-aminoflunitrazepam, 7-acetamidoflunitrazepam, and norflunitrazepam) in serum and plasma is presented. The on-line procedure uses an immobilized, highly reusable antibody against benzodiazepines for selective extraction from serum followed by analysis by high-performance liquid chromatography with ultraviolet detection. This reliable method provides a limit of detection of 1 ng/mL serum, and results are obtained in less than 40 min.

Chromatography, Affinity↗
PubMedDate not supplied

Interaction of testosterone and testosterone receptor complexes with nuclei of skeletal muscle from intact male mice and from mice bearing the testicular feminization (Tfm) mutant gene.

With the nuclear exchange assay and the nuclear retention assay it is shown that the androgen insensitivity of Tfm mice is probably due to a defect of the nuclear acceptor sites for the testosterone receptor complex. Further on the results obtained point strongly to the possibility that hormone free androgen receptor is localized in the nuclei and in the cytoplasma according to the "equilibrium model". A practicable method for separation of unbound steroids from nuclei is described.

Androgen-Insensitivity Syndrome↗