Levent Karaca

An enzymeimmunoassay for total thyroxine using avidin-biotin separation system and thyroxine-peroxidase conjugate.

An avidin-biotin enzymeimmunoassay for total thyroxine in serum is described. Avidin was adsorbed to biotinylated bovine serum albumin coated tubes prepared with glutaraldehyde as coupling agent. In the enzymeimmunoassay, affinity purified biotinylated anti-thyroxine IgG, sample or standards, and thyroxine-horseradish peroxidase were simultaneously added to the avidin coated tubes. The bound enzymatic activity was then measured with o-phenylenediamine and H2O2. Results showed that the assay has good precision (within-assay CV% less than 10% and between assay 11.7% in hypo- and 6.9% in hyperthyroid range), good assay range (0-800 nmol/L), good sensitivity (4 nmol/L), and can be performed in 2.5 hours. The results obtained correlate well (r = 0.93) with those of an RIA.

The Development and Validation of a Competitive, Microtiter Plate Enzymeimmunoassay for Human Albumin in Urine

We have described a fast, simple and sensitive microtiter scale, solid phase, competitive enzymeimmunoassay (EIA) for the determination of urinary albumin. The albumin used in the test system was purified by the combination of PEG precipitation and DEAE-cellulose column chromatography. In this EIA, microtiter plates were coated with rabbit antihuman albumin IgG, and incubated with HRP-albumin conjugate with either sample or standards. O-phenylenediamine (OPD) and H2O2 solution was used as substrate for HRP. Results obtained correlate well (r = 0.994) with those of an in-house RIA in which same antibody and standards were used as in EIA. The present assay covers the range of 0.5 to 10 mg/L and can be performed in 2 hours. The detection limit was 0.15 mg/L of albumin. Within-assay coefficient of variation was 8.1% and 6.6% and between-assay variation was 10.6% and 8.6% at 1.25 and 2.5 mg/L respectively.

Paraneoplastic cerebellar degeneration associated with multiple myeloma--3.4 years follow up.

SummaryA 57 year old female patient demonstrated subacute generalized cerebellar symptoms and the investigations which were done exhibited that the clinical picture was due to the remote effect of multiple myeloma. In this case of paraneoplastic cerebellar degeneration, MRI showed cerebellar vermian atrophy when the brain CT scan was negative.Diagnosis of multiple myeloma was possible only on about the 17th month of the illness when monoclonal gammapathy-IgG in serum of the patient and abnormal plasma cells of 13% in her bone marrow biopsy were exhibited. Bence-Jones proteinuria with kappa light chain was found in the 3.4th year of the illness. Paraneoplastic cerebellar degeneration disabled the patient in 3-4 months and remained as an irreversible process during the 3.4 years in which she was followed until her death. Chemotherapy for multiple myeloma did not affect the cerebellar syndrome.