[Inappropriately undetectable thyroglobulin after exclusion of interference from thyroglobulin antibodies].

Thyroglobuline (Tg) is a large molecule of high molecular weight mainly indicated in monitoring differentiated thyroid cancer (DTC), its measurement remains difficult. We report the case of a patient who underwent total thyroidectomy for a poorly differentiated thyroid insular carcinoma. Despite several (131)I treatments, a progressive elevation of serum Tg is observed.

Lectin affinity electrophoresis of serum alkaline phosphatase in metastasized breast cancer.

The use of serum alkaline phosphatase (ALP) isoenzymes as markers of breast cancer metastases and treatment efficacy has received little attention. Twenty-six breast cancer women (56+/-13 years, all post-menopausal) were prospectively evaluated during their first and third course of chemotherapy (4-week interval). Serum samples were analyzed for ALP isoenzymes (bone, liver, and intestine) using a lectin affinity electrophoresis kit (Hydragel 15 ISO-PAL, Sebia) adapted on a semi-automated Hydrasys system (Sebia).

Clinical value of combined determination of plasma L-DOPA/tyrosine ratio, S100B, MIA and LDH in melanoma.

Aim Of The Study: L-DOPA/tyrosine ratio (an index of tyrosinase activity), melanoma antigens S100B and MIA, lactate deshydrogenase (LDH) and their combinations were evaluated for clinical value as tumour markers in melanoma.

Methods: Blood samples were obtained in 170 melanoma patients (stage I-II: n=57, III: n=54, IV: n=59) at inclusion and in a sub-group of 82 subjects during follow-up for up to 4 years. Laboratory analyses were performed by HPLC (L-DOPA, L-tyrosine), immunoassays (S100B, MIA) and colourimetry (LDH).

Simultaneous determination of monodesethylchloroquine, chloroquine, cycloguanil and proguanil on dried blood spots by reverse-phase liquid chromatography.

A method for simultaneous analysis of chloroquine, proguanil and their metabolites from a whole blood sample (80 microL) dried on a filter paper was developed. Sample preparation included a liquid extraction from the filter paper, followed by a solid-phase extraction (C18 Bond Elut cartridge). Separation was obtained by reverse-phase liquid chromatography (HPLC) using a gradient elution on an X-Terra column; UV detection was made at 254 nm.

Evaluation of renal function in intensive care: plasma cystatin C vs. creatinine and derived glomerular filtration rate estimates.

Plasma cystatin C, a new marker of glomerular filtration rate (GFR), was prospectively evaluated in surgical intensive care. Cystatin C was measured (immunonephelometry, Dade-Behring) in 10 patients selected to cover a full range of GFR (phase I) and in 28 unselected consecutive patients followed for 5 days post-admission (phase II). Results were compared with (51)Cr-EDTA clearance (phase I only), plasma creatinine (kinetic Jaffe, Roche), 24-h or estimated by Cockcroft and Gault (CG) creatinine clearance (CrCl), and modified diet in renal disease (MDRD)-estimated GFR.

Quantification of pralidoxime methylsulfate (Contrathion) in human urine by capillary zone electrophoresis.

Pralidoxime methylsulfate (Contrathion) is widely used to treat organophosphate poisoning. For the first time, we developed a specific assay for urinary pralidoxime using capillary zone electrophoresis (CZE) in the following conditions: fused-silica capillary (length: 47 cm, internal diameter: 75 microm), electrolyte solution: 25 mM sodium borate (pH 9.1), voltage: 15 kV, temperature: 25 degrees C, injection time: 1 or 2s, on-line UV detection: 280 nm.

Cystatin C as a marker of GFR--history, indications, and future research.

Objective: To summarize recent knowledge on the small molecular weight protein cystatin C (cys-C) and its use as a marker of the glomerular filtration rate (GFR).

Methods: A multinational expert meeting was held in April 2002 in Marburg, Germany. Contributors summarized their main findings.

Evaluation of the serum L-dopa/L-tyrosine ratio as a melanoma marker.

A wide range of molecules have been investigated as tumour markers in melanoma, most of which are not suitable for use by clinical oncologists for the detection of fast and unpredictable metastatic dissemination. We have already shown that the serum L-dopa/L-tyrosine ratio (an index of tyrosinase functional activity) correlates with the tumour burden and in some cases predicted disease progression in metastatic melanoma patients. We examined the potential value of this ratio for the follow-up, therapy monitoring and prognosis in melanoma compared with a reference marker (S100B, a melanoma-associated antigen).

Automated multicapillary electrophoresis for analysis of human serum proteins.

Background: We evaluated a new, automated multicapillary zone electrophoresis (CE) instrument (Capillarys), 4.51 software version; Sebia) for human serum protein analysis.

Methods: With the Capillarys beta1-beta2+ reagent set, proteins were separated at 7 kV for 4 min in 15.

Urinary free light chain analysis by the Freelite immunoassay: a preliminary study in multiple myeloma.

Evaluate the Freelite free light chain immunoassay for urine analysis in myeloma. Urine specimens from 20 patients were analyzed by Freelite (The Binding Site) and SDS-agarose gel electrophoresis (Hydragel protéinurie, Sebia). Using the kappa/lambda ratio, Freelite was more sensitive than electrophoresis to detect free light chains, but concentration was overestimated in 75% of cases.

Determination of poorly separated monoclonal serum proteins by capillary zone electrophoresis.

A capillary zone electrophoresis (CZE) technique was developed for the determination of poorly separated monoclonal serum proteins by agarose gel electrophoresis (AGE). A P/ACE 5500 capillary instrument (Beckman) was used under the following conditions: 57 cm x 50 microm I.D.

Chemotherapy inhibits skeletal muscle ubiquitin-proteasome-dependent proteolysis.

Chemotherapy has cachectic effects, but it is unknown whether cytostatic agents alter skeletal muscle proteolysis. We hypothesized that chemotherapy-induced alterations in protein synthesis should result in the increased incidence of abnormal proteins, which in turn should stimulate ubiquitin-proteasome-dependent proteolysis. The effects of the nitrosourea cystemustine were investigated in skeletal muscles from both healthy and colon 26 adenocarcinoma-bearing mice, an appropriate model for testing the impact of cytostatic agents.