[Evaluation of treatment relating to gestational trophoblastic tumor registered to the French Trophoblastic Disease Reference Center (TDRC) in Lyon from 1999 to 2005]. / Evaluation de la prise en charge des tumeurs trophoblastiques gestationnelles enregistrées au Centre de référence des maladies trophoblastiques de Lyon de 1999 à 2005.

OBJECTIVES: The aim of this study was both to analyse if gestational trophoblastic neoplasia (GTN) registered to the French Trophoblastic Disease Reference Center (TDRC) in Lyon (France) were managed according to the FIGO criteria for diagnosis of GTN and if chemotherapy was adapted to the 2000 FIGO prognostic scoring system. PATIENTS AND METHODS: Retrospective, descriptive analysis of 167 GTN registered to GTC of Lyon between 1999 and 2005. RESULTS: On the one hand, 66% of women (104/158) had a diagnosis of GTN according to FIGO criteria. One third (n=54) of the patients therefore had a premature or erroneous diagnosis of a tumor, when the treatment started. No supporting element of this premature diagnosis has been found out for 26 patients. The identification of lung and vaginal metastasis and histological diagnosis of invasive mole appeared as the most mentioned inappropriate criteria for diagnosis. On the other hand, chemotherapy was adapted to 2000 FIGO scoring in 91, 5% of cases. Twelve low risk GTN were treated with polychemotherapy and two high risk GTN were treated with monochemotherapy. Moreover 29% of the patients received a non adequate treatment due to deviations from the recommended protocol. DISCUSSION AND CONCLUSION: Non respect of FIGO criteria for the diagnosis of GTN can lead to erroneous diagnosis of tumors. Identification of lung or vaginal metastasis or diagnosis of invasive mole should not automatically justify the diagnosis of gestational trophoblastic neoplasia if the decrease in HCG occurs properly. Respect of FIGO criteria for the diagnosis of GTN and adaptation of chemotherapy to 2000 FIGO scoring are necessary to avoid inadequate treatment of gestational trophoblastic neoplasia.

Comparison of progesterone concentration determination by 12 non-isotopic immunoassays and gas chromatography/mass spectrometry in 99 human serum samples.

A single serum progesterone determination may be highly predictive for early pregnancy and in vitro fertilisation and embryo-transfer outcomes. We therefore compared 12 direct non-isotopic progesterone immunoassays with gas-chromatography/mass spectrometry (GC/MS). For each assay, data from the analysis of 99 individual sera were compared with data obtained by GC/MS, using regression and bias plot analyses and the ratio method. We observed a larger difference in concentration between high and low values and a broader distribution of results for immunoassays than for GC/MS. All immunoassays displayed bias in the calibration process and a lack of specificity and/or sensitivity, to various degrees. We tried to identify the parameters of the assay procedure that might contribute to these discrepancies. None of the criteria investigated (antibodies, control and preparation of calibrators, blocking agents and choice of tracer) had a significant effect when studied alone.

Determination of plasma methoxyamines.

The determination of plasma methoxyamines is the most informative parameter for the diagnosis of pheochromocytoma. Very good sensitivity and specificity are necessary for this. The measurement of deconjugated (free plus sulfate-conjugated) metanephrines is more useful. Concentrations are 10-fold higher than free metanephrine concentrations. The methodology generally uses a column purification and high performance liquid chromatography with electrochemical detection. We have tested six commercial columns used for the purification step. We chose a rapid and reliable method with a mixture of strong cation-exchange and strong anion-exchange groups bonded onto a silica column. This protocol has been validated with samples of plasma from normal subjects, healthy elderly people, renal failure patients and patients with pheochromocytoma.

[Validity of immunochemical methods for bloody progesterone: a study performed in 1998]. / Validité des dosages immunochimiques de la progestérone dans le sang: étude réalisée en 1998.

The aim of this study was to compare, with manufacturer's agreement, twelve direct and non-isotopic commercial assays of progesterone. We have evaluated the analytical performances: low limit detection, imprecision, accuracy (recovery and dilution tests) and we have tested some patient samples. Results were compared to a reference method using isotope dilution Gas Chromatography and Mass Spectrometry combination (GC-MS). For each assay, analytical qualities and defaults are established. Large differences are found between progesterone concentration measured on the same sample with the different methods essentially for the low concentrations. Comparison with GC-MS raised questions about the accuracy of the different assays. This work will be aid laboratories to their choice and/or validation.

[Validity of immunochemical assays for blood estradiol. Study conducted in 1994]. / Validité des dosages immunochimiques de l'estradiol sanguin. Etude réalisée en 1994.

Since 1989 many kits have been commercialized for measuring estradiol by non-isotopic immunoassays which largely contributed to the diffusion of this parameter. Rapidly, in quality control schemes, a wide dispersion of results has been observed. In this paper, the kits' characteristics (precision, accuracy and detection limit) have been studied and compared to a reference method (gas chromatography-mass spectrometry). In addition, estradiol determinations in patients with various pathophysiological situations have been performed to underline the difficulties of interpretation of this analyte when clinicians compare results given by the different kits. This work demonstrates that precision and accuracy varied both with the kit and the level of concentration of estradiol and gives better results for high concentrations of estradiol. In seven out of the 12 kits, the limits of detection are in good agreement with those announced by manufacturers. On the contrary, the determination on patients sera gives results with a high variability with no systematic error.

Specific assay for unconjugated dehydroepiandrosterone in human plasma by capillary gas chromatography with electron-capture detection.

A specific and sensitive method for the determination of unconjugated dehydroepiandrosterone in plasma is described. After extraction and purification of the extracts on a Celite column, the iodomethyldimethylsilyl ether derivative of dehydroepiandrosterone was isolated on an aluminium oxide column and assayed by gas chromatography with electron-capture detection. The method is sensitive: sample volumes of 0.5-1 ml are sufficient for the determination of dehydroepiandrosterone in plasma of normal male and female subjects aged 1-80 years. The assay is highly specific and has the potential to be used as a reference method for the determination of unconjugated dehydroepiandrosterone in biological samples.

[Urinary elimination of urinary tetrahydroaldosterone measured by gas-phase chromatography. Normal values in adults]. / Elimination urinaire de la tétrahydroaldostérone urinaire par chromatographie en phase gazeuse. Valeurs usuelles chez l'adulte.

The authors describe a method of titration of tetrahydroaldosterone in the urine, requiring an internal non-radioactive standard. This method uses high performance liquid chromatography as a mean of isolating tetrahydroaldosterone (THAldo) and chromatography in gaseous phase as a method of titration in the form of heptafluorobutyrate after oxidation into gamma lactone. It permits to detect 3 ng of gamma lactone of THAldo corresponding to a urinary concentration of 16 nmol/l.

Determination of urinary estradiol using an enzymatic method during the menstrual cycle. Comparison with an method using isotope dilution-mass spectrometry (ID-MS).

Results for measurements of urinary estradiol were compared with results from a method using isotope dilution-mass fragmentography. Urine samples were collected from women during the menstrual cycle. The results obtained differed in absolute values, but showed good correlation.

[Assay of plasma dehydroepiandrosterone sulfate by gas chromatography with electron-capture detection]. / Dosage du sulfate de déhydro-épiandrostérone plasmatique par chromatographie en phase gazeuse avec détection par capture d'électrons.

A sensitive and specific method for the determination of plasma S-DHA by gas chromatography (GC), with fused silica capillary column (stationary phase SE 54) and electron capture, after solvolysis of the sample and purification by high performance liquid chromatography (HPLC) is described. The interest of the new internal standard (5 alpha androst-9(11)-ene-3 beta ol-17-one) for the determination of the DHA by GC is shown. The analytical characteristics of this method as well as a comparative study of the values obtained by this method and by radioimmuno-assay are described.

[Assay of 3-methyl histidine in the urine by gas-phase chromatography: significance of the normal values in adults]. / Dosage de la 3-méthyl-histidine urinaire par chromatographie en phase gazeuse: signification des valeurs usuelles chez l'adulte.

The authors present a method for the assay of urinary 3-methyl histidine (3-MH) by gas phase chromatography. The reference values are established in adult men and women during a free diet and during a non-meat diet. The results, expressed in 3-MH/d and 3-MH/creatinine are discussed in relation to sex and to diet.

[Immunological quantity determinations of hPL and total oestrogens during the course of pregnancy (author's transl)]. / Dosages immunoenzymologiques de l'hPL et des oestrogènes totaux au cours de la grossesse.

The quantity determination of hPL and of total plasma oestrogens, by means of immuno-enzymology in the heterogenic phase, allows a satisfactory pregnancy. The methods of quantity determination are presented and studied; the criteria for the quality of these methods, and the values found during the course of normal pregnancy, can allow them to be used in many laboratories.