[A new medical concept: the metallic profile]. / Le profil métallique : un nouveau concept médical.

Over the past decade great progress has been made in metals and metalloids analysis. This analysis is a basic stage in toxicity assessment and is indispensable in achieving a realistic evaluation of substance toxicity. A recently introduced technique, inductively coupled plasma mass spectrometry (ICP-MS) is progressively replacing atomic absorption. This analysis permits multi-elementary determinations, approximately 30 elements, with an optimal gain in sensitivity in many biological matrices: i.e. whole blood, plasma, urine, hair, nail, biopsy samples. Moreover, this method allows semiquantitative determination with an additional 30 supplementary elements, which enables the toxicologist to sufficiently estimate the toxic levels and metal exposure. The authors demonstrate that the ICP-MS could be very useful for a wide range of clinical applications. Furthermore, this procedure offers new exploration possibilities in various fields such as clinical toxicology, forensic toxicology as well as work place testing or environmental exposure and permits epidemiologic studies. This analytical method in fact also provides a new scientific approach. To our knowledge we are the first to propose: the metallic profile.

Application of inductively coupled plasma mass spectrometry multielement analysis in fingernail and toenail as a biomarker of metal exposure.

The application of inductively coupled plasma mass spectrometry (ICP-MS) to multielement analysis in fingernail and toenail as biological indices for metal exposure is presented. The ICP-MS measurements were performed using a Thermo Elemental X7CCT series. Fingernail specimens were obtained from 130 healthy volunteers, and paired fingernail and toenail samples from 50 additional healthy volunteers of both sexes were collected as well. After warm water and acetone decontamination, 20 mg fingernails and toenails were acid mineralized after a decontamination procedure, and 32-34 elements were simultaneously quantified after acid dilution following water calibration. Li, Be, B, Al, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Mo, Pd, Ag, Cd, Sn, Sb, Te, Ba, La, Gd, W, Pt, Hg, Tl, Pb, Bi, and U could be validated in fingernail and toenail samples. Linearity was excellent, and the correlation coefficients were above 0.999. Quantification limits ranged from 0.04 pg/mg or ng/g (U) to 0.1 ng/mg or microg/g (B). Because of the lack of available certified nail reference material, an adequate quality assessment scheme was ensured by comparison with an interlaboratory nail-testing procedure, and the results showed optimal consistency for elements tested. Results are presented and compared with published multielement data. Six cases of domestic exposure to lead were diagnosed based on fingernail analysis. Application of ICP-MS multielement analysis in fingernail and toenail as a biomarker of metal and nonmetal exposure permits greater noninvasive control of industrial, domestic, or environmental exposure and is very useful for epidemiological studies.

Hair opiates during pain treatment.

Opiates are commonly used for pain treatment, especially for sharp pain like carcinoma pain. Two opiates are generally prescribed in our hospital: morphine and codeine in association with paracetamol. Most of the patients were given oral forms. Incorporation of morphine and codeine in hair of these patients was studied. Opiates testing in hair is performed by gas chromatography-mass spectrometry (GC-MS), using acid hydrolysis in presence of deuterated standards, a three-step liquid extraction and derivatization with BSTFA + TMCS. Results of codeine and morphine content in hair during pain treatment showed no correlation group between dose and concentration of the drug in hair. However, codeine values in hair during pain treatment compared to codeine in the hair of codeine abusers was significantly different (P < 0.0001).

Phenobarbital in hair and drug monitoring.

Phenobarbital analysis was performed in vertex hair of patients by gas chromatography mass spectrometry (GC/MS). After washing with dichloromethane, about 250 mg were ground to dust in a ball mill. A 50-mg sample was stirred mechanically for 10 min with 3 ml of NH4Cl/HCl buffer (pH 2.0) containing phenobarbital D5. A solid phase extraction was performed (extrelut Merck) and elution was achieved with chloroform/isopropanol/n-heptane (50:17:33; v/v). A full scan (40-240 uma) acquisition was realized by GC/MS with an ion trap (ITD 700 Finnigan) using a DB5-MS chromatographic column. Quantification was achieved by integrating dominants ions (phenobarbital, 204; phenobarbital D5, 209). Compared to serum, hair concentrates phenobarbital during anti-epileptic therapy (average value 36.4 ng/mg, n = 40 vs. 18.7 mg/l, n = 23). A group correlation exists between phenobarbital in hair and phenobarbital in serum, and between phenobarbital in hair and clinic observation in some typical cases. Phenobarbital in hair yields good information over a long period, especially when blood collection has not been made, when clinical disorders are observed on long-term therapeutic observance.

[Does the insulin-secretion capacity of non-diabetic subjects possess a prognostic value? (author's transl)]. / La capacité d'insulino-sécrétion des sujets non diabétiques possède-t-elle une valeur pronostique?

Twenty-two patients, whose initial oral glucose tolerance test (OGTT) was not diabetic, but who possibly had predisposition for diabetes, underwent iterative OGTT with plasma insulin determination and estimate of insulin-secretion capacity (plasma insulin area/blood glucose area ratio, and insulin-secretion coefficient). With a 30 months mean time interval between the two tests, a highly significant negative correlation was found between insulin-secretion capacity of the first test and blood glucose area of the last one. Glycemic curve of the OGTT was diabetic in 3 cases at the final test. Thus, it seems possible to select subjects most prone to future diabetes with simple parameters estimating insulin-secretion capacity during OGTT.