[Guidelines for results reports of biological examinations]. / Recommandations concernant la transmission des résultats d'examens de biologie médicale.

This article presents recommendations for results reports after release by authorized person to fulfill the French regulation and ISO 15189 requirements. This document points out who can be authorized to communicate the reports and to whom. The advantages and disadvantages of the different ways to use for results report are discussed, as traceability and confidentiality rules to apply. Particular situations as critical values to report and correction of transmitted erroneous results. A table summarizes the different modalities available to communicate the results of examinations performed by the laboratory.

[VIDAS Stallertest: clinico-biological evaluation of a new global test for respiratory allergy]. / VIDAS Stallertest évaluation clinico-biologique d'un nouveau test global pour l'allergie respiratoire.

"VIDAS Stallertest" is a new screening test for breathing allergy. It allows the detection of 10 different lung specific allergens including domestic acarids (D1), pollents (G3, W6, W21, T3 and T9), pets dander (E1 and E2), moulds (M6), cockroach (16). The method is an immunoenzymatic reaction that contains a cartridge and a cone that is cover with the allergen's mixture and is automated on the VIDAS system. The results are compared to various skin tests analyzed by instantaneous reading for 102 patients. "VIDAS Stallertest" shows an excellent agreement (93%) with the allergic patients as well as with those that are not. The specificity of the new screening test is very high (91%). A comparative study between "VIDAS Stallertest" and "Phadiatop" performed on 155 consultants in allergist office shows a correlation of 93%, a sensitivity and a specificity of 91 and 95%, respectively. "VIDAS Stallertest" is a reliable method in first intention for the general practitioner who faces a putative breathing allergy. Moreover, this is an excellent biological check-up for a questionable or negative skin test.

Low-density lipoprotein ability to generate lipoperoxides in healthy subjects: variations according to age.

Oxidized low-density lipoproteins (LDLs) are recognized to be involved in atherosclerosis development. Since the plasma oxidized LDL assay is inadequate because of the short half-lives of LDLs, measurement of the in vitro ability of LDLs to generate lipoperoxides (LDL-GLs) has been preferred. The present study displays a profile of LDL-GLs in a group of 175 healthy subjects, using a method to measure thiobarbituric acid-reactive substances. We have observed an increased LDL-GL level according to age.

Alcoholic cirrhosis and cobalamin metabolism.

The cobalamin status of 27 patients suffering from alcoholic cirrhosis and 20 control subjects was analyzed. Plasma cobalamin (p < 0.005), total corrinoids (p < 0.005) and their analogs (p < 0.05) were all significantly elevated in the cirrhosis patients. These differences were due to increased haptocorrin (HC)-bound corrinoid (p < 0.02), which could be explained by a deficient hepatic clearance of cobalamin bound to HC. The increase in the concentration of true cobalamin was greater than that of its analogs. There were positive correlations between cholestasis (serum alkaline phosphatase) and plasma analog concentrations (p < 0.05), HC-bound cobalamin (p < 0.005) and total corrinoids bound to HC (p < 0.005). The plasma concentrations of the indicators of cobalamin deficiency, homocysteine (p < 0.05) and methylmalonic acid (p < 0.001), were increased, which could indicate poor cellular penetration of vitamin B12 or a defect in the activation of the two vitamin-B12-dependent enzymes.

Crohn's disease and vitamin B12 metabolism.

The concentrations of vitamin B12, its analogs, and the haptocorrin and transcobalamin carriers in 21 patients suffering from Crohn's disease and a group of controls (20 adults) were measured. There were no significant differences in the mean values for vitamin B12, total corrinoids (vitamin B12 + analogs), or vitamin B12 or total corrinoids bound to haptocorrin or transcobalamin of the Crohn's and control patients. There was a significant increase in the binding capacity of transcobalamin in the Crohn's patients compared to the controls (P < 0.001), but there was no difference in the binding capacities of haptocorrin. The serum concentrations of the markers of vitamin B12 status, homocysteine and methylmalonic acid, showed an increase (P < 0.01) in homocysteine in the Crohn's disease patients, but no change in methylmalonic acid. As the hyperhomocysteinemia was associated with normal folate concentrations, there may have been a defect in the activation of the enzyme due to altered intracellular vitamin B12 status.

Dietary calcium salts as protective agents and laminin P1 as a biochemical marker in chemically induced colon carcinogenesis in rats.

To evaluate the protective effect of different calcium forms against colon carcinogenesis, Wistar rats fed a high-fat diet (24%) were supplemented with different chemical forms of dietary calcium and were intrarectally instilled with N-methyl-N-nitrosourea (NMU). Supplemental calcium was administered at 1.5% mineral (w/w of total diet) complexed with either carbonate, gluconate, or lactate in Groups 2, 3, and 4, respectively. The tumor incidence of colon cancer was compared with a control group (Group 1), fed the same diet without supplemental calcium. Colon carcinoma incidence was 31, 33, 13, and 7% in Groups 1, 2, 3, and 4, respectively. Calcium had a significant protective effect against carcinogenesis, and the maximum protective effect was observed with gluconate and lactate forms. Laminin P1 blood level was measured as a tumor marker. Laminin P1 results were compared with the reference group (Group T), fed a standard diet and not NMU instilled. The serum laminin P1 level was significantly higher (p = 0.0001) in NMU-instilled Groups 1, 2, 3, and 4 (0.24 +/- 0.03, 0.93 +/- 1.43, 0.84 +/- 1.33, and 0.41 +/- 0.34 mU/ml respectively) than in the Reference Group T (0.10 +/- 0.05 mU/ml).

Spermatogenic cells do internalize Sertoli androgen-binding protein: a transmission electron microscopy autoradiographic study in the rat.

Specific binding sites for androgen-binding protein (ABP) have been demonstrated recently to be present on germ cells from the rat and on membrane-enriched fractions from rat germ cells. The present study was undertaken to test if such receptors could lead to the activation of a specific internalization pathway as in other cells. Isolated rat germ cells and in situ rat germ cells, maintained within the seminiferous epithelium with either an intact or a bypassed blood testis barrier, were exposed to culture medium containing 12,000 cpm/ml [3H] delta 6-testosterone (2.5 pg) photoaffinity-labeled ABP, purified from rat testis. The follow-up of labeled ABP/germ cell interactions was based on qualitative and quantitative transmission electron microscopy autohistoradiography. Attention was focused on adluminal germ cells from pachytene spermatocytes to mature spermatids, which are normally present above the Sertoli cell tight junctions. Our observations revealed the presence in rat germ cells of structures related to specific endocytosis, namely coated pits and vesicles which stained positively with anticlathrin antibodies. When exposed to the [3H] delta 6-testosterone-ABP complex, adluminal germ cells showed marked labeling of these endocytic organelles. Preincubation either with excess unlabeled ABP or pretreatment by EDTA reduced the labeling significantly. Once internalized, ABP was found to be confined to the endocytic and nuclear compartments. The nuclear labeling was high in primary spermatocytes and round spermatids but was absent in elongated spermatids with condensed chromatin, in which transcriptional activity had almost stopped. In contrast, at later steps of spermiogenesis, the cytoplasm became heavily labeled, especially in the postnuclear part of elongated spermatids and in residual bodies about to be phagocytozed by Sertoli cells. Experiments using ligated seminiferous tubules, with an intact blood-testis barrier, clearly showed that ABP was captured at the basal part of Sertoli cells, transported up to the adluminal compartment and delivered to germ cells which finally internalized the protein. Experiments using largely opened seminiferous tubules allowing ABP to bypass the blood-testis barrier led to a delay in adluminal germ cell labeling compared with that in isolated germ cells. In all experiments in which germ cells were incubated in teh presence of Sertoli cells, the labeling observed at the surface of the germ cell line, especially over coated pits, was mostly found facing thin Sertoli cell processes, suggesting the possible existence of a specific mechanism for the presentation of ABP by the Sertoli cells to adluminal germ cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Quantification of methylmalonic acid in serum measured by capillary gas chromatography-mass spectrometry as tert.-butyldimethylsilyl derivatives.

Quantification of methylmalonic acid in serum is considered one of the most sensitive parameters for diagnosis of cobalamin deficiency. Methylmalonic acid was measured as tert.-butyldimethylsilyl derivatives formed in the presence of dimethylformamide. Under these conditions the derivative was quantified using gas chromatography-mass spectrometry with selected-ion monitoring at 403 and 406 for methylmalonic acid and methyl-d3-malonic acid, respectively. The characteristics of the method were: linearity from 0.04 to 1.7 mumol/l with linear regression equation y = -0.0199 + 0.727 x (r = 0.999); recovery 95.5 +/- 6.8%; detection threshold 17 fmol injected; within-day variation coefficient ranging from 3.10% to 5.6% according to sample concentration; and day-to-day coefficient of variation of 6.8% and 5.3% for methylmalonic acid concentrations of 0.103 mumol/l and 0.360 mumol/l, respectively. The normal range after log transformation was estimated at 0.03-0.26 mumol/l, 0.06-0.33 mumol/l and 0.02-0.40 mumol/l in children of 4-14 years (n = 39), in healthy subjects at 20-40 years (n = 70) and in healthy elderly persons older than 60 years (n = 14), respectively. The normal range in children was significantly lower than that in adults and, in contrast, normal values in the elderly were significantly higher.

Free fatty acid-induced alterations in the steroid-binding properties of rat androgen-binding protein.

The free fatty acid (FFA) concentration in the epididymal cytosol of the adult rat was found to be 20-fold higher than in the serum. The binding of [3H] dihydrotestosterone to epididymal rat androgen binding protein (rABP) was modified by physiological concentrations of saturated and unsaturated fatty acids. Polyunsaturated fatty acids inhibited the binding more efficiently than monounsaturated or saturated fatty acids. Scatchard analysis and Dixon plots indicated that the number of binding sites decreased in presence of unsaturated fatty acids with an inhibition constant (Ki) of 4 microM for arachidonic acid (C20:4) and 20 microM for oleic acid (C18:1). These results indicate that unsaturated fatty acids induce alterations in rABP steroid-binding properties that could modulate the endocrine function of rABP.

Transcobalamin II--cobalamin binding sites are present on rabbit germ cells.

Specific binding sites for rabbit transcobalamin II have been found on isolated adult rabbit germ cells. Scatchard analysis revealed a single class of binding sites for [57Co]cyanocobalamin-transcobalamin II with an association constant (Ka) of 1.3 x 10(10) M-1 and 700 sites per cell. Binding was reversible, saturable and calcium dependent. Electron microscope radioautography following incubation with iodinated transcobalamin II at 4 degrees C led to a detectable labeling mainly restricted to the plasma membrane.

Photoaffinity labelled rat androgen-binding protein and human sex hormone steroid-binding protein bind specifically to rat germ cells.

A specific receptor with high affinity for rat androgen-binding protein (rABP) was identified in isolated adult rat germ cells and in the corresponding plasma membrane-enriched preparations. Binding was reversible and time-dependent, with maximum relative binding after 40 min at 4 degrees C; it was pH-dependent, with maximum binding at pH 6-8. Unlabelled rABP and human sex steroid-binding protein (hSBP), but not lactotransferrin, serotransferrin, asialofetuin, fetuin or bovine serum albumin, competed with labelled rABP for binding sites on isolated germ cells. Scatchard analysis revealed a single class of binding site with apparent dissociation constant (Kd) values of 0.78 +/- 0.04 nM and 0.97 +/- 0.05 nM in intact germ cells and plasma membrane preparations respectively. A Kd of 1.72 +/- 0.12 nM for hSBP showed that the receptor binding site was effective for both androgen-carrier molecules. Labelled rABP incubated with solubilized germ cell membrane fractions at pH 7 formed a complex excluded from Superose 6B mini-gels; this complex was not formed at pH 3. The receptor complex was also abolished in the presence of a 100-fold excess of either unlabelled rABP or unlabelled hSBP, or in the presence of 20 mM EDTA. These results suggest that the plasma membrane of rat germ cells contains a receptor which selectively binds rABP and hSBP.

The plasma membrane of epididymal epithelial cells has a specific receptor which binds to androgen-binding protein and sex steroid-binding protein.

The binding of [3H] delta 6-testosterone photoaffinity-labelled rat androgen-binding protein (rABP) has been studied in an enriched fraction of plasma membranes of epithelial epididymal cells in immature (15 days) and adult rats (40 days). The binding was maximal in less than 30 min and more rapid at 4 degrees C than at 34 degrees C. It was calcium and pH dependent. Scatchard plots of the binding data gave curvilinear plots with two types of binding sites corresponding to a K(ass1) of 18.2 nM-1 and K(ass2) of 1.6 nM-1 (2.2 x 10(11) sites/mg protein and 5.4 x 10(11) sites/mg protein, respectively). In adult rats, only one type of binding site was found, with a K(ass) of 3.7 nM-1 (4.5 x 10(11) sites/mg protein). The number of receptors was 5-fold lower in the cauda than in the caput of the epididymis. The pretreatment of the isolated intact cells with streptozotocin induced a 45% reduction of the binding. Only unlabelled rABP and hSBP (human sex steroid-binding protein) but not other proteins (lactotransferrin, serotransferrin, asialofetuine, fetuine and bovine serum albumin) competed with the labelled ligand to bind plasma membranes. The membrane fraction was solubilized by triton X-100. Its incubation with labelled rABP and hSBP provoked the elution of the tracer as an aggregate into the void volume fraction of superose 6B mini-gel filtration columns. Structural homology between hSBP and rABP could be responsible for the common behaviour of the steroid-carrier molecules for the ABP receptor of rat epididymal epithelial cells.

Evidence that androgen-binding protein endocytosis in vitro is receptor mediated in principal cells of the rat epididymis.

We have studied the binding of [125I-iodo]androgen-binding protein (ABP) and of [3H]delta 6-testosterone photoaffinity-labelled ABP to receptors in the plasma membrane of rat epididymal cells in three ways: ABP binding to a Triton X-100-solubilized membrane extract, ABP binding to isolated epithelial cells in suspension and autoradiography of segments of dissected epididymides after in-vitro intraluminal injection of labelled ABP. The binding of iodinated ABP to the receptor was similar to that of photoaffinity-labelled ABP in gel filtration. The ABP-receptor complex was eluted from Superose 6 gels as an aggregate, with a molecular mass of 2000 kDa. It was separated into two peaks by sucrose gradient ultracentrifugation, with respective sedimentation coefficients of 18.4 and 9.0 s. The activity of the receptor (ABP-binding capacity/mg protein) was tenfold higher in the caput than in the cauda. The binding of ABP to the receptor was pH dependent, being almost abolished at pH less than 4. The binding at 4 degrees C of photoaffinity-labelled ABP to epithelial cells corresponded to two types of binding sites. The numbers of high-affinity and low-affinity sites per cell were 1600 and 7700 respectively; the association constants of these sites were 67.9 and 2.8 litres/nM respectively. The binding was decreased by treatment of the cells with trypsin or incubation in the presence of EDTA. The binding in vitro of labelled ABP to the epididymis epithelium reached a maximum after about 20 min at 4 degrees C. In the autoradiographic study the tracer was found to be closely associated with coated pits, coated vesicles, endosomes and pale multivesicular bodies. Treatment of rats with cycloheximide significantly reduced the uptake of the tracer. Perfusion in vitro of epididymides with chloroquine produced a fourfold increase of the tracer in endosomes and multivesicular bodies.

Blood transcobalamin levels in malignant hepatoma.

Alpha-Fetoprotein (AFP) levels measured by RIA show a strong sensitivity for the biological diagnosis of malignant hepatoma (MH). However, this parameter lacks specificity. Previous observations of an alteration in vitamin B12 metabolism in the presence of hepatoma led us to study vitamin-B12-binding proteins. Vitamin B12, also called cobalamin, is transported in the blood by two proteins or transcobalamins: one is haptocorrin (HC), which is linked to most of the cobalamin, and the other is transcobalamin II, which is involved in tissue exchanges. In this work, the levels of AFP and transcobalamins were determined by RIA and radioisotope dilution assay, respectively. They were measured in patients with MH (group A) and in patients with other liver diseases (group B). Compared with group B, group A showed a significant increase in total serum HC (p less than 0.005). In conclusion, it was observed that MH is accompanied by increased levels of HC. The origin of these changes could be due to either an increase in HC synthesis or a catabolic defect.