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Biased agonism at G protein-coupled receptors constitutes a promising area of research for the identification of new therapeutic molecules. In this study we identified two novel biased ligands for the chemokine receptors CCR2 and CCR5 and characterized their functional properties. We showed that J113863 and its enantiomer UCB35625, initially identified as high affinity antagonists for CCR1 and CCR3, also bind with low affinity to the closely related receptors CCR2 and CCR5. Binding of J113863 and UCB35625 to CCR2 or CCR5 resulted in the full or partial activation of the three Gi proteins and the two Go isoforms. Unlike chemokines, the compounds did not activate G12. Binding of J113863 to CCR2 or CCR5 also induced the recruitment of -arrestin 2, whereas UCB35625 did not. UCB35625 induced the chemotaxis of L1.2 cells expressing CCR2 or CCR5. In contrast, J113863 induced the migration of L1.2-CCR2 cells but antagonized the chemokine-induced migration of L1.2- CCR5 cells. We also showed that replacing the phenylalanine 3.33 in CCR5 TM3 by the corresponding histidine of CCR2 converts J113863 from an antagonist for cell migration and a partial agonist in other assays to a full agonist in all assays. Further analyses indicated that F3.33H substitution strongly increased the activation of G proteins and β-arrestin 2 by J113863. These results highlight the biased nature of the J113863 and UCB35625 that act either as antagonist, partial agonist, or full agonist according to the receptor, the enantiomer, and the signaling pathway investigated., SCOPUS: ar.j, info:eu-repo/semantics/published

May-Grünwald-Giemsa (MGG) stain is a Romanowsky-type, polychromatic stain as those of Giemsa, Leishman and Wright. Apart being the reference method of haematology, it has become a routine stain of diagnostic cytopathology for the study of air-dried preparations (lymph node imprints, centrifuged body fluids and fine needle aspirations). In the context of their actions of promoting the principles of quality assurance in cytopathology, the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP) and the French Society of Clinical Cytology (SFCC) conducted a proficiency test on MGG stain in 2013. Results from the test, together with the review of literature data allow pre-analytical and analytical steps of MGG stain to be updated. Recommendations include rapid air-drying of cell preparations/imprints, fixation using either methanol or May-Grünwald alone for 3-10minutes, two-step staining: 50% May-Grünwald in buffer pH 6.8 v/v for 3-5minutes, followed by 10% buffered Giemsa solution for 10-30minutes, and running water for 1-3minutes. Quality evaluation must be performed on red blood cells (RBCs) and leukocytes, not on tumour cells. Under correct pH conditions, RBCs must appear pink-orange (acidophilic) or buff-coloured, neither green nor blue. Leukocyte cytoplasm must be almost transparent, with clearly delineated granules. However, staining may vary somewhat and testing is recommended for automated methods (slide stainers) which remain the standard for reproducibility. Though MGG stain remains the reference stain, Diff-Quik(®) stain can be used for the rapid evaluation of cell samples.

A rapid counting method has been used to estimate the microbial flora of beef, pork and sheep. The test used in this study permitted a 3 h counting of the bacteria whatever their origin. The easiness of the test makes it feasible for the appreciation of the hygienic conditions existing during the slaughtering operations.

The aflatoxinogenesis of Aspergillus parasiticus is significantly enhanced by the presence, in the medium, of sterigmatocystin at a high level (35--50 microgram/ml); low concentrations, in the order of 175 microgram/ml, have no effect on the production of aflatoxins. During the period where the aflatoxinogenesis of the culture is high, no variation of the sterigmatocystin level is noted, Experiments with 14C-sterigmatocystin indicate that the mold does not utilize the metabolite itself as a precursor of aflatoxins.

It is shown that, when excited in the visible range, fluorescence of the dye may be either quenched or enhanced, from its initial value Fo, by addition of increasing "normal" immunoglobulin (IgGH7 S), depending if the solution is "non-chaotropic " (NaF 0,1 M) or "chaotropic" KI 1 M). Let F be the fluorescence obtained at concentration P in protein, then the plot of the quantity P.F/(FO-F)against the quantity P.F/(FO-F) gives a straight line; the zero ordinate of this is the inverse of the non-specific interaction equilibrium constant. Quenching of fluorescence by increase of temperature, and by increase of concentration of salt (KI) are also quantitatively dealed upon in order to testify that this non-specific interaction is of the "adsorption" type. Concentration of dye is 10-6M; concentration of protein is varied from 0,05 % to 0,5 %.

Aspergillus versicolor is cultivated in a synthetic medium for 22 days. Bioproduction of lipids and sterigmatocystin are compared. The fatty acids of the neutral lipid and polar lipids fractions are mainly: C 16:0, C 18:0, C 18:1, C 18:2, C 18:3. Maximal yields of dry weight, neutral lipids and sterigmatocystin occur, respectively, on the 4th, the 7th and the 20th days. These results and their comparison with other works emphasize that a fall of concentration in lipids precedes the phase of highest concentration in secondary metabolites of polyketide type; it appears that fats and particularly palmitic acid are present in biogenesis of these derivatives.

The use of the rhodamine B as fluorescent tracer in hydrology ask the question of its possible toxic effects in the environment. This study aspire to specify and to complete the results of the former works by the successive examinations of the activity of the rhodamine B in regard to the "daphnies test", its DL50 on the rat and on the mouse, and its cutaneous tolerance. The obtained results confirm the former remarks and express that the solutions of the rhodamine B show any more immediate risks as soon as they appear no more coloured (higher dilutions 1.10(-7)). However it remains to evaluate its long-term carcenogenic activity.

Lucerne and ray-grass, sterilized or not, were equilibrated at relative humidity (E.R.H.) 84, 88, 93 p. 100, and contaminated by spores of a highly toxinogenic A. Versicolor strain and maintained in these E.R.H. during 6 months. A peculiar technique for extraction and purification was necessary; the quantification limit for sterigmatocystin was 100 ppb; measurements had been done monthly in 3 replicates. Solvent water was estimated from water sorption isotherms: Toxin yield progressively increases, then lowers and, at last, becomes stable between 1200 and 2000 p.p.b.; The maximal yield is all the higher and the different evolution stages are all the shorter as E.R.H. is higher. The substrate nature influence is different according to E.R.H.; The toxin yields are about twice lower in unsterilized forages. The main parameter for fungal development and toxinogenesis, in low E.R.H. conditions, appears to be the solvent water concentration. Taking into consideration the weak yields of sterigmatocystin obtained in these conditions with a highly toxinogenic strain, the hazard of sterigmatocystin as a natural contaminant in these forages is low, in spite of the high frequency of this fungal species.

Laboratory and field tests revealed that the addition of Erio acid red XB 400 dye (EAR) to Bacillus thuringiensis formulations inhibited spores of the bacillus. In the laboratory, 74% of the spores present in a suspension containing 16 X 10(9) viable spores/mL, and 0.25 gm/l of EAR, were inhibited after 28 h. Spore inactivation in a physiological solution containing 1 X 10(7) viable spores/mL was 75% after the same period of exposure to the same EAR concentration. Field tests showed a reduction in the number of viable spores in a suspension exposed to sunlight; a suspension of 75 000 viable spores/mL yielded 2000 and 400 viable spores/mL after 2 and 4 h of exposure to sunlight, while the same suspension added with 2.5 ppm EAR yielded 1000 and 100 viable spores/mL after the same periods of exposure. The photodynamic action of sunlight on the dye provokes a chemical reaction (oxidation) and the inactivation effect of EAR increases with temperature. Consequently, use of EAR is incompatible with B. thuringiensis formulations and methods used for deposit assessment, based on the use of EAR, should be modified accordingly.

The mixture at equal volumes of a 0.1 p. 100 solution of rhodamine B in distilled water and of a 0.25 p. 100 solution of toluidine blue in Walpole's pH 4.4 buffer dyes each pilar sheath differently. At the level of the medulla, the granules fix rhodamine B, so do the cortical cells at the level of the keratogenic zone. Once they are keratinized, however, cortical cells remain colorless. Concerning the cells of the inner root sheath, on the other hand, their trichohyaline granules are dyed by rhodamine B, whereas the keratinized cells turn dark blue under the effect of toluidine blue. The trichilemmal keratin both of the isthmus of the anagen hair and of the follicular sac becomes light red. This technique, which can be easily applied to the trichogram, allows us to identify more or less mature pilar anlages in in adnexal tumors, to differentiate keratinizing cysts and to trace various pathological keratins. Thanks to a chemical study, it was shown that the mixture rhodamine B-toluidine blue is only a mechanical mixture which works through its acide-bases properties.