[Video screen exposure and 6-sulfatoxymelatonin urinary excretion in women]. / Travail sur écran d'ordinateur et excrétion urinaire de la 6-sulfatoxymélatonine chez la femme.

A study in blind conditions was conducted on 13 women (mean age < 30 years). Six women worked at least four hours per day, five days a week, since more than one month, in front of a video screen constituted the exposed group. Radioimmunoassay of 6-sulfatoxymelatonin was done on urine collected during night. Results were analysed by a non parametric rank-test (Mann-Withney). It was observed an important (- 54%) and significant lower level (p < 0.01) of 6-sulfatoxymelatonin in urine of women exposed to video screen.

Inversion de la abolicion especifica de la actividad hipofisis-suprarrenal y control de la inmunidad humoral en pollos bursectomizados, mediante bursina muy diluida / Invertion of the specific abolition of the pituitary-renal activity and humoral inmunity control in bursectomized chicken by highly diluted bursin

Hemos repetido y comprobado nuestros resultados anteriores que demuestran que la bursina (Lys-His-Gly-NH2) muy diluida produce de forma eficaz y especifica la completa restauracion de la respuesta hipofisis-suprarrenal y de la inmunidad humoral en pollos bursectomizados sensibilizados a la tiroglobulina (Tg) porcina. Asimismo hemos demostrado que la bursina muy diluida tambien es un organizador ontogenico especifico de los ritmos circadianos de las hormonas hipofisario-suprarrenales.En embriones de pollo de cuatro dias de edad bursectomizadis, inhibimos la respuesta hipofisaria (corticotropina: ACTH), suprarrenal (corticosterona: CORT) y de anticuerpos especificos (IgG) a la inmunizacion frente a Tg porcina: en pollos...(AU)

Biological effects of continuous exposure of embryos and young chickens to electromagnetic fields emitted by video display units.

The effects of continuous exposure of embryos and young chickens to electromagnetic fields (EMFs) emitted by video display units (VDUs) were investigated. Embryos and brood were continuously exposed during embryonic and postembryonic phases to EMFs emitted by two types of VDU (TV or computer). Embryonic mortality was evaluated in three independent experiments. Young chickens were immunized three times by porcine thyroglobulin (Tg). Blood samples were assayed after each immunization for specific anti-Tg antibodies (IgG), plasma corticosterone (CORT), and plasma melatonin (MLT). In the sham-exposed samples, embryonic death (10-33%) was restricted to the perinatal period and the IgG, CORT, and MLT responses of young chickens crested after the second immunization. Constant EMF exposure was accompanied by significantly increased fetal loss (47-68%) and markedly depressed levels of circulating anti-Tg IgG, CORT, and MLT. Collectively, these findings indicate that continuous exposure to EMFs, issuing from VDUs, adversely affects embryos and young chickens.

A role for bursa fabricii and bursin in the ontogeny of the pineal biosynthetic activity in the chicken.

The tripeptide bursin (Lys-His-Gly-NH2) is a B cell differentiation hormone derived from the bursa fabricii. The latter is a cloacal diverticulum and the site of B lymphocyte differentiation and selection in aves; also the bursa fabricii is involved in endocrine functions. Herein we demonstrate that in the chicken, the bursa fabricii and bursin are crucial to the ontogeny of both the pineal response to antigenic challenge and pineal circadian synthetic activity. In early embryonically bursectomized chickens, the plasma melatonin response to immunization by porcine thyroglobulin (Tg) was abolished. Also, the amplitudes of both plasma melatonin and pineal N-acetyltransferase (NAT) circadian rhythms were reduced by 50%, whereas the activity of hydroxyindole-O-methyltransferase (HIOMT) remained unchanged. Conversely, administration of either minute amounts (100 pg, 100 fg) or highly dilute (5 x 10(-27) g) bursin, with the exception of a highest dose (100 micrograms), to bursaless embryos induced recovery of normal antigen-induced melatonin response and normal amplitudes of melatonin and NAT rhythms. These findings establish that early in embryonic life, the bursa fabricii and its derived signal (bursin) are essential for normal development of pineal synthetic activity and underline the efficacy of very dilute bursin as an informative signal.

Bursine diluee: validation des hautes dilutions / Diluted bursin: validation of the high dilutions

L'article est une etape important vers la reconnaissance et la generalisation du concept d'immunomodulation a tres faibles doses developpe par le professeur M. Bastide il y a maintenant plus de 15 ans. La thymuline... (AU)