Saccharomyces cerevisiae (YT001) supplementation for the control of Haemonchus contortus and modulation of the immune response of sheep.

Studies aiming at the development and evaluation of alternative methods to minimise losses caused by the gastrointestinal nematode Haemonchus contortus are extremely important. Such research is essential, given the high morbidity rates among sheep and the significant mortality rates of lambs, allied to the low efficacy of commercial products for the control of this parasite. The purpose of this study was to evaluate the effect of the Saccharomyces cerevisiae (YT001 - YEASTECH) on the control of H. contortus and its modulation of the immune response in experimentally infected sheep. Eighteen sheep were divided into two groups. Group 1, the control group, comprised animals infected with H. contortus and supplemented with distilled water, while Group 2, the treated group, consisted of animals infected and supplemented with S. cerevisiae (400 million cfu/day of suspension for 49 days). The following parasitological parameters were evaluated: number of eggs per gram of faeces, number of infective larvae (L3) recovered per faecal culture, and parasitic load of the abomasum. The following immunological parameters were quantified: immunoglobulin (Ig)A in the mucous secretions and serum IgG; cytokines interleukin (IL)-4, IL-5 and IL-10; number of eosinophils in the abomasal mucosa and groups of cells positive for the markers: MHCII, CD4+CD25+, CD5+CD8+, WC4, CD5+CD4+, CD8+CD11b+ and CD5+WC1 by whole blood flow cytometry. The results revealed a significant decrease (P<0.05) in the number of larvae and significantly higher serum IgG levels (P<0.05) in the group supplemented with S. cerevisiae. The supplemented animals showed significantly larger numbers of eosinophils (P<0.05), as well as more cells positive for MHCII, CD4+CD25+, CD5+CD8+ than the control animals. This study confirmed the beneficial action of S. cerevisiae on the host immune response to H. contortus, as evidenced mainly by the smaller number of L3 recovered from the faeces of sheep supplemented with S. cerevisiae.

Gas chromatography mass spectrometry determination of acaricides from honey after a new fast ultrasonic-based solid phase micro-extraction sample treatment.

A method is reported for the determination of acaricides (amitraz, bromopropylate, coumaphos and fluvalinate) from honey by gas chromatography mass spectrometry after a new fast solid phase micro-extraction, SPME, procedure. Six different fibers were assessed for micro-extraction purpose studying the following variables: (i) SPME coating, (ii) extraction temperature, (iii) extraction time, (iv) desorption conditions and (v) agitation conditions. The new ultrasonic bath technology providing different sonication frequencies (35 and 130kHz) and different working modes (Sweep, Standard and Degas) was studied and optimized for speeding up the acaricide micro-extraction. The best extraction results were achieved with the polyacrylate fiber. The extraction process was done in 30min using the ultrasonic bath at 130kHz in the Standard mode. Quality parameters of the proposed method show a good precision (<11%) and detection and quantitation limits lower than 6 and 15ng/g, respectively, except for fluvalinate. Eleven Portuguese commercial honey samples were analyzed with the developed method in order to assess the performance of the method with real samples and to determine whether the concentration of acaricides in honey exceed their maximum residue levels (MRLs). Acaricide residues detected were lower than those established by the legislation.

Long-term selective down-regulation of brain glucocorticoid receptors after neonatal dexamethasone treatment in rats.

The development of corticosteroid receptors may be permanently modified by perinatal hormonal influences. Changes in binding characteristics of corticosteroid receptors were examined in rats treated sc. with 1 microgram/g dexamethasone (DEX) on postnatal day (PND) 1 and subsequently two more times on PND 3 and 5 in several brain areas. [3H]Corticosterone (CORT) binding capacity (Bmax) and affinity (Kd) were determined at 3 weeks old and adult ages by using saturation analysis. The mineralocorticoid type receptor (MR) and the glucocorticoid receptor (GR) sites were measured separately with single point analysis applying a selective glucocorticoid ligand RU 28362 saturating GR. The decrease in CORT binding was due to a selective GR decrement in all structures and the MR concentration was not changed considerably. The basal levels of plasma CORT were not permanently influenced by neonatal DEX. In conclusion, DEX given during the first week of life resulted in long-term and selective down-regulation of GR and this decrement was independent of the actual circulating CORT level.

[Broncho-alveolar lavage in uranium miners (author's transl)]. / Le lavage broncho-alvéolaire chez des mineurs d'uranium.

This study on workers in a uranium mine is principally concerned with the characteristics of the cells recovered by LBA. First, alveolar macrophage function was studied (including viability, phagocytic activity, capillary adherence and migratory activity). Secondly the lymphocytes were identified as T, B, and then their mitogenic responses were studied; occurring spontaneously or in response to phytohemagglutinin or purified protein derivative. Finally, the biochemical aspects were examined (including immunoglobulins, total protein, albumin, phospholipids, potassium, calcium, magnesium, complement components, anti-proteases, etc.). We conclude that there were not demonstrable changes in cellular function in either smokers or non smokers in miners subjected to the ambient radiation of a uranium mine.