Clean-up of a pesticide-lanolin mixture by gel permeation chromatography.
(1/11)
In this study, the efficiency of a clean-up method by gel permeation chromatography (GPC) for the separation of pesticides from lanolin is analyzed. The pesticides analyzed belong to two different families, organophosphorous and synthetic pyrethroids. Lanolin, a standard mixture of the pesticides, and a lanolin-pesticides mixture are injected in a GPC column. The recoveries and elution times from the GPC column of lanolin (by a gravimetric method) and pesticides (by gas chromatography-electron capture detector) are determined. From this column, a good separation of the lanolin-pesticides mixture is observed. (+info)
Restoration of phototropic responsiveness in decapitated maize coleoptiles.
(2/11)
The literature indicates that the tip of maize (Zea mays L.) coleoptiles has the localized functions of producing auxin for growth and perceiving unilateral light stimuli and translocating auxin laterally for phototropism. There is evidence that the auxinproducing function of the tip is restored in decapitated coleoptiles. We examined whether the functions for phototropism are also restored by using blue-light conditions that induced a first pulse-induced positive phototropism (fPIPP) and a time-dependent phototropism (TDP). When the apical 5 mm, in which photosensing predominantly takes place, was removed, no detectable fPIPP occurred even if indole-3-acetic acid (lanolin mixture) was applied to the cut end. However, when the blue-light stimulation was delayed after decapitation, fPIPP became inducible in the coleoptile stumps supplied with indole-3-acetic-acid/lanolin (0.01 mg g-1), indicating that phototropic responsiveness was restored. This restoration progressed 1 to 2 h after decapitation, and the curvature response became comparable to that of intact coleoptiles. The results for TDP were qualitatively similar, but some quantitative differences were observed. It appeared that the overall TDP was based on a major photosensing mechanism specific to the tip and on at least one additional mechanism not specific to the tip, and that the tip-specific TDP was restored in decapitated coleoptiles with kinetics similar to that for fPIPP. It is suggested that the photoreceptor system, which accounts for fPIPP and a substantial part of TDP, is regenerated in decapitated coleoptiles, perhaps together with the mechanism for lateral auxin translocation. (+info)
The defensive role of volatile emission and extrafloral nectar secretion for lima bean in nature.
(3/11)
Lima bean (Phaseolus lunatus) features two indirect anti-herbivore defenses--emission of volatile organic compounds (VOCs) and secretion of extrafloral nectar (EFN)--which are both inducible upon herbivore damage. In a previous field study, Lima bean benefited from the simultaneous induction of the two defenses, yet it remained unclear whether both had contributed to plant protection. Our experimental approach aimed at studying the defensive role of both indirect defenses simultaneously. Tendrils were sprayed with jasmonic acid (JA) to induce both defenses, and performance was compared to that of others that were treated with a synthetic blend of either EFN or VOCs. Confirming earlier results, JA treatment and application of the VOC mixture induced EFN secretion in treated tendrils in quantitatively similar amounts. The composition of the applied synthetic blend of EFN was adjusted to match the concentration of EFN secreted from JA- and VOC-treated tendrils. Repeated application of either enhanced the performance of several fitness-relevant plant parameters such as growth rate and flower production. Tendrils treated with JA showed a similar trend, yet some fitness-related parameters responded less to this treatment. This suggests a minor importance of any putative JA-dependent direct defense traits or higher costs of JA-elicited responses as compared to VOCS and EFN, as otherwise JA-treated tendrils should have outperformed VOC- and EFN-treated tendrils. Moreover, the beneficial effect of applying synthetic EFN alone equaled or exceeded that of VOCs and JA. Ants were by far the dominant group among the arthropods that was attracted to JA-, VOC-, or EFN-treated tendrils. The results suggest that EFN plays a more important role as an indirect defense of lima bean than VOCs or any other JA-responsive trait. (+info)
Lanolin-derived lipid mixtures mimic closely the lipid composition and organization of vernix caseosa lipids.
(4/11)
Structural characterization of saturated branched chain fatty acid methyl esters by collisional dissociation of molecular ions generated by electron ionization.
(6/11)
Contact sensitization to the allergens of European baseline series in patients with chronic leg ulcers.
(7/11)
BACKGROUND AND OBJECTIVE: The pattern of contact sensitization among patients with chronic leg ulcers depends on the local practice of wound treatment along with demographic and clinical confounders. The study was aimed at revealing the associations between chronic leg ulcers and contact sensitization. MATERIAL AND METHODS: Between 2006 and 2008, 35 patients with chronic leg ulcers and surrounding dermatitis and 59 patients with contact dermatitis of the lower leg or foot were prospectively recruited at the Department of Skin and Venereal Diseases, Lithuanian University of Health Sciences. Demographic and clinical data were collected in accordance with the "minimal data set" of the European Surveillance System on Contact Allergy. Patch testing was performed with the allergens of the European baseline series. RESULTS: At least one positive patch test reaction was found in 28 (80%) of the patients with chronic leg ulcers and in 24 (41%) of the patients with dermatitis of the lower leg or foot (P<0.001). Sensitization to some of the most common allergens, namely colophony, Myroxylon pereirae resin, and methyldibromo glutaronitrile, was prevalent in both the groups of patients, whereas sensitization to benzocaine, p-phenylenediamine, and lanolin alcohol was associated with the presence of chronic leg ulcers. Benzocaine was found to be the leading allergen among patients with chronic leg ulcers (positive patch test reactions in 34.4% of the patients). CONCLUSIONS: Contact sensitization to benzocaine, p-phenylenediamine, and lanolin was found to be associated with the presence of chronic leg ulcers. (+info)
Efficacy of HPA Lanolin(R) in treatment of lip alterations related to chemotherapy.
(8/11)