International Journal of Environmental Analytical Chemistry, 2010
Multiresidue analytical methodologies are being developed for several classes of pesticides, usin... more Multiresidue analytical methodologies are being developed for several classes of pesticides, using either GC or LC techniques coupled with MS detection. However, to reach ultra-low levels, as imposed by recent European Directives, specific extraction methods must be applied. This work intends to present the optimisation steps followed to implement a method to analyse pesticides of different families, as diuron, bentazone
Physical appearance has significant importance psychologically and socially, with skin and hair b... more Physical appearance has significant importance psychologically and socially, with skin and hair being of prime relevance. Effective ingredients that modulate melanin synthesis are of growing interest. Tamoxifen, a widely used selective oestrogen receptor modulator, SERM, was described occasionally in medical case reports as causing grey hair repigmentation. This work aimed to study, in vitro, the effect of tamoxifen and 4-hydroxy-tamoxifen, one of its most bioactive derivatives, on melanin production in human melanocytes. Adult normal human epidermal melanocytes (NHEM) were treated with physiological concentrations of tamoxifen and 4-hydroxy-tamoxifen during 72 hours. Cytotoxicity was evaluated by lactate dehydrogenase (LDH) leakage. Total melanin was quantified by spectrophotometry, and cyclic adenosine monophosphate (cAMP) was determined by competitive ELISA. The relative mRNA levels of several genes involved in melanogenesis were investigated by real-time PCR. Under the conditions used, the results showed that tamoxifen and 4-hydroxy-tamoxifen treatments, none of them toxic to NHEM, induced a time-dependent increase in the amount of melanin released to the culture medium. cAMP, one of the major second messenger in signalling pathways important to melanogenesis, was decreased after treatment. The transcript levels of genes coding for catalase, premelanosome protein and melan-A, directly related to skin and hair pigmentation, showed an increased tendency upon tamoxifen and 4-hydroxy-tamoxifen treatment. Induction of catalase gene expression in NHEM points towards a promelanogenic effect mediated by ROS. According to the results, even in such a short treatment period, tamoxifen and 4-hydroxy-tamoxifen promoted melanin extrusion and they seem to act as melanogenesis stimulators at the molecular level. Our data suggest that SERMs might be a new tool for increasing melanogenesis and might be of great interest for topical formulations in cosmetic industry.
ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-p... more ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-pool) variability of benthic assemblages of rock pools at mid-intertidal level along the shore of Viana do Castelo (North Portugal). Physical traits of rock pools, including size, depth and position along the shore, were also compared between pools. While pools did not differ for any of the examined physical traits, results indicated a clear seasonal difference in the structure of assemblages, including a total of 49 macroalgal and 13 animal taxa. This finding was driven by six taxa that are more abundant in winter (the reef-forming polychaete Sabellaria alveolata, the articulated coralline algae Corallina spp., the brown alga Bifurcaria bifurcata, the encrusting coralline alga Lithophyllum incrustans, the red alga Chondracanthus acicularis and the grazing snails Gibbula spp.) and four algal taxa that are more abundant in summer (the invasive brown Sargassum muticum, the green Ulva spp., the kelp Laminaria ochroleuca and the filamentous red Ceramium spp.). These data provide a new contribution to the knowledge of rock pool systems and have potential implications for monitoring programmes aimed at assessing ecological modifications related to natural and anthropogenic disturbances and for identifying processes responsible for the variability of rock pool assemblages.
Advances in Biochemical Engineering/Biotechnology, 2010
Hair can be engineered at different levels--its structure and surface--through modification of it... more Hair can be engineered at different levels--its structure and surface--through modification of its constituent molecules, in particular proteins, but also the hair follicle (HF) can be genetically altered, in particular with the advent of siRNA-based applications. General aspects of hair biology are reviewed, as well as the most recent contributions to understanding hair pigmentation and the regulation of hair development. Focus will also be placed on the techniques developed specifically for delivering compounds of varying chemical nature to the HF, indicating methods for genetic/biochemical modulation of HF components for the treatment of hair diseases. Finally, hair fiber structure and chemical characteristics will be discussed as targets for keratin surface functionalization.
ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-p... more ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-pool) variability of benthic assemblages of rock pools at mid-intertidal level along the shore of Viana do Castelo (North Portugal). Physical traits of rock pools, including size, depth and position along the shore, were also compared between pools. While pools did not differ for any of the examined physical traits, results indicated a clear seasonal difference in the structure of assemblages, including a total of 49 macroalgal and 13 animal taxa. This finding was driven by six taxa that are more abundant in winter (the reef-forming polychaete Sabellaria alveolata, the articulated coralline algae Corallina spp., the brown alga Bifurcaria bifurcata, the encrusting coralline alga Lithophyllum incrustans, the red alga Chondracanthus acicularis and the grazing snails Gibbula spp.) and four algal taxa that are more abundant in summer (the invasive brown Sargassum muticum, the green Ulva spp., the kelp Laminaria ochroleuca and the filamentous red Ceramium spp.). These data provide a new contribution to the knowledge of rock pool systems and have potential implications for monitoring programmes aimed at assessing ecological modifications related to natural and anthropogenic disturbances and for identifying processes responsible for the variability of rock pool assemblages.
International Journal of Environmental Analytical Chemistry, 2010
Multiresidue analytical methodologies are being developed for several classes of pesticides, usin... more Multiresidue analytical methodologies are being developed for several classes of pesticides, using either GC or LC techniques coupled with MS detection. However, to reach ultra-low levels, as imposed by recent European Directives, specific extraction methods must be applied. This work intends to present the optimisation steps followed to implement a method to analyse pesticides of different families, as diuron, bentazone
Physical appearance has significant importance psychologically and socially, with skin and hair b... more Physical appearance has significant importance psychologically and socially, with skin and hair being of prime relevance. Effective ingredients that modulate melanin synthesis are of growing interest. Tamoxifen, a widely used selective oestrogen receptor modulator, SERM, was described occasionally in medical case reports as causing grey hair repigmentation. This work aimed to study, in vitro, the effect of tamoxifen and 4-hydroxy-tamoxifen, one of its most bioactive derivatives, on melanin production in human melanocytes. Adult normal human epidermal melanocytes (NHEM) were treated with physiological concentrations of tamoxifen and 4-hydroxy-tamoxifen during 72 hours. Cytotoxicity was evaluated by lactate dehydrogenase (LDH) leakage. Total melanin was quantified by spectrophotometry, and cyclic adenosine monophosphate (cAMP) was determined by competitive ELISA. The relative mRNA levels of several genes involved in melanogenesis were investigated by real-time PCR. Under the conditions used, the results showed that tamoxifen and 4-hydroxy-tamoxifen treatments, none of them toxic to NHEM, induced a time-dependent increase in the amount of melanin released to the culture medium. cAMP, one of the major second messenger in signalling pathways important to melanogenesis, was decreased after treatment. The transcript levels of genes coding for catalase, premelanosome protein and melan-A, directly related to skin and hair pigmentation, showed an increased tendency upon tamoxifen and 4-hydroxy-tamoxifen treatment. Induction of catalase gene expression in NHEM points towards a promelanogenic effect mediated by ROS. According to the results, even in such a short treatment period, tamoxifen and 4-hydroxy-tamoxifen promoted melanin extrusion and they seem to act as melanogenesis stimulators at the molecular level. Our data suggest that SERMs might be a new tool for increasing melanogenesis and might be of great interest for topical formulations in cosmetic industry.
ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-p... more ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-pool) variability of benthic assemblages of rock pools at mid-intertidal level along the shore of Viana do Castelo (North Portugal). Physical traits of rock pools, including size, depth and position along the shore, were also compared between pools. While pools did not differ for any of the examined physical traits, results indicated a clear seasonal difference in the structure of assemblages, including a total of 49 macroalgal and 13 animal taxa. This finding was driven by six taxa that are more abundant in winter (the reef-forming polychaete Sabellaria alveolata, the articulated coralline algae Corallina spp., the brown alga Bifurcaria bifurcata, the encrusting coralline alga Lithophyllum incrustans, the red alga Chondracanthus acicularis and the grazing snails Gibbula spp.) and four algal taxa that are more abundant in summer (the invasive brown Sargassum muticum, the green Ulva spp., the kelp Laminaria ochroleuca and the filamentous red Ceramium spp.). These data provide a new contribution to the knowledge of rock pool systems and have potential implications for monitoring programmes aimed at assessing ecological modifications related to natural and anthropogenic disturbances and for identifying processes responsible for the variability of rock pool assemblages.
Advances in Biochemical Engineering/Biotechnology, 2010
Hair can be engineered at different levels--its structure and surface--through modification of it... more Hair can be engineered at different levels--its structure and surface--through modification of its constituent molecules, in particular proteins, but also the hair follicle (HF) can be genetically altered, in particular with the advent of siRNA-based applications. General aspects of hair biology are reviewed, as well as the most recent contributions to understanding hair pigmentation and the regulation of hair development. Focus will also be placed on the techniques developed specifically for delivering compounds of varying chemical nature to the HF, indicating methods for genetic/biochemical modulation of HF components for the treatment of hair diseases. Finally, hair fiber structure and chemical characteristics will be discussed as targets for keratin surface functionalization.
ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-p... more ABSTRACT We investigated the seasonal (winter vs summer and within season) and spatial (between-pool) variability of benthic assemblages of rock pools at mid-intertidal level along the shore of Viana do Castelo (North Portugal). Physical traits of rock pools, including size, depth and position along the shore, were also compared between pools. While pools did not differ for any of the examined physical traits, results indicated a clear seasonal difference in the structure of assemblages, including a total of 49 macroalgal and 13 animal taxa. This finding was driven by six taxa that are more abundant in winter (the reef-forming polychaete Sabellaria alveolata, the articulated coralline algae Corallina spp., the brown alga Bifurcaria bifurcata, the encrusting coralline alga Lithophyllum incrustans, the red alga Chondracanthus acicularis and the grazing snails Gibbula spp.) and four algal taxa that are more abundant in summer (the invasive brown Sargassum muticum, the green Ulva spp., the kelp Laminaria ochroleuca and the filamentous red Ceramium spp.). These data provide a new contribution to the knowledge of rock pool systems and have potential implications for monitoring programmes aimed at assessing ecological modifications related to natural and anthropogenic disturbances and for identifying processes responsible for the variability of rock pool assemblages.
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Papers by Rita Araújo