Quantification of chlorpheniramine maleate enantiomers by ultraviolet spectroscopy and chemometric methods

Chlorpheniramine maleate (CLOR) enantiomers were quantified by ultraviolet spectroscopy and partial least squares regression. The CLOR enantiomers were prepared as inclusion complexes with beta-cyclodextrin and 1-butanol with mole fractions in the range from 50 to 100%. For the multivariate calibration the outliers were detected and excluded and variable selection was performed by interval partial least squares and a genetic algorithm. Figures of merit showed results for accuracy of 3.63 and 2.83% (S)-CLOR for root mean square errors of calibration and prediction, respectively. The ellipse confidence region included the point for the intercept and the slope of 1 and 0, respectively. Precision and analytical sensitivity were 0.57 and 0.50% (S)-CLOR, respectively. The sensitivity, selectivity, adjustment, and signal-to-noise ratio were also determined. The model was validated by a paired t test with the results obtained by high-performance liquid chromatography proposed by the European pharmacopoeia and circular dichroism spectroscopy. The results showed there was no significant difference between the methods at the 95% confidence level, indicating that the proposed method can be used as an alternative to standard procedures for chiral analysis.

Ultraviolet signals ultra-aggression in a lizard

Understanding the role of multiple colour signals during sexual signalling is a central theme in animal communication. We quantified the role of multiple colour signals (including ultraviolet, UV), measures of body size and testosterone levels in settling disputes between male rivals in an elaborately ornamented, African lizard, played out in a large 'tournament' in the wild. The hue and brightness (total reflectance) of the UV throat in Augrabies flat lizards, Platysaurus broadleyi, as well as body size, were consistent and strong predictors of 'fighting ability'. Males with high fighting ability were larger and displayed a UV throat with low total reflectance. In contrast, males with low fighting ability were smaller and had violet throats with broader spectral reflectance curves (higher total reflectance). As fighting ability is associated with alternative reproductive tactics in this system (territorial versus floater), we also examined the role of colour signals in predicting male reproductive tactic. Territorial males had UV throats with higher chroma but had poorer body condition than floater males, probably because of the energetic costs of maintaining a territory. Although testosterone was not a significant predictor of fighting ability or reproductive tactic, it was correlated with the hue of the UV throat, suggesting that testosterone may impose some constraint on signal expression. Lastly, we show that within the context of the natural signalling environment, UV-reflective throats constitute a conspicuous, effective signal that male Augrabies flat lizards use to advertise their status honestly to rivals. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Collagen crosslinking with riboflavin and ultraviolet-A in eyes with pseudophakic bullous keratopathy

PURPOSE: To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) in patients with painful pseudophakic bullous keratopathy (PBK). SETTING: University of Sao Paulo, Sao Paulo and Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil. METHODS: This prospective study included consecutive eyes with PBK that had CXL. After a 9.0 mm epithelial removal, riboflavin 0.1% with dextran 20% was applied for 30 minutes followed by ultraviolet-A irradiation (370 nm, 3 mW/cm(2)). Therapeutic contact lenses were placed for 1 week. Corneal transparency, central corneal thickness (CCT), and ocular pain were assessed preoperatively and 1 and 6 months postoperatively. Statistical analysis was by paired t tests. RESULTS: Fourteen patients (14 eyes) with a mean age 71.14 years +/- 11.70 (SD) (range 53 to 89 years) were enrolled. Corneal transparency was better in all eyes 1 month after surgery. At 6 months, corneal transparency was similar to preoperative levels (P = .218). The mean CCT was 747 mu m preoperatively and 623 mu m at 1 month; the decrease was statistically significant (P<.001). At 6 months, the mean CCT increased to 710 mu m, still significantly thinner than preoperatively (P = .006). Pain scores at 6 months were not significantly different than preoperatively (P = .066). CONCLUSIONS: Corneal CXL significantly improved corneal transparency, corneal thickness, and ocular pain 1 month postoperatively. However, it did not seem to have a long-lasting effect in decreasing pain and maintaining corneal transparency in patients with PBK.

Ocular media transmission of coral reef fish - can coral reef fish see ultraviolet light?

Many coral reef fish are beautifully coloured and the reflectance spectra of their colour patterns may include UVa wavelengths (315-400 nm) that are largely invisible to the human eye (Losey, G. S., Cronin, T. W., Goldsmith, T. H., David, H., Marshall, N. J., & McFarland, W.N, (1999). The uv visual world of fishes: a review. Journal of Fish Biology, 54, 921-943; Marshall, N. J. & Oberwinkler, J. (1999). The colourful world of the mantis shrimp. Nature, 401, 873-874). Before the possible functional significance of UV patterns can be investigated, it is of course essential to establish whether coral reef fishes can see ultraviolet light. As a means of tackling this question, in this study the transmittance of the ocular media of 211 coral reef fish species was measured. It was found that the ocular media of 50.2% of the examined species strongly absorb light of wavelengths below 400 nm, which makes the perception of UV in these fish very unlikely. The remaining 49.8% of the species studied possess ocular media that do transmit UV light, making the perception of UV possible. (C) 2001 Elsevier Science Ltd. All rights reserved.

alpha-melanocyte stimulating hormone potentiates p16/CDKN2A expression in human skin after ultraviolet irradiation

The contribution of the UV component of sunlight to the development of skin cancer is widely acknowledged, although the molecular mechanisms that are disrupted by UV radiation (UVR) resulting in the loss of normal growth controls of the epidermal stem cell keratinocytes and melanocytes is still poorly understood. alpha-Melanocyte stimulating hormone (alpha-MSH), acting via its receptor MC1, has a key role in skin pigmentation and the melanizing response after exposure to UVR. The cell cycle inhibitor p16/CDKN2A also appears to have an important function in a cell cycle checkpoint response in skin after exposure to UVR. Both of these genes have been identified as risk factors in skin cancer, MC1R variants are associated with increased risk to both melanoma and nonmelanoma skin cancers, and p16/CDKN2A with increased risk of melanoma. Here we demonstrate that the increased expression of p16 after exposure to sub-erythemal doses of UVR is potentiated by alpha-MSH, a ligand for MC1R, and this effect is mimicked by cAMP, the intracellular mediator of alpha-MSH signaling via the MC1 receptor. This link between p16 and MC1R may provide a molecular basis for the increased skin cancer risk associated with MC1R polymorphisms.

Ultraviolet signals in birds are special

Recent behavioural experiments have shown that birds use ultraviolet (UV)-reflective and fluorescent plumage as cues in mate choice. It remains controversial, however, whether such UV signals play a special role in sexual communication, or whether they are part of general plumage coloration. We use a comparative approach to test for a general association between sexual signalling and either UV-reflective or fluorescent plumage. Among the species surveyed, 72% have UV colours and there is a significant positive association between UV reflectance and courtship displays. Among parrots (Psittaciformes), 68% of surveyed species have fluorescent plumage, and again there is a strong positive association between courtship displays and fluorescence. These associations are not artefacts of the plumage used in courtship displays, being generally more 'colourful' because there is no association between display and colours lacking UV reflectance or fluorescence. Equally, these associations are not phylogenetic artefacts because all results remain unchanged when families or genera, rather than species, are used as independent data points. We also find that, in parrots, fluorescent plumage is usually found adjacent to UV-reflective plumage. Using a simple visual model to examine one parrot, the budgerigar Melopsittacus undulatus, we show that the juxtaposition of UV-reflective and fluorescent plumage leads to a 25-fold increase in chromatic contrast to the budgerigar's visual system. Taken together, these results suggest that signals based on UV contrast are of special importance in the context of active sexual displays. We review briefly six hypotheses on why this may be the case: suitability for short-range signalling; high contrast with backgrounds; invisibility to predators; exploitation of pre-existing sensory biases; advertisement of feather structure; and amplification of behavioural signals.

Biology, ecology and conservation of mobulid rays in the Azores

Dissertação de Mestrado, Estudos Integrados dos Oceanos, 12 de Dezembro de 2013, Universidade dos Açores.

Ultraviolet induction of antifungal activity in plants.

Ultraviolet-C irradiation as a method to induce the production of plant compounds with antifungal properties was investigated in the leaves of 18 plant species. A susceptibility assay to determine the antifungal susceptibility of filamentous fungi was developed based on an agar dilution series in microtiter plates. UV irradiation strongly induced antifungal properties in five species against a clinical Fusarium solani strain that was responsible for an onychomycosis case that was resistant to classic pharmacological treatment. The antifungal properties of three additional plant species were either unaffected or reduced by UV-C irradiation. This study demonstrates that UV-C irradiation is an effective means of modulating the antifungal activity of very diverse plants from a screening perspective.

Ultraviolet reflectance in a melanin-based plumage trait is heritable

Question: Is ultraviolet (UV) reflectance of melanin-based plumage ornaments heritable? Data studied: We considered the barn owl (Two alba), a species that varies continuously from white to reddish-brown, a pheomelanin-based trait. Methods: To perform a partial cross-fostering experiment. we exchanged one to three hatchlings between 16 pairs of nests with a similar hatching date. This experiment allocated hatchlings randomly among rearing environments. Forty-nine days later, we collected three feathers per individual to measure UV reflectance. Conclusions: The cross-fostering experiment showed that. independently of human-visible coloration, variation in UV reflectance is significantly sensitive to origin-related factors.

Enhancement of writings on a damaged medieval manuscript using ultraviolet imaging

The Minutarium Majus, a register dating from the 13th and 14th centuries, was transferred by the paleographers responsible for its transcription to the Institute of Forensic Science of the University of Lausanne with the aim of enhancing portions of text that had become worn away and illegible. The manuscript had suffered from deterioration and damage for different unknown reasons, but most likely because of the colour instability of the ink, contaminations, storage conditions and repeated human manipulation. A total of 69 areas of text, ranging in size from just a few words to full pages, were photographically recorded under both white and ultraviolet (UV) light illumination. UV illumination observed in the visible range proved to be efficient in detecting the writings. Most of the texts could thus be successfully transcribed by the paleographers. The technique proved to be extremely useful for the exposure of damaged medieval writings.

Src is activated by the nuclear receptor peroxisome proliferator-activated receptor β/δ in ultraviolet radiation-induced skin cancer.

Although non-melanoma skin cancer (NMSC) is the most common human cancer and its incidence continues to rise worldwide, the mechanisms underlying its development remain incompletely understood. Here, we unveil a cascade of events involving peroxisome proliferator-activated receptor (PPAR) β/δ and the oncogene Src, which promotes the development of ultraviolet (UV)-induced skin cancer in mice. UV-induced PPARβ/δ activity, which directly stimulated Src expression, increased Src kinase activity and enhanced the EGFR/Erk1/2 signalling pathway, resulting in increased epithelial-to-mesenchymal transition (EMT) marker expression. Consistent with these observations, PPARβ/δ-null mice developed fewer and smaller skin tumours, and a PPARβ/δ antagonist prevented UV-dependent Src stimulation. Furthermore, the expression of PPARβ/δ positively correlated with the expression of SRC and EMT markers in human skin squamous cell carcinoma (SCC), and critically, linear models applied to several human epithelial cancers revealed an interaction between PPARβ/δ and SRC and TGFβ1 transcriptional levels. Taken together, these observations motivate the future evaluation of PPARβ/δ modulators to attenuate the development of several epithelial cancers.