Bio-derived hydroxystearic acid ameliorates skin age spots and conspicuous pores.

INTRODUCTION: We report on the preparation and efficacy of 10-hydroxystearic acid (HSA) that improves facial age spots and conspicuous pores. METHODS: The hydration of oleic acid into HSA was catalyzed by the oleate hydratase from Escherichia coli. Following treatment with HSA, collagen type I and type III was assessed in primary human dermal fibroblasts together with collagen type III, p53 protein levels and sunburn cells (SBC) after UVB irradiation (1 J cm-2 ) by immunohistochemistry on human ex vivo skin. UVB-induced expression of matrix metalloprotease-1 (MMP-1) was determined from full thickness skin by RT-qPCR. Modification of the fibroblast secretome by HSA was studied by mass-spectrometry-based proteomics. In a full-face, double blind, vehicle-controlled trial HSA was assessed for its effects on conspicuous facial pore size and degree of pigmentation of age spots in Caucasian women over an 8-week period. RESULTS: HSA was obtained in enantiomeric pure, high yield (≥80%). Collagen type I and type III levels were dose-dependently increased (96% and 244%; P < 0.01) in vitro and collagen type III in ex vivo skin by +57% (P < 0.01) by HSA. HSA also inhibited UVB-induced MMP-1 gene expression (83%; P < 0.01) and mitigated SBC induction (-34% vs. vehicle control) and reduced significantly UV-induced p53 up-regulation (-46% vs. vehicle control; P < 0.01) in irradiated skin. HSA modified the fibroblast secretome with significant increases in proteins associated with the WNT pathway that could reduce melanogenesis and proteins that could modify dermal fibroblast activity and keratinocyte differentiation to account for the alleviation of conspicuous pores. Docking studies in silico and EC50 determination in reporter gene assays (EC50 5.5 × 10-6  M) identified HSA as a peroxisomal proliferator activated receptor-α (PPARα) agonist. Clinically, HSA showed a statistically significant decrease of surface and volume of skin pores (P < 0.05) after 8 weeks of application and age spots became significantly less pigmented than the surrounding skin (contrast, P < 0.05) after 4 weeks. CONCLUSION: HSA acts as a PPARα agonist to reduce the signs of age spots and conspicuous pores by significantly modulating the expression of p53, SBC, MMP-1 and collagen together with major changes in secreted proteins that modify keratinocyte, melanocyte and fibroblast cell behavior.

INTRODUCTION: voici notre rapport sur la préparation et l'efficacité de l'acide 10-hydroxystéarique (AHS) qui atténue les taches de vieillesse faciale et améliore l'apparence des pores. MÉTHODES: l'hydratation de l'acide oléique en AHS a été catalysée par l'hydratase d'oléate à partir de l'Escherichia coli. Après un traitement par AHS, les collagènes de type I et de type III ont été analysés dans des fibroblastes dermiques humains primaires, ainsi que le taux de collagène de type III et de protéine p53, et les cellules provenant de coups de soleil (sunburn cells, SBC) après irradiation par UVB (1 J cm−2 ) par immunohistochimie sur de la peau humaine ex vivo. L'expression de la matrice métalloprotéase-1 (MMP-1) induite par les UVB a été déterminée à partir d'un échantillon de pleine épaisseur de peau par RT-qPCR. La modification du sécrétome des fibroblastes par l'AHS a été étudiée par analyse protéomique basée sur une spectrométrie de masse. Dans une étude du visage entier, en double aveugle, contrôlée par excipient, l'AHS a été évaluée pour ses effets sur la taille des pores apparents du visage et sur le degré de pigmentation de taches de vieillesse chez des femmes de race blanche sur une période de 8 semaines. RÉSULTATS: l'AHS a été obtenu à un haut rendement, énantiomérique pur (≥80 %). Les taux de collagènes de type I et de type III ont augmenté in vitro en fonction de la dose (96 % et 244 %; P < 0.01) et le collagène de type III dans de la peau ex vivo de +57 % (P < 0.01) lors d'un traitement par AHS. L'AHS a également inhibé l'expression génique MMP-1 induite par les UVB (83%; P < 0.01) et a atténuée l'induction des SBC (−34 % par rapport à l'excipient), et a réduit significativement la régulation à la hausse du p53 induite par les UV (−46% par rapport à l'excipient; P < 0.01) sur de la peau irradiée. L'AHS a modifié le sécrétome des fibroblastes avec des augmentations significatives des protéines associées à la voie WNT qui pouvaient réduire la mélanogenèse et des protéines qui pouvaient modifier l'activité des fibroblastes dermiques et la différenciation des kératinocytes pour une atténuation des pores apparents. Des études de docking in silico et la détermination de l'EC50 dans les dosages des gènes rapporteurs (EC50 5.5 × 9 10−6 M) ont identifié l'AHS comme un agoniste du récepteur-α activé par les proliférateurs de peroxysomes (peroxisomal proliferator activated receptor-α, PPARα). Cliniquement, l'AHS a permis une diminution statistiquement significative de la surface et du volume des pores de la peau (P < 0.05) après 8 semaines d'application, et les taches de vieillesse sont devenues significativement moins pigmentées par rapport à la peau environnante (contraste, P < 0,05) après 4 semaines. CONCLUSION: l'AHS agit comme un agoniste du PPARα pour réduire les signes de taches de vieillesse et l'apparence des pores par une modulation significative de l'expression de la protéine p53, des SBC, de la MMP-1 et du collagène avec des changements majeurs dans les protéines sécrétées qui modifient le comportement cellulaire des kératinocytes, des mélanocytes et des fibroblastes.

Protective effects of an extract of the freshwater microalga Scenedesmus rubescens on UV-irradiated skin cells.

BACKGROUND: Skin ageing results from intrinsic but also extrinsic factors of which UV irradiation is a main cause. It is hence of interest to have means to protect skin from UV irradiation-induced damage. We selected an extract of the freshwater microalga Scenedesmus rubescens and assessed its potential to protect skin from photoageing caused by UV irradiation. METHODS: Skin cells in vitro and ex vivo were analysed for markers of UV irradiation-induced photodamage such as decreased viability, decreased collagen content, hyperpigmentation and sunburn cells. RESULTS: We found that a dry extract of the microalga Scenedesmus rubescens was able to suppress cellular signs of ageing induced by UV irradiation. It enhanced dermal fibroblast viability, rescued dermal collagen content, inhibited the formation of sunburn cells and inhibited tyrosinase activity. CONCLUSION: An extract of Scenedesmus rubescens showed broad activity against markers of UV irradiation-induced cutaneous ageing. It may therefore be used as a preventive or regenerative agent for anti-ageing strategies.

Polygonum multiflorum Radix extract protects human foreskin melanocytes from oxidative stress in vitro and potentiates hair follicle pigmentation ex vivo.

OBJECTIVE: To examine the ability of an extract from traditional Chinese medicine, Polygonum multiflorum Radix, to protect melanocyte viability from oxidative stress, a key mechanism in the initiation and progression of hair greying. METHODS: To assess the antioxidant capacity of Polygonum multiflorum Radix extract, primary human foreskin melanocytes were treated with a commercially available Polygonum multiflorum Radix extract added to culture medium and exposed to hydrogen peroxide (H2 O2 ), using intracellular reactive oxygen species concentrations and glutathione/protein ratios as endpoints. To improve solubility for cosmetic uses, a new Polygonum multiflorum Radix extract was derived. As hair greying is the consequence of melanocyte disappearance in an oxidative stress environment, we checked whether the antioxidant capacity of the new Polygonum multiflorum Radix extract could preserve melanocyte viability in response to H2 O2 -induced oxidative stress, and preserve pigmentation within ex vivo human hair follicles. RESULTS: In vitro treatment of primary human foreskin melanocytes with traditional available Polygonum multiflorum Radix extract resulted in decreased intracellular ROS accumulation in response to H2 O2 exposure with a concomitant preservation of glutathione-to-protein ratio, consistent with a protective response against H2 O2 exposure and demonstrating the promise of this extract for protecting melanocytes against oxidative stress. Melanocytes treated with the improved Polygonum multiflorum Radix extract exhibited attenuated H2 O2 -induced cell death, demonstrating a clear cytoprotective effect. Treatment of ex vivo human hair follicles with the improved Polygonum multiflorum Radix extract resulted in a higher level of melanin compared to vehicle-treated controls, demonstrating an ex vivo protective effect on hair pigmentation. CONCLUSION: Polygonum multiflorum Radix extract protects in vitro primary human foreskin melanocytes from the deleterious effects of H2 O2 exposure and improves pigmentation within ex vivo human hair follicles, demonstrating the utility of Polygonum multiflorum Radix extract as a potential active ingredient for the protection of melanocytes against premature death. This data provides in vitro mechanistic evidence consistent with existing in vivo studies for the use of Polygonum multiflorum Radix extract as a strategy for the prevention of oxidative stress-induced hair greying, in line with traditional Polygonum multiflorum Radix uses.

Rosetta's comet 67P/Churyumov-Gerasimenko sheds its dusty mantle to reveal its icy nature.

The Rosetta spacecraft has investigated comet 67P/Churyumov-Gerasimenko from large heliocentric distances to its perihelion passage and beyond. We trace the seasonal and diurnal evolution of the colors of the 67P nucleus, finding changes driven by sublimation and recondensation of water ice. The whole nucleus became relatively bluer near perihelion, as increasing activity removed the surface dust, implying that water ice is widespread underneath the surface. We identified large (1500 square meters) ice-rich patches appearing and then vanishing in about 10 days, indicating small-scale heterogeneities on the nucleus. Thin frosts sublimating in a few minutes are observed close to receding shadows, and rapid variations in color are seen on extended areas close to the terminator. These cyclic processes are widespread and lead to continuously, slightly varying surface properties.

Images of asteroid 21 Lutetia: a remnant planetesimal from the early Solar System.

Images obtained by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) cameras onboard the Rosetta spacecraft reveal that asteroid 21 Lutetia has a complex geology and one of the highest asteroid densities measured so far, 3.4 ± 0.3 grams per cubic centimeter. The north pole region is covered by a thick layer of regolith, which is seen to flow in major landslides associated with albedo variation. Its geologically complex surface, ancient surface age, and high density suggest that Lutetia is most likely a primordial planetesimal. This contrasts with smaller asteroids visited by previous spacecraft, which are probably shattered bodies, fragments of larger parents, or reaccumulated rubble piles.

Organotins (TBT and DBT) in water, sediments, and gastropods of the southern Venice lagoon (Italy).

The release of tributyltin (TBT) from maritime traffic represents one of the main problems of direct, diffuse, and continued contamination of the marine environment. In the present survey, the concentrations of TBT and dibultytin (DBT) in brackish waters, sediments, and the gastropods Nassarius nitidus were evaluated in order to estimate the contamination of the southern part of the Venice lagoon. TBT and DBT were determined by GC-MS/MS. Recent contamination of TBT was found in brackish waters near marinas, whereas the highest concentrations of TBT and DBT were observed in surface sediments at dockyards and harbours. High content of organotin in the gastropods sampled near the dockyards, harbours, and marinas showed a mobilisation from the sediments through the food web. The present study allowed assessment of whether, despite the ban on the use of TBT paints, waters, sediments, and biota were still being contaminated by organotin compounds in the southern Venice lagoon.

Mercury in sediments and Nassarius reticulatus (Gastropoda Prosobranchia) in the southern Venice Lagoon.

The southern basin of the Venice Lagoon has been the focus of fewer studies concerning contamination from heavy metals than the northern and central basins. A recent increase in urban waste waters from Chioggia town, as well as dockyards, shipping and fishing activities, affect this part of the lagoon. The aim of this study was to investigate the total mercury (THg) incidence in sediments and Nassarius reticulatus gastropods in order to assess its distribution and evaluate the level of contamination. THg concentration measured in bottom sediments ranged between 0.1 and 3.4 mg/kg d. wt. The enrichment factor (EF) showed high values (avg. 30, max 49) near the dockyards of Chioggia; the lowest (avg. 9, max 17) were found in the coastal marine sediments near the port entrance of the southern basin. THg in marine scavenger gastropods accumulated in N. reticulatus with concentrations falling within the range of 0.3-1.3 mg/kg d. wt. A positive correlation was found between THg concentration in sediments and in N. reticulatus in all sites, excluding the dockyards. A first local cause for mercury pollution might be attributed to the antifouling paints used in great quantity in the recent past near the town of Chioggia. Moreover, fine suspended sediments associated with tidal flushing are suggested as possibly being the vehicle for pollutant dispersal from the Marghera industrial area to the whole of Venice's lagoon.

The perception of surface folding in static and animated displays.

How do we interpret outline drawings of surfaces? Although pictorial depictions are projectively ambiguous, observers demonstrate definite preferences of interpretation. Additionally, they commit typical errors. A study is reported of one specific arrangement of surfaces as it is represented in outline drawings, namely the arrangement that results when two arbitrary surfaces are joined at a common edge to form an angle in 3-D ('phenomenic folding'). With some of these arrangements, observers report that the angle formed by the two surfaces is zero (complete folding). With others, they report that the angles are greater than zero (incomplete folding). Both interpretations are actually valid. Several investigators have proposed that observer preferences such as these are due t a tendency to prefer a 3-D interpretation that will make the depicted 3-D shape regular. Three experiments were performed to test this regularisation hypothesis. In the first, observers were shown pairs of four-sided polygons joined at one equal side. Their task was to imagine how the smaller polygon could be folded completely towards the larger, and, subsequently, to report on its position after the ('mental folding'). Reported positions were consistent with 3-D interpretations that caused figural regularisations, In the second and third experiments, observers were shown drawings of diamonds and parallelograms folded along a number of differently positioned and oriented segment ('folding edge'). Their task was to estimate verbally the extent of the dihedral angle formed by the two surfaces. Results indicated that the perception of incomplete folding is determined by 3-D interpretation of the orientation of the drawing with respect of the picture plane. In a fourth experiment, observers were asked whether projective equivalences might be disambiguated by animating two kinds of displays that yield the 'incomplete folding' effect but that should be distinguishable on the basis of the trajectories of the vertexes of the folding parts. Results demonstrated that even in these conditions observers are unable to interpret the foldings correctly. These results might be taken to indicate that projective, static information leading to a simpler and more regular interpretation of the display can prevail over explicit motion information that should force the system to achieve a nonregular solution.

The perception of spatial structure with oblique viewing: an explanation for Byzantine perspective?

Earlier work has confirmed that (i) observers can judge divergent receding lines, placed directly in front of them, to be parallel, and (ii) converging lines which are displaced laterally, so that they are viewed obliquely, can also be judged to be parallel. The former observation is in accord with traditional views of perspective while the latter, which is in accord with the depictions of objects found in Byzantine painting, is not in accord with perspective but is predicted by the relative magnitude of the visual angles subtended by the near and far ends of the pair of lines. To investigate whether these effects occurred when the stimulus was clearly three-dimensional, experiments were conducted with a novel apparatus, consisting of a framework of computer-controlled motor-driven luminous rods. This could be remotely adjusted so that all visible sides appeared to be parallel, ie to resemble a cube. Results showed that observers set the sides of this trapezohedron framework as diverging when it was viewed immediately in front of them, a result which is concordant with linear perspective, ie they see the normal projection of a cube as having converging edges. When the framework was displaced from the median plane so that it was viewed obliquely, the sides were set as converging and the magnitude of this effect was significantly related to angle of view, ie observers see the normal projection of a cube as having diverging sides.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in vividness ratings of perceived and imagined patterns.

The present research focuses on the different subjective experiences evoked by perceived and imagined matrices of letters of the alphabet. In three experiments adult subjects were asked to rate the vividness of a letter included in a matrix of letters which varied due to manipulations in colour, rotation and movement. Subjects were asked to observe (perceptual modality), draw and observe (drawing modality), retrieve (memory modality) or imagine (imagery modality) the matrices. For some manipulations of the critical letter (in particular, 45 degrees inclination and high contrast colour), the perceptual modality produced comparatively higher vividness ratings than the other two modalities. The perceptual effect of inclination was also duplicated with the memory modality group. It is argued that different visual processes, either immediate and pre-attentive, or sequential and attentive, may be operating under voluntary control. Although visual imagery varies in some ways from immediate visual perception, the similarities found, between the drawing and imagery modalities, on the one hand, and the perceptual and memory modalities, on the other hand, suggest that they share some common underlying processes.

Why anamorphoses look as they do: an experimental study.

The aim of this research was to understand why anamorphic images break up until they are unrecognizable when the observer's eye moves away from the regularization point. An experimental device was set up allowing the anamorphic deformation of images, consisting of a rotating screen on which figures were projected. The point from which subjects observed the screen was far from the projecting point. The projected figures lengthened equally when the screen rotated either clockwise or counterclockwise. On the other hand, the perceptual result was the opposite: in the former case, a rigid figure was seen rotating around its own vertical axis; in the latter case, the same figure was seen elongating or shortening in a non-rigid manner, without rotating. Since we were in a projective condition, the invariance of the cross-ratio was maintained. Therefore, we were in a situation of non-rigidity, in spite of the invariance of the cross-ratio. Three stimuli, white on a black background, were used in experiment 1. They were a segment, three aligned points, and four aligned points. Subjects had to rotate the screen at will and stop it at the point when they saw the transformation of movement from rigid rotation to non-rigid elongation. The results showed that: (i) in spite of being a projective invariant, the cross-ratio is not always a perceptual invariant too; (ii) the threshold screen position between the two motions was located at the position where the modifications of the solid angle subtended to the stimulus assumed a different trend from that of a sinusoid. Two stimuli were used in experiment 2: a continuous segment and one intersected by four vertical lines. The aim was the same as for experiment 1, but subjects had to repeat it from five different points of observation. The results showed that: (1) there was no significant difference depending on type of stimulus, indicating that the computability of the cross-ratio is not a necessary condition for the execution of the task; (2) the more the observer moved away from the projection axis, the more evident the distortion of the stimulus appeared, in accordance with what happens when observing an anamorphosis; (3) when the metamorphosis from rigid motion to elastic motion was seen the visual angle subtended to the stimulus was constant for all distances from the projection axis, in accordance with the hypothesis of rigidity.

The ceiling of the Church of St Ignatius and the perception of concave surfaces.

This research describes two hitherto unobserved phenomena in the frescoes of the seventeenth century architect and painter, Andrea Pozzo, painted on the vaulted ceiling of the central nave of the Church of St Ignatius in Rome. The present research also reports the results of two experimental studies on the problem of the perception of shapes projected on concave surfaces. A quantitative evaluation of the phenomena perceived from various points of observation is made by means of stimuli projected at various angles on a semicylindrical surface. The validity of the assumption of invariance, and in particular of the projective invariant called the cross-ratio, is discussed within the framework of ecological theories on perception.

Shape, size and relative space position perception in neglect patients.

Shape, size and relative position in space perception were tested in 17 right brain damaged (RBD) patients with neglect symptoms, 10 RBD patients without neglect and 11 controls. Simultaneous pair comparison task in free vision was used. Two arrangements of the visual display were used: side by side and top-bottom. Neglect patients' performance was comparable to RBD and controls in the shape and size test, but was below the other groups in the relative space position test. The selective failure of neglect patients in the position task did not depend on the spatial arrangement of the visual display, which may indicate a general perceptual deficit, rather than a deficit restricted to the neglect hemifield.

Contrast sensitivity and low spatial frequency discrimination in hemi-neglect patients.

Contrast sensitivity for sinusoidal gratings of different spatial frequencies and low spatial frequency discrimination of high contrast squarewave gratings were measured in 26 right brain damaged patients, 15 of whom showed symptoms of spatial hemi-neglect. No difference was present between neglect and non-neglect patients in either task. A difference in contrast sensitivity restricted to low spatial frequencies was present between controls and patients, independent of neglect. Overall, results indicated that spatial vision at threshold and suprathreshold levels is not selectively impaired in patients with hemi-neglect, a finding consistent with theories which postulate a post-perceptual locus of impairment in this syndrome.

Organizational versus geometric factors in mental rotation and folding tasks.

The criteria used in performing mental rotation or mental folding tasks were studied with a paradigm that did not involve reaction times. The hypothesis was that, when perceptual-organizational factors come into conflict with the geometric features required for the correct execution of such tasks, it is the former that prevail. To verify this hypothesis two experiments were carried out. In experiment 1, subjects were asked to imagine quadrilaterals rotating round a rotation axis at different inclinations. Their responses were dependent both on the degree of tilt of the rotation axis and on the degree of tilt of the quadrilateral with respect to the rotation axis. Experiment 2 consisted of the mental execution of a folding task. In this case too, the responses depended on the degree of tilt of the folding axis and also on the complexity of the stimulus outline. In both experiments responses were divided into two groups: (i) geometrically correct responses and (ii) responses which, although incorrect, were based on perceptual-organizational criteria. In the light of the results, some theoretical implications regarding transformation operations executed by means of mental images are discussed.

The Wundt-Jastrow illusion in the study of spatial hemi-inattention.

A new test to detect unilateral neglect was devised using a modified version of the Wundt-Jastrow area illusion. The test was given to three groups of subjects: left brain damaged (LBD), right brain damaged (RBD) patients and controls. Of RBD patients, 40.4% but no LBD patient or control, showed responses inconsistent with the visual illusion when the determinant features of the illusion pointed to the left visual field. These unexpected responses were highly related to a clinical evaluation of the severity of the hemi-inattention disorder. The sensitivity of this test and of other standard measures of hemi-neglect were compared. The possibility of identifying qualitatively different forms of hemi-neglect was also discussed.

A new visual problem: phenomenic folding.

It is possible to produce outline drawings that are perceived as representations of sheets or plates folded over themselves. However, only some of the many possible representations are immediately and necessarily perceived as such. Investigations were carried out to find out which elements must be included in a drawing if a subject is to perceive folding. Four necessary, though not individually sufficient, factors were detected. Other factors which are not necessary but which can intensify the perception of folding were also found. The four necessary factors are: (i) the existence of two phenomenically overlapping figures; (ii) at least one side of the upper figure must perfectly coincide with one side of the lower figure, this common side being defined as the folding line; (iii) the two phenomenically overlapping areas must be on the same side of the folding line; (iv) three segments must converge at the ends of the folding line. Some cognitive processes which appear to be involved in the phenomenon are also discussed.