Pigmentation effects of blue light irradiation on skin and how to protect against them.

BACKGROUND: Visible light, in particular blue light, has been identified as an additional contributor to cutaneous photoageing. However, clinical studies demonstrating the clear effect of blue light on photoageing are still scarce, and so far, most studies have focused on broad-spectrum visible light. Although there is evidence for increased skin pigmentation, the underlying mechanisms of photoageing in vivo are still unclear. Furthermore, there is still a need for active ingredients to significantly protect against blue light-induced hyperpigmentation in vivo. Our study had two aims: to detect visible changes in skin pigmentation following repeated irradiation of the skin with LED-based blue light and to reduce pigmentation using suitable active ingredients. METHOD: We conducted a randomized, double-blind and placebo-controlled clinical study on 33 female volunteers with skin phototypes III and IV. We used a repetitive blue light (4 × 60 J cm-2 , 450 nm) irradiation protocol on the volunteers' inner forearms. Using hyperspectral imaging, we assessed chromophore status. In addition, we took chromameter measurements and photographs to assess visible hyperpigmentation. RESULTS: We measured significant changes in chromophore status (P < 0.001 vs baseline), that is of melanin, haemoglobin and oxygen saturation, immediately after blue light irradiation. In addition, we found visible skin colour changes which were expressed by a significant decrease in ITA° values (delta ITA° = -16.89, P < 0.001 vs baseline for the placebo group) and an increase in a* (delta a* = +3.37, P < 0.001 vs baseline for the placebo group) 24 h post-irradiation. Hyperpigmentation and skin reddening were mitigated by both a formulation containing 3% of a microalgal product and a formulation containing 3% niacinamide. CONCLUSION: Our study sets out an efficient and robust protocol for investigating both blue light-induced cutaneous alterations, such as changes in skin chromophores, and signs of photoageing, such as hyperpigmentation. Moreover, we have shown evidence that both an extract of the microalga Scenedesmus rubescens and niacinamide (vitamin B3) have the potential to protect against blue light-induced hyperpigmentation.

CONTEXTE: La lumière visible, en particulier la lumière bleue, a été identifiée comme un facteur supplémentaire du photo-vieillissement cutané. Cependant, les études cliniques, démontrant l'effet réel de la lumière bleue sur le photo-vieillissement, sont encore rares et jusqu'à présent, la plupart des études portaient sur l'influence de la lumière visible à large spectre. Bien qu'il y ait des preuves concernant l'effet sur la pigmentation de peau, les mécanismes sous-jacents du photo-vieillissement in vivo sont encore peu clairs. De plus, le besoin d'ingrédients actifs protégeant de manière significative en in vivo contre l'hyperpigmentation induite par la lumière bleu est toujours présent. NOTRE ÉTUDE A EU DEUX OBJECTIFS: Détecter des changements visibles dans la pigmentation de la peau à la suite d'une irradiation répétée avec de la lumière bleue à base de LED, et réduire la pigmentation à l'aide d'ingrédients actifs adaptés. MÉTHODE: Nous avons mené une étude clinique randomisée, à l'aveugle et controlée avec un placebo sur 33 volontaires féminins de phototypes de peau III et IV. Nous avons défini un protocole d'irradiation répétitif à lumière bleue (4 x 60 J cm-2, 450 nm) sur les avant-bras intérieurs des volontaires. En utilisant l'imagerie hyperspectrale nous avons évalué l'état de chromophore. En outre, nous avons pris des mesures de couleur et des photographies pour évaluer l'hyperpigmentation de manière visuelle. RÉSULTATS: Nous avons mesuré des changements significatifs dans le statut de chromophore (p<0.001 par rapport au statut initial), par exemple au niveau de la mélanine, de l'hémoglobine et de la saturation en oxygène, immédiatement après l'irradiation à lumière bleue. De plus, nous avons constaté des changements visibles de couleur de la peau qui ont été exprimés par une diminution significative des valeurs ITA° (delta ITA° valeurs = -16.89, p<0.001 par rapport au statut initial pour le groupe placebo), et une augmentation de a* (delta a* = +3.37, p <0.001 par rapport au statut initial pour le groupe placebo) 24 heures après l'irradiation. L'hyperpigmentation et les rougeurs de la peau ont été atténués par une formulation contenant 3% d'un extrait d'algue ainsi que par une formulation contenant 3% de niacinamide. CONCLUSION: Notre étude a établi un protocole efficace et robuste pour étudier à la fois les altérations cutanées induites par la lumière bleue, telles que les changements dans les chromophores de la peau, ainsi que les signes de photo-vieillissement, tels que l'hyperpigmentation. Enfin, nous avons prouvé qu'un extrait de l'algue Scenedesmus rubescens et la niacinamide (vitamine B3) avaient le potentiel de protéger contre l'hyperpigmentation induite par la lumière bleue.

Revealing the secret life of skin - with the microbiome you never walk alone.

The human skin microbiome has recently become a focus for both the dermatological and cosmetic fields. Understanding the skin microbiota, that is the collection of vital microorganisms living on our skin, and how to maintain its delicate balance is an essential step to gain insight into the mechanisms responsible for healthy skin and its appearance. Imbalances in the skin microbiota composition (dysbiosis) are associated with several skin conditions, either pathological such as eczema, acne, allergies or dandruff or non-pathological such as sensitive skin, irritated skin or dry skin. Therefore, the development of approaches which preserve or restore the natural, individual balance of the microbiota represents a novel target not only for dermatologists but also for skincare applications. This review gives an overview on the current knowledge on the skin microbiome, the currently available sampling and analysis techniques as well as a description of current approaches undertaken in the skincare segment to help restoring and balancing the structure and functionality of the skin microbiota.

Le microbiome de la peau humaine est récemment devenu un centre d'intérêt pour les domaines dermatologique et cosmétique. Comprendre le microbiote cutané, à savoir la collection de microorganismes vitaux vivant sur notre peau, et comment maintenir son équilibre délicat est une étape essentielle pour mieux comprendre les mécanismes responsables d'une peau saine et son apparence. Les déséquilibres dans la composition microbiotique de la peau (dysbiose) sont associés à plusieurs affections cutanées, soit pathologiques comme l'eczéma, l'acné, les allergies ou les pellicules, soit non pathologiques comme la peau sensible, irritée ou sèche. Par conséquent, le développement d'approches qui préservent ou restaurent l'équilibre naturel et individuel du microbiote représente une nouvelle cible non seulement pour les dermatologues mais aussi pour les experts en cosmétiques. Cette revue donne un aperçu des connaissances actuelles sur le microbiome cutané, les techniques d'échantillonnage et d'analyse actuellement disponibles ainsi qu'une description des approches actuelles entreprises dans le segment des soins de la peau pour aider à restaurer et équilibrer la structure et la fonctionnalité du microbiote de la peau.

An image-based mapping of significance and relevance of facial skin colour changes of females living in Thailand.

OBJECTIVE: There are methods to evaluate skin colour on defined areas over the face but no approach automatically and accurately evaluates skin colour variations on large facial areas, comparing subjects, treatments and/or time points. We propose such an image-based approach to visualize quickly the outcome of clinical studies on colour variations. METHODS: Among 54 Asian women, one group applied a vehicle twice daily, during 28 days, and the other group an anti-ageing emulsion, taking facial images at baseline and after treatment. Changes in L*a*b* values were studied on four pre-selected facial regions. We also reconstructed average facial images from which the L*a*b* parameters were extracted for every pixel, computing relevance (ΔE) and significance data. Using colour gradients, we mapped these results onto the average facial images. RESULTS: After treatment, L*a*b* parameters show no statistically relevant colour changes in the vehicle group. In the 'active' group, skin was lighter at the upper cheek and, overall, redness decreased. Relevance and significance maps confirmed no visible colour changes in the vehicle group. In the 'active' group, the mapping approach revealed colour changes and their location. Skin became lighter below the eye, cheek and forehead. It was less red below the eyes, on the cheek, jawline and forehead, and generally more yellow. CONCLUSION: Our image-based mapping approach proves to be powerful. It enables us to identify precise facial regions of relevant and statistically significant colour changes after a topical treatment, regions that would have otherwise been undetected.

OBJECTIF: Il existe des méthodes pour évaluer la couleur de la peau sur des zones pré-définies du visage mais aucune approche n'évalue de manière automatique et précise les variations de couleur de peaux sur de large régions du visage, en comparant les sujets, les traitements et/ou les temps d'analyse. Nous proposons une telle méthode basée sur l'analyse d'images pour visualiser de manière rapide les résultats des études cliniques portant sur des variations colorimétriques. MÉTHODES: Parmi 54 femmes d'origine asiatique, un premier groupe a appliqué un véhicule deux fois par jour, pendant 28 jours. Un deuxième groupe a, lui, appliqué une émulsion anti-âge. Des images de visage ont été réalisées avant et après traitement. Les variations des valeurs L*a*b* ont été étudiées sur quatre régions du visage pré-sélectionnées. Nous avons également reconstruit des images de visages moyens pour lesquelles les paramètres L*a*b* ont été extraits pour chaque pixel. Pour ces mêmes pixels, les valeurs de pertinence (delta E) et significativité ont été calculées. A l'aide d'un gradient de couleur, nous avons représenté ces résultats sur les images de visages moyens. RÉSULTATS: Après traitement, les paramètres L*a*b* n'ont montré aucun résultat significativement pertinent pour le groupe ayant appliqué le véhicule. Pour le groupe "actif", la peau est devenue plus claire sur la partie supérieure de la joue et globalement moins rouge. Les cartographies de pertinence et de significativité ont confirmée l'absence de variation colorimétrique sur le groupe véhicule. Sur le groupe "actif", l'approche par cartographie a révélé les changements de couleurs et leur localisation. La peau est devenue plus claire sous les yeux, sur les joue et le front. Le dessous des yeux, les joues, la mâchoire et le front sont devenues moins rouges et généralement plus jaunes. CONCLUSION: Notre approche de cartographie basé sur l'analyse d'images s'est montrée pertinente. Elle nous permet d'identifier de manière précise les régions du visage sur lesquelles des changements pertinents et significatifs de couleur ont eu lieu après l'application d'un traitement topique. Ces régions n'auraient pas été détectées sans cette technique.

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.

The effects of benzylsulfonyl-D-Ser-homoPhe-(4-amidino-benzylamide), a dual plasmin and urokinase inhibitor, on facial skin barrier function in subjects with sensitive skin.

OBJECTIVE: The aim of this study was to optimize the synthesis of the plasmin and urokinase (uPA) inhibitor benzylsulfonyl-D-Ser-homoPhe-(4-amidino-benzylamide) (BSFAB), to characterize its activity and mechanism of action and to assess its use to improve stratum corneum (SC) barrier function. METHODS: Peptide coupling methods were used to synthesize BSFAB, and high-performance liquid chromatography-mass spectrometry (HPLC-MS) together with 1 H- and 13 C-nuclear magnetic resonance spectroscopy (NMR) were applied to clarify its structure and determine its purity. Its binding mode was determined by docking studies to the catalytic domains of plasmin and uPA. Inhibition constants (Ki ) were determined by enzyme kinetic studies, and the effect of BSFAB on plasmin, uPA and transglutaminase 1 expression was evaluated in non-cytokine and cytokine-stimulated keratinocytes. A vehicle-controlled clinical study on SC barrier function was conducted on facial skin of subjects with self-perceived sensitive skin. RESULTS: BSFAB was synthesized with high purity (97.3%). In silico studies indicated that the amidine moiety of BSFAB was anchored in the S1 pocket of both enzymes by binding to Asp189, Ser190 and Gly219, whereas the backbone of the D-Ser residue makes an anti-parallel ß-sheet interaction with Gly216. BSFAB was shown to be an effective inhibitor of plasmin and uPA with Ki values of 29 and 25 nM, respectively. BSFAB also inhibited keratinocyte-secreted protease activities in basal (plasmin inhibition 37.7%, P < 0.05 and uPA inhibition 96.6%, P < 0.01) and cytokine-induced conditions (plasmin inhibition 41.1%, P < 0.05 and uPA inhibition 97.0%, P < 0.001) and stimulated the gene expression of transglutaminase 1 in cytokine-stimulated keratinocytes (approximately 4.5 times increased expression, P < 0.01). Clinically, BSFAB was shown to improve SC barrier integrity (P < 0.02 on day 29) and subjective improvements in the perception of healthy skin (P < 0.05 on day 28). CONCLUSION: BSFAB binds as a reversible competitive inhibitor to the active sites of plasmin and uPA. Additionally, BSFAB positively improved keratinocyte differentiation gene expression (transglutaminase 1). These effects were translated into improvements in SC barrier integrity clinically in subjects with dry and sensitive skin and improved their perception of having a healthy skin condition.

Neurosurgery at the University of Lausanne.

The University of Lausanne was founded in 1537. The faculty of medicine was created in 1890, and the service of surgery was directed by César Roux. Roux, a well-known surgeon, was visited by Harvey Cushing during 1900-1901. In the early 1930s, Jean Rossier from Lausanne trained with Cushing, but Rossier passed away in 1942. Eric Zander created the division of neurosurgery in 1959; it became an independent service in 1967. Nicolas de Tribolet served as chairman from 1984 until 1994, when he was asked to take charge of the merger of the university services of Geneva and Lausanne. In October 1997, Jean-Guy Villemure joined him in the newly merged department, becoming chairman in Lausanne, while de Tribolet is chairman in Geneva and head of the department comprising both services.

Long-term results after ventriculo-atrial shunting in children.

A consecutive series of 120 patients with infantile hydrocephalus who were submitted to ventriculo-atrial shunting was studied. The average follow-up was 11 years. There was no operative mortality; 7 patients died during the follow-up period, but only in 1 case was the cause of death a consequence of the shunt procedure. The incidence rates of infection and slit ventricle syndrome were 4.2% and 1.8%, respectively. Shunt revision was performed on 253 occasions yielding a revision rate of 2.2 per patient. Of these 253 revisions 167 (66%) took the form of elective lengthening of the atrial catheter. The number of reoperations to adjust the length of the atrial catheter or to revise the distal end of the shunting system is a major disadvantage, which actually favors ventriculo-peritoneal shunting as the primary procedure for the treatment of pediatric hydrocephalus.

Long-term results after ventriculoatrial shunting in children.

A consecutive series of 120 patients with infantile hydrocephalus who were subjected to ventriculoatrial shunting was studied. The average length of follow-up was 11 years. Operative mortality was zero. Seven patients died during the follow-up period; in all cases but one of these the cause of death was not a consequence of a shunt-related procedure. The incidences of infection and slit ventricle syndrome were 4.2% and 1.8% respectively. Two hundred and fifty-three shunt revisions were performed, yielding a revision rate of 2.2 per patient. Of these 253 revisions 167 (66%) were elective lengthening of the atrial catheter. The number of reoperations for adjusting the length of the atrial catheter of for revision of the distal end of the shunting system is a major disadvantage of ventriculoatrial shunting which actually speaks in favor of ventriculoperitoneal shunting as the primary procedure for the treatment of pediatric hydrocephalus.

[Diagnosis, treatment and course of hypophyseal tumors. Retrospective study of 123 cases]. / Diagnostic, traitement et évolution des tumeurs hypophysaires. Etude rétrospective de 123 cas.

To assess the diagnostic and therapeutic problems associated with pituitary tumors, the clinical records of 123 consecutive patients presenting with radiological changes consistent with pituitary tumors were analyzed retrospectively. This diagnosis was established in 109 cases while the remaining 14 had other intrasellar pathologies. Prolactinoma in women was diagnosed at a significantly younger age (34.3 years) than in men (54.2 years) or than non-secreting adenoma in both sexes (52.1 years). In the two latter instances there was, on diagnosis, a larger proportion of visual field impairment due to tumor impingement on the visual pathway. Acromegaly was also recognized late, when skeletal changes were marked. The presence of certain symptoms could have suggested the diagnosis of pituitary tumor earlier in most cases. Surgical treatment was somewhat less effective in correcting hormone hypersecretion than in other series but, on the other hand, it caused less pituitary insufficiency and, thus, less additional discomfort to the patients. Hypopituitarism was frequent after transcranial surgery and radiotherapy (more than 50%) but was very rare after transsphenoidal tumorectomy. It appears that earlier diagnosis would result in less frequent visual impairment and hypopituitarism secondary to tumor extension and the necessary treatment.

Redundant nerve roots of the cauda equina. A rare disease?

6 cases of so-called redundant nerve roots of the cauda equina are reported, which brings the total number of cases described in literature to 27. The differential diagnosis of the myelographic picture of tortuous filling defects is discussed. The authors believe that the majority of these cases is caused by chronic compression of the nerve roots.

[Amnestic syndrome in children. Observation of a girl after craniopharyngioma operation]. / Syndrome amnésique chez l'enfant observation d'une fillette opérée d'un craniopharyngiome.

We have followed up the very severe memory troubles of a 12 year old girl after a craniopharyngiomectomy. We discuss the interest of this observation referring in particular to age, since the amnesic syndrome of the child is a little documented area. A tumoral etiology for an amnesic syndrome is rare. In most of such cases craniopharyngioma is at the origin of mnesic troubles in the adult. When craniopharyngioma is quite frequent in the child, an amnesic syndrome is rarely observed.

Cerebral coenurosis. Report of a case with arteritis.

A case of the unusual clinical condition of cerebral coenurosis, the unique parasitic disease that is localized only in the CNS, is reported. The patient had repeated attacks of transient hemiparesis due to intracranial arteritis which was demonstrated by several angiographic studies. The CSF showed a discreet lymphocytosis and increased immunoglobulins. This inflammatory reaction which preceeded the manifestations of the intracranial mass can be explained by the parasitic foreign bodies, the liberation of somatic and metabolic parasitic toxins and the immunological reaction of the organism. The arteritis of the basal intracranial vessels was probably secondary to the inflammatory reaction of the leptomeninges. In presence of the rare association of meningovascular disease and an expanding intracranial lesion a parasitic condition due to a larval stage of Cestodes (Hydatidosis, Cysticercosis, Coenurosis) should be always considered.

[Neuroradiology of hydrocephalus in newborns and infants]. / Les examens neuroradiologiques lors d'hydrocéphalie chez le nouveau-né et l'enfant

Up-to-date views on the various types of infantile hydorcephalus are exposed from a practical neurosurgical point of view. The neuroradiological procedures are divided in 3 groups: the neuroradioisotopes, the angiographies and the pneumographies. They are described and analyzed. Indicators and possibilities are outlined. Their complementary value is stressed.