Cannabinoid receptors 1 and 2 oppositely regulate epidermal permeability barrier status and differentiation.

Cannabinoid receptors (CBR) 1 and 2 have been implicated in keratinocyte differentiation/proliferation. How CB receptors affect epidermal permeability barrier and stratum corneum structure and function remains unclear. Permeability barrier abrogation was induced by sequential tape-stripping of the SC and assessed in both CB1R and CB2R knockout (-/-) mice in comparison with wild-type (+/+) littermates. Absence of CB1R delays permeability barrier recovery, while the latter was found to be accelerated in CB2R -/- mice. While increased lamellar body (LB) secretion is observed in CB2R -/- mice accounting for the enhanced recovery, CB1R -/- animals display strong alterations in lipid bilayer structures. Markers for epidermal differentiation (i.e. filaggrin, loricrin and involucrin) and terminal differentiation (i.e. TUNEL assay and caspase-14 activation) were respectively decreased and increased in CB1R and CB2R -/- mice. Surprisingly, CB1R agonist treatment of human cultured keratinocytes increases mRNA of p21 and cytokeratin 1 and 10 and decreases cyclin D1 but protein levels remained unchanged. Such paradox could partially be explained by the increase in non-phosphorylated-4E-BP1, an inhibitor of mRNA translation, following CB1R agonist treatment. Altogether, these observations put forward the importance and the complexity of cannabinoid signalling for the regulation of permeability barrier and epidermal differentiation.

Feeder layer- and animal product-free culture of neonatal foreskin keratinocytes: improved performance, usability, quality and safety.

Since 1987, keratinocytes have been cultured at the Queen Astrid Military Hospital. These keratinocytes have been used routinely as auto and allografts on more than 1,000 patients, primarily to accelerate the healing of burns and chronic wounds. Initially the method of Rheinwald and Green was used to prepare cultured epithelial autografts, starting from skin samples from burn patients and using animal-derived feeder layers and media containing animal-derived products. More recently we systematically optimised our production system to accommodate scientific advances and legal changes. An important step was the removal of the mouse fibroblast feeder layer from the cell culture system. Thereafter we introduced neonatal foreskin keratinocytes (NFK) as source of cultured epithelial allografts, which significantly increased the consistency and the reliability of our cell production. NFK master and working cell banks were established, which were extensively screened and characterised. An ISO 9001 certified Quality Management System (QMS) governs all aspects of testing, validation and traceability. Finally, as far as possible, animal components were systematically removed from the cell culture environment. Today, quality controlled allograft production batches are routine and, due to efficient cryopreservation, stocks are created for off-the-shelf use. These optimisations have significantly increased the performance, usability, quality and safety of our allografts. This paper describes, in detail, our current cryopreserved allograft production process.

Glycerol treatment as recovery procedure for cryopreserved human skin allografts positive for bacteria and fungi.

Human donor skin allografts are suitable and much used temporary biological (burn) wound dressings. They prepare the excised wound bed for final autografting and form an excellent substrate for revascularisation and for the formation of granulation tissue. Two preservation methods, glycerol preservation and cryopreservation, are commonly used by tissue banks for the long-term storage of skin grafts. The burn surgeons of the Queen Astrid Military Hospital preferentially use partly viable cryopreserved skin allografts. After mandatory 14-day bacterial and mycological culture, however, approximately 15% of the cryopreserved skin allografts cannot be released from quarantine because of positive culture. To maximize the use of our scarce and precious donor skin, we developed a glycerolisation-based recovery method for these culture positive cryopreserved allografts. The inactivation and preservation method, described in this paper, allowed for an efficient inactivation of the colonising bacteria and fungi, with the exception of spore-formers, and did not influence the structural and functional aspects of the skin allografts.

Hypnosis and alopecia areata: Long-term beneficial effects on psychological well-being.

Although there often exists important psychological comorbidity in patients with alopecia areata, few studies have investigated the role of psychotherapeutic interventions. The aim of this prospective cohort study was to investigate the long-term evolution of psychological symptoms in twenty-one patients with refractory alopecia areata. Patients received 10 individual sessions of hypnosis during an approximate 6-month period. Before treatment, patients presented a pathological psychological comorbidity. After treatment, a significant amelioration of alexithymia, anxiety, depression and mental well-being was observed. These improvements were maintained up to 6 months after the end of treatment. Important limitations of this study include the recruitment of highly motivated patients and a non-controlled study design. In summary, hypnotherapy may be effective for significantly improving and maintaining psychological well-being and quality of life in patients with refractory alopecia areata.

Potential release of aluminum and other metals by food-grade aluminum foil used for skin allograft cryo preservation.

Since 1991, the skin bank of the Queen Astrid Military Hospital uses food-grade aluminum foil as a primary support for storing cryo preserved human donor skin (511 donors). The possible release of heavy metals into the cryo preservation media (30% (v/v) glycerol in physiological water) and the possible impact this release could have on the quality of the cryo preserved donor skin was evaluated. Aluminum was the principal detection target. Possible contaminants of the aluminum foil as such (arsenic, cadmium, chromium and lead) were also investigated. The evaluation was set up after a Belgian Competent Authority inspection remark. Aluminum was detected at a concentration of 1.4 mg/l, arsenic and lead were not detected, while cadmium and chromium were detected in trace element quantities. An histological analysis revealed no differences between cryo preserved and fresh donor skin. No adverse reactions in patients, related to the presence of aluminum or heavy metal traces, were reported since the introduction of the cryo preserved donor skin in our burn wound centre.

Increased history of childhood and lifetime traumatic events among adults with alopecia areata.

BACKGROUND: Whether adult alopecia areata (AA) is associated with childhood or total lifetime traumatic events is not known. Previous studies have investigated only the relationship with recent stressful events. OBJECTIVE: We sought to determine whether patients with AA experience more childhood or total lifetime traumatic events, as measured by the Traumatic Experiences Checklist. METHODS: Using a case-control study, data on 90 patients with AA and 91 control subjects were analyzed. RESULTS: Significantly more patients with AA experienced total lifetime and early childhood traumatic events, with an odds ratio of 2.46 (95% confidence interval 1.15-5.28; P = .017) and 2.16 (1.15-4.06; P = .016), respectively. In patients with AA, the global impact score related to their traumatic experiences was significantly higher than in control subjects (P < .001). In addition, patients with AA experienced significantly more emotionally and physically traumatic events. LIMITATION: This case-control study is susceptible to recall bias and to confounding factors associated with stress caused by AA outbreaks or by a traumatic childhood history. CONCLUSION: Our study documents an increased history of childhood trauma in patients with AA compared with control subjects.

Clinical scoring and biophysical evaluation of nasolabial skin barrier damage caused by rhinorrhea.

BACKGROUND: An acute viral cold is a very common illness and is characterized by sneezing and a runny nose. Because of rhinorrhea and frequent use of handkerchiefs, the skin around the nose feels uncomfortably dry and flaky. OBJECTIVES/METHODS: To evaluate the nasolabial skin barrier impairment, 14 female volunteers with a common cold were recruited. Visually assessed clinical scoring and/or biophysical measurements--including transepidermal water loss, stratum corneum hydration, skin colour, squamometry, skin pH, and a skin surface lipid profile analysis--were carried out at the start of the cold, a second time when the severity of the cold symptoms was maximal, and finally when the volunteers felt healthy again and stopped using handkerchiefs. RESULTS AND CONCLUSIONS: Transepidermal water loss assessments showed significantly higher measurements on the maximum outcome of the nasal cold compared with the time-point when the symptoms of the cold had disappeared. This was in accordance with skin colour chroma a* measurements and the visually assessed skin erythema and scaliness scores, indicating that the superficial nasolabial skin barrier was inferior at the maximum of a nasal cold in comparison with the skin condition when volunteers were fully recovered.

Daily treatment with adapalene gel 0.1% maintains initial improvement of acne vulgaris previously treated with oral lymecycline.

Topical retinoids are often recommended for preventing acne recurrence, but there are relatively few well-controlled maintenance studies published. The objective of the present study was to assess the maintenance effect of adapalene gel 0.1% relative to gel vehicle in subjects successfully treated in a previous 12-week adapalene-lymecycline 300 mg combination therapy study. This was a multicentre, investigator-blind, randomised, controlled study in 19 European centres. A total of 136 subjects with moderate to moderately-severe acne vulgaris who showed at least moderate improvement from baseline when treated with either adapalene plus lymecycline or lymecycline plus gel vehicle in a previous 12 week study were included. Subjects were randomised to receive adapalene gel 0.1% or vehicle once-daily for 12 weeks. Efficacy and safety criteria included maintenance rate, percent reduction in lesion counts (total, inflammatory, non inflammatory), global severity assessment, cutaneous tolerability, and adverse events. Adapalene provided better results relative to gel vehicle for all efficacy assessments. The maintenance rate for total lesions was 84.7% vs. 63.5% (P = 0.0049) with adapalene and the vehicle, respectively. Adapalene was safe and well tolerated in this study. This study demonstrates a clinical benefit of continued treatment with adapalene gel 0.1% as a maintenance therapy for acne.

Serine protease activity and residual LEKTI expression determine phenotype in Netherton syndrome.

Mutations in the SPINK5 gene encoding the serine protease (SP) inhibitor, lymphoepithelial-Kazal-type 5 inhibitor (LEKTI), cause Netherton syndrome (NS), a life-threatening disease, owing to proteolysis of the stratum corneum (SC). We assessed here the basis for phenotypic variations in nine patients with "mild", "moderate", and "severe" NS. The magnitude of SP activation correlated with both the barrier defect and clinical severity, and inversely with residual LEKTI expression. LEKTI co-localizes within the SC with kallikreins 5 and 7 and inhibits both SP. The permeability barrier abnormality in NS was further linked to SC thinning and proteolysis of two lipid hydrolases (beta-glucocerebrosidase and acidic sphingomyelinase), with resultant disorganization of extracellular lamellar membranes. SC attenuation correlated with phenotype-dependent, SP activation, and loss of corneodesmosomes, owing to desmoglein (DSG)1 and desmocollin (DSC)1 degradation. Although excess SP activity extended into the nucleated layers in NS, degrading desmosomal mid-line structures with loss of DSG1/DSC1, the integrity of the nucleated epidermis appears to be maintained by compensatory upregulation of DSG3/DSC3. Maintenance of sufficient permeability barrier function for survival correlated with a compensatory acceleration of lamellar body secretion, providing a partial permeability barrier in NS. These studies provide a mechanistic basis for phenotypic variations in NS, and describe compensatory mechanisms that permit survival of NS patients in the face of unrelenting SP attack.

Hypnotherapeutic management of alopecia areata.

BACKGROUND: Only limited data exist on the role of psychotherapy in alopecia areata (AA). OBJECTIVE: We sought to document the influence of hypnotherapy on psychologic well-being and clinical outcome in AA. METHODS: Hypnosis was used in 28 patients with extensive AA who were refractory to previous conventional treatments. It was added as a complementary treatment or used as the only treatment. RESULTS: In all, 21 patients, 9 with alopecia totalis or alopecia universalis and 12 with extensive AA, were analyzed during a 5-year period. After treatment, all patients had a significantly lower score for anxiety and depression. Scalp hair growth of 75% to 100% was seen in 12 patients after 3 to 8 sessions of hypnotherapy. Total growth occurred in 9 of these 12 patients, including 4 patients with alopecia universalis and 2 with ophiasis. In 5 patients, a significant relapse occurred. LIMITATIONS: This is a preliminary study with a limited number of patients. A larger randomized study is necessary. CONCLUSION: Hypnotherapy may enhance the mental well-being of patients with AA and it may improve clinical outcome.

Sustained serine proteases activity by prolonged increase in pH leads to degradation of lipid processing enzymes and profound alterations of barrier function and stratum corneum integrity.

We showed recently that short-term increases in stratum corneum (SC) pH are accompanied by minor alterations in permeability barrier homeostasis and SC integrity/cohesion. Since prolonged SC neutralization more closely mirrors clinical situations (i.e., neonatal skin, occupational dermatitis conditions), we assessed here whether sustained elevations of SC pH by long-term application of 1,1,3,3-tetramethylguanidine superbase provoke profound alterations in SC function. Sustained SC neutralization altered not only barrier recovery kinetics but also basal permeability barrier function. These abnormalities were attributable to a decrease in beta-glucocerebrosidase (beta-GlcCer'ase) and acidic sphingomyelinase (aSMase) catalytic activity and enzyme degradation consequent to a pH-induced sustained serine protease (SP) activity. The role of SP in this process was shown by the normalization of enzyme activities/content by co-applied SP inhibitors (SPI). To address whether lipid-processing enzymes are potential substrates for the stratum corneum chymotryptic enzyme (SCCE), protein extracts from human SC were treated for 2 h at 37 degrees C with recombinant active SCCE at pH 7.2. Recombinant SCCE induced a significant decrease in the immunoblotting of both beta-GlcCer'ase or aSMase compared with control experiments performed in the absence of the active SCCE. Finally, with sustained SC neutralization, SC integrity/cohesion deteriorated, attributable to SP-mediated degradation of corneodesmosomes (CD) as well as CD constituent proteins, desmoglein 1. These abnormalities were again reversed by co-applied SPI. In conclusion, prolonged SC neutralization provokes profound abnormalities in SC function, due to pH-induced high SP activity that, in turn, degrades lipid processing enzymes and CD proteins.

Curettage of giant congenital melanocytic nevi in neonates: a decade later.

BACKGROUND: Currently, there is tremendous uncertainty regarding how giant congenital melanocytic nevi (GCMN) should be treated. Our approach to patients with GCMN is based on 2 main considerations: (1) obtain an acceptable cosmetic result to decrease the psychosocial inconvenience to the patient, and (2) attempt to minimize the risk of malignancy. For the past 10 years we have treated GCMN by curettage in the neonatal period. We report our experience and results. OBSERVATIONS: Sixteen neonates with GCMN were treated by curettage between 1990 and 2000. Biopsy specimens were obtained and the patients received close clinical follow-up. In most patients cosmetic and functional results were good, and, to date, no melanoma has been observed in this series. CONCLUSIONS: Curettage offers an adequate alternative to surgical excision when performed during the first 2 weeks of life. Patients and parents are pleased with the cosmetic and functional results and thereby suffer less from the psychosocial inconvenience caused by these lesions. Careful long-term follow-up of these children is essential to monitor final cosmetic outcome and reduce the potential for malignancy.

A phase II multicenter clinical trial of systemic bexarotene in psoriasis.

BACKGROUND: Bexarotene, a novel and unique synthetic P, RXR-selective retinoid, is available as a treatment for cutaneous T-cell lymphoma. In psoriasis, a common retinoid-sensitive disease, no data are available on bexarotene treatment. OBJECTIVE: In this phase II study we investigated the safety, tolerability, and effectiveness of bexarotene in psoriasis at doses of 0.5 to 3.0 mg/kg/day. METHODS: Fifty patients with moderate to severe plaque-type psoriasis were treated with bexarotene in 4 sequential dose-defined panels of 12-13 patients at doses of 1.0, 2.0, 0.5, and 3.0 mg/kg/day for 12-24 weeks. Patients were monitored for safety and clinical efficacy. RESULTS: No serious adverse events related to the drug occurred. Bexarotene was well tolerated in most patients. Most frequently observed adverse events related to bexarotene were hypertriglyceridaemia (56%) and a decrease in free T4 serum levels (54%). Significant improvement of psoriasis after bexarotene at all doses was confirmed by a modified psoriasis area and severity index (mPASI), plaque elevation (PEL), and physician's global assessment (PGA). Overall response rates (> or =50% improvement) for mPASI, PEL, and PGA were 22%, 52%, and 36%, respectively. No significant dose-response effect was established for these parameters. CONCLUSION: The present study indicates an anti-psoriatic effect of bexarotene. Further studies are necessary to assess the optimal dose and the potential for bexarotene as a new therapy for psoriasis.

The effect of two moisturisers on skin barrier damage in allergic contact dermatitis.

Nickel (Ni)-induced allergic contact dermatitis (ACD) was performed in human volunteers to study the role of moisturisers in preventing ACD-related skin barrier damage. 15 Ni-sensitive females (mean age: 29.5 years; range: 23-38) were included. On days 1, 21, 24 and 26, TEWL, stratum corneum (SC)-capacitance and clinical score were evaluated on four test sites on the right and left forearms. Both a highly and a poorly hydrating moisturising formulation were applied on two sites from days 1 to 21, after which Ni-ACD was induced on the 2 pre-treated sites and one non-treated area. On day 24, TEWL values were significantly increased on the site pre-treated with poorly hydrating product compared to the rich formulation pre-treated site. SC-hydration was significantly improved on the latter site on days 21, 23 and 26. Long-term use of inadequate moisturiser increases skin barrier damage due to Ni-ACD.

Safety and efficacy of combined use of 4-hydroxyanisole (mequinol) 2%/tretinoin 0.01% solution and sunscreen in solar lentigines.

The objective of this open-label, noncontrolled study was to evaluate the safety of a combination solution containing 4-hydroxyanisole (mequinol) 2%/tretinoin 0.01% (Solagé) with a sunscreen in the treatment of solar lentigines. The study included a total of 406 subjects for a treatment period up to 24 weeks. Efficacy was evaluated clinically by grading the pigmentation level of the treated areas on the face and forearms. A total of 378 subjects were included in the safety population. Of the 173 subjects with skin-related and treatment-related adverse events, severity was reported as mild in 79 subjects, moderate in 71, and severe in 23. Hypopigmentation was observed in 4 subjects and had definitively resolved in 3 of these subjects at the end of the study or after treatment had been discontinued. Halo hypopigmentation was reported in 16 subjects. No allergic reactions were observed. Efficacy evaluation was based on data for 370 subjects. A total of 325 (88%) subjects had facial target lesions almost clear to clear, and a total of 298 (81%) subjects had forearm target lesions almost clear to clear. Our study shows that the mequinol 2%/tretinoin 0.01% solution is effective, convenient, and safe in the treatment of solar lentigines.

Management of scars: updated practical guidelines and use of silicones.

Hypertrophic scars and keloids resulting from surgery, burns, trauma and infection can be associated with substantial physical and psychological distress. Various non-invasive and invasive options are currently available for the prevention and treatment of these scars. Recently, an international multidisciplinary group of 24 experts on scar management (dermatologists; plastic and reconstructive surgeons; general surgeons; physical medicine, rehabilitation and burns specialists; psychosocial and behavioural researchers; epidemiologists; beauticians) convened to update a set of practical guidelines for the prevention and treatment of hypertrophic and keloid scars on the basis of the latest published clinical evidence on existing scar management options. Silicone-based products such as sheets and gels are recommended as the gold standard, first-line, non-invasive option for both the prevention and treatment of scars. Other general scar preventative measures include avoiding sun exposure, compression therapy, taping and the use of moisturisers. Invasive treatment options include intralesional injections of corticosteroids and/or 5-fluorouracil, cryotherapy, radiotherapy, laser therapy and surgical excision. All of these options may be used alone or as part of combination therapy. Of utmost importance is the regular re-evaluation of patients every four to eight weeks to evaluate whether additional treatment is warranted. The amount of scar management measures that are applied to each wound depends on the patient's risk of developing a scar and their level of concern about the scar's appearance. The practical advice presented in the current guidelines should be combined with clinical judgement when deciding on the most appropriate scar management measures for an individual patient.

Sunscreen use and skin protection behaviour on the Belgian beach: a comparison 9 years later.

Public health campaigns encourage people to protect themselves against skin cancer by using sunscreens and taking other protective measures. The objective is to estimate the impact of these campaigns on the rise of awareness among the general public. This study explores the prevalence and predictors of solar protection behaviour in a sample of beachgoers and compares these results to another similar study carried out 9 years earlier (i.e. summer 2001). During the month of August 2010, a total of 408 participants (144 men and 264 women) were randomly selected on their way to the Belgian beach in the city of Ostend, Belgium. The solar protection behaviour of each participant was assessed by direct observation and an interview. The exact same questions were asked as in 2001. The general risk awareness stays the same for skin aging and skin cancer but gets higher for sunburn. When we control these results for sex, the overall higher general awareness is completely because of the higher awareness of the female subgroup. As in 2001, risk awareness is considerably higher in the female subgroup than in the male one. As in 2001, sunscreen cream was the most popular preventive behaviour in 2010 (use of sunscreen with sun protection factor 15 or higher reported by 66.4%), followed by timed sun exposure (46.8%), use of clothing and hats (36.8%) and shade (34.1%). As in summer 2001 the sunscreen use is more popular in the female population. The use of protective clothing and hats is more popular in the male group. As solar protection has become part of the beach behaviour routine, there is room for improvement for their more frequent application, the use of a higher sun protection factor (15+), timed sunbathing, more use of clothing and hats and seeking shade. The results of this study can assist in evaluating the effectiveness of present sun-protection campaigns and health education programmes.

Actin dynamics regulate immediate PAR-2-dependent responses to acute epidermal permeability barrier abrogation.

BACKGROUND: Lamellar body (LB) secretion and terminal differentiation of stratum granulosum (SG) cells are signaled by both protease activated receptor-2 (PAR-2) and caveolin-1 (cav-1). OBJECTIVE: To address the early dynamics of LB secretion, we examined cytoskeletal remodeling of keratinocytes in 3 mouse models following acute barrier abrogation: hairless mice, PAR-2 knockout (-/-) and cav-1 -/-. METHODS AND RESULTS: Under basal conditions, globular (G)-actin accumulates in SG cells cytosol, while filamentous (F)-actin is restricted to peri-membrane domains. Barrier abrogation induces the apical movement of F-actin and the retreat of the SG-G-actin front, paralleled by upstream cytoskeletal kinases activation. This phenomenon was both enhanced by PAR-2 agonist, and inhibited by cytochalasin-D and in PAR-2 knockout mice. We found that plasma membrane conformational changes causing LB secretion are controlled by PAR-2-dependent cytoskeletal rearrangements. We next addressed the interaction dynamics between cytoskeleton and plasma membrane following PAR-2-induced actin stress fiber formation in both cav-1 -/- and wildtype cells. Actin stress fiber formation is increased in cav-1 -/- cells prior to and following PAR-2 agonist peptide-treatment, while absence of cav-1 inhibits E-cadherin-mediated cell-to-cell adhesion. CONCLUSION: PAR-2 drives cytoskeletal/plasma membrane dynamics that regulate early LB secretion following barrier abrogation, stress fiber formation and keratinocyte adhesion.

Acute acidification of stratum corneum membrane domains using polyhydroxyl acids improves lipid processing and inhibits degradation of corneodesmosomes.

Neutralization of the normally acidic stratum corneum (SC) has deleterious consequences for permeability barrier homeostasis and SC integrity/cohesion attributable to serine proteases (SPs) activation leading to deactivation/degradation of lipid-processing enzymes and corneodesmosomes (CD). As an elevated pH compromises SC structure and function, we asked here whether SC hyperacidification would improve the structure and function. We lowered the pH of mouse SC using two polyhydroxyl acids (PHA), lactobionic acid (LBA), or gluconolactone (GL). Applications of the PHA reduced the pH at all levels of SC of hairless mouse, with further selective acidification of SC membrane domains, as shown by fluorescence lifetime imaging. Hyperacidification improved permeability barrier homeostasis, attributable to increased activities of two key membrane-localized, ceramide-generating hydrolytic enzymes (beta-glucocerebrosidase and acidic sphingomyelinase), which correlated with accelerated extracellular maturation of SC lamellar membranes. Hyperacidification generated "supernormal" SC integrity/cohesion, attributable to an SP-dependent decreased degradation of desmoglein-1 (DSG1) and the induction of DSG3 expression in lower SC. As SC hyperacidification improves the structure and function, even of normal epidermis, these studies lay the groundwork for an assessment of the potential utility of SC acidification as a therapeutic strategy for inflammatory dermatoses, characterized by abnormalities in barrier function, cohesion, and surface pH.