[Solar protection products: efficacy and risks]. / Produits de protection solaire : efficacité et risques.

Solar protection products (SPP) containing chemical filters and/or mineral filters are extensively used today in photoprotection; however, concerns continue to be voiced about their efficacy and about their possible dangers. A rapid review of photoprotection strategies shows that SPP owe their photoprotective effect to the absence of other photoprotection methods having clearly established efficacy in healthy subjects; in addition, they exhibit real protective efficacy against the majority of harmful effects of solar radiation, provided they have been devised in keeping with the specifications clearly set out in the recommendations of the French Medicines Agency (Afssaps). Such efficacy is dependent on their correct usage, recently reiterated by Afssaps in its recommendations to end-users concerning the good use of solar products: application of adequate quantities of such products, selection of the appropriate photoprotection class based on phototype and conditions of exposure, and regular renewal of applications in the event of prolonged exposure and after bathing or profuse sweating. Solar filters have long been known to cause contact allergic dermatitis, irritative dermatitis and photosensitisation, and a particular risk has appeared with the use of octocrylene. However, debate has centred primarily on the risk of endocrine disturbance potentially induced by chemical filters, certain of which exhibit established transcutaneous penetration. The risk of mimicry of an effect of oestradiol has been raised on the basis of a series of studies, almost all of which were carried out by the same team, and which mainly concerned 4-methylbenzylidene-camphor (4-MBC) following oral absorption in the rat. The risk of this type of effect with SPPs under normal conditions of use seems fairly remote according to the current state of knowledge; in any event, within the context of the "National Fertility Action Plan", Afssaps has been formally requested to analyse the risk associated with cosmetic substances that are "reprotoxic" and/or affect endocrine function, as a result of which various filters are currently being reassessed for such risk. The greater alleged safety of mineral filters, based on the absence of introduction of risk of photosensitisation (as a result of which they are preferred for use in young children), no longer seems so clear since the introduction of titanium dioxide (TiO2) and zinc oxide (ZnO) in the form of nanoparticles. Afssaps drew up a risk assessment report concerning cutaneous penetration, genotoxicity and oncogenesis for TiO(2) and ZnO in nanoparticle form; further studies are needed before any general conclusions may be drawn. The European Scientific Committee on Consumer Safety (SCCS) is also carrying out an evaluation of the use of TiO(2) and of ZnO as UV filters. Finally, current data do not suggest that SPPs exert any harmful effects by inhibiting the beneficial effects of the sun, in particular, vitamin D synthesis.

[Narrow-band UVB therapy in psoriasis vulgaris: good practice guideline and recommendations of the French Society of Photodermatology]. / La photothérapie UVB à spectre étroit dans le psoriasis vulgaire : utilisation pratique et préconisations de la Société Française de Photodermatologie.

BACKGROUND: Phototherapy, PUVA therapy and narrow-band UVB are recognised forms of first-line therapy for extensive and severe plaque psoriasis. Based on a systematic review of the medical literature, we propose a good practice guideline for the use of narrow-band UVB phototherapy in this indication. METHODS: We carried out a review of the literature published over the 20 years (1998 to 2009) in the online PubMed database. Our conclusions are based on the results of control studies or where these are absent, on a synthesis of the recommendations common practice approved by the experts of the French Society of Photodermatology. The levels of scientific proof given are based on the criteria defined by Sackett. RESULTS RECOMMENDATIONS: (1) Practical aspects. Irradiation cabins equipped with Philips TL01 tubes, either for monotherapy (42 tubes) or for combined therapy (21 UVB tubes and 21 UVA tubes), were to be certified (CE marking, ISO-DIN certification) and equipped with an accurate dosimetry system. Several valid and usable protocols exist. The indication was based on the severity and extent of the episode of psoriasis, the psychological consequences of the dermatosis, comparison of the benefit/risk ratios of the various available treatments, the ability of the patient to attend sessions (a vital factor in therapeutic compliance), the cumulative doses of UV from previous courses of treatment, and absence of contraindications, including the use of photosensitising medication. Informed consent was to be obtained from patients, who were given a validated information sheet (available at www.sfdermato.org). The study results and the value of maintenance therapy were not confirmed. (2) Adverse effects. The immediate adverse effects were generally of little consequence, with later effects alone posing problems. Because of the risk of induction of cataract, ocular protection must be used during sessions. In the absence of symptoms or known ocular disorder, prior ophthalmologic control is not considered necessary. The risk of skin cancer remains poorly defined, and this risk has not been clearly shown to be lower than with broad-spectrum UVB therapy or PUVA. The studies give no indication of the number of sessions after which therapy must be completely discontinued. In the absence of clear evaluation of oncogenic risk, it seems reasonable to set the maximum number of sessions of UVB TL01 phototherapy at 250 as with PUVA, and to include in this limit the total of all PUVA and TL01 phototherapy sessions for patients receiving both types of phototherapy (level of proof: B). In the absence of lesions requiring treatment in these areas, the face and male genital organs should be protected during treatment sessions. There is no currently available data concerning carcinogenic risk induced by TL01 in patients also on cyclosporine, methotrexate or biotherapies. In order to reduce risk and maintain patients' capacity to undergo further phototherapy sessions, we suggest (level of proof: A) the following measures: strict patient selection, use of combined synergistic therapies, annual examination of the skin and appendages of subjects receiving more than 150 phototherapy sessions, and the creation of nationally accessible patient phototherapy files. (3) Combined treatments. The purpose of such treatment is twofold: to reduce the risk of adverse effects while increasing the efficacy of TL01 phototherapy. Lesions should be sloughed before the start of phototherapy. Synergistic effects have been demonstrated for dermal corticosteroids and tazarotene, but such effects are less noticeable with topical vitamin D3 derivatives. If there are no contraindications to its prescription, we feel that acitretine has demonstrated efficacy in enhancing the effect of TL01 phototherapy. (4) Efficacy. Narrow-spectrum UVB phototherapy is considered highly effective in extensive psoriasis. At a rate of three sessions per week, it results in complete (or almost complete) eradication of lesions in 60 to 90 % of patients within 20 to 40 sessions (level of proof: A). However, the efficacy of this therapy varies according to plaque size and noticeably better results are obtained in guttate and nummular psoriasis than in psoriasis involving large plaques. CONCLUSION: Narrow-spectrum UVB phototherapy offers a good alternative to PUVA therapy since concomitant psoralen is not required, but there are few immediate adverse effects, there is less risk of drug-induced photosensitisation, and there is no need for skin or ocular photoprotection after sessions. We recommend this approach as the first-line phototherapy (level of proof: A) in children and adolescents, and in adults with extensive moderate psoriasis involving small superficial plaques. It may also be used in pregnant or breastfeeding women and in patients with renal or hepatic insufficiency. In addition, it is preferable for HIV-positive subjects (level of proof: C). However, PUVA therapy is preferable as first-line treatment in extensive severe psoriasis involving large thick plaques (level of proof: A) and in adults of phototypes IV to VI (level of proof: B); it should also be contemplated for psoriasis refractory to UVB TL01 (level of proof: B).

Multiple aggressive squamous cell carcinomas associated with prolonged voriconazole therapy in four immunocompromised patients.

Rare squamous cell carcinoma (SCC) cases associated with voriconazole therapy have been reported, but this risk may not receive enough consideration from clinicians. We describe four patients presenting with multiple SCC while receiving prolonged (two to three years) voriconazole therapy. Three patients had underwent lung transplantation. SCC were preceded by photosensitization lesions, and predominated in photoexposed area, particularly the face. Therapy associated surgery, chemotherapy in one case, and voriconazole discontinuation; replacement by posaconazole or itraconazole did not trigger other photosensitive lesions. Once voriconazole withdrawn, preneoplastic lesions regressed. In conclusion, prolonged voriconazole therapy may enhance the risk of photoinduced SCC in immunocompromised patients, and skin monitoring is mandatory.

[Two cases of iatrogenic cutis and subcutis calcinosis after calcium-containing heparin injection]. / Calcinose cutanée et sous-cutanée après injection d'héparine calcique : à propos de deux cas.

BACKGROUND: Subcutis calcinosis, characterized by abnormal calcium deposition in the skin, is a rare side effect of calcium containing heparins. PATIENTS AND METHODS: Two patients with renal failure presented skin lesions after receiving a calcium-containing heparin treatment. The first patient exhibited erythematous nodules on the abdomen and the second a large erythematous induration of the abdomen and nodules on the thighs. Both had normal blood analysis. The diagnosis of subcutis calcinosis was confirmed by the histological exam showing calcium deposit in the dermis and hypodermis. Outcome was unfavourable in one of the patients who developed a superinfection and skin necrosis lesion requiring surgery at 2 months. DISCUSSION: Subcutis calcinosis is a rare and probably underdiagnosed disease. To our knowledge, only 10 cases have been reported. The pathogenesis is not well-known, tissue damage and calcium disorders are considered as risk factors. The differential diagnoses that can be suspected include calciphylaxis, such as calcifying panniculitis and other local side effects of heparins. Outcome is usually favourable without treatment. CONCLUSION: We describe two cases of iatrogenic subcutis calcinosis after injections of calcium-containing heparins, including the second case of poor outcome. Clinicians should be aware of this adverse effect since other heparins such as fondaparinux or low-weight molecular heparins are contraindicated in patients with renal failure, leading to a large prescription of calcium-containing heparins in this population.

[Febrile cellulitis surrounding a scar revealing a large immunoblastic B-cell lymphoma]. / Dermohypodermite fébrile péricicatricielle révélatrice d'un lymphome B immunoblastique à grandes cellules.

BACKGROUND: Secondary skin sites of lymphoma appear in the advanced stages of the disease. We report the first case of a pericicatricial skin infiltration, mimicking febrile dermohypodermitis, revealing diffuse immunoblastic large B-cell non-Hodgkin's lymphoma. PATIENTS AND METHODS: Four months after decompressive cervical laminectomy, a 56-year-old man presented an inflammatory pericicatricial patch evoking cellulitis in a setting of hyperthermia and lymphadenopathy. Blood cultures and bacteriological analysis of skin biopsy samples were negative. The images showed infiltration of the soft subcutaneous areas and polyadenopathy. Two weeks later, several subcutaneous nodules appeared on the trunk. Histological analysis and immunolabelling pointed to immunoblastic large B-cell non-Hodgkin's lymphoma. A clone of B lymphocytes CD45+, CD20+, CD79a+, Bcl2+, CD5+, MUM1+, CD3-, CD10-, CD23- and Bcl6- was seen. The remainder of the extension examination was negative. CHOP-rituximab polychemotherapy resulted in complete regression of all lesions, notably the inflammatory cervical plaque. DISCUSSION: Secondary skin manifestations of lymphoma are generally non-specific (pruritus, ichthyosis, purpura, etc.) rather than specific in terms of lymphoid infiltration. As in our patient, certain cutaneous sites of lymphoma may have a misleading clinical presentation, histological analysis alone was able to provide a conclusive diagnosis. In our patient, the highly specific infiltration seen around the entire scar could either suggest a Koebner phenomenon or point to a role of the cutaneous aggression within the development of an inflammatory process contributing to pericicatricial infiltration by lymphoid cells. Locoregional invasion from the osseous part of the cervical spine and not macroscopically diagnosed during neurosurgery could also be responsible.

[Syringotropic and pilotropic cutaneous T-cell lymphoma without follicular mucinosis]. / Mycosis fongoïde syringotrope et pilotrope sans mucinose folliculaire.

BACKGROUND: Mycosis fongoides rarely exhibits predilection for infiltration of hair follicles and eccrine glands. We report the case of a patient with cutaneous T-cell lymphoma with syringotropism and pilotropism without follicular mucinosis. CASE REPORT: A 51-year-old man presented with erythematous infiltrated patches with alopecia and anhydrosis, cystic lesions, comedon-like lesions, follicular keratosis and an ulcer over the lower left leg. Clinical examination revealed no palpable adenopathy or hepatosplenomegaly. The patient complained about hypohydrosis. Histological examination of skin biopsies evidenced pilotropic cutaneous T-cell lymphoma without follicular mucinosis. Immunohistological examination and T-cell receptor B-chain gene rearrangement analysis showed a clonal population of T-cells. Moreover sweat glands and sweat ducts were infiltrated by atypical lymphocytes with syringolymphoid hyperplasia. DISCUSSION: Syringolymphoid hyperplasia and folliculotropism without follicular mucinosis are rarely seen in mycosis fongoides. Deep biopsies of adnexal structures are required for this critical diagnosis and clonal rearrangement of TCR genes is a reliable means of assessing clonality. Syringolymphoid hyperplasia and pilotropism without mucinosis are variants of cutaneous T-cell lymphomas.

[Dermatologic follow-up and evaluation of skin tumours in renal transplant patients]. / Evaluation du suivi dermatologique et des tumeurs cutanées chez les greffés rénaux.

BACKGROUND: Renal transplant patients are at increased risk for warts, actinic keratoses and carcinomas. A descriptive study was conducted to investigate the number and frequency of dermatologic examinations in renal transplant patients with a functional graft. The incidence and clinical factors for skin tumours were also assessed. PATIENTS AND METHODS: We sent an initial questionnaire to 686 renal transplant patients asking whether they had consulted a dermatologist since the time of transplantation. A second questionnaire was then sent to private dermatologists in order to evaluate dermatologic follow-up and the frequency and anatomic distribution of warts and cancerous skin lesions. At the same time, the patients' medical records at the hospital were studied. RESULTS: About two thirds of the 436 patients included in the study have seen a dermatologist at least once since the time of transplantation. Only 31.2% are being followed up regularly by a dermatologist. The incidence of warts and actinic keratoses is 48.8% and 20.6% respectively, and increases with the duration of immunosuppressive therapy. The incidence of carcinomas is 20.2%, with basal cell carcinomas being seen more frequently than other carcinomas. Risk factors identified for carcinomas are older age at transplantation, duration of immunosuppressive therapy, fair skin, presence of warts and actinic keratoses. All these skin lesions arise predominantly on highly sun-exposed surfaces. Nevertheless, squamous cell carcinomas are more often confined to sun-exposed skin than Bowen's diseases and basal cell carcinomas. DISCUSSION: Dermatologic follow-up of transplant recipients has rarely been investigated and our study shows that monitoring of skin cancer is probably inadequate. It also confirms the high incidence of carcinomas among renal-transplant recipients in a temperate climate, although basal cell carcinomas are more frequent than squamous cell carcinomas.

[Thrombosis of legs arteries: imputability of anti-phosphatidylethanolamine antibodies?]. / Thromboses artérielles des membres inférieurs: responsabilité des anticorps antiphosphatidyléthanolamine?

BACKGROUND: At the beginning the antiphospholipid antibodies syndrome was associated with systemic lupus erythematosus. But since 1988 it has become a sole entity. Its current definition is based on the criteria established in 1999 by Sapporo and consists of associating the clinical criteria of thrombosis of arteries or peripheral veins and of miscarriage of pregnancy with the biological criteria. Either anti-cardiolipin antibodies or lupus anticoagulant must be present. Anti-phosphatidylethanolamine antibodies are not included in the Sapporo criteria. CASE REPORT: A non smoking, 43 year-old man showed a clinical manifestation of livedo on the thighs, and left knee and foot, associated with a rapidly extending cutaneous necrosis on the left toes. One year earlier his right leg was amputated up to half of the calf following distal gangrene. The gangrene was consecutive to a stent implantation after a significant stenosis of the right superficial femoral artery. The etiological investigations revealed neither thrombophily nor cholesterol embolism nor vasculitis. No sign of underlying neoplasia could be found. These clinical symptoms as well as the anamnesis were strongly suggestive of an antiphospholipid antibodies syndrome. The immunological dosages revealed isolated positive anti-phosphatidylethanolamine antibodies, persistent six weeks later. DISCUSSION: Several cases of clinical manifestations of the antiphospholipid antibodies syndrome have been described, without any anti-cardiolipin antibodies or lupus anticoagulant, but with presence of anti-phosphatidylethanolamine antibodies. In cases of these strong evocative symptoms but no evidence of the classical biological Sapporo criteria, these antibodies should be systematically searched for.

[Skin cancer and psoralen plus UVA: a retrospective study of 106 patients exposed to a great number of PUVA treatments]. / PUVAthérapie et cancers cutanés: etude rétrospective chez 106 malades ayant reçu des doses élevées de PUVA.

INTRODUCTION: The benefits of PUVAtherapy in many dermatological affections are well known. Its carcinogenic role in the long term has been assessed varyingly in American and European series. OBJECTIVE: The aim of this study was to assess the role of PUVA in the onset of cancers of the skin. METHODS: Retrospective study of patients presenting with psoriasis and followed-up in the phototherapy unit of the Michallon Hospital in Grenoble since 1976 and having received more than 150 sessions of PUVA. The parameters studied were: age, gender, phototype, age at the time of the first irradiation, type of phototherapy administered, total number of sessions, concomitant treatments, administration of retinoids and the appearance of skin cancers with the interval before their onset after the first session, their localization and their histological type. RESULTS: One hundred six patients were retained among the 152 who replied to the inclusion criteria. Having died or been lost to follow-up, forty-six patients were excluded. Fourteen patients had presented at least one cutaneous tumor with a total number of 35. Excluding the keratoacanthomas, 13 patients had a non-melanic cutaneous cancer with a total number of 32 tumors. Ten out of the 14 were phototype III, 3 were phototype II and one was phototype IV. Nine out of 14 had received PUVAtherapy alone and 5 PUVAtherapy and broad spectrum UVB. The number of sessions of PUVA received in all the cases was more than 200 (220 to 780), corresponding to a total dose of UVA comprised between 1460 and 3882 Joules. The delay before onset of the tumors varied from 6 to 27 years after the first PUVAtherapy. The mean age at the time of the first irradiation was of 50.2 years (14-75 years). The mean duration of phototherapy was of 10 years (2.23 years).

Induction of thioredoxin by ultraviolet-A radiation prevents oxidative-mediated cell death in human skin fibroblasts.

The present study analyzes the expression of the thioredoxin/thioredoxin reductase (Trx/TR) system in UVA-irradiated human skin fibroblasts. Irradiation increases the intracellular level of Trx and a time-dependent increase of Trx mRNA is observed. Our data indicate that Trx translocates from the cytoplasm to the nucleus. In addition, UV exposure results in an increase in TR synthesis. In order to evaluate the function of Trx/TR system, we investigated the antioxidant role of Trx in transient transfected cells. The ROS accumulation in UVA irradiated cells was assessed using flow cytometry. A 3-fold decrease in ROS production was observed in transiently transfected fibroblasts. These results indicate that Trx acts as an antioxidant protein in UVA irradiated fibroblasts. As ROS are inducers of cell death, this raises the question as to whether Trx is able to protect cells from apoptosis and/or necrosis induced by UVA. Six hours after UVA-irradiation, 29.92% of cells were annexin-V positive. This population was significantly reduced in Trx-transfected cells (8.58%). Moreover, this work demonstrates that Trx prevents the loss of the membrane potential of the mitochondria, the depletion of cellular ATP content, and the loss of cell viability induced by irradiation.

Modulation of exogenous and endogenous levels of thioredoxin in human skin fibroblasts prevents DNA damaging effect of ultraviolet A radiation.

Thioredoxin (Trx) plays important biological roles both intra- and extracellularly via thiol redox control. We have previously demonstrated that Trx exhibited protective effects against UVA cytotoxicity in human skin fibroblasts. As an extension of the latter investigation, the present work is aimed at assessing ability of Trx to maintain genomic integrity in human skin fibroblasts upon exposure to UVA radiation. Indeed, UVA (320--380 nm) is mutagenic and induces genomic damage to skin cells. The alkaline comet assay was used in association with DNA repair enzyme including formamido pyrimidine glycosylase (Fpg) and endonuclease III (endo III) to estimate the amount of modified bases together with the level of strand breaks and alkali-labile sites. The HPLC-EC assay was applied to assess 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels and to permit the calibration of comet assay as previously described. We reported that overexpression of human Trx (transient transfection) as well as exogenous human recombinant Trx added to the culture medium, decreased the level of DNA damage in UVA irradiated cells. Interestingly, transfection appeared to prevent UVA-induced 8-oxodGuo (3.06 au per Joules.cm(-2) compared to 4.94 au per Joules.cm(-2) for nontransfected cells). Moreover, Trx accumulates into nuclei in transfected cells. This finding supports the notion that Trx is important for the maintenance of the integrity of genetic information. This work demonstrated that under conditions of UVA oxidative stress, Trx prevented the UVA-induced DNA damage.

[Enhancement of endogenous antioxidant defenses: a promising strategy for prevention of skin cancers]. / L'amélioration de la défense antioxydante endogène: une piste pour la prévention des cancers cutanés.

There is considerable evidence that ultraviolet radiation (UV) from sunlight is implicated in skin carcinogenesis. So the risks of cutaneous cancer have increased during the last decade due to increase of sun exposure. For a long time, ultraviolet B radiation (UVB: 290-320 nm) have been considered to be the more efficient wavelength in eliciting carcinogenesis in human skin. It is today clear that UVA (320-400 nm), especially UVA1 (340-400 nm) also participate to photo carcinogenesis. One of molecular mechanisms in the biological effects of UV is the induction of reactive oxygen species (ROS) directly or through endogenous photosensitization reactions. UVA radiation mainly acts via this production of ROS and the subsequent oxidative stress seems to play a crucial role in the deleterious effects of UVA. Fortunately, the skin possesses a wide range of interlinked antioxidant defence mechanism to protect itself from damage by UV-induced ROS. However, the capacity of these systems is not unlimited; they can be overwhelmed by excessive exposure to UV and then ROS can reach damaging levels. An interesting strategy to provide photoprotection would be to support or enhance one or more of these endogenous systems. In our experiments, we have evaluated the protective effect of glutathion, selenium and zinc, three compounds playing a pivotal role in the cellular defence against oxidative damage. We have irradiated both by UVA1 and UVB culture of human normal skin fibroblasts or of spontaneously immortalised human keratinocyte cell line Hacat. Before irradiation, treated cells were submitted to zinc deprivation by a diffusible zinc chelator, NNN' N'-tetrakis (2-pyridylmethyl) ethylene diamine (TPEN) or supplied with zinc chloride, thiols (N-acetyl-cysteine; N-acetyl-homocysteine-thiolactone, L2oxothiozolidine-4 carboxylate) selenium as sodium selenite. The cell viability was measured using the adhesion-proliferation method or a tetrazolium colorimetric assay. The damages induced to cellular membrane were appreciated by determination of thiobarbituric reactants (Tbars) by a fluorometric micromethod. Cellular DNA damage was examined by strand break determination carried out using the method described by Birnboim and Jevcak and by the Comet assay. Our results show that: UVA1 have a main part in cytotoxic effect of UVA and this effect is linked to ROS; thiols and selenium protect cells against UVA radiation with a synergic interaction and this protection acts though an increase in glutathion peroxidase activity; zinc protects against cytotoxicity of UVA and UVB and against UVB induced DNA damages; above all, DNA damages induced by UVA or UVB are significantly prevented by thiol molecules, selenium and zinc. As DNA damages have a main place in photocarcinogenesis, our results point out the potential interest of a photoprotection based on the support of endogenous antioxidant system. The research of new ways for photoprotection is indeed a necessity because sunscreens did not give convincing evidences of efficacy in preventing skin cancers.

Zinc protects against ultraviolet A1-induced DNA damage and apoptosis in cultured human fibroblasts.

Ultraviolet A1 (UVA1) radiation generates reactive oxygen species and the oxidative stress is known as a mediator of DNA damage and of apoptosis. We exposed cultured human cutaneous fibroblasts to UVA1 radiation (wavelengths in the 340-450-nm range with emission peak at 365 nm) and, using the alkaline unwinding method, we showed an immediate significant increase of DNA strand breaks in exposed cells. Apoptosis was determined by detecting cytoplasmic nucleosomes (enzyme-linked immunosorbent assay method) at different time points in fibroblasts exposed to different irradiation doses. In our conditions, UVA1 radiation induced an early (8 h) and a delayed (18 h) apoptosis. Delayed apoptosis increased in a UVA dose-dependent manner. Zinc is an important metal for DNA protection and has been shown to have inhibitory effects on apoptosis. The addition of zinc (6.5 mg/L) as zinc chloride to the culture medium significantly decreased immediate DNA strand breaks in human skin fibroblasts. Moreover, zinc chloride significantly decreased UVA1-induced early and delayed apoptosis. Thus, these data show for the first time in normal cutaneous cultured cells that UVA1 radiation induces apoptosis. This apoptosis is biphasic and appears higher 18 h after the stress. Zinc supplementation can prevent both immediate DNA strand breakage and early and delayed apoptosis, suggesting that this metal could be of interest for skin cell protection against UVA1 irradiation.

Impairment of cultured cell proliferation and metallothionein expression by metal chelator NNN'N'-tetrakis-(2-pyridylmethyl)ethylene diamine.

Metallothioneins (MT) are a family of intracellular, cysteine-rich, zinc-binding proteins. Their expression is constitutive but can also be induced at the transcriptional level by various stimuli. In this study, we exposed HaCaT human keratinocytes to excess zinc (ZnCl2) or to zinc deprivation by the diffusible chelator NNN'N'-tetrakis(2-pyridylmethyl)ethylene diamine (TPEN), and to ultraviolet B (UVB) irradiation. We examined both cell proliferation and MT expression. Cell proliferation was maximally stimulated by 100 microM Zn2+ supply and was markedly inhibited by zinc deprivation or UVB irradiation. Zinc and UVB irradiation both increased MTI and/or MTII as detected by immunocytochemistry and enhanced the baseline level of MT-IIA mRNA, whereas TPEN treatment inhibited MT basal expression. Zinc partially prevented the concentration-dependent, UVB-induced decrease in cell proliferation. On the other hand, TPEN partially prevented the UVB-induced increase in MTIIA mRNA. These results suggest that zinc is involved in defense mechanisms of skin keratinocytes and in their stress-induced response.

Effects of fish oil fatty acids on plasma lipids and lipoproteins and oxidant-antioxidant imbalance in healthy subjects.

The purpose of this study was to investigate the effect of eicosapentaenoic and docosahexaenoic acids on plasma lipids and lipoproteins, lipid peroxidation and antioxidant status in healthy humans. A total of 19 healthy volunteers consumed 6 g/day Maxepa fish oil for 3 weeks (1.8 g n-3 fatty acids/day). At baseline and at day 21, we evaluated plasma lipoproteins, plasma and low-density lipoprotein fatty acids, lipid peroxidation markers (malondialdehyde concentration, low-density lipoprotein peroxidation in vitro), and the content of a number of antioxidants (reduced and oxidized glutathione in whole blood, plasma and erythrocyte glutathione peroxidases, plasma vitamin E and beta carotene). Plasma concentrations of total cholesterol, triglycerides, phospholipids, low-density lipoprotein cholesterol and low-density lipoprotein size did not differ significantly after 3 weeks of supplementation. Adding the fish oil to the diet increased the concentration of n-3 very-long-chain polyunsaturated fatty acids and decreased the concentration of n-6 fatty acid and oleic acid in plasma and low-density lipoprotein. Eicosapentaenoic and docosahexaenoic acid supplementation caused elevated values of the high-density lipoprotein cholesterol due to an increment of the high-density lipoprotein 2 fraction and reduced low-density lipoprotein peroxidation rate in vitro. However, we observed an imbalance between oxidizable substrates and antioxidants with an increased lipid peroxidation, whereas the content of reduced glutathione and beta carotene decreased without any variation in vitamin E. Association of antioxidants with n-3 PUFA could prevent lipid peroxidation and enhance the antiatherogenic effects of n-3 polyunsaturated fatty acids.

Protective effects of antioxidants against UVA-induced DNA damage in human skin fibroblasts in culture.

Ultraviolet A radiation (UVA, 320-400 nm) is mutagenic and induces genomic damage to skin cells. N-acetyl-cysteine (NAC), selenium and zinc have been shown to have antioxidant properties and to exhibit protective effects against UVA cytotoxicity. The present work attempts to delineate the effect of these compounds on genomic integrity of human skin fibroblasts exposed to UVA radiation using the single cell gel electrophoresis (SCGE) or Comet assay. The cells were incubated with NAC (5 mM), sodium selenite (0.6 microM) or zinc chloride (100 microM). Then cells were embedded in low melting point agarose, and immediately submitted to UVA fluences ranging from 1 to 6J/cm2. In the Comet assay, the tail moment increased by 45% (1 J/cm2) to 89% (6J/cm2) in non-supplemented cells (p)<0.01). DNA damage was significantly prevented by NAC, Se and Zn, with a similar efficiency from 1 to 4J/cm2 (p < 0.05). For the highest UVA dose (6J/cm2), Se and Zn were more effective than NAC (p < 0.01).