Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0920652 (skin irritant)
188 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study investigates the extent to which sunscreens protect humans from ultraviolet (UV)-radiation-induced immunosuppression. In the presence of solar-simulated UV, three sunscreens with differing UVA transmission were assessed for their ability to protect the contact hypersensitivity (CHS) response to nickel of 16 nickel-allergic subjects. The sunscreens contained 2-ethylhexyl para-methoxycinnamate (cinnamate), cinnamate with oxybenzone, or cinnamate with zinc oxide, respectively. All had sun protection factors of 10 and hence inhibited UV erythema to similar extents. Volunteers were irradiated on their backs with suberythemal UV daily for 5 d after application of the sunscreens and their base lotion to different sites. Nickel-containing patches were then applied to both UV-treated sites and adjacent, unirradiated control sites. Erythema caused by nickel CHS at each site was quantitated 72 h later with a reflectance erythema meter. In comparison of the nickel reactions of irradiated and unirradiated skin, there was 35% mean immunosuppression in unprotected UV-treated skin. Significant immunosuppression also occurred at sites irradiated through the narrow-spectrum cinnamate-only sunscreen but was prevented by the two broad-spectrum sunscreens. To determine whether UV-induced suppression of the nickel response is specific for cell-mediated immunity or reflects suppression of nonspecific inflammation, a further 16 subjects were patch-tested with a skin irritant, sodium lauryl sulfate (SLS), following a sunscreen and irradiation protocol identical to that of the nickel volunteers. UV had no significant effect on SLS responses. We conclude that nickel patch testing is a valid means of assessing UV-induced immunosuppression in humans and that even with suberythemal UV, immune protection was provided only by sunscreens filtering both UVA and UVB.
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PMID:Broad-spectrum sunscreens provide greater protection against ultraviolet-radiation-induced suppression of contact hypersensitivity to a recall antigen in humans. 924 99

The murine local lymph node assay (LLNA) is a method for the predictive identification of chemicals that have a potential to cause skin sensitization. Activity is measured as a function of lymph node cell (LNC) proliferative responses stimulated by topical application of test chemicals. Those chemicals that induce a threefold or greater increase in LNC proliferation compared with concurrent vehicle controls are classified as skin sensitizers. In the present investigations we have evaluated further the reliability and accuracy of the LLNA. In the context of an international interlaboratory trial the sensitization potentials of six materials with a history of use in topical medicaments have been evaluated: benzoyl peroxide, hydroquinone, penicillin G, streptomycin sulfate, ethylenediamine dihydrochloride, and methyl salicylate. Each chemical was analyzed in the LLNA by all five laboratories. Either the standard LLNA protocol or minor modifications of it were used. Benzoyl peroxide and hydroquinone, both human contact allergens, elicited strong LLNA responses in each laboratory. Penicillin G, another material shown previously to cause allergic contact dermatitis in humans, was also positive in all laboratories. Streptomycin sulfate induced equivocal responses, in that this material provoked a positive LLNA response in only one of the five laboratories, and then only at the highest concentration tested. Ethylenediamine dihydrochloride dissolved in a 3:1 mixture of acetone with water, or in 4:1 acetone:olive oil (one laboratory), was uniformly negative. However, limited further testing with the free base of ethylene diamine yielded a positive LLNA response when applied in acetone:olive oil (AOO). Finally, methyl salicylate, a nonsensitizing skin irritant, was negative at all test concentrations in each laboratory. Collectively these data serve to confirm that the local lymph node assay is sufficiently robust to yield equivalent results when performed independently in separate laboratories and indicate also that the LLNA is of value in assessing the skin sensitization potential of topical medicaments.
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PMID:Assessment of the skin sensitization potential of topical medicaments using the local lymph node assay: an interlaboratory evaluation. 956 69

Literature from the first half of this century report concern for toxicity from topical use of boric acid, but assessment of percutaneous absorption has been impaired by lack of analytical sensitivity. Analytical methods in this study included inductively coupled plasma-mass spectrometry which now allows quantitation of percutaneous absorption of 10B in 10B-enriched boric acid, borax, and disodium octaborate tetrahydrate (DOT) in biological matrices. This made it possible, in the presence of comparatively large natural dietary boron intakes for the in vivo segment of this study, to quantify the boron passing through skin. Human volunteers were dosed with 10B-enriched boric acid, 5.0%, borax, 5.0%, or disodium octaborate tetrahydrate, 10%, in aqueous solutions. Urinalysis, for boron and changes in boron isotope ratios, was used to measure absorption. Boric acid in vivo percutaneous absorption was 0.226 (SD = 0.125) mean percentage dose, with flux and permeability constant (Kp) calculated at 0.009 microgram/cm2/h and 1.9 x 10(-7) cm/h, respectively. Borax absorption was 0.210 (SD = 0.194) mean percentage of dose, with flux and Kp calculated at 0.009 microgram/cm2/h and 1.8 x 10(-7) cm/h, respectively. DOT absorption was 0.122 (SD = 0.108) mean percentage, with flux and Kp calculated at 0.01 microgram/cm2/h and 1.0 x 10(-7) cm/h, respectively. Pretreatment with the potential skin irritant 2% sodium lauryl sulfate had no effect on boron skin absorption. In vitro human skin percentage of doses of boric acid absorbed were 1.2 for a 0.05% solution, 0.28 for a 0.5% solution, and 0.70 for a 5.0% solution. These absorption amounts translated into flux values of, respectively, 0.25, 0.58, and 14.58 micrograms/cm2/h and permeability constants (Kp) of 5.0 x 10(-4), 1.2 x 10(-4), and 2.9 x 10(-4) cm/h for the 0.05, 0.5, and 5.0% solutions. The above in vitro doses were at infinite, 1000 microliters/cm2 volume. At 2 microliters/cm2 (the in vivo dosing volume), flux decreased some 200-fold to 0.07 microgram/cm2/h and Kp of 1.4 x 10(-6) cm/h, while percentage of dose absorbed was 1.75%. Borax dosed at 5.0%/1000 microliters/cm2 had 0.41% dose absorbed, flux at 8.5 micrograms/cm2/h, and Kp was 1.7 x 10(-4) cm/h. Disodium octaborate tetrahydrate (DOT) dosed at 10%/1000 microliters/cm2 was 0.19% dose absorbed, flux at 7.9 micrograms/cm2/h, and Kp was 0.8 x 10(-4) cm/h. These in vitro results from infinite doses (1000 microliters/cm2) were 1000-fold greater than those obtained in the companion in vivo study. The results from the finite (2 microliters/cm2) dosing were closer (10-fold difference) to the in vivo results. General application of infinite dose percutaneous absorption values for risk assessment is questioned by these results. These in vivo results show that percutaneous absorption of boron, as boric acid, borax, and disodium octaborate tetrahydrate, through intact human skin, is low and is significantly less than the average daily dietary intake. This very low boron skin absorption makes it apparent that, for the borates tested, the use of gloves to prevent systemic uptake is unnecessary. These findings do not apply to abraded or otherwise damaged skin.
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PMID:In vivo percutaneous absorption of boric acid, borax, and disodium octaborate tetrahydrate in humans compared to in vitro absorption in human skin from infinite and finite doses. 984 9

Literature from the first half of this century reports concern for toxicity from topical use of boric acid, but assessment of percutaneous absorption has been impaired by lack of analytical sensitivity. Analytical methods in this study included inductively coupled plasma-mass spectrometry, which now allows quantitation of percutaneous absorption of 10B in 10B-enriched boric acid, borax, and disodium octaborate tetrahydrate (DOT) in biological matrices. This made it possible, in the presence of comparatively large natural dietary boron intakes for the in vivo segment of this study, to quantify the boron passing through skin. Human volunteers were dosed with 10B-enriched boric acid, 5.0%, borax, 5.0%, or disodium octaborate tetrahydrate, 10% in aqueous solutions. Urinalysis, for boron and changes in boron isotope ratios, was used to measure absorption. Boric acid in vivo percutaneous absorption was 0.226 (SD = 0.125) mean percent dose, with flux and permeability constant (Kp) calculated at 0.009 microg/cm2/h and 1.9 x 10(-7) cm/h, respectively. Borax absorption was 0.210 (SD = 0.194) mean percent dose, with flux and Kp calculated at 0.009 microg/cm2/h and 1.8 x 10(-7) cm/h, respectively. DOT absorption was 0.122 (SD = 0.108) mean percent, with flux and Kp calculated at 0.01 microg/cm2/h and 1.0 x 10(-7) cm/h, respectively. Pretreatment with the potential skin irritant 2% sodium lauryl sulfate had no effect on boron skin absorption. These in vivo results show that percutaneous absorption of boron, as boric acid, borax, and disodium octaborate tetrahydrate, through intact human skin is low and is significantly less than the average daily dietary intake. This very low boron skin absorption makes it apparent that, for the borates tested, the use of gloves to prevent systemic uptake is unnecessary. These findings do not apply to abraded or otherwise damaged skin.
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PMID:In vivo percutaneous absorption of boron as boric acid, borax, and disodium octaborate tetrahydrate in humans: a summary. 1005 Sep 12

The main goal of the present study was to investigate the response of the human skin equivalent Apligraf in vitro to the application of irritant substances and its predictivity as a screening tool for cumulative skin irritant potential in humans. Vaseline, calcipotriol, trans-retinoic acid, and sodium lauryl sulfate were applied to Apligraf in vitro for 24 h. Cell viability (lactate dehydrogenase leakage), release and mRNA expression of the proinflammatory cytokines IL-1alpha and IL-8, and morphological changes were assessed. The same products were applied to 30 healthy volunteers in a double-blind, randomized, vehicle-controlled within-subject study. The skin reactions after repeated 24-h applications over 3 weeks under Finn chamber patches were monitored by visual scoring and biophysical methods (trans-epidermal water loss, chromametry, and blood flow). Sodium lauryl sulfate was cytotoxic to Apligraf, and increased the release and expression of cytokines at low (0.2%, 0. 4%), but not at high (0.8%, 1%) concentrations. It induced severe irritancy in vivo. Trans-retinoic acid increased the expression and release of cytokines with no detectable cytotoxicity and showed moderate irritancy in humans. Although calcipotriol did neither affect cell viability nor the production of cytokines, it induced morphological signs of irritation and was mildly irritant for healthy volunteers. Vaseline was innocuous in vivo and induced no changes in Apligraf. In conclusion, the cumulative skin irritation potential of the tested products could be predicted with Apligraf in a sensitive and specific manner, by monitoring cytotoxicity, proinflammatory cytokines, and morphological changes.
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PMID:Use of human skin equivalent Apligraf for in vitro assessment of cumulative skin irritation potential of topical products. 1073 42

It has been reported previously that in vitro treatment of human blood derived dendritic cells (DC) with contact allergens provokes the elevated expression of mRNA for interleukin (IL) 1beta, under conditions where similar treatment of cells with the non-sensitizing skin irritant sodium lauryl sulfate (SLS) did not alter IL-1beta mRNA levels (Reutter et al., 1997). The purpose of the present investigation was to evaluate further this phenomenon and to explore the potential utility of this approach for the purpose of skin sensitization testing. Human peripheral blood progenitor cells prepared from healthy adult volunteers were cultured in the presence of IL-4 and granulocyte/macrophage colony stimulating factor. After 5 days of culture, the majority of cells had a Langerhans cell-like phenotype, with characteristic dendritic morphology and cell surface expression of CD83, major histocompatibility complex class II and CD1a determinants. These blood-derived DC were cultured in the presence of the contact allergen 2,4-dinitrofluorobenzene (DNFB), SLS or vehicle alone and mRNA expression for IL-1beta, IL-6 and IL-18 was analysed by semiquantitative reverse transcriptase polymerase chain reaction. Constitutive expression of all three cytokines was observed for DC isolated from all donors examined. Exposure to DNFB resulted in upregulation of IL-1beta mRNA (two- to threefold) in cells derived from three out of eight donors whereas IL-6 and IL-18 were largely unaffected by allergen exposure. In contrast, SLS treatment did not induce IL-1beta mRNA expression in any of the donors investigated. Analysis of cytokine mRNA expression using the protocol described by Reutter et al. (1997), did not increase the sensitivity of measurement of induced cytokine expression. Although selected upregulation of IL-1beta by blood derived DC has been confirmed, a wider range of contact allergens and irritants need to be assessed before this approach could be considered for hazard identification.
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PMID:Investigation of induced changes in interleukin 1beta mRNA expression by cultured human dendritic cells as an in vitro approach to skin sensitization testing. 1090 42

Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-18 are all known to contribute to the regulation of epidermal Langerhans cells (LC) migration and the subsequent accumulation of dendritic cells (DC) in draining lymph nodes following skin sensitization. However, the cytokine signals that control these responses following skin irritation have yet to be defined. We demonstrate that IL-1alpha, a cytokine associated with skin injury and inflammation, is able to stimulate the activation and migration from the epidermis of LC and their subsequent accumulation in skin-draining lymph nodes. Stimulation of these responses by IL-1alpha required the local availability of TNF-alpha. Using specific neutralizing antibodies, LC migration induced following skin sensitization with oxazolone (Ox) was found to be dependent upon IL-1beta and independent of a requirement for IL-1alpha. However, the converse was true following stimulation of responses with the nonsensitizing skin irritant sodium lauryl sulfate (SLS). Here, the loss of LC from the epidermis and the accumulation of DC in draining lymph nodes required IL-1alpha and not IL-1beta. Despite utilizing different IL-1 isoforms for LC mobilization, the phenotypic characteristics of DC arriving in draining lymph nodes in response to Ox and SLS were similar with respect to the membrane determinants MHC class II, B7-1, B7-2, and intercellular adhesion molecule-1. These data suggest that contact sensitization and skin irritation employ subtly different cytokine networks in the regulation of LC migration, both involving TNF-alpha but demonstrating differential requirements for IL-1 cytokines. The proposal is that different forms of cutaneous trauma may achieve LC migration through distinct molecular mechanisms.
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PMID:Differential regulation of epidermal langerhans cell migration by interleukins (IL)-1alpha and IL-1beta during irritant- and allergen-induced cutaneous immune responses. 1214 Jan 76

Although skin and respiratory sensitizing properties of platinum compounds have been proved in humans and mice, little is known about signal transduction pathways leading to cytokine production in the induction phase. It is generally assumed that induction of skin sensitization, but not skin irritation, is associated with a rapid increase in the IL-1beta mRNA expression. In this study, IL-1beta expression and a role of mitogen-activated protein kinases (MAPKs) in this process were investigated in murine macrophages J774A.1 exposed to four platinum compounds. Potassium tetrachloroplatinate (K(2)PtCl(4); TCPP), ammonium tetrachloroplatinate ((NH(4))(2)PtCl(4); TCPA), ammonium hexachloroplatinate ((NH(4))(2)PtCl(6); HCPA) showed a very similar range of cytotoxic concentrations (IC(50) values: 238 microM+/-30; 269 microM+/-39 and 245 microM+/-31, respectively) as assessed in the 24-h MTT reduction test. Cytotoxicity of cis-diammineplatinum dichloride (cisplatin) was considerably higher (IC(50) of 23 microM+/-4). While increased expression of IL-1beta mRNA was observed in the macrophages exposed to each test compound, IL-1beta protein production was detected in cell lysates after treatment with TCPP, TCPA and HCPA for 24h (concentration range of 150-350 microM) as well as for 2h (450-650 microM). The treatment with each compound resulted in the phosphorylation of both p38 MAPK and ERK 1/2 (p44/42). Blocking the activation of p38 MAPK as well as ERK 1/2 with specific inhibitors (SB203580 and U0126, respectively) down-regulated the IL-1beta expression. Interestingly, the skin irritant sodium dodecyl sulfate did not trigger phosphorylation of these kinases, nor induced IL-1beta production. These data suggest that p38 MAPK and ERK 1/2 play an important role in induction of IL-1beta expression in J774A.1 macrophages exposed to test platinum compounds.
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PMID:Interleukin-1beta expression in murine J774A.1 macrophages exposed to platinum compounds: the role of p38 and ERK 1/2 mitogen-activated protein kinases. 1708 86

The impact of many human variables on the response to skin irritating substances has been studied to varying degrees, including the impact of age, sex, and atopic status. However, the importance of ethnic origin has been more difficult to investigate, leading to a relative paucity of compelling data, either for or against the existence of differences. A primary reason for this lack is that studies on different ethnic groups often have to be undertaken in different locations thus introducing variables, e.g. time, environmental conditions that confound interpretations. In the present work, an attempt has been made to eliminate all variables except ethnicity by conducting a study on 2 distinct populations (Punjabis and Tamils) at the same location on the same day with a single assessor of the skin reactions, using sodium lauryl sulfate as the skin irritant. The skin reactions were assessed visually, and it was demonstrated that the modality of the reactions in these 2 populations had clear differences, but that the dose-response profiles were very similar. Thus, although the irritant response was expressed differently (e.g. erythema was much less evident in the darker Tamil population), the overall outcome was that the populations reacted in an equivalent manner.
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PMID:The effect of population diversity on skin irritation. 1710 Oct 12

The stratum corneum (SC) serves as the skin barrier between the body and the environment. When the skin is contacted with an aqueous solution of the surfactant sodium dodecyl sulfate (SDS), a well-known model skin irritant, SDS penetrates into the skin and disrupts this barrier. It is well established, both in vitro and in vivo, that the SDS skin penetration is dose-dependent, and that it increases with an increase in the total SDS concentration above the critical micelle concentration (CMC) of SDS. However, when we added the humectant glycerol at a concentration of 10 wt% to the aqueous SDS contacting solution, we observed, through in vitro quantitative skin radioactivity assays using (14)C-radiolabeled SDS, that the dose dependence in SDS skin penetration is almost completely eliminated. To rationalize this important observation, which may also be related to the well-known beneficial effects of glycerol on skin barrier perturbation in vivo, we hypothesize that the addition of 10 wt% glycerol may hinder the ability of the SDS micelles to penetrate into the skin barrier through aqueous pores that exist in the SC. To test this hypothesis, we conducted mannitol skin permeability as well as average skin electrical resistivity measurements in vitro upon exposure of the skin to an aqueous SDS contacting solution and to an aqueous SDS + 10 wt% glycerol contacting solution in the context of a hindered-transport aqueous porous pathway model of the SC. Our in vitro studies demonstrated that the addition of 10 wt% glycerol: (i) reduces the average aqueous pore radius resulting from exposure of the skin to the aqueous SDS contacting solution from 33 +/- 5 Angstrom to 20 +/- 5 Angstrom, such that a SDS micelle of radius 18.5 +/- 1 Angstrom (as determined using dynamic light-scattering measurements) experiences significant steric hindrance and cannot penetrate into the SC, and (ii) reduces the number density of aqueous pores in the SC by more than 50%, thereby further reducing the ability of the SDS micelles to penetrate into the SC and perturb the skin barrier.
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PMID:The role of sodium dodecyl sulfate (SDS) micelles in inducing skin barrier perturbation in the presence of glycerol. 1752 Jan 52


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