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The Australasian Journal of Dermatology Aug 2020Chlorpromazine is known to produce both systemic phototoxic and photoallergic reactions. However, it may also cause photoallergic contact dermatitis and, albeit...
Chlorpromazine is known to produce both systemic phototoxic and photoallergic reactions. However, it may also cause photoallergic contact dermatitis and, albeit exceptionally, allergic contact dermatitis (ACD). We present a series of photoallergic contact dermatitis and ACD to chlorpromazine diagnosed at a tertiary centre cutaneous allergy unit between 1980 and 2019.
Topics: Adult; Antipsychotic Agents; Cheilitis; Chlorpromazine; Dermatitis, Photoallergic; Eyelids; Facial Dermatoses; Female; Fingers; Hand Dermatoses; Humans; Middle Aged; Patch Tests; Retrospective Studies
PubMed: 32141075
DOI: 10.1111/ajd.13254 -
Journal of Physics D: Applied Physics Apr 2020Super-resolution microscopy (SRM) enables non-invasive, molecule-specific imaging of the internal structure and dynamics of cells with sub-diffraction limit spatial... (Review)
Review
Super-resolution microscopy (SRM) enables non-invasive, molecule-specific imaging of the internal structure and dynamics of cells with sub-diffraction limit spatial resolution. One of its major limitations is the requirement for high-intensity illumination, generating considerable cellular phototoxicity. This factor considerably limits the capacity for live-cell observations, particularly for extended periods of time. Here, we give an overview of new developments in hardware, software and probe chemistry aiming to reduce phototoxicity. Additionally, we discuss how the choice of biological model and sample environment impacts the capacity for live-cell observations.
PubMed: 33994582
DOI: 10.1088/1361-6463/ab6b95 -
Food and Chemical Toxicology : An... Jul 2021The existing information supports the use of this material as described in this safety assessment. Ethyl 2-methyl-4-pentenoate was evaluated for genotoxicity, repeated... (Review)
Review
The existing information supports the use of this material as described in this safety assessment. Ethyl 2-methyl-4-pentenoate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog methyl undec-10-enoate (CAS # 111-81-9) show that ethyl 2-methyl-4-pentenoate is not expected to be genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the threshold of toxicological concern (TTC) for a Cramer Class I material, and the exposure to ethyl 2-methyl-4-pentenoate is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). The skin sensitization endpoint was completed using the Dermal Sensitization Threshold (DST) for non-reactive materials (900 μg/cm); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; ethyl 2-methyl-4-pentenoate is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; ethyl 2-methyl-4-pentenoate was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.
Topics: Animals; Bacteria; Consumer Product Safety; Endpoint Determination; Fatty Acids, Monounsaturated; Humans; Odorants; Perfume; Risk Assessment; Valerates
PubMed: 33838174
DOI: 10.1016/j.fct.2021.112170 -
Journal of Drugs in Dermatology : JDD Oct 2022Tapinarof (VTAMA®; Dermavant Sciences, Inc.) is a novel, non-steroidal, topical, aryl hydrocarbon receptor agonist, FDA approved for psoriasis treatment and under... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Tapinarof (VTAMA®; Dermavant Sciences, Inc.) is a novel, non-steroidal, topical, aryl hydrocarbon receptor agonist, FDA approved for psoriasis treatment and under investigation for atopic dermatitis treatment as a 1% cream formulation for once-daily (QD) application.
OBJECTIVE
Evaluate cumulative skin irritation, sensitization, and photoallergic and phototoxic potential of tapinarof cream 1% across a range of dosing frequencies and conditions.
METHODS
We conducted 4 randomized, controlled, phase 1 trials of topical tapinarof cream 1% vs vehicle or other appropriate controls in healthy adults. Cumulative skin irritation was assessed following QD application for 21 days under fully occlusive patch conditions. Contact sensitization, photoallergenicity, and phototoxicity were assessed under semi-occlusive patch conditions. The contact sensitization and photoallergenicity trials used an induction phase of repeated applications followed by a 2-week rest period and a 1-time challenge, with rechallenge if responses indicated sensitization/photosensitization; the phototoxicity trial comprised a single application. Ultraviolet A and B irradiation was used to assess photoallergenicity/toxicity.
RESULTS
376 participants were randomized across the 4 trials. In the cumulative irritation trial, tapinarof cream 1% QD was classified as having a slight potential for very mild cumulative irritation under the exaggerated test conditions of repeated dosing for 21 days. There was no evidence of sensitization, photosensitization, or phototoxicity. Tapinarof was well tolerated and there was a low discontinuation rate across all trials.
CONCLUSIONS
Tapinarof cream 1% was well tolerated, non-sensitizing, non-phototoxic, and non-photoallergic, with no evidence of clinically meaningful cumulative skin irritation in 4 dermal safety trials in healthy adults.
TRIAL REGISTRATION
IND 104601 J Drugs Dermatol. 2022;21(10):1084-1090. doi:10.36849/JDD.6627R1.
Topics: Adult; Dermatitis, Photoallergic; Dermatitis, Phototoxic; Humans; Receptors, Aryl Hydrocarbon; Resorcinols; Skin Cream
PubMed: 36219046
DOI: 10.36849/JDD.6627 -
Food and Chemical Toxicology : An... Jul 2020The existing information supports the use of this material as described in this safety assessment. 4-(2-Butenylidene)-3,5,5-trimethylcyclohex-2-en-1-one was evaluated... (Review)
Review
The existing information supports the use of this material as described in this safety assessment. 4-(2-Butenylidene)-3,5,5-trimethylcyclohex-2-en-1-one was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 4-(2-butenylidene)-3,5,5-trimethylcyclohex-2-en-1-one is not genotoxic. Data on 4-(2-butenylidene)-3,5,5-trimethylcyclohex-2-en-1-one provide a calculated margin of exposure (MOE) > 100 for the repeated dose toxicity endpoint. The reproductive and local respiratory toxicity endpoints were evaluated using the threshold of toxicological concern (TTC) for a Cramer Class I material, and the exposure to 4-(2-butenylidene)-3,5,5-trimethylcyclohex-2-en-1-one is below the TTC (0.03 mg/kg/day and 1.4 mg/day, respectively). The skin sensitization endpoint was completed using the dermal sensitization threshold (DST) for reactive materials (64 μg/cm); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on data; 4-(2-butenylidene)-3,5,5-trimethylcyclohex-2-en-1-one is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 4-(2-butenylidene)-3,5,5-trimethylcyclohex-2-en-1-one was found not to be persistent, bioaccumulative, and toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.
Topics: Animals; Cyclohexanones; Humans; Mutagenicity Tests; Odorants; Perfume; Toxicity Tests
PubMed: 32360215
DOI: 10.1016/j.fct.2020.111377 -
Food and Chemical Toxicology : An... Oct 2020Furfuryl thioacetate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin... (Review)
Review
Furfuryl thioacetate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that furfuryl thioacetate is not genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the threshold of toxicological concern (TTC) for a Cramer Class III material, and the exposure to furfuryl thioacetate is below the TTC (0.0015 mg/kg/day, 0.0015 mg/kg/day, and 0.47 mg/day, respectively). The skin sensitization endpoint was completed using the dermal sensitization threshold (DST) for reactive materials (64 μg/cm); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; furfuryl thioacetate is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; furfuryl thioacetate was found not to be persistent, bioaccumulative, and toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.
Topics: Animals; Dermatitis, Phototoxic; Humans; Mutagenicity Tests; Perfume; Registries; Risk Assessment
PubMed: 32781229
DOI: 10.1016/j.fct.2020.111615 -
Anais Brasileiros de Dermatologia 2022The therapeutic approach to metastatic melanoma has revolutionized the clinical course of this disease. Since 2011, different immunotherapeutic drugs have been approved....
The therapeutic approach to metastatic melanoma has revolutionized the clinical course of this disease. Since 2011, different immunotherapeutic drugs have been approved. Nivolumab is a humanized immunoglobulin IgG4 monoclonal antibody that binds to the PD-1 receptor, blocking its interaction with his ligand PD-L1. The authors present a new case of photosensitivity induced by nivolumab. The photo exposed distribution of the eruption, the sun exposure prior to the beginning of the eruption, and the chronological relationship with the beginning of the treatment are data that have allowed us to confirm the suspected clinical diagnosis.
Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Dermatitis, Phototoxic; Exanthema; Humans; Melanoma; Nivolumab; Programmed Cell Death 1 Receptor
PubMed: 35811193
DOI: 10.1016/j.abd.2021.07.007 -
Food and Chemical Toxicology : An... Mar 2021The existing information supports the use of this material as described in this safety assessment. 2-Mercaptopropionic acid was evaluated for genotoxicity, repeated dose... (Review)
Review
The existing information supports the use of this material as described in this safety assessment. 2-Mercaptopropionic acid was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 2-mercaptopropionic acid is not genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material, and the exposure to 2-mercaptopropionic acid is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). The skin sensitization endpoint was completed using the Dermal Sensitization Threshold (DST) for reactive materials (64 μg/cm); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; 2-mercaptopropionic acid is not expected to be phototoxic/photoallergenic. For the hazard assessment based on the screening data, 2-mercaptopropionic acid is not persistent, bioaccumulative, and toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards. For the risk assessment, 2-mercaptopropionic acid was not able to be risk screened as there were no reported volumes of use for either North America or Europe in the 2015 IFRA Survey.
Topics: Animals; Dose-Response Relationship, Drug; Humans; Odorants; Quantitative Structure-Activity Relationship; Reproduction; Risk Assessment; Sulfhydryl Compounds; Toxicity Tests
PubMed: 33460696
DOI: 10.1016/j.fct.2021.111987 -
Photochemistry and Photobiology Mar 2023Photodynamic therapy can be useful for the eradication of malignant cells at sites that are accessible to light delivery. There are few adverse effects, with many...
Photodynamic therapy can be useful for the eradication of malignant cells at sites that are accessible to light delivery. There are few adverse effects, with many clinical reports indicating that PDT has curative potential. Patients with minimal disease, where success is more likely, are also sought by those promoting other protocols. New photosensitizing agents that initiate light-catalyzed reactions continue to be discovered. Reports describing advances in understanding fundamental aspects of photobiology are always of interest. But, implications for treatment of neoplasia and other diseases are not always justified, especially when poorly penetrating wavelengths of light are employed, often at very high light doses. Efficacy is sometimes estimated by protocols that may not accurately measure photokilling. Many reports claiming potential clinical relevance for in vitro observations are based on a limited understanding of the determinants of clinical efficacy. The future of photodynamic therapy depends on an appreciation of what can be accomplished, especially when used with other modalities, but will also depend on the goals and interests of granting agencies, pharmaceutical groups, and clinical personnel. This commentary is intended to provide some thoughts on current research efforts, especially where clinical implications are suggested, hinted at or otherwise implied.
Topics: Humans; Photochemotherapy; Photosensitizing Agents; Dermatitis, Phototoxic; Neoplasms; Treatment Outcome
PubMed: 35290667
DOI: 10.1111/php.13616 -
BioEssays : News and Reviews in... May 2024Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to... (Review)
Review
Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to erroneous or inconclusive results. Recently, several reports have addressed this issue, but it is still underestimated by many researchers, even though it can lead to cell death. Phototoxicity can be reduced by appropriate microscopic techniques and carefully designed experiments. This review focuses on recent strategies to reduce phototoxicity in microscopic imaging of living cells and tissues. We describe digital image processing and new hardware solutions. We point out new modifications of microscopy methods and hope that this review will interest microscopy hardware engineers. Our aim is to underscore the challenges and potential solutions integral to the design of microscopy systems. Simultaneously, we intend to engage biologists, offering insight into the latest technological advancements in imaging that can enhance their understanding and practice.
Topics: Humans; Microscopy, Fluorescence; Animals; Image Processing, Computer-Assisted
PubMed: 38514402
DOI: 10.1002/bies.202300122