Enhancement of detoxification of xenobiotic aromatic amine dyes by N-acetyltransferase 1 (NAT1) enzyme on human keratinocytes cells through structural modification.

The metabolic conversion of aromatic amines to N-acetylated forms in skin and keratinocytes depends on N-acetyltransferase-1 (NAT1). Common hair color ingredient such as para-phenylenediamine (PPD) causes allergic contact dermatitis. We explored how different electronic substituents on PPD aided NAT1 enzyme biotransform oxidative arylamine (AA) compounds G1-G13 by N-acetylation, NAT-1 activity assays, metabolism, and in vitro clearance investigations in human keratinocytes, while identifying NAT-1 protein levels by Western blot and qRT-PCR.

Contact allergic dermatitis to skin adhesive after CIED upgrade procedure.

Introduction: The utilization of skin adhesives for closure is typically secondary to its noninvasive application and aesthetic benefits. Allergic reactions to Dermabond™ can occur, though there are no reported cases in pediatric patients following cardiac implantable electronic device (CIED) implantation. The allergic reaction to skin glues is typically to cyanoacrylates, the primary component of Dermabond™.

Delta opioid receptor expression correlates to skin ageing and melanin expression in Asian women.

While the evidence for the implication of opioid receptors (OPr) in ageing is growing, there is, to our knowledge, no study focusing directly on changes in vivo cutaneous OPr expression with increasing age. We thus investigated OPr expression in 30 healthy female Asian volunteers in Southern China whose ages range from the early 20s to the early 60s. Excisional biopsies were taken from the sun-exposed extensor area of the lower arm and the photo-protected area of the upper inner arm.

The Opioid Receptor Influences Circadian Rhythms in Human Keratinocytes through the β-Arrestin Pathway.

The recent emphasis on circadian rhythmicity in critical skin cell functions related to homeostasis, regeneration and aging has shed light on the importance of the circadian clock gene as a vital antitumor gene. Furthermore, delta-opioid receptors (DOPrs) have been identified as playing a crucial role in skin differentiation, proliferation and migration, which are not only essential for wound healing but also contribute to cancer development. In this study, we propose a significant association between cutaneous opioid receptor (OPr) activity and circadian rhythmicity.

Demonstration of Convolutional Neural Networks to Determine Patch Test Reactivity.

Convolutional neural networks (CNNs) have the potential to assist allergists and dermatologists in the analysis of patch tests. Such models can help reduce interprovider variability and improve consistency of patch test interpretations. Our aim is to evaluate the performance of a CNN model as a proof of concept in discriminating between patch tests with reactions and patch tests without reactions.

Honey flower dermatitis: Contact allergy to ellagic acid in Melianthuscomosus.

A case study is reported whereby a patient with no prior allergies developed a strong and spreading delayed-type hypersensitivity reaction to Melianthus plants, nectar and synthetic pigment derived from it after frequent handling of these substances. The lesions improved after treatment with topical steroids and allergen avoidance within 1-2 weeks. Subsequent patch testing with the plants, nectar and synthetic ingredients identified ellagic acid (EA) as the sensitizing agent.

The Diagnostic Value of Delayed-Type Reactions to Perennial Aeroallergens for Atopic Disease.

Delayed-type reactions to aeroallergens have been observed, however, their clinical significance continues to be debated. We assessed the prevalence and significance of delayed-type reactions to aeroallergens in atopic patients. Retrospective study including 266 patients with history or evidence of atopic disease (atopic dermatitis [AD], allergic rhinitis, and/or allergic asthma) and tested via either the intradermal skin test (IDT) or atopy patch test for common aeroallergens, specifically house dust mites (, ) and perennial molds (, ).

Distinct transcriptomic and metabolomic profiles characterize NSAID-induced urticaria/angioedema patients undergoing aspirin desensitization.

Background: There is limited data on the mechanisms of aspirin desensitization in patients with nonsteroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema (NIUA).

Objectives: We sought to characterize the transcriptomic and metabolomic profiles of patients with NIUA undergoing aspirin desensitization.

Methods: PBMCs and plasma were separated from the blood of patients with NIUA undergoing aspirin desensitization for coronary artery disease and NSAID-tolerant controls.

Investigations on detoxification mechanisms of novel para-phenylenediamine analogues through N-acetyltransferase 1 (NAT-1).

Para-phenylenediamine (PPD) is one of the most used chemicals in oxidative hair dyes. However, its use has been associated with adverse effects on health, including contact dermatitis and other systemic toxicities. Novel PPD derivatives have been proposed as a safer replacement for PPD.

What You Need to Know About Hand Hygiene and Dermatitis During the Coronavirus Pandemic.

Increased attention towards infection control measures during the COVID-19 pandemic have brought to light the dermatological consequences of intensified hand hygiene measures. Healthcare workers are inherently at an increased risk of developing both allergic and irritant contact dermatitis. Individuals with a history of atopy are especially vulnerable given their impaired native skin barriers and increased sensitivities at baseline.

Development of novel alternative hair dyes to hazardous para-phenylenediamine.

Most of the permanent hair dye products contain p-phenylenediamine (PPD), a well-known skin sensitizer. PPD may cause cutaneous reactions and leads to allergic contact dermatitis (ACD), a condition with major medical and financial repercussions. Hair dye-induced ACD represents a growing concern both for consumers and the cosmetics industry.

Functionally expressed bitter taste receptor TAS2R14 in human epidermal keratinocytes serves as a chemosensory receptor.

Traditionally, it is theorized that skin sensation is initiated when cutaneous sensory afferents and Merkel cells receive sensory stimuli, while epidermal keratinocytes were deemed to have no role. However, mounting evidence has shown that keratinocytes can initiate skin sensation by receiving sensory stimuli and transmitting sensory information to sensory afferents. Knowledge regarding the mechanisms by which keratinocytes receive exogenous stimuli is limited, with TRP channels and olfactory receptors having been proposed to serve as receptors for exogenous stimuli in keratinocytes.

Atopic Patients Who Fulfilled Rome III Criteria for Irritable Bowel Syndrome Had Higher Animal Danders Sensitization.

Background/aims: The relationship between animal exposure and irritable bowel syndrome (IBS) is debated. Epidemiological studies have shown that atopy is more prevalent in IBS patients and vice versa. We set out to examine the association between animal danders sensitization and IBS-like symptoms in atopic patients.

Progressive expression of PPARGC1α is associated with hair miniaturization in androgenetic alopecia.

Current opinion views androgens as the pathogenic driver in the miniaturization of hair follicles of androgenetic alopecia by interfering with the dermal papilla. This cannot be the sole cause and therefore it is important for therapeutic and diagnostic purposes to identify additional pathways. Comparative full transcriptome profile analysis of the hair bulb region of normal and miniaturized hair follicles from vertex and occipital region in males with and without androgenetic alopecia revealed that next to the androgen receptor as well the retinoid receptor and particularly the PPAR pathway is involved in progressive hair miniaturization.

Microbiome in the hair follicle of androgenetic alopecia patients.

Androgenetic alopecia is the most common form of hair loss in males. It is a multifactorial condition involving genetic predisposition and hormonal changes. The role of microflora during hair loss remains to be understood.

Controversies in drug allergy: Testing for delayed reactions.

Controversies exist with regard to in vivo approaches to delayed immunologically mediated adverse drug reactions, such as exanthem (maculopapular eruption), drug reaction with eosinophilia and systemic symptoms, acute generalized exanthematous pustulosis, Stevens-Johnson syndrome/toxic epidermal necrolysis, and fixed drug eruptions. In particular, widespread differences exist between regions and practice on the availability and use of intradermal and patch testing, the standard drug concentrations used, the use of additional drugs in intradermal and patch testing to help determine cross-reactivity, the timing of testing in relation to the occurrence of the adverse drug reaction, the use of testing in specific phenotypes, and the use of oral challenge in conjunction with delayed intradermal and patch testing to ascertain drug tolerance. It was noted that there have been advances in the science of delayed T cell-mediated reactions that have shed light on immunopathogenesis and provided a mechanism of preprescription screening in the case of HLA-B*57:01 and abacavir hypersensitivity and HLA-B*15:02 and carbamazepine Stevens-Johnson syndrome/toxic epidermal necrolysis in Southeast Asian subjects.

Role of Skin pH in Psoriasis.

Not much is known about the role of skin pH in skin pathophysiology, in particular in psoriasis. However, there is compelling evidence that the epidermal pH can influence the skin homeostasis and affect the skin barrier by changing the activity of cutaneous enzymes and through the modulation of skin inflammation and microbial colonization. This includes the activation of secretory phospholipase A and interaction with the peroxisome proliferators-activated receptor and retinoid pathways.

Full-Thickness Human Skin Equivalent Models of Atopic Dermatitis.

Atopic dermatitis is a chronic inflammatory skin disease caused by complex multifactorial etiology. In the recent years, there have been significant advances in tissue engineering and the generation of in vitro skin models representative of healthy and diseased states. This chapter describes the methodology for the fabrication of in vitro human skin equivalent (HSE) from human keratinocytes and fibroblasts using a fibrin-based dermal matrix and serum-free culture conditions.

Correction: Physical and compositional analysis of differently cultured 3D human skin equivalents by confocal Raman spectroscopy.

Correction for 'Physical and compositional analysis of differently cultured 3D human skin equivalents by confocal Raman spectroscopy' by Y. Dancik, et al., Analyst, 2018, DOI: .

Physical and compositional analysis of differently cultured 3D human skin equivalents by confocal Raman spectroscopy.

Three-dimensional skin equivalents are increasingly gaining acceptance as non-animal based experimental models of human skin. They are particularly suited to studying differences in physical and compositional properties of normal and diseased skin and their impact on the skin's barrier function. Typically, a culture protocol yielding a model of normal skin is modified to create a model simulating a pathology.

Investigating endogenous µ-opioid receptors in human keratinocytes as pharmacological targets using novel fluorescent ligand.

Opioids in skin function during stress response, regeneration, ageing and, particularly in regulating sensation. In chronic pruritus, topical treatment with Naltrexone changes μ-opioid receptor (μ-OR) localization to relieve itch. The molecular mechanisms behind the effects of Naltrexone on μ-OR function in reduction of itching behavior has not been studied.