Immunohistochemical differentiation of keratins and involucrin between palmar psoriasis, chronic hand eczema and hyperkeratotic hand eczema.

BACKGROUND: Common hyperkeratotic palmar skin lesions include chronic hand eczema (CHE), hyperkeratotic hand eczema (HHE), palmar psoriasis (PP). However, clinically differentiating these disorders is often challenging. OBJECTIVES: To compare the expressions of keratin (K) 5, K9, K14 and involucrin in palmar hyperkeratotic lesions (HHE, CHE and PP). MATERIALS AND METHODS: Immunohistochemical staining was performed on skin biopsy specimens obtained from the palms of patients clinically diagnosed with CHE, HHE and PP (n = 21, 24 and 18, respectively). RESULTS: K5 and K14 expression levels were higher in the spinous and granular layers of PP and HHE compared to CHE. Involucrin was expressed in the basal layer of PP and HHE but not in CHE. K9 expression was decreased in PP and HHE compared to CHE. CONCLUSION: Keratin and involucrin expression in the epidermis are markers of keratinocyte differentiation. Expression levels of keratin and involucrin were similar between the HHE and PP groups, suggesting that HHE shares pathogenesis with PP rather than CHE.

Ultra-High-Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry for Simultaneous Pesticide Analysis and Method Validation in Sweet Pepper.

Pesticides effectively reduce the population of various pests that harm crops and increase productivity, but leave residues that adversely affect health and the environment. Here, a simultaneous multicomponent analysis method based on ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) pretreated by the QuEChERS method was developed to control the maximum residual levels. Among the 140 pesticides with high frequency of detection in agricultural products in Gyeongnam region in Korea for 5 years, 12 pesticides with high detection frequency in sweet pepper were selected. The analytical method is validated, linearities are r2 > 0.999, limit of detection (LOD) ranges from 1.4 to 3.2 µg/kg, and limit of quantification (LOQ) ranges from 4.1 to 9.7 µg/kg, and the recovery rate was 81.7-99.7%. In addition, it was confirmed that a meaningful value of these parameters can be achieved by determining the measurement uncertainty. The results proved that parameters such as recovery rate and relative standard deviation of the analysis method were within international standards. Using the developed method, better and safer sweet peppers will be provided to consumers, and effective pesticide residue management will be possible by expanding to other agricultural products.

Polydeoxyribonucleotide exerts opposing effects on ERK activity in human skin keratinocytes and fibroblasts.

Polydeoxyribonucleotide (PDRN) is a mixture of deoxyribonucleotides. It serves as an anti­inflammatory and tissue­regenerating agent. The mitogen­activated protein kinase pathway modulates cell growth and collagen accumulation. It also regulates inflammation by suppressing the expression of proinflammatory cytokines. In the present study, it was attempted to elucidate the molecular mechanism of PDRN in skin healing by confirming the effects of PDRN treatment on skin keratinocytes and fibroblasts, and by assessing the levels of collagen and inflammatory cytokines regulated by the extracellular signal­regulated kinase (ERK) pathway. The potential effects of PDRN on skin regeneration were investigated. Fibroblast and keratinocyte proliferation and migration were analyzed using the water­soluble tetrazolium­8 and wound healing assays. The upregulation of collagen synthesis by PDRN­induced ERK activation was analyzed in fibroblasts with or without an ERK inhibitor. Inflammatory cytokine expression levels in keratinocytes were determined using reverse transcription­quantitative polymerase chain reaction. PDRN promoted the proliferation and migration of keratinocytes and fibroblasts. However, PDRN­induced ERK phosphorylation differed between keratinocytes and fibroblasts; PDRN increased ERK phosphorylation and collagen accumulation in fibroblasts, while it inhibited matrix metalloproteinase expression. By contrast, PDRN inhibited ERK phosphorylation in keratinocytes, and it decreased inflammatory cytokine expression levels. PDRN affects skin cell proliferation and migration, and collagen and inflammatory cytokine expression levels via ERK signaling. Overall, PDRN exerts a positive effect on skin regeneration, but the mechanism by which it promotes skin regeneration varies among different skin cell types.

Functional validation of co-culture model of human keratinocytes and neuronal cell line for sensitive skin by using transient receptor potential channel vanilloid subfamily member 1 antagonist.

BACKGROUND: Sensitive skin is a subjective cutaneous hyper-reactivity that occurs in response to various innocuous stimuli. Keratinocytes have recently been shown to participate in sensory transduction by releasing many neuroactive molecules that bind to intra-epidermal free nerve endings and modulate nociception. In the literature, the characterization of these interactions has been based on the co-culture of keratinocyte and mammalian-origin neuronal cell lines. In this study, we established an in vitro model based on a co-culture of primary human keratinocytes and differentiated SH-SY5Y cells, a human neuronal cell line. METHODS: Human epidermal keratinocytes and SH-SY5Y cells were monocultured and co-cultured. Changes in calcium influx, substance P, inflammatory cytokines, and neuropeptides between the monoculture and co-culture groups treated with capsaicin only and capsaicin with transient receptor potential channel vanilloid subfamily member 1 (TRPV1) antagonist, trans-4-tert-butylcyclohexanol (TTBC), together. In addition, the difference in stinging sensation was evaluated by applying it to the volunteers. RESULTS: When SH-SY5Y cells were co-cultured with keratinocytes, they had no significant effect on axonal development. Substance P was also released after capsaicin treatment and reduced by TTBC under co-culture conditions. Moreover, the expression of inflammatory cytokines and neuropeptides was significantly increased in co-cultured keratinocytes compared to that under monoculture conditions. In addition, the stinging sensation was significantly induced after the application of capsaicin in vivo and was relieved after the application of the TRPV1 antagonist. CONCLUSION: We demonstrated that the novel co-culture model is functionally valid through capsaicin and TRPV1 antagonist. We also confirmed that TTBC could be used for the treatment of sensitive skin through a co-culture model and in vivo tests. This co-culture model of keratinocytes and SH-SY5Y cells may be useful in vitro alternatives for studying the close communication between keratinocytes and neuronal cells and for screening therapeutic drugs for sensitive skin.

In-House Validation of an Efficient and Rapid Procedure for the Simultaneous Determination and Monitoring of 23 Mycotoxins in Grains in Korea.

A high-performance liquid chromatography tandem mass spectrometry method is described for the simultaneous determination of mycotoxins, including Ergot alkaloids (EAs), in 3 types of grains. The extraction of 23 mycotoxins was evaluated and performed by using a modified QuEChERS-based sample preparation procedure. The proposed method was fully validated on spiked grain samples (barley, wheat and oat) to assess the linearity, limit of detection (LOD) and limit of quantitation (LOQ), matrix effects, precision and recovery. After validation, this method was applied to 143 samples of various types of 3 grains from the Republic of Korea to survey the level of mycotoxin contamination in Republic of Korean grains. A total of 42 grain samples (29%) were contaminated with at least one of these mycotoxins at levels higher than the LOQ. The results demonstrated that the procedure was suitable for simultaneously determining these mycotoxins in cereals and could be performed for their routine analysis in mycotoxin laboratories.

Comparative study of treatment methods for benign lichenoid keratosis of the face.

Benign lichenoid keratosis is one of the most common skin lesions that develop on the faces of middle-aged women. This study aimed to find an effective treatment method for benign lichenoid keratosis. A total of 49 patients, who had a positive diagnosis during 2010-2018, were enrolled in the study. An Investigator's Global Assessment of the lesion was done using the 5-point visual analog scale to evaluate treatment efficacy. After excluding subjects who did not have a follow-up photograph, 38 subjects were given an Investigator's Global Assessment score. Combination therapy using laser and a topical agent was useful in the management of benign lichenoid keratosis on the face. Ablative laser was effective for immediate improvement of the lesion, whereas non-ablative laser was also useful and showed several benefits over ablative laser. Optimal treatment should be decided after considering the patient's preference, compliance with treatment regimen, and skin type.

The role of sonication in preparing injectable poly-l-lactic acid.

BACKGROUND: Injectable poly-l-lactic acid (PLLA) carries the risk of nodule or microlump formation. Various methods including sonication have been tried to minimize these adverse effects of PLLA. AIMS: This study investigated the change in size, distribution, and properties of PLLA particles after sonication, and the duration of sonication needed to reach the ideal particle size. METHODS AND MATERIALS: Two indicators, the average size of PLLA particles and diameter at 90%, were measured at each timepoint: at 0, 10, 60, 120, and 240 minutes of sonication. The characteristics and particle shape were assessed at 0 and 240 minutes. RESULTS: The average particle size and the diameter at 90% decreased drastically until 10 minutes of sonication and then increased slightly at 60 minutes. After 60 minutes, the average size and the diameter at 90% gradually decreased over time and reached 42.2 µm and 75.7 µm, respectively, at 120 minutes. After 240 minutes of sonication, the average particle size was 35.9 µm, much smaller than the smallest proper size required (40 µm). Standard deviation decreased gradually over time, which means that a more even distribution was obtained. Crystalline remnants were significantly less left with 120 minutes sonication compared to those with 120 minutes hydration only. PLLA particles were more cracked at the center, and microcrystals were more loosely distributed at the periphery after 120 minutes sonication. CONCLUSION: Sonication help reduce the average size of PLLA particles and achieve more even distribution. Therefore, we believe sonication may attribute to the safer use of PLLA.

Improvement of thermal and UV-light stability of ß-carotene-loaded nanoemulsions by water-soluble chitosan coating.

ß-Carotene is a vitamin A precursor and antioxidant with well-known health benefits; however, it is unstable and poorly soluble in water. In this study, ß-carotene-loaded nanoemulsions (BC-NEs) and water-soluble chitosan-coated BC-NEs (WSC-BC-NEs) were prepared to improve the stability of ß-carotene against high temperature and UV-light. WSC-BC-NEs were round droplets with two distinct layers and an average diameter of 218 nm and zeta potential of +40 mV. The thermal and UV light stability of the WSC-BC-NEs were improved compared to those of both free ß-carotene and BC-NEs. Free ß-carotene degraded readily during storage, particularly when exposed to high temperature and UV light. By contrast, the WSC-BC-NEs retained 82.0% of ß-carotene after 21 days of storage at 37 °C, and 77.6% after 21 days of UV light exposure (253 nm) at room temperature. Furthermore, compared with the BC-NEs, the WSC-BC-NEs improved the thermal stability of ß-carotene by about 45.1% after 21 days at 37 °C, and by 28.6% after 21 days of UV light exposure (253 nm). Therefore, the WSC-BC-NEs effectively increased the stability of the encapsulated ß-carotene, and show potential for application in the food and beverage industries.