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.

Development of a method for analysis and risk assessment of residual pesticides in ginseng using liquid and gas chromatography-tandem mass spectrometry

In this study, we developed a method for detecting 335 pesticides in ginseng using liquid chromatography quadrupole mass spectrometry (LC-MS/MS) and gas chromatography quadrupole mass spectrometry (GC-MS/MS). Additionally, the linearity, sensitivity, selectivity, accuracy, and precision of the method was validated. The limits of detection (LOD) and limits of quantification (LOQ) for the instrument used in these experiments was 0.1-5.8 μg/kg and 0.3-17.5 μg/kg, respectively. The average recovery was 71.6-113.4%. From 2016 to 2019, 467 ginseng samples were analyzed, of which 304 samples detected pesticide residues, but most of them were below the standard. It can be observed that the hazard quotient (HQ) of ginseng for detected pesticides was less than 1, thus implying that the risk was low. Hence, in this study, we developed a specific, reliable, and suitable method for a fast and simultaneous analysis of 335 pesticides in ginseng.

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

Polydeoxyribonucleotide (PDRN) is a mixture of deoxyribonucleotides. It serves as an anti‑inflammatory and tissue‑regenerating agent. The mitogen‑activated 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 signal‑regulated kinase (ERK) pathway. The potential effects of PDRN on skin regeneration were investigated. Fibroblast and keratinocyte proliferation and migration were analyzed using the water‑soluble tetrazolium‑8 and wound healing assays. The upregulation of collagen synthesis by PDRN‑induced ERK activation was analyzed in fibroblasts with or without an ERK inhibitor. Inflammatory cytokine expression levels in keratinocytes were determined using reverse transcription‑quantitative polymerase chain reaction. PDRN promoted the proliferation and migration of keratinocytes and fibroblasts. However, PDRN‑induced 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.

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.

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 to 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. This article is protected by copyright. All rights reserved.

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.

Post-thaw viable CD34(+) cell count is a valuable predictor of haematopoietic stem cell engraftment in autologous peripheral blood stem cell transplantation

BACKGROUND AND OBJECTIVES

In peripheral blood stem cell transplantation, the number of CD34(+) cells infused is considered a predictor of haematopoietic engraftment. However, the currently accepted minimal threshold of CD34(+) cells/kg was determined by counting CD34(+) cells before freezing, and the loss of viable CD34(+) cells during freezing, cryopreservation or thawing prior to reinfusion has not been assessed.

MATERIALS AND METHODS

Total and viable CD34(+) cells were quantified using single platform flow cytometry and viability dye, 7-amino actinomycin D (7-ADD), at the time of collection and prior to reinfusion in 46 peripheral haematopoietic stem cell grafts from 36 patients. The time to engraftment of neutrophil and platelet was assessed by routine peripheral blood cell counts performed daily.

RESULTS

The median number of viable CD34(+) cells harvested was 3.6 x 10(6)/kg (range 0.05-21.2), and the median viability was 98% (range 70-100%) before freezing. After thawing, the median number of viable CD34(+) cells was reduced to 2.2 x 10(6)/kg (range 0.04-14.8) and the median viability was reduced to 71% (range 31-89%). The number of viable CD34(+) cells/kg before freezing and after thawing significantly correlated with engraftment of neutrophils (P < 0.0001 both) and platelets (P = 0.007 and 0.006, respectively). Although the minimum dose for engraftment (2.0 x 10(6) CD34(+) cells/kg) was harvested in 37 of 46 cases (85%), only 25 cases (54%) met this threshold at the time of reinfusion. For platelet engraftment, determination of viable CD34(+) cells prior to reinfusion was more important than enumeration at the time of collection.

CONCLUSION

Quantification of post-thaw viable CD34(+) cells better represents the actual composition of the graft and may be a more accurate predictor of haematopoietic engraftment than post-thaw total CD34(+) cell counts, or prefreeze determinations, especially for platelet engraftment. It is necessary to develop good quality controls for freezing and thawing procedures to minimize variance in cell viability.

Influence of air exposure and storage condition on serum ionized magnesium level

The aim of this study was to evaluate whether reporting serum level of ionized magnesium (iMg) is appropriate when affected by various conditions such as exposure to air and delayed measurement. Serum levels of pH, iMg and normalized magnesium (nMg, normalized or adjusted concentration of iMg to pH 7.40) from 28 inpatients were measured at intervals of 3 min after exposing the samples to air at room temperature. Serum from 30 inpatients was stored in closed tubes at 4 degrees C and -20 degrees C and iMg and nMg levels were measured after 2 days. It was found that serum iMg and nMg concentrations exposed to air were decreased by 0.0023 mmol/l and 0.0001 mmol/l per minute, respectively. nMg did not display any significant changes compared with iMg at 0 min, whereas iMg showed significant changes, which exceeded between-day precision. For the stored serum, only iMg of serum at -20 degrees C showed no statistically significant changes (p = 0.169). It is concluded that to report the result as iMg, the sample should be kept anaerobically, and if exposed to air, the result should be reported as nMg. For storage, iMg of serum kept anaerobically at -20 degrees C is reliable.

Changes in enzyme activity and expression of DHFR of Toxoplasma gondii by antifolates

The responses to antifolates of Toxoplasma gondii were investigated by measuring the dihydrofolate reductase (DHFR) activity, quantity of DHFR mRNA, and single-strand conformational polymorphism (SSCP) pattern. Pyrimethamine (PYM) and methotrexate (MTX) were tested as antifolates. When T. gondii was treated with PYM, the viability was decreased by the increasing concentration of PYM, DHFR activity tended to increase as the passage proceeded, and the quantity of mRNA expressed was also increased according to passages. The viability of T. gondii was decreased by the increasing concentration of MTX, but it was maintained over 40% up to 100 microM MTX. DHFR activity was 77.4% in the 1st passage (1 microM). 82.2% in the 4th passage (10 microM), and 141.3% in the 7th passage (100 microM). But no changes were detected in SSCP pattern of T. gondii exposed to PYM and MTX, both. These results suggested that the response of T. gondii to PYM was regulated by transcriptional level and that, in MTX, the viability of T. gondii was derived from increasing DHFR activity.

Analysis of antigenic domain of GST fused major surface protein (p30) fragments of Toxoplasma gondii

Antigenic domain of major surface protein (p30) of Toxoplasma gondii was analyzed after polymerase chain reaction (PCR) of its gene fragments. Hydrophilic or hydrophobic moiety of amino acid sequences were expressed as glutathione S-transferase (GST) fusion proteins. Fragments of p30 gene were as follows: T37, total p30 open reading frame (ORF); S28, total ORF excluding N-terminal signal sequence and C-terminal hydrophobic sequence: A19, N-terminal 2/3 parts of S28; P19, C-terminal 2/3 of S28; X9, N-terminal 1/3 part of S28; Y10, middle 1/3 of S28; and Z9, C-terminal 1/3 of S28, respectively. Primer of each fragment was synthesized to include clamp sequence of EcoR I restriction site. PCR amplified DNA was inserted into GST (26 kDa) expression vector, pGEX-4T-1 to transform into Escherichia coli (JM105 strain). GST fusion proteins were expressed with IPTG induction as 63, 54, 45, 45, 35, 36, and 35 kDa proteins measured by SDS-PAGE. Each fusion protein was confirmed with GST detection kit. Western blot analysis with the serum of a toxoplasmosis patient revealed antigenicity in proteins expressed by T37, S28, and A19 but not those by P18, X9, Y10, and Z9. Antigenicity of p30 seems to be located either in N-terminal 1/3 part in the presence of middle 1/3 part or in the oligopeptides between margins of the first and second 1/3 parts.

Lymphadenitis in experimental murine toxoplasmosis induced by intramuscular injection of tachyzoites

When tachyzoites (RH strain) of Toxoplasma gondii are injected intramuscularly, experimental mice survive up to 7 days, 1-2 days longer than those infected intraperitoneally. We observed sequential histopathological changes in inguinal lymph nodes after intramuscular injection of tachyzoites to thighs of specific pathogen free (SPF) mice. Initial findings on 1 or 3 days after the injection were reactive germinal centers, distended sinuses and epithelioid cell clusters in cortical and paracortical regions. Later on 5 days after the injection, however, effacement of nodal structure with depletion of cells and focal necrosis were observed. Necrotizing lymphadenitis in the experimental murine toxoplasmosis suggests the causal relation between T. gondii infection and the human disease.