• Speech Sciences
• /
• v.12 no.2
• /
• pp.81-88
• /
• 2005

Electrodermal activity(EDA) is a bio-electric signal which occurs at the skin surface during the sweating. EDA reflects the activity of the sympathetic axis of the autonomic nervous system. EDA is associated with the eccrine sweat gland at the palmar and plamar surface. This study was aimed to characterize the relationship between EDA and auditory stimulus intensities. Acoustic stimulus used in this study were 500 Hz, 1 kHz, 2 kHz of narrow band noise, which were representative of speech frequencies in audible range. Stimulus intensity between 90 and 30 dB in 10 dB within dynamic range. After deriving the minimum stimulus intensity(threshold of skin potential) which elicited skin potential, and then the latency and amplitude were derived from waveform of skin potential, each latency and amplitude were compared to stimulus intensity. The waveform of skin potential were recorded stably, and the threshold of skin potential appeared nearly the hearing threshold level of the participant. The latency was decreased and the amplitude was increased according to the increase of the stimulus intensity. These results suggest that auditory evoked skin potential can be applicable to auditory assessment and audiological diagnosis tool.

• Textile Coloration and Finishing
• /
• v.20 no.6
• /
• pp.8-17
• /
• 2008

Poly (vinyl acetate) (PVAc) was used as a precursor of PVA/PVAc (skin/core) bicomponent. In order to investigate the possibility of PVA particles for electrical applications, PVA/PVAc particles were produced with an emulsifier, SDS (Sodium Dodecyl Sulfate) and an initiator, V-50 (2,2'-azobis(2-amidinopropane)digydrochloride). In this study, we investigated the electrical property of PVA/PVAc (skin/core) particles. The hydroxyl group of the PVA/PVAc (skin./core) was confirmed by the analysis of PVAc and PVA/PVAc (skin/core) using Fourier Transform Infrared Spectroscopy (FT-IR). The zeta-potential of the PVA/PVAc (skin/core) and PVAc has similarity; however, charge control agent (CCA) treated PVA/PVAc (skin/core) particles has lower zeta-potential than untreated PVA/PVAc particles. The zeta-potential (negative values) of the PVA/PVAc (skin/core) were enhanced in proportion to the increased concentration of CCA.

• The Journal of the Society of Korean Medicine Diagnostics
• /
• v.9 no.1
• /
• pp.131-135
• /
• 2005

Background and purpose: The measurement of direct current (DC) potential on skin area of meridian has recently been adopted to explore the electrophysiological characteristics of meridian system, But there exists two problems to be explained; the entity of the DC potential to be measured and the characteristics of electrode gel interface of measurement system, It is not clear whether the DC potential reflect, at least hypothetically, the entity of meridian, and if there exist any unstable factor in the DC potential measurement system. Methods: In this study, we designed an electronic circuit model of skin and applied known DC potential sources $({\pm}10.75mV,\;0mV)$ to the electrode interface of the skin model. Results: The result showed that the measured DC potential changed according to the time, and the same phenomenon was observed when the electrode gel was replaced with an electric condenser. It is suggested that the measurement of DC potential on electrode gel interface is very difficult and produces unstable values due to the capacity effect of electrode gel. Conclusion: Further studies on the DC potential evaluation in the context of meridian study should consider and bypass this problem.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.35 no.1
• /
• pp.1-9
• /
• 2009

South Asian's growing obsession with fair skin has made the cosmetic industry into a multibillion-dollar trade over the last decade alone. With reports of toxicity and potential mutagenicity of conventional skin lightening agents, cosmetic industries are looking for plant-based skin whitening formulations. In this review some potential depigmentation agents from South Asian region are discussed, including their historical background, biochemical characteristics and recent findings on their depigmenting activity.

• Herbal Formula Science
• /
• v.25 no.2
• /
• pp.123-134
• /
• 2017

Wounds are commonly created during almost every kind of surgery, trauma and skin diseases. Delayed wound healing affects a plenty of patients and requires prolonged treatments that seriously reduce the quality of life for patients. Skin damage involving large areas or great severity can lead to disability or even death. Wound healing involves a complicated series of actions, of various tissues and cell lineages, concerning inflammation, migration, proliferation, reepithelialization, and remodeling. Sopung-san is reported to have anti-inflammatory effect and has been used for various skin diseases such as allergic dermatitis and atopic dermatitis. In this study, the hypothesis that oral treatment with Sopung-san could enhances healing potential on rat full thickness skin wounds was tested. Twenty young male Sprague-Dawley rats were used for the studies. A full-thickness skin wound was made on the dorsal skin of the rats. Either Sopung-san water extract (SPS) or saline (Control) was orally administrated every day. The wound area was measured and the percentages of wound contraction, wound healed and wound epithelization were calculated. Wound tissue samples were excised following injection for histopathological and immunohistological examination. Wound area in rats of SPS group significantly was decreased compared to Control. SPS group showed significant promotion of wound healing compared to Cotrol group in the percentages of wound contraction, wound healed and wound epithelization. Histopathological examination revealed that SPS induces neo-vascularization potential in wound healing process. SPS treatment in rats significantly accelerated cutaneous wound healing in the neo-vascularization process by increasing VEGF and $TGF-{\beta}1$ synthesis. The results suggest that Sopung-san affects key cellular processes responsible for wound repair and point to a unique potential for this molecule in the therapy of skin wounds, particularly as an angiogenic agent.

• Biomolecules & Therapeutics
• /
• v.31 no.4
• /
• pp.388-394
• /
• 2023

Nitric oxide (NO) is a signaling molecule that plays a crucial role in numerous cellular physiological processes. In the skin, NO is produced by keratinocytes, fibroblasts, endothelial cells, and immune cells and is involved in skin functions such as vasodilation, pigmentation, hair growth, wound healing, and immune responses. NO modulates both innate and adaptive immune responses. As a signaling molecule and cytotoxic effector, NO influences the function of immune cells and production of cytokines. NO is a key mediator that protects against or contributes to skin inflammation. Moreover, NO has been implicated in skin sensitization, a process underlying contact dermatitis. It modulates the function of dendritic cells and T cells, thereby affecting the immune response to allergens. NO also plays a role in contact dermatitis by inducing inflammation and tissue damage. NO-related chemicals, such as nitrofatty acids and nitric oxide synthase (NOS) inhibitors, have potential therapeutic applications in skin conditions, including allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD). Further research is required to fully elucidate the therapeutic potential of NO-related chemicals and develop personalized treatment strategies for skin conditions.

• Reproductive and Developmental Biology
• /
• v.36 no.4
• /
• pp.283-290
• /
• 2012

Skin serves as an easily accessible source of multipotent stem cells with potential for cellular therapies. In pigs, stem cells from skin tissues of fetal and adult origins have been demonstrated as either floating spheres (cell aggregates) or adherent spindle-shaped mesenchymal stem cell (MSC)-like cells depending on culture conditions. The cells isolated from the epidermis and dermis of porcine skin showed plastic adherent growth in the presence of serum and positively expressed a range of surface and intracellular markers that are considered to be specific for MSCs. The properties of primitive stem cells have been observed with the expression of alkaline phosphatase and markers related to pluripotency. Further, studies have shown the ability of skin-derived MSCs to differentiate in vitro along mesodermal, neuronal and germ-line lineages. Moreover, preclinical studies have also been performed to assess their in vivo potential, and the findings appear to be effective in tissue regeneration at the defected site after transplantation. The present review describes the recent progress on the biological features of porcine skin-derived MSCs as adherent cells, and summarizes their potential in advancing stem cell based therapies.

• Toxicological Research
• /
• v.19 no.4
• /
• pp.285-291
• /
• 2003

The use of skin whitening agents has been recently increased in various kinds of cosmetic products, although there were some reports that whitening agents might cause allergic contact dermatitis. A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pigs for contact sensitization potential. This study was carried out to investigate the skin sensitization potential of three whitening agents, arbutin, azelaic acid, and kojic acid, by LLNA using a non-radiois-topic endpoint. Female Balb/c mice were exposed topically to a weak allergen, $\alpha$-hexylcinnamalde-hyde (HCA), and three whitening agents following LLNA protocol. Lymph node (LN) weight and cell proliferation in ears and auricular lymph node using bromodeoxyuridine (BrdU) immunohistochemistry were evaluated. LN weights were significantly increased at the HCA group compared to the vehicle control. A weak allergen, HCA elicited 3-fold or greater increase in cell proliferation of lymph nodes as well as increase in cell proliferation of ear as measured by BrdU immunohistochemistry. However, in the case of skin whitening agent groups, there were no significant changes in LN weight and cell proliferation in the ear and lymph node of mice treated with 5, 10 and 20% of three whitening agents compared to the vehicle control. These results show that these three skin whitening agents may not have contact sensitization potentials at tested concentrations in Balb/c mice by LLNA.

• Toxicological Research
• /
• v.26 no.1
• /
• pp.9-14
• /
• 2010

The evaluation of eye and skin irritation potential is essential to ensuring the safety of human in contact with a wide variety of substances. Despite this importance of irritation test, little is known with respect to the irritation potency of lomefloxacin, a fluoroquinolone antibiotic, which has been known to cause phototoxicity with an abnormal reaction of the skin. Thus, to investigate the tendency of lomefloxacin to cause eye and skin irritation, we carried out in vitro eye irritation test using Balb/c 3T3, and in vitro skin irritation test using $KeraSkin^{TM}$ human skin model system. 3T3 neutral red uptake assay has been proposed as a potential replacement alternative for the Draize Eye irritation test. In this study, the $IC_{50}$ value obtained for lomefloxacin was 375 ${\mu}g$. According to the classification model used for determining in vitro categories, lomefloxacin was classified as moderately irritant. For evaluation of skin irritation, engineered epidermal equivalents ($KeraSkin^{TM}$) were subjected to 10 and 25 mg of lomefloxacin for 15 minutes. Tissue damage was assessed by tissue viability evaluation, and by the release of a pro-inflammatory mediator, interleukin- 1${\alpha}$. Lomefloxacin increased the interleukin-1${\alpha}$ release after 15 minutes of exposure and 42 hours of post incubation, although no decrease in viability was observed. Therefore, lomefloxacin is considered to be moderately irritant to skin and eye.

• Genomics & Informatics
• /
• v.21 no.3
• /
• pp.43.1-43.13
• /
• 2023

Melanin is synthesized by tyrosinase to protect the skin from ultraviolet light. However, overproduction and accumulation of melanin can result in hyperpigmentation and skin melanoma. Tyrosinase inhibitors are commonly used in the treatment of hyperpigmentation. Natural tyrosinase inhibitors are often favoured over synthetic ones due to the potential side effects of the latter, which can include skin irritation, allergies, and other adverse reactions. Nuciferine, an alkaloid derived from Nelumbo nucifera, exhibits potent antioxidant and anti-proliferative properties. This study focused on the in silico screening of nuciferine for anti-tyrosinase activity, using kojic acid, ascorbic acid, and resorcinol as standards. The tyrosinase protein target was selected through homology modeling. The residues of the substrate binding pocket and active site pockets were identified for the purposes of grid box optimization and docking. Therefore, nuciferine is a potent natural tyrosinase inhibitor and shows promising potential for application in the treatment of hyperpigmentation and skin melanoma.