1,721,030 research outputs found
Evaluating hair growth promoting effects of candidate substance: A review of research methods
No full textAndrogenetic alopecia (AGA) is the most common form of hair loss disorder. As the prevalence of AGA rises, the demand for AGA treatments is rising accordingly, prompting research to identify therapeutic candidates to treat AGA. Because AGA is caused by crosstalk among multiple hair follicle (HF) cell components, understanding the effects of candidate molecules on HF cells is essential to determining therapeutic candidates for treatment. To date, research has centered on HF dermal papilla and outer root sheath cells and has indicated that the hair growth effects of candidate substances may be mediated via alterations in several signaling pathways and signature genes in these HF cells. In more integrative evaluations, the HF unit is used as an ex vivo organ culture model to verify the effects of therapeutic candidates. Animal models have also been used to evaluate the effects of candidate substances. The main outcomes used to evaluate the effects of candidate substances are 1) changes in HF growth rates in vitro, 2) anagen induction capabilities, and 3) the effects of androgen modulation. This article reviews a series of methods used to evaluate the hair growth-promoting effects of candidate substances, providing an overview of cell assays, organs, and animal models used in AGA research in order to facilitate AGA research moving forward. (C) 2019 The Author(s). Published by Elsevier B.V. on behalf of Japanese Society for Investigative Dermatology.OAIID:RECH_ACHV_DSTSH_NO:T201906156RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079130CITE_RATE:3.675DEPT_NM:의학과EMAIL:[email protected]_YN:YY
Lichen Striatus: Clinical Features and Treatment Outcomes of Topical Agent Use in 60 Pediatric Patients
No full textBackground: Lichen striatus (LS) is a linear, inflammatory dermatosis that mainly affects children. To date, there are limited data comparing treatment outcomes between topical agents for pediatric LS. Objective: To investigate the clinical features and treatment outcomes associated with the use of topical agents for pediatric LS. Methods: We retrospectively reviewed the medical records and clinical photographs of 60 pediatric patients classified into three groups according to the topical agent used. Treatment response was evaluated by comparing subjective symptoms and clinical photographs obtained at each visit. Results: A good response (>75% clinical improvement from baseline) was achieved in 55%, 46.2%, and 42.9% of patients from the calcipotriol, corticosteroid, and calcineurin inhibitor groups, respectively. There were no statistically significant differences in treatment duration among groups. However, when compared to other drugs, calcipotriol showed a trend towards shortening the disease course duration. Conclusion: Topical use of calcipotriol, as well as corticosteroids and calcineurin inhibitors, may represent useful treatment options for pediatric LS, although further studies are required to confirm their efficacy and long-term safety. © 2020 Korean Dermatological Association. All rights reserved.N
Two-Cell Assemblage Assay: A Simple in vitro Method for Screening Hair Growth-Promoting Compounds
No full textAlopecia arises due to inadequate hair follicle (HF) stem cell activation or proliferation, resulting in prolongation of the telogen phase of the hair cycle. Increasing therapeutic and cosmetic demand for alleviating alopecia has driven research toward the discovery or synthesis of novel compounds that can promote hair growth by inducing HF stem cell activation or proliferation and initiating the anagen phase. Although several methods for evaluating the hair growth-promoting effects of candidate compounds are being used, most of these methods are difficult to use for large scale simultaneous screening of various compounds. Herein, we introduce a simple and reliable in vitro assay for the simultaneous screening of the hair growth-promoting effects of candidate compounds on a large scale. In this study, we first established a 3D co-culture system of human dermal papilla (hDP) cells and human outer root sheath (hORS) cells in an ultra-low attachment 96-well plate, where the two cell types constituted a polar elongated structure, named "two-cell assemblage (TCA)." We observed that the long axis length of the TCA gradually increased for 5 days, maintaining biological functional integrity as reflected by the increased expression levels of hair growth-associated genes after treatment with hair growth-promoting molecules. Interestingly, the elongation of the TCA was more prominent following treatment with the hair growth-promoting molecules (which occurred in a dose-dependent manner), compared to the control group (p < 0.05). Accordingly, we set the long axis length of the TCA as an endpoint of this assay, using a micro confocal high-content imaging system to measure the length, which can provide reproducible and reliable results in an adequate timescale. The advantages of this assay are: (i) it is physiologically and practically advantageous as it uses 3D cultured two-type human cells which are easily available; (ii) it is simple as it uses length as the only endpoint; and (iii) it is a high throughput system, which screens various compounds simultaneously. In conclusion, the "TCA" assay could serve as an easy and reliable method to validate the hair growth-promoting effect of a large volume of library molecules.Y
Acute stress-induced changes in follicular dermal papilla cells and mobilization of mast cells: Implications for hair growth
No full textBackground: Stress is a known cause of hair loss in many species. Objective: In this study, we investigated the role of acute stress on hair growth using a rat model. Methods: Rats were immobilized for 24 hours and blood samples, and skin biopsies were taken. The effect of stress-serum on the in vitro proliferation of rat and human dermal papilla cells (hDPCs), as well as serum cortisol and corticotropin-releasing hormone levels, were measured. Mast cell staining was performed on the biopsied tissue. In addition, Western blot and quantitative real time polymerase chain reaction were used to assess mast Cell tryptase and cytokine expression, respectively in rat skin biopsies. Results: Stress-serum treatment reduced significantly the number of viable hDPCs and arrested the cell cycle in the G1 phase, compared to serum from unrestrained rats (p< 0.05, respectively). Moreover, restrained rats had significantly higher levels of cortisol in serum than unrestrained rats (p<0.01). Acute stress serum increased mast cell numbers and mast cell tryptase expression, as well as inducing interleukin (IL)-6 and IL-1 beta a up-regulation. Conclusion: These results suggest that acute stress also has an inhibitory effect on hair growth via cortisol release in addition to substance P-mast cell pathway.N
A Receiver-Centric Transport Protocol for Mobile Hosts with Heterogeneous Wireless Interfaces
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Dissolving Candlelit Microneedle for Chronic Inflammatory Skin Diseases
No full textAbstract Chronic inflammatory skin diseases (CISDs) negatively impact a large number of patients. Injection of triamcinolone acetonide (TA), an anti‐inflammatory steroid drug, directly into the dermis of diseased skin using needle‐syringe systems is a long‐established procedure for treating recalcitrant lichenified lesions of CISDs, referred to as TA intralesional injection (TAILI). However, TAILI causes severe pain, causing patients to be stressed and reluctant to undergo treatment. Furthermore, the practitioner dependency on the amount and depth of the injected TA makes it difficult to predict the prognosis. Here, candle flame (“candlelit”)‐shaped TA‐loaded dissolving microneedles (Candlelit‐DMN) are designed and fabricated out of biocompatible and biodegradable molecules. Candlelit‐DMN distributes TA evenly across human skin tissue. Conjoined with the applicator, Candlelit‐DMN is efficiently inserted into human skin in a standardized manner, enabling TA to be delivered within the target layer. In an in vivo skin inflammation mouse model, Candlelit‐DMN inserted with the applicator effectively alleviates inflammation by suppressing inflammatory cell infiltration and cytokine gene expression, to the same extent as TAILI. This Candlelit‐DMN with the applicator arouses the interest of dermatologists, who prefer it to the current TAILI procedure
Hydrogen peroxide (H2O2) suppresses hair growth through downregulation of β-catenin
No full textOAIID:RECH_ACHV_DSTSH_NO:T201808213RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079130CITE_RATE:3.675DEPT_NM:의학과EMAIL:[email protected]_YN:YN
Photocurable pickering emulsion for colloidal particles with structural complexity
No full textWe prepared polymeric microparticles with coordinated patches using oil-in-water emulsion droplets which were stabilized by adsorbed colloidal polystyrene (PS) latex particles. The oil phase was photocurable ethoxylated trimethylolpropane triacrylate (ETPTA), and the particle-armored oil droplets were solidified by UV irradiation within a few seconds to produce ETPTA-PS composite microparticles without disturbing the structures. Large armored emulsion drops became raspberry-like particles, while small emulsion drops with a few anchored particles were transformed into colloidal clusters with well-coordinated patches. For high-molecular-weight PS particles with low chemical affinity to the ETPTA monomer, the morphology of the patchy particle was determined by the volume of the emulsion drop and the contact angle of the emulsion interface on the PS particle surface. Meanwhile, for low-molecular-weight PS particles with high affinity, the ETPTA monomers were likely to swell the adsorbed PS particles, and distinctive morphologies were induced during the shrinkage of emulsion drops and the phase separation of ETPTA from the swollen PS particles. In addition, colloidal particles with large open windows were produced by dissolving the PS particles from the patchy particles. We observed photoluminescent emission from the patchy particles in which dye molecules were dispersed in the ETPTA phase. Finally, we used Surface Evolver simulation to predict equilibrium structures of patchy particles and estimate surface energies which are essential to understand the underlying physics.This work was supported by a grant from
the Creative Research Initiative Program of the Ministry of
Science & Technology for “Complementary Hybridization of
Optical and Fluidic Devices for Integrated Optofluidic Systems”.
We also appreciate partial support from the Brain Korea 21
Program and thank Dr. Eric Lauga at MIT for the Surface Evolver
code
The effect of cilostazol, a phosphodiesterase 3 (PDE3) inhibitor, on human hair growth with the dual promoting mechanisms
No full textBackground: Cilostazol, a phosphodiesterase 3 (PDE3) inhibitor, increases the intracellular level of cyclic adenosine monophosphate to cause vasodilation. Topical application of cilostazol is reported to improve local blood flow and enhance wound healing; however, its effect on human hair follicles is unknown. Objective: The purpose of this study was to determine the effect of cilostazol on hair growth. Methods: We investigated the expression of PDE3 in human dermal papilla cells (DPCs), outer root sheath cells (ORSCs), and hair follicles. The effects of cilostazol on DPC and ORSC proliferation were evaluated using BrdU and WST-1 assays. The expression of various growth factors in DPCs was investigated by growth factor antibody array. Additionally, hair shaft elongation was measured using ex vivo hair follicle organ cultures, and anagen induction was evaluated in CS7BL/6 mice. Finally, the effects of cilostazol on vessel formation and activation of the mitogen-activated protein kinase pathway were evaluated. Results: We confirmed high mRNA and protein expression of PDE3 in human DPCs. Cilostazol not only enhanced the proliferation of human DPCs but also regulated the secretion of several growth factors responsible for hair growth. Furthermore, it promoted hair shaft elongation ex vivo, with increased proliferation of matrix keratinocytes. Cilostazol also accelerated anagen induction by stimulating vessel formation and upregulating the levels of phosphorylated extracellular signal-regulated kinase, c-Jun N-terminal kinase, and P38 after its topical application in C57BL/6 mice. Conclusion: Our results show that cilostazol promotes hair growth and may serve as a therapeutic agent for the treatment of alopecia. (C) 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.OAIID:RECH_ACHV_DSTSH_NO:T201808212RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A079130CITE_RATE:3.675DEPT_NM:의학과EMAIL:[email protected]_YN:YN
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