Continuous organelle separation in an insulator-based dielectrophoretic device.

Heterogeneity in organelle size has been associated with devastating human maladies such as neurodegenerative diseases or cancer. Therefore, assessing the size-based subpopulation of organelles is imperative to understand the biomolecular foundations of these diseases. Here, we demonstrated a ratchet migration mechanism using insulator-based dielectrophoresis in conjunction with a continuous flow component that allows the size-based separation of submicrometer particles. The ratchet mechanism was realized in a microfluidic device exhibiting an array of insulating posts, tailoring electrokinetic and dielectrophoretic transport. A numerical model was developed to elucidate the particle migration and the size-based separation in various conditions. Experimentally, the size-based separation of a mixture of polystyrene beads (0.28 and 0.87 µ$\umu $ m) was accomplished demonstrating good agreement with the numerical model. Furthermore, the size-based separation of mitochondria was investigated using a mitochondria mixture isolated from HepG2 cells and HepG2 cells carrying the gene Mfn-1 knocked out, indicating distinct size-related migration behavior. With the presented continuous flow separation device, larger amounts of fractionated organelles can be collected in the future allowing access to the biomolecular signature of mitochondria subpopulations differing in size.

What type of face mask should we choose in coronavirus disease 2019 pandemic considering photoprotective effectiveness?

BACKGROUND: Wearing a face mask is one of the most effective personal protective strategies to diminish the spread of coronavirus disease 2019 (COVID-19). Several dermatological outcomes were reported because of the prolonged use of face masks, especially due to the constant mask-on policy, but the photoprotective effect of face masks has received less attention. OBJECTIVE: The aim of this study was to provide guidance in the use of face masks by comparing the photoprotective effects of routinely used masks. METHODS: A total of 12 frequently used face masks were tested, including certified respirators, Korea filter (KF)94, KF-anti-droplet (KF-AD), and KF80. The amount of light that penetrates each face mask was measured using a light sensor that can quantify Ultraviolet A (UVA), visible light (VL), and infrared A (IR-A) rays. RESULTS: Black-colored KF94 masks and surgical masks reduced penetration of UVA, VL, and IR-A by approximately 100%. The UVA penetration decreased on average by 95.51%, 90.97%, 85.06%, and 86.41% with white-colored KF94, KF-AD, KF80, and surgical masks, respectively. The VL and IR-A were blocked by approximately 75.58%, 66.16%, 59.18%, and 64.48% with white-colored KF94, KF-AD, KF80, and surgical masks, respectively. CONCLUSION: In conclusion, the different photoprotective effectiveness of face masks was mainly determined by colors, and therefore, black-colored, multi-layered respirators can be recommended in terms of photoprotection in the COVID-19 pandemic. The quantified comparative results will be helpful to the person with pre-existing photo-aggravated dermatosis, especially in the season of the high intensity of sunlight.

Impact of COVID-19 on Clinicopathological Spectrum of Pityriasis Rosea in Korea.

BACKGROUND: Pityriasis rosea (PR) is a papulosquamous eruption with generally unknown origin but suspected to be related to viral etiologies. The clinicopathological spectrum of several disorders with viral etiologies has been altered after the coronavirus disease 2019 (COVID-19) pandemic. The author group could experience coherent histological alterations in PR after the COVID-19 pandemic. This study aimed to investigate how the clinicopathological findings of PR were changed after the COVID-19 pandemic. METHODS: Patients (n = 11) diagnosed with PR based on the clinical manifestations and skin biopsies between February 2018 and October 2019 and 11 patients in February 2020 and October 2021 were retrospectively analyzed by investigating the medical records. RESULTS: The patients with PR during the COVID-19 pandemic demonstrated statistically significant histopathological alterations from classic brisk and dense infiltration pattern to dormant and sparse infiltration and psoriasiform-dominant patterns (P = 0.019). PR was associated with more frequent pruritus during the pandemic period (P = 0.027). CONCLUSION: In conclusion, PR demonstrated a significant histopathological alteration with more frequent pruritus during the COVID-19 pandemic. The comparative results about clinicopathological findings of PR will provide a useful reference for dermatologists in the diagnostic process of PR in the COVID-19 pandemic.

Complications of Nasopharyngeal Swabs and Safe Procedures for COVID-19 Testing Based on Anatomical Knowledge.

Nasopharyngeal swabs have been widely to prevent the spread of coronavirus disease 2019 (COVID-19). Nasopharyngeal COVID-19 testing is a generally safe and well-tolerated procedure, but numerous complications have been reported in the media. Therefore, the present study aimed to review and document adverse events and suggest procedural references to minimize preventable but often underestimated risks. A total of 27 articles were selected for the review of 842 related documents in PubMed, Embase, and KoreaMed. The complications related to nasopharyngeal COVID-19 testing were reported to be rarely happened, ranging from 0.0012 to 0.026%. Frequently documented adverse events were retained swabs, epistaxis, and cerebrospinal fluid leakage, often associated with high-risk factors, including severe septal deviations, pre-existing skull base defects, and previous sinus or transsphenoidal pituitary surgery. Appropriate techniques based on sufficient anatomical knowledge are mandatory for clinicians to perform nasopharyngeal COVID-19 testing. The nasal floor can be predicted by the line between the nostril and external ear canal. For safe testing, the angle of swab insertion in the nasal passage should remain within 30° of the nasal floor. The swab was gently inserted along the nasal septum just above the nasal floor to the nasopharynx and remained on the nasopharynx for several seconds before removal. Forceful insertion should be attempted, and alternative examinations should be considered, especially in vulnerable patients. In conclusion, patients and clinicians should be aware of rare but possible complications and associated high-risk factors. The suggested procedural pearls enable more comfortable and safe nasopharyngeal COVID-19 testing for both clinicians and patients.

A simple morphometric analysis method for dermal microstructure using color thresholding and moments.

BACKGROUND: Proper assessment of dermal collagen fibers by dermatologists and researchers is essential. Histologic evaluation methods have limitations. We present a simple method for measurement of collagen fibers in human skin using Masson's trichrome staining. MATERIALS AND METHODS: Normal skin specimens from a cadaver were processed with Masson's trichrome, which can effectively stain collagen fibers blue with aniline dye. Optical photomicrographs of these slides were analyzed using ImageJ software. Color image processing, a histogram-based function of ImageJ for image segmentation, was performed with color moments thresholding technique. We selected blue areas by adjusting the blue channel to include specific values. The selected areas were highlighted and evaluated. We divided the image into layers of 0.09-mm2 areas from the top to bottom of the dermis. Each area was cropped and evaluated. RESULTS: Quantitative assessment yielded the quantitative size occupied by collagen fibers in an area of 0.09 mm2 . Calculation of the percentage in each area can be used to determine the density of collagen fibers. CONCLUSION: Measurements obtained with our method can be applied to research on dermal collagen fibers. We present a convenient quantitative assessment method for the dermal constituents in Masson's trichrome-stained slides.

An assessment method for dermal structures using cross-polarized light imaging with a green light-emitting diode.

BACKGROUND: Several experimental methods for evaluating dermal structures exist; however, most of these are not used in dermatology clinics because of cost and functional limitations. OBJECTIVE: To propose a simple, non-invasive method for dermal structure evaluation using a green light-emitting diode (LED) with cross-polarized light (CPL) imaging and compare the quality of the images taken using either green or white LED. MATERIALS AND METHODS: Skin specimens were taken from fifteen cadavers. Images were captured using CPL photography with a green or white LED. The Commission International d'Eclairage L*a*b* (CIELAB) values were calculated for each image. The skin specimens were processed and stained with Masson's trichrome to visualize collagen fibers with major image scattering. The images were histologically analyzed, and correlational and regression analyses were performed to determine the relationship between the L* values and histologic measurements. RESULTS: The L* values for the green images were positively correlated with collagen fiber density, reticular collagen bundle diameter, and dermal thickness. They were effective for estimating dermal properties. The L* values for the white images were positively correlated with reticular collagen bundle diameter and dermal thickness. Correlational coefficients for white images were lower than those for green images. In regression analysis, green images showed a higher coefficient of determination (R2 ) for predicting reticular collagen bundle diameter than white images (0.1128 vs. 0.0827). CONCLUSION: Cross-polarized light imaging with a green LED is a simple, non-invasive method for evaluating dermal structures. The use of a green LED was also more effective for image analysis.

Degenerative Calcification of Pericardial Bioprostheses: Comparison of Five Implantation Methods in a Rabbit Model.

BACKGROUND AND AIM OF THE STUDY: The degenerative calcification of bioprosthetic heart valves remains a clinical challenge, especially among young adults and children. Animal models that are based on subcutaneous and intramuscular implantation and are typically used to assess interventions to prevent bioprosthetic heart valve calcification do not reflect actual hemodynamic stress and lack direct blood contact. Thus, the study aim was to investigate bioprosthesis calcification at different implantation sites. METHODS: The calcification degrees of five valve implantation methods, namely subcutaneous, intramuscular and intravenous implantation, and arterial and venous patch angioplasty, were simultaneously investigated in 10 New Zealand White rabbits. RESULTS: Ultrasonography and computed tomography images showed vascular patency to be well maintained in all implanted vessels. Histologically, cellular infiltrates around the implant and within the collagen fibers were only found in the intravenous implantation group, which also had the highest calcium level among the methods. CONCLUSION: The present study was the first to compare the degree of calcification after applying five implantation methods simultaneously in one animal species. The rabbit intravenous implantation model, which involved direct contact with blood factors, is expected to serve as a useful animal model for research into the prevention of bioprosthetic heart valve degeneration.

3D reconstruction of skin pathological tissue: the understanding of microrelief pattern and dermal ridge.

AIM: Most studies about the structures of the human skin have been on the general histologic features of the skin. The purpose of this study was to understand the relationship between the microrelief (MR) pattern and histologic structure of the human skin, and to find the usefulness of the three-dimensional reconstruction (3DR) technique of pathological skin tissue. MATERIALS, SUBJECTS, AND METHODS: Human skin specimens were obtained from the medial forearm, abdomen, and volar aspects of the finger tips of cadavers. Two-dimensional surface-viewed images of the skin showing MR patterns were obtained using dry dermoscopy. Histologic structures of the skin were evaluated by 3D images obtained using the 3DR technique. RESULTS: MR was deeper and wider in the abdomen than in the medial side of the forearm. In the medial side of the forearm, 10.27 rete ridges were distributed in a plateau, on average. In the abdomen, about 14.37 rete ridges were distributed in a plateau. From 3DR technique, MR pattern thought to be a superordinate concept to rete ridges. CONCLUSION: The 3DR technique was useful and may allow a better understanding of the pathogenetic changes in the skin surface in aging skin.

A comparison of the scar prevention effect between carbon dioxide fractional laser and pulsed dye laser in surgical scars.

BACKGROUND: The use of ablative lasers based on the fractional approach is a novel strategy for the treatment of postoperative and acne scars in addition to wrinkles. OBJECTIVE: To evaluate and compare the efficacy of carbon dioxide ablative fractional laser (AFL) and the pulsed dye laser (PDL) for the improvement of surgical scars. MATERIALS AND METHODS: Fourteen Korean patients with surgical scars were enrolled for this study. Half of each scar was treated with a 10,600-nm AFL and the contralateral half with the 595-nm PDL. For early intervention of the postoperative scar, the laser treatments were begun after 2 weeks from the Mohs micrographic surgery. RESULTS: Both PDL and AFL produced statistically significant improvements. However, comparatively, there was no statistical difference between them. In each variable, AFL was more effective than PDL in the improvement of pliability and thickness. In contrast, PDL was superior to AFL in the improvement of vascularity and pigmentation. CONCLUSION: Pulsed dye laser and AFL treatments for surgical scar provide significant improvement. Pulsed dye laser was more effective in color of scar compared with AFL, which showed marked improvement in the contour of scar. Overall improvement was not statistically different in the Vancouver Scar Scale.

Clinical effectiveness of non-invasive selective cryolipolysis.

BACKGROUND: Excess subcutaneous fat causes not only cosmetic issues, but also substantial systemic health problems. Cryolipolysis has been reported to provide non-invasive fat reduction that significantly reduces subcutaneous fat cells with controlled, localized cooling. OBJECTIVE: This study is intended to determine whether a cryolipolysis device can effectively reduce subcutaneous fat without damaging the overlying skin or causing significant side effects and ultimately produce improved cosmetic results. MATERIALS AND METHODS: A total of 15 patients participated in this study and they were treated unilaterally in a split-body trial manner with a non-invasive cryolipolysis device (Micool(™), Hironic Co., Seongnam, Korea). The degree of improvement was assessed by both objective and subjective assessments. Complications and side effects were recorded at every visit. RESULTS: The results of both objective and subjective assessments showed significant improvements in subcutaneous fat reduction without any meaningful complications. CONCLUSION: Non-invasive selective cryolipolysis has been reported to be a safe and effective treatment modality for the reduction of excess adipose tissue. Therefore, cryolipolysis is a promising technology that could be an appropriate and safe therapeutic option for subcutaneous fat reduction.

Dystrophic calcifications after autologous fat injection on face.

Autologous fat injection is widely used procedure for various functional and aesthetic purposes. However, it could result in many immediate or delayed complications including dystrophic calcifications. Almost all of the case reports about dystrophic calcification after autologous fat injection were result from the iatrogenic tissue trauma of breast augmentation. This is a report of a 30-year-old patient who developed pathologically proven multiple dystrophic calcifications on the face after autologous fat injection.

Efficacy of Bleomycin Intralesional Injection for Treating Digital Mucous Cysts: A Comparative Study of Corticosteroid Intralesional Injection and Surgical Excision.

BACKGROUND: Sclerotherapy has shown superior efficacy among the nonsurgical options for managing digital mucous cysts (DMC). Notably, previous research has indicated that bleomycin offers a more favorable side-effect profile and similar efficacy to conventional sclerosing agents. OBJECTIVE: This study aimed to assess the efficacy and safety of bleomycin intralesional injection (ILI) for treating DMC through a comparative analysis of corticosteroid ILI and surgical excision. METHODS: We retrospectively reviewed electronic medical records and clinical photographs. Telephone interviews were conducted to further investigate long-term treatment efficacy, safety, and overall treatment satisfaction. RESULTS: Ten patients underwent surgical excision, and 13 and 15 patients received bleomycin and corticosteroid ILI, respectively. Both surgical excision and bleomycin ILI demonstrated superior treatment efficacy compared to corticosteroid ILI. No statistically significant difference in the treatment effectiveness between surgical excision and bleomycin ILI was observed. No significant adverse effects were observed. In the survey, the level of satisfaction was the highest for bleomycin ILI, followed by surgical excision and corticosteroid ILI. CONCLUSION: This study revealed that bleomycin ILI exhibits a treatment efficacy higher than that of corticosteroid ILI and slightly lower than that of surgical excision, without any side effects. Therefore, bleomycin ILI is a safe and effective therapeutic option for the treatment of DMC.

Recalcitrant cutaneous ulcer of comorbid patient treated with platelet rich plasma: a case report.

The platelet-rich plasma (PRP) has been advocated as a way to introduce increased concentrations of growth factors and other bioactive molecules to injured tissues in an attempt to optimize the local healing environment. A 94-yr-old woman with various comorbidities presented with a two-week history of severe cutaneous ulcer on the left dorsum of foot. It was caused by recurrent mechanical trauma and did not respond to several wound debridement and simple dressings. However, after she was completed on seven times of autologous PRP treatments, we observed complete healing of the skin lesion within 3 months. Herein, we report a case of recalcitrant cutaneous ulcer with various comorbidities and discuss about the promising possibility of autologous PRP as an effective alternative therapeutic modality.

Three-dimensional imaging for the analysis of human epidermal melanocytes.

Three-dimensional (3-D) analysis of human epidermal melanocytes is required for deeper understanding of melanocytic disorders. The purpose of this study was to standardize 3-D imaging and quantification for the evaluation of epidermal melanocytes. The epidermal specimen was obtained using the suction blister method from a patient with melanocytic nevus on the forearm skin. Cutaneous ACT-PRESTO, the tissue-clearing and labeling technique, was subsequently performed. With the 3-D image analysis program, morphological reconstruction and quantification of selected perilesional and melanocytic nevus areas were possible. The region of melanocytic nevus showed higher numbers of total melanocytic dendrites and similar numbers of cell bodies compared with perilesional area. In addition, the mean area and volume of cell bodies increased in the melanocytic nevus area compared with the results in the perilesional area. The 3-D evaluation method of human epidermal melanocytes can be applied to investigate novel pathologies related to hyper- or hypo-pigmentary disorders.

MAX: a simple, affordable, and rapid tissue clearing reagent for 3D imaging of wide variety of biological specimens.

Transparency of biological specimens is crucial to obtaining detailed 3-dimensional images and understanding the structure and function of biological specimens. This transparency or tissue clearing can be achieved by adjusting the refractive index (RI) with embedding media and removing light barriers such as lipids, inorganic deposits, and pigments. Many currently available protocols consist of multiple steps to achieve sufficient transparency, making the process complex and time-consuming. Thus, in this study, we tailored the recipe for RI adjustment media named MAX based on the recently reported MACS protocol to achieve a single-step procedure, especially for ECM-rich tissues. This was achieved by the improvement of the tissue penetrability of the RI-matching reagent by combining MXDA with sucrose or iodixanol. While this was sufficient for the 3D imaging in many applications, MAX can also be combined with modular processes for de-lipidation, de-coloration, and de-calcification to further maximize the transparency depending on the special features of the tissues. Our approach provides an easy alternative for tissue clearing and 3D imaging.

Whole structural reconstruction and quantification of epidermal innervation through the suction blister method and skin-clearing technique.

Three-dimensional (3-D) analysis of intraepidermal nerve fibers (IENFs) is conducted to advance assessment methods for peripheral neuropathies and pruritic skin disorders. The skin-clearing technique was proven to be a reliable method for 3-D imaging of IENFs. Nonetheless, it still requires further improvement in the imaging process. The aim of this study was to standardize the 3-D evaluation method of IENFs and to suggest promising 3-D biomarkers for clinical application. A total of nine healthy individuals were prospectively enrolled. The newly adopted suction blister method was combined with the tissue-clearing technique. The detailed structure of the IENFs was reconstructed and quantified using the neuron tracing software. The suction blister method showed improved linear integrity of IENFs compared with those obtained from the previously used salt-split skin test. The 3-D parameters most significantly related to natural aging were the convex hull two-dimensional perimeter and the total length (both p = 0.020). The meaningful correlations were followed by total volume (p = 0.025), ends (p = 0.026), convex hull 3-D surface, and complexity (both p = 0.030). Thus, the 3-D parameters could be utilized as possible biomarkers to identify ambiguous pathologies of peripheral neuropathies and pruritic skin disorders.

Monitoring Wound Healing with Topically Applied Optical NanoFlare mRNA Nanosensors.

An effective wound management strategy needs accurate assessment of wound status throughout the whole healing process. This can be achieved by examining molecular biomarkers including proteins, DNAs, and RNAs. However, existing methods for quantifying these biomarkers such as immunohistochemistry and quantitative polymerase chain reaction are usually laborious, resource-intensive, and disruptive. This article reports the development and utilization of mRNA nanosensors (i.e., NanoFlare) that are topically applied on cutaneous wounds to reveal the healing status through targeted and semi-quantitative examination of the mRNA biomarkers in skin cells. In 2D and 3D in vitro models, the efficacy and efficiency of these nanosensors are demonstrated in revealing the dynamic changes of mRNA biomarkers for different stages of wound development. In mouse models, this platform permits the tracking and identification of wound healing stages and a normal and diabetic wound healing process by wound healing index in real time.

Co-flow injection for serial crystallography at X-ray free-electron lasers.

Serial femtosecond crystallography (SFX) is a powerful technique that exploits X-ray free-electron lasers to determine the structure of macro-molecules at room temperature. Despite the impressive exposition of structural details with this novel crystallographic approach, the methods currently available to introduce crystals into the path of the X-ray beam sometimes exhibit serious drawbacks. Samples requiring liquid injection of crystal slurries consume large quantities of crystals (at times up to a gram of protein per data set), may not be compatible with vacuum configurations on beamlines or provide a high background due to additional sheathing liquids present during the injection. Proposed and characterized here is the use of an immiscible inert oil phase to supplement the flow of sample in a hybrid microfluidic 3D-printed co-flow device. Co-flow generation is reported with sample and oil phases flowing in parallel, resulting in stable injection conditions for two different resin materials experimentally. A numerical model is presented that adequately predicts these flow-rate conditions. The co-flow generating devices reduce crystal clogging effects, have the potential to conserve protein crystal samples up to 95% and will allow degradation-free light-induced time-resolved SFX.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Cholic Acid (MT921) after a Subcutaneous Injection in the Submental Area to Humans.

This study aimed to explore pharmacokinetics, pharmacodynamics, and safety/tolerability of MT921, an injectable cholic acid, after a single subcutaneous administration to healthy volunteers. A randomized, double-blinded, placebo-controlled, single dose-ascending phase 1 study enrolled 24 subjects who were assigned to three groups (60 mg, 120 mg, and 150 mg) of MT921. Blood samples were obtained for a 24-h period before and after injecting MT921 to the submental fat area. Plasma concentrations of cholic acid and deoxycholic acid were determined for pharmacokinetic analysis. Levels of free fatty acid, triglyceride, and total cholesterol were measured for pharmacodynamic analysis. Safety and tolerability were assessed until 21 days post-dose. While systemic exposure to cholic acid tended to increase as the MT921 dose increased, pharmacokinetic profiles of deoxycholic acid were similar among dose groups without showing significant changes. Pharmacodynamic profiles were comparable when measured at baseline and post-dose. The most frequent adverse events were injection site pain and edema. All adverse drug reactions resolved without treatment. MT921 appeared to be well-tolerated after an injection to the submental area at a dose up to 150 mg. Systemic exposure to cholic acid increased as the dose increased. Blood lipid profiles and deoxycholic acid levels were not affected by MT921 treatment.