يعرض 1 - 10 نتائج من 51 نتيجة بحث عن '"Dermatology & Venereal Diseases"', وقت الاستعلام: 0.70s تنقيح النتائج
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    المصدر: Lasers in Surgery and Medicine. 53:1413-1426

    الوصف: Background and objectives Wound healing is an important biomedical problem with various associated complications. Although cutaneous wound healing has been studied in vivo extensively using various optical imaging methods, early-stage cellular healing processes were difficult to study due to scab formation. The objective of this study is to demonstrate that minimal laser wounds and optical microscopy can access the detailed cellular healing processes of cutaneous wounds from the early stage. Study design/materials and methods A non-ablative fractional laser (NAFL) and label-free two-photon microscopy (TPM) were used to induce minimal cutaneous wounds and to image the wounds in three-dimension. Sixteen hairless mice and a single human volunteer were used. NAFL wounds were induced in the hindlimb skin of the mice and in the forearm skin of the human subject. The NAFL wounds were longitudinally imaged during the healing period, starting from an hour post wound induction in the earliest and until 21 days. Cells in the wound and surrounding normal skin were visualized based on two-photon excited auto-fluorescence (TPAF), and cellular changes were tracked by analyzing longitudinal TPM images both qualitatively and quantitatively. Damage and recovery in the skin dermis were tracked by using the second harmonic generation (SHG) signal of collagen. Immunofluorescence and hematoxylin and eosin histology analysis were conducted to validate the TPM results of the murine skin. Results Cellular healing processes in NAFL wounds and surroundings could be observed by longitudinal TPM. In the case of murine skin, various healing phases including inflammation, re-epithelization, granulation tissue formation, and late remodeling phase including collagen regeneration were observed in the same wounds owing to minimal or no scab formation. The re-epithelization process was analyzed quantitatively by measuring cell density and thickness of the epithelium in the wound surroundings. In the case of the human skin, the access inside the wound was blocked for a few days post wound induction due to scabs but the cellular changes in the wound surroundings were observed from the early stage. Cellular healing processes in the NAFL wound of the human skin were similar to those in murine skin. Conclusions The minimal NAFL wound model and label-free TPM demonstrated the cell level assessment of wound healing processes with applicability to human subjects. © 2021 Wiley Periodicals LLC.

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    المصدر: Lasers in Surgery and Medicine. 53:1192-1200

    الوصف: BACKGROUND AND OBJECTIVES There remains a need to objectively monitor burn wound healing within a clinical setting, and optical coherence tomography (OCT) is proving itself one of the ideal modalities for just such a use. The aim of this study is to utilize the noninvasive and multipurpose capabilities of OCT, along with its cellular-level resolution, to demonstrate the application of optical attenuation coefficient (OAC), as derived from OCT data, to facilitate the automatic digital segmentation of the epidermis from scan images and to work as an objective indicator for burn wound healing assessment. STUDY DESIGN/MATERIALS AND METHODS A simple, yet efficient, method was used to estimate OAC from OCT images taken over multiple time points following acute burn injury. This method enhanced dermal-epidermal junction (DEJ) contrast, which facilitated the automatic segmentation of the epidermis for subsequent thickness measurements. In addition, we also measured and compared the average OAC of the dermis within said burns for correlative purposes. RESULTS Compared with unaltered OCT maps, enhanced DEJ contrast was shown in OAC maps, both from single A-lines and completed B-frames. En face epidermal thickness and dermal OAC maps both demonstrated significant changes between imaging sessions following burn injury, such as a loss of epidermal texture and decreased OAC. Quantitative analysis also showed that OAC of acute burned skin decreased below that of healthy skin following injury. CONCLUSIONS Our study has demonstrated that the OAC estimated from OCT data can be used to enhance imaging contrast to facilitate the automatic segmentation of the epidermal layer, as well as help elucidate our understanding of the pathological changes that occur in human skin when exposed to acute burn injury, which could serve as an objective indicator of skin injury and healing.

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    المصدر: Lasers in Surgery and Medicine. 53:1166-1172

    الوصف: Background and objectives Combining the efficacy of ablative fractional carbon dioxide lasers (AFXL) to laser-assisted hyaluronic acid delivery (LAHAD) has not yet been studied. The objective of our study was to evaluate the safety and the efficacy of laser-assisted hyaluronic acid (HA) delivery with AFXL in facial skin remodeling. Study design/materials and methods We conducted a prospective, double-blinded, randomized split-face study on 20 patients from 30 to 70 years old, with a skin phototype from I to IV. Each patient received full-face treatment with AFXL, immediately followed by the application in droplets into the fractional ablative tunnels of 1 ml of HA gel on one hemiface and 1 ml of physiological saline on the other hemiface. To evaluate postlaser aftermath, the intensity of erythema, edema, and crusts was graded. To assess facial skin remodeling, we scored the improvement of skin texture, firmness, fine lines, and skin radiance from baseline. Patients were evaluated on the 3rd and 7th day, 1st and 3rd month using clinical evaluations, photographs, and patient questionnaires. Results We showed equivalence in postlaser aftermath between HA-treated and nontreated hemiface. Trend data analyses at the 3rd month suggested that immediate application of HA after AFXL resulted in a greater improvement in facial skin remodeling, especially for skin texture (mean score of 2.60 vs. 2.45) and skin firmness (mean score of 2.55 vs. 2.40). Skin radiance showed the best improvement, reaching almost a score of 5/10. Conclusions LAHAD with AFXL is a safe treatment showing promising results in facial skin remodeling. These findings need to be confirmed by a larger study to evaluate the value of LAHAD in daily clinical practice. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

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    المصدر: Lasers in Surgery and Medicine. 53:776-797

    الوصف: Background and objectives Technological advances in medicine have brought about many novel skin imaging devices. This review aims to evaluate the scientific evidence supporting the use of noninvasive optical imaging techniques to aid in the diagnosis and prognosis of inflammatory skin diseases. Study design/materials and methods PubMed and Scopus were searched in September 2020 according to PRISMA guidelines for articles using reflectance confocal microscopy (RCM), optical coherence tomography (OCT), and multiphoton microscopy (MPM) in inflammatory skin diseases, excluding studies monitoring treatment efficacy. Results At the time of the study, there were 66 articles that addressed the utilization of noninvasive imaging in interface, spongiotic, psoriasiform, vesiculobullous, and fibrosing/sclerosing inflammatory skin dermatoses: RCM was utilized in 46, OCT in 16, and MPM in 5 articles. RCM was most investigated in psoriasiform dermatoses, whereas OCT and MPM were both most investigated in spongiotic dermatoses, including atopic dermatitis and allergic contact dermatitis. Conclusions There is preliminary evidence to support the diagnostic potential of noninvasive optical imaging techniques in inflammatory skin diseases. Improvements in the devices and further correlation with histology will help broaden their utility. Additional studies are needed to determine the parameters for diagnostic features, disease differentiation, and staging of inflammatory skin conditions. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

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    المصدر: Lasers in Surgery and Medicine. 53:1050-1058

    الوصف: Background and objective To compare changes in skin sensitivity before and after treatment with a 1064-nm Q-switched Nd:YAG laser in healthy individuals, and to provide a reference for clinicians to use this laser reasonably. Study design/materials and methods Nineteen healthy female volunteers underwent 10 random unilateral 1064-nm Q-switched Nd:YAG laser treatments. The skin transepidermal water loss rate (TEWL), skin glossiness, epidermal and dermal thickness and density, current perception threshold (CPT) value, facial blood perfusion were determined before and after treatment at different time points. Moreover, the changes in skin barrier function, blood vessels, and sensory nerve reaction in the treated and untreated sides of the face were recorded before and after treatment. Results Seventeen volunteers completed the 12-month follow-up study after 1064-nm Q-switched Nd:YAG laser treatment. At D3, M3, and M6, skin TEWL was decreased on the treated side of the face. Skin glossiness was significantly improved in the early post-treatment period (D1-D7) and M3, M6, and M12 compared with the untreated side of the face. There was no significant change in dermal and epidermal thickness or density at all time points before and after treatment. There were no significant differences in sensory nerve CPT values and local blood flow volume or velocity between the treated side of the face and the untreated side before and after treatment. Conclusion Multiple low-energy 1064-nm Q-switched Nd:YAG laser treatments will not affect the barrier function of facial skin, skin nerve sensitivity, or local microcirculation of healthy skin over the long term. Therefore, 1064-nm Q-switched Nd:YAG laser treatment is safe, and does not alter skin sensitivity. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

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    المؤلفون: Yacov Domankevitz, Edward V. Ross

    المصدر: Lasers in Surgery and Medicine. 53:1020-1025

    الوصف: Background and objectives The 1064 nm wavelength is optimized for dark skin, but within the range of available fluences for commercially available 1064 nm devices, may not provide effective treatment for lighter hair. The 755 nm alexandrite wavelength can treat a full range of hair colors but is not ideal for darker skin. The hypothesis is that a new laser system capable of emitting 755/1064 nm wavelengths simultaneously allows for safer, effective, and less painful hair reduction over a range of skin and hair types. Study design/materials and methods We completed treatment in 36 patients in this institutional review board approved prospective randomized study. Ages ranged from 20 to 55 and the distribution of skin types was: I (14% of patients), II (50% of patients), III (18% of patients), IV (18% of patients). Areas included the axilla and lower extremity. A prototype laser system emitted 755/1064 nm simultaneously. The spot size was 12 mm and the pulse duration was 3 milliseconds. The percentage of each wavelength in the mixture varied from 0% to 100%. Total radiant exposure ranged from 20 to 50 J/cm2 . Test spots were performed with escalating doses of light for each category (alexandrite alone, Nd YAG alone, and blended). Patients returned within 1 week for evaluation of side effects. The highest fluence without side effects for each category was then applied in two sessions 1 month apart. Final hair counts were performed 2 months after the final treatment. Results Optimal light doses (in J/cm2 ) for the range of skin types were as follows: for alexandrite alone, YAG alone, and blended. (Skin type I) 40, 70, 40-10; (II) 40, 70, 40-10; (III) 34, 60, 30-20; (IV) 26, 60, 20-30; (V) 18, 50, 14-36. After 2 months, there was greater than 50% hair reduction in 40%, 24%, and 60% of subjects on the lower extremity for the alexandrite, Nd YAG, and blended groups, respectively, and 20%, 25%, and 24% for the axilla. Our data show that for "challenging" cases, that is, darker skin types or tanned skin with lighter hairs, a 70/30 mixture of Nd:YAG and alexandrite wavelengths tended to produce the greatest hair reduction and least epidermal compromise while maintaining a lower pain level than Nd YAG alone. Conclusions Modeling and data suggest that 755/1064 nm mixture is useful in lighter hair removal treatment for darker skin types. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

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    المصدر: Lasers in Surgery and Medicine. 53:978-985

    الوصف: Background and objectives Cryotherapy for melanocytic lesions is often accompanied by collateral damage to the surrounding skin, resulting in skin necrosis and scarring. Adipocytes, like melanocytes, are neural crest-derived cells. Adipocytes have been shown to be more sensitive to cold exposure than their neighboring cells of ectodermal origin, such as epidermal keratinocytes. Such differential sensitivity to cold exposure has led to the development of novel treatment modalities, like cryolipolysis, to selectively target a cell type while sparing neighboring cells. Study design/materials and methods In this study, we investigated the roles of controlled skin freezing, tissue temperature, and exposure time in inducing selective loss of melanocytes and skin depigmentation in swines. Results The results of our study demonstrated that contact cooling of the skin surface causes selective loss of epidermal melanocytes when the tissue temperature reaches -7.5°C or cooler with an exposure time of 10 minutes or longer, leading to partial skin depigmentation in swine skin. Longer exposures combined with colder temperature exposure led to more complete depigmentation in the treated skin surface. Conclusion Cold-sensitivity of melanocytes can be harnessed to selectively remove melanocytes while sparing surrounding keratinocytes. The results from this study demonstrated that improved clinical treatments specifically targeting melanocytic lesions is possible using skin cooling to achieve tissue temperatures capable of inducing selective loss of melanocytes without skin necrosis or scarring. Additional studies are needed to optimize the treatment conditions to prolong the selective removal of melanocytes. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

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    المصدر: Lasers in Surgery and Medicine. 53:861-864

    الوصف: Background and objectives Melasma may be related to aberrant blood vessels, but there has been no report on the utility of dynamic optical coherence tomography (D-OCT) in studying vessel characteristics in melasma. We studied the characteristics of cutaneous blood vessels in melasma and the effects of oral tranexamic acid (TXA) with D-OCT. Study design/materials and methods Six patients with moderate to severe melasma had a D-OCT scanning of the areas on the face affected by melasma and not affected by it. Three of them had scans within 3 months after starting oral TXA and at a follow-up visit. Blood flow at different depths of the skin and vessel diameter were compared between the melasma and normal skin. For those taking oral TXA, we compared the percent change of blood flow and diameter between the melasma and normal skin. Results Dermal blood flow and vessel diameter were greater in the melasma skin than in the normal skin. Oral TXA reduced dermal blood flow in both the melasma and normal skin, but the reduction was more dramatic in the lesional melasma skin. Conclusions D-OCT findings that (i) dermal blood vessels in melasma are increased in size and flow and (ii) oral TXA reduced the vessel size and flow, providing evidence supporting the relationship between melasma and cutaneous blood vessels. D-OCT may be utilized in measuring response to treatments targeting melasma. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

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    المصدر: Lasers in Surgery and Medicine. 53:171-178

    الوصف: Background and objectives One of the challenges in developing effective hair loss therapies is the lack of reliable methods to monitor treatment response or alopecia progression. In this study, we propose the use of optical coherence tomography (OCT) and automated deep learning to non-invasively evaluate hair and follicle counts that may be used to monitor the success of hair growth therapy more accurately and efficiently. Study design/materials and methods We collected 70 OCT scans from 14 patients with alopecia and trained a convolutional neural network (CNN) to automatically count all follicles present in the scans. The model is based on a dual approach of both detecting hair follicles and estimating the local hair density in order to give accurate counts even for cases where two or more adjacent hairs are in close proximity to each other. Results We evaluate our system on 70 OCT manually labeled scans taken at different scalp locations from 14 patients, with 20 of those redundantly labeled by two human expert OCT operators. When comparing the individual human predictions and considering the exact locations of hair and follicle predictions, we find that the two human raters disagree with each other on approximately 22% of hairs and follicles. Overall, the deep learning (DL) system predicts the number of follicles with an error rate of 11.8% and the number of hairs with an error rate of 18.7% on average on the 70 scans. The OCT system can capture one scalp location in three seconds, and the DL model can make all predictions in less than a second after processing the scan, which takes half a minute using an unoptimized implementation. Conclusion This approach is well-positioned to become the standard for non-invasive evaluation of hair growth treatment progress in patients, saving significant amounts of time and effort compared with manual evaluation. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

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    المصدر: Lasers in Surgery and Medicine. 53:549-556

    الوصف: Background and objectives We previously demonstrated that intense pulsed light (IPL) irradiation prior to wounding improved the wound healing in rats with diabetes mellitus (DM). Also, we found that IPL upregulated the expression of aquaporin 3 (AQP3), a protein that is crucial for wound healing, in normal rats. This present study aimed to examine the involvement of AQPs in the IPL-enhanced wound healing in diabetic rats. Study design/materials and methods Streptozotocin was used to induce diabetes in Sprague-Dawley rats. Animals were divided into four groups: normal group, DM only group, DM rats with IPL treatment 2 weeks before wounding (DM + IPL-Pre group), and DM rats with concurrent IPL irradiation and wounding (DM + IPL-Con group). Wounds were created on the dorsal skin of rats. The expressions of AQP1, 3, 4, 7, and 9 in the pre-injured skin, periwound, and wound were determined. Results Among all the AQPs analyzed, only the expressions of AQP3 and AQP7 were significantly altered. Unirradiated diabetic rats showed much higher expression level of AQP3 in the regenerating skin compared with normal rats. IPL pretreatment, but not concurrent treatment, attenuated the expression toward the level detected in the normal wounds. In contrast, a lower expression level of AQP7 was noted in the regenerating skin of DM only rats and IPL pretreatment upregulated the expression to a level similar to that in the normal rats. Conclusion The beneficial effect of IPL pretreatment on the wound healing in diabetic rats might involve a mechanism by which the expression of AQPs is regulated. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.