Retrospective study of the treatment of port-wine stains with 595-nm pulsed dye laser in 261 Chinese patients.

Pulsed dye laser (PDL) at the wavelength of 595 nm is the common choice for the treatment of port-wine stains (PWSs). In this study, the efficacy of 595-nm PDL in treatment of PWSs in Chinese patients was investigated. A follow-up visit was performed on 261 Fitzpatrick skin type II-III Chinese patients with PWS who received more than two treatments with 595-nm PDL. Based on cosmetic improvement, treatment response was graded as follows: complete, if color blanching was > 90%; significant, if color blanching was 60-90%; moderate, if color blanching was 30-60%; and poor, if color blanching was < 30%. The efficacy of laser treatment on patients of different treatment numbers, ages, lesion locations, lesion colors, extents of hypertrophy, and laser pulse durations was evaluated. All patients improved following an average of almost 4 to 5 laser treatments. The earlier the intervention, the better the efficacy was. Lesions on cheek, neck, and forehead were better than that those on oral, eye periorbital, and nose areas. The purple group had a more excellent clearance, i.e., complete and significant clearance rate (53.6%), than the red group (36.1%). Treatment effect became worse as the extent of lesion hypertrophy increased. PWS lesions treated with short pulse durations of 0.45, 1.5, and 3 ms had better clearance (complete and significant clearance) rate of 56.5% than those treated with pulse durations of 6 ms or longer (34.8%). Pulsed dye laser with 595-nm laser equipped with dynamic cooling device is an effective option for the treatment of PWS in Chinese patients. Younger patients with lateral face position, larger vessel size (deeper color), and lesser hypertrophy received better clinical effect than the others. Treatment with short pulse duration of less than 3 ms for 4 to 5 times was recommended to treat PWS.

Gold nanospheres enhanced photothermal therapy in a rat model.

BACKGROUND AND OBJECTIVE: Efficient photothermal conversion of gold nanoparticles with strong light absorption suggests their wide use as selective photothermal agents in biomedical fields. The aim of this study is to investigate the use of gold nanospheres (GNPs) as exogenous visible light absorbers to improve laser treatment of port-wine stains. MATERIALS AND METHODS: Thiol-terminated methoxypolyethylene glycol modified GNPs (PEG-GNPs) with peak extinction matching the visible light wavelength of the laser being used were synthesized. An in vitro capillary experiment was prepared to investigate the thermal response of blood vessels with and without injection of 4.54 mg PEG-GNPs in mice prior to irradiation by a frequency-doubled Nd:YAG laser at a wavelength of 532 nm. RESULTS: The in vitro results demonstrated that the photocoagulation size in blood vessels after exposed to laser light increased with the increment of concentration of PEG-GNPs in blood within a certain range. However, the unwanted thermal response (i.e., cavitation) occurred when the concentration of PEG-GNPs in blood was larger than 2.5 mg/ml. The in vivo results suggested that more obvious blood thermal response can be induced by laser light after injection of PEG-GNPs. After injection of 4.54 mg PEG-GNPs, laser radiant exposure required for thread-like constriction of blood vessels decreased from 12.5 to 9.8 J/cm2 with the pulse duration of 10 ms, from 15 to 11.85 J/cm2 with the pulse duration of 30 ms, respectively. CONCLUSION: This in vitro and in vivo experimental results show that PEG-GNPs combined with laser light could be a promising modality to reduce the radiant exposure required for obvious blood thermal response, thereby providing a potential strategy for improving the laser treatment of cutaneous vascular lesions. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

Correction to: Glucose in Conjunction with Multiple Laser Pulses on Laser Treatment of Port-wine Stain: An in vivo Study.

In the originally published article, the title was incorrectly copied from another article. The correct title is "Glucose in Conjunction with Multiple Laser Pulses on Laser Treatment of Port-wine Stain: An in vivo Study", which is also shown above.

Glucose in Conjunction with Multiple Laser Pulses on Laser Treatment of Port-wine Stain: An in vivo Study.

Port-wine stain (PWS) birthmark is a congenital microvascular malformation of the skin. A 1064-nm Nd:YAG laser can achieve a deeper treatment, but the weak absorption by blood limits its clinical application. Multiple laser pulses (MLPs) are a potential solution to enhance the curative effect of a Nd:YAG laser. To reduce the pulse number (pn) required for the thermal destruction of the blood vessel, the effect of glucose in conjunction with MLP was investigated. In vivo experiments were performed on a dorsal skin chamber model. Different concentrations (20, 25, 30, and 40%) of glucose were applied to the sub-dermal side of the hamster skin before laser irradiation. Identical vessels with diameters of 200 ± 30 and 110 ± 20 µm were chosen as representatives of typical PWS vessels. Instant thermal responses of the blood vessel were recorded by a high-speed camera. The required pn for blood vessel damage was compared with that without glucose pretreatment. Results showed that the use of glucose with a concentration of 20% combined with MLP Nd:YAG laser to damage blood vessels is more appropriate because severe hemorrhage or carbonization easily appeared in blood vessels at higher glucose concentration of 25, 30, and 40%. When 20% glycerol is pretreated on the sub-dermal hamster skin, the required pn for blood vessel damage can be significantly decreased for different power densities. For example, pn can be reduced by 40% when the power density is 57 J/cm2. In addition, generation of cavitation and bubbles in blood vessels is difficult upon pretreatment with glucose. The combination of glucose with MLP Nd:YAG laser could be an effective protocol for reducing the pn required for blood vessel damage. Randomized controlled trial (RCT) and human trials will be conducted in the future.

Experimental and numerical investigation on the transient vascular thermal response to multi-pulse Nd:YAG laser.

BACKGROUND AND OBJECTIVE: Port wine stains (PWS) are congenital vascular malformations that progressively darken and thicken with age. Laser therapy is currently the most effective way in clinical practice for PWS. A 1,064 nm Nd:YAG laser in the near-infrared band can achieve a deeper treatment depth compared to the current widely adopted pulsed dye laser. However, because of its relatively weak absorption by blood, single-pulse Nd:YAG laser requires high energy density to cause effective vessel damage, but may inflict undesirable burning to surrounding collagen. Multi-pulse laser has great potential in clinical treatment because it needs less energy density for each pulse. This paper presented an experimental and theoretical study of the transient thermal effects of low-energy multi-pulse Nd:YAG laser on blood vessels. STUDY DESIGN/MATERIALS AND METHODS: In vivo experiments were performed on dorsal skin chamber. By using a high speed camera (up to 2,000 fps), the complete and dynamic thermal response of blood vessels during laser irradiation and between pulse intervals was obtained. In vitro experiment in capillary tubes and Numerical simulations by two-scale heat transfer model were also conducted to further explore the in vivo experimental findings. RESULTS: The complete and dynamic response of blood vessels were obtained, including vessel dilation, thrombus formation, partial vessel constriction, thread-like constriction, cavitation and bubbles, and hemorrhage. Thread-like constriction is the desirable treatment end point, which will only occur after thrombus completely occludes the vessel lumen. Cavitation can cause hemorrhage when thrombus fails to occlude the vessel lumen. In vitro experiment found that vessel constriction was due to the constriction of thrombus induced by laser irradiation. Theoretical investigation revealed that the mechanism for the effective reduction of energy density by multi-pulse Nd:YAG laser was due to enhanced light absorption of the blood with thrombus formation. CONCLUSIONS: For multi-pulse treatment, laser parameters are recommended as repetition rate of 10 Hz and pulse number of 10. The incident energy in each pulse should be strong enough to induce blood coagulation through seven or eight pulses and should be lower than the threshold of blood cavitation. Lasers Surg. Med. 49:852-865, 2017. © 2017 Wiley Periodicals, Inc.

Experimental investigation on the vascular thermal response to near-infrared laser pulses.

Port wine stains (PWS) are congenital vascular malformations that progressively darken and thicken with age. To improve the effect of laser therapy in clinical practice, thermal response of blood vessel to a 1064 nm Nd:YAG laser with controlled energy doses and pulse durations was evaluated using the dorsal skin chamber model. A total of 137 vessels with 30-300 µm diameters were selected from the dorsal skin of the mouse to match those capillaries in port wine stains. Experimental results showed that the thermal response of blood vessels to 1064 nm laser irradiation can be classified as follows: vessel dilation, coagulation, constriction with decreased diameter, complete constriction, hemorrhage, and collagen damage with increasing laser radiant exposure. In most cases, that is, 83 of 137 blood vessels (60.6%), Nd:YAG laser irradiation was characterized by complete constriction (immediate blood vessel disappearance). To reveal the possible damage mechanisms and evaluate blood vessel photocoagulation patterns, theoretical investigation using bioheat transfer equation was conducted in mouse skin with a depth of 1000 µm. Complete constriction as the dominant thermal response as evidenced by uniform blood heating within the vessel lumen was noted in both experimental observation and theoretical investigation. To achieve the ideal clinical effect using the Nd:YAG laser treatment, the radiant exposure should not only be high enough to induce complete constriction of the blood vessels but also controlled carefully to avoid surrounding collagen damage. The short pulse duration of 1-3 ms is better than long pulse durations because hemorrhaging of small capillaries is occasionally observed postirradiation with pulse durations longer than 10 ms.

The Msi1-mTOR pathway drives the pathogenesis of mammary and extramammary Paget's disease.

Mammary and extramammary Paget's Diseases (PD) are a malignant skin cancer characterized by the appearance of Paget cells. Although easily diagnosed, its pathogenesis remains unknown. Here, single-cell RNA-sequencing identified distinct cellular states, novel biomarkers, and signaling pathways - including mTOR, associated with extramammary PD. Interestingly, we identified MSI1 ectopic overexpression in basal epithelial cells of human PD skin, and show that Msi1 overexpression in the epidermal basal layer of mice phenocopies human PD at histopathological, single-cell and molecular levels. Using this mouse model, we identified novel biomarkers of Paget-like cells that translated to human Paget cells. Furthermore, single-cell trajectory, RNA velocity and lineage-tracing analyses revealed a putative keratinocyte-to-Paget-like cell conversion, supporting the in situ transformation theory of disease pathogenesis. Mechanistically, the Msi1-mTOR pathway drives keratinocyte-Paget-like cell conversion, and suppression of mTOR signaling with Rapamycin significantly rescued the Paget-like phenotype in Msi1-overexpressing transgenic mice. Topical Rapamycin treatment improved extramammary PD-associated symptoms in humans, suggesting mTOR inhibition as a novel therapeutic treatment in PD.

The progression of CD56+ myeloid sarcoma: A case report and literature review.

The current study presents a case of cluster of differentiation (CD)56+ myeloid sarcoma in a patient that initially presented with skin lesions, and provides evidence for the clinical and differential diagnosis of myeloid sarcoma. The patient of the present case report was a 65-year-old man who was admitted to hospital with a six-month history of bilateral purple-red papules and nodules, which were present on the upper limbs of the patient and had spread over his whole body one month prior to admission to the hospital. Pathological examination demonstrated a diffuse infusion of primitive round cells at the papillary dermis and subcutaneous tissues. The infiltrated cells were 40-60 µm in diameter and morphologically identical. Immunohistochemical examination revealed that the cells expressed myeloperoxidase, CD56, CD43 and T-cell intracytoplasmic antigen. In addition, several cells expressed CD34, and 90% of the cells expressed Ki67. While the majority of cells in myeloid sarcoma do not express CD56, the present case was a myeloid sarcoma that expressed CD56, which is extremely rare. The sarcoma in the present patient progressed rapidly, and the patient died eight months following the onset of disease. Clinicians should be aware of CD56+ myeloid sarcoma, which is easily misdiagnosed and inappropriately treated. Consequently, myeloid sarcoma may have a high malignancy and poor outcome for patients.

Dermatofibrosarcoma protuberans with pit-like lesions: A case report and literature review.

The present study describes a case of pit-like dermatofibrosarcoma protuberans (DFSP) with the clinical manifestations, histopathological features and criteria for diagnosis. The study also reviews the relevant literature in order to raise awareness among dermatologists with regard to the specific behavior of DFSP. A 27-year-old female presented with subcutaneous nodules on the left side of the neck that had been apparent for 5 years and which had gradually begun caving in during the last year. Histopathological examination revealed that the tumor was composed of a large number of spindle cells arranged in a whirlpool-like pattern. Immunohistochemical studies revealed positive staining for cluster of differentiation 34, vimentin and lysozyme, which could be used as diagnostic markers of DFSP. The patient was finally diagnosed with DFSP by pathological and immunohistochemical analyses. The DFSP was treated with an extended resection followed by adjacent skin repair. The patient responded well and no relapse occurred during the 8-month clinical follow-up. Thus, the current study describes a unique pit-like clinical manifestation of DFSP with typical immunohistochemical and pathological features. In addition, histopathological examination revealed a downward depression in the epidermis. Therefore, histopathological examination should be considered as an essential diagnostic tool for DFSP.

Lymphomatoid papulosis misdiagnosed as pityriasis lichenoides et varioliformis acuta: Two case reports and a literature review.

The aim of this study was to improve the level of diagnosis and differential diagnosis of lymphomatoid papulosis (LyP). Two cases of type B LyP were identified and the literature was reviewed to summarize the clinical outcomes and pathology of LyP and its treatment. The two patients exhibited symptoms with papulonodular lesions, the centers of which gradually underwent ulceration and necrosis. CD30, a helper T-cell marker specifically expressed in tumor cells was analyzed by immunohistochemical staining and the result showed that CD30-negative or only scattered CD30-positive cells were present. Therefore, a diagnosis of type B LyP was made. A fairly good curative effect was achieved following treatment with retinoic acid, glucocorticoids and immunomodulatory drugs. LyP is a type of low-level malignant lymphoma and is easily misdiagnosed as pityriasis lichenoides et varioliformis acuta and other diseases. In order to avoid under diagnosis and misdiagnosis, doctors should evaluate suspected patients by histopathological and immunohistochemical examination.