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Stuart J. Nelson - One of the best experts on this subject based on the ideXlab platform.

  • The Pathogenesis of Port Wine Stain and Sturge Weber Syndrome: Complex Interactions between Genetic Alterations and Aberrant MAPK and PI3K Activation
    MDPI AG, 2019
    Co-Authors: Vi Nguyen, Martin C Mihm, Stuart J. Nelson, Marcelo Hochman, Wenbin Tan
    Abstract:

    Port wine Stain (PWS) is a congenital vascular malformation involving human skin. Approximately 15−20% of children a facial PWS involving the ophthalmic (V1) trigeminal dermatome are at risk for Sturge Weber syndrome (SWS), a neurocutaneous disorder with vascular malformations in the cerebral cortex on the same side of the facial PWS lesions. Recently, evidence has surfaced that advanced our understanding of the pathogenesis of PWS/SWS, including discoveries of somatic genetic mutations (GNAQ, PI3K), MAPK and PI3K aberrant activations, and molecular phenotypes of PWS endothelial cells. In this review, we summarize current knowledge on the etiology and pathology of PWS/SWS based on evidence that the activation of MAPK and/or PI3K contributes to the malformations, as well as potential futuristic treatment approaches targeting these aberrantly dysregulated signaling pathways. Current data support that: (1) PWS is a multifactorial malformation involving the entire physiological structure of human skin; (2) PWS should be pathoanatomically re-defined as “a malformation resulting from differentiation-impaired endothelial cells with a progressive dilatation of immature venule-like vasculatures”; (3) dysregulation of vascular MAPK and/or PI3K signaling during human embryonic development plays a part in the pathogenesis and progression of PWS/SWS; and (4) sporadic low frequency somatic mutations, such as GNAQ, PI3K, work as team players but not as a lone wolf, contributing to the development of vascular phenotypes. We also address many crucial questions yet to be answered in the future research investigations

  • The Role of Laser Speckle Imaging in Port-Wine Stain Research: Recent Advances and Opportunities
    IEEE Journal of Selected Topics in Quantum Electronics, 2016
    Co-Authors: Bernard Choi, Sean M. White, Bruce Y. Yang, Zhongping Chen, Kristen M. Kelly, Stuart J. Nelson
    Abstract:

    Here, we review our current knowledge on the etiology and treatment of Port-Wine Stain (PWS) birthmarks. Current treatment options have significant limitations in terms of efficacy. With the combination of 1) a suitable preclinical microvascular model, 2) laser speckle imaging (LSI) to evaluate blood-flow dynamics, and 3) a longitudinal experimental design, rapid preclinical assessment of new phototherapies can be translated from the lab to the clinic. The combination of photodynamic therapy (PDT) and pulsed-dye laser (PDL) irradiation achieves a synergistic effect that reduces the required radiant exposures of the individual phototherapies to achieve persistent vascular shutdown. PDL combined with antiangiogenic agents is a promising strategy to achieve persistent vascular shutdown by preventing reformation and reperfusion of photocoagulated blood vessels. Integration of LSI into the clinical workflow may lead to surgical image guidance that maximizes acute photocoagulation, which is expected to improve PWS therapeutic outcome. Continued integration of noninvasive optical imaging technologies and biochemical analysis collectively are expected to lead to more robust treatment strategies.

  • spatial frequency domain imaging of port wine Stain biochemical composition in response to laser therapy a pilot study
    Lasers in Surgery and Medicine, 2012
    Co-Authors: Amaan Mazhar, Stuart J. Nelson, Kristen M. Kelly, Seyed A Sharif, David J Cuccia, Anthony J Durkin
    Abstract:

    Background and Objective: Objective methods to assess port wine Stain (PWS) response to laser treatment have been the subject of various research efforts for several years. Herein, we present a pilot study using a newly developed, light emitting diode (LED) based spatial frequency domain imaging (SFDI) device to record quantitatively biochemical compositional changes in PWS after laser therapy. Study Design/Patients and Methods: A SFDI system was used to image before, and after, five PWS treatment sessions [n ¼ 4 subjects (one subject was imaged before and after two consecutive laser treatments)]. SFDI derived wide-field optical properties (absorption and scattering) and tissue chromophore concentrations including oxy-hemoglobin (ctO2Hb), deoxy-hemoglobin (ctHHb), total hemoglobin (ctTHb), and tissue oxygen saturation (stO2) are presented for skin imaged prior to and immediately after laser treatment. The SFDI derived images were analyzed by comparing the above measurements in PWS to those of normal skin and tracking changes immediately after laser exposure. Results: Elevated oxy-hemoglobin (>20%) and tissue oxygen saturation (>5%) were measured in all PWS lesions and compared to values for normal skin prior to treatment. Laser treatment resulted in an increase in deoxyhemoglobin (>100%), decrease in tissue oxygen saturation (>10%), and reduced scattering (>15%) in all PWS lesions. One subject was followed before and after two consecutive laser treatments and the overall improvement in PWS lesion blanching was quantitatively assessed by measuring a 45% decrease in dermal blood volume. Conclusion: SFDI is a rapid non-contact wide-field optical technique that shows potential as an imaging device that can be used to quantify biochemical compositional changes in PWS after laser therapy. Future work will investigate the potential of SFDI to provide intraoperative guidance for laser therapy of PWS lesions on an individual patient basis. Lasers Surg. Med. 2012 Wiley Periodicals, Inc.

  • observations on enhanced port wine Stain blanching induced by combined pulsed dye laser and rapamycin administration
    Lasers in Surgery and Medicine, 2011
    Co-Authors: Stuart J. Nelson, Thuy L. Phung, Martin C Mihm
    Abstract:

    Port wine Stain (PWS) is a congenital, progressive vascular malformation of skin involving post-capillary venules that occurs in an estimated 3–4 children per 1,000 live births (1–3). Since most malformations occur on the face and neck, PWS is a clinically significant problem in the majority of patients. PWS are initially flat red macules that can be localized or segmental, but lesions tend to darken progressively, and by middle age, often transform into dark-red or purple plaques with nodularity (4, 5).

  • pilot study examining the combined use of pulsed dye laser and topical imiquimod versus laser alone for treatment of port wine Stain birthmarks
    Lasers in Surgery and Medicine, 2008
    Co-Authors: Cheng Jen Chang, Martin C Mihm, Yen Chang Hsiao, Stuart J. Nelson
    Abstract:

    Background and Objective: The objective of this study was to improve port wine Stain (PWS) therapeutic outcome in response to laser therapy. Our specific aim was to determine whether the combined use of pulsed dye laser (PDL) therapy and topical Imiquimod versus PDL alone can improve PWS therapeutic outcome. Study Design/Materials and Methods: This pilot study involved a retrospective review of 20 subjects, all Asian, with PWS. Subject ages ranged between 3 and 56 years. Upon enrollment, three test sites were prospectively identified on each subject for treatment assignments to the following regimens: (A) PDLþImiquimod; (B) PDL alone; and (C) Imiquimod alone. PDL test sites received a single treatment with a 585 nm wavelength; 1.5 milliseconds pulse duration; spot size 7 mm using a light dosage of 10 J/cm 2 with cryogen spray cooling. For the PDLþImiquimod and Imiquimod alone test sites, subjects were instructed to apply Imiquimod topically to the sites once daily for 1 month after PDL exposure. Subjects were followed-up at 1, 3, 6, and 12 months after PDL exposure to evaluate each of the three test sites. The primary efficacy measurement was the quantitative assessment of blanching responses as measured by a DermoSpectrometer to calculate the hemoglobin-index of each site at 1, 3, 6, and 12 months after PDL exposure. Subjects were also closely monitored for any adverse effects. Results: Based on paired sample test analysis, there were clinically, and statistically significant, differences in blanching responses over time favoring PWS receiving PDLþImiquimod as compared to either PDL or Imiquimod alone (P<0.05). At 12 months, it should be noted that there was some evidence of redarkening of PWS test sites treated by PDLþImiquimod and PDL alone, presumably due to revascularization of blood vessels. However, based on comparison of the hemoglobin-indices determined at 1 and 12 months after PDL exposure, there was less

Martin C Mihm - One of the best experts on this subject based on the ideXlab platform.

  • The Pathogenesis of Port Wine Stain and Sturge Weber Syndrome: Complex Interactions between Genetic Alterations and Aberrant MAPK and PI3K Activation
    MDPI AG, 2019
    Co-Authors: Vi Nguyen, Martin C Mihm, Stuart J. Nelson, Marcelo Hochman, Wenbin Tan
    Abstract:

    Port wine Stain (PWS) is a congenital vascular malformation involving human skin. Approximately 15−20% of children a facial PWS involving the ophthalmic (V1) trigeminal dermatome are at risk for Sturge Weber syndrome (SWS), a neurocutaneous disorder with vascular malformations in the cerebral cortex on the same side of the facial PWS lesions. Recently, evidence has surfaced that advanced our understanding of the pathogenesis of PWS/SWS, including discoveries of somatic genetic mutations (GNAQ, PI3K), MAPK and PI3K aberrant activations, and molecular phenotypes of PWS endothelial cells. In this review, we summarize current knowledge on the etiology and pathology of PWS/SWS based on evidence that the activation of MAPK and/or PI3K contributes to the malformations, as well as potential futuristic treatment approaches targeting these aberrantly dysregulated signaling pathways. Current data support that: (1) PWS is a multifactorial malformation involving the entire physiological structure of human skin; (2) PWS should be pathoanatomically re-defined as “a malformation resulting from differentiation-impaired endothelial cells with a progressive dilatation of immature venule-like vasculatures”; (3) dysregulation of vascular MAPK and/or PI3K signaling during human embryonic development plays a part in the pathogenesis and progression of PWS/SWS; and (4) sporadic low frequency somatic mutations, such as GNAQ, PI3K, work as team players but not as a lone wolf, contributing to the development of vascular phenotypes. We also address many crucial questions yet to be answered in the future research investigations

  • observations on enhanced port wine Stain blanching induced by combined pulsed dye laser and rapamycin administration
    Lasers in Surgery and Medicine, 2011
    Co-Authors: Stuart J. Nelson, Thuy L. Phung, Martin C Mihm
    Abstract:

    Port wine Stain (PWS) is a congenital, progressive vascular malformation of skin involving post-capillary venules that occurs in an estimated 3–4 children per 1,000 live births (1–3). Since most malformations occur on the face and neck, PWS is a clinically significant problem in the majority of patients. PWS are initially flat red macules that can be localized or segmental, but lesions tend to darken progressively, and by middle age, often transform into dark-red or purple plaques with nodularity (4, 5).

  • pilot study examining the combined use of pulsed dye laser and topical imiquimod versus laser alone for treatment of port wine Stain birthmarks
    Lasers in Surgery and Medicine, 2008
    Co-Authors: Cheng Jen Chang, Martin C Mihm, Yen Chang Hsiao, Stuart J. Nelson
    Abstract:

    Background and Objective: The objective of this study was to improve port wine Stain (PWS) therapeutic outcome in response to laser therapy. Our specific aim was to determine whether the combined use of pulsed dye laser (PDL) therapy and topical Imiquimod versus PDL alone can improve PWS therapeutic outcome. Study Design/Materials and Methods: This pilot study involved a retrospective review of 20 subjects, all Asian, with PWS. Subject ages ranged between 3 and 56 years. Upon enrollment, three test sites were prospectively identified on each subject for treatment assignments to the following regimens: (A) PDLþImiquimod; (B) PDL alone; and (C) Imiquimod alone. PDL test sites received a single treatment with a 585 nm wavelength; 1.5 milliseconds pulse duration; spot size 7 mm using a light dosage of 10 J/cm 2 with cryogen spray cooling. For the PDLþImiquimod and Imiquimod alone test sites, subjects were instructed to apply Imiquimod topically to the sites once daily for 1 month after PDL exposure. Subjects were followed-up at 1, 3, 6, and 12 months after PDL exposure to evaluate each of the three test sites. The primary efficacy measurement was the quantitative assessment of blanching responses as measured by a DermoSpectrometer to calculate the hemoglobin-index of each site at 1, 3, 6, and 12 months after PDL exposure. Subjects were also closely monitored for any adverse effects. Results: Based on paired sample test analysis, there were clinically, and statistically significant, differences in blanching responses over time favoring PWS receiving PDLþImiquimod as compared to either PDL or Imiquimod alone (P<0.05). At 12 months, it should be noted that there was some evidence of redarkening of PWS test sites treated by PDLþImiquimod and PDL alone, presumably due to revascularization of blood vessels. However, based on comparison of the hemoglobin-indices determined at 1 and 12 months after PDL exposure, there was less

  • can the wound healing response of human skin be modulated after laser treatment and the effects of exposure extended implications on the combined use of the pulsed dye laser and a topical angiogenesis inhibitor for treatment of port wine Stain birthm
    Lasers in Surgery and Medicine, 2008
    Co-Authors: Thuy L. Phung, Darryl A Oble, Martin C Mihm, Laura E Benjamin, Stuart J. Nelson
    Abstract:

    Port wine Stain (PWS), also called nevus flammeus, is a congenital, cutaneous vascular malformation involving post-capillary venules which produce a light pink to dark-red-violet discoloration of the skin. The most likely hypothesis for the development of PWS is the deficiency or absence of surrounding neurons regulating blood flow through the ectatic post-capillary venules. As a result, the blood vessels are unable to constrict normally and remain permanently dilated.

  • epithelial and mesenchymal hamartomatous changes in a mature port wine Stain morphologic evidence for a multiple germ layer field defect
    Journal of The American Academy of Dermatology, 2004
    Co-Authors: Ignacio Sanchezcarpintero, Martin C Mihm, Adam Mizeracki, Milton Waner, Paula E North
    Abstract:

    The Port-Wine Stain (PWS) is a congenital cutaneous venulocapillary malformation of unknown pathogenesis. Many patients with facial PWS develop thickening with cobblestoning and nodularity during adult life. The histologic correlates of this maturational change are poorly documented and its mechanisms remain unclear. In this case study we present new histologic observations that may elucidate this phenomenon. An extensive PWS on the face of a 75-year-old man exhibited gross thickening with cobblestoning and nodularity. Histologic examination revealed not only the expected vascular abnormalities, but also a number of widely distributed epithelial, neural, and mesenchymal hamartomatous changes. Epithelial changes included epidermal nevus, sebaceous trichofolliculoma, and basaloid follicular hamartoma. Changes of connective tissue nevus, smooth-muscle hamartoma, neural hamartoma, and subcuticular hamartoma were also noted. The complex hamartomatous changes observed in the PWS of this patient involved multiple germ lines and were distributed in a widespread pattern. These changes not only offer an explanation for the skin thickening and nodularity of this patient, but also suggest a genetically determined, multilineage developmental field defect in the pathogenesis of this lesion. Further studies of other patients are necessary to understand the full implications of these findings in the late stage of PWS.

Cheng Jen Chang - One of the best experts on this subject based on the ideXlab platform.

  • pilot study examining the combined use of pulsed dye laser and topical imiquimod versus laser alone for treatment of port wine Stain birthmarks
    Lasers in Surgery and Medicine, 2008
    Co-Authors: Cheng Jen Chang, Martin C Mihm, Yen Chang Hsiao, Stuart J. Nelson
    Abstract:

    Background and Objective: The objective of this study was to improve port wine Stain (PWS) therapeutic outcome in response to laser therapy. Our specific aim was to determine whether the combined use of pulsed dye laser (PDL) therapy and topical Imiquimod versus PDL alone can improve PWS therapeutic outcome. Study Design/Materials and Methods: This pilot study involved a retrospective review of 20 subjects, all Asian, with PWS. Subject ages ranged between 3 and 56 years. Upon enrollment, three test sites were prospectively identified on each subject for treatment assignments to the following regimens: (A) PDLþImiquimod; (B) PDL alone; and (C) Imiquimod alone. PDL test sites received a single treatment with a 585 nm wavelength; 1.5 milliseconds pulse duration; spot size 7 mm using a light dosage of 10 J/cm 2 with cryogen spray cooling. For the PDLþImiquimod and Imiquimod alone test sites, subjects were instructed to apply Imiquimod topically to the sites once daily for 1 month after PDL exposure. Subjects were followed-up at 1, 3, 6, and 12 months after PDL exposure to evaluate each of the three test sites. The primary efficacy measurement was the quantitative assessment of blanching responses as measured by a DermoSpectrometer to calculate the hemoglobin-index of each site at 1, 3, 6, and 12 months after PDL exposure. Subjects were also closely monitored for any adverse effects. Results: Based on paired sample test analysis, there were clinically, and statistically significant, differences in blanching responses over time favoring PWS receiving PDLþImiquimod as compared to either PDL or Imiquimod alone (P<0.05). At 12 months, it should be noted that there was some evidence of redarkening of PWS test sites treated by PDLþImiquimod and PDL alone, presumably due to revascularization of blood vessels. However, based on comparison of the hemoglobin-indices determined at 1 and 12 months after PDL exposure, there was less

  • cryogen spray cooling and higher fluence pulsed dye laser treatment improve port wine Stain clearance while minimizing epidermal damage
    Dermatologic Surgery, 1999
    Co-Authors: Cheng Jen Chang, Stuart J. Nelson
    Abstract:

    Background. When a cryogen spurt is applied to the skin surface for an appropriately short period of time (on the order of tens of milliseconds), the cooling remains localized in the epidermis, while leaving the temperature of the deeper Port-Wine Stain (PWS) blood vessels unchanged. Objective. The objective of this study was to compare the efficacy and safety of noncooled laser treatment (NC-LT), and cryogen spray cooled laser treatment (CSC-LT) of PWS birthmarks in a large series of patients. Methods. A retrospective review was conducted of 196 patients with head or neck PWS birthmarks treated with the pulsed dye laser (λ = 585 nm; τp= 450 μsec) over a 7-year period. Subjects' ages ranged between 2 months and 62 years; there were 109 females and 87 males, all of whom were Asian. Ninety-eight patients received NC-LT using light dosages of 5–7 J/cm2. Subsequently, 98 patients received CSC-LT using light dosages of 8–10 J/cm2. The primary efficacy measure was the quantitative assessment of the blanching response scores of NC-LT PWSs as compared, on a blinded basis, to CSC-LT PWSs. Results. Based on chi-squared analysis, there were clinical, and statistically significant, differences in the blanching response scores favoring PWS receiving CSC-LT as compared to the NC-LT group (P < .001). Permanent scarring was noted in 3.1% (n = 3) of the patients in the NC-LT group. Permanent scarring was not observed in the CSC-LT treatment group. Transient hyperpigmentation was noted in 57% (n = 56) and 48% (n = 47) of the patients in the NC-LT and CSC-LT groups, respectively. In both groups, the transient hyperpigmentation resolved in all patients within 1 year. Two patients in the NC-LT group developed delayed permanent hypopigmentation. Permanent hypopigmentation was not observed in the CSC-LT group. Conclusion. CSC permitted the use of higher incident light dosages leading to improved PWS clearance without producing complications such as permanent scarring or dyspigmentation.

Thuy L. Phung - One of the best experts on this subject based on the ideXlab platform.

S.w. Lanigan - One of the best experts on this subject based on the ideXlab platform.

  • Acquired port wine Stains: clinical and psychological assessment and response to pulsed dye laser therapy.
    The British journal of dermatology, 1997
    Co-Authors: S.w. Lanigan
    Abstract:

    Nineteen patients are presented with acquired port wine Stains. Acquired port wine Stains are uncommon vascular lesions with the appearance of a congenital port wine Stain but onset after birth. This is the largest group of patients reported to date. The acquired port wine Stain was on the head and neck in 17 patients and in six this was associated with preceding trauma. Psychological assessments in adult patients showed similar morbidity to that seen in patients with congenital port wine Stains. This morbidity was improved with successful laser treatment. Pulsed dye laser therapy resulted in complete clearance of the lesion in six (46%) of 13 patients treated. Two further patients had an excellent response.