Publications by authors named "Pamela Cassidy"

Article Synopsis
  • There is currently no FDA-approved treatment for pityriasis rubra pilaris (PRP), and many patients do not see improvement with existing systemic therapies, highlighting the potential role of interleukin-23 as a therapeutic target.
  • This study aimed to assess the effectiveness of guselkumab, an IL-23p19 inhibitor, in improving PRP symptoms and to explore related gene and protein dysregulation.
  • The trial involved 14 adults, with results showing significant improvements in skin severity and quality of life, where 75% of participants experienced meaningful clinical responses by the end of the 24-week treatment period.
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TR1 and other selenoproteins have paradoxical effects in melanocytes and melanomas. Increasing selenoprotein activity with supplemental selenium in a mouse model of UV-induced melanoma prevents oxidative damage to melanocytes and delays melanoma tumor formation. However, TR1 itself is positively associated with progression in human melanomas and facilitates metastasis in melanoma xenografts.

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Ultraviolet radiation (UVR) exposure is the most important modifiable risk factor for skin cancer development. Although sunscreen and sun-protective clothing are essential tools to minimize UVR exposure, few studies have compared the two modalities head-to-head. This study evaluates the UV-protective capacity of four modern, sun-protective textiles and two broad-spectrum, organic sunscreens ( 30 and 50).

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Pigment-producing melanocytes overcome frequent oxidative stress in their physiological role of protecting the skin against the deleterious effects of solar UV irradiation. This is accomplished by the activity of several endogenous antioxidant systems, including the thioredoxin antioxidant system, in which thioredoxin reductase 1 (TR1) plays an important part. To determine whether TR1 contributes to the redox regulation of melanocyte homeostasis, we have generated a selective melanocytic Txnrd1-knockout mouse model (Txnrd1), which exhibits a depigmentation phenotype consisting of variable amelanotic ventral spotting and reduced pigmentation on the extremities (tail tip, ears, and paws).

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Five years ago, the Melanoma Research Foundation (MRF) conducted an assessment of the challenges and opportunities facing the melanoma research community and patients with melanoma. Since then, remarkable progress has been made on both the basic and clinical research fronts. However, the incidence, recurrence, and death rates for melanoma remain unacceptably high and significant challenges remain.

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We report the first diselenide-based probe for the selective detection of thioredoxin reductase (TrxR), an enzyme commonly overexpressed in melanomas. The probe design involves conjugation of a seminaphthorhodafluor dye with a diselenide moiety. TrxR reduces the diselenide bond, triggering a fluorescence turn-on response of the probe.

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Background: Understanding multiple components of risk perceptions is important because perceived risk predicts engagement in prevention behaviors.

Purpose: To examine how multiple components of risk perceptions (perceived magnitude of and worry about risk, prioritization of the management of one's risk) changed following genetic counseling with or without test reporting, and to examine which of these components prospectively predicted improvements in sun-protection behavior 1 year later.

Methods: A prospective, nonrandomized study design was used.

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Importance: Pityriasis rubra pilaris is a rare and disabling cutaneous disease that is frequently recalcitrant to conventional therapies and appears to involve interleukin (IL)-17 overexpression.

Objective: To investigate the clinical response and safety of ixekizumab in treating pityriasis rubra pilaris.

Design, Setting, And Participants: Single-arm, investigator-initiated trial conducted in adult patients with moderate to severe pityriasis rubra pilaris at a single-center academic university from June 2018 to January 2020.

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Predispositional genetic testing of children for adult-onset health risks is typically only used when prevention and screening measures have utility during childhood. Little is known about how children and their parents may use predispositional risk information, including whether it changes their interactions around risk-reducing prevention and screening behaviors. The current study examined perspectives on family interactions around skin cancer prevention and control practices through 1 year after test reporting and counseling among children who received melanoma predispositional genetic testing and their parents.

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Purpose: This study investigated whether genetic counseling and test reporting for the highly penetrant CDKN2A melanoma predisposition gene promoted decreases in sun exposure.

Methods: A prospective, nonequivalent control group design compared unaffected participants (N = 128, M = 35.24, 52% men) from (1) families known to carry a CDKN2A pathogenic variant, who received counseling about management recommendations and a positive or negative genetic test result and (2) no-test control families known not to carry a CDKN2A pathogenic variant, who received equivalent counseling based on their comparable family history.

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Treatment with vemurafenib, a potent and selective inhibitor of mitogen-activated protein kinase signaling downstream of the BRAF oncogene, elicits dramatic clinical responses in patients with metastatic melanoma. Unfortunately, the clinical utility of this drug is limited by a high incidence of drug resistance. Thus, there is an unmet need for alternative therapeutic strategies to treat vemurafenib-resistant metastatic melanomas.

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In this perspective, we identify emerging frontiers in clinical and basic research of melanocyte biology and its associated biomedical disciplines. We describe challenges and opportunities in clinical and basic research of normal and diseased melanocytes that impact current approaches to research in melanoma and the dermatological sciences. We focus on four themes: (1) clinical melanoma research, (2) basic melanoma research, (3) clinical dermatology, and (4) basic pigment cell research, with the goal of outlining current highlights, challenges, and frontiers associated with pigmentation and melanocyte biology.

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Recent progress in the treatment of advanced melanoma has led to unprecedented improvements in overall survival and, as these new melanoma treatments have been developed and deployed in the clinic, much has been learned about the natural history of the disease. Now is the time to apply that knowledge toward the design and clinical evaluation of new chemoprevention agents. Melanoma chemoprevention has the potential to reduce dramatically both the morbidity and the high costs associated with treating patients who have metastatic disease.

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Article Synopsis
  • Coinheritance of mutations in the CDKN2A gene and the loss-of-function variant in the MC1R gene increases the risk of developing melanoma.
  • Researchers conducted experiments on human melanocyte cultures from individuals with CDKN2A mutations, revealing normal growth and response to UV radiation in most cultures.
  • The study suggests that for melanocytes with both CDKN2A mutations and MC1RLOF variants to become cancerous, they need to acquire additional mutations, influenced by their genetic environment or surrounding cell types.
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Broccoli sprout extract containing sulforaphane (BSE-SFN) has been shown to inhibit ultraviolet radiation-induced damage and tumor progression in skin. This study evaluated the toxicity and potential effects of oral BSE-SFN at three dosages. Seventeen patients who each had at least 2 atypical nevi and a prior history of melanoma were randomly allocated to 50, 100, or 200 μmol oral BSE-SFN daily for 28 days.

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Genetic testing of minors is advised only for conditions in which benefits of early intervention outweigh potential psychological harms. This study investigated whether genetic counseling and test reporting for the CDKN2A/p16 mutation, which confers highly elevated melanoma risk, improved sun protection without inducing distress. Eighteen minors (M = 12.

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We demonstrate that SCF-KIT signaling induces synthesis and secretion of endothelin-3 (ET3) in human umbilical vein endothelial cells and melanoma cells in vitro, gastrointestinal stromal tumors, human sun-exposed skin, and myenteric plexus of human colon post-fasting in vivo. This is the first report of a physiological mechanism of ET3 induction. Integrating our finding with supporting data from literature leads us to discover a previously unreported pathway of nitric oxide (NO) generation derived from physiological endothelial NO synthase (eNOS) or neuronal NOS (nNOS) activation (referred to as the KIT-ET3-NO pathway).

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Article Synopsis
  • Melanoma is a serious type of skin cancer that can be easily found by doctors during skin examinations, but it causes most skin cancer deaths.
  • There aren't clear national rules about when people should get checked for skin cancer in the USA, leaving doctors to make important choices.
  • This paper aims to suggest better guidelines for skin cancer screening based on research, compare them to other organizations' recommendations, and look at an earlier suggestion by the US Preventive Services Task Force.
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Several distinct melanoma syndromes have been defined, and genetic tests are available for the associated causative genes. Guidelines for melanoma genetic testing have been published as an informal "rule of twos and threes," but these guidelines apply to CDKN2A testing and are not intended for the more recently described non-CDKN2A melanoma syndromes. In order to develop an approach for the full spectrum of hereditary melanoma patients, we have separated melanoma syndromes into two types: "melanoma dominant" and "melanoma subordinate.

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Southern right whales (SRWs, Eubalena australis) are polymorphic for an X-linked pigmentation pattern known as grey morphism. Most SRWs have completely black skin with white patches on their bellies and occasionally on their backs; these patches remain white as the whale ages. Grey morphs (previously referred to as partial albinos) appear mostly white at birth, with a splattering of rounded black marks; but as the whales age, the white skin gradually changes to a brownish grey color.

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Oxidative stress plays a role in UV-induced melanoma, which may arise from melanocytic nevi. We investigated whether oral administration of the antioxidant N-acetylcysteine (NAC) could protect nevi from oxidative stress in vivo in the setting of acute UV exposure. The minimal erythemal dose (MED) was determined for 100 patients at increased risk for melanoma.

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Efforts to prevent melanoma, especially for those at elevated risk for the disease, should ideally begin during childhood. However, there are few preventive interventions targeting children who are at higher risk for melanoma due to a family history of the disease. Further, there are no educational interventions that aim to help these at-risk children understand their risk for melanoma and the ways in which preventive behaviors, such as sun protection, can mitigate their risk.

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