Daniel Barolet

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Verified

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• MD FRCPC
• Faculty Lecturer at McGill University

Introduction Recent findings show that visible light, particularly blue light, stimulates melanogenesis in human skin, though the underlying mechanisms remain debated. This study aimed to determine the cell damage threshold of non-ionizing blue light on keratinocytes while preserving their ability to stimulate melanogenesis. Methods Human keratino...

NO is a crucial signaling molecule involved in skin health, the immune response, and the protection against environmental stressors. This study explores how different wavelengths of light, namely blue (455 nm), red (660 nm), and near infrared (NIR, 850 nm), affect nitric oxide (NO) production in skin cells. Primary keratinocytes and fibroblasts fro...

Significance: This study investigates the therapeutic potential of photobiomodulation (PBM) using visible and near-infrared (NIR) light on nitric oxide (NO) release from intact human skin. Given NO’s critical role in physiological processes such as wound healing, inflammation control, and vasodilation, this research could lead to innovative non-inv...

Objective: This study aimed to investigate the effectiveness of prophylactic photobiomodulation (PBM) in reducing postinflammatory hyperpigmentation (PIH) induced by carbon dioxide (CO2) laser resurfacing in a patient with periorbital syringomas. Background: PIH is a common condition characterized by abnormal skin pigmentation after an inflammator...

Objective: To describe current knowledge regarding established and putative cell signaling pathways involved in skin photobiomodulation. Background: The skin is the largest and most accessible organ of the body. It is the first line of defense against the external environment, including solar radiation. Among solar rays, visible and infrared non-i...

Infrared light (760 nm-1 mm) constitutes approximately 40% of the solar radiation reaching the ground at sea level. Shortest wavelength near-infrared (NIR) photons (NIR or IR-A: 760-1,400 nm) can penetrate the epidermis, dermis, and subcutaneous tissue with numerous biological effects. NIR used to have a bad reputation on the basis of past studies...

Nitric oxide (NO) is omnipresent in the body and synthesized by 3 isoenzymes (nNOS, eNOS and iNOS), all detected in human skin. NO can be stored in a pool of compounds readily converted to NO following skin irradiation by UVR and blue light. This non-enzymatic (without NOS involvement) photolytic reaction mobilizes cutaneous stores of NO derivative...

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder that may be treated with non-ablative light-based devices; however, no systematic reviews on the topic exist to date. We conducted a systematic review and meta-analysis to determine efficacy of non-ablative light-based devices in treating HS. Specifically, a systematic review was...

Background: Linear morphea is a variant of scleroderma limited to the skin and underlying tissues secondary to an autoimmune inflammation leading to excess collagen deposition and fibrosis. Apart from topical or oral medications, successful light-based treatments have been reported using phototherapy including Psoralen plus ultraviolet A, photodyna...

Facial multiple miliary osteoma cutis is a variant of osteoma cutis usually occurring in women with a previous history of acne vulgaris. Successful ablative laser treatment has been reported using both CO2 and Er:YAG lasers among other invasive treatment modalities, like surgical removal. We report a patient with biopsy-proven facial multiple milia...

Human skin contains photolabile nitric oxide (NO) derivatives which decompose after UVA irradiation and release vasoactive NO. However, aside from blue light, barely nothing has been reported about the effects of red and NIR wavelengths. We decided to investigate if photobiomodulation, using visible to NIR light, would increase the release of NO in...

Background Jet injection can be defined as a needle-free drug delivery method in which a high-speed stream of fluid impacts the skin and delivers a drug. Despite 75 years of existence, it never reached its full potential as a strategic tool to deliver medications through the skin. Objective The aim of this review was to evaluate and summarize the...

Overview. Melasma is a resistant, sun-induced facial hyperpigmentation capable of remaining present for decades with ensuing psychological distress. Treatment is difficult and focuses on an array of measures to reduce skin hyperpigmentation resulting from triggered hyperactive melanocytes. The pathogenesis of melanoma is not clearly understood but...

Photobiomodulation (PBM), the therapeutic use of low intensity light, typically in the visible and infrared (IR) wavelengths, has been demonstrated to be efficacious in the treatment and prevention of numerous skin conditions. The PBM biological response begins with chromophores, photon accepting molecules which convert light into signals that can...

Ablative cosmetic procedures are almost inevitably followed by an acute healing phase resulting in discomfort, erythema, edema, and crusting. Since patients are constantly asking for no downtime procedures, a considerable challenge to health care providers has resulted. Recently, photobiomodulation (PBM) with light-emitting diodes has attracted att...

LED photobiomodulation is known mostly for its restorative effects on skin and joints. While providing LED photobiomodulation aesthetic treatments of the face, not only the skin condition was improved, but a subjective well-being effect was observed, obvious both in photographs of the treated areas and in patient behaviour. This has been supported...

In the last decade, it has been proposed that the sun's IR-A wavelengths might be deleterious to human skin and that sunscreens, in addition to their desired effect to protect against UV-B and UV-A, should also protect against IR-A (and perhaps even visible light). Several studies showed that NIR may damage skin collagen content via an increase inM...

Limited cutaneous systemic sclerosis (lcSSc) was formerly known as CREST syndrome in reference to the associated clinical features: calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasias. The transforming growth factor beta has been identified as a major player in the pathogenic process, where low-level light t...

High fluence diode lasers with contact cooling have emerged as the mainstay modality for hair removal. However, the use of these devices is associated with pain and side effects, especially in patients with dark or tanned skin. A novel concept of depilation at low fluence using 810 nm diode laser has been introduced as a solution to these shortcomi...

Limited cutaneous systemic sclerosis (lcSSc) was formerly known as CREST syndrome in reference to the associated clinical features: Calcinosis, Raynaud's phenomenon, Esophageal dysfunction, Sclerodactyly, and Telangiectasias. The transforming growth factor beta (TGF-β) has been identified has a major player in the pathogenic process, while low leve...

Photodynamic therapy (PDT) with aminolevulinic acid (ALA) to treat nodular basal cell carcinoma (BCC) has been shown to be beneficial. The success rate of ALA-PDT in the treatment of nodular BCC is dependent on optimal penetration of the photosensitizing agent and subsequent PpIX production. To enhance topical delivery of drugs intradermally, a nee...

Hypertrophic and keloid scars result from alterations in the wound healing process. Treating abnormal scars remains an important challenge. The aim of this case series was to investigate the effectiveness of near infrared (NIR) light emitting diode (LED) treatment as a prophylactic method to alter the wound healing process in order to avoid or atte...

The influence of emission parameters in low-level-light therapy on cellular responses is not yet fully understood. This study assessed the impact of various light delivery modes on collagen production in human primary fibroblast cultured in monolayers after three treatments with red light-emitting diode illumination (630 nm, 8 J/cm(2)). Human type...

The influence of emission parameters in Low Level Light Therapy (LLLT) on cellular responses is not yet fully understood. This study assessed the impact of various light delivery modes on collagen production in human primary fibroblast cultured in monolayers after three treatments with red light emitting diode illumination (630 nm, 8 J/cm2). Human...

The influence of emission parameters in Low Level Light Therapy (LLLT) on cellular responses is not yet fully understood. This study assessed the impact of various light delivery modes on collagen production in human primary fibroblast cultured in monolayers after three treatments with red light emitting diode illumination (630 nm, 8 J/cm2). Human...

An alternative approach in the treatment of acne vulgaris is photodynamic therapy (PDT) that uses light and aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) production to eradicate Propionibacterium acnes found in acne lesions. PpIX formation is dependent on ALA percutaneaous penetration. In this study, to enhance ALA penetration and subs...

It has been reported that skin aging is associated with a downregulation in collagen synthesis and an elevation in matrix metalloproteinase (MMP) expression. This study investigated the potential of light-emitting diode (LED) treatments with a 660 nm sequentially pulsed illumination formula in the photobiomodulation of these molecules. Histological...

Melasma is a common dermatological skin disease that can now be treated by fractional photothermolysis (fractional resurfacing). Past studies have shown that thermal spring water (TSW) spray can reduce local inflammatory symptoms after dermatological surgery, laser surgery or chemical peelings. The aim of this study was to evaluate the clinical eff...

Light-emitting diode photobiomodulation is the newest category of nonthermal light therapies to find its way to the dermatologic armamentarium. In this article, we briefly review the literature on the development of this technology, its evolution within esthetic and medical dermatology, and provide practical and technical considerations for use in...

Background and Objectives As photoprotection with traditional sunscreen presents some limitations, the use of non-traditional treatments to increase skin resistance to ultraviolet (UV) induced damage would prove particularly appealing. The purpose of this pilot study was to test the potential of non-thermal pulsed light-emitting diode (LED) treatme...

Cutaneous photobiology principles are taking shape now that high-power LED-based devices are becoming available, as their high power density allows us to surpass the non-thermal cellular activation threshold. Such LED devices, the fruit of leading edge research, extend the repertoire of medical and cosmetic applications. The present paper explores...

Background and Objectives: Actual non-ablative thermal technologies induce micro-injuries and tissue repair mechanisms to enhance collagen production. Conversely, the improvement in skin appearance following LED-based therapy results from increased collagen production by dermal fibroblasts without thermal injury. The assumed effect is the selective...

There are many clinical presentations to fibrofolliculoma, described by Birt, Hogg and Dubé: the solitary and multiple forms, with or without other skin tumors, could also be markers of intestinal polyposis. Little is known of its pathogenesis. A case of multiple fibrofolliculoma of the face and neck is described. A new therapeutic approach by copp...

Urticaria is often incapacitating, yet it is not always easy to know whether a patient should undergo testing and what treatment should be prescribed. This article provides a systematic approach to urticaria and its treatment.