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1.
J Med Case Rep ; 15(1): 367, 2021 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-34256861

RESUMEN

BACKGROUND: We present an unusual case of a patient who developed four melanomas within a few months of diagnosis with human immunodeficiency virus and commencement of highly active antiretroviral therapy therapy. The patient had no previous history of melanoma, and previous skin checks were normal. CASE PRESENTATION: A 50-year-old Caucasian male drainlayer with Fitzpatrick type 2 skin presented for a routine skin examination. He had been diagnosed with human immunodeficiency virus 4 months earlier and commenced on highly active antiretroviral therapy therapy. He was found to have three melanomas (melanoma in situ stage) on excision biopsies, and when he presented for wider excisions of these sites a few weeks later, another new melanoma in situ was found. He had no other medical history of note, and no symptoms to report. He is being followed up 3-monthly. CONCLUSIONS: This case of a human immunodeficiency virus-positive person presenting with four cutaneous melanomas-occurring in both synchronous and metachronous fashion within a 4-month period-is being presented both for its uniqueness and also to highlight the increased need for close skin surveillance in human immunodeficiency virus-positive patients.


Asunto(s)
Seropositividad para VIH , Melanoma , Neoplasias Cutáneas , Terapia Antirretroviral Altamente Activa , VIH , Humanos , Masculino , Melanoma/complicaciones , Melanoma/tratamiento farmacológico , Persona de Mediana Edad , Neoplasias Cutáneas/tratamiento farmacológico
2.
J Opt Soc Am A Opt Image Sci Vis ; 37(5): 807-812, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32400714

RESUMEN

Melanoma is the severest type of skin cancer. As distinct from many other cancer types, the incidence of melanoma has been increasing steadily over the last century. Discovering new risk factors of melanoma will not only raise public awareness but also potentially contribute to the improvement of skin cancer protection in the future. Nowadays, the tendency of shaving skin hair is becoming increasingly popular for aesthetic purposes. However, human hair serves several functions, one of which is ultraviolet (UV) protection for the skin. What is more, stem cells found in the follicles of hair could be the origin of melanoma upon exposure to ultraviolet radiation. Therefore, it is of interest to investigate the effect of shaving on solar UV transmission in the skin. To achieve that, two groups of skin models are constructed in TracePro software: one with unaltered hair and one with shaved hair. The UV transport in the models is simulated using the Monte Carlo method and the absorptions in the stem cells layer are compared. It is found that shaving will increase the UV transmission to the follicular stem cells to a certain degree. More specifically, shaving limbs will generally increase the solar UV transmission from about 5% to 20% in the UV wavelength range.


Asunto(s)
Remoción del Cabello , Melanoma/etiología , Neoplasias Inducidas por Radiación/etiología , Neoplasias Cutáneas/etiología , Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversos , Folículo Piloso , Humanos , Modelos Teóricos , Método de Montecarlo , Absorción Cutánea , Luz Solar/efectos adversos
3.
Front Med (Lausanne) ; 6: 195, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31552252

RESUMEN

When people think about sun-protection or prevention of skin cancer, sunscreens readily come to mind. Sunscreen effectiveness is tested in vivo by the ability to prevent erythema of skin, yet testing methods vary between markets, and many sunscreens fail to achieve their claims. This article discusses the mechanism of action of sunscreens, Sun Protection Factor (SPF), safety concerns and the challenges for regulators. Many sunscreens that prevent erythema do not provide adequate protection as they contain anti-inflammatory agents; others have ingredients whose risks have not been fully evaluated. This article reviews the imperfect science behind sunscreens and points out the gaps in knowledge regarding safety, efficacy, public knowledge, and perception. Regulations vary between countries and only adds to the confusion. To truly prevent skin cancer, clinicians, formulators and regulators need to come together to research more and improve public education.

4.
Ann Biomed Eng ; 47(12): 2372-2383, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31290037

RESUMEN

Melanoma is the deadliest type of skin cancer with its prevalence on the rise. Recently, the melanocyte stem cells in hair follicles have been identified as the possible origin of melanoma upon exposure to ultraviolet radiation (UVR) through skin. It is hypothesized that colourless vellus hair (predominant in childhood) can serve as an alternative pathway in transmitting these ultraviolet (UV) photons to the stem cells. To investigate this, we have used the CRAIC microspectrophotometer to investigate the optical properties of 'vellus-like' hairs and terminal hairs of different colours using UV-VIS-NIR light sources. It was found that the average attenuation coefficient of 'vellus-like' hair is significantly lower than that of terminal hair in the UVA (p < 0.0001) and UVB (p < 0.001) wavelength ranges. Next, the optical properties of hairs are applied to simulations for examining their influence on UV transmission into the skin. The results show that the presence of vellus hair would increase the solar UV transmission to the melanocyte stem cell layer significantly. The findings explain why children are particularly vulnerable to sun exposure and the positive correlation found between the incidence of melanoma in adults' bodies and the number of vellus hairs in these areas.


Asunto(s)
Cabello , Rayos Ultravioleta , Adulto , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Melanoma , Persona de Mediana Edad , Piel/efectos de la radiación , Neoplasias Cutáneas , Espectrofotometría , Adulto Joven
5.
J Opt Soc Am A Opt Image Sci Vis ; 36(4): 628-635, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-31044982

RESUMEN

The incidence of melanoma in children is extremely rare. However, there is convincing evidence supporting a higher risk of developing melanoma in individuals who have experienced excessive sun exposure during their childhood. A possible explanation for this phenomenon is that prior to puberty, the melanocyte stem cells in the bulge region of hair follicles are much shallower in the dermis, resulting in their increased vulnerability to sun exposure. To validate this hypothesis, a Monte Carlo simulation of light transport is applied to quantify the dose of solar UV power absorbed in the stem-cell layers at different depths in both child and adult skins. The simulated results suggest that the stem cells in vellus hair follicles would absorb over 250 times higher UV photons than those in the terminal hair follicles. Due to the thinner epidermis in child skin, the stem cells in vellus hair follicles absorb about 1.9 and 3.2 times greater ultraviolet A and ultraviolet B, respectively, than those in adult skin. These findings provide a possible explanation to why children are particularly vulnerable to sun exposure.


Asunto(s)
Folículo Piloso/patología , Melanoma/patología , Modelos Biológicos , Exposición a la Radiación/efectos adversos , Células Madre/patología , Células Madre/efectos de la radiación , Rayos Ultravioleta/efectos adversos , Absorción de Radiación , Carcinogénesis/efectos de la radiación , Humanos , Método de Montecarlo , Piel/patología , Piel/efectos de la radiación
6.
J Biomed Opt ; 23(5): 1-9, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29752798

RESUMEN

Immigration and epidemiological studies provide evidence indicating the correlation of high ultraviolet exposure during childhood and increased risks of melanoma in later life. While the explanation of this phenomenon has not been found in the skin, a class of hair has been hypothesized to be involved in this process by transmitting sufficient ultraviolet rays along the hair shaft to possibly cause damage to the stem cells in the hair follicle, ultimately resulting in melanoma in later life. First, the anatomy of hair and its possible contribution to melanoma development, and the tissue optical properties are briefly introduced to provide the necessary background. This paper emphasizes on the review of the experimental studies of the optical properties of human hair, which include the sample preparation, measurement techniques, results, and statistical analysis. The Monte Carlo photon simulation of human hair is next outlined. Finally, current knowledge of the optical studies of hair is discussed in the light of their possible contribution to melanoma development; the necessary future work needed to support this hypothesis is suggested.


Asunto(s)
Cabello , Investigación Biomédica , Cabello/anatomía & histología , Cabello/diagnóstico por imagen , Cabello/fisiología , Cabello/efectos de la radiación , Humanos , Melanoma , Microscopía Confocal , Neoplasias Cutáneas , Espectrofotometría , Rayos Ultravioleta
7.
Case Rep Dermatol Med ; 2017: 1536434, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29119028

RESUMEN

Follicular urate-like crystals were first described in Necrotizing Infundibular Crystalline Folliculitis (NICF), a rare cutaneous disorder with multiple waxy folliculocentric papules. Similar crystal accumulation may be seen within follicular infundibulae as an incidental finding. We describe a case showing identical crystals occurring within the horn-like crusts of a patient with erosive pustular dermatosis of the scalp (EPDS), a condition which due to its presentation can often be mistaken for nonmelanoma skin cancer. A brief overview of erosive pustular dermatosis of the scalp (EPDS) is presented in this paper.

8.
Arch Plast Surg ; 44(3): 243-247, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28573101

RESUMEN

Reconstruction of the lower limb presents a complex problem after skin cancer surgery, as proximity of skin and bone present vascular and technical challenges. Studies on vascular anatomy have confirmed that the vascular plane on the lower limb lies deep to the deep fascia. Yet, many flaps are routinely raised superficial to this plane and therefore flap failure rates in the lower limb are high. Fascio-cutaneous flaps based on perforators offer a better cosmetic alternative to skin grafts. In this paper, we detail use of a thermal imaging camera to identify perforator 'compartments' that can help in designing such flaps.

9.
Plast Reconstr Surg Glob Open ; 5(12): e1614, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29632788

RESUMEN

BACKGROUND: Closing of defects of the lower limb after skin cancer excision poses a challenge in lower limb skin. Although the concept of relaxed skin tension lines has been established as ideal on the face, on the lower limb there remains confusion between Langer's lines and wrinkle lines, and this study was done with the task of identifying and mapping biodynamic excisional skin tension (BEST) lines on the lower limb. METHODS: Following studies on BEST lines elsewhere on the body, the author investigated BEST lines on the lower limb. Using a specially designed tensiometer, inherent skin tension (pretension) and wound-closing tension were studied along with the force needed to bring the wound edges together after excision of a lesion in 23 cases with defects ranging from 1.5 to 4.5 cm in diameter. Skin tension measurements of skin lines (relaxed skin tension lines (RSTL) versus BEST) and vertical closure (BEST) versus vertical closure with a parallel relaxing incision were undertaken and followed by statistical analyses utilizing the paired t test and the unpaired Student's t tests. RESULTS: BEST lines run in the vertical direction on the lower limb, that is, closure in a vertical direction resulted in a statistically significant reduction in closing tension when compared with other directions. Using a parallel relaxing incision can offer further reduction in tension, if needed. CONCLUSION: BEST lines of the lower limb are discussed, and a new technique of using parallel relaxing incisions to achieve closure of larger defects is also presented as an alternative to cutaneous flaps or grafts in the lower limb.

10.
Front Surg ; 3: 63, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27900320

RESUMEN

This paper details the study of biodynamic excisional skin tension lines on the scalp and the development of a new flap technique for closure of scalp wounds. Recently, a study by this author, on pigskin, replicated whorls by placing tissue under rapid stretch using saline tissue expanders, by recreating rapid dermo-epidermal shear of skin - thereby concluding that the golden spiral pattern is nature's own pattern for rapid expansion. Given the relationship between tissue expansion and stretch has been shown to cause deformation gradients that have both elastic and growth factors, the author set out to test the hypothesis that a golden spiral pattern therefore would be more efficient at closing wounds under less tension when compared with standard semicircular rotational flap patterns. The author conducted a series of experiments, both on pigskin (to first confirm the hypothesis, using a recently developed computerized tensiometer) and later a clinical study. This paper presents a new random pivotal flap technique for skin closures on the head and neck: the golden spiral flap. Biomechanics, planning, and advantages of this new flap are described in this paper.

11.
PLoS One ; 11(9): e0162026, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27583520

RESUMEN

This paper documents what began as an exercise in curiosity-logarithmic spiral designs abound in nature-in galaxies, flowers, even pinecones, and on human scalps as whorls. Why are humans the only primates to have whorls on the scalp? Is the formation of scalp whorls mechanical or genetic? A mechanical theory has long been postulated- the mechanical theory suggests that hair whorl patterning is determined by the tension on the epidermis during rapid expansion of the cranium while the hair follicle is growing downwards-however, this has never before, to the author's knowledge, been experimentally proven conclusively. We found, that under certain conditions, we were able to experimentally recreate spirals on the scalp to demonstrate that the basis of scalp whorls is indeed mechanical-and that logarithmic spirals may be nature's own design for rapid expansion of organic tissues. Given our experiments only created whorls when certain conditions were satisfied (and not in others), they have given us great insight into the mechanical formation of skin whorls and the physiology of skin stretch. We believe that these findings will lead to many more advances in understanding skin dynamics and indeed the changes that occur in tissue when confronted by stretch.


Asunto(s)
Cuero Cabelludo , Piel/anatomía & histología , Piel/crecimiento & desarrollo , Animales , Resistencia al Corte , Porcinos
12.
Sci Rep ; 6: 30117, 2016 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-27453542

RESUMEN

One of the problems in planning cutaneous surgery is that human skin is anisotropic, or directionally dependent. Indeed, skin tension varies between individuals and at different body sites. Many a surgeon has tried to design different devices to measure skin tension to help plan excisional surgery, or to understand wound healing. However, many of the devices have been beset with problems due to many confounding variables - differences in technical ability, material (sutures) used and variability between different users. We describe the development of a new skin tensiometer that overcomes many historical technical issues. A new skin tension measuring device is presented here. It was designed to be less user-dependent, more reliable and usable on different bodily sites. The design and computational optimizations are discussed. Our skin tensiometer has helped understand the differences between incisional and excisional skin lines. Langer, who pioneered the concept of skin tension lines, created incisional lines that differ from lines caused by forces that need to be overcome when large wounds are closed surgically (excisional tension). The use of this innovative device has led to understanding of skin biomechanics and best excisional skin tension (BEST) lines.


Asunto(s)
Piel/fisiopatología , Técnicas de Sutura/instrumentación , Humanos , Suturas , Cicatrización de Heridas/fisiología
13.
Case Rep Med ; 2014: 267535, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25431597

RESUMEN

Imiquimod belongs to the class of 1H-imidazo-[4,5-c]quinolones-drugs originally developed as nucleoside analogues with the aim of finding new potential antiviral agents (Harrison et al., 1988). Indeed, Imiquimod was first released as treatment for genital warts before its actions against skin cancer were studied. Imiquimod is a relatively small sized molecule (Mr = 240.3) and is hydrophobic, allowing it to penetrate the skin epidermal barrier and therefore making it suitable for topical formulations (Gerster et al., 2005). Imiquimod has shown itself effective against skin cancers and precancerous lesions, especially basal cell cancers and actinic keratosis (Salasche et al., 2002, Beutner et al., 1999). There have been reports of Imiquimod being used as topical treatment against cutaneous metastases of melanoma and some authors have reported its use as first-line therapy against melanoma in situ (Smyth et al., 2011, Gagnon, 2011). We report a case of an invasive malignant melanoma arising de novo at the specific site of application of Imiquimod (Aldara cream 5%) for a biopsy-proven superficial BCC. Therefore while Imiquimod has added to our topical armamentarium against skin cancer, care must be exercised in prescribing this treatment and it is especially important to follow up patients regularly.

14.
Case Rep Oncol Med ; 2014: 206260, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24716040

RESUMEN

The ABCD acronym used to screen pigmented lesions for melanoma obviously was not designed to contend with melanomas that are under 2 mm in diameter. Previously, views ranged that such small lesions could not be melanomas until a few reports of such "micromelanomas" emerged. The author presents a 2 mm melanoma in situ presenting as an insignificant pigmented lesion in a 60-year-old patient with no previous history of melanoma or multiple nevi-which is usually the norm in cases of small melanoma. This paper reiterates the fact that when it comes to a melanoma, size does not matter. In this paper, the term "micromelanoma" is used by the author to represent melanomas under 2 mm. Dermatoscopy and histopathology findings are discussed in this case, along with a review of small melanomas.

15.
Case Rep Dermatol Med ; 2013: 109308, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24066243

RESUMEN

Granular cell tumours, first described by Abrikossoff in 1926, are known to occur in skin, connective tissue, breast, gastrointestinal and genital tracts. While they are rare, they are more common in people of African descent and show a slight female preponderance, usually presenting as solitary and painless masses. Less than 10% of occurrences are multiple, and fewer than 3% of tumours behave in a malignant fashion. The mean age, at presentation, is 40-60 years. We report a case of granular cell tumour in a young white male presenting with a painful soft tissue tumour in his buttock. The presentation is unusual because of the age, patient demographic, body site, and clinical presentation. The clinical and histological aspects are reviewed in the context of this clinical case and the associated literature.

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