Exogenous Pigments Research Articles

Histological lesions induced by exogenous pigment in dyed Indian glassfish, Pseudambassis ranga (Hamilton)

Histological lesions induced by exogenous pigment in dyed <scp>I</scp>ndian glassfish, <i><scp>P</scp>seudambassis ranga</i> (<scp>H</scp>amilton)

Influence of exogenous pigmentation on the optical properties of orthodontic elastic ligatures

ObjectivesThe aim of this study was to assess the optical properties of orthodontic elastic ligatures under the influence of exogenous pigments contained in the daily diet. Material and methodsFor the analysis, colorless (clear) elastic segments (ORTHO Organizers, lot 660625A10) were used as received from the manufacturer, and were divided into 8 groups of 3 segments each. Each group was immersed in 200 mL of a solution containing a determined substance, as follows: distilled water (control group), Coca-Cola®, Pomarola brand tomato sauce (Cica®), açai, Jasmine® brand green tea, Royal Blend® black tea brand, Pilão® brand coffee and Palmares® wine brand. All test specimens were immersed in the solutions and kept in an appropriate receptacle for 7 days at 37ºC14. After the staining session, the test specimens were washed with distilled water in an ultrasonic vat for 5 min and dried with paper tissues6. The portable digital spectrophotometer Vita Easyshade Compact was used to assess if there was color variation of the test specimens. This variation was quantified and qualified at the initial time (T0) and after staining (T1). ResultsThese results were analyzed statistically using the software SPSS version 18.0. The Shapiro-Wilk test of normality was applied followed by the one-way analysis of variance and the Tukey's post hoc test. The level of significance adopted was 5%. ConclusionsFrom the substances evaluated in this study, those with higher staining potential on esthetic elastic ligatures were black tea, coffee and wine, respectively. Knowing this information, the dentist may advise their patients to avoid certain foods because of elastic staining may occur thus decreasing the aesthetics of the material.

Cutaneous amalgam tattoo in a dental professional: an unreported occupational argyria

Funding sources: This work was supported by the Brazilian Federal Agency of Support and Evaluation of Postgraduate Education (CAPES). Conflicts of interest: none declared. Madam, Amalgam tattoo is the most common exogenous pigmentation of the oral mucosa1, 2; surprisingly, there are no reports of similar lesions on the skin. It is caused by traumatic implantation of amalgam fragments into the oral mucosa following dental treatment, particularly when amalgam fillings are removed with high‐speed instruments. Amalgam tattoo occurs mostly in the gingiva and alveolar mucosa. Clinically it presents as an asymptomatic bluish to black macule, eventually observed by the patient or discovered during routine dental treatment. Histologically it shows brown to black aggregates of granules interspersed among collagen fibres and around blood vessels. Most cases show a slight inflammatory response, and eventually a foreign body granulomatous reaction is found.1–4 Cases of cutaneous localized argyria are uncommon, and are usually attributed to trauma, acupuncture, topical silver‐based medication or use of pieces of jewellery such as earrings.5–7 We report a case of cutaneous amalgam tattoo caused by implantation of amalgam particles on the skin of the eyebrow of a dental surgeon.

Tattoos, inks, and cancer

The introduction in the dermis of exogenous pigments and dyes to obtain a permanent design (tattooing) represents a unique in-vivo situation, where a large amount of metallic salts and organic dyes remain in the skin for the lifetime of the bearer. The potential local and systemic carcinogenic effects of tattoos and tattoo inks remain unclear. Several studies have shed light on the presence of potential carcinogenic or procarcinogenic products in tattoo inks. We extensively reviewed the literature and found 50 cases of skin cancer on tattoos: 23 cases of squamous-cell carcinoma and keratoacanthoma, 16 cases of melanoma, and 11 cases of basal-cell carcinoma. The number of skin cancers arising in tattoos is seemingly low, and this association has to be considered thus far as coincidental.

Treating rhinophyma: A case report illustrating decortication/vaporization with an 808-nm diode laser

AbstractRhinophyma is a skin disease that is not only disfiguring but can also have a negative impact on respiratory function by causing nasal obstruction. There is a wide range of techniques used in the surgical management of rhinophyma, including laser treatment, all of which involve tissue ablation. With regard to the laser therapy, there is no consensus as to which laser is most effective. The authors present a case report to illustrate their method of treating rhinophyma with an 808-nm diode laser, which included the use of exogenous pigment to define the target area and the application of human fibrin glue to obtain good hemostasis and wound healing and prevent infection.

Benign Dermoscopic Parallel Ridge Pattern Variants

T HE PARALLEL RIDGE PATTERN (PRP) IS A VOlar dermoscopic pattern that is characterized by an accentuated pigmentation on the ridges of the skin markings, while the furrows are hypopigmented or unpigmented. It has been demonstrated to be highly specific for acral melanoma, and its presence must be considered a warning sign of melanoma. However, rare cases of benign acral melanocytic nevus can exhibit the PRP, as in the edge of the compound melanocytic nevus shown in Figure1A. The acral blue nevus (Figure 1B) usually shows a bluish, quite homogeneous pigmentation involving the ridges. Ethnic pigmentation clinically presents as pigmented macules with a typical PRP on the palms and soles (Figure2A). The multiplicity, bilateral location, and chronicity of the lesions are suggestive of ethnic-type pigmentation. The presentation is similar in Laugier-Hunziker or Peutz-Jeghers syndrome. Ectasic papillary capillaries of acral angioma present as regular red-blue globules along the ridges (Figure 2B). Repetitive microtrauma can cause extravasation of erythrocytes in the cornified layer, with subsequent misleading globular reddish brown pigmentation on the ridges, as seen in Figure 3A, which shows a posttraumatic purpura due to the friction of the fifth finger caused by regular use of the computer mouse. The PRP was also found in subcorneal hematoma. The lesion appears as well-demarcated roundish macule, with reddish brown pigmentation along the ridges (Figure 3B). Deposit of exogenous pigmentation on the ridges, especially in areas where the stratum corneum is thicker, can also simulate melanoma, as shown in Figure 4, with the use of a self-tanning preparation by a woman with localized palmar hyperkeratosis.

Dental pathology in dolphins (Cetacea: Delphinidae) from the southern coast of Brazil

Pathological processes observed in the stomatognathic systems of mammalian species are a useful source of information about the habits, evolution and general health of such animals. Studies of pathological conditions on teeth are common in humans and other primates, but rare in wild animals in general and marine mammals in particular. For cetaceans, previous studies provided scanty records of dental anomalies in a few species. This is the first broad and systematic inventory of dental pathology in dolphins. Specimens stored at scientific collections from the southern coast of Brazil were visually inspected under a stereoscopic microscope using a dental explorer. Diagnosis of lesions and anomalies followed literature descriptions. Abnormalities such as caries-like lesions, mineralized calculus deposits, dental erosion, enamel anomalies (hypoplasia and exogenous pigmentation), root resorption, germination and other shape anomalies, were diagnosed in the delphinids Sotalia guianensis, Delphinus capensis, Stenella frontalis, Stenella coeruleoalba, Lagenodelphis hosei, Pseudorca crassidens, Orcinus orca, Steno bredanensis and Tursiops truncatus. Endogenous causes may be related to the occurrence of certain conditions, but the aetiology of caries-like lesions and calculus accumulation is still unknown for cetaceans. The diagnosis of alveolar anomalies and other bone lesions in specimens with dental pathology lead us to believe these lesions modify the integrity of the periodontal ligament and bony tissues, adding to the burden of morbidity of affected animals.

Prodigiosin from Vibrio sp. DSM 14379; A New UV-Protective Pigment

Pigments such as melanin, scytonemin and carotenoids protect microbial cells against the harmful effects of ultraviolet (UV) radiation. The role in UV protection has never been assigned to the prodigiosin pigment. In this work, we demonstrate that prodigiosin provides a significant level of protection against UV stress in Vibrio sp. DSM 14379. In the absence of pigment production, Vibrio sp. was significantly more susceptible to UV stress, and there was no difference in UV survival between the wild-type strain and non-pigmented mutant. The pigment's protective role was more important at higher doses of UV irradiation and correlated with pigment concentration in the cell. Pigmented cells survived high UV exposure (324J/m(2)) around 1,000-fold more successfully compared to the non-pigmented mutant cells. Resistance to UV stress was conferred to the non-pigmented mutant by addition of exogenous pigment extract to the growth medium. A level of UV protection equivalent to that exhibited by the wild-type strain was attained by the non-pigmented mutant once the prodigiosin concentration had reached comparable levels to those found in the wild-type strain. In co-culture experiments, prodigiosin acted as a UV screen, protecting both the wild-type and non-pigmented mutants. Our results suggest a new ecophysiological role for prodigiosin.

The contribution of structural‐, psittacofulvin‐ and melanin‐based colouration to sexual dichromatism in Australasian parrots

Colour ornamentation in animals is exceptionally diverse, but some colours may provide better signals of individual quality or more efficient visual stimuli and, thus, be more often used as sexual signals. This may depend on physiological costs, which depend on the mechanism of colour production (e.g. exogenously acquired colouration in passerine birds appears to be most sexually dichromatic). We studied sexual dichromatism in a sample of 27 Australasian parrot species with pigment- (melanin and psittacofulvin) and structural-based colouration, to test whether some of these types of colouration are more prominent in sexual ornamentation. Unlike passerines, in which long wavelength colouration (yellow to red) usually involves exogenous and costly carotenoid pigments, yellow to red colouration in parrots is based on endogenously synthesized psittacofulvin pigments. This allows us to assess whether costly exogenous pigments are necessary for these plumage colours to have a prominent role in sexual signalling. Structural blue colouration showed the largest and most consistent sexual dichromatism, both in area and perceptually relevant chromatic differences, indicating that it is often ornamental in parrots. By contrast, we found little evidence for consistent sexual dichromatism in melanin-based colouration. Unlike passerines, yellow to red colouration was not strongly sexually dichromatic: although the area of colouration was generally larger in males, colour differences between the sexes were on average imperceptible to parrots. This is consistent with the idea that the prominent yellow to red sexual dichromatism in passerines is related to the use of carotenoid pigments, rather than resulting from sensory bias for these colours.

Cutaneous complications related to permanent decorative tattooing

Decorative tattooing involves the introduction of exogenous pigments and/or dyes into the dermis to produce a permanent design. Practiced for thousands of years, it has gained tremendous popularity during the past 20 years, especially among the young. Tattoo-associated cutaneous complications have only been reported since the end of the 19th Century. With the increased prevalence of tattooed individuals, dermatologists have witnessed increasing numbers of patients presenting with complaints about their tattoos. Complications primarily include infections, hypersensitivity reaction to tattoo pigments, benign and sometimes malignant tumors arising on tattoos, and the localization of various dermatoses to tattoos.

Longitudinal Melanonychia

Ungual melanoma is the most serious disease affecting the nail. The majority start with a longitudinal brown streak in the nail. To outline the different nail pigmentations, their differential diagnoses, treatment, and prognosis. Clinical and histologic evaluation of dark nail pigmentations. Brown to black nail pigmentation may be due to different coloring substances of exogenous and endogenous origin. Exogenous pigmentations usually are not streaky or do not present as a stripe of even width with regular borders. Bacterial pigmentation, most commonly due to Pseudomonas aeruginosa or Proteus spp., have a greenish or grayish hue and the discoloration is often confined to the lateral edge of the nail. Subungual hematoma may result from a single heavy trauma or repeated microtrauma which often escapes notice. The latter is usually found on the medial aspect of the great toe. Although oval in shape, it commonly does not form a neat streak. Melanin pigmentation in the form of a longitudinal streak in the nail is due to a pigment-producing focus of melanocytes in the matrix. Neither the color intensity nor the age of the patient are proof of benignity or malignancy although subungual melanomas are very rare in children and malignant longitudinal melanonychia is usually wider than 5 mm. Hutchinson's melanotic whitlow, nail dystrophy, and a bleeding mass strongly suggest malignancy. Treatment is as conservative as possible in order to keep the tip of the digit; once the melanoma is completely removed, amputations have not been shown to prolong the disease-free survival time.

Keratoacanthoma occurring within the red dye of a tattoo

Keratoacanthoma (KA) is a common keratinizing squamous cell neoplasm of unknown origin characterized by rapid growth and spontaneous involution. Trauma-induced forms have been observed with various types of skin injury. To our knowledge, reports of KA arising at tattoo sites are scarce in the literature. A 41-year-old woman with no medical history presented for a rapidly growing nodule confined to the red part of a tattoo located on the scapula. Histology showed a keratin-filled cuplike crater with an epithelial proliferation (hyperkeratosis, parakeratosis, no keratinocyte atypia). An inflammatory infiltrate in the dermis composed of lymphocytes and histiocytes intermixed with red ink-related exogenous pigments was noted. Lack of papillomatosis and viral inclusions ruled out the diagnosis of viral wart, absence of granulomatous reaction ruled out deep fungal or mycobacterial infection and lack of cytological atypia and frank architectural abnormalities did not favour a squamous cell carcinoma. KA should be included in the list of cutaneous complications related to tattooing. Diagnosis can be challenging as differential diagnoses include pseudoepitheliomatous hyperplasia and squamous cell carcinoma. Removal of the entire area, thorough histological examination and careful follow up are mandatory.

Théorie des lasers et des lampes

Lasers emit a coherent and monochromatic light beam, whereas pulsed lights produce a polychromatic light whose bandwidth is selected by adapted filters. The skin's chromophores are made up of water, hemoglobin, and melanin, to which must be added the exogenous pigments of tattoos. Each chromophore has its specific absorption spectrum. Lasers’main mechanisms of action are the photothermal effect and the photomechanical effect.

Tattoos: dermatological complications

From the Eskimo in Greenland to the tribes in Polynesia­the whole world knows the art of tattoo. Despite their wide popularity the relation between the skin diseases and the tattooed pictures aren't studied in depth. With the appearance of professional tattoo studios, the risk of infectious complications was reduced. Simultaneously, on a global scale there has been an increase in pseudolymphoma and allergic reactions caused by the introduction of an exogenous pigment into the dermis. The results of our clinical and therapeutic research and review of literature on the subject outline the major problems related to tattoos, i.e. clinical complications. The summarized data showed infectious diseases transmitted through the process of tattooing and many allergic reactions, granulomas and tumors as complications of a tattoo.

Colorimetric Characterization for Comparative Analysis of Fungal Pigments and Natural Food Colorants

Exogenous pigments produced by ascomycetous filamentous fungi belonging to the genera Penicillium, Epicoccum, and Monascus, preselected based on chemotaxonomic knowledge, have been extracted and characterized by quantitative colorimetry. The color characteristics of the fungal extracts were compared to water soluble natural colorants derived from sources currently in use. The tested fungal extracts also included some commercially available Monascus colorants. The a values for the fungal extracts were found to be both positive and negative, the b values were found to be positive, while the hue angles of the fungal color extracts ranged from 40 to 110 indicating the color distribution of fungal extracts over the red-orange-yellow region of the CIELAB color space. The fungal extracts exhibited additional color hues in the red spectrum and similar hues in the yellow spectrum as compared to the reference natural colorants. They were also found to be similar or brighter in terms of chroma to some of the reference natural colorants. Principal component analysis was performed to group and distinguish different colors based on the a and b values. The fungal color extracts could be grouped in accordance with the similarity or difference in the color to those of the existing natural colorants. The diversity of colors was not only found among different fungal genera and/or species but also within the same species on changing the media. There was a marked change in the color composition of the extracts resulting in relatively different hues. Our results, thus, indicate that there exists pigment-producing genera of ascomycetous fungi other than Monascus that produce color shades in the red and the yellow spectra in addition or similar to reference colorants. These color shades could add to the color palette of the natural colorants currently in use. In addition, the multivariate approach in distinguishing and classifying the colorants was shown to be a very useful tool in colorimetric comparison of colorants.

Update on laser treatment of tattoos

Tattoos have been in existence since the origin of humanity. They are composed of exogenous pigment of various chemical composition introduced into the dermis. In the past, many various methods of tattoo removal have been used, including chemical peeling, mechanical abrasion and various methods of surgical excisions etc. On the other hand, lasers are the treatment of choice for tattoo pigment removal. Today Q-switched lasers have been used for more than 10 years with a pulse duration in the nanosecond (10–9s) range, and have proven their efficacy in tattoo removal. Despite this, caution must be taken as some colours may resist more than others. We must also be careful with laser parameters to avoid any type of hypopigmentation or scarring. Finally, we should be aware of the potential complications related to the specific use of Q-switched lasers, the most frequent one being darkening of flesh colour pigment.

銃剣破折片の長期迷入によるオトガイ部嚢胞状異物肉芽腫の１例

A case of cystic foreign body granuloma in the mantal region caused by inclusion of metal fragments of a sword for 60 years is reported. A 76-year-old man was referred because of a painless swelling in the mental region. Radiological examination suggested a cystic lesion containing foreign bodies. Enucleation of the lesion was performed. The foreign bodies were metal fragments of a sword, found floating in the cystic fluid in the lumen. Histopathologically, the formation of a cyst without an epithelial lining was recognized. The cyst wall was composed of granulation or fibrous connective tissue with hyalinization, many foamy and multinucleated giant cells, and dark brown exogenous pigmentation. The histopathological diagnosis was a foreign body granuloma with cyst formation.

Pigmented lesions of the oral cavity

In the oral cavity, endogenous and exogenous pigment deposits reflecting a variety of systemic and local processes may be found. In addition, both benign and malignant lesions can be seen. This article presents the differential diagnosis of and a management approach to pigmentary findings in the oral cavity.

Laser treatment of pigmented lesions and tattoos.

Benign pigmented lesions and tattoos are often very responsive to laser treatment. The chromophore in most cases is melanin, although other endogenous and exogenous pigments can be targeted. The chromophore and its distribution in the skin, as well as the underlying biological processes, all help determine the best laser, if any, for a given pigmented lesion. Epidermal lesions respond well to shorter wavelengths (up to 755 nm), whereas for deeper lesions, 694 nm or longer are typically used. The 1,064-nm Nd:YAG laser is best for treating darker skinned individuals. Multicolored tattoos may need several wavelengths to best target individual ink colors.

Laser-assisted hair removal: Side effects of Q-switched Nd:YAG, long-pulsed ruby, and alexandrite lasers

Background: Laser-assisted hair removal has become popularized using wavelengths in both the red and infrared regions of the electromagnetic spectrum. These photoepilation devices target follicular melanin or an exogenous pigment placed within the follicle resulting in thermal damage to the hair follicle and shaft. However, melanocytes and keratinocytes located within the superficial layers of the skin also absorb red and infrared laser radiation. This may result in unwanted epidermal injury during the hair removal process. Objective: The purpose of this study was to examine a large patient population to determine the frequency of side effects using 3 different hair removal laser systems with various wavelengths, pulse durations, and treatment protocols. Methods: A retrospective chart review and digital photographic analysis of the side effects resulting from 900 consecutive laser-assisted hair removal treatments delivered over a 24-month study period, by means of either a Q-switched Nd:YAG laser with pretreatment wax-epilation and topical carbon solution, a long-pulse ruby laser with a contact cooling tip, or a long-pulse alexandrite laser are reported. Results: Treatment pain, erythema, edema, hypopigmentation and hyperpigmentation, blistering, crusting, erosions, purpura, and folliculitis were observed. The majority of undesirable tissue effects occurred on tanned skin or in Fitzpatrick skin phototypes III and higher. The ruby and alexandrite laser systems resulted in the majority of side effects seen. The effects of seasonal variations, anatomic treatment location, and sun exposure were striking within the ruby and alexandrite laser groups. No infections, scarring, or long-term complications occurred. Conclusion: Laser-assisted hair removal is a safe procedure when patient characteristics such as skin type, anatomic location, and sun-exposed or tanned skin are considered during selection of laser treatment parameters. Lasers emitting wavelengths with high melanin absorption capabilities should be used in a conservative manner when treating patients with dark skin phototypes or suntans. No long-term complications, infections, or scarring occurred in this study population. (J Am Acad Dermatol 1999;41:165-71.)