Elemental sulphur and alkali elutable melanin detected in oral melanosis and malignant melanoma by energy‐filtering transmission electron microscopy

Nagai, Noriyuki; Lee, You Jin; Nagaoka, Noriyuki; Gündüz, Mehmet; Nakano, Keisuke; Nojima, Tsuyoshi; Tsujigiwa, Hidetsugu; Gündüz, Esra; Siar, Chong Huat; Nagatsuka, Hitoshi

doi:10.1034/j.1600-0714.2002.00010.x

Cited by 9 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…50 Their size range overlaps that found for melanosomes in humans. 51,52 The scatterers' size is comparable to the wavelengths in the UV-visible region ͑330 to 900͒ and a few times smaller than the wavelengths in the NIR ͑900 to 1700 nm͒. Given that the probe geometry used in ESS is sensitive to both scattering and absorption, this suggests that the change in scattering properties of the melanosomes and/or melanin ͑and/or other subcellular changes͒ has a stronger effect on the shape of the spectrum ͑for the shorter wavelengths͒ than the chromophore content in pigmented melanomas.…”

Section: Resultsmentioning

confidence: 99%

Comparison between ultraviolet-visible and near-infrared elastic scattering spectroscopy of chemically induced melanomas in an animal model

A’Amar

Ley²,

Bigio

2004

J. Biomed. Opt.

View full text Add to dashboard Cite

The work reported compares elastic scattering spectroscopy (ESS) for diagnosis of pigmented skin lesions in two spectral regions: UV-visible and near infrared (NIR). Given the known strong absorption by melanin in the near-UV to mid-visible range of the spectrum, such a comparison can help determine the optimum wavelength range of ESS for diagnosis of pigmented skin lesions. For this purpose, four South American opossums are treated with dimethylbenz(a)anthracene on multiple dorsal sites to induce both malignant melanomas and benign pigmented lesions. Skin lesions are examined in vivo with ESS using both UV-visible and NIR, with wavelength ranges of 330 to 900 nm and 900 to 1700 nm, respectively. Both portable systems use the same fiber optic probe geometry. ESS measurements are made on the lesions, and spectral differences are grouped by diagnosis from standard histopathological procedure. Both ESS datasets show strong spectral trends with the histopathological assignments, and the data suggest a model for the underlying basis of the spectral distinction between benign and malignant pigmented nevi.

show abstract

Section: Resultsmentioning

confidence: 99%

Comparison between ultraviolet-visible and near-infrared elastic scattering spectroscopy of chemically induced melanomas in an animal model

A’Amar

Ley²,

Bigio

2004

J. Biomed. Opt.

View full text Add to dashboard Cite

show abstract

“…Extracted melanins have been extensively studied using a wide variety of techniques, such as high performance liquid chromatography ͑HPLC͒, 25 electron microscopy, 26 and spectrophotometric methods. 27,28 However, these methods require very complicated and lengthy preprocessing of the sample.…”

Section: Differentiating Eumelanin and Pheomelanin In Tissuementioning

confidence: 99%

Probing skin pigmentation changes with transient absorption imaging of eumelanin and pheomelanin

Ye²,

Matthews

et al. 2008

J. Biomed. Opt.

View full text Add to dashboard Cite

As some of the most ubiquitous and biologically important natural pigments, melanins play essential roles in the photoprotection of skin. Changes in melanin production could potentially be useful for clinical diagnosis of the progression stage of melanoma. Previously we demonstrated a new method for imaging melanin distribution in tissue with two-color transient absorption microscopy. Here we extend this study to longer wavelengths and show that we are able to image melanin in fixed thin skin slices with higher signal-to-noise ratios (SNRs) and demonstrate epimode imaging. We show that both photothermal effects and long-lived excited states can contribute to the long-lived signal. Eumelanin and pheomelanin exhibit markedly different long-lived excited state absorption. This difference should enable us to map out their respective distribution in tissue samples with subcellular resolution. This technique could provide valuable information in diagnosing the malignant transformation of melanocytes.

show abstract

“…Tissue samples containing small regions of BM in selected specimens from light microscopic sections were microdissected out, postfixed in 2.5% glutaraldehyde, and postfixed further in a solution of 1% OsO 4 [18]. These were dehydrated and embedded according to the standard procedure, and thin sections were cut and stained with uranyl acetate-lead citrate and examined with an EF LEO912 transmission electron microscope.…”

Section: Transmission Electron Microscopymentioning

confidence: 99%

Differential expression of basement membrane collagen-IV α1 to α6 chains during oral carcinogenesis

et al. 2006

Self Cite

View full text Add to dashboard Cite

This study aimed to resolve if basement membrane (BM) collagen alpha chains undergo remodeling during oral carcinogenesis. Using immunohistochemistry and transmission electron microscopy, we found that BMs in oral epithelial dysplasias (OED: mild, n=10; moderate, n=10; severe, n=10) and carcinoma in situ (CIS) (n=10) differed from normal mucosa (n=6) and oral epithelial hyperplasia (n=5) in showing: (1) excessive lamina densa-like material ultrastructurally, and (2) stronger immunoexpression for alpha5(IV) than for alpha1(IV), alpha2(IV), and alpha6(IV) chains-findings that implicate these molecules' role as an adhesive template for the attachment and persistence of basal dysplastic cells. Incipient loss of BM integrity in CIS, where alpha5(IV)/alpha6(IV) chains were more frequently absent than alpha1(IV)/alpha2(IV) chains, suggests that alpha(IV) network disruption is crucial for progression of dysplastic cells into the extracellular compartment, marking transition into the invasive phase. In carcinomatous BM, the disappearance of alpha(IV) chains was more severe in poorly differentiated oral squamous cell carcinoma (OSCC) (n=10) than in well-differentiated OSCC (n=10). In all samples examined, alpha3(IV) and alpha4(IV) chains were absent. These findings taken together suggest that BM collagen-IV alpha chains undergo remodeling where selective increase and loss of these molecules are probably early and late events, respectively, during progression of oral dysplasia to cancer.

show abstract

Elemental sulphur and alkali elutable melanin detected in oral melanosis and malignant melanoma by energy‐filtering transmission electron microscopy

Abstract: Our findings suggest that abnormal melanosome morphology and high sulphur content are predictive markers for assessment of early or precancerous melanotic lesions and malignant melanoma.

Cited by 9 publications

References 13 publications

Comparison between ultraviolet-visible and near-infrared elastic scattering spectroscopy of chemically induced melanomas in an animal model

Comparison between ultraviolet-visible and near-infrared elastic scattering spectroscopy of chemically induced melanomas in an animal model

Probing skin pigmentation changes with transient absorption imaging of eumelanin and pheomelanin

Differential expression of basement membrane collagen-IV α1 to α6 chains during oral carcinogenesis

Contact Info

Product

Resources

About