Owing to the growing need for natural materials in different fields, studying melanin production from biological sources is imperative. In the current study, the extracellular melanin pigment was produced by the fungus Curvularia soli AS21 ON076460. The factors that affect the production of melanin were optimized by the Plackett-Burman design (P-BD). The effect of gamma irradiation on melanin productivity was investigated. The maximum melanin yield (3.376 mg/L) was elicited by a stimulus of gamma irradiation at 1.0 kGy. The results evoked that, Curvularia soli AS21 ON076460 melanin exhibited excellent antimicrobial activity against all tested bacteria and fungi. Klebsiella pneumoniae ATCC 13883 and P. digitatum were mostly affected by melanin registering the inhibition zone diameters of 37.51 ± 0.012 and 44.25 ± 0.214 mm, respectively. Moreover, Curvularia soli AS21 ON076460 melanin indicated a significant antiviral efficacy (77% inhibition) of Herpes simplex virus (HSV1). The melanin pigment showed antioxidant activities with IC50 of 42 ± 0.021 and 17 ± 0.02 µg/mL against DPPH and NO, respectively. Melanin had cytotoxic action against human breast cancer and skin cancer cell lines (Mcf7and A431) as well as exerting a low percentage of cell death against normal skin cell lines (Hfb4). Melanin was effective in wound management of human skin cells by 63.04 ± 1.83% compared with control (68.67 ± 1.10%). The novelty in the study is attributed to the possibility of using gamma rays as a safe method in small economic doses to stimulate melanin production from the fungi that have been isolated. In summary, melanin produced from fungi has significant biological activities that encourage its usage as a supportive medical route.

Only one case of melanoma arising from melanin-producing medullary thyroid carcinoma (MTC) has been reported previously. In the present study, a second such case was reported and compared with the previous one. The patient was an 86-year-old male who presented with a right anterior neck mass. Ultrasound revealed a nodule measuring 49x48x40 mm in the right lobe of the thyroid. The levels of serum calcitonin (2,298 pg/ml) and carcinoembryonic antigen (CEA; 27.0 ng/ml) were markedly elevated. Aspiration cytology revealed suspected malignant anaplastic thyroid carcinoma and total thyroidectomy without neck nodal dissection was performed. On gross observation, the nodule was well encapsulated, soft, solid and black. Light microscopy indicated that the nodule was composed mainly of large, occasionally huge, pleomorphic cells with a solid or alveolar growth pattern. On immunohistochemistry, these cells were positive for melan-A and S-100 protein, and negative for thyroid transcription factor 1, calcitonin, chromogranin A and CEA. In the subcapsular area, melanin-producing MTC was intimately intermingled with the pleomorphic cells. No primary site of the melanoma was detectable in other organs. At three years after surgery, the patient died due to metastasis of the melanoma to the brain. The previously reported case had no detectable recurrence or distant metastasis up to 11 years after surgery. In comparison with that case, the present case had a similar morphology but the outcome was poorer. Thus, the prognosis of melanoma that transforms from MTC appears to remain uncertain.

Fungal melanins have been considered as potential biosorbents due to their metal-binding properties, stability, and scalability. Previous studies established scalable fungal melanin production methods with promising strains, however, their applicability for metal-contaminated effluents treatment has not been sufficiently reported. Herein, melanin pigment derived from Amorphotheca resinae was produced and characterized using microscopy and spectroscopy techniques. Adsorptive properties towards Cu(II), Pb(II), Cd(II), and Zn(II) were evaluated using batch tests. Melanin pigment was composed of aggregates of nanosized particles with indole-based constituents. Adsorption capacities increased with the pH of solution, especially at pH > 4.0. Maximum binding capacities of Cu(II), Pb(II), Cd(II), and Zn(II) on melanin were 69.18, 103.23, 24.31, and 13.57 mg/g, respectively. The competitive adsorption experiments elucidated affinity as Cu(II)>Pb(II)≫Cd(II)>Zn(II). Adsorption time generally required <2.5 h to reach equilibrium; the pseudo-second-order kinetic model well described the kinetics. Chelating ability of free radicals in pigment was considered as a possible mechanism for adsorption. Initial adsorption capacities remained almost intact even after 5 consecutive adsorption-desorption cycles. Complete removal of Cu(II), Pb(II), and Cd(II) from metal-contaminated effluent was confirmed. Consequently, melanin pigment derived from A. resinae can be used as a biosorbent suitable for the treatment of metal-contaminated aqueous solutions.

OBJECTIVE: This study proposes a technique for visualizing the effect of facial massage using stereo-image correlation with melanin pigment.
METHODS: In this method, the melanin pigment of a subject\'s face is made visible by using an ultraviolet light and utilized as a random pattern for stereo-image correlation. Stereo-pair images of the face with the melanin pigment before and after facial massage are recorded using a desk-sized measurement equipment. Then, the deformation of the face by the massage can be obtained based on the principle of stereovision. The effectiveness of the proposed method is demonstrated by applying it to the massage effect evaluation of eight subjects (females in their 40s).
RESULTS: The results show that the massage effect can be visualized from the displacement and strain distributions across the face obtained by the proposed method. In addition, it is observed that the face is displaced significantly by the massage and individual differences between the subjects can be captured.
CONCLUSIONS: The proposed method is effective for evaluating the effect of a facial massage when the painted pattern disappears due to the applied cream during the massage.

This case demonstrated the importance of recognition of melanin pigments in pleural effusion as a diagnostic tool for metastasis of malignant melanoma.

Cancer cells have unique nanomechanical properties, i.e., they behave as if they were elastic. This property of cancer cells is believed to be one of the main reasons for their facilitated ability to spread and metastasize. Thus, the so-called nanomechanical phenotype of cancer cells is viewed as an important indicator of the cells\' metastatic behavior. One of the most highly metastatic cancer cells are melanoma cells, which have a very unusual property: they can synthesize the pigment melanin in large amounts, becoming heavily pigmented. So far, the role of melanin in melanoma remains unclear, particularly the impact of the pigment on metastatic behavior of melanoma cells. Importantly, until recently the potential mechanical role of melanin in melanoma metastasis was completely ignored. In this work, we examined melanoma cells isolated from hamster tumors containing endogenous melanin pigment. Applying an array of advanced microscopy and spectroscopy techniques, we determined that melanin is the dominating factor responsible for the mechanical properties of melanoma cells. Our results indicate that the nanomechanical phenotype of melanoma cells may be a reliable marker of the cells\' metastatic behavior and point to the important mechanical role of melanin in the process of metastasis of melanoma.

Pigmented epithelioid melanocytoma (PEM) is a tumor encompassing epithelioid blue nevus of Carney complex (EBN of CNC) and was previously termed animal-type melanoma. Histologically PEMs are heavily pigmented spindled and epithelioid dermal melanocytic tumors with infiltrative borders, however, their origin remains unclear. Stem cells for the epidermis and hair follicle are located in the bulge area of the hair follicle with the potential to differentiate into multiple lineages. Multiple cutaneous carcinomas, including follicular cutaneous squamous cell carcinoma (FSCC), are thought to arise from stem cells in the follicular bulge. We present two cases of PEM/ATM in a 63 year-old male on the scalp with follicular origin and a 72 year-old female on the upper back arising in an intradermal nevus. Biopsy of both cases revealed a proliferation of heavily pigmented dermal nests of melanocytes with atypia. The Case 1 tumor was in continuation with the outer root sheath of the hair follicle in the bulge region. Case 2 arose in an intradermal melanocytic nevus. Rare mitotic figures, including atypical mitotic figures, were identified in both cases. We present two cases of PEM, with histologic evidence suggesting two origins: one from the follicular bulb and one from an intradermal nevus.

Pullulan is a polymer produced by Aureobasidium pullulans and the main bottleneck for its industrial production is the presence of melanin pigment. In this study, light-emitting diodes (LEDs) of different wavelengths were used to assist the fermentation process aiming to produce low-melanin containing pullulan by wild strain of A. pullulans LB83 with different carbon sources. Under white light using glucose-based medium, 11.75g.L-1 of pullulan with high melanin content (45.70UA540nm.g-1) was obtained, this production improved in process assisted by blue LED light, that resulted in 15.77g.L-1 of pullulan with reduced content of melanin (4.46UA540nm.g-1). By using sugarcane bagasse (SCB) hydrolysate as carbon source, similar concentration of pullulan (about 20g.L-1) was achieved using white and blue LED lights, with lower melanin contents in last. Use of LED light was found as a promising approach to assist biotechnological process for low-melanin containing pullulan production.

We describe a unique case of pleomorphic xanthoastrocytoma (PXA) in a 19-year-old male presenting with the chief complaint of seizures. On radiology, the tumor was located in the temporal lobe. It was cortically based and solid cystic in nature. Light microscopy showed pleomorphic large polygonal cells with inclusions, nuclear clustering, lipidization, and foamy cytoplasm intermingled with spindle cells arranged in sweeping pattern and focally containing cytoplasmic brownish black pigment. The pigment stained black with Fontana-Masson stain and bleached with potassium permanganate. Gomori silver stain showed reticulin fibers surrounding individual tumor cells as well as groups of cells. On immunohistochemistry, tumor cells were positive for GFAP, S-100 and focally for synaptophysin and CD34 but negative for HMB-45. CD34 revealed a specific membranous pattern around individual cells as well as groups of cells along the fibers replicating a reticulin pattern. The ultrastructural examination showed supporting melanosomes, thus confirming the melanin pigment. Sequencing for BRAF V600E showed a heterozygous mutation. To our knowledge only five cases of PXA with melanin pigment have been reported and none of which described BRAF V600E mutation analysis. This case provides further insight into the origin and pathogenesis of pigmented astrocytic tumor, additionally highlighting the characteristic CD34 staining pattern.

BACKGROUND: We report a case of malignant melanoma arising in medullary thyroid carcinoma that has not yet been described.
METHODS: A 66-year-old woman presented with a mass in her thyroid. The resected mass was black in color, and was composed of a mixture of classic medullary thyroid carcinoma and pleomorphic atypical cells containing melanin pigments. The pleomorphic atypical cells were morphologically consistent with malignant melanoma, and expressed Melan-A, HMB-45, and S-100 protein as determined by immunohistochemistry. Some of these cells were also positive for calcitonin and chromogranin A. Although the malignant melanoma metastasized to the lymph nodes, the patient remained free from local recurrence and distant metastasis and the primary malignant melanoma lesion was not identified for up to 11 years after the thyroidectomy.
CONCLUSIONS: 11 melanin-producing MTC cases have been reported to date. In the reported cases, the term \"malignant melanoma\" was not used, likely because the melanin-containing carcinoma cells were not morphologically consistent with malignant melanoma, but with medullary carcinoma.
CONCLUSIONS: Malignant melanoma arising in MTC may have a favorable prognosis.