Melanin-based coatings as lead-binding agents.

Interactions between metal ions and different forms of melanin play significant roles in melanin biochemistry. The binding properties of natural melanin and related synthetic materials can be exploited for nonbiological applications, potentially including water purification. A method for investigating metal ion-melanin interactions on solid support is described, with lead as the initial target. 2.5 cm discs of the hydrophobic polymer PVDF were coated with synthetic eumelanin from the tyrosinase-catalyzed polymerization of L-dopa, and with melanin extracted from human hair. Lead (Pb(2+)) binding was quantified by atomic absorption spectroscopy (flame mode), and the data was well fit by the Langmuir model. Langmuir affinities ranged from 3.4 · 10(3) to 2.2 · 10(4) M(-1). At the maximum capacity observed, the synthetic eumelanin coating bound ~9% of its mass in lead. Binding of copper (Cu(2+)), zinc (Zn(2+)), and cadmium (Cd(2+)) to the synthetic-eumelanin-coated discs was also investigated. Under the conditions tested, the Langmuir affinities for Zn(2+), Cd(2+), and Cu(2+) were 35%, 53%, and 77%, respectively, of the Langmuir affinity for Pb(2+). The synthetic-eumelanin-coated discs have a slightly higher capacity for Cu(2+) on a per mole basis than for Pb(2+), and lower capacities for Cd(2+) and Zn(2+). The system described can be used to address biological questions and potentially be applied toward melanin-based water purification.

Undifferentiated Pleomorphic Sarcoma after Pirfenidone Use: A Case Report.

INTRODUCTION: Pirfenidone was approved in 2014 for the treatment of idiopathic pulmonary fibrosis. Pirfenidone inhibits several factors such as tissue growth factor-ß and platelet-derived growth factor, leading to decreased epithelial and fibroblast proliferation and collagen synthesis. The drug improves progression-free survival and is well tolerated, with minimal side effects. However, data on its long-term effects are lacking. CASE PRESENTATION: We present a rare case in which an undifferentiated pleomorphic sarcoma developed in a 59-year-old man with idiopathic pulmonary fibrosis who was treated with pirfenidone for more than a year. DISCUSSION: Undifferentiated pleomorphic sarcoma, also known as malignant fibrous histiocytoma, is a soft-tissue sarcoma arising from fibroblasts. The disease presents in the extremities and the trunk of elderly patients, and rarely in the retroperitoneum. Surgical excision is the mainstay of treatment; however, recurrence is common in the form of lung and lymph node metastases. In this report we review this rare malignancy and highlight the need for postmarketing longitudinal studies to determine additional adverse effects in patients with idiopathic pulmonary fibrosis who are on pirfenidone therapy.

Glioblastoma Multiforme in a Patient with Multiple Myeloma: A Case Report and Literature Review.

INTRODUCTION: Lenalidomide is an immunomodulatory drug approved by the US Food and Drug Administration in 2006 for the treatment of multiple myeloma. In 2012, the Food and Drug Administration issued a statement warning physicians of the increased risk with lenalidomide treatment of the following secondary primary malignancies: Acute myelogenous leukemia, myelodysplastic syndromes, and Hodgkin lymphoma. The statement did not mention glioblastoma multiforme, a Grade 4 astrocytoma, or other high-grade astrocytomas that have been reported on rare occasions in the setting of multiple myeloma. CASE PRESENTATION: A 72-year-old man, who had been in complete remission from multiple myeloma for 1 year after treatment that included lenalidomide, presented with confusion, headache, nausea and vomiting, and recurrent falls. A magnetic resonance image of his brain revealed a mass that on stereotactic biopsy was found to be glioblastoma multiforme. DISCUSSION: We present the seventh reported case of high-grade astrocytoma as a second primary malignancy in multiple myeloma and the first reported occurrence of glioblastoma multiforme after the use of lenalidomide in multiple myeloma. This report adds to the pool of cases that reveal associations between use of lenalidomide and increased risk of developing secondary primary high-grade astrocytomas in multiple myeloma.