Sarcoid Granulomas and Systemic Sarcoidosis Triggered by Cosmetic Tattoos.

Cosmetic tattooing of eyebrow and lips has become very popular and is expected to be paralleled by more frequent complications. We present 4 cases of granulomas in cosmetic tattoos complicated by regional or systemic manifestations of sarcoidosis including affection of the lungs in 2 cases, the activity triggered by the tattoo. Three cases of traditional decorative tattoos on extremities serve as reference. It is noteworthy that cosmetic tattoos despite small size and thereby low relative dose of pigment injected in the skin can trigger fully developed systemic sarcoidosis. It is hypothesized that iron oxide pigments popular in cosmetic tattoo inks of red or brown color may be prone to elicit sarcoid reactions and thus carry a special risk of granuloma. In decorative tattoos, carbon black is the commonest trigger. It is emphasized that the finding of granulomas in tattoos shall be followed by search of other manifestations of sarcoidosis through patient history and diagnostic examinations to exclude pulmonary, ocular, and other organ manifestations. Patients with granulomas in tattoos shall be informed that active sarcoidosis, if not already present, can become manifest later with a latency of months or years and often with abrupt debut when the triggering tattoo may be overlooked by the doctor who is unfamiliar with this less common type of sarcoidosis.

Three-color fluorescence cross-correlation spectroscopy for analyzing complex nanoparticle mixtures.

Further insight toward the complex association and dissociation events of macromolecules requires the development of a spectroscopic technique that can track individual components, or building blocks of these macromolecules, and the complexes which they form, in real time. Three-color fluorescence cross-correlation spectroscopy (3C-FCCS) has been shown to track assemblies of three spectrally labeled species in solution. Here, we clearly show that 3C-FCCS is capable of distinguishing beads barcoded with quantum dots from free quantum dots in the background despite the 800-to-1 difference in concentration of these two components. The validation of this spectroscopic technique in combination with the development of barcode labels would enable one to start to investigate complex association and dissociation kinetics of macromolecules and nanomaterials during the assembly process.

The development of direct multicolour fluorescence cross-correlation spectroscopy: towards a new tool for tracking complex biomolecular events in real-time.

Direct three-colour fluorescence cross-correlation spectroscopy can reveal interactions between three fluorescently labelled biomolecules, giving insight toward the complex events that constitute signal transduction pathways. Here we provide the optical and theoretical basis for this technology and demonstrate its ability to detect specific biological associations between nanoparticle-labelled DNA molecules.