Atypical Presentation of Aspergillus Mediastinitis Infection in a Heart Transplant Patient: the Importance of Combined Medical and Surgical Treatment.

Aspergillus fumigatus is an opportunistic fungus that mainly affects immunocompromised patients. Due to significant immunosuppressive therapy, patients who undergo orthotopic heart transplant have an increased risk of infection. Aspergillosis is the most common fungal infection in orthotopic heart transplant recipients (70%) and usually presents as invasive aspergillosis, which has a rapidly progressive course and is highly fatal. In heart transplant patients with invasive aspergillosis, overall mortality may range from 53% to 78%. Aspergillus mediastinitis infection is somewhat rare in orthotopic heart transplant recipients, with only 6 reported cases. Treatment may require early surgical drainage and antifungal therapy. We present the case of a 50-year-old man who developed Aspergillus mediastinitis 1 year after heart transplant surgery. This case illustrates the diagnostic challenge of an atypical presentation of Aspergillus mediastinitis and the importance of multiple drainage procedures in refractory disease, combined with long-term antifungal therapy.

Conical diffraction illumination opens the way for low phototoxicity super-resolution imaging.

We present a new technology for super-resolution fluorescence imaging, based on conical diffraction. Conical diffraction is a linear, singular phenomenon, taking place when a laser beam is diffracted through a biaxial crystal. We use conical diffraction in a thin biaxial crystal to generate illumination patterns that are more compact than the classical Gaussian beam, and use them to generate a super-resolution imaging modality. While there already exist several super-resolution modalities, our technology (biaxial super-resolution: BSR) is distinguished by the unique combination of several performance features. Using BSR super-resolution data are achieved using low light illumination significantly less than required for classical confocal imaging, which makes BSR ideal for live-cell, long-term time-lapse super-resolution imaging. Furthermore, no specific sample preparation is required, and any fluorophore can be used. Perhaps most exciting, improved resolution BSR-imaging resolution enhancement can be achieved with any type of objective no matter the magnification, numerical aperture, working distance, or the absence or presence of immersion medium. In this article, we present the first implementation of BSR modality on a commercial confocal microscope. We acquire and analyze validation data, showing high quality super-resolved images of biological objects, and demonstrate the wide applicability of the technology. We report live-cell super-resolution imaging over a long period, and show that the light dose required for super-resolution imaging is far below the threshold likely to generate phototoxicity.