The VPS33B-binding protein VPS16B is required in megakaryocyte and platelet α-granule biogenesis.

Patients with platelet α or dense δ-granule defects have bleeding problems. Although several proteins are known to be required for δ-granule development, less is known about α-granule biogenesis. Our previous work showed that the BEACH protein NBEAL2 and the Sec1/Munc18 protein VPS33B are required for α-granule biogenesis. Using a yeast two-hybrid screen, mass spectrometry, coimmunoprecipitation, and bioinformatics studies, we identified VPS16B as a VPS33B-binding protein. Immunoblotting confirmed VPS16B expression in various human tissues and cells including megakaryocytes and platelets, and also in megakaryocytic Dami cells. Characterization of platelets from a patient with arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome containing mutations in C14orf133 encoding VPS16B revealed pale-appearing platelets in blood films and electron microscopy revealed a complete absence of α-granules, whereas δ-granules were observed. Soluble and membrane-bound α-granule proteins were reduced or undetectable, suggesting that both releasable and membrane-bound α-granule constituents were absent. Immunofluorescence microscopy of Dami cells stably expressing GFP-VPS16B revealed that similar to VPS33B, GFP-VPS16B colocalized with markers of the trans-Golgi network, late endosomes and α-granules. We conclude that VPS16B, similar to its binding partner VPS33B, is essential for megakaryocyte and platelet α-granule biogenesis.

Persistent post-galactogram intraductal iodinated contrast detected on contrast-enhanced mammography (CEM) in a patient with nipple discharge.

Nipple discharge is a common complaint among adult women and is often evaluated by galactography. Contrast-enhanced mammography (CEM) is an emerging breast imaging modality that is useful in the evaluation of patients with nipple discharge who have a negative galactogram, especially if they are not good candidates for contrast-enhanced MRI. Here we present a case of a 37-year-old female who was 22 weeks pregnant and presented with suspicious nipple discharge. The patient initially underwent galactography, which was negative, and was subsequently referred for CEM for further evaluation. One week after the galactogram, the patient underwent CEM which revealed persistent intraductal iodinated contrast from the galactogram. The retained intraductal contrast obscured the area of concern on the CEM and limited evaluation for underlying areas of enhancement. Given the increasing popularity of CEM in breast imaging practice and its utility in the evaluation of patients with nipple discharge, recognition of retained intraductal contrast as a source of artifact on CEM is important so that steps can be taken to prevent acquiring a limited and/or non-diagnostic CEM. We suggest several practical steps the radiologist can take when planning the diagnostic workup of patients with nipple discharge to ensure the patient will be able to successfully undergo CEM, if needed. These steps will help reduce unnecessary patient exposure to radiation and intravenous contrast and avoid a delay in diagnosis and treatment.

TeleResidents: Exploring the use of Resident Home Workstations During the COVID Pandemic.

RATIONALE AND OBJECTIVES: Since the beginning of the COVID-19 pandemic, numerous strategies have been proposed to allow for continued resident education while following social distancing guidelines. Diagnostic radiology is largely electronic work, allowing for relatively easy transition to telehealth. Our institution deployed home workstations to interested upper level radiology residents and fellows in order to maintain high volume workload and education, while complying with CDC social distancing and quarantine guidelines. MATERIALS AND METHODS: We deployed 28 home workstations with integrated PACS, electronic health record, and reporting system, supporting workflow that matched our on-site processes and allowing residents to work from home while on diagnostic rotations. Two months into the pilot, surveys were sent to trainees and faculty to assess satisfaction related to education, productivity, and wellness. A retrospective study count was performed for a sample of residents in order to assess productivity. RESULTS: Residents perceived their remote productivity as unchanged or better than at the hospital, while faculty were more likely to perceive it as decreased, however, objective results showed no difference. Education was largely considered worse or unchanged with very few regarding it as improved. Those utilizing shared-screen signout platforms rated education better than those utilizing voice/telephone communications only. Trainees expressed improvement in wellness and quality of life. CONCLUSION: Home workstations for trainees represent a feasible solution for implementing social distancing or even quarantine while maintaining operational productivity. There is the added benefit of scheduling flexibility, option to overcome space constraints, and improved quality of life.