Background: Occ channels mediate small molecule uptake in Pseudomonads. Results: We have analyzed a number of site-directed mutants for two Occ channels. Conclusion: Pores of OccD subfamily members are highly flexible. The central basic ladder residues interact with the substrate carboxyl group and are essential for transport. Significance: The data provide the first atomistic insights into transport by an important class of OM channels.

Tracheobronchial amyloidosis, manifested by amyloid deposits limited specifically to tracheal and bronchial tissue, is a rare manifestation with only a few hundred published cases. Patients classically present with symptoms related to fixed upper airway obstruction caused by tracheal stenosis. Clinical symptoms are non-specific and include hoarseness, dyspnea, cough, stridor, hemoptysis, and dysphagia, which are similar to those caused by more common airway disorders, often leading to incorrect, missed, and delayed diagnosis. The wide-spread use of computerized tomography (CT) imaging has the potential of dramatically advancing the early diagnosis of tracheobronchial amyloidosis. We present a case of a patient with chronic and progressive hoarseness, diagnosed with tracheobronchial amyloidosis, with a focus on unusually clear and precise CT soft tissue neck imaging. CT imaging demonstrated nodular circumferential raised mass-like thickening involving the long-segment posterior wall of the distal trachea. The wall thickening also extended into the proximal left main stem bronchi, but spared the distal bronchial tree. This resulted in moderate (approximately 50%) narrowing of the tracheal lumen, which explained the patient's hoarseness. Routine CT imaging of patients with chronic and progressive respiratory symptoms, including cough, hoarseness, and dyspnea, is recommended. Tracheobronchial amyloidosis is an uncommon disease, but it may become more commonly recognized with broader use of more effective CT imaging protocols.

Granulomatosis with polyangiitis formerly known as Wegener's granulomatosis was first described by German pathologist Friedrich Wegener in 1936. It is a multi-system necrotizing noncaseating granulomatous vasculitis which affects small to medium-sized vessels. It can involve any organ system, most commonly the lungs and kidneys. American College of Rheumatology requires 2 of 4 criteria for diagnosis: Positive biopsy for granulomatous vasculitis, urinary sediment with red blood cells, abnormal chest radiograph and oral/nasal inflammation. Here we present a case of Granulomatosis with polyangiitis with brief review of literature.

Intracavitary cardiac thrombi, uncommonly found in the right chambers, have been shown to form secondary to endocardial and myocardial diseases. The differential diagnosis for an intracavitary cardiac mass is broad, including primary cardiac tumors, cardiac metastases, anatomic variants, vegetations, and thrombi. Here we present a unique case with a large calcified intracavitary cardiac thrombus in a 26-year-old woman with obesity, immune thrombocytopenic purpura, and a new diagnosis of systemic lupus erythematosus. Initial imaging presentation in this case masqueraded as a tumor, delaying the true diagnosis. A combination of cardiac imaging techniques, including transthoracic and transesophageal echocardiograms, cardiac CT, and cardiac MRI were required to correctly diagnose this calcified bland thrombus.

No abstract