Vi capsular polysaccharide (Vi) was first identified as a virulence antigen of Salmonella typhi, the causative agent of typhoid fever in humans; it renders S. typhi resistant to phagocytosis and the action of serum complement. However, the role of Vi during the infection of intestinal epithelium with S. typhi is not completely understood. We show here that Vi can interact with a model human intestinal epithelial cell line, Caco-2, through a cell-surfaceassociated molecular complex containing two major proteins of 30 and 35 kDa and a minor protein of Ϸ68 kDa. The two major proteins were identified as the putative tumor suppressor molecule, prohibitin, and its closely related homolog, B cell receptor-associated protein 37. These two proteins were enriched in lipid rafts, and Vi readily associated with these membrane microdomains. Engagement of Caco-2 cells with Vi inhibited their ability to produce an inflammatory response upon infection with Vi ؊ S. typhi. Consistent with this effect, infection of Caco-2 cells with Vi ؉ S. typhi produced less IL-8 compared with Vi ؊ S. typhi. Cells treated with Vi showed reduced extracellular signal-regulated kinase phosphorylation in response to infection with Vi ؊ S. typhi or stimulation with phorbol 12-myristate 13-acetate, suggesting that the mitogen-activated protein kinase pathway might be a target for Vi-mediated inhibition of inflammatory responses. These findings reveal a crucial role for Vi in the modulation of early inflammatory responses during infection with S. typhi. This kind of a modulation could play a significant role in the establishment of infection by S. typhi.Vi capsular polysaccharide ͉ putative tumor suppressor molecule ͉ IL-8

Wegener granulomatosis is an uncommon necrotizing vasculitis that classically manifests as a clinical triad consisting of upper and lower airway involvement and glomerulonephritis. Other less frequently involved organ systems include the central and peripheral nervous system and large joints. The diagnosis is based on a combination of clinical and laboratory findings. Because thoracic involvement often predominates, chest radiographic findings are often the first to suggest the diagnosis. However, chest computed tomography (CT) has superior sensitivity and specificity for evaluation of the airways, lung parenchyma, and mediastinum, particularly with the use of multiplanar reformatted and three-dimensional images. Common pulmonary radiologic findings include waxing and waning nodules, masses, ground-glass opacities, and consolidation. Airway involvement is usually characterized by circumferential tracheobronchial thickening, which can be smooth or nodular. Pleural effusions are the most common manifestation of pleural disease and can result from primary involvement or be secondary to renal failure. Mediastinal lymphadenopathy is a nonspecific finding and is usually reactive. Uncommon thoracic radiologic manifestations include involvement of the heart and great vessels. CT is the imaging modality of choice for diagnosis, surveillance, and follow-up in patients with Wegener granulomatosis.

FDG PET/CT has high specificity in the detection of pulmonary lymphangitic carcinomatosis. Focal pulmonary lymphangitic carcinomatosis close to a primary malignant tumor, however, can be missed at PET.

Central venous catheters are being increasingly used as hemodialysis vascular access. We evaluated catheter survival, outcome predictors, and complications in a total of 36 catheters used in 13 children and young adults undergoing chronic maintenance hemodialysis through catheter for a duration of 10.4+/-5.6 months. Reasons for catheter failure were: thrombosis 12 of 36 (33%), infection 6 of 36 (17%), and extrusion 2 of 36 (5.4%). Catheters were lost to infection and thrombosis at 1.1 and 2.2 episodes per 1,000 catheter days, respectively. Symptomatic infections, Gram-negative and polymicrobial sepsis increased the risk of catheter failure. Most of the thrombotic episodes occurred in patients with inherent thrombotic tendency. The survival of the 36 catheters was 62% at 1 year. The survival of 13 randomly chosen catheters, 1 from each patient, was 85% at 1 year. The time from insertion to first complication correlated significantly with the outcome (P<0.03). We conclude that central venous catheters are still associated with a high rate of failure and may be a regular access choice only in a selected patient population with no inherent thrombotic tendency and no other option available for long-term hemodialysis.