Isolated esophageal IgG4-related disease presenting with progressive dysphagia and weight loss in a middle-aged man.

Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized immune-mediated condition that results in inflammation, stricturing and mass formation. It causes a wide spectrum of disease and clinical presentations depending on the organ system involved. Isolated esophageal IgG4-RD is rare and diagnosis can be difficult. It is highly responsive to corticosteroids, and early identification and instigation of management is key.We describe the case of a 47-year-old man who presented with a food bolus obstruction on a background of progressive dysphagia and weight loss. Imaging and gastroscopy demonstrated diffuse esophageal thickening with a benign appearing stricture. Following non-specific histologic findings on biopsy and a non-diagnostic endoscopic ultrasound guided fine needle aspiration, he underwent video-assisted thoracoscopic surgery with esophageal core biopsy. This confirmed the diagnosis of IgG4-RD. Initial treatment was with corticosteroids. However, due to recurrence of symptoms upon weaning of corticosteroids, azathioprine maintenance therapy was instituted. Azathioprine has previously been used in systemic cases of IgG4-RD but has not been reported for isolated esophageal disease.This case highlights the difficulties in the diagnosis and treatment of esophageal IgG4-RD and the need to consider it as a differential diagnosis when histology reveals esophagitis with lymphoplasmacytic infiltration.

Strong suppression of heat conduction in a laboratory replica of galaxy-cluster turbulent plasmas.

In conventional gases and plasmas, it is known that heat fluxes are proportional to temperature gradients, with collisions between particles mediating energy flow from hotter to colder regions and the coefficient of thermal conduction given by Spitzer's theory. However, this theory breaks down in magnetized, turbulent, weakly collisional plasmas, although modifications are difficult to predict from first principles due to the complex, multiscale nature of the problem. Understanding heat transport is important in astrophysical plasmas such as those in galaxy clusters, where observed temperature profiles are explicable only in the presence of a strong suppression of heat conduction compared to Spitzer's theory. To address this problem, we have created a replica of such a system in a laser laboratory experiment. Our data show a reduction of heat transport by two orders of magnitude or more, leading to large temperature variations on small spatial scales (as is seen in cluster plasmas).

The effects of dummy/pacifier use on infant blood pressure and autonomic activity during sleep.

BACKGROUND: Dummy/pacifier use is protective for sudden infant death syndrome (SIDS); however, the mechanism/s for this are unknown. As impaired cardiovascular control may be the underlying cause of SIDS, we assessed the effects of dummy/pacifier use on cardiovascular control during sleep within the first 6 months of life. METHODS: Term infants, divided into dummy/pacifier users and non-dummy/pacifier users, were studied at 2-4 weeks (n = 27), 2-3 months (n = 35) and 5-6 months (n = 31) using daytime polysomnography. Heart rate, blood pressure (BP), heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) were measured in triplicate 1-2-min epochs during quiet and active sleep in the supine and prone positions. RESULTS: Overall, during the non-sucking periods, in the prone position, the BP was higher (10-22 mmHg) in dummy/pacifier users compared to non-users at 2-4 weeks and 5-6 months (p < 0.05 for both). HRV and BRS were higher in dummy/pacifier users compared to non-users at 2-4 weeks (p < 0.05). Active sucking increased HRV and BPV, consistent with increased sympathetic activity in dummy/pacifier users. CONCLUSIONS: Higher BP and HRV in dummy/pacifier users indicate increased sympathetic tone, which may serve as a protective mechanism against possible hypotension leading to SIDS; however, these effects were not apparent at 2-3 months, when the risk of SIDS is highest.