Objective: To investigate clinical and pathologic aspects of IgG4‐related disease (IgG4‐RD) in non‐Asian populations.Methods: We conducted a retrospective review of the medical records of patients with IgG4‐RD who presented to an academic medical center from January 1994 to September 2012.Results: Among 166 patients identified, the median age at diagnosis was 61 years (interquartile range [IQR] 49–70 years), 75% were male, and 80% were white. The median number of organs involved was 2 (IQR 2–3). When organs were grouped according to anatomic system, the hepatopancreaticobiliary system was most commonly involved (77%). The median highest serum IgG4 level during the clinical course was 215 mg/dl (IQR 122–466). Forty‐three patients (26%) had a normal serum IgG4 level. Seventy‐nine pathology specimens were available for immunostaining. The median number of IgG4+ cells was 37 (IQR 25–82) per high‐power field, with an IgG4+:IgG+ ratio of 0.50 (IQR 0.32–0.68). Among 151 patients who received medical therapy, 72 (48%) received steroid‐sparing agents because of relapse, recurrence, or corticosteroid intolerance. Of the 66 patients who were newly diagnosed, started on corticosteroid monotherapy as the initial treatment, and followed up at our institution, 30 (45%) experienced relapse or recurrence despite an initial favorable response. The number of organs involved had a significant impact on time to relapse or recurrence, with a hazard ratio of 1.48 (95% confidence interval [95% CI] 1.12–1.93) (P < 0.01) in multivariate analysis. The standardized incidence ratio of malignancy was 4.5 (95% CI 1.5–7.5).Conclusion. IgG4‐RD is a multisystem disorder that commonly affects older men and has a propensity for relapse, recurrence, and malignancy.

Conventionally, ultrasonographic assessment of diaphragm contractility has involved measuring respiratory changes in diaphragm thickness (thickening fraction) using B-mode or caudal displacement with M-mode. Two-dimensional speckle-tracking has been increasingly used to assess muscle deformation (‘strain’) in echocardiography. We sought to determine in a pilot study if this technology could be utilized to analyze diaphragmatic contraction. Fifty healthy adult volunteers with normal exercise capacity underwent ultrasound imaging. A linear array transducer was used for the assessment of diaphragm thickness, thickening fraction (TF), and strain in the right anterior axillary line at approximately the ninth intercostal space. A phased array transducer was applied subcostally for the assessment of diaphragm displacement on the right mid-clavicular line. Diaphragmatic images were recorded from the end of expiration through the end of inspiration at 60 % maximal inspiratory capacity. Diaphragm strain was analyzed off-line by speckle tracking imaging. Blinded inter- and intra-rater variability was tested in 10 cases. Mean right diaphragm thickness at end-expiration (±SD: standard deviation) was 0.24 cm (±0.1), with TF of 45.1 % (±12) at 60 % peak inspiratory effort. Mean right diaphragm caudal displacement was 4.9 cm (±1). Mean right diaphragm strain was -40.3 % (±9). A moderate correlation was seen between longitudinal strain and TF (R2 0.44, p < 0.0001). A weak correlation was seen between strain and caudal displacement (R2 0.14, p < 0.01), and an even weaker correlation was seen between caudal displacement and TF (R2 0.1, p = 0.04). Age, gender, and body mass index were not significantly associated with right diaphragm strain or TF. Although inter- and intra-rater variability was overall good for TF, caudal displacement, and strain (inter-rater R2; 0.8, 0.9, and 0.7, respectively [p < 0.01], intra-rater R2; 0.9, 0.7, and 0.9, respectively [p < 0.01]), strain values did have a slightly lower inter-rater repeatability. Diaphragmatic strain estimated by speckle tracking imaging was associated with conventional ultrasound measures of diaphragmatic function (TF and caudal displacement). Further clinical studies are warranted to investigate its clinical utility.

We observed the dynamic three-dimensional (3D) single molecule behaviour of acetylcholine-binding protein (AChBP) and nicotinic acetylcholine receptor (nAChR) using a single molecule tracking technique, diffracted X-ray tracking (DXT) with atomic scale and 100 μs time resolution. We found that the combined tilting and twisting motions of the proteins were enhanced upon acetylcholine (ACh) binding. We present the internal motion maps of AChBP and nAChR in the presence of either ACh or α-bungarotoxin (αBtx), with views from two rotational axes. Our findings indicate that specific motion patterns represented as biaxial angular motion maps are associated with channel function in real time and on an atomic scale.