Deep MR Brain Image Super-Resolution Using Spatio-Structural Priors

High resolution Magnetic Resonance (MR) images are desired for accurate diagnostics. In practice, image resolution is restricted by factors like hardware and processing constraints. Recently, deep learning methods have been shown to produce compelling state-of-the-art results for image enhancement/super-resolution. Paying particular attention to desired hi-resolution MR image structure, we propose a new regularized network that exploits image priors, namely a low-rank structure and a sharpness prior to enhance deep MR image super-resolution (SR). Our contributions are then incorporating these priors in an analytically tractable fashion \color{black} as well as towards a novel prior guided network architecture that accomplishes the super-resolution task. This is particularly challenging for the low rank prior since the rank is not a differentiable function of the image matrix(and hence the network parameters), an issue we address by pursuing differentiable approximations of the rank. Sharpness is emphasized by the variance of the Laplacian which we show can be implemented by a fixed feedback layer at the output of the network. As a key extension, we modify the fixed feedback (Laplacian) layer by learning a new set of training data driven filters that are optimized for enhanced sharpness. Experiments performed on publicly available MR brain image databases and comparisons against existing state-of-the-art methods show that the proposed prior guided network offers significant practical gains in terms of improved SNR/image quality measures. Because our priors are on output images, the proposed method is versatile and can be combined with a wide variety of existing network architectures to further enhance their performance.Comment: Accepted to IEEE transactions on Image Processin

Short-term impact of aged garlic extract on endothelial function in diabetes: A randomized, double-blind, placebo-controlled trial.

Impaired endothelial function portends an increased risk of cardiovascular disease. Vascular oxidative stress and systemic inflammation play a critical role in the pathogenesis and progression of vascular disease. Aged garlic extract (AGE) may improve impaired vascular endothelial function, while decreasing the progression of atherosclerotic plaque. We hypothesized that AGE may improve endothelial function, and in this study, we examined this hypothesis to determine whether this can be achieved over a period of 3 months, measured by the cardio-ankle vascular index (CAVI), by reducing intracellular oxidant stress and stimulating nitric oxide generation in endothelial cells. We conducted a double-blinded placebo controlled, randomized clinical trial to investigate the effects of AGE on CAVI in subjects with type 2 diabetes mellitus. A total of 65 individuals (38 men and 27 women) with a mean age of 58.8±11.1 years were enrolled and randomized to the AGE or placebo group in a double-blind placebo controlled trial. An ANOVA model with treatment as the main effect was used to compare changes in CAVI from baseline to follow-up between groups. The primary objective of this study was reduction in CAVI over a 3-month period. In the AGE group, CAVI was reduced on average by 0.71±1.27 vs. a mean reduction of 0.13±0.94 in the placebo group (P=0.04). On the whole, this study demonstrates that AGE has a positive impact on endothelial function in patients with T2DM and may play a role in the primary prevention of cardiovascular disease

MiR203 Mediates Subversion of Stem Cell Properties During Mammary Epithelial Differentiation via Repression of ΔNP63α and Promotes Mesenchymal-to-Epithelial Transition

During reproductive life, the mammary epithelium undergoes consecutive cycles of proliferation, differentiation and apoptosis. Doing so relies on the retained proliferative capacity, prolonged lifespan and developmental potency of mammary stem cells (MaSCs). ΔNp63α, the predominant TP63 isoform in mammary epithelia, is robustly expressed in MaSCs and is required for preservation of self-renewing capacity in diverse epithelial structures. However, the mechanism(s) underlying subversion of this activity during forfeiture of self-renewing capacity are poorly understood. MicroRNAs (miRNAs) govern critical cellular functions including stem cell maintenance, development, cell cycle regulation and differentiation by disrupting translation of target mRNAs. Data presented here indicate that expression of miR203, a miRNA that targets ΔNp63α and ΔNp63β is activated during luminal epithelial differentiation and that this pattern is observed in the murine mammary hierarchy. In addition, we present evidence that the transcription factor Zeb1 represses miR203 expression, thus enhancing ΔNp63α protein levels. Furthermore, ectopic miR203 suppresses ΔNp63α expression, proliferation and colony formation. The anti-clonogenic effects mediated by miR203 require suppression of ΔNp63α. In addition, ectopic miR203 promotes mesenchymal-to-epithelial transition and disrupts activities associated with epithelial stem cells. These studies support a model in which induction of miR203 mediates forfeiture of self-renewing capacity via suppression of ΔNp63α and may also have anti-tumorigenic activity through its reduction of EMT and cancer stem cell populations

Aged garlic extract reduces low attenuation plaque in coronary arteries of patients with diabetes: A randomized, double-blind, placebo-controlled study.

Several previous studies have demonstrated that aged garlic extract (AGE) inhibits the progression of coronary artery calcification and non-calcified plaque (NCP) in the general population. However, its effects on plaque progression in patients with diabetes have not yet been investigated, at least to the best of our knowledge. This study investigated whether AGE reduces the coronary plaque volume measured by cardiac computed tomography angiography (CCTA) in patients with diabetes mellitus (DM). A total of 80 participants with DM with a median age of 57 years were prospectively assigned to consume 2,400 mg AGE/day (after completion, 37 participants) or placebo (after completion, 29 participants) orally. Both groups underwent CCTA at baseline and follow-up 365 days apart. In total, 66 participants completed the study. Coronary plaque volume, including total plaque (TP), dense calcium (DC), fibrous, fibro-fatty and low-attenuation plaque (LAP) volumes were measured based upon pre-defined intensity cut-off values using semi-automated software (QAngio CT). Changes in various plaque types were normalized to the total coronary artery length. The non-parametric Wilcoxon rank-sum test was performed to examine the differences in plaque formation between the 2 groups. No significant differences were found in the baseline characteristics between the AGE and placebo groups. Compared with the placebo group, the AGE group exhibited a statistically significant regression in normalized LAP [median and standard deviation (SD) -0.2 (18.8) vs. 2.5 (69.3), P=0.0415]. No differences were observed in TP, fibrous, or fibrofatty plaque volumes between the AGE and placebo group. On the whole, this study indicated that the %LAP change in the AGE group was significantly greater than that in the placebo group in patients with diabetes. However, further studies are warranted to evaluate whether AGE has the ability to stabilize vulnerable plaque and decrease adverse cardiovascular events

Novel Non-invasive Fractional Flow Reserve from Coronary CT Angiography to Determine Ischemic Coronary Stenosis

Coronary artery disease (CAD) patients may have an obstructive disease on invasive coronary angiography, but few of these patients have had flow-limiting obstructive disease diagnosed on invasive fractional flow reserve (FFR). FFR is infrequently performed because of its cost- and time-effectiveness. Advancement in non-invasive imaging has enabled FFR to be derived non-invasively using coronary CT angiography (CCTA), without the need for induction of hyperemia or modification of the standard CCTA acquisition protocol. FFR derived from CCTA (FFRCT) has been shown to have excellent correlation with invasive FFR, and remains an effective diagnostic tool in the presence of reduced signal-to-noise ratio, coronary calcification and motion artifact. The utility of FFRCT has also helped to deepen our understanding of hemodynamically significant CAD. Hence, there is now interest in exploring the possible interplay between these mechanistic forces and their effect on the development of coronary plaque and the vulnerability of these plaques

Increased urinary nitrite, a marker of nitric oxide, in active inflammatory bowel disease.

BACKGROUND: Nitric oxide (NO) production is increased in inflammatory bowel disease (IBD), and measurement of NO metabolites may be useful for monitoring disease activity. AIMS AND OBJECTIVES: To characterise urinary nitrite levels, a stable metabolite of NO, in IBD and to evaluate its potential as a marker of disease activity. METHODS: Twelve-hour urinary nitrites were measured by the microplate assay method in 46 patients with IBD (active; n = 32). Urinary samples from 16 healthy individuals served as controls. RESULTS: Increased levels of urinary nitrites were found in patients with active IBD compared with those with inactive IBD. Twenty-eight out of 32 patients (87.5%) with active IBD had detectable levels of nitrite in their urine as compared with 2/14 (14.3%) patients with inactive IBD. None of the 16 healthy controls had detectable urinary nitrite. Twelve-hour urinary nitrite in active compared with inactive IBD: 5 0.7 versus 0.1+/-0.04 micromol (P < 0.05). There was good correlation between urinary nitrite and some markers of disease activity in IBD such as C-reactive protein and microalbuminuria but not with erythrocyte sedimentation rate. Conclusions: Increased levels of nitrite were detected in urine of patients with active IBD, consistent with increased NO synthesis. This simple assay may be exploited as a potential marker of disease activity in IBD

Single Nanoparticle Plasmonic Spectroscopy for Study of the Efflux Function of Multidrug ABC Membrance Transporters of Single Live Cells

ATP-binding cassette (ABC) membrane transporters exist in all living organisms and play key roles in a wide range of cellular and physiological functions. The ABC transporters can selectively extrude a wide variety of structurally and functionally unrelated substrates, leading to multidrug resistance. Despite extensive study, their efflux molecular mechanisms remain elusive. In this study, we synthesized and characterized purified silver nanoparticles (Ag NPs) (97 ± 13 nm in diameter), and used them as photostable optical imaging probes to study efflux kinetics of ABC membrane transporters (BmrA) of single live cells (B. subtilis). The NPs with concentrations up to 3.7 pM were stable (non-aggregated) in a PBS buffer and biocompatible with the cells. We found a high dependence of accumulation of the intracellular NPs in single live cells (WT, Ct-BmrAEGFP, ΔBmrA) upon the cellular expression level of BmrA and NP concentration (0.93, 1.85 and 3.7 pM), showing the highest accumulation of intracellular NPs in ΔBmrA (deletion of BmrA) and the lowest ones in Ct-BmrA-EGFP (over-expression of BmrA). Interestingly, the accumulation of intracellular NPs in ΔBmrA increases nearly proportionally with the NP concentration, while those in WT and Ct-BmrA-EGFP do not. This result suggests that the NPs enter the cells via passive diffusion driven by concentration gradients across the cellular membrane and they are extruded out of cells by BmrA transporters, similar to conventional pump substrates (antibiotics). This study shows that such large substrates (84-100 nm NPs) can enter into the live cells and be extruded out of the cells by BmrA, and the NPs can serve as nm-sized optical imaging probes to study the size-dependent efflux kinetics of membrane transporters in single live cells in real time

A primer to common major gastrointestinal post-surgical anatomy on CT—a pictorial review

The post-operative abdomen can be challenging and knowledge of normal post-operative anatomy is important for diagnosing complications. The aim of this pictorial essay is to describe a few selected common, major gastrointestinal surgeries, their clinical indications and depict their normal post-operative computed tomography (CT) appearance. This essay provides some clues to identify the surgeries, which can be helpful especially when surgical history is lacking: recognition of the organ(s) involved, determination of what was resected and familiarity with the type of anastomoses used

Concept for Predicting Vibrations in Machine Tools Using Machine Learning

Vibrations have a significant influence on quality and costs in metal cutting processes. Existing methods for predicting vibrations in machine tools enable an informed choice of process settings, however they rely on costly equipment and specialised staff. Therefore, this contribution proposes to reduce the modelling effort required by using machine learning based on data gathered during production. The approach relies on two sub-models, representing the machine structure and machining process respectively. A method is proposed for initialising and updating the models in production