Cardiac MR imaging of nonischemic cardiomyopathies: imaging protocols and spectra of appearances

Recent technologic advances in cardiac magnetic resonance (MR) imaging have resulted in images with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MR is a valuable imaging technique for detection and assessment of the morphology and functional characteristics of the nonischemic cardiomyopathy. It has gained acceptance as a standalone imaging modality that can provide further information beyond the capabilities of traditional modalities such as echocardiography and angiography. Black-blood fast spin-echo MR images allow morphologic assessment of the heart with high spatial resolution, while T2-weighted MR images can depict acute myocardial edema. Contrast material-enhanced images can depict and be used to quantify myocardial edema, infiltration, and fibrosis. This review presents recommended cardiac MR protocols for and the spectrum of imaging appearances of the nonischemic cardiomyopathies.     

Targeting hepatic kisspeptin receptor ameliorates nonalcoholic fatty liver disease in a mouse model

Nonalcoholic fatty liver disease (NAFLD), the most common liver disease, has become a silent worldwide pandemic. The incidence of NAFLD correlates with the rise in obesity, type 2 diabetes, and metabolic syndrome. A hallmark featureof NAFLD is excessive hepatic fat accumulation or steatosis, due to dysregulated hepatic fat metabolism, which can progress to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Currently, there are no approved pharmacotherapies to treat this disease. Here, we have found that activation of the kisspeptin 1 receptor (KISS1R) signaling pathway has therapeutic effects in NAFLD. Using high-fat diet–fed mice, we demonstrated that a deletion of hepatic Kiss1r exacerbated hepatic steatosis. In contrast, enhanced stimulation of KISS1R protected against steatosis in wild-type C57BL/6J mice and decreased fibrosis using a diet-induced mouse model of NASH. Mechanistically, we found that hepatic KISS1R signaling activates the master energy regulator, AMPK, to thereby decrease lipogenesis and progression to NASH. In patients with NAFLD and in high-fat diet–fed mice, hepatic KISS1/KISS1R expression and plasma kisspeptin levels were elevated, suggesting a compensatory mechanism to reduce triglyceride synthesis. These findings establish KISS1R as a therapeutic target to treat NASH.     

Appropriateness and utilization of cardiac CT: Implications for development of future criteria

Background  

The cardiac CT (CCT) appropriateness criteria (AC) were jointly published by multiple societies to ensure effective utilization of CCT. We sought to determine how these criteria apply to CCT scans performed at a tertiary-care hospital.     

Cardiac valve disease: spectrum of findings on cardiac 64-MDCT

OBJECTIVE: Recent studies have established that cardiac MDCT generates high-quality images of the cardiac valves. Images are acquired during a single breath-hold (inspiration) after the injection of iodinated contrast material (5 mL/s) followed by a saline bolus chaser. Incremental data sets are then reconstructed throughout the R-R interval, and after transfer to a workstation, specialized software combines data sets sequentially to generate cine loops of the heart throughout the cardiac cycle. The purpose of this article is to describe the cardiac MDCT techniques allowing optimal cardiac valve depiction and to illustrate the MDCT appearances of the most important valve diseases. CONCLUSION: Cardiac MDCT provides an excellent imaging method for illustrating cardiac valve disease. Radiologists should be aware of the various appearances of the common and most important cardiac valve diseases on cardiac MDCT.     

Mid- and long-term results of the joint preserving therapy of hallux rigidus

Background  

The hallux rigidus is an over 100-year-known pathology. Yet an overall accepted therapy regime does not exist. The aim of this prospective study was to analyze the long-term clinical outcome and patient satisfaction of joint preserving operative care in patients with symptomatic hallux rigidus.     

Bioavailability of diazepam after intramuscular injection of its water-soluble prodrug alone or with atropine–pralidoxime in healthy volunteers

Background and purpose:

The aim of this study was to assess the relative bioavailability of diazepam after administration of diazepam itself or as a water-soluble prodrug, avizafone, in humans.

Experimental approach:

The study was conducted in an open, randomized, single-dose, three-way, cross-over design. Each subject received intramuscular injections of avizafone (20 mg), diazepam (11.3 mg) or avizafone (20 mg) combined with atropine (2 mg) and pralidoxime (350 mg) using a bi-compartmental auto-injector (AIBC). Plasma concentrations of diazepam were quantified using a validated LC/MS–MS assay, and were analysed by both a non-compartmental approach and by compartmental modelling.

Key results:

The maximum concentration (C_max) of diazepam after avizafone injection was higher than that obtained after injection of diazepam itself (231 vs. 148 ng·mL⁻¹), while area under the curve (AUC) values were equal. Diazepam concentrations reached their maximal value faster after injection of avizafone. Injection of avizafone with atropine–pralidoxime (AIBC) had no effect on diazepam C_max and AUC, but the time to C_max was increased, relative to avizafone injected alone. According to the Akaike criterion, the pharmacokinetics of diazepam after injection as a prodrug was best described as a two-compartment with zero-order absorption model. When atropine and pralidoxime were injected with avizafone, the best pharmacokinetic model was a two-compartment with a first-order absorption model.

Conclusion and implications:

Diazepam had a faster entry to the general circulation and achieved higher C_max after injection of prodrug than after the parent drug. Administration of avizafone in combination with atropine and pralidoxime by AIBC had no significant effect on diazepam AUC and C_max.