No abstract

This study was conducted to evaluate effects of dietary protease (PR) on growth performance, nutrient digestibility, and intestinal morphology of weaned pigs. A total of 75 weaned pigs [7.06 ± 0.18 kg of average body weight (BW); 28 day old] were randomly allotted to 3 dietary treatments in a randomized complete block design (blocks = BW and sex): a diet based on corn and soybean meal to meet the requirement of crude protein (CP) as a positive control (PC; CP = 24.49%), a low protein diet as a negative control (NC; CP = 22.51%), and NC + 0.02% PR. The PR used in this study was a commercial product containing 75,000 protease units/g derived from Nocardiopsis prasina produced in Bacillus licheniformis. Pigs were fed the dietary treatments for 6 weeks and the diets containing 0.2% chromic oxide for the last week of this study. Blood, feces, ileal digesta, and ileum samples were collected from randomly selected two pigs in each pen on respective time points. Measurements were growth performance, apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of dry matter (DM), CP, and energy, frequency of diarrhea, packed cell volume (PCV), and ileal morphology of weaned pigs. Pigs fed PC and PR had higher (p < 0.05) final BW, average daily gain (ADG), and gain to feed ratio (G:F) during overall experimental period than those fed NC. Pigs fed PC and PR had higher (p < 0.05) AID or ATTD of DM, CP, or energy than those fed NC. Moreover, pigs fed PR had higher ratio between villus height and crypt depth (p < 0.05) and number of goblet cells (p < 0.05) than those fed NC. Addition of PR decreased (p < 0.05) frequency of diarrhea for the first two weeks after weaning compared with PC and NC. In addition, pigs fed PR had lower (p < 0.05) PCV on d 14 after weaning than those fed PC and NC. In conclusion, addition of PR in nursery diets with a low protein level significantly improved growth performance, nutrient digestibility, and intestinal morphology of weaned pigs.

Background-Limited availability of noninvasive and biologically precise diagnostic tools poses a challenge for the evaluation and management of patients with myocarditis. Methods and Results-The feasibility of cardiovascular magnetic resonance (CMR) imaging with magneto-fluorescent nanoparticles (MNPs) for detection of myocarditis and its effectiveness in discriminating inflammation grades were assessed in experimental autoimmune myocarditis (EAM) (nϭ65) and control (nϭ10) rats. After undergoing CMR, rats were administered with MNPs, followed by a second CMR 24 hours later. Head-to-head comparison of MNP-CMR with T 2 -weighted, early and late gadolinium enhancement CMR was performed in additional EAM (nϭ10) and control (nϭ5) rats. Contrast-to-noise ratios were measured and compared between groups. Flow cytometry and microscopy demonstrated that infiltrating inflammatory cells engulfed MNPs, resulting in altered myocardial T 2 * effect. Changes in contrast-to-noise ratio between pre-and post-MNP CMR were significantly greater in EAM rats (1.08Ϯ0.10 versus 0.48Ϯ0.20; PϽ0.001). In addition, contrast-to-noise ratio measurement in MNP-CMR clearly detected the extent of inflammation (PϽ0.001) except for mild inflammation. Compared with conventional CMR, MNP-CMR provided better image contrast (CNR change 8% versus 46%, PϽ0.001) and detectability of focal myocardial inflammation. Notably, MNP-CMR successfully tracked the evolution of myocardial inflammation in the same EAM rats. Key Words: contrast media Ⅲ inflammation Ⅲ macrophage Ⅲ magnetic resonance imaging Ⅲ myocarditis M yocarditis is defined as inflammation of myocardial tissue with characteristic inflammatory cell infiltration into myocardium. 1,2 Clinically, myocarditis is a major cause of sudden death in young adults 3 and is an important underlying cause of both dilated cardiomyopathy 2 and arrhythmogenic right ventricular cardiomyopathy. 4 Despite these serious consequences, there is no single confirmatory tool to diagnose myocarditis with absolute certainty, resulting in limited consensus on clinical practice guidelines for its evaluation and treatment. 5,6 Clinical Perspective on p 2612 Conclusions-MagnetoThe introduction of endomyocardial biopsy combined with immunohistochemistry (IHC) and cardiovascular magnetic resonance (CMR) imaging has helped to overcome the major drawbacks of traditional diagnostic methodologies. 7,8 Received October 23, 2011; accepted April 16, 2012. On the basis of an in vitro feasibility study of MNP-MRI for the detection of inflammation, we investigated in vivo cellular CMR of macrophage-based inflammation in EAM rats, quantified cellular distribution of MNP-positive cells depending on inflammation grade, and compared the detectability of focal inflammation area in the myocardium of EAM rats between MNP-enhanced CMR and conventional CMR (T2W, EGE, and LGE) as a diagnosis of myocarditis. Magneto-fluorescent nanoparticle-enhanced CMR was also employed to noninvasively track the evolution of inflammation in myocarditis. Methods...

A water-soluble T1 magnetic resonance imaging contrast agent (1) has been synthesized. The bimodal contrast agent 1 responds to the Cu(2+) ion in living cells by enhancing the MRI modality signal whereas the optical signal gradually drops. This dual modality probe response depends on the cellular free copper ions in RAW 264.7 cells even at the micromolar level.