Sarcomeres are the basic contractile units of cardiac myocytes. Recent studies demonstrated remodeling of sarcomeric proteins in several diseases, including genetic defects and heart failure. Here we investigated remodeling of sarcomeric α-actinin in two models of heart failure, synchronous (SHF) and dyssynchronous heart failure (DHF), as well as a model of cardiac resynchronization therapy (CRT). We applied three-dimensional confocal microscopy and quantitative methods of image analysis to study isolated cells from our animal models. 3D Fourier analysis revealed a decrease of the spatial regularity of the α-actinin distribution in both SHF and DHF versus control cells. The spatial regularity of α-actinin in DHF cells was reduced when compared with SHF cells. The spatial regularity of α-actinin was partially restored after CRT. We found longitudinal depositions of α-actinin in SHF, DHF and CRT cells. These depositions spanned adjacent Z-disks and exhibited a lower density of α-actinin than in the Z-disk. Differences in the occurrence of depositions between the SHF, CRT and DHF models versus control were significant. Also, CRT cells exhibited a higher occurrence of depositions versus SHF, but not DHF cells. Other sarcomeric proteins did not accumulate in the depositions to the same extent as α-actinin. We did not find differences in the expression of α-actinin protein and its encoding gene in our animal models. In summary, our studies indicate that HF is associated with two different types of remodeling of α-actinin and only one of those was reversed after CRT. We suggest that these results can guide us to an understanding of remodeling of structures and function associated with sarcomeres.

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The authors conducted a case series to assess accuracy of DIAGNOdent (DD) in assessment of activity of dental caries lesions in root surfaces and in furcations and at crown margins. The study was a prospective, single center case series. The patients were 123 adults (age ≥ 55 years). To be included, a patient needed to have at least one active root caries lesion. The study was conducted at the Roseman College of Dental Medicine in South Jordan, Utah, USA and at area nursing homes. Lesions were rinsed and dried with air, and DD readings were obtained. Lesions were then isolated and 38% silver diamine fluoride was applied repeatedly for two minutes with a microbrush. DD readings and treatments were repeated every six months. Mean DD values were significantly different between active (unarrested) and inactive (arrested) caries for all comparisons, p-value < 0.0001. The optimal cut-off values for DD were between 20 and 35 except optimal cut-offs were higher for furcation and crown margin surfaces, particularly in the posterior (optimal cut-offs 40–45). This study demonstrates DD is a potentially valuable tool for assessing lesion activity in root surfaces, at restoration margins, and in furcations.

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