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Abstract  Left ventricular remodeling during the development of heart failure is a strong predictor of cardiovascular mortality. However, methods to objectively quantify remodeling-associated shape changes are not routinely available but may be possible with new computational anatomy tools. In this study, we analyzed and compared multi-detector computed tomographic (MDCT) images of ventricular shape at end-systole (ES) and end-diastole (ED) to determine whether regional structural characteristics could be identified and, as a proof of principle, whether differences in hearts of patients with anterior myocardial infarction (MI) and ischemic cardiomyopathy (ICM) could be distinguished from those with global nonischemic cardiomyopathy (NICM). MDCT images of hearts from 11 patients (5 with ICM) with ejection fractions (EF) p = 0.03) and ES (p = 0.03). For validation, a second set of 14 EF-matched patients (8 with ICM) were evaluated. The discrimination rule learned from the training data set was able to differentiate ICM from NICM patients (p = 0.008). Application of a novel shape analysis method to in vivo human cardiac images acquired on a clinical scanner is feasible and can quantify regional shape differences at end-systole in remodeled myopathic human myocardium. This approach may be useful in identifying differences in the remodeling process between ICM and NICM populations and possibly in differentiating the populations. [ABSTRACT FROM AUTHOR]

The response by individuals to nicotine is likely to reflect the interaction of this compound with target nAChRs. However, resolving how different genetic backgrounds contribute to unique mouse strain-specific responses to this compound remains an important and unresolved issue. To examine this question in detail, expression of the nicotine acetylcholine receptor (nAChR) subunits α3, α4, α5, α7, β2, and β4 was measured in the dorsal hippocampus using immunohistochemistry in mouse strains or lines BALB/c, C3H/J, C57BL/6, CBA/J, DBA/2, Long Sleep (LS), Short Sleep (SS), and CF1. The nAChRs in all mice colocalized with glutamic acid decarboxylase (GAD)-positive interneurons that were subclassified into at least four groups based on nAChR subunit heterogeneity. A notable difference between mouse strains was the expression of nAChRs by astrocyte subpopulations in CA1 subregions whose numbers vary inversely with nAChR-immunostained neurons. This novel relationship also correlated with published parameters of strain sensitivity to nicotine. Attempts to identify the origin of this significant difference in nAChR expression among strains included comparison of the entire nAChRα4 gene sequence. Although multiple polymorphisms were identified, including two that changed nAChRα4 amino acid coding, none of these clearly correlate with strain-related differences in cell type-specific nAChR expression. These findings suggest that mouse strain-specific behavioral and physiological responses to nicotine are likely to be a reflection of a complex interplay between genetic factors that shape differences in expression and cellular architecture of this modulatory neurotransmitter system in the mammalian nervous system. J. Comp. Neurol. 468:334–346, 2004. © 2003 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]