A Novel Method using Long Axis Cardiac MRI Measurements can Improve in vivo Myocardial Infarct Quantification

PurposeCurrently, the American Heart Association (AHA) 17-segment model is the preferred clinical method to define and quantify left ventricle (LV) myocardial infarction (MI) size. This method is subjective and can be inaccurate given that segmental approximation assumes a specific percent of infarcted tissue when compared to reference standard post-mortem histopathology. To improve the accuracy and reproducibility of infarct volume quantification we propose a novel measurement technique based on cardiac MRI images from a porcine model of myocardial infarction. Data were collected from serial MRI exams of Yucatan mini swine over 6 months and endpoint organ harvesting for histopathologic analysis. MethodsTwo observers evaluated four infarct sizing methods: myocardial contouring of post-mortem heart slices, contouring using cardiac MRI, AHA 17-segment model analysis and novel long-axis MRI infarct sizing. ResultsLV infarct sizes ranges were 1.6% - 25.8% (n=10) using reference standard histopathologic infarct sizing. Intraclass correlations (ICC) were calculated between two observers and averaged due to high similarity, ICC > .900. A t-test of .0006 and Bland-Altman plots show statistically significant differences in 17-segment model infarct size compared to histopathologic analysis while no significant difference was found when compared to our new novel method with 0.8198. Linear correlation showed an R 2 of 0.9111 between MRI contoured infarct size and our novel MRI infarct sizing model to predict infarct size as a percentage while the R 2 of the 17-Seg model is 0.8197. ConclusionsThe 17-sgement model provides an inferior quantitative assessment of LV infarct size compared to the proposed long-axis infarct sizing suggesting it maybe a robust and easily implementable quantitative assessment of LV infarct size in advanced imaging.

Cinnamaldehyde Induces Release of Cholecystokinin and Glucagon-Like Peptide 1 by Interacting with Transient Receptor Potential Ankyrin 1 in a Porcine Ex-Vivo Intestinal Segment Model

Cinnamaldehyde and capsaicin have been reported to exert effects on the gastric function, mediated by the interaction with transient receptor potential ankyrin channel 1 (TRPA1) and transient receptor potential vanilloid channel 1 (TRPV1), respectively. This study examined whether these compounds could trigger the release of cholecystokinin (CCK) and/or glucagon-like peptide 1 (GLP-1) in the pig’s gut in a porcine ex-vivo intestinal segment model. Furthermore, it was verified whether this response was mediated by TRPA1 or TRPV1 by using the channel’s antagonist. These gut peptides play a key role in the “intestinal brake", a feedback mechanism that influences the function of proximal parts of the gut. Structural analogues of cinnamaldehyde were screened as well, to explore structure-dependent activation. Results showed a significant effect of capsaicin on GLP-1 release in the proximal small intestine, TRPV1 independent. TRPA1 showed to be strongly activated by cinnamaldehyde, both in proximal and distal small intestine, evidenced by the release of CCK and GLP-1, respectively. Out of all structural derivates, cinnamaldehyde showed the highest affinity for TRPA1, which elucidates the importance of the α,β-unsaturated aldehyde moiety. In conclusion, cinnamaldehyde as a TRPA1 agonist, is a promising candidate to modulate gastric function, by activating intestinal brake mechanisms.

Functional Contributions of the Arcuate Fasciculus to Language Processing

Current evidence strongly suggests that the arcuate fasciculus (AF) is critical for language, from spontaneous speech and word retrieval to repetition and comprehension abilities. However, to further pinpoint its unique and differential role in language, its anatomy needs to be explored in greater detail and its contribution to language processing beyond that of known cortical language areas must be established. We address this in a comprehensive evaluation of the specific functional role of the AF in a well-characterized cohort of individuals with chronic aphasia (n = 33) following left hemisphere stroke. To evaluate macro- and microstructural integrity of the AF, tractography based on the constrained spherical deconvolution model was performed. The AF in the left and right hemispheres were then manually reconstructed using a modified 3-segment model (Catani et al., 2005), and a modified 2-segment model (Glasser and Rilling, 2008). The normalized volume and a measure of microstructural integrity of the long and the posterior segments of the AF were significantly correlated with language indices while controlling for gender and lesion volume. Specific contributions of AF segments to language while accounting for the role of specific cortical language areas – inferior frontal, inferior parietal, and posterior temporal – were tested using multiple regression analyses. Involvement of the following tract segments in the left hemisphere in language processing beyond the contribution of cortical areas was demonstrated: the long segment of the AF contributed to naming abilities; anterior segment – to fluency and naming; the posterior segment – to comprehension. The results highlight the important contributions of the AF fiber pathways to language impairments beyond that of known cortical language areas. At the same time, no clear role of the right hemisphere AF tracts in language processing could be ascertained. In sum, our findings lend support to the broader role of the left AF in language processing, with particular emphasis on comprehension and naming, and point to the posterior segment of this tract as being most crucial for supporting residual language abilities.

Sympathetic innervation pattern in NICM patients with ventricular tachycardia -anteroseptal versus inferolateral substrates-

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation - Projektnummer 447558597) Background Among patients with non-ischemic cardiomyopathy (NICM) two dominant ventricular tachycardia (VT) substrate locations, namely anteroseptal (AS) and inferolateral (IL), have been identified. The poor outcome after catheter ablation of AS substrates (ASS) compared to IL substrates (ILS) has been attributed to its deep intramural location. However, region specific tissue charateristics, including sympathetic innervation, as important determinant of arrhythmogeneity, may also contribute to the outcome disparity. Aim To evaluate the association between regional sympathetic denervation, myocardial fibrosis and VT substrates according to two dominant VT substrate locations. Methods Twenty-nine patients from the ‘Leiden Nonischemic Cardiomyopathy Study’, who underwent electroanatomical substrate mapping and radiofrequency catheter ablation (RFCA), LGE-CMR and 123-I-MIBG imaging between 2011-2018 were included. The 16-segment model was used to describe the distribution of endocardial low unipolar voltage (UV <25th IQR) (=electroanatomical surrogate for fibrosis), the location of abnormal local electrograms and VT related sites (= surrogate for VT substrate) and the presence of LGE. Regional cardiac sympathetic innervation was determined by 123-I-MIBG imaging and analyzed according to the 16-segment model. Regions with sympathetic denervation were correlated with low UV areas, VT substrate location and LGE. Patients were categorized according to the dominant VT substrate location in ASS or ILS. Results Ten patients had a dominant ASS, 12 patients a dominant ILS and 1 patient had ASS and ILS; 6 patients had other VT substrate locations. All but one patient with ASS and one with ILS also showed corresponding low UV (=surrogate for fibrosis) in segments with VT substrates. Eight patients with IL VT substrates but only 4 with AS substrates showed corresponding LGE in the VT related segments. All patients with inferolateral VT substrates showed sympathetic denervation in IL segments (100% matching segments), but only 3/11 (27%) with anteroseptal substrates had sympathetic denervation in AS segments (P = 0.0002). UV was not significantly different between matching (VT substrate and denervation) and not matching ASS segments (5.74 ± 2.69 mV vs. 4.64 ± 1.85 mV, P = 0.78) and between matching ASS and ILS segments (5.74 ± 2.69 mV vs. 7.61 ± 2.91, P = 0.43). LGE location was matching with sympathetic denervation in all patients with ILS but only in 33% of patients with ASS. Conclusion Despite low endocardial UV (=surrogate for fibrosis) for AS and IL segments harboring VT substrates, regional sympathetic denervation coincided with fibrosis only for IL VT substrates. The mismatch between regional fibrosis and preserved innervation for AS VT substrates may contribute to a VT substrate difficult to control by RFCA.

Extra Large Sequence Transformer Model for Chinese Word Segment

Chinese word segment is widely studied in document analysis. The accuracy of the current popular word segment model, LSTM+CRF, is still not satisfactory. Models trained by the popular dataset often fails in the out-domain situation. In this paper, combining the Transformer-XL layer, the Fully-Connect layer, and the Conditional Random Field layer, the proposed model improved 3.23% in the macro-F1 score, comparing to the BERT+CRF model, on the MSR2005 Chinese word segment test dataset.