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22. Peak wall rupture index is associated with risk of rupture of abdominal aortic aneurysms, independent of size and sex.

Author

Siika, Antti, Talvitie, Mareia, Liljeqvist, Moritz Lindquist, Bogdanovic, Marko, Gasser, T. Christian, Hultgren, Rebecka, and Roy, Joy

Abstract

Background: Information on the predictive determinants of abdominal aortic aneurysm rupture from CT angiography are scarce. The aim of this study was to investigate biomechanical parameters in abdominal aortic aneurysms and their association with risk of subsequent rupture. Methods: In this retrospective study, the digital radiological archive was searched for 363 patients with ruptured abdominal aortic aneurysms. All patients who underwent at least one CT angiography examination before aneurysm rupture were included. CT angiography results were analysed to determine maximum aneurysm diameter, aneurysm volume, and biomechanical parameters (peak wall stress and peak wall rupture index). In the primary survival analysis, patients with abdominal aortic aneurysms less than 70 mm were considered. Sensitivity analyses including control patients and abdominal aortic aneurysms of all sizes were performed. Results: A total of 67 patients who underwent 109 CT angiography examinations before aneurysm rupture were identified. The majority were men (47, 70%) and the median age at the time of CTA examination was 77 (71–83) years. The median maximum aneurysm diameter was 56 (interquartile range 46–65) mm and the median time to rupture was 2.13 (interquartile range 0.64–4.72) years. In univariable analysis, maximum aneurysm diameter, aneurysm volume, peak wall stress, and peak wall rupture index were all associated with risk of rupture. Women had an increased HR for rupture when adjusted for maximum aneurysm diameter or aneurysm volume (HR 2.16, 95% c.i. 1.23 to 3.78 (P = 0.007) and HR 1.92, 95% c.i. 1.06 to 3.50 (P = 0.033) respectively). In multivariable analysis, the peak wall rupture index was associated with risk of rupture. The HR for peak wall rupture index was 1.05 (95% c.i. 1.03 to 1.08) per % (P < 0.001) when adjusted for maximum aneurysm diameter and 1.05 (95% c.i. 1.02 to 1.08) per % (P < 0.001) when adjusted for aneurysm volume. Conclusion: Biomechanical factors appear to be important in the prediction of abdominal aortic aneurysm rupture. Women are at increased risk of rupture when adjustments are made for maximum aneurysm diameter alone. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Genetic Complexity and Parkinson's Disease

Author

Scott, William K., Stajich, Jeffrey M., Yamaoka, Larry H., Speer, Marcy C., Vance, Jeffery M., Roses, Allen D., Pericak-Vance, Margaret A., Gasser, T., Müller-Myhsok, B., Wszolek, Z. K., Dürr, A., Vaughan, J. R., Bonifati, V., Meco, G., Bereznai, B., Oehlmann, R., Agid, Y., Brice, A., Wood, N., and Polymeropoulos, Michael H.

Published
1997

36. Three-dimensional growth and biomechanical risk progression of abdominal aortic aneurysms under serial computed tomography assessment.

Author

Siika, Antti, Bogdanovic, Marko, Liljeqvist, Moritz Lindquist, Gasser, T. Christian, Hultgren, Rebecka, and Roy, Joy

Subjects
ABDOMINAL aortic aneurysms, THROMBOSIS
Abstract

Growth of abdominal aortic aneurysms (AAAs) is often described as erratic and discontinuous. This study aimed at describing growth patterns of AAAs with respect to maximal aneurysm diameter (Dmax) and aneurysm volume, and to characterize changes in the intraluminal thrombus (ILT) and biomechanical indices as AAAs grow. 384 computed tomography angiographies (CTAs) from 100 patients (mean age 70.0, standard deviation, SD = 8.5 years, 22 women), who had undergone at least three CTAs, were included. The mean follow-up was 5.2 (SD = 2.5) years. Growth of Dmax was 2.64 mm/year (SD = 1.18), volume 13.73 cm3/year (SD = 10.24) and PWS 7.3 kPa/year (SD = 4.95). For Dmax and volume, individual patients exhibited linear growth in 87% and 77% of cases. In the tertile of patients with the slowest Dmax-growth (< 2.1 mm/year), only 67% belonged to the slowest tertile for volume-growth, and 52% and 55% to the lowest tertile of PWS- and PWRI-increase, respectively. The ILT-ratio (ILT-volume/aneurysm volume) increased with time (2.6%/year, p < 0.001), but when adjusted for volume, the ILT-ratio was inversely associated with biomechanical stress. In contrast to the notion that AAAs grow in an erratic fashion most AAAs displayed continuous and linear growth. Considering only change in Dmax, however, fails to capture the biomechanical risk progression, and parameters such as volume and the ILT-ratio need to be considered. [ABSTRACT FROM AUTHOR]

Published
2023
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37. Genetic overlap between Alzheimer’s disease and Parkinson’s disease at the MAPT locus

Author

Desikan, R S, Schork, A J, Wang, Y, Witoelar, A, Sharma, M, McEvoy, L K, Holland, D, Brewer, J B, Chen, C-H, Thompson, W K, Harold, D, Williams, J, Owen, M J, O'Donovan, M C, Pericak-Vance, M A, Mayeux, R, Haines, J L, Farrer, L A, Schellenberg, G D, Heutink, P, Singleton, A B, Brice, A, Wood, N W, Hardy, J, Martinez, M, Choi, S H, DeStefano, A, Ikram, M A, Bis, J C, Smith, A, Fitzpatrick, A L, Launer, L, van Duijn, C, Seshadri, S, Ulstein, I D, Aarsland, D, Fladby, T, Djurovic, S, Hyman, B T, Snaedal, J, Stefansson, H, Stefansson, K, Gasser, T, Andreassen, O A, and Dale, A M

Published
2015
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42. Amorphous and crystalline ices studied by dielectric spectroscopy.

Author

Plaga, L. J., Raidt, A., Fuentes Landete, V., Amann-Winkel, K., Massani, B., Gasser, T. M., Gainaru, C., Loerting, T., and Böhmer, R.

Subjects
ICE crystals, DIELECTRIC measurements, ICE, GAS hydrates, DIELECTRICS, METHANE hydrates
Abstract

This work reports on frequency dependent ambient-pressure dielectric measurements of hyperquenched glassy water, ice IV, ice VI, as well as a CO2-filled clathrate hydrate, the latter featuring a chiral water network. The dipolar time scales and the spectral shapes of the loss spectra of these specimens are mapped out and compared with literature data on low-density and high-density amorphous ices as well as on amorphous solid water. There is a trend that the responses of the more highly dense amorphous ices are slightly more dynamically heterogeneous than those of the lower-density amorphous ices. Furthermore, practically all of the amorphous ices, for which broadband dielectric spectra are available, display a curved high-frequency wing. Conversely, the high-frequency flanks of the nominally pure ice crystals including ice V and ice XII can be characterized by an approximate power-law behavior. While the spectral shapes of the nominally pure ices thus yield some hints regarding their amorphicity or crystallinity, a comparison of their time scale appears less distinctive in this respect. In the accessible temperature range, the relaxation times of the crystalline ices are between those of low-density and high-density amorphous ice. Hence, with reference also to previous work, the application of suitable doping currently seems to be the best dielectric spectroscopy approach to distinguish amorphous from crystalline ices. [ABSTRACT FROM AUTHOR]

Published
2019
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43. Genetic basis of Parkinson's disease: inheritance, penetrance, and expression

Author

Schulte C and Gasser T

Subjects
Medicine (General), R5-920, Genetics, QH426-470
Abstract

Claudia Schulte, Thomas GasserDepartment of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tübingen, and German Center for Neurodegenerative Diseases, Tübingen, GermanyAbstract: Parkinson's disease can be caused by rare familial genetic mutations, but in most cases it is likely to result from an interaction between multiple genetic and environmental risk factors. Over recent years, many variants in a growing number of genes involved in the pathogenesis of Parkinson's disease have been identified. Mutations in several genes have been shown to cause familial parkinsonism. In this review, we discuss 12 of them (SNCA, LRRK2, Parkin, PINK1, DJ1, ATP13A2, PLA2G6, FBXO7, UCHL1, GIGYF2, HTRA2, and EIF4G1). Additionally, six genes have been shown conclusively to be risk factors for sporadic Parkinson's disease, and are also discussed (GBA, MAPT, BST1, PARK16, GAK, and HLA). Many more genes and genetic loci have been suggested, but need confirmation. There is evidence that pathways involved in the rare familial forms also play a role in the sporadic form, and that the respective genes might also be risk factors for sporadic Parkinson's disease. The identification of genes involved in the development of Parkinson's disease will improve our understanding of the underlying molecular mechanisms, and will hopefully lead to new drug targets and treatment strategies.Keywords: Parkinson's disease, genetics, SNCA, LRRK2, GBA, MAPT

Published
2011

48. Mendelian Randomisation Study of Smoking, Alcohol, and Coffee Drinking in Relation to Parkinson's Disease

Author

Domenighetti, C. Sugier, P.-E. Sreelatha, A.A.K. Schulte, C. Grover, S. Mohamed, O. Portugal, B. May, P. Bobbili, D.R. Radivojkov-Blagojevic, M. Lichtner, P. Singleton, A.B. Hernandez, D.G. Edsall, C. Mellick, G.D. Zimprich, A. Pirker, W. Rogaeva, E. Lang, A.E. Koks, S. Taba, P. Lesage, S. Brice, A. Corvol, J.-C. Chartier-Harlin, M.-C. Mutez, E. Brockmann, K. Deutschländer, A.B. Hadjigeorgiou, G.M. Dardiotis, E. Stefanis, L. Simitsi, A.M. Valente, E.M. Petrucci, S. Duga, S. Straniero, L. Zecchinelli, A. Pezzoli, G. Brighina, L. Ferrarese, C. Annesi, G. Quattrone, A. Gagliardi, M. Matsuo, H. Kawamura, Y. Hattori, N. Nishioka, K. Chung, S.J. Kim, Y.J. Kolber, P. Van De Warrenburg, B.P.C. Bloem, B.R. Aasly, J. Toft, M. Pihlstrøm, L. Guedes, L.C. Ferreira, J.J. Bardien, S. Carr, J. Tolosa, E. Ezquerra, M. Pastor, P. Diez-Fairen, M. Wirdefeldt, K. Pedersen, N.L. Ran, C. Belin, A.C. Puschmann, A. Hellberg, C. Clarke, C.E. Morrison, K.E. Tan, M. Krainc, D. Burbulla, L.F. Farrer, M.J. Krüger, R. Gasser, T. Sharma, M. Elbaz, A.

Abstract

Background: Previous studies showed that lifestyle behaviors (cigarette smoking, alcohol, coffee) are inversely associated with Parkinson's disease (PD). The prodromal phase of PD raises the possibility that these associations may be explained by reverse causation. Objective: To examine associations of lifestyle behaviors with PD using two-sample Mendelian randomisation (MR) and the potential for survival and incidence-prevalence biases. Methods: We used summary statistics from publicly available studies to estimate the association of genetic polymorphisms with lifestyle behaviors, and from Courage-PD (7,369 cases, 7,018 controls; European ancestry) to estimate the association of these variants with PD. We used the inverse-variance weighted method to compute odds ratios (ORIVW) of PD and 95%confidence intervals (CI). Significance was determined using a Bonferroni-corrected significance threshold (p = 0.017). Results: We found a significant inverse association between smoking initiation and PD (ORIVW per 1-SD increase in the prevalence of ever smoking = 0.74, 95%CI = 0.60-0.93, p = 0.009) without significant directional pleiotropy. Associations in participants =67 years old and cases with disease duration =7 years were of a similar size. No significant associations were observed for alcohol and coffee drinking. In reverse MR, genetic liability toward PD was not associated with smoking or coffee drinking but was positively associated with alcohol drinking. Conclusion: Our findings are in favor of an inverse association between smoking and PD that is not explained by reverse causation, confounding, and survival or incidence-prevalence biases. Genetic liability toward PD was positively associated with alcohol drinking. Conclusions on the association of alcohol and coffee drinking with PD are hampered by insufficient statistical power. © 2022 - IOS Press. All rights reserved.

Published
2022

49. Global Carbon Budget 2022

Author

Friedlingstein, P., O'Sullivan, M., Jones, M. W., Andrew, R. M., Gregor, L., Hauck, J., Le Quéré, C., Luijkx, I. T., Olsen, A., Peters, G. P., Peters, W., Pongratz, J., Schwingshackl, C., Sitch, S., Canadell, J. G., Ciais, P., Jackson, R. B., Alin, S. R., Alkama, R., Arneth, A., Arora, V. K., Bates, N. R., Becker, M., Bellouin, N., Bittig, H. C., Bopp, L., Chevallier, F., Chini, L. P., Cronin, M., Evans, W., Falk, S., Feely, R. A., Gasser, T., Gehlen, M., Gkritzalis, T., Gloege, L., Grassi, G., Gruber, N., Gürses, Ö., Harris, I., Hefner, M., Houghton, R. A., Hurtt, G. C., Iida, Y., Ilyina, T., Jain, A. K., Jersild, A., Kadono, K., Kato, E., Kennedy, D., Klein Goldewijk, K., Knauer, J., Korsbakken, J. I., Landschützer, P., Lefèvre, N., Lindsay, K., Liu, J., Liu, Z., Marland, G., Mayot, N., McGrath, M. J., Metzl, N., Monacci, N. M., Munro, D. R., Nakaoka, S.-I., Niwa, Y., O'Brien, K., Ono, T., Palmer, P. I., Pan, N., Pierrot, D., Pocock, K., Poulter, B., Resplandy, L., Robertson, E., Rödenbeck, C., Rodriguez, C., Rosan, T. M., Schwinger, J., Séférian, R., Shutler, J. D., Skjelvan, I., Steinhoff, T., Sun, Q., Sutton, A. J., Sweeney, C., Takao, S., Tanhua, T., Tans, P. P., Tian, X., Tian, H., Tilbrook, B., Tsujino, H., Tubiello, F., van der Werf, G. R., Walker, A. P., Wanninkhof, R., Whitehead, C., Willstrand Wranne, A., Wright, R., Yuan, W., Yue, C., Yue, X., Zaehle, S., Zeng, J., Zheng, B., Integr. Assessm. Global Environm. Change, and Environmental Sciences

Abstract

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr−1 (9.9 ± 0.5 GtC yr−1 when the cement carbonation sink is included), and ELUC was 1.1 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr−1 (40.0 ± 2.9 GtCO2). Also, for 2021, GATM was 5.2 ± 0.2 GtC yr−1 (2.5 ± 0.1 ppm yr−1), SOCEAN was 2.9 ± 0.4 GtC yr−1, and SLAND was 3.5 ± 0.9 GtC yr−1, with a BIM of −0.6 GtC yr−1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set.

Published
2022

50. Biomechanical Assessment of Macro-Calcification in Human Carotid Atherosclerosis and Its Impact on Smooth Muscle Cell Phenotype

Author

Seime, Till, van Wanrooij, Max, Karlof, Eva, Kronqvist, Malin, Johansson, Staffan, Matic, Ljubica, Gasser, T. Christian, and Hedin, Ulf

Subjects
calcification, Kardiologi, carotid stenosis, Cardiac and Cardiovascular Systems, atherosclerosis, biomechanics, smooth muscle cells
Abstract

Intimal calcification and vascular stiffening are predominant features of end-stage atherosclerosis. However, their role in atherosclerotic plaque instability and how the extent and spatial distribution of calcification influence plaque biology remain unclear. We recently showed that extensive macro calcification can be a stabilizing feature of late-stage human lesions, associated with a reacquisition of more differentiated properties of plaque smooth muscle cells (SMCs) and extracellular matrix (ECM) remodeling. Here, we hypothesized that biomechanical forces related to macro-calcification within plaques influence SMC phenotype and contribute to plaque stabilization. We generated a finite element modeling (FEM) pipeline to assess plaque tissue stretch based on image analysis of preoperative computed tomography angiography (CTA) of carotid atherosclerotic plaques to visualize calcification and soft tissues (lipids and extracellular matrix) within the lesions. Biomechanical stretch was significantly reduced in tissues in close proximity to macro calcification, while increased levels were observed within distant soft tissues. Applying this data to an in vitro stretch model on primary vascular SMCs revealed upregulation of typical markers for differentiated SMCs and contractility under low stretch conditions but also impeded SMC alignment. In contrast, high stretch conditions in combination with calcifying conditions induced SMC apoptosis. Our findings suggest that the load bearing capacities of macro calcifications influence SMC differentiation and survival and contribute to atherosclerotic plaque stabilization.

Published
2022

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