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However, because collagen I is the main constituent of CAs and because we generally excised and analyzed ≥2/3 of the aneurysm dome, the birth dating measurements are likely to reflect the majority of the aneurysmal mass.
In addition, we can only estimate relative collagen turnover using radiocarbon birth dating as an indicator because the total collagen content in human CA samples cannot be monitored over time.
The bone material was collected from 3 necropoles of the Bronze Age period in Cyprus (Erimi-Laonin tou Porakou, Lophou-Kolaouzou, and Erimi-Kafkalla&Pitharka, along the Kouris Valley), an area characterized by environmental conditions that do not favor bone preservation.
Samples were treated to extract collagen and measured by accelerator mass spectrometry (AMS).
M.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Institute for Physiological Chemistry and Pathobiochemistry, Westfalian Wilhelms-University, Münster, Germany (R. B.); Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, CA (B. B.); Department of Epidemiology, University of Iowa (J. T.); Department of Neurology, Mayo Clinic, Rochester, MN (R. Furthermore, it cannot be ascertained whether the age of collagen is different in the neck or in the remaining CA tissue.
Michael’s Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. In addition, cerebral arteries do not comprise a large tunica adventitia as a fibrous tissue component, which explains the relative absence of collagen type I. Because of the cross-sectional nature of our study and the lack of CA samples that have been followed up for many years, we cannot draw definite causal inferences about the actual chronological onset of aneurysm formation or a potential association with a heightened risk of CA rupture.
Michael’s Hospital, Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. In addition, the existing knowledge on collagen turnover in arteries is mainly derived from animal models or extracranial vessels.
It is concluded that there is no unequivocal way to detect natural levels of contamination with the discussed parameters, although their use can identify many cases.
In low “collagen” bone, the parameters can identify the great majority of problematic samples: although deviations in these parameters do not necessarily mean isotopic alterations, the increased background found in these samples makes most samples unusable.
M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R. Aside from our preliminary birth dating study in a small patient cohort, data to support or challenge this concept are mainly derived from animal studies or mathematical models and observational studies of human CAs.
The prevailing concept remains that there are different populations of small CAs, including those that grow and reach a stable size, those that continue to enlarge and either reach a stable larger size or rupture over the long term, and those that form, enlarge, and then rupture over a relatively short period of time.
In a combustion and graphitization setup like that installed at INFN-LABEC, Florence, measurement can be easily performed using an elemental analyzer when combusting the sample prior to graphitization, thus requiring no extra effort (or extra amount of sample) during the preparation procedure.