Browsing by Subject "leukocytes"

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    Characterization of Blast-Induced Activation of Human Immune Cells
    (2012) Garrett, Joel Frederick

    Blast related injuries have become a common occurrence among soldiers and civilians serving in Iraq and Afghanistan, and minor traumatic brain injuries associated with such incidents have increased correspondingly. Advances in protection and treatment have allowed many individuals to survive what would have previously been deadly blasts but there is a concern that there are additional negative side effects associated with such exposure. This study hypothesizes that human T leukocytes and promyelocytes respond to blasts by initiating cell death processes and releasing microparticles that could lead to further systemic inflammation. It was found that there was a significant (p<0.05) increase in lactase dehydrogenase activity and microparticle release in HL-60 cells blasted using a shock tube (with an incident blast overpressure of either 1000 or 1300 kPA and a duration of 2 ms) compared to control populations after 24 hours. There were no corresponding increases in Jurkat cells exposed to similar conditions.

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    Telomeres and the natural lifespan limit in humans.
    (Aging (Albany NY), 2017-04) Steenstrup, Troels; Kark, Jeremy D; Verhulst, Simon; Thinggaard, Mikael; Hjelmborg, Jacob VB; Dalgård, Christine; Kyvik, Kirsten Ohm; Christiansen, Lene; Mangino, Massimo; Spector, Timothy D; Petersen, Inge; Kimura, Masayuki; Benetos, Athanase; Labat, Carlos; Sinnreich, Ronit; Hwang, Shih-Jen; Levy, Daniel; Hunt, Steven C; Fitzpatrick, Annette L; Chen, Wei; Berenson, Gerald S; Barbieri, Michelangela; Paolisso, Giuseppe; Gadalla, Shahinaz M; Savage, Sharon A; Christensen, Kaare; Yashin, Anatoliy I; Arbeev, Konstantin G; Aviv, Abraham
    An ongoing debate in demography has focused on whether the human lifespan has a maximal natural limit. Taking a mechanistic perspective, and knowing that short telomeres are associated with diminished longevity, we examined whether telomere length dynamics during adult life could set a maximal natural lifespan limit. We define leukocyte telomere length of 5 kb as the 'telomeric brink', which denotes a high risk of imminent death. We show that a subset of adults may reach the telomeric brink within the current life expectancy and more so for a 100-year life expectancy. Thus, secular trends in life expectancy should confront a biological limit due to crossing the telomeric brink.