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Introduction
Published in Laurence J. Street, Introduction to Biomedical Engineering Technology, 2016
Red blood cells carry various proteins and carbohydrates on their cell membranes, and the type and arrangement of these substances varies between individuals. If the membrane surfaces of two individuals are similar, they are said to have the same blood type. The broadest and most commonly referenced blood types are A, B, AB, and O, each of which can have a particular characteristic (the Rh factor) either present (positive) or absent (negative). If these main blood types are compatible, one individual can accept a blood donation from another. Blood types have a great deal more complexity than this, but the basic descriptions are sufficient for this text.
Lessons for Bionanointeractions from Colloidal Science
Published in Victor M. Starov, Nanoscience, 2010
Iseult Lynch, Dominique Langevin, Kenneth A. Dawson
Blood was taken from seemingly healthy donors. The blood donation was arranged such that the blood samples were labeled anonymously. They could not be traced back to a specific donor; however, it was possible to use plasma from just one of the donors for a specific experiment. The tubes were centrifuged, for 5 min at 800 RCF to pellet the red and white blood cells. The supernatant (the plasma) was transferred to labeled tubes and stored at −80°C until used. Upon thawing, the plasma was centrifuged again for 3 min at 16.1 kRCF to further reduce the presence of red and white blood cells. The supernatant was transferred to a new vessel; taking care not to disturb the pellet.
Introduction
Published in Laurence J. Street, Introduction to Biomedical Engineering Technology, 2023
Red blood cells carry various proteins and carbohydrates on their cell membranes, and the type and arrangement of these substances vary between individuals. If the membrane surfaces of two individuals are similar, they are said to have the same blood type. The broadest and most commonly referenced blood types are A, B, AB, and O, each of which can have a particular characteristic (the Rh factor) either present (positive) or absent (negative). If these main blood types are compatible, one individual can accept a blood donation from another. Blood types have a great deal more complexity than this, but the basic descriptions are sufficient for this text.
Marked improvements in cardiac function in postmenopausal women exposed to blood withdrawal plus endurance training
Published in Journal of Sports Sciences, 2022
Candela Diaz-Canestro, Christoph Siebenmann, David Montero
Studies in older men have observed substantial haematological and cardiac adaptations when ET is combined with additional interventions facilitating PV expansion and thereby haemodilution (Okazaki et al., 2009). The latter entails additional haemodynamic demands on the heart, which must pump more blood per unit of time to deliver a given amount of oxygen (O2) to the systemic circulation (Calbet et al., 2006; Freedson, 1981). Women might thus benefit from ET programmes including supplemental stimuli for volumetric adaptations, increasing PV and thereby cardiac output during exercise. Paradoxical as it may seem, a well-established approach to persistently increase PV as well as cardiac work is blood withdrawal (Calbet et al., 2006; Freedson, 1981; Van Remoortel et al., 2017). A standard blood donation (~500 ml of blood, ~10% reduction of BV) prompts haemodilution due to acute PV expansion, which almost completely restores BV in 24–48 hr (Calbet et al., 2006). Yet, the absolute recovery of red blood cell count and Hb concentration may take over 6 months owing to the slow production of red blood cells, notably in women (Niittymaki et al., 2017). Importantly, cardiac output during submaximal exercise remains markedly augmented (+10%) in proportion to the decrease of Hb concentration induced by blood withdrawal in healthy individuals (Freedson, 1981). Haemodynamic stimuli for heart adaptations may be magnified for a prolonged period after blood withdrawal as a result of sustained haemodilution. Even in sedentary individuals, chronic augmentation of resting cardiac output with mild-to-moderate persistent decreases of Hb concentration is associated with cardiac chamber enlargement and prevalent LV hypertrophy (Georgieva & Georgieva, 1997; Pereira & Sarnak, 2003). Whether the combination of blood withdrawal and ET may overcome the generalized limitations to improve CRF in female populations has yet to be elucidated.