Neurological research
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Neurological research · Mar 1991
Pathological changes in experimental saccular aneurysms in the carotid artery of the rat.
Although the reason for development of saccular aneurysms in humans has still not been elucidated, the process might be observed and explained using a reproducible aneurysm model in vivo. In this paper, a sequential pathological study of the experimental saccular aneurysms was made. ⋯ The imbalance of the degeneration and regeneration processes during the development of these experimental aneurysms is discussed according to the pathological findings in different periods. Haemodynamic stress and different regenerative speeds in different arterial tissues must be responsible for the saccular aneurysm formation and growth.
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Neurological research · Mar 1991
Measurement of regional cerebrovascular haemoglobin oxygen saturation in cats using optical spectroscopy.
We describe the use of optical spectroscopy in the near infra-red light range to non-invasively measure regional cerebral haemoglobin oxygen saturation (rSHbO2) in cats during progressive cerebral hypoxia. This technique differs from spectroscopic techniques previously described in that the concentration ratio--percentage haemoglobin: oxygen saturation--is quantified. This saturation is the weighted summation of saturation in the cerebrovascular system: arterial, venous, and capillary beds. ⋯ During hypoxia spectroscopic indexed oxygen extraction (iOE) and cerebral arterial-venous difference in oxygen content were simultaneously measured. A least-squares positive linear correlation between these two parameters was noted [AVDO2 = iOE (0.05) + 4.4] (n = 40, r = 0.6, s = 1.2). Objective measurement of 'regional cerebrovascular haemoglobin saturation' and an index of cerebral oxygen extraction are possible using optical spectroscopy.