Subject(s)
Ethics, Medical , Neurology/ethics , Neurosciences/ethics , Psychiatry/ethics , Germany , HumansABSTRACT
Motor-independent communication is a novel diagnostic and therapeutic method that is currently in development in order to enable communication with severely physically challenged patients. Some patients with locked-in syndromes or with chronic disorders of consciousness are capable of modulating their brain activities to such a degree that the latter can be analyzed regarding communicative intentions with neuroscientific technologies, such as functional magnetic resonance imaging. Further scientific development and an increasing clinical use of motor-independent communication will aid in meeting essential quality standards for this method. In particular, the requirements need to be clarified under which the method may be utilized to support the patients' autonomy by enabling them to make their own decisions about therapeutic interventions. Communication mediated by technology promises to significantly improve the quality of life for severely physically challenged patients.
Subject(s)
Cerebral Cortex/physiopathology , Communication Aids for Disabled , Disabled Persons/psychology , Disabled Persons/rehabilitation , Electroencephalography , Magnetic Resonance Imaging , Nonverbal Communication , Persistent Vegetative State/physiopathology , Persistent Vegetative State/psychology , Personal Autonomy , Quadriplegia/physiopathology , Quadriplegia/psychology , Brain Mapping , Brain Waves/physiology , Combined Modality Therapy , Humans , Mental Processes/physiology , Patient Participation , Persistent Vegetative State/rehabilitation , Quadriplegia/rehabilitationABSTRACT
BACKGROUND: The aim of this study was to determine the glucose-dependent regulation of the sodium-proton-antiporter (Na+/H+ antiporter) in patients with mild chronic renal failure (CRF). METHODS: We measured plasma glucose concentrations, plasma insulin concentrations, plasma C peptide concentrations, arterial blood pressure, cytosolic pH (pHi), cellular Na+/H+ antiporter activity, and cytosolic sodium concentration ([Na+]i) in 19 patients with CRF and 41 age-matched healthy control subjects (control) during a standardized oral glucose tolerance test. Intracellular pHi, [Na+]i, and Na+/H+ antiporter activity was measured in lymphocytes using fluorescent dye techniques. RESULTS: Under resting conditions, the pHi was significantly lower, whereas the Na+/H+ antiporter activity was significantly higher in CRF patients compared with controls (each P < 0.0001). The oral administration of 100 g glucose significantly increased the Na+/H+ antiporter activity in CRF patients from 13.35 +/- 1.26 x 10-3 pHi/second to 16.44 +/- 1.37 x 10-3 pHi/second after one hour and to 14.06 +/- 1.36 x 10-3 pHi/second after two hours (mean +/- SEM, P = 0.008 by Friedmans's two-way analysis of variance). In controls, the administration of 100 g glucose significantly increased the Na+/H+ antiporter activity from 4.23 +/- 0.20 x 10-3 pHi/second to 6.00 +/- 0.56 x 10-3 pHi/second after one hour and to 6.65 +/- 0.64 x 10-3 pHi/second after two hours (P = 0.0003). The glucose-induced enhancement of the Na+/H+ antiporter activity was more pronounced in CRF patients compared with controls (P = 0.011). Resting [Na+]i was not significantly different between the two groups. CONCLUSIONS: CRF patients show an intracellular acidosis leading to an increased Na+/H+ antiporter activity. In addition, high glucose levels exaggerate the differences in Na+/H+ antiporter activity already present between cells from patients with mild CRF and those from control subjects.
