Signals Analysis and Clinical Validation of Blood and Oxygen Data in Human Brain

With a self-made near-infrared analytical instrument to blood and oxygen parameters in human brain, 80 cases in which 20 are healthy persons and 30 are anaesthetised cases and others are patients with heart function lack is taken to examine, and the data of blood and oxygen in brain tissue were collected and analyzed by the method of power spectrum and correlation function. The results indicate that: (1) The average brain oxygen saturation of healthy persons and anaesthetised cases is about 80%, in accord with normal parameter of physiology. Contrastively, the average brain oxygen saturation of patients with heart function lack is 72.8%, which is obviously less than that of healthy persons and anaesthetised cases. The probability of medical statistics is less than 0.01. (2) The shapes of wave of brain blood and oxygen for the healthy person and the anaesthetised case reveal small periodical fluctuations with stable shape and base line, and the trend of increase or decrease of blood and oxygen parameters in brain tissue is synchronous and a phase reversal, but for the patient with heart function lack in a brain oxygen lack state, the shapes of wave are irregular. This is a hint that near infrared light passing through tissue can reflect the intuitionistic change of brain blood and oxygen parameters.(3) The power spectra of brain blood and oxygen for the healthy person and the anaesthetised case has a clear main peak, narrow bandwidth and perfect superposition each other, but the power spectra for the patient with heart function lack in a brain oxygen lack state is on the contrary.(4) The average cross correlation coefficient of brain blood and oxygen for healthy persons and anaesthetised cases is -0.9825±0.1027 close to -1. But the average cross correlation coefficient for patients with heart function lack in a brain oxygen lack state is merely -0.8923±0.1035 which is obviously greater than -1 and the probability of medical statistics is less than 0.01. The clinic experiments have proved that the shapes of waves, the power spectrum and cross correlation coefficient of brain blood and oxygen are useful to analyze the physiological status and changes of blood and oxygen in human brain.

An inhibition of ceruloplasmin expression induced by cerebral ischemia in the cortex and hippocampus of rats

Objective To explore effects of cerebral ischemia on the ceruloplasmin （Cp） expression in the cortex and hippoc-ampus of rats. Methods Male Wistar rats were randomly divided into cerebral ischemia group and control group. Cerebral ischemia was induced by ligating bilateral common carotid arteries and the ischemic rats were further subgrouped according to ischemia time. The control rats received a sham operation. The expression of Cp mRNA in the cortex and hippocampus was measured by reverse transcription polymerase chain reaction （RT-PCR）. The Cp expression was shown by immunohistochemistrical （streptavidin peroxidase, SP） method. Results In ischemia group, the expression of Cp mRNA in the cortex and hippocampus decreased compared with that in control group （P 〈 0.01）; and the longer rats experienced cerebral ischemia, the lower Cp mRNA expressed. By immunohistochemistry, Cp was shown expressed in the neural cells including epithelial cells of choroid plexus, ependymal cells, astrocytes of cortex and hippocampus, and vascular endothelial cells, but not in pyramidal cells and granulosa cells of cortex and hippocampus. Cp levels in the cortex and hippocampus decreased in rats suffering from cerebral ischemia for 3 d, 7 d and 28 d but not in rats exposed to ischemia for 1 d compared with that in control group （P 〈 0.05）. Iron concentration correlated negatively with Cp expression in the cortex and hippocampus of rats exposure to ischemia （the cortex, r=-0.831, P〈0.01; the hippocampus, r=-0.809, P〈0.01）. Conclusion Cerebral ischemia inhibited Cp expression in the cortex and hippocampus of rats. The decrease of Cp might be involved in iron deposition in neurons.