The aim of the study was to analyse protective effects of different doses of pomiferin in therapy of reperfusion injury. Rats were randomly divided into five groups (n=10). One group was intact. Three medicated groups and one placebo group were subjected to ischaemia and reperfusion of the left kidney. Pomiferin was administrated by single gastric gavage in 2 ml of 0.5% Avicel solution in doses of 5, 10 and 20 mg/kg. The placebo group was given only Avicel solution. On day 15, all the animals were exsanguinated and the reperfused kidneys were recovered. Selected biochemical markers were assessed in blood: antioxidative enzymes, total antioxidative capacity, malondialdehyde, creatinine, urea and uric acid. Creatinine, urea and total proteins were analysed in urine and 24-hour diuresis was recorded. The kidney tissue samples were used for histopathological examination. The results confirmed the expected protective effects of pomiferin. Pomiferin supported defensive reactions of the body against free radicals (increased levels of superoxide dismutase, total antioxidative capacity), decreased lipid peroxidation (decreased malondialdehyde) and contributed to the recovery of kidney functions (creatinine and urea in blood). The best biochemical and histopathological results were achieved after pomiferin administration in the dose of 5 mg/kg.
AIMS: To assess the impact of cognitive task solving on respiratory and cardiovascular parameters. METHODS: The ML870B80 Exercise Physiology System was used to record concurrently with EEG, the cardiorespiratory and metabolic functions of subjects during cognitive activity. The Expired Minute Ventilation (VE), Oxygen Consumption (VO2), Carbon Dioxide Production (VCO2) and Average Heart Rate (BPM) were ascertained for four periods: (1) rest or starting period, (2) reference period, (3) cognitive task solving period and (4) recovery period. Each period was defined by the type of presented visual stimuli and by the prearranged cognitive activity related to visual stimuli. The personality traits of participants were also determined. RESULTS: The momentary functional state of subject's brain (i.e. the period of the experiment) determined the average values of all measured parameters. During the cognitive task solving period the average VE, VO2 and VCO2 reached the lowest values while the HR behaved reversely--it was the highest in the cognitive task solving period. Further, the average VE, VCO2 and HR values but not VO2 value differed significantly from average values for the same variable measured in the rest period. CONCLUSION: The changes in respiratory variables during the cognitive task solving period predicate the whole-body metabolic rate rather than the energy metabolism of the brain alone. However, the heart rate related to some personality traits of the subject has a tighter relation to brain's energy metabolic rate during the cognitive task solving--it affects the oxygen supply of the brain.
AIMS: To analyze the event-related desynchronization/synchronization (ERD/ERS) attended with the mental load arising while solving two cognitive tasks. The features of the presented visual stimulus determined the type of cognitive task that should be solved. METHODS: For each experimental task and everybody's subject FFT Analysis module calculated the total power histograms from a fixed frequency band (3-20 Hz or 8-13 Hz) for each 3-second EEG sample with 50 % overlay and all electrodes. From the histograms the software derived two FFT single values--the average Total Power (TP) and Frequency at Maximum Power (FMP). RESULTS: It has been shown that during the solution of cognitive tasks the marked changes of ongoing EEG activity appeared. The short lasting and localized amplitude decrease in rhythmic activity (ERD) and the change of EEG frequency were among the most frequent. The ERD extent was determined by an informational content of processed visual stimuli and by the site of scalp-recording electrode. A higher mental load related to the solution of cognitive tasks shifted the average FM to lower frequencies. CONCLUSION: The suitability of an analysis of ongoing EEG activity to uncover differences in people's brain activation patterns when engaged in performing cognitively demanding tasks was proved.
