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  • Author or Editor: H. J. Koch x
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Nineteen healthy volunteers were exposed to a standardized exercise test at sea level (SLa), at an altitude of 1700 m before (1700a) and after a moderate 10-day mountain training (1700b), with a final control four weeks later at sea level (SLb). Vital signs, blood lactate and arterial oxygen saturation were determined prior, during or after the exercise test. Whereas systolic blood pressure and heart rate at rest did not change substantially, diastolic blood pressure decreased at the final control (SLb, p<0.05) and oxygen saturation was significantly lower at 1700 m (1700a, 1700b, p<0.01). Lactate at rest increased from 1.16 (SLa) to 1.97 (1700a) mmol/l after acute exposure followed by a slight reduction after adaptation (p<0.05). The mean maximum lactate levels were as follows: 6.03, 10.56, 6.22 and 8.75 (p<0.01). The mean maximum performance increased during the study (225.6, 223.3, 231.6, 248.1 Watt, p<0.01). Lactate versus workload curves did not show a marked shift to the right. No significant changes of maximum heart rates during the exercise test were found. In conclusion, a sojourn at 1700 m provokes an increase of lactate levels with subsequent reduction after acclimatization and has a significant positive impact on the mean maximum performance after moderate mountain training.

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19-channel-EEGs were recorded from scalp surface of 30 healthy subjects (16m, 14f, mean age: 34 ys, SD: 11.7 ys) at rest and under IPS (Intermittent Photic Stimulation) at rates of 5, 10 and 20 Hertz (Hz). Digitalized data underwent spectral analysis with fast fourier transformation (FFT) yielding the basis for the computation of global field power (GFP). For quantification GFP values in the frequency ranges of 5, 10 and 20 Hz at rest were divided by the corresponding data gained under IPS. While ratios from PDE data showed no stable parameter due to high interindividual variability, ratios of alpha-power turned out to be uniform in all subjects: IPS at 20 Hz always led to a suppression of alpha-power. Dividing alpha-GFP at rest by alpha-GFP under 20-Hz IPS thus resulted in a ratio <1. We conclude that ratios from GFP data are a stable diagnostic paradigma.

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The pathogenesis of chicken infectious anaemia virus (CAV) infection was studied in 6-week-old and one-day-old SPF chickens inoculated intramuscularly with graded doses of Cux-1 strain (106−102 TCID50/chicken). Viraemia, virus shedding, development of virus neutralizing (VN) antibodies and CAV distribution in the thymus were studied by virus isolation, polymerase chain reaction (PCR), immunocytochemistry (IP) and in situ hybridization until postinfection day (PID) 28. In 6-week-old chickens infected with high doses of CAV, viraemia and VN antibodies could be detected 4 PID and onward without virus shedding or contact transmission to sentinel birds. However, virus shedding and contact transmission were demonstrated in one-day-old infected chickens. In the 6-weekold groups infected with lower doses, VN antibodies developed by PID 14, transient viraemia and virus shedding were detected. The thymus cortex of all 1-dayold inoculated chickens stained with VP3-specific mAb. Cells with positive in situ hybridization signal were fewer and scattered throughout the thymus tissue of the one-day-old inoculated chickens as compared to IP-positive cells. These results suggest that early immune response induced by high doses of CAV in 6-week-old chickens curtails viral replication and prevents virus shedding.

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