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A Wennberg

Publications and source records attributed to A Wennberg.

95 records · Page 6Linked to original sources
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Electrocortical responses to ecologically relevant visual stimuli among professional drivers with and without cardiovascular disease.

Electrocortical responses were assessed using two simulated aspects of visual signals encountered in traffic: the Glare Pressor Test (GPT) and Event-Related Potential Avoidance Task (ERPAT) among four groups of male professional drivers: 12 with ischemic heart disease (IHD), 12 hypertensives, 10 borderline hypertensives, 34 who were apparently healthy and 23 nonprofessional driver healthy control subjects. The blood pressure (BP) responses immediately after the ERPAT were also measured. There was a significant between groups effect for the amplitude of the target N2 component in the ERPAT (p = 0.02), with the lowest means among the drivers with IHD and the highest among those with hypertension. Drivers with IHD also showed the highest diastolic BP reactivity to the ERPAT. Significantly more than the expected number of drivers with IHD failed to recover alpha activity after the first glare impulse of the GPT. Professional drivers who failed to recover baseline levels of alpha activity after the GPT showed a significantly smaller N2 amplitude compared to those who recovered (p = 0.01). There was a positive correlation between abundance of alpha activity at rest with P300 amplitude (p = 0.02). An inverse relation was found between number of work hours behind the wheel and the amplitude of the target P300 (p = 0.04). Results are interpreted in light of recent advances concerning integrative mechanisms of defence versus vigilance response patterns. The findings in this study justify further applications of these psychophysiologic methods to assess the relationship between simulated signals of the work environment and mechanisms of cardiac risk in this occupational group.

Adult↗
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Total parenteral nutrition with different ratios of fat/carbohydrate at two energy levels: an animal study.

Different regimens of total parenteral nutrition were evaluated in 64 growing rats, during a 10-day period. Thirty-two rats were kept at a low energy regimen (270 kcal/kg body weight per day), and the remaining rats were infused with a high energy solution (350 kcal/kg/day). At each energy level, four fat/carbohydrate (CHO) nonprotein energy ratios were tested: 0% fat/100% CHO (no fat); 6% fat/94% CHO (low fat); 30% fat/70% CHO (medium fat); 60% fat/40% CHO (high fat). A daily supply of 0.9 g nitrogen/kg of a well balanced amino acid solution was administered to all rats. Growth, nitrogen balance, net nitrogen utilization, and blood status were evaluated. Carcass, liver, and muscle composition were investigated with respect to protein, fat, and water content. Liver and body composition was similar between groups at the same energy level. At the higher energy level the fat deposition was increased. At the low energy level, rats from no fat and low fat groups lost weight during the first 3 days of the experimental period. The medium fat groups showed the highest weight gain at each energy level. This suggests the importance of the presence of fat in total parenteral nutrition programs. During the last days of the experimental period, all rats gained weight, and showed a positive nitrogen balance. All groups given 350 kcal/kg/day gained weight more rapidly and showed a better nitrogen balance and utilization than the corresponding group given 270 kcal/kg/day. This study emphasizes that a well-balanced proportion of energy and substrates is important.

Animals↗