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Biomedical subjects

E Wigaeus

Publications and source records attributed to E Wigaeus.

6 recordsLinked to original sources
PubMed1984

Uptake, distribution, metabolism, and elimination of styrene in man. A comparison between single exposure and co-exposure with acetone.

Six male subjects were exposed for two hours during light physical exercise to 2.81 mmol/m3 (293 mg/m3) of styrene on one occasion and to a mixture of 2.89 mmol/m3 (301 mg/m3) of styrene and 21.3 mmol/m3 (1240 mg/m3) of acetone on another (combination study). About 68% of the dose (somewhat more than 4 mmol) of styrene was taken up. The arterial blood concentration of styrene reached a relatively stable level after about 75 minutes of exposure of about 18 and 20 mumol/l after the single and combined exposure, respectively. Calculated values of mean blood clearance were 1.9 l/min in the styrene study and 1.6 l/min in the combination study; the half life of styrene in blood was about 40 minutes in both studies. The concentration of non-conjugated styrene glycol increased linearly during exposure and reached about 3 mumol/l at the end of exposure and was eliminated with a half life of about 70 minutes. Styrene-7,8-oxide was detected and quantified in the blood in a complementary study. The half lives for the excretion of mandelic and phenylglyoxylic acid in the urine were about four and nine hours, respectively, in both studies.

Acetone↗
PubMed1983

Exposure to styrene. Uptake, distribution, metabolism and elimination in man.

Exposure to styrene: Uptake, distribution, metabolism and elimination in man. Scand j work environ health 9 (1983) 479-488. Eight male subjects were exposed for 2 h to about 2.88 mmol/m3 (300 mg/m3) of styrene vapor during light physical exercise. The uptake of styrene averaged 4.4 mmol, or 68% of the amount supplied. The arterial blood concentration of styrene reached a relatively stable level of about 20 mumol/l after 75 min of exposure. The calculated value of blood clearance was 1.7 (SD 0.3) l/min, and the extraction ratio about 0.2. The half-time for the elimination phase was 41 (SD 7) min, and the calculated volume of distribution 99 (SD 13) l. The concentration of styrene in the subcutaneous adipose tissue was about 50 mumol/kg 30-90 min after exposure. The concentration of nonconjugated styrene glycol in blood increased linearly during exposure and was about 15% of the styrene concentration in blood at the end of exposure. It was eliminated with a half-time of 72 (SD 13) min. Within 28 h after exposure 58% of the total uptake of styrene was recovered in the urine as mandelic and phenylglyoxylic acid. Their excretion half-times (0-20 h) were 3.6 (SD 0.4) and 8.8 (SD 1.3) h, respectively. Styrene-7,8-oxide was detected and quantified in blood in a complementary study.

Adipose Tissue↗
PubMed1982

Distribution and elimination of 2-[14C]-acetone in mice after inhalation exposure.

This study was undertaken to determine the tissue distribution and elimination of acetone and its metabolic radioactive fragments in mice after exposure to about 1,200 mg/m3 (500 ppm) of 2-[14C]-acetone vapor. The tissue concentrations of acetone seemed to reach steady state plateaus within 6 h of exposure. In the adipose tissue the maximal concentration was about one-third of that in the highly perfused nonadipose tissues, in which acetone was rather evenly distributed. The contents of radioactivity also reached a plateau within 6 h of exposure in all tissues except the liver and brown adipose tissue. In these tissues the radioactivity increased during exposures up to 24 h. Prolonging the exposure time from 6 h to 6 h/d for three and five consecutive days gave no or only a small additional accumulation of radioactivity in all tissues except adipose tissue. The half-times of acetone after 6 h of exposure were between 2 and 5 h in all tissues. Almost equal amounts of acetone were excreted via the lungs unmetabolized or metabolized to carbon dioxide. In all tissues endogenous levels of acetone were reached within 24 h after exposure. Thus, acetone did not accumulate after prolonged or repeated exposure to concentrations of 1,200 mg/m3.

Acetone↗
PubMed1981

Exposure to acetone. Uptake and elimination in man.

Eight male subjects were exposed to acetone vapor on two occasions for 2 h in the laboratory. On the first occasion they were exposed to about 1,300 mg/m3 during rest and on the second occasion to about 700 mg/m3 during rest (30 min) and exercise at different work loads on a bicycle ergometer (90 min). The total uptake of acetone was 0.6--1.2 g, and the relative uptake was about 45%. The concentration of acetone in alveolar air was 30--40% of that in the inspiratory air, and it was not affected by exposure time or work load. The concentration of acetone in blood increased continuously with increased uptake during exposure, and there was no tendency towards equilibrium. The half-time of acetone in alveolar air as about 4 h, and in venous and arterial blood it was about 6 and 4 h, respectively. The highest concentrations of acetone in urine were measured 3--3.5 h after exposure. The elimination of acetone via the lungs corresponded to about 20% of the total uptake. Only about 1% of the uptake was excreted via urine.

Acetone↗
PubMed1980

Physical demands during folk dancing.

This investigation was undertaken to evaluate the aerobic demands during one of the most popular and demanding Swedish folk dances the "hambo". Six men and six women, ranging in age from 22 to 32, participated. Their physical work capacity was investigated on a bicycle ergometer and a treadmill, using two to three submaximal and one maximal loads. All subjects were moderately well-trained and their average maximal oxygen uptake on the treadmill were 2.5 and 3.7 l/min (42.8 and 53.2 ml/kg . min-1) for women and men, respectively. When dancing the "hambo" the heart rate was telemetered, and the Douglas bag technique was used for measurements of pulmonary ventilation and oxygen uptake. The physical demand during "hambo" dancing was high in all subjects. Oxygen uptake was 38.5 and 37.3 ml/kg . min-1 and heart rate 179 and 172 in women and men, respectively. Women used 90% and men 70% of their maximal aerobic power obtained on the treadmill. The pulmonary ventilation and respiratory quotient of the female subjects were lower when dancing as compared to running, possibly because of voluntary restriction of the movements of the thoracic cage. Some popular Scandinavian folk dances are performed at a speed and with an activity pattern resembling the "hambo", while others are performed at a slower pace. The exercise intensity used in "hambo" is more than sufficient to induce training effects in the average individual provided that the dancing is performed at the frequency and for length of time usually recommended for physical training. For older or less fit people dances with a slow pace can be used for training purposes.

Adult↗