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Biomedical subjects

A L Nilsson

Publications and source records attributed to A L Nilsson.

5 recordsLinked to original sources
PubMed1990

Use of anabolic-androgenic steroids among body builders--frequency and attitudes.

A total of 138 male body builders who regularly attended a gym participated anonymously in a study of the use of anabolic-androgenic steroids in relation to side-effects, blood pressure, body mass index (BMI; kg m-2), training frequency, social background, occupation, knowledge and attitudes to steroid use. Fifty-three of the 138 body builders had used anabolic-androgenic steroids for a median duration of 2 years. Steroid use was linked to a higher BMI and more frequent training. Seventy-five per cent (n = 18) of those attending body building for competition, and 24% (n = 11) of those attending to improve their sense of well-being, used anabolic-androgenic steroids. Of all body builders, 94% considered anabolic-androgenic steroids to be dangerous. Of the users, 81% experienced side-effects, but 74% still intended to continue steroid medication.

Adult↗
PubMed1987

Blood flow, temperature, and heat loss of skin exposed to local radiative and convective cooling.

The relationship between skin blood flow (SBF) and temperature was evaluated and the heat loss calculated for locally applied thermal stimuli. In 10 subjects the palm was exposed to room climate, pure convective air currents, and pure radiation, which resulted in skin temperatures between 23 and 36 degrees C. Skin blood flow was estimated by laser Doppler flowmetry and local skin temperature was measured by a thermistor probe. Linear regression of SBF on skin temperature revealed significant correlations (r = 0.87, p less than 0.05) within subjects and large variations in estimated slopes (s/m = 34%) between subjects. Therefore, SBF was normalized to the room climate value in each separate experiment. When skin temperature and normalized SBF from all subjects were included in the regression analysis, a nearly linear relationship was confirmed (r = 0.88, p less than 0.0005). Radiative cooling (17 degrees C) doubled the heat loss, reduced skin temperature by 3.7 degrees C, and left SBF virtually unchanged compared with room climate values. When convective cooling (19 degrees C) was applied at 2 air current velocities (0.5 and 1.0 ms-1), palm blood flow diminished to 60 and 53%, respectively, of room climate values. Corresponding heat losses with convective cooling decreased to 68 and 70%, respectively, of room climate values. Linear regression of local heat loss on normalized SBF gave a significant correlation coefficient of 0.79 (p less than 0.001).

Adolescent↗
PubMed1986

Effects of local convective cooling and rewarming on skin blood flow.

Local areas of the thighs, palms and fingertips of ten healthy subjects were exposed to cold (10 degrees C) and warm (40 degrees C) air flows of three different velocities, 0.25, 0.50 and 0.75 m/s. The rewarming followed immediately after the cooling. Each climatic condition was applied for 45 min. Skin blood flow and skin temperature were continuously measured by laser Doppler flowmetry and thermometry, respectively. Significant (p less than 0.01 or less) reductions in both skin blood flow and skin temperature, compared to the levels recorded in the room climate, were observed at all the test sites and for all the cooling climates. During cooling no significant differences were obtained between skin blood flow levels reached for the different air velocities, except for the palm (p less than 0.01). Rewarming by the air velocities 0.25 and 0.50 m/s could not even bring the palm skin blood flow back to the precooling levels, while the fingertip (except for the low air velocity) and the thigh showed a hyperaemic reaction. The discrepancies in response pattern between the test sites are interpreted to be due to their different microvasculature and vasomotor innervation. The relationship between skin blood flow and skin temperature was found to be exponential. The correlation coefficients were 0.84, 0.72 and 0.85 for the thigh, palm and fingertip, respectively.

Adolescent↗
PubMed1982

On periodic sweating from the human skin during rest and exercise.

The rhythmic variations in the water evaporation rate (gm-2h-1,) from the dorsal side of the forearm have been studied. The evaporation rate is estimated by calculating the difference between the vapour pressures at two distinct points on a line perpendicular to the evaporative surface. Using autocorrelation technique it is found that the evaporation rate is periodic with a period of around 0.7 s. This value is consistent, at rest as well as prior to profuse sweating in exercise, for all the subjects included in the investigation. During profuse sweating the period becomes slightly longer. It is suggested that the variations in the evaporation rate reflect the periodic activity in the sudomotor nerves.

Adult↗