PubMed Health⌕ Search

Biomedical subjects

W Kroll

Publications and source records attributed to W Kroll.

At least 37 records · Page 2Linked to original sources
PubMed1980

Regional adipose cellularity and reliability of adipose cell size determination.

Regional adipose cell size was assessed in 18 males ranging in age from 20 to 36 years. These measures were correlated to total body fat determined by hydrostatic weighing. Adipose samples were removed from the gluteal, abdominal, and subscapular regions using a needle aspiration technique. The tissue was incubated in collagenase to release individual cells that were immediately photographed under a microscope. To establish the reliability of adipose cell size assessment over time, fat biopsies were secured on 2 separate days. No significant difference was found for any region between day 1 and 2 adipose cell measures. Gluteal cell diameter (90.3 mu) was significantly larger than the abdominal (81.0 mu) and subscapular (78.6 mu) cell diameter (90.3 mu) was significantly larger than the abdominal (81.0 mu) and subscapular (78.6 mu) cell diameters. Total body fat correlated highest with gluteal cell size (r = 0.76) compared with the abdominal (r = 0.67) or subscapular (r = 0.70) regions. This study also examined the number of adipose cells required to subscapular (r = 0.70) regions. This study also examined the number of adipose cells required to obtain a reliable and representative mean value of adipose cell size. Using a sequential estimation analysis it was found that adipose cell diameters of the abdominal, gluteal, or subscapular regions can be reliably estimated with fewer than 100 cells.

Abdomen↗
PubMed1980

Plantar flexion fatigue and muscle fiber type in power and endurance athletes.

Plantar flexion fatigue and muscle fiber type in power and endurance athletes. Med. Sci. Sports Exercise, Vol. 12, No. 4, pp. 262-267, 1980. The relationship between isometric plantar flexion strength fatigue patterns and muscle fiber type composition of the gastrocnemius was assessed in endurance (N = 8) and power (N = 8) trained males. Following baseline strength assessment, subjects were administered two different 25 trial isometric exercise regimens: on one exercise day each 10-sec fatigue trial was separated by a five-sec intertrial rest period, while on the second exercise day the 10-sec fatigue trials was separated by a 20-sec intertrial rest periods. Muscle biopsies were secured from the right medial gastrocnemius. Significantly different fatigue patterns resulted between power and endurance groups, with the power group fatiguing five times faster than the endurance group in the 10.5 condition and demonstrating more complex fatigue curves in both exercise conditions. Slow twitch fiber percent number correlated with rate of fatigability as measured by linear trend coefficients in power (r = .84) and endurance groups (r = .26). Rate of fatigability correlated with maximum isometric strength in both power (r = -.66) and endurance (r = .86) groups. Thus, maximum isometric strength was a better predictor of rate of fatigability than muscle fiber type composition.

Fatigue↗
PubMed1979

[Scintigraphic and quantitative measurement of the gastric wall blood-flow of the dog (author's transl)].

In the examinations presented the gastric wall blood-flow of the dog was measured scintigraphically by using the gamma camera and quantitatively by making use of the microsphere method under different functional conditions. In doing so it became apparent that not only the individual functional stomach regions (corpus-antrum) but as well the individual stomach wall layers (mucosa-muscularis) can show a counter blood flow procedure. The two methods mentioned above have proved to be suitable both for the determination of the gastric wall blood flow in the individual layers and the optical reproduction of the regional blood-flow procedure.

Animals↗
PubMed1978

Practice effects on fractionated response time related to age and activity level.

Two days of practice on simple and choice reaction (RT) and movement time (MT) were studied using 60 males placed into four groups based upon age and physical activity level. Practice effects upon simple and choice RTs were different for young and old groups. Only the two inactive groups improved on simple and choice MT, with greatest improvement occurring on simple MT. Old Actives had true-score variance than the Old Inactives, but much greater than the two young groups. Intraindividual variability was greater for the two older groups even in the absence of practice effects. Results support the claim that a life style or regular physical activity may lessen aging effects upon RT and MT as well as attenuating interindividual variability.

Journal Article↗
PubMed1978

Age, isometric knee extension strength, and fractionated resisted response time.

The relationship of age and a life style of physical activity with isometric knee extension strength and a simple and choice resisted response time was examined in 60 male subjects divided into four equal groups: Old Active, Old Inactive, Young Active, Young Inactive. Each response measure consisted of a visual reaction time followed by a movement to a target. Reaction time was further fractionated into premotor and motor time components. Resistance was applied in reaction time trials via an electromagnet placed below the subject's heel. Although knee extension strength was lower in old groups, the Old Actives were 7.7 kg stronger than Old Inactives. Simple and choice total reaction time for all groups lengthened in the resisted condition due to an increased motor time component. Even though the resistance applied was a fixed 10% of maximum strength the increase in resisted motor time was greatest for the young groups and unrelated to physical activity level.

Adipose Tissue↗
PubMed1977

[Skeletal changes in Down's syndrome. A correlation between radiological and cytogenetic findings (author's transl)].

One hundred and two patients with Down's syndrome aged one day to 17 years were examined radiologically, seven of these repeatedly. Films obtained included the chest in two planes, lateral spine, left hand and pelvis. The following features were noted; the number of paired ribs, ossification centres in the manubrium, height of lumbar vertebral bodies, shortening of the phalanges, bone age and calculation of the acetabula and ilial angle and ilial index. In all patients the chromosomes were examined in order to determine the cytogenetic type. The following features were found to be more common in Down's syndrome than in normals: abnormal ossification of the manubrium (33%), aplasia of the twelfth rib (18%), high lumbar vertebral bodies (50%), brachymesophalangia of the fifth ray (62%) and changes in skeletal maturation (acceleration or retardation in 48%). Changes in the pelvis were typical; with increasing age, the acetabular angle falls and the ilial angle increases. The most striking skeletal changes were found in 84 patients with trisomy 21.

Adolescent↗