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  • 1
    Electronic Resource
    Electronic Resource
    The control and coordination of one-handed catching: the effect of temporal constraints (1994)
    Springer
    Experimental brain research 101 (1994), S. 314-322 
    Details
    ISSN: 1432-1106
    Keywords: One-handed catching ; Temporal constraints ; Motor control ; Kinematics ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of the experiment was to identify the control mechanisms involved in a goal-directed task by manipulating the temporal constraints. Subjects were required to catch, with one hand, table tennis balls projected by a ball-projection machine under five temporal conditions (ball speed ranged from 5.7 to 9 m/s, giving rise to flight times of 550-350 ms). By means of three-dimensional kinematics analysis the following results were obtained, which are some spatio-temporal adaptations of the catching movement to the increase of temporal constraints: (1) a decrease in movement time, (2) an increase in the straightness of the trajectory of the wrist, and (3) a shift backwards of the place of ball-hand contact while (4) the grasping time was kept constant. Moreover, as a result of increasing temporal constraints, the acceleration phase of the transportation component was kept constant while the deceleration phase was progressively decreased and nearly suppressed. Further, an increased correlation of the initial direction of the transportation component with the initial direction of the ball path was found. These findings show some spatio-temporal adaptations of the catching movement when the time available is manipulated. They also support the contention of a shift in the control mechanisms involved in one-handed catching facing different temporal constraints.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228752
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  • 2
    Electronic Resource
    Electronic Resource
    Habitual physical activity and peak anaerobic power in elderly women (1997)
    Springer
    European journal of applied physiology 76 (1997), S. 81-87 
    Details
    ISSN: 1439-6327
    Keywords: Key words Exercise ; Training ; Cycle ergometer ; Maximal power ; Optimal velocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to investigate the relationship between maximal anaerobic power (P max) and corresponding optimal velocity (V opt) and habitual physical activity (PA) on the one hand and with maximal oxygen consumption (V˙O2max) on the other hand, in elderly women. Twenty-nine community dwelling, healthy women aged 66–82 years participated in the study. PA was evaluated using the Questionnaire d'Activite Physique Saint-Etienne (QAPSE) and expressed using two QAPSE activity indices: mean habitual daily energy expenditure (MHDEE) and daily energy expenditure corresponding to leisure time sports activities (sports activity). The subjects' P max and V opt were measured while they cycled on a friction-loaded non-isokinetic cycle ergometer. P max was expressed relative to body mass [P max/kg(W · kg−1)], and relative to the mass of two quadriceps muscles [P max /Quadr(W·kgQuadr −1)]. A negative relationship between P max/kg (Spearman's r = −0.56; P 〈 0.01), P max/Quadr (r = −0.53; P 〈 0.01) and V opt (r = −0.45; P 〈 0.05) and age was found. P max/kg was positively associated with MHDEE (r = 0.51; P 〈 0.01) and sports activity (r = 0.58; P 〈 0.01), as were P max/Quadr and V opt (r = 0.55; P 〈 0.01 and r = 0.54; P 〈 0.01, respectively). P max/kg, P max/Quadr and V opt correlated positively with V˙O2max. The positive relationship between ergometer measurements and PA indices was similar to that between V˙O2max and PA. P max/kg was, moreover, closely related to V opt (r = 0.77; P 〈 0.001). When a multiple stepwise regression analysis was used to select the variables influencing ergometer measurements, MHDEE contributed significantly to P max/kg variance, whereas sports activity contributed to P max/Quadr and V opt variances. In conclusion, the data from this cross-sectional study suggest that in healthy elderly women habitual PA, and especially leisure time PA, alleviates the decline of the P max of the quadriceps muscles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004210050216
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  • 3
    Electronic Resource
    Electronic Resource
    Peak anaerobic power in elderly men (1997)
    Springer
    European journal of applied physiology 77 (1997), S. 182-188 
    Details
    ISSN: 1439-6327
    Keywords: Key words Exercise ; Training ; Peak anaerobic power ; Physical activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The relationship of maximal anaerobic power (P max) of the quadriceps muscle and corresponding optimal shortening velocity (v opt) with age, habitual physical activity (PA) and maximal oxygen consumption (V˙O2 max ) were assessed in 37 healthy older [71.1 (SD 3.8) years] men and compared to those of 16 young [22.7 (SD 3.4) years] men. The PA was evaluated using a questionnaire. The P max and v opt were measured on a friction loaded non-isokinetic cycle ergometer. The P max was expressed relative to body mass –P max · kg−1, and relative to the mass of the two quadriceps muscles –P max · kgquad−1. The decline of P max · kg−1 from youth to advanced age (8.3% per decade) was greater than the decrease in quadriceps muscle mass (3.8% per decade), in P max · kgquad−1 (5.9% per decade) and in v opt (4.3% per decade). In the older men, a negative relationship of P max · kg−1 (r = −0.33) and P max · kgquad−1 (r = −0.44) with age was found. Ergometer measurements were not correlated with PA activity indices or V˙O2 max , while V˙O2 max was positively associated with PA. In a multiple stepwise regression analysis age was the only variable that contributed significantly to P max · kg−1 and P max · kgquad−1 variances. Our findings indicated that in these healthy elderly men, unlike the fall in V˙O2 max , habitual PA did not attenuate the decline in P max of the quadriceps muscle with age. This finding was different from a previously described relationship in older women and would suggest sex differences in determining P max in healthy older subjects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004210050318
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  • 4
    Electronic Resource
    Electronic Resource
    Muscle function during brief maximal exercise: accurate measurements on a friction-loaded cycle ergometer (1996)
    Springer
    European journal of applied physiology 74 (1996), S. 100-106 
    Details
    ISSN: 1439-6327
    Keywords: Muscle function ; Human ; Maximal power ; Optimal velocity ; Cycle ergometer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A friction loaded cycle ergometer was instrumented with a strain gauge and an incremental encoder to obtain accurate measurement of human mechanical work output during the acceleration phase of a cycling sprint. This device was used to characterise muscle function in a group of 15 well-trained male subjects, asked to perform six short maximal sprints on the cycle against a constant friction load. Friction loads were successively set at 0.25, 0.35, 0.45, 0.55, 0.65 and 0.75 N·kg−1 body mass. Since the sprints were performed from a standing start, and since the acceleration was not restricted, the greatest attention was paid to the measurement of the acceleration balancing load due to flywheel inertia. Instantaneous pedalling velocity (v) and power output (P) were calculated each 5 ms and then averaged over each downstroke period so that each pedal downstroke provided a combination of v, force and P. Since an 8-s acceleration phase was composed of about 21 to 34 pedal downstrokes, this many v-P combinations were obtained amounting to 137–180 v-P combinations for all six friction loads in one individual, over the widest functional range of pedalling velocities (17–214 rpm). Thus, the individual's muscle function was characterised by the v-P relationships obtained during the six acceleration phases of the six sprints. An important finding of the present study was a strong linear relationship between individual optimal velocity (v opt) and individual maximal power output (P max) (n = 15, r = 0.95, P 〈 0.001) which has never been observed before. Since v opt has been demonstrated to be related to human fibre type composition both v opt, P max and their inter-relationship could represent a major feature in characterising muscle function in maximal unrestricted exercise. It is suggested that the present method is well suited to such analyses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376501
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  • 5
    Electronic Resource
    Electronic Resource
    Specific binding of basic fibroblast growth factor to basement membrane-like structures and to purified heparan sulfate proteoglycan of the EHS tumor (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 137 (1988), S. 321-328 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The binding of iodinated basic fibroblast growth factor (bFGF) to low-density heparan sulfate proteoglycan purified from the Engelbreth Holm Swarm (EHS) sarcoma was investigated using different techniques. The tumor clearly contained bFGF, the level being comparable to that found in other tissues such as human or bovine brain. 125I bFGF strongly bound to the basement membrane-like matrix of EHS frozen sections as revealed by autoradiography. Iodinated bFGF bound to purified heparan sulfate proteoglycan but not to laminin or collagen type IV, three components isolated from the same tumor. In contrast, acidic fibroblast growth factor (aFGF) displayed negligible binding to heparan sulfate proteoglycan. Binding of bFGF to frozen sections and to purified proteoglycan could be strongly inhibited by heparin and was displaced by an excess of unlabeled factor and completely suppressed after heparitinase and heparinase treatments. Binding was a function of the salt concentration and was abolished at 0.6 M NaCl. Scatchard analysis indicated the affinity site had a Kd of about 30 nM, a value 10-15 higher than that recently reported by Moscatelli (J. Cell. Physiol., 131:123-130, 1987) in the case of the low-affinity binding sites present on the surface of baby hamster kidney (BHK) cells.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041370216
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  • 6
    Electronic Resource
    Electronic Resource
    Basic fibroblast growth factor expression in human omental microvascular endothelial cells and the effect of phorbol ester (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 144 (1990), S. 151-158 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The human omentum contains a potent, not yet identified angiogenic activity. The omentum is very vascularized. Therefore, we investigated whether human omental microvascular endothelial cells (HOME cells) express the angiogenic peptide basic fibroblast growth factor (bFGF). Cytosol prepared from HOME cells stimulated DNA synthesis in bovine epithelial lens cells (BEL cells). The mitogenic activity could be neutralized by an anti-bFGF antibody. Basic FGF-like material from the HOME cell cytosol was bound onto a heparin-Sepharose column at 0.6 M and was eluted at 3 M NaCl. The 3 M NaCl eluted material reacted with the specific anti-bFGF antibody in an ELISA and stimulated DNA synthesis. It did not react with a specific anti-acidic fibroblast growth factor (aFGF) antibody. Western blotting experiments using the same bFGF antibody showed the presence of a major band of 17 Kd and a doublet of 20-22 Kd. Northern blotting of nonstimulated HOME cells using a specific 1.4 kb bFGF probe showed the presence of 5 molecular species of 6.6, 3.7, 2.2, 2.0, and 1.0kb. No aFGF mRNA was detected with a specific previously characterized 4.04 kb probe. 12-O-tetradecanoylphorbol 13-acetate (TPA) did not influence significantly the expression of bFGF at the protein and mRNA level in HOME cells. Thus, protein kinase C activation by TPA did not appear to modulate significantly the expression of bFGF for that cell type. Contrastingly, human umbilical vein endothelial cells (HUVE cells), which expressed no bFGF and aFGF mRNA at a basal level, were induced to express bFGF but not aFGF mRNA when stimulated by TPA. These results suggest that the described angiogenic activity could be the bFGF-like mitogen contained in HOME cells and that these cells are different from endothelial cells derived from large vessels (HUVE cells) regarding the expression of bFGF.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041440120
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  • 7
    Electronic Resource
    Electronic Resource
    Up-regulation of aFGF expression in quiescent cells is related to cell survival (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 158 (1994), S. 435-443 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Exogenously administrated acidic FGF modulates the proliferation of several cell types, controls cell differentiation, and promotes cell survival. Most cells that are sensitive to exogenous aFGF are also capable of expressing it at very low levels. Thus in order to establish the role of endogenous aFGF as a mitogenic, differentiation, or survival factor, we studied the regulation of aFGF expression by evaluating the level of mRNA by PCR amplification and the concentration of protein by Enzyme Immuno Assay (EIA). In the lens, the amount of aFGF transcripts in nondividing cells of the central epithelium and in the differentiated fiber cells located at the periphery of the lens is similar, suggesting that endogenous aFGF is not involved with lens differentiation. In cultures, depending on the growth conditions, the endogenous aFGF expressed by Bovine Epithelial Lens (BEL) cells is sub ect to modulation. Cells arrested either by contact inhibition or by serum deprivation express more aFGF transcripts and protein than in exponentially growing cells, implying that endogenous aFGF has no mitogenic role under these conditions. In serum-deprived cells, the addition of specific aFGF antisense primers inhibits endogenous aFGF express on and leads to the death of these cells. These results associated with the higher expression of aFGF in nondividing BEL cells, suggesting that, contrary to exogenous aFGF, endogenous aFGF is not a mitogenic factor but a survival factor.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041580307
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