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S Denis

Publications and source records attributed to S Denis.

7 recordsLinked to original sources
PubMed1992

Characteristics and subcellular localization of pristanoyl-CoA synthetase in rat liver.

We have investigated the activation of pristanic acid to its CoA-ester in rat liver. The results show that peroxisomes, mitochondria as well as microsomes contain pristanoyl-CoA synthetase activity. On the basis of competition experiments and immunoprecipitation studies using antibodies raised against rat liver microsomal long-chain fatty acyl-CoA synthetase (EC 6.2.1.3) we conclude that pristanic acid is activated by the same enzyme which activates long-chain fatty acids, i.e., long-chain fatty acyl-CoA synthetase.

Animals↗
PubMed1992

Identification of pristanoyl-CoA oxidase as a distinct, clofibrate non-inducible enzyme in rat liver peroxisomes.

In this paper we describe the identification of pristanoyl-CoA oxidase activity in rat liver peroxisomes. This activity was not stimulated by clofibrate feeding. Furthermore, the activity was found in multiple tissues. These results show that pristanoyl-CoA oxidase is different from any of the known oxidases which include a clofibrate-inducible acyl-CoA oxidase and the recently identified cholestanoyl-CoA oxidase. Gelfiltration and chromatofocusing experiments provide conclusive evidence that we are dealing with a novel acyl-CoA oxidase with a unique function in peroxisomal beta-oxidation.

Animals↗
PubMed1992

Identification of superoxide dismutase in rat liver peroxisomes.

In this paper we have investigated whether or not superoxide dismutase is localized in peroxisomes from rat liver. Using an improved method to prepare peroxisomes from clofibrate induced rat livers, we identified superoxide dismutase activity in peroxisomes. This activity was found to be predominantly of the copper-zinc type. The finding of superoxide dismutase activity in peroxisomes makes sense since peroxisomes also contain superoxide generating enzyme activities such as xanthine oxidase.

Animals↗
PubMed1991

Sex differences and effects of aging on visuomotor coordination.

The purpose of this study was to examine the effects of aging on men and women in processing information required to reproduce direction and distance on a visuomotor task. Subjects (45 men and 45 women) selected from three age groups (25-34 yr., 45-54 yr., 65-74 yr.) were required to estimate blindly the exact criterion location of a target-point they had identified under one of the following conditions: visual, kinesthetic, and visuokinesthetic. Errors in direction (degrees) and in distance (cm) were recorded. The analysis of the total variability in responding (E) indicated that the women of the 65- to 74-yr. age group were significantly less accurate in estimating distance than were the men of the two older age groups (45 to 54 yr., 65 to 74 yr.) and less accurate than were the women of the 25- to 34-yr. age group. No significant differences in estimating distance were found among the three age groups of men. No significant differences for direction were found between men and women.

Adult↗
PubMed1991

[Spatial representation of a two-dimensional pattern].

The purpose of this study was (a) to determine if vision and kinesthesis contribute differentially to the coding of a specific two-dimensional pattern and (b) to identify the effect of repetition on the spatial representation of this pattern. The reproductions of a specific pattern presented visually were compared with those of a pattern presented kinesthetically. The results showed that vision and kinesthesis had contributed equally to the coding of the directional components of the pattern. However, there was dominance of visual information over kinesthetic information when coding the distance between the intersecting points of the pattern, especially at the beginning of the process. Generally speaking, the visual or kinesthetic repetition, or both, have increased favourably the precision with which a specific pattern was reproduced in distance and direction.

Adolescent↗