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Biomedical subjects

J Potvin

Publications and source records attributed to J Potvin.

At least 19 recordsLinked to original sources
PubMed2002

Quantification of subcellular glycogen in resting human muscle: granule size, number, and location.

A few qualitative investigations suggested that location of muscle glycogen (G) granules in specific sites may be associated with distinct metabolic roles. Similarly, it has been suggested that the acid-soluble and -insoluble G fractions (macro- and proglycogen, respectively) are different metabolic pools and also could exist as separate entities. We employed a transmission electron microscopic technique to quantify subcellular G particle size, number, and location in human vastus lateralis biopsies of 11 resting men. The intra- and interobserver variability for the various measures was generally <4%. Granule size and number were quantified in subcellular compartments (subsarcolemmal, intra- and intermyofibrillar). Subcellular location was critical: G was more densely concentrated in the subsarcolemmal than in the myofibrillar space, whereas the single-particle volume was greater in the latter. Single-particle diameter ranged from 10 to 44 etam and followed a continuous, normal distribution. This implies that proglycogen is not a distinct entity, but rather that pro- and macroglycogen are divisions of smaller and larger molecules. These results demonstrate a compartmentalized pattern of subcellular G deposition in human skeletal muscle for both the size and density of granules.

Adult↗
PubMed1994

Assessment of risk factors for development of work-related musculoskeletal disorders (RSI).

This paper describes an approach to assessing the exposure to risk factors for the development of work-related chronic musculoskeletal disorders (repetitive strain injuries) of the upper limbs and low back. Instrumentation has been developed that combines a video image of the worker performing the task with superimposed quantitative information on risk factors. A description of the methodology, the rationale for the quantities displayed and workplace examples are presented. Continuous monitoring with both muscle activation and video has been found to be useful for identifying risk factors for both acute and chronic injuries in many workplaces. The approach gives information on chronic low-level loading not easily identified with observational methods. The methods presented give quantified information necessary for exposure measures in epidemiological studies. They also give semi-quantified information useful for identifying risks and justifying changes as well as for presentation to non-technical audiences.

Journal Article↗