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Biomedical subjects

L E Holt

Publications and source records attributed to L E Holt.

At least 19 recordsLinked to original sources
PubMed1995

P300 topography in Alzheimer's disease.

This study assessed whether P300 scalp topography distinguished subjects with Alzheimer's disease (AD) from controls. Specifically, it was predicted that the AD group would show maximum P300 amplitude over frontal areas and the largest P300 reduction over parietal and left hemisphere areas. These hypotheses were tested using a standard auditory oddball paradigm to compare 26 AD subjects and 26 controls matched on age, sex, handedness, and education. P300 was measured at frontal, central, parietal, and occipital sites over left and right hemispheres and along the midline. Results revealed that the distribution of P300 was different for the two groups such that the controls manifested a maximum over parietal areas, whereas the AD subjects showed a maximum at frontal sites with the largest reductions in P300 over parietal areas. No hemispheric differences in P300 were found. These results are consistent with the hypothesis that P300 represents the activity of multiple neural generators that are differentially disrupted by the disease process.

Adult↗
PubMed1995

Hemodynamics during a machine-aided flexibility protocol.

Heart rates and systolic and diastolic blood pressures of 15 subjects were measured before, during, and after a series of four proprioceptive neuromuscular facilitation (PNF) flexibility exercises. The protocol for the study involved the use of two new machines, one designed to increase flexibility of the erector spinae, the other the hamstrings. Each machine provided constant feedback of isometric force, angular displacements, time of contraction, repetitions, and other exercise variables. Each bout of exercise involved an isometric contraction of the lengthened agonist muscle group (12 sec) followed by a concentric contraction of its antagonist in order to place the body part in a more stretched position. Hemodynamic measurements were determined at both a perceived maximal voluntary isometric contraction (MVIC) and at 50% MVIC. Significant increases in hemodynamic factors were observed when exercise measures were compared to pre- and postexercise (resting) values. Higher values, though not significantly so, were found at MVIC than at 50% MVIC on both machines. All values were well within the guidelines of the American College of Sports Medicine.

Adolescent↗
PubMed1995

The etiology of paddler's shoulder.

Training methods used in competitive flatwater paddling often lead to a common pattern of soft tissue injuries that affect the upper limb. Of particular frequency is paddler's shoulder, a condition that can become chronic and may result in permanent damage. The authors suggest that the cumulative effect of poorly structured resistance training initiates the deteriorative process and together with the repetitiveness of on-water training results in the pathologies referred to as paddler's shoulder.

Athletic Injuries↗
PubMed1994

In vivo evaluation of brain iron in Alzheimer's disease and normal subjects using MRI.

Magnetic resonance imaging (MRI) can measure transverse relaxation rate (R2) of tissues. Although R2 is increased by tissue iron levels, R2 is not a specific measure of iron. A new method, based on the fact that ferritin (the primary tissue iron storage protein) affects R2 in a field-dependent manner, can quantify tissue iron with specificity by measuring the Field Dependent R2 Increase (FDRI). Using the FDRI method, we compared brain iron stores in frontal white matter, caudate nucleus, putamen, and globus pallidus of five male patients with Alzheimer disease (AD) and eight age and gender-matched normal controls. FDRI values were significantly higher among AD patients in the caudate and globus pallidus. The data suggest that AD may involve disturbances in brain iron metabolism and that the involvement of iron in the pathophysiology of age-related neurodegenerative disorders can be investigated in vivo using MRI.

Aged↗
PubMed1980

A comparison of selected stop, reverse and start (SRS) techniques in ice hockey.

The purpose of this study was to compare three stop, reverse, and start (SRS) techniques used in the game of ice hockey. Six S's from four levels of competition were instructed in the execution of three skills, then timed over a specified course performing each method. Additionally, selected S's within each group were filmed from frontal and lateral perspectives while performing the tests. A biomechanical analysis of all films was conducted. Both statistical and biomechanical analyses showed a superiority of the "feet parallel, thrust and glide" technique over both techniques employing the "cross over." Conclusion was that the former method should be included in the instructional and competitive programs in Ice Hockey.

Biomechanical Phenomena↗