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Biomedical subjects

B B Walker

Publications and source records attributed to B B Walker.

10 recordsLinked to original sources
PubMed1990

Scapular dislocation (locked scapula).

We report the case of a 19-year-old woman who presented to the emergency department with pain and inability to move her right shoulder after falling backwards and striking it on a cart. Radiographs of the shoulder revealed a dislocated scapula. Closed reduction in the ED was successful. This rare case of scapular dislocation serves to emphasize that a heightened awareness for this injury is necessary if it is to be recognized and treated appropriately. Its treatment and prognosis are reviewed.

Adult↗
PubMed1979

Influences of an analog of the neuropeptide ACTH 4--9 on mentally retarded adults.

In a double-blind procedure, 24 mentally retarded adults received 0 mg, 5mg, or 20 mg of an analog of the neuropeptide ACTH 4--9. Following treatment with peptide, the subjects were given the Trails B Test (from the Halstead-Reitan Neuropsychological Battery), the Peabody Picture Vocabulary test, the Benton Visual Retention Test, a concept-formation task, and a standard orienting sequence. The results of the behavioral tests suggested that attentional processes were enhanced in subjects treated with the peptide. The present study, in conjunction with another investigation using the neuropeptide ACTH/MSH 4--10 (Sandman, George, Walker, Nolan & Kastin, 1976), indicates that attentional deficits in mentally retarded adults, traditionally assumed to be irreversible, may be influenced by treatment with fragments of the neuropeptides ACTH and MSH.

Adrenocorticotropic Hormone↗
PubMed1979

Human visual evoked responses are related to heart rate.

The purpose of the present experiment was to determine the relation between changes in heart rate and averaged evoked potentials. Sixteen male subjects with variable heart rates received 50 flashes of light during fast heart beats, 50 during slow heart beats, and 50 during midrange heart rate level. Evoked responses were recorded from the scalp overlying the right and left occipital lobes. Heart rate, respiration, eye movements, and cephalic blood flow were also recorded. The results indicated that spontaneous changes in heart rate are related to changes in visual evoked responses and that this relation differs for the two cerebral hemispheres. Furthermore, cephalic pulse amplitude was largest following slow heart beats and smallest following fast heart beats, which suggests that changes in heart rate are related to changes in cerebrovascular as well as electrocortical activity. The results are discussed in terms of formulations derived from behavioral studies regarding the relation between cardiovascular activity and attentional processes.

Adolescent↗
PubMed1978

Voluntary control of electrogastric activity.

The tonic component of the electrogastrogram (EGG) has been shown to differentiate duodenal ulcer patients from healthy individuals (15). It has therefore been of considerable interest to investigate the possibility that individuals can learn to modify electrogastric activity. Using a discriminative conditioning paradigm with analogue feedback (Experiment I), subjects were generally unsuccessful at controlling tonic EGG activity. However, when the conditioning paradigm was altered (Experiment II) it was clear that subjects were able to modify specific electrogastric changes. In addition to EGG, heart rate, respiration, abdominal muscle activity, and digital blood flow were measured in order to assess the physiological concomitants of learned control of gastrointestinal activity. Subjects who evidenced discriminative control also showed the least amount of abdominal muscle activity and reported being the most relaxed. The results of these studies suggest that exploration of the physiological processes underlying the electrical activity of the gastrointestinal system and the ability of individuals to modify this activity may lead to significant clinical and theoretical advances.

Abdominal Muscles↗
PubMed1976

Neuropeptide MSH/ACTH 4-10 enhances attention in the mentally retarded.

Twenty adult mentally retarded men were randomly assigned to receive MSH/ACTH 4-10 or a vehicle control solution in a double blind procedure. After an intravenous injection the subjects were presented with an orienting sequence and a series of behavioral tests. Treatment with the peptide resulted in a significant decelerative heart rate response during the test stimulus of the orienting sequence. Improved performance of the intradimensional and extradimensional shift of a visual discrimination procedure was significant for subjects receiving MSH/ACTH 4-10. The pattern of response on the subproblem analysis of the extradimensional shift reflected greater dimensional attention in the subjects treated with the peptide. Attentive subjects given MSH/ACTH 4-10 evidenced significant improvement on a rhythm matching test, a test of spatial localization and a visual retention test. The data were interpreted as indicating that the peptide resulted in improved attention of stimulus processing. It was speculated that MSH/ACTH 4-10 may be unquely coded for perceptor/attentional functioning and may be useful as a treatment for disorders of attention.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

ACTH 4-9 effects on the human visual event-related potential.

Three oral doses (5, 10 and 20 mg) of an analog of ACTH 4-9 were compared with a vehicle control and d-amphetamine (10 mg). In a double-blind procedure, five men and five women were tested at weekly intervals with each treatment. In each session, four visual event-related potentials (ERPs) were recorded at hourly intervals. Visual ERPs were averaged from the electroencephalogram recorded from the left and right hemisphere. Dosage, time after administration, hemisphere of the brain and sex of the subject influenced the ERP. The ACTH 4-9 analog decreased amplitude of P100 but increased integrated activity of the ERP. This effect peaked at 60 minutes then "recovered." The effects of the peptide were more pronounced with doses of 5 and 10 mg, in the right hemisphere of men and in the left hemisphere of women. The findings indicated that the ACTH 4-9 analog influenced components of ERP commonly related to the perceptual/attentional state of the organism in a sexually dimorphic manner.

Adrenocorticotropic Hormone↗