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Biomedical subjects

C W Hall

Publications and source records attributed to C W Hall.

13 recordsLinked to original sources
PubMed1992

Learning styles of LD and NLD ADHD children.

Attention Deficit Hyperactive Disorder (ADHD) children (N = 26) with a learning disability (LD) and without (NLD) were compared on measures of information processing using the Learning Efficiency Test (LET). Method of presentation (visual vs. auditory), order of recall (ordered vs. non-ordered), and memory processes (immediate, short-term, and long-term) were assessed. While both groups showed more difficulty with short-term and long-term memory processes than with immediate memory processes, the ADHD-LD subjects demonstrated more difficulty processing information effectively. Ordered recall was significantly more difficult for both short-term and long-term memory processes than was unordered recall. While both groups demonstrated difficulty with auditory ordered recall under short-term and long-term conditions, the ADHD-LD subjects lost the most information under auditory conditions.

Adolescent↗
PubMed1992

Effects of two treatment techniques on delay and vigilance tasks with attention deficit hyperactive disorder (ADHD) children.

In this study, we examined the effects of two treatment techniques under on-medication and off-medication conditions on the hyperactive behavior patterns of children. Three groups of subjects were compared: a control group, a behavior modification group, and a cognitive training group. The Gordon Diagnostic System (Gordon, McClure, & Post, 1986) was used to assess the subjects at the initial screening, during treatment without medication, and during treatment with medication. The two medication conditions were counterbalanced during the second and third testing sessions. Results showed that when the cognitive intervention was combined with medication, there was a significant improvement in the subjects' ability to delay impulsive responding. However, no significant effects were seen for sustained vigilance for either the behavioral or cognitive groups. Parents rated children in the cognitive group significantly higher than those in the control group.

Attention↗
PubMed1990

Recovery of function in Chinese hamster ovary cell mutants with temperature-sensitive defects in vacuolar acidification.

After 4 h at 41 degrees C, B3853 and M311, temperature-sensitive Chinese hamster ovary cell End1 and End2 mutants, respectively, are pleiotropically defective in endocytosis and trans-Golgi network-associated activities (Roff, C. F., R. Fuchs, I. Mellman, and A. R. Robbins. 1986. J. Cell Biol. 103:2283-2297). We have measured recovery of function after return to the permissive temperature. Based on return of normal transferrin-mediated Fe uptake and sensitivity to diphtheria toxin both mutants had restored endosomal function at 10 h; based on delivery of endocytosed lysosomal enzymes to lysosomes and normal sensitivity to modeccin both had functional late endocytic organelles at 10-12 h; and based on retention of newly synthesized lysosomal enzymes and sialylation of secreted glycoproteins both had functional trans-Golgi network at 6 h. At 10 h, M311 had recovered almost all of its ability to endocytose lysosomal enzymes; B3853 required 30 h to recover fully its ability to endocytose lysosomal enzymes. Slow recovery of mannose 6-phosphate-dependent uptake in B3853 reflected altered trafficking of cation-independent mannose 6-phosphate receptors. Although B3853 had normal amounts of receptor at 6-8 h, it had greatly diminished amounts of receptor at the cell surface. Altered trafficking was also suggested by the finding that B3853 rapidly degraded receptor that had been present before the shift to the nonpermissive temperature.

Animals↗
PubMed1989

Research for ground-water quality management with an emphasis on in situ biorestoration.

It is important to remember that the behavior of contaminants in the subsurface is influenced by chemical and hydrologic parameters as well as biotic considerations, and that a wholistic understanding of these processes will be required for successful ground-water quality management. There is little doubt that vast resources will be devoted to remedial action activities aimed at restoring ground water in coming years. With the average cost of cleaning up a hazardous waste site now approaching five million dollars, the future cost of dealing with existing sources of ground-water contamination will be measured in many billions of dollars and uncalculable hours of effort. Already we can see that, as we begin to understand the processes that control the behavior of pollutants in the subsurface, we can not only reduce these expenditures dramatically, but also assure that the actions taken adequately protect ground water now and in the future.

Bacteria↗
PubMed1976

Skeletal extension development: criteria for future designs.

Experience with an intramedullary skeletal extension and a supracortical extension has been reviewed. Criteria for possible use in future developments have been outlined. Tissue interfacing with the material used in fabricating these devices were briefly discussed, stressing the importance of maintaining the skin's integrity. An artificial tendon, which attempts to bring the external mechanical ankle joint under the direct control of existing skeletal muscles, was described. Three animal models were reviewed and our reasons given for selecting the goat. Preoperative preparations, anesthesia, and the surgical procedures were described in some detail. A tabulation of the procedures done on 52 goats (Table 1) shows little difference between the intramedullary rod and the supracortical devices when only the times in place are compared. However, the supracortical devices showed no bone necrosis and produced only one case of osteomyelitis. With the intramedullary rod, five cases of necrosis and/or osteomyelitis were seen. The cone-shaped supracortical devices are somewhat vulnerable to forces in extension.

Animals↗
PubMed1975

Sleep attacks--apparent relationship to atlantoaxial dislocation.

Sleep attacks, while being characteristic of narcolepsy, have been reported in several metabolic and central nervous system disorders--most of which are refractory to treatment. We have recently treated a 47-year-old man with disabling sleep attacks who was found to have atlantoaxial dislocation. Despite narrowing of the sagittal cervical canal diameter to 12 mm (behind the dens), symptoms of spinal cord compression were mild and intermittent, while signs were absent. Posterior fusion of the C-1 and C-2 vertebrae resulted in relief of symptoms. We suggest that this sleep disorder was a function of impaired efferent control of respiration.

Axons↗
PubMed1975

Development of skin interfacing cannula.

The skin interfacing potential of various velours, felts, foams and rough cast surfaces of some polymers was investigated by bonding these substances to solid core silastic rods using Dow-Corning Medical Adhesive Type A. These dummy cannulae were implanted as skin penetrating rods onto the dorsum of canines, goats, and swine. Vitreous carbon buttons were also investigated as to their potential. Over 200 individual implants were made and some retained in place for 2 yrs. Only the nylon and dacron velours held much promise as a long-term interfacing material. A "growth phenomenon" was observed using the velour material and this, we feel, is related to a permanent marriage between basal cells and adjacent monofilament fibers. Subsequent maturation of these cells carries the monofilament fibers to the surface causing the entire cannula to "grow". Since the maturation rate is apparently slower in humans, it does not detract from their potential application. The maturation rate is also much more rapid on the dorsum than on the ventral surfaces.

Animals↗