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Biomedical subjects

C W Hall

Publications and source records attributed to C W Hall.

At least 37 records · Page 2Linked to original sources
PubMed1984

Supersensitivity to norepinephrine induced by prenatal exposure to ethanol.

Pregnant random bred mice were treated with ethanol (ETOH) (0.33 g/kg) for 1 or 2 days prior to parturition. When compared to saline controls, ETOH-treated adult males had vasa deferentia that were supersensitive to norepinephrine (NE). Tissues from mice prenatally treated for 1 day with ETOH showed a decreased response to electrical stimulation whereas vas deferens obtained from 2-day-treated ethanol showed no significant difference in the response compared to that of controls. These findings indicate that prenatal exposure to ETOH can influence the subsequent sensitivity of the vas deferens to adrenergic stimulation. These changes appear to reflect effects of ETOH during critical periods.

Animals↗
PubMed1984

Some factors that influence prolonged interfacial continuity.

Bringing a percutaneous implant through the integument with the intentions of leaving it as a functional device for prolonged periods of time has not yet become a reality. If we are ever to achieve prolonged uninfected implants, attention must be directed toward a variety of failure mechanisms. Some of these mechanisms have defied our scrutiny, and our awareness of others are poorly understood. Some of the causes for failure of a percutaneous implant are the forces, either extrinsic or intrinsic, that cause shearing and tearing at the skin-implant interface. Extrinsic forces are defined as those forces applied either to the skin or the implant by the external environment. Intrinsic forces are those that have to do directly or indirectly with the body's growth and cell maturation, such as the retraction of maturing scar tissue and the surface migration of squamous epithelium. An intact skin-implant interface is important to attain in order to close the portal which might allow microbial invasion. The integument must remain intact, since a suppurative wound makes the implant's removal mandatory.

Animals↗
PubMed1982

Administration of iduronate sulfatase by plasma exchange to patients with the Hunter syndrome: a clinical study.

The Hunter syndrome (MPS II) is the only mucopolysaccharidosis in which there is appreciable activity of the deficient enzyme in normal plasma. We performed enzyme-replacement treatment by plasma exchange in five Hunter syndrome children. Carefully monitoring the cardiovascular status, we administered monthly single plasma volume exchanges for a 3 to 8 mo period. The results indicate a substantial gain of enzyme activity, persisting with a t50% = 19 +/- 5 hr. The maximal level and persistence of increased enzyme activity did not change after repeated exchanges, suggesting that immune responses were not elicited. Despite this, no demonstrable clinical benefit was apparent when the study group was compared with an age-matched control group of Hunter syndrome patients.

Adolescent↗
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↗