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Biomedical subjects

L C Hall

Publications and source records attributed to L C Hall.

8 recordsLinked to original sources
PubMed1997

Cervical myelopathy associated with intracranial dural arteriovenous fistula: MR findings before and after treatment.

The MR findings in three patients with intracranial dural arteriovenous fistula associated with cervical myelopathy are described. The MR appearance of an enlarged cord with associated abnormal signal and enhancement is nonspecific and can simulate tumor, demyelination, and inflammation. Enlarged perimedullary vessels may not always be identifiable, but if present, should suggest the presence of an arteriovenous fistula.

Aged↗
PubMed1989

Pharmacokinetics for regulatory risk analysis: the case of 1,1,1-trichloroethane (methyl chloroform).

A methodology for using physiologically based pharmacokinetic (PBPK) models to derive predicted safe concentrations of noncarcinogens in drinking water for humans based on experimentally determined no observed adverse effect levels (NOAELs) in animals is presented and applied to the case of 1,1,1-trichloroethane (methyl chloroform, MC). For each toxic endpoint and lowest corresponding NOAEL identified for MC, we considered a set of toxicologically plausible options regarding the presumed toxic agent and the metric for effective dose to target tissue. A four-compartment PBPK model for rodents was used to estimate corresponding effective doses to the animals used to obtain the experimental NOAELs. A five-compartment PBPK model was then applied, in conjunction with a multiroute (inhalation, ingestion and dermal) human-exposure scenario, to calculate alternative concentrations of MC in drinking water predicted to result in corresponding effective doses to the same target tissues in humans. In the case of MC, the PBPK approach to interspecies and interroute extrapolation of toxicity data resulted in lower drinking water concentrations predicted to be nontoxic to humans than corresponding concentrations obtained using a traditional method for determining safe levels.

Animals↗
PubMed1988

Age, sex, and contact with elderly adults as predictors of knowledge about psychological aging.

Using an instrument developed in the United States to assess students' knowledge of mental health in old age, the present study tested 179 Australian undergraduates who varied in age, sex, and the frequency of their contact with aged people at home, at work, and in the neighborhood. As predicted, women scored higher than men and scores rose with age and with contact when age was partialed out. Unexpectedly, Australian students averaged two more items correct than the American students for whom the test was developed. Implications for teaching are considered.

Adult↗
PubMed1979

Comprehension of transitive and intransitive phrases by autistic, retarded, and normal children.

Autistic children were compared with retarded and normal control groups in a verbal comprehension task. Subjects were asked to select from four pictures the one that illustrated a two-word intransitive or three-word transitive phrase which was described verbally. Distractor pictures differed from the target picture by one, two, or all three features. Autistic children were poorer in performance than the control groups; however, the hierarchy of difficulty of discrimination was common to all three groups, with transitive phrases more difficult than intransitive phrases. Word type did not affect comprehension for the autistic children, although control children evidenced most difficulty with the verb or middle word. Results are interpreted as supporting the hypothesis that a severe and global language disorder is characteristic of autism.

Adolescent↗
PubMedDate not supplied

Fractured submandibular gland: CT findings.

A patient presented 12 h following trauma with a slowly expanding neck mass. Both CT and sialographic evaluation demonstrated a fracture of the left submandibular gland.

Adult↗