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Biomedical subjects

C Duncan

Publications and source records attributed to C Duncan.

At least 109 records · Page 6Linked to original sources

Effect of folic acid by mouth on cerebrospinal fluid homovanillic acid and 5-hydroxyindoleacetic acid concentration.

Administration of 30 mg folic acid by mouth caused a significant fall in cerebrospinal fluid homovanillic acid concentration in 11 subjects. There was no significant change of 5-hydroxyindoleacetic acid concentration. The fall was less marked in five patients on anticonvulsant medication and failed to reach statistical significance. Neither homovanillic acid nor 5-hydroxyindoleacetic acid concentrations changed significantly when 15 mg folic acid was given in divided dosage for one, two, and four weeks. The effect appeared to be related to the height of serum-folate levels reached and to be independent of cerebrospinal fluid-folate levels, which did not change significantly. Possible mechanisms and their potential therapeutic application are discussed.

Administration, Oral↗

Impaired glucose tolerance: a late effect of insulin shock treatment.

Glucose tolerance tests were performed in a group of patients in a mental hospital who had been treated with insulin shock and in a matched control group. Five out of 31 (16%) patients in the insulin-treated group and 1 out of 22 (5%) controls had "diabetic" blood sugar curves. Median blood sugar values were significantly higher at 60 minutes and later in the insulin-treated group, as were mean blood sugar values when the "diabetic" patients were excluded. Small amounts of plasma insulin-binding antibody were found in two insulin-treated patients. In the absence of any other clear-cut explanation, it is suggested that in some patients massive doses of insulin by injection may leave diminished tissue responsiveness to insulin as a long-term after-effect.

Adult↗

Short-latency somatosensory evoked potentials in perinatal asphyxia.

Ten asphyxiated term newborns were studied in the first 6 months of life with median nerve short-latency somatosensory evoked potentials (SLSEP) and followed subsequently to a mean age of 20 months. Results of SLSEP correlated with subsequent outcome in every patient; normal and abnormal infants at subsequent examination were separable on the basis of prior SLSEP, although the severity of later disability could not be inferred from SLSEP.

Asphyxia Neonatorum↗

Characterization of an analphoid, neocentromere-positive inv dup 8p marker chromosome using multiplex whole chromosome and sub-telomere FISH analyses.

A 30-year-old male patient with mild mental retardation was found to have a small supernumerary marker chromosome (SMC) in 90% of his peripheral blood cells and in 100% of his fibroblast cells. Multiplex whole chromosome and sub-telomere FISH analyses were used to determine that this SMC is an inverted duplicated distal chromosome 8p fragment. Although it was negative for alpha-DNA sequences, this marker had a functional kinetochore (neocentromere) demonstrated by a positive signal with a CENP-C antibody. Apparently intact 8p telomeres at the marker's ends were demonstrated by using a telomere repeat FISH probe. The patient's phenotypically normal mother on G-banding analysis had a small marker chromosome in 8% of her peripheral blood cells in two cultures of the first specimen studied. The marker was not seen in any subsequent maternal peripheral blood or fibroblast specimens. Although it was impossible to further characterize the maternal SMC, it was suggested that the mother had the same marker as the one seen in the proband. Inverted duplicated chromosomal fragments are the most frequent type of analphoid markers. Stable inverted duplicated 8p marker chromosomes were previously reported in three other patients. They all apparently occurred de novo and were found to be positive for kinetochore-associated proteins. Evidence for the possible inheritance of an inverted-duplicated, analphoid SMC was not shown to-date. This study also demonstrates a practical, straightforward approach for analphoid marker characterization in clinical laboratory settings, using whole chromosome multiplex and subtelomere-specific FISH analyses. FISH probes for all sub-telomere chromosomal regions are commercially available and the large majority of analphoid marker chromosomes involve telomere regions.

Adult↗