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J Perdue

Publications and source records attributed to J Perdue.

7 recordsLinked to original sources
PubMed1990

Insulin-like growth factor receptor expression and function in human breast cancer.

The insulin-like growth factors IGF-I and IGF-II are potent mitogens for several breast tumor cell lines in culture. Additionally, both IGF-I and IGF-II mRNAs are easily detected in the majority of breast tumor specimens examined, while no breast cancer epithelial cell lines we have studied express authentic IGF-I mRNA, and few lines express IGF-II mRNA. Although receptors for insulin, IGF-I, and IGF-II have been described, there is significant cross-reactivity between the various receptors and ligands in the insulin/insulin-like growth factor family, and it is not clear which receptor or receptors are responsible for the biological effects of these growth factors in this system. Using an RNase protection assay, we examined breast tumor specimens and breast cancer epithelial cell lines for expression of mRNA encoding the type I and type II IGF receptors as well as the insulin receptor. Virtually all of the specimens examined expressed mRNA for all three receptors. We then examined estrogen-dependent MCF-7 cells for the mitogenic effects of IGF-I and II in the presence of antibodies to both the type I and type II receptors. alpha IR-3, a monoclonal antibody which blocks the type I receptor, abolished the mitogenic effects of both IGF-I and IGF-II. It did not, however, block the mitogenic effects of insulin. We conclude that type I and type II IGF receptors are ubiquitously expressed in breast cancer, and our experiments with MCF-7 cells suggest the mitogenic effects of both IGF-I and IGF-II are mediated via the type I IGF receptor.

Blotting, Northern↗
PubMed1983

Cholera on a Gulf Coast oil rig.

A single case of severe diarrhea on a floating Texas oil rig was followed two days later by what proved to be the largest outbreak of cholera in the United States in over a century. After isolation of toxigenic Vibrio cholerae El Tor Inaba of the typical United States phage type from the index patient's stool, the ensuing investigation detected 14 additional cases of cholera and one asymptomatic infection serologically. Infection was associated with eating rice on the oil rig on a particular day (P = 0.03) when an open valve permitted the rig's drinking-water system to be contaminated by canal water containing sewage (including that from the index patient) discharged from the rig. The rice had been rinsed in the contaminated water after cooking, and before being served it had been maintained at a temperature that allows V. cholerae 01 to multiply. Toxigenic V. cholerae 01 is persisting in the United States, and large common-source outbreaks of cholera can occur if proper sanitation is not maintained.

Adult↗
PubMed1982

Age differences in information acquisition strategies.

Age differences in information acquisition strategies were investigated by means of a visual 20-questions game. An optimal information acquisition strategy was made increasingly apparent across three experimental trials through strategy cues and demonstration. Three primary measures of information acquisition efficiency were defined and used to assess how closely the participants in three age groups (45-50 years, 60-65 years, 75-80 years) approximated ideal solution strategy. All measures indicate significant age group differences in the efficiency with which information was acquired, with the 45-50 year-old group scoring highest and the 75-80 year-old group scoring lowest. All age groups improved significantly across the three trials. The problem solving efficiency of the 60-65 year-old group was similar to that of the 45-50 year-old group, but the 75-80 year-old group scored significantly lower on performance measures than did the two younger groups combined. When a categorical search strategy was adopted, the oldest participants improved significantly; however, the age differences remained.

Aged↗