John R Barrett

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Gene therapy-induced expression of immunostimulatory molecules at tumor cell level may evoke antitumor immune mechanisms by recruiting and enhancing viability of antigen-processing cells and specific tumoricidal lymphocytes. The antitumor efficacy of a plasmid, coding for granulocyte–macrophage colony-stimulating factor (GM-CSF) and the B7-1 costimulatory(More)
Previous in vivo studies demonstrated that estrogen treatment of male rats allows somatostatin (SRIF) to inhibit PRL release. The objective of this study was to determine whether chronic estrogen (E2) treatment of male rats can induce the conversion of somatotropes to mammosomatotropes. In situ hybridization and reverse hemolytic plaque assay were used to(More)
The concentrations of ovine placental lactogen (oPL) have been determined in maternal plasma, umbilical cord plasma, and allantoic fluid by an homologous radioimmunoassay for oPL which is sensitive to 0-1 ng hormone. Ovine placental lactogen was first detected in maternal plasma at 41-50 days of gestation and reached a peak concentration of 2547 +/- 226(More)
To determine whether human decidua and/or chorion synthesizes and secretes prolactin, explants of decidua obtained at Caesarian section and explants of chorion from the membranes separating dizygotic twins were cultured for periods of up to 6 days. The decidual explants released 366 +/- 37 ng prolactin/100 mg tissue (mean +/- S.D.) during each day in(More)
We have previously described the isolation, cloning, and characterization of a tumorigenic murine fibrosarcoma, designated JBS. Growth of JBS tumors in syngeneic mice initiates an anti-tumor immune response that initially manifests as progressive splenic hyperplasia and an increased proliferative ability in cultured splenocytes. In animals with tumors(More)
In recent studies, we and others showed that autophagy is critical to estrogen receptor positive (ER+) breast cancer cell survival and the development of antiestrogen resistance. Consequently, new approaches are warranted for targeting autophagy in breast cancer cells undergoing antiestrogen therapy. Because crosstalk has been demonstrated between the(More)
The factors that regulate the release of human placental lactogen (hPL) are poorly understood. To determine whether hPL is regulated by a factor(s) in pregnancy serum, placental explants were exposed for up to 9 h to a pool of serum samples from 50 women in the third trimester. In static explant cultures, the addition of the serum (0.6-10.8 mg protein/ml)(More)
To study the effects of calcium on the release of human placental lactogen (hPL), placental explants were exposed to media containing lower or higher concentrations of calcium than normally available to the placenta. Explants exposed for 2 h to calcium-poor medium or medium containing either 2 mM EDTA or 2 mM EGTA released 160, 248, and 253% more hPL,(More)
The role of autophagy in response to ischemic stroke has been confusing with reports that both enhancement and inhibition of autophagy decrease infarct size and improve post-stroke outcomes. We sought to clarify this by comparing pharmacologic modulation of autophagy in two clinically relevant murine models of stroke. We used rapamycin to induce autophagy,(More)
Human decidual explants exposed for 4 h to 150 microM arachidonic acid synthesized and secreted 30.4% (P less than 0.001) and 36.4% (P less than 0.001) less 35S-PRL, respectively, than control explants. Over a 5-h period, the inhibition of PRL secretion was directly proportional to the arachidonic acid concentration at concentrations between 30 and 300(More)