Folate exacerbates the effects of ethanol on peripubertal mouse mammary gland development.

Alcohol consumption is linked with increased breast cancer risk in women, even at low levels of ingestion. The proposed mechanisms whereby ethanol exerts its effects include decreased folate levels resulting in diminished DNA synthesis and repair, and/or acetaldehyde-generated DNA damage. Based on these proposed mechanisms, we hypothesized that ethanol would have increased deleterious effects during periods of rapid mammary gland epithelial proliferation, such as peripuberty, and that folate deficiency alone might mimic and/or exacerbate the effects of ethanol. To test this hypothesis, weight-matched 28-35 day old CD2F1 female mice were pair-fed liquid diets ±3.2% ethanol, ±0.1% folate for 4 weeks. Folate status was confirmed by assay of liver and kidney tissues. In folate deficient mice, no significant ethanol-induced changes to the mammary gland were observed. Folate replete mice fed ethanol had an increased number of ducts per section, due to an increased number of terminal short branches. Serum estrogen levels were increased by ethanol, but only in folate replete mice. These results demonstrate that folate deficiency alone does not mimic the effects of ethanol, and that folate deficiency in the presence of ethanol blocks proliferative effects of ethanol on the mammary ductal tree.

Differential pharmacodynamic effects of paclitaxel formulations in an intracranial rat brain tumor model.

Nano- and microparticulate carriers can exert a beneficial impact on the pharmacodynamics of anticancer agents. To investigate the relationships between carrier and antitumor pharmacodynamics, paclitaxel incorporated in liposomes (L-pac) was compared with the clinical standard formulated in Cremophor-EL/ethanol (Cre-pac) in a rat model of advanced primary brain cancer. Three maximum-tolerated-dose regimens given by intravenous administration were investigated: 50 mg/kg on day 8 (d8) after implantation of 9L gliosarcoma tumors; 40 mg/kg on d8 and d15; 20 mg/kg on d8, d11, and d15. Body weight change and neutropenia were assessed as pharmacodynamic markers of toxicity. The pharmacodynamic markers of antitumor efficacy were increase in lifespan (ILS) and tumor volume progression, measured noninvasively by magnetic resonance imaging. At equivalent doses, neutropenia was similar for both formulations, but weight loss was more severe for Cre-pac. No regimen of Cre-pac extended survival, whereas L-pac at 40 mg/kg x2 doses was well tolerated and mediated 26% ILS (p < 0.0002) compared with controls. L-pac at a lower cumulative dose (20 mg/kg x3) was even more effective (40% ILS; p < 0.0001). In striking contrast, the identical regimen of Cre-pac was lethal. Development of a novel semimechanistic pharmacodynamic model permitted quantitative hypothesis testing with the tumor volume progression data, and suggested the existence of a transient treatment effect that was consistent with sensitization or "priming" of tumors by more frequent L-pac dosing schedules. Therefore, improved antitumor responses of carrier-based paclitaxel formulations can arise both from dose escalation, because of reduced toxicity, and from novel carrier-mediated alterations of antitumor pharmacodynamic effects.

An educational intervention on organ and tissue donation for first-year medical students.

CONTEXT: Medical students and medical professionals have knowledge deficits related to organ and tissue transplantation. OBJECTIVE: To implement and evaluate a medical education intervention on organ and tissue donation designed for first-year medical students. STUDY DESIGN: Independent sample pretest and posttest design. SETTING AND PARTICIPANTS: First-year medical students attending University at Buffalo School of Medicine during fall 2005 and fall 2006 terms. INTERVENTION: A 1-hour lecture on the background of organ donation, donor eligibility (eg, living vs deceased donation), policies and roles during transplantation (eg, role of physician and organ procurement organization), and the organ-matching process. After the lecture, students participated in a small-group interaction that used standardized patients who role-played 1 of 2 scenarios designed to test students' knowledge and communication about organ and tissue donation. OUTCOME MEASURES: Knowledge, self-efficacy, family discussion, and enrollment into state organ and tissue registry. RESULTS: Significant increases from pretest to posttest in medical students' knowledge, self-efficacy, and family notification of donation intentions were found. The intervention was successful in increasing students' knowledge and awareness about organ and tissue donation. Future research should implement and evaluate a course-long curriculum on donation.

Life and death decisions: using school-based health education to facilitate family discussion about organ and tissue donation.

Public education that encourages family discussions about organ and tissue donation can enhance understanding, facilitate a donor's wishes and increase the numbers of donations. Action research methods were used to explore the impact of a student-initiated family discussion about donation. Most discussions were positive; only 7% middle school and 4% high school participants described them as "terrible." "Getting it started" was the most difficult. High school students felt "very" or "somewhat" prepared, whereas middle school students only felt "somewhat prepared". Guided family discussions ensure that families have accurate information about donation and an opportunity to talk about end-of-life choices in a non-crisis situation.

The effect of proteasome inhibitors on mammalian erythroid terminal differentiation.

OBJECTIVES: Murine erythroblasts infected with the anemia-inducing strain of Friend virus (FVA cells) terminally differentiate to the reticulocyte stage after 48 hours of culture in vitro in response to erythropoietin (EPO). The objective of this study was to determine the possible role of proteasome-mediated proteolysis during the terminal differentiation of FVA cells. MATERIALS AND METHODS: The proteasome inhibitors MG132 and lactacystin were used to perturb the normal function of proteasomes during terminal differentiation. Effects of proteasome inhibitors on terminal differentiation were quantitated by evaluation of cellular morphology after benzidine staining and by Western blot analyses. RESULTS: Treatment of EPO-stimulated FVA cells with lactacystin or MG132 at later periods of culture increased accumulations of nuclear and cytosolic ubiquitinated proteins and decreased nuclear extrusion to less than 40% of controls. CONCLUSIONS: Our results suggest that the proteasomal degradation of ubiquitinated proteins plays an important role in the enucleation of mammalian erythroblasts.