Reversal of cocaine-induced planarian behavior by parthenolide and related sesquiterpene lactones

Here we report the prevention and reversal of cocaine-induced behaviors in planarian worms by parthenolide and two related cyclic sesquiterpene lactones (SL), costunolide and santonin. Using established protocols, we studied two cocaine-induced behavioral effects in planaria; the induction of motility decrease and the induction of C-like hyperkinesia. Cocaine, parthenolide, costunolide, santonin, and a lactone-less cyclic sesquiterpene, beta-eudesmol, decreased planarian motility in a concentration-dependent manner. Only cocaine induced C-like hyperkinesia. At concentrations that did not show any motility decrease, parthenolide, costunolide and santonin, but not beta-eudesmol, significantly reduced the cocaine-induced motility decrease and C-like hyperkinesia, in a concentration-dependent manner. Furthermore, parthenolide, costunolide and santonin were able to rescue planaria from C-like hyperkinesia, after the worms were exposed to cocaine. Conversely, cocaine at a concentration that did not show any measurable effects (10 microM), was able to alleviate the SL-, but not the beta-eudesmol-induced motility decrease. Liquid Chromatography/Mass Spectrometry experiments demonstrated that cocaine does not interact directly with any of the cyclic sesquiterpenoids, which suggests specific biochemical targets for these compounds in planarians. Our data suggests a common binding site for cocaine and the sesquiterpene lactones in planarians.     

Low quality of dying and death in patients with septic shock as perceived by nurses and resident physicians

Septic shock is a disease with both high prevalence and mortality. Few studies have evaluated the quality of dying and death (QODD) in patients with septic shock. The authors compared the QODD of patients who died of septic shock versus other causes. They prospectively collected QODD surveys from nurses and residents caring for 196 patients who died in the medical intensive care unit (ICU) at an urban, university hospital. Patients were included in the analysis if either a nurse or resident returned a survey. Chart review established cause of death. The authors compared total QODD scores (on a scale of 0–100) and a single-item score (QODD-1; on a scale of 0–10) of patients who died of septic shock versus other causes. Survey response rates were 59% (n = 155) for residents and 49% (n = 129) for nurses. Nurses rated patients as having lower total QODD and QODD-1 scores for septic (Δ 7.5 points, p = 0.03, and 0.9 points, p = 0.05, respectively). Residents rated septic patients with lower QODD-1 scores than nonseptic patients (Δ 0.8 points, p = 0.03). This study shows that nurses rate patients with septic shock as having lower QODD than patients dying of other causes. These findings are important for clinicians who counsel families of patients dying of septic shock.     

Simple options for improving signal detection in antidepressant clinical trials

Objective: Previous experience with antidepressant studies highlight the difficulties in discriminating an effective drug from placebo. In hopes of improving signal detection, three easy-to-implement methodologies were employed during the development of a recently approved antidepressant. Experimental Design: Results from alternative and traditional methods could be compared directly because most studies employed both methods. This database included 11 double-blind, placebo-controlled trials (some with multiple dose arms and/or active comparators) yielding 22 treatment arms of antidepressants at or above the minimally effective dose noted in their U.S. labels. Principal Observations: Results agreed with the previous evidence showing that the performance of a likelihood-based, mixed-effects model repeated measures (MMRM) analysis was superior to that of analysis of covariance with missing values imputed using the last observation carried forward (LOCF) approach; MMRM correctly identified drug as superior to placebo in 14/22 (63.6%) comparisons versus 11/22 (50.0%) for LOCF. In agreement with previous studies, use of subscales of the Hamilton Depression Rating scale (HAMD) improved signal detection compared to the HAMD total score. Using MMRM with HAMD subscales correctly identified drug as superior to placebo in up to 17/22 (77.3%) comparisons. Excluding double-blind, placebo lead-in responders did not increase the frequency of correctly identifying drug-versus-placebo differences. Conclusions: The 22 drug-versus-placebo comparisons in this report offer a small amount of evidence and therefore may not be convincing on their own, although results do agree with previous research. Researchers may be able to take advantage of these easy-to-implement methods while we wait for further improvements in other areas.     

Adeno-associated virus type 2 infection activates caspase dependent and independent apoptosis in multiple breast cancer lines but not in normal mammary epithelial cells

Background

In normal cells proliferation and apoptosis are tightly regulated, whereas in tumor cells the balance is shifted in favor of increased proliferation and reduced apoptosis. Anticancer agents mediate tumor cell death via targeting multiple pathways of programmed cell death. We have reported that the non-pathogenic, tumor suppressive Adeno-Associated Virus Type 2 (AAV2) induces apoptosis in Human Papillomavirus (HPV) positive cervical cancer cells, but not in normal keratinocytes. In the current study, we examined the potential of AAV2 to inhibit proliferation of MCF-7 and MDA-MB-468 (both weakly invasive), as well as MDA-MB-231 (highly invasive) human breast cancer derived cell lines. As controls, we used normal human mammary epithelial cells (nHMECs) isolated from tissue biopsies of patients undergoing breast reduction surgery.

Results

AAV2 infected MCF-7 line underwent caspase-independent, and MDA-MB-468 and MDA-MB-231 cell lines underwent caspase-dependent apoptosis. Death of MDA-MB-468 cells was marked by caspase-9 activation, whereas death of MDA-MB-231 cells was marked by activation of both caspase-8 and caspase-9, and resembled a mixture of apoptotic and necrotic cell death. Cellular demise was correlated with the ability of AAV2 to productively infect and differentially express AAV2 non-structural proteins: Rep78, Rep68 and Rep40, dependent on the cell line. Cell death in the MCF-7 and MDA-MB-231 lines coincided with increased S phase entry, whereas the MDA-MB-468 cells increasingly entered into G2. AAV2 infection led to decreased cell viability which correlated with increased expression of proliferation markers c-Myc and Ki-67. In contrast, nHMECs that were infected with AAV2 failed to establish productive infection or undergo apoptosis.

Conclusion

AAV2 regulated enrichment of cell cycle check-point functions in G1/S, S and G2 phases could create a favorable environment for Rep protein expression. Inherent Rep associated endonuclease activity and AAV2 genomic hair-pin ends have the potential to induce a cellular DNA damage response, which could act in tandem with c-Myc regulated/sensitized apoptosis induction. In contrast, failure of AAV2 to productively infect nHMECs could be clinically advantageous. Identifying the molecular mechanisms of AAV2 targeted cell cycle regulation of death inducing signals could be harnessed for developing novel therapeutics for weakly invasive as well as aggressive breast cancer types.