A differential deficit in time- versus event-based prospective memory in Parkinson's disease.

The aim of the current study was to clarify the nature and extent of impairment in time- versus event-based prospective memory in Parkinson's disease (PD). Prospective memory is thought to involve cognitive processes that are mediated by prefrontal systems and are executive in nature. Given that individuals with PD frequently show executive dysfunction, it is important to determine whether these individuals may have deficits in prospective memory that could impact daily functions, such as taking medications. Although it has been reported that individuals with PD evidence impairment in prospective memory, it is still unclear whether they show a greater deficit for time- versus event-based cues

A Differential Deficit in Time- Versus Event-Based Prospective Memory in Parkinson\u27s Disease

The aim of the current study was to clarify the nature and extent of impairment in time- versus event-based prospective memory in Parkinson\u27s disease (PD). Prospective memory is thought to involve cognitive processes that are mediated by prefrontal systems and are executive in nature. Given that individuals with PD frequently show executive dysfunction, it is important to determine whether these individuals may have deficits in prospective memory that could impact daily functions, such as taking medications. Although it has been reported that individuals with PD evidence impairment in prospective memory, it is still unclear whether they show a greater deficit for time- versus event-based cues. Method: Fifty-four individuals with PD and 34 demographically similar healthy adults were administered a standardized measure of prospective memory that allows for a direct comparison of time-based and event-based cues. In addition, participants were administered a series of standardized measures of retrospective memory and executive functions. Results: Individuals with PD demonstrated impaired prospective memory performance compared to the healthy adults, with a greater impairment demonstrated for the time-based tasks. Time-based prospective memory performance was moderately correlated with measures of executive functioning, but only the Stroop Neuropsychological Screening Test emerged as a unique predictor in a linear regression. Conclusions: Findings are interpreted within the context of McDaniel and Einstein\u27s (2000) multiprocess theory to suggest that individuals with PD experience particular difficulty executing a future intention when the cue to execute the prescribed intention requires higher levels of executive control. © 2010 American Psychological Association

Synergy of topotecan in combination with vincristine for treatment of pediatric solid tumor xenografts

Topotecan and vincristine were evaluated alone or in combination against 13 independent xenografts and 1 vincristine-resistant derivative, representing childhood neuroblastoma (n = 6), rhabdomyosarcoma (n = 5), or brain tumors (n = 3). Topotecan was given by i.v. bolus on a schedule found previously to be optimal. Drug was administered daily for 5 days on 2 consecutive weeks with cycles repeated every 21 days over a period of 8 weeks. Doses of topotecan ranged from 0.16 to 1.5 mg/kg to simulate clinically achievable topotecan lactone plasma systemic exposures. Vincristine was administered i.v. every 7 days at a fixed dose of 1 mg/kg. Given as a single agent, vincristine induced complete responses (CRs) in all mice bearing two rhabdomyosarcomas (Rh28 and Rh30) and some CRs in Rh12- bearing mice (57%) but relatively few CRs (\u3c29%) in other tumors. As a single agent, topotecan induced CR in a low proportion of tumor lines. A dose- response model with a logit link function was used to investigate whether the combination of topotecan and vincristine resulted in greater than expected responses compared with the activity of the agents when administered alone. Only CR was used to evaluate tumor responses. The combination resulted in significantly greater than expected CRs than individual agents in nine tumor lines (four neuroblastoma, three brain tumors, and two rhabdomyosarcomas). Similar event-free (failure) distributions were shown in SJ-GBM2 glioblastoma xenografts, whether vincristine was administered on day 1 or day 5 of each topotecan course. To determine whether the increased antitumor activity with the combination was attributable to a change in drug disposition, extensive pharmacokinetic studies were performed. However, little or no interaction between these two agents was determined. Toxicity of the combination was marked by prolonged thrombocytopenia and decreased hemoglobin. However, approximately 75 and 80% of the maximum tolerated dose of each single agent, topotecan (1.5 mg/kg) or vincristine (1 mg/kg), could be given in combination, resulting in a combination toxicity index of ~1.5. These results show that the therapeutic effect of combining topotecan with vincristine was greater than additive in most tumor models of childhood solid tumors, and toxicity data suggest that this can be administered to mice with only moderate reduction in the dose levels for each agent

Predictors of psychotropic medication adherence among HIV+ individuals living with bipolar disorder.

ObjectiveHIV infection and bipolar disorder are highly comorbid and associated with frontostriatal disruption, emotional dysregulation, and neurocognitive impairment. Psychiatric and cognitive factors have been linked to antiretroviral nonadherence; however, predictors of psychotropic adherence among HIV+ individuals with psychiatric comorbidities have not been explored. We evaluated predictors of psychotropic adherence among individuals with HIV infection and bipolar disorder.MethodPsychiatric medication adherence of 50 participants with HIV infection and bipolar disorder was tracked for 30 days using Medication Event Monitoring Systems. Participants completed neurocognitive, neuromedical, and psychiatric batteries.ResultsMean psychotropic adherence rate was 78%; 56% of participants achieved ≥90% adherence. Younger age and onset of depressive symptoms, more severe current depressive symptoms, number of previous psychiatric hospitalizations and suicide attempts, poorer neurocognition, and more negative attitudes and self-beliefs toward medications univariably predicted worse psychotropic adherence (p's < .10). A multivariable model demonstrated a combination of current depressive symptoms and more negative attitudes toward medications significantly predicting poorer adherence (R(2 )= 0.27, p < 0.003). Secondary analyses revealed an interaction between neurocognition and mood, such that individuals with HIV infection and bipolar disorder who had greater executive dysfunction and depressive symptoms evidenced the poorest psychotropic adherence (p < 0.001).ConclusionsBoth psychiatric and neurocognitive factors contribute to poorer psychotropic adherence among HIV+ individuals with serious mental illness. Adherence interventions aimed at remediating these factors may be especially fruitful

Individualized texting for adherence building (iTAB): improving antiretroviral dose timing among HIV-infected persons with co-occurring bipolar disorder.

HIV+ persons with co-occurring bipolar disorder (HIV+/BD+) have elevated rates of medication nonadherence. We conducted a 30-day randomized controlled trial of a two-way, text messaging system, iTAB (n = 25), compared to an active comparison (CTRL) (n = 25) to improve antiretroviral (ARV) and psychotropic (PSY) adherence and dose timing. Both groups received medication adherence psychoeducation and daily texts assessing mood. The iTAB group additionally received personalized medication reminder texts. Participants responded to over 90 % of the mood and adherence text messages. Mean adherence, as assessed via electronic monitoring caps, was high and comparable between groups for both ARV (iTAB 86.2 % vs. CTRL 84.8 %; p = 0.95, Cliff's d = 0.01) and PSY (iTAB 78.9 % vs. CTRL 77.3 %; p = 0.43, Cliff's d = -0.13) medications. However, iTAB participants took ARVs significantly closer to their intended dosing time than CTRL participants (iTAB: 27.8 vs. CTRL: 77.0 min from target time; p = 0.02, Cliff's d = 0.37). There was no group difference on PSY dose timing. Text messaging interventions may represent a low-burden approach to improving timeliness of medication-taking behaviors among difficult-to-treat populations. The benefits of improved dose timing for long-term medication adherence require additional investigation