Effects of the D1 Dopamine Receptor Agonist Dihydrexidine (DAR-0100A) on Working Memory in Schizotypal Personality Disorder

Pharmacological enhancement of prefrontal D₁ dopamine receptor function remains a promising therapeutic approach to ameliorate schizophrenia-spectrum working memory deficits, but has yet to be rigorously evaluated clinically. This proof-of-principle study sought to determine whether the active enantiomer of the selective and full D₁ receptor agonist dihydrexidine (DAR-0100A) could attenuate working memory impairments in unmedicated patients with schizotypal personality disorder (SPD). We performed a randomized, double-blind, placebo-controlled trial of DAR-0100A (15 mg/150 ml of normal saline administered intravenously over 30 min) in medication-free patients with SPD (n=16) who met the criteria for cognitive impairment (ie, scoring below the 25th percentile on tests of working memory). We employed two measures of verbal working memory that are salient to schizophrenia-spectrum cognitive deficits, and that clinical data implicate as being associated with prefrontal D₁ availability: (1) the Paced Auditory Serial Addition Test (PASAT); and (2) the N-back test (ratio of 2-back:0-back scores). Study procedures occurred over four consecutive days, with working memory testing on Days 1 and 4, and DAR-0100A/placebo administration on Days 2–4. Treatment with DAR-0100A was associated with significantly improved PASAT performance relative to placebo, with a very large effect size (Cohen''s d=1.14). Performance on the N-back ratio was also significantly improved; however, this effect rested on both a non-significant enhancement and diminution of 2-back and 0-back performance, respectively; therefore interpretation of this finding is more complicated. DAR-0100A was generally well tolerated, with no serious medical or psychiatric adverse events; common side effects were mild to moderate and transient, consisting mainly of sedation, lightheadedness, tachycardia, and hypotension; however, we were able to minimize these effects, without altering the dose, with supportive measures, eg, co-administered normal saline. Although preliminary, these findings lend further clinical support to the potential of D₁ receptor agonists to treat schizophrenia-spectrum working memory impairments. These data suggest a need for further studies with larger group sizes, serum DAR-0100A levels, and a more comprehensive neuropsychological battery.     

Prostate Cancer Ambassadors: Enhancing a Theory-Informed Training Program for Informed Decision-Making

Despite the high burden of prostate cancer in African American communities, there is a paucity of knowledge about prostate health. This paper describes the enhancement of a curriculum for training lay health advisors, called prostate cancer ambassadors, on informed decision-making for prostate cancer screening. Adult learning theory informed the structuring of the training sessions to be interactive, self-directed, and engaging. Trainings were developed in a manner that made the material relevant to the learners and encouraged co-learning. The research team developed strategies, such as using discussions and interactive activities, to help community members weigh the pros and cons of prostate-specific antigen (PSA) screening and to make an informed decision about screening. Furthermore, activities were developed to bolster four social cognitive theory constructs: observational learning, self-efficacy for presenting information to the community and for making an informed decision themselves, collective efficacy for presenting information to the community, and outcome expectations from those presentations. Games, discussions, and debates were included to make learning fun and encourage discovery. Practice sessions and team-building activities were designed to build self-efficacy for sharing information about informed decision-making. Topics added to the original curriculum included updates on prostate cancer screening, informed decision-making for screening, skills for being a lay health advisor, and ethics. This dynamic model and approach to lay health advisor (ambassador) training is flexible: while it was tailored for use with prostate cancer education, it can be adjusted for use with other types of cancer and even other diseases.     

Prevention of atrial fibrillation onset by beta-blocker treatment in heart failure: a meta-analysis.

AIMS: Atrial fibrillation (AF) is an important morbidity-mortality risk factor, especially in patients with heart failure (HF). Beta-blockers reduce morbidity and mortality in HF. The study was designed to estimate the preventive efficacy of beta-blocker treatment on AF occurrence in patients with HF. METHODS AND RESULTS: A systematic review of the literature was performed to identify all clinical trials evaluating beta-blockers' efficacy in HF. Eligible studies had to be randomized, placebo-controlled and providing information on the incidence of AF during follow-up among those with sinus rhythm at baseline. A total of seven studies which included 11 952 patients receiving a background treatment with angiotensin-converting enzyme-inhibitors could be found. Overall, beta-blockers significantly reduced incidence of onset of AF from 39 to 28 per 1000 patient-years: relative risk reduction=27% (95% confidence interval 14-38, P<0.001); heterogeneity test: P=0.096. A same trend of efficacy was observed in all trials except the SENIORS study. In this trial which included aged patients (>70 years) with systolic or diastolic HF, a higher prevalence of AF at baseline (35%) was observed compared with the mean baseline prevalence (13%). CONCLUSION: Beta-blockers appear to effectively prevent occurrence of AF in patients with systolic HF.     

A novel mutation in the DLG3 gene encoding the synapse-associated protein 102 (SAP102) causes non-syndromic mental retardation

We have identified a novel splice site mutation (IVS6-1G?>?A) in the disc-large homolog 3 (DLG3) gene, encoding the synapse-associated protein 102 (SAP102) in one out of 300 families with moderate to severe non-syndromic mental retardation. SAP102 is a member of the neuronal membrane-associated guanylate kinase protein subfamily comprising SAP97, postsynaptic density (PSD)95, and PSD93, which interacts with methyl-d-aspartate receptor and associated protein complexes at the postsynaptic density of excitatory synapses. DLG3 is the first mental retardation gene directly linked to glutamate receptor signalling and trafficking, increasingly recognised as a central mechanism in the regulation of synaptic formation and plasticity in brain and cognitive development.     

Fibrolipoma of the median nerve

Neural fibrolipoma or fibrolipomatous hamartoma is an uncommon benign tumor that usually arises in the median nerve. Fibrofatty tissue proliferates around the nerve and infiltrates the epineurium and perineurium. We report a case of fibrolipomatous hamartoma of the left median nerve in an 18-year-old woman. Our objective was to describe the pathognomonic magnetic resonance imaging features, whose presence obviates the need for a diagnostic biopsy.     

Vulnerabilities and Caregiving in an Ethnically Diverse HIV-Infected Population

The current study aimed to identify the primary informal caregivers of a group of urban HIV+ adults (n = 250) and to determine relationships between demographic, medical, and substance use characteristics and caregivers types. Reported caregiver types included 36.8% familial, 22.4% significant other, and 22.8% institutional or other caregiver relationships. The remaining 18% of the sample reported having no individual that rendered informal care. Factors associated with the absence of an informal caregiver included African American race and low education. Hispanic participants reported the highest frequency of family caregivers while participants with a history of substance disorder were less likely to identify a significant other as a caregiver. This study demonstrates the evolving nature of informal caregiving in HIV, race- and education-related disparities in the absence of primary caregivers, and the importance of sociocultural and demographic factors in the study of HIV caregiving. Research supported by R24MH59724 from the National Institutes of Health.     

A peptide selected by biopanning identifies the integrin alphavbeta6 as a prognostic biomarker for nonsmall cell lung cancer

The development of new modes of diagnosis and targeted therapy for lung cancer is dependent on the identification of unique cell surface features on cancer cells and isolation of reagents that bind with high affinity and specificity to these biomarkers. We recently isolated a 20-mer peptide which binds to the lung adenocarcinoma cell line, H2009, from a phage-displayed peptide library. We show here that the cellular receptor for this peptide, TP H2009.1, is the uniquely expressed integrin, alphavbeta6, and the peptide binding to lung cancer cell lines correlates to integrin expression. The peptide is able to mediate cell-specific uptake of a fluorescent nanoparticle via this receptor. Expression of alphavbeta6 was assessed on 311 human lung cancer samples. The expression of this integrin is widespread in early-stage nonsmall cell lung carcinoma (NSCLC). Log-rank test and Cox regression analyses show that expression of this integrin is significantly associated with poor patient outcome. Preferential expression is observed in the tumors compared with the surrounding normal lung tissue. Our data indicate that alphavbeta6 is a prognostic biomarker for NSCLC and may serve as a receptor for targeted therapies. Thus, cell-specific peptides isolated from phage biopanning can be used for the discovery of cell surface biomarkers, emphasizing the utility of peptide libraries to probe the surface of a cell.