Hormone replacement therapy and other potential treatments for dementias

The past decade has seen a substantial increase in the number of individuals affected by dementia. Dementia places a tremendous personal and economic burden on millions of patients and caregivers annually. Consequently, many scientists have been searching for a treatment for dementia to avoid the imminent public health crisis that will occur if this trend continues. Primary and secondary prevention studies, as well as animal research, demonstrate the potential for hormone replacement therapy (HRT) as an efficacious treatment for dementia. Recently, the Women's Health Initiative-Memory Study began the first randomized, longterm clinical trial to test the hypothesized role of HRT at the onset and in the progression of dementia in women. Researchers also are investigating the potential of other treatments for dementias, such as nonsteroidal anti-inflammatory drugs and free radical scavengers.     

Introduction.

This article introduces this special issue of Health Psychology. Its purpose is to summarize recent findings on the influence of race on autonomic nervous system reactivity. Many but not all of the studies in this special issue were funded by a National Heart, Lung, and Blood Institute initiative. The studies reported herein, as well as those published recently in other journals (for a review, see Anderson 1989), represent perhaps the first generation of studies that have explored the reactivity model in Blacks. As such, they provide an empirical foundation on which future studies may build. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

TPEN, a Zn2+/Fe2+ chelator with low affinity for Ca2+, inhibits lamin assembly, destabilizes nuclear architecture and may independently protect nuclei from apoptosis in vitro

We used Xenopus egg extracts to examine the effects of TPEN, a chelator with strong affinities for Zn2+, Fe2+, and Mn2+, on nuclear assembly in vitro. At concentrations above 1 mM, TPEN blocked the assembly of the nuclear lamina and produced nuclei that were profoundly sensitive to stress-induced balloon-like 'shedding' of nuclear membranes away from chromatin-associated membranes. TPEN-arrested nuclei were also defective for DNA replication, which could be explained as secondary to the lack of a lamina. Imaging of TPEN-arrested nuclei by field emission in-lens scanning electron microscopy (FEISEM) revealed clustered, structurally-perturbed nuclear pore complexes. TPEN-arrested nuclei were defective in the accumulation of fluorescent karyophilic proteins. All detectable effects caused by TPEN were downstream of the effects of BAPTA, a Ca2+/Zn2+ chelator that blocks pore complex assembly at two distinct early stages. Surprisingly, TPEN-arrested nuclei, but not control nuclei, remained active for replication in apoptotic extracts, as assayed by [32P]-dCTP incorporation into high molecular weight DNA, suggesting that TPEN blocks a metal-binding protein(s) required for nuclear destruction during programmed cell death.     

Catastrophe models for cognitive workload and fatigue

We reconceptualised several problems concerning the measurement of cognitive workload – fixed versus variable limits on channel capacity, work volume versus time pressure, adaptive strategies, resources demanded by tasks when performed simultaneously, and unclear distinctions between workload and fatigue effects – as two cusp catastrophe models: buckling stress resulting from acute workload, and fatigue resulting from extended engagement. Experimental participants completed a task that was intensive on non-verbal episodic memory and had an automatically speeded component. For buckling stress, the epoch of maximum (speeded) performance was the asymmetry parameter; however, anxiety did not contribute to bifurcation as expected. For fatigue, the bifurcation factor was the total work accomplished, and arithmetic, a compensatory ability, was the asymmetry parameter; R ² for the cusp models outperformed the linear comparison models in both cases. A research programme is outlined that revolves around the two models with different types of task and resource configurations.     

Women's Health Initiative: Why now? What is it? What's new?

Studies collectively named the Women's Health Initiative (WHI) are currently enrolling 164,500 postmenopausal women in several overlapping clinical trials and an observational study. The overall goals of WHI are to understand the determinants of postmenopausal women's health and to evaluate the efficacy of practical interventions in preventing the major causes of morbidity and mortality in older women. This article reviews the research leading to the WHI studies; describes the study designs and protocols, with an emphasis on what's new about WHI from a psychological perspective; and outlines the major psychosocial hypotheses under investigation and the major challenges WHI presents to psychological science. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of high temperature polyaspartimide-urea based shape memory polymers

Thermally activated shape memory polymers (SMPs) have attracted great interest in recent years for application in adaptive shape-changing (morphing) aero structures. However, these components require materials with transition temperatures well above the glass transition temperatures of most widely available SMPs while also maintaining processability and property tailorability. In the present study, a series of novel polyaspartimide-urea based polymers are synthesized and characterized. The glass transition temperature and shape memory properties are varied using a diisocyanate resin creating a urea crosslinking moiety between the polyaspartimide chains. Overall, a family of high temperature SMPs was synthesized and characterized showing high thermal stability (>300 °C), toughness, strong shape memory effects, and tailorable properties.     

Further characterization of factor VIII-deficient mice created by gene targeting: RNA and protein studies

Cryptococcal meningitis occurs in 6 to 8% of human immunodeficiency virus-infected individuals. Despite the availability of powerful antifungal agents that are active against Cryptococcus neoformans, these drugs generally fail to cure cryptococcal infections in immunocompromised hosts. Alternative approaches to prevention and therapy of cryptococcosis are urgently needed. Complement promotes phagocytosis of C. neoformans, but human antibodies to cryptococcal capsular polysaccharide have not been shown to function as complement-independent opsonins. The goal of our studies was to characterize the in vitro biological function of human antibodies to glucuronoxylomannan (GXM) from individuals immunized with a GXM-tetanus toxoid (GXM-TT) vaccine. We studied sera from nine vaccinees that manifested good serologic responses to GXM-TT. The results indicate that GXM-TT-elicited antibodies promote phagocytosis of C. neoformans by both murine J774 cells and human peripheral blood mononuclear cells (PBMCs). The two sera with the highest titers of anti-GXM immunoglobulin G2 antibodies were the most opsonic. When PBMC Fc gamma RIIa receptors were blocked, a 75% decrease in phagocytosis occurred following incubation of the PBMCs with C. neoformans opsonized with these sera. Our data indicate that, in the absence of complement, human anti-GXM-TT antibodies are opsonic and that antibodies of the immunoglobulin G2 isotype are effective opsonins.