Serum beta-amyloid correlates with neuropsychological impairment

AIMS: Evidence suggests a relationship between peripheral Abeta and AD. We hypothesized that higher levels of serum Abeta(1-42) would be associated with memory impairment, thought to occur early in the disease, and rises in serum Abeta(1-40), which occur later, would be associated with impairment in non-memory measures. METHODS: Using a cross-sectional design, we examined the relationship of serum Abeta(1-40), Abeta(1-42), and the ratio of Abeta(1-42/1-40) to neuropsychological measures in 40 cognitively normal controls, 13 MCI subjects, and 25 AD patients. RESULTS: Serum Abeta(1-42) and the ratio of Abeta(1-42/1-40) were significantly higher in the MCI group compared to the controls. A significant relationship in the hypothesized direction (poorer scores associated with higher Abeta(1-40) serum levels) was found between Abeta(1-40) and measures of executive functions across the entire cohort of individuals tested and with measures of language and processing speed in the AD group. Regression analysis found that neuropsychological measures accounted for 26% of the variance in serum Abeta(1-40,) in the MCI/AD but not the controls. Furthermore that language and executive measures were significant predictors. CONCLUSIONS: Results provide preliminary data to partially support our hypotheses and suggest that changes in serum Abeta levels may be attributed to pathological changes within the brain.     

What Concerns do Young Adults in Ireland Have about Attending Health Services for STD Testing?

Thirty Irish young adults (between eighteen and twenty-nine years of age) were interviewed about their experiences of accessing and attending healthcare settings for STD (sexually transmitted disease) testing. Four principle themes emerged: the risk of stigma as a result of seeking STD testing; the need to engage in impression management activities while accessing information about STD testing; the importance of using healthcare settings that supported rather than undermined impression management attempts; and identity risks experienced while waiting in clinic reception areas. Findings are discussed in relation to previous research on this topic.     

Serum β-Amyloid Correlates with Neuropsychological Impairment

ABSTRACT

Aims: Evidence suggests a relationship between peripheral Aβ and AD. We hypothesized that higher levels of serum Aβ_1–42 would be associated with memory impairment, thought to occur early in the disease, and rises in serum Aβ_1–40, which occur later, would be associated with impairment in non-memory measures. Methods: Using a cross-sectional design, we examined the relationship of serum Aβ_1–40, Aβ_1–42, and the ratio of Aβ_{1–42/1–40} to neuropsychological measures in 40 cognitively normal controls, 13 MCI subjects, and 25 AD patients. Results: Serum Aβ_1–42 and the ratio of Aβ_{1–42/1–40} were significantly higher in the MCI group compared to the controls. A significant relationship in the hypothesized direction (poorer scores associated with higher Aβ_1–40 serum levels) was found between Aβ_1–40 and measures of executive functions across the entire cohort of individuals tested and with measures of language and processing speed in the AD group. Regression analysis found that neuropsychological measures accounted for 26% of the variance in serum Aβ_1–40, in the MCI/AD but not the controls. Furthermore that language and executive measures were significant predictors. Conclusions: Results provide preliminary data to partially support our hypotheses and suggest that changes in serum Aβ levels may be attributed to pathological changes within the brain.     

How research ethics boards are undermining survey research on Canadian university students

In Canada, all research conducted by individuals associated with universities must be subjected to review by research ethics boards (REB). Unfortunately, decisions reached by REBs may seriously compromise the integrity of university-based research. In this paper attention will focus on how requirements of REBs and a legal department in four Canadian universities affected response rates to a survey of domestic and international students. It will be shown that in universities in which students were sent a legalistic cover letter to a mail survey, or were required to sign a consent form, lower response rates were achieved than in universities in which students were sent a relatively friendly letter. In turn, lower response rates resulted in: sample characteristics that deviated from population characteristics; a reduction in the possibility of testing research hypotheses; and increased survey costs. As a consequence, it is argued that the unreasonable demands of REBs are seriously compromising the quality of research that can be carried out on Canadian university students.     

Self‐reference and group membership: evidence for a group‐reference effect

Two experiments were designed to explore whether encoding information in reference to a group would facilitate the later recall of that information to the same extent as encoding with reference to the self. In both experiments, participants encoded adjectives with reference to the self, semantic properties, or a group and were subsequently given a surprise‐free recall test. In Experiment 1 (N = 37), the participants' university served as the reference group. In Experiment 2 (N=41), the participants' family served as the reference group. In both experiments, self‐reference resulted in better recall than semantic processing, replicating the typical self‐reference effect (SRE). More importantly, strong evidence for a group‐reference effect (GRE) was found in that group‐reference resulted in better recall than semantic processing and in fact facilitated recall to the same extent as self‐referencing. The existing explanations (schemas, organization, elaboration, mental cueing, and evaluation) for the SRE were compared with regard to their viability in accounting for the GRE patterns. We discuss additional features that may be important in the explanation of the SRE and suggest future directions for research on group‐referencing. Copyright © 2002 John Wiley & Sons, Ltd.     

Food reinforcement and eating: a multilevel analysis

Eating represents a choice among many alternative behaviors. The purpose of this review is to provide an overview of how food reinforcement and behavioral choice theory are related to eating and to show how this theoretical approach may help organize research on eating from molecular genetics through treatment and prevention of obesity. Special emphasis is placed on how food reinforcement and behavioral choice theory are relevant to understanding excess energy intake and obesity and how they provide a framework for examining factors that may influence eating and are outside of those that may regulate energy homeostasis. Methods to measure food reinforcement are reviewed, along with factors that influence the reinforcing value of eating. Contributions of neuroscience and genetics to the study of food reinforcement are illustrated by using the example of dopamine. Implications of food reinforcement for obesity and positive energy balance are explored, with suggestions for novel approaches to obesity treatment based on the synthesis of behavioral and pharmacological approaches to food reinforcement.