Hormonal Influences on Cognition and Risk for Alzheimer’s Disease

Research increasingly suggests that changes in estrogen levels during aging may increase the risk of Alzheimer’s disease, the most common type of dementia. This update reviews the newest information about estrogen and cognitive aging, including information regarding the role of bioavailable estrogen in older women and men, use of selective estrogen receptor modulators to improve cognition, and studies of genetic risk factors to elucidate the effects of endogenous estrogen on aging and cognition. Future trials are needed to determine whether alternate timing, dosage, formulation, or method of administration of hormone replacement can reduce the risk of dementia.     

Early Ethnic Inequality: The Influence of Social Background and Parental Involvement on Preschool Children’s Cognitive Ability in Germany

International research on educational inequality consistently reports the existence of ethnic differences in school achievement. The paper explores as a prior stage early cognitive differences between 3- to 4-year-old natives and immigrants in Germany and tests whether ethnic differences in cognitive outcomes can be essentially explained by the parents’ social background and the home environment of the children. It is assumed that children’s later educational success depends on their abilities at preschool age. The acquisition of these abilities is determined particularly by the family, the children’s home environment and through institutional care. The data of a German project “Preschool education and educational careers among migrant children” reveal the existence of inequality in cognitive scores between natives and Turkish children. These differences cannot be explained by controlling for the social background of the families, nor by the home environment. A main result of the analyses shows that both factors are important.     

Perception,attitudes and knowledge regarding the 2009 swine‐origin influenza A (H1N1) virus pandemic among health‐care workers in Australia

Aim: To determine the perceptions, attitudes and knowledge of Australian health‐care workers (HCWs) regarding the novel, swine‐origin influenza A (H1N1) virus (S‐OIV) outbreak that reached the country in early May 2009. Methods: Self‐administered, anonymous Web‐based survey conducted during the early stages of the S‐OIV pandemic. Participants comprised hospital‐ and community‐based medical and nursing staff, medical students, allied health professionals, laboratory staff and administrative personnel. Results: Of the 947 participants surveyed, 59.4% were not convinced that Australia was sufficiently prepared for an influenza pandemic. Only 17.6% of the participants stated they were prepared to work unconditionally during a pandemic; 36.5% stated they would work if they had access to antiviral treatment; 27.9% would if provided with antiviral prophylaxis; and 7.5% would refuse to work. In addition, 37.5% of the participants responded they would refuse or avoid being involved in screening suspected cases. A total of 47.7% admitted to possessing a personal supply of antivirals or having considered this option. Only 48.0% provided a realistic estimate of the mortality associated with an influenza pandemic at a population level. HCWs overestimating the mortality risk and HCWs believing the efficacy of antiviral prophylaxis to be low were significantly less likely to be prepared to work (P= 0.04 and P= 0.0004, respectively). Conclusions: To ensure adequate staffing during an influenza pandemic, preparedness plans should anticipate significant levels of absenteeism by choice. Interventions aimed at increasing staff retention during a pandemic require further evaluation.     

Mild parkinsonian signs are associated with increased risk of dementia in a prospective,population‐based study of elders

There is some evidence that mild parkinsonian signs (MPSs) are associated with increased risk of dementia, suggesting that MPS could be an early biomarker for dementia. Our aims, in a new cohort, were to determine whether (1) baseline MPS are a predictor of incident dementia and (2) there is an interaction between MPS and other baseline risk factors for dementia (i.e., the presence of both together greatly elevates the risk of dementia) was the objective. In a prospective, longitudinal study of community‐dwelling elders in northern Manhattan, NY, Parkinsonian signs were rated with an abbreviated Unified Parkinson's Disease Rating Scale. Risk of incident dementia was assessed using Cox proportional hazards models. There were 1,851 participants (mean follow‐up = 3.7 years). Participants with baseline MPS were twice as likely to develop dementia as participants without MPS: 16.3% versus 7.7%, unadjusted hazards ratio (HR) = 2.24 (P< 0.001), adjusted HR = 1.98 (P < 0.001). MPS were divided into three subtypes: adjusted HR_{axial dysfunction} = 2.45 (P < 0.001), adjusted HR_tremor = 2.38 (P = 0.006), and adjusted HR_rigidity = 1.16 (P = 0.58). When MPS were treated as a continuous variable, the adjusted HR = 1.15 (P = 0.001). There were no interactions between MPS and other baseline risk factors for dementia, including gender, education, race, family history of dementia, stroke, and apolipoprotein E‐e4. Baseline MPS seems to be a predictor of incident dementia. These motor signs might, therefore, serve as a useful biomarker for emerging dementia. © 2010 Movement Disorder Society     

Convergent ethical issues in HIV/AIDS,tuberculosis and malaria vaccine trials in Africa: Report from the WHO/UNAIDS African AIDS Vaccine Programme's Ethics,Law and Human Rights Collaborating Centre consultation, 10-11 February 2009, Durban,South Africa

Background  

Africa continues to bear a disproportionate share of the global HIV/AIDS, tuberculosis (TB) and malaria burden. The development and distribution of safe, effective and affordable vaccines is critical to reduce these epidemics. However, conducting HIV/AIDS, TB, and/or malaria vaccine trials simultaneously in developing countries, or in populations affected by all three diseases, is likely to result in numerous ethical challenges.     

Biogeography of the Sulfolobus islandicus pan-genome

Variation in gene content has been hypothesized to be the primary mode of adaptive evolution in microorganisms; however, very little is known about the spatial and temporal distribution of variable genes. Through population-scale comparative genomics of 7 Sulfolobus islandicus genomes from 3 locations, we demonstrate the biogeographical structure of the pan-genome of this species, with no evidence of gene flow between geographically isolated populations. The evolutionary independence of each population allowed us to assess genome dynamics over very recent evolutionary time, beginning ≈910,000 years ago. On this time scale, genome variation largely consists of recent strain-specific integration of mobile elements. Localized sectors of parallel gene loss are identified; however, the balance between the gain and loss of genetic material suggests that S. islandicus genomes acquire material slowly over time, primarily from closely related Sulfolobus species. Examination of the genome dynamics through population genomics in S. islandicus exposes the process of allopatric speciation in thermophilic Archaea and brings us closer to a generalized framework for understanding microbial genome evolution in a spatial context.