Recalibration of the Limiting Antigen Avidity EIA to Determine Mean Duration of Recent Infection in Divergent HIV-1 Subtypes

BackgroundMean duration of recent infection (MDRI) and misclassification of long-term HIV-1 infections, as proportion false recent (PFR), are critical parameters for laboratory-based assays for estimating HIV-1 incidence. Recent review of the data by us and others indicated that MDRI of LAg-Avidity EIA estimated previously required recalibration. We present here results of recalibration efforts using >250 seroconversion panels and multiple statistical methods to ensure accuracy and consensus.MethodsA total of 2737 longitudinal specimens collected from 259 seroconverting individuals infected with diverse HIV-1 subtypes were tested with the LAg-Avidity EIA as previously described. Data were analyzed for determination of MDRI at ODn cutoffs of 1.0 to 2.0 using 7 statistical approaches and sub-analyzed by HIV-1 subtypes. In addition, 3740 specimens from individuals with infection >1 year, including 488 from patients with AIDS, were tested for PFR at varying cutoffs.ResultsUsing different statistical methods, MDRI values ranged from 88–94 days at cutoff ODn = 1.0 to 177–183 days at ODn = 2.0. The MDRI values were similar by different methods suggesting coherence of different approaches. Testing for misclassification among long-term infections indicated that overall PFRs were 0.6% to 2.5% at increasing cutoffs of 1.0 to 2.0, respectively. Balancing the need for a longer MDRI and smaller PFR (<2.0%) suggests that a cutoff ODn = 1.5, corresponding to an MDRI of 130 days should be used for cross-sectional application. The MDRI varied among subtypes from 109 days (subtype A&D) to 152 days (subtype C).ConclusionsBased on the new data and revised analysis, we recommend an ODn cutoff = 1.5 to classify recent and long-term infections, corresponding to an MDRI of 130 days (118–142). Determination of revised parameters for estimation of HIV-1 incidence should facilitate application of the LAg-Avidity EIA for worldwide use.     

The Bidirectional Relationship between Quality of Life and Eating Disorder Symptoms: A 9-Year Community-Based Study of Australian Women

Objective

Studies that have investigated quality of life (QoL) in eating disorders (EDs) have been focussed on the impact of the ED on QoL and little is known regarding the possible reciprocal impact of QoL on EDs. The aim of this study was to provide a first-time investigation of possible bidirectional relationships between EDs and both health-related QoL (HRQoL) and psychological distress (PD).

Method

Structural equation modeling was applied to longitudinal data collected from a community sample of Australian women (N = 828) surveyed at baseline, five annual follow-ups, and again after nine years. Participants reported height and weight (from which body mass index, BMI, was calculated) and completed measures of ED symptoms (Eating Disorder Examination Questionnaire), HRQoL (12-item Medical Outcomes Study Short Form), and PD (Kessler Psychological Distress Scale).

Results

Overall, evidence was found for a bidirectional relationship, whereby ED symptoms predicted reduced HRQoL and greater PD over time, while lower levels of HRQoL and greater PD in turn predicted increased levels of ED symptoms. These relationships were stable, observable within 12 months, and remained observable over a time period of at least four years. However, also observed were some inconsistent findings where ED symptoms predicted a short term (one year) improvement in mental HRQoL. This short term boost was not sustained at longer follow-ups.

Conclusions

Not only do ED symptoms impact on HRQoL and PD, but perceived poor HRQoL and PD also contribute to ED symptom development or exacerbation. This supports a movement away from symptom-centric approaches whereby HRQoL is conceptualized as a passive outcome expected to be rectified by addressing ED symptoms. Improvement in QoL and PD might rather be viewed as targets to be pursued in their own right under broader approaches in the treatment of EDs.     

Comparison of two kinds of Biolog microplates (GN and ECO) in their ability to distinguish among aquatic microbial communities.

We compared the abilities of Biolog's GN and ECO plates to distinguish among aerobic and heterotrophic bacterial communities in samples from six aquatic environments. The Biolog system is based on interpreting patterns of sole-carbon substrate utilization indicated by color development in a 96-well microtiter plate. Whether of fresh or saltwater origin, bacterial communities utilized > 95% of substrates in both types of plates. Samples from any one environment exhibited similar time courses of average well color development (AWCD) in both GN and ECO plates. Principal component analysis was performed on data sets resulting from combinations of algorithms (AWCD and curve-integration methods) and levels of color development (end-point and set-point approaches). In all cases, the two types of plates demonstrated an equal capacity to discriminate among the heterotrophic expressions of the six microbial communities. Substantial deviation from an anticipated 1:1 correspondence occurred when color development of 25 substrates common to both types of plates was compared. The discrepancies likely are related to the different formulations of low-nutrient media in GN and ECO plates.     

dgq: a drosophila gene encoding a visual system-specific G alpha molecule

We describe the isolation and preliminary characterization of a new G alpha gene (dgq) in Drosophila. The dgq gene is differentially spliced, yielding two putative proteins, both of which contain guanine nucleotide binding and hydrolysis domains and share 50% identity with transducins and other G proteins. These proteins represent a new class of G alpha subunits because they lack both high amino acid identity with other G alpha proteins and the pertussis toxin ADP ribosylation site. The dgq mRNA is detected by RNA-RNA Northern hybridization in wild-type heads but not in wild-type bodies or in the mutant eyes absent heads. Tissue in situ hybridization detects dgq expression only in the retina and ocellus of the adult head, making it a prime candidate for encoding the Drosophila transducin analog, the G protein required for phototransduction.     

Facial Identity Recognition in the Broader Autism Phenotype

Background

The ‘broader autism phenotype’ (BAP) refers to the mild expression of autistic-like traits in the relatives of individuals with autism spectrum disorder (ASD). Establishing the presence of ASD traits provides insight into which traits are heritable in ASD. Here, the ability to recognise facial identity was tested in 33 parents of ASD children.

Methodology and Results

In experiment 1, parents of ASD children completed the Cambridge Face Memory Test (CFMT), and a questionnaire assessing the presence of autistic personality traits. The parents, particularly the fathers, were impaired on the CFMT, but there were no associations between face recognition ability and autistic personality traits. In experiment 2, parents and probands completed equivalent versions of a simple test of face matching. On this task, the parents were not impaired relative to typically developing controls, however the proband group was impaired. Crucially, the mothers'' face matching scores correlated with the probands'', even when performance on an equivalent test of matching non-face stimuli was controlled for.

Conclusions and Significance

Components of face recognition ability are impaired in some relatives of ASD individuals. Results suggest that face recognition skills are heritable in ASD, and genetic and environmental factors accounting for the pattern of heritability are discussed. In general, results demonstrate the importance of assessing the skill level in the proband when investigating particular characteristics of the BAP.